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Sample records for resampling-based significance testing

  1. Introduction to Permutation and Resampling-Based Hypothesis Tests

    ERIC Educational Resources Information Center

    LaFleur, Bonnie J.; Greevy, Robert A.

    2009-01-01

    A resampling-based method of inference--permutation tests--is often used when distributional assumptions are questionable or unmet. Not only are these methods useful for obvious departures from parametric assumptions (e.g., normality) and small sample sizes, but they are also more robust than their parametric counterparts in the presences of…

  2. Statistical properties of an early stopping rule for resampling-based multiple testing.

    PubMed

    Jiang, Hui; Salzman, Julia

    2012-12-01

    Resampling-based methods for multiple hypothesis testing often lead to long run times when the number of tests is large. This paper presents a simple rule that substantially reduces computation by allowing resampling to terminate early on a subset of tests. We prove that the method has a low probability of obtaining a set of rejected hypotheses different from those rejected without early stopping, and obtain error bounds for multiple hypothesis testing. Simulation shows that our approach saves more computation than other available procedures.

  3. Power and stability properties of resampling-based multiple testing procedures with applications to gene oncology studies.

    PubMed

    Li, Dongmei; Dye, Timothy D

    2013-01-01

    Resampling-based multiple testing procedures are widely used in genomic studies to identify differentially expressed genes and to conduct genome-wide association studies. However, the power and stability properties of these popular resampling-based multiple testing procedures have not been extensively evaluated. Our study focuses on investigating the power and stability of seven resampling-based multiple testing procedures frequently used in high-throughput data analysis for small sample size data through simulations and gene oncology examples. The bootstrap single-step minP procedure and the bootstrap step-down minP procedure perform the best among all tested procedures, when sample size is as small as 3 in each group and either familywise error rate or false discovery rate control is desired. When sample size increases to 12 and false discovery rate control is desired, the permutation maxT procedure and the permutation minP procedure perform best. Our results provide guidance for high-throughput data analysis when sample size is small.

  4. Rapid and robust resampling-based multiple-testing correction with application in a genome-wide expression quantitative trait loci study.

    PubMed

    Zhang, Xiang; Huang, Shunping; Sun, Wei; Wang, Wei

    2012-04-01

    Genome-wide expression quantitative trait loci (eQTL) studies have emerged as a powerful tool to understand the genetic basis of gene expression and complex traits. In a typical eQTL study, the huge number of genetic markers and expression traits and their complicated correlations present a challenging multiple-testing correction problem. The resampling-based test using permutation or bootstrap procedures is a standard approach to address the multiple-testing problem in eQTL studies. A brute force application of the resampling-based test to large-scale eQTL data sets is often computationally infeasible. Several computationally efficient methods have been proposed to calculate approximate resampling-based P-values. However, these methods rely on certain assumptions about the correlation structure of the genetic markers, which may not be valid for certain studies. We propose a novel algorithm, rapid and exact multiple testing correction by resampling (REM), to address this challenge. REM calculates the exact resampling-based P-values in a computationally efficient manner. The computational advantage of REM lies in its strategy of pruning the search space by skipping genetic markers whose upper bounds on test statistics are small. REM does not rely on any assumption about the correlation structure of the genetic markers. It can be applied to a variety of resampling-based multiple-testing correction methods including permutation and bootstrap methods. We evaluate REM on three eQTL data sets (yeast, inbred mouse, and human rare variants) and show that it achieves accurate resampling-based P-value estimation with much less computational cost than existing methods. The software is available at http://csbio.unc.edu/eQTL.

  5. Assessing differential expression in two-color microarrays: a resampling-based empirical Bayes approach.

    PubMed

    Li, Dongmei; Le Pape, Marc A; Parikh, Nisha I; Chen, Will X; Dye, Timothy D

    2013-01-01

    Microarrays are widely used for examining differential gene expression, identifying single nucleotide polymorphisms, and detecting methylation loci. Multiple testing methods in microarray data analysis aim at controlling both Type I and Type II error rates; however, real microarray data do not always fit their distribution assumptions. Smyth's ubiquitous parametric method, for example, inadequately accommodates violations of normality assumptions, resulting in inflated Type I error rates. The Significance Analysis of Microarrays, another widely used microarray data analysis method, is based on a permutation test and is robust to non-normally distributed data; however, the Significance Analysis of Microarrays method fold change criteria are problematic, and can critically alter the conclusion of a study, as a result of compositional changes of the control data set in the analysis. We propose a novel approach, combining resampling with empirical Bayes methods: the Resampling-based empirical Bayes Methods. This approach not only reduces false discovery rates for non-normally distributed microarray data, but it is also impervious to fold change threshold since no control data set selection is needed. Through simulation studies, sensitivities, specificities, total rejections, and false discovery rates are compared across the Smyth's parametric method, the Significance Analysis of Microarrays, and the Resampling-based empirical Bayes Methods. Differences in false discovery rates controls between each approach are illustrated through a preterm delivery methylation study. The results show that the Resampling-based empirical Bayes Methods offer significantly higher specificity and lower false discovery rates compared to Smyth's parametric method when data are not normally distributed. The Resampling-based empirical Bayes Methods also offers higher statistical power than the Significance Analysis of Microarrays method when the proportion of significantly differentially

  6. Assessment of Person Fit Using Resampling-Based Approaches

    ERIC Educational Resources Information Center

    Sinharay, Sandip

    2016-01-01

    De la Torre and Deng suggested a resampling-based approach for person-fit assessment (PFA). The approach involves the use of the [math equation unavailable] statistic, a corrected expected a posteriori estimate of the examinee ability, and the Monte Carlo (MC) resampling method. The Type I error rate of the approach was closer to the nominal level…

  7. A Resampling Based Approach to Optimal Experimental Design for Computer Analysis of a Complex System

    SciTech Connect

    Rutherford, Brian

    1999-08-04

    The investigation of a complex system is often performed using computer generated response data supplemented by system and component test results where possible. Analysts rely on an efficient use of limited experimental resources to test the physical system, evaluate the models and to assure (to the extent possible) that the models accurately simulate the system order investigation. The general problem considered here is one where only a restricted number of system simulations (or physical tests) can be performed to provide additional data necessary to accomplish the project objectives. The levels of variables used for defining input scenarios, for setting system parameters and for initializing other experimental options must be selected in an efficient way. The use of computer algorithms to support experimental design in complex problems has been a topic of recent research in the areas of statistics and engineering. This paper describes a resampling based approach to form dating this design. An example is provided illustrating in two dimensions how the algorithm works and indicating its potential on larger problems. The results show that the proposed approach has characteristics desirable of an algorithmic approach on the simple examples. Further experimentation is needed to evaluate its performance on larger problems.

  8. Statistical Significance Testing.

    ERIC Educational Resources Information Center

    McLean, James E., Ed.; Kaufman, Alan S., Ed.

    1998-01-01

    The controversy about the use or misuse of statistical significance testing has become the major methodological issue in educational research. This special issue contains three articles that explore the controversy, three commentaries on these articles, an overall response, and three rejoinders by the first three authors. They are: (1)…

  9. Reconstruction of micron resolution mouse brain surface from large-scale imaging dataset using resampling-based variational model

    PubMed Central

    Li, Jing; Quan, Tingwei; Li, Shiwei; Zhou, Hang; Luo, Qingming; Gong, Hui; Zeng, Shaoqun

    2015-01-01

    Brain surface profile is essential for brain studies, including registration, segmentation of brain structure and drawing neuronal circuits. Recent advances in high-throughput imaging techniques enable imaging whole mouse brain at micron spatial resolution and provide a basis for more fine quantitative studies in neuroscience. However, reconstructing micron resolution brain surface from newly produced neuronal dataset still faces challenges. Most current methods apply global analysis, which are neither applicable to a large imaging dataset nor to a brain surface with an inhomogeneous signal intensity. Here, we proposed a resampling-based variational model for this purpose. In this model, the movement directions of the initial boundary elements are fixed, the final positions of the initial boundary elements that form the brain surface are determined by the local signal intensity. These features assure an effective reconstruction of the brain surface from a new brain dataset. Compared with conventional typical methods, such as level set based method and active contour method, our method significantly increases the recall and precision rates above 97% and is approximately hundreds-fold faster. We demonstrated a fast reconstruction at micron level of the whole brain surface from a large dataset of hundreds of GB in size within 6 hours. PMID:26245266

  10. Asymptotic Distributions for Tests of Combined Significance.

    ERIC Educational Resources Information Center

    Becker, Betsy Jane

    This paper discusses distribution theory and power computations for four common "tests of combined significance." These tests are calculated using one-sided sample probabilities or p values from independent studies (or hypothesis tests), and provide an overall significance level for the series of results. Noncentral asymptotic sampling…

  11. Exact significance test for Markov order

    NASA Astrophysics Data System (ADS)

    Pethel, S. D.; Hahs, D. W.

    2014-02-01

    We describe an exact significance test of the null hypothesis that a Markov chain is nth order. The procedure utilizes surrogate data to yield an exact test statistic distribution valid for any sample size. Surrogate data are generated using a novel algorithm that guarantees, per shot, a uniform sampling from the set of sequences that exactly match the nth order properties of the observed data. Using the test, the Markov order of Tel Aviv rainfall data is examined.

  12. Extraction of mismatch negativity using a resampling-based spatial filtering method

    NASA Astrophysics Data System (ADS)

    Lin, Yanfei; Wu, Wei; Wu, Chaohua; Liu, Baolin; Gao, Xiaorong

    2013-04-01

    Objective. It is currently a challenge to extract the mismatch negativity (MMN) waveform on the basis of a small number of EEG trials, which are typically unbalanced between conditions. Approach. In order to address this issue, a method combining the techniques of resampling and spatial filtering is proposed in this paper. Specifically, the first step of the method, termed ‘resampling difference’, randomly samples the standard and deviant sweeps, and then subtracts standard sweeps from deviant sweeps. The second step of the method employs the spatial filters designed by a signal-to-noise ratio maximizer (SIM) to extract the MMN component. The SIM algorithm can maximize the signal-to-noise ratio for event-related potentials (ERPs) to improve extraction. Simulation data were used to evaluate the influence of three parameters (i.e. trial number, repeated-SIM times and sampling times) on the performance of the proposed method. Main results. Results demonstrated that it was feasible and reliable to extract the MMN waveform using the method. Finally, an oddball paradigm with auditory stimuli of different frequencies was employed to record a few trials (50 trials of deviant sweeps and 250 trials of standard sweeps) of EEG data from 11 adult subjects. Results showed that the method could effectively extract the MMN using the EEG data of each individual subject. Significance. The extracted MMN waveform has a significantly larger peak amplitude and shorter latencies in response to the more deviant stimuli than in response to the less deviant stimuli, which agreed with the MMN properties reported in previous literature using grand-averaged EEG data of multi-subjects.

  13. The insignificance of statistical significance testing

    USGS Publications Warehouse

    Johnson, Douglas H.

    1999-01-01

    Despite their use in scientific journals such as The Journal of Wildlife Management, statistical hypothesis tests add very little value to the products of research. Indeed, they frequently confuse the interpretation of data. This paper describes how statistical hypothesis tests are often viewed, and then contrasts that interpretation with the correct one. I discuss the arbitrariness of P-values, conclusions that the null hypothesis is true, power analysis, and distinctions between statistical and biological significance. Statistical hypothesis testing, in which the null hypothesis about the properties of a population is almost always known a priori to be false, is contrasted with scientific hypothesis testing, which examines a credible null hypothesis about phenomena in nature. More meaningful alternatives are briefly outlined, including estimation and confidence intervals for determining the importance of factors, decision theory for guiding actions in the face of uncertainty, and Bayesian approaches to hypothesis testing and other statistical practices.

  14. Innovative trend significance test and applications

    NASA Astrophysics Data System (ADS)

    Şen, Zekai

    2015-11-01

    Hydro-climatological time series might embed characteristics of past changes concerning climate variability in terms of shifts, cyclic fluctuations, and more significantly in the form of trends. Identification of such features from the available records is one of the prime tasks of hydrologists, climatologists, applied statisticians, or experts in related topics. Although there are different trend identification and significance tests in the literature, they require restrictive assumptions, which may not be existent in the structure of hydro-climatological time series. In this paper, a method is suggested with statistical significance test for trend identification in an innovative manner. This method has non-parametric basis without any restrictive assumption, and its application is rather simple with the concept of sub-series comparisons that are extracted from the main time series. The method provides privilege for selection of sub-temporal half periods for the comparison and, finally, generates trend on objective and quantitative manners. The necessary statistical equations are derived for innovative trend identification and statistical significance test application. The application of the proposed methodology is suggested for three time series from different parts of the world including Southern New Jersey annual temperature, Danube River annual discharge, and Tigris River Diyarbakir meteorology station annual total rainfall records. Each record has significant trend with increasing type in the New Jersey case, whereas in other two cases, decreasing trends exist.

  15. Innovative trend significance test and applications

    NASA Astrophysics Data System (ADS)

    Şen, Zekai

    2017-02-01

    Hydro-climatological time series might embed characteristics of past changes concerning climate variability in terms of shifts, cyclic fluctuations, and more significantly in the form of trends. Identification of such features from the available records is one of the prime tasks of hydrologists, climatologists, applied statisticians, or experts in related topics. Although there are different trend identification and significance tests in the literature, they require restrictive assumptions, which may not be existent in the structure of hydro-climatological time series. In this paper, a method is suggested with statistical significance test for trend identification in an innovative manner. This method has non-parametric basis without any restrictive assumption, and its application is rather simple with the concept of sub-series comparisons that are extracted from the main time series. The method provides privilege for selection of sub-temporal half periods for the comparison and, finally, generates trend on objective and quantitative manners. The necessary statistical equations are derived for innovative trend identification and statistical significance test application. The application of the proposed methodology is suggested for three time series from different parts of the world including Southern New Jersey annual temperature, Danube River annual discharge, and Tigris River Diyarbakir meteorology station annual total rainfall records. Each record has significant trend with increasing type in the New Jersey case, whereas in other two cases, decreasing trends exist.

  16. Significance testing as perverse probabilistic reasoning

    PubMed Central

    2011-01-01

    Truth claims in the medical literature rely heavily on statistical significance testing. Unfortunately, most physicians misunderstand the underlying probabilistic logic of significance tests and consequently often misinterpret their results. This near-universal misunderstanding is highlighted by means of a simple quiz which we administered to 246 physicians at two major academic hospitals, on which the proportion of incorrect responses exceeded 90%. A solid understanding of the fundamental concepts of probability theory is becoming essential to the rational interpretation of medical information. This essay provides a technically sound review of these concepts that is accessible to a medical audience. We also briefly review the debate in the cognitive sciences regarding physicians' aptitude for probabilistic inference. PMID:21356064

  17. Significance testing testate amoeba water table reconstructions

    NASA Astrophysics Data System (ADS)

    Payne, Richard J.; Babeshko, Kirill V.; van Bellen, Simon; Blackford, Jeffrey J.; Booth, Robert K.; Charman, Dan J.; Ellershaw, Megan R.; Gilbert, Daniel; Hughes, Paul D. M.; Jassey, Vincent E. J.; Lamentowicz, Łukasz; Lamentowicz, Mariusz; Malysheva, Elena A.; Mauquoy, Dmitri; Mazei, Yuri; Mitchell, Edward A. D.; Swindles, Graeme T.; Tsyganov, Andrey N.; Turner, T. Edward; Telford, Richard J.

    2016-04-01

    Transfer functions are valuable tools in palaeoecology, but their output may not always be meaningful. A recently-developed statistical test ('randomTF') offers the potential to distinguish among reconstructions which are more likely to be useful, and those less so. We applied this test to a large number of reconstructions of peatland water table depth based on testate amoebae. Contrary to our expectations, a substantial majority (25 of 30) of these reconstructions gave non-significant results (P > 0.05). The underlying reasons for this outcome are unclear. We found no significant correlation between randomTF P-value and transfer function performance, the properties of the training set and reconstruction, or measures of transfer function fit. These results give cause for concern but we believe it would be extremely premature to discount the results of non-significant reconstructions. We stress the need for more critical assessment of transfer function output, replication of results and ecologically-informed interpretation of palaeoecological data.

  18. Correcting a Significance Test for Clustering

    ERIC Educational Resources Information Center

    Hedges, Larry V.

    2007-01-01

    A common mistake in analysis of cluster randomized trials is to ignore the effect of clustering and analyze the data as if each treatment group were a simple random sample. This typically leads to an overstatement of the precision of results and anticonservative conclusions about precision and statistical significance of treatment effects. This…

  19. Statistical significance testing and clinical trials.

    PubMed

    Krause, Merton S

    2011-09-01

    The efficacy of treatments is better expressed for clinical purposes in terms of these treatments' outcome distributions and their overlapping rather than in terms of the statistical significance of these distributions' mean differences, because clinical practice is primarily concerned with the outcome of each individual client rather than with the mean of the variety of outcomes in any group of clients. Reports of the obtained outcome distributions for the comparison groups of all competently designed and executed randomized clinical trials should be publicly available no matter what the statistical significance of the mean differences among these groups, because all of these studies' outcome distributions provide clinically useful information about the efficacy of the treatments compared.

  20. Advances in Significance Testing for Cluster Detection

    NASA Astrophysics Data System (ADS)

    Coleman, Deidra Andrea

    Over the past two decades, much attention has been given to data driven project goals such as the Human Genome Project and the development of syndromic surveillance systems. A major component of these types of projects is analyzing the abundance of data. Detecting clusters within the data can be beneficial as it can lead to the identification of specified sequences of DNA nucleotides that are related to important biological functions or the locations of epidemics such as disease outbreaks or bioterrorism attacks. Cluster detection techniques require efficient and accurate hypothesis testing procedures. In this dissertation, we improve upon the hypothesis testing procedures for cluster detection by enhancing distributional theory and providing an alternative method for spatial cluster detection using syndromic surveillance data. In Chapter 2, we provide an efficient method to compute the exact distribution of the number and coverage of h-clumps of a collection of words. This method involves defining a Markov chain using a minimal deterministic automaton to reduce the number of states needed for computation. We allow words of the collection to contain other words of the collection making the method more general. We use our method to compute the distributions of the number and coverage of h-clumps in the Chi motif of H. influenza.. In Chapter 3, we provide an efficient algorithm to compute the exact distribution of multiple window discrete scan statistics for higher-order, multi-state Markovian sequences. This algorithm involves defining a Markov chain to efficiently keep track of probabilities needed to compute p-values of the statistic. We use our algorithm to identify cases where the available approximation does not perform well. We also use our algorithm to detect unusual clusters of made free throw shots by National Basketball Association players during the 2009-2010 regular season. In Chapter 4, we give a procedure to detect outbreaks using syndromic

  1. An optimal property of the repeated significance test

    PubMed Central

    Lerche, Hans Rudolf

    1986-01-01

    It is shown that the repeated significance test is a Bayes test for testing sequentially the sign of the drift of a Brownian motion. Its relation to Wald's sequential probability ratio test is studied. PMID:16593662

  2. A Priori and A Posteriori Tests of Significance for Koppa.

    ERIC Educational Resources Information Center

    Warner, Lyle G.; Gray, Louis

    1978-01-01

    The Koppa coefficient is a measure of association between two variables which have been measured dichotomously. Significance tests for comparing Koppa coefficients from multiple samples are presented. (JKS)

  3. Statistical significance test for transition matrices of atmospheric Markov chains

    NASA Technical Reports Server (NTRS)

    Vautard, Robert; Mo, Kingtse C.; Ghil, Michael

    1990-01-01

    Low-frequency variability of large-scale atmospheric dynamics can be represented schematically by a Markov chain of multiple flow regimes. This Markov chain contains useful information for the long-range forecaster, provided that the statistical significance of the associated transition matrix can be reliably tested. Monte Carlo simulation yields a very reliable significance test for the elements of this matrix. The results of this test agree with previously used empirical formulae when each cluster of maps identified as a distinct flow regime is sufficiently large and when they all contain a comparable number of maps. Monte Carlo simulation provides a more reliable way to test the statistical significance of transitions to and from small clusters. It can determine the most likely transitions, as well as the most unlikely ones, with a prescribed level of statistical significance.

  4. Testing the Difference of Correlated Agreement Coefficients for Statistical Significance

    ERIC Educational Resources Information Center

    Gwet, Kilem L.

    2016-01-01

    This article addresses the problem of testing the difference between two correlated agreement coefficients for statistical significance. A number of authors have proposed methods for testing the difference between two correlated kappa coefficients, which require either the use of resampling methods or the use of advanced statistical modeling…

  5. Test Design Considerations for Students with Significant Cognitive Disabilities

    ERIC Educational Resources Information Center

    Anderson, Daniel; Farley, Dan; Tindal, Gerald

    2015-01-01

    Students with significant cognitive disabilities present an assessment dilemma that centers on access and validity in large-scale testing programs. Typically, access is improved by eliminating construct-irrelevant barriers, while validity is improved, in part, through test standardization. In this article, one state's alternate assessment data…

  6. 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…

  7. 40 CFR Appendix IV to Part 265 - Tests for Significance

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... changes in the concentration or value of an indicator parameter in periodic ground-water samples when... then be compared to the value of the t-statistic found in a table for t-test of significance at the specified level of significance. A calculated value of t which exceeds the value of t found in the...

  8. 40 CFR Appendix IV to Part 265 - Tests for Significance

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... changes in the concentration or value of an indicator parameter in periodic ground-water samples when... then be compared to the value of the t-statistic found in a table for t-test of significance at the specified level of significance. A calculated value of t which exceeds the value of t found in the...

  9. An improved Hochberg procedure for multiple tests of significance.

    PubMed

    Rom, Dror M

    2013-02-01

    We propose a simple modification of Hochberg's step-up Bonferroni procedure for multiple tests of significance. The proposed procedure is always more powerful than Hochberg's procedure for more than two tests, and is more powerful than Hommel's procedure for three and four tests. A numerical analysis of the new procedure indicates that its Type I error is controlled under independence of the test statistics, at a level equal to or just below the nominal Type I error. Examination of various non-null configurations of hypotheses shows that the modified procedure has a power advantage over Hochberg's procedure which increases in relationship to the number of false hypotheses.

  10. Evaluating clinical significance: incorporating robust statistics with normative comparison tests.

    PubMed

    van Wieringen, Katrina; Cribbie, Robert A

    2014-05-01

    The purpose of this study was to evaluate a modified test of equivalence for conducting normative comparisons when distribution shapes are non-normal and variances are unequal. A Monte Carlo study was used to compare the empirical Type I error rates and power of the proposed Schuirmann-Yuen test of equivalence, which utilizes trimmed means, with that of the previously recommended Schuirmann and Schuirmann-Welch tests of equivalence when the assumptions of normality and variance homogeneity are satisfied, as well as when they are not satisfied. The empirical Type I error rates of the Schuirmann-Yuen were much closer to the nominal α level than those of the Schuirmann or Schuirmann-Welch tests, and the power of the Schuirmann-Yuen was substantially greater than that of the Schuirmann or Schuirmann-Welch tests when distributions were skewed or outliers were present. The Schuirmann-Yuen test is recommended for assessing clinical significance with normative comparisons.

  11. Defending the Logic of Significance Testing: A Response to Gorard

    ERIC Educational Resources Information Center

    Neale, Dave

    2015-01-01

    Recently, Stephen Gorard has outlined strong objections to the use of significance testing in social research. He has argued, first, that as the samples used in social research are almost always non-random it is not possible to use inferential statistical techniques and, second, that even if a truly random sample were achieved, the logic behind…

  12. The Use of Meta-Analytic Statistical Significance Testing

    ERIC Educational Resources Information Center

    Polanin, Joshua R.; Pigott, Terri D.

    2015-01-01

    Meta-analysis multiplicity, the concept of conducting multiple tests of statistical significance within one review, is an underdeveloped literature. We address this issue by considering how Type I errors can impact meta-analytic results, suggest how statistical power may be affected through the use of multiplicity corrections, and propose how…

  13. Significance testing - are we ready yet to abandon its use?

    PubMed

    The, Bertram

    2011-11-01

    Understanding of the damaging effects of significance testing has steadily grown. Reporting p values without dichotomizing the result to be significant or not, is not the solution. Confidence intervals are better, but are troubled by a non-intuitive interpretation, and are often misused just to see whether the null value lies within the interval. Bayesian statistics provide an alternative which solves most of these problems. Although criticized for relying on subjective models, the interpretation of a Bayesian posterior probability is more intuitive than the interpretation of a p value, and seems to be closest to intuitive patterns of human decision making. Another alternative could be using confidence interval functions (or p value functions) to display a continuum of intervals at different levels of confidence around a point estimate. Thus, better alternatives to significance testing exist. The reluctance to abandon this practice might be both preference of clinging to old habits as well as the unfamiliarity with better methods. Authors might question if using less commonly exercised, though superior, techniques will be well received by the editors, reviewers and the readership. A joint effort will be needed to abandon significance testing in clinical research in the future.

  14. Testing the aesthetic significance of the golden-section rectangle.

    PubMed

    Russell, P A

    2000-01-01

    The aesthetic significance of the golden-section rectangle was tested in two studies designed to obviate some of the criticisms of earlier experiments. In the first, employing the method of use, the mean sides-ratios of samples of paintings from five subject-matter categories (landscape, still life, head-and-shoulders portrait, upper-body portrait, full-length portrait) provided no evidence for the significance of the golden section. However, the sides ratio of portraits varied between categories in ways that were consistent with the requirements of the proportions of the subject matter. In the second study, using the method of production, participants produced the most pleasing four-sided shape, under four instruction conditions. Under a 'portrait painting' condition and a 'landscape painting' condition, the mean sides-ratios differed significantly from the golden section. Under two 'context free' geometric shape conditions--horizontal rectangle and vertical rectangle--the mean sides-ratio approximated the golden section. The results are discussed in terms of the methodological requirements for a valid test of the aesthetic significance of the golden section and the possibility that this ratio may indeed have special significance.

  15. Coagulation tests show significant differences in patients with breast cancer.

    PubMed

    Tas, Faruk; Kilic, Leyla; Duranyildiz, Derya

    2014-06-01

    Activated coagulation and fibrinolytic system in cancer patients is associated with tumor stroma formation and metastasis in different cancer types. The aim of this study is to explore the correlation of blood coagulation assays for various clinicopathologic factors in breast cancer patients. A total of 123 female breast cancer patients were enrolled into the study. All the patients were treatment naïve. Pretreatment blood coagulation tests including PT, APTT, PTA, INR, D-dimer, fibrinogen levels, and platelet counts were evaluated. Median age of diagnosis was 51 years old (range 26-82). Twenty-two percent of the group consisted of metastatic breast cancer patients. The plasma level of all coagulation tests revealed statistically significant difference between patient and control group except for PT (p<0.001 for all variables except for PT; p=0.08). Elderly age (>50 years) was associated with higher D-dimer levels (p=0.003). Metastatic patients exhibited significantly higher D-dimer values when compared with early breast cancer patients (p=0.049). Advanced tumor stage (T3 and T4) was associated with higher INR (p=0.05) and lower PTA (p=0.025). In conclusion, coagulation tests show significant differences in patients with breast cancer.

  16. Optimizing significance testing of astronomical forcing in cyclostratigraphy

    NASA Astrophysics Data System (ADS)

    Kemp, David B.

    2016-12-01

    The recognition of astronomically forced (Milankovitch) climate cycles in geological archives marked a major advance in Earth science, revealing a heartbeat within the climate system of general importance and key utility. Power spectral analysis is the primary tool used to facilitate identification of astronomical cycles in stratigraphic data, but commonly employed methods for testing the statistical significance of relatively high narrow-band variance of potential astronomical origin in spectra have been criticized for inadequately balancing the respective probabilities of type I (false positive) and type II (false negative) errors. This has led to suggestions that the importance of astronomical forcing in Earth history is overstated. It can be readily demonstrated, however, that the imperfect nature of the stratigraphic record and the quasiperiodicity of astronomical cycles sets an upper limit on the attainable significance of astronomical signals. Optimized significance testing is that which minimizes the combined probability of type I and type II errors. Numerical simulations of stratigraphically preserved astronomical signals suggest that optimum significance levels at which to reject a null hypothesis of no astronomical forcing are between 0.01 and 0.001 (i.e., 99-99.9% confidence level). This is lower than commonly employed in the literature (90-99% confidence levels). Nevertheless, in consonance with the emergent view from other scientific disciplines, fixed-value null hypothesis significance testing of power spectra is implicitly ill suited to demonstrating astronomical forcing, and the use of spectral analysis remains a difficult and subjective endeavor in the absence of additional supporting evidence.

  17. Significance of the blood beryllium lymphocyte proliferation test

    SciTech Connect

    Newman, L.S.

    1996-10-01

    The blood beryllium lymphocyte proliferation test (BeLPT) is an in vitro measure of the beryllium antigen-specific cell-mediated immune response. This response to beryllium is now understood to play a central role in the immunopathogenesis of chronic beryllium disease (CBD). Although there remain some unresolved methodologic issues with testing, the blood BeLPT has already undergone sufficient development and field assessment to lead to a number of important conclusions: (a) The BeLPT identifies beryllium sensitization and CBD earlier and better than any other clinical test presently available. (b) The CBD cases identified with the blood test are clinically significant. (c) A subset of the people identified by the BeLPT who do not yet have clinical disease will progress and require treatment with corticosteroids for impairing illness. (d) The BeLPT can be used to improve clinical diagnostic accuracy and to correct mistaken diagnoses. (e) The blood test can be used in screening large numbers of exposed workers because it is sensitive and specific and has high positive and negative predictive value for CBD. (f) In every workforce studied to date, the BeLPT has identified beryllium sensitization and CBD that had been missed by conventional screening efforts. (g) Worker populations that have been characterized using the BeLPT can help to elucidate the role of exposure genetics and dysregulated inflammation in the genesis of occupational lung disease. 28 refs., 1 tab.

  18. Significance testing of orbital forcing in deep time

    NASA Astrophysics Data System (ADS)

    Kemp, David

    2016-04-01

    The recognition of orbitally forced (Milankovitch) climate cycles in geological archives marked a paradigm shift in Earth science, revealing a heartbeat within the climate system of general importance and key utility. Resolving orbital cycles in stratigraphic data is, however, problematic owing to the imperfect stratigraphic preservation of climate signals, the masking effects of non-periodic variance, and uncertainties in the expected responses of proxy records to climate change. Power spectral analysis is the primary tool used to facilitate identification of orbital cycles in stratigraphic data, but commonly employed methods for testing the significance of relatively high narrow-band variance of potential orbital origin in spectra have been criticised for inadequately balancing the respective probabilities of type I (false positive) and type II (false negative) errors. This has led to suggestions that the importance of orbital forcing in deep time is overstated [1]. It can be readily demonstrated, however, that the imperfect nature of the stratigraphic record sets an upper limit on the attainable significance of orbital signals. Optimised significance testing is that which minimises the sum of type I and type II errors [2]. Numerical simulations of stratigraphically preserved orbital signals suggest that optimum significance levels at which to reject a null hypothesis of no orbital forcing cluster between 99% and 99.9%. This is lower than recently advocated [1], but higher than the 90-99% levels most commonly employed in the literature. Nevertheless, in consonance with the emergent view from other scientific disciplines, fixed-value null hypothesis significance testing of power spectra is likely ill suited to verifying orbital forcing. In part, this is because the experiments also indicate that the combined probability of making an error in the acceptance or rejection of an orbital hypothesis may be rather high for typical stratigraphic data, and hence the use of

  19. Significance of tests of iron nutrition in pregnancy

    PubMed Central

    Metz, J.; Turchetti, L.; Combrink, B.; Krawitz, S.

    1966-01-01

    Tests of iron and folate nutrition have been carried out in early pregnancy and at delivery in 63 Bantu females. Accepted normal values for serum iron, and percentage saturation of transferrin, but not for unsaturated iron-binding capacity, for non-pregnant subjects were found to apply equally well in pregnancy. Concomitant folate deficiency in early pregnancy did not render tests of iron deficiency less valid. The unsaturated iron-binding capacity, percentage saturation, and marrow iron stores in early pregnancy all showed a significant correlation with the haemoglobin value at term. Patients with normal marrow iron stores and a percentage saturation of transferrin of 20 or more at or before the 24th week are unlikely to become anaemic from iron deficiency during pregnancy. PMID:5909700

  20. Significant Inter-Test Reliability across Approximate Number System Assessments

    PubMed Central

    DeWind, Nicholas K.; Brannon, Elizabeth M.

    2016-01-01

    The approximate number system (ANS) is the hypothesized cognitive mechanism that allows adults, infants, and animals to enumerate large sets of items approximately. Researchers usually assess the ANS by having subjects compare two sets and indicate which is larger. Accuracy or Weber fraction is taken as an index of the acuity of the system. However, as Clayton et al. (2015) have highlighted, the stimulus parameters used when assessing the ANS vary widely. In particular, the numerical ratio between the pairs, and the way in which non-numerical features are varied often differ radically between studies. Recently, Clayton et al. (2015) found that accuracy measures derived from two commonly used stimulus sets are not significantly correlated. They argue that a lack of inter-test reliability threatens the validity of the ANS construct. Here we apply a recently developed modeling technique to the same data set. The model, by explicitly accounting for the effect of numerical ratio and non-numerical features, produces dependent measures that are less perturbed by stimulus protocol. Contrary to their conclusion we find a significant correlation in Weber fraction across the two stimulus sets. Nevertheless, in agreement with Clayton et al. (2015) we find that different protocols do indeed induce differences in numerical acuity and the degree of influence of non-numerical stimulus features. These findings highlight the need for a systematic investigation of how protocol idiosyncrasies affect ANS assessments. PMID:27014126

  1. Significant issues in proof testing: A critical appraisal

    NASA Technical Reports Server (NTRS)

    Chell, G. G.; Mcclung, R. C.; Russell, D. A.; Chang, K. J.; Donnelly, B.

    1994-01-01

    Issues which impact on the interpretation and quantification of proof test benefits are reviewed. The importance of each issue in contributing to the extra quality assurance conferred by proof testing components is discussed, particularly with respect to the application of advanced fracture mechanics concepts to enhance the flaw screening capability of a proof test analysis. Items covered include the role in proof testing of elastic-plastic fracture mechanics, ductile instability analysis, deterministic versus probabilistic analysis, single versus multiple cycle proof testing, and non-destructive examination (NDE). The effects of proof testing on subsequent service life are reviewed, particularly with regard to stress redistribution and changes in fracture behavior resulting from the overload. The importance of proof test conditions are also addressed, covering aspects related to test temperature, simulation of service environments, test media and the application of real-time NDE. The role of each issue in a proof test methodology is assessed with respect to its ability to: promote proof test practice to a state-of-the-art; aid optimization of proof test design; and increase awareness and understanding of outstanding issues.

  2. Significant issues in proof testing: A critical appraisal

    NASA Astrophysics Data System (ADS)

    Chell, G. G.; McClung, R. C.; Russell, D. A.; Chang, K. J.; Donnelly, B.

    1994-09-01

    Issues which impact on the interpretation and quantification of proof test benefits are reviewed. The importance of each issue in contributing to the extra quality assurance conferred by proof testing components is discussed, particularly with respect to the application of advanced fracture mechanics concepts to enhance the flaw screening capability of a proof test analysis. Items covered include the role in proof testing of elastic-plastic fracture mechanics, ductile instability analysis, deterministic versus probabilistic analysis, single versus multiple cycle proof testing, and non-destructive examination (NDE). The effects of proof testing on subsequent service life are reviewed, particularly with regard to stress redistribution and changes in fracture behavior resulting from the overload. The importance of proof test conditions are also addressed, covering aspects related to test temperature, simulation of service environments, test media and the application of real-time NDE. The role of each issue in a proof test methodology is assessed with respect to its ability to: promote proof test practice to a state-of-the-art; aid optimization of proof test design; and increase awareness and understanding of outstanding issues.

  3. [Significance of genetic tests in the era of personalized medicine].

    PubMed

    Molnár, Judit Mária; Magyarósi, Szilvia; Németh, György

    2013-03-01

    Due to the rapid development in genomics, genetic markers gain importance in all areas of medicine including prevention, management and therapy of patients. As a result, medicine started to shift away from evidence based procedures to a more personalized one. However, the later one requires high quality validated genetic tests. These new tests appeared as preconceptional, preimplantational, prenatal, presymptomatic, diagnostic and direct to consumer forms. Before approval such tests must be analytically and clinically validated. Broader use of these genetic tests is dependent on their price and reimbursement schemes.

  4. 40 CFR Appendix IV to Part 265 - Tests for Significance

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... compared to the initial background concentration or value of that indicator -parameter. The comparison must... (specific conductance, total organic carbon, and total organic halogen) a single-tailed Student's t-test... student's t-test involves calculation of the value of a t-statistic for each comparison of the...

  5. Significance tests for functional data with complex dependence structure

    PubMed Central

    Lahiri, Soumen N.; Carroll, Raymond J.

    2015-01-01

    We propose an L2-norm based global testing procedure for the null hypothesis that multiple group mean functions are equal, for functional data with complex dependence structure. Specifically, we consider the setting of functional data with a multilevel structure of the form groups–clusters or subjects–units, where the unit-level profiles are spatially correlated within the cluster, and the cluster-level data are independent. Orthogonal series expansions are used to approximate the group mean functions and the test statistic is estimated using the basis coefficients. The asymptotic null distribution of the test statistic is developed, under mild regularity conditions. To our knowledge this is the first work that studies hypothesis testing, when data have such complex multilevel functional and spatial structure. Two small-sample alternatives, including a novel block bootstrap for functional data, are proposed, and their performance is examined in simulation studies. The paper concludes with an illustration of a motivating experiment. PMID:26023253

  6. A significance test for graph-constrained estimation.

    PubMed

    Zhao, Sen; Shojaie, Ali

    2016-06-01

    Graph-constrained estimation methods encourage similarities among neighboring covariates presented as nodes of a graph, and can result in more accurate estimates, especially in high-dimensional settings. Variable selection approaches can then be utilized to select a subset of variables that are associated with the response. However, existing procedures do not provide measures of uncertainty of estimates. Further, the vast majority of existing approaches assume that available graph accurately captures the association among covariates; violations to this assumption could severely hurt the reliability of the resulting estimates. In this article, we present a new inference framework, called the Grace test, which produces coefficient estimates and corresponding p-values by incorporating the external graph information. We show, both theoretically and via numerical studies, that the proposed method asymptotically controls the type-I error rate regardless of the choice of the graph. We also show that when the underlying graph is informative, the Grace test is asymptotically more powerful than similar tests that ignore the external information. We study the power properties of the proposed test when the graph is not fully informative and develop a more powerful Grace-ridge test for such settings. Our numerical studies show that as long as the graph is reasonably informative, the proposed inference procedures deliver improved statistical power over existing methods that ignore external information.

  7. Interpretation of Statistical Significance Testing: A Matter of Perspective.

    ERIC Educational Resources Information Center

    McClure, John; Suen, Hoi K.

    1994-01-01

    This article compares three models that have been the foundation for approaches to the analysis of statistical significance in early childhood research--the Fisherian and the Neyman-Pearson models (both considered "classical" approaches), and the Bayesian model. The article concludes that all three models have a place in the analysis of research…

  8. Testing Mediation in Structural Equation Modeling: The Effectiveness of the Test of Joint Significance

    ERIC Educational Resources Information Center

    Leth-Steensen, Craig; Gallitto, Elena

    2016-01-01

    A large number of approaches have been proposed for estimating and testing the significance of indirect effects in mediation models. In this study, four sets of Monte Carlo simulations involving full latent variable structural equation models were run in order to contrast the effectiveness of the currently popular bias-corrected bootstrapping…

  9. Review of null hypothesis significance testing in the ophthalmic literature: are most 'significant' P values false positives?

    PubMed

    Sanfilippo, Paul G; Casson, Robert J; Yazar, Seyhan; Mackey, David A; Hewitt, Alex W

    2016-01-01

    P values associated with null hypothesis significance testing (NHST) are almost universal in the ophthalmic literature. A P value < 0.05 is traditionally considered 'significant'. This concept may deflect further thought about the veracity of the results. P values influence the publishability of the data and have flow-on effects for funding success and the direction of future research. Despite their importance, the problems inherent in P values have been recognized since their inception, and in more recent years have been increasingly highlighted in some scientific fields. In this review, we aim to bring the problems associated with P values and NHST to the attention of the ophthalmic research community. We do not offer a universal solution to the problem of determining the veracity of a scientific claim; however, we demonstrate the need for caution in interpreting 'significant' P values by performing a Bayesian re-analysis of t-tests in the ophthalmic literature.

  10. Providing the Nation a Significant "High-Test Peroxide" Propulsion Test Capability

    NASA Technical Reports Server (NTRS)

    Bruce, R.; Taylor, G.; Beckmeyer, D.; Warren, S.; Dracon, S.; Powell, B.; Goodwin, D.; Rieder, P.; Nichols, R.

    1999-01-01

    Renewed interest in high-test peroxide, as a propellant, required the development of a facility capable of testing rocket propulsion systems. The development of this capability at the NASA Stennis Space Center (SSC), MS, focused on meeting this requirement. The challenges, accomplishments, and lessons learned associated with developing the SSC E3 Test Facility's high-test peroxide capability are presented herein.

  11. Patterns of Statewide Test Participation for Students with Significant Cognitive Disabilities

    ERIC Educational Resources Information Center

    Saven, Jessica L.; Anderson, Daniel; Nese, Joseph F. T.; Farley, Dan; Tindal, Gerald

    2016-01-01

    Students with significant cognitive disabilities are eligible to participate in two statewide testing options for accountability: alternate assessments or general assessments with appropriate accommodations. Participation guidelines are generally quite vague, leading to students "switching" test participation between years. In this…

  12. Significance testing of rules in rule-based models of human problem solving

    NASA Technical Reports Server (NTRS)

    Lewis, C. M.; Hammer, J. M.

    1986-01-01

    Rule-based models of human problem solving have typically not been tested for statistical significance. Three methods of testing rules - analysis of variance, randomization, and contingency tables - are presented. Advantages and disadvantages of the methods are also described.

  13. Statistical Significance Testing in Second Language Research: Basic Problems and Suggestions for Reform

    ERIC Educational Resources Information Center

    Norris, John M.

    2015-01-01

    Traditions of statistical significance testing in second language (L2) quantitative research are strongly entrenched in how researchers design studies, select analyses, and interpret results. However, statistical significance tests using "p" values are commonly misinterpreted by researchers, reviewers, readers, and others, leading to…

  14. "What If" Analyses: Ways to Interpret Statistical Significance Test Results Using EXCEL or "R"

    ERIC Educational Resources Information Center

    Ozturk, Elif

    2012-01-01

    The present paper aims to review two motivations to conduct "what if" analyses using Excel and "R" to understand the statistical significance tests through the sample size context. "What if" analyses can be used to teach students what statistical significance tests really do and in applied research either prospectively to estimate what sample size…

  15. Understanding the Sampling Distribution and Its Use in Testing Statistical Significance.

    ERIC Educational Resources Information Center

    Breunig, Nancy A.

    Despite the increasing criticism of statistical significance testing by researchers, particularly in the publication of the 1994 American Psychological Association's style manual, statistical significance test results are still popular in journal articles. For this reason, it remains important to understand the logic of inferential statistics. A…

  16. A Review of Post-1994 Literature on Whether Statistical Significance Tests Should Be Banned.

    ERIC Educational Resources Information Center

    Sullivan, Jeremy R.

    This paper summarizes the literature regarding statistical significance testing with an emphasis on: (1) the post-1994 literature in various disciplines; (2) alternatives to statistical significance testing; and (3) literature exploring why researchers have demonstrably failed to be influenced by the 1994 American Psychological Association…

  17. The Historical Growth of Statistical Significance Testing in Psychology--and Its Future Prospects.

    ERIC Educational Resources Information Center

    Hubbard, Raymond; Ryan, Patricia A.

    2000-01-01

    Examined the historical growth in the popularity of statistical significance testing using a random sample of data from 12 American Psychological Association journals. Results replicate and extend findings from a study that used only one such journal. Discusses the role of statistical significance testing and the use of replication and…

  18. Tests of English Language as Significant Thresholds for College-Bound Chinese and the Washback of Test-Preparation

    ERIC Educational Resources Information Center

    Matoush, Marylou M.; Fu, Danling

    2012-01-01

    Tests of English language mark significantly high thresholds for all college-bound students in the People's Republic of China. Many Chinese students hope to seek their fortunes at universities in the United States, or other English speaking countries. These students spend long hours, year after year, in test-preparation centres in order to develop…

  19. The Use (and Misuse) of Statistical Significance Testing: Some Recommendations for Improved Editorial Policy and Practice.

    ERIC Educational Resources Information Center

    Thompson, Bruce

    This paper evaluates the logic underlying various criticisms of statistical significance testing and makes specific recommendations for scientific and editorial practice that might better increase the knowledge base. Reliance on the traditional hypothesis testing model has led to a major bias against nonsignificant results and to misinterpretation…

  20. Use of power analysis to develop detectable significance criteria for sea urchin toxicity tests

    USGS Publications Warehouse

    Carr, R.S.; Biedenbach, J.M.

    1999-01-01

    When sufficient data are available, the statistical power of a test can be determined using power analysis procedures. The term “detectable significance” has been coined to refer to this criterion based on power analysis and past performance of a test. This power analysis procedure has been performed with sea urchin (Arbacia punctulata) fertilization and embryological development data from sediment porewater toxicity tests. Data from 3100 and 2295 tests for the fertilization and embryological development tests, respectively, were used to calculate the criteria and regression equations describing the power curves. Using Dunnett's test, a minimum significant difference (MSD) (β = 0.05) of 15.5% and 19% for the fertilization test, and 16.4% and 20.6% for the embryological development test, for α ≤ 0.05 and α ≤ 0.01, respectively, were determined. The use of this second criterion reduces type I (false positive) errors and helps to establish a critical level of difference based on the past performance of the test.

  1. RV-coefficient and its significance test in mapping brain functional connectivity

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Tian, Jie; Li, Jun; Zhao, Jizheng

    2009-02-01

    The statistic of RV-coefficient is a good substitute for the Pearson correlation coefficient to measure the temporal similarity of two local brain regions. However, the hypothesis test of RV-coefficient is a hard problem which limits its application. This paper discussed the problem in details. Since the distribution of RV-coefficient is unknown, we do not know a critical p-value to statistically test its significance. We proposed a new strategy to test the significance of RV calculated from fMRI. In order to approximate the p-value, we elicited the first two moments of the population permutation distribution of RV; we then derived a formula to more closely approximate the normal distribution with these transformed statistics. These transformations of statistics are suggested for a precise approximation to the permutational p-value even under large number of observations. This strategy of test can greatly reduce the computational complexity and avoid "calculation catastrophe", we then use the statistic of RV to extract the map of functional connectivity from fMRI and test its significance with the strategy proposed here.

  2. A Communication Researchers' Guide to Null Hypothesis Significance Testing and Alternatives

    ERIC Educational Resources Information Center

    Levine, Timothy R.; Weber, Rene; Park, Hee Sun; Hullett, Craig R.

    2008-01-01

    This paper offers a practical guide to use null hypotheses significance testing and its alternatives. The focus is on improving the quality of statistical inference in quantitative communication research. More consistent reporting of descriptive statistics, estimates of effect size, confidence intervals around effect sizes, and increasing the…

  3. A Critical Assessment of Null Hypothesis Significance Testing in Quantitative Communication Research

    ERIC Educational Resources Information Center

    Levine, Timothy R.; Weber, Rene; Hullett, Craig; Park, Hee Sun; Lindsey, Lisa L. Massi

    2008-01-01

    Null hypothesis significance testing (NHST) is the most widely accepted and frequently used approach to statistical inference in quantitative communication research. NHST, however, is highly controversial, and several serious problems with the approach have been identified. This paper reviews NHST and the controversy surrounding it. Commonly…

  4. Visual mining methods for RNA-Seq data: data structure, dispersion estimation and significance testing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an analysis of RNA-Seq data from soybeans, initial significance testing using one software package produced very different gene lists from those yielded by another. How can this happen? This paper demonstrates how the disparities between the results were investigated, and can be explained. This t...

  5. Alphas and Asterisks: The Development of Statistical Significance Testing Standards in Sociology

    ERIC Educational Resources Information Center

    Leahey, Erin

    2005-01-01

    In this paper, I trace the development of statistical significance testing standards in sociology by analyzing data from articles published in two prestigious sociology journals between 1935 and 2000. I focus on the role of two key elements in the diffusion literature, contagion and rationality, as well as the role of institutional factors. I…

  6. 77 FR 19861 - Certain Polybrominated Diphenylethers; Significant New Use Rule and Test Rule

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ..., or any combination of these chemical substances resulting from a chemical reaction, as a significant..., Chemical Control Division, Office of Pollution Prevention and Toxics, Environmental Protection Agency, 1200....john@epa.gov . For technical information on the test rule, contact: Catherine Roman, Chemical...

  7. Uses and Abuses of Statistical Significance Tests and Other Statistical Resources: A Comparative Study

    ERIC Educational Resources Information Center

    Monterde-i-Bort, Hector; Frias-Navarro, Dolores; Pascual-Llobell, Juan

    2010-01-01

    The empirical study we present here deals with a pedagogical issue that has not been thoroughly explored up until now in our field. Previous empirical studies in other sectors have identified the opinions of researchers about this topic, showing that completely unacceptable interpretations have been made of significance tests and other statistical…

  8. Interpreting Statistical Significance Test Results: A Proposed New "What If" Method.

    ERIC Educational Resources Information Center

    Kieffer, Kevin M.; Thompson, Bruce

    As the 1994 publication manual of the American Psychological Association emphasized, "p" values are affected by sample size. As a result, it can be helpful to interpret the results of statistical significant tests in a sample size context by conducting so-called "what if" analyses. However, these methods can be inaccurate…

  9. Recent Literature on Whether Statistical Significance Tests Should or Should Not Be Banned.

    ERIC Educational Resources Information Center

    Deegear, James

    This paper summarizes the literature regarding statistical significant testing with an emphasis on recent literature in various discipline and literature exploring why researchers have demonstrably failed to be influenced by the American Psychological Association publication manual's encouragement to report effect sizes. Also considered are…

  10. Significance tests for the wavelet power and the wavelet power spectrum

    NASA Astrophysics Data System (ADS)

    Ge, Z.

    2007-11-01

    Significance tests usually address the issue how to distinguish statistically significant results from those due to pure randomness when only one sample of the population is studied. This issue is also important when the results obtained using the wavelet analysis are to be interpreted. Torrence and Compo (1998) is one of the earliest works that has systematically discussed this problem. Their results, however, were based on Monte Carlo simulations, and hence, failed to unveil many interesting and important properties of the wavelet analysis. In the present work, the sampling distributions of the wavelet power and power spectrum of a Gaussian White Noise (GWN) were derived in a rigorous statistical framework, through which the significance tests for these two fundamental quantities in the wavelet analysis were established. It was found that the results given by Torrence and Compo (1998) are numerically accurate when adjusted by a factor of the sampling period, while some of their statements require reassessment. More importantly, the sampling distribution of the wavelet power spectrum of a GWN was found to be highly dependent on the local covariance structure of the wavelets, a fact that makes the significance levels intimately related to the specific wavelet family. In addition to simulated signals, the significance tests developed in this work were demonstrated on an actual wave elevation time series observed from a buoy on Lake Michigan. In this simple application in geophysics, we showed how proper significance tests helped to sort out physically meaningful peaks from those created by random noise. The derivations in the present work can be readily extended to other wavelet-based quantities or analyses using other wavelet families.

  11. Are all significant P values created equal? The analogy between diagnostic tests and clinical research.

    PubMed

    Browner, W S; Newman, T B

    1987-05-08

    Just as diagnostic tests are most helpful in light of the clinical presentation, statistical tests are most useful in the context of scientific knowledge. Knowing the specificity and sensitivity of a diagnostic test is necessary, but insufficient: the clinician must also estimate the prior probability of the disease. In the same way, knowing the P value and power, or the confidence interval, for the results of a research study is necessary but insufficient: the reader must estimate the prior probability that the research hypothesis is true. Just as a positive diagnostic test does not mean that a patient has the disease, especially if the clinical picture suggests otherwise, a significant P value does not mean that a research hypothesis is correct, especially if it is inconsistent with current knowledge. Powerful studies are like sensitive tests in that they can be especially useful when the results are negative. Very low P values are like very specific tests; both result in few false-positive results due to chance. This Bayesian approach can clarify much of the confusion surrounding the use and interpretation of statistical tests.

  12. A common misapplication of statistical inference: Nuisance control with null-hypothesis significance tests.

    PubMed

    Sassenhagen, Jona; Alday, Phillip M

    2016-11-01

    Experimental research on behavior and cognition frequently rests on stimulus or subject selection where not all characteristics can be fully controlled, even when attempting strict matching. For example, when contrasting patients to controls, variables such as intelligence or socioeconomic status are often correlated with patient status. Similarly, when presenting word stimuli, variables such as word frequency are often correlated with primary variables of interest. One procedure very commonly employed to control for such nuisance effects is conducting inferential tests on confounding stimulus or subject characteristics. For example, if word length is not significantly different for two stimulus sets, they are considered as matched for word length. Such a test has high error rates and is conceptually misguided. It reflects a common misunderstanding of statistical tests: interpreting significance not to refer to inference about a particular population parameter, but about 1. the sample in question, 2. the practical relevance of a sample difference (so that a nonsignificant test is taken to indicate evidence for the absence of relevant differences). We show inferential testing for assessing nuisance effects to be inappropriate both pragmatically and philosophically, present a survey showing its high prevalence, and briefly discuss an alternative in the form of regression including nuisance variables.

  13. Applications and statistical properties of minimum significant difference-based criterion testing in a toxicity testing program

    SciTech Connect

    Wang, Q.; Denton, D.L.; Shukla, R.

    2000-01-01

    As a follow up to the recommendations of the September 1995 SETAC Pellston Workshop on Whole Effluent Toxicity (WET) on test methods and appropriate endpoints, this paper will discuss the applications and statistical properties of using a statistical criterion of minimum significant difference (MSD). The authors examined the upper limits of acceptable MSDs as acceptance criterion in the case of normally distributed data. The implications of this approach are examined in terms of false negative rate as well as false positive rate. Results indicated that the proposed approach has reasonable statistical properties. Reproductive data from short-term chronic WET test with Ceriodaphnia dubia tests were used to demonstrate the applications of the proposed approach. The data were collected by the North Carolina Department of Environment, Health, and Natural Resources (Raleigh, NC, USA) as part of their National Pollutant Discharge Elimination System program.

  14. Setting an Optimal α That Minimizes Errors in Null Hypothesis Significance Tests

    PubMed Central

    Mudge, Joseph F.; Baker, Leanne F.; Edge, Christopher B.; Houlahan, Jeff E.

    2012-01-01

    Null hypothesis significance testing has been under attack in recent years, partly owing to the arbitrary nature of setting α (the decision-making threshold and probability of Type I error) at a constant value, usually 0.05. If the goal of null hypothesis testing is to present conclusions in which we have the highest possible confidence, then the only logical decision-making threshold is the value that minimizes the probability (or occasionally, cost) of making errors. Setting α to minimize the combination of Type I and Type II error at a critical effect size can easily be accomplished for traditional statistical tests by calculating the α associated with the minimum average of α and β at the critical effect size. This technique also has the flexibility to incorporate prior probabilities of null and alternate hypotheses and/or relative costs of Type I and Type II errors, if known. Using an optimal α results in stronger scientific inferences because it estimates and minimizes both Type I errors and relevant Type II errors for a test. It also results in greater transparency concerning assumptions about relevant effect size(s) and the relative costs of Type I and II errors. By contrast, the use of α = 0.05 results in arbitrary decisions about what effect sizes will likely be considered significant, if real, and results in arbitrary amounts of Type II error for meaningful potential effect sizes. We cannot identify a rationale for continuing to arbitrarily use α = 0.05 for null hypothesis significance tests in any field, when it is possible to determine an optimal α. PMID:22389720

  15. Microsatellite allele sizes: a simple test to assess their significance on genetic differentiation.

    PubMed Central

    Hardy, Olivier J; Charbonnel, Nathalie; Fréville, Hélène; Heuertz, Myriam

    2003-01-01

    The mutation process at microsatellite loci typically occurs at high rates and with stepwise changes in allele sizes, features that may introduce bias when using classical measures of population differentiation based on allele identity (e.g., F(ST), Nei's Ds genetic distance). Allele size-based measures of differentiation, assuming a stepwise mutation process [e.g., Slatkin's R(ST), Goldstein et al.'s (deltamu)(2)], may better reflect differentiation at microsatellite loci, but they suffer high sampling variance. The relative efficiency of allele size- vs. allele identity-based statistics depends on the relative contributions of mutations vs. drift to population differentiation. We present a simple test based on a randomization procedure of allele sizes to determine whether stepwise-like mutations contributed to genetic differentiation. This test can be applied to any microsatellite data set designed to assess population differentiation and can be interpreted as testing whether F(ST) = R(ST). Computer simulations show that the test efficiently identifies which of F(ST) or R(ST) estimates has the lowest mean square error. A significant test, implying that R(ST) performs better than F(ST), is obtained when the mutation rate, mu, for a stepwise mutation process is (a) >/= m in an island model (m being the migration rate among populations) or (b) >/= 1/t in the case of isolated populations (t being the number of generations since population divergence). The test also informs on the efficiency of other statistics used in phylogenetical reconstruction [e.g., Ds and (deltamu)(2)], a nonsignificant test meaning that allele identity-based statistics perform better than allele size-based ones. This test can also provide insights into the evolutionary history of populations, revealing, for example, phylogeographic patterns, as illustrated by applying it on three published data sets. PMID:12702690

  16. Using the Bootstrap Method for a Statistical Significance Test of Differences between Summary Histograms

    NASA Technical Reports Server (NTRS)

    Xu, Kuan-Man

    2006-01-01

    A new method is proposed to compare statistical differences between summary histograms, which are the histograms summed over a large ensemble of individual histograms. It consists of choosing a distance statistic for measuring the difference between summary histograms and using a bootstrap procedure to calculate the statistical significance level. Bootstrapping is an approach to statistical inference that makes few assumptions about the underlying probability distribution that describes the data. Three distance statistics are compared in this study. They are the Euclidean distance, the Jeffries-Matusita distance and the Kuiper distance. The data used in testing the bootstrap method are satellite measurements of cloud systems called cloud objects. Each cloud object is defined as a contiguous region/patch composed of individual footprints or fields of view. A histogram of measured values over footprints is generated for each parameter of each cloud object and then summary histograms are accumulated over all individual histograms in a given cloud-object size category. The results of statistical hypothesis tests using all three distances as test statistics are generally similar, indicating the validity of the proposed method. The Euclidean distance is determined to be most suitable after comparing the statistical tests of several parameters with distinct probability distributions among three cloud-object size categories. Impacts on the statistical significance levels resulting from differences in the total lengths of satellite footprint data between two size categories are also discussed.

  17. Significance tests for the wavelet cross spectrum and wavelet linear coherence

    NASA Astrophysics Data System (ADS)

    Ge, Z.

    2008-12-01

    This work attempts to develop significance tests for the wavelet cross spectrum and the wavelet linear coherence as a follow-up study on Ge (2007). Conventional approaches that are used by Torrence and Compo (1998) based on stationary background noise time series were used here in estimating the sampling distributions of the wavelet cross spectrum and the wavelet linear coherence. The sampling distributions are then used for establishing significance levels for these two wavelet-based quantities. In addition to these two wavelet quantities, properties of the phase angle of the wavelet cross spectrum of, or the phase difference between, two Gaussian white noise series are discussed. It is found that the tangent of the principal part of the phase angle approximately has a standard Cauchy distribution and the phase angle is uniformly distributed, which makes it impossible to establish significance levels for the phase angle. The simulated signals clearly show that, when there is no linear relation between the two analysed signals, the phase angle disperses into the entire range of [-π,π] with fairly high probabilities for values close to ±π to occur. Conversely, when linear relations are present, the phase angle of the wavelet cross spectrum settles around an associated value with considerably reduced fluctuations. When two signals are linearly coupled, their wavelet linear coherence will attain values close to one. The significance test of the wavelet linear coherence can therefore be used to complement the inspection of the phase angle of the wavelet cross spectrum. The developed significance tests are also applied to actual data sets, simultaneously recorded wind speed and wave elevation series measured from a NOAA buoy on Lake Michigan. Significance levels of the wavelet cross spectrum and the wavelet linear coherence between the winds and the waves reasonably separated meaningful peaks from those generated by randomness in the data set. As with simulated

  18. From statistical non-significance to statistical equivalence: An alternative approach for whole effluent toxicity testing

    SciTech Connect

    Shukla, R.; Yu Daohai; Fulk, F.

    1995-12-31

    Short-term toxicity tests with aquatic organisms are a valuable measurement tool in the assessment of the toxicity of effluents, environmental samples and single chemicals. Currently toxicity tests are utilized in a wide range of US EPA regulatory activities including effluent discharge compliance. In the current approach for determining the No Observed Effect Concentration, an effluent concentration is presumed safe if there is no statistically significant difference in toxicant response versus control response. The conclusion of a safe concentration may be due to the fact that it truly is safe, or alternatively, that the ability of the statistical test to detect an effect, given its existence, is inadequate. Results of research of a new statistical approach, the basis of which is to move away from a demonstration of no difference to a demonstration of equivalence, will be discussed. The concept of observed confidence distributions, first suggested by Cox, is proposed as a measure of the strength of evidence for practically equivalent responses between a given effluent concentration and the control. The research included determination of intervals of practically equivalent responses as a function of the variability of control response. The approach is illustrated using reproductive data from tests with Ceriodaphnia dubia and survival and growth data from tests with fathead minnow. The data are from the US EPA`s National Reference Toxicant Database.

  19. Confidence intervals permit, but do not guarantee, better inference than statistical significance testing.

    PubMed

    Coulson, Melissa; Healey, Michelle; Fidler, Fiona; Cumming, Geoff

    2010-01-01

    A statistically significant result, and a non-significant result may differ little, although significance status may tempt an interpretation of difference. Two studies are reported that compared interpretation of such results presented using null hypothesis significance testing (NHST), or confidence intervals (CIs). Authors of articles published in psychology, behavioral neuroscience, and medical journals were asked, via email, to interpret two fictitious studies that found similar results, one statistically significant, and the other non-significant. Responses from 330 authors varied greatly, but interpretation was generally poor, whether results were presented as CIs or using NHST. However, when interpreting CIs respondents who mentioned NHST were 60% likely to conclude, unjustifiably, the two results conflicted, whereas those who interpreted CIs without reference to NHST were 95% likely to conclude, justifiably, the two results were consistent. Findings were generally similar for all three disciplines. An email survey of academic psychologists confirmed that CIs elicit better interpretations if NHST is not invoked. Improved statistical inference can result from encouragement of meta-analytic thinking and use of CIs but, for full benefit, such highly desirable statistical reform requires also that researchers interpret CIs without recourse to NHST.

  20. Confidence Intervals Permit, but Do Not Guarantee, Better Inference than Statistical Significance Testing

    PubMed Central

    Coulson, Melissa; Healey, Michelle; Fidler, Fiona; Cumming, Geoff

    2010-01-01

    A statistically significant result, and a non-significant result may differ little, although significance status may tempt an interpretation of difference. Two studies are reported that compared interpretation of such results presented using null hypothesis significance testing (NHST), or confidence intervals (CIs). Authors of articles published in psychology, behavioral neuroscience, and medical journals were asked, via email, to interpret two fictitious studies that found similar results, one statistically significant, and the other non-significant. Responses from 330 authors varied greatly, but interpretation was generally poor, whether results were presented as CIs or using NHST. However, when interpreting CIs respondents who mentioned NHST were 60% likely to conclude, unjustifiably, the two results conflicted, whereas those who interpreted CIs without reference to NHST were 95% likely to conclude, justifiably, the two results were consistent. Findings were generally similar for all three disciplines. An email survey of academic psychologists confirmed that CIs elicit better interpretations if NHST is not invoked. Improved statistical inference can result from encouragement of meta-analytic thinking and use of CIs but, for full benefit, such highly desirable statistical reform requires also that researchers interpret CIs without recourse to NHST. PMID:21607077

  1. Many tests of significance: new methods for controlling type I errors.

    PubMed

    Keselman, H J; Miller, Charles W; Holland, Burt

    2011-12-01

    There have been many discussions of how Type I errors should be controlled when many hypotheses are tested (e.g., all possible comparisons of means, correlations, proportions, the coefficients in hierarchical models, etc.). By and large, researchers have adopted familywise (FWER) control, though this practice certainly is not universal. Familywise control is intended to deal with the multiplicity issue of computing many tests of significance, yet such control is conservative--that is, less powerful--compared to per test/hypothesis control. The purpose of our article is to introduce the readership, particularly those readers familiar with issues related to controlling Type I errors when many tests of significance are computed, to newer methods that provide protection from the effects of multiple testing, yet are more powerful than familywise controlling methods. Specifically, we introduce a number of procedures that control the k-FWER. These methods--say, 2-FWER instead of 1-FWER (i.e., FWER)--are equivalent to specifying that the probability of 2 or more false rejections is controlled at .05, whereas FWER controls the probability of any (i.e., 1 or more) false rejections at .05. 2-FWER implicitly tolerates 1 false rejection and makes no explicit attempt to control the probability of its occurrence, unlike FWER, which tolerates no false rejections at all. More generally, k-FWER tolerates k - 1 false rejections, but controls the probability of k or more false rejections at α =.05. We demonstrate with two published data sets how more hypotheses can be rejected with k-FWER methods compared to FWER control.

  2. Significant release of shear energy of the North Korean nuclear test on February 12, 2013

    NASA Astrophysics Data System (ADS)

    Barth, Andreas

    2014-07-01

    On February 12, 2013 the Democratic People's Republic of Korea (DPRK) carried out an announced nuclear test, which was the third after tests conducted in 2006 and 2009. An important task in discriminating a man-made explosion and a natural tectonic earthquake is the analysis of seismic waveforms. To determine the isotropic and non-isotropic characteristics of the detonation source, I invert long-period seismic data for the full seismic moment tensor to match the observed seismic signals by synthetic waveforms based on a 3D Earth model. Here, I show that the inversion of long-period seismic data of the 2013 test reveals a clear explosive (isotropic) component combined with a significant release of shear energy by the double-couple part of the moment tensor. While the isotropic part of the nuclear test in 2009 was similar to that in 2013, the double-couple part was lower by a factor of 0.55 compared to the explosion in 2013. Moreover, the ratio of the isotropic seismic moments of the 2013 and 2009 nuclear tests is 1.4 ± 0.1 and lower than published estimations of the yield ratio, which indicates the importance of considering the release of shear energy. The determined orientation of the double-couple fault plane is parallel to the dominating geologic fault structures NNE-SSW to NE-SW, but the calculated normal faulting mechanism does not correspond to the general tectonic strike-slip regime. Thus, explanations for the enhanced release of shear energy might be induced dip-slip motion pre-stressed by the previous test or near source damaging effects due to a changed containment of the nuclear explosion.

  3. Significant-Loophole-Free Test of Bell's Theorem with Entangled Photons

    NASA Astrophysics Data System (ADS)

    Giustina, Marissa; Versteegh, Marijn A. M.; Wengerowsky, Sören; Handsteiner, Johannes; Hochrainer, Armin; Phelan, Kevin; Steinlechner, Fabian; Kofler, Johannes; Larsson, Jan-Åke; Abellán, Carlos; Amaya, Waldimar; Pruneri, Valerio; Mitchell, Morgan W.; Beyer, Jörn; Gerrits, Thomas; Lita, Adriana E.; Shalm, Lynden K.; Nam, Sae Woo; Scheidl, Thomas; Ursin, Rupert; Wittmann, Bernhard; Zeilinger, Anton

    2015-12-01

    Local realism is the worldview in which physical properties of objects exist independently of measurement and where physical influences cannot travel faster than the speed of light. Bell's theorem states that this worldview is incompatible with the predictions of quantum mechanics, as is expressed in Bell's inequalities. Previous experiments convincingly supported the quantum predictions. Yet, every experiment requires assumptions that provide loopholes for a local realist explanation. Here, we report a Bell test that closes the most significant of these loopholes simultaneously. Using a well-optimized source of entangled photons, rapid setting generation, and highly efficient superconducting detectors, we observe a violation of a Bell inequality with high statistical significance. The purely statistical probability of our results to occur under local realism does not exceed 3.74 ×10-31 , corresponding to an 11.5 standard deviation effect.

  4. Clinical significance of the mixing test in laboratory diagnoses of lupus anticoagulant: the fate of the mixing test in integrated lupus anticoagulant test systems.

    PubMed

    Hong, Sung Kuk; Hwang, Sang Mee; Kim, Ji-Eun; Kim, Hyun Kyung

    2012-12-01

    The mixing test is used to determine the presence of inhibitors in laboratory diagnoses of lupus anticoagulant. Updated international guidelines state that an integrated lupus anticoagulant test system does not require the mixing test; an appraisal of the mixing tests in integrated lupus anticoagulant test systems is, therefore, required. We investigated the clinical relevance of mixing tests by using the best cutoff value of the mixing test through thrombotic risk analysis. A retrospective analysis was performed on 525 specimens with positive screening tests by using two integrated lupus anticoagulant tests: diluted Russell's Viper venom (dRVVT) and silica clotting time. The diagnostic performance of two interpretation formulas (percentage correction, Rosner index) was assessed, and the thrombotic risk of a subgroup based on the mixing results was investigated. Finally, the thrombotic risk of lupus anticoagulant positivity based on the integrated lupus anticoagulant test system procedures was assessed for the appraisal of mixing test exclusion in integrated lupus anticoagulant test systems. The best cutoff values of mixing test interpretation methods based on dRVVT were as follows: 60.1% for percentage correction and 15.7 for Rosner index. There was no substantial difference in the thrombotic risk between percentage correction and the Rosner index. The mixing-positive group showed a higher lupus anticoagulant titer and higher thrombotic risk than the mixing-negative group. However, even the mixing-negative group carried a significant risk of thrombosis. Finally, lupus anticoagulant positivity determined by the updated two-step procedure (screening and confirmation tests) showed higher thrombotic risk than that determined by the traditional three-step procedure (screening, mixing, and confirmation tests). Although a positive mixing result can predict a high risk of thrombosis, negative mixing results are also associated with a substantial thrombotic risk. The

  5. Association between micronucleus frequency and cervical intraepithelial neoplasia grade in Thinprep cytological test and its significance.

    PubMed

    Shi, Yong-Hua; Wang, Bo-Wei; Tuokan, Talaf; Li, Qiao-Zhi; Zhang, Ya-Jing

    2015-01-01

    A micronucleus is an additional small nucleus formed due to chromosomes or chromosomal fragments fail to be incorporated into the nucleus during cell division. In this study, we assessed the utility of micronucleus counting as a screening tool in cervical precancerous lesions in Thinprep cytological test smears under oil immersion. High risk HPV was also detected by hybrid capture-2 in Thinprep cytological test smears. Our results showed that micronucleus counting was significantly higher in high-grade squamous intraepithelial lesion (HSIL) and invasive carcinoma cases compared to low-grade squamous intraepithelial lesion (LSIL) and non-neoplastic cases. Receiver operating characteristic (ROC) curve analysis revealed that micronucleus counting possessed a high degree of sensitivity and specificity for identifying HSIL and invasive carcinoma. Cut-off of 7.5 for MN counting gave a sensitivity of 89.6% and a specificity of 66.7% (P = 0.024 and AUC = 0.892) for detecting HSIL and invasive carcinoma lesions. Multiple linear regression analysis showed that only HSIL and invasive cancer lesions not age, duration of marital life and number of pregnancy are significantly associated with MN counting. The positive rate of high risk HPV was distinctly higher in LSIL, HSIL and invasive cancer than that in non-neoplstic categories. In conclusions, MN evaluation may be viewed as an effective biomarker for cervical cancer screening. The combination of MN count with HPV DNA detection and TCT may serve as an effective means to screen precancerous cervical lesions in most developing nations.

  6. Clinical features of congenital adrenal insufficiency including growth patterns and significance of ACTH stimulation test.

    PubMed

    Koh, Ji Won; Kim, Gu Hwan; Yoo, Han Wook; Yu, Jeesuk

    2013-11-01

    Congenital adrenal insufficiency is caused by specific genetic mutations. Early suspicion and definite diagnosis are crucial because the disease can precipitate a life-threatening hypovolemic shock without prompt treatment. This study was designed to understand the clinical manifestations including growth patterns and to find the usefulness of ACTH stimulation test. Sixteen patients with confirmed genotyping were subdivided into three groups according to the genetic study results: congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH, n=11), congenital lipoid adrenal hyperplasia (n=3) and X-linked adrenal hypoplasia congenita (n=2). Bone age advancement was prominent in patients with CAH especially after 60 months of chronologic age (n=6, 67%). They were diagnosed in older ages in group with bone age advancement (P<0.05). Comorbid conditions such as obesity, mental retardation, and central precocious puberty were also prominent in this group. In conclusion, this study showed the importance of understanding the clinical symptoms as well as genetic analysis for early diagnosis and management of congenital adrenal insufficiency. ACTH stimulation test played an important role to support the diagnosis and serum 17-hydroxyprogesterone levels were significantly elevated in all of the CAH patients. The test will be important for monitoring growth and puberty during follow up of patients with congenital adrenal insufficiency.

  7. Clinical Features of Congenital Adrenal Insufficiency Including Growth Patterns and Significance of ACTH Stimulation Test

    PubMed Central

    Koh, Ji Won; Kim, Gu Hwan; Yoo, Han Wook

    2013-01-01

    Congenital adrenal insufficiency is caused by specific genetic mutations. Early suspicion and definite diagnosis are crucial because the disease can precipitate a life-threatening hypovolemic shock without prompt treatment. This study was designed to understand the clinical manifestations including growth patterns and to find the usefulness of ACTH stimulation test. Sixteen patients with confirmed genotyping were subdivided into three groups according to the genetic study results: congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH, n=11), congenital lipoid adrenal hyperplasia (n=3) and X-linked adrenal hypoplasia congenita (n=2). Bone age advancement was prominent in patients with CAH especially after 60 months of chronologic age (n=6, 67%). They were diagnosed in older ages in group with bone age advancement (P<0.05). Comorbid conditions such as obesity, mental retardation, and central precocious puberty were also prominent in this group. In conclusion, this study showed the importance of understanding the clinical symptoms as well as genetic analysis for early diagnosis and management of congenital adrenal insufficiency. ACTH stimulation test played an important role to support the diagnosis and serum 17-hydroxyprogesterone levels were significantly elevated in all of the CAH patients. The test will be important for monitoring growth and puberty during follow up of patients with congenital adrenal insufficiency. PMID:24265530

  8. Single decoupled blasthole tests and the significance of the results to presplitting and boulder busting

    SciTech Connect

    Tariq, S.M.; Worsey, P.N.; Wilson, J.W.

    1996-12-01

    The position of a major joint in relation to a blasthole has a significant effect in presplitting. Broad research into the combined effects of firing two decoupled blastholes has been performed in the past. The effects of joints simulated between two blastholes has also been evaluated. However, no attempt has been made to investigate the splitting effects produced by firing a single decoupled blasthole. This paper presents the results of such an investigation. A series of model tests was carried out in specially prepared 12 x 9 x 6 inches concrete blocks each with a 3/8 inch blasthole, loaded with 15-grain detonating cord. To simulate a semi-infinite burden similar to field presplit conditions, the blocks were lightly constrained. Before tightening the blocks, wooden spacers approximately three inches thick were placed on one end of the block to provide a free face. Additional experiments were conducted without constraints to ascertain the resulting fracture pattern in boulder blasting mode. It was found, if the blasthole is relatively near to the free face the angle of crater is greater. It was also observed that, at a distance approximately five times the diameter of the blasthole, the cratering ceases. During these tests a recurring split appeared all the way back to the abutted end of the blocks far in excess of what is expected in presplitting. This was not anticipated. An extensive investigation was undertaken to find an application in presplitting and boulder busting for this new phenomenon. It was found that when the blasthole is placed close to the abutted end of the block, it can produce a significantly longer split than when it is placed near the middle of the block. This was also verified in tests without constraints, which illustrates its potential for application in boulder blasting.

  9. A powerful test of independent assortment that determines genome-wide significance quickly and accurately

    PubMed Central

    Stewart, W C L; Hager, V R

    2016-01-01

    In the analysis of DNA sequences on related individuals, most methods strive to incorporate as much information as possible, with little or no attention paid to the issue of statistical significance. For example, a modern workstation can easily handle the computations needed to perform a large-scale genome-wide inheritance-by-descent (IBD) scan, but accurate assessment of the significance of that scan is often hindered by inaccurate approximations and computationally intensive simulation. To address these issues, we developed gLOD—a test of co-segregation that, for large samples, models chromosome-specific IBD statistics as a collection of stationary Gaussian processes. With this simple model, the parametric bootstrap yields an accurate and rapid assessment of significance—the genome-wide corrected P-value. Furthermore, we show that (i) under the null hypothesis, the limiting distribution of the gLOD is the standard Gumbel distribution; (ii) our parametric bootstrap simulator is approximately 40 000 times faster than gene-dropping methods, and it is more powerful than methods that approximate the adjusted P-value; and, (iii) the gLOD has the same statistical power as the widely used maximum Kong and Cox LOD. Thus, our approach gives researchers the ability to determine quickly and accurately the significance of most large-scale IBD scans, which may contain multiple traits, thousands of families and tens of thousands of DNA sequences. PMID:27245422

  10. Hypersensitivity testing for Aspergillus fumigatus IgE is significantly more sensitive than testing for Aspergillus niger IgE.

    PubMed

    Selvaggi, Thomas A; Walco, Jeremy P; Parikh, Sujal; Walco, Gary A

    2012-02-01

    We sought to determine if sufficient redundancy exists between specific IgE testing for Aspergillus fumigatus and Aspergillus niger to eliminate one of the assays in determining Aspergillus hypersensitivity. We reviewed regional laboratory results comparing A fumigatus-specific IgE with A niger-specific IgE using the Pharmacia UniCAP system (Pharmacia, Kalamazoo, MI). By using the Fisher exact test as an index of concordance among paired results, we showed a significant difference between 109 paired samples for the presence of specific IgE to A fumigatus and A niger (P < .0001). Of these specimens, 94 were negative for IgE to both species, 10 were positive for A fumigatus and negative for A niger; no specimen was positive for A niger and negative for A fumigatus. We conclude that A fumigatus-specific IgE is sufficient to detect Aspergillus hypersensitivity. The assay for A niger-specific IgE is redundant, less sensitive, and unnecessary if the assay for specific IgE for A fumigatus is performed.

  11. Technical note: A significance test for data-sparse zones in scatter plots

    NASA Astrophysics Data System (ADS)

    Vetrova, V. V.; Bardsley, W. E.

    2012-04-01

    Data-sparse zones in scatter plots of hydrological variables can be of interest in various contexts. For example, a well-defined data-sparse zone may indicate inhibition of one variable by another. It is of interest therefore to determine whether data-sparse regions in scatter plots are of sufficient extent to be beyond random chance. We consider the specific situation of data-sparse regions defined by a linear internal boundary within a scatter plot defined over a rectangular region. An Excel VBA macro is provided for carrying out a randomisation-based significance test of the data-sparse region, taking into account both the within-region number of data points and the extent of the region. Example applications are given with respect to a rainfall time series from Israel and also to validation scatter plots from a seasonal forecasting model for lake inflows in New Zealand.

  12. Technical Note: A significance test for data-sparse zones in scatter plots

    NASA Astrophysics Data System (ADS)

    Vetrova, V. V.; Bardsley, W. E.

    2012-01-01

    Data-sparse zones in scatter plots of hydrological variables can be of interest in various contexts. For example, a well-defined data-sparse zone may indicate inhibition of one variable by another. It is of interest therefore to determine whether data-sparse regions in scatter plots are of sufficient extent to be beyond random chance. We consider the specific situation of data-sparse regions defined by a linear internal boundary within a scatter plot defined over a rectangular region. An Excel VBA macro is provided for carrying out a randomisation-based significance test of the data-sparse region, taking into account both the within-region number of data points and the extent of the region. Example applications are given with respect to a rainfall time series from Israel and to validation scatter plots from a seasonal forecasting model for lake inflows in New Zealand.

  13. A Significance Test for Inferring Affiliation Networks from Spatio-Temporal Data

    PubMed Central

    Furmston, Thomas; Morton, A. Jennifer; Hailes, Stephen

    2015-01-01

    Scientists have long been interested in studying social structures within groups of gregarious animals. However, obtaining evidence about interactions between members of a group is difficult. Recent technologies, such as Global Positioning System technology, have made it possible to obtain a vast wealth of animal movement data, but inferring the underlying (latent) social structure of the group from such data remains an important open problem. While intuitively appealing measures of social interaction exist in the literature, they typically lack formal statistical grounding. In this article, we provide a statistical approach to the problem of inferring the social structure of a group from the movement patterns of its members. By constructing an appropriate null model, we are able to construct a significance test to detect meaningful affiliations between members of the group. We demonstrate our method on large-scale real-world data sets of positional data of flocks of Merino sheep, Ovis aries. PMID:26192280

  14. The null hypothesis significance test in health sciences research (1995-2006): statistical analysis and interpretation

    PubMed Central

    2010-01-01

    Background The null hypothesis significance test (NHST) is the most frequently used statistical method, although its inferential validity has been widely criticized since its introduction. In 1988, the International Committee of Medical Journal Editors (ICMJE) warned against sole reliance on NHST to substantiate study conclusions and suggested supplementary use of confidence intervals (CI). Our objective was to evaluate the extent and quality in the use of NHST and CI, both in English and Spanish language biomedical publications between 1995 and 2006, taking into account the International Committee of Medical Journal Editors recommendations, with particular focus on the accuracy of the interpretation of statistical significance and the validity of conclusions. Methods Original articles published in three English and three Spanish biomedical journals in three fields (General Medicine, Clinical Specialties and Epidemiology - Public Health) were considered for this study. Papers published in 1995-1996, 2000-2001, and 2005-2006 were selected through a systematic sampling method. After excluding the purely descriptive and theoretical articles, analytic studies were evaluated for their use of NHST with P-values and/or CI for interpretation of statistical "significance" and "relevance" in study conclusions. Results Among 1,043 original papers, 874 were selected for detailed review. The exclusive use of P-values was less frequent in English language publications as well as in Public Health journals; overall such use decreased from 41% in 1995-1996 to 21% in 2005-2006. While the use of CI increased over time, the "significance fallacy" (to equate statistical and substantive significance) appeared very often, mainly in journals devoted to clinical specialties (81%). In papers originally written in English and Spanish, 15% and 10%, respectively, mentioned statistical significance in their conclusions. Conclusions Overall, results of our review show some improvements in

  15. Significance of fully automated tests for the diagnosis of antiphospholipid syndrome.

    PubMed

    Oku, Kenji; Amengual, Olga; Kato, Masaru; Bohgaki, Toshiyuki; Horita, Tetsuya; Yasuda, Shinsuke; Sakamoto, Naoya; Ieko, Masahiro; Norman, Gary L; Atsumi, Tatsuya

    2016-10-01

    Antiphospholipid antibodies (aPLs) can vary both immunologically and functionally, thus it is important to effectively and correctly identify their presence when diagnosing antiphospholipid syndrome. Furthermore, since many immunological/functional tests are necessary to measure aPLs, complete examinations are often not performed in many cases due to significant burden on the testing departments. To address this issue, we measured aPLs defined according to the classification criteria (anticardiolipin antibody: aCL) IgG/IgM and anti-β2 glycoprotein I antibody (aβ2GPI) (IgG/IgM) as well as non-criteria antibodies (aCL IgA, aβ2GPI IgA and aβ2GPI domain I), in a cohort of 211 patients (61 APS, 140 disease controls and 10 healthy individuals). APLs were measured using a fully automated chemiluminescent immunoassay instrument (BIO-FLASH®/ACL AcuStar®) and with conventional ELISA tests. We demonstrated that both sensitivity and accuracy of diagnosis of aCL IgG and aβ2GPI IgG were high, in agreement with the past reports. When multiple aPLs were examined, the accuracy of diagnosis increased. The proportion of APS patients that were positive for 2 or more types of aPLs (47/61, 77%) was higher than that of patients with systemic lupus erythematosus (SLE)(3/37, 9%), those with non-SLE connective tissues diseases (1/53,2%), those with other diseases or healthy volunteers. Based on these findings, it was concluded that the fully automated chemiluminescent immunoassay instrument, which allows the simultaneous evaluation of many types of aPLs, offers clear advantages for a more complete, more rapid and less labor-intensive alternative to running multiple ELISA and could help in better diagnosis for suspected APS patients.

  16. Variants of Uncertain Significance in BRCA Testing: Evaluation of Surgical Decisions, Risk Perception, and Cancer Distress

    PubMed Central

    Culver, J.O.; Brinkerhoff, C.D.; Clague, J.; Yang, K.; Singh, K.E.; Sand, S.R.; Weitzel, J.N.

    2013-01-01

    Studies suggest that patients carrying a BRCA variant of uncertain significance (VUS) may have lingering confusion concerning results interpretation. Counseling for uninformative BRCA-negative (UN) results is thought to be more straightforward, despite the fact that both results lead to similar methods of empiric cancer risk counseling. This study compared surgical choices and perceptions between 71 patients with VUS results and 714 patients with UN results. All patients underwent genetic counseling because of a personal or family history of breast or ovarian cancer between 1997 and 2010, and completed a two-year follow-up survey. Risk-reducing mastectomy rates in both groups were 7% (p=1.00) and risk-reducing oophorectomy rates were 5% and 3%, respectively (p=0.42). The VUS group reported less cancer distress reduction than the UN group (23.0% versus 35.8%, respectively, p=.043). Over 90% of both groups found the counseling process helpful. Overall, the study suggests that VUS results disclosed in genetic counseling did not cause excessive surgery or exaggerated cancer distress, though patients with a VUS found counseling somewhat less informative or reassuring. Future research on communication of VUS results, including pre-and post-test counseling, is essential for full realization of the potential for genomic medicine. PMID:23323793

  17. Significant effects of mild endogenous hormonal changes in humans: considerations for low-dose testing.

    PubMed

    Brucker-Davis, F; Thayer, K; Colborn, T

    2001-03-01

    We review the significant and adverse health effects that can occur with relatively small endogenous hormonal changes in pubertal and adult humans. We discuss the effects of hormonal changes that occur within normal physiologic ranges--such as the rising levels of estrogen in peripuberty, which cause growth spurts at low levels and then the fusion of epiphyses at higher levels--and the hormonal variations during the menstrual cycle and their relation to genital phenotypic changes and intercurrent disease evolution. We turn next to adaptive changes in gonadal and other functions during aging, exercise, stress, starvation, and chronic diseases, which can serve as models for the effects of exogenous, hormonally active compounds. Then we review the states of borderline hormonal imbalances such as subclinical (having few or very mild symptoms, if any) hypothyroidism or hyperthyroidism, glucose intolerance, and other endocrine conditions. Finally, we review the deleterious systemic effects of gonadal imbalance. Information stemming from clinical observations leads to the concept of "no threshold" within the endocrine system and thus illustrates the importance of considering low-dose testing for chemicals that interfere with hormonal activity. We also urge attention to more sensitive, less visible end points such as osteoporosis, increased risk for cardiovascular disease, or cognitive changes.

  18. Significant Predictors of Test Anxiety among Students with and without Learning Disabilities

    ERIC Educational Resources Information Center

    Whitaker Sena, Jolyn D.; Lowe, Patricia A.; Lee, Steven W. Whitaker Sena, Jolyn D.; Lowe, Patricia A.; Lee, Steven W.

    2007-01-01

    In the present study, the relationship between students with and without learning disabilities (LD) and different aspects of test anxiety was examined on a new multidimensional measure of test anxiety. A sample of 774 elementary and secondary school students--195 students with LD and 579 students not identified with LD--completed the "Test Anxiety…

  19. Everyday cognitive functioning in cardiac patients: relationships between self-report, report of a significant other and cognitive test performance.

    PubMed

    Elliott, Peter C; Smith, Geoff; Ernest, Christine S; Murphy, Barbara M; Worcester, Marian U C; Higgins, Rosemary O; Le Grande, Michael R; Goble, Alan J; Andrewes, David; Tatoulis, James

    2010-01-01

    Candidates for cardiac bypass surgery often experience cognitive decline. Such decline is likely to affect their everyday cognitive functioning. The aim of the present study was to compare cardiac patients' ratings of their everyday cognitive functioning against significant others' ratings and selected neuropsychological tests. Sixty-nine patients completed a battery of standardised cognitive tests. Patients and significant others also completed the Everyday Function Questionnaire independently of each other. Patient and significant other ratings of patients' everyday cognitive difficulties were found to be similar. Despite the similarities in ratings of difficulties, some everyday cognitive tasks were attributed to different processes. Patients' and significant others' ratings were most closely associated with the neuropsychological test of visual memory. Tests of the patients' verbal memory and fluency were only related to significant others' ratings. Test scores of attention and planning were largely unrelated to ratings by either patients or their significant others.

  20. An on-line exact small-sample test of significance for extended matching tasks.

    PubMed

    Gillett, R

    2001-11-01

    An extension of the traditional matching paradigm that enables researchers to test a variety of new experimental hypotheses is outlined. An on-line computer program that provides an exact small-sample test of hypotheses in the extended matching paradigm is described. The program, which has an intuitive graphical interface, may be accessed and executed via the Internet by using an ordinary browser.

  1. Do School-Based Tutoring Programs Significantly Improve Student Performance on Standardized Tests?

    ERIC Educational Resources Information Center

    Rothman, Terri; Henderson, Mary

    2011-01-01

    This study used a pre-post, nonequivalent control group design to examine the impact of an in-district, after-school tutoring program on eighth grade students' standardized test scores in language arts and mathematics. Students who had scored in the near-passing range on either the language arts or mathematics aspect of a standardized test at the…

  2. A simple and effective decision rule for choosing a significance test to protect against non-normality.

    PubMed

    Zimmerman, Donald W

    2011-11-01

    There is no formal and generally accepted procedure for choosing an appropriate significance test for sample data when the assumption of normality is doubtful. Various tests of normality that have been proposed over the years have been found to have limited usefulness, and sometimes a preliminary test makes the situation worse. The present paper investigates a specific and easily applied rule for choosing between a parametric and non-parametric test, the Student t test and the Wilcoxon-Mann-Whitney test, that does not require a preliminary significance test of normality. Simulations reveal that the rule, which can be applied to sample data automatically by computer software, protects the Type I error rate and increases power for various sample sizes, significance levels, and non-normal distribution shapes. Limitations of the procedure in the case of heterogeneity of variance are discussed.

  3. Avoidance tests with earthworms and springtails: defining the minimum exposure time to observe a significant response.

    PubMed

    Natal-da-Luz, Tiago; Amorim, Mónica J B; Römbke, Jörg; Sousa, José Paulo

    2008-10-01

    Based on the ability of organisms to avoid contaminated soils, avoidance tests have a great potential as early screening tools in lower tier levels of ERA schemes. Aiming at their standardization, the definition of the minimum exposure time necessary to observe an avoidance response to a contaminant is needed. To fill this gap, avoidance tests with earthworms (Eisenia andrei) and springtails (Folsomia candida), comparing distinct time periods (from 1-7 to 1-14 days, respectively), were performed using the artificial OECD soil and reference chemicals for each test organism. Results showed that for both organisms a clear response within 24 h of exposure can be obtained. This rapid response enhances the utility of the test for "on site" analysis to evaluate contaminated sites.

  4. Significance of a Positive Toxoplasma Immunoglobulin M Test Result in the United States

    PubMed Central

    Gajurel, Kiran; Pomares, Christelle; Talucod, Jeanne; Press, Cynthia J.

    2015-01-01

    A positive Toxoplasma immunoglobulin M (IgM) result is often interpreted as a marker of an acute infection. However, IgM can persist for several years, and Toxoplasma commercial IgM diagnostic test kits can yield a number of false-positive results. For these reasons, a chronic Toxoplasma infection can be erroneously classified as an acute infection, resulting in serious adverse consequences, especially in pregnant women, leading to emotional distress and unnecessary interventions, including termination of pregnancy. Interpretation of Toxoplasma serology at a reference laboratory can help differentiate a recently acquired infection from a chronic infection. Serological test results for 451 patients with positive Toxoplasma IgM and IgG test results obtained at nonreference laboratories (NRLs) that were referred to Palo Alto Medical Foundation Toxoplasma Serology Laboratory (PAMF-TSL) to determine whether the patient was acutely or chronically infected were retrospectively reviewed. PAMF-TSL results established that of the 451 patients, 335 (74%) had a chronic infection, 100 (22%) had an acute infection, and 7 (2%) were not infected, and for 9 (2%), results were indeterminate. Positive Toxoplasma IgM and IgG test results obtained at NRLs cannot accurately distinguish between acute and chronic infections. To do so, testing at reference laboratories is required, as mandated in 1997 in a letter from the Food and Drug Administration (FDA) to clinicians and laboratories in the United States. PMID:26354818

  5. Significance of a Positive Toxoplasma Immunoglobulin M Test Result in the United States.

    PubMed

    Dhakal, Reshika; Gajurel, Kiran; Pomares, Christelle; Talucod, Jeanne; Press, Cynthia J; Montoya, Jose G

    2015-11-01

    A positive Toxoplasma immunoglobulin M (IgM) result is often interpreted as a marker of an acute infection. However, IgM can persist for several years, and Toxoplasma commercial IgM diagnostic test kits can yield a number of false-positive results. For these reasons, a chronic Toxoplasma infection can be erroneously classified as an acute infection, resulting in serious adverse consequences, especially in pregnant women, leading to emotional distress and unnecessary interventions, including termination of pregnancy. Interpretation of Toxoplasma serology at a reference laboratory can help differentiate a recently acquired infection from a chronic infection. Serological test results for 451 patients with positive Toxoplasma IgM and IgG test results obtained at nonreference laboratories (NRLs) that were referred to Palo Alto Medical Foundation Toxoplasma Serology Laboratory (PAMF-TSL) to determine whether the patient was acutely or chronically infected were retrospectively reviewed. PAMF-TSL results established that of the 451 patients, 335 (74%) had a chronic infection, 100 (22%) had an acute infection, and 7 (2%) were not infected, and for 9 (2%), results were indeterminate. Positive Toxoplasma IgM and IgG test results obtained at NRLs cannot accurately distinguish between acute and chronic infections. To do so, testing at reference laboratories is required, as mandated in 1997 in a letter from the Food and Drug Administration (FDA) to clinicians and laboratories in the United States.

  6. Standardization of disk diffusion test and its clinical significance for susceptibility testing of metronidazole against Helicobacter pylori.

    PubMed Central

    Xia, H; Keane, C T; Beattie, S; O'Morain, C A

    1994-01-01

    Susceptibilities of 121 clinical Helicobacter pylori strains to metronidazole were determined by both a 5-micrograms metronidazole disk diffusion test and a plate dilution method in duplicate and after different periods of incubation. The distribution of MICs of metronidazole against H. pylori among the strains was found to be bimodal. The diameters of inhibitory zones obtained by the disk diffusion test and the MICs obtained by the plate dilution method correlated well, especially after 4 days of incubation (r = 0.77). An inhibitory zone diameter of 20 mm was found to correspond to a MIC of 8 micrograms/ml and is recommended as a suitable zone for differentiating susceptibility and resistance with a 5-micrograms metronidazole disk. Three interpretive categories of susceptibility results were defined; strains with inhibitory zone diameters of more than 26 mm were defined as susceptible (MIC, < 4 micrograms/ml), strains with zone diameters of 20 to 26 mm were deemed intermediate (MIC, 4 to 8 micrograms/ml), and those with zone diameters of less than 20 mm were deemed resistant (MIC, > 8 micrograms/ml). Furthermore, 76 H. pylori-positive patients with duodenal ulcers or nonulcer dyspepsia were treated with a 1 week of triple therapy (colloidal bismuth subcitrate, metronidazole, and tetracycline). H. pylori strains were isolated before treatment from antral biopsies from those patients, and the metronidazole susceptibilities of the strains were determined by the disk diffusion test. H. pylori status was evaluated again 4 weeks after completion of treatment. The eradication rates for susceptible, intermediate, and resistant strains were 95.9% (47 of 49), 62.5% (5 of 8), and 52.6% (10 of 19), respectively. It is included that the 5-micrograms disk diffusion test is easy to perform and gives final results similar to those of the plate dilution method. The three interpretive categories of susceptibility may be of benefit for clinical choice of chemotherapy in eradicating

  7. Analysis of residuals in contingency tables: another nail in the coffin of conditional approaches to significance testing.

    PubMed

    García-Pérez, Miguel A; Núñez-Antón, Vicente; Alcalá-Quintana, Rocío

    2015-03-01

    Omnibus tests of significance in contingency tables use statistics of the chi-square type. When the null is rejected, residual analyses are conducted to identify cells in which observed frequencies differ significantly from expected frequencies. Residual analyses are thus conditioned on a significant omnibus test. Conditional approaches have been shown to substantially alter type I error rates in cases involving t tests conditional on the results of a test of equality of variances, or tests of regression coefficients conditional on the results of tests of heteroscedasticity. We show that residual analyses conditional on a significant omnibus test are also affected by this problem, yielding type I error rates that can be up to 6 times larger than nominal rates, depending on the size of the table and the form of the marginal distributions. We explored several unconditional approaches in search for a method that maintains the nominal type I error rate and found out that a bootstrap correction for multiple testing achieved this goal. The validity of this approach is documented for two-way contingency tables in the contexts of tests of independence, tests of homogeneity, and fitting psychometric functions. Computer code in MATLAB and R to conduct these analyses is provided as Supplementary Material.

  8. Cocamidopropyl betaine: the significance of positive patch test results in twelve patients.

    PubMed

    Fowler, J F

    1993-11-01

    Cocamidopropyl betaine is a surfactant coming into wide use in shampoos and other cleansing products. Recent reports have implicated it as a potential allergen, although it is less irritating than other surfactants such as sodium lauryl sulfate. Twelve positive patch test results were seen over a period of fifteen months of testing in selected patients. Of these, seven results were thought to be relevant. All seven patients with relevant reactions and four of the five with uncertain relevance had dermatitis of the head and neck area. It is concluded that although cocamidopropyl betaine is not a common allergen, it may be at least partially responsible for some cases of allergic dermatitis of the head and neck.

  9. Analysis of pumping tests: Significance of well diameter, partial penetration, and noise

    USGS Publications Warehouse

    Heidari, M.; Ghiassi, K.; Mehnert, E.

    1999-01-01

    The nonlinear least squares (NLS) method was applied to pumping and recovery aquifer test data in confined and unconfined aquifers with finite diameter and partially penetrating pumping wells, and with partially penetrating piezometers or observation wells. It was demonstrated that noiseless and moderately noisy drawdown data from observation points located less than two saturated thicknesses of the aquifer from the pumping well produced an exact or acceptable set of parameters when the diameter of the pumping well was included in the analysis. The accuracy of the estimated parameters, particularly that of specific storage, decreased with increases in the noise level in the observed drawdown data. With consideration of the well radii, the noiseless drawdown data from the pumping well in an unconfined aquifer produced good estimates of horizontal and vertical hydraulic conductivities and specific yield, but the estimated specific storage was unacceptable. When noisy data from the pumping well were used, an acceptable set of parameters was not obtained. Further experiments with noisy drawdown data in an unconfined aquifer revealed that when the well diameter was included in the analysis, hydraulic conductivity, specific yield and vertical hydraulic conductivity may be estimated rather effectively from piezometers located over a range of distances from the pumping well. Estimation of specific storage became less reliable for piezemeters located at distances greater than the initial saturated thickness of the aquifer. Application of the NLS to field pumping and recovery data from a confined aquifer showed that the estimated parameters from the two tests were in good agreement only when the well diameter was included in the analysis. Without consideration of well radii, the estimated values of hydraulic conductivity from the pumping and recovery tests were off by a factor of four.The nonlinear least squares method was applied to pumping and recovery aquifer test data in

  10. 77 FR 30972 - Certain Polybrominated Diphenylethers; Significant New Use Rule and Test Rule; Extension of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-24

    ...EPA issued a proposed rule in the Federal Register of April 2, 2012, that would amend the Toxic Substances Control Act (TSCA) section 5(a) Significant New Use Rule (SNUR) for certain polybrominated diphenylethers (PBDEs), and that would require persons that manufacture, import, or process any of three commercial PBDEs, including in articles, for any use after December 31, 2013, to conduct......

  11. Adjusting a Significance Test for Clustering in Designs with Two Levels of Nesting

    ERIC Educational Resources Information Center

    Hedges, Larry V.

    2009-01-01

    A common mistake in analysis of cluster randomized experiments is to ignore the effect of clustering and analyze the data as if each treatment group were a simple random sample. This typically leads to an overstatement of the precision of results and anticonservative conclusions about precision and statistical significance of treatment effects.…

  12. Strategies for Testing Statistical and Practical Significance in Detecting DIF with Logistic Regression Models

    ERIC Educational Resources Information Center

    Fidalgo, Angel M.; Alavi, Seyed Mohammad; Amirian, Seyed Mohammad Reza

    2014-01-01

    This study examines three controversial aspects in differential item functioning (DIF) detection by logistic regression (LR) models: first, the relative effectiveness of different analytical strategies for detecting DIF; second, the suitability of the Wald statistic for determining the statistical significance of the parameters of interest; and…

  13. Cryptococcal antigen test revisited: significance for cryptococcal meningitis therapy monitoring in a tertiary chinese hospital.

    PubMed

    Lu, Hongzhou; Zhou, Yingjie; Yin, Youkuan; Pan, Xiaozhang; Weng, Xinhua

    2005-06-01

    For a total of 29 non-human immunodeficiency virus 1 cryptococcal meningitis cases, titer changes in the latex agglutination test before and after therapy were reviewed along with clinical manifestations, laboratory findings, and therapy regimens. The cryptococcal antigen titer decreased for every case after therapy and was correlated to fungal clearance as defined by fungus smear and/or culture. However, cryptococcal antigen can remain at low titers for long periods of time after therapy, even when fungus smears and/or cultures become negative.

  14. Patch testing with budesonide in serial dilutions: the significance of dose, occlusion time and reading time.

    PubMed

    Isaksson, M; Bruze, M; Goossens, A; Lepoittevin, J P

    1999-01-01

    Budesonide is advocated as a marker molecule for corticosteroid contact allergy. When patch testing corticosteroids, one must consider their sensitizing potential but also their anti-inflammatory properties, as well as the possibility of different time courses for such properties. The dose-response relationship for budesonide was therefore investigated with regard to dose, occlusion time, and reading time. 10 patients were patch tested with budesonide in ethanol in serial dilutions from 2.0% down to 0.0002% with occlusion times of 48, 24, and 5 h. Readings were on D2, D4, and D7. The 48-h occlusion picked up most positive reactors, 8/10. The D4 reading (48-h occlusion) detected most positive reactors, 8/10, and here 0.002% picked up most contact allergies. Late readings favoured high concentrations. The "edge effect" was noted for several concentrations at early readings. Due to the individual corticosteroid reactivity, the dose-response relationship and the time courses of the elicitation and the anti-inflammatory capacity, several features may be explained, i.e., that lower concentrations may detect budesonide allergy better at early readings, that patients with an "edge reaction" can have positive reactions to lower concentrations.

  15. Combination antimicrobial susceptibility testing of Burkholderia cepacia complex: significance of species.

    PubMed

    Abbott, Felicity K; Milne, Kathleen E N; Stead, David A; Gould, Ian M

    2016-11-01

    The Burkholderia cepacia complex (Bcc) is notorious for the life-threatening pulmonary infections it causes in patients with cystic fibrosis. The multidrug-resistant nature of Bcc and differing infective Bcc species make the design of appropriate treatment regimens challenging. Previous synergy studies have failed to take account of the species of Bcc isolates. Etest methodology was used to facilitate minimum inhibitory concentration (MIC) and antimicrobial combination testing on 258 isolates of Bcc, identified to species level by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). The most active antimicrobials were trimethoprim/sulphamethoxazole, doxycycline and minocycline (52.5%, 46.4% and 45.9% of isolates susceptible, respectively). Synergy was observed in 9.2% of the 1799 combinations tested; the most common synergistic combinations were tobramycin + ceftazidime, meropenem + tobramycin and levofloxacin + piperacillin/tazobactam (35.4%, 32.3% and 22.2% synergy, respectively). Antimicrobial susceptibility analysis revealed differences between Burkholderia cenocepacia and Burkholderia multivorans. Disparity in clinical outcome during infection with these two micro-organisms necessitates further investigation into the clinical outcomes of treatment regimens in light of species identification and in vitro antimicrobial susceptibility studies.

  16. On the Relationship between the Johnson-Neyman Region of Significance and Statistical Tests of Parallel Within-Group Regressions.

    ERIC Educational Resources Information Center

    Rogosa, David

    1981-01-01

    The form of the Johnson-Neyman region of significance is shown to be determined by the statistic for testing the null hypothesis that the population within-group regressions are parallel. Results are obtained for both simultaneous and nonsimultaneous regions of significance. (Author)

  17. Testing reanalysis data sets in Antarctica: Trends, persistence properties, and trend significance

    NASA Astrophysics Data System (ADS)

    Wang, Yang; Zhou, Dong; Bunde, Armin; Havlin, Shlomo

    2016-11-01

    The reanalysis data sets provide important sources for investigating the climate in Antarctica where stations are sparse. In this paper, we compare the 2 m near-surface temperature data from five major reanalysis data sets with observational Antarctic stations data over the last 36 years: (i) the National Centers for Environmental Prediction and the National Center for Atmospheric Research Reanalysis (NCEP1), (ii) NCEP-DOE Reanalysis 2 (NCEP2), (iii) the European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA-Interim), (iv) the Japanese 55 year Reanalysis (JRA-55), and (v) the National Aeronautics and Space Administration Modern-Era Retrospective-analysis for Research and Applications. In our assessment, we compare (a) the annual and seasonal trends obtained by linear regression analysis, (b) the standard deviation around the annual trends, (c) the detrended lag-1-autocorrelation C(1), (d) the Hurst exponent α that characterizes the long-term memory in a record, and (e) the significance levels of the warming/cooling trends. We find that all five reanalysis data sets are able to reproduce quite well the long-term memory in the instrumental data. In contrast, C(1), which is needed as input for the conventional significance analysis, shows fully erratic behavior. The observational warming/cooling trends in East and West Antarctica are not reproduced well by all reanalysis data sets, in particular, NCEP1, NCEP2, and JRA-55 show spurious warming trends in many parts of East Antarctica, even in those parts where cooling has been observed. In contrast, the standard deviation around the trends is quite well reproduced by all reanalysis data sets. In the peninsula where the station density is quite high, the performance of the reanalysis data is considerably better. It is remarkable that all reanalysis data sets as well as the observational data show (under the assumption of a long-term persistent process) that in the considered time period since 1979

  18. A procedure for testing the significance of orbital tuning of the martian polar layered deposits

    NASA Astrophysics Data System (ADS)

    Sori, Michael M.; Perron, J. Taylor; Huybers, Peter; Aharonson, Oded

    2014-06-01

    Layered deposits of dusty ice in the martian polar caps have been hypothesized to record climate changes driven by orbitally induced variations in the distribution of incoming solar radiation. Attempts to identify such an orbital signal by tuning a stratigraphic sequence of polar layered deposits (PLDs) to match an assumed forcing introduce a risk of identifying spurious matches between unrelated records. We present an approach for evaluating the significance of matches obtained by orbital tuning, and investigate the utility of this approach for identifying orbital signals in the Mars PLDs. Using a set of simple models for ice and dust accumulation driven by insolation, we generate synthetic PLD stratigraphic sequences with nonlinear time-depth relationships. We then use a dynamic time warping algorithm to attempt to identify an orbital signal in the modeled sequences, and apply a Monte Carlo procedure to determine whether this match is significantly better than a match to a random sequence that contains no orbital signal. For simple deposition mechanisms in which dust deposition rate is constant and ice deposition rate varies linearly with insolation, we find that an orbital signal can be confidently identified if at least 10% of the accumulation time interval is preserved as strata. Addition of noise to our models raises this minimum preservation requirement, and we expect that more complex deposition functions would generally also make identification more difficult. In light of these results, we consider the prospects for identifying an orbital signal in the actual PLD stratigraphy, and conclude that this is feasible even with a strongly nonlinear relationship between stratigraphic depth and time, provided that a sufficient fraction of time is preserved in the record and that ice and dust deposition rates vary predictably with insolation. Independent age constraints from other techniques may be necessary, for example, if an insufficient amount of time is

  19. Bootstrap tests of significance and the case for humanlike skeletal-size dimorphism in Australopithecus afarensis.

    PubMed

    Scott, Jeremiah E; Stroik, Laura K

    2006-10-01

    Most estimates of sexual size dimorphism in Australopithecus afarensis indicate that this early hominin was more dimorphic than modern humans. In contrast, a recent study reported that size variation in A. afarensis, as represented by postcranial remains from Hadar and Maka, Ethiopia, is statistically most similar to that of modern humans, indicating a humanlike level of sexual dimorphism. Here, we evaluate the evidence for humanlike dimorphism in A. afarensis. We argue that statistical support for this claim is not as robust as has been asserted for the following reasons: (1) the analysis from which the claim was derived does not distinguish the A. afarensis sample from either the human or chimpanzee samples; (2) for some of the comparisons made, the A. afarensis sample cannot be distinguished from the Gorilla sample using two-tailed tests; and (3) the A. afarensis postcranial sample used in the analysis may contain more male than female specimens, which precludes a straightforward interpretation of the statistical results. Thus, support for humanlike dimorphism is equivocal, and a greater level of dimorphism cannot be ruled out.

  20. Significance of HbA1c Test in Diagnosis and Prognosis of Diabetic Patients

    PubMed Central

    Sherwani, Shariq I.; Khan, Haseeb A.; Ekhzaimy, Aishah; Masood, Afshan; Sakharkar, Meena K.

    2016-01-01

    Diabetes is a global endemic with rapidly increasing prevalence in both developing and developed countries. The American Diabetes Association has recommended glycated hemoglobin (HbA1c) as a possible substitute to fasting blood glucose for diagnosis of diabetes. HbA1c is an important indicator of long-term glycemic control with the ability to reflect the cumulative glycemic history of the preceding two to three months. HbA1c not only provides a reliable measure of chronic hyperglycemia but also correlates well with the risk of long-term diabetes complications. Elevated HbA1c has also been regarded as an independent risk factor for coronary heart disease and stroke in subjects with or without diabetes. The valuable information provided by a single HbA1c test has rendered it as a reliable biomarker for the diagnosis and prognosis of diabetes. This review highlights the role of HbA1c in diagnosis and prognosis of diabetes patients. PMID:27398023

  1. [Physiological significance and interpretation of plasma lactate concentration and pH in clinical exercise testing].

    PubMed

    Péronnet, F; Aguilaniu, B

    2014-06-01

    According to a widely accepted model, based on the theory of the anaerobic threshold (AT), the increase in plasma lactate concentration which develops after the first ventilatory threshold (VT1, considered as an AT) is due to compensation for insufficient aerobic metabolism by anaerobic glycolysis, with accumulation of lactic acid resulting in a decrease in pH. Bicarbonate is the main buffer of protons (>90%) producing non-metabolic CO2 in muscle and thus increasing the CO2 flux to the lungs. This phenomenon, along with the low pH, triggers hyperventilation. Because of this model, great importance has been placed on plasma lactate and pH. We argue that this importance is excessive and these variables should be used with caution in the interpretation of clinical exercise testing, because the model based on AT is not valid: there is no aerobic failure above VT1 and, thus, there is no evidence of an AT; the increase in plasma lactate does not reflect anaerobiosis but is the marker of the increase in the error signal needed for the stimulation of mitochondrial respiration; bicarbonate is not the main buffer during exercise (these are proteins and phosphocreatine breakdown in the muscle; hemoglobin in the blood); non-metabolic CO2 is not produced in the muscle but in the lung because of the low pH and hyperventilation (the control of which remains unknown); and the flux of CO2 to the lung does not increase at faster rate after than before VT1.

  2. Evolutionary significance of phenotypic accommodation in novel environments: an empirical test of the Baldwin effect

    PubMed Central

    Badyaev, Alexander V.

    2009-01-01

    When faced with changing environments, organisms rapidly mount physiological and behavioural responses, accommodating new environmental inputs in their functioning. The ubiquity of this process contrasts with our ignorance of its evolutionary significance: whereas within-generation accommodation of novel external inputs has clear fitness consequences, current evolutionary theory cannot easily link functional importance and inheritance of novel accommodations. One hundred and twelve years ago, J. M. Baldwin, H. F. Osborn and C. L. Morgan proposed a process (later termed the Baldwin effect) by which non-heritable developmental accommodation of novel inputs, which makes an organism fit in its current environment, can become internalized in a lineage and affect the course of evolution. The defining features of this process are initial overproduction of random (with respect to fitness) developmental variation, followed by within-generation accommodation of a subset of this variation by developmental or functional systems (‘organic selection’), ensuring the organism's fit and survival. Subsequent natural selection sorts among resultant developmental variants, which, if recurrent and consistently favoured, can be inherited when existing genetic variance includes developmental components of individual modifications or when the ability to accommodate novel inputs is itself heritable. Here, I show that this process is consistent with the origin of novel adaptations during colonization of North America by the house finch. The induction of developmental variation by novel environments of this species's expanding range was followed by homeostatic channelling, phenotypic accommodation and directional cross-generational transfer of a subset of induced developmental outcomes favoured by natural selection. These results emphasize three principal points. First, contemporary novel adaptations result mostly from reorganization of existing structures that shape newly expressed

  3. Significance Testing Without Truth

    DTIC Science & Technology

    2012-07-27

    following structure: Section 2 very briefly discusses Bayesian-frequentist hybrids, referring for details to the definitive work of Gelman (2003). Section 3...However, there exist Bayesian-frequentist hybrids known as “Bayesian P-values”; Gelman (2003) sets forth a particularly appealing formulation. Bayesian P...Jianqing Fan, Jiayang Gao, Andrew Gelman , Leslie Greengard, Peter W. Jones, Deborah Mayo, Peter Mc- Cullagh, Michael O’Neil, Ron Peled, William H. Press

  4. Modifications to the AOAC use-dilution test for quaternary ammonium compound-based disinfectants that significantly improve method reliability.

    PubMed

    Arlea, Crystal; King, Sharon; Bennie, Barbara; Kemp, Kere; Mertz, Erin; Staub, Richard

    2008-01-01

    The AOAC use-dilution test (UDT) for bactericidal disinfectant efficacy (Method 964.02) has often been criticized for its extreme variability in test results, particularly for quaternary ammonium compound (QAC)-based disinfectants against Pseudomonas aeruginosa. While efforts are under way to develop a new and better test method for hospital disinfectant products that is globally acceptable, U.S. manufacturers and formulators of QAC products must continue in the interim to measure their product performance against the current UDT method. Therefore, continued variability in the UDT places an unnecessary and unfair burden on U.S. QAC product manufacturers to ensure that their products perform against an, at best, unreliable test method. This article reports on evaluations that were conducted to attempt to identify key sources of UDT method variability and to find ways to mitigate their impact on test outcomes for the method. The results of testing across 4 laboratories, involving over 6015 carriers, determined that operator error was a key factor in test variability. This variability was found to be significantly minimized by the inclusion of a simple culture dilution step. The findings from this study suggest possible refinements to the current AOAC UDT method that would serve to improve the overall ruggedness and reliability of the method and to optimize recovery of cells from the carrier surface, thereby further improving the accuracy and reproducibility of counts and test outcomes until such time as a replacement method is implemented.

  5. Explanation of Significant Differences for the Record of Decision for the Test Area North Operable Unit 1-10

    SciTech Connect

    D. L. Eaton

    2007-01-18

    This Explanation of Significant Differences (ESD) applies to the remedial actions performed under the Final Record of Decision for Test Area North, Operable Unit 1-1 0, Idaho National Engineering and Environmental Laboratory (DOE-ID 1999) as amended by the Explanation of Significant Differences for the Record of Decision for the Test Area North Operable Unit 1-10 (DOE-ID 2003), the Record of Decision Amendment for the V-Tanks (TSF-09 and TSF-18) and Explanation of Significant Differences for the PM-2A Tanks (TSF-26) and TSF-06, Area IO, at Test Area North, Operable Unit 1-1 0 (DOE-ID 2004a), and the Explanation of Significant Differences for the Record of Decision for the Test Area North Operable Unit 1-10 (DOE-ID 2005). The U.S. Department of Energy (DOE) Idaho Operations Office; U.S. Environmental Protection Agency (EPA), Region 10; and the Idaho Department of Health and Welfare-now identified as the Idaho Department of Environmental Quality (DEQ)-signed the Record of Decision (ROD) in December 1999, the 2003 ESD in April 2003, the ROD Amendment/ESD in February 2004, and the 2005 ESD in January 2005. The EPA and DEQ support the need for this ESD.

  6. A New Method for Assessing the Statistical Significance in the Differential Functioning of Items and Tests (DFIT) Framework

    ERIC Educational Resources Information Center

    Oshima, T. C.; Raju, Nambury S.; Nanda, Alice O.

    2006-01-01

    A new item parameter replication method is proposed for assessing the statistical significance of the noncompensatory differential item functioning (NCDIF) index associated with the differential functioning of items and tests framework. In this new method, a cutoff score for each item is determined by obtaining a (1-alpha ) percentile rank score…

  7. Prognostic significance of cardiopulmonary exercise testing for 10-year survival in patients with mild to moderate heart failure.

    PubMed

    Koike, A; Koyama, Y; Itoh, H; Adachi, H; Marumo, F; Hiroe, M

    2000-12-01

    Although a number of studies have investigated the prognostic significance of exercise variables, they have focused only on short-term prognosis in relatively severe heart failure. This study was carried out to determine whether the indices obtained during cardiopulmonary exercise testing have prognostic significance during a 10-year follow-up in mild to moderate heart failure. Three hundred and sixty-four consecutive patients with cardiac disease performed 4 min of 20-W warm-up, followed by a symptom-limited incremental exercise test on a cycle ergometer. In addition to the measurements of peak oxygen uptake (VO2) and gas exchange (anaerobic) threshold, the time constant of VO2 kinetics during the onset of warm-up exercise was calculated using a single exponential equation. Data on mortality were available for follow-up in 260 patients. After 3,331+/-610 days of follow-up, 29 cardiovascular-related deaths occurred. The time constant of VO2 in the nonsurvivors was 76.7+/-43.3 s and was significantly prolonged compared with that of survivors (55.3+/-30.6 s, p=0.001). Peak VO2 and gas exchange threshold were both significantly lower in nonsurvivors than in survivors. Kaplan-Meier survival curves for 10 years of follow-up demonstrated a survival rate of 89.0% for patients with a normal VO2 time constant (< 80 s) and 71.7% for those with a longer time constant (> or = 80 s), showing a significant difference in survival (p=0.0028). Respiratory gas parameters obtained during exercise testing, particularly the time constant of VO2 kinetics, were found to be useful for predicting long-term prognosis in patients with chronic heart failure. These results suggest that cardiopulmonary exercise testing could be more applicable in ambulatory patients with minimal symptoms or minimal functional impairment.

  8. Testing the significance of a correlation with nonnormal data: comparison of Pearson, Spearman, transformation, and resampling approaches.

    PubMed

    Bishara, Anthony J; Hittner, James B

    2012-09-01

    It is well known that when data are nonnormally distributed, a test of the significance of Pearson's r may inflate Type I error rates and reduce power. Statistics textbooks and the simulation literature provide several alternatives to Pearson's correlation. However, the relative performance of these alternatives has been unclear. Two simulation studies were conducted to compare 12 methods, including Pearson, Spearman's rank-order, transformation, and resampling approaches. With most sample sizes (n ≥ 20), Type I and Type II error rates were minimized by transforming the data to a normal shape prior to assessing the Pearson correlation. Among transformation approaches, a general purpose rank-based inverse normal transformation (i.e., transformation to rankit scores) was most beneficial. However, when samples were both small (n ≤ 10) and extremely nonnormal, the permutation test often outperformed other alternatives, including various bootstrap tests.

  9. Functional testing strategy for coding genetic variants of unclear significance in MLH1 in Lynch syndrome diagnosis.

    PubMed

    Hinrichsen, Inga; Schäfer, Dieter; Langer, Deborah; Köger, Nicole; Wittmann, Margarethe; Aretz, Stefan; Steinke, Verena; Holzapfel, Stefanie; Trojan, Jörg; König, Rainer; Zeuzem, Stefan; Brieger, Angela; Plotz, Guido

    2015-02-01

    Lynch syndrome is caused by inactivating mutations in the MLH1 gene, but genetic variants of unclear significance frequently preclude diagnosis. Functional testing can reveal variant-conferred defects in gene or protein function. Based on functional defect frequencies and clinical applicability of test systems, we developed a functional testing strategy aimed at efficiently detecting pathogenic defects in coding MLH1 variants. In this strategy, tests of repair activity and expression are prioritized over analyses of subcellular protein localization and messenger RNA (mRNA) formation. This strategy was used for four unclear coding MLH1 variants (p.Asp41His, p.Leu507Phe, p.Gln689Arg, p.Glu605del + p.Val716Met). Expression was analyzed using a transfection system, mismatch repair (MMR) activity by complementation in vitro, mRNA formation by reverse transcriptase-PCR in carrier lymphocyte mRNA, and subcellular localization with dye-labeled fusion constructs. All tests included clinically meaningful controls. The strategy enabled efficient identification of defects in two unclear variants: the p.Asp41His variant showed loss of MMR activity, whereas the compound variant p.Glu605del + p.Val716Met had a defect of expression. This expression defect was significantly stronger than the pathogenic expression reference variant analyzed in parallel, therefore the defect of the compound variant is also pathogenic. Interestingly, the expression defect was caused additively by both of the compound variants, at least one of which is non-pathogenic when occurring by itself. Tests were neutral for p.Leu507Phe and p.Gln689Arg, and the results were consistent with available clinical data. We finally discuss the improved sensitivity and efficiency of the applied strategy and its limitations in analyzing unclear coding MLH1 variants.

  10. The effects of radioisotopes used in nuclear medicine on diagnostic radioimmunoassay testing. Is there any significant interference

    SciTech Connect

    Riccio, J.A.; Maturani, D.; Wright, J.; Fleetwood, M.K. )

    1990-11-01

    The administration of radioisotopes for diagnostic nuclear medicine scans and therapeutic procedures is quite prevalent today. A period of interference with the counting of a radioimmunoassay (RIA) test may occur with the serum of a patient receiving an in vivo radionuclide that decays by gamma emission. Because the logistics of precounting all specimens may be cumbersome and prohibitive, it is important to determine the degree of this interference. In this study, the authors evaluate the potential interference of the most commonly used radioisotopes with RIA studies. For two months (March and August 1988) 10,650 patient serum specimens were counted for significant background gamma radiation before RIA testing. Forty-three patients, on whom 105 RIA tests were performed, were identified as having preassay gamma radiation in their serum. With the use of selective energy windows for each different interfering radionuclide, proportional determinations were made as to the amount of interfering gamma radiation spilling into the iodine 125 test marker window. It was shown that initial whole serum pretest gamma counts as high as 111,000 counts/minute did not significantly affect the results of the RIA. Because of the meticulous washing and decanting procedures required in modern RIA and the monoclonal nature of most antibodies used currently, it appears the degree of nonspecific binding of this potentially interfering radiation is minuscule. The energy level of cobalt 57, however, and many of the other commonly used radioisotopes, overlaps so closely that it is difficult to window for this interference. It is possible, therefore, that this distinction cannot be made and folate and vitamin B12 test systems using cobalt 57 markers may have to be routinely prescreened.

  11. Dose-rate plays a significant role in synchrotron radiation X-ray-induced damage of rodent testes

    PubMed Central

    Chen, Heyu; Wang, Ban; Wang, Caixia; Cao, Wei; Zhang, Jie; Ma, Yingxin; Hong, Yunyi; Fu, Shen; Wu, Fan; Ying, Weihai

    2016-01-01

    Synchrotron radiation (SR) X-ray has significant potential for applications in medical imaging and cancer treatment. However, the mechanisms underlying SR X-ray-induced tissue damage remain unclear. Previous studies on regular X-ray-induced tissue damage have suggested that dose-rate could affect radiation damage. Because SR X-ray has exceedingly high dose-rate compared to regular X-ray, it remains to be determined if dose-rate may affect SR X-ray-induced tissue damage. We used rodent testes as a model to investigate the role of dose-rate in SR X-ray-induced tissue damage. One day after SR X-ray irradiation, we determined the effects of the irradiation of the same dosage at two different dose-rates, 0.11 Gy/s and 1.1 Gy/s, on TUNEL signals, caspase-3 activation and DNA double-strand breaks (DSBs) of the testes. Compared to those produced by the irradiation at 0.11 Gy/s, irradiation at 1.1 Gy/s produced higher levels of DSBs, TUNEL signals, and caspase-3 activation in the testes. Our study has provided the first evidence suggesting that dose-rate could be a significant factor in SR X-ray-induced tissue damage, which may establish a valuable base for utilizing this factor to manipulate the tissue damage in SR X-ray-based medical applications. PMID:28078052

  12. Dose-rate plays a significant role in synchrotron radiation X-ray-induced damage of rodent testes.

    PubMed

    Chen, Heyu; Wang, Ban; Wang, Caixia; Cao, Wei; Zhang, Jie; Ma, Yingxin; Hong, Yunyi; Fu, Shen; Wu, Fan; Ying, Weihai

    2016-01-01

    Synchrotron radiation (SR) X-ray has significant potential for applications in medical imaging and cancer treatment. However, the mechanisms underlying SR X-ray-induced tissue damage remain unclear. Previous studies on regular X-ray-induced tissue damage have suggested that dose-rate could affect radiation damage. Because SR X-ray has exceedingly high dose-rate compared to regular X-ray, it remains to be determined if dose-rate may affect SR X-ray-induced tissue damage. We used rodent testes as a model to investigate the role of dose-rate in SR X-ray-induced tissue damage. One day after SR X-ray irradiation, we determined the effects of the irradiation of the same dosage at two different dose-rates, 0.11 Gy/s and 1.1 Gy/s, on TUNEL signals, caspase-3 activation and DNA double-strand breaks (DSBs) of the testes. Compared to those produced by the irradiation at 0.11 Gy/s, irradiation at 1.1 Gy/s produced higher levels of DSBs, TUNEL signals, and caspase-3 activation in the testes. Our study has provided the first evidence suggesting that dose-rate could be a significant factor in SR X-ray-induced tissue damage, which may establish a valuable base for utilizing this factor to manipulate the tissue damage in SR X-ray-based medical applications.

  13. Performance of a New Rapid Immunoassay Test Kit for Point-of-Care Diagnosis of Significant Bacteriuria

    PubMed Central

    Cox, Marsha E.; DiNello, Robert K.; Geisberg, Mark; Abbott, April; Roberts, Pacita L.; Hooton, Thomas M.

    2015-01-01

    Urinary tract infections (UTIs) are frequently encountered in clinical practice and most commonly caused by Escherichia coli and other Gram-negative uropathogens. We tested RapidBac, a rapid immunoassay for bacteriuria developed by Silver Lake Research Corporation (SLRC), compared with standard bacterial culture using 966 clean-catch urine specimens submitted to a clinical microbiology laboratory in an urban academic medical center. RapidBac was performed in accordance with instructions, providing a positive or negative result in 20 min. RapidBac identified as positive 245/285 (sensitivity 86%) samples with significant bacteriuria, defined as the presence of a Gram-negative uropathogen or Staphylococcus saprophyticus at ≥103 CFU/ml. The sensitivities for Gram-negative bacteriuria at ≥104 CFU/ml and ≥105 CFU/ml were 96% and 99%, respectively. The specificity of the test, detecting the absence of significant bacteriuria, was 94%. The sensitivity and specificity of RapidBac were similar on samples from inpatient and outpatient settings, from male and female patients, and across age groups from 18 to 89 years old, although specificity was higher in men (100%) compared with that in women (92%). The RapidBac test for bacteriuria may be effective as an aid in the point-of-care diagnosis of UTIs especially in emergency and primary care settings. PMID:26063858

  14. Single-disk diffusion testing (Kirby-Bauer) of susceptibility of Proteus mirabilis to chloramphenicol: significance of the intermediate category.

    PubMed

    Furtado, G L; Medeiros, A A

    1980-10-01

    The significance of the intermediate category of the single-disk diffusion test (Kirby-Bauer) of antibiotic susceptibility has never been clearly defined. Thirty-two percent of 756 clinical isolates of Proteus mirabilis were of intermediate susceptibility to chloramphenicol, a higher percentage than for any other species. The breakpoint separating susceptible and intermediate isolates nearly bisected the frequency distribution of zone diameters of P. mirabilis but not that of the other species. The breakpoint separating susceptible and intermediate isolates nearly bisected the frequency distribution of zone diameters of P. mirabillis but not that of the other species tested. By serial broth dilution testing, the minimal inhibitory concentrations (MICs) of chloramphenicol of 50 individual isolates of P. mirabilis were 3.9 to 22.1 micrograms/ml (geometric mean, 8.0), whereas the MICs of susceptible Escherichia coli, Klebsiella, and Enterobacter strains were 2.0 to 3.9 micrograms/ml (geometric mean, 2.9). Seventy percent of isolates of P. mirabilis with MICs of 7.8 to 15.6 micrograms/ml were classified as susceptible by disk testing. We conclude that existing Kirby-Bauer breakpoints do not accurately discriminate P. mirabilis isolates that are marginally susceptible to chloramphenicol. These data underscore the difficulty of applying a single set of breakpoints to all species and suggest that species-specific breakpoints would more accurately predict the MIC equivalent of given zone diameters.

  15. Significance of serum antibody test for toxocariasis in healthy healthcare examinees with eosinophilia in Seoul and Gyeongsangnam-do, Korea.

    PubMed

    Kim, Hong Seok; Jin, Yan; Choi, Min-Ho; Kim, Jae-Hwan; Lee, Young Ha; Yoon, Cheong Ha; Hwang, Eui-Hyuk; Kang, Hun; Ahn, Sang-Yong; Kim, Gi Jin; Hong, Sung-Tae

    2014-12-01

    There have been numerous reports on the relationship between eosinophilia and toxocariasis. The present study investigated seropositive rates of toxocariasis among healthy people with or without eosinophilia in urban and rural areas, and assessed risk factors for positive antibody test. A total of 610 healthy people, who visited health check-up (Medicheck®, Korea Association of Health Promotion), 310 from Seoul and 300 from Gyeongsangnam-do, were subjected for this study. Their serum samples were tested by ELISA with the crude antigen of Toxocara canis larvae. Cross-reactions with other tissue invading helminth antigens were also investigated. Total antibody positive rate of toxocariasis was 8.7% of the 610 subjects. When the subjects were grouped into 3 by their eosinophil counts, the antibody positive rates significantly differed by the groups; 5.9% (18/306) in the group<350/µL, 10.0% (11/110) in the group 350-500/µL, and 12.4% (24/194) in the group>500/µL (P=0.028). A total of 22 serum samples cross-reacted with other tissue-invading helminth antigens. A questionnaire analysis recognized drinking alcohol and smoking as significant risk factors of toxocariasis. In conclusion, toxocariasis antibody positive rate is correlated with eosinophil counts. It is recommended that healthy subjects with eosinophilia by routine health examination and risk factors undergo Toxocara serology by multiantigen ELISA to investigate etiology.

  16. The statistical significance test of regional climate change caused by land use and land cover variation in West China

    NASA Astrophysics Data System (ADS)

    Wang, H. J.; Shi, W. L.; Chen, X. H.

    2006-05-01

    The West Development Policy being implemented in China is causing significant land use and land cover (LULC) changes in West China. With the up-to-date satellite database of the Global Land Cover Characteristics Database (GLCCD) that characterizes the lower boundary conditions, the regional climate model RIEMS-TEA is used to simulate possible impacts of the significant LULC variation. The model was run for five continuous three-month periods from 1 June to 1 September of 1993, 1994, 1995, 1996, and 1997, and the results of the five groups are examined by means of a student t-test to identify the statistical significance of regional climate variation. The main results are: (1) The regional climate is affected by the LULC variation because the equilibrium of water and heat transfer in the air-vegetation interface is changed. (2) The integrated impact of the LULC variation on regional climate is not only limited to West China where the LULC varies, but also to some areas in the model domain where the LULC does not vary at all. (3) The East Asian monsoon system and its vertical structure are adjusted by the large scale LULC variation in western China, where the consequences axe the enhancement of the westward water vapor transfer from the east east and the relevant increase of wet-hydrostatic energy in the middle-upper atmospheric layers. (4) The ecological engineering in West China affects significantly the regional climate in Northwest China, North China and the middle-lower reaches of the Yangtze River; there are obvious effects in South, Northeast, and Southwest China, but minor effects in Tibet.

  17. Why do humans have chins? Testing the mechanical significance of modern human symphyseal morphology with finite element analysis.

    PubMed

    Gröning, Flora; Liu, Jia; Fagan, Michael J; O'Higgins, Paul

    2011-04-01

    The modern human mandibular symphysis differs from those of all other primates in being vertically orientated and possessing a chin, but the functional significance of this unique morphology is not well understood. Some hypotheses propose that it is an adaptation to specific loads occurring during masticatory function. This study uses finite element analysis to examine these symphyseal loads in a model of a modern human mandible. By modifying the symphyseal cross-sectional form, the mechanical significance of the presence of the chin and symphyseal orientation is tested, and modern human and Neanderthal symphyseal cross-sections are compared with regard to their ability to withstand different loads. The results show that changes in symphyseal form have profound effects on the strains. The presence of a chin leads to lower symphyseal strains overall, whereas a vertical orientation of the symphysis results in higher strains under wishboning, but not under vertical bending in the coronal plane and dorsoventral shear. Compared to Neanderthals, the modern human symphysis shows higher strains during dorsoventral shear and wishboning, but is as effective as the Neanderthal symphysis in resisting vertical bending in the coronal plane and the loads resulting from simulated incision and unilateral molar biting. In general, the results of this study corroborate prior hypotheses about the mechanical effects of the human chin and vertical symphyseal orientation and support the idea that the relative importance of wishboning and vertical bending in the coronal plane might have played a role in the evolution of modern human symphyseal morphology.

  18. Orientation feedback during simulated simple translation tests has little clinical significance on the magnitude and precision of glenohumeral joint translations.

    PubMed

    Musahl, Volker; Moore, Susan M; McMahon, Patrick J; Debski, Richard E

    2006-11-01

    The repeatability of shoulder instability clinical examinations has been reported to be poor, producing a large range of translations. The objective of this study was to determine the effect of providing the clinician with joint orientation feedback on the magnitude and precision of glenohumeral joint kinematics. A 6-degree of freedom magnetic tracking system was used to determine the kinematics of the humerus with respect to the scapula (n=8 cadaveric shoulders). The joints were preconditioned with simple loading tests five times. At 60 degrees of glenohumeral abduction and 0 degrees of flexion/extension, a clinician then applied an anterior and posterior load to the humerus until a manual maximum simulating a simple translation test (STT) was achieved at 0, 30, and 60 degrees of external rotation with and without angular orientation feedback of the humerus with respect to the scapula. The precision for the external rotation was within 4.3 degrees for the feedback group and 17.5 degrees for the no feedback group over all external rotations. For achieving the target external rotation of 30 degrees , there was a significant difference in precision between the feedback and no feedback groups (p<0.05). The magnitudes of the anterior translations were 18.2+/-5.3, 15.5+/-5.1, and 9.9+/-5.5 mm for the feedback group and 19.3+/-6.6, 17.5+/-4.9, and 11.5+/-5.3 mm for the no feedback group, at 0, 30, and 60 degrees of external rotation, respectively. There was a significant difference in the precision of anterior translation at 30 and 60 degrees of external rotation for 4 of 8 specimens (p<0.05). Significant differences in the precision of the posterior translation was only detected at 0 degrees of external rotation for 3 of 8 specimens (p<0.05). Based on the data obtained, providing orientation feedback to a clinician performing a simulated STT results in increased precision for not only the target external rotations but also the resulting glenohumeral translations. While

  19. Testing earthquake prediction algorithms: Statistically significant advance prediction of the largest earthquakes in the Circum-Pacific, 1992-1997

    USGS Publications Warehouse

    Kossobokov, V.G.; Romashkova, L.L.; Keilis-Borok, V. I.; Healy, J.H.

    1999-01-01

    Algorithms M8 and MSc (i.e., the Mendocino Scenario) were used in a real-time intermediate-term research prediction of the strongest earthquakes in the Circum-Pacific seismic belt. Predictions are made by M8 first. Then, the areas of alarm are reduced by MSc at the cost that some earthquakes are missed in the second approximation of prediction. In 1992-1997, five earthquakes of magnitude 8 and above occurred in the test area: all of them were predicted by M8 and MSc identified correctly the locations of four of them. The space-time volume of the alarms is 36% and 18%, correspondingly, when estimated with a normalized product measure of empirical distribution of epicenters and uniform time. The statistical significance of the achieved results is beyond 99% both for M8 and MSc. For magnitude 7.5 + , 10 out of 19 earthquakes were predicted by M8 in 40% and five were predicted by M8-MSc in 13% of the total volume considered. This implies a significance level of 81% for M8 and 92% for M8-MSc. The lower significance levels might result from a global change in seismic regime in 1993-1996, when the rate of the largest events has doubled and all of them become exclusively normal or reversed faults. The predictions are fully reproducible; the algorithms M8 and MSc in complete formal definitions were published before we started our experiment [Keilis-Borok, V.I., Kossobokov, V.G., 1990. Premonitory activation of seismic flow: Algorithm M8, Phys. Earth and Planet. Inter. 61, 73-83; Kossobokov, V.G., Keilis-Borok, V.I., Smith, S.W., 1990. Localization of intermediate-term earthquake prediction, J. Geophys. Res., 95, 19763-19772; Healy, J.H., Kossobokov, V.G., Dewey, J.W., 1992. A test to evaluate the earthquake prediction algorithm, M8. U.S. Geol. Surv. OFR 92-401]. M8 is available from the IASPEI Software Library [Healy, J.H., Keilis-Borok, V.I., Lee, W.H.K. (Eds.), 1997. Algorithms for Earthquake Statistics and Prediction, Vol. 6. IASPEI Software Library]. ?? 1999 Elsevier

  20. A review of 20 years of naive tests of significance for high-dimensional mean vectors and covariance matrices

    NASA Astrophysics Data System (ADS)

    Hu, Jiang; Bai, ZhiDong

    2016-12-01

    In this paper, we will introduce the so called naive tests and give a brief review on the newly development. Naive testing methods are easy to understand and performs robust especially when the dimension is large. In this paper, we mainly focus on reviewing some naive testing methods for the mean vectors and covariance matrices of high dimensional populations and believe this naive test idea can be wildly used in many other testing problems.

  1. Identifying significant gene‐environment interactions using a combination of screening testing and hierarchical false discovery rate control

    PubMed Central

    Shen, Li; Saykin, Andrew J.; Williams, Scott M.; Moore, Jason H.

    2016-01-01

    ABSTRACT Although gene‐environment (G× E) interactions play an important role in many biological systems, detecting these interactions within genome‐wide data can be challenging due to the loss in statistical power incurred by multiple hypothesis correction. To address the challenge of poor power and the limitations of existing multistage methods, we recently developed a screening‐testing approach for G× E interaction detection that combines elastic net penalized regression with joint estimation to support a single omnibus test for the presence of G× E interactions. In our original work on this technique, however, we did not assess type I error control or power and evaluated the method using just a single, small bladder cancer data set. In this paper, we extend the original method in two important directions and provide a more rigorous performance evaluation. First, we introduce a hierarchical false discovery rate approach to formally assess the significance of individual G× E interactions. Second, to support the analysis of truly genome‐wide data sets, we incorporate a score statistic‐based prescreening step to reduce the number of single nucleotide polymorphisms prior to fitting the first stage penalized regression model. To assess the statistical properties of our method, we compare the type I error rate and statistical power of our approach with competing techniques using both simple simulation designs as well as designs based on real disease architectures. Finally, we demonstrate the ability of our approach to identify biologically plausible SNP‐education interactions relative to Alzheimer's disease status using genome‐wide association study data from the Alzheimer's Disease Neuroimaging Initiative (ADNI). PMID:27578615

  2. Evidence for the different physiological significance of the 6- and 2-minute walk tests in multiple sclerosis

    PubMed Central

    2012-01-01

    Background Researchers have recently advocated for the 2-minute walk (2MW) as an alternative for the 6-minute walk (6MW) to assess long distance ambulation in persons with multiple sclerosis (MS). This recommendation has not been based on physiological considerations such as the rate of oxygen consumption (V·O2) over the 6MW range. Objective This study examined the pattern of change in V·O2 over the range of the 6MW in a large sample of persons with MS who varied as a function of disability status. Method Ninety-five persons with clinically-definite MS underwent a neurological examination for generating an Expanded Disability Status Scale (EDSS) score, and then completion of the 6MW protocol while wearing a portable metabolic unit and an accelerometer. Results There was a time main effect on V·O2 during the 6MW (p = .0001) such that V·O2 increased significantly every 30 seconds over the first 3 minutes of the 6MW, and then remained stable over the second 3 minutes of the 6MW. This occurred despite no change in cadence across the 6MW (p = .84). Conclusions The pattern of change in V·O2 indicates that there are different metabolic systems providing energy for ambulation during the 6MW in MS subjects and steady state aerobic metabolism is reached during the last 3 minutes of the 6MW. By extension, the first 3 minutes would represent a test of mixed aerobic and anaerobic work, whereas the second 3 minutes would represent a test of aerobic work during walking. PMID:22380843

  3. [Clinical studies in working populations: value and significance of anamnestic findings, clinical tests and instrumental tests for the diagnosis of musculoskeletal disorders of the upper extremities].

    PubMed

    De Marco, F; Menoni, O; Ricci, M G; Bonaiuti, D; Colombini, D; Occhipinti, E

    1996-01-01

    The authors discuss the value and significance of symptoms in WMSDs, considering that the anamnestic threshold proposed in epidemiological investigations cannot be used as clinical and diagnosing criteria. Some useful clinical procedures are suggested for cases where there is a suspicion of musculo-skeletal disorders of the cervical spine and upper limbs, bearing in mind that they are to be applied within the framework of health surveillance programmes undertaken by health care practitioners who are not specialists in orthopaedics, physiatrics or neurology. The recommendations for instrumental tests and specialist referrals are also discussed for the various disorders. The authors also provide flow charts for the diagnostic procedures pertaining to WMSDs. The Appendix shows a sample patient chart illustrating the proposed procedures; it also permits the findings to be encoded so that they can be stored in a dedicated database. The codes for diagnosing WMSDs are also reported for the same epidemiological purposes.

  4. Spore test parameters matter: Mesophilic and thermophilic spore counts detected in raw milk and dairy powders differ significantly by test method.

    PubMed

    Kent, D J; Chauhan, K; Boor, K J; Wiedmann, M; Martin, N H

    2016-07-01

    United States dairy industry exports have steadily risen in importance over the last 10yr, with dairy powders playing a particularly critical role. Currently, approximately half of US-produced nonfat dry milk and skim milk powder is exported. Reaching new and expanding existing export markets relies in part on the control of endospore-forming bacteria in dairy powders. This study reports baseline mesophilic and thermophilic spore counts and spore populations from 55 raw material samples (primarily raw milk) and 33 dairy powder samples from dairy powder processors across the United States. Samples were evaluated using various spore testing methodologies and included initial heat treatments of (1) 80°C for 12 min; (2) 100°C for 30 min; and (3) 106°C for 30 min. Results indicate that significant differences in both the level and population of spores were found for both raw milk and dairy powders with the various testing methods. Additionally, on average, spore counts were not found to increase significantly from the beginning to the end of dairy powder processing, most likely related to the absence of biofilm formation by processing plant-associated sporeformers (e.g., Anoxybacillus sp.) in the facilities sampled. Finally, in agreement with other studies, Bacillus licheniformis was found to be the most prevalent sporeformer in both raw materials and dairy powders, highlighting the importance of this organism in developing strategies for control and reduction of spore counts in dairy powders. Overall, this study emphasizes the need for standardization of spore enumeration methodologies in the dairy powder industry.

  5. A Rickettsiella Bacterium from the Hard Tick, Ixodes woodi: Molecular Taxonomy Combining Multilocus Sequence Typing (MLST) with Significance Testing

    PubMed Central

    Leclerque, Andreas; Kleespies, Regina G.

    2012-01-01

    Hard ticks (Acari: Ixodidae) are known to harbour intracellular bacteria from several phylogenetic groups that can develop both mutualistic and pathogenic relationships to the host. This is of particular importance for public health as tick derived bacteria can potentially be transmitted to mammals, including humans, where e.g. Rickettsia or Coxiella act as severe pathogens. Exact molecular taxonomic identification of tick associated prokaryotes is a necessary prerequisite of the investigation of their relationship to both the tick and possible vertebrate hosts. Previously, an intracellular bacterium had been isolated from a monosexual, parthenogenetically reproducing laboratory colony of females of the hard tick, Ixodes woodi Bishopp, and had preliminarily been characterized as a “Rickettsiella-related bacterium”. In the present molecular taxonomic study that is based on phylogenetic reconstruction from both 16 S ribosomal RNA and protein-encoding marker sequences complemented with likelihood-based significance testing, the bacterium from I. woodi has been identified as a strain of the taxonomic species Rickettsiella grylli. It is the first time that a multilocus sequence typing (MLST) approach based on a four genes comprising MLST scheme has been implemented in order to classify a Rickettsiella-like bacterium to this species. The study demonstrated that MLST holds potential for a better resolution of phylogenetic relationships within the genus Rickettsiella, but requires sequence determination from further Rickettsiella-like bacteria in order to complete the current still fragmentary picture of Rickettsiella systematics. PMID:22675436

  6. Chinese Students' Perceptions of the Value of Test Preparation Courses for the TOEFL iBT: Merit, Worth, and Significance

    ERIC Educational Resources Information Center

    Ma, Jia; Cheng, Liying

    2015-01-01

    Test preparation for high-stakes English language tests has received increasing research attention in the language assessment field; however, little is known about what aspects of test preparation students attend to and value. In this study, we considered the perspectives of 12 Chinese students who were enrolled in various academic programs in a…

  7. DOD Operational Testing: Oversight Has Resulted in Few Significant Disputes and Limited Program Cost and Schedule Increases

    DTIC Science & Technology

    2015-06-01

    requirement to complete IOT &E using production-representative systems. Program officials disagreed with DOT&E’s assessment that the material change was...through statistical analysis was the minimum number of cycles required to reduce test risk and demonstrate system effectiveness at IOT &E...planned for IOT &E at Fort Hood, which reduces risk identified in previous test proposals. Test efficiencies are expected from employing soldiers in IOT

  8. Significance of Iron(II,III) Hydroxycarbonate Green Rust in Arsenic Remediation Using Zerovalent Iron in Laboratory Column Tests

    EPA Science Inventory

    We examined the corrosion products of zerovalent iron used in three column tests for removing arsenic from water under dynamic flow conditions. Each column test lasted three- to four-months using columns consisting of a 10.3-cm depth of 50 : 50 (w : w, Peerless iron : sand) in t...

  9. Using the Coefficient of Determination "R"[superscript 2] to Test the Significance of Multiple Linear Regression

    ERIC Educational Resources Information Center

    Quinino, Roberto C.; Reis, Edna A.; Bessegato, Lupercio F.

    2013-01-01

    This article proposes the use of the coefficient of determination as a statistic for hypothesis testing in multiple linear regression based on distributions acquired by beta sampling. (Contains 3 figures.)

  10. 77 FR 21065 - Certain High Production Volume Chemicals; Test Rule and Significant New Use Rule; Fourth Group of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-09

    ... processors to develop screening-level health, environmental, and fate data based on the potential for... substances (NAICS codes 325 and 324110), e.g., chemical manufacturing and petroleum refineries. Processors of... substances to require manufacturers, importers, and processors to conduct testing to obtain screening...

  11. Implementation and Operational Research: Expedited Results Delivery Systems Using GPRS Technology Significantly Reduce Early Infant Diagnosis Test Turnaround Times.

    PubMed

    Deo, Sarang; Crea, Lindy; Quevedo, Jorge; Lehe, Jonathan; Vojnov, Lara; Peter, Trevor; Jani, Ilesh

    2015-09-01

    The objective of this study was to quantify the impact of a new technology to communicate the results of an infant HIV diagnostic test on test turnaround time and to quantify the association between late delivery of test results and patient loss to follow-up. We used data collected during a pilot implementation of Global Package Radio Service (GPRS) printers for communicating results in the early infant diagnosis program in Mozambique from 2008 through 2010. Our dataset comprised 1757 patient records, of which 767 were from before implementation and 990 from after implementation of expedited results delivery system. We used multivariate logistic regression model to determine the association between late result delivery (more than 30 days between sample collection and result delivery to the health facility) and the probability of result collection by the infant's caregiver. We used a sample selection model to determine the association between late result delivery to the facility and further delay in collection of results by the caregiver. The mean test turnaround time reduced from 68.13 to 41.05 days post-expedited results delivery system. Caregivers collected only 665 (37.8%) of the 1757 results. After controlling for confounders, the late delivery of results was associated with a reduction of approximately 18% (0.44 vs. 0.36; P < 0.01) in the probability of results collected by the caregivers (odds ratio = 0.67, P < 0.05). Late delivery of results was also associated with a further average increase in 20.91 days of delay in collection of results (P < 0.01). Early infant diagnosis program managers should further evaluate the cost-effectiveness of operational interventions (eg, GPRS printers) that reduce delays.

  12. Significance of iron(II,III) hydroxycarbonate green rust in arsenic remediation using zerovalent iron in laboratory column tests.

    PubMed

    Su, Chunming; Puls, Robert W

    2004-10-01

    We examined the corrosion products of zerovalent iron used in three column tests for removing arsenic from water under dynamic flow conditions. Each column test lasted 3-4 months using columns consisting of a 10.3-cm depth of 50:50 (w:w, Peerless iron:sand) in the middle and a 10.3cm depth of a sediment from Elizabeth City, NC, in both upper and lower portions of the 31-cm-long glass column (2.5 cm in diameter). The feeding solutions were 1 mg of As(V) L(-1) + 1 mg of As(III) L(-1) in 7 mM NaCl + 0.86 mM CaSO4 with or without added phosphate (0.5 or 1 mg of P L(-1)) and silicate (10 or 20 mg of Si L(-1)) at pH 6.5. Iron(II,III) hydroxycarbonate green rust (or simply, carbonate green rust) and magnetite were the major iron corrosion products identified with X-ray diffraction for the separated fractions (5 and 1 min sedimentation and residual). The presence of carbonate green rust was confirmed by scanning electron microscopy (hexagonal morphology) and FTIR-photoacoustic spectroscopy (interlayer carbonate stretching mode at 1352-1365 cm(-1)). X-ray photoelectron spectroscopy investigation revealed the presence of predominantly As(V) at the surface of corroded iron particles despite the fact that the feeding solution in contact with Peerless iron contained more As(III) than As(V) as a result of a preferential uptake of As(V) over As(III) by the Elizabeth City sediment. Extraction of separated corrosion products with 1.0 M HCI showed that from 86 to 96% of the total extractable As (6.9-14.6 g kg(-1)) was in the form of As(V) in agreement with the XPS results. Combined microscopic and macroscopic wet chemistry results suggest that sorbed As(III) was partially oxidized by the carbonate green rust at the early stage of iron corrosion. The column experiments suggest that either carbonate green rust is kinetically favored or is thermodynamically more stable than sulfate green rust in the studied Peerless iron corrosion systems.

  13. Methodological considerations of acoustic playbacks to test the behavioral significance of call directionality in male northern elephant seals (Mirounga angustirostris)

    NASA Astrophysics Data System (ADS)

    Holt, Marla M.; Insley, Stephen J.; Southall, Brandon L.; Schusterman, Ronald J.

    2005-09-01

    While attempting to gain access to receptive females, male northern elephant seals form dominance hierarchies through multiple dyadic interactions involving visual and acoustic signals. These signals are both highly stereotyped and directional. Previous behavioral observations suggested that males attend to the directional cues of these signals. We used in situ vocal playbacks to test whether males attend to directional cues of the acoustic components of a competitors calls (i.e., variation in call spectra and source levels). Here, we will focus on playback methodology. Playback calls were multiple exemplars of a marked dominant male from an isolated area, recorded with a directional microphone and DAT recorder and edited into a natural sequence that controlled call amplitude. Control calls were recordings of ambient rookery sounds with the male calls removed. Subjects were 20 marked males (10 adults and 10 subadults) all located at An~o Nuevo, CA. Playback presentations, calibrated for sound-pressure level, were broadcast at a distance of 7 m from each subject. Most responses were classified into the following categories: visual orientation, postural change, calling, movement toward or away from the loudspeaker, and re-directed aggression. We also investigated developmental, hierarchical, and ambient noise variables that were thought to influence male behavior.

  14. Environmental Assessment and Finding of No Significant Impact: The Nevada Test Site Development Corporations's Desert Rock Sky Park at the Nevada Test Site

    SciTech Connect

    N /A

    2000-03-01

    The United States Department of Energy has prepared an Environmental Assessment (DOE/EA-1300) (EA) which analyzes the potential environmental effects of developing operating and maintaining a commercial/industrial park in Area 22 of the Nevada Test Site, between Mercury Camp and U.S. Highway 95 and east of Desert Rock Airport. The EA evaluates the potential impacts of infrastructure improvements necessary to support fill build out of the 512-acre Desert Rock Sky Park. Two alternative actions were evaluated: (1) Develop, operate and maintain a commercial/industrial park in Area 22 of the Nevada Test Site, and (2) taking no action. The purpose and need for the commercial industrial park are addressed in Section 1.0 of the EA. A detailed description of the proposed action and alternatives is in section 2.0. Section 3.0 describes the affected environment. Section 4.0 the environmental consequences of the proposed action and alternative. Cumulative effects are addressed in Section 5.0. Mitigation measures are addressed in Section 6.0. The Department of Energy determined that the proposed action of developing, operating and maintaining a commercial/industrial park in Area 22 of the Nevada Test Site would best meet the needs of the agency.

  15. Methodology, results, and significance of an unsaturated-zone tracer test at an artificial-recharge facility, Tucson, Arizona

    USGS Publications Warehouse

    Graham, D.D.

    1989-01-01

    A tracer test conducted in 1987 at an artificial-recharge facility in Tucson, Arizona, indicates that solute movement through the poorly sorted stratified alluvial sediments in the unsaturated zone beneath a recharge basin takes place along preferential-flow paths. Movement of a tracer-laced pulse of reclaimed wastewater was monitored using pressure-vacuum lysimeters installed at depths that range from 11 to 45 ft below the bottom of the recharge basin. Tracer-breakthrough curves do not indicate a consistent relation between maximum tracer concentration and depth or between time of tracer breakthrough and depth. Apparent dispersion, as indicated by the slope of the rising leg of the tracer-breakthrough curve, shows no apparent relation with depth. In some cases, the tracer arrived earlier at deep sampling locations than at shallow ones. Velocity of solute flow ranged from 1.9 to 9.0 ft/day. Less interaction between recharge water and solid-phase materials in the unsaturated zone occurs under preferential-flow conditions than if flow occurred as a uniform wetting front. Flow of water through the unsaturated zone is concentrated into fingers or channels under preferential-flow conditions, and the renovating capability of soil is reduced because of the reduced surface area and reduced contact time in the biologically active part of the unsaturated profile. Chemical substances that normally would be decomposed by microbial activity or sorbed by sediment particles can move through the unsaturated zone and cause groundwater contamination under preferential-flow conditions. (USGS)

  16. The Case for Use of Simple Difference Scores to Test the Significance of Differences in Mean Rates of Change in Controlled Repeated Measurements Designs

    ERIC Educational Resources Information Center

    Overall, John E.; Tonidandel, Scott

    2010-01-01

    A previous Monte Carlo study examined the relative powers of several simple and more complex procedures for testing the significance of difference in mean rates of change in a controlled, longitudinal, treatment evaluation study. Results revealed that the relative powers depended on the correlation structure of the simulated repeated measurements.…

  17. Optimization of Deep Drilling Performance - Development and Benchmark Testing of Advanced Diamond Product Drill Bits & HP/HT Fluids to Significantly Improve Rates of Penetration

    SciTech Connect

    Alan Black; Arnis Judzis

    2005-09-30

    This document details the progress to date on the OPTIMIZATION OF DEEP DRILLING PERFORMANCE--DEVELOPMENT AND BENCHMARK TESTING OF ADVANCED DIAMOND PRODUCT DRILL BITS AND HP/HT FLUIDS TO SIGNIFICANTLY IMPROVE RATES OF PENETRATION contract for the year starting October 2004 through September 2005. The industry cost shared program aims to benchmark drilling rates of penetration in selected simulated deep formations and to significantly improve ROP through a team development of aggressive diamond product drill bit--fluid system technologies. Overall the objectives are as follows: Phase 1--Benchmark ''best in class'' diamond and other product drilling bits and fluids and develop concepts for a next level of deep drilling performance; Phase 2--Develop advanced smart bit-fluid prototypes and test at large scale; and Phase 3--Field trial smart bit--fluid concepts, modify as necessary and commercialize products. As of report date, TerraTek has concluded all Phase 1 testing and is planning Phase 2 development.

  18. Prognostic significance of electrical alternans versus signal averaged electrocardiography in predicting the outcome of electrophysiological testing and arrhythmia-free survival

    NASA Technical Reports Server (NTRS)

    Armoundas, A. A.; Rosenbaum, D. S.; Ruskin, J. N.; Garan, H.; Cohen, R. J.

    1998-01-01

    OBJECTIVE: To investigate the accuracy of signal averaged electrocardiography (SAECG) and measurement of microvolt level T wave alternans as predictors of susceptibility to ventricular arrhythmias. DESIGN: Analysis of new data from a previously published prospective investigation. SETTING: Electrophysiology laboratory of a major referral hospital. PATIENTS AND INTERVENTIONS: 43 patients, not on class I or class III antiarrhythmic drug treatment, undergoing invasive electrophysiological testing had SAECG and T wave alternans measurements. The SAECG was considered positive in the presence of one (SAECG-I) or two (SAECG-II) of three standard criteria. T wave alternans was considered positive if the alternans ratio exceeded 3.0. MAIN OUTCOME MEASURES: Inducibility of sustained ventricular tachycardia or fibrillation during electrophysiological testing, and 20 month arrhythmia-free survival. RESULTS: The accuracy of T wave alternans in predicting the outcome of electrophysiological testing was 84% (p < 0.0001). Neither SAECG-I (accuracy 60%; p < 0.29) nor SAECG-II (accuracy 71%; p < 0.10) was a statistically significant predictor of electrophysiological testing. SAECG, T wave alternans, electrophysiological testing, and follow up data were available in 36 patients while not on class I or III antiarrhythmic agents. The accuracy of T wave alternans in predicting the outcome of arrhythmia-free survival was 86% (p < 0.030). Neither SAECG-I (accuracy 65%; p < 0.21) nor SAECG-II (accuracy 71%; p < 0.48) was a statistically significant predictor of arrhythmia-free survival. CONCLUSIONS: T wave alternans was a highly significant predictor of the outcome of electrophysiological testing and arrhythmia-free survival, while SAECG was not a statistically significant predictor. Although these results need to be confirmed in prospective clinical studies, they suggest that T wave alternans may serve as a non-invasive probe for screening high risk populations for malignant ventricular

  19. The Effectiveness of Noninvasive Biomarkers to Predict Hepatitis B-Related Significant Fibrosis and Cirrhosis: A Systematic Review and Meta-Analysis of Diagnostic Test Accuracy

    PubMed Central

    Xu, Xue-Ying; Kong, Hong; Song, Rui-Xiang; Zhai, Yu-Han; Wu, Xiao-Fei; Ai, Wen-Si; Liu, Hong-Bo

    2014-01-01

    Noninvasive biomarkers have been developed to predict hepatitis B virus (HBV)-related fibrosis owing to the significant limitations of liver biopsy. Those biomarkers were initially derived from evaluation of hepatitis C virus (HCV)-related fibrosis, and their accuracy among HBV-infected patients was under constant debate. A systematic review was conducted on records in PubMed, EMBASE and the Cochrane Library electronic databases, up until April 1st, 2013, in order to systematically assess the effectiveness and accuracy of these biomarkers for predicting HBV-related fibrosis. The questionnaire for quality assessment of diagnostic accuracy studies (QUADAS) was used. Out of 115 articles evaluated for eligibility, 79 studies satisfied the pre-determined inclusion criteria for meta-analysis. Eventually, our final data set for the meta-analysis contained 30 studies. The areas under the SROC curve for APRI, FIB-4, and FibroTest of significant fibrosis were 0.77, 0.75, and 0.84, respectively. For cirrhosis, the areas under the SROC curve for APRI, FIB-4 and FibroTest were 0.75, 0.87, and 0.90, respectively. The heterogeneity of FIB-4 and FibroTest were not statistically significant. The heterogeneity of APRI for detecting significant fibrosis was affected by median age (P = 0.0211), and for cirrhosis was affected by etiology (P = 0.0159). Based on the analysis we claim that FibroTest has excellent diagnostic accuracy for identification of HBV-related significant fibrosis and cirrhosis. FIB-4 has modest benefits and may be suitable for wider scope implementation. PMID:24964038

  20. Use of the ThinPrep® Imaging System does not alter the frequency of interpreting Papanicolaou tests as atypical squamous cells of undetermined significance

    PubMed Central

    Thrall, Michael J; Russell, Donna K; Bonfiglio, Thomas A; Hoda, Rana S

    2008-01-01

    Background Automated screening of Papanicolaou tests (Pap tests) improves the productivity of cytopathology laboratories. The ThinPrep® Imaging System (TIS) has been widely adopted primarily for this reason for use on ThinPrep® Pap tests (TPPT). However, TIS may also influence the interpretation of Pap tests, leading to changes in the frequency of various interpretive categories. The effect of the TIS on rates of TPPT interpretation as atypical squamous cells of undetermined significance (ASC-US) is of concern because any shift in the frequency of ASC-US will alter the sensitivity and specificity of the Pap test. We have sought to determine whether automated screening of TPPT has altered ASC-US rates in our institution when compared with manual screening (MS) of TPPT. Methods A computerized search for all ASC-US with reflex Human Papillomavirus (HPV) testing over a one-year-period (7/1/06 to 6/30/07) was conducted. Cases included both TPPT screened utilizing TIS and screened manually. HPV test results for both groups were recorded. Pertinent follow-up cervical cytology and histology results were retrieved for the period extending to 11/30/07. Automated screening was in clinical use for 10 months prior to the start of the study. Results Automated screening was performed on 23,103 TPPT, of which 977 (4.23%) were interpreted as ASC-US. Over the same period, MS was performed on 45,789 TPPT, of which 1924 (4.20%) were interpreted as ASC-US. Reflex HPV testing was positive for high risk (HR) types in 47.4% of the TIS cases and 50.2% of MS cases. Follow-up cervical dysplasia found by colposcopy was also distributed proportionally between the two groups. Cervical intraepithelial neoplasia (CIN) was found on follow-up biopsy of 20.1% of the TIS cases (5.2% CIN 2/3) and 21.2% of MS cases (5.1% CIN 2/3). None of these differences were statistically significant. Conclusion Use of the ThinPrep® Imaging System did not appreciably change ASC-US rates or follow-up reflex HPV

  1. The significance of matrix effects on the measurement of lactate dehydrogenase (LD) activity using Kodak dry slide technology in the Ontario Laboratory Proficiency Testing Program.

    PubMed

    Hill, S A; Heathcote, J C; McQueen, M J

    1990-04-01

    A recent lactate dehydrogenase (LD) survey of the Laboratory Proficiency Testing Program (LPTP) of Ontario showed interlaboratory coefficients of variation ranging from 6.5% to 40% for five lyophilized vials on the 12 Kodak analyzers. All the LPTP survey samples had similar protein and LD isoenzyme electrophoretic patterns which remained unchanged after reconstitution and storage for 5 days at 4 degrees C, although the total LD activities fell. Four Ektachem 700 analyzers were subsequently tested using LPTP material and no difference in LD activity between instruments or between two LD slide lot numbers was shown. Generation 9 slides gave higher LD activities than generation 10 on all the reconstituted lyophilized proficiency testing samples. There was no significant difference between slide generations when 19 liquid human sera were analyzed, indicating that the variability on LPTP samples was due to a matrix effect. Definition of the matrix effect of lyophilized proficiency testing material is essential before any proficiency testing program can use such material to reflect analytical performance on patient specimens.

  2. Significance of a negative exercise thallium test in the presence of a critical residual stenosis after thrombolysis for acute myocardial infarction

    SciTech Connect

    Sutton, J.M.; Topol, E.J. )

    1991-04-01

    After thrombolytic therapy for acute myocardial infarction, increasing emphasis is placed on early submaximal exercise testing, with further intervention advocated only for demonstrable ischemia. Although significant residual coronary artery lesions after successful thrombolysis are common, many patients paradoxically have no corresponding provokable ischemia. The relation between significant postthrombolytic residual coronary artery disease and a negative early, submaximal exercise thallium-201 tomogram was studied among 101 consecutive patients with uncomplicated myocardial infarction and at least 70% residual stenosis of the infarct artery. A negative test occurred in 49 (48.5%) patients with a mean 88% residual infarct artery stenosis. Further characteristics of the group were as follows: mean time to treatment was 3.1 hours; mean age was 54 +/- 10 years; 80% were male; 47% had anterior infarction; 39% had multivessel disease; mean left ventricular ejection fraction was 53 +/- 14%; and mean peak creatine kinase level was 3,820 +/- 3,123 IU/ml. A similar group of 52 (51.5%) patients, treated within 3.3 hours from symptom onset, with a mean postthrombolysis stenosis of 90%, had a positive exercise test. Characteristics of this group were as follows: age was 58 +/- 10 years; 92% were male; 56% had anterior infarction; 40% had multivessel disease; and mean left ventricular ejection fraction was 54 +/- 15%. The peak creatine kinase level associated with the infarction, however, was lower: 2,605 +/- 1,805 IU/ml (p = 0.04). There was no difference in performance at exercise testing with respect to peak systolic pressure, peak heart rate, or time tolerated on the treadmill between the two groups. By multivariate logistic regression, only peak creatine kinase level predicted a negative stress result in the presence of a significant residual stenosis.

  3. Optimization of Deep Drilling Performance--Development and Benchmark Testing of Advanced Diamond Product Drill Bits & HP/HT Fluids to Significantly Improve Rates of Penetration

    SciTech Connect

    Alan Black; Arnis Judzis

    2003-10-01

    This document details the progress to date on the OPTIMIZATION OF DEEP DRILLING PERFORMANCE--DEVELOPMENT AND BENCHMARK TESTING OF ADVANCED DIAMOND PRODUCT DRILL BITS AND HP/HT FLUIDS TO SIGNIFICANTLY IMPROVE RATES OF PENETRATION contract for the year starting October 2002 through September 2002. The industry cost shared program aims to benchmark drilling rates of penetration in selected simulated deep formations and to significantly improve ROP through a team development of aggressive diamond product drill bit--fluid system technologies. Overall the objectives are as follows: Phase 1--Benchmark ''best in class'' diamond and other product drilling bits and fluids and develop concepts for a next level of deep drilling performance; Phase 2--Develop advanced smart bit--fluid prototypes and test at large scale; and Phase 3--Field trial smart bit--fluid concepts, modify as necessary and commercialize products. Accomplishments to date include the following: 4Q 2002--Project started; Industry Team was assembled; Kick-off meeting was held at DOE Morgantown; 1Q 2003--Engineering meeting was held at Hughes Christensen, The Woodlands Texas to prepare preliminary plans for development and testing and review equipment needs; Operators started sending information regarding their needs for deep drilling challenges and priorities for large-scale testing experimental matrix; Aramco joined the Industry Team as DEA 148 objectives paralleled the DOE project; 2Q 2003--Engineering and planning for high pressure drilling at TerraTek commenced; 3Q 2003--Continuation of engineering and design work for high pressure drilling at TerraTek; Baker Hughes INTEQ drilling Fluids and Hughes Christensen commence planning for Phase 1 testing--recommendations for bits and fluids.

  4. A new direction for prenatal chromosome microarray testing: software-targeting for detection of clinically significant chromosome imbalance without equivocal findings

    PubMed Central

    Bint, Susan; Irving, Melita D.; Kyle, Phillipa M.; Akolekar, Ranjit; Mohammed, Shehla N.; Mackie Ogilvie, Caroline

    2014-01-01

    Purpose. To design and validate a prenatal chromosomal microarray testing strategy that moves away from size-based detection thresholds, towards a more clinically relevant analysis, providing higher resolution than G-banded chromosomes but avoiding the detection of copy number variants (CNVs) of unclear prognosis that cause parental anxiety. Methods. All prenatal samples fulfilling our criteria for karyotype analysis (n = 342) were tested by chromosomal microarray and only CNVs of established deletion/duplication syndrome regions and any other CNV >3 Mb were detected and reported. A retrospective full-resolution analysis of 249 of these samples was carried out to ascertain the performance of this testing strategy. Results. Using our prenatal analysis, 23/342 (6.7%) samples were found to be abnormal. Of the remaining samples, 249 were anonymized and reanalyzed at full-resolution; a further 46 CNVs were detected in 44 of these cases (17.7%). None of these additional CNVs were of clear clinical significance. Conclusion. This prenatal chromosomal microarray strategy detected all CNVs of clear prognostic value and did not miss any CNVs of clear clinical significance. This strategy avoided both the problems associated with interpreting CNVs of uncertain prognosis and the parental anxiety that are a result of such findings. PMID:24795849

  5. OPTIMIZATION OF DEEP DRILLING PERFORMANCE--DEVELOPMENT AND BENCHMARK TESTING OF ADVANCED DIAMOND PRODUCT DRILL BITS & HP/HT FLUIDS TO SIGNIFICANTLY IMPROVE RATES OF PENETRATION

    SciTech Connect

    Alan Black; Arnis Judzis

    2004-10-01

    The industry cost shared program aims to benchmark drilling rates of penetration in selected simulated deep formations and to significantly improve ROP through a team development of aggressive diamond product drill bit--fluid system technologies. Overall the objectives are as follows: Phase 1--Benchmark ''best in class'' diamond and other product drilling bits and fluids and develop concepts for a next level of deep drilling performance; Phase 2--Develop advanced smart bit-fluid prototypes and test at large scale; and Phase 3--Field trial smart bit-fluid concepts, modify as necessary and commercialize products. As of report date, TerraTek has concluded all major preparations for the high pressure drilling campaign. Baker Hughes encountered difficulties in providing additional pumping capacity before TerraTek's scheduled relocation to another facility, thus the program was delayed further to accommodate the full testing program.

  6. Significance Testing Needs a Taxonomy: Or How the Fisher, Neyman-Pearson Controversy Resulted in the Inferential Tail Wagging the Measurement Dog.

    PubMed

    Bradley, Michael T; Brand, Andrew

    2016-10-01

    Accurate measurement and a cutoff probability with inferential statistics are not wholly compatible. Fisher understood this when he developed the F test to deal with measurement variability and to make judgments on manipulations that may be worth further study. Neyman and Pearson focused on modeled distributions whose parameters were highly determined and concluded that inferential judgments following an F test could be made with accuracy because the distribution parameters were determined. Neyman and Pearson's approach in the application of statistical analyses using alpha and beta error rates has played a dominant role guiding inferential judgments, appropriately in highly determined situations and inappropriately in scientific exploration. Fisher tried to explain the different situations, but, in part due to some obscure wording, generated a long standing dispute that currently has left the importance of Fisher's p < .05 criteria not fully understood and a general endorsement of the Neyman and Pearson error rate approach. Problems were compounded with power calculations based on effect sizes following significant results entering into exploratory science. To understand in a practical sense when each approach should be used, a dimension reflecting varying levels of certainty or knowledge of population distributions is presented. The dimension provides a taxonomy of statistical situations and appropriate approaches by delineating four zones that represent how well the underlying population of interest is defined ranging from exploratory situations to highly determined populations.

  7. Significant heat sensitivity increase detected in various types of diabetes mellitus patients by Akabane test for use of management of diabetic patients.

    PubMed

    Muzhikov, Valery; Vershinina, Elena; Belenky, Vadim; Muzhikov, Ruslan

    2016-01-01

    In order to assess patterns of heat sensitivity thresholds in patients with diabetes mellitus, the Akabane test was carried out on patients with insulin dependent diabetes mellitus (IDDM) (250 men and 309 women) and patients with noninsulin dependent diabetes mellitus (NIDDM) (158 men and 227 women). For comparison, a group of healthy subjects made up of 116 men and 277 women was also used. As soon as we revealed the influence of factors of pathology with a high significance level and gender and the interaction "gender*pathology", all the results are described separately for groups of men and women and for groups with IDDM and NIDDM. Simple effects of paired comparisons between healthy subjects, IDDM and NIDDM in groups of men and women, as well as comparisons between the profiles of men and women with IDDM and NIDDM showed significant differences between ACs in healthy subjects and those with each type of diabetes. The most significant differences are seen in the AC connected with the digestive system (SP pancreas channel), LR (liver channel), ST (stomach channel), GB (gall bladder channel). Thus, we revealed characteristic pattern of acupuncture channels (AC) lesions inherent to diabetes pathology, i.e. most vulnerable in diabetes ACs, being compromised in dependence from such factors, as type of diabetes, hyper or hypoglycemia, and from gender. The main value of the method lies in the fact that we observe the entire food chain from food ingestion to the utilization of carbohydrates with the opportunity to assess the activity of each organ and its regulatory contribution. On the basis of the body's response, an individual selection of medicines can be made, and by evaluating the individual biorhythms it is possible to determine the optimal time of administration.

  8. Evolutionary significance of geographic variation in a plumage-based foraging adaptation: an experimental test in the slate-throated redstart (Myioborus miniatus).

    PubMed

    Mumme, Ronald L; Galatowitsch, Mark L; Jabłoński, Piotr G; Stawarczyk, Tadeusz M; Cygan, Jakub P

    2006-05-01

    Geographic variation in the plumage pattern of birds is widespread but poorly understood, and in very few cases has its evolutionary significance been investigated experimentally. Neotropical warblers of the genus Myioborus use their contrasting black-and-white plumage to flush insect prey during animated foraging displays. Although previous experimental work has demonstrated that white plumage patches are critical to flush-pursuit foraging success, the amount of white in the plumage shows considerable interspecific and intraspecific geographic variation. We investigated the evolutionary significance of this geographic variation by experimentally decreasing or increasing the amount of white in the tail of slate-throated redstarts (Myioborus miniatus comptus) from Monteverde, Costa Rica, to mimic the natural extremes of tail pattern variation in this species. In addition to measuring the effects of plumage manipulation on foraging performance, we performed field experiments measuring the escape response of a common insect prey species (an asilid fly) using model redstarts representing four different Myioborus plumage patterns. Our experiments were designed to test four hypotheses that could explain geographic variation in plumage pattern. Compared to controls, experimental birds with reduced-white tails that mimic the plumage pattern of M. miniatus hellmayri of Guatemala showed significant reductions in flush-pursuit foraging performance. In contrast, the addition of white to the tail to mimic the plumage pattern of M. miniatus verticalis of Bolivia had no significant effect on foraging performance of Costa Rican redstarts. In field experiments with asilid flies, model redstarts simulating the plumage of M. miniatus comptus of Costa Rica and M. miniatus verticalis of Bolivia elicited greater responses than did models of other Myioborus taxa with either less or more white in the plumage. The results of our experiments with both birds and insects allow us to reject

  9. Relationship Between the Presence of Eczema Herpeticum and the Significance of Clinical and Laboratory Tests in Korean Children With Atopic Dermatitis

    PubMed Central

    Kim, Kohwoon; Kang, Junseok; Won Kim, Sung; Sung, Myongsoon

    2016-01-01

    Background Eczema herpeticum (EH) is a herpes simplex virus (HSV) infection superimposed on atopic dermatitis (AD). Objectives The aim of this study was to evaluate the relationship between clinical features and laboratory tests, including skin cultures, total IgE, eosinophil count, eosinophil cationic protein, and 25-hydroxyvitamin D3 (25-(OH)D3), in Korean children with AD according to the presence of EH. Patients and Methods We enrolled 380 patients aged 6 months to 18 years who were admitted to Busan St. Mary’s hospital from January 2012 to December 2014. All 380 subjects were divided into two groups: the control and the AD group. The AD group was further divided into two subgroups: EH+ and EH-. Results The male gender was related to the presence of EH (odds ratio of 2.56; 95% confidence interval, 1.19 - 5.53, P = 0.01), but age and 25-(OH)D3 levels were not. After adjusting for age, gender, and 25-(OH)D3, no significant relationship was found between total IgE, eosinophil cationic protein or eosinophil count levels and the presence of EH. The relationship between positive skin cultures and the presence of EH was significant (P < 0.001) and the presence of methicillin-resistant Staphylococcus aureus (MRSA) was also related to the development of EH (OR, 0.19; 95% CI, 0.04 - 0.92, P = 0.03). Conclusions We conclude that while male gender, positive skin culture results, and the presence of MRSA are factors influencing EH, serum 25-(OH)D3 levels are not associated with EH in Korean AD children. PMID:27713812

  10. Correcting the optimal resampling-based error rate by estimating the error rate of wrapper algorithms.

    PubMed

    Bernau, Christoph; Augustin, Thomas; Boulesteix, Anne-Laure

    2013-09-01

    High-dimensional binary classification tasks, for example, the classification of microarray samples into normal and cancer tissues, usually involve a tuning parameter. By reporting the performance of the best tuning parameter value only, over-optimistic prediction errors are obtained. For correcting this tuning bias, we develop a new method which is based on a decomposition of the unconditional error rate involving the tuning procedure, that is, we estimate the error rate of wrapper algorithms as introduced in the context of internal cross-validation (ICV) by Varma and Simon (2006, BMC Bioinformatics 7, 91). Our subsampling-based estimator can be written as a weighted mean of the errors obtained using the different tuning parameter values, and thus can be interpreted as a smooth version of ICV, which is the standard approach for avoiding tuning bias. In contrast to ICV, our method guarantees intuitive bounds for the corrected error. Additionally, we suggest to use bias correction methods also to address the conceptually similar method selection bias that results from the optimal choice of the classification method itself when evaluating several methods successively. We demonstrate the performance of our method on microarray and simulated data and compare it to ICV. This study suggests that our approach yields competitive estimates at a much lower computational price.

  11. A resampling-based Markovian model for automated colon cancer diagnosis.

    PubMed

    Ozdemir, Erdem; Sokmensuer, Cenk; Gunduz-Demir, Cigdem

    2012-01-01

    In recent years, there has been a great effort in the research of implementing automated diagnostic systems for tissue images. One major challenge in this implementation is to design systems that are robust to image variations. In order to meet this challenge, it is important to learn the systems on a large number of labeled images from a different range of variation. However, acquiring labeled images is quite difficult in this domain, and hence, the labeled training data are typically very limited. Although the issue of having limited labeled data is acknowledged by many researchers, it has rarely been considered in the system design. This paper successfully addresses this issue, introducing a new resampling framework to simulate variations in tissue images. This framework generates multiple sequences from an image for its representation and models them using a Markov process. Working with colon tissue images, our experiments show that this framework increases the generalization capacity of a learner by increasing the size and variation of the training data and improves the classification performance of a given image by combining the decisions obtained on its sequences.

  12. Co-Educational Tutorial Classes and Their Significance on Gendered Test Scores of Wollo University Students: A Before-After Analyses

    ERIC Educational Resources Information Center

    Gidey, Mu'uz

    2015-01-01

    This action research is carried out in a practical class room setting to devise an innovative way of administering tutorial classes to improve students' learning competence with particular reference to gendered test scores. A before-after test score analyses of mean and standard deviations along with t-statistical tests of hypotheses of second…

  13. Numerical study identifying the factors causing the significant underestimation of the specific discharge estimated using the modified integral pumping test method in a laboratory experiment.

    PubMed

    Sun, Kerang

    2015-09-01

    A three-dimensional finite element model is constructed to simulate the experimental conditions presented in a paper published in this journal [Goltz et al., 2009. Validation of two innovative methods to measure contaminant mass flux in groundwater. Journal of Contaminant Hydrology 106 (2009) 51-61] where the modified integral pumping test (MIPT) method was found to significantly underestimate the specific discharge in an artificial aquifer. The numerical model closely replicates the experimental configuration with explicit representation of the pumping well column and skin, allowing for the model to simulate the wellbore flow in the pumping well as an integral part of the porous media flow in the aquifer using the equivalent hydraulic conductivity approach. The equivalent hydraulic conductivity is used to account for head losses due to friction within the wellbore of the pumping well. Applying the MIPT method on the model simulated piezometric heads resulted in a specific discharge that underestimates the true specific discharge in the experimental aquifer by 18.8%, compared with the 57% underestimation of mass flux by the experiment reported by Goltz et al. (2009). Alternative simulation shows that the numerical model is capable of approximately replicating the experiment results when the equivalent hydraulic conductivity is reduced by an order of magnitude, suggesting that the accuracy of the MIPT estimation could be improved by expanding the physical meaning of the equivalent hydraulic conductivity to account for other factors such as orifice losses in addition to frictional losses within the wellbore. Numerical experiments also show that when applying the MIPT method to estimate hydraulic parameters, use of depth-integrated piezometric head instead of the head near the pump intake can reduce the estimation error resulting from well losses, but not the error associated with the well not being fully screened.

  14. [Significance of the control serum measurement in infectious disease tests--a case of lot-to-lot variation of anti-HIV antibody assay kit].

    PubMed

    Sasaki, Miho; Sasaki, Kenji

    2002-07-01

    We are using infectious disease test kits consisting of positive serum diluted with negative pooled serum (P-S) and positive control (P-C). In two anti-HIV antibody tests the results for both P-S and P-C fluctuated between positive and negative depending on the lot No. of the reagent. In Western blot tests carried out to confirm the tests, the P-C was found to be positive and the P-S tests were both inconclusive. We speculated that the P-S had very weak antibodies that reacted differently from patient samples. Manufacturers of such kits, however, must supply reagents with appropriate reactivity, so it is important that they be informed of inconsistencies that could invalidate cut-off values and lead to false-positives and false-negatives.

  15. Evaluation of a significantly shorter version of the Farnsworth-Munsell 100-hue test in patients with three different optic neuropathies.

    PubMed

    Nichols, B E; Thompson, H S; Stone, E M

    1997-03-01

    We tested the hypothesis that a subset of the Farnsworth-Munsell 100-hue test (FM-100) would be a sensitive, specific, and practical means of monitoring color vision in patients with chronic optic nerve disorders. We retrospectively analyzed the records of 1,113 patients affected with optic neuritis (ON), Graves' ophthalmopathy with suspected optic neuropathy, or idiopathic intracranial hypertension with suspected optic neuropathy (IIH). One hundred six records of patients showed that an FM-100 had been performed (23 ON, 46 Graves', 37 IIH). Forty additional patients were studied prospectively (11 ON, 17 Graves', 12 IIH). The sensitivity and specificity of all possible 21 chip subtests were compared against the same statistics for the entire test. We found that for these three optic nerve disorders, a test consisting of chips 22-42 had nearly the same sensitivity and specificity as the entire test when compared with the clinical diagnosis. At 90% specificity, the ratio of sensitivities of the short version to the original version of the test were IIH, 53%/45%; optic neuritis, 85%/79%; and Graves', 67%/70%. The majority of the clinical value of the test can be achieved in one fourth of the original examination time.

  16. Exploring Differential Effects across Two Decoding Treatments on Item-Level Transfer in Children with Significant Word Reading Difficulties: A New Approach for Testing Intervention Elements

    ERIC Educational Resources Information Center

    Steacy, Laura M.; Elleman, Amy M.; Lovett, Maureen W.; Compton, Donald L.

    2016-01-01

    In English, gains in decoding skill do not map directly onto increases in word reading. However, beyond the Self-Teaching Hypothesis, little is known about the transfer of decoding skills to word reading. In this study, we offer a new approach to testing specific decoding elements on transfer to word reading. To illustrate, we modeled word-reading…

  17. Performance on the Luria-Nebraska Neuropsychological Test Battery-Children's Revision: A Comparison of Children with and without Significant WISC-R VIQ-PIQ Discrepancies.

    ERIC Educational Resources Information Center

    Gilger, J. W.; Geary, D. C.

    1985-01-01

    Compared the performance of 56 children on the 11 subscales of the Luria-Nebraska Neuropsychological Battery-Children's Revision. Results revealed significant differences on Receptive Speech and Expressive Language subscales, suggesting a possible differential sensitivity of the children's Luria-Nebraska to verbal and nonverbal cognitive deficits.…

  18. Detection of anti-U3-RNP/fibrillarin IgG antibodies by line immunoblot assay has comparable clinical significance to immunoprecipitation testing in systemic sclerosis.

    PubMed

    Peterson, Lisa K; Jaskowski, Troy D; Mayes, Maureen D; Tebo, Anne E

    2016-04-01

    The aim of this study was to evaluate the performance and clinical relevance of a commercially available line immunoblot assay (LIA) for detecting anti-U3-RNP/fibrillarin (anti-U3-RNP), against immunoprecipitation (gold standard). This study involved a multi-ethnic cohort of 1000 American systemic sclerosis (SSc) patients and 50 healthy controls. Antinuclear antibodies and centromere antibodies were detected by indirect immunofluorescent antibody test, anti-topo I by immunodiffusion and anti-RNAP III by ELISA. The presence of anti-U3-RNP in select serum samples was detected by immunoprecipitation (IP) and LIA. By IP, U3-RNP antibody was detected in 75 (7.5 %) patients with SSc. Overall agreement between LIA and IP was very good (κ = 0.966). Analytic sensitivity and specificity of the U3-RNP LIA was 100 and 94.7 %, respectively. Clinical features associated with positivity for the anti-U3-RNP antibody include diffuse cutaneous SSc and increased prevalence of renal crisis, consistent with previous studies that used IP. Testing for U3-RNP antibodies is only performed by a small number of laboratories due to the complexity of both performance and interpretation of the IP. LIA is faster and less complex than IP. Excellent agreement between IP and LIA demonstrates that LIA is an acceptable and attractive alternative to IP for anti-U3-RNP detection.

  19. Results of in-situ biofouling control, and corrosion test at Punta Tuna, Puerto Rico and its significance on OTEC heater exchanger design

    SciTech Connect

    Sasscer, D.S.; Morgan, T.O.; Tosteson, T.R.

    1983-06-01

    Because Ocean Thermal Energy Conversion (OTEC) operates at a low thermodynamic efficiency, heat exchangers represent a major portion of the overall cost of an OTEC power plant. For this reason, the commercial viability of OTEC depends on the design of efficient and inexpensive heat exchangers which have an operational life expectancy of 20 to 30 years and which can be maintained at a high level of efficiency by the use of effective biofouling control. Summarized here are the results of experiments conducted by the Center for Energy and Environment Research of the University of Puerto Rico to: determine the nature of the biofilm which develops on heat exchanger surfaces exposed to running seawater, test the effectiveness of brush cleaning and chlorination in controlling biofouling on these surfaces and study the corrosion behavior of zinc protected aluminum alloys under OTEC conditions in an attempt to qualify them for use in low cost OTEC heat exchangers.

  20. Interim Guidance on the Treatment of Condensable Particulate Matter Test Results in the Prevention of Significant Deterioration and Nonattainment New Source Review Permitting Programs

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  1. Validation of the MicroScan-96 for the species identification and methicillin susceptibility testing of clinical significant coagulase-negative staphylococci.

    PubMed

    Patteet, L; Goossens, H; Ieven, M

    2012-05-01

    An automated system, MicroScan WalkAway-96, in conjugation with Combo Pos® 28 panels, was validated for the identification and methicillin susceptibility of coagulase-negative staphylococci (CNS). The performance of this system was evaluated on 428 CNS. Identification results were compared using a validated in-house method. Methicillin susceptibility was compared with oxacillin MIC testing and the presence of the mecA gene by PCR (in-house real-time method). The MicroScan system correctly identified 94.6% of the staphylococci (405 out of 428). 3.5% of the strains (15 out of 428) were not correctly identified. 1.9% of the isolates (8 out of 428) were correctly identified with a low probability. Identification of Staphylococcus warneri and Staphylococcus lugdunensis was determined with the least accuracy. Microscan combines both oxacillin and cefoxitin for determination of the methicillin susceptibility result. Correlation between this result and the mecA method was 97.6%. Correlation with the oxacillin MIC method was also 97.6%. Fourteen isolates showed a discrepant result, 8 were reported to be resistant in mecA-negative strains, 2 were reported false-susceptible in mecA positive strains and 4 strains showed a discrepant result with oxacillin MIC, but not with mecA determination. The automated system can be considered a simple and reliable method for identification and methicillin susceptibility of CNS.

  2. Targeted Resequencing and Systematic In Vivo Functional Testing Identifies Rare Variants in MEIS1 as Significant Contributors to Restless Legs Syndrome

    PubMed Central

    Schulte, Eva C.; Kousi, Maria; Tan, Perciliz L.; Tilch, Erik; Knauf, Franziska; Lichtner, Peter; Trenkwalder, Claudia; Högl, Birgit; Frauscher, Birgit; Berger, Klaus; Fietze, Ingo; Hornyak, Magdolna; Oertel, Wolfgang H.; Bachmann, Cornelius G.; Zimprich, Alexander; Peters, Annette; Gieger, Christian; Meitinger, Thomas; Müller-Myhsok, Bertram; Katsanis, Nicholas; Winkelmann, Juliane

    2014-01-01

    Restless legs syndrome (RLS) is a common neurologic condition characterized by nocturnal dysesthesias and an urge to move, affecting the legs. RLS is a complex trait, for which genome-wide association studies (GWASs) have identified common susceptibility alleles of modest (OR 1.2–1.7) risk at six genomic loci. Among these, variants in MEIS1 have emerged as the largest risk factors for RLS, suggesting that perturbations in this transcription factor might be causally related to RLS susceptibility. To establish this causality, direction of effect, and total genetic burden of MEIS1, we interrogated 188 case subjects and 182 control subjects for rare alleles not captured by previous GWASs, followed by genotyping of ∼3,000 case subjects and 3,000 control subjects, and concluded with systematic functionalization of all discovered variants using a previously established in vivo model of neurogenesis. We observed a significant excess of rare MEIS1 variants in individuals with RLS. Subsequent assessment of all nonsynonymous variants by in vivo complementation revealed an excess of loss-of-function alleles in individuals with RLS. Strikingly, these alleles compromised the function of the canonical MEIS1 splice isoform but were irrelevant to an isoform known to utilize an alternative 3′ sequence. Our data link MEIS1 loss of function to the etiopathology of RLS, highlight how combined sequencing and systematic functional annotation of rare variation at GWAS loci can detect risk burden, and offer a plausible explanation for the specificity of phenotypic expressivity of loss-of-function alleles at a locus broadly necessary for neurogenesis and neurodevelopment. PMID:24995868

  3. Power Differences among Tests of Combined Significance.

    ERIC Educational Resources Information Center

    Becker, Betsy Jane

    Power is an indicator of the ability of a statistical analysis to detect a phenomenon that does in fact exist. The issue of power is crucial for social science research because sample size, effects, and relationships studied tend to be small and the power of a study relates directly to the size of the effect of interest and the sample size.…

  4. Significant issues and changes for ANSI/ASME OM-1 1981, part 1, ASME OMc code-1994, and ASME OM Code-1995, Appendix I, inservice testing of pressure relief devices in light water reactor power plants

    SciTech Connect

    Seniuk, P.J.

    1996-12-01

    This paper identifies significant changes to the ANSI/ASME OM-1 1981, Part 1, and ASME Omc Code-1994 and ASME OM Code-1995, Appendix I, {open_quotes}Inservice Testing of Pressure Relief Devices in Light-Water Reactor Power Plants{close_quotes}. The paper describes changes to different Code editions and presents insights into the direction of the code committee and selected topics to be considered by the ASME O&M Working Group on pressure relief devices. These topics include scope issues, thermal relief valve issues, as-found and as-left set-pressure determinations, exclusions from testing, and cold setpoint bench testing. The purpose of this paper is to describe some significant issues being addressed by the O&M Working Group on Pressure Relief Devices (OM-1). The writer is currently the chair of OM-1 and the statements expressed herein represents his personal opinion.

  5. The significance of repeat testing in Turkish blood donors screened with HBV, HCV and HIV immunoassays and the importance of S/CO ratios in the interpretation of HCV/HIV screening test results and as a determinant for further confirmatory testing.

    PubMed

    Acar, Ali; Kemahli, Sabri; Altunay, Husnu; Kosan, Erdogan; Oncul, Oral; Gorenek, Levent; Cavuslu, Saban

    2010-06-01

    The purpose of this study was to investigate the intra-assay correlations amongst initial reactive and repeat screening results used in enzyme immunoassays (EIAs) for hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV in blood donors. This study evaluated the value of using the power of the signal to cut-off (S/CO) ratio index for confirming anti-HCV/HIV reactive screening results, thereby touching upon the utility of S/CO indices in determining whether further confirmatory testing was necessary. Screening test results of the 72,695 blood donors were evaluated over a 1-year period. Correlation analysis among each initial test and retests was done by Pearson r test. Appropriate S/CO values to determine the need of the confirmation testing was investigated by ROC analyses. EIA intra-assay correlations were of statistical significance and were determined as follows: 0.948 for anti-HCV, 0.827 for anti-HIV and 0.948 for HBsAg. The threshold S/CO ratio values which predicted more than 95% of the confirmation test result were 3.8 for HCV and 5.6 for HIV. We were able to demonstrate a strong level of intra-assay correlation amongst EIAs, thereby eliminating the need for repetition of the screening test. Hence, we suggest that repeat screening should only be limited to HBV and HIV tests with low EIA S/CO ratios. Thus, using the power of the S/CO ratio in determining the need for HCV confirmation testing can be a cost-effective measure, especially if the S/CO value is >or=3.8.

  6. The highly selective 5-hydroxytryptamine (5-HT)2A receptor antagonist, EMD 281014, significantly increases swimming and decreases immobility in male congenital learned helpless rats in the forced swim test.

    PubMed

    Patel, Jignesh G; Bartoszyk, Gerd D; Edwards, Emmeline; Ashby, Charles R

    2004-04-01

    We examined the effect of the highly selective 5-hydroxytryptamine (5-HT)(2A) receptor antagonist 7-[4-[2-(4-fluoro-phenyl)-ethyl]-piperazine-1-carbonyl]-1H-indole-3-carbonitrile HCl (EMD 281014) in congenital learned helpless male rats in the forced swim test. The administration of EMD-281014 (0.3-30 mg/kg i.p.) to congenital learned helpless rats dose-dependently and significantly (at 10 and 30 mg/kg) decreased immobility and increased swimming compared to vehicle-treated animals. Thus, EMD 281014 produces effects in the forced swim test resembling those of antidepressants.

  7. Prospective evaluation of the Hybrid Capture 2 and AMPLICOR human papillomavirus (HPV) tests for detection of 13 high-risk HPV genotypes in atypical squamous cells of uncertain significance.

    PubMed

    Halfon, Philippe; Trepo, Elisabeth; Antoniotti, Gilles; Bernot, Catherine; Cart-Lamy, Philippe; Khiri, Hacène; Thibaud, Didier; Marron, Jean; Martineau, Agnès; Pénaranda, Guillaume; Benmoura, Dominique; Blanc, Bernard

    2007-02-01

    The use of high-risk human papillomavirus (hrHPV) testing as an adjunct to cervical cytology in population-based screening programs is currently based on DNA hybridization and PCR assays. The aim of this study was to prospectively assess the diagnostic performance of the Hybrid Capture 2 test (HC2; Digene Corporation) in comparison with that of the recently developed PCR-based AMPLICOR HPV test (Roche Molecular Systems) for the detection of 13 hrHPV types. A reverse line blot hybridization assay (Innogenetics) was used as an internal reference standard in discordant cases. Two hundred seventy-one patients with atypical squamous cells of uncertain significance (ASCUS) in cervical samples underwent hrHPV testing. The chi-square test was performed to compare respective proportions. Totals of 160/271 (59%) and 156/271 (58%) were found to be positive for hrHPV with HC2 and AMPLICOR, respectively. Concordant results were obtained for 235 (86.7%) of the 271 samples (kappa statistic, 0.73 +/- 0.04). Considering types 26, 53, and 66 as oncogenic types, negative predictive values (NPVs) of HC2 and AMPLICOR were 92.8% and 87.8%, respectively (difference was not significant), and their respective accuracies were 94.8% and 91.9% (difference was not significant). Considering types 26, 53, and 66 as not oncogenic, the respective HC2 and AMPLICOR NPVs were 92.8% and 97.4% (difference was not significant), and accuracy was significantly higher for the AMPLICOR assay (95.9% versus 90.8% for HC2) (P<0.05). For ASCUS samples, the NPV was 92.8% for HC2 testing and might be compromised if the copy number of HPV DNA was low. The NPV was 97.4% for the AMPLICOR assay and might be compromised if HPV types 26, 53, and 66 were considered oncogenic. The accuracy of these two assays is good and is compatible with routine clinical use in the triage of ASCUS cases.

  8. Declinol, a Complex Containing Kudzu, Bitter Herbs (Gentian, Tangerine Peel) and Bupleurum, Significantly Reduced Alcohol Use Disorders Identification Test (AUDIT) Scores in Moderate to Heavy Drinkers: A Pilot Study

    PubMed Central

    Kushner, Steven; Han, David; Oscar-Berman, Marlene; William Downs, B; Madigan, Margaret A; Giordano, John; Beley, Thomas; Jones, Scott; Barh, Debmayla; Simpatico, Thomas; Dushaj, Kristina; Lohmann, Raquel; Braverman, Eric R; Schoenthaler, Stephen; Ellison, David; Blum, Kenneth

    2013-01-01

    It is well established that inherited human aldehyde dehydrogenase 2 (ALDH-2) deficiency reduces the risk for alcoholism. Kudzu plants and extracts have been used for 1,000 years in traditional Chinese medicine to treat alcoholism. Kudzu contains daidzin, which inhibits ALDH-2 and suppresses heavy drinking in rodents. Decreased drinking due to ALDH-2 inhibition is attributed to aversive properties of acetaldehyde accumulated during alcohol consumption. However not all of the anti-alcohol properties of diadzin are due to inhibition of ALDH-2. This is in agreement with our earlier work showing significant interaction effects of both pyrozole (ALDH-2 inhibitor) and methyl-pyrozole (non-inhibitor) and ethanol’s depressant effects. Moreover, it has been suggested that selective ALDH 2 inhibitors reduce craving for alcohol by increasing dopamine in the nucleus accumbens (NAc). In addition there is significant evidence related to the role of the genetics of bitter receptors (TAS2R) and its stimulation as an aversive mechanism against alcohol intake. The inclusion of bitters such as Gentian & Tangerine Peel in Declinol provides stimulation of gut TAS2R receptors which is potentially synergistic with the effects of Kudzu. Finally the addition of Radix Bupleuri in the Declinol formula may have some protective benefits not only in terms of ethanol induced liver toxicity but neurochemical actions involving endorphins, dopamine and epinephrine. With this information as a rationale, we report herein that this combination significantly reduced Alcohol Use Disorders Identification Test (AUDIT) scores administered to ten heavy drinkers (M=8, F=2; 43.2 ± 14.6 years) attending a recovery program. Specifically, from the pre-post comparison of the AUD scores, it was found that the score of every participant decreased after the intervention which ranged from 1 to 31. The decrease in the scores was found to be statistically significant with the p-value of 0.00298 (two-sided paired

  9. Indirect antiglobulin test-crossmatch using low-ionic-strength saline-albumin enhancement medium and reduced incubation time: effectiveness in the detection of most clinically significant antibodies and impact on blood utilization.

    PubMed

    Dinardo, C L; Bonifácio, S L; Mendrone, A

    2014-01-01

    Indirect antiglobulin test-crossmatch (IAT-XM) using enhancement media such as low-ionic-strength saline (LISS) and polyethylene glycol (PEG) usually requires 15 minutes of incubation. These methods are necessary when testing samples from blood recipients who have a higher risk of alloimmunization. In emergency situations, IAT-XM can be time-consuming and can influence presurgery routine, resulting in more red blood cell (RBC) units being tested and stored to avoid the transfusion of uncrossmatched ones. The objective of this study was to evaluate the performance of a LISS-albumin enhancer to intensify antigen-antibody reaction after 5 minutes of 37oC incubation and compare this performance with that of other enhancers, gel, and conventional tube testing. Second, the study evaluated the impact of this method's implementation in the C:T ratio (crossmatched to transfused RBC units) of a transfusion laboratory. Ninety serum samples containing alloantibodies of potential clinical significance were tested against phenotyped RBCs using four different methods: (1) tube with LISS-albumin enhancer (5 minutes of incubation), (2) tube with LISS-albumin and PEG (15 minutes of incubation), (3) gel, and (4) conventional tube method (60 minutes of incubation). In parallel, the study compared the C:T ratio of a tertiary-hospital transfusion laboratory in two different periods: 3 months before and 3 months after the implementation of the 5-minute IAT-XM protocol. The use of LISS-albumin with 5 minutes of incubation exhibited the same performance as LISS-albumin, PEG, and gel with 15 minutes of incubation. Conventional tube method results were equally comparable, but reactions were significantly less intense, except for anti-c (p = 0.406). Accuracy was 100 percent for all selected methods. After the implementation of the 5-minute IAT-XM protocol, the C:T ratio fell from 2.74 to 1.29 (p < 0.001). IAT-XM can have its incubation time reduced to 5 minutes with the use of LISS

  10. Spectral resampling based on user-defined inter-band correlation filter: C3 and C4 grass species classification

    NASA Astrophysics Data System (ADS)

    Adjorlolo, Clement; Mutanga, Onisimo; Cho, Moses A.; Ismail, Riyad

    2013-04-01

    In this paper, a user-defined inter-band correlation filter function was used to resample hyperspectral data and thereby mitigate the problem of multicollinearity in classification analysis. The proposed resampling technique convolves the spectral dependence information between a chosen band-centre and its shorter and longer wavelength neighbours. Weighting threshold of inter-band correlation (WTC, Pearson's r) was calculated, whereby r = 1 at the band-centre. Various WTC (r = 0.99, r = 0.95 and r = 0.90) were assessed, and bands with coefficients beyond a chosen threshold were assigned r = 0. The resultant data were used in the random forest analysis to classify in situ C3 and C4 grass canopy reflectance. The respective WTC datasets yielded improved classification accuracies (kappa = 0.82, 0.79 and 0.76) with less correlated wavebands when compared to resampled Hyperion bands (kappa = 0.76). Overall, the results obtained from this study suggested that resampling of hyperspectral data should account for the spectral dependence information to improve overall classification accuracy as well as reducing the problem of multicollinearity.

  11. The VITRO Score (Von Willebrand Factor Antigen/Thrombocyte Ratio) as a New Marker for Clinically Significant Portal Hypertension in Comparison to Other Non-Invasive Parameters of Fibrosis Including ELF Test

    PubMed Central

    Hametner, Stephanie; Ferlitsch, Arnulf; Ferlitsch, Monika; Etschmaier, Alexandra; Schöfl, Rainer; Ziachehabi, Alexander; Maieron, Andreas

    2016-01-01

    Background Clinically significant portal hypertension (CSPH), defined as hepatic venous pressure gradient (HVPG) ≥10 mmHg, causes major complications. HVPG is not always available, so a non-invasive tool to diagnose CSPH would be useful. VWF-Ag can be used to diagnose. Using the VITRO score (the VWF-Ag/platelet ratio) instead of VWF-Ag itself improves the diagnostic accuracy of detecting cirrhosis/ fibrosis in HCV patients. Aim This study tested the diagnostic accuracy of VITRO score detecting CSPH compared to HVPG measurement. Methods All patients underwent HVPG testing and were categorised as CSPH or no CSPH. The following patient data were determined: CPS, D’Amico stage, VITRO score, APRI and transient elastography (TE). Results The analysis included 236 patients; 170 (72%) were male, and the median age was 57.9 (35.2–76.3; 95% CI). Disease aetiology included ALD (39.4%), HCV (23.4%), NASH (12.3%), other (8.1%) and unknown (11.9%). The CPS showed 140 patients (59.3%) with CPS A; 56 (23.7%) with CPS B; and 18 (7.6%) with CPS C. 136 patients (57.6%) had compensated and 100 (42.4%) had decompensated cirrhosis; 83.9% had HVPG ≥10 mmHg. The VWF-Ag and the VITRO score increased significantly with worsening HVPG categories (P<0.0001). ROC analysis was performed for the detection of CSPH and showed AUC values of 0.92 for TE, 0.86 for VITRO score, 0.79 for VWF-Ag, 0.68 for ELF and 0.62 for APRI. Conclusion The VITRO score is an easy way to diagnose CSPH independently of CPS in routine clinical work and may improve the management of patients with cirrhosis. PMID:26895398

  12. Metallographic autopsies of full-scale ITER prototype cable-in-conduit conductors after full cyclic testing in SULTAN: II. Significant reduction of strand movement and strand damage in short twist pitch CICCs

    DOE PAGES

    Sanabria, Charlos; Lee, Peter J.; Starch, William; ...

    2015-10-14

    Prototype cable in conduit conductors (CICCs) destined for use in the Toroidal Field (TF) and Central Solenoid (CS) coils of the ITER experimental fusion reactor underwent severe cyclic loading in the SULTAN facility. Their autopsies revealed significant and permanent transverse strand migration due to the large Lorentz forces of the SULTAN test. The movement resulted in a 3 7% void fraction increase on the Low Pressure (LP) side of the longer twist pitch CICCs. However, short twist pitch conductors exhibited less than 1% void fraction increase in the LP side, as well as a complete absence of the Nb3Sn filamentmore » fractures observed in the longer twist pitch conductors. We report here a detailed strand to cable analysis of short and longer “baseline” twist pitch CICCs. It was found that the use of Internal Tin strands in the longer “baseline” twist pitch CICCs can be beneficial possibly because of their superior stiffness—which better resist strand movement—while the use of Bronze Process strands showed more movement and poorer cyclic test performance. This was not the case for the short twist pitch CICC. Such conductor design seems to work well with both strand types. But it was found that despite the absence of filament fractures, the short twist pitch CICC made from the Internal Tin strands studied here developed severe strand distortion during cabling which resulted in diffusion barrier breaks and Sn contamination of the Cu stabilizer during the heat treatment. Furthermore, the short twist pitch CICC made from Bronze Process strands preserved diffusion barrier integrity.« less

  13. Metallographic autopsies of full-scale ITER prototype cable-in-conduit conductors after full cyclic testing in SULTAN: II. Significant reduction of strand movement and strand damage in short twist pitch CICCs

    SciTech Connect

    Sanabria, Charlos; Lee, Peter J.; Starch, William; Devred, Arnaud; Larbalestier, David C.

    2015-10-14

    Prototype cable in conduit conductors (CICCs) destined for use in the Toroidal Field (TF) and Central Solenoid (CS) coils of the ITER experimental fusion reactor underwent severe cyclic loading in the SULTAN facility. Their autopsies revealed significant and permanent transverse strand migration due to the large Lorentz forces of the SULTAN test. The movement resulted in a 3 7% void fraction increase on the Low Pressure (LP) side of the longer twist pitch CICCs. However, short twist pitch conductors exhibited less than 1% void fraction increase in the LP side, as well as a complete absence of the Nb3Sn filament fractures observed in the longer twist pitch conductors. We report here a detailed strand to cable analysis of short and longer “baseline” twist pitch CICCs. It was found that the use of Internal Tin strands in the longer “baseline” twist pitch CICCs can be beneficial possibly because of their superior stiffness—which better resist strand movement—while the use of Bronze Process strands showed more movement and poorer cyclic test performance. This was not the case for the short twist pitch CICC. Such conductor design seems to work well with both strand types. But it was found that despite the absence of filament fractures, the short twist pitch CICC made from the Internal Tin strands studied here developed severe strand distortion during cabling which resulted in diffusion barrier breaks and Sn contamination of the Cu stabilizer during the heat treatment. Furthermore, the short twist pitch CICC made from Bronze Process strands preserved diffusion barrier integrity.

  14. Significant results: statistical or clinical?

    PubMed Central

    2016-01-01

    The null hypothesis significance test method is popular in biological and medical research. Many researchers have used this method for their research without exact knowledge, though it has both merits and shortcomings. Readers will know its shortcomings, as well as several complementary or alternative methods, as such the estimated effect size and the confidence interval. PMID:27066201

  15. Significance of periodogram peaks

    NASA Astrophysics Data System (ADS)

    Süveges, Maria; Guy, Leanne; Zucker, Shay

    2016-10-01

    Three versions of significance measures or False Alarm Probabilities (FAPs) for periodogram peaks are presented and compared for sinusoidal and box-like signals, with specific application on large-scale surveys in mind.

  16. Significance of brown dwarfs

    NASA Technical Reports Server (NTRS)

    Black, D. C.

    1986-01-01

    The significance of brown dwarfs for resolving some major problems in astronomy is discussed. The importance of brown dwarfs for models of star formation by fragmentation of molecular clouds and for obtaining independent measurements of the ages of stars in binary systems is addressed. The relationship of brown dwarfs to planets is considered.

  17. Significance Analysis of Prognostic Signatures

    PubMed Central

    Beck, Andrew H.; Knoblauch, Nicholas W.; Hefti, Marco M.; Kaplan, Jennifer; Schnitt, Stuart J.; Culhane, Aedin C.; Schroeder, Markus S.; Risch, Thomas; Quackenbush, John; Haibe-Kains, Benjamin

    2013-01-01

    A major goal in translational cancer research is to identify biological signatures driving cancer progression and metastasis. A common technique applied in genomics research is to cluster patients using gene expression data from a candidate prognostic gene set, and if the resulting clusters show statistically significant outcome stratification, to associate the gene set with prognosis, suggesting its biological and clinical importance. Recent work has questioned the validity of this approach by showing in several breast cancer data sets that “random” gene sets tend to cluster patients into prognostically variable subgroups. This work suggests that new rigorous statistical methods are needed to identify biologically informative prognostic gene sets. To address this problem, we developed Significance Analysis of Prognostic Signatures (SAPS) which integrates standard prognostic tests with a new prognostic significance test based on stratifying patients into prognostic subtypes with random gene sets. SAPS ensures that a significant gene set is not only able to stratify patients into prognostically variable groups, but is also enriched for genes showing strong univariate associations with patient prognosis, and performs significantly better than random gene sets. We use SAPS to perform a large meta-analysis (the largest completed to date) of prognostic pathways in breast and ovarian cancer and their molecular subtypes. Our analyses show that only a small subset of the gene sets found statistically significant using standard measures achieve significance by SAPS. We identify new prognostic signatures in breast and ovarian cancer and their corresponding molecular subtypes, and we show that prognostic signatures in ER negative breast cancer are more similar to prognostic signatures in ovarian cancer than to prognostic signatures in ER positive breast cancer. SAPS is a powerful new method for deriving robust prognostic biological signatures from clinically annotated

  18. Composite Defect Significance.

    DTIC Science & Technology

    1982-07-13

    A12i 299 COMPOSITE DEFECT SIGNIFICANCE(U) MATERIALS SCIENCES 1/1 \\ CORP SPRING HOUSE PA S N CHATTERJEE ET AL. 13 JUL 82 MSC/TFR/1288/il87 NADC-80848...Directorate 30 Sensors & Avionics Technology Directorate 40 Communication & Navigation Technology Directorate 50 Software Computer Directorate 60 Aircraft ...instructions concerning commercial products herein do not constitute an endorsement by the Government nor do they convey or imply the license or right to use

  19. Significant Tsunami Events

    NASA Astrophysics Data System (ADS)

    Dunbar, P. K.; Furtney, M.; McLean, S. J.; Sweeney, A. D.

    2014-12-01

    Tsunamis have inflicted death and destruction on the coastlines of the world throughout history. The occurrence of tsunamis and the resulting effects have been collected and studied as far back as the second millennium B.C. The knowledge gained from cataloging and examining these events has led to significant changes in our understanding of tsunamis, tsunami sources, and methods to mitigate the effects of tsunamis. The most significant, not surprisingly, are often the most devastating, such as the 2011 Tohoku, Japan earthquake and tsunami. The goal of this poster is to give a brief overview of the occurrence of tsunamis and then focus specifically on several significant tsunamis. There are various criteria to determine the most significant tsunamis: the number of deaths, amount of damage, maximum runup height, had a major impact on tsunami science or policy, etc. As a result, descriptions will include some of the most costly (2011 Tohoku, Japan), the most deadly (2004 Sumatra, 1883 Krakatau), and the highest runup ever observed (1958 Lituya Bay, Alaska). The discovery of the Cascadia subduction zone as the source of the 1700 Japanese "Orphan" tsunami and a future tsunami threat to the U.S. northwest coast, contributed to the decision to form the U.S. National Tsunami Hazard Mitigation Program. The great Lisbon earthquake of 1755 marked the beginning of the modern era of seismology. Knowledge gained from the 1964 Alaska earthquake and tsunami helped confirm the theory of plate tectonics. The 1946 Alaska, 1952 Kuril Islands, 1960 Chile, 1964 Alaska, and the 2004 Banda Aceh, tsunamis all resulted in warning centers or systems being established.The data descriptions on this poster were extracted from NOAA's National Geophysical Data Center (NGDC) global historical tsunami database. Additional information about these tsunamis, as well as water level data can be found by accessing the NGDC website www.ngdc.noaa.gov/hazard/

  20. Significance of research.

    PubMed

    Kanpolat, Y

    2002-01-01

    The development of the central nervous system (CNS) in humans is the most important factor differentiating the human being from other species. Intelligence is the most important result of evolution of the CNS in humans. However, human intelligence is not a static factor, having evolved during the historical progression of cultural factors and educational systems. Since the Middle Ages, universities have been the most dominant open-society institutions to regulate intellectual influences, share scientific knowledge and values, and promote research in natural sciences. Research is particularly important in contemporary neurosurgery and neurological sciences with regard to the development of new techniques and testing of the acquired knowledge of the CNS. Research activities in neuroscience and neurosurgery have especially involved anatomical and functional aspects. However, advances in molecular biology and genetics have been remarkably effective in research activities in neurosciences. Such progress will help us to understand nature, environment and humans. Of course, research is now a domain of method, organisation and financial gain. The dedication, heroism and creativity which used to be the driving forces behind scientific research are now diminishing in value and are a source of controversy.

  1. Fungi producing significant mycotoxins.

    PubMed

    2012-01-01

    Mycotoxins are secondary metabolites of microfungi that are known to cause sickness or death in humans or animals. Although many such toxic metabolites are known, it is generally agreed that only a few are significant in causing disease: aflatoxins, fumonisins, ochratoxin A, deoxynivalenol, zearalenone, and ergot alkaloids. These toxins are produced by just a few species from the common genera Aspergillus, Penicillium, Fusarium, and Claviceps. All Aspergillus and Penicillium species either are commensals, growing in crops without obvious signs of pathogenicity, or invade crops after harvest and produce toxins during drying and storage. In contrast, the important Fusarium and Claviceps species infect crops before harvest. The most important Aspergillus species, occurring in warmer climates, are A. flavus and A. parasiticus, which produce aflatoxins in maize, groundnuts, tree nuts, and, less frequently, other commodities. The main ochratoxin A producers, A. ochraceus and A. carbonarius, commonly occur in grapes, dried vine fruits, wine, and coffee. Penicillium verrucosum also produces ochratoxin A but occurs only in cool temperate climates, where it infects small grains. F. verticillioides is ubiquitous in maize, with an endophytic nature, and produces fumonisins, which are generally more prevalent when crops are under drought stress or suffer excessive insect damage. It has recently been shown that Aspergillus niger also produces fumonisins, and several commodities may be affected. F. graminearum, which is the major producer of deoxynivalenol and zearalenone, is pathogenic on maize, wheat, and barley and produces these toxins whenever it infects these grains before harvest. Also included is a short section on Claviceps purpurea, which produces sclerotia among the seeds in grasses, including wheat, barley, and triticale. The main thrust of the chapter contains information on the identification of these fungi and their morphological characteristics, as well as factors

  2. Human Papillomavirus (HPV) DNA Triage of Women with Atypical Squamous Cells of Undetermined Significance with cobas 4800 HPV and Hybrid Capture 2 Tests for Detection of High-Grade Lesions of the Uterine Cervix

    PubMed Central

    Lapierre, Simon Grandjean; Sauthier, Philippe; Mayrand, Marie-Hélène; Dufresne, Simon; Petignat, Patrick; Provencher, Diane; Drouin, Pierre; Gauthier, Philippe; Dupuis, Marie-Josée; Michon, Bertrand; Ouellet, Stéphan; Hadjeres, Rachid; Ferenczy, Alex; Franco, Eduardo L.

    2012-01-01

    The triage of women with high-risk (HR) human papillomavirus (HPV)-positive smears for atypical squamous cells of undetermined significance (ASC-US) to colposcopy is now an integrated option in clinical guidelines. The performance of cobas 4800 HPV and that of Hybrid Capture 2 (HC2) for HR HPV DNA detection in cervical samples in PreservCyt were compared in 396 women referred to colposcopy for ASC-US. Of these, 316 did not have cervical intraepithelial neoplasia (CIN), 47 had CIN1, 29 had CIN2 or CIN3 (CIN2+), and 4 had CIN of unknown grade. HR HPV was detected in 129 (32.6%) and 149 (37.6%) samples with HC2 and cobas 4800 HPV, respectively (P = 0.15). The clinical sensitivities and specificities for detecting CIN2+ were 89.7% (95% confidence interval [CI], 72.8 to 97.2%) and 66.7% (95% CI, 61.7 to 71.3%) with cobas 4800 HPV and 93.1% (95% CI, 77.0 to 99.2%) and 72.2% (95% CI 67.4 to 76.5%) with HC2. The performance of cobas 4800 HPV was similar to that of HC2 for identifying women with ASC-US who would benefit the most from colposcopy. PMID:22301023

  3. The significance of mitochondrial toxicity testing in drug development.

    PubMed

    Dykens, James A; Will, Yvonne

    2007-09-01

    Mitochondrial dysfunction is increasingly implicated in the etiology of drug-induced toxicities. Members of diverse drug classes undermine mitochondrial function, and among the most potent are drugs that have been withdrawn from the market, or have received Black Box warnings from the FDA. To avoid mitochondrial liabilities, routine screens need to be positioned within the drug-development process. Assays for mitochondrial function, cell models that better report mitochondrial impairment, and new animal models that more faithfully reflect clinical manifestations of mitochondrial dysfunction are discussed in the context of how such data can reduce late stage attrition of drug candidates and can yield safer drugs in the future.

  4. Sanitary Surveys & Significant Deficiencies Presentation

    EPA Pesticide Factsheets

    The Sanitary Surveys & Significant Deficiencies Presentation highlights some of the things EPA looks for during drinking water system site visits, how to avoid significant deficiencies and what to do if you receive one.

  5. Significance Alone Is Not Enough.

    ERIC Educational Resources Information Center

    Michalczyk, Alan E.; Lewis, Lloyd A.

    1980-01-01

    Thirty-three research articles based on t-tests, F-tests, or Pearson product-moment correlations selected from the "Journal of Medical Education" were examined for adequate research reporting. Nearly one-half did not report sufficient data or were found to have low power values. Guidelines for research reporting are discussed.…

  6. Significant Decisions in Labor Cases.

    ERIC Educational Resources Information Center

    Monthly Labor Review, 1979

    1979-01-01

    Several significant court decisions involving labor cases are discussed including a series of decisions concerning constitutional protections afforded aliens; the First Amendment and national labor relations laws; and the bifurcated backpay rule. (BM)

  7. Significant Scales in Community Structure

    PubMed Central

    Traag, V. A.; Krings, G.; Van Dooren, P.

    2013-01-01

    Many complex networks show signs of modular structure, uncovered by community detection. Although many methods succeed in revealing various partitions, it remains difficult to detect at what scale some partition is significant. This problem shows foremost in multi-resolution methods. We here introduce an efficient method for scanning for resolutions in one such method. Additionally, we introduce the notion of “significance” of a partition, based on subgraph probabilities. Significance is independent of the exact method used, so could also be applied in other methods, and can be interpreted as the gain in encoding a graph by making use of a partition. Using significance, we can determine “good” resolution parameters, which we demonstrate on benchmark networks. Moreover, optimizing significance itself also shows excellent performance. We demonstrate our method on voting data from the European Parliament. Our analysis suggests the European Parliament has become increasingly ideologically divided and that nationality plays no role. PMID:24121597

  8. Astronomical Significance of Ancient Monuments

    NASA Astrophysics Data System (ADS)

    Simonia, I.

    2011-06-01

    Astronomical significance of Gokhnari megalithic monument (eastern Georgia) is considered. Possible connection of Amirani ancient legend with Gokhnari monument is discussed. Concepts of starry practicality and solar stations are proposed.

  9. Statistical Significance vs. Practical Significance: An Exploration through Health Education

    ERIC Educational Resources Information Center

    Rosen, Brittany L.; DeMaria, Andrea L.

    2012-01-01

    The purpose of this paper is to examine the differences between statistical and practical significance, including strengths and criticisms of both methods, as well as provide information surrounding the application of various effect sizes and confidence intervals within health education research. Provided are recommendations, explanations and…

  10. Status and Significance of Credentialing.

    ERIC Educational Resources Information Center

    Musgrave, Dorothea

    1984-01-01

    Discusses the current status, significance, and future of credentialing in the field of environmental health. Also discusses four phases of a Bureau of Health Professions (BHP) Credentialing Program and BHP-funded projects related to their development and implementation. Phases include role delineation, resources development, examination…

  11. Statistical Significance of Threading Scores

    PubMed Central

    Fayyaz Movaghar, Afshin; Launay, Guillaume; Schbath, Sophie; Gibrat, Jean-François

    2012-01-01

    Abstract We present a general method for assessing threading score significance. The threading score of a protein sequence, thread onto a given structure, should be compared with the threading score distribution of a random amino-acid sequence, of the same length, thread on the same structure; small p-values point significantly high scores. We claim that, due to general protein contact map properties, this reference distribution is a Weibull extreme value distribution whose parameters depend on the threading method, the structure, the length of the query and the random sequence simulation model used. These parameters can be estimated off-line with simulated sequence samples, for different sequence lengths. They can further be interpolated at the exact length of a query, enabling the quick computation of the p-value. PMID:22149633

  12. PSD Significance Levels for Monitoring

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  13. Where boosted significances come from

    NASA Astrophysics Data System (ADS)

    Plehn, Tilman; Schichtel, Peter; Wiegand, Daniel

    2014-03-01

    In an era of increasingly advanced experimental analysis techniques it is crucial to understand which phase space regions contribute a signal extraction from backgrounds. Based on the Neyman-Pearson lemma we compute the maximum significance for a signal extraction as an integral over phase space regions. We then study to what degree boosted Higgs strategies benefit ZH and tt¯H searches and which transverse momenta of the Higgs are most promising. We find that Higgs and top taggers are the appropriate tools, but would profit from a targeted optimization towards smaller transverse momenta. MadMax is available as an add-on to MadGraph 5.

  14. Public health significance of neuroticism.

    PubMed

    Lahey, Benjamin B

    2009-01-01

    The personality trait of neuroticism refers to relatively stable tendencies to respond with negative emotions to threat, frustration, or loss. Individuals in the population vary markedly on this trait, ranging from frequent and intense emotional reactions to minor challenges to little emotional reaction even in the face of significant difficulties. Although not widely appreciated, there is growing evidence that neuroticism is a psychological trait of profound public health significance. Neuroticism is a robust correlate and predictor of many different mental and physical disorders, comorbidity among them, and the frequency of mental and general health service use. Indeed, neuroticism apparently is a predictor of the quality and longevity of our lives. Achieving a full understanding of the nature and origins of neuroticism, and the mechanisms through which neuroticism is linked to mental and physical disorders, should be a top priority for research. Knowing why neuroticism predicts such a wide variety of seemingly diverse outcomes should lead to improved understanding of commonalities among those outcomes and improved strategies for preventing them.

  15. Significance of biofilms in dentistry.

    PubMed

    Wróblewska, Marta; Strużycka, Izabela; Mierzwińska-Nastalska, Elżbieta

    2015-01-01

    In the past decades significant scientific progress has taken place in the knowledge about biofilms. They constitute multilayer conglomerates of bacteria and fungi, surrounded by carbohydrates which they produce, as well as substances derived from saliva and gingival fluid. Modern techniques showed significant diversity of the biofilm environment and a system of microbial communication (quorum sensing), enhancing their survival. At present it is believed that the majority of infections, particularly chronic with exacerbations, are a result of biofilm formation, particularly in the presence of biomaterials. It should be emphasised that penetration of antibiotics and other antimicrobial agents into deeper layers of a biofilm is poor, causing therapeutic problems and necessitating sometimes removal of the implant or prosthesis. Biofilms play an increasing role in dentistry as a result of more and more broad use in dental practice of plastic and implantable materials. Biofilms are produced on the surfaces of teeth as dental plaque, in the para-nasal sinuses, on prostheses, dental implants, as well as in waterlines of a dental unit, constituting a particular risk for severely immunocompromised patients. New methods of therapy and prevention of infections linked to biofilms are under development.

  16. Pathological Significance of Mitochondrial Glycation

    PubMed Central

    Pun, Pamela Boon Li; Murphy, Michael P.

    2012-01-01

    Glycation, the nonenzymatic glycosylation of biomolecules, is commonly observed in diabetes and ageing. Reactive dicarbonyl species such as methylglyoxal and glyoxal are thought to be major physiological precursors of glycation. Because these dicarbonyls tend to be formed intracellularly, the levels of advanced glycation end products on cellular proteins are higher than on extracellular ones. The formation of glycation adducts within cells can have severe functional consequences such as inhibition of protein activity and promotion of DNA mutations. Although several lines of evidence suggest that there are specific mitochondrial targets of glycation, and mitochondrial dysfunction itself has been implicated in disease and ageing, it is unclear if glycation of biomolecules specifically within mitochondria induces dysfunction and contributes to disease pathology. We discuss here the possibility that mitochondrial glycation contributes to disease, focussing on diabetes, ageing, cancer, and neurodegeneration, and highlight the current limitations in our understanding of the pathological significance of mitochondrial glycation. PMID:22778743

  17. [Hypertriglyceridemia: concept and clinical significance].

    PubMed

    Hirano, Tsutomu

    2013-09-01

    Hypertriglyceridemia is a common lipid disorder as well as hypercholesterolemia. However clinical significance of hypertriglyceridemia is not fully understood because of its heterogeneous lipoprotein phenotypes and complex etiology. Severe hypertriglyceridemia increases the risk for pancreatitis, whereas mild or moderate hypertriglyceridemia may be a risk factor for cardiovascular disease. Patients with hypertriglyceridemia are usually accompanied by other cardiovascular related disorders, such as central obesity, type 2 diabetes, and liver steatosis. Ectopic fat accumulation is often seen in hypertriglyceridemic subjects and various organ injuries are developed by the lipotoxicity. Hypertriglyceridemia is strongly associated with remnant lipoprotein accumulation, increased small dense LDL, and low HDL-cholesterol. All these lipid abnormalities are recognized as cardiovascular risk factors. The pathophysiology of lipoprotein metabolism related to the hypertriglyceridemia is summarized in this brief review.

  18. Astrobiological Significance of Chemolithoautotrophic Acidophiles

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.

    2003-01-01

    For more than a century (since Winogradsky discovered lithoautotrophic bacteria) a dilemma in microbiology has concerned life that first inhabited the Earth. Which types of life forms first appeared in the primordial oceans during the earliest geological period on Earth as the primary ancestors of modem biological diversity? How did a metabolism of ancestors evolve: from lithoautotrophic to lithohetherotrophic and organoheterotrophic or from organoheterotrophic to organoautotrophic and lithomixotrophic types? At the present time, it is known that chemolithoheterotrophic and chemolithoautotrophic metabolizing bacteria are wide spread in different ecosystems. On Earth the acidic ecosystems are associated with geysers, volcanic fumaroles, hot springs, deep sea hydrothermal vents, caves, acid mine drainage and other technogenic ecosystems. Bioleaching played a significant role on a global geological scale during the Earth's formation. This important feature of bacteria has been successfully applied in industry. The lithoautotrophs include Bacteria and Archaea belonging to diverse genera containing thermophilic and mesophilic species. In this paper we discuss the lithotrophic microbial acidophiles and present some data with a description of new acidophilic iron- and sulfur- oxidizing bacterium isolated from the Chena Hot Springs in Alaska. We also consider the possible relevance of microbial acidophiles to Venus, Io, and acidic inclusions in glaciers and icy moons.

  19. Statistically significant relational data mining :

    SciTech Connect

    Berry, Jonathan W.; Leung, Vitus Joseph; Phillips, Cynthia Ann; Pinar, Ali; Robinson, David Gerald; Berger-Wolf, Tanya; Bhowmick, Sanjukta; Casleton, Emily; Kaiser, Mark; Nordman, Daniel J.; Wilson, Alyson G.

    2014-02-01

    This report summarizes the work performed under the project (3z(BStatitically significant relational data mining.(3y (BThe goal of the project was to add more statistical rigor to the fairly ad hoc area of data mining on graphs. Our goal was to develop better algorithms and better ways to evaluate algorithm quality. We concetrated on algorithms for community detection, approximate pattern matching, and graph similarity measures. Approximate pattern matching involves finding an instance of a relatively small pattern, expressed with tolerance, in a large graph of data observed with uncertainty. This report gathers the abstracts and references for the eight refereed publications that have appeared as part of this work. We then archive three pieces of research that have not yet been published. The first is theoretical and experimental evidence that a popular statistical measure for comparison of community assignments favors over-resolved communities over approximations to a ground truth. The second are statistically motivated methods for measuring the quality of an approximate match of a small pattern in a large graph. The third is a new probabilistic random graph model. Statisticians favor these models for graph analysis. The new local structure graph model overcomes some of the issues with popular models such as exponential random graph models and latent variable models.

  20. Determining Semantically Related Significant Genes.

    PubMed

    Taha, Kamal

    2014-01-01

    GO relation embodies some aspects of existence dependency. If GO term xis existence-dependent on GO term y, the presence of y implies the presence of x. Therefore, the genes annotated with the function of the GO term y are usually functionally and semantically related to the genes annotated with the function of the GO term x. A large number of gene set enrichment analysis methods have been developed in recent years for analyzing gene sets enrichment. However, most of these methods overlook the structural dependencies between GO terms in GO graph by not considering the concept of existence dependency. We propose in this paper a biological search engine called RSGSearch that identifies enriched sets of genes annotated with different functions using the concept of existence dependency. We observe that GO term xcannot be existence-dependent on GO term y, if x- and y- have the same specificity (biological characteristics). After encoding into a numeric format the contributions of GO terms annotating target genes to the semantics of their lowest common ancestors (LCAs), RSGSearch uses microarray experiment to identify the most significant LCA that annotates the result genes. We evaluated RSGSearch experimentally and compared it with five gene set enrichment systems. Results showed marked improvement.

  1. Accretionary orogens: definition, character, significance

    NASA Astrophysics Data System (ADS)

    Cawood, P. A.; Kroener, A.; Windley, B. F.

    2003-04-01

    Classic models of orogens involve a Wilson cycle of ocean opening and closing with orogenesis related to continent-continent collision. Such models fail to explain the geological history of a significant number of orogenic belts throughout the world in which deformation, metamorphism and crustal growth took place in an environment of on-going plate convergence. These belts are termed accretionary orogens but have also been refereed to as non-collisional orogens, Pacific-type orogens, Turkic-type and exterior orogens. Accretionary orogens evolve in generally curvilinear belts comprising dominantly mafic to silicic igneous rocks and their sedimentary products and accumulated largely in marine settings. They are variably deformed and metamorphosed by tectono-thermal events aligned parallel to, and punctuating, facies trends. Accretionary orogens form at sites of subduction of oceanic lithosphere and consist of magmatic arcs systems along with material accreted from the downgoing plate and eroded from the upper plate. Deformational features include structures formed in extension and compressive environments during steady-state convergence (arc/backarc vs. accretionary prism) that are overprinted by short regional compressive orogenic events. Orogenesis takes place through coupling across the plate boundary with strain concentrated in zones of mechanical and thermal weakening such as the magmatic arc and back arc region. Potential driving mechanisms for coupling include accretion of buoyant lithosphere (terrane accretion), flat slab subduction, and rapid absolute upper plate motion over-riding the downgoing plate. The Circum-Pacific region provides outstanding examples of accretionary orogens. The Pacific formed during breakup of Rodinia in the Neoproterozoic and has never subsequently closed, resulting in a series of overall ocean-ward younging orogenic systems that have always faced an open ocean, yet have been the sites of repeated tectono-thermal events and

  2. Astrobiological Significance of Microbial Extremophiles

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.

    2007-01-01

    The microflora of the cryosphere of planet Earth provides the best analogs for life forms that might be found in the permafrost or polar ice caps of Mars, near the surface of the cometary nuclei, or in the liquid water beneath and the ice crusts of icy moons of Jupiter and Saturn. The importance of study alkaliphilic microorganisms for astrobiology was enhanced by the findings of abundant carbonates and carbonate globules rimmed with possibly biogenic magnetites in association with the putative microfossils in the ALH84001 meteorite. Although the ALH84001 "nanofossils" were to small and simple to be unambiguously recognized as biogenic, they stimulated Astrobiology research and studies of microbial extremophiles and biomarkers in ancient rocks and meteorites. Recent studies of CI and CM carbonaceous meteorites have resulted in the detection of the well-preserved mineralized remains of coccoidal and filamentous microorganisms in cyanobacterial mats. Energy Dispersive X-ray Analysis has shown anomalous biogenic element ratios clearly indicating they are not recent biological contaminants. This paper reviews microbial extremophiles in context of their significance to Astrobiology. The study of halophilic microorganisms was started from work with saline soils and lakes, and one of the record of good growth for Haloferax mediterranei was shown at 30 percent NaC1. Although alkali-tolerant nitrifying bacteria had previously been reported, the first described alkaliphilic microorganism was the bacterium Streptococcus faecalis. Halophilic and alkaliphilic forms are relevant to conditions that might be found in closed impact basins and craters on Mars filled with evaporite deposits. The first obligately acidophilic bacterium described was Acidithiobacillus ferrooxydans (formally Thiobacillus ferrooxidans). Later thermophilic lithotrophic acidophiles were found, and the hyperacidophilic moderately thermophilic species of the genus Picrophilus were found to grow at negative p

  3. Test Architecture, Test Retrofit

    ERIC Educational Resources Information Center

    Fulcher, Glenn; Davidson, Fred

    2009-01-01

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

  4. Assessing the significant others of chronic pain patients: the psychometric properties of significant other questionnaires.

    PubMed

    Sharp, T J; Nicholas, M K

    2000-11-01

    Contemporary reviews of psychological models of chronic pain have favoured behavioural and cognitive-behavioural formulations. These have often assumed that pain behaviours are maintained by environmental reinforcers. One of the most commonly hypothesized sources of reinforcement has been patients' significant others. Further, it has often been recognized that significant others may also be affected by pain behaviours and that they may experience changes in their lifesyles and in their mood as a consequence of living with someone who has pain. Somewhat surprisingly, relatively little clinical research has been published investigating significant others and their relationships with pain patients. Among other things, one of the limiting factors has been the lack of measurement tools available for assessing the relevant variables thought to be important with regards to significant others (such as their responses to, and perceptions of, chronic pain). This study attempted to remedy this situation by developing and testing the psychometric properties of a number of questionnaires specifically designed for significant others of chronic pain patients. The questionnaires have been selected to assess both significant others' (behavioural and cognitive) responses to pain as well as the extent to which pain impacts on their lives. Although not all of the questionnaires were found to possess equally strong psychometric properties, the availability of several solid measures opens the way for more empirical analyses of significant others and their interactions with chronic pain patients.

  5. Titanium Honeycomb Panel Testing

    NASA Technical Reports Server (NTRS)

    Richards, W. Lance; Thompson, Randolph C.

    1996-01-01

    Thermal-mechanical tests were performed on a titanium honeycomb sandwich panel to experimentally validate the hypersonic wing panel concept and compare test data with analysis. Details of the test article, test fixture development, instrumentation, and test results are presented. After extensive testing to 900 deg. F, non-destructive evaluation of the panel has not detected any significant structural degradation caused by the applied thermal-mechanical loads.

  6. Liquid Rocket Engine Testing

    NASA Technical Reports Server (NTRS)

    Rahman, Shamim

    2005-01-01

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

  7. Test plan :

    SciTech Connect

    Dwyer, Stephen F.

    2013-05-01

    This test plan is a document that provides a systematic approach to the planned testing of rooftop structures to determine their actual load carrying capacity. This document identifies typical tests to be performed, the responsible parties for testing, the general feature of the tests, the testing approach, test deliverables, testing schedule, monitoring requirements, and environmental and safety compliance.

  8. Pinworm test

    MedlinePlus

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

  9. Thyroid Tests

    MedlinePlus

    ... calories and how fast your heart beats. Thyroid tests check how well your thyroid is working. They ... thyroid diseases such as hyperthyroidism and hypothyroidism. Thyroid tests include blood tests and imaging tests. Blood tests ...

  10. Susceptibility Testing

    MedlinePlus

    ... Also known as: Sensitivity Testing; Drug Resistance Testing; Culture and Sensitivity; C & S; Antimicrobial Susceptibility Formal name: Bacterial and Fungal Susceptibility Testing Related tests: Urine Culture ; Blood Culture ; Bacterial Wound Culture ; AFB Testing ; MRSA ; ...

  11. Clinical significance of autoantibodies in autoimmune hepatitis.

    PubMed

    Liberal, Rodrigo; Mieli-Vergani, Giorgina; Vergani, Diego

    2013-10-01

    The accurate diagnosis and classification of autoimmune hepatitis (AIH) rely upon the detection of characteristic autoantibodies. Positivity for anti-nuclear (ANA) and/or anti-smooth muscle (SMA) autoantibodies defines AIH type 1 (AIH-1), whereas anti-liver kidney microsomal type 1 (anti-LKM1) and/or anti-liver cytosol type 1 (anti-LC1) define AIH type 2 (AIH-2). ANA and SMA, and less commonly anti-LKM1, have also been detected in de-novo autoimmune hepatitis developing after liver transplantation, a condition that may affect patients transplanted for non-autoimmune liver disease. The diagnostic autoantibodies associated with AIH-1 are also detected in the paediatric AIH/sclerosing cholangitis overlap syndrome, referred to as autoimmune sclerosing cholangitis (ASC). ASC, like adult primary sclerosing cholangitis, is often associated with atypical perinuclear anti-neutrophil cytoplasmic autoantibodies (p-ANCA), although p-ANCA are also detected in other autoimmune liver diseases. These associations highlight the necessity for simple and prompt diagnostic autoantibody testing, and the requirement for the accurate interpretation of the results of the tests in the clinical context. Fine-mapping of antigenic autoantibody targets has facilitated the development of rapid molecular assays that have the potential to revolutionise the field if properly standardised and when used in combination with classical immunofluorescence. Despite their diagnostic significance, the pathogenic role of the various autoantibodies and the mechanisms by which they can potentially inflict damage onto the liver cell remain a topic for further research.

  12. Quantifying the Clinical Significance of Cannabis Withdrawal

    PubMed Central

    Allsop, David J.; Copeland, Jan; Norberg, Melissa M.; Fu, Shanlin; Molnar, Anna; Lewis, John; Budney, Alan J.

    2012-01-01

    Background and Aims Questions over the clinical significance of cannabis withdrawal have hindered its inclusion as a discrete cannabis induced psychiatric condition in the Diagnostic and Statistical Manual of Mental Disorders (DSM IV). This study aims to quantify functional impairment to normal daily activities from cannabis withdrawal, and looks at the factors predicting functional impairment. In addition the study tests the influence of functional impairment from cannabis withdrawal on cannabis use during and after an abstinence attempt. Methods and Results A volunteer sample of 49 non-treatment seeking cannabis users who met DSM-IV criteria for dependence provided daily withdrawal-related functional impairment scores during a one-week baseline phase and two weeks of monitored abstinence from cannabis with a one month follow up. Functional impairment from withdrawal symptoms was strongly associated with symptom severity (p = 0.0001). Participants with more severe cannabis dependence before the abstinence attempt reported greater functional impairment from cannabis withdrawal (p = 0.03). Relapse to cannabis use during the abstinence period was associated with greater functional impairment from a subset of withdrawal symptoms in high dependence users. Higher levels of functional impairment during the abstinence attempt predicted higher levels of cannabis use at one month follow up (p = 0.001). Conclusions Cannabis withdrawal is clinically significant because it is associated with functional impairment to normal daily activities, as well as relapse to cannabis use. Sample size in the relapse group was small and the use of a non-treatment seeking population requires findings to be replicated in clinical samples. Tailoring treatments to target withdrawal symptoms contributing to functional impairment during a quit attempt may improve treatment outcomes. PMID:23049760

  13. Exercise oscillatory ventilation: Mechanisms and prognostic significance

    PubMed Central

    Dhakal, Bishnu P; Lewis, Gregory D

    2016-01-01

    Alteration in breathing patterns characterized by cyclic variation of ventilation during rest and during exercise has been recognized in patients with advanced heart failure (HF) for nearly two centuries. Periodic breathing (PB) during exercise is known as exercise oscillatory ventilation (EOV) and is characterized by the periods of hyperpnea and hypopnea without interposed apnea. EOV is a non-invasive parameter detected during submaximal cardiopulmonary exercise testing. Presence of EOV during exercise in HF patients indicates significant impairment in resting and exercise hemodynamic parameters. EOV is also an independent risk factor for poor prognosis in HF patients both with reduced and preserved ejection fraction irrespective of other gas exchange variables. Circulatory delay, increased chemosensitivity, pulmonary congestion and increased ergoreflex signaling have been proposed as the mechanisms underlying the generation of EOV in HF patients. There is no proven treatment of EOV but its reversal has been noted with phosphodiesterase inhibitors, exercise training and acetazolamide in relatively small studies. In this review, we discuss the mechanistic basis of PB during exercise and the clinical implications of recognizing PB patterns in patients with HF. PMID:27022457

  14. Statistical Significance of Clustering using Soft Thresholding

    PubMed Central

    Huang, Hanwen; Liu, Yufeng; Yuan, Ming; Marron, J. S.

    2015-01-01

    Clustering methods have led to a number of important discoveries in bioinformatics and beyond. A major challenge in their use is determining which clusters represent important underlying structure, as opposed to spurious sampling artifacts. This challenge is especially serious, and very few methods are available, when the data are very high in dimension. Statistical Significance of Clustering (SigClust) is a recently developed cluster evaluation tool for high dimensional low sample size data. An important component of the SigClust approach is the very definition of a single cluster as a subset of data sampled from a multivariate Gaussian distribution. The implementation of SigClust requires the estimation of the eigenvalues of the covariance matrix for the null multivariate Gaussian distribution. We show that the original eigenvalue estimation can lead to a test that suffers from severe inflation of type-I error, in the important case where there are a few very large eigenvalues. This paper addresses this critical challenge using a novel likelihood based soft thresholding approach to estimate these eigenvalues, which leads to a much improved SigClust. Major improvements in SigClust performance are shown by both mathematical analysis, based on the new notion of Theoretical Cluster Index, and extensive simulation studies. Applications to some cancer genomic data further demonstrate the usefulness of these improvements. PMID:26755893

  15. Test Anxiety, Test Comfort and Student Achievement Test Performance.

    ERIC Educational Resources Information Center

    Fyans, Leslie J., Jr.

    The Illinois Inventory of Educational Progress (IIEP) Test Comfort Scale was administered and test results were studied in terms of student achievement and correlates of achievement. Using the revised, seven-item scale, it was determined that: in grade 4, there was no main significant effect for sex or ethnic differences, although Orientals and…

  16. NGST Optical Testing

    NASA Technical Reports Server (NTRS)

    Keski-Kuha, Ritva

    1999-01-01

    An Integrated Product Team (IPT) was formed to develop a detailed optical test methodology for testing of the Next Generation Space Telescope (NGST) mirrors and the optical system on the ground. Optical testing is a significant cost driver therefore the testing has to be planned in detailed fashion early. This paper will discuss the preliminary metrology test plan at the mirror component and telescope system level. Instrumentation, facilities and schedule will also be addressed.

  17. Pharmacogenomic Testing

    MedlinePlus

    ... Primary care providers Specialists Getting covered Research Basic science research Research in people ... screening Diagnostic testing Direct-to-consumer genetic testing Newborn screening Pharmacogenomic testing ...

  18. Predictive Testing

    MedlinePlus

    ... Primary care providers Specialists Getting covered Research Basic science research Research in people ... screening Diagnostic testing Direct-to-consumer genetic testing Newborn screening Pharmacogenomic testing ...

  19. Pregnancy Tests

    MedlinePlus

    ... Us Home A-Z Health Topics Pregnancy tests Pregnancy tests > A-Z Health Topics Pregnancy test fact ... To receive Publications email updates Enter email Submit Pregnancy tests If you think you may be pregnant , ...

  20. VDRL test

    MedlinePlus

    ... The VDRL test is a screening test for syphilis. It measures substances (proteins), called antibodies, that your ... come in contact with the bacteria that cause syphilis. How the Test is Performed The test is ...

  1. Coombs test

    MedlinePlus

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

  2. Ham test

    MedlinePlus

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

  3. Trichomonas Testing

    MedlinePlus

    ... Trichomonas vaginalis by Amplified Detection; Trichomonas vaginalis by Direct Fluorescent Antibody (DFA) Related tests: Pap Test , Chlamydia ... by one of the following methods: Molecular testing, direct DNA probes, or nucleic acid amplification tests (NAATs)— ...

  4. TAXONOMICALLY SIGNIFICANT COLOR REACTIONS OF BREVIBACTERIUM LINENS

    PubMed Central

    Grecz, Nicholas; Dack, Gail M.

    1961-01-01

    Grecz, Nicholas (University of Chicago, Chicago, Ill.), and Gail M. Dack. Taxonomically significant color reactions of Brevibacterium linens. J. Bacteriol. 82:241–246. 1961.—Brevibacterium linens was observed to give characteristic color reactions with certain bases and acids. An intensive carmine-red color appeared immediately after addition of a drop of 5 n sodium hydroxide, 5 n potassium hydroxide, and saturated barium hydroxide. A light carmine-red was given by lithium hydroxide, and a light orange-red with a milky suspension of calcium hydroxide. No discernible color change was given with weak bases such as ammonium hydroxide, aniline, and pyridine. A characteristic salmon-pink color was produced when B. linens was rubbed with a glass rod in a drop of glacial acetic acid or filter paper; a brick-red color was produced with aniline under these conditions. With syrupy phosphoric acid a green color appeared within 3 to 4 min which turned blue after approximately 3 hr. The blue color was stable for several days. On the basis of these color reactions, B. linens could be distinguished from other microorganisms possessing yellow-orange pigmentation, i.e., Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus flavus, Micrococcus citreus, Mycobacterium phlei, Sarcina lutea. Therefore, these color changes may be used for the identification of B. linens. Original isolates of B. linens from cheese were tested by these spot reactions and all presumptive identifications could be subsequently confirmed by conventional methods. Blue and green colors appeared in all yellow-orange chromogens treated with sulfuric, perchloric, and hydrochloric acids and hence these colors were not specific for B. linens. PMID:13708147

  5. Taxonomically significant color reactions of Brevibacterium linens.

    PubMed

    GRECZ, N; DACK, G M

    1961-08-01

    Grecz, Nicholas (University of Chicago, Chicago, Ill.), and Gail M. Dack. Taxonomically significant color reactions of Brevibacterium linens. J. Bacteriol. 82:241-246. 1961.-Brevibacterium linens was observed to give characteristic color reactions with certain bases and acids. An intensive carmine-red color appeared immediately after addition of a drop of 5 n sodium hydroxide, 5 n potassium hydroxide, and saturated barium hydroxide. A light carmine-red was given by lithium hydroxide, and a light orange-red with a milky suspension of calcium hydroxide. No discernible color change was given with weak bases such as ammonium hydroxide, aniline, and pyridine.A characteristic salmon-pink color was produced when B. linens was rubbed with a glass rod in a drop of glacial acetic acid or filter paper; a brick-red color was produced with aniline under these conditions. With syrupy phosphoric acid a green color appeared within 3 to 4 min which turned blue after approximately 3 hr. The blue color was stable for several days. On the basis of these color reactions, B. linens could be distinguished from other microorganisms possessing yellow-orange pigmentation, i.e., Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus flavus, Micrococcus citreus, Mycobacterium phlei, Sarcina lutea. Therefore, these color changes may be used for the identification of B. linens. Original isolates of B. linens from cheese were tested by these spot reactions and all presumptive identifications could be subsequently confirmed by conventional methods. Blue and green colors appeared in all yellow-orange chromogens treated with sulfuric, perchloric, and hydrochloric acids and hence these colors were not specific for B. linens.

  6. On Statistical Testing.

    ERIC Educational Resources Information Center

    Huberty, Carl J.

    An approach to statistical testing, which combines Neyman-Pearson hypothesis testing and Fisher significance testing, is recommended. The use of P-values in this approach is discussed in some detail. The author also discusses some problems which are often found in introductory statistics textbooks. The problems involve the definitions of…

  7. 40 CFR 1508.27 - Significantly.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Significantly. 1508.27 Section 1508.27 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY TERMINOLOGY AND INDEX § 1508.27 Significantly. Significantly as used in NEPA requires considerations of both context and intensity: (a) Context. This...

  8. Creating Significant Learning Experiences across Disciplines

    ERIC Educational Resources Information Center

    Levine, Laura E.; Fallahi, Carolyn R.; Nicoll-Senft, Joan M.; Tessier, Jack T.; Watson, Cheryl L.; Wood, Rebecca M.

    2008-01-01

    The purpose of this study was to use Fink's (2003) taxonomy of significant learning to redesign courses and assess student learning. Significant improvements were found across the semester for students in the six courses, but there were differences in which taxa showed improvement in each course. The meta-analysis showed significant, positive…

  9. 23 CFR 630.1010 - Significant projects.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Significant projects. 630.1010 Section 630.1010 Highways... PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1010 Significant projects. (a) A significant project is one that, alone or in combination with other concurrent projects nearby is anticipated to...

  10. 48 CFR 2110.7003 - Significant events.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Significant events. 2110..., AND OTHER PURCHASE DESCRIPTIONS Contract Specifications 2110.7003 Significant events. The contractor is required to inform the contracting officer of all significant events....

  11. 48 CFR 2110.7003 - Significant events.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Significant events. 2110..., AND OTHER PURCHASE DESCRIPTIONS Contract Specifications 2110.7003 Significant events. The contractor is required to inform the contracting officer of all significant events....

  12. 48 CFR 2110.7003 - Significant events.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Significant events. 2110..., AND OTHER PURCHASE DESCRIPTIONS Contract Specifications 2110.7003 Significant events. The contractor is required to inform the contracting officer of all significant events....

  13. 48 CFR 2110.7003 - Significant events.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Significant events. 2110..., AND OTHER PURCHASE DESCRIPTIONS Contract Specifications 2110.7003 Significant events. The contractor is required to inform the contracting officer of all significant events....

  14. 48 CFR 2110.7003 - Significant events.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Significant events. 2110..., AND OTHER PURCHASE DESCRIPTIONS Contract Specifications 2110.7003 Significant events. The contractor is required to inform the contracting officer of all significant events....

  15. 23 CFR 630.1010 - Significant projects.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 23 Highways 1 2012-04-01 2012-04-01 false Significant projects. 630.1010 Section 630.1010 Highways... PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1010 Significant projects. (a) A significant project is one that, alone or in combination with other concurrent projects nearby is anticipated to...

  16. 23 CFR 630.1010 - Significant projects.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 false Significant projects. 630.1010 Section 630.1010 Highways... PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1010 Significant projects. (a) A significant project is one that, alone or in combination with other concurrent projects nearby is anticipated to...

  17. 23 CFR 630.1010 - Significant projects.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 23 Highways 1 2014-04-01 2014-04-01 false Significant projects. 630.1010 Section 630.1010 Highways... PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1010 Significant projects. (a) A significant project is one that, alone or in combination with other concurrent projects nearby is anticipated to...

  18. 23 CFR 630.1010 - Significant projects.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 23 Highways 1 2013-04-01 2013-04-01 false Significant projects. 630.1010 Section 630.1010 Highways... PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1010 Significant projects. (a) A significant project is one that, alone or in combination with other concurrent projects nearby is anticipated to...

  19. Thyroid Tests

    MedlinePlus

    ... the thyroid, a computerized tomography (CT) scan, or nuclear medicine tests, to diagnose and find the cause ... is having the scan for other health problems. Nuclear medicine tests. Nuclear medicine tests of the thyroid ...

  20. Laboratory Tests

    MedlinePlus

    Laboratory tests check a sample of your blood, urine, or body tissues. A technician or your doctor ... compare your results to results from previous tests. Laboratory tests are often part of a routine checkup ...

  1. Lipase Test

    MedlinePlus

    ... known as: LPS Formal name: Lipase Related tests: Amylase , Trypsin , Trypsinogen At a Glance Test Sample The ... lipase is most often used, along with an amylase test , to help diagnose and monitor acute pancreatitis . ...

  2. IQ testing

    MedlinePlus

    IQ (intelligence quotient) testing is a series of exams used to determine your general intelligence in relation ... Many IQ tests are used today. Whether they measure actual intelligence or simply certain abilities is controversial. IQ tests ...

  3. Test Madness

    ERIC Educational Resources Information Center

    Hedrick, Wanda B., Ed.

    2007-01-01

    There's accountability and then there's the testing craze an iatrogenic practice that undermines real learning. Hedrick documents the negative effects of testing, giving teachers another weapon in their arsenal against mindless preparation for high-stakes tests.

  4. Chlamydia Testing

    MedlinePlus

    ... of testing for chlamydia. NAAT is a molecular test that detects the genetic material ( DNA ) of Chlamydia trachomatis . It is generally more sensitive and specific than other chlamydia tests and can be performed on a vaginal swab ...

  5. Understanding Magnetic Anomalies and Their Significance.

    ERIC Educational Resources Information Center

    Shea, James H.

    1988-01-01

    Describes a laboratory exercise testing the Vine-Matthews-Morley hypothesis of plate tectonics. Includes 14 questions with explanations using graphs and charts. Provides a historical account of the current plate tectonic and magnetic anomaly theory. (MVL)

  6. Spectroscopic probes of vibrationally excited molecules at chemically significant energies

    SciTech Connect

    Rizzo, T.R.

    1993-12-01

    This project involves the application of multiple-resonance spectroscopic techniques for investigating energy transfer and dissociation dynamics of highly vibrationally excited molecules. Two major goals of this work are: (1) to provide information on potential energy surfaces of combustion related molecules at chemically significant energies, and (2) to test theoretical modes of unimolecular dissociation rates critically via quantum-state resolved measurements.

  7. Earth observations and photography experiment: Summary of significant results

    NASA Technical Reports Server (NTRS)

    El-Baz, F.

    1978-01-01

    Observation and photographic data from the Apollo Soyuz Test Project are analyzed. The discussion is structured according to the fields of investigation including: geology, desert studies, oceanography, hydrology, and meteorology. The data were obtained by: (1) visual observations of selected Earth features, (2) hand-held camera photography to document observations, and (3) stereo mapping photography of areas of significant scientific interest.

  8. 15 CFR 970.701 - Significant adverse environmental effects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES... effects of deep seabed mining which cumulatively during commercial recovery have the potential for significant effect. These three effects also occur during mining system tests that may be conducted under...

  9. Statistical Significance and Effect Size: Two Sides of a Coin.

    ERIC Educational Resources Information Center

    Fan, Xitao

    This paper suggests that statistical significance testing and effect size are two sides of the same coin; they complement each other, but do not substitute for one another. Good research practice requires that both should be taken into consideration to make sound quantitative decisions. A Monte Carlo simulation experiment was conducted, and a…

  10. 15 CFR 970.701 - Significant adverse environmental effects.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES... effects of deep seabed mining which cumulatively during commercial recovery have the potential for significant effect. These three effects also occur during mining system tests that may be conducted under...

  11. Complexity and significance in computer simulations of physiological systems.

    PubMed

    Kootsey, J M

    1987-06-01

    Complexity in a theoretical model may or may not be associated with a high level of arbitrariness, depending on how the model is constructed. In this paper I use examples from cardiac electrophysiology to illustrate two techniques for maintaining significance in complex simulations. First, the approaches of analysis and synthesis are compared as methods of constructing models of complex systems. When a model is constructed by synthesis of known principles, facts, and subunits, it may have any degree of complexity without losing significance; the same is not true for analysis models. Significance can also be maintained by assembling a limited model to test a specific hypothesis of mechanism.

  12. Testing Services

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Trace Laboratories is an independent testing laboratory specializing in testing printed circuit boards, automotive products and military hardware. Technical information from NASA Tech Briefs and two subsequent JPL Technical Support packages have assisted Trace in testing surface insulation resistance on printed circuit board materials. Testing time was reduced and customer service was improved because of Jet Propulsion Laboratory technical support packages.

  13. RPR test

    MedlinePlus

    ... more specific test for syphilis, such as FTA-ABS . The FTA-ABS test will help distinguish between syphilis and other ... Elsevier Saunders; 2015:chap 239. Read More FTA-ABS test VDRL test Review Date 9/10/2015 ...

  14. 40 CFR 1508.27 - Significantly.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... areas. (4) The degree to which the effects on the quality of the human environment are likely to be highly controversial. (5) The degree to which the possible effects on the human environment are highly... significant impact on the environment. Significance cannot be avoided by terming an action temporary or...

  15. 7 CFR 3015.93 - Significant developments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Significant developments. 3015.93 Section 3015.93... § 3015.93 Significant developments. Events may occur between the scheduled performance reporting dates... assistance needed to resolve the situation. (b) Favorable developments which enable meeting time...

  16. The Vernier Caliper and Significant Figures.

    ERIC Educational Resources Information Center

    Oberhofer, E. S.

    1985-01-01

    Misconceptions occur because the caliper is often read with the same significant figures as a meter stick; however, the precision of the vernier caliper is greater than the precision of a meter stick. Clarification of scale reading, precision of both tools, and significant figures are discussed. (JN)

  17. 32 CFR 651.39 - Significance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for evaluating regional economic impacts under NEPA. This system is mandated, as Army policy, for use... proposed action may or will result in significant impacts to the environment, an EIS is prepared to provide more comprehensive analyses and conclusions about the impacts. Significant impacts of...

  18. 40 CFR 1508.27 - Significantly.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., significance would usually depend upon the effects in the locale rather than in the world as a whole. Both short- and long-term effects are relevant. (b) Intensity. This refers to the severity of impact... both beneficial and adverse. A significant effect may exist even if the Federal agency believes that...

  19. 40 CFR 1508.27 - Significantly.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., significance would usually depend upon the effects in the locale rather than in the world as a whole. Both short- and long-term effects are relevant. (b) Intensity. This refers to the severity of impact... both beneficial and adverse. A significant effect may exist even if the Federal agency believes that...

  20. 32 CFR 651.39 - Significance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... existing pollution standards; cause water, air, noise, soil, or underground pollution; impair visibility for substantial periods; or cause irreparable harm to animal or plant life could be determined significant. Significant beneficial effects also occur and must be addressed, if applicable. (c) The...

  1. Significance of selected lineaments in Alabama

    NASA Technical Reports Server (NTRS)

    Drahovzal, J. A.; Neathery, T. L.; Wielchowsky, C. C.

    1974-01-01

    Four lineaments in the Alabama Appalachians that appear on ERTS-1 imagery have been geologically analysed. Two of the lineaments appear to have regional geologic significance, showing relationships to structural and stratigraphic frameworks, water and mineral resources, geophysical anomalies, and seismicity. The other two lineaments are of local geologic significance, but, nevertheless, have important environmental implications.

  2. 32 CFR 651.39 - Significance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Significance. 651.39 Section 651.39 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Environmental Assessment § 651.39 Significance. (a) If...

  3. 32 CFR 651.39 - Significance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Significance. 651.39 Section 651.39 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Environmental Assessment § 651.39 Significance. (a) If...

  4. 32 CFR 651.39 - Significance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Significance. 651.39 Section 651.39 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) Environmental Assessment § 651.39 Significance. (a) If...

  5. Evolution of the Significant Figure Rules

    ERIC Educational Resources Information Center

    Carter, Ashley R.

    2013-01-01

    Today, almost all introductory physics textbooks include standardized "rules" on how to find the number of significant figures in a calculated value. And yet, 30 years ago these rules were almost nonexistent. Why have we increased the role of significant figures in introductory classes, and should we continue this trend? A look back at…

  6. Composite Testing

    DTIC Science & Technology

    2007-01-01

    Impact Test Matrix for Each Team Impact Tests Qty. Reqd. Per Team Dimensions Steel- GFRP Hybrid Specimen 3 40” x 12” GFRP Control...5: Tension Test Specimen Details Table 2: Tension Test Matrix for Each Team Tension Tests Qty. Reqd. Per Team Dimensions Steel- GFRP Hybrid...Specimen 6 12” L x 1-2” W GFRP Control Specimen 3 12” L x 1-2” W Numerical Modelling A detailed numerical model

  7. Quantifying edge significance on maintaining global connectivity

    PubMed Central

    Qian, Yuhua; Li, Yebin; Zhang, Min; Ma, Guoshuai; Lu, Furong

    2017-01-01

    Global connectivity is a quite important issue for networks. The failures of some key edges may lead to breakdown of the whole system. How to find them will provide a better understanding on system robustness. Based on topological information, we propose an approach named LE (link entropy) to quantify the edge significance on maintaining global connectivity. Then we compare the LE with the other six acknowledged indices on the edge significance: the edge betweenness centrality, degree product, bridgeness, diffusion importance, topological overlap and k-path edge centrality. Experimental results show that the LE approach outperforms in quantifying edge significance on maintaining global connectivity. PMID:28349923

  8. SRS Process Facility Significance Fire Frequency

    SciTech Connect

    Sarrack, A.G.

    1995-10-01

    This report documents the method and assumptions of a study performed to determine a site generic process facility significant fire initiator frequency and explains the proper way this value should be used.

  9. Statistical significance of the gallium anomaly

    SciTech Connect

    Giunti, Carlo; Laveder, Marco

    2011-06-15

    We calculate the statistical significance of the anomalous deficit of electron neutrinos measured in the radioactive source experiments of the GALLEX and SAGE solar neutrino detectors, taking into account the uncertainty of the detection cross section. We found that the statistical significance of the anomaly is {approx}3.0{sigma}. A fit of the data in terms of neutrino oscillations favors at {approx}2.7{sigma} short-baseline electron neutrino disappearance with respect to the null hypothesis of no oscillations.

  10. Surface wettability plays a significant role in gecko adhesion underwater.

    PubMed

    Stark, Alyssa Y; Badge, Ila; Wucinich, Nicholas A; Sullivan, Timothy W; Niewiarowski, Peter H; Dhinojwala, Ali

    2013-04-16

    Although we now have thousands of studies focused on the nano-, micro-, and whole-animal mechanics of gecko adhesion on clean, dry substrates, we know relatively little about the effects of water on gecko adhesion. For many gecko species, however, rainfall frequently wets the natural surfaces they navigate. In an effort to begin closing this gap, we tested the adhesion of geckos on submerged substrates that vary in their wettability. When tested on a wet hydrophilic surface, geckos produced a significantly lower shear adhesive force (5.4 ± 1.33 N) compared with a dry hydrophilic surface (17.1 ± 3.93 N). In tests on an intermediate wetting surface and a hydrophobic surface, we found no difference in shear adhesion between dry and wet contact. Finally, in tests on polytetrafluoroethylene (PTFE), we found that geckos clung significantly better to wet PTFE (8.0 ± 1.09 N) than dry PTFE (1.6 ± 0.66 N). To help explain our results, we developed models based on thermodynamic theory of adhesion for contacting surfaces in different media and found that we can predict the ratio of shear adhesion in water to that in air. Our findings provide insight into how geckos may function in wet environments and also have significant implications for the development of a synthetic gecko mimic that retains adhesion in water.

  11. Surface wettability plays a significant role in gecko adhesion underwater

    PubMed Central

    Stark, Alyssa Y.; Badge, Ila; Wucinich, Nicholas A.; Sullivan, Timothy W.; Niewiarowski, Peter H.; Dhinojwala, Ali

    2013-01-01

    Although we now have thousands of studies focused on the nano-, micro-, and whole-animal mechanics of gecko adhesion on clean, dry substrates, we know relatively little about the effects of water on gecko adhesion. For many gecko species, however, rainfall frequently wets the natural surfaces they navigate. In an effort to begin closing this gap, we tested the adhesion of geckos on submerged substrates that vary in their wettability. When tested on a wet hydrophilic surface, geckos produced a significantly lower shear adhesive force (5.4 ± 1.33 N) compared with a dry hydrophilic surface (17.1 ± 3.93 N). In tests on an intermediate wetting surface and a hydrophobic surface, we found no difference in shear adhesion between dry and wet contact. Finally, in tests on polytetrafluoroethylene (PTFE), we found that geckos clung significantly better to wet PTFE (8.0 ± 1.09 N) than dry PTFE (1.6 ± 0.66 N). To help explain our results, we developed models based on thermodynamic theory of adhesion for contacting surfaces in different media and found that we can predict the ratio of shear adhesion in water to that in air. Our findings provide insight into how geckos may function in wet environments and also have significant implications for the development of a synthetic gecko mimic that retains adhesion in water. PMID:23576727

  12. Evolution of the Significant Figure Rules

    NASA Astrophysics Data System (ADS)

    Carter, Ashley R.

    2013-09-01

    Today, almost all introductory physics textbooks include standardized "rules" on how to find the number of significant figures in a calculated value. And yet, 30 years ago these rules were almost nonexistent. Whyhave we increased the role of significant figures in introductory classes, and should we continue this trend? A look back at the evolution of significant figures over the last 300 years, from Newton to Millikan to modern authors, sheds some light on their purpose moving forward. While there is much discussion for and against their use, especially in chemistry, a review of earlier versions of the rules suggests that we have lost some items of value, most notably, a significant figure rule for angles. In addition, we have lost the emphasis that the significant figure rules were designed to calculate an approximate (not exact) precision. Now that the significant figure rules are ingrained into our introductory physics sequence, we would be wise to reiterate that these are just general "rules of thumb."

  13. The Real World Significance of Performance Prediction

    ERIC Educational Resources Information Center

    Pardos, Zachary A.; Wang, Qing Yang; Trivedi, Shubhendu

    2012-01-01

    In recent years, the educational data mining and user modeling communities have been aggressively introducing models for predicting student performance on external measures such as standardized tests as well as within-tutor performance. While these models have brought statistically reliable improvement to performance prediction, the real world…

  14. Radon Testing in Schools.

    ERIC Educational Resources Information Center

    Wheeler, Robert

    1989-01-01

    Schools may be a significant source of radon exposure for children and staff. Describes radon detection kits and technologies, when to use them, and what action to take given the results of a radon test. (MLF)

  15. LDL Particle Testing

    MedlinePlus

    ... assessing cardiac risk in people who have a personal or family history of heart disease at a young age, especially if their total cholesterol and LDL cholesterol (LDL-C) values are not significantly elevated. LDL subfraction testing is ...

  16. Langley test highlights, 1981

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Significant aircraft tests which were performed are highlighted. The broad range of the research and technology activities. The conributions of this work toward maintaining United States leadership in aeronautics and space research are illustrated.

  17. The allergenic significance of certain fungi rarely reported as allergens.

    PubMed

    Giannini, E H; Northey, W T; Leathers, C R

    1975-12-01

    The allergenic significance of seven different species of fungi was investigated. Included were Chlorophyllum molybdites, Podaxis pistillaris, Stemonitis ferruginea, Lycogala epidendrum, Fuligo septica, Ustilago maydis and Puccinia cynodontis. All of these fungi have wide distribution patterns and aerially disseminated spores but, because of their unique growth characteristics, are usually not reported in atmospheric fungal surveys. Seventy-eight patients were treated for dermal sensitivity to extracts of the organisms after the spores were extracted in 50% glycerinated Coca's solution. The results represent a six-month test period. Forty-four patients, representing 56% of the total number tested, demonstrated dermal reactivity toward one or more of the extracts.

  18. Pregnancy test

    MedlinePlus

    ... eds. Henry's Clinical Diagnosis and Management by Laboratory Methods . 22nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 25. Read More Ectopic pregnancy HCG blood test - qualitative HCG blood test - quantitative HCG in urine Miscarriage ...

  19. Prenatal Tests

    MedlinePlus

    ... may recommend you have an invasive test, like amniocentesis , to confirm the results. Chorionic villus sampling (also ... done at 15 to 22 weeks of pregnancy. Amniocentesis (also called amnio). Tests the amniotic fluid from ...

  20. Procalcitonin Test

    MedlinePlus

    ... Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & ... Complete Blood Count , Blood Culture , CSF Analysis All content on Lab Tests Online ...

  1. HPV Test

    MedlinePlus

    ... test for wider range of HPV types. 2009 Mar 13. US Food and Drug Administration. Available online ... approves two DNA tests to detect HPV. 2009 Mar 17. Infectious Disease News. Available online at http:// ...

  2. Potassium test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003484.htm Potassium test To use the sharing features on this ... enable JavaScript. This test measures the amount of potassium in the fluid portion (serum) of the blood. ...

  3. Kidney Tests

    MedlinePlus

    ... taking out waste products and making urine. Kidney tests check to see how well your kidneys are working. They include blood, urine, and imaging tests. Early kidney disease usually does not have signs ...

  4. Urodynamic Testing

    MedlinePlus

    ... the ability or inability to stop the urine flow in midstream. For precise measurements, imaging equipment takes pictures of the bladder filling ... postvoid residual measurement cystometric test leak point pressure measurement pressure flow ... urodynamic tests Uroflowmetry Uroflowmetry is ...

  5. Pertussis Tests

    MedlinePlus

    ... as: Whooping Cough Tests Formal name: Bordetella pertussis Culture; Bordetella pertussis by PCR; Bordetella pertussis Antibodies (IgA, ... outbreak, at least one case be confirmed using culture. Culture – this test was the "gold standard" for ...

  6. Syphilis Test

    MedlinePlus

    ... been developed, making them convenient for screening purposes. Direct detection of bacteria —these tests are less commonly ... highly sensitive; can be used to exclude neurosyphilis. Direct detection tests (much less common): Microscopic Exam, Darkfield ...

  7. Seismic testing

    SciTech Connect

    Knott, S.

    1981-10-01

    Electric Power Research Institute (EPRI) research programs in seismic testing to improve earthquake design guidelines lowers the safety-design costs of nuclear power plants. Explosive tests that simulate earthquakes help to determine how structures respond to ground motion and how these are related to soil and geologic conditions at a specific site. Explosive tests develop data for simulation using several computer codes. Photographs illustrate testing techniques. 6 references. (DCK)

  8. Meaning reconstruction in bereavement: sense and significance.

    PubMed

    Hibberd, Rachel

    2013-08-01

    Recently there has been growing empirical and theoretical attention to the role of meaning in grief along with increased recognition of the need for more sophisticated definitions of meaning. The present article highlights philosophical issues inherent in the study of meaning and grief reviews the place of meaning in current theories of grief and provides a brief overview of the ways that meaning has been operationalized by grief researchers, including sense-making, benefit finding, identity change, and purpose in life. It is argued that, in our focus on the ways mourners make sense of loss, we have neglected an important aspect of meaning: life significance. Life significance is the felt perception that some aspect of one's life experience "matters." The construct is explored as a potentially important outcome of bereavement; mourners may lose life significance along with their lost loved one, or they may develop new avenues to life significance as they confront mortality and rebuild shattered worldviews. Related literature, such as appreciation of life as a facet of posttraumatic growth, is surveyed for clues as to the role of life significance in grief. Suggestions for future study are offered.

  9. Significance of Lead Residues in Mallard Tissues

    USGS Publications Warehouse

    Longcore, J.R.; Locke, L.N.; Bagley, George E.; Andrews, R.

    1974-01-01

    Tissues of adult, lead-dosed mallards that either died or were sacrificed were analyzed for lead. Lead levels in brains, tibiae, and breast muscle of ducks that died and in tibiae of ducks that were sacrificed increased significantly from dosage until death. Lead in the heart, lung, and blood from sacrificed ducks decreased significantly from dosage until death. Lead concentrations in tissues from ducks in the two groups were not significantly different except for the liver, kidney, and lung. Average lead levels in the livers and kidneys of ducks that died were significantly higher than those in ducks that were sacrificed. The mean concentration of lead in the lungs of the ducks sacrificed was significantly higher than the mean level in the lungs of ducks that died. Measurements of the lead concentrations in this study, when compared with lead levels reported in the literature for avian and non-avian species, showed that arbitrary diagnostic levels indicating lead poisoning could be set. In mallard ducks, lead levels exceeding 3 ppm in the brain, 6 to 20 ppm in the kidney or liver, or 10 ppm in clotted blood from the heart indicated acute exposure to lead.

  10. Tested Demonstrations.

    ERIC Educational Resources Information Center

    Gilbert, George L., Ed.

    1988-01-01

    Describes three flame test demonstrations including "Student-Presented Demonstrations on the Colors of Transition Metal Complexes,""A Flame Test Demonstration Device," and "Vivid Flame Tests." Preparation and procedures are discussed. Included in the first demonstration is an evaluation scheme for grading student…

  11. Teacher Testing.

    ERIC Educational Resources Information Center

    Dunn, Judy; And Others

    1987-01-01

    A one-page introduction is followed by summaries of articles and documents on teacher competency testing. George F. Madaus argues that, although tests serve some useful functions, treating them as a major mechanism for reforming education is questionable. Peter A. Garcia examines the negative impact of testing on minority teachers and minorities…

  12. Significance of autobiographical episodes and spacing effects in incidental memory.

    PubMed

    Toyota, Hiroshi

    2013-10-01

    Participants were presented with target words on two occasions, and were asked each time to generate a memory of a past episode associated with the targets. Participants were also instructed to rate the importance (significance elaboration) or pleasantness of the pisode (pleasantness elaboration) in an orienting task, followed by an unexpect d recall test. Significance elaboration led to better recall than pleasantness elaboration, but only in the spaced presentation. The spaced presentation led to better tree recall than massed presentation with significance elaboration, but the difference between the two types of presentation was not observed with pleasantness elaboration. These results suggest that the significance of an episode is more critical than the pleasantness of an episode in determining the effectiveness of autobiographical elaboration in facilitating recall.

  13. Developmental Changes in Adolescents' Olfactory Performance and Significance of Olfaction

    PubMed Central

    Klötze, Paula; Gerber, Friederike; Croy, Ilona; Hummel, Thomas

    2016-01-01

    Aim of the current work was to examine developmental changes in adolescents’ olfactory performance and personal significance of olfaction. In the first study olfactory identification abilities of 76 participants (31 males and 45 females aged between 10 and 18 years; M = 13.8, SD = 2.3) was evaluated with the Sniffin Stick identification test, presented in a cued and in an uncued manner. Verbal fluency was additionally examined for control purpose. In the second study 131 participants (46 males and 85 females aged between 10 and 18 years; (M = 14.4, SD = 2.2) filled in the importance of olfaction questionnaire. Odor identification abilities increased significantly with age and were significantly higher in girls as compared to boys. These effects were especially pronounced in the uncued task and partly related to verbal fluency. In line, the personal significance of olfaction increased with age and was generally higher among female compared to male participants. PMID:27332887

  14. Birthmarks of medical significance in the neonate.

    PubMed

    Benjamin, Latanya T

    2013-02-01

    Birthmarks are commonplace and most pose no significant detriment to health. It is usual for some 'birthmarks' to manifest within the first weeks to months of life and are not necessarily seen at birth. This is attributed in large part to the maturation of neonatal skin and the deepening of skin color over time. With time, increased pigment production in the skin by melanocytes eventually highlight the differences between normal and abnormal hypopigmented and hyperpigmented anomalies of the skin. Birthmarks can be seen as an isolated skin condition or serve as an important diagnostic aid for other more significant disorders. This review details four of the most common birthmarks regularly encountered in the neonatal period by perinatologists, obstetricians and pediatricians. This review emphasizes their medical significance and highlights any associated underlying systemic disease or genetic syndrome.

  15. Systematic identification of statistically significant network measures

    NASA Astrophysics Data System (ADS)

    Ziv, Etay; Koytcheff, Robin; Middendorf, Manuel; Wiggins, Chris

    2005-01-01

    We present a graph embedding space (i.e., a set of measures on graphs) for performing statistical analyses of networks. Key improvements over existing approaches include discovery of “motif hubs” (multiple overlapping significant subgraphs), computational efficiency relative to subgraph census, and flexibility (the method is easily generalizable to weighted and signed graphs). The embedding space is based on scalars, functionals of the adjacency matrix representing the network. Scalars are global, involving all nodes; although they can be related to subgraph enumeration, there is not a one-to-one mapping between scalars and subgraphs. Improvements in network randomization and significance testing—we learn the distribution rather than assuming Gaussianity—are also presented. The resulting algorithm establishes a systematic approach to the identification of the most significant scalars and suggests machine-learning techniques for network classification.

  16. The clinical significance of command hallucinations.

    PubMed

    Hellerstein, D; Frosch, W; Koenigsberg, H W

    1987-02-01

    Patients with command hallucinations (voices ordering particular acts, often violent or destructive ones) are commonly assumed to be at high risk for dangerous behavior. The authors reviewed 789 consecutive inpatient admissions. Of 151 patients with auditory hallucinations, 58 (38.4%) heard commands. The presence of auditory hallucinations was significantly associated with diagnosis, demographic variables, and use of maximal observation and seclusion. However, patients with command hallucinations were not significantly different from patients without commands on demographic and behavioral variables, including suicidal ideation or behavior and assaultiveness. These findings suggest that command hallucinations alone may not imply greater risk for acute, life-threatening behavior.

  17. Analytical testing

    NASA Technical Reports Server (NTRS)

    Flannelly, W. G.; Fabunmi, J. A.; Nagy, E. J.

    1981-01-01

    Analytical methods for combining flight acceleration and strain data with shake test mobility data to predict the effects of structural changes on flight vibrations and strains are presented. This integration of structural dynamic analysis with flight performance is referred to as analytical testing. The objective of this methodology is to analytically estimate the results of flight testing contemplated structural changes with minimum flying and change trials. The category of changes to the aircraft includes mass, stiffness, absorbers, isolators, and active suppressors. Examples of applying the analytical testing methodology using flight test and shake test data measured on an AH-1G helicopter are included. The techniques and procedures for vibration testing and modal analysis are also described.

  18. Scope and Significance of Eating Disorders.

    ERIC Educational Resources Information Center

    Mitchell, James E.; Eckert, Elke D.

    1987-01-01

    Describes the increasing prevalence of anorexia nervosa and bulimia in many industrialized societies, and their association with significant morbidity and mortality. Discusses the genetic risks for the development of anorexia nervosa, and treatment strategies. Of these, pharmacotherapy and psychotherapy, particularly those incorporating…

  19. The Philosophical Significance of Universal Grammar

    ERIC Educational Resources Information Center

    Hinzen, Wolfram

    2012-01-01

    Throughout its long history, the project of a science of grammar has always been an inherently philosophical one, in which the study of grammar was taken to have special epistemological significance. I ask why 20th and 21st century inquiry into Universal Grammar (UG) has largely lost this dimension, a fact that I argue is partially responsible for…

  20. 32 CFR 1290.6 - Significant changes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Significant changes. 1290.6 Section 1290.6 National Defense Other Regulations Relating to National Defense DEFENSE LOGISTICS AGENCY MISCELLANEOUS PREPARING AND PROCESSING MINOR OFFENSES AND VIOLATION NOTICES REFERRED TO U.S. DISTRICT COURTS §...

  1. 32 CFR 1280.3 - Significant changes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Significant changes. 1280.3 Section 1280.3 National Defense Other Regulations Relating to National Defense DEFENSE LOGISTICS AGENCY MISCELLANEOUS INVESTIGATING AND PROCESSING CERTAIN NONCONTRACTUAL CLAIMS AND REPORTING RELATED LITIGATION § 1280.3...

  2. Significant Workplace Change: Perspectives of Survivors

    ERIC Educational Resources Information Center

    Kohut, Ann Marie

    2010-01-01

    The ever-increasing pace of workplace change is well documented in the literature, yet little is known about how an individual adapts to significant change in the workplace. Continuous learning is key to successful adaptation; however, are employees' adaptation to change influenced by their approaches to learning? The purpose of this study was to…

  3. Significance of oxygen transport through aquaporins

    PubMed Central

    Zwiazek, Janusz J.; Xu, Hao; Tan, Xiangfeng; Navarro-Ródenas, Alfonso; Morte, Asunción

    2017-01-01

    Aquaporins are membrane integral proteins responsible for the transmembrane transport of water and other small neutral molecules. Despite their well-acknowledged importance in water transport, their significance in gas transport processes remains unclear. Growing evidence points to the involvement of plant aquaporins in CO2 delivery for photosynthesis. The role of these channel proteins in the transport of O2 and other gases may also be more important than previously envisioned. In this study, we examined O2 permeability of various human, plant, and fungal aquaporins by co-expressing heterologous aquaporin and myoglobin in yeast. Two of the most promising O2-transporters (Homo sapiens AQP1 and Nicotiana tabacum PIP1;3) were confirmed to facilitate O2 transport in the spectrophotometric assay using yeast protoplasts. The over-expression of NtPIP1;3 in yeasts significantly increased their O2 uptake rates in suspension culture. In N. tabacum roots subjected to hypoxic hydroponic conditions, the transcript levels of the O2-transporting aquaporin NtPIP1;3 significantly increased after the seven-day hypoxia treatment, which was accompanied by the increase of ATP levels in the apical root segments. Our results suggest that the functional significance of aquaporin-mediated O2 transport and the possibility of controlling the rate of transmembrane O2 transport should be further explored. PMID:28079178

  4. 40 CFR 1508.27 - Significantly.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... species or its habitat that has been determined to be critical under the Endangered Species Act of 1973... (human, national), the affected region, the affected interests, and the locality. Significance varies... areas. (4) The degree to which the effects on the quality of the human environment are likely to...

  5. The Preconscious: Locus for Significant Written Compositions.

    ERIC Educational Resources Information Center

    Alley, Alvin D.

    1979-01-01

    The author suggests that the preconscious is the true locus of significant prose because of its greater amount of freedom to gather, compare, and rearrange ideas, and that the ultimate challenge to teachers of composition is to give freedom to their students' preconscious processes. (KC)

  6. Significance of Literature in Foreign Language Teaching

    ERIC Educational Resources Information Center

    Babaee, Ruzbeh; Yahya, Wan Roselezam Bt Wan

    2014-01-01

    This research aims to consider literature as a significant tool for teaching fundamental language skills including speaking, listening, reading and writing. Reasons for the use of literature in language classrooms and major factors for choosing appropriate kinds of literary texts in such classes should be highlighted in order to make readers aware…

  7. The Earth's Gravity and Its Geological Significance.

    ERIC Educational Resources Information Center

    Cook, A. H.

    1980-01-01

    Discussed is the earth's gravity and its geological significance. Variations of gravity around the earth can be produced by a great variety of possible distributions of density within the earth. Topics discussed include isostasy, local structures, geological exploration, change of gravity in time, and gravity on the moon and planets. (DS)

  8. Social significance of community structure: Statistical view

    NASA Astrophysics Data System (ADS)

    Li, Hui-Jia; Daniels, Jasmine J.

    2015-01-01

    Community structure analysis is a powerful tool for social networks that can simplify their topological and functional analysis considerably. However, since community detection methods have random factors and real social networks obtained from complex systems always contain error edges, evaluating the significance of a partitioned community structure is an urgent and important question. In this paper, integrating the specific characteristics of real society, we present a framework to analyze the significance of a social community. The dynamics of social interactions are modeled by identifying social leaders and corresponding hierarchical structures. Instead of a direct comparison with the average outcome of a random model, we compute the similarity of a given node with the leader by the number of common neighbors. To determine the membership vector, an efficient community detection algorithm is proposed based on the position of the nodes and their corresponding leaders. Then, using a log-likelihood score, the tightness of the community can be derived. Based on the distribution of community tightness, we establish a connection between p -value theory and network analysis, and then we obtain a significance measure of statistical form . Finally, the framework is applied to both benchmark networks and real social networks. Experimental results show that our work can be used in many fields, such as determining the optimal number of communities, analyzing the social significance of a given community, comparing the performance among various algorithms, etc.

  9. Social significance of community structure: statistical view.

    PubMed

    Li, Hui-Jia; Daniels, Jasmine J

    2015-01-01

    Community structure analysis is a powerful tool for social networks that can simplify their topological and functional analysis considerably. However, since community detection methods have random factors and real social networks obtained from complex systems always contain error edges, evaluating the significance of a partitioned community structure is an urgent and important question. In this paper, integrating the specific characteristics of real society, we present a framework to analyze the significance of a social community. The dynamics of social interactions are modeled by identifying social leaders and corresponding hierarchical structures. Instead of a direct comparison with the average outcome of a random model, we compute the similarity of a given node with the leader by the number of common neighbors. To determine the membership vector, an efficient community detection algorithm is proposed based on the position of the nodes and their corresponding leaders. Then, using a log-likelihood score, the tightness of the community can be derived. Based on the distribution of community tightness, we establish a connection between p-value theory and network analysis, and then we obtain a significance measure of statistical form . Finally, the framework is applied to both benchmark networks and real social networks. Experimental results show that our work can be used in many fields, such as determining the optimal number of communities, analyzing the social significance of a given community, comparing the performance among various algorithms, etc.

  10. The Educational Significance of Canada's Constitution.

    ERIC Educational Resources Information Center

    Wells, Allen R.

    1985-01-01

    Traces the historical relationship of Canada's educational system to its constitution. Concludes that the significance of the patriation of Canada's constitution for education includes strengthening a drive for bilingual education, promoting equality of opportunity, and continuing education as a provincial concern while unifying, nationally, the…

  11. Significance of oxygen transport through aquaporins.

    PubMed

    Zwiazek, Janusz J; Xu, Hao; Tan, Xiangfeng; Navarro-Ródenas, Alfonso; Morte, Asunción

    2017-01-12

    Aquaporins are membrane integral proteins responsible for the transmembrane transport of water and other small neutral molecules. Despite their well-acknowledged importance in water transport, their significance in gas transport processes remains unclear. Growing evidence points to the involvement of plant aquaporins in CO2 delivery for photosynthesis. The role of these channel proteins in the transport of O2 and other gases may also be more important than previously envisioned. In this study, we examined O2 permeability of various human, plant, and fungal aquaporins by co-expressing heterologous aquaporin and myoglobin in yeast. Two of the most promising O2-transporters (Homo sapiens AQP1 and Nicotiana tabacum PIP1;3) were confirmed to facilitate O2 transport in the spectrophotometric assay using yeast protoplasts. The over-expression of NtPIP1;3 in yeasts significantly increased their O2 uptake rates in suspension culture. In N. tabacum roots subjected to hypoxic hydroponic conditions, the transcript levels of the O2-transporting aquaporin NtPIP1;3 significantly increased after the seven-day hypoxia treatment, which was accompanied by the increase of ATP levels in the apical root segments. Our results suggest that the functional significance of aquaporin-mediated O2 transport and the possibility of controlling the rate of transmembrane O2 transport should be further explored.

  12. Shared services centers can drive significant savings.

    PubMed

    McDowell, Jim

    2011-06-01

    A study of more than 30 U.S. integrated delivery systems (IDSs) found that implementing effective shared services centers can drive significant cost savings in human resources, accounts payable, and procurement. Many IDSs have not adopted effective shared services strategies. Implementing administrative shared services involves low risk and a relatively low start-up investment.

  13. The Historical Significance of the Universal Declaration.

    ERIC Educational Resources Information Center

    Eide, Asbjorn

    1998-01-01

    Explains the historical significance of the Universal Declaration of Human Rights. Focuses on the initiative for the Declaration and its elaboration, the precursors to modern human rights, the foundation of the Declaration, the rights contained in the Universal Declaration, three modes of human rights analysis, and global governance and human…

  14. Bullying in Academe: Prevalent, Significant, and Incessant

    ERIC Educational Resources Information Center

    Cassell, Macgorine A.

    2011-01-01

    This paper examines the top-down perspective of bullying and mobbing of professors by analyzing why it is prevalent, significant, and incessant and then proposes a framework to produce a caring, respectful, and safe environment for professors to engage in their teaching, scholarship, and service. The author suggests that the failure of…

  15. Significant Literature by and about Native Americans.

    ERIC Educational Resources Information Center

    Willis, Cecilia A., Comp.; Travis, M. Eunice, Comp.

    Significant literature about Native Americans, some written by Native Americans, comprises this bibliography. Materials relevant to Native Americans found at Kansas State University are listed. Over 850 books, articles on microfiche, studies, documents, and publications arranged by subject categories are contained in this bibliography. The subject…

  16. Mycotoxins: significance to global economics and health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mycotoxins are fungal metabolites produced my micro-fungi (molds and mildews) that have significant impacts on global economics and health. Some of these metabolites are beneficial, but most are harmful and have been associated with well-known epidemics dating back to medieval times. The terms ‘myco...

  17. Replication of Significant Correlations in Small Samples

    ERIC Educational Resources Information Center

    Lemons, Christopher J.

    2009-01-01

    Researchers conducting studies involving individuals with exceptionalities are often prevented from involving large numbers of participants in their study samples. When this is the case, some say significant correlations are likely to replicate because the relation between two variables must be robust enough to be detected even with low…

  18. Determining the Statistical Significance of Relative Weights

    ERIC Educational Resources Information Center

    Tonidandel, Scott; LeBreton, James M.; Johnson, Jeff W.

    2009-01-01

    Relative weight analysis is a procedure for estimating the relative importance of correlated predictors in a regression equation. Because the sampling distribution of relative weights is unknown, researchers using relative weight analysis are unable to make judgments regarding the statistical significance of the relative weights. J. W. Johnson…

  19. 12 CFR 242.4 - Significant nonbank financial companies and significant bank holding companies.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 4 2014-01-01 2014-01-01 false Significant nonbank financial companies and significant bank holding companies. 242.4 Section 242.4 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED...-FRANK ACT (REGULATION PP) § 242.4 Significant nonbank financial companies and significant bank...

  20. The Effects of Test Difficulty Manipulation in Computerized Adaptive Testing and Self-Adapted Testing.

    ERIC Educational Resources Information Center

    Ponsoda, Vicente; Olea, Julio; Rodriguez, Maria Soledad; Revuelta, Javier

    1999-01-01

    Compared easy and difficult versions of self-adapted tests (SAT) and computerized adapted tests. No significant differences were found among the tests for estimated ability or posttest state anxiety in studies with 187 Spanish high school students, although other significant differences were found. Discusses implications for interpreting test…

  1. Significant determinants of mouse pain behaviour.

    PubMed

    Minett, Michael S; Eijkelkamp, Niels; Wood, John N

    2014-01-01

    Transgenic mouse behavioural analysis has furthered our understanding of the molecular and cellular mechanisms underlying damage sensing and pain. However, it is not unusual for conflicting data on the pain phenotypes of knockout mice to be generated by reputable groups. Here we focus on some technical aspects of measuring mouse pain behaviour that are often overlooked, which may help explain discrepancies in the pain literature. We examined touch perception using von Frey hairs and mechanical pain thresholds using the Randall-Selitto test. Thermal pain thresholds were measured using the Hargreaves apparatus and a thermal place preference test. Sodium channel Nav1.7 knockout mice show a mechanical deficit in the hairy skin, but not the paw, whilst shaving the abdominal hair abolished this phenotype. Nav1.7, Nav1.8 and Nav1.9 knockout mice show deficits in noxious mechanosensation in the tail, but not the paw. TRPA1 knockout mice, however, have a loss of noxious mechanosensation in the paw but not the tail. Studies of heat and cold sensitivity also show variability depending on the intensity of the stimulus. Deleting Nav1.7, Nav1.8 or Nav1.9 in Nav1.8-positive sensory neurons attenuates responses to slow noxious heat ramps, whilst responses to fast noxious heat ramps are only reduced when Nav1.7 is lost in large diameter sensory neurons. Deleting Nav1.7 from all sensory neurons attenuates responses to noxious cooling but not extreme cold. Finally, circadian rhythms dramatically influence behavioural outcome measures such as von Frey responses, which change by 80% over the day. These observations demonstrate that fully characterising the phenotype of a transgenic mouse strain requires a range of behavioural pain models. Failure to conduct behavioural tests at different anatomical locations, stimulus intensities, and at different points in the circadian cycle may lead to a pain behavioural phenotype being misinterpreted, or missed altogether.

  2. Understanding cultural significance, the edible mushrooms case

    PubMed Central

    Garibay-Orijel, Roberto; Caballero, Javier; Estrada-Torres, Arturo; Cifuentes, Joaquín

    2007-01-01

    Background Cultural significance is a keystone in quantitative ethnobiology, which offers the possibility to make inferences about traditional nomenclature systems, use, appropriation and valuing of natural resources. In the present work, using as model the traditional mycological knowledge of Zapotecs from Oaxaca, Mexico, we analyze the cultural significance of wild edible resources. Methods In 2003 we applied 95 questionnaires to a random sample of informants. With this data we integrated the Edible Mushroom Cultural Significance Index. This index included eight variables: frequency of mention, perceived abundance, use frequency, taste, multifunctional food use, knowledge transmission, health and economy. Data were analyzed in an inductive perspective using ordination and grouping techniques to reveal the behavior of species in a cultural multivariate dimension. Results In each variable the species had different conducts. Cantharellus cibarius s.l. was the species with most frequency of mention. Pleurotus sp. had the highest perceived abundance. C. cibarius s.l. was the most frequently consumed species. Gomphus clavatus was the most palatable species and also ranked highest in the multifunctional food index. Cortinarius secc.Malacii sp. had the highest traditional importance. Only Tricholoma magnivelare was identified as a health enhancer. It also had the most economic importance. According to the compound index, C. cibarius s.l., the Amanita caesarea complex, Ramaria spp. and Neolentinus lepideus were the mushrooms with highest cultural significance. Multivariate analysis showed that interviewees identify three main groups of mushrooms: species with high traditional values, frequent consumption and known by the majority; species that are less known, infrequently consumed and without salient characteristics; and species with low traditional values, with high economic value and health enhancers. Conclusion The compound index divided the cultural significance into

  3. Cognitive Impairment in Individuals with Insomnia: Clinical Significance and Correlates

    PubMed Central

    Fortier-Brochu, Émilie; Morin, Charles M.

    2014-01-01

    Study Objectives: The aims of this study were to (1) investigate the nature of cognitive impairment in individuals with insomnia, (2) document their clinical significance, (3) examine their correlates, and (4) explore differences among individuals with insomnia with and without cognitive complaints. Design: Participants underwent 3 consecutive nights of polysomnography. On the morning following the third night, they completed a battery of questionnaires and neuropsychological tests. Participants: The sample included 25 adults with primary insomnia (mean age: 44.4 ± 11.5 y, 56% women) and 16 controls (mean age: 42.8 ± 12.9 y, 50% women) matched for sex, age, and education. Intervention: N/A. Measurement and Results: Participants completed neuropsychological tests covering attention, memory, working memory, and executive functions, as well as questionnaires assessing the subjective perception of performance, depression, anxiety, fatigue, sleepiness, and hyperarousal. There were significant group differences for the attention and episodic memory domains. Clinically significant deficits were more frequent in the insomnia group. Within the insomnia group, individuals with cognitive complaints exhibited significantly poorer performance on a larger number of neuropsychological variables. All impaired aspects of performance were significantly associated with either subjective or objective sleep continuity, and some were also independently related to sleep microstructure (i.e., relative power for alpha frequencies) or selected psychological variables (i.e., beliefs or arousal). Conclusions: These findings suggest clinically significant alterations in attention and episodic memory in individuals with insomnia. Objective deficits were more pronounced and involved more aspects of performance in a subgroup of individuals with cognitive complaints. These deficits appear associated with sleep continuity, and may also be related to sleep microstructure and dysfunctional beliefs

  4. Respiratory neuroplasticity - Overview, significance and future directions.

    PubMed

    Fuller, David D; Mitchell, Gordon S

    2017-01-01

    Neuroplasticity is an important property of the neural system controlling breathing. However, our appreciation for its importance is still relatively new, and we have much to learn concerning different forms of plasticity, their underlying mechanisms, and their biological and clinical significance. In this brief review, we discuss several well-studied models of respiratory plasticity, including plasticity initiated by inactivity in the respiratory system, intermittent and sustained hypoxia, and traumatic injury to the spinal cord. Other aspects of respiratory plasticity are considered in other contributions to this special edition of Experimental Neurology on respiratory plasticity. Finally, we conclude with discussions concerning the biological and clinical significance of respiratory motor plasticity, and areas in need of future research effort.

  5. Significance of cocaine history in schizophrenia.

    PubMed

    Sevy, S; Kay, S R; Opler, L A; van Praag, H M

    1990-10-01

    Fifty-one schizophrenic inpatients were divided into two groups, those with and without history of cocaine use, and compared on historical, demographic, cognitive, and psychopathological measures. Patients with a cocaine history were found to be significantly more depressed, less socialized, and more impaired in conceptual encoding and verbal memory, while less disordered in attention. The two groups did not differ in severity of illness or positive and negative syndromes. There were also no differences in control variables such as age, gender, education, intelligence, premorbid adjustment, neuroleptic dose, onset and chronicity of illness, continuity of hospitalization, paranoid subtype, and psychiatric illness in the family. Cocaine history was associated with multiple illicit drug use, but for other substances there was no increased liability for depression or cognitive deficits. The results suggest that the clinical presentation in schizophrenia is significantly associated with prior cocaine experience.

  6. A 110-year perspective of significant tornadoes

    NASA Astrophysics Data System (ADS)

    Grazulis, Thomas P.

    A tornado documentation project began in 1980 as an effort to resolve differences between the two independently designed tornado data bases used by the Nuclear Regulatory Commission (NRC). One was established for the NRC at the University of Chicago (UC) by T. T. Fujita for the years 1916-1985. In addition, the NRC assisted the National Severe Storms Forecast Center (NSSFC) in adding F scale ratings to the existing NSSFC data base in Kansas City, from 1950 to the present. The final task of this effort (hereinafter called the project) was to locate and list all significant tornadoes from 1880 through 1989. Significant is defined here as all tornadoes doing confirmable F-2 or greater damage or causing a death.

  7. Childhood injury: significance and prevention strategies.

    PubMed

    Crawley, T

    1996-08-01

    Unintentional preventable injury is the number one killer of our children. Each year more children die of injuries than of all childhood diseases combined. It is important for nurses to understand the epidemiology and significance of childhood injury. This article discusses developmental and environmental factors that influence the child's probability of sustaining an unintentional injury and offers suggestions for client, family, and community injury prevention efforts for nurses.

  8. Significant Accomplishments in Science and Technology

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The proceedings of a symposium on significant accomplishments in science and technology are presented. The symposium was held at the Goddard Space Flight Center in December 1973. The subjects discussed are as follows: (1) cometary physics, (2) X-ray and gamma ray astronomy, (3) solar and terrestrial physics, (4) spacecraft technology, (5) Earth Resources Technology Satellite, (6) earth and ocean physics, (6) communications and navigation, (7) mission operations and data systems, and (8) networks systems and operations.

  9. Least significant qubit algorithm for quantum images

    NASA Astrophysics Data System (ADS)

    Sang, Jianzhi; Wang, Shen; Li, Qiong

    2016-11-01

    To study the feasibility of the classical image least significant bit (LSB) information hiding algorithm on quantum computer, a least significant qubit (LSQb) information hiding algorithm of quantum image is proposed. In this paper, we focus on a novel quantum representation for color digital images (NCQI). Firstly, by designing the three qubits comparator and unitary operators, the reasonability and feasibility of LSQb based on NCQI are presented. Then, the concrete LSQb information hiding algorithm is proposed, which can realize the aim of embedding the secret qubits into the least significant qubits of RGB channels of quantum cover image. Quantum circuit of the LSQb information hiding algorithm is also illustrated. Furthermore, the secrets extracting algorithm and circuit are illustrated through utilizing control-swap gates. The two merits of our algorithm are: (1) it is absolutely blind and (2) when extracting secret binary qubits, it does not need any quantum measurement operation or any other help from classical computer. Finally, simulation and comparative analysis show the performance of our algorithm.

  10. Reported Significant Observation (RSO) studies. Revision 1

    SciTech Connect

    Eicher, R.W.

    1992-12-01

    The Reported Significant Observation (RSO) study used in the field of safety is an information-gathering technique where employee-participants describe situations they have personally witnessed involving good and bad practices and safe and unsafe conditions. This information is useful in the risk assessment process because it focuses on hazards and thereby facilitates their elimination. However, RSO cannot be the only component in a risk assessment program. Used by the Air Force in their aviation psychology program and further developed by John C. Flanagan, RSO is more commonly known as the ``Critical Incident Technique.`` However, the words ``Critical`` and ``Incident`` had other connotations in nuclear safety, prompting early users within the Aerojet Nuclear Company to coin the more fitting title of ``Reported Significant Observations.`` The technique spread slowly in the safety field primarily because the majority of users were researchers interested in after-the-fact data, with application to everyday problems and behavioral factors. RSO was formally recognized as a significant hazard reduction tool during the development of the Management Oversight and Risk Tree (MORT) program for the US Atomic Energy Commission. The Department of Energy (DOE) has, in turn, adopted MORT for its system safety program, and this has resulted in RSO being a modern and viable technique for DOE contractor safety programs.

  11. Clinically significant drug interactions with atypical antipsychotics.

    PubMed

    Kennedy, William Klugh; Jann, Michael W; Kutscher, Eric C

    2013-12-01

    Atypical antipsychotics [also known as second-generation antipsychotics (SGAs)] have become a mainstay therapeutic treatment intervention for patients with schizophrenia, bipolar disorders and other psychotic conditions. These agents are commonly used with other medications--most notably, antidepressants and antiepileptic drugs. Drug interactions can take place by various pharmacokinetic, pharmacodynamic and pharmaceutical mechanisms. The pharmacokinetic profile of each SGA, especially with phase I and phase II metabolism, can allow for potentially significant drug interactions. Pharmacodynamic interactions arise when agents have comparable receptor site activity, which can lead to additive or competitive effects without alterations in measured plasma drug concentrations. Additionally, the role of drug transporters in drug interactions continues to evolve and may effect both pharmacokinetic and pharmacodynamic interactions. Pharmaceutical interactions occur when physical incompatibilities take place between agents prior to drug absorption. Approximate therapeutic plasma concentration ranges have been suggested for a number of SGAs. Drug interactions that markedly increase or decrease the concentrations of these agents beyond their ranges can lead to adverse events or diminished clinical efficacy. Most clinically significant drug interactions with SGAs occur via the cytochrome P450 (CYP) system. Many but not all drug interactions with SGAs are identified during drug discovery and pre-clinical development by employing a series of standardized in vitro and in vivo studies with known CYP inducers and inhibitors. Later therapeutic drug monitoring programmes, clinical studies and case reports offer methods to identify additional clinically significant drug interactions. Some commonly co-administered drugs with a significant potential for drug-drug interactions with selected SGAs include some SSRIs. Antiepileptic mood stabilizers such as carbamazepine and valproate, as

  12. Testing Relativity

    NASA Astrophysics Data System (ADS)

    Hentschel, Klaus

    in chapter 7 of this book, Klaus Hentschel first reviews Einstein's general attitude towards experiments, much more positive than generally believed, then reviews experimental tests of both special and general relativity, focussing on tests during Einstein's lifetime, incl. gravitational redshift, light deflection, perihelion motion. Among the non-standard tests, time-delay measurements, gyroscope experiments, the Nordtvedt effect, and gravitational waves are also discussed.

  13. Performance tests.

    PubMed Central

    Wetherell, A

    1996-01-01

    This paper discusses the use of psychological performance tests to assess the effects of environmental stressors. The large number and the variety of performance tests are illustrated, and the differences between performance tests and other psychological tests are described in terms of their design, construction, use, and purpose. The stressor emphasis is on the effects of drugs since that is where most performance tests have found their main application, although other stressors, e.g., fatigue, toxic chemicals, are mentioned where appropriate. Diazepam is used as an example. There is no particular performance emphasis since the tests are intended to have wide applicability. However, vehicle-driving performance is discussed because it has been the subject of a great deal of research and is probably one of the most important areas of application. Performance tests are discussed in terms of the four main underlying models--factor analysis, general information processing, multiple resource and strategy models, and processing-stage models--and in terms of their psychometric properties--sensitivity, reliability, and content, criterion, construct, and face validity. Some test taxonomies are presented. Standardization is also discussed with reference to the reaction time, mathematical processing, memory search, spatial processing, unstable tracking, verbal processing, and dual task tests used in the AGARD STRES battery. Some comments on measurement strengths and appropriate study designs and methods are included. PMID:9182033

  14. Rubella Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  15. Malnutrition Tests

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  16. RSV Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  17. PTH Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  18. Progesterone Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  19. Is It Really Possible to Test All Educationally Significant Achievements with High Levels of Reliability?

    ERIC Educational Resources Information Center

    Davis, Andrew

    2015-01-01

    PISA claims that it can extend its reach from its current core subjects of Reading, Science, Maths and problem-solving. Yet given the requirement for high levels of reliability for PISA, especially in the light of its current high stakes character, proposed widening of its subject coverage cannot embrace some important aspects of the social and…

  20. Testing Predictors of Instructional Practice in Elementary Science Education: The Significant Role of Accountability

    ERIC Educational Resources Information Center

    Hayes, Kathryn N.; Trexler, Cary J.

    2016-01-01

    Many resources have been committed to research on science teaching pedagogies, resulting in a robust understanding of best instructional practices. Yet, exposure to excellent science instruction in elementary school is haphazard at best and often inequitable. Although the research community has attended to the role of teacher traits, such as…

  1. A note on permutation tests of significance for multiple regression coefficients.

    PubMed

    Long, Michael A; Berry, Kenneth J; Mielke, Paul W

    2007-04-01

    In the vast majority of psychological research utilizing multiple regression analysis, asymptotic probability values are reported. This paper demonstrates that asymptotic estimates of standard errors provided by multiple regression are not always accurate. A resampling permutation procedure is used to estimate the standard errors. In some cases the results differ substantially from the traditional least squares regression estimates.

  2. Finding of No Significant Impact and Environmental Assessment for Flight Test to the Edge of Space

    DTIC Science & Technology

    2008-12-01

    Tech, Inc.,501 Soledad ,San Antonio,TX,78205 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) Dr...PERFORMING ORGANIZATION REPORT NUMBER Jim Knight Tetra Tech, Inc. 501 Soledad San Antonio, TX 78205 Jerry Haber ACTA Inc. 2790 Skypark

  3. Prevalence and clinical significance of painless ST segment depression during early postinfarction exercise testing

    SciTech Connect

    Gibson, R.S.; Beller, G.A.; Kaiser, D.L.

    1987-03-01

    In a recent study of 190 survivors of acute myocardial infarction, the authors sought to determine whether exercise-induced painless ST segments depression indicates residual myocardial ischemia, as defined by /sup 201/Tl scintigraphic criteria. 2 weeks after uncomplicated myocardial infarction, and whether quantitative /sup 201/Tl imaging enhances the prognostic value of such an exercise electrocardiographic response.

  4. The Quantitative-Qualitative Distinction and the Null Hypothesis Significance Testing Procedure

    ERIC Educational Resources Information Center

    Ratnesar, Nimal; Mackenzie, Jim

    2006-01-01

    Conventional discussion of research methodology contrast two approaches, the quantitative and the qualitative, presented as collectively exhaustive. But if qualitative is taken as the understanding of lifeworlds, the two approaches between them cover only a tiny fraction of research methodologies; and the quantitative, taken as the routine…

  5. Known occupational carcinogens and their significance.

    PubMed Central

    Ernst, P.; Thériault, G.

    1984-01-01

    Although rates of occupational cancer can be excessive in certain industries, less than 5% of all cancers seem attributable to exposure to carcinogens in the workplace. For example, workers in hard-rock mining and the woodworking industries are at increased risk; cigarette smoking has a synergistic effect. There is conclusive evidence of carcinogenicity for fewer than 20 substances, including asbestos, arsenic, chromium, nickel, cadmium, radon, several aromatic hydrocarbons and certain herbicides. Most of the hundreds of organic compounds known to be mutagenic in in-vitro tests have not been shown to be carcinogenic in epidemiologic studies. Both laboratory and epidemiologic approaches, however, can identify probable causes of cancer and permit the application of effective preventive measures. In addition, it is still possible for the alert individual clinician to make the initial discovery of an occupational hazard. PMID:6367918

  6. A procedure for identifying significant environmental aspects in sea ports.

    PubMed

    Darbra, R M; Ronza, A; Stojanovic, T A; Wooldridge, C; Casal, J

    2005-08-01

    A new methodology has been designed to identify and rank the significant environmental aspects in sea ports. The main objective of the Strategic Overview of Significant Environmental Aspects (SOSEA) is to help port managers to identify significant environmental aspects and to reinforce the awareness about them in order to prioritise work in environmental management. Developed in close collaboration with port environmental managers and tested in a set of ports, it is a user-friendly tool that can be applied in approximately half a working day. It is based on ISO 14001 vocabulary and requirements and it can be considered as the base for the implementation of any Environmental Management System for port communities.

  7. Prevention of Significant Deterioration Workshop Manual 1980

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  8. Boiling significantly promotes photodegradation of perfluorooctane sulfonate.

    PubMed

    Lyu, Xian-Jin; Li, Wen-Wei; Lam, Paul K S; Yu, Han-Qing

    2015-11-01

    The application of photochemical processes for perfluorooctane sulfonate (PFOS) degradation has been limited by a low treatment efficiency. This study reports a significant acceleration of PFOS photodegradation under boiling condition compared with the non-boiling control. The PFOS decomposition rate increased with the increasing boiling intensity, but declined at a higher hydronium level or under oxygenation. These results suggest that the boiling state of solution resulted in higher effective concentrations of reactants at the gas-liquid interface and enhanced the interfacial mass transfer, thereby accelerating the PFOS decomposition. This study broadens our knowledge of PFOS photodegradation process and may have implications for development of efficient photodegradation technologies.

  9. Significant warming of the Antarctic winter troposphere.

    PubMed

    Turner, J; Lachlan-Cope, T A; Colwell, S; Marshall, G J; Connolley, W M

    2006-03-31

    We report an undocumented major warming of the Antarctic winter troposphere that is larger than any previously identified regional tropospheric warming on Earth. This result has come to light through an analysis of recently digitized and rigorously quality controlled Antarctic radiosonde observations. The data show that regional midtropospheric temperatures have increased at a statistically significant rate of 0.5 degrees to 0.7 degrees Celsius per decade over the past 30 years. Analysis of the time series of radiosonde temperatures indicates that the data are temporally homogeneous. The available data do not allow us to unambiguously assign a cause to the tropospheric warming at this stage.

  10. Testing Speaking.

    ERIC Educational Resources Information Center

    Kitao, S. Kathleen; Kitao, Kenji

    Speaking a second language is probably the most difficult skill to test in that it involves a combination of skills that may have no correlation with each other, and which do not lend themselves to objective testing. In addition, what can be understood is a function of the listener's background and ability as well as those of the speaker. Another…

  11. Microalbumin Test

    MedlinePlus

    ... test to detect very small levels of a blood protein (albumin) in your urine. A microalbumin test is used ... kidney disease. Healthy kidneys filter waste from your blood and hang on to the healthy components, including proteins such as albumin. Kidney damage can cause proteins to leak through ...

  12. Testing Behavior.

    ERIC Educational Resources Information Center

    Zirkel, Perry A.

    2003-01-01

    Analyzes Georgia high-stakes testing case involving administrative law judge's recommendation (subsequently approved) that fifth-grade science teacher's teaching certificate be suspended for giving his students pretest copies of the Iowa Tests of Basic Skills. Suggests No Child Left Behind Act will spawn similar litigation in the future. (PKP)

  13. Strength Testing.

    ERIC Educational Resources Information Center

    Londeree, Ben R.

    1981-01-01

    Postural deviations resulting from strength and flexibility imbalances include swayback, scoliosis, and rounded shoulders. Screening tests are one method for identifying strength problems. Tests for the evaluation of postural problems are described, and exercises are presented for the strengthening of muscles. (JN)

  14. The mammalian centrosome and its functional significance

    PubMed Central

    2008-01-01

    Primarily known for its role as major microtubule organizing center, the centrosome is increasingly being recognized for its functional significance in key cell cycle regulating events. We are now at the beginning of understanding the centrosome’s functional complexities and its major impact on directing complex interactions and signal transduction cascades important for cell cycle regulation. The centrosome orchestrates entry into mitosis, anaphase onset, cytokinesis, G1/S transition, and monitors DNA damage. Recently, the centrosome has also been recognized as major docking station where regulatory complexes accumulate including kinases and phosphatases as well as numerous other cell cycle regulators that utilize the centrosome as platform to coordinate multiple cell cycle-specific functions. Vesicles that are translocated along microtubules to and away from centrosomes may also carry enzymes or substrates that use centrosomes as main docking station. The centrosome’s role in various diseases has been recognized and a wealth of data has been accumulated linking dysfunctional centrosomes to cancer, Alstrom syndrome, various neurological disorders, and others. Centrosome abnormalities and dysfunctions have been associated with several types of infertility. The present review highlights the centrosome’s significant roles in cell cycle events in somatic and reproductive cells and discusses centrosome abnormalities and implications in disease. PMID:18437411

  15. Diagnosis of monoclonal gammopathy of renal significance.

    PubMed

    Bridoux, Frank; Leung, Nelson; Hutchison, Colin A; Touchard, Guy; Sethi, Sanjeev; Fermand, Jean-Paul; Picken, Maria M; Herrera, Guillermo A; Kastritis, Efstathios; Merlini, Giampaolo; Roussel, Murielle; Fervenza, Fernando C; Dispenzieri, Angela; Kyle, Robert A; Nasr, Samih H

    2015-04-01

    Monoclonal gammopathy of renal significance (MGRS) regroups all renal disorders caused by a monoclonal immunoglobulin (MIg) secreted by a nonmalignant B-cell clone. By definition, patients with MGRS do not meet the criteria for overt multiple myeloma/B-cell proliferation, and the hematologic disorder is generally consistent with monoclonal gammopathy of undetermined significance (MGUS). However, MGRS is associated with high morbidity due to the severity of renal and sometimes systemic lesions induced by the MIg. Early recognition is crucial, as suppression of MIg secretion by chemotherapy often improves outcomes. The spectrum of renal diseases in MGRS is wide, including old entities such as AL amyloidosis and newly described lesions, particularly proliferative glomerulonephritis with monoclonal Ig deposits and C3 glomerulopathy with monoclonal gammopathy. Kidney biopsy is indicated in most cases to determine the exact lesion associated with MGRS and evaluate its severity. Diagnosis requires integration of morphologic alterations by light microscopy, immunofluorescence (IF), electron microscopy, and in some cases by IF staining for Ig isotypes, immunoelectron microscopy, and proteomic analysis. Complete hematologic workup with serum and urine protein electrophoresis, immunofixation, and serum-free light-chain assay is required. This review addresses the pathologic and clinical features of MGRS lesions, indications of renal biopsy, and a proposed algorithm for the hematologic workup.

  16. Adaptive significance of root grafting in trees

    SciTech Connect

    Loehle, C.; Jones, R.

    1988-12-31

    Root grafting has long been observed in forest trees but the adaptive significance of this trait has not been fully explained. Various authors have proposed that root grafting between trees contributes to mechanical support by linking adjacent root systems. Keeley proposes that this trait would be of greatest advantage in swamps where soils provide poor mechanical support. He provides as evidence a greenhouse study of Nyssa sylvatica Marsh in which seedlings of swamp provenance formed between-individual root grafts more frequently than upland provenance seedlings. In agreement with this within-species study, Keeley observed that arid zone species rarely exhibit grafts. Keeley also demonstrated that vines graft less commonly than trees, and herbs never do. Since the need for mechanical support coincides with this trend, these data seem to support his model. In this paper, the authors explore the mechanisms and ecological significance of root grafting, leading to predictions of root grafting incidence. Some observations support and some contradict the mechanical support hypothesis.

  17. Early significant ontogenetic changes in snake venoms.

    PubMed

    Wray, Kenneth P; Margres, Mark J; Seavy, Margaret; Rokyta, Darin R

    2015-03-01

    Snake venom plays a critical role in food acquisition, digestion, and defense. Venoms are known to change throughout the life of some snake species, but nothing is known about the venom composition of hatchling/neonate snakes prior to and just after their first shedding cycle, despite this being a critical time in the life of the snake. Using a cohort of Crotalus horridus and two cohorts of Crotalus adamanteus, we showed for the first time that snakes undergo significant changes in venom composition after the postnatal shedding event. The number of changes among cohorts ranged widely and there was wide variation in the direction of protein regulation, which appeared to be on a locus-specific level rather than protein-family level. These significant venom composition changes that take place in the first few weeks of life most likely play critical roles in venom economy and resource conservation and may partially explain the rare, post-birth maternal care found in some venomous species.

  18. Clinical and prognostic significance of coagulation assays in lung cancer.

    PubMed

    Tas, Faruk; Kilic, Leyla; Serilmez, Murat; Keskin, Serkan; Sen, Fatma; Duranyildiz, Derya

    2013-03-01

    Activation of coagulation and fibrinolysis is frequently encountered among cancer patients. Such tumors are supposed to be associated with higher risk of invasion, metastases and eventually worse outcome. The aim of this study is to explore the prognostic value of blood coagulation tests for lung cancer patients. The study comprised 110 lung cancer patients. Pretreatment blood coagulation tests including PT, aPTT, PTA, INR, D-dimer, fibrinogen levels and platelet counts were evaluated. The plasma level of all coagulation tests revealed statistically significant difference between patient and control group (p < 0.001). There was a significant association between D-Dimer levels and histological subtypes of NSCLC, pointing an elevated plasma D-dimer level in squamous cell cancer (p = 0.035). Patients with extensive stage SCLC exhibited evidently higher levels of D-Dimer, INR and PLT (p = 0.037, p = 0.042, p = 0.04, respectively). Prolongation of PT and INR had statistically significant adverse effect on survival (p = 0.05 and p = 0.014, respectively). Although prolonged aPTT and high levels of D-dimer was associated with worse survival, the difference was not statistically significant (p = 0.117, p = 0.104). Multivariate analysis revealed INR as the sole independent prognostic variable among coagulation parameters (p = 0.05). In conclusion, elevation of PT and INR are associated with decreased survival in lung cancer patients.

  19. Solid Surface Combustion Experiment Yields Significant Observations

    NASA Technical Reports Server (NTRS)

    Sacksteder, Kurt R.; Koudelka, John M.; Vergilii, Franklin

    1999-01-01

    The spread of a flame over solid fuel is not only a fundamental textbook combustion phenomenon, but also the central element of destructive fires that cause tragic loss of life and property each year. Throughout history, practical measures to prevent and fight fires have been developed, but these have often been based on lessons learned in a costly fire. Since the 1960 s, scientists and engineers have employed powerful tools of scientific research to understand the details of flame spread and how a material can be rendered nonflammable. High-speed computers have enabled complex flame simulations, whereasand lasers have provided measurements of the chemical composition, temperature, and air velocities inside flames. The microgravity environment has emerged as the third great tool for these studies. Spreading flames are complex combinations of chemical reactions and several physical processes including the transport of oxygen and fuel vapor to the flame and the transfer of heat from the flame to fresh fuel and to the surroundings. Depending on its speed, air motion in the vicinity of the flame can affect the flame in substantially different ways. For example, consider the difference between blowing on a campfire and blowing out a match. On Earth, gravity induces air motion because of buoyancy (the familiar rising hot gases); this process cannot be controlled experimentally. For theoreticians, buoyant air motion complicates the problem modeling of flame spread beyond the capacity of modern computers to simulate. The microgravity environment provides experimental control of air motion near spreading flames, with results that can be compared with detailed theory. The Solid Surface Combustion Experiment (SSCE) was designed to obtain benchmark flame spreading data in quiescent test atmospheres--the limiting case of flames spreading. Professor Robert Altenkirch, Vice President for Research at Mississippi State University, proposed the experiment concept, and the NASA Lewis

  20. Methylenetetrahydrofolate reductase: biochemical characterization and medical significance.

    PubMed

    Trimmer, Elizabeth E

    2013-01-01

    Methylenetetrahydrofolate reductase (MTHFR) catalyzes the reduction of 5,10-methylenetetrahydofolate (CH2-H4folate) to 5-methyltetrahydrofolate (CH3-H4folate). The enzyme employs a noncovalently-bound flavin adenine dinucleotide (FAD), which accepts reducing equivalents from NAD(P)H and transfers them to CH2-H4folate. The reaction provides the sole source of CH3-H4folate, which is utilized by methionine synthase in the synthesis of methionine from homocysteine. MTHFR plays a key role in folate metabolism and in the homeostasis of homocysteine; mutations in the enzyme lead to hyperhomocyst(e)inemia. A common C677T polymorphism in MTHFR has been associated with an increased risk for the development of cardiovascular disease, Alzheimer's disease, and depression in adults, and of neural tube defects in the fetus. The mutation also confers protection for certain types of cancers. This review presents the current knowledge of the enzyme, its biochemical characterization, and medical significance.

  1. Significance of Adult Pedestrian Torso Injury

    PubMed Central

    Ivarsson, B. Johan; Henary, Basem; Crandall, Jeff R.; Longhitano, Douglas

    2005-01-01

    The current paper uses data from two trauma registries to evaluate the significance of adult pedestrian torso injury relative to head and lower extremity injuries and to determine the relative importance of injuries to individual torso organs/structures. Analyses are conducted with and without adjusting for striking vehicle body type (car versus LTV). Although the incidence of torso injury is approximately 50% higher in pedestrians struck by LTVs than in those struck by cars, torso injury appears to be as an important contributor to the overall cost of pedestrian morbidity as is lower extremity injury. The most frequently injured torso organs/structures include the rib cage, lung & pleura, and liver. The results indicate a need for an increased focus on the prevention of torso injury in the design of pedestrian safety countermeasures. PMID:16179153

  2. Significant acidification in major Chinese croplands.

    PubMed

    Guo, J H; Liu, X J; Zhang, Y; Shen, J L; Han, W X; Zhang, W F; Christie, P; Goulding, K W T; Vitousek, P M; Zhang, F S

    2010-02-19

    Soil acidification is a major problem in soils of intensive Chinese agricultural systems. We used two nationwide surveys, paired comparisons in numerous individual sites, and several long-term monitoring-field data sets to evaluate changes in soil acidity. Soil pH declined significantly (P < 0.001) from the 1980s to the 2000s in the major Chinese crop-production areas. Processes related to nitrogen cycling released 20 to 221 kilomoles of hydrogen ion (H+) per hectare per year, and base cations uptake contributed a further 15 to 20 kilomoles of H+ per hectare per year to soil acidification in four widespread cropping systems. In comparison, acid deposition (0.4 to 2.0 kilomoles of H+ per hectare per year) made a small contribution to the acidification of agricultural soils across China.

  3. Physiologic and prognostic significance of "alpha coma".

    PubMed Central

    Iragui, V J; McCutchen, C B

    1983-01-01

    A patient with posthypoxic "alpha coma" is described whose EEGs were recorded before coma, within two hours following the onset of coma and after recovery. The differences observed between the alpha activity during coma and that seen before and after suggest that the alpha activity during coma and the physiologic alpha rhythm are different phenomena. This case, as well as others reported, also suggests that "alpha coma" resolving in the first 24 hours following hypoxia may have a better prognosis than "alpha coma" detected after the first day, and stresses the need for EEG monitoring begun in the immediate period following hypoxia in order to assess accurately the prognostic significance of this EEG pattern in the early stages of postanoxic encephalopathy. The aetiology of "alpha coma" also affects outcome. The survival rate appears higher in patients with respiratory arrest than in those with combined cardiopulmonary arrest. PMID:6886700

  4. Knee joint forces: prediction, measurement, and significance

    PubMed Central

    D’Lima, Darryl D.; Fregly, Benjamin J.; Patil, Shantanu; Steklov, Nikolai; Colwell, Clifford W.

    2011-01-01

    Knee forces are highly significant in osteoarthritis and in the survival and function of knee arthroplasty. A large number of studies have attempted to estimate forces around the knee during various activities. Several approaches have been used to relate knee kinematics and external forces to internal joint contact forces, the most popular being inverse dynamics, forward dynamics, and static body analyses. Knee forces have also been measured in vivo after knee arthroplasty, which serves as valuable validation of computational predictions. This review summarizes the results of published studies that measured knee forces for various activities. The efficacy of various methods to alter knee force distribution, such as gait modification, orthotics, walking aids, and custom treadmills are analyzed. Current gaps in our knowledge are identified and directions for future research in this area are outlined. PMID:22468461

  5. Significant body point labeling and tracking.

    PubMed

    Azhar, Faisal; Tjahjadi, Tardi

    2014-09-01

    In this paper, a method is presented to label and track anatomical landmarks (e.g., head, hand/arm, feet), which are referred to as significant body points (SBPs), using implicit body models. By considering the human body as an inverted pendulum model, ellipse fitting and contour moments are applied to classify it as being in Stand, Sit, or Lie posture. A convex hull of the silhouette contour is used to determine the locations of SBPs. The particle filter or a motion flow-based method is used to predict SBPs in occlusion. Stick figures of various activities are generated by connecting the SBPs. The qualitative and quantitative evaluation show that the proposed method robustly labels and tracks SBPs in various activities of two different (low and high) resolution data sets.

  6. The significance of hermeneutics to child psychotherapy.

    PubMed Central

    Mook, B

    1991-01-01

    Increasingly the philosophical discipline of hermeneutics is being applied to a systematic study of the human sciences. Yet a hermeneutic approach to psychotherapy has barely been considered. In this paper, the possible significance of a hermeneutic approach to the field of child psychotherapy is explored. Despite the fundamental differences between the two disciplines, both are faced with the task of understanding and interpreting the meaning of human expressions through words and images. Both encounter texts that call for deciphering. The author focuses first on the central concepts of experience, understanding and interpretation which lie at the heart of both disciplines. Subsequently, a hermeneutic approach to the expressions of experience in the form of child play and narratives is explored and some implications for child psychotherapy are drawn. Finally, a possible hermeneutic approach towards child psychotherapy is discussed. PMID:1958654

  7. Smoking cessation: significance and implications for children.

    PubMed

    Borchers, Andrea T; Keen, Carl L; Gershwin, M Eric

    2008-04-01

    A number of people in the USA who are still current smokers remain a staggering figure. Although this number continues to decrease, there is still a considerable amount of second-hand smoke. More importantly and for the purpose of this review, the detrimental effects of passive smoke in children is significant. We will not review the specific health effects of passive smoke, but for pediatricians, in particular, it is important to place in perspective programs that are available to influence the parents of children to stop smoking. Indeed, approximately 25% of all children aged 3-11 live in a household with at least one smoker. Despite the increasing number of communities in the states that have instituted restrictions or complete bans on smoking in the workplace and in many public areas, the principal site of smoking remains the home.

  8. Biological significance of RNA editing in cells.

    PubMed

    Tang, Wei; Fei, Yongjun; Page, Michael

    2012-09-01

    RNA editing is one of the post-transcriptional RNA processes. RNA editing generates RNA and protein diversity in eukaryotes and results in specific amino acid substitutions, deletions, and changes in gene expression levels. Adenosine-to-inosine RNA editing represents the most important class of editing in human and affects function of many genes. The importance of balancing RNA modification levels across time and space is becoming increasingly evident. In this review, we overview the biological significance of RNA editing including RNA editing in tumorigenesis, RNA editing in neuronal tissues, RNA editing as a regulator of gene expression, and RNA editing in dsRNA-mediated gene silencing, which may increase our understanding of RNA biology.

  9. Pyrolysis of wastewater biosolids significantly reduces estrogenicity.

    PubMed

    Hoffman, T C; Zitomer, D H; McNamara, P J

    2016-11-05

    Most wastewater treatment processes are not specifically designed to remove micropollutants. Many micropollutants are hydrophobic so they remain in the biosolids and are discharged to the environment through land-application of biosolids. Micropollutants encompass a broad range of organic chemicals, including estrogenic compounds (natural and synthetic) that reside in the environment, a.k.a. environmental estrogens. Public concern over land application of biosolids stemming from the occurrence of micropollutants hampers the value of biosolids which are important to wastewater treatment plants as a valuable by-product. This research evaluated pyrolysis, the partial decomposition of organic material in an oxygen-deprived system under high temperatures, as a biosolids treatment process that could remove estrogenic compounds from solids while producing a less hormonally active biochar for soil amendment. The estrogenicity, measured in estradiol equivalents (EEQ) by the yeast estrogen screen (YES) assay, of pyrolyzed biosolids was compared to primary and anaerobically digested biosolids. The estrogenic responses from primary solids and anaerobically digested solids were not statistically significantly different, but pyrolysis of anaerobically digested solids resulted in a significant reduction in EEQ; increasing pyrolysis temperature from 100°C to 500°C increased the removal of EEQ with greater than 95% removal occurring at or above 400°C. This research demonstrates that biosolids treatment with pyrolysis would substantially decrease (removal>95%) the estrogens associated with this biosolids product. Thus, pyrolysis of biosolids can be used to produce a valuable soil amendment product, biochar, that minimizes discharge of estrogens to the environment.

  10. Are Carotid Stent Fractures Clinically Significant?

    SciTech Connect

    Garcia-Toca, Manuel; Rodriguez, Heron E.; Naughton, Peter A.; Keeling, Aiofee; Phade, Sachin V.; Morasch, Mark D.; Kibbe, Melina R.; Eskandari, Mark K.

    2012-04-15

    Purpose: Late stent fatigue is a known complication after carotid artery stenting (CAS) for cervical carotid occlusive disease. The purpose of this study was to determine the prevalence and clinical significance of carotid stent fractures. Materials and Methods: A single-center retrospective review of 253 carotid bifurcation lesions treated with CAS and mechanical embolic protection from April 2001 to December 2009 was performed. Stent integrity was analyzed by two independent observers using multiplanar cervical plain radiographs with fractures classified into the following types: type I = single strut fracture; type II = multiple strut fractures; type III = transverse fracture; and type IV = transverse fracture with dislocation. Mean follow-up was 32 months. Results: Follow-up imaging was completed on 106 self-expanding nitinol stents (26 closed-cell and 80 open-cell stents). Eight fractures (7.5%) were detected (type I n = 1, type II n = 6, and type III n = 1). Seven fractures were found in open-cell stents (Precise n = 3, ViVEXX n = 2, and Acculink n = 2), and 1 fracture was found in a closed-cell stent (Xact n = 1) (p = 0.67). Only a previous history of external beam neck irradiation was associated with fractures (p = 0.048). No associated clinical sequelae were observed among the patients with fractures, and only 1 patient had an associated significant restenosis ({>=}80%) requiring reintervention. Conclusions: Late stent fatigue after CAS is an uncommon event and rarely clinically relevant. Although cell design does not appear to influence the occurrence of fractures, lesion characteristics may be associated risk factors.

  11. [Base excess. Parameter with exceptional clinical significance].

    PubMed

    Schaffartzik, W

    2007-05-01

    The base excess of blood (BE) plays an important role in the description of the acid-base status of a patient and is gaining in clinical interest. Apart from the Quick test, the age, the injury severity score and the Glasgow coma scale, the BE is becoming more and more important to identify, e. g. the risk of mortality for patients with multiple injuries. According to Zander the BE is calculated using the pH, pCO(2), haemoglobin concentration and the oxygen saturation of haemoglobin (sO(2)). The use of sO(2 )allows the blood gas analyser to determine only one value of BE, independent of the type of blood sample analyzed: arterial, mixed venous or venous. The BE and measurement of the lactate concentration (cLac) play an important role in diagnosing critically ill patients. In general, the change in BE corresponds to the change in cLac. If DeltaBE is smaller than DeltacLac the reason could be therapy with HCO(3)(-) but also with infusion solutions containing lactate. Physician are very familiar with the term BE, therefore, knowledge about an alkalizing or acidifying effect of an infusion solution would be very helpful in the treatment of patients, especially critically ill patients. Unfortunately, at present the description of an infusion solution with respect to BE has not yet been accepted by the manufacturers.

  12. [Significance of prognostic parameters in acute pancreatitis].

    PubMed

    Guastella, T; Scuderi, M; Di Stefano, A; Scala, R; Rapisarda, D; Succi, L; Russello, D

    1993-07-01

    The diagnostic and therapeutic approach to Acute Pancreatitis (A.P.) is directly related to the clinical presentation. The Authors reviewed the data of 66 patients, hospitalized between October 1989 and December 1991, to verify the effectiveness of the prognostic criteria suggested by Ranson (1974), Mercadier (1977) and Imrie (1978). A.P. was of biliary origin in the majority of the patients (63.5%); five patients (7.5%) had an acute alcoholic pancreatitis, while the aetiology was traumatic or unknown in the remaining cases. A complicated clinical course was defined by the development of pseudocyst, pancreatic abscess, digestive haemorrhage, death or prolonged hospitalization (more than 20 days). The 28.8% of the patients developed complications during hospitalization. There were seven pancreatic pseudocysts, six pulmonary complications, three renal insufficiencies, two vascular complications, two sepsies and a gastrointestinal haemorrhage. The mean hospitalization period was 15.1 days (range 1-112). The Authors conclude that the three different prognostic criteria are equally useful to test the severity of A.P. attacks allowing to identify patients with the higher risk to develop complications during hospitalization.

  13. [Significance of medical statistics in insurance medicine].

    PubMed

    Becher, J

    2001-03-01

    Knowledge of medical statistics is of great benefit to every insurance medical officer as they facilitate communication with actuaries, allow officers to make their own calculations and are the basis for correctly interpreting medical journals. Only about 20% of original work in medicine today is published without statistics or only with descriptive statistics--and this trend is falling. The reader of medical publications should be in a position to make a critical analysis of the methodology and content, since one cannot always rely on the conclusions drawn by the authors: statistical errors appear very frequently in medical publications. Due to the specific methodological features involved, the assessment of meta-analyses demands special attention. The number of published meta-analyses has risen 40-fold over the last ten years. Important examples for the practical use of statistical methods in insurance medicine include estimating extramortality from published survival analyses and evaluating diagnostic test results. The purpose of this article is to highlight statistical problems and issues of relevance to insurance medicine and to establish the bases for understanding them.

  14. Optical testing

    NASA Technical Reports Server (NTRS)

    Wyant, James; Hochberg, Eric; Breault, Robert; Greivenkamp, John; Hunt, Gary; Mason, Pete; Mcguire, James; Meinel, Aden; Morris, Mike; Scherr, Larry

    1992-01-01

    Optical testing is one of the most vital elements in the process of preparing an optical instrument for launch. Without well understood, well controlled, and well documented test procedures, current and future mission goals will be jeopardized. We should keep in mind that the reason we test is to provide an opportunity to catch errors, oversights, and problems on the ground, where solutions are possible and difficulties can be rectified. Consequently, it is necessary to create tractable test procedures that truly provide a measure of the performance of all optical elements and systems under conditions which are close to those expected in space. Where testing is not feasible, accurate experiments are required in order to perfect models that can exactly predict the optical performance. As we stretch the boundaries of technology to perform more complex space and planetary investigations, we must expand the technology required to test the optical components and systems which we send into space. As we expand the observational wavelength ranges, so must we expand our range of optical sources and detectors. As we increase resolution and sensitivity, our understanding of optical surfaces to accommodate more stringent figure and scatter requirements must expand. Only with research and development in these areas can we hope to achieve success in the ever increasing demands made on optical testing by the highly sophisticated missions anticipated over the next two decades. Technology assessment and development plan for surface figure, surface roughness, alignment, image quality, radiometric quantities, and stray light measurement are presented.

  15. Estimating Hydraulic Parameters When Poroelastic Effects Are Significant

    USGS Publications Warehouse

    Berg, S.J.; Hsieh, P.A.; Illman, W.A.

    2011-01-01

    For almost 80 years, deformation-induced head changes caused by poroelastic effects have been observed during pumping tests in multilayered aquifer-aquitard systems. As water in the aquifer is released from compressive storage during pumping, the aquifer is deformed both in the horizontal and vertical directions. This deformation in the pumped aquifer causes deformation in the adjacent layers, resulting in changes in pore pressure that may produce drawdown curves that differ significantly from those predicted by traditional groundwater theory. Although these deformation-induced head changes have been analyzed in several studies by poroelasticity theory, there are at present no practical guidelines for the interpretation of pumping test data influenced by these effects. To investigate the impact that poroelastic effects during pumping tests have on the estimation of hydraulic parameters, we generate synthetic data for three different aquifer-aquitard settings using a poroelasticity model, and then analyze the synthetic data using type curves and parameter estimation techniques, both of which are based on traditional groundwater theory and do not account for poroelastic effects. Results show that even when poroelastic effects result in significant deformation-induced head changes, it is possible to obtain reasonable estimates of hydraulic parameters using methods based on traditional groundwater theory, as long as pumping is sufficiently long so that deformation-induced effects have largely dissipated. ?? 2011 The Author(s). Journal compilation ?? 2011 National Ground Water Association.

  16. Estimation of the geochemical threshold and its statistical significance

    USGS Publications Warehouse

    Miesch, A.T.

    1981-01-01

    A statistic is proposed for estimating the geochemical threshold and its statistical significance, or it may be used to identify a group of extreme values that can be tested for significance by other means. The statistic is the maximum gap between adjacent values in an ordered array after each gap has been adjusted for the expected frequency. The values in the ordered array are geochemical values transformed by either ln(?? - ??) or ln(?? - ??) and then standardized so that the mean is zero and the variance is unity. The expected frequency is taken from a fitted normal curve with unit area. The midpoint of an adjusted gap that exceeds the corresponding critical value may be taken as an estimate of the geochemical threshold, and the associated probability indicates the likelihood that the threshold separates two geochemical populations. The adjusted gap test may fail to identify threshold values if the variation tends to be continuous from background values to the higher values that reflect mineralized ground. However, the test will serve to identify other anomalies that may be too subtle to have been noted by other means. ?? 1981.

  17. Patch tests*

    PubMed Central

    Lazzarini, Rosana; Duarte, Ida; Ferreira, Alessandra Lindmayer

    2013-01-01

    Patch tests were introduced as a diagnostic tool in the late nineteenth century. Since then, they have improved considerably becoming what they are today. Patch tests are used in the diagnostic investigation of contact dermatitis worldwide. Batteries or series previously studied and standardized should be used in patch testing. The methodology is simple, but it requires adequate training for the results to be correctly interpreted and used. Despite having been used for over a century, it needs improvement like all other diagnostic techniques in the medical field. PMID:24474094

  18. The effect of pranayama on test anxiety and test performance

    PubMed Central

    Nemati, Azadeh

    2013-01-01

    Objectives: In an educational setting, anxiety is often experienced by students when taking a test; which is called ‘test anxiety’. This study intends to investigate the effect of doing pranayama on test anxiety and test performance. Materials and Methods: The participants consisted of 107 MA students who were randomly assigned to the control and experimental groups. The students of the experimental group practiced pranayama for one full semester. Sarason's (1980) test anxiety scale was given to both the control and experimental groups in the final session, before taking the examination. Results: After practicing pranayama, only 33% of the participants of the experimental group experienced high test anxiety, while this percentage was nearly twice in the control group (66.7%). Furthermore, the result of the t-test for test anxiety and test performance showed that the students of the experimental group had significantly lower mean test anxiety scores (M = 16.00) as compared to the students of the control group (M = 19.31). Also, the test performance scores of the experimental group were higher when compared with the control group. There was a negative correlation between the final test performance and test anxiety (r = −.204, P < .05). Conclusions: Pranayama seems to have a significant positive effect on test anxiety and test performance. It could be used as an important technique by students prior to their examinations, to reduce their test anxiety and increase their test performance. PMID:23439436

  19. Misconceptions Tests or Misconceived Tests?

    ERIC Educational Resources Information Center

    Griggs, Richard A.; Ransdell, Sarah E.

    1987-01-01

    States that taking a high school psychology course did not improve the performance of college students in an introductory psychology class on a modified version of Vaughan's misconceptions test (Test of Common Beliefs). Concludes that while college experience did lead to some improvement, comparison with other studies indicates that perhaps the…

  20. The significance of interleukin 8 in urine

    PubMed Central

    Rao, W; Evans, G; Finn, A

    2001-01-01

    AIMS—To assess the implications of detection of interleukin 8 (IL-8) in urine.
METHODS—IL-8 was measured by immunoassay in all 305 urine samples from children aged 0-18.4 years received by our microbiology laboratory during four weeks, with a retrospective structured case note audit for all those in whom IL-8, white cells, or bacteria were detected. Patients were divided into three groups: urinary tract infection (UTI), at least one sample with ⩾5 leucocytes × 109/l and ⩾105 cultured bacteria/ml; possible UTI, at least one sample with ⩾5 leucocytes × 109/l or ⩾105 cultured bacteria/ml but not both; UTI unlikely, sample(s) with <5 leucocytes × 109/l and <105 cultured bacteria/ml. Medical records were sought for all in groups 1 (14/14 found) and 2 (18/21 found) and those in group 3 (41/59 found) in whose urine any leucocytes, cultured bacteria, or IL-8 were detected.
RESULTS—IL-8 was detected in 58/305 samples from 48/264 patients. IL-8 was detected in at least one urine sample from 13/14 patients with confirmed UTI (group 1); in 11/21 patients with possible UTI (group 2), of whom two were treated as UTI; and in 23/228 patients without UTI. Using a cut off of 200 pg/ml, urine IL-8 had a sensitivity of 93% and a specificity of 90% for diagnosing UTI.
CONCLUSIONS—Urine IL-8 is a sensitive test for UTI, but is poorly specific as it is also present in a variety of other infectious and inflammatory disorders.

 PMID:11517116

  1. Clinically significant drug interactions with newer antidepressants.

    PubMed

    Spina, Edoardo; Trifirò, Gianluca; Caraci, Filippo

    2012-01-01

    After the introduction of selective serotonin reuptake inhibitors (SSRIs), other newer antidepressants with different mechanisms of action have been introduced in clinical practice. Because antidepressants are commonly prescribed in combination with other medications used to treat co-morbid psychiatric or somatic disorders, they are likely to be involved in clinically significant drug interactions. This review examines the drug interaction profiles of the following newer antidepressants: escitalopram, venlafaxine, desvenlafaxine, duloxetine, milnacipran, mirtazapine, reboxetine, bupropion, agomelatine and vilazodone. In general, by virtue of a more selective mechanism of action and receptor profile, newer antidepressants carry a relatively low risk for pharmacodynamic drug interactions, at least as compared with first-generation antidepressants, i.e. monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants (TCAs). On the other hand, they are susceptible to pharmacokinetic drug interactions. All new antidepressants are extensively metabolized in the liver by cytochrome P450 (CYP) isoenzymes, and therefore may be the target of metabolically based drug interactions. Concomitant administration of inhibitors or inducers of the CYP isoenzymes involved in the biotransformation of specific antidepressants may cause changes in their plasma concentrations. However, due to their relatively wide margin of safety, the consequences of such kinetic modifications are usually not clinically relevant. Conversely, some newer antidepressants may cause pharmacokinetic interactions through their ability to inhibit specific CYPs. With regard to this, duloxetine and bupropion are moderate inhibitors of CYP2D6. Therefore, potentially harmful drug interactions may occur when they are coadministered with substrates of these isoforms, especially compounds with a narrow therapeutic index. The other new antidepressants are only weak inhibitors or are not inhibitors of CYP isoforms at

  2. The Trail Making Test.

    PubMed

    Llinàs-Reglà, Jordi; Vilalta-Franch, Joan; López-Pousa, Secundino; Calvó-Perxas, Laia; Torrents Rodas, David; Garre-Olmo, Josep

    2017-03-01

    The Trail Making Test (TMT) is used as an indicator of visual scanning, graphomotor speed, and executive function. The aim of this study was to examine the TMT relationships with several neuropsychological measures and to provide normative data in community-dwelling participants of 55 years and older. A population-based Spanish-speaking sample of 2,564 participants was used. The TMT, Symbol Digit Test, Stroop Color-Word Test, Digit Span Test, Verbal Fluency tests, and the MacQuarrie Test for Mechanical Ability tapping subtest were administered. Exploratory factor analyses and regression lineal models were used. Normative data for the TMT scores were obtained. A total of 1,923 participants (76.3%) participated, 52.4% were women, and the mean age was 66.5 years (Digit Span = 8.0). The Symbol Digit Test, MacQuarrie Test for Mechanical Ability tapping subtest, Stroop Color-Word Test, and Digit Span Test scores were associated in the performance of most TMT scores, but the contribution of each measure was different depending on the TMT score. Normative tables according to significant factors such as age, education level, and sex were created. Measures of visual scanning, graphomotor speed, and visuomotor processing speed were more related to the performance of the TMT-A score, while working memory and inhibition control were mainly associated with the TMT-B and derived TMT scores.

  3. Reconstructing networks of pathways via significance analysis of their intersections

    PubMed Central

    Francesconi, Mirko; Remondini, Daniel; Neretti, Nicola; Sedivy, John M; Cooper, Leon N; Verondini, Ettore; Milanesi, Luciano; Castellani, Gastone

    2008-01-01

    Background Significance analysis at single gene level may suffer from the limited number of samples and experimental noise that can severely limit the power of the chosen statistical test. This problem is typically approached by applying post hoc corrections to control the false discovery rate, without taking into account prior biological knowledge. Pathway or gene ontology analysis can provide an alternative way to relax the significance threshold applied to single genes and may lead to a better biological interpretation. Results Here we propose a new analysis method based on the study of networks of pathways. These networks are reconstructed considering both the significance of single pathways (network nodes) and the intersection between them (links). We apply this method for the reconstruction of networks of pathways to two gene expression datasets: the first one obtained from a c-Myc rat fibroblast cell line expressing a conditional Myc-estrogen receptor oncoprotein; the second one obtained from the comparison of Acute Myeloid Leukemia and Acute Lymphoblastic Leukemia derived from bone marrow samples. Conclusion Our method extends statistical models that have been recently adopted for the significance analysis of functional groups of genes to infer links between these groups. We show that groups of genes at the interface between different pathways can be considered as relevant even if the pathways they belong to are not significant by themselves. PMID:18460182

  4. Cholesterol Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Cholesterol Share this page: Was this page helpful? Also known as: Blood Cholesterol Formal name: Total Cholesterol Related tests: HDL Cholesterol , ...

  5. VMA Test

    MedlinePlus

    ... is primarily used to detect and rule out neuroblastomas in children with an abdominal mass or other ... homovanillic acid (HVA) test to help diagnose a neuroblastoma, to monitor the effectiveness of treatment, and to ...

  6. Neuropathy Tests

    MedlinePlus

    ... strength and tone, and the ability to sense vibration, light touch, body position, temperature, and pain. Depending ... tests that record the ability to sense touch, vibration, cooling, and heat Nerve biopsy – to evaluate damage ...

  7. Runflat Testing

    DTIC Science & Technology

    2015-09-09

    tire assembly tread life combat flat central tire inflation system (CTIS) 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...2 2. FACILITIES AND INSTRUMENTATION ......................... 2 2.1 Facilities...2 2.2 Instrumentation ...................................................................... 3 3. REQUIRED TEST

  8. Iron Test

    MedlinePlus

    ... detect and help diagnose iron deficiency or iron overload. In people with anemia , these tests can help ... also be ordered when iron deficiency or iron overload is suspected. Early iron deficiency often goes unnoticed. ...

  9. Albumin Test

    MedlinePlus

    ... may also be ordered to evaluate a person's nutritional status. ^ Back to top When is it ordered? An ... albumin test to check or monitor a person's nutritional status. However, since albumin concentrations respond to a variety ...

  10. Trypsinogen Test

    MedlinePlus

    ... of some newborn screening programs to screen for cystic fibrosis (CF) . It may be used in conjunction with a sweat chloride test and/or a cystic fibrosis gene mutation panel to help identify CF. IRT ...

  11. Amylase Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Amylase Share this page: Was this page helpful? Also known as: Amy Formal name: Amylase Related tests: Lipase , Trypsin , Trypsinogen At a Glance ...

  12. AMA Test

    MedlinePlus

    ... M2 test may be ordered to help diagnose primary biliary cirrhosis (PBC) . PBC is a serious condition in which ... be performed to look for characteristic signs of primary biliary cirrhosis in the liver tissue and to confirm the ...

  13. Sodium Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Sodium Share this page: Was this page helpful? Also known as: Na Formal name: Sodium Related tests: Chloride , Bicarbonate , Potassium , Electrolytes , Osmolality , Basic ...

  14. Fungal Tests

    MedlinePlus

    ... diagnosis is needed, as in cases of persistent, deep, or systemic infections, more extensive testing may be ... mouth (thrush) Vaginal itching and discharge (yeast infection) Deep and systemic fungal infections may cause a variety ...

  15. ACT Test

    MedlinePlus

    Advertisement Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: Policy | Opportunities PLEASE NOTE: Your web browser ...

  16. Troponins Test

    MedlinePlus

    ... affected by damage to skeletal muscles, so injections, accidents, and drugs that can damage muscle do not ... Learn more about ... Understanding Your Tests Inside the Lab In the News Article Index About This Site ...

  17. Test report :

    SciTech Connect

    Rose, David Martin; Schenkman, Benjamin L.; Borneo, Daniel R.

    2013-08-01

    The Department of Energy Office of Electricity (DOE/OE), Sandia National Laboratory (SNL) and the Base Camp Integration Lab (BCIL) partnered together to incorporate an energy storage system into a microgrid configured Forward Operating Base to reduce the fossil fuel consumption and to ultimately save lives. Energy storage vendors have supplied their systems to SNL Energy Storage Test Pad (ESTP) for functional testing and a subset of these systems were selected for performance evaluation at the BCIL. The technologies tested were electro-chemical energy storage systems comprised of lead acid, lithium-ion or zinc-bromide. MILSPRAY Military Technologies has developed an energy storage system that utilizes lead acid batteries to save fuel on a military microgrid. This report contains the testing results and some limited assessment of the Milspray Scorpion Energy Storage Device.

  18. Test Anxiety

    MedlinePlus

    ... for Parents for Kids for Teens Teens Home Body Mind Sexual Health Food & Fitness Diseases & Conditions Infections Q& ... Like other anxiety reactions, test anxiety affects the body and the mind. When you're under stress, your body releases ...

  19. Lactate Test

    MedlinePlus

    ... oxygen delivered to cells and tissues, such as shock or congestive heart failure , this test can be ... treated for an acute condition, such as sepsis, shock or heart attack , or a chronic condition, such ...

  20. Tested Demonstrations.

    ERIC Educational Resources Information Center

    Gilbert, George L.

    1990-01-01

    Included are three demonstrations that include the phase change of ice when under pressure, viscoelasticity and colloid systems, and flame tests for metal ions. The materials, procedures, probable results, and applications to real life situations are included. (KR)

  1. Ammonia Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Ammonia Share this page: Was this page helpful? Also known as: NH3 Formal name: Ammonia, plasma Related tests: Liver Panel , ALT , AST , ALP , ...

  2. Test report :

    SciTech Connect

    Rose, David Martin; Schenkman, Benjamin L.; Borneo, Daniel R.

    2013-10-01

    The Department of Energy Office of Electricity (DOE/OE), Sandia National Laboratories (SNL) and the Base Camp Integration Lab (BCIL) partnered together to incorporate an energy storage system into a microgrid configured Forward Operating Base to reduce the fossil fuel consumption and to ultimately save lives. Energy storage vendors will be sending their systems to SNL Energy Storage Test Pad (ESTP) for functional testing and then to the BCIL for performance evaluation. The technologies that will be tested are electro-chemical energy storage systems comprising of lead acid, lithium-ion or zinc-bromide. Raytheon/KTech has developed an energy storage system that utilizes zinc-bromide flow batteries to save fuel on a military microgrid. This report contains the testing results and some limited analysis of performance of the Raytheon/KTech Zinc-Bromide Energy Storage System.

  3. Test Report :

    SciTech Connect

    Rose, David Martin; Schenkman, Benjamin L.; Borneo, Daniel R.

    2013-10-01

    The Department of Energy Office of Electricity (DOE/OE), Sandia National Laboratories (SNL) and the Base Camp Integration Lab (BCIL) partnered together to incorporate an energy storage system into a microgrid configured Forward Operating Base to reduce the fossil fuel consumption and to ultimately save lives. Energy storage vendors will be sending their systems to SNL Energy Storage Test Pad (ESTP) for functional testing and then to the BCIL for performance evaluation. The technologies that will be tested are electro-chemical energy storage systems comprising of lead acid, lithium-ion or zinc-bromide. GS Battery and EPC Power have developed an energy storage system that utilizes zinc-bromide flow batteries to save fuel on a military microgrid. This report contains the testing results and some limited analysis of performance of the GS Battery, EPC Power HES RESCU.

  4. Genomic Testing

    MedlinePlus

    ... Services released a report identifying gaps in the regulation, oversight, and usefulness of genetic testing. They expressed ... December 20, 2016 Content source: Center for Surveillance, Epidemiology and Laboratory Services (CSELS) , Public Health Genomics Email ...

  5. Test report :

    SciTech Connect

    Rose, David Martin; Schenkman, Benjamin L.; Borneo, Daniel R.

    2013-08-01

    The Department of Energy Office of Electricity (DOE/OE), Sandia National Laboratory (SNL) and the Base Camp Integration Lab (BCIL) partnered together to incorporate an energy storage system into a microgrid configured Forward Operating Base to reduce the fossil fuel consumption and to ultimately save lives. Energy storage vendors will be sending their systems to SNL Energy Storage Test Pad (ESTP) for functional testing and then to the BCIL for performance evaluation. The technologies that will be tested are electro-chemical energy storage systems comprised of lead acid, lithium-ion or zinc-bromide. Princeton Power Systems has developed an energy storage system that utilizes lithium ion phosphate batteries to save fuel on a military microgrid. This report contains the testing results and some limited analysis of performance of the Princeton Power Systems Prototype Energy Storage System.

  6. Digoxin test

    MedlinePlus

    Heart failure - digoxin test ... Mann DL. Management of patients with heart failure with reduced ejection fraction. In: Mann DL, Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of ...

  7. Bilirubin Test

    MedlinePlus

    ... Also known as: Total Bilirubin; TBIL; Neonatal Bilirubin; Direct Bilirubin; Conjugated Bilirubin; Indirect Bilirubin; Unconjugated Bilirubin Formal ... Hepatitis B ; Hepatitis C ; Complete Blood Count ; Urinalysis ; Direct Antiglobulin Test ; Haptoglobin ; Reticulocyte Count All content on ...

  8. Microbial resistance to disinfectants: mechanisms and significance

    SciTech Connect

    Hoff, J.C.; Akin, E.W.

    1986-11-01

    Drinking water disinfection provides the final barrier to transmission of a wide variety of potentially waterborne infectious agents including pathogenic bacteria, viruses, and protozoa. These agents differ greatly in their innate resistance to inactivation by disinfectants, ranging from extremely sensitive bacteria to highly resistant protozoan cysts. The close similarity between microorganism inactivation rates and the kinetics of chemical reactions has long been recognized. Ideally, under carefully controlled conditions, microorganism inactivation rates simulate first-order chemical reaction rates, making it possible to predict the effectiveness of disinfection under specific conditions. In practice, changes in relative resistance and deviations from first-order kinetics are caused by a number of factors, including microbial growth conditions, aggregation, and association with particulate materials. The net effect of all these factors is a reduction in the effectiveness and predictability of disinfection processes. To ensure effective pathogen control, disinfectant concentrations and contact times greater than experimentally determined values may be required. Of the factors causing enhanced disinfection resistance, protection by association with particulate matter is the most significant. Therefore, removal of particulate matter is an important step in increasing the effectiveness of disinfection processes.

  9. Finding Statistically Significant Communities in Networks

    PubMed Central

    Lancichinetti, Andrea; Radicchi, Filippo; Ramasco, José J.; Fortunato, Santo

    2011-01-01

    Community structure is one of the main structural features of networks, revealing both their internal organization and the similarity of their elementary units. Despite the large variety of methods proposed to detect communities in graphs, there is a big need for multi-purpose techniques, able to handle different types of datasets and the subtleties of community structure. In this paper we present OSLOM (Order Statistics Local Optimization Method), the first method capable to detect clusters in networks accounting for edge directions, edge weights, overlapping communities, hierarchies and community dynamics. It is based on the local optimization of a fitness function expressing the statistical significance of clusters with respect to random fluctuations, which is estimated with tools of Extreme and Order Statistics. OSLOM can be used alone or as a refinement procedure of partitions/covers delivered by other techniques. We have also implemented sequential algorithms combining OSLOM with other fast techniques, so that the community structure of very large networks can be uncovered. Our method has a comparable performance as the best existing algorithms on artificial benchmark graphs. Several applications on real networks are shown as well. OSLOM is implemented in a freely available software (http://www.oslom.org), and we believe it will be a valuable tool in the analysis of networks. PMID:21559480

  10. Pseudogene redux with new biological significance.

    PubMed

    Salmena, Leonardo

    2014-01-01

    The study of pseudogenes, originally dismissed as genomic relics of evolutionary selection, has seen a resurgence in scientific literature, in addition to being a peculiar topic of discussion in theological debates. For a long time, pseudogenes have been touted as a beacon of natural selection and a definitive proof of evolution due to the slow mutation rate that differentiated them from their parental genes and ultimately caused their genetic demise as functional genes. It now seems that "creationists" have co-opted some recent reports identifying unheralded biological functions to pseudogens and other noncoding RNAs as evidence to undermine the existence of evolution and supporting intelligent design. This issue of Methods in Molecular Biology focused on pseudogenes will certainly not end, nor enter this debate; however, scientists who are also genomics and pseudogene enthusiasts will certainly appreciate that many scientists are thinking about these particular genetic elements in new and interesting ways. With this new interest in a biological significance and "non-junk" role for pseudogenes and other noncoding RNAs, new methods and approaches are being developed to unlock the mystery of these ancient artifacts we know as pseudogenes. In this brief introductory chapter we highlight the renewed interest in pseudogenes and review a rationale for intensification of pseudogene-related research.

  11. AEG-1/MTDH/LYRIC: Clinical Significance

    PubMed Central

    Sarkar, Devanand; Fisher, Paul B.

    2014-01-01

    “Gain-of-function” and “loss-of-function” studies in human cancer cells and analysis of a transgenic mouse model have convincingly established that AEG-1/MTDH/LYRIC performs a seminal role in regulating proliferation, invasion, angiogenesis, metastasis, and chemoresistance, the salient defining hallmarks of cancer. These observations are strongly buttressed by clinicopathologic correlations of AEG-1/MTDH/LYRIC expression in a diverse array of cancers distinguishing AEG-1/MTDH/LYRIC as an independent biomarker for highly aggressive metastatic disease with poor prognosis. AEG-1/MTDH/LYRIC has been shown to be a marker predicting response to chemotherapy, and serum anti-AEG-1/MTDH/LYRIC antibody titer also serves as a predictor of advanced stages of aggressive cancer. However, inconsistent findings have been reported regarding the localization of AEG-1/MTDH/LYRIC protein in the nucleus or cytoplasm of cancer cells and the utility of nuclear or cytoplasmic AEG-1/MTDH/LYRIC to predict the course and prognosis of disease. This chapter provides a comprehensive analysis of the existing literature to emphasize the common and conflicting findings relative to the clinical significance of AEG-1/MTDH/LYRIC in cancer. PMID:23889987

  12. Standardising Responsibility? The Significance of Interstitial Spaces.

    PubMed

    Wickson, Fern; Forsberg, Ellen-Marie

    2015-10-01

    Modern society is characterised by rapid technological development that is often socially controversial and plagued by extensive scientific uncertainty concerning its socio-ecological impacts. Within this context, the concept of 'responsible research and innovation' (RRI) is currently rising to prominence in international discourse concerning science and technology governance. As this emerging concept of RRI begins to be enacted through instruments, approaches, and initiatives, it is valuable to explore what it is coming to mean for and in practice. In this paper we draw attention to a realm that is often backgrounded in the current discussions of RRI but which has a highly significant impact on scientific research, innovation and policy-namely, the interstitial space of international standardization. Drawing on the case of nanoscale sciences and technologies to make our argument, we present examples of how international standards are already entangled in the development of RRI and yet, how the process of international standardization itself largely fails to embody the norms proposed as characterizing RRI. We suggest that although current models for RRI provide a promising attempt to make research and innovation more responsive to societal needs, ethical values and environmental challenges, such approaches will need to encompass and address a greater diversity of innovation system agents and spaces if they are to prove successful in their aims.

  13. Significance of exposure to sidestream tobacco smoke.

    PubMed

    Hoffmann, D; Hoffmann, I

    1987-01-01

    The presence of toxins and carcinogens in ambient air polluted with tobacco smoke is largely due to the sidestream smoke emissions from the smouldering tobacco products. Levels of these toxins and carcinogens in sidestream smoke often exceed their concentrations in mainstream smoke. Dosimetry of tobacco-specific markers of exposure in physiologic fluids suggests that in regard to nicotine--which is the major tobacco alkaloid--exposure of humans to environmental tobacco smoke causes but a few percent of the nicotine levels reached as a result of active inhalation of cigarette mainstream smoke. Yet, this measurement of exposure is not universally applicable to all of the tobacco smoke pollutants in this complex matrix. Existing knowledge of the chemical composition of sidestream smoke and evidence of biological activity of sidestream smoke components suggests that this environmental pollutant has carcinogenic potential. Significance of exposure to environmental tobacco smoke must be evaluated on the basis of the severity of the pollution, the duration of exposure and personal variations in uptake.

  14. Clinical significance of MET in gastric cancer

    PubMed Central

    Inokuchi, Mikito; Otsuki, Sho; Fujimori, Yoshitaka; Sato, Yuya; Nakagawa, Masatoshi; Kojima, Kazuyuki

    2015-01-01

    Chemotherapy has become the global standard treatment for patients with metastatic or unresectable gastric cancer (GC), although outcomes remain unfavorable. Many molecular-targeted therapies inhibiting signaling pathways of various tyrosine kinase receptors have been developed, and monoclonal antibodies targeting human epidermal growth factor receptor 2 or vascular endothelial growth factor receptor 2 have become standard therapy for GC. Hepatocyte growth factor and its receptor, c-MET (MET), play key roles in tumor growth through activated signaling pathways from receptor in GC cells. Genomic amplification of MET leads to the aberrant activation found in GC tumors and is related to survival in patients with GC. This review discusses the clinical significance of MET in GC and examines MET as a potential therapeutic target in patients with GC. Preclinical studies in animal models have shown that MET antibodies or small-molecule MET inhibitors suppress tumor-cell proliferation and tumor progression in MET-amplified GC cells. These drugs are now being evaluated in clinical trials as treatments for metastatic or unresectable GC. PMID:26600931

  15. Taxonomic significance of trichomes micromorphology in cucurbits.

    PubMed

    Ali, Mohammad Ajmal; Al-Hemaid, Fahad M A

    2011-01-01

    Studies on trichomes micromorphology using Scanning Electron Microscope (SEM) were undertaken in 23 species with one variety under 13 genera of the family Cucurbitaceae (viz., Benincasa hispida (Thunb.) Cogn., Citrullus lanatus (Thunb.) Matsum. & Nakai, Cucumis melo var. agrestis Naudin, Cucumis sativus L., Diplocyclos palmatus (L.) C. Jeffrey, Edgaria dargeelingensis C.B. Clarke, Gynostemma burmanicum King ex Chakr., Gynostemma pentaphyllum (Thunb.) Makino, Gynostemma pubescens (Gagnep.) C.Y. Wu, Hemsleya dipterygia Kuang & A.M. Lu, Lagenaria siceraria (Molina) Standl., Luffa acutangula (L.) Roxb., Luffa cylindrica M. Roem., Luffa echinata Roxb., Melothria heterophylla (Lour.) Cogn., Melothria leucocarpa (Blume) Cogn., Melothria maderspatana (L.) Cogn., Sechium edule (Jacq.) Sw., Thladiantha cordifolia (Blume) Cogn., Trichosanthes cucumerina L., T. cucumerina var. anguina (L.) Haines, Trichosanthes dioica Roxb., Trichosanthes lepiniana (Naudin) Cogn. and T. tricuspidata Lour.). The trichomes in the family Cucurbitaceae vary from unicellular to multicellular, conical to elongated, smooth to ridges, with or without flattened disk at base and cyctolithic appendages, thin to thick walled, curved at apices to blunt. Trichomes micromorphology in the family Cucurbitaceae was found significant taxonomically.

  16. Traditional Indian spices and their health significance.

    PubMed

    Krishnaswamy, Kamala

    2008-01-01

    India has been recognized all over the world for spices and medicinal plants. Both exhibit a wide range of physiological and pharmacological properties. Current biomedical efforts are focused on their scientific merits, to provide science-based evidence for the traditional uses and to develop either functional foods or nutraceuticals. The Indian traditional medical systems use turmeric for wound healing, rheumatic disorders, gastrointestinal symptoms, deworming, rhinitis and as a cosmetic. Studies in India have explored its anti-inflammatory, cholekinetic and anti-oxidant potentials with the recent investigations focusing on its preventive effect on precarcinogenic, anti-inflammatory and anti atherosclerotic effects in biological systems both under in vitro and in vivo conditions in animals and humans. Both turmeric and curcumin were found to increase detoxifying enzymes, prevent DNA damage, improve DNA repair, decrease mutations and tumour formation and exhibit antioxidative potential in animals. Limited clinical studies suggest that turmeric can significantly impact excretion of mutagens in urine in smokers and regress precancerous palatal lesions. It reduces DNA adducts and micronuclei in oral epithelial cells. It prevents formation of nitroso compounds both in vivo and in vitro. It delays induced cataract in diabetes and reduces hyperlipidemia in obese rats. Recently several molecular targets have been identified for therapeutic / preventive effects of turmeric. Fenugreek seeds, a rich source of soluble fiber used in Indian cuisine reduces blood glucose and lipids and can be used as a food adjuvant in diabetes. Similarly garlic, onions, and ginger have been found to modulate favourably the process of carcinogenesis.

  17. The significance of gas for offshore operations

    NASA Astrophysics Data System (ADS)

    Sills, G. C.; Wheeler, S. J.

    1992-10-01

    The purpose of this paper is to present an overview of the physical behaviour of a seabed containing undissolved gas in the light of laboratory simulations undertaken at Oxford, Belfast and Sheffield Universities. This physical behaviour is significant for offshore operations in several ways. Gas may exist in high pressure pockets, trapped beneath low permeability clays, which form a blow out hazard during drilling. In fine-grained soils, it exists in voids distributed through the soil, at pressures only a little greater than te ambient water pressure. In this condition, it is unlikely to induced casastrophic failure, but will affect the foundation behaviour through changes in compressibility and strength. In sands, gas may be present in pores between particles, replacing water but not affecting the soil structure. There are common features in all these cases, in that the gas-water interaction occurs through surface tension, acting in menisci whose curvature is affected by the soil particle sizes, shapes and packing. These menisci determine the differences between gas and water pressure that may exist in the soil. Results are presented to show that the compressibility and undrained shear strength of a fine-grained soil are reduced by the presence of gas in a predictable manner, with a similar conclusion for the undrained strength of a gassy sand.

  18. Clinical significance of epithelial-mesenchymal transition

    PubMed Central

    2014-01-01

    The concept of epithelial-mesenchymal transition (EMT), a process where cells change their epithelial towards a mesenchymal phenotype, has gained overwhelming attention especially in the cancer research community. Thousands of scientific reports investigated changes in gene, mRNA and protein expression compatible with EMT and their possible correlation with tumor invasion, metastatic spread or patient prognosis; however, up to now, a proof of clinical significance of the concept is still missing. This review, with a main focus on the role of EMT in tumors, will summarize the basic molecular events underlying EMT including the signaling pathways capable of its induction as well as changes in EMT-associated protein expression and will very briefly touch the role of microRNAs in EMT. We then outline protein markers that are used most frequently for the assessment of EMT in research and diagnostic evaluation of tumor specimens and depict the link between EMT, a cancer stem cell (CSC) phenotype and resistance to conventional antineoplastic therapies. Furthermore, we evaluate a possible correlation between EMT marker expression and patient prognosis as well as current therapeutic concepts targeting the EMT process to slow down or prevent metastatic spread of malignant tumors. PMID:25050175

  19. Significance of duon mutations in cancer genomes

    NASA Astrophysics Data System (ADS)

    Yadav, Vinod Kumar; Smith, Kyle S.; Flinders, Colin; Mumenthaler, Shannon M.; de, Subhajyoti

    2016-06-01

    Functional mutations in coding regions not only affect the structure and function of the protein products, but may also modulate their expression in some cases. This class of mutations, recently dubbed “duon mutations” due to their dual roles, can potentially have major impacts on downstream pathways. However their significance in diseases such as cancer remain unclear. In a survey covering 4606 samples from 19 cancer types, and integrating allelic expression, overall mRNA expression, regulatory motif perturbation, and chromatin signatures in one composite index called REDACT score, we identified potential duon mutations. Several such mutations are detected in known cancer genes in multiple cancer types. For instance a potential duon mutation in TP53 is associated with increased expression of the mutant allelic gene copy, thereby possibly amplifying the functional effects on the downstream pathways. Another potential duon mutation in SF3B1 is associated with abnormal splicing and changes in angiogenesis and matrix degradation related pathways. Our findings emphasize the need to interrogate the mutations in coding regions beyond their obvious effects on protein structures.

  20. Significance of FISH in clinical cytogenetics

    SciTech Connect

    Gopal Rao, V.V.N.; Harris, S.; Roop, H.

    1994-09-01

    Ever since its discovery, FISH technology has become an invaluable adjunct to conventional cytogenetics. FISH has been instrumental in resolving previously unresolved cytogenetic dilemmas. FISH has been used to elucidate complex as well as subtle chromosomal translocations, in detection of microdeletions, to confirm duplications and inversions and to identify marker chromosomes. We report a few selected cases where FISH proved to be invaluable in not only confirming the anomaly, but also in arriving at an accurate diagnosis and appropriate counseling of the patients. These include 3 cases of prenatal and 3 cases of postnatal diagnosis. The results clearly demonstrate the significance of FISH in identifying and interpreting the difficult karyotype in clinical cytogenetics. In addition, FISH has been used to rule out microdeletions in Prader-Willi (16), Angelman (3), Miller-Dieker (7), DiGeorge (4) and Smith-Magenis (1) syndrome patients. Without FISH in the majority of these cases, it would not have been possible to accurately identify the karyotype and interpret the results. Hence, we recommend that FISH be used as a powerful adjunct to conventional cytogenetics in order to arrive at an accurate interpretation of the results but not to replace routine cytogenetic studies.

  1. Phenotypic plasticity: molecular mechanisms and adaptive significance.

    PubMed

    Kelly, Scott A; Panhuis, Tami M; Stoehr, Andrew M

    2012-04-01

    Phenotypic plasticity can be broadly defined as the ability of one genotype to produce more than one phenotype when exposed to different environments, as the modification of developmental events by the environment, or as the ability of an individual organism to alter its phenotype in response to changes in environmental conditions. Not surprisingly, the study of phenotypic plasticity is innately interdisciplinary and encompasses aspects of behavior, development, ecology, evolution, genetics, genomics, and multiple physiological systems at various levels of biological organization. From an ecological and evolutionary perspective, phenotypic plasticity may be a powerful means of adaptation and dramatic examples of phenotypic plasticity include predator avoidance, insect wing polymorphisms, the timing of metamorphosis in amphibians, osmoregulation in fishes, and alternative reproductive tactics in male vertebrates. From a human health perspective, documented examples of plasticity most commonly include the results of exercise, training, and/or dieting on human morphology and physiology. Regardless of the discipline, phenotypic plasticity has increasingly become the target of a plethora of investigations with the methodological approaches utilized ranging from the molecular to whole organsimal. In this article, we provide a brief historical outlook on phenotypic plasticity; examine its potential adaptive significance; emphasize recent molecular approaches that provide novel insight into underlying mechanisms, and highlight examples in fishes and insects. Finally, we highlight examples of phenotypic plasticity from a human health perspective and underscore the use of mouse models as a powerful tool in understanding the genetic architecture of phenotypic plasticity.

  2. Enzymatic DNA oxidation: mechanisms and biological significance.

    PubMed

    Xu, Guo-Liang; Walsh, Colum P

    2014-11-01

    DNA methylation at cytosines (5mC) is a major epigenetic modification involved in the regulation of multiple biological processes in mammals. How methylation is reversed was until recently poorly understood. The family of dioxygenases commonly known as Ten-eleven translocation (Tet) proteins are responsible for the oxidation of 5mC into three new forms, 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC). Current models link Tet-mediated 5mC oxidation with active DNA demethylation. The higher oxidation products (5fC and 5caC) are recognized and excised by the DNA glycosylase TDG via the base excision repair pathway. Like DNA methyltransferases, Tet enzymes are important for embryonic development. We will examine the mechanism and biological significance of Tet-mediated 5mC oxidation in the context of pronuclear DNA demethylation in mouse early embryos. In contrast to its role in active demethylation in the germ cells and early embryo, a number of lines of evidence suggest that the intragenic 5hmC present in brain may act as a stable mark instead. This short review explores mechanistic aspects of TET oxidation activity, the impact Tet enzymes have on epigenome organization and their contribution to the regulation of early embryonic and neuronal development.

  3. Medical Significance of Microorganisms in Spacecraft Environment

    NASA Technical Reports Server (NTRS)

    Pierson, Duane L.; Ott, C. Mark

    2007-01-01

    Microorganisms can spoil food supplies, contaminate drinking water, release noxious volatile compounds, initiate allergic responses, contaminate the environment, and cause infectious diseases. International acceptability limits have been established for bacterial and fungal contaminants in air and on surfaces, and environmental monitoring is conducted to ensure compliance. Allowable levels of microorganism in water and food have also been established. Environmental monitoring of the space shuttle, the Mir, and the ISS have allowed for some general conclusions. Generally, the bacteria found in air and on interior surfaces are largely of human origin such as Staphylococcus spp., Micrococcus spp. Common environmental genera such as Bacillus spp. are the most commonly isolated bacteria from all spacecraft. Yeast species associated with humans such as Candida spp. are commonly found. Aspergillus spp., Penicillium spp., and Cladosporium spp. are the most commonly isolated filamentous fungi. Microbial levels in the environment differ significantly depending upon humidity levels, condensate accumulation, and availability of carbon sources. However, human "normal flora" of bacteria and fungi can result in serious, life-threatening diseases if human immunity is compromised. Disease incidence is expected to increase as mission duration increases.

  4. Erroneous analyses of interactions in neuroscience: a problem of significance.

    PubMed

    Nieuwenhuis, Sander; Forstmann, Birte U; Wagenmakers, Eric-Jan

    2011-08-26

    In theory, a comparison of two experimental effects requires a statistical test on their difference. In practice, this comparison is often based on an incorrect procedure involving two separate tests in which researchers conclude that effects differ when one effect is significant (P < 0.05) but the other is not (P > 0.05). We reviewed 513 behavioral, systems and cognitive neuroscience articles in five top-ranking journals (Science, Nature, Nature Neuroscience, Neuron and The Journal of Neuroscience) and found that 78 used the correct procedure and 79 used the incorrect procedure. An additional analysis suggests that incorrect analyses of interactions are even more common in cellular and molecular neuroscience. We discuss scenarios in which the erroneous procedure is particularly beguiling.

  5. Thresholds for significant decrease in hemodialysis access blood flow.

    PubMed

    Ram, Sunanda J; Nassar, Raja; Sharaf, Rashid; Magnasco, Alberto; Jones, Steven A; Paulson, William D

    2005-01-01

    During hemodialysis access surveillance, referral for evaluation and correction of stenosis is based upon determination that a significant decrease in blood flow (Q) has occurred. However, criteria for determining when a decrease is statistically significant have not yet been established. In this study we established such criteria by analyzing Q variation with the glucose pump test (GPT). We took nine Q measurements in each of 25 patients (18 grafts, 7 fistulas) during three dialysis sessions within a 2-week period (predialysis and during hours 1 and 3). We determined thresholds that define a significant percentage decrease in Q (deltaQ) for various p values. In order to confirm the general applicability of these thresholds, we computed the average within-patient Q variation during the three sessions (computed as a coefficient of variation and referred to as short-term variation). We then determined the relative influences of biological (true) variation and analytical error on short-term variation. We found that deltaQ must be > 33% to be significant at p < 0.05, whereas the threshold is > 17% for p < 0.20. Measuring Q at uniform versus different times during the sessions did not significantly reduce these thresholds. We also found that biological variation was nearly as large as short-term Q variation, whereas analytical error contributed minimally to short-term variation. In conclusion, this study defines thresholds for a significant deltaQ that have wide application in determining access referral for evaluation and correction of stenosis. Selection of a particular threshold should consider the relative importance of avoiding thrombosis versus avoiding unnecessary procedures. If avoiding unnecessary procedures is a priority, then we recommend a threshold of > 33%. These thresholds apply to other methods of measuring Q, provided analytical error is significantly less than biological variation.

  6. The significance of anti-streptokinase antibodies.

    PubMed Central

    Lynch, M; Pentecost, B L; Littler, W A; Stockley, R A

    1994-01-01

    Antibodies to streptokinase (SK) are widespread in the population, but reports of their effect on the action of SK are conflicting. Specific anti-SK IgG was purified from the sera of 10 patients, five with low titres of anti-SK IgG and five with high titres. The effect of increasing specific anti-SK IgG antibodies on the action of SK was evaluated in vitro using a fluorimetric assay for plasmin and by a fibrin plate lysis assay. The inhibition of SK by whole plasma from a further group of patients was also assessed by the fibrin plate assay. There was a positive correlation between the serum antibody concentration and the quantity of specific anti-SK eluted (r = 0.797; P < 0.005). The addition of specific anti-SK IgG caused a dose-related decrease in SK activity (fluorimetric assay r = -0.93; P = 0.02; fibrin plate assay r = -0.98; P < 0.001). The addition of patient plasma to the fibrin plate assay also resulted in decreased lysis, which was dependent upon antibody titre (r = -0.95; P < 0.0001). Significant in vitro reduction of the activity of SK by specific antibody was demonstrated, and this was similar with plasma containing comparable amounts of antibody. The findings suggest that treatment with SK would be unlikely to induce an effective thrombolytic state when antibody titres are high (such as those seen within 2 years of an initial dose of SK). PMID:8004811

  7. Roots: evolutionary origins and biogeochemical significance.

    PubMed

    Raven, J A; Edwards, D

    2001-03-01

    Roots, as organs distinguishable developmentally and anatomically from shoots (other than by occurrence of stomata and sporangia on above-ground organs), evolved in the sporophytes of at least two distinct lineages of early vascular plants during their initial major radiation on land in Early Devonian times (c. 410-395 million years ago). This was some 15 million years after the appearance of tracheophytes and c. 50 million years after the earliest embryophytes of presumed bryophyte affinity. Both groups are known initially only from spores, but from comparative anatomy of extant bryophytes and later Lower Devonian fossils it is assumed that, during these times, below-ground structures (if any) other than true roots fulfilled the functions of anchorage and of water and nutrient acquisition, despite lacking an endodermis (as do the roots of extant Lycopodium spp.). By 375 million years ago root-like structures penetrated almost a metre into the substratum, greatly increasing the volume of mineral matter subject to weathering by the higher than atmospheric CO(2) levels generated by plant and microbial respiration in material with restricted diffusive contact with the atmosphere. Chemical weathering consumes CO(2) in converting silicates into bicarbonate and Si(OH)(4). The CO(2) consumed in weathering ultimately came from atmospheric CO(2) via photosynthesis and respiration; this use of CO(2) probably accounts for most of the postulated 10-fold decrease in atmospheric CO(2) from 400-350 million years ago, with significant effects on shoot evolution. Subsequent evolution of roots has yielded much-branched axes down to 40 microm diameter, a lower limit set by long-distance transport constraints. Finer structures involved in the uptake of nutrients of low diffusivity in soil evolved at least 400 million years ago as arbuscular mycorrhizas or as evaginations of "roots" ("root hairs").

  8. Ignitability test method. II

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1990-01-01

    To determine functional performance of initiating devices, the NASA's Langley Research Center's novel ignitability research on percussion primers has been expanded in 1989 to include measurements of function time, the evaluation of six primer lots (five types), and the determination of the effects of the military cold-temperature requirement of -65 F and primer output closure disks. This test method, a major improvement over the prior primer output test methods, fully met all objectives, while showing a significant amount of ignition variability.

  9. Genetic Testing in Hyperlipidemia.

    PubMed

    Bilen, Ozlem; Pokharel, Yashashwi; Ballantyne, Christie M

    2016-03-01

    Hereditary dyslipidemias are often underdiagnosed and undertreated, yet with significant health implications, most importantly causing preventable premature cardiovascular diseases. The commonly used clinical criteria to diagnose hereditary lipid disorders are specific but are not very sensitive. Genetic testing may be of value in making accurate diagnosis and improving cascade screening of family members, and potentially, in risk assessment and choice of therapy. This review focuses on using genetic testing in the clinical setting for lipid disorders, particularly familial hypercholesterolemia.

  10. Genetic testing in hyperlipidemia.

    PubMed

    Bilen, Ozlem; Pokharel, Yashashwi; Ballantyne, Christie M

    2015-05-01

    Hereditary dyslipidemias are often underdiagnosed and undertreated, yet with significant health implications, most importantly causing preventable premature cardiovascular diseases. The commonly used clinical criteria to diagnose hereditary lipid disorders are specific but are not very sensitive. Genetic testing may be of value in making accurate diagnosis and improving cascade screening of family members, and potentially, in risk assessment and choice of therapy. This review focuses on using genetic testing in the clinical setting for lipid disorders, particularly familial hypercholesterolemia.

  11. Assessing significance in a Markov chain without mixing.

    PubMed

    Chikina, Maria; Frieze, Alan; Pegden, Wesley

    2017-03-14

    We present a statistical test to detect that a presented state of a reversible Markov chain was not chosen from a stationary distribution. In particular, given a value function for the states of the Markov chain, we would like to show rigorously that the presented state is an outlier with respect to the values, by establishing a [Formula: see text] value under the null hypothesis that it was chosen from a stationary distribution of the chain. A simple heuristic used in practice is to sample ranks of states from long random trajectories on the Markov chain and compare these with the rank of the presented state; if the presented state is a [Formula: see text] outlier compared with the sampled ranks (its rank is in the bottom [Formula: see text] of sampled ranks), then this observation should correspond to a [Formula: see text] value of [Formula: see text] This significance is not rigorous, however, without good bounds on the mixing time of the Markov chain. Our test is the following: Given the presented state in the Markov chain, take a random walk from the presented state for any number of steps. We prove that observing that the presented state is an [Formula: see text]-outlier on the walk is significant at [Formula: see text] under the null hypothesis that the state was chosen from a stationary distribution. We assume nothing about the Markov chain beyond reversibility and show that significance at [Formula: see text] is best possible in general. We illustrate the use of our test with a potential application to the rigorous detection of gerrymandering in Congressional districting.

  12. The Significance of Adolescents' Relationships with Significant Others and School Failure

    ERIC Educational Resources Information Center

    Domagala-Zysk, Ewa

    2006-01-01

    This article demonstrates the importance of social support from students' significant others (parents, peers and teachers) in the process of doing well at school. The main focus of the research project was to find correlations between the quality of adolescents' relationships with significant others and their school success or school failure, as…

  13. Analyzing data in aquaculture: practical significance, a new paradigm for determining the importance of results

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Analyzing data and interpreting results is often the most difficult and yet important part of the scientific research process. Currently, aquaculture researchers almost exclusively employ null hypothesis significance testing (NHST), a synthesis of the Fisher test of significance and the Neyman-Pears...

  14. [Diagnosis of parasite infections. Significance of serological examinations].

    PubMed

    Marti, H; Hatz, C F

    2006-08-01

    The attractiveness of tropical and subtropical travel destinations for European tourists as well as the continuous influx of immigrants originating from such areas force the general practitioner to consider the possibility of parasitic infections. Besides the classic microscopic examination for ova and parasites, a serological examination for antibodies has its value especially in the case of an infection with tissue parasites, for an early diagnosis during prepetancy or as a screening test in case of a blood eosinophilia after known exposure risk. The current report highlights possible diagnostic strategies, referring especially to the significance of a serological examination.

  15. Biological significance of soluble IL-2 receptor

    PubMed Central

    Candore, Giuseppina; Cigna, Diego; Colucci, Antonio Tobia; Modica, Maria Assunta

    1993-01-01

    A NUMBER of receptors for growth factors and differentiation antigens have been found to be secreted or released by cells. Following mononuclear cell (MNC) activation and interleukin-2 receptor (IL-2R) expression, a soluble form of the Alpha;-chain of IL-2R (sIL-2R) is released. The sIL-2R has been shown to be present in the culture supernatants of activated MNCs as well as in normal sera and, in higher amounts, in sera from subjects affected by several diseases including neoplastic, infectious and autoimmune ones, and in sera from transplanted patients suffering allograft rejection. The blood sIL-2R levels depend on the number of producing cells and the number of molecules per cell, so that sIL-2R blood values may represent an index of the number and the functional state of producing cells, both normal and neoplastic. Thus, monitoring of the immune system, mostly T-cells and haematological malignancies might be targets for the measurement of sIL-2R. Since many conditions may influence sIL-2R production, little diagnostic use may result from these measurements. However, since blood sIL-2R levels may correlate with disease progression and/or response to therapy, their measurement may be a useful index of activity and extent of disease. The precise biological role of the soluble form of the IL-2R is still a matter of debate. However, we know that increased sIL-2R levels may be observed in association with several immunological abnormalities and that sIL-2R is able to bind IL-2. It is conceivable then that in these conditions the excess sIL-2R released in vivo by activated lymphoid cells or by neoplastic cells may somehow regulate IL-2-dependent processes. On the other hand, it cannot exclude that sIL-2R is a by-product without biological significance. Finally, it is puzzling that in many conditions in which an increase of blood sIL-2R values has been observed, MNCs display a decreased in vitro capacity to produce sIL-2R. These seemingly contrasting findings are

  16. Prognostic Significance of Single Progesterone Receptor Positivity

    PubMed Central

    Fan, Ying; Ding, Xiaoyan; Xu, Binghe; Ma, Fei; Yuan, Peng; Wang, Jiayu; Zhang, Pin; Li, Qing; Luo, Yang

    2015-01-01

    Abstract Single progesterone receptor positive (PgR+), especially in form of ER−/PgR+/HER2−, is a nonnegligible phenomenon. Little is known about the characteristics and the role of single PgR positive in this phenotype. Therefore, we explore the significance of single PgR positivity by comparing ER−/PgR+/HER2− breast cancers with triple negative breast cancers (TNBCs). Three thousand nine hundred sixty-six cases of primary invasive breast carcinoma operated consecutively from January 2005 to May 2008 in Cancer Hospital, Chinese Academy of Medical Sciences were examined. Two hundred forty (6%) cases were identified as ER−/PgR+/HER2− breast cancers and 348 (8.8%) cases as TNBCs. Clinicopathological characteristics and survivals were analyzed respectively and then compared between 2 subtypes. Compared with patients with TNBCs, ER−/PgR+/HER2− tumor tended to have lower tumor grade (Grade 3: 45.7% vs. 37.5%, P = 0.051) and smaller tumor size (P = 0.036). However, no differences were found between ER−/PgR+/HER2− and TNBC patients in relapse-free survival (RFS) and OS. The 5-year RFS rates were 80.7% and 77.4%, respectively (P = 0.330) and the 5-year OS rates were 88.0% and 85.2%, respectively (P = 0.290). ER−/PgR+/HER2− patients receiving adjuvant endocrine treatment had better RFS (P = 0.016) and overall survival (OS) (P < 0.0001) than patients receiving no endocrine therapy. This exclusive analysis of patients with ER−/PgR+/HER2− breast cancers showed that this subtype exhibited an aggressive behavior as TNBC, suggesting that it should also be regarded as biologically distinctive group and single PgR positive itself is not a good prognostic factor. However, adjuvant endocrine therapy could still benefit this group of patients. Further investigations should be done to elucidate the underlying mechanism. PMID:26579819

  17. Inverse agonism and its therapeutic significance

    PubMed Central

    Khilnani, Gurudas; Khilnani, Ajeet Kumar

    2011-01-01

    A large number of G-protein-coupled receptors (GPCRs) show varying degrees of basal or constitutive activity. This constitutive activity is usually minimal in natural receptors but is markedly observed in wild type and mutated (naturally or induced) receptors. According to conventional two-state drug receptor interaction model, binding of a ligand may initiate activity (agonist with varying degrees of positive intrinsic activity) or prevent the effect of an agonist (antagonist with zero intrinsic activity). Inverse agonists bind with the constitutively active receptors, stabilize them, and thus reduce the activity (negative intrinsic activity). Receptors of many classes (α-and β-adrenergic, histaminergic, GABAergic, serotoninergic, opiate, and angiotensin receptors) have shown basal activity in suitable in vitro models. Several drugs that have been conventionally classified as antagonists (β-blockers, antihistaminics) have shown inverse agonist effects on corresponding constitutively active receptors. Nearly all H1 and H2 antihistaminics (antagonists) have been shown to be inverse agonists. Among the β-blockers, carvedilol and bucindolol demonstrate low level of inverse agonism as compared to propranolol and nadolol. Several antipsychotic drugs (D2 receptors antagonist), antihypertensive (AT1 receptor antagonists), antiserotoninergic drugs and opioid antagonists have significant inverse agonistic activity that contributes partly or wholly to their therapeutic value. Inverse agonism may also help explain the underlying mechanism of beneficial effects of carvedilol in congestive failure, naloxone-induced withdrawal syndrome in opioid dependence, clozapine in psychosis, and candesartan in cardiac hypertrophy. Understanding inverse agonisms has paved a way for newer drug development. It is now possible to develop agents, which have only desired therapeutic value and are devoid of unwanted adverse effect. Pimavanserin (ACP-103), a highly selective 5-HT2A inverse

  18. Sensitivity testing and analysis

    SciTech Connect

    Neyer, B.T.

    1991-01-01

    New methods of sensitivity testing and analysis are proposed. The new test method utilizes Maximum Likelihood Estimates to pick the next test level in order to maximize knowledge of both the mean, {mu}, and the standard deviation, {sigma} of the population. Simulation results demonstrate that this new test provides better estimators (less bias and smaller variance) of both {mu} and {sigma} than the other commonly used tests (Probit, Bruceton, Robbins-Monro, Langlie). A new method of analyzing sensitivity tests is also proposed. It uses the Likelihood Ratio Test to compute regions of arbitrary confidence. It can calculate confidence regions, for {mu}, {sigma}, and arbitrary percentiles. Unlike presently used methods, such as the program ASENT which is based on the Cramer-Rao theorem, it can analyze the results of all sensitivity tests, and it does not significantly underestimate the size of the confidence regions. The new test and analysis methods will be explained and compared to the presently used methods. 19 refs., 12 figs.

  19. Human-directed social behaviour in dogs shows significant heritability.

    PubMed

    Persson, M E; Roth, L S V; Johnsson, M; Wright, D; Jensen, P

    2015-04-01

    Through domestication and co-evolution with humans, dogs have developed abilities to attract human attention, e.g. in a manner of seeking assistance when faced with a problem solving task. The aims of this study were to investigate within breed variation in human-directed contact seeking in dogs and to estimate its genetic basis. To do this, 498 research beagles, bred and kept under standardized conditions, were tested in an unsolvable problem task. Contact seeking behaviours recorded included both eye contact and physical interactions. Behavioural data was summarized through a principal component analysis, resulting in four components: test interactions, social interactions, eye contact and physical contact. Females scored significantly higher on social interactions and physical contact and age had an effect on eye contact scores. Narrow sense heritabilities (h(2) ) of the two largest components were estimated at 0.32 and 0.23 but were not significant for the last two components. These results show that within the studied dog population, behavioural variation in human-directed social behaviours was sex dependent and that the utilization of eye contact seeking increased with age and experience. Hence, heritability estimates indicate a significant genetic contribution to the variation found in human-directed social interactions, suggesting that social skills in dogs have a genetic basis, but can also be shaped and enhanced through individual experiences. This research gives the opportunity to further investigate the genetics behind dogs' social skills, which could also play a significant part into research on human social disorders such as autism.

  20. Alzheimer's Disease Variants with the Genome-Wide Significance are Significantly Enriched in Immune Pathways and Active in Immune Cells.

    PubMed

    Jiang, Qinghua; Jin, Shuilin; Jiang, Yongshuai; Liao, Mingzhi; Feng, Rennan; Zhang, Liangcai; Liu, Guiyou; Hao, Junwei

    2017-01-01

    The existing large-scale genome-wide association studies (GWAS) datasets provide strong support for investigating the mechanisms of Alzheimer's disease (AD) by applying multiple methods of pathway analysis. Previous studies using selected single nucleotide polymorphisms (SNPs) with several thresholds of nominal significance for pathway analysis determined that the threshold chosen for SNPs can reflect the disease model. Presumably, then, pathway analysis with a stringent threshold to define "associated" SNPs would test the hypothesis that highly associated SNPs are enriched in one or more particular pathways. Here, we selected 599 AD variants (P < 5.00E-08) to investigate the pathways in which these variants are enriched and the cell types in which these variants are active. Our results showed that AD variants are significantly enriched in pathways of the immune system. Further analysis indicated that AD variants are significantly enriched for enhancers in a number of cell types, in particular the B-lymphocyte, which is the most substantially enriched cell type. This cell type maintains its dominance among the strongest enhancers. AD SNPs also display significant enrichment for DNase in 12 cell types, among which the top 6 significant signals are from immune cell types, including 4 B cells (top 4 significant signals) and CD14+ and CD34+ cells. In summary, our results show that these AD variants with P < 5.00E-08 are significantly enriched in pathways of the immune system and active in immune cells. To a certain degree, the genetic predisposition for development of AD is rooted in the immune system, rather than in neuronal cells.

  1. Finding significantly connected voxels based on histograms of connection strengths

    NASA Astrophysics Data System (ADS)

    Kasenburg, Niklas; Pedersen, Morten Vester; Darkner, Sune

    2016-03-01

    We explore a new approach for structural connectivity based segmentations of subcortical brain regions. Connectivity based segmentations are usually based on fibre connections from a seed region to predefined target regions. We present a method for finding significantly connected voxels based on the distribution of connection strengths. Paths from seed voxels to all voxels in a target region are obtained from a shortest-path tractography. For each seed voxel we approximate the distribution with a histogram of path scores. We hypothesise that the majority of estimated connections are false-positives and that their connection strength is distributed differently from true-positive connections. Therefore, an empirical null-distribution is defined for each target region as the average normalized histogram over all voxels in the seed region. Single histograms are then tested against the corresponding null-distribution and significance is determined using the false discovery rate (FDR). Segmentations are based on significantly connected voxels and their FDR. In this work we focus on the thalamus and the target regions were chosen by dividing the cortex into a prefrontal/temporal zone, motor zone, somatosensory zone and a parieto-occipital zone. The obtained segmentations consistently show a sparse number of significantly connected voxels that are located near the surface of the anterior thalamus over a population of 38 subjects.

  2. Measuring the significance of community structure in complex networks

    NASA Astrophysics Data System (ADS)

    Hu, Yanqing; Nie, Yuchao; Yang, Hua; Cheng, Jie; Fan, Ying; di, Zengru

    2010-12-01

    Many complex systems can be represented as networks, and separating a network into communities could simplify functional analysis considerably. Many approaches have recently been proposed to detect communities, but a method to determine whether the detected communities are significant is still lacking. In this paper, an index to evaluate the significance of communities in networks is proposed based on perturbation of the network. In contrast to previous approaches, the network is disturbed gradually, and the index is defined by integrating all of the similarities between the community structures before and after perturbation. Moreover, by taking the null model into account, the index eliminates scale effects. Thus, it can evaluate and compare the significance of communities in different networks. The method has been tested in many artificial and real-world networks. The results show that the index is in fact independent of the size of the network and the number of communities. With this approach, clear communities are found to always exist in social networks, but significant communities cannot be found in protein interactions and metabolic networks.

  3. Testing technology

    SciTech Connect

    Not Available

    1993-10-01

    This bulletin from Sandia National Laboratories presents current research highlights in testing technology. Ion microscopy offers new nondestructive testing technique that detects high resolution invisible defects. An inexpensive thin-film gauge checks detonators on centrifuge. Laser trackers ride the range and track helicopters at low-level flights that could not be detected by radar. Radiation transport software predicts electron/photon effects via cascade simulation. Acoustic research in noise abatement will lead to quieter travelling for Bay Area Rapid Transport (BART) commuters.

  4. Olive oil supplemented with menaquinone-7 significantly affects osteocalcin carboxylation.

    PubMed

    Brugè, Francesca; Bacchetti, Tiziana; Principi, Federica; Littarru, Gian Paolo; Tiano, Luca

    2011-10-01

    Menaquinone-7 (MK-7), a member of the vitamin K2 family, performs several functions, all related to its recognised effect on post-translational carboxylation of certain protein-bound glutamate residues. Due to its lipophilic structure MK-7 is soluble in olive oil, so the aim of the present study was to test whether extra-virgin (EV) olive oil enriched with MK-7 significantly increases MK-7 plasma levels and has an effect on osteocalcin and its carboxylation status. Healthy young volunteers (n 12) were administered 20 ml EV olive oil per d for 2 weeks, followed by 2 weeks of the same amount of olive oil enriched with 45 μg and then 90 μg MK-7, with an appropriate washout time in between. Blood was collected and plasma separated in each phase of the study. We found that integration of the diet with EV olive oil alone did not produce any significant variation of MK-7 plasma levels compared with baseline. Supplementation with MK-7-enriched olive oil resulted in a significant and dose-dependent increase in plasma levels. The high dose also significantly increased carboxylated osteocalcin (cOC) and decreased undercarboxylated osteocalcin (ucOC) plasma levels, resulting in a significant increase in the cOC:ucOC ratio. A significant correlation was also found between percentage variation of plasma cOCA:ucOC ratio and increase in plasma MK-7 levels. We conclude that regular consumption of MK-7-enriched olive oil may constitute a valid approach in order to preserve some key biochemical mechanisms controlling bone mineralisation.

  5. Student Perceptions of Computerized Tests

    ERIC Educational Resources Information Center

    Pino-Silva, Juan

    2008-01-01

    The challenge to test small groups by means of microcomputers demands appropriate software design and sound test design. To comply with this demand, students' beliefs or perceptions on the advantages and disadvantages of a computerized test were tapped. Overall, self-reported advantages outnumbered disadvantages to a significant degree. This was…

  6. Estrogen Test

    MedlinePlus

    ... and Men Estradiol (E2) and/or estrone (E1) testing in boys and men may be ordered when: A boy has delayed puberty, characterized by delayed development of muscle mass, lack of deepening of the voice or growth of body hair, slow or delayed growth of testicles and penis ...

  7. Homocysteine Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  8. Phosphorus Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  9. Chymotrypsin Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  10. AMA Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  11. TORCH Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  12. Gonorrhea Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  13. Triglycerides Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  14. Electrolytes Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  15. Myoglobin Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  16. Toxoplasmosis Testing

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  17. Prealbumin Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  18. Serotonin Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  19. Lead Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  20. Prolactin Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  1. Prenatal Tests

    MedlinePlus

    ... baby with a birth defect — especially heart or genetic problems are carrying more than one baby have high blood pressure , diabetes , lupus , heart disease, ... A Week-by-Week Pregnancy Calendar Birth Plans Genetic Testing Staying Healthy During ... Having a Healthy Pregnancy Contact Us Print ...

  2. Rotational testing.

    PubMed

    Furman, J M

    2016-01-01

    The natural stimulus for the semicircular canals is rotation of the head, which also might stimulate the otolith organs. Vestibular stimulation usually induces eye movements via the vestibulo-ocular reflex (VOR). The orientation of the subject with respect to the axis of rotation and the orientation of the axis of rotation with respect to gravity together determine which labyrinthine receptors are stimulated for particular motion trajectories. Rotational testing usually includes the measurement of eye movements via a video system but might use a subject's perception of motion. The most common types of rotational testing are whole-body computer-controlled sinusoidal or trapezoidal stimuli during earth-vertical axis rotation (EVAR), which stimulates primarily the horizontal semicircular canals bilaterally. Recently, manual impulsive rotations, known as head impulse testing (HIT), have been developed to assess individual horizontal semicircular canals. Most types of rotational stimuli are not used routinely in the clinical setting but may be used in selected research environments. This chapter will discuss clinically relevant rotational stimuli and several types of rotational testing that are used primarily in research settings.

  3. Mono Test

    MedlinePlus

    ... services. Advertising & Sponsorship: Policy | Opportunities PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be ... Mononucleosis (Mono) Test Share this page: Was this page helpful? Also ...

  4. A Tutorial on Hunting Statistical Significance by Chasing N.

    PubMed

    Szucs, Denes

    2016-01-01

    There is increasing concern about the replicability of studies in psychology and cognitive neuroscience. Hidden data dredging (also called p-hacking) is a major contributor to this crisis because it substantially increases Type I error resulting in a much larger proportion of false positive findings than the usually expected 5%. In order to build better intuition to avoid, detect and criticize some typical problems, here I systematically illustrate the large impact of some easy to implement and so, perhaps frequent data dredging techniques on boosting false positive findings. I illustrate several forms of two special cases of data dredging. First, researchers may violate the data collection stopping rules of null hypothesis significance testing by repeatedly checking for statistical significance with various numbers of participants. Second, researchers may group participants post hoc along potential but unplanned independent grouping variables. The first approach 'hacks' the number of participants in studies, the second approach 'hacks' the number of variables in the analysis. I demonstrate the high amount of false positive findings generated by these techniques with data from true null distributions. I also illustrate that it is extremely easy to introduce strong bias into data by very mild selection and re-testing. Similar, usually undocumented data dredging steps can easily lead to having 20-50%, or more false positives.

  5. A Tutorial on Hunting Statistical Significance by Chasing N

    PubMed Central

    Szucs, Denes

    2016-01-01

    There is increasing concern about the replicability of studies in psychology and cognitive neuroscience. Hidden data dredging (also called p-hacking) is a major contributor to this crisis because it substantially increases Type I error resulting in a much larger proportion of false positive findings than the usually expected 5%. In order to build better intuition to avoid, detect and criticize some typical problems, here I systematically illustrate the large impact of some easy to implement and so, perhaps frequent data dredging techniques on boosting false positive findings. I illustrate several forms of two special cases of data dredging. First, researchers may violate the data collection stopping rules of null hypothesis significance testing by repeatedly checking for statistical significance with various numbers of participants. Second, researchers may group participants post hoc along potential but unplanned independent grouping variables. The first approach ‘hacks’ the number of participants in studies, the second approach ‘hacks’ the number of variables in the analysis. I demonstrate the high amount of false positive findings generated by these techniques with data from true null distributions. I also illustrate that it is extremely easy to introduce strong bias into data by very mild selection and re-testing. Similar, usually undocumented data dredging steps can easily lead to having 20–50%, or more false positives. PMID:27713723

  6. Prevalence and clinical significance of rare antinuclear antibody patterns.

    PubMed

    Vermeersch, Pieter; Bossuyt, Xavier

    2013-08-01

    While some of the more frequent antinuclear (auto)antibodies (ANA) patterns such as homogenous nuclear staining have been extensively studied, the prevalence and clinical significance of rare antinuclear antibody patterns are not well understood. For the purpose of this review, we defined rare patterns as patterns occurring in less than 1% of patients that test positive on indirect immunofluorescence. The prevalence of different ANA patterns was determined in 68,128 consecutive patients who attended the outpatient clinic or were hospitalized at the University Hospitals Leuven over a 14-year period (1998-2011). To avoid bias, we only included the first sample for each patient and patients who tested positive in the period 1980-1997 were excluded. There were 9268 patients who tested positive for ANA. With the exception of the clinical association of anti-multiple nuclear dots (at higher titers) and anti-nuclear envelope autoantibodies with autoimmune liver disease, there was no good clinical association of rare ANA patterns with the diagnosis of auto-immune disorders. The most important non-autoimmune cause of rare ANA patterns was carcinoma, particularly in patients with rare cell-cycle related ANAs.

  7. Assessing statistical significance in multivariable genome wide association analysis

    PubMed Central

    Buzdugan, Laura; Kalisch, Markus; Navarro, Arcadi; Schunk, Daniel; Fehr, Ernst; Bühlmann, Peter

    2016-01-01

    Motivation: Although Genome Wide Association Studies (GWAS) genotype a very large number of single nucleotide polymorphisms (SNPs), the data are often analyzed one SNP at a time. The low predictive power of single SNPs, coupled with the high significance threshold needed to correct for multiple testing, greatly decreases the power of GWAS. Results: We propose a procedure in which all the SNPs are analyzed in a multiple generalized linear model, and we show its use for extremely high-dimensional datasets. Our method yields P-values for assessing significance of single SNPs or groups of SNPs while controlling for all other SNPs and the family wise error rate (FWER). Thus, our method tests whether or not a SNP carries any additional information about the phenotype beyond that available by all the other SNPs. This rules out spurious correlations between phenotypes and SNPs that can arise from marginal methods because the ‘spuriously correlated’ SNP merely happens to be correlated with the ‘truly causal’ SNP. In addition, the method offers a data driven approach to identifying and refining groups of SNPs that jointly contain informative signals about the phenotype. We demonstrate the value of our method by applying it to the seven diseases analyzed by the Wellcome Trust Case Control Consortium (WTCCC). We show, in particular, that our method is also capable of finding significant SNPs that were not identified in the original WTCCC study, but were replicated in other independent studies. Availability and implementation: Reproducibility of our research is supported by the open-source Bioconductor package hierGWAS. Contact: peter.buehlmann@stat.math.ethz.ch Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27153677

  8. Sixteen-Day Bedrest Significantly Increases Plasma Colloid Osmotic Pressure

    NASA Technical Reports Server (NTRS)

    Hargens, Alan R.; Hsieh, S. T.; Murthy, G.; Ballard, R. E.; Convertino, V. A.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    Upon exposure to microgravity, astronauts lose up to 10% of their total plasma volume, which may contribute to orthostatic intolerance after space flight. Because plasma colloid osmotic pressure (COP) is a primary factor maintaining plasma volume, our objective was to measure time course changes in COP during microgravity simulated by 6 deg. head-down tilt (HDT). Seven healthy male subjects (30-55 years of age) were placed in HDT for 16 days. For the purpose of another study, three of the seven subjects were chosen to exercise on a cycle ergometer on day 16. Blood samples were drawn immediately before bedrest on day 14 of bedrest, 18-24 hours following exercise while all subjects were still in HDT and 1 hour following bedrest termination. Plasma COP was measured in all 20 microliter EDTA-treated samples using an osmometer fitted with a PM 30 membrane. Data were analyzed with paired and unpaired t-tests. Plasma COP on day 14 of bedrest (29.9 +/- 0.69 mmHg) was significantly higher (p less than 0.005) than the control, pre-bedrest value (23.1 +/- 0.76 mmHg). At one hour of upright recovery after HDT, plasma COP remained significantly elevated (exercise: 26.9 +/- 0.87 mmHg; no exercise: 26.3 +/- 0.85 mmHg). Additionally, exercise had no significant effect on plasma COP 18-24 hours following exercise (exercise: 27.8 +/- 1.09 mmHg; no exercise: 27.1 +/- 0.78 mmHg). Our results demonstrate that plasma COP increases significantly with microgravity simulated by HDT. However, preliminary results indicate exercise during HDT does not significantly affect plasma COP.

  9. Microgrid Testing

    SciTech Connect

    Shirazi, M.; Kroposki, B.

    2012-01-01

    With the publication of IEEE 1574.4 Guide for Design, Operation, and Integration of Distributed Resource Island Systems with Electric Power Systems, there is an increasing amount of attention on not only the design and operations of microgrids, but also on the proper operation and testing of these systems. This standard provides alternative approaches and good practices for the design, operation, and integration of microgrids. This includes the ability to separate from and reconnect to part of the utility grid while providing power to the islanded power system. This presentation addresses the industry need to develop standardized testing and evaluation procedures for microgrids in order to assure quality operation in the grid connected and islanded modes of operation.

  10. test title

    DTIC Science & Technology

    2015-12-01

    expectations by experimenters and testbed system managers, with minor automation from the testbed. We include design hooks for the system to use...scripting environment whose syntax enables specification of control flows that depend on controlled program outputs, thus automating system testing...Homeland Security and the Space and Naval Warfare Systems Center, San Diego, under contract No. N66001-07-C-2001, and by the National Science

  11. Earthquake Testing

    NASA Technical Reports Server (NTRS)

    1979-01-01

    During NASA's Apollo program, it was necessary to subject the mammoth Saturn V launch vehicle to extremely forceful vibrations to assure the moonbooster's structural integrity in flight. Marshall Space Flight Center assigned vibration testing to a contractor, the Scientific Services and Systems Group of Wyle Laboratories, Norco, California. Wyle-3S, as the group is known, built a large facility at Huntsville, Alabama, and equipped it with an enormously forceful shock and vibration system to simulate the liftoff stresses the Saturn V would encounter. Saturn V is no longer in service, but Wyle-3S has found spinoff utility for its vibration facility. It is now being used to simulate earthquake effects on various kinds of equipment, principally equipment intended for use in nuclear power generation. Government regulations require that such equipment demonstrate its ability to survive earthquake conditions. In upper left photo, Wyle3S is preparing to conduct an earthquake test on a 25ton diesel generator built by Atlas Polar Company, Ltd., Toronto, Canada, for emergency use in a Canadian nuclear power plant. Being readied for test in the lower left photo is a large circuit breaker to be used by Duke Power Company, Charlotte, North Carolina. Electro-hydraulic and electro-dynamic shakers in and around the pit simulate earthquake forces.

  12. Testing Understanding and Understanding Testing.

    ERIC Educational Resources Information Center

    Pedersen, Jean; Ross, Peter

    1985-01-01

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

  13. The Prostate Health Index Selectively Identifies Clinically Significant Prostate Cancer

    PubMed Central

    Loeb, Stacy; Sanda, Martin G.; Broyles, Dennis L.; Shin, Sanghyuk S.; Bangma, Chris H.; Wei, John T.; Partin, Alan W.; Klee, George G.; Slawin, Kevin M.; Marks, Leonard S.; van Schaik, Ron H. N.; Chan, Daniel W.; Sokoll, Lori J.; Cruz, Amabelle B.; Mizrahi, Isaac A.; Catalona, William J.

    2015-01-01

    Purpose The Prostate Health Index (phi) is a new test combining total, free and [-2]proPSA into a single score. It was recently approved by the FDA and is now commercially available in the U.S., Europe and Australia. We investigate whether phi improves specificity for detecting clinically significant prostate cancer and can help reduce prostate cancer over diagnosis. Materials and Methods From a multicenter prospective trial we identified 658 men age 50 years or older with prostate specific antigen 4 to 10 ng/ml and normal digital rectal examination who underwent prostate biopsy. In this population we compared the performance of prostate specific antigen, % free prostate specific antigen, [-2]proPSA and phi to predict biopsy results and, specifically, the presence of clinically significant prostate cancer using multiple criteria. Results The Prostate Health Index was significantly higher in men with Gleason 7 or greater and “Epstein significant” cancer. On receiver operating characteristic analysis phi had the highest AUC for overall cancer (AUCs phi 0.708, percent free prostate specific antigen 0.648, [-2]proPSA 0.550 and prostate specific antigen 0.516), Gleason 7 or greater (AUCs phi 0.707, percent free prostate specific antigen 0.661, [-2]proPSA 0.558, prostate specific antigen 0.551) and significant cancer (AUCs phi 0.698, percent free prostate specific antigen 0.654, [-2]proPSA 0.550, prostate specific antigen 0.549). At the 90% sensitivity cut point for phi (a score less than 28.6) 30.1% of patients could have been spared an unnecessary biopsy for benign disease or insignificant prostate cancer compared to 21.7% using percent free prostate specific antigen. Conclusions The new phi test outperforms its individual components of total, free and [-2]proPSA for the identification of clinically significant prostate cancer. Phi may be useful as part of a multivariable approach to reduce prostate biopsies and over diagnosis. PMID:25463993

  14. Semantic significance: a new measure of feature salience.

    PubMed

    Montefinese, Maria; Ambrosini, Ettore; Fairfield, Beth; Mammarella, Nicola

    2014-04-01

    According to the feature-based model of semantic memory, concepts are described by a set of semantic features that contribute, with different weights, to the meaning of a concept. Interestingly, this theoretical framework has introduced numerous dimensions to describe semantic features. Recently, we proposed a new parameter to measure the importance of a semantic feature for the conceptual representation-that is, semantic significance. Here, with speeded verification tasks, we tested the predictive value of our index and investigated the relative roles of conceptual and featural dimensions on the participants' performance. The results showed that semantic significance is a good predictor of participants' verification latencies and suggested that it efficiently captures the salience of a feature for the computation of the meaning of a given concept. Therefore, we suggest that semantic significance can be considered an effective index of the importance of a feature in a given conceptual representation. Moreover, we propose that it may have straightforward implications for feature-based models of semantic memory, as an important additional factor for understanding conceptual representation.

  15. The adaptive significance of adult neurogenesis: an integrative approach

    PubMed Central

    Konefal, Sarah; Elliot, Mick; Crespi, Bernard

    2013-01-01

    Adult neurogenesis in mammals is predominantly restricted to two brain regions, the dentate gyrus (DG) of the hippocampus and the olfactory bulb (OB), suggesting that these two brain regions uniquely share functions that mediate its adaptive significance. Benefits of adult neurogenesis across these two regions appear to converge on increased neuronal and structural plasticity that subserves coding of novel, complex, and fine-grained information, usually with contextual components that include spatial positioning. By contrast, costs of adult neurogenesis appear to center on potential for dysregulation resulting in higher risk of brain cancer or psychological dysfunctions, but such costs have yet to be quantified directly. The three main hypotheses for the proximate functions and adaptive significance of adult neurogenesis, pattern separation, memory consolidation, and olfactory spatial, are not mutually exclusive and can be reconciled into a simple general model amenable to targeted experimental and comparative tests. Comparative analysis of brain region sizes across two major social-ecological groups of primates, gregarious (mainly diurnal haplorhines, visually-oriented, and in large social groups) and solitary (mainly noctural, territorial, and highly reliant on olfaction, as in most rodents) suggest that solitary species, but not gregarious species, show positive associations of population densities and home range sizes with sizes of both the hippocampus and OB, implicating their functions in social-territorial systems mediated by olfactory cues. Integrated analyses of the adaptive significance of adult neurogenesis will benefit from experimental studies motivated and structured by ecologically and socially relevant selective contexts. PMID:23882188

  16. Significant Conversations and Significant Networks--Exploring the Backstage of the Teaching Arena

    ERIC Educational Resources Information Center

    Roxa, Torgny; Martensson, Katarina

    2009-01-01

    This article presents an inquiry into conversations that academic teachers have about teaching. The authors investigated to whom they talk and the forms that these conversations take. The findings indicate that most teachers rely on a small number of significant others for conversations that are characterised by their privacy, by mutual trust and…

  17. Significant Life Experiences and Environmental Justice: Positionality and the Significance of Negative Social/Environmental Experiences

    ERIC Educational Resources Information Center

    Ceaser, Donovon

    2015-01-01

    Significant life experiences (SLE) research has been criticized for a disproportionate focus on privileged groups and positive experiences. In this paper, I use textual analysis to examine the SLEs within the Environmental Justice (EJ) literature. Theoretically, I blend feminist theory, the sociology of disaster, and research on EJ motives for…

  18. Optical testing of condoms.

    PubMed

    Smith, S R; Lowrance, J L; Tessarotto, L A

    1999-01-01

    use of the new optical test techniques could have prevented an unexpectedly large number of condoms with significant pinhole and thin region defects from reaching the public. Optical test systems could be used to support either regulatory, quality assurance, or clinical field testing of latex or nonlatex condoms. Due to their high rate capability and level of automation, they could also be applied to 100% screening testing in the factory. The new test techniques could also be used to detect defects in a wide range of other thin sheets and membranes.

  19. Prognostic significance of tumour stroma ratio in inflammatory breast cancer.

    PubMed

    Downey, Candice L; Thygesen, Helene H; Sharma, Nisha; Shaaban, Abeer M

    2015-01-01

    Tumour stroma ratio (TSR) is emerging as an important prognostic indicator in cancer. We have previously shown TSR to be prognostic in oestrogen receptor positive breast cancer. Its role in inflammatory breast cancer, a rare but aggressive form of breast cancer, has not been identified. Here we aimed to determine the prognostic significance of TSR in a cohort of patients with inflammatory breast carcinoma. TSR was measured by point counting virtual H&E stained tissue sections in 45 inflammatory breast cancer cases. The whole tumour area was sampled. Optimum cut-offs to distinguish high and low TSR was determined by log-rank test. The relationship of TSR to overall survival and disease-free survival (DFS) was analysed alongside multivariate analysis. The optimal cut-offs between high and low TSR were determined to be 31% for OS and 46% for DFS. There was no significant difference in OS (p = 0.53) nor DFS (p = 0.66) between high and low TSR groups. Multivariate analysis did not demonstrate any new trends, within the limits of a small data sample. A significant correlation was found between pathological response to neoadjuvant chemotherapy and survival (p = 0.008). There is no evidence that TSR has prognostic significance in inflammatory breast cancer. When compared with published data in non-inflammatory breast carcinoma, this supports the view that differences in stromal biology exist between tumour types and highlights the importance of considering this when interpreting the prognostic value of TSR. However, these findings must be interpreted in the light of the small sample size.

  20. Tauwer Test

    SciTech Connect

    Russ, James; Iori, Maurizio; Ronzhin, Anatoly; /Fermilab

    2011-01-24

    TAUWER is a proposed astroparticle experiment to detect ultrahigh energy TAU neutrinos, using detector towers arrayed on a mountainside looking down into a valley. This test is to study the possibility of replacing Hamamatsu miniature PMTs with SiPMs for readout by determining the response of scintillation detectors with SiPM readout to low energy electrons, 2 GeV or lower, as the beam will provide. The detector itself is a compact package shown in the picture on the cover. it was used in a parasitic test beam run on December 15, 2010, to compare the relative timing of the signals from three counters for MIPs. The only change for this new run is the insertion of 1.5 cm of Pb in front of counter 2 or counter 3 during most of the running. The experiment takes some electron data without Pb for calibration purposes. The apparatus will be mounted on the moving table in MT6.2B.