WorldWideScience

Sample records for method repeated measures

  1. Methods for analysing cardiovascular studies with repeated measures

    NARCIS (Netherlands)

    Cleophas, T. J.; Zwinderman, A. H.; van Ouwerkerk, B. M.

    2009-01-01

    Background. Repeated measurements in a single subject are generally more similar than unrepeated measurements in different subjects. Unrepeated analyses of repeated data cause underestimation of the treatment effects. Objective. To review methods adequate for the analysis of cardiovascular studies

  2. Measurement System Analyses - Gauge Repeatability and Reproducibility Methods

    Science.gov (United States)

    Cepova, Lenka; Kovacikova, Andrea; Cep, Robert; Klaput, Pavel; Mizera, Ondrej

    2018-02-01

    The submitted article focuses on a detailed explanation of the average and range method (Automotive Industry Action Group, Measurement System Analysis approach) and of the honest Gauge Repeatability and Reproducibility method (Evaluating the Measurement Process approach). The measured data (thickness of plastic parts) were evaluated by both methods and their results were compared on the basis of numerical evaluation. Both methods were additionally compared and their advantages and disadvantages were discussed. One difference between both methods is the calculation of variation components. The AIAG method calculates the variation components based on standard deviation (then a sum of variation components does not give 100 %) and the honest GRR study calculates the variation components based on variance, where the sum of all variation components (part to part variation, EV & AV) gives the total variation of 100 %. Acceptance of both methods among the professional society, future use, and acceptance by manufacturing industry were also discussed. Nowadays, the AIAG is the leading method in the industry.

  3. Modeling intraindividual variability with repeated measures data methods and applications

    CERN Document Server

    Hershberger, Scott L

    2013-01-01

    This book examines how individuals behave across time and to what degree that behavior changes, fluctuates, or remains stable.It features the most current methods on modeling repeated measures data as reported by a distinguished group of experts in the field. The goal is to make the latest techniques used to assess intraindividual variability accessible to a wide range of researchers. Each chapter is written in a ""user-friendly"" style such that even the ""novice"" data analyst can easily apply the techniques.Each chapter features:a minimum discussion of mathematical detail;an empirical examp

  4. Repeatability of oral fluid collection methods for THC measurement

    NARCIS (Netherlands)

    Houwing, Sjoerd; Smink, Beitske E.; Legrand, Sara-Ann; Mathijssen, Rene P. M.; Verstraete, Alain G.; Brookhuis, Karel A.

    2012-01-01

    Study objectives: To determine the influence of sample collection for two different collection methods on THC concentrations and to compare THC concentrations collected by both methods. Methods: A total of 136 pairs of oral fluid samples from subjects who had recently smoked Cannabis were obtained

  5. Repeatability of oral fluid collection methods for THC measurement.

    NARCIS (Netherlands)

    Houwing, S. Smink, B.E. Legrand, S.-A. Mathijssen, M.P.M. Verstraete, A.G. & Brookhuis, K.A.

    2013-01-01

    The study objective was to determine the influence of sample collection for two different collection methods on THC concentrations and to compare THC concentrations collected by both methods. A total of 136 pairs of oral fluid samples from subjects who had recently smoked Cannabis were obtained by

  6. On summary measure analysis of linear trend repeated measures data: performance comparison with two competing methods.

    Science.gov (United States)

    Vossoughi, Mehrdad; Ayatollahi, S M T; Towhidi, Mina; Ketabchi, Farzaneh

    2012-03-22

    The summary measure approach (SMA) is sometimes the only applicable tool for the analysis of repeated measurements in medical research, especially when the number of measurements is relatively large. This study aimed to describe techniques based on summary measures for the analysis of linear trend repeated measures data and then to compare performances of SMA, linear mixed model (LMM), and unstructured multivariate approach (UMA). Practical guidelines based on the least squares regression slope and mean of response over time for each subject were provided to test time, group, and interaction effects. Through Monte Carlo simulation studies, the efficacy of SMA vs. LMM and traditional UMA, under different types of covariance structures, was illustrated. All the methods were also employed to analyze two real data examples. Based on the simulation and example results, it was found that the SMA completely dominated the traditional UMA and performed convincingly close to the best-fitting LMM in testing all the effects. However, the LMM was not often robust and led to non-sensible results when the covariance structure for errors was misspecified. The results emphasized discarding the UMA which often yielded extremely conservative inferences as to such data. It was shown that summary measure is a simple, safe and powerful approach in which the loss of efficiency compared to the best-fitting LMM was generally negligible. The SMA is recommended as the first choice to reliably analyze the linear trend data with a moderate to large number of measurements and/or small to moderate sample sizes.

  7. Comparability and repeatability of three commonly used methods for measuring endurance capacity.

    Science.gov (United States)

    Baxter-Gilbert, James; Mühlenhaupt, Max; Whiting, Martin J

    2017-12-01

    Measures of endurance (time to exhaustion) have been used to address a wide range of questions in ecomorphological and physiological research, as well as being used as a proxy for survival and fitness. Swimming, stationary (circular) track running, and treadmill running are all commonly used methods for measuring endurance. Despite the use of these methods across a broad range of taxa, how comparable these methods are to one another, and whether they are biologically relevant, is rarely examined. We used Australian water dragons (Intellagama lesueurii), a species that is morphologically adept at climbing, swimming, and running, to compare these three methods of endurance and examined if there is repeatability within and between trial methods. We found that time to exhaustion was not highly repeatable within a method, suggesting that single measures or a mean time to exhaustion across trials are not appropriate. Furthermore, we compared mean maximal endurance times among the three methods, and found that the two running methods (i.e., stationary track and treadmill) were similar, but swimming was distinctly different, resulting in lower mean maximal endurance times. Finally, an individual's endurance rank was not repeatable across methods, suggesting that the three endurance trial methods are not providing similar information about an individual's performance capacity. Overall, these results highlight the need to carefully match a measure of performance capacity with the study species and the research questions being asked so that the methods being used are behaviorally, ecologically, and physiologically relevant. © 2018 Wiley Periodicals, Inc.

  8. Repeatability of visual acuity measurement.

    Science.gov (United States)

    Raasch, T W; Bailey, I L; Bullimore, M A

    1998-05-01

    This study investigates features of visual acuity chart design and acuity testing scoring methods which affect the validity and repeatability of visual acuity measurements. Visual acuity was measured using the Sloan and British Standard letter series, and Landolt rings. Identifiability of the different letters as a function of size was estimated, and expressed in the form of frequency-of-seeing curves. These functions were then used to simulate acuity measurements with a variety of chart designs and scoring criteria. Systematic relationships exist between chart design parameters and acuity score, and acuity score repeatability. In particular, an important feature of a chart, that largely determines the repeatability of visual acuity measurement, is the amount of size change attributed to each letter. The methods used to score visual acuity performance also affect repeatability. It is possible to evaluate acuity score validity and repeatability using the statistical principles discussed here.

  9. Analyzing Repeated Measures Marginal Models on Sample Surveys with Resampling Methods

    Directory of Open Access Journals (Sweden)

    James D. Knoke

    2005-12-01

    Full Text Available Packaged statistical software for analyzing categorical, repeated measures marginal models on sample survey data with binary covariates does not appear to be available. Consequently, this report describes a customized SAS program which accomplishes such an analysis on survey data with jackknifed replicate weights for which the primary sampling unit information has been suppressed for respondent confidentiality. First, the program employs the Macro Language and the Output Delivery System (ODS to estimate the means and covariances of indicator variables for the response variables, taking the design into account. Then, it uses PROC CATMOD and ODS, ignoring the survey design, to obtain the design matrix and hypothesis test specifications. Finally, it enters these results into another run of CATMOD, which performs automated direct input of the survey design specifications and accomplishes the appropriate analysis. This customized SAS program can be employed, with minor editing, to analyze general categorical, repeated measures marginal models on sample surveys with replicate weights. Finally, the results of our analysis accounting for the survey design are compared to the results of two alternate analyses of the same data. This comparison confirms that such alternate analyses, which do not properly account for the design, do not produce useful results.

  10. Analysis of repeated measures data

    CERN Document Server

    Islam, M Ataharul

    2017-01-01

    This book presents a broad range of statistical techniques to address emerging needs in the field of repeated measures. It also provides a comprehensive overview of extensions of generalized linear models for the bivariate exponential family of distributions, which represent a new development in analysing repeated measures data. The demand for statistical models for correlated outcomes has grown rapidly recently, mainly due to presence of two types of underlying associations: associations between outcomes, and associations between explanatory variables and outcomes. The book systematically addresses key problems arising in the modelling of repeated measures data, bearing in mind those factors that play a major role in estimating the underlying relationships between covariates and outcome variables for correlated outcome data. In addition, it presents new approaches to addressing current challenges in the field of repeated measures and models based on conditional and joint probabilities. Markov models of first...

  11. Evaluation, including effects of storage and repeated freezing and thawing, of a method for measurement of urinary creatinine

    DEFF Research Database (Denmark)

    Garde, A H; Hansen, Åse Marie; Kristiansen, J

    2003-01-01

    The aims of this study were to elucidate to what extent storage and repeated freezing and thawing influenced the concentration of creatinine in urine samples and to evaluate the method for determination of creatinine in urine. The creatinine method was based on the well-known Jaffe's reaction...... and measured on a COBAS Mira autoanalyser from Roche. The main findings were that samples for analysis of creatinine should be kept at a temperature of -20 degrees C or lower and frozen and thawed only once. The limit of detection, determined as 3 x SD of 20 determinations of a sample at a low concentration (6...

  12. Measuring the Dynamic Soil Response During Repeated Wheeling Using Seismic Methods

    DEFF Research Database (Denmark)

    Keller, Thomas; Carizzon, Marco; Berisso, Feto Esimo

    2013-01-01

    was performed with an agricultural tire (60 kN wheel load) on a gleyic Cambisol. We measured Vp using an acoustic (microseismic) device at various depths before, during (i.e., below the tire), and after wheeling. In addition, we measured bulk density and penetrometer resistance before and after wheeling...

  13. Performance of bias-correction methods for exposure measurement error using repeated measurements with and without missing data.

    Science.gov (United States)

    Batistatou, Evridiki; McNamee, Roseanne

    2012-12-10

    It is known that measurement error leads to bias in assessing exposure effects, which can however, be corrected if independent replicates are available. For expensive replicates, two-stage (2S) studies that produce data 'missing by design', may be preferred over a single-stage (1S) study, because in the second stage, measurement of replicates is restricted to a sample of first-stage subjects. Motivated by an occupational study on the acute effect of carbon black exposure on respiratory morbidity, we compare the performance of several bias-correction methods for both designs in a simulation study: an instrumental variable method (EVROS IV) based on grouping strategies, which had been recommended especially when measurement error is large, the regression calibration and the simulation extrapolation methods. For the 2S design, either the problem of 'missing' data was ignored or the 'missing' data were imputed using multiple imputations. Both in 1S and 2S designs, in the case of small or moderate measurement error, regression calibration was shown to be the preferred approach in terms of root mean square error. For 2S designs, regression calibration as implemented by Stata software is not recommended in contrast to our implementation of this method; the 'problematic' implementation of regression calibration although substantially improved with use of multiple imputations. The EVROS IV method, under a good/fairly good grouping, outperforms the regression calibration approach in both design scenarios when exposure mismeasurement is severe. Both in 1S and 2S designs with moderate or large measurement error, simulation extrapolation severely failed to correct for bias. Copyright © 2012 John Wiley & Sons, Ltd.

  14. On balanced minimal repeated measurements designs

    Directory of Open Access Journals (Sweden)

    Shakeel Ahmad Mir

    2014-10-01

    Full Text Available Repeated Measurements designs are concerned with scientific experiments in which each experimental unit is assigned more than once to a treatment either different or identical. This class of designs has the property that the unbiased estimators for elementary contrasts among direct and residual effects are obtainable. Afsarinejad (1983 provided a method of constructing balanced Minimal Repeated Measurements designs p < t , when t is an odd or prime power, one or more than one treatment may occur more than once in some sequences and  designs so constructed no longer remain uniform in periods. In this paper an attempt has been made to provide a new method to overcome this drawback. Specifically, two cases have been considered                RM[t,n=t(t-t/(p-1,p], λ2=1 for balanced minimal repeated measurements designs and  RM[t,n=2t(t-t/(p-1,p], λ2=2 for balanced  repeated measurements designs. In addition , a method has been provided for constructing              extra-balanced minimal designs for special case RM[t,n=t2/(p-1,p], λ2=1.

  15. Nonparametric additive regression for repeatedly measured data

    KAUST Repository

    Carroll, R. J.; Maity, A.; Mammen, E.; Yu, K.

    2009-01-01

    We develop an easily computed smooth backfitting algorithm for additive model fitting in repeated measures problems. Our methodology easily copes with various settings, such as when some covariates are the same over repeated response measurements

  16. Nonparametric additive regression for repeatedly measured data

    KAUST Repository

    Carroll, R. J.

    2009-05-20

    We develop an easily computed smooth backfitting algorithm for additive model fitting in repeated measures problems. Our methodology easily copes with various settings, such as when some covariates are the same over repeated response measurements. We allow for a working covariance matrix for the regression errors, showing that our method is most efficient when the correct covariance matrix is used. The component functions achieve the known asymptotic variance lower bound for the scalar argument case. Smooth backfitting also leads directly to design-independent biases in the local linear case. Simulations show our estimator has smaller variance than the usual kernel estimator. This is also illustrated by an example from nutritional epidemiology. © 2009 Biometrika Trust.

  17. Multivariate linear models and repeated measurements revisited

    DEFF Research Database (Denmark)

    Dalgaard, Peter

    2009-01-01

    Methods for generalized analysis of variance based on multivariate normal theory have been known for many years. In a repeated measurements context, it is most often of interest to consider transformed responses, typically within-subject contrasts or averages. Efficiency considerations leads...... to sphericity assumptions, use of F tests and the Greenhouse-Geisser and Huynh-Feldt adjustments to compensate for deviations from sphericity. During a recent implementation of such methods in the R language, the general structure of such transformations was reconsidered, leading to a flexible specification...

  18. Repeatability of Brain Volume Measurements Made with the Atlas-based Method from T1-weighted Images Acquired Using a 0.4 Tesla Low Field MR Scanner.

    Science.gov (United States)

    Goto, Masami; Suzuki, Makoto; Mizukami, Shinya; Abe, Osamu; Aoki, Shigeki; Miyati, Tosiaki; Fukuda, Michinari; Gomi, Tsutomu; Takeda, Tohoru

    2016-10-11

    An understanding of the repeatability of measured results is important for both the atlas-based and voxel-based morphometry (VBM) methods of magnetic resonance (MR) brain volumetry. However, many recent studies that have investigated the repeatability of brain volume measurements have been performed using static magnetic fields of 1-4 tesla, and no study has used a low-strength static magnetic field. The aim of this study was to investigate the repeatability of measured volumes using the atlas-based method and a low-strength static magnetic field (0.4 tesla). Ten healthy volunteers participated in this study. Using a 0.4 tesla magnetic resonance imaging (MRI) scanner and a quadrature head coil, three-dimensional T 1 -weighted images (3D-T 1 WIs) were obtained from each subject, twice on the same day. VBM8 software was used to construct segmented normalized images [gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) images]. The regions-of-interest (ROIs) of GM, WM, CSF, hippocampus (HC), orbital gyrus (OG), and cerebellum posterior lobe (CPL) were generated using WFU PickAtlas. The percentage change was defined as[100 × (measured volume with first segmented image - mean volume in each subject)/(mean volume in each subject)]The average percentage change was calculated as the percentage change in the 6 ROIs of the 10 subjects. The mean of the average percentage changes for each ROI was as follows: GM, 0.556%; WM, 0.324%; CSF, 0.573%; HC, 0.645%; OG, 1.74%; and CPL, 0.471%. The average percentage change was higher for the orbital gyrus than for the other ROIs. We consider that repeatability of the atlas-based method is similar between 0.4 and 1.5 tesla MR scanners. To our knowledge, this is the first report to show that the level of repeatability with a 0.4 tesla MR scanner is adequate for the estimation of brain volume change by the atlas-based method.

  19. Objectivity of two methods of differentiating fibre types and repeatability of measurements by application of the TEMA image analysis system.

    Science.gov (United States)

    Henckel, P; Ducro, B; Oksbjerg, N; Hassing, L

    1998-01-01

    The objectivity of two of the most widely used methods for differentiation of fibre types, i.e. 1) the myosin ATP-ase method (Brooke and Kaiser, 1970a,b) and 2) the combined method, by which the myosin ATP-ase reaction is used to differentiate between fast and slow twitch fibres and NADH-tetrazolium reductase activity is used to identify the subgroups of fast twitch fibres (Ashmore and Doerr, 1970, Peter et al., 1972), was assessed in muscle samples from horses, calves and pigs. We also assessed the objectivity of the alpha-amylase-PAS preparation for the visualisation of capillaries (Andersen, 1975) in these species. For the purpose of reducing the time costs of histochemical analysis of muscle samples, we have developed an interactive image analysis system which is described. All analyses are performed on this system. In accordance with several other investigations, differences between the two methods of differentiating fibre types were found only for the relative distribution of the fast-twitch fibre subgroups (p 87%), the impact of differences in pre-requisites (varied degrees of overlap between the fibre types) for performing the differentiation by the combined method raises a question of the reliability of this method. Apparently, no general rules for comparison of results of distribution of the two subgroups of fast twitch fibres by the two methods are applicable. The alpha-amylase-PAS method was found to be a fairly objective method to identify capillaries in muscles from horses, calves and pigs. However, as capillarity described in combination with other traits to give an indication of diffusion characteristics is significantly influenced by person, it is recommended that the same person perform all the analysis of a project. In addition to the methodological results in this study, we have shown that by application of the TEMA image analysis system, which is more rapid compared with the time-consuming traditional method for evaluation of histochemical

  20. Analysis of Longitudinal Studies With Repeated Outcome Measures: Adjusting for Time-Dependent Confounding Using Conventional Methods.

    Science.gov (United States)

    Keogh, Ruth H; Daniel, Rhian M; VanderWeele, Tyler J; Vansteelandt, Stijn

    2018-05-01

    Estimation of causal effects of time-varying exposures using longitudinal data is a common problem in epidemiology. When there are time-varying confounders, which may include past outcomes, affected by prior exposure, standard regression methods can lead to bias. Methods such as inverse probability weighted estimation of marginal structural models have been developed to address this problem. However, in this paper we show how standard regression methods can be used, even in the presence of time-dependent confounding, to estimate the total effect of an exposure on a subsequent outcome by controlling appropriately for prior exposures, outcomes, and time-varying covariates. We refer to the resulting estimation approach as sequential conditional mean models (SCMMs), which can be fitted using generalized estimating equations. We outline this approach and describe how including propensity score adjustment is advantageous. We compare the causal effects being estimated using SCMMs and marginal structural models, and we compare the two approaches using simulations. SCMMs enable more precise inferences, with greater robustness against model misspecification via propensity score adjustment, and easily accommodate continuous exposures and interactions. A new test for direct effects of past exposures on a subsequent outcome is described.

  1. Intra-examiner repeatability and agreement in accommodative response measurements.

    Science.gov (United States)

    Antona, B; Sanchez, I; Barrio, A; Barra, F; Gonzalez, E

    2009-11-01

    Clinical measurement of the accommodative response (AR) identifies the focusing plane of a subject with respect to the accommodative target. To establish whether a significant change in AR has occurred, it is important to determine the repeatability of this measurement. This study had two aims: First, to determine the intraexaminer repeatability of AR measurements using four clinical methods: Nott retinoscopy, monocular estimate method (MEM) retinoscopy, binocular crossed cylinder test (BCC) and near autorefractometry. Second, to study the level of agreement between AR measurements obtained with the different methods. The AR of the right eye at one accommodative demand of 2.50 D (40 cm) was measured on two separate occasions in 61 visually normal subjects of mean age 19.7 years (range 18-32 years). The intraexaminer repeatability of the tests, and agreement between them, were estimated by the Bland-Altman method. We determined mean differences (MD) and the 95% limits of agreement [coefficient of repeatability (COR) and coefficient of agreement (COA)]. Nott retinoscopy and BCC offered the best repeatability, showing the lowest MD and narrowest 95% interval of agreement (Nott: -0.10 +/- 0.66 D, BCC: -0.05 +/- 0.75 D). The 95% limits of agreement for the four techniques were similar (COA = +/- 0.92 to +/-1.00 D) yet clinically significant, according to the expected values of the AR. The two dynamic retinoscopy techniques (Nott and MEM) had a better agreement (COA = +/-0.64 D) although this COA must be interpreted in the context of the low MEM repeatability (COR = +/-0.98 D). The best method of assessing AR was Nott retinoscopy. The BCC technique was also repeatable, and both are recommended as suitable methods for clinical use. Despite better agreement between MEM and Nott, agreement among the remaining methods was poor such that their interchangeable use in clinical practice is not recommended.

  2. Does Dry Eye Affect Repeatability of Corneal Topography Measurements?

    Directory of Open Access Journals (Sweden)

    Aysun Şanal Doğan

    2018-04-01

    Full Text Available Objectives: The purpose of this study was to assess the repeatability of corneal topography measurements in dry eye patients and healthy controls. Materials and Methods: Participants underwent consecutive corneal topography measurements (Sirius; Costruzione Strumenti Oftalmici, Florence, Italy. Two images with acquisition quality higher than 90% were accepted. The following parameters were evaluated: minimum and central corneal thickness, aqueous depth, apex curvature, anterior chamber volume, horizontal anterior chamber diameter, iridocorneal angle, cornea volume, and average simulated keratometry. Repeatability was assessed by calculating intra-class correlation coefficient. Results: Thirty-three patients with dry eye syndrome and 40 healthy controls were enrolled to the study. The groups were similar in terms of age (39 [18-65] vs. 30.5 [18-65] years, p=0.198 and gender (M/F: 4/29 vs. 8/32, p=0.366. Intra-class correlation coefficients among all topography parameters within both groups showed excellent repeatability (>0.90. Conclusion: The anterior segment measurements provided by the Sirius corneal topography system were highly repeatable for dry eye patients and are sufficiently reliable for clinical practice and research.

  3. [Analysis of variance of repeated data measured by water maze with SPSS].

    Science.gov (United States)

    Qiu, Hong; Jin, Guo-qin; Jin, Ru-feng; Zhao, Wei-kang

    2007-01-01

    To introduce the method of analyzing repeated data measured by water maze with SPSS 11.0, and offer a reference statistical method to clinical and basic medicine researchers who take the design of repeated measures. Using repeated measures and multivariate analysis of variance (ANOVA) process of the general linear model in SPSS and giving comparison among different groups and different measure time pairwise. Firstly, Mauchly's test of sphericity should be used to judge whether there were relations among the repeatedly measured data. If any (PSPSS statistical package is available to fulfil this process.

  4. The effect of repeated applanation on subsequent IOP measurements.

    Science.gov (United States)

    AlMubrad, Turki M; Ogbuehi, Kelechi C

    2008-11-01

    In studies aimed at assessing the accuracy and repeatability of non-contact tonometers, the order in which these tonometers and the Goldmann tonometer are used is usually randomised despite studies in the literature that demonstrate an ocular massage effect that occurs post-applanation but not after non-contact tonometry. The purpose of this study was to investigate the effect of repeated corneal applanation on subsequent assessments of IOP. Data were obtained from 65 left eyes of 65 young, oculovisual normals. Three sets of IOP measurements were obtained, one set with the Goldmann applanation tonometer and two with the Topcon CT80 non-contact tonometer (one set each before and after applanation with the Goldmann tonometer), in each one of two separate measurement sessions, one week apart. The average (and SD) IOP measured with the Goldmann tonometer in the first session (14.8+/-2.9 mmHg) did not vary significantly from the IOP measured with the non-contact tonometer (pre-applanation) in both sessions or with the average Goldmann IOP in the second session. The bias (mean difference +/- SD) between methods was 0.3+/-1.4 mmHg and 0.4+/-1.4 mmHg, respectively, for the first and second sessions, with the CT80 (pre-applanation) recording the higher IOP in both sessions. The within-session repeatability coefficients were +/-2.3 mmHg, +/-2.6 mmHg, +/-2.1 mmHg and +/-2.0 mmHg for the CT80 (pre-applanation) in the first and second sessions, and the Goldmann tonometer in the first and second sessions, respectively. Test-retest repeatability coefficients were +/-2.8 mmHg and +/-2.5 mmHg for the CT80 (pre-applanation) and the Goldmann tonometer respectively. Post-applanation with the Goldmann tonometer, there was a statistically significant (pcontact tonometer in both sessions. These results suggest that repeated corneal applanation leads to a statistically significant reduction in IOP on subsequent measurements.

  5. Unstable systems and repeated measurements. II

    International Nuclear Information System (INIS)

    Exner, P.

    1977-01-01

    Two examples are treated. In the first, the chamber structure is only assumed to be periodic and P(t) is an exponential. In the second example no specific assumption is made about the primary decay law and the measuring device is structured as an idealized spark chamber. This example contains the results by Beskow and Nilsson as a special case. (author)

  6. Stability of parameters in repeated TVA measures

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik

    Several recent studies have explored the limitations of human visual short-term memory or VSTM (e.g. Luck & Vogel, 1997; Wheeler & Treisman, 2002; Alvarez & Cavanagh, 2004). Usually researchers agree that VSTM is limited to a capacity of about 3 to 4 objects at any given moment (Cowan, 2001......). Capacity of short-term memory is measured in a range of studies often using the change detection paradigm (CD). However, the whole report paradigm (WR) may be a more reliable paradigm (Cusack, Lehmann, Veldsman, & Mitchell, 2009). Moreover, each individual WR trial yield more information compared to a CD...

  7. Intelligence Is in the Eye of the Beholder: Investigating Repeated IQ Measurements in Forensic Psychiatry

    Science.gov (United States)

    Habets, Petra; Jeandarme, Inge; Uzieblo, Kasia; Oei, Karel; Bogaerts, Stefan

    2015-01-01

    Background: A stable assessment of cognition is of paramount importance for forensic psychiatric patients (FPP). The purpose of this study was to compare repeated measures of IQ scores in FPPs with and without intellectual disability. Methods: Repeated measurements of IQ scores in FPPs (n = 176) were collected. Differences between tests were…

  8. On model selections for repeated measurement data in clinical studies.

    Science.gov (United States)

    Zou, Baiming; Jin, Bo; Koch, Gary G; Zhou, Haibo; Borst, Stephen E; Menon, Sandeep; Shuster, Jonathan J

    2015-05-10

    Repeated measurement designs have been widely used in various randomized controlled trials for evaluating long-term intervention efficacies. For some clinical trials, the primary research question is how to compare two treatments at a fixed time, using a t-test. Although simple, robust, and convenient, this type of analysis fails to utilize a large amount of collected information. Alternatively, the mixed-effects model is commonly used for repeated measurement data. It models all available data jointly and allows explicit assessment of the overall treatment effects across the entire time spectrum. In this paper, we propose an analytic strategy for longitudinal clinical trial data where the mixed-effects model is coupled with a model selection scheme. The proposed test statistics not only make full use of all available data but also utilize the information from the optimal model deemed for the data. The performance of the proposed method under various setups, including different data missing mechanisms, is evaluated via extensive Monte Carlo simulations. Our numerical results demonstrate that the proposed analytic procedure is more powerful than the t-test when the primary interest is to test for the treatment effect at the last time point. Simulations also reveal that the proposed method outperforms the usual mixed-effects model for testing the overall treatment effects across time. In addition, the proposed framework is more robust and flexible in dealing with missing data compared with several competing methods. The utility of the proposed method is demonstrated by analyzing a clinical trial on the cognitive effect of testosterone in geriatric men with low baseline testosterone levels. Copyright © 2015 John Wiley & Sons, Ltd.

  9. Repeated swim stress alters brain benzodiazepine receptors measured in vivo

    International Nuclear Information System (INIS)

    Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.

    1989-01-01

    The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of [ 3 H]Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in [14C]iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress [an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures], although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results

  10. Repeated swim stress alters brain benzodiazepine receptors measured in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.

    1989-06-01

    The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of (/sup 3/H)Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in (14C)iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress (an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures), although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results.

  11. Repeatability of Objective Measurements of Linear Udder and Body ...

    African Journals Online (AJOL)

    The objective of this study was to estimates the repeatability of objective measurements on linear udder and body conformation traits and to evaluate the objectivity of the measurements in Friesian x Bunaji cows. Data from 50 (F1) Frisian X Bunaji cows collected between 2007 and 2008 at the Dairy Research Farm of the ...

  12. Conservative Sample Size Determination for Repeated Measures Analysis of Covariance.

    Science.gov (United States)

    Morgan, Timothy M; Case, L Douglas

    2013-07-05

    In the design of a randomized clinical trial with one pre and multiple post randomized assessments of the outcome variable, one needs to account for the repeated measures in determining the appropriate sample size. Unfortunately, one seldom has a good estimate of the variance of the outcome measure, let alone the correlations among the measurements over time. We show how sample sizes can be calculated by making conservative assumptions regarding the correlations for a variety of covariance structures. The most conservative choice for the correlation depends on the covariance structure and the number of repeated measures. In the absence of good estimates of the correlations, the sample size is often based on a two-sample t-test, making the 'ultra' conservative and unrealistic assumption that there are zero correlations between the baseline and follow-up measures while at the same time assuming there are perfect correlations between the follow-up measures. Compared to the case of taking a single measurement, substantial savings in sample size can be realized by accounting for the repeated measures, even with very conservative assumptions regarding the parameters of the assumed correlation matrix. Assuming compound symmetry, the sample size from the two-sample t-test calculation can be reduced at least 44%, 56%, and 61% for repeated measures analysis of covariance by taking 2, 3, and 4 follow-up measures, respectively. The results offer a rational basis for determining a fairly conservative, yet efficient, sample size for clinical trials with repeated measures and a baseline value.

  13. High precision measurement of the micro-imaging system to check repeatability of precision

    International Nuclear Information System (INIS)

    Cheng Lin; Song Li; Ma Chuntao; Luo Hongxin; Wang Jie

    2010-01-01

    The beamlines slits of Shanghai Synchrotron Radiation Facility (SSRF) are required to have a repeatability of better than 1 μm. Before the slits installation, the off-line and/or on-line repeatability measurements must be conducted. A machine vision measuring system based on high resolution CCD and adjustable high magnification lens was used in this regard. A multi-level filtering method was used to treat the imaging data. After image binarization, the imaging noises were depressed effectively by using of algebraic mean filtering, statistics median filtering,and the least square filtering. Using the subtracted image between the images before and after slit movement, an average displacement of slit blades could be obtained, and the repeatability of slit could be measured, with a resolution of 0.3 μm of the measurement system. The experimental results show that this measurement system meets the requirements for non-contact measurements to the repeatability of slits. (authors)

  14. Does Dry Eye Affect Repeatability of Corneal Topography Measurements?

    Science.gov (United States)

    Doğan, Aysun Şanal; Gürdal, Canan; Köylü, Mehmet Talay

    2018-04-01

    The purpose of this study was to assess the repeatability of corneal topography measurements in dry eye patients and healthy controls. Participants underwent consecutive corneal topography measurements (Sirius; Costruzione Strumenti Oftalmici, Florence, Italy). Two images with acquisition quality higher than 90% were accepted. The following parameters were evaluated: minimum and central corneal thickness, aqueous depth, apex curvature, anterior chamber volume, horizontal anterior chamber diameter, iridocorneal angle, cornea volume, and average simulated keratometry. Repeatability was assessed by calculating intra-class correlation coefficient. Thirty-three patients with dry eye syndrome and 40 healthy controls were enrolled to the study. The groups were similar in terms of age (39 [18-65] vs. 30.5 [18-65] years, p=0.198) and gender (M/F: 4/29 vs. 8/32, p=0.366). Intra-class correlation coefficients among all topography parameters within both groups showed excellent repeatability (>0.90). The anterior segment measurements provided by the Sirius corneal topography system were highly repeatable for dry eye patients and are sufficiently reliable for clinical practice and research.

  15. Insertion device and method for accurate and repeatable target insertion

    Science.gov (United States)

    Gubeli, III, Joseph F.; Shinn, Michelle D.; Bevins, Michael E.; Dillon-Townes, Lawrence; Neil, George R.

    2017-07-04

    The present invention discloses a device and a method for inserting and positioning a target within a free electron laser, particle accelerator, or other such device that generates or utilizes a beam of energy or particles. The system includes a three-point registration mechanism that insures angular and translational accuracy and repeatability of positioning upon multiple insertions within the same structure.

  16. Measuring Repeatability of the Focus-variable Lenses

    Directory of Open Access Journals (Sweden)

    Jan Řezníček

    2014-12-01

    Full Text Available In the field of photogrammetry, the optical system, usually represented by the glass lens, is used for metric purposes. Therefore, the aberration characteristics of such a lens, inducing deviations from projective imaging, has to be well known. However, the most important property of the metric lens is the stability of its glass and mechanical elements, ensuring long-term reliability of the measured parameters. In case of a focus-variable lens, the repeatability of the lens setup is important as well. Lenses with a fixed focal length are usually considered as “fixed” though, in fact, most of them contain one or more movable glass elements, providing the focusing function. In cases where the lens is not equipped with fixing screws, the repeatability of the calibration parameters should be known. This paper derives simple mathematical formulas that can be used for measuring the repeatability of the focus-variable lenses, and gives a demonstrative example of such measuring. The given procedure has the advantage that only demanded parameters are estimated, hence, no unwanted correlations with the additional parameters exist. The test arrangement enables us to measure each demanded magnification of the optical system, which is important in close-range photogrammetry.

  17. Evaluation of the Repeatability and the Reproducibility of AL-Scan Measurements Obtained by Residents

    Directory of Open Access Journals (Sweden)

    Mehmet Kola

    2014-01-01

    Full Text Available Purpose. To assess the repeatability and reproducibility of ocular biometry and intraocular lens (IOL power measurements obtained by ophthalmology residents using an AL-Scan device, a novel optical biometer. Methods. Two ophthalmology residents were instructed regarding the AL-Scan device. Both performed ocular biometry and IOL power measurements using AL-Scan, three times on each of 128 eyes, independently of one another. Corneal keratometry readings, horizontal iris width, central corneal thickness, anterior chamber depth, pupil size, and axial length values measured by both residents were recorded together with IOL power values calculated on the basis of four different IOL calculation formulas (SRK/T, Holladay, and HofferQ. Repeatability and reproducibility of the measurements obtained were analyzed using the intraclass correlation coefficient (ICC. Results. Repeatability (ICC, 0.872-0.999 for resident 1 versus 0.905-0.999 for resident 2 and reproducibility (ICC, 0.916-0.999 were high for all biometric measurements. Repeatability (ICC, 0.981-0.983 for resident 1 versus 0.995-0.996 for resident 2 and reproducibility were also high for all IOL power measurements (ICC, 0.996 for all. Conclusions. The AL-Scan device exhibits good repeatability and reproducibility in all biometric measurements and IOL power calculations, independent of the operator concerned.

  18. Analysis of repeated measurement data in the clinical trials

    Science.gov (United States)

    Singh, Vineeta; Rana, Rakesh Kumar; Singhal, Richa

    2013-01-01

    Statistics is an integral part of Clinical Trials. Elements of statistics span Clinical Trial design, data monitoring, analyses and reporting. A solid understanding of statistical concepts by clinicians improves the comprehension and the resulting quality of Clinical Trials. In biomedical research it has been seen that researcher frequently use t-test and ANOVA to compare means between the groups of interest irrespective of the nature of the data. In Clinical Trials we record the data on the patients more than two times. In such a situation using the standard ANOVA procedures is not appropriate as it does not consider dependencies between observations within subjects in the analysis. To deal with such types of study data Repeated Measure ANOVA should be used. In this article the application of One-way Repeated Measure ANOVA has been demonstrated by using the software SPSS (Statistical Package for Social Sciences) Version 15.0 on the data collected at four time points 0 day, 15th day, 30th day, and 45th day of multicentre clinical trial conducted on Pandu Roga (~Iron Deficiency Anemia) with an Ayurvedic formulation Dhatrilauha. PMID:23930038

  19. Unitarity, Feedback, Interactions - Dynamics Emergent from Repeated Measurements

    Science.gov (United States)

    Corona Ugalde, Paulina; Altamirano, Natacha; Mann, Robert; Zych, Magdalena

    Modern measurement theory dispenses with the description of a measurement as a projection. Rather, the measurement is understood as an operation, whereby the system's final state is determined by an action of a completely positive trace non-increasing map and the outcomes are described by linear operators on the system, distributed according to a positive-operator valued measure (POVM). The POVM approach unifies the theory of measurements with a general description of dynamics, the theory of open quantum systems. Engineering a particular measurement and engineering a particular dynamics for the system are thus two complementary aspects of the same conceptual framework. This correspondence is directly applied in quantum simulations and quantum control theory . With this motivation, we study what types of dynamics can emerge from a model of repeated short interactions of a system with a set of ancillae. We show that contingent on the model parameters the resulting dynamics ranges from exact unitarity to arbitrary fast decoherence. For a series of measurements the effective dynamics includes feedback-control, which for a composite system yields effective interactions between the subsystems. We quantify the amount of decoherence accompanying such induced interactions. The simple framework used in the present study can find applications in devising novel quantum control protocols, or quantum simulations.

  20. Dispersion Measure Variation of Repeating Fast Radio Burst Sources

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yuan-Pei; Zhang, Bing, E-mail: yypspore@gmail.com, E-mail: zhang@physics.unlv.edu [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

    2017-09-20

    The repeating fast radio burst (FRB) 121102 was recently localized in a dwarf galaxy at a cosmological distance. The dispersion measure (DM) derived for each burst from FRB 121102 so far has not shown significant evolution, even though an apparent increase was recently seen with newly detected VLA bursts. It is expected that more repeating FRB sources may be detected in the future. In this work, we investigate a list of possible astrophysical processes that might cause DM variation of a particular FRB source. The processes include (1) cosmological scale effects such as Hubble expansion and large-scale structure fluctuations; (2) FRB local effects such as gas density fluctuation, expansion of a supernova remnant (SNR), a pulsar wind nebula, and an H ii region; and (3) the propagation effect due to plasma lensing. We find that the DM variations contributed by the large-scale structure are extremely small, and any observable DM variation is likely caused by the plasma local to the FRB source. In addition to mechanisms that decrease DM over time, we suggest that an FRB source in an expanding SNR around a nearly neutral ambient medium during the deceleration (Sedov–Taylor and snowplow) phases or in a growing H ii region can increase DM. Some effects (e.g., an FRB source moving in an H ii region or plasma lensing) can produce either positive or negative DM variations. Future observations of DM variations of FRB 121102 and other repeating FRB sources can provide important clues regarding the physical origin of these sources.

  1. Dispersion Measure Variation of Repeating Fast Radio Burst Sources

    International Nuclear Information System (INIS)

    Yang, Yuan-Pei; Zhang, Bing

    2017-01-01

    The repeating fast radio burst (FRB) 121102 was recently localized in a dwarf galaxy at a cosmological distance. The dispersion measure (DM) derived for each burst from FRB 121102 so far has not shown significant evolution, even though an apparent increase was recently seen with newly detected VLA bursts. It is expected that more repeating FRB sources may be detected in the future. In this work, we investigate a list of possible astrophysical processes that might cause DM variation of a particular FRB source. The processes include (1) cosmological scale effects such as Hubble expansion and large-scale structure fluctuations; (2) FRB local effects such as gas density fluctuation, expansion of a supernova remnant (SNR), a pulsar wind nebula, and an H ii region; and (3) the propagation effect due to plasma lensing. We find that the DM variations contributed by the large-scale structure are extremely small, and any observable DM variation is likely caused by the plasma local to the FRB source. In addition to mechanisms that decrease DM over time, we suggest that an FRB source in an expanding SNR around a nearly neutral ambient medium during the deceleration (Sedov–Taylor and snowplow) phases or in a growing H ii region can increase DM. Some effects (e.g., an FRB source moving in an H ii region or plasma lensing) can produce either positive or negative DM variations. Future observations of DM variations of FRB 121102 and other repeating FRB sources can provide important clues regarding the physical origin of these sources.

  2. Formatting data files for repeated-measures analyses in SPSS: Using the Aggregate and Restructure procedures

    Directory of Open Access Journals (Sweden)

    Gyslain Giguère

    2006-03-01

    Full Text Available In this tutorial, we demonstrate how to use the Aggregate and Restructure procedures available in SPSS (versions 11 and up to prepare data files for repeated-measures analyses. In the first two sections of the tutorial, we briefly describe the Aggregate and Restructure procedures. In the final section, we present an example in which the data from a fictional lexical decision task are prepared for analysis using a mixed-design ANOVA. The tutorial demonstrates that the presented method is the most efficient way to prepare data for repeated-measures analyses in SPSS.

  3. Power analysis for multivariate and repeated measures designs: a flexible approach using the SPSS MANOVA procedure.

    Science.gov (United States)

    D'Amico, E J; Neilands, T B; Zambarano, R

    2001-11-01

    Although power analysis is an important component in the planning and implementation of research designs, it is often ignored. Computer programs for performing power analysis are available, but most have limitations, particularly for complex multivariate designs. An SPSS procedure is presented that can be used for calculating power for univariate, multivariate, and repeated measures models with and without time-varying and time-constant covariates. Three examples provide a framework for calculating power via this method: an ANCOVA, a MANOVA, and a repeated measures ANOVA with two or more groups. The benefits and limitations of this procedure are discussed.

  4. Validity and repeatability of inertial measurement units for measuring gait parameters.

    Science.gov (United States)

    Washabaugh, Edward P; Kalyanaraman, Tarun; Adamczyk, Peter G; Claflin, Edward S; Krishnan, Chandramouli

    2017-06-01

    Inertial measurement units (IMUs) are small wearable sensors that have tremendous potential to be applied to clinical gait analysis. They allow objective evaluation of gait and movement disorders outside the clinic and research laboratory, and permit evaluation on large numbers of steps. However, repeatability and validity data of these systems are sparse for gait metrics. The purpose of this study was to determine the validity and between-day repeatability of spatiotemporal metrics (gait speed, stance percent, swing percent, gait cycle time, stride length, cadence, and step duration) as measured with the APDM Opal IMUs and Mobility Lab system. We collected data on 39 healthy subjects. Subjects were tested over two days while walking on a standard treadmill, split-belt treadmill, or overground, with IMUs placed in two locations: both feet and both ankles. The spatiotemporal measurements taken with the IMU system were validated against data from an instrumented treadmill, or using standard clinical procedures. Repeatability and minimally detectable change (MDC) of the system was calculated between days. IMUs displayed high to moderate validity when measuring most of the gait metrics tested. Additionally, these measurements appear to be repeatable when used on the treadmill and overground. The foot configuration of the IMUs appeared to better measure gait parameters; however, both the foot and ankle configurations demonstrated good repeatability. In conclusion, the IMU system in this study appears to be both accurate and repeatable for measuring spatiotemporal gait parameters in healthy young adults. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Accuracy and repeatability of anthropometric facial measurements using cone beam computed tomography

    NARCIS (Netherlands)

    Fourie, Zacharias; Damstra, Janalt; Gerrits, Peter O.; Ren, Yijin

    Objective: The purpose of this study was to determine the accuracy and repeatability of linear anthropometric measurements on the soft tissue surface model generated from cone beam computed tomography scans. Materials and Methods: The study sample consisted of seven cadaver heads. The accuracy and

  6. [Analysis of binary classification repeated measurement data with GEE and GLMMs using SPSS software].

    Science.gov (United States)

    An, Shengli; Zhang, Yanhong; Chen, Zheng

    2012-12-01

    To analyze binary classification repeated measurement data with generalized estimating equations (GEE) and generalized linear mixed models (GLMMs) using SPSS19.0. GEE and GLMMs models were tested using binary classification repeated measurement data sample using SPSS19.0. Compared with SAS, SPSS19.0 allowed convenient analysis of categorical repeated measurement data using GEE and GLMMs.

  7. Repeatability of central corneal thickness measurement with the Pentacam HR system

    Directory of Open Access Journals (Sweden)

    Ruiz Simonato Alonso

    2012-02-01

    Full Text Available PURPOSE: To assess the repeatability of central corneal thickness measurement at the geometrical center (Central Corneal Thickness - CCT given by the Pentacam High Resolution (HR Comprehensive Eye Scanner (Oculus, Wetzlar, Germany over time. METHODS: Prospective, single center, observational study. Two separate CCT measurements were taken by the Pentacam corneal tomography exam (CTm 3 to 12 months apart, and compared. RESULTS: One hundred and sixteen eyes (n=116 of 62 health patients were included in this study. Average CCT in first and last visits was 541.6±37 µm and 543.6±36.9 µm respectively. Mean difference between both measurements was 9.2±6.4 µm, and there was no statistically significant difference in CCT measurement between visits, with good correlation between them (P = 0.057, r² = 0,9209. CONCLUSION: Pentacam (HR CTm gives repeatable CCT measurements over time.

  8. Spatial cluster detection for repeatedly measured outcomes while accounting for residential history.

    Science.gov (United States)

    Cook, Andrea J; Gold, Diane R; Li, Yi

    2009-10-01

    Spatial cluster detection has become an important methodology in quantifying the effect of hazardous exposures. Previous methods have focused on cross-sectional outcomes that are binary or continuous. There are virtually no spatial cluster detection methods proposed for longitudinal outcomes. This paper proposes a new spatial cluster detection method for repeated outcomes using cumulative geographic residuals. A major advantage of this method is its ability to readily incorporate information on study participants relocation, which most cluster detection statistics cannot. Application of these methods will be illustrated by the Home Allergens and Asthma prospective cohort study analyzing the relationship between environmental exposures and repeated measured outcome, occurrence of wheeze in the last 6 months, while taking into account mobile locations.

  9. Repeatability of junctional zone measurements using three-dimensional transvaginal ultrasound in healthy, fertile women

    DEFF Research Database (Denmark)

    Rasmussen, Christina Kjærgaard; Glavind, Julie; Madsen, Lene Duch

    2016-01-01

    -observer repeatability was evaluated according to the Bland-Altman method and expressed as coefficient of repeatability (CoR). Results: Using 3D-TVS we visualised a thin and regular JZ in most women. The posterior uterine wall had the largest median (interquartile range; iqr) value of JZmax (5.2 (iqr 3.8-6.5)mm. Ten out....... Correlations between measurements were poor in the narrow range of JZ thickness. Conclusions: The JZ has an indistinct outline by 3D-TVS resulting in an error of JZ measurement within a broad range of ±2-4 mm, but reduced by average measurements. The thickness of JZ varied within a narrow range of this healthy......, fertile population and reliability measurements of JZ thickness has to be evaluated in women with a wider range of JZ thickness....

  10. Repeatability in Color Measurements of a Spectrophotometer using Different Positioning Devices.

    Science.gov (United States)

    Hemming, Michael; Kwon, So Ran; Qian, Fang

    2015-12-01

    This study aimed to evaluate the repeatability of color measurements of an intraoral spectrophotometer with the use of three different methods by two operators. A total of 60 teeth were obtained, comprising 30 human maxillary teeth [central incisors (n = 10); canines (n = 10); molars (n = 10)] and 30 artificial teeth [lateral incisors (n = 10); premolar (n = 20)]. Multiple repeated color measurements were obtained from each tooth using three measuring methods by each of the two operators. Five typodonts with alternating artificial and human teeth were made. Measurements were taken by two operators with the Vita EasyShade spectrophotometer using the custom tray (CT), custom jig (CJ) and free hand (FH) method, twice, at an interval of 2 to 7 days. Friedman test was used to detect difference among the three color measuring methods. Post hoc Wilcoxon signed-rank test with Bonferroni correction applied was used for pair-wise comparison of color measurements among the three methods. Additionally, a paired-sample t-test was used to assess a significant difference between the two duplicated measurements made on the same tooth by the same operator for each color parameter and measuring method. For operator A, mean (SD) overall color change-ΔE* (SD) perceived for FH, CT and CJ were 2.21(2.00), 2.39 (1.58) and 2.86 (1.92), respectively. There was statistically significant difference in perceived ΔE* in FH vs CJ (p = 0.0107). However, there were no significant differences between FH and CT (p = 0.2829) or between CT and CJ (p = 0.1159). For operator B mean ΔE* (SD) for FH, CT and CJ were 3.24 (3.46), 1.95 (1.19) and 2.45 (1.56), respectively. There was a significant difference between FH and CT (p = 0.0031). However, there were no statistically significant differences in ΔE* in FH vs CJ (p = 0.3696) or CT vs CJ (p = 0.0809). The repeatability of color measurements was different among the three measuring methods by operators. Overall, the CT method worked well for both

  11. High-Dimensional Multivariate Repeated Measures Analysis with Unequal Covariance Matrices

    Science.gov (United States)

    Harrar, Solomon W.; Kong, Xiaoli

    2015-01-01

    In this paper, test statistics for repeated measures design are introduced when the dimension is large. By large dimension is meant the number of repeated measures and the total sample size grow together but either one could be larger than the other. Asymptotic distribution of the statistics are derived for the equal as well as unequal covariance cases in the balanced as well as unbalanced cases. The asymptotic framework considered requires proportional growth of the sample sizes and the dimension of the repeated measures in the unequal covariance case. In the equal covariance case, one can grow at much faster rate than the other. The derivations of the asymptotic distributions mimic that of Central Limit Theorem with some important peculiarities addressed with sufficient rigor. Consistent and unbiased estimators of the asymptotic variances, which make efficient use of all the observations, are also derived. Simulation study provides favorable evidence for the accuracy of the asymptotic approximation under the null hypothesis. Power simulations have shown that the new methods have comparable power with a popular method known to work well in low-dimensional situation but the new methods have shown enormous advantage when the dimension is large. Data from Electroencephalograph (EEG) experiment is analyzed to illustrate the application of the results. PMID:26778861

  12. A Network-Based Algorithm for Clustering Multivariate Repeated Measures Data

    Science.gov (United States)

    Koslovsky, Matthew; Arellano, John; Schaefer, Caroline; Feiveson, Alan; Young, Millennia; Lee, Stuart

    2017-01-01

    The National Aeronautics and Space Administration (NASA) Astronaut Corps is a unique occupational cohort for which vast amounts of measures data have been collected repeatedly in research or operational studies pre-, in-, and post-flight, as well as during multiple clinical care visits. In exploratory analyses aimed at generating hypotheses regarding physiological changes associated with spaceflight exposure, such as impaired vision, it is of interest to identify anomalies and trends across these expansive datasets. Multivariate clustering algorithms for repeated measures data may help parse the data to identify homogeneous groups of astronauts that have higher risks for a particular physiological change. However, available clustering methods may not be able to accommodate the complex data structures found in NASA data, since the methods often rely on strict model assumptions, require equally-spaced and balanced assessment times, cannot accommodate missing data or differing time scales across variables, and cannot process continuous and discrete data simultaneously. To fill this gap, we propose a network-based, multivariate clustering algorithm for repeated measures data that can be tailored to fit various research settings. Using simulated data, we demonstrate how our method can be used to identify patterns in complex data structures found in practice.

  13. Joint modelling of repeated measurement and time-to-event data: an introductory tutorial.

    Science.gov (United States)

    Asar, Özgür; Ritchie, James; Kalra, Philip A; Diggle, Peter J

    2015-02-01

    The term 'joint modelling' is used in the statistical literature to refer to methods for simultaneously analysing longitudinal measurement outcomes, also called repeated measurement data, and time-to-event outcomes, also called survival data. A typical example from nephrology is a study in which the data from each participant consist of repeated estimated glomerular filtration rate (eGFR) measurements and time to initiation of renal replacement therapy (RRT). Joint models typically combine linear mixed effects models for repeated measurements and Cox models for censored survival outcomes. Our aim in this paper is to present an introductory tutorial on joint modelling methods, with a case study in nephrology. We describe the development of the joint modelling framework and compare the results with those obtained by the more widely used approaches of conducting separate analyses of the repeated measurements and survival times based on a linear mixed effects model and a Cox model, respectively. Our case study concerns a data set from the Chronic Renal Insufficiency Standards Implementation Study (CRISIS). We also provide details of our open-source software implementation to allow others to replicate and/or modify our analysis. The results for the conventional linear mixed effects model and the longitudinal component of the joint models were found to be similar. However, there were considerable differences between the results for the Cox model with time-varying covariate and the time-to-event component of the joint model. For example, the relationship between kidney function as measured by eGFR and the hazard for initiation of RRT was significantly underestimated by the Cox model that treats eGFR as a time-varying covariate, because the Cox model does not take measurement error in eGFR into account. Joint models should be preferred for simultaneous analyses of repeated measurement and survival data, especially when the former is measured with error and the association

  14. Optimally Repeatable Kinetic Model Variant for Myocardial Blood Flow Measurements with 82Rb PET

    Directory of Open Access Journals (Sweden)

    Adrian F. Ocneanu

    2017-01-01

    Full Text Available Purpose. Myocardial blood flow (MBF quantification with Rb82 positron emission tomography (PET is gaining clinical adoption, but improvements in precision are desired. This study aims to identify analysis variants producing the most repeatable MBF measures. Methods. 12 volunteers underwent same-day test-retest rest and dipyridamole stress imaging with dynamic Rb82 PET, from which MBF was quantified using 1-tissue-compartment kinetic model variants: (1 blood-pool versus uptake region sampled input function (Blood/Uptake-ROI, (2 dual spillover correction (SOC-On/Off, (3 right blood correction (RBC-On/Off, (4 arterial blood transit delay (Delay-On/Off, and (5 distribution volume (DV constraint (Global/Regional-DV. Repeatability of MBF, stress/rest myocardial flow reserve (MFR, and stress/rest MBF difference (ΔMBF was assessed using nonparametric reproducibility coefficients (RPCnp = 1.45 × interquartile range. Results. MBF using SOC-On, RVBC-Off, Blood-ROI, Global-DV, and Delay-Off was most repeatable for combined rest and stress: RPCnp = 0.21 mL/min/g (15.8%. Corresponding MFR and ΔMBF RPCnp were 0.42 (20.2% and 0.24 mL/min/g (23.5%. MBF repeatability improved with SOC-On at stress (p<0.001 and tended to improve with RBC-Off at both rest and stress (p<0.08. DV and ROI did not significantly influence repeatability. The Delay-On model was overdetermined and did not reliably converge. Conclusion. MBF and MFR test-retest repeatability were the best with dual spillover correction, left atrium blood input function, and global DV.

  15. Antarctic Ice Sheet Slope and Aspect Based on Icesat's Repeat Orbit Measurement

    Science.gov (United States)

    Yuan, L.; Li, F.; Zhang, S.; Xie, S.; Xiao, F.; Zhu, T.; Zhang, Y.

    2017-09-01

    Accurate information of ice sheet surface slope is essential for estimating elevation change by satellite altimetry measurement. A study is carried out to recover surface slope of Antarctic ice sheet from Ice, Cloud and land Elevation Satellite (ICESat) elevation measurements based on repeat orbits. ICESat provides repeat ground tracks within 200 meters in cross-track direction and 170 meters in along-track direction for most areas of Antarctic ice sheet. Both cross-track and along-track surface slopes could be obtained by adjacent repeat ground tracks. Combining those measurements yields a surface slope model with resolution of approximately 200 meters. An algorithm considering elevation change is developed to estimate the surface slope of Antarctic ice sheet. Three Antarctic Digital Elevation Models (DEMs) were used to calculate surface slopes. The surface slopes from DEMs are compared with estimates by using in situ GPS data in Dome A, the summit of Antarctic ice sheet. Our results reveal an average surface slope difference of 0.02 degree in Dome A. High resolution remote sensing images are also used in comparing the results derived from other DEMs and this paper. The comparison implies that our results have a slightly better coherence with GPS observation than results from DEMs, but our results provide more details and perform higher accuracy in coastal areas because of the higher resolution for ICESat measurements. Ice divides are estimated based on the aspect, and are weakly consistent with ice divides from other method in coastal regions.

  16. Acute caffeine effect on repeatedly measured P300

    OpenAIRE

    Pan, Jingbo; Takeshita, Tatsuya; Morimoto, Kanehisa

    2000-01-01

    The acute effect of a single-dose of caffeine on the P300 event-related brain potential (ERP) was assessed in a study using a repeatedly presented auditory oddball button-press task. A dose (5mg/kg body-weight) of either caffeine or placebo lactose, dissolved in a cup of decaffeinated coffee, was administered double-blindly to coffee drinkers who had abstained from coffee for 24hrs, with the presentation order of the sessions counterbalanced and separated by 2–4 weeks. The caffeine-treatment ...

  17. Repeatability and Reproducibility of Compression Strength Measurements Conducted According to ASTM E9

    Science.gov (United States)

    Luecke, William E.; Ma, Li; Graham, Stephen M.; Adler, Matthew A.

    2010-01-01

    Ten commercial laboratories participated in an interlaboratory study to establish the repeatability and reproducibility of compression strength tests conducted according to ASTM International Standard Test Method E9. The test employed a cylindrical aluminum AA2024-T351 test specimen. Participants measured elastic modulus and 0.2 % offset yield strength, YS(0.2 % offset), using an extensometer attached to the specimen. The repeatability and reproducibility of the yield strength measurement, expressed as coefficient of variations were cv(sub r)= 0.011 and cv(sub R)= 0.020 The reproducibility of the test across the laboratories was among the best that has been reported for uniaxial tests. The reported data indicated that using diametrically opposed extensometers, instead of a single extensometer doubled the precision of the test method. Laboratories that did not lubricate the ends of the specimen measured yield stresses and elastic moduli that were smaller than those measured in laboratories that lubricated the specimen ends. A finite element analysis of the test specimen deformation for frictionless and perfect friction could not explain the discrepancy, however. The modulus measured from stress-strain data were reanalyzed using a technique that finds the optimal fit range, and applies several quality checks to the data. The error in modulus measurements from stress-strain curves generally increased as the fit range decreased to less than 40 % of the stress range.

  18. REPEATABILITY AND ACCURACY OF EXOPLANET ECLIPSE DEPTHS MEASURED WITH POST-CRYOGENIC SPITZER

    Energy Technology Data Exchange (ETDEWEB)

    Ingalls, James G.; Krick, J. E.; Carey, S. J.; Stauffer, John R.; Lowrance, Patrick J.; Grillmair, Carl J.; Capak, Peter; Glaccum, William; Laine, Seppo; Surace, Jason; Storrie-Lombardi, Lisa [Spitzer Science Center, California Institute of Technology, 1200 E California Boulevard, Mail Code 314-6, Pasadena, CA 91125 (United States); Buzasi, Derek [Department of Chemistry and Physics, Florida Gulf Coast University, Fort Myers, FL 33965 (United States); Deming, Drake [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Diamond-Lowe, Hannah; Stevenson, Kevin B. [Department of Astronomy and Astrophysics, University of Chicago, 5640 S Ellis Avenue, Chicago, IL 60637 (United States); Evans, Thomas M. [School of Physics, University of Exeter, EX4 4QL Exeter (United Kingdom); Morello, G. [Department of Physics and Astronomy, University College London, Gower Street, WC1 E6BT (United Kingdom); Wong, Ian, E-mail: ingalls@ipac.caltech.edu [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)

    2016-08-01

    We examine the repeatability, reliability, and accuracy of differential exoplanet eclipse depth measurements made using the InfraRed Array Camera (IRAC) on the Spitzer Space Telescope during the post-cryogenic mission. We have re-analyzed an existing 4.5 μ m data set, consisting of 10 observations of the XO-3b system during secondary eclipse, using seven different techniques for removing correlated noise. We find that, on average, for a given technique, the eclipse depth estimate is repeatable from epoch to epoch to within 156 parts per million (ppm). Most techniques derive eclipse depths that do not vary by more than a factor 3 of the photon noise limit. All methods but one accurately assess their own errors: for these methods, the individual measurement uncertainties are comparable to the scatter in eclipse depths over the 10 epoch sample. To assess the accuracy of the techniques as well as to clarify the difference between instrumental and other sources of measurement error, we have also analyzed a simulated data set of 10 visits to XO-3b, for which the eclipse depth is known. We find that three of the methods (BLISS mapping, Pixel Level Decorrelation, and Independent Component Analysis) obtain results that are within three times the photon limit of the true eclipse depth. When averaged over the 10 epoch ensemble,  5 out of 7 techniques come within 60 ppm of the true value. Spitzer exoplanet data, if obtained following current best practices and reduced using methods such as those described here, can measure repeatable and accurate single eclipse depths, with close to photon-limited results.

  19. Repeatability and Comparison of Keratometry Values Measured with Potec PRK-6000 Autorefractometer, IOLMaster, and Pentacam

    Directory of Open Access Journals (Sweden)

    Adem Türk

    2014-05-01

    Full Text Available Objectives: To research the repeatability and intercompatibility of keratometry values measured with Potec PRK-6000 autorefractometer, IOL Master, and Pentacam. Materials and Methods: In this prospective study, consecutive measurements were performed in two different sessions with the mentioned three devices on 110 eyes of 55 subjects who had no additional ocular pathology except for refraction error. The consistency of flat and steep keratometry, average keratometry, and corneal astigmatism values obtained in both sessions was compared by using intraclass correlation coefficient (ICC. The measurement differences between the devices were statistically compared as well. Results: The mean age of the study subjects was 23.05±3.01 (18-30 years. ICC values of average keratometry measurements obtained in the sessions were 0.996 for Potec PRK-6000 autorefractometer, 0.997 for IOL Master, and 0.999 for Pentacam. There was high compatibility between the three devices in terms of average keratometry values in Bland-Altman analysis. However, there were statistically significant differences between the devices in terms of parameters other than corneal astigmatism. Conclusion: The repeatability of the three devices was found considerably high in keratometry measurements. However, it is not appropriate for these devices to be substituted for each other in keratometry measurements. (Turk J Ophthalmol 2014; 44: 179-83

  20. Characterisation and measurement of signals generated by DVB-H 'gap-filler' repeaters

    International Nuclear Information System (INIS)

    Baldini, M.; Barellini, A.; Bogi, L.; Licitra, G.; Silvi, A. M.; Zari, A.

    2009-01-01

    DVB-H (Digital Video Broadcasting Hand-held) is the standard developed by DVB Project and approved by ETSI with the aim of providing the reception of DVB signals even in mobility but also data transfers and multimedia services. The introduction and development of the DVB-H system is still ongoing. In this context, this work focuses on the temporal trend of electromagnetic impact of an urban DVB-H repeater (called 'gap-filler') for exposure assessment purposes; it also describes a method for its measurement by means of narrow band instrumental chains. (authors)

  1. Measuring environmental change in forest ecosystems by repeated soil sampling: a North American perspective

    Science.gov (United States)

    Lawrence, Gregory B.; Fernandez, Ivan J.; Richter, Daniel D.; Ross, Donald S.; Hazlett, Paul W.; Bailey, Scott W.; Oiumet, Rock; Warby, Richard A.F.; Johnson, Arthur H.; Lin, Henry; Kaste, James M.; Lapenis, Andrew G.; Sullivan, Timothy J.

    2013-01-01

    Environmental change is monitored in North America through repeated measurements of weather, stream and river flow, air and water quality, and most recently, soil properties. Some skepticism remains, however, about whether repeated soil sampling can effectively distinguish between temporal and spatial variability, and efforts to document soil change in forest ecosystems through repeated measurements are largely nascent and uncoordinated. In eastern North America, repeated soil sampling has begun to provide valuable information on environmental problems such as air pollution. This review synthesizes the current state of the science to further the development and use of soil resampling as an integral method for recording and understanding environmental change in forested settings. The origins of soil resampling reach back to the 19th century in England and Russia. The concepts and methodologies involved in forest soil resampling are reviewed and evaluated through a discussion of how temporal and spatial variability can be addressed with a variety of sampling approaches. Key resampling studies demonstrate the type of results that can be obtained through differing approaches. Ongoing, large-scale issues such as recovery from acidification, long-term N deposition, C sequestration, effects of climate change, impacts from invasive species, and the increasing intensification of soil management all warrant the use of soil resampling as an essential tool for environmental monitoring and assessment. Furthermore, with better awareness of the value of soil resampling, studies can be designed with a long-term perspective so that information can be efficiently obtained well into the future to address problems that have not yet surfaced.

  2. Repeatability of Lucas chamber measurements; Powtarzalnosc pomiarow za pomoca komory Lucasa

    Energy Technology Data Exchange (ETDEWEB)

    Machaj, B.

    1997-12-31

    Results of investigations concerning the repeatability of the measurements carried out with Lucas chamber are presented in the report. The Lucas chamber is used for determination of radon concentration in air, and the Lucas chamber itself is measured in a laboratory stand. The repeatability of measurements is {+-}5.4% relative. The error due to instability of measuring channel gain is estimated to be 2-3% relative. (author). 5 refs, 17 figs, 5 tabs.

  3. Statistical Validation for Clinical Measures: Repeatability and Agreement of Kinect™-Based Software.

    Science.gov (United States)

    Lopez, Natalia; Perez, Elisa; Tello, Emanuel; Rodrigo, Alejandro; Valentinuzzi, Max E

    2018-01-01

    The rehabilitation process is a fundamental stage for recovery of people's capabilities. However, the evaluation of the process is performed by physiatrists and medical doctors, mostly based on their observations, that is, a subjective appreciation of the patient's evolution. This paper proposes a tracking platform of the movement made by an individual's upper limb using Kinect sensor(s) to be applied for the patient during the rehabilitation process. The main contribution is the development of quantifying software and the statistical validation of its performance, repeatability, and clinical use in the rehabilitation process. The software determines joint angles and upper limb trajectories for the construction of a specific rehabilitation protocol and quantifies the treatment evolution. In turn, the information is presented via a graphical interface that allows the recording, storage, and report of the patient's data. For clinical purposes, the software information is statistically validated with three different methodologies, comparing the measures with a goniometer in terms of agreement and repeatability. The agreement of joint angles measured with the proposed software and goniometer is evaluated with Bland-Altman plots; all measurements fell well within the limits of agreement, meaning interchangeability of both techniques. Additionally, the results of Bland-Altman analysis of repeatability show 95% confidence. Finally, the physiotherapists' qualitative assessment shows encouraging results for the clinical use. The main conclusion is that the software is capable of offering a clinical history of the patient and is useful for quantification of the rehabilitation success. The simplicity, low cost, and visualization possibilities enhance the use of the software Kinect for rehabilitation and other applications, and the expert's opinion endorses the choice of our approach for clinical practice. Comparison of the new measurement technique with established

  4. Measuring environmental change in forest ecosystems by repeated soil sampling: A North American perspective

    Science.gov (United States)

    Gregory B. Lawrence; Ivan J. Fernandez; Daniel D. Richter; Donald S. Ross; Paul W. Hazlett; Scott W. Bailey; Rock Ouimet; Richard A. F. Warby; Arthur H. Johnson; Henry Lin; James M. Kaste; Andrew G. Lapenis; Timothy J. Sullivan

    2013-01-01

    Environmental change is monitored in North America through repeated measurements of weather, stream and river flow, air and water quality, and most recently, soil properties. Some skepticism remains, however, about whether repeated soil sampling can effectively distinguish between temporal and spatial variability, and efforts to document soil change in forest...

  5. Preventive maintenance measures and repeat tests on actuators

    International Nuclear Information System (INIS)

    Hueren, H.

    1990-01-01

    At Biblis Nuclear Power Station, about 1500 electrical actuators and variable speed drives of various model ranges and with various driving end speeds and actuating times are installed and about 600 of these are located in important safety engineering systems. In order to optimize the preventive maintenance measures on the drives, a data bank has been established into which are stored, in addition to the fixed type data of each drive, inter alia, statements about location of application, valve type, inspection cycle, calendar year of next maintenance, findings during inspection measures and causes of faults. Before each unit inspection, in addition to the inspection lists, the maintenance and installation records and also the associated job instructions are produced from this data processing equipment. (orig.) [de

  6. Typing Method for the QUB11a Locus of Mycobacterium tuberculosis: IS6110 Insertions and Tandem Repeat Analysis

    Directory of Open Access Journals (Sweden)

    Eriko Maeda-Mitani

    2016-01-01

    Full Text Available QUB11a is used as a locus for variable number of tandem repeats (VNTR analysis of Mycobacterium tuberculosis Beijing lineage. However, amplification of QUB11a occasionally produces large fragments (>1,400 bp that are not easily measured by capillary electrophoresis because of a lack of the typical stutter peak patterns that are used for counting repeat numbers. IS6110 insertion may complicate VNTR analysis of large QUB11a fragments in M. tuberculosis. We established a method for determining both tandem repeat numbers and IS6110 insertion in the QUB11a locus of M. tuberculosis using capillary electrophoresis analysis and BsmBI digestion. All 29 large QUB11a fragments (>1,200 bp investigated contained IS6110 insertions and varied in the number of repeats (18 patterns and location of IS6110 insertions. This method allows VNTR analysis with high discrimination.

  7. Methods for measuring shrinkage

    OpenAIRE

    Chapman, Paul; Templar, Simon

    2006-01-01

    This paper presents findings from research amongst European grocery retailers into their methods for measuring shrinkage. The findings indicate that: there is no dominant method for valuing or stating shrinkage; shrinkage in the supply chain is frequently overlooked; data is essential in pinpointing where and when loss occurs and that many retailers collect data at the stock-keeping unit (SKU) level and do so every 6 months. These findings reveal that it is difficult to benc...

  8. Fine typing of methicillin-resistant Staphylococcus aureus isolates using direct repeat unit and staphylococcal interspersed repeat unit typing methods.

    Science.gov (United States)

    Ho, Cheng-Mao; Ho, Mao-Wang; Li, Chi-Yuan; Lu, Jang-Jih

    2015-08-01

    Methicillin-resistant Staphylococcus aureus (MRSA) typing is an important epidemiologic tool for monitoring trends and preventing outbreaks. However, the efficiency of various MRSA typing methods for each SCCmec MRSA isolate is rarely evaluated. A total of 157 MRSA isolates from four different regions in Taiwan were typed with five different molecular methods, including SCCmec typing, multilocus sequence typing (MLST), spa typing, mec-associated direct repeat unit (dru) copy number determination, and staphylococcal interspersed repeat unit (SIRU) profiling. There were four SCCmec types, eight MLST types, 15 spa types, 11 dru types, and 31 SIRU profiles. The most common type determined by each molecular typing method was SCCmec III (115 isolates, 73.2%), ST239 (99 isolates, 63.1%), t037 (107 isolates, 68.2%), 14 dru copies (76 isolates, 48.4%), and SIRU profile 3013722 (102 isolates, 65%), respectively. When using the combination of MLST, spa typing, and dru copy number, ST5-t002-4 (n = 8), ST239-t037-14 (n = 68), ST59-t437-9 (n = 9), and ST59-t437-11 (n = 6) were found to be the most common types of SCCmec types II (n = 9), III (n = 115), IV (n = 21), and VT (n = 11) isolates, respectively. SCCmec type III isolates were further classified into 11 dru types. Of the 21 SCCmec type IV isolates, 14 SIRU profiles were found. Seven SIRU patterns were observed in the 11 SCCmec type VT isolates. Different typing methods showed a similar Hunter-Gaston discrimination index among the 157 MRSA isolates. However, dru and SIRU typing methods had a better discriminatory power for SCCmec type III and SCCmec types IV and VT isolates, respectively, suggesting that dru and SIRU can be used to further type these isolates. Copyright © 2013. Published by Elsevier B.V.

  9. The repeatability of three diagnostic methods (visual using ICDAS II, laser fluorescence, and radiographic) for early caries detection

    Science.gov (United States)

    Sukmasari, S.; Lestari, W.; Ko, B. B.; Noh, Z.; Asmail, N.; Yaacob, N.

    2017-08-01

    Newly introduced ICDAS II as a visual method, laser fluorescence as another technique that have ability to quantify early mineral loss of tooth structure and intra oral radiograph, are methods can be used in the clinic. To provide standardization for comprehensive caries management at an early stage, all methods supposed to be tested between users. The objective of this research is to evaluate the repeatability of each system. It is a comparative cross sectional study using 100 extracted permanent teeth without obvious cavitation (premolar & molar) that were collected and stored in thymol solution. The teeth were embedded on the wax block and labeled with numbers. All 5 surfaces were examined by 5 examiners using visual (ICDAS II), laser fluorescence (LF) and radiographic examination. The data were then analyzed to measure intra and inter examiner repeatability using Cronbach’s alpha and inter-item correlation matrix. Intra-examiner repeatability for all examiners was >0.7. Chronbach’s a value for inter-examiner repeatability for ICDAS II was >0.8 on 3 surfaces except on buccal and lingual. LF exhibit repeatability of >0.8 on all surfaces. Radiograph shows a low value of inter examiner repeatability (students for inter-item correlation while the 2nd and 3rd reading of LF displays the best agreement. ICDAS II score favors more non-invasive treatment compared to LF. ICDAS II showed good repeatability except on buccal and lingual surfaces. In line with some of the previous study, ICDAS II is applicable for caries detection in daily clinical basis. Laser fluorescence exhibits the highest repeatability while the radiograph showed weak inter-examiner repeatability. Treatment decisions of ICDAS II propose more preventive treatment for early caries lesions compared to laser fluorescence.

  10. Alcohol intake and colorectal cancer: a comparison of approaches for including repeated measures of alcohol consumption

    DEFF Research Database (Denmark)

    Thygesen, Lau Caspar; Wu, Kana; Grønbaek, Morten

    2008-01-01

    BACKGROUND: In numerous studies, alcohol intake has been found to be positively associated with colorectal cancer risk. However, the majority of studies included only one exposure measurement, which may bias the results if long-term intake is relevant.METHODS: We compared different approaches...... for including repeated measures of alcohol intake among 47,432 US men enrolled in the Health Professionals Follow-up Study. Questionnaires including questions on alcohol intake had been completed in 1986, 1990, 1994, and 1998. The outcome was incident colorectal cancer during follow-up from 1986 to 2002.RESULTS......: During follow-up, 868 members of the cohort experienced colorectal cancer. Baseline, updated, and cumulative average alcohol intakes were positively associated with colorectal cancer, with only minor differences among the approaches. These results support moderately increased risk for intake >30 g...

  11. Theoretical repeatability assessment without repetitive measurements in gradient high-performance liquid chromatography.

    Science.gov (United States)

    Kotani, Akira; Tsutsumi, Risa; Shoji, Asaki; Hayashi, Yuzuru; Kusu, Fumiyo; Yamamoto, Kazuhiro; Hakamata, Hideki

    2016-07-08

    This paper puts forward a time and material-saving method for evaluating the repeatability of area measurements in gradient HPLC with UV detection (HPLC-UV), based on the function of mutual information (FUMI) theory which can theoretically provide the measurement standard deviation (SD) and detection limits through the stochastic properties of baseline noise with no recourse to repetitive measurements of real samples. The chromatographic determination of terbinafine hydrochloride and enalapril maleate is taken as an example. The best choice of the number of noise data points, inevitable for the theoretical evaluation, is shown to be 512 data points (10.24s at 50 point/s sampling rate of an A/D converter). Coupled with the relative SD (RSD) of sample injection variability in the instrument used, the theoretical evaluation is proved to give identical values of area measurement RSDs to those estimated by the usual repetitive method (n=6) over a wide concentration range of the analytes within the 95% confidence intervals of the latter RSD. The FUMI theory is not a statistical one, but the "statistical" reliability of its SD estimates (n=1) is observed to be as high as that attained by thirty-one measurements of the same samples (n=31). Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Measured attenuation correction methods

    International Nuclear Information System (INIS)

    Ostertag, H.; Kuebler, W.K.; Doll, J.; Lorenz, W.J.

    1989-01-01

    Accurate attenuation correction is a prerequisite for the determination of exact local radioactivity concentrations in positron emission tomography. Attenuation correction factors range from 4-5 in brain studies to 50-100 in whole body measurements. This report gives an overview of the different methods of determining the attenuation correction factors by transmission measurements using an external positron emitting source. The long-lived generator nuclide 68 Ge/ 68 Ga is commonly used for this purpose. The additional patient dose from the transmission source is usually a small fraction of the dose due to the subsequent emission measurement. Ring-shaped transmission sources as well as rotating point or line sources are employed in modern positron tomographs. By masking a rotating line or point source, random and scattered events in the transmission scans can be effectively suppressed. The problems of measured attenuation correction are discussed: Transmission/emission mismatch, random and scattered event contamination, counting statistics, transmission/emission scatter compensation, transmission scan after administration of activity to the patient. By using a double masking technique simultaneous emission and transmission scans become feasible. (orig.)

  13. Image analysis as a non-destructive method to assess regrowth of weeds after repeated flame weeding

    DEFF Research Database (Denmark)

    Rask, Anne Merete; Kristoffersen, Palle; Andreasen, Christian

    2013-01-01

    picture of the long-term effect of repeated treatments. Image analysis was most useful for assessing the effect of repeated treatments when weed cover was relatively low (below 40%) and when plots contained relatively much withered plant material. However, when weed cover is close to 100%, dry weight......, and therefore it may influence the long-term effect of repeated treatments. Visual assessment of weed cover or image analysis do not affect the remaining parts of the weed plants after treatment, but the methods may have other disadvantages. In order to evaluate and compare three methods we measured changes...... in vegetation cover of perennial ryegrass after flaming by (1) a simple image analysis programme counting green pixels, (2) visual assessment of images and (3) by taking biomass samples. Plants were flame treated with eight different dosages (0, 20, 30, 35, 45, 60, 90 and 180 kg propane ha-1) and with various...

  14. Repeated dose titration versus age-based method in electroconvulsive therapy: a pilot study

    NARCIS (Netherlands)

    Aten, J.J.; Oudega, M.L.; van Exel, E.; Stek, M.L.; van Waarde, J.A.

    2015-01-01

    In electroconvulsive therapy (ECT), a dose titration method (DTM) was suggested to be more individualized and therefore more accurate than formula-based dosing methods. A repeated DTM (every sixth session and dose adjustment accordingly) was compared to an age-based method (ABM) regarding treatment

  15. Measurement repeatability of tibial tuberosity-trochlear groove offset distance in red fox (Vulpes vulpes) cadavers

    NARCIS (Netherlands)

    Miles, J.E.; Jensen, B.R.; Kirpensteijn, J.; Svalastoga, E.L.; Eriksen, T.

    2013-01-01

    Abstract OBJECTIVE: To describe CT image reconstruction criteria for measurement of the tibial tuberosity-trochlear groove (TT-TG) offset distance, evaluate intra- and inter-reconstruction repeatability, and identify key sources of error in the measurement technique, as determined in vulpine hind

  16. New method for remote and repeatable monitoring of intraocular pressure variations.

    Science.gov (United States)

    Margalit, Israel; Beiderman, Yevgeny; Skaat, Alon; Rosenfeld, Elkanah; Belkin, Michael; Tornow, Ralf-Peter; Mico, Vicente; Garcia, Javier; Zalevsky, Zeev

    2014-02-01

    We present initial steps toward a new measurement device enabling high-precision, noncontact remote and repeatable monitoring of intraocular pressure (IOP)-based on an innovative measurement principle. Using only a camera and a laser source, the device measures IOP by tracking the secondary speckle pattern trajectories produced by the reflection of an illuminating laser beam from the iris or the sclera. The device was tested on rabbit eyes using two different methods to modify IOP: via an infusion bag and via mechanical pressure. In both cases, the eyes were stimulated with increasing and decreasing ramps of the IOP. As IOP variations changed the speckle distributions reflected back from the eye, data were recorded under various optical configurations to define and optimize the best experimental configuration for the IOP extraction. The association between the data provided by our proposed device and that resulting from controlled modification of the IOP was assessed, revealing high correlation (R2=0.98) and sensitivity and providing a high-precision measurement (5% estimated error) for the best experimental configuration. Future steps will be directed toward applying the proposed measurement principle in clinical trials for monitoring IOP with human subjects.

  17. Spatial Cluster Detection for Repeatedly Measured Outcomes while Accounting for Residential History

    OpenAIRE

    Cook, Andrea J.; Gold, Diane R.; Li, Yi

    2009-01-01

    Spatial cluster detection has become an important methodology in quantifying the effect of hazardous exposures. Previous methods have focused on cross-sectional outcomes that are binary or continuous. There are virtually no spatial cluster detection methods proposed for longitudinal outcomes. This paper proposes a new spatial cluster detection method for repeated outcomes using cumulative geographic residuals. A major advantage of this method is its ability to readily incorporate information ...

  18. Testing Mean Differences among Groups: Multivariate and Repeated Measures Analysis with Minimal Assumptions.

    Science.gov (United States)

    Bathke, Arne C; Friedrich, Sarah; Pauly, Markus; Konietschke, Frank; Staffen, Wolfgang; Strobl, Nicolas; Höller, Yvonne

    2018-03-22

    To date, there is a lack of satisfactory inferential techniques for the analysis of multivariate data in factorial designs, when only minimal assumptions on the data can be made. Presently available methods are limited to very particular study designs or assume either multivariate normality or equal covariance matrices across groups, or they do not allow for an assessment of the interaction effects across within-subjects and between-subjects variables. We propose and methodologically validate a parametric bootstrap approach that does not suffer from any of the above limitations, and thus provides a rather general and comprehensive methodological route to inference for multivariate and repeated measures data. As an example application, we consider data from two different Alzheimer's disease (AD) examination modalities that may be used for precise and early diagnosis, namely, single-photon emission computed tomography (SPECT) and electroencephalogram (EEG). These data violate the assumptions of classical multivariate methods, and indeed classical methods would not have yielded the same conclusions with regards to some of the factors involved.

  19. Maintaining confidentiality in prospective studies: anonymous repeated measurements via email (ARME) procedure.

    Science.gov (United States)

    Carli, Vladimir; Hadlaczky, Gergö; Wasserman, Camilla; Stingelin-Giles, Nicola; Reiter-Theil, Stella; Wasserman, Danuta

    2012-02-01

    Respecting and protecting the confidentiality of data and the privacy of individuals regarding the information that they have given as participants in a research project is a cornerstone of complying with accepted research standards. However, in longitudinal studies, establishing and maintaining privacy is often challenging because of the necessity of repeated contact with participants. A novel internet-based solution is introduced here, which maintains privacy while at the same time ensures linkage of data to individual participants in a repeated measures design. With the use of the anonymous repeated measurements via email (ARME) procedure, two separate one-way communication systems are established through ad hoc email accounts and a secure study website. Strengths and limitations of the approach are discussed.

  20. Convergence of repeated quantum nondemolition measurements and wave-function collapse

    International Nuclear Information System (INIS)

    Bauer, Michel; Bernard, Denis

    2011-01-01

    Motivated by recent experiments on quantum trapped fields, we give a rigorous proof that repeated indirect quantum nondemolition (QND) measurements converge to the collapse of the wave function as predicted by the postulates of quantum mechanics for direct measurements. We also relate the rate of convergence toward the collapsed wave function to the relative entropy of each indirect measurement, a result which makes contact with information theory.

  1. Intra-session repeatability of iridocorneal angle measurements provided by a Scheimpflug photography-based system in healthy eyes

    OpenAIRE

    Ruiz-Belda, Clara; Piñero, David P.; Ruiz Fortes, Pedro; Soto-Negro, Roberto; Moya, Myriam; Pérez Cambrodí, Rafael J.; Artola, Alberto

    2016-01-01

    Purpose: The purpose of this study was to evaluate intra-session repeatability of measurements of the iridocorneal angle at different meridians in the nasal and temporal areas in healthy eyes using the Sirius Scheimpflug photography-based system in glaucoma analysis mode. Methods: A total of 43 eyes of 43 patients ranging in age from 36 to 79 years were enrolled in the study. All eyes received a comprehensive ophthalmologic examination including a complete anterior segment analysis with the C...

  2. Use of the Counseling Center Assessment of Psychological Symptoms 62 (CCAPS-62) as a Repeated Measure

    Science.gov (United States)

    Ghosh, Arpita; Rieder Bennett, Sara; Martin, Juanita K.

    2018-01-01

    The purpose of this initial, exploratory study was to examine the utility of the Counseling Center Assessment of Psychological Symptoms-62 (CCAPS-62) as a repeated measure tool at one university counseling center. This study investigated whether clients engaged in individual counseling changed in symptomology while in treatment and when (e.g.,…

  3. Use of Repeated Blood Pressure and Cholesterol Measurements to Improve Cardiovascular Disease Risk Prediction

    DEFF Research Database (Denmark)

    Paige, Ellie; Barrett, Jessica; Pennells, Lisa

    2017-01-01

    The added value of incorporating information from repeated blood pressure and cholesterol measurements to predict cardiovascular disease (CVD) risk has not been rigorously assessed. We used data on 191,445 adults from the Emerging Risk Factors Collaboration (38 cohorts from 17 countries with data...

  4. Counterbalancing and Other Uses of Repeated-Measures Latin-Square Designs: Analyses and Interpretations.

    Science.gov (United States)

    Reese, Hayne W.

    1997-01-01

    Recommends that when repeated-measures Latin-square designs are used to counterbalance treatments across a procedural variable or to reduce the number of treatment combinations given to each participant, effects be analyzed statistically, and that in all uses, researchers consider alternative interpretations of the variance associated with the…

  5. Parsimonious Structural Equation Models for Repeated Measures Data, with Application to the Study of Consumer Preferences

    Science.gov (United States)

    Elrod, Terry; Haubl, Gerald; Tipps, Steven W.

    2012-01-01

    Recent research reflects a growing awareness of the value of using structural equation models to analyze repeated measures data. However, such data, particularly in the presence of covariates, often lead to models that either fit the data poorly, are exceedingly general and hard to interpret, or are specified in a manner that is highly data…

  6. Cross-trimester repeated measures testing for Down's syndrome screening: an assessment.

    LENUS (Irish Health Repository)

    Wright, D

    2010-07-01

    To provide estimates and confidence intervals for the performance (detection and false-positive rates) of screening for Down\\'s syndrome using repeated measures of biochemical markers from first and second trimester maternal serum samples taken from the same woman.

  7. Near-Peer Teaching in Paramedic Education: A Repeated Measures Design

    Science.gov (United States)

    Williams, Brett; Nguyen, David

    2017-01-01

    The transition of the Australian paramedic discipline from vocation education and training to the higher education sector has seen a sharp rise in interest in near-peer teaching (NPT). The objective of this study was to examine satisfaction levels of NPT over one academic semester among undergraduate paramedic students. A repeated measured design…

  8. Spatial Component Position in Total Hip Arthroplasty. Accuracy and repeatability with a new CT method

    International Nuclear Information System (INIS)

    Olivecrona, H.

    2003-01-01

    Purpose: 3D detection of centerpoints of prosthetic cup and head after total hip arthroplasty (THA) using CT. Material and Methods: Two CT examinations, 10 min apart, were obtained from each of 10 patients after THA. Two independent examiners placed landmarks in images of the prosthetic cup and head. All landmarking was repeated after 1 week. Centerpoints were calculated and compared. Results: Within volumes, all measurements of centerpoints of cup and head fell, with a 95% confidence, within one CT-voxel of any other measurement of the same object. Across two volumes, the mean error of distance between center of cup and prosthetic head was 1.4 mm (SD 0.73). Intra- and interobserver 95% accuracy limit was below 2 mm within and below 3 mm across volumes. No difference between intra- and interobserver measurements occurred. A formula for converting finite sets of point landmarks in the radiolucent tread of the cup to a centerpoint was stable. The percent difference of the landmark distances from a calculated spherical surface was within one CT-voxel. This data was normally distributed and not dependent on observer or trial. Conclusion: The true 3D position of the centers of cup and prosthetic head can be detected using CT. Spatial relationship between the components can be analyzed visually and numerically

  9. Spatial Component Position in Total Hip Arthroplasty. Accuracy and repeatability with a new CT method

    Energy Technology Data Exchange (ETDEWEB)

    Olivecrona, H. [Soedersjukhuset, Stockholm (Sweden). Dept. of Hand Surgery; Weidenhielm, L. [Karolinska Hospital, Stockholm (Sweden). Dept. of Orthopedics; Olivecrona, L. [Karolinska Hospital, Stockholm (Sweden). Dept. of Radiology; Noz, M.E. [New York Univ. School of Medicine, NY (United States). Dept. of Radiology; Maguire, G.Q. [Royal Inst. of Tech., Kista (Sweden). Inst. for Microelectronics and Information Technology; Zeleznik, M. P. [Univ. of Utah, Salt Lake City, UT (United States). Dept. of Radiation Oncology; Svensson, L. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Mathematics; Jonson, T. [Eskadern Foeretagsutveckling AB, Goeteborg (Sweden)

    2003-03-01

    Purpose: 3D detection of centerpoints of prosthetic cup and head after total hip arthroplasty (THA) using CT. Material and Methods: Two CT examinations, 10 min apart, were obtained from each of 10 patients after THA. Two independent examiners placed landmarks in images of the prosthetic cup and head. All landmarking was repeated after 1 week. Centerpoints were calculated and compared. Results: Within volumes, all measurements of centerpoints of cup and head fell, with a 95% confidence, within one CT-voxel of any other measurement of the same object. Across two volumes, the mean error of distance between center of cup and prosthetic head was 1.4 mm (SD 0.73). Intra- and interobserver 95% accuracy limit was below 2 mm within and below 3 mm across volumes. No difference between intra- and interobserver measurements occurred. A formula for converting finite sets of point landmarks in the radiolucent tread of the cup to a centerpoint was stable. The percent difference of the landmark distances from a calculated spherical surface was within one CT-voxel. This data was normally distributed and not dependent on observer or trial. Conclusion: The true 3D position of the centers of cup and prosthetic head can be detected using CT. Spatial relationship between the components can be analyzed visually and numerically.

  10. Masonry fireplace emissions test method: Repeatability and sensitivity to fueling protocol.

    Science.gov (United States)

    Stern, C H; Jaasma, D R; Champion, M R

    1993-03-01

    A test method for masonry fireplaces has been evaluated during testing on six masonry fireplace configurations. The method determines carbon monoxide and particulate matter emission rates (g/h) and factors (g/kg) and does not require weighing of the appliance to determine the timing of fuel loading.The intralaboratory repeatability of the test method has been determined from multiple tests on the six fireplaces. For the tested fireplaces, the ratio of the highest to lowest measured PM rate averaged 1.17 and in no case was greater than 1.32. The data suggest that some of the variation is due to differences in fuel properties.The influence of fueling protocol on emissions has also been studied. A modified fueling protocol, tested in large and small fireplaces, reduced CO and PM emission factors by roughly 40% and reduced CO and PM rates from 0 to 30%. For both of these fireplaces, emission rates were less sensitive to fueling protocol than emission factors.

  11. Repeatability and variation of region-of-interest methods using quantitative diffusion tensor MR imaging of the brain

    International Nuclear Information System (INIS)

    Hakulinen, Ullamari; Brander, Antti; Ryymin, Pertti; Öhman, Juha; Soimakallio, Seppo; Helminen, Mika; Dastidar, Prasun; Eskola, Hannu

    2012-01-01

    Diffusion tensor imaging (DTI) is increasingly used in various diseases as a clinical tool for assessing the integrity of the brain’s white matter. Reduced fractional anisotropy (FA) and an increased apparent diffusion coefficient (ADC) are nonspecific findings in most pathological processes affecting the brain’s parenchyma. At present, there is no gold standard for validating diffusion measures, which are dependent on the scanning protocols, methods of the softwares and observers. Therefore, the normal variation and repeatability effects on commonly-derived measures should be carefully examined. Thirty healthy volunteers (mean age 37.8 years, SD 11.4) underwent DTI of the brain with 3T MRI. Region-of-interest (ROI) -based measurements were calculated at eleven anatomical locations in the pyramidal tracts, corpus callosum and frontobasal area. Two ROI-based methods, the circular method (CM) and the freehand method (FM), were compared. Both methods were also compared by performing measurements on a DTI phantom. The intra- and inter-observer variability (coefficient of variation, or CV%) and repeatability (intra-class correlation coefficient, or ICC) were assessed for FA and ADC values obtained using both ROI methods. The mean FA values for all of the regions were 0.663 with the CM and 0.621 with the FM. For both methods, the FA was highest in the splenium of the corpus callosum. The mean ADC value was 0.727 ×10 -3 mm 2 /s with the CM and 0.747 ×10 -3 mm 2 /s with the FM, and both methods found the ADC to be lowest in the corona radiata. The CV percentages of the derived measures were < 13% with the CM and < 10% with the FM. In most of the regions, the ICCs were excellent or moderate for both methods. With the CM, the highest ICC for FA was in the posterior limb of the internal capsule (0.90), and with the FM, it was in the corona radiata (0.86). For ADC, the highest ICC was found in the genu of the corpus callosum (0.93) with the CM and in the uncinate

  12. Comparison of Repeated Measurement Design and Mixed Models in Evaluation of the Entonox Effect on Labor Pain

    Directory of Open Access Journals (Sweden)

    Nasim Karimi

    2017-01-01

    Full Text Available Background & objectives: In many medical studies, the response variable is measured repeatedly over time to evaluate the treatment effect that is known as longitudinal study. The analysis method for this type of data is repeated measures ANOVA that uses only one correlation structure and the results are not valid with inappropriate correlation structure. To avoid this problem, a convenient alternative is mixed models. So, the aim of this study was to compare of mixed and repeated measurement models for examination of the Entonox effect on the labor pain. Methods: This experimental study was designed to compare the effect of Entonox and oxygen inhalation on pain relief between two groups. Data were analyzed using repeated measurement and mixed models with different correlation structures. Selection and comparison of proper correlation structures performed using Akaike information criterion, Bayesian information criterion and restricted log-likelihood. Data were analyzed using SPSS-22. Results: Results of our study showed that all variables containing analgesia methods, labor duration of the first and second stages, and time were significant in these tests. In mixed model, heterogeneous first-order autoregressive, first-order autoregressive, heterogeneous Toeplitz and unstructured correlation structures were recognized as the best structures. Also, all variables were significant in these structures. Unstructured variance covariance matrix was recognized as the worst structure and labor duration of the first and second stages was not significant in this structure. Conclusions: This study showed that the Entonox inhalation has a significant effect on pain relief in primiparous and it is confirmed by all of the models.

  13. Performance of thallium bromide semiconductor detectors produced by repeated Bridgman method

    International Nuclear Information System (INIS)

    Santos, Robinson Alves dos; Costa, Fabio Eduardo da; Martins, Joao Francisco Trencher; Hamada, Margarida M.

    2009-01-01

    TlBr crystals have been grown by the Repeated Bridgman method from commercial TlBr materials and characterized to be used as radiation detectors. We have shown that the Repeated Bridgman is effective to reduce the concentration of impurities in TlBr. It was observed that detectors fabricated from higher purity crystal exhibit significant improvement in performance compared to those produced from low purity crystals. However, problems still exist in TlBr detectors, due to the low charge carrier collection efficiency, which is probably caused by additional impurities or defects incorporated during crystal growth and detector fabrication processes. (author)

  14. REPEATED MEASURES ANALYSIS OF CHANGES IN PHOTOSYNTHETIC EFFICIENCY IN SOUR CHERRY DURING WATER DEFICIT

    Directory of Open Access Journals (Sweden)

    Marija Viljevac

    2012-06-01

    Full Text Available The objective of this study was to investigate changes in photosynthetic efficiency applying repeated measures ANOVA using the photosynthetic performance index (PIABS of the JIP-test as a vitality parameter in seven genotypes of sour cherry (Prunus cerasus, L. during 10 days of continuous water deficit. Both univariate and multivariate ANOVA repeated measures revealed highly significant time effect (Days and its subsequent interactions with genotype and water deficit. However, the multivariate Pillai’s trace test detected the interaction Time × Genotype × Water deficit as not significant. According to the Tukey’s Studentized Range (HSD test, differences between the control and genotypes exposed to water stress became significant on the fourth day of the experiment, indicating that the plants on the average, began to lose their photosynthetic efficiency four days after being exposed to water shortage. It corroborates previous findings in other species that PIABS is very sensitive tool for detecting drought stress.

  15. Intelligence is in the eye of the beholder: investigating repeated IQ measurements in forensic psychiatry.

    Science.gov (United States)

    Habets, Petra; Jeandarme, Inge; Uzieblo, Kasia; Oei, Karel; Bogaerts, Stefan

    2015-05-01

    A stable assessment of cognition is of paramount importance for forensic psychiatric patients (FPP). The purpose of this study was to compare repeated measures of IQ scores in FPPs with and without intellectual disability. Repeated measurements of IQ scores in FPPs (n = 176) were collected. Differences between tests were computed, and each IQ score was categorized. Additionally, t-tests and regression analyses were performed. Differences of 10 points or more were found in 66% of the cases comparing WAIS-III with RAVEN scores. Fisher's exact test revealed differences between two WAIS-III scores and the WAIS categories. The WAIS-III did not predict other IQs (WAIS or RAVEN) in participants with intellectual disability. This study showed that stability or interchangeability of scores is lacking, especially in individuals with intellectual disability. Caution in interpreting IQ scores is therefore recommended, and the use of the unitary concept of IQ should be discouraged. © 2014 John Wiley & Sons Ltd.

  16. Analysis of oligonucleotide array experiments with repeated measures using mixed models

    Directory of Open Access Journals (Sweden)

    Getchell Thomas V

    2004-12-01

    Full Text Available Abstract Background Two or more factor mixed factorial experiments are becoming increasingly common in microarray data analysis. In this case study, the two factors are presence (Patients with Alzheimer's disease or absence (Control of the disease, and brain regions including olfactory bulb (OB or cerebellum (CER. In the design considered in this manuscript, OB and CER are repeated measurements from the same subject and, hence, are correlated. It is critical to identify sources of variability in the analysis of oligonucleotide array experiments with repeated measures and correlations among data points have to be considered. In addition, multiple testing problems are more complicated in experiments with multi-level treatments or treatment combinations. Results In this study we adopted a linear mixed model to analyze oligonucleotide array experiments with repeated measures. We first construct a generalized F test to select differentially expressed genes. The Benjamini and Hochberg (BH procedure of controlling false discovery rate (FDR at 5% was applied to the P values of the generalized F test. For those genes with significant generalized F test, we then categorize them based on whether the interaction terms were significant or not at the α-level (αnew = 0.0033 determined by the FDR procedure. Since simple effects may be examined for the genes with significant interaction effect, we adopt the protected Fisher's least significant difference test (LSD procedure at the level of αnew to control the family-wise error rate (FWER for each gene examined. Conclusions A linear mixed model is appropriate for analysis of oligonucleotide array experiments with repeated measures. We constructed a generalized F test to select differentially expressed genes, and then applied a specific sequence of tests to identify factorial effects. This sequence of tests applied was designed to control for gene based FWER.

  17. Reproducibility and repeatability of a new computerized software for sagittal spinopelvic and scoliosis curvature radiologic measurements: Keops(®).

    Science.gov (United States)

    Maillot, C; Ferrero, E; Fort, D; Heyberger, C; Le Huec, J-C

    2015-07-01

    The purpose of this study was to evaluate the inter- and intra-observer variability of the computerized radiologic measurements using Keops(®) and to determine the bias between the software and the standard paper measurement. Four individuals measured all frontal and sagittal variables on the 30 X-rays randomly selected on two occasions (test and retest conditions). The Bland-Altman plot was used to determine the degree of agreement between the measurement on paper X-ray and the measurement using Keops(®) for all reviewers and for the two measures; the intraclass correlation coefficient (ICC) was calculated for each pair of analyses to assess interobserver reproducibility among the four reviewers for the same patient using either paper X-ray or Keops(®) measurement and finally, concordance correlation coefficient (rc) was calculated to assess intraobserver repeatability among the same reviewer for one patient between the two measure using the same method (paper or Keops(®)). The mean difference calculated between the two methods was minimal at -0, 4° ± 3.41° [-7.1; 6.4] for frontal measurement and 0.1° ± 3.52° [-6.7; 6.8] for sagittal measurement. Keops(®) has a better interobserver reproducibility than paper measurement for determination of the sagittal pelvic parameter (ICC = 0.9960 vs. 0.9931; p = 0.0001). It has a better intraobserver repeatability than paper for determination of Cobbs angle (rc = 0.9872 vs. 0.9808; p rc = 0.9981 vs. 0.9953; p plane and that the use of this software can be recommended for clinical application. Diagnostic, level III.

  18. Automated methods of corrosion measurement

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Reeve, John Ch

    1997-01-01

    to revise assumptions regarding the basis of the method, which sometimes leads to the discovery of as-yet unnoticed phenomena. The present selection of automated methods for corrosion measurements is not motivated simply by the fact that a certain measurement can be performed automatically. Automation...... is applied to nearly all types of measurements today....

  19. Effect of repeated contact on adhesion measurements involving polydimethylsiloxane structural material

    International Nuclear Information System (INIS)

    Kroner, E; Arzt, E; Maboudian, R

    2009-01-01

    During the last few years several research groups have focused on the fabrication of artificial gecko inspired adhesives. For mimicking these structures, different polymers are used as structure material, such as polydimethylsiloxanes (PDMS), polyurethanes (PU), and polypropylene (PP). While these polymers can be structured easily and used for artificial adhesion systems, the effects of repeated adhesion testing have never been investigated closely. In this paper we report on the effect of repeated adhesion measurements on the commercially available poly(dimethylsiloxane) polymer kit Sylgard 184 (Dow Corning). We show that the adhesion force decreases as a function of contact cycles. The rate of change and the final value of adhesion are found to depend on the details of the PDMS synthesis and structuring.

  20. Context matters! sources of variability in weekend physical activity among families: a repeated measures study

    Directory of Open Access Journals (Sweden)

    Robert J. Noonan

    2017-04-01

    Full Text Available Abstract Background Family involvement is an essential component of effective physical activity (PA interventions in children. However, little is known about the PA levels and characteristics of PA among families. This study used a repeated measures design and multiple data sources to explore the variability and characteristics of weekend PA among families. Methods Families (including a ‘target’ child aged 9–11 years, their primary caregiver(s and siblings aged 6–8 years were recruited through primary schools in Liverpool, UK. Participants completed a paper-based PA diary and wore an ActiGraph GT9X accelerometer on their left wrist for up to 16 weekend days. ActiGraph.csv files were analysed using the R-package GGIR version 1.1–4. Mean minutes of moderate-to-vigorous PA (MVPA for each weekend of measurement were calculated using linear mixed models, and variance components were estimated for participant (inter-individual, weekend of measurement, and residual error (intra-individual. Intraclass correlation coefficients (ICC were calculated from the proportion of total variance accounted for by inter-individual sources, and used as a measure of reliability. Diary responses were summed to produce frequency counts. To offer contextual insight into weekend PA among family units, demographic, accelerometer, and diary data were combined to form two case studies representative of low and high active families. Results Twenty-five participants from 7 families participated, including 7 ‘target’ children (mean age 9.3 ± 1.1 years, 4 boys, 6 siblings (mean age 7.2 ± 0.7 years; 4 boys and 12 adults (7 mothers and 5 fathers. There was a high degree of variability in target children’s (ICC = 0.55, siblings (ICC = 0.38, and mothers’ MVPA (ICC = 0.58, but not in fathers’ MVPA (ICC = 0.83. Children’s weekend PA was mostly unstructured in nature and undertaken with friends, whereas a greater proportion of parents’ weekend

  1. Reliability and Repeatability of Cone Density Measurements in Patients With Stargardt Disease and RPGR-Associated Retinopathy

    Science.gov (United States)

    Tanna, Preena; Kasilian, Melissa; Strauss, Rupert; Tee, James; Kalitzeos, Angelos; Tarima, Sergey; Visotcky, Alexis; Dubra, Alfredo; Carroll, Joseph; Michaelides, Michel

    2017-01-01

    Purpose To assess reliability and repeatability of cone density measurements by using confocal and (nonconfocal) split-detector adaptive optics scanning light ophthalmoscopy (AOSLO) imaging. It will be determined whether cone density values are significantly different between modalities in Stargardt disease (STGD) and retinitis pigmentosa GTPase regulator (RPGR)–associated retinopathy. Methods Twelve patients with STGD (aged 9–52 years) and eight with RPGR-associated retinopathy (aged 11–31 years) were imaged using both confocal and split-detector AOSLO simultaneously. Four graders manually identified cone locations in each image that were used to calculate local densities. Each imaging modality was evaluated independently. The data set consisted of 1584 assessments of 99 STGD images (each image in two modalities and four graders who graded each image twice) and 928 RPGR assessments of 58 images (each image in two modalities and four graders who graded each image twice). Results For STGD assessments the reliability for confocal and split-detector AOSLO was 67.9% and 95.9%, respectively, and the repeatability was 71.2% and 97.3%, respectively. The differences in the measured cone density values between modalities were statistically significant for one grader. For RPGR assessments the reliability for confocal and split-detector AOSLO was 22.1% and 88.5%, respectively, and repeatability was 63.2% and 94.5%, respectively. The differences in cone density between modalities were statistically significant for all graders. Conclusions Split-detector AOSLO greatly improved the reliability and repeatability of cone density measurements in both disorders and will be valuable for natural history studies and clinical trials using AOSLO. However, it appears that these indices may be disease dependent, implying the need for similar investigations in other conditions. PMID:28738413

  2. The effect of repeated measurements and working memory on the most comfortable level in the ANL test

    DEFF Research Database (Denmark)

    Brännström, K Jonas; Olsen, Steen Østergaard; Holm, Lucas

    2014-01-01

    interleaved methodology during one session using a non-semantic version. Phonological (PWM) and visuospatial working memory (VSWM) was measured. STUDY SAMPLE: Thirty-two normal-hearing adults. RESULTS: Repeated measures ANOVA, intraclass correlations, and the coefficient of repeatability (CR) were used...

  3. Franchise Values in North American Professional Sports Leagues: Evidence from a Repeat Sales Method

    OpenAIRE

    Brad R. Humphreys; Yang Seung Lee

    2009-01-01

    The paper develops a quality adjusted professional sports franchise price index for North America based on a repeat sale method. This index reflects trends in the general price of sports franchises holding local market, facility, and team characteristics constant. The price index exhibits considerable volatility but no upward trend over time, unlike previous quality adjusted price indexes based on hedonic models in the literature. The lack of an upward trend in this quality adjusted price ind...

  4. Intra- and Intersession Repeatability of an Optical Quality and Intraocular Scattering Measurement System in Children.

    Directory of Open Access Journals (Sweden)

    Mi Tian

    Full Text Available To evaluate intra- and intersession repeatability of objective optical quality and intraocular scattering measurements with a double-pass system in children.Forty-two eyes of 42 children were included in the study. An optical quality analysis system (OQAS was used to measure optical quality parameters, including modulation transfer function cutoff frequency (MTFcutoff, Strehl ratio (SR, OQAS values (OV at 3 different contrasts and objective scatter index (OSI. Three measurement sessions with 10-min intervals were operated by the same technician, and in each session four consecutive measurements were obtained.Mean values for MTFcutoff, SR and OSI were 46.85 ± 7.45cpd, 0.27 ± 0.06 and 0.34 ± 0.22 respectively. 1 The intraclass correlation coefficients were ranged from 0.89 to 0.97 and coefficients of variation from 0.06 to 0.16 for all the parameters in the first session; the relative repeatability were 11.1% (MTFcutoff, 22.5% (SR, 10.9% (OV100%, 16.6% (OV2%, 22.4% (OV9% and 56.3% (OSI. Similar results were found in the second and third sessions. 2 Bland-Altman analysis showed that narrow 95% confidence intervals (compared between the first and second sessions ranged from -5.42 to 5.28 (MTFcutoff, -0.05 to 0.07 (SR, -0.18 to 0.18 (OV100%, -0.26 to 0.29 (OV20%, -0.33 to 0.39 (OV9% and -0.11 to 0.09 (OSI; the comparison between any two of the three sessions showed similar results.Measurements of optical quality and intraocular scattering in children by the double-pass system showed good intra- and intersession repeatability. Retinal image quality is high and intraocular scattering is low in children.

  5. Superficial Ultrasound Shear Wave Speed Measurements in Soft and Hard Elasticity Phantoms: Repeatability and Reproducibility Using Two Different Ultrasound Systems

    Science.gov (United States)

    Dillman, Jonathan R.; Chen, Shigao; Davenport, Matthew S.; Zhao, Heng; Urban, Matthew W.; Song, Pengfei; Watcharotone, Kuanwong; Carson, Paul L.

    2014-01-01

    Background There is a paucity of data available regarding the repeatability and reproducibility of superficial shear wave speed (SWS) measurements at imaging depths relevant to the pediatric population. Purpose To assess the repeatability and reproducibility of superficial shear wave speed (SWS) measurements acquired from elasticity phantoms at varying imaging depths using three different imaging methods, two different ultrasound systems, and multiple operators. Methods and Materials Soft and hard elasticity phantoms manufactured by Computerized Imaging Reference Systems, Inc. (Norfolk, VA) were utilized for our investigation. Institution #1 used an Acuson S3000 ultrasound system (Siemens Medical Solutions USA, Inc.) and three different shear wave imaging method/transducer combinations, while institution #2 used an Aixplorer ultrasound system (Supersonic Imagine) and two different transducers. Ten stiffness measurements were acquired from each phantom at three depths (1.0, 2.5, and 4.0 cm) by four operators at each institution. Student’s t-test was used to compare SWS measurements between imaging techniques, while SWS measurement agreement was assessed with two-way random effects single measure intra-class correlation coefficients and coefficients of variation. Mixed model regression analysis determined the effect of predictor variables on SWS measurements. Results For the soft phantom, the average of mean SWS measurements across the various imaging methods and depths was 0.84 ± 0.04 m/s (mean ± standard deviation) for the Acuson S3000 system and 0.90 ± 0.02 m/s for the Aixplorer system (p=0.003). For the hard phantom, the average of mean SWS measurements across the various imaging methods and depths was 2.14 ± 0.08 m/s for the Acuson S3000 system and 2.07 ± 0.03 m/s Aixplorer system (p>0.05). The coefficients of variation were low (0.5–6.8%), and inter-operator agreement was near-perfect (ICCs ≥0.99). Shear wave imaging method and imaging depth

  6. Validation of Repeated Endothelial Function Measurements Using EndoPAT in Stroke

    DEFF Research Database (Denmark)

    Hansen, Aina S; Butt, Jawad H; Holm-Yildiz, Sonja

    2017-01-01

    BACKGROUND: Decreased endothelial function (EF) may be a prognostic marker for stroke. Measuring pharmacological effects on EF may be of interest in the development of personalized medicine for stroke prevention. In this study, we assessed the reliability of repeated EF measurements using a pulse......%, mean age 35.85 ± 3.47 years) and 21 stroke patients (men 52%, mean age 66.38 ± 2.85 years, and mean NIHSS 4.09 ± 0.53) under standardized conditions. EF was measured as the reactive hyperemia index (RHI), logarithm of RHI (lnRHI), and Framingham RHI (fRHI). Measurements were separated by 1.5 and 24 h...

  7. Repeated dose titration versus age-based method in electroconvulsive therapy: a pilot study.

    Science.gov (United States)

    Aten, Jan Jaap; Oudega, Mardien; van Exel, Eric; Stek, Max L; van Waarde, Jeroen A

    2015-06-01

    In electroconvulsive therapy (ECT), a dose titration method (DTM) was suggested to be more individualized and therefore more accurate than formula-based dosing methods. A repeated DTM (every sixth session and dose adjustment accordingly) was compared to an age-based method (ABM) regarding treatment characteristics, clinical outcome, and cognitive functioning after ECT. Thirty-nine unipolar depressed patients dosed using repeated DTM and 40 matched patients treated with ABM were compared. Montgomery-Åsberg Depression Rating Scale (MADRS) and Mini-Mental State Examination (MMSE) were assessed at baseline and at the end of the index course, as well as the total number of ECT sessions. Both groups were similar regarding age, sex, psychotic features, mean baseline MADRS, and median baseline MMSE. At the end of the index course, the two methods showed equal outcome (mean end MADRS, 11.6 ± 8.3 in DTM and 9.5 ± 7.6 in ABM (P = 0.26); median end MMSE, 28 (25-29) and 28 (25-29.8), respectively (P = 0.81). However, the median number of all ECT sessions differed 16 (11-22) in DTM versus 12 (10-14.8) in ABM; P = 0.02]. Using regression analysis, dosing method and age were independently associated with the total number of ECT sessions, with less sessions needed in ABM (P = 0.02) and in older patients (P = 0.001). In this comparative cohort study, ABM and DTM showed equal outcome for depression and cognition. However, the median ECT course duration in repeated DTM appeared longer. Additionally, higher age was associated with shorter ECT courses regardless of the dosing method. Further prospective studies are needed to confirm these findings.

  8. Education for patients with chronic kidney disease in Taiwan: a prospective repeated measures study.

    Science.gov (United States)

    Yen, Miaofen; Huang, Jeng-Jong; Teng, Hsiu-Lan

    2008-11-01

    To investigate the physical, knowledge and quality of life outcomes of an educational intervention for patients with early stage chronic kidney disease. A comprehensive predialysis education care team can be effective in slowing the progression of chronic kidney disease. A single group repeated measures design was used to evaluate the effects of the intervention. Participants were recruited through health department community health screen data banks. A predialysis, team-delivered educational intervention covering renal function health care, dietary management of renal function and the effects of Chinese herb medication on renal function was designed and implemented. Data were collected at baseline, six and 12 months. Study outcomes included physical indicators, knowledge (renal function protection, use of Chinese herbs and renal function and diet) and quality of life. Data were analysed using repeated measure anova to test for change over time in outcome variables. Sixty-six persons participated in this study. The predialysis educational intervention showed significant differences at the three time points in overall knowledge scores, waist-hip ratio, body mass index and global health status. Knowledge measures increased at month 6 and decreased at month 12. The primary indicator of renal function, glomerular filtration rate, remained stable throughout the 12 months of follow-up, despite the relatively older mean age of study participants. A predialysis education care team can provide effective disease-specific knowledge and may help retard deterioration of renal function in persons with early-stage chronic kidney disease. The intervention dose may need to be repeated every six months to maintain knowledge effects. A predialysis educational program with disease-specific knowledge and information is feasible and may provide positive outcomes for patients. Topics on the uses of Chinese herbs should be included for people who are likely to use alternative therapies.

  9. Superficial ultrasound shear wave speed measurements in soft and hard elasticity phantoms: repeatability and reproducibility using two ultrasound systems.

    Science.gov (United States)

    Dillman, Jonathan R; Chen, Shigao; Davenport, Matthew S; Zhao, Heng; Urban, Matthew W; Song, Pengfei; Watcharotone, Kuanwong; Carson, Paul L

    2015-03-01

    There is a paucity of data available regarding the repeatability and reproducibility of superficial shear wave speed (SWS) measurements at imaging depths relevant to the pediatric population. To assess the repeatability and reproducibility of superficial shear wave speed measurements acquired from elasticity phantoms at varying imaging depths using three imaging methods, two US systems and multiple operators. Soft and hard elasticity phantoms manufactured by Computerized Imaging Reference Systems Inc. (Norfolk, VA) were utilized for our investigation. Institution No. 1 used an Acuson S3000 US system (Siemens Medical Solutions USA, Malvern, PA) and three shear wave imaging method/transducer combinations, while institution No. 2 used an Aixplorer US system (SuperSonic Imagine, Bothell, WA) and two different transducers. Ten stiffness measurements were acquired from each phantom at three depths (1.0 cm, 2.5 cm and 4.0 cm) by four operators at each institution. Student's t-test was used to compare SWS measurements between imaging techniques, while SWS measurement agreement was assessed with two-way random effects single-measure intra-class correlation coefficients (ICCs) and coefficients of variation. Mixed model regression analysis determined the effect of predictor variables on SWS measurements. For the soft phantom, the average of mean SWS measurements across the various imaging methods and depths was 0.84 ± 0.04 m/s (mean ± standard deviation) for the Acuson S3000 system and 0.90 ± 0.02 m/s for the Aixplorer system (P = 0.003). For the hard phantom, the average of mean SWS measurements across the various imaging methods and depths was 2.14 ± 0.08 m/s for the Acuson S3000 system and 2.07 ± 0.03 m/s Aixplorer system (P > 0.05). The coefficients of variation were low (0.5-6.8%), and interoperator agreement was near-perfect (ICCs ≥ 0.99). Shear wave imaging method and imaging depth significantly affected measured SWS (P

  10. Application of a repeat-measure biomarker measurement error model to 2 validation studies: examination of the effect of within-person variation in biomarker measurements.

    Science.gov (United States)

    Preis, Sarah Rosner; Spiegelman, Donna; Zhao, Barbara Bojuan; Moshfegh, Alanna; Baer, David J; Willett, Walter C

    2011-03-15

    Repeat-biomarker measurement error models accounting for systematic correlated within-person error can be used to estimate the correlation coefficient (ρ) and deattenuation factor (λ), used in measurement error correction. These models account for correlated errors in the food frequency questionnaire (FFQ) and the 24-hour diet recall and random within-person variation in the biomarkers. Failure to account for within-person variation in biomarkers can exaggerate correlated errors between FFQs and 24-hour diet recalls. For 2 validation studies, ρ and λ were calculated for total energy and protein density. In the Automated Multiple-Pass Method Validation Study (n=471), doubly labeled water (DLW) and urinary nitrogen (UN) were measured twice in 52 adults approximately 16 months apart (2002-2003), yielding intraclass correlation coefficients of 0.43 for energy (DLW) and 0.54 for protein density (UN/DLW). The deattenuated correlation coefficient for protein density was 0.51 for correlation between the FFQ and the 24-hour diet recall and 0.49 for correlation between the FFQ and the biomarker. Use of repeat-biomarker measurement error models resulted in a ρ of 0.42. These models were similarly applied to the Observing Protein and Energy Nutrition Study (1999-2000). In conclusion, within-person variation in biomarkers can be substantial, and to adequately assess the impact of correlated subject-specific error, this variation should be assessed in validation studies of FFQs. © The Author 2011. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved.

  11. Channel box dimension measuring method

    International Nuclear Information System (INIS)

    Oshima, Hirotake; Jo, Hiroto.

    1994-01-01

    The present invention provides a method for measuring the entire length of a channel box of a fuel assembly of a BWR type reactor. Namely, four sensors are used as one set that generate ultrasonic waves from oblique upper portion, oblique lower portion, upper portion and lower portion of the channel box respectively. The distances between the four sensors and each of the portions of the channel box are measured respectively for both of a reference member and a member to be measured. The entire length of the channel box is measured by calculating the measured values and the angles of the obliquely disposed sensors according to a predetermined formula. According to the method of the present invention, the inclination of the channel box to be measured can be corrected. In addition, accuracy of the measurement is improved and the measuring time is saved as well as the measuring device and operation can be simplified. (I.S.)

  12. Measuring Starlight Deflection during the 2017 Eclipse: Repeating the Experiment that made Einstein Famous

    Science.gov (United States)

    Bruns, Donald

    2016-05-01

    In 1919, astronomers performed an experiment during a solar eclipse, attempting to measure the deflection of stars near the sun, in order to verify Einstein's theory of general relativity. The experiment was very difficult and the results were marginal, but the success made Albert Einstein famous around the world. Astronomers last repeated the experiment in 1973, achieving an error of 11%. In 2017, using amateur equipment and modern technology, I plan to repeat the experiment and achieve a 1% error. The best available star catalog will be used for star positions. Corrections for optical distortion and atmospheric refraction are better than 0.01 arcsec. During totality, I expect 7 or 8 measurable stars down to magnitude 9.5, based on analysis of previous eclipse measurements taken by amateurs. Reference images, taken near the sun during totality, will be used for precise calibration. Preliminary test runs performed during twilight in April 2016 and April 2017 can accurately simulate the sky conditions during totality, providing an accurate estimate of the final uncertainty.

  13. Repeated absolute gravity measurements for monitoring slow intraplate vertical deformation in Western Europe

    Science.gov (United States)

    Van Camp, M. J.; de Viron, O.; Scherneck, H.; Hinzen, K. G.; Williams, S. D.; Lecocq, T.; Quinif, Y.; Camelbeeck, T.

    2011-12-01

    In continental plate interiors, ground surface movements are at the limit of the noise level and close to or below the accuracy of current geodetic techniques. Absolute gravity measurements are valuable to quantify slow vertical movements, as this instrument is drift free and, unlike GPS, independent of the terrestrial reference frame. Repeated absolute gravity (AG) measurements have been performed in Oostende (Belgian coastline) and at 8 stations along a southwest-northeast profile across the Belgian Ardennes and the Roer Valley Graben (Germany), in order to estimate the tectonic deformation in the area. The AG measurements, repeated once or twice a year, can resolve elusive gravity changes with a precision better than 3.7 nm/s2/yr (95% confidence interval) after 11 years, even in difficult conditions. After 8-15 years (depending on the station), we find that the gravity rates of change lie in the [-3.1, 8.1] nm/s2/yr interval and result from a combination of anthropogenic, climatic, tectonic, and Glacial Isostatic Adjustment (GIA) effects. After correcting for the GIA, the inferred gravity rates and consequently, the vertical land movements, reduce to zero within the uncertainty level at all stations except Jülich (due to man-induced subsidence) and Sohier (possibly, an artefact due to the shortness of the time series at that station).

  14. Repeated Geophysical Surface Measurements to Estimate the Dynamics of Underground Coalfires

    Science.gov (United States)

    Wuttke, M. W.; Kessels, W.; Han, J.; Halisch, M.; Rüter, H.; Lindner, H.

    2009-04-01

    in a range between -130 and 176 nT. The maxima are most likely caused by the conversion of pyrite and markasit into maghemite, hematite and magnetite. Therefore the identified patches with high magnetic anomalies should have a direct connection to the burning coal in firezone 18. The firezone in Wuda has been visited now for five, that in Queergou for two times. All the discussed geophysical measurements together allow an integrated interpretation. Each result can be related to the combustion process with a particular likelihood for the vertical projection to the combustion centre. Probability calculations with chosen weight factors for each observation method are discussed. A so called fireindex deduced from the repeated measurements reveals the dynamics of the coal fire.

  15. Predicting seed yield in perennial ryegrass using repeated canopy reflectance measurements and PLSR

    DEFF Research Database (Denmark)

    Gislum, René; Deleuran, Lise Christina; Boelt, Birte

    2009-01-01

    with first year seed crops using three sowing rates and three spring nitrogen (N) application rates. PLSR models were developed for each year and showed correlation coefficients of 0.71, 0.76, and 0.92, respectively. Regression coefficients showed in these experiments that the optimum time for canopy...... reflectance measurements was from approximately 600 cumulative growing degree-days (CGDD) to approximately 900 CGDD. This is the period just before and at heading of the seed crop. Furthermore, regression coefficients showed that information about N and water is important. The results support the development......Repeated canopy reflectance measurements together with partial least-squares regression (PLSR) were used to predict seed yield in perennial ryegrass (Lolium perenne L.). The measurements were performed during the spring and summer growing seasons of 2001 to 2003 in three field experiments...

  16. Welfare Risks of Repeated Application of On-Farm Killing Methods for Poultry

    Directory of Open Access Journals (Sweden)

    Jessica E. Martin

    2018-03-01

    Full Text Available Council Regulation (EC no. 1099/2009 on the protection of animals at the time of killing restricts the use of manual cervical dislocation in poultry on farms in the European Union (EU to birds weighing up to 3 kg and 70 birds per person per day. However, few studies have examined whether repeated application of manual cervical dislocation has welfare implications and whether these are dependent on individual operator skill or susceptibility to fatigue. We investigated the effects of repeated application (100 birds at a fixed killing rate of 1 bird per 2 min and multiple operators on two methods of killing of broilers, laying hens, and turkeys in commercial settings. We compared the efficacy and welfare impact of repeated application of cervical dislocation and a percussive killer (Cash Poultry Killer, CPK, using 12 male stockworkers on three farms (one farm per bird type. Both methods achieved over 96% kill success at the first attempt. The killing methods were equally effective for each bird type and there was no evidence of reduced performance with time and/or bird number. Both methods of killing caused a rapid loss of reflexes, indicating loss of brain function. There was more variation in reflex durations and post-mortem damage in birds killed by cervical dislocation than that found using CPK. High neck dislocation was associated with improved kill success and more rapid loss of reflexes. The CPK caused damage to multiple brain areas with little variation. Overall, the CPK was associated with faster abolition of reflexes, with fewer birds exhibiting them at all, suggestive of better welfare outcomes. However, technical difficulties with the CPK highlighted the advantages of cervical dislocation, which can be performed immediately with no equipment. At the killing rates tested, we did not find evidence to justify the current EU limit on the number of birds that one operator can kill on–farm by manual cervical dislocation.

  17. Characterization of the peripheral blood transcriptome in a repeated measures design using a panel of healthy individuals

    DEFF Research Database (Denmark)

    De Boever, Patrick; Wens, Britt; Forcheh, Anyiawung Chiara

    2014-01-01

    A repeated measures microarray design with 22 healthy, non-smoking volunteers (aging 32. ±. 5. years) was set up to study transcriptome profiles in whole blood samples. The results indicate that repeatable data can be obtained with high within-subject correlation. Probes that could discriminate b...

  18. Analyzing repeated measures data on individuals nested within groups: accounting for dynamic group effects.

    Science.gov (United States)

    Bauer, Daniel J; Gottfredson, Nisha C; Dean, Danielle; Zucker, Robert A

    2013-03-01

    Researchers commonly collect repeated measures on individuals nested within groups such as students within schools, patients within treatment groups, or siblings within families. Often, it is most appropriate to conceptualize such groups as dynamic entities, potentially undergoing stochastic structural and/or functional changes over time. For instance, as a student progresses through school, more senior students matriculate while more junior students enroll, administrators and teachers may turn over, and curricular changes may be introduced. What it means to be a student within that school may thus differ from 1 year to the next. This article demonstrates how to use multilevel linear models to recover time-varying group effects when analyzing repeated measures data on individuals nested within groups that evolve over time. Two examples are provided. The 1st example examines school effects on the science achievement trajectories of students, allowing for changes in school effects over time. The 2nd example concerns dynamic family effects on individual trajectories of externalizing behavior and depression. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  19. Tectonic, Climatic and Anthropogenic Vertical Land Movements in Western Europe by Repeated Absolute Gravity Measurements

    Science.gov (United States)

    van Camp, M. J.; de Viron, O.; Lecocq, T.; Hinzen, K. G.; Quinif, Y.; Williams, S. D.; Camelbeeck, T.

    2010-12-01

    In continental plate interiors, tectonic deformations are small and the associated ground surface movements remain close to or below the accuracy of current geodetic techniques, and at the limit of the noise level. An absolute gravimeter is an appropriate tool to quantify slow vertical movements, as this instrument, based on length and time standards, is drift free and does not depend on any terrestrial reference frame. Repeated absolute gravity (AG) measurements have been performed in Oostende (Belgian coastline) and at 8 stations along a southwest-northeast profile across the Belgian Ardennes and the Roer Valley Graben (Germany), in order to estimate the tectonic deformations in the area. After 7-13 years (depending on the station), we find evidence that the movements are no larger than a few millimeter per year and result from a combination of anthropogenic, climatic, tectonic, and Glacial Isostatic Adjustment (GIA) effects. This demonstrates the importance of precisely modeling the GIA effects in order to investigate intraplate tectonic deformations at the sub-millimeter level. This study also shows that AG measurements, repeated once or twice a year, can resolve vertical velocities at the 1.0 mm/yr level after 10 years, even in difficult conditions, provided that the gravimeter is carefully maintained.

  20. ±25ppm repeatable measurement of trapezoidal pulses with 5MHz bandwidth

    CERN Document Server

    AUTHOR|(SzGeCERN)712364; Arpaia, Pasquale; Cerqueira Bastos, Miguel; Martino, Michele

    2015-01-01

    High-quality measurements of pulses are nowadays widely used in fields such as radars, pulsed lasers, electromagnetic pulse generators, and particle accelerators. Whilst literature is mainly focused on fast systems for nanosecond regime with relaxed metrological requirements, in this paper, the high-performance measurement of slower pulses in microsecond regime is faced. In particular, the experimental proof demonstration for a 15 MS/s,_25 ppm repeatable acquisition system to characterize the flat-top of 3 ms rise-time trapezoidal pulses is given. The system exploits a 5MHz bandwidth circuit for analogue signal processing based on the concept of flat-top removal. The requirements, as well as the conceptual and physical designs are illustrated. Simulation results aimed at assessing the circuit performance are also presented. Finally, an experimental case study on the characterization of a pulsed power supply for the klystrons modulators of the Compact Linear Collider (CLIC) under study at CERN is reported. In ...

  1. Detection-Discrimination Method for Multiple Repeater False Targets Based on Radar Polarization Echoes

    Directory of Open Access Journals (Sweden)

    Z. W. ZONG

    2014-04-01

    Full Text Available Multiple repeat false targets (RFTs, created by the digital radio frequency memory (DRFM system of jammer, are widely used in practical to effectively exhaust the limited tracking and discrimination resource of defence radar. In this paper, common characteristic of radar polarization echoes of multiple RFTs is used for target recognition. Based on the echoes from two receiving polarization channels, the instantaneous polarization radio (IPR is defined and its variance is derived by employing Taylor series expansion. A detection-discrimination method is designed based on probability grids. By using the data from microwave anechoic chamber, the detection threshold of the method is confirmed. Theoretical analysis and simulations indicate that the method is valid and feasible. Furthermore, the estimation performance of IPRs of RFTs due to the influence of signal noise ratio (SNR is also covered.

  2. Spectrometric kidney depth measurement method

    International Nuclear Information System (INIS)

    George, P.; Soussaline, F.; Raynaud, C.

    1976-01-01

    The method proposed uses the single posterior surface measurement of the kidney radioactivity distribution. The ratio C/P of the number of scattered photons to the number of primary photons, which is a function of the tissue depth penetrated, is calculated for a given region. The parameters on which the C/P value depends are determined from studies on phantoms. On the basis of these results the kidney depth was measured on a series of 13 patients and a correlation was established between the value thus calculated and that obtained by the profile method. The reproducibility of the method is satisfactory [fr

  3. Methods for Human Dehydration Measurement

    Science.gov (United States)

    Trenz, Florian; Weigel, Robert; Hagelauer, Amelie

    2018-03-01

    The aim of this article is to give a broad overview of current methods for the identification and quantification of the human dehydration level. Starting off from most common clinical setups, including vital parameters and general patients' appearance, more quantifiable results from chemical laboratory and electromagnetic measurement methods will be reviewed. Different analysis methods throughout the electromagnetic spectrum, ranging from direct current (DC) conductivity measurements up to neutron activation analysis (NAA), are discussed on the base of published results. Finally, promising technologies, which allow for an integration of a dehydration assessment system in a compact and portable way, will be spotted.

  4. A Modified Jonckheere Test Statistic for Ordered Alternatives in Repeated Measures Design

    Directory of Open Access Journals (Sweden)

    Hatice Tül Kübra AKDUR

    2016-09-01

    Full Text Available In this article, a new test based on Jonckheere test [1] for  randomized blocks which have dependent observations within block is presented. A weighted sum for each block statistic rather than the unweighted sum proposed by Jonckheereis included. For Jonckheere type statistics, the main assumption is independency of observations within block. In the case of repeated measures design, the assumption of independence is violated. The weighted Jonckheere type statistic for the situation of dependence for different variance-covariance structure and the situation based on ordered alternative hypothesis structure of each block on the design is used. Also, the proposed statistic is compared to the existing test based on Jonckheere in terms of type I error rates by performing Monte Carlo simulation. For the strong correlations, circular bootstrap version of the proposed Jonckheere test provides lower rates of type I error.

  5. Repeatability of swept-source optical coherence tomography retinal and choroidal thickness measurements in neovascular age-related macular degeneration

    DEFF Research Database (Denmark)

    Hanumunthadu, Daren; Ilginis, Tomas; Restori, Marie

    2017-01-01

    BACKGROUND: The aim was to determine the intrasession repeatability of swept-source optical coherence tomography (SS-OCT)-derived retinal and choroidal thickness measurements in eyes with neovascular age-related macular degeneration (nAMD). METHODS: A prospective study consisting of patients...... with active nAMD enrolled in the Distance of Choroid Study at Moorfields Eye Hospital, London. Patients underwent three 12×9 mm macular raster scans using the deep range imaging (DRI) OCT-1 SS-OCT (Topcon) device in a single imaging session. Retinal and choroidal thicknesses were calculated for the ETDRS...... macular subfields. Repeatability was calculated according to methods described by Bland and Altman. RESULTS: 39 eyes of 39 patients with nAMD were included with a mean (±SD) age of 73.9 (±7.2) years. The mean (±SD) retinal thickness of the central macular subfield was 225.7 μm (±12.4 μm...

  6. Facile fabrication of controllable zinc oxide nanorod clusters on polyacrylonitrile nanofibers via repeatedly alternating immersion method

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ying; Li, Xia; Yu, Hou-Yong, E-mail: phdyu@zstu.edu.cn [Zhejiang Sci-Tech University, The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textiles (China); Hu, Guo-Liang; Yao, Ju-Ming, E-mail: yaoj@zstu.edu.cn [Zhejiang Sci-Tech University, National Engineering Lab for Textile Fiber Materials and Processing Technology (China)

    2016-12-15

    Polyacrylonitrile/zinc oxide (PAN/ZnO) composite nanofiber membranes with different ZnO morphologies were fabricated by repeatedly alternating hot–cold immersion and single alternating hot–cold immersion methods. The influence of the PAN/ZnCl{sub 2} ratio and different immersion methods on the morphology, microstructure, and properties of the nanofiber membranes was investigated by using field-emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis, thermogravimetric analysis (TGA), and ultraviolet–visible (UV–Vis) spectroscopy. A possible mechanism for different morphologies of PAN/ZnO nanofiber membranes with different PAN/ZnCl{sub 2} ratio through different immersion processes was presented, and well-dispersed ZnO nanorod clusters with smallest average dimeter of 115 nm and hexagonal wurtzite structure were successfully anchored onto the PAN nanofiber surface for R-7/1 nanofiber membrane. Compared to S-5/1 prepared by single alternating hot–cold immersion method, the PAN/ZnO nanofiber membrane fabricated by repeatedly alternating hot–cold immersion method (especially for R-7/1) showed improved thermal stability and high photocatalytic activity for methylene blue (MB). Compared to S-5/1, decomposition temperature at 5% weight loss (T{sub 5%}) was increased by 43 °C from 282 to 325 °C for R-7/1; meanwhile, R-7/1 showed higher photocatalytic degradation ratio of approximately 100% (after UV light irradiation for 8 h) than 65% for S-5/1 even after irradiation for 14 h. Moreover, the degradation efficiency of R-7/1 with good reuse stability remained above 94% after 3 cycles.

  7. Development of a Method to Compensate for Signal Quality Variations in Repeated Auditory Event-Related Potential Recordings

    Science.gov (United States)

    Paukkunen, Antti K. O.; Leminen, Miika M.; Sepponen, Raimo

    2010-01-01

    Reliable measurements are mandatory in clinically relevant auditory event-related potential (AERP)-based tools and applications. The comparability of the results gets worse as a result of variations in the remaining measurement error. A potential method is studied that allows optimization of the length of the recording session according to the concurrent quality of the recorded data. In this way, the sufficiency of the trials can be better guaranteed, which enables control of the remaining measurement error. The suggested method is based on monitoring the signal-to-noise ratio (SNR) and remaining measurement error which are compared to predefined threshold values. The SNR test is well defined, but the criterion for the measurement error test still requires further empirical testing in practice. According to the results, the reproducibility of average AERPs in repeated experiments is improved in comparison to a case where the number of recorded trials is constant. The test-retest reliability is not significantly changed on average but the between-subject variation in the value is reduced by 33–35%. The optimization of the number of trials also prevents excessive recordings which might be of practical interest especially in the clinical context. The efficiency of the method may be further increased by implementing online tools that improve data consistency. PMID:20407635

  8. A novel multiple locus variable number of tandem repeat (VNTR) analysis (MLVA) method for Propionibacterium acnes.

    Science.gov (United States)

    Hauck, Yolande; Soler, Charles; Gérôme, Patrick; Vong, Rithy; Macnab, Christine; Appere, Géraldine; Vergnaud, Gilles; Pourcel, Christine

    2015-07-01

    Propionibacterium acnes plays a central role in the pathogenesis of acne and is responsible for severe opportunistic infections. Numerous typing schemes have been developed that allow the identification of phylotypes, but they are often insufficient to differentiate subtypes. To better understand the genetic diversity of this species and to perform epidemiological analyses, high throughput discriminant genotyping techniques are needed. Here we describe the development of a multiple locus variable number of tandem repeats (VNTR) analysis (MLVA) method. Thirteen VNTRs were identified in the genome of P. acnes and were used to genotype a collection of clinical isolates. In addition, publically available sequencing data for 102 genomes were analyzed in silico, providing an MLVA genotype. The clustering of MLVA data was in perfect congruence with whole genome based clustering. Analysis of the clustered regularly interspaced short palindromic repeat (CRISPR) element uncovered new spacers, a supplementary source of genotypic information. The present MLVA13 scheme and associated internet database represents a first line genotyping assay to investigate large number of isolates. Particular strains may then be submitted to full genome sequencing in order to better analyze their pathogenic potential. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Repeated assessment of orthotopic glioma pO2 by multi-site EPR oximetry: A technique with the potential to guide therapeutic optimization by repeated measurements of oxygen

    Science.gov (United States)

    Khan, Nadeem; Mupparaju, Sriram; Hou, Huagang; Williams, Benjamin B.; Swartz, Harold

    2011-01-01

    Tumor hypoxia plays a vital role in therapeutic resistance. Consequently, measurements of tumor pO2 could be used to optimize the outcome of oxygen-dependent therapies, such as, chemoradiation. However, the potential optimizations are restricted by the lack of methods to repeatedly and quantitatively assess tumor pO2 during therapies, particularly in gliomas. We describe the procedures for repeated measurements of orthotopic glioma pO2 by multi-site electron paramagnetic resonance (EPR) oximetry. This oximetry approach provides simultaneous measurements of pO2 at more than one site in the glioma and contralateral cerebral tissue. The pO2 of intracerebral 9L, C6, F98 and U251 tumors, as well as contralateral brain, were measured repeatedly for five consecutive days. The 9L glioma was well oxygenated with pO2 of 27 - 36 mm Hg, while C6, F98 and U251 glioma were hypoxic with pO2 of 7 - 12 mm Hg. The potential of multi-site EPR oximetry to assess temporal changes in tissue pO2 was investigated in rats breathing 100% O2. A significant increase in F98 tumor and contralateral brain pO2 was observed on day 1 and day 2, however, glioma oxygenation declined on subsequent days. In conclusion, EPR oximetry provides the capability to repeatedly assess temporal changes in orthotopic glioma pO2. This information could be used to test and optimize the methods being developed to modulate tumor hypoxia. Furthermore, EPR oximetry could be potentially used to enhance the outcome of chemoradiation by scheduling treatments at times of increase in glioma pO2. PMID:22079559

  10. Microcomputer-based tests for repeated-measures: Metric properties and predictive validities

    Science.gov (United States)

    Kennedy, Robert S.; Baltzley, Dennis R.; Dunlap, William P.; Wilkes, Robert L.; Kuntz, Lois-Ann

    1989-01-01

    A menu of psychomotor and mental acuity tests were refined. Field applications of such a battery are, for example, a study of the effects of toxic agents or exotic environments on performance readiness, or the determination of fitness for duty. The key requirement of these tasks is that they be suitable for repeated-measures applications, and so questions of stability and reliability are a continuing, central focus of this work. After the initial (practice) session, seven replications of 14 microcomputer-based performance tests (32 measures) were completed by 37 subjects. Each test in the battery had previously been shown to stabilize in less than five 90-second administrations and to possess retest reliabilities greater than r = 0.707 for three minutes of testing. However, all the tests had never been administered together as a battery and they had never been self-administered. In order to provide predictive validity for intelligence measurement, the Wechsler Adult Intelligence Scale-Revised and the Wonderlic Personnel Test were obtained on the same subjects.

  11. A rational repeating template method for synthesis of 2D hexagonally ordered mesoporous precious metals.

    Science.gov (United States)

    Takai, Azusa; Doi, Yoji; Yamauchi, Yusuke; Kuroda, Kazuyuki

    2011-03-01

    A repeating template method is presented for the synthesis of mesoporous metals with 2D hexagonal mesostructures. First, a silica replica (i.e., silica nanorods arranged periodically) is prepared by using 2D hexagonally ordered mesoporous carbon as the template. After that, the obtained silica replica is used as the second template for the preparation of mesoporous ruthenium. After the ruthenium species are introduced into the silica replica, the ruthenium species are then reduced by a vapor-infiltration method by using the reducing agent dimethylamine borane. After the ruthenium deposition, the silica is chemically removed. Analysis by transmission and scanning electron microscopies, a nitrogen-adsorption-desorption isotherm, and small-angle X-ray scattering revealed that the mesoporous ruthenium had a 2D hexagonal mesostructure, although the mesostructural ordering is decreased compared to that of the original mesoporous carbon template. This method is widely applicable to other metal systems. By changing the metal species introduced into the silica replica, several mesoporous metals (palladium and platinum) can be synthesized. Ordered mesoporous ruthenium and palladium, which are not easily attainable by the soft-templating methods, can be prepared. This study has overcome the composition variation limitations of the soft-templating method. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Radiation protection, measurements and methods

    International Nuclear Information System (INIS)

    1983-06-01

    The introductory lectures discuss subjects such as radiation protection principles and appropriate measuring techniques; methods, quantities and units in radiation protection measurement; technical equipment; national and international radiation protection standards. The papers presented at the various sessions deal with: Dosimetry of external radiation (27 papers); Working environment monitoring and emission monitoring (21 contributions); Environmental monitoring (19 papers); Incorporation monitoring (9 papers); Detection limits (4 papers); Non-ionizing radiation, measurement of body dose and biological dosimetry (10 papers). All 94 contributions (lectures, compacts and posters) are retrievable as separate records. (HP) [de

  13. Repeated Blood Pressure Measurements in Childhood in Prediction of Hypertension in Adulthood.

    Science.gov (United States)

    Oikonen, Mervi; Nuotio, Joel; Magnussen, Costan G; Viikari, Jorma S A; Taittonen, Leena; Laitinen, Tomi; Hutri-Kähönen, Nina; Jokinen, Eero; Jula, Antti; Cheung, Michael; Sabin, Matthew A; Daniels, Stephen R; Raitakari, Olli T; Juonala, Markus

    2016-01-01

    Hypertension may be predicted from childhood risk factors. Repeated observations of abnormal blood pressure in childhood may enhance prediction of hypertension and subclinical atherosclerosis in adulthood compared with a single observation. Participants (1927, 54% women) from the Cardiovascular Risk in Young Finns Study had systolic and diastolic blood pressure measurements performed when aged 3 to 24 years. Childhood/youth abnormal blood pressure was defined as above 90th or 95th percentile. After a 21- to 31-year follow-up, at the age of 30 to 45 years, hypertension (>140/90 mm Hg or antihypertensive medication) prevalence was found to be 19%. Carotid intima-media thickness was examined, and high-risk intima-media was defined as intima-media thickness >90th percentile or carotid plaques. Prediction of adulthood hypertension and high-risk intima-media was compared between one observation of abnormal blood pressure in childhood/youth and multiple observations by improved Pearson correlation coefficients and area under the receiver operating curve. When compared with a single measurement, 2 childhood/youth observations improved the correlation for adult systolic (r=0.44 versus 0.35, Phypertension in adulthood (0.63 for 2 versus 0.60 for 1 observation, P=0.003). When compared with 2 measurements, third observation did not provide any significant improvement for correlation or prediction (P always >0.05). A higher number of childhood/youth observations of abnormal blood pressure did not enhance prediction of adult high-risk intima-media thickness. Compared with a single measurement, the prediction of adult hypertension was enhanced by 2 observations of abnormal blood pressure in childhood/youth. © 2015 American Heart Association, Inc.

  14. Measurement of repeat effects in Chicago’s criminal social network

    Directory of Open Access Journals (Sweden)

    Paul Kump

    2016-07-01

    Full Text Available The “near-repeat” effect is a well-known criminological phenomenon in which the occurrence of a crime incident gives rise to a temporary elevation of crime risk within close physical proximity to an initial incident. Adopting a social network perspective, we instead define a near repeat in terms of geodesic distance within a criminal social network, rather than spatial distance. Specifically, we report a statistical analysis of repeat effects in arrest data for Chicago during the years 2003–2012. We divide the arrest data into two sets (violent crimes and other crimes and, for each set, we compare the distributions of time intervals between repeat incidents to theoretical distributions in which repeat incidents occur only by chance. We first consider the case of the same arrestee participating in repeat incidents (“exact repeats” and then extend the analysis to evaluate repeat risks of those arrestees near one another in the social network. We observe repeat effects that diminish as a function of geodesic distance and time interval, and we estimate typical time scales for repeat crimes in Chicago.

  15. Toward a simple, repeatable, non-destructive approach to measuring stable-isotope ratios of water within tree stems

    Science.gov (United States)

    Raulerson, S.; Volkmann, T.; Pangle, L. A.

    2017-12-01

    Traditional methodologies for measuring ratios of stable isotopes within the xylem water of trees involve destructive coring of the stem. A recent approach involves permanently installed probes within the stem, and an on-site assembly of pumps, switching valves, gas lines, and climate-controlled structure for field deployment of a laser spectrometer. The former method limits the possible temporal resolution of sampling, and sample size, while the latter may not be feasible for many research groups. We present results from initial laboratory efforts towards developing a non-destructive, temporally-resolved technique for measuring stable isotope ratios within the xylem flow of trees. Researchers have used direct liquid-vapor equilibration as a method to measure isotope ratios of the water in soil pores. Typically, this is done by placing soil samples in a fixed container, and allowing the liquid water within the soil to come into isotopic equilibrium with the headspace of the container. Water can also be removed via cryogenic distillation or azeotropic distillation, with the resulting liquid tested for isotope ratios. Alternatively, the isotope ratios of the water vapor can be directly measured using a laser-based water vapor isotope analyzer. Well-established fractionation factors and the isotope ratios in the vapor phase are then used to calculate the isotope ratios in the liquid phase. We propose a setup which would install a single, removable chamber onto a tree, where vapor samples could non-destructively and repeatedly be taken. These vapor samples will be injected into a laser-based isotope analyzer by a recirculating gas conveyance system. A major part of what is presented here is in the procedure of taking vapor samples at 100% relative humidity, appropriately diluting them with completely dry N2 calibration gas, and injecting them into the gas conveyance system without inducing fractionation in the process. This methodology will be helpful in making

  16. [Comparision of Different Methods of Area Measurement in Irregular Scar].

    Science.gov (United States)

    Ran, D; Li, W J; Sun, Q G; Li, J Q; Xia, Q

    2016-10-01

    To determine a measurement standard of irregular scar area by comparing the advantages and disadvantages of different measurement methods in measuring same irregular scar area. Irregular scar area was scanned by digital scanning and measured by coordinate reading method, AutoCAD pixel method, Photoshop lasso pixel method, Photoshop magic bar filled pixel method and Foxit PDF reading software, and some aspects of these methods such as measurement time, repeatability, whether could be recorded and whether could be traced were compared and analyzed. There was no significant difference in the scar areas by the measurement methods above. However, there was statistical difference in the measurement time and repeatability by one or multi performers and only Foxit PDF reading software could be traced back. The methods above can be used for measuring scar area, but each one has its advantages and disadvantages. It is necessary to develop new measurement software for forensic identification. Copyright© by the Editorial Department of Journal of Forensic Medicine

  17. Comparison of electric field exposure measurement methods under power lines

    International Nuclear Information System (INIS)

    Korpinen, L.; Kuisti, H.; Tarao, H.; Paeaekkoenen, R.; Elovaara, J.

    2014-01-01

    The object of the study was to investigate extremely low frequency (ELF) electric field exposure measurement methods under power lines. The authors compared two different methods under power lines: in Method A, the sensor was placed on a tripod; and Method B required the measurer to hold the meter horizontally so that the distance from him/her was at least 1.5 m. The study includes 20 measurements in three places under 400 kV power lines. The authors used two commercial three-axis meters, EFA-3 and EFA-300. In statistical analyses, they did not find significant differences between Methods A and B. However, in the future, it is important to take into account that measurement methods can, in some cases, influence ELF electric field measurement results, and it is important to report the methods used so that it is possible to repeat the measurements. (authors)

  18. Statistical methods for conducting agreement (comparison of clinical tests) and precision (repeatability or reproducibility) studies in optometry and ophthalmology.

    Science.gov (United States)

    McAlinden, Colm; Khadka, Jyoti; Pesudovs, Konrad

    2011-07-01

    The ever-expanding choice of ocular metrology and imaging equipment has driven research into the validity of their measurements. Consequently, studies of the agreement between two instruments or clinical tests have proliferated in the ophthalmic literature. It is important that researchers apply the appropriate statistical tests in agreement studies. Correlation coefficients are hazardous and should be avoided. The 'limits of agreement' method originally proposed by Altman and Bland in 1983 is the statistical procedure of choice. Its step-by-step use and practical considerations in relation to optometry and ophthalmology are detailed in addition to sample size considerations and statistical approaches to precision (repeatability or reproducibility) estimates. Ophthalmic & Physiological Optics © 2011 The College of Optometrists.

  19. Developing the Pieta House Suicide Intervention Model: a quasi-experimental, repeated measures design.

    Science.gov (United States)

    Surgenor, Paul Wg; Freeman, Joan; O'Connor, Cindy

    2015-01-01

    While most crisis intervention models adhere to a generalised theoretical framework, the lack of clarity around how these should be enacted has resulted in a proliferation of models, most of which have little to no empirical support. The primary aim of this research was to propose a suicide intervention model that would resolve the client's suicidal crisis by decreasing their suicidal ideation and improve their outlook through enhancing a range of protective factors. The secondary aim was to assess the impact of this model on negative and positive outlook. A quasi-experimental, pre-test post-test repeated measures design was employed. A questionnaire assessing self-esteem, depression, and positive and negative suicidal ideation was administered to the same participants pre- and post- therapy facilitating paired responses. Multiple analysis of variance and paired-samples t-tests were conducted to establish whether therapy using the PH-SIM had a significant effect on the clients' negative and positive outlook. Analyses revealed a statistically significant effect of therapy for depression, negative suicidal ideation, self-esteem, and positive suicidal ideation. Negative outlook was significantly lower after therapy and positive outlook significantly higher. The decreased negative outlook and increased positive outlook following therapy provide some support for the proposed model in fulfilling its role, though additional research is required to establish the precise role of the intervention model in achieving this.

  20. Analyzing repeated data collected by mobile phones and frequent text messages. An example of Low back pain measured weekly for 18 weeks

    DEFF Research Database (Denmark)

    Axén, Iben; Bodin, Lennart; Kongsted, Alice

    2012-01-01

    to recovery? This question was answered using survival analysis, illustrated in Kaplan-Meier curves, Proportional Hazard regression analyses and spline regression analyses. 4: How is the repeatedly measured data associated with baseline (predictor) variables? This question was answered using generalized...... involves some challenges. Vital issues to consider are the within-subject correlation, the between measurement occasion correlation and the presence of missing values. The overall aim of this commentary is to describe different methods of analyzing repeated data. It is meant to give an overview...... for the clinical researcher in order for complex outcome measures to be interpreted in a clinically meaningful way. METHODS: A model data set was formed using data from two clinical studies, where patients with low back pain were followed with weekly text messages for 18 weeks. Different research questions...

  1. Psychosocial outcomes of Hong Kong Chinese diagnosed with acute coronary syndromes: a prospective repeated measures study.

    Science.gov (United States)

    Chan, Dominic S K; Chau, Janita P C; Chang, Anne M

    2007-08-01

    Western studies have suggested that emotional stress and distress impacted on the morbidity and mortality in people following acute coronary events. Symptoms of anxiety and depression have been associated with re-infarction and death, prolonged recovery and disability and depression may precipitate the client's low self-esteem. This study examined perceived anxiety, depression and self-esteem of Hong Kong Chinese clients diagnosed with acute coronary syndrome (ACS) over a 6-month period following hospital admission. To examine: A prospective, repeated measures design with measures taken on two occasions over a 6-month period; (1) within the 1st week of hospital admission following the onset of ACS and (2) at 6 months follow up. Convenient sample of 182 voluntary consented clients admitted with ACS to a major public hospital in Hong Kong who could communicate in Chinese, complete questionnaires, cognitive intact, and were haemodynamically stable and free from acute chest pain at the time of interview. Baseline data were obtained within 1 week after hospital admission. The follow-up data was collected 6 months after hospital discharge. The Chinese version of the Hospital Anxiety and Depression Scale (HADS), State Self-esteem Scale (SSES), and Rosenberg's Self-Esteem Scale (RSES) were used to assess anxiety and depression, state self-esteem, and trait self-esteem, respectively. Findings suggested gender differences in clients' perception in anxiety, depression and self-esteem. Improvements in clients' perception of these variables were evident over the 6-month period following their acute coronary events. The study confirmed the western notion that psychosocial problems are common among coronary clients and this also applies to Hong Kong Chinese diagnosed with ACS. Further studies to explore effective interventions to address these psychosocial issues are recommended.

  2. Effect of hip braces on brake response time: Repeated measures designed study.

    Science.gov (United States)

    Dammerer, Dietmar; Waidmann, Cornelia; Huber, Dennis G; Krismer, Martin; Haid, Christian; Liebensteiner, Michael C

    2017-08-01

    The question whether or not a patient with a hip brace should drive a car is of obvious importance because the advice given to patients to resume driving is often anecdotal as few scientific data are available on this specific subject. To assess driving ability (brake response time) with commonly used hip braces. Repeated measures design. Brake response time was assessed under six conditions: (1) without a brace (control), (2) with a typical postoperative hip brace with adjustable range of motion and the settings: unrestricted, (3) flexion limited to 70°, (4) extension blocked at 20° hip flexion, (5) both flexion and extension limited (20°/70°) and (6) an elastic hip bandage. Brake response time was assessed using a custom-made driving simulator as used in previous studies. The participants were a convenience sample of able-bodied participants. A total of 70 participants (35 women and 35 men) participated in our study. Mean age was 31.1 (standard deviation: 10.6; range: 21.7-66.4) years. A significant within-subject effect for brake response time was found ( p = 0.009), but subsequent post hoc analyses revealed no significant differences between control and the other settings. Based on our findings, it does not seem mandatory to recommend driving abstinence for patients wearing a hip orthosis. We suggest that our results be interpreted with caution, because (1) an underlying pathological hip condition needs to be considered, (2) the ability to drive a car safely is multifactorial and brake response time is only one component thereof and (3) brake response time measurements were performed only with healthy participants. Clinical relevance Hip braces are used in the context of joint-preserving and prosthetic surgery of the hip. Therefore, clinicians are confronted with the question whether to allow driving a car with the respective hip brace or not. Our data suggest that hip braces do not impair brake response time.

  3. A repeated measures experiment of green exercise to improve self-esteem in UK school children.

    Directory of Open Access Journals (Sweden)

    Katharine Reed

    Full Text Available Exercising in natural, green environments creates greater improvements in adult's self-esteem than exercise undertaken in urban or indoor settings. No comparable data are available for children. The aim of this study was to determine whether so called 'green exercise' affected changes in self-esteem; enjoyment and perceived exertion in children differently to urban exercise. We assessed cardiorespiratory fitness (20 m shuttle-run and self-reported physical activity (PAQ-A in 11 and 12 year olds (n = 75. Each pupil completed two 1.5 mile timed runs, one in an urban and another in a rural environment. Trials were completed one week apart during scheduled physical education lessons allocated using a repeated measures design. Self-esteem was measured before and after each trial, ratings of perceived exertion (RPE and enjoyment were assessed after completing each trial. We found a significant main effect (F (1,74, = 12.2, p<0.001, for the increase in self-esteem following exercise but there was no condition by exercise interaction (F (1,74, = 0.13, p = 0.72. There were no significant differences in perceived exertion or enjoyment between conditions. There was a negative correlation (r = -0.26, p = 0.04 between habitual physical activity and RPE during the control condition, which was not evident in the green exercise condition (r = -0.07, p = 0.55. Contrary to previous studies in adults, green exercise did not produce significantly greater increases in self-esteem than the urban exercise condition. Green exercise was enjoyed more equally by children with differing levels of habitual physical activity and has the potential to engage less active children in exercise.

  4. A repeated measures experiment of green exercise to improve self-esteem in UK school children.

    Science.gov (United States)

    Reed, Katharine; Wood, Carly; Barton, Jo; Pretty, Jules N; Cohen, Daniel; Sandercock, Gavin R H

    2013-01-01

    Exercising in natural, green environments creates greater improvements in adult's self-esteem than exercise undertaken in urban or indoor settings. No comparable data are available for children. The aim of this study was to determine whether so called 'green exercise' affected changes in self-esteem; enjoyment and perceived exertion in children differently to urban exercise. We assessed cardiorespiratory fitness (20 m shuttle-run) and self-reported physical activity (PAQ-A) in 11 and 12 year olds (n = 75). Each pupil completed two 1.5 mile timed runs, one in an urban and another in a rural environment. Trials were completed one week apart during scheduled physical education lessons allocated using a repeated measures design. Self-esteem was measured before and after each trial, ratings of perceived exertion (RPE) and enjoyment were assessed after completing each trial. We found a significant main effect (F (1,74), = 12.2, pself-esteem following exercise but there was no condition by exercise interaction (F (1,74), = 0.13, p = 0.72). There were no significant differences in perceived exertion or enjoyment between conditions. There was a negative correlation (r = -0.26, p = 0.04) between habitual physical activity and RPE during the control condition, which was not evident in the green exercise condition (r = -0.07, p = 0.55). Contrary to previous studies in adults, green exercise did not produce significantly greater increases in self-esteem than the urban exercise condition. Green exercise was enjoyed more equally by children with differing levels of habitual physical activity and has the potential to engage less active children in exercise.

  5. Manual versus automatic bladder wall thickness measurements: a method comparison study

    NARCIS (Netherlands)

    Oelke, M.; Mamoulakis, C.; Ubbink, D.T.; de la Rosette, J.J.; Wijkstra, H.

    2009-01-01

    Purpose To compare repeatability and agreement of conventional ultrasound bladder wall thickness (BWT) measurements with automatically obtained BWT measurements by the BVM 6500 device. Methods Adult patients with lower urinary tract symptoms, urinary incontinence, or postvoid residual urine were

  6. Repeatability of Computerized Tomography-Based Anthropomorphic Measurements of Frailty in Patients With Pulmonary Fibrosis Undergoing Lung Transplantation.

    Science.gov (United States)

    McClellan, Taylor; Allen, Brian C; Kappus, Matthew; Bhatti, Lubna; Dafalla, Randa A; Snyder, Laurie D; Bashir, Mustafa R

    To determine interreader and intrareader repeatability and correlations among measurements of computerized tomography-based anthropomorphic measurements in patients with pulmonary fibrosis undergoing lung transplantation. This was an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study of 23 randomly selected subjects (19 male and 4 female; median age = 69 years; range: 66-77 years) with idiopathic pulmonary fibrosis undergoing pulmonary transplantation, who had also undergone preoperative thoracoabdominal computerized tomography. Five readers of varying imaging experience independently performed the following cross-sectional area measurements at the inferior endplate of the L3 vertebral body: right and left psoas muscles, right and left paraspinal muscles, total abdominal musculature, and visceral and subcutaneous fat. The following measurements were obtained at the inferior endplate of T6: right and left paraspinal muscles with and without including the trapezius muscles and subcutaneous fat. Three readers repeated all measurements to assess intrareader repeatability. Intrareader repeatability was nearly perfect (interclass correlation coefficients = 0.99, P < 0.001). Interreader agreement was excellent across all 5 readers (interclass correlation coefficients: 0.71-0.99, P < 0.001). Coefficients of variance between measures ranged from 3.2%-6.8% for abdominal measurements, but were higher for thoracic measurements, up to 23.9%. Correlation between total paraspinal and total psoas muscle area was strong (r 2 = 0.67, P < 0.001). Thoracic and abdominal musculature had a weaker correlation (r 2 = 0.35-0.38, P < 0.001). Measures of thoracic and abdominal muscle and fat area are highly repeatable in patients with pulmonary fibrosis undergoing lung transplantation. Measures of muscle area are strongly correlated among abdominal locations, but inversely correlated between abdominal and thoracic locations

  7. Recommendations for analysis of repeated-measures designs: testing and correcting for sphericity and use of manova and mixed model analysis.

    Science.gov (United States)

    Armstrong, Richard A

    2017-09-01

    A common experimental design in ophthalmic research is the repeated-measures design in which at least one variable is a within-subject factor. This design is vulnerable to lack of 'sphericity' which assumes that the variances of the differences among all possible pairs of within-subject means are equal. Traditionally, this design has been analysed using a repeated-measures analysis of variance (RM-anova) but increasingly more complex methods such as multivariate anova (manova) and mixed model analysis (MMA) are being used. This article surveys current practice in the analysis of designs incorporating different factors in research articles published in three optometric journals, namely Ophthalmic and Physiological Optics (OPO), Optometry and Vision Science (OVS), and Clinical and Experimental Optometry (CXO), and provides advice to authors regarding the analysis of repeated-measures designs. Of the total sample of articles, 66% used a repeated-measures design. Of those articles using a repeated-measures design, 59% and 8% analysed the data using RM-anova or manova respectively and 33% used MMA. The use of MMA relative to RM-anova has increased significantly since 2009/10. A further search using terms to select those papers testing and correcting for sphericity ('Mauchly's test', 'Greenhouse-Geisser', 'Huynh and Feld') identified 66 articles, 62% of which were published from 2012 to the present. If the design is balanced without missing data then manova should be used rather than RM-anova as it gives better protection against lack of sphericity. If the design is unbalanced or with missing data then MMA is the method of choice. However, MMA is a more complex analysis and can be difficult to set up and run, and care should be taken first, to define appropriate models to be tested and second, to ensure that sample sizes are adequate. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

  8. Comparison of anterior segment measurements using Sirius Topographer® and Nidek Axial Length-Scan® with assessing repeatability in patients with cataracts

    Directory of Open Access Journals (Sweden)

    Resat Duman

    2018-01-01

    Full Text Available Purpose: The purpose of this study is to evaluate anterior segment measurements obtained using CSO Sirius Topographer® (CSO, Firenze, Italy and Nidek Axial Length (AL-Scan® (Nidek CO., Gamagori, Japan. Methods: A total of 43 eyes of 43 patients were included in this prospective study. The central corneal thickness (CCT, anterior chamber depth (ACD, white-to-white distance (WTW, flat keratometry (K1, steep keratometry (K2, and mean keratometry (K values were randomly measured three times with each device by the same examiner. The intraclass correlation coefficient of repeatability was analyzed. The compatibility of both devices was evaluated using the 95% limits of the agreement proposed by Bland and Altman. Results: Examiner achieved high repeatability for all parameters on each device except the WTW measured by Sirius. All measurements except WTW and K1 taken with the Sirius were higher than that taken with the Nidek AL-Scan®. The difference in CCT, ACD, and WTW values was statistically significant. Conclusion: High repeatability of the measurements was achieved on both devices. Although Km, K1, and K2 measurements of the Sirius and the AL-Scan® showed good agreement, WTW, CCT, and ACD measurements significantly differed between two devices. Thus, anterior segment measurements except for Km, K1, and K2 cannot be used interchangeably between Sirius and Nidek AL-Scan® devices.

  9. A repeatable and scalable fabrication method for sharp, hollow silicon microneedles

    Science.gov (United States)

    Kim, H.; Theogarajan, L. S.; Pennathur, S.

    2018-03-01

    Scalability and manufacturability are impeding the mass commercialization of microneedles in the medical field. Specifically, microneedle geometries need to be sharp, beveled, and completely controllable, difficult to achieve with microelectromechanical fabrication techniques. In this work, we performed a parametric study using silicon etch chemistries to optimize the fabrication of scalable and manufacturable beveled silicon hollow microneedles. We theoretically verified our parametric results with diffusion reaction equations and created a design guideline for a various set of miconeedles (80-160 µm needle base width, 100-1000 µm pitch, 40-50 µm inner bore diameter, and 150-350 µm height) to show the repeatability, scalability, and manufacturability of our process. As a result, hollow silicon microneedles with any dimensions can be fabricated with less than 2% non-uniformity across a wafer and 5% deviation between different processes. The key to achieving such high uniformity and consistency is a non-agitated HF-HNO3 bath, silicon nitride masks, and surrounding silicon filler materials with well-defined dimensions. Our proposed method is non-labor intensive, well defined by theory, and straightforward for wafer scale mass production, opening doors to a plethora of potential medical and biosensing applications.

  10. Heart failure re-admission: measuring the ever shortening gap between repeat heart failure hospitalizations.

    Directory of Open Access Journals (Sweden)

    Jeffrey A Bakal

    Full Text Available Many quality-of-care and risk prediction metrics rely on time to first rehospitalization even though heart failure (HF patients may undergo several repeat hospitalizations. The aim of this study is to compare repeat hospitalization models. Using a population-based cohort of 40,667 patients, we examined both HF and all cause re-hospitalizations using up to five years of follow-up. Two models were examined: the gap-time model which estimates the adjusted time between hospitalizations and a multistate model which considered patients to be in one of four states; community-dwelling, in hospital for HF, in hospital for any reason, or dead. The transition probabilities and times were then modeled using patient characteristics and number of repeat hospitalizations. We found that during the five years of follow-up roughly half of the patients returned for a subsequent hospitalization for each repeat hospitalization. Additionally, we noted that the unadjusted time between hospitalizations was reduced ∼40% between each successive hospitalization. After adjustment each additional hospitalization was associated with a 28 day (95% CI: 22-35 reduction in time spent out of hospital. A similar pattern was seen when considering the four state model. A large proportion of patients had multiple repeat hospitalizations. Extending the gap between hospitalizations should be an important goal of treatment evaluation.

  11. Effect of repeated sterilization by different methods on strength of carbon fiber rods used in external fixator systems.

    Science.gov (United States)

    Unal, Omer Kays; Poyanli, Oguz Sukru; Unal, Ulku Sur; Mutlu, Hasan Huseyin; Ozkut, Afsar Timucin; Esenkaya, Irfan

    2018-05-16

    We set out to reveal the effects of repeated sterilization, using different methods, on the carbon fiber rods of external fixator systems. We used a randomized set of forty-four unused, unsterilized, and identical carbon fiber rods (11 × 200 mm), randomly assigned to two groups: unsterilized (US) (4 rods) and sterilized (40 rods). The sterilized rods were divided into two groups, those sterilized in an autoclave (AC) and by hydrogen peroxide (HP). These were further divided into five subgroups based on the number of sterilization repetition to which the fibers were subjected (25-50-75-100-200). A bending test was conducted to measure the maximum bending force (MBF), maximum deflection (MD), flexural strength (FS), maximum bending moment (MBM) and bending rigidity (BR). We also measured the surface roughness of the rods. An increase in the number of sterilization repetition led to a decrease in MBF, MBM, FS, BR, but increased MD and surface roughness (p < 0.01). The effect of the number of sterilization repetition was more prominent in the HP group. This study revealed that the sterilization method and number of sterilization repetition influence the strength of the carbon fiber rods. Increasing the number of sterilization repetition degrades the strength and roughness of the rods.

  12. The effect of repeated measurements and working memory on the most comfortable level in the ANL test.

    Science.gov (United States)

    Brännström, K Jonas; Olsen, Steen Østergaard; Holm, Lucas; Kastberg, Tobias; Ibertsson, Tina

    2014-11-01

    To study the effect of a large number of repetitions on the most comfortable level (MCL) when doing the acceptable noise level (ANL) test, and explore if MCL variability is related to central cognitive processes. Twelve MCL repetitions were measured within the ANL test using interleaved methodology during one session using a non-semantic version. Phonological (PWM) and visuospatial working memory (VSWM) was measured. Thirty-two normal-hearing adults. Repeated measures ANOVA, intraclass correlations, and the coefficient of repeatability (CR) were used to assess the repeatability. Repeated measures ANOVA and CR indicated poor agreement between the two first repetitions. After excluding the first repetition, analyses showed that the MCL in the ANL test is reliable. A negative association was found between PWM and MCL variability indicating that subjects with higher PWM show less variability. The findings suggest that, after excluding the first repetition, the MCL in the ANL test is reliable. A single repetition of the MCL in the ANL test should be avoided. If an interleaved methodology is used, a single ANL repetition should be added prior to the actual testing. The findings also suggest that MCL variability is associated to PWM but not VSWM.

  13. Renewable energy: Method and measures

    International Nuclear Information System (INIS)

    Nilsen, Trond Hartvedt

    2003-01-01

    The thesis presents various possibilities for renewable energy in Norway. The wind power would give a practical and economic alternative. The external costs for the wind power would be moderate. In chapter 3 the utility cost analysis for renewable alternatives are studied relative to the macroeconomic efficiency. Some methodical problems and how these analyses are used are reviewed. In the practical utility cost analyses wind power is studied relative to gas power which is the non-renewable alternative present in Norway today. A qualitative part is included. It is not possible to determine whether wind power is preferable to gas power in the macroeconomic perspective. Wind power would be the choice if high environmental and CO2 cleaning costs are expected. The first conclusion to be drawn is that it is difficult to decide whether wind power is the best solution based on cost benefit analysis. However, the alternative seems to be quite robust in the analysis. Due to the central position the energy supplies have in the society this business should be heavily regulated. The sector is also overtaxed as a reduction in consumption is desired. The analysis shows that the system does not function perfectly. The thesis surveys various measures for improving the renewable energy supply and focuses on the wind power. A model for and analysis of the measures are carried out and resulted in a second conclusion. The measures have various properties as to the influence on the market. A subsidy is a fine measure for stimulation production of green power while a tax reduces efficiently the production of black power. A system with green licenses in combination with a subsidy and a tax would be preferable as to increasing the part of renewable energy of the total production. It is therefore necessary to have clearly defined goals and use suitable measures for achieving them. The costs of wind power is falling and it would therefore soon be macroeconomic profitable. It is also

  14. Comparing a single case to a control group - Applying linear mixed effects models to repeated measures data.

    Science.gov (United States)

    Huber, Stefan; Klein, Elise; Moeller, Korbinian; Willmes, Klaus

    2015-10-01

    In neuropsychological research, single-cases are often compared with a small control sample. Crawford and colleagues developed inferential methods (i.e., the modified t-test) for such a research design. In the present article, we suggest an extension of the methods of Crawford and colleagues employing linear mixed models (LMM). We first show that a t-test for the significance of a dummy coded predictor variable in a linear regression is equivalent to the modified t-test of Crawford and colleagues. As an extension to this idea, we then generalized the modified t-test to repeated measures data by using LMMs to compare the performance difference in two conditions observed in a single participant to that of a small control group. The performance of LMMs regarding Type I error rates and statistical power were tested based on Monte-Carlo simulations. We found that starting with about 15-20 participants in the control sample Type I error rates were close to the nominal Type I error rate using the Satterthwaite approximation for the degrees of freedom. Moreover, statistical power was acceptable. Therefore, we conclude that LMMs can be applied successfully to statistically evaluate performance differences between a single-case and a control sample. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Accurate color measurement methods for medical displays.

    Science.gov (United States)

    Saha, Anindita; Kelley, Edward F; Badano, Aldo

    2010-01-01

    The necessity for standard instrumentation and measurements of color that are repeatable and reproducible is the major motivation behind this work. Currently, different instrumentation and methods can yield very different results when measuring the same feature such as color uniformity or color difference. As color increasingly comes into play in medical imaging diagnostics, display color will have to be quantified in order to assess whether the display should be used for imaging purposes. The authors report on the characterization of three novel probes for measuring display color with minimal contamination from screen areas outside the measurement spot or from off-normal emissions. They compare three probe designs: A modified small-spot luminance probe and two conic probe designs based on black frusta. To compare the three color probe designs, spectral and luminance measurements were taken with specialized instrumentation to determine the luminance changes and color separation abilities of the probes. The probes were characterized with a scanning slit method, veiling glare, and a moving laser and LED arrangement. The scanning slit measurement was done using a black slit plate over a white line on an LCD monitor. The luminance was measured in 1 mm increments from the center of the slit to +/- 15 mm above and below the slit at different distances between the probe and the slit. The veiling glare setup consisted of measurements of the luminance of a black spot pattern with a white disk of radius of 100 mm as the black spot increases in 1 mm radius increments. The moving LED and laser method consisted of a red and green light orthogonal to the probe tip for the light to directly shine into the probe. The green light source was moved away from the red source in 1 cm increments to measure color stray-light contamination at different probe distances. The results of the color testing using the LED and laser methods suggest a better performance of one of the frusta probes

  16. Method of measuring surface density

    International Nuclear Information System (INIS)

    Gregor, J.

    1982-01-01

    A method is described of measuring surface density or thickness, preferably of coating layers, using radiation emitted by a suitable radionuclide, e.g., 241 Am. The radiation impinges on the measured material, e.g., a copper foil and in dependence on its surface density or thickness part of the flux of impinging radiation is reflected and part penetrates through the material. The radiation which has penetrated through the material excites in a replaceable adjustable backing characteristic radiation of an energy close to that of the impinging radiation (within +-30 keV). Part of the flux of the characteristic radiation spreads back to the detector, penetrates through the material in which in dependence on surface density or thickness of the coating layer it is partly absorbed. The flux of the penetrated characteristic radiation impinging on the face of the detector is a function of surface density or thickness. Only that part of the energy is evaluated of the energy spectrum which corresponds to the energy of characteristic radiation. (B.S.)

  17. Repeatability of measures of inflammatory cell number in bronchial biopsies in atopic asthma

    NARCIS (Netherlands)

    Sont, J. K.; Willems, L. N.; Evertse, C. E.; Hooijer, R.; Sterk, P. J.; van Krieken, J. H.

    1997-01-01

    Airway pathology is increasingly considered to be a major outcome in asthma research. The aim of this study was to examine the intra-observer, within-section and between-biopsy repeatability, together with the implications for statistical power of a computerized quantitative analysis of inflammatory

  18. Validation and Reliability of a Smartphone Application for the International Prostate Symptom Score Questionnaire: A Randomized Repeated Measures Crossover Study

    Science.gov (United States)

    Shim, Sung Ryul; Sun, Hwa Yeon; Ko, Young Myoung; Chun, Dong-Il; Yang, Won Jae

    2014-01-01

    Background Smartphone-based assessment may be a useful diagnostic and monitoring tool for patients. There have been many attempts to create a smartphone diagnostic tool for clinical use in various medical fields but few have demonstrated scientific validity. Objective The purpose of this study was to develop a smartphone application of the International Prostate Symptom Score (IPSS) and to demonstrate its validity and reliability. Methods From June 2012 to May 2013, a total of 1581 male participants (≥40 years old), with or without lower urinary tract symptoms (LUTS), visited our urology clinic via the health improvement center at Soonchunhyang University Hospital (Republic of Korea) and were enrolled in this study. A randomized repeated measures crossover design was employed using a smartphone application of the IPSS and the conventional paper form of the IPSS. Paired t test under a hypothesis of non-inferior trial was conducted. For the reliability test, the intraclass correlation coefficient (ICC) was measured. Results The total score of the IPSS (P=.289) and each item of the IPSS (P=.157-1.000) showed no differences between the paper version and the smartphone version of the IPSS. The mild, moderate, and severe LUTS groups showed no differences between the two versions of the IPSS. A significant correlation was noted in the total group (ICC=.935, Psmartphones could participate. Conclusions The validity and reliability of the smartphone application version were comparable to the conventional paper version of the IPSS. The smartphone application of the IPSS could be an effective method for measuring lower urinary tract symptoms. PMID:24513507

  19. Reliability of near-infrared spectroscopy for measuring biceps brachii oxygenation during sustained and repeated isometric contractions.

    Science.gov (United States)

    Muthalib, Makii; Millet, Guillaume Y; Quaresima, Valentina; Nosaka, Kazunori

    2010-01-01

    We examine the test-retest reliability of biceps brachii tissue oxygenation index (TOI) parameters measured by near-infrared spectroscopy during a 10-s sustained and a 30-repeated (1-s contraction, 1-s relaxation) isometric contraction task at 30% of maximal voluntary contraction (30% MVC) and maximal (100% MVC) intensities. Eight healthy men (23 to 33 yr) were tested on three sessions separated by 3 h and 24 h, and the within-subject reliability of torque and each TOI parameter were determined by Bland-Altman+/-2 SD limits of agreement plots and coefficient of variation (CV). No significant (P>0.05) differences between the three sessions were found for mean values of torque and TOI parameters during the sustained and repeated tasks at both contraction intensities. All TOI parameters were within+/-2 SD limits of agreement. The CVs for torque integral were similar between the sustained and repeated task at both intensities (4 to 7%); however, the CVs for TOI parameters during the sustained and repeated task were lower for 100% MVC (7 to 11%) than for 30% MVC (22 to 36%). It is concluded that the reliability of the biceps brachii NIRS parameters during both sustained and repeated isometric contraction tasks is acceptable.

  20. Analyzing repeated data collected by mobile phones and frequent text messages. An example of Low back pain measured weekly for 18 weeks

    Directory of Open Access Journals (Sweden)

    Axén Iben

    2012-07-01

    Full Text Available Abstract Background Repeated data collection is desirable when monitoring fluctuating conditions. Mobile phones can be used to gather such data from large groups of respondents by sending and receiving frequently repeated short questions and answers as text messages. The analysis of repeated data involves some challenges. Vital issues to consider are the within-subject correlation, the between measurement occasion correlation and the presence of missing values. The overall aim of this commentary is to describe different methods of analyzing repeated data. It is meant to give an overview for the clinical researcher in order for complex outcome measures to be interpreted in a clinically meaningful way. Methods A model data set was formed using data from two clinical studies, where patients with low back pain were followed with weekly text messages for 18 weeks. Different research questions and analytic approaches were illustrated and discussed, as well as the handling of missing data. In the applications the weekly outcome “number of days with pain” was analyzed in relation to the patients’ “previous duration of pain” (categorized as more or less than 30 days in the previous year. Research questions with appropriate analytical methods 1: How many days with pain do patients experience? This question was answered with data summaries. 2: What is the proportion of participants “recovered” at a specific time point? This question was answered using logistic regression analysis. 3: What is the time to recovery? This question was answered using survival analysis, illustrated in Kaplan-Meier curves, Proportional Hazard regression analyses and spline regression analyses. 4: How is the repeatedly measured data associated with baseline (predictor variables? This question was answered using generalized Estimating Equations, Poisson regression and Mixed linear models analyses. 5: Are there subgroups of patients with similar courses of pain

  1. Automated Methods Of Corrosion Measurements

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers; Andersen, Jens Enevold Thaulov; Reeve, John Ch

    1997-01-01

    The chapter describes the following automated measurements: Corrosion Measurements by Titration, Imaging Corrosion by Scanning Probe Microscopy, Critical Pitting Temperature and Application of the Electrochemical Hydrogen Permeation Cell.......The chapter describes the following automated measurements: Corrosion Measurements by Titration, Imaging Corrosion by Scanning Probe Microscopy, Critical Pitting Temperature and Application of the Electrochemical Hydrogen Permeation Cell....

  2. "Focused introspection" during naturally increased diuresis: description and repeatability of a method to study bladder sensation non-invasively.

    Science.gov (United States)

    De Wachter, Stefan G G; Heeringa, Rhea; Van Koeveringe, Gommert A; Winkens, Bjorn; Van Kerrebroeck, Philip E V; Gillespie, James I

    2014-06-01

    To present and describe a non-invasive method to study the origin and development of bladder filling sensation and to evaluate the repeatability of the method. Eighteen volunteers participated in the study and were given a water loading protocol consisting of 1,000 ml water intake 1 hr before the session and 200 ml every 10 min during the session. Protocol 1: To evaluate diuresis rate, seven participants were asked to void every 15 min and the voided volume was measured. Protocol 2: Eleven volunteers graded bladder sensation on regular time points, on an empty graph with time on the X-axis and intensity of sensation on the Y-axis. The protocol ended at absolute need to void (maximal intensity) and voided volumes were measured. This protocol was conducted three times with a 10 days interval. Protocol 1: The diuresis rate was not different during the sessions and showed no variation over the studied time period (P = 0.2). Protocol 2: For an individual, the diuresis rate was not different between the sessions. The curves in all patients showed a continuously increasing bladder intensity. In seven participants the curve was convex, in the other four, the curve was sigmoidal. For each individual the pattern was constant during the three sessions. A strict water loading protocol induces a constant diuresis. This allows individuals to draw an introspection bladder sensation curve with a specific shape, which can be used as a method to study the development of bladder sensation non-invasively. © 2013 Wiley Periodicals, Inc.

  3. An open source, 3D printed preclinical MRI phantom for repeated measures of contrast agents and reference standards.

    Science.gov (United States)

    Cox, B L; Ludwig, K D; Adamson, E B; Eliceiri, K W; Fain, S B

    2018-03-01

    In medical imaging, clinicians, researchers and technicians have begun to use 3D printing to create specialized phantoms to replace commercial ones due to their customizable and iterative nature. Presented here is the design of a 3D printed open source, reusable magnetic resonance imaging (MRI) phantom, capable of flood-filling, with removable samples for measurements of contrast agent solutions and reference standards, and for use in evaluating acquisition techniques and image reconstruction performance. The phantom was designed using SolidWorks, a computer-aided design software package. The phantom consists of custom and off-the-shelf parts and incorporates an air hole and Luer Lock system to aid in flood filling, a marker for orientation of samples in the filled mode and bolt and tube holes for assembly. The cost of construction for all materials is under $90. All design files are open-source and available for download. To demonstrate utility, B 0 field mapping was performed using a series of gadolinium concentrations in both the unfilled and flood-filled mode. An excellent linear agreement (R 2 >0.998) was observed between measured relaxation rates (R 1 /R 2 ) and gadolinium concentration. The phantom provides a reliable setup to test data acquisition and reconstruction methods and verify physical alignment in alternative nuclei MRI techniques (e.g. carbon-13 and fluorine-19 MRI). A cost-effective, open-source MRI phantom design for repeated quantitative measurement of contrast agents and reference standards in preclinical research is presented. Specifically, the work is an example of how the emerging technology of 3D printing improves flexibility and access for custom phantom design.

  4. Power analysis for multivariate and repeated measurements designs via SPSS: correction and extension of D'Amico, Neilands, and Zambarano (2001).

    Science.gov (United States)

    Osborne, Jason W

    2006-05-01

    D'Amico, Neilands, and Zambarano (2001) published SPSS syntax to perform power analyses for three complex procedures: ANCOVA, MANOVA, and repeated measures ANOVA. Unfortunately, the published SPSS syntax for performing the repeated measures analysis needed some minor revision in order to perform the analysis correctly. This article presents the corrected syntax that will successfully perform the repeated measures analysis and provides some guidance on modifying the syntax to customize the analysis.

  5. Measuring Aseismic Slip through Characteristically Repeating Earthquakes at the Mendocino Triple Junction, Northern California

    Science.gov (United States)

    Materna, K.; Taira, T.; Burgmann, R.

    2016-12-01

    The Mendocino Triple Junction (MTJ), at the transition point between the San Andreas fault system, the Mendocino Transform Fault, and the Cascadia Subduction Zone, undergoes rapid tectonic deformation and produces more large (M>6.0) earthquakes than any region in California. Most of the active faults of the triple junction are located offshore, making it difficult to characterize both seismic slip and aseismic creep. In this work, we study aseismic creep rates near the MTJ using characteristically repeating earthquakes (CREs) as indicators of creep rate. CREs are generally interpreted as repeated failures of the same seismic patch within an otherwise creeping fault zone; as a consequence, the magnitude and recurrence time of the CREs can be used to determine a fault's creep rate through empirically calibrated scaling relations. Using seismic data from 2010-2016, we identify CREs as recorded by an array of eight 100-Hz PBO borehole seismometers deployed in the Cape Mendocino area. For each event pair with epicenters less than 30 km apart, we compute the cross-spectral coherence of 20 seconds of data starting one second before the P-wave arrival. We then select pairs with high coherence in an appropriate frequency band, which is determined uniquely for each event pair based on event magnitude, station distance, and signal-to-noise ratio. The most similar events (with median coherence above 0.95 at two or more stations) are selected as CREs and then grouped into CRE families, and each family is used to infer a local creep rate. On the Mendocino Transform Fault, we find relatively high creep rates of >5 cm/year that increase closer to the Gorda Ridge. Closer to shore and to the MTJ itself, we find many families of repeaters on and off the transform fault with highly variable creep rates, indicative of the complex deformation that takes place there.

  6. Determinants and Experiences of Repeat Pregnancy among HIV-Positive Kenyan Women--A Mixed-Methods Analysis.

    Directory of Open Access Journals (Sweden)

    Victor Akelo

    Full Text Available To identify factors associated with repeat pregnancy subsequent to an index pregnancy among women living with HIV (WLWH in western Kenya who were enrolled in a 24-month phase-II clinical trial of triple-ART prophylaxis for prevention of mother-to-child transmission, and to contextualize social and cultural influences on WLWH's reproductive decision making.A mixed-methods approach was used to examine repeat pregnancy within a 24 month period after birth. Counselor-administered questionnaires were collected from 500 WLWH. Forty women (22 with a repeat pregnancy; 18 with no repeat pregnancy were purposively selected for a qualitative interview (QI. Simple and multiple logistic regression analyses were performed for quantitative data. Thematic coding and saliency analysis were undertaken for qualitative data.Eighty-eight (17.6% women had a repeat pregnancy. Median maternal age was 23 years (range 15-43 years and median gestational age at enrollment was 34 weeks. In multiple logistic regression analyses, living in the same compound with a husband (adjusted odds ratio (AOR: 2.33; 95% confidence interval (CI: 1.14, 4.75 was associated with increased odds of repeat pregnancy (p ≤ 0.05. Being in the 30-43 age group (AOR: 0.25; 95% CI: 0.07, 0.87, having talked to a partner about family planning (FP use (AOR: 0.53; 95% CI: 0.29, 0.98, and prior usage of FP (AOR: 0.45; 95% CI: 0.25, 0.82 were associated with a decrease in odds of repeat pregnancy. QI findings centered on concerns about modern contraception methods (side effects and views that they 'ruined the womb' and a desire to have the right number of children. Religious leaders, family, and the broader community were viewed as reinforcing cultural expectations for married women to have children. Repeat pregnancy was commonly attributed to contraception failure or to lack of knowledge about post-delivery fertility.In addition to cultural context, reproductive health programs for WLWH may need to

  7. Methods to Measure Map Readability

    OpenAIRE

    Harrie, Lars

    2009-01-01

    Creation of maps in real-time web services introduces challenges concerning map readability. Therefore we must introduce analytical measures controlling the readability. The aim of this study is to develop and evaluate analytical readability measures with the help of user tests.

  8. A Method against Interrupted-Sampling Repeater Jamming Based on Energy Function Detection and Band-Pass Filtering

    Directory of Open Access Journals (Sweden)

    Hui Yuan

    2017-01-01

    Full Text Available Interrupted-sampling repeater jamming (ISRJ is a new kind of coherent jamming to the large time-bandwidth linear frequency modulation (LFM signal. Many jamming modes, such as lifelike multiple false targets and dense false targets, can be made through setting up different parameters. According to the “storage-repeater-storage-repeater” characteristics of the ISRJ and the differences in the time-frequency-energy domain between the ISRJ signal and the target echo signal, one new method based on the energy function detection and band-pass filtering is proposed to suppress the ISRJ. The methods mainly consist of two parts: extracting the signal segments without ISRJ and constructing band-pass filtering function with low sidelobe. The simulation results show that the method is effective in the ISRJ with different parameters.

  9. Can father inclusive practice reduce paternal postnatal anxiety? A repeated measures cohort study using the hospital anxiety and depression scale

    Directory of Open Access Journals (Sweden)

    Tohotoa Jenny

    2012-07-01

    Full Text Available Abstract Background Perinatal research on anxiety and depression has primarily focused on mothers. We have limited knowledge of fathers’ anxiety during the perinatal period yet there is evidence that the parenting capacity of a person can be compromised by anxiety and depression. The purpose of this paper is to identify the impact of a father inclusive intervention on perinatal anxiety and depression. The prime focus of the intervention was to provide education and support to fathers of breastfeeding partners with the aim of increasing both initiation and duration of breastfeeding. Methods A repeated measures cohort study was conducted during a RCT that was implemented across eight public maternity hospitals in Perth, Western Australia between May 2008 and June 2009. A baseline questionnaire which included the Hospital Anxiety and Depression Scale (HADS was administered to all participants on the first night of their hospital based antenatal education program and was repeated at six weeks postnatal. SPSS version 17 was used for reporting descriptive results. Results The mean anxiety levels at baseline for the fathers in the intervention group (n=289 and control group (n=244 were 4.58 and 4.22 respectively. At 6 weeks postnatal (only matched pairs, intervention and control group were 3.93 and 3.79. More intervention group fathers self-rated less anxiety compared to the fathers in the control group from baseline to post test (p=0.048. Depression scores for intervention fathers at baseline (mean =1.09 and at six weeks (mean=1.09 were very similar to fathers in the control group at baseline (mean=1.11 and at six weeks (mean =1.07 with no significant changes. Conclusions Both intervention and control group fathers experienced some anxiety prior to the birth of their baby, but this was rapidly reduced at six weeks. Paternal anxiety is common to new fathers and providing them with information and strategies for problem-solving can increase their

  10. Long-term, repeated measurements of mouse cortical microflow at the same region of interest with high spatial resolution.

    Science.gov (United States)

    Tomita, Yutaka; Pinard, Elisabeth; Tran-Dinh, Alexy; Schiszler, Istvan; Kubis, Nathalie; Tomita, Minoru; Suzuki, Norihiro; Seylaz, Jacques

    2011-02-04

    A method for long-term, repeated, semi-quantitative measurements of cerebral microflow at the same region of interest (ROI) with high spatial resolution was developed and applied to mice subjected to focal arterial occlusion. A closed cranial window was chronically implanted over the left parieto-occipital cortex. The anesthetized mouse was placed several times, e.g., weekly, under a dynamic confocal microscope, and Rhodamine B-isothiocyanate-dextran was each time intravenously injected as a bolus, while microflow images were video recorded. Left and right tail veins were sequentially catheterized in a mouse three times at maximum over a 1.5 months' observation period. Smearing of the input function resulting from the use of intravenous injection was shown to be sufficiently small. The distal middle cerebral artery (MCA) was thermocoagulated through the cranial window in six mice, and five sham-operated mice were studied in parallel. Dye injection and video recording were conducted four times in this series, i.e., before and at 10 min, 7 and 30 days after sham operation or MCA occlusion. Pixelar microflow values (1/MTT) in a matrix of approximately 50×50 pixels were displayed on a two-dimensional (2-D) map, and the frequency distribution of the flow values was also calculated. No significant changes in microflow values over time were detected in sham-operated mice, while the time course of flow changes in the ischemic penumbral area in operated mice was similar to those reported in the literature. This method provides a powerful tool to investigate long-term changes in mouse cortical microflow under physiological and pathological conditions. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Reliability and Repeatability of Cone Density Measurements in Patients With Stargardt Disease and RPGR-Associated Retinopathy.

    Science.gov (United States)

    Tanna, Preena; Kasilian, Melissa; Strauss, Rupert; Tee, James; Kalitzeos, Angelos; Tarima, Sergey; Visotcky, Alexis; Dubra, Alfredo; Carroll, Joseph; Michaelides, Michel

    2017-07-01

    To assess reliability and repeatability of cone density measurements by using confocal and (nonconfocal) split-detector adaptive optics scanning light ophthalmoscopy (AOSLO) imaging. It will be determined whether cone density values are significantly different between modalities in Stargardt disease (STGD) and retinitis pigmentosa GTPase regulator (RPGR)-associated retinopathy. Twelve patients with STGD (aged 9-52 years) and eight with RPGR-associated retinopathy (aged 11-31 years) were imaged using both confocal and split-detector AOSLO simultaneously. Four graders manually identified cone locations in each image that were used to calculate local densities. Each imaging modality was evaluated independently. The data set consisted of 1584 assessments of 99 STGD images (each image in two modalities and four graders who graded each image twice) and 928 RPGR assessments of 58 images (each image in two modalities and four graders who graded each image twice). For STGD assessments the reliability for confocal and split-detector AOSLO was 67.9% and 95.9%, respectively, and the repeatability was 71.2% and 97.3%, respectively. The differences in the measured cone density values between modalities were statistically significant for one grader. For RPGR assessments the reliability for confocal and split-detector AOSLO was 22.1% and 88.5%, respectively, and repeatability was 63.2% and 94.5%, respectively. The differences in cone density between modalities were statistically significant for all graders. Split-detector AOSLO greatly improved the reliability and repeatability of cone density measurements in both disorders and will be valuable for natural history studies and clinical trials using AOSLO. However, it appears that these indices may be disease dependent, implying the need for similar investigations in other conditions.

  12. Understanding how adherence goals promote adherence behaviours: a repeated measure observational study with HIV seropositive patients

    Directory of Open Access Journals (Sweden)

    Jones Gareth

    2012-08-01

    Full Text Available Abstract Background The extent to which patients follow treatments as prescribed is pivotal to treatment success. An exceptionally high level (> 95% of HIV medication adherence is required to suppress viral replication and protect the immune system and a similarly high level (> 80% of adherence has also been suggested in order to benefit from prescribed exercise programmes. However, in clinical practice, adherence to both often falls below the desirable level. This project aims to investigate a wide range of psychological and personality factors that may lead to adherence/non-adherence to medical treatment and exercise programmes. Methods HIV positive patients who are referred to the physiotherapist-led 10-week exercise programme as part of the standard care are continuously recruited. Data on social cognitive variables (attitude, intention, subjective norms, self-efficacy, and outcome beliefs about the goal and specific behaviours, selected personality factors, perceived quality of life, physical activity, self-reported adherence and physical assessment are collected at baseline, at the end of the exercise programme and again 3 months later. The project incorporates objective measures of both exercise (attendance log and improvement in physical measures such as improved fitness level, weight loss, improved circumferential anthropometric measures and medication adherence (verified by non-invasive hair analysis. Discussion The novelty of this project comes from two key aspects, complemented with objective information on exercise and medication adherence. The project assesses beliefs about both the underlying goal such as following prescribed treatment; and about the specific behaviours such as undertaking the exercise or taking the medication, using both implicit and explicit assessments of patients’ beliefs and attitudes. We predict that i the way people think about the underlying goal of their treatments explains medication and exercise

  13. EFFICIENCY OF REPEATED AND UNSCHEDULED TRAINING AS THE MEASURES TO PREVENT ACCIDENTS AT SUPPLY DEPOTS AND WAREHOUSES

    Directory of Open Access Journals (Sweden)

    Bocharova Irina Nikolaevna

    2013-05-01

    Full Text Available This paper presents the results of the analysis of the state of occupational safety at supply depots and warehouses. It is revealed that most accidents involve the employees who have less than one year’s service. Experience has proven that the preventive activities to avoid occupational traumatism are efficient when a complex of workplace safety measures is implemented. The experts consider the repeated and unscheduled training to be very important events. This is supported by the fact that among the employees of the commercial establishments who underwent repeated and unscheduled training, the number of individuals who suffered an accident is small. The efficient functioning of the occupational safety training system is infeasible without ensuring the motivation for assimilating the knowledge and forming the complete foundation for safe labor. In order to reduce the number of accidents, one should proceed from the principle of responding to accidents to the system for professional risk management.

  14. Low level TOC measurement method

    Science.gov (United States)

    Ekechukwu, Amy A.

    2001-01-01

    A method for the determination of total organic carbon in an aqueous sample by trapping the organic matter on a sorbent which is carbon free and analyzing the sorbent by combustion and determination of total CO.sub.2 by IR.

  15. Automated Methods of Corrosion Measurements

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    1997-01-01

    . Mechanical control, recording, and data processing must therefore be automated to a high level of precision and reliability. These general techniques and the apparatus involved have been described extensively. The automated methods of such high-resolution microscopy coordinated with computerized...

  16. Interactional justice at work is related to sickness absence: a study using repeated measures in the Swedish working population.

    Science.gov (United States)

    Leineweber, Constanze; Bernhard-Oettel, Claudia; Peristera, Paraskevi; Eib, Constanze; Nyberg, Anna; Westerlund, Hugo

    2017-12-08

    Research has shown that perceived unfairness contributes to higher rates of sickness absence. While shorter, but more frequent periods of sickness absence might be a possibility for the individual to get relief from high strain, long-term sickness absence might be a sign of more serious health problems. The Uncertainty Management Model suggests that justice is particularly important in times of uncertainty, e.g. perceived job insecurity. The present study investigated the association between interpersonal and informational justice at work with long and frequent sickness absence respectively, under conditions of job insecurity. Data were derived from the 2010, 2012, and 2014 biennial waves of the Swedish Longitudinal Occupational Survey of Health (SLOSH). The final analytic sample consisted of 19,493 individuals. We applied repeated measures regression analyses through generalized estimating equations (GEE), a method for longitudinal data that simultaneously analyses variables at different time points. We calculated risk of long and frequent sickness absence, respectively in relation to interpersonal and informational justice taking perceptions of job insecurity into account. We found informational and interpersonal justice to be associated with risk of long and frequent sickness absence independently of job insecurity and demographic variables. Results from autoregressive GEE provided some support for a causal relationship between justice perceptions and sickness absence. Contrary to expectations, we found no interaction between justice and job insecurity. Our results underline the need for fair and just treatment of employees irrespective of perceived job insecurity in order to keep the workforce healthy and to minimize lost work days due to sickness absence.

  17. The reflection seismology measurement method

    International Nuclear Information System (INIS)

    Sprecher, C.

    1987-01-01

    Even though data acquisition and data processing procedures have become more and more complex in recent decades, the end products of a reflection seismic survey have remained simple and illustrative. A seismic section resembles a geological cross-section and can be interpreted without in-depth knowledge provided that the basic principles behind the method are understood. This article attempts to convey some insight into the methodology without claiming to be scientifically exact or complete. (author)

  18. Breath acidification in adolescent runners exposed to atmospheric pollution: A prospective, repeated measures observational study

    Directory of Open Access Journals (Sweden)

    Van Sickle David

    2008-03-01

    Full Text Available Abstract Background Vigorous outdoors exercise during an episode of air pollution might cause airway inflammation. The purpose of this study was to examine the effects of vigorous outdoor exercise during peak smog season on breath pH, a biomarker of airway inflammation, in adolescent athletes. Methods We measured breath pH both pre- and post-exercise on ten days during peak smog season in 16 high school athletes engaged in daily long-distance running in a downwind suburb of Atlanta. The association of post-exercise breath pH with ambient ozone and particulate matter concentrations was tested with linear regression. Results We collected 144 pre-exercise and 146 post-exercise breath samples from 16 runners (mean age 14.9 years, 56% male. Median pre-exercise breath pH was 7.58 (interquartile range: 6.90 to 7.86 and did not change significantly after exercise. We observed no significant association between ambient ozone or particulate matter and post-exercise breath pH. However both pre- and post-exercise breath pH were strikingly low in these athletes when compared to a control sample of 14 relatively sedentary healthy adults and to published values of breath pH in healthy subjects. Conclusion Although we did not observe an acute effect of air pollution exposure during exercise on breath pH, breath pH was surprisingly low in this sample of otherwise healthy long-distance runners. We speculate that repetitive vigorous exercise may induce airway acidification.

  19. Measuring methods of matrix diffusion

    International Nuclear Information System (INIS)

    Muurinen, A.; Valkiainen, M.

    1988-03-01

    In Finland the spent nuclear fuel is planned to be disposed of at large depths in crystalline bedrock. The radionuclides which are dissolved in the groundwater may be able to diffuse into the micropores of the porous rock matrix and thus be withdrawn from the flowing water in the fractures. This phenomenon is called matrix diffusion. A review over matrix diffusion is presented in the study. The main interest is directed to the diffusion of non-sorbing species. The review covers diffusion experiments and measurements of porosity, pore size, specific surface area and water permeability

  20. Space Suit Joint Torque Measurement Method Validation

    Science.gov (United States)

    Valish, Dana; Eversley, Karina

    2012-01-01

    In 2009 and early 2010, a test method was developed and performed to quantify the torque required to manipulate joints in several existing operational and prototype space suits. This was done in an effort to develop joint torque requirements appropriate for a new Constellation Program space suit system. The same test method was levied on the Constellation space suit contractors to verify that their suit design met the requirements. However, because the original test was set up and conducted by a single test operator there was some question as to whether this method was repeatable enough to be considered a standard verification method for Constellation or other future development programs. In order to validate the method itself, a representative subset of the previous test was repeated, using the same information that would be available to space suit contractors, but set up and conducted by someone not familiar with the previous test. The resultant data was compared using graphical and statistical analysis; the results indicated a significant variance in values reported for a subset of the re-tested joints. Potential variables that could have affected the data were identified and a third round of testing was conducted in an attempt to eliminate and/or quantify the effects of these variables. The results of the third test effort will be used to determine whether or not the proposed joint torque methodology can be applied to future space suit development contracts.

  1. Intergenic and repeat transcription in human, chimpanzee and macaque brains measured by RNA-Seq.

    Directory of Open Access Journals (Sweden)

    Augix Guohua Xu

    Full Text Available Transcription is the first step connecting genetic information with an organism's phenotype. While expression of annotated genes in the human brain has been characterized extensively, our knowledge about the scope and the conservation of transcripts located outside of the known genes' boundaries is limited. Here, we use high-throughput transcriptome sequencing (RNA-Seq to characterize the total non-ribosomal transcriptome of human, chimpanzee, and rhesus macaque brain. In all species, only 20-28% of non-ribosomal transcripts correspond to annotated exons and 20-23% to introns. By contrast, transcripts originating within intronic and intergenic repetitive sequences constitute 40-48% of the total brain transcriptome. Notably, some repeat families show elevated transcription. In non-repetitive intergenic regions, we identify and characterize 1,093 distinct regions highly expressed in the human brain. These regions are conserved at the RNA expression level across primates studied and at the DNA sequence level across mammals. A large proportion of these transcripts (20% represents 3'UTR extensions of known genes and may play roles in alternative microRNA-directed regulation. Finally, we show that while transcriptome divergence between species increases with evolutionary time, intergenic transcripts show more expression differences among species and exons show less. Our results show that many yet uncharacterized evolutionary conserved transcripts exist in the human brain. Some of these transcripts may play roles in transcriptional regulation and contribute to evolution of human-specific phenotypic traits.

  2. The Repeated Administration of Resveratrol Has Measurable Effects on Circulating T-Cell Subsets in Humans

    Directory of Open Access Journals (Sweden)

    J. Luis Espinoza

    2017-01-01

    Full Text Available Preclinical studies have shown that resveratrol exerts immunomodulatory effects with potential clinical value in the amelioration of autoimmune disorders and cancer prevention; however, little is known about the in vivo effects of this naturally occurring polyphenol on human immune cells. We assessed the effects of repeated doses of resveratrol (1000 mg/day for 28 days on circulating immune cells in healthy Japanese individuals. Resveratrol was safe and well tolerated and was associated with significant increases in the numbers of circulating γδ T cells and regulatory T cells and resulted in small, yet significant, decreases in the plasma levels of the proinflammatory cytokines TNF-α and MCP-1 and a significant increase in the plasma antioxidant activity compared with the corresponding antioxidant baseline activity and with that in four control individuals. In in vitro studies, resveratrol significantly improved the growth of γδ T cells and regulatory T cells. These findings demonstrate that resveratrol has some clear biological effects on human circulating immune cells. Further studies are necessary to interpret the long-term immunological changes associated with resveratrol treatment.

  3. Narrative exposure therapy for posttraumatic stress disorder associated with repeated interpersonal trauma in patients with severe mental illness: a mixed methods design

    Directory of Open Access Journals (Sweden)

    Maria W. Mauritz

    2016-09-01

    Full Text Available Background: In the Netherlands, most patients with severe mental illness (SMI receive flexible assertive community treatment (FACT provided by multidisciplinary community mental health teams. SMI patients with comorbid posttraumatic stress disorder (PTSD are sometimes offered evidence-based trauma-focused treatment like eye movement desensitization reprocessing or prolonged exposure. There is a large amount of evidence for the effectiveness of narrative exposure therapy (NET within various vulnerable patient groups with repeated interpersonal trauma. Some FACT-teams provide NET for patients with comorbid PTSD, which is promising, but has not been specifically studied in SMI patients. Objectives: The primary aim is to evaluate NET in SMI patients with comorbid PTSD associated with repeated interpersonal trauma to get insight into whether (1 PTSD and dissociative symptoms changes and (2 changes occur in the present SMI symptoms, care needs, quality of life, global functioning, and care consumption. The second aim is to gain insight into patients’ experiences with NET and to identify influencing factors on treatment results. Methods: This study will have a mixed methods convergent design consisting of quantitative repeated measures and qualitative semi-structured in-depth interviews based on Grounded Theory. The study population will include adult SMI outpatients (n=25 with comorbid PTSD and receiving NET. The quantitative study parameters will be existence and severity of PTSD, dissociative, and SMI symptoms; care needs; quality of life; global functioning; and care consumption. In a longitudinal analysis, outcomes will be analyzed using mixed models to estimate the difference in means between baseline and repeated measurements. The qualitative study parameters will be experiences with NET and perceived factors for success or failure. Integration of quantitative and qualitative results will be focused on interpreting how qualitative results

  4. Particle measurement systems and methods

    Science.gov (United States)

    Steele, Paul T [Livermore, CA

    2011-10-04

    A system according to one embodiment includes a light source for generating light fringes; a sampling mechanism for directing a particle through the light fringes; and at least one light detector for detecting light scattered by the particle as the particle passes through the light fringes. A method according to one embodiment includes generating light fringes using a light source; directing a particle through the light fringes; and detecting light scattered by the particle as the particle passes through the light fringes using at least one light detector.

  5. Methods for measurement of durability parameters

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1996-01-01

    Present selected methods for measurement of durabilty parameters relating to chlorides, corrosion, moisture and freeze-thaw, primarly on concrete. Advantages and drawbacks of the different methods are included.......Present selected methods for measurement of durabilty parameters relating to chlorides, corrosion, moisture and freeze-thaw, primarly on concrete. Advantages and drawbacks of the different methods are included....

  6. Perspectives on repeated low-level blast and the measurement of neurotrauma in humans as an occupational exposure risk

    Science.gov (United States)

    Carr, W.; Dell, K. C.; Yanagi, M. A.; Hassan, D. M.; LoPresti, M. L.

    2017-11-01

    A pressing question in military medical research is the nature and degree of effects on the human brain from occupational repeated exposure to low-level explosive blast, but reliable and effective means to objectively measure such effects remain elusive. In survey results, headache, difficulty sleeping, irritability, cognitive impairment, and a variety of other symptoms consistent with post-concussive syndrome have been reported by those exposed to blast and there was positive correlation between degree of blast exposure and degree of symptomology, but an important goal is to obtain more objective evidence of an effect than self-report alone. This review reflects recent efforts to measure and evaluate such hypothesized effects and current recommendations for ongoing study. Optimal measures are likely those with sensitivity and specificity to systemic effects in mild neurotrauma, that have minimal to no volitional component, and that can be sampled relatively quickly with minimal intrusion in prospective, observational field studies during routine training with explosives. An understanding of an association between parameters of exposure to repeated low-level blast and negative neurologic effects would support the evaluation of clinical implications and development of protective equipment and surveillance protocols where warranted. At present, low-level blast exposure surveillance measurements do not exist as a systematic record for any professional community.

  7. Repeatable aversion across threat types is linked with life-history traits but is dependent on how aversion is measured.

    Science.gov (United States)

    Davidson, Gabrielle L; Reichert, Michael S; Crane, Jodie M S; O'Shea, William; Quinn, John L

    2018-02-01

    Personality research suggests that individual differences in risk aversion may be explained by links with life-history variation. However, few empirical studies examine whether repeatable differences in risk avoidance behaviour covary with life-history traits among individuals in natural populations, or how these links vary depending on the context and the way risk aversion is measured. We measured two different risk avoidance behaviours (latency to enter the nest and inspection time) in wild great tits ( Parus major ) in two different contexts-response to a novel object and to a predator cue placed at the nest-box during incubation---and related these behaviours to female reproductive success and condition. Females responded equally strongly to both stimuli, and although both behaviours were repeatable, they did not correlate. Latency to enter was negatively related to body condition and the number of offspring fledged. By contrast, inspection time was directly explained by whether incubating females had been flushed from the nest before the trial began. Thus, our inferences on the relationship between risk aversion and fitness depend on how risk aversion was measured. Our results highlight the limitations of drawing conclusions about the relevance of single measures of a personality trait such as risk aversion.

  8. Short-term Changes of Apparent Optical Properties in a Shallow Water Environment: Observations from Repeated Airborne Hyperspectral Measurements

    Science.gov (United States)

    Zhang, M.; English, D. C.; Hu, C.; Carlson, P. R., Jr.; Muller-Karger, F. E.; Toro-Farmer, G.; Herwitz, S. R.

    2016-02-01

    An atmospheric correction algorithm has been developed for AISA imagery over optically shallow waters in Sugarloaf Key of the Florida Keys. The AISA data were collected repeatedly during several days in May 2012, October 2012, and May 2013. A non-zero near-infrared (NIR) remote sensing reflectance (Rrs) was accounted for through iterations, based on the relationship of field-measured Rrs between the NIR and red wavelengths. Validation showed mean ratios of 0.94 to 1.002 between AISA-derived and field-measured Rrs in the blue to red wavelengths, with uncertainties generally turbidity (light attenuation) and bottom contributions. Some of these changes are larger than two times of the Rrs uncertainties from the AISA retrievals, therefore representing statistically significant changes that can be well observed from airborne measurements. The case study suggests that repeated airborne measurements may be used to study short-term changes in shallow water environments, and such a capacity may be enhanced with future geostationary satellite missions specifically designed to observe coastal ecosystems.

  9. A DESCRIPTION OF QUASAR VARIABILITY MEASURED USING REPEATED SDSS AND POSS IMAGING

    International Nuclear Information System (INIS)

    MacLeod, Chelsea L.; Ivezić, Željko; Becker, Andrew C.; Anderson, Scott F.; Sesar, Branimir; De Vries, Wim; Kochanek, Christopher S.; Kelly, Brandon C.; Lupton, Robert H.; Hall, Patrick B.; Richards, Gordon T.; Schneider, Donald P.

    2012-01-01

    We provide a quantitative description and statistical interpretation of the optical continuum variability of quasars. The Sloan Digital Sky Survey (SDSS) has obtained repeated imaging in five UV-to-IR photometric bands for 33,881 spectroscopically confirmed quasars. About 10,000 quasars have an average of 60 observations in each band obtained over a decade along Stripe 82 (S82), whereas the remaining ∼25,000 have 2-3 observations due to scan overlaps. The observed time lags span the range from a day to almost 10 years, and constrain quasar variability at rest-frame time lags of up to 4 years, and at rest-frame wavelengths from 1000 Å to 6000 Å. We publicly release a user-friendly catalog of quasars from the SDSS Data Release 7 that have been observed at least twice in SDSS or once in both SDSS and the Palomar Observatory Sky Survey, and we use it to analyze the ensemble properties of quasar variability. Based on a damped random walk (DRW) model defined by a characteristic timescale and an asymptotic variability amplitude that scale with the luminosity, black hole mass, and rest wavelength for individual quasars calibrated in S82, we can fully explain the ensemble variability statistics of the non-S82 quasars such as the exponential distribution of large magnitude changes. All available data are consistent with the DRW model as a viable description of the optical continuum variability of quasars on timescales of ∼5-2000 days in the rest frame. We use these models to predict the incidence of quasar contamination in transient surveys such as those from the Palomar Transient Factory and Large Synoptic Survey Telescope.

  10. The use of a measure of acute irritation to predict the outcome of repeated usage of hand soap products.

    Science.gov (United States)

    Williams, C; Wilkinson, M; McShane, P; Pennington, D; Fernandez, C; Pierce, S

    2011-06-01

    Healthcare-associated infection is an important worldwide problem that could be reduced by better hand hygiene practice. However, an increasing number of healthcare workers are experiencing irritant contact dermatitis of the hands as a result of repeated hand washing. This may lead to a reduced level of compliance with regard to hand hygiene. To assess whether a measure of acute irritation by hand soaps could predict the effects of repeated usage over a 2-week period. In a double-blind, randomized comparison study, the comparative irritation potential of four different hand soaps was assessed over a 24-h treatment period. The effect of repeated hand washing with the hand soap products over a 2-week period in healthy adult volunteers on skin barrier function was then determined by assessment of transepidermal water loss (TEWL), epidermal hydration and a visual assessment using the Hand Eczema Severity Index (HECSI) at days 0, 7 and 14. A total of 121 subjects from the 123 recruited completed phase 1 of the study. All four products were seen to be significantly different from each other in terms of the irritant reaction observed and all products resulted in a significantly higher irritation compared with the no-treatment control. Seventy-nine of the initial 121 subjects were then enrolled into the repeated usage study. A statistically significant worsening of the clinical condition of the skin as measured by HECSI was seen from baseline to day 14 in those subjects repeatedly washing their hands with two of the four soap products (products C and D) with P-values of 0·02 and 0·01, respectively. Subclinical assessment of the skin barrier function by measuring epidermal hydration was significantly increased from baseline to day 7 after repeated hand washing with products A, B and D but overall no significant change was seen in all four products tested by day 14. A statistically significant increase in TEWL at day 14 was seen for product A (P = 0·02) indicating a

  11. Repeated stimulation, inter-stimulus interval and inter-electrode distance alters muscle contractile properties as measured by Tensiomyography

    Science.gov (United States)

    Johnson, Mark I.; Francis, Peter

    2018-01-01

    Context The influence of methodological parameters on the measurement of muscle contractile properties using Tensiomyography (TMG) has not been published. Objective To investigate the; (1) reliability of stimulus amplitude needed to elicit maximum muscle displacement (Dm), (2) effect of changing inter-stimulus interval on Dm (using a fixed stimulus amplitude) and contraction time (Tc), (3) the effect of changing inter-electrode distance on Dm and Tc. Design Within subject, repeated measures. Participants 10 participants for each objective. Main outcome measures Dm and Tc of the rectus femoris, measured using TMG. Results The coefficient of variance (CV) and the intra-class correlation (ICC) of stimulus amplitude needed to elicit maximum Dm was 5.7% and 0.92 respectively. Dm was higher when using an inter-electrode distance of 7cm compared to 5cm [P = 0.03] and when using an inter-stimulus interval of 10s compared to 30s [P = 0.017]. Further analysis of inter-stimulus interval data, found that during 10 repeated stimuli Tc became faster after the 5th measure when compared to the second measure [P<0.05]. The 30s inter-stimulus interval produced the most stable Tc over 10 measures compared to 10s and 5s respectively. Conclusion Our data suggest that the stimulus amplitude producing maximum Dm of the rectus femoris is reliable. Inter-electrode distance and inter-stimulus interval can significantly influence Dm and/ or Tc. Our results support the use of a 30s inter-stimulus interval over 10s or 5s. Future studies should determine the influence of methodological parameters on muscle contractile properties in a range of muscles. PMID:29451885

  12. Comparing Measurement Error between Two Different Methods of Measurement of Various Magnitudes

    Science.gov (United States)

    Zavorsky, Gerald S.

    2010-01-01

    Measurement error is a common problem in several fields of research such as medicine, physiology, and exercise science. The standard deviation of repeated measurements on the same person is the measurement error. One way of presenting measurement error is called the repeatability, which is 2.77 multiplied by the within subject standard deviation.…

  13. Attrition from Web-Based Cognitive Testing: A Repeated Measures Comparison of Gamification Techniques.

    Science.gov (United States)

    Lumsden, Jim; Skinner, Andy; Coyle, David; Lawrence, Natalia; Munafo, Marcus

    2017-11-22

    The prospect of assessing cognition longitudinally and remotely is attractive to researchers, health practitioners, and pharmaceutical companies alike. However, such repeated testing regimes place a considerable burden on participants, and with cognitive tasks typically being regarded as effortful and unengaging, these studies may experience high levels of participant attrition. One potential solution is to gamify these tasks to make them more engaging: increasing participant willingness to take part and reducing attrition. However, such an approach must balance task validity with the introduction of entertaining gamelike elements. This study aims to investigate the effects of gamelike features on participant attrition using a between-subjects, longitudinal Web-based testing study. We used three variants of a common cognitive task, the Stop Signal Task (SST), with a single gamelike feature in each: one variant where points were rewarded for performing optimally; another where the task was given a graphical theme; and a third variant, which was a standard SST and served as a control condition. Participants completed four compulsory test sessions over 4 consecutive days before entering a 6-day voluntary testing period where they faced a daily decision to either drop out or continue taking part. Participants were paid for each session they completed. A total of 482 participants signed up to take part in the study, with 265 completing the requisite four consecutive test sessions. No evidence of an effect of gamification on attrition was observed. A log-rank test showed no evidence of a difference in dropout rates between task variants (χ 2 2 =3.0, P=.22), and a one-way analysis of variance of the mean number of sessions completed per participant in each variant also showed no evidence of a difference (F 2,262 =1.534, P=.21, partial η 2 =0.012). Our findings raise doubts about the ability of gamification to reduce attrition from longitudinal cognitive testing studies

  14. Direct and Repeated Clinical Measurements of pO2 for Enhancing Cancer Therapy and Other Applications.

    Science.gov (United States)

    Swartz, Harold M; Williams, Benjamin B; Hou, Huagang; Khan, Nadeem; Jarvis, Lesley A; Chen, Eunice Y; Schaner, Philip E; Ali, Arif; Gallez, Bernard; Kuppusamy, Periannan; Flood, Ann B

    2016-01-01

    The first systematic multi-center study of the clinical use of EPR oximetry has begun, with funding as a PPG from the NCI. Using particulate oxygen sensitive EPR, materials in three complementary forms (India Ink, "OxyChips", and implantable resonators) the clinical value of the technique will be evaluated. The aims include using repeated measurement of tumor pO2 to monitor the effects of treatments on tumor pO2, to use the measurements to select suitable subjects for the type of treatment including the use of hyperoxic techniques, and to provide data that will enable existing clinical techniques which provide data relevant to tumor pO2 but which cannot directly measure it to be enhanced by determining circumstances where they can give dependable information about tumor pO2.

  15. Looking back on a half century of repeat magnetic measurements in France

    Science.gov (United States)

    Alexandrescu, Mioara Mandea; Gilder, Stuart; Courtillot, Vincent; Le Mouël, Jean Louis; Gilbert, Daniel

    Birds do it. Bees do it. And with the discovery of lodestone over 2200 years ago, humans too could incorporate the Earth's magnetic field into their daily lives. Some of the oldest applications for tracking the magnetic field were in land and sea navigation. Magnetic field measurements quickly became an important economic factor in world trade, with documented use dating from the 11th century in China.The measurements are important in other applications as well. For example, rapid field variations are generated by solar activity and its interaction with the terrestrial environment. Large magnetic storms can disrupt satellite operation, communication systems, power transmission networks, and so forth [Campbell, 1997].Geomagnetism also provides a unique opportunity to explore the Earth's outer core, which is mostly liquid (molten) iron, where the field is generated. Field measurements can also yield valuable insights into the location of mineral deposits and aid in applications in the petroleum industry.

  16. Repeated stimulation, inter-stimulus interval and inter-electrode distance alters muscle contractile properties as measured by Tensiomyography.

    Directory of Open Access Journals (Sweden)

    Hannah V Wilson

    Full Text Available The influence of methodological parameters on the measurement of muscle contractile properties using Tensiomyography (TMG has not been published.To investigate the; (1 reliability of stimulus amplitude needed to elicit maximum muscle displacement (Dm, (2 effect of changing inter-stimulus interval on Dm (using a fixed stimulus amplitude and contraction time (Tc, (3 the effect of changing inter-electrode distance on Dm and Tc.Within subject, repeated measures.10 participants for each objective.Dm and Tc of the rectus femoris, measured using TMG.The coefficient of variance (CV and the intra-class correlation (ICC of stimulus amplitude needed to elicit maximum Dm was 5.7% and 0.92 respectively. Dm was higher when using an inter-electrode distance of 7cm compared to 5cm [P = 0.03] and when using an inter-stimulus interval of 10s compared to 30s [P = 0.017]. Further analysis of inter-stimulus interval data, found that during 10 repeated stimuli Tc became faster after the 5th measure when compared to the second measure [P<0.05]. The 30s inter-stimulus interval produced the most stable Tc over 10 measures compared to 10s and 5s respectively.Our data suggest that the stimulus amplitude producing maximum Dm of the rectus femoris is reliable. Inter-electrode distance and inter-stimulus interval can significantly influence Dm and/ or Tc. Our results support the use of a 30s inter-stimulus interval over 10s or 5s. Future studies should determine the influence of methodological parameters on muscle contractile properties in a range of muscles.

  17. Fixed-flexion knee radiography using a new positioning device produced highly repeatable measurements of joint space width: ELSA-Brasil Musculoskeletal Study (ELSA-Brasil MSK

    Directory of Open Access Journals (Sweden)

    Rosa Weiss Telles

    Full Text Available Abstract Objective: To describe the performance of a non-fluoroscopic fixed-flexion PA radiographic protocol with a new positioning device, developed for the assessment of knee osteoarthritis (OA in Brazilian Longitudinal Study of Adult Health Musculoskeletal Study (ELSA-Brasil MSK. Material and methods: A test–retest design including 19 adults (38 knee images was conducted. Feasibility of the radiographic protocol was assessed by image quality parameters and presence of radioanatomic alignment according to intermargin distance (IMD values. Repeatability was assessed for IMD and joint space width (JSW measured at three different locations. Results: Approximately 90% of knee images presented excellent quality. Frequencies of nearly perfect radioanatomic alignment (IMD ≤1 mm ranged from 29% to 50%, and satisfactory alignment was found in up to 71% and 76% of the images (IMD ≤1.5 mm and ≤1.7 mm, respectively. Repeatability analyses yielded the following results: IMD [SD of mean difference = 1.08; coefficient of variation (%CV = 54.68%; intraclass correlation coefficient (ICC (95%CI = 0.59 (0.34–0.77]; JSW [SD of mean difference = 0.34–0.61; %CV = 4.48%–9.80%; ICC (95%CI = 0.74 (0.55–0.85–0.94 (0.87–0.97]. Adequately reproducible measurements of IMD and JSW were found in 68% and 87% of the images, respectively. Conclusions: Despite the difficulty in achieving consistent radioanatomic alignment between subsequent radiographs in terms of IMD, the protocol produced highly repeatable JSW measurements when these were taken at midpoint and 10 mm from the medial extremity of the medial tibial plateau. Therefore, measurements of JSW at these locations can be considered adequate for the assessment of knee OA in ELSA-Brasil MSK.

  18. Multifunctional surface modification of silk fabric via graphene oxide repeatedly coating and chemical reduction method

    Science.gov (United States)

    Cao, Jiliang; Wang, Chaoxia

    2017-05-01

    Multifunctional silk fabrics with electrical conductive, anti-ultraviolet and water repellent were successfully prepared by surface modification with graphene oxide (GO). The yellow-brown GO deposited on the surface of silk fabric was converted into graphitic black reduced graphene (RGO) by sodium hydrosulfite. The surface properties of silk fabrics were changed by repeatedly RGO coating process, which have been proved by SEM and XPS. The SEM results showed that the RGO sheets were successive form a continuously thin film on the surface of silk fabrics, and the deposition of GO or RGO also can be proved by XPS. The electrical conductivity was tested by electrical surface resistance value of the silk fabric, the surface resistance decreased with increasing of RGO surface modification times, and a low surface resistance value reached to 3.24 KΩ cm-1 after 9 times of modification, indicating the silk obtained excellent conductivity. The UPF value of one time GO modification silk fabric (silk-1RGO) was enhanced significantly to 24.45 in comparison to 10.40 of original silk. The contact angle of RGO coating silk samples was all above of 120°. The durability of RGO coated silk fabrics was tested by laundering. The electrical surface resistance of silk-4RGO (65.74 KΩ cm-1), silk-6RGO (15.54 KΩ cm-1) and silk-8RGO (3.86 KΩ cm-1) fabrics was up to 86.82, 22.30 and 6.57 KΩ cm-1 after 10 times of standard washing, respectively. The UPF value, contact angle and color differences of RGO modified silk fabric slightly changed before and after 10 times of standard washing. Therefore, the washing fastness of electric conduction, anti-ultraviolet and water repellent multifunctional silk fabrics was excellent.

  19. Can You Repeat That Please?: Using Monte Carlo Simulation in Graduate Quantitative Research Methods Classes

    Science.gov (United States)

    Carsey, Thomas M.; Harden, Jeffrey J.

    2015-01-01

    Graduate students in political science come to the discipline interested in exploring important political questions, such as "What causes war?" or "What policies promote economic growth?" However, they typically do not arrive prepared to address those questions using quantitative methods. Graduate methods instructors must…

  20. Rule-of-thumb adjustment of sample sizes to accommodate dropouts in a two-stage analysis of repeated measurements.

    Science.gov (United States)

    Overall, John E; Tonidandel, Scott; Starbuck, Robert R

    2006-01-01

    Recent contributions to the statistical literature have provided elegant model-based solutions to the problem of estimating sample sizes for testing the significance of differences in mean rates of change across repeated measures in controlled longitudinal studies with differentially correlated error and missing data due to dropouts. However, the mathematical complexity and model specificity of these solutions make them generally inaccessible to most applied researchers who actually design and undertake treatment evaluation research in psychiatry. In contrast, this article relies on a simple two-stage analysis in which dropout-weighted slope coefficients fitted to the available repeated measurements for each subject separately serve as the dependent variable for a familiar ANCOVA test of significance for differences in mean rates of change. This article is about how a sample of size that is estimated or calculated to provide desired power for testing that hypothesis without considering dropouts can be adjusted appropriately to take dropouts into account. Empirical results support the conclusion that, whatever reasonable level of power would be provided by a given sample size in the absence of dropouts, essentially the same power can be realized in the presence of dropouts simply by adding to the original dropout-free sample size the number of subjects who would be expected to drop from a sample of that original size under conditions of the proposed study.

  1. Emittance measurements by variable quadrupole method

    International Nuclear Information System (INIS)

    Toprek, D.

    2005-01-01

    The beam emittance is a measure of both the beam size and beam divergence, we cannot directly measure its value. If the beam size is measured at different locations or under different focusing conditions such that different parts of the phase space ellipse will be probed by the beam size monitor, the beam emittance can be determined. An emittance measurement can be performed by different methods. Here we will consider the varying quadrupole setting method.

  2. Repeated serum creatinine measurement in primary care: Not all patients have chronic renal failure.

    Science.gov (United States)

    Gentille Lorente, Delicia; Gentille Lorente, Jorge; Salvadó Usach, Teresa

    2015-01-01

    To assess the prevalence of kidney failure in patients from a primary care centre in a basic healthcare district with laboratory availability allowing serum creatinine measurements. An observational descriptive cross-sectional study. A basic healthcare district serving 23,807 people aged ≥ 18 years. Prevalence of kidney failure among 17,240 patients having at least one laboratory measurement available was 8.5% (mean age 77.6 ± 12.05 years). In 33.2% of such patients an occult kidney failure was found (98.8% were women). Prevalence of chronic kidney failure among 10,011 patients having at least 2 laboratory measurements available (≥ 3 months apart) was 5.5% with mean age being 80.1 ± 10.0 years (most severely affected patients were those aged 75 to 84); 59.7% were men and 76.3% of cases were in stage 3. An occult kidney failure was found in 5.3% of patients with women being 86.2% of them (a glomerular filtration rate<60 ml/min was estimated for plasma creatinine levels of 0.9 mg/dl or higher). Comparison of present findings to those previously reported demonstrates the need for further studies on the prevalence of overall (chronic and acute) kidney failure in Spain in order to estimate the real scope of the disease. Primary care physicians play a critical role in disease detection, therapy, control and recording (in medical records). MDRD equation is useful and practical to estimate glomerular filtration rate. Copyright © 2015 The Authors. Published by Elsevier España, S.L.U. All rights reserved.

  3. Prognostic value of repeated serum CA 125 measurements in first trimester pregnancy.

    Science.gov (United States)

    Schmidt, T; Rein, D T; Foth, D; Eibach, H W; Kurbacher, C M; Mallmann, P; Römer, T

    2001-08-01

    To assess the diagnostic value of maternal CA 125 in patients with symptomatic first trimester pregnancy and to evaluate the prognostic significance of CA 125 versus beta-hCG in early pregnancies with intact fetal heartbeat, complicated by vaginal bleeding. Two prospective open-label studies with longitudinal follow-up in the second trial. Academic Department of Obstetrics and Gynecology, University of Cologne. Study 1: 168 patients presenting between gestational weeks 6 and 12 with: extrauterine pregnancy, 29; missed abortion, 50; incomplete spontaneous abortion, 38; imminent abortion, 33; and normal pregnancy (no history of endometriosis or ovarian mass), 18. Study 2: Fifty consecutive patients with vaginal bleeding during gestational weeks 6-12 all of whom having demostrable fetal heartbeat. Eighteen patients finally aborted whereas the remainder had normally continuing pregnancy until term. Study 1: Single serum determinations of CA 125 and beta-hCG were correlated with the different disorders observed. Study 2: Two sequential measurements of serum CA 125 and beta-hCG performed within a 5-7 days interval were related to the outcome of pregnancy as indicated by changes of the ultrasound presentation, miscarriage, future hospitalization, or delivery. Study 1: Patients with vaginal bleeding generally had higher median CA 125 values (38 IU/ml; range 1.3-540) compared to non-bleeding patients (17.8 IU/ml; range 1.0-157). No statistically significant differences in regard to median serum CA 125 levels between symptomatic and normal pregnancies occurred: normal pregnancy, 25.5 IU/ml (range 3.2-97); ectopic pregnancy, 26 IU/ml (range 1.3-157); missed abortion, 19.1IU/ml (range 1-242); threatened abortion, 48 IU/ml (range 5.2-540); spontaneous abortion, 40 IU/ml (range 5.4-442). Study 2: Initial CA 125 levels did not differ significantly between both groups of patients with 27/32 non-aborters and 13/18 aborters showing concentrations below 65 IU/ml. After 5-7 days, CA

  4. A novel typing method for Listeria monocytogenes using high-resolution melting analysis (HRMA) of tandem repeat regions.

    Science.gov (United States)

    Ohshima, Chihiro; Takahashi, Hajime; Iwakawa, Ai; Kuda, Takashi; Kimura, Bon

    2017-07-17

    Listeria monocytogenes, which is responsible for causing food poisoning known as listeriosis, infects humans and animals. Widely distributed in the environment, this bacterium is known to contaminate food products after being transmitted to factories via raw materials. To minimize the contamination of products by food pathogens, it is critical to identify and eliminate factory entry routes and pathways for the causative bacteria. High resolution melting analysis (HRMA) is a method that takes advantage of differences in DNA sequences and PCR product lengths that are reflected by the disassociation temperature. Through our research, we have developed a multiple locus variable-number tandem repeat analysis (MLVA) using HRMA as a simple and rapid method to differentiate L. monocytogenes isolates. While evaluating our developed method, the ability of MLVA-HRMA, MLVA using capillary electrophoresis, and multilocus sequence typing (MLST) was compared for their ability to discriminate between strains. The MLVA-HRMA method displayed greater discriminatory ability than MLST and MLVA using capillary electrophoresis, suggesting that the variation in the number of repeat units, along with mutations within the DNA sequence, was accurately reflected by the melting curve of HRMA. Rather than relying on DNA sequence analysis or high-resolution electrophoresis, the MLVA-HRMA method employs the same process as PCR until the analysis step, suggesting a combination of speed and simplicity. The result of MLVA-HRMA method is able to be shared between different laboratories. There are high expectations that this method will be adopted for regular inspections at food processing facilities in the near future. Copyright © 2017. Published by Elsevier B.V.

  5. Seven methods to measure ground moisture

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The correct irrigation methods are of great importance to the deciduous fruit grower. The article discusses seven methods for the measuring of ground humidity. These methods are based on gravimetry, electric resistance, gamma attenuation, neutron humidity measurement, tensiometers and a study of the correlation between ground humidity and water evaporation. At this stage, the last technique is regarded as the most practicle method. Neutron moisture gages might be used if adhered to the regulations of NUCOR

  6. Characterization of fetal growth by repeated ultrasound measurements in the wild guinea pig (Cavia aperea).

    Science.gov (United States)

    Schumann, K; Guenther, A; Göritz, F; Jewgenow, K

    2014-08-01

    Fetal growth during pregnancy has previously been studied in the domesticated guinea pig (Cavia aperea f. porcellus) after dissecting pregnant females, but there are no studies describing the fetal growth in their wild progenitor, the wild guinea pig (C aperea). In this study, 50 pregnancies of wild guinea pig sows were investigated using modern ultrasound technique. The two most common fetal growth parameters (biparietal diameter [BPD] and crown-rump-length [CRL]) and uterine position were measured. Data revealed similar fetal growth patterns in the wild guinea pig and domesticated guinea pig in the investigated gestation period, although they differ in reproductive milestones such as gestation length (average duration of pregnancy 68 days), average birth weight, and litter mass. In this study, pregnancy lasted on average 60.2 days with a variance of less than a day (0.96 days). The measured fetal growth parameters are strongly correlated with each (R = 0.91; P guinea pig. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. The effects of toluene plus noise on hearing thresholds: an evaluation based on repeated measurements in the German printing industry.

    Science.gov (United States)

    Schäper, Michael; Seeber, Andreas; van Thriel, Christoph

    2008-01-01

    The ototoxicity of occupational exposure to toluene plus noise was investigated in a longitudinal study in rotogravure printing and existing findings in the literature were evaluated. The study comprised four repeated examinations during 5 years and started with 333 male workers. Lifetime weighted average exposures (LWAE) to toluene and noise were determined from individual work histories and historic recordings; recent individual exposures were measured 10 times during the study (toluene, active sampling; noise, stationary measurements). Auditory thresholds were measured with pure tone audiometry at 0.125, 0.25, 0.5, 0.75, 1, 2, 3, 4, 6, 8, 12 kHz. Mean LWAE exposures to toluene and noise were 45+/-17 ppm plus 82+/-7 dB(A) for high toluene exposed and 10+/-7 ppm plus 82+/-4 dB(A) for low toluene exposed subjects, mean current exposures were 26+/-20 ppm plus 81+/-4 dB(A) and 3+/-3 ppm plus 82+/-4 dB(A). Mean exposure duration was 21.3+/-6.5 years for long exposed and 5.9+/-2.2 years for short exposed subjects. Repeated measurement analyses of variance did not reveal effects of toluene intensity, exposure duration and interactions between toluene intensity and noise intensity. Noise intensity [79+/-3 dB(A) vs. 84+/-1 dB(A)] was significant for auditory thresholds. A case concept utilising developments of individual auditory thresholds did not reveal significant toluene effects. Logistic models including age, exposure duration, toluene in ambient air, current noise and either hippuric acid or ortho-cresol (o-cresol) found only age to be significant for elevated OR of high frequency hearing loss. Due to missing toluene effects, it was concluded that the threshold level for developing hearing loss as a result of occupational exposure to toluene plus noise might be above the current limit of 50 ppm toluene.

  8. Repeated measurement of nasal lavage fluid chemokines in school-age children with asthma.

    Science.gov (United States)

    Noah, Terry L; Tudor, Gail E; Ivins, Sally S; Murphy, Paula C; Peden, David B; Henderson, Frederick W

    2006-02-01

    Inflammatory processes at the mucosal surface may play a role in maintenance of asthma pathophysiology. Cross-sectional studies in asthmatic patients suggest that chemokines such as interleukin 8 (IL-8) are overproduced by respiratory epithelium. To test the hypothesis that chemokine levels are persistently elevated in the respiratory secretions of asthmatic children at a stable baseline. We measured nasal lavage fluid (NLF) levels of chemokines and other mediators at 3- to 4-month intervals in a longitudinal study of asthmatic children, with nonasthmatic siblings as controls. In a linear mixed-model analysis, both family and day of visit had significant effects on nasal mediators. Thus, data for 12 asthmatic-nonasthmatic sibling pairs who had 3 or more same-day visits were analyzed separately. For sibling pairs, median eosinophil cationic protein levels derived from serial measurements in NLF were elevated in asthmatic patients compared with nonasthmatic patients, with a near-significant tendency for elevation of total protein and eotaxin levels as well. However, no significant differences were found for IL-8 or several other chemokines. Ratios of IL-13 or IL-5 to interferon-gamma released by house dust mite antigen-stimulated peripheral blood mononuclear cells, tested on a single occasion, were significantly increased for asthmatic patients. Substantial temporal and family-related variability exists in nasal inflammation in asthmatic children. Although higher levels of eosinophil cationic protein are usually present in NLF of patients with stable asthma compared with patients without asthma, chemokines other than eotaxin are not consistently increased. Eosinophil activation at the mucosal surface is a more consistent predictor of asthmatic symptoms than nonspecific elevation of epithelium-derived inflammatory chemokine levels.

  9. In situ surface roughness measurement using a laser scattering method

    Science.gov (United States)

    Tay, C. J.; Wang, S. H.; Quan, C.; Shang, H. M.

    2003-03-01

    In this paper, the design and development of an optical probe for in situ measurement of surface roughness are discussed. Based on this light scattering principle, the probe which consists of a laser diode, measuring lens and a linear photodiode array, is designed to capture the scattered light from a test surface with a relatively large scattering angle ϕ (=28°). This capability increases the measuring range and enhances repeatability of the results. The coaxial arrangement that incorporates a dual-laser beam and a constant compressed air stream renders the proposed system insensitive to movement or vibration of the test surface as well as surface conditions. Tests were conducted on workpieces which were mounted on a turning machine that operates with different cutting speeds. Test specimens which underwent different machining processes and of different surface finish were also studied. The results obtained demonstrate the feasibility of surface roughness measurement using the proposed method.

  10. Violation of the Sphericity Assumption and Its Effect on Type-I Error Rates in Repeated Measures ANOVA and Multi-Level Linear Models (MLM).

    Science.gov (United States)

    Haverkamp, Nicolas; Beauducel, André

    2017-01-01

    We investigated the effects of violations of the sphericity assumption on Type I error rates for different methodical approaches of repeated measures analysis using a simulation approach. In contrast to previous simulation studies on this topic, up to nine measurement occasions were considered. Effects of the level of inter-correlations between measurement occasions on Type I error rates were considered for the first time. Two populations with non-violation of the sphericity assumption, one with uncorrelated measurement occasions and one with moderately correlated measurement occasions, were generated. One population with violation of the sphericity assumption combines uncorrelated with highly correlated measurement occasions. A second population with violation of the sphericity assumption combines moderately correlated and highly correlated measurement occasions. From these four populations without any between-group effect or within-subject effect 5,000 random samples were drawn. Finally, the mean Type I error rates for Multilevel linear models (MLM) with an unstructured covariance matrix (MLM-UN), MLM with compound-symmetry (MLM-CS) and for repeated measures analysis of variance (rANOVA) models (without correction, with Greenhouse-Geisser-correction, and Huynh-Feldt-correction) were computed. To examine the effect of both the sample size and the number of measurement occasions, sample sizes of n = 20, 40, 60, 80, and 100 were considered as well as measurement occasions of m = 3, 6, and 9. With respect to rANOVA, the results plead for a use of rANOVA with Huynh-Feldt-correction, especially when the sphericity assumption is violated, the sample size is rather small and the number of measurement occasions is large. For MLM-UN, the results illustrate a massive progressive bias for small sample sizes ( n = 20) and m = 6 or more measurement occasions. This effect could not be found in previous simulation studies with a smaller number of measurement occasions. The

  11. Construction and updating of a public events questionnaire for repeated measures longitudinal studies

    Directory of Open Access Journals (Sweden)

    Martha eNoone

    2014-03-01

    Full Text Available Impairments of retrospective memory and cases of retrograde amnesia are often seen in clinical settings. A measure of the proportion of memories retained over a specified time can be useful in clinical situations and public events questionnaires may be valuable in this respect. However, consistency of retention of public events memory has rarely been studied in the same participants. In addition, when used in a research context, public events questionnaires require updating to ensure questions are of equivalent age with respect to when the test is taken. This paper describes an approach to constructing and updating a Public Events Questionnaire (PEQ for use with a sample that is recruited and followed-up over a long time-period. Internal consistency, parallel-form reliability, test-retest reliability and secondary validity analyses were examined for three versions of the PEQ that were updated every six months. Versions 2 and 3 of the questionnaire were reliable across and within versions and for recall and recognition. Change over time was comparable across each version of the PEQ. These results show that PEQs can be regularly updated in a standardised fashion to allow use throughout studies with long recruitment periods.

  12. Magnetic Resonance Spectroscopy in Patients with Insomnia: A Repeated Measurement Study.

    Directory of Open Access Journals (Sweden)

    Kai Spiegelhalder

    Full Text Available Chronic insomnia is one of the most prevalent central nervous system disorders. It is characterized by increased arousal levels, however, the neurobiological causes and correlates of hyperarousal in insomnia remain to be further determined. In the current study, magnetic resonance spectroscopy was used in the morning and evening in a well-characterized sample of 20 primary insomnia patients (12 females; 8 males; 42.7 ± 13.4 years and 20 healthy good sleepers (12 females; 8 males; 44.1 ± 10.6 years. The most important inhibitory and excitatory neurotransmitters of the central nervous system, γ-aminobutyric acid (GABA and glutamate/glutamine (Glx, were assessed in the anterior cingulate cortex (ACC and dorsolateral prefrontal cortex (DLPFC. The primary hypothesis, a diurnal effect on GABA levels in patients with insomnia, could not be confirmed. Moreover, the current results did not support previous findings of altered GABA levels in individuals with insomnia. Exploratory analyses, however, suggested that GABA levels in the ACC may be positively associated with habitual sleep duration, and, thus, reduced GABA levels may be a trait marker of objective sleep disturbances. Moreover, there was a significant GROUP x MEASUREMENT TIME interaction effect on Glx in the DLPFC with increasing Glx levels across the day in the patients but not in the control group. Therefore, Glx levels may reflect hyperarousal at bedtime in those with insomnia. Future confirmatory studies should include larger sample sizes to investigate brain metabolites in different subgroups of insomnia.

  13. Construction and updating of a public events questionnaire for repeated measures longitudinal studies.

    Science.gov (United States)

    Noone, Martha; Semkovska, Maria; Carton, Mary; Dunne, Ross; Horgan, John-Paul; O'Kane, Breige; McLoughlin, Declan M

    2014-01-01

    Impairments of retrospective memory and cases of retrograde amnesia are often seen in clinical settings. A measure of the proportion of memories retained over a specified time can be useful in clinical situations and public events questionnaires may be valuable in this respect. However, consistency of retention of public events memory has rarely been studied in the same participants. In addition, when used in a research context, public events questionnaires require updating to ensure questions are of equivalent age with respect to when the test is taken. This paper describes an approach to constructing and updating a Public Events Questionnaire (PEQ) for use with a sample that is recruited and followed-up over a long time-period. Internal consistency, parallel-form reliability, test-retest reliability, and secondary validity analyses were examined for three versions of the PEQ that were updated every 6 months. Versions 2 and 3 of the questionnaire were reliable across and within versions and for recall and recognition. Change over time was comparable across each version of the PEQ. These results show that PEQs can be regularly updated in a standardized fashion to allow use throughout studies with long recruitment periods.

  14. Cognitive Components Predict Virtual Reality-Induced Analgesia: Repeated Measures in Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Naor Demeter

    2018-01-01

    Full Text Available Virtual reality (VR is an advanced and useful technology in the distraction from pain. The efficacy of VR for reducing pain is well established. Yet, the literature analyzing the unique attributes of VR which impact pain reduction is scarce. The present study evaluated the effect of two VR environments on experimental pain levels. Both VR environments are games used with an EyeToy application which is part of the video capture VR family. The VR environments were analyzed by expert occupational therapists using a method of activity analysis, allowing for a thorough evaluation of the VR activity performance requirements. The VR environments were found to differ in the cognitive load (CL demands they apply upon subjects. Sixty-two healthy students underwent psychophysical thermal pain tests, followed by exposure to tonic heat stimulation under one of three conditions: Low CL (LCL VR, high CL (HCL VR, and control. In addition, following participation in VR, the subjects completed a self-feedback inventory evaluating their experience in VR. The results showed significantly greater pain reduction during both VR conditions compared to the control condition (p = 0.001. Hierarchical regression revealed cognitive components which were evaluated in the self-feedback inventory to be predictive factors for pain reduction only during the high cognitive load (HCL VR environment (20.2%. CL involved in VR may predict the extent of pain decrease, a finding that should be considered in future clinical and laboratory research.

  15. Development of systematic evaluation method on nonlinear behavior of the constructions using repeated finite element method analysis

    International Nuclear Information System (INIS)

    Kasahara, Naoto

    1997-01-01

    Supposing that the nuclear reactor stops on any reason, the temperature of flown out coolant from the reactor core will decrease and the temperature of elements touched with the coolant in the nuclear plant equipments also decreases on response to this. On the other hand, temperature pursuit at non-touched portions is delayed to form a thermal stress due to their temperature difference. In particular, a stress over its yield value at discontinuous portion of structure due to stress concentration generates, which could be thought of possibility to form a creep fatigue crack if repeating such thermal stress under high temperature. The Power Reactor and Nuclear Fuel Development Corporation has developed the transient thermal stress real time simulation code for calculating thermal stress formed within a construction in accompany with temperature changes of the coolant once and at high speed since 1994 FY, and after 1995 FY the development of FEM simulation technique from macroscopic region to microscopic region which set an objective regions from construction level to material texture has been promoted. In future, development of total simulation technique connected both and optimum design technique due to its results will be planned. (G.K.)

  16. A multi-segment foot model based on anatomically registered technical coordinate systems: method repeatability and sensitivity in pediatric planovalgus feet.

    Science.gov (United States)

    Saraswat, Prabhav; MacWilliams, Bruce A; Davis, Roy B; D'Astous, Jacques L

    2013-01-01

    Several multisegment foot models have been proposed and some have been used to study foot pathologies. These models have been tested and validated on typically developed populations; however application of such models to feet with significant deformities presents an additional set of challenges. For the first time, in this study, a multisegment foot model is tested for repeatability in a population of children with symptomatic abnormal feet. The results from this population are compared to the same metrics collected from an age matched (8-14 years) typically developing population. The modified Shriners Hospitals for Children, Greenville (mSHCG) foot model was applied to ten typically developing children and eleven children with planovalgus feet by two clinicians. Five subjects in each group were retested by both clinicians after 4-6 weeks. Both intra-clinician and inter-clinician repeatability were evaluated using static and dynamic measures. A plaster mold method was used to quantify variability arising from marker placement error. Dynamic variability was measured by examining trial differences from the same subjects when multiple clinicians carried out the data collection multiple times. For hindfoot and forefoot angles, static and dynamic variability in both groups was found to be less than 4° and 6° respectively. The mSHCG model strategy of minimal reliance on anatomical markers for dynamic measures and inherent flexibility enabled by separate anatomical and technical coordinate systems resulted in a model equally repeatable in typically developing and planovalgus populations. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Use of count-based image reconstruction to evaluate the variability and repeatability of measured standardised uptake values.

    Directory of Open Access Journals (Sweden)

    Tomohiro Kaneta

    Full Text Available Standardized uptake values (SUVs are the most widely used quantitative imaging biomarkers in PET. It is important to evaluate the variability and repeatability of measured SUVs. Phantom studies seem to be essential for this purpose; however, repetitive phantom scanning is not recommended due to the decay of radioactivity. In this study, we performed count-based image reconstruction to avoid the influence of decay using two different PET/CT scanners. By adjusting the ratio of 18F-fluorodeoxyglucose solution to tap water, a NEMA IEC body phantom was set for SUVs of 4.0 inside six hot spheres. The PET data were obtained using two scanners (Aquiduo and Celesteion; Toshiba Medical Systems, Tochigi, Japan. We set the start time for image reconstruction when the total radioactivity in the phantom was 2.53 kBq/cc, and employed the counts of the first 2-min acquisition as the standard. To maintain the number of counts for each image, we set the acquisition time for image reconstruction depending on the decay of radioactivity. We obtained 50 images, and calculated the SUVmax and SUVpeak of all six spheres in each image. The average values of the SUVmax were used to calculate the recovery coefficients to compare those measured by the two different scanners. Bland-Altman analyses of the SUVs measured by the two scanners were also performed. The measured SUVs using the two scanners exhibited a 10-30% difference, and the standard deviation (SD of the measured SUVs was between 0.1-0.2. The Celesteion always exhibited higher values than the Aquiduo. The smaller sphere exhibited a larger SD, and the SUVpeak had a smaller SD than the SUVmax. The Bland-Altman analyses showed poor agreement between the SUVs measured by the two scanners. The recovery coefficient curves obtained from the two scanners were considerably different. The Celesteion exhibited higher recovery coefficients than the Aquiduo, especially at approximately 20-mm-diameter. Additionally, the curves

  18. Handbook of nuclear safeguards measurement methods

    International Nuclear Information System (INIS)

    Rogers, D.R.

    1983-09-01

    This handbook is intended to be a guide to the selection of methods for meeting specific measurement requirements. The information was compiled from a survey of production facilities, the literature, and current exchange programs. The survey included bulk measurements, chemical assay, sampling techniques, isotopic measurements, passive NDA, and active NDA

  19. Creating multithemed ecological regions for macroscale ecology: Testing a flexible, repeatable, and accessible clustering method

    Science.gov (United States)

    Cheruvelil, Kendra Spence; Yuan, Shuai; Webster, Katherine E.; Tan, Pang-Ning; Lapierre, Jean-Francois; Collins, Sarah M.; Fergus, C. Emi; Scott, Caren E.; Norton Henry, Emily; Soranno, Patricia A.; Filstrup, Christopher T.; Wagner, Tyler

    2017-01-01

    Understanding broad-scale ecological patterns and processes often involves accounting for regional-scale heterogeneity. A common way to do so is to include ecological regions in sampling schemes and empirical models. However, most existing ecological regions were developed for specific purposes, using a limited set of geospatial features and irreproducible methods. Our study purpose was to: (1) describe a method that takes advantage of recent computational advances and increased availability of regional and global data sets to create customizable and reproducible ecological regions, (2) make this algorithm available for use and modification by others studying different ecosystems, variables of interest, study extents, and macroscale ecology research questions, and (3) demonstrate the power of this approach for the research question—How well do these regions capture regional-scale variation in lake water quality? To achieve our purpose we: (1) used a spatially constrained spectral clustering algorithm that balances geospatial homogeneity and region contiguity to create ecological regions using multiple terrestrial, climatic, and freshwater geospatial data for 17 northeastern U.S. states (~1,800,000 km2); (2) identified which of the 52 geospatial features were most influential in creating the resulting 100 regions; and (3) tested the ability of these ecological regions to capture regional variation in water nutrients and clarity for ~6,000 lakes. We found that: (1) a combination of terrestrial, climatic, and freshwater geospatial features influenced region creation, suggesting that the oft-ignored freshwater landscape provides novel information on landscape variability not captured by traditionally used climate and terrestrial metrics; and (2) the delineated regions captured macroscale heterogeneity in ecosystem properties not included in region delineation—approximately 40% of the variation in total phosphorus and water clarity among lakes was at the regional

  20. Measuring method for optical fibre sensors

    NARCIS (Netherlands)

    Lammerink, Theodorus S.J.; Fluitman, J.H.J.

    1984-01-01

    A new measuring method for the signal amplitude in intensity modulating fibre optic sensors is described. A reference signal is generated in the time domain. The method is insensitive for the sensitivity fluctuations of the light transmitter and the light receiver. The method is experimentally

  1. Determining Criteria to Predict Repeatability of Performance in Older Adults: Using Coefficients of Variation for Strength and Functional Measures.

    Science.gov (United States)

    Raj, Isaac Selva; Bird, Stephen R; Westfold, Ben A; Shield, Anthony J

    2017-01-01

    Reliable measures of muscle strength and functional capacity in older adults are essential. The aim of this study was to determine whether coefficients of variation (CVs) of individuals obtained at the first session can infer repeatability of performance in a subsequent session. Forty-eight healthy older adults (mean age 68.6 ± 6.1 years; age range 60-80 years) completed two assessment sessions, and on each occasion undertook: dynamometry for isometric and isokinetic quadriceps strength, 6 meter fast walk (6MFWT), timed up and go (TUG), stair climb and descent, and vertical jump. Significant linear relationships were observed between CVs in session 1 and the percentage difference between sessions 1 and 2 for torque at 60, 120, 240 and 360°/s, 6MFWT, TUG, stair climb, and stair descent. The results of this study could be used to establish criteria for determining an acceptably reliable performance in strength and functional tests.

  2. Brachial artery responses to ambient pollution, temperature, and humidity in people with type 2 diabetes: a repeated-measures study.

    Science.gov (United States)

    Zanobetti, Antonella; Luttmann-Gibson, Heike; Horton, Edward S; Cohen, Allison; Coull, Brent A; Hoffmann, Barbara; Schwartz, Joel D; Mittleman, Murray A; Li, Yongsheng; Stone, Peter H; de Souza, Celine; Lamparello, Brooke; Koutrakis, Petros; Gold, Diane R

    2014-03-01

    Extreme weather and air pollution are associated with increased cardiovascular risk in people with diabetes. In a population with diabetes, we conducted a novel assessment of vascular brachial artery responses both to ambient pollution and to weather (temperature and water vapor pressure, a measure of humidity). Sixty-four 49- to 85-year-old Boston residents with type 2 diabetes completed up to five study visits (279 repeated measures). Brachial artery diameter (BAD) was measured by ultrasound before and after brachial artery occlusion [i.e., flow-mediated dilation (FMD)] and before and after nitroglycerin-mediated dilation (NMD). Ambient concentrations of fine particulate mass (PM2.5), black carbon (BC), organic carbon (OC), elemental carbon, particle number, and sulfate were measured at our monitoring site; ambient concentrations of carbon monoxide, nitrogen dioxide, and ozone were obtained from state monitors. Particle exposure in the home and during each trip to the clinic (home/trip exposure) was measured continuously and as a 5-day integrated sample. We used linear models with fixed effects for participants, adjusting for date, season, temperature, and water vapor pressure on the day of each visit, to estimate associations between our outcomes and interquartile range increases in exposure. Baseline BAD was negatively associated with particle pollution, including home/trip-integrated BC (-0.02 mm; 95% CI: -0.04, -0.003, for a 0.28 μg/m3 increase in BC), OC (-0.08 mm; 95% CI: -0.14, -0.03, for a 1.61 μg/m3 increase) as well as PM2.5, 5-day average ambient PM2.5, and BC. BAD was positively associated with ambient temperature and water vapor pressure. However, exposures were not consistently associated with FMD or NMD. Brachial artery diameter, a predictor of cardiovascular risk, decreased in association with particle pollution and increased in association with ambient temperature in our study population of adults with type 2 diabetes. Zanobetti A, Luttmann

  3. Methods of measuring residual stresses in components

    International Nuclear Information System (INIS)

    Rossini, N.S.; Dassisti, M.; Benyounis, K.Y.; Olabi, A.G.

    2012-01-01

    Highlights: ► Defining the different methods of measuring residual stresses in manufactured components. ► Comprehensive study on the hole drilling, neutron diffraction and other techniques. ► Evaluating advantage and disadvantage of each method. ► Advising the reader with the appropriate method to use. -- Abstract: Residual stresses occur in many manufactured structures and components. Large number of investigations have been carried out to study this phenomenon and its effect on the mechanical characteristics of these components. Over the years, different methods have been developed to measure residual stress for different types of components in order to obtain reliable assessment. The various specific methods have evolved over several decades and their practical applications have greatly benefited from the development of complementary technologies, notably in material cutting, full-field deformation measurement techniques, numerical methods and computing power. These complementary technologies have stimulated advances not only in measurement accuracy and reliability, but also in range of application; much greater detail in residual stresses measurement is now available. This paper aims to classify the different residual stresses measurement methods and to provide an overview of some of the recent advances in this area to help researchers on selecting their techniques among destructive, semi destructive and non-destructive techniques depends on their application and the availabilities of those techniques. For each method scope, physical limitation, advantages and disadvantages are summarized. In the end this paper indicates some promising directions for future developments.

  4. Measuring methods for the TFR plasma diagnostics

    International Nuclear Information System (INIS)

    Etievant, C.

    1975-02-01

    The measuring methods in operation or still under development for the diagnostics of the TFR plasma parameters (ion and electron temperatures, electron density, current density are reviewed, the diagnostics of the electrical behavior of the discharge, the neutral gas densities, the impurities and the parameters of the plasma turbulence being also investigated. Actual works are principally devoted to: improving ion temperature measurements by the possible use of the Doppler effect or infra-red incoherent scattering; improving n(e) and T(e) measurement by Thomson scattering; measuring the poloidal field and current density; measuring impurities by X and UV spectroscopy and measuring instabilities and turbulence [fr

  5. Photogrammetric methods of measurement in industrial applications

    International Nuclear Information System (INIS)

    Godding, R.; Groene, A.; Heinrich, G.; Schneider, C.T.

    1993-01-01

    Methods for 3D measurement are required for very varied applications in the industrial field. This includes tasks of quality assurance and plant monitoring, among others. It should be possible to apply the process flexibly it should require as short interruptions of production as possible and should meet the required accuracies. These requirements can be met by photogrammetric methods of measurement. The article introduces these methods and shows their capabilities from various selected examples (eg: the replacement of large components in a pressurized water reactor, and aircraft measurements (orig./DG) [de

  6. Residual gravimetric method to measure nebulizer output.

    Science.gov (United States)

    Vecellio None, Laurent; Grimbert, Daniel; Bordenave, Joelle; Benoit, Guy; Furet, Yves; Fauroux, Brigitte; Boissinot, Eric; De Monte, Michele; Lemarié, Etienne; Diot, Patrice

    2004-01-01

    The aim of this study was to assess a residual gravimetric method based on weighing dry filters to measure the aerosol output of nebulizers. This residual gravimetric method was compared to assay methods based on spectrophotometric measurement of terbutaline (Bricanyl, Astra Zeneca, France), high-performance liquid chromatography (HPLC) measurement of tobramycin (Tobi, Chiron, U.S.A.), and electrochemical measurements of NaF (as defined by the European standard). Two breath-enhanced jet nebulizers, one standard jet nebulizer, and one ultrasonic nebulizer were tested. Output produced by the residual gravimetric method was calculated by weighing the filters both before and after aerosol collection and by filter drying corrected by the proportion of drug contained in total solute mass. Output produced by the electrochemical, spectrophotometric, and HPLC methods was determined after assaying the drug extraction filter. The results demonstrated a strong correlation between the residual gravimetric method (x axis) and assay methods (y axis) in terms of drug mass output (y = 1.00 x -0.02, r(2) = 0.99, n = 27). We conclude that a residual gravimetric method based on dry filters, when validated for a particular agent, is an accurate way of measuring aerosol output.

  7. Measurement methods for several properties of scintillator

    International Nuclear Information System (INIS)

    Luo Fengqun; Ji Changsong

    1998-01-01

    The current paper describes the experimental measurement methods for the relative light output, the relative energy conversion efficiency, the intrinsic amplitude resolution and the detection efficiency of the scintillators and their temperature effects

  8. Absolute measurement method of environment radon content

    International Nuclear Information System (INIS)

    Ji Changsong

    1989-11-01

    A portable environment radon content device with a 40 liter decay chamber based on the method of Thomas double filter radon content absolute measurement has been developed. The correctness of the method of Thomas double filter absolute measurement has been verified by the experiments to measure the sampling gas density of radon that the theoretical density has been known. In addition, the intrinsic uncertainty of this method is also determined in the experiments. The confidence of this device is about 95%, the sensitivity is better than 0.37 Bqm -3 and the intrinsic uncertainty is less than 10%. The results show that the selected measuring and structure parameters are reasonable and the experimental methods are acceptable. In this method, the influence on the measured values from the radioactive equilibrium of radon and its daughters, the ratio of combination daughters to the total daughters and the fraction of charged particles has been excluded in the theory and experimental methods. The formula of Thomas double filter absolute measuring radon is applicable to the cylinder decay chamber, and the applicability is also verified when the diameter of exit filter is much smaller than the diameter of inlet filter

  9. Noise thermometry - a new temperature measuring method

    International Nuclear Information System (INIS)

    Brixy, H.; Hecker, R.; Rittinghaus, K.F.

    1975-01-01

    The thermal Johnson-Niquist noise is the basis of noise thermometry. This temperature measuring method is, e.g., of interest insofar as the noise thermometer gives absolute values as a primary thermometer and is in principle extensively independent of environmental influences and material properties. The resistance values of the measuring probe are about 10 Ohm to a few kOhm. The demands of electronics are high, the self-noise of the measuring apparatus must be as small as possible; a comparative measuring method is advantageous. 1 to 2,500 K are given as a possible temperature range. An accuracy of 0.1% could be achieved in laboratory measurements. Temperature measurements to be used in operation in a few nuclear reactors are mentioned. (HP/LH) [de

  10. A new method to measure vaginal sensibility

    NARCIS (Netherlands)

    Lakeman, M. M. E.; Laan, E.; Vaart, C. H.; Roovers, J. P.

    2010-01-01

    Vaginal surgery may affect sexual function both positively and negatively. Possibly, negative consequences of surgical interventions on sexuality may be caused by reduced sensibility of the vaginal wall. To develop a new method to measure vaginal sensibility. We developed a technique to measure the

  11. Palpatory method of measuring diastolic blood pressure

    Directory of Open Access Journals (Sweden)

    Dinesh Sahu

    2010-01-01

    Conclusion: The palpatory method would be very useful where frequent blood pressure measurement are being done manually like in wards, in busy OPD, patient on treadmill and also whenever stethoscope is not available. The blood pressure can be measured in noisy environment too.

  12. Improved method of measurement for outer leak

    International Nuclear Information System (INIS)

    Xu Guang

    2012-01-01

    Pneumatic pipeline is installed for the airborne radioactivity measurement equipment, air tightness and outer leak rate are essential for the testing of the characteristics, both in the national criteria and ISO standards, an improved practical method is available for the measurement of the outer air leak rate based on the engineering experiences for the equipment acceptance and testing procedure. (authors)

  13. Development of a Tandem Repeat-Based Polymerase Chain Displacement Reaction Method for Highly Sensitive Detection of 'Candidatus Liberibacter asiaticus'.

    Science.gov (United States)

    Lou, Binghai; Song, Yaqin; RoyChowdhury, Moytri; Deng, Chongling; Niu, Ying; Fan, Qijun; Tang, Yan; Zhou, Changyong

    2018-02-01

    Huanglongbing (HLB) is one of the most destructive diseases in citrus production worldwide. Early detection of HLB pathogens can facilitate timely removal of infected citrus trees in the field. However, low titer and uneven distribution of HLB pathogens in host plants make reliable detection challenging. Therefore, the development of effective detection methods with high sensitivity is imperative. This study reports the development of a novel method, tandem repeat-based polymerase chain displacement reaction (TR-PCDR), for the detection of 'Candidatus Liberibacter asiaticus', a widely distributed HLB-associated bacterium. A uniquely designed primer set (TR2-PCDR-F/TR2-PCDR-1R) and a thermostable Taq DNA polymerase mutant with strand displacement activity were used for TR-PCDR amplification. Performed in a regular thermal cycler, TR-PCDR could produce more than two amplicons after each amplification cycle. Sensitivity of the developed TR-PCDR was 10 copies of target DNA fragment. The sensitive level was proven to be 100× higher than conventional PCR and similar to real-time PCR. Data from the detection of 'Ca. L. asiaticus' with filed samples using the above three methods also showed similar results. No false-positive TR-PCDR amplification was observed from healthy citrus samples and water controls. These results thereby illustrated that the developed TR-PCDR method can be applied to the reliable, highly sensitive, and cost-effective detection of 'Ca. L. asiaticus'.

  14. Accuracy and repeatability of quantitative fluoroscopy for the measurement of sagittal plane translation and finite centre of rotation in the lumbar spine.

    Science.gov (United States)

    Breen, Alexander; Breen, Alan

    2016-07-01

    Quantitative fluoroscopy (QF) was developed to measure intervertebral mechanics in vivo and has been found to have high repeatability and accuracy for the measurement of intervertebral rotations. However, sagittal plane translation and finite centre of rotation (FCR) are potential measures of stability but have not yet been fully validated for current QF. This study investigated the repeatability and accuracy of QF for measuring these variables. Repeatability was assessed from L2-S1 in 20 human volunteers. Accuracy was investigated using 10 consecutive measurements from each of two pairs of linked and instrumented dry human vertebrae as reference; one which tilted without translation and one which translated without tilt. The results found intra- and inter-observer repeatability for translation to be 1.1mm or less (SEM) with fair to substantial reliability (ICC 0.533-0.998). Intra-observer repeatability of FCR location for inter-vertebral rotations of 5° and above ranged from 1.5mm to 1.8mm (SEM) with moderate to substantial reliability (ICC 0.626-0.988). Inter-observer repeatability for FCR ranged from 1.2mm to 5.7mm, also with moderate to substantial reliability (ICC 0.621-0.878). Reliability was substantial (ICC>0.81) for 10/16 measures for translation and 5/8 for FCR location. Accuracy for translation was 0.1mm (fixed centre) and 2.2mm (moveable centre), with an FCR error of 0.3mm(x) and 0.4mm(y) (fixed centre). This technology was found to have a high level of accuracy and with a few exceptions, moderate to substantial repeatability for the measurement of translation and FCR from fluoroscopic motion sequences. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  15. A New Method to Measure Vaginal Sensibility

    NARCIS (Netherlands)

    Lakeman, M. M. E.; Laan, E.; Vaart, C. H.; Roovers, J. P.

    2010-01-01

    Introduction: Vaginal surgery may affect sexual function both positively and negatively. Possibly, negative consequences of surgical interventions on sexuality may be caused by reduced sensibility of the vaginal wall. Aims: To develop a new method to measure vaginal sensibility. Methods: We

  16. Torsion method for measuring piezooptic coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Skab, I.; Smaga, I.; Savaryn, V.; Vasylkiv, Yu.; Vlokh, R. [Institute of Physical Optics, Lviv (Ukraine)

    2011-01-15

    We develop and describe analytically a torsion method for measuring piezooptic coefficients associated with shear stresses. It is shown that the method enables to increase significantly the accuracy of determination of piezooptic coefficients. The method and the appropriate apparatus are verified experimentally on the example of LiNbO{sub 3} crystals. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Methods of radon measurement and devices

    International Nuclear Information System (INIS)

    Miles, J.

    2004-01-01

    The following topics and instrumentation are discussed: The quantity to be measured; Active measurement methods (scintillation cells, ionisation chambers, electrostatic collection of decay products); Passive measurement methods (charcoal detectors; electret ion chambers; etched track detectors); and Detector considerations for large-scale surveys ('always on' or 'switchable' detectors?; response to radon-220; avoidance of electrostatic effects; quality assurance for passive radon detectors; quality control within the laboratory; external quality assurance; detectors need to be easily deliverable). It is concluded that the ideal detector for large scale surveys of radon in houses is a small, closed detector in a conducting holder which excludes radon-220, supported by rigorous quality assurance procedures. (P.A.)

  18. Absolute method of measuring magnetic susceptibility

    Science.gov (United States)

    Thorpe, A.; Senftle, F.E.

    1959-01-01

    An absolute method of standardization and measurement of the magnetic susceptibility of small samples is presented which can be applied to most techniques based on the Faraday method. The fact that the susceptibility is a function of the area under the curve of sample displacement versus distance of the magnet from the sample, offers a simple method of measuring the susceptibility without recourse to a standard sample. Typical results on a few substances are compared with reported values, and an error of less than 2% can be achieved. ?? 1959 The American Institute of Physics.

  19. Method of orthogonally splitting imaging pose measurement

    Science.gov (United States)

    Zhao, Na; Sun, Changku; Wang, Peng; Yang, Qian; Liu, Xintong

    2018-01-01

    In order to meet the aviation's and machinery manufacturing's pose measurement need of high precision, fast speed and wide measurement range, and to resolve the contradiction between measurement range and resolution of vision sensor, this paper proposes an orthogonally splitting imaging pose measurement method. This paper designs and realizes an orthogonally splitting imaging vision sensor and establishes a pose measurement system. The vision sensor consists of one imaging lens, a beam splitter prism, cylindrical lenses and dual linear CCD. Dual linear CCD respectively acquire one dimensional image coordinate data of the target point, and two data can restore the two dimensional image coordinates of the target point. According to the characteristics of imaging system, this paper establishes the nonlinear distortion model to correct distortion. Based on cross ratio invariability, polynomial equation is established and solved by the least square fitting method. After completing distortion correction, this paper establishes the measurement mathematical model of vision sensor, and determines intrinsic parameters to calibrate. An array of feature points for calibration is built by placing a planar target in any different positions for a few times. An terative optimization method is presented to solve the parameters of model. The experimental results show that the field angle is 52 °, the focus distance is 27.40 mm, image resolution is 5185×5117 pixels, displacement measurement error is less than 0.1mm, and rotation angle measurement error is less than 0.15°. The method of orthogonally splitting imaging pose measurement can satisfy the pose measurement requirement of high precision, fast speed and wide measurement range.

  20. COMPANY PERFORMANCE MEASUREMENT AND REPORTING METHODS

    Directory of Open Access Journals (Sweden)

    Nicu Ioana Elena

    2012-12-01

    Full Text Available One of the priorities of economic research has been and remains the re-evaluation of the notion of performance and especially exploring and finding some indicators that would reflect as accurately as possible the subtleties of the economic entity. The main purpose of this paper is to highlight the main company performance measurement and reporting methods. Performance is a concept that raises many question marks concerning the most accurate or the best method of reporting the performance at the company level. The research methodology has aimed at studying the Romanian and foreign specialized literature dealing with the analyzed field, studying magazines specialized on company performance measurement. If the financial performance measurement indicators are considered to offer an accurate image of the situation of the company, the modern approach through non-financial indicators offers a new perspective upon performance measurement, which is based on simplicity. In conclusion, after the theoretical study, I have noticed that the methods of performance measurement, reporting and interpretation are various, the opinions regarding the best performance measurement methods are contradictive and the companies prefer resorting to financial indicators that still play a more important role in the consolidation of the company performance measurement than the non-financial indicators do.

  1. Repeated measurements of cerebral blood flow in the left superior temporal gyrus reveal tonic hyperactivity in patients with auditory verbal hallucinations: A possible trait marker

    Directory of Open Access Journals (Sweden)

    Philipp eHoman

    2013-06-01

    Full Text Available Background: The left superior temporal gyrus (STG has been suggested to play a key role in auditory verbal hallucinations in patients with schizophrenia. Methods: Eleven medicated subjects with schizophrenia and medication-resistant auditory verbal hallucinations and 19 healthy controls underwent perfusion magnetic resonance imaging with arterial spin labeling. Three additional repeated measurements were conducted in the patients. Patients underwent a treatment with transcranial magnetic stimulation (TMS between the first 2 measurements. The main outcome measure was the pooled cerebral blood flow (CBF, which consisted of the regional CBF measurement in the left superior temporal gyrus (STG and the global CBF measurement in the whole brain.Results: Regional CBF in the left STG in patients was significantly higher compared to controls (p < 0.0001 and to the global CBF in patients (p < 0.004 at baseline. Regional CBF in the left STG remained significantly increased compared to the global CBF in patients across time (p < 0.0007, and it remained increased in patients after TMS compared to the baseline CBF in controls (p < 0.0001. After TMS, PANSS (p = 0.003 and PSYRATS (p = 0.01 scores decreased significantly in patients.Conclusions: This study demonstrated tonically increased regional CBF in the left STG in patients with schizophrenia and auditory hallucinations despite a decrease in symptoms after TMS. These findings were consistent with what has previously been termed a trait marker of auditory verbal hallucinations in schizophrenia.

  2. Track detection methods of radium measurements

    International Nuclear Information System (INIS)

    Somogyi, G.

    1986-06-01

    The principles of tack formation and processing including the description of etching and etch-track evaluation for the preferably used plastic track detectors are discussed. Measuring methods to determine 226 Ra activity based either on the mapping of alpha-decaying elements in the complete U-Ra series by alpha-radiography, or on the measurement of uranium alone by neutron induced fissionography, or on the alpha-decay measurement of 222 Rn, the first daughter element of radium, and finally on the measurement of alpha-tracks originating from radium itself, which is separated from its parent nuclides are described in detail. (V.N.)

  3. Test–retest repeatability of quantitative cardiac 11C-meta-hydroxyephedrine measurements in rats by small animal positron emission tomography

    International Nuclear Information System (INIS)

    Thackeray, James T.; Renaud, Jennifer M.; Kordos, Myra; Klein, Ran; Kemp, Robert A. de; Beanlands, Rob S.B.; DaSilva, Jean N.

    2013-01-01

    Introduction: The norepinephrine analogue 11 C-meta-hydroxyephedrine (HED) has been used to interrogate sympathetic neuronal reuptake in cardiovascular disease. Application for longitudinal studies in small animal models of disease necessitates an understanding of test–retest variability. This study evaluated the repeatability of multiple quantitative cardiac measurements of HED retention and washout and the pharmacological response to reuptake blockade and enhanced norepinephrine levels. Methods: Small animal PET images were acquired over 60 min following HED administration to healthy male Sprague Dawley rats. Paired test and retest scans were undertaken in individual animals over 7 days. Additional HED scans were conducted following administration of norepinephrine reuptake inhibitor desipramine or continuous infusion of exogenous norepinephrine. HED retention was quantified by retention index, standardized uptake value (SUV), monoexponential and one-compartment washout. Plasma and cardiac norepinephrine were measured by high performance liquid chromatography. Results: Test retest variability was lower for retention index (15% ± 12%) and SUV (19% ± 15%) as compared to monoexponential washout rates (21% ± 13%). Desipramine pretreatment reduced myocardial HED retention index by 69% and SUV by 85%. Chase treatment with desipramine increased monoexponential HED washout by 197% compared to untreated controls. Norepinephrine infusion dose-dependently reduced HED accumulation, reflected by both retention index and SUV, with a corresponding increase in monoexponential washout. Plasma and cardiac norepinephrine levels correlated with HED quantitative measurements. Conclusion: The repeatability of HED retention index, SUV, and monoexponential washout supports its suitability for longitudinal PET studies in rats. Uptake and washout of HED are sensitive to acute increases in norepinephrine concentration

  4. Methods of viscosity measurements in sealed ampoules

    Science.gov (United States)

    Mazuruk, Konstantin

    1999-07-01

    Viscosity of semiconductors and metallic melts is usually measured by oscillating cup method. This method utilizes the melts contained in vacuum sealed silica ampoules, thus the problems related to volatility, contamination, and high temperature and pressure can be alleviate. In a typical design, the time required for a single measurement is of the order of one hour. In order to reduce this time to a minute range, a high resolution angular detection system is implemented in our design of the viscometer. Furthermore, an electromagnet generating a rotational magnetic field (RMF) is incorporated into the apparatus. This magnetic field can be used to remotely and nonintrusively measure the electrical conductivity of the melt. It can also be used to induce a well controlled rotational flow in the system. The transient behavior of this flow can potentially yield of the fluid. Based on RMF implementation, two novel viscometry methods are proposed in this work: a) the transient torque method, b) the resonance method. A unified theoretical approach to the three methods is presented along with the initial test result of the constructed apparatus. Advantages of each of the method are discussed.

  5. Human performance assessment: methods and measures

    International Nuclear Information System (INIS)

    Andresen, Gisle; Droeivoldsmo, Asgeir

    2000-10-01

    The Human Error Analysis Project (HEAP) was initiated in 1994. The aim of the project was to acquire insights on how and why cognitive errors occur when operators are engaged in problem solving in advanced integrated control rooms. Since human error had not been studied in the HAlden Man-Machine LABoratory (HAMMLAB) before, it was also necessary to carry out research in methodology. In retrospect, it is clear that much of the methodological work is relevant to human-machine research in general, and not only to research on human error. The purpose of this report is, therefore, to give practitioners and researchers an overview of the methodological parts of HEAP. The scope of the report is limited to methods used throughout the data acquisition process, i.e., data-collection methods, data-refinement methods, and measurement methods. The data-collection methods include various types of verbal protocols, simulator logs, questionnaires, and interviews. Data-refinement methods involve different applications of the Eyecon system, a flexible data-refinement tool, and small computer programs used for rearranging, reformatting, and aggregating raw-data. Measurement methods involve assessment of diagnostic behaviour, erroneous actions, complexity, task/system performance, situation awareness, and workload. The report concludes that the data-collection methods are generally both reliable and efficient. The data-refinement methods, however, should be easier to use in order to facilitate explorative analyses. Although the series of experiments provided an opportunity for measurement validation, there are still uncertainties connected to several measures, due to their reliability still being unknown. (Author). 58 refs.,7 tabs

  6. The variability of piezoelectric measurements. Material and measurement method contributions

    International Nuclear Information System (INIS)

    Stewart, M.; Cain, M.

    2002-01-01

    The variability of piezoelectric materials measurements has been investigated in order to separate the contributions from intrinsic instrumental variability, and the contributions from the variability in materials. The work has pinpointed several areas where weaknesses in the measurement methods result in high variability, and also show that good correlation between piezoelectric parameters allow simpler measurement methods to be used. The Berlincourt method has been shown to be unreliable when testing thin discs, however when testing thicker samples there is a good correlation between this and other methods. The high field permittivity and low field permittivity correlate well, so tolerances on low field measurements would predict high field performance. In trying to identify microstructural origins of samples that behave differently to others within a batch, no direct evidence was found to suggest that outliers originate from either differences in microstructure or crystallography. Some of the samples chosen as maximum outliers showed pin-holes, probably from electrical breakdown during poling, even though these defects would ordinarily be detrimental to piezoelectric output. (author)

  7. Predictive value of repeated measurements of luteal progesterone and estradiol levels in patients with intrauterine insemination and controlled ovarian stimulation.

    Science.gov (United States)

    Bakas, Panagiotis; Simopoulou, Maria; Giner, Maria; Drakakis, Petros; Panagopoulos, Perikles; Vlahos, Nikolaos

    2017-10-01

    The objective of this study is to assess if the difference of repeated measurements of estradiol and progesterone during luteal phase predict the outcome of intrauterine insemination. Prospective study. Reproductive clinic. 126 patients with infertility. Patients underwent controlled ovarian stimulation with recombinant FSH (50-150 IU/d). The day of IUI patients were given p.o natural micronized progesterone in a dose of 100 mg/tds. The area under the receiver characteristic operating curve (ROC curve) in predicting clinical pregnancy for % change of estradiol level on days 6 and 10 was 0.892 with 95% CI: 0.82-0.94. A cutoff value of change > -29.5% had a sensitivity of 85.7 with a specificity of 90.2. The corresponding ROC curve for % change of progesterone level was 0.839 with 95% CI: 0.76-0.90. A cutoff value of change > -33% had a sensitivity of 85 with a specificity of 75. The % change of estradiol and progesterone between days 6 and 10 has a predictive ability of pregnancy after IUI with COS of 89.2% and 83.4%, respectively. The addition of % of progesterone to % change of estradiol does not improve the predictive ability of % estradiol and should not be used.

  8. Very long Detection Times after High and repeated intake of Heroin and Methadone, measured in Oral Fluid

    Directory of Open Access Journals (Sweden)

    Vindenes V.

    2014-12-01

    Full Text Available When detection times for psychoactive drugs in oral fluid are reported, they are most often based on therapeutic doses administered in clinical studies. Repeated ingestions of high doses, as seen after drug abuse, are however likely to cause positive samples for extended time periods. Findings of drugs of abuse in oral fluid might lead to negative sanctions, and the knowledge of detection times of these drugs are important to ensure correct interpretation. The aim of this study was to investigate the detection times of opioids in oral fluid. 25 patients with a history of heavy drug abuse admitted to a detoxification ward were included. Oral fluid and urine were collected daily and, if the patient gave consent, a blood sample was drawn during the first five days after admission. Morphine, codeine and/or 6-monoacetyl morphine (6-MAM were found in oral fluid and/or urine from 20 patients. The maximum detection times in oral fluid for codeine, morphine and 6-MAM were 1, 3 and 8 days, respectively. Positive oral fluid samples were interspersed with negative samples, mainly for concentrations around cut off. Elimination curves for methadone in oral fluid were found for two subjects, and the detection times were 5 and 8 days. Oral fluid is likely to become a good method for detection of drug abuse in the future

  9. Methods and Devices used to Measure Friction

    DEFF Research Database (Denmark)

    Jeswiet, Jack; Arentoft, Mogens; Henningsen, Poul

    2004-01-01

    . To gain a good understanding of the mechanisms at the interface and to be able to verify the friction and tribology models that exist, friction sensors are needed. Designing sensors to measure friction-stress in metal working has been pursued by many researchers. This paper surveys methods, which have...... been tried in the past and discusses some of the recent sensor designs, which can now be used to measure Friction in both production situations and for research purposes....

  10. Three methods to measure RH bond energies

    International Nuclear Information System (INIS)

    Berkowitz, J.; Ellison, G.B.; Gutman, D.

    1993-01-01

    In this paper the authors compare and contrast three powerful methods for experimentally measuring bond energies in polyatomic molecules. The methods are: radical kinetics; gas phase acidity cycles; and photoionization mass spectroscopy. The knowledge of the values of bond energies are a basic piece of information to a chemist. Chemical reactions involve the making and breaking of chemical bonds. It has been shown that comparable bonds in polyatomic molecules, compared to the same bonds in radicals, can be significantly different. These bond energies can be measured in terms of bond dissociation energies

  11. Statistical methods towards more efficient infiltration measurements.

    Science.gov (United States)

    Franz, T; Krebs, P

    2006-01-01

    A comprehensive knowledge about the infiltration situation in a catchment is required for operation and maintenance. Due to the high expenditures, an optimisation of necessary measurement campaigns is essential. Methods based on multivariate statistics were developed to improve the information yield of measurements by identifying appropriate gauge locations. The methods have a high degree of freedom against data needs. They were successfully tested on real and artificial data. For suitable catchments, it is estimated that the optimisation potential amounts up to 30% accuracy improvement compared to nonoptimised gauge distributions. Beside this, a correlation between independent reach parameters and dependent infiltration rates could be identified, which is not dominated by the groundwater head.

  12. Deployment Repeatability

    Science.gov (United States)

    2016-04-01

    evaluating the deployment repeatability builds upon the testing or analysis of deployment kinematics (Chapter 6) and adds repetition. Introduction...material yield or failure during a test. For the purposes of this chapter, zero shift will refer to permanent changes in the structure, while reversible ...the content of other chapters in this book: Gravity Compensation (Chapter 4) and Deployment Kinematics and Dynamics (Chapter 6). Repeating the

  13. Experimental evaluation of rigor mortis. VIII. Estimation of time since death by repeated measurements of the intensity of rigor mortis on rats.

    Science.gov (United States)

    Krompecher, T

    1994-10-21

    The development of the intensity of rigor mortis was monitored in nine groups of rats. The measurements were initiated after 2, 4, 5, 6, 8, 12, 15, 24, and 48 h post mortem (p.m.) and lasted 5-9 h, which ideally should correspond to the usual procedure after the discovery of a corpse. The experiments were carried out at an ambient temperature of 24 degrees C. Measurements initiated early after death resulted in curves with a rising portion, a plateau, and a descending slope. Delaying the initial measurement translated into shorter rising portions, and curves initiated 8 h p.m. or later are comprised of a plateau and/or a downward slope only. Three different phases were observed suggesting simple rules that can help estimate the time since death: (1) if an increase in intensity was found, the initial measurements were conducted not later than 5 h p.m.; (2) if only a decrease in intensity was observed, the initial measurements were conducted not earlier than 7 h p.m.; and (3) at 24 h p.m., the resolution is complete, and no further changes in intensity should occur. Our results clearly demonstrate that repeated measurements of the intensity of rigor mortis allow a more accurate estimation of the time since death of the experimental animals than the single measurement method used earlier. A critical review of the literature on the estimation of time since death on the basis of objective measurements of the intensity of rigor mortis is also presented.

  14. Ratio method of measuring W boson mass

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Feng [Stony Brook Univ., NY (United States)

    2010-08-01

    This dissertation describes an alternative method of measuring the W boson mass in DØ experiment. Instead of extracting MW from the fitting of W → ev fast Monte Carlo simulations to W → ev data as in the standard method, we make the direct fit of transverse mass between W → ev data and Z → ee data. One of the two electrons from Z boson is treated as a neutrino in the calculation of transverse mass. In ratio method, the best fitted scale factor corresponds to the ratio of W and Z boson mass (MW/MZ). Given the precisely measured Z boson mass, W mass is directly fitted from W → ev and Z → ee data. This dissertation demonstrates that ratio method is a plausible method of measuring the W boson mass. With the 1 fb-1 DØ Run IIa dataset, ratio method gives MW = 80435 ± 43(stat) ± 26(sys) MeV.

  15. Method of superconducting joint and its measurement

    International Nuclear Information System (INIS)

    Kim, Woo Gon; Lee, Ho Jin; Hong, Gye Won

    1994-04-01

    The development of joint techniques for superconducting wires is essential to fabricate the high quality superconducting magnet. In this report, the various joining methods and their measuring techniques were reviewed. In order to fabricate a precise superconducting magnet, joining and measuring experiment by using the field decay technique carried out. The contact resistance of coupled specimens with joint was measured as 3.0 x 10 -15 ohm at 1 Tesla which is lower than that of the real operating condition of MRI magnet. It is expected that these data can be used to design and fabricate the superconducting magnets successfully. (Author) 12 refs., 20 figs., 2 tabs

  16. Measurement methods of building structures deflections

    Directory of Open Access Journals (Sweden)

    Wróblewska Magdalena

    2018-01-01

    Full Text Available Underground mining exploitation is leading to the occurrence of deformations manifested by, in particular, sloping terrain. The structures situated on the deforming subsoil are subject to uneven subsidence which is leading in consequence to their deflection. Before a building rectification process takes place by, e.g. uneven raising, the structure's deflection direction and value is determined so that the structure is restored to its vertical position as a result of the undertaken remedial measures. Deflection can be determined by applying classical as well as modern measurement techniques. The article presents examples of measurement methods used considering the measured elements of building structures’ constructions and field measurements. Moreover, for a given example of a mining area, the existing deflections of buildings were compared with mining terrain sloping.

  17. Scale factor measure method without turntable for angular rate gyroscope

    Science.gov (United States)

    Qi, Fangyi; Han, Xuefei; Yao, Yanqing; Xiong, Yuting; Huang, Yuqiong; Wang, Hua

    2018-03-01

    In this paper, a scale factor test method without turntable is originally designed for the angular rate gyroscope. A test system which consists of test device, data acquisition circuit and data processing software based on Labview platform is designed. Taking advantage of gyroscope's sensitivity of angular rate, a gyroscope with known scale factor, serves as a standard gyroscope. The standard gyroscope is installed on the test device together with a measured gyroscope. By shaking the test device around its edge which is parallel to the input axis of gyroscope, the scale factor of the measured gyroscope can be obtained in real time by the data processing software. This test method is fast. It helps test system miniaturized, easy to carry or move. Measure quarts MEMS gyroscope's scale factor multi-times by this method, the difference is less than 0.2%. Compare with testing by turntable, the scale factor difference is less than 1%. The accuracy and repeatability of the test system seems good.

  18. Acoustic methods for measuring bullet velocity

    OpenAIRE

    Courtney, Michael

    2008-01-01

    This article describes two acoustic methods to measure bullet velocity with an accuracy of 1% or better. In one method, a microphone is placed within 0.1 m of the gun muzzle and a bullet is fired at a steel target 45 m away. The bullet's flight time is the recorded time between the muzzle blast and sound of hitting the target minus the time for the sound to return from the target to the microphone. In the other method, the microphone is placed equidistant from both the gun muzzle and the stee...

  19. Diabetic Foot Prevention: Repeatability of the Loran Platform Plantar Pressure and Load Distribution Measurements in Nondiabetic Subjects during Bipedal Standing—A Pilot Study

    Directory of Open Access Journals (Sweden)

    Martha Zequera

    2011-01-01

    Full Text Available This study was designed to assess the repeatability of the Loran Platform and evaluate the variability of plantar pressure and postural balance, during barefoot standing in nondiabetic subjects, for future diabetic foot clinical evaluation. Measurements were taken for eight nondiabetic subjects (4 females, 4 males, aged 47±7.2 years who had no musculoskeletal symptoms. Five variables were measured with the platform in the barefoot standing position. Ten measurements were taken using two different techniques for feet and posture positioning, during three sessions, once a week. For most measurements, no significant effect over time was found with Student's t-test (P<.000125. The ANOVA test of statistical significance confirmed that measurement differences between subjects showed higher variations than measurements taken from the same subject (P<.001. The measurements taken by the Loran Platform system were found to be repeatable.

  20. Radiometric measuring method for egg shells

    Energy Technology Data Exchange (ETDEWEB)

    Forberg, S; Svaerdstroem, K

    1973-02-01

    A description is given of a fast nondestructive radiometric method for registration of the thickness of egg shells of the tawny owl, hen, osprey, and Canada goose. Certain errors are discussed. Measurement of the thickness of egg shells (mineral content per cm/sup 2/) with an accuracy better than 1% is possible in less than one minute under field conditions. (auth)

  1. Gamma spectrometric methods for measuring plutonium

    International Nuclear Information System (INIS)

    Gunnink, R.

    1978-01-01

    Nondestructive analyses of plutonium can be made by detecting and measuring the gamma rays emitted by a sample. Although qualitative and semiquantitative assays can be performed with relative ease, only recently have methods been developed, using computer analysis techniques, that provide quantitative results. This paper reviews some new techniques developed for measuring plutonium. The features of plutonium gamma-ray spectra are reviewed and some of the computer methods used for spectrum analysis are discussed. The discussion includes a description of a powerful computer method of unfolding complex peak multiplets that uses the standard linear least-squares techniques of data analysis. This computer method is based on the generation of response profiles for the isotopes composing a plutonium sample and requires a description of the peak positions, relative intensities, and line shapes. The principles that plutonium isotopic measurements are based on are also developed, followed by illustrations of the measurement procedures as applied to the quantitative analysis of plutonium liquid and solid samples

  2. Repeatability and reproducibility of in situ measurements of sound reflection and airborne sound insulation index of noise barriers

    NARCIS (Netherlands)

    Garai, M.; Schoen, E.; Behler, G.; Bragado, B.; Chudalla, M.; Conter, M.; Defrance, J.; Demizieux, P.; Glorieux, C.; Guidorzi, P.

    2014-01-01

    In Europe, in situ measurements of sound reflection and airborne sound insulation of noise barriers are usually done according to CEN/TS 1793-5. This method has been improved substantially during the EU funded QUIESST collaborative project. Within the same framework, an inter-laboratory test has

  3. Benchmarking sample preparation/digestion protocols reveals tube-gel being a fast and repeatable method for quantitative proteomics.

    Science.gov (United States)

    Muller, Leslie; Fornecker, Luc; Van Dorsselaer, Alain; Cianférani, Sarah; Carapito, Christine

    2016-12-01

    Sample preparation, typically by in-solution or in-gel approaches, has a strong influence on the accuracy and robustness of quantitative proteomics workflows. The major benefit of in-gel procedures is their compatibility with detergents (such as SDS) for protein solubilization. However, SDS-PAGE is a time-consuming approach. Tube-gel (TG) preparation circumvents this drawback as it involves directly trapping the sample in a polyacrylamide gel matrix without electrophoresis. We report here the first global label-free quantitative comparison between TG, stacking gel (SG), and basic liquid digestion (LD). A series of UPS1 standard mixtures (at 0.5, 1, 2.5, 5, 10, and 25 fmol) were spiked in a complex yeast lysate background. TG preparation allowed more yeast proteins to be identified than did the SG and LD approaches, with mean numbers of 1979, 1788, and 1323 proteins identified, respectively. Furthermore, the TG method proved equivalent to SG and superior to LD in terms of the repeatability of the subsequent experiments, with mean CV for yeast protein label-free quantifications of 7, 9, and 10%. Finally, known variant UPS1 proteins were successfully detected in the TG-prepared sample within a complex background with high sensitivity. All the data from this study are accessible on ProteomeXchange (PXD003841). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Repeatability of quantitative 18F-FLT uptake measurements in solid tumors: an individual patient data multi-center meta-analysis.

    Science.gov (United States)

    Kramer, G M; Liu, Y; de Langen, A J; Jansma, E P; Trigonis, I; Asselin, M-C; Jackson, A; Kenny, L; Aboagye, E O; Hoekstra, O S; Boellaard, R

    2018-06-01

    3'-deoxy-3'-[ 18 F]fluorothymidine ( 18 F-FLT) positron emission tomography (PET) provides a non-invasive method to assess cellular proliferation and response to antitumor therapy. Quantitative 18 F-FLT uptake metrics are being used for evaluation of proliferative response in investigational setting, however multi-center repeatability needs to be established. The aim of this study was to determine the repeatability of 18 F-FLT tumor uptake metrics by re-analyzing individual patient data from previously published reports using the same tumor segmentation method and repeatability metrics across cohorts. A systematic search in PubMed, EMBASE.com and the Cochrane Library from inception-October 2016 yielded five 18 F-FLT repeatability cohorts in solid tumors. 18 F-FLT avid lesions were delineated using a 50% isocontour adapted for local background on test and retest scans. SUV max , SUV mean , SUV peak , proliferative volume and total lesion uptake (TLU) were calculated. Repeatability was assessed using the repeatability coefficient (RC = 1.96 × SD of test-retest differences), linear regression analysis, and the intra-class correlation coefficient (ICC). The impact of different lesion selection criteria was also evaluated. Images from four cohorts containing 30 patients with 52 lesions were obtained and analyzed (ten in breast cancer, nine in head and neck squamous cell carcinoma, and 33 in non-small cell lung cancer patients). A good correlation was found between test-retest data for all 18 F-FLT uptake metrics (R 2  ≥ 0.93; ICC ≥ 0.96). Best repeatability was found for SUV peak (RC: 23.1%), without significant differences in RC between different SUV metrics. Repeatability of proliferative volume (RC: 36.0%) and TLU (RC: 36.4%) was worse than SUV. Lesion selection methods based on SUV max  ≥ 4.0 improved the repeatability of volumetric metrics (RC: 26-28%), but did not affect the repeatability of SUV metrics. In multi-center studies

  5. Comparison of diet measures from a food-frequency questionnaire with measures from repeated 24-hour dietary recalls. The Norwegian Women and Cancer Study.

    Science.gov (United States)

    Hjartåker, Anette; Andersen, Lene Frost; Lund, Eiliv

    2007-10-01

    To compare diet measures from a food-frequency questionnaire (FFQ) with measures from 24-hour dietary recalls (24HDRs). The participants answered an FFQ after completing four, repeated 24HDRs during a year. Norway, nationwide. Of 500 women randomly selected from The Norwegian Women and Cancer Study (the Norwegian arm of the European Prospective Investigation into Cancer and Nutrition), 286 agreed to participate and 238 completed the study. On the group level, the FFQ overestimated absolute intake in seven and underestimated intake in six of 21 food groups. Intakes of energy, fat, added sugar and alcohol were lower in the FFQ than in the 24HDRs, whereas intake of fibre was higher. Spearman's rank correlation coefficient ranged from 0.13 (desserts) to 0.82 (coffee) for foods, and from 0.25 (beta-carotene) to 0.67 (alcohol) for nutrients. Three per cent of the observations on nutrient intake fell in the opposite quintile when classified according to the FFQ as compared with the 24HDR. The median calibration coefficient, calculated by regression of the 24HDR data on the FFQ data, was 0.57 for foods and 0.38 for nutrients. The FFQ's ability to rank subjects was good for foods eaten frequently and fairly good for macronutrients in terms of energy percentages. Weaker ranking abilities were seen for foods eaten infrequently and for some micronutrients. The results underline the necessity of performing measurement error corrections.

  6. Computational methods for industrial radiation measurement applications

    International Nuclear Information System (INIS)

    Gardner, R.P.; Guo, P.; Ao, Q.

    1996-01-01

    Computational methods have been used with considerable success to complement radiation measurements in solving a wide range of industrial problems. The almost exponential growth of computer capability and applications in the last few years leads to a open-quotes black boxclose quotes mentality for radiation measurement applications. If a black box is defined as any radiation measurement device that is capable of measuring the parameters of interest when a wide range of operating and sample conditions may occur, then the development of computational methods for industrial radiation measurement applications should now be focused on the black box approach and the deduction of properties of interest from the response with acceptable accuracy and reasonable efficiency. Nowadays, increasingly better understanding of radiation physical processes, more accurate and complete fundamental physical data, and more advanced modeling and software/hardware techniques have made it possible to make giant strides in that direction with new ideas implemented with computer software. The Center for Engineering Applications of Radioisotopes (CEAR) at North Carolina State University has been working on a variety of projects in the area of radiation analyzers and gauges for accomplishing this for quite some time, and they are discussed here with emphasis on current accomplishments

  7. A new method of measuring the thermal flow

    Directory of Open Access Journals (Sweden)

    Grexová Slávka

    2001-03-01

    Full Text Available The subject of this article is the measurement of thermal flow under laboratory conditions. We can define thermal flow as the amount of heat transmitted through the surface of rock over a certain period of time.According to the Atlas of Geothermal Energy the thermal flow ranges from 40 to 120 mW/m2; it is not possible to measure directly on the surface of the rock. The conventional method of measurement is the use of “separation bar” thermic conduction measurement system or to measure the temperature of the rock in two different places at selected underground depth intervals.The method of measurement suggested by us combines these two techniques. The measurement is based on a sample of processed store from the Slovak Academy of Science. This sample represents the rock massiv:The complex model includes:- a heating system to imitate the thermal flow,- an isolation box to maintain stable conditions,- temperature stabilizing components (thermostat, bulbs, electric conductors,- a heat accumulator including a temperature sensor.A special computer program to measure the thermal flow was created using the Borland Delphi 3.0 programming language. The role of the program is to process extensive data quickly. The results of the measured temperatures and modelled thermal flow are displayed graphically in this article. As seen from the graph, the course of measurement thermal flow is linear. In our geographical location this value is cca 120 m W.m-2. This value proves, that at the projection physical model we are approximating to the reality in areas of sensitive elements. Another fact is that Joule heat which rose into a heater system of transformer straps under muster would thermal flow 2,25 W.m-2. From the present results that by follow the sensitivity measurement scanners it is needed to measure a minimum threefold during a longer time or to improve the sensitivity measurement chains.These measurements and analyses are not sufficient to make a final

  8. Automated back titration method to measure phosphate

    International Nuclear Information System (INIS)

    Comer, J.; Tehrani, M.; Avdeef, A.; Ross, J. Jr.

    1987-01-01

    Phosphate was measured in soda drinks and as an additive in flour, by a back titration method in which phosphate was precipitated with lanthanum, and the excess lanthanum was titrated with fluoride. All measurements were performed using the Orion fluoride electrode and the Orion 960 Autochemistry System. In most commercial automatic titrators, the inflection point of the titration curve, calculated from the first derivative of the curve, is used to find the equivalence polar of the titration. The inflection technique is compared with a technique based on Gran functions, which uses data collected after the end point and predicts the equivalence point accordingly

  9. Electric Field Quantitative Measurement System and Method

    Science.gov (United States)

    Generazio, Edward R. (Inventor)

    2016-01-01

    A method and system are provided for making a quantitative measurement of an electric field. A plurality of antennas separated from one another by known distances are arrayed in a region that extends in at least one dimension. A voltage difference between at least one selected pair of antennas is measured. Each voltage difference is divided by the known distance associated with the selected pair of antennas corresponding thereto to generate a resulting quantity. The plurality of resulting quantities defined over the region quantitatively describe an electric field therein.

  10. Quantitative autoradiography - a method of radioactivity measurement

    International Nuclear Information System (INIS)

    Treutler, H.C.; Freyer, K.

    1988-01-01

    In the last years the autoradiography has been developed to a quantitative method of radioactivity measurement. Operating techniques of quantitative autoradiography are demonstrated using special standard objects. Influences of irradiation quality, of backscattering in sample and detector materials, and of sensitivity and fading of the detectors are considered. Furthermore, questions of quantitative evaluation of autoradiograms are dealt with, and measuring errors are discussed. Finally, some practical uses of quantitative autoradiography are demonstrated by means of the estimation of activity distribution in radioactive foil samples. (author)

  11. Comparison of microstickies measurement methods. Part I, sample preparation and measurement methods

    Science.gov (United States)

    Mahendra R. Doshi; Angeles Blanco; Carlos Negro; Gilles M. Dorris; Carlos C. Castro; Axel Hamann; R. Daniel Haynes; Carl Houtman; Karen Scallon; Hans-Joachim Putz; Hans Johansson; R.A. Venditti; K. Copeland; H.-M. Chang

    2003-01-01

    Recently, we completed a project on the comparison of macrostickies measurement methods. Based on the success of the project, we decided to embark on this new project on comparison of microstickies measurement methods. When we started this project, there were some concerns and doubts principally due to the lack of an accepted definition of microstickies. However, we...

  12. New simple method for fast and accurate measurement of volumes

    International Nuclear Information System (INIS)

    Frattolillo, Antonio

    2006-01-01

    A new simple method is presented, which allows us to measure in just a few minutes but with reasonable accuracy (less than 1%) the volume confined inside a generic enclosure, regardless of the complexity of its shape. The technique proposed also allows us to measure the volume of any portion of a complex manifold, including, for instance, pipes and pipe fittings, valves, gauge heads, and so on, without disassembling the manifold at all. To this purpose an airtight variable volume is used, whose volume adjustment can be precisely measured; it has an overall capacity larger than that of the unknown volume. Such a variable volume is initially filled with a suitable test gas (for instance, air) at a known pressure, as carefully measured by means of a high precision capacitive gauge. By opening a valve, the test gas is allowed to expand into the previously evacuated unknown volume. A feedback control loop reacts to the resulting finite pressure drop, thus contracting the variable volume until the pressure exactly retrieves its initial value. The overall reduction of the variable volume achieved at the end of this process gives a direct measurement of the unknown volume, and definitively gets rid of the problem of dead spaces. The method proposed actually does not require the test gas to be rigorously held at a constant temperature, thus resulting in a huge simplification as compared to complex arrangements commonly used in metrology (gas expansion method), which can grant extremely accurate measurement but requires rather expensive equipments and results in time consuming methods, being therefore impractical in most applications. A simple theoretical analysis of the thermodynamic cycle and the results of experimental tests are described, which demonstrate that, in spite of its simplicity, the method provides a measurement accuracy within 0.5%. The system requires just a few minutes to complete a single measurement, and is ready immediately at the end of the process. The

  13. Repeated tumor pO2 measurements by multi-site EPR oximetry as a prognostic marker for enhanced therapeutic efficacy of fractionated radiotherapy

    International Nuclear Information System (INIS)

    Hou Huagang; Lariviere, Jean P.; Demidenko, Eugene; Gladstone, David; Swartz, Harold; Khan, Nadeem

    2009-01-01

    Purpose: To investigate the temporal effects of single or fractionated radiotherapy on subcutaneous RIF-1 tumor pO 2 and to determine the therapeutic outcomes when the timing of fractionations is guided by tumor pO 2 . Methods: The time-course of the tumor pO 2 changes was followed by multi-site electron paramagnetic resonance (EPR) oximetry. The tumors were treated with single 10, 20, and 10 Gy x 2 doses, and the tumor pO 2 was measured repeatedly for six consecutive days. In the 10 Gy x 2 group, the second dose of 10 Gy was delivered at a time when the tumors were either relatively oxygenated or hypoxic. The changes in tumor volumes were followed for nine days to determine the therapeutic outcomes. Results: A significant increase in tumor pO 2 was observed at 24 h post 10 Gy, while 20 Gy resulted in a significant increase in tumor pO 2 at 72-120 h post irradiation. The tumors irradiated with a second dose of 10 Gy at 24 h, when the tumors were oxygenated, had a significant increase in tumor doubling times (DTs), as compared to tumors treated at 48 h when they were hypoxic (p 2 repeatedly during fractionated schemes to optimize radiotherapeutic outcome. This technique could also be used to identify responsive and non-responsive tumors, which will facilitate the design of other therapeutic approaches for non-responsive tumors at early time points during the course of therapy.

  14. Seasonal variation in objectively measured physical activity, sedentary time, cardio-respiratory fitness and sleep duration among 8–11 year-old Danish children: a repeated-measures study

    DEFF Research Database (Denmark)

    Hjorth, Mads F.; Chaput, Jean-Philippe; Michaelsen, Kim

    2013-01-01

    BACKGROUND: Understanding fluctuations in lifestyle indicators is important to identify relevant time periods to intervene in order to promote a healthy lifestyle; however, objective assessment of multiple lifestyle indicators has never been done using a repeated-measures design. The primary aim...... was, therefore, to examine between-season and within-week variation in physical activity, sedentary behaviour, cardio-respiratory fitness and sleep duration among 8–11 year-old children. METHODS: A total of 1021 children from nine Danish schools were invited to participate and 834 accepted. Due...... to missing data, 730 children were included in the current analytical sample. An accelerometer was worn for 7 days and 8 nights during autumn, winter and spring, from which physical activity, sedentary time and sleep duration were measured. Cardio-respiratory fitness was assessed using a 10-min intermittent...

  15. Method for traceable measurement of LTE signals

    Science.gov (United States)

    Sunder Dash, Soumya; Pythoud, Frederic; Leuchtmann, Pascal; Leuthold, Juerg

    2018-04-01

    This contribution presents a reference setup to measure the power of the cell-specific resource elements present in downlink long term evolution (LTE) signals in a way that the measurements are traceable to the international system of units. This setup can be used to calibrate the LTE code-selective field probes that are used to measure the radiation of base stations for mobile telephony. It can also be used to calibrate LTE signal generators and receivers. The method is based on traceable scope measurements performed directly at the output of a measuring antenna. It implements offline digital signal processing demodulation algorithms that consider the digital down-conversion, timing synchronization, frequency synchronization, phase synchronization and robust LTE cell identification to produce the downlink time-frequency LTE grid. Experimental results on conducted test scenarios, both single-input-single-output and multiple-input-multiple-output antenna configuration, show promising results confirming measurement uncertainties of the order of 0.05 dB with a coverage factor of 2.

  16. Application of radiotracer methods in streamflow measurements

    International Nuclear Information System (INIS)

    Dincer, T.

    1967-01-01

    An attempt is made to evaluate methods using radiotracers in streamflow measurements. The basic principles of the tracer method are explained and background information given. Radiotracers used in stream discharge measurements are discussed and measurements made by different research workers are described. Problems such as adsorption of the tracer and the mixing length are discussed and the potential use of the radioisotopes as tracer in the routine stream-gauging work is evaluated. It is concluded that, at the present stage of development, radiotracer methods do not seem to be ready for routine use in stream-gauging work, and can only be used in some special cases. For gamma-emitting radioisotopes there are problems related to safety, transport and injection which should be solved. Tritium, though a very attractive tracer in some respects, has the disadvantages of having a relatively long half-life and of disturbing the natural tritium levels in the region. Finally, an attempt is made to define the objectives of the research in the field of application of radioisotopes in hydrometry. (author)

  17. Does repeat Hb measurement within 2 hours after a normal initial Hb in stable trauma patients add value to trauma evaluation?

    NARCIS (Netherlands)

    Sierink, Joanne C.; Joosse, Pieter; de Castro, Steve M. M.; Schep, Niels W. L.; Goslings, J. Carel

    2014-01-01

    In our level I trauma center, it is considered common practice to repeat blood haemoglobin measurements in patients within 2 h after admission. However, the rationale behind this procedure is elusive and can be considered labour-intensive, especially in patients in whom haemorrhaging is not to be

  18. A dynamic method for magnetic torque measurement

    Science.gov (United States)

    Lin, C. E.; Jou, H. L.

    1994-01-01

    In a magnetic suspension system, accurate force measurement will result in better control performance in the test section, especially when a wider range of operation is required. Although many useful methods were developed to obtain the desired model, however, significant error is inevitable since the magnetic field distribution of the large-gap magnetic suspension system is extremely nonlinear. This paper proposed an easy approach to measure the magnetic torque of a magnetic suspension system using an angular photo encoder. Through the measurement of the velocity change data, the magnetic torque is converted. The proposed idea is described and implemented to obtain the desired data. It is useful to the calculation of a magnetic force in the magnetic suspension system.

  19. Methods of measuring radioactivity in the environment

    Science.gov (United States)

    Isaksson, Mats

    In this thesis a variety of sampling methods have been utilised to assess the amount of deposited activity, mainly of 137Cs, from the Chernobyl accident and from the nuclear weapons tests. Starting with the Chernobyl accident in 1986 sampling of air and rain was used to determine the composition and amount of radioactive debris from this accident, brought to southern Sweden by the weather systems. The resulting deposition and its removal from urban areas was than studied through measurements on sewage sludge and water. The main part of the thesis considers methods of determining the amount of radiocaesium in the ground through soil sampling. In connection with soil sampling a method of optimising the sampling procedure has been developed and tested in the areas of Sweden which have a comparatively high amount of 137Cs from the Chernobyl accident. This method was then used in a survey of the activity in soil in Lund and Skane, divided between nuclear weapons fallout and fallout from the Chernobyl accident. By comparing the results from this survey with deposition calculated from precipitation measurements it was found possible to predict the deposition pattern over Skane for both nuclear weapons fallout and fallout from the Chernobyl accident. In addition, the vertical distribution of 137Cs has been modelled and the temporal variation of the depth distribution has been described.

  20. Repeatability of Volume and Regional Body Composition Measurements of the Lower Limb Using Dual-energy X-ray Absorptiometry

    DEFF Research Database (Denmark)

    Gjorup, Caroline A; Zerahn, Bo; Juul, Sarah

    2017-01-01

    was calculated using the density of bone mineral content, fat, and lean mass. The repeatability of the volume of the lower limb and regional thigh and lower leg tissue composition (bone mineral content, fat, and lean mass) was good with intraclass correlation coefficient values of 0.97 to 0.99, and narrow limits...

  1. Secondhand tobacco smoke exposure and heart rate variability and inflammation among non-smoking construction workers: a repeated measures study.

    Science.gov (United States)

    Zhang, Jinming; Fang, Shona C; Mittleman, Murray A; Christiani, David C; Cavallari, Jennifer M

    2013-10-02

    Although it has been well recognized that exposure to secondhand tobacco smoke (SHS) is associated with cardiovascular mortality, the mechanisms and time course by which SHS exposure may lead to cardiovascular effects are still being explored. Non-smoking workers were recruited from a local union and monitored inside a union hall while exposed to SHS over approximately 6 hours. Participants were fitted with a continuous electrocardiographic monitor upon enrollment which was removed at the end of a 24-hr monitoring period. A repeated measures study design was used where resting ECGs and blood samples were taken from individuals before SHS exposure (baseline), immediately following SHS exposure (post) and the morning following SHS exposure (next-morning).Inflammatory markers, including high sensitivity C-reactive protein (CRP) and white blood cell count (WBC) were analyzed. Heart rate variability (HRV) was analyzed from the ECG recordings in time (SDNN, rMSSD) and frequency (LF, HF) domain parameters over 5-minute periods. SHS exposure was quantified using a personal fine particulate matter (PM2.5) monitor.Linear mixed effects regression models were used to examine within-person changes in inflammatory and HRV parameters across the 3 time periods. Exposure-response relationships with PM2.5 were examined using mixed effects models. All models were adjusted for age, BMI and circadian variation. A total of 32 male non-smokers were monitored between June 2010 and June 2012. The mean PM2.5 from SHS exposure was 132 μg/m3. Immediately following SHS exposure, a 100 μg/m3 increase in PM2.5 was associated with declines in HRV (7.8% [standard error (SE) =3%] SDNN, 8.0% (SE = 3.9%) rMSSD, 17.2% (SE = 6.3%) LF, 29.0% (SE = 10.1%) HF) and increases in WBC count 0.42 (SE = 0.14) k/μl. Eighteen hours following SHS exposure, a 100 μg/m3 increase in PM2.5 was associated with 24.2% higher CRP levels. Our study suggest that short-term SHS exposure is associated

  2. Ambient temperature and cardiovascular biomarkers in a repeated-measure study in healthy adults: A novel biomarker index approach.

    Science.gov (United States)

    Wu, Shaowei; Yang, Di; Pan, Lu; Shan, Jiao; Li, Hongyu; Wei, Hongying; Wang, Bin; Huang, Jing; Baccarelli, Andrea A; Shima, Masayuki; Deng, Furong; Guo, Xinbiao

    2017-07-01

    Associations of ambient temperature with cardiovascular morbidity and mortality have been well documented in numerous epidemiological studies, but the underlying pathways remain unclear. We investigated whether systemic inflammation, coagulation, systemic oxidative stress, antioxidant activity and endothelial function may be the mechanistic pathways associated with ambient temperature. Forty study participants underwent repeated blood collections for 12 times in Beijing, China in 2010-2011. Ambient temperature and air pollution data were measured in central monitors close to student residences. We created five indices as the sum of weighted biomarker percentiles to represent the overall levels of 15 cardiovascular biomarkers in five pathways (systemic inflammation: hs-CRP, TNF-α and fibrinogen; coagulation: fibrinogen, PAI-1, tPA, vWF and sP-selectin; systemic oxidative stress: Ox-LDL and sCD36: antioxidant activity: EC-SOD and GPX1; and endothelial function: ET-1, E-selectin, ICAM-1 and VCAM-1). We used generalized mixed-effects models to estimate temperature effects controlling for air pollution and other covariates. There were significant decreasing trends in the adjusted means of biomarker indices over the lowest to the highest quartiles of daily temperatures before blood collection. A 10°C decrease at 2-d average daily temperature were associated with increases of 2.5% [95% confidence interval (CI): 0.7, 4.2], 1.6% (95% CI: 0.1, 3.1), 2.7% (95% CI: 0.5, 4.8), 5.5% (95% CI: 3.8, 7.3) and 2.0% (95% CI: 0.3, 3.8) in the indices for systemic inflammation, coagulation, systemic oxidative stress, antioxidant activity and endothelial function, respectively. In contrast, the associations between ambient temperature and individual biomarkers had substantial variation in magnitude and strength. The altered cardiovascular biomarker profiles in healthy adults associated with ambient temperature changes may help explain the temperature-related cardiovascular morbidity

  3. Large subcriticality measurement by pulsed neutron method

    International Nuclear Information System (INIS)

    Yamane, Y.; Yoshida, A.; Nishina, K.; Kobayashi, K.; Kanda, K.

    1985-01-01

    To establish the method determining large subcriticalities in the field of nuclear criticality safety, the authors performed pulsed neutron experiments using the Kyoto University Critical Assembly (KUCA) at Research Reactor Institute, Kyoto University and the Cockcroft-Walton type accelerator attached to the assembly. The area-ratio method proposed by Sjoestrand was employed to evaluate subcriticalities from neutron decay curves measured. This method has the shortcomings that the neutron component due to a decay of delayed neutrons remarkably decreases as the subcriticality of an objective increases. To overcome the shortcoming, the authors increased the frequency of pulsed neutron generation. The integral-version of the area-ratio method proposed by Kosaly and Fisher was employed in addition in order to remove a contamination of spatial higher modes from the decay curve. The latter becomes significant as subcriticality increases. The largest subcriticality determined in the present experiments was 125.4 dollars, which was equal to 0.5111 in a multiplication factor. The calculational values evaluated by the computer code KENO-IV with 137 energy groups based on the Monte Carlo method agreed well with those experimental values

  4. Measurement of gastric emptying rate in humans. Simplified scanning method

    Energy Technology Data Exchange (ETDEWEB)

    Holt, S.; Colliver, J.; Guram, M.; Neal, C.; Verhulst, S.J.; Taylor, T.V. (Univ. of South Carolina School of Medicine, Columbia (USA))

    1990-11-01

    Simultaneous measurements of the gastric emptying rate of the solid and liquid phase of a dual-isotope-labeled test meal were made using a gamma camera and a simple scintillation detector, similar to that used in a hand-held probe. A simple scanning apparatus, similar to that used in a hand-held scintillation probe, was compared with simultaneous measurements made by a gamma camera in 16 healthy males. A dual-labeled test meal was utilized to measure liquid and solid emptying simultaneously. Anterior and posterior scans were taken at intervals up to 120 min using both a gamma camera and the scintillation probe. Good relative agreement between the methods was obtained both for solid-phase (correlation range 0.92-0.99, mean 0.97) and for liquid-phase data (correlation range 0.93-0.99, mean 0.97). For solid emptying data regression line slopes varied from 0.75 to 1.03 (mean 0.84). Liquid emptying data indicated that slopes ranged from 0.71 to 1.06 (mean 0.87). These results suggested that an estimate of the gamma measurement could be obtained by multiplying the scintillation measurement by a factor of 0.84 for the solid phase and 0.87 for the liquid phase. Correlation between repeat studies was 0.97 and 0.96 for solids and liquids, respectively. The application of a hand-held probe technique provides a noninvasive and inexpensive method for accurately assessing solid- and liquid-phase gastric emptying from the human stomach that correlates well with the use of a gamma camera, within the range of gastric emptying rate in the normal individuals in this study.

  5. Measurement of gastric emptying rate in humans. Simplified scanning method

    International Nuclear Information System (INIS)

    Holt, S.; Colliver, J.; Guram, M.; Neal, C.; Verhulst, S.J.; Taylor, T.V.

    1990-01-01

    Simultaneous measurements of the gastric emptying rate of the solid and liquid phase of a dual-isotope-labeled test meal were made using a gamma camera and a simple scintillation detector, similar to that used in a hand-held probe. A simple scanning apparatus, similar to that used in a hand-held scintillation probe, was compared with simultaneous measurements made by a gamma camera in 16 healthy males. A dual-labeled test meal was utilized to measure liquid and solid emptying simultaneously. Anterior and posterior scans were taken at intervals up to 120 min using both a gamma camera and the scintillation probe. Good relative agreement between the methods was obtained both for solid-phase (correlation range 0.92-0.99, mean 0.97) and for liquid-phase data (correlation range 0.93-0.99, mean 0.97). For solid emptying data regression line slopes varied from 0.75 to 1.03 (mean 0.84). Liquid emptying data indicated that slopes ranged from 0.71 to 1.06 (mean 0.87). These results suggested that an estimate of the gamma measurement could be obtained by multiplying the scintillation measurement by a factor of 0.84 for the solid phase and 0.87 for the liquid phase. Correlation between repeat studies was 0.97 and 0.96 for solids and liquids, respectively. The application of a hand-held probe technique provides a noninvasive and inexpensive method for accurately assessing solid- and liquid-phase gastric emptying from the human stomach that correlates well with the use of a gamma camera, within the range of gastric emptying rate in the normal individuals in this study

  6. Repeating Marx

    DEFF Research Database (Denmark)

    Fuchs, Christian; Monticelli, Lara

    2018-01-01

    This introduction sets out the context of the special issue “Karl Marx @ 200: Debating Capitalism & Perspectives for the Future of Radical Theory”, which was published on the occasion of Marx’s bicentenary on 5 May 2018. First, we give a brief overview of contemporary capitalism’s development...... and its crises. Second, we argue that it is important to repeat Marx today. Third, we reflect on lessons learned from 200 years of struggles for alternatives to capitalism. Fourth, we give an overview of the contributions in this special issue. Taken together, the contributions in this special issue show...... that Marx’s theory and politics remain key inspirations for understanding exploitation and domination in 21st-century society and for struggles that aim to overcome these phenomena and establishing a just and fair society. We need to repeat Marx today....

  7. Novel Methods for Measuring LiDAR

    Science.gov (United States)

    Ayrey, E.; Hayes, D. J.; Fraver, S.; Weiskittel, A.; Cook, B.; Kershaw, J.

    2017-12-01

    The estimation of forest biometrics from airborne LiDAR data has become invaluable for quantifying forest carbon stocks, forest and wildlife ecology research, and sustainable forest management. The area-based approach is arguably the most common method for developing enhanced forest inventories from LiDAR. It involves taking a series of vertical height measurements of the point cloud, then using those measurements with field measured data to develop predictive models. Unfortunately, there is considerable variation in methodology for collecting point cloud data, which can vary in pulse density, seasonality, canopy penetrability, and instrument specifications. Today there exists a wealth of public LiDAR data, however the variation in acquisition parameters makes forest inventory prediction by traditional means unreliable across the different datasets. The goal of this project is to test a series of novel point cloud measurements developed along a conceptual spectrum of human interpretability, and then to use the best measurements to develop regional enhanced forest inventories on Northern New England's and Atlantic Canada's public LiDAR. Similarly to a field-based inventory, individual tree crowns are being segmented, and summary statistics are being used as covariates. Established competition and structural indices are being generated using each tree's relationship to one another, whilst existing allometric equations are being used to estimate diameter and biomass of each tree measured in the LiDAR. Novel metrics measuring light interception, clusteredness, and rugosity are also being measured as predictors. On the other end of the human interpretability spectrum, convolutional neural networks are being employed to directly measure both the canopy height model, and the point clouds by scanning each using two and three dimensional kernals trained to identify features useful for predicting biological attributes such as biomass. Predictive models will be trained and

  8. Two methods to measure granular gas temperature

    Science.gov (United States)

    Chastaing, J.-Y.; Géminard, J.-C.; Naert, A.

    2017-07-01

    Grains are vibrated so as to achieve a granular gas, here regarded as an archetype of a dissipative non equilibrium steady state (NESS). We report on two distinct and concordant experimental measures of the system effective temperature. To do so, a blade fastened to the shaft of a small DC-motor, immersed in the grains, behaves as a driven 1D Brownian rotator, which is used as both actuator and sensor simultaneously. On the one hand, the Gallavotti-Cohen fluctuation theorem, which involves a measure of the asymmetry of the energy exchanges between the rotator and the NESS reservoir, provides a first effective temperature. On the other hand, the fluctuation-dissipation theorem, which involves the relation between the spontaneous fluctuations and the response to a weak perturbation, defines a second, independent, effective temperature. Both methods, even though they are based on drastically different ideas, give nicely concordant results.

  9. Method for steam generator water level measurement

    International Nuclear Information System (INIS)

    Srinivasan, J.S.

    1991-01-01

    This paper describes a nuclear power plant, a method of controlling the steam generator water level, wherein the steam generator has an upper level tap corresponding to an upper level, a lower level, a riser positioned between the lower and upper taps, and level sensor means for indicating water level between a first range limit and a second range limit, the sensor means being connected to at least the lower tap. It comprises: calculating a measure of velocity head at about the lower level tap; calculating a measure of full water level as the upper level less the measure of velocity head; calibrating the level sensor means to provide an output at the first limit corresponding to an input thereto representative of the measure of full level; calculating a high level setpoint equal to the level of the riser less a bias amount which is a function of the position of the riser relative to the span between the taps; and controlling the water level when the sensor means indicates that the high level setpoint has been reached

  10. Measuring and controlling method for organic impurities

    International Nuclear Information System (INIS)

    Aizawa, Motohiro; Igarashi, Hiroo

    1995-01-01

    The present invention concerns measurement and control for organic impurities contained in ultrapurified water for use in a nuclear power plant. A specimen containing organic impurities leached out of anionic exchange resins and cationic exchange resins is introduced to an organic material decomposing section to decompose organic impurities into organic carbon and other decomposed products. Sulfate ions, nitrate ions, nitrite ions and carbon dioxide are produced by the decomposition of the organic impurities. As a next step, carbon dioxide in the decomposed products is separated by deaerating with a nitrogen gas or an argon gas and then a TOC concentration is measured by a non-dispersion-type infrared spectrometer. Further, a specimen from which carbon dioxide was separated is introduced to a column filled with ion exchange resins and, after concentrating inorganic ion impurities, the inorganic ion impurities are identified by using a measuring theory of an ion chromatographic method of eluting and separating inorganic ion impurities and detecting them based on the change of electroconductivity depending on the kinds of the inorganic ion impurities. Organic impurities can be measured and controlled, to improve the reliability of water quality control. (N.H.)

  11. Faraday rotation measurement method and apparatus

    Science.gov (United States)

    Brockman, M. H. (Inventor)

    1981-01-01

    A method and device for measuring Faraday rotation of a received RF signal is described. A simultaneous orthogonal polarization receiver compensates for a 3 db loss due to splitting of a received signal into left circular and right circular polarization channels. The compensation is achieved by RF and modulation arraying utilizing a specific receiver array which also detects and measures Faraday rotation in the presence or absence of spin stabilization effects on a linear polarization vector. Either up-link or down-link measurement of Faraday rotation is possible. Specifically, the Faraday measurement apparatus utilized in conjunction with the specific receiver array provides a means for comparing the phase of a reference signal in the receiver array to the phase of a tracking loop signal related to the incoming signal, and comparing the phase of the reference signal to the phase of the tracking signal shifted in phase by 90 degrees. The averaged and unaveraged signals, are compared, the phase changes between the two signals being related to Faraday rotation.

  12. Deployment Repeatability

    Science.gov (United States)

    2016-08-31

    large cohort of trials to spot unusual cases. However, deployment repeatability is inherently a nonlinear phenomenon, which makes modeling difficult...and GEMS tip position were both tracked during ground testing by a laser target tracking system. Earlier SAILMAST testing in 2005 [8] used...recalls the strategy used by SRTM, where a constellation of lights was installed at the tip of the boom and a modified star tracker was used to track tip

  13. Acoustic levitation methods for density measurements

    Science.gov (United States)

    Trinh, E. H.; Hsu, C. J.

    1986-01-01

    The capability of ultrasonic levitators operating in air to perform density measurements has been demonstrated. The remote determination of the density of ordinary liquids as well as low density solid metals can be carried out using levitated samples with size on the order of a few millimeters and at a frequency of 20 kHz. Two basic methods may be used. The first one is derived from a previously known technique developed for acoustic levitation in liquid media, and is based on the static equilibrium position of levitated samples in the earth's gravitational field. The second approach relies on the dynamic interaction between a levitated sample and the acoustic field. The first technique appears more accurate (1 percent uncertainty), but the latter method is directly applicable to a near gravity-free environment such as that found in space.

  14. Method of measuring a liquid pool volume

    Science.gov (United States)

    Garcia, G.V.; Carlson, N.M.; Donaldson, A.D.

    1991-03-19

    A method of measuring a molten metal liquid pool volume and in particular molten titanium liquid pools is disclosed, including the steps of (a) generating an ultrasonic wave at the surface of the molten metal liquid pool, (b) shining a light on the surface of a molten metal liquid pool, (c) detecting a change in the frequency of light, (d) detecting an ultrasonic wave echo at the surface of the molten metal liquid pool, and (e) computing the volume of the molten metal liquid. 3 figures.

  15. Electromagnetic compatibility methods, analysis, circuits, and measurement

    CERN Document Server

    Weston, David A

    2016-01-01

    Revised, updated, and expanded, Electromagnetic Compatibility: Methods, Analysis, Circuits, and Measurement, Third Edition provides comprehensive practical coverage of the design, problem solving, and testing of electromagnetic compatibility (EMC) in electrical and electronic equipment and systems. This new edition provides novel information on theory, applications, evaluations, electromagnetic computational programs, and prediction techniques available. With sixty-nine schematics providing examples for circuit level electromagnetic interference (EMI) hardening and cost effective EMI problem solving, this book also includes 1130 illustrations and tables. Including extensive data on components and their correct implementation, the myths, misapplication, misconceptions, and fallacies that are common when discussing EMC/EMI will also be addressed and corrected.

  16. Gravimetric capillary method for kinematic viscosity measurements

    Science.gov (United States)

    Rosenberger, Franz; Iwan, J.; Alexander, D.; Jin, Wei-Qing

    1992-01-01

    A novel version of the capillary method for viscosity measurements of liquids is presented. Viscosity data can be deduced in a straightforward way from mass transfer data obtained by differential weighing during the gravity-induced flow of the liquid between two cylindrical chambers. Tests of this technique with water, carbon tetrachloride, and ethanol suggest that this arrangement provides an accuracy of about +/- 1 percent. The technique facilitates operation under sealed, isothermal conditions and, thus can readily be applied to reactive and/or high vapor pressure liquids.

  17. The influence of learning methods on collaboration: prior repeated retrieval enhances retrieval organization, abolishes collaborative inhibition, and promotes post-collaborative memory.

    Science.gov (United States)

    Congleton, Adam R; Rajaram, Suparna

    2011-11-01

    Research on collaborative memory has unveiled the counterintuitive yet robust phenomenon that collaboration impairs group recall. A candidate explanation for this collaborative inhibition effect is the disruption of people's idiosyncratic retrieval strategies during collaboration, and it is hypothesized that employing methods that improve one's organization protects against retrieval disruption. Here it is investigated how one's learning method during the study phase--defined as either repeatedly studying or repeatedly retrieving information--influences retrieval organization and what effects this has on collaborative recall and post-collaborative individual recall. Results show that repeated retrieval consistently eliminated collaborative inhibition. This enabled participants to gain the most from re-exposure to materials recalled by their partners that they themselves did not recall and led to improvements in their individual memory following collaboration. This repeated retrieval advantage stemmed from the preferential manner in which this learning method strengthened retrieval organization. Findings are also discussed that reveal a relationship between retrieval organization and the interaction observed between learning method and short versus long delay seen in the testing effect literature. Finally, results show that the elusive benefits of cross-cuing during collaboration may be best detected with a longer study-test delay. Together, these findings illuminate when and how collaboration can enhance memory.

  18. The method of purging applied to repeated cross-sectional data: Practical applications using logistic and linear regression analysis

    NARCIS (Netherlands)

    Grotenhuis, H.F. te; Eisinga, R.N.; Scheepers, P.L.H.

    2004-01-01

    In cross-sectional survey research, it is quite common to estimate the(standardized) effect of independent variable(s) on a dependent variable. However, if repeated cross-sectional data are available, much is to be gained if the consequences of these effects on longitudinal social change are

  19. An approach for evaluating the repeatability of rapid wetland assessment methods: The effects of training and experience

    Science.gov (United States)

    We sampled 92 wetlands from four different basins in the United States to quantify observer repeatability in rapid wetland condition assessment using the Delaware Rapid Assessment Protocol (DERAP). In the Inland Bays basin of Delaware, 58 wetland sites were sampled by multiple ob...

  20. How to measure kyphosis in everyday clinical practice: a reliability study on different methods.

    Science.gov (United States)

    Zaina, Fabio; Donzelli, Sabrina; Lusini, Monia; Negrini, Stefano

    2012-01-01

    The sagittal plane measures have a relevant role both in Idiopathic Scoliosis (AIS) and in Hyperkyphosis (HK) management. Nevertheless, clinical tools for everyday use are scarce and not adequately studied. To assess the repeatability of different methods for the collection of the sagittal profile of patients with spinal deformities during everyday clinics. We performed 4 different studies in 4 different populations of AIS and HK patients. In the first study we reported the normative data and measurement error of the plumbline measures in a general population of 180 adolescents. In the second study we compared the sagittal distances from the plumbline of C7, T12, L3, and Sagittal Index (SI = C7+L3) with the measures of the Video Rasterstereography at the same levels and the angles of kyphosis and lordosis in 100 AIS patients. In the third study we evaluated the intra and inter-rater repeatability and the measurement error of kyphosis and lordosis angles measured with the Inclimed in 100 AIS patients. In the last study we evaluated the repeatability of the sagittal distances from the plumbline, by using a 1 mm change instead of 5 mm in a population of 40 patients. repeatability has been evaluated according to Bland and Altman, to identify the limits of variation that are clinically significant. Results. Study 1: the normative data were: females: 34 ± 11 mm for C7; 34 ± 15 mm for L3, males: 34 ± 10 mm for C7; 48 ± 10 mm for L3;. Study 2: a coefficient of correlation was calculated in order to compare measures. Study 3: the k value for Inclimed varied from fair to good. Study 4: the repeatability was fair for this measure. Some clinical instruments are now available for sagittal plane assessment in AIS and hyperkyphosis. The results of the present study report the limits during measurements in a clinical setting of parameters that are routinely collected by some clinicians.

  1. Portable method of measuring gaseous acetone concentrations.

    Science.gov (United States)

    Worrall, Adam D; Bernstein, Jonathan A; Angelopoulos, Anastasios P

    2013-08-15

    Measurement of acetone in human breath samples has been previously shown to provide significant non-invasive diagnostic insight into the control of a patient's diabetic condition. In patients with diabetes mellitus, the body produces excess amounts of ketones such as acetone, which are then exhaled during respiration. Using various breath analysis methods has allowed for the accurate determination of acetone concentrations in exhaled breath. However, many of these methods require instrumentation and pre-concentration steps not suitable for point-of-care use. We have found that by immobilizing resorcinol reagent into a perfluorosulfonic acid polymer membrane, a controlled organic synthesis reaction occurs with acetone in a dry carrier gas. The immobilized, highly selective product of this reaction (a flavan) is found to produce a visible spectrum color change which could measure acetone concentrations to less than ppm. We here demonstrate how this approach can be used to produce a portable optical sensing device for real-time, non-invasive acetone analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Method of measuring reactor water level

    International Nuclear Information System (INIS)

    Shinohara, Kaoru.

    1979-01-01

    Purpose: To provide a water level measuring system so that a reactor water level detecting signal can be corrected in correspondence to a recirculation flow, thereby to carry out a correct water level detection in a wide range of the reactor. Method: According to the operation record of a precursor reactor, the ratio Δh of the lowering of the water level due to the recirculation flow is lowered in proportion to the ratiowith respect to the rated differential pressure of the recirculation flow. Accordingly, the flow of recirculation pump is measured by an elbow differential pressure generator utilizing an elbow of a pipe, and the measured value is multiplied by a gain by a ratio setter, and therefter, an addition computation is carried out by an adder for correcting the signal from a water level detector. When the signal from the water level detector is corrected in this manner, the influence of the lowering of the water level due to the recirculation flow can be removed, and an interlocker predetermined in the defined water level can be actuated, thus the influence of the dynamic pressure due to the recirculation flow acting on the instrumental pipe line detecting the reactor water level can be removed effectively. (Yoshino, Y.)

  3. Express method and radon gas measurement detector

    International Nuclear Information System (INIS)

    Khajdarov, R.A.; Khajdarov, R.R.

    2004-01-01

    The purpose of this work was to improve the activated charcoal adsorption method. The detector consisted of an electronic unit (200 mm x 180 mm x 80 mm) and a scintillation cell (a tube 200 mm long, 60 mm diam.). The electronic unit contained a power supply, amplifier, discriminator, timer, counter and indicator. The scintillation cell contained a zinc sulfide scintillator, photomultiplier, preamplifier, high voltage power supply and a 200 ml chamber above the scintillator. This chamber was intended to situate activated carbon fibrous absorber and air compressor. In this method, air is drawn through a filter to remove radon decay products and then through the activated carbon cloth by using a compressor. Sampling takes between 5 and 15 minutes. After the sampling, the cloth is heated for 5-10 sec up to 200-250 deg C by electric current passing through the fiber. Radon gas evaporates from the cloth and the device detects scintillation pulses. Owing to a high radon preconcentration factor (by adsorption of radon on the activated carbon cloth from 50-150 L of air of and evaporation into the small volume of the chamber), the detection limit of the method is 2-4 Bq/m 3 . Since the distance between the filter, cloth and scintillator is over 80 mm, the detector only measures radiation from radon without interference from the radon decay products, remaining in the filter and cloth

  4. Rock stress measurements using the LUT-Gauge overcoring method

    International Nuclear Information System (INIS)

    Leijon, B.

    1988-04-01

    With overcoring techniques, rock stresses are determined indirectly from measurements of the dimensional changes of a borehole, occurring when the rock volume surrounding the hole is isolated from the stresses in the host rock. This thesis describes the development and application of an overcoring technique. The key-component of the instrumentation that has been developed is a triaxial borehole strain cell, referred to as the LUT-Gauge. Laboratory tests were conducted to evaluate the performance of the instrumentation. Special emphasis was given to determining temperature sensitivity of the measuring system since this was identified as a potential source of measurement error. Results indicated good instrument reliability and that the measurement error due to temperature variations typically experienced under field conditions is ± 1 MPa or less. The technique was also evaluated by a series of field tests. Comparison of the results obtained by the different methods showed satisfactory agreement. Analysis of the comprehensive field data collected showed that the confidence that can be attached to an overcoring test is largely governed by the mechanical characteristics of the overcored specimen. Expressed as the standard deviation of the mean stress magnitude, the scatter obtained from repeated testing within a borehole section of about 10 m in length, is found to be ± 4 MPa or less. Rock engineering investigations typically refer to a scale of hundreds of metres or more. This study has demonstrated the existence of significant variations of the stress field on this scale. These variations thus impose difficulties in the application of stress data to the analysis of problems in rock engineering, since the pointwise results obtained from stress measurements cannot be extrapolated with good confidence. (30 refs.) (author)

  5. Measuring ambiguity in HLA typing methods.

    Directory of Open Access Journals (Sweden)

    Vanja Paunić

    Full Text Available In hematopoietic stem cell transplantation, donor selection is based primarily on matching donor and patient HLA genes. These genes are highly polymorphic and their typing can result in exact allele assignment at each gene (the resolution at which patients and donors are matched, but it can also result in a set of ambiguous assignments, depending on the typing methodology used. To facilitate rapid identification of matched donors, registries employ statistical algorithms to infer HLA alleles from ambiguous genotypes. Linkage disequilibrium information encapsulated in haplotype frequencies is used to facilitate prediction of the most likely haplotype assignment. An HLA typing with less ambiguity produces fewer high-probability haplotypes and a more reliable prediction. We estimated ambiguity for several HLA typing methods across four continental populations using an information theory-based measure, Shannon's entropy. We used allele and haplotype frequencies to calculate entropy for different sets of 1,000 subjects with simulated HLA typing. Using allele frequencies we calculated an average entropy in Caucasians of 1.65 for serology, 1.06 for allele family level, 0.49 for a 2002-era SSO kit, and 0.076 for single-pass SBT. When using haplotype frequencies in entropy calculations, we found average entropies of 0.72 for serology, 0.73 for allele family level, 0.05 for SSO, and 0.002 for single-pass SBT. Application of haplotype frequencies further reduces HLA typing ambiguity. We also estimated expected confirmatory typing mismatch rates for simulated subjects. In a hypothetical registry with all donors typed using the same method, the entropy values based on haplotype frequencies correspond to confirmatory typing mismatch rates of 1.31% for SSO versus only 0.08% for SBT. Intermediate-resolution single-pass SBT contains the least ambiguity of the methods we evaluated and therefore the most certainty in allele prediction. The presented measure

  6. Measuring Ambiguity in HLA Typing Methods

    Science.gov (United States)

    Madbouly, Abeer; Freeman, John; Maiers, Martin

    2012-01-01

    In hematopoietic stem cell transplantation, donor selection is based primarily on matching donor and patient HLA genes. These genes are highly polymorphic and their typing can result in exact allele assignment at each gene (the resolution at which patients and donors are matched), but it can also result in a set of ambiguous assignments, depending on the typing methodology used. To facilitate rapid identification of matched donors, registries employ statistical algorithms to infer HLA alleles from ambiguous genotypes. Linkage disequilibrium information encapsulated in haplotype frequencies is used to facilitate prediction of the most likely haplotype assignment. An HLA typing with less ambiguity produces fewer high-probability haplotypes and a more reliable prediction. We estimated ambiguity for several HLA typing methods across four continental populations using an information theory-based measure, Shannon's entropy. We used allele and haplotype frequencies to calculate entropy for different sets of 1,000 subjects with simulated HLA typing. Using allele frequencies we calculated an average entropy in Caucasians of 1.65 for serology, 1.06 for allele family level, 0.49 for a 2002-era SSO kit, and 0.076 for single-pass SBT. When using haplotype frequencies in entropy calculations, we found average entropies of 0.72 for serology, 0.73 for allele family level, 0.05 for SSO, and 0.002 for single-pass SBT. Application of haplotype frequencies further reduces HLA typing ambiguity. We also estimated expected confirmatory typing mismatch rates for simulated subjects. In a hypothetical registry with all donors typed using the same method, the entropy values based on haplotype frequencies correspond to confirmatory typing mismatch rates of 1.31% for SSO versus only 0.08% for SBT. Intermediate-resolution single-pass SBT contains the least ambiguity of the methods we evaluated and therefore the most certainty in allele prediction. The presented measure objectively evaluates HLA

  7. Effect of exercise order on the number of repeats and training volume in the tri-set training method

    Directory of Open Access Journals (Sweden)

    Waynne Ferreira de Faria

    2016-05-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n2p187   Although the tri-set system is widely adopted by athletes and experienced weight training practitioners aimed at optimizing the metabolic overload, there are still few works in literature on the effect of exercise order manipulation on this training system. Therefore, this work was aimed at investigating the effect of exercise order manipulation on the number of repeats and training volume using the tri-set system for lower limbs. This is a randomized cross-over design study. The experimental group consisted of 14 healthy men (23.53 ± 5.40 years; 24.51 ± 2.96 kg/m2. Subjects were submitted to two experimental sessions at different exercise order for lower limbs: Sequence A: squat on guided bar, leg press 45° and bilateral leg extension; sequence B: bilateral leg extension, leg press 45° and squat on guided bar. Three sets to volitional fatigue in all exercises were performed, with intensity of 75% 1RM. Superiority for sequence B in the total number of repeats (70.14 ± 13 vs 60.93 ± 7.94 repeats, p = 0.004 and total training volume (9129.64 ± 2830.05 vs 8238.29 ± 2354.20 kg, p = 0.014 was observed. Based on the above, the performance of single-joint exercises before multi-joint exercises in the tri-set system adopted for lower limbs induced higher number of repeats and total training volume.

  8. A drop penetration method to measure powder blend wettability.

    Science.gov (United States)

    Wang, Yifan; Liu, Zhanjie; Muzzio, Fernando; Drazer, German; Callegari, Gerardo

    2018-03-01

    Water wettability of pharmaceutical blends affects important quality attributes of final products. We investigate the wetting properties of a pharmaceutical blend lubricated with Magnesium Stearate (MgSt) as a function of the mechanical shear strain applied to the blend. We measure the penetration dynamics of sessile drops deposited on slightly compressed powder beds. We consider a blend composed of 9% Acetaminophen 90% Lactose and 1% MgSt by weight. Comparing the penetration time of water and a reference liquid Polydimethylsiloxane (silicon oil) we obtain an effective cosine of the contact angle with water, based on a recently developed drop penetration method. We repeat the experiments for blends exposed to increasing levels of shear strain and demonstrate a significant decrease in water wettability (decrease in the cosine of the contact angle). The results are consistent with the development of a hydrophobic film coating the powder particles as a result of the increased shear strain. Finally, we show that, as expected dissolution times increase with the level of shear strain. Therefore, the proposed drop penetration method could be used to directly assess the state of lubrication of a pharmaceutical blend and act as a quality control on powder blend attributes before the blend is tableted. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Method of measuring blood flow by radiation

    International Nuclear Information System (INIS)

    Gildenberg, P.L.

    1977-01-01

    A method of measuring relative blood flow through at least a part of the body using penetrating radiation comprises transmitting a plurality of rays at an initial angle or initial mean angle through a planar slice of the body to define a first set of rays, transmitting a plurality of further sets of rays at angles or mean angles different from each other and from the initial angle or initial mean angle through the same planar slice of the body to define by the intersection of all such rays a two-dimensional matrix of elements of the body in the slice, measuring for each ray emerging from the body a number of over the period of time at least equal to a pulse interval representing the momentary sum of the transmissions or absorptions of the element of the body intersected by the ray, determining from the momentary signals momentary signals a difference signal representing the maximum difference between the momentary signals for each ray over the period of time, deriving sets of discrete difference signals corresponding to the sets of rays, the difference signals being indicative of the transmission or absorption of blood flowing through each element of the body in the matrix, and calculating from the difference signals resultant signals representing the transmissions or absorptions due to blood flow in the elements of the matrix. These resultant signals may be visually depicted on a cathode ray tube display, as a digital print-out, or as a photograph. 30 claims, 8 figures

  10. PTSD and DNA Methylation in Select Immune Function Gene Promoter Regions: A Repeated Measures Case-control Study of U.S. Military Service Members

    Science.gov (United States)

    2013-06-24

    other relevant exposures which may influ- ence DNA methylation , such as dietary factors ( folate , vitamin B12 intake) (Fenech, 2001; Piyathilake and...ARTICLE published: 24 June 2013 doi: 10.3389/fpsyt.2013.00056 PTSD and DNA methylation in select immune function gene promoter regions: a repeated measures...largely unknown. Dis- tinct expression signatures for PTSD have been found, in particular for immune activation transcripts. DNA methylation may be

  11. Effects of annealing on the sensitivity of LiF TLD-100 after repeated use for low dose measurements

    International Nuclear Information System (INIS)

    Ogunleye, O.T.; Richmond, R.G.

    1987-01-01

    The changes in sensitivity of LiF TLD-100 extruded ribbons subjected to repeated use up to 100 times were investigated. Three different annealing regimes were compared. The dosemeters were annealed at 400 0 C followed by (i) a slow or (ii) fast cooling to room temperature or (iii) utilising a 20 s readout process in the reader without a high temperature annealing at 400 0 C. Each of the three groups consisted of two sets of 20 chips each, with one set receiving 500 μ Gy of 90 Sr beta radiation and the other unirradiated. Sensitivity evaluations were performed every five cycles through the first 50 cycles, and on each tenth cycle thereafter. On the average, the fast cooled group maintained their integrity best, while a maximum variation in sensitivity of about 15% was observed in the irradiated set of the slowly cooled group. A permanent increase in sensitivity of at least 10% was observed for the set of dosemeters receiving radiation without annealing. Glow curve analyses showed an increase in the ratio of peaks 4 and 5 with repeated use of this group. (author)

  12. Method for measuring deuterium in erbium deuteride films

    International Nuclear Information System (INIS)

    Brangan, J.R.; Thornberg, S.M.; Keenan, M.R.

    1997-09-01

    Determining the quantity of deuterium in an erbium deuteride (ErD 2 ) film is essential for assessing the quality of the hydriding process but is a challenging measurement to make. First, the ideal gas law cannot be applied directly due to high temperature (950 degrees C) and low temperature (25 degrees C) regions in the same manifold. Additionally, the metal hydride does not release all of the deuterium rapidly upon heating and metal evaporation occurs during extended heating periods. Therefore, the method developed must provide a means to compensate for temperature inhomogeneities and the amount of deuterium retained in the metal film while heating for a minimal duration. This paper presents two thermal desorption methods used to evaluate the kinetics and equilibria of the deuterium desorption process at high temperatures (950 degrees C). Of primary concern is the evaluation of the quantity of deuterium remaining in these films at the high temperature. A multiple volume expansion technique provided insight into the kinetics of the deuterium evolution and metal evaporation from the film. Finally a repeated pump-down approach yielded data that indicated approximately 10% of the deuterium is retained in the metal film at 950 degrees C and approximately 1 Torr pressure. When the total moles of deuterium determined by this method were divided by the moles of erbium determined by ICP/AES, nearly stochiometric values of 2:1 were obtained for several erbium dideuteride films. Although this work presents data for erbium and deuterium, these methods are applicable to other metal hydrides as well

  13. Tolerability of the Oscar 2 ambulatory blood pressure monitor among research participants: a cross-sectional repeated measures study

    Directory of Open Access Journals (Sweden)

    Hinderliter Alan L

    2011-04-01

    Full Text Available Abstract Background Ambulatory blood pressure monitoring (ABPM is increasingly used to measure blood pressure (BP in research studies. We examined ease of use, comfort, degree of disturbance, reported adverse effects, factors associated with poor tolerability, and association of poor tolerability with data acquisition of 24-hour ABPM using the Oscar 2 monitor in the research setting. Methods Sixty adults participating in a research study of people with a history of borderline clinic BP reported on their experience with ABPM on two occasions one week apart. Poor tolerability was operationalized as an overall score at or above the 75th percentile using responses to questions adapted from a previously developed questionnaire. In addition to descriptive statistics (means for responses to Likert-scaled "0 to 10" questions and proportions for Yes/No questions, we examined reproducibility of poor tolerability as well as associations with poor tolerability and whether poor tolerability was associated with removal of the monitor or inadequate number of BP measurements. Results The mean ambulatory BP of participants by an initial ABPM session was 148/87 mm Hg. After wearing the monitor the first time, the degree to which the monitor was felt to be cumbersome ranged from a mean of 3.0 to 3.8, depending on whether at work, home, driving, or other times. The most bother was interference with normal sleeping pattern (mean 4.2. Wearers found the monitor straightforward to use (mean 7.5. Nearly 67% reported that the monitor woke them after falling asleep, and 8.6% removed it at some point during the night. Reported adverse effects included pain (32%, skin irritation (37%, and bruising (7%. Those categorized as having poor tolerability (kappa = 0.5 between sessions, p = 0.0003 were more likely to report being in fair/poor health (75% vs 22%, p = 0.01 and have elevated 24-hour BP average (systolic: 28% vs 17%, p = 0.56; diastolic: 30% vs 17%, p = 0.37. They were

  14. A multi-segment foot model based on anatomically registered technical coordinate systems: method repeatability in pediatric feet.

    Science.gov (United States)

    Saraswat, Prabhav; MacWilliams, Bruce A; Davis, Roy B

    2012-04-01

    Several multi-segment foot models to measure the motion of intrinsic joints of the foot have been reported. Use of these models in clinical decision making is limited due to lack of rigorous validation including inter-clinician, and inter-lab variability measures. A model with thoroughly quantified variability may significantly improve the confidence in the results of such foot models. This study proposes a new clinical foot model with the underlying strategy of using separate anatomic and technical marker configurations and coordinate systems. Anatomical landmark and coordinate system identification is determined during a static subject calibration. Technical markers are located at optimal sites for dynamic motion tracking. The model is comprised of the tibia and three foot segments (hindfoot, forefoot and hallux) and inter-segmental joint angles are computed in three planes. Data collection was carried out on pediatric subjects at two sites (Site 1: n=10 subjects by two clinicians and Site 2: five subjects by one clinician). A plaster mold method was used to quantify static intra-clinician and inter-clinician marker placement variability by allowing direct comparisons of marker data between sessions for each subject. Intra-clinician and inter-clinician joint angle variability were less than 4°. For dynamic walking kinematics, intra-clinician, inter-clinician and inter-laboratory variability were less than 6° for the ankle and forefoot, but slightly higher for the hallux. Inter-trial variability accounted for 2-4° of the total dynamic variability. Results indicate the proposed foot model reduces the effects of marker placement variability on computed foot kinematics during walking compared to similar measures in previous models. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. The neutronic method for measuring soil moisture

    International Nuclear Information System (INIS)

    Couchat, Ph.

    1967-01-01

    The three group diffusion theory being chosen as the most adequate method for determining the response of the neutron soil moisture probe, a mathematical model is worked out using a numerical calculation programme with Fortran IV coding. This model is fitted to the experimental conditions by determining the effect of different parameters of measuring device: channel, fast neutron source, detector, as also the soil behaviour under neutron irradiation: absorbers, chemical binding of elements. The adequacy of the model is tested by fitting a line through the image points corresponding to the couples of experimental and theoretical values, for seven media having different chemical composition: sand, alumina, line stone, dolomite, kaolin, sandy loam, calcareous clay. The model chosen gives a good expression of the dry density influence and allows α, β, γ and δ constants to be calculated for a definite soil according to the following relation which gives the count rate of the soil moisture probe: N = (α ρ s +β) H v +γ ρ s + δ. (author) [fr

  16. Measuring sperm backflow following female orgasm: a new method

    Science.gov (United States)

    King, Robert; Dempsey, Maria; Valentine, Katherine A.

    2016-01-01

    Background Human female orgasm is a vexed question in the field while there is credible evidence of cryptic female choice that has many hallmarks of orgasm in other species. Our initial goal was to produce a proof of concept for allowing females to study an aspect of infertility in a home setting, specifically by aligning the study of human infertility and increased fertility with the study of other mammalian fertility. In the latter case - the realm of oxytocin-mediated sperm retention mechanisms seems to be at work in terms of ultimate function (differential sperm retention) while the proximate function (rapid transport or cervical tenting) remains unresolved. Method A repeated measures design using an easily taught technique in a natural setting was used. Participants were a small (n=6), non-representative sample of females. The introduction of a sperm-simulant combined with an orgasm-producing technique using a vibrator/home massager and other easily supplied materials. Results The sperm flowback (simulated) was measured using a technique that can be used in a home setting. There was a significant difference in simulant retention between the orgasm (M=4.08, SD=0.17) and non-orgasm (M=3.30, SD=0.22) conditions; t (5)=7.02, p=0.001. Cohen's d=3.97, effect size r=0.89. This indicates a medium to small effect size. Conclusions This method could allow females to test an aspect of sexual response that has been linked to lowered fertility in a home setting with minimal training. It needs to be replicated with a larger sample size. PMID:27799082

  17. Measuring sperm backflow following female orgasm: a new method

    Directory of Open Access Journals (Sweden)

    Robert King

    2016-10-01

    Full Text Available Background: Human female orgasm is a vexed question in the field while there is credible evidence of cryptic female choice that has many hallmarks of orgasm in other species. Our initial goal was to produce a proof of concept for allowing females to study an aspect of infertility in a home setting, specifically by aligning the study of human infertility and increased fertility with the study of other mammalian fertility. In the latter case - the realm of oxytocin-mediated sperm retention mechanisms seems to be at work in terms of ultimate function (differential sperm retention while the proximate function (rapid transport or cervical tenting remains unresolved. Method: A repeated measures design using an easily taught technique in a natural setting was used. Participants were a small (n=6, non-representative sample of females. The introduction of a sperm-simulant combined with an orgasm-producing technique using a vibrator/home massager and other easily supplied materials. Results: The sperm flowback (simulated was measured using a technique that can be used in a home setting. There was a significant difference in simulant retention between the orgasm (M=4.08, SD=0.17 and non-orgasm (M=3.30, SD=0.22 conditions; t (5=7.02, p=0.001. Cohen's d=3.97, effect size r=0.89. This indicates a medium to small effect size. Conclusions: This method could allow females to test an aspect of sexual response that has been linked to lowered fertility in a home setting with minimal training. It needs to be replicated with a larger sample size.

  18. Repeatability and Reproducibility of Retinal Nerve Fiber Layer Parameters Measured by Scanning Laser Polarimetry with Enhanced Corneal Compensation in Normal and Glaucomatous Eyes.

    Science.gov (United States)

    Ara, Mirian; Ferreras, Antonio; Pajarin, Ana B; Calvo, Pilar; Figus, Michele; Frezzotti, Paolo

    2015-01-01

    To assess the intrasession repeatability and intersession reproducibility of peripapillary retinal nerve fiber layer (RNFL) thickness parameters measured by scanning laser polarimetry (SLP) with enhanced corneal compensation (ECC) in healthy and glaucomatous eyes. One randomly selected eye of 82 healthy individuals and 60 glaucoma subjects was evaluated. Three scans were acquired during the first visit to evaluate intravisit repeatability. A different operator obtained two additional scans within 2 months after the first session to determine intervisit reproducibility. The intraclass correlation coefficient (ICC), coefficient of variation (COV), and test-retest variability (TRT) were calculated for all SLP parameters in both groups. ICCs ranged from 0.920 to 0.982 for intravisit measurements and from 0.910 to 0.978 for intervisit measurements. The temporal-superior-nasal-inferior-temporal (TSNIT) average was the highest (0.967 and 0.946) in normal eyes, while nerve fiber indicator (NFI; 0.982) and inferior average (0.978) yielded the best ICC in glaucomatous eyes for intravisit and intervisit measurements, respectively. All COVs were under 10% in both groups, except NFI. TSNIT average had the lowest COV (2.43%) in either type of measurement. Intervisit TRT ranged from 6.48 to 12.84. The reproducibility of peripapillary RNFL measurements obtained with SLP-ECC was excellent, indicating that SLP-ECC is sufficiently accurate for monitoring glaucoma progression.

  19. Performance Analysis of Measurement Inaccuracies of IMU/GPS on Airborne Repeat-pass Interferometric SAR in the Presence of Squint

    Directory of Open Access Journals (Sweden)

    Deng Yuan

    2014-08-01

    Full Text Available In the MOtion COmpensation (MOCO approach to airborne repeat-pass interferometric Synthetic Aperture Radar (SAR based on motion measurement data, the measurement inaccuracies of Inertial Measurement Unit/Global Positioning System (IMU/GPS and the positioning errors of the target, which may contribute to the residual uncompensated motion errors, affect the imaging result and interferometric measurement. Considering the effects of the two types of error, this paper builds a mathematical model of residual motion errors in presence of squint, and analyzes the effects on the residual motion errors induced by the measurement inaccuracies of IMU/GPS and the positioning errors of the target. In particular, the effects of various measurement inaccuracies of IMU/GPS on interferometric SAR image quality, interferometric phase, and digital elevation model precision are disscussed. Moreover, the paper quantitatively researches the effects of residual motion errors on airborne repeat-pass interferometric SAR through theoretical and simulated analyses and provides theoretical bases for system design and signal processing.

  20. Repeatability of two-dimensional chemical shift imaging multivoxel proton magnetic resonance spectroscopy for measuring human cerebral choline-containing compounds.

    Science.gov (United States)

    Puri, Basant K; Egan, Mary; Wallis, Fintan; Jakeman, Philip

    2018-03-22

    To investigate the repeatability of proton magnetic resonance spectroscopy in the in vivo measurement of human cerebral levels of choline-containing compounds (Cho). Two consecutive scans were carried out in six healthy resting subjects at a magnetic field strength of 1.5 T. On each occasion, neurospectroscopy data were collected from 64 voxels using the same 2D chemical shift imaging (CSI) sequence. The data were analyzed in the same way, using the same software, to obtain the values for each voxel of the ratio of Cho to creatine. The Wilcoxon related-samples signed-rank test, coefficient of variation (CV), repeatability coefficient (RC), and intraclass correlation coefficient (ICC) were used to assess the repeatability. The CV ranged from 2.75% to 33.99%, while the minimum RC was 5.68%. There was excellent reproducibility, as judged by significant ICC values, in 26 voxels. Just three voxels showed significant differences according to the Wilcoxon related-samples signed-rank test. It is therefore concluded that when CSI multivoxel proton neurospectroscopy is used to measure cerebral choline-containing compounds at 1.5 T, the reproducibility is highly acceptable.

  1. Fine-resolution repeat topographic surveying of dryland landscapes using UAS-based structure-from-motion photogrammetry: Assessing accuracy and precision against traditional ground-based erosion measurements

    Science.gov (United States)

    Gillian, Jeffrey K.; Karl, Jason W.; Elaksher, Ahmed; Duniway, Michael C.

    2017-01-01

    Structure-from-motion (SfM) photogrammetry from unmanned aerial system (UAS) imagery is an emerging tool for repeat topographic surveying of dryland erosion. These methods are particularly appealing due to the ability to cover large landscapes compared to field methods and at reduced costs and finer spatial resolution compared to airborne laser scanning. Accuracy and precision of high-resolution digital terrain models (DTMs) derived from UAS imagery have been explored in many studies, typically by comparing image coordinates to surveyed check points or LiDAR datasets. In addition to traditional check points, this study compared 5 cm resolution DTMs derived from fixed-wing UAS imagery with a traditional ground-based method of measuring soil surface change called erosion bridges. We assessed accuracy by comparing the elevation values between DTMs and erosion bridges along thirty topographic transects each 6.1 m long. Comparisons occurred at two points in time (June 2014, February 2015) which enabled us to assess vertical accuracy with 3314 data points and vertical precision (i.e., repeatability) with 1657 data points. We found strong vertical agreement (accuracy) between the methods (RMSE 2.9 and 3.2 cm in June 2014 and February 2015, respectively) and high vertical precision for the DTMs (RMSE 2.8 cm). Our results from comparing SfM-generated DTMs to check points, and strong agreement with erosion bridge measurements suggests repeat UAS imagery and SfM processing could replace erosion bridges for a more synoptic landscape assessment of shifting soil surfaces for some studies. However, while collecting the UAS imagery and generating the SfM DTMs for this study was faster than collecting erosion bridge measurements, technical challenges related to the need for ground control networks and image processing requirements must be addressed before this technique could be applied effectively to large landscapes.

  2. A circular feature-based pose measurement method for metal part grasping

    International Nuclear Information System (INIS)

    Wu, Chenrui; He, Zaixing; Zhang, Shuyou; Zhao, Xinyue

    2017-01-01

    The grasping of circular metal parts such as bearings and flanges is a common task in industry. Limited by low texture and repeated features, the point-feature-based method is not applicable in pose measurement of these parts. In this paper, we propose a novel pose measurement method for grasping circular metal parts. This method is based on cone degradation and involves a monocular camera. To achieve higher measurement accuracy, a position-based visual servoing method is presented to continuously control an eye-in-hand, six-degrees-of-freedom robot arm to grasp the part. The uncertainty of the part’s coordinate frame during the control process is solved by defining a fixed virtual coordinate frame. Experimental results are provided to illustrate the effectiveness of the proposed method and the factors that affect measurement accuracy are analyzed. (paper)

  3. Contemporary methods of body composition measurement

    DEFF Research Database (Denmark)

    Fosbøl, Marie Ø; Zerahn, Bo

    2015-01-01

    elements by in vivo neutron activation analysis, which are regarded as gold standard methods, are also summarized. The choice of a specific method or combination of methods for a particular study depends on various considerations including accuracy, precision, subject acceptability, convenience, cost...... and radiation exposure. The relative advantages and disadvantages of each method are discussed with these considerations in mind....

  4. Ocular surface sensitivity repeatability with Cochet-Bonnet esthesiometer.

    Science.gov (United States)

    Chao, Cecilia; Stapleton, Fiona; Badarudin, Ezailina; Golebiowski, Blanka

    2015-02-01

    To determine the repeatability of ocular surface threshold measurements using the Cochet-Bonnet esthesiometer on the same day and 3 months apart. Two separate studies were conducted to determine the repeatability of ocular surface threshold measurements made on the same day (n = 20 subjects) and 3 months apart (n = 29 subjects). The Cochet-Bonnet esthesiometer was used to measure corneal and inferior conjunctival thresholds using the ascending method of limits. The pressure exerted by the Cochet-Bonnet esthesiometer was determined using an analytical balance, for both the 0.08- and 0.12-mm-diameter filaments. This calibration was then used to convert filament length measurements to pressure. Repeatability was determined using a Bland and Altman analysis. The pressure exerted at each filament length differed between the two filament diameters. The measured pressure also differed from values provided by the manufacturer. Repeatability of threshold measurements at the central cornea was shown to be good, with better repeatability for same-day measurements (coefficient of repeatability [CoR] = ±0.23 g/mm²) than for those 3 months apart (CoR = ±0.52 g/mm²). Threshold measurements at the inferior conjunctiva, in contrast, were poorly repeatable (CoR = ±12.78 g/mm²). Cochet-Bonnet esthesiometry is repeatable when performed on the central cornea on the same day and 3 months apart, but this instrument is not recommended for conjunctival threshold measurements.

  5. Reproducibility of repeated measures of deuterium substituted [11C]L-deprenyl ([11C]L-deprenyl-D2) binding in the human brain

    International Nuclear Information System (INIS)

    Logan, Jean; Fowler, Joanna S.; Volkow, Nora D.; Wang, Gene-Jack; MacGregor, Robert R.; Shea, Colleen

    2000-01-01

    The purpose of this study was to assess the reproducibility of repeated positron emission tomography (PET) measures of brain monoamine oxidase B (MAO B) using deuterium-substituted [ 11 C]L-deprenyl ([ 11 C]L-deprenyl-D2) in normal subjects and to validate the method used for estimating the kinetic constants from the irreversible 3-compartment model applied to the tracer binding. Five normal healthy subjects (age range 23-73 years) each received two PET scans with [ 11 C]L-deprenyl-D2. The time interval between scans was 7-27 days. Time-activity data from eight regions of interest and an arterial plasma input function was used to calculate λk 3 , a model term proportional to MAO B, and K 1 , the plasma to brain transfer constant that is related to blood flow. Linear (LIN) and nonlinear least-squares (NLLSQ) estimation methods were used to calculate the optimum model constants. A comparison of time-activity curves for scan 1 and scan 2 showed that the percent of change for peak uptake varied from -18.5 to 15.0% and that increases and decreases in uptake on scan 2 were associated with increases and decreases in the value of the arterial input of the tracer. Calculation of λk 3 showed a difference between scan 1 and scan 2 in the global value ranging between -6.97 and 4.5% (average -2.1±4.7%). The average percent change for eight brain regions for the five subjects was -2.84±7.07%. Values of λk 3 for scan 1 and scan 2 were highly correlated (r 2 =0.98; p 1 showed a significant correlation between scan 1 and scan 2 (r 2 =0.61; p 11 C]L-deprenyl-D2 varied between scan 1 and scan 2, driven by the differences in arterial tracer input. Application of a 3-compartment model to regional time-activity data and arterial input function yielded λk 3 values for scan 1 and scan 2 with an average difference of -2.84 ± 7.07%. Linear regression applied to values of λk 3 from the LIN and NLLSQ methods validated the use of the linear method for calculating λk 3

  6. Standard-Setting Methods as Measurement Processes

    Science.gov (United States)

    Nichols, Paul; Twing, Jon; Mueller, Canda D.; O'Malley, Kimberly

    2010-01-01

    Some writers in the measurement literature have been skeptical of the meaningfulness of achievement standards and described the standard-setting process as blatantly arbitrary. We argue that standard setting is more appropriately conceived of as a measurement process similar to student assessment. The construct being measured is the panelists'…

  7. Rethinking traditional methods for measuring intellectual capital.

    Science.gov (United States)

    Corso, John A

    2007-01-01

    Historically, approaches to measuring intellectual capital have included both conventional accounting-based measures, such as variants of the market-to-book ratio, and more progressive measures, such as the measurement of intangible assets found in approaches such as the Balanced Scorecard and Human Resource Accounting. As greater emphasis is placed on intellectual capital and its various aspects in the continually growing service and knowledge economy, the use of assessment instruments to inventory the alignment, balance, and variety of intellectual capacities and metrics that assess the effectiveness of succession planning may represent new directions in which organizations can head in the measurement of this important construct.

  8. (In)Consistencies in Responses to Sodium Bicarbonate Supplementation: A Randomised, Repeated Measures, Counterbalanced and Double-Blind Study.

    Science.gov (United States)

    Froio de Araujo Dias, Gabriela; da Eira Silva, Vinicius; de Salles Painelli, Vitor; Sale, Craig; Giannini Artioli, Guilherme; Gualano, Bruno; Saunders, Bryan

    2015-01-01

    Intervention studies do not account for high within-individual variation potentially compromising the magnitude of an effect. Repeat administration of a treatment allows quantification of individual responses and determination of the consistency of responses. We determined the consistency of metabolic and exercise responses following repeated administration of sodium bicarbonate (SB). 15 physically active males (age 25±4 y; body mass 76.0±7.3 kg; height 1.77±0.05 m) completed six cycling capacity tests at 110% of maximum power output (CCT110%) following ingestion of either 0.3 g∙kg-1BM of SB (4 trials) or placebo (PL, 2 trials). Blood pH, bicarbonate, base excess and lactate were determined at baseline, pre-exercise, post-exercise and 5-min post-exercise. Total work done (TWD) was recorded as the exercise outcome. SB supplementation increased blood pH, bicarbonate and base excess prior to every trial (all p ≤ 0.001); absolute changes in pH, bicarbonate and base excess from baseline to pre-exercise were similar in all SB trials (all p > 0.05). Blood lactate was elevated following exercise in all trials (p ≤ 0.001), and was higher in some, but not all, SB trials compared to PL. TWD was not significantly improved with SB vs. PL in any trial (SB1: +3.6%; SB2 +0.3%; SB3: +2.1%; SB4: +6.7%; all p > 0.05), although magnitude-based inferences suggested a 93% likely improvement in SB4. Individual analysis showed ten participants improved in at least one SB trial above the normal variation of the test although five improved in none. The mechanism for improved exercise with SB was consistently in place prior to exercise, although this only resulted in a likely improvement in one trial. SB does not consistently improve high intensity cycling capacity, with results suggesting that caution should be taken when interpreting the results from single trials as to the efficacy of SB supplementation. ClinicalTrials.gov NCT02474628.

  9. (InConsistencies in Responses to Sodium Bicarbonate Supplementation: A Randomised, Repeated Measures, Counterbalanced and Double-Blind Study.

    Directory of Open Access Journals (Sweden)

    Gabriela Froio de Araujo Dias

    Full Text Available Intervention studies do not account for high within-individual variation potentially compromising the magnitude of an effect. Repeat administration of a treatment allows quantification of individual responses and determination of the consistency of responses. We determined the consistency of metabolic and exercise responses following repeated administration of sodium bicarbonate (SB.15 physically active males (age 25±4 y; body mass 76.0±7.3 kg; height 1.77±0.05 m completed six cycling capacity tests at 110% of maximum power output (CCT110% following ingestion of either 0.3 g∙kg-1BM of SB (4 trials or placebo (PL, 2 trials. Blood pH, bicarbonate, base excess and lactate were determined at baseline, pre-exercise, post-exercise and 5-min post-exercise. Total work done (TWD was recorded as the exercise outcome.SB supplementation increased blood pH, bicarbonate and base excess prior to every trial (all p ≤ 0.001; absolute changes in pH, bicarbonate and base excess from baseline to pre-exercise were similar in all SB trials (all p > 0.05. Blood lactate was elevated following exercise in all trials (p ≤ 0.001, and was higher in some, but not all, SB trials compared to PL. TWD was not significantly improved with SB vs. PL in any trial (SB1: +3.6%; SB2 +0.3%; SB3: +2.1%; SB4: +6.7%; all p > 0.05, although magnitude-based inferences suggested a 93% likely improvement in SB4. Individual analysis showed ten participants improved in at least one SB trial above the normal variation of the test although five improved in none.The mechanism for improved exercise with SB was consistently in place prior to exercise, although this only resulted in a likely improvement in one trial. SB does not consistently improve high intensity cycling capacity, with results suggesting that caution should be taken when interpreting the results from single trials as to the efficacy of SB supplementation.ClinicalTrials.gov NCT02474628.

  10. Aortic blood flow subtraction: an alternative method for measuring total renal blood flow in conscious dogs

    DEFF Research Database (Denmark)

    Sandgaard, N C F; Andersen, J L; Holstein-Rathlou, N-H

    2002-01-01

    We have measured total renal blood flow (TRBF) as the difference between signals from ultrasound flow probes implanted around the aorta above and below the renal arteries. The repeatability of the method was investigated by repeated, continuous infusions of angiotensin II and endothelin-1 seven...... arterial blood pressure by 49% and decreased TRBF by 12%, providing an increase in renal vascular resistance of 69%. Dynamic analysis showed autoregulation of renal blood flow in the frequency range ... of TRBF by aortic blood flow subtraction is a practical and reliable method that allows direct comparison of excretory function and renal blood flow from two kidneys. The method also allows direct comparison between TRBF and flow in the caudal aorta....

  11. Repeatability study of replicate crash tests: A signal analysis approach.

    Science.gov (United States)

    Seppi, Jeremy; Toczyski, Jacek; Crandall, Jeff R; Kerrigan, Jason

    2017-10-03

    To provide an objective basis on which to evaluate the repeatability of vehicle crash test methods, a recently developed signal analysis method was used to evaluate correlation of sensor time history data between replicate vehicle crash tests. The goal of this study was to evaluate the repeatability of rollover crash tests performed with the Dynamic Rollover Test System (DRoTS) relative to other vehicle crash test methods. Test data from DRoTS tests, deceleration rollover sled (DRS) tests, frontal crash tests, frontal offset crash tests, small overlap crash tests, small overlap impact (SOI) crash tests, and oblique crash tests were obtained from the literature and publicly available databases (the NHTSA vehicle database and the Insurance Institute for Highway Safety TechData) to examine crash test repeatability. Signal analysis of the DRoTS tests showed that force and deformation time histories had good to excellent repeatability, whereas vehicle kinematics showed only fair repeatability due to the vehicle mounting method for one pair of tests and slightly dissimilar mass properties (2.2%) in a second pair of tests. Relative to the DRS, the DRoTS tests showed very similar or higher levels of repeatability in nearly all vehicle kinematic data signals with the exception of global X' (road direction of travel) velocity and displacement due to the functionality of the DRoTS fixture. Based on the average overall scoring metric of the dominant acceleration, DRoTS was found to be as repeatable as all other crash tests analyzed. Vertical force measures showed good repeatability and were on par with frontal crash barrier forces. Dynamic deformation measures showed good to excellent repeatability as opposed to poor repeatability seen in SOI and oblique deformation measures. Using the signal analysis method as outlined in this article, the DRoTS was shown to have the same or better repeatability of crash test methods used in government regulatory and consumer evaluation test

  12. Current lung water measurement methods in man

    International Nuclear Information System (INIS)

    Basset, G.; Moreau, F.; Marsac, J.; Capitini, R.; Botter, F.

    1979-01-01

    Two kinds of tracer method are used to estimate the lung water pools differing by the tracer intake and the sector observed. Airborne intake gives an estimate of the tissues irrigated by the lung and bronchial circulation, whereas vascular intake only shows the sectors perfused by the lung flow. Either of these methods is suitable for a general or regional analysis. In general methods the tracer is followed at the lung exit on expired air for the first method, on peripheral arterial blood for the second. Regional methods imply partial or whole-lung external detection systems [fr

  13. Fixed-flexion knee radiography using a new positioning device produced highly repeatable measurements of joint space width: ELSA-Brasil Musculoskeletal Study (ELSA-Brasil MSK).

    Science.gov (United States)

    Telles, Rosa Weiss; Costa-Silva, Luciana; Machado, Luciana A C; Reis, Rodrigo Citton Padilha Dos; Barreto, Sandhi Maria

    To describe the performance of a non-fluoroscopic fixed-flexion PA radiographic protocol with a new positioning device, developed for the assessment of knee osteoarthritis (OA) in Brazilian Longitudinal Study of Adult Health Musculoskeletal Study (ELSA-Brasil MSK). A test-retest design including 19 adults (38 knee images) was conducted. Feasibility of the radiographic protocol was assessed by image quality parameters and presence of radioanatomic alignment according to intermargin distance (IMD) values. Repeatability was assessed for IMD and joint space width (JSW) measured at three different locations. Approximately 90% of knee images presented excellent quality. Frequencies of nearly perfect radioanatomic alignment (IMD ≤1mm) ranged from 29% to 50%, and satisfactory alignment was found in up to 71% and 76% of the images (IMD ≤1.5mm and ≤1.7mm, respectively). Repeatability analyses yielded the following results: IMD [SD of mean difference=1.08; coefficient of variation (%CV)=54.68%; intraclass correlation coefficient (ICC) (95%CI)=0.59 (0.34-0.77)]; JSW [SD of mean difference=0.34-0.61; %CV=4.48%-9.80%; ICC (95%CI)=0.74 (0.55-0.85)-0.94 (0.87-0.97)]. Adequately reproducible measurements of IMD and JSW were found in 68% and 87% of the images, respectively. Despite the difficulty in achieving consistent radioanatomic alignment between subsequent radiographs in terms of IMD, the protocol produced highly repeatable JSW measurements when these were taken at midpoint and 10mm from the medial extremity of the medial tibial plateau. Therefore, measurements of JSW at these locations can be considered adequate for the assessment of knee OA in ELSA-Brasil MSK. Copyright © 2016. Published by Elsevier Editora Ltda.

  14. Shadow photography method for beam emittance measurement

    International Nuclear Information System (INIS)

    Kashkovskij, V.V.; Lisin, V.A.

    1988-01-01

    Improved technique of shadow photography which allows to measure rather simply and accurately the angular distribution of electrons extracted from betatron is described. Measurement accuracy of particle flight angles is determined by setting of rods relatively to the plane of photographic paper sheet, their diameter and shadow trace length. Incidental angle deviation of rod axes contributes mainly into the error. Mean root-square error constituted 2-3% according to the results of several measurements of angles

  15. Superconducting property measuring system by magnetization method

    International Nuclear Information System (INIS)

    Ikisawa, K.; Mori, T.; Takasu, N.

    1988-01-01

    Superconducting property measuring system (CMS-370B) for high temperature oxide superconductor has been developed. This system adopts magnetization measurement. The superconducting properties are able to be measured automatically and continuously changing the temperature and external magnetic field. The critical current density as a function of temperature and magnetic field of high temperature superconductor YBa 2 Cu 3 O 7-y (YBCO) has been measured. This paper reports how it was confirmed that this system having the high performance and the accuracy gave the significant contribution to the superconducting material development

  16. Simplified method for measuring the response time of scram release electromagnet in a nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Patri, Sudheer, E-mail: patri@igcar.gov.in; Mohana, M.; Kameswari, K.; Kumar, S. Suresh; Narmadha, S.; Vijayshree, R.; Meikandamurthy, C.; Venkatesan, A.; Palanisami, K.; Murthy, D. Thirugnana; Babu, B.; Prakash, V.; Rajan, K.K.

    2015-04-15

    Highlights: • An alternative method for estimating the electromagnet clutch release time. • A systematic approach to develop a computer based measuring system. • Prototype tests on the measurement system. • Accuracy of the method is ±6% and repeatability error is within 2%. - Abstract: The delay time in electromagnet clutch release during a reactor trip (scram action) is an important safety parameter, having a bearing on the plant safety during various design basis events. Generally, it is measured using current decay characteristics of electromagnet coil and its energising circuit. A simplified method of measuring the same in a Sodium cooled fast reactors (SFR) is proposed in this paper. The method utilises the position data of control rod to estimate the delay time in electromagnet clutch release. A computer based real time measurement system for measuring the electromagnet clutch delay time is developed and qualified for retrofitting in prototype fast breeder reactor. Various stages involved in the development of the system are principle demonstration, experimental verification of hardware capabilities and prototype system testing. Tests on prototype system have demonstrated the satisfactory performance of the system with intended accuracy and repeatability.

  17. Direct measurement of tritium in urine by liquid scintillation method

    International Nuclear Information System (INIS)

    Zhang Caihong; Wen Qinghua; Chen Kefei; Li Huaixin

    1999-01-01

    The author introduces the method for direct measurement of tritium concentration in urine using liquid scintillation. Effects of sampling containers, store patterns and storage time are studied. Meanwhile, results of two methods are compared with direct measurement method and oxidation distillation method. The results shows that direct measurement method is a economic and simple method, which can meet the need of determination of urine tritium for NPP workers. There is no significant difference compared with the data obtained by oxidation distillation method

  18. Mapping Mixed Methods Research: Methods, Measures, and Meaning

    Science.gov (United States)

    Wheeldon, J.

    2010-01-01

    This article explores how concept maps and mind maps can be used as data collection tools in mixed methods research to combine the clarity of quantitative counts with the nuance of qualitative reflections. Based on more traditional mixed methods approaches, this article details how the use of pre/post concept maps can be used to design qualitative…

  19. Tundish Cover Flux Thickness Measurement Method and Instrumentation Based on Computer Vision in Continuous Casting Tundish

    Directory of Open Access Journals (Sweden)

    Meng Lu

    2013-01-01

    Full Text Available Thickness of tundish cover flux (TCF plays an important role in continuous casting (CC steelmaking process. Traditional measurement method of TCF thickness is single/double wire methods, which have several problems such as personal security, easily affected by operators, and poor repeatability. To solve all these problems, in this paper, we specifically designed and built an instrumentation and presented a novel method to measure the TCF thickness. The instrumentation was composed of a measurement bar, a mechanical device, a high-definition industrial camera, a Siemens S7-200 programmable logic controller (PLC, and a computer. Our measurement method was based on the computer vision algorithms, including image denoising method, monocular range measurement method, scale invariant feature transform (SIFT, and image gray gradient detection method. Using the present instrumentation and method, images in the CC tundish can be collected by camera and transferred to computer to do imaging processing. Experiments showed that our instrumentation and method worked well at scene of steel plants, can accurately measure the thickness of TCF, and overcome the disadvantages of traditional measurement methods, or even replace the traditional ones.

  20. Method of measuring distance between fuel element

    International Nuclear Information System (INIS)

    Urata, Megumu.

    1991-01-01

    The distance between fuel elements contained in a pool is measured in a contactless manner even for a narrow distance less than 1 mm. That is, the equipment for measuring the distance between spent fuel elements of a spent fuel assembly in a nuclear reactor comprises a optical fiber scope, a lens, an industrial TV camera and a monitor TV. The top end of the optical fiber scope is inserted between fuel elements to be measured. The state thereof is displayed on the TV screen to measure the distance between the fuel elements. The measured results are compared with a previously formed calibration curve to determine the value between the fuel elements. Then, the distance between the fuel elements can be determined in the pool of a power plant without dismantling the fuel assembly, to investigate the state of the bending and estimate the fuel working life. (I.S.)

  1. Umbilical cord Wharton's jelly repeated culture system: a new device and method for obtaining abundant mesenchymal stem cells for bone tissue engineering.

    Directory of Open Access Journals (Sweden)

    Zhengqi Chang

    Full Text Available To date, various types of cells for seeding regenerative scaffolds have been used for bone tissue engineering. Among seed cells, the mesenchymal stem cells derived from human umbilical cord Wharton's jelly (hUCMSCs represent a promising candidate and hold potential for bone tissue engineering due to the the lack of ethical controversies, accessibility, sourced by non-invasive procedures for donors, a reduced risk of contamination, osteogenic differentiation capacities, and higher immunomodulatory capacity. However, the current culture methods are somewhat complicated and inefficient and often fail to make the best use of the umbilical cord (UC tissues. Moreover, these culture processes cannot be performed on a large scale and under strict quality control. As a result, only a small quantity of cells can be harvested using the current culture methods. To solve these problems, we designed and evaluated an UC Wharton's jelly repeated culture device. Using this device, hUCMSCs were obtained from the repeated cultures and their quantities and biological characteristics were compared. We found that using our culture device, which retained all tissue blocks on the bottom of the dish, the total number of obtained cells increased 15-20 times, and the time required for the primary passage was reduced. Moreover, cells harvested from the repeated cultures exhibited no significant difference in their immunophenotype, potential for multilineage differentiation, or proliferative, osteoinductive capacities, and final osteogenesis. The application of the repeated culture frame (RCF not only made full use of the Wharton's jelly but also simplified and specified the culture process, and thus, the culture efficiency was significantly improved. In summary, abundant hUCMSCs of dependable quality can be acquired using the RCF.

  2. Measurement of absolute displacement-amplitude of ultrasonic wave using piezo-electric detection method

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seong Hyun; Kim, Jong Beom; Jhang, Kyung Young [Hanyang University, Seoul (Korea, Republic of)

    2017-02-15

    A nonlinear ultrasonic parameter is defined by the ratio of displacement amplitude of the fundamental frequency component to that of the second-order harmonic frequency component. In this study, the ultrasonic displacement amplitude of an SUS316 specimen was measured via a piezo-electric-based method to identify the validity of piezo-electric detection method. For comparison, the ultrasonic displacement was also determined via a laser-based Fabry-Pérot interferometer. The experimental results for both measurements were in good agreement. Additionally, the stability of the repeated test results from the piezo-electric method exceeded that of the laser-interferometric method. This result indicated that the piezo-electric detection method can be utilized to measure a nonlinear ultrasonic parameter due to its excellent stability although it involves a complicated process.

  3. Measurement of absolute displacement-amplitude of ultrasonic wave using piezo-electric detection method

    International Nuclear Information System (INIS)

    Park, Seong Hyun; Kim, Jong Beom; Jhang, Kyung Young

    2017-01-01

    A nonlinear ultrasonic parameter is defined by the ratio of displacement amplitude of the fundamental frequency component to that of the second-order harmonic frequency component. In this study, the ultrasonic displacement amplitude of an SUS316 specimen was measured via a piezo-electric-based method to identify the validity of piezo-electric detection method. For comparison, the ultrasonic displacement was also determined via a laser-based Fabry-Pérot interferometer. The experimental results for both measurements were in good agreement. Additionally, the stability of the repeated test results from the piezo-electric method exceeded that of the laser-interferometric method. This result indicated that the piezo-electric detection method can be utilized to measure a nonlinear ultrasonic parameter due to its excellent stability although it involves a complicated process

  4. The reliability of repeated TMS measures in older adults and in patients with subacute and chronic stroke

    Directory of Open Access Journals (Sweden)

    Heidi M. Schambra

    2015-09-01

    Full Text Available The reliability of transcranial magnetic stimulation (TMS measures in healthy older adults and stroke patients has been insufficiently characterized. We determined whether common TMS measures could reliably evaluate change in individuals and in groups using the smallest detectable change (SDC, or could tell subjects apart using the intraclass correlation coefficient (ICC. We used a single-rater test-retest design in older healthy, subacute stroke, and chronic stroke subjects. At twice daily sessions on two consecutive days, we recorded resting motor threshold, test stimulus intensity, recruitment curves, short-interval intracortical inhibition and facilitation, and long-interval intracortical inhibition. Using variances estimated from a random effects model, we calculated the SDC and ICC for each TMS measure. For all TMS measures in all groups, SDCs for single subjects were large; only with modest group sizes did the SDCs become low. Thus, while these TMS measures cannot be reliably used as a biomarker to detect individual change, they can reliably detect change exceeding measurement noise in moderate-sized groups. For several of the TMS measures, ICCs were universally high, suggesting that they can reliably discriminate between subjects. Though most TMS measures have sufficient reliability in particular contexts, work establishing their validity, responsiveness, and clinical relevance is still needed.

  5. Evaluation of different field methods for measuring soil water infiltration

    Science.gov (United States)

    Pla-Sentís, Ildefonso; Fonseca, Francisco

    2010-05-01

    soil before and during the measurement. Due to the commonly found high variability, natural or induced by land management, of the soil surface and subsurface hydrological properties, and to the limitations imposed by the requirements of water for the measurements, there is proposed a simple and handy method, which do not use high volumes of water, adaptable to very different soil and land conditions, and that allow many repeated measurements with acceptable accuracy for most of the purposes. References Pla, I., 1997. A soil water balance model for monitoring soil erosion processes and effects on steep lands in the tropics. Soil Technology. 11(1):17-30. Elsevier Pla, I., 2006. Hydrological approach for assessing desertification processes in the Mediterranean region. In W.G. Kepner et al. (Editors), Desertification in the Mediterranean Region. A Security Issue. 579-600 Springer. Heidelberg (Germany) Reynolds W.D., B.T. Bowman, R.R. Brunke, C.F. Drury and C.S. Tan. 2000. Comparison of Tension Infiltrometer, Pressure Infiltrometer, and Soil Core Estimates of Saturated Hydraulic Conductivity . Soil Science Society of America Journal 64:478-484 Segal, E., S.A.Bradford, P. Shouse; N. Lazarovich, and D. Corwin. 2008. Integration of Hard and Soft Data to Characterize Field-Scale Hydraulic Properties for Flow and Transport Studies. Vadose Zone J 7:878-889 Young, E. 1991. Infiltration measurements, a review. Hydrological processes 5: 309-320.

  6. IMPLANTABLE RESONATORS – A TECHNIQUE FOR REPEATED MEASUREMENT OF OXYGEN AT MULTIPLE DEEP SITES WITH IN VIVO EPR

    Science.gov (United States)

    Li, Hongbin; Hou, Huagang; Sucheta, Artur; Williams, Benjamin B.; Lariviere, Jean P.; Khan, Nadeem; Lesniewski, Piotr N.; Swartz, Harold M.

    2013-01-01

    EPR oximetry using implantable resonators allow measurements at much deeper sites than are possible with surface resonators (> 80 mm vs. 10 mm) and have greater sensitivity at any depth. We report here the development of an improvement of the technique that now enables us to obtain the information from multiple sites and at a variety of depths. The measurements from the various sites are resolved using a simple magnetic field gradient. In the rat brain multi-probe implanted resonators measured pO2 at several sites simultaneously for over 6 months to record under normoxic, hypoxic and hyperoxic conditions. This technique also facilitates measurements in moving parts of the animal such as the heart, because the orientation of the paramagnetic material relative to the sensitive small loop is not altered by the motion. The measured response is very fast, enabling measurements in real time of physiological and pathological changes such as experimental cardiac ischemia in the mouse heart. The technique also is quite useful for following changes in tumor pO2, including applications with simultaneous measurements in tumors and adjacent normal tissues. PMID:20204802

  7. A novel method to measure femoral component migration by computed tomography: a cadaver study.

    Science.gov (United States)

    Boettner, Friedrich; Sculco, Peter; Lipman, Joseph; Renner, Lisa; Faschingbauer, Martin

    2016-06-01

    Radiostereometric analysis (RSA) is the most accurate technique to measure implant migration. However, it requires special equipment, technical expertise and analysis software and has not gained wide acceptance. The current paper analyzes a novel method to measure implant migration utilizing widely available computer tomography (CT). Three uncemented total hip replacements were performed in three human cadavers and six tantalum beads were inserted into the femoral bone similar to RSA. Six different 28 mm heads (-3, 0, 2.5, 5.0, 7.5 and 10 mm) were added to simulate five reproducible translations (maximum total point migration) of the center of the head. Implant migration was measured in a 3-D analysis software (Geomagic Studio 7). Repeat manual reconstructions of the center of the head were performed by two investigators to determine repeatability and accuracy. The accuracy of measurements between the centers of two head sizes was 0.11 mm with a CI 95 % of 0.22 mm. The intra-observer repeatability was 0.13 mm (CI 95 % 0.25 mm). The interrater-reliability was 0.943. CT based measurement of head displacement in a cadaver model were highly accurate and reproducible.

  8. Arterial endothelial function measurement method and apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Maltz, Jonathan S; Budinger, Thomas F

    2014-03-04

    A "relaxoscope" (100) detects the degree of arterial endothelial function. Impairment of arterial endothelial function is an early event in atherosclerosis and correlates with the major risk factors for cardiovascular disease. An artery (115), such as the brachial artery (BA) is measured for diameter before and after several minutes of either vasoconstriction or vasorelaxation. The change in arterial diameter is a measure of flow-mediated vasomodification (FMVM). The relaxoscope induces an artificial pulse (128) at a superficial radial artery (115) via a linear actuator (120). An ultrasonic Doppler stethoscope (130) detects this pulse 10-20 cm proximal to the point of pulse induction (125). The delay between pulse application and detection provides the pulse transit time (PTT). By measuring PTT before (160) and after arterial diameter change (170), FMVM may be measured based on the changes in PTT caused by changes in vessel caliber, smooth muscle tone and wall thickness.

  9. A Novel Method for Short Distance Measurements

    International Nuclear Information System (INIS)

    Fernandez, M.G.; Ferrando, A.; Josa, M.I.; Molinero, A.; Oller, J.C.; Arce, P.; Calvo, E.; Figueroa, C.F.; Garcia, C.F.; Rodigrido, T.; Vila, I.; Virto, A.L.

    1998-01-01

    A new, accurate and un expensive device for measuring short distances, intended for monitoring in LHC experiments is presented. Data taken with a very simple prototype are shown and performance is extracted. (Author) 4 refs

  10. Complementary methods of transverse emittance measurement

    Energy Technology Data Exchange (ETDEWEB)

    Zagel, James; Hu, Martin; Jansson, Andreas; Thurman-Keup, Randy; Yan, Ming-Jen; /Fermilab

    2008-05-01

    Several complementary transverse emittance monitors have been developed and used at the Fermilab accelerator complex. These include Ionization profile Monitors (IPM), Flying Wires, Schottky detectors and a Synchrotron Light Monitor (Synchlite). Mechanical scrapers have also been used for calibration purposes. This paper describes the various measurement devices by examining their basic features, calibration requirements, systematic uncertainties, and applications to collider operation. A comparison of results from different kinds of measurements is also presented.

  11. Method and device for measuring fluid flow

    International Nuclear Information System (INIS)

    Atherton, R.; Marinkovich, P.S.; Spadaro, P.R.; Stout, J.W.

    1976-01-01

    The invention is a fluid flow measuring device for determining the coolant flow at the entrance to a specific nuclear reactor fuel region. The device comprises a plurality of venturis having the upstream inlet and throat pressure of each respectively manifolded together to provide one static pressure signal for each region monitored. The device provides accurate flow measurement with low pressure losses and uniform entrance and discharge flow distribution. 1 claim, 7 figures

  12. Repeatability of riparian vegetation sampling methods: how useful are these techniques for broad-scale, long-term monitoring?

    Science.gov (United States)

    Marc C. Coles-Ritchie; Richard C. Henderson; Eric K. Archer; Caroline Kennedy; Jeffrey L. Kershner

    2004-01-01

    Tests were conducted to evaluate variability among observers for riparian vegetation data collection methods and data reduction techniques. The methods are used as part of a largescale monitoring program designed to detect changes in riparian resource conditions on Federal lands. Methods were evaluated using agreement matrices, the Bray-Curtis dissimilarity metric, the...

  13. Repeated measurements of NT-pro-B-type natriuretic peptide, troponin T or C-reactive protein do not predict future allograft rejection in heart transplant recipients.

    Science.gov (United States)

    Battes, Linda C; Caliskan, Kadir; Rizopoulos, Dimitris; Constantinescu, Alina A; Robertus, Jan L; Akkerhuis, Martijn; Manintveld, Olivier C; Boersma, Eric; Kardys, Isabella

    2015-03-01

    Studies on the prognostic value of serial biomarker assays for future occurrence of allograft rejection (AR) are scarce. We examined whether repeated measurements of NT-pro-B-type natriuretic peptide (NT-proBNP), troponin T (TropT) and C-reactive protein (CRP) predict AR. From 2005 to 2010, 77 consecutive heart transplantation (HTx) recipients were included. The NT-proBNP, TropT, and CRP were measured at 16 ± 4 (mean ± standard deviation) consecutive routine endomyocardial biopsy surveillance visits during the first year of follow-up. Allograft rejection was defined as International Society for Heart and Lung Transplantation (ISHLT) grade 2R or higher at endomyocardial biopsy. Joint modeling was used to assess the association between repeated biomarker measurements and occurrence of future AR. Joint modeling accounts for dependence among repeated observations in individual patients. The mean age of the patients at HTx was 49 ± 9.2 years, and 68% were men. During the first year of follow-up, 1,136 biopsies and concurrent blood samples were obtained, and 56 patients (73%) experienced at least one episode of AR. All biomarkers were elevated directly after HTx and achieved steady-state after ∼ 12 weeks, both in patients with or without AR. No associations were present between the repeated measurements of NT-proBNP, TropT, or CRP and AR both early (weeks 0-12) and late (weeks 13-52) in the course after HTx (hazard ratios for weeks 13-52: 0.96 (95% confidence interval, 0.55-1.68), 0.67 (0.27-1.69), and 1.44 (0.90-2.30), respectively, per ln[unit]). Combining the three biomarkers in one model also rendered null results. The temporal evolution of NT-proBNP, TropT, and CRP before AR did not predict occurrence of acute AR both in the early and late course of the first year after HTx.

  14. Dimension measuring method for channel box

    International Nuclear Information System (INIS)

    Jo, Hiroto.

    1995-01-01

    The device of the present invention concerns detection of a channel box for spent fuel assemblies of a BWR type reactor, which measures a cross sectional shape and dimension of the channel box to check deformation amount such as expansion. That is, a customary fuel exchanger and a dimension measuring device are used. The lower end of the channel box is measured by a distance sensor of the dimension measuring device when it is aligned with a position of the distance sensor. The channel box is lowered at the same time while detecting axial position data of the fuel exchanger. The position of the channel box in an axial direction is detected based on axial position data of the fuel exchanger. The lower end of the channel box can accurately be recognized by the detection of both of them. Subsequent deformation measurement for the channel box at accurate axial positions is enabled. In addition, since the axial position data of the fuel exchanger per se are detected, an axial profile of the channel box can be measured even if a lifting speed of the channel box is varied on every region. (I.S.)

  15. A New Measurement Method of Iimage Encryption

    International Nuclear Information System (INIS)

    Yu, X Y; Zhang, J; Ren, H E; Li, S; Zhang, X D

    2006-01-01

    Image scrambling transformation is applied widely in the digital watermarking and image encryption. Although more and more scrambling algorithms appear, they lack a method to evaluate the image scrambling degree. According to the relative differences of a point and adjacent point in scrambling front and back, a new method which judges the scrambling degree is proposed. Not only it can evaluate the change of each pixel's position, but also evaluate the change of adjacent pixel's value. Apply Matlab to the simulation experiment, the result indicated that this method can evaluate image scrambling degree well, and it accorded with people's vision too

  16. Discontinuous Patterns of Cigarette Smoking From Ages 18 to 50 in the United States: A Repeated-Measures Latent Class Analysis.

    Science.gov (United States)

    Terry-McElrath, Yvonne M; O'Malley, Patrick M; Johnston, Lloyd D

    2017-12-13

    Effective cigarette smoking prevention and intervention programming is enhanced by accurate understanding of developmental smoking pathways across the life span. This study investigated within-person patterns of cigarette smoking from ages 18 to 50 among a US national sample of high school graduates, focusing on identifying ages of particular importance for smoking involvement change. Using data from approximately 15,000 individuals participating in the longitudinal Monitoring the Future study, trichotomous measures of past 30-day smoking obtained at 11 time points were modeled using repeated-measures latent class analyses. Sex differences in latent class structure and membership were examined. Twelve latent classes were identified: three characterized by consistent smoking patterns across age (no smoking; smoking developing effective smoking prevention and intervention programming. This study examined cigarette smoking among a national longitudinal US sample of high school graduates from ages 18 to 50 and identified distinct latent classes characterized by patterns of movement between no cigarette use, light-to-moderate smoking, and the conventional definition of heavy smoking at 11 time points via repeated-measures latent class analysis. Membership probabilities for each smoking class were estimated, and critical ages of susceptibility to change in smoking behaviors were identified. © The Author 2017. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Method and apparatus for measuring electromagnetic radiation

    Science.gov (United States)

    Been, J. F. (Inventor)

    1973-01-01

    An apparatus and method are described in which the capacitance of a semiconductor junction subjected to an electromagnetic radiation field is utilized to indicate the intensity or strength of the radiation.

  18. Methods to measure stability of dental implants

    Directory of Open Access Journals (Sweden)

    Shruti Digholkar

    2014-01-01

    Full Text Available Dental implant treatment is an excellent option for prosthetic restoration that is associated with high success rates. Implant stability is essential for a good outcome. The clinical assessment of osseointegration is based on mechanical stability rather than histological criteria, considering primary stability (absence of mobility in bone bed after implant insertion and secondary stability (bone formation and remodeling at implant-bone interface. However, due to the invasive nature of the histological methods various other methods have been proposed: Radiographs, the surgeon′s perception, Insertion torque (cutting torque analysis, seating torque, reverse torque testing, percussion testing, impact hammer method, pulsed oscillation waveform, implant mobility checker, Periotest, resonance frequency analysis. This review focuses on the methods currently available for the evaluation of implant stability.

  19. Chemical Method of Urine Volume Measurement

    Science.gov (United States)

    Petrack, P.

    1967-01-01

    A system has been developed and qualified as flight hardware for the measurement of micturition volumes voided by crewmen during Gemini missions. This Chemical Urine Volume Measurement System (CUVMS) is used for obtaining samples of each micturition for post-flight volume determination and laboratory analysis for chemical constituents of physiological interest. The system is versatile with respect to volumes measured, with a capacity beyond the largest micturition expected to be encountered, and with respect to mission duration of inherently indefinite length. The urine sample is used for the measurement of total micturition volume by a tracer dilution technique, in which a fixed, predetermined amount of tritiated water is introduced and mixed into the voided urine, and the resulting concentration of the tracer in the sample is determined with a liquid scintillation spectrometer. The tracer employed does not interfere with the analysis for the chemical constituents of the urine. The CUVMS hardware consists of a four-way selector valve in which an automatically operated tracer metering pump is incorporated, a collection/mixing bag, and tracer storage accumulators. The assembled system interfaces with a urine receiver at the selector valve inlet, sample bags which connect to the side of the selector valve, and a flexible hose which carries the excess urine to the overboard drain connection. Results of testing have demonstrated system volume measurement accuracy within the specification limits of +/-5%, and operating reliability suitable for system use aboard the GT-7 mission, in which it was first used.

  20. A Simple Method to Decode the Complete 18-5.8-28S rRNA Repeated Units of Green Algae by Genome Skimming.

    Science.gov (United States)

    Lin, Geng-Ming; Lai, Yu-Heng; Audira, Gilbert; Hsiao, Chung-Der

    2017-11-06

    Green algae, Chlorella ellipsoidea , Haematococcus pluvialis and Aegagropila linnaei (Phylum Chlorophyta) were simultaneously decoded by a genomic skimming approach within 18-5.8-28S rRNA region. Whole genomic DNAs were isolated from green algae and directly subjected to low coverage genome skimming sequencing. After de novo assembly and mapping, the size of complete 18-5.8-28S rRNA repeated units for three green algae were ranged from 5785 to 6028 bp, which showed high nucleotide diversity (π is around 0.5-0.6) within ITS1 and ITS2 (Internal Transcribed Spacer) regions. Previously, the evolutional diversity of algae has been difficult to decode due to the inability design universal primers that amplify specific marker genes across diverse algal species. In this study, our method provided a rapid and universal approach to decode the 18-5.8-28S rRNA repeat unit in three green algal species. In addition, the completely sequenced 18-5.8-28S rRNA repeated units provided a solid nuclear marker for phylogenetic and evolutionary analysis for green algae for the first time.

  1. A keyboard control method for loop measurement

    International Nuclear Information System (INIS)

    Gao, Z.W.

    1994-01-01

    This paper describes a keyboard control mode based on the DEC VAX computer. The VAX Keyboard code can be found under running of a program was developed. During the loop measurement or multitask operation, it ables to be distinguished from a keyboard code to stop current operation or transfer to another operation while previous information can be held. The combining of this mode, the author successfully used one key control loop measurement for test Dual Input Memory module which is used in a rearrange Energy Trigger system for LEP 8 Bunch operation

  2. Repeatability of Retinal Sensitivity Measurements Using a Medmont Dark-Adapted Chromatic Perimeter in Healthy and Age-Related Macular Degeneration Cases.

    Science.gov (United States)

    Tan, Rose S; Guymer, Robyn H; Luu, Chi D

    2018-05-01

    To determine the intrasession and intersession test-retest repeatability of retinal sensitivity measurements using a dark-adapted chromatic perimeter (DACP). For intrasession testing, retinal sensitivity within the central 24° for the 505-nm stimulus was measured after 20, 30, and 40 minutes of dark adaptation (DA) and for the 625-nm stimulus was measured after the first and second 505-nm tests. For intersession testing, retinal sensitivity for both stimuli was measured after 30 minutes of DA at baseline and 1 month. The point-wise sensitivity (PWS) difference and coefficient of repeatability (CoR) of each stimulus and group were determined. For intrasession testing, 10 age-related macular degeneration (AMD) and eight control subjects were recruited. The overall CoR for the 505-nm stimulus was 8.4 dB for control subjects and 9.1 dB for AMD cases, and for the 625-nm stimulus was 6.7 dB for control subjects and 9.5 dB for AMD cases. For intersession testing, seven AMD cases and 13 control subjects returned an overall CoR for the 505-nm stimulus of 8.2 dB for the control and 11.7 dB for the AMD group. For the 625-nm stimulus the CoR was 6.2 dB for the control group and 8.4 dB for the AMD group. Approximately 80% of all test points had a PWS difference of ±5 dB between the two intrasession or intersession measurements for both stimuli. The CoR for the DACP is larger than that reported for scotopic perimeters; however, the majority of test points had a PWS difference of ±5 dB between tests. The DACP offers an opportunity to measure static and dynamic rod function at multiple locations with an acceptable reproducibility level.

  3. The method of contact angle measurements and estimation of work of adhesion in bioleaching of metals

    Directory of Open Access Journals (Sweden)

    Matlakowska Renata

    1999-01-01

    Full Text Available In this paper, we present our method for the measurement of contact angles on the surface of minerals during the bioleaching process because the standard deviation obtained in our measurements achieved unexpectedly low error. Construction of a goniometer connected with a specially prepared computer program allowed us to repeat measurements several times over a short time course, yielding excellent results. After defining points on the outline of the image of a drop and its baseline as well of the first approximation of the outline of the drop, an iterative process is initiated that is aimed at fitting the model of the drop and baseline. In turn, after defining the medium for which measurements were made, the work of adhesion is determined according to Young-Dupré equation. Calculations were made with the use of two methods named the L-M and L-Q methods.

  4. Methods and systems for measuring anions

    KAUST Repository

    Masih, Dilshad; Mohammed, Omar F.; Aly, Shawkat M.; Alarousu, Erkki

    2016-01-01

    Embodiments of the present disclosure provide for methods for detecting the presence and/or concentration of anions in a solution, systems for detecting the presence and/or concentration of anions in a solution, anion sensor systems, and the like.

  5. A Simulation Method Measuring Psychomotor Nursing Skills.

    Science.gov (United States)

    McBride, Helena; And Others

    1981-01-01

    The development of a simulation technique to evaluate performance of psychomotor skills in an undergraduate nursing program is described. This method is used as one admission requirement to an alternate route nursing program. With modifications, any health profession could use this technique where psychomotor skills performance is important.…

  6. Methods and systems for measuring anions

    KAUST Repository

    Masih, Dilshad

    2016-08-18

    Embodiments of the present disclosure provide for methods for detecting the presence and/or concentration of anions in a solution, systems for detecting the presence and/or concentration of anions in a solution, anion sensor systems, and the like.

  7. Telerobotic system performance measurement - Motivation and methods

    Science.gov (United States)

    Kondraske, George V.; Khoury, George J.

    1992-01-01

    A systems performance-based strategy for modeling and conducting experiments relevant to the design and performance characterization of telerobotic systems is described. A developmental testbed consisting of a distributed telerobotics network and initial efforts to implement the strategy described is presented. Consideration is given to the general systems performance theory (GSPT) to tackle human performance problems as a basis for: measurement of overall telerobotic system (TRS) performance; task decomposition; development of a generic TRS model; and the characterization of performance of subsystems comprising the generic model. GSPT employs a resource construct to model performance and resource economic principles to govern the interface of systems to tasks. It provides a comprehensive modeling/measurement strategy applicable to complex systems including both human and artificial components. Application is presented within the framework of a distributed telerobotics network as a testbed. Insight into the design of test protocols which elicit application-independent data is described.

  8. Measurement methods on the complexity of network

    Institute of Scientific and Technical Information of China (English)

    LIN Lin; DING Gang; CHEN Guo-song

    2010-01-01

    Based on the size of network and the number of paths in the network,we proposed a model of topology complexity of a network to measure the topology complexity of the network.Based on the analyses of the effects of the number of the equipment,the types of equipment and the processing time of the node on the complexity of the network with the equipment-constrained,a complexity model of equipment-constrained network was constructed to measure the integrated complexity of the equipment-constrained network.The algorithms for the two models were also developed.An automatic generator of the random single label network was developed to test the models.The results show that the models can correctly evaluate the topology complexity and the integrated complexity of the networks.

  9. Liquid temperature measuring method and device therefor

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Fumi; Karasawa, Hirokazu

    1995-06-02

    In the present invention, temperature of liquid metal in coolants in an FBR type reactor can accurately be measured at rapid response time. Namely, ultrasonic waves are emitted from an ultrasonic wave sensor disposed in the air to a guide wave tube. Ultrasonic waves are reflected at reflection plates disposed at front and back or upper and lower portions of a small hole disposed to the wave guide tube. The reflected waves are received by the sensor described above. The difference of the reaching time of the reflected waves from the reflecting plates disposed at the front and the back or the upper and lower portions is measured. The speed of sounds in this case is determined based on the size of the small hole and the distance of the upper and the lower reflection plates. The speed of sounds is determined by the formula below: V(m/s) = 2500 - 0.52 T, where T: temperature. The temperature of the liquid can easily be calculated based on the formula. Accordingly, since the speed of the ultrasonic waves from their emission to the reception is msec order, and the processing of the signals are simple, the temperature can be measured at a response time of several msecs. In addition, since the ultrasonic wave sensor is disposed at the outside of the reactor, no special countermeasure for environmental circumstances is necessary, to improve maintenance ability. (I.S.).

  10. Dynamic Pain Phenotypes are Associated with Spinal Cord Stimulation-Induced Reduction in Pain: A Repeated Measures Observational Pilot Study.

    Science.gov (United States)

    Campbell, Claudia M; Buenaver, Luis F; Raja, Srinivasa N; Kiley, Kasey B; Swedberg, Lauren J; Wacnik, Paul W; Cohen, Steven P; Erdek, Michael A; Williams, Kayode A; Christo, Paul J

    2015-07-01

    Spinal cord stimulation (SCS) has become a widely used treatment option for a variety of pain conditions. Substantial variability exists in the degree of benefit obtained from SCS and patient selection is a topic of expanding interest and importance. However, few studies have examined the potential benefits of dynamic quantitative sensory testing (QST) to develop objective measures of SCS outcomes or as a predictive tool to help patient selection. Psychological characteristics have been shown to play an important role in shaping individual differences in the pain experience and may aid in predicting responses to SCS. Static laboratory pain-induction measures have also been examined in their capacity for predicting SCS outcomes. The current study evaluated clinical, psychological and laboratory pain measures at baseline, during trial SCS lead placement, as well as 1 month and 3 months following permanent SCS implantation in chronic pain patients who received SCS treatment. Several QST measures were conducted, with specific focus on examination of dynamic models (central sensitization and conditioned pain modulation [CPM]) and their association with pain outcomes 3 months post SCS implantation. Results suggest few changes in QST over time. However, central sensitization and CPM at baseline were significantly associated with clinical pain at 3 months following SCS implantation, controlling for psycho/behavioral factors and pain at baseline. Specifically, enhanced central sensitization and reduced CPM were associated with less self-reported pain 3 months following SCS implantation. These findings suggest a potentially important role for dynamic pain assessment in individuals undergoing SCS, and hint at potential mechanisms through which SCS may impart its benefit. Wiley Periodicals, Inc.

  11. Optimization on Measurement Method for Neutron Moisture Meter

    International Nuclear Information System (INIS)

    Gong Yalin; Wu Zhiqiang; Li Yanfeng; Wang Wei; Song Qingfeng; Liu Hui; Wei Xiaoyun; Zhao Zhonghua

    2010-01-01

    When the water in the measured material is nonuniformity, the measured results of the neutron moisture meter in the field may have errors, so the measured errors of the moisture meter associated with the water nonuniformity in material were simulated by Monte Carlo method. A new measurement method of moisture meter named 'transmission plus scatter' was put forward. The experiment results show that the new measurement method can reduce the error even if the water in the material is nonuniformity. (authors)

  12. Quantitative Method of Measuring Metastatic Activity

    Science.gov (United States)

    Morrison, Dennis R. (Inventor)

    1999-01-01

    The metastatic potential of tumors can be evaluated by the quantitative detection of urokinase and DNA. The cell sample selected for examination is analyzed for the presence of high levels of urokinase and abnormal DNA using analytical flow cytometry and digital image analysis. Other factors such as membrane associated uroldnase, increased DNA synthesis rates and certain receptors can be used in the method for detection of potentially invasive tumors.

  13. Modelling methods for milk intake measurements

    International Nuclear Information System (INIS)

    Coward, W.A.

    1999-01-01

    One component of the first Research Coordination Programme was a tutorial session on modelling in in-vivo tracer kinetic methods. This section describes the principles that are involved and how these can be translated into spreadsheets using Microsoft Excel and the SOLVER function to fit the model to the data. The purpose of this section is to describe the system developed within the RCM, and how it is used

  14. Repeated cycles of chemical and physical disinfection and their influence on Mycobacterium avium subsp. paratuberculosis viability measured by propidium monoazide F57 quantitative real time PCR.

    Science.gov (United States)

    Kralik, Petr; Babak, Vladimir; Dziedzinska, Radka

    2014-09-01

    Mycobacterium avium subsp. paratuberculosis (MAP) has a high degree of resistance to chemical and physical procedures frequently used for the elimination of other bacteria. Recently, a method for the determination of viability by exposure of MAP to propidium monoazide (PMA) and subsequent real time quantitative PCR (qPCR) was established and found to be comparable with culture. The aim of this study was to apply the PMA qPCR method to determine the impact of increasing concentration or time and repeated cycles of the application of selected disinfectants on MAP viability. Different MAP isolates responded to the same type of stress in different ways. The laboratory strain CAPM 6381 had the highest tolerance, while the 8819 low-passage field isolate was the most sensitive. Ultraviolet exposure caused only a partial reduction in MAP viability; all MAP isolates were relatively resistant to chlorine. Only the application of peracetic acid led to the total elimination of MAP. Repeated application of the treatments resulted in more significant decreases in MAP viability compared to single increases in the concentration or time of exposure to the disinfectant. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Evaluation of a Direct-Instruction Intervention to Improve Movement and Preliteracy Skills among Young Children: A Within-Subject Repeated-Measures Design

    Directory of Open Access Journals (Sweden)

    Chloe Bedard

    2018-01-01

    Full Text Available ObjectiveSchool readiness involves the development of foundational skills such as emergent literacy and fundamental movement skills as well as the capacity to attentively engage in instructional situations. Children do not develop these skills naturally; therefore, they need the opportunity to develop these skills in their early years prior to entering school. The objective of the current study was to evaluate the effectiveness and feasibility of a direct-instruction movement and preliteracy intervention in children aged 3–4 years.MethodsA within-subject repeated-measures design, embedded within a wait-list control study, was used to evaluate the intervention. The intervention was run across 10 weeks with 1 h weekly sessions. Each weekly session consisted of 30-min of movement skill instruction (e.g., through single-step acquisition strategies, 15-min of free play during which time children had access to a variety of equipment (e.g., balls, hula hoops, etc. or toys (e.g., puzzles, building blocks, and a 15-min interactive reading circle during which children read a storybook and were taught 1–2 preliteracy skills (e.g., alphabet knowledge, narrative knowledge, etc.. A convenience sample of 11 children (mean age = 45.6 months, SD = 7.3 was recruited. All children were assessed four times: baseline (Time 1, pre-intervention (Time 2, post-intervention (Time 3, and 5-week follow-up (Time 4. Gross motor skills and preliteracy skills were assessed at each time point.ResultsThere was a statistically significant effect of time on the change in gross motor skills (Wilks’ lambda = 0.09, p = .002, print-concept skills (Wilks’ lambda = 0.09, p = .001, and alphabet knowledge (Wilks’ lambda = 0.29, p = .046. Post hoc analyses reveal non-significant changes between time 1 and 2 for motor and print-concept skills and significant changes in all three outcomes between time 2 and time 3.ConclusionParticipation in a

  16. A probit- log- skew-normal mixture model for repeated measures data with excess zeros, with application to a cohort study of paediatric respiratory symptoms

    Directory of Open Access Journals (Sweden)

    Johnston Neil W

    2010-06-01

    Full Text Available Abstract Background A zero-inflated continuous outcome is characterized by occurrence of "excess" zeros that more than a single distribution can explain, with the positive observations forming a skewed distribution. Mixture models are employed for regression analysis of zero-inflated data. Moreover, for repeated measures zero-inflated data the clustering structure should also be modeled for an adequate analysis. Methods Diary of Asthma and Viral Infections Study (DAVIS was a one year (2004 cohort study conducted at McMaster University to monitor viral infection and respiratory symptoms in children aged 5-11 years with and without asthma. Respiratory symptoms were recorded daily using either an Internet or paper-based diary. Changes in symptoms were assessed by study staff and led to collection of nasal fluid specimens for virological testing. The study objectives included investigating the response of respiratory symptoms to respiratory viral infection in children with and without asthma over a one year period. Due to sparse data daily respiratory symptom scores were aggregated into weekly average scores. More than 70% of the weekly average scores were zero, with the positive scores forming a skewed distribution. We propose a random effects probit/log-skew-normal mixture model to analyze the DAVIS data. The model parameters were estimated using a maximum marginal likelihood approach. A simulation study was conducted to assess the performance of the proposed mixture model if the underlying distribution of the positive response is different from log-skew normal. Results Viral infection status was highly significant in both probit and log-skew normal model components respectively. The probability of being symptom free was much lower for the week a child was viral positive relative to the week she/he was viral negative. The severity of the symptoms was also greater for the week a child was viral positive. The probability of being symptom free was

  17. Repeated measures of body mass index and C-reactive protein in relation to all-cause mortality and cardiovascular disease

    DEFF Research Database (Denmark)

    O'Doherty, Mark G; Jørgensen, Torben; Borglykke, Anders

    2014-01-01

    Obesity has been linked with elevated levels of C-reactive protein (CRP), and both have been associated with increased risk of mortality and cardiovascular disease (CVD). Previous studies have used a single 'baseline' measurement and such analyses cannot account for possible changes in these which...... may lead to a biased estimation of risk. Using four cohorts from CHANCES which had repeated measures in participants 50 years and older, multivariate time-dependent Cox proportional hazards was used to estimate hazard ratios (HR) and 95 % confidence intervals (CI) to examine the relationship between......, they may participate in distinct/independent pathways. Accounting for independent changes in risk factors over time may be crucial for unveiling their effects on mortality and disease morbidity....

  18. Development of nondestructive hybrid measuring method for three-dimensional residual stress distribution of thick welded joint. Hybrid measuring method of inherent strain method and neutron diffraction method

    International Nuclear Information System (INIS)

    Nakacho, Keiji; Kasahara, Norifumi; Tamura, Ryota

    2012-01-01

    The measuring methods of the residual stress are classified into destructive one and nondestructive one. The inherent strain method (ISM) is destructive one. The neutron diffraction method (NDM) is nondestructive one. But the measurable depth is limited within about 20 mm and the method cannot measure the weld zone, without destruction of the object. So, in this study, the hybrid measuring method has been developed, by combining the ISM and the NDM. The theory of the hybrid method is the same as the ISM. In the analysis, the strains measured by the NDM without destruction are used. This hybrid measuring method is a true nondestructive measuring method for a thick welded joint. The applicability of the hybrid method has been verified by simulation, using a butt welded joint of thick pipes. In the simulation, the reliable order of the strains measured by the present NDM is very important, and was considered as 10 micro. The measurable regions by the present NDM were assumed. Under the above conditions, the data (the residual elastic strains assumed to be measured by the NDM) were made, and used in the ISM. As a result of such simulation, it has been cleared that the estimated residual stress has very high accuracy, if enough data are used. The required number of data is less than the ISM. (author)

  19. Spherical aberration compensation method for long focal-length measurement based on Talbot interferometry

    Science.gov (United States)

    Luo, Yupeng; Huang, Xiao; Bai, Jian; Du, Juan; Liu, Qun; Luo, Yujie; Luo, Jia

    2017-08-01

    Large-aperture and long focal-length lens is widely used in high energy laser system. The method based on Talbot interferometry is a reliable method to measure the focal length of such elements. By employing divergent beam and two gratings of different periods, this method could realize full-aperture measurement, higher accuracy and better repeatability. However, it does not take into account the spherical aberration of the measured lens resulting in the moiré fringes bending, which will introduce measurement error. Furthermore, in long-focal measurement with divergent beam, this error is an important factor affecting the measurement accuracy. In this paper, we propose a new spherical aberration compensation method, which could significantly reduce the measurement error. Characterized by central-symmetric scanning window, the proposed method is based on the relationship between spherical aberration and the lens aperture. Angle data of moiré fringes in each scanning window is retrieved by Fourier analysis and statistically fitted to estimate a globally optimum value for spherical-aberration-free focal length calculation. Simulation and experiment have been carried out. Compared to the previous work, the proposed method is able to reduce the relative measurement error by 50%. The effect of scanning window size and shift step length on the results is also discussed.

  20. Tidal breath eNO measurements in a cohort of unsedated hospitalized neonates-A method validation

    DEFF Research Database (Denmark)

    Schmidt, Birgitte J; Reim, Pauline S; Jensen, Andreas K

    2018-01-01

    to validate clinically feasible longitudinal online tidal eNO and V'NO in a real-life birth cohort of un-sedated, hospitalized preterm, and term neonates. METHOD: We included 149 newborns, GA 28-42 weeks. Each scheduled for six repeated, non-invasive, on-line eNO measurements with Ecomedics CLD 88sp and NO...

  1. Method of measuring the polarization of high momentum proton beams

    International Nuclear Information System (INIS)

    Underwood, D.G.

    1976-01-01

    A method of measuring the polarization of high momentum proton beams is proposed. This method utilizes the Primakoff effect and relates asymmetries at high energy to large asymmetries already measured at low energy. Such a new method is essential for the success of future experiments at energies where present methods are no longer feasible

  2. Measurement method of cardiac computed tomography (CT)

    International Nuclear Information System (INIS)

    Watanabe, Shigeru; Yamamoto, Hironori; Yumura, Yasuo; Yoshida, Hideo; Morooka, Nobuhiro

    1980-01-01

    The CT was carried out in 126 cases consisting of 31 normals, 17 cases of mitral stenosis (MS), 8 cases of mitral regurgitation (MR), 11 cases of aortic stenosis (AS), 9 cases of aortic regurgitation (AR), 20 cases of myocardial infarction (MI), 8 cases of atrial septal defect (ASD) and 22 hypertensives. The 20-second scans were performed every 1.5 cm from the 2nd intercostal space to the 5th or 6th intercostal space. The computed tomograms obtained were classified into 8 levels by cross-sectional anatomy; levels of (1) the aortic arch, (2) just beneath the aortic arch, (3) the pulmonary artery bifurcation, (4) the right atrial appendage or the upper right atrium, (5) the aortic root, (6) the upper left ventricle, (7) the mid left ventricle, and (8) the lower left ventricle. The diameter (anteroposterior and transverse) and cross-sectional area were measured about ascending aorta (Ao), descending aorta (AoD), superior vena cava (SVC), inferoir vena cava (IVC), pulmonary artery branch (PA), main pulmonary artery (mPA), left atrium (LA), right atrium (RA), and right ventricular outflow tract (RVOT) on each level where they were clearly distinguished. However, it was difficult to separate cardiac wall from cardiac cavity because there was little difference of X-ray attenuation coefficient between the myocardium and blood. Therefore, on mid ventricular level, diameter and area about total cardiac shadow were measured, and then cardiac ratios to the thorax were respectively calculated. The normal range of their values was shown in table, and abnormal characteristics in cardiac disease were exhibited in comparison with normal values. In MS, diameter and area in LA were significantly larger than normal. In MS and ASD, all the right cardiac system were larger than normal, especially, RA and SVC in MS, PA and RVOT in ASD. The diameter and area of the aortic root was larger in the order of AR, AS and HT than normal. (author)

  3. Automated genotyping of dinucleotide repeat markers

    Energy Technology Data Exchange (ETDEWEB)

    Perlin, M.W.; Hoffman, E.P. [Carnegie Mellon Univ., Pittsburgh, PA (United States)]|[Univ. of Pittsburgh, PA (United States)

    1994-09-01

    The dinucleotide repeats (i.e., microsatellites) such as CA-repeats are a highly polymorphic, highly abundant class of PCR-amplifiable markers that have greatly streamlined genetic mapping experimentation. It is expected that over 30,000 such markers (including tri- and tetranucleotide repeats) will be characterized for routine use in the next few years. Since only size determination, and not sequencing, is required to determine alleles, in principle, dinucleotide repeat genotyping is easily performed on electrophoretic gels, and can be automated using DNA sequencers. Unfortunately, PCR stuttering with these markers generates not one band for each allele, but a pattern of bands. Since closely spaced alleles must be disambiguated by human scoring, this poses a key obstacle to full automation. We have developed methods that overcome this obstacle. Our model is that the observed data is generated by arithmetic superposition (i.e., convolution) of multiple allele patterns. By quantitatively measuring the size of each component band, and exploiting the unique stutter pattern associated with each marker, closely spaced alleles can be deconvolved; this unambiguously reconstructs the {open_quotes}true{close_quotes} allele bands, with stutter artifact removed. We used this approach in a system for automated diagnosis of (X-linked) Duchenne muscular dystrophy; four multiplexed CA-repeats within the dystrophin gene were assayed on a DNA sequencer. Our method accurately detected small variations in gel migration that shifted the allele size estimate. In 167 nonmutated alleles, 89% (149/167) showed no size variation, 9% (15/167) showed 1 bp variation, and 2% (3/167) showed 2 bp variation. We are currently developing a library of dinucleotide repeat patterns; together with our deconvolution methods, this library will enable fully automated genotyping of dinucleotide repeats from sizing data.

  4. Quantitative method for analysis of six anticoagulant rodenticides in faeces, applied in a case with repeated samples from a dog.

    Science.gov (United States)

    Seljetun, Kristin Opdal; Eliassen, Elin; Karinen, Ritva; Moe, Lars; Vindenes, Vigdis

    2018-01-17

    Accidental poisoning with anticoagulant rodenticides is not uncommon in dogs, but few reports of the elimination kinetics and half-lives in this species have been published. Our objectives were to develop and validate a new method for the quantification of anticoagulant rodenticides in canine blood and faeces using reversed phase ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and apply the method on a case of anticoagulant rodenticide intoxication. Sample preparation was liquid-liquid extraction. Six anticoagulant rodenticides were separated using a UPLC ® BEH C 18 -column with a mobile phase consisting of 5 mM ammonium formate buffer pH 10.2 and methanol. MS/MS detection was performed with positive electrospray ionization and two multiple reaction monitoring transitions. The limits of quantification were set at the levels of the lowest calibrator (1.5-2.7 ng/mL or ng/g). The method was successfully applied to a case from a dog accidentally poisoned with anticoagulant rodenticide. Coumatetralyl and brodifacoum concentrations were determined from serial blood and faecal samples. A terminal half-life of at least 81 days for coumatetralyl in blood was estimated, which is longer than previous reported in other species. A slow elimination of brodifacoum from the faeces was found, with traces still detectable in the faeces at day 513. This study offers a new method of detection and quantification of six frequently used anticoagulant rodenticides in canine faeces. Such drugs might cause serious health effects and it is important to be able to detect these drugs, to initiate proper treatment. The very long elimination half-lives detected in our study is important to be aware of in assessment of anticoagulant rodenticide burden to the environment.

  5. Fast and accurate algorithm for repeated optical trapping simulations on arbitrarily shaped particles based on boundary element method

    International Nuclear Information System (INIS)

    Xu, Kai-Jiang; Pan, Xiao-Min; Li, Ren-Xian; Sheng, Xin-Qing

    2017-01-01

    In optical trapping applications, the optical force should be investigated within a wide range of parameter space in terms of beam configuration to reach the desirable performance. A simple but reliable way of conducting the related investigation is to evaluate optical forces corresponding to all possible beam configurations. Although the optical force exerted on arbitrarily shaped particles can be well predicted by boundary element method (BEM), such investigation is time costing because it involves many repetitions of expensive computation, where the forces are calculated from the equivalent surface currents. An algorithm is proposed to alleviate the difficulty by exploiting our previously developed skeletonization framework. The proposed algorithm succeeds in reducing the number of repetitions. Since the number of skeleton beams is always much less than that of beams in question, the computation can be very efficient. The proposed algorithm is accurate because the skeletonization is accuracy controllable. - Highlights: • A fast and accurate algorithm is proposed in terms of boundary element method to reduce the number of repetitions of computing the optical forces from the equivalent currents. • The algorithm is accuracy controllable because the accuracy of the associated rank-revealing process is well-controlled. • The accelerate rate can reach over one thousand because the number of skeleton beams can be very small. • The algorithm can be applied to other methods, e.g., FE-BI.

  6. Reducing repeat pregnancies in adolescence: applying realist principles as part of a mixed-methods systematic review to explore what works, for whom, how and under what circumstances.

    Science.gov (United States)

    Charles, Joanna M; Rycroft-Malone, Jo; Aslam, Rabeea'h; Hendry, Maggie; Pasterfield, Diana; Whitaker, Rhiannon

    2016-09-20

    Previous research has demonstrated emotional, psychological and educational harm to young mothers following unintended conceptions. The UK has one of the highest rates of pregnancies in adolescence in Western Europe with a high proportion of these being repeat pregnancies, making it a topic of interest for public health policy makers, and health and social care practitioners. As part of a wider mixed-methods systematic review, realist principles were applied to synthesise evidence about interventions aiming to reduce repeat pregnancies in adolescence. A multi-streamed, mixed-methods systematic review was conducted searching 11 major electronic databases and 9 additional databases from 1995 onwards, using key terms such as pregnancy, teen or adolescent. The principles of realist synthesis were applied to all included literature to uncover theories about what works, for whom, how and in what context. Initial theory areas were developed through evidence scoping, group discussion by the authors and stakeholder engagement to uncover context + mechanism = outcome (CMO) configurations and related narratives. The searches identified 8,664 documents initially, and 403 in repeat searches, filtering to 81 included studies, including qualitative studies, randomised controlled trials, quantitative studies and grey literature. Three CMO configurations were developed. The individual experiences of young mothers' triggered self-efficacy, notions of perceived risks, susceptibility and benefits of pregnancy, resulting in the adolescent taking control of their fertility and sexual encounters. The choice between motherhood and other goals triggered notions of motivations, resulting in the adolescent managing their expectations of motherhood and controlling their fertility and sexual encounters. Barriers and facilitators to accessing services triggered notions of connectedness and self-determination; resulting in interventions that are tailored so they are relevant to young

  7. Atmospheric Pressure and Onset of Episodes of Menière’s Disease - A Repeated Measures Study

    Science.gov (United States)

    Strobl, Ralf; Heinlin, Nina; Krause, Eike; Olzowy, Bernhard; Koppe, Christina; Grill, Eva

    2016-01-01

    Background External changes of air pressure are transmitted to the middle and inner ear and may be used therapeutically in Menière’s disease, one of the most common vertigo disorders. We analyzed the possible relationship of atmospheric pressure and other meteorological parameters with the onset of MD vertigo episodes in order to determine whether atmospheric pressure changes play a role in the occurrence of MD episodes. Methods Patients of a tertiary outpatient dizziness clinic diagnosed with MD were asked to keep a daily vertigo diary to document MD episodes (2004–2009). Local air pressure, absolute temperature and dew point temperature were acquired on an hourly basis. Change in meteorological parameters was conceptualized as the maximum difference in a 24 hour time frame preceding each day. Effects were estimated using additive mixed models with a random participant effect. We included lagged air parameters, age, sex, weekday and season in the model. Results A total of 56 persons (59% female) with mean age 54 years were included. Mean follow-up time was 267 days. Persons experienced on average 10.3 episodes during the observation period (median 8). Age and change in air pressure were significantly associated with vertigo onset risk (Odds Ratio = 0.979 and 1.010). We could not show an effect of sex, weekday, season, air temperature, and dew point temperature. Conclusions Change in air pressure was significantly associated with onset of MD episodes, suggesting a potential triggering mechanism in the inner ear. MD patients may possibly use air pressure changes as an early warning system for vertigo attacks in the future. PMID:27096752

  8. Statistical methods for quality assurance basics, measurement, control, capability, and improvement

    CERN Document Server

    Vardeman, Stephen B

    2016-01-01

    This undergraduate statistical quality assurance textbook clearly shows with real projects, cases and data sets how statistical quality control tools are used in practice. Among the topics covered is a practical evaluation of measurement effectiveness for both continuous and discrete data. Gauge Reproducibility and Repeatability methodology (including confidence intervals for Repeatability, Reproducibility and the Gauge Capability Ratio) is thoroughly developed. Process capability indices and corresponding confidence intervals are also explained. In addition to process monitoring techniques, experimental design and analysis for process improvement are carefully presented. Factorial and Fractional Factorial arrangements of treatments and Response Surface methods are covered. Integrated throughout the book are rich sets of examples and problems that help readers gain a better understanding of where and how to apply statistical quality control tools. These large and realistic problem sets in combination with the...

  9. 30 CFR 75.1719-3 - Methods of measurement; light measuring instruments.

    Science.gov (United States)

    2010-07-01

    ... being measured and a sufficient distance from the surface to allow the light sensing element in the... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Methods of measurement; light measuring... § 75.1719-3 Methods of measurement; light measuring instruments. (a) Compliance with § 75.1719-1(d...

  10. An in-situ measuring method for planar straightness error

    Science.gov (United States)

    Chen, Xi; Fu, Luhua; Yang, Tongyu; Sun, Changku; Wang, Zhong; Zhao, Yan; Liu, Changjie

    2018-01-01

    According to some current problems in the course of measuring the plane shape error of workpiece, an in-situ measuring method based on laser triangulation is presented in this paper. The method avoids the inefficiency of traditional methods like knife straightedge as well as the time and cost requirements of coordinate measuring machine(CMM). A laser-based measuring head is designed and installed on the spindle of a numerical control(NC) machine. The measuring head moves in the path planning to measure measuring points. The spatial coordinates of the measuring points are obtained by the combination of the laser triangulation displacement sensor and the coordinate system of the NC machine, which could make the indicators of measurement come true. The method to evaluate planar straightness error adopts particle swarm optimization(PSO). To verify the feasibility and accuracy of the measuring method, simulation experiments were implemented with a CMM. Comparing the measurement results of measuring head with the corresponding measured values obtained by composite measuring machine, it is verified that the method can realize high-precise and automatic measurement of the planar straightness error of the workpiece.

  11. Pharmacokinetics of taurolidine following repeated intravenous infusions measured by HPLC-ESI-MS/MS of the derivatives taurultame and taurinamide in glioblastoma patients.

    Science.gov (United States)

    Stendel, Ruediger; Scheurer, Louis; Schlatterer, Kathrin; Stalder, Urs; Pfirrmann, Rolf W; Fiss, Ingo; Möhler, Hanns; Bigler, Laurent

    2007-01-01

    Taurolidine is known to have antimicrobial activity. Furthermore, at lower concentrations, it has been found to exert a selective antineoplastic effect in vitro and in vivo. The aim of this study was to investigate the pharmacokinetics of taurolidine in vivo following repeated intravenous infusion in a schedule used for the treatment of glioblastoma. As a prerequisite, the pharmacokinetics of taurolidine in human blood plasma and whole blood in vitro was investigated. The pharmacokinetics of taurolidine and its derivatives taurultame and taurinamide were investigated in human blood plasma and in whole blood in vitro using blood from a healthy male volunteer. During repeated intravenous infusion therapy with taurolidine, plasma samples were taken every hour for a period of 13 hours per day in seven patients (three male, four female; mean age 48.4 +/- 12.8 years, range 27-66 years) with a glioblastoma. Following dansyl derivatisation, the concentrations of taurultame and taurinamide were determined using a new method based on high-performance liquid chromatography (HPLC) online coupled to electrospray ionisation tandem mass spectrometry (ESI-MS/MS) in the multiple reaction monitoring mode. Under the experimental conditions used, taurolidine could not be determined directly and was back-calculated from the taurultame and taurinamide values. The new HPLC-ESI-MS/MS method demonstrated high accuracy and reproducibility. In vitro plasma concentrations of taurultame and taurinamide remained constant over the incubation period. In whole blood in vitro, a time-dependent formation of taurinamide was observed. At the start of the incubation, the taurultame-taurinamide ratio (TTR) was 0.95 at an initial taurolidine concentration of 50 microg/mL, and 1.69 at 100 microg/mL. The concentration of taurultame decreased at the same rate as the taurinamide concentration increased, showing logarithmic kinetics. The calculated taurolidine concentration remained largely constant over the

  12. Two to five repeated measurements per patient reduced the required sample size considerably in a randomized clinical trial for patients with inflammatory rheumatic diseases

    Directory of Open Access Journals (Sweden)

    Smedslund Geir

    2013-02-01

    Full Text Available Abstract Background Patient reported outcomes are accepted as important outcome measures in rheumatology. The fluctuating symptoms in patients with rheumatic diseases have serious implications for sample size in clinical trials. We estimated the effects of measuring the outcome 1-5 times on the sample size required in a two-armed trial. Findings In a randomized controlled trial that evaluated the effects of a mindfulness-based group intervention for patients with inflammatory arthritis (n=71, the outcome variables Numerical Rating Scales (NRS (pain, fatigue, disease activity, self-care ability, and emotional wellbeing and General Health Questionnaire (GHQ-20 were measured five times before and after the intervention. For each variable we calculated the necessary sample sizes for obtaining 80% power (α=.05 for one up to five measurements. Two, three, and four measures reduced the required sample sizes by 15%, 21%, and 24%, respectively. With three (and five measures, the required sample size per group was reduced from 56 to 39 (32 for the GHQ-20, from 71 to 60 (55 for pain, 96 to 71 (73 for fatigue, 57 to 51 (48 for disease activity, 59 to 44 (45 for self-care, and 47 to 37 (33 for emotional wellbeing. Conclusions Measuring the outcomes five times rather than once reduced the necessary sample size by an average of 27%. When planning a study, researchers should carefully compare the advantages and disadvantages of increasing sample size versus employing three to five repeated measurements in order to obtain the required statistical power.

  13. Teaching renewable energy using online PBL in investigating its effect on behaviour towards energy conservation among Malaysian students: ANOVA repeated measures approach

    Science.gov (United States)

    Nordin, Norfarah; Samsudin, Mohd Ali; Hadi Harun, Abdul

    2017-01-01

    This research aimed to investigate whether online problem based learning (PBL) approach to teach renewable energy topic improves students’ behaviour towards energy conservation. A renewable energy online problem based learning (REePBaL) instruction package was developed based on the theory of constructivism and adaptation of the online learning model. This study employed a single group quasi-experimental design to ascertain the changed in students’ behaviour towards energy conservation after underwent the intervention. The study involved 48 secondary school students in a Malaysian public school. ANOVA Repeated Measure technique was employed in order to compare scores of students’ behaviour towards energy conservation before and after the intervention. Based on the finding, students’ behaviour towards energy conservation improved after the intervention.

  14. PHASE GRADIENT METHOD OF MAGNETIC FIELD MEASUREMENTS IN ELECTRIC VEHICLES

    Directory of Open Access Journals (Sweden)

    N. G. Ptitsyna

    2013-01-01

    Full Text Available Operation of electric and hybrid vehicles demands real time magnetic field control, for instance, for fire and electromagnetic safety. The article deals with a method of magnetic field measurements onboard electric cars taking into account peculiar features of these fields. The method is based on differential methods of measurements, and minimizes the quantity of magnetic sensors.

  15. A condensed water method for measuring the atmospheric radon

    CERN Document Server

    Wu Xin; Pan Xiao Qing; Yu Yi Ling

    1998-01-01

    The author summarizes the present situation of atmospheric Radon measurement, and introduces the working principle, working method and advantage and disadvantage of condensed water method in detail. The structure and function of the instrument used for this method, and the measuring result are discussed. The direction of further work is pointed out from now on

  16. The effect of technical replicate (repeats) on Nix Pro Color Sensor™ measurement precision for meat: A case-study on aged beef colour stability.

    Science.gov (United States)

    Holman, Benjamin W B; Collins, Damian; Kilgannon, Ashleigh K; Hopkins, David L

    2018-01-01

    The Nix Pro Colour Sensor™ (NIX) can be potentially used to measure meat colour, but procedural guidelines that assure measurement reproducibility and repeatability (precision) must first be established. Technical replicate number (r) will minimise response variation, measureable as standard error of predicted mean (SEM), and contribute to improved precision. Consequently, we aimed to explore the effects of r on NIX precision when measuring aged beef colour (colorimetrics; L*, a*, b*, hue and chroma values). Each colorimetric SEM declined with increasing r to indicate improved precision and followed a diminishing rate of improvement that allowed us to recommend r=7 for meat colour studies using the NIX. This definition was based on practical limitations and a* variability, as additional r would be required if other colorimetrics or advanced levels of precision are necessary. Beef ageing and display period, holding temperature, loin and sampled portion were also found to contribute to colorimetric variation, but were incorporated within our definition of r. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  17. Evidence of radiation-induced reduction of height and body weight from repeated measurements of adults exposed in childhood to the atomic bombs

    International Nuclear Information System (INIS)

    Otake, Masanori; Funamoto, Sachiyo; Fujikoshi, Yasunori; Schull, W.J.

    1994-01-01

    Reduction of growth from exposure to atomic bomb radiation has been examined using individuals under 10 years old at the time of the bombing (ATB) and a growth curve analysis based on measurements of height and weight made in the course of the 4th-7th cycles of the Adult Health Study examinations (1964-1972). As expected, the largest difference in growth to emerge is between males and females. However, a highly significant reduction of growth associated with dose (DS86) was observed among those survivors for whom four repeated measurements of height and weight were available. Longitudinal analysis of a more extended data set (n = 821), using expected values based on simple linear regression models fitted to the three available sets of measurements of height and weight on the 254 individuals with a missing measurement, also indicates a significant radiation-related growth reduction. The possible contribution of such factors as poor nutrition and disruption of normal family life in the years immediately after the war is difficult to evaluate, but the effects of socioeconomic factors on the analysis of these data are discussed. 33 refs., 5 figs., 3 tabs

  18. Calibration and uncertainty in electromagnetic fields measuring methods

    International Nuclear Information System (INIS)

    Anglesio, L.; Crotti, G.; Borsero, M.; Vizio, G.

    1999-01-01

    Calibration and reliability in electromagnetic field measuring methods are assured by calibration of measuring instruments. In this work are illustrated systems for generation of electromagnetic fields at low and high frequency, calibration standard and accuracy [it

  19. Method for obtaining more precise measures of excreted organic carbon

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    A new method for concentrating and measuring excreted organic carbon by lyophilization and scintillation counting is efficient, improves measurable radioactivity, and increases precision for estimates of organic carbon excreted by phytoplankton and macrophytes

  20. CAPABILITY ASSESSMENT OF MEASURING EQUIPMENT USING STATISTIC METHOD

    Directory of Open Access Journals (Sweden)

    Pavel POLÁK

    2014-10-01

    Full Text Available Capability assessment of the measurement device is one of the methods of process quality control. Only in case the measurement device is capable, the capability of the measurement and consequently production process can be assessed. This paper deals with assessment of the capability of the measuring device using indices Cg and Cgk.

  1. Comparison of a Variable-Number Tandem-Repeat (VNTR) Method for Typing Mycobacterium avium with Mycobacterial Interspersed Repetitive-Unit-VNTR and IS1245 Restriction Fragment Length Polymorphism Typing▿ †

    OpenAIRE

    Inagaki, Takayuki; Nishimori, Kei; Yagi, Tetsuya; Ichikawa, Kazuya; Moriyama, Makoto; Nakagawa, Taku; Shibayama, Takami; Uchiya, Kei-ichi; Nikai, Toshiaki; Ogawa, Kenji

    2009-01-01

    Mycobacterium avium complex (MAC) infections are increasing annually in various countries, including Japan, but the route of transmission and pathophysiology of the infection remain unclear. Currently, a variable-number tandem-repeat (VNTR) typing method using the Mycobacterium avium tandem repeat (MATR) loci (MATR-VNTR) is employed in Japan for epidemiological studies using clinical isolates of M. avium. In this study, the usefulness of this MATR-VNTR typing method was compared with that of ...

  2. Comparison of radon diffusion coefficients measured by transient-diffusion and steady-state laboratory methods

    International Nuclear Information System (INIS)

    Kalwarf, D.R.; Nielson, K.K.; Rich, D.C.; Rogers, V.C.

    1982-11-01

    A method was developed and used to determine radon diffusion coefficients in compacted soils by transient-diffusion measurements. A relative standard deviation of 12% was observed in repeated measurements with a dry soil by the transient-diffusion method, and a 40% uncertainty was determined for moistures exceeding 50% of saturation. Excellent agreement was also obtained between values of the diffusion coefficient for radon in air, as measured by the transient-diffusion method, and those in the published literature. Good agreement was also obtained with diffusion coefficients measured by a steady-state method on the same soils. The agreement was best at low moistures, averaging less than ten percent difference, but differences of up to a factor of two were observed at high moistures. The comparison of the transient-diffusion and steady-state methods at low moistures provides an excellent verification of the theoretical validity and technical accuracy of these approaches, which are based on completely independent experimental conditions, measurement methods and mathematical interpretations

  3. [Rapid, simple genotyping method by the variable numbers of tandem repeats (VNTR) for Mycobacterium tuberculosis isolates in Japan--analytical procedure of JATA (12)-VNTR].

    Science.gov (United States)

    Maeda, Shinji; Murase, Yoshiro; Mitarai, Satoshi; Sugawara, Isamu; Kato, Seiya

    2008-10-01

    The discriminatory power of each locus in variable numbers of tandem repeats (VNTR) analyses was evaluated for development of the genotyping method of Mycobacterium tuberculosis (TB) in Japan. By using 325 TB strains collected from whole Japan and 24 mass infection cases (74 isolates), IS6110 restriction fragment length polymorphism (RFLP), spoligotyping and VNTR (35 loci) were analyzed. We excluded 4 loci (VNTRs 2163a, 3232, 3820, and 4120) and selected in top 12 loci (VNTRs 0424, 0960, 1955, 2074, 2163b, 2372, 2996, 3155, 3192, 3336, 4052, and 4156). The cluster rate of IS6110 RFLP was higher than that of 12-locus [Japan Anti-Tuberculosis Association (JATA)] VNTR. And in comparison of the discriminatory power of 12-locus JATA VNTR and that of Supply (15)-VNTR, the JATA (12)-VNTR was superior, even though less loci analyses. Therefore, this JATA (12)-VNTR could be used for TB genotyping in areas where Beijing strains are prevalent.

  4. Development of Single Optical Sensor Method for the Measurement Droplet Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Ho; Ahn, Tae Hwan; Yun, Byong Jo [Pusan National University, Busan (Korea, Republic of); Bae, Byoung Uhn; Kim, Kyoung Doo [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In this study, we tried to develop single optical fiber probe(S-TOP) sensor method to measure droplet parameters such as diameter, droplet fraction, and droplet velocity and so on. To calibrate and confirm the optical fiber sensor for those parameters, we conducted visualization experiments by using a high speed camera with the optical sensor. To evaluate the performance of the S-TOP accurately, we repeated calibration experiments at a given droplet flow condition. Figure. 3 shows the result of the calibration. In this graph, the x axis is the droplet velocity measured by visualization and the y axis is grd, D which is obtained from S-TOP. In this study, we have developed the single tip optical probe sensor to measure the droplet parameters. From the calibration experiments with high speed camera, we get the calibration curve for the droplet velocity. Additionally, the chord length distribution of droplets is measured by the optical probe.

  5. Development of Single Optical Sensor Method for the Measurement Droplet Parameters

    International Nuclear Information System (INIS)

    Kim, Tae Ho; Ahn, Tae Hwan; Yun, Byong Jo; Bae, Byoung Uhn; Kim, Kyoung Doo

    2016-01-01

    In this study, we tried to develop single optical fiber probe(S-TOP) sensor method to measure droplet parameters such as diameter, droplet fraction, and droplet velocity and so on. To calibrate and confirm the optical fiber sensor for those parameters, we conducted visualization experiments by using a high speed camera with the optical sensor. To evaluate the performance of the S-TOP accurately, we repeated calibration experiments at a given droplet flow condition. Figure. 3 shows the result of the calibration. In this graph, the x axis is the droplet velocity measured by visualization and the y axis is grd, D which is obtained from S-TOP. In this study, we have developed the single tip optical probe sensor to measure the droplet parameters. From the calibration experiments with high speed camera, we get the calibration curve for the droplet velocity. Additionally, the chord length distribution of droplets is measured by the optical probe.

  6. Repetibilidade e número mínimo de medições para caracteres de cacho de bacabi (Oenocarpus mapora Repeatability and minimum number of measurements for characters of bacabi palm (Oenocarpus mapora racemes

    Directory of Open Access Journals (Sweden)

    Maria do Socorro Padilha de Oliveira

    2010-12-01

    potential for commercial and food uses, but has not been well studied. The objectives of this study were to estimate the repeatability coefficients, determine predictability and the number of measurements needed for raceme characters of this palm. 27 individuals of bacabi that belong to the Germplasm Bank of Oenocarpus/Jessenia at Embrapa Eastern Amazon, in Belém, PA, Brazil were evaluated. Three fully matured racemes from each plant were sampled to measure six characters: total weight of raceme (TWR and fruit weight per raceme (FWR, number of rachillae per raceme (NRR, rachis length per raceme (RLR, weight of 100 fruits (WHF and fruit yield per raceme (FER. The repeatability estimates were obtained by three statistical methods: analysis of variance; principal components; and structural analysis. For all characters, the estimates of repeatability coefficients presented values with very similar magnitudes in the three methods. The estimates of repeatability coefficients and determination coefficients were relatively high (r 0.60 and R2 81.7% for the characters FER and NRR, showing genotype regularity for these raceme measurements. For these characters, the minimum number of racemes necessary to estimate the true character value of the genotypes was thirteen (FER and five (NRR, with 95% reliability. The remaining characters showed repeatabilities and determination coefficients with medium to low values, indicating the need for better environmental control to make the measurements.

  7. Development of a spatial analysis method using ground-based repeat photography to detect changes in the alpine treeline ecotone, Glacier National Park, Montana, U.S.A.

    Science.gov (United States)

    Roush, W.; Munroe, Jeffrey S.; Fagre, D.B.

    2007-01-01

    Repeat photography is a powerful tool for detection of landscape change over decadal timescales. Here a novel method is presented that applies spatial analysis software to digital photo-pairs, allowing vegetation change to be categorized and quantified. This method is applied to 12 sites within the alpine treeline ecotone of Glacier National Park, Montana, and is used to examine vegetation changes over timescales ranging from 71 to 93 years. Tree cover at the treeline ecotone increased in 10 out of the 12 photo-pairs (mean increase of 60%). Establishment occurred at all sites, infilling occurred at 11 sites. To demonstrate the utility of this method, patterns of tree establishment at treeline are described and the possible causes of changes within the treeline ecotone are discussed. Local factors undoubtedly affect the magnitude and type of the observed changes, however the ubiquity of the increase in tree cover implies a common forcing mechanism. Mean minimum summer temperatures have increased by 1.5??C over the past century and, coupled with variations in the amount of early spring snow water equivalent, likely account for much of the increase in tree cover at the treeline ecotone. Lastly, shortcomings of this method are presented along with possible solutions and areas for future research. ?? 2007 Regents of the University of Colorado.

  8. All-photonic quantum repeaters

    Science.gov (United States)

    Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

    2015-01-01

    Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories. PMID:25873153

  9. Repeat, Low Altitude Measurements of Vegetation Status and Biomass Using Manned Aerial and UAS Imagery in a Piñon-Juniper Woodland

    Science.gov (United States)

    Krofcheck, D. J.; Lippitt, C.; Loerch, A.; Litvak, M. E.

    2015-12-01

    Measuring the above ground biomass of vegetation is a critical component of any ecological monitoring campaign. Traditionally, biomass of vegetation was measured with allometric-based approach. However, it is also time-consuming, labor-intensive, and extremely expensive to conduct over large scales and consequently is cost-prohibitive at the landscape scale. Furthermore, in semi-arid ecosystems characterized by vegetation with inconsistent growth morphologies (e.g., piñon-juniper woodlands), even ground-based conventional allometric approaches are often challenging to execute consistently across individuals and through time, increasing the difficulty of the required measurements and consequently the accuracy of the resulting products. To constrain the uncertainty associated with these campaigns, and to expand the extent of our measurement capability, we made repeat measurements of vegetation biomass in a semi-arid piñon-juniper woodland using structure-from-motion (SfM) techniques. We used high-spatial resolution overlapping aerial images and high-accuracy ground control points collected from both manned aircraft and multi-rotor UAS platforms, to generate digital surface model (DSM) for our experimental region. We extracted high-precision canopy volumes from the DSM and compared these to the vegetation allometric data, s to generate high precision canopy volume models. We used these models to predict the drivers of allometric equations for Pinus edulis and Juniperous monosperma (canopy height, diameter at breast height, and root collar diameter). Using this approach, we successfully accounted for the carbon stocks in standing live and standing dead vegetation across a 9 ha region, which contained 12.6 Mg / ha of standing dead biomass, with good agreement to our field plots. Here we present the initial results from an object oriented workflow which aims to automate the biomass estimation process of tree crown delineation and volume calculation, and partition

  10. Research On The Measure Method Of Oblique Pinhole Parameters

    Directory of Open Access Journals (Sweden)

    Ma Yu-Zhen

    2016-01-01

    Full Text Available There are many special advantages in measuring the diameter of blind and deep holes with a capacitive probe, there are still some challenges for the measurement of a oblique pinhole parameters because the measuring device is inconvenient to stretch into the oblique pinhole exactly. A five-dimensional measurement system was adopted in the paper which included a capacitive sensor probe and a three-coordinate measuring machine to accomplish the measurement for oblique pinholes. With the help of the three-dimensional coordinates measured from the pinhole axis, we put forward a comprehensive method of combining the projection method and the least squares method together for fitting spatial straight line to obtain the optimal equation of the spacial axis. Finally, a reliable and entire measurement system was set up.

  11. Assessment of Different Sampling Methods for Measuring and Representing Macular Cone Density Using Flood-Illuminated Adaptive Optics.

    Science.gov (United States)

    Feng, Shu; Gale, Michael J; Fay, Jonathan D; Faridi, Ambar; Titus, Hope E; Garg, Anupam K; Michaels, Keith V; Erker, Laura R; Peters, Dawn; Smith, Travis B; Pennesi, Mark E

    2015-09-01

    To describe a standardized flood-illuminated adaptive optics (AO) imaging protocol suitable for the clinical setting and to assess sampling methods for measuring cone density. Cone density was calculated following three measurement protocols: 50 × 50-μm sampling window values every 0.5° along the horizontal and vertical meridians (fixed-interval method), the mean density of expanding 0.5°-wide arcuate areas in the nasal, temporal, superior, and inferior quadrants (arcuate mean method), and the peak cone density of a 50 × 50-μm sampling window within expanding arcuate areas near the meridian (peak density method). Repeated imaging was performed in nine subjects to determine intersession repeatability of cone density. Cone density montages could be created for 67 of the 74 subjects. Image quality was determined to be adequate for automated cone counting for 35 (52%) of the 67 subjects. We found that cone density varied with different sampling methods and regions tested. In the nasal and temporal quadrants, peak density most closely resembled histological data, whereas the arcuate mean and fixed-interval methods tended to underestimate the density compared with histological data. However, in the inferior and superior quadrants, arcuate mean and fixed-interval methods most closely matched histological data, whereas the peak density method overestimated cone density compared with histological data. Intersession repeatability testing showed that repeatability was greatest when sampling by arcuate mean and lowest when sampling by fixed interval. We show that different methods of sampling can significantly affect cone density measurements. Therefore, care must be taken when interpreting cone density results, even in a normal population.

  12. Comparison of passive and active radon measurement methods for personal occupational dose assessment

    Directory of Open Access Journals (Sweden)

    Hasanzadeh Elham

    2016-01-01

    Full Text Available To compare the performance of the active short-term and passive long-term radon measurement methods, a study was carried out in several closed spaces, including a uranium mine in Iran. For the passive method, solid-state nuclear track detectors based on Lexan polycarbonate were utilized, for the active method, AlphaGUARD. The study focused on the correlation between the results obtained for estimating the average indoor radon concentrations and consequent personal occupational doses in various working places. The repeatability of each method was investigated, too. In addition, it was shown that the radon concentrations in different stations of the continually ventilated uranium mine were comparable to the ground floor laboratories or storage rooms (without continual ventilation and lower than underground laboratories.

  13. Quantitative Methods for Measuring Repair Rates and Innate-Immune Cell Responses in Wounded Mouse Skin.

    Science.gov (United States)

    Li, Zhi; Gothard, Elizabeth; Coles, Mark C; Ambler, Carrie A

    2018-01-01

    In skin wounds, innate-immune cells clear up tissue debris and microbial contamination, and also secrete cytokines and other growth factors that impact repair process such as re-epithelialization and wound closure. After injury, there is a rapid influx and efflux of immune cells at wound sites, yet the function of each innate cell population in skin repair is still under investigation. Flow cytometry is a valuable research tool for detecting and quantifying immune cells; however, in mouse back skin, the difficulty in extracting immune cells from small area of skin due to tissue complexity has made cytometric analysis an underutilized tool. In this paper, we provide detailed methods on the digestion of lesion-specific skin without disrupting antigen expression followed by multiplex cell staining that allows for identification of seven innate-immune populations, including rare subsets such as group-3 innate lymphoid cells (ILC3s), by flow-cytometry analysis. Furthermore, when studying the functions of immune cells to tissue repair an important metric to monitor is size of the wound opening. Normal wounds close steadily albeit at non-linear rates, while slow or stalled wound closure can indicate an underlying problem with the repair process. Calliper measurements are difficult and time-consuming to obtain and can require repeated sedation of experimental animals. We provide advanced methods for measuring of wound openness; digital 3D image capture and semi-automated image processing that allows for unbiased, reliable measurements that can be taken repeatedly over time.

  14. Variability of bronchial measurements obtained by sequential CT using two computer-based methods

    International Nuclear Information System (INIS)

    Brillet, Pierre-Yves; Fetita, Catalin I.; Mitrea, Mihai; Preteux, Francoise; Capderou, Andre; Dreuil, Serge; Simon, Jean-Marc; Grenier, Philippe A.

    2009-01-01

    This study aimed to evaluate the variability of lumen (LA) and wall area (WA) measurements obtained on two successive MDCT acquisitions using energy-driven contour estimation (EDCE) and full width at half maximum (FWHM) approaches. Both methods were applied to a database of segmental and subsegmental bronchi with LA > 4 mm 2 containing 42 bronchial segments of 10 successive slices that best matched on each acquisition. For both methods, the 95% confidence interval between repeated MDCT was between -1.59 and 1.5 mm 2 for LA, and -3.31 and 2.96 mm 2 for WA. The values of the coefficient of measurement variation (CV 10 , i.e., percentage ratio of the standard deviation obtained from the 10 successive slices to their mean value) were strongly correlated between repeated MDCT data acquisitions (r > 0.72; p 2 , whereas WA values were lower for bronchi with WA 2 ; no systematic EDCE underestimation or overestimation was observed for thicker-walled bronchi. In conclusion, variability between CT examinations and assessment techniques may impair measurements. Therefore, new parameters such as CV 10 need to be investigated to study bronchial remodeling. Finally, EDCE and FWHM are not interchangeable in longitudinal studies. (orig.)

  15. Simple measurement of 14C in the environment using gel suspension method

    International Nuclear Information System (INIS)

    Wakabayashi, Genichiro; Oura, Hirotaka; Nagao, Kenjiro; Okai, Tomio; Matoba, Masaru; Kakiuchi, Hideki; Momoshima, Noriyuki; Kawamura, Hidehisa

    1999-01-01

    A gel suspension method using N-lauroyl-L-glutamic-α, γ-dibutylamide as gelling agent and calcium carbonate as sample was studied and it was proved a more simple measurement method of 14 C in environment than the ordinary method. 100, 20 and 7 ml of sample could introduce 3.6, 0.72 and 0.252 g of carbon, respectively. When 100 ml and 20 ml of vial introduced the maximum carbon, the lower limit of detection was about 0.3 dpm/g-C and 0.5 dpm/g-C, respectively. These values showed that this method was able to determine 14 C in the environment. The value of sample has been constant for two years or more. This fact indicated the sample prepared by this method was good for repeat measurement and long-term storage. Many samples prepared by the same calcium carbonate showed almost same values. The concentrations of 14 C in the growth rings of a tree and in rice in the environment were determined and the results agreed with the values in the references. From these above results, this method is more simple measurement method of 14 C in the environment than the ordinary method and can apply to determine 14 C in and around the nuclear installation. (S.Y.)

  16. How to measure comorbidity. a critical review of available methods.

    NARCIS (Netherlands)

    de Groot, V.; Beckerman, H.; Lankhorst, G.J.; Bouter, L.M.

    2003-01-01

    The object of this article was to systematically review available methods to measure comorbidity and to assess their validity and reliability. A search was made in Medline and Embase, with the keywords comorbidity and multi-morbidity, to identify articles in which a method to measure comorbidity was

  17. How to measure comorbidity. A critical review of available methods

    NARCIS (Netherlands)

    de Groot, V; Beckerman, H; Lankhorst, G J; Bouter, L M

    2003-01-01

    The object of this article was to systematically review available methods to measure comorbidity and to assess their validity and reliability. A search was made in Medline and Embase, with the keywords comorbidity and multi-morbidity, to identify articles in which a method to measure comorbidity was

  18. Accurate method of the magnetic field measurement of quadrupole magnets

    International Nuclear Information System (INIS)

    Kumada, M.; Sakai, I.; Someya, H.; Sasaki, H.

    1983-01-01

    We present an accurate method of the magnetic field measurement of the quadrupole magnet. The method of obtaining the information of the field gradient and the effective focussing length is given. A new scheme to obtain the information of the skew field components is also proposed. The relative accuracy of the measurement was 1 x 10 -4 or less. (author)

  19. Direct methods for radionuclides measurement in water environment

    International Nuclear Information System (INIS)

    Chernyaev, A.; Gaponov, I.; Kazennov, A.

    2004-01-01

    The paper is devoted to the direct method of anthropogenic radionuclide measurement in the water environment. Opportunities of application of submersible gamma-spectrometers for in situ underwater measurements of gamma-radiating nuclides and also the direct method for 90 Sr detection are considered

  20. Methods for production of UNK SC-dipoles magnetic measurements

    International Nuclear Information System (INIS)

    Smirnov, N.L.

    1991-01-01

    Many SC-dipoles for UNK will require from the chosen magnetic measurement methods high accuracy and efficiency. The brief of using methods, their possibilities and analysis of their errors are given. The measurements results for a full-scale model of SC-dipole SPDM1 are presented. 5 refs.; 4 figs.; 4 tabs

  1. The Sine Method: An Alternative Height Measurement Technique

    Science.gov (United States)

    Don C. Bragg; Lee E. Frelich; Robert T. Leverett; Will Blozan; Dale J. Luthringer

    2011-01-01

    Height is one of the most important dimensions of trees, but few observers are fully aware of the consequences of the misapplication of conventional height measurement techniques. A new approach, the sine method, can improve height measurement by being less sensitive to the requirements of conventional techniques (similar triangles and the tangent method). We studied...

  2. Instructions for applying inverse method for reactivity measurement

    International Nuclear Information System (INIS)

    Milosevic, M.

    1988-11-01

    This report is a brief description of the completed method for reactivity measurement. It contains description of the experimental procedure needed instrumentation and computer code IM for determining reactivity. The objective of this instructions manual is to enable experiments and reactivity measurement on any critical system according to the methods adopted at the RB reactor

  3. Testing and Validation of the Dynamic Interia Measurement Method

    Science.gov (United States)

    Chin, Alexander; Herrera, Claudia; Spivey, Natalie; Fladung, William; Cloutier, David

    2015-01-01

    This presentation describes the DIM method and how it measures the inertia properties of an object by analyzing the frequency response functions measured during a ground vibration test (GVT). The DIM method has been in development at the University of Cincinnati and has shown success on a variety of small scale test articles. The NASA AFRC version was modified for larger applications.

  4. Baseline repeated measures from controlled human exposure studies: associations between ambient air pollution exposure and the systemic inflammatory biomarkers IL-6 and fibrinogen.

    Science.gov (United States)

    Thompson, Aaron M S; Zanobetti, Antonella; Silverman, Frances; Schwartz, Joel; Coull, Brent; Urch, Bruce; Speck, Mary; Brook, Jeffrey R; Manno, Michael; Gold, Diane R

    2010-01-01

    Systemic inflammation may be one of the mechanisms mediating the association between ambient air pollution and cardiovascular morbidity and mortality. Interleukin-6 (IL-6) and fibrinogen are biomarkers of systemic inflammation that are independent risk factors for cardio-vascular disease. We investigated the association between ambient air pollution and systemic inflammation using baseline measurements of IL-6 and fibrinogen from controlled human exposure studies. In this retrospective analysis we used repeated-measures data in 45 nonsmoking subjects. Hourly and daily moving averages were calculated for ozone, nitrogen dioxide, sulfur dioxide, and particulate matter pollutants on systemic IL-6 and fibrinogen. Effect modification by season was considered. We observed a positive association between IL-6 and O3 [0.31 SD per O3 interquartile range (IQR); 95% confidence interval (CI), 0.080.54] and between IL-6 and SO2 (0.25 SD per SO2 IQR; 95% CI, 0.060.43). We observed the strongest effects using 4-day moving averages. Responses to pollutants varied by season and tended to be higher in the summer, particularly for O3 and PM2.5. Fibrinogen was not associated with pollution. This study demonstrates a significant association between ambient pollutant levels and baseline levels of systemic IL-6. These findings have potential implications for controlled human exposure studies. Future research should consider whether ambient pollution exposure before chamber exposure modifies IL-6 response.

  5. Measuring electric conductivity in liquid metals by eddy current method

    International Nuclear Information System (INIS)

    Zhuravlev, S.P.; Ostrovskij, O.I.; Grigoryan, V.A.

    1982-01-01

    Technique permitting to apply the method of vertiginous currents for investigation of electric conductivity of metal melts in the high temperature range is presented. Interferences affecting accuracy of measurements are specified and ways of their removing are pointed out. Scheme of measuring and design of the facility are described. Results of measuring electric resistance of liquid Fe, Co, Ni obtained for the first time by this method are presented. The data obtained agree with the results of measurements conducted by the method of the rotating magnetic field. Difference in absolute values of electric resistance in parallel experiments for each metal does not exceed 4%

  6. Helium Mass Spectrometer Leak Detection: A Method to Quantify Total Measurement Uncertainty

    Science.gov (United States)

    Mather, Janice L.; Taylor, Shawn C.

    2015-01-01

    In applications where leak rates of components or systems are evaluated against a leak rate requirement, the uncertainty of the measured leak rate must be included in the reported result. However, in the helium mass spectrometer leak detection method, the sensitivity, or resolution, of the instrument is often the only component of the total measurement uncertainty noted when reporting results. To address this shortfall, a measurement uncertainty analysis method was developed that includes the leak detector unit's resolution, repeatability, hysteresis, and drift, along with the uncertainty associated with the calibration standard. In a step-wise process, the method identifies the bias and precision components of the calibration standard, the measurement correction factor (K-factor), and the leak detector unit. Together these individual contributions to error are combined and the total measurement uncertainty is determined using the root-sum-square method. It was found that the precision component contributes more to the total uncertainty than the bias component, but the bias component is not insignificant. For helium mass spectrometer leak rate tests where unit sensitivity alone is not enough, a thorough evaluation of the measurement uncertainty such as the one presented herein should be performed and reported along with the leak rate value.

  7. Film repeats in radiology department

    International Nuclear Information System (INIS)

    Suwan, A. Z.; Al-Shakharah, A. I

    1997-01-01

    During a one year period, 4910 radiographs of 55780 films were repeated. The objective of our study was to analyse and to classify the causes in order to minimize the repeats, cut the expenses and to provide optimal radiographs for accurate diagnosis. Analysis of the different factors revealed that, 43.6% of film repeats in our service were due to faults in exposure factors, centering comprises 15.9% of the repeats, while too much collimation was responsible for 7.6% of these repeats. All of which can be decreased by awareness and programmed training of technicians. Film blurring caused by patient motion was also responsible for 4.9% for radiographs reexamination, which can be minimized by detailed explanation to the patient and providing the necessary privacy. Fogging of X-Ray films by improper storage or inadequate handling or processing faults were responsible for 14.5% in repeats in our study. Methods and criteria for proper storage and handling of films were discussed. Recommendation for using modern day-light and laser processor has been high lighted. Artefacts are noticeably high in our cases, due to spinal dresses and frequent usage of precious metals for c osmotic purposes in this part of the world. The repeated films comprise 8.8% of all films We conclude that, the main factor responsible for repeats of up to 81.6% of cases was the technologists, thus emphasizing the importance of adequate training of the technologists. (authors). 15 refs., 9 figs., 1 table

  8. A method of reconstructing the spatial measurement network by mobile measurement transmitter for shipbuilding

    International Nuclear Information System (INIS)

    Guo, Siyang; Lin, Jiarui; Yang, Linghui; Ren, Yongjie; Guo, Yin

    2017-01-01

    The workshop Measurement Position System (wMPS) is a distributed measurement system which is suitable for the large-scale metrology. However, there are some inevitable measurement problems in the shipbuilding industry, such as the restriction by obstacles and limited measurement range. To deal with these factors, this paper presents a method of reconstructing the spatial measurement network by mobile transmitter. A high-precision coordinate control network with more than six target points is established. The mobile measuring transmitter can be added into the measurement network using this coordinate control network with the spatial resection method. This method reconstructs the measurement network and broadens the measurement scope efficiently. To verify this method, two comparison experiments are designed with the laser tracker as the reference. The results demonstrate that the accuracy of point-to-point length is better than 0.4mm and the accuracy of coordinate measurement is better than 0.6mm. (paper)

  9. Carbon dioxide titration method for soil respiration measurements

    OpenAIRE

    Martín Rubio, Luis

    2017-01-01

    This thesis was commissioned by Tampere University of Applied Sciences, which was interested in studying and developing a titration measurement method for soil respiration and biodegradability. Some experiments were carried out measuring soil respiration for testing the method and others adding some biodegradable material like polylactic acid compressed material and 100% biodegradable plastic bags to test its biodegradability and the possibility to measure it via titration. The thesi...

  10. Gravimetric method for in vitro calibration of skin hydration measurements.

    Science.gov (United States)

    Martinsen, Ørjan G; Grimnes, Sverre; Nilsen, Jon K; Tronstad, Christian; Jang, Wooyoung; Kim, Hongsig; Shin, Kunsoo; Naderi, Majid; Thielmann, Frank

    2008-02-01

    A novel method for in vitro calibration of skin hydration measurements is presented. The method combines gravimetric and electrical measurements and reveals an exponential dependency of measured electrical susceptance to absolute water content in the epidermal stratum corneum. The results also show that absorption of water into the stratum corneum exhibits three different phases with significant differences in absorption time constant. These phases probably correspond to bound, loosely bound, and bulk water.

  11. Advanced Measuring (Instrumentation Methods for Nuclear Installations: A Review

    Directory of Open Access Journals (Sweden)

    Wang Qiu-kuan

    2012-01-01

    Full Text Available The nuclear technology has been widely used in the world. The research of measurement in nuclear installations involves many aspects, such as nuclear reactors, nuclear fuel cycle, safety and security, nuclear accident, after action, analysis, and environmental applications. In last decades, many advanced measuring devices and techniques have been widely applied in nuclear installations. This paper mainly introduces the development of the measuring (instrumentation methods for nuclear installations and the applications of these instruments and methods.

  12. Radon/radon-daughter measurement methods and instrumentation

    International Nuclear Information System (INIS)

    Rock, R.L.

    1977-01-01

    Radon-daughter measurement equipment and techniques have been continuously improved over the last 25 years. Improvements have been in the areas of accuracy, time and convenience. We now have miniaturized scalers and detectors available for measuring the alpha particle count rates from aerosol samples collected on filter papers. We also have small lightweight efficient pumps for conveniently collecting samples and we have various counting methods which allow us to choose between making very precise measurements or nominal measurements. Radon-daughter measurement methods used in uranium mines and mills are discussed including a personal radon-daughter-exposure integrating device which can be worn by miners

  13. Measurement of complex permittivity of composite materials using waveguide method

    NARCIS (Netherlands)

    Tereshchenko, O.V.; Buesink, Frederik Johannes Karel; Leferink, Frank Bernardus Johannes

    2011-01-01

    Complex dielectric permittivity of 4 different composite materials has been measured using the transmissionline method. A waveguide fixture in L, S, C and X band was used for the measurements. Measurement accuracy is influenced by air gaps between test fixtures and the materials tested. One of the

  14. Measurement of heat transfer coefficient using termoanemometry methods

    Science.gov (United States)

    Dančová, P.; Sitek, P.; Vít, T.

    2014-03-01

    This work deals with a measurement of heat transfer from a heated flat plate on which a synthetic jet impacts perpendicularly. Measurement of a heat transfer coefficient (HTC) is carried out using the hot wire anemometry method with glue film probe Dantec 55M47. The paper brings also results of velocity profiles measurements and turbulence intensity calculations.

  15. Measurement of heat transfer coefficient using termoanemometry methods

    Directory of Open Access Journals (Sweden)

    Dančová P.

    2014-03-01

    Full Text Available This work deals with a measurement of heat transfer from a heated flat plate on which a synthetic jet impacts perpendicularly. Measurement of a heat transfer coefficient (HTC is carried out using the hot wire anemometry method with glue film probe Dantec 55M47. The paper brings also results of velocity profiles measurements and turbulence intensity calculations.

  16. Measurement Methods to Determine Air Leakage Between Adjacent Zones

    Energy Technology Data Exchange (ETDEWEB)

    Hult, Erin L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dickerhoff, Darryl J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Phillip N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-09-01

    Air leakage between adjacent zones of a building can lead to indoor air quality and energy efficiency concerns, however there is no existing standard for measuring inter-zonal leakage. In this study, synthesized data and field measurements are analyzed in order to explore the uncertainty associated with different methods for collecting and analyzing fan pressurization measurements to calculate interzone leakage.

  17. Principle of coincidence method and application in activity measurement

    International Nuclear Information System (INIS)

    Li Mou; Dai Yihua; Ni Jianzhong

    2008-01-01

    The basic principle of coincidence method was discussed. The basic principle was generalized by analysing the actual example, and the condition in theory of coincidence method was brought forward. The cause of variation of efficiency curve and the effect of dead-time in activity measurement were explained using the above principle and condition. This principle of coincidence method provides the foundation in theory for activity measurement. (authors)

  18. Comparison of microstickies measurement methods. Part II, Results and discussion

    Science.gov (United States)

    Mahendra R. Doshi; Angeles Blanco; Carlos Negro; Concepcion Monte; Gilles M. Dorris; Carlos C. Castro; Axel Hamann; R. Daniel Haynes; Carl Houtman; Karen Scallon; Hans-Joachim Putz; Hans Johansson; R. A. Venditti; K. Copeland; H.-M. Chang

    2003-01-01

    In part I of the article we discussed sample preparation procedure and described various methods used for the measurement of microstickies. Some of the important features of different methods are highlighted in Table 1. Temperatures used in the measurement methods vary from room temperature in some cases, 45 °C to 65 °C in other cases. Sample size ranges from as low as...

  19. Wind turbine performance: Methods and criteria for reliability of measured power curves

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, D.A. [Advanced Wind Turbines Inc., Seattle, WA (United States)

    1996-12-31

    In order to evaluate the performance of prototype turbines, and to quantify incremental changes in performance through field testing, Advanced Wind Turbines (AWT) has been developing methods and requirements for power curve measurement. In this paper, field test data is used to illustrate several issues and trends which have resulted from this work. Averaging and binning processes, data hours per wind-speed bin, wind turbulence levels, and anemometry methods are all shown to have significant impacts on the resulting power curves. Criteria are given by which the AWT power curves show a high degree of repeatability, and these criteria are compared and contrasted with current published standards for power curve measurement. 6 refs., 5 figs., 5 tabs.

  20. Measurement of subcriticality by a pulsing α-method

    International Nuclear Information System (INIS)

    Jitarev, V.E.; Kachanov, V.M.; Kuzmin, A.N.

    1999-01-01

    The report presents results of a pulsing α-method [1] for determination of the WWER system subcriticality. The pulsing α-method permits to conduct measurements of system subcriticality in conditions of subcritical state and large neutron background. Therefore this method can be used for the control of a subcriticality of storehouses of a burn up nuclear fuel and stopped reactor. (Authors)

  1. Simple measuring rod method for the coaxiality of serial holes

    Science.gov (United States)

    Wang, Lei; Yang, Tongyu; Wang, Zhong; Ji, Yuchen; Liu, Changjie; Fu, Luhua

    2017-11-01

    Aiming at the rapid coaxiality measurement of serial hole part with a small diameter, a coaxiality measuring rod for each layer hole with a single LDS (laser displacement sensor) is proposed. This method does not require the rotation angle information of the rod, and the coaxiality of serial holes can be calculated from the measured values of LDSs after randomly rotating the measuring rod several times. With the mathematical model of the coaxiality measuring rod, each factor affecting the accuracy of coaxiality measurement is analyzed by simulation, and the installation accuracy requirements of the measuring rod and LDSs are presented. In the tolerance of a certain installation error of the measuring rod, the relative center of the hole is calculated by setting the over-determined nonlinear equations of the fitting circles of the multi-layer holes. In experiment, coaxiality measurement accuracy is realized by a 16 μm precision LDS, and the validity of the measurement method is verified. The manufacture and measurement requirements of the coaxiality measuring rod are low, by changing the position of LDSs in the measuring rod, the serial holes with different sizes and numbers can be measured. The rapid coaxiality measurement of parts can be easily implemented in industrial sites.

  2. Statistical learning modeling method for space debris photometric measurement

    Science.gov (United States)

    Sun, Wenjing; Sun, Jinqiu; Zhang, Yanning; Li, Haisen

    2016-03-01

    Photometric measurement is an important way to identify the space debris, but the present methods of photometric measurement have many constraints on star image and need complex image processing. Aiming at the problems, a statistical learning modeling method for space debris photometric measurement is proposed based on the global consistency of the star image, and the statistical information of star images is used to eliminate the measurement noises. First, the known stars on the star image are divided into training stars and testing stars. Then, the training stars are selected as the least squares fitting parameters to construct the photometric measurement model, and the testing stars are used to calculate the measurement accuracy of the photometric measurement model. Experimental results show that, the accuracy of the proposed photometric measurement model is about 0.1 magnitudes.

  3. Usefulness of repeated N-terminal pro-B-type natriuretic peptide measurements as incremental predictor for long-term cardiovascular outcome after vascular surgery.

    Science.gov (United States)

    Goei, Dustin; van Kuijk, Jan-Peter; Flu, Willem-Jan; Hoeks, Sanne E; Chonchol, Michel; Verhagen, Hence J M; Bax, Jeroen J; Poldermans, Don

    2011-02-15

    Plasma N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) levels improve preoperative cardiac risk stratification in vascular surgery patients. However, single preoperative measurements of NT-pro-BNP cannot take into account the hemodynamic stress caused by anesthesia and surgery. Therefore, the aim of the present study was to assess the incremental predictive value of changes in NT-pro-BNP during the perioperative period for long-term cardiac mortality. Detailed cardiac histories, rest left ventricular echocardiography, and NT-pro-BNP levels were obtained in 144 patients before vascular surgery and before discharge. The study end point was the occurrence of cardiovascular death during a median follow-up period of 13 months (interquartile range 5 to 20). Preoperatively, the median NT-pro-BNP level in the study population was 314 pg/ml (interquartile range 136 to 1,351), which increased to a median level of 1,505 pg/ml (interquartile range 404 to 6,453) before discharge. During the follow-up period, 29 patients (20%) died, 27 (93%) from cardiovascular causes. The median difference in NT-pro-BNP in the survivors was 665 pg/ml, compared to 5,336 pg/ml in the patients who died (p = 0.01). Multivariate Cox regression analyses, adjusted for cardiac history and cardiovascular risk factors (age, angina pectoris, myocardial infarction, stroke, diabetes mellitus, renal dysfunction, body mass index, type of surgery and the left ventricular ejection fraction), demonstrated that the difference in NT-pro-BNP level between pre- and postoperative measurement was the strongest independent predictor of cardiac outcome (hazard ratio 3.06, 95% confidence interval 1.36 to 6.91). In conclusion, the change in NT-pro-BNP, indicated by repeated measurements before surgery and before discharge is the strongest predictor of cardiac outcomes in patients who undergo vascular surgery. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. A new rapid method to measure human platelet cholesterol: a pilot study.

    Science.gov (United States)

    Jagroop, I Anita; Persaud, Jahm Want; Mikhailidis, Dimitri P

    2011-01-01

    Platelet cholesterol (PC) could be used to assess "tissue" cholesterol of patients with vascular disease. However, the methods available so far to measure PC involve a complex extraction process. We developed a rapid method to measure PC and assessed its correlation with serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), LDL-C/HDL-C ratio, triglycerides (TG), and non-HDL-C. We assessed repeatability (20 times, 3 participants) and reproducibility (8 times, 2 participants). A group of 47 healthy participants was studied. Blood was collected to analyze serum TC, LDL-C, HDL-C, and TG. Citrated blood was used to prepare a platelet pellet. A "clear soup" was produced (by disrupting this pellet using freeze-thaw and sonication cycles) and used to measure PC. Repeatability of PC showed a coefficient of variation (CV) of 4.8%. The reproducibility of PC over a period of 2 months was CV 7.5% and 8.1% (8 measurements for 2 participants). The PC of participants with serum LDL-C >2.6 mmol/L (treatment goal recommended by the National Cholesterol Education Program Adult Treatment Panel III) was 377 ± 120 μmol/10(12) platelets (n = 25). There was a significant correlation (Spearman, correlation coefficient) of PC (n = 25) with serum LDL-C (r(s) = 0.45, P = .02), LDL-C/HDL-C (r(s) = 0.45, P = .02), TG (r(s) = 0.43, P = .03), and non-HDL-C (r(s) = 0.53, P = .007). This technique of measuring PC has the advantage of being reproducible, fast, and simpler than previous methods. Thus, it may be useful for multiple sampling when investigating changes in PC in hypercholesterolemic patients. More extensive evaluation is necessary.

  5. An interlaboratory comparison of methods for measuring rock matrix porosity

    International Nuclear Information System (INIS)

    Rasilainen, K.; Hellmuth, K.H.; Kivekaes, L.; Ruskeeniemi, T.; Melamed, A.; Siitari-Kauppi, M.

    1996-09-01

    An interlaboratory comparison study was conducted for the available Finnish methods of rock matrix porosity measurements. The aim was first to compare different experimental methods for future applications, and second to obtain quality assured data for the needs of matrix diffusion modelling. Three different versions of water immersion techniques, a tracer elution method, a helium gas through-diffusion method, and a C-14-PMMA method were tested. All methods selected for this study were established experimental tools in the respective laboratories, and they had already been individually tested. Rock samples for the study were obtained from a homogeneous granitic drill core section from the natural analogue site at Palmottu. The drill core section was cut into slabs that were expected to be practically identical. The subsamples were then circulated between the different laboratories using a round robin approach. The circulation was possible because all methods were non-destructive, except the C-14-PMMA method, which was always the last method to be applied. The possible effect of drying temperature on the measured porosity was also preliminarily tested. These measurements were done in the order of increasing drying temperature. Based on the study, it can be concluded that all methods are comparable in their accuracy. The selection of methods for future applications can therefore be based on practical considerations. Drying temperature seemed to have very little effect on the measured porosity, but a more detailed study is needed for definite conclusions. (author) (4 refs.)

  6. Comparison of Thermal Properties Measured by Different Methods

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Jan [Geo Innova AB, Linkoeping (Sweden); Kukkonen, Ilmo [Geological Survey of Finland, Helsinki (Finland); Haelldahl, Lars [Hot Disk AB, Uppsala (Sweden)

    2003-04-01

    A strategy for a thermal site descriptive model of bedrock is under development at SKB. In the model different kinds of uncertainties exist. Some of these uncertainties are related to the potential errors in the methods used for determining thermal properties of rock. In two earlier investigations thermal properties of rock samples were analysed according to the TPS method (transient plane source). Thermal conductivity and thermal diffusivity were determined using the TPS method. For a comparison, the same samples have been measured at the Geological Survey of Finland (GSF), using different laboratory methods. In this later investigation, the thermal conductivity was determined using the divided-bar method and the specific heat capacity using a calorimetric method. The mean differences between the results of different methods are relatively low but the results of individual samples show large variations. The thermal conductivity measured by the divided bar method gives for most samples slightly higher values, in average about 3%, than the TPS method. The specific heat capacity measured by the calorimetric method gives lower values, in average about 2%, than the TPS method. Consequently, the thermal diffusivity calculated from thermal conductivity and specific heat capacity gives higher values, in average about 6%, than the TPS method. Reasons for the differences are estimated mainly to be dependent on differences between the samples, errors in the temperature dependence of specific heat and in the transformation from volumetric to specific heat. The TPS measurements are performed using two pieces (sub-samples) of rock. Only one of these two sub-samples was measured using the divided bar method and the calorimetric method. Further, sample preparation involved changes in the size of some of the samples. The mean differences between the results of different methods are within the margins of error reported by the measuring laboratories. However, systematic errors in

  7. Comparison of Thermal Properties Measured by Different Methods

    International Nuclear Information System (INIS)

    Sundberg, Jan; Kukkonen, Ilmo; Haelldahl, Lars

    2003-04-01

    A strategy for a thermal site descriptive model of bedrock is under development at SKB. In the model different kinds of uncertainties exist. Some of these uncertainties are related to the potential errors in the methods used for determining thermal properties of rock. In two earlier investigations thermal properties of rock samples were analysed according to the TPS method (transient plane source). Thermal conductivity and thermal diffusivity were determined using the TPS method. For a comparison, the same samples have been measured at the Geological Survey of Finland (GSF), using different laboratory methods. In this later investigation, the thermal conductivity was determined using the divided-bar method and the specific heat capacity using a calorimetric method. The mean differences between the results of different methods are relatively low but the results of individual samples show large variations. The thermal conductivity measured by the divided bar method gives for most samples slightly higher values, in average about 3%, than the TPS method. The specific heat capacity measured by the calorimetric method gives lower values, in average about 2%, than the TPS method. Consequently, the thermal diffusivity calculated from thermal conductivity and specific heat capacity gives higher values, in average about 6%, than the TPS method. Reasons for the differences are estimated mainly to be dependent on differences between the samples, errors in the temperature dependence of specific heat and in the transformation from volumetric to specific heat. The TPS measurements are performed using two pieces (sub-samples) of rock. Only one of these two sub-samples was measured using the divided bar method and the calorimetric method. Further, sample preparation involved changes in the size of some of the samples. The mean differences between the results of different methods are within the margins of error reported by the measuring laboratories. However, systematic errors in

  8. Impact of a person-centred dementia care training programme on hospital staff attitudes, role efficacy and perceptions of caring for people with dementia: A repeated measures study.

    Science.gov (United States)

    Surr, C A; Smith, S J; Crossland, J; Robins, J

    2016-01-01

    People with dementia occupy up to one quarter of acute hospital beds. However, the quality of care delivered to this patient group is of national concern. Staff working in acute hospitals report lack of knowledge, skills and confidence in caring for people with dementia. There is limited evidence about the most effective approaches to supporting acute hospital staff to deliver more person-centred care. This study aimed to evaluate the efficacy of a specialist training programme for acute hospital staff regarding improving attitudes, satisfaction and feelings of caring efficacy, in provision of care to people with dementia. A repeated measures design, with measures completed immediately prior to commencing training (T1), after completion of Foundation level training (T2: 4-6 weeks post-baseline), and following Intermediate level training (T3: 3-4 months post-baseline). One NHS Trust in the North of England, UK. 40 acute hospital staff working in clinical roles, the majority of whom (90%) were nurses. All participants received the 3.5 day Person-centred Care Training for Acute Hospitals (PCTAH) programme, comprised of two levels, Foundation (0.5 day) and Intermediate (3 days), delivered over a 3-4 months period. Staff demographics and previous exposure to dementia training were collected via a questionnaire. Staff attitudes were measured using the Approaches to Dementia Questionnaire (ADQ), satisfaction in caring for people with dementia was captured using the Staff Experiences of Working with Demented Residents questionnaire (SEWDR) and perceived caring efficacy was measured using the Caring Efficacy Scale (CES). The training programme was effective in producing a significant positive change on all three outcome measures following intermediate training compared to baseline. A significant positive effect was found on the ADQ between baseline and after completion of Foundation level training, but not for either of the other measures. Training acute hospital staff in

  9. [Methods of measuring telomere length and telomerase activity--practice and problems].

    Science.gov (United States)

    Saito, Y; Suda, T; Hatakeyama, K

    1998-05-01

    The development of a highly sensitive method for detection of telomerase activity, telomeric repeat amplification protocol (TRAP), has provided knowledge on telomerase activity in normal and cancer tissues. Subsequent several modifications have been achieved, including an introduction of the internal standard and hybridization protection technique that leads to simplicity and improvement of reproducibility and linearity of this method, and application of TRAP to in situ analysis to identify the cells responsible for telomerase activity. As for measurement of telomere length, fluorescence in situ hybridization technique appeared to give an information of telomere length on an individual chromosome in contrast to analysis of terminal restriction fragment, a conventional method which can express mean telomere length of all chromosomes. Further methodological improvement in this field is ongoing and showing a new sight on cell mortality and immortality.

  10. Validation of a dual-isotope plasma ratio method for measurement of cholesterol absorption in rats

    International Nuclear Information System (INIS)

    Zilversmit, D.B.; Hughes, L.B.

    1974-01-01

    Several methods for measuring cholesterol absorption in the rat have been compared. After administration of an oral dose of labeled cholesterol ( 14 C or 3 H) and an intravenous dose of colloidal labeled cholesterol ( 3 H or 14 C) the ratio of the two labels in plasma or whole blood 48 hr or more after dosing compared closely to the ratio of areas under the respective specific activity-time curves. The area ratio method is independent of a time lag between the appearance of oral and intravenous label in the bloodstream. Both measures of cholesterol absorption agree fairly well with a method based on measuring the unabsorbed dietary cholesterol in a pooled fecal sample. The plasma isotope ratio method gave more reproducible results than the fecal collection method when the measurement was repeated in the same animals 5 days after the first measurement. Cholesterol absorption was overestimated by the use of Tween 20-solubilized labeled cholesterol for the intravenous dose. The plasma disappearance curves of injected labeled colloidal cholesterol and cholesterol-labeled chylomicrons infused intravenously over a 3.5-h period in the same animal coincided within experimental error from the first day until 75 days after injection. The plasma isotope ratio method for cholesterol absorption gave the same results in rats practicing coprophagy as in those in which this practice was prevented. The addition of sulfaguanidine to the diet lowered cholesterol absorption as measured by the plasma isotope ratio to the same degree as that measured by the fecal collection method. (U.S.)

  11. Using the American alligator and a repeated-measures design to place constraints on in vivo shoulder joint range of motion in dinosaurs and other fossil archosaurs.

    Science.gov (United States)

    Hutson, Joel D; Hutson, Kelda N

    2013-01-15

    Using the extant phylogenetic bracket of dinosaurs (crocodylians and birds), recent work has reported that elbow joint range of motion (ROM) studies of fossil dinosaur forearms may be providing conservative underestimates of fully fleshed in vivo ROM. As humeral ROM occupies a more central role in forelimb movements, the placement of quantitative constraints on shoulder joint ROM could improve fossil reconstructions. Here, we investigated whether soft tissues affect the more mobile shoulder joint in the same manner in which they affect elbow joint ROM in an extant archosaur. This test involved separately and repeatedly measuring humeral ROM in Alligator mississippiensis as soft tissues were dissected away in stages to bare bone. Our data show that the ROMs of humeral flexion and extension, as well as abduction and adduction, both show a statistically significant increase as flesh is removed, but then decrease when the bones must be physically articulated and moved until they separate from one another and/or visible joint surfaces. A similar ROM pattern is inferred for humeral pronation and supination. All final skeletonized ROMs were less than initial fully fleshed ROMs. These results are consistent with previously reported elbow joint ROM patterns from the extant phylogenetic bracket of dinosaurs. Thus, studies that avoid separation of complementary articular surfaces may be providing fossil shoulder joint ROMs that underestimate in vivo ROM in dinosaurs, as well as other fossil archosaurs.

  12. The Queensland study of Melanoma: Environmental and Genetic Associations (Q-MEGA). Study design, baseline characteristics, and repeatability of phenotype and sun exposure measures

    Science.gov (United States)

    Baxter, Amanda J.; Hughes, Maria Celia; Kvaskoff, Marina; Siskind, Victor; Shekar, Sri; Aitken, Joanne F.; Green, Adele C.; Duffy, David L.; Hayward, Nicholas K.; Martin, Nicholas G.; Whiteman, David C.

    2013-01-01

    Cutaneous malignant melanoma (CMM) is a major health issue in Queensland, Australia which has the world’s highest incidence. Recent molecular and epidemiologic studies suggest that CMM arises through multiple etiological pathways involving gene-environment interactions. Understanding the potential mechanisms leading to CMM requires larger studies than those previously conducted. This article describes the design and baseline characteristics of Q-MEGA, the Queensland study of Melanoma: Environmental and Genetic Associations, which followed-up four population-based samples of CMM patients in Queensland, including children, adolescents, men aged over 50, and a large sample of adult cases and their families, including twins. Q-MEGA aims to investigate the roles of genetic and environmental factors, and their interaction, in the etiology of melanoma. 3,471 participants took part in the follow-up study and were administered a computer-assisted telephone interview in 2002–2005. Updated data on environmental and phenotypic risk factors, and 2,777 blood samples were collected from interviewed participants as well as a subset of relatives. This study provides a large and well-described population-based sample of CMM cases with follow-up data. Characteristics of the cases and repeatability of sun exposure and phenotype measures between the baseline and the follow-up surveys, from six to 17 years later, are also described. PMID:18361720

  13. The estimation of the measurement results with using statistical methods

    International Nuclear Information System (INIS)

    Ukrmetrteststandard, 4, Metrologichna Str., 03680, Kyiv (Ukraine))" data-affiliation=" (State Enterprise Ukrmetrteststandard, 4, Metrologichna Str., 03680, Kyiv (Ukraine))" >Velychko, O; UkrNDIspirtbioprod, 3, Babushkina Lane, 03190, Kyiv (Ukraine))" data-affiliation=" (State Scientific Institution UkrNDIspirtbioprod, 3, Babushkina Lane, 03190, Kyiv (Ukraine))" >Gordiyenko, T

    2015-01-01

    The row of international standards and guides describe various statistical methods that apply for a management, control and improvement of processes with the purpose of realization of analysis of the technical measurement results. The analysis of international standards and guides on statistical methods estimation of the measurement results recommendations for those applications in laboratories is described. For realization of analysis of standards and guides the cause-and-effect Ishikawa diagrams concerting to application of statistical methods for estimation of the measurement results are constructed

  14. The estimation of the measurement results with using statistical methods

    Science.gov (United States)

    Velychko, O.; Gordiyenko, T.

    2015-02-01

    The row of international standards and guides describe various statistical methods that apply for a management, control and improvement of processes with the purpose of realization of analysis of the technical measurement results. The analysis of international standards and guides on statistical methods estimation of the measurement results recommendations for those applications in laboratories is described. For realization of analysis of standards and guides the cause-and-effect Ishikawa diagrams concerting to application of statistical methods for estimation of the measurement results are constructed.

  15. Laser triangulation method for measuring the size of parking claw

    Science.gov (United States)

    Liu, Bo; Zhang, Ming; Pang, Ying

    2017-10-01

    With the development of science and technology and the maturity of measurement technology, the 3D profile measurement technology has been developed rapidly. Three dimensional measurement technology is widely used in mold manufacturing, industrial inspection, automatic processing and manufacturing, etc. There are many kinds of situations in scientific research and industrial production. It is necessary to transform the original mechanical parts into the 3D data model on the computer quickly and accurately. At present, many methods have been developed to measure the contour size, laser triangulation is one of the most widely used methods.

  16. Characteristics and correlation of various radiation measuring methods in spatial radiation measurement

    International Nuclear Information System (INIS)

    Yoneda, Kazuhiro; Tonouchi, Shigemasa

    1992-01-01

    When the survey of the state of natural radiation distribution was carried out, for the purpose of examining the useful measuring method, the comparison of the γ-ray dose rate calculated from survey meter method, in-situ measuring method and the measuring method by sampling soil was carried out. Between the in-situ measuring method and the survey meter method, the correlation Y=0.986X+5.73, r=0.903, n=18, P<0.01 was obtained, and the high correlation having the inclination of nearly 1 was shown. Between the survey meter method and the measuring method by sampling soil, the correlation Y=1.297X-10.30, r=0.966, n=20 P<0.01 was obtained, and the high correlation was shown, but as for the dose rate contribution, the disparities of 36% in U series, 6% in Th series and 20% in K-40 were observed. For the survey of the state of natural radiation distribution, the method of using in combination the survey meter method and the in-situ measuring method or the measuring method by sampling soil is suitable. (author)

  17. Radon in indoor air. Health risk, measurement methods and remedial measures

    International Nuclear Information System (INIS)

    Strand, T.

    1996-02-01

    Radon in indoor air is the main source of ionizing radiation in Norway. The booklet contains a presentation of radon sources, measurement methods, indoor radon concentrations, action levels, health risk and remedial measures

  18. Separability criteria and method of measurement for entanglement

    Science.gov (United States)

    Mohd, Siti Munirah; Idrus, Bahari; Mukhtar, Muriati

    2014-06-01

    Quantum computers have the potentials to solve certain problems faster than classical computers. In quantum computer, entanglement is one of the elements beside superposition. Recently, with the advent of quantum information theory, entanglement has become an important resource for Quantum Information and Computation. The purpose of this paper is to discuss the separability criteria and method of measurement for entanglement. This paper is aimed at viewing the method that has been proposed in previous works in bipartite and multipartite entanglement. The outcome of this paper is to classify the different method that used to measure entanglement for bipartite and multipartite cases including the advantage and disadvantage of each method.

  19. Separability criteria and method of measurement for entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Mohd, Siti Munirah; Idrus, Bahari; Mukhtar, Muriati [Industrial Computing Research Group, Faculty of Information Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2014-06-19

    Quantum computers have the potentials to solve certain problems faster than classical computers. In quantum computer, entanglement is one of the elements beside superposition. Recently, with the advent of quantum information theory, entanglement has become an important resource for Quantum Information and Computation. The purpose of this paper is to discuss the separability criteria and method of measurement for entanglement. This paper is aimed at viewing the method that has been proposed in previous works in bipartite and multipartite entanglement. The outcome of this paper is to classify the different method that used to measure entanglement for bipartite and multipartite cases including the advantage and disadvantage of each method.

  20. Separability criteria and method of measurement for entanglement

    International Nuclear Information System (INIS)

    Mohd, Siti Munirah; Idrus, Bahari; Mukhtar, Muriati

    2014-01-01

    Quantum computers have the potentials to solve certain problems faster than classical computers. In quantum computer, entanglement is one of the elements beside superposition. Recently, with the advent of quantum information theory, entanglement has become an important resource for Quantum Information and Computation. The purpose of this paper is to discuss the separability criteria and method of measurement for entanglement. This paper is aimed at viewing the method that has been proposed in previous works in bipartite and multipartite entanglement. The outcome of this paper is to classify the different method that used to measure entanglement for bipartite and multipartite cases including the advantage and disadvantage of each method

  1. L-C Measurement Acquisition Method for Aerospace Systems

    Science.gov (United States)

    Woodard, Stanley E.; Taylor, B. Douglas; Shams, Qamar A.; Fox, Robert L.

    2003-01-01

    This paper describes a measurement acquisition method for aerospace systems that eliminates the need for sensors to have physical connection to a power source (i.e., no lead wires) or to data acquisition equipment. Furthermore, the method does not require the sensors to be in proximity to any form of acquisition hardware. Multiple sensors can be interrogated using this method. The sensors consist of a capacitor, C(p), whose capacitance changes with changes to a physical property, p, electrically connected to an inductor, L. The method uses an antenna to broadcast electromagnetic energy that electrically excites one or more inductive-capacitive sensors via Faraday induction. This method facilitates measurements that were not previously possible because there was no practical means of providing power and data acquisition electrical connections to a sensor. Unlike traditional sensors, which measure only a single physical property, the manner in which the sensing element is interrogated simultaneously allows measurement of at least two unrelated physical properties (e.g., displacement rate and fluid level) by using each constituent of the L-C element. The key to using the method for aerospace applications is to increase the distance between the L-C elements and interrogating antenna; develop all key components to be non-obtrusive and to develop sensing elements that can easily be implemented. Techniques that have resulted in increased distance between antenna and sensor will be presented. Fluid-level measurements and pressure measurements using the acquisition method are demonstrated in the paper.

  2. Effect of exposure to evening light on sleep initiation in the elderly: a longitudinal analysis for repeated measurements in home settings.

    Science.gov (United States)

    Obayashi, Kenji; Saeki, Keigo; Iwamoto, Junko; Okamoto, Nozomi; Tomioka, Kimiko; Nezu, Satoko; Ikada, Yoshito; Kurumatani, Norio

    2014-05-01

    Epidemiologic data have demonstrated associations of sleep-onset insomnia with a variety of diseases, including depression, dementia, diabetes and cardiovascular diseases. Sleep initiation is controlled by the suprachiasmatic nucleus of the hypothalamus and endogenous melatonin, both of which are influenced by environmental light. Exposure to evening light is hypothesized to cause circadian phase delay and melatonin suppression before bedtime, resulting in circadian misalignment and sleep-onset insomnia; however, whether exposure to evening light disturbs sleep initiation in home settings remains unclear. In this longitudinal analysis of 192 elderly individuals (mean age: 69.9 years), we measured evening light exposure and sleep-onset latency for 4 days using a wrist actigraph incorporating a light meter and an accelerometer. Mixed-effect linear regression analysis for repeated measurements was used to evaluate the effect of evening light exposure on subsequent sleep-onset latency. The median intensity of evening light exposure and the median sleep-onset latency were 27.3 lux (interquartile range, 17.9-43.4) and 17 min (interquartile range, 7-33), respectively. Univariate models showed significant associations between sleep-onset latency and age, gender, daytime physical activity, in-bed time, day length and average intensity of evening and nighttime light exposures. In a multivariate model, log-transformed average intensity of evening light exposure was significantly associated with log-transformed sleep-onset latency independent of the former potential confounding factors (regression coefficient, 0.133; 95% CI, 0.020-0.247; p = 0.021). Day length and nighttime light exposure were also significantly associated with log-transformed sleep-onset latency (p = 0.001 and p < 0.001, respectively). In conclusion, exposure to evening light in home setting prolongs subsequent sleep-onset latency in the elderly.

  3. Telomere shortening unrelated to smoking, body weight, physical activity, and alcohol intake: 4,576 general population individuals with repeat measurements 10 years apart.

    Directory of Open Access Journals (Sweden)

    Maren Weischer

    2014-03-01

    Full Text Available Cross-sectional studies have associated short telomere length with smoking, body weight, physical activity, and possibly alcohol intake; however, whether these associations are due to confounding is unknown. We tested these hypotheses in 4,576 individuals from the general population cross-sectionally, and with repeat measurement of relative telomere length 10 years apart. We also tested whether change in telomere length is associated with mortality and morbidity in the general population. Relative telomere length was measured with quantitative polymerase chain reaction. Cross-sectionally at the first examination, short telomere length was associated with increased age (P for trend across quartiles = 3 × 10(-77, current smoking (P = 8 × 10(-3, increased body mass index (P = 7 × 10(-14, physical inactivity (P = 4 × 10(-17, but not with increased alcohol intake (P = 0.10. At the second examination 10 years later, 56% of participants had lost and 44% gained telomere length with a mean loss of 193 basepairs. Change in leukocyte telomere length during 10 years was associated inversely with baseline telomere length (P<1 × 10(-300 and age at baseline (P = 1 × 10(-27, but not with baseline or 10-year inter-observational tobacco consumption, body weight, physical activity, or alcohol intake. Prospectively during a further 10 years follow-up after the second examination, quartiles of telomere length change did not associate with risk of all-cause mortality, cancer, chronic obstructive pulmonary disease, diabetes mellitus, ischemic cerebrovascular disease, or ischemic heart disease. In conclusion, smoking, increased body weight, and physical inactivity were associated with short telomere length cross-sectionally, but not with telomere length change during 10 years observation, and alcohol intake was associated with neither. Also, change in telomere length did not associate prospectively with mortality or morbidity in the general population.

  4. Methods, measures and indicators for evaluating benefits of transportation research

    CSIR Research Space (South Africa)

    Du Plessis, Louw

    2016-04-01

    Full Text Available The purpose of this article is to provide updated information by identifying and discussing methods, measures and indicators for evaluating benefits appropriate for transportation-related research facilities/programmes. The information has been...

  5. Measuring methods, registration and signal processing for magnetic field research

    International Nuclear Information System (INIS)

    Nagiello, Z.

    1981-01-01

    Some measuring methods and signal processing systems based on analogue and digital technics, which have been applied in magnetic field research using magnetometers with ferromagnetic transducers, are presented. (author)

  6. Several cases of electronics and the measuring methods

    International Nuclear Information System (INIS)

    Supardiyono, Bb.; Kamadi, J.; Suparmono, M.; Indarto.

    1980-01-01

    Several cases of electronics and the measuring methods, covering electric conductivity and electric potential of analog systems, electric current, electric conductivity and electric potential of semiconductor diodes, and characteristics of transistors are described. (SMN)

  7. Measuring trace elements in semiconductors: methods and pitfalls

    Energy Technology Data Exchange (ETDEWEB)

    Lindstrom, R M

    1980-02-01

    Some of the principles which govern the analytic methods available for the detection and quantitative measurement of impurity concentrations in semiconductors are described. Ways of assuring the quality of analytical data are suggested. (SPH)

  8. Validation of Standing Wave Liner Impedance Measurement Method, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Hersh Acoustical Engineering, Inc. proposes to establish the feasibility and practicality of using the Standing Wave Method (SWM) to measure the impedance of...

  9. Multivariate Methods Based Soft Measurement for Wine Quality Evaluation

    Directory of Open Access Journals (Sweden)

    Shen Yin

    2014-01-01

    a decision. However, since the physicochemical indexes of wine can to some extent reflect the quality of wine, the multivariate statistical methods based soft measure can help the oenologist in wine evaluation.

  10. Development of measure methods of radon in indoor air

    International Nuclear Information System (INIS)

    Yaginuma, L.T.; Pela, C.A.; Navas, E.A.; Ghilardi, A.J.P.

    1992-01-01

    The development of some conventional measuring methods, aiming obtain an estimation of radon concentration in air, mainly in indoor air is described, including the charcoal absorption collector, Lucas cell and thermoluminescent dosemeters. (C.G.C)

  11. A Fast and Robust Method for Measuring Optical Channel Gain

    DEFF Research Database (Denmark)

    Harbo, Anders La-Cour; Stoustrup, Jakob; Villemoes, L.F.

    2000-01-01

    We present a numerically stable and computational simple method for fast and robust measurement of optical channel gain. By transmitting adaptively designed signals through the channel, good accuracy is possible even in severe noise conditions......We present a numerically stable and computational simple method for fast and robust measurement of optical channel gain. By transmitting adaptively designed signals through the channel, good accuracy is possible even in severe noise conditions...

  12. Measurement of ion energy by a calorimetric method

    Energy Technology Data Exchange (ETDEWEB)

    Mizuhashi, Kiyoshi; Tajima, Satoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Bunak, Suwat

    1996-12-01

    In calorimetric method, ion energy is determined based on the temperature changes during radiation of an absorbing material, radiation current and heat capacity of the calorimeter. This method is convenient and its measuring procedures are simple as well as the measuring apparatus. Here, the temperature changes of the calorimeter during {sup 14}N ion beam radiation were determined. The temperature increased linearly when irradiated with {sup 14}N{sup 3+}, 8.3 MeV or {sup 14}N{sup 2+}, 6 MeV, but not linearly for {sup 14}N{sup 1+}, 3.6 MeV, resulting in a comparatively large error. Thus, the measurement of ion energy by calorimetric method was found available as a convenient method for an accelerator having an energy stability less than 10{sup -3}. Especially this method seems to be useful for low-energy ion accelerator or ion injecting apparatus. (M.N.)

  13. Wettability measurements of irregular shapes with Wilhelmy plate method

    Science.gov (United States)

    Park, Jaehyung; Pasaogullari, Ugur; Bonville, Leonard

    2018-01-01

    One of the most accurate methods for measuring the dynamic contact angle of liquids on solid surfaces is the Wilhelmy plate method. This method generally requires the use of rectangular samples having a constant perimeter in the liquid during advancing and receding cycles. A new formulation based on the Wilhelmy force balance equation to determine the contact angle for plate samples with irregular shapes has been developed. This method employs a profile plot obtained from an optical image to determine the perimeter (i.e. wetted length) of the sample as a function of the immersion depth. The raw force data measured by the force tensiometer is manipulated using the profile plot and the Wilhelmy equation to determine the wetting force and consequently advancing and the receding contact angle. This method is verified with both triangular and irregular PTFE samples in water, and measured contact angles are in good agreement with results from conventional regular shaped samples with a constant perimeter.

  14. Assessment and comparison of methods for solar ultraviolet radiation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Leszczynski, K

    1995-06-01

    In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented. (62 refs.).

  15. Measurement of unattached radon progeny based in electrostatic deposition method

    International Nuclear Information System (INIS)

    Canoba, A.C.; Lopez, F.O.

    1999-01-01

    A method for the measurement of unattached radon progeny based on its electrostatic deposition onto wire screens, using only one pump, has been implemented and calibrated. The importance of being able of making use of this method is related with the special radiological significance that has the unattached fraction of the short-lived radon progeny. Because of this, the assessment of exposure could be directly related to dose with far greater accuracy than before. The advantages of this method are its simplicity, even with the tools needed for the sample collection, as well as the measurement instruments used. Also, the suitability of this method is enhanced by the fact that it can effectively be used with a simple measuring procedure such as the Kusnetz method. (author)

  16. Interval sampling methods and measurement error: a computer simulation.

    Science.gov (United States)

    Wirth, Oliver; Slaven, James; Taylor, Matthew A

    2014-01-01

    A simulation study was conducted to provide a more thorough account of measurement error associated with interval sampling methods. A computer program simulated the application of momentary time sampling, partial-interval recording, and whole-interval recording methods on target events randomly distributed across an observation period. The simulation yielded measures of error for multiple combinations of observation period, interval duration, event duration, and cumulative event duration. The simulations were conducted up to 100 times to yield measures of error variability. Although the present simulation confirmed some previously reported characteristics of interval sampling methods, it also revealed many new findings that pertain to each method's inherent strengths and weaknesses. The analysis and resulting error tables can help guide the selection of the most appropriate sampling method for observation-based behavioral assessments. © Society for the Experimental Analysis of Behavior.

  17. Assessment and comparison of methods for solar ultraviolet radiation measurements

    International Nuclear Information System (INIS)

    Leszczynski, K.

    1995-06-01

    In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented. (62 refs.)

  18. Very low frequency earthquakes (VLFEs) detected during episodic tremor and slip (ETS) events in Cascadia using a match filter method indicate repeating events

    Science.gov (United States)

    Hutchison, A. A.; Ghosh, A.

    2016-12-01

    Very low frequency earthquakes (VLFEs) occur in transitional zones of faults, releasing seismic energy in the 0.02-0.05 Hz frequency band over a 90 s duration and typically have magntitudes within the range of Mw 3.0-4.0. VLFEs can occur down-dip of the seismogenic zone, where they can transfer stress up-dip potentially bringing the locked zone closer to a critical failure stress. VLFEs also occur up-dip of the seismogenic zone in a region along the plate interface that can rupture coseismically during large megathrust events, such as the 2011 Tohoku-Oki earthquake [Ide et al., 2011]. VLFEs were first detected in Cascadia during the 2011 episodic tremor and slip (ETS) event, occurring coincidentally with tremor [Ghosh et al., 2015]. However, during the 2014 ETS event, VLFEs were spatially and temporally asynchronous with tremor activity [Hutchison and Ghosh, 2016]. Such contrasting behaviors remind us that the mechanics behind such events remain elusive, yet they are responsible for the largest portion of the moment release during an ETS event. Here, we apply a match filter method using known VLFEs as template events to detect additional VLFEs. Using a grid-search centroid moment tensor inversion method, we invert stacks of the resulting match filter detections to ensure moment tensor solutions are similar to that of the respective template events. Our ability to successfully employ a match filter method to VLFE detection in Cascadia intrinsically indicates that these events can be repeating, implying that the same asperities are likely responsible for generating multiple VLFEs.

  19. Radon Measurement Proficiency (RMP) Program methods and devices

    International Nuclear Information System (INIS)

    Harrison, J.; Hoornbeek, J.; Jalbert, P.; Sensintaffar, E.; Hopper, R.

    1991-01-01

    The US EPA developed the voluntary Radon Measurement Proficiency Program in 1986 in response to a Federal and State need for measurement services firms to demonstrate their proficiency with radon measurement methods and devices. Since that time, the program has set basic standards for the radon measurement industry. The program has grown dramatically since its inception. In 1986, fewer than 50 companies participated in the program. By 1989, more than 5,000 companies were participating. Participants represent firms with an analytical capability as well as firms that rely upon another firm for analysis service. Since the beginning of the RMP Program, the Agency has learned a great deal about radon measurement methods and devices. This paper reviews the measurement devices used in the program and what the EPA has learned about them since the program's inception. Performance data from the RMP Program are used to highlight relevant findings

  20. A method for quantitative measurement of lumbar intervertebral disc structures

    DEFF Research Database (Denmark)

    Tunset, Andreas; Kjær, Per; Samir Chreiteh, Shadi

    2013-01-01

    There is a shortage of agreement studies relevant for measuring changes over time in lumbar intervertebral disc structures. The objectives of this study were: 1) to develop a method for measurement of intervertebral disc height, anterior and posterior disc material and dural sac diameter using MR...

  1. A radiographic method for measurement of leg length inequality.

    Science.gov (United States)

    Friberg, O; Koivisto, E; Wegelius, C

    1985-01-01

    An accurate and simple radiographic method for the measurement of weight-bearing leg length inequality with a minimum of radiated body area is described. The measurement can be made in a conventional chest X-ray unit without other extra equipment than a gonad shield described here.

  2. A four-probe thermal transport measurement method for nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jaehyun; Ou, Eric; Sellan, Daniel P.; Shi, Li, E-mail: lishi@mail.utexas.edu [Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States)

    2015-04-15

    Several experimental techniques reported in recent years have enabled the measurement of thermal transport properties of nanostructures. However, eliminating the contact thermal resistance error from the measurement results has remained a critical challenge. Here, we report a different four-probe measurement method that can separately obtain both the intrinsic thermal conductance and the contact thermal resistance of individual nanostructures. The measurement device consists of four microfabricated, suspended metal lines that act as resistive heaters and thermometers, across which the nanostructure sample is assembled. The method takes advantage of the variation in the heat flow along the suspended nanostructure and across its contacts to the four suspended heater and thermometer lines, and uses sixteen sets of temperature and heat flow measurements to obtain nine of the thermal resistances in the measurement device and the nanostructure sample, including the intrinsic thermal resistance and the two contact thermal resistances to the middle suspended segment of the nanostructure. Two single crystalline Si nanowires with different cross sections are measured in this work to demonstrate the effectiveness of the method. This four-probe thermal transport measurement method can lead to future discoveries of unique size-dependent thermal transport phenomena in nanostructures and low-dimensional materials, in addition to providing reliable experimental data for calibrating theoretical models.

  3. Social Capital in Western and Eastern Europe: Method of Measurement

    DEFF Research Database (Denmark)

    Hjøllund, L.; Svendsen, Gert Tinggaard

    2000-01-01

    The purpose of this paper is to suggest a standard method of measurement for social capital. Various authors have investigated the influence of social capital on economic growth but still social capital has not been measured in any satisfactory way. So far, each survey has used its own ad hoc met...

  4. Cavitation, subcooled boiling and a measuring method developed at ENEA

    International Nuclear Information System (INIS)

    Tirelli, D.

    1988-01-01

    A brief description of cavitation and subcooled boiling is reported; their effects, measuring methods, operating limits and prescribed standards are described. The whole, to better clarify the usefulness and the importance of a measuring instrument developed at ENEA, to study the above phenomena

  5. Method of measuring the degree of fluid pollution

    International Nuclear Information System (INIS)

    Mortensen, A.; Hammer, E.A.

    1995-01-01

    The invention relates to an method and device for measuring the degree of pollution from particulates in fluids. The device consists of an emitter sending out green and red light in succession through the fluid to a light recorder. The recorder itself includes a unit designed for comparing the measured intensity of light with the values of known pollution degree in fluids. 2 figs

  6. A four-probe thermal transport measurement method for nanostructures

    International Nuclear Information System (INIS)

    Kim, Jaehyun; Ou, Eric; Sellan, Daniel P.; Shi, Li

    2015-01-01

    Several experimental techniques reported in recent years have enabled the measurement of thermal transport properties of nanostructures. However, eliminating the contact thermal resistance error from the measurement results has remained a critical challenge. Here, we report a different four-probe measurement method that can separately obtain both the intrinsic thermal conductance and the contact thermal resistance of individual nanostructures. The measurement device consists of four microfabricated, suspended metal lines that act as resistive heaters and thermometers, across which the nanostructure sample is assembled. The method takes advantage of the variation in the heat flow along the suspended nanostructure and across its contacts to the four suspended heater and thermometer lines, and uses sixteen sets of temperature and heat flow measurements to obtain nine of the thermal resistances in the measurement device and the nanostructure sample, including the intrinsic thermal resistance and the two contact thermal resistances to the middle suspended segment of the nanostructure. Two single crystalline Si nanowires with different cross sections are measured in this work to demonstrate the effectiveness of the method. This four-probe thermal transport measurement method can lead to future discoveries of unique size-dependent thermal transport phenomena in nanostructures and low-dimensional materials, in addition to providing reliable experimental data for calibrating theoretical models

  7. DEVELOPMENT OF EVALUATION OF A QUANTITATIVE VIDEO-FLUORESCENCE IMAGING SYSTEM AND FLUORESCENT TRACER FOR MEASURING TRANSFER OF PESTICIDE RESIDUES FROM SURFACES TO HANDS WITH REPEATED CONTACTS

    Science.gov (United States)

    A video imaging system and the associated quantification methods have been developed for measurement of the transfers of a fluorescent tracer from surfaces to hands. The highly fluorescent compound riboflavin (Vitamin B2), which is also water soluble and non-toxic, was chosen as...

  8. Safety of Repeated Yttrium-90 Radioembolization

    International Nuclear Information System (INIS)

    Lam, Marnix G. E. H.; Louie, John D.; Iagaru, Andrei H.; Goris, Michael L.; Sze, Daniel Y.

    2013-01-01

    Purpose: Repeated radioembolization (RE) treatments carry theoretically higher risk of radiation-induced hepatic injury because of the liver’s cumulative memory of previous exposure. We performed a retrospective safety analysis on patients who underwent repeated RE. Methods: From 2004 to 2011, a total of 247 patients were treated by RE. Eight patients (5 men, 3 women, age range 51–71 years) underwent repeated treatment of a targeted territory, all with resin microspheres (SIR-Spheres; Sirtex, Lane Cove, Australia). Adverse events were graded during a standardized follow-up. In addition, the correlation between the occurrence of RE-induced liver disease (REILD) and multiple variables was investigated in univariate and multivariate analyses in all 247 patients who received RE. Results: Two patients died shortly after the second treatment (at 84 and 107 days) with signs and symptoms of REILD. Both patients underwent whole liver treatment twice (cumulative doses 3.08 and 2.66 GBq). The other 6 patients demonstrated only minor toxicities after receiving cumulative doses ranging from 2.41 to 3.88 GBq. All patients experienced objective tumor responses. In the whole population, multifactorial analysis identified three risk factors associated with REILD: repeated RE (p = 0.036), baseline serum total bilirubin (p = 0.048), and baseline serum aspartate aminotransferase (p = 0.043). Repeated RE proved to be the only independent risk factor for REILD in multivariate analysis (odds ratio 9.6; p = 0.002). Additionally, the administered activity per target volume (in GBq/L) was found to be an independent risk factor for REILD, but only in whole liver treatments (p = 0.033). Conclusion: The risk of REILD appears to be elevated for repeated RE. Objective tumor responses were observed, but establishment of safety limits will require improvement in dosimetric measurement and prediction

  9. Safety of Repeated Yttrium-90 Radioembolization

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Marnix G. E. H.; Louie, John D. [Stanford University School of Medicine, Division of Interventional Radiology (United States); Iagaru, Andrei H.; Goris, Michael L. [Stanford University School of Medicine, Division of Nuclear Medicine (United States); Sze, Daniel Y., E-mail: dansze@stanford.edu [Stanford University School of Medicine, Division of Interventional Radiology (United States)

    2013-10-15

    Purpose: Repeated radioembolization (RE) treatments carry theoretically higher risk of radiation-induced hepatic injury because of the liver's cumulative memory of previous exposure. We performed a retrospective safety analysis on patients who underwent repeated RE. Methods: From 2004 to 2011, a total of 247 patients were treated by RE. Eight patients (5 men, 3 women, age range 51-71 years) underwent repeated treatment of a targeted territory, all with resin microspheres (SIR-Spheres; Sirtex, Lane Cove, Australia). Adverse events were graded during a standardized follow-up. In addition, the correlation between the occurrence of RE-induced liver disease (REILD) and multiple variables was investigated in univariate and multivariate analyses in all 247 patients who received RE. Results: Two patients died shortly after the second treatment (at 84 and 107 days) with signs and symptoms of REILD. Both patients underwent whole liver treatment twice (cumulative doses 3.08 and 2.66 GBq). The other 6 patients demonstrated only minor toxicities after receiving cumulative doses ranging from 2.41 to 3.88 GBq. All patients experienced objective tumor responses. In the whole population, multifactorial analysis identified three risk factors associated with REILD: repeated RE (p = 0.036), baseline serum total bilirubin (p = 0.048), and baseline serum aspartate aminotransferase (p = 0.043). Repeated RE proved to be the only independent risk factor for REILD in multivariate analysis (odds ratio 9.6; p = 0.002). Additionally, the administered activity per target volume (in GBq/L) was found to be an independent risk factor for REILD, but only in whole liver treatments (p = 0.033). Conclusion: The risk of REILD appears to be elevated for repeated RE. Objective tumor responses were observed, but establishment of safety limits will require improvement in dosimetric measurement and prediction.

  10. Quantitative Assessment of Blood Pressure Measurement Accuracy and Variability from Visual Auscultation Method by Observers without Receiving Medical Training

    Science.gov (United States)

    Feng, Yong; Chen, Aiqing

    2017-01-01

    This study aimed to quantify blood pressure (BP) measurement accuracy and variability with different techniques. Thirty video clips of BP recordings from the BHS training database were converted to Korotkoff sound waveforms. Ten observers without receiving medical training were asked to determine BPs using (a) traditional manual auscultatory method and (b) visual auscultation method by visualizing the Korotkoff sound waveform, which was repeated three times on different days. The measurement error was calculated against the reference answers, and the measurement variability was calculated from the SD of the three repeats. Statistical analysis showed that, in comparison with the auscultatory method, visual method significantly reduced overall variability from 2.2 to 1.1 mmHg for SBP and from 1.9 to 0.9 mmHg for DBP (both p auscultation methods). In conclusion, the visual auscultation method had the ability to achieve an acceptable degree of BP measurement accuracy, with smaller variability in comparison with the traditional auscultatory method. PMID:29423405

  11. Stress measurement and bolt tensioning by ultrasonic methods

    International Nuclear Information System (INIS)

    Smith, J.F.; Greiner, J.D.

    1980-01-01

    In the past decade, a new technique has been developed for measuring tensile stresses in solids. This ultrasonic technique has been used thus far primarily for measuring fastener tension. The precision of measurement is routinely to 2-3% and, with special care, to approx. 1%. The method is insensitive to the frictional losses which plague tensioning by torque wrench. Though the approach is relatively new, it promises a wide range of applicability

  12. Stress Measurement and Bolt Tensioning by Ultrasonic Methods

    Science.gov (United States)

    Smith, J. F.; Greiner, John D.

    1980-07-01

    In the past decade, a new technique has been developed for measuring tensile stresses in solids. This ultrasonic technique has been used thus far primarily for measuring fastener tension. The precision of measurement is routinely to 2-3% and, with special care, to ˜1%. The method is insensitive to the frictional losses which plague tensioning by torque wrench. Though the approach is relatively new, it promises a wide range of applicability.

  13. Comparison of different methods for thoron progeny measurement

    International Nuclear Information System (INIS)

    Bi Lei; Zhu Li; Shang Bing; Cui Hongxing; Zhang Qingzhao

    2009-01-01

    Four popular methods for thoron progeny measurement were discussed, including the aspects of detector,principle, precondition, calculation advantages and disadvantages. Comparison experiments were made in mine and houses with high background in Yunnan Province. Since indoor thoron progeny changes with time obviously and with no rule, α track method is recommended in the area of radiation protection for environmental detection and assessment. (authors)

  14. A Simple and Accurate Method for Measuring Enzyme Activity.

    Science.gov (United States)

    Yip, Din-Yan

    1997-01-01

    Presents methods commonly used for investigating enzyme activity using catalase and presents a new method for measuring catalase activity that is more reliable and accurate. Provides results that are readily reproduced and quantified. Can also be used for investigations of enzyme properties such as the effects of temperature, pH, inhibitors,…

  15. New method of measuring electric dipole moments in storage rings

    NARCIS (Netherlands)

    Farley, FJM; Jungmann, K; Miller, JP; Morse, WM; Orlov, YF; Roberts, BL; Semertzidis, YK; Silenko, A; Stephenson, EJ

    2004-01-01

    A new highly sensitive method of looking for electric dipole moments of charged particles in storage rings is described. The major systematic errors inherent in the method are addressed and ways to minimize them are suggested. It seems possible to measure the muon EDM to levels that test speculative

  16. New radiocarbon measurement methods in the Hertelendi Laboratory, Hungary

    Science.gov (United States)

    Janovics, Róbert; Major, István; Rinyu, László; Veres, Mihály; Molnár, Mihály

    2013-04-01

    In this paper we present two very different and novel methods for C-14 measurement from dissolved inorganic carbonate (DIC) of water samples. A new LSC sample preparation method for liquid scintillation C-14 measurements was implemented in the ATOMKI. The first method uses direct absorption into a special absorbent (Carbosorb E®) and a following liquid scintillation measurement. Typical sample size is 20-40 litre of water. The developed CO2 absorption method is fast, and simple. The C-14 activities is measured by an ultra low background LSC (TRI-CARB 3170 TR/SL, Perkin Elmer) including quenching parameter (tSIE).The corresponding limit of C-14 dating is 31200 year. Several tests were executed with old borehole CO2 gas without significant content of C-14 and also performed on samples of known C-14 activities between 29 and 7000 pMC, previously measured by GPC. The combined uncertainty of the described determination is about 2 % in the case of recent carbon. It is a very cost-effective and easy to use method based on a novel and simple static absorption process for the CO2 extracted from groundwater. The other very sensitive method is based on accelerator mass spectrometry (AMS) using gas ion source. This method does not require graphite generation and a small volume of water sample (1-20mL) is enough for the radiocarbon measurement. The procedure is very similar to pre-treatment of carbonate contained sample preparation for stable isotope measurement with gasbench technique. We applied a MICADAS type accelerator mass spectrometry (AMS) with gas ion source for C-14 analysis. The radiocarbon content of water was sat free with phosphoric acid and then the headspace gas was rinsed vials. The whole measurement needs only 20 min of each sample. The precision of measurement is better than 1% for modern samples. The preparation is vastly reduced compared to the other AMS methods and principally allows fully automated measurements of groundwater samples with an auto

  17. Impulse method for temperature measurement of silicon detectors

    International Nuclear Information System (INIS)

    Kushpil, V.V.; Kushpil, S.A.; Petracek, V.

    1999-01-01

    A new impulse method of temperature measurement based on switching characteristic of the P-N junction is described. Temperature of silicon detector can be determined, due to the strong temperature dependence of minority carrier lifetime, from the charge registered during the switching-off process. The method has been tested in temperature range 25 - 60 deg C. Advantages, drawbacks and precision of this method are discussed

  18. Correlation and agreement of a digital and conventional method to measure arch parameters.

    Science.gov (United States)

    Nawi, Nes; Mohamed, Alizae Marny; Marizan Nor, Murshida; Ashar, Nor Atika

    2018-01-01

    The aim of the present study was to determine the overall reliability and validity of arch parameters measured digitally compared to conventional measurement. A sample of 111 plaster study models of Down syndrome (DS) patients were digitized using a blue light three-dimensional (3D) scanner. Digital and manual measurements of defined parameters were performed using Geomagic analysis software (Geomagic Studio 2014 software, 3D Systems, Rock Hill, SC, USA) on digital models and with a digital calliper (Tuten, Germany) on plaster study models. Both measurements were repeated twice to validate the intraexaminer reliability based on intraclass correlation coefficients (ICCs) using the independent t test and Pearson's correlation, respectively. The Bland-Altman method of analysis was used to evaluate the agreement of the measurement between the digital and plaster models. No statistically significant differences (p > 0.05) were found between the manual and digital methods when measuring the arch width, arch length, and space analysis. In addition, all parameters showed a significant correlation coefficient (r ≥ 0.972; p digital and manual measurements. Furthermore, a positive agreement between digital and manual measurements of the arch width (90-96%), arch length and space analysis (95-99%) were also distinguished using the Bland-Altman method. These results demonstrate that 3D blue light scanning and measurement software are able to precisely produce 3D digital model and measure arch width, arch length, and space analysis. The 3D digital model is valid to be used in various clinical applications.

  19. Method to make accurate concentration and isotopic measurements for small gas samples

    Science.gov (United States)

    Palmer, M. R.; Wahl, E.; Cunningham, K. L.

    2013-12-01

    Carbon isotopic ratio measurements of CO2 and CH4 provide valuable insight into carbon cycle processes. However, many of these studies, like soil gas, soil flux, and water head space experiments, provide very small gas sample volumes, too small for direct measurement by current constant-flow Cavity Ring-Down (CRDS) isotopic analyzers. Previously, we addressed this issue by developing a sample introduction module which enabled the isotopic ratio measurement of 40ml samples or smaller. However, the system, called the Small Sample Isotope Module (SSIM), does dilute the sample during the delivery with inert carrier gas which causes a ~5% reduction in concentration. The isotopic ratio measurements are not affected by this small dilution, but researchers are naturally interested accurate concentration measurements. We present the accuracy and precision of a new method of using this delivery module which we call 'double injection.' Two portions of the 40ml of the sample (20ml each) are introduced to the analyzer, the first injection of which flushes out the diluting gas and the second injection is measured. The accuracy of this new method is demonstrated by comparing the concentration and isotopic ratio measurements for a gas sampled directly and that same gas measured through the SSIM. The data show that the CO2 concentration measurements were the same within instrument precision. The isotopic ratio precision (1σ) of repeated measurements was 0.16 permil for CO2 and 1.15 permil for CH4 at ambient concentrations. This new method provides a significant enhancement in the information provided by small samples.

  20. Measuring method of liquid flow behavior using visualization

    International Nuclear Information System (INIS)

    Serizawa, Akimi; Kamei, Takashi; Takahashi, Osamu; Kawara, Zensaku

    1994-01-01

    It is important for the safety of nuclear reactor to understand the behavior of gas-liquid two-phase flow. For that analysis, we have to understand its time and spatial dependence. But most of the measuring methods applied to two-phase flow experiments are not enough for this purpose, because they consider the time averaged value, and they are put on the local position in test sections. Standing on such a point of view, we have been developing a measuring method using fluorescence. And from those pictures gotten by video camera, after processed by computer, we measure liquid film thickness. (author)