WorldWideScience

Sample records for repeated measure design

  1. 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.

  2. 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.

  3. On the repeated measures designs and sample sizes for randomized controlled trials.

    Science.gov (United States)

    Tango, Toshiro

    2016-04-01

    For the analysis of longitudinal or repeated measures data, generalized linear mixed-effects models provide a flexible and powerful tool to deal with heterogeneity among subject response profiles. However, the typical statistical design adopted in usual randomized controlled trials is an analysis of covariance type analysis using a pre-defined pair of "pre-post" data, in which pre-(baseline) data are used as a covariate for adjustment together with other covariates. Then, the major design issue is to calculate the sample size or the number of subjects allocated to each treatment group. In this paper, we propose a new repeated measures design and sample size calculations combined with generalized linear mixed-effects models that depend not only on the number of subjects but on the number of repeated measures before and after randomization per subject used for the analysis. The main advantages of the proposed design combined with the generalized linear mixed-effects models are (1) it can easily handle missing data by applying the likelihood-based ignorable analyses under the missing at random assumption and (2) it may lead to a reduction in sample size, compared with the simple pre-post design. The proposed designs and the sample size calculations are illustrated with real data arising from randomized controlled trials.

  4. Status of a UAV SAR Designed for Repeat Pass Interferometry for Deformation Measurements

    Science.gov (United States)

    Hensley, Scott; Wheeler, Kevin; Hoffman, Jim; Miller, Tim; Lou, Yunling; Muellerschoen, Ron; Zebker, Howard; Madsen, Soren; Rosen, Paul

    2004-01-01

    Under the NASA ESTO sponsored Instrument Incubator Program we have designed a lightweight, reconfigurable polarimetric L-band SAR designed for repeat pass deformation measurements of rapidly deforming surfaces of geophysical interest such as volcanoes or earthquakes. This radar will be installed on an unmanned airborne vehicle (UAV) or a lightweight, high-altitude, and long endurance platform such as the Proteus. After a study of suitable available platforms we selected the Proteus for initial development and testing of the system. We want to control the repeat track capability of the aircraft to be within a 10 m tube to support the repeat deformation capability. We conducted tests with the Proteus using real-time GPS with sub-meter accuracy to see if pilots could fly the aircraft within the desired tube. Our results show that pilots are unable to fly the aircraft with the desired accuracy and therefore an augmented autopilot will be required to meet these objectives. Based on the Proteus flying altitude of 13.7 km (45,000 ft), we are designing a fully polarimetric L-band radar with 80 MHz bandwidth and 16 km range swath. This radar will have an active electronic beam steering antenna to achieve Doppler centroid stability that is necessary for repeat-pass interferometry (RPI). This paper will present are design criteria, current design and expected science applications.

  5. Multiple-objective response-adaptive repeated measurement designs in clinical trials for binary responses.

    Science.gov (United States)

    Liang, Yuanyuan; Li, Yin; Wang, Jing; Carriere, Keumhee C

    2014-02-20

    A multiple-objective allocation strategy was recently proposed for constructing response-adaptive repeated measurement designs for continuous responses. We extend the allocation strategy to constructing response-adaptive repeated measurement designs for binary responses. The approach with binary responses is quite different from the continuous case, as the information matrix is a function of responses, and it involves nonlinear modeling. To deal with these problems, we first build the design on the basis of success probabilities. Then we illustrate how various models can accommodate carryover effects on the basis of logits of response profiles as well as any correlation structure. Through computer simulations, we find that the allocation strategy developed for continuous responses also works well for binary responses. As expected, design efficiency in terms of mean squared error drops sharply, as more emphasis is placed on increasing treatment benefit than estimation precision. However, we find that it can successfully allocate more patients to better treatment sequences without sacrificing much estimation precision.

  6. On the Analysis of a Repeated Measure Design in Genome-Wide Association Analysis

    Directory of Open Access Journals (Sweden)

    Young Lee

    2014-11-01

    Full Text Available Longitudinal data enables detecting the effect of aging/time, and as a repeated measures design is statistically more efficient compared to cross-sectional data if the correlations between repeated measurements are not large. In particular, when genotyping cost is more expensive than phenotyping cost, the collection of longitudinal data can be an efficient strategy for genetic association analysis. However, in spite of these advantages, genome-wide association studies (GWAS with longitudinal data have rarely been analyzed taking this into account. In this report, we calculate the required sample size to achieve 80% power at the genome-wide significance level for both longitudinal and cross-sectional data, and compare their statistical efficiency. Furthermore, we analyzed the GWAS of eight phenotypes with three observations on each individual in the Korean Association Resource (KARE. A linear mixed model allowing for the correlations between observations for each individual was applied to analyze the longitudinal data, and linear regression was used to analyze the first observation on each individual as cross-sectional data. We found 12 novel genome-wide significant disease susceptibility loci that were then confirmed in the Health Examination cohort, as well as some significant interactions between age/sex and SNPs.

  7. Status of a UAVSAR designed for repeat pass interferometry for deformation measurements

    Science.gov (United States)

    Hensley, Scott; Wheeler, Kevin; Sadowy, Greg; Miller, Tim; Shaffer, Scott; Muellerschoen, Ron; Jones, Cathleen; Zebker, Howard; Madsen, Soren; Paul, Rose

    2005-01-01

    NASA's Jet Propulsion Laboratory is currently implementing a reconfigurable polarimetric L-band synthetic aperture radar (SAR), specifically designed to acquire airborne repeat track interferometric (RTI) SAR data, also known as differential interferometric measurements. Differential interferometry can provide key deformation measurements, important for the scientific studies of Earthquakes and volcanoes. Using precision real-time GPS and a sensor controlled flight management system, the system will be able to fly predefined paths with great precision. The expected performance of the flight control system will constrain the flight path to be within a 10 m diameter tube about the desired flight track. The radar wilI be designed to operate on a UAV (Unpiloted Aria1 Vehicle) but will initially be demonstrated on a minimally piloted vehicle (MPV), such as the Proteus buitt by Scaled Composites or on a NASA Gulfstream III. The radar design is a fully polarimetric with an 80 MHz bandwidth (2 m range resolution) and 16 km range swath. The antenna is an electronically steered along track to assure that the actual antenna pointing can be controlled independent of the wind direction and speed. Other features supported by the antenna include an elevation monopulse option and a pulse-to-pulse resteering capability that will enable some novel modes of operation. The system will nominally operate at 45,000 ft (13800 m). The program began out as an Instrument Incubator Project (IIP) funded by NASA Earth Science and Technology Office (ESTO).

  8. 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....... Our study suggests that the blood transcriptome of healthy individuals is reproducible over a time period of several months. © 2013 Elsevier Inc....

  9. Splashing Our Way to Playfulness! An Aquatic Playgroup for Young Children with Autism, A Repeated Measures Design

    Science.gov (United States)

    Fabrizi, Sarah E.

    2015-01-01

    This study investigated the effectiveness of an aquatic playgroup on the playfulness of children, ages 2 to 3 with autism spectrum disorder. Using a repeated measures design, we followed 10 children and their caregivers who participated in a 6-week aquatic playgroup in southwest Florida. Four dyads completed the entire 12-week study period. The…

  10. Splashing Our Way to Playfulness! An Aquatic Playgroup for Young Children with Autism, A Repeated Measures Design

    Science.gov (United States)

    Fabrizi, Sarah E.

    2015-01-01

    This study investigated the effectiveness of an aquatic playgroup on the playfulness of children, ages 2 to 3 with autism spectrum disorder. Using a repeated measures design, we followed 10 children and their caregivers who participated in a 6-week aquatic playgroup in southwest Florida. Four dyads completed the entire 12-week study period. The…

  11. A Correction for the Epsilon Approximate Test in Repeated Measures Designs with Two or More Independent Groups.

    Science.gov (United States)

    Lecoutre, Bruno

    1991-01-01

    The routine epsilon approximate test in repeated measures designs when the condition of circularity is unfulfilled uses an erroneous formula in the case of two or more groups. Because this may lead to underestimation of the deviation from circularity when the subject number is small, a correction is proposed. (Author/SLD)

  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. A novel AX+/BX- paradigm to assess fear learning and safety-signal processing with repeated-measure designs.

    Science.gov (United States)

    Kazama, Andy M; Schauder, Kimberly B; McKinnon, Michael; Bachevalier, Jocelyne; Davis, Michael

    2013-04-15

    One of the core symptoms of anxiety disorders, such as post-traumatic stress disorder, is the failure to overcome feelings of danger despite being in a safe environment. This deficit likely stems from an inability to fully process safety signals, which are cues in the environment that enable healthy individuals to over-ride fear in aversive situations. Studies examining safety signal learning in rodents, humans, and non-human primates currently rely on between-groups designs. Because repeated-measure designs reduce the number of subjects required, and facilitate a broader range of safety signal studies, the current project sought to develop a repeated-measures safety-signal learning paradigm in non-human primates. Twelve healthy rhesus macaques of both sexes received three rounds of auditory fear-potentiated startle training and testing using an AX+/BX- design with all visual cues. Cue AX was paired with an aversive blast of air, whereas the same X cue in compound with another B cue (BX) signaled the absence of an air blast. Hence, cue B served as a safety signal. Once animals consistently discriminated between the aversive (AX+) and safe (BX-) cues, measured by greater startle amplitude in the presence of AX vs. BX, they were tested for conditioned inhibition by eliciting startle in the presence of a novel ambiguous combined cue (AB). Similar to previous AX+/BX- studies, healthy animals rapidly learned to discriminate between the AX+ and BX- cues as well as demonstrate conditioned inhibition in the presence of the combined AB cue (i.e. lower startle amplitude in the presence of AB vs. AX). Additionally, animals performed consistently across three rounds of testing using three new cues each time. The results validate this novel method that will serve as a useful tool for better understanding the mechanisms for the regulation of fear and anxiety. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. 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...

  15. Measurement-based quantum repeaters

    CERN Document Server

    Zwerger, M; Briegel, H J

    2012-01-01

    We introduce measurement-based quantum repeaters, where small-scale measurement-based quantum processors are used to perform entanglement purification and entanglement swapping in a long-range quantum communication protocol. In the scheme, pre-prepared entangled states stored at intermediate repeater stations are coupled with incoming photons by simple Bell-measurements, without the need of performing additional quantum gates or measurements. We show how to construct the required resource states, and how to minimize their size. We analyze the performance of the scheme under noise and imperfections, with focus on small-scale implementations involving entangled states of few qubits. We find measurement-based purification protocols with significantly improved noise thresholds. Furthermore we show that already resource states of small size suffice to significantly increase the maximal communication distance. We also discuss possible advantages of our scheme for different set-ups.

  16. Repeated measures dose-finding design with time-trend detection in the presence of correlated toxicity data.

    Science.gov (United States)

    Yin, Jun; Paoletti, Xavier; Sargent, Daniel J; Mandrekar, Sumithra J

    2017-08-01

    Phase I trials are designed to determine the safety, tolerability, and recommended phase 2 dose of therapeutic agents for subsequent testing. The dose-finding paradigm has thus traditionally focused on identifying the maximum tolerable dose of an agent or combination therapy under the assumption that there is a non-decreasing relationship between dose-toxicity and dose-efficacy. The dose is typically determined based on the probability of severe toxicity observed during the first treatment cycle. A novel endpoint, the total toxicity profile, was previously developed to account for the multiple toxicity types and grades experienced in the first cycle. More recently, this was extended to a repeated measures design based on the total toxicity profile to account for longitudinal toxicities over multiple treatment cycles in the absence of within-patient correlation. In this work, we propose to extend the design in the presence of within-patient correlation. Furthermore, we provide a framework to detect a toxicity time trend (toxicity increasing, decreasing, or stable) over multiple treatment cycles. We utilize a linear mixed model in the Bayesian framework, with the addition of Bayesian risk functions for decision-making in dose assignment. The performance of this design was evaluated using simulation studies and real data from a phase I trial. We demonstrated that using available toxicity data from all cycles of treatment improves the accuracy of maximum tolerated dose identification and allows for the detection of a time trend. The performance is consistent regardless of the strength of the within-patient correlation. In addition, the use of a quasi-continuous total toxicity profile score significantly increased the power to detect time trends compared to when binary data only were used. The increased interest in molecularly targeted agents and immunotherapies in oncology necessitates innovative phase I study designs. Our proposed framework provides a tool to tackle

  17. Power and sample size for the S:T repeated measures design combined with a linear mixed-effects model allowing for missing data.

    Science.gov (United States)

    Tango, Toshiro

    2017-02-13

    Tango (Biostatistics 2016) proposed a new repeated measures design called the S:T repeated measures design, combined with generalized linear mixed-effects models and sample size calculations for a test of the average treatment effect that depend not only on the number of subjects but on the number of repeated measures before and after randomization per subject used for analysis. The main advantages of the proposed design combined with the generalized linear mixed-effects models are (1) it can easily handle missing data by applying the likelihood-based ignorable analyses under the missing at random assumption and (2) it may lead to a reduction in sample size compared with the simple pre-post design. In this article, we present formulas for calculating power and sample sizes for a test of the average treatment effect allowing for missing data within the framework of the S:T repeated measures design with a continuous response variable combined with a linear mixed-effects model. Examples are provided to illustrate the use of these formulas.

  18. 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.

  19. 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.

  20. Applying the General Linear Model to Repeated Measures Problems.

    Science.gov (United States)

    Pohlmann, John T.; McShane, Michael G.

    The purpose of this paper is to demonstrate the use of the general linear model (GLM) in problems with repeated measures on a dependent variable. Such problems include pretest-posttest designs, multitrial designs, and groups by trials designs. For each of these designs, a GLM analysis is demonstrated wherein full models are formed and restrictions…

  1. Discriminant analysis for repeated measures data: a review

    Directory of Open Access Journals (Sweden)

    Lisa Lix

    2010-09-01

    Full Text Available Discriminant analysis (DA encompasses procedures for classifying observations into groups (i.e., predictive discriminative analysis and describing the relative importance of variables for distinguishing amongst groups (i.e., descriptive discriminative analysis. In recent years, a number of developments have occurred in DA procedures for the analysis of data from repeated measures designs. Specifically, DA procedures have been developed for repeated measures data characterized by missing observations and/or unbalanced measurement occasions, as well as high-dimensional data in which measurements are collected repeatedly on two or more variables. This paper reviews the literature on DA procedures for univariate and multivariate repeated measures data, focusing on covariance pattern and linear mixed-effects models. A numeric example illustrates their implementation using SAS software.

  2. 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...

  3. Repeated measurement sampling in genetic association analysis with genotyping errors.

    Science.gov (United States)

    Lai, Renzhen; Zhang, Hong; Yang, Yaning

    2007-02-01

    Genotype misclassification occurs frequently in human genetic association studies. When cases and controls are subject to the same misclassification model, Pearson's chi-square test has the correct type I error but may lose power. Most current methods adjusting for genotyping errors assume that the misclassification model is known a priori or can be assessed by a gold standard instrument. But in practical applications, the misclassification probabilities may not be completely known or the gold standard method can be too costly to be available. The repeated measurement design provides an alternative approach for identifying misclassification probabilities. With this design, a proportion of the subjects are measured repeatedly (five or more repeats) for the genotypes when the error model is completely unknown. We investigate the applications of the repeated measurement method in genetic association analysis. Cost-effectiveness study shows that if the phenotyping-to-genotyping cost ratio or the misclassification rates are relatively large, the repeat sampling can gain power over the regular case-control design. We also show that the power gain is not sensitive to the genetic model, genetic relative risk and the population high-risk allele frequency, all of which are typically important ingredients in association studies. An important implication of this result is that whatever the genetic factors are, the repeated measurement method can be applied if the genotyping errors must be accounted for or the phenotyping cost is high.

  4. Modeling repeated measurement data for occupational exposure assessment and epidemiology

    NARCIS (Netherlands)

    Peretz, Chava

    2004-01-01

    Repeated measurements designs, occur frequently in the assessment of exposure to toxic chemicals. This thesis deals with the possibilities of using mixed effects models for occupational exposure assessment and in the analysis of exposure response relationships. The model enables simultaneous estima

  5. 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.

  6. Capturing learning effects on eye movements in repeated measures experiments

    DEFF Research Database (Denmark)

    Bagger, Martin; Orquin, Jacob Lund; Fiedler, Susann

    We propose and illustrate that repeated exposure to stimuli sets increases the size of the saccade amplitudes. Saccadic amplitudes are closely related to the perceptual span and therefore used as a measure for the information intake in an experiment. Studies on expertise have shown that experts...... experiment in which 68 participants made choices between four alternatives with three different between subject conditions varying in presentation format (verbal matrix, a pictorial matrix, and a realistic product representation). The results consistently demonstrate an increase of the saccade amplitude over...... the course of the experiment independent of condition. We conclude by discussing our results in the light of the possible increase of the perceptual span and its implications for the research procedure in eye-tracking experiments with a repeated measurement design....

  7. 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.

  8. Bayesian model selection of informative hypotheses for repeated measurements

    NARCIS (Netherlands)

    Mulder, Joris; Klugkist, I.G.; Schoot, Rens van de; Meeus, W.H.J.; Selfhout, Maarten; Hoijtink, Herbert

    2010-01-01

    When analyzing repeated measurements data, researchers often have expectations about the relations between the measurement means. The expectations can often be formalized using equality and inequality constraints between (i) the measurement means over time, (ii) the measurement means between

  9. Bayesian model selection of informative hypotheses for repeated measurements

    NARCIS (Netherlands)

    Mulder, J.|info:eu-repo/dai/nl/304823031; Klugkist, I.G.|info:eu-repo/dai/nl/27330089X; Van de Schoot, R.|info:eu-repo/dai/nl/304833207; Meeus, W.H.J.|info:eu-repo/dai/nl/070442215; van Zalk, M.H.W.|info:eu-repo/dai/nl/304836214; Hoijtink, H.J.A.|info:eu-repo/dai/nl/075184427

    2009-01-01

    When analyzing repeated measurements data, researchers often have expectations about the relations between the measurement means. The expectations can often be formalized using equality and inequality constraints between (i) the measurement means over time, (ii) the measurement means between groups,

  10. Artificial leucine rich repeats as new scaffolds for protein design.

    Science.gov (United States)

    Baabur-Cohen, Hemda; Dayalan, Subashini; Shumacher, Inbal; Cohen-Luria, Rivka; Ashkenasy, Gonen

    2011-04-15

    The leucine rich repeat (LRR) motif that participates in many biomolecular recognition events in cells was suggested as a general scaffold for producing artificial receptors. We describe here the design and first total chemical synthesis of small LRR proteins, and their structural analysis. When evaluating the tertiary structure as a function of different number of repeating units (1-3), we were able to find that the 3-repeats sequence, containing 90 amino acids, folds into the expected structure.

  11. [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.

  12. Exploring the repeat protein universe through computational protein design.

    Science.gov (United States)

    Brunette, T J; Parmeggiani, Fabio; Huang, Po-Ssu; Bhabha, Gira; Ekiert, Damian C; Tsutakawa, Susan E; Hura, Greg L; Tainer, John A; Baker, David

    2015-12-24

    A central question in protein evolution is the extent to which naturally occurring proteins sample the space of folded structures accessible to the polypeptide chain. Repeat proteins composed of multiple tandem copies of a modular structure unit are widespread in nature and have critical roles in molecular recognition, signalling, and other essential biological processes. Naturally occurring repeat proteins have been re-engineered for molecular recognition and modular scaffolding applications. Here we use computational protein design to investigate the space of folded structures that can be generated by tandem repeating a simple helix-loop-helix-loop structural motif. Eighty-three designs with sequences unrelated to known repeat proteins were experimentally characterized. Of these, 53 are monomeric and stable at 95 °C, and 43 have solution X-ray scattering spectra consistent with the design models. Crystal structures of 15 designs spanning a broad range of curvatures are in close agreement with the design models with root mean square deviations ranging from 0.7 to 2.5 Å. Our results show that existing repeat proteins occupy only a small fraction of the possible repeat protein sequence and structure space and that it is possible to design novel repeat proteins with precisely specified geometries, opening up a wide array of new possibilities for biomolecular engineering.

  13. Analysis of repeated outcome measures from longitudinal studies

    Institute of Scientific and Technical Information of China (English)

    Yuanjia WANG; Naihua DUAN

    2011-01-01

    @@ In many clinical studies repeated measurements of an outcome are collected over time.For example,in an 8-week study of treatment for obsessive compulsive disorder,the severity of the disorder may be measured weekly using the Yale-Brown-Obsessive-Compulsive-Disorder-Scale (YBOCS).For each study participant who completes the study,there will be nine repeated measures of YBOCS (a baseline assessment plus eight assessments during the course of treatment).Such a study in which participants are followed and measured repeatedly over time is called a longitudinal study and the resulting data are called longitudinal data.

  14. Airborne Repeat Pass Interferometry for Deformation Measurements

    NARCIS (Netherlands)

    Groot, J.; Otten, M.; Halsema, E. van

    2000-01-01

    In ground engineering the need for deformation measurements is urgent. SAR interferometry can be used to measure small (sub-wavelength) deformations. An experiment to investigate this for dike deformations was set up, using the C-band SAR system PHARUS (PHased ARray Universal SAR). This paper descri

  15. 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...

  16. Correct use of repeated measures analysis of variance.

    Science.gov (United States)

    Park, Eunsik; Cho, Meehye; Ki, Chang-Seok

    2009-02-01

    In biomedical research, researchers frequently use statistical procedures such as the t-test, standard analysis of variance (ANOVA), or the repeated measures ANOVA to compare means between the groups of interest. There are frequently some misuses in applying these procedures since the conditions of the experiments or statistical assumptions necessary to apply these procedures are not fully taken into consideration. In this paper, we demonstrate the correct use of repeated measures ANOVA to prevent or minimize ethical or scientific problems due to its misuse. We also describe the appropriate use of multiple comparison tests for follow-up analysis in repeated measures ANOVA. Finally, we demonstrate the use of repeated measures ANOVA by using real data and the statistical software package SPSS (SPSS Inc., USA).

  17. Assessing agreement with repeated measures for random observers.

    Science.gov (United States)

    Chen, Chia-Cheng; Barnhart, Huiman X

    2011-12-30

    Agreement studies are often concerned with assessing whether different observers for measuring responses on the same subject or sample can produce similar results. The concordance correlation coefficient (CCC) is a popular index for assessing the closeness among observers for quantitative measurements. Usually, the CCC is used for data without and with replications based on subject and observer effects only. However, we cannot use this methodology if repeated measurements rather than replications are collected. Although there exist some CCC-type indices for assessing agreement with repeated measurements, there is no CCC for random observers and random time points. In this paper, we propose a new CCC for repeated measures where both observers and time points are treated as random effects. A simulation study demonstrates our proposed methodology, and we use vertebral body data and image data for illustrations.

  18. Design and analysis of communication protocols for quantum repeater networks

    Science.gov (United States)

    Jones, Cody; Kim, Danny; Rakher, Matthew T.; Kwiat, Paul G.; Ladd, Thaddeus D.

    2016-08-01

    We analyze how the performance of a quantum-repeater network depends on the protocol employed to distribute entanglement, and we find that the choice of repeater-to-repeater link protocol has a profound impact on entanglement-distribution rate as a function of hardware parameters. We develop numerical simulations of quantum networks using different protocols, where the repeater hardware is modeled in terms of key performance parameters, such as photon generation rate and collection efficiency. These parameters are motivated by recent experimental demonstrations in quantum dots, trapped ions, and nitrogen-vacancy centers in diamond. We find that a quantum-dot repeater with the newest protocol (‘MidpointSource’) delivers the highest entanglement-distribution rate for typical cases where there is low probability of establishing entanglement per transmission, and in some cases the rate is orders of magnitude higher than other schemes. Our simulation tools can be used to evaluate communication protocols as part of designing a large-scale quantum network.

  19. Measurement and repeatability of interrupter resistance in unsedated newborn infants.

    Science.gov (United States)

    Adams, A M; Olden, C; Wertheim, D; Ives, A; Bridge, P D; Lenton, J; Seddon, P

    2009-12-01

    Interrupter resistance (R(int)) is a useful measure of airway caliber in young children, but has not been well characterized in infants-in whom there are concerns about the accurate measurement of driving pressure. This study aimed to assess the feasibility and repeatability of measuring R(int) in unsedated newborn infants, and to explore alternative algorithms for calculating driving pressure. R(int) measurement was attempted in 28 healthy term newborn infants during natural sleep using the MicroRint device. Paired R(int) measurements were achieved in 24 infants, but after screening of waveforms only 15 infants had at least 5 technically acceptable waveforms on both measurements. R(int) values obtained were comparable with reported values for airflow resistance in newborns using other methods. However, the repeatability coefficient (CR) was much higher than reported values in preschool children using standard back-extrapolation algorithms, with CR 2.47 KPa L(-1) sec (unscreened) and 2.93 KPa L(-1) sec (screened). Other algorithms gave only marginally better repeatability, with all CR values over 50% of the mean R(int) value. Using current commercially available equipment, R(int) is too poorly repeatable to be a reliable measurement of airflow resistance in newborn infants. Lower deadspace equipment is needed, but anatomical and physiological factors in the infant are also important.

  20. Rank-Based Analysis of Unbalanced Repeated Measures Data

    Directory of Open Access Journals (Sweden)

    M. Mushfiqur Rashid

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} In this article, we have developed a rank (intra-subject based analysis of clinical trials with unbalanced repeated measures data. We assume that the errors within each patient are exchangeable and continuous random variables. This rank-based inference is valid when the unbalanced data are missing either completely at random or by design. A drop in dispersion test is developed for general linear hypotheses. A numerical example is given to illustrate the procedure.

  1. Positional Repeatability Measurements Of Stepper Motors At Cryogenic Temperatures

    Science.gov (United States)

    Pompea, Stephen M.; Hall, Michael S.; Bartko, Frank; Houck, James R.

    1983-08-01

    Stepper motors operating at liquid helium temperature have multiple applications in cryogenically-cooled telescopes such as the Shuttle Infrared Telescope Facility (SIRTF). These SIRTF applications include driving cryogen flow valves, operating the Multiple Instrument Chamber (MIC) beam splitter mechanism, and operating filters and grating wheel mechanisms in the scientific instruments. The positional repeatability of the beam splitter drive mechanism is especially critical since it feeds the optical beam to the scien-tific instruments. Despite these important applications, no significant data on the positional repeatability of stepper motors at cryogenic temperatures has been available. Therefore, we conducted a series of measurements to determine the positional repeatability of a modified, off-the-shelf Berger/Lahr stepper motor (model RDM 253/25, step angle 3.6°) which had demonstrated excellent performance in previous endurance testing at LHe temperature. These test results indicated that the positional repeatability of the motor was excellent at all temperatures, with somewhat better performance at cryogenic temperatures. Another important result was that the motor could be repeatedly turned off and on while still accurately retaining its rotor position.

  2. Repeatability of OCT lens thickness measures with age and accommodation.

    Science.gov (United States)

    Doyle, Lesley; Little, Julie-Anne; Saunders, Kathryn J

    2013-12-01

    To investigate crystalline lens thickness (LT) across a range of ages and accommodative demands and to evaluate the repeatability of LT measurements using the Visante Anterior Segment Optical Coherence Tomographer (AS-OCT) (Zeiss Meditec, Germany) under non-cycloplegic conditions. Participants were 98 visually normal adults aged 18-75 years, stratified into age groups of 18-29, 30-39, 40-49, 50-59, and 60-75 years of age. Images of the crystalline lens were taken using the Visante AS-OCT during stimulation of accommodation at demands of 0, 1, 2, 3, 4, 5, and 8 D with accommodative response measured in a subgroup of participants. Images were analyzed and LT measured assuming a refractive index of 1.42. Repeat measures were taken from 86 participants for each accommodative demand at a second visit. The mean unaccommodated LT for all participants was 4.07 ± 0.40 mm. An average increase in LT of 20 μm per year was calculated (linear regression, R² = 0.61, F(1,89) = 143.92, p report the repeatability of LT measures using the Visante AS-OCT in the non-cyclopleged eye. It has also demonstrated the ability of the Visante AS-OCT to detect small changes in lens thickness with accommodation.

  3. 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.

  4. Hierarchical linear model: thinking outside the traditional repeated-measures analysis-of-variance box.

    Science.gov (United States)

    Lininger, Monica; Spybrook, Jessaca; Cheatham, Christopher C

    2015-04-01

    Longitudinal designs are common in the field of athletic training. For example, in the Journal of Athletic Training from 2005 through 2010, authors of 52 of the 218 original research articles used longitudinal designs. In 50 of the 52 studies, a repeated-measures analysis of variance was used to analyze the data. A possible alternative to this approach is the hierarchical linear model, which has been readily accepted in other medical fields. In this short report, we demonstrate the use of the hierarchical linear model for analyzing data from a longitudinal study in athletic training. We discuss the relevant hypotheses, model assumptions, analysis procedures, and output from the HLM 7.0 software. We also examine the advantages and disadvantages of using the hierarchical linear model with repeated measures and repeated-measures analysis of variance for longitudinal data.

  5. Hierarchical Linear Model: Thinking Outside the Traditional Repeated-Measures Analysis-of-Variance Box

    Science.gov (United States)

    Lininger, Monica; Spybrook, Jessaca; Cheatham, Christopher C.

    2015-01-01

    Longitudinal designs are common in the field of athletic training. For example, in the Journal of Athletic Training from 2005 through 2010, authors of 52 of the 218 original research articles used longitudinal designs. In 50 of the 52 studies, a repeated-measures analysis of variance was used to analyze the data. A possible alternative to this approach is the hierarchical linear model, which has been readily accepted in other medical fields. In this short report, we demonstrate the use of the hierarchical linear model for analyzing data from a longitudinal study in athletic training. We discuss the relevant hypotheses, model assumptions, analysis procedures, and output from the HLM 7.0 software. We also examine the advantages and disadvantages of using the hierarchical linear model with repeated measures and repeated-measures analysis of variance for longitudinal data. PMID:25875072

  6. 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

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

    CERN Document Server

    Altamirano, Natacha; Mann, Robert B; Zych, Magdalena

    2016-01-01

    Motivated by the recent efforts to describe the gravitational interaction as a classical channel arising from continuous quantum measurements, 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 (quantum Zeno effect). 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, generalizing the lower bound of the gravitational example. However, by allowing multipartite measurements, the interactions can be induced with arbitrary low decoherence. Our results have implications for gravity-inspired decoherence models and the simple framework used in the present study can find applications in devising novel quantum control protocols, or quan...

  8. Association between CAG repeat polymorphisms and the risk of prostate cancer: a meta-analysis by race, study design and the number of (CAG)n repeat polymorphisms.

    Science.gov (United States)

    Sun, Jun-Hyun; Lee, Sang-Ah

    2013-11-01

    Although a number of studies have been conducted on the association between prostate cancer and CAG repeat polymorphisms of the androgen receptor gene, this association remains elusive and controversial. In this meta-analysis, we aimed to evaluate the effects of (CAG)n repeat genetic polymorphisms on the incidence of prostate cancer, particularly as regards race, study design and the number of (CAG)n repeats. To collect articles published on the association between CAG repeats and prostate cancer, publications were identified from the National Center for Biotechnology Information (NCBI) database of epidemiological studies published up to October 2011; our identification of publications was not limited by a language barrier. The following search keywords were used: prostate cancer risk, CAG repeat polymorphism, androgen receptor gene and human. Stata version 10 was used for the meta-analysis and the publication bias was measured through the Begg's test and Egger's test. This meta-analysis included 47 studies with 13,346 cases and 15,172 control or non-cases and consisted of 31 reports based on Caucasians, ten on Asians, one on Hispanics and four on combined ethnic groups. The carriers of a shorter CAG repeat sequence had an increased risk of prostate cancer (OR 1.21, 95% CI 1.10-1.34 for all subjects; OR 1.21, 95% CI 1.10-1.34 for prospective studies; OR 1.32, 95% CI 1.15-1.51 for retrospective studies) regardless of the exact length of the CAG repeat, compared with carriers of a longer repeat sequence. In terms of race, the risk of carrying a shorter CAG repeat sequence was 1.10- and 1.83-fold higher than that of a longer repeat sequence in Caucasians and Asians, respectively. For the specific number of CAG repeat polymorphisms, carriers of repeats were observed to have a higher risk of prostate cancer (OR 1.16, 95% CI 1.04-1.29) compared with carriers with ≥ 22 CAG repeat polymorphisms, particularly for Asians (OR 2.06, 95% CI 1.00-4.24). This meta

  9. Repeated High-Precision Gravity and GPS Measurement Techniques

    Science.gov (United States)

    Gettings, P.; Harris, R. N.; Allis, R.; Chapman, D. S.

    2003-12-01

    Repeated high-precision gravity and GPS measurements are becoming a common tool for tracking changes in subsurface reservoirs. Despite this, there is little literature which discusses measurement techniques and the expected errors. Our research has focused on improving measurement techniques to be applied to ground water and geothermal steam reservoirs, including quantifying the minimum error levels with modern equipment. We applied these methods in two studies: ground water monitoring of the southern Salt Lake valley, Utah, USA, and steam monitoring of The Geysers geothermal field, California, USA. Gravity measurements using modern relative high-precision meters, such as Scintrex CG-3Ms or L&R E series, can now be routinely made to an accuracy of 5 μ Gal. Such accuracy requires the use of time series analysis at each station, and non-linear instrument drift functions. Modern computerized meters are capable of internally storing a time series of measurements for each station; older meters can often be fitted to log such data to a field computer. This time series, typically of 10-15 minute duration in our work, can then be analyzed in several ways to produce stable estimates of the gravity reading. In particular, our research has emphasized using a weighted arithmetic average (for long occupations), or a Thiele extrapolation scheme (for shorter station occupations). Instrument drift is removed through a superposition of a linear long-term drift function, and an empirical staircase function formed from differences between repeated station occupations. To achieve high-accuracy GPS measurements while maximizing the number of field stations in a survey, rapid-static measurements are necessary. We have tested the effect of occupation time and processing schemes on the absolute accuracy of the resulting GPS position. Using a post-processing differential method with a fixed (but not necessarily continuous) base station within 15 km, positioning error of <4 cm vertical is

  10. Quasar Variability Measurements With SDSS Repeated Imaging and POSS Data

    CERN Document Server

    Ivezic, Z; Juric, M; Anderson, S; Hall, P B; Richards, G T; Rockosi, C M; Vanden Berk, Daniel E; Turner, E L; Knapp, G R; Gunn, J E; Schlegel, D J; Strauss, M A; Schneider, D P

    2004-01-01

    We analyze the properties of quasar variability using repeated SDSS imaging data in five UV-to-far red photometric bands, accurate to 0.02 mag, for 13,000 spectroscopically confirmed quasars. The observed time lags span the range from 3 hours to over 3 years, and constrain the quasar variability for rest-frame time lags of up to two years, and at rest-frame wavelengths from 1000 Ang. to 6000 Ang. We demonstrate that 66,000 SDSS measurements of magnitude differences can be described within the measurement noise by a simple function of only three free parameters. The addition of POSS data constrains the long-term behavior of quasar variability and provides evidence for a turn-over in the structure function. This turn-over indicates that the characteristic time scale for optical variability of quasars is of the order 1 year.

  11. Dispersion Measure Variation of Repeating Fast Radio Burst Sources

    Science.gov (United States)

    Yang, Yuan-Pei; Zhang, Bing

    2017-09-01

    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.

  12. Coseismic and postseismic velocity changes measured by repeating earthquakes

    Science.gov (United States)

    Schaff, David P.; Beroza, Gregory C.

    2004-10-01

    Repeating earthquakes that rupture approximately the same fault patch and have nearly identical waveforms are a useful tool for measuring temporal changes in wave propagation in the Earth's crust. Since source and path effects are common to all earthquakes in a repeating earthquake sequence (multiplet), differences in their waveforms can be attributed to changes in the characteristics of the medium. We have identified over 20 multiplets containing between 5 and 40 repeating events in the aftershock zones of the 1989 Loma Prieta and 1984 Morgan Hill, California, earthquakes. Postmain shock events reveal delays of phases in the early S wave coda of as much as 0.2 s relative to premain shock events. The delay amounts to a path-averaged coseismic velocity decrease of about 1.5% for P waves and 3.5% for S waves. Since most of the multiplets are aftershocks and follow Omori's law, we have excellent temporal sampling in the immediate postmain shock period. We find that the amplitude of the velocity decrease decays logarithmically in time following the main shock. In some cases it returns to the premain shock values, while in others it does not. Similar results are obtained for the Morgan Hill main shock. Because the fractional change in S wave velocity is greater than the fractional change in P wave velocity, it suggests that the opening or connection of fluid-filled fractures is the underlying cause. The magnitude of the velocity change implies that low effective pressures are present in the source region of the velocity change. Our results suggest that the changes are predominantly near the stations and shallow, but we cannot exclude the possibility that changes occur at greater depth as well. If the variations are shallow, we may be detecting the lingering effects of nonlinearity during main shock strong ground motion. If the variations are deep, it suggests that pore pressures at seismogenic depths are high, which would likely play a key role in the earthquake process.

  13. Bayesian Concordance Correlation Coefficient with Application to Repeatedly Measured Data

    Directory of Open Access Journals (Sweden)

    Atanu BHATTACHARJEE

    2015-10-01

    Full Text Available Objective: In medical research, Lin's classical concordance correlation coefficient (CCC is frequently applied to evaluate the similarity of the measurements produced by different raters or methods on the same subjects. It is particularly useful for continuous data. The objective of this paper is to propose the Bayesian counterpart to compute CCC for continuous data. Material and Methods: A total of 33 patients of astrocytoma brain treated in the Department of Radiation Oncology at Malabar Cancer Centre is enrolled in this work. It is a continuous data of tumor volume and tumor size repeatedly measured during baseline pretreatment workup and post surgery follow-ups for all patients. The tumor volume and tumor size are measured separately by MRI and CT scan. The agreement of measurement between MRI and CT scan is calculated through CCC. The statistical inference is performed through Markov Chain Monte Carlo (MCMC technique. Results: Bayesian CCC is found suitable to get prominent evidence for test statistics to explore the relation between concordance measurements. The posterior mean estimates and 95% credible interval of CCC on tumor size and tumor volume are observed with 0.96(0.87,0.99 and 0.98(0.95,0.99 respectively. Conclusion: The Bayesian inference is adopted for development of the computational algorithm. The approach illustrated in this work provides the researchers an opportunity to find out the most appropriate model for specific data and apply CCC to fulfill the desired hypothesis.

  14. A Simple and Transparent Alternative to Repeated Measures ANOVA

    Directory of Open Access Journals (Sweden)

    James W. Grice

    2015-09-01

    Full Text Available Observation Oriented Modeling is a novel approach toward conceptualizing and analyzing data. Compared with traditional parametric statistics, Observation Oriented Modeling is more intuitive, relatively free of assumptions, and encourages researchers to stay close to their data. Rather than estimating abstract population parameters, the overarching goal of the analysis is to identify and explain distinct patterns within the observations. Selected data from a recent study by Craig et al. were analyzed using Observation Oriented Modeling; this analysis was contrasted with a traditional repeated measures ANOVA assessment. Various pitfalls in traditional parametric analyses were avoided when using Observation Oriented Modeling, including the presence of outliers and missing data. The differences between Observation Oriented Modeling and various parametric and nonparametric statistical methods were finally discussed.

  15. Matrix-based concordance correlation coefficient for repeated measures.

    Science.gov (United States)

    Hiriote, Sasiprapa; Chinchilli, Vernon M

    2011-09-01

    In many clinical studies, Lin's concordance correlation coefficient (CCC) is a common tool to assess the agreement of a continuous response measured by two raters or methods. However, the need for measures of agreement may arise for more complex situations, such as when the responses are measured on more than one occasion by each rater or method. In this work, we propose a new CCC in the presence of repeated measurements, called the matrix-based concordance correlation coefficient (MCCC) based on a matrix norm that possesses the properties needed to characterize the level of agreement between two p× 1 vectors of random variables. It can be shown that the MCCC reduces to Lin's CCC when p= 1. For inference, we propose an estimator for the MCCC based on U-statistics. Furthermore, we derive the asymptotic distribution of the estimator of the MCCC, which is proven to be normal. The simulation studies confirm that overall in terms of accuracy, precision, and coverage probability, the estimator of the MCCC works very well in general cases especially when n is greater than 40. Finally, we use real data from an Asthma Clinical Research Network (ACRN) study and the Penn State Young Women's Health Study for demonstration.

  16. [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.

  17. Global Design Analysis for Highly Repeatable Solid-state Klystron Modulators

    CERN Document Server

    Anthony, Dal Gobbo

    2015-01-01

    This paper presents an analysis of the repeatability issue in the electrical-to-radio frequency conversion chains using pulsed klystrons. The focus is on the power electronics used in klystron modulators. Repeatability definition is presented and simulation results allow deriving important conclusions regarding the voltage repeatability harmonic content versus power electronics design directions. The trade-off between klystron modulator and low level RF controls is a key point for optimizing the global system repeatability performance.

  18. 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.

  19. Antennas fundamentals, design, measurement

    CERN Document Server

    Long, Maurice

    2009-01-01

    This comprehensive revision (3rd Edition) is a senior undergraduate or first-year graduate level textbook on antenna fundamentals, design, performance analysis, and measurements. In addition to its use as a formal course textbook, the book's pragmatic style and emphasis on the fundamentals make it especially useful to engineering professionals who need to grasp the essence of the subject quickly but without being mired in unnecessary detail. This new edition was prepared for a first year graduate course at Southern Polytechnic State University in Georgia. It provides broad coverage of antenna

  20. 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.

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

    Science.gov (United States)

    Li, Hao; Wood, Constance L; Getchell, Thomas V; Getchell, Marilyn L; Stromberg, Arnold J

    2004-12-30

    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. 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 alpha-level (alphanew = 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 alphanew to control the family-wise error rate (FWER) for each gene examined. 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.

  2. Repeated loading of fine grained soils for pavement design

    OpenAIRE

    Loach, Simon C.

    1987-01-01

    The primary aim of this research was to investigate the behaviour of a clay subjected to a loading regime similar to that experienced by a road subgrade under traffic loading in Great Britain. The material used was Keuper Marl. The samples were anisotropically consolidated in a triaxial apparatus from a slurry which allowed careful control over the stress history and produced uniform samples. The samples were fully instrumented and the apparatus was capable of applying repeated axial and radi...

  3. Validity and repeatability of three in-shoe pressure measurement systems.

    Science.gov (United States)

    Price, Carina; Parker, Daniel; Nester, Christopher

    2016-05-01

    In-shoe pressure measurement devices are used in research and clinic to quantify plantar foot pressures. Various devices are available, differing in size, sensor number and type; therefore accuracy and repeatability. Three devices (Medilogic, Tekscan and Pedar) were examined in a 2 day×3 trial design, quantifying insole response to regional and whole insole loading. The whole insole protocol applied an even pressure (50-600kPa) to the insole surface for 0-30s in the Novel TruBlue™ device. The regional protocol utilised cylinders with contact surfaces of 3.14 and 15.9cm(2) to apply pressures of 50 and 200kPa. The validity (% difference and Root Mean Square Error: RMSE) and repeatability (Intra-Class Correlation Coefficient: ICC) of the applied pressures (whole insole) and contact area (regional) were outcome variables. Validity of the Pedar system was highest (RMSE 2.6kPa; difference 3.9%), with the Medilogic (RMSE 27.0kPa; difference 13.4%) and Tekscan (RMSE 27.0kPa; difference 5.9%) systems displaying reduced validity. The average and peak pressures demonstrated high between-day repeatability for all three systems and each insole size (ICC≥0.859). The regional contact area % difference ranged from -97 to +249%, but the ICC demonstrated medium to high between-day repeatability (ICC≥0.797). Due to the varying responses of the systems, the choice of an appropriate pressure measurement device must be based on the loading characteristics and the outcome variables sought. Medilogic and Tekscan were most effective between 200 and 300kPa; Pedar performed well across all pressures. Contact area was less precise, but relatively repeatable for all systems.

  4. Detecting tropical forest biomass dynamics from repeated airborne lidar measurements

    Directory of Open Access Journals (Sweden)

    V. Meyer

    2013-08-01

    census data, differences of approximately one year between the ground census and lidar measurements, and differences in sensor characteristics. Our results indicate that the 50 ha BCI plot lost a significant amount of biomass (−0.8 Mg ha−1 yr−1 ± 2.2(SD over the past decade (2000–2010. Over the entire island and during the same period, mean AGB change was 0.2 ± 2.4 Mg ha−1 yr−1 with old growth forests losing −0.7 Mg ha−1 yr−1 ± 2.2 (SD, and secondary forests gaining +1.8 Mg ha yr−1 ± 3.4 (SD biomass. Our analysis suggests that repeated lidar surveys, despite taking measurement with different sensors, can estimate biomass changes in old-growth tropical forests at landscape scales (>10 ha.

  5. 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

  6. CAD Method to Design Complex Dobby Weaves with Large Repeats

    Institute of Scientific and Technical Information of China (English)

    祝成炎

    2001-01-01

    The principle of a CAD method of converting the pre-designed figures in image form into complex dobby weaves with the appearances similar to the original figures is mainly introduced in this paper. A few designed weaves by the created CAD system are also given as examples of the practical application in the area of complex dobby weave designing.

  7. Rational design of alpha-helical tandem repeat proteins with closed architectures

    Science.gov (United States)

    Doyle, Lindsey; Hallinan, Jazmine; Bolduc, Jill; Parmeggiani, Fabio; Baker, David; Stoddard, Barry L.; Bradley, Philip

    2015-01-01

    Tandem repeat proteins, which are formed by repetition of modular units of protein sequence and structure, play important biological roles as macromolecular binding and scaffolding domains, enzymes, and building blocks for the assembly of fibrous materials1,2. The modular nature of repeat proteins enables the rapid construction and diversification of extended binding surfaces by duplication and recombination of simple building blocks3,4. The overall architecture of tandem repeat protein structures – which is dictated by the internal geometry and local packing of the repeat building blocks – is highly diverse, ranging from extended, super-helical folds that bind peptide, DNA, and RNA partners5–9, to closed and compact conformations with internal cavities suitable for small molecule binding and catalysis10. Here we report the development and validation of computational methods for de novo design of tandem repeat protein architectures driven purely by geometric criteria defining the inter-repeat geometry, without reference to the sequences and structures of existing repeat protein families. We have applied these methods to design a series of closed alpha-solenoid11 repeat structures (alpha-toroids) in which the inter-repeat packing geometry is constrained so as to juxtapose the N- and C-termini; several of these designed structures have been validated by X-ray crystallography. Unlike previous approaches to tandem repeat protein engineering12–20, our design procedure does not rely on template sequence or structural information taken from natural repeat proteins and hence can produce structures unlike those seen in nature. As an example, we have successfully designed and validated closed alpha-solenoid repeats with a left-handed helical architecture that – to our knowledge – is not yet present in the protein structure database21. PMID:26675735

  8. Rational design of α-helical tandem repeat proteins with closed architectures.

    Science.gov (United States)

    Doyle, Lindsey; Hallinan, Jazmine; Bolduc, Jill; Parmeggiani, Fabio; Baker, David; Stoddard, Barry L; Bradley, Philip

    2015-12-24

    Tandem repeat proteins, which are formed by repetition of modular units of protein sequence and structure, play important biological roles as macromolecular binding and scaffolding domains, enzymes, and building blocks for the assembly of fibrous materials. The modular nature of repeat proteins enables the rapid construction and diversification of extended binding surfaces by duplication and recombination of simple building blocks. The overall architecture of tandem repeat protein structures--which is dictated by the internal geometry and local packing of the repeat building blocks--is highly diverse, ranging from extended, super-helical folds that bind peptide, DNA, and RNA partners, to closed and compact conformations with internal cavities suitable for small molecule binding and catalysis. Here we report the development and validation of computational methods for de novo design of tandem repeat protein architectures driven purely by geometric criteria defining the inter-repeat geometry, without reference to the sequences and structures of existing repeat protein families. We have applied these methods to design a series of closed α-solenoid repeat structures (α-toroids) in which the inter-repeat packing geometry is constrained so as to juxtapose the amino (N) and carboxy (C) termini; several of these designed structures have been validated by X-ray crystallography. Unlike previous approaches to tandem repeat protein engineering, our design procedure does not rely on template sequence or structural information taken from natural repeat proteins and hence can produce structures unlike those seen in nature. As an example, we have successfully designed and validated closed α-solenoid repeats with a left-handed helical architecture that--to our knowledge--is not yet present in the protein structure database.

  9. [Repeated measurement of memory with valenced test items: verbal memory, working memory and autobiographic memory].

    Science.gov (United States)

    Kuffel, A; Terfehr, K; Uhlmann, C; Schreiner, J; Löwe, B; Spitzer, C; Wingenfeld, K

    2013-07-01

    A large number of questions in clinical and/or experimental neuropsychology require the multiple repetition of memory tests at relatively short intervals. Studies on the impact of the associated exercise and interference effects on the validity of the test results are rare. Moreover, hardly any neuropsychological instruments exist to date to record the memory performance with several parallel versions in which the emotional valence of the test material is also taken into consideration. The aim of the present study was to test whether a working memory test (WST, a digit-span task with neutral or negative distraction stimuli) devised by our workgroup can be used with repeated measurements. This question was also examined in parallel versions of a wordlist learning paradigm and an autobiographical memory test (AMT). Both tests contained stimuli with neutral, positive and negative valence. Twenty-four participants completed the memory testing including the working memory test and three versions of a wordlist and the AMT at intervals of a week apiece (measuring points 1. - 3.). The results reveal consistent performances across the three measuring points in the working and autobiographical memory test. The valence of the stimulus material did not influence the memory performance. In the delayed recall of the wordlist an improvement in memory performance over time was seen. The tests on working memory presented and the parallel versions for the declarative and autobiographical memory constitute informal economic instruments within the scope of the measurement repeatability designs. While the WST and AMT are appropriate for study designs with repeated measurements at relatively short intervals, longer intervals might seem more favourable for the use of wordlist learning paradigms. © Georg Thieme Verlag KG Stuttgart · New York.

  10. High-precision repeat-groundtrack orbit design and maintenance for Earth observation missions

    Science.gov (United States)

    He, Yanchao; Xu, Ming; Jia, Xianghua; Armellin, Roberto

    2017-02-01

    The focus of this paper is the design and station keeping of repeat-groundtrack orbits for Sun-synchronous satellites. A method to compute the semimajor axis of the orbit is presented together with a station-keeping strategy to compensate for the perturbation due to the atmospheric drag. The results show that the nodal period converges gradually with the increase of the order used in the zonal perturbations up to J_{15} . A differential correction algorithm is performed to obtain the nominal semimajor axis of the reference orbit from the inputs of the desired nodal period, eccentricity, inclination and argument of perigee. To keep the satellite in the proximity of the repeat-groundtrack condition, a practical orbit maintenance strategy is proposed in the presence of errors in the orbital measurements and control, as well as in the estimation of the semimajor axis decay rate. The performance of the maintenance strategy is assessed via the Monte Carlo simulation and the validation in a high fidelity model. Numerical simulations substantiate the validity of proposed mean-elements-based orbit maintenance strategy for repeat-groundtrack orbits.

  11. High-precision repeat-groundtrack orbit design and maintenance for Earth observation missions

    Science.gov (United States)

    He, Yanchao; Xu, Ming; Jia, Xianghua; Armellin, Roberto

    2017-06-01

    The focus of this paper is the design and station keeping of repeat-groundtrack orbits for Sun-synchronous satellites. A method to compute the semimajor axis of the orbit is presented together with a station-keeping strategy to compensate for the perturbation due to the atmospheric drag. The results show that the nodal period converges gradually with the increase of the order used in the zonal perturbations up to J_{15}. A differential correction algorithm is performed to obtain the nominal semimajor axis of the reference orbit from the inputs of the desired nodal period, eccentricity, inclination and argument of perigee. To keep the satellite in the proximity of the repeat-groundtrack condition, a practical orbit maintenance strategy is proposed in the presence of errors in the orbital measurements and control, as well as in the estimation of the semimajor axis decay rate. The performance of the maintenance strategy is assessed via the Monte Carlo simulation and the validation in a high fidelity model. Numerical simulations substantiate the validity of proposed mean-elements-based orbit maintenance strategy for repeat-groundtrack orbits.

  12. 数控机床加工在机检测测量头的精准重复定位机构设计%Design of Precisely Repeat Positioning Mechanism for On-machine Measurement Measuring-head of CNC Machine Tool Manufacturing

    Institute of Scientific and Technical Information of China (English)

    陆东明

    2016-01-01

    通过对测量头测量感应技术和无线数据传输技术以及数控机床控制系统信号传输原理的研究,为达到测量头重复定位精度为1μm,设计了磁体组件,利用磁感应力使测量杆精准复位。用此测量头在数控机床上测量直径30 mm标准钢球,经过连续5万次测试,由计算机宏程序软件运算得出的钢球直径数值差异在1μm,符合精密测量工具精度要求。%Based on the research of measuring head sensing technology, wireless data transmission technology and CNC machine tool control signal transmission principle, a set of magnetic subassembly, which utilized the force caused by magnetic induction to reset measuring rod precisely, was designed to achieve repeat positioning accuracy within 1 μm for measuring head.Such measuring head equipped with magnetic subassembly was tested to measure diameter 30 mm standard steel balls on CNC machine tool.After 50 000 times continuously test, the steel ball diameter difference calculated and analyzed by macro program of computer software was controlled less than 1μm.The Testing results prove that the accuracy meets requirements.

  13. 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.

  14. Using repeated measures of sleep disturbances to predict future diagnosis-specific work disability

    DEFF Research Database (Denmark)

    Salo, Paula; Vahtera, Jussi; Hall, Martica

    2012-01-01

    It is unknown whether or not measuring sleep disturbances repeatedly, rather than at only one point in time, improves prediction of work disability.......It is unknown whether or not measuring sleep disturbances repeatedly, rather than at only one point in time, improves prediction of work disability....

  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

    2015-01-01

    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…

  16. 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…

  17. Assessment of bone loss with repeated bone mineral measurements: Application to measurements on the individual patient

    Energy Technology Data Exchange (ETDEWEB)

    Wahner, H.W.

    1987-02-01

    Longitudinal measurements on lumbar spine and mid-radius were made by bone absorptiometry techniques in 139 normal women. Bone mineral was measured every 6 months over an median interval of 2.1 years. The results revealed that bone loss at different skeletal sites is non-uniform with equal bone loss patterns in all patients and relatively small variations in bone loss rate between normal women. For achieving these results there is strong demand on high precision and properly spaced measuring intervals for long-term rate of loss measurements. For exclusion of progressive degenerative disease a radiographic evaluation of the spine in the beginning and at the end of the study is mandatory as compression fractures or trauma reveal bone mineral changes independent from the agerelated bone loss. These repeated bone mineral measurements are useful for monitoring and follow-up studies during different therapeutic regimens.

  18. An L-band SAR for repeat pass deformation measurements on a UAV platform

    Science.gov (United States)

    Hensley, Scott; Lou, Yunling; Rosen, Paul; Wheeler, Kevin; Zebker, Howard; Madsen, Soren; Miller, Tim; Hoffman, Jim; Farra, Don

    2003-01-01

    We are proposing to develop a miniaturized polarimetric L-band synthetic aperture radar (SAR) for repeat-pass differential interferometric measurements of deformation for rapidly deforming surfaces of geophysical interest such as volcanoes or earthquakes that is to be flown on a unmanned aerial vehicle (UAV) or minimally piloted vehicle (MPV). Upon surveying the capabilities and availabilities of such aircraft, the Proteus aircraft and the ALTAIR UAV appear to meet our criteria in terms of payload capabilities, flying altitude, and endurance. To support the repeat pass deformation capability it is necessary to control flight track capability of the aircraft to be within a specified 10 m tube with a goal of 1 m. This requires real-time GPS control of the autopilot to achieve these objectives that has not been demonstrated on these aircraft. Based on the Proteus and ALTAIR's altitude of 13.7 km (45,000 ft), we are designing a fully polarimetric L-band radar with 80 MHz bandwidth and a 16 km range swath. The radar will have an active electronic beam steering antenna to achieve a Doppler centroid stability that is necessary for repeat-pass interferometry. This paper presents some of the trade studies for the platform, instrument and the expected science.

  19. ±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 ...

  20. Repeatability of gait pattern variables measured by use of extremity-mounted inertial measurement units in nonlame horses during trotting.

    Science.gov (United States)

    Cruz, Antonio M; Maninchedda, Ugo E; Burger, Dominik; Wanda, Sabine; Vidondo, Beatriz

    2017-09-01

    OBJECTIVE To determine repeatability of gait variables measured by use of extremity-mounted inertial measurement units (IMUs) in nonlame horses during trotting under controlled conditions of treadmill exercise. ANIMALS 10 horses. PROCEDURES Six IMUs were strapped to the metacarpal, metatarsal, and distal tibial regions of each horse. Data were collected in a standardized manner (3 measurements/d on 3 d/wk over a 3-week period) while each horse was trotted on a treadmill. Every measurement consisted of a minimum of 20 strides from which a minimum of 10 strides was selected for analysis. Spatial and temporal variables were derived from the IMUs. Repeatability coefficients based on the within-subject SD were computed for each gait analysis variable at each week. RESULTS Most of the temporal and spatial variables had high repeatability (repeatability coefficients variables, specifically the symmetry variables (which were calculated from other variables), had somewhat higher repeatability coefficients (ie, lower repeatability) only in the last week. CONCLUSIONS AND CLINICAL RELEVANCE With the exceptions of some symmetry variables, which may reflect individual variations during movement, the extremity-mounted IMUs provided data with high repeatability for nonlame horses trotting under controlled conditions of treadmill exercise. Repeatability was achieved for each instrumented limb segment with regard to the spatial relationship between 2 adjacent segments (joint angles) and the temporal relationship among all segments (limb phasing). Extremity-mounted IMUs could have the potential to become a method for gait analysis in horses.

  1. Estimation of the concordance correlation coefficient for repeated measures using SAS and R.

    Science.gov (United States)

    Carrasco, Josep L; Phillips, Brenda R; Puig-Martinez, Josep; King, Tonya S; Chinchilli, Vernon M

    2013-03-01

    The concordance correlation coefficient is one of the most common approaches used to assess agreement among different observers or instruments when the outcome of interest is a continuous variable. A SAS macro and R package are provided here to estimate the concordance correlation coefficient (CCC) where the design of the data involves repeated measurements by subject and observer. The CCC is estimated using U-statistics (UST) and variance components (VC) approaches. Confidence intervals and standard errors are reported along with the point estimate of the CCC. In the case of the VC approach, the linear mixed model output and variance components estimates are also provided. The performance of each function is shown by means of some examples with real data sets.

  2. Analysis of repeated measurements from medical research when observations are missing

    OpenAIRE

    Walker, K.

    2007-01-01

    Subject dropout is a common problem in repeated measurements health stud ies. Where dropout is related to the response, the results obtained can be substantially biased. The research in this thesis is motivated by a repeated measurements asthma clinical trial with substantial patient dropout. In practice the extent to which missing observations affect parameter esti mates and their efficiency is not clear. Through extensive simulation studies under various scenarios and missing data mechanism...

  3. Role of Repeat Muscle Compartment Pressure Measurements in Chronic Exertional Compartment Syndrome of the Lower Leg

    Science.gov (United States)

    van Zantvoort, Aniek P. M.; de Bruijn, Johan A.; Winkes, Michiel B.; Hoogeveen, Adwin R.; Teijink, Joep A. W.; Scheltinga, Marc R.

    2017-01-01

    Background: The diagnostic gold standard for diagnosing chronic exertional compartment syndrome (CECS) is a dynamic intracompartmental pressure (ICP) measurement of the muscle. The potential role of a repeat ICP (re-ICP) measurement in patients with persistent lower leg symptoms after surgical decompression or with ongoing symptoms after an earlier normal ICP is unknown. Purpose: To study whether re-ICP measurements in patients with persistent CECS-like symptoms of the lower leg may contribute to the diagnosis of CECS after both surgical decompression and a previously normal ICP measurement. Study Design: Case series; Level of evidence, 4. Methods: Charts of patients who underwent re-ICP measurement of lower leg compartments (anterior [ant], deep posterior [dp], and/or lateral [lat] compartments) between 2001 and 2013 were retrospectively studied. CECS was diagnosed on the basis of generally accepted cutoff pressures for newly onset CECS (Pedowitz criteria: ICP at rest ≥15 mmHg, ≥30 mmHg after 1 minute, or ≥20 mmHg 5 minutes after a provocative test). Factors predicting recurrent CECS after surgery or after a previously normal ICP measurement were analyzed. Results: A total of 1714 ICP measurements were taken in 1513 patients with suspected CECS over a 13-year observation period. In all, 201 (12%) tests were re-ICP measurements for persistent lower leg symptoms. Based on the proposed ICP cutoff values, CECS recurrence was diagnosed in 16 of 62 previously operated compartments (recurrence rate, 26%; 53 patients [64% female]; median age, 24 years; age range, 15-78 years). Recurrence rates were not different among the 3 lower leg CECS compartments (ant-CECS, 17%; dp-CECS, 33%; lat-CECS, 30%; χ2 = 1.928, P = .381). Sex (χ2 = 0.058, P = .810), age (U = 378, z = 1.840, P = .066), bilaterality (χ2 = 0.019, P = .889), and prefasciotomy ICP did not predict recurrence. Re-ICP measurements evaluating 20 compartments with previously normal ICP measurements (15

  4. Knowledge-based design of reagentless fluorescent biosensors from a designed ankyrin repeat protein.

    Science.gov (United States)

    Brient-Litzler, Elodie; Plückthun, Andreas; Bedouelle, Hugues

    2010-04-01

    Designed ankyrin repeat proteins (DARPins) can be selected from combinatorial libraries to bind any target antigen. They show high levels of recombinant expression, solubility and stability, and contain no cysteine residue. The possibility of obtaining, from any DARPin and at high yields, fluorescent conjugates which respond to the binding of the antigen by a variation of fluorescence, would have numerous applications in micro- and nano-analytical sciences. This possibility was explored with Off7, a DARPin directed against the maltose binding protein (MalE) from Escherichia coli, with known crystal structure of the complex. Eight residues of Off7, whose solvent accessible surface area varies on association with the antigen but which are not in direct contact with the antigen, were individually mutated into cysteine and then chemically coupled with a fluorophore. The conjugates were ranked according to their relative sensitivities. All of them showed an increase in their fluorescence intensity on antigen binding by >1.7-fold. The best conjugate retained the same affinity as the parental DARPin. Its signal increased linearly and specifically with the concentration of antigen, up to 15-fold in buffer and 3-fold in serum when fully saturated, the difference being mainly due to the absorption of light by serum. Its lower limit of detection was equal to 0.3 nM with a standard spectrofluorometer. Titrations with potassium iodide indicated that the fluorescence variation was due to a shielding of the fluorescent group from the solvent by the antigen. These results suggest rules for the design of reagentless fluorescent biosensors from any DARPin.

  5. Repeatability of Ocular Measurements with a Dual-Scheimpflug Analyzer in Healthy Eyes

    Directory of Open Access Journals (Sweden)

    Carmen Lopez de la Fuente

    2014-01-01

    Full Text Available Purpose. To assess the repeatability of the Galilei dual Scheimpflug analyzer (GDSA in anterior segment examination. Methods. Fifty-two eyes from 52 healthy volunteers were prospectively and consecutively recruited. Anatomic, axial, refractive, and instantaneous parameters were measured with GDSA to provide a complete characterization of the anterior segment. Repeatability was assessed calculating intraclass correlation coefficient (ICC, and coefficient of variation (COV. Results. Correlation among repeated measurements showed almost perfect reliability (ICC > 0.81 for all parameters except thinnest central corneal thickness (CCT (0.78, corneal thickness average out (0.79, and posterior axial curvature average out (0.60. Repeatability was excellent (COV < 10% for all parameters except anterior chamber volume and, superior iridocorneal angle and eccentricities. In these last three parameters, repeatability limits were excessively high compared to the mean. Conclusions. GDSA in healthy young persons had an almost perfect correlation in measuring anatomic, axial, instantaneous, and refractive parameters with greater variability for peripheral terms. Repeatability of anatomical parameters like pachymetry, anterior chamber, or iridocorneal angle and eccentricity were limited. In healthy young persons, the other evaluated parameters had very good repeatability and their limits of agreement showed excellent clinical results for this device.

  6. A Novel Signal Processing Measure to Identify Exact and Inexact Tandem Repeat Patterns in DNA Sequences

    Directory of Open Access Journals (Sweden)

    Ravi Gupta

    2007-03-01

    Full Text Available The identification and analysis of repetitive patterns are active areas of biological and computational research. Tandem repeats in telomeres play a role in cancer and hypervariable trinucleotide tandem repeats are linked to over a dozen major neurodegenerative genetic disorders. In this paper, we present an algorithm to identify the exact and inexact repeat patterns in DNA sequences based on orthogonal exactly periodic subspace decomposition technique. Using the new measure our algorithm resolves the problems like whether the repeat pattern is of period P or its multiple (i.e., 2P, 3P, etc., and several other problems that were present in previous signal-processing-based algorithms. We present an efficient algorithm of O(NLw logLw, where N is the length of DNA sequence and Lw is the window length, for identifying repeats. The algorithm operates in two stages. In the first stage, each nucleotide is analyzed separately for periodicity, and in the second stage, the periodic information of each nucleotide is combined together to identify the tandem repeats. Datasets having exact and inexact repeats were taken up for the experimental purpose. The experimental result shows the effectiveness of the approach.

  7. The concordance correlation coefficient for repeated measures estimated by variance components.

    Science.gov (United States)

    Carrasco, Josep L; King, Tonya S; Chinchilli, Vernon M

    2009-01-01

    The concordance correlation coefficient (CCC) is an index that is commonly used to assess the degree of agreement between observers on measuring a continuous characteristic. Here, a CCC for longitudinal repeated measurements is developed through the appropriate specification of the intraclass correlation coefficient from a variance components linear mixed model. A case example and the results of a simulation study are provided.

  8. 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 li

  9. Design and Implementation of Simultaneous Shield And Repeater Insertion for On-chip Interconnects

    Directory of Open Access Journals (Sweden)

    M. Surendra Goud Mr. Y. Sreenivas Goud

    2012-02-01

    Full Text Available A Resource based optimization is a new approach for high performance integrated circuits. The method is applied to simultaneous shield and repeater insertion, resulting in minimum coupling noise under power, delay, and area constraints Repeater insertion is a well known design technique to reduce the delay required to propagate a signal along a line. Shielding inserts an additional line between a victim line and an aggressor line. Finally placing a shield beside and inserting repeaters along a victim line and are chosen to exemplify the resource based optimization process. In the active shielding architecture shield driving circuits as 4:1 multiplexer, full adder, multipliers are inserted. The power consumption of active shielding architecture is observed to be approximately 20% less compare to passive shielding architecture. The main aim of this is minimize the coupling noise under power, delay, and area constraints

  10. Accuracy and repeatability of a new method for measuring facet loads in the lumbar spine.

    Science.gov (United States)

    Wilson, Derek C; Niosi, Christina A; Zhu, Qingan A; Oxland, Thomas R; Wilson, David R

    2006-01-01

    We assessed the repeatability and accuracy of a relatively new, resistance-based sensor (Tekscan 6900) for measuring lumbar spine facet loads, pressures, and contact areas in cadaver specimens. Repeatability of measurements in the natural facet joint was determined for five trials of four specimens loaded in pure moment (+/- 7.5 N m) flexibility tests in axial rotation and flexion-extension. Accuracy of load measurements in four joints was assessed by applying known compressive loads of 25, 50, and 100 N to the natural facet joint in a materials testing machine and comparing the known applied load to the measured load. Measurements of load were obtained using two different calibration approaches: linear and two-point calibrations. Repeatability for force, pressure, and area (average of standard deviation as a percentage of the mean for all trials over all specimens) was 4-6% for axial rotation and 7-10% for extension. Peak resultant force in axial rotation was 30% smaller when calculated using the linear calibration method. The Tekscan sensor overestimated the applied force by 18 +/- 9% (mean+/-standard deviation), 35 +/- 7% and 50 +/- 9% for compressive loads of 100, 50, and 25 N, respectively. The two-point method overestimated the loads by 35 +/- 16%, 45 +/- 7%, and 56 +/- 10% for the same three loads. Our results show that the Tekscan sensor is repeatable. However, the sensor measurement range is not optimal for the small loads transmitted by the facets and measurement accuracy is highly dependent on calibration protocol.

  11. Repeated quantitative perfusion and contrast permeability measurement in the MRI examination of a CNS tumor

    Energy Technology Data Exchange (ETDEWEB)

    Vonken, E.P.A.; Osch, M.J.P. van; Willems, P.W.A.; Zwan, A. van der; Bakker, C.J.G.; Viergever, M.A.; Mali, W.P.T.M. [University Hospital Utrecht (Netherlands)

    2000-09-01

    This study reports on the results of quantitative MRI perfusion and contrast permeability measurement on two occasions in one patient. The measurements were separated 81 days in time. The tumor grew considerably in this period, but no change was found with respect to perfusion and contrast permeability. Non-involved white matter values were reproduced to demonstrate repeatability. The presented approach to dynamic susceptibility contrast MRI allows fast and repeatable quantitative assessment of perfusion and is easily integrated in a conventional brain tumor protocol. (orig.)

  12. Designed armadillo repeat proteins as general peptide-binding scaffolds: consensus design and computational optimization of the hydrophobic core

    DEFF Research Database (Denmark)

    Parmeggiani, Fabio; Pellarin, Riccardo; Larsen, Anders Peter

    2007-01-01

    interactions with peptides or parts of proteins in extended conformation. The conserved binding mode of the peptide in extended form, observed for different targets, makes armadillo repeat proteins attractive candidates for the generation of modular peptide-binding scaffolds. Taking advantage of the large...... number of repeat sequences available, a consensus-based approach combined with a force field-based optimization of the hydrophobic core was used to derive soluble, highly expressed, stable, monomeric designed proteins with improved characteristics compared to natural armadillo proteins. These sequences...

  13. Intraexaminer repeatability and agreement in stereoacuity measurements made in young adults

    Directory of Open Access Journals (Sweden)

    Beatriz Antona

    2015-04-01

    Full Text Available AIM: To determine the repeatability and agreement of stereoacuity measurements made using some of the most widely used clinical tests: Frisby, TNO, Randot and Titmus. METHODS: Stereoacuity was measured in two different sessions separated by a time interval of at least 24h but no longer than 1wk in 74 subjects of mean age 20.6y using the four methods. The study participants were divided into two groups: subjects with normal binocular vision and subjects with abnormal binocular vision. RESULTS: Best repeatability was shown by the Frisby and Titmus [coefficient of repeatability (COR: ±13 and ±12s arc respectively] in the subjects with normal binocular vision though a clear ceiling effect was noted. In the subjects with abnormal binocular vision, best repeatability was shown by the Frisby (COR: ±69s arc and Randot (COR: ±72s arc. In both groups, the TNO test showed poorest agreement with the other tests. CONCLUSION: The repeatability of stereoacuity measures was low in subjects with poor binocular vision yet fairly good in subjects with normal binocular vision with the exception of the TNO test. The reduced agreement detected between the tests indicates they cannot be used interchangeably.

  14. Repeatability of the modified Thorington card used to measure far heterophoria.

    Science.gov (United States)

    Cebrian, Jose Luis; Antona, Beatriz; Barrio, Ana; Gonzalez, Enrique; Gutierrez, Angel; Sanchez, Isabel

    2014-07-01

    To determine the interexaminer and intraexaminer repeatability of the modified Thorington test (TH) for distance vision in young adults and to compare these results with those observed for the heterophoria tests most commonly used in clinical practice. Agreement among tests was also assessed. Distance heterophoria was quantified on two separate occasions by two examiners in 110 subjects aged 18 to 32 years (mean, 19.74 years; SD, 2.5 years) using four different tests: cover test (CT) Von Graefe, Maddox rod, and modified TH. The repeatability of the tests and agreement between them was estimated by the Bland and Altman method whereby the mean difference and the 95% limits of agreement were determined as the coefficient of repeatability (COR) and coefficient of agreement. The Thorington test showed best interexaminer repeatability (COR = ±1.43Δ), followed closely by CT (COR = ±1.65Δ), whereas best intraexaminer repeatability was observed for CT (COR = ±1.28Δ) followed by TH (COR = ±1.51Δ). Among the different combinations of tests, TH and CT showed best agreement indicated by the lowest coefficient of agreement (±2.23Δ) and a low mean difference (-0.63Δ) between measurements. Good interexaminer and intraexaminer repeatability was observed for both TH and CT, and agreement between the two tests was also good. Given the simple administration of the TH, we recommend its clinical use to quantify distance horizontal heterophoria.

  15. The design and structural characterization of a synthetic pentatricopeptide repeat protein.

    Science.gov (United States)

    Gully, Benjamin S; Shah, Kunal R; Lee, Mihwa; Shearston, Kate; Smith, Nicole M; Sadowska, Agata; Blythe, Amanda J; Bernath-Levin, Kalia; Stanley, Will A; Small, Ian D; Bond, Charles S

    2015-02-01

    Proteins of the pentatricopeptide repeat (PPR) superfamily are characterized by tandem arrays of a degenerate 35-amino-acid α-hairpin motif. PPR proteins are typically single-stranded RNA-binding proteins with essential roles in organelle biogenesis, RNA editing and mRNA maturation. A modular, predictable code for sequence-specific binding of RNA by PPR proteins has recently been revealed, which opens the door to the de novo design of bespoke proteins with specific RNA targets, with widespread biotechnological potential. Here, the design and production of a synthetic PPR protein based on a consensus sequence and the determination of its crystal structure to 2.2 Å resolution are described. The crystal structure displays helical disorder, resulting in electron density representing an infinite superhelical PPR protein. A structural comparison with related tetratricopeptide repeat (TPR) proteins, and with native PPR proteins, reveals key roles for conserved residues in directing the structure and function of PPR proteins. The designed proteins have high solubility and thermal stability, and can form long tracts of PPR repeats. Thus, consensus-sequence synthetic PPR proteins could provide a suitable backbone for the design of bespoke RNA-binding proteins with the potential for high specificity.

  16. Australian House Prices: A Comparison of Hedonic and Repeat-sales Measures

    OpenAIRE

    James Hansen

    2006-01-01

    House prices are intrinsically difficult to measure due to changes in the composition of properties sold through time and changes in the quality of housing. I provide an overview of the theoretical nature of these issues and consider how regression-based measures of house prices – hedonic and repeat-sales measures – can control for compositional and quality change. I then explore whether these regression-based alternatives can provide accurate estimates of pure house price changes in the Aust...

  17. Concordance correlation coefficients estimated by generalized estimating equations and variance components for longitudinal repeated measurements.

    Science.gov (United States)

    Tsai, Miao-Yu

    2017-04-15

    The concordance correlation coefficient (CCC) is a commonly accepted measure of agreement between two observers for continuous responses. This paper proposes a generalized estimating equations (GEE) approach allowing dependency between repeated measurements over time to assess intra-agreement for each observer and inter- and total agreement among multiple observers simultaneously. Furthermore, the indices of intra-, inter-, and total agreement through variance components (VC) from an extended three-way linear mixed model (LMM) are also developed with consideration of the correlation structure of longitudinal repeated measurements. Simulation studies are conducted to compare the performance of the GEE and VC approaches for repeated measurements from longitudinal data. An application of optometric conformity study is used for illustration. In conclusion, the GEE approach allowing flexibility in model assumptions and correlation structures of repeated measurements gives satisfactory results with small mean square errors and nominal 95% coverage rates for large data sets, and when the assumption of the relationship between variances and covariances for the extended three-way LMM holds, the VC approach performs outstandingly well for all sample sizes. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Repeatability of cardiac-MRI-measured right ventricular size and function in congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Rowan; Salem, Yishay [Mount Sinai School of Medicine, Division of Pediatric Cardiology, New York, NY (United States); Shah, Amee; Lai, Wyman W. [Morgan Stanley Children' s Hospital of New York Presbyterian, New York, NY (United States); Nielsen, James C. [Mount Sinai School of Medicine, Division of Pediatric Cardiology, New York, NY (United States); Mount Sinai Children' s Heart Center, Box 1201, New York, NY (United States)

    2011-08-15

    The measurement error for right ventricular (RV) size and function assessed by cardiac MRI (CMRI) in congenital heart disease has not been fully characterized. As CMRI parameters are being increasingly utilized to make clinical decisions, defining error in the clinical setting is critical. This investigation examines the repeatability of CMRI for RV size and function. Forty consecutive people with congenital heart disease involving the RV were retrospectively identified. Contouring of RV volumes was performed by two expert CMRI clinicians. The coefficient of variability and repeatability coefficients were calculated. Repeatability coefficients were multiplied by the mean value for each group studied to define a threshold beyond which measurement error was unlikely to be responsible. The variability for indexed RV end-diastolic volume = 3.2% and 3.3% for intra- and interobserver comparisons, respectively. The repeatability coefficients were 13.2% and 14.9% for intra- and interobserver comparisons, which yielded threshold values of 15.1 ml/m{sup 2} and 20.2 ml/m{sup 2}, respectively. For RV ejection fraction (EF), the repeatability coefficients for intra- and interobserver comparisons were 5.0% and 6.0%, which resulted in threshold values of 2.6 EF% and 3.0 EF%. The threshold values generated can be used during serial assessment of RV size and function. (orig.)

  19. Accuracy and repeatability of an optical motion analysis system for measuring small deformations of biological tissues.

    Science.gov (United States)

    Liu, Helen; Holt, Cathy; Evans, Sam

    2007-01-01

    Optical motion analysis techniques have been widely used in biomechanics for measuring large-scale motions such as gait, but have not yet been significantly explored for measuring smaller movements such as the tooth displacements under load. In principle, very accurate measurements could be possible and this could provide a valuable tool in many engineering applications. The aim of this study was to evaluate accuracy and repeatability of the Qualisys ProReflex-MCU120 system when measuring small displacements, as a step towards measuring tooth displacements to characterise the properties of the periodontal ligament. Accuracy and repeatability of the system was evaluated using a wedge comparator with a resolution of 0.25 microm to provide measured marker displacements in three orthogonal directions. The marker was moved in ten steps in each direction, for each of seven step sizes (0.5, 1, 2, 3, 5, 10, and 20 microm), repeated five times. Spherical and diamond markers were tested. The system accuracy (i.e. percentage of maximum absolute error in range/measurement range), in the 20-200 microm ranges, was +/-1.17%, +/-1.67% and +/-1.31% for the diamond marker in x, y and z directions, while the system accuracy for the spherical marker was +/-1.81%, +/-2.37% and +/-1.39%. The system repeatability (i.e. maximum standard deviation in the measurement range) measured under the different days, light intensity and temperatures for five times, carried out step up and then step down measurements for the same step size, was +/-1.7, +/-2.3 and +/-1.9 microm for the diamond marker, and +/-2.6, +/-3.9 and +/-1.9 microm for the spherical marker in x, y and z directions, respectively. These results demonstrate that the system suffices accuracy for measuring tooth displacements and could potentially be useful in many other applications.

  20. 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.

  1. Graphic Methods for Interpreting Longitudinal Dyadic Patterns From Repeated-Measures Actor-Partner Interdependence Models

    DEFF Research Database (Denmark)

    Perry, Nicholas; Baucom, Katherine; Bourne, Stacia

    2017-01-01

    Researchers commonly use repeated-measures actor–partner interdependence models (RM-APIM) to understand how romantic partners change in relation to one another over time. However, traditional interpretations of the results of these models do not fully or correctly capture the dyadic temporal...

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

    NARCIS (Netherlands)

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

    2011-01-01

    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 r

  3. 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.

  4. REPEATABILITY OF THE SUGAR ABSORPTION TEST, USING LACTULOSE AND MANNITOL, FOR MEASURING INTESTINAL PERMEABILITY FOR SUGARS

    NARCIS (Netherlands)

    VANELBURG, RM; UIL, JJ; KOKKE, FTM; MULDER, AM; VANDEBROEK, WGM; MULDER, CJJ; HEYMANS, HSA

    1995-01-01

    Differential sugar-absorption tests for measuring intestinal permeability for sugars have been studied in a variety of gastrointestinal diseases. Their use in general practice has been hampered by a lack of data on reference values and repeatability of the test and the laboratory assay. In this stud

  5. The Multilevel Approach to Repeated Measures for Complete and Incomplete Data

    NARCIS (Netherlands)

    Maas, CJM; Snijders, TAB

    2003-01-01

    Repeated measurements often are analyzed by multivariate analysis of variance (MANOVA). An alternative approach is provided by multilevel analysis, also called the hierarchical linear model (HLM), which makes use of random coefficient models. This paper is a tutorial which indicates that the HLM can

  6. 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.

  7. Optimal selection of individuals for repeated covariate measurements in follow-up studies.

    Science.gov (United States)

    Reinikainen, Jaakko; Karvanen, Juha; Tolonen, Hanna

    2016-12-01

    Repeated covariate measurements bring important information on the time-varying risk factors in long epidemiological follow-up studies. However, due to budget limitations, it may be possible to carry out the repeated measurements only for a subset of the cohort. We study cost-efficient alternatives for the simple random sampling in the selection of the individuals to be remeasured. The proposed selection criteria are based on forms of the D-optimality. The selection methods are compared with the simulation studies and illustrated with the data from the East-West study carried out in Finland from 1959 to 1999. The results indicate that cost savings can be achieved if the selection is focused on the individuals with high expected risk of the event and, on the other hand, on those with extreme covariate values in the previous measurements. © The Author(s) 2014.

  8. Intraexaminer repeatability and agreement in stereoacuity measurements made in young adults

    Institute of Scientific and Technical Information of China (English)

    Beatriz; Antona; Ana; Barrio; Isabel; Sanchez; Enrique; Gonzalez; Guadalupe; Gonzalez

    2015-01-01

    AIM: To determine the repeatability and agreement of stereoacuity measurements made using some of the most widely used clinical tests: Frisby, TNO, Randot and Titmus.METHODS: Stereoacuity was measured in two different sessions separated by a time interval of at least 24 h but no longer than 1wk in 74 subjects of mean age 20.6y using the four methods. The study participants were divided into two groups: subjects with normal binocular vision and subjects with abnormal binocular vision.RESULTS: Best repeatability was shown by the Frisby and Titmus [coefficient of repeatability(COR): ±13 and±12s arc respectively] in the subjects with normal binocular vision though a clear ceiling effect was noted.In the subjects with abnormal binocular vision, best repeatability was shown by the Frisby(COR: ±69s arc)and Randot(COR: ±72s arc). In both groups, the TNO test showed poorest agreement with the other tests.CONCLUSION:Therepeatabilityofstereoacuitymeasures was low in subjects with poor binocular vision yet fairly good in subjects with normal binocular vision with the exception of the TNO test. The reduced agreement detected between the tests indicates they cannot be used interchangeably.

  9. Repeatability and reproducibility of optic nerve head perfusion measurements using optical coherence tomography angiography

    Science.gov (United States)

    Chen, Chieh-Li; Bojikian, Karine D.; Xin, Chen; Wen, Joanne C.; Gupta, Divakar; Zhang, Qinqin; Mudumbai, Raghu C.; Johnstone, Murray A.; Chen, Philip P.; Wang, Ruikang K.

    2016-06-01

    Optical coherence tomography angiography (OCTA) has increasingly become a clinically useful technique in ophthalmic imaging. We evaluate the repeatability and reproducibility of blood perfusion in the optic nerve head (ONH) measured using optical microangiography (OMAG)-based OCTA. Ten eyes from 10 healthy volunteers are recruited and scanned three times with a 68-kHz Cirrus HD-OCT 5000-based OMAG prototype system (Carl Zeiss Meditec Inc., Dublin, California) centered at the ONH involving two separate visits within six weeks. Vascular images are generated with OMAG processing by detecting the differences in OCT signals between consecutive B-scans acquired at the same retina location. ONH perfusion is quantified as flux, vessel area density, and normalized flux within the ONH for the prelaminar, lamina cribrosa, and the full ONH. Coefficient of variation (CV) and intraclass correlation coefficient (ICC) are used to evaluate intravisit and intervisit repeatability, and interobserver reproducibility. ONH perfusion measurements show high repeatability [CV≤3.7% (intravisit) and ≤5.2% (intervisit)] and interobserver reproducibility (ICC≤0.966) in all three layers by three metrics. OCTA provides a noninvasive method to visualize and quantify ONH perfusion in human eyes with excellent repeatability and reproducibility, which may add additional insight into ONH perfusion in clinical practice.

  10. Repeatability, variability and reference values of pulsed wave Doppler echocardiographic measurements in healthy Saanen goats

    Directory of Open Access Journals (Sweden)

    Leroux Aurélia A

    2012-10-01

    Full Text Available Abstract Background Pulsed wave (PW Doppler echocardiography has become a routine non invasive cardiac diagnostic tool in most species. However, evaluation of intracardiac blood flow requires reference values, which are poorly documented in goats. The aim of this study was to test the repeatability, the variability, and to establish the reference values of PW measurements in healthy adult Saanen goats. Using a standardised PW Doppler echocardiographic protocol, 10 healthy adult unsedated female Saanen goats were investigated three times at one day intervals by the same observer. Mitral, tricuspid, aortic and pulmonary flows were measured from a right parasternal view, and mitral and aortic flows were also measured from a left parasternal view. The difference between left and right side measurements and the intra-observer inter-day repeatability were tested and then the reference values of PW Doppler echocardiographic parameters in healthy adult female Saanen goats were established. Results As documented in other species, all caprine PW Doppler parameters demonstrated a poor inter-day repeatability and a moderate variability. Tricuspid and pulmonary flows were best evaluated on the right side whereas mitral and aortic flows were best obtained on the left side, and reference values are reported for healthy adult Saanen goats. Conclusions PW Doppler echocardiography allows the measurement of intracardiac blood flow indices in goats. The reference values establishment will help interpreting these indices of cardiac function in clinical cardiac cases and developing animal models for human cardiology research.

  11. Using the Monte Carlo Simulation Methods in Gauge Repeatability and Reproducibility of Measurement System Analysis

    Directory of Open Access Journals (Sweden)

    Tsu-Ming Yeh

    2013-10-01

    Full Text Available Measurements are required to maintain the consistent quality of all finished and semi-finished products in a production line. Many firms in the automobile and general precision industries apply the TS 16949:2009 Technical Specifications and Measurement System Analysis (MSA manual to establish measurement systems. This work is undertaken to evaluate gauge repeatability and reproducibility (GR&R to verify the measuring ability and quality of the measurement frame, as well as to continuously improve and maintain the verification process. Nevertheless, the implementation of GR&R requires considerable time and manpower, and is likely to affect production adversely. In addition, the evaluation value for GR&R is always different owing to the sum of man-made and machine-made variations. Using a Monte Carlo simulation and the prediction of the repeatability and reproducibility of the measurement system analysis, this study aims to determine the distribution of %GR&R and the related number of distinct categories (ndc. This study uses two case studies of an automobile parts manufacturer and the combination of a Monte Carlo simulation, statistical bases, and the prediction of the repeatability and reproducibility of the measurement system analysis to determine the probability density function, the distribution of %GR&R, and the related number of distinct categories (ndc. The method used in this study could evaluate effectively the possible range of the GR&R of the measurement capability, in order to establish a prediction model for the evaluation of the measurement capacity of a measurement system.

  12. 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.

  13. 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

    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...... 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...

  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. DC Magnetics Measurement System Design

    Science.gov (United States)

    Mastny, Timothy

    2012-01-01

    This report will detail the updates to the magnetics measurement system design and testing procedures that are required for performing static (DC) magnetics testing of future flight hardware. An older magnetics testing system had to be integrated with new procedures and hardware to meet the demands of future testing programs and accommodate an upcoming magnetics tests. The next test will be for the Geostationary Operational Environmental Satellite R-Series (GOES-R), which will verify that the SAFT Battery component meets its specifications for magnetic cleanliness. The satellite is scheduled to launch in 2015 with magnetics testing to be completed on the battery in November 2012.

  16. Simulation for clinical repeated-dose pharmacokinetic trials applying a peak-and-trough sampling design to estimate oral clearance.

    Science.gov (United States)

    Ishida, Kazuya; Kayano, Yuichiro; Taguchi, Masato; Hashimoto, Yukiya

    2007-11-01

    We performed a simulation for the clinical pharmacokinetic study, in which blood was sampled at two time points corresponding to the peak concentration (C(peak)) and trough concentration (C(trough)) following repetitive oral drug administration to subjects. We estimated the approximate oral clearance (CL/F(approx)) as 2.D/(C(peak).tau+C(trough).tau), where D is the dose, and tau is the dosing interval. The CL/F(approx) value was accurate for drugs with a long-elimination half-life, and the estimation error of the CL/F value was slightly increased for drugs with a shorter elimination half-life. The accuracy of CL/F(approx) in each subject was not affected by the magnitude of the interindividual pharmacokinetic variability, but was significantly decreased by the larger measurement error of drug concentrations (or intraindividual pharmacokinetic variability). We further performed several computer simulations to mimic statistical hypothesis testing following the clinical repeated-dose pharmacokinetic trials. The statistical power to detect the difference of oral clearance between two groups was marginally dependent on the measurement error of drug concentration, but was highly dependent on the interindividual pharmacokinetic variability. These findings suggested that the peak-and-trough sampling design to estimate the CL/F(approx) value is useful for clinical repeated-dose pharmacokinetic trials, and that the study design and protocol should be evaluated carefully by computer simulation prior to a real clinical trial.

  17. 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.

  18. 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

  19. 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.

  20. 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...

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

    Science.gov (United States)

    Kroner, E.; Maboudian, R.; Arzt, E.

    2009-09-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kroner, E; Arzt, E [INM-Leibniz Institute for New Materials, Campus D2 2, 66125 Saarbruecken (Germany); Maboudian, R, E-mail: elmar.kroner@inm-gmbh.de [Department of Chem. Eng., 201 Gilman Hall, University of California, Berkeley, CA 94720-1462 (United States)

    2009-09-15

    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.

  3. Validity and repeatability of a depth camera-based surface imaging system for thigh volume measurement.

    Science.gov (United States)

    Bullas, Alice M; Choppin, Simon; Heller, Ben; Wheat, Jon

    2016-10-01

    Complex anthropometrics such as area and volume, can identify changes in body size and shape that are not detectable with traditional anthropometrics of lengths, breadths, skinfolds and girths. However, taking these complex with manual techniques (tape measurement and water displacement) is often unsuitable. Three-dimensional (3D) surface imaging systems are quick and accurate alternatives to manual techniques but their use is restricted by cost, complexity and limited access. We have developed a novel low-cost, accessible and portable 3D surface imaging system based on consumer depth cameras. The aim of this study was to determine the validity and repeatability of the system in the measurement of thigh volume. The thigh volumes of 36 participants were measured with the depth camera system and a high precision commercially available 3D surface imaging system (3dMD). The depth camera system used within this study is highly repeatable (technical error of measurement (TEM) of <1.0% intra-calibration and ~2.0% inter-calibration) but systematically overestimates (~6%) thigh volume when compared to the 3dMD system. This suggests poor agreement yet a close relationship, which once corrected can yield a usable thigh volume measurement.

  4. Transformers: analysis, design, and measurement

    National Research Council Canada - National Science Library

    López-Fernández, Xose M; Ertan, H. Bülent; Turowski, J

    2013-01-01

    "This book focuses on contemporary economic, design, diagnostics, and maintenance aspects of power, instrument, and high frequency transformers, which are critical to designers for a transformer stations...

  5. Accuracy and repeatability of an inertial measurement unit system for field-based occupational studies.

    Science.gov (United States)

    Schall, Mark C; Fethke, Nathan B; Chen, Howard; Oyama, Sakiko; Douphrate, David I

    2016-04-01

    The accuracy and repeatability of an inertial measurement unit (IMU) system for directly measuring trunk angular displacement and upper arm elevation were evaluated over eight hours (i) in comparison to a gold standard, optical motion capture (OMC) system in a laboratory setting, and (ii) during a field-based assessment of dairy parlour work. Sample-to-sample root mean square differences between the IMU and OMC system ranged from 4.1° to 6.6° for the trunk and 7.2°-12.1° for the upper arm depending on the processing method. Estimates of mean angular displacement and angular displacement variation (difference between the 90th and 10th percentiles of angular displacement) were observed to change IMU system may serve as an acceptable instrument for directly measuring trunk and upper arm postures in field-based occupational exposure assessment studies with long sampling durations. Practitioner Summary: Few studies have evaluated inertial measurement unit (IMU) systems in the field or over long sampling durations. Results of this study indicate that the IMU system evaluated has reasonably good accuracy and repeatability for use in a field setting over a long sampling duration.

  6. Measurement of bedform migration rates on the Lower Missouri River in Missouri, USA using repeat measurements with a multibeam echosounder

    Science.gov (United States)

    Elliott, Caroline M.; Jacobson, Robert B.

    2016-01-01

    High-resolution repeat multibeam echosounder measurements on the Lower Missouri River near Boonville, Missouri, USA show bedform movement and sand storage patterns over daily to seasonal time scales and a range of discharges. Higher flows are frequently, but not always, associated with larger bedforms, higher bedform movement rates, and higher bedload transport rates. Measurements of the temporal and spatial variability in sand dune sizes, transport rates, and sand storage across the river channel have increased understanding of the dynamics of habitats utilized by benthic organisms over multiple life stages and daily to seasonal time scales.

  7. Specific Measurement of Tethered Running Kinetics and its Relationship to Repeated Sprint Ability

    Directory of Open Access Journals (Sweden)

    Sousa Filipe

    2015-12-01

    Full Text Available Repeated sprint ability has been widely studied by researchers, however, analysis of the relationship between most kinetic variables and the effect of fatigue is still an ongoing process. To search for the best biomechanical parameter to evaluate repeated sprint ability, several kinetic variables were measured in a tethered field running test and compared regarding their sensitivity to fatigue and correlation with time trials in a free running condition. Nine male sprint runners (best average times: 100 m = 10.45 ± 0.07 s; 200 m = 21.36 ± 0.17 s; 400 m = 47.35 ± 1.09 s completed two test sessions on a synthetic track. Each session consisted of six 35 m sprints interspersed by 10 s rest under tethered field running or free running conditions. Force, power, work, an impulse and a rate of force development were all directly measured using the sensors of a new tethered running apparatus, and a one-way ANOVA with Scheffé post-hoc test used to verify differences between sprints (p < 0.05. Pearson product-moment correlation measured the relationship between mechanical variables and free running performance. A total impulse, the rate of force development and maximum force did not show significant differences for most sprints. These three variables presented low to moderate correlations with free running performance (r between 0.01 and -0.35. Maximum and mean power presented the strongest correlations with free running performance (r = -0.71 and -0.76, respectively; p < 0.001, followed by mean force (r = -0.61; p < 0.001 and total work (r = -0.50; p < 0.001. It was concluded that under a severe work-to-rest ratio condition, power variables were better suited to evaluating repeated sprint ability than the other studied variables.

  8. Characterisation and measurement of signals generated by DVB-H 'GAP-filler' repeaters.

    Science.gov (United States)

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

    2009-12-01

    DVB-H (Digital Video Broadcasting Handheld) 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.

  9. Measuring the Activity of Leucine-Rich Repeat Kinase 2: A Kinase Involved in Parkinson's Disease

    Science.gov (United States)

    Lee, Byoung Dae; Li, Xiaojie; Dawson, Ted M.; Dawson, Valina L.

    2015-01-01

    Mutations in the LRRK2 (Leucine-Rich Repeat Kinase 2) gene are the most common cause of autosomal dominant Parkinson's disease. LRRK2 has multiple functional domains including a kinase domain. The kinase activity of LRRK2 is implicated in the pathogenesis of Parkinson's disease. Developing an assay to understand the mechanisms of LRRK2 kinase activity is important for the development of pharmacologic and therapeutic applications. Here, we describe how to measure in vitro LRRK2 kinase activity and its inhibition. PMID:21960214

  10. Iterative Weighted Semiparametric Least Squares Estimation in Repeated Measurement Partially Linear Regression Models

    Institute of Scientific and Technical Information of China (English)

    Ge-mai Chen; Jin-hong You

    2005-01-01

    Consider a repeated measurement partially linear regression model with an unknown vector pasemiparametric generalized least squares estimator (SGLSE) ofβ, we propose an iterative weighted semiparametric least squares estimator (IWSLSE) and show that it improves upon the SGLSE in terms of asymptotic covariance matrix. An adaptive procedure is given to determine the number of iterations. We also show that when the number of replicates is less than or equal to two, the IWSLSE can not improve upon the SGLSE.These results are generalizations of those in [2] to the case of semiparametric regressions.

  11. 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.

  12. Repeatability and Accuracy of Exoplanet Eclipse Depths Measured with Post-Cryogenic Spitzer

    CERN Document Server

    Ingalls, James G; Carey, S J; Stauffer, John R; Lawrence, Patrick J; Grillmair, Carl J; Buzasi, Derek; Deming, Drake; Diamond-Lowe, Hannah; Evans, Thomas M; Morello, G; Stevenson, Kevin B; Wong, Ian; Capak, Peter; Glaccum, William; Laine, Seppo; Surace, Jason; Storrie-Lombardi, Lisa

    2016-01-01

    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{\\mu}m dataset, consisting of 10 observations of the XO-3 b system during secondary eclipse, using 7 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 150 parts per million (ppm). Most techniques derive eclipse depths that do not vary by more than a factor 2 of the photon noise limit. Nearly all methods 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 clarify the difference between instrumental and other sources of measurement error, we have also analyzed a simulated datas...

  13. Repeated versus wide reading: A randomized control design study examining the impact of fluency interventions on underlying reading behavior.

    Science.gov (United States)

    Ardoin, Scott P; Binder, Katherine S; Foster, Tori E; Zawoyski, Andrea M

    2016-12-01

    Repeated readings (RR) has garnered much attention as an evidence based intervention designed to improve all components of reading fluency (rate, accuracy, prosody, and comprehension). Despite this attention, there is not an abundance of research comparing its effectiveness to other potential interventions. The current study presents the findings from a randomized control trial study involving the assignment of 168second grade students to a RR, wide reading (WR), or business as usual condition. Intervention students were provided with 9-10weeks of intervention with sessions occurring four times per week. Pre- and post-testing were conducted using Woodcock-Johnson III reading achievement measures (Woodcock, McGrew, & Mather, 2001, curriculum-based measurement (CBM) probes, measures of prosody, and measures of students' eye movements when reading. Changes in fluency were also monitored using weekly CBM progress monitoring procedures. Data were collected on the amount of time students spent reading and the number of words read by students during each intervention session. Results indicate substantial gains made by students across conditions, with some measures indicating greater gains by students in the two intervention conditions. Analyses do not indicate that RR was superior to WR. In addition to expanding the RR literature, this study greatly expands research evaluating changes in reading behaviors that occur with improvements in reading fluency. Implications regarding whether schools should provide more opportunities to repeatedly practice the same text (i.e., RR) or practice a wide range of text (i.e., WR) are provided. Copyright © 2016 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

  14. Repeatability and reproducibility of horizontal corneal diameter and anterior corneal power measurements using the Oculus Keratograph 4

    Directory of Open Access Journals (Sweden)

    Khathutshelo P. Mashige

    2016-03-01

    Full Text Available Purpose: To evaluate the repeatability and reproducibility of horizontal corneal diameter (HCD and anterior corneal power (ACP measurements obtained with the Oculus Keratograph 4 (OCULUS Optikgeräte GmbH.Methods: These parameters (HCD and ACP were prospectively measured in quick succession three times in each of the right eyes of 40 healthy subjects, aged 18–28 years, with normal vision (6/6 or better visual acuity in the first session by a single examiner. Measurements were then repeated in the second session scheduled 1 week later by the same examiner using the same instrument. Repeatability and reproducibility of HCD and ACP measurements was assessed based on the intra-session and intersession within-subject standard deviation (sw, repeatability (2.77sw, coefficient of variation (CoV and intra-class correlation coefficient (ICC.Results: Intra-session repeatability and intersession reproducibility of all measured parameters showed a repeatability (2.77sw of 0.35 mm or less for HCD and 0.35 D or less for ACP, a CoV of 0.30% or less and an ICC of more than 0.9.Conclusion: HCD and ACP measurements obtained using an Oculus Keratograph 4 show good repeatability and reproducibility in healthy eyes; therefore, these parameters can be used for longitudinal follow-up when measured with this device.

  15. 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

    Our understanding of soil deformation processes, especially its dynamics, remains limited. This hampers accurate predictions of the impact of soil management practices such as agricultural field traffic on (physical) soil functions. The main objective of this study was to investigate whether...... seismic measurements could be used to assess the dynamic soil behavior during repeated loading. Moreover, we aimed at linking the velocity of P-waves, Vp, to traditionally measured soil properties associated with soil compaction, namely bulk density (ρb) and penetrometer resistance. A wheeling experiment......, and simulated the evolution of bulk density due to the wheeling using a soil compaction model. The dynamic soil response during loading–unloading–reloading cycles could be well captured with the seismic method. The measured Vp related to bulk density, and the compaction-induced increase in Vp correlated...

  16. 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.

  17. Transformers analysis, design, and measurement

    CERN Document Server

    Lopez-Fernandez, Xose M; Turowski, Janusz

    2012-01-01

    This book focuses on contemporary economic, design, diagnostics, and maintenance aspects of power, instrument, and high frequency transformers, which are critical to designers for a transformer stations. The text covers such topics as shell type and superconducting transformers as well as coreless PCB and planar transformers. It emphasizes challenges and strategies in transformer design and illustrates the importance of economics in transformers management by reviewing life cycle cost design and the use of decision methods to manage risk.

  18. A transcription blocker isolated from a designed repeat protein combinatorial library by in vivo functional screen.

    Science.gov (United States)

    Tikhonova, Elena B; Ethayathulla, Abdul S; Su, Yue; Hariharan, Parameswaran; Xie, Shicong; Guan, Lan

    2015-01-28

    A highly diverse DNA library coding for ankyrin seven-repeat proteins (ANK-N5C) was designed and constructed by a PCR-based combinatorial assembly strategy. A bacterial melibiose fermentation assay was adapted for in vivo functional screen. We isolated a transcription blocker that completely inhibits the melibiose-dependent expression of α-galactosidase (MelA) and melibiose permease (MelB) of Escherichia coli by specifically preventing activation of the melAB operon. High-resolution crystal structural determination reveals that the designed ANK-N5C protein has a typical ankyrin fold, and the specific transcription blocker, ANK-N5C-281, forms a domain-swapped dimer. Functional tests suggest that the activity of MelR, a DNA-binding transcription activator and a member of AraC family of transcription factors, is inhibited by ANK-N5C-281 protein. All ANK-N5C proteins are expected to have a concave binding area with negative surface potential, suggesting that the designed ANK-N5C library proteins may facilitate the discovery of binders recognizing structural motifs with positive surface potential, like in DNA-binding proteins. Overall, our results show that the established library is a useful tool for the discovery of novel bioactive reagents.

  19. Information Contents of a Signal at Repeated Positioning Measurements of the Coordinate Measuring Machine (CMM by Laser Interferometer

    Directory of Open Access Journals (Sweden)

    Stejskal Tomáš

    2016-10-01

    Full Text Available The input of this paper lies in displaying possibilities how to determine the condition of a coordinate measuring machine (CMM based on a large number of repeated measurements. The number of repeated measurements exceeds common requirements for determining positioning accuracy. The total offset in the accuracy of spatial positioning consists of partial inaccuracies of individual axes. 6 basic errors may be defined at each axis. In a triaxial set, that translates into 18 errors, to which an offset from the perpendicularity between the axial pairs must be added. Therefore, the combined number of errors in a single position is 21. These errors are systemic and stem from the machine’s geometry. In addition, there are accidental errors to account for as well. Accidental errors can be attributed to vibrations, mass inertness, passive resistance, and in part to fluctuations in temperature. A peculiar set of systemic errors are time-varying errors. The nature of those errors may be reversible, for instance if they result from influence of temperature or elastic deformation. They can be also irreversible, for example as a result of wear and tear or line clogging, due to loosened connection or permanent deformation of a part post collision. A demonstration of thermal equalizing of the machine’s parts may also be observed in case of failure to adhere to a sufficient time interval from the moment the air-conditioning is turned on. Repeated measurements done on a selected axis with linear interferometer can provide complex information on the CMM condition and also on the machine’s interaction with the given technical environment.

  20. Repeated Microsphere Delivery for Serial Measurement of Regional Blood Perfusion in the Chronically Instrumented, Conscious Canine

    Science.gov (United States)

    Bartoli, Carlo R.; Okabe, Kazunori; Akiyama, Ichiro; Coull, Brent; Godleski, John J.

    2008-01-01

    INTRODUCTION For chronic, repeated hemodynamic studies in conscious dogs, we designed and tested a chronically instrumented canine, microsphere delivery model. The goals of this study were to investigate the accuracy of repeated estimations of blood perfusion using fluorescent-labeled microspheres and to develop and validate a chronic preparation that permits consecutive estimations in the same conscious animal over an extended protocol. METHODS Via thoracotomy, 9 dogs were instrumented with left atrial appendage and aortic vascular access catheters connected to subcutaneous vascular access ports (VAPs). Four animals received 7 serial injections of 1.6 million 15μm microspheres (total: 11.2 million), and five animals received 8 serial injections of 2.25 million microspheres (total: 18 million) over the course of 11 or 18 weeks. RESULTS All catheters have remained bidirectionally patent during protocol for 14.9±0.8 (Mean±SEM) weeks. Sphere accumulation did not significantly alter global myocardial (p=0.69, p=0.25), renal (p=0.92, p=0.12), hepatic (p=0.84, p=0.32), or splenic (p=0.33, p=0.70) blood perfusion in either set of animals. CONCLUSIONS Catheters remained bidirectionally patent for months, did not interfere with the hemodynamic responses of the preparation, and allowed repeat percutaneous injection of microspheres and withdrawal of reference arterial blood from within conscious canines. Eight serial injections totaling 18 million microspheres over 18 weeks did not alter regional myocardial, hepatic, renal, or splenic blood flow. This dependable, chronic, percutaneous arterial access preparation provides a means for examining acute and long-term effects of pathophysiological, pharmaceutical, and environmental influences on regional arterial blood perfusion in conscious, large animals. PMID:17632127

  1. Specific Measurement of Tethered Running Kinetics and its Relationship to Repeated Sprint Ability.

    Science.gov (United States)

    Sousa, Filipe; Dos Reis, Ivan; Ribeiro, Luiz; Martins, Luiz; Gobatto, Claudio

    2015-12-22

    Repeated sprint ability has been widely studied by researchers, however, analysis of the relationship between most kinetic variables and the effect of fatigue is still an ongoing process. To search for the best biomechanical parameter to evaluate repeated sprint ability, several kinetic variables were measured in a tethered field running test and compared regarding their sensitivity to fatigue and correlation with time trials in a free running condition. Nine male sprint runners (best average times: 100 m = 10.45 ± 0.07 s; 200 m = 21.36 ± 0.17 s; 400 m = 47.35 ± 1.09 s) completed two test sessions on a synthetic track. Each session consisted of six 35 m sprints interspersed by 10 s rest under tethered field running or free running conditions. Force, power, work, an impulse and a rate of force development were all directly measured using the sensors of a new tethered running apparatus, and a one-way ANOVA with Scheffé post-hoc test used to verify differences between sprints (p sprints. These three variables presented low to moderate correlations with free running performance (r between 0.01 and -0.35). Maximum and mean power presented the strongest correlations with free running performance (r = -0.71 and -0.76, respectively; p sprint ability than the other studied variables.

  2. Role of Repeat Muscle Compartment Pressure Measurements in Chronic Exertional Compartment Syndrome of the Lower Leg.

    Science.gov (United States)

    van Zantvoort, Aniek P M; de Bruijn, Johan A; Winkes, Michiel B; Hoogeveen, Adwin R; Teijink, Joep A W; Scheltinga, Marc R

    2017-06-01

    The diagnostic gold standard for diagnosing chronic exertional compartment syndrome (CECS) is a dynamic intracompartmental pressure (ICP) measurement of the muscle. The potential role of a repeat ICP (re-ICP) measurement in patients with persistent lower leg symptoms after surgical decompression or with ongoing symptoms after an earlier normal ICP is unknown. To study whether re-ICP measurements in patients with persistent CECS-like symptoms of the lower leg may contribute to the diagnosis of CECS after both surgical decompression and a previously normal ICP measurement. Case series; Level of evidence, 4. Charts of patients who underwent re-ICP measurement of lower leg compartments (anterior [ant], deep posterior [dp], and/or lateral [lat] compartments) between 2001 and 2013 were retrospectively studied. CECS was diagnosed on the basis of generally accepted cutoff pressures for newly onset CECS (Pedowitz criteria: ICP at rest ≥15 mmHg, ≥30 mmHg after 1 minute, or ≥20 mmHg 5 minutes after a provocative test). Factors predicting recurrent CECS after surgery or after a previously normal ICP measurement were analyzed. A total of 1714 ICP measurements were taken in 1513 patients with suspected CECS over a 13-year observation period. In all, 201 (12%) tests were re-ICP measurements for persistent lower leg symptoms. Based on the proposed ICP cutoff values, CECS recurrence was diagnosed in 16 of 62 previously operated compartments (recurrence rate, 26%; 53 patients [64% female]; median age, 24 years; age range, 15-78 years). Recurrence rates were not different among the 3 lower leg CECS compartments (ant-CECS, 17%; dp-CECS, 33%; lat-CECS, 30%; χ(2) = 1.928, P = .381). Sex (χ(2) = 0.058, P = .810), age (U = 378, z = 1.840, P = .066), bilaterality (χ(2) = 0.019, P = .889), and prefasciotomy ICP did not predict recurrence. Re-ICP measurements evaluating 20 compartments with previously normal ICP measurements (15 patients [53% female]; mean age, 31 ± 10 years

  3. 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

  4. 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...

  5. Apparatus designed for very accurate measurement of the optical reflection.

    Science.gov (United States)

    Piombini, Hervé; Voarino, Philippe

    2007-12-20

    The described instrument is a new reflectometer designed to check the normal specular reflectance of 40,000 reflectors necessary for the Laser Megajoule (LMJ). This new reflectometer has a high accuracy over the 400-950 nm wavelength range and allows the delicate measurement of shaped parts. The measurements are relative and several reference mirrors, which are low loss dielectric mirrors [R(lambda)>99.9%], are used for the standardization. The apparatus gives an excellent repeatability (spectrophotometers, our facility and its components are described. The methodology of focusing and calibration are explained. The capabilities of our device are illustrated through some measurements realized on flat or shaped samples.

  6. Crystal Structure of a Designed Tetratricopeptide Repeat Module in Complex with its Peptide Ligand

    Energy Technology Data Exchange (ETDEWEB)

    Cortajarena, A.; Wang, J; Regan, L

    2010-01-01

    Tetratricopeptide repeats (TPRs) are protein domains that mediate key protein-protein interactions in cells. Several TPR domains bind the C-termini of the chaperones heat shock protein (Hsp)90 and/or Hsp70, and exchange of such binding partners is key for the heat shock response. We have previously described the design of a TPR protein that binds tightly and specifically to the C-terminus of Hsp90, and in doing so, is able to inhibit chaperone function in vivo. Here we present the X-ray crystal structure of the designed TPR domain (CTPR390) in complex with its peptide ligand - the C-terminal residues of Hsp90 (peptide MEEVD). This structure reveals two interesting aspects of the TPR modules. First, a new packing arrangement of 3-TPR modules is observed. The TPR units stack against each other in an unusual fashion to form infinite superhelices in the crystal. Second, the structure provides insights into the molecular basis of TPR-ligand recognition.

  7. Prediction Accuracy in Multivariate Repeated-Measures Bayesian Forecasting Models with Examples Drawn from Research on Sleep and Circadian Rhythms

    Directory of Open Access Journals (Sweden)

    Clark Kogan

    2016-01-01

    Full Text Available In study designs with repeated measures for multiple subjects, population models capturing within- and between-subjects variances enable efficient individualized prediction of outcome measures (response variables by incorporating individuals response data through Bayesian forecasting. When measurement constraints preclude reasonable levels of prediction accuracy, additional (secondary response variables measured alongside the primary response may help to increase prediction accuracy. We investigate this for the case of substantial between-subjects correlation between primary and secondary response variables, assuming negligible within-subjects correlation. We show how to determine the accuracy of primary response predictions as a function of secondary response observations. Given measurement costs for primary and secondary variables, we determine the number of observations that produces, with minimal cost, a fixed average prediction accuracy for a model of subject means. We illustrate this with estimation of subject-specific sleep parameters using polysomnography and wrist actigraphy. We also consider prediction accuracy in an example time-dependent, linear model and derive equations for the optimal timing of measurements to achieve, on average, the best prediction accuracy. Finally, we examine an example involving a circadian rhythm model and show numerically that secondary variables can improve individualized predictions in this time-dependent nonlinear model as well.

  8. Prediction Accuracy in Multivariate Repeated-Measures Bayesian Forecasting Models with Examples Drawn from Research on Sleep and Circadian Rhythms.

    Science.gov (United States)

    Kogan, Clark; Kalachev, Leonid; Van Dongen, Hans P A

    2016-01-01

    In study designs with repeated measures for multiple subjects, population models capturing within- and between-subjects variances enable efficient individualized prediction of outcome measures (response variables) by incorporating individuals response data through Bayesian forecasting. When measurement constraints preclude reasonable levels of prediction accuracy, additional (secondary) response variables measured alongside the primary response may help to increase prediction accuracy. We investigate this for the case of substantial between-subjects correlation between primary and secondary response variables, assuming negligible within-subjects correlation. We show how to determine the accuracy of primary response predictions as a function of secondary response observations. Given measurement costs for primary and secondary variables, we determine the number of observations that produces, with minimal cost, a fixed average prediction accuracy for a model of subject means. We illustrate this with estimation of subject-specific sleep parameters using polysomnography and wrist actigraphy. We also consider prediction accuracy in an example time-dependent, linear model and derive equations for the optimal timing of measurements to achieve, on average, the best prediction accuracy. Finally, we examine an example involving a circadian rhythm model and show numerically that secondary variables can improve individualized predictions in this time-dependent nonlinear model as well.

  9. Are There Linguistic Markers of Suicidal Writing That Can Predict the Course of Treatment? A Repeated Measures Longitudinal Analysis.

    Science.gov (United States)

    Brancu, Mira; Jobes, David; Wagner, Barry M; Greene, Jeffrey A; Fratto, Timothy A

    2016-07-02

    The purpose of this pilot study was to predict resolution of suicidal ideation and risk over the course of therapy among suicidal outpatients (N = 144) using a novel method for analyzing Self- verses Relationally oriented qualitative written responses to the Suicide Status Form (SSF). A content analysis software program was used to extract word counts and a repeated measures longitudinal design was implemented to assess improvement over time. Patients with primarily Relationally focused word counts were more likely to have a quicker suicide risk resolution than those with more Self-focused word counts (6-7 sessions versus 17-18 sessions). Implications of these data are discussed, including the potential for enhancing treatment outcomes using this method with individuals entering treatment.

  10. Impact of repeated measures and sample selection on genome-wide association studies of fasting glucose

    Science.gov (United States)

    Rasmussen-Torvik, Laura J.; Alonso, Alvaro; Li, Man; Kao, Wen; Köttgen, Anna; Yan, Yuer; Couper, David; Boerwinkle, Eric; Bielinski, Suzette J.; Pankow, James S.

    2010-01-01

    Although GWAS have been performed in longitudinal studies, most used only a single trait measure. GWAS of fasting glucose have generally included only normoglycemic individuals. We examined the impact of both repeated measures and sample selection on GWAS in ARIC, a study which obtained four longitudinal measures of fasting glucose and included both individuals with and without prevalent diabetes. The sample included Caucasians and the Affymetrix 6.0 chip was used for genotyping. Sample sizes for GWAS analyses ranged from 8372 (first study visit) to 5782 (average fasting glucose). Candidate SNP analyses with SNPs identified through fasting glucose or diabetes GWAS were conducted in 9133 individuals, including 761 with prevalent diabetes. For a constant sample size, smaller p-values were obtained for the average measure of fasting glucose compared to values at any single visit, and two additional significant GWAS signals were detected. For four candidate SNPs (rs780094, rs10830963, rs7903146, and rs4607517), the strength of association between genotype and glucose was significantly (p-interaction fasting glucose candidate SNPs (rs780094, rs10830963, rs560887, rs4607517, rs13266634) the association with measured fasting glucose was more significant in the smaller sample without prevalent diabetes than in the larger combined sample of those with and without diabetes. This analysis demonstrates the potential utility of averaging trait values in GWAS studies and explores the advantage of using only individuals without prevalent diabetes in GWAS of fasting glucose. PMID:20839289

  11. The clinical applicability of a daily summary of patients' self-reported postoperative pain-A repeated measure analysis.

    Science.gov (United States)

    Wikström, Lotta; Eriksson, Kerstin; Fridlund, Bengt; Nilsson, Mats; Årestedt, Kristofer; Broström, Anders

    2017-03-23

    (i) To determine whether a central tendency, median, based on patients' self-rated pain is a clinically applicable daily measure to show patients' postoperative pain on the first day after major surgery (ii) and to determine the number of self-ratings required for the calculation of this measure. Perioperative pain traits in medical records are difficult to overview. The clinical applicability of a daily documented summarising measure of patients' self-rated pain scores is little explored. A repeated measure design was carried out at three Swedish country hospitals. Associations between the measures were analysed with nonparametric statistical methods; systematic and individual group changes were analysed separately. Measure I: pain scores at rest and activity postoperative day 1; measure II: retrospective average pain from postoperative day 1. The sample consisted of 190 general surgery patients and 289 orthopaedic surgery patients with a mean age of 65; 56% were men. Forty-four percent had a pre-operative daily intake of analgesia, and 77% used postoperative opioids. A range of 4-9 pain scores seem to be eligible for the calculation of the daily measures of pain. Rank correlations for individual median scores, based on four ratings, vs. retrospective self-rated average pain, were moderate and strengthened with increased numbers of ratings. A systematic group change towards a higher level of reported retrospective pain was significant. The median values were clinically applicable daily measures. The risk of obtaining a higher value than was recalled by patients seemed to be low. Applicability increased with increased frequency of self-rated pain scores and with high-quality pain assessments. The documenting of daily median pain scores at rest and during activity could constitute the basis for obtaining patients' experiences by showing their pain severity trajectories. The measures could also be an important key to predicting postoperative health

  12. Graphic Methods for Interpreting Longitudinal Dyadic Patterns From Repeated-Measures Actor-Partner Interdependence Models

    DEFF Research Database (Denmark)

    Perry, Nicholas; Baucom, Katherine; Bourne, Stacia

    2017-01-01

    Researchers commonly use repeated-measures actor–partner interdependence models (RM-APIM) to understand how romantic partners change in relation to one another over time. However, traditional interpretations of the results of these models do not fully or correctly capture the dyadic temporal...... patterns estimated in RM-APIM. Interpretation of results from these models largely focuses on the meaning of single-parameter estimates in isolation from all the others. However, considering individual coefficients separately impedes the understanding of how these associations combine to produce...... to improve the understanding and presentation of dyadic patterns of association described by standard RM-APIMs. The current article briefly reviews the conceptual foundations of RM-APIMs, demonstrates how change-as-outcome RM-APIMs and VFDs can aid interpretation of standard RM-APIMs, and provides a tutorial...

  13. Inmate responses to prison-based drug treatment: a repeated measures analysis.

    Science.gov (United States)

    Welsh, Wayne N

    2010-06-01

    Using a sample of 347 prison inmates and general linear modeling (GLM) repeated measures analyses, this paper examined during-treatment responses (e.g., changes in psychological and social functioning) to prison-based TC drug treatment. These effects have rarely been examined in previous studies, and never with a fully multivariate model accounting for within-subjects effects (changes over time), between-subjects effects (e.g., levels of risk and motivation), and within/between-subjects interactions (timexriskxmotivation). The results provide evidence of positive inmate change in response to prison TC treatment, but the patterns of results varied depending upon: (a) specific indicators of psychological and social functioning, motivation, and treatment process; (b) the time periods examined (1, 6, and 12 months during treatment); and (c) baseline levels of risk and motivation. Significant interactions between time and type of inmate suggest important new directions for research, theory, and practice in offender-based substance abuse treatment.

  14. Bayesian latent variable models for hierarchical clustered count outcomes with repeated measures in microbiome studies.

    Science.gov (United States)

    Xu, Lizhen; Paterson, Andrew D; Xu, Wei

    2017-04-01

    Motivated by the multivariate nature of microbiome data with hierarchical taxonomic clusters, counts that are often skewed and zero inflated, and repeated measures, we propose a Bayesian latent variable methodology to jointly model multiple operational taxonomic units within a single taxonomic cluster. This novel method can incorporate both negative binomial and zero-inflated negative binomial responses, and can account for serial and familial correlations. We develop a Markov chain Monte Carlo algorithm that is built on a data augmentation scheme using Pólya-Gamma random variables. Hierarchical centering and parameter expansion techniques are also used to improve the convergence of the Markov chain. We evaluate the performance of our proposed method through extensive simulations. We also apply our method to a human microbiome study.

  15. Causal inference in longitudinal comparative effectiveness studies with repeated measures of a continuous intermediate variable.

    Science.gov (United States)

    Wang, Chen-Pin; Jo, Booil; Brown, C Hendricks

    2014-09-10

    We propose a principal stratification approach to assess causal effects in nonrandomized longitudinal comparative effectiveness studies with a binary endpoint outcome and repeated measures of a continuous intermediate variable. Our method is an extension of the principal stratification approach originally proposed for the longitudinal randomized study "Prevention of Suicide in Primary Care Elderly: Collaborative Trial" to assess the treatment effect on the continuous Hamilton depression score adjusting for the heterogeneity of repeatedly measured binary compliance status. Our motivation for this work comes from a comparison of the effect of two glucose-lowering medications on a clinical cohort of patients with type 2 diabetes. Here, we consider a causal inference problem assessing how well the two medications work relative to one another on two binary endpoint outcomes: cardiovascular disease-related hospitalization and all-cause mortality. Clinically, these glucose-lowering medications can have differential effects on the intermediate outcome, glucose level over time. Ultimately, we want to compare medication effects on the endpoint outcomes among individuals in the same glucose trajectory stratum while accounting for the heterogeneity in baseline covariates (i.e., to obtain 'principal effects' on the endpoint outcomes). The proposed method involves a three-step model estimation procedure. Step 1 identifies principal strata associated with the intermediate variable using hybrid growth mixture modeling analyses. Step 2 obtains the stratum membership using the pseudoclass technique and derives propensity scores for treatment assignment. Step 3 obtains the stratum-specific treatment effect on the endpoint outcome weighted by inverse propensity probabilities derived from Step 2.

  16. Design of a bioactive small molecule that targets r(AUUCU) repeats in spinocerebellar ataxia 10.

    Science.gov (United States)

    Yang, Wang-Yong; Gao, Rui; Southern, Mark; Sarkar, Partha S; Disney, Matthew D

    2016-06-01

    RNA is an important target for chemical probes of function and lead therapeutics; however, it is difficult to target with small molecules. One approach to tackle this problem is to identify compounds that target RNA structures and utilize them to multivalently target RNA. Here we show that small molecules can be identified to selectively bind RNA base pairs by probing a library of RNA-focused small molecules. A small molecule that selectively binds AU base pairs informed design of a dimeric compound (2AU-2) that targets the pathogenic RNA, expanded r(AUUCU) repeats, that causes spinocerebellar ataxia type 10 (SCA10) in patient-derived cells. Indeed, 2AU-2 (50 nM) ameliorates various aspects of SCA10 pathology including improvement of mitochondrial dysfunction, reduced activation of caspase 3, and reduction of nuclear foci. These studies provide a first-in-class chemical probe to study SCA10 RNA toxicity and potentially define broadly applicable compounds targeting RNA AU base pairs in cells.

  17. Designed ankyrin repeat proteins: a new approach to mimic complex antigens for diagnostic purposes?

    Directory of Open Access Journals (Sweden)

    Stefanie Hausammann

    Full Text Available Inhibitory antibodies directed against coagulation factor VIII (FVIII can be found in patients with acquired and congenital hemophilia A. Such FVIII-inhibiting antibodies are routinely detected by the functional Bethesda Assay. However, this assay has a low sensitivity and shows a high inter-laboratory variability. Another method to detect antibodies recognizing FVIII is ELISA, but this test does not allow the distinction between inhibitory and non-inhibitory antibodies. Therefore, we aimed at replacing the intricate antigen FVIII by Designed Ankyrin Repeat Proteins (DARPins mimicking the epitopes of FVIII inhibitors. As a model we used the well-described inhibitory human monoclonal anti-FVIII antibody, Bo2C11, for the selection on DARPin libraries. Two DARPins were selected binding to the antigen-binding site of Bo2C11, which mimic thus a functional epitope on FVIII. These DARPins inhibited the binding of the antibody to its antigen and restored FVIII activity as determined in the Bethesda assay. Furthermore, the specific DARPins were able to recognize the target antibody in human plasma and could therefore be used to test for the presence of Bo2C11-like antibodies in a large set of hemophilia A patients. These data suggest, that our approach might be used to isolate epitopes from different sets of anti-FVIII antibodies in order to develop an ELISA-based screening assay allowing the distinction of inhibitory and non-inhibitory anti-FVIII antibodies according to their antibody signatures.

  18. 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.

  19. Measuring signal generators theory & design

    CERN Document Server

    Rybin, Yuriy K

    2014-01-01

    The book brings together the following issues: Theory of deterministic, random and discrete signals reproducible in oscillatory systems of generators; Generation of periodic signals with a specified spectrum, harmonic distortion factor and random signals with specified probability density function and spectral density; Synthesis of oscillatory system structures; Analysis of oscillatory systems with non-linear elements and oscillation amplitude stabilization systems; It considers the conditions and criteria of steady-state modes in signal generators on active four-pole elements with unidirectional and bidirectional transmission of signals and on two-pole elements; analogues of Barkhausen criteria; Optimization of oscillatory system structures by harmonic distortion level, minimization of a frequency error and set-up time of the steady state mode; Theory of construction of random signal generators; Construction of discrete and digital signal generators; Practical design of main units of generators; Practical bl...

  20. Repeated measures of serum glucose and insulin in relation to postmenopausal breast cancer.

    Science.gov (United States)

    Kabat, Geoffrey C; Kim, Mimi; Caan, Bette J; Chlebowski, Rowan T; Gunter, Marc J; Ho, Gloria Y F; Rodriguez, Beatriz L; Shikany, James M; Strickler, Howard D; Vitolins, Mara Z; Rohan, Thomas E

    2009-12-01

    Experimental and epidemiological evidence suggests that circulating glucose and insulin may play a role in breast carcinogenesis. However, few cohort studies have examined breast cancer risk in association with glucose and insulin levels, and studies to date have had only baseline measurements of exposure. We conducted a longitudinal study of postmenopausal breast cancer risk using the 6% random sample of women in the Women's Health Initiative clinical trials whose fasting blood samples, provided at baseline and at years 1, 3 and 6, were analyzed for glucose and insulin. In addition, a 1% sample of women in the observational study, who had glucose and insulin measured in fasting blood samples drawn at baseline and in year 3, were included in the analysis. We used Cox proportional hazards models to estimate hazard ratios and 95% confidence intervals for the association of baseline and follow-up measurements of serum glucose and insulin with breast cancer risk. All statistical tests were 2-sided. Among 5,450 women with baseline serum glucose and insulin values, 190 incident cases of breast cancer were ascertained over a median of 8.0 years of follow-up. The highest tertile of baseline insulin, relative to the lowest, was associated with a 2-fold increase in risk in the total population (multivariable hazard ratio 2.22, 95% confidence interval 1.39-3.53) and with a 3-fold increase in risk in women who were not enrolled in the intervention arm of any clinical trial (multivariable hazard ratio 3.15, 95% confidence interval 1.61-6.17). Glucose levels showed no association with risk. Analysis of the repeated measurements supported the results of the baseline analysis. These data suggest that elevated serum insulin levels may be a risk factor for postmenopausal breast cancer.

  1. 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, Ppressure. In addition, 2 abnormal childhood/youth blood pressure observations increased the prediction of hypertension 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.

  2. Corneal Topographic and Aberrometric Measurements Obtained with a Multidiagnostic Device in Healthy Eyes: Intrasession Repeatability

    Directory of Open Access Journals (Sweden)

    David P. Piñero

    2017-01-01

    Full Text Available Purpose. To evaluate the intrasession repeatability of corneal curvature, eccentricity, and aberrometric measurements obtained with a multidiagnostic device in healthy eyes. Methods. This study enrolled 107 eyes of 107 patients ranging in age from 23 to 65 years. All of them underwent a complete anterior segment examination with the VX120 system (Visionix-Luneau Technologies, Chartres, France. Three consecutive measurements were obtained. The within-subject standard deviation (Sw, intrasubject precision (1.96×Sw, and intraclass correlation coefficient (ICC were calculated. Results. All Sw for corneal power measurements were below 0.26 D, with ICC above 0.982. The Sw for corneal astigmatism at different areas (3, 5, and 7 mm was below 0.21 D, with ICC above 0.913. Concerning the axis of astigmatism, its Sw was below 11.27°, with ICC above 0.975. The Sw and ICC for corneal eccentricity were 0.067 and 0.957, respectively. The Sw and ICC for high-order aberration root mean square (RMS were 0.048 µm and 0.901, respectively. For 3rd- and 4th-order aberrometric parameters, all Sw were below 0.037 µm and all ICC were higher than 0.84, except for quadrafoil RMS (ICC: 0.689. Conclusions. The multidiagnostic device evaluated is able to provide consistent measurements of corneal power, eccentricity, and third- and fourth-order aberrations in healthy eyes.

  3. Measurement Design for Detecting Sparse Signals

    OpenAIRE

    Zahedi, Ramin; Pezeshki, Ali; Chong, Edwin K. P.

    2011-01-01

    We consider the problem of testing for the presence (or detection) of an unknown sparse signal in additive white noise. Given a fixed measurement budget, much smaller than the dimension of the signal, we consider the general problem of designing compressive measurements to maximize the measurement signal-to-noise ratio (SNR), as increasing SNR improves the detection performance in a large class of detectors. We use a lexicographic optimization approach, where the optimal measurement design fo...

  4. 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.

  5. Constructing Measure by Repeated Infinite Subdivision%通过反复无限细分定义测度

    Institute of Scientific and Technical Information of China (English)

    严质彬

    2005-01-01

    This paper generalizes the method of constructing measure by repeated finite subdivision in fTactal geometry to that by infinite subdivision. Two conditions for the existing method are removed. A measure on the interval [0, 1] is constructed using this generalized method.

  6. Cardiometabolic treatment decisions in patients with type 2 diabetes : the role of repeated measurements and medication burden

    NARCIS (Netherlands)

    Voorham, J.; Haaijer-Ruskamp, F. M.; Wolffenbuttel, B. H. R.; Stolk, R. P.; Denig, P.

    2010-01-01

    Purpose Clinical guidelines for cardiometabolic risk management indicate a simple threshold-based strategy for treatment, but physicians and their patients may be reluctant to modify drug treatment after a single elevated measurement. We determined how repeated measurements of blood pressure, choles

  7. Cardiometabolic treatment decisions in patients with type 2 diabetes : the role of repeated measurements and medication burden

    NARCIS (Netherlands)

    Voorham, J.; Haaijer-Ruskamp, F. M.; Wolffenbuttel, B. H. R.; Stolk, R. P.; Denig, P.

    2010-01-01

    Purpose Clinical guidelines for cardiometabolic risk management indicate a simple threshold-based strategy for treatment, but physicians and their patients may be reluctant to modify drug treatment after a single elevated measurement. We determined how repeated measurements of blood pressure,

  8. Tracking photon jumps with repeated quantum non-demolition parity measurements.

    Science.gov (United States)

    Sun, L; Petrenko, A; Leghtas, Z; Vlastakis, B; Kirchmair, G; Sliwa, K M; Narla, A; Hatridge, M; Shankar, S; Blumoff, J; Frunzio, L; Mirrahimi, M; Devoret, M H; Schoelkopf, R J

    2014-07-24

    Quantum error correction is required for a practical quantum computer because of the fragile nature of quantum information. In quantum error correction, information is redundantly stored in a large quantum state space and one or more observables must be monitored to reveal the occurrence of an error, without disturbing the information encoded in an unknown quantum state. Such observables, typically multi-quantum-bit parities, must correspond to a special symmetry property inherent in the encoding scheme. Measurements of these observables, or error syndromes, must also be performed in a quantum non-demolition way (projecting without further perturbing the state) and more quickly than errors occur. Previously, quantum non-demolition measurements of quantum jumps between states of well-defined energy have been performed in systems such as trapped ions, electrons, cavity quantum electrodynamics, nitrogen-vacancy centres and superconducting quantum bits. So far, however, no fast and repeated monitoring of an error syndrome has been achieved. Here we track the quantum jumps of a possible error syndrome, namely the photon number parity of a microwave cavity, by mapping this property onto an ancilla quantum bit, whose only role is to facilitate quantum state manipulation and measurement. This quantity is just the error syndrome required in a recently proposed scheme for a hardware-efficient protected quantum memory using Schrödinger cat states (quantum superpositions of different coherent states of light) in a harmonic oscillator. We demonstrate the projective nature of this measurement onto a region of state space with well-defined parity by observing the collapse of a coherent state onto even or odd cat states. The measurement is fast compared with the cavity lifetime, has a high single-shot fidelity and has a 99.8 per cent probability per single measurement of leaving the parity unchanged. In combination with the deterministic encoding of quantum information in cat

  9. Assessing variability and comparing short-term biomarkers of styrene exposure using a repeated measurements approach.

    Science.gov (United States)

    Fustinoni, S; Manini, P; Campo, L; De Palma, G; Andreoli, R; Mutti, A; Bertazzi, P A; Rappaport, S M

    2010-01-15

    The aim of this work is to compare several short-term biomarkers of styrene exposure, namely urinary styrene (StyU), mercapturic acids (M1+M2), mandelic acid (MA), phenylglyoxylic acid (PGA), phenylglycine (PHG), and 4-vinylphenol conjugates (VP), for use as biomarkers of exposure in epidemiologic studies. A repeated measurements protocol (typically 4 measurements per worker over 6 weeks) was applied to measure airborne styrene (StyA) and urinary biomarkers in 10 varnish and 8 fiberglass reinforced plastic workers. Estimated geometric mean personal exposures to StyA were 2.96mg/m(3) in varnish workers and 15.7mg/m(3) in plastic workers. The corresponding levels of StyU, M1+M2, MA, PGA, MA+PGA, PHG and VP were 5.13microg/L, 0.111, 38.2, 22.7, 62.6, 0.978, and 3.97mg/g creatinine in varnish workers and 8.38microg/L, 0.303, 146, 83.4, 232, 2.85 and 3.97mg/g creatinine in plastic workers. Within-worker (sigma(wY)(2)) and between-worker (sigma(bY)(2)) variance components were estimated from the log-transformed data as were the corresponding fold ranges containing 95% of the respective lognormal distributions of daily levels ((w)R(0.95)) and subject-specific mean levels ((b)R(0.95)). Estimates of (w)R(0.95) (range: 4-26) were generally smaller than those of (b)R(0.95) (range: 5-790) for both environmental and biological markers; this indicates that exposures varied much more between workers than within workers in these groups. Since attenuation bias in an estimated exposure-response relationship increases with the variance ratio lambda=sigma(wY)(2)/sigma(bY)(2), we estimated values of lambda for all exposure measures in our study. Values of lambda were typically much less than one (median=0.220) and ranged from 0.089 for M1+M2 in plastic workers to 1.38 for PHG in varnish workers. Since values of lambda were 0.147 and 0.271 for StyA in varnish workers and plastic workers, respectively, compared to 0.178 and 0.210 for MA in the same groups, our results suggest that either

  10. Analyzing repeated measures semi-continuous data, with application to an alcohol dependence study.

    Science.gov (United States)

    Liu, Lei; Strawderman, Robert L; Johnson, Bankole A; O'Quigley, John M

    2016-02-01

    Two-part random effects models (Olsen and Schafer,(1) Tooze et al.(2)) have been applied to repeated measures of semi-continuous data, characterized by a mixture of a substantial proportion of zero values and a skewed distribution of positive values. In the original formulation of this model, the natural logarithm of the positive values is assumed to follow a normal distribution with a constant variance parameter. In this article, we review and consider three extensions of this model, allowing the positive values to follow (a) a generalized gamma distribution, (b) a log-skew-normal distribution, and (c) a normal distribution after the Box-Cox transformation. We allow for the possibility of heteroscedasticity. Maximum likelihood estimation is shown to be conveniently implemented in SAS Proc NLMIXED. The performance of the methods is compared through applications to daily drinking records in a secondary data analysis from a randomized controlled trial of topiramate for alcohol dependence treatment. We find that all three models provide a significantly better fit than the log-normal model, and there exists strong evidence for heteroscedasticity. We also compare the three models by the likelihood ratio tests for non-nested hypotheses (Vuong(3)). The results suggest that the generalized gamma distribution provides the best fit, though no statistically significant differences are found in pairwise model comparisons.

  11. Preliminary evaluation of a micro-based repeated measures testing system

    Science.gov (United States)

    Kennedy, Robert S.; Wilkes, Robert L.; Lane, Norman E.

    1985-01-01

    A need exists for an automated performance test system to study the effects of various treatments which are of interest to the aerospace medical community, i.e., the effects of drugs and environmental stress. The ethics and pragmatics of such assessment demand that repeated measures in small groups of subjects be the customary research paradigm. Test stability, reliability-efficiency and factor structure take on extreme significance; in a program of study by the U.S. Navy, 80 percent of 150 tests failed to meet minimum metric requirements. The best is being programmed on a portable microprocessor and administered along with tests in their original formats in order to examine their metric properties in the computerized mode. Twenty subjects have been tested over four replications on a 6.0 minute computerized battery (six tests) and which compared with five paper and pencil marker tests. All tests achieved stability within the four test sessions, reliability-efficiencies were high (r greater than .707 for three minutes testing), and the computerized tests were largely comparable to the paper and pencil version from which they were derived. This computerized performance test system is portable, inexpensive and rugged.

  12. Repeatability and reproducibility of anterior chamber volume measurements using 3-dimensional corneal and anterior segment optical coherence tomography.

    Science.gov (United States)

    Fukuda, Shinichi; Kawana, Keisuke; Yasuno, Yoshiaki; Oshika, Tetsuro

    2011-03-01

    To evaluate the repeatability and reproducibility of anterior chamber volume (ACV) measurements using swept-source 3-dimensional corneal and anterior segment optical coherence tomography (CAS-OCT) and dual Scheimpflug imaging. Department of Ophthalmology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan. Nonrandomized clinical trial. Measurements were taken in normal eyes (subject group) and in eyes with primary angle closure (PAC) (patient group). In the subject group, the entire ACV and the central 8.0 mm diameter ACV were measured using CAS-OCT and dual Scheimpflug imaging. In the patient group, the entire ACV and 8.0 mm ACV were measured using CAS-OCT. The coefficient of variation and intraclass correlation coefficient (ICC) were calculated to evaluate repeatability and reproducibility, and the correlation between the 2 devices was assessed. In the subject group, the mean 8.0 mm ACV was 110.14 mm(3) ± 12.57 (SD) using CAS-OCT and 114.51 ± 14.69 mm(3) using Scheimpflug imaging; there was a significant linear correlation (r = 0.878, P ACV on CAS-OCT was 165.15 ± 29.29 mm(3). The ICCs of the 8.0 mm and entire ACV measurements were greater than 0.94. The coefficients of repeatability and reproducibility of the 8.0 mm ACV and entire ACV measurements were less than 5%. In the patient group, the 8.0 mm and entire ACV measurements showed good reproducibility and repeatability. The CAS-OCT method allowed noninvasive measurement of the entire ACV with sufficient repeatability and reproducibility. The 8.0 mm ACV measurements with CAS-OCT and Scheimpflug imaging were comparable. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  13. Development of the designed ankyrin repeat protein (DARPin) G3 for HER2 molecular imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, Robert; Livanos, Maria; Bhavsar, Gaurav; Rashid, Mohammed; Miranda, Enrique; Tolner, Berend; Meyer, Tim; Chester, Kerry [UCL Cancer Institute, London (United Kingdom); Sosabowski, Jane; Leyton, Julius; Mather, Stephen [Queen Mary University of London, Centre for Molecular Oncology, Barts Cancer Institute, London (United Kingdom); Vigor, Kim [Clare Hall Laboratories, Biotherapeutics Development Unit, Cancer Research UK, South Mimms (United Kingdom); Nagy-Davidescu, Gabriela; Plueckthun, Andreas [Universitaet Zuerich, Biochemisches Institut, Zuerich (Switzerland); Yeung, Jenny [UCL Cancer Institute, London (United Kingdom); UCL Institute of Child Health, London (United Kingdom)

    2014-11-13

    Human epidermal growth factor receptor-2 (HER2) overexpression is a predictor of response to anti-HER2 therapy in breast and gastric cancer. Currently, HER2 status is assessed by tumour biopsy, but this may not be representative of the larger tumour mass or other metastatic sites, risking misclassification and selection of suboptimal therapy. The designed ankyrin repeat protein (DARPin) G3 binds HER2 with high affinity at an epitope that does not overlap with trastuzumab and is biologically inert. We hypothesized that radiolabelled DARPin G3 would be capable of selectively imaging HER2-positive tumours, and aimed to identify a suitable format for clinical application. G3 DARPins tagged with hexahistidine (His{sub 6}) or with histidine glutamate (HE){sub 3} and untagged G3 DARPins were manufactured using a GMP-compatible Pichia pastoris protocol and radiolabelled with {sup 125}I, or with {sup 111}In via DOTA linked to a C-terminal cysteine. BALB/c mice were injected with radiolabelled G3 and tissue biodistribution was evaluated by gamma counting. The lead construct ((HE){sub 3}-G3) was assessed in mice bearing HER2-positive human breast tumour (BT474) xenografts. For both isotopes, (HE){sub 3}-G3 had significantly lower liver uptake than His{sub 6}-G3 and untagged G3 counterparts in non-tumour-bearing mice, and there was no significantly different liver uptake between His{sub 6}-G3 and untagged G3. (HE){sub 3}-G3 was taken forward for evaluation in mice bearing HER2-positive tumour xenografts. The results demonstrated that radioactivity from {sup 111}In-(HE){sub 3}-G3 was better maintained in tumours and cleared faster from serum than radioactivity from {sup 125}I-(HE){sub 3}-G3, achieving superior tumour-to-blood ratios (343.7 ± 161.3 vs. 22.0 ± 11.3 at 24 h, respectively). On microSPECT/CT, {sup 111}In-labelled and {sup 125}I-labelled (HE){sub 3}-G3 could image HER2-positive tumours at 4 h after administration, but there was less normal tissue uptake of

  14. Precision (Repeatability and Reproducibility and Agreement of Corneal Power Measurements Obtained by Topcon KR-1W and iTrace.

    Directory of Open Access Journals (Sweden)

    Yanjun Hua

    Full Text Available To evaluate the repeatability and reproducibility of corneal power measurements obtained by Topcon KR-1W and iTrace, and assess the agreement with measurements obtained by Allegro Topolyzer and IOLMaster.The right eyes of 100 normal subjects were prospectively scanned 3 times using all the 4 devices. Another observer performed additional 3 consecutive scans using the Topcon KR-1W and iTrace in the same session. About one week later, the first observer repeated the measurements using the Topcon KR-1W and iTrace. The steep keratometry (Ks, flat keratometry (Kf, mean keratometry (Km, J0 and J45 were analyzed. Repeatability and reproducibility of measurements were evaluated by the within-subject standard deviation (Sw, coefficient of variation (CoV, test-retest repeatability (2.77Sw, and intraclass correlation coefficient (ICC. Agreements between devices were assessed using Bland-Altman analysis and 95% limits of agreement (LoA.Intraobserver repeatability and interobserver and intersession reproducibility of the Ks, Kf and Km showed a CoV of no more than 0.5%, a 2.77Sw of 0.70 D or less, and an ICC of no less than 0.99. However, J0 and J45 showed poor intraobserver repeatability and interobserver and intersession reproducibility (all ICCs not greater than 0.446. Statistically significant differences existed between Topcon KR-1W and IOLMaster, Topcon KR-1W and iTrace, Topcon KR-1W and Topolyzer, iTrace and Topolyzer, iTrace and IOLMaster for Ks, Kf and Km measurements (all P < 0.05. The mean differences between Topcon KR-1W, iTrace, and the other 2 devices were small. The 95% LoA were approximately 1.0 D to 1.5 D for all measurements.The Ks, Kf and Km obtained by Topcon KR-1W and iTrace showed excellent intraobserver repeatability and interobserver and intersession reproducibility in normal eyes. The agreement between Topcon KR-1W and Topolyzer, Topcon KR-1W and IOLMaster, iTrace and Topolyzer, iTrace and IOLMaster, Topcon KR-1W and iTrace were not

  15. Separating climate-induced mass transfers and instrumental effects from tectonic signal in repeated absolute gravity measurements

    Science.gov (United States)

    Van Camp, M.; Viron, O.; Avouac, J. P.

    2016-05-01

    We estimate the signature of the climate-induced mass transfers in repeated absolute gravity measurements based on satellite gravimetric measurements from the Gravity Recovery and Climate Experiment (GRACE) mission. We show results at the globe scale and compare them with repeated absolute gravity (AG) time behavior in three zones where AG surveys have been published: Northwestern Europe, Canada, and Tibet. For 10 yearly campaigns, the uncertainties affecting the determination of a linear gravity rate of change range 3-4 nm/s2/a in most cases, in the absence of instrumental artifacts. The results are consistent with what is observed for long-term repeated campaigns. We also discuss the possible artifact that can result from using short AG survey to determine the tectonic effects in a zone of high hydrological variability. We call into question the tectonic interpretation of several gravity changes reported from stations in Tibet, in particular the variation observed prior to the 2015 Gorkha earthquake.

  16. Design and analysis of effects of triplet repeat oligonucleotides in cell models for myotonic dystrophy

    NARCIS (Netherlands)

    Gonzalez-Barriga, A.; Mulders, S.A.M.; Giessen, J. van der; Hooijer, J.D.; Bijl, S.; Kessel, I.D.G. van; Beers, J. van; Deutekom, J.C. van; Fransen, J.A.M.; Wieringa, B.; Wansink, D.G.

    2013-01-01

    Myotonic dystrophy type 1 (DM1) is caused by DM protein kinase (DMPK) transcripts containing an expanded (CUG)n repeat. Antisense oligonucleotide (AON)-mediated suppression of these mutant RNAs is considered a promising therapeutic strategy for this severe disorder. Earlier, we identified a 2'-O-met

  17. Design and analysis of effects of triplet repeat oligonucleotides in cell models for myotonic dystrophy

    NARCIS (Netherlands)

    Gonzalez-Barriga, A.; Mulders, S.A.M.; Giessen, J. van der; Hooijer, J.D.; Bijl, S.; Kessel, I.D.G. van; Beers, J. van; Deutekom, J.C. van; Fransen, J.A.M.; Wieringa, B.; Wansink, D.G.

    2013-01-01

    Myotonic dystrophy type 1 (DM1) is caused by DM protein kinase (DMPK) transcripts containing an expanded (CUG)n repeat. Antisense oligonucleotide (AON)-mediated suppression of these mutant RNAs is considered a promising therapeutic strategy for this severe disorder. Earlier, we identified a 2'-O-met

  18. Accounting for uncertainty in volumes of seabed change measured with repeat multibeam sonar surveys

    Science.gov (United States)

    Schimel, Alexandre C. G.; Ierodiaconou, Daniel; Hulands, Lachlan; Kennedy, David M.

    2015-12-01

    Seafloors of unconsolidated sediment are highly dynamic features; eroding or accumulating under the action of tides, waves and currents. Assessing which areas of the seafloor experienced change and measuring the corresponding volumes involved provide insights into these important active sedimentation processes. Computing the difference between Digital Elevation Models (DEMs) obtained from repeat Multibeam Echosounders (MBES) surveys has become a common technique to identify these areas, but the uncertainty in these datasets considerably affects the estimation of the volumes displaced. The two main techniques used to take into account uncertainty in volume estimations are the limitation of calculations to areas experiencing a change in depth beyond a chosen threshold, and the computation of volumetric confidence intervals. However, these techniques are still in their infancy and, as a result, are often crude, seldom used or poorly understood. In this article, we explored a number of possible methodological advances to address this issue, including: (1) using the uncertainty information provided by the MBES data processing algorithm CUBE, (2) adapting fluvial geomorphology techniques for volume calculations using spatially variable thresholds and (3) volumetric histograms. The nearshore seabed off Warrnambool harbour - located in the highly energetic southwest Victorian coast, Australia - was used as a test site. Four consecutive MBES surveys were carried out over a four-months period. The difference between consecutive DEMs revealed an area near the beach experiencing large sediment transfers - mostly erosion - and an area of reef experiencing increasing deposition from the advance of a nearby sediment sheet. The volumes of sediment displaced in these two areas were calculated using the techniques described above, both traditionally and using the suggested improvements. We compared the results and discussed the applicability of the new methodological improvements

  19. Intensive Measurement Designs for Research on Aging.

    Science.gov (United States)

    Rast, Philippe; Macdonald, Stuart W S; Hofer, Scott M

    2012-01-01

    Intensive measurement burst designs permit analysis of behavioral and biological processes as they unfold over short and long periods of time and providing the opportunity to identify change from an individual's normative level of functioning. The measurement burst design permits statistical decomposition of short-term variation and learning effects that overlay normative aging and provide stronger bases for detecting accelerated change due to pathological processes. We provide an overview of design features and analysis of measurement burst data in Project MIND. The objective of intensive measurement designs is to obtain greater resolution of processes of interest that permit reliable and sensitive assessments of functioning and change in functioning and of key determinants underlying short-term variation and long-term aging and health-related change.

  20. 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.

  1. 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.

  2. Measuring and Communicating Emotions Through Game Design

    DEFF Research Database (Denmark)

    Knutz, Eva; Markussen, Thomas

    2010-01-01

    . Second, healthcare personal and design researchers can use the CPgame to gain knowledge of this patient group as it measures the children’s subjective feelings about their emotions. In the paper we discuss how key theoretical concepts of emotion may help the designer to identify the basic building blocks...

  3. 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...

  4. GSTM1 and APE1 genotypes affect arsenic-induced oxidative stress: a repeated measures study

    Directory of Open Access Journals (Sweden)

    Quamruzzaman Quazi

    2007-12-01

    Full Text Available Abstract Background Chronic arsenic exposure is associated with an increased risk of skin, bladder and lung cancers. Generation of oxidative stress may contribute to arsenic carcinogenesis. Methods To investigate the association between arsenic exposure and oxidative stress, urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG was evaluated in a cohort of 97 women recruited from an arsenic-endemic region of Bangladesh in 2003. Arsenic exposure was measured in urine, toenails, and drinking water. Drinking water and urine samples were collected on three consecutive days. Susceptibility to oxidative stress was evaluated by genotyping relevant polymorphisms in glutathione-s transferase mu (GSTM1, human 8-oxoguanine glycosylase (hOGG1 and apurinic/apyrimidinic endonuclease (APE1 genes using the Taqman method. Data were analyzed using random effects Tobit regression to account for repeated measures and 8-OHdG values below the detection limit. Results A consistent negative effect for APE1 was observed across water, toenail and urinary arsenic models. APE1 148 glu/glu + asp/glu genotype was associated with a decrease in logged 8-OHdG of 0.40 (95%CI -0.73, -0.07 compared to APE1 148 asp/asp. An association between total urinary arsenic and 8-OHdG was observed among women with the GSTM1 null genotype but not in women with GSTM1 positive. Among women with GSTM1 null, a comparison of the second, third, and fourth quartiles of total urinary arsenic to the first quartile resulted in a 0.84 increase (95% CI 0.27, 1.42, a 0.98 increase (95% CI 033, 1.66 and a 0.85 increase (95% CI 0.27, 1.44 in logged 8-OHdG, respectively. No effects between 8-OHdG and toenail arsenic or drinking water arsenic were observed. Conclusion These results suggest the APE1 variant genotype decreases repair of 8-OHdG and that arsenic exposure is associated with oxidative stress in women who lack a functional GSTM1 detoxification enzyme.

  5. Pilot study: Assessing repeatability of the EcoWalk platform resistive pressure sensors to measure plantar pressure during barefoot standing

    Science.gov (United States)

    Zequera, Martha; Perdomo, Oscar; Wilches, Carlos; Vizcaya, Pedro

    2013-06-01

    Plantar pressure provides useful information to assess the feet's condition. These systems have emerged as popular tools in clinical environment. These systems present errors and no compensation information is presented by the manufacturer, leading to uncertainty in the measurements. Ten healthy subjects, 5 females and 5 males, were recruited. Lateral load distribution, antero-posterior load distribution, average pressure, contact area, and force were recorded. The aims of this study were to assess repeatability of the EcoWalk system and identify the range of pressure values observed in the normal foot. The coefficient of repeatability was less than 4% for all parameters considered.

  6. Information optimal compressive sensing: static measurement design.

    Science.gov (United States)

    Ashok, Amit; Huang, Liang-Chih; Neifeld, Mark A

    2013-05-01

    The compressive sensing paradigm exploits the inherent sparsity/compressibility of signals to reduce the number of measurements required for reliable reconstruction/recovery. In many applications additional prior information beyond signal sparsity, such as structure in sparsity, is available, and current efforts are mainly limited to exploiting that information exclusively in the signal reconstruction problem. In this work, we describe an information-theoretic framework that incorporates the additional prior information as well as appropriate measurement constraints in the design of compressive measurements. Using a Gaussian binomial mixture prior we design and analyze the performance of optimized projections relative to random projections under two specific design constraints and different operating measurement signal-to-noise ratio (SNR) regimes. We find that the information-optimized designs yield significant, in some cases nearly an order of magnitude, improvements in the reconstruction performance with respect to the random projections. These improvements are especially notable in the low measurement SNR regime where the energy-efficient design of optimized projections is most advantageous. In such cases, the optimized projection design departs significantly from random projections in terms of their incoherence with the representation basis. In fact, we find that the maximizing incoherence of projections with the representation basis is not necessarily optimal in the presence of additional prior information and finite measurement noise/error. We also apply the information-optimized projections to the compressive image formation problem for natural scenes, and the improved visual quality of reconstructed images with respect to random projections and other compressive measurement design affirms the overall effectiveness of the information-theoretic design framework.

  7. LOCATORS OPTIMIZATION FOR MEASURING FIXTURE DESIGN

    Institute of Scientific and Technical Information of China (English)

    Wang Jian; Zhou Jiangqi; Lin Zhongqin

    2004-01-01

    "N-2-1" principle is widely recognized in the fixture design for deformable sheet metal workpieces, where N, the locators on primary datum, is the key to sheet metal fixture design. However, little research is done on how to determine the positions and the number of N locators. In practice, the N locators are frequently designed from experience, which is often unsatisfactory for achieving the precision requirement in fixture design. A new method to lay out the N locators for measuring fixture of deformable sheet metal workpiece is presented, given the fixed number of N. Finite-element method is used to model and analysis the deformation of different locator layouts. A knowledge based genetic algorithm (KBGA) is applied to identify the optimum locator layout for measuring fixture design. An example of a door outer is used to verify the optimization approach.

  8. 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.

  9. Comparison of Central Corneal Thickness Measurements by Ultrasonic Pachymetry and Orbscan II Corneal Topography and Evaluation of Ultrasonic Pachymetry Repeatability

    Directory of Open Access Journals (Sweden)

    Semra Tiryaki Demir

    2014-08-01

    Full Text Available Objectives: Comparison of central corneal thickness (CCT measurements by ultrasonic pachymetry and Orbscan II corneal topography and evaluation of ultrasonic pachymetry repeatability for same observer. Materials and Methods: The study included 132, 82, and 80 eyes of 66 patients with primary open-angle glaucoma (POAG, 41 patients with ocular hypertension (OHT, and 40 controls, respectively. All subjects were subjected to routine ophthalmic examination. Orbscan II (Bausch&Lomb corneal topography and ultrasonic pachymetry (Nidek Ultrasonic Pachymetry UP-1000 were used for measurement of CCT. ANOVA (Turkey test was used for variable distribution, paired sample t-test was used for repeated measurements, and the analyses were done by SPSS 20.0. Results: Mean CCT was 558.9±37.2 µm by ultrasonic pachymetry and 553.4±37 µm by corneal topography. There was a significant difference between the two measurements (p0.05. CCT was 555±39.2 µm, 564.3±28.4 µm, and 559.7±41.5 µm by ultrasonic pachymetry in POAG, OHT, and control subjects, respectively; CCT was 550.3±38.3 µm, 558.5±28 µm, and 553.2±42.5 µm by Orbscan II corneal topography in POAG, OHT, and control subjects, respectively. There was a significant linear correlation between Orbscan II corneal topography and ultrasonic pachymetry in CCT measurements (r=0.975, p<0.0001. Repeatability of ultrasonic pachymetry for same observer was (ICC value 0.990. Conclusion: There is a significant correlation between Orbscan II corneal topography and ultrasonic pachymetry in CCT measurements. These two methods of measurements should not be substituted for each other, since ultrasonic pachymetry measures CCT greater than Orbscan II corneal topography. Repeatability of ultrasonic pachymetry for same observer is very high. (Turk J Ophthalmol 2014; 44: 263-7

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

    Science.gov (United States)

    Mauritz, Maria W.; Van Gaal, Betsie G. I.; Jongedijk, Ruud A.; Schoonhoven, Lisette; Nijhuis-van der Sanden, Maria W. G.; Goossens, Peter J. J.

    2016-01-01

    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 enhance the

  11. Using high-dynamic-range digital repeat photography to measure plant phenology in a subarctic mire.

    Science.gov (United States)

    Garnello, A.; Dye, D. G.; Bogle, R.; Vogel, J.; Saleska, S. R.; Crill, P. M.

    2015-12-01

    A novel Visual Imaging System (VIS) was designed and deployed in a subarctic mire (68° 20' N, 19° 03'E) aimed at cataloging plant biological changes (phenology) and analyzing seasonal color shifts in relation to micrometeorological data along the summer growing season: June-November, 2015. The VIS is designed as a tower-based, solar-powered, automated phenology camera (Phenocam) that collects red, green, blue (RGB) and near-infrared (NIR) landscape images in High Dynamic Range (HDR) with fully programmable temporal resolution. HDR composite images are made through combining a series of rapid-capture photos with incremental increases of exposure times and a fixed focus, minimizing the spatial and visual data lost from shadows or from the over-saturation of light. This visual record of ecosystem phenology stages (Phenophases) is being used to (1) investigate vegetation-dependent spectral indices; (2) establish a cross-year comparison record of Phenophase seasonality; (3) investigate meteorological-dependent vegetation Phenophases; (4) provide ground-truthing measurements that enhance broader spatial-scale remote sensing analyses of subarctic wetlands.

  12. 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

    2016-01-01

    Lower limb lymphedema is a dynamic condition in which tissue composition and volume measurements are affected. Various definitions of lower limb lymphedema exist but volume differences between the limbs are widely used. It is therefore necessary to have a readily available noninvasive measurement...... of agreement on the Bland-Altman plots. These results confirm DXA to be a highly repeatable method for volume and tissue composition measurements of the lower limb. In a population at risk of lymphedema, DXA offers a clinically readily available noninvasive method allowing multiple measurements of volume...... and tissue composition on a routine basis, important for diagnosing, monitoring, managing, and researching lymphedema....

  13. Repeatability and reproducibility of measurements of the suburethral tape location obtained in pelvic floor ultrasound performed with a transvaginal probe

    Directory of Open Access Journals (Sweden)

    Maria Magdalena Dresler

    2017-06-01

    Full Text Available Introduction: Implants used to treat patients with urogynecological conditions are well visible in US examination. The position of the suburethral tape (sling is determined in relation to the urethra or the pubic symphysis. Aim of the study: The study was aimed at assessing the accuracy of measurements determining suburethral tape location obtained in pelvic US examination performed with a transvaginal probe. Material and methods: The analysis covered the results of sonographic measurements obtained according to a standardized technique in women referred for urogynecological diagnostics. Data from a total of 68 patients were used to analyse the repeatability and reproducibility of results obtained on the same day. Results: The intraclass correlation coefficient for the repeatability and reproducibility of the sonographic measurements of suburethral tape location obtained with a transvaginal probe ranged from 0.6665 to 0.9911. The analysis of the measurements confirmed their consistency to be excellent or good. Conclusions: Excellent and good repeatability and reproducibility of the measurements of the suburethral tape location obtained in a pelvic ultrasound performed with a transvaginal probe confirm the test’s validity and usefulness for clinical and academic purposes.

  14. Measuring and Communicating Emotions Through Game Design

    DEFF Research Database (Denmark)

    Knutz, Eva; Markussen, Thomas

    2010-01-01

    This paper explores how emotion research may inform the design of a playful interactive tool for emotion measurement and communication, called Child Patient Game (CPgame) that has been developed for paediatric patients at a Danish hospital. The CPgame differs from other instruments in that it uses...... digital narrative and game play as means for self-report. In so doing it integrate play, communication and measurement in one and the same device. First it gives 4-6 year old hospitalized children an opportunity to learn how to cope with their own emotional reactions to medical treatment through game play....... Second, healthcare personal and design researchers can use the CPgame to gain knowledge of this patient group as it measures the children’s subjective feelings about their emotions. In the paper we discuss how key theoretical concepts of emotion may help the designer to identify the basic building blocks...

  15. Comparison of intraclass correlation coefficient estimates and standard errors between using cross-sectional and repeated measurement data: the Safety Check cluster randomized trial.

    Science.gov (United States)

    Ip, Edward H; Wasserman, Richard; Barkin, Shari

    2011-03-01

    Designing cluster randomized trials in clinical studies often requires accurate estimates of intraclass correlation, which quantifies the strength of correlation between units, such as participants, within a cluster, such as a practice. Published ICC estimates, even when available, often suffer from the problem of wide confidence intervals. Using data from a national, randomized, controlled study concerning violence prevention for children--the Safety Check--we compare the ICC values derived from two approaches only baseline data and using both baseline and follow-up data. Using a variance component decomposition approach, the latter method allows flexibility in handling complex data sets. For example, it allows for shifts in the outcome variable over time and for an unbalanced cluster design. Furthermore, we evaluate the large-sample formula for ICC estimates and standard errors using the bootstrap method. Our findings suggest that ICC estimates range from 0.012 to 0.11 for providers within practice and range from 0.018 to 0.11 for families within provider. The estimates derived from the baseline-only and repeated-measurements approaches agree quite well except in cases in which variation over repeated measurements is large. The reductions in the widths of ICC confidence limits from using repeated measurement over baseline only are, respectively, 62% and 42% at the practice and provider levels. The contribution of this paper therefore includes two elements, which are a methodology for improving the accuracy of ICC, and the reporting of such quantities for pediatric and other researchers who are interested in designing clustered randomized trials similar to the current study.

  16. Compressor Part I: Measurement and Design Modeling

    Directory of Open Access Journals (Sweden)

    Thomas W. Bein

    1999-01-01

    method used to design the 125-ton compressor is first reviewed and some related performance curves are predicted based on a quasi-3D method. In addition to an overall performance measurement, a series of instruments were installed on the compressor to identify where the measured performance differs from the predicted performance. The measurement techniques for providing the diagnostic flow parameters are also described briefly. Part II of this paper provides predictions of flow details in the areas of the compressor where there were differences between the measured and predicted performance.

  17. 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

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

    Science.gov (United States)

    Hanumunthadu, Daren; Ilginis, Tomas; Restori, Marie; Sagoo, Mandeep S; Tufail, Adnan; Balaggan, Kamaljit S; Patel, Praveen J

    2017-05-01

    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). 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. 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). The repeatability this subfield, expressed as a percentage of the mean central macular subfield thickness, was 23.2%. The percentage repeatability of the other macular subfields ranged from 13.2% to 28.7%. The intrasession coefficient of repeatability of choroidal thickness of the central macular subfield was 57.2 μm with a mean choroidal thickness (±SD) of 181 μm (±15.8 μm). This study suggests that a change >23.2% of retinal thickness and 57.2 μm choroidal thickness in the central macular subfield is required to distinguish true clinical change from measurement variability when using the DRI OCT-1 device to manage patients with nAMD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  19. Measurement Design for Detecting Sparse Signals

    CERN Document Server

    Zahedi, Ramin; Chong, Edwin K P

    2011-01-01

    We consider the problem of testing for the presence (or detection) of an unknown sparse signal in additive white noise. Given a fixed measurement budget, much smaller than the dimension of the signal, we consider the general problem of designing compressive measurements to maximize the measurement signal-to-noise ratio (SNR), as increasing SNR improves the detection performance in a large class of detectors. We use a lexicographic optimization approach, where the optimal measurement design for sparsity level $k$ is sought only among the set of measurement matrices that satisfy the optimality conditions for sparsity level k-1. We consider optimizing two different SNR criteria, namely a worst-case SNR measure, over all possible realizations of a k-sparse signal, and an average SNR measure with respect to a uniform distribution on the locations of the up to k nonzero entries in the signal. We establish connections between these two criteria and certain classes of tight frames. We constrain our measurement matric...

  20. Psychological impact and recovery after involvement in a patient safety incident: a repeated measures analysis

    Science.gov (United States)

    Van Gerven, Eva; Bruyneel, Luk; Panella, Massimiliano; Euwema, Martin; Sermeus, Walter; Vanhaecht, Kris

    2016-01-01

    Objective To examine individual, situational and organisational aspects that influence psychological impact and recovery of a patient safety incident on physicians, nurses and midwives. Design Cross-sectional, retrospective surveys of physicians, midwives and nurses. Setting 33 Belgian hospitals. Participants 913 clinicians (186 physicians, 682 nurses, 45 midwives) involved in a patient safety incident. Main outcome measures The Impact of Event Scale was used to retrospectively measure psychological impact of the safety incident at the time of the event and compare it with psychological impact at the time of the survey. Results Individual, situational as well as organisational aspects influenced psychological impact and recovery of a patient safety incident. Psychological impact is higher when the degree of harm for the patient is more severe, when healthcare professionals feel responsible for the incident and among female healthcare professionals. Impact of degree of harm differed across clinicians. Psychological impact is lower among more optimistic professionals. Overall, impact decreased significantly over time. This effect was more pronounced for women and for those who feel responsible for the incident. The longer ago the incident took place, the stronger impact had decreased. Also, higher psychological impact is related with the use of a more active coping and planning coping strategy, and is unrelated to support seeking coping strategies. Rendered support and a support culture reduce psychological impact, whereas a blame culture increases psychological impact. No associations were found with job experience and resilience of the health professional, the presence of a second victim support team or guideline and working in a learning culture. Conclusions Healthcare organisations should anticipate on providing their staff appropriate and timely support structures that are tailored to the healthcare professional involved in the incident and to the specific

  1. Comparison of Central Corneal Thickness Measurements by Ultrasonic Pachymetry and Orbscan II Corneal Topography and Evaluation of Ultrasonic Pachymetry Repeatability

    OpenAIRE

    Semra Tiryaki Demir; Mahmut Odabaşı; Mehmet Ersin Oba; Ayşe Burcu Dirim; Efe Can; Orhan Kara

    2014-01-01

    Objectives: Comparison of central corneal thickness (CCT) measurements by ultrasonic pachymetry and Orbscan II corneal topography and evaluation of ultrasonic pachymetry repeatability for same observer. Materials and Methods: The study included 132, 82, and 80 eyes of 66 patients with primary open-angle glaucoma (POAG), 41 patients with ocular hypertension (OHT), and 40 controls, respectively. All subjects were subjected to routine ophthalmic examination. Orbscan II (Bausch&Lomb) ...

  2. Incomplete quality of life data in lung transplant research: comparing cross sectional, repeated measures ANOVA, and multi-level analysis

    Directory of Open Access Journals (Sweden)

    van der Bij Wim

    2005-09-01

    Full Text Available Abstract Background In longitudinal studies on Health Related Quality of Life (HRQL it frequently occurs that patients have one or more missing forms, which may cause bias, and reduce the sample size. Aims of the present study were to address the problem of missing data in the field of lung transplantation (LgTX and HRQL, to compare results obtained with different methods of analysis, and to show the value of each type of statistical method used to summarize data. Methods Results from cross-sectional analysis, repeated measures on complete cases (ANOVA, and a multi-level analysis were compared. The scores on the dimension 'energy' of the Nottingham Health Profile (NHP after transplantation were used to illustrate the differences between methods. Results Compared to repeated measures ANOVA, the cross-sectional and multi-level analysis included more patients, and allowed for a longer period of follow-up. In contrast to the cross sectional analyses, in the complete case analysis, and the multi-level analysis, the correlation between different time points was taken into account. Patterns over time of the three methods were comparable. In general, results from repeated measures ANOVA showed the most favorable energy scores, and results from the multi-level analysis the least favorable. Due to the separate subgroups per time point in the cross-sectional analysis, and the relatively small number of patients in the repeated measures ANOVA, inclusion of predictors was only possible in the multi-level analysis. Conclusion Results obtained with the various methods of analysis differed, indicating some reduction of bias took place. Multi-level analysis is a useful approach to study changes over time in a data set where missing data, to reduce bias, make efficient use of available data, and to include predictors, in studies concerning the effects of LgTX on HRQL.

  3. 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.

  4. Persistent repeated measurements by magnetic resonance spectroscopy demonstrate minimal hepatic encephalopathy: a case report.

    Science.gov (United States)

    Scheau, C; Popa, G A; Ghergus, A E; Preda, E M; Capsa, R A; Lupescu, I G

    2013-09-15

    Minimal Hepatic Encephalopathy (MHE), previously referred to as infraclinical or subclinical is a precursor in the development of clinical hepatic encephalopathy (HE). The demonstration of MHE is done through neuropsychological testing in the absence of clinical evidence of HE, patients showing only a mild cognitive impairment. Neuropsychological tests employed consist of Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and portosystemic encephalopathy (PSE) test score. Unfortunately, there are numerous occasions when the tests prove irrelevant: in the situation of inexperienced investigators, the patient's poor education, vision problems or concurring central nervous system disease, all of which may delay or deviate from the correct diagnosis.

  5. A Finite Mixture of Nonlinear Random Coefficient Models for Continuous Repeated Measures Data.

    Science.gov (United States)

    Kohli, Nidhi; Harring, Jeffrey R; Zopluoglu, Cengiz

    2016-09-01

    Nonlinear random coefficient models (NRCMs) for continuous longitudinal data are often used for examining individual behaviors that display nonlinear patterns of development (or growth) over time in measured variables. As an extension of this model, this study considers the finite mixture of NRCMs that combine features of NRCMs with the idea of finite mixture (or latent class) models. The efficacy of this model is that it allows the integration of intrinsically nonlinear functions where the data come from a mixture of two or more unobserved subpopulations, thus allowing the simultaneous investigation of intra-individual (within-person) variability, inter-individual (between-person) variability, and subpopulation heterogeneity. Effectiveness of this model to work under real data analytic conditions was examined by executing a Monte Carlo simulation study. The simulation study was carried out using an R routine specifically developed for the purpose of this study. The R routine used maximum likelihood with the expectation-maximization algorithm. The design of the study mimicked the output obtained from running a two-class mixture model on task completion data.

  6. Design of a Dual-Band On-Body Antenna for a Wireless Body Area Network Repeater System

    Directory of Open Access Journals (Sweden)

    Kyeol Kwon

    2012-01-01

    Full Text Available A dual-band on-body antenna for a wireless body area network repeater system is proposed. The designed dual-band antenna has the maximum radiation directed toward the inside of the human body in the medical implantable communication service (MICS band in order to collect vital information from the human body and directed toward the outside in the industrial, scientific, and medical (ISM band to transmit that information to a monitoring system. In addition, the return loss property of the antenna is insensitive to human body effects by utilizing the epsilon negative zeroth-order resonance property.

  7. Repeated measures of inflammation and oxidative stress biomarkers in preeclamptic and normotensive pregnancies.

    Science.gov (United States)

    Ferguson, Kelly K; Meeker, John D; McElrath, Thomas F; Mukherjee, Bhramar; Cantonwine, David E

    2017-05-01

    Preeclampsia is a prevalent and enigmatic disease, in part characterized by poor remodeling of the spiral arteries. However, preeclampsia does not always clinically present when remodeling has failed to occur. Hypotheses surrounding the "second hit" that is necessary for the clinical presentation of the disease focus on maternal inflammation and oxidative stress. Yet, the studies to date that have investigated these factors have used cross-sectional study designs or small study populations. In the present study, we sought to explore longitudinal trajectories, beginning early in gestation, of a panel of inflammation and oxidative stress markers in women who went on to have preeclamptic or normotensive pregnancies. We examined 441 subjects from the ongoing LIFECODES prospective birth cohort, which included 50 mothers who experienced preeclampsia and 391 mothers with normotensive pregnancies. Participants provided urine and plasma samples at 4 time points during gestation (median, 10, 18, 26, and 35 weeks) that were analyzed for a panel of oxidative stress and inflammation markers. Oxidative stress biomarkers included 8-isoprostane and 8-hydroxydeoxyguanosine. Inflammation biomarkers included C-reactive protein, the cytokines interleukin-1β, -6, and -10, and tumor necrosis factor-α. We created Cox proportional hazard models to calculate hazard ratios based on time of preeclampsia diagnosis in association with biomarker concentrations at each of the 4 study visits. In adjusted models, hazard ratios of preeclampsia were significantly (Pinflammation biomarkers that were measured at visit 2 (median, 18 weeks; hazard ratios, 1.31-1.83, in association with an interquartile range increase in biomarker). Hazard ratios at this time point were the most elevated for C-reactive protein, for interleukin-1β, -6, and -10, and for the oxidative stress biomarker 8-isoprostane (hazard ratio, 1.68; 95% confidence interval, 1.14-2.48) compared to other time points. Hazard ratios for

  8. Accuracy and repeatability of direct ciliary sulcus diameter measurements by full-scale 50-megahertz ultrasound biomicroscopy

    Institute of Scientific and Technical Information of China (English)

    LI De-jiao; WANG Ning-li; CHEN Shu; LI Shu-ning; MU Da-peng; WANG Tao

    2009-01-01

    Background Phakic intraocular lens (pIOL) implantation has been a popular means for the treatment of high ametropia. Measurements of ciliary sulcus diameter is important for pIOL size determining. But till now, no perfect system can directly measure it. The present study was to evaluate the accuracy, repeatability and reproducibility of direct sulcus diameter measurements obtained by a full-scale 50-megahertz (MHz) ultrasound biomicroscopy (UBM).Methods A fresh cadaver human eye with a scale marker inserted through the posterior chamber plane from 3 o'clock to 9 o'clock meridian and 30 randomly selected eyes from 30 normal subjects were scanned by full-scale 50-MHz UBM in horizontal meridional scan plane. The distance between the scales and the whole length of the marker inside the cadaver eye were measured by the same observer using the "built-in" measurement tools and the indicating error of instrument was calculated. Reproducibility of the measurement was evaluated in 30 eyes by 2 operators using Blander and Altman plot test. Repeatability was evaluated from 10 successive eyes randomly selected from the 30 eyes by one operator.Results On a scale of 1 mm, the greatest indicating error was 40 μm; the mean largest indicating error of 1 mm scale from the 10 images was (26±14) μm; on a scale of 11 mm, the greatest indicating error was 70 μo; the error rate was 0.64%. The mean length of the needle inside the eye of the 10 images was 11.05 mm, with the mean indicating error of 47 μm, the average error rate was 0.43%. For ciliary sulcus diameter measurements in vivo, the coefficient of variation was 0.38%; the coefficients of repeatability for intra-observer and inter-observer measurements were 1.99% and 2.55%, respectively. The limits of agreement for intra-observer and inter-observer measurement were-0.41 mm to 0.48 mm and -0.59 mm to 0.58 ram, respectively.Conclusion The full-scale 50-MHz UBM can be a high accuracy and good repeatability means for direct

  9. Design of hybrid automatic repeat request (HARQ)for TDD-OFDM system

    Institute of Scientific and Technical Information of China (English)

    Wen Na; Zhang Ping

    2008-01-01

    Reliability-based hybrid automatic repeat request (HARQ) (RB-HARQ) is a recently developed form of incremental-redundancy ARQ.It achieves good performance whereas large retransmission request packets should be fed back.In this paper, in order to reduce the number of the fed back bits, we propose a HARQ scheme applied in time duplex division orthogonal frequency division multiplexing (TDDOFDM) system over the slow fading channel which is named channel-based HARQ (CB-HARQ).Because one bit which meets deep fading is always with small value of log likelihood ratio (LLR) during the process of decoding of LDPC code, the bits transmitted on the carrier with deep fading are retransmitted.At the receiver, the decoder will compute the locations of retransmission bits according to the channel fading values which are gotten by utilizing the feature of channel symmetry in TDD mode.So the indices of retransmission bits are avoided to be transmitted.Simulation results show that this method achieves better BER performance and requires much smaller request packets in feedback link.

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

    DEFF Research Database (Denmark)

    Miles, James Edward; Jensen, Bente Rona; Kirpensteijn, Jolle

    2013-01-01

    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 limbs. An...... and applied criteria. The TT-TG offset distance has potential as an objective assessment of alignment of the distal portion of the quadriceps mechanism; its use as an aid in case selection for corrective femoral osteotomy among dogs with medial patellar luxation warrants investigation....

  11. Case study: videogame distraction reduces behavioral distress in a preschool-aged child undergoing repeated burn dressing changes: a single-subject design

    National Research Council Canada - National Science Library

    Sil, Soumitri; Dahlquist, Lynnda M; Burns, Andrew J

    2013-01-01

    This single-subject design study evaluated the feasibility and efficacy of passive and interactive videogame distraction on behavioral distress for a preschool-aged child receiving repeated burn dressing changes...

  12. 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.

  13. Information measures in nonlinear experimental design

    Science.gov (United States)

    Niple, E.; Shaw, J. H.

    1980-01-01

    Some different approaches to the problem of designing experiments which estimate the parameters of nonlinear models are discussed. The assumption in these approaches that the information in a set of data can be represented by a scalar is criticized, and the nonscalar discrimination information is proposed as the proper measure to use. The two-step decay example in Box and Lucas (1959) is used to illustrate the main points of the discussion.

  14. 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.

  15. A Description of Quasar Variability Measured Using Repeated SDSS and POSS Imaging

    CERN Document Server

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

    2011-01-01

    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 34,727 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 1000A to 6000A. 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 time scale and an asymptotic variabilit...

  16. Ocular microtremor measurement system: design and performance.

    Science.gov (United States)

    Sheahan, N F; Coakley, D; Hegarty, F; Bolger, C; Malone, J

    1993-05-01

    The frequency of ocular microtremor (OMT) is related to the functional status of the brain stem, and thus OMT may be useful in the diagnosis and management of brain stem disorders. The paper discusses the design of an OMT measurement system and reports quantitative specifications for three portable systems. All systems use a piezo-electric element as the transducer, which measures the displacement of the sclera during eye rotations. The systems differ in the manner in which the signal is recorded. All systems can detect eye movements corresponding to displacements of the sclera ranging from 12 to over 3000 nm. The frequency responses of all systems are flat (< 2 dB deviation from peak response) between 20 and 150 Hz. The phase response shows deviations (< pi) at the extremes of this range, but qualitative comparison of input and measured signals demonstrates that phase distortion is not excessive. Thus all systems are acceptable for clinical studies involving OMT.

  17. Estimation of spatial patterns of urban air pollution over a 4-week period from repeated 5-min measurements

    Science.gov (United States)

    Gillespie, Jonathan; Masey, Nicola; Heal, Mathew R.; Hamilton, Scott; Beverland, Iain J.

    2017-02-01

    Determination of intra-urban spatial variations in air pollutant concentrations for exposure assessment requires substantial time and monitoring equipment. The objective of this study was to establish if short-duration measurements of air pollutants can be used to estimate longer-term pollutant concentrations. We compared 5-min measurements of black carbon (BC) and particle number (PN) concentrations made once per week on 5 occasions, with 4 consecutive 1-week average nitrogen dioxide (NO2) concentrations at 18 locations at a range of distances from busy roads in Glasgow, UK. 5-min BC and PN measurements (averaged over the two 5-min periods at the start and end of a week) explained 40-80%, and 7-64% respectively, of spatial variation in the intervening 1-week NO2 concentrations for individual weeks. Adjustment for variations in background concentrations increased the percentage of explained variation in the bivariate relationship between the full set of NO2 and BC measurements over the 4-week period from 28% to 50% prior to averaging of repeat measurements. The averages of five 5-min BC and PN measurements made over 5 weeks explained 75% and 33% respectively of the variation in average 1-week NO2 concentrations over the same period. The relatively high explained variation observed between BC and NO2 measured on different time scales suggests that, with appropriate steps to correct or average out temporal variations, repeated short-term measurements can be used to provide useful information on longer-term spatial patterns for these traffic-related pollutants.

  18. Variation in repeated mouth-opening measurements in head and neck cancer patients with and without trismus.

    Science.gov (United States)

    Jager-Wittenaar, H; Dijkstra, P U; Vissink, A; van Oort, R P; Roodenburg, J L N

    2009-01-01

    Trismus after head and neck cancer treatment may severely limit mandibular functioning. Interventions aimed at reducing trismus can only be evaluated when the amount of variation associated with these measurements is known. The aim of this study was to analyse the variation in mouth-opening measurements in patients treated for head and neck cancer, with and without trismus. Maximal mouth opening was measured in 120 patients in two sessions of three repeated measurements by one observer. To analyse the influence of interobserver variation on mouth-opening measurements a subgroup of 30 patients was measured by a second observer. The standard deviation of the six measurements per patient was used as the variation in measurements of maximal mouth opening. No significant difference was found in maximal mouth opening in patients with (n=33) or without (n=87) trismus. The interobserver intraclass correlation coefficient (ICC) was 0.98. Intraobserver ICC and intersession ICC reliabilities both were 0.99. The variation in the mean values of the three measurements was only slightly smaller than the variation of the single measurements. Variation in maximal mouth opening in patients with trismus does not differ from variation in maximal mouth opening in patients without trismus. Interobserver variation is limited.

  19. Placebo non-response measure in sequential parallel comparison design studies.

    Science.gov (United States)

    Rybin, Denis; Doros, Gheorghe; Pencina, Michael J; Fava, Maurizio

    2015-07-10

    The Sequential Parallel Comparison Design (SPCD) is one of the novel approaches addressing placebo response. The analysis of SPCD data typically classifies subjects as 'placebo responders' or 'placebo non-responders'. Most current methods employed for analysis of SPCD data utilize only a part of the data collected during the trial. A repeated measures model was proposed for analysis of continuous outcomes that permitted the inclusion of information from all subjects into the treatment effect estimation. We describe here a new approach using a weighted repeated measures model that further improves the utilization of data collected during the trial, allowing the incorporation of information that is relevant to the placebo response, and dealing with the problem of possible misclassification of subjects. Our simulations show that when compared to the unweighted repeated measures model method, our approach performs as well or, under certain conditions, better, in preserving the type I error, achieving adequate power and minimizing the mean squared error.

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

    Energy Technology Data Exchange (ETDEWEB)

    MacLeod, Chelsea L.; Ivezic, Zeljko; Becker, Andrew C.; Anderson, Scott F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Sesar, Branimir [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); De Vries, Wim [Department of Physics, University of California, One Shields Ave, Davis, CA 95616 (United States); Kochanek, Christopher S. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Kelly, Brandon C. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Lupton, Robert H. [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544 (United States); Hall, Patrick B. [Department of Physics and Astronomy, York University, Toronto, ON M3J 1P3 (Canada); Richards, Gordon T. [Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

    2012-07-10

    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 {approx}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 A to 6000 A. 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 {approx}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.

  1. Repeatability of Cone Spacing Measures in Eyes With Inherited Retinal Degenerations

    National Research Council Canada - National Science Library

    Zayit-Soudry, Shiri; Sippl-Swezey, Nicolas; Porco, Travis C; Lynch, Stephanie K; Syed, Reema; Ratnam, Kavitha; Menghini, Moreno; Roorda, Austin J; Duncan, Jacque L

    2015-01-01

    ...)-derived cone spacing measures in eyes with inherited retinal degenerations (IRD) and in normal eyes. Twenty IRD patients and 10 visually normal subjects underwent AOSLO imaging at two visits separated by no more than 1 month...

  2. Repeatability of Choroidal Thickness Measurements on Enhanced Depth Imaging Optical Coherence Tomography Using Different Posterior Boundaries.

    Science.gov (United States)

    Vuong, Vivian S; Moisseiev, Elad; Cunefare, David; Farsiu, Sina; Moshiri, Ala; Yiu, Glenn

    2016-09-01

    To assess the reliability of manual choroidal thickness measurements by comparing different posterior boundary definitions of the choroidal-scleral junction on enhanced depth imaging optical coherence tomography (EDI-OCT). Reliability analysis. Two graders marked the choroidal-scleral junction with segmentation software using different posterior boundaries: (1) the outer border of the choroidal vessel lumen, (2) the outer border of the choroid stroma, and (3) the inner border of the sclera, to measure the vascular choroidal thickness (VCT), stromal choroidal thickness (SCT), and total choroidal thickness (TCT), respectively. Measurements were taken at 0.5-mm intervals from 1.5 mm nasal to 1.5 mm temporal to the fovea, and averaged continuously across the central 3 mm of the macula. Intraclass correlation coefficient (ICC) and coefficient of reliability (CR) were compared to assess intergrader and intragrader reliability. Choroidal thickness measurements varied significantly with different posterior boundaries (P choroidal-scleral junction visibility was Choroidal thickness measurements are more reproducible when measured to the border of the choroid stroma (SCT) than the vascular lumen (VCT) or sclera (TCT). Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Design of Injection Mold for Repeater Panel%复读机面盖注塑模设计

    Institute of Scientific and Technical Information of China (English)

    蒋育华; 胡琪; 付鹏

    2012-01-01

    The structure characteristics of plastic part of repeater panel was analyzed. The design methods for combined molding parts and side core-pulling mechanism of the mold were expounded. The practical production proves that the actions of core-pulling and demoulding are steady and reliable, the pin-point gate can satisfy the appearance requirement of the plastic part, and the quality of the plastic part can meet the technical requirements.%分析了复读机面盖塑件的结构特点,阐述了该模具组合式成型零件及侧抽芯机构的设计方法.经生产实践证明:该模具的抽芯及脱模动作均平稳可靠,点浇口保证了塑件的外观要求,塑件质量可以满足技术要求.

  4. The Repeatability Assessment of Three-Dimensional Capsule-Intraocular Lens Complex Measurements by Means of High-Speed Swept-Source Optical Coherence Tomography

    Science.gov (United States)

    Chang, Pingjun; Li, Jin; Savini, Giacomo; Huang, Jinhai; Huang, Shenghai; Zhao, Yinying; Liao, Na; Lin, Lei; Yu, Xiaoyu; Zhao, Yun-e

    2015-01-01

    Purpose To rebuild the three-dimensional (3-D) model of the anterior segment by high-speed swept-source optical coherence tomography (SSOCT) and evaluate the repeatability of measurement for the parameters of capsule-intraocular lens (C-IOL) complex. Methods Twenty-two pseudophakic eyes from 22 patients were enrolled. Three continuous SSOCT measurements were performed in all eyes and the tomograms obtained were used for 3-D reconstruction. The output data were used to evaluate the measurement repeatability. The parameters included postoperative aqueous depth (PAD), the area and diameter of the anterior capsule opening (Area and D), IOL tilt (IOL-T), horizontal, vertical, and space decentration of the IOL, anterior capsule opening, and IOL-anterior capsule opening. Results PAD, IOL-T, Area, D, and all decentration measurements showed high repeatability. Repeated measure analysis showed there was no statistically significant difference among the three continuous measurements (all P > .05). Pearson correlation analysis showed high correlation between each pair of them (all r >0.90, P<0.001). ICCs were all more than 0.9 for all parameters. The 95% LoAs of all parameters were narrow for comparison of three measurements, which showed high repeatability for three measurements. Conclusion SSOCT is available to be a new method for the 3-D measurement of C-IOL complex after cataract surgery. This method presented high repeatability in measuring the parameters of the C-IOL complex. PMID:26600254

  5. Repeatability of measurements: Non-Hermitian observables and quantum Coriolis force

    Science.gov (United States)

    Gardas, Bartłomiej; Deffner, Sebastian; Saxena, Avadh

    2016-08-01

    A noncommuting measurement transfers, via the apparatus, information encoded in a system's state to the external "observer." Classical measurements determine properties of physical objects. In the quantum realm, the very same notion restricts the recording process to orthogonal states as only those are distinguishable by measurements. Therefore, even a possibility to describe physical reality by means of non-Hermitian operators should volens nolens be excluded as their eigenstates are not orthogonal. Here, we show that non-Hermitian operators with real spectra can be treated within the standard framework of quantum mechanics. Furthermore, we propose a quantum canonical transformation that maps Hermitian systems onto non-Hermitian ones. Similar to classical inertial forces this map is accompanied by an energetic cost, pinning the system on the unitary path.

  6. Mediation of the Relationship between Maternal Phthalate Exposure and Preterm Birth by Oxidative Stress with Repeated Measurements across Pregnancy.

    Science.gov (United States)

    Ferguson, Kelly K; Chen, Yin-Hsiu; VanderWeele, Tyler J; McElrath, Thomas F; Meeker, John D; Mukherjee, Bhramar

    2017-03-01

    Mediation analysis is useful for understanding mechanisms and has been used minimally in the study of the environment and disease. We examined mediation of the association between phthalate exposure during pregnancy and preterm birth by oxidative stress. This nested case-control study of preterm birth (n = 130 cases, 352 controls) included women who delivered in Boston, Massachusestts, from 2006 through 2008. Phthalate metabolites and 8-isoprostane, an oxidative stress biomarker, were measured in urine from three visits in pregnancy. We applied four counterfactual mediation methods: method 1, utilizing exposure and mediator averages; method 2, using averages but allowing for an exposure-mediator interaction; method 3, incorporating longitudinal measurements of the exposure and mediator; and method 4, using longitudinal measurements and allowing for an exposure-mediator interaction. We observed mediation of the associations between phthalate metabolites and all preterm birth by 8-isoprostane, with the greatest estimated proportion mediated observed for spontaneous preterm births specifically. Fully utilizing repeated measures of the exposure and mediator improved precision of indirect (i.e., mediated) effect estimates, and including an exposure-mediator interaction increased the estimated proportion mediated. For example, for mono(2-ethyl-carboxy-propyl) phthalate (MECPP), a metabolite of di(2-ethylhexyl) phthalate (DEHP), the percent of the total effect mediated by 8-isoprostane increased from 47% to 60% with inclusion of an exposure-mediator interaction term, in reference to a total adjusted odds ratio of 1.67 or 1.48, respectively. This demonstrates mediation of the phthalate-preterm birth relationship by oxidative stress, and the utility of complex regression models in capturing mediated associations when repeated measures of exposure and mediator are available and an exposure-mediator interaction may exist. Citation: Ferguson KK, Chen YH, VanderWeele TJ, Mc

  7. An L-band SAR for repeat pass deformation measurements on a UAV platform

    Science.gov (United States)

    Wheeler, Kevin; Hensley, Scott; Lou, Yunling

    2004-01-01

    We are proposing to develop a miniaturized polarimetric L-band synthetic aperture radar (SAR) for repeatpass differential interferometric measurements of deformation for rapidly deforming surfaces of geophysical interest such as volcanoes or earthquakes that is to be flown on a unmanned aerial vehicle (UAV or minimally piloted vehicle (MPV).

  8. Repeated measurements of P retention in ponies fed rations with various Ca:P ratios

    NARCIS (Netherlands)

    van Doorn, D A; Schaafstra, F J W C; Wouterse, H; Everts, H; Estepa, J C; Aguilera-Tejero, E; Beynen, A C

    2014-01-01

    This study addresses the question of whether feeding rations rich in P for a period of up to 42 d induces a positive P balance in adult ponies. Biochemical bone markers and parathyroid hormone (PTH; intact as well as whole PTH) were measured to obtain clues as to the effect of P loading on bone meta

  9. Repeated measures of urinary oxidative stress biomarkers during pregnancy and preterm birth.

    Science.gov (United States)

    Ferguson, Kelly K; McElrath, Thomas F; Chen, Yin-Hsiu; Loch-Caruso, Rita; Mukherjee, Bhramar; Meeker, John D

    2015-02-01

    The purpose of this study was to investigate oxidative stress as a mechanism of preterm birth in human subjects; we examined associations between urinary biomarkers of oxidative stress that were measured at multiple time points during pregnancy and preterm birth. This nested case-control study included 130 mothers who delivered preterm and 352 mothers who delivered term who were originally recruited as part of an ongoing prospective birth cohort at Brigham and Women's Hospital. Two biomarkers that included 8-hydroxydeoxyguanosine (8-OHdG) and 8-isoprostane were measured in urine samples that were collected at up to 4 time points (median 10, 18, 26, and 35 weeks) during gestation. Urinary concentrations of 8-isoprostane and 8-OHdG decreased and increased, respectively, as pregnancy progressed. Average levels of 8-isoprostane across pregnancy were associated with increased odds of spontaneous preterm birth (adjusted odds ratio, 6.25; 95% confidence interval, 2.86-13.7), and associations were strongest with levels measured later in pregnancy. Average levels of 8-OHdG were protective against overall preterm birth (adjusted odds ratio, 0.19; 95% confidence interval, 0.10-0.34), and there were no apparent differences in the protective effect in cases of spontaneous preterm birth compared with cases of placental origin. Odds ratios for overall preterm birth were more protective in association with urinary 8-OHdG concentrations that were measured early in pregnancy. Maternal oxidative stress may be an important contributor to preterm birth, regardless of subtype and timing of exposure during pregnancy. The 2 biomarkers that were measured in the present study had opposite associations with preterm birth; an improved understanding of what each represents may help to identify more precisely important mechanisms in the pathway to preterm birth. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Design of computerized unbalance measuring system

    Energy Technology Data Exchange (ETDEWEB)

    Karunakara, K.; Nambudiri, P.V.V.; Aradhya, S.; Kumar, E.M.; Channakeshava [Central Power Research Inst., Bangalore (India)

    1995-12-31

    In complex network, the connected loads may be of single phase or three phase. Increased trend of traction loads, Arc furnace load and thyristor devices necessitates check for voltage quality. Harmonics, flicker and unbalance are some of the factors influencing the voltage quality. Evaluation of voltage quality and applying correction, if required, are to be made depending upon the situation prevailing in the system. Under certain load conditions like arc furnace, traction and thyristor devices, the unbalance factor may vary every few cycles and for the unbalance correction, devices like static Var compensator (SVC) have to be used. These correcting devices have some time lag to effect corrections, thus measurement based on short time information will not give the true picture. To avoid erroneous conclusions from the short term data, an instrument based on an integrated value over fairly long duration was designed and fabricated by CPRI. This paper discusses about the design and calibration of the instrument and presents typical measured data on an electrical system by using this instrument.

  11. New Gear Transmission Error Measurement System Designed

    Science.gov (United States)

    Oswald, Fred B.

    2001-01-01

    The prime source of vibration and noise in a gear system is the transmission error between the meshing gears. Transmission error is caused by manufacturing inaccuracy, mounting errors, and elastic deflections under load. Gear designers often attempt to compensate for transmission error by modifying gear teeth. This is done traditionally by a rough "rule of thumb" or more recently under the guidance of an analytical code. In order for a designer to have confidence in a code, the code must be validated through experiment. NASA Glenn Research Center contracted with the Design Unit of the University of Newcastle in England for a system to measure the transmission error of spur and helical test gears in the NASA Gear Noise Rig. The new system measures transmission error optically by means of light beams directed by lenses and prisms through gratings mounted on the gear shafts. The amount of light that passes through both gratings is directly proportional to the transmission error of the gears. A photodetector circuit converts the light to an analog electrical signal. To increase accuracy and reduce "noise" due to transverse vibration, there are parallel light paths at the top and bottom of the gears. The two signals are subtracted via differential amplifiers in the electronics package. The output of the system is 40 mV/mm, giving a resolution in the time domain of better than 0.1 mm, and discrimination in the frequency domain of better than 0.01 mm. The new system will be used to validate gear analytical codes and to investigate mechanisms that produce vibration and noise in parallel axis gears.

  12. Design of the new rigid endoscope distortion measurement system

    Science.gov (United States)

    Zhai, Xiaohao; Liu, Xiaohua; Liu, Ming; Hui, Mei; Dong, Liquan; Zhao, Yuejin; Wang, Yakun; Li, Yonghui; Zhou, Peng

    2015-08-01

    Endoscopic imaging quality affects industrial safety and medical security. Rigid endoscope distortion is of great signification as one of optical parameters to evaluate the imaging quality. This paper introduces a new method of rigid endoscope distortion measurement, which is different from the common methods with low accuracy and fussy operation. It contains a Liquid Crystal Display (LCD) to display the target, a CCD to obtain the images with distortion, and a computer to process the images. The LCD is employed instead of common white screen. The autonomous control system of LCD makes it showing the test target designed for distortion, and its parameter is known. LCD control system can change the test target to satisfy the different demand for accuracy, which avoids replacing target frequently. The test system also contains a CCD to acquire images in the exit pupil position of rigid endoscope. Rigid endoscope distortion is regarded as centrosymmetric, and the MATLAB software automatically measures it by processing the images from CCD. The MATLAB software compares target images with that without distortion on LCD and calculates the results. Relative distortion is obtained at different field of view (FOV) radius. The computer plots the curve of relative distortion, abscissa means radius of FOV, ordinate means relative distortion. The industry standard shows that, the distortion at 70% field of view is pointed on the curve, which can be taken as an evaluation standard. This new measuring method achieves advantages of high precision, high degree of intelligence, excellent repeatability and gets calculation results quickly.

  13. A Statistical Approach Designed for Finding Mathematically Defined Repeats in Shotgun Data and Determining the Length Distribution of Clone—Inserts

    Institute of Scientific and Technical Information of China (English)

    LanZhong; KunlinZhang; XiangangHuang; PeixiangNi; YujunHan; KaiWang; JunWang; SonggangLi

    2003-01-01

    The large amount of repeats,especially high copy repeats,in the genomes of higher animals and plants makes whole genome assembly(WGA)quite difficult.In order to solve this problem,we tried to identify repeats and mask them prior to assembly even at the stage of genome survey.It is known that repeats of different copy number have different probabilities of appearance in shotgun data,so based on this principle,we constructed a statistical model and inferred criteria for mathematically defined repeats(MDRs)at different shotgun coverages.According to these criteria,we developed software MDRmasker to identify and mask MDRs in shotgun data.With repeats masked prior to assembly,the speed of as sembly was increased with lower error probability.In addition,clone-insert size affects the accuracy of repeat assembly and scaffold construction.We also designed length distribution of clone-inserts using our model.In our simulated genomes of human and rice,the length distribution of repeats in different,so their optimal length distributions of clone-inserts were not the same.Thus with optimal length distribution of clone-inserts,a given genome could be assembled better at lower coverage.

  14. A Statistical Approach Designed for Finding Mathematically De fined Repeats in Shotgun Data and Determining the Length Distri bution of Clone-Inserts

    Institute of Scientific and Technical Information of China (English)

    Lan Zhong; Kunlin Zhang; Xiangang Huang; Peixiang Ni; Yujun Han; Kai Wang; Jun Wang; Songgang Li

    2003-01-01

    The large amount of repeats, especially high copy repeats, in the genomes of higher animals and plants makes whole genome assembly (WGA) quite difficult. In order to solve this problem, we tried to identify repeats and mask them prior to assembly even at the stage of genome survey. It is known that repeats of different copy number have different probabilities of appearance in shotgun data, so based on this principle, we constructed a statistical model and inferred criteria for mathematically defined repeats (MDRs) at different shotgun coverages. According to these criteria, we developed software MDRmasker to identify and mask MDRs in shotgun data. With repeats masked prior to assembly, the speed of assembly was increased with lower error probability. In addition, clone-insert size affects the accuracy of repeat assembly and scaffold construction. We also designed length distribution of clone-inserts using our model. In our simulated genomes of human and rice, the length distribution of repeats is different, so their optimal length distributions of clone-inserts were not the same. Thus with optimal length distribution of clone-inserts, a given genome could be assembled better at lower coverage.

  15. 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.

  16. Extended fluctuation theorems for repeated measurements and feedback within Hamiltonian framework

    Energy Technology Data Exchange (ETDEWEB)

    Lahiri, Sourabh, E-mail: sourabhlahiri@gmail.com [Laboratoire de Physico-Chimie Théorique, ESPCI, 10 rue Vauquelin, F-75231 Paris (France); Jayannavar, A.M. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India)

    2016-04-29

    We derive the extended fluctuation theorems in presence of multiple measurements and feedback, when the system is governed by Hamiltonian dynamics. We use only the forward phase space trajectories in the derivation. However, to obtain an expression for the efficacy parameter, we must necessarily use the notion of reverse trajectory. Our results show that the correction term appearing in the exponent of the extended fluctuation theorems is non-unique, whereas the physical meaning of the efficacy parameter is unique. - Highlights: • Extended Fluctuation Theorems under multiple measurements and feedback have been derived using Hamiltonian dynamics. • We prove the theorems without using the notion of reverse trajectory. • We show that the correction terms are not unique. • The efficacy parameter is shown to have a unique physical meaning.

  17. Composite tube and plate manufacturing repeatability as determined by precision measurements of thermal strain

    Science.gov (United States)

    Riddle, Lenn A.; Tucker, James R.; Bluth, A. Marcel

    2013-09-01

    Composite materials often carry the reputation of demonstrating high variability in critical material properties. The JWST telescope metering structure is fabricated of several thousand separate composite piece parts. The stringent dimensional stability requirements on the metering structure require the critical thermal strain response of every composite piece be verified either at the billet or piece part level. JWST is a unique composite space structure in that it has required the manufacturing of several hundred composite billets that cover many lots of prepreg and many years of fabrication. The flight billet thermal expansion acceptance criteria limits the coefficient of thermal expansion (CTE) to a tolerance ranging between +/-0.014 ppm/K to +/-0.04 ppm/K around a prescribed nominal when measured from 293 K down to 40 K. The different tolerance values represent different material forms including flat plates and different tube cross-section dimensions. A precision measurement facility was developed that could measure at the required accuracy and at a pace that supported the composite part fabrication rate. The test method and facility is discussed and the results of a statistical process analysis of the flight composite billets are surveyed.

  18. Are exhaled nitric oxide measurements using the portable NIOX MINO repeatable?

    Directory of Open Access Journals (Sweden)

    Raza Abid

    2010-04-01

    Full Text Available Abstract Background Exhaled nitric oxide is a non-invasive marker of airway inflammation and a portable analyser, the NIOX MINO (Aerocrine AB, Solna, Sweden, is now available. This study aimed to assess the reproducibility of the NIOX MINO measurements across age, sex and lung function for both absolute and categorical exhaled nitric oxide values in two distinct groups of children and teenagers. Methods Paired exhaled nitric oxide readings were obtained from 494 teenagers, aged 16-18 years, enrolled in an unselected birth cohort and 65 young people, aged 6-17 years, with asthma enrolled in an interventional asthma management study. Results The birth cohort participants showed a high degree of variability between first and second exhaled nitric oxide readings (mean intra-participant difference 1.37 ppb, 95% limits of agreement -7.61 to 10.34 ppb, although there was very close agreement when values were categorised as low, normal, intermediate or high (kappa = 0.907, p Conclusions The reproducibility of exhaled nitric oxide is poor for absolute values but acceptable when values are categorised as low, normal, intermediate or high in children and teenagers. One measurement is therefore sufficient when using categorical exhaled nitric oxide values to direct asthma management but a mean of at least two measurements is required for absolute values.

  19. Reliability of plasma lipopolysaccharide-binding protein (LBP) from repeated measures in healthy adults.

    Science.gov (United States)

    Citronberg, Jessica S; Wilkens, Lynne R; Lim, Unhee; Hullar, Meredith A J; White, Emily; Newcomb, Polly A; Le Marchand, Loïc; Lampe, Johanna W

    2016-09-01

    Plasma lipopolysaccharide-binding protein (LBP), a measure of internal exposure to bacterial lipopolysaccharide, has been associated with several chronic conditions and may be a marker of chronic inflammation; however, no studies have examined the reliability of this biomarker in a healthy population. We examined the temporal reliability of LBP measured in archived samples from participants in two studies. In Study one, 60 healthy participants had blood drawn at two time points: baseline and follow-up (either three, six, or nine months). In Study two, 24 individuals had blood drawn three to four times over a seven-month period. We measured LBP in archived plasma by ELISA. Test-retest reliability was estimated by calculating the intraclass correlation coefficient (ICC). Plasma LBP concentrations showed moderate reliability in Study one (ICC 0.60, 95 % CI 0.43-0.75) and Study two (ICC 0.46, 95 % CI 0.26-0.69). Restricting the follow-up period improved reliability. In Study one, the reliability of LBP over a three-month period was 0.68 (95 % CI: 0.41-0.87). In Study two, the ICC of samples taken ≤seven days apart was 0.61 (95 % CI 0.29-0.86). Plasma LBP concentrations demonstrated moderate test-retest reliability in healthy individuals with reliability improving over a shorter follow-up period.

  20. Global sensitivity analysis for repeated measures studies with informative drop-out: A semi-parametric approach.

    Science.gov (United States)

    Scharfstein, Daniel; McDermott, Aidan; Díaz, Iván; Carone, Marco; Lunardon, Nicola; Turkoz, Ibrahim

    2017-05-23

    In practice, both testable and untestable assumptions are generally required to draw inference about the mean outcome measured at the final scheduled visit in a repeated measures study with drop-out. Scharfstein et al. (2014) proposed a sensitivity analysis methodology to determine the robustness of conclusions within a class of untestable assumptions. In their approach, the untestable and testable assumptions were guaranteed to be compatible; their testable assumptions were based on a fully parametric model for the distribution of the observable data. While convenient, these parametric assumptions have proven especially restrictive in empirical research. Here, we relax their distributional assumptions and provide a more flexible, semi-parametric approach. We illustrate our proposal in the context of a randomized trial for evaluating a treatment of schizoaffective disorder. © 2017, The International Biometric Society.

  1. 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...

  2. The near-infrared spectroscopy-derived deoxygenated haemoglobin breaking-point is a repeatable measure that demarcates exercise intensity domains.

    Science.gov (United States)

    Iannetta, Danilo; Qahtani, Ahmad; Mattioni Maturana, Felipe; Murias, Juan Manuel

    2017-09-01

    A breaking-point in the near-infrared spectroscopy (NIRS)-derived deoxygenated haemoglobin ([HHb]) profile towards the end of a ramp incremental (RI) cycling test has been associated to the respiratory compensation point (RCP). Despite the physiological value of this measure, its repeatability remains unknown. The aim was to examine the repeatability of the [HHb] breaking-point ([HHb]BP) and its association to RCP during a RI cycling test. A repeated measures design was performed on 11 males (30.5±8.4 year; 76.5±8.4kg) and 4 females (30.5±5.9 year; 61.9±4.4 Kg). Gas exchange and NIRS [HHb] data were collected during RI tests performed on two different days separated by 48h. The [HHb]BP and the RCP were determined and compared for each trial. The [HHb]BP and the respiratory compensation point (RCP) occurred at the same VO2 in test 1 and test 2 ([HHb]BP: 3.49±0.52Lmin(-1) test 1; 3.48±0.45Lmin(-1) test 2; RCP: 3.38±0.40Lmin(-1) test 1; 3.38±0.44Lmin(-1) test 2) (P>0.05). The VO2 associated with the [HHb]BP and the VO2 at RCP were not significantly different from each other either in test 1 as well as in test 2 (P>0.05). Neither test 1 nor test 2 showed significant mean average error between the VO2 at the [HHb]BP and RCP using Bland & Altman plots. The [HHb]BP is a repeatable measure that consistently occurs towards the end of a RI test. The association between the [HHb]BP and the RCP reinforces the idea that these parameters may share similar mechanistic basis. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  3. 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.

  4. Assessment of individual agreements with repeated measurements based on generalized confidence intervals.

    Science.gov (United States)

    Quiroz, Jorge; Burdick, Richard K

    2009-01-01

    Individual agreement between two measurement systems is determined using the total deviation index (TDI) or the coverage probability (CP) criteria as proposed by Lin (2000) and Lin et al. (2002). We used a variance component model as proposed by Choudhary (2007). Using the bootstrap approach, Choudhary (2007), and generalized confidence intervals, we construct bounds on TDI and CP. A simulation study was conducted to assess whether the bounds maintain the stated type I error probability of the test. We also present a computational example to demonstrate the statistical methods described in the paper.

  5. Real cell overlay measurement through design based metrology

    Science.gov (United States)

    Yoo, Gyun; Kim, Jungchan; Park, Chanha; Lee, Taehyeong; Ji, Sunkeun; Jo, Gyoyeon; Yang, Hyunjo; Yim, Donggyu; Yamamoto, Masahiro; Maruyama, Kotaro; Park, Byungjun

    2014-04-01

    Until recent device nodes, lithography has been struggling to improve its resolution limit. Even though next generation lithography technology is now facing various difficulties, several innovative resolution enhancement technologies, based on 193nm wavelength, were introduced and implemented to keep the trend of device scaling. Scanner makers keep developing state-of-the-art exposure system which guarantees higher productivity and meets a more aggressive overlay specification. "The scaling reduction of the overlay error has been a simple matter of the capability of exposure tools. However, it is clear that the scanner contributions may no longer be the majority component in total overlay performance. The ability to control correctable overlay components is paramount to achieve the desired performance.(2)" In a manufacturing fab, the overlay error, determined by a conventional overlay measurement: by using an overlay mark based on IBO and DBO, often does not represent the physical placement error in the cell area of a memory device. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion, caused by etching or CMP, also can be a source of the mismatch. Therefore, the requirement of a direct overlay measurement in the cell pattern gradually increases in the manufacturing field, and also in the development level. In order to overcome the mismatch between conventional overlay measurement and the real placement error of layer to layer in the cell area of a memory device, we suggest an alternative overlay measurement method utilizing by design, based metrology tool. A basic concept of this method is shown in figure1. A CD-SEM measurement of the overlay error between layer 1 and 2 could be the ideal method but it takes too long time to extract a lot of data from wafer level. An E-beam based DBM tool provides high speed to cover the whole wafer with high repeatability. It is enabled by using the design as a

  6. 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

  7. WCDMA直放站回波对消方案设计%Design of Echo Cancellation System for WCDMA Repeater

    Institute of Scientific and Technical Information of China (English)

    华强; 夏哲雷; 朱怀环; 祝建英

    2013-01-01

    A design of echo cancellation for WCDMA repeater is proposed based on WCDMA standard in digital intermediate frequency technology under the FPGA + DSP platform. Firstly CAZAC codes which is not relevant with WCDMA signals are sent as the training sequence for channel initial estimation. Secondly, delay and amplitude are distributed to LMS adaptive filter as the initial value, then the echo cancellation realized by generating cancelling signals which is approach to echo signals. The results prove that the design has a good performance in echo cancellation by the united simulation using MATLAB and SIMULINK.%基于WCDMA标准提出了FPGA+DPS平台下实现在数字中频技术中抵消WCDMA直放站回波干扰信号的方案.首先发射与WCDMA信号不相关的伪随机序列CAZAC码作为训练序列进行信道初估计,然后将初估计得到的时延和幅度信息作为赋给LMS自适应滤波器的初值,生成逼近干扰信号的抵消信号,实现回波对消.使用MATLAB和SIMULINK联合仿真,证明该方法拥有良好的性能.

  8. C-reactive Protein: Repeated Measurements will Improve Dialysis Patient Care.

    Science.gov (United States)

    Cobo, Gabriela; Qureshi, Abdul Rashid; Lindholm, Bengt; Stenvinkel, Peter

    2016-01-01

    Systemic inflammation is a common feature in the uremic phenotype and associates with poor outcomes. The awareness regarding the importance of inflammation assessment in chronic kidney disease (CKD) patients has risen in recent years, and despite the development of novel biomarkers, C-reactive protein (CRP) is still the most measured inflammatory parameter. Notwithstanding, the possible weak points of CRP determination, this biomarker has demonstrated being useful both for guidance in clinical practice and for risk estimation. In addition, regular determination of CRP among dialysis patients has been associated with better outcomes in different dialysis facilities. Because persistent inflammation may be a silent reflection of various pathophysiologic alterations in CKD, it is crucial that inflammatory markers are regularly monitored and therapeutic attempts be made to target this inflammation.

  9. Repeated heart rate measurement and cardiovascular outcomes in left ventricular systolic dysfunction.

    Science.gov (United States)

    Hamill, Victoria; Ford, Ian; Fox, Kim; Böhm, Michael; Borer, Jeffrey S; Ferrari, Roberto; Komajda, Michel; Steg, Philippe Gabriel; Tavazzi, Luigi; Tendera, Michal; Swedberg, Karl

    2015-10-01

    Elevated resting heart rate is associated with increased cardiovascular risk, particularly in patients with left ventricular systolic dysfunction. Heart rate is not monitored routinely in these patients. We hypothesized that routine monitoring of heart rate would increase its prognostic value in patients with left ventricular systolic dysfunction. We analyzed the relationship between heart rate measurements and a range of adverse cardiovascular outcomes, including hospitalization for worsening heart failure, in the pooled placebo-treated patients from the morBidity-mortality EvAlUaTion of the If inhibitor ivabradine in patients with coronary disease and left ventricULar dysfunction (BEAUTIFUL) trial and Systolic Heart failure treatment with the If inhibitor ivabradine (SHIFT) Trial, using standard and time-varying covariate Cox proportional hazards models. By adjusting for other prognostic factors, models were fitted for baseline heart rate alone or for time-updated heart rate (latest heart rate) alone or corrected for baseline heart rate or for immediate previous time-updated heart rate. Baseline heart rate was strongly associated with all outcomes apart from hospitalization for myocardial infarction. Time-updated heart rate increased the strengths of associations for all outcomes. Adjustment for baseline heart rate or immediate previous time-updated heart rate modestly reduced the prognostic importance of time-updated heart rate. For hospitalization for worsening heart failure, each 5 beats/min increase in baseline heart rate and time-updated heart rate was associated with a 15% (95% confidence interval, 12-18) and 22% (confidence interval, 19-40) increase in risk, respectively. Even after correction, the prognostic value of time-updated heart rate remained greater. In patients with left ventricular systolic dysfunction, time-updated heart rate is more strongly related with adverse cardiovascular outcomes than baseline heart rate. Heart rate should be measured to

  10. Concave cell design for FTIR measurements

    Institute of Scientific and Technical Information of China (English)

    Xiang Qin Lin; Zhi Xiang Zhang; Wan Qun Hu

    2011-01-01

    Wedged and V-shaped cells have advantages on depressing strong absorption bands and keeping the photo windows wide open without absorption block. Alternatively, this work presents a concave cell design, which is constructed by a plano-convex CaF2 lens in combination with a flat plate. Mathematical equations have been provided for data treatment with Matlab programs. The result indicates that the concave cell has advantages similar to the V-shaped cell. Reflection-absorption measurements of ethanol have been conducted on the cell in mid-IR region for demonstration. The spectrum obtained from the concave cell can easily be interpreted to regenerate its normal spectrum, which is fitting well with the spectrum taken in a conventional thin-layer cell. The concave cell is easier to construct and more convenient to operate, willing to have popular usages.

  11. Repeat-until-success quantum repeaters

    Science.gov (United States)

    Bruschi, David Edward; Barlow, Thomas M.; Razavi, Mohsen; Beige, Almut

    2014-09-01

    We propose a repeat-until-success protocol to improve the performance of probabilistic quantum repeaters. Conventionally, these rely on passive static linear-optics elements and photodetectors to perform Bell-state measurements (BSMs) with a maximum success rate of 50%. This is a strong impediment for entanglement swapping between distant quantum memories. Every time a BSM fails, entanglement needs to be redistributed between the corresponding memories in the repeater link. The key ingredients of our scheme are repeatable BSMs. Under ideal conditions, these turn probabilistic quantum repeaters into deterministic ones. Under realistic conditions, our protocol too might fail. However, using additional threshold detectors now allows us to improve the entanglement generation rate by almost orders of magnitude, at a nominal distance of 1000 km, compared to schemes that rely on conventional BSMs. This improvement is sufficient to make the performance of our scheme comparable to the expected performance of some deterministic quantum repeaters.

  12. 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.

  13. Hepatic 18F-FDG Uptake Measurements on PET/MR: Impact of Volume of Interest Location on Repeatability

    Directory of Open Access Journals (Sweden)

    Liran Domachevsky

    2017-01-01

    Full Text Available Background. To investigate same day 18F-FDG (Fluorodeoxyglucose PET (Positron Emission Tomography/MR (Magnetic Resonance test-retest repeatability of Standardized Uptake Value measurements normalized for body weight (SUV and lean body mass (SUL in different locations in the liver. Methods. This prospective study was IRB approved with written informed consent obtained. 35 patients (20 women and 15 men, 61±11.2 years that performed a whole-body 18F-FDG PET/MR followed by liver-dedicated contrast-enhanced 18F-FDG PET/MR were included. SUV/L max, mean, and peak were measured inferior to, superior to, and at the right portal vein and in the left lobe of the liver. The coefficient of variation (CV and intraclass correlation coefficient (ICC were calculated and Bland-Altman plots were obtained. Results. The variability for SUV/L’s measurements was lowest inferior to the portal vein (<9.2% followed by measurements performed at the level of the portal vein (<14.6%. Conclusion. The area inferior to the portal vein is the most reliable location for hepatic 18F-FDG uptake measurements on PET/MR.

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

    Science.gov (United States)

    Spiegelhalder, Kai; Regen, Wolfram; Nissen, Christoph; Feige, Bernd; Baglioni, Chiara; Riemann, Dieter; Hennig, Jürgen; Lange, Thomas

    2016-01-01

    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.

  15. 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.

  16. Repeatability of corticospinal and spinal measures during lengthening and shortening contractions in the human tibialis anterior muscle.

    Directory of Open Access Journals (Sweden)

    Jamie Tallent

    Full Text Available UNLABELLED: Elements of the human central nervous system (CNS constantly oscillate. In addition, there are also methodological factors and changes in muscle mechanics during dynamic muscle contractions that threaten the stability and consistency of transcranial magnetic stimulation (TMS and perpherial nerve stimulation (PNS measures. PURPOSE: To determine the repeatability of TMS and PNS measures during lengthening and shortening muscle actions in the intact human tibialis anterior. METHODS: On three consecutive days, 20 males performed lengthening and shortening muscle actions at 15, 25, 50 and 80% of maximal voluntary contraction (MVC. The amplitude of the Motor Evoked Potentials (MEPs produced by TMS was measured at rest and during muscle contraction at 90° of ankle joint position. MEPs were normalised to Mmax determined with PNS. The corticospinal silent period was recorded at 80% MVC. Hoffman reflex (H-reflex at 10% isometric and 25% shortening and lengthening MVCs, and V-waves during MVCs were also evoked on each of the three days. RESULTS: With the exception of MEPs evoked at 80% shortening MVC, all TMS-derived measures showed good reliability (ICC = 0.81-0.94 from days 2 to 3. Confidence intervals (CI, 95% were lower between days 2 and 3 when compared to days 1 and 2. MEPs significantly increased at rest from days 1 to 2 (P = 0.016 and days 1 to 3 (P = 0.046. The H-reflex during dynamic muscle contraction was reliable across the three days (ICC = 0.76-0.84. V-waves (shortening, ICC = 0.77, lengthening ICC = 0.54 and the H-reflex at 10% isometric MVC (ICC = 0.66 was generally less reliable over the three days. CONCLUSION: Although it is well known that measures of the intact human CNS exhibit moment-to-moment fluctuations, careful experimental arrangements make it possible to obtain consistent and repeatable measurements of corticospinal and spinal excitability in the actively lengthening and shortening human

  17. A Bayesian model for repeated measures zero-inflated count data with application to outpatient psychiatric service use

    Science.gov (United States)

    Neelon, Brian H.; O’Malley, A. James; Normand, Sharon-Lise T.

    2009-01-01

    In applications involving count data, it is common to encounter an excess number of zeros. In the study of outpatient service utilization, for example, the number of utilization days will take on integer values, with many subjects having no utilization (zero values). Mixed-distribution models, such as the zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB), are often used to fit such data. A more general class of mixture models, called hurdle models, can be used to model zero-deflation as well as zero-inflation. Several authors have proposed frequentist approaches to fitting zero-inflated models for repeated measures. We describe a practical Bayesian approach which incorporates prior information, has optimal small-sample properties, and allows for tractable inference. The approach can be easily implemented using standard Bayesian software. A study of psychiatric outpatient service use illustrates the methods. PMID:21339863

  18. Rational design of ligands targeting triplet repeating transcripts that cause RNA dominant disease: application to myotonic muscular dystrophy type 1 and spinocerebellar ataxia type 3.

    Science.gov (United States)

    Pushechnikov, Alexei; Lee, Melissa M; Childs-Disney, Jessica L; Sobczak, Krzysztof; French, Jonathan M; Thornton, Charles A; Disney, Matthew D

    2009-07-22

    Herein, we describe the design of high affinity ligands that bind expanded rCUG and rCAG repeat RNAs expressed in myotonic dystrophy type 1 (DM1) and spinocerebellar ataxia type 3. These ligands also inhibit, with nanomolar IC(50) values, the formation of RNA-protein complexes that are implicated in both disorders. The expanded rCUG and rCAG repeats form stable RNA hairpins with regularly repeating internal loops in the stem and have deleterious effects on cell function. The ligands that bind the repeats display a derivative of the bisbenzimidazole Hoechst 33258, which was identified by searching known RNA-ligand interactions for ligands that bind the internal loop displayed in these hairpins. A series of 13 modularly assembled ligands with defined valencies and distances between ligand modules was synthesized to target multiple motifs in these RNAs simultaneously. The most avid binder, a pentamer, binds the rCUG repeat hairpin with a K(d) of 13 nM. When compared to a series of related RNAs, the pentamer binds to rCUG repeats with 4.4- to >200-fold specificity. Furthermore, the affinity of binding to rCUG repeats shows incremental gains with increasing valency, while the background binding to genomic DNA is correspondingly reduced. Then, it was determined whether the modularly assembled ligands inhibit the recognition of RNA repeats by Muscleblind-like 1 (MBNL1) protein, the expanded-rCUG binding protein whose sequestration leads to splicing defects in DM1. Among several compounds with nanomolar IC(50) values, the most potent inhibitor is the pentamer, which also inhibits the formation of rCAG repeat-MBNL1 complexes. Comparison of the binding data for the designed synthetic ligands and MBNL1 to repeating RNAs shows that the synthetic ligand is 23-fold higher affinity and more specific to DM1 RNAs than MBNL1. Further studies show that the designed ligands are cell permeable to mouse myoblasts. Thus, cell permeable ligands that bind repetitive RNAs have been designed

  19. Design of a Robotic System to Measure Propulsion Work of Over-Ground Wheelchair Maneuvers.

    Science.gov (United States)

    Liles, Howard; Huang, Morris; Caspall, Jayme; Sprigle, Stephen

    2015-11-01

    A wheelchair-propelling robot has been developed to measure the efficiency of manual wheelchairs. The use of a robot has certain advantages compared to the use of human operators with respect to repeatability of measurements and the ability to compare many more wheelchair configurations than possible with human operators. Its design and implementation required significant engineering and validation of hardware and control systems. The robot can propel a wheelchair according to pre-programmed accelerations and velocities and measures the forces required to achieve these maneuvers. Wheel velocities were within 0.1 m/s of programmed values and coefficients of variation . Torque measurements were also repeatable with . By determining the propulsion torque required to propel the wheelchair through a series of canonical maneuvers, task-dependent input work for various wheelchairs and configurations can be compared. This metric would serve to quantify the combined inertial and frictional resistance of the mechanical system.

  20. Structural model for the interaction of a designed Ankyrin Repeat Protein with the human epidermal growth factor receptor 2.

    Directory of Open Access Journals (Sweden)

    V Chandana Epa

    Full Text Available Designed Ankyrin Repeat Proteins are a class of novel binding proteins that can be selected and evolved to bind to targets with high affinity and specificity. We are interested in the DARPin H10-2-G3, which has been evolved to bind with very high affinity to the human epidermal growth factor receptor 2 (HER2. HER2 is found to be over-expressed in 30% of breast cancers, and is the target for the FDA-approved therapeutic monoclonal antibodies trastuzumab and pertuzumab and small molecule tyrosine kinase inhibitors. Here, we use computational macromolecular docking, coupled with several interface metrics such as shape complementarity, interaction energy, and electrostatic complementarity, to model the structure of the complex between the DARPin H10-2-G3 and HER2. We analyzed the interface between the two proteins and then validated the structural model by showing that selected HER2 point mutations at the putative interface with H10-2-G3 reduce the affinity of binding up to 100-fold without affecting the binding of trastuzumab. Comparisons made with a subsequently solved X-ray crystal structure of the complex yielded a backbone atom root mean square deviation of 0.84-1.14 Ångstroms. The study presented here demonstrates the capability of the computational techniques of structural bioinformatics in generating useful structural models of protein-protein interactions.

  1. Co-crystallization with conformation-specific designed ankyrin repeat proteins explains the conformational flexibility of BCL-W.

    Science.gov (United States)

    Schilling, Johannes; Schöppe, Jendrik; Sauer, Evelyn; Plückthun, Andreas

    2014-06-12

    BCL-W is a member of the BCL-2 family of anti-apoptotic proteins. A key event in the regulation of apoptosis is the heterodimerization between anti-apoptotic and pro-apoptotic family members, which involves a conserved surface-exposed groove on the anti-apoptotic proteins. Crystal structures of the ligand binding-competent conformation exist for all anti-apoptotic family members, with the exception of BCL-W, due to the flexibility of the BCL-W groove region. Existing structures had suggested major deviations of the BCL-W groove region from the otherwise structurally highly related remaining anti-apoptotic family members. To capture its ligand binding-competent conformation by counteracting the conformational flexibility of the BCL-W groove, we had selected high-affinity groove-binding designed ankyrin repeat proteins (DARPins) using ribosome display. We now determined two high-resolution crystal structures of human BCL-W in complex with different DARPins at resolutions 1.5 and 1.85Å, in which the structure of BCL-W is virtually identical, and BCL-W adopts a conformation extremely similar to the ligand-free conformation of its closest relative BCL-XL in both structures. However, distinct differences to all previous BCL-W structures are evident, notably in the ligand-binding region. We provide the first structural explanation for the conformational flexibility of the BCL-W groove region in comparison to other BCL-2 family members. Due to the importance of the anti-apoptotic BCL-2 family as drug targets, the presented crystal structure of ligand binding-competent BCL-W may serve as a valuable basis for structure-based drug design in the future and provides a missing piece for the structural characterization of this protein family.

  2. Detection of quasi-periodic processes in repeated measurements: New approach for the fitting and clusterization of different data

    Science.gov (United States)

    Nigmatullin, R.; Rakhmatullin, R.

    2014-12-01

    Many experimentalists were accustomed to think that any independent measurement forms a non-correlated measurement that depends weakly from others. We are trying to reconsider this conventional point of view and prove that similar measurements form a strongly-correlated sequence of random functions with memory. In other words, successive measurements "remember" each other at least their nearest neighbors. This observation and justification on real data help to fit the wide set of data based on the Prony's function. The Prony's decomposition follows from the quasi-periodic (QP) properties of the measured functions and includes the Fourier transform as a partial case. New type of decomposition helps to obtain a specific amplitude-frequency response (AFR) of the measured (random) functions analyzed and each random function contains less number of the fitting parameters in comparison with its number of initial data points. Actually, the calculated AFR can be considered as the generalized Prony's spectrum (GPS), which will be extremely useful in cases where the simple model pretending on description of the measured data is absent but vital necessity of their quantitative description is remained. These possibilities open a new way for clusterization of the initial data and new information that is contained in these data gives a chance for their detailed analysis. The electron paramagnetic resonance (EPR) measurements realized for empty resonator (pure noise data) and resonator containing a sample (CeO2 in our case) confirmed the existence of the QP processes in reality. But we think that the detection of the QP processes is a common feature of many repeated measurements and this new property of successive measurements can attract an attention of many experimentalists. To formulate some general conditions that help to identify and then detect the presence of some QP process in the repeated experimental measurements. To find a functional equation and its solution that

  3. Association between proton magnetic resonance spectroscopy measurements and CAG repeat number in patients with spinocerebellar ataxias 2, 3, or 6.

    Directory of Open Access Journals (Sweden)

    Po-Shan Wang

    Full Text Available The aim of this study was to correlate magnetic resonance spectroscopy (MRS measurements, including that for the N-acetyl aspartate (NAA/creatine (Cr ratio in the vermis (denoted V-NAA, right cerebellar hemisphere (R-NAA, and left (L-NAA cerebellar hemisphere, with the clinical scale for the assessment and rating of ataxia (SARA score for patients with spinocerebellar ataxia (SCA types 2, 3, and 6. A total of 24 patients with SCA2, 48 with SCA3, and 16 with SCA6 were recruited; 12 patients with SCA2, 43 with SCA3, and 8 with SCA6 underwent detailed magnetic resonance neuroimaging. Forty-four healthy, age-matched individuals without history of neurologic disease served as control subjects. V-NAA and patient age were used to calculate the predicted age at which a patient with SCA2 or SCA3 would reach an onset V-NAA value. Results showed the following: the NAA/Cr ratio decreased with increasing age in patients with SCA but not in control subjects; the SARA score increased progressively with age and duration of illness; V-NAA showed a better correlation with SARA score than R-NAA in patients with SCA2 or SCA3; the ratio of age to V-NAA correlated well with CAG repeat number; the retrospectively predicted age of onset for SCA2 and SCA3 was consistent with patient-reported age of onset; R-NAA showed a better correlation with SARA score than V-NAA in patients with SCA6; V-NAA and R-NAA correlated with clinical severity (SARA score in patients with SCA. The correlation between CAG repeat number and age could be expressed as a simple linear function, which might explain previous observations claiming that the greater the CAG repeat number, the earlier the onset of illness and the faster the disease progression. These findings support the use of MRS values to predict age of disease onset and to retrospectively evaluate the actual age of disease onset in SCA.

  4. Association between proton magnetic resonance spectroscopy measurements and CAG repeat number in patients with spinocerebellar ataxias 2, 3, or 6.

    Science.gov (United States)

    Wang, Po-Shan; Chen, Hung-Chieh; Wu, Hsiu-Mei; Lirng, Jiing-Feng; Wu, Yu-Te; Soong, Bing-Wen

    2012-01-01

    The aim of this study was to correlate magnetic resonance spectroscopy (MRS) measurements, including that for the N-acetyl aspartate (NAA)/creatine (Cr) ratio in the vermis (denoted V-NAA), right cerebellar hemisphere (R-NAA), and left (L-NAA) cerebellar hemisphere, with the clinical scale for the assessment and rating of ataxia (SARA) score for patients with spinocerebellar ataxia (SCA) types 2, 3, and 6. A total of 24 patients with SCA2, 48 with SCA3, and 16 with SCA6 were recruited; 12 patients with SCA2, 43 with SCA3, and 8 with SCA6 underwent detailed magnetic resonance neuroimaging. Forty-four healthy, age-matched individuals without history of neurologic disease served as control subjects. V-NAA and patient age were used to calculate the predicted age at which a patient with SCA2 or SCA3 would reach an onset V-NAA value. Results showed the following: the NAA/Cr ratio decreased with increasing age in patients with SCA but not in control subjects; the SARA score increased progressively with age and duration of illness; V-NAA showed a better correlation with SARA score than R-NAA in patients with SCA2 or SCA3; the ratio of age to V-NAA correlated well with CAG repeat number; the retrospectively predicted age of onset for SCA2 and SCA3 was consistent with patient-reported age of onset; R-NAA showed a better correlation with SARA score than V-NAA in patients with SCA6; V-NAA and R-NAA correlated with clinical severity (SARA score) in patients with SCA. The correlation between CAG repeat number and age could be expressed as a simple linear function, which might explain previous observations claiming that the greater the CAG repeat number, the earlier the onset of illness and the faster the disease progression. These findings support the use of MRS values to predict age of disease onset and to retrospectively evaluate the actual age of disease onset in SCA.

  5. Diffusion-weighted magnetic resonance imaging for assessment of lung lesions: repeatability of the apparent diffusion coefficient measurement

    Energy Technology Data Exchange (ETDEWEB)

    Bernardin, L.; Douglas, N.H.M.; Collins, D.J.; Giles, S.L.; O' Flynn, E.A.M.; Orton, M.; DeSouza, N.M. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK and EPSRC Cancer Imaging Centre, Surrey (United Kingdom)

    2014-02-15

    To establish repeatability of apparent diffusion coefficients (ADCs) acquired from free-breathing diffusion-weighted magnetic resonance imaging (DW-MRI) in malignant lung lesions and investigate effects of lesion size, location and respiratory motion. Thirty-six malignant lung lesions (eight patients) were examined twice (1- to 5-h interval) using T1-weighted, T2-weighted and axial single-shot echo-planar DW-MRI (b = 100, 500, 800 s/mm{sup 2}) during free-breathing. Regions of interest around target lesions on computed b = 800 s/mm{sup 2} images by two independent observers yielded ADC values from maps (pixel-by-pixel fitting using all b values and a mono-exponential decay model). Intra- and inter-observer repeatability was assessed per lesion, per patient and by lesion size (> or <2 cm) or location. ADCs were similar between observers (mean ± SD, 1.15 ± 0.28 x 10{sup -3} mm{sup 2}/s, observer 1; 1.15 ± 0.29 x 10{sup -3} mm{sup 2}/s, observer 2). Intra-observer coefficients of variation of the mean [median] ADC per lesion and per patient were 11 % [11.4 %], 5.7 % [5.7 %] for observer 1 and 9.2 % [9.5 %], 3.9 % [4.7 %] for observer 2 respectively; inter-observer values were 8.9 % [9.3 %] (per lesion) and 3.0 % [3.7 %] (per patient). Inter-observer coefficient of variation (CoV) was greater for lesions <2 cm (n = 20) compared with >2 cm (n = 16) (10.8 % vs 6.5 % ADC{sub mean}, 11.3 % vs 6.7 % ADC{sub median}) and for mid (n = 14) vs apical (n = 9) or lower zone (n = 13) lesions (13.9 %, 2.7 %, 3.8 % respectively ADC{sub mean}; 14.2 %, 2.8 %, 4.7 % respectively ADC{sub median}). Free-breathing DW-MRI of whole lung achieves good intra- and inter-observer repeatability of ADC measurements in malignant lung tumours. (orig.)

  6. 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.

  7. The use of portable NIRS to measure muscle oxygenation and haemodynamics during a repeated sprint running test.

    Science.gov (United States)

    Jones, Ben; Hesford, Catherine M; Cooper, Chris E

    2013-01-01

    Portable near-infrared spectroscopy (NIRS) devices were originally developed for use in exercise and sports science by Britton Chance in the 1990s (the RunMan and microRunman series). However, only recently with the development of more robust, and wireless systems, has the routine use in elite sport become possible. As with the medical use of NIRS, finding applications of the technology that are relevant to practitioners is the key issue. One option is to use NIRS to track exercise training-induced adaptations in muscle. Portable NIRS devices enable monitoring during the normal 'field' routine uses to assess fitness, such as repeat sprint shuttle tests. Knowledge about the acute physiological responses to these specific tests has practical applications within team sport training prescription, where development of both central and peripheral determinants of high-intensity intermittent exercise needs to be considered. The purpose of this study was to observe NIRS-detected parameters during a repeat sprint test. We used the PortaMon, a two wavelength spatially resolved NIR spectrometer manufactured by Artinis Inc., to assess NIR changes in the gastrocnemius muscle of both the left and right leg during high-intensity running. Six university standard rugby players were assessed (age 20 ± 1.5 years; height 183 ± 1.0 cm; weight 89.4 ± 5.8 kg; body fat 12.2 ± 3.0 %); the subjects completed nine repeated shuttle runs, which incorporated forward, backward and change of direction movements. Individual sprint time, total time to complete test, blood lactate response (BL), heart rate values (HR) and haemoglobin variables (ΔHHb, ΔtHb, ΔHbO2 and ΔTSI%) were measured. Total time to complete the test was 260 ± 20 s, final blood lactate was 14.3 ± 2.8 mM, and maximal HR 182 ± 5 bpm. NIRS variables displayed no differences between right and left legs. During the test, the group-averaged data showed a clear decrease in HbO2 (max. decrease 11.41 ± 4.95 μM), increase in HHb

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

    LENUS (Irish Health Repository)

    Surgenor, Paul Wg

    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.

  9. Relationship between measures of aerobic fitness, speed and repeated sprint ability in full and part time youth soccer players.

    Science.gov (United States)

    Gibson, N; Currie, J; Johnston, R; Hill, J

    2013-02-01

    The aim of the study was to investigate the relationship between repeated sprint ability (RSA) involving changes in direction, short linear sprinting and aerobic capacity in young elite soccer players. A secondary aim was to assess any differences in performance of these assessments between players of different age groups. Thirty-two male adolescent soccer players belonging to the same elite club academy were assessed for RSA comprising 6 x 40m efforts interspersed by 25s recovery, linear sprinting speed over 15m, and aerobic capacity via the YYIE2 assessment. There was a significant correlation between performance in the YYIE2 and RSA total time, RSA fastest sprint and RSA percentage decrement (r = -0.71, -0.53, and -0.52 respectively. Psprint (Psprinting. Assessments of RSA over 40m and incorporating changes of direction appear to be significantly correlated with YYIE2 performance in young elite level soccer players. In addition older players performed significantly better in the YYIE2 assessment and RSA protocol but not in short linear sprinting. These results have implications for the design of assessment protocols for young elite soccer players of different ages.

  10. How integrated are behavioral and endocrine stress response traits? A repeated measures approach to testing the stress-coping style model.

    Science.gov (United States)

    Boulton, Kay; Couto, Elsa; Grimmer, Andrew J; Earley, Ryan L; Canario, Adelino V M; Wilson, Alastair J; Walling, Craig A

    2015-02-01

    It is widely expected that physiological and behavioral stress responses will be integrated within divergent stress-coping styles (SCS) and that these may represent opposite ends of a continuously varying reactive-proactive axis. If such a model is valid, then stress response traits should be repeatable and physiological and behavioral responses should also change in an integrated manner along a major axis of among-individual variation. While there is some evidence of association between endocrine and behavioral stress response traits, few studies incorporate repeated observations of both. To test this model, we use a multivariate, repeated measures approach in a captive-bred population of Xiphophorus birchmanni. We quantify among-individual variation in behavioral stress response to an open field trial (OFT) with simulated predator attack (SPA) and measure waterborne steroid hormone levels (cortisol, 11-ketotestosterone) before and after exposure. Under the mild stress stimulus (OFT), (multivariate) behavioral variation among individuals was consistent with a strong axis of personality (shy-bold) or coping style (reactive-proactive) variation. However, behavioral responses to a moderate stressor (SPA) were less repeatable, and robust statistical support for repeatable endocrine state over the full sampling period was limited to 11-ketotestosterone. Although post hoc analysis suggested cortisol expression was repeatable over short time periods, qualitative relationships between behavior and glucocorticoid levels were counter to our a priori expectations. Thus, while our results clearly show among-individual differences in behavioral and endocrine traits associated with stress response, the correlation structure between these is not consistent with a simple proactive-reactive axis of integrated stress-coping style. Additionally, the low repeatability of cortisol suggests caution is warranted if single observations (or indeed repeat measures over short sampling

  11. Application of composite estimation in studies of animal population production with two-stage repeated sample designs.

    Science.gov (United States)

    Farver, T B; Holt, D; Lehenbauer, T; Greenley, W M

    1997-05-01

    This paper reports results from two example data sets of a two-stage sampling design where sampling (in panels) both farms and animals within selected farms increases the efficiency of parameter estimation from measurements recorded over time. With such a design, not only are farms replaced from time-to-time but also animals subsampled within retained farms are subject to replacement. Three general categories of parameters estimated for the population (the set of animals belonging to the universe of farms of interest) were (1) the total at each measurement occasion; (2) the difference between means or totals on successive measurement occasions; (3) the total over a sequence of successive measurement periods. Whereas several responses at the farm level were highly correlated over time (rho 1), the corresponding animal responses were less correlated over time (rho 2)-leading to only moderate gains in relative efficiency. Intraclass correlation values were too low in most cases to counteract the overall negative impact of rho 2. In general, sizeable gains in relative efficiency were observed for estimating change-confirming a previous result which showed this to be true provided that rho 1 was high (irrespective of rho 2).

  12. Repeated-sprint cycling does not induce respiratory muscle fatigue in active adults: measurements from the powerbreathe® inspiratory muscle trainer.

    Science.gov (United States)

    Minahan, Clare; Sheehan, Beth; Doutreband, Rachel; Kirkwood, Tom; Reeves, Daniel; Cross, Troy

    2015-03-01

    This study examined respiratory muscle strength using the POWERbreathe® inspiratory muscle trainer (i.e., 'S-Index') before and after repeated-sprint cycling for comparison with maximal inspiratory pressure (MIP) values obtained during a Mueller maneuver. The S-Index was measured during six trials across two sessions using the POWERbreathe® and MIP was measured during three trials in a single session using a custom-made manometer in seven recreationally active adults. Global respiratory muscle strength was measured using both devices before and after the performance of sixteen, 6-s sprints on a cycle ergometer. Intraclass correlation coefficients for the POWERbreathe® S-index indicated excellent (p Repeated-sprint cycling had no effect on respiratory muscle strength as measured by the POWERbreathe® (p > 0.99) and during the Mueller maneuver (p > 0.99). The POWERbreathe® S-Index is a moderately reliable, but not equivalent, measure of MIP determined during a Mueller maneuver. Furthermore, repeated-sprint cycling does not induce globalized respiratory muscle fatigue in recreationally-active adults. Key pointsThe S-Index as measured by the POWERbreathe® is a reliable measure of respiratory muscle strengthThe S-Index does not accurately reflect maximal inspiratory pressure obtained from a Mueller maneuverRepeated-sprint cycling does not induce respiratory muscle fatigue as measured by the POWERbreathe® and the Manometer.

  13. 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.

  14. Ambient particulate air pollution and circulating antioxidant enzymes: A repeated-measure study in healthy adults in Beijing, China.

    Science.gov (United States)

    Wu, Shaowei; Wang, Bin; Yang, Di; Wei, Hongying; Li, Hongyu; Pan, Lu; Huang, Jing; Wang, Xin; Qin, Yu; Zheng, Chanjuan; Shima, Masayuki; Deng, Furong; Guo, Xinbiao

    2016-01-01

    The association of systemic antioxidant activity with ambient air pollution has been unclear. A panel of 40 healthy college students underwent repeated blood collection for 12 occasions under three exposure scenarios before and after relocating from a suburban area to an urban area in Beijing, China in 2010-2011. We measured various air pollutants including fine particles (PM2.5) and determined circulating levels of antioxidant enzymes extracellular superoxide dismutase (EC-SOD) and glutathione peroxidase 1 (GPX1) in the laboratory. An interquartile range increase of 63.4 μg/m(3) at 3-d PM2.5 moving average was associated with a 6.3% (95% CI: 0.6, 12.4) increase in EC-SOD and a 5.5% (95% CI: 1.3, 9.8) increase in GPX1. Several PM2.5 chemical constituents, including negative ions (nitrate and chloride) and metals (e.g., iron and strontium), were consistently associated with increases in EC-SOD and GPX1. Our results support activation of circulating antioxidant enzymes following exposure to particulate air pollution. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. A method to construct a points system to predict cardiovascular disease considering repeated measures of risk factors

    Science.gov (United States)

    Carbayo-Herencia, Julio Antonio; Vigo, Maria Isabel; Gil-Guillén, Vicente Francisco

    2016-01-01

    Current predictive models for cardiovascular disease based on points systems use the baseline situation of the risk factors as independent variables. These models do not take into account the variability of the risk factors over time. Predictive models for other types of disease also exist that do consider the temporal variability of a single biological marker in addition to the baseline variables. However, due to their complexity these other models are not used in daily clinical practice. Bearing in mind the clinical relevance of these issues and that cardiovascular diseases are the leading cause of death worldwide we show the properties and viability of a new methodological alternative for constructing cardiovascular risk scores to make predictions of cardiovascular disease with repeated measures of the risk factors and retaining the simplicity of the points systems so often used in clinical practice (construction, statistical validation by simulation and explanation of potential utilization). We have also applied the system clinically upon a set of simulated data solely to help readers understand the procedure constructed. PMID:26893963

  16. Are diagnostic criteria for acute malnutrition affected by hydration status in hospitalized children? A repeated measures study

    Directory of Open Access Journals (Sweden)

    Fegan Gregory

    2011-09-01

    Full Text Available Abstract Introduction Dehydration and malnutrition commonly occur together among ill children in developing countries. Dehydration (change in total body water is known to alter weight. Although muscle tissue has high water content, it is not known whether mid-upper arm circumference (MUAC may be altered by changes in tissue hydration. We aimed to determine whether rehydration alters MUAC, MUAC Z score (MUACz, weight-for-length Z-score (WFLz and classification of nutritional status among hospitalised Kenyan children admitted with signs of dehydration. Study procedure We enrolled children aged from 3 months to 5 years admitted to a rural Kenyan district hospital with clinical signs compatible with dehydration, and without kwashiorkor. Anthropometric measurements were taken at admission and repeated after 48 hours of treatment, which included rehydration by WHO protocols. Changes in weight observed during this period were considered to be due to changes in hydration status. Results Among 325 children (median age 11 months the median weight gain (rehydration after 48 hours was 0.21 kg, (an increase of 2.9% of admission body weight. Each 1% change in weight was associated with a 0.40 mm (95% CI: 0.30 to 0.44 mm, p Conclusion MUAC is less affected by dehydration than WFLz and is therefore more suitable for nutritional assessment of ill children. However, both WFLz and MUAC misclassify SAM among dehydrated children. Nutritional status should be re-evaluated following rehydration, and management adjusted accordingly.

  17. Selecting a linear mixed model for longitudinal data: repeated measures analysis of variance, covariance pattern model, and growth curve approaches.

    Science.gov (United States)

    Liu, Siwei; Rovine, Michael J; Molenaar, Peter C M

    2012-03-01

    With increasing popularity, growth curve modeling is more and more often considered as the 1st choice for analyzing longitudinal data. Although the growth curve approach is often a good choice, other modeling strategies may more directly answer questions of interest. It is common to see researchers fit growth curve models without considering alterative modeling strategies. In this article we compare 3 approaches for analyzing longitudinal data: repeated measures analysis of variance, covariance pattern models, and growth curve models. As all are members of the general linear mixed model family, they represent somewhat different assumptions about the way individuals change. These assumptions result in different patterns of covariation among the residuals around the fixed effects. In this article, we first indicate the kinds of data that are appropriately modeled by each and use real data examples to demonstrate possible problems associated with the blanket selection of the growth curve model. We then present a simulation that indicates the utility of Akaike information criterion and Bayesian information criterion in the selection of a proper residual covariance structure. The results cast doubt on the popular practice of automatically using growth curve modeling for longitudinal data without comparing the fit of different models. Finally, we provide some practical advice for assessing mean changes in the presence of correlated data.

  18. Repeated measurements of blood lactate concentration as a prognostic marker in horses with acute colitis evaluated with classification and regression trees (CART) and random forest analysis.

    Science.gov (United States)

    Petersen, M B; Tolver, A; Husted, L; Tølbøll, T H; Pihl, T H

    2016-07-01

    The objective of this study was to investigate the prognostic value of single and repeated measurements of blood l-lactate (Lac) and ionised calcium (iCa) concentrations, packed cell volume (PCV) and plasma total protein (TP) concentration in horses with acute colitis. A total of 66 adult horses admitted with acute colitis (2 mmol/L (sensitivity, 0.72; specificity, 0.8). In conclusion, blood lactate concentration measured at admission and repeated 6 h later aided the prognostic evaluation of horses with acute colitis in this population with a very high mortality rate. This should allow clinicians to give a more reliable prognosis for the horse.

  19. Cardiac output measurement in newborn infants using the ultrasonic cardiac output monitor: an assessment of agreement with conventional echocardiography, repeatability and new user experience.

    Science.gov (United States)

    Patel, Neil; Dodsworth, Melissa; Mills, John F

    2011-05-01

    To assess (1) agreement between the ultrasonic cardiac output monitor (USCOM) 1A device for measurement of cardiac output in newborn infants and conventional echocardiography (ECHO), (2) repeatability of USCOM measurements and (3) agreement between novice and expert users of the USCOM. A prospective observational study. The Neonatal Unit at the Royal Children's Hospital, Melbourne, Australia. 56 term and near-term infants, with no evidence of structural or functional cardiovascular disease, or haemodynamic shunts. Agreement between ECHO and USCOM was assessed by paired measurements of ventricular outputs by a single experienced user. Repeatability was assessed using five repeated measurements in 10 infants. Agreement between five novices and one expert user was assessed by paired USCOM measurements over 30 training measurements. Agreement between USCOM and ECHO for left ventricular output (LVO) was (bias, ±limits of agreement, mean % error): 14, ±108 ml/kg/min, 43%, and for right ventricular output (RVO): -59, ±160, ml/kg/min, 57%. Intra-observer repeatability was 6.7% for USCOM LVO and 3.6% for ECHO LVO. After five training measurements, the mean difference between USCOM measures of LVO by novice and expert users was less than 50 ml/kg/min, but with variability. Repeatability of USCOM measures is high in newborn infants. New users can be trained quickly, but with high inter-user variability. Agreement between USCOM and conventional ECHO is broad, and worse for RVO and LVO. Further studies are required to assess the ability of the device to detect clinically significant changes in infant cardiac output.

  20. Effects of CAG repeat length, HTT protein length and protein context on cerebral metabolism measured using magnetic resonance spectroscopy in transgenic mouse models of Huntington's disease.

    Science.gov (United States)

    Jenkins, Bruce G; Andreassen, Ole A; Dedeoglu, Alpaslan; Leavitt, Blair; Hayden, Michael; Borchelt, David; Ross, Christopher A; Ferrante, Robert J; Beal, M Flint

    2005-10-01

    Huntington's disease is a neurodegenerative illness caused by expansion of CAG repeats at the N-terminal end of the protein huntingtin. We examined longitudinal changes in brain metabolite levels using in vivo magnetic resonance spectroscopy in five different mouse models. There was a large (>50%) exponential decrease in N-acetyl aspartate (NAA) with time in both striatum and cortex in mice with 150 CAG repeats (R6/2 strain). There was a linear decrease restricted to striatum in N171-82Q mice with 82 CAG repeats. Both the exponential and linear decreases of NAA were paralleled in time by decreases in neuronal area measured histologically. Yeast artificial chromosome transgenic mice with 72 CAG repeats, but low expression levels, had less striatal NAA loss than the N171-82Q mice (15% vs. 43%). We evaluated the effect of gene context in mice with an approximate 146 CAG repeat on the hypoxanthine phosphoribosyltransferase gene (HPRT). HPRT mice developed an obese phenotype in contrast to weight loss in the R6/2 and N171-82Q mice. These mice showed a small striatal NAA loss (21%), and a possible increase in brain lipids detectable by magnetic resonance (MR) spectroscopy and decreased brain water T1. Our results indicate profound metabolic defects that are strongly affected by CAG repeat length, as well as gene expression levels and protein context.

  1. DESIGNING AND MEASURING CAPABILITY. A NEW PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Ovidiu COCENESCU

    2013-01-01

    Full Text Available The concept of capability has long been a topic for debate among planners. The main benefit brought by it is that of ensuring the connection between objectives and necessary financial resources. Thus, capability is a median element within the process of integrated planning. In this context, there are sceptics who consider that capability cannot be measured. However, this article aims at presenting a pattern and a formula for measuring and interpreting the level of capability.

  2. Impact of land-use on carbon storage as dependent on soil texture: evidence from a desertified dryland using repeated paired sampling design.

    Science.gov (United States)

    Ye, Xuehua; Tang, Shuangli; Cornwell, William K; Gao, Shuqin; Huang, Zhenying; Dong, Ming; Cornelissen, Johannes H C

    2015-03-01

    Desertification resulting from land-use affects large dryland areas around the world, accompanied by carbon loss. However it has been difficult to interpret different land-use contributions to carbon pools owing to confounding factors related to climate, topography, soil texture and other original soil properties. To avoid such confounding effects, a unique systematic and extensive repeated design of paired sampling plots of different land-use types was adopted on Ordos Plateau, N China. The sampling enabled to quantify the effects of the predominant land-use types on carbon storage as dependent on soil texture, and to define the most promising land-use choices for carbon storage, both in grassland on sandy soil and in desert grassland on brown calcareous soil. The results showed that (1) desertification control should be an effective measure to improve the carbon sequestration in sandy grassland, and shrub planting should be better than grass planting; (2) development of man-made grassland should be a good choice to solve the contradictions of ecology and economy in desert grassland; (3) grassland on sandy soil is more vulnerable to soil degradation than desert grassland on brown calcareous soil. The results may be useful for the selection of land-use types, aiming at desertification prevention in drylands. Follow-up studies should directly investigate the role of soil texture on the carbon storage dynamic caused by land-use change. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Detecting variable responses in time-series using repeated measures ANOVA: Application to physiologic challenges [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Paul M. Macey

    2016-07-01

    Full Text Available We present an approach to analyzing physiologic timetrends recorded during a stimulus by comparing means at each time point using repeated measures analysis of variance (RMANOVA. The approach allows temporal patterns to be examined without an a priori model of expected timing or pattern of response. The approach was originally applied to signals recorded from functional magnetic resonance imaging (fMRI volumes-of-interest (VOI during a physiologic challenge, but we have used the same technique to analyze continuous recordings of other physiological signals such as heart rate, breathing rate, and pulse oximetry. For fMRI, the method serves as a complement to whole-brain voxel-based analyses, and is useful for detecting complex responses within pre-determined brain regions, or as a post-hoc analysis of regions of interest identified by whole-brain assessments. We illustrate an implementation of the technique in the statistical software packages R and SAS. VOI timetrends are extracted from conventionally preprocessed fMRI images. A timetrend of average signal intensity across the VOI during the scanning period is calculated for each subject. The values are scaled relative to baseline periods, and time points are binned. In SAS, the procedure PROC MIXED implements the RMANOVA in a single step. In R, we present one option for implementing RMANOVA with the mixed model function “lme”. Model diagnostics, and predicted means and differences are best performed with additional libraries and commands in R; we present one example. The ensuing results allow determination of significant overall effects, and time-point specific within- and between-group responses relative to baseline. We illustrate the technique using fMRI data from two groups of subjects who underwent a respiratory challenge. RMANOVA allows insight into the timing of responses and response differences between groups, and so is suited to physiologic testing paradigms eliciting complex

  4. The Effects of Group Leader Learning Style on Student Knowledge Gain in a Leadership Camp Setting: A Repeated-Measures Experiment

    Science.gov (United States)

    Brown, Nicholas R.; Terry, Robert, Jr.

    2013-01-01

    Many state FFA associations conduct summer camps focusing on leadership and personal development for FFA members. Interestingly, little research has been conducted on the impact or outcomes of these common activities. The purpose of this split-plot factorial repeated-measures experiment was to assess the level of campers' learning of the…

  5. Predictors and Variability of Repeat Measurements of Urinary Phenols and Parabens in a Cohort of Shanghai Women and Men

    Science.gov (United States)

    Buckley, Jessie P.; Yang, Gong; Liao, Linda M.; Satagopan, Jaya; Calafat, Antonia M.; Matthews, Charles E.; Cai, Qiuyin; Ji, Bu-Tian; Cai, Hui; Wolff, Mary S.; Rothman, Nathaniel; Zheng, Wei; Xiang, Yong-Bing; Shu, Xiao-Ou; Gao, Yu-Tang; Chow, Wong-Ho

    2014-01-01

    , under certain circumstances, among women. Citation: Engel LS, Buckley JP, Yang G, Liao LM, Satagopan J, Calafat AM, Matthews CE, Cai Q, Ji BT, Cai H, Engel SM, Wolff MS, Rothman N, Zheng W, Xiang YB, Shu XO, Gao YT, Chow WH. 2014. Predictors and variability of repeat measurements of urinary phenols and parabens in a cohort of Shanghai women and men. Environ Health Perspect 122:733–740; http://dx.doi.org/10.1289/ehp.1306830 PMID:24659570

  6. A review of the reporting and handling of missing data in cohort studies with repeated assessment of exposure measures

    Directory of Open Access Journals (Sweden)

    Karahalios Amalia

    2012-07-01

    Full Text Available Abstract Background Retaining participants in cohort studies with multiple follow-up waves is difficult. Commonly, researchers are faced with the problem of missing data, which may introduce biased results as well as a loss of statistical power and precision. The STROBE guidelines von Elm et al. (Lancet, 370:1453-1457, 2007; Vandenbroucke et al. (PLoS Med, 4:e297, 2007 and the guidelines proposed by Sterne et al. (BMJ, 338:b2393, 2009 recommend that cohort studies report on the amount of missing data, the reasons for non-participation and non-response, and the method used to handle missing data in the analyses. We have conducted a review of publications from cohort studies in order to document the reporting of missing data for exposure measures and to describe the statistical methods used to account for the missing data. Methods A systematic search of English language papers published from January 2000 to December 2009 was carried out in PubMed. Prospective cohort studies with a sample size greater than 1,000 that analysed data using repeated measures of exposure were included. Results Among the 82 papers meeting the inclusion criteria, only 35 (43% reported the amount of missing data according to the suggested guidelines. Sixty-eight papers (83% described how they dealt with missing data in the analysis. Most of the papers excluded participants with missing data and performed a complete-case analysis (n = 54, 66%. Other papers used more sophisticated methods including multiple imputation (n = 5 or fully Bayesian modeling (n = 1. Methods known to produce biased results were also used, for example, Last Observation Carried Forward (n = 7, the missing indicator method (n = 1, and mean value substitution (n = 3. For the remaining 14 papers, the method used to handle missing data in the analysis was not stated. Conclusions This review highlights the inconsistent reporting of missing data in cohort studies and the continuing

  7. A review of the reporting and handling of missing data in cohort studies with repeated assessment of exposure measures.

    Science.gov (United States)

    Karahalios, Amalia; Baglietto, Laura; Carlin, John B; English, Dallas R; Simpson, Julie A

    2012-07-11

    Retaining participants in cohort studies with multiple follow-up waves is difficult. Commonly, researchers are faced with the problem of missing data, which may introduce biased results as well as a loss of statistical power and precision. The STROBE guidelines von Elm et al. (Lancet, 370:1453-1457, 2007); Vandenbroucke et al. (PLoS Med, 4:e297, 2007) and the guidelines proposed by Sterne et al. (BMJ, 338:b2393, 2009) recommend that cohort studies report on the amount of missing data, the reasons for non-participation and non-response, and the method used to handle missing data in the analyses. We have conducted a review of publications from cohort studies in order to document the reporting of missing data for exposure measures and to describe the statistical methods used to account for the missing data. A systematic search of English language papers published from January 2000 to December 2009 was carried out in PubMed. Prospective cohort studies with a sample size greater than 1,000 that analysed data using repeated measures of exposure were included. Among the 82 papers meeting the inclusion criteria, only 35 (43%) reported the amount of missing data according to the suggested guidelines. Sixty-eight papers (83%) described how they dealt with missing data in the analysis. Most of the papers excluded participants with missing data and performed a complete-case analysis (n=54, 66%). Other papers used more sophisticated methods including multiple imputation (n=5) or fully Bayesian modeling (n=1). Methods known to produce biased results were also used, for example, Last Observation Carried Forward (n=7), the missing indicator method (n=1), and mean value substitution (n=3). For the remaining 14 papers, the method used to handle missing data in the analysis was not stated. This review highlights the inconsistent reporting of missing data in cohort studies and the continuing use of inappropriate methods to handle missing data in the analysis. Epidemiological journals

  8. High temperature hall effect measurement system design, measurement and analysis

    Science.gov (United States)

    Berkun, Isil

    A reliable knowledge of the transport properties of semiconductor materials is essential for the development and understanding of a number of electronic devices. In this thesis, the work on developing a Hall Effect measurement system with software based data acqui- sition and control for a temperature range of 300K-700K will be described. A system was developed for high temperature measurements of materials including single crystal diamond, poly-crystalline diamond, and thermoelectric compounds. An added capability for monitor- ing the current versus voltage behavior of the contacts was used for studying the influence of ohmic and non-ohmic contacts on Hall Effect measurements. The system has been primar- ily used for testing the transport properties of boron-doped single crystal diamond (SCD) deposited in a microwave plasma-assisted chemical vapor deposition (MPCVD) reactor [1]. Diamond has several outstanding properties that are of high interest for its development as an electronic material. These include a relatively wide band gap of 5.5 (eV), high thermal conductivity, high mobility, high saturation velocity, and a high breakdown voltage. For a temperature range of 300K-700K, IV curves, Hall mobilities and carrier concentrations are shown. Temperature dependent Hall effect measurements have shown carrier concentrations from below 1017cm --3 to approximately 1021 cm--3 with mobilities ranging from 763( cm2/V s) to 0.15(cm 2/V s) respectively. Simulation results have shown the effects of single and mixed carrier models, activation energies, effective mass and doping concentrations. These studies have been helpful in the development of single crystal diamond for diode applications. Reference materials of Ge and GaAs were used to test the Hall Effect system. The system was also used to characterize polycrystalline diamond deposited on glass for electrochemical applications, and Mg2(Si,Sn) compounds which are promising candidates of low-cost, light weight and non

  9. Design of Residues Measurement Device of Uranium

    Institute of Scientific and Technical Information of China (English)

    SUI; Hong-zhi; XU; Zheng; LU; Wen-guang; HE; Li-xia; GAN; Lin

    2012-01-01

    <正>Nuclear materials will be deposited in the pipeline or various process equipment during the operation of nuclear facilities, such as dissolution reactor, because the recovery residue of uranium not dissolved, and a metal tubularis in the dissolution reactor cannot insert to the bottom of the container, so that part of the residual slag and the solution stored in the bottom of the reactor. When the equipment is used for treatment of nuclear material, it is difficult to put out all the nuclear material in the equipment. Therefore, measurement of these residues for nuclear material accountancy, the safe operation of the facilities,

  10. 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

    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...... 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...... 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...

  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...

  12. Heart rate variability and DNA methylation levels are altered after short-term metal fume exposure among occupational welders: a repeated-measures panel study

    OpenAIRE

    2014-01-01

    Background: In occupational settings, boilermakers are exposed to high levels of metallic fine particulate matter (PM2.5) generated during the welding process. The effect of welding PM2.5 on heart rate variability (HRV) has been described, but the relationship between PM2.5, DNA methylation, and HRV is not known. Methods: In this repeated-measures panel study, we recorded resting HRV and measured DNA methylation levels in transposable elements Alu and long interspersed nuclear element-1 (LINE...

  13. Learning and cognitive fatigue trajectories in multiple sclerosis defined using a burst measurement design.

    Science.gov (United States)

    Holtzer, Roee; Foley, Frederick; D'Orio, Vanessa; Spat, Jessica; Shuman, Melissa; Wang, Cuiling

    2013-10-01

    Compromised learning and cognitive fatigue are critical clinical features in multiple sclerosis. This study was designed to determine the effect of repeated exposures within and across study visits on performance measures of learning and cognitive fatigue in relapsing-remitting multiple sclerosis (RRMS). Thirty patients with RRMS and 30 controls were recruited. Using a burst measurement design (i.e. repeated assessments within and across study visits) the oral version of the Symbol Digit Modalities Test (SDMT) was administered three times during the baseline and two consecutive monthly follow-up visits for a total of nine test administrations. Learning was assessed within and across study visits whereas cognitive fatigue was assessed during the course of each test administration that was divided into three 30-second intervals. Linear mixed-effect models revealed compromised learning within (95% CI: 2.6355 to 3.9867) and across (95% CI: 1.3250 to 3.1861) visits and worse cognitive fatigue (95% CI: -2.1761 to -0.1720) in patients with RRMS compared with controls. Among patients with RRMS, worse self-rated cognitive dysfunction predicted poor learning within (95% CI: -0.1112 to -0.0020) and across (95% CI: -0.0724 to -0.0106) visits. Burst design is optimal to study learning and cognitive fatigue. This methodology, using the SDMT or other time-efficient tests as outcome measures, can be successfully implemented in longitudinal studies and clinical trials.

  14. A technique for conditioning and calibrating force-sensing resistors for repeatable and reliable measurement of compressive force.

    Science.gov (United States)

    Hall, Rick S; Desmoulin, Geoffrey T; Milner, Theodore E

    2008-12-01

    Miniature sensors that could measure forces applied by the fingers and hand without interfering with manual dexterity or range of motion would have considerable practical value in ergonomics and rehabilitation. In this study, techniques have been developed to use inexpensive pressure-sensing resistors (FSRs) to accurately measure compression force. The FSRs are converted from pressure-sensing to force-sensing devices. The effects of nonlinear response properties and dependence on loading history are compensated by signal conditioning and calibration. A fourth-order polynomial relating the applied force to the current voltage output and a linearly weighted sum of prior outputs corrects for sensor hysteresis and drift. It was found that prolonged (>20h) shear force loading caused sensor gain to change by approximately 100%. Shear loading also had the effect of eliminating shear force effects on sensor output, albeit only in the direction of shear loading. By applying prolonged shear loading in two orthogonal directions, the sensors were converted into pure compression sensors. Such preloading of the sensor is, therefore, required prior to calibration. The error in compression force after prolonged shear loading and calibration was consistently industrial design applications where measurements of finger and hand force are needed.

  15. Young investigator challenge: Atypia of undetermined significance in thyroid FNA: Standardized terminology without standardized management--a closer look at repeat FNA and quality measures.

    Science.gov (United States)

    Brandler, Tamar C; Aziz, Mohamed S; Coutsouvelis, Constantinos; Rosen, Lisa; Rafael, Oana C; Souza, Fabiola; Jelloul, Fatima-Zahra; Klein, Melissa A

    2016-01-01

    The Bethesda system (TBS) for the reporting of thyroid cytopathology established the category of atypia of undetermined significance (AUS) with a 7% target rate and a 5% to 15% implied malignancy risk. Recent literature has reported a broad range of AUS rates, subsequent malignancy rates, and discrepant results from repeat fine-needle aspiration (FNA) versus surgical follow-up. Therefore, this study examined AUS data from the Hofstra North Shore-LIJ School of Medicine to determine the best clinical follow-up. Thyroid aspirates interpreted as AUS in 2012-2014 at the Hofstra North Shore-LIJ School of Medicine were collected. Repeat FNA and surgical follow-up data were tabulated to establish AUS, secondary AUS (diagnosed upon repeat FNA follow-up of a primary FNA AUS diagnosis), atypia of undetermined significance/malignancy (AUS:M) ratios (according to the TBS categories), and malignancy rates for AUS. The AUS rate was 8.5% (976/11,481), and there was follow-up data for 545 cases. The AUS:M ratio was 2.0. Repeat FNA was performed for 281 cases; 57 proceeded to surgical intervention. Repeat FNA reclassified 71.17% of the cases. The malignancy rates for AUS cases proceeding directly to surgery and for those receiving a surgical intervention after a repeat AUS diagnosis were 33.33% and 43.75%, respectively. Repeat FNA resulted in definitive diagnostic reclassification for 67.61% of primary AUS cases and reduced the number of patients triaged to surgery, with 56.58% of the cases recategorized as benign. Cases undergoing surgery after repeat AUS had a higher malignancy rate than those going straight to surgery, and this emphasizes the value of repeat FNA in selecting surgical candidates. In addition, this study highlights the utility of AUS rate monitoring as a quality measure that has contributed to the ability of the Hofstra North Shore-LIJ School of Medicine to adhere closely to TBS recommendations. © 2016 American Cancer Society.

  16. The effects of repeated-sprint training on field-based fitness measures: a meta-analysis of controlled and non-controlled trials.

    Science.gov (United States)

    Taylor, Jonathan; Macpherson, Tom; Spears, Iain; Weston, Matthew

    2015-06-01

    Repeated-sprint training appears to be an efficient and practical means for the simultaneous development of different components of fitness relevant to team sports. Our objective was to systematically review the literature and meta-analyse the effect of repeated-sprint training on a selection of field-based measures of athletic performance, i.e. counter-movement jump, 10 m sprint, 20 m sprint, 30 m sprint, repeated-sprint ability and high-intensity intermittent running performance. The SPORTDiscus, PubMed, MEDLINE and Web of Science databases were searched for original research articles. Search terms included 'repeated-sprint training', 'sprint training', 'aerobic endurance', 'repeated-sprint ability', 'counter-movement jump' and 'sprint performance'. Inclusion criteria included intervention consisting of a series of ≤10 s sprints with ≤60 s recovery; trained participants; intervention duration of 2-12 weeks; field-based fitness measures; running- or cycling-based intervention; published up to, and including, February 2014. Our final dataset included six trials for counter-movement jump (two controlled trials), eight trials for 10 m sprint, four trials for 20 m sprint (three controlled trials), two trials for 30 m sprint, eight trials for repeated-sprint ability and three trials for high-intensity intermittent running performance. Analyses were conducted using comprehensive meta-analysis software. Uncertainty in the meta-analysed effect of repeated-sprint training was expressed as 95% confidence limits (CL), along with the probability that the true value of the effect was trivial, beneficial or harmful. Magnitude-based inferences were based on standardised thresholds for small, moderate and large changes of 0.2, 0.6 and 1.2 standard deviations, respectively. Repeated-sprint training had a likely small beneficial effect in non-controlled counter-movement jump trials (effect size 0.33; 95% CL ±0.30), with a possibly moderate beneficial effect in controlled

  17. Effects of repeatability measures on results of fMRI sICA: a study on simulated and real resting-state effects.

    Science.gov (United States)

    Remes, Jukka J; Starck, Tuomo; Nikkinen, Juha; Ollila, Esa; Beckmann, Christian F; Tervonen, Osmo; Kiviniemi, Vesa; Silven, Olli

    2011-05-15

    Spatial independent components analysis (sICA) has become a widely applied data-driven method for fMRI data, especially for resting-state studies. These sICA approaches are often based on iterative estimation algorithms and there are concerns about accuracy due to noise. Repeatability measures such as ICASSO, RAICAR and ARABICA have been introduced as remedies but information on their effects on estimates is limited. The contribution of this study was to provide more of such information and test if the repeatability analyses are necessary. We compared FastICA-based ordinary and repeatability approaches concerning mixing vector estimates. Comparisons included original FastICA, FSL4 Melodic FastICA and original and modified ICASSO. The effects of bootstrapping and convergence threshold were evaluated. The results show that there is only moderate improvement due to repeatability measures and only in the bootstrapping case. Bootstrapping attenuated power from time courses of resting-state network related ICs at frequencies higher than 0.1 Hz and made subsets of low frequency oscillations more emphasized IC-wise. The convergence threshold did not have a significant role concerning the accuracy of estimates. The performance results suggest that repeatability measures or strict converge criteria might not be needed in sICA analyses of fMRI data. Consequently, the results in existing sICA fMRI literature are probably valid in this sense. A decreased accuracy of original bootstrapping ICASSO was observed and corrected by using centrotype mixing estimates but the results warrant for thorough evaluations of data-driven methods in general. Also, given the fMRI-specific considerations, further development of sICA methods is strongly encouraged. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Simulated Conversations With Virtual Humans to Improve Patient-Provider Communication and Reduce Unnecessary Prescriptions for Antibiotics: A Repeated Measure Pilot Study

    Science.gov (United States)

    2017-01-01

    Background Despite clear evidence that antibiotics do not cure viral infections, the problem of unnecessary prescribing of antibiotics in ambulatory care persists, and in some cases, prescribing patterns have increased. The overuse of antibiotics for treating viral infections has created numerous economic and clinical consequences including increased medical costs due to unnecessary hospitalizations, antibiotic resistance, disruption of gut bacteria, and obesity. Recent research has underscored the importance of collaborative patient-provider communication as a means to reduce the high rates of unnecessary prescriptions for antibiotics. However, most patients and providers do not feel prepared to engage in such challenging conversations. Objectives The aim of this pilot study was to assess the ability of a brief 15-min simulated role-play conversation with virtual humans to serve as a preliminary step to help health care providers and patients practice, and learn how to engage in effective conversations about antibiotics overuse. Methods A total of 69 participants (35 providers and 34 patients) completed the simulation once in one sitting. A pre-post repeated measures design was used to assess changes in patients’ and providers’ self-reported communication behaviors, activation, and preparedness, intention, and confidence to effectively communicate in the patient-provider encounter. Changes in patients’ knowledge and beliefs regarding antibiotic use were also evaluated. Results Patients experienced a short-term positive improvement in beliefs about appropriate antibiotic use for infection (F1,30=14.10, P=.001). Knowledge scores regarding the correct uses of antibiotics improved immediately postsimulation, but decreased at the 1-month follow-up (F1,30=31.16, P.10) Patients with lower levels of activation exhibited positive, short-term benefits in increased intent and confidence to discuss their needs and ask questions in the clinic visit, positive attitudes

  19. Revisiting the TALE repeat.

    Science.gov (United States)

    Deng, Dong; Yan, Chuangye; Wu, Jianping; Pan, Xiaojing; Yan, Nieng

    2014-04-01

    Transcription activator-like (TAL) effectors specifically bind to double stranded (ds) DNA through a central domain of tandem repeats. Each TAL effector (TALE) repeat comprises 33-35 amino acids and recognizes one specific DNA base through a highly variable residue at a fixed position in the repeat. Structural studies have revealed the molecular basis of DNA recognition by TALE repeats. Examination of the overall structure reveals that the basic building block of TALE protein, namely a helical hairpin, is one-helix shifted from the previously defined TALE motif. Here we wish to suggest a structure-based re-demarcation of the TALE repeat which starts with the residues that bind to the DNA backbone phosphate and concludes with the base-recognition hyper-variable residue. This new numbering system is consistent with the α-solenoid superfamily to which TALE belongs, and reflects the structural integrity of TAL effectors. In addition, it confers integral number of TALE repeats that matches the number of bound DNA bases. We then present fifteen crystal structures of engineered dHax3 variants in complex with target DNA molecules, which elucidate the structural basis for the recognition of bases adenine (A) and guanine (G) by reported or uncharacterized TALE codes. Finally, we analyzed the sequence-structure correlation of the amino acid residues within a TALE repeat. The structural analyses reported here may advance the mechanistic understanding of TALE proteins and facilitate the design of TALEN with improved affinity and specificity.

  20. Recursive quantum repeater networks

    CERN Document Server

    Van Meter, Rodney; Horsman, Clare

    2011-01-01

    Internet-scale quantum repeater networks will be heterogeneous in physical technology, repeater functionality, and management. The classical control necessary to use the network will therefore face similar issues as Internet data transmission. Many scalability and management problems that arose during the development of the Internet might have been solved in a more uniform fashion, improving flexibility and reducing redundant engineering effort. Quantum repeater network development is currently at the stage where we risk similar duplication when separate systems are combined. We propose a unifying framework that can be used with all existing repeater designs. We introduce the notion of a Quantum Recursive Network Architecture, developed from the emerging classical concept of 'recursive networks', extending recursive mechanisms from a focus on data forwarding to a more general distributed computing request framework. Recursion abstracts independent transit networks as single relay nodes, unifies software layer...

  1. Deployment Repeatability

    Science.gov (United States)

    2016-04-01

    controlled to great precision, but in a Cubesat , there may be no attitude determination at all. Such a Cubesat might treat sun angle and tumbling rates as...could be sensitive to small differences in motor controller timing. In these cases, the analyst might choose to model the entire deployment path, with...knowledge of the material damage model or motor controller timing precision. On the other hand, if many repeated and environmentally representative

  2. A new technique for repeated biopsies of the mammary gland in dairy cows allotted to Latin-square design studies.

    Science.gov (United States)

    de Lima, Luciano S; Martineau, Eric; De Marchi, Francilaine E; Palin, Marie-France; Dos Santos, Geraldo T; Petit, Hélène V

    2016-07-01

    The objective of this study was to develop a technique for carrying out repeated biopsies of the mammary gland of lactating dairy cows that provides enough material to monitor enzyme activities and gene expression in mammary secretory tissue. A total of 16 Holstein cows were subjected to 4 mammary biopsies each at 3-week intervals for a total of 64 biopsies. A 0.75-cm incision was made through the skin and subcutaneous tissue of the mammary gland and a trocar and cannula were inserted using a circular motion. The trocar was withdrawn and a syringe was plugged into the base of the cannula to create a vacuum for sampling mammary tissue. To reduce bleeding, hand pressure was put on the surgery site after biopsy and skin closure and ice was applied for at least 2 h after the biopsy using a cow bra. The entire procedure took an average of 25 min. Two attempts were usually enough to obtain 800 mg of tissue. Visual examination of milk samples 10 d after the biopsy indicated no trace of blood, except in samples from 2 cows. All wounds healed without infection and subcutaneous hematomas resorbed within 7 d. There was no incidence of mastitis throughout the lactation. This technique provides a new tool for biopsy of the mammary gland repeated at short intervals with the main effect being a decrease in milk production. Although secondary complications leading to illness or death are always a risk with any procedure, this biopsy technique was carried out without complications to the health of animals and with no incidence of mastitis during the lactation.

  3. 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

  4. On A Measurement of Designing And Predicate Logic

    OpenAIRE

    谷口, 興紀; タニグチ, オキノリ; Okinori, TANIGUCHI

    1983-01-01

    The background of the study is that the ratio of the time spent in the verbal device in design process is 40% and it is indispensable to use a verbal device to fix the image of the form which a designer intends to build. I tried to measure design-thinking to do such activities for the science of design. Under the hypothesis that we can trace back design-thinking through the form which satisfies requirements and the analysis of the form can be trace back through the analysis of requirements, w...

  5. An evaluation of a structured learning program as a component of the clinical practicum in undergraduate nurse education: A repeated measures analysis.

    Science.gov (United States)

    Watt, Elizabeth; Murphy, Maria; MacDonald, Lee; Pascoe, Elizabeth; Storen, Heather; Scanlon, Andrew

    2016-01-01

    There is evidence that nursing students experience stress and anxiety and a reduction in self-efficacy when undertaking clinical placements. Previous reports have identified that a structured three-day program within the Bachelor of Nursing (BN) clinical practicum reduces the students self-report of anxiety and increases self-efficacy. However, it is unreported whether these improved outcomes are sustained for the duration of the clinical placement. The aim of this study was to evaluate the duration of the effect of a three-day structured learning program within the clinical placement on final year Bachelor of Nursing student's report of anxiety and self-efficacy pre- and post-program participation in this intervention and following completion of the clinical practicum. A repeated measures design. University-based Clinical School of Nursing, acute care clinical practicum. Final year Bachelor of Nursing students. The intervention comprised the three-day program on starting the clinical practicum. A questionnaire included the anxiety subscale of The Hospital Anxiety & Depression Scale (The HAD) and the General Self-Efficacy Scale (GSES-12). The questionnaire was completed on day one (time one), upon completion of the three-day program (time two) and upon completion of placement on day 18 (time three). The questionnaire response rate varied over time. There was a statistically significant effect in reducing anxiety over time: F(1.73,74.46)=25.20, plearning program and the benefit of the intervention is sustained for the clinical placement duration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Which are the most useful scales for predicting repeat self-harm? A systematic review evaluating risk scales using measures of diagnostic accuracy

    Science.gov (United States)

    Quinlivan, L; Cooper, J; Davies, L; Hawton, K; Gunnell, D; Kapur, N

    2016-01-01

    Objectives The aims of this review were to calculate the diagnostic accuracy statistics of risk scales following self-harm and consider which might be the most useful scales in clinical practice. Design Systematic review. Methods We based our search terms on those used in the systematic reviews carried out for the National Institute for Health and Care Excellence self-harm guidelines (2012) and evidence update (2013), and updated the searches through to February 2015 (CINAHL, EMBASE, MEDLINE, and PsychINFO). Methodological quality was assessed and three reviewers extracted data independently. We limited our analysis to cohort studies in adults using the outcome of repeat self-harm or attempted suicide. We calculated diagnostic accuracy statistics including measures of global accuracy. Statistical pooling was not possible due to heterogeneity. Results The eight papers included in the final analysis varied widely according to methodological quality and the content of scales employed. Overall, sensitivity of scales ranged from 6% (95% CI 5% to 6%) to 97% (CI 95% 94% to 98%). The positive predictive value (PPV) ranged from 5% (95% CI 3% to 9%) to 84% (95% CI 80% to 87%). The diagnostic OR ranged from 1.01 (95% CI 0.434 to 2.5) to 16.3 (95%CI 12.5 to 21.4). Scales with high sensitivity tended to have low PPVs. Conclusions It is difficult to be certain which, if any, are the most useful scales for self-harm risk assessment. No scales perform sufficiently well so as to be recommended for routine clinical use. Further robust prospective studies are warranted to evaluate risk scales following an episode of self-harm. Diagnostic accuracy statistics should be considered in relation to the specific service needs, and scales should only be used as an adjunct to assessment. PMID:26873046

  7. Design of High Precision Temperature Measurement System based on Labview

    OpenAIRE

    Weimin Zhu; Jin Liu; Haima Yang; Chaochao Yan

    2015-01-01

    Using the LabVIEW software platform, a high precision temperature measuring device is designed based on the principle of the thermocouple. The system uses the STM32 MCU as the main control chip, using AD7076 analog digital converter. The converter has 8 channel, synchronous sampling, and bipolar input. Improving the precision of temperature measurement by cold end compensation, fitting and other measures. The test results show that, the device temperature measurement precision can reach ±0.1 ...

  8. Design of Customer Satisfaction Measurement Index System of EMS Service

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper discusses the design of a customer satisfaction measurement index system of erpress mail service. It presents objectives and principles of the design based on hierarchical structures. We have devised a diagram for modeling customer satisfaction, and a detailed analysis of customer satisfaction is conducted. This paper presents our customer satisfaction model and analysis results.

  9. Design and realization of random measurement scheme for compressed sensing

    Institute of Scientific and Technical Information of China (English)

    XIE Cheng-jun; XU Lin

    2012-01-01

    Design and realization of random measurement scheme for compressed sensing (CS) are presented in this paper,and lower limits of the measurement number are achieved when the precise reconstruction is realized.Four kinds of random measurement matrices are designed according to the constraint conditions of random measurement.The performance is tested employing the algorithm of stagewise orthogonal matching pursuit (StOMP).Results of the experiment show that lower limits of the measurement number are much better than the results described in Refs.[ 13-15].When the ratios of measurement to sparsity are 3.8 and 4.0,the mean relative errors of the reconstructed signals are 8.57 × 10-13 and 2.43 × 10-14,respectively,which confirms that the random measurement scheme of this paper is very effective.

  10. Repeatability and Reproducibility of Retinal Neuronal and Axonal Measures on Spectral-Domain Optical Coherence Tomography in Patients with Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Edwin Hong-Teck Loh

    2017-08-01

    Full Text Available BackgroundWith increasing interest in determining if measurement of retinal neuronal structure with spectral-domain optical coherence tomography (SD-OCT is useful in accessing neurodegenerative process in cognitive decline and development of dementia, it is important to evaluate whether the SD-OCT measurements are repeatable and reproducible in these patients.MethodsThis is a retrospective cohort study. Patients with Alzheimer’s disease (AD or mild cognitive impairment (MCI with no change in global clinical dementia rating (CDR score at 1-year follow-up were eligible to be included. Ganglion cell-inner plexiform layer (GC-IPL and retinal nerve fiber layer (RNFL parameters were measured with SD-OCT at baseline, 6-month, and 1-year follow-up visits. At baseline, SD-OCT scans were repeated to access intra-visit repeatability of the SD-OCT measurement. SD-OCT measurement over three visits was used to access inter-visit reproducibility. We calculated intraclass correlation coefficients (ICC and coefficients of variation (CoVs.ResultsWe included 32 patients with stable AD and 29 patients with stable MCI in the final analysis. For GC-IPL measures, the average intra-visit ICC was 0.969 (range: 0.948–0.985, and CoV was 1.81% (range: 1.14–2.40; while the average inter-visit ICC was 0.968 (0.941–0.985, and CoV was 1.91% (range: 1.24–2.32. The average ICC and CoV of intra-visit RNFL measured were 0.965 (range: 0.937–0.986 and 2.32% (range: 1.34–2.90%, respectively. The average ICC and CoV of inter-visit RNFL measures were 0.927 (range: 0.845–0.961 and 3.83% (range: 2.71–5.25%, respectively.ConclusionBoth GC-IPL and RNFL measurements had good intra-visit repeatability and inter-visit reproducibility over 1 year in elderly patients with no decline in cognitive function, suggesting that SD-OCT is a reliable tool to assess neurodegenerative process over time.

  11. Design of MEMS accelerometer based acceleration measurement system for automobiles

    Science.gov (United States)

    Venkatesh, K. Arun; Mathivanan, N.

    2012-10-01

    Design of an acceleration measurement system using a MEMS accelerometer to measure acceleration of automobiles in all the three axes is presented. Electronic stability control and anti-lock breaking systems in automobiles use the acceleration measurements to offer safety in driving. The system uses an ARM microcontroller to quantize the outputs of accelerometer and save the measurement data on a microSD card. A LabVIEW program has been developed to analyze the longitudinal acceleration measurement data and test the measurement system. Random noises generated and added with measurement data during measurement are filtered by a Kalman filter implemented in LabVIEW. Longitudinal velocity of the vehicle is computed from the measurement data and displayed on a graphical chart. Typical measurement of velocity of a vehicle at different accelerations and decelerations is presented.

  12. Investigation of a design performance measurement tool for improving collaborative design during a design process

    OpenAIRE

    Yin, Yuanyuan

    2009-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. With rapid growth of global competition, the design process is becoming more and more complex due largely to cross-functional team collaboration, dynamic design processes, and unpredictable design outcomes. Thus, it is becoming progressively more difficult to support and improve design activities effectively during a design process, especially from a collaboration perspective. Although a grea...

  13. Design and analysis of post-fusion 6-helix bundle of heptad repeat regions from Newcastle disease virus F protein.

    Science.gov (United States)

    Zhu, Jieqing; Li, Pengyun; Wu, Tinghe; Gao, Feng; Ding, Yi; Zhang, Catherine W-H; Rao, Zihe; Gao, George F; Tien, Po

    2003-05-01

    Fusion of paramyxovirus to the cell involves receptor binding of the HN glycoprotein and a number of conformational changes of F glycoprotein. The F protein is expressed as a homotrimer on the virus surface. In the present model, there are at least three conformations of F protein, i.e. native form, pre-hairpin intermediate and the post-fusion state. In the post-fusion state, the two highly conserved heptad repeat (HR) regions of F protein form a stable 6-helix coiled-coil bundle. However, no crystal structure is known for this state for the Newcastle disease virus, although the crystal structure of the F protein native form has been solved recently. Here we deployed an Escherichia coli in vitro expression system to engineer this 6-helix bundle by fusion of either the two HR regions (HR1, linker and HR2) or linking the 6-helix [3 x (HR1, linker and HR2)] together as a single chain. Subsequently, both of them form a stable 6-helix bundle in vitro judging by gel filtration and chemical cross-linking and the proteins show salient features of an alpha-helix structure. Crystals diffracting X-rays have been obtained from both protein preparations and the structure determination is under way. This method could be used for crystallization of the post-fusion state HR structures of other viruses.

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

    Directory of Open Access Journals (Sweden)

    Mirian Ara

    2015-01-01

    Full Text Available Objective. 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. Methods. 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. Results. 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. Conclusions. The reproducibility of peripapillary RNFL measurements obtained with SLP-ECC was excellent, indicating that SLP-ECC is sufficiently accurate for monitoring glaucoma progression.

  15. 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.

  16. 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 T1-weighted images (3D-T1WIs) 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.

  17. Design techniques for large scale linear measurement systems

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J.V.

    1979-03-01

    Techniques to design measurement schemes for systems modeled by large scale linear time invariant systems, i.e., physical systems modeled by a large number (> 5) of ordinary differential equations, are described. The techniques are based on transforming the physical system model to a coordinate system facilitating the design and then transforming back to the original coordinates. An example of a three-stage, four-species, extraction column used in the reprocessing of spent nuclear fuel elements is presented. The basic ideas are briefly discussed in the case of noisy measurements. An example using a plutonium nitrate storage vessel (reprocessing) with measurement uncertainty is also presented.

  18. Design of High Precision Temperature Measurement System based on Labview

    Directory of Open Access Journals (Sweden)

    Weimin Zhu

    2015-06-01

    Full Text Available Using the LabVIEW software platform, a high precision temperature measuring device is designed based on the principle of the thermocouple. The system uses the STM32 MCU as the main control chip, using AD7076 analog digital converter. The converter has 8 channel, synchronous sampling, and bipolar input. Improving the precision of temperature measurement by cold end compensation, fitting and other measures. The test results show that, the device temperature measurement precision can reach ±0.1 °C, has the advantages of small size, high precision, and reliable performance, this high precision temperature measurement can be widely used in industrial production.

  19. METHODS FOR MEASURING CUSTOMER SATISFACTION IN THE DESIGN PROCESS

    Directory of Open Access Journals (Sweden)

    Mirko Đapic

    2007-09-01

    Full Text Available In the design process, the designer makes decisions under uncertainty, contradiction and ignorance conditions. Are these decisions correct and to what extent? How much do they influence customer's satisfaction? These are only some of the questions the designers face all time. These dilemmas appear more in early phases of the design process. The explicit objectives of this paper is improvement of design decision making process in such a way that in same time when designer made a decision he or she show result that decision on customer satisfaction. In order to solve above problems, the paper describes the method, which enables integrated use of the axiomatic approach to designing, and the Taguchi method of robust design. This approach implies the modelling of the development process as an evidence-reasoning network based on uncertain evidence described via belief functions of (Dempster - Shafer theory. The paper starts with base concept of belief functions and valuation based system or evidential reasoning system for representation and reasoning based on uncertainty. After that we introduce coefficient of relative decrease of uncertainty in design process and new graphical representation of system architecture - the evidence networks. On the end we presents a method for measuring customer satisfaction in the design process in uncertainty condition using evidence networks.

  20. FIRE - Flyby of Io with Repeat Encounters: A conceptual design for a New Frontiers mission to Io

    Science.gov (United States)

    Suer, Terry-Ann; Padovan, Sebastiano; Whitten, Jennifer L.; Potter, Ross W. K.; Shkolyar, Svetlana; Cable, Morgan; Walker, Catherine; Szalay, Jamey; Parker, Charles; Cumbers, John; Gentry, Diana; Harrison, Tanya; Naidu, Shantanu; Trammell, Harold J.; Reimuller, Jason; Budney, Charles J.; Lowes, Leslie L.

    2017-09-01

    A conceptual design is presented for a low complexity, heritage-based flyby mission to Io, Jupiter's innermost Galilean satellite and the most volcanically active body in the Solar System. The design addresses the 2011 Decadal Survey's recommendation for a New Frontiers class mission to Io and is based upon the result of the June 2012 NASA-JPL Planetary Science Summer School. A science payload is proposed to investigate the link between the structure of Io's interior, its volcanic activity, its surface composition, and its tectonics. A study of Io's atmospheric processes and Io's role in the Jovian magnetosphere is also planned. The instrument suite includes a visible/near-IR imager, a magnetic field and plasma suite, a dust analyzer, and a gimbaled high gain antenna to perform radio science. Payload activity and spacecraft operations would be powered by three Advanced Stirling Radioisotope Generators (ASRG). The primary mission includes 10 flybys with close-encounter altitudes as low as 100 km. The mission risks are mitigated by ensuring that relevant components are radiation tolerant and by using redundancy and flight-proven parts in the design. The spacecraft would be launched on an Atlas V rocket with a delta-v of 1.3 km/s. Three gravity assists (Venus, Earth, Earth) would be used to reach the Jupiter system in a 6-year cruise. The resulting concept demonstrates the rich scientific return of a flyby mission to Io.

  1. Repeated-Sprint Cycling Does Not Induce Respiratory Muscle Fatigue in Active Adults: Measurements from The Powerbreathe® Inspiratory Muscle Trainer

    Directory of Open Access Journals (Sweden)

    Clare Minahan, Beth Sheehan, Rachel Doutreband, Tom Kirkwood, Daniel Reeves, Troy Cross

    2015-03-01

    Full Text Available This study examined respiratory muscle strength using the POWERbreathe® inspiratory muscle trainer (i.e., ‘S-Index’ before and after repeated-sprint cycling for comparison with maximal inspiratory pressure (MIP values obtained during a Mueller maneuver. The S-Index was measured during six trials across two sessions using the POWERbreathe® and MIP was measured during three trials in a single session using a custom-made manometer in seven recreationally active adults. Global respiratory muscle strength was measured using both devices before and after the performance of sixteen, 6-s sprints on a cycle ergometer. Intraclass correlation coefficients for the POWERbreathe® S-index indicated excellent (p 0.99 and during the Mueller maneuver (p > 0.99. The POWERbreathe® S-Index is a moderately reliable, but not equivalent, measure of MIP determined during a Mueller maneuver. Furthermore, repeated-sprint cycling does not induce globalized respiratory muscle fatigue in recreationally-active adults.

  2. Repeatability of measurements of packed cell volume and egg count as indicators of endoparasite load and their relationship with sheep productivity.

    Science.gov (United States)

    Bekele, T; Kasali, O B; Rege, J E

    1991-12-01

    Monthly measurements of packed cell volume (PCV) and nematode and trematode eggs per gram (EPG) were made in Ethiopian highland sheep at Debre Berhan, Dejen, Deneba, Tulu Meko and Wereilu from June 1988 to December 1989. High frequencies of low PCV, high nematode EPG and high trematode EPG were found at Tulu Meko. Among the productivity traits examined, body condition scores and live-weights were significantly (P less than 0.05) associated with differences in PCV and nematode and trematode EPG levels at most sites. The lambing interval was, however, not significantly (P greater than 0.05) affected by these variables. Monthly repeatabilities of PCV, body weight and body condition scores were 0.44 +/- 0.01, 0.71 +/- 0.01 and 0.35 +/- 0.01, respectively, while those of nematode (0.09 +/- 0.01) and trematode EPGs (0.20 +/- 0.02) were much lower. The high repeatability for PCV indicates that it was less affected by the variable factors influencing egg output, and hence it could be utilized in conjunction with nematode and trematode EPG levels for endoparasite monitoring. Repeatability of the lambing interval across parities was 0.43 +/- 0.14.

  3. 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

  4. Thermocouple design for measuring temperatures of small insects.

    Science.gov (United States)

    Hanson, A A; Venette, R C

    2013-01-01

    Contact thermocouples often are used to measure surface body temperature changes of insects during cold exposure. However, small temperature changes of minute insects can be difficult to detect, particularly during the measurement of supercooling points. We developed two thermocouple designs, which use 0.51 mm diameter or 0.127 mm diameter copper-constantan wires, to improve our ability to resolve insect exotherms. We tested the designs with adults from three parasitoid species: Tetrastichus planipennisi, Spathius agrili, and S. floridanus. These species are thermocouples than thick-gauge thermocouples for the smallest species tested, T. planipennisi. This difference was not apparent for larger species S. agrili and S. floridanus. Thermocouple design did not affect the mean supercooling point for any of the species. The cradle thermocouple design developed with the fine gauge wire was reusable and allowed for easy insect recovery after cold exposure.

  5. The design and implementation of the AVNG measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Macarthur, Duncan W [Los Alamos National Laboratory; Thron, Jonathan [Los Alamos National Laboratory; Razinkov, Sergey [RFNC-VNIIEF; Livke, Alexander [RFNC-VNIIEF; Kondratov, Sergey [RFNC-VNIIEF

    2010-01-01

    An attribute measurement system (AMS) measures a number of unclassified attributes of potentially classified material. By displaying these unclassified results only as red or green lights, the AMS protects potentially classified information while still generating confidence in the measurement result. The AVNG that we describe is an AMS built by RFNC-VNIIEF in Sarov, Russia. The AVNG detects neutron and gamma radiation signatures and displays the three unclassified attributes of 'plutonium presence,' 'plutonium mass >2 kg,' and 'plutonium isotopic ratio ({sup 240}Pu to {sup 239}Pu) < 0.1.' In this presentation, we will describe the design of the AVNG neutron and gamma detector subsystems, as well as the design of the entire AMS incorporating these detectors. We will also describe the construction of the AVNG and the final design that was demonstrated in June 2009.

  6. Improvement of LysM-mediated surface display of designed ankyrin repeat proteins (DARPins) in recombinant and nonrecombinant strains of Lactococcus lactis and Lactobacillus Species.

    Science.gov (United States)

    Zadravec, Petra; Štrukelj, Borut; Berlec, Aleš

    2015-03-01

    Safety and probiotic properties make lactic acid bacteria (LAB) attractive hosts for surface display of heterologous proteins. Protein display on nonrecombinant microorganisms is preferred for therapeutic and food applications due to regulatory requirements. We displayed two designed ankyrin repeat proteins (DARPins), each possessing affinity for the Fc region of human IgG, on the surface of Lactococcus lactis by fusing them to the Usp45 secretion signal and to the peptidoglycan-binding C terminus of AcmA, containing lysine motif (LysM) repeats. Growth medium containing a secreted fusion protein was used to test its heterologous binding to 10 strains of species of the genus Lactobacillus, using flow cytometry, whole-cell enzyme-linked immunosorbent assay (ELISA), and fluorescence microscopy. The fusion proteins bound to the surfaces of all lactobacilli; however, binding to the majority of bacteria was only 2- to 5-fold stronger than that of the control. Lactobacillus salivarius ATCC 11741 demonstrated exceptionally strong binding (32- to 55-fold higher than that of the control) and may therefore be an attractive host for nonrecombinant surface display. Genomic comparison of the species indicated the exopolysaccharides of Lb. salivarius as a possible reason for the difference. Additionally, a 15-fold concentration-dependent increase in nonrecombinant surface display on L. lactis was demonstrated by growing bacteria with sublethal concentrations of the antibiotics chloramphenicol and erythromycin. Nonrecombinant surface display on LAB, based on LysM repeats, was optimized by selecting Lactobacillus salivarius ATCC 11741 as the optimal host and by introducing antibiotics as additives for increasing surface display on L. lactis. Additionally, effective display of DARPins on the surfaces of nonrecombinant LAB has opened up several new therapeutic possibilities. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Repeated passive stretching : Acute effect on the passive muscle moment and extensibility of short hamstrings

    NARCIS (Netherlands)

    Halbertsma, JPK; Mulder, [No Value; Goeken, LNH; Eisma, WH; Mulder, I.; Göeken, L.N.

    1999-01-01

    Objective: To examine the response of short hamstring muscles to repeated passive stretching. Design: A repeated measures design. Setting: A university laboratory for human movement analysis in a department of rehabilitation. Subjects: Students (7 men, 10 women) from the Department of Human Movement

  8. Design of Long Distance Repeater Module Based on LVDS%基于LVDS的远程中继模块设计

    Institute of Scientific and Technical Information of China (English)

    陈昱同; 罗贵隆

    2013-01-01

      针对LVDS数据传输在实际应用时可能出现的信号衰减问题,介绍了一种适用于各种逻辑控制的中继模块,该模块可对衰减后的信号进行有效恢复。讨论了中继模块的组成结构及关键技术,并且给出了中继模块的主要设计参数及降噪方法。%To the signal attenuation problem in practical application of LVDS data transmission ,a repeater module is introduced in this paper ,which is applicable to various kinds of logical control and can recover the signal after attenuating effectively .The components of repeater module and key technology are discussed ,and the main design parameters and noise reduction methods are given .

  9. Expressed Sequence Tags Analysis and Design of Simple Sequence Repeats Markers from a Full-Length cDNA Library in Perilla frutescens (L.

    Directory of Open Access Journals (Sweden)

    Eun Soo Seong

    2015-01-01

    Full Text Available Perilla frutescens is valuable as a medicinal plant as well as a natural medicine and functional food. However, comparative genomics analyses of P. frutescens are limited due to a lack of gene annotations and characterization. A full-length cDNA library from P. frutescens leaves was constructed to identify functional gene clusters and probable EST-SSR markers via analysis of 1,056 expressed sequence tags. Unigene assembly was performed using basic local alignment search tool (BLAST homology searches and annotated Gene Ontology (GO. A total of 18 simple sequence repeats (SSRs were designed as primer pairs. This study is the first to report comparative genomics and EST-SSR markers from P. frutescens will help gene discovery and provide an important source for functional genomics and molecular genetic research in this interesting medicinal plant.

  10. Representing Targets of Measurement within Evidence-Centered Design

    Science.gov (United States)

    Ewing, Maureen; Packman, Sheryl; Hamen, Cynthia; Thurber, Allison Clark

    2010-01-01

    In the last few years, the Advanced Placement (AP) Program[R] has used evidence-centered assessment design (ECD) to articulate the knowledge, skills, and abilities to be taught in the course and measured on the summative exam for four science courses, three history courses, and six world language courses; its application to calculus and English…

  11. Determination of design axle loads for bridges from measurements

    NARCIS (Netherlands)

    Steenbergen, R.D.J.M.; Morales Napoles, O.

    2010-01-01

    Recently, the new Eurocode 1 was introduced dealing with traffic load on bridges. In order to establish the National Annex for the design traffic load, measurements of the traffic load were carried out in several highways in The Netherlands using the Weigh In Motion system. The goal was to assure

  12. Determination of design axle loads for bridges from measurements

    NARCIS (Netherlands)

    Steenbergen, R.D.J.M.; Morales Napoles, O.

    2010-01-01

    Recently, the new Eurocode 1 was introduced dealing with traffic load on bridges. In order to establish the National Annex for the design traffic load, measurements of the traffic load were carried out in several highways in The Netherlands using the Weigh In Motion system. The goal was to assure th

  13. Design and Measurement of Metallic Post-Wall Waveguide Components

    NARCIS (Netherlands)

    Coenen, T.J.; Bekers, D.J.; Tauritz, J.L.; Vliet, F.E. van

    2009-01-01

    Abstract—In this paper we discuss the design and measurement of a set of metallic post-wall waveguide components for antenna feed structures. The components are manufactured on a single layer printed circuit board and excited by a grounded coplanar waveguide. For a straight transmission line, a 90°

  14. Anthropometric measurements for ergonomic design of students’ furniture in India

    Directory of Open Access Journals (Sweden)

    Ismail Wilson Taifa

    2017-02-01

    Full Text Available This paper presents anthropometric measurements regarding engineering students in India. Health survey (ergonomic assessment was carried out to know the health status of all students who have been using poorly designed furniture. The data were measured with the help of various tools. After data collection and analysis, authors came up with exhaustive dimensions for designing adjustable classrooms furniture. Dimensions recommended include; bench surface height, bench depth and width, back rest width and height, backrest angle, desk height, desk depth, width, and desk angle. Therefore, an implementation of these data will help to create comfortability, safety, well-being, suitability, reduce Musculoskeletal disorders, and improve performance of students in terms of attentiveness. Also, it is highly recommended to consider requirements from students in designing classrooms furniture and conduct seminar or workshop to educate students regarding the negative impact towards adapting poor posture in the long usage of classrooms furniture.

  15. Variation in repeated mouth-opening measurements in head and neck cancer patients with and without trismus

    NARCIS (Netherlands)

    Jager-Wittenaar, H.; Dijkstra, P. U.; Vissink, A.; van Oort, R. P.; Roodenburg, J. L. N.

    2009-01-01

    Trismus after head and neck cancer treatment may severely limit mandibular functioning. Interventions aimed at reducing trismus can only be evaluated when the amount of variation associated with these measurements is known. The aim of this Study was to analyse the variation in mouth-opening measurem

  16. Repeated measurements of mite and pet allergen levels in house dust over a time period of 8 years

    NARCIS (Netherlands)

    Antens, C. J. M.; Oldenwening, M.; Wolse, A.; Gehring, U.; Smit, H. A.; Aalberse, R. C.; Kerkhof, M.; Gerritsen, J.; de Jongste, J. C.; Brunekreef, B.

    2006-01-01

    Background Studies of the association between indoor allergen exposure and the development of allergic diseases have often measured allergen exposure at one point in time. Objective We investigated the variability of house dust mite (Der p 1, Der f 1) and cat (Fel d 1) allergen in Dutch homes over a

  17. Variation in repeated mouth-opening measurements in head and neck cancer patients with and without trismus

    NARCIS (Netherlands)

    Jager-Wittenaar, H.; Dijkstra, P. U.; Vissink, A.; van Oort, R. P.; Roodenburg, J. L. N.

    2009-01-01

    Trismus after head and neck cancer treatment may severely limit mandibular functioning. Interventions aimed at reducing trismus can only be evaluated when the amount of variation associated with these measurements is known. The aim of this Study was to analyse the variation in mouth-opening measurem

  18. Variation in repeated mouth-opening measurements in head and neck cancer patients with and without trismus

    NARCIS (Netherlands)

    Jager-Wittenaar, H.; Dijkstra, P. U.; Vissink, A.; van Oort, R. P.; Roodenburg, J. L. N.

    Trismus after head and neck cancer treatment may severely limit mandibular functioning. Interventions aimed at reducing trismus can only be evaluated when the amount of variation associated with these measurements is known. The aim of this Study was to analyse the variation in mouth-opening

  19. Repeated measurements of mite and pet allergen levels in house dust over a time period of 8 years

    NARCIS (Netherlands)

    Antens, C. J. M.; Oldenwening, M.; Wolse, A.; Gehring, U.; Smit, H. A.; Aalberse, R. C.; Kerkhof, M.; Gerritsen, J.; de Jongste, J. C.; Brunekreef, B.

    2006-01-01

    Background Studies of the association between indoor allergen exposure and the development of allergic diseases have often measured allergen exposure at one point in time. Objective We investigated the variability of house dust mite (Der p 1, Der f 1) and cat (Fel d 1) allergen in Dutch homes over a

  20. Does a lack of design and repeatability compromise scientific criticism? A Response to Smith et al. (2009)

    Science.gov (United States)

    Wunder, Michael B.; Hobson, Keith A.; Kelly, Jeff; Marra, Peter P.; Wassenaar, Leonard I; Stricker, Craig A.; Doucett, Richard R.

    2009-01-01

    In a recent paper published in The Auk, Smith et al. (2009) raised serious concerns over an apparent lack of reproducibility in their study of stable hydrogen isotope values (δDf ) in raptor feathers. The authors based their concerns on results obtained from different laboratories to which they submitted original and blind “repeats” over a multiyear period. A regression of the original sample δD versus “repeat” measurements showed an increase in the magnitude of residuals with increasing δDf , especially for values greater than about −80‰ (Smith et al. 2009: fig. 2). Because of this, the authors “caution against the continued use of δDf for predicting geographic origin, and for addressing important conservation questions” (p. 41) and conclude that “it is counterproductive to move forward [with hydrogen isotopes in avian studies] without first establishing full confidence in the technique that underlies such insights and conservation recommendations” (p. 45). We disagree with these sentiments.

  1. Design and calibration of the AWCC for measuring uranium hexafluoride

    Energy Technology Data Exchange (ETDEWEB)

    Wenz, T.R.; Menlove, H.O.; WSalton, G.; Baca, J.

    1995-08-01

    An Active Well Coincidence Counter (AWCC) has been modified to measure variable enrichment uranium hexafluoride (UF{sub 6}) in storage bottles. An active assay technique was used to measure the {sup 235}U content because of the small quantity (nominal loading of 2 kg UF{sub 6}) and nonuniform distribution of UF{sub 6} in the storage bottles. A new insert was designed for the AWCC composed of graphite containing four americium-lithium sources. Monte Carlo calculations were used to design the insert and to calibrate the detector. Benchmark measurements and calculations were performed using uranium oxide resulted in assay values that agreed within 2 to 3% of destructive assay values. In addition to UF{sub 6}, the detector was also calibrated for HEU ingots, billets, and alloy scrap using the standard Mode 1 end-plug configuration.

  2. Effects of ambient air pollution on functional status in patients with chronic congestive heart failure: a repeated-measures study

    Directory of Open Access Journals (Sweden)

    Phillips Russell S

    2007-09-01

    Full Text Available Abstract Background Studies using administrative data report a positive association between ambient air pollution and the risk of hospitalization for congestive heart failure (HF. Circulating levels of B-type natriuretic peptide (BNP are directly associated with cardiac hemodynamics and symptom severity in patients with HF and, therefore, serves as a marker of functional status. We tested the hypothesis that BNP levels would be positively associated with short-term changes in ambient pollution levels among 28 patients with chronic stable HF and impaired systolic function. Methods BNP was measured in whole blood at 0, 6, and 12 weeks. We used linear mixed models to evaluate the association between fine particulate matter (PM2.5, carbon monoxide, sulfur dioxide, nitrogen dioxide, ozone, and black carbon and log(BNP. Lags of 0 to 3 days were considered in separate models. We calculated the intraclass correlation coefficient and within-subject coefficient of variation as measures of reproducibility. Results We found no association between any pollutant and measures of BNP at any lag. For example, a 10 μg/m3 increase in PM2.5 was associated with a 0.8% (95% CI: -16.4, 21.5; p = 0.94 increase in BNP on the same day. The within-subject coefficient of variation was 45% on the natural scale and 9% on the log scale. Conclusion These results suggest that serial BNP measurements are unlikely to be useful in a longitudinal study of air pollution-related acute health effects. The magnitude of expected ambient air pollution health effects appears small in relation to the considerable within-person variability in BNP levels in this population.

  3. Design and research on inverted focometer measured focal length of measuring system

    Science.gov (United States)

    Tong, Yilin; Han, Xuecai

    2016-10-01

    Inverted focometer is a transformation of the traditional focomete, and optical lens focal length is an important technical indicators of optical system.The inverted focometer was used to measure the optical lens focal length, an expression between the ruling span of poroo-plate glass and the focal length of measured optical system was deduced according to inverted focometer design, the S-F figure graphic representation was developed , the S-F graph which could express relation of data was obtained, and steps of designing poroo-plate glass were analyzed .The S-F figure graphic representation is simple, intuitive and easy to design.

  4. 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...... body mass index (BMI) and CRP with all-cause mortality and CVD. Being overweight (≥25-obese (≥30-....79-0.94) and 0.80 (0.72-0.89). A similar relationship was found, but only for overweight in Glostrup, HR (95 % CI) 0.88 (0.76-1.02); and moderately obese in Tromsø, HR (95 % CI) 0.79 (0.62-1.01). Associations were not evident between repeated measures of BMI and CVD. Conversely, increasing CRP concentrations...

  5. Designing Information Measures for Real-time Lightcurve Classification

    Science.gov (United States)

    Jones, David Edward; Chen, Yang; Meng, Xiao-Li; Siemiginowska, Aneta; Kashyap, Vinay

    2016-01-01

    Since telescope time is limited, real-time lightcurve classification involves carefully selecting future time points at which sources must be observed in order to maximize the information that will be gained for classification. We propose a framework for constructing measures of information for testing/classification/model-selection and demonstrate their use in experimental design. Degroot (1962) developed a general framework for constructing Bayesian measures of the expected information that an experiment will provide for estimation, and our framework analogously constructs measures of information for hypothesis testing. Such test information measures are most useful for model selection and classification problems. Indeed, our framework suggests a probability based measure of test information, which in decision problems has more appealing properties than variance based measures. In the case of lightcurve classification, we adapt our designs to penalize long waits until the next observation time. Lastly, we consider ways to address other aspects of the problem, such as uncertainty estimation arising due to contamination from nearby contaminating sources or background diffuse emission. We acknowledge support from Smithsonian Competitive Grants Fund 40488100HH0043 and NSF grant DMS 1208791.

  6. Designing a 3rd generation, authenticatable attribute measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Thron, Jonathan [Los Alamos National Laboratory; Karpius, Peter [Los Alamos National Laboratory; Santi, Peter [Los Alamos National Laboratory; Smith, Morag [Los Alamos National Laboratory; Vo, Duc [Los Alamos National Laboratory; Williams, Richard [Los Alamos National Laboratory

    2009-01-01

    Attribute measurement systems (AMS) are designed to measure potentially sensitive items containing Special Nuclear Materials to determine if the items possess attributes which fall within an agreed-upon range. Such systems could be used in a treaty to inspect and verify the identity of items in storage without revealing any sensitive information associated with the item. An AMS needs to satisfy two constraints: the host party needs to be sure that none of their sensitive information is released, while the inspecting party wants to have confidence that the limited amount of information they see accurately reflects the properties of the item being measured. The former involves 'certifying' the system and the latter 'authenticating' it. Previous work into designing and building AMS systems have focused more on the questions of certifiability than on the questions of authentication - although a few approaches have been investigated. The next step is to build a 3rd generation AMS which (1) makes the appropriate measurements, (2) can be certified, and (3) can be authenticated (the three generations). This paper will discuss the ideas, options, and process of producing a design for a 3rd generation AMS.

  7. Design and characterization of novel all-solid-state potentiometric sensor array dedicated to physiological measurements.

    Science.gov (United States)

    Toczyłowska-Mamińska, Renata; Kloch, Monika; Zawistowska-Deniziak, Anna; Bala, Agnieszka

    2016-10-01

    A novel construction of all-solid-state potentiometric sensor array designed for physiological measurements has been presented. The planar construction and elimination of liquid phase creates broad opportunities for the modifications in the sensing part of the sensor. The designed construction is based on all-solid-state ion-selective electrodes integrated with the ionic-liquid based reference electrode. Work parameters of the sensor arrays were characterized. It has been shown that presented sensor design indicates high sensitivity (55.2±1mV/dec, 56.3±2mV/dec, 58.4±1mV/dec and 53.5±1mV/pH for sodium-, potassium-, chloride- and pH-selective electrodes, respectively in 10(-5)-10(-1.5)M range of primary ions), low response time (t95 did not exceed 10s), high potential stability (potential drift in 28-h measurement was ca. ±2mV) and potential repeatability ca. ±1mV. The system was successfully applied to the simultaneous determination of K(+), Cl(-), Na(+) and pH in the model physiological solution and for the ion flux studies in human colon epithelium Caco-2 cell line as well.

  8. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  9. System design of welding dynamic displacement measurement using laser ESPI

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the advantages of electronic speckle pattern interferometry(ESPI), such as non-contact, high precision, strong parasitic light resistance, and full-field measurement, a system for measuring welding dynamic displacement fields using ESPI was designed. The system consists of a 70mW He-Ne laser source, an optical path system, a computer-assisted frame grabber and a processing system. By measuring dynamic displacement fields on one LY2 aluminum alloy plate during an argon arc point welding, it can be proved that using ESPI to measure welding dynamic displacement fields is fully feasible, and this method can offer a solid experimental base for the structure mechanics.

  10. Design of psychosocial factors questionnaires: a systematic measurement approach.

    Science.gov (United States)

    Villalobos, Gloria H; Vargas, Angélica M; Rondón, Martin A; Felknor, Sarah A

    2013-01-01

    Evaluation of psychosocial factors requires instruments that measure dynamic complexities. This study explains the design of a set of questionnaires to evaluate work and non-work psychosocial risk factors for stress-related illnesses. The measurement model was based on a review of literature. Content validity was performed by experts and cognitive interviews. Pilot testing was carried out with a convenience sample of 132 workers. Cronbach's alpha evaluated internal consistency and concurrent validity was estimated by Spearman correlation coefficients. Three questionnaires were constructed to evaluate exposure to work and non-work risk factors. Content validity improved the questionnaires coherence with the measurement model. Internal consistency was adequate (α = 0.85-0.95). Concurrent validity resulted in moderate correlations of psychosocial factors with stress symptoms. Questionnaires' content reflected a wide spectrum of psychosocial factors sources. Cognitive interviews improved understanding of questions and dimensions. The structure of the measurement model was confirmed. Copyright © 2012 Wiley Periodicals, Inc.

  11. Design of multi-spectrum BRDF measurement system

    Institute of Scientific and Technical Information of China (English)

    Zhongyi Zhao; Chao Qi; Jingmin Dai

    2007-01-01

    A multi-spectrum bidirectional reflectance distribution function (BRDF) measurement system was developed with the adoption of single reference standard measurement method. An arm-adjustable corner device was designed for the BRDF system. Changing the distance to the sample by moving the detector arm made the device applicable to different wavelengths. The system could be used for the spectrum range from visible light (0.6328 μm) to mid-far infrared (10.6 μm), the facular size between 0.8-3 cm.The rotating limit of detector arm was ±180°, the rotation range of sample holding table was 360°, and the angle resolution was 0.036°. A silicon carbide sample was measured using this system with reflectance zenith from -55° to +55°. According to the error analysis, the measurement uncertainty of this device was about 6.42%.

  12. Repeated-measure validation of craniofacial metrics from three-dimensional surface scans: application to medical genetics

    Science.gov (United States)

    Lauer, Eric A.; Corner, Brian D.; Li, Peng; Beecher, Robert M.; Deutsch, Curtis

    2002-03-01

    Traditionally, medical geneticists have employed visual inspection (anthroposcopy) to clinically evaluate dysmorphology. In the last 20 years, there has been an increasing trend towards quantitative assessment to render diagnosis of anomalies more objective and reliable. These methods have focused on direct anthropometry, using a combination of classical physical anthropology tools and new instruments tailor-made to describe craniofacial morphometry. These methods are painstaking and require that the patient remain still for extended periods of time. Most recently, semiautomated techniques (e.g., structured light scanning) have been developed to capture the geometry of the face in a matter of seconds. In this paper, we establish that direct anthropometry and structured light scanning yield reliable measurements, with remarkably high levels of inter-rater and intra-rater reliability, as well as validity (contrasting the two methods).

  13. Optimization design of independent photovoltaic supply system for CDMA repeaters%CDMA直放站独立光伏供电系统的优化设计

    Institute of Scientific and Technical Information of China (English)

    陈正武; 苏成仁; 胡芳林; 梁盛德

    2011-01-01

    Solar photovoltaic was adopted to provide electricity to repeaters away from urban, which could not only save energy and protect environment, but also avoid the inconvenience to set electric wires from dozens of miles away and reduce the cost. With solar energy as an independent power supply system, the principle problem was to optimize the design of the system: the best installation angle of the solar panel, the appropriate power of the solar panel to fit a certain power appliance, the capacity of the battery according to the system design requirements, choosing the relevant charge-discharge controller, and etc.. In order to avoid configuration waste and guarantee the system work correctly according to the design requirements, a concise algorithm was introduced, which could reach the optimization design.%用太阳能光伏给远离市区的直放站提供电能,不但节约能源、清洁,而且便捷,不需要从数十里远的地方架设电线,有利于保护环境,减少投资.用太阳能光伏作为独立供电系统,首先要解决的是系统的最优设计问题:太阳电池板安装的最佳倾角;对-定功率的用电器配多大功率的太阳电池板;按照系统设计的工作要求如何配套电瓶的容量;选择相应的充电放电控制器等.既要使系统避免配置浪费,又要使系统能按设计要求保证工作.用简捷的运算方法达到了优化设计的结果.

  14. Iron Dominated Electromagnets: Design, Fabrication, Assembly and Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Jack; /SLAC, SSRL

    2005-09-19

    this same course, and organizes the material roughly divided among two parts. One part is theoretical and computational and attempts to provide a foundation for later chapters which exploit the expressions and algorithms for the engineering and design calculations required to specify magnet conceptual designs. A chapter is devoted to the description and use of one of many magnet codes used to characterize the two dimensional field resulting from various magnet cross-sections. A chapter is included which exploits the two-dimensional theory and applies the mathematics to techniques and systems for magnet measurement. The second part of this publication ranges to practical issues associated with the fabrication of components, assembly, installation and alignment of magnets. This section also includes fabrication practices which respond to personnel and equipment protection needs. Required design calculations are supplemented by examples and problems. A CD is included with tools provided to simplify the computation of some of the more tedious relationships. This CD also includes useful photographs and pictures describing the high volume production of typical magnet types, which if included in the publication will add too many pages and increase the cost of publication. Styles among those facing similar problems will result in a wide variation of individual magnet designs. Designs and technologies will evolve and improve. This publication provides a snapshot of the present technology and presents as examples the magnet designs developed in response to the needs of several projects, the Advanced Light Source at LBNL, PEPII Low Energy Ring and SPEAR3 synchrotron light source at SLAC and the Australian Light Source, currently under construction in Melbourne. In each example, the reasons for fabrication design decisions are itemized and rationalized as much as is reasonable. The examples presented in this publication are provided as starting points which can be used as a design

  15. Embedded DAQ System Design for Temperature and Humidity Measurement

    Directory of Open Access Journals (Sweden)

    Tarique Rafique Memon

    2016-05-01

    Full Text Available In this work, we have proposed a cost effective DAQ (Data Acquisition system design useful for local industries by using user friendly LABVIEW (Laboratory Virtual Instrumentation Electronic Workbench. The proposed system can measure and control different industrial parameters which can be presented in graphical icon format. The system design is proposed for 8-channels, whereas tested and recorded for two parameters i.e. temperature and RH (Relative Humidity. Both parameters are set as per upper and lower limits and controlled using relays. Embedded system is developed using standard microcontroller to acquire and process the analog data and plug-in for further processing using serial interface with PC using LABVIEW. The designed system is capable of monitoring and recording the corresponding linkage between temperature and humidity in industrial unit's and indicates the abnormalities within the process and control those abnormalities through relays

  16. System design description for surface moisture measurement system (SMMS)

    Energy Technology Data Exchange (ETDEWEB)

    Vargo, G.F.

    1996-09-23

    The SMMS has been developed to measure moisture in the top few centimeters of tank waste. The SMMS development was initiated by the preliminary findings of SAR-033, and does not necessarily fulfill any established DQO. After the SAR-033 is released, if no significant changes are made, moisture measurements in the organic waste tanks will rapidly become a DQO. The SMMS was designed to be installed in any 4 inch or larger riser, and to allow maximum adjustability for riser lengths, and is used to deploy a sensor package on the waste surface within a 6 foot radius about the azimuth. The first sensor package will be a neutron probe.

  17. 躯体X线测量板的研制和应用%Validation and repeatability of Limb X Film Measuring Plate

    Institute of Scientific and Technical Information of China (English)

    卫小春; 柴旭峰; 许趁心

    2008-01-01

    Objective To study the efficacy and repeatability of the Limb X Film Measuring Plate (LXMP)in clinical x film measurement of lengths and angles of limbs.Methods The LXMP was de- signed and manufactured for testing.Three known points in 9 templates were taken as golden standards.which were to be compared with measuring results of these projected points on the X film for testing efficacy of LXMP.Twenty-one patients with knees osteoarthritis were selected.The lengths and angles of their lower limbs were measured twice with the help of LXMP by an observer at different time intervals for testing in. Tra-observer repeatability.Two observers measured once on films at the same time for testing inter-observer repeatability.The correlation coefficients,mean absolute difierences between the repeated measurements,and error rate were calculated. Results The points on LXMP could be seen clearly on X film.Validation tests showed the differences in angle measurement between golden standards and measuring results for those pro- jeted points on the X film were insignificant.with mean absolute difference being O.10.-0.21,error rate being 0.12%-3.15%and r being close to 1.The differences in length measurement were insignificant ei- ther,with mean absolute differenee being 0.05 cm-0.16 cm.error rate being 0.12%-o.28%and r being close to 1.The intra-observer repeatability test for beth angles and lengths showed that r was close to I.mean absolute diffefences 0.55.and 0.1-0.37cm and error rate 0.3l%-O.97%.while the inter-observer re- peatability test showed that r was close to 1.mean absolute difierences o.39.and0.05-0.13cm and error rate O.16%-O.35%. Conclusion The Limb X Film Measuring Plate Can be used for accurately mcasuring limb lengths and angles with good efficacy and repeatability.%目的 介绍躯体X线测量板的制作方法 ,探讨其有效性、重复性,为临床X线测量提供一套精确、实用、经济的方法 和工具.方法 设计和制作躯体X线

  18. Changes in surgical team performance and safety climate attitudes following expansion of perioperative services: a repeated-measures study.

    Science.gov (United States)

    Gillespie, Brigid M; Harbeck, Emma; Kang, Evelyn; Steel, Catherine; Fairweather, Nicole; Chaboyer, Wendy

    2017-08-10

    Objective The aim of the present study was to describe process changes in surgical team performance and team members' attitudes to safety culture following hospital relocation and expansion of perioperative services.Methods The study was a naturalistic study using structured observations and surveys to assess non-technical skills (NTS; i.e. communication, teamwork, situational awareness, decision making and leadership) in surgery. This interrupted time series design used mixed-linear regression models to examine the effect of phase (before and after hospital relocation) on surgical teams' NTS and their processes that may affect performance. Differences in self-reported teamwork and safety climate attitudes were also examined.Results In all, 186 procedures (100 before and 81 after hospital relocation) were observed across teams working in general, paediatric, orthopaedic and thoracic surgeries. Interobserver agreement ranged from 86% to 95%. An effect of phase was found, indicating that there were significant improvements after relocation in the use of NTS by the teams observed (P=0.020; 95% confidence interval 1.9-4.7).Conclusions The improvements seen in surgical teams' NTS performance and safety culture attitudes may be related to the move to a new state-of-the-art perioperative department.What is known about the topic? Patient safety in surgery relies on optimal team performance, underpinned by effective NTS.What does this paper add? The NTS of surgical teams may be improved through ergonomic innovations that promote teams' shared mental models.What are the implications for practitioners? Effective multidisciplinary teamwork relies on a combination of NTS and ergonomic factors, which inherently contribute to team performance and safety climate attitudes.

  19. Proceedings of Pulsed Magnet Design and Measurement Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Shaftan, T.; Heese, R.; Ozaki,S.

    2010-01-19

    The goals of the Workshop are to assess the design of pulsed system at the NSLS-II and establish mitigation strategies for critical issues during development. The focus of the Workshop is on resolving questions related to the set-up of the pulsed magnet laboratory, on measuring the pulsed magnet's current waveforms and fields, and on achieving tight tolerances on the magnet's alignment and field quality.

  20. New Discrete Fibonacci Charge Pump Design, Evaluation and Measurement

    Directory of Open Access Journals (Sweden)

    Matoušek David

    2017-06-01

    Full Text Available This paper focuses on the practical aspects of the realisation of Dickson and Fibonacci charge pumps. Standard Dickson charge pump circuit solution and new Fibonacci charge pump implementation are compared. Both charge pumps were designed and then evaluated by LTspice XVII simulations and realised in a discrete form on printed circuit board (PCB. Finally, the key parameters as the output voltage, efficiency, rise time, variable power supply and clock frequency effects were measured.

  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. Evaluation of Multiple Imputation in Missing Data Analysis: An Application on Repeated Measurement Data in Animal Science

    Directory of Open Access Journals (Sweden)

    Gazel Ser

    2015-12-01

    Full Text Available The purpose of this study was to evaluate the performance of multiple imputation method in case that missing observation structure is at random and completely at random from the approach of general linear mixed model. The application data of study was consisted of a total 77 heads of Norduz ram lambs at 7 months of age. After slaughtering, pH values measured at five different time points were determined as dependent variable. In addition, hot carcass weight, muscle glycogen level and fasting durations were included as independent variables in the model. In the dependent variable without missing observation, two missing observation structures including Missing Completely at Random (MCAR and Missing at Random (MAR were created by deleting the observations at certain rations (10% and 25%. After that, in data sets that have missing observation structure, complete data sets were obtained using MI (multiple imputation. The results obtained by applying general linear mixed model to the data sets that were completed using MI method were compared to the results regarding complete data. In the mixed model which was applied to the complete data and MI data sets, results whose covariance structures were the same and parameter estimations and standard estimations were rather close to the complete data are obtained. As a result, in this study, it was ensured that reliable information was obtained in mixed model in case of choosing MI as imputation method in missing observation structure and rates of both cases.

  3. Bayesian hierarchical joint modeling of repeatedly measured continuous and ordinal markers of disease severity: Application to Ugandan diabetes data.

    Science.gov (United States)

    Buhule, O D; Wahed, A S; Youk, A O

    2017-08-22

    Modeling of correlated biomarkers jointly has been shown to improve the efficiency of parameter estimates, leading to better clinical decisions. In this paper, we employ a joint modeling approach to a unique diabetes dataset, where blood glucose (continuous) and urine glucose (ordinal) measures of disease severity for diabetes are known to be correlated. The postulated joint model assumes that the outcomes are from distributions that are in the exponential family and hence modeled as multivariate generalized linear mixed effects model associated through correlated and/or shared random effects. The Markov chain Monte Carlo Bayesian approach is used to approximate posterior distribution and draw inference on the parameters. This proposed methodology provides a flexible framework to account for the hierarchical structure of the highly unbalanced data as well as the association between the 2 outcomes. The results indicate improved efficiency of parameter estimates when blood glucose and urine glucose are modeled jointly. Moreover, the simulation studies show that estimates obtained from the joint model are consistently less biased and more efficient than those in the separate models. Copyright © 2017 John Wiley & Sons, Ltd.

  4. 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.

  5. The Effects of Repeat Testing, Malingering, and Traumatic Brain Injury on Computerized Measures of Visuospatial Memory Span.

    Science.gov (United States)

    Woods, David L; Wyma, John M; Herron, Timothy J; Yund, E W

    2015-01-01

    Spatial span tests (SSTs) such as the Corsi Block Test (CBT) and the SST of the Wechsler Memory Scale are widely used to assess deficits in spatial working memory. We conducted three experiments to evaluate the test-retest reliability and clinical sensitivity of a new computerized spatial span test (C-SST) that incorporates psychophysical methods to improve the precision of spatial span measurement. In Experiment 1, we analyzed C-SST test-retest reliability in 49 participants who underwent three test sessions at weekly intervals. Intraclass correlation coefficients (ICC) were higher for a psychophysically derived mean span (MnS) metric (0.83) than for the maximal span and total correct metrics used in traditional spatial-span tests. Response times (ReTs) also showed high ICCs (0.93) that correlated negatively with MnS scores and correlated positively with response-time latencies from other tests of processing speed. Learning effects were insignificant. Experiment 2 examined the performance of Experiment 1 participants when instructed to feign symptoms of traumatic brain injury (TBI): 57% showed abnormal MnS z-scores. A MnS z-score cutoff of 3.0 correctly classified 36% of simulated malingerers and 91% of the subgroup of 11 control participants with abnormal spans. Malingerers also made more substitution errors than control participants with abnormal spans (sensitivity = 43%, specificity = 91%). In addition, malingerers showed no evidence of ReT slowing, in contrast to significant abnormalities seen on other malingered tests of processing speed. As a result, differences between ReT z-scores and z-scores on other processing speed tests showed very high sensitivity and specificity in distinguishing malingering and control participants with either normal or abnormal spans. Experiment 3 examined C-SST performance in a group of patients with predominantly mild TBI: neither MnS nor ReT z-scores showed significant group-level abnormalities. The C-SST improves the

  6. A statistical approach designed for finding mathematically defined repeats in shotgun data and determining the length distribution of clone-inserts

    DEFF Research Database (Denmark)

    Zhong, Lan; Zhang, Kunlin; Huang, Xiangang

    2003-01-01

    The large amount of repeats, especially high copy repeats, in the genomes of higher animals and plants makes whole genome assembly (WGA) quite difficult. In order to solve this problem, we tried to identify repeats and mask them prior to assembly even at the stage of genome survey. It is known...... that repeats of different copy number have different probabilities of appearance in shotgun data, so based on this principle, we constructed a statistical model and inferred criteria for mathematically defined repeats (MDRs) at different shotgun coverages. According to these criteria, we developed software......-inserts using our model. In our simulated genomes of human and rice, the length distribution of repeats is different, so their optimal length distributions of clone-inserts were not the same. Thus with optimal length distribution of clone-inserts, a given genome could be assembled better at lower coverage...

  7. 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

    2017-09-04

    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.

  8. IMAGE SELECTION FOR 3D MEASUREMENT BASED ON NETWORK DESIGN

    Directory of Open Access Journals (Sweden)

    T. Fuse

    2015-05-01

    Full Text Available 3D models have been widely used by spread of many available free-software. On the other hand, enormous images can be easily acquired, and images are utilized for creating the 3D models recently. However, the creation of 3D models by using huge amount of images takes a lot of time and effort, and then efficiency for 3D measurement are required. In the efficiency strategy, the accuracy of the measurement is also required. This paper develops an image selection method based on network design that means surveying network construction. The proposed method uses image connectivity graph. By this, the image selection problem is regarded as combinatorial optimization problem and the graph cuts technique can be applied. Additionally, in the process of 3D reconstruction, low quality images and similarity images are extracted and removed. Through the experiments, the significance of the proposed method is confirmed. Potential to efficient and accurate 3D measurement is implied.

  9. Directionality switchable gain stabilized linear repeater

    Science.gov (United States)

    Ota, Takayuki; Ohmachi, Tadashi; Aida, Kazuo

    2004-10-01

    We propose a new approach to realize a bidirectional linear repeater suitable for future optical internet networks and fault location in repeater chain with OTDR. The proposed approach is the linear repeater of simple configuration whose directionality is rearranged dynamically by electrical control signal. The repeater is composed of a magneto-optical switch, a circulator, a dynamically gain stabilized unidirectional EDFA, and control circuits. The repeater directionality is rearranged as fast as 0.1ms by an electrical control pulse. It is experimentally confirmed that OTDR with the directionality switchable repeater is feasible for repeater chain. The detailed design and performance of the repeater are also discussed, including the multi-pass interference (MPI) which may arise in the proposed repeater, the effect of the MPI on SNR degradation of the repeater chain and the feed-forward EDFA gain control circuit.

  10. Improving measurement technology for the design of sustainable cities

    Science.gov (United States)

    Pardyjak, Eric R.; Stoll, Rob

    2017-09-01

    This review identifies and discusses measurement technology gaps that are currently preventing major science leaps from being realized in the study of urban environmental transport processes. These scientific advances are necessary to better understand the links between atmospheric transport processes in the urban environment, human activities, and potential management strategies. We propose that with various improved and targeted measurements, it will be possible to provide technically sound guidance to policy and decision makers for the design of sustainable cities. This review focuses on full-scale in situ and remotely sensed measurements of atmospheric winds, temperature, and humidity in cities and links measurements to current modeling and simulation needs. A key conclusion of this review is that there is a need for urban-specific measurement techniques including measurements of highly-resolved three-dimensional fields at sampling frequencies high enough to capture small-scale turbulence processes yet also capable of covering spatial extents large enough to simultaneously capture key features of urban heterogeneity and boundary layer processes while also supporting the validation of current and emerging modeling capabilities.

  11. The design and application of large area intensive lens array focal spots measurement system

    Science.gov (United States)

    Chen, Bingzhen; Yao, Shun; Yang, Guanghui; Dai, Mingchong; Wang, Zhiyong

    2014-12-01

    Concentrating Photovoltaic (CPV) modules are getting thinner and using smaller cells now days. Correspondingly, large area intensive lens arrays with smaller unit dimension and shorter focal length are wanted. However, the size and power center of lens array focal spots usually differ from the design value and are hard to measure, especially under large area situation. It is because the machining error and deformation of material of the lens array are hard to simulate in the optical design process. Thus the alignment error between solar cells and focal spots in the module assembly process will be hard to control. Under this kind of situation, the efficiency of CPV module with thinner body and smaller cells is much lower than expected. In this paper, a design of large area lens array focal spots automatic measurement system is presented, as well as its prototype application results. In this system, a four-channel parallel light path and its corresponding image capture and process modules are designed. These modules can simulate focal spots under sunlight and have the spots image captured and processed using charge coupled devices and certain gray level algorithm. Thus the important information of focal spots such as spot size and location will be exported. Motion control module based on grating scale signal and interval measurement method are also employed in this system in order to get test results with high speed and high precision on large area lens array no less than 1m×0.8m. The repeatability of the system prototype measurement is +/-10μm with a velocity of 90 spot/min. Compared to the original module assembled using coordinates from optical design, modules assembled using data exported from the prototype is 18% higher in output power, reaching a conversion efficiency of over 31%. This system and its design can be used in the focal spot measurement of planoconvex lens array and Fresnel lens array, as well as other kinds of large area lens array application

  12. Robust Design of Reliability Test Plans Using Degradation Measures.

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Jonathan Wesley; Lane, Jonathan Wesley; Crowder, Stephen V.; Crowder, Stephen V.

    2014-10-01

    With short production development times, there is an increased need to demonstrate product reliability relatively quickly with minimal testing. In such cases there may be few if any observed failures. Thus, it may be difficult to assess reliability using the traditional reliability test plans that measure only time (or cycles) to failure. For many components, degradation measures will contain important information about performance and reliability. These measures can be used to design a minimal test plan, in terms of number of units placed on test and duration of the test, necessary to demonstrate a reliability goal. Generally, the assumption is made that the error associated with a degradation measure follows a known distribution, usually normal, although in practice cases may arise where that assumption is not valid. In this paper, we examine such degradation measures, both simulated and real, and present non-parametric methods to demonstrate reliability and to develop reliability test plans for the future production of components with this form of degradation.

  13. Measurement of Spray Drift with a Specifically Designed Lidar System.

    Science.gov (United States)

    Gregorio, Eduard; Torrent, Xavier; Planas de Martí, Santiago; Solanelles, Francesc; Sanz, Ricardo; Rocadenbosch, Francesc; Masip, Joan; Ribes-Dasi, Manel; Rosell-Polo, Joan R

    2016-04-08

    Field measurements of spray drift are usually carried out by passive collectors and tracers. However, these methods are labour- and time-intensive and only provide point- and time-integrated measurements. Unlike these methods, the light detection and ranging (lidar) technique allows real-time measurements, obtaining information with temporal and spatial resolution. Recently, the authors have developed the first eye-safe lidar system specifically designed for spray drift monitoring. This prototype is based on a 1534 nm erbium-doped glass laser and an 80 mm diameter telescope, has scanning capability, and is easily transportable. This paper presents the results of the first experimental campaign carried out with this instrument. High coefficients of determination (R² > 0.85) were observed by comparing lidar measurements of the spray drift with those obtained by horizontal collectors. Furthermore, the lidar system allowed an assessment of the drift reduction potential (DRP) when comparing low-drift nozzles with standard ones, resulting in a DRP of 57% (preliminary result) for the tested nozzles. The lidar system was also used for monitoring the evolution of the spray flux over the canopy and to generate 2-D images of these plumes. The developed instrument is an advantageous alternative to passive collectors and opens the possibility of new methods for field measurement of spray drift.

  14. Measurement Matrix Design for Compressive Sensing Based MIMO Radar

    CERN Document Server

    Yu, Y; Poor, H V

    2011-01-01

    In colocated multiple-input multiple-output (MIMO) radar using compressive sensing (CS), a receive node compresses its received signal via a linear transformation, referred to as measurement matrix. The samples are subsequently forwarded to a fusion center, where an L1-optimization problem is formulated and solved for target information. CS-based MIMO radar exploits the target sparsity in the angle-Doppler-range space and thus achieves the high localization performance of traditional MIMO radar but with many fewer measurements. The measurement matrix is vital for CS recovery performance. This paper considers the design of measurement matrices that achieve an optimality criterion that depends on the coherence of the sensing matrix (CSM) and/or signal-to-interference ratio (SIR). The first approach minimizes a performance penalty that is a linear combination of CSM and the inverse SIR. The second one imposes a structure on the measurement matrix and determines the parameters involved so that the SIR is enhanced...

  15. Measurement of Surface Displacement and Deformation of Mass Movements Using Least Squares Matching of Repeat High Resolution Satellite and Aerial Images

    Directory of Open Access Journals (Sweden)

    Misganu Debella-Gilo

    2012-01-01

    Full Text Available Displacement and deformation are fundamental measures of Earth surface mass movements such as glacier flow, rockglacier creep and rockslides. Ground-based methods of monitoring such mass movements can be costly, time consuming and limited in spatial and temporal coverage. Remote sensing techniques, here matching of repeat optical images, are increasingly used to obtain displacement and deformation fields. Strain rates are usually computed in a post-processing step based on the gradients of the measured velocity field. This study explores the potential of automatically and directly computing velocity, rotation and strain rates on Earth surface mass movements simultaneously from the matching positions and the parameters of the geometric transformation models using the least squares matching (LSM approach. The procedures are exemplified using bi-temporal high resolution satellite and aerial images of glacier flow, rockglacier creep and land sliding. The results show that LSM matches the images and computes longitudinal strain rates, transverse strain rates and shear strain rates reliably with mean absolute deviations in the order of 10−4 (one level of significance below the measured values as evaluated on stable grounds. The LSM also improves the accuracy of displacement estimation of the pixel-precision normalized cross-correlation by over 90% under ideal (simulated circumstances and by about 25% for real multi-temporal images of mass movements.

  16. Lumbar spine and pelvic posture between standing and sitting: a radiologic investigation including reliability and repeatability of the lumbar lordosis measure.

    Science.gov (United States)

    De Carvalho, Diana E; Soave, David; Ross, Kim; Callaghan, Jack P

    2010-01-01

    Sitting has been identified as a cause of mechanical low back pain. The purpose of this study was to use plain film x-rays to measure lumbar spine and pelvic posture differences between standing and sitting. Eight male subjects were radiographed standing and sitting in an automobile seat. Measures of lumbar lordosis, intervertebral disk angles, lumbosacral angle, lumbosacral lordosis, and sacral tilt were completed. One-way analysis of variance (alpha = .05) was conducted on the variables stated above. A Bland-Altman analysis was conducted to assess agreement and repeatability of the lumbar lordosis angle using 2 raters. Lumbar lordosis values in standing (average, 63 degrees +/- 15 degrees ) and sacral inclination (average, 43 degrees +/- 10 degrees ) decreased by 43 degrees and 44 degrees , respectively, in sitting. Intervertebral joint angles in sitting underwent substantial flexion (L1/L2-5 degrees [+/-3 degrees ], L2/L3-7 degrees [+/-3 degrees ], L3/L4-8 degrees [+/-3 degrees ], L4/L5-13 degrees [+/-3 degrees ], and L5/S1-4 degrees [+/-10 degrees ]). Measures of lumbar lordosis; intervertebral disk angles between L2/L3, L3/L4, and L4/L5; lumbosacral lordosis; lumbosacral angle; and sacral tilt were significantly decreased between standing and sitting (P posture should be investigated because they may play a role in preventing injury and low back pain. Copyright 2010 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

  17. Additional notes on clinical repeated-dose pharmacokinetic trials applying a peak-and-trough sampling design to estimate oral clearance.

    Science.gov (United States)

    Takaai, Mari; Kayano, Yuichiro; Shimizu, Takako; Taguchi, Masato; Hashimoto, Yukiya

    2008-01-01

    In the previous study, we performed a simulation of a clinical pharmacokinetic trial, in which blood was sampled at two time points corresponding to the peak concentration (C(peak)) and trough concentration (C(trough)) following repetitive oral administration at the dose, D, and dosing interval, tau. The approximate oral clearance (CL/F(approx)), estimated as 2 x D/(C(peak) x tau+C(trough) x tau), is accurate for drugs with an elimination half-life comparative to or longer than tau; however, it was suggested that we might not use CL/F(approx) for drugs with a considerably short elimination half-life relative to tau. In the present study, we evaluated the accuracy of the alternative oral clearance (CL/F(exp)) estimated by the simple monoexponential model. In contrast to CL/F(approx), CL/F(exp) was accurate for drugs with a short elimination half-life relative to tau. The present finding in conjunction with our previous study suggested that the peak-and-trough sampling design is promising for the clinical repeated-dose pharmacokinetic trial for drugs with not only slow but also rapid elimination from the body. We think that the accuracy and precision of the two analysis methods to estimate oral clearance (CL/F(approx) and CL/F(exp)) for a target drug should be evaluated carefully before and after a real clinical trial.

  18. 基于同频RF直放站的回波测量方法%Technique of measuring the echo for RF repeaters in single frequency networks

    Institute of Scientific and Technical Information of China (English)

    陈哲; 宋葛

    2011-01-01

    直放站的同频转发模式存在收发天线间互耦的问题,接收天线在接收主基站的信号时,同时接收到直放站发射天线发射的信号,以同频RF直放站调试隔离度为技术背景,提出了同频RF直放站的回波测量方法.该方法利用CAZAC码实现的初估计快速地估计出回波信道的特性,自适应LMS算法的使用可以进一步跟踪信道的变化.通过MATLAB仿真后,在数字硬件平台上用FPGA实现该方法,并用数字电视信号CMMB做为信号源对系统进行了测试,结果说明此种测量方法准确、实用.%The signal transition mode of repeater which works on the same frequency has some troubles on signal coupling between receive and transmit aerials,the signal from transmit aerial may leak out into receive aerial. This paper presents a method of measuring the echo under the context of isolation test for RF repeaters in single frequency networks. The experimental apparatus firstly uses CAZAC code as the method of channel initial estimation, secondly uses LMS arithmetic to track the change of the channel. After the MATLAB simulation realization has been achieved by FPGA on real digital hardware board. The result of test which uses DTV signal (CMMB) as the source proves the function of method achieved accurately.

  19. 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

  20. Magnetic Barkhausen Noise Measurements Using Tetrapole Probe Designs

    Science.gov (United States)

    McNairnay, Paul

    A magnetic Barkhausen noise (MBN) testing system was developed for Defence Research and Development Canada (DRDC) to perform MBN measurements on the Royal Canadian Navy's Victoria class submarine hulls that can be correlated with material properties, including residual stress. The DRDC system was based on the design of a MBN system developed by Steven White at Queen's University, which was capable of performing rapid angular dependent measurements through the implementation of a flux controlled tetrapole probe. In tetrapole probe designs, the magnetic excitation field is rotated in the surface plane of the sample under the assumption of linear superposition of two orthogonal magnetic fields. During the course of this work, however, the validity of flux superposition in ferromagnetic materials, for the purpose of measuring MBN, was brought into question. Consequently, a study of MBN anisotropy using tetrapole probes was performed. Results indicate that MBN anisotropy measured under flux superposition does not simulate MBN anisotropy data obtained through manual rotation of a single dipole excitation field. It is inferred that MBN anisotropy data obtained with tetrapole probes is the result of the magnetic domain structure's response to an orthogonal magnetization condition and not necessarily to any bulk superposition magnetization in the sample. A qualitative model for the domain configuration under two orthogonal magnetic fields is proposed to describe the results. An empirically derived fitting equation, that describes tetrapole MBN anisotropy data, is presented. The equation describes results in terms of two largely independent orthogonal fields, and includes interaction terms arising due to competing orthogonally magnetized domain structures and interactions with the sample's magnetic easy axis. The equation is used to fit results obtained from a number of samples and tetrapole orientations and in each case correctly identifies the samples' magnetic easy axis.

  1. Design of psychosocial factors questionnaires: a systematic measurement approach

    Science.gov (United States)

    Vargas, Angélica; Felknor, Sarah A

    2012-01-01

    Background Evaluation of psychosocial factors requires instruments that measure dynamic complexities. This study explains the design of a set of questionnaires to evaluate work and non-work psychosocial risk factors for stress-related illnesses. Methods The measurement model was based on a review of literature. Content validity was performed by experts and cognitive interviews. Pilot testing was carried out with a convenience sample of 132 workers. Cronbach’s alpha evaluated internal consistency and concurrent validity was estimated by Spearman correlation coefficients. Results Three questionnaires were constructed to evaluate exposure to work and non-work risk factors. Content validity improved the questionnaires coherence with the measurement model. Internal consistency was adequate (α=0.85–0.95). Concurrent validity resulted in moderate correlations of psychosocial factors with stress symptoms. Conclusions Questionnaires´ content reflected a wide spectrum of psychosocial factors sources. Cognitive interviews improved understanding of questions and dimensions. The structure of the measurement model was confirmed. PMID:22628068

  2. Design of a Device for Sky Light Polarization Measurements

    Directory of Open Access Journals (Sweden)

    Yujie Wang

    2014-08-01

    Full Text Available ky polarization patterns can be used both as indicators of atmospheric turbidity and as a sun compass for navigation. The objective of this study is to improve the precision of sky light polarization measurements by optimal design of the device used. The central part of the system is composed of a Charge Coupled Device (CCD camera; a fish-eye lens and a linear polarizer. Algorithms for estimating parameters of the polarized light based on three images are derived and the optimal alignments of the polarizer are analyzed. The least-squares estimation is introduced for sky light polarization pattern measurement. The polarization patterns of sky light are obtained using the designed system and they follow almost the same patterns of the single-scattering Rayleigh model. Deviations of polarization angles between observation and the theory are analyzed. The largest deviations occur near the sun and anti-sun directions. Ninety percent of the deviations are less than 5° and 40% percent of them are less than 1°. The deviations decrease evidently as the degree of polarization increases. It also shows that the polarization pattern of the cloudy sky is almost identical as in the blue sky.

  3. Performance Measurement of a Multi-Level/Analog Ferroelectric Memory Device Design

    Science.gov (United States)

    MacLeod, Todd C.; Phillips, Thomas A.; Ho, Fat D.

    2007-01-01

    Increasing the memory density and utilizing the unique characteristics of ferroelectric devices is important in making ferroelectric memory devices more desirable to the consumer. This paper describes the characterization of a design that allows multiple levels to be stored in a ferroelectric based memory cell. It can be used to store multiple bits or analog values in a high speed nonvolatile memory. The design utilizes the hysteresis characteristic of ferroelectric transistors to store an analog value in the memory cell. The design also compensates for the decay of the polarization of the ferroelectric material over time. This is done by utilizing a pair of ferroelectric transistors to store the data. One transistor is used a reference to determinethe amount of decay that has occurred since the pair was programmed. The second transistor stores the analog value as a polarization value between zero and saturated. The design allows digital data to be stored as multiple bits in each memory cell. The number of bits per cell that can be stored will vary with the decay rate of the ferroelectric transistors and the repeatability of polarization between transistors. This paper presents measurements of an actual prototype memory cell. This prototype is not a complete implementation of a device, but instead, a prototype of the storage and retrieval portion of an actual device. The performance of this prototype is presented with the projected performance of the overall device. This memory design will be useful because it allows higher memory density, compensates for the environmental and ferroelectric aging processes, allows analog values to be directly stored in memory, compensates for the thermal and radiation environments associated with space operations, and relies only on existing technologies.

  4. Design and theoretical analysis of a resonant sensor for liquid density measurement.

    Science.gov (United States)

    Zheng, Dezhi; Shi, Jiying; Fan, Shangchun

    2012-01-01

    In order to increase the accuracy of on-line liquid density measurements, a sensor equipped with a tuning fork as the resonant sensitive component is designed in this paper. It is a quasi-digital sensor with simple structure and high precision. The sensor is based on resonance theory and composed of a sensitive unit and a closed-loop control unit, where the sensitive unit consists of the actuator, the resonant tuning fork and the detector and the closed-loop control unit comprises precondition circuit, digital signal processing and control unit, analog-to-digital converter and digital-to-analog converter. An approximate parameters model of the tuning fork is established and the impact of liquid density, position of the tuning fork, temperature and structural parameters on the natural frequency of the tuning fork are also analyzed. On this basis, a tuning fork liquid density measurement sensor is developed. In addition, experimental testing on the sensor has been carried out on standard calibration facilities under constant 20 °C, and the sensor coefficients are calibrated. The experimental results show that the repeatability error is about 0.03% and the accuracy is about 0.4 kg/m(3). The results also confirm that the method to increase the accuracy of liquid density measurement is feasible.

  5. An integrated approach to biomonitoring exposure to styrene and styrene-(7,8)-oxide using a repeated measurements sampling design.

    Science.gov (United States)

    Fustinoni, S; Campo, L; Manini, P; Buratti, M; Waidyanatha, S; De Palma, G; Mutti, A; Foa, V; Colombi, A; Rappaport, S M

    2008-09-01

    The aim of this work was to investigate urinary analytes and haemoglobin and albumin adducts as biomarkers of exposure to airborne styrene (Sty) and styrene-(7,8)-oxide (StyOX) and to evaluate the influence of smoking habit and genetic polymorphism of metabolic enzymes GSTM1 and GSTT1 on these biomarkers. We obtained three or four air and urine samples from each exposed worker (eight reinforced plastics workers and 13 varnish workers), one air and urine samples from 22 control workers (automobile mechanics) and one blood sample from all subjects. Median levels of exposure to Sty and StyOX, respectively, were 18.2 mg m(-3) and 133 microg m(-3) for reinforced plastics workers, 3.4 mg m(-3) and 12 microg m(-3) for varnish workers, and <0.3 mg m(-3) and <5 microg m(-3) for controls. Urinary levels of styrene, mandelic acid, phenylglyoxylic acid, phenylglycine (PHG), 4-vinylphenol (VP) and mercapturic acids (M1+M2), as well as cysteinyl adducts of serum albumin (but not those of haemoglobin) were significantly associated with exposure status (controls

  6. 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

  7. Structure design and mechanical measurement of inflatable antenna

    Science.gov (United States)

    Xu, Yan; Guan, Fu-ling

    2012-07-01

    This paper deals with the initial shape analysis, cutting-pattern analysis, surface accuracy measurement and modal testing of high-precision inflatable antennas reflectors that are intended for spaceflight applications. The initial shape analysis method, formulated on the basis of membrane theory and elastic mechanics, determines the required as-manufactured shape of the reflective surface of the antenna reflector. On the other hand, the cutting-pattern analysis method, with its formulation based on spring-mass representations, numerically calculates the required cutting pattern of the planar membrane gores that are to be assembled to form the 3-dimensional reflective surface. To validate the effectiveness of the proposed analysis methods, a 3.2-m antenna reflector model was designed, manufactured, and assembled for ground demonstration and testing. The reflective surface accuracy of this demonstration reflector model was measured by a photogrammetric measuring system. Shape adjustments of the reflective surface were performed by systematically adjusting the tension in the cables that were used to mount the reflector to its support structure. It was found that the reflective surface accuracy of the reflector model, as defined by its RMS error from a best-fit parabolic shape, was less than 1 mm. In addition, dynamic and RF tests were also performed on the demonstration reflector model. The test results indicated that the first-mode frequency of the reflector model agreed well with the corresponding analytical prediction, and its radiation pattern was also well focused.

  8. The Design of a Calorimeter to Measure Concentrated Solar Flux

    Science.gov (United States)

    Sefkow, Elizabeth Anne Bennett

    A water-cooled, cavity calorimeter was designed to accurately measure concentrated solar thermal power produced by the University of Minnesota's solar simulator. The cavity is comprised of copper tubing bent into spiral and helical coils for the base and cylindrical walls, respectively. Insulation surrounds the cavity to reduce heat transfer to the ambient, and a water- cooled aperture cover is positioned at the open end of the cavity. The calorimeter measures the heat gain of water flowing through the system as radiant energy is passed through the aperture. Chilled water flows through the tubing, and the energy incident on the cavity surface is conducted through the wall and convected to the flowing water. The energy increase in the water can be observed by an increase in fluid temperature. A Monte Carlo ray tracing method is used to predict the incident flux distribution and corresponding power on the surfaces of the cavity. These values are used to estimate the thermal losses of the system, and it is found that they account for less that 1% of the total power passed through the aperture. The overall uncertainty of the calorimeter is found by summing the measured uncertainty and the estimated heat loss and is found to be +/-2.5% for 9.2 kW of power output and +/-3.4% for 3 kW.

  9. Orthogonal assembly of a designed ankyrin repeat protein-cytotoxin conjugate with a clickable serum albumin module for half-life extension.

    Science.gov (United States)

    Simon, Manuel; Frey, Raphael; Zangemeister-Wittke, Uwe; Plückthun, Andreas

    2013-11-20

    The generation of drug conjugates for safe and effective tumor targeting requires binding proteins tolerant to functionalization by rational engineering. Here, we show that Designed Ankyrin Repeat Proteins (DARPins), a novel class of binding proteins not derived from antibodies, can be used as building blocks for facile orthogonal assembly of bioconjugates for tumor targeting with tailored properties. DARPin Ec1, which targets the Epithelial Cell Adhesion Molecule (EpCAM), was genetically modified with a C-terminal cysteine for conjugation of the small molecule cytotoxin monomethylauristatin F (MMAF). In addition, it was N-terminally functionalized by metabolic introduction of the non-natural amino acid azidohomoalanine to enable linkage of site-specifically dibenzocyclooctyne-modified mouse serum albumin (MSA) for half-life extension using Cu(I)-free click chemistry. The conjugate MSA-Ec1-MMAF was assembled to obtain high yields of a pure and stable drug conjugate as confirmed by various analytical methods and in functional assays. The orthogonality of the assembly led to a defined reaction product and preserved the functional properties of all modules, including EpCAM-specific binding and internalization, FcRn binding mediated by MSA, and cytotoxic potency. Linkage of MMAF to the DARPin increased receptor-specific uptake of the drug while decreasing nonspecific uptake, and further coupling of the conjugate to MSA enhanced this effect. In mice, albumin conjugation increased the serum half-life from 11 min to 17.4 h, resulting in a more than 22-fold increase in the area-under-the-curve (AUC). Our data demonstrate the promise of the DARPin format for facile modular assembly of drug conjugates with improved pharmacokinetic performance for tumor targeting.

  10. ProtRepeatsDB: a database of amino acid repeats in genomes

    Directory of Open Access Journals (Sweden)

    Chauhan Virander S

    2006-07-01

    Full Text Available Abstract Background Genome wide and cross species comparisons of amino acid repeats is an intriguing problem in biology mainly due to the highly polymorphic nature and diverse functions of amino acid repeats. Innate protein repeats constitute vital functional and structural regions in proteins. Repeats are of great consequence in evolution of proteins, as evident from analysis of repeats in different organisms. In the post genomic era, availability of protein sequences encoded in different genomes provides a unique opportunity to perform large scale comparative studies of amino acid repeats. ProtRepeatsDB http://bioinfo.icgeb.res.in/repeats/ is a relational database of perfect and mismatch repeats, access to which is designed as a resource and collection of tools for detection and cross species comparisons of different types of amino acid repeats. Description ProtRepeatsDB (v1.2 consists of perfect as well as mismatch amino acid repeats in the protein sequences of 141 organisms, the genomes of which are now available. The web interface of ProtRepeatsDB consists of different tools to perform repeat s; based on protein IDs, organism name, repeat sequences, and keywords as in FASTA headers, size, frequency, gene ontology (GO annotation IDs and regular expressions (REGEXP describing repeats. These tools also allow formulation of a variety of simple, complex and logical queries to facilitate mining and large-scale cross-species comparisons of amino acid repeats. In addition to this, the database also contains sequence analysis tools to determine repeats in user input sequences. Conclusion ProtRepeatsDB is a multi-organism database of different types of amino acid repeats present in proteins. It integrates useful tools to perform genome wide queries for rapid screening and identification of amino acid repeats and facilitates comparative and evolutionary studies of the repeats. The database is useful for identification of species or organism specific

  11. Lithography beamline design and exposure uniformity controlling and measuring

    Science.gov (United States)

    Qian, Shinan; Jiang, Dikui; Liu, Zewen; Chen, Qianhong; Kan, Ya; Liu, Wanpo

    1989-07-01

    The lithography beamline design of Hefei National Synchrotron Radiation Laboratory is presented. A scanning mirror is used to cut off short wavelength radiation and to expand the vertical exposure dimension to 50 mm. A thin beryllium window is installed before the scanning mirror to prevent the longer wavelength radiation from going through. An exposure chamber with a vacuum of 5×10E-7 Torr is located at 7 m downstream from the source point. Because there is no window at the entrance of the chamber, a differential pumping system is used. The scanning mirror is driven by a stepping motor which oscillates through a 1° angle. The required driving speed curve is determined by a computer in order to obtain a uniform exposure area. An in situ moiré fringe grating system is used to measure the uniformity of the motor speed.

  12. Design, manufacture and measurements of permanent dipole magnets for DIRAC

    CERN Document Server

    Vorozhtsov, A; Kasaei, S; Solodko, E; Thonet, P A; Tommasini, D

    2013-01-01

    The one of the aim of the DIRAC experiment is the observation of the long-lived π+π- atoms, using the proton beam of the CERN Proton Synchrotron [1]. Two dipole magnets are needed for the for the DIRAC experiment as high resolution spectrometers. The dipole magnet will be used to identify the long-lived atoms on the high level background of π+π- pairs produced simultaneously with π+π- atoms. The proposed design is a permanent magnet dipole with a mechanical aperture of 60 mm. The magnet, of a total physical length of 66 mm, is based on Sm2Co17 blocks and provides an integrated field strength of 24·10-3 T×m. The Sm2Co17 was chosen as a material for the permanent magnet blocks due to its radiation hardness and weaker temperature dependence. The magnetic field quality is determined by 2 ferromagnetic poles, aligned together with the permanent magnets blocks. The paper describes the design, manufacture and magnetic measurements of the magnets.

  13. Evaluation of the running-based anaerobic sprint test as a measure of repeated sprint ability in collegiate-level soccer players.

    Science.gov (United States)

    Keir, Daniel A; Thériault, Francis; Serresse, Olivier

    2013-06-01

    Repeated sprint ability (RSA) refers to an individual's ability to perform maximal sprints of short duration in succession with little recovery between sprints. The running-based anaerobic sprint test (RAST) has been adapted from the Wingate anaerobic test (WAnT) protocol as a tool to assess RSA and anaerobic power. The purpose of this study was to evaluate the relationship between performance variables and physiological responses obtained during the RAST and the WAnT using 8 collegiate-level soccer players. Participants performed a single trial of both the WAnT and the RAST. Breath-by-breath gas exchange was monitored throughout each trial, and blood lactate (BL) measures were recorded postexercise. The oxygen uptake (VO2) profile suggested that the RAST required greater contributions from aerobic metabolism although there was no difference in VO2peak (p < 0.05). Peak BL values were also similar between the RAST and the WAnT (p < 0.05). Neither peak physiological values nor performance variables (peak and mean power) were significantly correlated between protocols. The weak association in physiological responses indicates that different combinations of metabolic contributions exist between protocols, suggesting that individual performances on each test are not related in collegiate soccer players. Further studies on these relationships with players of other competitive levels and team sport athletes are warranted.

  14. Knowledge and skill retention of in-service versus preservice nursing professionals following an informal training program in pediatric cardiopulmonary resuscitation: a repeated-measures quasiexperimental study.

    Science.gov (United States)

    Sankar, Jhuma; Vijayakanthi, Nandini; Sankar, M Jeeva; Dubey, Nandkishore

    2013-01-01

    Our objective was to compare the impact of a training program in pediatric cardiopulmonary resuscitation (CPR) on the knowledge and skills of in-service and preservice nurses at prespecified time points. This repeated-measures quasiexperimental study was conducted in the pediatric emergency and ICU of a tertiary care teaching hospital between January and March 2011. We assessed the baseline knowledge and skills of nursing staff (in-service nurses) and final year undergraduate nursing students (preservice nurses) using a validated questionnaire and a skill checklist, respectively. The participants were then trained on pediatric CPR using standard guidelines. The knowledge and skills were reassessed immediately after training and at 6 weeks after training. A total of 74 participants-28 in-service and 46 preservice professionals-were enrolled. At initial assessment, in-service nurses were found to have insignificant higher mean knowledge scores (6.6 versus 5.8, P = 0.08) while the preservice nurses had significantly higher skill scores (6.5 versus 3.2, P nurses performing better in knowledge test (10.5 versus 9.1, P = 0.01) and the preservice nurses performing better in skill test (9.8 versus 7.4, P skills of in-service and preservice nurses in pediatric CPR improved with training. In comparison to preservice nurses, the in-service nurses seemed to retain knowledge better with time than skills.

  15. Direct and accurate measurement of CAG repeat configuration in the ataxin-1 (ATXN-1) gene by "dual-fluorescence labeled PCR-restriction fragment length analysis".

    Science.gov (United States)

    Lin, Jiang X; Ishikawa, Kinya; Sakamoto, Masaki; Tsunemi, Taiji; Ishiguro, Taro; Amino, Takeshi; Toru, Shuta; Kondo, Ikuko; Mizusawa, Hidehiro

    2008-01-01

    Spinocerebellar ataxia type 1 (SCA1; OMIM: #164400) is an autosomal dominant cerebellar ataxia caused by an expansion of CAG repeat, which encodes polyglutamine, in the ataxin-1 (ATXN1) gene. Length of polyglutamine in the ATXN1 protein is the critical determinant of pathogenesis of this disease. Molecular diagnosis of SCA1 is usually undertaken by assessing the length of CAG repeat configuration using primers spanning this configuration. However, this conventional method may potentially lead to misdiagnosis in assessing polyglutamine-encoding CAG repeat length, since CAT interruptions may be present within the CAG repeat configuration, not only in normal controls but also in neurologically symptomatic subjects. We developed a new method for assessing actual CAG repeat numbers not interrupted by CAT sequences. Polymerase chain reaction using a primer pair labeled with two different fluorescences followed by restriction enzyme digestion with SfaNI which recognizes the sequence "GCATC(N)(5)", lengths of actual CAG repeats that encode polyglutamine were directly detected. We named this method "dual fluorescence labeled PCR-restriction fragment length analysis". We found that numbers of actual CAG repeat encoding polyglutamine do not overlap between our cohorts of normal chromosomes (n=385) and SCA1 chromosomes (n=5). We conclude that the present method is a useful way for molecular diagnosis of SCA1.

  16. Interim measure work plan/design for Agra, Kansas.

    Energy Technology Data Exchange (ETDEWEB)

    LaFreniere, L. M.; Environmental Science Division

    2008-11-18

    This Interim Measure Work Plan/Design (IMWP/D) is supplemental to the Argonne document Interim Measure Conceptual Design for Remediation of Source Area Contamination at Agra, Kansas. The IMWP/D includes information required by Kansas Department of Health and Environment (KDHE) Policy BER-RS-029, Policy and Scope of Work for Interim Measures. Specific to Policy BER-RS-029 is the requirement for several documents that will ensure that an adequate amount and type of data are collected for implementation of the IMWP/D and that data quality and safe conditions are prevailed. Such information is included in the IMWP/D as follows: Appendix A: Data Acquisition Plan--Design Testing Requirements; Appendix B: Basis of Design; Appendix C: Permits; Appendix D: Quality Assurance Project Plan; Appendix E: Health and Safety Plan; and Appendix F: Operations, Maintenance, and Monitoring Schedule. The proposed remedial technology for this project is the installation of five large-diameter boreholes (LDBs) in a source area that has been identified on the property formerly used for grain storage by the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA). The goal of the LDB technology is the remediation of the source area by removal of mass quantities of contaminated soil from the vadose zone and treatment of any remaining contaminated soils that are adjacent to the source area to achieve a carbon tetrachloride concentration below 200 {micro}g/kg. Secondary to the soil remediation is the remediation of groundwater at and adjacent to the source areas. The LDB technology serves the following purposes: (1) The physical removal of contaminated soil from the identified source area. (2) Replacement of less permeable native materials (silty clay, clayey silt, and silty sand) with more permeable materials to facilitate the capture of volatilized contaminants in the vertical borehole. (3) Removal of contaminants volatilized by air sparging (AS) and extracted from the

  17. Design of Parallel Electrical Resistance Tomography System for Measuring Multiphase Flow

    Institute of Scientific and Technical Information of China (English)

    董峰; 许聪; 张志强; 任尚杰

    2012-01-01

    ERT(electrical resistance tomography) is effective method for visualization of multiphase flows,offering some advantages of rapid response and low cost,so as to explore the transient hydrodynamics.Aiming at this target,a fully programmable and reconfigurable FPGA(field programmable gate array)-based Compact PCI(peripheral component interconnect) bus linked sixteen-channel ERT system has been presented.The data acquisition system is carefully designed with function modules of signal generator module;Compact PCI transmission module and data processing module(including data sampling,filtering and demodulating).The processing module incorporates a powerful FPGA with Compact PCI bus for communication,and the measurement process management is conducted in FPGA.Image reconstruction algorithms with different speed and accuracy are also coded for this system.The system has been demonstrated in real time(1400 frames per second for 50 kHz excitation) with signal-noise-ratio above 62 dB and repeatability error below 0.7%.Static experiments have been conducted and the images manifested good resolution relative to the actual object distribution.The parallel ERT system has provided alternative experimental platform for the multiphase flow measurements by the dynamic experiments in terms of concentration and velocity.

  18. Circularity measuring system: A shape gauge designed especially for use on large objects

    Science.gov (United States)

    Rohrkaste, G. R.

    1990-04-01

    The Circularity Measuring System (CMS) was developed to make an in-situ determination of shape similarity for selected fit large cylinders (RSRM segments). It does this to a repeatable accuracy of 0.10 mm (0.004 inch). This is less that the goal of 0.07 mm (0.003 inch), but was determined adequate because of the addition of an assembly aid that increased the entry chamfer of the clevis side of the joint. The usefulness of the CMS is demonstrated by the application to measurements other than its specified design purpose, such as submarine hull circularity, SRM mid-case circularity, as well as circularity of interfacing SRM tooling, specifically the rounding devices and horizontal disassembly devices. Commercialization of the tool is being pursued, since it is an enhancement of metrology technology for circularity determination. The most accurate in-situ technology it replaces is determined from a template. The CMS is an improvement in accuracy and operation.

  19. Modeling of snow avalanches for protection measures designing

    Science.gov (United States)

    Turchaninova, Alla; Lazarev, Anton; Loginova, Ekaterina; Seliverstov, Yuri; Glazovskaya, Tatiana; Komarov, Anton

    2017-04-01

    Avalanche protection structures such as dams have to be designed using well known standard engineering procedures that differ in different countries. Our intent is to conduct a research on structural avalanche protection measures designing and their reliability assessment during the operation using numerical modeling. In the Khibini Mountains, Russia, several avalanche dams have been constructed at different times to protect settlements and mining. Compared with other mitigation structures dams are often less expensive to construct in mining regions. The main goal of our investigation was to test the capabilities of Swiss avalanche dynamics model RAMMS and Russian methods to simulate the interaction of avalanches with mitigation structures such as catching and reflecting dams as well as to reach the observed runout distances after the transition through a dam. We present the RAMMS back-calculation results of an artificially triggered and well-documented catastrophic avalanche occurred in the town of Kirovsk, Khibini Mountains in February 2016 that has unexpectedly passed through a system of two catching dams and took the lives of 3 victims. The estimated volume of an avalanche was approximately 120,000 m3. For the calculation we used a 5 m DEM including catching dams generated from field measurements in summer 2015. We simulated this avalanche (occurred below 1000 m.a.s.l.) in RAMMS having taken the friction parameters (µ and ζ) from the upper altitude limit (above 1500 m.a.s.l.) from the table recommended for Switzerland (implemented into RAMMS) according to the results of our previous research. RAMMS reproduced the observed avalanche behavior and runout distance. No information is available concerning the flow velocity; however, calculated values correspond in general to the values measured in this avalanche track before. We applied RAMMS using an option of adding structures to DEM (including a dam in GIS) in other to test other operating catching dams in

  20. 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.

  1. Joint modeling of repeated multivariate cognitive measures and competing risks of dementia and death: a latent process and latent class approach.

    Science.gov (United States)

    Proust-Lima, Cécile; Dartigues, Jean-François; Jacqmin-Gadda, Hélène

    2016-02-10

    Joint models initially dedicated to a single longitudinal marker and a single time-to-event need to be extended to account for the rich longitudinal data of cohort studies. Multiple causes of clinical progression are indeed usually observed, and multiple longitudinal markers are collected when the true latent trait of interest is hard to capture (e.g., quality of life, functional dependency, and cognitive level). These multivariate and longitudinal data also usually have nonstandard distributions (discrete, asymmetric, bounded, etc.). We propose a joint model based on a latent process and latent classes to analyze simultaneously such multiple longitudinal markers of different natures, and multiple causes of progression. A latent process model describes the latent trait of interest and links it to the observed longitudinal outcomes using flexible measurement models adapted to different types of data, and a latent class structure links the longitudinal and cause-specific survival models. The joint model is estimated in the maximum likelihood framework. A score test is developed to evaluate the assumption of conditional independence of the longitudinal markers and each cause of progression given the latent classes. In addition, individual dynamic cumulative incidences of each cause of progression based on the repeated marker data are derived. The methodology is validated in a simulation study and applied on real data about cognitive aging obtained from a large population-based study. The aim is to predict the risk of dementia by accounting for the competing death according to the profiles of semantic memory measured by two asymmetric psychometric tests.

  2. Efficacy of wearing compression garments during post-exercise period after two repeated bouts of strenuous exercise: a randomized crossover design in healthy, active males.

    Science.gov (United States)

    Goto, Kazushige; Mizuno, Sahiro; Mori, Ayaka

    2017-12-01

    The efficacy of wearing [a] compression garment (CG) between repeated bouts of exercise within a same day has not been fully understood. The present study determined the effect of wearing a CG after strenuous exercise sessions (consisting of sprint exercise, resistance exercise, drop jump) twice a day on exercise performance, muscle damage, and inflammatory responses. Eleven physically active males (age, 22.7 ± 0.9 years; height, 175.7 ± 6.7 cm; body mass, 73.6 ± 10.2 kg; BMI, 23.8 ± 2.7 kg/m(2)) performed two trials (a randomized crossover design), consisting of the trial with either wearing a whole-body CG during post-exercise period (CG trial) or the trial with wearing a normal garment without specific pressure (CON trial). Two exercise sessions were conducted in the morning (09:00-10:00, Ex1) and afternoon (14:00-15:00, Ex2). Immediately after completing 60 min of each exercise, the subjects in the CG trial changed into a whole-body CG. Time-course changes in exercise performance (bench press power, jump performances, repeated sprint ability), blood variables (lactate, glucose, myoglobin, creatine kinase, interleukin-6, leptin), and scores of subjective feeling (fatigue, muscle soreness) were compared between the CG and CON trials before Ex1 (8:40), immediately before Ex2 (14:00, 4 h after Ex1), 4 h after Ex2 (19:00), and 24 h after the onset of Ex1 (9:00). Two bouts of exercise significantly decreased performances of counter movement jump (main effect for time: P = 0.04, F = 3.75, partial η (2) = 0.27) and rebound jump (main effect for time: P = 0.00, F = 12.22, partial η (2) = 0.55), while no significant difference was observed between the two trials (interaction: P = 0.10, F = 1.96, partial η (2) = 0.16 for counter movement jump, P = 0.93, F = 0.01, partial η (2) = 0.001 for rebound jump). Repeated sprint ability (power output during 10 × 6 s maximal sprint, 30-s rest

  3. Optimizing electromagnetic levitation design to enhance thermodynamic measurement

    Science.gov (United States)

    Royer, Zachary L.

    Here we consider two studies which show how computer modeling and simulation can be used to study aspects of material science for which experimental methods would be time consuming or difficult. In the first we examined the optimization of electromagnetic levitation coils, for reduced sample temperature, through the development of a genetic algorithm and a rigorous analytical model. In the development of the analytical model for levitation, we propose a new model for the heating effect from a design consisting of a series of co-axial circular loops. With the new model we are better able to predict sample temperatures as compared with existing models. The new model is incorporated into a robust genetic algorithm to produce a powerful and generic design tool for the creation of levitation coils. Using this new design tool we seek to expand the range of temperatures (specifically to lower temperatures) and materials that are able to be studied using EML. In the second study, we examine the growth of a grain structure in the presence of second phase particles that act as pinning agents. The existing models of grain growth with pinning agents have thus far focused on particle distributions at the extremes of grain boundary correlation. When experimental measurements at the limits of correlation are compared to the appropriate models, they have shown good agreement but seem to suggest that there is a transition in behavior between the limits but the nature and mechanisms are not well known. As such we look to study pinning agent distributions centered around the initial grain boundaries and varied in such a way as to examine the transition from high to low boundary correlation. The results show that the average grain size varies smoothly during the transition. However, the results also show that there is an anomalous increase in grain size, when the boundary region containing pinning agents is slightly larger than the diffuse boundary width from the phase-field model and

  4. Thermal design and turbidity sensor for autonomous bacterial growth measurements in spaceflight.

    Science.gov (United States)

    van Benthem, Roel; Krooneman, Janneke; de Grave, Wubbo; Hammenga-Dorenbos, Hilma

    2009-04-01

    For application of biological air filters in manned spacecraft, research on bacterial growth is carried out under microgravity conditions. For the BIOFILTER experiment, flown in 2005 on FOTON M2, eight turbidity sensors to measure the growth rate of the bacterium Xanthobacter autotrophicus GJ10 were used. Also thermal management provisions were implemented to control the internal temperature. The design and performance of the BIOFILTER equipment as well as results of the biological ground reference experiments performed in 2006 are discussed. High-performance thermal (vacuum) insulation (lambda= 0.7 mW/mK) and phase change material were implemented, keeping the BIOFILTER internal temperature below 16 degrees C during the 4-day integration period between transport and launch. After launch, in microgravity, the growth of X. autotrophicus GJ10 was successfully triggered by a temperature increase by using an internal heater to 26 degrees C. Although the operation of the sensor electronics was not fully satisfying, the bacterial growth was measured with the sensors, revealing growth rates between 0.046 and 0.077 h(-1) in microgravity, that is, approximately 1.5-2.5 times slower than routinely measured on Earth under optimal laboratory conditions. For the ground-reference experiments the equipment box, containing the eight sensors, was placed on a random positioning machine performing random rotations at 0.5 degrees /min (settling compensation) and 90 degrees /min (microgravity simulation) while the environment was controlled, accurately repeating the BIOFILTER internal temperature profile. Despite the rotation speed differences, growth rates of 0.115 h(-1) were confirmed by both the ground reference experiments. Biological interpretation of the measurements is, however, compromised owing to poor mixing and other unknown physical and biological phenomena that need to be addressed for further space experiments using these kinds of systems.

  5. DESIGNING COMPANY PERFORMANCE MEASUREMENT SYSTEM USING BALANCE SCORECARD APPROACH

    Directory of Open Access Journals (Sweden)

    Cecep Mukti Soleh

    2015-05-01

    Full Text Available This research aimed to design how to measure company performance by using balance scorecard approach in coal transportation services industry. Depth interview was used to obtain qualitative data determination of strategic objectives, key performance indicators, strategic initiatives, and in charge units for each balanced scorecard perspectives while the quantitative data were obtained from weighting through questionnaires and analyzed using paired comparison to get a perspective what mostly affected the performance of the company. To measure the achievement of corporate performance, each KPI used (1 the scoring system with the methods that higher is better, lower is better and precise is better; (2 traffic light system with the help of green, yellow, red for identification of target achievement. This research result shows that in the balance scorecard perspective, the most influences on the overall performance of the company include the customer's perspective (31%, financial perspective (29%, internal business processes (21%, learning, and growth 19%. Keywords: balance scorecard, paired comparison, coal transportation serviceABSTRAKPenelitian ini bertujuan untuk merancang pengukuran kinerja perusahaan dengan menggunakan pendekatan balance scorecard di industri jasa pengangkutan batu bara. Data kualitatif diperoleh melalui indepth interview digunakan untuk menentukan sasaran strategik, indikator kinerja utama, inisiatif strategi dan penanggungjawab setiap divisi setiap perspektif balance scorecard, sedangkan data kuantitatif digunakan untuk pembobotan melalui kuesioner dan dianalisis dengan menggunakan metode paired comparisson untuk mendapatkan perspektif yang paling berpengaruh terhadap kinerja perusahaan. Ukuran pencapaian kinerja perusahaan dari setiap KPI menggunakan; (1 scoring system dengan bantuan metode higher is better, lower is better dan precise is better;(2 traffic light system dengan menggunakan bantuan warna hijau, kuning, merah

  6. Design of instantaneous liquid film thickness measurement system for conductive or non-conductive fluid with high viscosity

    Directory of Open Access Journals (Sweden)

    Yongxin Yu

    2017-06-01

    Full Text Available In the paper, a new capacitive sensor with a dielectric film coating was designed to measure the thickness of the liquid film on a flat surface. The measured medium can be conductive or non-conductive fluid with high viscosity such as silicone oil, syrup, CMC solution and melt. With the dielectric film coating, the defects caused by the humidity in a capacitor can be avoided completely. With a excitation frequency 0-20kHz, the static permittivity of capacitive sensor is obtained and stable when small thicknesses are monitored within the frequency of 0-3kHz. Based on the measurement principle, an experimental system was designed and verified including calibration and actual measurement for different liquid film thickness. Experimental results showed that the sensitivity, the resolution, repeatability and linear range of the capacitive sensor are satisfied to the liquid film thickness measurement. Finally, the capacitive measuring system was successfully applied to the water, silicone oil and syrup film thickness measurement.

  7. Measurement-Based Performance Evaluation of Advanced MIMO Transceiver Designs

    Science.gov (United States)

    Trautwein, Uwe; Schneider, Christian; Thomä, Reiner

    2005-12-01

    This paper describes the methodology and the results of performance investigations on a multiple-input multiple-output (MIMO) transceiver scheme for frequency-selective radio channels. The method relies on offline simulations and employs real-time MIMO channel sounder measurement data to ensure a realistic channel modeling. Thus it can be classified in between the performance evaluation using some predefined channel models and the evaluation of a prototype hardware in field experiments. New aspects for the simulation setup are discussed, which are frequently ignored when using simpler model-based evaluations. Example simulations are provided for an iterative ("turbo") MIMO equalizer concept. The dependency of the achievable bit error rate performance on the propagation characteristics and on the variation in some system design parameters is shown, whereas the antenna constellation is of particular concern for MIMO systems. Although in many of the considered constellations turbo MIMO equalization appears feasible in real field scenarios, there exist cases with poor performance as well, indicating that in practical applications link adaptation of the transmitter and receiver processing to the environment is necessary.

  8. Measurement-Based Performance Evaluation of Advanced MIMO Transceiver Designs

    Directory of Open Access Journals (Sweden)

    Schneider Christian

    2005-01-01

    Full Text Available This paper describes the methodology and the results of performance investigations on a multiple-input multiple-output (MIMO transceiver scheme for frequency-selective radio channels. The method relies on offline simulations and employs real-time MIMO channel sounder measurement data to ensure a realistic channel modeling. Thus it can be classified in between the performance evaluation using some predefined channel models and the evaluation of a prototype hardware in field experiments. New aspects for the simulation setup are discussed, which are frequently ignored when using simpler model-based evaluations. Example simulations are provided for an iterative ("turbo" MIMO equalizer concept. The dependency of the achievable bit error rate performance on the propagation characteristics and on the variation in some system design parameters is shown, whereas the antenna constellation is of particular concern for MIMO systems. Although in many of the considered constellations turbo MIMO equalization appears feasible in real field scenarios, there exist cases with poor performance as well, indicating that in practical applications link adaptation of the transmitter and receiver processing to the environment is necessary.

  9. The Design and Measurement of Molecular Electronic Switches and Memories

    Science.gov (United States)

    Reed, Mark

    2000-03-01

    Electron transport studies in molecular-scale systems have recently become possible with the utilization of advanced microfabrication and self-assembly techniques. We have performed the measurement of the conductance of a single molecule using a break junction technique [1], the demonstration of molecular diodes [2], and the systematic investigation of metal-molecule contacts in a variety of systems [3]. Most recently, we have observed [4] large and useful reversible switching behavior in an electronic device that utilizes molecules as the active component, specifically a nitroamine redox center. The molecular device exhibits negative differential resistance (NDR) and peak-to-valley ratios exceeding 1000:1 and exceeds that observed in typical solid state quantum well resonant tunneling heterostructures. The designs of molecular switches, memories, and their circuit applications will be discussed. 1. M. A. Reed et al., Science 278, 252 (1997). 2. C. Zhou et al., Appl. Phys. Lett. 71, 611 (1997). 3. J. Chen et al., Chem Phys Lett 313, 741 (1999). 4. J. Chen et al., Science 286, 1550 (1999).

  10. Pelvic Floor Disorders Registry: Study Design and Outcome Measures.

    Science.gov (United States)

    Weber LeBrun, Emily; Adam, Rony A; Barber, Matthew D; Boyles, Sarah Hamilton; Iglesia, Cheryl B; Lukacz, Emily S; Moalli, Pamela; Moen, Michael D; Richter, Holly E; Subak, Leslee L; Sung, Vivian W; Visco, Anthony G; Bradley, Catherine S

    2016-01-01

    Pelvic floor disorders affect up to 24% of adult women in the United States, and many patients with pelvic organ prolapse (POP) choose to undergo surgical repair to improve their quality of life. While a variety of surgical repair approaches and techniques are utilized, including mesh augmentation, there is limited comparative effectiveness and safety outcome data guiding best practice. In conjunction with device manufacturers, federal regulatory organizations, and professional societies, the American Urogynecologic Society developed the Pelvic Floor Disorders Registry (PFDR) designed to improve the quality of POP surgery by facilitating quality improvement and research on POP treatments. The PFDR will serve as a resource for surgeons interested in benchmarking and outcomes data and as a data repository for Food and Drug Administration-mandated POP surgical device studies. Provider-reported clinical data and patient-reported outcomes will be collected prospectively at baseline and for up to 3 years after treatment. All data elements including measures of success, adverse events, and surgeon characteristics were identified and defined within the context of the anticipated multifunctionality of the registry, and with collaboration from multiple stakeholders. The PFDR will provide a platform to collect high-quality, standardized patient-level data from a variety of nonsurgical (pessary) and surgical treatments of POP and other pelvic floor disorders. Data from this registry may be used to evaluate short- and longer-term treatment outcomes, patient-reported outcomes, and complications, as well as to identify factors associated with treatment success and failure with the overall goal of improving the quality of care for women with these conditions.

  11. Evaluation of Diversity Antenna Designs Using Ray Tracing, Measured Radiation Patterns, and MIMO Channel Measurements

    Directory of Open Access Journals (Sweden)

    Arindam Pal

    2007-01-01

    Full Text Available This paper presents an evaluation of the MIMO performance of three candidate antenna array designs, each embedded within a PDA footprint, using indoor wideband channel measurements at 5.2 GHz alongside channel simulations. A channel model which employs the plane-wave approximation was used to combine the embedded antenna radiation patterns of the candidate devices obtained from far-field pattern measurements and multipath component parameters from an indoor ray-tracer. The 4-element candidate arrays were each constructed using a different type of antenna element, and despite the diverse element directivities, pattern characteristics, and polarization purities, all three devices were constructed to fully exploit diversity in polarization, space, and angle. Thus, low correlation and high information theoretic capacity was observed in each case. A good match between the model and the measurements is also demonstrated, especially for 2×2 MIMO subsets of identically or orthogonally polarized linear slot antennas. The interdependencies between the channel XPD, directional spread and pathloss, and the respective impact on channel capacity are also discussed in this paper.

  12. Evaluation of Diversity Antenna Designs Using Ray Tracing, Measured Radiation Patterns, and MIMO Channel Measurements

    Directory of Open Access Journals (Sweden)

    Pal Arindam

    2007-01-01

    Full Text Available This paper presents an evaluation of the MIMO performance of three candidate antenna array designs, each embedded within a PDA footprint, using indoor wideband channel measurements at 5.2 GHz alongside channel simulations. A channel model which employs the plane-wave approximation was used to combine the embedded antenna radiation patterns of the candidate devices obtained from far-field pattern measurements and multipath component parameters from an indoor ray-tracer. The 4-element candidate arrays were each constructed using a different type of antenna element, and despite the diverse element directivities, pattern characteristics, and polarization purities, all three devices were constructed to fully exploit diversity in polarization, space, and angle. Thus, low correlation and high information theoretic capacity was observed in each case. A good match between the model and the measurements is also demonstrated, especially for MIMO subsets of identically or orthogonally polarized linear slot antennas. The interdependencies between the channel XPD, directional spread and pathloss, and the respective impact on channel capacity are also discussed in this paper.

  13. Automatic swirl angle measurements for pump intake design

    NARCIS (Netherlands)

    Fockert, A. de; Westende, J.M.C. van 't; Verhaart, F.I.H.

    2014-01-01

    Pre-swirl occurring in pump intake basins influences pump efficiency and lifetime. The exact effect on a pump depends on the pump design. In order to optimize the approach flow towards the pump, physical scale modelling is often applied following the guidelines formulated in pump intake design

  14. Software Design for an Airborne Gravity Measurement System

    Science.gov (United States)

    1987-08-12

    surveys we have used a linear phase filter design program [10]. When calculated, filtered gravity should be stored in the space reserved for it in...1981. 10. J. H. McClellan, T. W. Parks, and L. R. Rabiner, "FIR Linear Phase Filter Design Program," in Programs for Digital Signal Processing (IEEE

  15. Automatic swirl angle measurements for pump intake design

    NARCIS (Netherlands)

    Fockert, A. de; Westende, J.M.C. van 't; Verhaart, F.I.H.

    2014-01-01

    Pre-swirl occurring in pump intake basins influences pump efficiency and lifetime. The exact effect on a pump depends on the pump design. In order to optimize the approach flow towards the pump, physical scale modelling is often applied following the guidelines formulated in pump intake design stand

  16. Association of Repeatedly Measured High-Sensitivity-Assayed Troponin I with Cardiovascular Disease Events in a General Population from the MORGAM/BiomarCaRE Study

    DEFF Research Database (Denmark)

    Hughes, Maria F; Ojeda, Francisco; Saarela, Olli;

    2017-01-01

    BACKGROUND: High-sensitivity troponin I (hs-cTnI) concentrations reflect myocardial stress. The role of hs-cTnI in predicting long-term changes in the risk of cardiovascular disease (CVD) in general populations is not clearly defined. METHODS: We investigated whether the change in 3 repeated meas...

  17. Representivity of wind measurements for design wind speed estimations

    CSIR Research Space (South Africa)

    Goliger, Adam M

    2013-07-01

    Full Text Available of instrumentation sited according to World Meteorological Organization (WMO) requirements. With the advent of automatic weather station technology several decades ago, wind measurements have become much more cost-effective. While previously wind measurements were...

  18. Design of a mobile hydrological data measurement system

    Science.gov (United States)

    Liu, Yunping; Wang, Tianmiao; Dai, Fenfen

    2017-06-01

    The current hydrological data acquisition is mainly used in the instrument measurement. Instrument measurement equipment is mainly fixed in a certain water area and the device is easy to be lost. In view of a series of problems, the dynamic measurement system is established by the method of unmanned surface vessel and embedded technology, which can realize any positions measurement of a lake. This method has many advantages, such as mobile convenience, saving money and so on.

  19. The Bolund experiment - design of measurement campaign using CFD

    DEFF Research Database (Denmark)

    Bechmann, Andreas; Johansen, Jeppe; Sørensen, Niels N.

    the upcoming measurement campaign. The simulation results are used for estimating rational positions of measuring masts and instrumentation. A total of ten measuring masts are proposed consisting of two 16 m masts, six 9 m masts and two 5 m masts. The masts are instrumented with 12 cup anemometers for mean...

  20. Repeated electromagnetic induction measurements for mapping soil moisture at the field scale: comparison with data from a wireless soil moisture monitoring network

    Science.gov (United States)

    Martini, Edoardo; Werban, Ulrike; Zacharias, Steffen; Pohle, Marco; Dietrich, Peter; Wollschläger, Ute

    2016-04-01

    Electromagnetic induction (EMI) methods are widely used for soil mapping, as they allow fast and relatively low-cost surveys of soil apparent electrical conductivity (ECa) at various scales. Soil ECa is well known to be influenced by both the volumetric content and the electrical conductivity (EC) of soil water, as well as by soil temperature and by the volume of the solid particles and their EC. Among other applications, EMI has become widely used to determine soil water content or to study hydrological processes within the field of hydrogeophysics. Although the use of non-invasive EMI for imaging soil spatial properties is very attractive, the dependence of ECa on several properties and states challenges any interpretation with respect to individual soil properties or states such as θ. The major aim of this study was to further investigate the potential of repeated EMI measurements to map soil moisture at the hillslope scale, with particular focus on the temporal variability of the spatial patterns of ECa and soil moisture, respectively, and on the stability of the ECa-soil moisture relationship over time. To this end, we compared time series of EMI measurements with high-resolution soil moisture data for a non-intensively managed hillslope area in the Schäfertal catchment (Central Germany) for which the spatial distribution of soil properties and soil water dynamics were known in detail. Soil water and temperature dynamics were observed in 40 soil profiles at hourly resolution during 14 months using a wireless monitoring network. During this period of time, ECa was mapped on seven occasions using an EM38-DD device. For the investigated site, ECa showed small temporal variations (ranging between 0 and 24 mS/m) whereas the temporal range of soil moisture was very large (from very dry to soil saturation). Furthermore, temporal changes of the spatial pattern of ECa differed from temporal changes of the spatial pattern of soil moisture. The ECa-soil moisture

  1. Towards a Sustainable Design for Maturity Measurement Marketplace

    DEFF Research Database (Denmark)

    Lasrado, Lester; Vatrapu, Ravi; Kærsgaard, Henrik Bjerre

    2016-01-01

    In this research-in-progress paper, we propose a solution in form of an IT artefact to address both theoretical and practical challenges faced by maturity model designers. We identify and list out the existing challenges & criticisms of maturity models research through an extensive literature...... review, followed by semi-structured interviews with four maturity model designers. We also explore different motivations of building a maturity model, and using them further scope the boundaries of our solution....

  2. Mining of simple sequence repeats in the Genome of Gentianaceae

    Directory of Open Access Journals (Sweden)

    R Sathishkumar

    2011-01-01

    Full Text Available Simple sequence repeats (SSRs or short tandem repeats are short repeat motifs that show high level of length polymorphism due to insertion or deletion mutations of one or more repeat types. Here, we present the detection and abundance of microsatellites or SSRs in nucleotide sequences of Gentianaceae family. A total of 545 SSRs were mined in 4698 nucleotide sequences downloaded from the National Center for Biotechnology Information (NCBI. Among the SSR sequences, the frequency of repeat type was about 429 -mono repeats, 99 -di repeats, 15 -tri repeats, and 2 --hexa repeats. Mononucleotide repeats were found to be abundant repeat types, about 78%, followed by dinucleotide repeats (18.16% among the SSR sequences. An attempt was made to design primer pairs for 545 identified SSRs but these were found only for 169 sequences.

  3. Automated quality checks on repeat prescribing.

    OpenAIRE

    Rogers, Jeremy E; Wroe, Christopher J; Roberts, Angus; Swallow, Angela; Stables, David; Cantrill, Judith A; Rector, Alan L.

    2003-01-01

    BACKGROUND: Good clinical practice in primary care includes periodic review of repeat prescriptions. Markers of prescriptions that may need review have been described, but manually checking all repeat prescriptions against the markers would be impractical. AIM: To investigate the feasibility of computerising the application of repeat prescribing quality checks to electronic patient records in United Kingdom (UK) primary care. DESIGN OF STUDY: Software performance test against benchmark manual...

  4. Design of a compact, low-price, lifetime measuring instrument

    Science.gov (United States)

    Draxler, Sonja; Lippitsch, Max E.; Moeller, Reinhard; Tafeit, Erwin

    1994-08-01

    The technical requirements for a small, rugged, and moderately- priced device for measuring fluorescence lifetimes have been investigated. The suitability and performance of various lifetime measuring schemes were compared. Based on these investigations a compact time-domain instrument was developed allowing measurement of fluorescence decays with a time resolution well below 1 ns. A semiconductor laser (frequency-doubled, if necessary) is used as a light source. Detection is done with a miniaturized photomultiplier. In favorable cases measurement of a fluorescent decay curve is accomplished within less than one minute.

  5. Measuring LEED–NC applicability in design for hospitality

    Directory of Open Access Journals (Sweden)

    Teresa Marie Cracknell

    2015-12-01

    Full Text Available Mounting awareness of climate change in recent years has led the construction industry to initiate new approaches toward sustainable building design, yet stakeholders in hospitality development still hesitate to build green. This reluctance is due to perceived high guest expectations of comfort levels and amenity access among these properties. Research was conducted to determine precisely which green building innovations present the most significant barriers to incorporating sustainability into design for hospitality. Average LEED credit implementation rates among 28 existing LEED hotel projects were calculated and compared with average credits employed among common commercial building projects. 15 of those projects’ designers also offered survey opinions on which sustainable innovations were most commonly avoided in their approaches for hospitality. The results indicate that certain credits do experience decreased popularity among hospitality projects, yet guest comfort was not the only barrier identified. Cost of implementation and local applicability affected by climate and local bylaws were also found as major role players in the selection of credits specific to hospitality design. Conclusions are presented according to the data and recommendations made to support further growth and success in future applications of LEED sustainable design in hospitality.

  6. Evaluating Nanoparticle Sensor Design for Intracellular pH Measurements

    DEFF Research Database (Denmark)

    Benjaminsen, Rikke Vicki; Sun, Honghao; Henriksen, Jonas Rosager

    2011-01-01

    and there is a need to improve measurement methodology. In the present paper, we have successfully carried out time resolved pH measurements in endosomes and lyosomes in living cells using nanoparticle sensors and show the importance of sensor choice for successful quantification. We have studied two nanoparticle...

  7. A Novel Analog Integrated Circuit Design Course Covering Design, Layout, and Resulting Chip Measurement

    Science.gov (United States)

    Lin, Wei-Liang; Cheng, Wang-Chuan; Wu, Chen-Hao; Wu, Hai-Ming; Wu, Chang-Yu; Ho, Kuan-Hsuan; Chan, Chueh-An

    2010-01-01

    This work describes a novel, first-year graduate-level analog integrated circuit (IC) design course. The course teaches students analog circuit design; an external manufacturer then produces their designs in three different silicon chips. The students, working in pairs, then test these chips to verify their success. All work is completed within…

  8. A Novel Analog Integrated Circuit Design Course Covering Design, Layout, and Resulting Chip Measurement

    Science.gov (United States)

    Lin, Wei-Liang; Cheng, Wang-Chuan; Wu, Chen-Hao; Wu, Hai-Ming; Wu, Chang-Yu; Ho, Kuan-Hsuan; Chan, Chueh-An

    2010-01-01

    This work describes a novel, first-year graduate-level analog integrated circuit (IC) design course. The course teaches students analog circuit design; an external manufacturer then produces their designs in three different silicon chips. The students, working in pairs, then test these chips to verify their success. All work is completed within…

  9. Quantum repeated games revisited

    CERN Document Server

    Frackiewicz, Piotr

    2011-01-01

    We present a scheme for playing quantum repeated 2x2 games based on the Marinatto and Weber's approach to quantum games. As a potential application, we study twice repeated Prisoner's Dilemma game. We show that results not available in classical game can be obtained when the game is played in the quantum way. Before we present our idea, we comment on the previous scheme of playing quantum repeated games.

  10. Body measurement s in relation to cockpit design

    Directory of Open Access Journals (Sweden)

    P.V. Krishna Iyer

    1966-01-01

    Full Text Available The paper deals with the major conclusions arising from the statistical analysis of 22 body Measurements of 691 airmen. Besides the upper and lower 95 per rent confidence limits for these characters, the regression equations for (i body a-eight on the measurement of abdomen, shoulder, elbow, seat maximum below hips and total height and (ii total height on knee height and thigh height, have also been given.

  11. Design of precision measurement circuits for the relative humidity

    Science.gov (United States)

    Wang, Yanpeng; Gao, Guanwang; Sha, Zhanyou

    2009-07-01

    The two methods of the relative humidity measurement are introduced in this paper. The one is adopting transistor and operational amplifier to compose a logarithmic amplifier, by which to realize the linearization of exponent mode character curve of moisture-sensitive resistor. And using the positive temperature coefficient of the adjustable current source (+0.33%/°C) compensate the negative temperature coefficient of the thermistor (-0.36%/°C). Zero temperature drift is realized by the methods and the measurement accuracy reached +/-2%. The two is adopting intelligent temperature/relative humidity sensor, which combined the multiple parameter sensor and transmitter, to realize the accurately measurement not only of the relative humidity, but also of the temperature and dew point. Through the 2-wires serial port the system can be connected to MCS-51 MCU. The accuracy of the relative humidity measurement is +/-1.8% the nonlinear error can be reduced to +/-0.1% after software arithmetic compensation. The temperature range measured is -40{ + 123.8°C. The accuracy of dew point measurement is ?+/-1°C

  12. PGNAA system preliminary design and measurement of In-Hospital Neutron Irradiator for boron concentration measurement.

    Science.gov (United States)

    Zhang, Zizhu; Chong, Yizheng; Chen, Xinru; Jin, Congjun; Yang, Lijun; Liu, Tong

    2015-12-01

    A prompt gamma neutron activation analysis (PGNAA) system has been recently developed at the 30-kW research reactor In-Hospital Neutron Irradiator (IHNI) in Beijing. Neutrons from the specially designed thermal neutron beam were used. The thermal flux of this beam is 3.08×10(6) cm(-2) s(-1) at a full reactor power of 30 kW. The PGNAA system consists of an n-type high-purity germanium (HPGe) detector of 40% efficiency, a digital spectrometer, and a shielding part. For both the detector shielding part and the neutron beam shielding part, the inner layer is composed of (6)Li2CO3 powder and the outer layer lead. The boron-10 sensitivity of the PGNAA system is approximately 2.5 cps/ppm. Two calibration curves were produced for the 1-10 ppm and 10-50 ppm samples. The measurement results of the control samples were in accordance with the inductively coupled plasma atomic emission spectroscopy (ICP-AES) results.

  13. Phase equilibrium measurements and modelling for separation process design

    Energy Technology Data Exchange (ETDEWEB)

    Dell' Era, C.

    2012-07-01

    the thermodynamic representation of the equilibrium between phases. For this purpose an extensive experimental work was performed, comprising of vapour-liquid, gas-liquid and solid-liquid equilibrium measurements. Vapour liquid equilibrium of binary mixtures of butane + alcohols was measured with a static total pressure apparatus due to the importance of hydrocarbon and alcohol mixtures in the production of biofuels. The same equipment was used to measure binary systems of diethyl sulphide + C4 - hydrocarbons of importance in refinery applications. The activity coefficients of these systems were modelled with activity coefficients models. The absorption of carbon dioxide in alkanolamine solutions is the leading technology for the removal of carbon dioxide during refining of gas and oil. In recent years, this technology has gained importance also for carbon capture from large point sources. The scarcity of experimental data for some alkanolamine systems affected the accuracy of thermodynamic models. Several experimental techniques were developed to supply new experimental data for aqueous solutions of diisopropanolamine (DIPA) and methyldiethanolamine (MDEA). The solubility of carbon dioxide in solutions of these amines was measured with a static total pressure apparatus for gas solubility, and with a bubbling apparatus. The density of carbonated aqueous DIPA was also measured and modelled. The vapour-liquid equilibrium of water + DIPA and water + MDEA was measured with a static total pressure apparatus. The solid-liquid equilibrium of the same systems was measured with a visual method and a Differential Scanning Calorimeter. The activity coefficients of aqueous DIPA and MDEA solutions were modelled using NRTL, thus providing the first model of this sort for DIPA. A new model of the Henry's law constant of carbon dioxide in binary and ternary aqueous solutions of alkanolamines was developed at temperatures up to 393 K. (orig.)

  14. Effects of repeated Valsalva maneuver straining on cardiac and vasoconstrictive baroreflex responses.

    Science.gov (United States)

    Convertino, Victor A; Ratliff, Duane A; Doerr, Donald F; Ludwig, David A; Muniz, Gary W; Benedetti, Erik; Chavarria, Jose; Koreen, Susan; Nguyen, Claude; Wang, Jeff

    2003-03-01

    We hypothesized that repeated respiratory straining maneuvers (repeated SM) designed to elevate arterial BPs (arterial baroreceptor loading) would acutely increase baroreflex responses. We tested this hypothesis by measuring cardiac baroreflex responses to carotid baroreceptor stimulation (neck pressures), and changes in heart rate and diastolic BP after reductions in BP induced by a 15-s Valsalva maneuver in 10 female and 10 male subjects at 1, 3, 6, and 24 h after performing repeated SM. Baroreflex responses were also measured in each subject at 1, 3, 6, and 24 h at the same time on a separate day without repeated SM (control) in a randomized, counter-balanced cross-over experimental design. There was no statistical difference in carotid-cardiac and peripheral vascular baroreflex responses measured across time following repeated SM compared with the control condition. Integrated cardiac baroreflex response (deltaHR/ deltaSBP) measured during performance of a Valsalva maneuver was increased by approximately 50% to 1.1 +/- 0.2 bpm x mm Hg(-1) at 1 h and 1.0 +/- 0.1 bpm x mm Hg(-1) at 3 h following repeated SM compared with the control condition (0.7 +/- 0.1 bpm x mm Hg(-1) at both 1 and 3 h, respectively). However, integrated cardiac baroreflex response after repeated SM returned to control levels at 6 and 24 h after training. These responses did not differ between men and women. Our results are consistent with the notion that arterial baroreceptor loading induced by repeated SM increased aortic, but not carotid, cardiac baroreflex responses for as long as 3 h after repeated SM. We conclude that repeated SM increases cardiac baroreflex responsiveness which may provide patients, astronauts, and high-performance aircraft pilots with protection from development of orthostatic hypotension.

  15. How Good is Your User Experience? Measuring and Designing Interactions

    Directory of Open Access Journals (Sweden)

    Wildner Raimund

    2015-11-01

    Full Text Available Form and function are important dimensions of consumer choice, but there is more in our increasingly digital world. It is not only products per se that need to be designed but the whole interaction between consumers and brands. The whole UX or user experience is more important than ever before. Digitalism nowadays is everywhere, and even mundane products are becoming more digital (e.g. ovens, while others evolve that are purely digital (e.g. PayPal.

  16. Critical current measurement for design of HTS DC power cables

    Science.gov (United States)

    Watanabe, Hirofumi

    2017-02-01

    Critical currents of HTS DC power cables were calculated. In the calculation a relationship between critical current density and magnetic flux density proposed by Gömöry et al. [1] was used and the parameters used in the relationship were obtained by the critical current measurements with respect to the external magnetic field for a sample of the HTS tape. Numerical models of cables were composed and their critical currents were calculated, which showed the strong dependence on the arrangement of the HTS tapes in the cable. Critical current measurements of model cables assembled based on the calculations showed that the measured critical currents also depended on the arrangement of the HTS tapes strongly. The calculated results were compared with the experimental results, which showed that the experimental results agreed well with the calculated results.

  17. A Design of WCDMA RF Transceiver with Its Performance Measuring

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A 2-GHz radio frequency transceiver is presented and implemented for third generation mobile communications using wide-band code division multiple access (WCDMA) scheme. Performance measuring systems are introduced for transmitter channel and receiver sensitivity, respectively. The transceiver achieves maximum output power of 22 dBm, dynamic range of 85 dB, adjacent channel power rejection ratio (ACPR) of -41dB@5MHz, and receiver sensitivity of -119.6 dBm for 128-kb/s data at 3.84-Mcps spreading rate. The measured results indicate the conformity to the required commercial 2.0-GHz WCDMA specification and 3GPP requirements.

  18. Design of measurement equipment for high power laser beam shapes

    DEFF Research Database (Denmark)

    Hansen, K. S.; Olsen, F. O.; Kristiansen, Morten

    2013-01-01

    To analyse advanced high power beam patterns, a method, which is capable of analysing the intensity distribution in 3D is needed. Further a measuring of scattered light in the same system is preferred. This requires a high signal to noise ratio. Such a system can be realised by a CCD-chip impleme......To analyse advanced high power beam patterns, a method, which is capable of analysing the intensity distribution in 3D is needed. Further a measuring of scattered light in the same system is preferred. This requires a high signal to noise ratio. Such a system can be realised by a CCD...

  19. Experimental Designs for Binary Data in Switching Measurements on Superconducting Josephson Junctions

    OpenAIRE

    Karvanen, Juha; Vartiainen, Juha J.; Timofeev, Andrey; Pekola, Jukka

    2006-01-01

    We study the optimal design of switching measurements of small Josephson junction circuits which operate in the macroscopic quantum tunnelling regime. Starting from the D-optimality criterion we derive the optimal design for the estimation of the unknown parameters of the underlying Gumbel type distribution. As a practical method for the measurements, we propose a sequential design that combines heuristic search for initial estimates and maximum likelihood estimation. The presented design has...

  20. Discrepancies in reporting the CAG repeat lengths for Huntington's disease

    DEFF Research Database (Denmark)

    Quarrell, Oliver W; Handley, Olivia; O'Donovan, Kirsty

    2011-01-01

    Huntington's disease results from a CAG repeat expansion within the Huntingtin gene; this is measured routinely in diagnostic laboratories. The European Huntington's Disease Network REGISTRY project centrally measures CAG repeat lengths on fresh samples; these were compared with the original...

  1. Evaluation of repeated measurements of radon-222 concentrations in well water sampled from bedrock aquifers of the Piedmont near Richmond, Virginia, USA: effects of lithology and well characteristics.

    Science.gov (United States)

    Harris, Shelley A; Billmeyer, Ernest R; Robinson, Michael A

    2006-07-01

    Radon (222Rn) concentrations in 26 ground water wells of two distinct lithologies in the Piedmont of Virginia were measured to assess variation in ground water radon concentrations (GWRC), to evaluate differences in concentrations related to well characteristics, lithology, and spatial distributions, and to assess the feasibility of predicting GWRC. Wells were sampled in accordance with American Public Health Association Method 7500 Rn-B, with modifications to include a well shaft profile analysis that determined the minimum purge time sufficient to remove the equivalent of one column of water from each well. Statistically significant differences in GWRC were found in the Trssu (1482 +/- 1711 pCi/L) and Mpg (7750 +/- 5188 pCi/L) lithologies, however, no significant differences were found among GWRC at each well over time. Using multiple regression, 86% of the variability (R2) in the GWRC was explained by the lithology, latitudinal class, and water table elevation of the wells. The GWRC in a majority of the wells studied exceed US Environmental Protection Agency designated maximum contaminant level and AMCL. Results support modifications to sampling procedures and indicate that, in previous studies, variations in GWRC concentrations over time may have been due in part to differences in sampling procedures and not in source water.

  2. Automated Measurement of Visual Acuity in Pediatric Ophthalmic Patients Using Principles of Game Design and Tablet Computers.

    Science.gov (United States)

    Aslam, Tariq M; Tahir, Humza J; Parry, Neil R A; Murray, Ian J; Kwak, Kun; Heyes, Richard; Salleh, Mahani M; Czanner, Gabriela; Ashworth, Jane

    2016-10-01

    To report on the utility of a computer tablet-based method for automated testing of visual acuity in children based on the principles of game design. We describe the testing procedure and present repeatability as well as agreement of the score with accepted visual acuity measures. Reliability and validity study. Setting: Manchester Royal Eye Hospital Pediatric Ophthalmology Outpatients Department. Total of 112 sequentially recruited patients. For each patient 1 eye was tested with the Mobile Assessment of Vision by intERactIve Computer for Children (MAVERIC-C) system, consisting of a software application running on a computer tablet, housed in a bespoke viewing chamber. The application elicited touch screen responses using a game design to encourage compliance and automatically acquire visual acuity scores of participating patients. Acuity was then assessed by an examiner with a standard chart-based near ETDRS acuity test before the MAVERIC-C assessment was repeated. Reliability of MAVERIC-C near visual acuity score and agreement of MAVERIC-C score with near ETDRS chart for visual acuity. Altogether, 106 children (95%) completed the MAVERIC-C system without assistance. The vision scores demonstrated satisfactory reliability, with test-retest VA scores having a mean difference of 0.001 (SD ±0.136) and limits of agreement of 2 SD (LOA) of ±0.267. Comparison with the near EDTRS chart showed agreement with a mean difference of -0.0879 (±0.106) with LOA of ±0.208. This study demonstrates promising utility for software using a game design to enable automated testing of acuity in children with ophthalmic disease in an objective and accurate manner. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. A numerical technique to design blast noise mitigation measures

    NARCIS (Netherlands)

    Berg, F. van den; Eerden, F.J.M. van der

    2007-01-01

    Large weapons, such as armor, artillery or demolitions, create a high-energy blast wave. It has a low frequency content, typically between 15 and 125 Hz, and can propagate over large distances. As a result it is a relative important cause for annoyance. Mitigation measures need to be close to the so

  4. Design parameters for measurements of local catalytic activity on surfaces

    DEFF Research Database (Denmark)

    Johansson, Martin; Johannessen, Tue; Jørgensen, Jan Hoffmann;

    2006-01-01

    Computational fluid dynamics in combination with experiments is used to characterize a gas sampling device for measurements of the local catalytic activity on surfaces. The device basically consists of a quartz capillary mounted concentrically inside an aluminum tube. Reactant gas is blown toward...

  5. A numerical technique to design blast noise mitigation measures

    NARCIS (Netherlands)

    Berg, F. van den; Eerden, F.J.M. van der

    2007-01-01

    Large weapons, such as armor, artillery or demolitions, create a high-energy blast wave. It has a low frequency content, typically between 15 and 125 Hz, and can propagate over large distances. As a result it is a relative important cause for annoyance. Mitigation measures need to be close to the

  6. Conceptual design of a measurement network of the global change

    Science.gov (United States)

    Hari, P.; Petäjä, T.; Bäck, J.; Kerminen, V.-M.; Lappalainen, H. K.; Vihma, T.; Laurila, T.; Viisanen, Y.; Vesala, T.; Kulmala, M.

    2016-01-01

    The global environment is changing rapidly due to anthropogenic emissions and actions. Such activities modify aerosol and greenhouse gas concentrations in the atmosphere, leading to regional and global climate change and affecting, e.g., food and fresh-water security, sustainable use of natural resources and even demography. Here we present a conceptual design of a global, hierarchical observation network that can provide tools and increased understanding to tackle the inter-connected environmental and societal challenges that we will face in the coming decades. The philosophy behind the conceptual design relies on physical conservation laws of mass, energy and momentum, as well as on concentration gradients that act as driving forces for the atmosphere-biosphere exchange. The network is composed of standard, flux and/or advanced and flagship stations, each of which having specific and identified tasks. Each ecosystem type on the globe has its own characteristic features that have to be taken into consideration. The hierarchical network as a whole is able to tackle problems related to large spatial scales, heterogeneity of ecosystems and their complexity. The most comprehensive observations are envisioned to occur in flagship stations, with which the process-level understanding can be expanded to continental and global scales together with advanced data analysis, Earth system modelling and satellite remote sensing. The denser network of the flux and standard stations allows application and up-scaling of the results obtained from flagship stations to the global level.

  7. Comparison of visibility measurement techniques for forklift truck design factors.

    Science.gov (United States)

    Choi, Chin-Bong; Park, Peom; Kim, Young-Ho; Susan Hallbeck, M; Jung, Myung-Chul

    2009-03-01

    This study applied the light bulb shadow test, a manikin vision assessment test, and an individual test to a forklift truck to identify forklift truck design factors influencing visibility. The light bulb shadow test followed the standard of ISO/DIS 13564-1 for traveling and maneuvering tests with four test paths (Test Nos. 1, 3, 4, and 6). Digital human and forklift truck models were developed for the manikin vision assessment test with CATIA V5R13 human modeling solutions. Six participants performed the individual tests. Both employed similar parameters to the light bulb shadow test. The individual test had better visibility with fewer numbers and a greater distribution of the shadowed grids than the other two tests due to eye movement and anthropometric differences. The design factors of load backrest extension, lift chain, hose, dashboard, and steering wheel should be the first factors considered to improve visibility, especially when a forklift truck mainly performs a forward traveling task in an open area.

  8. Mature clustered, regularly interspaced, short palindromic repeats RNA (crRNA) length is measured by a ruler mechanism anchored at the precursor processing site.

    Science.gov (United States)

    Hatoum-Aslan, Asma; Maniv, Inbal; Marraffini, Luciano A

    2011-12-27

    Precise RNA processing is fundamental to all small RNA-mediated interference pathways. In prokaryotes, clustered, regularly interspaced, short palindromic repeats (CRISPR) loci encode small CRISPR RNAs (crRNAs) that protect against invasive genetic elements by antisense targeting. CRISPR loci are transcribed as a long precursor that is cleaved within repeat sequences by CRISPR-associated (Cas) proteins. In many organisms, this primary processing generates crRNA intermediates that are subject to additional nucleolytic trimming to render mature crRNAs of specific lengths. The molecular mechanisms underlying this maturation event remain poorly understood. Here, we defined the genetic requirements for crRNA primary processing and maturation in Staphylococcus epidermidis. We show that changes in the position of the primary processing site result in extended or diminished maturation to generate mature crRNAs of constant length. These results indicate that crRNA maturation occurs by a ruler mechanism anchored at the primary processing site. We also show that maturation is mediated by specific cas genes distinct from those genes involved in primary processing, showing that this event is directed by CRISPR/Cas loci.

  9. Measuring Radionuclides in the environment: radiological quantities and sampling designs

    Energy Technology Data Exchange (ETDEWEB)

    Voigt, G. [ed.] [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz

    1998-10-01

    One aim of the workshop was to support and provide an ICRU report committee (International Union of Radiation Units) with actual information on techniques, data and knowledge of modern radioecology when radionuclides are to be measured in the environment. It has been increasingly recognised that some studies in radioecology, especially those involving both field sampling and laboratory measurements, have not paid adequate attention to the problem of obtaining representative, unbiased samples. This can greatly affect the quality of scientific interpretation, and the ability to manage the environment. Further, as the discipline of radioecology has developed, it has seen a growth in the numbers of quantities and units used, some of which are ill-defined and which are non-standardised. (orig.)

  10. Design of geometric phase measurement in EAST Tokamak

    CERN Document Server

    Lan, T; Liu, J; Jie, Y X; Wang, Y L; Gao, X; Qin, H

    2016-01-01

    The optimum scheme for geometric phase measurement in EAST Tokamak is proposed in this paper. The theoretical values of geometric phase for the probe beams of EAST Polarimeter-Interferometer (POINT) system are calculated by path integration in parameter space. Meanwhile, the influences of some controllable parameters on geometric phase are evaluated. The feasibility and challenge of distinguishing geometric effect in the POINT signal are also assessed in detail.

  11. Microphone Array Design Measures for Hands-Free Speech Recognition

    OpenAIRE

    井上 雅晶; 山田 武志; 中村, 哲; 鹿野 清宏

    1998-01-01

    One of the key technologies for natural man-machine interface is hands-free speech recognition. The performance of hands-free distant- talking speech recognition will be seriously degraded by noise and reverberation in real environments. A microphone array is applied to solve the problem. When applying a microphone array to speech recognition, parameters such as number of microphone elements and their spacing interval affect the performance. In order to optimize these parameters, a measure wh...

  12. Security Problems of Scan Design and Accompanying Measures

    Science.gov (United States)

    Biasizzo, Anton; Novak, Franc

    2016-05-01

    The paper deals with the security problems of scan design and investigates currently proposed solutions. A solution based on data encryption to protect the data in scan chains is discussed and problems related to the block-based encoding are outlined. Next, security extension for IEEE Std. 1149.1 providing a locking mechanism is analysed. The mechanism prevents unauthorised users to interfere via test bus with the system normal operation. Possible attack scenario is considered and the probabilities of successful attack within a given time interval are calculated for different lengths of the Lock register. The paper concludes with the description of current work focused on improvements the security of the locking mechanism, in particular by using simplified public key infrastructure.

  13. Design and interpretation of experiments to measure the effective removal section.

    CERN Document Server

    Desdin, L

    2001-01-01

    Paper is devoted to develop a single analytical instrument to design and interpret experiment to measure the neutron removal cross sections. There were analyzed the influence of the geometrical and nuclear parameters into the neutron removal cross sections values measured

  14. UK 2009-2010 repeat station report

    Directory of Open Access Journals (Sweden)

    Thomas J.G. Shanahan

    2013-03-01

    Full Text Available The British Geological Survey is responsible for conducting the UK geomagnetic repeat station programme. Measurements made at the UK repeat station sites are used in conjunction with the three UK magnetic observatories: Hartland, Eskdalemuir and Lerwick, to produce a regional model of the local field each year. The UK network of repeat stations comprises 41 stations which are occupied at approximately 3-4 year intervals. Practices for conducting repeat station measurements continue to evolve as advances are made in survey instrumentation and as the usage of the data continues to change. Here, a summary of the 2009 and 2010 UK repeat station surveys is presented, highlighting the measurement process and techniques, density of network, reduction process and recent results.

  15. Design Parameter Studies of Emission-Based Iron Opacity Measurements

    Science.gov (United States)

    Martin, Madison E.; London, Richard A.; Goluoglu, Sedat; Whitley, Heather D.

    2016-10-01

    Opacity is a critical parameter in the transport of radiation in systems such as inertial confinement fusion capsules and stars. The resolution of current disagreements between solar models and helioseismological observations would benefit from experimental validation of theoretical opacity models. Short pulse lasers can be used to heat targets to higher temperatures and densities than long pulse lasers and pulsed power machines, thus potentially enabling access to x-ray emission spectra at conditions relevant to solar models. The radiation-hydrodynamic code HYDRA is used to investigate the effects of modifying laser energy, laser pulse length, and target dimensions on the plasma conditions, x-ray emission, and inferred opacity of a buried layer iron target. The accuracy of the opacity inference is sensitive to tamper emission and optical depth effects. An example design that reaches temperatures and densities relevant to the radiative zone of the sun while reducing optical depth and tamper emission effects will be discussed. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC.

  16. The 2-degree Field Lensing Survey: design and clustering measurements

    CERN Document Server

    Blake, Chris; Childress, Michael; Erben, Thomas; Glazebrook, Karl; Harnois-Deraps, Joachim; Heymans, Catherine; Hildebrandt, Hendrik; Hinton, Samuel R; Janssens, Steven; Johnson, Andrew; Joudaki, Shahab; Klaes, Dominik; Kuijken, Konrad; Lidman, Chris; Marin, Felipe A; Parkinson, David; Poole, Gregory B; Wolf, Christian

    2016-01-01

    We present the 2-degree Field Lensing Survey (2dFLenS), a new galaxy redshift survey performed at the Anglo-Australian Telescope. 2dFLenS is the first wide-area spectroscopic survey specifically targeting the area mapped by deep-imaging gravitational lensing fields, in this case the Kilo-Degree Survey. 2dFLenS obtained 70,079 redshifts in the range z < 0.9 over an area of 731 sq deg, and is designed to extend the datasets available for testing gravitational physics and promote the development of relevant algorithms for joint imaging and spectroscopic analysis. The redshift sample consists first of 40,531 Luminous Red Galaxies (LRGs), which enable analyses of galaxy-galaxy lensing, redshift-space distortion, and the overlapping source redshift distribution by cross-correlation. An additional 28,269 redshifts form a magnitude-limited (r < 19.5) nearly-complete sub-sample, allowing direct source classification and photometric-redshift calibration. In this paper, we describe the motivation, target selection...

  17. Hysteresis of magnetostructural transitions: Repeatable and non-repeatable processes

    Energy Technology Data Exchange (ETDEWEB)

    Provenzano, Virgil [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Della Torre, Edward; Bennett, Lawrence H. [Department of Electrical and Computer Engineering, The George Washington University, Washington, DC 20052 (United States); ElBidweihy, Hatem, E-mail: Hatem@gwmail.gwu.edu [Department of Electrical and Computer Engineering, The George Washington University, Washington, DC 20052 (United States)

    2014-02-15

    The Gd{sub 5}Ge{sub 2}Si{sub 2} alloy and the off-stoichiometric Ni{sub 50}Mn{sub 35}In{sub 15} Heusler alloy belong to a special class of metallic materials that exhibit first-order magnetostructural transitions near room temperature. The magnetic properties of this class of materials have been extensively studied due to their interesting magnetic behavior and their potential for a number of technological applications such as refrigerants for near-room-temperature magnetic refrigeration. The thermally driven first-order transitions in these materials can be field-induced in the reverse order by applying a strong enough field. The field-induced transitions are typically accompanied by the presence of large magnetic hysteresis, the characteristics of which are a complicated function of temperature, field, and magneto-thermal history. In this study we show that the virgin curve, the major loop, and sequentially measured MH loops are the results of both repeatable and non-repeatable processes, in which the starting magnetostructural state, prior to the cycling of field, plays a major role. Using the Gd{sub 5}Ge{sub 2}Si{sub 2} and Ni{sub 50}Mn{sub 35}In{sub 15} alloys, as model materials, we show that a starting single phase state results in fully repeatable processes and large magnetic hysteresis, whereas a mixed phase starting state results in non-repeatable processes and smaller hysteresis.

  18. Reconfigurable multiport EPON repeater

    Science.gov (United States)

    Oishi, Masayuki; Inohara, Ryo; Agata, Akira; Horiuchi, Yukio

    2009-11-01

    An extended reach EPON repeater is one of the solutions to effectively expand FTTH service areas. In this paper, we propose a reconfigurable multi-port EPON repeater for effective accommodation of multiple ODNs with a single OLT line card. The proposed repeater, which has multi-ports in both OLT and ODN sides, consists of TRs, BTRs with the CDR function and a reconfigurable electrical matrix switch, can accommodate multiple ODNs to a single OLT line card by controlling the connection of the matrix switch. Although conventional EPON repeaters require full OLT line cards to accommodate subscribers from the initial installation stage, the proposed repeater can dramatically reduce the number of required line cards especially when the number of subscribers is less than a half of the maximum registerable users per OLT. Numerical calculation results show that the extended reach EPON system with the proposed EPON repeater can save 17.5% of the initial installation cost compared with a conventional repeater, and can be less expensive than conventional systems up to the maximum subscribers especially when the percentage of ODNs in lightly-populated areas is higher.

  19. Design and measurement of a 53 GHz balanced Colpitts oscillator

    Institute of Scientific and Technical Information of China (English)

    Zhao Yan; Wang Zhigong; Li Wei; Zhang Li

    2009-01-01

    A 53 GHz Colpitts oscillator implemented in a SiGe:C BiCMOS technology is presented. Limited by a 26.5 GHz frequency analyzer, the oscillator was measured indirectly through an on-chip mixer. The mixer down-converted the oscillating frequency to an intermediate frequency (IF) below 26.5 GHz. By adjusting the local os-cillating (LO) frequency and recording the changes of IF frequency, the oscillator's output frequency (RF) was determined. Additionally, using phase noise theory of mixers, the oscillator's phase noise was estimated as-58 dBc/Hz at 1 MHz offset and the output power was about-21 dBm. The chip is 270×480 μm in size.

  20. Computational device design: measuring esophageal distensibility using EndoFLIP

    Science.gov (United States)

    Acharya, Shashank; Kou, Wenjun; Kahrilas, Peter J.; Pandolfino, John E.; Patankar, Neelesh A.

    2016-11-01

    Characterizing the strength of sphincters in the human body is valuable from a diagnostic and surgical standpoint. We develop a numerical model for the EndoFLIP device (Endolumenal Functional Lumen Imaging Probe) that is crucial to the biomechanical study of the Lower Esophageal Sphincter (LES). The simulations demonstrate how the device operates in vivo. From this model, we suggest additional use cases for the device that can give insight into the state of the esophageal wall. Currently, the device measures a single steady quantity (distensibility) that is calculated from pressure and area. Our analysis shows that by capturing and analyzing spatio-temporal pressure variations during peristalsis, the effectiveness of the contractions and health of the surrounding tissue can be quantified. Furthermore, there is an opportunity to validate tissue models by comparing dilation results with clinical data from the device. This work is supported by the Cabell Fellowship at Northwestern Unviersity.

  1. Optimal Design of Measurement Programs for the Parameter Identification of Dynamic Systems

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard; Brincker, Rune

    1991-01-01

    The design of a measurement program devoted to parameter identification of structural dynamic systems is considered. The design problem is formulated as an optimization problem to minimize the total expected cost, i.e. the cost of failure and the cost of the measurement program. All the calculati...

  2. Design of an E-ELT M1 segment measurement machine with nanometer accuracy

    NARCIS (Netherlands)

    Bos, A.; Henselmans, R.; Rosielle, P.C.J.N.; Steinbuch, M.; Voert, M.J.A. te

    2014-01-01

    The baseline design of the European Extremely Large Telescope features a telescope with a 39-meter-class primary mirror (M1), consisting of 798 hexagonal segments. A measurement machine design is presented based on a non-contact single-point scanning technique, capable of measuring the form error of

  3. A Repeating Fast Radio Burst

    CERN Document Server

    Spitler, L G; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-01-01

    Fast Radio Bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measures (i.e. integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of the fast radio bursts has led several authors to hypothesise that they originate in cataclysmic astrophysical events. Here we report the detection of ten additional bursts from the direction of FRB121102, using the 305-m Arecibo telescope. These new bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and wh...

  4. Software design for a database driven system for accelerator magnet measurements

    Energy Technology Data Exchange (ETDEWEB)

    Brown, B.C.; Bleadon, M.E.; Glass, H.D.; Glosson, R.; Hanft, R.W.; Harding, D.J.; Mazur, P.O.; Pachnik, J.E.; Sim, J.W.; Trombly-Freytag, K.; Walbridge, D.G.

    1991-05-01

    Measurements of more than 1000 new magnets are needed for the Main Injector Project at Fermilab. In order to achieve efficiency and accuracy in measurements, we chose a database driven design for control of the measurement system. We will use a relational database to describe the measurement subjects and equipment. A logbook system defined in the database will provide for prescription of measurements to be carried out, description of measurements as they are carried out, and a comment database for less structured information. The operator interface will be built on X-windows. This paper will describe our system design. 2 refs.

  5. Design and Measurement Methodology for a Sub-picoampere Current Digitiser

    CERN Document Server

    Voulgari, Evgenia; Anghinolfi, Francis; Krummenacher, François; Kayal, Maher

    2015-01-01

    This paper introduces some design and measurement techniques that were used in the design and the testing of an ASIC for ultra-low current sensing. The idea behind this paper is to present the limitations in sub-picoampere current measurements and demonstrate an ASIC that can accurately measure the different sources of leakage currents and the methodology of measuring. Then the leakage current can be subtracted or compensated in order to accurately measure the ultra-low current that is generated from a sensor/detector. The proposed ASIC can measure currents as low as -50 fA, a value well below similar ASIC implementations.

  6. Using Tests Designed to Measure Individual Sensorimotor Subsystem Perfomance to Predict Locomotor Adaptability

    Science.gov (United States)

    Peters, B. T.; Caldwell, E. E.; Batson, C. D.; Guined, J. R.; DeDios, Y. E.; Stepanyan, V.; Gadd, N. E.; Szecsy, D. L.; Mulavara, A. P.; Seidler, R. D.; Bloomberg, J. J.

    2014-01-01

    Astronauts experience sensorimotor disturbances during the initial exposure to microgravity and during the readapation phase following a return to a gravitational environment. These alterations may lead to disruption in the ability to perform mission critical functions during and after these gravitational transitions. Astronauts show significant inter-subject variation in adaptive capability following gravitational transitions. The way each individual's brain synthesizes the available visual, vestibular and somatosensory information is likely the basis for much of the variation. Identifying the presence of biases in each person's use of information available from these sensorimotor subsystems and relating it to their ability to adapt to a novel locomotor task will allow us to customize a training program designed to enhance sensorimotor adaptability. Eight tests are being used to measure sensorimotor subsystem performance. Three of these use measures of body sway to characterize balance during varying sensorimotor challenges. The effect of vision is assessed by repeating conditions with eyes open and eyes closed. Standing on foam, or on a support surface that pitches to maintain a constant ankle angle provide somatosensory challenges. Information from the vestibular system is isolated when vision is removed and the support surface is compromised, and it is challenged when the tasks are done while the head is in motion. The integration and dominance of visual information is assessed in three additional tests. The Rod & Frame Test measures the degree to which a subject's perception of the visual vertical is affected by the orientation of a tilted frame in the periphery. Locomotor visual dependence is determined by assessing how much an oscillating virtual visual world affects a treadmill-walking subject. In the third of the visual manipulation tests, subjects walk an obstacle course while wearing up-down reversing prisms. The two remaining tests include direct

  7. Repeatability of Harris Corner Detector

    Institute of Scientific and Technical Information of China (English)

    HU Lili

    2003-01-01

    Interest point detectors are commonly employed to reduce the amount of data to be processed. The ideal interest point detector would robustly select those features which are most appropriate or salient for the application and data at hand. This paper shows that interest points are geometrically stable under different transformations.This property makes interest points very successful in the context of image matching. To measure this property quantatively, we introduce a evaluation criterion: repeatability rate.

  8. Relationships between anthropometric measures and athletic performance, with special reference to repeated-sprint ability, in the Qatar national soccer team.

    Science.gov (United States)

    Brocherie, Franck; Girard, Olivier; Forchino, Fabricio; Al Haddad, Hani; Dos Santos, Gilvan A; Millet, Grégoire P

    2014-01-01

    The aim of this study was to determine potential relationships between anthropometric parameters and athletic performance with special consideration to repeated-sprint ability (RSA). Sixteen players of the senior male Qatar national soccer team performed a series of anthropometric and physical tests including countermovement jumps without (CMJ) and with free arms (CMJwA), straight-line 20 m sprint, RSA (6 × 35 m with 10 s recovery) and incremental field test. Significant (P sprinting times and r = 0.54 for maximal sprinting speed) with the exception of the sprint decrement score (Sdec). The sum of six skinfolds and adipose mass index were largely correlated with Sdec (r = 0.68, P 0.05, respectively) or any standard athletic tests. Multiple regression analyses indicated that muscular cross-sectional area for mid-thigh, adipose index, straight-line 20 m time, maximal sprinting speed and CMJwA are the strongest predictors of Sdec (r(2) = 0.89) and TT (r(2) = 0.95) during our RSA test. In the Qatar national soccer team, players' power-related qualities and RSA are associated with a high muscular profile and a low adiposity. This supports the relevance of explosive power for the soccer players and the larger importance of neuromuscular qualities determining the RSA.

  9. 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.

  10. Electrostatic design of the barrel CRID (Cherenkov Ring Imaging Detector) and associated measurements

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H. (Tohoku Univ., Sendai (Japan). Dept. of Physics); Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dunwoodie, W.; Hallewell, G.; Kawahara, H.; Kwon, Y.; Leith, D.W.G.S.; Muller, D.; Nagamine, T.; Pavel, T.; Ratcliff, B.; Rensing, P.; Schultz, D.; Shapiro, S.; Simopoulos, C.; Solodov, E.; Toge, N.; Va' Vra, J. Williams, H. (Stanford Linear Accelerator Center, Menlo Park, CA (US

    1990-04-01

    We report on the electrostatic design and related measurements of the barrel Cherenkov Ring Imaging Detector for the Stanford Large Detector experiment at the Stanford Linear Accelerator Center Linear Collider. We include test results of photon feedback in TMAE-laden gas, distortion measurements in the drift boxes and corona measurements. 13 refs., 21 figs.

  11. Electrostatic design of the barrel CRID (Cherenkov Ring Imaging Detector) and associated measurements

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H. (Tohoku Univ., Sendai (Japan). Dept. of Physics); Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dunwoodie, W.; Hallewell, G.; Kawahara, H.; Kwon, Y.; Leith, D.W.G.S.; Muller, D.; Nagamine, T.; Pavel, T.; Ratcliff, B.; Rensing, P.; Schultz, D.; Shapiro, S.; Simopoulos, C.; Solodov, E.; Toge, N.; Va' Vra, J. Williams, H. (Stanford Linear Accelerator Center, Menlo Park, CA (US

    1990-04-01

    We report on the electrostatic design and related measurements of the barrel Cherenkov Ring Imaging Detector for the Stanford Large Detector experiment at the Stanford Linear Accelerator Center Linear Collider. We include test results of photon feedback in TMAE-laden gas, distortion measurements in the drift boxes and corona measurements. 13 refs., 21 figs.

  12. Waveform measurement in mocrowave device characterization: impact on power amplifiers design

    Directory of Open Access Journals (Sweden)

    Roberto Quaglia

    2016-07-01

    Full Text Available This paper describes an example of a measurement setup enabling waveform measurements during the load-pull characterization of a microwave power device. The significance of this measurement feature is highlighted showing how waveform engineering can be exploited to design high efficiency microwave power amplifiers.

  13. Designing a Strategic Measurement Program for Software Engineering Organizations: Discovering Difficulties and Problems

    Directory of Open Access Journals (Sweden)

    Mitre-Hernández Hugo A.

    2014-04-01

    Full Text Available Software measurement is widely recognized as an essential part of understanding, controlling, monitoring, predicting, and evaluating software development and maintenance projects. Both, software process improvement (SPI and software measurement literature include many case studies of successful companies and descriptions of their measurement programs. However, there are still concerns on how to design efficient strategic measurement programs. These concerns include the lack of involvement of the SEO’s personnel, bad alignment with its strategy and improvement initiative, difficulty to justify the utility of using standards or improvement initiatives, etc. All of the former results in inadequate measurement programs that often lead to poor decisions and economic loss. This paper describes a pilot study to observe and analyze the operation of measurement teams when using measurement methods such as Balanced Objective-Quantifiers Method (BOQM, Practical Software Measurement (PSM and Balanced Scorecard and Goal-Driven Measurement (BSC&GQ[I]M to design a strategic measurement program. From the results of the study, we gained some insight on common difficulties and problems, which are useful to consider when designing of strategic measurement programs. This paper describes an important milestone in achieving our main research goal, evaluate and find suggestions to design a strategic measurement program aligned correctly with the strategic goals, for effective decision making at all organization levels and justify the utilities or benefits of integrating improvement initiatives.

  14. Detection of the effects of repeated dose combined propoxur and heavy metal exposure by measurement of certain toxicological, haematological and immune function parameters in rats.

    Science.gov (United States)

    Institóris, L; Siroki, O; Undeger, U; Basaran, N; Banerjee, B D; Dési, I

    2001-06-21

    In the present study, an immunotoxicity test system, containing general toxicological (body weight gain, organ weights), haematological (WBC,RBC, Ht, mean cell volume of the RBCs, cell content of the femoral bone marrow), and immune function (PFC assay, DTH reaction) investigations, was used for detection the effects of a 4 weeks repeated low dose combined oral exposure of male Wistar rats with propoxur and the heavy metals arsenic or mercury. Two doses of the compounds were used: a higher one (the lowest dose which resulted in significant change of at least one parameter examined in previous dose-effect experiments), and a lower one (the highest dose which proved to be non-effective). The applied doses were: 8.51 and 0.851 mg kg(-1) of propoxur, 13.3 and 3.33 mg kg(-1) of NaAsO(2), and 3.20 and 0.40 mg kg(-1) of HgCl(2). In the combination treatment, the high dose of propoxur was combined with the low dose of arsenic or mercury, and the high doses of each heavy metals were combined with the low dose of propoxur. The main finding of this study was that some of the combinations significantly altered the relative weight of liver, adrenals and kidneys, related to both the untreated and the high dose internal control. Among the immune functions examined, only the PFC content of the spleen showed a trend of changes in certain combinations versus the corresponding high dose control. According to the present results, combined exposure with propoxur and the heavy metals examined can modify the detection limit of the single compounds and/or may alter their toxic effects.

  15. Dissolved Fe(II) in the Pacific Ocean: Measurements from the P16N CLIVAR/CO2 Repeat Hydrography Cruise

    Science.gov (United States)

    Hansard, S. P.; Landing, W. M.; Measures, C. I.

    2006-12-01

    Vertical profiles of seawater Fe(II) concentration were obtained for 37 stations sampled in early 2006, in conjunction with the CLIVAR Repeat Hydrography P16N transect (152° W, Tahiti to Alaska). At each station, seawater samples were collected from 12 target depths (0-1000 m) using trace-metal clean Go-Flo bottles. Upon recovery, Go-Flo bottles were immediately transferred to a Class 100 clean van and sub-sampled for Fe(II) by passing sample water through a 0.2 μm Supor (polyethersulfone) cartridge filter into 125 mL containers, pre-loaded with 25 μL of 6M quartz-distilled HCl (final pH ~~ 6) to slow oxidation. Samples were immediately analyzed for Fe(II) using a luminol-based chemiluminescence method. Total dissolved iron was also determined shipboard by spectrophotometric flow injection analysis. The data collected from this cruise will be presented, along with corroborating data from another North Pacific cruise (PO2). Concentrations of Fe(II) ranged from below detection (meters. Photoreduction of Fe(III) has been cited as a source of Fe(II) in surface waters, and the pattern of attenuation with depth is consistent with this mechanism. Many samples collected at or near the bottom of the profile (500-1000 m) exhibited elevated Fe(II) relative to the mid-depths of the profile. Due to the higher total dissolved iron at depth, the percentage of Fe(II) was low in these samples. Recent studies support the presence of Fe(II) at depth, in association with low or suboxic conditions. In situ processes such as the remineralization of sinking biogenic particles may provide a source for this Fe(II).

  16. Optimal Design of Measurement Programs for the Parameter Identification of Dynamic Systems

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard; Brincker, Rune

    The design of a measured program devoted to parameter identification of structural dynamic systems is considered, the design problem is formulated as an optimization problem due to minimize the total expected cost of the measurement program. All the calculations are based on a priori knowledge an...... in a simply supported plane, vibrating beam model. Results show optimal number of sensors and their locations....... and engineering judgement. One of the contribution of the approach is that the optimal nmber of sensors can be estimated. This is sown in an numerical example where the proposed approach is demonstrated. The example is concerned with design of a measurement program for estimating the modal damping parameters...

  17. Two to five repeated measurements per patient reduced the required sample size considerably in a randomized clinical trial for patients with inflammatory rheumatic diseases

    OpenAIRE

    Smedslund Geir; Zangi Heidi Andersen; Mowinckel Petter; Hagen Kåre Birger

    2013-01-01

    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)...

  18. The Pentapeptide Repeat Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Vetting,M.; Hegde, S.; Fajardo, J.; Fiser, A.; Roderick, S.; Takiff, H.; Blanchard, J.

    2006-01-01

    The Pentapeptide Repeat Protein (PRP) family has over 500 members in the prokaryotic and eukaryotic kingdoms. These proteins are composed of, or contain domains composed of, tandemly repeated amino acid sequences with a consensus sequence of [S, T,A, V][D, N][L, F]-[S, T,R][G]. The biochemical function of the vast majority of PRP family members is unknown. The three-dimensional structure of the first member of the PRP family was determined for the fluoroquinolone resistance protein (MfpA) from Mycobacterium tuberculosis. The structure revealed that the pentapeptide repeats encode the folding of a novel right-handed quadrilateral {beta}-helix. MfpA binds to DNA gyrase and inhibits its activity. The rod-shaped, dimeric protein exhibits remarkable size, shape and electrostatic similarity to DNA.

  19. Repeating the Past

    Science.gov (United States)

    Moore, John W.

    1998-05-01

    As part of the celebration of the Journal 's 75th year, we are scanning each Journal issue from 25, 50, and 74 years ago. Many of the ideas and practices described are so similar to present-day "innovations" that George Santayana's adage (1) "Those who cannot remember the past are condemned to repeat it" comes to mind. But perhaps "condemned" is too strong - sometimes it may be valuable to repeat something that was done long ago. One example comes from the earliest days of the Division of Chemical Education and of the Journal.

  20. Repeatability and Minimal Detectable Change in Longitudinal Median Nerve Excursion Measures During Upper Limb Neurodynamic Techniques in a Mixed Population: A Pilot Study Using Musculoskeletal Ultrasound Imaging.

    Science.gov (United States)

    Paquette, Philippe; Lamontagne, Martin; Higgins, Johanne; Gagnon, Dany H

    2015-07-01

    This study determined test-retest reliability and minimum detectable change in longitudinal median nerve excursion during upper limb neurodynamic tests (ULNTs). Seven participants with unilateral or bilateral carpal tunnel syndrome and 11 healthy participants were randomly tested with two ULNTs (i.e., tensioner and slider). Each ULNT was performed three times each at 45° and 90° of shoulder abduction on two separate visits. Video sequences of median nerve excursion, recorded by a physical therapist using ultrasound imaging, were quantified using computer software. The generalizability theory, encompassing a G-Study and a D-study, measured the dependability coefficient (Φ) along with standard error of measurement (SEM) accuracy and allowed various testing protocols to be proposed. The highest reliability (Φ = 0.84) and lowest minimal measurement error (SEM = 0.58 mm) of the longitudinal median nerve excursion were reached during the ULNT-slider performed with 45° of shoulder abduction and when measures obtained from three different image sequences recorded during a single visit were averaged. It is recommended that longitudinal median nerve excursion measures computed from three separate image sequences recorded during a single visit be averaged in clinical practice. Ideally, adding a second visit (six image sequences) is also suggested in research protocols.

  1. Aerosol measurements at the Southern Great Plains Site: Design and surface installation

    Energy Technology Data Exchange (ETDEWEB)

    Leifer, R.; Knuth, R.H.; Guggenheim, S.F.; Albert, B. [Department of Energy, New York, NY (United States)

    1996-04-01

    To impropve the predictive capabilities of the Atmospheric Radiation Measurements (ARM) program radiation models, measurements of awserosol size distributions, condensation particle concentrations, aerosol scattering coefficients at a number of wavelenghts, and the aerosol absorption coefficients are needed at the Southern Great Plains (SGP) site. Alos, continuous measurements of ozone concnetrations are needed for model validation. The environmental Measuremenr Laboratory (EMK) has the responsibility to establish the surface aerosol measurements program at the SGP site. EML has designed a special sampling manifold.

  2. New approach to the design of digital algorithms for electric power measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kezunovic, M. (Texas A and M Univ., TX (US)); Perunicic, B. (Univ. of Sarajevo (YU))

    1991-04-01

    This paper introduces a new approach to the design of digital algorithms for electric power measurements. Digital algorithms for electric power measurements are represented as 2D digital FIR filters applied on voltage and current samples. Based on this approach, a new technique for algorithm design is developed. As the main advantage, the technique provides a convenient way to design new algorithms for measuring the electric power components according to various definitions in both sinusoidal and non-sinusoidal conditions. Several new algorithms are derived by using the proposed design technique. The existing algorithms for power measurements are also derived by using the new approach. The algorithm performance is tested using actual signal recordings.

  3. Size Design of CdZnTe Detector Shield for Measuring Burnup of Spent Fuel

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>It is important to measure the burnup of spent fuel for nuclear safeguards, burnup credit and critical safety in spent-fuel reprocessing process. The purpose of this work is designing a portable device to

  4. Auroral Electrojet Index Designed to Provide a Global Measure, Hourly Intervals, of Auroral Zone Magnetic Activity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Auroral Electrojet (AE) index is designed to provide a global quantitative measure of auroral zone magnetic activity produced by enhanced ionospheric currents...

  5. Scan posture definition and hip girth measurement: the impact on clothing design and body scanning.

    Science.gov (United States)

    Gill, Simeon; Parker, Christopher J

    2016-11-15

    Ergonomic measurement is central to product design and development; especially for body worn products and clothing. However, there is a large variation in measurement definitions, complicated by new body scanning technology that captures measurements in a posture different to traditional manual methods. Investigations of hip measurement definitions in current clothing measurement practices supports analysis of the effect of scan posture and hip measurement definition on the circumferences of the hip. Here, the hip girth is a key clothing measurement that is not defined in current body scanning measurement standards. Sixty-four participants were scanned in the standard scan posture of a [TC](2) body scanner, and also in a natural posture similar to that of traditional manual measurement collection. Results indicate that scan posture affects hip girth circumferences, and that some current clothing measurement practices may not define the largest lower body circumference. Recommendations are made concerning how the hip is defined in measurement practice and within body scanning for clothing product development. Practitioner Summary: The hip girth is an important measurement in garment design, yet its measurement protocol is not currently defined. We demonstrate that body posture during body scanning affects hip circumferences, and that current clothing measurement practices may not define the largest lower body circumference. This paper also provides future measurement practice recommendations.

  6. Impact of volunteer-related and methodology-related factors on the reproducibility of brachial artery flow-mediated vasodilation: analysis of 672 individual repeated measurements.

    NARCIS (Netherlands)

    Mil, A.C.C.M. van; Greyling, A.; Zock, P.L.; Geleijnse, J.M.; Hopman, M.T.E.; Mensink, R.P.; Reesink, K.D.; Green, D.J.; Ghiadoni, L.; Thijssen, D.H.J.

    2016-01-01

    OBJECTIVES: Brachial artery flow-mediated dilation (FMD) is a popular technique to examine endothelial function in humans. Identifying volunteer and methodological factors related to variation in FMD is important to improve measurement accuracy and applicability. METHODS: Volunteer-related and

  7. Design and implementation of a low-cost FPGA-Based bioimpedance measurement system

    OpenAIRE

    González Gutiérrez, Miguel

    2014-01-01

    Currently, many impedance measurement systems have been developed. This project details the design, implementation and characterization of a FPGA-based bioimpedance measurement system, whose goal is obtaining good performance at low costs. Signal generation and processing circuits were implemented within the FPGA, as well as the NIOS II embedded processor. An ADA conversion board as well as a front-end previously designed and implemented by the group of instrumentation and biomedical engineer...

  8. 数字光纤直放站中的时延测量与校正%The Measurement and Adjustment of Time Delay in Digital Optical Fiber Repeater

    Institute of Scientific and Technical Information of China (English)

    金绍春

    2011-01-01

    提出了应用于数字光纤直放站的时延测量与校正方法。阐述了数字光纤直放站的结构、时延测量的目的与原理、时延校正的计算。时延测量以CPRI协议为基础,包括光纤时延测量、转发时延测量。时延校正分下行时延校正和上行时延校正。下行时延校正是使同一台REC送出的IQ信号在不同的RE中能够同时射频发送出去。上行时延校正是使不同的RE接收到的IQ信号能够正确进行功率合成。%The Method of measurement and adjustment of time delay which applies to digital optical fiber repeater has been presented. The structure of digital optical fiber repeater, the purpose and principle of time delay measurement, the calculation of time delay adjustment, has been represented. The measurement of time delay that based on CPRI protocol includes the measurement of optical fiber time delay and the measurement of forward time delay. The time delay adjustment includes uplink time delay adjustment and downlink time delay adjustment. The purpose of downlink time delay adjustment is to ensure IQ signals in different REs which comes from the same REC transmit synchronously by radio frequency signals. The purpose of uplink time delay adjustment is to ensure received IQ signals by different REs synthesize correctly by power.

  9. Research Design and the Predictive Power of Measures of Self-Efficacy

    Science.gov (United States)

    Moriarty, Beverley

    2014-01-01

    The purpose of this enquiry was to examine how research design impacts on the predictive power of measures of self-efficacy. Three cautions for designing research into self-efficacy drawn from the seminal work of Albert Bandura (1986) and a further caution proposed by the current author together form the analytical framework for this enquiry. For…

  10. Research Design and the Predictive Power of Measures of Self-Efficacy

    Science.gov (United States)

    Moriarty, Beverley

    2014-01-01

    The purpose of this enquiry was to examine how research design impacts on the predictive power of measures of self-efficacy. Three cautions for designing research into self-efficacy drawn from the seminal work of Albert Bandura (1986) and a further caution proposed by the current author together form the analytical framework for this enquiry. For…

  11. All-optical repeater.

    Science.gov (United States)

    Silberberg, Y

    1986-06-01

    An all-optical device containing saturable gain, saturable loss, and unsaturable loss is shown to transform weak, distorted optical pulses into uniform standard-shape pulses. The proposed device performs thresholding, amplification, and pulse shaping as required from an optical repeater. It is shown that such a device could be realized by existing semiconductor technology.

  12. Bidirectional Manchester repeater

    Science.gov (United States)

    Ferguson, J.

    1980-01-01

    Bidirectional Manchester repeater is inserted at periodic intervals along single bidirectional twisted pair transmission line to detect, amplify, and transmit bidirectional Manchester 11 code signals. Requiring only 18 TTL 7400 series IC's, some line receivers and drivers, and handful of passive components, circuit is simple and relatively inexpensive to build.

  13. Whole scalp resting state EEG of oscillatory brain activity shows no parametric relationship with psychoacoustic and psychosocial assessment of tinnitus: A repeated measures study.

    Science.gov (United States)

    Pierzycki, Robert H; McNamara, Adam J; Hoare, Derek J; Hall, Deborah A

    2016-01-01

    Tinnitus is a perception of sound that can occur in the absence of an external stimulus. A brief review of electroencephalography (EEG) and magnetoencephalography (MEG) literature demonstrates that there is no clear relationship between tinnitus presence and frequency band power in whole scalp or source oscillatory activity. Yet a preconception persists that such a relationship exists and that resting state EEG could be utilised as an outcome measure for clinical trials of tinnitus interventions, e.g. as a neurophysiological marker of therapeutic benefit. To address this issue, we first examined the test-retest correlation of EEG band power measures in tinnitus patients (n = 42). Second we examined the evidence for a parametric relationship between numerous commonly used tinnitus variables (psychoacoustic and psychosocial) and whole scalp EEG power spectra, directly and after applying factor reduction techniques. Test-retest correlation for both EEG band power measures and tinnitus variables were high. Yet we found no relationship between whole scalp EEG band powers and psychoacoustic or psychosocial variables. We conclude from these data that resting state whole scalp EEG should not be used as a biomarker for tinnitus and that greater caution should be exercised in regard to reporting of findings to avoid confirmation bias. The data was collected during a randomised controlled trial registered at ClinicalTrials.gov (Identifier: NCT01541969).

  14. Flood Adaptation Measures Applicable in the Design of Urban Public Spaces: Proposal for a Conceptual Framework

    Directory of Open Access Journals (Sweden)

    Maria Matos Silva

    2016-07-01

    Full Text Available Assuming the importance of public space design in the implementation of effective adaptation action towards urban flooding, this paper identifies and systematizes a wide range of flood adaptation measures pertinent to the design of public spaces. It presents findings from both a systematic literature review and an empirical analysis retrieved from concrete public space design precedents. It concludes with the presentation of a conceptual framework that organizes the identified measures in accordance to their main, and secondary, infrastructural strategies. The intention behind the disclosed framework is to aid a multitude of professionals during the initial exploratory phases of public space projects that incorporate flooding adaptation capacities.

  15. 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.

  16. The child accident repeater: a review.

    Science.gov (United States)

    Jones, J G

    1980-04-01

    The child accident repeater is defined as one who has at least three accidents that come to medical attention within a year. The accident situation has features in common with those of the child who has a single accident through simple "bad luck", but other factors predispose him to repeated injury. In the child who has a susceptible personality, a tendency for accident repetition may be due to a breakdown in adjustment to a stressful environment. Prevention of repeat accidents should involve the usual measures considered appropriate for all children as well as an attempt to provide treatment of significant maladjustment and modification of a stressful environment.

  17. Accuracy optimization of high-speed AFM measurements using Design of Experiments

    DEFF Research Database (Denmark)

    Tosello, Guido; Marinello, F.; Hansen, Hans Nørgaard;

    2010-01-01

    , the estimated dimensions of measured features. The definition of scan settings is based on a comprehensive optimization that targets maximization of information from collected data and minimization of measurement uncertainty and scan time. The Design of Experiments (DOE) technique is proposed and applied...

  18. Design and construction of a Faraday cup for measurement of small electronic currents

    Science.gov (United States)

    Veyssiere, A.

    1985-01-01

    The design of a device to measure and integrate very small currents generated by the impact of a charged particle beam upon a Faraday cut is described. The main component is a graphite block capable of stopping practically all the incident changes. The associated electronic apparatus required to measure better than 10/13 ampere with a precision of 10/0 is described.

  19. Design of a Neutron Temporal Diagnostic for measuring DD or DT burn histories at the NIF

    Science.gov (United States)

    Lahmann, B.; Frenje, J. A.; Sio, H.; Petrasso, R. D.; Bradley, D. K.; Le Pape, S.; MacKinnon, A. J.; Isumi, N.; Macphee, A.; Zayas, C.; Spears, B. K.; Hermann, H.; Hilsabeck, T. J.; Kilkenny, J. D.

    2015-11-01

    The DD or DT burn history in Inertial Confinement Fusion (ICF) implosions provides essential information about implosion performance and helps to constrain numerical modeling. The capability of measuring this burn history is thus important for the NIF in its pursuit of ignition. Currently, the Gamma Reaction History (GRH) diagnostic is the only system capable of measuring the burn history for DT implosions with yields greater than ~ 1e14. To complement GRH, a new NIF Neutron Temporal Diagnostic (NTD) is being designed for measuring the DD or DT burn history with yields greater than ~ 1e10. A traditional scintillator-based design and a pulse-dilation-based design are being considered. Using MCNPX simulations, both designs have been optimized, validated and contrasted for various types of implosions at the NIF. This work was supported in part by the U.S. DOE, LLNL and LLE.

  20. Designing, Building, Measuring and Testing a Constant Equivalent Fall Height Terrain Park Jump

    CERN Document Server

    Petrone, Nicola; McNeil, James A; Hubbard, Mont

    2016-01-01

    Previous work has presented both a theoretical foundation for designing terrain park jumps that control landing impact and computer software to accomplish this task. US ski resorts have been reluctant to adopt this more engineered approach to jump design, in part due to questions of feasibility. The present study demonstrates this feasibility. It describes the design, construction, measurement and experimental testing of such a jump. It improves on previous efforts with more complete instrumentation, a larger range of jump distances, and a new method for combining jumper- and board-mounted accelerometer data to estimate equivalent fall height, a measure of impact severity. It unequivocally demonstrates the efficacy of the engineering design approach, namely that it is possible and practical to design and build free style terrain park jumps with landing surface shapes that control for landing impact as predicted by the theory.