The Cross Validation of the Attitudes toward Mainstreaming Scale (ATMS).
ERIC Educational Resources Information Center
Berryman, Joan D.; Neal, W. R. Jr.
1980-01-01
Reliability and factorial validity of the Attitudes Toward Mainstreaming Scale was supported in a cross-validation study with teachers. Three factors emerged: learning capability, general mainstreaming, and traditional limiting disabilities. Factor intercorrelations varied from .42 to .55; correlations between total scores and individual factors…
Korjus, Kristjan; Hebart, Martin N.; Vicente, Raul
2016-01-01
Supervised machine learning methods typically require splitting data into multiple chunks for training, validating, and finally testing classifiers. For finding the best parameters of a classifier, training and validation are usually carried out with cross-validation. This is followed by application of the classifier with optimized parameters to a separate test set for estimating the classifier’s generalization performance. With limited data, this separation of test data creates a difficult trade-off between having more statistical power in estimating generalization performance versus choosing better parameters and fitting a better model. We propose a novel approach that we term “Cross-validation and cross-testing” improving this trade-off by re-using test data without biasing classifier performance. The novel approach is validated using simulated data and electrophysiological recordings in humans and rodents. The results demonstrate that the approach has a higher probability of discovering significant results than the standard approach of cross-validation and testing, while maintaining the nominal alpha level. In contrast to nested cross-validation, which is maximally efficient in re-using data, the proposed approach additionally maintains the interpretability of individual parameters. Taken together, we suggest an addition to currently used machine learning approaches which may be particularly useful in cases where model weights do not require interpretation, but parameters do. PMID:27564393
Korjus, Kristjan; Hebart, Martin N; Vicente, Raul
2016-01-01
Supervised machine learning methods typically require splitting data into multiple chunks for training, validating, and finally testing classifiers. For finding the best parameters of a classifier, training and validation are usually carried out with cross-validation. This is followed by application of the classifier with optimized parameters to a separate test set for estimating the classifier's generalization performance. With limited data, this separation of test data creates a difficult trade-off between having more statistical power in estimating generalization performance versus choosing better parameters and fitting a better model. We propose a novel approach that we term "Cross-validation and cross-testing" improving this trade-off by re-using test data without biasing classifier performance. The novel approach is validated using simulated data and electrophysiological recordings in humans and rodents. The results demonstrate that the approach has a higher probability of discovering significant results than the standard approach of cross-validation and testing, while maintaining the nominal alpha level. In contrast to nested cross-validation, which is maximally efficient in re-using data, the proposed approach additionally maintains the interpretability of individual parameters. Taken together, we suggest an addition to currently used machine learning approaches which may be particularly useful in cases where model weights do not require interpretation, but parameters do.
Cross-validation pitfalls when selecting and assessing regression and classification models.
Krstajic, Damjan; Buturovic, Ljubomir J; Leahy, David E; Thomas, Simon
2014-03-29
We address the problem of selecting and assessing classification and regression models using cross-validation. Current state-of-the-art methods can yield models with high variance, rendering them unsuitable for a number of practical applications including QSAR. In this paper we describe and evaluate best practices which improve reliability and increase confidence in selected models. A key operational component of the proposed methods is cloud computing which enables routine use of previously infeasible approaches. We describe in detail an algorithm for repeated grid-search V-fold cross-validation for parameter tuning in classification and regression, and we define a repeated nested cross-validation algorithm for model assessment. As regards variable selection and parameter tuning we define two algorithms (repeated grid-search cross-validation and double cross-validation), and provide arguments for using the repeated grid-search in the general case. We show results of our algorithms on seven QSAR datasets. The variation of the prediction performance, which is the result of choosing different splits of the dataset in V-fold cross-validation, needs to be taken into account when selecting and assessing classification and regression models. We demonstrate the importance of repeating cross-validation when selecting an optimal model, as well as the importance of repeating nested cross-validation when assessing a prediction error.
LeDell, Erin; Petersen, Maya; van der Laan, Mark
In binary classification problems, the area under the ROC curve (AUC) is commonly used to evaluate the performance of a prediction model. Often, it is combined with cross-validation in order to assess how the results will generalize to an independent data set. In order to evaluate the quality of an estimate for cross-validated AUC, we obtain an estimate of its variance. For massive data sets, the process of generating a single performance estimate can be computationally expensive. Additionally, when using a complex prediction method, the process of cross-validating a predictive model on even a relatively small data set can still require a large amount of computation time. Thus, in many practical settings, the bootstrap is a computationally intractable approach to variance estimation. As an alternative to the bootstrap, we demonstrate a computationally efficient influence curve based approach to obtaining a variance estimate for cross-validated AUC.
Petersen, Maya; van der Laan, Mark
2015-01-01
In binary classification problems, the area under the ROC curve (AUC) is commonly used to evaluate the performance of a prediction model. Often, it is combined with cross-validation in order to assess how the results will generalize to an independent data set. In order to evaluate the quality of an estimate for cross-validated AUC, we obtain an estimate of its variance. For massive data sets, the process of generating a single performance estimate can be computationally expensive. Additionally, when using a complex prediction method, the process of cross-validating a predictive model on even a relatively small data set can still require a large amount of computation time. Thus, in many practical settings, the bootstrap is a computationally intractable approach to variance estimation. As an alternative to the bootstrap, we demonstrate a computationally efficient influence curve based approach to obtaining a variance estimate for cross-validated AUC. PMID:26279737
Multivariate Adaptive Regression Splines (Preprint)
1990-08-01
fold cross -validation would take about ten time as long, and MARS is not all that fast to begin with. Friedman has a number of examples showing...standardized mean squared error of prediction (MSEP), the generalized cross validation (GCV), and the number of selected terms (TERMS). In accordance with...and mi= 10 case were almost exclusively spurious cross product terms and terms involving the nuisance variables x6 through xlo. This large number of
Certification in Structural Health Monitoring Systems
2011-09-01
validation [3,8]. This may be accomplished by computing the sum of squares of pure error ( SSPE ) and its associated squared correlation [3,8]. To compute...these values, a cross- validation sample must be established. In general, if the SSPE is high, the model does not predict well on independent data...plethora of cross- validation methods, some of which are more useful for certain models than others [3,8]. When possible, a disclosure of the SSPE
Validation of COG10 and ENDFB6R7 on the Auk Workstation for General Application to Plutonium Systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Percher, Catherine G
2011-08-08
The COG 10 code package1 on the Auk workstation is now validated with the ENBFB6R7 neutron cross section library for general application to plutonium (Pu) systems by comparison of the calculated keffective to the expected keffective of several relevant experimental benchmarks. This validation is supplemental to the installation and verification of COG 10 on the Auk workstation2.
ERIC Educational Resources Information Center
van den Broek, Anneke; Golden, Charles J.; Loonstra, Ann; Ghinglia, Katheryne; Goldstein, Diane
1998-01-01
Indicated excellent cross-validations with correlation of 0.99 for past formulas (J. L. Woodard and B. N. Axelrod, 1995; B. N. Axelrod et al, 1996) for estimating the Wechsler Memory Scale- Revised General Memory and Delayed Recall Indexes. Over 85% of the estimated scores were within 10 points of actual scores. Age, education, diagnosis, and IQ…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Percher, Catherine G.
2011-08-08
The COG 10 code package1 on the Auk workstation is now validated with the ENBFB6R7 neutron cross section library for general application to highly enriched uranium (HEU) systems by comparison of the calculated keffective to the expected keffective of several relevant experimental benchmarks. This validation is supplemental to the installation and verification of COG 10 on the Auk workstation2.
Machine Learning Meta-analysis of Large Metagenomic Datasets: Tools and Biological Insights.
Pasolli, Edoardo; Truong, Duy Tin; Malik, Faizan; Waldron, Levi; Segata, Nicola
2016-07-01
Shotgun metagenomic analysis of the human associated microbiome provides a rich set of microbial features for prediction and biomarker discovery in the context of human diseases and health conditions. However, the use of such high-resolution microbial features presents new challenges, and validated computational tools for learning tasks are lacking. Moreover, classification rules have scarcely been validated in independent studies, posing questions about the generality and generalization of disease-predictive models across cohorts. In this paper, we comprehensively assess approaches to metagenomics-based prediction tasks and for quantitative assessment of the strength of potential microbiome-phenotype associations. We develop a computational framework for prediction tasks using quantitative microbiome profiles, including species-level relative abundances and presence of strain-specific markers. A comprehensive meta-analysis, with particular emphasis on generalization across cohorts, was performed in a collection of 2424 publicly available metagenomic samples from eight large-scale studies. Cross-validation revealed good disease-prediction capabilities, which were in general improved by feature selection and use of strain-specific markers instead of species-level taxonomic abundance. In cross-study analysis, models transferred between studies were in some cases less accurate than models tested by within-study cross-validation. Interestingly, the addition of healthy (control) samples from other studies to training sets improved disease prediction capabilities. Some microbial species (most notably Streptococcus anginosus) seem to characterize general dysbiotic states of the microbiome rather than connections with a specific disease. Our results in modelling features of the "healthy" microbiome can be considered a first step toward defining general microbial dysbiosis. The software framework, microbiome profiles, and metadata for thousands of samples are publicly available at http://segatalab.cibio.unitn.it/tools/metaml.
Cross-validation to select Bayesian hierarchical models in phylogenetics.
Duchêne, Sebastián; Duchêne, David A; Di Giallonardo, Francesca; Eden, John-Sebastian; Geoghegan, Jemma L; Holt, Kathryn E; Ho, Simon Y W; Holmes, Edward C
2016-05-26
Recent developments in Bayesian phylogenetic models have increased the range of inferences that can be drawn from molecular sequence data. Accordingly, model selection has become an important component of phylogenetic analysis. Methods of model selection generally consider the likelihood of the data under the model in question. In the context of Bayesian phylogenetics, the most common approach involves estimating the marginal likelihood, which is typically done by integrating the likelihood across model parameters, weighted by the prior. Although this method is accurate, it is sensitive to the presence of improper priors. We explored an alternative approach based on cross-validation that is widely used in evolutionary analysis. This involves comparing models according to their predictive performance. We analysed simulated data and a range of viral and bacterial data sets using a cross-validation approach to compare a variety of molecular clock and demographic models. Our results show that cross-validation can be effective in distinguishing between strict- and relaxed-clock models and in identifying demographic models that allow growth in population size over time. In most of our empirical data analyses, the model selected using cross-validation was able to match that selected using marginal-likelihood estimation. The accuracy of cross-validation appears to improve with longer sequence data, particularly when distinguishing between relaxed-clock models. Cross-validation is a useful method for Bayesian phylogenetic model selection. This method can be readily implemented even when considering complex models where selecting an appropriate prior for all parameters may be difficult.
NASA Astrophysics Data System (ADS)
Kitterød, Nils-Otto
2017-08-01
Unconsolidated sediment cover thickness (D) above bedrock was estimated by using a publicly available well database from Norway, GRANADA. General challenges associated with such databases typically involve clustering and bias. However, if information about the horizontal distance to the nearest bedrock outcrop (L) is included, does the spatial estimation of D improve? This idea was tested by comparing two cross-validation results: ordinary kriging (OK) where L was disregarded; and co-kriging (CK) where cross-covariance between D and L was included. The analysis showed only minor differences between OK and CK with respect to differences between estimation and true values. However, the CK results gave in general less estimation variance compared to the OK results. All observations were declustered and transformed to standard normal probability density functions before estimation and back-transformed for the cross-validation analysis. The semivariogram analysis gave correlation lengths for D and L of approx. 10 and 6 km. These correlations reduce the estimation variance in the cross-validation analysis because more than 50 % of the data material had two or more observations within a radius of 5 km. The small-scale variance of D, however, was about 50 % of the total variance, which gave an accuracy of less than 60 % for most of the cross-validation cases. Despite the noisy character of the observations, the analysis demonstrated that L can be used as secondary information to reduce the estimation variance of D.
Cross Validation of Selection of Variables in Multiple Regression.
1979-12-01
55 vii CROSS VALIDATION OF SELECTION OF VARIABLES IN MULTIPLE REGRESSION I Introduction Background Long term DoD planning gcals...028545024 .31109000 BF * SS - .008700618 .0471961 Constant - .70977903 85.146786 55 had adequate predictive capabilities; the other two models (the...71ZCO F111D Control 54 73EGO FlIID Computer, General Purpose 55 73EPO FII1D Converter-Multiplexer 56 73HAO flllD Stabilizer Platform 57 73HCO F1ID
Benchmarking protein classification algorithms via supervised cross-validation.
Kertész-Farkas, Attila; Dhir, Somdutta; Sonego, Paolo; Pacurar, Mircea; Netoteia, Sergiu; Nijveen, Harm; Kuzniar, Arnold; Leunissen, Jack A M; Kocsor, András; Pongor, Sándor
2008-04-24
Development and testing of protein classification algorithms are hampered by the fact that the protein universe is characterized by groups vastly different in the number of members, in average protein size, similarity within group, etc. Datasets based on traditional cross-validation (k-fold, leave-one-out, etc.) may not give reliable estimates on how an algorithm will generalize to novel, distantly related subtypes of the known protein classes. Supervised cross-validation, i.e., selection of test and train sets according to the known subtypes within a database has been successfully used earlier in conjunction with the SCOP database. Our goal was to extend this principle to other databases and to design standardized benchmark datasets for protein classification. Hierarchical classification trees of protein categories provide a simple and general framework for designing supervised cross-validation strategies for protein classification. Benchmark datasets can be designed at various levels of the concept hierarchy using a simple graph-theoretic distance. A combination of supervised and random sampling was selected to construct reduced size model datasets, suitable for algorithm comparison. Over 3000 new classification tasks were added to our recently established protein classification benchmark collection that currently includes protein sequence (including protein domains and entire proteins), protein structure and reading frame DNA sequence data. We carried out an extensive evaluation based on various machine-learning algorithms such as nearest neighbor, support vector machines, artificial neural networks, random forests and logistic regression, used in conjunction with comparison algorithms, BLAST, Smith-Waterman, Needleman-Wunsch, as well as 3D comparison methods DALI and PRIDE. The resulting datasets provide lower, and in our opinion more realistic estimates of the classifier performance than do random cross-validation schemes. A combination of supervised and random sampling was used to construct model datasets, suitable for algorithm comparison.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mbah, Chamberlain, E-mail: chamberlain.mbah@ugent.be; Department of Mathematical Modeling, Statistics, and Bioinformatics, Faculty of Bioscience Engineering, Ghent University, Ghent; Thierens, Hubert
Purpose: To identify the main causes underlying the failure of prediction models for radiation therapy toxicity to replicate. Methods and Materials: Data were used from two German cohorts, Individual Radiation Sensitivity (ISE) (n=418) and Mammary Carcinoma Risk Factor Investigation (MARIE) (n=409), of breast cancer patients with similar characteristics and radiation therapy treatments. The toxicity endpoint chosen was telangiectasia. The LASSO (least absolute shrinkage and selection operator) logistic regression method was used to build a predictive model for a dichotomized endpoint (Radiation Therapy Oncology Group/European Organization for the Research and Treatment of Cancer score 0, 1, or ≥2). Internal areas undermore » the receiver operating characteristic curve (inAUCs) were calculated by a naïve approach whereby the training data (ISE) were also used for calculating the AUC. Cross-validation was also applied to calculate the AUC within the same cohort, a second type of inAUC. Internal AUCs from cross-validation were calculated within ISE and MARIE separately. Models trained on one dataset (ISE) were applied to a test dataset (MARIE) and AUCs calculated (exAUCs). Results: Internal AUCs from the naïve approach were generally larger than inAUCs from cross-validation owing to overfitting the training data. Internal AUCs from cross-validation were also generally larger than the exAUCs, reflecting heterogeneity in the predictors between cohorts. The best models with largest inAUCs from cross-validation within both cohorts had a number of common predictors: hypertension, normalized total boost, and presence of estrogen receptors. Surprisingly, the effect (coefficient in the prediction model) of hypertension on telangiectasia incidence was positive in ISE and negative in MARIE. Other predictors were also not common between the 2 cohorts, illustrating that overcoming overfitting does not solve the problem of replication failure of prediction models completely. Conclusions: Overfitting and cohort heterogeneity are the 2 main causes of replication failure of prediction models across cohorts. Cross-validation and similar techniques (eg, bootstrapping) cope with overfitting, but the development of validated predictive models for radiation therapy toxicity requires strategies that deal with cohort heterogeneity.« less
Nguyen, N; Milanfar, P; Golub, G
2001-01-01
In many image restoration/resolution enhancement applications, the blurring process, i.e., point spread function (PSF) of the imaging system, is not known or is known only to within a set of parameters. We estimate these PSF parameters for this ill-posed class of inverse problem from raw data, along with the regularization parameters required to stabilize the solution, using the generalized cross-validation method (GCV). We propose efficient approximation techniques based on the Lanczos algorithm and Gauss quadrature theory, reducing the computational complexity of the GCV. Data-driven PSF and regularization parameter estimation experiments with synthetic and real image sequences are presented to demonstrate the effectiveness and robustness of our method.
Analysis of general power counting rules in effective field theory
Gavela, Belen; Jenkins, Elizabeth E.; Manohar, Aneesh V.; ...
2016-09-02
We derive the general counting rules for a quantum effective field theory (EFT) in d dimensions. The rules are valid for strongly and weakly coupled theories, and they predict that all kinetic energy terms are canonically normalized. They determine the energy dependence of scattering cross sections in the range of validity of the EFT expansion. We show that the size of the cross sections is controlled by the Λ power counting of EFT, not by chiral counting, even for chiral perturbation theory (χPT). The relation between Λ and f is generalized to d dimensions. We show that the naive dimensionalmore » analysis 4π counting is related to ℏ counting. The EFT counting rules are applied to χPT, low-energy weak interactions, Standard Model EFT and the non-trivial case of Higgs EFT.« less
ERIC Educational Resources Information Center
Boonstra, Anne M.; Reneman, Michiel F.; Stewart, Roy E.; Balk, Gerlof A.
2012-01-01
The aim of this study was to determine the reliability and discriminant validity of the Dutch version of the life satisfaction questionnaire (Lisat-9 DV) to assess patients with an acquired brain injury. The reliability study used a test-retest design, and the validity study used a cross-sectional design. The setting was the general rehabilitation…
Middleton, James W; Tran, Yvonne; Lo, Charles; Craig, Ashley
2016-12-01
To improve the clinical utility of the Moorong Self-Efficacy Scale (MSES) by reexamining its factor structure and comparing its performance against a measure of general self-efficacy in persons with spinal cord injury (SCI). Cross-sectional survey design. Community. Adults with SCI (N=161; 118 men and 43 women) recruited from Australia (n=82) and the United States (n=79), including 86 with paraplegia and 75 with tetraplegia. None. Confirmatory factor analysis deriving fit indices on reported 1-, 2-, and 3-factor structures for the MSES. Exploratory factor analysis of MSES using principal component analysis with promax oblique rotation and structure validation, with correlations and multiple regression using cross-sectional data from the Sherer General Self-Efficacy Scale and Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). The MSES was confirmed to have a 3-factor structure, explaining 61% of variance. Two of the factors, labeled social function self-efficacy and personal function self-efficacy, were SCI condition-specific, whereas the other factor (accounting for 9.7% of variance) represented general self-efficacy, correlating most strongly with the Sherer General Self-Efficacy Scale. Correlations and multiple regression analyses between MSES factors, Sherer General Self-Efficacy Scale total score, SF-36 Physical and Mental Component Summary scores, and SF-36 domain scores support validity of this MSES factor structure. No significant cross-cultural differences existed between Australia and the United States in total MSES or factor scores. The findings support a 3-factor structure encompassing general and SCI domain-specific self-efficacy beliefs and better position the MSES to assist SCI rehabilitation assessment, planning, and research. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Alternative methods to evaluate trial level surrogacy.
Abrahantes, Josè Cortiñas; Shkedy, Ziv; Molenberghs, Geert
2008-01-01
The evaluation and validation of surrogate endpoints have been extensively studied in the last decade. Prentice [1] and Freedman, Graubard and Schatzkin [2] laid the foundations for the evaluation of surrogate endpoints in randomized clinical trials. Later, Buyse et al. [5] proposed a meta-analytic methodology, producing different methods for different settings, which was further studied by Alonso and Molenberghs [9], in their unifying approach based on information theory. In this article, we focus our attention on the trial-level surrogacy and propose alternative procedures to evaluate such surrogacy measure, which do not pre-specify the type of association. A promising correction based on cross-validation is investigated. As well as the construction of confidence intervals for this measure. In order to avoid making assumption about the type of relationship between the treatment effects and its distribution, a collection of alternative methods, based on regression trees, bagging, random forests, and support vector machines, combined with bootstrap-based confidence interval and, should one wish, in conjunction with a cross-validation based correction, will be proposed and applied. We apply the various strategies to data from three clinical studies: in opthalmology, in advanced colorectal cancer, and in schizophrenia. The results obtained for the three case studies are compared; they indicate that using random forest or bagging models produces larger estimated values for the surrogacy measure, which are in general stabler and the confidence interval narrower than linear regression and support vector regression. For the advanced colorectal cancer studies, we even found the trial-level surrogacy is considerably different from what has been reported. In general the alternative methods are more computationally demanding, and specially the calculation of the confidence intervals, require more computational time that the delta-method counterpart. First, more flexible modeling techniques can be used, allowing for other type of association. Second, when no cross-validation-based correction is applied, overly optimistic trial-level surrogacy estimates will be found, thus cross-validation is highly recommendable. Third, the use of the delta method to calculate confidence intervals is not recommendable since it makes assumptions valid only in very large samples. It may also produce range-violating limits. We therefore recommend alternatives: bootstrap methods in general. Also, the information-theoretic approach produces comparable results with the bagging and random forest approaches, when cross-validation correction is applied. It is also important to observe that, even for the case in which the linear model might be a good option too, bagging methods perform well too, and their confidence intervals were more narrow.
Methodology and issues of integral experiments selection for nuclear data validation
NASA Astrophysics Data System (ADS)
Tatiana, Ivanova; Ivanov, Evgeny; Hill, Ian
2017-09-01
Nuclear data validation involves a large suite of Integral Experiments (IEs) for criticality, reactor physics and dosimetry applications. [1] Often benchmarks are taken from international Handbooks. [2, 3] Depending on the application, IEs have different degrees of usefulness in validation, and usually the use of a single benchmark is not advised; indeed, it may lead to erroneous interpretation and results. [1] This work aims at quantifying the importance of benchmarks used in application dependent cross section validation. The approach is based on well-known General Linear Least Squared Method (GLLSM) extended to establish biases and uncertainties for given cross sections (within a given energy interval). The statistical treatment results in a vector of weighting factors for the integral benchmarks. These factors characterize the value added by a benchmark for nuclear data validation for the given application. The methodology is illustrated by one example, selecting benchmarks for 239Pu cross section validation. The studies were performed in the framework of Subgroup 39 (Methods and approaches to provide feedback from nuclear and covariance data adjustment for improvement of nuclear data files) established at the Working Party on International Nuclear Data Evaluation Cooperation (WPEC) of the Nuclear Science Committee under the Nuclear Energy Agency (NEA/OECD).
Technical Analysis of Scores on the "Self-Efficacy Self-Report Scale"
ERIC Educational Resources Information Center
Erford, Bradley T.; Schein, Hallie; Duncan, Kelly
2011-01-01
The purpose of this study was to provide preliminary analysis of reliability and validity of scores on the "Self-Efficacy Self-Report Scale", which was designed to assess general self-efficacy in students aged 10 to 17 years. Confirmatory factor analysis on cross-validated samples was conducted revealing a marginal fit of the data to the…
Coping with Health Problems: Developing a Reliable and Valid Multidimensional Measure.
ERIC Educational Resources Information Center
Endler, Norman S.; Parker, James D. A.; Summerfeldt, Laura J.
1998-01-01
A self-report measure, the Coping with Health Injuries and Problems Scale (CHIP), was developed to identify basic coping dimensions for responding to health problems. The CHIP factor structure, established with samples of 532 adults and 598 adults in Canada, is cross-validated with 390 general medical patients and 286 chronic back pain patients.…
Olivera, André Rodrigues; Roesler, Valter; Iochpe, Cirano; Schmidt, Maria Inês; Vigo, Álvaro; Barreto, Sandhi Maria; Duncan, Bruce Bartholow
2017-01-01
Type 2 diabetes is a chronic disease associated with a wide range of serious health complications that have a major impact on overall health. The aims here were to develop and validate predictive models for detecting undiagnosed diabetes using data from the Longitudinal Study of Adult Health (ELSA-Brasil) and to compare the performance of different machine-learning algorithms in this task. Comparison of machine-learning algorithms to develop predictive models using data from ELSA-Brasil. After selecting a subset of 27 candidate variables from the literature, models were built and validated in four sequential steps: (i) parameter tuning with tenfold cross-validation, repeated three times; (ii) automatic variable selection using forward selection, a wrapper strategy with four different machine-learning algorithms and tenfold cross-validation (repeated three times), to evaluate each subset of variables; (iii) error estimation of model parameters with tenfold cross-validation, repeated ten times; and (iv) generalization testing on an independent dataset. The models were created with the following machine-learning algorithms: logistic regression, artificial neural network, naïve Bayes, K-nearest neighbor and random forest. The best models were created using artificial neural networks and logistic regression. -These achieved mean areas under the curve of, respectively, 75.24% and 74.98% in the error estimation step and 74.17% and 74.41% in the generalization testing step. Most of the predictive models produced similar results, and demonstrated the feasibility of identifying individuals with highest probability of having undiagnosed diabetes, through easily-obtained clinical data.
ERIC Educational Resources Information Center
Manti, Eirini; Scholte, Evert M.; Van Berckelaer-Onnes, Ina A.
2009-01-01
The scope of the present study was first to evaluate the cross-cultural reliability and validity of the Social Emotional Questionnaire (SEQ) and second to estimate and compare the prevalence rates of childhood developmental and psychiatric disorders in the general population of young children in the Netherlands and Greece. To this end, the…
The Cross-Cultural Loss Scale: development and psychometric evaluation.
Wang, Kenneth T; Wei, Meifen; Zhao, Ran; Chuang, Chih-Chun; Li, Feihan
2015-03-01
The Cross-Cultural Loss Scale (CCLS), a measure of loss associated with crossing national boundaries, was developed across 2 samples of international students. With Sample 1 (N = 262), exploratory factor analyses were used to select the 14 CCLS items and to determine 3 factors: Belonging-Competency (α = .87), National Privileges (α = .68), and Access to Home Familiarity (α = .72). With Sample 2, confirmatory factor analyses (N = 256) cross-validated the 3-factor oblique model as well as a bifactor model. Cronbach alphas of CCLS subscale scores in Sample 2 ranged from .73 to .87. The validity of the CCLS scores was supported by its associations with related variables in the expected directions. Perceived cross-cultural losses were positively associated with negative affect, migration grief and loss, and discrimination and were negatively associated with life satisfaction, positive affect, general self-efficacy, and social connection with mainstream society. Moreover, the CCLS total and 2 subscale scores added significant incremental variance in predicting subjective well-being over and above related constructs. The results indicated measurement invariance and validity equivalency for the CCLS scores between men and women. The overall results from these 2 samples support CCLS as a psychometrically strong measure. 2015 APA, all rights reserved
Evaluation and comparison of predictive individual-level general surrogates.
Gabriel, Erin E; Sachs, Michael C; Halloran, M Elizabeth
2018-07-01
An intermediate response measure that accurately predicts efficacy in a new setting at the individual level could be used both for prediction and personalized medical decisions. In this article, we define a predictive individual-level general surrogate (PIGS), which is an individual-level intermediate response that can be used to accurately predict individual efficacy in a new setting. While methods for evaluating trial-level general surrogates, which are predictors of trial-level efficacy, have been developed previously, few, if any, methods have been developed to evaluate individual-level general surrogates, and no methods have formalized the use of cross-validation to quantify the expected prediction error. Our proposed method uses existing methods of individual-level surrogate evaluation within a given clinical trial setting in combination with cross-validation over a set of clinical trials to evaluate surrogate quality and to estimate the absolute prediction error that is expected in a new trial setting when using a PIGS. Simulations show that our method performs well across a variety of scenarios. We use our method to evaluate and to compare candidate individual-level general surrogates over a set of multi-national trials of a pentavalent rotavirus vaccine.
Tilov, Boris; Dimitrova, Donka; Stoykova, Maria; Tornjova, Bianka; Foreva, Gergana; Stoyanov, Drozdstoj
2012-12-01
Health-care professions have long been considered prone to work-related stress, yet recent research in Bulgaria indicates alarmingly high levels of burnout. Cloninger's inventory is used to analyse and evaluate correlation between personality characteristics and degree of burnout syndrome manifestation among the risk categories of health-care professionals. The primary goal of this study was to test the conceptual validity and cross-cultural applicability of the revised TCI (TCI-R), developed in the United States, in a culturally, socially and economically diverse setting. Linguistic validation, test-retest studies, statistical and expert analyses were performed to assess cross-cultural applicability of the revised Cloninger's temperament and character inventory in Bulgarian, its reliability and internal consistency and construct validity. The overall internal consistency of TCI-R and its scales as well as the interscale and test-retest correlations prove that the translated version of the questionnaire is acceptable and cross-culturally applicable for the purposes of studying organizational stress and burnout risk in health-care professionals. In general the cross-cultural adaptation process, even if carried out in a rigorous way, does not always lead to the best target version and suggests it would be useful to develop new scales specific to each culture and, at the same time, to think about the trans-cultural adaptation. © 2012 Blackwell Publishing Ltd.
Validation of Cross Sections for Monte Carlo Simulation of the Photoelectric Effect
NASA Astrophysics Data System (ADS)
Han, Min Cheol; Kim, Han Sung; Pia, Maria Grazia; Basaglia, Tullio; Batič, Matej; Hoff, Gabriela; Kim, Chan Hyeong; Saracco, Paolo
2016-04-01
Several total and partial photoionization cross section calculations, based on both theoretical and empirical approaches, are quantitatively evaluated with statistical analyses using a large collection of experimental data retrieved from the literature to identify the state of the art for modeling the photoelectric effect in Monte Carlo particle transport. Some of the examined cross section models are available in general purpose Monte Carlo systems, while others have been implemented and subjected to validation tests for the first time to estimate whether they could improve the accuracy of particle transport codes. The validation process identifies Scofield's 1973 non-relativistic calculations, tabulated in the Evaluated Photon Data Library (EPDL), as the one best reproducing experimental measurements of total cross sections. Specialized total cross section models, some of which derive from more recent calculations, do not provide significant improvements. Scofield's non-relativistic calculations are not surpassed regarding the compatibility with experiment of K and L shell photoionization cross sections either, although in a few test cases Ebel's parameterization produces more accurate results close to absorption edges. Modifications to Biggs and Lighthill's parameterization implemented in Geant4 significantly reduce the accuracy of total cross sections at low energies with respect to its original formulation. The scarcity of suitable experimental data hinders a similar extensive analysis for the simulation of the photoelectron angular distribution, which is limited to a qualitative appraisal.
Validation of Yoon's Critical Thinking Disposition Instrument.
Shin, Hyunsook; Park, Chang Gi; Kim, Hyojin
2015-12-01
The lack of reliable and valid evaluation tools targeting Korean nursing students' critical thinking (CT) abilities has been reported as one of the barriers to instructing and evaluating students in undergraduate programs. Yoon's Critical Thinking Disposition (YCTD) instrument was developed for Korean nursing students, but few studies have assessed its validity. This study aimed to validate the YCTD. Specifically, the YCTD was assessed to identify its cross-sectional and longitudinal measurement invariance. This was a validation study in which a cross-sectional and longitudinal (prenursing and postnursing practicum) survey was used to validate the YCTD using 345 nursing students at three universities in Seoul, Korea. The participants' CT abilities were assessed using the YCTD before and after completing an established pediatric nursing practicum. The validity of the YCTD was estimated and then group invariance test using multigroup confirmatory factor analysis was performed to confirm the measurement compatibility of multigroups. A test of the seven-factor model showed that the YCTD demonstrated good construct validity. Multigroup confirmatory factor analysis findings for the measurement invariance suggested that this model structure demonstrated strong invariance between groups (i.e., configural, factor loading, and intercept combined) but weak invariance within a group (i.e., configural and factor loading combined). In general, traditional methods for assessing instrument validity have been less than thorough. In this study, multigroup confirmatory factor analysis using cross-sectional and longitudinal measurement data allowed validation of the YCTD. This study concluded that the YCTD can be used for evaluating Korean nursing students' CT abilities. Copyright © 2015. Published by Elsevier B.V.
Rational selection of training and test sets for the development of validated QSAR models
NASA Astrophysics Data System (ADS)
Golbraikh, Alexander; Shen, Min; Xiao, Zhiyan; Xiao, Yun-De; Lee, Kuo-Hsiung; Tropsha, Alexander
2003-02-01
Quantitative Structure-Activity Relationship (QSAR) models are used increasingly to screen chemical databases and/or virtual chemical libraries for potentially bioactive molecules. These developments emphasize the importance of rigorous model validation to ensure that the models have acceptable predictive power. Using k nearest neighbors ( kNN) variable selection QSAR method for the analysis of several datasets, we have demonstrated recently that the widely accepted leave-one-out (LOO) cross-validated R2 (q2) is an inadequate characteristic to assess the predictive ability of the models [Golbraikh, A., Tropsha, A. Beware of q2! J. Mol. Graphics Mod. 20, 269-276, (2002)]. Herein, we provide additional evidence that there exists no correlation between the values of q 2 for the training set and accuracy of prediction ( R 2) for the test set and argue that this observation is a general property of any QSAR model developed with LOO cross-validation. We suggest that external validation using rationally selected training and test sets provides a means to establish a reliable QSAR model. We propose several approaches to the division of experimental datasets into training and test sets and apply them in QSAR studies of 48 functionalized amino acid anticonvulsants and a series of 157 epipodophyllotoxin derivatives with antitumor activity. We formulate a set of general criteria for the evaluation of predictive power of QSAR models.
Heo, K H; Squires, J; Yovanoff, P
2008-03-01
Accurate and efficient developmental screening measures are critical for early identification of developmental problems; however, few reliable and valid tests are available in Korea as well as other countries outside the USA. The Ages and Stages Questionnaires (ASQ) was chosen for study with young children in Korea. The ASQ was translated into Korean and necessary cross-cultural adaptations were made. The translated version was then distributed and completed by 3220 parents of young children between the ages of 4 months and 5 years. Reliability was studied including domain correlations, internal consistency, and performance of identification cut-off scores for the Korean population. Rasch analyses including tests of Differential Item Functioning, contrasting Korean and US samples were also performed. In general, internal consistency of the Korean ASQ was high, with overall correlations 0.75 for communication, 0.85 for gross motor, 0.74 for fine motor, 0.72 for problem solving, and 0.65 for personal-social. Validity, including concurrent validity, also had strong evidence. Mean scores of children on the Korean translation of the ASQ and the US normative sample were generally similar. Rasch analyses indicated the majority of items functioned similarly across the Korean sample. In general, the ASQ was translated with cultural appropriateness in mind and functioned as a valid and reliable parent-completed screening test to assist in early identification of young children with developmental delays. Further research is needed to confirm these results with a larger and more diverse Korean sample.
patches to cycle from sink to source status and back.Objective: Through a combination of field studies and state-of-the-art quantitative models, we...landscapes with dynamic changes in habitat quality due to management. We also validated our general approach by comparing patterns in our focal species to general, cross-taxa, patterns.
Lee, Siau Pheng; Ong, Clarissa; Vaingankar, Janhavi Ajit; Chong, Siow Ann; Subramaniam, Mythily
2017-05-01
Previous findings on the diagnostic validity and reliability of generalized anxiety disorder (GAD)-associated symptom criteria suggest need for further evaluation. The current study examined convergent validity and specificity of GAD-associated symptoms in a representative Singapore community sample. The Singapore of Mental Health Study a cross-sectional epidemiological survey conducted among 6166 Singapore residents aged 18 and older. The Composite International Diagnostic Interview version 3.0 was used to diagnose mental disorders. Associated symptoms in the GAD criteria and autonomic hyperactivity symptoms showed convergent validity with a GAD diagnosis. However, associated symptoms of GAD were also linked to major depressive disorder (MDD), bipolar disorder, and obsessive-compulsive disorder, suggesting lack of adequate specificity. The inability of the diagnostic criteria to differentiate GAD from symptoms of other conditions highlights the need to better define its associated symptoms criteria. The relationship of overlapping symptoms between GAD and MDD is also discussed.
A General Method for Targeted Quantitative Cross-Linking Mass Spectrometry.
Chavez, Juan D; Eng, Jimmy K; Schweppe, Devin K; Cilia, Michelle; Rivera, Keith; Zhong, Xuefei; Wu, Xia; Allen, Terrence; Khurgel, Moshe; Kumar, Akhilesh; Lampropoulos, Athanasios; Larsson, Mårten; Maity, Shuvadeep; Morozov, Yaroslav; Pathmasiri, Wimal; Perez-Neut, Mathew; Pineyro-Ruiz, Coriness; Polina, Elizabeth; Post, Stephanie; Rider, Mark; Tokmina-Roszyk, Dorota; Tyson, Katherine; Vieira Parrine Sant'Ana, Debora; Bruce, James E
2016-01-01
Chemical cross-linking mass spectrometry (XL-MS) provides protein structural information by identifying covalently linked proximal amino acid residues on protein surfaces. The information gained by this technique is complementary to other structural biology methods such as x-ray crystallography, NMR and cryo-electron microscopy[1]. The extension of traditional quantitative proteomics methods with chemical cross-linking can provide information on the structural dynamics of protein structures and protein complexes. The identification and quantitation of cross-linked peptides remains challenging for the general community, requiring specialized expertise ultimately limiting more widespread adoption of the technique. We describe a general method for targeted quantitative mass spectrometric analysis of cross-linked peptide pairs. We report the adaptation of the widely used, open source software package Skyline, for the analysis of quantitative XL-MS data as a means for data analysis and sharing of methods. We demonstrate the utility and robustness of the method with a cross-laboratory study and present data that is supported by and validates previously published data on quantified cross-linked peptide pairs. This advance provides an easy to use resource so that any lab with access to a LC-MS system capable of performing targeted quantitative analysis can quickly and accurately measure dynamic changes in protein structure and protein interactions.
Pechorro, Pedro; Ribeiro da Silva, Diana; Andershed, Henrik; Rijo, Daniel; Abrunhosa Gonçalves, Rui
2016-01-01
The aim of the present study was to examine the psychometric properties of the Youth Psychopathic Traits Inventory (YPI) among a mixed-gender sample of 782 Portuguese youth (M = 15.87 years; SD = 1.72), in a school context. Confirmatory factor analysis revealed the expected three-factor first-order structure. Cross-gender measurement invariance and cross-sample measurement invariance using a forensic sample of institutionalized males were also confirmed. The Portuguese version of the YPI demonstrated generally adequate psychometric properties of internal consistency, mean inter-item correlation, convergent validity, discriminant validity, and criterion-related validity of statistically significant associations with conduct disorder symptoms, alcohol abuse, drug use, and unprotected sex. In terms of known-groups validity, males scored higher than females, and males from the school sample scored lower than institutionalized males. The use of the YPI among the Portuguese male and female youth population is psychometrically justified, and it can be a useful measure to identify adolescents with high levels of psychopathic traits. PMID:27571095
Mindful attention and awareness: relationships with psychopathology and emotion regulation.
Gregório, Sónia; Pinto-Gouveia, José
2013-01-01
The growing interest in mindfulness from the scientific community has originated several self-report measures of this psychological construct. The Mindful Attention and Awareness Scale (MAAS) is a self-report measure of mindfulness at a trait-level. This paper aims at exploring MAAS psychometric characteristics and validating it for the Portuguese population. The first two studies replicate some of the original author's statistical procedures in two different samples from the Portuguese general community population, in particular confirmatory factor analyses. Results from both analyses confirmed the scale single-factor structure and indicated a very good reliability. Moreover, cross-validation statistics showed that this single-factor structure is valid for different respondents from the general community population. In the third study the Portuguese version of the MAAS was found to have good convergent and discriminant validities. Overall the findings support the psychometric validity of the Portuguese version of MAAS and suggest this is a reliable self-report measure of trait-mindfulness, a central construct in Clinical Psychology research and intervention fields.
Selection of regularization parameter in total variation image restoration.
Liao, Haiyong; Li, Fang; Ng, Michael K
2009-11-01
We consider and study total variation (TV) image restoration. In the literature there are several regularization parameter selection methods for Tikhonov regularization problems (e.g., the discrepancy principle and the generalized cross-validation method). However, to our knowledge, these selection methods have not been applied to TV regularization problems. The main aim of this paper is to develop a fast TV image restoration method with an automatic selection of the regularization parameter scheme to restore blurred and noisy images. The method exploits the generalized cross-validation (GCV) technique to determine inexpensively how much regularization to use in each restoration step. By updating the regularization parameter in each iteration, the restored image can be obtained. Our experimental results for testing different kinds of noise show that the visual quality and SNRs of images restored by the proposed method is promising. We also demonstrate that the method is efficient, as it can restore images of size 256 x 256 in approximately 20 s in the MATLAB computing environment.
Validation of the Spanish version of the Index of Spouse Abuse.
Plazaola-Castaño, Juncal; Ruiz-Pérez, Isabel; Escribà-Agüir, Vicenta; Jiménez-Martín, Juan Manuel; Hernández-Torres, Elisa
2009-04-01
Partner violence against women is a major public health problem. Although there are currently a number of validated screening and diagnostic tools that can be used to evaluate this type of violence, such tools are not available in Spain. The aim of this study is to analyze the validity and reliability of the Spanish version of the Index of Spouse Abuse (ISA). A cross-sectional study was carried out in 2005 in two health centers in Granada, Spain, in 390 women between 18 and 70 years old. Analyses of the factorial structure, internal consistency, test-retest reliability, and construct validity were conducted. Cutoff points for each subscale were also defined. For the construct validity analysis, the SF-36 perceived general health dimension, the Rosenberg Self-Esteem Scale and the Goldberg 12-item General Health Questionnaire were included. The psychometric analysis shows that the instrument has good internal consistency, reproducibility, and construct validity. The scale is useful for the analysis of partner violence against women in both a research setting and a healthcare setting.
Hall, Brian J.; Puffer, Eve; Murray, Laura K.; Ismael, Abdulkadir; Bass, Judith K.; Sim, Amanda; Bolton, Paul A.
2014-01-01
Assessing mental health problems cross-culturally for children exposed to war and violence presents a number of unique challenges. One of the most important issues is the lack of validated symptom measures to assess these problems. The present study sought to evaluate the psychometric properties of two measures to assess mental health problems: the Achenbach Youth Self-Report and the Child Posttraumatic Stress Disorder Symptom Scale. We conducted a validity study in three refugee camps in Eastern Ethiopia in the outskirts of Jijiga, the capital of the Somali region. A total of 147 child and caregiver pairs were assessed, and scores obtained were submitted to rigorous psychometric evaluation. Excellent internal consistency reliability was obtained for symptom measures for children and their caregivers. Validation of study instruments based on local case definitions was obtained for the caregivers but not consistently for the children. Sensitivity and specificity of study measures were generally low, indicating that these scales would not perform adequately as screening instruments. Combined test-retest and inter-rater reliability was low for all scales. This study illustrates the need for validation and testing of existing measures cross-culturally. Methodological implications for future cross-cultural research studies in low- and middle-income countries are discussed. PMID:24955147
NASA Astrophysics Data System (ADS)
Samala, Ravi K.; Chan, Heang-Ping; Hadjiiski, Lubomir; Helvie, Mark A.; Richter, Caleb; Cha, Kenny
2018-02-01
We propose a cross-domain, multi-task transfer learning framework to transfer knowledge learned from non-medical images by a deep convolutional neural network (DCNN) to medical image recognition task while improving the generalization by multi-task learning of auxiliary tasks. A first stage cross-domain transfer learning was initiated from ImageNet trained DCNN to mammography trained DCNN. 19,632 regions-of-interest (ROI) from 2,454 mass lesions were collected from two imaging modalities: digitized-screen film mammography (SFM) and full-field digital mammography (DM), and split into training and test sets. In the multi-task transfer learning, the DCNN learned the mass classification task simultaneously from the training set of SFM and DM. The best transfer network for mammography was selected from three transfer networks with different number of convolutional layers frozen. The performance of single-task and multitask transfer learning on an independent SFM test set in terms of the area under the receiver operating characteristic curve (AUC) was 0.78+/-0.02 and 0.82+/-0.02, respectively. In the second stage cross-domain transfer learning, a set of 12,680 ROIs from 317 mass lesions on DBT were split into validation and independent test sets. We first studied the data requirements for the first stage mammography trained DCNN by varying the mammography training data from 1% to 100% and evaluated its learning on the DBT validation set in inference mode. We found that the entire available mammography set provided the best generalization. The DBT validation set was then used to train only the last four fully connected layers, resulting in an AUC of 0.90+/-0.04 on the independent DBT test set.
Al-Heeti, Khalaf N M; Hamid, Abdalla A R M; Alghorani, Mohammad A
2012-08-01
The purpose of this study was to examine the psychometric properties of the adapted Irrational Beliefs Inventory (IBI-34) and thus begin the process of assessing its adequacy for use in an Arab culture. The scale was translated and then administered to two samples of undergraduate students from the United Arab Emirates University. Data from 384 students were used in the main analysis, and data from 251 students were used for cross-validation. Principal components analysis (PCA) with varimax rotation followed by PCA with oblimin rotation yielded the same five components in both the main sample and the validation sample, thus consistent with the original Dutch study. Only 34 of the original 50 items were adequate to represent the five constructs. Cronbach's alpha coefficient for the overall scale was .76 and for the subscales ranged between .71 and .76, except for the Rigidity subscale, which was .54. The adapted IBI-34 correlated significantly and negatively with the General Health Questionnaire and Beck Depression Inventory, providing support for concurrent validity. Due to the non-significant differences between male and female participants on the total score of the IBI-34, the scale can be used for both sexes by summing across all items to give a total score that can be used as a general indicator of the irrational thinking.
The Fuge Tube Diode Array Spectrophotometer
ERIC Educational Resources Information Center
Arneson, B. T.; Long, S. R.; Stewart, K. K.; Lagowski, J. J.
2008-01-01
We present the details for adapting a diode array UV-vis spectrophotometer to incorporate the use of polypropylene microcentrifuge tubes--fuge tubes--as cuvettes. Optical data are presented validating that the polyethylene fuge tubes are equivalent to the standard square cross section polystyrene or glass cuvettes generally used in…
1989-09-01
separate network architetures would otherwise have to be performed for each 5 of the nearly 70 cross-validation regressions. Fixing the composition...presentation. The generalized delta rule says the weight of each connection should be changed by an amount proportional to the product of the processing
The Gold Standard for determining freely dissolved concentrations (Cfree) of hydrophobic organic compounds in sediment interstitial water would be in situ deployment combined with equilibrium sampling, which is generally difficult to achieve. In the present study, ex situ equilib...
Model Selection Indices for Polytomous Items
ERIC Educational Resources Information Center
Kang, Taehoon; Cohen, Allan S.; Sung, Hyun-Jung
2009-01-01
This study examines the utility of four indices for use in model selection with nested and nonnested polytomous item response theory (IRT) models: a cross-validation index and three information-based indices. Four commonly used polytomous IRT models are considered: the graded response model, the generalized partial credit model, the partial credit…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Curchod, Basile F. E.; Martínez, Todd J., E-mail: toddjmartinez@gmail.com; SLAC National Accelerator Laboratory, Menlo Park, California 94025
2016-03-14
Full multiple spawning is a formally exact method to describe the excited-state dynamics of molecular systems beyond the Born-Oppenheimer approximation. However, it has been limited until now to the description of radiationless transitions taking place between electronic states with the same spin multiplicity. This Communication presents a generalization of the full and ab initio multiple spawning methods to both internal conversion (mediated by nonadiabatic coupling terms) and intersystem crossing events (triggered by spin-orbit coupling matrix elements) based on a spin-diabatic representation. The results of two numerical applications, a model system and the deactivation of thioformaldehyde, validate the presented formalism andmore » its implementation.« less
Curchod, Basile F. E.; Rauer, Clemens; Marquetand, Philipp; ...
2016-03-11
Full Multiple Spawning is a formally exact method to describe the excited-state dynamics of molecular systems beyond the Born-Oppenheimer approximation. However, it has been limited until now to the description of radiationless transitions taking place between electronic states with the same spin multiplicity. This Communication presents a generalization of the full and ab initio Multiple Spawning methods to both internal conversion (mediated by nonadiabatic coupling terms) and intersystem crossing events (triggered by spin-orbit coupling matrix elements) based on a spin-diabatic representation. Lastly, the results of two numerical applications, a model system and the deactivation of thioformaldehyde, validate the presented formalismmore » and its implementation.« less
Prospects for Genomic Selection in Cassava Breeding.
Wolfe, Marnin D; Del Carpio, Dunia Pino; Alabi, Olumide; Ezenwaka, Lydia C; Ikeogu, Ugochukwu N; Kayondo, Ismail S; Lozano, Roberto; Okeke, Uche G; Ozimati, Alfred A; Williams, Esuma; Egesi, Chiedozie; Kawuki, Robert S; Kulakow, Peter; Rabbi, Ismail Y; Jannink, Jean-Luc
2017-11-01
Cassava ( Crantz) is a clonally propagated staple food crop in the tropics. Genomic selection (GS) has been implemented at three breeding institutions in Africa to reduce cycle times. Initial studies provided promising estimates of predictive abilities. Here, we expand on previous analyses by assessing the accuracy of seven prediction models for seven traits in three prediction scenarios: cross-validation within populations, cross-population prediction and cross-generation prediction. We also evaluated the impact of increasing the training population (TP) size by phenotyping progenies selected either at random or with a genetic algorithm. Cross-validation results were mostly consistent across programs, with nonadditive models predicting of 10% better on average. Cross-population accuracy was generally low (mean = 0.18) but prediction of cassava mosaic disease increased up to 57% in one Nigerian population when data from another related population were combined. Accuracy across generations was poorer than within-generation accuracy, as expected, but accuracy for dry matter content and mosaic disease severity should be sufficient for rapid-cycling GS. Selection of a prediction model made some difference across generations, but increasing TP size was more important. With a genetic algorithm, selection of one-third of progeny could achieve an accuracy equivalent to phenotyping all progeny. We are in the early stages of GS for this crop but the results are promising for some traits. General guidelines that are emerging are that TPs need to continue to grow but phenotyping can be done on a cleverly selected subset of individuals, reducing the overall phenotyping burden. Copyright © 2017 Crop Science Society of America.
Bias correction for selecting the minimal-error classifier from many machine learning models.
Ding, Ying; Tang, Shaowu; Liao, Serena G; Jia, Jia; Oesterreich, Steffi; Lin, Yan; Tseng, George C
2014-11-15
Supervised machine learning is commonly applied in genomic research to construct a classifier from the training data that is generalizable to predict independent testing data. When test datasets are not available, cross-validation is commonly used to estimate the error rate. Many machine learning methods are available, and it is well known that no universally best method exists in general. It has been a common practice to apply many machine learning methods and report the method that produces the smallest cross-validation error rate. Theoretically, such a procedure produces a selection bias. Consequently, many clinical studies with moderate sample sizes (e.g. n = 30-60) risk reporting a falsely small cross-validation error rate that could not be validated later in independent cohorts. In this article, we illustrated the probabilistic framework of the problem and explored the statistical and asymptotic properties. We proposed a new bias correction method based on learning curve fitting by inverse power law (IPL) and compared it with three existing methods: nested cross-validation, weighted mean correction and Tibshirani-Tibshirani procedure. All methods were compared in simulation datasets, five moderate size real datasets and two large breast cancer datasets. The result showed that IPL outperforms the other methods in bias correction with smaller variance, and it has an additional advantage to extrapolate error estimates for larger sample sizes, a practical feature to recommend whether more samples should be recruited to improve the classifier and accuracy. An R package 'MLbias' and all source files are publicly available. tsenglab.biostat.pitt.edu/software.htm. ctseng@pitt.edu Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
exprso: an R-package for the rapid implementation of machine learning algorithms.
Quinn, Thomas; Tylee, Daniel; Glatt, Stephen
2016-01-01
Machine learning plays a major role in many scientific investigations. However, non-expert programmers may struggle to implement the elaborate pipelines necessary to build highly accurate and generalizable models. We introduce exprso , a new R package that is an intuitive machine learning suite designed specifically for non-expert programmers. Built initially for the classification of high-dimensional data, exprso uses an object-oriented framework to encapsulate a number of common analytical methods into a series of interchangeable modules. This includes modules for feature selection, classification, high-throughput parameter grid-searching, elaborate cross-validation schemes (e.g., Monte Carlo and nested cross-validation), ensemble classification, and prediction. In addition, exprso also supports multi-class classification (through the 1-vs-all generalization of binary classifiers) and the prediction of continuous outcomes.
Testing alternative ground water models using cross-validation and other methods
Foglia, L.; Mehl, S.W.; Hill, M.C.; Perona, P.; Burlando, P.
2007-01-01
Many methods can be used to test alternative ground water models. Of concern in this work are methods able to (1) rank alternative models (also called model discrimination) and (2) identify observations important to parameter estimates and predictions (equivalent to the purpose served by some types of sensitivity analysis). Some of the measures investigated are computationally efficient; others are computationally demanding. The latter are generally needed to account for model nonlinearity. The efficient model discrimination methods investigated include the information criteria: the corrected Akaike information criterion, Bayesian information criterion, and generalized cross-validation. The efficient sensitivity analysis measures used are dimensionless scaled sensitivity (DSS), composite scaled sensitivity, and parameter correlation coefficient (PCC); the other statistics are DFBETAS, Cook's D, and observation-prediction statistic. Acronyms are explained in the introduction. Cross-validation (CV) is a computationally intensive nonlinear method that is used for both model discrimination and sensitivity analysis. The methods are tested using up to five alternative parsimoniously constructed models of the ground water system of the Maggia Valley in southern Switzerland. The alternative models differ in their representation of hydraulic conductivity. A new method for graphically representing CV and sensitivity analysis results for complex models is presented and used to evaluate the utility of the efficient statistics. The results indicate that for model selection, the information criteria produce similar results at much smaller computational cost than CV. For identifying important observations, the only obviously inferior linear measure is DSS; the poor performance was expected because DSS does not include the effects of parameter correlation and PCC reveals large parameter correlations. ?? 2007 National Ground Water Association.
Rogers, R; Sewell, K W; Morey, L C; Ustad, K L
1996-12-01
Psychological assessment with multiscale inventories is largely dependent on the honesty and forthrightness of those persons evaluated. We investigated the effectiveness of the Personality Assessment Inventory (PAI) in detecting participants feigning three specific disorders: schizophrenia, major depression, and generalized anxiety disorder. With a simulation design, we tested the PAI validity scales on 166 naive (undergraduates with minimal preparation) and 80 sophisticated (doctoral psychology students with 1 week preparation) participants. We compared their results to persons with the designated disorders: schizophrenia (n = 45), major depression (n = 136), and generalized anxiety disorder (n = 40). Although moderately effective with naive simulators, the validity scales evidenced only modest positive predictive power with their sophisticated counterparts. Therefore, we performed a two-stage discriminant analysis that yielded a moderately high hit rate (> 80%) that was maintained in the cross-validation sample, irrespective of the feigned disorder or the sophistication of the simulators.
Hernandez, Matthew C; Aho, Johnathon M; Habermann, Elizabeth B; Choudhry, Asad J; Morris, David S; Zielinski, Martin D
2017-01-01
Determination and reporting of disease severity in emergency general surgery lacks standardization. Recently, the American Association for the Surgery of Trauma (AAST) proposed an anatomic severity grading system. We aimed to validate this system in patients with appendicitis and determine if cross-sectional imaging correlates with disease severity at operation. Patients 18 years or older undergoing treatment for acute appendicitis between 2013 and 2015 were identified. Baseline demographics, procedure types were recorded, and AAST grades were assigned based on intraoperative and radiologic findings. Outcomes including length of stay, 30-day mortality, and complications based on Clavien-Dindo categories and National Surgical Quality Improvement Program variables. Summary statistical univariate, nominal logistic, and standard least squares analyses were performed comparing AAST grade with key outcomes. Bland-Altman analysis compared operative findings with preoperative cross-sectional imaging to compare assigning grades. Three hundred thirty-four patients with mean (±SD) age of 39.3 years (±16.5) were included (53% men), and all patients had cross-sectional imaging. Two hundred ninety-nine underwent appendectomy, and 85% completed laparoscopic. Thirty-day mortality rate was 0.9%, complication rate was 21%. Increased (median [interquartile range, IQR]) AAST grade was recorded in patients with complications (2 [1-4]) compared with those without (1 [1-1], p = 0.001). For operative management, (median [IQR]) AAST grades were significantly associated with procedure type: laparoscopic (1 [1-1]), open (4 [2-5]), conversion to open (3 [1-4], p = 0.001). Increased (median [IQR]) AAST grades were significantly associated in nonoperative management: patients having a complication had a higher median AAST grade (4 [3-5]) compared with those without (3 [2-3], p = 0.001). Bland-Altman analysis comparing AAST grade and cross-sectional imaging demonstrated no difference (-0.02 ± 0.02; p = 0.2; coefficient of repeatability 0.9). The AAST grading system is valid in our population. Increased AAST grade is associated with open procedures, complications, and length of stay. The AAST emergency general surgery grade determined by preoperative imaging strongly correlated to operative findings. Epidemiologic/prognostic study, level III.
Validation of the Chinese expanded Euthanasia Attitude Scale.
Chong, Alice Ming-Lin; Fok, Shiu-Yeu
2013-01-01
This article reports the validation of the Chinese version of an expanded 31-item Euthanasia Attitude Scale. A 4-stage validation process included a pilot survey of 119 college students and a randomized household survey with 618 adults in Hong Kong. Confirmatory factor analysis confirmed a 4-factor structure of the scale, which can therefore be used to examine attitudes toward general, active, passive, and non-voluntary euthanasia. The scale considers the role effect in decision-making about euthanasia requests and facilitates cross-cultural comparison of attitudes toward euthanasia. The new Chinese scale is more robust than its Western predecessors conceptually and measurement-wise.
Universal Parameterization of Absorption Cross Sections
NASA Technical Reports Server (NTRS)
Tripathi, R. K.; Cucinotta, Francis A.; Wilson, John W.
1997-01-01
This paper presents a simple universal parameterization of total reaction cross sections for any system of colliding nuclei that is valid for the entire energy range from a few AMeV to a few AGeV. The universal picture presented here treats proton-nucleus collision as a special case of nucleus-nucleus collision, where the projectile has charge and mass number of one. The parameters are associated with the physics of the collision system. In general terms, Coulomb interaction modifies cross sections at lower energies, and the effects of Pauli blocking are important at higher energies. The agreement between the calculated and experimental data is better than all earlier published results.
The Precision Efficacy Analysis for Regression Sample Size Method.
ERIC Educational Resources Information Center
Brooks, Gordon P.; Barcikowski, Robert S.
The general purpose of this study was to examine the efficiency of the Precision Efficacy Analysis for Regression (PEAR) method for choosing appropriate sample sizes in regression studies used for precision. The PEAR method, which is based on the algebraic manipulation of an accepted cross-validity formula, essentially uses an effect size to…
Development and validation of a public attitudes toward epilepsy (PATE) scale.
Lim, Kheng-Seang; Wu, Cathie; Choo, Wan-Yuen; Tan, Chong-Tin
2012-06-01
A quantitative scale of public attitudes toward epilepsy is essential to determine the magnitude of social stigma against epilepsy. This study aims to develop and validate a cross-culturally applicable scale of public attitudes toward epilepsy. A set of questions was selected from questionnaires identified from a literature review, following which a panel review determined the final version, consisting of 18 items. A 1-5 Likert scale was used for scoring. Additional questions, related to perception of the productivity of people with epilepsy and of a modified epilepsy stigma scale, were added as part of construct validation. One hundred and thirty heterogeneous respondents were collected, consisting of various age groups, ethnicity and occupation status levels. After item and factor analyses, the final version consisted of 14 items. Psychometric properties of the scale were first determined using factor analysis, which revealed a general and a personal domain, with good internal consistency (Cronbach's coefficient 0.868 and 0.633, respectively). Construct validation was demonstrated. The mean score for the personal domain was higher than that for the general domain (2.72±0.56 and 2.09±0.59, respectively). The mean scores of those with tertiary education were significantly lower for the general domain, but not for the personal domain. Age was positively correlated with the mean scores in the personal domain, but not in the general domain. This scale is a reliable and valid scale to assess public attitudes toward epilepsy, in both the general and personal domains. Copyright © 2012 Elsevier Inc. All rights reserved.
Validation of the Fibromyalgia Survey Questionnaire within a Cross-Sectional Survey
Häuser, Winfried; Jung, Eva; Erbslöh-Möller, Brigitte; Gesmann, Mechthild; Kühn-Becker, Hedi; Petermann, Franz; Langhorst, Jost; Weiss, Thomas; Winkelmann, Andreas; Wolfe, Frederick
2012-01-01
The Fibromyalgia Survey Questionnaire (FSQ) assesses the key symptoms of fibromyalgia syndrome. The FSQ can be administrated in survey research and settings where the use of interviews to evaluate the number of pain sites and extent of somatic symptom intensity and tender point examination would be difficult. We validated the FSQ in a cross-sectional survey with FMS patients. In a cross-sectional survey, participants with physician diagnosis of FMS were recruited by FMS-self help organisations and nine clinical institutions of different levels of care. Participants answered the FSQ (composed by the Widespread Pain Index [WPI] and the Somatic Severity Score [SSS]) assessing the Fibromyalgia Survey Diagnostic Criteria (FSDC) and the Patient Health Questionnaire PHQ 4. American College of Rheumatology 1990 classification criteria were assessed in a subgroup of participants. 1,651 persons diagnosed with FMS were included into analysis. The acceptance of the FSQ-items ranged between 78.9 to 98.1% completed items. The internal consistency of the items of the SSS ranged between 0.75–0.82. 85.5% of the study participants met the FSDC. The concordance rate of the FSDC and ACR 1990 criteria was 72.7% in a subsample of 128 patients. The Pearson correlation of the SSS with the PHQ 4 depression score was 0.52 (p<0.0001) and with the PHQ anxiety score was 0.51 (p<0.0001) (convergent validity). 64/202 (31.7%) of the participants not meeting the FSDC criteria and 152/1283 (11.8%) of the participants meeting the FSDC criteria reported an improvement (slightly too very much better) in their health status since FMS-diagnosis (Chi2 = 55, p<0.0001) (discriminant validity). The study demonstrated the feasibility of the FSQ in a cross-sectional survey with FMS-patients. The reliability, convergent and discriminant validity of the FSQ were good. Further validation studies of the FSQ in clinical and general population settings are necessary. PMID:22662163
Xu, Xianghua; Liu, Xiangyu; Ou, Meijun; Xie, Chanjuan; Chen, Yongyi
2018-01-01
To translate the English work-related acceptance and action questionnaire (WAAQ), make cross-cultural adaptations, and examine its psychometric properties when used by Chinese oncology nurses. After translation, the psychometric properties of the Chinese WAAQ were analyzed among 417 nurses, and content validity was determined by six experts. Item-level content validity index (CVI) values were between 0.83 and 1.00; scale-level CVI/universal agreement (S-CVI/UA) and S-CVI/average were 0.86 and 0.98, respectively, which implicated a good content validity. The correlation of the Chinese WAAQ with AAQ-II ( r s = -0.247, P < 0.001) suggested criterion validity, and those with General Health Questionnaire-12 (-0.250, <0.001) and general self-efficacy scale (0.491, <0.001) and Utrecht work engagement scale (UWES) (0.439, <0.001) suggested convergent validity. Exploratory factor analysis identified a seven-item, one-factor structure of WAAQ. The Chinese version of WAAQ had high internal consistency (Cronbach's α = 0.920), with an item-total correlation coefficient of 0.702-0.828 ( P < 0.05), split-half reliability of 0.933, and test-retest reliability of 0.772. The Chinese WAAQ is a reliable and valid tool for assessing psychological flexibility in Chinese oncology nurses.
Optical-model abrasion cross sections for high-energy heavy ions
NASA Technical Reports Server (NTRS)
Townsend, L. W.
1981-01-01
Within the context of eikonal scattering theory, a generalized optical model potential approximation to the nucleus-nucleus multiple scattering series is used in an abrasion-ablation collision model to predict abrasion cross sections for relativistic projectile heavy ions. Unlike the optical limit of Glauber theory, which cannot be used for very light nuclei, the abrasion formalism is valid for any projectile target combination at any incident kinetic energy for which eikonal scattering theory can be utilized. Results are compared with experimental results and predictions from Glauber theory.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Anastasiou, Charalampos; Duhr, Claude; Dulat, Falko
In this study, we compute the gluon fusion Higgs boson cross-section at N 3LO through the second term in the threshold expansion. This calculation constitutes a major milestone towards the full N 3LO cross section. Our result has the best formal accuracy in the threshold expansion currently available, and includes contributions from collinear regions besides subleading corrections from soft and hard regions, as well as certain logarithmically enhanced contributions for general kinematics. We use our results to perform a critical appraisal of the validity of the threshold approximation at N 3LO in perturbative QCD.
Peláez-Fernández, María Angeles; Ruiz-Lázaro, Pedro Manuel; Labrador, Francisco Javier; Raich, Rosa María
2014-02-20
To validate the best cut-off point of the Eating Attitudes Test (EAT-40), Spanish version, for the screening of eating disorders (ED) in the general population. This was a transversal cross-sectional study. The EAT-40 Spanish version was administered to a representative sample of 1.543 students, age range 12 to 21 years, in the Region of Madrid. Six hundred and two participants (probable cases and a random sample of controls) were interviewed. The best diagnostic prediction was obtained with a cut-off point of 21, with sensitivity: 88.2%; specificity: 62.1%; positive predictive value: 17.7%; negative predictive value: 62.1%. Use of a cut-off point of 21 is recommended in epidemiological studies of eating disorders in the Spanish general population. Copyright © 2012 Elsevier España, S.L. All rights reserved.
Hasanpour, Neda; Attarbashi Moghadam, Behrouz; Sami, Ramin; Tavakol, Kamran
2016-08-01
The clinical COPD questionnaire (CCQ) has been developed to measure the health status of COPD patients. The aim of this study was to translate CCQ into the Persian language and assess the validity and reliability of the translated version. We used a forward-backward procedure to translate the questionnaire. In a cross-sectional study 100 COPD patients and 50 healthy subjects over 40 years old were selected to assess the reliability and construct validity of the instrument. The face and content validity were used for the questionnaire validity. Validity was examined in a population of patients with COPD, using the Persian validated version of the St George's Respiratory Questionnaire (PSGRQ). In order to assess the questionnaire's reliability, the Intraclass correlation coefficient (ICC) and Cronbach's alpha were calculated. Test-retest reliability was tested by re-administering the Persian version of the CCQ (PCCQ) after 1 week. Test-retest carry out of data demonstrates that the PCCQ has excellent reliability (ICC for all 3 domains were higher than 0.9). Internal consistency was found by Cronbach's alpha to be 0.96, 0.94, 0.97, and 0.98 for the symptom, mental state, functional state and total scores respectively. In addition, the correlation between the components of PCCQ and PSGRQ showed satisfactory construct validity. Analyzing the data from healthy subjects and patients divulged that the PCCQ has acceptable discriminant validity. In general, the PCCQ had satisfactory reliability and validity for assessing health-related quality of life status of Iranian COPD patients.
[Validation of the German version of the Oxford Elbow Score : A cross-sectional study].
Marquardt, J; Schöttker-Königer, T; Schäfer, A
2016-08-01
Elbow complaints are complex problems leading to severe consequences for affected people and the healthcare system. The German version of the Oxford Elbow Score (OES) is the first German-speaking instrument that specifically measures elbow complaints from the patient's perspective and changes of their health status. The aim of this study is the validation of the German version of the OES. In this context the internal consistency and the construct validity were investigated. 59 patients with elbow complaints completed the German version of the OES, the DASH and the SF-36 in a cross-sectional study. The internal consistency was calculated with Cronbach's alpha coefficients. Spearman's correlation coefficients were used to confirm construct validity. Cronbach's alpha for pain, function and psychological subscales was 0.88, 0.81 and 0.90, respectively. The whole questionnaire presents a Cronbach's alpha value of 0.93. Convergent construct validity was confirmed with correlation coefficients containing values of -0.84, -0.77 and -0.82 compared to DASH and values ranging from 0.41 to 0.80 compared with the physical domains of the SF-36. The divergent construct validity presented values ranging from 0.07 to 0.20 with the SF-36 domains of "general health perception" and "mental health". The German OES is an internal consistent instrument with good convergent and divergent construct validity. Other aspects of the validity, the reliability and the responsiveness should be confirmed through further studies.
Bártolo, Ana; Monteiro, Sara; Pereira, Anabela
2017-09-28
: The Generalized Anxiety Disorder 7-item (GAD-7) scale has been presented as a reliable and valid measure to assess generalized anxiety symptoms in several clinical settings and among the general population. However, some researches did not support the original one-dimensional structure of the GAD-7 tool. Our main aim was to examine the factor structure of GAD-7 comparing the one-factor model fit with a two-factor model (3 somatic nature symptoms and 4 cognitive-emotional nature symptoms) in a sample of college students. This validation study with data collected cross-sectionally included 1,031 Portuguese college students attending courses in the six schools of the Polytechnic Institute of Coimbra, Coimbra, Portugal. Measures included the GAD-7, Hospital Anxiety and Depression Scale (HADS) and the University Student Risk Behaviors Questionnaire. Confirmatory factor analysis (CFA) procedures confirmed that neither factor structure was well fitting. Thus, a modified single factor model allowing the error terms of items associated with relaxing difficulties and irritability to covary was an appropriate solution. Additionally, this factor structure revealed configural and metric invariance across gender. A good convergent validity was found by correlating global anxiety and depression. However, this measure showed a weak association with consumption behaviors. Our results are relevant to clinical practice, since the comprehensive approach to GAD-7 contributes to knowing generalized anxiety symptoms trajectory and their correlates within the university setting.
Mullally, B J; Greiner, B A; Allwright, S; Paul, G; Perry, I J
2008-12-01
This study establishes baseline prevalence of smoking and cigarette consumption among Cork bar workers prior to the Republic of Ireland's (ROI) smokefree workplace legislation and compares gender- and age-specific smoking rates and estimates the adjusted odds of being a smoker for Cork bar workers relative to the general population. Cross-sectional random sample of bar workers in Cork city and cross-sectional random telephone survey of the general population were conducted prior to the smokefree legislation. Self reported smoking prevalence among Cork bar workers (n = 129) was 54% (58% using cotinine-validated measures), with particularly high rates in women (70%) and 18-28 years old (72%). Within the ROI (n = 1,240) sub-sample rates were substantially lower at 28%. Bar workers were twice as likely to be smokers as the general population sub-sample (OR = 2.15). Cork bar workers constitute an occupational group with an extremely high smoking prevalence.
Liu, A; Byrne, N M; Ma, G; Nasreddine, L; Trinidad, T P; Kijboonchoo, K; Ismail, M N; Kagawa, M; Poh, B K; Hills, A P
2011-12-01
To develop and cross-validate bioelectrical impedance analysis (BIA) prediction equations of total body water (TBW) and fat-free mass (FFM) for Asian pre-pubertal children from China, Lebanon, Malaysia, Philippines and Thailand. Height, weight, age, gender, resistance and reactance measured by BIA were collected from 948 Asian children (492 boys and 456 girls) aged 8-10 years from the five countries. The deuterium dilution technique was used as the criterion method for the estimation of TBW and FFM. The BIA equations were developed using stepwise multiple regression analysis and cross-validated using the Bland-Altman approach. The BIA prediction equation for the estimation of TBW was as follows: TBW=0.231 × height(2)/resistance+0.066 × height+0.188 × weight+0.128 × age+0.500 × sex-0.316 × Thais-4.574 (R (2)=88.0%, root mean square error (RMSE)=1.3 kg), and for the estimation of FFM was as follows: FFM=0.299 × height(2)/resistance+0.086 × height+0.245 × weight+0.260 × age+0.901 × sex-0.415 × ethnicity (Thai ethnicity =1, others = 0)-6.952 (R (2)=88.3%, RMSE=1.7 kg). No significant difference between measured and predicted values for the whole cross-validation sample was found. However, the prediction equation for estimation of TBW/FFM tended to overestimate TBW/FFM at lower levels whereas underestimate at higher levels of TBW/FFM. Accuracy of the general equation for TBW and FFM was also valid at each body mass index category. Ethnicity influences the relationship between BIA and body composition in Asian pre-pubertal children. The newly developed BIA prediction equations are valid for use in Asian pre-pubertal children.
Song, Jungeun; Leventhal, Bennett L.; Koh, Yun-Joo; Cheon, Keun-Ah; Hong, Hyun Ju; Kim, Young-Key; Cho, Kyungjin; Lim, Eun-Chung; Park, Jee In
2017-01-01
Purpose Our study aimed to examine psychometric properties and cross-cultural utility of the Behavior Assessment System for Children-2, Parent Rating Scale-Child (BASC-2 PRS-C) in Korean children. Materials and Methods Two study populations were recruited: a general population sample (n=2115) of 1st to 6th graders from 16 elementary schools and a clinical population (n=219) of 6–12 years old from 5 child psychiatric clinics and an epidemiological sample of autism spectrum disorder. We assessed the validity and reliability of the Korean version of BASC-2 PRS-C (K-BASC-2 PRS-C) and compared subscales with those used for US populations. Results Our results indicate that the K-BASC-2 PRS-C is a valuable instrument with reliability and validity for measuring developmental psychopathology that is comparable to those in Western population. However, there were some differences noted in the mean scores of BASC-2 PRS-C between Korean and US populations. Conclusion K-BASC-2 PRS-C is an effective and useful instrument with psychometric properties that permits measurement of general developmental psychopathology. Observed Korean-US differences in patterns of parental reports of children's behaviors indicate the importance of the validation, standardization and cultural adaptation for tools assessing psychopathology especially when used in populations different from those for which the instrument was originally created. PMID:28120577
Song, Jungeun; Leventhal, Bennett L; Koh, Yun Joo; Cheon, Keun Ah; Hong, Hyun Ju; Kim, Young Key; Cho, Kyungjin; Lim, Eun Chung; Park, Jee In; Kim, Young Shin
2017-03-01
Our study aimed to examine psychometric properties and cross-cultural utility of the Behavior Assessment System for Children-2, Parent Rating Scale-Child (BASC-2 PRS-C) in Korean children. Two study populations were recruited: a general population sample (n=2115) of 1st to 6th graders from 16 elementary schools and a clinical population (n=219) of 6-12 years old from 5 child psychiatric clinics and an epidemiological sample of autism spectrum disorder. We assessed the validity and reliability of the Korean version of BASC-2 PRS-C (K-BASC-2 PRS-C) and compared subscales with those used for US populations. Our results indicate that the K-BASC-2 PRS-C is a valuable instrument with reliability and validity for measuring developmental psychopathology that is comparable to those in Western population. However, there were some differences noted in the mean scores of BASC-2 PRS-C between Korean and US populations. K-BASC-2 PRS-C is an effective and useful instrument with psychometric properties that permits measurement of general developmental psychopathology. Observed Korean-US differences in patterns of parental reports of children's behaviors indicate the importance of the validation, standardization and cultural adaptation for tools assessing psychopathology especially when used in populations different from those for which the instrument was originally created.
NG, Chong Guan; CHIN, Soo Cheng; YEE, Anne Hway Ann; LOH, Huai Seng; SULAIMAN, Ahmad Hatim; Sherianne Sook Kuan, WONG; HABIL, Mohamed Hussain
2014-01-01
Background: The Snaith-Hamilton Pleasure Scale (SHAPS) is a self-assessment scale designed to evaluate anhedonia in various psychiatric disorders. In order to facilitate its use in Malaysian settings, our current study aimed to examine the validity of a Malay-translated version of the SHAPS (SHAPS-M). Methods: In this cross-sectional study, a total of 44 depressed patients and 82 healthy subjects were recruited from a university out-patient clinic. All participants were given both the Malay and English versions of the SHAPS, Fawcett-Clark Pleasure Scale (FCPS), General Health Questionnaire 12 (GHQ-12), and the Beck Depression Inventory (BDI) to assess their hedonic state, general mental health condition and levels of depression. Results: The results showed that the SHAPS-M has impressive internal consistency (α = 0.96), concurrent validity and good parallel-form reliability (intraclass coefficient, ICC = 0.65). Conclusion: In addition to demonstrating good psychometric properties, the SHAPS-M is easy to administer. Therefore, it is a valid, reliable, and suitable questionnaire for assessing anhedonia among depressed patients in Malaysia. PMID:25246837
Ng, Chong Guan; Chin, Soo Cheng; Yee, Anne Hway Ann; Loh, Huai Seng; Sulaiman, Ahmad Hatim; Sherianne Sook Kuan, Wong; Habil, Mohamed Hussain
2014-05-01
The Snaith-Hamilton Pleasure Scale (SHAPS) is a self-assessment scale designed to evaluate anhedonia in various psychiatric disorders. In order to facilitate its use in Malaysian settings, our current study aimed to examine the validity of a Malay-translated version of the SHAPS (SHAPS-M). In this cross-sectional study, a total of 44 depressed patients and 82 healthy subjects were recruited from a university out-patient clinic. All participants were given both the Malay and English versions of the SHAPS, Fawcett-Clark Pleasure Scale (FCPS), General Health Questionnaire 12 (GHQ-12), and the Beck Depression Inventory (BDI) to assess their hedonic state, general mental health condition and levels of depression. The results showed that the SHAPS-M has impressive internal consistency (α = 0.96), concurrent validity and good parallel-form reliability (intraclass coefficient, ICC = 0.65). In addition to demonstrating good psychometric properties, the SHAPS-M is easy to administer. Therefore, it is a valid, reliable, and suitable questionnaire for assessing anhedonia among depressed patients in Malaysia.
Chabrera, Carolina; Areal, Joan; Font, Albert; Caro, Mónica; Bonet, Marta; Zabalegui, Adelaida
2015-01-01
The aim of this study is to develop a Spanish version of the Satisfaction With Decision scale (SWDs) and analyse the psychometric properties of validity and reliability. An observational, descriptive study and validation of a tool to measure satisfaction with the decision. Urology, Radiation oncology, and Medical oncology Departments of the Hospital Universitari Germans Trias i Pujol, Institut Català d'Oncologia and the Institut Oncològic del Vallès - Hospital General de Catalunya. A total of 170 participants diagnosed with prostate cancer, and who could read and write in Spanish and gave their informed consent. A translation, back-translation and cross-cultural adaptation to Spanish was performed on the SWDs. The content validity, criterion validity, construct validity and reliability (internal consistency and stability) of the Spanish version were evaluated. The SWDs contains 6 items with 5-item Likert scales. A Spanish version (ESD) was obtained that was linguistically and conceptually equivalent to the original version. Criterion validity, the ESD correlated with "satisfaction with the decision" using a linear analogue scale, was significant (r=0.63, P<.01) for all items. The factorial analysis showed a unique dimension to explain 82.08% of the variance. The ESD showed excellent results in terms of internal consistency (Cronbach alpha=0.95) and good test-retest reliability with intraclass correlation coefficient of 0.711. The ESD is a validated Spanish scale to measure the satisfaction with the decisions taken in health, and demonstrates a correct validity and reliability. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.
De Vet, Emely; De Ridder, Denise; Stok, Marijn; Brunso, Karen; Baban, Adriana; Gaspar, Tania
2014-09-02
Applying self-regulation strategies have proven important in eating behaviors, but it remains subject to investigation what strategies adolescents report to use to ensure healthy eating, and adequate measures are lacking. Therefore, we developed and validated a self-regulation questionnaire applied to eating (TESQ-E) for adolescents. Study 1 reports a four-step approach to develop the TESQ-E questionnaire (n = 1097). Study 2 was a cross-sectional survey among adolescents from nine European countries (n = 11,392) that assessed the TESQ-E, eating-related behaviors, dietary intake and background characteristics. In study 3, the TESQ-E was administered twice within four weeks to evaluate test-retest reliability (n = 140). Study 4 was a cross-sectional survey (n = 93) that assessed the TESQ-E and related psychological constructs (e.g., motivation, autonomy, self-control). All participants were aged between 10 and 17 years. Study 1 resulted in a 24-item questionnaire assessing adolescent-reported use of six specific strategies for healthy eating that represent three general self-regulation approaches. Study 2 showed that the easy-to-administer theory-based TESQ-E has a clear factor structure and good subscale reliabilities. The questionnaire was related to eating-related behaviors and dietary intake, indicating predictive validity. Study 3 showed good test-retest reliabilities for the TESQ-E. Study 4 indicated that TESQ-E was related to but also distinguishable from general self-regulation and motivation measures. The TESQ-E provides a reliable and valid measure to assess six theory-based self-regulation strategies that adolescents may use to ensure their healthy eating.
Trauma Coping Self-Efficacy: A Context Specific Self-Efficacy Measure for Traumatic Stress
Benight, Charles C.; Shoji, Kotaro; James, Lori E.; Waldrep, Edward E.; Delahanty, Douglas L.; Cieslak, Roman
2015-01-01
The psychometric properties of a Trauma Coping Self-Efficacy (CSE-T) scale that assesses general trauma-related coping self-efficacy perceptions were assessed. Measurement equivalence was assessed using several different samples: hospitalized trauma patients (n1 = 74, n2 = 69, n3 = 60), three samples of disaster survivors (n1 = 273, n2 = 227, n3 = 138), and trauma exposed college students (N = 242). This is the first multi-sample evaluation of the psychometric properties for a general trauma-related CSE measure. Results showed that a brief and parsimonious 9-item version of the CSE performed well across the samples with a robust factor structure; factor structure and factor loadings were similar across study samples. The 9-item scale CSE-T demonstrated measurement equivalence across samples indicating that the underlying concept of general post-traumatic CSE is organized in a similar manner in the different trauma-exposed groups. These results offer strong support for cross-event construct validity of the CSE-T scale. Associations of the CSE-T with important expected covariates showed significant evidence for convergent validity. Finally, discriminant validity was also supported. Replication of the factor structure, internal reliability, and other evidence for construct validity is a critical next step for future research. PMID:26524542
An empirical assessment of validation practices for molecular classifiers
Castaldi, Peter J.; Dahabreh, Issa J.
2011-01-01
Proposed molecular classifiers may be overfit to idiosyncrasies of noisy genomic and proteomic data. Cross-validation methods are often used to obtain estimates of classification accuracy, but both simulations and case studies suggest that, when inappropriate methods are used, bias may ensue. Bias can be bypassed and generalizability can be tested by external (independent) validation. We evaluated 35 studies that have reported on external validation of a molecular classifier. We extracted information on study design and methodological features, and compared the performance of molecular classifiers in internal cross-validation versus external validation for 28 studies where both had been performed. We demonstrate that the majority of studies pursued cross-validation practices that are likely to overestimate classifier performance. Most studies were markedly underpowered to detect a 20% decrease in sensitivity or specificity between internal cross-validation and external validation [median power was 36% (IQR, 21–61%) and 29% (IQR, 15–65%), respectively]. The median reported classification performance for sensitivity and specificity was 94% and 98%, respectively, in cross-validation and 88% and 81% for independent validation. The relative diagnostic odds ratio was 3.26 (95% CI 2.04–5.21) for cross-validation versus independent validation. Finally, we reviewed all studies (n = 758) which cited those in our study sample, and identified only one instance of additional subsequent independent validation of these classifiers. In conclusion, these results document that many cross-validation practices employed in the literature are potentially biased and genuine progress in this field will require adoption of routine external validation of molecular classifiers, preferably in much larger studies than in current practice. PMID:21300697
Zhang, Zhaoyang; Fang, Hua; Wang, Honggang
2016-06-01
Web-delivered trials are an important component in eHealth services. These trials, mostly behavior-based, generate big heterogeneous data that are longitudinal, high dimensional with missing values. Unsupervised learning methods have been widely applied in this area, however, validating the optimal number of clusters has been challenging. Built upon our multiple imputation (MI) based fuzzy clustering, MIfuzzy, we proposed a new multiple imputation based validation (MIV) framework and corresponding MIV algorithms for clustering big longitudinal eHealth data with missing values, more generally for fuzzy-logic based clustering methods. Specifically, we detect the optimal number of clusters by auto-searching and -synthesizing a suite of MI-based validation methods and indices, including conventional (bootstrap or cross-validation based) and emerging (modularity-based) validation indices for general clustering methods as well as the specific one (Xie and Beni) for fuzzy clustering. The MIV performance was demonstrated on a big longitudinal dataset from a real web-delivered trial and using simulation. The results indicate MI-based Xie and Beni index for fuzzy-clustering are more appropriate for detecting the optimal number of clusters for such complex data. The MIV concept and algorithms could be easily adapted to different types of clustering that could process big incomplete longitudinal trial data in eHealth services.
Zhang, Zhaoyang; Wang, Honggang
2016-01-01
Web-delivered trials are an important component in eHealth services. These trials, mostly behavior-based, generate big heterogeneous data that are longitudinal, high dimensional with missing values. Unsupervised learning methods have been widely applied in this area, however, validating the optimal number of clusters has been challenging. Built upon our multiple imputation (MI) based fuzzy clustering, MIfuzzy, we proposed a new multiple imputation based validation (MIV) framework and corresponding MIV algorithms for clustering big longitudinal eHealth data with missing values, more generally for fuzzy-logic based clustering methods. Specifically, we detect the optimal number of clusters by auto-searching and -synthesizing a suite of MI-based validation methods and indices, including conventional (bootstrap or cross-validation based) and emerging (modularity-based) validation indices for general clustering methods as well as the specific one (Xie and Beni) for fuzzy clustering. The MIV performance was demonstrated on a big longitudinal dataset from a real web-delivered trial and using simulation. The results indicate MI-based Xie and Beni index for fuzzy-clustering is more appropriate for detecting the optimal number of clusters for such complex data. The MIV concept and algorithms could be easily adapted to different types of clustering that could process big incomplete longitudinal trial data in eHealth services. PMID:27126063
Multivariate pattern analysis for MEG: A comparison of dissimilarity measures.
Guggenmos, Matthias; Sterzer, Philipp; Cichy, Radoslaw Martin
2018-06-01
Multivariate pattern analysis (MVPA) methods such as decoding and representational similarity analysis (RSA) are growing rapidly in popularity for the analysis of magnetoencephalography (MEG) data. However, little is known about the relative performance and characteristics of the specific dissimilarity measures used to describe differences between evoked activation patterns. Here we used a multisession MEG data set to qualitatively characterize a range of dissimilarity measures and to quantitatively compare them with respect to decoding accuracy (for decoding) and between-session reliability of representational dissimilarity matrices (for RSA). We tested dissimilarity measures from a range of classifiers (Linear Discriminant Analysis - LDA, Support Vector Machine - SVM, Weighted Robust Distance - WeiRD, Gaussian Naïve Bayes - GNB) and distances (Euclidean distance, Pearson correlation). In addition, we evaluated three key processing choices: 1) preprocessing (noise normalisation, removal of the pattern mean), 2) weighting decoding accuracies by decision values, and 3) computing distances in three different partitioning schemes (non-cross-validated, cross-validated, within-class-corrected). Four main conclusions emerged from our results. First, appropriate multivariate noise normalization substantially improved decoding accuracies and the reliability of dissimilarity measures. Second, LDA, SVM and WeiRD yielded high peak decoding accuracies and nearly identical time courses. Third, while using decoding accuracies for RSA was markedly less reliable than continuous distances, this disadvantage was ameliorated by decision-value-weighting of decoding accuracies. Fourth, the cross-validated Euclidean distance provided unbiased distance estimates and highly replicable representational dissimilarity matrices. Overall, we strongly advise the use of multivariate noise normalisation as a general preprocessing step, recommend LDA, SVM and WeiRD as classifiers for decoding and highlight the cross-validated Euclidean distance as a reliable and unbiased default choice for RSA. Copyright © 2018 Elsevier Inc. All rights reserved.
Trakman, Gina Louise; Forsyth, Adrienne; Hoye, Russell; Belski, Regina
2018-01-01
The Nutrition for Sport Knowledge Questionnaire (NSKQ) is an 89-item, valid and reliable measure of sports nutrition knowledge (SNK). It takes 25 min to complete and has been subject to low completion and response rates. The aim of this study was to develop an abridged version of the NSKQ (A-NSKQ) and compare response rates, completion rates and NK scores of the NSKQ and A-NSKQ. Rasch analysis was used for the questionnaire validation. The sample ( n = 181) was the same sample that was used in the validation of the full-length NSKQ. Construct validity was assessed using the known-group comparisons method. Temporal stability was assessed using the test-retest reliability method. NK assessment was cross-sectional; responses were collected electronically from members of one non-elite Australian football (AF) and netball club, using Qualtrics Software (Qualtrics, Provo, UT). Validation - The A-NSKQ has 37 items that assess general ( n = 17) and sports ( n = 20) nutrition knowledge (NK). Both sections are unidimensional (Perc5% = 2.84% [general] and 3.41% [sport]). Both sections fit the Rasch Model (overall-interaction statistic mean (SD) = - 0.15 ± 0.96 [general] and 0.22 ± 1.11 [sport]; overall-person interaction statistic mean (SD) = - 0.11 ± 0.61 [general] and 0.08 ± 0.73 [sport]; Chi-Square probability = 0.308 [general] and 0.283 [sport]). Test-retest reliability was confirmed ( r = 0.8, P < 0.001 [general] and r = 0.7, P < 0.001 [sport]). Construct validity was demonstrated (nutrition students = 77% versus non-nutrition students = 60%, P < 0.001 [general] and nutrition students = 60% versus non-nutrition students = 40%, P < 0.001 [sport]. Assessment of NK - 177 usable survey responses from were returned. Response rates were low (7%) but completion rates were high (85%). NK scores on the A-NSKQ (46%) are comparable to results obtained in similar cohorts on the NSKQ (49%). The A-NSKQ took on average 12 min to complete, which is around half the time taken to complete the NSKQ (25 min). The A-NSKQ is a valid and reliable, brief questionnaire designed to assess general NK (GNK) and SNK.
Quantifying cardiometabolic risk using modifiable non-self-reported risk factors.
Marino, Miguel; Li, Yi; Pencina, Michael J; D'Agostino, Ralph B; Berkman, Lisa F; Buxton, Orfeu M
2014-08-01
Sensitive general cardiometabolic risk assessment tools of modifiable risk factors would be helpful and practical in a range of primary prevention interventions or for preventive health maintenance. To develop and validate a cumulative general cardiometabolic risk score that focuses on non-self-reported modifiable risk factors such as glycosylated hemoglobin (HbA1c) and BMI so as to be sensitive to small changes across a span of major modifiable risk factors, which may not individually cross clinical cut-off points for risk categories. We prospectively followed 2,359 cardiovascular disease (CVD)-free subjects from the Framingham offspring cohort over a 14-year follow-up. Baseline (fifth offspring examination cycle) included HbA1c and cholesterol measurements. Gender-specific Cox proportional hazards models were considered to evaluate the effects of non-self-reported modifiable risk factors (blood pressure, total cholesterol, high-density lipoprotein cholesterol, smoking, BMI, and HbA1c) on general CVD risk. We constructed 10-year general cardiometabolic risk score functions and evaluated its predictive performance in 2012-2013. HbA1c was significantly related to general CVD risk. The proposed cardiometabolic general CVD risk model showed good predictive performance as determined by cross-validated discrimination (male C-index=0.703, 95% CI=0.668, 0.734; female C-index=0.762, 95% CI=0.726, 0.801) and calibration (lack-of-fit chi-square=9.05 [p=0.338] and 12.54 [p=0.128] for men and women, respectively). This study presents a risk factor algorithm that provides a convenient and informative way to quantify cardiometabolic risk on the basis of modifiable risk factors that can motivate an individual's commitment to prevention and intervention. Copyright © 2014 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
Quantifying Cardiometabolic Risk Using Modifiable Non–Self-Reported Risk Factors
Marino, Miguel; Li, Yi; Pencina, Michael J.; D’Agostino, Ralph B.; Berkman, Lisa F.; Buxton, Orfeu M.
2014-01-01
Background Sensitive general cardiometabolic risk assessment tools of modifiable risk factors would be helpful and practical in a range of primary prevention interventions or for preventive health maintenance. Purpose To develop and validate a cumulative general cardiometabolic risk score that focuses on non–self-reported modifiable risk factors such as glycosylated hemoglobin (HbA1c) and BMI so as to be sensitive to small changes across a span of major modifiable risk factors, which may not individually cross clinical cut off points for risk categories. Methods We prospectively followed 2,359 cardiovascular disease (CVD)-free subjects from the Framingham offspring cohort over a 14–year follow-up. Baseline (fifth offspring examination cycle) included HbA1c and cholesterol measurements. Gender–specific Cox proportional hazards models were considered to evaluate the effects of non–self-reported modifiable risk factors (blood pressure, total cholesterol, high–density lipoprotein cholesterol, smoking, BMI, and HbA1c) on general CVD risk. We constructed 10–year general cardiometabolic risk score functions and evaluated its predictive performance in 2012–2013. Results HbA1c was significantly related to general CVD risk. The proposed cardiometabolic general CVD risk model showed good predictive performance as determined by cross-validated discrimination (male C-index=0.703, 95% CI=0.668, 0.734; female C-index=0.762, 95% CI=0.726, 0.801) and calibration (lack-of-fit χ2=9.05 [p=0.338] and 12.54 [p=0.128] for men and women, respectively). Conclusions This study presents a risk factor algorithm that provides a convenient and informative way to quantify cardiometabolic risk based on modifiable risk factors that can motivate an individual’s commitment to prevention and intervention. PMID:24951039
Development and Validation of the Elder Learning Barriers Scale Among Older Chinese Adults.
Wang, Renfeng; De Donder, Liesbeth; De Backer, Free; He, Tao; Van Regenmortel, Sofie; Li, Shihua; Lombaerts, Koen
2017-12-01
This study describes the development and validation of the Elder Learning Barriers (ELB) scale, which seeks to identify the obstacles that affect the level of educational participation of older adults. The process of item pool design and scale development is presented, as well as the testing and scale refinement procedure. The data were collected from a sample of 579 older Chinese adults (aged over 55) in the Xi'an region of China. After randomly splitting the sample for cross-validation purposes, the construct validity of the ELB scale was confirmed containing five dimensions: dispositional, informational, physical, situational, and institutional barriers. Furthermore, developmental differences in factor structure have been examined among older age groups. The results indicated that the scale demonstrated good reliability and validity. We conclude in general that the ELB scale appears to be a valuable instrument for examining the learning barriers that older Chinese citizens experience for participating in organized educational activities.
ERIC Educational Resources Information Center
Breuer, Christoph; Wicker, Pamela
2009-01-01
According to cross-sectional studies in sport science literature, decreasing sports activity with increasing age is generally assumed. In this paper, the validity of this assumption is checked by applying more effective methods of analysis, such as longitudinal and cohort sequence analyses. With the help of 20 years' worth of data records from the…
Sound quality indicators for urban places in Paris cross-validated by Milan data.
Ricciardi, Paola; Delaitre, Pauline; Lavandier, Catherine; Torchia, Francesca; Aumond, Pierre
2015-10-01
A specific smartphone application was developed to collect perceptive and acoustic data in Paris. About 3400 questionnaires were analyzed, regarding the global sound environment characterization, the perceived loudness of some emergent sources and the presence time ratio of sources that do not emerge from the background. Sound pressure level was recorded each second from the mobile phone's microphone during a 10-min period. The aim of this study is to propose indicators of urban sound quality based on linear regressions with perceptive variables. A cross validation of the quality models extracted from Paris data was carried out by conducting the same survey in Milan. The proposed sound quality general model is correlated with the real perceived sound quality (72%). Another model without visual amenity and familiarity is 58% correlated with perceived sound quality. In order to improve the sound quality indicator, a site classification was performed by Kohonen's Artificial Neural Network algorithm, and seven specific class models were developed. These specific models attribute more importance on source events and are slightly closer to the individual data than the global model. In general, the Parisian models underestimate the sound quality of Milan environments assessed by Italian people.
Waples, Robin S
2010-07-01
Recognition of the importance of cross-validation ('any technique or instance of assessing how the results of a statistical analysis will generalize to an independent dataset'; Wiktionary, en.wiktionary.org) is one reason that the U.S. Securities and Exchange Commission requires all investment products to carry some variation of the disclaimer, 'Past performance is no guarantee of future results.' Even a cursory examination of financial behaviour, however, demonstrates that this warning is regularly ignored, even by those who understand what an independent dataset is. In the natural sciences, an analogue to predicting future returns for an investment strategy is predicting power of a particular algorithm to perform with new data. Once again, the key to developing an unbiased assessment of future performance is through testing with independent data--that is, data that were in no way involved in developing the method in the first place. A 'gold-standard' approach to cross-validation is to divide the data into two parts, one used to develop the algorithm, the other used to test its performance. Because this approach substantially reduces the sample size that can be used in constructing the algorithm, researchers often try other variations of cross-validation to accomplish the same ends. As illustrated by Anderson in this issue of Molecular Ecology Resources, however, not all attempts at cross-validation produce the desired result. Anderson used simulated data to evaluate performance of several software programs designed to identify subsets of loci that can be effective for assigning individuals to population of origin based on multilocus genetic data. Such programs are likely to become increasingly popular as researchers seek ways to streamline routine analyses by focusing on small sets of loci that contain most of the desired signal. Anderson found that although some of the programs made an attempt at cross-validation, all failed to meet the 'gold standard' of using truly independent data and therefore produced overly optimistic assessments of power of the selected set of loci--a phenomenon known as 'high grading bias.'
Xu, Xianghua; Liu, Xiangyu; Ou, Meijun; Xie, Chanjuan; Chen, Yongyi
2018-01-01
Objective: To translate the English work-related acceptance and action questionnaire (WAAQ), make cross-cultural adaptations, and examine its psychometric properties when used by Chinese oncology nurses. Methods: After translation, the psychometric properties of the Chinese WAAQ were analyzed among 417 nurses, and content validity was determined by six experts. Results: Item-level content validity index (CVI) values were between 0.83 and 1.00; scale-level CVI/universal agreement (S-CVI/UA) and S-CVI/average were 0.86 and 0.98, respectively, which implicated a good content validity. The correlation of the Chinese WAAQ with AAQ-II (rs = −0.247, P < 0.001) suggested criterion validity, and those with General Health Questionnaire-12 (−0.250, <0.001) and general self-efficacy scale (0.491, <0.001) and Utrecht work engagement scale (UWES) (0.439, <0.001) suggested convergent validity. Exploratory factor analysis identified a seven-item, one-factor structure of WAAQ. The Chinese version of WAAQ had high internal consistency (Cronbach's α = 0.920), with an item-total correlation coefficient of 0.702–0.828 (P < 0.05), split-half reliability of 0.933, and test-retest reliability of 0.772. Conclusions: The Chinese WAAQ is a reliable and valid tool for assessing psychological flexibility in Chinese oncology nurses. PMID:29379839
Henry, Julie D; Crawford, John R
2005-06-01
To test the construct validity of the short-form version of the Depression anxiety and stress scale (DASS-21), and in particular, to assess whether stress as indexed by this measure is synonymous with negative affectivity (NA) or whether it represents a related, but distinct, construct. To provide normative data for the general adult population. Cross-sectional, correlational and confirmatory factor analysis (CFA). The DASS-21 was administered to a non-clinical sample, broadly representative of the general adult UK population (N = 1,794). Competing models of the latent structure of the DASS-21 were evaluated using CFA. The model with optimal fit (RCFI = 0.94) had a quadripartite structure, and consisted of a general factor of psychological distress plus orthogonal specific factors of depression, anxiety, and stress. This model was a significantly better fit than a competing model that tested the possibility that the Stress scale simply measures NA. The DASS-21 subscales can validly be used to measure the dimensions of depression, anxiety, and stress. However, each of these subscales also taps a more general dimension of psychological distress or NA. The utility of the measure is enhanced by the provision of normative data based on a large sample.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bernard, David; Leconte, Pierre; Destouches, Christophe
2015-07-01
Two recent papers justified a new experimental program to give a new basis for the validation of {sup 238}U nuclear data, namely neutron induced inelastic scattering and transport codes at neutron fission energies. The general idea is to perform a neutron transmission experiment through natural uranium material. As shown by Hans Bethe, neutron transmissions measured by dosimetric responses are linked to inelastic cross sections. This paper describes the principle and the results of such an experience called EXCALIBUR performed recently (January and October 2014) at the CALIBAN reactor facility. (authors)
Measuring Cross-Cultural Supernatural Beliefs with Self- and Peer-Reports.
Bluemke, Matthias; Jong, Jonathan; Grevenstein, Dennis; Mikloušić, Igor; Halberstadt, Jamin
2016-01-01
Despite claims about the universality of religious belief, whether religiosity scales have the same meaning when administered inter-subjectively-or translated and applied cross-culturally-is currently unknown. Using the recent "Supernatural Belief Scale" (SBS), we present a primer on how to verify the strong assumptions of measurement invariance required in research on religion. A comparison of two independent samples, Croatians and New Zealanders, showed that, despite a sophisticated psychometric model, measurement invariance could be demonstrated for the SBS except for two noninvariant intercepts. We present a new approach for inspecting measurement invariance across self- and peer-reports as two dependent samples. Although supernatural beliefs may be hard to observe in others, the measurement model was fully invariant for Croatians and their nominated peers. The results not only establish, for the first time, a valid measure of religious supernatural belief across two groups of different language and culture, but also demonstrate a general invariance test for distinguishable dyad members nested within the same targets. More effort needs to be made to design and validate cross-culturally applicable measures of religiosity.
Measuring Cross-Cultural Supernatural Beliefs with Self- and Peer-Reports
Bluemke, Matthias; Jong, Jonathan; Grevenstein, Dennis; Mikloušić, Igor; Halberstadt, Jamin
2016-01-01
Despite claims about the universality of religious belief, whether religiosity scales have the same meaning when administered inter-subjectively–or translated and applied cross-culturally–is currently unknown. Using the recent “Supernatural Belief Scale” (SBS), we present a primer on how to verify the strong assumptions of measurement invariance required in research on religion. A comparison of two independent samples, Croatians and New Zealanders, showed that, despite a sophisticated psychometric model, measurement invariance could be demonstrated for the SBS except for two noninvariant intercepts. We present a new approach for inspecting measurement invariance across self- and peer-reports as two dependent samples. Although supernatural beliefs may be hard to observe in others, the measurement model was fully invariant for Croatians and their nominated peers. The results not only establish, for the first time, a valid measure of religious supernatural belief across two groups of different language and culture, but also demonstrate a general invariance test for distinguishable dyad members nested within the same targets. More effort needs to be made to design and validate cross-culturally applicable measures of religiosity. PMID:27760206
Higgs boson gluon-fusion production beyond threshold in N 3LO QCD
Anastasiou, Charalampos; Duhr, Claude; Dulat, Falko; ...
2015-03-18
In this study, we compute the gluon fusion Higgs boson cross-section at N 3LO through the second term in the threshold expansion. This calculation constitutes a major milestone towards the full N 3LO cross section. Our result has the best formal accuracy in the threshold expansion currently available, and includes contributions from collinear regions besides subleading corrections from soft and hard regions, as well as certain logarithmically enhanced contributions for general kinematics. We use our results to perform a critical appraisal of the validity of the threshold approximation at N 3LO in perturbative QCD.
Burgansky-Eliash, Zvia; Wollstein, Gadi; Chu, Tianjiao; Ramsey, Joseph D.; Glymour, Clark; Noecker, Robert J.; Ishikawa, Hiroshi; Schuman, Joel S.
2007-01-01
Purpose Machine-learning classifiers are trained computerized systems with the ability to detect the relationship between multiple input parameters and a diagnosis. The present study investigated whether the use of machine-learning classifiers improves optical coherence tomography (OCT) glaucoma detection. Methods Forty-seven patients with glaucoma (47 eyes) and 42 healthy subjects (42 eyes) were included in this cross-sectional study. Of the glaucoma patients, 27 had early disease (visual field mean deviation [MD] ≥ −6 dB) and 20 had advanced glaucoma (MD < −6 dB). Machine-learning classifiers were trained to discriminate between glaucomatous and healthy eyes using parameters derived from OCT output. The classifiers were trained with all 38 parameters as well as with only 8 parameters that correlated best with the visual field MD. Five classifiers were tested: linear discriminant analysis, support vector machine, recursive partitioning and regression tree, generalized linear model, and generalized additive model. For the last two classifiers, a backward feature selection was used to find the minimal number of parameters that resulted in the best and most simple prediction. The cross-validated receiver operating characteristic (ROC) curve and accuracies were calculated. Results The largest area under the ROC curve (AROC) for glaucoma detection was achieved with the support vector machine using eight parameters (0.981). The sensitivity at 80% and 95% specificity was 97.9% and 92.5%, respectively. This classifier also performed best when judged by cross-validated accuracy (0.966). The best classification between early glaucoma and advanced glaucoma was obtained with the generalized additive model using only three parameters (AROC = 0.854). Conclusions Automated machine classifiers of OCT data might be useful for enhancing the utility of this technology for detecting glaucomatous abnormality. PMID:16249492
Amuzu-Aweh, E N; Bijma, P; Kinghorn, B P; Vereijken, A; Visscher, J; van Arendonk, J Am; Bovenhuis, H
2013-12-01
Prediction of heterosis has a long history with mixed success, partly due to low numbers of genetic markers and/or small data sets. We investigated the prediction of heterosis for egg number, egg weight and survival days in domestic white Leghorns, using ∼400 000 individuals from 47 crosses and allele frequencies on ∼53 000 genome-wide single nucleotide polymorphisms (SNPs). When heterosis is due to dominance, and dominance effects are independent of allele frequencies, heterosis is proportional to the squared difference in allele frequency (SDAF) between parental pure lines (not necessarily homozygous). Under these assumptions, a linear model including regression on SDAF partitions crossbred phenotypes into pure-line values and heterosis, even without pure-line phenotypes. We therefore used models where phenotypes of crossbreds were regressed on the SDAF between parental lines. Accuracy of prediction was determined using leave-one-out cross-validation. SDAF predicted heterosis for egg number and weight with an accuracy of ∼0.5, but did not predict heterosis for survival days. Heterosis predictions allowed preselection of pure lines before field-testing, saving ∼50% of field-testing cost with only 4% loss in heterosis. Accuracies from cross-validation were lower than from the model-fit, suggesting that accuracies previously reported in literature are overestimated. Cross-validation also indicated that dominance cannot fully explain heterosis. Nevertheless, the dominance model had considerable accuracy, clearly greater than that of a general/specific combining ability model. This work also showed that heterosis can be modelled even when pure-line phenotypes are unavailable. We concluded that SDAF is a useful predictor of heterosis in commercial layer breeding.
Paap, Kenneth R.; Sawi, Oliver
2014-01-01
A sample of 58 bilingual and 62 monolingual university students completed four tasks commonly used to test for bilingual advantages in executive functioning (EF): antisaccade, attentional network test, Simon, and color-shape switching. Across the four tasks, 13 different indices were derived that are assumed to reflect individual differences in inhibitory control, monitoring, or switching. The effects of bilingualism on the 13 measures were explored by directly comparing the means of the two language groups and through regression analyses using a continuous measure of bilingualism and multiple demographic characteristics as predictors. Across the 13 different measures and two types of data analysis there were very few significant results and those that did occur supported a monolingual advantage. An equally important goal was to assess the convergent validity through cross-task correlations of indices assume to measure the same component of executive functioning. Most of the correlations using difference-score measures were non-significant and many near zero. Although modestly higher levels of convergent validity are sometimes reported, a review of the existing literature suggests that bilingual advantages (or disadvantages) may reflect task-specific differences that are unlikely to generalize to important general differences in EF. Finally, as cautioned by Salthouse, assumed measures of executive functioning may also be threatened by a lack of discriminant validity that separates individual or group differences in EF from those in general fluid intelligence or simple processing speed. PMID:25249988
NASA Technical Reports Server (NTRS)
Chlouber, Dean; O'Neill, Pat; Pollock, Jim
1990-01-01
A technique of predicting an upper bound on the rate at which single-event upsets due to ionizing radiation occur in semiconducting memory cells is described. The upper bound on the upset rate, which depends on the high-energy particle environment in earth orbit and accelerator cross-section data, is given by the product of an upper-bound linear energy-transfer spectrum and the mean cross section of the memory cell. Plots of the spectrum are given for low-inclination and polar orbits. An alternative expression for the exact upset rate is also presented. Both methods rely only on experimentally obtained cross-section data and are valid for sensitive bit regions having arbitrary shape.
The Kings Cross fire: psychological reactions.
Turner, S W; Thompson, J; Rosser, R M
1995-07-01
The psychological reactions of 50 survivors of the King's Cross fire, which hit London's underground railway system on the 18th day of November 1987, are described. Results are presented for the Impact of Event scale, the General Health Questionnaire (28-item version), the Eysenck Personality Questionnaire and a King's Cross Event Schedule. These are investigated in relation to (a) validity measures, (b) relationships between exposure and personality, and (c) spontaneous de-briefing. Two thirds of the sample had significant levels of psychological distress (meeting the "caseness" criterion on the GHQ). Both personality (neuroticism and L-scale) and degree of trauma exposure were related to subsequent reaction. Spontaneous debriefing was associated with subjective benefit. Transportation disasters present particular problems in relation to research and service delivery.
Development and Validation of Personality Disorder Spectra Scales for the MMPI-2-RF.
Sellbom, Martin; Waugh, Mark H; Hopwood, Christopher J
2018-01-01
The purpose of this study was to develop and validate a set of MMPI-2-RF (Ben-Porath & Tellegen, 2008/2011) personality disorder (PD) spectra scales. These scales could serve the purpose of assisting with DSM-5 PD diagnosis and help link categorical and dimensional conceptions of personality pathology within the MMPI-2-RF. We developed and provided initial validity results for scales corresponding to the 10 PD constructs listed in the DSM-5 using data from student, community, clinical, and correctional samples. Initial validation efforts indicated good support for criterion validity with an external PD measure as well as with dimensional personality traits included in the DSM-5 alternative model for PDs. Construct validity results using psychosocial history and therapists' ratings in a large clinical sample were generally supportive as well. Overall, these brief scales provide clinicians using MMPI-2-RF data with estimates of DSM-5 PD constructs that can support cross-model connections between categorical and dimensional assessment approaches.
Jalenques, I; Auclair, C; Roblin, J; Morand, D; Tourtauchaux, R; May, R; Vaille-Perret, E; Watts, J; Gerbaud, L; De Leo, D
2013-04-01
To cross-culturally adapt a French version of the LEIPAD, a self-administered questionnaire assessing the health-related quality of life (HRQoL) in adults aged 65 years and over living at home, and to evaluate its psychometric properties. After having translated LEIPAD in accordance with guidelines, we studied psychometric properties: reliability and construct validity-factor analysis, relationships between items and scales, internal consistency, concurrent validity with the Medical Outcome Study Short-Form 36 and known-groups validity. The results obtained in a sample of 195 elderly from the general population showed very good acceptability, with response rates superior to 93 %. Exploratory factor analysis extracted eight factors providing a multidimensionality structure with five misclassifications of items in the seven theoretical scales. Good internal consistency (Cronbach's alpha ranging from 0.73 and 0.86) and strong test-retest reliability (ICCs higher than 0.80 for six scales and 0.70 for one) were demonstrated. Concurrent validity with the SF-36 showed small to strong expected correlations. This first evaluation of the French version of LEIPAD's psychometric properties provides evidence in construct validity and reliability. It would allow HRQoL assessment in clinical and common practice, and investigators would be able to take part in national and international research projects.
NASA Astrophysics Data System (ADS)
Fraser, Barry J.; Giddings, Geoffrey J.; McRobbie, Campbell J.
The research reported in this article makes two distinctive contributions to the field of classroom environment research. First, because existing instruments are unsuitable for science laboratory classes, the Science Laboratory Environment Inventory (SLEI) was developed and validated. Second, a new Personal form of the SLEI (involving a student's perceptions of his or her own role within the class) was developed and validated in conjunction with the conventional Class form (involving a student's perceptions of the class as a whole), and its usefulness was investigated. The instrument was cross-nationally fieldtested with 5,447 students in 269 senior high school and university classes in six countries, and cross-validated with 1,594 senior high school students in 92 classes in Australia. Each SLEI scale exhibited satisfactory internal consistency reliability, discriminant validity, and factorial validity, and differentiated between the perceptions of students in different classes. A variety of applications with the new instrument furnished evidence about its usefulness and revealed that science laboratory classes are dominated by closed-ended activities; mean scores obtained on the Class form were consistently somewhat more favorable than on the corresponding Personal form; females generally held more favorable perceptions than males, but these differences were somewhat larger for the Personal form than the Class form; associations existed between attitudinal outcomes and laboratory environment dimensions; and the Class and Personal forms of the SLEI each accounted for unique variance in student outcomes which was independent of that accounted for by the other form.
Efficient strategies for leave-one-out cross validation for genomic best linear unbiased prediction.
Cheng, Hao; Garrick, Dorian J; Fernando, Rohan L
2017-01-01
A random multiple-regression model that simultaneously fit all allele substitution effects for additive markers or haplotypes as uncorrelated random effects was proposed for Best Linear Unbiased Prediction, using whole-genome data. Leave-one-out cross validation can be used to quantify the predictive ability of a statistical model. Naive application of Leave-one-out cross validation is computationally intensive because the training and validation analyses need to be repeated n times, once for each observation. Efficient Leave-one-out cross validation strategies are presented here, requiring little more effort than a single analysis. Efficient Leave-one-out cross validation strategies is 786 times faster than the naive application for a simulated dataset with 1,000 observations and 10,000 markers and 99 times faster with 1,000 observations and 100 markers. These efficiencies relative to the naive approach using the same model will increase with increases in the number of observations. Efficient Leave-one-out cross validation strategies are presented here, requiring little more effort than a single analysis.
Junkes, Monica C; Fraiz, Fabian C; Sardenberg, Fernanda; Lee, Jessica Y; Paiva, Saul M; Ferreira, Fernanda M
2015-01-01
The aim of the present study was to translate, perform the cross-cultural adaptation of the Rapid Estimate of Adult Literacy in Dentistry to Brazilian-Portuguese language and test the reliability and validity of this version. After translation and cross-cultural adaptation, interviews were conducted with 258 parents/caregivers of children in treatment at the pediatric dentistry clinics and health units in Curitiba, Brazil. To test the instrument's validity, the scores of Brazilian Rapid Estimate of Adult Literacy in Dentistry (BREALD-30) were compared based on occupation, monthly household income, educational attainment, general literacy, use of dental services and three dental outcomes. The BREALD-30 demonstrated good internal reliability. Cronbach's alpha ranged from 0.88 to 0.89 when words were deleted individually. The analysis of test-retest reliability revealed excellent reproducibility (intraclass correlation coefficient = 0.983 and Kappa coefficient ranging from moderate to nearly perfect). In the bivariate analysis, BREALD-30 scores were significantly correlated with the level of general literacy (rs = 0.593) and income (rs = 0.327) and significantly associated with occupation, educational attainment, use of dental services, self-rated oral health and the respondent's perception regarding his/her child's oral health. However, only the association between the BREALD-30 score and the respondent's perception regarding his/her child's oral health remained significant in the multivariate analysis. The BREALD-30 demonstrated satisfactory psychometric properties and is therefore applicable to adults in Brazil.
Junkes, Monica C.; Fraiz, Fabian C.; Sardenberg, Fernanda; Lee, Jessica Y.; Paiva, Saul M.; Ferreira, Fernanda M.
2015-01-01
Objective The aim of the present study was to translate, perform the cross-cultural adaptation of the Rapid Estimate of Adult Literacy in Dentistry to Brazilian-Portuguese language and test the reliability and validity of this version. Methods After translation and cross-cultural adaptation, interviews were conducted with 258 parents/caregivers of children in treatment at the pediatric dentistry clinics and health units in Curitiba, Brazil. To test the instrument's validity, the scores of Brazilian Rapid Estimate of Adult Literacy in Dentistry (BREALD-30) were compared based on occupation, monthly household income, educational attainment, general literacy, use of dental services and three dental outcomes. Results The BREALD-30 demonstrated good internal reliability. Cronbach’s alpha ranged from 0.88 to 0.89 when words were deleted individually. The analysis of test-retest reliability revealed excellent reproducibility (intraclass correlation coefficient = 0.983 and Kappa coefficient ranging from moderate to nearly perfect). In the bivariate analysis, BREALD-30 scores were significantly correlated with the level of general literacy (rs = 0.593) and income (rs = 0.327) and significantly associated with occupation, educational attainment, use of dental services, self-rated oral health and the respondent’s perception regarding his/her child's oral health. However, only the association between the BREALD-30 score and the respondent’s perception regarding his/her child's oral health remained significant in the multivariate analysis. Conclusion The BREALD-30 demonstrated satisfactory psychometric properties and is therefore applicable to adults in Brazil. PMID:26158724
Strong-potential Born calculations for 1s-1s electron capture from atoms by protons
DOE Office of Scientific and Technical Information (OSTI.GOV)
McGuire, J.H.; Kletke, R.E.; Sil, N.C.
1985-08-01
The strong-potential Born (SPB) approximation is examined by comparing various SPB calculations of high-velocity 1s-1s electron capture cross sections with one another and with experimental data. Above about 1 MeV, calculations using the SPB method of McGuire and Sil (SPMS) (Phys. Rev. A 28, 3679 (1983)) are in good agreement with total-cross-section observations for protons on H, He, C, Ne, and Ar as expected. For p+H and p+He, the SPB full-peaking (SPB-FP) approximation of Macek and Alston (Phys. Rev. A 26, 250 (1982)) and the SPB transverse-peaking (SPB-TP) approximation of Alston (Phys. Rev. A 27, 2342 (1982)) differ from ourmore » SPMS total cross sections by typically a factor of 2, as expected from general validity criteria. However, the differential cross sections at very forward angles (well within the Thomas angle) are the same in SPMS, SPB-FP, and SPB-TP methods in all cases. Below 1 MeV, cross sections obtained with use of various SPB methods differ considerably from one another, placing a limit of validity for these SPB calculations. We also suggest that in the gap between those energies where continuum intermediate states simply dominate, and above those energies where bound intermediate states simply dominate, detailed conceptual understanding of electron capture is incomplete.« less
Dikken, Jeroen; Hoogerduijn, Jita G; Kruitwagen, Cas; Schuurmans, Marieke J
2016-11-01
To assess the content validity and psychometric characteristics of the Knowledge about Older Patients Quiz (KOP-Q), which measures nurses' knowledge regarding older hospitalized adults and their certainty regarding this knowledge. Cross-sectional. Content validity: general hospitals. Psychometric characteristics: nursing school and general hospitals in the Netherlands. Content validity: 12 nurse specialists in geriatrics. Psychometric characteristics: 107 first-year and 78 final-year bachelor of nursing students, 148 registered nurses, and 20 nurse specialists in geriatrics. Content validity: The nurse specialists rated each item of the initial KOP-Q (52 items) on relevance. Ratings were used to calculate Item-Content Validity Index and average Scale-Content Validity Index (S-CVI/ave) scores. Items with insufficient content validity were removed. Psychometric characteristics: Ratings of students, nurses, and nurse specialists were used to test for different item functioning (DIF) and unidimensionality before item characteristics (discrimination and difficulty) were examined using Item Response Theory. Finally, norm references were calculated and nomological validity was assessed. Content validity: Forty-three items remained after assessing content validity (S-CVI/ave = 0.90). Psychometric characteristics: Of the 43 items, two demonstrating ceiling effects and 11 distorting ability estimates (DIF) were subsequently excluded. Item characteristics were assessed for the remaining 30 items, all of which demonstrated good discrimination and difficulty parameters. Knowledge was positively correlated with certainty about this knowledge. The final 30-item KOP-Q is a valid, psychometrically sound, comprehensive instrument that can be used to assess the knowledge of nursing students, hospital nurses, and nurse specialists in geriatrics regarding older hospitalized adults. It can identify knowledge and certainty deficits for research purposes or serve as a tool in educational or quality improvement programs. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.
A General Cross-Layer Cloud Scheduling Framework for Multiple IoT Computer Tasks.
Wu, Guanlin; Bao, Weidong; Zhu, Xiaomin; Zhang, Xiongtao
2018-05-23
The diversity of IoT services and applications brings enormous challenges to improving the performance of multiple computer tasks' scheduling in cross-layer cloud computing systems. Unfortunately, the commonly-employed frameworks fail to adapt to the new patterns on the cross-layer cloud. To solve this issue, we design a new computer task scheduling framework for multiple IoT services in cross-layer cloud computing systems. Specifically, we first analyze the features of the cross-layer cloud and computer tasks. Then, we design the scheduling framework based on the analysis and present detailed models to illustrate the procedures of using the framework. With the proposed framework, the IoT services deployed in cross-layer cloud computing systems can dynamically select suitable algorithms and use resources more effectively to finish computer tasks with different objectives. Finally, the algorithms are given based on the framework, and extensive experiments are also given to validate its effectiveness, as well as its superiority.
1983-09-01
Ciencia y Tecnologia -Mexico, by ONR under Contract No. N00014-77-C-0675, and by ARO under Contract No. DAAG29-80-K-0042. LUJ THE VIE~W, rTIJ. ’~v ’’~c...Department of Statis- tics. For financial support I thank the Consejo Nacional de Ciencia y Tecnologia - Mexico, and the Department of Statistics of the
Tsang, B; Stothers, L; Macnab, A; Lazare, D; Nigro, M
2016-03-01
Validated questionnaires are increasingly the preferred method used to obtain historical information. Specialized questionnaires exist validated for patients with neurogenic disease including neurogenic bladder. Those currently available are systematically reviewed and their potential for clinical and research use are described. A systematic search via Medline and PubMed using the key terms questionnaire(s) crossed with Multiple Sclerosis (MS) and Spinal Cord Injury (SCI) for the years 1946 to January 22, 2014 inclusive. Additional articles were selected from review of references in the publications identified. Only peer reviewed articles published in English were included. 18 questionnaires exist validated for patients with neurogenic bladder; 14 related to MS, 3 for SCI, and 1 for neurogenic bladder in general; with 4 cross-validated in both MS and SCI. All 18 are validated for both male and female patients; 59% are available only in English. The domains of psychological impact and physical function are represented in 71% and 76% of questionnaires, respectively. None for the female population included elements to measure symptoms of prolapse. The last decade has seen an expansion of validated questionnaires to document bladder symptoms in neurogenic disease. Disease specific instruments are available for incorporation into the clinical setting for MS and SCI patients with neurogenic bladder. The availability of caregiver and interview options enhances suitability in clinical practice as they can be adapted to various extents of disability. Future developments should include expanded language validation to the top 10 global languages reported by the World Health Organization. © 2015 Wiley Periodicals, Inc.
INTERPRETING PHYSICAL AND BEHAVIORAL HEALTH SCORES FROM NEW WORK DISABILITY INSTRUMENTS
Marfeo, Elizabeth E.; Ni, Pengsheng; Chan, Leighton; Rasch, Elizabeth K.; McDonough, Christine M.; Brandt, Diane E.; Bogusz, Kara; Jette, Alan M.
2015-01-01
Objective To develop a system to guide interpretation of scores generated from 2 new instruments measuring work-related physical and behavioral health functioning (Work Disability – Physical Function (WD-PF) and WD – Behavioral Function (WD-BH)). Design Cross-sectional, secondary data from 3 independent samples to develop and validate the functional levels for physical and behavioral health functioning. Subjects Physical group: 999 general adult subjects, 1,017 disability applicants and 497 work-disabled subjects. Behavioral health group: 1,000 general adult subjects, 1,015 disability applicants and 476 work-disabled subjects. Methods Three-phase analytic approach including item mapping, a modified-Delphi technique, and known-groups validation analysis were used to develop and validate cut-points for functional levels within each of the WD-PF and WD-BH instrument’s scales. Results Four and 5 functional levels were developed for each of the scales in the WD-PF and WD-BH instruments. Distribution of the comparative samples was in the expected direction: the general adult samples consistently demonstrated scores at higher functional levels compared with the claimant and work-disabled samples. Conclusion Using an item-response theory-based methodology paired with a qualitative process appears to be a feasible and valid approach for translating the WD-BH and WD-PF scores into meaningful levels useful for interpreting a person’s work-related physical and behavioral health functioning. PMID:25729901
Schmidt, Stine N; Wang, Alice P; Gidley, Philip T; Wooley, Allyson H; Lotufo, Guilherme R; Burgess, Robert M; Ghosh, Upal; Fernandez, Loretta A; Mayer, Philipp
2017-09-05
The Gold Standard for determining freely dissolved concentrations (C free ) of hydrophobic organic compounds in sediment interstitial water would be in situ deployment combined with equilibrium sampling, which is generally difficult to achieve. In the present study, ex situ equilibrium sampling with multiple thicknesses of silicone and in situ pre-equilibrium sampling with low density polyethylene (LDPE) loaded with performance reference compounds were applied independently to measure polychlorinated biphenyls (PCBs) in mesocosms with (1) New Bedford Harbor sediment (MA, U.S.A.), (2) sediment and biota, and (3) activated carbon amended sediment and biota. The aim was to cross validate the two different sampling approaches. Around 100 PCB congeners were quantified in the two sampling polymers, and the results confirmed the good precision of both methods and were in overall good agreement with recently published LDPE to silicone partition ratios. Further, the methods yielded C free in good agreement for all three experiments. The average ratio between C free determined by the two methods was factor 1.4 ± 0.3 (range: 0.6-2.0), and the results thus cross-validated the two sampling approaches. For future investigations, specific aims and requirements in terms of application, data treatment, and data quality requirements should dictate the selection of the most appropriate partitioning-based sampling approach.
Muscle synergies during bench press are reliable across days.
Kristiansen, Mathias; Samani, Afshin; Madeleine, Pascal; Hansen, Ernst Albin
2016-10-01
Muscle synergies have been investigated during different types of human movement using nonnegative matrix factorization. However, there are not any reports available on the reliability of the method. To evaluate between-day reliability, 21 subjects performed bench press, in two test sessions separated by approximately 7days. The movement consisted of 3 sets of 8 repetitions at 60% of the three repetition maximum in bench press. Muscle synergies were extracted from electromyography data of 13 muscles, using nonnegative matrix factorization. To evaluate between-day reliability, we performed a cross-correlation analysis and a cross-validation analysis, in which the synergy components extracted in the first test session were recomputed, using the fixed synergy components from the second test session. Two muscle synergies accounted for >90% of the total variance, and reflected the concentric and eccentric phase, respectively. The cross-correlation values were strong to very strong (r-values between 0.58 and 0.89), while the cross-validation values ranged from substantial to almost perfect (ICC3, 1 values between 0.70 and 0.95). The present findings revealed that the same general structure of the muscle synergies was present across days and the extraction of muscle synergies is thus deemed reliable. Copyright © 2016 Elsevier Ltd. All rights reserved.
Kumar, Y Kiran; Mehta, Shashi Bhushan; Ramachandra, Manjunath
2017-01-01
The purpose of this work is to provide some validation methods for evaluating the hemodynamic assessment of Cerebral Arteriovenous Malformation (CAVM). This article emphasizes the importance of validating noninvasive measurements for CAVM patients, which are designed using lumped models for complex vessel structure. The validation of the hemodynamics assessment is based on invasive clinical measurements and cross-validation techniques with the Philips proprietary validated software's Qflow and 2D Perfursion. The modeling results are validated for 30 CAVM patients for 150 vessel locations. Mean flow, diameter, and pressure were compared between modeling results and with clinical/cross validation measurements, using an independent two-tailed Student t test. Exponential regression analysis was used to assess the relationship between blood flow, vessel diameter, and pressure between them. Univariate analysis is used to assess the relationship between vessel diameter, vessel cross-sectional area, AVM volume, AVM pressure, and AVM flow results were performed with linear or exponential regression. Modeling results were compared with clinical measurements from vessel locations of cerebral regions. Also, the model is cross validated with Philips proprietary validated software's Qflow and 2D Perfursion. Our results shows that modeling results and clinical results are nearly matching with a small deviation. In this article, we have validated our modeling results with clinical measurements. The new approach for cross-validation is proposed by demonstrating the accuracy of our results with a validated product in a clinical environment.
Cascade Back-Propagation Learning in Neural Networks
NASA Technical Reports Server (NTRS)
Duong, Tuan A.
2003-01-01
The cascade back-propagation (CBP) algorithm is the basis of a conceptual design for accelerating learning in artificial neural networks. The neural networks would be implemented as analog very-large-scale integrated (VLSI) circuits, and circuits to implement the CBP algorithm would be fabricated on the same VLSI circuit chips with the neural networks. Heretofore, artificial neural networks have learned slowly because it has been necessary to train them via software, for lack of a good on-chip learning technique. The CBP algorithm is an on-chip technique that provides for continuous learning in real time. Artificial neural networks are trained by example: A network is presented with training inputs for which the correct outputs are known, and the algorithm strives to adjust the weights of synaptic connections in the network to make the actual outputs approach the correct outputs. The input data are generally divided into three parts. Two of the parts, called the "training" and "cross-validation" sets, respectively, must be such that the corresponding input/output pairs are known. During training, the cross-validation set enables verification of the status of the input-to-output transformation learned by the network to avoid over-learning. The third part of the data, termed the "test" set, consists of the inputs that are required to be transformed into outputs; this set may or may not include the training set and/or the cross-validation set. Proposed neural-network circuitry for on-chip learning would be divided into two distinct networks; one for training and one for validation. Both networks would share the same synaptic weights.
Creating Cross-disciplinary Courses.
Reynolds, Elaine R
2012-01-01
Because of its focus on the biological underpinnings of action and behavior, neuroscience intersects with many fields of human endeavor. Some of these cross-disciplinary intersections have been long standing, while others, such as neurotheology or neuroeconomics, are more recently formed fields. Many undergraduate institutions have sought to include cross-disciplinary courses in their curriculum because this style of pedagogy is often seen as applicable to real world problems. However, it can be difficult for faculty with specialized training within their discipline to expand beyond their own fields to offer cross-disciplinary courses. I have been creating a series of multi- or cross-disciplinary courses and have found some strategies that have helped me successfully teach these classes. I will discuss general strategies and tools in developing these types of courses including: 1) creating mixed experience classrooms of students and contributing faculty 2) finding the right tools that will allow you to teach to a mixed population without prerequisites 3) examining the topic using multiple disciplinary perspectives 4) feeding off student experience and interest 5) assessing the impact of these courses on student outcomes and your neuroscience program. This last tool in particular is important in establishing the validity of this type of teaching for neuroscience students and the general student population.
Creating Cross-disciplinary Courses
Reynolds, Elaine R.
2012-01-01
Because of its focus on the biological underpinnings of action and behavior, neuroscience intersects with many fields of human endeavor. Some of these cross-disciplinary intersections have been long standing, while others, such as neurotheology or neuroeconomics, are more recently formed fields. Many undergraduate institutions have sought to include cross-disciplinary courses in their curriculum because this style of pedagogy is often seen as applicable to real world problems. However, it can be difficult for faculty with specialized training within their discipline to expand beyond their own fields to offer cross-disciplinary courses. I have been creating a series of multi- or cross-disciplinary courses and have found some strategies that have helped me successfully teach these classes. I will discuss general strategies and tools in developing these types of courses including: 1) creating mixed experience classrooms of students and contributing faculty 2) finding the right tools that will allow you to teach to a mixed population without prerequisites 3) examining the topic using multiple disciplinary perspectives 4) feeding off student experience and interest 5) assessing the impact of these courses on student outcomes and your neuroscience program. This last tool in particular is important in establishing the validity of this type of teaching for neuroscience students and the general student population. PMID:23494491
Gobbi, Erica; Elliot, Catherine; Varnier, Maurizio; Carraro, Attilio
2016-01-01
The purpose of this research was to assess an Italian version of the Physical Activity Questionnaire for Older Children (PAQ-C-It). Three separate studies were conducted, whereby testing general psychometric properties, construct validity, concurrent validity and the factor structure of the PAQ-C-It among general and clinical pediatric population. Study 1 (n = 1170) examined the psychometric properties, internal consistency, factor structure (exploratory factor analysis, EFA) and construct validity with enjoyment perception during physical activity. Study 2 (n = 59) reported on reliability, construct validity with enjoyment and BMI, and on cross-sectional concurrent validity with objectively measured MVPA (tri-axial accelerometry) over the span of seven consecutive days. Study 3 (n = 58) examined the PAQ-C-It reliability, construct validity with BMI and VO2max as the objective measurement among a population of children with congenital heart defects (CHD). In study 2 and 3, the factor structure of the PAQ-C-It was then re-examined with an EFA. The PAQ-C-It showed acceptable to good reliability (alpha .70 to .83). Results on construct validity showed moderate but significant association with enjoyment perception (r = .30 and .36), with BMI (r = -.30 and -.79 for CHD simple form), and with the VO2max (r = .55 for CHD simple form). Significant concurrent validity with the objectively measured MVPA was reported (rho = .30, p < .05). Findings of the EFA suggested a two-factor structure for the PAQ-C-It, with items 2, 3, and 4 contributing little to the total score. This study supports the PAQ-C-It as an appropriate instrument to assess the MVPA levels of Italian children, including children with simple forms of CHD. Support is given to the possible instrument effectiveness on a large international perspective in order to level out data gathering across the globe.
Gobbi, Erica; Elliot, Catherine; Varnier, Maurizio; Carraro, Attilio
2016-01-01
The purpose of this research was to assess an Italian version of the Physical Activity Questionnaire for Older Children (PAQ-C-It). Three separate studies were conducted, whereby testing general psychometric properties, construct validity, concurrent validity and the factor structure of the PAQ-C-It among general and clinical pediatric population. Study 1 (n = 1170) examined the psychometric properties, internal consistency, factor structure (exploratory factor analysis, EFA) and construct validity with enjoyment perception during physical activity. Study 2 (n = 59) reported on reliability, construct validity with enjoyment and BMI, and on cross-sectional concurrent validity with objectively measured MVPA (tri-axial accelerometry) over the span of seven consecutive days. Study 3 (n = 58) examined the PAQ-C-It reliability, construct validity with BMI and VO2max as the objective measurement among a population of children with congenital heart defects (CHD). In study 2 and 3, the factor structure of the PAQ-C-It was then re-examined with an EFA. The PAQ-C-It showed acceptable to good reliability (alpha .70 to .83). Results on construct validity showed moderate but significant association with enjoyment perception (r = .30 and .36), with BMI (r = -.30 and -.79 for CHD simple form), and with the VO2max (r = .55 for CHD simple form). Significant concurrent validity with the objectively measured MVPA was reported (rho = .30, p < .05). Findings of the EFA suggested a two-factor structure for the PAQ-C-It, with items 2, 3, and 4 contributing little to the total score. This study supports the PAQ-C-It as an appropriate instrument to assess the MVPA levels of Italian children, including children with simple forms of CHD. Support is given to the possible instrument effectiveness on a large international perspective in order to level out data gathering across the globe. PMID:27228050
NASA Astrophysics Data System (ADS)
Reynders, Edwin P. B.; Langley, Robin S.
2018-08-01
The hybrid deterministic-statistical energy analysis method has proven to be a versatile framework for modeling built-up vibro-acoustic systems. The stiff system components are modeled deterministically, e.g., using the finite element method, while the wave fields in the flexible components are modeled as diffuse. In the present paper, the hybrid method is extended such that not only the ensemble mean and variance of the harmonic system response can be computed, but also of the band-averaged system response. This variance represents the uncertainty that is due to the assumption of a diffuse field in the flexible components of the hybrid system. The developments start with a cross-frequency generalization of the reciprocity relationship between the total energy in a diffuse field and the cross spectrum of the blocked reverberant loading at the boundaries of that field. By making extensive use of this generalization in a first-order perturbation analysis, explicit expressions are derived for the cross-frequency and band-averaged variance of the vibrational energies in the diffuse components and for the cross-frequency and band-averaged variance of the cross spectrum of the vibro-acoustic field response of the deterministic components. These expressions are extensively validated against detailed Monte Carlo analyses of coupled plate systems in which diffuse fields are simulated by randomly distributing small point masses across the flexible components, and good agreement is found.
Stanifer, John W.; Karia, Francis; Voils, Corrine I.; Turner, Elizabeth L.; Maro, Venance; Shimbi, Dionis; Kilawe, Humphrey; Lazaro, Matayo; Patel, Uptal D.
2015-01-01
Introduction Non-communicable diseases are a growing global burden, and structured surveys can identify critical gaps to address this epidemic. In sub-Saharan Africa, there are very few well-tested survey instruments measuring population attributes related to non-communicable diseases. To meet this need, we have developed and validated the first instrument evaluating knowledge, attitudes and practices pertaining to chronic kidney disease in a Swahili-speaking population. Methods and Results Between December 2013 and June 2014, we conducted a four-stage, mixed-methods study among adults from the general population of northern Tanzania. In stage 1, the survey instrument was constructed in English by a group of cross-cultural experts from multiple disciplines and through content analysis of focus group discussions to ensure local significance. Following translation, in stage 2, we piloted the survey through cognitive and structured interviews, and in stage 3, in order to obtain initial evidence of reliability and construct validity, we recruited and then administered the instrument to a random sample of 606 adults. In stage 4, we conducted analyses to establish test-retest reliability and known-groups validity which was informed by thematic analysis of the qualitative data in stages 1 and 2. The final version consisted of 25 items divided into three conceptual domains: knowledge, attitudes and practices. Each item demonstrated excellent test-retest reliability with established content and construct validity. Conclusions We have developed a reliable and valid cross-cultural survey instrument designed to measure knowledge, attitudes and practices of chronic kidney disease in a Swahili-speaking population of Northern Tanzania. This instrument may be valuable for addressing gaps in non-communicable diseases care by understanding preferences regarding healthcare, formulating educational initiatives, and directing development of chronic disease management programs that incorporate chronic kidney disease across sub-Saharan Africa. PMID:25811781
Hernandez, Matthew; Aho, Johnathan M.; Habermann, Elizabeth B.; Choudhry, Asad; Morris, David; Zielinski, Martin
2016-01-01
Background Determination and reporting of disease severity in emergency general surgery (EGS) lacks standardization. Recently, the American Association for the Surgery of Trauma (AAST) proposed an anatomic severity grading system. We aimed to validate this system in patients with appendicitis, and determine if cross sectional imaging correlates with disease severity at operation. Methods Patients 18 years or older undergoing treatment for acute appendicitis between 2013 and 2015 were identified. Baseline demographics, procedure types were recorded, and AAST grades were assigned based on intraoperative and radiologic findings. Outcomes including length of stay, 30 day mortality, and complications based on Clavien-Dindo categories and National Surgical Quality Improvement Program variables. Summary statistical univariate, nominal logistic and standard least squares analyses were performed comparing AAST grade with key outcomes. Bland-Altman analysis compared operative findings to preoperative cross sectional imaging to compare assigning grades. Results 334 patients with mean (±SD) age of 39.3 years (±16.5) were included (53% male) and all patients had cross sectional imaging. 299 underwent appendectomy, and 85% completed laparoscopic. 30 day mortality rate was 0.9%, complication rate 21%. Increased median [IQR] AAST grade was recorded in patients with complications 2 [1-4] compared to those without 1 [1-1], p=0.001. For operative management, a median [IQR] AAST grades were significantly associated with procedure type: laparoscopic 1 [1-1], open 4 [2-5] conversion to open 3 [1-4], p=0.001. Increased median [IQR] AAST grades were significantly associated in non-operative management: patients having a complication had a higher median AAST grade of 4 [3-5], compared to those without 3 [2-3], p=0.001. Bland Altman analysis comparing AAST grade and cross sectional imaging demonstrated no difference; −0.02 ±0.02 p = 0.2 coefficient of repeatability 0.9. Conclusions The AAST grading system is valid in our population. Increased AAST grade is associated with open procedures, complications, and length of stay. AAST EGS grade determined by preoperative imaging strongly correlated to operative findings. PMID:27805996
A scaling law for accretion zone sizes
NASA Technical Reports Server (NTRS)
Greenzweig, Yuval; Lissauer, Jack J.
1987-01-01
Current theories of runaway planetary accretion require small random velocities of the accreted particles. Two body gravitational accretion cross sections which ignore tidal perturbations of the Sun are not valid for the slow encounters which occur at low relative velocities. Wetherill and Cox have studied accretion cross sections for rocky protoplanets orbiting at 1 AU. Using analytic methods based on Hill's lunar theory, one can scale these results for protoplanets that occupy the same fraction of their Hill sphere as does a rocky body at 1 AU. Generalization to bodies of different sizes is achieved here by numerical integrations of the three-body problem. Starting at initial positions far from the accreting body, test particles are allowed to encounter the body once, and the cross section is computed. A power law is found relating the cross section to the radius of the accreting body (of fixed mass).
Long Wave Runup in Asymmetric Bays and in Fjords With Two Separate Heads
NASA Astrophysics Data System (ADS)
Raz, Amir; Nicolsky, Dmitry; Rybkin, Alexei; Pelinovsky, Efim
2018-03-01
Modeling of tsunamis in glacial fjords prompts us to evaluate applicability of the cross-sectionally averaged nonlinear shallow water equations to model propagation and runup of long waves in asymmetrical bays and also in fjords with two heads. We utilize the Tuck-Hwang transformation, initially introduced for the plane beaches and currently generalized for bays with arbitrary cross section, to transform the nonlinear governing equations into a linear equation. The solution of the linearized equation describing the runup at the shore line is computed by taking into account the incident wave at the toe of the last sloping segment. We verify our predictions against direct numerical simulation of the 2-D shallow water equations and show that our solution is valid both for bays with an asymmetric L-shaped cross section, and for fjords with two heads—bays with a W-shaped cross section.
Double Cross-Validation in Multiple Regression: A Method of Estimating the Stability of Results.
ERIC Educational Resources Information Center
Rowell, R. Kevin
In multiple regression analysis, where resulting predictive equation effectiveness is subject to shrinkage, it is especially important to evaluate result replicability. Double cross-validation is an empirical method by which an estimate of invariance or stability can be obtained from research data. A procedure for double cross-validation is…
ERIC Educational Resources Information Center
Benítez, Isabel; Padilla, José-Luis
2014-01-01
Differential item functioning (DIF) can undermine the validity of cross-lingual comparisons. While a lot of efficient statistics for detecting DIF are available, few general findings have been found to explain DIF results. The objective of the article was to study DIF sources by using a mixed method design. The design involves a quantitative phase…
A Data Mining Approach for Acoustic Diagnosis of Cardiopulmonary Disease
2008-06-01
chocolate chip cookies are amazing! This thesis was prepared at The Charles Stark Draper Laboratory, Inc., under Internal Company Research Project 21796...very expensive to perform. New medical technology has been the primary cause for the rising health care costs and insurance premiums. There are two...empirical risk minimization ( ERM ) principle. Generalization error can be minimized by using cross validation to select the best parameters for the
ERIC Educational Resources Information Center
Acar, Tu¨lin
2014-01-01
In literature, it has been observed that many enhanced criteria are limited by factor analysis techniques. Besides examinations of statistical structure and/or psychological structure, such validity studies as cross validation and classification-sequencing studies should be performed frequently. The purpose of this study is to examine cross…
The computation of Laplacian smoothing splines with examples
NASA Technical Reports Server (NTRS)
Wendelberger, J. G.
1982-01-01
Laplacian smoothing splines (LSS) are presented as generalizations of graduation, cubic and thin plate splines. The method of generalized cross validation (GCV) to choose the smoothing parameter is described. The GCV is used in the algorithm for the computation of LSS's. An outline of a computer program which implements this algorithm is presented along with a description of the use of the program. Examples in one, two and three dimensions demonstrate how to obtain estimates of function values with confidence intervals and estimates of first and second derivatives. Probability plots are used as a diagnostic tool to check for model inadequacy.
Lectures on the scattering of light. [by dielectric sphere
NASA Technical Reports Server (NTRS)
Saxon, D. S.
1974-01-01
The exact (Mie) theory for the scattering of a plane wave by a dielectric sphere is presented. Since this infinite series solution is computationally impractical for large spheres, another formulation is given in terms of an integral equation valid for a bounded, but otherwise general array of scatterers. This equation is applied to the scattering by a single sphere, and several methods are suggested for approximating the scattering cross section in closed form. A tensor scattering matrix is introduced, in terms of which some general scattering theorems are derived. The application of the formalism to multiple scattering is briefly considered.
Leite, Priscilla; Rangé, Bernard; Kukar-Kiney, Monika; Ridgway, Nancy; Monroe, Kent; Ribas Junior, Rodolfo; Landeira Fernandez, J; Nardi, Antonio Egidio; Silva, Adriana
2013-03-01
To present the process of transcultural adaptation of the Richmond Compulsive Buying Scale to Brazilian Portuguese. For the semantic adaptation step, the scale was translated to Portuguese and then back-translated to English by two professional translators and one psychologist, without any communication between them. The scale was then applied to 20 participants from the general population for language adjustments. For the construct validation step, an exploratory factor analysis was performed, using the scree plot test, principal component analysis for factor extraction, and Varimax rotation. For convergent validity, the correlation matrix was analyzed through Pearson's coefficient. The scale showed easy applicability, satisfactory internal consistency (Cronbach's alpha=.87), and a high correlation with other rating scales for compulsive buying disorder, indicating that it is suitable to be used in the assessment and diagnosis of compulsive buying disorder, as it presents psychometric validity. The Brazilian Portuguese version of the Richmond Compulsive Buying Scale has good validity and reliability.
Abma, Femke I; van der Klink, Jac J L; Bültmann, Ute
2013-03-01
The promotion of a sustainable, healthy and productive working life attracts more and more attention. Recently the Work Role Functioning Questionnaire (WRFQ) has been cross-culturally translated and adapted to Dutch. This questionnaire aims to measure the health-related work functioning of workers with health problems. The aim of this study is to evaluate the reliability, validity (including five new items) and responsiveness of the WRFQ 2.0 in the working population. A longitudinal study was conducted among workers. The reliability (internal consistency, test-retest reliability, measurement error), validity (structural validity-factor analysis, construct validity by means of hypotheses testing) and responsiveness of the WRFQ 2.0 were evaluated. A total of N = 553 workers completed the survey. The final WRFQ 2.0 has four subscales and showed very good internal consistency, moderate test-retest reliability, good construct validity and moderate responsiveness in the working population. The WRFQ was able to distinguish between groups with different levels of mental health, physical health, fatigue and need for recovery. A moderate correlation was found between WRFQ and related constructs respectively work ability and work productivity. A weak relationship was found with general self-rated health, work engagement and work involvement. The WRFQ 2.0 is a reliable and valid instrument to measure health-related work functioning in the working population. Further validation in larger samples is recommended, especially for test-retest reliability, responsiveness and the questionnaire's ability to predict the future course of health-related work functioning.
Lorentz violation, gravitoelectromagnetic field and Bhabha scattering
NASA Astrophysics Data System (ADS)
Santos, A. F.; Khanna, Faqir C.
2018-01-01
Lorentz symmetry is a fundamental symmetry in the Standard Model (SM) and in General Relativity (GR). This symmetry holds true for all models at low energies. However, at energies near the Planck scale, it is conjectured that there may be a very small violation of Lorentz symmetry. The Standard Model Extension (SME) is a quantum field theory that includes a systematic description of Lorentz symmetry violations in all sectors of particle physics and gravity. In this paper, SME is considered to study the physical process of Bhabha Scattering in the Gravitoelectromagnetism (GEM) theory. GEM is an important formalism that is valid in a suitable approximation of general relativity. A new nonminimal coupling term that violates Lorentz symmetry is used in this paper. Differential cross-section for gravitational Bhabha scattering is calculated. The Lorentz violation contributions to this GEM scattering cross-section are small and are similar in magnitude to the case of the electromagnetic field.
A generalized non-Gaussian consistency relation for single field inflation
NASA Astrophysics Data System (ADS)
Bravo, Rafael; Mooij, Sander; Palma, Gonzalo A.; Pradenas, Bastián
2018-05-01
We show that a perturbed inflationary spacetime, driven by a canonical single scalar field, is invariant under a special class of coordinate transformations together with a field reparametrization of the curvature perturbation in co-moving gauge. This transformation may be used to derive the squeezed limit of the 3-point correlation function of the co-moving curvature perturbations valid in the case that these do not freeze after horizon crossing. This leads to a generalized version of Maldacena's non-Gaussian consistency relation in the sense that the bispectrum squeezed limit is completely determined by spacetime diffeomorphisms. Just as in the case of the standard consistency relation, this result may be understood as the consequence of how long-wavelength modes modulate those of shorter wavelengths. This relation allows one to derive the well known violation to the consistency relation encountered in ultra slow-roll, where curvature perturbations grow exponentially after horizon crossing.
Multivariate cross-frequency coupling via generalized eigendecomposition
Cohen, Michael X
2017-01-01
This paper presents a new framework for analyzing cross-frequency coupling in multichannel electrophysiological recordings. The generalized eigendecomposition-based cross-frequency coupling framework (gedCFC) is inspired by source-separation algorithms combined with dynamics of mesoscopic neurophysiological processes. It is unaffected by factors that confound traditional CFC methods—such as non-stationarities, non-sinusoidality, and non-uniform phase angle distributions—attractive properties considering that brain activity is neither stationary nor perfectly sinusoidal. The gedCFC framework opens new opportunities for conceptualizing CFC as network interactions with diverse spatial/topographical distributions. Five specific methods within the gedCFC framework are detailed, these are validated in simulated data and applied in several empirical datasets. gedCFC accurately recovers physiologically plausible CFC patterns embedded in noise that causes traditional CFC methods to perform poorly. The paper also demonstrates that spike-field coherence in multichannel local field potential data can be analyzed using the gedCFC framework, which provides significant advantages over traditional spike-field coherence analyses. Null-hypothesis testing is also discussed. DOI: http://dx.doi.org/10.7554/eLife.21792.001 PMID:28117662
Santo, Ruth Miyuki; Ribeiro-Ferreira, Felipe; Alves, Milton Ruiz; Epstein, Jonathan; Novaes, Priscila
2015-04-01
To provide a reliable, validated, and culturally adapted instrument that may be used in monitoring dry eye in Brazilian patients and to discuss the strategies for the enhancement of the cross-cultural adaptation and validation process of a self-report measure for dry eye. The cross-cultural adaptation process (CCAP) of the original Ocular Surface Disease Index (OSDI) into Brazilian-Portuguese was conducted using a 9-step guideline. The synthesis of translations was tested twice, for face and content validity, by different subjects (focus groups and cognitive interviews). The expert committee contributed on several steps, and back translations were based on the final rather than the prefinal version. For validation, the adapted version was applied in a prospective longitudinal study to 101 patients from the Dry Eye Clinic at the General Hospital of the University of São Paulo, Brazil. Simultaneously to the OSDI, patients answered the short form-36 health survey (SF-36) and the 25-item visual function questionnaire (VFQ-25) and underwent clinical evaluation. Internal consistency, test-retest reliability, and measure validity were assessed. Cronbach's alpha value of the cross-culturally adapted Brazilian-Portuguese version of the OSDI was 0.905, and the intraclass correlation coefficient was 0.801. There was a statistically significant difference between OSDI scores in patients with dry eye (41.15 ± 27.40) and without dry eye (17.88 ± 17.09). There was a negative association between OSDI and VFQ-25 total score (P < 0.01) and between the OSDI and five SF-36 domains. OSDI scores correlated positively with lissamine green and fluorescein staining scores (P < 0.001) and negatively with Schirmer test I and tear break-up time values (P < 0.001). Although most of the reviewed guidelines on CCAP involve well-defined steps (translation, synthesis/reconciliation, back translation, expert committee review, pretesting), the proposed methodological steps have not been applied in a uniform way. The translation and adaptation process requires skill, knowledge, experience, and a considerable investment of time to maximize the attainment of semantic, idiomatic, experiential, and conceptual equivalence between the source and target questionnaires. A well-established guideline resulted in a culturally adapted Brazilian-Portuguese version of the OSDI, tested and validated on a sample of Brazilian population, and proved to be a valid and reliable instrument for assessing patients with dry eye syndrome in Brazil. Copyright © 2015 Elsevier Inc. All rights reserved.
Cross-Validating Chinese Language Mental Health Recovery Measures in Hong Kong
ERIC Educational Resources Information Center
Bola, John; Chan, Tiffany Hill Ching; Chen, Eric HY; Ng, Roger
2016-01-01
Objectives: Promoting recovery in mental health services is hampered by a shortage of reliable and valid measures, particularly in Hong Kong. We seek to cross validate two Chinese language measures of recovery and one of recovery-promoting environments. Method: A cross-sectional survey of people recovering from early episode psychosis (n = 121)…
NASA Astrophysics Data System (ADS)
Bak, S.; Smith, J. M.; Hesser, T.; Bryant, M. A.
2016-12-01
Near-coast wave models are generally validated with relatively small data sets that focus on analytical solutions, specialized experiments, or intense storms. Prior studies have compiled testbeds that include a few dozen experiments or storms to validate models (e.g., Ris et al. 2002), but few examples exist that allow for continued model evaluation in the nearshore and surf-zone in near-realtime. The limited nature of these validation sets is driven by a lack of high spatial and temporal resolution in-situ wave measurements and the difficulty in maintaining these instruments on the active profile over long periods of time. The US Army Corps of Engineers Field Research Facility (FRF) has initiated a Coastal Model Test-Bed (CMTB), which is an automated system that continually validates wave models (with morphological and circulation models to follow) utilizing the rich data set of oceanographic and bathymetric measurements collected at the FRF. The FRF's cross-shore wave array provides wave measurements along a cross-shore profile from 26 m of water depth to the shoreline, utilizing various instruments including wave-rider buoys, AWACs, aquadopps, pressure gauges, and a dune-mounted lidar (Brodie et al. 2015). This work uses the CMTB to evaluate the performance of a phase-averaged numerical wave model, STWAVE (Smith 2007, Massey et al. 2011) over the course of a year at the FRF in Duck, NC. Additionally, from the BathyDuck Experiment in October 2015, the CMTB was used to determine the impact of applying the depth boundary condition for the model from monthly acoustic bathymetric surveys in comparison to hourly estimates using a video-based inversion method (e.g., cBathy, Holman et al. 2013). The modeled wave parameters using both bathymetric boundary conditions are evaluated using the FRF's cross-shore wave array and two additional cross-shore arrays of wave measurements in 2 to 4 m water depth from BathyDuck in Fall, 2015.
Cross Validation Through Two-Dimensional Solution Surface for Cost-Sensitive SVM.
Gu, Bin; Sheng, Victor S; Tay, Keng Yeow; Romano, Walter; Li, Shuo
2017-06-01
Model selection plays an important role in cost-sensitive SVM (CS-SVM). It has been proven that the global minimum cross validation (CV) error can be efficiently computed based on the solution path for one parameter learning problems. However, it is a challenge to obtain the global minimum CV error for CS-SVM based on one-dimensional solution path and traditional grid search, because CS-SVM is with two regularization parameters. In this paper, we propose a solution and error surfaces based CV approach (CV-SES). More specifically, we first compute a two-dimensional solution surface for CS-SVM based on a bi-parameter space partition algorithm, which can fit solutions of CS-SVM for all values of both regularization parameters. Then, we compute a two-dimensional validation error surface for each CV fold, which can fit validation errors of CS-SVM for all values of both regularization parameters. Finally, we obtain the CV error surface by superposing K validation error surfaces, which can find the global minimum CV error of CS-SVM. Experiments are conducted on seven datasets for cost sensitive learning and on four datasets for imbalanced learning. Experimental results not only show that our proposed CV-SES has a better generalization ability than CS-SVM with various hybrids between grid search and solution path methods, and than recent proposed cost-sensitive hinge loss SVM with three-dimensional grid search, but also show that CV-SES uses less running time.
Blood-based protein biomarkers for diagnosis of Alzheimer disease.
Doecke, James D; Laws, Simon M; Faux, Noel G; Wilson, William; Burnham, Samantha C; Lam, Chiou-Peng; Mondal, Alinda; Bedo, Justin; Bush, Ashley I; Brown, Belinda; De Ruyck, Karl; Ellis, Kathryn A; Fowler, Christopher; Gupta, Veer B; Head, Richard; Macaulay, S Lance; Pertile, Kelly; Rowe, Christopher C; Rembach, Alan; Rodrigues, Mark; Rumble, Rebecca; Szoeke, Cassandra; Taddei, Kevin; Taddei, Tania; Trounson, Brett; Ames, David; Masters, Colin L; Martins, Ralph N
2012-10-01
To identify plasma biomarkers for the diagnosis of Alzheimer disease (AD). Baseline plasma screening of 151 multiplexed analytes combined with targeted biomarker and clinical pathology data. General community-based, prospective, longitudinal study of aging. A total of 754 healthy individuals serving as controls and 207 participants with AD from the Australian Imaging Biomarker and Lifestyle study (AIBL) cohort with identified biomarkers that were validated in 58 healthy controls and 112 individuals with AD from the Alzheimer Disease Neuroimaging Initiative (ADNI) cohort. A biomarker panel was identified that included markers significantly increased (cortisol, pancreatic polypeptide, insulinlike growth factor binding protein 2, β(2) microglobulin, vascular cell adhesion molecule 1, carcinoembryonic antigen, matrix metalloprotein 2, CD40, macrophage inflammatory protein 1α, superoxide dismutase, and homocysteine) and decreased (apolipoprotein E, epidermal growth factor receptor, hemoglobin, calcium, zinc, interleukin 17, and albumin) in AD. Cross-validated accuracy measures from the AIBL cohort reached a mean (SD) of 85% (3.0%) for sensitivity and specificity and 93% (3.0) for the area under the receiver operating characteristic curve. A second validation using the ADNI cohort attained accuracy measures of 80% (3.0%) for sensitivity and specificity and 85% (3.0) for area under the receiver operating characteristic curve. This study identified a panel of plasma biomarkers that distinguish individuals with AD from cognitively healthy control subjects with high sensitivity and specificity. Cross-validation within the AIBL cohort and further validation within the ADNI cohort provides strong evidence that the identified biomarkers are important for AD diagnosis.
Dutch translation and cross-cultural validation of the Adult Social Care Outcomes Toolkit (ASCOT).
van Leeuwen, Karen M; Bosmans, Judith E; Jansen, Aaltje Pd; Rand, Stacey E; Towers, Ann-Marie; Smith, Nick; Razik, Kamilla; Trukeschitz, Birgit; van Tulder, Maurits W; van der Horst, Henriette E; Ostelo, Raymond W
2015-05-13
The Adult Social Care Outcomes Toolkit was developed to measure outcomes of social care in England. In this study, we translated the four level self-completion version (SCT-4) of the ASCOT for use in the Netherlands and performed a cross-cultural validation. The ASCOT SCT-4 was translated into Dutch following international guidelines, including two forward and back translations. The resulting version was pilot tested among frail older adults using think-aloud interviews. Furthermore, using a subsample of the Dutch ACT-study, we investigated test-retest reliability and construct validity and compared response distributions with data from a comparable English study. The pilot tests showed that translated items were in general understood as intended, that most items were reliable, and that the response distributions of the Dutch translation and associations with other measures were comparable to the original English version. Based on the results of the pilot tests, some small modifications and a revision of the Dignity items were proposed for the final translation, which were approved by the ASCOT development team. The complete original English version and the final Dutch translation can be obtained after registration on the ASCOT website ( http://www.pssru.ac.uk/ascot ). This study provides preliminary evidence that the Dutch translation of the ASCOT is valid, reliable and comparable to the original English version. We recommend further research to confirm the validity of the modified Dutch ASCOT translation.
Can we predict 4-year graduation in podiatric medical school using admission data?
Sesodia, Sanjay; Molnar, David; Shaw, Graham P
2012-01-01
This study examined the predictive ability of educational background and demographic variables, available at the admission stage, to identify applicants who will graduate in 4 years from podiatric medical school. A logistic regression model was used to identify two predictors of 4-year graduation: age at matriculation and total Medical College Admission Test score. The model was cross-validated using a second independent sample from the same population. Cross-validation gives greater confidence that the results could be more generally applied. Total Medical College Admission Test score was the strongest predictor of 4-year graduation, with age at matriculation being a statistically significant but weaker predictor. Despite the model's capacity to predict 4-year graduation better than random assignment, a sufficient amount of error in prediction remained, suggesting that important predictors are missing from the model. Furthermore, the high rate of false-positives makes it inappropriate to use age and Medical College Admission Test score as admission screens in an attempt to eliminate attrition by not accepting at-risk students.
Empirical Performance of Cross-Validation With Oracle Methods in a Genomics Context.
Martinez, Josue G; Carroll, Raymond J; Müller, Samuel; Sampson, Joshua N; Chatterjee, Nilanjan
2011-11-01
When employing model selection methods with oracle properties such as the smoothly clipped absolute deviation (SCAD) and the Adaptive Lasso, it is typical to estimate the smoothing parameter by m-fold cross-validation, for example, m = 10. In problems where the true regression function is sparse and the signals large, such cross-validation typically works well. However, in regression modeling of genomic studies involving Single Nucleotide Polymorphisms (SNP), the true regression functions, while thought to be sparse, do not have large signals. We demonstrate empirically that in such problems, the number of selected variables using SCAD and the Adaptive Lasso, with 10-fold cross-validation, is a random variable that has considerable and surprising variation. Similar remarks apply to non-oracle methods such as the Lasso. Our study strongly questions the suitability of performing only a single run of m-fold cross-validation with any oracle method, and not just the SCAD and Adaptive Lasso.
A cross-validation package driving Netica with python
Fienen, Michael N.; Plant, Nathaniel G.
2014-01-01
Bayesian networks (BNs) are powerful tools for probabilistically simulating natural systems and emulating process models. Cross validation is a technique to avoid overfitting resulting from overly complex BNs. Overfitting reduces predictive skill. Cross-validation for BNs is known but rarely implemented due partly to a lack of software tools designed to work with available BN packages. CVNetica is open-source, written in Python, and extends the Netica software package to perform cross-validation and read, rebuild, and learn BNs from data. Insights gained from cross-validation and implications on prediction versus description are illustrated with: a data-driven oceanographic application; and a model-emulation application. These examples show that overfitting occurs when BNs become more complex than allowed by supporting data and overfitting incurs computational costs as well as causing a reduction in prediction skill. CVNetica evaluates overfitting using several complexity metrics (we used level of discretization) and its impact on performance metrics (we used skill).
Devoogdt, Nele; De Groef, An; Hendrickx, Ad; Damstra, Robert; Christiaansen, Anke; Geraerts, Inge; Vervloesem, Nele; Vergote, Ignace; Van Kampen, Marijke
2014-05-01
Patients may develop primary (congenital) or secondary (acquired) lymphedema, causing significant physical and psychosocial problems. To plan treatment for lymphedema and monitor a patient's progress, swelling, and problems in functioning associated with lymphedema development should be assessed at baseline and follow-up. The purpose of this study was to investigate the reliability (test-retest, internal consistency, and measurement variability) and validity (content and construct) of data obtained with the Lymphoedema Functioning, Disability and Health Questionnaire for Lower Limb Lymphoedema (Lymph-ICF-LL). This was a multicenter, cross-sectional study. The Lymph-ICF-LL is a descriptive, evaluative tool containing 28 questions about impairments in function, activity limitations, and participation restrictions in patients with lower limb lymphedema. The questionnaire has 5 domains: physical function, mental function, general tasks/household activities, mobility activities, and life domains/social life. The reliability and validity of the Lymph-ICF-LL were examined in 30 participants with objective lower limb lymphedema. Intraclass correlation coefficients for test-retest reliability ranged from .69 to .94, and Cronbach alpha coefficients for internal consistency ranged from .82 to .97. Measurement variability was acceptable (standard error of measurement=5.9-12.6). Content validity was good because all questions were understandable for 93% of participants, the scoring system (visual analog scale) was clear, and the questionnaire was comprehensive for 90% of participants. Construct validity was good. All hypotheses for assessing convergent validity and divergent validity were accepted. The known-groups validity and responsiveness of the Dutch Lymph-ICF-LL and the cross-cultural validity of the English version of the Lymph-ICF-LL were not investigated. The Lymph-ICF-LL is a Dutch questionnaire with evidence of reliability and validity for assessing impairments in function, activity limitations, and participation restrictions in people with primary or secondary lower limb lymphedema.
Validation of a Spanish version of the Spine Functional Index.
Cuesta-Vargas, Antonio I; Gabel, Charles P
2014-06-27
The Spine Functional Index (SFI) is a recently published, robust and clinimetrically valid patient reported outcome measure. The purpose of this study was the adaptation and validation of a Spanish-version (SFI-Sp) with cultural and linguistic equivalence. A two stage observational study was conducted. The SFI was cross-culturally adapted to Spanish through double forward and backward translation then validated for its psychometric characteristics. Participants (n = 226) with various spine conditions of >12 weeks duration completed the SFI-Sp and a region specific measure: for the back, the Roland Morris Questionnaire (RMQ) and Backache Index (BADIX); for the neck, the Neck Disability Index (NDI); for general health the EQ-5D and SF-12. The full sample was employed to determine internal consistency, concurrent criterion validity by region and health, construct validity and factor structure. A subgroup (n = 51) was used to determine reliability at seven days. The SFI-Sp demonstrated high internal consistency (α = 0.85) and reliability (r = 0.96). The factor structure was one-dimensional and supported construct validity. Criterion specific validity for function was high with the RMQ (r = 0.79), moderate with the BADIX (r = 0.59) and low with the NDI (r = 0.46). For general health it was low with the EQ-5D and inversely correlated (r = -0.42) and fair with the Physical and Mental Components of the SF-12 and inversely correlated (r = -0.56 and r = -0.48), respectively. The study limitations included the lack of longitudinal data regarding other psychometric properties, specifically responsiveness. The SFI-Sp was demonstrated as a valid and reliable spine-regional outcome measure. The psychometric properties were comparable to and supported those of the English-version, however further longitudinal investigations are required.
Cross-Validation of easyCBM Reading Cut Scores in Washington: 2009-2010. Technical Report #1109
ERIC Educational Resources Information Center
Irvin, P. Shawn; Park, Bitnara Jasmine; Anderson, Daniel; Alonzo, Julie; Tindal, Gerald
2011-01-01
This technical report presents results from a cross-validation study designed to identify optimal cut scores when using easyCBM[R] reading tests in Washington state. The cross-validation study analyzes data from the 2009-2010 academic year for easyCBM[R] reading measures. A sample of approximately 900 students per grade, randomly split into two…
Kaneko, Hiromasa; Funatsu, Kimito
2013-09-23
We propose predictive performance criteria for nonlinear regression models without cross-validation. The proposed criteria are the determination coefficient and the root-mean-square error for the midpoints between k-nearest-neighbor data points. These criteria can be used to evaluate predictive ability after the regression models are updated, whereas cross-validation cannot be performed in such a situation. The proposed method is effective and helpful in handling big data when cross-validation cannot be applied. By analyzing data from numerical simulations and quantitative structural relationships, we confirm that the proposed criteria enable the predictive ability of the nonlinear regression models to be appropriately quantified.
Muquith, Mohammed A; Islam, Md Nazrul; Haq, Syed A; Ten Klooster, Peter M; Rasker, Johannes J; Yunus, Muhammad B
2012-08-27
Currently, no validated instruments are available to measure the health status of Bangladeshi patients with fibromyalgia (FM). The aims of this study were to cross-culturally adapt the modified Fibromyalgia Impact Questionnaire (FIQ) into Bengali (B-FIQ) and to test its validity and reliability in Bangladeshi patients with FM. The FIQ was translated following cross-cultural adaptation guidelines and pretested in 30 female patients with FM. Next, the adapted B-FIQ was physician-administered to 102 consecutive female FM patients together with the Health Assessment Questionnaire (HAQ), selected subscales of the SF-36, and visual analog scales for current clinical symptoms. A tender point count (TPC) was performed by an experienced rheumatologist. Forty randomly selected patients completed the B-FIQ again after 7 days. Two control groups of 50 healthy people and 50 rheumatoid arthritis (RA) patients also completed the B-FIQ. For the final B-FIQ, five physical function sub-items were replaced with culturally appropriate equivalents. Internal consistency was adequate for both the 11-item physical function subscale (α = 0.73) and the total scale (α = 0.83). With exception of the physical function subscale, expected correlations were generally observed between the B-FIQ items and selected subscales of the SF-36, HAQ, clinical symptoms, and TPC. The B-FIQ was able to discriminate between FM patients and healthy controls and between FM patients and RA patients. Test-retest reliability was adequate for the physical function subscale (r = 0.86) and individual items (r = 0.73-0.86), except anxiety (r = 0.27) and morning tiredness (r = 0.64). This study supports the reliability and validity of the B-FIQ as a measure of functional disability and health status in Bangladeshi women with FM.
Nair, Rahul; Ishaque, Sana; Spencer, Andrew John; Luzzi, Liana; Do, Loc Giang
2018-03-30
Review the validation process reported for oral healthcare satisfaction scales that intended to measure general oral health care that is not restricted to specific subspecialties or interventions. After preliminary searches, PUBMED and EMBASE were searched using a broad search strategy, followed by a snowball strategy using the references of the publications included from database searches. Title and abstract were screened for assessing inclusion, followed by a full-text screening of these publications. English language publications on multi-item questionnaires that report on a scale measuring patient satisfaction for oral health care were included. Publications were excluded when they did not report on any psychometric validation, or the scales were addressing specific treatments or subspecialities in oral health care. Fourteen instruments were identified from as many publications that report on their initial validation, while five more publications reported on further testing of the validity of these instruments. Number of items (range: 8-42) and dimension reported (range: 2-13) were often dissimilar between the assessed measurement instruments. There was also a lack of methodologies to incorporate patient's subjective perspective. Along with a limited reporting of psychometric properties of instruments, cross-cultural adaptations were limited to translation processes. The extent of validity and reliability of the included instruments was largely unassessed, and appropriate instruments for populations outside of those belonging to general adult populations were not present. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Predicting the risk of toxic blooms of golden alga from cell abundance and environmental covariates
Patino, Reynaldo; VanLandeghem, Matthew M.; Denny, Shawn
2016-01-01
Golden alga (Prymnesium parvum) is a toxic haptophyte that has caused considerable ecological damage to marine and inland aquatic ecosystems worldwide. Studies focused primarily on laboratory cultures have indicated that toxicity is poorly correlated with the abundance of golden alga cells. This relationship, however, has not been rigorously evaluated in the field where environmental conditions are much different. The ability to predict toxicity using readily measured environmental variables and golden alga abundance would allow managers rapid assessments of ichthyotoxicity potential without laboratory bioassay confirmation, which requires additional resources to accomplish. To assess the potential utility of these relationships, several a priori models relating lethal levels of golden alga ichthyotoxicity to golden alga abundance and environmental covariates were constructed. Model parameters were estimated using archived data from four river basins in Texas and New Mexico (Colorado, Brazos, Red, Pecos). Model predictive ability was quantified using cross-validation, sensitivity, and specificity, and the relative ranking of environmental covariate models was determined by Akaike Information Criterion values and Akaike weights. Overall, abundance was a generally good predictor of ichthyotoxicity as cross validation of golden alga abundance-only models ranged from ∼ 80% to ∼ 90% (leave-one-out cross-validation). Environmental covariates improved predictions, especially the ability to predict lethally toxic events (i.e., increased sensitivity), and top-ranked environmental covariate models differed among the four basins. These associations may be useful for monitoring as well as understanding the abiotic factors that influence toxicity during blooms.
Zahoor, Hafiz; Chan, Albert P. C.; Utama, Wahyudi P.; Gao, Ran; Zafar, Irfan
2017-01-01
This study attempts to validate a safety performance (SP) measurement model in the cross-cultural setting of a developing country. In addition, it highlights the variations in investigating the relationship between safety climate (SC) factors and SP indicators. The data were collected from forty under-construction multi-storey building projects in Pakistan. Based on the results of exploratory factor analysis, a SP measurement model was hypothesized. It was tested and validated by conducting confirmatory factor analysis on calibration and validation sub-samples respectively. The study confirmed the significant positive impact of SC on safety compliance and safety participation, and negative impact on number of self-reported accidents/injuries. However, number of near-misses could not be retained in the final SP model because it attained a lower standardized path coefficient value. Moreover, instead of safety participation, safety compliance established a stronger impact on SP. The study uncovered safety enforcement and promotion as a novel SC factor, whereas safety rules and work practices was identified as the most neglected factor. The study contributed to the body of knowledge by unveiling the deviations in existing dimensions of SC and SP. The refined model is expected to concisely measure the SP in the Pakistani construction industry, however, caution must be exercised while generalizing the study results to other developing countries. PMID:28350366
Zahoor, Hafiz; Chan, Albert P C; Utama, Wahyudi P; Gao, Ran; Zafar, Irfan
2017-03-28
This study attempts to validate a safety performance (SP) measurement model in the cross-cultural setting of a developing country. In addition, it highlights the variations in investigating the relationship between safety climate (SC) factors and SP indicators. The data were collected from forty under-construction multi-storey building projects in Pakistan. Based on the results of exploratory factor analysis, a SP measurement model was hypothesized. It was tested and validated by conducting confirmatory factor analysis on calibration and validation sub-samples respectively. The study confirmed the significant positive impact of SC on safety compliance and safety participation , and negative impact on number of self-reported accidents/injuries . However, number of near-misses could not be retained in the final SP model because it attained a lower standardized path coefficient value. Moreover, instead of safety participation , safety compliance established a stronger impact on SP. The study uncovered safety enforcement and promotion as a novel SC factor, whereas safety rules and work practices was identified as the most neglected factor. The study contributed to the body of knowledge by unveiling the deviations in existing dimensions of SC and SP. The refined model is expected to concisely measure the SP in the Pakistani construction industry, however, caution must be exercised while generalizing the study results to other developing countries.
Uncertainty Quantification Techniques of SCALE/TSUNAMI
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rearden, Bradley T; Mueller, Don
2011-01-01
The Standardized Computer Analysis for Licensing Evaluation (SCALE) code system developed at Oak Ridge National Laboratory (ORNL) includes Tools for Sensitivity and Uncertainty Analysis Methodology Implementation (TSUNAMI). The TSUNAMI code suite can quantify the predicted change in system responses, such as k{sub eff}, reactivity differences, or ratios of fluxes or reaction rates, due to changes in the energy-dependent, nuclide-reaction-specific cross-section data. Where uncertainties in the neutron cross-section data are available, the sensitivity of the system to the cross-section data can be applied to propagate the uncertainties in the cross-section data to an uncertainty in the system response. Uncertainty quantification ismore » useful for identifying potential sources of computational biases and highlighting parameters important to code validation. Traditional validation techniques often examine one or more average physical parameters to characterize a system and identify applicable benchmark experiments. However, with TSUNAMI correlation coefficients are developed by propagating the uncertainties in neutron cross-section data to uncertainties in the computed responses for experiments and safety applications through sensitivity coefficients. The bias in the experiments, as a function of their correlation coefficient with the intended application, is extrapolated to predict the bias and bias uncertainty in the application through trending analysis or generalized linear least squares techniques, often referred to as 'data adjustment.' Even with advanced tools to identify benchmark experiments, analysts occasionally find that the application models include some feature or material for which adequately similar benchmark experiments do not exist to support validation. For example, a criticality safety analyst may want to take credit for the presence of fission products in spent nuclear fuel. In such cases, analysts sometimes rely on 'expert judgment' to select an additional administrative margin to account for gap in the validation data or to conclude that the impact on the calculated bias and bias uncertainty is negligible. As a result of advances in computer programs and the evolution of cross-section covariance data, analysts can use the sensitivity and uncertainty analysis tools in the TSUNAMI codes to estimate the potential impact on the application-specific bias and bias uncertainty resulting from nuclides not represented in available benchmark experiments. This paper presents the application of methods described in a companion paper.« less
Cross-Cultural Competence in the Department of Defense: An Annotated Bibliography
2014-04-01
computer toward the best possible strategy. The article outlines, in detail, how the game is played in theory as well as how it was played in this...validation of the CQS: The cultural intelligence scale. In S. Ang & L. Van Dyne (Eds.), Handbook of cultural intelligence: Theory , measurement, and...weaknesses of various approaches, general learning theory , and the utility of employing civilian style education to prepare Soldiers to interact in
E&V (Evaluation and Validation) Reference Manual, Version 1.0.
1988-07-01
references featured in the Reference Manual. G-05097a GENERAL REFERENCE INFORMATION EXTRACTED , FROM * INDEXES AND CROSS REFERENCES CHAPTER 4...at E&V techniques through many different paths, and provides a means to extract useful information along the way. /^c^^s; /r^ ^yr*•**•»» * L...electronically (preferred) to szymansk@ajpo.sei.cmu.edu or by regular mail to Mr. Raymond Szymanski . AFWAUAAAF, Wright Patterson AFB, OH 45433-6543. ES-2
Vanderploeg, Rodney D; Cooper, Douglas B; Belanger, Heather G; Donnell, Alison J; Kennedy, Jan E; Hopewell, Clifford A; Scott, Steven G
2014-01-01
To develop and cross-validate internal validity scales for the Neurobehavioral Symptom Inventory (NSI). Four existing data sets were used: (1) outpatient clinical traumatic brain injury (TBI)/neurorehabilitation database from a military site (n = 403), (2) National Department of Veterans Affairs TBI evaluation database (n = 48 175), (3) Florida National Guard nonclinical TBI survey database (n = 3098), and (4) a cross-validation outpatient clinical TBI/neurorehabilitation database combined across 2 military medical centers (n = 206). Secondary analysis of existing cohort data to develop (study 1) and cross-validate (study 2) internal validity scales for the NSI. The NSI, Mild Brain Injury Atypical Symptoms, and Personality Assessment Inventory scores. Study 1: Three NSI validity scales were developed, composed of 5 unusual items (Negative Impression Management [NIM5]), 6 low-frequency items (LOW6), and the combination of 10 nonoverlapping items (Validity-10). Cut scores maximizing sensitivity and specificity on these measures were determined, using a Mild Brain Injury Atypical Symptoms score of 8 or more as the criterion for invalidity. Study 2: The same validity scale cut scores again resulted in the highest classification accuracy and optimal balance between sensitivity and specificity in the cross-validation sample, using a Personality Assessment Inventory Negative Impression Management scale with a T score of 75 or higher as the criterion for invalidity. The NSI is widely used in the Department of Defense and Veterans Affairs as a symptom-severity assessment following TBI, but is subject to symptom overreporting or exaggeration. This study developed embedded NSI validity scales to facilitate the detection of invalid response styles. The NSI Validity-10 scale appears to hold considerable promise for validity assessment when the NSI is used as a population-screening tool.
Identifying dyspepsia in the Greek population: translation and validation of a questionnaire.
Anastasiou, Foteini; Antonakis, Nikos; Chaireti, Georgia; Theodorakis, Pavlos N; Lionis, Christos
2006-03-04
Studies on clinical issues, including diagnostic strategies, are considered to be the core content of general practice research. The use of standardised instruments is regarded as an important component for the development of Primary Health Care research capacity. Demand for epidemiological cross-cultural comparisons in the international setting and the use of common instruments and definitions valid to each culture is bigger than ever. Dyspepsia is a common complaint in primary practice but little is known with respect to its incidence in Greece. There are some references about the Helicobacter Pylori infection in patients with functional dyspepsia or gastric ulcer in Greece but there is no specific instrument for the identification of dyspepsia. This paper reports on the validation and translation into Greek, of an English questionnaire for the identification of dyspepsia in the general population and discusses several possibilities of its use in the Greek primary care. The selected English postal questionnaire for the identification of people with dyspepsia in the general population consists of 30 items and was developed in 1995. The translation and cultural adaptation of the questionnaire has been performed according to international standards. For the validation of the instrument the internal consistency of the items was established using the alpha coefficient of Chronbach, the reproducibility (test - retest reliability) was measured by kappa correlation coefficient and the criterion validity was calculated against the diagnosis of the patients' records using also kappa correlation coefficient. The final Greek version of the postal questionnaire for the identification of dyspepsia in the general population was reliably translated. The internal consistency of the questionnaire was good, Chronbach's alpha was found to be 0.88 (95% CI: 0.81-0.93), suggesting that all items were appropriate to measure. Kappa coefficient for reproducibility (test - retest reliability) was found 0.66 (95% CI: 0.62-0.71), whereas the kappa analysis for criterion validity was 0.63 (95% CI: 0.36-0.89). This study indicates that the Greek translation is comparable with the English-language version in terms of validity and reliability, and is suitable for epidemiological research within the Greek primary health care setting.
Cross-Validation of Survival Bump Hunting by Recursive Peeling Methods.
Dazard, Jean-Eudes; Choe, Michael; LeBlanc, Michael; Rao, J Sunil
2014-08-01
We introduce a survival/risk bump hunting framework to build a bump hunting model with a possibly censored time-to-event type of response and to validate model estimates. First, we describe the use of adequate survival peeling criteria to build a survival/risk bump hunting model based on recursive peeling methods. Our method called "Patient Recursive Survival Peeling" is a rule-induction method that makes use of specific peeling criteria such as hazard ratio or log-rank statistics. Second, to validate our model estimates and improve survival prediction accuracy, we describe a resampling-based validation technique specifically designed for the joint task of decision rule making by recursive peeling (i.e. decision-box) and survival estimation. This alternative technique, called "combined" cross-validation is done by combining test samples over the cross-validation loops, a design allowing for bump hunting by recursive peeling in a survival setting. We provide empirical results showing the importance of cross-validation and replication.
Cross-Validation of Survival Bump Hunting by Recursive Peeling Methods
Dazard, Jean-Eudes; Choe, Michael; LeBlanc, Michael; Rao, J. Sunil
2015-01-01
We introduce a survival/risk bump hunting framework to build a bump hunting model with a possibly censored time-to-event type of response and to validate model estimates. First, we describe the use of adequate survival peeling criteria to build a survival/risk bump hunting model based on recursive peeling methods. Our method called “Patient Recursive Survival Peeling” is a rule-induction method that makes use of specific peeling criteria such as hazard ratio or log-rank statistics. Second, to validate our model estimates and improve survival prediction accuracy, we describe a resampling-based validation technique specifically designed for the joint task of decision rule making by recursive peeling (i.e. decision-box) and survival estimation. This alternative technique, called “combined” cross-validation is done by combining test samples over the cross-validation loops, a design allowing for bump hunting by recursive peeling in a survival setting. We provide empirical results showing the importance of cross-validation and replication. PMID:26997922
Ullrich-French, Sarah; González Hernández, Juan; Hidalgo Montesinos, María D
2017-02-01
Mindfulness is an increasingly popular construct with promise in enhancing multiple positive health outcomes. Physical activity is an important behavior for enhancing overall health, but no Spanish language scale exists to test how mindfulness during physical activity may facilitate physical activity motivation or behavior. This study examined the validity of a Spanish adaption of a new scale, the State Mindfulness Scale for Physical Activity, to assess mindfulness during a specific experience of physical activity. Spanish youths (N = 502) completed a cross-sectional survey of state mindfulness during physical activity and physical activity motivation regulations based on Self-Determination Theory. A high-order model fit the data well and supports the use of one general state mindfulness factor or the use of separate subscales of mindfulness of mental (e.g., thoughts, emotions) and body (physical movement, muscles) aspects of the experience. Internal consistency reliability was good for the general scale and both sub-scales. The pattern of correlations with motivation regulations provides further support for construct validity with significant and positive correlations with self-determined forms of motivation and significant and negative correlations with external regulation and amotivation. Initial validity evidence is promising for the use of the adapted measure.
Risk Competence in Dealing With Alcohol and Other Drugs in Adolescence.
Nagy, Ede; Verres, Rolf; Grevenstein, Dennis
2017-12-06
Adolescence is a critical phase for the development substance use patterns. We propose that individual competence in dealing with psychoactive substances is crucial for the development of healthy substance use behavior and prevention of substance misuse or addiction. We present a new concept of health related skills in dealing with alcohol and other drugs in adolescence, its operationalization and validation. Our conception of risk competence (RICO) consists of the four major factors being Reflective, Informed, Self-Controlled and Life-Oriented, and their sub-facets. Based on a sample of N = 753 adolescents we used classical test theory as well as item response theory to create a new measure of RICO. Validity was investigated in a new sample of N = 229 with regard to substance use, risk perception, and measures of personality (Big Five, sense of coherence, general self-efficacy). RICO contains 7 scales with 28 items that measure independent aspects of risk competence. Cross-sectional criterion validity for most of the scales could be shown. Conclusions/Importance: The new RICO scales are a valid measure of different aspects of risk competence in dealing with psychoactive substances. The questionnaire can be used in general research settings, but may also be applied to assess the effects of interventions.
Cross-Validation of easyCBM Reading Cut Scores in Oregon: 2009-2010. Technical Report #1108
ERIC Educational Resources Information Center
Park, Bitnara Jasmine; Irvin, P. Shawn; Anderson, Daniel; Alonzo, Julie; Tindal, Gerald
2011-01-01
This technical report presents results from a cross-validation study designed to identify optimal cut scores when using easyCBM[R] reading tests in Oregon. The cross-validation study analyzes data from the 2009-2010 academic year for easyCBM[R] reading measures. A sample of approximately 2,000 students per grade, randomly split into two groups of…
New perspectives on the dynamics of AC and DC plasma arcs exposed to cross-fields
NASA Astrophysics Data System (ADS)
Abdo, Youssef; Rohani, Vandad; Cauneau, François; Fulcheri, Laurent
2017-02-01
Interactions between an arc and external fields are crucially important for the design and the optimization of modern plasma torches. Multiple studies have been conducted to help better understand the behavior of DC and AC current arcs exposed to external and ‘self-induced’ magnetic fields, but the theoretical foundations remain very poorly explored. An analytical investigation has therefore been carried out in order to study the general behavior of DC and AC arcs under the effect of random cross-fields. A simple differential equation describing the general behavior of a planar DC or AC arc has been obtained. Several dimensionless numbers that depend primarily on arc and field parameters and the main arc characteristics (temperature, electric field strength) have also been determined. Their magnitude indicates the general tendency pattern of the arc evolution. The analytical results for many case studies have been validated using an MHD numerical model. The main purpose of this investigation was deriving a practical analytical model for the electric arc, rendering possible its stabilization and control, and the enhancement of the plasma torch power.
NASA Astrophysics Data System (ADS)
Battistella, C.; Robinson, D.; McQuarrie, N.; Ghoshal, S.
2017-12-01
Multiple valid balanced cross sections can be produced from mapped surface and subsurface data. By integrating low temperature thermochronologic data, we are better able to predict subsurface geometries. Existing valid balanced cross section for far western Nepal are few (Robinson et al., 2006) and do not incorporate thermochronologic data because the data did not exist. The data published along the Simikot cross section along the Karnali River since then include muscovite Ar, zircon U-Th/He and apatite fission track. We present new mapping and a new valid balanced cross section that takes into account the new field data as well as the limitations that thermochronologic data places on the kinematics of the cross section. Additional constrains include some new geomorphology data acquired since 2006 that indicate areas of increased vertical uplift, which indicate locations of buried ramps in the Main Himalayan thrust and guide the locations of Lesser Himalayan ramps in the balanced cross section. Future work will include flexural modeling, new low temperature thermochronometic data, and 2-D thermokinematic models from a sequentially forward modeled balanced cross sections in far western Nepal.
NASA Astrophysics Data System (ADS)
Gutiérrez, Jose Manuel; Maraun, Douglas; Widmann, Martin; Huth, Radan; Hertig, Elke; Benestad, Rasmus; Roessler, Ole; Wibig, Joanna; Wilcke, Renate; Kotlarski, Sven
2016-04-01
VALUE is an open European network to validate and compare downscaling methods for climate change research (http://www.value-cost.eu). A key deliverable of VALUE is the development of a systematic validation framework to enable the assessment and comparison of both dynamical and statistical downscaling methods. This framework is based on a user-focused validation tree, guiding the selection of relevant validation indices and performance measures for different aspects of the validation (marginal, temporal, spatial, multi-variable). Moreover, several experiments have been designed to isolate specific points in the downscaling procedure where problems may occur (assessment of intrinsic performance, effect of errors inherited from the global models, effect of non-stationarity, etc.). The list of downscaling experiments includes 1) cross-validation with perfect predictors, 2) GCM predictors -aligned with EURO-CORDEX experiment- and 3) pseudo reality predictors (see Maraun et al. 2015, Earth's Future, 3, doi:10.1002/2014EF000259, for more details). The results of these experiments are gathered, validated and publicly distributed through the VALUE validation portal, allowing for a comprehensive community-open downscaling intercomparison study. In this contribution we describe the overall results from Experiment 1), consisting of a European wide 5-fold cross-validation (with consecutive 6-year periods from 1979 to 2008) using predictors from ERA-Interim to downscale precipitation and temperatures (minimum and maximum) over a set of 86 ECA&D stations representative of the main geographical and climatic regions in Europe. As a result of the open call for contribution to this experiment (closed in Dec. 2015), over 40 methods representative of the main approaches (MOS and Perfect Prognosis, PP) and techniques (linear scaling, quantile mapping, analogs, weather typing, linear and generalized regression, weather generators, etc.) were submitted, including information both data (downscaled values) and metadata (characterizing different aspects of the downscaling methods). This constitutes the largest and most comprehensive to date intercomparison of statistical downscaling methods. Here, we present an overall validation, analyzing marginal and temporal aspects to assess the intrinsic performance and added value of statistical downscaling methods at both annual and seasonal levels. This validation takes into account the different properties/limitations of different approaches and techniques (as reported in the provided metadata) in order to perform a fair comparison. It is pointed out that this experiment alone is not sufficient to evaluate the limitations of (MOS) bias correction techniques. Moreover, it also does not fully validate PP since we don't learn whether we have the right predictors and whether the PP assumption is valid. These problems will be analyzed in the subsequent community-open VALUE experiments 2) and 3), which will be open for participation along the present year.
Talip, Whadi-ah; Steyn, Nelia P; Visser, Marianne; Charlton, Karen E; Temple, Norman
2003-09-01
We wanted to develop and validate a test that assesses the knowledge and practices of health professionals (HPs) with regard to the role of nutrition, physical activity, and smoking cessation (lifestyle modification) in chronic diseases of lifestyle. A descriptive cross-sectional validation study was carried out. The validation design consisted of two phases, namely 1) test planning and development and 2) test evaluation. The study sample consisted of five groups of HPs: dietitians, dietetic interns, general practitioners, medical students, and nurses. The overall response rate was 58%, resulting in a sample size of 186 participants. A test was designed to evaluate the knowledge and practices of HPs. The test was first evaluated by an expert group to ensure content, construct, and face validity. Thereafter, the questionnaire was tested on five groups of HPs to test for criterion validity. Internal consistency was evaluated by Cronbach's alpha. An expert panel ensured content, construct, and face validity of the test. Groups with the most training and exposure to nutrition (dietitians and dietetic interns) had the highest group mean score, ranging from 61% to 88%, whereas those with limited nutrition training (general practitioners, medical students, and nurses) had significantly lower scores, ranging from 26% to 80%. This result demonstrated criterion validity. Internal consistency of the overall test demonstrated a Cronbach's alpha of 0.99. Most HPs identified the mass media as their main source of information on lifestyle modification. These HPs also identified lack of time, lack of patient compliance, and lack of knowledge as barriers that prevent them from providing counseling on lifestyle modification. The results of this study showed that this test instrument identifies groups of health professionals with adequate training (knowledge) in lifestyle modification and those who require further training (knowledge).
Kwan, Yu Heng; Fong, Warren Weng Seng; Lui, Nai Lee; Yong, Si Ting; Cheung, Yin Bun; Malhotra, Rahul; Østbye, Truls; Thumboo, Julian
2016-12-01
The Short Form 36 Health Survey (SF-36) is a popular health-related quality of life (HrQoL) tool. However, few studies have assessed its psychometric properties in patients with spondyloarthritis (SpA). We therefore aimed to assess the reliability and validity of the SF-36 in patients with SpA in Singapore. Cross-sectional data from a registry of 196 SpA patients recruited from a dedicated tertiary referral clinic in Singapore from 2011 to 2014 was used. Analyses were guided by the COnsensus-based Standards for the selection of health Measurement INstruments framework. Internal consistency reliability was assessed using Cronbach's alpha. Construct validity was assessed through 33 a priori hypotheses by correlations of the eight subscales and two summary scores of SF-36 with other health outcomes. Known-group construct validity was assessed by comparison of the means of the subscales and summary scores of the SF-36 of SpA patients and the general population of Singapore using student's t tests. Among 196 patients (155 males (79.0 %), median (range) age: 36 (17-70), 166 Chinese (84.6 %)), SF-36 scales showed high internal consistency ranging from 0.88 to 0.90. Convergent construct validity was supported as shown by fulfillment of all hypotheses. Divergent construct validity was supported, as SF-36 MCS was not associated with PGA, pain and HAQ. Known-group construct validity showed SpA patients had lower scores of 3.8-12.5 when compared to the general population at p < 0.001. This study supports the SF-36 as a valid and reliable measure of HrQoL for use in patients with SpA at a single time point.
Indicators of Ecological Change
2005-03-01
Vine 0.07 0.26 Yellow Jasmine LM Gymnopogon ambiguus Graminae Cryptophyte Geophyte Grass 0.17 0.45 Beard grass RLD Haplopappus divaricatus Asteraceae...cross-validation procedure. The cross-validation analysis 7 determines the percentage of observations correctly classified. In essence , a cross-8
Empirical Performance of Cross-Validation With Oracle Methods in a Genomics Context
Martinez, Josue G.; Carroll, Raymond J.; Müller, Samuel; Sampson, Joshua N.; Chatterjee, Nilanjan
2012-01-01
When employing model selection methods with oracle properties such as the smoothly clipped absolute deviation (SCAD) and the Adaptive Lasso, it is typical to estimate the smoothing parameter by m-fold cross-validation, for example, m = 10. In problems where the true regression function is sparse and the signals large, such cross-validation typically works well. However, in regression modeling of genomic studies involving Single Nucleotide Polymorphisms (SNP), the true regression functions, while thought to be sparse, do not have large signals. We demonstrate empirically that in such problems, the number of selected variables using SCAD and the Adaptive Lasso, with 10-fold cross-validation, is a random variable that has considerable and surprising variation. Similar remarks apply to non-oracle methods such as the Lasso. Our study strongly questions the suitability of performing only a single run of m-fold cross-validation with any oracle method, and not just the SCAD and Adaptive Lasso. PMID:22347720
Kumar, Narendra; Rajendra, Rajagopal; Majgi, Sumanth Mallikarjuna; Krishna, Murali; Keenan, Paul; Jones, Steve
2016-01-01
There is growing global interest into the attitudes and clinical management of persons who deliberately self-harm. People who self-harm experience many problems and typically have many needs related to management of their psychological wellbeing. A positive attitude amongst general hospital staff should prevail with people who self-harm. The principal purpose was to determine student staff attitudes towards patients who self-harmed from a professional and cultural perspective, which might influence patient treatment following hospital admission. The focus concentrated upon staff knowledge, attitudes and beliefs regarding self-harm. A cross sectional survey of the hospital staff using a validated questionnaire was carried out. This paper reports on interdisciplinary staff from two large general hospitals in Mysuru, South India (n=773). Findings suggest that within a general hospital setting there is wide variation in staff attitudes and knowledge levels related to self-harm. Whilst there is attitudinal evidence for staff attitudes, this study investigates interprofessional differences in an attempt to progress treatment approaches to a vulnerable societal group. Very few staff had any training in assessment of self harm survivors. There is an urgent need for training general hospital staff in self harm assessment and prevention in south India. The results allow a series of recommendations for educational and skills initiatives before progressing to patient assessment and treatment projects and opens potential for cross cultural comparison studies. In addition, interventions must focus on current resources and contexts to move the evidence base and approaches to patient care forward.
Good validity of the international spinal cord injury quality of life basic data set.
Post, M W M; Adriaansen, J J E; Charlifue, S; Biering-Sørensen, F; van Asbeck, F W A
2016-04-01
Cross-sectional validation study. To examine the construct and concurrent validity of the International Spinal Cord Injury (SCI) Quality of Life (QoL) Basic Data Set. Dutch community. People 28-65 years of age, who obtained their SCI between 18 and 35 years of age, were at least 10 years post SCI and were wheelchair users in daily life. MEASURE(S): The International SCI QoL Basic Data Set consists of three single items on satisfaction with life as a whole, physical health and psychological health (0=complete dissatisfaction; 10=complete satisfaction). Reference measures were the Mental Health Inventory-5 and three items of the World Health Organization Quality of Life measure. Data of 261 participants were available. Mean time after SCI was 24.1 years (s.d. 9.1); 90.4% had a traumatic SCI, 81.5% a motor complete SCI and 40% had tetraplegia. Mean age was 47.9 years (s.d. 8.8) and 73.2% were male. Mean scores were 6.9 (s.d. 1.9) for general QoL, 5.8 (s.d. 2.2) for physical health and 7.1 (s.d. 1.9) for psychological health. No floor or ceiling effects were found. Strong inter-correlations (0.48-0.71) were found between the items, and Cronbach's alpha of the scale was good (0.81). Correlations with the reference measures showed the strongest correlations between the WHOQOL general satisfaction item and general QoL (0.64), the WHOQOL health and daily activities items and physical health (0.69 and 0.60) and the Mental Health Inventory-5 and psychological health (0.70). This first validity study of the International SCI QoL Basic Data Set shows that it appears valid for persons with SCI.
Cross-Validation of Predictor Equations for Armor Crewman Performance
1980-01-01
Technical Report 447 CROSS-VALIDATION OF PREDICTOR EQUATIONS FOR ARMOR CREWMAN PERFORMANCE Anthony J. Maitland , Newell K. Eaton, and Janet F. Neft...ORG. REPORT NUMBER Anthony J/ Maitland . Newell K/EatorV. and B OTATO RN UBR. 9- PERFORMING ORGANIZATION NAME AND ADDRESS I0. PROGRAM ELEMENT, PROJECT...Technical Report 447 CROSS-VALIDATION OF PREDICTOR EQUATIONS FOR ARMOR CREWMAN PERFORMANCE Anthony J. Maitland , Newell K. Eaton, Accession For and
Statistical validation of normal tissue complication probability models.
Xu, Cheng-Jian; van der Schaaf, Arjen; Van't Veld, Aart A; Langendijk, Johannes A; Schilstra, Cornelis
2012-09-01
To investigate the applicability and value of double cross-validation and permutation tests as established statistical approaches in the validation of normal tissue complication probability (NTCP) models. A penalized regression method, LASSO (least absolute shrinkage and selection operator), was used to build NTCP models for xerostomia after radiation therapy treatment of head-and-neck cancer. Model assessment was based on the likelihood function and the area under the receiver operating characteristic curve. Repeated double cross-validation showed the uncertainty and instability of the NTCP models and indicated that the statistical significance of model performance can be obtained by permutation testing. Repeated double cross-validation and permutation tests are recommended to validate NTCP models before clinical use. Copyright © 2012 Elsevier Inc. All rights reserved.
Cross-Validation of the Africentrism Scale.
ERIC Educational Resources Information Center
Kwate, Naa Oyo A.
2003-01-01
Cross-validated the Africentrism Scale, investigating the relationship between Africentrism and demographic variables in a diverse sample of individuals of African descent. Results indicated that the scale demonstrated solid internal consistency and convergent validity. Age and education related to Africentrism, with younger and less educated…
Machado, Roberta Ismael Lacerda; Souto, Lais Medeiros; Freire, Eutilia Andrade Medeiros
2014-01-01
Systemic sclerosis (SSc) is a multisystem disease, autoimmune disorder characterized by a fibroblastic disfunction, with significant impact on quality of life (QoL), measured by instruments or questionnaires that usually were formulated in other languages and in different cultural contexts. Translate into Brazilian Portuguese, cross cultural adaptation and assess the reliability and validity of the Systemic Sclerosis Questionnaire (SySQ). Translation and adaptation: into Portuguese and cross-cultural adaptation was performed in accordance with studies on questionnaire translation methodology into other languages. Reliability: it was analyzed using three interviews with different interviewers, two on the same day (interobserver) and the third within 14 days of the first assessment (intraobserver).Validity was assessed by correlating clinical and quality of life parameters with the domain scores of Sysc. a descriptive analysis of the study sample. Reproducibility was assessed using an intraclass correlation coefficient (ICC). Internal consistency was assessed using Cronbach's alpha coefficient. To assess validity we used Spearman correlation coefficient. Five percent was the level of significance adopted for all statistical tests. In the evaluation of the questionnaires, the results were similar to the original questionnaire, the internal consistency ranging between 0.73 and 0.93 for each item. The interobserver reproducibility was very good for all domains (α = 0.786 to 0.983) and intraobserver agreement was considered very good for general symptoms domain (ICC = 0.916), good for musculoskeletal symptoms domain (ICC = 0.897) and cardiopulmonary domain (ICC = 0.842) and reasonable for gastrointestinal symptoms domain (ICC = 0.686). The Brazilian Portuguese version of SySQ proved to be reproducible and valid for our population, using a recognized methodology for translation and cultural adaptation of questionnaires, as well as to assess the reproducibility and validity.
NASA Astrophysics Data System (ADS)
Zhang, Lei; Li, Dong; Liu, Yu; Liu, Jingxiao; Li, Jingsong; Yu, Benli
2017-11-01
We demonstrate the validity of the simultaneous reverse optimization reconstruction (SROR) algorithm in circular subaperture stitching interferometry (CSSI), which is previously proposed for non-null aspheric annular subaperture stitching interferometry (ASSI). The merits of the modified SROR algorithm in CSSI, such as auto retrace error correction, no need of overlap and even permission of missed coverage, are analyzed in detail in simulations and experiments. Meanwhile, a practical CSSI system is proposed for this demonstration. An optical wedge is employed to deflect the incident beam for subaperture scanning by its rotation and shift instead of the six-axis motion-control system. Also the reference path can provide variable Zernike defocus for each subaperture test, which would decrease the fringe density. Experiments validating the SROR algorithm in this CSSI is implemented with cross validation by testing of paraboloidal mirror, flat mirror and astigmatism mirror. It is an indispensable supplement in SROR application in general subaperture stitching interferometry.
Validation of Bengali perceived stress scale among LGBT population.
Mozumder, Muhammad Kamruzzaman
2017-08-29
Lesbian, gay, bisexual and transgender (LGBT) population encounter more stressful life circumstances compared to general population. Perceived Stress Scale (PSS) can be a useful tool for measuring their stress. However, psychometric properties of PSS have never been tested on LGBT population. This cross sectional study employed a two-stage sampling strategy to collect data from 296 LGBT participants from six divisional districts of Bangladesh. Exploratory (EFA) and confirmatory factor analysis (CFA) were carried out on PSS 10 along with analysis of reliability and validity. EFA revealed a two-factor structure of PSS for LGBT population explaining 43.55% - 51.45% of total variance. This measurement model was supported by multiple fit indices during CFA. Acceptable Cronbach's alpha indicated internal consistency reliability and high correlations with Self Reporting Questionnaire 20 demonstrated construct validity of PSS 10 for LGBT population. This study provided evidence of satisfactory psychometric properties of Bengali PSS 10 in terms of factor structure, internal consistency and validity among LGBT population.
Resilience Scale-25 Spanish version: validation and assessment in eating disorders.
Las Hayas, Carlota; Calvete, Esther; Gómez del Barrio, Andrés; Beato, Luís; Muñoz, Pedro; Padierna, Jesús Ángel
2014-08-01
To validate into Spanish the Wagnild and Young Resilience Scale - 25 (RS-25), assess and compare the scores on the scale among women from the general population, eating disorder (ED) patients and recovered ED patients. This is a cross-sectional study. ED participants were invited to participate by their respective therapists. The sample from the general population was gathered via an open online survey. Participants (N general population=279; N ED patients=124; and N recovered ED patients=45) completed the RS-25, the World Health Organization Quality of Life Scale-BREF and the Hospital Anxiety and Depression Scale. Mean age of participants ranged from 28.87 to 30.42years old. Statistical analysis included a multi-group confirmatory factor analysis and ANOVA. The two-factor model of the RS-25 produced excellent fit indexes. Measurement invariance across samples was generally supported. The ANOVA found statistically significant differences in the RS-25 mean scores between the ED patients (Mean=103.13, SD=31.32) and the recovered ED participants (Mean=138.42, SD=22.26) and between the ED patients and the general population participants (Mean=136.63, SD=19.56). The Spanish version of the RS-25 is a psychometrically sound measurement tool in samples of ED patients. Resilience is lower in people diagnosed with ED than in recovered individuals and the general population. Copyright © 2014 Elsevier Ltd. All rights reserved.
Neuro-QoL health-related quality of life measurement system: Validation in Parkinson's disease.
Nowinski, Cindy J; Siderowf, Andrew; Simuni, Tanya; Wortman, Catherine; Moy, Claudia; Cella, David
2016-05-01
Neuro-QoL is a multidimensional patient-reported outcome measurement system assessing aspects of physical, mental, and social health identified by neurology patients and caregivers as important. One of the first neurology-specific patient-reported outcome measure systems created using modern test development methods, Neuro-Qol enables brief, yet precise, assessment and the ability to conduct both PD-specific and cross-disease comparisons. We present results of Neuro-QoL clinical validation using a sample of PD patients. A total of 120 PD patients recruited from academic medical centers were assessed at baseline, 1 week, and 6 months. Assessments included Neuro-QoL and general and PD-specific validity measures. Participants were 62% male and 95% white (average age = 66); H & Y stages were 1 (16%), 2 (61%), 3 (18%), and 4 (5%). Internal consistency and test-retest reliability of Neuro-QoL ranged from Cronbach's alphas = 0.81 to 0.94 with intraclass correlation coefficients = 0.66 to 0.80. Pearson's correlations between Neuro-QoL and legacy measures were generally moderate and in expected directions. UPDRS Part 2 was moderately correlated with Neuro-QoL Upper Extremity and Mobility, respectively (r's = -0.44; -0.59). Parkinson's Disease Questionnaire-39 and Neuro-QoL measures of similar constructs showed strong-to-moderate correlations (r's = 0.70-0.44). Neuro-QoL measures of fatigue, mobility, positive emotion, and emotional/behavioral control showed responsiveness to self-reported change. Neuro-QoL is valid for use in PD clinical research. Reliability for all but two measures is sufficient for group comparisons, with some evidence supporting responsiveness to change. Neuro-QoL possesses characteristics, such as brevity, flexibility in administration, and suitability, for cross-disease comparisons that may be advantageous to users in a variety of settings. © 2016 Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.
Sierakowska, Matylda; Sierakowski, Stanisław; Sierakowska, Justyna; Horton, Mike; Ndosi, Mwidimi
2015-03-01
To undertake cross-cultural adaptation and validation of the educational needs assessment tool (ENAT) for use with people with rheumatoid arthritis (RA) and systemic sclerosis (SSc) in Poland. The study involved two main phases: (1) cross-cultural adaptation of the ENAT from English into Polish and (2) Cross-cultural validation of Polish Educational Needs Assessment Tool (Pol-ENAT). The first phase followed an established process of cross-cultural adaptation of self-report measures. The second phase involved completion of the Pol-ENAT by patients and subjecting the data to Rasch analysis to assess the construct validity, unidimensionality, internal consistency and cross-cultural invariance. An adequate conceptual equivalence was achieved following the adaptation process. The dataset for validation comprised a total of 278 patients, 237 (85.3 %) of which were female. In each disease group (145, RA and 133, SSc), the 7 domains of the Pol-ENAT were found to fit the Rasch model, X (2)(df) = 16.953(14), p = 0.259 and 8.132(14), p = 0.882 for RA and SSc, respectively. Internal consistency of the Pol-ENAT was high (patient separation index = 0.85 and 0.89 for SSc and RA, respectively), and unidimensionality was confirmed. Cross-cultural differential item functioning (DIF) was detected in some subscales, and DIF-adjusted conversion tables were calibrated to enable cross-cultural comparison of data between Poland and the UK. Using a standard process in cross-cultural adaptation, conceptual equivalence was achieved between the original (UK) ENAT and the adapted Pol-ENAT. Fit to the Rasch model, confirmed that the construct validity, unidimensionality and internal consistency of the ENAT have been preserved.
NHRC (Naval Health Research Center) Report for 1979
1979-01-01
of cross- validation analyses on an independent sample (n = 336) were also reported and were generally consistent with the foregoing analyses. 79-3...antigens in sputum. Initial sputum samples from patients with pneumococcal p,; Lmonia ( hr antibiotic therapy) were positive for antigen in 37 of 44...the decline was gree’ar for CIE (only 29% of samples positive at three days of therapy) than with coagglutination (61% positive at three days) (pɘ.05
Internet Gaming Disorder: Investigating the Clinical Relevance of a New Phenomenon.
Przybylski, Andrew K; Weinstein, Netta; Murayama, Kou
2017-03-01
The American Psychiatric Association (APA) identified Internet gaming disorder as a new potential psychiatric disorder and has recognized that little is known about the prevalence, validity, or cross-cultural robustness of proposed Internet gaming disorder criteria. In response to this gap in our understanding, the present study, a first for this research topic, estimated the period prevalence of this new potential psychiatric disorder using APA guidance, examined the validity of its proposed indicators, evaluated reliability cross-culturally and across genders, compared it to gold-standard research on gambling addiction and problem gaming, and estimated its impact on physical, social, and mental health. Four survey studies (N=18,932) with large international cohorts employed an open-science methodology wherein the analysis plans for confirmatory hypotheses were registered prior to data collection. Among those who played games, more than 2 out of 3 did not report any symptoms of Internet gaming disorder, and findings showed that a very small proportion of the general population (between 0.3% and 1.0%) might qualify for a potential acute diagnosis of Internet gaming disorder. Comparison to gambling disorder revealed that Internet-based games may be significantly less addictive than gambling and similarly dysregulating as electronic games more generally. The evidence linking Internet gaming disorder to game engagement was strong, but links to physical, social, and mental health outcomes were decidedly mixed.
Methods to compute reliabilities for genomic predictions of feed intake
USDA-ARS?s Scientific Manuscript database
For new traits without historical reference data, cross-validation is often the preferred method to validate reliability (REL). Time truncation is less useful because few animals gain substantial REL after the truncation point. Accurate cross-validation requires separating genomic gain from pedigree...
Cross-cultural adaptation of the Individual Work Performance Questionnaire.
Koopmans, Linda; Bernaards, Claire M; Hildebrandt, Vincent H; Lerner, Debra; de Vet, Henrica C W; van der Beek, Allard J
2015-01-01
The Individual Work Performance Questionnaire (IWPQ), measuring task performance, contextual performance, and counterproductive work behavior, was developed in The Netherlands. To cross-culturally adapt the IWPQ from the Dutch to the American-English language, and assess the questionnaire's internal consistency and content validity in the American-English context. A five stage translation and adaptation process was used: forward translation, synthesis, back-translation, expert committee review, and pilot-testing. During the pilot-testing, cognitive interviews with 40 American workers were performed, to examine the comprehensibility, applicability, and completeness of the American-English IWPQ. Questionnaire instructions were slightly modified to aid interpretation in the American-English language. Inconsistencies with verb tense were identified, and it was decided to consistently use simple past tense. The wording of five items was modified to better suit the American-English language. In general, participants were positive on the comprehensibility, applicability and completeness of the questionnaire during the pilot-testing phase. Furthermore, the study showed positive results concerning the internal consistency (Cronbach's alphas for the scales between 0.79-0.89) and content validity of the American-English IWPQ. The results indicate that the cross-cultural adaptation of the American-English IWPQ was successful and that the measurement properties of the translated version are promising.
Sun, Jiangming; Carlsson, Lars; Ahlberg, Ernst; Norinder, Ulf; Engkvist, Ola; Chen, Hongming
2017-07-24
Conformal prediction has been proposed as a more rigorous way to define prediction confidence compared to other application domain concepts that have earlier been used for QSAR modeling. One main advantage of such a method is that it provides a prediction region potentially with multiple predicted labels, which contrasts to the single valued (regression) or single label (classification) output predictions by standard QSAR modeling algorithms. Standard conformal prediction might not be suitable for imbalanced data sets. Therefore, Mondrian cross-conformal prediction (MCCP) which combines the Mondrian inductive conformal prediction with cross-fold calibration sets has been introduced. In this study, the MCCP method was applied to 18 publicly available data sets that have various imbalance levels varying from 1:10 to 1:1000 (ratio of active/inactive compounds). Our results show that MCCP in general performed well on bioactivity data sets with various imbalance levels. More importantly, the method not only provides confidence of prediction and prediction regions compared to standard machine learning methods but also produces valid predictions for the minority class. In addition, a compound similarity based nonconformity measure was investigated. Our results demonstrate that although it gives valid predictions, its efficiency is much worse than that of model dependent metrics.
Lucena-Santos, Paola; Trindade, Inês A; Oliveira, Margareth; Pinto-Gouveia, José
2017-05-19
Given the clinical usefulness of the CFQ-BI (Cognitive Fusion Questionnaire-Body Image; the only existing measure to assess the body-image-related cognitive fusion), the present study aimed to confirm its one-factor structure, to verify its measurement invariance between clinical and non-clinical samples, to analyze its internal consistency and sensitivity to detect differences between samples, as well as to explore the incremental and convergent validities of the CFQ-BI scores in Brazilian samples. This was a cross-sectional study, which was conducted in clinical (women with overweight or obesity in treatment for weight loss) and non-clinical samples (women from the general population). The one-factor structure was confirmed showing factorial measurement invariance across clinical and non-clinical samples. The CFQ-BI scores presented an excellent internal consistency, were able to discriminate clinical and non-clinical samples, and were positively associated with binge eating severity, general cognitive fusion, and psychological inflexibility. Furthermore, body-image-related cognitive fusion scores (CFQ-BI) presented incremental validity over a general measure of cognitive fusion in the prediction of binge eating symptoms. This study demonstrated that CFQ-BI is a short scale with reliable and robust scores in Brazilian samples, presenting incremental and convergent validities, measurement invariance, and sensitivity to detect differences between clinical and non-clinical groups of women, enabling comparative studies between them.
Thaler, Kylie; Harris, Mark F
2012-01-01
Objective To assess if data collected by a consumer organisation are valid for a health service research study on physicians' performance in preventive care. To report first results of the analysis of physicians performance like consultation time and guideline adherence in history taking. Design Secondary data analysis of a clustered cross-sectional direct observation survey. Setting General practitioners (GPs) in Vienna, Austria, visited unannounced by mystery shoppers (incognito standardised patients (ISPs)). Participants 21 randomly selected GPs were visited by two different ISPs each. 40 observation protocols were realised. Main outcome measures Robustness of sampling and data collection by the consumer organisation. GPs consultation and waiting times, guideline adherence in history taking. Results The double stratified random sampling method was robust and representative for the private and contracted GPs mix of Vienna. The clinical scenarios presented by the ISPs were valid and believable, and no GP realised the ISPs were not genuine patients. The average consultation time was 46 min (95% CI 37 to 54 min). Waiting times differed more than consultation times between private and contracted GPs. No differences between private and contracted GPs in terms of adherence to the evidence-based guidelines regarding history taking including questions regarding alcohol use were found. According to the analysis, 20% of the GPs took a perfect history (95% CI 9% to 39%). Conclusions The analysis of secondary data collected by a consumer organisation was a valid method for drawing conclusions about GPs preventive practice. Initial results, like consultation times longer than anticipated, and the moderate quality of history taking encourage continuing the analysis on available clinical data. PMID:22872721
Bruder, Martin; Haffke, Peter; Neave, Nick; Nouripanah, Nina; Imhoff, Roland
2013-01-01
Conspiracy theories are ubiquitous when it comes to explaining political events and societal phenomena. Individuals differ not only in the degree to which they believe in specific conspiracy theories, but also in their general susceptibility to explanations based on such theories, that is, their conspiracy mentality. We present the Conspiracy Mentality Questionnaire (CMQ), an instrument designed to efficiently assess differences in the generic tendency to engage in conspiracist ideation within and across cultures. The CMQ is available in English, German, and Turkish. In four studies, we examined the CMQ’s factorial structure, reliability, measurement equivalence across cultures, and its convergent, discriminant, and predictive validity. Analyses based on a cross-cultural sample (Study 1a; N = 7,766) supported the conceptualization of conspiracy mentality as a one-dimensional construct across the three language versions of the CMQ that is stable across time (Study 1b; N = 141). Multi-group confirmatory factor analysis demonstrated cross-cultural measurement equivalence of the CMQ items. The instrument could therefore be used to examine differences in conspiracy mentality between European, North American, and Middle Eastern cultures. In Studies 2–4 (total N = 476), we report (re-)analyses of three datasets demonstrating the validity of the CMQ in student and working population samples in the UK and Germany. First, attesting to its convergent validity, the CMQ was highly correlated with another measure of generic conspiracy belief. Second, the CMQ showed patterns of meaningful associations with personality measures (e.g., Big Five dimensions, schizotypy), other generalized political attitudes (e.g., social dominance orientation and right-wing authoritarianism), and further individual differences (e.g., paranormal belief, lack of socio-political control). Finally, the CMQ predicted beliefs in specific conspiracy theories over and above other individual difference measures. PMID:23641227
Signal processing and neural network toolbox and its application to failure diagnosis and prognosis
NASA Astrophysics Data System (ADS)
Tu, Fang; Wen, Fang; Willett, Peter K.; Pattipati, Krishna R.; Jordan, Eric H.
2001-07-01
Many systems are comprised of components equipped with self-testing capability; however, if the system is complex involving feedback and the self-testing itself may occasionally be faulty, tracing faults to a single or multiple causes is difficult. Moreover, many sensors are incapable of reliable decision-making on their own. In such cases, a signal processing front-end that can match inference needs will be very helpful. The work is concerned with providing an object-oriented simulation environment for signal processing and neural network-based fault diagnosis and prognosis. In the toolbox, we implemented a wide range of spectral and statistical manipulation methods such as filters, harmonic analyzers, transient detectors, and multi-resolution decomposition to extract features for failure events from data collected by data sensors. Then we evaluated multiple learning paradigms for general classification, diagnosis and prognosis. The network models evaluated include Restricted Coulomb Energy (RCE) Neural Network, Learning Vector Quantization (LVQ), Decision Trees (C4.5), Fuzzy Adaptive Resonance Theory (FuzzyArtmap), Linear Discriminant Rule (LDR), Quadratic Discriminant Rule (QDR), Radial Basis Functions (RBF), Multiple Layer Perceptrons (MLP) and Single Layer Perceptrons (SLP). Validation techniques, such as N-fold cross-validation and bootstrap techniques, are employed for evaluating the robustness of network models. The trained networks are evaluated for their performance using test data on the basis of percent error rates obtained via cross-validation, time efficiency, generalization ability to unseen faults. Finally, the usage of neural networks for the prediction of residual life of turbine blades with thermal barrier coatings is described and the results are shown. The neural network toolbox has also been applied to fault diagnosis in mixed-signal circuits.
Bismark, Andrew W; Thomas, Michael L; Tarasenko, Melissa; Shiluk, Alexandra L; Rackelmann, Sonia Y; Young, Jared W; Light, Gregory A
2018-04-12
Attentional dysfunction contributes to functional impairments in schizophrenia (SZ). Sustained attention is typically assessed via continuous performance tasks (CPTs), though many CPTs have limited cross-species translational validity and place demands on additional cognitive domains. A reverse-translated 5-Choice Continuous Performance Task (5C-CPT) for human testing-originally developed for use in rodents-was designed to minimize demands on perceptual, visual learning, processing speed, or working memory functions. To-date, no studies have validated the 5C-CPT against gold standard attentional measures nor evaluated how 5C-CPT scores relate to cognition in SZ. Here we examined the relationship between the 5C-CPT and the CPT-Identical Pairs (CPT-IP), an established and psychometrically robust measure of vigilance from the MATRICS Consensus Cognitive Battery (MCCB) in a sample of SZ patients (n = 35). Relationships to global and individual subdomains of cognition were also assessed. 5C-CPT and CPT-IP measures of performance (d-prime) were strongly correlated (r = 0.60). In a regression model, the 5C-CPT and CPT-IP collectively accounted for 54% of the total variance in MCCB total scores, and 27.6% of overall cognitive variance was shared between the 5C-CPT and CPT-IP. These results indicate that the reverse translated 5C-CPT and the gold standard CPT-IP index a common attentional construct that also significantly overlaps with variance in general cognitive performance. The use of simple, cross-species validated behavioral indices of attentional/cognitive functioning such as the 5C-CPT could accelerate the development of novel generalized pro-cognitive therapeutics for SZ and related neuropsychiatric disorders.
Küçükdeveci, Ayse A; Sahin, Hülya; Ataman, Sebnem; Griffiths, Bridget; Tennant, Alan
2004-02-15
Guidelines have been established for cross-cultural adaptation of outcome measures. However, invariance across cultures must also be demonstrated through analysis of Differential Item Functioning (DIF). This is tested in the context of a Turkish adaptation of the Health Assessment Questionnaire (HAQ). Internal construct validity of the adapted HAQ is assessed by Rasch analysis; reliability, by internal consistency and the intraclass correlation coefficient; external construct validity, by association with impairments and American College of Rheumatology functional stages. Cross-cultural validity is tested through DIF by comparison with data from the UK version of the HAQ. The adapted version of the HAQ demonstrated good internal construct validity through fit of the data to the Rasch model (mean item fit 0.205; SD 0.998). Reliability was excellent (alpha = 0.97) and external construct validity was confirmed by expected associations. DIF for culture was found in only 1 item. Cross-cultural validity was found to be sufficient for use in international studies between the UK and Turkey. Future adaptation of instruments should include analysis of DIF at the field testing stage in the adaptation process.
Khoury, Samar; Carra, Maria Clotilde; Huynh, Nelly; Montplaisir, Jacques; Lavigne, Gilles J.
2016-01-01
Study Objectives: Sleep bruxism (SB) is characterized by tooth grinding and jaw clenching during sleep. Familial factors may contribute to the occurrence of SB. This study aims are: (1) revisit the prevalence and characteristics of SB in a large cross-sectional survey and assess familial aggregation of SB, (2) assess comorbidity such as insomnia and pain, (3) compare survey data in a subset of subjects diagnosed using polysomnography research criteria. Methods: A sample of 6,357 individuals from the general population in Quebec, Canada, undertook an online survey to assess the prevalence of SB, comorbidities, and familial aggregation. Data on familial aggregation were compared to 111 SB subjects diagnosed using polysomnography. Results: Regularly occurring SB was reported by 8.6% of the general population, decreases with age, without any gender difference. SB awareness is concomitant with complaints of difficulties maintaining sleep in 47.6% of the cases. A third of SB positive probands reported pain. A 2.5 risk ratio of having a first-degree family member with SB was found in SB positive probands. The risk of reporting SB in first-degree family ranges from 1.4 to 2.9 with increasing severity of reported SB. Polysomnographic data shows that 37% of SB subjects had at least one first-degree relative with reported SB with a relative risk ratio of 4.625. Conclusions: Our results support the heritability of SB-tooth grinding and that sleep quality and pain are concomitant in a significant number of SB subjects. Citation: Khoury S, Carra MC, Huynh N, Montplaisir J, Lavigne GJ. Sleep bruxism-tooth grinding prevalence, characteristics and familial aggregation: a large cross-sectional survey and polysomnographic validation. SLEEP 2016;39(11):2049–2056. PMID:27568807
Psychopathy in Bulgaria: The cross-cultural generalizability of the Hare Psychopathy Checklist
Wilson, Michael J.; Abramowitz, Carolyn; Vasilev, Georgi; Bozgunov, Kiril; Vassileva, Jasmin
2014-01-01
The generalizability of the psychopathy construct to Eastern European cultures has not been well-studied, and no prior studies have evaluated psychopathy in non-offender samples from this population. The current validation study examines the factor structure, internal consistency, and external validity of the Bulgarian translation of the Hare Psychopathy Checklist: Screening Version. Two hundred sixty-two Bulgarian adults from the general community were assessed, of which 185 had a history of substance dependence. Confirmatory factor analysis indicated good fit for the two-, three-, and four-factor models of psychopathy. Zero-order and partial correlation analyses were conducted between the two factors of psychopathy and criterion measures of antisocial behavior, internalizing and externalizing psychopathology, personality traits, addictive disorders and demographic characteristics. Relationships to external variables provided evidence for the convergent and discriminant validity of the psychopathy construct in a Bulgarian community sample. PMID:25313268
Power, Thomas J; Watkins, Marley W; Mautone, Jennifer A; Walcott, Christy M; Coutts, Michael J; Sheridan, Susan M
2015-06-01
Methods for measuring homework performance have been limited primarily to parent reports of homework deficits. The Homework Performance Questionnaire (HPQ) was developed to assess the homework functioning of students in Grades 1 to 8 from the perspective of both teachers and parents. The purpose of this study was to examine the factorial validity of teacher and parent versions of this scale, and to evaluate gender and grade-level differences in factor scores. The HPQ was administered in 4 states from varying regions of the United States. The validation sample consisted of students (n = 511) for whom both parent and teacher ratings were obtained (52% female, mean of 9.5 years of age, 79% non-Hispanic, and 78% White). The cross-validation sample included 1,450 parent ratings and 166 teacher ratings with similar demographic characteristics. The results of confirmatory factor analyses demonstrated that the best-fitting model for teachers was a bifactor solution including a general factor and 2 orthogonal factors, referring to student self-regulation and competence. The best-fitting model for parents was also a bifactor solution, including a general factor and 3 orthogonal factors, referring to student self-regulation, student competence, and teacher support of homework. Gender differences were identified for the general and self-regulation factors of both versions. Overall, the findings provide strong support for the HPQ as a multi-informant, multidimensional measure of homework performance that has utility for the assessment of elementary and middle school students. (c) 2015 APA, all rights reserved).
Algamdi, Maaidah M; Hanneman, Sandra K
2018-02-14
Valid and reliable instruments in Arabic are needed to measure self-efficacy and quality of life for Arabic patients with cancer. The aim of this study was to test the psychometric performance of the Cancer Behavior Inventory-Brief Arabic (CBI-BA), including participant understanding of items, and the Functional Assessment of Cancer Therapy-Breast Arabic (FACT-BA). Using a cross-sectional design, 438 cancer patients completed the CBI-BA, 30 of whom completed cognitive interviews. A subsample 167 women with breast cancer also completed the FACT-BA. Internal consistency evidence was assessed with Cronbach's α and construct validity with principal axis factoring. Internal consistency estimates were acceptable for the total CBI-BA (α = .81) and FACT-BA (α = .88) scales. Exploratory factor analyses showed evidence of construct validity for the CBI-BA; 1 factor was derived, compared with four in the original English version. Cognitive interviews indicated satisfactory patient understanding of CBI-BA items. The Arabic version of the general FACT-General scale had 4 factors according to expectation. The CBI-BA has adequate psychometric performance for the measurement of self-efficacy for coping with cancer in Arabic patients. The FACT-General Arabic has adequate evidence of reliability and validity for the measurement of quality of life in Arabic women with breast cancer. The availability of culturally sensitive and psychometrically sound instruments for Arabic patients diagnosed with cancer should be valuable for healthcare clinicians and researchers to assess self-efficacy for coping with cancer and quality of life.
Mahoney, Alison E J; Hobbs, Megan J; Newby, Jill M; Williams, Alishia D; Sunderland, Matthew; Andrews, Gavin
2016-10-01
Understanding behavioral avoidance associated with generalized anxiety disorder (GAD) has implications for the classification, theoretical conceptualization, and clinical management of the disorder. This study describes the development and preliminary psychometric evaluation of a self-report measure of avoidant behaviors associated with GAD: the Worry Behaviors Inventory (WBI). The WBI was administered to treatment-seeking patients (N=1201). Convergent validity was assessed by correlating the WBI with measures of GAD symptom severity. Divergent validity was assessed by correlating the WBI with measures of general disability and measures of depression, social anxiety and panic disorder symptom severity. Exploratory and confirmatory factor analyses supported a two-factor structure (Safety Behaviors and Avoidance). Internal reliability was acceptable for the 10-item WBI scale (α=.86), Safety Behaviors (α=.85) and Avoidance subscales (α=.75). Evidence of convergent, divergent, and discriminant validity is reported. WBI subscales demonstrated differential associations with measures of symptom severity. The Safety Behaviors subscale was more strongly associated with GAD symptoms than symptoms of other disorders, whereas the Avoidance subscale was as strongly correlated with GAD severity as it was with depression, social anxiety and panic disorder severity. Structured diagnostic interviews were not conducted therefor validity analyses are limited to probable diagnoses based on self-report. The cross-sectional design precluded examination of the WBI's temporal stability and treatment sensitivity. Preliminary evidence supports the use of the WBI in research and clinical settings and may assist clinicians to identify behaviors that are theorized to maintain GAD and that can be targeted during psychological treatment. Copyright © 2016 Elsevier B.V. All rights reserved.
Crossing trend analysis methodology and application for Turkish rainfall records
NASA Astrophysics Data System (ADS)
Şen, Zekâi
2018-01-01
Trend analyses are the necessary tools for depicting possible general increase or decrease in a given time series. There are many versions of trend identification methodologies such as the Mann-Kendall trend test, Spearman's tau, Sen's slope, regression line, and Şen's innovative trend analysis. The literature has many papers about the use, cons and pros, and comparisons of these methodologies. In this paper, a completely new approach is proposed based on the crossing properties of a time series. It is suggested that the suitable trend from the centroid of the given time series should have the maximum number of crossings (total number of up-crossings or down-crossings). This approach is applicable whether the time series has dependent or independent structure and also without any dependence on the type of the probability distribution function. The validity of this method is presented through extensive Monte Carlo simulation technique and its comparison with other existing trend identification methodologies. The application of the methodology is presented for a set of annual daily extreme rainfall time series from different parts of Turkey and they have physically independent structure.
Perceptual load interacts with stimulus processing across sensory modalities.
Klemen, J; Büchel, C; Rose, M
2009-06-01
According to perceptual load theory, processing of task-irrelevant stimuli is limited by the perceptual load of a parallel attended task if both the task and the irrelevant stimuli are presented to the same sensory modality. However, it remains a matter of debate whether the same principles apply to cross-sensory perceptual load and, more generally, what form cross-sensory attentional modulation in early perceptual areas takes in humans. Here we addressed these questions using functional magnetic resonance imaging. Participants undertook an auditory one-back working memory task of low or high perceptual load, while concurrently viewing task-irrelevant images at one of three object visibility levels. The processing of the visual and auditory stimuli was measured in the lateral occipital cortex (LOC) and auditory cortex (AC), respectively. Cross-sensory interference with sensory processing was observed in both the LOC and AC, in accordance with previous results of unisensory perceptual load studies. The present neuroimaging results therefore warrant the extension of perceptual load theory from a unisensory to a cross-sensory context: a validation of this cross-sensory interference effect through behavioural measures would consolidate the findings.
Sotardi, Valerie A
2018-05-01
Educational measures of anxiety focus heavily on students' experiences with tests yet overlook other assessment contexts. In this research, two brief multiscale questionnaires were developed and validated to measure trait evaluation anxiety (MTEA-12) and state evaluation anxiety (MSEA-12) for use in various assessment contexts in non-clinical, educational settings. The research included a cross-sectional analysis of self-report data using authentic assessment settings in which evaluation anxiety was measured. Instruments were tested using a validation sample of 241 first-year university students in New Zealand. Scale development included component structures for state and trait scales based on existing theoretical frameworks. Analyses using confirmatory factor analysis and descriptive statistics indicate that the scales are reliable and structurally valid. Multivariate general linear modeling using subscales from the MTEA-12, MSEA-12, and student grades suggest adequate criterion-related validity. Initial predictive validity in which one relevant MTEA-12 factor explained between 21% and 54% of the variance in three MSEA-12 factors. Results document MTEA-12 and MSEA-12 as reliable measures of trait and state dimensions of evaluation anxiety for test and writing contexts. Initial estimates suggest the scales as having promising validity, and recommendations for further validation are outlined.
Arıkan, Hüseyin; Duman, Dildar; Kargın, Feyza; Ergin, Gülbin; Horne, Rob; Karakurt, Sait; Eryüksel, Emel
2018-01-01
OBJECTIVES Inadequate adaptation to long-term treatment of chronic illnesses is the most common reason for the inability to obtain the benefits medications can provide. Treatment compliance is influenced by several factors. Beliefs about Medicines Questionnaire (BMQ) developed by Horne et al. in 1999 to evaluate the cognitive representation of medicines have many validation studies, which resulted in good psychometric properties. The aim of the present study was to evaluate the reliability and validity of the BMQ Turkish translation in patients with asthma and chronic obstructive pulmonary disease (COPD). MATERIAL AND METHODS Fifty asthma and 50 COPD patients participated in this methodological study. The scale was adapted to Turkish through translation, comparison with other language versions, back translation, and a pre-test. The structural validity was assessed using factor analysis. RESULTS Similar to the original scale, factor analysis confirmed that BMQ had a four-factor structure that accounts for 58.23% of the total variance. The BMQ showed an acceptable internal consistency (Cronbach’s alpha coefficient: specific-necessity, 0.832: specific-concerns, 0.722; general-harm, 0.792; and general-overuse, 0.682). The factor analysis revealed the same patterns for all questions between the Turkish and original scales. CONCLUSION The psychometric properties of the BMQ were consistent with those reported in the original study. We found that the Turkish translation of BMQ is a valid and reliable tool for assessing medicine-related beliefs in patients with asthma and COPD. PMID:29404184
Arıkan, Hüseyin; Duman, Dildar; Kargın, Feyza; Ergin, Gülbin; Horne, Rob; Karakurt, Sait; Eryüksel, Emel
2018-01-01
Inadequate adaptation to long-term treatment of chronic illnesses is the most common reason for the inability to obtain the benefits medications can provide. Treatment compliance is influenced by several factors. Beliefs about Medicines Questionnaire (BMQ) developed by Horne et al. in 1999 to evaluate the cognitive representation of medicines have many validation studies, which resulted in good psychometric properties. The aim of the present study was to evaluate the reliability and validity of the BMQ Turkish translation in patients with asthma and chronic obstructive pulmonary disease (COPD). Fifty asthma and 50 COPD patients participated in this methodological study. The scale was adapted to Turkish through translation, comparison with other language versions, back translation, and a pre-test. The structural validity was assessed using factor analysis. Similar to the original scale, factor analysis confirmed that BMQ had a four-factor structure that accounts for 58.23% of the total variance. The BMQ showed an acceptable internal consistency (Cronbach's alpha coefficient: specific-necessity, 0.832: specific-concerns, 0.722; general-harm, 0.792; and general-overuse, 0.682). The factor analysis revealed the same patterns for all questions between the Turkish and original scales. The psychometric properties of the BMQ were consistent with those reported in the original study. We found that the Turkish translation of BMQ is a valid and reliable tool for assessing medicine-related beliefs in patients with asthma and COPD.
Żemojtel-Piotrowska, Magdalena; Piotrowski, Jarosław; Rogoza, Radosław; Baran, Tomasz; Hitokoto, Hidefumi; Maltby, John
2018-04-15
The current study explores the problem with the lack of measurement invariance for the Narcissistic Personality Inventory (NPI) by addressing two issues: conceptual heterogeneity of narcissism and methodological issues related to the binary character of data. We examine the measurement invariance of the 13-item version of the NPI in three populations in Japan, Poland and the UK. Analyses revealed that leadership/authority and grandiose exhibitionism dimensions of the NPI were cross-culturally invariant, while entitlement/exploitativeness was culturally specific. Therefore, we proposed NPI-9 as indicating scalar invariance, and we examined the pattern of correlations between NPI-9 and other variables across three countries. The results suggest that NPI-9 is valid brief scale measuring general levels of narcissism in cross-cultural studies, while the NPI-13 remains suitable for research within specific countries. © 2018 International Union of Psychological Science.
2D data-space cross-gradient joint inversion of MT, gravity and magnetic data
NASA Astrophysics Data System (ADS)
Pak, Yong-Chol; Li, Tonglin; Kim, Gang-Sop
2017-08-01
We have developed a data-space multiple cross-gradient joint inversion algorithm, and validated it through synthetic tests and applied it to magnetotelluric (MT), gravity and magnetic datasets acquired along a 95 km profile in Benxi-Ji'an area of northeastern China. To begin, we discuss a generalized cross-gradient joint inversion for multiple datasets and model parameters sets, and formulate it in data space. The Lagrange multiplier required for the structural coupling in the data-space method is determined using an iterative solver to avoid calculation of the inverse matrix in solving the large system of equations. Next, using model-space and data-space methods, we inverted the synthetic data and field data. Based on our result, the joint inversion in data-space not only delineates geological bodies more clearly than the separate inversion, but also yields nearly equal results with the one in model-space while consuming much less memory.
Hill, Mary C.; L. Foglia,; S. W. Mehl,; P. Burlando,
2013-01-01
Model adequacy is evaluated with alternative models rated using model selection criteria (AICc, BIC, and KIC) and three other statistics. Model selection criteria are tested with cross-validation experiments and insights for using alternative models to evaluate model structural adequacy are provided. The study is conducted using the computer codes UCODE_2005 and MMA (MultiModel Analysis). One recharge alternative is simulated using the TOPKAPI hydrological model. The predictions evaluated include eight heads and three flows located where ecological consequences and model precision are of concern. Cross-validation is used to obtain measures of prediction accuracy. Sixty-four models were designed deterministically and differ in representation of river, recharge, bedrock topography, and hydraulic conductivity. Results include: (1) What may seem like inconsequential choices in model construction may be important to predictions. Analysis of predictions from alternative models is advised. (2) None of the model selection criteria consistently identified models with more accurate predictions. This is a disturbing result that suggests to reconsider the utility of model selection criteria, and/or the cross-validation measures used in this work to measure model accuracy. (3) KIC displayed poor performance for the present regression problems; theoretical considerations suggest that difficulties are associated with wide variations in the sensitivity term of KIC resulting from the models being nonlinear and the problems being ill-posed due to parameter correlations and insensitivity. The other criteria performed somewhat better, and similarly to each other. (4) Quantities with high leverage are more difficult to predict. The results are expected to be generally applicable to models of environmental systems.
Piette, Elizabeth R; Moore, Jason H
2018-01-01
Machine learning methods and conventions are increasingly employed for the analysis of large, complex biomedical data sets, including genome-wide association studies (GWAS). Reproducibility of machine learning analyses of GWAS can be hampered by biological and statistical factors, particularly so for the investigation of non-additive genetic interactions. Application of traditional cross validation to a GWAS data set may result in poor consistency between the training and testing data set splits due to an imbalance of the interaction genotypes relative to the data as a whole. We propose a new cross validation method, proportional instance cross validation (PICV), that preserves the original distribution of an independent variable when splitting the data set into training and testing partitions. We apply PICV to simulated GWAS data with epistatic interactions of varying minor allele frequencies and prevalences and compare performance to that of a traditional cross validation procedure in which individuals are randomly allocated to training and testing partitions. Sensitivity and positive predictive value are significantly improved across all tested scenarios for PICV compared to traditional cross validation. We also apply PICV to GWAS data from a study of primary open-angle glaucoma to investigate a previously-reported interaction, which fails to significantly replicate; PICV however improves the consistency of testing and training results. Application of traditional machine learning procedures to biomedical data may require modifications to better suit intrinsic characteristics of the data, such as the potential for highly imbalanced genotype distributions in the case of epistasis detection. The reproducibility of genetic interaction findings can be improved by considering this variable imbalance in cross validation implementation, such as with PICV. This approach may be extended to problems in other domains in which imbalanced variable distributions are a concern.
Generalized Cross Entropy Method for estimating joint distribution from incomplete information
NASA Astrophysics Data System (ADS)
Xu, Hai-Yan; Kuo, Shyh-Hao; Li, Guoqi; Legara, Erika Fille T.; Zhao, Daxuan; Monterola, Christopher P.
2016-07-01
Obtaining a full joint distribution from individual marginal distributions with incomplete information is a non-trivial task that continues to challenge researchers from various domains including economics, demography, and statistics. In this work, we develop a new methodology referred to as ;Generalized Cross Entropy Method; (GCEM) that is aimed at addressing the issue. The objective function is proposed to be a weighted sum of divergences between joint distributions and various references. We show that the solution of the GCEM is unique and global optimal. Furthermore, we illustrate the applicability and validity of the method by utilizing it to recover the joint distribution of a household profile of a given administrative region. In particular, we estimate the joint distribution of the household size, household dwelling type, and household home ownership in Singapore. Results show a high-accuracy estimation of the full joint distribution of the household profile under study. Finally, the impact of constraints and weight on the estimation of joint distribution is explored.
Exact Analysis of Squared Cross-Validity Coefficient in Predictive Regression Models
ERIC Educational Resources Information Center
Shieh, Gwowen
2009-01-01
In regression analysis, the notion of population validity is of theoretical interest for describing the usefulness of the underlying regression model, whereas the presumably more important concept of population cross-validity represents the predictive effectiveness for the regression equation in future research. It appears that the inference…
Van Iddekinge, Chad H; Putka, Dan J; Campbell, John P
2011-01-01
Although vocational interests have a long history in vocational psychology, they have received extremely limited attention within the recent personnel selection literature. We reconsider some widely held beliefs concerning the (low) validity of interests for predicting criteria important to selection researchers, and we review theory and empirical evidence that challenge such beliefs. We then describe the development and validation of an interests-based selection measure. Results of a large validation study (N = 418) reveal that interests predicted a diverse set of criteria—including measures of job knowledge, job performance, and continuance intentions—with corrected, cross-validated Rs that ranged from .25 to .46 across the criteria (mean R = .31). Interests also provided incremental validity beyond measures of general cognitive aptitude and facets of the Big Five personality dimensions in relation to each criterion. Furthermore, with a couple exceptions, the interest scales were associated with small to medium subgroup differences, which in most cases favored women and racial minorities. Taken as a whole, these results appear to call into question the prevailing thought that vocational interests have limited usefulness for selection.
Scaled plane-wave Born cross sections for atoms and molecules
NASA Astrophysics Data System (ADS)
Tanaka, H.; Brunger, M. J.; Campbell, L.; Kato, H.; Hoshino, M.; Rau, A. R. P.
2016-04-01
Integral cross sections for optically allowed electronic-state excitations of atoms and molecules by electron impact, by applying scaled plane-wave Born models, are reviewed. Over 40 years ago, Inokuti presented an influential review of charged-particle scattering, based on the theory pioneered by Bethe forty years earlier, which emphasized the importance of reliable cross-section data from low eV energies to high keV energies that are needed in many areas of radiation science with applications to astronomy, plasmas, and medicine. Yet, with a couple of possible exceptions, most computational methods in electron-atom scattering do not, in general, overlap each other's validity range in the region from threshold up to 300 eV and, in particular, in the intermediate region from 30 to 300 eV. This is even more so for electron-molecule scattering. In fact this entire energy range is of great importance and, to bridge the gap between the two regions of low and high energy, scaled plane-wave Born models were developed to provide reliable, comprehensive, and absolute integral cross sections, first for ionization by Kim and Rudd and then extended to optically allowed electronic-state excitation by Kim. These and other scaling models in a broad, general application to electron scattering from atoms and molecules, their theoretical basis, and their results for cross sections along with comparison to experimental measurements are reviewed. Where possible, these data are also compared to results from other computational approaches.
Matrix cracking in laminated composites under monotonic and cyclic loadings
NASA Technical Reports Server (NTRS)
Allen, David H.; Lee, Jong-Won
1991-01-01
An analytical model based on the internal state variable (ISV) concept and the strain energy method is proposed for characterizing the monotonic and cyclic response of laminated composites containing matrix cracks. A modified constitution is formulated for angle-ply laminates under general in-plane mechanical loading and constant temperature change. A monotonic matrix cracking criterion is developed for predicting the crack density in cross-ply laminates as a function of the applied laminate axial stress. An initial formulation for a cyclic matrix cracking criterion for cross-ply laminates is also discussed. For the monotonic loading case, a number of experimental data and well-known models are compared with the present study for validating the practical applicability of the ISV approach.
Guidelines To Validate Control of Cross-Contamination during Washing of Fresh-Cut Leafy Vegetables.
Gombas, D; Luo, Y; Brennan, J; Shergill, G; Petran, R; Walsh, R; Hau, H; Khurana, K; Zomorodi, B; Rosen, J; Varley, R; Deng, K
2017-02-01
The U.S. Food and Drug Administration requires food processors to implement and validate processes that will result in significantly minimizing or preventing the occurrence of hazards that are reasonably foreseeable in food production. During production of fresh-cut leafy vegetables, microbial contamination that may be present on the product can spread throughout the production batch when the product is washed, thus increasing the risk of illnesses. The use of antimicrobials in the wash water is a critical step in preventing such water-mediated cross-contamination; however, many factors can affect antimicrobial efficacy in the production of fresh-cut leafy vegetables, and the procedures for validating this key preventive control have not been articulated. Producers may consider three options for validating antimicrobial washing as a preventive control for cross-contamination. Option 1 involves the use of a surrogate for the microbial hazard and the demonstration that cross-contamination is prevented by the antimicrobial wash. Option 2 involves the use of antimicrobial sensors and the demonstration that a critical antimicrobial level is maintained during worst-case operating conditions. Option 3 validates the placement of the sensors in the processing equipment with the demonstration that a critical antimicrobial level is maintained at all locations, regardless of operating conditions. These validation options developed for fresh-cut leafy vegetables may serve as examples for validating processes that prevent cross-contamination during washing of other fresh produce commodities.
Castellví, Pere; Forero, Carlos G; Codony, Miquel; Vilagut, Gemma; Brugulat, Pilar; Medina, Antonia; Gabilondo, Andrea; Mompart, Anna; Colom, Joan; Tresserras, Ricard; Ferrer, Montse; Stewart-Brown, Sarah; Alonso, Jordi
2014-04-01
Mental well-being has aroused interest in Europe as an indicator of population health. The Warwick-Edinburgh Mental Well-Being Scale (WEMWBS) was developed in the United Kingdom showing good face validity and has been previously adapted into Spanish. The aim of this study is to assess the validity and reliability of the Spanish version of WEMWBS in the general population. Cross-sectional home face-to-face interview survey with computer-assisted personal interviewing was administered with the 2011 Catalan Health Interview Survey Wave 3, which is representative of the non-institutionalized general population of Catalonia, Spain. A total of 1,900 participants 15+ years of age were interviewed. The Spanish version of WEMWBS was administered together with socioeconomic and health-related variables, with a hypothesized level of association. Similar to the original, confirmatory factor analysis fits a one-factor model adequately (CFI = 0.974; TLI = 0.970; RMSEA = 0.059; χ (2) = 584.82; df = 77; p < .001) and has a high internal consistency (Cronbach's alpha = 0.930; Guttman's lambda 2 = 0.932). The WEMWBS discriminated between population groups in all health-related and socioeconomic variables, except in gender (p = 0.119), with a magnitude similar to that hypothesized. Overall, mental well-being was higher for the general population of Catalonia (average and whole distribution) than that for Scotland general population. The Spanish version of WEMWBS showed good psychometric properties similar to the UK original scale. Whether better mental well-being in Catalonia is due to methodological or substantive cultural, social, or environmental factors should be further researched.
Reliable Digit Span: A Systematic Review and Cross-Validation Study
ERIC Educational Resources Information Center
Schroeder, Ryan W.; Twumasi-Ankrah, Philip; Baade, Lyle E.; Marshall, Paul S.
2012-01-01
Reliable Digit Span (RDS) is a heavily researched symptom validity test with a recent literature review yielding more than 20 studies ranging in dates from 1994 to 2011. Unfortunately, limitations within some of the research minimize clinical generalizability. This systematic review and cross-validation study was conducted to address these…
NASA Astrophysics Data System (ADS)
Steger, Stefan; Brenning, Alexander; Bell, Rainer; Glade, Thomas
2016-12-01
There is unanimous agreement that a precise spatial representation of past landslide occurrences is a prerequisite to produce high quality statistical landslide susceptibility models. Even though perfectly accurate landslide inventories rarely exist, investigations of how landslide inventory-based errors propagate into subsequent statistical landslide susceptibility models are scarce. The main objective of this research was to systematically examine whether and how inventory-based positional inaccuracies of different magnitudes influence modelled relationships, validation results, variable importance and the visual appearance of landslide susceptibility maps. The study was conducted for a landslide-prone site located in the districts of Amstetten and Waidhofen an der Ybbs, eastern Austria, where an earth-slide point inventory was available. The methodological approach comprised an artificial introduction of inventory-based positional errors into the present landslide data set and an in-depth evaluation of subsequent modelling results. Positional errors were introduced by artificially changing the original landslide position by a mean distance of 5, 10, 20, 50 and 120 m. The resulting differently precise response variables were separately used to train logistic regression models. Odds ratios of predictor variables provided insights into modelled relationships. Cross-validation and spatial cross-validation enabled an assessment of predictive performances and permutation-based variable importance. All analyses were additionally carried out with synthetically generated data sets to further verify the findings under rather controlled conditions. The results revealed that an increasing positional inventory-based error was generally related to increasing distortions of modelling and validation results. However, the findings also highlighted that interdependencies between inventory-based spatial inaccuracies and statistical landslide susceptibility models are complex. The systematic comparisons of 12 models provided valuable evidence that the respective error-propagation was not only determined by the degree of positional inaccuracy inherent in the landslide data, but also by the spatial representation of landslides and the environment, landslide magnitude, the characteristics of the study area, the selected classification method and an interplay of predictors within multiple variable models. Based on the results, we deduced that a direct propagation of minor to moderate inventory-based positional errors into modelling results can be partly counteracted by adapting the modelling design (e.g. generalization of input data, opting for strongly generalizing classifiers). Since positional errors within landslide inventories are common and subsequent modelling and validation results are likely to be distorted, the potential existence of inventory-based positional inaccuracies should always be considered when assessing landslide susceptibility by means of empirical models.
Landscape scale estimation of soil carbon stock using 3D modelling.
Veronesi, F; Corstanje, R; Mayr, T
2014-07-15
Soil C is the largest pool of carbon in the terrestrial biosphere, and yet the processes of C accumulation, transformation and loss are poorly accounted for. This, in part, is due to the fact that soil C is not uniformly distributed through the soil depth profile and most current landscape level predictions of C do not adequately account the vertical distribution of soil C. In this study, we apply a method based on simple soil specific depth functions to map the soil C stock in three-dimensions at landscape scale. We used soil C and bulk density data from the Soil Survey for England and Wales to map an area in the West Midlands region of approximately 13,948 km(2). We applied a method which describes the variation through the soil profile and interpolates this across the landscape using well established soil drivers such as relief, land cover and geology. The results indicate that this mapping method can effectively reproduce the observed variation in the soil profiles samples. The mapping results were validated using cross validation and an independent validation. The cross-validation resulted in an R(2) of 36% for soil C and 44% for BULKD. These results are generally in line with previous validated studies. In addition, an independent validation was undertaken, comparing the predictions against the National Soil Inventory (NSI) dataset. The majority of the residuals of this validation are between ± 5% of soil C. This indicates high level of accuracy in replicating topsoil values. In addition, the results were compared to a previous study estimating the carbon stock of the UK. We discuss the implications of our results within the context of soil C loss factors such as erosion and the impact on regional C process models. Copyright © 2014 Elsevier B.V. All rights reserved.
Haji Ali Afzali, Hossein; Gray, Jodi; Karnon, Jonathan
2013-04-01
Decision analytic models play an increasingly important role in the economic evaluation of health technologies. Given uncertainties around the assumptions used to develop such models, several guidelines have been published to identify and assess 'best practice' in the model development process, including general modelling approach (e.g., time horizon), model structure, input data and model performance evaluation. This paper focuses on model performance evaluation. In the absence of a sufficient level of detail around model performance evaluation, concerns regarding the accuracy of model outputs, and hence the credibility of such models, are frequently raised. Following presentation of its components, a review of the application and reporting of model performance evaluation is presented. Taking cardiovascular disease as an illustrative example, the review investigates the use of face validity, internal validity, external validity, and cross model validity. As a part of the performance evaluation process, model calibration is also discussed and its use in applied studies investigated. The review found that the application and reporting of model performance evaluation across 81 studies of treatment for cardiovascular disease was variable. Cross-model validation was reported in 55 % of the reviewed studies, though the level of detail provided varied considerably. We found that very few studies documented other types of validity, and only 6 % of the reviewed articles reported a calibration process. Considering the above findings, we propose a comprehensive model performance evaluation framework (checklist), informed by a review of best-practice guidelines. This framework provides a basis for more accurate and consistent documentation of model performance evaluation. This will improve the peer review process and the comparability of modelling studies. Recognising the fundamental role of decision analytic models in informing public funding decisions, the proposed framework should usefully inform guidelines for preparing submissions to reimbursement bodies.
Kyrölä, Kati; Järvenpää, Salme; Ylinen, Jari; Mecklin, Jukka-Pekka; Repo, Jussi Petteri; Häkkinen, Arja
2017-06-15
A prospective clinical study to test and adapt a Finnish version of the Scoliosis Research Society 30 (SRS-30) questionnaire. The aim of this study was to perform cross-cultural adaptation and evaluate the validity of the adapted Finnish version of the SRS-30 questionnaire. The SRS-30 questionnaire has proved to be a valid instrument in evaluating health-related quality of life (HRQoL) in adolescent and adult population with spine deformities in the United States. Multinational availability requires cross-cultural and linguistic adaptation and validation of the instrument. The SRS-30 was translated into Finnish using accepted methods for translation of quality-of-life questionnaires. A total of 274 adult patients with degenerative radiographic sagittal spinal disorder answered the questionnaire with sociodemographic data, RAND 36-item health survey questionnaire (RAND Corp. Health, Santa Monica, CA, US), Oswestry disability index, DEPS depression scale, and Visual Analog Scale (VAS) back and leg pain scales within 2 weeks' interval. The cohort included patients with and without previous spine surgery. Internal consistency and validity were tested with Cronbach α, intraclass correlation (ICC), standard error of measurement, and Spearman correlation coefficient with 95% confidence intervals (CIs). The internal consistency of SRS-30 was good in both surgery and nonsurgery groups, with Cronbach α 0.853 (95% CI, 0.670 to 0.960) and 0.885 (95% CI, 0.854 to 0.911), respectively. The test-retest reproducibility ICC of the SRS-30 total and subscore domains of patients with stable symptoms was 0.905 (95% CI, 0.870-0.930) and 0.904 (95% CI, 0.871-0.929), respectively. The questionnaire had discriminative validity in the pain, self-image, and satisfaction with management domains compared with other questionnaires. The SRS-30 questionnaire proved to be valid and applicable in evaluating HRQoL in Finnish adult spinal deformity patients. It has two domains related to deformity that are not covered by other generally used questionnaires. 3.
Identifying dyspepsia in the Greek population: translation and validation of a questionnaire
Anastasiou, Foteini; Antonakis, Nikos; Chaireti, Georgia; Theodorakis, Pavlos N; Lionis, Christos
2006-01-01
Background Studies on clinical issues, including diagnostic strategies, are considered to be the core content of general practice research. The use of standardised instruments is regarded as an important component for the development of Primary Health Care research capacity. Demand for epidemiological cross-cultural comparisons in the international setting and the use of common instruments and definitions valid to each culture is bigger than ever. Dyspepsia is a common complaint in primary practice but little is known with respect to its incidence in Greece. There are some references about the Helicobacter Pylori infection in patients with functional dyspepsia or gastric ulcer in Greece but there is no specific instrument for the identification of dyspepsia. This paper reports on the validation and translation into Greek, of an English questionnaire for the identification of dyspepsia in the general population and discusses several possibilities of its use in the Greek primary care. Methods The selected English postal questionnaire for the identification of people with dyspepsia in the general population consists of 30 items and was developed in 1995. The translation and cultural adaptation of the questionnaire has been performed according to international standards. For the validation of the instrument the internal consistency of the items was established using the alpha coefficient of Chronbach, the reproducibility (test – retest reliability) was measured by kappa correlation coefficient and the criterion validity was calculated against the diagnosis of the patients' records using also kappa correlation coefficient. Results The final Greek version of the postal questionnaire for the identification of dyspepsia in the general population was reliably translated. The internal consistency of the questionnaire was good, Chronbach's alpha was found to be 0.88 (95% CI: 0.81–0.93), suggesting that all items were appropriate to measure. Kappa coefficient for reproducibility (test – retest reliability) was found 0.66 (95% CI: 0.62–0.71), whereas the kappa analysis for criterion validity was 0.63 (95% CI: 0.36–0.89). Conclusion This study indicates that the Greek translation is comparable with the English-language version in terms of validity and reliability, and is suitable for epidemiological research within the Greek primary health care setting. PMID:16515708
Kono, Ayumi; Tadaka, Etsuko; Kanaya, Yukiko; Dai, Yuka; Itoi, Waka; Imamatsu, Yuki
2012-10-24
Elderly social isolation could be prevented by facilitating communication or mutual helping at the neighborhood level. The helping of elderly neighbors by local volunteers may relate to their community commitment (CC), but ways to measure CC have not been identified. The aim of the present study was to develop a Community Commitment Scale (CCS) to measure psychological sense of belonging and socializing in the community among local volunteers, for research in prevention of elderly social isolation. We also tested the CCS in a general population of the elderly. A pilot test of 266 Japanese urban residents was conducted to examine face validity for 24 identified items, of which 12 items were selected for the CCS, based on a 4-point Likert-type scale. The CCS was developed via self-report questionnaires to 859 local volunteers in two suburban cities and to 3484 randomly sampled general residents aged 55 years or older living in one of the cities. To assess concurrent validity, data were collected using the Brief Sense of Community Scale (Peterson; 2008) and two types of single questions on self-efficacy for helping elderly neighbors. Item analysis and factor analysis identified 8 items, which were classified between two datasets under the domains of "belonging" and "socializing" in the local volunteers and the general residents. Cronbach's alpha (which conveyed the internal consistency of the CCS) was 0.75 in local volunteers and 0.78 in general residents. The correlation coefficients between the scores of the CCS and BSCS were 0.54 for local volunteers and 0.62 for general residents. ANOVA comparing the CCS between the confidence levels of the two types of single question of self-efficacy on helping elderly neighbors showed a strong relationship in the volunteers and residents. These results demonstrate acceptable internal consistency and concurrent validity for the CCS, with the two dimensions "belonging" and "socializing", among the local volunteers and general residents in urban Japanese areas. Community commitment measured by the CCS was related to the degree of confidence for self-efficacy in helping elderly neighbors to prevent elderly social isolation.
Pelegrino, Flávia M; Dantas, Rosana A S; Corbi, Inaiara S A; da Silva Carvalho, Ariana R; Schmidt, André; Pazin Filho, Antônio
2012-09-01
The aim of this study was to evaluate the internal reliability and validity of the Brazilian-Portuguese version of Duke Anticoagulation Satisfaction Scale (DASS) among cardiovascular patients. Oral anticoagulation is widely used to prevent and treat thromboembolic events in several conditions, especially in cardiovascular diseases; however, this therapy can induce dissatisfaction and reduce the quality of life. Methodological and cross-sectional research design. The cultural adaptation of the DASS included the translation and back-translation, discussions with healthcare professionals and patients to ensure conceptual equivalence, semantic evaluation and instrument pretest. The Brazilian-Portuguese version of the DASS was tested among subjects followed in a university hospital anticoagulation outpatient clinic. The psychometric properties were assessed by construct validity (convergent, known groups and dimensionality) and internal consistency/reliability (Cronbach's alpha). A total of 180 subjects under oral anticoagulation formed the baseline validation population. DASS total score and SF-36 domain correlations were moderate for General health (r=-0.47, p<0.01), Vitality (r=-0.44, p<0.01) and Mental health (r=-0.42, p<0.01) (convergent). Age and length on oral anticoagulation therapy (in years) were weakly correlated with total DASS score and most of the subscales, except Limitation (r=-0.375, p<0.01) (Known groups). The Cronbach's alpha coefficient was 0.79 for the total scale, and it ranged from 0.76 (hassles and burdens)-0.46 (psychological impact) among the domains, confirming the internal consistency reliability. The Brazilian-Portuguese version of the DASS has shown levels of reliability and validity comparable with the original English version. Healthcare practitioners and researchers need internationally validated measurement tools to compare outcomes of interventions in clinical management and research tools in oral anticoagulation therapy. © 2011 Blackwell Publishing Ltd.
Leung, Ying Ying; Lee, Weixian; Lui, Nai Lee; Rouse, Matthew; McKenna, Stephen P; Thumboo, Julian
2017-08-17
To cross-culturally adapt and validate the Singapore Chinese and Singapore English versions of the Ankylosing Spondylitis Quality of Life (ASQoL) scales. Translation of the ASQoL into Singapore Chinese and English was performed by professional and lay translation panels. Field-testing for face and content validity was performed by interviewing ten Chinese speaking and ten English speaking axial spondyloarthritis (AxSpA) patients. AxSpA patients (either Chinese or English speaking) were invited to take part in validation surveys. The Health Assessment Questionnaire (HAQ), Short Form Health Survey (SF-36), Bath Indices, and other measures of disease activity were used as comparator scales for convergent validity. A separate sample of AxSpA patients were invited to participate in a test-retest postal study, with 2 weeks between administrations. The cross-sectional study included 183 patients (77% males, 82% English speaking), with a mean (SD) age of 39.4 (13.7) years. The ASQoL had excellent internal consistency (Cronbach's alpha = 0.88), and correlated moderately with all the comparator scales. The ASQoL was able to distinguish between patients grouped by disease activity and perceived general health. The ASQoL fulfilled the Rasch model analysis for fit, reliability and unidimensionality requirements. No significant differential item functioning was noted for gender, age below or above 50 years, and language of administration. Test-retest reliability was good (r = 0.81). The ASQoL was adapted into Singapore Chinese and English language versions, and shown to be culturally relevant, valid and reliable when used with combined samples of AxSpA patients who speak either Chinese or English.
ERIC Educational Resources Information Center
Jordans, M. J. D.; Komproe, I. H.; Tol, W. A.; De Jong, J. T. V. M.
2009-01-01
Background: Large-scale psychosocial interventions in complex emergencies call for a screening procedure to identify individuals at risk. To date there are no screening instruments that are developed within low- and middle-income countries and validated for that purpose. The present study assesses the cross-cultural validity of the brief,…
Decorrelation of the true and estimated classifier errors in high-dimensional settings.
Hanczar, Blaise; Hua, Jianping; Dougherty, Edward R
2007-01-01
The aim of many microarray experiments is to build discriminatory diagnosis and prognosis models. Given the huge number of features and the small number of examples, model validity which refers to the precision of error estimation is a critical issue. Previous studies have addressed this issue via the deviation distribution (estimated error minus true error), in particular, the deterioration of cross-validation precision in high-dimensional settings where feature selection is used to mitigate the peaking phenomenon (overfitting). Because classifier design is based upon random samples, both the true and estimated errors are sample-dependent random variables, and one would expect a loss of precision if the estimated and true errors are not well correlated, so that natural questions arise as to the degree of correlation and the manner in which lack of correlation impacts error estimation. We demonstrate the effect of correlation on error precision via a decomposition of the variance of the deviation distribution, observe that the correlation is often severely decreased in high-dimensional settings, and show that the effect of high dimensionality on error estimation tends to result more from its decorrelating effects than from its impact on the variance of the estimated error. We consider the correlation between the true and estimated errors under different experimental conditions using both synthetic and real data, several feature-selection methods, different classification rules, and three error estimators commonly used (leave-one-out cross-validation, k-fold cross-validation, and .632 bootstrap). Moreover, three scenarios are considered: (1) feature selection, (2) known-feature set, and (3) all features. Only the first is of practical interest; however, the other two are needed for comparison purposes. We will observe that the true and estimated errors tend to be much more correlated in the case of a known feature set than with either feature selection or using all features, with the better correlation between the latter two showing no general trend, but differing for different models.
2012-01-01
Background Currently, no validated instruments are available to measure the health status of Bangladeshi patients with fibromyalgia (FM). The aims of this study were to cross-culturally adapt the modified Fibromyalgia Impact Questionnaire (FIQ) into Bengali (B-FIQ) and to test its validity and reliability in Bangladeshi patients with FM. Methods The FIQ was translated following cross-cultural adaptation guidelines and pretested in 30 female patients with FM. Next, the adapted B-FIQ was physician-administered to 102 consecutive female FM patients together with the Health Assessment Questionnaire (HAQ), selected subscales of the SF-36, and visual analog scales for current clinical symptoms. A tender point count (TPC) was performed by an experienced rheumatologist. Forty randomly selected patients completed the B-FIQ again after 7 days. Two control groups of 50 healthy people and 50 rheumatoid arthritis (RA) patients also completed the B-FIQ. Results For the final B-FIQ, five physical function sub-items were replaced with culturally appropriate equivalents. Internal consistency was adequate for both the 11-item physical function subscale (α = 0.73) and the total scale (α = 0.83). With exception of the physical function subscale, expected correlations were generally observed between the B-FIQ items and selected subscales of the SF-36, HAQ, clinical symptoms, and TPC. The B-FIQ was able to discriminate between FM patients and healthy controls and between FM patients and RA patients. Test-retest reliability was adequate for the physical function subscale (r = 0.86) and individual items (r = 0.73-0.86), except anxiety (r = 0.27) and morning tiredness (r = 0.64). Conclusion This study supports the reliability and validity of the B-FIQ as a measure of functional disability and health status in Bangladeshi women with FM. PMID:22925458
Cui, Xuelian; Niu, Wei; Kong, Lingming; He, Mingjun; Jiang, Kunhong; Chen, Shengdong; Zhong, Aifang; Li, Wanshuai; Lu, Jim; Zhang, Liyi
2017-06-01
Depression and anxiety are apparent symptoms in the early onset or acute phase of schizophrenia (SZ), which complicate timely diagnosis and treatment. It is imperative to seek an indicator to distinguish schizophrenia from depressive and anxiety disorders. Using lncRNA microarray profiling and RT-PCR, three up-regulated lncRNAs in SZ, six down-regulated lncRNAs in major depressive disorder (MDD), and three up-regulated lncRNAs in generalized anxiety disorder (GAD) had been identified as potential biomarkers. All the lncRNAs were, then, cross-validated in 40 SZ patients, 40 MDD patients, 40 GAD patients, and 40 normal controls. Compared with controls, three up-regulated SZ lncRNAs had a significantly down-regulated expression in GAD, and no remarkable differences existed between MDD and the controls. Additionally, the six down-regulated MDD lncRNAs were expressed in an opposite fashion in SZ, and the expression of the three up-regulated GAD lncRNAs were significantly different between SZ and GAD. These results indicate that the expression patterns of the three up-regulated SZ lncRNAs could not be completely replicated in MDD and GAD, and vice versa. Thus, these three SZ lncRNAs seem to be established as potential indicators for diagnosis of schizophrenia and distinguishing it from MDD and GAD. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
The Validity and Reliability of the Turkish Version of the Neonatal Skin Risk Assessment Scale.
Sari, Çiğdem; Altay, Naime
2017-03-01
The study created a Turkish translation of the Neonatal Skin Risk Assessment Scale (NSRAS) that was developed by Huffines and Longsdon in 1997. Study authors used a cross-sectional survey design in order to determine the validity and reliability of the Turkish translation. The study was conducted at the neonatal intensive care unit of a university hospital in Ankara between March 15 and June 30, 2014. The research sample included 130 neonatal assessments from 17 patients. Data were collected by questionnaire regarding the characteristics of the participating neonates, 7 nurse observers, and the NSRAS and its subarticles. After translation and back-translation were performed to assess language validity of the scale, necessary corrections were made in line with expert suggestions, and content validity was ensured. Internal consistency of the scale was assessed by its homogeneity, Cronbach's α, and subarticle-general scale grade correlation. Cronbach's α for the scale overall was .88, and Cronbach's α values for the subarticles were between .83 and .90. Results showed a positive relationship among all the subarticles and the overall NSRAS scale grade (P < .01) with correlation values between 0.333 and 0.721. Explanatory and predicative factor analysis was applied for structural validity. Kaiser-Meyer-Olkin analysis was applied for sample sufficiency, and Bartlett test analysis was applied in order to assess the factor analysis of the sample. The Kaiser-Meyer-Olkin coefficient was 0.73, and the χ value found according to the Bartlett test was statistically significant at an advanced level (P < .05). In the 6 subarticles of the scale and in the general scale total grade, a high, positive, and significant relationship among the grades given by the researcher and the nurse observers was found (P < .05). The Turkish NSRAS is reliable and valid.
Sobral, Maria P; Costa, Maria E; Schmidt, Lone; Martins, Mariana V
2017-02-01
Are the Copenhagen Multi-Centre Psychosocial Infertility research program Fertility Problem Stress Scales (COMPI-FPSS) a reliable and valid measure across gender and culture? The COMPI-FPSS is a valid and reliable measure, presenting excellent or good fit in the majority of the analyzed countries, and demonstrating full invariance across genders and partial invariance across cultures. Cross-cultural and gender validation is needed to consider a measure as standard care within fertility. The present study is the first attempting to establish comparability of fertility-related stress across genders and countries. Cross-sectional study. First, we tested the structure of the COMPI-FPSS. Then, reliability and validity (convergent and discriminant) were examined for the final model. Finally, measurement invariance both across genders and cultures was tested. Our final sample had 3923 fertility patients (1691 men and 2232 women) recruited in clinical settings from seven different countries: Denmark, China, Croatia, Germany, Greece, Hungary and Sweden. Participants had a mean age of 34 years and the majority (84%) were childless. Findings confirmed the original three-factor structure of the COMPI-FPSS, although suggesting a shortened measurement model using less items that fitted the data better than the full version model. While data from the Chinese and Croatian subsamples did not fit, all other counties presented good fit (χ 2 /df ≤ 5.4; comparative fit index ≥ 0.94; root-mean-square error of approximation ≤ 0.07; modified expected cross-validation index ≤ 0.77). In general, reliability, convergent validity, and discriminant validity were observed in all subscales from each country (composite reliability ≥ 0.63; average variance extracted ≥ 0.38; squared correlation ≥ 0.13). Full invariance was established across genders, and partial invariance was demonstrated across countries. Generalizability regarding the validation of the COMPI-FPSS cannot be made regarding infertile individuals not seeking treatment, or non-European patients. This study did not investigate predictive validity, and hence the capability of this instrument in detecting changes in fertility-specific adjustment over time and predicting the psychological impact needs to be established in future research. Besides extending knowledge on the psychometric properties of one of the most used fertility stress questionnaire, this study demonstrates both research and clinical usefulness of the COMPI-FPSS. This study was supported by European Union Funds (FEDER/COMPETE-Operational Competitiveness Program, and by national funds (FCT-Portuguese Foundation for Science and Technology) under the projects PTDC/MHC-PSC/4195/2012 and SFRH/BPD/85789/2012). There are no conflicts of interest to declare. N/A. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Tuomikoski, Anna-Maria; Ruotsalainen, Heidi; Mikkonen, Kristina; Miettunen, Jouko; Kääriäinen, Maria
2018-06-05
Mentors require competence at a diverse array of skills to mentor students during clinical practice. According to the latest evidence, competence at mentoring includes: knowledge, skills and attributes of individual students' learning objectives, core elements of nursing, learning processes, a reciprocal and trustful relationship, feedback, evaluation, cooperation with stakeholders, and the mentor's personal qualities. The purpose of the study was to test psychometric properties of a mentor's competence instrument developed to self-evaluate mentors' competence at mentoring nursing students in clinical practice. A cross-sectional, descriptive, explorative study design was used. Data were collected from mentors at five university hospitals in Finland in 2016. A total of 576 mentors participated in this study. The instrument was developed through systematic review, experts' evaluations, and pilot versions of the instrument tested in previous studies. The construct validity and reliability of the instrument were tested using exploratory factor analysis (EFA) with promax rotation and Cronbach's alpha. A 10-factor model showed that the instrument has acceptable construct validity. Cronbach's alpha values for the subscales observed ranged from 0.76 to 0.90. The instrument exhibited acceptable psychometric properties, thereby proving itself a valuable tool for evaluating mentors' competence at mentoring students. Further assessments of its reliability, validity and generality for measuring mentor's competence for mentoring students in different contexts and cultures are recommended. Copyright © 2018 Elsevier Ltd. All rights reserved.
Bahl, Gautam; Cruite, Irene; Wolfson, Tanya; Gamst, Anthony C.; Collins, Julie M.; Chavez, Alyssa D.; Barakat, Fatma; Hassanein, Tarek; Sirlin, Claude B.
2016-01-01
Purpose To demonstrate a proof of concept that quantitative texture feature analysis of double contrast-enhanced magnetic resonance imaging (MRI) can classify fibrosis noninvasively, using histology as a reference standard. Materials and Methods A Health Insurance Portability and Accountability Act (HIPAA)-compliant Institutional Review Board (IRB)-approved retrospective study of 68 patients with diffuse liver disease was performed at a tertiary liver center. All patients underwent double contrast-enhanced MRI, with histopathology-based staging of fibrosis obtained within 12 months of imaging. The MaZda software program was used to compute 279 texture parameters for each image. A statistical regularization technique, generalized linear model (GLM)-path, was used to develop a model based on texture features for dichotomous classification of fibrosis category (F ≤2 vs. F ≥3) of the 68 patients, with histology as the reference standard. The model's performance was assessed and cross-validated. There was no additional validation performed on an independent cohort. Results Cross-validated sensitivity, specificity, and total accuracy of the texture feature model in classifying fibrosis were 91.9%, 83.9%, and 88.2%, respectively. Conclusion This study shows proof of concept that accurate, noninvasive classification of liver fibrosis is possible by applying quantitative texture analysis to double contrast-enhanced MRI. Further studies are needed in independent cohorts of subjects. PMID:22851409
Navabi, Nader; Hashemipour, Maryam A; Roughani, Aida
2017-02-01
Oral cancer is a global health problem; however, many dentists lack the necessary skills, knowledge and capacity to diagnose oral cancers early. This study aimed to examine the validity and reliability of a Persian short-form version of a standardised questionnaire to assess dentists' knowledge, practice and attitudes towards oral cancer. This cross-sectional analytical study was carried out in May 2015 in Tehran, Iran. An original 39-item English-language questionnaire developed by Yellowitz et al . was translated into Persian using forward and backward translation methods. A total of 15 dental professionals were asked to assess the questionnaire for content validity. Based on their feedback, a 20-item short-form version was prepared, including six demographic, six knowledge, four attitude and four practice items. The translated short-form questionnaire was subsequently distributed to 973 general dental practitioners attending a dental conference in Tehran. Internal consistency and reliability were assessed with Cronbach's alpha coefficient and item-total correlation calculations. A total of 13 professionals and 313 general dentists participated in the study (response rates: 86.7% and 32.2%, respectively). After the elimination of six items (two knowledge, two attitude and two practice items), the validity and reliability of the questionnaire was confirmed. The final Persian 14-item version of the questionnaire had acceptable validity and internal consistency. These results indicate that researchers can use this translated short-form version to evaluate oral cancer knowledge, attitudes and practices among Persian-speaking dentists; this will allow for a comparison of data between different populations.
Prediction of adult height in girls: the Beunen-Malina-Freitas method.
Beunen, Gaston P; Malina, Robert M; Freitas, Duarte L; Thomis, Martine A; Maia, José A; Claessens, Albrecht L; Gouveia, Elvio R; Maes, Hermine H; Lefevre, Johan
2011-12-01
The purpose of this study was to validate and cross-validate the Beunen-Malina-Freitas method for non-invasive prediction of adult height in girls. A sample of 420 girls aged 10-15 years from the Madeira Growth Study were measured at yearly intervals and then 8 years later. Anthropometric dimensions (lengths, breadths, circumferences, and skinfolds) were measured; skeletal age was assessed using the Tanner-Whitehouse 3 method and menarcheal status (present or absent) was recorded. Adult height was measured and predicted using stepwise, forward, and maximum R (2) regression techniques. Multiple correlations, mean differences, standard errors of prediction, and error boundaries were calculated. A sample of the Leuven Longitudinal Twin Study was used to cross-validate the regressions. Age-specific coefficients of determination (R (2)) between predicted and measured adult height varied between 0.57 and 0.96, while standard errors of prediction varied between 1.1 and 3.9 cm. The cross-validation confirmed the validity of the Beunen-Malina-Freitas method in girls aged 12-15 years, but at lower ages the cross-validation was less consistent. We conclude that the Beunen-Malina-Freitas method is valid for the prediction of adult height in girls aged 12-15 years. It is applicable to European populations or populations of European ancestry.
Voracek, Martin; Loibl, Lisa Mariella; Swami, Viren; Vintilă, Mona; Kõlves, Kairi; Sinniah, Dhachayani; Pillai, Subash Kumar; Ponnusamy, Subramaniam; Sonneck, Gernot; Furnham, Adrian; Lester, David
2008-12-01
The genetics of suicide is increasingly recognized and relevant for mental health literacy, but actual beliefs may lag behind current knowledge. We examined such beliefs in student samples (total N = 686) from Estonia, Malaysia, Romania, the United Kingdom, and the United States with the Beliefs in the Inheritance of Risk Factors for Suicide Scale. Cultural effects were small, those of key demographics nil. Several facets of construct validity were demonstrated. Marked differences in perceived plausibility of evidence about the genetics of suicide according to research design, observed in all samples, may be of general interest for investigating lay theories of abnormal behavior and communicating behavioral and psychiatric genetic research findings.
Bovis, Francesca; Consolaro, Alessandro; Pistorio, Angela; Garrone, Marco; Scala, Silvia; Patrone, Elisa; Rinaldi, Mariangela; Villa, Luca; Martini, Alberto; Ravelli, Angelo; Ruperto, Nicolino
2018-04-01
The aim of this project was to cross-culturally adapt and validate the Juvenile Arthritis Multidimensional Assessment Report (JAMAR) questionnaire in 54 languages across 52 different countries that are members of the Paediatric Rheumatology International Trials Organisation (PRINTO). This effort was part of a wider project named Epidemiology and Outcome of Children with Arthritis (EPOCA) to obtain information on the frequency of juvenile idiopathic arthritis (JIA) categories in different geographic areas, the therapeutic approaches adopted, and the disease status of children with JIA currently followed worldwide. A total of 13,843 subjects were enrolled from the 49 countries that took part both in the cross-cultural adaptation phase and in the related validation and data collection: Algeria, Argentina, Belgium, Brazil, Bulgaria, Canada, Chile, Colombia, Croatia, Czech Republic, Denmark, Ecuador, Egypt, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, India, Islamic Republic of Iran, Israel, Italy, Latvia, Libya, Lithuania, Mexico, Netherlands, Norway, Oman, Paraguay, Poland, Portugal, Romania, Russian Federation, Saudi Arabia, Serbia, Slovakia, Slovenia, South Africa, Spain, Sweden, Switzerland, Thailand, Turkey, Ukraine, United Kingdom and United States of America. 9021 patients had JIA (10.7% systemic arthritis, 41.9% oligoarthritis, 23.5% RF negative polyarthritis, 4.2% RF positive polyarthritis, 3.4% psoriatic arthritis, 10.6% enthesitis-related arthritis and 5.7% undifferentiated arthritis) while 4822 were healthy children. This introductory paper describes the overall methodology; results pertaining to each country are fully described in the accompanying manuscripts. In conclusion, the JAMAR translations were found to have satisfactory psychometric properties and it is thus a reliable and valid tool for the multidimensional assessment of children with JIA.
Gaspardo, B; Del Zotto, S; Torelli, E; Cividino, S R; Firrao, G; Della Riccia, G; Stefanon, B
2012-12-01
Fourier transform near infrared (FT-NIR) spectroscopy is an analytical procedure generally used to detect organic compounds in food. In this work the ability to predict fumonisin B(1)+B(2) contents in corn meal using an FT-NIR spectrophotometer, equipped with an integration sphere, was assessed. A total of 143 corn meal samples were collected in Friuli Venezia Giulia Region (Italy) and used to define a 15 principal components regression model, applying partial least square regression algorithm with full cross validation as internal validation. External validation was performed to 25 unknown samples. Coefficients of correlation, root mean square error and standard error of calibration were 0.964, 0.630 and 0.632, respectively and the external validation confirmed a fair potential of the model in predicting FB(1)+FB(2) concentration. Results suggest that FT-NIR analysis is a suitable method to detect FB(1)+FB(2) in corn meal and to discriminate safe meals from those contaminated. Copyright © 2012 Elsevier Ltd. All rights reserved.
Lee, Shin-Young; Lee, Eunice E
2015-02-01
The purpose of this study was to report the instrument modification and validation processes to make existing health belief model scales culturally appropriate for Korean Americans (KAs) regarding colorectal cancer (CRC) screening utilization. Instrument translation, individual interviews using cognitive interviewing, and expert reviews were conducted during the instrument modification phase, and a pilot test and a cross-sectional survey were conducted during the instrument validation phase. Data analyses of the cross-sectional survey included internal consistency and construct validity using exploratory and confirmatory factor analysis. The main issues identified during the instrument modification phase were (a) cultural and linguistic translation issues and (b) newly developed items reflecting Korean cultural barriers. Cross-sectional survey analyses during the instrument validation phase revealed that all scales demonstrate good internal consistency reliability (Cronbach's alpha=.72~.88). Exploratory factor analysis showed that susceptibility and severity loaded on the same factor, which may indicate a threat variable. Items with low factor loadings in the confirmatory factor analysis may relate to (a) lack of knowledge about fecal occult blood testing and (b) multiple dimensions of the subscales. Methodological, sequential processes of instrument modification and validation, including translation, individual interviews, expert reviews, pilot testing and a cross-sectional survey, were provided in this study. The findings indicate that existing instruments need to be examined for CRC screening research involving KAs.
Fernández-López, Juan Antonio; Fernández-Fidalgo, María; Martín-Payo, Rubén; Rödel, Andreas
2007-08-01
To evaluate the relationship between Health-Related Quality of Life (HRQL) and stress at work among Primary Care workers, as evidence of the construct validity of the Spanish version (PECVEC) of the profile of quality of life in the chronically ill (PLC) questionnaire. In addition, to check its other psychometric properties. Cross-sectional study. Eighteen primary care centres in Health Area IV, Asturias (Oviedo), Spain, sharing similar socio-demographic conditions. Two hundred and thirty-three primary care nurses and physicians. HRQL was evaluated by the 6 general dimensions of the Spanish version of the PLC. Stress at work was evaluated by the three scales of the Effort-Reward Imbalance (ERI) questionnaire. The construct validity of the PECVEC was assessed by testing the inverse associations of QoL dimensions and job stress ones, when the most important confuser variables were monitored. The non-response rate was low (<3%), and no floor effects and only small ceiling effects were observed. Internal consistency analysis and exploratory and confirmatory factor analysis demonstrated high reliability, factorial validity and convergent/divergent validity of the PECVEC. The PECVEC demonstrates adequate psychometric properties for evaluating HRQL in healthy subjects.
Validation of the Hebrew version of the Burn Specific Health Scale-Brief questionnaire.
Stavrou, Demetris; Haik, Josef; Wiser, Itay; Winkler, Eyal; Liran, Alon; Holloway, Samantha; Boyd, Julie; Zilinsky, Isaac; Weissman, Oren
2015-02-01
The Burns Specific Health Scale-Brief (BSHS-B) questionnaire is a suitable measurement tool for the assessment of general, physical, mental, and social health aspects of the burn survivor. To translate, culturally adapt and validate the BSHS-B to Hebrew (BSHS-H), and to investigate its psychometric properties. Eighty-six Hebrew speaking burn survivors filled out the BSHS-B and SF-36 questionnaires. Ten of them (11.63%) completed a retest. The psychometric properties of the scale were evaluated. Internal consistency, criterion validity, and construct validity were assessed using interclass correlation coefficient, Cronbach's alpha statistic, Spearman rank test, and Mann-Whitney U test respectively. BSHS-H Cronbach's alpha coefficient was 0.97. Test-retest interclass coefficients were between 0.81 and 0.98. BSHS-H was able to discriminate between facial burns, hand burns and burns >10% body surface area (p<0.05). BSHS-H and SF-36 were positively correlated (r(2)=0.667, p<0.01). BSHS-H is a reliable and valid instrument for use in the Israeli burn survivor population. The translation and cross-cultural adaptation of this disease specific scale allows future comparative international studies. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.
Cross-Cultural Validation of the Five-Factor Structure of Social Goals: A Filipino Investigation
ERIC Educational Resources Information Center
King, Ronnel B.; Watkins, David A.
2012-01-01
The aim of the present study was to test the cross-cultural validity of the five-factor structure of social goals that Dowson and McInerney proposed. Using both between-network and within-network approaches to construct validation, 1,147 Filipino high school students participated in the study. Confirmatory factor analysis indicated that the…
Integration and validation testing for PhEDEx, DBS and DAS with the PhEDEx LifeCycle agent
NASA Astrophysics Data System (ADS)
Boeser, C.; Chwalek, T.; Giffels, M.; Kuznetsov, V.; Wildish, T.
2014-06-01
The ever-increasing amount of data handled by the CMS dataflow and workflow management tools poses new challenges for cross-validation among different systems within CMS experiment at LHC. To approach this problem we developed an integration test suite based on the LifeCycle agent, a tool originally conceived for stress-testing new releases of PhEDEx, the CMS data-placement tool. The LifeCycle agent provides a framework for customising the test workflow in arbitrary ways, and can scale to levels of activity well beyond those seen in normal running. This means we can run realistic performance tests at scales not likely to be seen by the experiment for some years, or with custom topologies to examine particular situations that may cause concern some time in the future. The LifeCycle agent has recently been enhanced to become a general purpose integration and validation testing tool for major CMS services. It allows cross-system integration tests of all three components to be performed in controlled environments, without interfering with production services. In this paper we discuss the design and implementation of the LifeCycle agent. We describe how it is used for small-scale debugging and validation tests, and how we extend that to large-scale tests of whole groups of sub-systems. We show how the LifeCycle agent can emulate the action of operators, physicists, or software agents external to the system under test, and how it can be scaled to large and complex systems.
Davies, John R; Chang, Yu-mei; Bishop, D Timothy; Armstrong, Bruce K; Bataille, Veronique; Bergman, Wilma; Berwick, Marianne; Bracci, Paige M; Elwood, J Mark; Ernstoff, Marc S; Green, Adele; Gruis, Nelleke A; Holly, Elizabeth A; Ingvar, Christian; Kanetsky, Peter A; Karagas, Margaret R; Lee, Tim K; Le Marchand, Loïc; Mackie, Rona M; Olsson, Håkan; Østerlind, Anne; Rebbeck, Timothy R; Reich, Kristian; Sasieni, Peter; Siskind, Victor; Swerdlow, Anthony J; Titus, Linda; Zens, Michael S; Ziegler, Andreas; Gallagher, Richard P.; Barrett, Jennifer H; Newton-Bishop, Julia
2015-01-01
Background We report the development of a cutaneous melanoma risk algorithm based upon 7 factors; hair colour, skin type, family history, freckling, nevus count, number of large nevi and history of sunburn, intended to form the basis of a self-assessment webtool for the general public. Methods Predicted odds of melanoma were estimated by analysing a pooled dataset from 16 case-control studies using logistic random coefficients models. Risk categories were defined based on the distribution of the predicted odds in the controls from these studies. Imputation was used to estimate missing data in the pooled datasets. The 30th, 60th and 90th centiles were used to distribute individuals into four risk groups for their age, sex and geographic location. Cross-validation was used to test the robustness of the thresholds for each group by leaving out each study one by one. Performance of the model was assessed in an independent UK case-control study dataset. Results Cross-validation confirmed the robustness of the threshold estimates. Cases and controls were well discriminated in the independent dataset (area under the curve 0.75, 95% CI 0.73-0.78). 29% of cases were in the highest risk group compared with 7% of controls, and 43% of controls were in the lowest risk group compared with 13% of cases. Conclusion We have identified a composite score representing an estimate of relative risk and successfully validated this score in an independent dataset. Impact This score may be a useful tool to inform members of the public about their melanoma risk. PMID:25713022
Longo Imedio, Isabel; Serra-Guillén, Carlos
2016-01-01
While there are questionnaires for evaluating the effects of skin cancer on patient quality of life, there are no specific questionnaires available in Spanish for evaluating quality of life in patients with actinic keratosis. The aim of this study was to translate and culturally adapt the Actinic Keratosis Quality of Life (AKQoL) questionnaire into Spanish. The original questionnaire was translated into Spanish following the guidelines for the cross-cultural adaptation of self-report measures. Several measures of general reliability and validity were calculated, including Cronbach α for internal consistency and the Spearman rank-order correlation coefficient and a Bland-Altman plot for test-retest reliability. To test concurrent validity, we used the Pearson correlation coefficient to measure the correlation between AKQoL and Skindex-29 scores. The final version of the questionnaire was administered to 621 patients with actinic keratosis, who scored a mean (SD) of 5.25 (4.73) points (total possible score, 0-25). The Cronbach α reliability coefficient analysis was 0.84. The correlation between the mean (SD) score on the Skindex-29 (1.87 [4.07]) and on the AKQoL (1.97 [2.98] was 0.344 (P=.002, Spearman's rho), with a proportion of shared variance of 11.8%. The translation, cross-cultural adaptation, and validation of the original AKQoL produced a reliable, easily understandable questionnaire for evaluating the impact of actinic keratosis on the quality of life of patients in our setting. Copyright © 2016 AEDV. Published by Elsevier España, S.L.U. All rights reserved.
Structure formation beyond shell-crossing: nonperturbative expansions and late-time attractors
NASA Astrophysics Data System (ADS)
Pietroni, Massimo
2018-06-01
Structure formation in 1+1 dimensions is considered, with emphasis on the effects of shell-crossing. The breakdown of the perturbative expansion beyond shell-crossing is discussed, and it is shown, in a simple example, that the perturbative series can be extended to a transseries including nonperturbative terms. The latter converges to the exact result well beyond the range of validity of perturbation theory. The crucial role of the divergences induced by shell-crossing is discussed. They provide constraints on the structure of the transseries and act as a bridge between the perturbative and the nonperturbative sectors. Then, we show that the dynamics in the deep multistreaming regime is governed by attractors. In the case of simple initial conditions, these attractors coincide with the asymptotic configurations of the adhesion model, but in general they may differ. These results are applied to a cosmological setting, and an algorithm to build the attractor solution starting from the Zel'dovich approximation is developed. Finally, this algorithm is applied to the search of `haloes' and the results are compared with those obtained from the exact dynamical equations.
Kudesia, Rashmi; Chernyak, Elizabeth; McAvey, Beth
2017-10-01
To create, validate, and use a fertility awareness survey based on current U.S. Cross-sectional study. Not applicable. Phase 1 included U.S. women ages 18-45; phase 2 included female medical students and obstetrics and gynecology trainees at two urban academic programs. Survey including demographics, the Fertility & Infertility Treatment Knowledge Score (FIT-KS) instrument, and General Nutrition Knowledge Questionnaire. Knowledge of natural fertility and infertility treatments. The FIT-KS was validated through detailed item and validity analyses. In phase 1, 127 women participated; their median age was 31 years, and 43.7% had children. Their mean FIT-KS score was 16.2 ± 3.5 (55.9% correct). In phase 2, 118 medical trainees participated; their median age was 25 years, and 12.4% had children. Their mean FIT-KS score was 18.8 ± 2.1 (64.9% correct), with year of training correlating to a higher score (r=0.40). Participant awareness regarding lifestyle factors varied, but it was particularly low regarding the effects of lubricants. The majority underestimated the spontaneous miscarriage rate and overestimated the fecundability of 40-year-old women. There was general overestimation of success rates for assisted reproductive technologies, particularly among medical trainees. The FIT-KS is validated to current U.S. data for use in both general and medical populations as a quick assessment of fertility knowledge. The knowledge gaps demonstrated in this study correlate with national trends in delayed childbearing and time to initiate treatment. For medical trainees, these results raise concerns about the quality of fertility counseling they may be able to offer patients. Greater educational outreach must be undertaken to enhance fertility awareness. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
Assessing cross-cultural validity of scales: a methodological review and illustrative example.
Beckstead, Jason W; Yang, Chiu-Yueh; Lengacher, Cecile A
2008-01-01
In this article, we assessed the cross-cultural validity of the Women's Role Strain Inventory (WRSI), a multi-item instrument that assesses the degree of strain experienced by women who juggle the roles of working professional, student, wife and mother. Cross-cultural validity is evinced by demonstrating the measurement invariance of the WRSI. Measurement invariance is the extent to which items of multi-item scales function in the same way across different samples of respondents. We assessed measurement invariance by comparing a sample of working women in Taiwan with a similar sample from the United States. Structural equation models (SEMs) were employed to determine the invariance of the WRSI and to estimate the unique validity variance of its items. This article also provides nurse-researchers with the necessary underlying measurement theory and illustrates how SEMs may be applied to assess cross-cultural validity of instruments used in nursing research. Overall performance of the WRSI was acceptable but our analysis showed that some items did not display invariance properties across samples. Item analysis is presented and recommendations for improving the instrument are discussed.
Sattler, Tine; Sekulic, Damir; Spasic, Miodrag; Osmankac, Nedzad; Vicente João, Paulo; Dervisevic, Edvin; Hadzic, Vedran
2016-01-01
Previous investigations noted potential importance of isokinetic strength in rapid muscular performances, such as jumping. This study aimed to identify the influence of isokinetic-knee-strength on specific jumping performance in volleyball. The secondary aim of the study was to evaluate reliability and validity of the two volleyball-specific jumping tests. The sample comprised 67 female (21.96±3.79 years; 68.26±8.52 kg; 174.43±6.85 cm) and 99 male (23.62±5.27 years; 84.83±10.37 kg; 189.01±7.21 cm) high- volleyball players who competed in 1st and 2nd National Division. Subjects were randomly divided into validation (N.=55 and 33 for males and females, respectively) and cross-validation subsamples (N.=54 and 34 for males and females, respectively). Set of predictors included isokinetic tests, to evaluate the eccentric and concentric strength capacities of the knee extensors, and flexors for dominant and non-dominant leg. The main outcome measure for the isokinetic testing was peak torque (PT) which was later normalized for body mass and expressed as PT/Kg. Block-jump and spike-jump performances were measured over three trials, and observed as criteria. Forward stepwise multiple regressions were calculated for validation subsamples and then cross-validated. Cross validation included correlations between and t-test differences between observed and predicted scores; and Bland Altman graphics. Jumping tests were found to be reliable (spike jump: ICC of 0.79 and 0.86; block-jump: ICC of 0.86 and 0.90; for males and females, respectively), and their validity was confirmed by significant t-test differences between 1st vs. 2nd division players. Isokinetic variables were found to be significant predictors of jumping performance in females, but not among males. In females, the isokinetic-knee measures were shown to be stronger and more valid predictors of the block-jump (42% and 64% of the explained variance for validation and cross-validation subsample, respectively) than that of the spike-jump (39% and 34% of the explained variance for validation and cross-validation subsample, respectively). Differences between prediction models calculated for males and females are mostly explained by gender-specific biomechanics of jumping. Study defined importance of knee-isokinetic-strength in volleyball jumping performance in female athletes. Further studies should evaluate association between ankle-isokinetic-strength and volleyball-specific jumping performances. Results reinforce the need for the cross-validation of the prediction-models in sport and exercise sciences.
Mbada, Chidozie Emmanuel; Adeogun, Gafar Atanda; Ogunlana, Michael Opeoluwa; Adedoyin, Rufus Adesoji; Akinsulore, Adesanmi; Awotidebe, Taofeek Oluwole; Idowu, Opeyemi Ayodiipo; Olaoye, Olumide Ayoola
2015-09-14
The Short-Form Health Survey (SF-36) is a valid quality of life tool often employed to determine the impact of medical intervention and the outcome of health care services. However, the SF-36 is culturally sensitive which necessitates its adaptation and translation into different languages. This study was conducted to cross-culturally adapt the SF-36 into Yoruba language and determine its reliability and validity. Based on the International Quality of Life Assessment project guidelines, a sequence of translation, test of item-scale correlation, and validation was implemented for the translation of the Yoruba version of the SF-36. Following pilot testing, the English and the Yoruba versions of the SF-36 were administered to a random sample of 1087 apparently healthy individuals to test validity and 249 respondents completed the Yoruba SF-36 again after two weeks to test reliability. Data was analyzed using Pearson's product moment correlation analysis, independent t-test, one-way analysis of variance, multi trait scaling analysis and Intra-Class Correlation (ICC) at p < 0.05. The concurrent validity scores for scales and domains ranges between 0.749 and 0.902 with the highest and lowest scores in the General Health (0.902) and Bodily Pain (0.749) scale. Scale-level descriptive result showed that all scale and domain scores had negative skewness ranging from -2.08 to -0.98. The mean scores for each scales ranges between 83.2 and 88.8. The domain scores for Physical Health Component and Mental Health Component were 85.6 ± 13.7 and 85.9 ± 15.4 respectively. The convergent validity was satisfactory, ranging from 0.421 to 0.907. Discriminant validity was also satisfactory except for item '1'. The ICC for the test-retest reliability of the Yoruba SF-36 ranges between 0.636 and 0.843 for scales; and 0.783 and 0.851 for domains. The data quality, concurrent and discriminant validity, reliability and internal consistency of the Yoruba version of the SF-36 are adequate and it is recommended for measuring health-related quality of life among Yoruba population.
Planar spatial correlations, anisotropy, and specific surface area of stationary random porous media
NASA Astrophysics Data System (ADS)
Berryman, James G.
1998-02-01
An earlier result of the author showed that an anisotropic spatial correlation function of a random porous medium could be used to compute the specific surface area when it is stationary as well as anisotropic by first performing a three-dimensional radial average and then taking the first derivative with respect to lag at the origin. This result generalized the earlier result for isotropic porous media of Debye et al. [J. Appl. Phys. 28, 679 (1957)]. The present article provides more detailed information about the use of spatial correlation functions for anisotropic porous media and in particular shows that, for stationary anisotropic media, the specific surface area can be related to the derivative of the two-dimensional radial average of the correlation function measured from cross sections taken through the anisotropic medium. The main concept is first illustrated using a simple pedagogical example for an anisotropic distribution of spherical voids. Then, a general derivation of formulas relating the derivative of the planar correlation functions to surface integrals is presented. When the surface normal is uniformly distributed (as is the case for any distribution of spherical voids), our formulas can be used to relate a specific surface area to easily measurable quantities from any single cross section. When the surface normal is not distributed uniformly (as would be the case for an oriented distribution of ellipsoidal voids), our results show how to obtain valid estimates of specific surface area by averaging measurements on three orthogonal cross sections. One important general observation for porous media is that the surface area from nearly flat cracks may be underestimated from measurements on orthogonal cross sections if any of the cross sections happen to lie in the plane of the cracks. This result is illustrated by taking the very small aspect ratio (penny-shaped crack) limit of an oblate spheroid, but holds for other types of flat surfaces as well.
Planar spatial correlations, anisotropy, and specific surface area of stationary random porous media
DOE Office of Scientific and Technical Information (OSTI.GOV)
Berryman, J.G.
1998-02-01
An earlier result of the author showed that an anisotropic spatial correlation function of a random porous medium could be used to compute the specific surface area when it is stationary as well as anisotropic by first performing a three-dimensional radial average and then taking the first derivative with respect to lag at the origin. This result generalized the earlier result for isotropic porous media of Debye {ital et al.} [J. Appl. Phys. {bold 28}, 679 (1957)]. The present article provides more detailed information about the use of spatial correlation functions for anisotropic porous media and in particular shows that,more » for stationary anisotropic media, the specific surface area can be related to the derivative of the two-dimensional radial average of the correlation function measured from cross sections taken through the anisotropic medium. The main concept is first illustrated using a simple pedagogical example for an anisotropic distribution of spherical voids. Then, a general derivation of formulas relating the derivative of the planar correlation functions to surface integrals is presented. When the surface normal is uniformly distributed (as is the case for any distribution of spherical voids), our formulas can be used to relate a specific surface area to easily measurable quantities from any single cross section. When the surface normal is not distributed uniformly (as would be the case for an oriented distribution of ellipsoidal voids), our results show how to obtain valid estimates of specific surface area by averaging measurements on three orthogonal cross sections. One important general observation for porous media is that the surface area from nearly flat cracks may be underestimated from measurements on orthogonal cross sections if any of the cross sections happen to lie in the plane of the cracks. This result is illustrated by taking the very small aspect ratio (penny-shaped crack) limit of an oblate spheroid, but holds for other types of flat surfaces as well.« less
Neutrino-electron scattering: general constraints on Z ' and dark photon models
NASA Astrophysics Data System (ADS)
Lindner, Manfred; Queiroz, Farinaldo S.; Rodejohann, Werner; Xu, Xun-Jie
2018-05-01
We study the framework of U(1) X models with kinetic mixing and/or mass mixing terms. We give general and exact analytic formulas of fermion gauge interactions and the cross sections of neutrino-electron scattering in such models. Then we derive limits on a variety of U(1) X models that induce new physics contributions to neutrino-electron scattering, taking into account interference between the new physics and Standard Model contributions. Data from TEXONO, CHARM-II and GEMMA are analyzed and shown to be complementary to each other to provide the most restrictive bounds on masses of the new vector bosons. In particular, we demonstrate the validity of our results to dark photon-like as well as light Z ' models.
Bittante, G; Ferragina, A; Cipolat-Gotet, C; Cecchinato, A
2014-10-01
Cheese yield is an important technological trait in the dairy industry. The aim of this study was to infer the genetic parameters of some cheese yield-related traits predicted using Fourier-transform infrared (FTIR) spectral analysis and compare the results with those obtained using an individual model cheese-producing procedure. A total of 1,264 model cheeses were produced using 1,500-mL milk samples collected from individual Brown Swiss cows, and individual measurements were taken for 10 traits: 3 cheese yield traits (fresh curd, curd total solids, and curd water as a percent of the weight of the processed milk), 4 milk nutrient recovery traits (fat, protein, total solids, and energy of the curd as a percent of the same nutrient in the processed milk), and 3 daily cheese production traits per cow (fresh curd, total solids, and water weight of the curd). Each unprocessed milk sample was analyzed using a MilkoScan FT6000 (Foss, Hillerød, Denmark) over the spectral range, from 5,000 to 900 wavenumber × cm(-1). The FTIR spectrum-based prediction models for the previously mentioned traits were developed using modified partial least-square regression. Cross-validation of the whole data set yielded coefficients of determination between the predicted and measured values in cross-validation of 0.65 to 0.95 for all traits, except for the recovery of fat (0.41). A 3-fold external validation was also used, in which the available data were partitioned into 2 subsets: a training set (one-third of the herds) and a testing set (two-thirds). The training set was used to develop calibration equations, whereas the testing subsets were used for external validation of the calibration equations and to estimate the heritabilities and genetic correlations of the measured and FTIR-predicted phenotypes. The coefficients of determination between the predicted and measured values in cross-validation results obtained from the training sets were very similar to those obtained from the whole data set, but the coefficient of determination of validation values for the external validation sets were much lower for all traits (0.30 to 0.73), and particularly for fat recovery (0.05 to 0.18), for the training sets compared with the full data set. For each testing subset, the (co)variance components for the measured and FTIR-predicted phenotypes were estimated using bivariate Bayesian analyses and linear models. The intraherd heritabilities for the predicted traits obtained from our internal cross-validation using the whole data set ranged from 0.085 for daily yield of curd solids to 0.576 for protein recovery, and were similar to those obtained from the measured traits (0.079 to 0.586, respectively). The heritabilities estimated from the testing data set used for external validation were more variable but similar (on average) to the corresponding values obtained from the whole data set. Moreover, the genetic correlations between the predicted and measured traits were high in general (0.791 to 0.996), and they were always higher than the corresponding phenotypic correlations (0.383 to 0.995), especially for the external validation subset. In conclusion, we herein report that application of the cross-validation technique to the whole data set tended to overestimate the predictive ability of FTIR spectra, give more precise phenotypic predictions than the calibrations obtained using smaller data sets, and yield genetic correlations similar to those obtained from the measured traits. Collectively, our findings indicate that FTIR predictions have the potential to be used as indicator traits for the rapid and inexpensive selection of dairy populations for improvement of cheese yield, milk nutrient recovery in curd, and daily cheese production per cow. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Machado, Luciana A. C.; Telles, Rosa W.; Costa-Silva, Luciana; Barreto, Sandhi M.
2016-01-01
Abstract Background Health-related control and self-efficacy beliefs can be assessed in the general population using Multidimensional Health Locus of Control-A subscales (MHLC-A) and the General Self-Efficacy Scale (GSES), respectively. Objective To test construct validity, internal consistency, reliability (test-retest) and ceiling and floor effects of Portuguese-Brazil versions of MHLC-A and GSES. Method Civil servants (N=2901) enrolled in a large Brazilian cohort were included. A new version of the GSES was produced (GSES-Brazil). Procedures for cross-cultural adaptation and testing of psychometric properties followed well-accepted international guidelines. Results Confirmatory factor analyses yielded the following indices: MHLC-A (tridimensional model): χ2[df]=223.45[132], p-value <0.01; CFI=0.87; TLI=0.85; RMSEA=0.07 (0.07-0.08); WRMR=3.00. GSES-Brazil (unidimensional model): χ2[df]=788.60[35], p-value <0.01; CFI=0.95; TLI=0.94; RMSEA=0.09 (0.08-0.09); WRMR=2.50. Cronbach’s alpha coefficients and Intraclass Correlation Coefficients (ICC2,1) ranged from 0.57 (0.54-0.59) and 0.57 (0.47-0.65) for MHLC-A internality to 0.80 (0.79-0.81) and 0.71 (0.66-0.77) for GSES-Brazil, respectively. There was no evidence of ceiling and floor effects. Convergent validity analyses provided further support for construct validity of both scales. Conclusion These findings support the use of the newly developed version of GSES-Brazil for the assessment of general self-efficacy of adult Brazilians. Internal consistency was lower than ideal for MHLC-A, indicating these subscales may need further refinements to provide a more psychometrically sound measure of control beliefs. PMID:27878226
ERIC Educational Resources Information Center
Fromm, Germán; Hallinger, Philip; Volante, Paulo; Wang, Wen Chung
2017-01-01
The purposes of this study were to report on a systematic approach to validating a Spanish version of the Principal Instructional Management Rating Scale and then to apply the scale in a cross-national comparison of principal instructional leadership. The study yielded a validated Spanish language version of the PIMRS Teacher Form and offers a…
Assessment of Some Atomization Models Used in Spray Calculations
NASA Technical Reports Server (NTRS)
Raju, M. S.; Bulzin, Dan
2011-01-01
The paper presents the results from a validation study undertaken as a part of the NASA s fundamental aeronautics initiative on high altitude emissions in order to assess the accuracy of several atomization models used in both non-superheat and superheat spray calculations. As a part of this investigation we have undertaken the validation based on four different cases to investigate the spray characteristics of (1) a flashing jet generated by the sudden release of pressurized R134A from cylindrical nozzle, (2) a liquid jet atomizing in a subsonic cross flow, (3) a Parker-Hannifin pressure swirl atomizer, and (4) a single-element Lean Direct Injector (LDI) combustor experiment. These cases were chosen because of their importance in some aerospace applications. The validation is based on some 3D and axisymmetric calculations involving both reacting and non-reacting sprays. In general, the predicted results provide reasonable agreement for both mean droplet sizes (D32) and average droplet velocities but mostly underestimate the droplets sizes in the inner radial region of a cylindrical jet.
Factor complexity of crash occurrence: An empirical demonstration using boosted regression trees.
Chung, Yi-Shih
2013-12-01
Factor complexity is a characteristic of traffic crashes. This paper proposes a novel method, namely boosted regression trees (BRT), to investigate the complex and nonlinear relationships in high-variance traffic crash data. The Taiwanese 2004-2005 single-vehicle motorcycle crash data are used to demonstrate the utility of BRT. Traditional logistic regression and classification and regression tree (CART) models are also used to compare their estimation results and external validities. Both the in-sample cross-validation and out-of-sample validation results show that an increase in tree complexity provides improved, although declining, classification performance, indicating a limited factor complexity of single-vehicle motorcycle crashes. The effects of crucial variables including geographical, time, and sociodemographic factors explain some fatal crashes. Relatively unique fatal crashes are better approximated by interactive terms, especially combinations of behavioral factors. BRT models generally provide improved transferability than conventional logistic regression and CART models. This study also discusses the implications of the results for devising safety policies. Copyright © 2012 Elsevier Ltd. All rights reserved.
Cross-cultural adaptation and validation to Brazil of the Obesity-related Problems Scale.
Brasil, Andreia Mara Brolezzi; Brasil, Fábio; Maurício, Angélica Aparecida; Vilela, Regina Maria
2017-01-01
To validate a reliable version of the Obesity-related Problems Scale in Portuguese to use it in Brazil. The Obesity-related Problems Scale was translated and transculturally adapted. Later it was simultaneously self-applied with a 12-item version of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), to 50 obese patients and 50 non-obese individuals, and applied again to half of them after 14 days. The Obesity-related Problems scale was able to differentiate obese from non-obese individuals with higher accuracy than WHODAS 2.0, correlating with this scale and with body mass index. The factor analysis determined a two-dimensional structure, which was confirmed with χ2/df=1.81, SRMR=0.05, and CFI=0.97. The general a coefficient was 0.90 and the inter-item intra-class correlation, in the reapplication, ranged from 0.75 to 0.87. The scale proved to be valid and reliable for use in the Brazilian population, without the need to exclude items.
[The modern sources for making a medical geography description].
2014-02-01
The current article is dedicated to application of Internet for acquisition of medical geography information. The vast majority of the modern domestic reference manuals are neither reliable nor up-to-date. At the time when the foreign printed sources are not easily accessible the foreign web resources often become the main source of information. The article possesses some practical advice on how to find the general, medical and military medical data on the web. It is emphasized the necessity of careful cross validation of all the obtained data to be confident in their reliability.
The evolution of Crew Resource Management training in commercial aviation
NASA Technical Reports Server (NTRS)
Helmreich, R. L.; Merritt, A. C.; Wilhelm, J. A.
1999-01-01
In this study, we describe changes in the nature of Crew Resource Management (CRM) training in commercial aviation, including its shift from cockpit to crew resource management. Validation of the impact of CRM is discussed. Limitations of CRM, including lack of cross-cultural generality are considered. An overarching framework that stresses error management to increase acceptance of CRM concepts is presented. The error management approach defines behavioral strategies taught in CRM as error countermeasures that are employed to avoid error, to trap errors committed, and to mitigate the consequences of error.
Nascimento, Maria Isabel do; Reichenheim, Michael Eduardo; Monteiro, Gina Torres Rego
2011-12-01
The objective of this study was to reassess the dimensional structure of a Brazilian version of the Scale of Satisfaction with Interpersonal Processes of General Medical Care, proposed originally as a one-dimensional instrument. Strict confirmatory factor analysis (CFA) and exploratory factor analysis modeled within a CFA framework (E/CFA) were used to identify the best model. An initial CFA rejected the one-dimensional structure, while an E/CFA suggested a two-dimensional structure. The latter structure was followed by a new CFA, which showed that the model without cross-loading was the most parsimonious, with adequate fit indices (CFI = 0.982 and TLI = 0.988), except for RMSEA (0.062). Although the model achieved convergent validity, discriminant validity was questionable, with the square-root of the mean variance extracted from dimension 1 estimates falling below the respective factor correlation. According to these results, there is not sufficient evidence to recommend the immediate use of the instrument, and further studies are needed for a more in-depth analysis of the postulated structures.
NASA Astrophysics Data System (ADS)
Raymond Ooi, C. H.; Sun, Qingqing; Zubairy, M. Suhail; Scully, Marlan O.
2007-01-01
We present a largely analytical theory for two-photon correlations G(2) between Stokes (s) and anti-Stokes (a) photon pairs from an extended medium (amplifier) composed of double- Λ atoms in counterpropagating geometry. We generalize the parametric coupled equations with quantum Langevin noise given in a beautiful experimental paper of Balic [Phys. Rev. Lett. 94, 183601 (2005)] beyond adiabatic approximation and valid for arbitrary strength and detuning of laser fields. We derive an analytical formula for cross correlation Gas(2)=⟨Ês†(L)Êa†(0,τ)Êa(0,τ)Ês(L)⟩ and use it to obtain results that are in good quantitative agreement with the experimental data. Results for Gas(2) obtained using our coupled equations are in good quantitative agreement with the results using the equations of Balic , while perfect agreement is obtained for sufficiently large detuning. We also compute the reverse correlation Gsa(2) which turns out to be negligibly small and remains classical while the cross correlation violates the Cauchy-Schwartz inequality by a factor of more than a hundred.
Lodge, Keri-Michèle; Milnes, David; Gilbody, Simon M
2011-03-01
Background Identifying patients with learning disabilities within primary care is central to initiatives for improving the health of this population. UK general practitioners (GPs) receive additional income for maintaining registers of patients with learning disabilities as part of the Quality and Outcomes Framework (QOF), and may opt to provide Directed Enhanced Services (DES), which requires practices to maintain registers of patients with moderate or severe learning disabilities and offer them annual health checks.Objectives This paper describes the development of a register of patients with moderate or severe learning disabilities at one UK general practice.Methods A Read code search of one UK general practice's electronic medical records was conducted in order to identify patients with learning disabilities. Confirmation of diagnoses was sought by scrutinising records and GP verification. Cross-referencing with the practice QOF register of patients with learning disabilities of any severity, and the local authority's list of clients with learning disabilities, was performed.Results Of 15 001 patients, 229 (1.5%) were identified by the Read code search as possibly having learning disabilities. Scrutiny of records and GP verification confirmed 64 had learning disabilities and 24 did not, but the presence or absence of learning disability remained unclear in 141 cases. Cross-referencing with the QOF register (n=81) and local authority list (n=49) revealed little overlap.Conclusion Identifying learning disability and assessing its severity are tasks GPs may be unfamiliar with, and relying on Read code searches may result in under-detection. Further research is needed to define optimum strategies for identifying, cross-referencing and validating practice-based registers of patients with learning disabilities.
2011-01-01
Background Identifying patients with learning disabilities within primary care is central to initiatives for improving the health of this population. UK general practitioners (GPs) receive additional income for maintaining registers of patients with learning disabilities as part of the Quality and Outcomes Framework (QOF), and may opt to provide Directed Enhanced Services (DES), which requires practices to maintain registers of patients with moderate or severe learning disabilities and offer them annual health checks. Objectives This paper describes the development of a register of patients with moderate or severe learning disabilities at one UK general practice. Methods A Read code search of one UK general practice's electronic medical records was conducted in order to identify patients with learning disabilities. Confirmation of diagnoses was sought by scrutinising records and GP verification. Cross-referencing with the practice QOF register of patients with learning disabilities of any severity, and the local authority's list of clients with learning disabilities, was performed. Results Of 15 001 patients, 229 (1.5%) were identified by the Read code search as possibly having learning disabilities. Scrutiny of records and GP verification confirmed 64 had learning disabilities and 24 did not, but the presence or absence of learning disability remained unclear in 141 cases. Cross-referencing with the QOF register (n=81) and local authority list (n=49) revealed little overlap. Conclusion Identifying learning disability and assessing its severity are tasks GPs may be unfamiliar with, and relying on Read code searches may result in under-detection. Further research is needed to define optimum strategies for identifying, cross-referencing and validating practice-based registers of patients with learning disabilities. PMID:22479290
NASA Technical Reports Server (NTRS)
Viswanathan, A. V.; Tamekuni, M.
1973-01-01
Analytical methods based on linear theory are presented for predicting the thermal stresses in and the buckling of heated structures with arbitrary uniform cross section. The structure is idealized as an assemblage of laminated plate-strip elements, curved and planar, and beam elements. Uniaxially stiffened plates and shells of arbitrary cross section are typical examples. For the buckling analysis the structure or selected elements may be subjected to mechanical loads, in additional to thermal loads, in any desired combination of inplane transverse load and axial compression load. The analysis is also applicable to stiffened structures under inplane loads varying through the cross section, as in stiffened shells under bending. The buckling analysis is general and covers all modes of instability. The analysis has been applied to a limited number of problems and the results are presented. These while showing the validity and the applicability of the method do not reflect its full capability.
Validity of Hansen-Roach cross sections in low-enriched uranium systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Busch, R.D.; O'Dell, R.D.
Within the nuclear criticality safety community, the Hansen-Roach 16 group cross section set has been the standard'' for use in k{sub eff} calculations over the past 30 years. Yet even with its widespread acceptance, there are still questions about its validity and adequacy, about the proper procedure for calculating the potential scattering cross section, {sigma}{sub p}, for uranium and plutonium, and about the concept of resonance self shielding and its impact on cross sections. This paper attempts to address these questions. It provides a brief background on the Hansen-Roach cross sections. Next is presented a review of resonances in crossmore » sections, self shielding of these resonances, and the use of {sigma}{sub p} to characterize resonance self shielding. Three prescriptions for calculating {sigma}{sub p} are given. Finally, results of several calculations of k{sub eff} on low-enriched uranium systems are provided to confirm the validity of the Hansen-Roach cross sections when applied to such systems.« less
Yeh, Mei-Yu; Lin, Sieh-Hwa; Tung, Tao-Hsin
2014-01-01
To evaluate the psychometric properties of the Chinese version of the Patient Perceptions of Empowerment Scale (PPES) and to perform a cross-cultural validity assessment. In this cross-sectional survey, 554 inpatients in three general hospitals in northern Taiwan were recruited. Principal component analysis was used to examine the factor structure of the scale. Confirmatory factor analyses were conducted on the measurement model of the Chinese version of the PPES. Confirmatory factor analyses supported the presence of a second-order four-factor model (information, decision, individual, and self-management) of the Chinese version of the PPES when used with a Taiwanese inpatient population. The results indicate that the 11-item, second-order, four-factor Chinese version of the PPES provided best goodness-of-fit for the data in this study. The 11-item four-factor Chinese version of the PPES is a self-completion scale. This study demonstrated that the Chinese version of the PPES is a reliable and valid self-report instrument for the assessment of patient perceptions of empowerment in clinical practice. Further adaptation and evaluation of the scale will hopefully stimulate further studies on PPES in the fields of psychometrics in Taiwan.
Lin, Sieh-Hwa
2014-01-01
Objectives. To evaluate the psychometric properties of the Chinese version of the Patient Perceptions of Empowerment Scale (PPES) and to perform a cross-cultural validity assessment. Methods. In this cross-sectional survey, 554 inpatients in three general hospitals in northern Taiwan were recruited. Principal component analysis was used to examine the factor structure of the scale. Confirmatory factor analyses were conducted on the measurement model of the Chinese version of the PPES. Results. Confirmatory factor analyses supported the presence of a second-order four-factor model (information, decision, individual, and self-management) of the Chinese version of the PPES when used with a Taiwanese inpatient population. The results indicate that the 11-item, second-order, four-factor Chinese version of the PPES provided best goodness-of-fit for the data in this study. Conclusion. The 11-item four-factor Chinese version of the PPES is a self-completion scale. This study demonstrated that the Chinese version of the PPES is a reliable and valid self-report instrument for the assessment of patient perceptions of empowerment in clinical practice. Further adaptation and evaluation of the scale will hopefully stimulate further studies on PPES in the fields of psychometrics in Taiwan. PMID:24971354
Nakae, Ken; Ikegaya, Yuji; Ishikawa, Tomoe; Oba, Shigeyuki; Urakubo, Hidetoshi; Koyama, Masanori; Ishii, Shin
2014-01-01
Crosstalk between neurons and glia may constitute a significant part of information processing in the brain. We present a novel method of statistically identifying interactions in a neuron–glia network. We attempted to identify neuron–glia interactions from neuronal and glial activities via maximum-a-posteriori (MAP)-based parameter estimation by developing a generalized linear model (GLM) of a neuron–glia network. The interactions in our interest included functional connectivity and response functions. We evaluated the cross-validated likelihood of GLMs that resulted from the addition or removal of connections to confirm the existence of specific neuron-to-glia or glia-to-neuron connections. We only accepted addition or removal when the modification improved the cross-validated likelihood. We applied the method to a high-throughput, multicellular in vitro Ca2+ imaging dataset obtained from the CA3 region of a rat hippocampus, and then evaluated the reliability of connectivity estimates using a statistical test based on a surrogate method. Our findings based on the estimated connectivity were in good agreement with currently available physiological knowledge, suggesting our method can elucidate undiscovered functions of neuron–glia systems. PMID:25393874
[Preventable drug-related morbidity: determining valid indicators for primary care in Portugal].
Guerreiro, Mara Pereira; Cantrill, Judith A; Martins, Ana Paula
2007-01-01
Preventable drug-related morbidity (PDRM) indicators are operational measures of therapeutic risk management. These clinical indicators, which cover a wide range of drugs, combine process and outcome in the same instrument. They were developed in the US and have been validated for primary care settings in the US, UK and Canada. This study is part of a research programme; it aimed to determine a valid set of PDRM indicators for adult patients in primary care in Portugal. Face validity of 61 US and UK-derived indicators translated to Portuguese was preliminarily determined by means of a postal questionnaire using a purposive sample of four Portuguese pharmacists with different backgrounds. Preliminary content validity of indicators approved in the previous stage was determined by cross-checking each definition of PDRM with standard drug information sources in Portugal. Face and content validity of indicators yielded by preliminary work were then established by a 37 expert panel (20 community pharmacists and 17 general practitioners) using a two-round Delphi survey. Data were analysed using SPSS release 11.5. Nineteen indicators were ruled out in preliminary validation. Changes were made in the content of eight of the remaining 42 indicators; these were related to differences in the drugs being marketed and patterns of drug monitoring between countries. Thirty-five indicators were consensus approved as PDRM for adult patients in Portuguese primary care by the Delphi panel.
Cross-Cultural adaptation of the General Functioning Scale of the Family
Pires, Thiago; de Assis, Simone Gonçalves; Avanci, Joviana Quintes; Pesce, Renata Pires
2016-01-01
ABSTRACT OBJECTIVE To describe the process of cross-cultural adaptation of the General Functioning Scale of the Family, a subscale of the McMaster Family Assessment Device, for the Brazilian population. METHODS The General Functioning Scale of the Family was translated into Portuguese and administered to 500 guardians of children in the second grade of elementary school in public schools of Sao Gonçalo, Rio de Janeiro, Southeastern Brazil. The types of equivalences investigated were: conceptual and of items, semantic, operational, and measurement. The study involved discussions with experts, translations and back-translations of the instrument, and psychometric assessment. Reliability and validity studies were carried out by internal consistency testing (Cronbach’s alpha), Guttman split-half correlation model, Pearson correlation coefficient, and confirmatory factor analysis. Associations between General Functioning of the Family and variables theoretically associated with the theme (father’s or mother’s drunkenness and violence between parents) were estimated by odds ratio. RESULTS Semantic equivalence was between 90.0% and 100%. Cronbach’s alpha ranged from 0.79 to 0.81, indicating good internal consistency of the instrument. Pearson correlation coefficient ranged between 0.303 and 0.549. Statistical association was found between the general functioning of the family score and the theoretically related variables, as well as good fit quality of the confirmatory analysis model. CONCLUSIONS The results indicate the feasibility of administering the instrument to the Brazilian population, as it is easy to understand and a good measurement of the construct of interest. PMID:27355464
Cross-cultural adaptation and validation of Persian Achilles tendon Total Rupture Score.
Ansari, Noureddin Nakhostin; Naghdi, Soofia; Hasanvand, Sahar; Fakhari, Zahra; Kordi, Ramin; Nilsson-Helander, Katarina
2016-04-01
To cross-culturally adapt the Achilles tendon Total Rupture Score (ATRS) to Persian language and to preliminary evaluate the reliability and validity of a Persian ATRS. A cross-sectional and prospective cohort study was conducted to translate and cross-culturally adapt the ATRS to Persian language (ATRS-Persian) following steps described in guidelines. Thirty patients with total Achilles tendon rupture and 30 healthy subjects participated in this study. Psychometric properties of floor/ceiling effects (responsiveness), internal consistency reliability, test-retest reliability, standard error of measurement (SEM), smallest detectable change (SDC), construct validity, and discriminant validity were tested. Factor analysis was performed to determine the ATRS-Persian structure. There were no floor or ceiling effects that indicate the content and responsiveness of ATRS-Persian. Internal consistency was high (Cronbach's α 0.95). Item-total correlations exceeded acceptable standard of 0.3 for the all items (0.58-0.95). The test-retest reliability was excellent [(ICC)agreement 0.98]. SEM and SDC were 3.57 and 9.9, respectively. Construct validity was supported by a significant correlation between the ATRS-Persian total score and the Persian Foot and Ankle Outcome Score (PFAOS) total score and PFAOS subscales (r = 0.55-0.83). The ATRS-Persian significantly discriminated between patients and healthy subjects. Explanatory factor analysis revealed 1 component. The ATRS was cross-culturally adapted to Persian and demonstrated to be a reliable and valid instrument to measure functional outcomes in Persian patients with Achilles tendon rupture. II.
Classification based upon gene expression data: bias and precision of error rates.
Wood, Ian A; Visscher, Peter M; Mengersen, Kerrie L
2007-06-01
Gene expression data offer a large number of potentially useful predictors for the classification of tissue samples into classes, such as diseased and non-diseased. The predictive error rate of classifiers can be estimated using methods such as cross-validation. We have investigated issues of interpretation and potential bias in the reporting of error rate estimates. The issues considered here are optimization and selection biases, sampling effects, measures of misclassification rate, baseline error rates, two-level external cross-validation and a novel proposal for detection of bias using the permutation mean. Reporting an optimal estimated error rate incurs an optimization bias. Downward bias of 3-5% was found in an existing study of classification based on gene expression data and may be endemic in similar studies. Using a simulated non-informative dataset and two example datasets from existing studies, we show how bias can be detected through the use of label permutations and avoided using two-level external cross-validation. Some studies avoid optimization bias by using single-level cross-validation and a test set, but error rates can be more accurately estimated via two-level cross-validation. In addition to estimating the simple overall error rate, we recommend reporting class error rates plus where possible the conditional risk incorporating prior class probabilities and a misclassification cost matrix. We also describe baseline error rates derived from three trivial classifiers which ignore the predictors. R code which implements two-level external cross-validation with the PAMR package, experiment code, dataset details and additional figures are freely available for non-commercial use from http://www.maths.qut.edu.au/profiles/wood/permr.jsp
Sisic, Nedim; Jelicic, Mario; Pehar, Miran; Spasic, Miodrag; Sekulic, Damir
2016-01-01
In basketball, anthropometric status is an important factor when identifying and selecting talents, while agility is one of the most vital motor performances. The aim of this investigation was to evaluate the influence of anthropometric variables and power capacities on different preplanned agility performances. The participants were 92 high-level, junior-age basketball players (16-17 years of age; 187.6±8.72 cm in body height, 78.40±12.26 kg in body mass), randomly divided into a validation and cross-validation subsample. The predictors set consisted of 16 anthropometric variables, three tests of power-capacities (Sargent-jump, broad-jump and medicine-ball-throw) as predictors. The criteria were three tests of agility: a T-Shape-Test; a Zig-Zag-Test, and a test of running with a 180-degree turn (T180). Forward stepwise multiple regressions were calculated for validation subsamples and then cross-validated. Cross validation included correlations between observed and predicted scores, dependent samples t-test between predicted and observed scores; and Bland Altman graphics. Analysis of the variance identified centres being advanced in most of the anthropometric indices, and medicine-ball-throw (all at P<0.05); with no significant between-position-differences for other studied motor performances. Multiple regression models originally calculated for the validation subsample were then cross-validated, and confirmed for Zig-zag-Test (R of 0.71 and 0.72 for the validation and cross-validation subsample, respectively). Anthropometrics were not strongly related to agility performance, but leg length is found to be negatively associated with performance in basketball-specific agility. Power capacities are confirmed to be an important factor in agility. The results highlighted the importance of sport-specific tests when studying pre-planned agility performance in basketball. The improvement in power capacities will probably result in an improvement in agility in basketball athletes, while anthropometric indices should be used in order to identify those athletes who can achieve superior agility performance.
Cross sections for electron impact excitation of the C 1Π and D 1Σ+ electronic states in N2O
NASA Astrophysics Data System (ADS)
Kawahara, H.; Suzuki, D.; Kato, H.; Hoshino, M.; Tanaka, H.; Ingólfsson, O.; Campbell, L.; Brunger, M. J.
2009-09-01
Differential and integral cross sections for electron-impact excitation of the dipole-allowed C Π1 and D Σ1+ electronic states of nitrous oxide have been measured. The differential cross sections were determined by analysis of normalized energy-loss spectra obtained using a crossed-beam apparatus at six electron energies in the range 15-200 eV. Integral cross sections were subsequently derived from these data. The present work was undertaken in order to check both the validity of the only other comprehensive experimental study into these excitation processes [Marinković et al., J. Phys. B 32, 1949 (1998)] and to extend the energy range of those data. Agreement with the earlier data, particularly at the lower common energies, was typically found to be fair. In addition, the BEf-scaling approach [Kim, J. Chem. Phys. 126, 064305 (2007)] is used to calculate integral cross sections for the C Π1 and D Σ1+ states, from their respective thresholds to 5000 eV. In general, good agreement is found between the experimental integral cross sections and those calculated within the BEf-scaling paradigm, the only exception being at the lowest energies of this study. Finally, optical oscillator strengths, also determined as a part of the present investigations, were found to be in fair accordance with previous corresponding determinations.
Dikken, Jeroen; Hoogerduijn, Jita G; Lagerwey, Mary D; Shortridge-Baggett, Lillie; Klaassen, Sharon; Schuurmans, Marieke J
In clinical practice, identifying positive and negative attitudes toward older patients is very important to improve quality of care provided to them. The Older People in Acute Care Survey - United States (OPACS-US) is an instrument measuring hospital nurses attitudes regarding older patients. However, psychometrics have never been assessed. Furthermore, knowledge being related to attitude and behavior should also be measured complementing the OPACS-US. The purpose of this study was to assess structural validity and reliability of the OPACS-US and assess whether the OPACS-US can be complemented with the Knowledge about Older Patients-Quiz (KOP-Q). A multicenter cross sectional design was conducted. Registered nurses (n = 130, mean age 39,9 years; working experience 14,6 years) working in four general hospitals were included in the study. Nurses completed the OPACS-US section A: practice experiences, B: general opinion and the KOP-Q online. Findings demonstrated that the OPACS-US is a valid and reliable survey instrument that measures practice experiences and general opinion. Furthermore, the OPACS-US can be combined with the KOP-Q adding a knowledge construct, and is ready for use within education and/or quality improvement programs in the USA. Copyright © 2017 Elsevier Inc. All rights reserved.
[An evaluation of the quality of health web pages using a validated questionnaire].
Conesa Fuentes, Maria del Carmen; Aguinaga Ontoso, Enrique; Hernández Morante, Juan José
2011-01-01
The objective of the present study was to evaluate the quality of general health information in Spanish language web pages, and the official Regional Services web pages from the different Autonomous Regions. It is a cross-sectional study. We have used a previously validated questionnaire to study the present state of the health information on Internet for a lay-user point of view. By mean of PageRank (Google®), we obtained a group of webs, including a total of 65 health web pages. We applied some exclusion criteria, and finally obtained a total of 36 webs. We also analyzed the official web pages from the different Health Services in Spain (19 webs), making a total of 54 health web pages. In the light of our data, we observed that, the quality of the general information health web pages was generally rather low, especially regarding the information quality. Not one page reached the maximum score (19 points). The mean score of the web pages was of 9.8±2.8. In conclusion, to avoid the problems arising from the lack of quality, health professionals should design advertising campaigns and other media to teach the lay-user how to evaluate the information quality. Copyright © 2009 Elsevier España, S.L. All rights reserved.
Ang, Hui-Gek; Koh, Jeremy Meng-Yeow; Lee, Jeffrey; Pua, Yong-Hao
2016-02-19
No instruments, to our knowledge, exist to assess leadership competency in existing and emerging allied health professional (AHP) leaders. This paper describes the development and preliminary exploration of the psychometric properties of a leadership competency instrument for existing and emerging AHP leaders and examines (i) its factor structure, (ii) its convergent validity with the Leadership Practices Inventory (LPI), and (iii) its discriminative validity in AHPs with different grades. During development, we included 25 items in the AHEAD (Aspiring leaders in Healthcare-Empowering individuals, Achieving excellence, Developing talents) instrument. A cross-sectional study was then conducted in 106 high-potential AHPs from Singapore General Hospital (34 men and 72 women) of different professional grades (49 principal-grade AHPs, 41 senior-grade AHPs, and 16 junior-grade AHPs) who completed both AHEAD and LPI instruments. Exploratory factor analysis was used to test the theoretical structure of AHEAD. Spearman correlation analysis was performed to evaluate the convergent validity of AHEAD with LPI. Using proportional odds regression models, we evaluated the association of grades of AHPs with AHEAD and LPI. To assess discriminative validity, the c-statistics - a measure of discrimination - were derived from these ordinal models. As theorized, factor analysis suggested a two-factor solution, where "skills" and "values" formed separate factors. Internal consistency of AHEAD was excellent (α-values > 0.88). Total and component AHEAD and LPI scores correlated moderately (Spearman ρ-values, 0.37 to 0.58). The c-index for discriminating between AHP grades was higher for AHEAD than for the LPI (0.76 vs. 0.65). The factorial structure of AHEAD was generally supported in our study. AHEAD showed convergent validity with the LPI and outperformed the LPI in terms of discriminative validity. These results provide initial evidence for the use of AHEAD to assess leadership competency in AHPs.
Genomic selection across multiple breeding cycles in applied bread wheat breeding.
Michel, Sebastian; Ametz, Christian; Gungor, Huseyin; Epure, Doru; Grausgruber, Heinrich; Löschenberger, Franziska; Buerstmayr, Hermann
2016-06-01
We evaluated genomic selection across five breeding cycles of bread wheat breeding. Bias of within-cycle cross-validation and methods for improving the prediction accuracy were assessed. The prospect of genomic selection has been frequently shown by cross-validation studies using the same genetic material across multiple environments, but studies investigating genomic selection across multiple breeding cycles in applied bread wheat breeding are lacking. We estimated the prediction accuracy of grain yield, protein content and protein yield of 659 inbred lines across five independent breeding cycles and assessed the bias of within-cycle cross-validation. We investigated the influence of outliers on the prediction accuracy and predicted protein yield by its components traits. A high average heritability was estimated for protein content, followed by grain yield and protein yield. The bias of the prediction accuracy using populations from individual cycles using fivefold cross-validation was accordingly substantial for protein yield (17-712 %) and less pronounced for protein content (8-86 %). Cross-validation using the cycles as folds aimed to avoid this bias and reached a maximum prediction accuracy of [Formula: see text] = 0.51 for protein content, [Formula: see text] = 0.38 for grain yield and [Formula: see text] = 0.16 for protein yield. Dropping outlier cycles increased the prediction accuracy of grain yield to [Formula: see text] = 0.41 as estimated by cross-validation, while dropping outlier environments did not have a significant effect on the prediction accuracy. Independent validation suggests, on the other hand, that careful consideration is necessary before an outlier correction is undertaken, which removes lines from the training population. Predicting protein yield by multiplying genomic estimated breeding values of grain yield and protein content raised the prediction accuracy to [Formula: see text] = 0.19 for this derived trait.
Dikken, Jeroen; Hoogerduijn, Jita G; Klaassen, Sharon; Lagerwey, Mary D; Shortridge-Baggett, Lillie; Schuurmans, Marieke J
2017-08-01
The Knowledge about Older Patients-Quiz (KOP-Q) is designed as a unidimensional scale measuring knowledge of hospital nurses about older patients. Furthermore, the KOP-Q measures a second unidimensional construct, certainty of hospital nurses about their knowledge. The KOP-Q is developed and validated in the Netherlands. Whether the KOP-Q can be used in other countries is unknown given the cultural and language differences. Investigate the level of measurement invariance of the KOP-Q between the Netherlands and United States of America (USA). A multicenter international cross-sectional design. Four general hospitals in the Netherlands and four general hospitals in the USA. Nurses from the Netherlands (n=201) and the USA (n=130) were invited to participate by email from the ward manager, distributing flyers and present messages on the online hospital communication boards. Questions of the KOP-Q were completed online. The level of measurement invariance (configural, metric or scalar invariance) across countries was tested by running increasingly constrained structural equation models, and testing whether these models fitted the data. Both the knowledge and certainty construct of the KOP-Q proved unidimensional in the Netherlands and USA sample. Test results of the measurement invariance across the Netherlands and USA indicated a stable, partial scalar invariance (15 items full scalar invariance) for the knowledge items and full scalar invariance for the certainty items. The KOP-Q shows to function uniformly across both language groups and can therefore be used to assess nurses' knowledge and their certainty about this knowledge which can be important for educational and/or quality improvement programs in the USA. Furthermore, the KOP-Q is suitable to make comparisons between the Netherlands and the USA using latent variable models. Before the KOP-Q can be used in other countries, cross-cultural tests should again be performed. Copyright © 2017 Elsevier Ltd. All rights reserved.
Reiss, Philip T
2015-08-01
The "ten ironic rules for statistical reviewers" presented by Friston (2012) prompted a rebuttal by Lindquist et al. (2013), which was followed by a rejoinder by Friston (2013). A key issue left unresolved in this discussion is the use of cross-validation to test the significance of predictive analyses. This note discusses the role that cross-validation-based and related hypothesis tests have come to play in modern data analyses, in neuroimaging and other fields. It is shown that such tests need not be suboptimal and can fill otherwise-unmet inferential needs. Copyright © 2015 Elsevier Inc. All rights reserved.
Accelerating cross-validation with total variation and its application to super-resolution imaging
NASA Astrophysics Data System (ADS)
Obuchi, Tomoyuki; Ikeda, Shiro; Akiyama, Kazunori; Kabashima, Yoshiyuki
2017-12-01
We develop an approximation formula for the cross-validation error (CVE) of a sparse linear regression penalized by ℓ_1-norm and total variation terms, which is based on a perturbative expansion utilizing the largeness of both the data dimensionality and the model. The developed formula allows us to reduce the necessary computational cost of the CVE evaluation significantly. The practicality of the formula is tested through application to simulated black-hole image reconstruction on the event-horizon scale with super resolution. The results demonstrate that our approximation reproduces the CVE values obtained via literally conducted cross-validation with reasonably good precision.
The cross-cultural validity of posttraumatic stress disorder: implications for DSM-5.
Hinton, Devon E; Lewis-Fernández, Roberto
2011-09-01
There is considerable debate about the cross-cultural applicability of the posttraumatic stress disorder (PTSD) category as currently specified. Concerns include the possible status of PTSD as a Western culture-bound disorder and the validity of individual items and criteria thresholds. This review examines various types of cross-cultural validity of the PTSD criteria as defined in DSM-IV-TR, and presents options and preliminary recommendations to be considered for DSM-5. Searches were conducted of the mental health literature, particularly since 1994, regarding cultural-, race-, or ethnicity-related factors that might limit the universal applicability of the diagnostic criteria of PTSD in DSM-IV-TR and the possible criteria for DSM-5. Substantial evidence of the cross-cultural validity of PTSD was found. However, evidence of cross-cultural variability in certain areas suggests the need for further research: the relative salience of avoidance/numbing symptoms, the role of the interpretation of trauma-caused symptoms in shaping symptomatology, and the prevalence of somatic symptoms. This review also indicates the need to modify certain criteria, such as the items on distressing dreams and on foreshortened future, to increase their cross-cultural applicability. Text additions are suggested to increase the applicability of the manual across cultural contexts: specifying that cultural syndromes-such as those indicated in the DSM-IV-TR Glossary-may be a prominent part of the trauma response in certain cultures, and that those syndromes may influence PTSD symptom salience and comorbidity. The DSM-IV-TR PTSD category demonstrates various types of validity. Criteria modification and textual clarifications are suggested to further improve its cross-cultural applicability. © 2010 Wiley-Liss, Inc.
Validity of the CAGE questionnaire for men who have sex with men (MSM) in China.
Chen, Yen-Tyng; Ibragimov, Umedjon; Nehl, Eric J; Zheng, Tony; He, Na; Wong, Frank Y
2016-03-01
Detection of heavy drinking among men who have sex with men (MSM) is crucial for both intervention and treatment. The CAGE questionnaire is a popular screening instrument for alcohol use problems. However, the validity of CAGE for Chinese MSM is unknown. Data were from three waves of cross-sectional assessments among general MSM (n=523) and men who sell sex to other men ("money boys" or MBs, n=486) in Shanghai, China. Specifically, participants were recruited using respondent-driven, community popular opinion leader, and venue-based sampling methods. The validity of the CAGE was examined for different cutoff scores and individual CAGE items using self-reported heavy drinking (≥14 drinks in the past week) as a criterion. In the full sample, 75 (7.4%) of participants were classified as heavy drinkers. 32 (6.1%) of general MSM and 43 (8.9%) of MBs were heavy drinkers. The area under curve statistics for overall sample was 0.7 (95% CI: 0.36-0.77). Overall, the sensitivities (ranging from 18.7 to 66.7%), specificities (ranging from 67.5 to 95.8%), and positive predictive values (ranging from 14.1 to 26.4%) for different cutoff scores were inadequate using past week heavy drinking as the criterion. The ability of CAGE to discriminate heavy drinkers from non-heavy drinkers was limited. Our findings showed the inadequate validity of CAGE as a screening instrument for current heavy drinking in Chinese MSM. Further research using a combination of validity criteria is needed to determine the applicability of CAGE for this population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
The MCNP6 Analytic Criticality Benchmark Suite
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brown, Forrest B.
2016-06-16
Analytical benchmarks provide an invaluable tool for verifying computer codes used to simulate neutron transport. Several collections of analytical benchmark problems [1-4] are used routinely in the verification of production Monte Carlo codes such as MCNP® [5,6]. Verification of a computer code is a necessary prerequisite to the more complex validation process. The verification process confirms that a code performs its intended functions correctly. The validation process involves determining the absolute accuracy of code results vs. nature. In typical validations, results are computed for a set of benchmark experiments using a particular methodology (code, cross-section data with uncertainties, and modeling)more » and compared to the measured results from the set of benchmark experiments. The validation process determines bias, bias uncertainty, and possibly additional margins. Verification is generally performed by the code developers, while validation is generally performed by code users for a particular application space. The VERIFICATION_KEFF suite of criticality problems [1,2] was originally a set of 75 criticality problems found in the literature for which exact analytical solutions are available. Even though the spatial and energy detail is necessarily limited in analytical benchmarks, typically to a few regions or energy groups, the exact solutions obtained can be used to verify that the basic algorithms, mathematics, and methods used in complex production codes perform correctly. The present work has focused on revisiting this benchmark suite. A thorough review of the problems resulted in discarding some of them as not suitable for MCNP benchmarking. For the remaining problems, many of them were reformulated to permit execution in either multigroup mode or in the normal continuous-energy mode for MCNP. Execution of the benchmarks in continuous-energy mode provides a significant advance to MCNP verification methods.« less
Characterizing the functional MRI response using Tikhonov regularization.
Vakorin, Vasily A; Borowsky, Ron; Sarty, Gordon E
2007-09-20
The problem of evaluating an averaged functional magnetic resonance imaging (fMRI) response for repeated block design experiments was considered within a semiparametric regression model with autocorrelated residuals. We applied functional data analysis (FDA) techniques that use a least-squares fitting of B-spline expansions with Tikhonov regularization. To deal with the noise autocorrelation, we proposed a regularization parameter selection method based on the idea of combining temporal smoothing with residual whitening. A criterion based on a generalized chi(2)-test of the residuals for white noise was compared with a generalized cross-validation scheme. We evaluated and compared the performance of the two criteria, based on their effect on the quality of the fMRI response. We found that the regularization parameter can be tuned to improve the noise autocorrelation structure, but the whitening criterion provides too much smoothing when compared with the cross-validation criterion. The ultimate goal of the proposed smoothing techniques is to facilitate the extraction of temporal features in the hemodynamic response for further analysis. In particular, these FDA methods allow us to compute derivatives and integrals of the fMRI signal so that fMRI data may be correlated with behavioral and physiological models. For example, positive and negative hemodynamic responses may be easily and robustly identified on the basis of the first derivative at an early time point in the response. Ultimately, these methods allow us to verify previously reported correlations between the hemodynamic response and the behavioral measures of accuracy and reaction time, showing the potential to recover new information from fMRI data. 2007 John Wiley & Sons, Ltd
Ko, Jupil; Rosen, Adam B; Brown, Cathleen N
2015-12-01
The Cumberland Ankle Instability Tool (CAIT) is a valid and reliable patient reported outcome used to assess the presence and severity of chronic ankle instability (CAI). The CAIT has been cross-culturally adapted into other languages for use in non-English speaking populations. However, there are no valid questionnaires to assess CAI in individuals who speak Korean. The purpose of this study was to translate, cross-culturally adapt, and validate the CAIT, for use in a Korean-speaking population with CAI. Cross-cultural reliability study. The CAIT was cross-culturally adapted into Korean according to accepted guidelines and renamed the Cumberland Ankle Instability Tool-Korean (CAIT-K). Twenty-three participants (12 males, 11 females) who were bilingual in English and Korean were recruited and completed the original and adapted versions to assess agreement between versions. An additional 168 national level Korean athletes (106 male, 62 females; age = 20.3 ± 1.1 yrs), who participated in ≥ 90 minutes of physical activity per week, completed the final version of the CAIT-K twice within 14 days. Their completed questionnaires were assessed for internal consistency, test-retest reliability, criterion validity, and construct validity. For bilingual participants, intra-class correlation coefficients (ICC2,1) between the CAIT and the CAIT-K for test-retest reliability were 0.95 (SEM=1.83) and 0.96 (SEM=1.50) in right and left limbs, respectively. The Cronbach's alpha coefficients were 0.92 and 0.90 for the CAIT-K in right and left limbs, respectively. For native Korean speakers, the CAIT-K had high internal consistency (Cronbach's α=0.89) and intra-class correlation coefficient (ICC2,1 = 0.94, SEM=1.72), correlation with the physical component score (rho=0.70, p = 0.001) of the Short-Form Health Survey (SF-36), and the Kaiser-Meyer-Olkin score was 0.87. The original CAIT was translated, cross-culturally adapted, and validated from English to Korean. The CAIT-K appears to be valid and reliable and could be useful in assessing the Korean speaking population with CAI.
Zhang, Yin-Ping; Wei, Huan-Huan; Wang, Wen; Xia, Ru-Yi; Zhou, Xiao-Ling; Porr, Caroline; Lammi, Mikko
2016-04-01
The Osteoporosis Assessment Questionnaire Short Version (OPAQ-SV) was cross-culturally adapted to measure health-related quality of life in Chinese osteoporotic fracture females and then validated in China for its psychometric properties. Cross-cultural adaptation, including translation of the original OPAQ-SV into Mandarin Chinese language, was performed according to published guidelines. Validation of the newly cross-culturally adapted OPAQ-SV was conducted by sampling 234 Chinese osteoporotic fracture females and also a control group of 235 Chinese osteoporotic females without fractures, producing robust content, construct, and discriminant validation results. Major categories of reliability were also met: the Cronbach alpha coefficient was 0.975, indicating good internal consistency; the test-retest reliability was 0.80; and principal component analysis resulted in a 6-factor structure explaining 75.847 % of the total variance. Further, the Comparative Fit Index result was 0.922 following the modified model confirmatory factor analysis, and the chi-squared test was 1.98. The root mean squared error of approximation was 0.078. Moreover, significant differences were revealed between females with fractures and those without fractures across all domains (p < 0.001). Overall, the newly cross-culturally adapted OPAQ-SV appears to possess adequate validity and reliability and may be utilized in clinical trials to assess the health-related quality of life in Chinese osteoporotic fracture females.
Correcting for Optimistic Prediction in Small Data Sets
Smith, Gordon C. S.; Seaman, Shaun R.; Wood, Angela M.; Royston, Patrick; White, Ian R.
2014-01-01
The C statistic is a commonly reported measure of screening test performance. Optimistic estimation of the C statistic is a frequent problem because of overfitting of statistical models in small data sets, and methods exist to correct for this issue. However, many studies do not use such methods, and those that do correct for optimism use diverse methods, some of which are known to be biased. We used clinical data sets (United Kingdom Down syndrome screening data from Glasgow (1991–2003), Edinburgh (1999–2003), and Cambridge (1990–2006), as well as Scottish national pregnancy discharge data (2004–2007)) to evaluate different approaches to adjustment for optimism. We found that sample splitting, cross-validation without replication, and leave-1-out cross-validation produced optimism-adjusted estimates of the C statistic that were biased and/or associated with greater absolute error than other available methods. Cross-validation with replication, bootstrapping, and a new method (leave-pair-out cross-validation) all generated unbiased optimism-adjusted estimates of the C statistic and had similar absolute errors in the clinical data set. Larger simulation studies confirmed that all 3 methods performed similarly with 10 or more events per variable, or when the C statistic was 0.9 or greater. However, with lower events per variable or lower C statistics, bootstrapping tended to be optimistic but with lower absolute and mean squared errors than both methods of cross-validation. PMID:24966219
Cross-cultural adaption and validation of the Persian version of the SWAL-QOL.
Tarameshlu, Maryam; Azimi, Amir Reza; Jalaie, Shohreh; Ghelichi, Leila; Ansari, Noureddin Nakhostin
2017-06-01
The aim of this study was to translate and cross-culturally adapt the swallowing quality-of-life questionnaire (SWAL-QOL) to Persian language and to determine validity and reliability of the Persian version of the swallow quality-of-life questionnaire (PSWAL-QOL) in the patients with oropharyngeal dysphagia.The cross-sectional survey was designed to translate and cross-culturally adapt SWAL-QOL to Persian language following steps recommended in guideline. A total of 142 patients with dysphagia (mean age = 56.7 ± 12.22 years) were selected by non-probability consecutive sampling method to evaluate construct validity and internal consistency. Thirty patients with dysphagia were completed the PSWAL-QOL 2 weeks later for test-retest reliability.The PSWAL-QOL was favorably accepted with no missing items. The floor effect was ranged 0% to 21% and ceiling effect was ranged 0% to 16%. The construct validity was established via exploratory factor analysis. Internal consistency was confirmed with Cronbach α >0.7 for all scales except eating duration (α = 0.68). The test-retest reliability was excellent with intraclass correlation coefficient (ICC) ≥0.75 for all scales.The SWAL-QOL was cross-culturally adapted to Persian and demonstrated to be a valid and reliable self-report questionnaire to measure the impact of dysphagia on the quality-of-life in the Persian patients with oropharyngeal dysphagia.
Cross-cultural adaption and validation of the Persian version of the SWAL-QOL
Tarameshlu, Maryam; Azimi, Amir Reza; Jalaie, Shohreh; Ghelichi, Leila; Ansari, Noureddin Nakhostin
2017-01-01
Abstract The aim of this study was to translate and cross-culturally adapt the swallowing quality-of-life questionnaire (SWAL-QOL) to Persian language and to determine validity and reliability of the Persian version of the swallow quality-of-life questionnaire (PSWAL-QOL) in the patients with oropharyngeal dysphagia. The cross-sectional survey was designed to translate and cross-culturally adapt SWAL-QOL to Persian language following steps recommended in guideline. A total of 142 patients with dysphagia (mean age = 56.7 ± 12.22 years) were selected by non-probability consecutive sampling method to evaluate construct validity and internal consistency. Thirty patients with dysphagia were completed the PSWAL-QOL 2 weeks later for test–retest reliability. The PSWAL-QOL was favorably accepted with no missing items. The floor effect was ranged 0% to 21% and ceiling effect was ranged 0% to 16%. The construct validity was established via exploratory factor analysis. Internal consistency was confirmed with Cronbach α >0.7 for all scales except eating duration (α = 0.68). The test–retest reliability was excellent with intraclass correlation coefficient (ICC) ≥0.75 for all scales. The SWAL-QOL was cross-culturally adapted to Persian and demonstrated to be a valid and reliable self-report questionnaire to measure the impact of dysphagia on the quality-of-life in the Persian patients with oropharyngeal dysphagia. PMID:28658118
Genomic Prediction of Single Crosses in the Early Stages of a Maize Hybrid Breeding Pipeline.
Kadam, Dnyaneshwar C; Potts, Sarah M; Bohn, Martin O; Lipka, Alexander E; Lorenz, Aaron J
2016-09-19
Prediction of single-cross performance has been a major goal of plant breeders since the beginning of hybrid breeding. Recently, genomic prediction has shown to be a promising approach, but only limited studies have examined the accuracy of predicting single-cross performance. Moreover, no studies have examined the potential of predicting single crosses among random inbreds derived from a series of biparental families, which resembles the structure of germplasm comprising the initial stages of a hybrid maize breeding pipeline. The main objectives of this study were to evaluate the potential of genomic prediction for identifying superior single crosses early in the hybrid breeding pipeline and optimize its application. To accomplish these objectives, we designed and analyzed a novel population of single crosses representing the Iowa Stiff Stalk Synthetic/Non-Stiff Stalk heterotic pattern commonly used in the development of North American commercial maize hybrids. The performance of single crosses was predicted using parental combining ability and covariance among single crosses. Prediction accuracies were estimated using cross-validation and ranged from 0.28 to 0.77 for grain yield, 0.53 to 0.91 for plant height, and 0.49 to 0.94 for staygreen, depending on the number of tested parents of the single cross and genomic prediction method used. The genomic estimated general and specific combining abilities showed an advantage over genomic covariances among single crosses when one or both parents of the single cross were untested. Overall, our results suggest that genomic prediction of single crosses in the early stages of a hybrid breeding pipeline holds great potential to re-design hybrid breeding and increase its efficiency. Copyright © 2016 Author et al.
Barnard, Patrick L.; Erikson, Li H.; Elias, Edwin P.L.; Dartnell, Peter
2013-01-01
The morphology of ~ 45,000 bedforms from 13 multibeam bathymetry surveys was used as a proxy for identifying net bedload sediment transport directions and pathways throughout the San Francisco Bay estuary and adjacent outer coast. The spatially-averaged shape asymmetry of the bedforms reveals distinct pathways of ebb and flood transport. Additionally, the region-wide, ebb-oriented asymmetry of 5% suggests net seaward-directed transport within the estuarine-coastal system, with significant seaward asymmetry at the mouth of San Francisco Bay (11%), through the northern reaches of the Bay (7-8%), and among the largest bedforms (21% for λ > 50 m). This general indication for the net transport of sand to the open coast strongly suggests that anthropogenic removal of sediment from the estuary, particularly along clearly defined seaward transport pathways, will limit the supply of sand to chronically eroding, open-coast beaches. The bedform asymmetry measurements significantly agree (up to ~ 76%) with modeled annual residual transport directions derived from a hydrodynamically-calibrated numerical model, and the orientation of adjacent, flow-sculpted seafloor features such as mega-flute structures, providing a comprehensive validation of the technique. The methods described in this paper to determine well-defined, cross-validated sediment transport pathways can be applied to estuarine-coastal systems globally where bedforms are present. The results can inform and improve regional sediment management practices to more efficiently utilize often limited sediment resources and mitigate current and future sediment supply-related impacts.
Barnard, Patrick L.; Erikson, Li H.; Elias, Edwin P.L.; Dartnell, Peter; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.
2013-01-01
The morphology of ~ 45,000 bedforms from 13 multibeam bathymetry surveys was used as a proxy for identifying net bedload sediment transport directions and pathways throughout the San Francisco Bay estuary and adjacent outer coast. The spatially-averaged shape asymmetry of the bedforms reveals distinct pathways of ebb and flood transport. Additionally, the region-wide, ebb-oriented asymmetry of 5% suggests net seaward-directed transport within the estuarine-coastal system, with significant seaward asymmetry at the mouth of San Francisco Bay (11%), through the northern reaches of the Bay (7–8%), and among the largest bedforms (21% for λ > 50 m). This general indication for the net transport of sand to the open coast strongly suggests that anthropogenic removal of sediment from the estuary, particularly along clearly defined seaward transport pathways, will limit the supply of sand to chronically eroding, open-coast beaches. The bedform asymmetry measurements significantly agree (up to ~ 76%) with modeled annual residual transport directions derived from a hydrodynamically-calibrated numerical model, and the orientation of adjacent, flow-sculpted seafloor features such as mega-flute structures, providing a comprehensive validation of the technique. The methods described in this paper to determine well-defined, cross-validated sediment transport pathways can be applied to estuarine-coastal systems globally where bedforms are present. The results can inform and improve regional sediment management practices to more efficiently utilize often limited sediment resources and mitigate current and future sediment supply-related impacts.
Berg, M; Aamodt, G; Stanghelle, J; Krumlinde-Sundholm, L; Hussain, A
2008-09-01
The Pediatric Evaluation of Disability Inventory (PEDI) is one of the most commonly used assessments for children with a disability. Normative data from the US are used to determine whether a deficit or delay exists with regard to functional skill development. The purpose of this study was to analyse the cross-cultural validity of the PEDI American normative data for a general Norwegian population. A random selection of 174 typically developed Norwegian children between 1.0 and 5.9 years participated. The results for capability and caregiver assistance in the domains of self-care, mobility, and social function ranged from a mean of 38.0-46.8 against an expected 50. The Norwegian sample scored significantly lower than the US reference values for functional skills and caregiver assistance, and the results had less fit, especially for self-care. For mobility and social function, the magnitudes of the differences were smaller than self-care. Specific items deviated, suggesting necessary adjustments for the applicability of the norm-referenced scores of the PEDI in the Norwegian culture. The result of this research confirms other findings of cultural influence of the age norms in PEDI. Even though interpretations of the normative score results must be made with some caution, the option of using the scaled scores of PEDI is useful and recommended to describe and measure abilities and to evaluate change. This finding highlights the importance of cultural validation of norm-referenced tests.
Mograbi, Daniel C; Indelli, Pamela; Lage, Caio A; Tebyriça, Vitória; Landeira-Fernandez, Jesus; Rimes, Katharine A
2018-03-01
Introduction Beliefs about the unacceptability of expression and experience of emotion are present in the general population but seem to be more prevalent in patients with a number of health conditions. Such beliefs, which may be viewed as a form of perfectionism about emotions, may have a deleterious effect on symptomatology as well as on treatment adherence and outcome. Nevertheless, few questionnaires have been developed to measure such beliefs about emotions, and no instrument has been validated in a developing country. The current study adapted and validated the Beliefs about Emotions Scale in a Brazilian sample. Methods The adaptation procedure included translation, back-translation and analysis of the content, with the final Brazilian Portuguese version of the scale being tested online in a sample of 645 participants. Internal consistency of the scale was very high and results of a principal axis factoring analysis indicated a two-factor solution. Results Respondents with high fatigue levels showed more perfectionist beliefs, and the scale correlated positively with questionnaires measuring anxiety, depression and fear of negative evaluation, confirming cross-cultural associations reported before. Finally, men, non-Caucasians and participants with lower educational achievement gave greater endorsement to such beliefs than women, Caucasian individuals and participants with higher educational level. Conclusions The study confirms previous clinical findings reported in the literature, but indicates novel associations with demographic variables. The latter may reflect cultural differences related to beliefs about emotions in Brazil.
Predicting prolonged dose titration in patients starting warfarin.
Finkelman, Brian S; French, Benjamin; Bershaw, Luanne; Brensinger, Colleen M; Streiff, Michael B; Epstein, Andrew E; Kimmel, Stephen E
2016-11-01
Patients initiating warfarin therapy generally experience a dose-titration period of weeks to months, during which time they are at higher risk of both thromboembolic and bleeding events. Accurate prediction of prolonged dose titration could help clinicians determine which patients might be better treated by alternative anticoagulants that, while more costly, do not require dose titration. A prediction model was derived in a prospective cohort of patients starting warfarin (n = 390), using Cox regression, and validated in an external cohort (n = 663) from a later time period. Prolonged dose titration was defined as a dose-titration period >12 weeks. Predictor variables were selected using a modified best subsets algorithm, using leave-one-out cross-validation to reduce overfitting. The final model had five variables: warfarin indication, insurance status, number of doctor's visits in the previous year, smoking status, and heart failure. The area under the ROC curve (AUC) in the derivation cohort was 0.66 (95%CI 0.60, 0.74) using leave-one-out cross-validation, but only 0.59 (95%CI 0.54, 0.64) in the external validation cohort, and varied across clinics. Including genetic factors in the model did not improve the area under the ROC curve (0.59; 95%CI 0.54, 0.65). Relative utility curves indicated that the model was unlikely to provide a clinically meaningful benefit compared with no prediction. Our results suggest that prolonged dose titration cannot be accurately predicted in warfarin patients using traditional clinical, social, and genetic predictors, and that accurate prediction will need to accommodate heterogeneities across clinical sites and over time. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
Reed, Darcy A; Beckman, Thomas J; Wright, Scott M; Levine, Rachel B; Kern, David E; Cook, David A
2008-07-01
Deficiencies in medical education research quality are widely acknowledged. Content, internal structure, and criterion validity evidence support the use of the Medical Education Research Study Quality Instrument (MERSQI) to measure education research quality, but predictive validity evidence has not been explored. To describe the quality of manuscripts submitted to the 2008 Journal of General Internal Medicine (JGIM) medical education issue and determine whether MERSQI scores predict editorial decisions. Cross-sectional study of original, quantitative research studies submitted for publication. Study quality measured by MERSQI scores (possible range 5-18). Of 131 submitted manuscripts, 100 met inclusion criteria. The mean (SD) total MERSQI score was 9.6 (2.6), range 5-15.5. Most studies used single-group cross-sectional (54%) or pre-post designs (32%), were conducted at one institution (78%), and reported satisfaction or opinion outcomes (56%). Few (36%) reported validity evidence for evaluation instruments. A one-point increase in MERSQI score was associated with editorial decisions to send manuscripts for peer review versus reject without review (OR 1.31, 95%CI 1.07-1.61, p = 0.009) and to invite revisions after review versus reject after review (OR 1.29, 95%CI 1.05-1.58, p = 0.02). MERSQI scores predicted final acceptance versus rejection (OR 1.32; 95% CI 1.10-1.58, p = 0.003). The mean total MERSQI score of accepted manuscripts was significantly higher than rejected manuscripts (10.7 [2.5] versus 9.0 [2.4], p = 0.003). MERSQI scores predicted editorial decisions and identified areas of methodological strengths and weaknesses in submitted manuscripts. Researchers, reviewers, and editors might use this instrument as a measure of methodological quality.
Stikic, Maja; Berka, Chris; Levendowski, Daniel J.; Rubio, Roberto F.; Tan, Veasna; Korszen, Stephanie; Barba, Douglas; Wurzer, David
2014-01-01
The objective of this study was to investigate the feasibility of physiological metrics such as ECG-derived heart rate and EEG-derived cognitive workload and engagement as potential predictors of performance on different training tasks. An unsupervised approach based on self-organizing neural network (NN) was utilized to model cognitive state changes over time. The feature vector comprised EEG-engagement, EEG-workload, and heart rate metrics, all self-normalized to account for individual differences. During the competitive training process, a linear topology was developed where the feature vectors similar to each other activated the same NN nodes. The NN model was trained and auto-validated on combat marksmanship training data from 51 participants that were required to make “deadly force decisions” in challenging combat scenarios. The trained NN model was cross validated using 10-fold cross-validation. It was also validated on a golf study in which additional 22 participants were asked to complete 10 sessions of 10 putts each. Temporal sequences of the activated nodes for both studies followed the same pattern of changes, demonstrating the generalization capabilities of the approach. Most node transition changes were local, but important events typically caused significant changes in the physiological metrics, as evidenced by larger state changes. This was investigated by calculating a transition score as the sum of subsequent state transitions between the activated NN nodes. Correlation analysis demonstrated statistically significant correlations between the transition scores and subjects' performances in both studies. This paper explored the hypothesis that temporal sequences of physiological changes comprise the discriminative patterns for performance prediction. These physiological markers could be utilized in future training improvement systems (e.g., through neurofeedback), and applied across a variety of training environments. PMID:25414629
Calibration of the Dutch-Flemish PROMIS Pain Behavior item bank in patients with chronic pain.
Crins, M H P; Roorda, L D; Smits, N; de Vet, H C W; Westhovens, R; Cella, D; Cook, K F; Revicki, D; van Leeuwen, J; Boers, M; Dekker, J; Terwee, C B
2016-02-01
The aims of the current study were to calibrate the item parameters of the Dutch-Flemish PROMIS Pain Behavior item bank using a sample of Dutch patients with chronic pain and to evaluate cross-cultural validity between the Dutch-Flemish and the US PROMIS Pain Behavior item banks. Furthermore, reliability and construct validity of the Dutch-Flemish PROMIS Pain Behavior item bank were evaluated. The 39 items in the bank were completed by 1042 Dutch patients with chronic pain. To evaluate unidimensionality, a one-factor confirmatory factor analysis (CFA) was performed. A graded response model (GRM) was used to calibrate the items. To evaluate cross-cultural validity, Differential item functioning (DIF) for language (Dutch vs. English) was evaluated. Reliability of the item bank was also examined and construct validity was studied using several legacy instruments, e.g. the Roland Morris Disability Questionnaire. CFA supported the unidimensionality of the Dutch-Flemish PROMIS Pain Behavior item bank (CFI = 0.960, TLI = 0.958), the data also fit the GRM, and demonstrated good coverage across the pain behavior construct (threshold parameters range: -3.42 to 3.54). Analysis showed good cross-cultural validity (only six DIF items), reliability (Cronbach's α = 0.95) and construct validity (all correlations ≥0.53). The Dutch-Flemish PROMIS Pain Behavior item bank was found to have good cross-cultural validity, reliability and construct validity. The development of the Dutch-Flemish PROMIS Pain Behavior item bank will serve as the basis for Dutch-Flemish PROMIS short forms and computer adaptive testing (CAT). © 2015 European Pain Federation - EFIC®
Ruperto, N; Ravelli, A; Pistorio, A; Malattia, C; Cavuto, S; Gado-West, L; Tortorelli, A; Landgraf, J M; Singh, G; Martini, A
2001-01-01
The aim of this project was to cross-culturally adapt and validate the American English version of the Childhood Health Assessment Questionnaire (CHAQ) and of the Child Health Questionnaire (CHQ) in the 32 different member countries of the Paediatric Rheumatology International Trials Organisation (PRINTO). This effort forms part of an international study supported by the European Union to evaluate the health-related quality of life in children with juvenile idiopathic arthritis (JIA) as compared to their healthy peers. A total of 6,644 subjects were enrolled from 32 countries: Argentina, Austria, Belgium, Brazil, Bulgaria, Chile, Croatia, the Czech Republic, Denmark, Finland, France, Georgia, Germany, Greece, Hungary, Israel, Italy, Korea, Latvia, Mexico, the Netherlands, Norway, Poland, Portugal, Russia, Slovakia, Spain, Sweden, Switzerland, Turkey, the United Kingdom, and Yugoslavia. A total of 3,235 patients had JIA (20% systemic onset, 33% polyarticular onset, 17% extended oligoarticular subtype, and 30% persistent oligoarticular subtype) while 3,409 were healthy children. This introductory paper describes the methodology used by all the participants. The results and the translated version of both the CHAQ and the CHQ for each country are fully reported in the following papers. The results of the present study show that cross-cultural adaptation is a valid process to obtain reliable instruments for the different socio-economic and socio-demographic conditions of the countries participating in the project.
Comparative assessment of three standardized robotic surgery training methods.
Hung, Andrew J; Jayaratna, Isuru S; Teruya, Kara; Desai, Mihir M; Gill, Inderbir S; Goh, Alvin C
2013-10-01
To evaluate three standardized robotic surgery training methods, inanimate, virtual reality and in vivo, for their construct validity. To explore the concept of cross-method validity, where the relative performance of each method is compared. Robotic surgical skills were prospectively assessed in 49 participating surgeons who were classified as follows: 'novice/trainee': urology residents, previous experience <30 cases (n = 38) and 'experts': faculty surgeons, previous experience ≥30 cases (n = 11). Three standardized, validated training methods were used: (i) structured inanimate tasks; (ii) virtual reality exercises on the da Vinci Skills Simulator (Intuitive Surgical, Sunnyvale, CA, USA); and (iii) a standardized robotic surgical task in a live porcine model with performance graded by the Global Evaluative Assessment of Robotic Skills (GEARS) tool. A Kruskal-Wallis test was used to evaluate performance differences between novices and experts (construct validity). Spearman's correlation coefficient (ρ) was used to measure the association of performance across inanimate, simulation and in vivo methods (cross-method validity). Novice and expert surgeons had previously performed a median (range) of 0 (0-20) and 300 (30-2000) robotic cases, respectively (P < 0.001). Construct validity: experts consistently outperformed residents with all three methods (P < 0.001). Cross-method validity: overall performance of inanimate tasks significantly correlated with virtual reality robotic performance (ρ = -0.7, P < 0.001) and in vivo robotic performance based on GEARS (ρ = -0.8, P < 0.0001). Virtual reality performance and in vivo tissue performance were also found to be strongly correlated (ρ = 0.6, P < 0.001). We propose the novel concept of cross-method validity, which may provide a method of evaluating the relative value of various forms of skills education and assessment. We externally confirmed the construct validity of each featured training tool. © 2013 BJU International.
Attrition from an Adolescent Addiction Treatment Program: A Cross Validation.
ERIC Educational Resources Information Center
Mathisen, Kenneth S.; Meyers, Kathleen
Treatment attrition is a major problem for programs treating adolescent substance abusers. To isolate and cross validate factors which are predictive of addiction treatment attrition among adolescent substance abusers, screening interview and diagnostic variables from 119 adolescent in-patients were submitted to a discriminant equation analysis.…
Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-23
... Proposed Rule Change To Eliminate the Validated Cross Trade Entry Functionality December 16, 2010. Pursuant... eliminate the Validated Cross Trade Entry Functionality for Exchange-registered Institutional Brokers. The... Brokers (``Institutional Brokers'') by eliminating the ability of an Institutional Broker to execute...
Cross-Cultural Validation of TEMAS, a Minority Projective Test.
ERIC Educational Resources Information Center
Costantino, Giuseppe; And Others
The theoretical framework and cross-cultural validation of Tell-Me-A-Story (TEMAS), a projective test developed to measure personality development in ethnic minority children, is presented. The TEMAS test consists of 23 chromatic pictures which incorporate the following characteristics: (1) representation of antithetical concepts which the…
Genome-based prediction of test cross performance in two subsequent breeding cycles.
Hofheinz, Nina; Borchardt, Dietrich; Weissleder, Knuth; Frisch, Matthias
2012-12-01
Genome-based prediction of genetic values is expected to overcome shortcomings that limit the application of QTL mapping and marker-assisted selection in plant breeding. Our goal was to study the genome-based prediction of test cross performance with genetic effects that were estimated using genotypes from the preceding breeding cycle. In particular, our objectives were to employ a ridge regression approach that approximates best linear unbiased prediction of genetic effects, compare cross validation with validation using genetic material of the subsequent breeding cycle, and investigate the prospects of genome-based prediction in sugar beet breeding. We focused on the traits sugar content and standard molasses loss (ML) and used a set of 310 sugar beet lines to estimate genetic effects at 384 SNP markers. In cross validation, correlations >0.8 between observed and predicted test cross performance were observed for both traits. However, in validation with 56 lines from the next breeding cycle, a correlation of 0.8 could only be observed for sugar content, for standard ML the correlation reduced to 0.4. We found that ridge regression based on preliminary estimates of the heritability provided a very good approximation of best linear unbiased prediction and was not accompanied with a loss in prediction accuracy. We conclude that prediction accuracy assessed with cross validation within one cycle of a breeding program can not be used as an indicator for the accuracy of predicting lines of the next cycle. Prediction of lines of the next cycle seems promising for traits with high heritabilities.
Estrada Álvarez, Jorge M; Ossa García, Ximena; del Quijano del Gordo, Carmen I; Bustos, Luis; Urina, Diana P; Pérez, Celso F; Ossa, John E; Moreno Rojas, Edwin
2015-08-01
To assess the validity and reliability of the chronic respiratory questionnaire (CRQ) in the measurement of HRQL in the Colombian population with COPD. A cross-sectional study was conducted with a sample of 200 patients diagnosed with COPD according to GOLD criteria. Convergence validity was evaluated by correlating the questionnaire results with other clinical variables such as exercise tolerance, forced expiratory volume at the first second (FEV1), and depression levels. HRQL measured through the CRQ correlated significantly with the 6-min walk test (r = 0.34), just as the dimensions fatigue (r = 0.37) and dyspnoea correlated with the FEV1 test (r = 0.21) and the dimensions emotional function and disease management with depression levels (r = -0.79). The Generalized Structured Component Analysis (GSCA) with the prespecified model is showed, and the total variance explained by the items in the model was 61.5 % (FIT = 0.615), unweighted least squares (GFI = 0.998), and standardised root mean square (SRMR = 0.084), indicating that the model fits adequately. The CRQ presents evidence of adequate validity and reliability in the Colombian population. Its use is recommended to measure HRQL in patients with COPD, although future validations will be needed to identify the property of sensitivity to change.
NASA Astrophysics Data System (ADS)
Ranaie, Mehrdad; Soffianian, Alireza; Pourmanafi, Saeid; Mirghaffari, Noorollah; Tarkesh, Mostafa
2018-03-01
In recent decade, analyzing the remotely sensed imagery is considered as one of the most common and widely used procedures in the environmental studies. In this case, supervised image classification techniques play a central role. Hence, taking a high resolution Worldview-3 over a mixed urbanized landscape in Iran, three less applied image classification methods including Bagged CART, Stochastic gradient boosting model and Neural network with feature extraction were tested and compared with two prevalent methods: random forest and support vector machine with linear kernel. To do so, each method was run ten time and three validation techniques was used to estimate the accuracy statistics consist of cross validation, independent validation and validation with total of train data. Moreover, using ANOVA and Tukey test, statistical difference significance between the classification methods was significantly surveyed. In general, the results showed that random forest with marginal difference compared to Bagged CART and stochastic gradient boosting model is the best performing method whilst based on independent validation there was no significant difference between the performances of classification methods. It should be finally noted that neural network with feature extraction and linear support vector machine had better processing speed than other.
Glassmire, David M; Toofanian Ross, Parnian; Kinney, Dominique I; Nitch, Stephen R
2016-06-01
Two studies were conducted to identify and cross-validate cutoff scores on the Wechsler Adult Intelligence Scale-Fourth Edition Digit Span-based embedded performance validity (PV) measures for individuals with schizophrenia spectrum disorders. In Study 1, normative scores were identified on Digit Span-embedded PV measures among a sample of patients (n = 84) with schizophrenia spectrum diagnoses who had no known incentive to perform poorly and who put forth valid effort on external PV tests. Previously identified cutoff scores resulted in unacceptable false positive rates and lower cutoff scores were adopted to maintain specificity levels ≥90%. In Study 2, the revised cutoff scores were cross-validated within a sample of schizophrenia spectrum patients (n = 96) committed as incompetent to stand trial. Performance on Digit Span PV measures was significantly related to Full Scale IQ in both studies, indicating the need to consider the intellectual functioning of examinees with psychotic spectrum disorders when interpreting scores on Digit Span PV measures. © The Author(s) 2015.
Joshi, Veena D; Mooppil, Nandakumar; Lim, Jeremy Fy
2010-12-20
In Singapore, the prevalence of end-stage renal disease (ESRD) and the number of people on dialysis is increasing. The impact of ESRD on patient quality of life has been recognized as an important outcome measure. The Kidney Disease Quality Of Life-Short Form (KDQOL-SF™) has been validated and is widely used as a measure of quality of life in dialysis patients in many countries, but not in Singapore. We aimed to determine the reliability and validity of the KDQOL-SF™ for haemodialysis patients in Singapore. From December 2006 through January 2007, this cross-sectional study gathered data on patients ≥21 years old, who were undergoing haemodialysis at National Kidney Foundation in Singapore. We used exploratory factor analysis to determine construct validity of the eight KDQOL-SF™ sub-scales, Cronbach's alpha coefficient to determine internal consistency reliability, correlation of the overall health rating with kidney disease-targeted scales to confirm validity, and correlation of the eight sub-scales with age, income and education to determine convergent and divergent validity. Of 1980 haemodialysis patients, 1180 (59%) completed the KDQOL-SF™. Full information was available for 980 participants, with a mean age of 56 years. The sample was representative of the total dialysis population in Singapore, except Indian ethnicity that was over-represented. The instrument designers' proposed eight sub-scales were confirmed, which together accounted for 68.4% of the variance. All sub-scales had a Cronbach's α above the recommended minimum value of 0.7 to indicate good reliability (range: 0.72 to 0.95), except for Social function (0.66). Correlation of items within subscales was higher than correlation of items outside subscales in 90% of the cases. The overall health rating positively correlated with kidney disease-targeted scales, confirming validity. General health subscales were found to have significant associations with age, income and education, confirming convergent and divergent validity. The psychometric properties of the KDQOL-SF™ resulting from this first-time administration of the instrument support the validity and reliability of the KDQOL-SF™ as a measure of quality of life of haemodialysis patients in Singapore. It is, however, necessary to determine the test-retest reliability of the KDQOL-SF™ among the haemodialysis population of Singapore.
Assessing a Top-Down Modeling Approach for Seasonal Scale Snow Sensitivity
NASA Astrophysics Data System (ADS)
Luce, C. H.; Lute, A.
2017-12-01
Mechanistic snow models are commonly applied to assess changes to snowpacks in a warming climate. Such assessments involve a number of assumptions about details of weather at daily to sub-seasonal time scales. Models of season-scale behavior can provide contrast for evaluating behavior at time scales more in concordance with climate warming projections. Such top-down models, however, involve a degree of empiricism, with attendant caveats about the potential of a changing climate to affect calibrated relationships. We estimated the sensitivity of snowpacks from 497 Snowpack Telemetry (SNOTEL) stations in the western U.S. based on differences in climate between stations (spatial analog). We examined the sensitivity of April 1 snow water equivalent (SWE) and mean snow residence time (SRT) to variations in Nov-Mar precipitation and average Nov-Mar temperature using multivariate local-fit regressions. We tested the modeling approach using a leave-one-out cross-validation as well as targeted two-fold non-random cross-validations contrasting, for example, warm vs. cold years, dry vs. wet years, and north vs. south stations. Nash-Sutcliffe Efficiency (NSE) values for the validations were strong for April 1 SWE, ranging from 0.71 to 0.90, and still reasonable, but weaker, for SRT, in the range of 0.64 to 0.81. From these ranges, we exclude validations where the training data do not represent the range of target data. A likely reason for differences in validation between the two metrics is that the SWE model reflects the influence of conservation of mass while using temperature as an indicator of the season-scale energy balance; in contrast, SRT depends more strongly on the energy balance aspects of the problem. Model forms with lower numbers of parameters generally validated better than more complex model forms, with the caveat that pseudoreplication could encourage selection of more complex models when validation contrasts were weak. Overall, the split sample validations confirm transferability of the relationships in space and time contingent upon full representation of validation conditions in the calibration data set. The ability of the top-down space-for-time models to predict in new time periods and locations lends confidence to their application for assessments and for improving finer time scale models.
Modeling spanwise nonuniformity in the cross-sectional analysis of composite beams
NASA Astrophysics Data System (ADS)
Ho, Jimmy Cheng-Chung
Spanwise nonuniformity effects are modeled in the cross-sectional analysis of beam theory. This modeling adheres to an established numerical framework on cross-sectional analysis of uniform beams with arbitrary cross-sections. This framework is based on two concepts: decomposition of the rotation tensor and the variational-asymptotic method. Allowance of arbitrary materials and geometries in the cross-section is from discretization of the warping field by finite elements. By this approach, dimensional reduction from three-dimensional elasticity is performed rigorously and the sectional strain energy is derived to be asymptotically-correct. Elastic stiffness matrices are derived for inputs into the global beam analysis. Recovery relations for the displacement, stress, and strain fields are also derived with care to be consistent with the energy. Spanwise nonuniformity effects appear in the form of pointwise and sectionwise derivatives, which are approximated by finite differences. The formulation also accounts for the effects of spanwise variations in initial twist and/or curvature. A linearly tapered isotropic strip is analyzed to demonstrate spanwise nonuniformity effects on the cross-sectional analysis. The analysis is performed analytically by the variational-asymptotic method. Results from beam theory are validated against solutions from plane stress elasticity. These results demonstrate that spanwise nonuniformity effects become significant as the rate at which the cross-sections vary increases. The modeling of transverse shear modes of deformation is accomplished by transforming the strain energy into generalized Timoshenko form. Approximations in this transformation procedure from previous works, when applied to uniform beams, are identified. The approximations are not used in the present work so as to retain more accuracy. Comparison of present results with those previously published shows that these approximations sometimes change the results measurably and thus are inappropriate. Static and dynamic results, from the global beam analysis, are calculated to show the differences between using stiffness constants from previous works and the present work. As a form of validation of the transformation procedure, calculations from the global beam analysis of initially twisted isotropic beams from using curvilinear coordinate axes featuring twist are shown to be equivalent to calculations using Cartesian coordinates.
Pat, Lucio; Ali, Bassam; Guerrero, Armando; Córdova, Atl V.; Garduza, José P.
2016-01-01
Attenuated total reflectance-Fourier transform infrared spectrometry and chemometrics model was used for determination of physicochemical properties (pH, redox potential, free acidity, electrical conductivity, moisture, total soluble solids (TSS), ash, and HMF) in honey samples. The reference values of 189 honey samples of different botanical origin were determined using Association Official Analytical Chemists, (AOAC), 1990; Codex Alimentarius, 2001, International Honey Commission, 2002, methods. Multivariate calibration models were built using partial least squares (PLS) for the measurands studied. The developed models were validated using cross-validation and external validation; several statistical parameters were obtained to determine the robustness of the calibration models: (PCs) optimum number of components principal, (SECV) standard error of cross-validation, (R 2 cal) coefficient of determination of cross-validation, (SEP) standard error of validation, and (R 2 val) coefficient of determination for external validation and coefficient of variation (CV). The prediction accuracy for pH, redox potential, electrical conductivity, moisture, TSS, and ash was good, while for free acidity and HMF it was poor. The results demonstrate that attenuated total reflectance-Fourier transform infrared spectrometry is a valuable, rapid, and nondestructive tool for the quantification of physicochemical properties of honey. PMID:28070445
Puhan, Milo A; Gaspoz, Jean-Michel; Bridevaux, Pierre-Olivier; Schindler, Christian; Ackermann-Liebrich, Ursula; Rochat, Thierry; Gerbase, Margaret W
2008-02-15
Few epidemiologic studies have assessed health-related quality of life (HRQL) of asthma patients from a general population and it is unclear which instrument is best suitable for this purpose. We investigated the validity of the Asthma Quality of Life Questionnaire (AQLQ) and the SF-36 completed by individuals with asthma from the population-based SAPALDIA (Swiss study on air pollution and lung diseases in adults) cohort. The study included 258 participants with a physician-diagnosed asthma who had completed the AQLQ and SF-36. We assessed floor and ceiling effects, internal consistency reliability and cross-sectional validity with a priori hypotheses that correlations between the specific HRQL domains (e.g. "symptoms" or "physical functioning") and the corresponding external validation measures (respiratory symptoms, need for doctor visits, limitation in activities due to asthma and lung function) would capture similar aspects and be correlated moderately (> or = 0.3) to strongly (> or = 0.5), whereas non-corresponding domains be correlated weakly with each other (<0.3). The AQLQ showed pronounced ceiling effects with all median domain scores above 6 (scores varied from 1-7). For the SF-36, ceiling effects were present in 5 out of 8 domains. Cronbach's alpha was >0.7 for all AQLQ and SF-36 domains. Correlations between the AQLQ domains "respiratory symptoms", "activity limitation" and "environmental exposure", and the validation measures ranged from 0.29-0.57. Correlations between the "emotional function" domain and the validation measures were also in this range (0.31-0.55) and not as low as we hypothesized. For the SF-36, correlations between "physical functioning" and "role physical", and the validation measures ranged from 0.25-0.56, whereas "role emotional" and "mental health" correlated with these measures from 0.01-0.23. The AQLQ and the SF-36 showed fairly good internal consistency. Both instruments are limited by ceiling effects, but they appear less pronounced in the SF-36, which also shows a better discrimination between different aspects of HRQL. The SF-36 may therefore be a more valid measure of HRQL than the AQLQ when applied to individuals with asthma from the general population.
Determining the properties of accretion-gap neutron stars
NASA Technical Reports Server (NTRS)
Kluzniak, Wlodzimierz; Michelson, Peter; Wagoner, Robert V.
1990-01-01
If neutron stars have radii as small as has been argued by some, observations of accretion-powered X-rays could verify the existence of innermost stable circular orbits (predicted by general relativity) around weakly magnetized neutron stars. This may be done by detecting X-ray emission from clumps of matter before and after they cross the gap (where matter cannot be supported by rotation) between the inner accretion disk and the stellar surface. Assuming the validity of general relativity, it would then be possible to determine the masses of such neutron stars independently of any knowledge of binary orbital parameters. If an accurate mass determination were already available through any of the methods conventionally used, the new mass determination method proposed here could then be used to quantitatively test strong field effects of gravitational theory.
Airola, Antti; Pyysalo, Sampo; Björne, Jari; Pahikkala, Tapio; Ginter, Filip; Salakoski, Tapio
2008-11-19
Automated extraction of protein-protein interactions (PPI) is an important and widely studied task in biomedical text mining. We propose a graph kernel based approach for this task. In contrast to earlier approaches to PPI extraction, the introduced all-paths graph kernel has the capability to make use of full, general dependency graphs representing the sentence structure. We evaluate the proposed method on five publicly available PPI corpora, providing the most comprehensive evaluation done for a machine learning based PPI-extraction system. We additionally perform a detailed evaluation of the effects of training and testing on different resources, providing insight into the challenges involved in applying a system beyond the data it was trained on. Our method is shown to achieve state-of-the-art performance with respect to comparable evaluations, with 56.4 F-score and 84.8 AUC on the AImed corpus. We show that the graph kernel approach performs on state-of-the-art level in PPI extraction, and note the possible extension to the task of extracting complex interactions. Cross-corpus results provide further insight into how the learning generalizes beyond individual corpora. Further, we identify several pitfalls that can make evaluations of PPI-extraction systems incomparable, or even invalid. These include incorrect cross-validation strategies and problems related to comparing F-score results achieved on different evaluation resources. Recommendations for avoiding these pitfalls are provided.
De Smedt, Delphine; Clays, Els; Doyle, Frank; Kotseva, Kornelia; Prugger, Christof; Pająk, Andrzej; Jennings, Catriona; Wood, David; De Bacquer, Dirk
2013-09-01
To investigate the validity and reliability of the EuroQol-5D (EQ-5D), the 12-item Short-Form Health Survey (SF-12v2), and the Hospital Anxiety and Depression Scale (HADS) in a stable coronary population. Cross-sectional study EUROASPIRE III. Quality of life data (QoL) were available on 8745 patients hospitalized for coronary artery bypass graft (CABG), percutaneous coronary intervention (PCI), acute myocardial infarction (AMI), or myocardial ischemia. They were interviewed and examined at least 6 months after their hospital admission. Reliability and validity of the 3 instruments were tested. Internal consistency, and discriminative, convergent, criterion and construct validity were assessed. Cronbach's alpha indicated good internal consistency for all measures (0.73 to 0.87). Discriminative validity analyses confirmed significant QoL differences between known groups: age, gender, educational level. In addition, all hypothesized correlations between QoL constructs (convergent validity) and items (criterion validity) were confirmed with significant correlations. Confirmatory factor analyses indicated good construct validity for HADS and SF-12v2. On country-specific level, results were roughly similar. The EQ-5D as well as the SF-12v2 and the HADS are reliable and valid instruments for use in a stable coronary population, both on aggregate European level and on country-specific level. However, our results must be generalized with caution, because EUROASPIRE III patients might not be representative for all patients with stable coronary heart disease. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
ERIC Educational Resources Information Center
Akinpelu, Aderonke O.; Odetunde, Marufat O.; Odole, Adesola C.
2012-01-01
Stroke-Specific Quality of Life 2.0 (SS-QoL 2.0) scale is used widely and has been cross-culturally adapted to many languages. This study aimed at the cross-cultural adaptation of SS-QoL 2.0 to Yoruba, the indigenous language of south-western Nigeria, and to carry out an initial investigation on its validity. English SS-QoL 2.0 was first adapted…
Kliem, Sören; Lohmann, Anna; Mößle, Thomas; Brähler, Elmar
2017-12-04
Suicidal ideation has been identified as one of the major predictors of attempted or actual suicide. Routinely screening individuals for endorsing suicidal thoughts could save lives and protect many from severe psychological consequences following the suicide of loved ones. The aim of this study was to validate the German version of the Beck Scale for Suicide Ideation (BSS) in a sample representative for the Federal Republic of Germany. All 2450 participants completed the first part of the Scale, the BSS-Screen. A risk group of n = 112 individuals (4.6%) with active or passive suicidal ideation was identified and subsequently completed the entire BSS. Satisfactory internal reliability (α = .97 for the BSS-Screen; α = .94 for the entire BSS) and excellent model fit indices for the one-dimensional factorial structure of the BSS-Screen (CFI = .998; TLI = .995; RMSEA = .045 [95%-CI: .030-.061]) were confirmed. Measurement invariance analyses supported strict invariance across gender, age, and depression status. We found correlations with related self-report measures in expected directions comparable to previous studies, indicating satisfactory construct validity. Our study involved cross sectional data, hence neither predictive validity nor retest-reliability were examined. As only the risk group of n = 112 individuals completed the entire measure, confirmatory factor analyses could not be conducted for the full BSS. The German translation of the BSS is a reliable and valid instrument for assessing suicidal ideation in the general population. Using it as a screening device in general and specialized medical care could substantially advance suicide prevention.
Yura, Harold T; Fields, Renny A
2011-06-20
Level crossing statistics is applied to the complex problem of atmospheric turbulence-induced beam wander for laser propagation from ground to space. A comprehensive estimate of the single-axis wander angle temporal autocorrelation function and the corresponding power spectrum is used to develop, for the first time to our knowledge, analytic expressions for the mean angular level crossing rate and the mean duration of such crossings. These results are based on an extension and generalization of a previous seminal analysis of the beam wander variance by Klyatskin and Kon. In the geometrical optics limit, we obtain an expression for the beam wander variance that is valid for both an arbitrarily shaped initial beam profile and transmitting aperture. It is shown that beam wander can disrupt bidirectional ground-to-space laser communication systems whose small apertures do not require adaptive optics to deliver uniform beams at their intended target receivers in space. The magnitude and rate of beam wander is estimated for turbulence profiles enveloping some practical laser communication deployment options and suggesting what level of beam wander effects must be mitigated to demonstrate effective bidirectional laser communication systems.
Pernambuco, Leandro; Espelt, Albert; Magalhães, Hipólito Virgílio; Lima, Kenio Costa de
2017-06-08
to present a guide with recommendations for translation, adaptation, elaboration and process of validation of tests in Speech and Language Pathology. the recommendations were based on international guidelines with a focus on the elaboration, translation, cross-cultural adaptation and validation process of tests. the recommendations were grouped into two Charts, one of them with procedures for translation and transcultural adaptation and the other for obtaining evidence of validity, reliability and measures of accuracy of the tests. a guide with norms for the organization and systematization of the process of elaboration, translation, cross-cultural adaptation and validation process of tests in Speech and Language Pathology was created.
Ni, Ming; Wong, Duo Wai-Chi; Mei, Jiong; Niu, Wenxin; Zhang, Ming
2016-09-01
The locking plate and percutaneous crossing metallic screws and crossing absorbable screws have been used clinically to treat intra-articular calcaneal fractures, but little is known about the biomechanical differences between them. This study compared the biomechanical stability of calcaneal fractures fixed using a locking plate and crossing screws. Three-dimensional finite-element models of intact and fractured calcanei were developed based on the CT images of a cadaveric sample. Surgeries were simulated on models of Sanders type III calcaneal fractures to produce accurate postoperative models fixed by the three implants. A vertical force was applied to the superior surface of the subtalar joint to simulate the stance phase of a walking gait. This model was validated by an in vitro experiment using the same calcaneal sample. The intact calcaneus showed greater stiffness than the fixation models. Of the three fixations, the locking plate produced the greatest stiffness and the highest von Mises stress peak. The micromotion of the fracture fixated with the locking plate was similar to that of the fracture fixated with the metallic screws but smaller than that fixated with the absorbable screws. Fixation with both plate and crossing screws can be used to treat intra-articular calcaneal fractures. In general, fixation with crossing metallic screws is preferable because it provides sufficient stability with less stress shielding.
ERIC Educational Resources Information Center
Leong, Frederick T. L.; Austin, James T.; Sekaran, Uma; Komarraju, Meera
1998-01-01
Natives of India (n=172) completed Holland's Vocational Preference Inventory and job satisfaction measures. The inventory did not exhibit high external validity with this population. Congruence, consistency, and differentiation did not predict job or occupational satisfaction, suggesting cross-cultural limits on Holland's theory. (SK)
ERIC Educational Resources Information Center
Vlachopoulos, Symeon P.; Kaperoni, Maria; Moustaka, Frederiki C.; Anderson, Dean F.
2008-01-01
The present study reported on translating the Exercise Identity Scale (EIS: Anderson & Cychosz, 1994) into Greek and examining its psychometric properties and cross-cultural validity based on U.S. individuals' EIS responses. Using four samples comprising 33, 103, and 647 Greek individuals, including exercisers and nonexercisers, and a similar…
Cross-Validation of FITNESSGRAM® Health-Related Fitness Standards in Hungarian Youth
ERIC Educational Resources Information Center
Laurson, Kelly R.; Saint-Maurice, Pedro F.; Karsai, István; Csányi, Tamás
2015-01-01
Purpose: The purpose of this study was to cross-validate FITNESSGRAM® aerobic and body composition standards in a representative sample of Hungarian youth. Method: A nationally representative sample (N = 405) of Hungarian adolescents from the Hungarian National Youth Fitness Study (ages 12-18.9 years) participated in an aerobic capacity assessment…
ERIC Educational Resources Information Center
Virues-Ortega, Javier; Segui-Duran, David; Descalzo-Quero, Alberto; Carnerero, Jose Julio; Martin, Neil
2011-01-01
The Motivation Assessment Scale is an aid for hypothesis-driven functional analysis. This study presents its Spanish cross-cultural validation while examining psychometric attributes not yet explored. The study sample comprised 80 primary caregivers of children with autism. Acceptability, scaling assumptions, internal consistency, factor…
Cross-Cultural Validation of the Counselor Burnout Inventory in Hong Kong
ERIC Educational Resources Information Center
Shin, Hyojung; Yuen, Mantak; Lee, Jayoung; Lee, Sang Min
2013-01-01
This study investigated the cross-cultural validation of the Chinese translation of the Counselor Burnout Inventory (CBI) with a sample of school counselors in Hong Kong. Specifically, this study examined the CBI's factor structure using confirmatory factor analysis and calculated the effect size, to compare burnout scores among the counselors of…
Cross-Validation of a Short Form of the Marlowe-Crowne Social Desirability Scale.
ERIC Educational Resources Information Center
Zook, Avery, II; Sipps, Gary J.
1985-01-01
Presents a cross-validation of Reynolds' short form of the Marlowe-Crowne Social Desirability Scale (N=233). Researchers administered 13 items as a separate entity, calculated Cronbach's Alpha for each sex, and computed test-retest correlation for one group. Concluded that the short form is a viable alternative. (Author/NRB)
Selection of Marine Corps Drill Instructors
1980-03-01
8 4. ., ey- Construction and Cross-Validation Statistics for Drill Instructor School Performance Success Keys...Race, and School Attrition ........... ............................. ... 15 13. Key- Construction and Cross-Validation Statistics for Drill... constructed form, the Alternation Ranking of Series Drill Instruc- tors. In this form, DIs in a Series are ranked from highest to lowest in terms of their
ERIC Educational Resources Information Center
Montirosso, Rosario; Cozzi, Patrizia; Putnam, Samuel P.; Gartstein, Maria A.; Borgatti, Renato
2011-01-01
An Italian translation of the Infant Behavior Questionnaire-Revised (IBQ-R) was developed and evaluated with 110 infants, demonstrating satisfactory internal consistency, discriminant validity, and construct validity in the form of gender and age differences, as well as factorial integrity. Cross-cultural differences were subsequently evaluated…
The Halpern Critical Thinking Assessment and Real-World Outcomes: Cross-National Applications
ERIC Educational Resources Information Center
Butler, Heather A.; Dwyer, Christopher P.; Hogan, Michael J.; Franco, Amanda; Rivas, Silvia F.; Saiz, Carlos; Almeida, Leandro S.
2012-01-01
The Halpern Critical Thinking Assessment (HCTA) is a reliable measure of critical thinking that has been validated with numerous qualitatively different samples and measures of academic success (Halpern, 2010a). This paper presents several cross-national applications of the assessment, and recent work to expand the validation of the HCTA with…
A multi-frequency iterative imaging method for discontinuous inverse medium problem
NASA Astrophysics Data System (ADS)
Zhang, Lei; Feng, Lixin
2018-06-01
The inverse medium problem with discontinuous refractive index is a kind of challenging inverse problem. We employ the primal dual theory and fast solution of integral equations, and propose a new iterative imaging method. The selection criteria of regularization parameter is given by the method of generalized cross-validation. Based on multi-frequency measurements of the scattered field, a recursive linearization algorithm has been presented with respect to the frequency from low to high. We also discuss the initial guess selection strategy by semi-analytical approaches. Numerical experiments are presented to show the effectiveness of the proposed method.
Lohse, Barbara
2015-04-01
Eating competence is an important behavioral construct, shown to be associated with healthful lifestyle practices, including dietary quality, weight management, physical activity, and sleep duration. A 16-item instrument to measure eating competence, the Satter Eating Competence Inventory was previously validated in a general sample and subsequently, a 16-item instrument was developed to address specific concerns of low-income persons; 12 items were common to both instruments. The purpose of this study was to determine if the low-income version could be applied to a general audience, simplifying intervention evaluation and facilitating cross-study comparison. Both surveys were fully completed by 127 parents (89% white; 35.8 ± 5.3 y; 86% college graduates; 51% eating competent) of preschool-age children; 96 of whom were not considered low-income. Cognitive interviews with 14 parents of varying eating competence levels clarified and confirmed findings. Scores were highly correlated (r = .98) and only 2 of the 96 were not congruently classified for eating competence. Mean difference between the two versions was .24 ± 1.55. The general audience version explained 95% of the variance in the low-income version score. Findings support the low-income version of the Satter Eating Competence Inventory for general audience use as the Satter Eating Competence Inventory 2.0. Copyright © 2014 Elsevier Ltd. All rights reserved.
Executive Function and Adaptive Behavior in Muenke Syndrome.
Yarnell, Colin M P; Addissie, Yonit A; Hadley, Donald W; Guillen Sacoto, Maria J; Agochukwu, Nneamaka B; Hart, Rachel A; Wiggs, Edythe A; Platte, Petra; Paelecke, Yvonne; Collmann, Hartmut; Schweitzer, Tilmann; Kruszka, Paul; Muenke, Maximilian
2015-08-01
To investigate executive function and adaptive behavior in individuals with Muenke syndrome using validated instruments with a normative population and unaffected siblings as controls. Participants in this cross-sectional study included individuals with Muenke syndrome (P250R mutation in FGFR3) and their mutation-negative siblings. Participants completed validated assessments of executive functioning (Behavior Rating Inventory of Executive Function [BRIEF]) and adaptive behavior skills (Adaptive Behavior Assessment System, Second Edition [ABAS-II]). Forty-four with a positive FGFR3 mutation, median age 9 years, range 7 months to 52 years were enrolled. In addition, 10 unaffected siblings served as controls (5 males, 5 females; median age, 13 years; range, 3-18 years). For the General Executive Composite scale of the BRIEF, 32.1% of the cohort had scores greater than +1.5 SD, signifying potential clinical significance. For the General Adaptive Composite of the ABAS-II, 28.2% of affected individuals scored in the 3rd-8th percentile of the normative population, and 56.4% were below the average category (<25th percentile). Multiple regression analysis did not identify craniosynostosis as a predictor of BRIEF (P = .70) or ABAS-II scores (P = .70). In the sibling pair analysis, affected siblings performed significantly poorer on the BRIEF General Executive Composite and the ABAS-II General Adaptive Composite. Individuals with Muenke syndrome are at an increased risk for developing adaptive and executive function behavioral changes compared with a normative population and unaffected siblings. Published by Elsevier Inc.
Rogers, Elizabeth A; Yost, Kathleen J; Rosedahl, Jordan K; Linzer, Mark; Boehm, Deborah H; Thakur, Azra; Poplau, Sara; Anderson, Roger T; Eton, David T
2017-01-01
Aims To validate a comprehensive general measure of treatment burden, the Patient Experience with Treatment and Self-Management (PETS), in people with diabetes. Methods We conducted a secondary analysis of a cross-sectional survey study with 120 people diagnosed with type 1 or type 2 diabetes and at least one additional chronic illness. Surveys included established patient-reported outcome measures and a 48-item version of the PETS, a new measure comprised of multi-item scales assessing the burden of chronic illness treatment and self-care as it relates to nine domains: medical information, medications, medical appointments, monitoring health, interpersonal challenges, health care expenses, difficulty with health care services, role activity limitations, and physical/mental exhaustion from self-management. Internal reliability of PETS scales was determined using Cronbach’s alpha. Construct validity was determined through correlation of PETS scores with established measures (measures of chronic condition distress, medication satisfaction, self-efficacy, and global well-being), and known-groups validity through comparisons of PETS scores across clinically distinct groups. In an exploratory test of predictive validity, step-wise regressions were used to determine which PETS scales were most associated with outcomes of chronic condition distress, overall physical and mental health, and medication adherence. Results Respondents were 37–88 years old, 59% female, 29% non-white, and 67% college-educated. PETS scales showed good reliability (Cronbach’s alphas ≥0.74). Higher PETS scale scores (greater treatment burden) were correlated with more chronic condition distress, less medication convenience, lower self-efficacy, and worse general physical and mental health. Participants less (versus more) adherent to medications and those with more (versus fewer) health care financial difficulties had higher mean PETS scores. Medication burden was the scale that was most consistently associated with well-being and patient-reported adherence. Conclusion The PETS is a reliable and valid measure for assessing perceived treatment burden in people coping with diabetes. PMID:29184456
Rogers, Elizabeth A; Yost, Kathleen J; Rosedahl, Jordan K; Linzer, Mark; Boehm, Deborah H; Thakur, Azra; Poplau, Sara; Anderson, Roger T; Eton, David T
2017-01-01
To validate a comprehensive general measure of treatment burden, the Patient Experience with Treatment and Self-Management (PETS), in people with diabetes. We conducted a secondary analysis of a cross-sectional survey study with 120 people diagnosed with type 1 or type 2 diabetes and at least one additional chronic illness. Surveys included established patient-reported outcome measures and a 48-item version of the PETS, a new measure comprised of multi-item scales assessing the burden of chronic illness treatment and self-care as it relates to nine domains: medical information, medications, medical appointments, monitoring health, interpersonal challenges, health care expenses, difficulty with health care services, role activity limitations, and physical/mental exhaustion from self-management. Internal reliability of PETS scales was determined using Cronbach's alpha. Construct validity was determined through correlation of PETS scores with established measures (measures of chronic condition distress, medication satisfaction, self-efficacy, and global well-being), and known-groups validity through comparisons of PETS scores across clinically distinct groups. In an exploratory test of predictive validity, step-wise regressions were used to determine which PETS scales were most associated with outcomes of chronic condition distress, overall physical and mental health, and medication adherence. Respondents were 37-88 years old, 59% female, 29% non-white, and 67% college-educated. PETS scales showed good reliability (Cronbach's alphas ≥0.74). Higher PETS scale scores (greater treatment burden) were correlated with more chronic condition distress, less medication convenience, lower self-efficacy, and worse general physical and mental health. Participants less (versus more) adherent to medications and those with more (versus fewer) health care financial difficulties had higher mean PETS scores. Medication burden was the scale that was most consistently associated with well-being and patient-reported adherence. The PETS is a reliable and valid measure for assessing perceived treatment burden in people coping with diabetes.
RRegrs: an R package for computer-aided model selection with multiple regression models.
Tsiliki, Georgia; Munteanu, Cristian R; Seoane, Jose A; Fernandez-Lozano, Carlos; Sarimveis, Haralambos; Willighagen, Egon L
2015-01-01
Predictive regression models can be created with many different modelling approaches. Choices need to be made for data set splitting, cross-validation methods, specific regression parameters and best model criteria, as they all affect the accuracy and efficiency of the produced predictive models, and therefore, raising model reproducibility and comparison issues. Cheminformatics and bioinformatics are extensively using predictive modelling and exhibit a need for standardization of these methodologies in order to assist model selection and speed up the process of predictive model development. A tool accessible to all users, irrespectively of their statistical knowledge, would be valuable if it tests several simple and complex regression models and validation schemes, produce unified reports, and offer the option to be integrated into more extensive studies. Additionally, such methodology should be implemented as a free programming package, in order to be continuously adapted and redistributed by others. We propose an integrated framework for creating multiple regression models, called RRegrs. The tool offers the option of ten simple and complex regression methods combined with repeated 10-fold and leave-one-out cross-validation. Methods include Multiple Linear regression, Generalized Linear Model with Stepwise Feature Selection, Partial Least Squares regression, Lasso regression, and Support Vector Machines Recursive Feature Elimination. The new framework is an automated fully validated procedure which produces standardized reports to quickly oversee the impact of choices in modelling algorithms and assess the model and cross-validation results. The methodology was implemented as an open source R package, available at https://www.github.com/enanomapper/RRegrs, by reusing and extending on the caret package. The universality of the new methodology is demonstrated using five standard data sets from different scientific fields. Its efficiency in cheminformatics and QSAR modelling is shown with three use cases: proteomics data for surface-modified gold nanoparticles, nano-metal oxides descriptor data, and molecular descriptors for acute aquatic toxicity data. The results show that for all data sets RRegrs reports models with equal or better performance for both training and test sets than those reported in the original publications. Its good performance as well as its adaptability in terms of parameter optimization could make RRegrs a popular framework to assist the initial exploration of predictive models, and with that, the design of more comprehensive in silico screening applications.Graphical abstractRRegrs is a computer-aided model selection framework for R multiple regression models; this is a fully validated procedure with application to QSAR modelling.
2011-01-01
Background Health-related quality of life (HRQoL) assessment, encompassing the adolescents' perceptions of their mental, physical, and social health and well-being is increasingly considered an important outcome to be used to identify population health needs and to provide targeted medical care. Although validated instruments are essential for accurately assessing HRQoL outcomes, there are few cross-culturally adapted tools for use in Brazil, and none designed exclusively for use among adolescents. The Vécu et Santé Perçue de l'Adolescent (VSP-A) is a generic, multidimensional self-reported instrument originally developed and validated in France that evaluates HRQoL of ill and healthy adolescents. Purpose To cross-culturally adapt and validate the Brazilian-Portuguese version of the VSP-A, a generic HRQoL measure for adolescents originally developed in France. Methods The VSP-A was translated following a well-validated forward-backward process leading to the Brazilian version. The psychometric evaluation was conducted in a sample of 446 adolescents (14-18 years) attending 2 public high schools of São Gonçalo City. The adolescents self-reported the Brazilian VSP-A, the validated Psychosomatic Symptom Checklist and socio-demographic information. A retest evaluation was carried out on a sub-sample (n = 195) at a two-week interval. The internal construct validity was assessed through confirmatory factor analysis (CFA), multi-trait scaling analyses, Rasch analysis evaluating unidimensionality of each scale and Cronbach's alpha coefficients. The reproducibility was evaluated by intra-class correlation coefficients (ICC). Zumbo's ordinal logistic regression analysis was used to detect differential item functioning (DIF) between the Brazilian and the French items. External construct validity was investigated testing expected differences between groups using one-way analysis of variance (ANOVA), Mann-Whitney tests and the univariate general regression linear model. Results CFA showed an acceptable fit (RMSEA=0.05; CFI=0.93); 94% of scaling success was found for item-internal consistency and 98% for item discriminant validity. The items showed good fit to the Rasch model except 3 items with an INFIT at the upper threshold. Cronbach's Alpha ranged from 0.60 to 0.85. Test-retest reliability was moderate to good (ICC=0.55-0.82). DIF was evidenced in 4 out of 36 items. Expected patterns of differences were confirmed with significantly lower physical, psychological well being and vitality reported by symptomatic adolescents. Conclusions Although DIF in few items and responsiveness must be further explored, the Brazilian version of VSP-A demonstrated an acceptable validity and reliability in adolescents attending school and might serve as a starting point for more specific clinical investigations. PMID:21272317
How to test validity in orthodontic research: a mixed dentition analysis example.
Donatelli, Richard E; Lee, Shin-Jae
2015-02-01
The data used to test the validity of a prediction method should be different from the data used to generate the prediction model. In this study, we explored whether an independent data set is mandatory for testing the validity of a new prediction method and how validity can be tested without independent new data. Several validation methods were compared in an example using the data from a mixed dentition analysis with a regression model. The validation errors of real mixed dentition analysis data and simulation data were analyzed for increasingly large data sets. The validation results of both the real and the simulation studies demonstrated that the leave-1-out cross-validation method had the smallest errors. The largest errors occurred in the traditional simple validation method. The differences between the validation methods diminished as the sample size increased. The leave-1-out cross-validation method seems to be an optimal validation method for improving the prediction accuracy in a data set with limited sample sizes. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
Blagus, Rok; Lusa, Lara
2015-11-04
Prediction models are used in clinical research to develop rules that can be used to accurately predict the outcome of the patients based on some of their characteristics. They represent a valuable tool in the decision making process of clinicians and health policy makers, as they enable them to estimate the probability that patients have or will develop a disease, will respond to a treatment, or that their disease will recur. The interest devoted to prediction models in the biomedical community has been growing in the last few years. Often the data used to develop the prediction models are class-imbalanced as only few patients experience the event (and therefore belong to minority class). Prediction models developed using class-imbalanced data tend to achieve sub-optimal predictive accuracy in the minority class. This problem can be diminished by using sampling techniques aimed at balancing the class distribution. These techniques include under- and oversampling, where a fraction of the majority class samples are retained in the analysis or new samples from the minority class are generated. The correct assessment of how the prediction model is likely to perform on independent data is of crucial importance; in the absence of an independent data set, cross-validation is normally used. While the importance of correct cross-validation is well documented in the biomedical literature, the challenges posed by the joint use of sampling techniques and cross-validation have not been addressed. We show that care must be taken to ensure that cross-validation is performed correctly on sampled data, and that the risk of overestimating the predictive accuracy is greater when oversampling techniques are used. Examples based on the re-analysis of real datasets and simulation studies are provided. We identify some results from the biomedical literature where the incorrect cross-validation was performed, where we expect that the performance of oversampling techniques was heavily overestimated.
Lauffer, A; Solé, L; Bernstein, S; Lopes, M H; Francisconi, C F
2013-01-01
The development and validation of questionnaires for evaluating quality of life (QoL) has become an important area of research. However, there is a proliferation of non-validated measuring instruments in the health setting that do not contribute to advances in scientific knowledge. To present, through the analysis of available validated questionnaires, a checklist of the practical aspects of how to carry out the cross-cultural adaptation of QoL questionnaires (generic, or disease-specific) so that no step is overlooked in the evaluation process, and thus help prevent the elaboration of insufficient or incomplete validations. We have consulted basic textbooks and Pubmed databases using the following keywords quality of life, questionnaires, and gastroenterology, confined to «validation studies» in English, Spanish, and Portuguese, and with no time limit, for the purpose of analyzing the translation and validation of the questionnaires available through the Mapi Institute and PROQOLID websites. A checklist is presented to aid in the planning and carrying out of the cross-cultural adaptation of QoL questionnaires, in conjunction with a glossary of key terms in the area of knowledge. The acronym DSTAC was used, which refers to each of the 5 stages involved in the recommended procedure. In addition, we provide a table of the QoL instruments that have been validated into Spanish. This article provides information on how to adapt QoL questionnaires from a cross-cultural perspective, as well as to minimize common errors. Copyright © 2012 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.
Cross-cultural adaptation and validation of the neonatal/infant Braden Q risk assessment scale.
de Lima, Edson Luiz; de Brito, Maria José Azevedo; de Souza, Diba Maria Sebba Tosta; Salomé, Geraldo Magela; Ferreira, Lydia Masako
2016-02-01
To translate into Brazilian Portuguese and cross-culturally adapt the Neonatal/Infant Braden Q Risk Assessment Scale (Neonatal/Infant Braden Q Scale), and test the psychometric properties, reproducibility and validity of the instrument. There is a lack of studies on the development of pressure ulcers in children, especially in neonates. Thirty professionals participated in the cross-cultural adaptation of the Brazilian-Portuguese version of the scale. Fifty neonates of both sexes were assessed between July 2013 and June 2014. Reliability and reproducibility were tested in 20 neonates and construct validity was measured by correlating the Neonatal/Infant Braden Q Scale with the Braden Q Risk Assessment Scale (Braden Q Scale). Discriminant validity was assessed by comparing the scores of neonates with and without ulcers. The scale showed inter-rater reliability (ICC = 0.98; P < 0.001) and intra-rater reliability (ICC = 0.79; P < 0.001). A strong correlation was found between the Neonatal/Infant Braden Q Scale and Braden Q Scale (r = 0.96; P < 0.001). The cross-culturally adapted Brazilian version of the Neonatal/Infant Braden Q Scale is a reliable instrument, showing face, content and construct validity. Copyright © 2015 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.
Bayesian cross-entropy methodology for optimal design of validation experiments
NASA Astrophysics Data System (ADS)
Jiang, X.; Mahadevan, S.
2006-07-01
An important concern in the design of validation experiments is how to incorporate the mathematical model in the design in order to allow conclusive comparisons of model prediction with experimental output in model assessment. The classical experimental design methods are more suitable for phenomena discovery and may result in a subjective, expensive, time-consuming and ineffective design that may adversely impact these comparisons. In this paper, an integrated Bayesian cross-entropy methodology is proposed to perform the optimal design of validation experiments incorporating the computational model. The expected cross entropy, an information-theoretic distance between the distributions of model prediction and experimental observation, is defined as a utility function to measure the similarity of two distributions. A simulated annealing algorithm is used to find optimal values of input variables through minimizing or maximizing the expected cross entropy. The measured data after testing with the optimum input values are used to update the distribution of the experimental output using Bayes theorem. The procedure is repeated to adaptively design the required number of experiments for model assessment, each time ensuring that the experiment provides effective comparison for validation. The methodology is illustrated for the optimal design of validation experiments for a three-leg bolted joint structure and a composite helicopter rotor hub component.
Validation of tool mark analysis of cut costal cartilage.
Love, Jennifer C; Derrick, Sharon M; Wiersema, Jason M; Peters, Charles
2012-03-01
This study was designed to establish the potential error rate associated with the generally accepted method of tool mark analysis of cut marks in costal cartilage. Three knives with different blade types were used to make experimental cut marks in costal cartilage of pigs. Each cut surface was cast, and each cast was examined by three analysts working independently. The presence of striations, regularity of striations, and presence of a primary and secondary striation pattern were recorded for each cast. The distance between each striation was measured. The results showed that striations were not consistently impressed on the cut surface by the blade's cutting edge. Also, blade type classification by the presence or absence of striations led to a 65% misclassification rate. Use of the classification tree and cross-validation methods and inclusion of the mean interstriation distance decreased the error rate to c. 50%. © 2011 American Academy of Forensic Sciences.
Measurement Scales of Suicidal Ideation and Attitudes: A Systematic Review Article
Ghasemi, Parvin; Shaghaghi, Abdolreza; Allahverdipour, Hamid
2015-01-01
Background: The main aim of this study was to accumulate research evidence that introduce validated scales to measure suicidal attitudes and ideation and provide an empirical framework for adopting a relevant assessment tool in studies on suicide and suicidal behaviors. Methods: Medical Subject Headings’ (MeSH) terms were used to search Ovid Medline, PROQUEST, Wiley online library, Science Direct and PubMed for the published articles in English that reported application of an scale to measure suicidal attitudes and ideation from January 1974 onward. Results: Fourteen suicidal attitude scale and 15 scales for assessing suicidal ideation were identified in this systematic review. No gold standard approach was recognized to study suicide related attitudes and ideations. Conclusion: Special focus on generally agreed dimensions of suicidal ideation and attitudes and cross-cultural validation of the introduced scales to be applicable in different ethnic and socially diverse populations could be a promising area of research for scholars. PMID:26634193
Avelino, Patrick Roberto; Magalhães, Lívia Castro; Faria-Fortini, Iza; Basílio, Marluce Lopes; Menezes, Kênia Kiefer Parreiras; Teixeira-Salmela, Luci Fuscaldi
2018-06-01
The purpose of this study was to evaluate the cross-cultural validity of the Brazilian version of the ABILOCO questionnaire for stroke subjects. Cross-cultural adaptation of the original English version of the ABILOCO to the Brazilian-Portuguese language followed standardized procedures. The adapted version was administered to 136 stroke subjects and its measurement properties were assessed using Rash analysis. Cross-cultural validity was based on cultural invariance analyses. Goodness-of-fit analysis revealed one misfitting item. The principal component analysis of the residuals showed that the first dimension explained 45% of the variance in locomotion ability; however, the eigenvalue was 1.92. The ABILOCO-Brazil divided the sample into two levels of ability and the items into about seven levels of difficulty. The item-person map showed some ceiling effect. Cultural invariance analyses revealed that although there were differences in the item calibrations between the ABILOCO-original and ABILOCO-Brazil, they did not impact the measures of locomotion ability. The ABILOCO-Brazil demonstrated satisfactory measurement properties to be used within both clinical and research contexts in Brazil, as well cross-cultural validity to be used in international/multicentric studies. However, the presence of ceiling effect suggests that it may not be appropriate for the assessment of individuals with high levels of locomotion ability. Implications for rehabilitation Self-report measures of locomotion ability are clinically important, since they describe the abilities of the individuals within real life contexts. The ABILOCO questionnaire, specific for stroke survivors, demonstrated satisfactory measurement properties, but may not be most appropriate to assess individuals with high levels of locomotion ability The results of the cross-cultural validity showed that the ABILOCO-Original and the ABILOCO-Brazil calibrations may be used interchangeable.
Complex Environmental Data Modelling Using Adaptive General Regression Neural Networks
NASA Astrophysics Data System (ADS)
Kanevski, Mikhail
2015-04-01
The research deals with an adaptation and application of Adaptive General Regression Neural Networks (GRNN) to high dimensional environmental data. GRNN [1,2,3] are efficient modelling tools both for spatial and temporal data and are based on nonparametric kernel methods closely related to classical Nadaraya-Watson estimator. Adaptive GRNN, using anisotropic kernels, can be also applied for features selection tasks when working with high dimensional data [1,3]. In the present research Adaptive GRNN are used to study geospatial data predictability and relevant feature selection using both simulated and real data case studies. The original raw data were either three dimensional monthly precipitation data or monthly wind speeds embedded into 13 dimensional space constructed by geographical coordinates and geo-features calculated from digital elevation model. GRNN were applied in two different ways: 1) adaptive GRNN with the resulting list of features ordered according to their relevancy; and 2) adaptive GRNN applied to evaluate all possible models N [in case of wind fields N=(2^13 -1)=8191] and rank them according to the cross-validation error. In both cases training were carried out applying leave-one-out procedure. An important result of the study is that the set of the most relevant features depends on the month (strong seasonal effect) and year. The predictabilities of precipitation and wind field patterns, estimated using the cross-validation and testing errors of raw and shuffled data, were studied in detail. The results of both approaches were qualitatively and quantitatively compared. In conclusion, Adaptive GRNN with their ability to select features and efficient modelling of complex high dimensional data can be widely used in automatic/on-line mapping and as an integrated part of environmental decision support systems. 1. Kanevski M., Pozdnoukhov A., Timonin V. Machine Learning for Spatial Environmental Data. Theory, applications and software. EPFL Press. With a CD: data, software, guides. (2009). 2. Kanevski M. Spatial Predictions of Soil Contamination Using General Regression Neural Networks. Systems Research and Information Systems, Volume 8, number 4, 1999. 3. Robert S., Foresti L., Kanevski M. Spatial prediction of monthly wind speeds in complex terrain with adaptive general regression neural networks. International Journal of Climatology, 33 pp. 1793-1804, 2013.
Baek, Sora; Park, Hee-Won; Lee, Yookyung; Grace, Sherry L; Kim, Won-Seok
2017-10-01
To perform a translation and cross-cultural adaptation of the Cardiac Rehabilitation Barriers Scale (CRBS) for use in Korea, followed by psychometric validation. The CRBS was developed to assess patients' perception of the degree to which patient, provider and health system-level barriers affect their cardiac rehabilitation (CR) participation. The CRBS consists of 21 items (barriers to adherence) rated on a 5-point Likert scale. The first phase was to translate and cross-culturally adapt the CRBS to the Korean language. After back-translation, both versions were reviewed by a committee. The face validity was assessed in a sample of Korean patients (n=53) with history of acute myocardial infarction that did not participate in CR through semi-structured interviews. The second phase was to assess the construct and criterion validity of the Korean translation as well as internal reliability, through administration of the translated version in 104 patients, principle component analysis with varimax rotation and cross-referencing against CR use, respectively. The length, readability, and clarity of the questionnaire were rated well, demonstrating face validity. Analysis revealed a six-factor solution, demonstrating construct validity. Cronbach's alpha was greater than 0.65. Barriers rated highest included not knowing about CR and not being contacted by a program. The mean CRBS score was significantly higher among non-attendees (2.71±0.26) than CR attendees (2.51±0.18) (p<0.01). The Korean version of CRBS has demonstrated face, content and criterion validity, suggesting it may be useful for assessing barriers to CR utilization in Korea.
PCA as a practical indicator of OPLS-DA model reliability.
Worley, Bradley; Powers, Robert
Principal Component Analysis (PCA) and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) are powerful statistical modeling tools that provide insights into separations between experimental groups based on high-dimensional spectral measurements from NMR, MS or other analytical instrumentation. However, when used without validation, these tools may lead investigators to statistically unreliable conclusions. This danger is especially real for Partial Least Squares (PLS) and OPLS, which aggressively force separations between experimental groups. As a result, OPLS-DA is often used as an alternative method when PCA fails to expose group separation, but this practice is highly dangerous. Without rigorous validation, OPLS-DA can easily yield statistically unreliable group separation. A Monte Carlo analysis of PCA group separations and OPLS-DA cross-validation metrics was performed on NMR datasets with statistically significant separations in scores-space. A linearly increasing amount of Gaussian noise was added to each data matrix followed by the construction and validation of PCA and OPLS-DA models. With increasing added noise, the PCA scores-space distance between groups rapidly decreased and the OPLS-DA cross-validation statistics simultaneously deteriorated. A decrease in correlation between the estimated loadings (added noise) and the true (original) loadings was also observed. While the validity of the OPLS-DA model diminished with increasing added noise, the group separation in scores-space remained basically unaffected. Supported by the results of Monte Carlo analyses of PCA group separations and OPLS-DA cross-validation metrics, we provide practical guidelines and cross-validatory recommendations for reliable inference from PCA and OPLS-DA models.
Cross-Layer Design for Space-Time coded MIMO Systems over Rice Fading Channel
NASA Astrophysics Data System (ADS)
Yu, Xiangbin; Zhou, Tingting; Liu, Xiaoshuai; Yin, Xin
A cross-layer design (CLD) scheme for space-time coded MIMO systems over Rice fading channel is presented by combining adaptive modulation and automatic repeat request, and the corresponding system performance is investigated well. The fading gain switching thresholds subject to a target packet error rate (PER) and fixed power constraint are derived. According to these results, and using the generalized Marcum Q-function, the calculation formulae of the average spectrum efficiency (SE) and PER of the system with CLD are derived. As a result, closed-form expressions for average SE and PER are obtained. These expressions include some existing expressions in Rayleigh channel as special cases. With these expressions, the system performance in Rice fading channel is evaluated effectively. Numerical results verify the validity of the theoretical analysis. The results show that the system performance in Rice channel is effectively improved as Rice factor increases, and outperforms that in Rayleigh channel.
The HITRAN2016 molecular spectroscopic database
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gordon, I. E.; Rothman, L. S.; Hill, C.
This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is comprised of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additionalmore » absorption phenomena, added line-shape formalisms, and validity. Moreover, molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth. Of considerable note, experimental IR cross-sections for almost 200 additional significant molecules have been added to the database.« less
The reliability and validity of the SF-8 with a conflict-affected population in northern Uganda.
Roberts, Bayard; Browne, John; Ocaka, Kaducu Felix; Oyok, Thomas; Sondorp, Egbert
2008-12-02
The SF-8 is a health-related quality of life instrument that could provide a useful means of assessing general physical and mental health amongst populations affected by conflict. The purpose of this study was to test the validity and reliability of the SF-8 with a conflict-affected population in northern Uganda. A cross-sectional multi-staged, random cluster survey was conducted with 1206 adults in camps for internally displaced persons in Gulu and Amuru districts of northern Uganda. Data quality was assessed by analysing the number of incomplete responses to SF-8 items. Response distribution was analysed using aggregate endorsement frequency. Test-retest reliability was assessed in a separate smaller survey using the intraclass correlation test. Construct validity was measured using principal component analysis, and the Pearson Correlation test for item-summary score correlation and inter-instrument correlations. Known groups validity was assessed using a two sample t-test to evaluates the ability of the SF-8 to discriminate between groups known to have, and not have, physical and mental health problems. The SF-8 showed excellent data quality. It showed acceptable item response distribution based upon analysis of aggregate endorsement frequencies. Test-retest showed a good intraclass correlation of 0.61 for PCS and 0.68 for MCS. The principal component analysis indicated strong construct validity and concurred with the results of the validity tests by the SF-8 developers. The SF-8 also showed strong construct validity between the 8 items and PCS and MCS summary score, moderate inter-instrument validity, and strong known groups validity. This study provides evidence on the reliability and validity of the SF-8 amongst IDPs in northern Uganda.
The reliability and validity of the SF-8 with a conflict-affected population in northern Uganda
Roberts, Bayard; Browne, John; Ocaka, Kaducu Felix; Oyok, Thomas; Sondorp, Egbert
2008-01-01
Background The SF-8 is a health-related quality of life instrument that could provide a useful means of assessing general physical and mental health amongst populations affected by conflict. The purpose of this study was to test the validity and reliability of the SF-8 with a conflict-affected population in northern Uganda. Methods A cross-sectional multi-staged, random cluster survey was conducted with 1206 adults in camps for internally displaced persons in Gulu and Amuru districts of northern Uganda. Data quality was assessed by analysing the number of incomplete responses to SF-8 items. Response distribution was analysed using aggregate endorsement frequency. Test-retest reliability was assessed in a separate smaller survey using the intraclass correlation test. Construct validity was measured using principal component analysis, and the Pearson Correlation test for item-summary score correlation and inter-instrument correlations. Known groups validity was assessed using a two sample t-test to evaluates the ability of the SF-8 to discriminate between groups known to have, and not have, physical and mental health problems. Results The SF-8 showed excellent data quality. It showed acceptable item response distribution based upon analysis of aggregate endorsement frequencies. Test-retest showed a good intraclass correlation of 0.61 for PCS and 0.68 for MCS. The principal component analysis indicated strong construct validity and concurred with the results of the validity tests by the SF-8 developers. The SF-8 also showed strong construct validity between the 8 items and PCS and MCS summary score, moderate inter-instrument validity, and strong known groups validity. Conclusion This study provides evidence on the reliability and validity of the SF-8 amongst IDPs in northern Uganda. PMID:19055716
Moreno-Rosset, Carmen; Antequera Jurado, Rosario; Jenaro Río, Cristina
2009-02-01
Validation of the Questionnaire of Emotional Maladjustment and Adaptive Resources in Infertility (DERA). Given the absence of measures to help psychologists working with infertile couples, this paper presents the process of developing a standardized measure to assess emotional maladjustment and adaptive resources in this population. A cross-sectional design was utilized to gather data from the assisted reproduction units of two public hospitals. Preliminary analyses were performed with a sample of 85 infertile patients. Psychometric properties of the measure were tested with a second sample of 490 infertile patients. Concerning reliability analyses, alpha indexes were adequate both for the measure and its factors. Concerning validity, second-order factor analysis yielded a four-factor solution that conjointly explains 56% of the total variance. Additional analyses with a third sample of 50 participants from the general population matched with a sample of 50 infertile participants were performed. In sum, this measure seems to be a useful psychological assessment tool to determine emotional adjustment, and individual, and interpersonal resources, for coping with infertility diagnosis and treatment.
Sexual Orientation Self-Concept Ambiguity: Scale Adaptation and Validation.
Talley, Amelia E; Stevens, Jordan E
2017-07-01
The current article describes the adaptation of a measure of sexual orientation self-concept ambiguity (SSA) from an existing measure of general self-concept clarity. Latent "trait" scores of SSA reflect the extent to which a person's beliefs about their own sexual orientation are perceived as inconsistent, unreliable, or incongruent. Sexual minority and heterosexual women ( n = 348), ages 18 to 30, completed a cross-sectional survey. Categorical confirmatory factor analysis guided the selection of items to form a 10-item, self-report measure of SSA. In the current report, we also examine (a) reliability of the 10-item scale score, (b) measurement invariance based on respondents' sexual identity status and age group, and (c) correlations with preexisting surveys that purport to measure similar constructs and theoretical correlates. Evidence for internal reliability, measurement invariance (based on respondent sex), and convergent validity was also investigated in an independent, validation sample. The lowest SSA scores were reported by women who self-ascribed an exclusively heterosexual or exclusively lesbian/gay sexual identity, whereas those who reported a bisexual, mostly lesbian/gay, or mostly heterosexual identity, reported relatively higher SSA scores.
Assessment of Magical Beliefs about Food and Health.
Lindeman, M; Keskivaara, P; Roschier, M
2000-03-01
The Magical Beliefs About Food and Health scale (MFH) was developed to assess individual differences in the tendency to adopt eating and health instructions that many magazines, health care books and food ideologies regard as valid but which obey universal laws of similarity and contagion. In a study of 216 individuals, the total MFH score showed good internal consistency and it was associated with various validity criteria as hypothesized (e.g. vegetarianism and other ideological commitments to food choice, female gender, increased neuroticism, experiential thinking, positive attitudes towards alternative medicine, low sensation seeking and endorsement of universalism values). Factor analysis yielded two factors: General Magical Beliefs and Animal Products as Food Contaminants. In addition, three other items (the Animal Products as Personality Contaminants scale) cross-loaded on the two factors. The factor structure and test-retest reliability were confirmed with separate samples. The results showed that the total MFH score is a reliable and valid measure of magical food and health beliefs, and that the subscales may prove useful when a multidimensional assessment of magical beliefs is needed.
Dyadic Short Forms of the Wechsler Adult Intelligence Scale-IV.
Denney, David A; Ringe, Wendy K; Lacritz, Laura H
2015-08-01
Full Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) administration can be time-consuming and may not be necessary when intelligence quotient estimates will suffice. Estimated Full Scale Intelligence Quotient (FSIQ) and General Ability Index (GAI) scores were derived from nine dyadic short forms using individual regression equations based on data from a clinical sample (n = 113) that was then cross validated in a separate clinical sample (n = 50). Derived scores accounted for 70%-83% of the variance in FSIQ and 77%-88% of the variance in GAI. Predicted FSIQs were strongly associated with actual FSIQ (rs = .73-.88), as were predicted and actual GAIs (rs = .80-.93). Each of the nine dyadic short forms of the WAIS-IV was a good predictor of FSIQ and GAI in the validation sample. These data support the validity of WAIS-IV short forms when time is limited or lengthier batteries cannot be tolerated by patients. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Cross-cultural adaptation and validation to Brazil of the Obesity-related Problems Scale
Brasil, Andreia Mara Brolezzi; Brasil, Fábio; Maurício, Angélica Aparecida; Vilela, Regina Maria
2017-01-01
ABSTRACT Objective To validate a reliable version of the Obesity-related Problems Scale in Portuguese to use it in Brazil. Methods The Obesity-related Problems Scale was translated and transculturally adapted. Later it was simultaneously self-applied with a 12-item version of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), to 50 obese patients and 50 non-obese individuals, and applied again to half of them after 14 days. Results The Obesity-related Problems scale was able to differentiate obese from non-obese individuals with higher accuracy than WHODAS 2.0, correlating with this scale and with body mass index. The factor analysis determined a two-dimensional structure, which was confirmed with χ2/df=1.81, SRMR=0.05, and CFI=0.97. The general a coefficient was 0.90 and the inter-item intra-class correlation, in the reapplication, ranged from 0.75 to 0.87. Conclusion The scale proved to be valid and reliable for use in the Brazilian population, without the need to exclude items. PMID:29091155
Cross-cultural French adaptation and validation of the Impact On Family Scale (IOFS).
Boudas, Raphaël; Jégu, Jérémie; Grollemund, Bruno; Quentel, Elvire; Danion-Grilliat, Anne; Velten, Michel
2013-04-23
The IOFS (Impact On Family Scale) questionnaire is a useful instrument to assess the impact of chronic childhood conditions on general family quality of life. As this instrument was not validated in French, we proposed to translate, adapt and validate the IOFS questionnaire for clinical and research use in French-speaking populations. The sample studied comprised French-speaking parents with a child presenting a cleft lip or cleft lip and palate, aged 6 to 12 years and treated in the University Hospital of Strasbourg, France. The 15-item version of the IOFS was translated into French and then sent to the parents by post. The structure of the measure was studied using Exploratory Factor Analysis (EFA), internal consistency was assessed using Cronbach's alpha coefficient and test-retest reliability was studied by calculating the Intraclass Correlation Coefficient (ICC). The French version of the IOFS questionnaire exhibited very good psychometric properties. For practitioners, this instrument will facilitate the assessment of the impact of chronic childhood conditions on quality of life among French-speaking families.
NASA Astrophysics Data System (ADS)
Nlandu Kamavuako, Ernest; Scheme, Erik Justin; Englehart, Kevin Brian
2016-08-01
Objective. For over two decades, Hudgins’ set of time domain features have extensively been applied for classification of hand motions. The calculation of slope sign change and zero crossing features uses a threshold to attenuate the effect of background noise. However, there is no consensus on the optimum threshold value. In this study, we investigate for the first time the effect of threshold selection on the feature space and classification accuracy using multiple datasets. Approach. In the first part, four datasets were used, and classification error (CE), separability index, scatter matrix separability criterion, and cardinality of the features were used as performance measures. In the second part, data from eight classes were collected during two separate days with two days in between from eight able-bodied subjects. The threshold for each feature was computed as a factor (R = 0:0.01:4) times the average root mean square of data during rest. For each day, we quantified CE for R = 0 (CEr0) and minimum error (CEbest). Moreover, a cross day threshold validation was applied where, for example, CE of day two (CEodt) is computed based on optimum threshold from day one and vice versa. Finally, we quantified the effect of the threshold when using training data from one day and test data of the other. Main results. All performance metrics generally degraded with increasing threshold values. On average, CEbest (5.26 ± 2.42%) was significantly better than CEr0 (7.51 ± 2.41%, P = 0.018), and CEodt (7.50 ± 2.50%, P = 0.021). During the two-fold validation between days, CEbest performed similar to CEr0. Interestingly, when using the threshold values optimized per subject from day one and day two respectively, on the cross-days classification, the performance decreased. Significance. We have demonstrated that threshold value has a strong impact on the feature space and that an optimum threshold can be quantified. However, this optimum threshold is highly data and subject driven and thus do not generalize well. There is a strong evidence that R = 0 provides a good trade-off between system performance and generalization. These findings are important for practical use of pattern recognition based myoelectric control.
Kamavuako, Ernest Nlandu; Scheme, Erik Justin; Englehart, Kevin Brian
2016-08-01
For over two decades, Hudgins' set of time domain features have extensively been applied for classification of hand motions. The calculation of slope sign change and zero crossing features uses a threshold to attenuate the effect of background noise. However, there is no consensus on the optimum threshold value. In this study, we investigate for the first time the effect of threshold selection on the feature space and classification accuracy using multiple datasets. In the first part, four datasets were used, and classification error (CE), separability index, scatter matrix separability criterion, and cardinality of the features were used as performance measures. In the second part, data from eight classes were collected during two separate days with two days in between from eight able-bodied subjects. The threshold for each feature was computed as a factor (R = 0:0.01:4) times the average root mean square of data during rest. For each day, we quantified CE for R = 0 (CEr0) and minimum error (CEbest). Moreover, a cross day threshold validation was applied where, for example, CE of day two (CEodt) is computed based on optimum threshold from day one and vice versa. Finally, we quantified the effect of the threshold when using training data from one day and test data of the other. All performance metrics generally degraded with increasing threshold values. On average, CEbest (5.26 ± 2.42%) was significantly better than CEr0 (7.51 ± 2.41%, P = 0.018), and CEodt (7.50 ± 2.50%, P = 0.021). During the two-fold validation between days, CEbest performed similar to CEr0. Interestingly, when using the threshold values optimized per subject from day one and day two respectively, on the cross-days classification, the performance decreased. We have demonstrated that threshold value has a strong impact on the feature space and that an optimum threshold can be quantified. However, this optimum threshold is highly data and subject driven and thus do not generalize well. There is a strong evidence that R = 0 provides a good trade-off between system performance and generalization. These findings are important for practical use of pattern recognition based myoelectric control.
Penalized spline estimation for functional coefficient regression models.
Cao, Yanrong; Lin, Haiqun; Wu, Tracy Z; Yu, Yan
2010-04-01
The functional coefficient regression models assume that the regression coefficients vary with some "threshold" variable, providing appreciable flexibility in capturing the underlying dynamics in data and avoiding the so-called "curse of dimensionality" in multivariate nonparametric estimation. We first investigate the estimation, inference, and forecasting for the functional coefficient regression models with dependent observations via penalized splines. The P-spline approach, as a direct ridge regression shrinkage type global smoothing method, is computationally efficient and stable. With established fixed-knot asymptotics, inference is readily available. Exact inference can be obtained for fixed smoothing parameter λ, which is most appealing for finite samples. Our penalized spline approach gives an explicit model expression, which also enables multi-step-ahead forecasting via simulations. Furthermore, we examine different methods of choosing the important smoothing parameter λ: modified multi-fold cross-validation (MCV), generalized cross-validation (GCV), and an extension of empirical bias bandwidth selection (EBBS) to P-splines. In addition, we implement smoothing parameter selection using mixed model framework through restricted maximum likelihood (REML) for P-spline functional coefficient regression models with independent observations. The P-spline approach also easily allows different smoothness for different functional coefficients, which is enabled by assigning different penalty λ accordingly. We demonstrate the proposed approach by both simulation examples and a real data application.
Computational Depth of Anesthesia via Multiple Vital Signs Based on Artificial Neural Networks.
Sadrawi, Muammar; Fan, Shou-Zen; Abbod, Maysam F; Jen, Kuo-Kuang; Shieh, Jiann-Shing
2015-01-01
This study evaluated the depth of anesthesia (DoA) index using artificial neural networks (ANN) which is performed as the modeling technique. Totally 63-patient data is addressed, for both modeling and testing of 17 and 46 patients, respectively. The empirical mode decomposition (EMD) is utilized to purify between the electroencephalography (EEG) signal and the noise. The filtered EEG signal is subsequently extracted to achieve a sample entropy index by every 5-second signal. Then, it is combined with other mean values of vital signs, that is, electromyography (EMG), heart rate (HR), pulse, systolic blood pressure (SBP), diastolic blood pressure (DBP), and signal quality index (SQI) to evaluate the DoA index as the input. The 5 doctor scores are averaged to obtain an output index. The mean absolute error (MAE) is utilized as the performance evaluation. 10-fold cross-validation is performed in order to generalize the model. The ANN model is compared with the bispectral index (BIS). The results show that the ANN is able to produce lower MAE than BIS. For the correlation coefficient, ANN also has higher value than BIS tested on the 46-patient testing data. Sensitivity analysis and cross-validation method are applied in advance. The results state that EMG has the most effecting parameter, significantly.
Computational Depth of Anesthesia via Multiple Vital Signs Based on Artificial Neural Networks
Sadrawi, Muammar; Fan, Shou-Zen; Abbod, Maysam F.; Jen, Kuo-Kuang; Shieh, Jiann-Shing
2015-01-01
This study evaluated the depth of anesthesia (DoA) index using artificial neural networks (ANN) which is performed as the modeling technique. Totally 63-patient data is addressed, for both modeling and testing of 17 and 46 patients, respectively. The empirical mode decomposition (EMD) is utilized to purify between the electroencephalography (EEG) signal and the noise. The filtered EEG signal is subsequently extracted to achieve a sample entropy index by every 5-second signal. Then, it is combined with other mean values of vital signs, that is, electromyography (EMG), heart rate (HR), pulse, systolic blood pressure (SBP), diastolic blood pressure (DBP), and signal quality index (SQI) to evaluate the DoA index as the input. The 5 doctor scores are averaged to obtain an output index. The mean absolute error (MAE) is utilized as the performance evaluation. 10-fold cross-validation is performed in order to generalize the model. The ANN model is compared with the bispectral index (BIS). The results show that the ANN is able to produce lower MAE than BIS. For the correlation coefficient, ANN also has higher value than BIS tested on the 46-patient testing data. Sensitivity analysis and cross-validation method are applied in advance. The results state that EMG has the most effecting parameter, significantly. PMID:26568957
Jun, Deokhoon; Johnston, Venerina; Kim, Jun-Mo; O'Leary, Shaun
2018-01-01
In this study, we developed a new Korean translation for the shortened version of the Depression, Anxiety, and Stress Scale (DASS-21) and examined its psychometric properties in a Korean working population. To develop a new Korean version of the DASS-21 and test its psychometric properties specific to the Korean working population. The DASS-21 was translated to the Korean language in accordance with scientific guidelines for cross-cultural adaptation. A total of 228 general workers from Korea then completed the newly translated version of the DAS S-21 and its psychometric properties were evaluated. Most of the questionnaire items were correctly loaded on the proposed scales of the original questionnaire. Excellent internal consistency and measurement consistency over a one week interval were obtained for all scales (Cronbach's alpha; 0.87, 83, and 83, and ICC (2, 1); 0.84, 0.94, and 0.89 for depression, anxiety and stress scales, respectively). All three scales were negatively associated with the level of life satisfaction (p < 0.05). The new Korean version of DASS-21 has shown excellent validity and reliability of measurement in the Korean working population. Organizations investigating the prominent health issue of affective disorders in Korean workers can use this instrument with confidence.
Mortality risk score prediction in an elderly population using machine learning.
Rose, Sherri
2013-03-01
Standard practice for prediction often relies on parametric regression methods. Interesting new methods from the machine learning literature have been introduced in epidemiologic studies, such as random forest and neural networks. However, a priori, an investigator will not know which algorithm to select and may wish to try several. Here I apply the super learner, an ensembling machine learning approach that combines multiple algorithms into a single algorithm and returns a prediction function with the best cross-validated mean squared error. Super learning is a generalization of stacking methods. I used super learning in the Study of Physical Performance and Age-Related Changes in Sonomans (SPPARCS) to predict death among 2,066 residents of Sonoma, California, aged 54 years or more during the period 1993-1999. The super learner for predicting death (risk score) improved upon all single algorithms in the collection of algorithms, although its performance was similar to that of several algorithms. Super learner outperformed the worst algorithm (neural networks) by 44% with respect to estimated cross-validated mean squared error and had an R2 value of 0.201. The improvement of super learner over random forest with respect to R2 was approximately 2-fold. Alternatives for risk score prediction include the super learner, which can provide improved performance.
A closer look at cross-validation for assessing the accuracy of gene regulatory networks and models.
Tabe-Bordbar, Shayan; Emad, Amin; Zhao, Sihai Dave; Sinha, Saurabh
2018-04-26
Cross-validation (CV) is a technique to assess the generalizability of a model to unseen data. This technique relies on assumptions that may not be satisfied when studying genomics datasets. For example, random CV (RCV) assumes that a randomly selected set of samples, the test set, well represents unseen data. This assumption doesn't hold true where samples are obtained from different experimental conditions, and the goal is to learn regulatory relationships among the genes that generalize beyond the observed conditions. In this study, we investigated how the CV procedure affects the assessment of supervised learning methods used to learn gene regulatory networks (or in other applications). We compared the performance of a regression-based method for gene expression prediction estimated using RCV with that estimated using a clustering-based CV (CCV) procedure. Our analysis illustrates that RCV can produce over-optimistic estimates of the model's generalizability compared to CCV. Next, we defined the 'distinctness' of test set from training set and showed that this measure is predictive of performance of the regression method. Finally, we introduced a simulated annealing method to construct partitions with gradually increasing distinctness and showed that performance of different gene expression prediction methods can be better evaluated using this method.
Lohrer, Heinz; Nauck, Tanja
2009-10-30
Achilles tendinopathy is the predominant overuse injury in runners. To further investigate this overload injury in transverse and longitudinal studies a valid, responsive and reliable outcome measure is demanded. Most questionnaires have been developed for English-speaking populations. This is also true for the VISA-A score, so far representing the only valid, reliable, and disease specific questionnaire for Achilles tendinopathy. To internationally compare research results, to perform multinational studies or to exclude bias originating from subpopulations speaking different languages within one country an equivalent instrument is demanded in different languages. The aim of this study was therefore to cross-cultural adapt and validate the VISA-A questionnaire for German-speaking Achilles tendinopathy patients. According to the "guidelines for the process of cross-cultural adaptation of self-report measures" the VISA-A score was cross-culturally adapted into German (VISA-A-G) using six steps: Translation, synthesis, back translation, expert committee review, pretesting (n = 77), and appraisal of the adaptation process by an advisory committee determining the adequacy of the cross-cultural adaptation. The resulting VISA-A-G was then subjected to an analysis of reliability, validity, and internal consistency in 30 Achilles tendinopathy patients and 79 asymptomatic people. Concurrent validity was tested against a generic tendon grading system (Percy and Conochie) and against a classification system for the effect of pain on athletic performance (Curwin and Stanish). The "advisory committee" determined the VISA-A-G questionnaire as been translated "acceptable". The VISA-A-G questionnaire showed moderate to excellent test-retest reliability (ICC = 0.60 to 0.97). Concurrent validity showed good coherence when correlated with the grading system of Curwin and Stanish (rho = -0.95) and for the Percy and Conochie grade of severity (rho 0.95). Internal consistency (Cronbach's alpha) for the total VISA-A-G scores of the patients was calculated to be 0.737. The VISA-A questionnaire was successfully cross-cultural adapted and validated for use in German speaking populations. The psychometric properties of the VISA-A-G questionnaire are similar to those of the original English version. It therefore can be recommended as a sufficiently robust tool for future measuring clinical severity of Achilles tendinopathy in German speaking patients.
Lohrer, Heinz; Nauck, Tanja
2009-01-01
Background Achilles tendinopathy is the predominant overuse injury in runners. To further investigate this overload injury in transverse and longitudinal studies a valid, responsive and reliable outcome measure is demanded. Most questionnaires have been developed for English-speaking populations. This is also true for the VISA-A score, so far representing the only valid, reliable, and disease specific questionnaire for Achilles tendinopathy. To internationally compare research results, to perform multinational studies or to exclude bias originating from subpopulations speaking different languages within one country an equivalent instrument is demanded in different languages. The aim of this study was therefore to cross-cultural adapt and validate the VISA-A questionnaire for German-speaking Achilles tendinopathy patients. Methods According to the "guidelines for the process of cross-cultural adaptation of self-report measures" the VISA-A score was cross-culturally adapted into German (VISA-A-G) using six steps: Translation, synthesis, back translation, expert committee review, pretesting (n = 77), and appraisal of the adaptation process by an advisory committee determining the adequacy of the cross-cultural adaptation. The resulting VISA-A-G was then subjected to an analysis of reliability, validity, and internal consistency in 30 Achilles tendinopathy patients and 79 asymptomatic people. Concurrent validity was tested against a generic tendon grading system (Percy and Conochie) and against a classification system for the effect of pain on athletic performance (Curwin and Stanish). Results The "advisory committee" determined the VISA-A-G questionnaire as been translated "acceptable". The VISA-A-G questionnaire showed moderate to excellent test-retest reliability (ICC = 0.60 to 0.97). Concurrent validity showed good coherence when correlated with the grading system of Curwin and Stanish (rho = -0.95) and for the Percy and Conochie grade of severity (rho 0.95). Internal consistency (Cronbach's alpha) for the total VISA-A-G scores of the patients was calculated to be 0.737. Conclusion The VISA-A questionnaire was successfully cross-cultural adapted and validated for use in German speaking populations. The psychometric properties of the VISA-A-G questionnaire are similar to those of the original English version. It therefore can be recommended as a sufficiently robust tool for future measuring clinical severity of Achilles tendinopathy in German speaking patients. PMID:19878572
Expanded explorations into the optimization of an energy function for protein design
Huang, Yao-ming; Bystroff, Christopher
2014-01-01
Nature possesses a secret formula for the energy as a function of the structure of a protein. In protein design, approximations are made to both the structural representation of the molecule and to the form of the energy equation, such that the existence of a general energy function for proteins is by no means guaranteed. Here we present new insights towards the application of machine learning to the problem of finding a general energy function for protein design. Machine learning requires the definition of an objective function, which carries with it the implied definition of success in protein design. We explored four functions, consisting of two functional forms, each with two criteria for success. Optimization was carried out by a Monte Carlo search through the space of all variable parameters. Cross-validation of the optimized energy function against a test set gave significantly different results depending on the choice of objective function, pointing to relative correctness of the built-in assumptions. Novel energy cross-terms correct for the observed non-additivity of energy terms and an imbalance in the distribution of predicted amino acids. This paper expands on the work presented at ACM-BCB, Orlando FL , October 2012. PMID:24384706
Measuring Adolescent Social and Academic Self-Efficacy: Cross-Ethnic Validity of the SEQ-C
ERIC Educational Resources Information Center
Minter, Anthony; Pritzker, Suzanne
2017-01-01
Objective: This study examines the psychometric strength, including cross-ethnic validity, of two subscales of Muris' Self-Efficacy Questionnaire for Children: Academic Self-Efficacy (ASE) and Social Self-Efficacy (SSE). Methods: A large ethnically diverse sample of 3,358 early and late adolescents completed surveys including the ASE and SSE.…
ERIC Educational Resources Information Center
Hilton, N. Zoe; Harris, Grant T.
2009-01-01
Prediction effect sizes such as ROC area are important for demonstrating a risk assessment's generalizability and utility. How a study defines recidivism might affect predictive accuracy. Nonrecidivism is problematic when predicting specialized violence (e.g., domestic violence). The present study cross-validates the ability of the Ontario…
USDA-ARS?s Scientific Manuscript database
Generalised skinfold equations developed in the 1970s are commonly used to estimate laboratory-measured percentage fat (BF%). The equations were developed on predominately white individuals using Siri's two-component percentage fat equation (BF%-GEN). We cross-validated the Jackson-Pollock (JP) gene...
Comprehensive Assessment of Emotional Disturbance: A Cross-Validation Approach
ERIC Educational Resources Information Center
Fisher, Emily S.; Doyon, Katie E.; Saldana, Enrique; Allen, Megan Redding
2007-01-01
Assessing a student for emotional disturbance is a serious and complex task given the stigma of the label and the ambiguities of the federal definition. One way that school psychologists can be more confident in their assessment results is to cross validate data from different sources using the RIOT approach (Review, Interview, Observe, Test).…
ERIC Educational Resources Information Center
Yamkovenko, Bogdan V.; Holton, Elwood, III; Bates, R. A.
2007-01-01
Purpose: The purpose of this research is to expand cross-cultural research and validate the Learning Transfer System Inventory in Ukraine. The researchers seek to translate the LTSI into Ukrainian and investigate the internal structure of this translated version of the questionnaire. Design/methodology/approach: The LTSI is translated into…
Validation of annual growth rings in freshwater mussel shells using cross dating .Can
Andrew L. Rypel; Wendell R. Haag; Robert H. Findlay
2009-01-01
We examined the usefulness of dendrochronological cross-dating methods for studying long-term, interannual growth patterns in freshwater mussels, including validation of annual shell ring formation. Using 13 species from three rivers, we measured increment widths between putative annual rings on shell thin sections and then removed age-related variation by...
Cross-Cultural Validation of Stages of Exercise Change Scale among Chinese College Students
ERIC Educational Resources Information Center
Keating, Xiaofen D.; Guan, Jianmin; Huang, Yong; Deng, Mingying; Wu, Yifeng; Qu, Shuhua
2005-01-01
The purpose of the study was to test the cross-cultural concurrent validity of the stages of exercise change scale (SECS) in Chinese college students. The original SECS was translated into Chinese (C-SECS). Students from four Chinese universities (N = 1843) participated in the study. The leisure-time exercise (LTE) questionnaire was used to…
[Maslach Burnout Inventory - Student Survey: Portugal-Brazil cross-cultural adaptation].
Campos, Juliana Alvares Duarte Bonini; Maroco, João
2012-10-01
To perform a cross-cultural adaptation of the Portuguese version of the Maslach Burnout Inventory for students (MBI-SS), and investigate its reliability, validity and cross-cultural invariance. The face validity involved the participation of a multidisciplinary team. Content validity was performed. The Portuguese version was completed in 2009, on the internet, by 958 Brazilian and 556 Portuguese university students from the urban area. Confirmatory factor analysis was carried out using as fit indices: the χ²/df, the Comparative Fit Index (CFI), the Goodness of Fit Index (GFI) and the Root Mean Square Error of Approximation (RMSEA). To verify the stability of the factor solution according to the original English version, cross-validation was performed in 2/3 of the total sample and replicated in the remaining 1/3. Convergent validity was estimated by the average variance extracted and composite reliability. The discriminant validity was assessed, and the internal consistency was estimated by the Cronbach's alpha coefficient. Concurrent validity was estimated by the correlational analysis of the mean scores of the Portuguese version and the Copenhagen Burnout Inventory, and the divergent validity was compared to the Beck Depression Inventory. The invariance of the model between the Brazilian and the Portuguese samples was assessed. The three-factor model of Exhaustion, Disengagement and Efficacy showed good fit (c 2/df = 8.498, CFI = 0.916, GFI = 0.902, RMSEA = 0.086). The factor structure was stable (λ:χ²dif = 11.383, p = 0.50; Cov: χ²dif = 6.479, p = 0.372; Residues: χ²dif = 21.514, p = 0.121). Adequate convergent validity (VEM = 0.45;0.64, CC = 0.82;0.88), discriminant (ρ² = 0.06;0.33) and internal consistency (α = 0.83;0.88) were observed. The concurrent validity of the Portuguese version with the Copenhagen Inventory was adequate (r = 0.21, 0.74). The assessment of the divergent validity was impaired by the approach of the theoretical concept of the dimensions Exhaustion and Disengagement of the Portuguese version with the Beck Depression Inventory. Invariance of the instrument between the Brazilian and Portuguese samples was not observed (λ:χ²dif = 84.768, p<0.001; Cov: χ²dif = 129.206, p < 0.001; Residues: χ²dif = 518.760, p < 0.001). The Portuguese version of the Maslach Burnout Inventory for students showed adequate reliability and validity, but its factor structure was not invariant between the countries, indicating the absence of cross-cultural stability.
Using simple artificial intelligence methods for predicting amyloidogenesis in antibodies
2010-01-01
Background All polypeptide backbones have the potential to form amyloid fibrils, which are associated with a number of degenerative disorders. However, the likelihood that amyloidosis would actually occur under physiological conditions depends largely on the amino acid composition of a protein. We explore using a naive Bayesian classifier and a weighted decision tree for predicting the amyloidogenicity of immunoglobulin sequences. Results The average accuracy based on leave-one-out (LOO) cross validation of a Bayesian classifier generated from 143 amyloidogenic sequences is 60.84%. This is consistent with the average accuracy of 61.15% for a holdout test set comprised of 103 AM and 28 non-amyloidogenic sequences. The LOO cross validation accuracy increases to 81.08% when the training set is augmented by the holdout test set. In comparison, the average classification accuracy for the holdout test set obtained using a decision tree is 78.64%. Non-amyloidogenic sequences are predicted with average LOO cross validation accuracies between 74.05% and 77.24% using the Bayesian classifier, depending on the training set size. The accuracy for the holdout test set was 89%. For the decision tree, the non-amyloidogenic prediction accuracy is 75.00%. Conclusions This exploratory study indicates that both classification methods may be promising in providing straightforward predictions on the amyloidogenicity of a sequence. Nevertheless, the number of available sequences that satisfy the premises of this study are limited, and are consequently smaller than the ideal training set size. Increasing the size of the training set clearly increases the accuracy, and the expansion of the training set to include not only more derivatives, but more alignments, would make the method more sound. The accuracy of the classifiers may also be improved when additional factors, such as structural and physico-chemical data, are considered. The development of this type of classifier has significant applications in evaluating engineered antibodies, and may be adapted for evaluating engineered proteins in general. PMID:20144194
Akinpelu, Aderonke O; Odetunde, Marufat O; Odole, Adesola C
2012-12-01
Stroke-Specific Quality of Life 2.0 (SS-QoL 2.0) scale is used widely and has been cross-culturally adapted to many languages. This study aimed at the cross-cultural adaptation of SS-QoL 2.0 to Yoruba, the indigenous language of south-western Nigeria, and to carry out an initial investigation on its validity. English SS-QoL 2.0 was first adapted to Yoruba language by including Yoruba culture-specific examples in items SC4, UE2 and UE6. The adapted English version (AEV) was independently translated into Yoruba by two language experts who later agreed on a consensus translation, which was then back translated, subjected to an expert committee review and pretested; a cognitive debriefing interview was also carried out to generate the Yoruba translated version (YTV). Thirty-five stroke survivors completed the AEV and Yoruba version (YV) in English and Yoruba. The order of administration was randomized. Data were analysed using Spearman's rank order correlation and Wilcoxon's signed-rank test at a P value less than 0.05. The mean age of the participants (23 men, 12 women) was 58.5±11.3 years. The domain scores of the participants on AEV and YV did not differ significantly, except in the work/productivity domain. In both versions, the mean domain score of the participants was the highest in the language domain [22.6±3.8 (AEV) and 22.7±3.4 (YV)] and the lowest in the work domain [9.0±3.7 (AEV) and 8.0±3.3 (YTV)]. Domain scores on both versions correlated significantly (P<0.05). Participants' ratings of their current state and prestroke state correlated significantly (P<0.01) in all the general areas, except energy and mood. The YTV of SS-QoL 2.0 fulfilled the initial criteria for validity.
Using simple artificial intelligence methods for predicting amyloidogenesis in antibodies.
David, Maria Pamela C; Concepcion, Gisela P; Padlan, Eduardo A
2010-02-08
All polypeptide backbones have the potential to form amyloid fibrils, which are associated with a number of degenerative disorders. However, the likelihood that amyloidosis would actually occur under physiological conditions depends largely on the amino acid composition of a protein. We explore using a naive Bayesian classifier and a weighted decision tree for predicting the amyloidogenicity of immunoglobulin sequences. The average accuracy based on leave-one-out (LOO) cross validation of a Bayesian classifier generated from 143 amyloidogenic sequences is 60.84%. This is consistent with the average accuracy of 61.15% for a holdout test set comprised of 103 AM and 28 non-amyloidogenic sequences. The LOO cross validation accuracy increases to 81.08% when the training set is augmented by the holdout test set. In comparison, the average classification accuracy for the holdout test set obtained using a decision tree is 78.64%. Non-amyloidogenic sequences are predicted with average LOO cross validation accuracies between 74.05% and 77.24% using the Bayesian classifier, depending on the training set size. The accuracy for the holdout test set was 89%. For the decision tree, the non-amyloidogenic prediction accuracy is 75.00%. This exploratory study indicates that both classification methods may be promising in providing straightforward predictions on the amyloidogenicity of a sequence. Nevertheless, the number of available sequences that satisfy the premises of this study are limited, and are consequently smaller than the ideal training set size. Increasing the size of the training set clearly increases the accuracy, and the expansion of the training set to include not only more derivatives, but more alignments, would make the method more sound. The accuracy of the classifiers may also be improved when additional factors, such as structural and physico-chemical data, are considered. The development of this type of classifier has significant applications in evaluating engineered antibodies, and may be adapted for evaluating engineered proteins in general.
Cross-cultural Adaptation of the Oral Anticoagulation Knowledge Test to the Brazilian Portuguese.
Praxedes, Marcus Fernando da Silva; Abreu, Mauro Henrique Nogueira Guimarães; Ribeiro, Daniel Dias; Marcolino, Milena Soriano; Paiva, Saul Martins de; Martins, Maria Auxiliadora Parreiras
2017-05-01
Patients' knowledge about oral anticoagulant therapy may favor the achievement of therapeutic results and the prevention of adverse pharmacotherapy-related events. Brazil lacks validated instruments for assessing the patient's knowledge about treatment with warfarin. This study aimed to perform the cross-cultural adaptation of the Oral Anticoagulation Knowledge (OAK) Test instrument from English into Portuguese. This is a methodological study developed in an anticoagulation clinic of a public university hospital. The study included initial translation, synthesis of translations, back-translation, review by the experts committee and pre-testing with 30 individuals. We obtained semantic equivalence through the analysis of the referential and general meaning of each item. The conceptual equivalence of the items sought to demonstrate the relevance and acceptability of the instrument. The process of cross-cultural adaptation produced the final version of the OAK Test in Brazilian Portuguese entitled "Teste de Conhecimento sobre Anticoagulação Oral". There was a suitable semantic and conceptual equivalence between the adapted version and the original version, as well as an excellent acceptability of this instrument.
Validation of the Cross-Cultural Alcoholism Screening Test (CCAST).
Gorenc, K D; Peredo, S; Pacurucu, S; Llanos, R; Vincente, B; López, R; Abreu, L F; Paez, E
1999-01-01
When screening instruments that are used in the assessment and diagnosis of alcoholism of individuals from different ethnicities, some cultural variables based on norms and societal acceptance of drinking behavior can play an important role in determining the outcome. The accepted diagnostic criteria of current market testing are based on Western standards. In this study, the Munich Alcoholism Test (31 items) was the base instrument applied to subjects from several Hispanic-American countries (Bolivia, Chile, Ecuador, Mexico, and Peru). After the sample was submitted to several statistical procedures, these 31 items were reduced to a culture-free, 31-item test named the Cross-Cultural Alcohol Screening Test (CCAST). The results of this Hispanic-American sample (n = 2,107) empirically demonstrated that CCAST measures alcoholism with an adequate degree of accuracy when compared to other available cross-cultural tests. CCAST is useful in the diagnosis of alcoholism in Spanish-speaking immigrants living in countries where English is spoken. CCAST can be used in general hospitals, psychiatric wards, emergency services and police stations. The test can be useful for other professionals, such as psychological consultants, researchers, and those conducting expertise appraisal.
NASA Astrophysics Data System (ADS)
Jeong, Jina; Park, Eungyu; Shik Han, Weon; Kim, Kue-Young; Suk, Heejun; Beom Jo, Si
2018-07-01
A generalized water table fluctuation model based on precipitation was developed using a statistical conceptualization of unsaturated infiltration fluxes. A gamma distribution function was adopted as a transfer function due to its versatility in representing recharge rates with temporally dispersed infiltration fluxes, and a Laplace transformation was used to obtain an analytical solution. To prove the general applicability of the model, convergences with previous water table fluctuation models were shown as special cases. For validation, a few hypothetical cases were developed, where the applicability of the model to a wide range of unsaturated zone conditions was confirmed. For further validation, the model was applied to water table level estimations of three monitoring wells with considerably thick unsaturated zones on Jeju Island. The results show that the developed model represented the pattern of hydrographs from the two monitoring wells fairly well. The lag times from precipitation to recharge estimated from the developed system transfer function were found to agree with those from a conventional cross-correlation analysis. The developed model has the potential to be adopted for the hydraulic characterization of both saturated and unsaturated zones by being calibrated to actual data when extraneous and exogenous causes of water table fluctuation are limited. In addition, as it provides reference estimates, the model can be adopted as a tool for surveilling groundwater resources under hydraulically stressed conditions.
Frauendorf, Renata; de Medeiros Pinheiro, Marcelo; Ciconelli, Rozana Mesquita
2014-12-01
Loss of productivity at work, as a result of health problems, is becoming an issue of interest due to the high burden it represents in society. The measurement of such phenomenon can be made using generic and specific scales for certain diseases such as the Stanford Presenteeism Scale (SPS-6) and the Work Instability Scale for Ankylosing Spondylitis (AS-WIS), specific for patients with ankylosing spondylitis (AS). The aim of this study was to translate and perform a cross-cultural adaptation of SPS-6 and AS-WIS into Portuguese and check their psychometric properties. The study also aimed to evaluate the relationship between the general scores of the scales and the main sociodemographic and clinical data, lifestyles, and absenteeism in patients with AS and correlate these variables with SPS-6 and AS-WIS scales. A sample of 120 patients with AS and 80 workers at a university hospital was evaluated. The processes for the translation and cross-cultural adaptation of the instruments followed preestablished steps and rules presented in the literature. For the evaluation of measurement properties and correlations between scales, intra-class correlation coefficient (reproducibility analysis), Cronbach alpha (internal consistency), and Pearson correlation coefficient (validity) were employed. The inter-observer (0.986) and intra-observer (0.992) reproducibilities of the AS-WIS were shown to be high as well as the internal consistency (0.995). Similarly, the inter-observer reliability of SPS-6 was considered good (0.890), although it showed a poorer performance when considering the same observer (Pearson correlation coefficient = 0.675 and intra-class correlation = 0.656). Internal consistency, for the total number of items, as measured by Cronbach alpha, was 0.889. The validity of the scales was evaluated thru the comparison of the achieved scores with the results of the WLQ, SF-36, ASQoL, BASFI, BASDAI, HAQ-S, and SRQ-20 instruments. Correlations between loss of productivity at work, worse quality of life, presence of emotional disturbances, and worse health conditions were positive. The process of translation, cross-cultural adaptation, and validation of the SPS-6 as a generic measurement for the loss of productivity at work and of the AS-WIS as a specific measurement for patients with AS are valid, reproducible, and specific instruments to be used in Brazil. In both scales, productivity at work was associated to advanced age, higher rate of absenteeism in the last month and year, presence of peripheral arthritis, and a larger number of comorbidities in patients with AS. The AS-WIS and SPS-6 showed a good correlation among them although they are not mutually exclusive but supplementary.
Validation of the Economic and Health Outcomes Model of Type 2 Diabetes Mellitus (ECHO-T2DM).
Willis, Michael; Johansen, Pierre; Nilsson, Andreas; Asseburg, Christian
2017-03-01
The Economic and Health Outcomes Model of Type 2 Diabetes Mellitus (ECHO-T2DM) was developed to address study questions pertaining to the cost-effectiveness of treatment alternatives in the care of patients with type 2 diabetes mellitus (T2DM). Naturally, the usefulness of a model is determined by the accuracy of its predictions. A previous version of ECHO-T2DM was validated against actual trial outcomes and the model predictions were generally accurate. However, there have been recent upgrades to the model, which modify model predictions and necessitate an update of the validation exercises. The objectives of this study were to extend the methods available for evaluating model validity, to conduct a formal model validation of ECHO-T2DM (version 2.3.0) in accordance with the principles espoused by the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) and the Society for Medical Decision Making (SMDM), and secondarily to evaluate the relative accuracy of four sets of macrovascular risk equations included in ECHO-T2DM. We followed the ISPOR/SMDM guidelines on model validation, evaluating face validity, verification, cross-validation, and external validation. Model verification involved 297 'stress tests', in which specific model inputs were modified systematically to ascertain correct model implementation. Cross-validation consisted of a comparison between ECHO-T2DM predictions and those of the seminal National Institutes of Health model. In external validation, study characteristics were entered into ECHO-T2DM to replicate the clinical results of 12 studies (including 17 patient populations), and model predictions were compared to observed values using established statistical techniques as well as measures of average prediction error, separately for the four sets of macrovascular risk equations supported in ECHO-T2DM. Sub-group analyses were conducted for dependent vs. independent outcomes and for microvascular vs. macrovascular vs. mortality endpoints. All stress tests were passed. ECHO-T2DM replicated the National Institutes of Health cost-effectiveness application with numerically similar results. In external validation of ECHO-T2DM, model predictions agreed well with observed clinical outcomes. For all sets of macrovascular risk equations, the results were close to the intercept and slope coefficients corresponding to a perfect match, resulting in high R 2 and failure to reject concordance using an F test. The results were similar for sub-groups of dependent and independent validation, with some degree of under-prediction of macrovascular events. ECHO-T2DM continues to match health outcomes in clinical trials in T2DM, with prediction accuracy similar to other leading models of T2DM.
Stevanovic, Dejan; Jafari, Peyman; Knez, Rajna; Franic, Tomislav; Atilola, Olayinka; Davidovic, Nikolina; Bagheri, Zahra; Lakic, Aneta
2017-02-01
In this systematic review, we assessed available evidence for cross-cultural measurement invariance of assessment scales for child and adolescent psychopathology as an indicator of cross-cultural validity. A literature search was conducted using the Medline, PsychInfo, Scopus, Web of Science, and Google Scholar databases. Cross-cultural measurement invariance data was available for 26 scales. Based on the aggregation of the evidence from the studies under review, none of the evaluated scales have strong evidence for cross-cultural validity and suitability for cross-cultural comparison. A few of the studies showed a moderate level of measurement invariance for some scales (such as the Fear Survey Schedule for Children-Revised, Multidimensional Anxiety Scale for Children, Revised Child Anxiety and Depression Scale, Revised Children's Manifest Anxiety Scale, Mood and Feelings Questionnaire, and Disruptive Behavior Rating Scale), which may make them suitable in cross-cultural comparative studies. The remainder of the scales either showed weak or outright lack of measurement invariance. This review showed only limited testing for measurement invariance across cultural groups of scales for pediatric psychopathology, with evidence of cross-cultural validity for only a few scales. This study also revealed a need to improve practices of statistical analysis reporting in testing measurement invariance. Implications for future research are discussed.
A variational approach to the study of capillary phenomena
NASA Technical Reports Server (NTRS)
Emmer, M.; Gonzalez, E.; Tamanini, I.
1982-01-01
The problem of determining the free surface of a liquid in a capillary tube, and of a liquid drop, sitting first on a horizontal plane and then on more general surfaces is considered. With some modifications, the method applies to the study of pendent drops and of rotating drops as well. The standard capillary problem, i.e. the determination of the free surface of a liquid in a thin tube of general cross section, which resuls from the simultaneous action of surface tension, boundary adhesion and gravity is discussed. It turns out that in this case the existence of the solution surface depends heavily on the validity of a simple geometric condition about the mean curvature of the boundary curve of the cross section of the capillary tube. Some particular examples of physical interest are also be discussed. Liquid drops sitting on or hanging from a fixed horizontal plane are discussed. The symmetry of the solutions (which can actually be proved, as consequence of a general symmetrization argument) now plays the chief role in deriving both the existence and the regularity of energy-minimizing configurations. When symmetry fails (this is the case, for example, when the contact angle between the drop and the plate is not constant, or when the supporting surface is not itself symmetric), then more sophisticated methods must be used. Extensions in this direction are outlined.
Golpour-Hamedani, Sahar; Mohammadifard, Noushin; Khosravi, Alireza; Feizi, Awat; Safavi, Sayyed Morteza
2017-01-01
Few studies have investigated the effects of dietary approaches to stop hypertension (DASH) diet on obesity in children. The present study was conducted to examine adherence to the DASH diet in relation to obesity in children and adolescents, Isfahan, Iran. A cross-sectional study was carried out among 456 children aged 11-18 years who were selected by random cluster sampling method. Dietary intakes were assessed using a validated Food Frequency Questionnaire (FFQ). The DASH score was constructed based on food items emphasized or minimized in the DASH diet. Anthropometric measurements were conducted based on standard protocols. General and abdominal obesity were defined based on body mass index ≥ 95th percentiles and waist: height ratio of more than 0.5, respectively. Higher adherence to DASH diet was inversely associated with general obesity (odds ratioT1 vs. T3 3.34, 95% confidence interval 1.28-8.75); however, after controlling for confounding factors, this association disappeared. Furthermore, higher adherence to DASH diet was negatively associated with central obesity in children, but the relation was not statistically significant. We concluded that there was an inverse nonsignificant association between adherence to DASH diet and general obesity indices after adjustment for potential confounders. Further, well-designed randomized clinical trial studies are suggested to find out the effect of DASH diet on obesity obviously.
Coates, James; Jeyaseelan, Asha K; Ybarra, Norma; David, Marc; Faria, Sergio; Souhami, Luis; Cury, Fabio; Duclos, Marie; El Naqa, Issam
2015-04-01
We explore analytical and data-driven approaches to investigate the integration of genetic variations (single nucleotide polymorphisms [SNPs] and copy number variations [CNVs]) with dosimetric and clinical variables in modeling radiation-induced rectal bleeding (RB) and erectile dysfunction (ED) in prostate cancer patients. Sixty-two patients who underwent curative hypofractionated radiotherapy (66 Gy in 22 fractions) between 2002 and 2010 were retrospectively genotyped for CNV and SNP rs5489 in the xrcc1 DNA repair gene. Fifty-four patients had full dosimetric profiles. Two parallel modeling approaches were compared to assess the risk of severe RB (Grade⩾3) and ED (Grade⩾1); Maximum likelihood estimated generalized Lyman-Kutcher-Burman (LKB) and logistic regression. Statistical resampling based on cross-validation was used to evaluate model predictive power and generalizability to unseen data. Integration of biological variables xrcc1 CNV and SNP improved the fit of the RB and ED analytical and data-driven models. Cross-validation of the generalized LKB models yielded increases in classification performance of 27.4% for RB and 14.6% for ED when xrcc1 CNV and SNP were included, respectively. Biological variables added to logistic regression modeling improved classification performance over standard dosimetric models by 33.5% for RB and 21.2% for ED models. As a proof-of-concept, we demonstrated that the combination of genetic and dosimetric variables can provide significant improvement in NTCP prediction using analytical and data-driven approaches. The improvement in prediction performance was more pronounced in the data driven approaches. Moreover, we have shown that CNVs, in addition to SNPs, may be useful structural genetic variants in predicting radiation toxicities. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Nunez, Jorge; Llacer, Jorge
1993-10-01
This paper describes a general Bayesian iterative algorithm with entropy prior for image reconstruction. It solves the cases of both pure Poisson data and Poisson data with Gaussian readout noise. The algorithm maintains positivity of the solution; it includes case-specific prior information (default map) and flatfield corrections; it removes background and can be accelerated to be faster than the Richardson-Lucy algorithm. In order to determine the hyperparameter that balances the entropy and liklihood terms in the Bayesian approach, we have used a liklihood cross-validation technique. Cross-validation is more robust than other methods because it is less demanding in terms of the knowledge of exact data characteristics and of the point-spread function. We have used the algorithm to reconstruct successfully images obtained in different space-and ground-based imaging situations. It has been possible to recover most of the original intended capabilities of the Hubble Space Telescope (HST) wide field and planetary camera (WFPC) and faint object camera (FOC) from images obtained in their present state. Semireal simulations for the future wide field planetary camera 2 show that even after the repair of the spherical abberration problem, image reconstruction can play a key role in improving the resolution of the cameras, well beyond the design of the Hubble instruments. We also show that ground-based images can be reconstructed successfully with the algorithm. A technique which consists of dividing the CCD observations into two frames, with one-half the exposure time each, emerges as a recommended procedure for the utilization of the described algorithms. We have compared our technique with two commonly used reconstruction algorithms: the Richardson-Lucy and the Cambridge maximum entropy algorithms.
NASA Astrophysics Data System (ADS)
Compton, Duane C.; Snapp, Robert R.
2007-09-01
TWiGS (two-dimensional wavelet transform with generalized cross validation and soft thresholding) is a novel algorithm for denoising liquid chromatography-mass spectrometry (LC-MS) data for use in "shot-gun" proteomics. Proteomics, the study of all proteins in an organism, is an emerging field that has already proven successful for drug and disease discovery in humans. There are a number of constraints that limit the effectiveness of liquid chromatography-mass spectrometry (LC-MS) for shot-gun proteomics, where the chemical signals are typically weak, and data sets are computationally large. Most algorithms suffer greatly from a researcher driven bias, making the results irreproducible and unusable by other laboratories. We thus introduce a new algorithm, TWiGS, that removes electrical (additive white) and chemical noise from LC-MS data sets. TWiGS is developed to be a true two-dimensional algorithm, which operates in the time-frequency domain, and minimizes the amount of researcher bias. It is based on the traditional discrete wavelet transform (DWT), which allows for fast and reproducible analysis. The separable two-dimensional DWT decomposition is paired with generalized cross validation and soft thresholding. The Haar, Coiflet-6, Daubechie-4 and the number of decomposition levels are determined based on observed experimental results. Using a synthetic LC-MS data model, TWiGS accurately retains key characteristics of the peaks in both the time and m/z domain, and can detect peaks from noise of the same intensity. TWiGS is applied to angiotensin I and II samples run on a LC-ESI-TOF-MS (liquid-chromatography-electrospray-ionization) to demonstrate its utility for the detection of low-lying peaks obscured by noise.
A big data approach to the development of mixed-effects models for seizure count data.
Tharayil, Joseph J; Chiang, Sharon; Moss, Robert; Stern, John M; Theodore, William H; Goldenholz, Daniel M
2017-05-01
Our objective was to develop a generalized linear mixed model for predicting seizure count that is useful in the design and analysis of clinical trials. This model also may benefit the design and interpretation of seizure-recording paradigms. Most existing seizure count models do not include children, and there is currently no consensus regarding the most suitable model that can be applied to children and adults. Therefore, an additional objective was to develop a model that accounts for both adult and pediatric epilepsy. Using data from SeizureTracker.com, a patient-reported seizure diary tool with >1.2 million recorded seizures across 8 years, we evaluated the appropriateness of Poisson, negative binomial, zero-inflated negative binomial, and modified negative binomial models for seizure count data based on minimization of the Bayesian information criterion. Generalized linear mixed-effects models were used to account for demographic and etiologic covariates and for autocorrelation structure. Holdout cross-validation was used to evaluate predictive accuracy in simulating seizure frequencies. For both adults and children, we found that a negative binomial model with autocorrelation over 1 day was optimal. Using holdout cross-validation, the proposed model was found to provide accurate simulation of seizure counts for patients with up to four seizures per day. The optimal model can be used to generate more realistic simulated patient data with very few input parameters. The availability of a parsimonious, realistic virtual patient model can be of great utility in simulations of phase II/III clinical trials, epilepsy monitoring units, outpatient biosensors, and mobile Health (mHealth) applications. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.
Shapira Galitz, Yael; Halperin, Doron; Bavnik, Yosef; Warman, Meir
2016-05-01
To perform the translation, cross-cultural adaptation, and validation of the Sino-Nasal Outcome Test-22 (SNOT-22) questionnaire to the Hebrew language. A single-center prospective cross-sectional study. Seventy-three chronic rhinosinusitis (CRS) patients and 73 patients without sinonasal disease filled the Hebrew version of the SNOT-22 questionnaire. Fifty-one CRS patients underwent endoscopic sinus surgery, out of which 28 filled a postoperative questionnaire. Seventy-three healthy volunteers without sinonasal disease also answered the questionnaire. Internal consistency, test-retest reproducibility, validity, and responsiveness of the questionnaire were evaluated. Questionnaire reliability was excellent, with a high internal consistency (Cronbach's alpha coefficient, 0.91-0.936) and test-retest reproducibility (Spearman's coefficient, 0.962). Mean scores for the preoperative, postoperative, and control groups were 50.44, 29.64, and 13.15, respectively (P < .0001 for CRS vs controls, P < .001 for preoperative vs postoperative), showing validity and responsiveness of the questionnaire. The Hebrew version of SNOT-22 questionnaire is a valid outcome measure for patients with CRS with or without nasal polyps. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.
2012-01-01
Background Since few cohorts encompass the whole life-course, many studies that measure socio-economic position (SEP) across the life-course rely on participant recall of SEP measures from cross-sectional postal or interview surveys. It is also particularly important that SEP measures should be appropriate for the age of the population studied, as the level of missing data has been shown to increase in older people. The aim of this study was to investigate the accuracy of recall of two SEP measures in older adults, age left school and longest job, by examining their validity in a general population postal survey in North Staffordshire, UK. Methods Sets of questions on education and longest job were included in a questionnaire at different stages of the study. All patients aged 50+ registered with three general practices were sent a baseline Health Questionnaire. 6 years later, 3410 responders were mailed a follow-up Health Questionnaire; a sub-sample of these participants took part in independent qualitative interviews. Validity was assessed by: percentage completion; internal percentage agreement within each set of questions; percentage agreement of qualitative and quantitative data for age left school and longest job; comparing recall of age left school with historical change in legal school leaving age; comparing frequency of pottery job titles with those in 1981 Census data for Stoke-on-Trent. Results The adjusted response to different stages of the study was 71–85%. Completion of questions was 83–98%. Internal agreement was 84–97% (education) and 95–100% (longest job). Comparison of survey and interview data showed 86% agreement (± 1 year) for age left school and 91% agreement for longest job. The change in age left school data concurred with the historical shift in legal school leaving age. 11% of job titles were pottery in NorStOP data and 15% in Stoke-on-Trent Census data. Conclusions The results from this study provide evidence for the accuracy of recall of two simple measures of SEP (age left school and longest job) in a postal survey of older adults. Consistency with evidence from external datasets indicated the potential validity of these measures for studying life-course SEP in population surveys. PMID:22738317
Sumter, Sindy R; Bokhorst, Caroline L; Steinberg, Laurence; Westenberg, P Michiel
2009-08-01
Common folklore seems to suggest that adolescents are particularly susceptible to peer influence. However, from the literature the exact age differences in susceptibility to peer influence remain unclear. The current study's main focus was to chart the development of general susceptibility to peer pressure in a community sample of 10-18 year olds (N =464) with the recently developed Resistance to Peer Influence Scale (RPI). The one-factor structure of the RPI was cross-validated in the present sample, and the RPI was equally reliable at all ages. As expected, general resistance to peer influence increased during adolescence. In addition, gender differences were most pronounced during mid-adolescence, when girls were more resistant to peer influence than boys. These findings are explained in terms of psychosocial maturation during adolescence.
Fernandez-Miranda, Juan C; Pathak, Sudhir; Engh, Johnathan; Jarbo, Kevin; Verstynen, Timothy; Yeh, Fang-Cheng; Wang, Yibao; Mintz, Arlan; Boada, Fernando; Schneider, Walter; Friedlander, Robert
2012-08-01
High-definition fiber tracking (HDFT) is a novel combination of processing, reconstruction, and tractography methods that can track white matter fibers from cortex, through complex fiber crossings, to cortical and subcortical targets with subvoxel resolution. To perform neuroanatomical validation of HDFT and to investigate its neurosurgical applications. Six neurologically healthy adults and 36 patients with brain lesions were studied. Diffusion spectrum imaging data were reconstructed with a Generalized Q-Ball Imaging approach. Fiber dissection studies were performed in 20 human brains, and selected dissection results were compared with tractography. HDFT provides accurate replication of known neuroanatomical features such as the gyral and sulcal folding patterns, the characteristic shape of the claustrum, the segmentation of the thalamic nuclei, the decussation of the superior cerebellar peduncle, the multiple fiber crossing at the centrum semiovale, the complex angulation of the optic radiations, the terminal arborization of the arcuate tract, and the cortical segmentation of the dorsal Broca area. From a clinical perspective, we show that HDFT provides accurate structural connectivity studies in patients with intracerebral lesions, allowing qualitative and quantitative white matter damage assessment, aiding in understanding lesional patterns of white matter structural injury, and facilitating innovative neurosurgical applications. High-grade gliomas produce significant disruption of fibers, and low-grade gliomas cause fiber displacement. Cavernomas cause both displacement and disruption of fibers. Our HDFT approach provides an accurate reconstruction of white matter fiber tracts with unprecedented detail in both the normal and pathological human brain. Further studies to validate the clinical findings are needed.
Lam, Simon C
2014-05-01
To perform detailed psychometric testing of the compliance with standard precautions scale (CSPS) in measuring compliance with standard precautions of clinical nurses and to conduct cross-cultural pilot testing and assess the relevance of the CSPS on an international platform. A cross-sectional and correlational design with repeated measures. Nursing students from a local registered nurse training university, nurses from different hospitals in Hong Kong, and experts in an international conference. The psychometric properties of the CSPS were evaluated via internal consistency, 2-week and 3-month test-retest reliability, concurrent validation, and construct validation. The cross-cultural pilot testing and relevance check was examined by experts on infection control from various developed and developing regions. Among 453 participants, 193 were nursing students, 165 were enrolled nurses, and 95 were registered nurses. The results showed that the CSPS had satisfactory reliability (Cronbach α = 0.73; intraclass correlation coefficient, 0.79 for 2-week test-retest and 0.74 for 3-month test-retest) and validity (optimum correlation with criterion measure; r = 0.76, P < .001; satisfactory results on known-group method and hypothesis testing). A total of 19 experts from 16 countries assured that most of the CSPS findings were relevant and globally applicable. The CSPS demonstrated satisfactory results on the basis of the standard international criteria on psychometric testing, which ascertained the reliability and validity of this instrument in measuring the compliance of clinical nurses with standard precautions. The cross-cultural pilot testing further reinforced the instrument's relevance and applicability in most developed and developing regions.
Lienhardt, Andrea; Rabenschlag, Franziska; Panfil, Eva-Maria
2018-06-08
The practice of special observation in adults in the German-speaking part of Switzerland - a descriptive cross-sectional study Abstract. Psychiatric Special Observation (PSO) is an intervention often used by nurses to prevent service users of harming themselves or to protect others. The intervention ranges between control and therapy and is resource intensive. Despite the widespread use of PSO, there is still no data on the practice of the intervention in Switzerland. What is the current practice of PSO in adults in psychiatric hospitals in the German-speaking part of Switzerland? Descriptive cross-sectional study. Nurses from inpatient psychiatric services in the German-speaking part of Switzerland completed a questionnaire based on a concept analysis of PSO. 538 questionnaires were analysed. PSO was more often conducted intermittent than as constant observation. In more than one out of four cases, suicidality reasoned as a cause for prescription. Nurses generally used standardized instruments to assess the risk of harming oneself or others. The duration of PSO lasted eight hours or more in three out of four cases. In every fifth case, there was no validation of the need of the intervention taking place during one shift. Nurses have a neutral attitude towards the intervention and are experiencing no or weak negative feelings during performance of PSO. The results suggest that there is an inconsistent performance of PSO in Switzerland as well as in other countries. The validation of the need of the intervention is insufficient. To facilitate PSO as a justified performance, the preparation of an interprofessional guideline is recommended.
O'Reilly, Christian; Gosselin, Nadia; Carrier, Julie; Nielsen, Tore
2014-12-01
Manual processing of sleep recordings is extremely time-consuming. Efforts to automate this process have shown promising results, but automatic systems are generally evaluated on private databases, not allowing accurate cross-validation with other systems. In lacking a common benchmark, the relative performances of different systems are not compared easily and advances are compromised. To address this fundamental methodological impediment to sleep study, we propose an open-access database of polysomnographic biosignals. To build this database, whole-night recordings from 200 participants [97 males (aged 42.9 ± 19.8 years) and 103 females (aged 38.3 ± 18.9 years); age range: 18-76 years] were pooled from eight different research protocols performed in three different hospital-based sleep laboratories. All recordings feature a sampling frequency of 256 Hz and an electroencephalography (EEG) montage of 4-20 channels plus standard electro-oculography (EOG), electromyography (EMG), electrocardiography (ECG) and respiratory signals. Access to the database can be obtained through the Montreal Archive of Sleep Studies (MASS) website (http://www.ceams-carsm.ca/en/MASS), and requires only affiliation with a research institution and prior approval by the applicant's local ethical review board. Providing the research community with access to this free and open sleep database is expected to facilitate the development and cross-validation of sleep analysis automation systems. It is also expected that such a shared resource will be a catalyst for cross-centre collaborations on difficult topics such as improving inter-rater agreement on sleep stage scoring. © 2014 European Sleep Research Society.
Evaluation of MuSyQ land surface albedo based on LAnd surface Parameters VAlidation System (LAPVAS)
NASA Astrophysics Data System (ADS)
Dou, B.; Wen, J.; Xinwen, L.; Zhiming, F.; Wu, S.; Zhang, Y.
2016-12-01
satellite derived Land surface albedo is an essential climate variable which controls the earth energy budget and it can be used in applications such as climate change, hydrology, and numerical weather prediction. However, the accuracy and uncertainty of surface albedo products should be evaluated with a reliable reference truth data prior to applications. A new comprehensive and systemic project of china, called the Remote Sensing Application Network (CRSAN), has been launched recent years. Two subjects of this project is developing a Multi-source data Synergized Quantitative Remote Sensin g Production System ( MuSyQ ) and a Web-based validation system named LAnd surface remote sensing Product VAlidation System (LAPVAS) , which aims to generate a quantitative remote sensing product for ecosystem and environmental monitoring and validate them with a reference validation data and a standard validation system, respectively. Land surface BRDF/albedo is one of product datasets of MuSyQ which has a pentad period with 1km spatial resolution and is derived by Multi-sensor Combined BRDF Inversion ( MCBI ) Model. In this MuSyQ albedo evaluation, a multi-validation strategy is implemented by LAPVAS, including directly and multi-scale validation with field measured albedo and cross validation with MODIS albedo product with different land cover. The results reveal that MuSyQ albedo data with a 5-day temporal resolution is in higher sensibility and accuracy during land cover change period, e.g. snowing. But results without regard to snow or changed land cover, MuSyQ albedo generally is in similar accuracy with MODIS albedo and meet the climate modeling requirement of an absolute accuracy of 0.05.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chapman, Bryan Scott; MacQuigg, Michael Robert; Wysong, Andrew Russell
In this document, the code MCNP is validated with ENDF/B-VII.1 cross section data under the purview of ANSI/ANS-8.24-2007, for use with uranium systems. MCNP is a computer code based on Monte Carlo transport methods. While MCNP has wide reading capability in nuclear transport simulation, this validation is limited to the functionality related to neutron transport and calculation of criticality parameters such as k eff.
ERIC Educational Resources Information Center
Zeidner, Moshe
1987-01-01
This study examined the cross-cultural validity of the sex bias contention with respect to standardized aptitude testing, used for academic prediction purposes in Israel. Analyses were based on the grade point average and scores of 1778 Jewish and 1017 Arab students who were administered standardized college entrance test batteries. (Author/LMO)
ERIC Educational Resources Information Center
Wang, Jessica; Lee, Li-Ching; Chen, Ying-Sheue; Hsu, Ju-Wei
2012-01-01
The cross-cultural validity of the Mandarin-adaptation of the social responsiveness scale (SRS) was examined in a sample of N = 307 participants in Taiwan, 140 typically developing and 167 with clinically-diagnosed developmental disorders. This scale is an autism assessment tool that provides a quantitative rather than categorical measure of…
USDA-ARS?s Scientific Manuscript database
Accurate, nonintrusive, and inexpensive techniques are needed to measure energy expenditure (EE) in free-living populations. Our primary aim in this study was to validate cross-sectional time series (CSTS) and multivariate adaptive regression splines (MARS) models based on observable participant cha...
A New Symptom Model for Autism Cross-Validated in an Independent Sample
ERIC Educational Resources Information Center
Boomsma, A.; Van Lang, N. D. J.; De Jonge, M. V.; De Bildt, A. A.; Van Engeland, H.; Minderaa, R. B.
2008-01-01
Background: Results from several studies indicated that a symptom model other than the DSM triad might better describe symptom domains of autism. The present study focused on a) investigating the stability of a new symptom model for autism by cross-validating it in an independent sample and b) examining the invariance of the model regarding three…
Zometa, Carlos S; Dedrick, Robert; Knox, Michael D; Westhoff, Wayne; Siri, Rodrigo Simán; Debaldo, Ann
2007-06-01
An instrument developed in the United States by the Centers for Disease Control and Prevention to assess HIV/AIDS knowledge and four attitudinal dimensions (Peer Pressure, Abstinence, Drug Use, and Threat of HIV Infection) and an instrument developed by Basen-Engquist et al. (1999) to measure abstinence and condom use were translated, cross-culturally adapted, and validated for use with Spanish-speaking high school students in El Salvador. A back-translation of the English version was cross-culturally adapted using two different review panels and pilot-tested with Salvadorian students. An expert panel established content validity, and confirmatory factor analysis provided support for construct validity. Results indicated that the methodology was successful in cross-culturally adapting the instrument developed by the Centers for Disease Control and Prevention and the instrument developed by Basen-Engquist et al. The psychometric properties of the knowledge section were acceptable and there was partial support for the four-factor attitudinal model underlying the CDC instrument and the two-factor model underlying the Basen-Engquist et al. instrument. Additional studies with Spanish-speaking populations (either in the United States or Latin America) are needed to evaluate the generalizability of the present results.
Modeling and Validation of Microwave Ablations with Internal Vaporization
Chiang, Jason; Birla, Sohan; Bedoya, Mariajose; Jones, David; Subbiah, Jeyam; Brace, Christopher L.
2014-01-01
Numerical simulation is increasingly being utilized for computer-aided design of treatment devices, analysis of ablation growth, and clinical treatment planning. Simulation models to date have incorporated electromagnetic wave propagation and heat conduction, but not other relevant physics such as water vaporization and mass transfer. Such physical changes are particularly noteworthy during the intense heat generation associated with microwave heating. In this work, a numerical model was created that integrates microwave heating with water vapor generation and transport by using porous media assumptions in the tissue domain. The heating physics of the water vapor model was validated through temperature measurements taken at locations 5, 10 and 20 mm away from the heating zone of the microwave antenna in homogenized ex vivo bovine liver setup. Cross-sectional area of water vapor transport was validated through intra-procedural computed tomography (CT) during microwave ablations in homogenized ex vivo bovine liver. Iso-density contours from CT images were compared to vapor concentration contours from the numerical model at intermittent time points using the Jaccard Index. In general, there was an improving correlation in ablation size dimensions as the ablation procedure proceeded, with a Jaccard Index of 0.27, 0.49, 0.61, 0.67 and 0.69 at 1, 2, 3, 4, and 5 minutes. This study demonstrates the feasibility and validity of incorporating water vapor concentration into thermal ablation simulations and validating such models experimentally. PMID:25330481
Measuring Psychobiosocial States in Sport: Initial Validation of a Trait Measure
Bertollo, Maurizio; Ruiz, Montse C.; Bortoli, Laura
2016-01-01
We examined the item characteristics, the factor structure, and the concurrent validity of a trait measure of psychobiosocial states. In Study 1, Italian athletes (N = 342, 228 men, 114 women, Mage = 23.93, SD = 6.64) rated the intensity, the frequency, and the perceived impact dimensions of a psychobiosocial states scale, trait version (PBS-ST), which is composed of 20 items (10 functional and 10 dysfunctional) referring to how they usually felt before an important competition. In Study 2, the scale was cross validated in an independent sample (N = 251, 181 men, 70 women, Mage = 24.35, SD = 7.25). The concurrent validity of the PBS-ST scale scores were also examined in comparison with two sport-specific emotion-related measures and a general measure of affect. Exploratory structural equation modeling and confirmatory factor analysis of the data of Study 1 showed that a 2-factor, 15-item solution of the PBS-ST scale (8 functional items and 7 dysfunctional items) reached satisfactory fit indices for the three dimensions (i.e., intensity, frequency, and perceived impact). Results of Study 2 provided evidence of substantial measurement and structural invariance of all dimensions across samples. The low association of the PBS-ST scale with other measures suggests that the scale taps unique constructs. Findings of the two studies offer initial validity evidence for a sport-specific tool to measure psychobiosocial states. PMID:27907111
Medina, Maria Del Mar; Carrillo, Alvaro; Polo, Ruben; Fernandez, Borja; Alonso, Daniel; Vaca, Miguel; Cordero, Adela; Perez, Cecilia; Muriel, Alfonso; Cobeta, Ignacio
2017-04-01
Objective To perform translation, cross-cultural adaptation, and validation of the Penn Acoustic Neuroma Quality-of-Life Scale (PANQOL) to the Spanish language. Study Design Prospective study. Setting Tertiary neurotologic referral center. Subjects and Methods PANQOL was translated and translated back, and a pretest trial was performed. The study included 27 individuals diagnosed with vestibular schwannoma. Inclusion criteria were adults with untreated vestibular schwannoma, diagnosed in the past 12 months. Feasibility, internal consistency, test-retest reliability, construct validity, and ceiling and floor effects were assessed for the present study. Results The mean overall score of the PANQOL was 69.21 (0-100 scale, lowest to highest quality of life). Cronbach's α was 0.87. Intraclass correlation coefficient was performed for each item, with an overall score of 0.92. The κ coefficient scores were between moderate and almost perfect in more than 92% of patients. Anxiety and energy domains of the PANQOL were correlated with both physical and mental components of the SF-12. Hearing, balance, and pain domains were correlated with the SF-12 physical component. Facial and general domains were not significantly correlated with any component of the SF-12. Furthermore, the overall score of the PANQOL was correlated with the physical component of the SF-12. Conclusion Feasibility, internal consistency, reliability, and construct validity outcomes in the current study support the validity of the Spanish version of the PANQOL.
Lo, Brian K C; Minaker, Leia; Chan, Alicia N T; Hrgetic, Jessica; Mah, Catherine L
2016-03-01
To adapt and validate a survey instrument to assess the nutrition environment of grab-and-go establishments at a university campus. A version of the Nutrition Environment Measures Survey for grab-and-go establishments (NEMS-GG) was adapted from existing NEMS instruments and tested for reliability and validity through a cross-sectional assessment of the grab-and-go establishments at the University of Toronto. Product availability, price, and presence of nutrition information were evaluated. Cohen's kappa coefficient and intra-class correlation coefficients (ICC) were assessed for inter-rater reliability, and construct validity was assessed using the known-groups comparison method (via store scores). Fifteen grab-and-go establishments were assessed. Inter-rater reliability was high with an almost perfect agreement for availability (mean κ = 0.995) and store scores (ICC = 0.999). The tool demonstrated good face and construct validity. About half of the venues carried fruit and vegetables (46.7% and 53.3%, respectively). Regular and healthier entrée items were generally the same price. Healthier grains were cheaper than regular options. Six establishments displayed nutrition information. Establishments operated by the university's Food Services consistently scored the highest across all food premise types for nutrition signage, availability, and cost of healthier options. Health promotion strategies are needed to address availability and variety of healthier grab-and-go options in university settings.
Castillo-Tandazo, Wilson; Flores-Fortty, Adolfo; Feraud, Lourdes; Tettamanti, Daniel
2013-01-01
Purpose To translate, cross-culturally adapt, and validate the Questionnaire for Diabetes-Related Foot Disease (Q-DFD), originally created and validated in Australia, for its use in Spanish-speaking patients with diabetes mellitus. Patients and methods The translation and cross-cultural adaptation were based on international guidelines. The Spanish version of the survey was applied to a community-based (sample A) and a hospital clinic-based sample (samples B and C). Samples A and B were used to determine criterion and construct validity comparing the survey findings with clinical evaluation and medical records, respectively; while sample C was used to determine intra- and inter-rater reliability. Results After completing the rigorous translation process, only four items were considered problematic and required a new translation. In total, 127 patients were included in the validation study: 76 to determine criterion and construct validity and 41 to establish intra- and inter-rater reliability. For an overall diagnosis of diabetes-related foot disease, a substantial level of agreement was obtained when we compared the Q-DFD with the clinical assessment (kappa 0.77, sensitivity 80.4%, specificity 91.5%, positive likelihood ratio [LR+] 9.46, negative likelihood ratio [LR−] 0.21); while an almost perfect level of agreement was obtained when it was compared with medical records (kappa 0.88, sensitivity 87%, specificity 97%, LR+ 29.0, LR− 0.13). Survey reliability showed substantial levels of agreement, with kappa scores of 0.63 and 0.73 for intra- and inter-rater reliability, respectively. Conclusion The translated and cross-culturally adapted Q-DFD showed good psychometric properties (validity, reproducibility, and reliability) that allow its use in Spanish-speaking diabetic populations. PMID:24039434
Psychometric validation of a condom self-efficacy scale in Korean.
Cha, EunSeok; Kim, Kevin H; Burke, Lora E
2008-01-01
When an instrument is translated for use in cross-cultural research, it needs to account for cultural factors without distorting the psychometric properties of the instrument. To validate the psychometric properties of the condom self-efficacy scale (CSE) originally developed for American adolescents and young adults after translating the scale to Korean (CSE-K) to determine its suitability for cross-cultural research among Korean college students. A cross-sectional, correlational design was used with an exploratory survey methodology through self-report questionnaires. A convenience sample of 351 students, aged 18 to 25 years, were recruited at a university in Seoul, Korea. The participants completed the CSE-K and the intention of condom use scales after they were translated from English to Korean using a combined translation technique. A demographic and sex history questionnaire, which included an item to assess actual condom usage, was also administered. Mean, variance, reliability, criterion validity, and factorial validity using confirmatory factor analysis were assessed in the CSE-K. Norms for the CSE-K were similar, but not identical, to norms for the English version. The means of all three subscales were lower for the CSE-K than for the original CSE; however, the obtained variance in CSE-K was roughly similar with the original CSE. The Cronbach's alpha coefficient for the total scale was higher for the CSE-K (.91) than that for either the CSE (.85) or CSE in Thai (.85). Criterion validity and construct validity of the CSE-K were confirmed. The CSE-K was a reliable and valid scale in measuring condom self-efficacy among Korean college students. The findings suggest that the CSE was an appropriate instrument to conduct cross-cultural research on sexual behavior in adolescents and young adults.
Zambelli, Roberto; Pinto, Rafael Z; Magalhães, João Murilo Brandão; Lopes, Fernando Araujo Silva; Castilho, Rodrigo Simões; Baumfeld, Daniel; Dos Santos, Thiago Ribeiro Teles; Maffulli, Nicola
2016-01-01
There is a need for a patient-relevant instrument to evaluate outcome after treatment in patients with a total Achilles tendon rupture. The purpose of this study was to undertake a cross-cultural adaptation of the Achilles Tendon Total Rupture Score (ATRS) into Brazilian Portuguese, determining the test-retest reliability and construct validity of the instrument. A five-step approach was used in the cross-cultural adaptation process: initial translation (two bilingual Brazilian translators), synthesis of translation, back-translation (two native English language translators), consensus version and evaluation (expert committee), and testing phase. A total of 46 patients were recruited to evaluate the test-retest reproducibility and construct validity of the Brazilian Portuguese version of the ATRS. Test-retest reproducibility was performed by assessing each participant on two separate occasions. The construct validity was determined by the correlation index between the ATRS and the Orthopedic American Foot and Ankle Society (AOFAS) questionnaires. The final version of the Brazilian Portuguese ATRS had the same number of questions as the original ATRS. For the reliability analysis, an ICC(2,1) of 0.93 (95 % CI: 0.88 to 0.96) with SEM of 1.56 points and MDC of 4.32 was observed, indicating excellent reliability. The construct validity showed excellent correlation with R = 0.76 (95 % CI: 0.52 to 0.89, P < 0.001). The ATRS was successfully cross-culturally validated into Brazilian Portuguese. This version was a reliable and valid measure of function in patients who suffered complete rupture of the Achilles Tendon.
2017-01-01
Objective To perform a translation and cross-cultural adaptation of the Cardiac Rehabilitation Barriers Scale (CRBS) for use in Korea, followed by psychometric validation. The CRBS was developed to assess patients' perception of the degree to which patient, provider and health system-level barriers affect their cardiac rehabilitation (CR) participation. Methods The CRBS consists of 21 items (barriers to adherence) rated on a 5-point Likert scale. The first phase was to translate and cross-culturally adapt the CRBS to the Korean language. After back-translation, both versions were reviewed by a committee. The face validity was assessed in a sample of Korean patients (n=53) with history of acute myocardial infarction that did not participate in CR through semi-structured interviews. The second phase was to assess the construct and criterion validity of the Korean translation as well as internal reliability, through administration of the translated version in 104 patients, principle component analysis with varimax rotation and cross-referencing against CR use, respectively. Results The length, readability, and clarity of the questionnaire were rated well, demonstrating face validity. Analysis revealed a six-factor solution, demonstrating construct validity. Cronbach's alpha was greater than 0.65. Barriers rated highest included not knowing about CR and not being contacted by a program. The mean CRBS score was significantly higher among non-attendees (2.71±0.26) than CR attendees (2.51±0.18) (p<0.01). Conclusion The Korean version of CRBS has demonstrated face, content and criterion validity, suggesting it may be useful for assessing barriers to CR utilization in Korea. PMID:29201826
Validation of the Hungarian version of Carlson's Work-Family Conflict Scale.
Ádám, Szilvia; Konkoly Thege, Barna
2017-11-30
Work-family conflict has been associated with adverse individual (e.g., cardiovascular diseases, anxiety disorders), organizational (e.g., absenteeism, lower productivity), and societal outcomes (e.g., increased use of healthcare services). However, lack of standardized measurement has hindered the comparison of data across various cultures. The purpose of this study was to develop the Hungarian version of Carlson et al.'s multidimensional Work-Family Conflict Scale and establish its reliability and validity. In a sample of 557 employees (145 men and 412 women), we conducted confirmatory factor analysis to investigate the factor structure and factorial invariance of the instrument across sex and data collection points and evaluated the tool's validity by assessing relationships between its dimensions and scales measuring general, marital, and job-related stress, depressive symptomatology, vital exhaustion, functional somatic symptoms, and social support. Our results showed that a six-factor model, similarly to that of the original instrument, fit the data best. Internal consistency of the six dimensions and the whole instrument was adequate. Convergent and divergent validity of the instrument and discriminant validity of the dimensions were also supported by our data. This study provides empirical support for the validity and reliability of the Hungarian version of the multidimensional Work-Family Conflict Scale. Deployment of this measure may allow for the generation of data that can be compared to those obtained in different cultural settings with the same instrument and hence advance our understanding of cross-cultural aspects of work-family conflict.
Schmettow, Martin; Schnittker, Raphaela; Schraagen, Jan Maarten
2017-05-01
This paper proposes and demonstrates an extended protocol for usability validation testing of medical devices. A review of currently used methods for the usability evaluation of medical devices revealed two main shortcomings. Firstly, the lack of methods to closely trace the interaction sequences and derive performance measures. Secondly, a prevailing focus on cross-sectional validation studies, ignoring the issues of learnability and training. The U.S. Federal Drug and Food Administration's recent proposal for a validation testing protocol for medical devices is then extended to address these shortcomings: (1) a novel process measure 'normative path deviations' is introduced that is useful for both quantitative and qualitative usability studies and (2) a longitudinal, completely within-subject study design is presented that assesses learnability, training effects and allows analysis of diversity of users. A reference regression model is introduced to analyze data from this and similar studies, drawing upon generalized linear mixed-effects models and a Bayesian estimation approach. The extended protocol is implemented and demonstrated in a study comparing a novel syringe infusion pump prototype to an existing design with a sample of 25 healthcare professionals. Strong performance differences between designs were observed with a variety of usability measures, as well as varying training-on-the-job effects. We discuss our findings with regard to validation testing guidelines, reflect on the extensions and discuss the perspectives they add to the validation process. Copyright © 2017 Elsevier Inc. All rights reserved.
Campos, Juliana Alvares Duarte Bonini; Spexoto, Maria Cláudia Bernardes; Serrano, Sergio Vicente; Maroco, João
2016-01-13
The psychometric properties of an instrument should be evaluated routinely when using different samples. This study evaluated the psychometric properties of the Functional Assessment of Cancer Therapy-General (FACT-G) when applied to a sample of Brazilian cancer patients. The face, content, and construct (factorial, convergent, and discriminant) validities of the FACT-G were estimated. Confirmatory factor analysis (CFA) was conducted the ratio chi-square by degrees of freedom (χ (2)/df), the comparative fit index (CFI), the Tucker-Lewis index (TLI), and the root mean square error of approximation (RMSEA) as indices. The invariance of the best model was assessed with multi-group analysis using the difference of chi-squares method (Δχ(2)). Convergent validity was assessed using Average Variance Extracted (AVE) and discriminant validity was determined via correlational analysis. Internal consistency was assessed using the Cronbach's alpha (α) coefficient, and the Composite Reliability (CR) was estimated. A total of 975 cancer patients participated in the study, with a mean age of 53.3 (SD = 13.0) years. Of these participants, 61.5 % were women. In CFA, five correlations between errors were included to fit the FACT-G to the sample (χ (2)/df = 8.611, CFI = .913, TLI = .902, RMSEA = .088). The model did not indicate invariant independent samples (Δχ(2): μ: p < .001, i: p < .958, Cov: p < .001, Res: p < .001). While there was adequate convergent validity for the physical well-being (AVE = .54) and social and family Well-being factors (AVE = .55), there was low convergent validity for the other factors. Reliability was adequate (CR = .76-.89 and α = .71-.82). Functional well-being, emotional well-being, and physical well-being were the factors that demonstrated a strong contribution to patients' health-related quality of life (β = -.99, .88, and .64, respectively). The FACT-G was found to be a valid and reliable assessment of health-related quality of life in a Brazilian sample of patients with cancer.
Cross-Cultural Applicability of the Montreal Cognitive Assessment (MoCA): A Systematic Review.
O'Driscoll, Ciarán; Shaikh, Madiha
2017-01-01
The Montreal Cognitive Assessment (MoCA) is widely used to screen for mild cognitive impairment (MCI). While there are many available versions, the cross-cultural validity of the assessment has not been explored sufficiently. We aimed to interrogate the validity of the MoCA in a cross-cultural context: in differentiating MCI from normal controls (NC); and identifying cut-offs and adjustments for age and education where possible. This review sourced a wide range of studies including case-control studies. In addition, we report findings for differentiating dementias from NC and MCI from dementias, however, these were not considered to be an appropriate use of the MoCA. The subject of the review assumes heterogeneity and therefore meta-analyses was not conducted. Quality ratings, forest plots of validated studies (sensitivity and specificity) with covariates (suggested cut-offs, age, education and country), and summary receiver operating characteristic curve are presented. The results showed a wide range in suggested cutoffs for MCI cross-culturally, with variability in levels of sensitivity and specificity ranging from low to high. Poor methodological rigor appears to have affected reported accuracy and validity of the MoCA. The review highlights the necessity for cross-cultural considerations when using the MoCA, and recognizing it as a screen and not a diagnostic tool. Appropriate cutoffs and point adjustments for education are suggested.
Cross-cultural adaptation of instruments assessing breastfeeding determinants: a multi-step approach
2014-01-01
Background Cross-cultural adaptation is a necessary process to effectively use existing instruments in other cultural and language settings. The process of cross-culturally adapting, including translation, of existing instruments is considered a critical set to establishing a meaningful instrument for use in another setting. Using a multi-step approach is considered best practice in achieving cultural and semantic equivalence of the adapted version. We aimed to ensure the content validity of our instruments in the cultural context of KwaZulu-Natal, South Africa. Methods The Iowa Infant Feeding Attitudes Scale, Breastfeeding Self-Efficacy Scale-Short Form and additional items comprise our consolidated instrument, which was cross-culturally adapted utilizing a multi-step approach during August 2012. Cross-cultural adaptation was achieved through steps to maintain content validity and attain semantic equivalence in the target version. Specifically, Lynn’s recommendation to apply an item-level content validity index score was followed. The revised instrument was translated and back-translated. To ensure semantic equivalence, Brislin’s back-translation approach was utilized followed by the committee review to address any discrepancies that emerged from translation. Results Our consolidated instrument was adapted to be culturally relevant and translated to yield more reliable and valid results for use in our larger research study to measure infant feeding determinants effectively in our target cultural context. Conclusions Undertaking rigorous steps to effectively ensure cross-cultural adaptation increases our confidence that the conclusions we make based on our self-report instrument(s) will be stronger. In this way, our aim to achieve strong cross-cultural adaptation of our consolidated instruments was achieved while also providing a clear framework for other researchers choosing to utilize existing instruments for work in other cultural, geographic and population settings. PMID:25285151
Cognitive-Motor Interference in an Ecologically Valid Street Crossing Scenario.
Janouch, Christin; Drescher, Uwe; Wechsler, Konstantin; Haeger, Mathias; Bock, Otmar; Voelcker-Rehage, Claudia
2018-01-01
Laboratory-based research revealed that gait involves higher cognitive processes, leading to performance impairments when executed with a concurrent loading task. Deficits are especially pronounced in older adults. Theoretical approaches like the multiple resource model highlight the role of task similarity and associated attention distribution problems. It has been shown that in cases where these distribution problems are perceived relevant to participant's risk of falls, older adults prioritize gait and posture over the concurrent loading task. Here we investigate whether findings on task similarity and task prioritization can be transferred to an ecologically valid scenario. Sixty-three younger adults (20-30 years of age) and 61 older adults (65-75 years of age) participated in a virtual street crossing simulation. The participants' task was to identify suitable gaps that would allow them to cross a simulated two way street safely. Therefore, participants walked on a manual treadmill that transferred their forward motion to forward displacements in a virtual city. The task was presented as a single task (crossing only) and as a multitask. In the multitask condition participants were asked, among others, to type in three digit numbers that were presented either visually or auditorily. We found that for both age groups, street crossing as well as typing performance suffered under multitasking conditions. Impairments were especially pronounced for older adults (e.g., longer crossing initiation phase, more missed opportunities). However, younger and older adults did not differ in the speed and success rate of crossing. Further, deficits were stronger in the visual compared to the auditory task modality for most parameters. Our findings conform to earlier studies that found an age-related decline in multitasking performance in less realistic scenarios. However, task similarity effects were inconsistent and question the validity of the multiple resource model within ecologically valid scenarios.
Individuals at high risk for suicide are categorically distinct from those at low risk.
Witte, Tracy K; Holm-Denoma, Jill M; Zuromski, Kelly L; Gauthier, Jami M; Ruscio, John
2017-04-01
Although suicide risk is often thought of as existing on a graded continuum, its latent structure (i.e., whether it is categorical or dimensional) has not been empirically determined. Knowledge about the latent structure of suicide risk holds implications for suicide risk assessments, targeted suicide interventions, and suicide research. Our objectives were to determine whether suicide risk can best be understood as a categorical (i.e., taxonic) or dimensional entity, and to validate the nature of any obtained taxon. We conducted taxometric analyses of cross-sectional, baseline data from 16 independent studies funded by the Military Suicide Research Consortium. Participants (N = 1,773) primarily consisted of military personnel, and most had a history of suicidal behavior. The Comparison Curve Fit Index values for MAMBAC (.85), MAXEIG (.77), and L-Mode (.62) all strongly supported categorical (i.e., taxonic) structure for suicide risk. Follow-up analyses comparing the taxon and complement groups revealed substantially larger effect sizes for the variables most conceptually similar to suicide risk compared with variables indicating general distress. Pending replication and establishment of the predictive validity of the taxon, our results suggest the need for a fundamental shift in suicide risk assessment, treatment, and research. Specifically, suicide risk assessments could be shortened without sacrificing validity, the most potent suicide interventions could be allocated to individuals in the high-risk group, and research should generally be conducted on individuals in the high-risk group. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Development and Validation of the Somatic Symptom Disorder-B Criteria Scale (SSD-12).
Toussaint, Anne; Murray, Alexandra M; Voigt, Katharina; Herzog, Annabel; Gierk, Benjamin; Kroenke, Kurt; Rief, Winfried; Henningsen, Peter; Löwe, Bernd
2016-01-01
To develop and validate a new self-report questionnaire for the assessment of the psychological features of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition somatic symptom disorder. The Somatic Symptom Disorder-B Criteria Scale (SSD-12) was developed in several steps from an initial pool of 98 items. The SSD-12 is composed of 12 items; each of the three psychological subcriteria is measured by four items. In a cross-sectional study, the SSD-12 was administered to 698 patients (65.8% female, mean [standard deviation] age = 38.79 [14.15] years) from a psychosomatic outpatient clinic. Item and scale characteristics as well as measures of reliability and validity were determined. The SSD-12 has good item characteristics and excellent reliability (Cronbach α = .95). Confirmatory factor analyses suggested that a three-factorial structure that reflects the three psychological criteria interpreted as cognitive, affective, and behavioral aspects (n = 663, Comparative Fit Index > 0.99, Tucker-Lewis Index > 0.99, Root Mean Square Error of Approximation = 0.06, 90% confidence interval = 0.01-0.08). SSD-12 total sum score was significantly associated with somatic symptom burden (r = 0.47, p < .001) and health anxiety (r = 0.71, p < .001), and moderately associated with general anxiety (r = 0.35, p < .001) and depressive symptoms (r = 0.22, p < .001). Patients with a higher SSD-12 psychological symptom burden reported higher general physical and mental health impairment and significantly higher health care use. The SSD-12 is the first self-report questionnaire that operationalizes the new psychological characteristics of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition somatic symptom disorder. Initial assessment indicates that the SSD-12 has sufficient reliability and validity to warrant further testing in both research and clinical settings.
Computer-aided Assessment of Regional Abdominal Fat with Food Residue Removal in CT
Makrogiannis, Sokratis; Caturegli, Giorgio; Davatzikos, Christos; Ferrucci, Luigi
2014-01-01
Rationale and Objectives Separate quantification of abdominal subcutaneous and visceral fat regions is essential to understand the role of regional adiposity as risk factor in epidemiological studies. Fat quantification is often based on computed tomography (CT) because fat density is distinct from other tissue densities in the abdomen. However, the presence of intestinal food residues with densities similar to fat may reduce fat quantification accuracy. We introduce an abdominal fat quantification method in CT with interest in food residue removal. Materials and Methods Total fat was identified in the feature space of Hounsfield units and divided into subcutaneous and visceral components using model-based segmentation. Regions of food residues were identified and removed from visceral fat using a machine learning method integrating intensity, texture, and spatial information. Cost-weighting and bagging techniques were investigated to address class imbalance. Results We validated our automated food residue removal technique against semimanual quantifications. Our feature selection experiments indicated that joint intensity and texture features produce the highest classification accuracy at 95%. We explored generalization capability using k-fold cross-validation and receiver operating characteristic (ROC) analysis with variable k. Losses in accuracy and area under ROC curve between maximum and minimum k were limited to 0.1% and 0.3%. We validated tissue segmentation against reference semimanual delineations. The Dice similarity scores were as high as 93.1 for subcutaneous fat and 85.6 for visceral fat. Conclusions Computer-aided regional abdominal fat quantification is a reliable computational tool for large-scale epidemiological studies. Our proposed intestinal food residue reduction scheme is an original contribution of this work. Validation experiments indicate very good accuracy and generalization capability. PMID:24119354
Computer-aided assessment of regional abdominal fat with food residue removal in CT.
Makrogiannis, Sokratis; Caturegli, Giorgio; Davatzikos, Christos; Ferrucci, Luigi
2013-11-01
Separate quantification of abdominal subcutaneous and visceral fat regions is essential to understand the role of regional adiposity as risk factor in epidemiological studies. Fat quantification is often based on computed tomography (CT) because fat density is distinct from other tissue densities in the abdomen. However, the presence of intestinal food residues with densities similar to fat may reduce fat quantification accuracy. We introduce an abdominal fat quantification method in CT with interest in food residue removal. Total fat was identified in the feature space of Hounsfield units and divided into subcutaneous and visceral components using model-based segmentation. Regions of food residues were identified and removed from visceral fat using a machine learning method integrating intensity, texture, and spatial information. Cost-weighting and bagging techniques were investigated to address class imbalance. We validated our automated food residue removal technique against semimanual quantifications. Our feature selection experiments indicated that joint intensity and texture features produce the highest classification accuracy at 95%. We explored generalization capability using k-fold cross-validation and receiver operating characteristic (ROC) analysis with variable k. Losses in accuracy and area under ROC curve between maximum and minimum k were limited to 0.1% and 0.3%. We validated tissue segmentation against reference semimanual delineations. The Dice similarity scores were as high as 93.1 for subcutaneous fat and 85.6 for visceral fat. Computer-aided regional abdominal fat quantification is a reliable computational tool for large-scale epidemiological studies. Our proposed intestinal food residue reduction scheme is an original contribution of this work. Validation experiments indicate very good accuracy and generalization capability. Published by Elsevier Inc.
29 CFR 1607.5 - General standards for validity studies.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 29 Labor 4 2010-07-01 2010-07-01 false General standards for validity studies. 1607.5 Section 1607... studies. A. Acceptable types of validity studies. For the purposes of satisfying these guidelines, users may rely upon criterion-related validity studies, content validity studies or construct validity...
Large-scale Cross-modality Search via Collective Matrix Factorization Hashing.
Ding, Guiguang; Guo, Yuchen; Zhou, Jile; Gao, Yue
2016-09-08
By transforming data into binary representation, i.e., Hashing, we can perform high-speed search with low storage cost, and thus Hashing has collected increasing research interest in the recent years. Recently, how to generate Hashcode for multimodal data (e.g., images with textual tags, documents with photos, etc) for large-scale cross-modality search (e.g., searching semantically related images in database for a document query) is an important research issue because of the fast growth of multimodal data in the Web. To address this issue, a novel framework for multimodal Hashing is proposed, termed as Collective Matrix Factorization Hashing (CMFH). The key idea of CMFH is to learn unified Hashcodes for different modalities of one multimodal instance in the shared latent semantic space in which different modalities can be effectively connected. Therefore, accurate cross-modality search is supported. Based on the general framework, we extend it in the unsupervised scenario where it tries to preserve the Euclidean structure, and in the supervised scenario where it fully exploits the label information of data. The corresponding theoretical analysis and the optimization algorithms are given. We conducted comprehensive experiments on three benchmark datasets for cross-modality search. The experimental results demonstrate that CMFH can significantly outperform several state-of-the-art cross-modality Hashing methods, which validates the effectiveness of the proposed CMFH.
Huang, Hui-Chuan; Shyu, Meei-Ling; Lin, Mei-Feng; Hu, Chaur-Jong; Chang, Chien-Hung; Lee, Hsin-Chien; Chi, Nai-Fang; Chang, Hsiu-Ju
2017-12-01
The objectives of this study were to develop a cross-cultural Chinese version of the Emotional and Social Dysfunction Questionnaire (ESDQ-C) and test its validity and reliability among Chinese-speaking stroke patients. Various methods were used to develop the ESDQ-C. A cross-sectional study was used to examine the validity and reliability of the developed questionnaire, which consists of 28 items belonging to six factors, anger, helplessness, emotional dyscontrol, indifference, inertia and fatigue, and euphoria. Satisfactory convergence and known-group validities were confirmed by significant correlations of the ESDQ-C with the Profile of Mood States-Short Form ( p < .05) and with the Hospital Anxiety and Depression Scale ( p < .05). The internal consistency was represented by Cronbach's alpha, which was .96 and .79 to .92 for the entire scale and subscales, respectively. Appropriate application of the ESDQ-C will be helpful to identify critical adjustment-related types of distress and patients who experience difficulty coping with such distress.
Rosen, Allyson; Weitlauf, Julie C
2015-01-01
A screening measure of capacity to consent can provide an efficient method of determining the appropriateness of including individuals from vulnerable patient populations in research, particularly in circumstances in which no caregiver is available to provide surrogate consent. Seaman et al. (2015) cross-validate a measure of capacity to consent to research developed by Jeste et al. (2007). They provide data on controls, caregivers, and patients with mild cognitive impairment and dementia. The study demonstrates the importance of validating measures across disorders with different domains of incapacity, as well as the need for timely and appropriate follow-up with potential participants who yield positive screens. Ultimately clinical measures need to adapt to the dimensional diagnostic approaches put forward in DSM 5. Integrative models of constructs, such as capacity to consent, will make this process more efficient by avoiding the need to test measures in each disorder. Until then, cross-validation studies, such as the work by Seaman et al. (2015) are critical.
Pilar Orive, Francisco Javier; Basabe Lozano, Jasone; López Zuñiga, Aurora; López Fernández, Yolanda M; Escudero Argaluza, Julene; Latour, Jos M
2017-11-03
Few validated surveys measuring parental satisfaction in the Paediatric Intensive Care Unit (PICU) are available, and none of them in Spanish language. The aim of this study is to translate and validate the questionnaire EMpowerment of PArents in THe Intensive Care (EMPATHIC). This questionnaire measures parental perceptions of paediatric intensive care-related satisfaction items in the Spanish language. A prospective cohort study was carried out using questionnaires completed by relatives of children (range 0-17 years old) admitted into a tertiary PICU. Inclusion criteria were a length of stay more than 24h, and a suitable understanding of Spanish language by parents or guardians. Exclusion criteria were re-admissions and deceased patients. The questionnaire was translated from English to Spanish language using a standardised procedure, after which it was used in a cross-sectional observational study was performed to confirm its validity and consistency. Reliability was estimated using Cronbach's α, and content validity using Spearman's correlation analysis. A total of 150 questionnaires were collected. A Cronbach's α was obtained for domains greater than 0.7, showing a high internal consistency from the questionnaire. Validity was measured by correlating 5 domains with 4 general satisfaction items, documenting an adequate correlation (Rs: 0.41-0.66, P<.05). The Spanish version of EMPHATIC 30 is a feasible, easy, and suitable tool in this specific environment, based on the results. EMPATHIC 30 is able to measure parental satisfaction, and may serve as a valid indicator to measure quality of care in Spanish PICUs. Copyright © 2017. Publicado por Elsevier España, S.L.U.
Reliability and validity of the Lithuanian Tinnitus Handicap Inventory.
Ulozienė, Ingrida; Balnytė, Renata; Alzbutienė, Giedrė; Arechvo, Irina; Vaitkus, Antanas; Šileikaitė, Milda; Šaferis, Viktoras; Ulozas, Virgilijus
2016-01-01
The aim of this study was to determine the reliability and validity of the Lithuanian version of the Tinnitus Handicap Inventory (THI), a self-report measure of perceived tinnitus handicap. A cross-sectional psychometric validation study was performed in the University Hospital. A total of 248 subjects reporting chronic tinnitus as their primary complaint or secondary to hearing loss were encluded in the study and filled in the Lithuanian version of THI. For assessment of construct validity a subgroup of 55 participants completed the Lithuanian version of the Hospital Anxiety and Depression Scale as a measure of self-perceived levels of anxiety and depression. Test-retest and internal consistency reliability as well as construct validity were calculated. The Lithuanian version of the THI and its subscales showed a robust internal consistency reliability (Cronbach's alpha=0.93) comparable to the original version. Statistically significant correlations were observed between the Lithuanian translation of the THI and the measures of self-perceived levels of anxiety and depression using HADS. Confirmatory factor analysis demonstrated that the three subscales of the THI Lithuanian version corresponded to three different factors, which strongly correlated between themselves. The results suggest that the Lithuanian version of THI maintains its original validity and may serve as reliable and valid measure of general tinnitus related distress that can be used in a clinical setting to quantify the impact of tinnitus on daily living. Copyright © 2016 The Lithuanian University of Health Sciences. Production and hosting by Elsevier Urban & Partner Sp. z o.o. All rights reserved.
Boonstra, Anne M; Schiphorst Preuper, Henrica R; Reneman, Michiel F; Posthumus, Jitze B; Stewart, Roy E
2008-06-01
To determine the reliability and concurrent validity of a visual analogue scale (VAS) for disability as a single-item instrument measuring disability in chronic pain patients was the objective of the study. For the reliability study a test-retest design and for the validity study a cross-sectional design was used. A general rehabilitation centre and a university rehabilitation centre was the setting for the study. The study population consisted of patients over 18 years of age, suffering from chronic musculoskeletal pain; 52 patients in the reliability study, 344 patients in the validity study. Main outcome measures were as follows. Reliability study: Spearman's correlation coefficients (rho values) of the test and retest data of the VAS for disability; validity study: rho values of the VAS disability scores with the scores on four domains of the Short-Form Health Survey (SF-36) and VAS pain scores, and with Roland-Morris Disability Questionnaire scores in chronic low back pain patients. Results were as follows: in the reliability study rho values varied from 0.60 to 0.77; and in the validity study rho values of VAS disability scores with SF-36 domain scores varied from 0.16 to 0.51, with Roland-Morris Disability Questionnaire scores from 0.38 to 0.43 and with VAS pain scores from 0.76 to 0.84. The conclusion of the study was that the reliability of the VAS for disability is moderate to good. Because of a weak correlation with other disability instruments and a strong correlation with the VAS for pain, however, its validity is questionable.
Validation of tungsten cross sections in the neutron energy region up to 100 keV
NASA Astrophysics Data System (ADS)
Pigni, Marco T.; Žerovnik, Gašper; Leal, Luiz. C.; Trkov, Andrej
2017-09-01
Following a series of recent cross section evaluations on tungsten isotopes performed at Oak Ridge National Laboratory (ORNL), this paper presents the validation work carried out to test the performance of the evaluated cross sections based on lead-slowing-down (LSD) benchmarks conducted in Grenoble. ORNL completed the resonance parameter evaluation of four tungsten isotopes - 182,183,184,186W - in August 2014 and submitted it as an ENDF-compatible file to be part of the next release of the ENDF/B-VIII.0 nuclear data library. The evaluations were performed with support from the US Nuclear Criticality Safety Program in an effort to provide improved tungsten cross section and covariance data for criticality safety sensitivity analyses. The validation analysis based on the LSD benchmarks showed an improved agreement with the experimental response when the ORNL tungsten evaluations were included in the ENDF/B-VII.1 library. Comparison with the results obtained with the JEFF-3.2 nuclear data library are also discussed.
Hasan, Hunaid; Hasan, Tasneem Fatema
2009-01-01
This cross-cultural study explored along with various personality factors the relationship between laughter and disease prevalence. Previous studies have only determined the effect of laughter on various health dimensions, whereas, this study quantified the level of laughter that was beneficial or detrimental to health. There were a total of 730 participants between the ages of eighteen and thirty-nine years. 366 participants were from Aurangabad, India (AUR), and 364 participants were from Mississauga, Canada (MISS). The participants were provided a survey assessing demographics, laughter, lifestyle, subjective well-being, life satisfaction, emotional well-being and health dimensions. In AUR, a beneficial effect of laughter was mediated through moderate levels (level two) of laughter, whereas both low (level one) and high (level three) levels had no effect. Similarly, in MISS, the beneficial effect was mediated through level two, but a negative effect was also seen at level three. This could be attributable to a higher prevalence of bronchial asthma in western countries. Laughter was associated with emotional well-being in MISS and life satisfaction in AUR, providing cross cultural models to describe the interactions between laughter and disease. This study validated the correlation between emotional well-being and life satisfaction, with a stronger correlation seen in MISS, suggesting that individualists rely more on their emotional well-being to judge their life satisfaction. In conclusion, there is a benefit to clinicians to incorporate laughter history into their general medical history taking. Future research should consider developing mechanisms to explain the effects of level two, determine specific systemic effects and obtain more samples to generalize the cross cultural differences. PMID:19652724
Hasan, Hunaid; Hasan, Tasneem Fatema
2009-07-28
This cross-cultural study explored along with various personality factors the relationship between laughter and disease prevalence. Previous studies have only determined the effect of laughter on various health dimensions, whereas, this study quantified the level of laughter that was beneficial or detrimental to health. There were a total of 730 participants between the ages of eighteen and thirty-nine years. 366 participants were from Aurangabad, India (AUR), and 364 participants were from Mississauga, Canada (MISS). The participants were provided a survey assessing demographics, laughter, lifestyle, subjective well-being, life satisfaction, emotional well-being and health dimensions. In AUR, a beneficial effect of laughter was mediated through moderate levels (level two) of laughter, whereas both low (level one) and high (level three) levels had no effect. Similarly, in MISS, the beneficial effect was mediated through level two, but a negative effect was also seen at level three. This could be attributable to a higher prevalence of bronchial asthma in western countries. Laughter was associated with emotional well-being in MISS and life satisfaction in AUR, providing cross cultural models to describe the interactions between laughter and disease. This study validated the correlation between emotional well-being and life satisfaction, with a stronger correlation seen in MISS, suggesting that individualists rely more on their emotional well-being to judge their life satisfaction. In conclusion, there is a benefit to clinicians to incorporate laughter history into their general medical history taking. Future research should consider developing mechanisms to explain the effects of level two, determine specific systemic effects and obtain more samples to generalize the cross cultural differences.
Rimondini, Michela; Mazzi, Maria Angela; Deveugele, Myriam; Bensing, Jozien M
2015-12-14
The evidence that inspires and fosters communication skills, teaching programmes and clinical recommendations are often based on national studies which assume, implicitly, that patients' preferences towards doctors' communication style are not significantly affected by their cultural background. The cross-cultural validity of national results has been recognized as a potential limitation on how generally applicable they are in a wider context. Using 35 country-specific focus group discussions from four European countries, the aim of the present study is to test whether or not national cultures influence lay people's preferences towards doctors' style of communication. Lay people preferences on doctor's communication style have been collected in Belgium, the Netherlands, the United Kingdom and Italy. Each centre organized between eight and nine focus groups, where participants (n = 259) were asked to comment on a video of a simulated medical interview. The discussions were audiotaped, transcribed and coded using a common framework (Guliver Coding System) that allowed for the identification of different themes. The frequency distribution of the topics discussed highlights lay people's generally positive views towards most part of doctors interventions. The regression model applied to the Guliver categories highlighted slight national differences and the existence of a cross-cultural appreciation, in particular, of five types of intervention: Doctors attitudes (both Task-Oriented and Affective/Emotional), Summarizing, Structuring and Providing solution. Lay panels valued doctors' communication style in a similar manner in the countries selected. This highlights the existence of a common background, which in the process of internationalization of heath care, might foster the implementation of cross-national teaching programmes and clinical guidelines.
Mills, Tamara L; Holm, Margo B; Schmeler, Mark
2007-01-01
The purpose of this study was to establish the test-retest reliability and content validity of an outcomes tool designed to measure the effectiveness of seating-mobility interventions on the functional performance of individuals who use wheelchairs or scooters as their primary seating-mobility device. The instrument, Functioning Everyday With a Wheelchair (FEW), is a questionnaire designed to measure perceived user function related to wheelchair/scooter use. Using consumer-generated items, FEW Beta Version 1.0 was developed and test-retest reliability was established. Cross-validation of FEW Beta Version 1.0 was then carried out with five samples of seating-mobility users to establish content validity. Based on the content validity study, FEW Version 2.0 was developed and administered to seating-mobility consumers to examine its test-retest reliability. FEW Beta Version 1.0 yielded an intraclass correlation coefficient (ICC) Model (3,k) of .92, p < .001, and the content validity results revealed that FEW Beta Version 1.0 captured 55% of seating-mobility goals reported by consumers across five samples. FEW Version 2.0 yielded ICC(3,k) = .86, p < .001, and captured 98.5% of consumers' seating-mobility goals. The cross-validation study identified new categories of seating-mobility goals for inclusion in FEW Version 2.0, and the content validity of FEW Version 2.0 was confirmed. FEW Beta Version 1.0 and FEW Version 2.0 were highly stable in their measurement of participants' seating-mobility goals over a 1-week interval.
Shafeei, Asrin; Mokhtarinia, Hamid Reza; Maleki-Ghahfarokhi, Azam; Piri, Leila
2017-08-01
Observational study. To cross-culturally translate the Orebro Musculoskeletal Pain Screening Questionnaire (OMPQ) into Persian and then evaluate its psychometric properties (reliability, validity, ceiling, and flooring effects). To the authors' knowledge, prior to this study there has been no validated instrument to screen the risk of chronicity in Persian-speaking patients with low back pain (LBP) in Iran. The OMPQ was specifically developed as a self-administered screening tool for assessing the risk of LBP chronicity. The forward-backward translation method was used for the translation and cross-cultural adaptation of the original questionnaire. In total, 202 patients with subacute LBP completed the OMPQ and the pain disability questionnaire (PDQ), which was used to assess convergent validity. 62 patients completed the OMPQ a week later as a retest. Slight changes were made to the OMPQ during the translation/cultural adaptation process; face validity of the Persian version was obtained. The Persian OMPQ showed excellent test-retest reliability (intraclass correlation coefficient=0.89). Its internal consistency was 0.71, and its convergent validity was confirmed by good correlation coefficient between the OMPQ and PDQ total scores ( r =0.72, p <0.05). No ceiling or floor effects were observed. The Persian version of the OMPQ is acceptable for the target society in terms of face validity, construct validity, reliability, and consistency. It is therefore considered a useful instrument for screening Iranian patients with LBP.
Validity of the FACT-H&N (v 4.0) among Malaysian oral cancer patients.
Doss, J G; Thomson, W M; Drummond, B K; Raja Latifah, R J
2011-07-01
To assess the cross-sectional construct validity of the Malay-translated and cross-culturally adapted FACT-H&N (v 4.0) for discriminative use in a sample of Malaysian oral cancer patients. A cross-sectional study of adults newly diagnosed with oral cancer. HRQOL data were collected using the FACT-H&N (v 4.0), a global question and a supplementary set of eight questions ('MAQ') obtained earlier in pilot work. Of the 76 participants (61.8% female; 23.7% younger than 50), most (96.1%) had oral squamous cell carcinoma; two-thirds were in Stages III or IV. At baseline, patients' mean FACT summary (FACT-G, FACT-H&N, FACT-H&N TOI, and FHNSI) and subscale (pwb, swb, ewb, fwb, and hnsc) scores were towards the higher end of the range. Equal proportions (36.8%) rated their overall HRQOL as 'good' or 'average'; fewer than one-quarter rated it as 'poor', and only two as 'very good'. All six FACT summary and most subscales had moderate-to-good internal consistency. For all summary scales, those with 'very poor/poor' self-rated HRQOL differed significantly from the 'good/very good' group. All FACT summary scales correlated strongly (r>0.75). Summary scales showed convergent validity (r>0.90) but little discriminant validity. The discriminant validity of the FHNSI improved with the addition of the MAQ. The FACT-H&N summary scales and most subscales demonstrated acceptable cross-sectional construct validity, reliability and discriminative ability, and thus appear appropriate for further use among Malaysian oral cancer patients. Copyright © 2011 Elsevier Ltd. All rights reserved.
Initial Reliability and Validity of the Perceived Social Competence Scale
ERIC Educational Resources Information Center
Anderson-Butcher, Dawn; Iachini, Aidyn L.; Amorose, Anthony J.
2008-01-01
Objective: This study describes the development and validation of a perceived social competence scale that social workers can easily use to assess children's and youth's social competence. Method: Exploratory and confirmatory factor analyses were conducted on a calibration and a cross-validation sample of youth. Predictive validity was also…
Linear Models for Field Trials, Smoothing, and Cross-Validation.
1984-01-01
TSR-2?79 UNCLASSIFIED DRAG29-80-C-9841 F /G 12/ 1 NL EhhiuEammhhihhhihhiu iI. U.. III1 11111- 1.2 11111 L.1g 1111IL25 11111J.4 I 6 MICROCOPY RESOLUTION...0 (2.2) where (de Hoog , Speed and Williams, 1985) 60 - 1 V-IR( RT- -1R)-RTV- 1 + (2.3) = I - HI - P R)V(I - P R (23 Here I is the n x n identity matrix...Here the model would be yi = (t ) + ni and one possible penalty function is f (&"(t)) 2dt + E2 1 Natural points of departure for generalizing the least
Analysis of a boron-carbide-drum-controlled critical reactor experiment
NASA Technical Reports Server (NTRS)
Mayo, W. T.
1972-01-01
In order to validate methods and cross sections used in the neutronic design of compact fast-spectrum reactors for generating electric power in space, an analysis of a boron-carbide-drum-controlled critical reactor was made. For this reactor the transport analysis gave generally satisfactory results. The calculated multiplication factor for the most detailed calculation was only 0.7-percent Delta k too high. Calculated reactivity worth of the control drums was $11.61 compared to measurements of $11.58 by the inverse kinetics methods and $11.98 by the inverse counting method. Calculated radial and axial power distributions were in good agreement with experiment.
Cerin, Ester; Sit, Cindy Hp; Cheung, Man-Chin; Ho, Sai-Yin; Lee, Lok-Chun Janet; Chan, Wai-Man
2010-11-25
The effects of the built environment on walking in seniors have not been studied in an Asian context. To examine these effects, valid and reliable measures are needed. The aim of this study was to develop and validate a questionnaire of perceived neighborhood characteristics related to walking appropriate for Chinese seniors (Neighborhood Environment Walkability Scale for Chinese Seniors, NEWS-CS). It was based on the Neighborhood Environment Walkability Scale - Abbreviated (NEWS-A), a validated measure of perceived built environment developed in the USA for adults. A secondary study aim was to establish the generalizability of the NEWS-A to an Asian high-density urban context and a different age group. A multidisciplinary panel of experts adapted the original NEWS-A to reflect the built environment of Hong Kong and needs of seniors. The translated instrument was pre-tested on a sample of 50 Chinese-speaking senior residents (65+ years). The final version of the NEWS-CS was interviewer-administered to 484 seniors residing in four selected Hong Kong districts varying in walkability and socio-economic status. Ninety-two participants completed the questionnaire on two separate occasions, 2-3 weeks apart. Test-rest reliability indices were estimated for each item and subscale of the NEWS-CS. Confirmatory factor analysis was used to develop the measurement model of the NEWS-CS and cross-validate that of the NEWS-A. The final version of the NEWS-CS consisted of 14 subscales and four single items (76 items). Test-retest reliability was moderate to good (ICC > 50 or % agreement > 60) except for four items measuring distance to destinations. The originally-proposed measurement models of the NEWS-A and NEWS-CS required 2-3 theoretically-justifiable modifications to fit the data well. The NEWS-CS possesses sufficient levels of reliability and factorial validity to be used for measuring perceived neighborhood environment in Chinese seniors. Further work is needed to assess its construct validity and generalizability to other Asian locations. In general, the measurement model of the original NEWS-A was generalizable to this study context, supporting the feasibility of cross-country and age-group comparisons of the effect of the neighborhood environment on walking using the NEWS-A as a tool to measure the perceived built environment.
ERIC Educational Resources Information Center
Morris, Cody E.; Owens, Scott G.; Waddell, Dwight E.; Bass, Martha A.; Bentley, John P.; Loftin, Mark
2014-01-01
An equation published by Loftin, Waddell, Robinson, and Owens (2010) was cross-validated using ten normal-weight walkers, ten overweight walkers, and ten distance runners. Energy expenditure was measured at preferred walking (normal-weight walker and overweight walkers) or running pace (distance runners) for 5 min and corrected to a mile. Energy…
ERIC Educational Resources Information Center
Pecorella, Patricia A.; Bowers, David G.
Multiple regression in a double cross-validated design was used to predict two performance measures (total variable expense and absence rate) by multi-month period in five industrial firms. The regressions do cross-validate, and produce multiple coefficients which display both concurrent and predictive effects, peaking 18 months to two years…
ERIC Educational Resources Information Center
Teo, Timothy
2010-01-01
Purpose: The purpose of this paper is to assess the cross-cultural validity of the technology acceptance measure for pre-service teachers (TAMPST) on a Malaysian sample. Design/methodology/approach: A total of 193 pre-service teachers from a Malaysian university completed a survey questionnaire measuring their responses to five constructs in the…
He, S L; Wang, J H; Ji, P
2018-03-01
To validate the Pain Resilience Scale (PRS) for use in Chinese patients with temporomandibular disorders (TMD) pain. According to international guidelines, the original PRS was first translated and cross-culturally adapted to formulate the Chinese version of PRS (PRS-C). A total of 152 patients with TMD pain were recruited to complete series of questionnaires. Reliability of the PRS-C was investigated using internal consistency and test-retest reliability. Validity of the PRS-C was calculated using cross-cultural validity and convergent validity. Cross-cultural validity was evaluated by examining the confirmatory factor analysis (CFA). And convergent validity was examined through correlating the PRS-C scores with scores of 2 commonly used pain-related measures (the Connor-Davidson Resilience Scale [CD-RISC] and the Tampa Scale for Kinesiophobia for Temporomandibular Disorders [TSK-TMD]). The PRS-C had a high internal consistency (Cronbach's alpha = 0.92) and good test-retest reliability (intra-class correlation coefficient [ICC] = 0.81). The CFA supported a 2-factor model for the PRS-C with acceptable fit to the data. The fit indices were chi-square/DF = 2.21, GFI = 0.91, TLI = 0.97, CFI = 0.98 and RMSEA = 0.08. As regards convergent validity, the PRS-C evidenced moderate-to-good relationships with the CD-RISC and the TSK-TMD. The PRS-C shows good psychometric properties and could be considered as a reliable and valid measure to evaluate pain-related resilience in patients with TMD pain. © 2017 John Wiley & Sons Ltd.
Measuring Nigrescence Attitudes in School-Aged Adolescents
ERIC Educational Resources Information Center
Gardner-Kitt, Donna L.; Worrell, Frank C.
2007-01-01
In this study, we examined the reliability and validity of Cross Racial Identity Scale (CRIS; Vandiver, B. J., Cross Jr., W. E., Fhagen-Smith, P. E., Worrell, F. C., Swim, J. K., & Caldwell, L. D. (2000). "The Cross Racial Identity Scale." Unpublished scale; Worrell, F. C., Vandiver, B. J., & Cross Jr., W. E., (2004). "The Cross Racial Identity…
Kaux, Jean-François; Delvaux, François; Schaus, Jean; Demoulin, Christophe; Locquet, Médéa; Buckinx, Fanny; Beaudart, Charlotte; Dardenne, Nadia; Van Beveren, Julien; Croisier, Jean-Louis; Forthomme, Bénédicte; Bruyère, Olivier
Translation and validation of algo-functional questionnaire. The lateral elbow tendinopathy is a common injury in tennis players and physical workers. The Patient-Rated Tennis Elbow Evaluation (PRTEE) Questionnaire was specifically designed to measure pain and functional limitations in patients with lateral epicondylitis (tennis elbow). First developed in English, this questionnaire has since been translated into several languages. The aims of the study were to translate and cross-culturally adapt the PRTEE questionnaire into French and to evaluate the reliability and validity of this translated version of the questionnaire (PRTEE-F). The PRTEE was translated and cross-culturally adapted into French according to international guidelines. To assess the reliability and validity of the PRTEE-F, 115 participants were asked twice to fill in the PRTEE-F, and once the Disabilities of Arm, Shoulder and Hand Questionnaire (DASH) and the Short Form Health Survey (SF-36). Internal consistency (using Cronbach's alpha), test-retest reliability (using intraclass correlation coefficient (ICC), standard error of measurement and minimal detectable change), and convergent and divergent validity (using the Spearman's correlation coefficients respectively with the DASH and with some subscales of the SF-36) were assessed. The PRTEE was translated into French without any problems. PRTEE-F showed a good test-retest reliability for the overall score (ICC 0.86) and for each item (ICC 0.8-0.96) and a high internal consistency (Cronbach's alpha = 0.98). The correlation analyses revealed high correlation coefficients between PRTEE-F and DASH (convergent validity) and, as expected, a low or moderate correlation with the divergent subscales of the SF-36 (discriminant validity). There was no floor or ceiling effect. The PRTEE questionnaire was successfully cross-culturally adapted into French. The PRTEE-F is reliable and valid for evaluating French-speaking patients with lateral elbow tendinopathy. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.
Shape Optimization by Bayesian-Validated Computer-Simulation Surrogates
NASA Technical Reports Server (NTRS)
Patera, Anthony T.
1997-01-01
A nonparametric-validated, surrogate approach to optimization has been applied to the computational optimization of eddy-promoter heat exchangers and to the experimental optimization of a multielement airfoil. In addition to the baseline surrogate framework, a surrogate-Pareto framework has been applied to the two-criteria, eddy-promoter design problem. The Pareto analysis improves the predictability of the surrogate results, preserves generality, and provides a means to rapidly determine design trade-offs. Significant contributions have been made in the geometric description used for the eddy-promoter inclusions as well as to the surrogate framework itself. A level-set based, geometric description has been developed to define the shape of the eddy-promoter inclusions. The level-set technique allows for topology changes (from single-body,eddy-promoter configurations to two-body configurations) without requiring any additional logic. The continuity of the output responses for input variations that cross the boundary between topologies has been demonstrated. Input-output continuity is required for the straightforward application of surrogate techniques in which simplified, interpolative models are fitted through a construction set of data. The surrogate framework developed previously has been extended in a number of ways. First, the formulation for a general, two-output, two-performance metric problem is presented. Surrogates are constructed and validated for the outputs. The performance metrics can be functions of both outputs, as well as explicitly of the inputs, and serve to characterize the design preferences. By segregating the outputs and the performance metrics, an additional level of flexibility is provided to the designer. The validated outputs can be used in future design studies and the error estimates provided by the output validation step still apply, and require no additional appeals to the expensive analysis. Second, a candidate-based a posteriori error analysis capability has been developed which provides probabilistic error estimates on the true performance for a design randomly selected near the surrogate-predicted optimal design.
ARDAKANI, Abolfazl; SEGHATOLESLAM, Tahereh; HABIL, Hussain; JAMEEI, Fahimeh; RASHID, Rusdi; ZAHIRODIN, Alireza; MOTLAQ, Farid; MASJIDI ARANI, Abbas
2016-01-01
Background: Given that validity is the baseline of psychological assessments, there is a need to provide evidence-based data for construct validity of such scales to advance the clinicians for evaluating psychiatric morbidity in psychiatric and psychosomatic setting. Methods: This comparative cross-sectional study aimed to investigate the construct validity of the Malaysian version of the GHQ-28 and the SCL-90-R. The sample comprised 660 individuals including diabetics, drug dependents, and normal population. The research scales were administered to the participants. Convergent and discriminant validity of both scales were investigated by Confirmatory Factor Analysis (CFA) using AMOS. The Pearson correlation coefficient was utilized to obtain the relationship between the two scales. Results: The internal consistency of the GHQ-28 and SCL-90-R were highly acceptable, and confirmatory factor analysis confirmed the convergent validity of both scales. The results of this study revealed that the construct validity of GHQ-28 was acceptable, whereas discriminant validity of SCL-90-R was not adequate. According to Pearson correlation coefficient the relationships between three common subscales of the GHQ-28 and SCL-90-R were significantly positive; somatization (r=0.671, P<0.01), Anxiety (r=0.728, P<0.01), and Depression (r=0.660, P <0.01). Conclusions: This study replicated the construct of the Malaysian version of GHQ-28, yet failed to support the nine-factor structure of the SCL-90-R. Therefore, multidimensionality of the SCL-90-R as clinical purposes is questionable, and it may be a better unitary measure for assessing and screening mental disorders. Further research need to be carried out to prove this finding. PMID:27252914
Yen, Po-Yin; Sousa, Karen H; Bakken, Suzanne
2014-01-01
Background In a previous study, we developed the Health Information Technology Usability Evaluation Scale (Health-ITUES), which is designed to support customization at the item level. Such customization matches the specific tasks/expectations of a health IT system while retaining comparability at the construct level, and provides evidence of its factorial validity and internal consistency reliability through exploratory factor analysis. Objective In this study, we advanced the development of Health-ITUES to examine its construct validity and predictive validity. Methods The health IT system studied was a web-based communication system that supported nurse staffing and scheduling. Using Health-ITUES, we conducted a cross-sectional study to evaluate users’ perception toward the web-based communication system after system implementation. We examined Health-ITUES's construct validity through first and second order confirmatory factor analysis (CFA), and its predictive validity via structural equation modeling (SEM). Results The sample comprised 541 staff nurses in two healthcare organizations. The CFA (n=165) showed that a general usability factor accounted for 78.1%, 93.4%, 51.0%, and 39.9% of the explained variance in ‘Quality of Work Life’, ‘Perceived Usefulness’, ‘Perceived Ease of Use’, and ‘User Control’, respectively. The SEM (n=541) supported the predictive validity of Health-ITUES, explaining 64% of the variance in intention for system use. Conclusions The results of CFA and SEM provide additional evidence for the construct and predictive validity of Health-ITUES. The customizability of Health-ITUES has the potential to support comparisons at the construct level, while allowing variation at the item level. We also illustrate application of Health-ITUES across stages of system development. PMID:24567081
Baldwin, Carol M.; Choi, Myunghan; McClain, Darya Bonds; Celaya, Alma; Quan, Stuart F.
2012-01-01
Study Objectives: To translate, back-translate and cross-language validate (English/Spanish) the Sleep Heart Health Study Sleep Habits Questionnaire for use with Spanish-speakers in clinical and research settings. Methods: Following rigorous translation and back-translation, this cross-sectional cross-language validation study recruited bilingual participants from academic, clinic, and community-based settings (N = 50; 52% women; mean age 38.8 ± 12 years; 90% of Mexican heritage). Participants completed English and Spanish versions of the Sleep Habits Questionnaire, the Epworth Sleepiness Scale, and the Acculturation Rating Scale for Mexican Americans II one week apart in randomized order. Psychometric properties were assessed, including internal consistency, convergent validity, scale equivalence, language version intercorrelations, and exploratory factor analysis using PASW (Version18) software. Grade level readability of the sleep measure was evaluated. Results: All sleep categories (duration, snoring, apnea, insomnia symptoms, other sleep symptoms, sleep disruptors, restless legs syndrome) showed Cronbach α, Spearman-Brown coefficients and intercorrelations ≥ 0.700, suggesting robust internal consistency, correlation, and agreement between language versions. The Epworth correlated significantly with snoring, apnea, sleep symptoms, restless legs, and sleep disruptors) on both versions, supporting convergent validity. Items loaded on 4 factors accounted for 68% and 67% of the variance on the English and Spanish versions, respectively. Conclusions: The Spanish-language Sleep Habits Questionnaire demonstrates conceptual and content equivalency. It has appropriate measurement properties and should be useful for assessing sleep health in community-based clinics and intervention studies among Spanish-speaking Mexican Americans. Both language versions showed readability at the fifth grade level. Further testing is needed with larger samples. Citation: Baldwin CM; Choi M; McClain DB; Celaya A; Quan SF. Spanish translation and cross-language validation of a Sleep Habits Questionnaire for use in clinical and research settings. J Clin Sleep Med 2012;8(2):137-146. PMID:22505858
Spatio-temporal modeling of chronic PM 10 exposure for the Nurses' Health Study
NASA Astrophysics Data System (ADS)
Yanosky, Jeff D.; Paciorek, Christopher J.; Schwartz, Joel; Laden, Francine; Puett, Robin; Suh, Helen H.
2008-06-01
Chronic epidemiological studies of airborne particulate matter (PM) have typically characterized the chronic PM exposures of their study populations using city- or county-wide ambient concentrations, which limit the studies to areas where nearby monitoring data are available and which ignore within-city spatial gradients in ambient PM concentrations. To provide more spatially refined and precise chronic exposure measures, we used a Geographic Information System (GIS)-based spatial smoothing model to predict monthly outdoor PM10 concentrations in the northeastern and midwestern United States. This model included monthly smooth spatial terms and smooth regression terms of GIS-derived and meteorological predictors. Using cross-validation and other pre-specified selection criteria, terms for distance to road by road class, urban land use, block group and county population density, point- and area-source PM10 emissions, elevation, wind speed, and precipitation were found to be important determinants of PM10 concentrations and were included in the final model. Final model performance was strong (cross-validation R2=0.62), with little bias (-0.4 μg m-3) and high precision (6.4 μg m-3). The final model (with monthly spatial terms) performed better than a model with seasonal spatial terms (cross-validation R2=0.54). The addition of GIS-derived and meteorological predictors improved predictive performance over spatial smoothing (cross-validation R2=0.51) or inverse distance weighted interpolation (cross-validation R2=0.29) methods alone and increased the spatial resolution of predictions. The model performed well in both rural and urban areas, across seasons, and across the entire time period. The strong model performance demonstrates its suitability as a means to estimate individual-specific chronic PM10 exposures for large populations.
Schadl, Kornél; Vassar, Rachel; Cahill-Rowley, Katelyn; Yeom, Kristin W; Stevenson, David K; Rose, Jessica
2018-01-01
Advanced neuroimaging and computational methods offer opportunities for more accurate prognosis. We hypothesized that near-term regional white matter (WM) microstructure, assessed on diffusion tensor imaging (DTI), using exhaustive feature selection with cross-validation would predict neurodevelopment in preterm children. Near-term MRI and DTI obtained at 36.6 ± 1.8 weeks postmenstrual age in 66 very-low-birth-weight preterm neonates were assessed. 60/66 had follow-up neurodevelopmental evaluation with Bayley Scales of Infant-Toddler Development, 3rd-edition (BSID-III) at 18-22 months. Linear models with exhaustive feature selection and leave-one-out cross-validation computed based on DTI identified sets of three brain regions most predictive of cognitive and motor function; logistic regression models were computed to classify high-risk infants scoring one standard deviation below mean. Cognitive impairment was predicted (100% sensitivity, 100% specificity; AUC = 1) by near-term right middle-temporal gyrus MD, right cingulate-cingulum MD, left caudate MD. Motor impairment was predicted (90% sensitivity, 86% specificity; AUC = 0.912) by left precuneus FA, right superior occipital gyrus MD, right hippocampus FA. Cognitive score variance was explained (29.6%, cross-validated Rˆ2 = 0.296) by left posterior-limb-of-internal-capsule MD, Genu RD, right fusiform gyrus AD. Motor score variance was explained (31.7%, cross-validated Rˆ2 = 0.317) by left posterior-limb-of-internal-capsule MD, right parahippocampal gyrus AD, right middle-temporal gyrus AD. Search in large DTI feature space more accurately identified neonatal neuroimaging correlates of neurodevelopment.
Validating LES for Jet Aeroacoustics
NASA Technical Reports Server (NTRS)
Bridges, James; Wernet, Mark P.
2011-01-01
Engineers charged with making jet aircraft quieter have long dreamed of being able to see exactly how turbulent eddies produce sound and this dream is now coming true with the advent of large eddy simulation (LES). Two obvious challenges remain: validating the LES codes at the resolution required to see the fluid-acoustic coupling, and the interpretation of the massive datasets that are produced. This paper addresses the former, the use of advanced experimental techniques such as particle image velocimetry (PIV) and Raman and Rayleigh scattering, to validate the computer codes and procedures used to create LES solutions. This paper argues that the issue of accuracy of the experimental measurements be addressed by cross-facility and cross-disciplinary examination of modern datasets along with increased reporting of internal quality checks in PIV analysis. Further, it argues that the appropriate validation metrics for aeroacoustic applications are increasingly complicated statistics that have been shown in aeroacoustic theory to be critical to flow-generated sound, such as two-point space-time velocity correlations. A brief review of data sources available is presented along with examples illustrating cross-facility and internal quality checks required of the data before it should be accepted for validation of LES.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chapman, Bryan Scott; Gough, Sean T.
This report documents a validation of the MCNP6 Version 1.0 computer code on the high performance computing platform Moonlight, for operations at Los Alamos National Laboratory (LANL) that involve plutonium metals, oxides, and solutions. The validation is conducted using the ENDF/B-VII.1 continuous energy group cross section library at room temperature. The results are for use by nuclear criticality safety personnel in performing analysis and evaluation of various facility activities involving plutonium materials.
1989-04-20
International business Machines Corporati,:i IBM Development System for the Ada Language, CMS/MVS Ada Cross Compiler, Version 2.1.1, Wright-Patterson AFB, IBM...VALIDATION SUMMARY REPORT: Certificate Number: 890420W1.10075 International Business Machines Corporation IBM Development System for the Ada Language CMS...command scripts provided by International Business Machines Corporation and reviewed by the validation team. The compiler was tested using all default
van der Linden, Meta; Hooghe, Marc; de Vroome, Thomas; Van Laar, Colette
2017-01-01
The aim of this study is twofold. First, we expand on the literature by testing whether generalized trust is negatively related to anti-immigrant sentiments in Europe. Second, we examine to what extent the relation between generalized trust and anti-immigrant sentiments is dependent upon cross-group friendships. We apply multilevel linear regression modeling to representative survey data enriched with levels of ethnic diversity covering 21 European countries. Results show that both generalized trust and cross-group friendship are negatively related to anti-immigrant sentiments. However, there is a negligible positive relation between generalized trust and cross-group friendship (r = .10), and we can clearly observe that they operate independently from one another. Hence, trusting actors are not more likely to form more cross-group friendships, and cross-group friendship do not lead to the development of more generalized trust. Instead, the findings show that generalized trust leads immigrants too to be included in the radius of trusted others and, as a consequence, the benign effects of generalized trust apply to them as well. We conclude that the strength of generalized trust is a form of generalization, beyond the confines of individual variations in intergroup experiences. PMID:28481925
van der Linden, Meta; Hooghe, Marc; de Vroome, Thomas; Van Laar, Colette
2017-01-01
The aim of this study is twofold. First, we expand on the literature by testing whether generalized trust is negatively related to anti-immigrant sentiments in Europe. Second, we examine to what extent the relation between generalized trust and anti-immigrant sentiments is dependent upon cross-group friendships. We apply multilevel linear regression modeling to representative survey data enriched with levels of ethnic diversity covering 21 European countries. Results show that both generalized trust and cross-group friendship are negatively related to anti-immigrant sentiments. However, there is a negligible positive relation between generalized trust and cross-group friendship (r = .10), and we can clearly observe that they operate independently from one another. Hence, trusting actors are not more likely to form more cross-group friendships, and cross-group friendship do not lead to the development of more generalized trust. Instead, the findings show that generalized trust leads immigrants too to be included in the radius of trusted others and, as a consequence, the benign effects of generalized trust apply to them as well. We conclude that the strength of generalized trust is a form of generalization, beyond the confines of individual variations in intergroup experiences.
Absorption in Sport: A Cross-Validation Study
Koehn, Stefan; Stavrou, Nektarios A. M.; Cogley, Jeremy; Morris, Tony; Mosek, Erez; Watt, Anthony P.
2017-01-01
Absorption has been identified as readiness for experiences of deep involvement in the task. Conceptually, absorption is a key psychological construct, incorporating experiential, cognitive, and motivational components. Although, no operationalization of the construct has been provided to facilitate research in this area, the purpose of this research was the development and examination of the psychometric properties of a sport-specific measure of absorption that evolved from the use of the modified Tellegen Absorption Scale (MODTAS; Jamieson, 2005) in mainstream psychology. The study aimed to provide evidence of the psychometric properties, reliability, and validity of the Measure of Absorption in Sport Contexts (MASCs). The psychometric examination included a calibration sample from Scotland and a cross-validation sample from Australia using a cross-sectional design. The item pool was developed based on existing items from the modified Tellegen Absorption Scale (Jamieson, 2005). The MODTAS items were reworded and translated into a sport context. The Scottish sample consisted of 292 participants and the Australian sample of 314 participants. Congeneric model testing and confirmatory factor analysis for both samples and multi-group invariance testing across samples was used. In the cross-validation sample the MASC subscales showed acceptable internal consistency and construct reliability (≥0.70). Excellent fit indices were found for the final 18-item, six-factor measure in the cross-validation sample, χ(120)2 = 197.486, p < 0.001; CFI = 0.957; TLI = 0.945; RMSEA = 0.045; SRMR = 0.044. Multi-group invariance testing revealed no differences in item meaning, except for two items. The MASC and the Dispositional Flow Scale-2 showed moderate-to-strong positive correlations in both samples, r = 0.38, p < 0.001 and r = 0.42, p < 0.001, supporting the external validity of the MASC. This article provides initial evidence in support of the psychometric properties, reliability, and validity of the sport-specific measure of absorption. The MASC provides rich research opportunities in sport psychology that can enhance the theoretical understanding between absorption and related constructs and facilitate future intervention studies. PMID:28883802
Development and Validation of a Unidimensional Maltreatment Scale in the Add Health Data Set
ERIC Educational Resources Information Center
Marszalek, Jacob M.; Hamilton, Jessica L.
2012-01-01
Four maltreatment items were examined from Wave III (N = 13,516) of the National Longitudinal Study of Adolescent Health. Item analysis, confirmatory factor analysis, cross-validation, reliability estimates, and convergent validity coefficients strongly supported the validity of using the four items as a unidimensional composite. Implications for…
Dewitt, James; Capistrant, Benjamin; Kohli, Nidhi; Mitteldorf, Darryl; Merengwa, Enyinnaya; West, William
2018-01-01
Background While deduplication and cross-validation protocols have been recommended for large Web-based studies, protocols for survey response validation of smaller studies have not been published. Objective This paper reports the challenges of survey validation inherent in a small Web-based health survey research. Methods The subject population was North American, gay and bisexual, prostate cancer survivors, who represent an under-researched, hidden, difficult-to-recruit, minority-within-a-minority population. In 2015-2016, advertising on a large Web-based cancer survivor support network, using email and social media, yielded 478 completed surveys. Results Our manual deduplication and cross-validation protocol identified 289 survey submissions (289/478, 60.4%) as likely spam, most stemming from advertising on social media. The basic components of this deduplication and validation protocol are detailed. An unexpected challenge encountered was invalid survey responses evolving across the study period. This necessitated the static detection protocol be augmented with a dynamic one. Conclusions Five recommendations for validation of Web-based samples, especially with smaller difficult-to-recruit populations, are detailed. PMID:29691203
A Swedish cross-cultural adaptation and validation of the Tinnitus Functional Index.
Hoff, Maria; Kähäri, Kim
2017-04-01
The Tinnitus Functional Index (TFI) is a recent self-report instrument for tinnitus with potential advantages over other existing instruments, including a demonstrated high responsiveness. The objectives of this study were to translate and cross-culturally adapt the TFI into Swedish and to investigate its validity and reliability. The development of the Swedish version (TFI-SE) followed published guidelines on cross-cultural adaptation of health questionnaires. Validity and reliability was investigated by correlating responses on the TFI-SE with other tinnitus measures [Tinnitus Handicap Inventory (THI) and visual analogue scale (VAS)] and a scale measuring anxiety and depression (HADS). Consecutively recruited tinnitus patients (n = 100) from four Swedish clinics completed the questionnaires. The mean age of the sample was 51 years (SD =17). The internal consistency of the TFI-SE was good (α = 0.95) and the test-retest reliability was high (ICC =0.93). Our results supported the eight-factor structure proposed for the original TFI, and a high correlation between the TFI-SE and the THI (r = 0.8; p < 0.01) and lower correlations between the TFI-SE and the HADS-D (r = 0.60; p < 0.01) and HADS-A (r = 0.59; p < 0.01) confirmed satisfactory convergent and discriminant validity. We found that the Swedish translation and cross-cultural adaptation of the TFI is valid and reliable for use with adult tinnitus patients.
Cross-validation of an employee safety climate model in Malaysia.
Bahari, Siti Fatimah; Clarke, Sharon
2013-06-01
Whilst substantial research has investigated the nature of safety climate, and its importance as a leading indicator of organisational safety, much of this research has been conducted with Western industrial samples. The current study focuses on the cross-validation of a safety climate model in the non-Western industrial context of Malaysian manufacturing. The first-order factorial validity of Cheyne et al.'s (1998) [Cheyne, A., Cox, S., Oliver, A., Tomas, J.M., 1998. Modelling safety climate in the prediction of levels of safety activity. Work and Stress, 12(3), 255-271] model was tested, using confirmatory factor analysis, in a Malaysian sample. Results showed that the model fit indices were below accepted levels, indicating that the original Cheyne et al. (1998) safety climate model was not supported. An alternative three-factor model was developed using exploratory factor analysis. Although these findings are not consistent with previously reported cross-validation studies, we argue that previous studies have focused on validation across Western samples, and that the current study demonstrates the need to take account of cultural factors in the development of safety climate models intended for use in non-Western contexts. The results have important implications for the transferability of existing safety climate models across cultures (for example, in global organisations) and highlight the need for future research to examine cross-cultural issues in relation to safety climate. Copyright © 2013 National Safety Council and Elsevier Ltd. All rights reserved.
Duarte Bonini Campos, J A; Dias do Prado, C
2012-01-01
The cross-cultural adaptation of the Patient-Generated Subjective Global Assessment is important so it can be used with confidence in Portuguese language. To perform a cross-cultural adaptation of the Portuguese version of the Patient-Generated Subjective Global Assessment and to estimate its intrarater reliability. This is a validation study. Face Validity was classified by 17 health professionals and 10 Portuguese language specialists. Idiomatic, semantic, cultural and conceptual equivalences were analyzed. The questionnaire was completed by 20 patients of the Amaral Carvalho Hospital (Jaú, São Paulo, Brazil) in order to verify the Comprehension Index of each item. Therefore, 27 committee members classified each item into "essential", "useful, but not essential" and "not necessary", in order to calculate the Content Validity Ratio. After, this version of the questionnaire was applied twice to 62 patients of the hospital cited above. The intrarater reliability of the nutritional status analyzed by Patient-Generated Subjective Global Assessment was estimated by Kappa statistics. The Portuguese version of the Patient-Generated Subjective Global Assessment presented 10 incomprehensible expressions. The items "a year ago weight" and "dry mouth symptom" presented the lowest Content Validity Ratio. Substantial intrarater reliability (k = 0.78, p = 0.001) was observed. The cross-cultural adaptation of the Portuguese version of the Patient-Generated Subjective Global Assessment became simple and understandable for Brazilian patients. Thus, this version of the Patient-Generated Subjective Global Assessment was considered a valid and a reliable method.
ERIC Educational Resources Information Center
Zhu, Zheng; Chen, Peijie; Zhuang, Jie
2013-01-01
Purpose: The purpose of this study was to develop and cross-validate an equation based on ActiGraph accelerometer GT3X output to predict children and youth's energy expenditure (EE) of physical activity (PA). Method: Participants were 367 Chinese children and youth (179 boys and 188 girls, aged 9 to 17 years old) who wore 1 ActiGraph GT3X…
ERIC Educational Resources Information Center
Anderson, Daniel; Alonzo, Julie; Tindal, Gerald
2011-01-01
In this technical report, we document the results of a cross-validation study designed to identify optimal cut-scores for the use of the easyCBM[R] mathematics test in the state of Washington. A large sample, randomly split into two groups of roughly equal size, was used for this study. Students' performance classification on the Washington state…
A Cross-Validation of easyCBM[R] Mathematics Cut Scores in Oregon: 2009-2010. Technical Report #1104
ERIC Educational Resources Information Center
Anderson, Daniel; Alonzo, Julie; Tindal, Gerald
2011-01-01
In this technical report, we document the results of a cross-validation study designed to identify optimal cut-scores for the use of the easyCBM[R] mathematics test in Oregon. A large sample, randomly split into two groups of roughly equal size, was used for this study. Students' performance classification on the Oregon state test was used as the…
NASA Astrophysics Data System (ADS)
Pescarini, M.; Sinitsa, V.; Orsi, R.; Frisoni, M.
2013-03-01
This paper presents a synthesis of the ENEA-Bologna Nuclear Data Group programme dedicated to generate and validate group-wise cross section libraries for shielding and radiation damage deterministic calculations in nuclear fission reactors, following the data processing methodology recommended in the ANSI/ANS-6.1.2-1999 (R2009) American Standard. The VITJEFF311.BOLIB and VITENDF70.BOLIB finegroup coupled n-γ (199 n + 42 γ - VITAMIN-B6 structure) multi-purpose cross section libraries, based on the Bondarenko method for neutron resonance self-shielding and respectively on JEFF-3.1.1 and ENDF/B-VII.0 evaluated nuclear data, were produced in AMPX format using the NJOY-99.259 and the ENEA-Bologna 2007 Revision of the SCAMPI nuclear data processing systems. Two derived broad-group coupled n-γ (47 n + 20 γ - BUGLE-96 structure) working cross section libraries in FIDO-ANISN format for LWR shielding and pressure vessel dosimetry calculations, named BUGJEFF311.BOLIB and BUGENDF70.BOLIB, were generated by the revised version of SCAMPI, through problem-dependent cross section collapsing and self-shielding from the cited fine-group libraries. The validation results on the criticality safety benchmark experiments for the fine-group libraries and the preliminary validation results for the broad-group working libraries on the PCA-Replica and VENUS-3 engineering neutron shielding benchmark experiments are reported in synthesis.
A generalized optimization principle for asymmetric branching in fluidic networks
Stephenson, David
2016-01-01
When applied to a branching network, Murray’s law states that the optimal branching of vascular networks is achieved when the cube of the parent channel radius is equal to the sum of the cubes of the daughter channel radii. It is considered integral to understanding biological networks and for the biomimetic design of artificial fluidic systems. However, despite its ubiquity, we demonstrate that Murray’s law is only optimal (i.e. maximizes flow conductance per unit volume) for symmetric branching, where the local optimization of each individual channel corresponds to the global optimum of the network as a whole. In this paper, we present a generalized law that is valid for asymmetric branching, for any cross-sectional shape, and for a range of fluidic models. We verify our analytical solutions with the numerical optimization of a bifurcating fluidic network for the examples of laminar, turbulent and non-Newtonian fluid flows. PMID:27493583
Social anxiety and the interpretation of positive social events.
Alden, Lynn E; Taylor, Charles T; Mellings, Tanna M J B; Laposa, Judith M
2008-05-01
We report four independent studies that examined the relationship between social interaction anxiety and the tendency to interpret positive social events in a threat-maintaining manner. Study 1 described the development of a scale that measures negative interpretations of positive social events, the interpretation of positive events scale (IPES). Study 2 cross-validated the structure of the IPES and established that social interaction anxiety explained significant variance in negative interpretations of positive social events beyond negative affect in general. Study 3 demonstrated that negative interpretation of positive events was significantly greater in a clinical sample of patients with generalized social anxiety disorder (GSAD) than a matched group of non-anxious community controls. In addition, within the GSAD group, the IPES was associated with negative social predictions following a positive interaction. Finally, study 4 confirmed that negative interpretations of positive social events mediated the relationship between social interaction anxiety and low positive affect.
Kloog, Itai; Nordio, Francesco; Coull, Brent A; Schwartz, Joel
2012-11-06
Satellite-derived aerosol optical depth (AOD) measurements have the potential to provide spatiotemporally resolved predictions of both long and short-term exposures, but previous studies have generally shown moderate predictive power and lacked detailed high spatio- temporal resolution predictions across large domains. We aimed at extending our previous work by validating our model in another region with different geographical and metrological characteristics, and incorporating fine scale land use regression and nonrandom missingness to better predict PM(2.5) concentrations for days with or without satellite AOD measures. We start by calibrating AOD data for 2000-2008 across the Mid-Atlantic. We used mixed models regressing PM(2.5) measurements against day-specific random intercepts, and fixed and random AOD and temperature slopes. We used inverse probability weighting to account for nonrandom missingness of AOD, nested regions within days to capture spatial variation in the daily calibration, and introduced a penalization method that reduces the dimensionality of the large number of spatial and temporal predictors without selecting different predictors in different locations. We then take advantage of the association between grid-cell specific AOD values and PM(2.5) monitoring data, together with associations between AOD values in neighboring grid cells to develop grid cell predictions when AOD is missing. Finally to get local predictions (at the resolution of 50 m), we regressed the residuals from the predictions for each monitor from these previous steps against the local land use variables specific for each monitor. "Out-of-sample" 10-fold cross-validation was used to quantify the accuracy of our predictions at each step. For all days without AOD values, model performance was excellent (mean "out-of-sample" R(2) = 0.81, year-to-year variation 0.79-0.84). Upon removal of outliers in the PM(2.5) monitoring data, the results of the cross validation procedure was even better (overall mean "out of sample"R(2) of 0.85). Further, cross validation results revealed no bias in the predicted concentrations (Slope of observed vs predicted = 0.97-1.01). Our model allows one to reliably assess short-term and long-term human exposures in order to investigate both the acute and effects of ambient particles, respectively.
Asymptotic quantum inelastic generalized Lorenz Mie theory
NASA Astrophysics Data System (ADS)
Gouesbet, G.
2007-10-01
The (electromagnetic) generalized Lorenz-Mie theory describes the interaction between an electromagnetic arbitrary shaped beam and a homogeneous sphere. It is a generalization of the Lorenz-Mie theory which deals with the simpler case of a plane wave illumination. In a recent paper, we consider (i) elastic cross-sections in electromagnetic generalized Lorenz-Mie theory and (ii) elastic cross-sections in an associated quantum generalized Lorenz-Mie theory. We demonstrated that the electromagnetic problem is equivalent to a superposition of two effective quantum problems. We now intend to generalize this result from elastic cross-sections to inelastic cross-sections. A prerequisite is to build an asymptotic quantum inelastic generalized Lorenz-Mie theory, which is presented in this paper.
Olsen, Espen
2010-09-01
The aim of the present study was to explore the possibility of identifying general safety climate concepts in health care and petroleum sectors, as well as develop and test the possibility of a common cross-industrial structural model. Self-completion questionnaire surveys were administered in two organisations and sectors: (1) a large regional hospital in Norway that offers a wide range of hospital services, and (2) a large petroleum company that produces oil and gas worldwide. In total, 1919 and 1806 questionnaires were returned from the hospital and petroleum organisation, with response rates of 55 percent and 52 percent, respectively. Using a split sample procedure principal factor analysis and confirmatory factor analysis revealed six identical cross-industrial measurement concepts in independent samples-five measures of safety climate and one of safety behaviour. The factors' psychometric properties were explored with satisfactory internal consistency and concept validity. Thus, a common cross-industrial structural model was developed and tested using structural equation modelling (SEM). SEM revealed that a cross-industrial structural model could be identified among health care workers and offshore workers in the North Sea. The most significant contributing variables in the model testing stemmed from organisational management support for safety and supervisor/manager expectations and actions promoting safety. These variables indirectly enhanced safety behaviour (stop working in dangerous situations) through transitions and teamwork across units, and teamwork within units as well as learning, feedback, and improvement. Two new safety climate instruments were validated as part of the study: (1) Short Safety Climate Survey (SSCS) and (2) Hospital Survey on Patient Safety Culture-short (HSOPSC-short). Based on development of measurements and structural model assessment, this study supports the possibility of a common safety climate structural model across health care and the offshore petroleum industry. 2010 Elsevier Ltd. All rights reserved.
Aloba, Olutayo; Ajao, Olayinka; Alimi, Taiwo; Esan, Olufemi
2016-01-01
Objectives: To examine the construct and correlates of hopelessness among family caregivers of Nigerian psychiatric patients. Materials and Methods: This is a cross-sectional, descriptive study involving 264 family caregiver-patients’ dyads recruited from two university teaching hospitals psychiatric clinics in Southwestern Nigeria. Results: Exploratory factor analysis revealed a two-factor 9-item model of the Beck Hopelessness Scale (BHS) among the family caregivers. Confirmatory factor analysis of the model revealed satisfactory indices of fitness (goodness of fit index = 0.97, comparative fit index = 0.96, Chi-square/degree of freedom (CMIN/DF) = 1.60, root mean square error of approximation = 0.048, expected cross-validation index = 0.307, and standardized root mean residual = 0.005). Reliability of the scale was modestly satisfactory (Cronbach's alpha 0.72). Construct validity of scale was supported by significant correlations with the family caregivers’ scores on the Zarit Burden Interview, mini international neuropsychiatric interview suicidality module, General Health Questionnaire-12 (GHQ-12), and Patient Health Questionnaire-9. The greatest variance in the family caregivers’ scores on the BHS was contributed by their scores on the psychological distress scale (GHQ-12). Conclusions: The BHS has adequate psychometric properties among Nigerian psychiatric patients’ family caregivers. There is the need to pay attention to the psychological well-being of the family caregivers of Nigerian psychiatric patients. PMID:28163498
Contreras-Torres, Ernesto
2018-06-02
In this study, I introduce novel global and local 0D-protein descriptors based on a statistical quantity named Total Sum of Squares (TSS). This quantity represents the sum of the squares differences of amino acid properties from the arithmetic mean property. As an extension, the amino acid-types and amino acid-groups formalisms are used for describing zones of interest in proteins. To assess the effectiveness of the proposed descriptors, a Nearest Neighbor model for predicting the major four protein structural classes was built. This model has a success rate of 98.53% on the jackknife cross-validation test; this performance being superior to other reported methods despite the simplicity of the predictor. Additionally, this predictor has an average success rate of 98.35% in different cross-validation tests performed. A value of 0.98 for the Kappa statistic clearly discriminates this model from a random predictor. The results obtained by the Nearest Neighbor model demonstrated the ability of the proposed descriptors not only to reflect relevant biochemical information related to the structural classes of proteins but also to allow appropriate interpretability. It can thus be expected that the current method may play a supplementary role to other existing approaches for protein structural class prediction and other protein attributes. Copyright © 2018 Elsevier Ltd. All rights reserved.
Kersten, Paula; Dudley, Margaret; Nayar, Shoba; Elder, Hinemoa; Robertson, Heather; Tauroa, Robyn; McPherson, Kathryn M
2016-10-12
Screening children for behavioural difficulties requires the use of a tool that is culturally valid. We explored the cross-cultural acceptability and utility of the Strengths and Difficulties Questionnaire for pre-school children (aged 3-5) as perceived by families in New Zealand. A qualitative interpretive descriptive study (focus groups and interviews) in which 65 participants from five key ethnic groups (New Zealand European, Māori, Pacific, Asian and other immigrant parents) took part. Thematic analysis using an inductive approach, in which the themes identified are strongly linked to the data, was employed. Many parents reported they were unclear about the purpose of the tool, affecting its perceived value. Participants reported not understanding the context in which they should consider the questions and had difficulty understanding some questions and response options. Māori parents generally did not support the questionnaire based approach, preferring face to face interaction. Parents from Māori, Pacific Island, Asian, and new immigrant groups reported the tool lacked explicit consideration of children in their cultural context. Parents discussed the importance of timing and multiple perspectives when interpreting scores from the tool. In summary, this study posed a number of challenges to the use of the Strengths and Difficulties Questionnaire in New Zealand. Further work is required to develop a tool that is culturally appropriate with good content validity.
[Hyperspectral remote sensing image classification based on SVM optimized by clonal selection].
Liu, Qing-Jie; Jing, Lin-Hai; Wang, Meng-Fei; Lin, Qi-Zhong
2013-03-01
Model selection for support vector machine (SVM) involving kernel and the margin parameter values selection is usually time-consuming, impacts training efficiency of SVM model and final classification accuracies of SVM hyperspectral remote sensing image classifier greatly. Firstly, based on combinatorial optimization theory and cross-validation method, artificial immune clonal selection algorithm is introduced to the optimal selection of SVM (CSSVM) kernel parameter a and margin parameter C to improve the training efficiency of SVM model. Then an experiment of classifying AVIRIS in India Pine site of USA was performed for testing the novel CSSVM, as well as a traditional SVM classifier with general Grid Searching cross-validation method (GSSVM) for comparison. And then, evaluation indexes including SVM model training time, classification overall accuracy (OA) and Kappa index of both CSSVM and GSSVM were all analyzed quantitatively. It is demonstrated that OA of CSSVM on test samples and whole image are 85.1% and 81.58, the differences from that of GSSVM are both within 0.08% respectively; And Kappa indexes reach 0.8213 and 0.7728, the differences from that of GSSVM are both within 0.001; While the ratio of model training time of CSSVM and GSSVM is between 1/6 and 1/10. Therefore, CSSVM is fast and accurate algorithm for hyperspectral image classification and is superior to GSSVM.
Garbarino, Sergio; Winwood, Peter C.
2015-01-01
Background. The aim of this study was to cross-culturally adapt the Psychological Injury Risk Indicator (PIRI) and to validate its psychometric properties. Methods. Workers from 24 small companies were invited to self-complete the PIRI before undergoing their routine medical examination at the workplace. All participants (841 out of 845, 99.6%) were also asked to report occupational injuries and episodes of violence that had occurred at the workplace in the previous 12 months and were given the General Health Questionnaire (GHQ12) to complete. Results. Exploratory factor analysis revealed a 4-factor structure, “sleep problems,” “recovery failure,” “posttraumatic stress symptoms,” and “chronic fatigue,” which were the same subscales observed in the original version. The internal consistency was excellent (alpha = 0.932). ROC curve analysis revealed that the PIRI was much more efficient than GHQ12 in diagnosing workers who had suffered trauma (workplace violence or injury) in the previous year, as it revealed an area under the curve (AUC) of 0.679 (95% CI: 0.625–0.734) for the PIRI, while for the GHQ12 the AUC was 0.551 (not significant). Conclusions. This study, performed on a large population of workers, provides evidence of the validity of the Italian version of the PIRI. PMID:25839055
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brown, C; Adcock, A; Azevedo, S
2010-12-28
Some diagnostics at the National Ignition Facility (NIF), including the Gamma Reaction History (GRH) diagnostic, require multiple channels of data to achieve the required dynamic range. These channels need to be stitched together into a single time series, and they may have non-uniform and redundant time samples. We chose to apply the popular cubic smoothing spline technique to our stitching problem because we needed a general non-parametric method. We adapted one of the algorithms in the literature, by Hutchinson and deHoog, to our needs. The modified algorithm and the resulting code perform a cubic smoothing spline fit to multiple datamore » channels with redundant time samples and missing data points. The data channels can have different, time-varying, zero-mean white noise characteristics. The method we employ automatically determines an optimal smoothing level by minimizing the Generalized Cross Validation (GCV) score. In order to automatically validate the smoothing level selection, the Weighted Sum-Squared Residual (WSSR) and zero-mean tests are performed on the residuals. Further, confidence intervals, both analytical and Monte Carlo, are also calculated. In this paper, we describe the derivation of our cubic smoothing spline algorithm. We outline the algorithm and test it with simulated and experimental data.« less
Uchoa, Priscila Regina Candido Espinola; Bezerra, Thiago Freire Pinto; Lima, Élcio Duarte; Fornazieri, Marco Aurélio; Pinna, Fabio de Rezende; Sperandio, Fabiana de Araújo; Voegels, Richard Louis
The concept of quality of life is subjective and variable definition, which depends on the individual's perception of their state of health. Quality of life questionnaires are instruments designed to measure quality of life, but most are developed in a language other than Portuguese. Questionnaires can identify the most important symptoms, focus on consultation, and assist in defining the goals of treatment. Some of these have been validated for the Portuguese language, but none in children. To validate the translation with cross-cultural adaptation and validation of the Sinus and Nasal Quality of Life Survey (SN-5) into Portuguese. Prospective study of children aged 2-12 years with sinonasal symptoms of over 30 days. The study comprised two stages: (I) translation and cross-cultural adaptation of the SN-5 into Portuguese (SN-5p); and (II) validation of the SN5-p. Statistical analysis was performed to assess internal consistency, test-retest reliability, and sensitivity, as well as construct and discriminant validity and standardization. The SN-5 was translated and adapted into Portuguese (SN-5p) and the author of the original version approved the process. Validation was carried out by administration of the SN-5p to 51 pediatric patients with sinonasal complaints (mean age, 5.8±2.5 years; range, 2-12 years). The questionnaire exhibited adequate construct validity (0.62, p<0.01), internal consistency (Cronbach's alpha=0.73), and discriminant validity (p<0.01), as well as good test-retest reproducibility (Goodman-Kruskal gamma=0.957, p<0.001), good correlation with a visual analog scale (r=0.62, p<0.01), and sensitivity to change. This study reports the successful translation and cross-cultural adaptation of the SN-5 instrument into Brazilian Portuguese. The translated version exhibited adequate psychometric properties for assessment of disease-specific quality of life in pediatric patients with sinonasal complaints. Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.
NASA Astrophysics Data System (ADS)
Cánovas-García, Fulgencio; Alonso-Sarría, Francisco; Gomariz-Castillo, Francisco; Oñate-Valdivieso, Fernando
2017-06-01
Random forest is a classification technique widely used in remote sensing. One of its advantages is that it produces an estimation of classification accuracy based on the so called out-of-bag cross-validation method. It is usually assumed that such estimation is not biased and may be used instead of validation based on an external data-set or a cross-validation external to the algorithm. In this paper we show that this is not necessarily the case when classifying remote sensing imagery using training areas with several pixels or objects. According to our results, out-of-bag cross-validation clearly overestimates accuracy, both overall and per class. The reason is that, in a training patch, pixels or objects are not independent (from a statistical point of view) of each other; however, they are split by bootstrapping into in-bag and out-of-bag as if they were really independent. We believe that putting whole patch, rather than pixels/objects, in one or the other set would produce a less biased out-of-bag cross-validation. To deal with the problem, we propose a modification of the random forest algorithm to split training patches instead of the pixels (or objects) that compose them. This modified algorithm does not overestimate accuracy and has no lower predictive capability than the original. When its results are validated with an external data-set, the accuracy is not different from that obtained with the original algorithm. We analysed three remote sensing images with different classification approaches (pixel and object based); in the three cases reported, the modification we propose produces a less biased accuracy estimation.
Stability of an empirical psychosocial taxonomy across type of diabetes and treatment.
Nouwen, A; Breton, M-C; Urquhart Law, G; Descôteaux, J
2007-01-01
The aims of the study were (i) to examine whether an empirical psychosocial taxonomy, based on key diabetes-related variables, is independent of type of diabetes and treatment, and (ii) to further establish the external validation of the taxonomy. In a cross-sectional study, 82 patients with Type 1 and 86 patients with Type 2 diabetes mellitus were assigned to one of three psychosocial patient profiles based on their Multidimensional Diabetes Questionnaire (MDQ) scores. General psychological and diabetes-specific measures were obtained through self-report and HbA(1c) was measured. Equal proportions of Type 1 and Type 2 patients, and of patients using insulin and oral medication/diet only were classified within each of the three psychosocial profiles. External validation confirmed the validity and distinctiveness of the patients' profiles. The patient profiles were independent of demographic variables, body mass index, duration of diabetes, complexity of treatment, number of complications, social desirability, and major stress levels. The Psychosocial Taxonomy for Patients with Diabetes provides a new way to categorize individuals who may have more in common than just their type of diabetes and/or its treatment and can help target interventions to individual patients' needs.
Berendsen, Annette J; Groenier, Klaas H; de Jong, G Majella; Meyboom-de Jong, Betty; van der Veen, Willem Jan; Dekker, Janny; de Waal, Margot W M; Schuling, Jan
2009-10-01
Development and validation of a questionnaire that measures patients' experiences of collaboration between general practitioners (GPs) and specialists. A questionnaire was developed using the method of the consumer quality index and validated in a cross-sectional study among a random sample of patients referred to medical specialists in the Netherlands. Validation included factor analysis, ascertain internal consistency, and the discriminative ability. The response rate was 65% (1404 patients). Exploratory factor analysis indicated that four domains could be distinguished (i.e. GP Approach; GP Referral; Specialist; Collaboration). Cronbach's alpha coefficients ranged from 0.51 to 0.93 indicating sufficient internal consistency to make comparison of groups of respondents possible. The Pearson correlation coefficients between the domains were <0.4, except between the domains GP Approach and GP Referral. All domains clearly produced discriminating scores for groups with different characteristics. The Consumer Quality Index (CQ-index) Continuum of Care can be a useful instrument to assess aspects of the collaboration between GPs and specialists from patients' perspective. It can be used to give feedback to both medical professionals and policy makers. Such feedback creates an opportunity for implementing specific improvements and evaluating quality improvement projects. 2009 Elsevier Ireland Ltd.
Simplified Model to Predict Deflection and Natural Frequency of Steel Pole Structures
NASA Astrophysics Data System (ADS)
Balagopal, R.; Prasad Rao, N.; Rokade, R. P.
2018-04-01
Steel pole structures are suitable alternate to transmission line towers, due to difficulty encountered in finding land for the new right of way for installation of new lattice towers. The steel poles have tapered cross section and they are generally used for communication, power transmission and lighting purposes. Determination of deflection of steel pole is important to decide its functionality requirement. The excessive deflection of pole may affect the signal attenuation and short circuiting problems in communication/transmission poles. In this paper, a simplified method is proposed to determine both primary and secondary deflection based on dummy unit load/moment method. The predicted deflection from proposed method is validated with full scale experimental investigation conducted on 8 m and 30 m high lighting mast, 132 and 400 kV transmission pole and found to be in close agreement with each other. Determination of natural frequency is an important criterion to examine its dynamic sensitivity. A simplified semi-empirical method using the static deflection from the proposed method is formulated to determine its natural frequency. The natural frequency predicted from proposed method is validated with FE analysis results. Further the predicted results are validated with experimental results available in literature.
Worrell, Frank C; Andretta, James R; Woodland, Malcolm H
2014-10-01
In this study, we examined the internal consistency and structural validity of Cross Racial Identity Scale (CRIS) scores in a sample of 477 African American adolescents who had been arrested in a city in the mid-Atlantic. Using cluster analysis, we also identified profiles of CRIS scores and compared adolescents with different profiles on Major Depressive Episode, Manic Episode, Generalized Anxiety Disorder, and Obsessive-Compulsive Disorder scores. Results indicated that CRIS subscale scores were reliable, and the 6-factor structure of the CRIS was supported. Five nigrescence profiles were identified: Miseducation-Pro-Black, Conflicted-Self-Hatred, Multiculturalist, Low Race Salience, and Conflicted-Anti-White. Individuals with Conflicted-Self-Hatred profiles reported significantly and meaningfully higher scores on the 4 syndromes than did their peers, and individuals with the Multiculturalist and Low Race Salience profiles reported the lowest scores. A greater percentage of individuals with Conflicted racial identity profiles had syndrome scores in the clinically significant range. The results of this study demonstrate that some of the nigrescence profiles found in college-age students generalize to adolescents. The implications of the findings for theory, research, and practice are discussed. PsycINFO Database Record (c) 2014 APA, all rights reserved.
Rudolph, Abby E; Bazzi, Angela Robertson; Fish, Sue
2016-10-01
Analyses with geographic data can be used to identify "hot spots" and "health service deserts", examine associations between proximity to services and their use, and link contextual factors with individual-level data to better understand how environmental factors influence behaviors. Technological advancements in methods for collecting this information can improve the accuracy of contextually-relevant information; however, they have outpaced the development of ethical standards and guidance, particularly for research involving populations engaging in illicit/stigmatized behaviors. Thematic analysis identified ethical considerations for collecting geographic data using different methods and the extent to which these concerns could influence study compliance and data validity. In-depth interviews with 15 Baltimore residents (6 recruited via flyers and 9 via peer-referral) reporting recent drug use explored comfort with and ethics of three methods for collecting geographic information: (1) surveys collecting self-reported addresses/cross-streets, (2) surveys using web-based maps to find/confirm locations, and (3) geographical momentary assessments (GMA), which collect spatiotemporally referenced behavioral data. Survey methods for collecting geographic data (i.e., addresses/cross-streets and web-based maps) were generally acceptable; however, participants raised confidentiality concerns regarding exact addresses for illicit/stigmatized behaviors. Concerns specific to GMA included burden of carrying/safeguarding phones and responding to survey prompts, confidentiality, discomfort with being tracked, and noncompliance with study procedures. Overall, many felt that confidentiality concerns could influence the accuracy of location information collected for sensitive behaviors and study compliance. Concerns raised by participants could result in differential study participation and/or study compliance and questionable accuracy/validity of location data for sensitive behaviors. Copyright © 2016 Elsevier Ltd. All rights reserved.
Preti, Antonio; Sheehan, David V; Coric, Vladimir; Distinto, Marco; Pitanti, Mirko; Vacca, Irene; Siddi, Alessandra; Masala, Carmelo; Petretto, Donatella Rita
2013-10-01
The Sheehan Suicidality Tracking Scale (S-STS) is a patient self-report or clinician-administered rating scale that tracks spontaneous and treatment-emergent suicidal ideation and behaviors. This study set out to evaluate the reliability, convergent and divergent validity of the S-STS in a sample of college students, a population with a high risk of completed and attempted suicide. Cross-sectional, survey design. Participants (303 undergraduate students; males: 42%) completed several measures assessing psychological distress (General Health Questionnaire; GHQ); self-esteem (Rosenberg Self Esteem Scale; RSES); social support (Modified Social Support Survey; MOSSS); and suicidal behavior, including ideation and attempts (S-STS). Both internal consistency and test-retest stability were excellent for the S-STS-global score. The S-STS subscale on suicide ideation also showed good reliability, while the subscale on suicidal behavior showed some inconsistency at retest. Convergent and divergent validity of S-STS was confirmed. All S-STS items loaded on a single factor, which had an excellent fit for the unidimensional model, thus justifying the use of the S-STS as a screening tool. In a mediation model, self-esteem and social support explained 45% of the effects of psychological distress on suicide ideation and behavior as measured by the S-STS-global score. This study provided promising evidence on the convergent, divergent, internal consistency and test-retest stability of the Sheehan Suicidality Tracking Scale. The cross-sectional design and lack of measures of hopelessness and helplessness prevent any conclusion about the links of suicidal behavior with self-esteem and social support. Copyright © 2013 Elsevier Inc. All rights reserved.
Yunus, Raudah Mohd; Wazid, Syeda Wasfeea; Hairi, Noran N; Choo, Wan Yuen; Hairi, Farizah M; Sooryanarayana, Rajini; Ahmad, Sharifah N; Razak, Inayah A; Peramalah, Devi; Aziz, Suriyati A; Mohamad, Zaiton L; Mohamad, Rosmala; Ali, Zainudin M; Bulgiba, Awang
2017-01-01
To examine the association between elder abuse and poor sleep using a Malay validated version of Pittsburgh Sleep Quality Index (PSQI). This study was divided into two phases. Phase I tested the construct validity and reliability of the Malay version of PSQI. Phase II was a population-based, cross-sectional study with a multi-stage cluster sampling method. Home-based interviews were conducted by trained personnel using a structured questionnaire, to determine exposure and outcome. Kuala Pilah, a district in Negeri Sembilan which is one of the fourteen states in Malaysia. 1648 community-dwelling older Malaysians. The Malay version of PSQI had significant test re-test reliability with intra-class correlation coefficients of 0.62. Confirmatory factor analyses revealed that one factor PSQI scale with three components (subjective sleep quality, sleep latency, and sleep disturbances) was most suitable. Cronbach's Alpha was 0.60 and composite reliability was 0.63. PSQI scores were highest among neglect (4.11), followed by physical (4.10), psychological (3.96) and financial abuse (3.60). There was a dose-response relationship between clustering of abuse and PSQI scores; 3.41, 3.50 and 3.84 for "no abuse", "1 type of abuse" and "2 types or more". Generalized linear models revealed six variables as significant determinants of sleep quality-abuse, co-morbidities, self-rated health, income, social support and gait speed. Among abuse subtypes, only neglect was significantly associated with poor sleep. The Malay PSQI was valid and reliable. Abuse was significantly associated with poor sleep. As sleep is essential for health and is a good predictor for mortality among older adults, management of abuse victims should entail sleep assessment. Interventions or treatment modalities which focus on improving sleep quality among abuse victims should be designed.
Young, J W; Geyer, M A; Rissling, A J; Sharp, R F; Eyler, L T; Asgaard, G L; Light, G A
2013-01-01
Attentional dysfunction in schizophrenia (SZ) is a core deficit that contributes to multiple cognitive deficits and the resulting functional disability. However, developing procognitive therapeutics for neuropsychiatric disorders have been limited by a ‘translational gap'—a lack of cognitive paradigms having cross-species translational validity and relevance. The present study was designed to perform an initial validation of the cross-species homology of the 5-choice Continuous Performance Test (5C-CPT) in healthy nonpsychiatric comparison subjects (NCS), SZ patients and mice under pharmacologic challenge. The 5C-CPT performance in SZ patients (n=20) was compared with age-matched NCS (n=23). The effects of the general muscarinic receptor antagonist scopolamine on mice (n=21) performing the 5C-CPT were also assessed. SZ subjects exhibited significantly impaired attention in the 5C-CPT, driven by reduced target detection over time and nonsignificantly increased impulsive responding. Similarly, scopolamine significantly impaired attention in mice, driven by reduced target detection and nonsignificantly increased impulsive responding. Scopolamine also negatively affected accuracy and speed of responding in mice, although these measures failed to differentiate SZ vs NCS. Thus, mice treated with scopolamine exhibited similar impairments in vigilance as seen in SZ, although the differences between the behavioral profiles warrant further study. The availability of rodent and human versions of this paradigm provides an opportunity to: (1) investigate the neuroanatomic, neurochemical and genomic architecture of abnormalities in attention observed in clinical populations such as SZ; (2) develop and refine animal models of cognitive impairments; and (3) improve cross-species translational testing for the development of treatments for these impairments. PMID:24217494
QTL mapping of stalk bending strength in a recombinant inbred line maize population.
Hu, Haixiao; Liu, Wenxin; Fu, Zhiyi; Homann, Linda; Technow, Frank; Wang, Hongwu; Song, Chengliang; Li, Shitu; Melchinger, Albrecht E; Chen, Shaojiang
2013-09-01
Stalk bending strength (SBS) is a reliable indicator for evaluating stalk lodging resistance of maize plants. Based on biomechanical considerations, the maximum load exerted to breaking (F max), the breaking moment (M max) and critical stress (σ max) are three important parameters to characterize SBS. We investigated the genetic architecture of SBS by phenotyping F max, M max and σ max of the fourth internode of maize plants in a population of 216 recombinant inbred lines derived from the cross B73 × Ce03005 evaluated in four environments. Heritability of F max, M max and σ max was 0.81, 0.79 and 0.75, respectively. F max and σ max were positively correlated with several other stalk characters. By using a linkage map with 129 SSR markers, we detected two, three and two quantitative trait loci (QTL) explaining 22.4, 26.1 and 17.2 % of the genotypic variance for F max, M max and σ max, respectively. The QTL for F max, M max and σ max located in adjacent bins 5.02 and 5.03 as well as in bin 10.04 for F max were detected with high frequencies in cross-validation. As our QTL mapping results suggested a complex polygenic inheritance for SBS-related traits, we also evaluated the prediction accuracy of two genomic prediction methods (GBLUP and BayesB). In general, we found that both explained considerably higher proportions of the genetic variance than the values obtained in QTL mapping with cross-validation. Nevertheless, the identified QTL regions could be used as a starting point for fine mapping and gene cloning.
Measurement properties of translated versions of neck-specific questionnaires: a systematic review
2011-01-01
Background Several disease-specific questionnaires to measure pain and disability in patients with neck pain have been translated. However, a simple translation of the original version doesn't guarantee similar measurement properties. The objective of this study is to critically appraise the quality of the translation process, cross-cultural validation and the measurement properties of translated versions of neck-specific questionnaires. Methods Bibliographic databases were searched for articles concerning the translation or evaluation of the measurement properties of a translated version of a neck-specific questionnaire. The methodological quality of the selected studies and the results of the measurement properties were critically appraised and rated using the COSMIN checklist and criteria for measurement properties. Results The search strategy resulted in a total of 3641 unique hits, of which 27 articles, evaluating 6 different questionnaires in 15 different languages, were included in this study. Generally the methodological quality of the translation process is poor and none of the included studies performed a cross-cultural adaptation. A substantial amount of information regarding the measurement properties of translated versions of the different neck-specific questionnaires is lacking. Moreover, the evidence for the quality of measurement properties of the translated versions is mostly limited or assessed in studies of poor methodological quality. Conclusions Until results from high quality studies are available, we advise to use the Catalan, Dutch, English, Iranian, Korean, Spanish and Turkish version of the NDI, the Chinese version of the NPQ, and the Finnish, German and Italian version of the NPDS. The Greek NDI needs cross-cultural validation and there is no methodologically sound information for the Swedish NDI. For all other languages we advise to translate the original version of the NDI. PMID:21645355
Measurement properties of translated versions of neck-specific questionnaires: a systematic review.
Schellingerhout, Jasper M; Heymans, Martijn W; Verhagen, Arianne P; de Vet, Henrica C; Koes, Bart W; Terwee, Caroline B
2011-06-06
Several disease-specific questionnaires to measure pain and disability in patients with neck pain have been translated. However, a simple translation of the original version doesn't guarantee similar measurement properties. The objective of this study is to critically appraise the quality of the translation process, cross-cultural validation and the measurement properties of translated versions of neck-specific questionnaires. Bibliographic databases were searched for articles concerning the translation or evaluation of the measurement properties of a translated version of a neck-specific questionnaire. The methodological quality of the selected studies and the results of the measurement properties were critically appraised and rated using the COSMIN checklist and criteria for measurement properties. The search strategy resulted in a total of 3641 unique hits, of which 27 articles, evaluating 6 different questionnaires in 15 different languages, were included in this study. Generally the methodological quality of the translation process is poor and none of the included studies performed a cross-cultural adaptation. A substantial amount of information regarding the measurement properties of translated versions of the different neck-specific questionnaires is lacking. Moreover, the evidence for the quality of measurement properties of the translated versions is mostly limited or assessed in studies of poor methodological quality. Until results from high quality studies are available, we advise to use the Catalan, Dutch, English, Iranian, Korean, Spanish and Turkish version of the NDI, the Chinese version of the NPQ, and the Finnish, German and Italian version of the NPDS. The Greek NDI needs cross-cultural validation and there is no methodologically sound information for the Swedish NDI. For all other languages we advise to translate the original version of the NDI.
NASA Astrophysics Data System (ADS)
Sharma, Sushil K.; Kamys, Bogusław; Goldenbaum, Frank; Filges, Detlef
2016-06-01
Double-differential cross-sections d2σ/dΩ dE for isotopically identified intermediate mass fragments ( 6Li up to 27Mg from nuclear reactions induced by 480 MeV protons impinging on a silver target were analyzed in the frame of a two-step model. The first step of the reaction was described by the intranuclear cascade model INCL4.6 and the second one by four different models (ABLA07,GEM2, GEMINI++, and SMM). The experimental spectra reveal the presence of low-energy, isotropic as well as high-energy, forward-peaked contributions. The INCL4.6 model offers a possibility to describe the latter contribution for light intermediate mass fragments by coalescence of the emitted nucleons. The qualitative agreement of the model predictions with the data was observed but the high-energy tails of the spectra were significantly overestimated. The shape of the isotropic part of the spectra was reproduced by all four models. The GEM2 model strongly underestimated the value of the cross-sections for heavier IMF whereas the SMM and ABLA07 models generally overestimated the data. The best quantitative description of the data was offered by GEMINI++, however, a discrepancy between the data and the model cross-sections still remained for almost all reaction products, especially at forward angles. It indicates that non-equilibrium processes are present which cannot be reproduced by the applied models. The goodness of the data description was judged quantitatively using two statistical deviation factors, the H-factor and the M-factor, as a tool for ranking and validation of the theoretical models.
Mind your crossings: Mining GIS imagery for crosswalk localization.
Ahmetovic, Dragan; Manduchi, Roberto; Coughlan, James M; Mascetti, Sergio
2017-04-01
For blind travelers, finding crosswalks and remaining within their borders while traversing them is a crucial part of any trip involving street crossings. While standard Orientation & Mobility (O&M) techniques allow blind travelers to safely negotiate street crossings, additional information about crosswalks and other important features at intersections would be helpful in many situations, resulting in greater safety and/or comfort during independent travel. For instance, in planning a trip a blind pedestrian may wish to be informed of the presence of all marked crossings near a desired route. We have conducted a survey of several O&M experts from the United States and Italy to determine the role that crosswalks play in travel by blind pedestrians. The results show stark differences between survey respondents from the U.S. compared with Italy: the former group emphasized the importance of following standard O&M techniques at all legal crossings (marked or unmarked), while the latter group strongly recommended crossing at marked crossings whenever possible. These contrasting opinions reflect differences in the traffic regulations of the two countries and highlight the diversity of needs that travelers in different regions may have. To address the challenges faced by blind pedestrians in negotiating street crossings, we devised a computer vision-based technique that mines existing spatial image databases for discovery of zebra crosswalks in urban settings. Our algorithm first searches for zebra crosswalks in satellite images; all candidates thus found are validated against spatially registered Google Street View images. This cascaded approach enables fast and reliable discovery and localization of zebra crosswalks in large image datasets. While fully automatic, our algorithm can be improved by a final crowdsourcing validation. To this end, we developed a Pedestrian Crossing Human Validation (PCHV) web service, which supports crowdsourcing to rule out false positives and identify false negatives.
Mind your crossings: Mining GIS imagery for crosswalk localization
Ahmetovic, Dragan; Manduchi, Roberto; Coughlan, James M.; Mascetti, Sergio
2017-01-01
For blind travelers, finding crosswalks and remaining within their borders while traversing them is a crucial part of any trip involving street crossings. While standard Orientation & Mobility (O&M) techniques allow blind travelers to safely negotiate street crossings, additional information about crosswalks and other important features at intersections would be helpful in many situations, resulting in greater safety and/or comfort during independent travel. For instance, in planning a trip a blind pedestrian may wish to be informed of the presence of all marked crossings near a desired route. We have conducted a survey of several O&M experts from the United States and Italy to determine the role that crosswalks play in travel by blind pedestrians. The results show stark differences between survey respondents from the U.S. compared with Italy: the former group emphasized the importance of following standard O&M techniques at all legal crossings (marked or unmarked), while the latter group strongly recommended crossing at marked crossings whenever possible. These contrasting opinions reflect differences in the traffic regulations of the two countries and highlight the diversity of needs that travelers in different regions may have. To address the challenges faced by blind pedestrians in negotiating street crossings, we devised a computer vision-based technique that mines existing spatial image databases for discovery of zebra crosswalks in urban settings. Our algorithm first searches for zebra crosswalks in satellite images; all candidates thus found are validated against spatially registered Google Street View images. This cascaded approach enables fast and reliable discovery and localization of zebra crosswalks in large image datasets. While fully automatic, our algorithm can be improved by a final crowdsourcing validation. To this end, we developed a Pedestrian Crossing Human Validation (PCHV) web service, which supports crowdsourcing to rule out false positives and identify false negatives. PMID:28757907
Effects of 7.5% CO2 challenge in generalized anxiety disorder.
Seddon, Kate; Morris, Kelly; Bailey, Jayne; Potokar, John; Rich, Ann; Wilson, Sue; Bettica, Paolo; Nutt, David J
2011-01-01
We have previously developed a putative model of generalized anxiety disorder in healthy volunteers using a 20-minute 7.5% carbon dioxide (CO(2)) inhalation challenge. The aim of this study was to validate the 7.5% CO(2) paradigm by assessing its effects in patients with generalized anxiety disorder in a test-retest design. Twelve medication-free generalized anxiety disorder patients attended our lab for two study days. On each study day placebo (compressed air) and 7.5% CO(2) mixture were randomly administered over 20 min, at least 30 min apart, in a single blind, randomized, placebo-controlled cross-over design. Subjective ratings, cardiovascular measures and cortisol levels were collected throughout. CO(2) challenge significantly increased ratings for anxiety and other subjective symptoms associated with generalized anxiety disorder, compared with air. It also significantly increased systolic blood pressure on day 2, indicating increased autonomic arousal. There was no change between the two test days in mean anxiety rating scores, and there also appeared to be a correlation for individual scores on a number of the subjective measures. In conclusion, 20 min of 7.5% CO(2) gas inhalation increases anxiety responses in patients with generalized anxiety disorder, and this is reliable over time.
Dragomir-Daescu, Dan; Buijs, Jorn Op Den; McEligot, Sean; Dai, Yifei; Entwistle, Rachel C.; Salas, Christina; Melton, L. Joseph; Bennet, Kevin E.; Khosla, Sundeep; Amin, Shreyasee
2013-01-01
Clinical implementation of quantitative computed tomography-based finite element analysis (QCT/FEA) of proximal femur stiffness and strength to assess the likelihood of proximal femur (hip) fractures requires a unified modeling procedure, consistency in predicting bone mechanical properties, and validation with realistic test data that represent typical hip fractures, specifically, a sideways fall on the hip. We, therefore, used two sets (n = 9, each) of cadaveric femora with bone densities varying from normal to osteoporotic to build, refine, and validate a new class of QCT/FEA models for hip fracture under loading conditions that simulate a sideways fall on the hip. Convergence requirements of finite element models of the first set of femora led to the creation of a new meshing strategy and a robust process to model proximal femur geometry and material properties from QCT images. We used a second set of femora to cross-validate the model parameters derived from the first set. Refined models were validated experimentally by fracturing femora using specially designed fixtures, load cells, and high speed video capture. CT image reconstructions of fractured femora were created to classify the fractures. The predicted stiffness (cross-validation R2 = 0.87), fracture load (cross-validation R2 = 0.85), and fracture patterns (83% agreement) correlated well with experimental data. PMID:21052839
Cabrera-Pivaral, Carlos E; Gutiérrez-Ruvalcaba, Clara Luz; Peralta-Heredia, Irma Concepción; Alonso-Reynoso, Carlos
2008-01-01
The purpose of this work was to measure family physicians' clinical aptitude for the diagnosis and treatment of metabolic syndrome in a representative sample from six Family Medicine Units (UMF) at the Mexican Institute for Social Security (IMSS), in Guadalajara, Jalisco, México. This is a cross-sectional study. A validated and structured instrument was used, with a confidence coefficient (Kuder-Richardson) of 0.95, that was applied to a representative sample of 90 family physicians throughout six UMFs in Guadalajara, between 2003 and 2004. Mann-Whitney's U and Kruskal-Wallis' tests were used to compare two or more groups, and the Perez-Viniegra Test was used to define aptitude development levels. No statistically significant differences were found in aptitude development between the six family medicine units groups and other comparative groups. The generally low level of clinical aptitude, and its indicators, reflects limitations on the part of family physicians at the IMSS in Jalisco to identify and manage metabolic syndrome.
Psychometric Evaluation of the MMPI-2/MMPI-2-RF Restructured Clinical Scales in an Israeli Sample.
Shkalim, Eleanor
2015-10-01
The current study cross-culturally evaluated the psychometric properties of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2)/MMPI-2-Restructured Form Restructured Clinical (RC) Scales in psychiatric settings in Israel with a sample of 100 men and 133 women. Participants were administered the MMPI-2 and were rated by their therapists on a 188-item Patient Description Form. Results indicated that in most instances the RC Scales demonstrated equivalent or better internal consistencies and improved intercorrelation patterns relative to their clinical counterparts. Furthermore, external analyses revealed comparable or improved convergent validity (with the exceptions of Antisocial Behavior [RC4] and Ideas of Persecution [RC6] among men), and mostly greater discriminant validity. Overall, the findings indicate that consistent with previous findings, the RC Scales generally exhibit comparable to improved psychometric properties over the Clinical Scales. Implications of the results, limitations, and recommendations for future research are discussed. © The Author(s) 2014.
Effective prediction of biodiversity in tidal flat habitats using an artificial neural network.
Yoo, Jae-Won; Lee, Yong-Woo; Lee, Chang-Gun; Kim, Chang-Soo
2013-02-01
Accurate predictions of benthic macrofaunal biodiversity greatly benefit the efficient planning and management of habitat restoration efforts in tidal flat habitats. Artificial neural network (ANN) prediction models for such biodiversity were developed and tested based on 13 biophysical variables, collected from 50 sites of tidal flats along the coast of Korea during 1991-2006. The developed model showed high predictions during training, cross-validation and testing. Besides the training and testing procedures, an independent dataset from a different time period (2007-2010) was used to test the robustness and practical usage of the model. High prediction on the independent dataset (r = 0.84) validated the networks proper learning of predictive relationship and its generality. Key influential variables identified by follow-up sensitivity analyses were related with topographic dimension, environmental heterogeneity, and water column properties. Study demonstrates the successful application of ANN for the accurate prediction of benthic macrofaunal biodiversity and understanding of dynamics of candidate variables. Copyright © 2012 Elsevier Ltd. All rights reserved.