Scale-Dependent Stiffness and Internal Tension of a Model Brush Polymer

NASA Astrophysics Data System (ADS)

Berezney, John P.; Marciel, Amanda B.; Schroeder, Charles M.; Saleh, Omar A.

2017-09-01

Bottle-brush polymers exhibit closely grafted side chains that interact by steric repulsion, thereby causing stiffening of the main polymer chain. We use single-molecule elasticity measurements of model brush polymers to quantify this effect. We find that stiffening is only significant on long length scales, with the main chain retaining flexibility on short scales. From the elasticity data, we extract an estimate of the internal tension generated by side-chain repulsion; this estimate is consistent with the predictions of blob-based scaling theories.

Reliability Estimation When a Test Is Split into Two Parts of Unknown Effective Length.

ERIC Educational Resources Information Center

Feldt, Leonard S.

2002-01-01

Considers the situation in which content or administrative considerations limit the way in which a test can be partitioned to estimate the internal consistency reliability of the total test score. Demonstrates that a single-valued estimate of the total score reliability is possible only if an assumption is made about the comparative size of the…

Alternative Estimates of the Reliability of College Grade Point Averages. Professional File. Article 130, Spring 2013

ERIC Educational Resources Information Center

Saupe, Joe L.; Eimers, Mardy T.

2013-01-01

The purpose of this paper is to explore differences in the reliabilities of cumulative college grade point averages (GPAs), estimated for unweighted and weighted, one-semester, 1-year, 2-year, and 4-year GPAs. Using cumulative GPAs for a freshman class at a major university, we estimate internal consistency (coefficient alpha) reliabilities for…

Career Adapt-Abilities Scale--Brazilian Form: Psychometric Properties and Relationships to Personality

ERIC Educational Resources Information Center

Teixeira, Marco Antonio Pereira; Bardagi, Marucia Patta; Lassance, Maria Celia Pacheco; Magalhaes, Mauro de Oliveira; Duarte, Maria Eduarda

2012-01-01

The Career Adapt-Abilities Scale--Brazilian Form (CAASBrazil) consists of four scales which measure concern, control, curiosity, and confidence as psychosocial resources for managing occupational transitions, developmental tasks, and work traumas. Internal consistency estimates for the subscale and total scores ranged from good to excellent. The…

Influences on and Limitations of Classical Test Theory Reliability Estimates.

ERIC Educational Resources Information Center

Arnold, Margery E.

It is incorrect to say "the test is reliable" because reliability is a function not only of the test itself, but of many factors. The present paper explains how different factors affect classical reliability estimates such as test-retest, interrater, internal consistency, and equivalent forms coefficients. Furthermore, the limits of classical test…

Estimating the Reliability of Single-Item Life Satisfaction Measures: Results from Four National Panel Studies

ERIC Educational Resources Information Center

Lucas, Richard E.; Donnellan, M. Brent

2012-01-01

Life satisfaction is often assessed using single-item measures. However, estimating the reliability of these measures can be difficult because internal consistency coefficients cannot be calculated. Existing approaches use longitudinal data to isolate occasion-specific variance from variance that is either completely stable or variance that…

Reliability Generalization of the Psychopathy Checklist Applied in Youthful Samples

ERIC Educational Resources Information Center

Campbell, Justin S.; Pulos, Steven; Hogan, Mike; Murry, Francie

2005-01-01

This study examines the average reliability of Hare Psychopathy Checklists (PCLs) adapted for use in samples of youthful offenders (aged 12 to 21 years). Two forms of reliability are examined: 18 alpha estimates of internal consistency and 18 intraclass correlation (two or more raters) estimates of interrater reliability. The results, an average…

Processes and Procedures for Estimating Score Reliability and Precision

ERIC Educational Resources Information Center

Bardhoshi, Gerta; Erford, Bradley T.

2017-01-01

Precision is a key facet of test development, with score reliability determined primarily according to the types of error one wants to approximate and demonstrate. This article identifies and discusses several primary forms of reliability estimation: internal consistency (i.e., split-half, KR-20, a), test-retest, alternate forms, interscorer, and…

The Riso-Hudson Enneagram Type Indicator: Estimates of Reliability and Validity

ERIC Educational Resources Information Center

Newgent, Rebecca A.; Parr, Patricia E.; Newman, Isadore; Higgins, Kristin K.

2004-01-01

This investigation was conducted to estimate the reliability and validity of scores on the Riso-Hudson Enneagram Type Indicator (D. R. Riso & R. Hudson, 1999a). Results of 287 participants were analyzed. Alpha suggests an adequate degree of internal consistency. Evidence provides mixed support for construct validity using correlational and…

Career Adapt-Abilities Scale--Netherlands Form: Psychometric Properties and Relationships to Ability, Personality, and Regulatory Focus

ERIC Educational Resources Information Center

van Vianen, Annelies E. M.; Klehe, Ute-Christine; Koen, Jessie; Dries, Nicky

2012-01-01

The Career Adapt-Abilities Scale (CAAS)--Netherlands Form consists of four scales, each with six items, which measure concern, control, curiosity, and confidence as psychosocial resources for managing occupational transitions, developmental tasks, and work traumas. Internal consistency estimates for the subscale and total scores ranged from…

Career Adapt-Abilities Scale-France Form: Psychometric Properties and Relationships to Anxiety and Motivation

ERIC Educational Resources Information Center

Pouyaud, Jacques; Vignoli, Emmanuelle; Dosnon, Odile; Lallemand, Noelle

2012-01-01

The CAAS-France Form consists of four scales, each with six items, which measure concern, control, curiosity, and confidence as psychosocial resources for managing occupational transitions, developmental tasks, and work traumas. Internal consistency estimates for the subscale and total scores ranged from moderate to good. The factor structure was…

Career Adapt-Abilities Scale--Portugal Form: Psychometric Properties and Relationships to Employment Status

ERIC Educational Resources Information Center

Duarte, M. Eduarda; Soares, M. C.; Fraga, S.; Rafael, M.; Lima, M. R.; Paredes, I.; Agostinho, R.; Djalo, A.

2012-01-01

The Career-Adaptabilities Scale (CAAS)--Portugal Form consists of four scales, each with seven items, which measure concern, control, curiosity, and confidence as psychosocial resources for managing occupational transitions, developmental tasks, and work traumas. Internal consistency estimates for the subscale and total scores ranged from good to…

Towards a sampling strategy for the assessment of forest condition at European level: combining country estimates.

PubMed

Travaglini, Davide; Fattorini, Lorenzo; Barbati, Anna; Bottalico, Francesca; Corona, Piermaria; Ferretti, Marco; Chirici, Gherardo

2013-04-01

A correct characterization of the status and trend of forest condition is essential to support reporting processes at national and international level. An international forest condition monitoring has been implemented in Europe since 1987 under the auspices of the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests). The monitoring is based on harmonized methodologies, with individual countries being responsible for its implementation. Due to inconsistencies and problems in sampling design, however, the ICP Forests network is not able to produce reliable quantitative estimates of forest condition at European and sometimes at country level. This paper proposes (1) a set of requirements for status and change assessment and (2) a harmonized sampling strategy able to provide unbiased and consistent estimators of forest condition parameters and of their changes at both country and European level. Under the assumption that a common definition of forest holds among European countries, monitoring objectives, parameters of concern and accuracy indexes are stated. On the basis of fixed-area plot sampling performed independently in each country, an unbiased and consistent estimator of forest defoliation indexes is obtained at both country and European level, together with conservative estimators of their sampling variance and power in the detection of changes. The strategy adopts a probabilistic sampling scheme based on fixed-area plots selected by means of systematic or stratified schemes. Operative guidelines for its application are provided.

Development and Validation of a Coping with Discrimination Scale: Factor Structure, Reliability, and Validity

ERIC Educational Resources Information Center

Wei, Meifen; Alvarez, Alvin N.; Ku, Tsun-Yao; Russell, Daniel W.; Bonett, Douglas G.

2010-01-01

Four studies were conducted to develop and validate the Coping With Discrimination Scale (CDS). In Study 1, an exploratory factor analysis (N = 328) identified 5 factors: Education/Advocacy, Internalization, Drug and Alcohol Use, Resistance, and Detachment, with internal consistency reliability estimates ranging from 0.72 to 0.90. In Study 2, a…

Locus of Control and Likelihood of Nuclear War: Two Studies.

ERIC Educational Resources Information Center

Erdahl, Paul; Rounds, James B.

The Nuclear Locus of Control (NLOC) scales were constructed to assess beliefs as to whether nuclear war and nuclear policy decisions are, or can be, influenced by oneself, powerful others, or chance. Three scales measuring internal, powerful others, and chance nuclear LOC show internal consistency estimates (Cronbach's Alpha) of .87, .76, and .85,…

Reliability of the Raven Coloured Progressive Matrices for Anglo and for Mexican-American Children.

ERIC Educational Resources Information Center

Valencia, Richard R.

1984-01-01

Investigated the internal consistency reliability estimates of the Raven Coloured Progressive Matrices (CPM) for 96 Anglo and Mexican American third-grade boys from low socioeconomic status background. The results showed that the reliability estimates of the CPM for the two ethnic groups were acceptably high and extremely similar in magnitude.…

Evaluating direct medical expenditures estimation methods of adults using the medical expenditure panel survey: an example focusing on head and neck cancer.

PubMed

Coughlan, Diarmuid; Yeh, Susan T; O'Neill, Ciaran; Frick, Kevin D

2014-01-01

To inform policymakers of the importance of evaluating various methods for estimating the direct medical expenditures for a low-incidence condition, head and neck cancer (HNC). Four methods of estimation have been identified: 1) summing all health care expenditures, 2) estimating disease-specific expenditures consistent with an attribution approach, 3) estimating disease-specific expenditures by matching, and 4) estimating disease-specific expenditures by using a regression-based approach. A literature review of studies (2005-2012) that used the Medical Expenditure Panel Survey (MEPS) was undertaken to establish the most popular expenditure estimation methods. These methods were then applied to a sample of 120 respondents with HNC, derived from pooled data (2003-2008). The literature review shows that varying expenditure estimation methods have been used with MEPS but no study compared and contrasted all four methods. Our estimates are reflective of the national treated prevalence of HNC. The upper-bound estimate of annual direct medical expenditures of adult respondents with HNC between 2003 and 2008 was $3.18 billion (in 2008 dollars). Comparable estimates arising from methods focusing on disease-specific and incremental expenditures were all lower in magnitude. Attribution yielded annual expenditures of $1.41 billion, matching method of $1.56 billion, and regression method of $1.09 billion. This research demonstrates that variation exists across and within expenditure estimation methods applied to MEPS data. Despite concerns regarding aspects of reliability and consistency, reporting a combination of the four methods offers a degree of transparency and validity to estimating the likely range of annual direct medical expenditures of a condition. © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Published by International Society for Pharmacoeconomics and Outcomes Research (ISPOR) All rights reserved.

Study samples are too small to produce sufficiently precise reliability coefficients.

PubMed

Charter, Richard A

2003-04-01

In a survey of journal articles, test manuals, and test critique books, the author found that a mean sample size (N) of 260 participants had been used for reliability studies on 742 tests. The distribution was skewed because the median sample size for the total sample was only 90. The median sample sizes for the internal consistency, retest, and interjudge reliabilities were 182, 64, and 36, respectively. The author presented sample size statistics for the various internal consistency methods and types of tests. In general, the author found that the sample sizes that were used in the internal consistency studies were too small to produce sufficiently precise reliability coefficients, which in turn could cause imprecise estimates of examinee true-score confidence intervals. The results also suggest that larger sample sizes have been used in the last decade compared with those that were used in earlier decades.

Internal Consistency and Associated Characteristics of Informant Discrepancies in Clinic Referred Youths Age 11 to 17 Years

PubMed Central

De Los Reyes, Andres; Youngstrom, Eric A.; Pabón, Shairy C.; Youngstrom, Jennifer K.; Feeny, Norah C.; Findling, Robert L.

2011-01-01

In this study, we examined the internal consistency of informant discrepancies in reports of youth behavior and emotional problems and their unique relations with youth, caregiver, and family characteristics. In a heterogeneous multisite clinic sample of 420 youths (ages 11 to 17 years), high internal consistency estimates were observed across measures of informant discrepancies. Further, latent profile analyses identified systematic patterns of discrepancies, characterized by their magnitude and direction (i.e., which informant reported greater youth problems). Additionally, informant discrepancies systematically and uniquely related to informants' own perspectives of youth mood problems, and these relations remained significant after taking into account multiple informants' reports of informant characteristics widely known to relate to informant discrepancies. These findings call into the question the prevailing view of informant discrepancies as indicative of unreliability and/or bias on the part of informants' reports of youths' behavior. PMID:21229442

The reliability and internal consistency of one-shot and flicker change detection for measuring individual differences in visual working memory capacity.

PubMed

Pailian, Hrag; Halberda, Justin

2015-04-01

We investigated the psychometric properties of the one-shot change detection task for estimating visual working memory (VWM) storage capacity-and also introduced and tested an alternative flicker change detection task for estimating these limits. In three experiments, we found that the one-shot whole-display task returns estimates of VWM storage capacity (K) that are unreliable across set sizes-suggesting that the whole-display task is measuring different things at different set sizes. In two additional experiments, we found that the one-shot single-probe variant shows improvements in the reliability and consistency of K estimates. In another additional experiment, we found that a one-shot whole-display-with-click task (requiring target localization) also showed improvements in reliability and consistency. The latter results suggest that the one-shot task can return reliable and consistent estimates of VWM storage capacity (K), and they highlight the possibility that the requirement to localize the changed target is what engenders this enhancement. Through a final series of four experiments, we introduced and tested an alternative flicker change detection method that also requires the observer to localize the changing target and that generates, from response times, an estimate of VWM storage capacity (K). We found that estimates of K from the flicker task correlated with estimates from the traditional one-shot task and also had high reliability and consistency. We highlight the flicker method's ability to estimate executive functions as well as VWM storage capacity, and discuss the potential for measuring multiple abilities with the one-shot and flicker tasks.

Internal and temporal reliability estimates for informant ratings of personality using the NEO PI-R and IAS. NEO Personality Inventory. Interpersonal Adjective Scales.

PubMed

Kurtz, J E; Lee, P A; Sherker, J L

1999-06-01

This study examines the internal consistency and temporal stability of informant ratings from two widely used instruments for normal personality assessment, the revised NEO Personality Inventory (NEO PI-R) and the Interpersonal Adjective Scales (IAS). Well-known adult targets were selected by 109 undergraduate students and rated on two occasions separated by a 6-month interval. With few exceptions, estimates of internal consistency are adequate to good for both instruments. NEO PI-R domain scores yield coefficient alphas ranging from .89 to .96, with a median of .80 for the 30 facet scales. IAS octant scales show coefficient alphas ranging from .83 to .92. Retest Pearson correlations are above .70 for each of the NEO PI-R domain scores and both IAS axis coordinates, and intraclass correlations are above .60 for all scales from both instruments. Score changes were small but statistically significant for three of the five NEO PI-R domains at retest. The retest stability of IAS type classifications varies as a function of the extremity of the associated octant scores.

Observed and Projected Changes to the Precipitation Annual Cycle

DOE PAGES

Marvel, Kate; Biasutti, Michela; Bonfils, Celine; ...

2017-06-08

Anthropogenic climate change is predicted to cause spatial and temporal shifts in precipitation patterns. These may be apparent in changes to the annual cycle of zonal mean precipitation P. Trends in the amplitude and phase of the P annual cycle in two long-term, global satellite datasets are broadly similar. Model-derived fingerprints of externally forced changes to the amplitude and phase of the P seasonal cycle, combined with these observations, enable a formal detection and attribution analysis. Observed amplitude changes are inconsistent with model estimates of internal variability but not attributable to the model-predicted response to external forcing. This mismatch betweenmore » observed and predicted amplitude changes is consistent with the sustained La Niña–like conditions that characterize the recent slowdown in the rise of the global mean temperature. However, observed changes to the annual cycle phase do not seem to be driven by this recent hiatus. Furthermore these changes are consistent with model estimates of forced changes, are inconsistent (in one observational dataset) with estimates of internal variability, and may suggest the emergence of an externally forced signal.« less

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

Marvel, Kate; Biasutti, Michela; Bonfils, Celine

Anthropogenic climate change is predicted to cause spatial and temporal shifts in precipitation patterns. These may be apparent in changes to the annual cycle of zonal mean precipitation P. Trends in the amplitude and phase of the P annual cycle in two long-term, global satellite datasets are broadly similar. Model-derived fingerprints of externally forced changes to the amplitude and phase of the P seasonal cycle, combined with these observations, enable a formal detection and attribution analysis. Observed amplitude changes are inconsistent with model estimates of internal variability but not attributable to the model-predicted response to external forcing. This mismatch betweenmore » observed and predicted amplitude changes is consistent with the sustained La Niña–like conditions that characterize the recent slowdown in the rise of the global mean temperature. However, observed changes to the annual cycle phase do not seem to be driven by this recent hiatus. Furthermore these changes are consistent with model estimates of forced changes, are inconsistent (in one observational dataset) with estimates of internal variability, and may suggest the emergence of an externally forced signal.« less

Estimating Limit Reference Points for Western Pacific Leatherback Turtles (Dermochelys coriacea) in the U.S. West Coast EEZ

PubMed Central

Curtis, K. Alexandra; Moore, Jeffrey E.; Benson, Scott R.

2015-01-01

Biological limit reference points (LRPs) for fisheries catch represent upper bounds that avoid undesirable population states. LRPs can support consistent management evaluation among species and regions, and can advance ecosystem-based fisheries management. For transboundary species, LRPs prorated by local abundance can inform local management decisions when international coordination is lacking. We estimated LRPs for western Pacific leatherbacks in the U.S. West Coast Exclusive Economic Zone (WCEEZ) using three approaches with different types of information on local abundance. For the current application, the best-informed LRP used a local abundance estimate derived from nest counts, vital rate information, satellite tag data, and fishery observer data, and was calculated with a Potential Biological Removal estimator. Management strategy evaluation was used to set tuning parameters of the LRP estimators to satisfy risk tolerances for falling below population thresholds, and to evaluate sensitivity of population outcomes to bias in key inputs. We estimated local LRPs consistent with three hypothetical management objectives: allowing the population to rebuild to its maximum net productivity level (4.7 turtles per five years), limiting delay of population rebuilding (0.8 turtles per five years), or only preventing further decline (7.7 turtles per five years). These LRPs pertain to all human-caused removals and represent the WCEEZ contribution to meeting population management objectives within a broader international cooperative framework. We present multi-year estimates, because at low LRP values, annual assessments are prone to substantial error that can lead to volatile and costly management without providing further conservation benefit. The novel approach and the performance criteria used here are not a direct expression of the “jeopardy” standard of the U.S. Endangered Species Act, but they provide useful assessment information and could help guide international management frameworks. Given the range of abundance data scenarios addressed, LRPs should be estimable for many other areas, populations, and taxa. PMID:26368557

Estimating Limit Reference Points for Western Pacific Leatherback Turtles (Dermochelys coriacea) in the U.S. West Coast EEZ.

PubMed

Curtis, K Alexandra; Moore, Jeffrey E; Benson, Scott R

2015-01-01

Biological limit reference points (LRPs) for fisheries catch represent upper bounds that avoid undesirable population states. LRPs can support consistent management evaluation among species and regions, and can advance ecosystem-based fisheries management. For transboundary species, LRPs prorated by local abundance can inform local management decisions when international coordination is lacking. We estimated LRPs for western Pacific leatherbacks in the U.S. West Coast Exclusive Economic Zone (WCEEZ) using three approaches with different types of information on local abundance. For the current application, the best-informed LRP used a local abundance estimate derived from nest counts, vital rate information, satellite tag data, and fishery observer data, and was calculated with a Potential Biological Removal estimator. Management strategy evaluation was used to set tuning parameters of the LRP estimators to satisfy risk tolerances for falling below population thresholds, and to evaluate sensitivity of population outcomes to bias in key inputs. We estimated local LRPs consistent with three hypothetical management objectives: allowing the population to rebuild to its maximum net productivity level (4.7 turtles per five years), limiting delay of population rebuilding (0.8 turtles per five years), or only preventing further decline (7.7 turtles per five years). These LRPs pertain to all human-caused removals and represent the WCEEZ contribution to meeting population management objectives within a broader international cooperative framework. We present multi-year estimates, because at low LRP values, annual assessments are prone to substantial error that can lead to volatile and costly management without providing further conservation benefit. The novel approach and the performance criteria used here are not a direct expression of the "jeopardy" standard of the U.S. Endangered Species Act, but they provide useful assessment information and could help guide international management frameworks. Given the range of abundance data scenarios addressed, LRPs should be estimable for many other areas, populations, and taxa.

The Brazilian version of the effort-reward imbalance questionnaire to assess job stress.

PubMed

Chor, Dóra; Werneck, Guilherme Loureiro; Faerstein, Eduardo; Alves, Márcia Guimarães de Mello; Rotenberg, Lúcia

2008-01-01

The effort-reward imbalance (ERI) model has been used to assess the health impact of job stress. We aimed at describing the cross-cultural adaptation of the ERI questionnaire into Portuguese and some psychometric properties, in particular internal consistency, test-retest reliability, and factorial structure. We developed a Brazilian version of the ERI using a back-translation method and tested its reliability. The test-retest reliability study was conducted with 111 health workers and University staff. The current analyses are based on 89 participants, after exclusion of those with missing data. Reproducibility (interclass correlation coefficients) for the "effort", "'reward", and "'overcommitment"' dimensions of the scale was estimated at 0.76, 0.86, and 0.78, respectively. Internal consistency (Cronbach's alpha) estimates for these same dimensions were 0.68, 0.78, and 0.78, respectively. The exploratory factorial structure was fairly consistent with the model's theoretical components. We conclude that the results of this study represent the first evidence in favor of the application of the Brazilian Portuguese version of the ERI scale in health research in populations with similar socioeconomic characteristics.

Estimation and classification by sigmoids based on mutual information

NASA Technical Reports Server (NTRS)

Baram, Yoram

1994-01-01

An estimate of the probability density function of a random vector is obtained by maximizing the mutual information between the input and the output of a feedforward network of sigmoidal units with respect to the input weights. Classification problems can be solved by selecting the class associated with the maximal estimated density. Newton's s method, applied to an estimated density, yields a recursive maximum likelihood estimator, consisting of a single internal layer of sigmoids, for a random variable or a random sequence. Applications to the diamond classification and to the prediction of a sun-spot process are demonstrated.

Measurement Myths and Misconceptions.

ERIC Educational Resources Information Center

Goodwin, Laura D.; Goodwin, William L.

1999-01-01

Presents frequently encountered measurement misconceptions and various measurement "rules." Origins of the misconceptions and rules are described, along with the reasons why they are problematic. Alternate approaches or considerations are given. Misconceptions discussed pertain to the estimation of internal consistency reliability and item…

Regional Development Impacts Multi-Regional - Multi-Industry Model (MRMI) Users Manual,

DTIC Science & Technology

1982-09-01

indicators, described in Chapter 2, are estimated as well. Finally, MRMI is flexible, as it can incorporate alternative macroeconomic , national inter...national and regional economic contexts and data sources for estimating macroeconomic and direct impacts data. Considerations for ensuring consistency...Chapter 4 is devoted to model execution and the interpretation of its output. As MRMI forecasts are based upon macroeconomic , national inter-industry

Satellite Power Systems (SPS) space transportation cost analysis and evaluation

NASA Technical Reports Server (NTRS)

1980-01-01

A picture of Space Power Systems space transportation costs at the present time is given with respect to accuracy as stated, reasonableness of the methods used, assumptions made, and uncertainty associated with the estimates. The approach used consists of examining space transportation costs from several perspectives to perform a variety of sensitivity analyses or reviews and examine the findings in terms of internal consistency and external comparison with analogous systems. These approaches are summarized as a theoretical and historical review including a review of stated and unstated assumptions used to derive the costs, and a performance or technical review. These reviews cover the overall transportation program as well as the individual vehicles proposed. The review of overall cost assumptions is the principal means used for estimating the cost uncertainty derived. The cost estimates used as the best current estimate are included.

Reliability of the ecSatter Inventory as a tool to measure eating competence.

PubMed

Stotts, Jodi L; Lohse, Barbara

2007-01-01

To examine the reliability of the ecSatter Inventory (ecSI), a measure of eating competence. Self-report questionnaires were administered in person or by mail. Retesting occurred 2 to 6 weeks after completion of the first questionnaire. Both administrations of the questionnaire were completed by 259 participants who were mostly food secure, white females with some college education; mean age was 26.9 +/- 10.4 years. Test-retest reliability and internal consistency. Spearman's rank correlation coefficients to estimate test-retest reliability and Cronbach alpha coefficients to estimate internal consistency. Spearman's rank correlation coefficient for ecSI total score was 0.68; subscale coefficients were 0.70 for eating attitudes, 0.70 for contextual skills, 0.65 for food acceptance, and 0.52 for internal regulation. Cronbach alpha coefficient for ecSI total score was 0.77. Subscale alphas coefficients were 0.80 for eating attitudes, 0.69 for contextual skills, 0.68 for food acceptance, and 0.66 for internal regulation. This study provides psychometric evidence about the reliability of ecSI as a measure of eating competence in this sample. Although some ecSI items may require revision, results suggest that the instrument may be used to evaluate nutrition education designed to improve eating competence.

Test-retest reliability and construct validity of the Helplessness, Hopelessness, and Haplessness Scale in patients with anxiety disorders.

PubMed

Vatan, Sevginar; Ertaş, Sedar; Lester, David

2011-04-01

In a sample of 100 Turkish psychiatric patients with diagnoses of anxiety disorders, Lester's Helplessness, Hopelessness, and Haplessness inventory had moderate estimates of internal consistency, test-retest reliability, and construct validity.

Effects of Ensemble Configuration on Estimates of Regional Climate Uncertainties

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

Goldenson, N.; Mauger, G.; Leung, L. R.

Internal variability in the climate system can contribute substantial uncertainty in climate projections, particularly at regional scales. Internal variability can be quantified using large ensembles of simulations that are identical but for perturbed initial conditions. Here we compare methods for quantifying internal variability. Our study region spans the west coast of North America, which is strongly influenced by El Niño and other large-scale dynamics through their contribution to large-scale internal variability. Using a statistical framework to simultaneously account for multiple sources of uncertainty, we find that internal variability can be quantified consistently using a large ensemble or an ensemble ofmore » opportunity that includes small ensembles from multiple models and climate scenarios. The latter also produce estimates of uncertainty due to model differences. We conclude that projection uncertainties are best assessed using small single-model ensembles from as many model-scenario pairings as computationally feasible, which has implications for ensemble design in large modeling efforts.« less

Psychometric Evaluation of the D-Catch, an Instrument to Measure the Accuracy of Nursing Documentation.

PubMed

D'Agostino, Fabio; Barbaranelli, Claudio; Paans, Wolter; Belsito, Romina; Juarez Vela, Raul; Alvaro, Rosaria; Vellone, Ercole

2017-07-01

To evaluate the psychometric properties of the D-Catch instrument. A cross-sectional methodological study. Validity and reliability were estimated with confirmatory factor analysis (CFA) and internal consistency and inter-rater reliability, respectively. A sample of 250 nursing documentations was selected. CFA showed the adequacy of a 1-factor model (chronologically descriptive accuracy) with an outlier item (nursing diagnosis accuracy). Internal consistency and inter-rater reliability were adequate. The D-Catch is a valid and reliable instrument for measuring the accuracy of nursing documentation. Caution is needed when measuring diagnostic accuracy since only one item measures this dimension. The D-Catch can be used as an indicator of the accuracy of nursing documentation and the quality of nursing care. © 2015 NANDA International, Inc.

Factor Structure, Internal Consistency, and Screening Sensitivity of the GARS-2 in a Developmental Disabilities Sample

PubMed Central

Volker, Martin A.; Dua, Elissa H.; Lopata, Christopher; Thomeer, Marcus L.; Toomey, Jennifer A.; Smerbeck, Audrey M.; Rodgers, Jonathan D.; Popkin, Joshua R.; Nelson, Andrew T.; Lee, Gloria K.

2016-01-01

The Gilliam Autism Rating Scale-Second Edition (GARS-2) is a widely used screening instrument that assists in the identification and diagnosis of autism. The purpose of this study was to examine the factor structure, internal consistency, and screening sensitivity of the GARS-2 using ratings from special education teaching staff for a sample of 240 individuals with autism or other significant developmental disabilities. Exploratory factor analysis yielded a correlated three-factor solution similar to that found in 2005 by Lecavalier for the original GARS. Though the three factors appeared to be reasonably consistent with the intended constructs of the three GARS-2 subscales, the analysis indicated that more than a third of the GARS-2 items were assigned to the wrong subscale. Internal consistency estimates met or exceeded standards for screening and were generally higher than those in previous studies. Screening sensitivity was .65 and specificity was .81 for the Autism Index using a cut score of 85. Based on these findings, recommendations are made for instrument revision. PMID:26981279

[Validating the Spanish version of the Nursing Activities Score].

PubMed

Sánchez-Sánchez, M M; Arias-Rivera, S; Fraile-Gamo, M P; Thuissard-Vasallo, I J; Frutos-Vivar, F

2015-01-01

Validating workload scores ensures that they are appropriate for the purpose for which they were developed. To validate the Nursing Activities Score (NAS) Spanish version. Observational and prospective study. 1,045 patients who were admitted to a medical-surgical unit and a serious burns unit in 2006 were included. The nurse in charge assessed patient workloads by Nine Equivalent of Nursing Manpower use Score and NAS. To assess the internal consistency of the measurements of NAS, item-test correlations, Cronbach's α and Cronbach's α corrected by omitting each of the items were calculated. The intraobserver and interobserver reliability were assessed with the intraclass correlation coefficient by viewing recordings and Kappa (interobserver reliability) was estimated. For the analysis of internal validity, a factorial principal components analysis was performed. Convergent validity was assessed using the Spearman correlation coefficient values obtained from the Nine Equivalent of Nursing Manpower use Score and Spanish-NAS scales. For internal consistency, 164 questionnaires were analysed and a Cronbach's α of 0.373 was calculated. The intraclass correlation coefficient for intraobserver reliability estimate was 0.837 (95% IC: 0.466-0.950) and 0.662 (95% IC: 0.033-0.882) for interobserver reliability. The estimated kappa was 0.371. For internal validity, exploratory factor analysis showed that the first item explained 58.9% of the variance of the questionnaire. For convergent validity 1006 questionnaires were included and a Spearman correlation coefficient of 0.746 was observed. The psychometric properties of Spanish-NAS are acceptable. Copyright © 2014 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

Development and validation of a Markov microsimulation model for the economic evaluation of treatments in osteoporosis.

PubMed

Hiligsmann, Mickaël; Ethgen, Olivier; Bruyère, Olivier; Richy, Florent; Gathon, Henry-Jean; Reginster, Jean-Yves

2009-01-01

Markov models are increasingly used in economic evaluations of treatments for osteoporosis. Most of the existing evaluations are cohort-based Markov models missing comprehensive memory management and versatility. In this article, we describe and validate an original Markov microsimulation model to accurately assess the cost-effectiveness of prevention and treatment of osteoporosis. We developed a Markov microsimulation model with a lifetime horizon and a direct health-care cost perspective. The patient history was recorded and was used in calculations of transition probabilities, utilities, and costs. To test the internal consistency of the model, we carried out an example calculation for alendronate therapy. Then, external consistency was investigated by comparing absolute lifetime risk of fracture estimates with epidemiologic data. For women at age 70 years, with a twofold increase in the fracture risk of the average population, the costs per quality-adjusted life-year gained for alendronate therapy versus no treatment were estimated at €9105 and €15,325, respectively, under full and realistic adherence assumptions. All the sensitivity analyses in terms of model parameters and modeling assumptions were coherent with expected conclusions and absolute lifetime risk of fracture estimates were within the range of previous estimates, which confirmed both internal and external consistency of the model. Microsimulation models present some major advantages over cohort-based models, increasing the reliability of the results and being largely compatible with the existing state of the art, evidence-based literature. The developed model appears to be a valid model for use in economic evaluations in osteoporosis.

Validation of the Weight Concerns Scale Applied to Brazilian University Students.

PubMed

Dias, Juliana Chioda Ribeiro; da Silva, Wanderson Roberto; Maroco, João; Campos, Juliana Alvares Duarte Bonini

2015-06-01

The aim of this study was to evaluate the validity and reliability of the Portuguese version of the Weight Concerns Scale (WCS) when applied to Brazilian university students. The scale was completed by 1084 university students from Brazilian public education institutions. A confirmatory factor analysis was conducted. The stability of the model in independent samples was assessed through multigroup analysis, and the invariance was estimated. Convergent, concurrent, divergent, and criterion validities as well as internal consistency were estimated. Results indicated that the one-factor model presented an adequate fit to the sample and values of convergent validity. The concurrent validity with the Body Shape Questionnaire and divergent validity with the Maslach Burnout Inventory for Students were adequate. Internal consistency was adequate, and the factorial structure was invariant in independent subsamples. The results present a simple and short instrument capable of precisely and accurately assessing concerns with weight among Brazilian university students. Copyright © 2015 Elsevier Ltd. All rights reserved.

Psychometric evaluation of a unified Portuguese-language version of the Body Shape Questionnaire in female university students.

PubMed

Silva, Wanderson Roberto; Costa, David; Pimenta, Filipa; Maroco, João; Campos, Juliana Alvares Duarte Bonini

2016-07-21

The objectives of this study were to develop a unified Portuguese-language version, for use in Brazil and Portugal, of the Body Shape Questionnaire (BSQ) and to estimate its validity, reliability, and internal consistency in Brazilian and Portuguese female university students. Confirmatory factor analysis was performed using both original (34-item) and shortened (8-item) versions. The model's fit was assessed with χ²/df, CFI, NFI, and RMSEA. Concurrent and convergent validity were assessed. Reliability was estimated through internal consistency and composite reliability (α). Transnational invariance of the BSQ was tested using multi-group analysis. The original 32-item model was refined to present a better fit and adequate validity and reliability. The shortened model was stable in both independent samples and in transnational samples (Brazil and Portugal). The use of this unified version is recommended for the assessment of body shape concerns in both Brazilian and Portuguese college students.

A practical comparison of algorithms for the measurement of multiscale entropy in neural time series data.

PubMed

Kuntzelman, Karl; Jack Rhodes, L; Harrington, Lillian N; Miskovic, Vladimir

2018-06-01

There is a broad family of statistical methods for capturing time series regularity, with increasingly widespread adoption by the neuroscientific community. A common feature of these methods is that they permit investigators to quantify the entropy of brain signals - an index of unpredictability/complexity. Despite the proliferation of algorithms for computing entropy from neural time series data there is scant evidence concerning their relative stability and efficiency. Here we evaluated several different algorithmic implementations (sample, fuzzy, dispersion and permutation) of multiscale entropy in terms of their stability across sessions, internal consistency and computational speed, accuracy and precision using a combination of electroencephalogram (EEG) and synthetic 1/ƒ noise signals. Overall, we report fair to excellent internal consistency and longitudinal stability over a one-week period for the majority of entropy estimates, with several caveats. Computational timing estimates suggest distinct advantages for dispersion and permutation entropy over other entropy estimates. Considered alongside the psychometric evidence, we suggest several ways in which researchers can maximize computational resources (without sacrificing reliability), especially when working with high-density M/EEG data or multivoxel BOLD time series signals. Copyright © 2018 Elsevier Inc. All rights reserved.

Testing competing forms of the Milankovitch hypothesis: A multivariate approach

NASA Astrophysics Data System (ADS)

Kaufmann, Robert K.; Juselius, Katarina

2016-02-01

We test competing forms of the Milankovitch hypothesis by estimating the coefficients and diagnostic statistics for a cointegrated vector autoregressive model that includes 10 climate variables and four exogenous variables for solar insolation. The estimates are consistent with the physical mechanisms postulated to drive glacial cycles. They show that the climate variables are driven partly by solar insolation, determining the timing and magnitude of glaciations and terminations, and partly by internal feedback dynamics, pushing the climate variables away from equilibrium. We argue that the latter is consistent with a weak form of the Milankovitch hypothesis and that it should be restated as follows: internal climate dynamics impose perturbations on glacial cycles that are driven by solar insolation. Our results show that these perturbations are likely caused by slow adjustment between land ice volume and solar insolation. The estimated adjustment dynamics show that solar insolation affects an array of climate variables other than ice volume, each at a unique rate. This implies that previous efforts to test the strong form of the Milankovitch hypothesis by examining the relationship between solar insolation and a single climate variable are likely to suffer from omitted variable bias.

A reliability generalization meta-analysis of coefficient alpha and test-retest coefficient for the aging males' symptoms (AMS) scale.

PubMed

Lee, Chin-Pang; Chiu, Yu-Wen; Chu, Chun-Lin; Chen, Yu; Jiang, Kun-Hao; Chen, Jiun-Liang; Chen, Ching-Yen

2016-12-01

The aging males' symptoms (AMS) scale is an instrument used to determine the health-related quality of life in adult and elderly men. The purpose of this study was to synthesize internal consistency (Cronbach's alpha) and test-retest reliability for the AMS scale and its three subscales. Of the 123 studies reviewed, 12 provided alpha coefficients which were then used in the meta-analyses of internal consistency. Seven of the 12 included studies provided test-retest coefficients, and these were used in the meta-analyses of test-retest reliability. The AMS scale had excellent internal consistency [α = 0.89 (95% CI 0.88-0.90)]; the mean alpha estimates across the AMS subscales ranged from 0.79 to 0.82. The AMS scale also had good test-retest reliability [r = 0.85 (95% CI 0.82-0.88]; the test-retest reliability coefficients of the AMS subscales ranged from 0.76 to 0.83. There was significant heterogeneity among the included studies. The AMS scale and the three subscales had fairly good internal consistency and test-retest reliability. Future psychometric studies of the AMS scale should report important characteristics of the participants, details of item scores, and test-retest reliability.

The brief multidimensional students' life satisfaction scale-college version.

PubMed

Zullig, Keith J; Huebner, E Scott; Patton, Jon M; Murray, Karen A

2009-01-01

To investigate the psychometric properties of the BMSLSS-College among 723 college students. Internal consistency estimates explored scale reliability, factor analysis explored construct validity, and known-groups validity was assessed using the National College Youth Risk Behavior Survey and Harvard School of Public Health College Alcohol Study. Criterion-related validity was explored through analyses with the CDC's health-related quality of life scale and a social isolation scale. Acceptable internal consistency reliability, construct, known-groups, and criterion-related validity were established. Findings offer preliminary support for the BMSLSS-C; it could be useful in large-scale research studies, applied screening contexts, and for program evaluation purposes toward achieving Healthy People 2010 objectives.

On a self-consistent representation of earth models, with an application to the computing of internal flattening

NASA Astrophysics Data System (ADS)

Denis, C.; Ibrahim, A.

Self-consistent parametric earth models are discussed in terms of a flexible numerical code. The density profile of each layer is represented as a polynomial, and figures of gravity, mass, mean density, hydrostatic pressure, and moment of inertia are derived. The polynomial representation also allows computation of the first order flattening of the internal strata of some models, using a Gauss-Legendre quadrature with a rapidly converging iteration technique. Agreement with measured geophysical data is obtained, and algorithm for estimation of the geometric flattening for any equidense surface identified by its fractional radius is developed. The program can also be applied in studies of planetary and stellar models.

Development and application of a rat PBPK model to elucidate kidney and liver effects induced by ETBE and tert-butanol

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

Salazar, Keith D., E-mail: Salazar.keith@epa.gov; Brinkerhoff, Christopher J., E-mail: Brinkerhoff.Chris@epa.gov; Lee, Janice S., E-mail: Lee.JaniceS@epa.gov

Subchronic and chronic studies in rats of the gasoline oxygenates ethyl tert-butyl ether (ETBE) and tert-butanol (TBA) report similar noncancer kidney and liver effects but differing results with respect to kidney and liver tumors. Because TBA is a major metabolite of ETBE, it is possible that TBA is the active toxic moiety in all these studies, with reported differences due simply to differences in the internal dose. To test this hypothesis, a physiologically-based pharmacokinetic (PBPK) model was developed for ETBE and TBA to calculate internal dosimetrics of TBA following either TBA or ETBE exposure. This model, based on earlier PBPKmore » models of methyl tert-butyl ether (MTBE), was used to evaluate whether kidney and liver effects are consistent across routes of exposure, as well as between ETBE and TBA studies, on the basis of estimated internal dose. The results demonstrate that noncancer kidney effects, including kidney weight changes, urothelial hyperplasia, and chronic progressive nephropathy (CPN), yielded consistent dose–response relationships across routes of exposure and across ETBE and TBA studies using TBA blood concentration as the dose metric. Relative liver weights were also consistent across studies on the basis of TBA metabolism, which is proportional to TBA liver concentrations. However, kidney and liver tumors were not consistent using any dose metric. These results support the hypothesis that TBA mediates the noncancer kidney and liver effects following ETBE administration; however, additional factors besides internal dose are necessary to explain the induction of liver and kidney tumors. - Highlights: • We model two metabolically-related fuel oxygenates to address toxicity data gaps. • Kidney and liver effects are compared on an internal dose basis. • Noncancer kidney effects are consistent using TBA blood concentration. • Liver weight changes are consistent using TBA metabolic rate. • Kidney and liver tumors are not consistent using any internal dose metric.« less

Score Reliability of Adolescent Alcohol Screening Measures: A Meta-Analytic Inquiry

ERIC Educational Resources Information Center

Shields, Alan L.; Campfield, Delia C.; Miller, Christopher S.; Howell, Ryan T.; Wallace, Kimberly; Weiss, Roger D.

2008-01-01

This study describes the reliability reporting practices in empirical studies using eight adolescent alcohol screening tools and characterizes and explores variability in internal consistency estimates across samples. Of 119 observed administrations of these instruments, 40 (34%) reported usable reliability information. The Personal Experience…

Coefficient Alpha and Reliability of Scale Scores

ERIC Educational Resources Information Center

Almehrizi, Rashid S.

2013-01-01

The majority of large-scale assessments develop various score scales that are either linear or nonlinear transformations of raw scores for better interpretations and uses of assessment results. The current formula for coefficient alpha (a; the commonly used reliability coefficient) only provides internal consistency reliability estimates of raw…

Gastropod shell size and architecture influence the applicability of methods used to estimate internal volume.

PubMed

Ragagnin, Marilia Nagata; Gorman, Daniel; McCarthy, Ian Donald; Sant'Anna, Bruno Sampaio; de Castro, Cláudio Campi; Turra, Alexander

2018-01-11

Obtaining accurate and reproducible estimates of internal shell volume is a vital requirement for studies into the ecology of a range of shell-occupying organisms, including hermit crabs. Shell internal volume is usually estimated by filling the shell cavity with water or sand, however, there has been no systematic assessment of the reliability of these methods and moreover no comparison with modern alternatives, e.g., computed tomography (CT). This study undertakes the first assessment of the measurement reproducibility of three contrasting approaches across a spectrum of shell architectures and sizes. While our results suggested a certain level of variability inherent for all methods, we conclude that a single measure using sand/water is likely to be sufficient for the majority of studies. However, care must be taken as precision may decline with increasing shell size and structural complexity. CT provided less variation between repeat measures but volume estimates were consistently lower compared to sand/water and will need methodological improvements before it can be used as an alternative. CT indicated volume may be also underestimated using sand/water due to the presence of air spaces visible in filled shells scanned by CT. Lastly, we encourage authors to clearly describe how volume estimates were obtained.

Estimating Facets of Psychopathy From Normal Personality Traits: A Step Toward Community Epidemiological Investigations

PubMed Central

Benning, Stephen D.; Patrick, Christopher J.; Blonigen, Daniel M.; Hicks, Brian M.; Iacono, William G.

2008-01-01

In three samples consisting of community and undergraduate men and women and incarcerated men, we examined the criterion validity of two distinct factors of psychopathy embodied in the Psychopathic Personality Inventory (PPI) as indexed by primary trait scales from the Multidimensional Personality Questionnaire (MPQ). Consistent with the PPI factors themselves, MPQ-estimated PPI-I related negatively with internalizing disorder symptoms and fearfulness and positively with thrill and adventure seeking, sociability, activity, and narcissism. MPQ-estimated PPI-II was associated negatively with socialization and positively with externalizing disorder symptoms, impulsivity, disinhibition and boredom susceptibility, and trait anxiety and negative emotionality. Additionally, PPI-I was selectively related to the interpersonal facet of Factor 1 of the Psychopathy Checklist—Revised (PCL-R), whereas PPI-II was related preferentially to Factor 2 of the PCL-R. PMID:15695739

Estimating varying coefficients for partial differential equation models.

PubMed

Zhang, Xinyu; Cao, Jiguo; Carroll, Raymond J

2017-09-01

Partial differential equations (PDEs) are used to model complex dynamical systems in multiple dimensions, and their parameters often have important scientific interpretations. In some applications, PDE parameters are not constant but can change depending on the values of covariates, a feature that we call varying coefficients. We propose a parameter cascading method to estimate varying coefficients in PDE models from noisy data. Our estimates of the varying coefficients are shown to be consistent and asymptotically normally distributed. The performance of our method is evaluated by a simulation study and by an empirical study estimating three varying coefficients in a PDE model arising from LIDAR data. © 2017, The International Biometric Society.

Developing a fatigue questionnaire for Chinese civil aviation pilots.

PubMed

Dai, Jing; Luo, Min; Hu, Wendong; Ma, Jin; Wen, Zhihong

2018-03-23

To assess the fatigue risk is an important challenge in improving flight safety in aviation industry. The aim of this study was to develop a comprehensive fatigue risk management indicators system and a fatigue questionnaire for Chinese civil aviation pilots. Participants included 74 (all males) civil aviation pilots. They finished the questionnaire in 20 minutes before a flight mission. The estimation of internal consistency with Cronbach's α and Student's t test as well as Pearson's correlation analysis were the main statistical methods. The results revealed that the fatigue questionnaire had acceptable internal consistency reliability and construct validity; there were significant differences on fatigue scores between international and domestic flight pilots. And some international flight pilots, who had taken medications as a sleep aid, had worse sleep quality than those had not. The long-endurance flight across time zones caused significant differences in circadian rhythm. The fatigue questionnaire can be used to measure Chinese civil aviation pilots' fatigue, which provided a reference for fatigue risk management system to civil aviation pilots.

Reliability and Validity of the Evidence-Based Practice Confidence (EPIC) Scale

ERIC Educational Resources Information Center

Salbach, Nancy M.; Jaglal, Susan B.; Williams, Jack I.

2013-01-01

Introduction: The reliability, minimal detectable change (MDC), and construct validity of the evidence-based practice confidence (EPIC) scale were evaluated among physical therapists (PTs) in clinical practice. Methods: A longitudinal mail survey was conducted. Internal consistency and test-retest reliability were estimated using Cronbach's alpha…

Bayesian Model Averaging for Propensity Score Analysis

ERIC Educational Resources Information Center

Kaplan, David; Chen, Jianshen

2013-01-01

The purpose of this study is to explore Bayesian model averaging in the propensity score context. Previous research on Bayesian propensity score analysis does not take into account model uncertainty. In this regard, an internally consistent Bayesian framework for model building and estimation must also account for model uncertainty. The…

Reliability Generalization of Scores on the Spielberger State-Trait Anxiety Inventory.

ERIC Educational Resources Information Center

Barnes, Laura L. B.; Harp, Diane; Jung, Woo Sik

2002-01-01

Conducted a reliability generalization study for the State-Trait Anxiety Inventory (C. Spielberger, 1983) by reviewing and classifying 816 research articles. Average reliability coefficients were acceptable for both internal consistency and test-retest reliability, but variation was present among the estimates. Other differences are discussed.…

Atmospheric Turbulence Estimates from a Pulsed Lidar

NASA Technical Reports Server (NTRS)

Pruis, Matthew J.; Delisi, Donald P.; Ahmad, Nash'at N.; Proctor, Fred H.

2013-01-01

Estimates of the eddy dissipation rate (EDR) were obtained from measurements made by a coherent pulsed lidar and compared with estimates from mesoscale model simulations and measurements from an in situ sonic anemometer at the Denver International Airport and with EDR estimates from the last observation time of the trailing vortex pair. The estimates of EDR from the lidar were obtained using two different methodologies. The two methodologies show consistent estimates of the vertical profiles. Comparison of EDR derived from the Weather Research and Forecast (WRF) mesoscale model with the in situ lidar estimates show good agreement during the daytime convective boundary layer, but the WRF simulations tend to overestimate EDR during the nighttime. The EDR estimates from a sonic anemometer located at 7.3 meters above ground level are approximately one order of magnitude greater than both the WRF and lidar estimates - which are from greater heights - during the daytime convective boundary layer and substantially greater during the nighttime stable boundary layer. The consistency of the EDR estimates from different methods suggests a reasonable ability to predict the temporal evolution of a spatially averaged vertical profile of EDR in an airport terminal area using a mesoscale model during the daytime convective boundary layer. In the stable nighttime boundary layer, there may be added value to EDR estimates provided by in situ lidar measurements.

Basic concepts in three-part quantitative assessments of undiscovered mineral resources

USGS Publications Warehouse

Singer, D.A.

1993-01-01

Since 1975, mineral resource assessments have been made for over 27 areas covering 5??106 km2 at various scales using what is now called the three-part form of quantitative assessment. In these assessments, (1) areas are delineated according to the types of deposits permitted by the geology,(2) the amount of metal and some ore characteristics are estimated using grade and tonnage models, and (3) the number of undiscovered deposits of each type is estimated. Permissive boundaries are drawn for one or more deposit types such that the probability of a deposit lying outside the boundary is negligible, that is, less than 1 in 100,000 to 1,000,000. Grade and tonnage models combined with estimates of the number of deposits are the fundamental means of translating geologists' resource assessments into a language that economists can use. Estimates of the number of deposits explicitly represent the probability (or degree of belief) that some fixed but unknown number of undiscovered deposits exist in the delineated tracts. Estimates are by deposit type and must be consistent with the grade and tonnage model. Other guidelines for these estimates include (1) frequency of deposits from well-explored areas, (2) local deposit extrapolations, (3) counting and assigning probabilities to anomalies and occurrences, (4) process constraints, (5) relative frequencies of related deposit types, and (6) area spatial limits. In most cases, estimates are made subjectively, as they are in meteorology, gambling, and geologic interpretations. In three-part assessments, the estimates are internally consistent because delineated tracts are consistent with descriptive models, grade and tonnage models are consistent with descriptive models, as well as with known deposits in the area, and estimates of number of deposits are consistent with grade and tonnage models. All available information is used in the assessment, and uncertainty is explicitly represented. ?? 1993 Oxford University Press.

Consistency of Use and Effectiveness of Household Water Treatment among Indian Households Claiming to Treat Their Water.

PubMed

Rosa, Ghislaine; Clasen, Thomas

2017-07-01

Household water treatment (HWT) can improve drinking water quality and prevent disease if used correctly and consistently by populations at risk. Current international monitoring estimates by the Joint Monitoring Programme for water and sanitation suggest that at least 1.1 billion people practice HWT. These estimates, however, are based on surveys that may overstate the level of consistent use and do not address microbial effectiveness. We sought to assess how HWT is practiced among households identified as HWT users according to these monitoring standards. After a baseline survey (urban: 189 households, rural: 210 households) to identify HWT users, 83 urban and 90 rural households were followed up for 6 weeks. Consistency of reported HWT practices was high in both urban (100%) and rural (93.3%) settings, as was availability of treated water (based on self-report) in all three sampling points (urban: 98.8%, rural: 76.0%). Nevertheless, only 13.7% of urban and 25.8% of rural households identified at baseline as users of adequate HWT had water free of thermotolerant coliforms at all three water sampling points. Our findings raise questions about the value of the data gathered through the international monitoring of HWT as predictors of water quality in the home, as well as questioning the ability of HWT, as actually practiced by vulnerable populations, to reduce exposure to waterborne diseases.

The electrical conductivity of the Earth's upper mantle as estimated from satellite measured magnetic field variations. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Didwall, E. M.

1981-01-01

Low latitude magnetic field variations (magnetic storms) caused by large fluctuations in the equatorial ring current were derived from magnetic field magnitude data obtained by OGO 2, 4, and 6 satellites over an almost 5 year period. Analysis procedures consisted of (1) separating the disturbance field into internal and external parts relative to the surface of the Earth; (2) estimating the response function which related to the internally generated magnetic field variations to the external variations due to the ring current; and (3) interpreting the estimated response function using theoretical response functions for known conductivity profiles. Special consideration is given to possible ocean effects. A temperature profile is proposed using conductivity temperature data for single crystal olivine. The resulting temperature profile is reasonable for depths below 150-200 km, but is too high for shallower depths. Apparently, conductivity is not controlled solely by olivine at shallow depths.

Statistical analysis of the determinations of the Sun's Galactocentric distance

NASA Astrophysics Data System (ADS)

Malkin, Zinovy

2013-02-01

Based on several tens of R0 measurements made during the past two decades, several studies have been performed to derive the best estimate of R0. Some used just simple averaging to derive a result, whereas others provided comprehensive analyses of possible errors in published results. In either case, detailed statistical analyses of data used were not performed. However, a computation of the best estimates of the Galactic rotation constants is not only an astronomical but also a metrological task. Here we perform an analysis of 53 R0 measurements (published in the past 20 years) to assess the consistency of the data. Our analysis shows that they are internally consistent. It is also shown that any trend in the R0 estimates from the last 20 years is statistically negligible, which renders the presence of a bandwagon effect doubtful. On the other hand, the formal errors in the published R0 estimates improve significantly with time.

Service quality, satisfaction, and behavioral intention in home delivered meals program

PubMed Central

Joung, Hyun-Woo; Yuan, Jingxue Jessica; Huffman, Lynn

2011-01-01

This study was conducted to evaluate recipients' perception of service quality, satisfaction, and behavioral intention in home delivered meals program in the US. Out of 398 questionnaires, 265 (66.6%) were collected, and 209 questionnaires (52.5%) were used for the statistical analysis. A Confirmatory Factor Analysis (CFA) with a maximum likelihood was first conducted to estimate the measurement model by verifying the underlying structure of constructs. The level of internal consistency in each construct was acceptable, with Cronbach's alpha estimates ranging from 0.7 to 0.94. All of the composite reliabilities of the constructs were over the cutoff value of 0.50, ensuring adequate internal consistency of multiple items for each construct. As a second step, a Meals-On-Wheels (MOW) recipient perception model was estimated. The model's fit as indicated by these indexes was satisfactory and path coefficients were analyzed. Two paths between (1) volunteer issues and behavioral intention and (2) responsiveness and behavioral intention were not significant. The path for predicting a positive relationship between food quality and satisfaction was supported. The results show that having high food quality may create recipient satisfaction. The findings suggest that food quality and responsiveness are significant predictors of positive satisfaction. Moreover, satisfied recipients have positive behavioral intention toward MOW programs. PMID:21556231

Service quality, satisfaction, and behavioral intention in home delivered meals program.

PubMed

Joung, Hyun-Woo; Kim, Hak-Seon; Yuan, Jingxue Jessica; Huffman, Lynn

2011-04-01

This study was conducted to evaluate recipients' perception of service quality, satisfaction, and behavioral intention in home delivered meals program in the US. Out of 398 questionnaires, 265 (66.6%) were collected, and 209 questionnaires (52.5%) were used for the statistical analysis. A Confirmatory Factor Analysis (CFA) with a maximum likelihood was first conducted to estimate the measurement model by verifying the underlying structure of constructs. The level of internal consistency in each construct was acceptable, with Cronbach's alpha estimates ranging from 0.7 to 0.94. All of the composite reliabilities of the constructs were over the cutoff value of 0.50, ensuring adequate internal consistency of multiple items for each construct. As a second step, a Meals-On-Wheels (MOW) recipient perception model was estimated. The model's fit as indicated by these indexes was satisfactory and path coefficients were analyzed. Two paths between (1) volunteer issues and behavioral intention and (2) responsiveness and behavioral intention were not significant. The path for predicting a positive relationship between food quality and satisfaction was supported. The results show that having high food quality may create recipient satisfaction. The findings suggest that food quality and responsiveness are significant predictors of positive satisfaction. Moreover, satisfied recipients have positive behavioral intention toward MOW programs.

The Reliability of the OWLS Written Expression Scale with ESL Kindergarten Students

ERIC Educational Resources Information Center

Harrison, Gina L.; Ogle, Keira C.; Keilty, Megan

2011-01-01

A reliability analysis was conducted on the Written Expression Scale from the Oral and Written Language Scales, (OWLS, Carrow-Woolfolk, 1996), with 68 ESL and 56 non-ESL kindergarten students. Interrater and internal consistency estimates for the Written Expression Scale were examined separately for each language group. Despite lower oral English…

Changes in School Climate in a Long-Term Perspective

ERIC Educational Resources Information Center

Kallestad, Jan Helge

2010-01-01

In a previous report five school climate instruments were explored (1983 and 1985), and four scales were regarded as meaningful climate measures according to suggested criteria. These scales were re-inspected in the present study (1997 and 1998) by analyses of internal consistency, estimates of reliability (unit and aggregated reliability), and…

Measures of Instruction for Creative Engagement: Making Metacognition, Modeling and Creative Thinking Visible

ERIC Educational Resources Information Center

Pitts, Christine; Anderson, Ross; Haney, Michele

2018-01-01

The purpose of the current study was to estimate reliability, internal consistency and construct validity of the Measure of Instruction for Creative Engagement (MICE) instrument. The MICE uses an iterative process of evidence collection and scoring through teacher observations to determine instructional domain ratings and overall scores. The…

Which preparatory curriculum for the International Baccalaureate Diploma Programme is best? The challenge for international schools with regard to mathematics and science

NASA Astrophysics Data System (ADS)

Corlu, M. Sencer

2014-12-01

There are two mainstream curricula for international school students at the junior high level: the International Baccalaureate (IB) Middle Years Programme (MYP) and the Cambridge International General Certificate of Secondary Education (IGCSE). The former was developed in the mid-1990s and is currently being relaunched in a 21st-century approach. The latter programme of study was developed by University of Cambridge International Examinations in 1985 and has become popular in recent years among British domestic and international schools worldwide due to the clarity of its learning content. The prevailing uncertainty about which curriculum is best to prepare students for the IB Diploma Programme represents a challenge for international schools. The purpose of the current study is to develop a methodology through causal models which can explain the relationship between student performance in the IGCSE and the Diploma Programme with regard to mathematics and science. The data evaluated here consisted of external examination scores of students who attended a private international high school between the years 2005 and 2012. Two structural equation models were developed. The first model employed a maximum likelihood estimation, while the second model used a Bayesian estimation with a Markov Chain Monte Carlo method. Both models fit the data well. The evidence suggests that the IGCSE provides a good foundational preparation for the Diploma Programme in mathematics and science.

Internal tides and vertical mixing over the Kerguelen Plateau

NASA Astrophysics Data System (ADS)

Park, Young-Hyang; Fuda, Jean-Luc; Durand, Isabelle; Naveira Garabato, Alberto C.

2008-03-01

Within the context of the natural iron-fertilization study KEOPS, time series measurements of CTD and LADCP profiles at a site (50.6°S, 72°E; 528 m) coinciding with an annual phytoplankton bloom over the Kerguelen Plateau were made during the January-February 2005 KEOPS cruise. An important activity of highly nonlinear semidiurnal internal tides having peak-to-peak isopycnal displacements of up to 80 m is identified. These internal tides appear to be a principal agent for promoting elevated vertical mixing indispensable for upward transfer of iron within the seasonal thermocline. We estimate local vertical eddy diffusivities of the order of 4×10 -4 m 2 s -1 using a Thorpe scale analysis. Although this estimate is higher by an order of magnitude than the canonical value O (0.1×10 -4 m 2 s -1) in the open ocean away from boundaries, it is consistent with nonlinear internal wave/wave interaction theories, as verified by independent diffusivity estimates using the vertical wavenumber spectral methods for shear and strain. It is also suggested that the general ocean circulation may play an important role in preconditioning the bloom in that the relatively sluggish circulation over the shallow plateau (compared to the much more dynamic neighbouring deep ocean) may foster the bloom's observed annual recurrence over the plateau.

Sieve estimation of Cox models with latent structures.

PubMed

Cao, Yongxiu; Huang, Jian; Liu, Yanyan; Zhao, Xingqiu

2016-12-01

This article considers sieve estimation in the Cox model with an unknown regression structure based on right-censored data. We propose a semiparametric pursuit method to simultaneously identify and estimate linear and nonparametric covariate effects based on B-spline expansions through a penalized group selection method with concave penalties. We show that the estimators of the linear effects and the nonparametric component are consistent. Furthermore, we establish the asymptotic normality of the estimator of the linear effects. To compute the proposed estimators, we develop a modified blockwise majorization descent algorithm that is efficient and easy to implement. Simulation studies demonstrate that the proposed method performs well in finite sample situations. We also use the primary biliary cirrhosis data to illustrate its application. © 2016, The International Biometric Society.

Multiple imputation for cure rate quantile regression with censored data.

PubMed

Wu, Yuanshan; Yin, Guosheng

2017-03-01

The main challenge in the context of cure rate analysis is that one never knows whether censored subjects are cured or uncured, or whether they are susceptible or insusceptible to the event of interest. Considering the susceptible indicator as missing data, we propose a multiple imputation approach to cure rate quantile regression for censored data with a survival fraction. We develop an iterative algorithm to estimate the conditionally uncured probability for each subject. By utilizing this estimated probability and Bernoulli sample imputation, we can classify each subject as cured or uncured, and then employ the locally weighted method to estimate the quantile regression coefficients with only the uncured subjects. Repeating the imputation procedure multiple times and taking an average over the resultant estimators, we obtain consistent estimators for the quantile regression coefficients. Our approach relaxes the usual global linearity assumption, so that we can apply quantile regression to any particular quantile of interest. We establish asymptotic properties for the proposed estimators, including both consistency and asymptotic normality. We conduct simulation studies to assess the finite-sample performance of the proposed multiple imputation method and apply it to a lung cancer study as an illustration. © 2016, The International Biometric Society.

Observing Tsunamis in the Ionosphere Using Ground Based GPS Measurements

NASA Technical Reports Server (NTRS)

Galvan, D. A.; Komjathy, A.; Song, Y. Tony; Stephens, P.; Hickey, M. P.; Foster, J.

2011-01-01

Ground-based Global Positioning System (GPS) measurements of ionospheric Total Electron Content (TEC) show variations consistent with atmospheric internal gravity waves caused by ocean tsunamis following recent seismic events, including the Tohoku tsunami of March 11, 2011. We observe fluctuations correlated in time, space, and wave properties with this tsunami in TEC estimates processed using JPL's Global Ionospheric Mapping Software. These TEC estimates were band-pass filtered to remove ionospheric TEC variations with periods outside the typical range of internal gravity waves caused by tsunamis. Observable variations in TEC appear correlated with the Tohoku tsunami near the epicenter, at Hawaii, and near the west coast of North America. Disturbance magnitudes are 1-10% of the background TEC value. Observations near the epicenter are compared to estimates of expected tsunami-driven TEC variations produced by Embry Riddle Aeronautical University's Spectral Full Wave Model, an atmosphere-ionosphere coupling model, and found to be in good agreement. The potential exists to apply these detection techniques to real-time GPS TEC data, providing estimates of tsunami speed and amplitude that may be useful for future early warning systems.

Confirmatory Factor Analysis of Persian Adaptation of Multidimensional Students' Life Satisfaction Scale (MSLSS)

ERIC Educational Resources Information Center

Hatami, Gissou; Motamed, Niloofar; Ashrafzadeh, Mahshid

2010-01-01

Validity and reliability of Persian adaptation of MSLSS in the 12-18 years, middle and high school students (430 students in grades 6-12 in Bushehr port, Iran) using confirmatory factor analysis by means of LISREL statistical package were checked. Internal consistency reliability estimates (Cronbach's coefficient [alpha]) were all above the…

A Validation of the Ski Hi Language Development Scale.

ERIC Educational Resources Information Center

Tonelson, Stephen W.

The purpose of the study was to assess the reliability and the validity of the Ski Hi Language Development Scale which was designed to determine the receptive and the expressive language levels of hearing impaired children from birth to age 5. The reliability of the instrument was estimated through: (1) internal consistency, (2) inter-rater…

The SASSI-3 Face Valid other Drugs Scale: A Psychometric Investigation (Substance Abuse Subtle Screening Inventory-3)

ERIC Educational Resources Information Center

Laux, John M.; Perera-Diltz, Dilani; Smirnoff, Jennifer B.; Salyers, Kathleen M.

2005-01-01

The authors investigated the psychometric capabilities of the Face Valid Other Drugs (FVOD) scale of the Substance Abuse Subtle Screening Inventory-3 (SASSI-3; G. A. Miller, 1999). Internal consistency reliability estimates and construct validity factor analysis for 230 college students provided initial support for the psychometric properties of…

SAS and SPSS macros to calculate standardized Cronbach's alpha using the upper bound of the phi coefficient for dichotomous items.

PubMed

Sun, Wei; Chou, Chih-Ping; Stacy, Alan W; Ma, Huiyan; Unger, Jennifer; Gallaher, Peggy

2007-02-01

Cronbach's a is widely used in social science research to estimate the internal consistency of reliability of a measurement scale. However, when items are not strictly parallel, the Cronbach's a coefficient provides a lower-bound estimate of true reliability, and this estimate may be further biased downward when items are dichotomous. The estimation of standardized Cronbach's a for a scale with dichotomous items can be improved by using the upper bound of coefficient phi. SAS and SPSS macros have been developed in this article to obtain standardized Cronbach's a via this method. The simulation analysis showed that Cronbach's a from upper-bound phi might be appropriate for estimating the real reliability when standardized Cronbach's a is problematic.

Cycles till failure of silver-zinc cells with completing failures modes: Preliminary data analysis

NASA Technical Reports Server (NTRS)

Sidik, S. M.; Leibecki, H. F.; Bozek, J. M.

1980-01-01

One hundred and twenty nine cells were run through charge-discharge cycles until failure. The experiment design was a variant of a central composite factorial in five factors. Preliminary data analysis consisted of response surface estimation of life. Batteries fail under two basic modes; a low voltage condition and an internal shorting condition. A competing failure modes analysis using maximum likelihood estimation for the extreme value life distribution was performed. Extensive diagnostics such as residual plotting and probability plotting were employed to verify data quality and choice of model.

Cycles till failure of silver-zinc cells with competing failure modes - Preliminary data analysis

NASA Technical Reports Server (NTRS)

Sidik, S. M.; Leibecki, H. F.; Bozek, J. M.

1980-01-01

The data analysis of cycles to failure of silver-zinc electrochemical cells with competing failure modes is presented. The test ran 129 cells through charge-discharge cycles until failure; preliminary data analysis consisted of response surface estimate of life. Batteries fail through low voltage condition and an internal shorting condition; a competing failure modes analysis was made using maximum likelihood estimation for the extreme value life distribution. Extensive residual plotting and probability plotting were used to verify data quality and selection of model.

Evaluation of General Classes of Reliability Estimators Often Used in Statistical Analyses of Quasi-Experimental Designs

NASA Astrophysics Data System (ADS)

Saini, K. K.; Sehgal, R. K.; Sethi, B. L.

2008-10-01

In this paper major reliability estimators are analyzed and there comparatively result are discussed. There strengths and weaknesses are evaluated in this case study. Each of the reliability estimators has certain advantages and disadvantages. Inter-rater reliability is one of the best ways to estimate reliability when your measure is an observation. However, it requires multiple raters or observers. As an alternative, you could look at the correlation of ratings of the same single observer repeated on two different occasions. Each of the reliability estimators will give a different value for reliability. In general, the test-retest and inter-rater reliability estimates will be lower in value than the parallel forms and internal consistency ones because they involve measuring at different times or with different raters. Since reliability estimates are often used in statistical analyses of quasi-experimental designs.

A dynamic Thurstonian item response theory of motive expression in the picture story exercise: solving the internal consistency paradox of the PSE.

PubMed

Lang, Jonas W B

2014-07-01

The measurement of implicit or unconscious motives using the picture story exercise (PSE) has long been a target of debate in the psychological literature. Most debates have centered on the apparent paradox that PSE measures of implicit motives typically show low internal consistency reliability on common indices like Cronbach's alpha but nevertheless predict behavioral outcomes. I describe a dynamic Thurstonian item response theory (IRT) model that builds on dynamic system theories of motivation, theorizing on the PSE response process, and recent advancements in Thurstonian IRT modeling of choice data. To assess the models' capability to explain the internal consistency paradox, I first fitted the model to archival data (Gurin, Veroff, & Feld, 1957) and then simulated data based on bias-corrected model estimates from the real data. Simulation results revealed that the average squared correlation reliability for the motives in the Thurstonian IRT model was .74 and that Cronbach's alpha values were similar to the real data (<.35). These findings suggest that PSE motive measures have long been reliable and increase the scientific value of extant evidence from motivational research using PSE motive measures. (c) 2014 APA, all rights reserved.

The importance of children's illness beliefs: the Children's Illness Perception Questionnaire (CIPQ) as a reliable assessment tool for eczema and asthma.

PubMed

Walker, C; Papadopoulos, L; Lipton, M; Hussein, M

2006-02-01

A lack of information about disease in children can lead to erroneous views such as children believing that hospital admittance or the presence of a disease is a punishment for a perceived wrong. There has thus far been no standard tool available to measure children's illness conceptualizations from a Leventhalian framework. Three groups of children with eczema, asthma and eczema and asthma between the ages of 7 and 12 years of age were recruited. Children were given the Children's Illness Perception Questionnaire (CIPQ), a 26-item instrument adapted from the Illness Perception Questionnaire for adults. A Kuder - Richardson 20 test of reliability for dichotomous data was performed allowing an estimate of the internal consistency of the measurement scales. It can be seen that, for all three illness groups, internal consistency is acceptable for the timeline and consequences scale. The cure/control scale, however, was not internally consistent for any illness group. As health professionals, we need to develop the means to further understand how paediatric illness beliefs relate to specific disease types, age and psychosocial factors and the utility of this instrument is discussed within this context.

A representative survey of the dynamics and energetics of FR II radio galaxies

NASA Astrophysics Data System (ADS)

Ineson, J.; Croston, J. H.; Hardcastle, M. J.; Mingo, B.

2017-05-01

We report the first large, systematic study of the dynamics and energetics of a representative sample of Fanaroff-Riley type II (FR II) radio galaxies with well-characterized group/cluster environments. We used X-ray inverse-Compton and radio synchrotron measurements to determine the internal radio-lobe conditions, and these were compared with external pressures acting on the lobes, determined from measurements of the thermal X-ray emission of the group/cluster. Consistent with previous work, we found that FR II radio lobes are typically electron dominated by a small factor relative to equipartition, and are overpressured relative to the external medium in their outer parts. These results suggest that there is typically no energetically significant proton population in the lobes of FR II radio galaxies (unlike for FR Is), and so for this population, inverse-Compton modelling provides an accurate way of measuring total energy content and estimating jet power. We estimated the distribution of Mach numbers for the population of expanding radio lobes, finding that at least half of the radio galaxies are currently driving strong shocks into their group/cluster environments. Finally, we determined a jet power-radio luminosity relation for FR II radio galaxies based on our estimates of lobe internal energy and Mach number. The slope and normalization of this relation are consistent with theoretical expectations, given the departure from equipartition and environmental distribution for our sample.

State-of-charge estimation in lithium-ion batteries: A particle filter approach

NASA Astrophysics Data System (ADS)

Tulsyan, Aditya; Tsai, Yiting; Gopaluni, R. Bhushan; Braatz, Richard D.

2016-11-01

The dynamics of lithium-ion batteries are complex and are often approximated by models consisting of partial differential equations (PDEs) relating the internal ionic concentrations and potentials. The Pseudo two-dimensional model (P2D) is one model that performs sufficiently accurately under various operating conditions and battery chemistries. Despite its widespread use for prediction, this model is too complex for standard estimation and control applications. This article presents an original algorithm for state-of-charge estimation using the P2D model. Partial differential equations are discretized using implicit stable algorithms and reformulated into a nonlinear state-space model. This discrete, high-dimensional model (consisting of tens to hundreds of states) contains implicit, nonlinear algebraic equations. The uncertainty in the model is characterized by additive Gaussian noise. By exploiting the special structure of the pseudo two-dimensional model, a novel particle filter algorithm that sweeps in time and spatial coordinates independently is developed. This algorithm circumvents the degeneracy problems associated with high-dimensional state estimation and avoids the repetitive solution of implicit equations by defining a 'tether' particle. The approach is illustrated through extensive simulations.

International standards for monoclonal antibodies to support pre- and post-marketing product consistency: Evaluation of a candidate international standard for the bioactivities of rituximab.

PubMed

Prior, Sandra; Hufton, Simon E; Fox, Bernard; Dougall, Thomas; Rigsby, Peter; Bristow, Adrian

2018-01-01

The intrinsic complexity and heterogeneity of therapeutic monoclonal antibodies is built into the biosimilarity paradigm where critical quality attributes are controlled in exhaustive comparability studies with the reference medicinal product. The long-term success of biosimilars will depend on reassuring healthcare professionals and patients of consistent product quality, safety and efficacy. With this aim, the World Health Organization has endorsed the need for public bioactivity standards for therapeutic monoclonal antibodies in support of current controls. We have developed a candidate international potency standard for rituximab that was evaluated in a multi-center collaborative study using participants' own qualified Fc-effector function and cell-based binding bioassays. Dose-response curve model parameters were shown to reflect similar behavior amongst rituximab preparations, albeit with some differences in potency. In the absence of a common reference standard, potency estimates were in poor agreement amongst laboratories, but the use of the candidate preparation significantly reduced this variability. Our results suggest that the candidate rituximab standard can support bioassay performance and improve data harmonization, which when implemented will promote consistency of rituximab products over their life-cycles. This data provides the first scientific evidence that a classical standardization exercise allowing traceability of bioassay data to an international standard is also applicable to rituximab. However, we submit that this new type of international standard needs to be used appropriately and its role not to be mistaken with that of the reference medicinal product.

Development of a self-report questionnaire designed for population-based surveillance of gingivitis in adolescents: assessment of content validity and reliability.

PubMed

Quiroz, Viviana; Reinero, Daniela; Hernández, Patricia; Contreras, Johanna; Vernal, Rolando; Carvajal, Paola

2017-01-01

This study aimed to develop and assess the content validity and reliability of a cognitively adapted self-report questionnaire designed for surveillance of gingivitis in adolescents. Ten predetermined self-report questions evaluating early signs and symptoms of gingivitis were preliminary assessed by a panel of clinical experts. Eight questions were selected and cognitively tested in 20 adolescents aged 12 to 18 years from Santiago de Chile. The questionnaire was then conducted and answered by 178 Chilean adolescents. Internal consistency was measured using the Cronbach's alpha and temporal stability was calculated using the Kappa-index. A reliable final self-report questionnaire consisting of 5 questions was obtained, with a total Cronbach's alpha of 0.73 and a Kappa-index ranging from 0.41 to 0.77 between the different questions. The proposed questionnaire is reliable, with an acceptable internal consistency and a temporal stability from moderate to substantial, and it is promising for estimating the prevalence of gingivitis in adolescents.

Technical Characteristics of the Peabody Individual Achievement Test as a Function of Item Arrangement and Basal and Ceiling Rules.

ERIC Educational Resources Information Center

Browning, Robert; And Others

1979-01-01

Effects that item order and basal and ceiling rules have on test means, variances, and internal consistency estimates for the Peabody Individual Achievement Test mathematics and reading recognition subtests were examined. Items on the math and reading recognition subtests were significantly easier or harder than test placements indicated. (Author)

Test-Retest Analyses of the Test of English as a Foreign Language. TOEFL Research Reports Report 45.

ERIC Educational Resources Information Center

Henning, Grant

This study provides information about the total and component scores of the Test of English as a Foreign Language (TOEFL). First, the study provides comparative global and component estimates of test-retest, alternate-form, and internal-consistency reliability, controlling for sources of measurement error inherent in the examinees and the testing…

On the Use, the Misuse, and the Very Limited Usefulness of Cronbach's Alpha

ERIC Educational Resources Information Center

Sijtsma, Klaas

2009-01-01

This discussion paper argues that both the use of Cronbach's alpha as a reliability estimate and as a measure of internal consistency suffer from major problems. First, alpha always has a value, which cannot be equal to the test score's reliability given the inter-item covariance matrix and the usual assumptions about measurement error. Second, in…

Age and the elderly internal clock - Further evidence for a fundamentally slowed CNS

NASA Technical Reports Server (NTRS)

Cann, Michael T.; Vercruyssen, Max; Hancock, P. A.

1990-01-01

Age-related differences in accuracy of time estimation have been studied. It is found that compared to the younger subjects (mean age 25 years), the older adults (mean age 70 years) consistently overestimated the target 10-sec interval when they had to simultaneously perform an interpolating task (i.e., count backwards by subtractions of three).

Morphological analysis of pore size and connectivity in a thick mixed-culture biofilm.

PubMed

Rosenthal, Alex F; Griffin, James S; Wagner, Michael; Packman, Aaron I; Balogun, Oluwaseyi; Wells, George F

2018-05-19

Morphological parameters are commonly used to predict transport and metabolic kinetics in biofilms. Yet, quantification of biofilm morphology remains challenging due to imaging technology limitations and lack of robust analytical approaches. We present a novel set of imaging and image analysis techniques to estimate internal porosity, pore size distributions, and pore network connectivity to a depth of 1 mm at a resolution of 10 µm in a biofilm exhibiting both heterotrophic and nitrifying activity. Optical coherence tomography (OCT) scans revealed an extensive pore network with diameters as large as 110 µm directly connected to the biofilm surface and surrounding fluid. Thin section fluorescence in situ hybridization microscopy revealed ammonia oxidizing bacteria (AOB) distributed through the entire thickness of the biofilm. AOB were particularly concentrated in the biofilm around internal pores. Areal porosity values estimated from OCT scans were consistently lower than those estimated from multiphoton laser scanning microscopy, though the two imaging modalities showed a statistically significant correlation (r = 0.49, p<0.0001). Estimates of areal porosity were moderately sensitive to grey level threshold selection, though several automated thresholding algorithms yielded similar values to those obtained by manually thresholding performed by a panel of environmental engineering researchers (±25% relative error). These findings advance our ability to quantitatively describe the geometry of biofilm internal pore networks at length scales relevant to engineered biofilm reactors and suggest that internal pore structures provide crucial habitat for nitrifier growth. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Is Coefficient Alpha Robust to Non-Normal Data?

PubMed Central

Sheng, Yanyan; Sheng, Zhaohui

2011-01-01

Coefficient alpha has been a widely used measure by which internal consistency reliability is assessed. In addition to essential tau-equivalence and uncorrelated errors, normality has been noted as another important assumption for alpha. Earlier work on evaluating this assumption considered either exclusively non-normal error score distributions, or limited conditions. In view of this and the availability of advanced methods for generating univariate non-normal data, Monte Carlo simulations were conducted to show that non-normal distributions for true or error scores do create problems for using alpha to estimate the internal consistency reliability. The sample coefficient alpha is affected by leptokurtic true score distributions, or skewed and/or kurtotic error score distributions. Increased sample sizes, not test lengths, help improve the accuracy, bias, or precision of using it with non-normal data. PMID:22363306

Annual estimates of recharge, quick-flow runoff, and ET for the contiguous U.S. using empirical regression equations

USGS Publications Warehouse

Reitz, Meredith; Sanford, Ward E.; Senay, Gabriel; Cazenas, J.

2017-01-01

This study presents new data-driven, annual estimates of the division of precipitation into the recharge, quick-flow runoff, and evapotranspiration (ET) water budget components for 2000-2013 for the contiguous United States (CONUS). The algorithms used to produce these maps ensure water budget consistency over this broad spatial scale, with contributions from precipitation influx attributed to each component at 800 m resolution. The quick-flow runoff estimates for the contribution to the rapidly varying portion of the hydrograph are produced using data from 1,434 gaged watersheds, and depend on precipitation, soil saturated hydraulic conductivity, and surficial geology type. Evapotranspiration estimates are produced from a regression using water balance data from 679 gaged watersheds and depend on land cover, temperature, and precipitation. The quick-flow and ET estimates are combined to calculate recharge as the remainder of precipitation. The ET and recharge estimates are checked against independent field data, and the results show good agreement. Comparisons of recharge estimates with groundwater extraction data show that in 15% of the country, groundwater is being extracted at rates higher than the local recharge. These maps of the internally consistent water budget components of recharge, quick-flow runoff, and ET, being derived from and tested against data, are expected to provide reliable first-order estimates of these quantities across the CONUS, even where field measurements are sparse.

Current risk estimates based on the A-bomb survivors data - a discussion in terms of the ICRP recommendations on the neutron weighting factor.

PubMed

Rühm, W; Walsh, L

2007-01-01

Currently, most analyses of the A-bomb survivors' solid tumour and leukaemia data are based on a constant neutron relative biological effectiveness (RBE) value of 10 that is applied to all survivors, independent of their distance to the hypocentre at the time of bombing. The results of these analyses are then used as a major basis for current risk estimates suggested by the International Commission on Radiological Protection (ICRP) for use in international safety guidelines. It is shown here that (i) a constant value of 10 is not consistent with weighting factors recommended by the ICRP for neutrons and (ii) it does not account for the hardening of the neutron spectra in Hiroshima and Nagasaki, which takes place with increasing distance from the hypocentres. The purpose of this paper is to present new RBE values for the neutrons, calculated as a function of distance from the hypocentres for both cities that are consistent with the ICRP60 neutron weighting factor. If based on neutron spectra from the DS86 dosimetry system, these calculations suggest values of about 31 at 1000 m and 23 at 2000 m ground range in Hiroshima, while the corresponding values for Nagasaki are 24 and 22. If the neutron weighting factor that is consistent with ICRP92 is used, the corresponding values are about 23 and 21 for Hiroshima and 21 and 20 for Nagasaki, respectively. It is concluded that the current risk estimates will be subject to some changes in view of the changed RBE values. This conclusion does not change significantly if the new doses from the Dosimetry System DS02 are used.

Toward a consistent modeling framework to assess multi-sectoral climate impacts.

PubMed

Monier, Erwan; Paltsev, Sergey; Sokolov, Andrei; Chen, Y-H Henry; Gao, Xiang; Ejaz, Qudsia; Couzo, Evan; Schlosser, C Adam; Dutkiewicz, Stephanie; Fant, Charles; Scott, Jeffery; Kicklighter, David; Morris, Jennifer; Jacoby, Henry; Prinn, Ronald; Haigh, Martin

2018-02-13

Efforts to estimate the physical and economic impacts of future climate change face substantial challenges. To enrich the currently popular approaches to impact analysis-which involve evaluation of a damage function or multi-model comparisons based on a limited number of standardized scenarios-we propose integrating a geospatially resolved physical representation of impacts into a coupled human-Earth system modeling framework. Large internationally coordinated exercises cannot easily respond to new policy targets and the implementation of standard scenarios across models, institutions and research communities can yield inconsistent estimates. Here, we argue for a shift toward the use of a self-consistent integrated modeling framework to assess climate impacts, and discuss ways the integrated assessment modeling community can move in this direction. We then demonstrate the capabilities of such a modeling framework by conducting a multi-sectoral assessment of climate impacts under a range of consistent and integrated economic and climate scenarios that are responsive to new policies and business expectations.

Nonparametric Discrete Survival Function Estimation with Uncertain Endpoints Using an Internal Validation Subsample

PubMed Central

Zee, Jarcy; Xie, Sharon X.

2015-01-01

Summary When a true survival endpoint cannot be assessed for some subjects, an alternative endpoint that measures the true endpoint with error may be collected, which often occurs when obtaining the true endpoint is too invasive or costly. We develop an estimated likelihood function for the situation where we have both uncertain endpoints for all participants and true endpoints for only a subset of participants. We propose a nonparametric maximum estimated likelihood estimator of the discrete survival function of time to the true endpoint. We show that the proposed estimator is consistent and asymptotically normal. We demonstrate through extensive simulations that the proposed estimator has little bias compared to the naïve Kaplan-Meier survival function estimator, which uses only uncertain endpoints, and more efficient with moderate missingness compared to the complete-case Kaplan-Meier survival function estimator, which uses only available true endpoints. Finally, we apply the proposed method to a dataset for estimating the risk of developing Alzheimer's disease from the Alzheimer's Disease Neuroimaging Initiative. PMID:25916510

Consistency of Use and Effectiveness of Household Water Treatment Practices among Urban and Rural Populations Claiming to Treat Their Drinking Water at Home: A Case Study in Zambia

PubMed Central

Rosa, Ghislaine; Kelly, Paul; Clasen, Thomas

2016-01-01

Household water treatment (HWT) can improve drinking water quality and prevent disease, if used correctly and consistently. While international monitoring suggests that 1.8 billion people practice HWT, these estimates are based on household surveys that may overstate the level of consistent use and do not address microbiological effectiveness. We sought to examine how HWT is practiced among households identified as HWT users according to international monitoring standards. Case studies were conducted in urban and rural Zambia. After a baseline survey (urban: 203 households, rural: 276 households) to identify HWT users, 95 urban and 82 rural households were followed up for 6 weeks. Consistency of HWT reporting was low; only 72.6% of urban and 50.0% of rural households reported to be HWT users in the subsequent visit. Similarly, availability of treated water was low, only 23.3% and 4.2% of urban and rural households, respectively, had treated water on all visits. Drinking water was significantly worse than source water in both settings. Only 19.6% of urban and 2.4% of rural households had drinking water free of thermotolerant coliforms on all visits. Our findings raise questions about the value of the data gathered through the international monitoring of HWT practices as predictors of water quality in the home. PMID:26572868

The Dutch motor skills assessment as tool for talent development in table tennis: a reproducibility and validity study.

PubMed

Faber, Irene R; Nijhuis-Van Der Sanden, Maria W G; Elferink-Gemser, Marije T; Oosterveld, Frits G J

2015-01-01

A motor skills assessment could be helpful in talent development by estimating essential perceptuo-motor skills of young players, which are considered requisite to develop excellent technical and tactical qualities. The Netherlands Table Tennis Association uses a motor skills assessment in their talent development programme consisting of eight items measuring perceptuo-motor skills specific to table tennis under varying conditions. This study aimed to investigate this assessment regarding its reproducibility, internal consistency, underlying dimensions and concurrent validity in 113 young table tennis players (6-10 years). Intraclass correlation coefficients of six test items met the criteria of 0.7 with coefficients of variation between 3% and 8%. Cronbach's alpha valued 0.853 for internal consistency. The principal components analysis distinguished two conceptually meaningful factors: "ball control" and "gross motor function." Concurrent validity analyses demonstrated moderate associations between the motor skills assessment's results and national ranking; boys r = -0.53 (P < 0.001) and girls r = -0.45 (P = 0.015). In conclusion, this evaluation demonstrated six test items with acceptable reproducibility, good internal consistency and good prospects for validity. Two test items need revision to upgrade reproducibility. Since the motor skills assessment seems to be a reproducible, objective part of a talent development programme, more longitudinal studies are required to investigate its predictive validity.

Development and application of a rat PBPK model to elucidate kidney and liver effects induced by ETBE and tert-butanol.

PubMed

Salazar, Keith D; Brinkerhoff, Christopher J; Lee, Janice S; Chiu, Weihsueh A

2015-11-01

Subchronic and chronic studies in rats of the gasoline oxygenates ethyl tert-butyl ether (ETBE) and tert-butanol (TBA) report similar noncancer kidney and liver effects but differing results with respect to kidney and liver tumors. Because TBA is a major metabolite of ETBE, it is possible that TBA is the active toxic moiety in all these studies, with reported differences due simply to differences in the internal dose. To test this hypothesis, a physiologically-based pharmacokinetic (PBPK) model was developed for ETBE and TBA to calculate internal dosimetrics of TBA following either TBA or ETBE exposure. This model, based on earlier PBPK models of methyl tert-butyl ether (MTBE), was used to evaluate whether kidney and liver effects are consistent across routes of exposure, as well as between ETBE and TBA studies, on the basis of estimated internal dose. The results demonstrate that noncancer kidney effects, including kidney weight changes, urothelial hyperplasia, and chronic progressive nephropathy (CPN), yielded consistent dose-response relationships across routes of exposure and across ETBE and TBA studies using TBA blood concentration as the dose metric. Relative liver weights were also consistent across studies on the basis of TBA metabolism, which is proportional to TBA liver concentrations. However, kidney and liver tumors were not consistent using any dose metric. These results support the hypothesis that TBA mediates the noncancer kidney and liver effects following ETBE administration; however, additional factors besides internal dose are necessary to explain the induction of liver and kidney tumors. Published by Elsevier Inc.

A test and re-estimation of Taylor's empirical capacity-reserve relationship

USGS Publications Warehouse

Long, K.R.

2009-01-01

In 1977, Taylor proposed a constant elasticity model relating capacity choice in mines to reserves. A test of this model using a very large (n = 1,195) dataset confirms its validity but obtains significantly different estimated values for the model coefficients. Capacity is somewhat inelastic with respect to reserves, with an elasticity of 0.65 estimated for open-pit plus block-cave underground mines and 0.56 for all other underground mines. These new estimates should be useful for capacity determinations as scoping studies and as a starting point for feasibility studies. The results are robust over a wide range of deposit types, deposit sizes, and time, consistent with physical constraints on mine capacity that are largely independent of technology. ?? 2009 International Association for Mathematical Geology.

Quantitative comparisons of cancer induction in humans by internally deposited radionuclides and external radiation.

PubMed

Harrison, J D; Muirhead, C R

2003-01-01

To compare quantitative estimates of lifetime cancer risk in humans for exposures to internally deposited radionuclides and external radiation. To assess the possibility that risks from radionuclide exposures may be underestimated. Risk estimates following internal exposures can be made for a small number of alpha-particle-emitting nuclides. (1) Lung cancer in underground miners exposed by inhalation to radon-222 gas and its short-lived progeny. Studies of residential (222)Rn exposure are generally consistent with predictions from the miner studies. (2) Liver cancer and leukaemia in patients given intravascular injections of Thorotrast, a thorium-232 oxide preparation that concentrates in liver, spleen and bone marrow. (3) Bone cancer in patients given injections of radium-224, and in workers exposed occupationally to (226)Ra and (228)Ra, mainly by ingestion. (4) Lung cancer in Mayak workers exposed to plutonium-239, mainly by inhalation. Liver and bone cancers were also seen, but the dosimetry is not yet sufficiently good enough to provide quantitative estimates of risks. Comparisons can be made between risk estimates for radiation-induced cancer derived for radionuclide exposure and those derived for the A-bomb survivors, exposed mainly to low-LET (linear energy transfer) external radiation. Data from animal studies, using dogs and rodents, allow comparisons of cancer induction by a range of alpha- and beta-/gamma-emitting radionuclides. They provide information on relative biological effectiveness (RBE), dose-response relationships, dose-rate effects and the location of target cells for different malignancies. For lung and liver cancer, the estimated values of risk per Sv for internal exposure, assuming an RBE for alpha-particles of 20, are reasonably consistent with estimates for external exposure to low-LET radiation. This also applies to bone cancer when risk is calculated on the basis of average bone dose, but consideration of dose to target cells on bone surfaces suggests a low RBE for alpha-particles. Similarly, for leukaemia, the comparison of risks from alpha-irradiation ((232)Th and progeny) and external radiation suggest a low alpha RBE; this conclusion is supported by animal data. Risk estimates for internal exposure are dependent on the assumptions made in calculating dose. Account is taken of the distribution of radionuclides within tissues and the distribution of target cells for cancer induction. For the lungs and liver, the available human and animal data provide support for current assumptions. However, for bone cancer and leukaemia, it may be that changes are required. Bone cancer risk may be best assessed by calculating dose to a 50 micro m layer of marrow adjacent to endosteal (inner) bone surfaces rather than to a single 10 micro m cell layer as currently assumed. Target cells for leukaemia may be concentrated towards the centre of marrow cavities so that the risk of leukaemia from bone-seeking radionuclides, particularly alpha emitters, may be overestimated by the current assumption of uniform distribution of target cells throughout red bone marrow. The lifetime risk estimates considered here for exposure to internally deposited radionuclides and to external radiation are subject to uncertainties, arising from the dosimetric assumptions made, from the quality of cancer incidence and mortality data and from aspects of risk modelling; including variations in baseline rates between populations for some cancer types. Bearing in mind such uncertainties, comparisons of risk estimates for internal emitters and external radiation show good agreement for lung and liver cancers. For leukaemia, the available data suggest that the assumption of an alpha-particle RBE of 20 can result in overestimates of risk. For bone cancer, it also appears that current assumptions will overestimate risks from alpha-particle-emitting nuclides, particularly at low doses.

Internal stresses in pre-stressed micron-scale aluminum core-shell particles and their improved reactivity

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

Levitas, Valery I., E-mail: vlevitas@iastate.edu; McCollum, Jena; Pantoya, Michelle L.

2015-09-07

Dilatation of aluminum (Al) core for micron-scale particles covered by alumina (Al{sub 2}O{sub 3}) shell was measured utilizing x-ray diffraction with synchrotron radiation for untreated particles and particles after annealing at 573 K and fast quenching at 0.46 K/s. Such a treatment led to the increase in flame rate for Al + CuO composite by 32% and is consistent with theoretical predictions based on the melt-dispersion mechanism of reaction for Al particles. Experimental results confirmed theoretical estimates and proved that the improvement of Al reactivity is due to internal stresses. This opens new ways of controlling particle reactivity through creating and monitoringmore » internal stresses.« less

A Psychometric Analysis of Quality of Life Tools in Lung Cancer Patients Who Smoke

PubMed Central

Browning, Kristine K.; Ferketich, Amy K.; Otterson, Gregory A.; Reynolds, Nancy R.; Wewers, Mary Ellen

2009-01-01

Lung cancer is the leading cause of cancer death for both men and women in the United States. Patient quality of life (QOL) prior to cancer treatment is known to be a strong predictor of survival and toleration of treatment toxicities. A lung cancer patient’s self-assessment of QOL is highly valued among clinicians as it guides treatment-related decisions and impacts clinical outcomes. Smokers are known to report a lower QOL. Limited research has been conducted on QOL outcomes in lung cancer patients who continue to smoke. To assess QOL, a reliable and valid QOL measure specific to lung cancer is required. The Functional Assessment of Cancer Therapy-Lung Cancer (FACT-L) and Lung Cancer Symptom Scale (LCSS) are instruments that specifically examine QOL among lung cancer patients. The LCSS is a focused QOL instrument that includes physical and functional domains of QOL and disease symptomatology. The FACT-L is a broader QOL instrument that includes physical, functional, social and emotional domains and disease symptomatology. Both are psychometrically valid and are widely used in the literature, but have not been exclusively evaluated in smokers. Furthermore, there is no ‘gold standard’ instrument since there has never been a correlation study to compare estimates of reliability and validity between these instruments. The purpose of this study is to report the internal consistency and convergence validity of the FACT-L and the LCSS among newly diagnosed lung cancer patients who smoke. This data were collected and analyzed from a larger study examining smoking behavior among newly diagnosed lung cancer patients (n=51). Descriptive statistics were calculated on the FACT-L and LCSS scores, internal consistency was assessed by estimating Cronbach’s alpha coefficients, and Pearson correlation coefficients were estimated between the two scales. Internal consistency coefficients demonstrated good reliability for both scales, and the two instruments demonstrated a strong correlation, suggesting good convergence validity. Either of these instruments are appropriate measures for QOL in lung cancer patients who smoke. Given the conceptual difference between the two instruments, it is important to carefully consider the research aims when selecting the appropriate QOL measurement instrument. PMID:19181418

A New Potential Energy Surface for N+O2: Is There an NOO Minimum?

NASA Technical Reports Server (NTRS)

Walch, Stephen P.

1995-01-01

We report a new calculation of the N+02 potential energy surface using complete active space self-consistent field internally contracted configuration interaction with the Dunning correlation consistent basis sets. The peroxy isomer of N02 is found to be a very shallow minimum separated from NO+O by a barrier of only 0.3 kcal/mol (excluding zero-point effects). The entrance channel barrier height is estimated to be 8.6 kcal/mol for ICCI+Q calculations correlating all but the Ols and N1s electrons with a cc-p VQZ basis set.

Cross-cultural challenges for assessing medical professionalism among clerkship physicians in a Middle Eastern country (Bahrain): feasibility and psychometric properties of multisource feedback.

PubMed

Al Ansari, Ahmed; Al Khalifa, Khalid; Al Azzawi, Mohamed; Al Amer, Rashed; Al Sharqi, Dana; Al-Mansoor, Anwar; Munshi, Fadi M

2015-01-01

We aimed to design, implement, and evaluate the feasibility and reliability of a multisource feedback (MSF) system to assess interns in their clerkship year in the Middle Eastern culture, the Kingdom of Bahrain. The study was undertaken in the Bahrain Defense Force Hospital, a military teaching hospital in the Kingdom of Bahrain. A total of 21 interns (who represent the total population of the interns for the given year) were assessed in this study. All of the interns were rotating through our hospital during their year-long clerkship rotation. The study sample consisted of nine males and 12 females. Each participating intern was evaluated by three groups of raters, eight medical intern colleagues, eight senior medical colleagues, and eight coworkers from different departments. A total of 21 interns (nine males and 12 females) were assessed in this study. The total mean response rates were 62.3%. A factor analysis was conducted that found that the data on the questionnaire grouped into three factors that counted for 76.4% of the total variance. These three factors were labeled as professionalism, collaboration, and communication. Reliability analysis indicated that the full instrument scale had high internal consistency (Cronbach's α 0.98). The generalizability coefficients for the surveys were estimated to be 0.78. Based on our results and analysis, we conclude that the MSF tool we used on the interns rotating in their clerkship year within our Middle Eastern culture provides an effective method of evaluation because it offers a reliable, valid, and feasible process.

Processing of angular motion and gravity information through an internal model.

PubMed

Laurens, Jean; Straumann, Dominik; Hess, Bernhard J M

2010-09-01

The vestibular organs in the base of the skull provide important information about head orientation and motion in space. Previous studies have suggested that both angular velocity information from the semicircular canals and information about head orientation and translation from the otolith organs are centrally processed in an internal model of head motion, using the principles of optimal estimation. This concept has been successfully applied to model behavioral responses to classical vestibular motion paradigms. This study measured the dynamic of the vestibuloocular reflex during postrotatory tilt, tilt during the optokinetic afternystagmus, and off-vertical axis rotation. The influence of otolith signal on the VOR was systematically varied by using a series of tilt angles. We found that the time constants of responses varied almost identically as a function of gravity in these paradigms. We show that Bayesian modeling could predict the experimental results in an accurate and consistent manner. In contrast to other approaches, the Bayesian model also provides a plausible explanation of why these vestibulooculo motor responses occur as a consequence of an internal process of optimal motion estimation.

International standards for monoclonal antibodies to support pre- and post-marketing product consistency: Evaluation of a candidate international standard for the bioactivities of rituximab

PubMed Central

Prior, Sandra; Hufton, Simon E.; Dougall, Thomas; Rigsby, Peter; Bristow, Adrian

2018-01-01

ABSTRACT The intrinsic complexity and heterogeneity of therapeutic monoclonal antibodies is built into the biosimilarity paradigm where critical quality attributes are controlled in exhaustive comparability studies with the reference medicinal product. The long-term success of biosimilars will depend on reassuring healthcare professionals and patients of consistent product quality, safety and efficacy. With this aim, the World Health Organization has endorsed the need for public bioactivity standards for therapeutic monoclonal antibodies in support of current controls. We have developed a candidate international potency standard for rituximab that was evaluated in a multi-center collaborative study using participants' own qualified Fc-effector function and cell-based binding bioassays. Dose-response curve model parameters were shown to reflect similar behavior amongst rituximab preparations, albeit with some differences in potency. In the absence of a common reference standard, potency estimates were in poor agreement amongst laboratories, but the use of the candidate preparation significantly reduced this variability. Our results suggest that the candidate rituximab standard can support bioassay performance and improve data harmonization, which when implemented will promote consistency of rituximab products over their life-cycles. This data provides the first scientific evidence that a classical standardization exercise allowing traceability of bioassay data to an international standard is also applicable to rituximab. However, we submit that this new type of international standard needs to be used appropriately and its role not to be mistaken with that of the reference medicinal product. PMID:28985159

Internal consistency of the Spanish health literacy test (TOFHLA-SPR) for Puerto Rico.

PubMed

Rivero-Méndez, Marta; Suárez, Erick; Solís-Báez, Solymar S; Hernández, Gloryvee; Cordero, Wanda; Vázquez, Irma; Medina, Zullettevy; Padilla, Raisa; Flores, Aida; Bonilla, José Luis; Holzemer, William L

2010-03-01

Low functional health literacy has been related to poor viral control, and lower levels of ART adherence in people living with HIV/AIDS. Research in functional health literacy among people living with HIV/AIDS in Puerto Rico (PR) is an unexplored area. The purpose of this paper is to describe how the full-length Spanish Version of the Test of Functional Health Literacy in Adults (TOFHLA-S) scale was adapted to PR. Thirty participants (women = 16, men = 14) completed a basic demographic questionnaire, the TOFHLA-S and participated in an interview. Analyses were performed to examine the information provided by participants and the internal consistency of the TOFHLA-S. The mean age was 47.7 years (range 34-77). Thirty-seven percent had less than 12 years of formal schooling and 43% reported having education above high school. Changes suggested by participants included: increasing font size from 14 to 16 points for better readability and changes/simplification of several words in order to make them colloquial and comprehensible for the PR context. The reliability coefficient obtained for this scale was strong (estimated alpha = 0.95) however, differences were observed by subtype: numeracy (estimated alpha(num) = .819 vs. comprehension (estimated alpha =. 953). Based on this process, we have adapted the original version of the TOFHLA-S and the new version of the full-length TOFHLA-S, PR is now valid for further research and testing levels of functional health literacy in a larger sample in PR.

Internal Consistency of the Spanish Health Literacy Test (TOFHLA-SPR) for Puerto Rico

PubMed Central

Rivero-Méndez, Marta; Suárez, Erick; Solís-Báez, Solymar S.; Hernández, Gloryvee; Cordero, Wanda; Vázquez, Irma; Medina, Zullettevy; Padilla, Raisa; Flores, Aida; Bonilla, José Luis; Holzemer, William L.

2010-01-01

Background Low functional health literacy has been related to poor viral control, and lower levels of ART adherence in people living with HIV/AIDS. Research in functional health literacy among people living with HIV/AIDS in Puerto Rico (PR) is an unexplored area. The purpose of this paper is to describe how the full-length Spanish Version of the Test of Functional Health Literacy in Adults (TOFHLA-S) scale was adapted to PR. Methods Thirty participants (women = 16, men = 14) completed a basic demographic questionnaire, the TOFHLA-S and participated in an interview. Analyses were performed to examine the information provided by participants and the internal consistency of the TOFHLA-S. Results The mean age was 47.7 years (range 34-77). Thirty-seven percent had less than 12 years of formal schooling and 43% reported having education above high school. Changes suggested by participants included: increasing font size from 14 to 16 points for better readability and changes/simplification of several words in order to make them colloquial and comprehensible for the PR context. The reliability coefficient obtained for this scale was strong (estimated alpha = 0.95) however, differences were observed by subtype: numeracy (estimated alphanum = .819 vs. comprehension (estimated alpha =. 953). Conclusions Based on this process, we have adapted the original version of the TOFHLA-S and the new version of the full-length TOFHLA-S, PR is now valid for further research and testing levels of functional health literacy in a larger sample in PR. PMID:20222334

The Depression Anxiety Stress Scales-21 (DASS-21): further examination of dimensions, scale reliability, and correlates.

PubMed

Osman, Augustine; Wong, Jane L; Bagge, Courtney L; Freedenthal, Stacey; Gutierrez, Peter M; Lozano, Gregorio

2012-12-01

We conducted two studies to examine the dimensions, internal consistency reliability estimates, and potential correlates of the Depression Anxiety Stress Scales-21 (DASS-21; Lovibond & Lovibond, 1995). Participants in Study 1 included 887 undergraduate students (363 men and 524 women, aged 18 to 35 years; mean [M] age = 19.46, standard deviation [SD] = 2.17) recruited from two public universities to assess the specificity of the individual DASS-21 items and to evaluate estimates of internal consistency reliability. Participants in a follow-up study (Study 2) included 410 students (168 men and 242 women, aged 18 to 47 years; M age = 19.65, SD = 2.88) recruited from the same universities to further assess factorial validity and to evaluate potential correlates of the original DASS-21 total and scale scores. Item bifactor and confirmatory factor analyses revealed that a general factor accounted for the greatest proportion of common variance in the DASS-21 item scores (Study 1). In Study 2, the fit statistics showed good fit for the bifactor model. In addition, the DASS-21 total scale score correlated more highly with scores on a measure of mixed depression and anxiety than with scores on the proposed specific scales of depression or anxiety. Coefficient omega estimates for the DASS-21 scale scores were good. Further investigations of the bifactor structure and psychometric properties of the DASS-21, specifically its incremental and discriminant validity, using known clinical groups are needed. © 2012 Wiley Periodicals, Inc.

Effective pore size and radius of capture for K(+) ions in K-channels.

PubMed

Moldenhauer, Hans; Díaz-Franulic, Ignacio; González-Nilo, Fernando; Naranjo, David

2016-02-02

Reconciling protein functional data with crystal structure is arduous because rare conformations or crystallization artifacts occur. Here we present a tool to validate the dimensions of open pore structures of potassium-selective ion channels. We used freely available algorithms to calculate the molecular contour of the pore to determine the effective internal pore radius (r(E)) in several K-channel crystal structures. r(E) was operationally defined as the radius of the biggest sphere able to enter the pore from the cytosolic side. We obtained consistent r(E) estimates for MthK and Kv1.2/2.1 structures, with r(E) = 5.3-5.9 Å and r(E) = 4.5-5.2 Å, respectively. We compared these structural estimates with functional assessments of the internal mouth radii of capture (r(C)) for two electrophysiological counterparts, the large conductance calcium activated K-channel (r(C) = 2.2 Å) and the Shaker Kv-channel (r(C) = 0.8 Å), for MthK and Kv1.2/2.1 structures, respectively. Calculating the difference between r(E) and r(C), produced consistent size radii of 3.1-3.7 Å and 3.6-4.4 Å for hydrated K(+) ions. These hydrated K(+) estimates harmonize with others obtained with diverse experimental and theoretical methods. Thus, these findings validate MthK and the Kv1.2/2.1 structures as templates for open BK and Kv-channels, respectively.

Internally Consistent MODIS Estimate of Aerosol Clear-Sky Radiative Effect Over the Global Oceans

NASA Technical Reports Server (NTRS)

Remer, Lorraine A.; Kaufman, Yoram J.

2004-01-01

Modern satellite remote sensing, and in particular the MODerate resolution Imaging Spectroradiometer (MODIS), offers a measurement-based pathway to estimate global aerosol radiative effects and aerosol radiative forcing. Over the Oceans, MODIS retrieves the total aerosol optical thickness, but also reports which combination of the 9 different aerosol models was used to obtain the retrieval. Each of the 9 models is characterized by a size distribution and complex refractive index, which through Mie calculations correspond to a unique set of single scattering albedo, assymetry parameter and spectral extinction for each model. The combination of these sets of optical parameters weighted by the optical thickness attributed to each model in the retrieval produces the best fit to the observed radiances at the top of the atmosphere. Thus the MODIS Ocean aerosol retrieval provides us with (1) An observed distribution of global aerosol loading, and (2) An internally-consistent, observed, distribution of aerosol optical models that when used in combination will best represent the radiances at the top of the atmosphere. We use these two observed global distributions to initialize the column climate model by Chou and Suarez to calculate the aerosol radiative effect at top of the atmosphere and the radiative efficiency of the aerosols over the global oceans. We apply the analysis to 3 years of MODIS retrievals from the Terra satellite and produce global and regional, seasonally varying, estimates of aerosol radiative effect over the clear-sky oceans.

Design of psychosocial factors questionnaires: a systematic measurement approach

PubMed Central

Vargas, Angélica; Felknor, Sarah A

2012-01-01

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

Reliability and validity of the Modified Erikson Psychosocial Stage Inventory in diverse samples.

PubMed

Leidy, N K; Darling-Fisher, C S

1995-04-01

The Modified Erikson Psychosocial Stage Inventory (MEPSI) is a relatively simple survey measure designed to assess the strength of psychosocial attributes that arise from progression through Erikson's eight stages of development. The purpose of this study was to employ secondary analysis to evaluate the internal-consistency reliability and construct validity of the MEPSI across four diverse samples: healthy young adults, hemophilic men, healthy older adults, and older adults with chronic obstructive pulmonary disease. Special attention was given to the performance of the measure across gender, with exploratory analyses examining possible age cohort and health status effects. Internal-consistency estimates for the aggregate measure were high, whereas subscale reliability levels varied across age groups. Construct validity was supported across samples. Gender, cohort, and health effects offered interesting psychometric and theoretical insights and direction for further research. Findings indicated that the MEPSI might be a useful instrument for operationalizing and testing Eriksonian developmental theory in adults.

Coefficient alpha and interculture test selection.

PubMed

Thurber, Steven; Kishi, Yasuhiro

2014-04-01

The internal consistency reliability of a measure can be a focal point in an evaluation of the potential adequacy of an instrument for adaptation to another cultural setting. Cronbach's alpha (α) coefficient is often used as the statistical index for such a determination. However, alpha presumes a tau-equivalent test and may constitute an inaccurate population estimate for multidimensional tests. These notions are expanded and examined with a Japanese version of a questionnaire on nursing attitudes toward suicidal patients, originally constructed in Sweden using the English language. The English measure was reported to have acceptable internal consistency (α) albeit the dimensionality of the questionnaire was not addressed. The Japanese scale was found to lack tau-equivalence. An alternative to alpha, "composite reliability," was computed and found to be below acceptable standards in magnitude and precision. Implications for research application of the Japanese instrument are discussed. © The Author(s) 2012.

Assessing Occupational Exposure to Chemicals in an International Epidemiological Study of Brain Tumours

PubMed Central

van Tongeren, Martie

2013-01-01

The INTEROCC project is a multi-centre case–control study investigating the risk of developing brain cancer due to occupational chemical and electromagnetic field exposures. To estimate chemical exposures, the Finnish Job Exposure Matrix (FINJEM) was modified to improve its performance in the INTEROCC study and to address some of its limitations, resulting in the development of the INTEROCC JEM. An international team of occupational hygienists developed a crosswalk between the Finnish occupational codes used in FINJEM and the International Standard Classification of Occupations 1968 (ISCO68). For ISCO68 codes linked to multiple Finnish codes, weighted means of the exposure estimates were calculated. Similarly, multiple ISCO68 codes linked to a single Finnish code with evidence of heterogeneous exposure were refined. One of the key time periods in FINJEM (1960–1984) was split into two periods (1960–1974 and 1975–1984). Benzene exposure estimates in early periods were modified upwards. The internal consistency of hydrocarbon exposures and exposures to engine exhaust fumes was improved. Finally, exposure to polycyclic aromatic hydrocarbon and benzo(a)pyrene was modified to include the contribution from second-hand smoke. The crosswalk ensured that the FINJEM exposure estimates could be applied to the INTEROCC study subjects. The modifications generally resulted in an increased prevalence of exposure to chemical agents. This increased prevalence of exposure was not restricted to the lowest categories of cumulative exposure, but was seen across all levels for some agents. Although this work has produced a JEM with important improvements compared to FINJEM, further improvements are possible with the expansion of agents and additional external data. PMID:23467593

Doubly robust matching estimators for high dimensional confounding adjustment.

PubMed

Antonelli, Joseph; Cefalu, Matthew; Palmer, Nathan; Agniel, Denis

2018-05-11

Valid estimation of treatment effects from observational data requires proper control of confounding. If the number of covariates is large relative to the number of observations, then controlling for all available covariates is infeasible. In cases where a sparsity condition holds, variable selection or penalization can reduce the dimension of the covariate space in a manner that allows for valid estimation of treatment effects. In this article, we propose matching on both the estimated propensity score and the estimated prognostic scores when the number of covariates is large relative to the number of observations. We derive asymptotic results for the matching estimator and show that it is doubly robust in the sense that only one of the two score models need be correct to obtain a consistent estimator. We show via simulation its effectiveness in controlling for confounding and highlight its potential to address nonlinear confounding. Finally, we apply the proposed procedure to analyze the effect of gender on prescription opioid use using insurance claims data. © 2018, The International Biometric Society.

Detailed gravity anomalies from GEOS-3 satellite altimetry data

NASA Technical Reports Server (NTRS)

Gopalapillai, G. S.; Mourad, A. G.

1978-01-01

A technique for deriving mean gravity anomalies from dense altimetry data was developed. A combination of both deterministic and statistical techniques was used. The basic mathematical model was based on the Stokes' equation which describes the analytical relationship between mean gravity anomalies and geoid undulations at a point; this undulation is a linear function of the altimetry data at that point. The overdetermined problem resulting from the excessive altimetry data available was solved using Least-Squares principles. These principles enable the simultaneous estimation of the associated standard deviations reflecting the internal consistency based on the accuracy estimates provided for the altimetry data as well as for the terrestrial anomaly data. Several test computations were made of the anomalies and their accuracy estimates using GOES-3 data.

Smoking-attributable burden of lung cancer in the Philippines.

PubMed

Bilano, Ver Luanni Feliciano; Borja, Maridel P; Cruz, Eduardo L; Tan, Alvin G; Mortera, Lalaine L; Reganit, Paul Ferdinand M

2015-05-01

In the Philippines, smoking is highly prevalent and tobacco control policies fail to fully implement the WHO Framework Convention on Tobacco Control provisions. To aid in policy change, intervention implementation, monitoring and evaluation, this study aimed to provide the first internally consistent and latest Philippine estimates of the following: disability-adjusted life-years (DALYs) lost due to lung cancer; population-attributable fractions (PAFs) of smoking; and smoking-attributable lung cancer DALYs. This study applied the Global Burden of Disease and Comparative Risk Assessment frameworks to secondary data, supplemented by expert opinion. A comprehensive internally consistent assessment of disease epidemiology was conducted using DISMOD II and disease impact was quantified as DALYs. PAFs were calculated using the smoking impact ratio and Monte Carlo uncertainty analyses were conducted. For 2008, lung cancer incidence and mortality estimates were 10 871 cases and 9871 deaths respectively. Lung cancer accounted for an estimated 267 787 DALYs lost, 99% of which were due to years of life lost. Overall, the PAF of smoking was 65% and a total of 173 103 DALYs were smoking-attributable. There were increasing trends in incidence, mortality and DALY rates with age. The majority of incidence (72%), mortality (71%) and disease burden (72%) occurred among men, who also had higher PAF estimates. Considerable health gains could be achieved if smoking exposure were reduced in the Philippines. Strong enforcement of measures like increasing taxation to the WHO-endorsed rate, expanding smoke-free environments, and requiring large graphic warnings within a comprehensive tobacco control programme is recommended. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Food composition database development for between country comparisons.

PubMed

Merchant, Anwar T; Dehghan, Mahshid

2006-01-19

Nutritional assessment by diet analysis is a two-stepped process consisting of evaluation of food consumption, and conversion of food into nutrient intake by using a food composition database, which lists the mean nutritional values for a given food portion. Most reports in the literature focus on minimizing errors in estimation of food consumption but the selection of a specific food composition table used in nutrient estimation is also a source of errors. We are conducting a large prospective study internationally and need to compare diet, assessed by food frequency questionnaires, in a comparable manner between different countries. We have prepared a multi-country food composition database for nutrient estimation in all the countries participating in our study. The nutrient database is primarily based on the USDA food composition database, modified appropriately with reference to local food composition tables, and supplemented with recipes of locally eaten mixed dishes. By doing so we have ensured that the units of measurement, method of selection of foods for testing, and assays used for nutrient estimation are consistent and as current as possible, and yet have taken into account some local variations. Using this common metric for nutrient assessment will reduce differential errors in nutrient estimation and improve the validity of between-country comparisons.

Internal Medicine residents use heuristics to estimate disease probability.

PubMed

Phang, Sen Han; Ravani, Pietro; Schaefer, Jeffrey; Wright, Bruce; McLaughlin, Kevin

2015-01-01

Training in Bayesian reasoning may have limited impact on accuracy of probability estimates. In this study, our goal was to explore whether residents previously exposed to Bayesian reasoning use heuristics rather than Bayesian reasoning to estimate disease probabilities. We predicted that if residents use heuristics then post-test probability estimates would be increased by non-discriminating clinical features or a high anchor for a target condition. We randomized 55 Internal Medicine residents to different versions of four clinical vignettes and asked them to estimate probabilities of target conditions. We manipulated the clinical data for each vignette to be consistent with either 1) using a representative heuristic, by adding non-discriminating prototypical clinical features of the target condition, or 2) using anchoring with adjustment heuristic, by providing a high or low anchor for the target condition. When presented with additional non-discriminating data the odds of diagnosing the target condition were increased (odds ratio (OR) 2.83, 95% confidence interval [1.30, 6.15], p = 0.009). Similarly, the odds of diagnosing the target condition were increased when a high anchor preceded the vignette (OR 2.04, [1.09, 3.81], p = 0.025). Our findings suggest that despite previous exposure to the use of Bayesian reasoning, residents use heuristics, such as the representative heuristic and anchoring with adjustment, to estimate probabilities. Potential reasons for attribute substitution include the relative cognitive ease of heuristics vs. Bayesian reasoning or perhaps residents in their clinical practice use gist traces rather than precise probability estimates when diagnosing.

A Comparison Between Internal Waves Observed in the Southern Ocean and Lee Wave Generation Theory

NASA Astrophysics Data System (ADS)

Nikurashin, M.; Benthuysen, J.; Naveira Garabato, A.; Polzin, K. L.

2016-02-01

Direct observations in the Southern Ocean report enhanced internal wave activity and turbulence in a few kilometers above rough bottom topography. The enhancement is co-located with the deep-reaching fronts of the Antarctic Circumpolar Current, suggesting that the internal waves and turbulence are sustained by near-bottom flows interacting with rough topography. Recent numerical simulations confirm that oceanic flows impinging on rough small-scale topography are very effective generators of internal gravity waves and predict vigorous wave radiation, breaking, and turbulence within a kilometer above bottom. However, a linear lee wave generation theory applied to the observed bottom topography and mean flow characteristics has been shown to overestimate the observed rates of the turbulent energy dissipation. In this study, we compare the linear lee wave theory with the internal wave kinetic energy estimated from finestructure data collected as part of the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES). We show that the observed internal wave kinetic energy levels are generally in agreement with the theory. Consistent with the lee wave theory, the observed internal wave kinetic energy scales quadratically with the mean flow speed, stratification, and topographic roughness. The correlation coefficient between the observed internal wave kinetic energy and mean flow and topography parameters reaches 0.6-0.8 for the 100-800 m vertical wavelengths, consistent with the dominant lee wave wavelengths, and drops to 0.2-0.5 for wavelengths outside this range. A better agreement between the lee wave theory and the observed internal wave kinetic energy than the observed turbulent energy dissipation suggests remote breaking of internal waves.

Comparison of type 2 diabetes prevalence estimates in Saudi Arabia from a validated Markov model against the International Diabetes Federation and other modelling studies

PubMed Central

Al-Quwaidhi, Abdulkareem J.; Pearce, Mark S.; Sobngwi, Eugene; Critchley, Julia A.; O’Flaherty, Martin

2014-01-01

Aims To compare the estimates and projections of type 2 diabetes mellitus (T2DM) prevalence in Saudi Arabia from a validated Markov model against other modelling estimates, such as those produced by the International Diabetes Federation (IDF) Diabetes Atlas and the Global Burden of Disease (GBD) project. Methods A discrete-state Markov model was developed and validated that integrates data on population, obesity and smoking prevalence trends in adult Saudis aged ≥25 years to estimate the trends in T2DM prevalence (annually from 1992 to 2022). The model was validated by comparing the age- and sex-specific prevalence estimates against a national survey conducted in 2005. Results Prevalence estimates from this new Markov model were consistent with the 2005 national survey and very similar to the GBD study estimates. Prevalence in men and women in 2000 was estimated by the GBD model respectively at 17.5% and 17.7%, compared to 17.7% and 16.4% in this study. The IDF estimates of the total diabetes prevalence were considerably lower at 16.7% in 2011 and 20.8% in 2030, compared with 29.2% in 2011 and 44.1% in 2022 in this study. Conclusion In contrast to other modelling studies, both the Saudi IMPACT Diabetes Forecast Model and the GBD model directly incorporated the trends in obesity prevalence and/or body mass index (BMI) to inform T2DM prevalence estimates. It appears that such a direct incorporation of obesity trends in modelling studies results in higher estimates of the future prevalence of T2DM, at least in countries where obesity has been rapidly increasing. PMID:24447810

[Indicators of general, cerebral, and regional hemodynamics in myopic schoolchildren aged 13-15 years].

PubMed

Iastrebtseva, T A; Chuprov, A D; Plotnikova, Iu A

2002-01-01

110 schoolchildren aged 13-15 years were examined. 24 of them had pseudomyopia and 6 patients myopia of various forms. A control group consisted of 38 children. Central hemodynamics was estimated by average dynamic pressure, cerebral hemodynamics--by rheoencephalography, regional hemodynamics--by dopplerography of the internal carotid and suprapubic arteries. It was found that with myopia progression, the average dynamic pressure positively comes down with reduction of reographic waves amplitude in rheogram. The blood flow rate in internal carotid and suprapubic arteries has no substantial impact on myopia course. Predisposition to arterial hypotension is a risk factor for myopia development and progression.

Measuring the Wavelength of a Diode Laser and the Birefringence of Mica: The Experimental Examination of the IPHO 40 Held in Mexico

ERIC Educational Resources Information Center

Moran-Lopez, J. L.; Ortiz, M. E.; Rodriguez, L. F.; Romero-Rochin, V.

2010-01-01

The experimental examination applied in the 40th International Physics Olympiad held in Merida, Yucatan, Mexico, is presented. The examination consisted of two parts: (1) based on the measurements of a diffraction pattern produced by a diode laser impinging on a sharp edge of a razor blade, the students were asked to estimate the wavelength of the…

The internal consistency and concurrent validity of the Hopelessness, Helplessness, and Haplessness Scale in a Turkish clinical sample.

PubMed

Vatan, Sevginar; Lester, David

2008-12-01

The aim of this study was to estimate the concurrent validity of the Hopelessness, Helplessness, and Haplessness Scale developed by Lester (1998). Data were obtained from 75 psychiatric patients. Cronbach alphas ranged from .67 to .90. Scores on the scales were associated with Beck, Weissman, Lester, and Trexler's measure of hopelessness, with the correlation strongest for the new hopelessness scale.

Development of a Semi-Autonomous Underwater Vehicle for Intervention Missions (SAUVIM Phase III-B)

DTIC Science & Technology

2009-03-20

burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing...phase 7 people have been working under the SAUVIM project in ASL, consisting of 1 faculty member, 3 full- time researchers, 2 undergraduate interns...and significant time delay inherent in acoustic subsea communications represent a considerable obstacle to remotely operate a manipulation system

A robust design mark-resight abundance estimator allowing heterogeneity in resighting probabilities

USGS Publications Warehouse

McClintock, B.T.; White, Gary C.; Burnham, K.P.

2006-01-01

This article introduces the beta-binomial estimator (BBE), a closed-population abundance mark-resight model combining the favorable qualities of maximum likelihood theory and the allowance of individual heterogeneity in sighting probability (p). The model may be parameterized for a robust sampling design consisting of multiple primary sampling occasions where closure need not be met between primary occasions. We applied the model to brown bear data from three study areas in Alaska and compared its performance to the joint hypergeometric estimator (JHE) and Bowden's estimator (BOWE). BBE estimates suggest heterogeneity levels were non-negligible and discourage the use of JHE for these data. Compared to JHE and BOWE, confidence intervals were considerably shorter for the AICc model-averaged BBE. To evaluate the properties of BBE relative to JHE and BOWE when sample sizes are small, simulations were performed with data from three primary occasions generated under both individual heterogeneity and temporal variation in p. All models remained consistent regardless of levels of variation in p. In terms of precision, the AICc model-averaged BBE showed advantages over JHE and BOWE when heterogeneity was present and mean sighting probabilities were similar between primary occasions. Based on the conditions examined, BBE is a reliable alternative to JHE or BOWE and provides a framework for further advances in mark-resight abundance estimation. ?? 2006 American Statistical Association and the International Biometric Society.

Developing a Danish version of the "Impact on Participation and Autonomy Questionnaire".

PubMed

Ghaziani, Emma; Krogh, Anne Grethe; Lund, Hans

2013-05-01

To translate the "Impact on Participation and Autonomy Questionnaire" into Danish (IPAQ-DK), and estimate its internal consistency and test-retest reliability in order to promote participation-based interventions and research. Translation and two successive reliability assessments through test-retest. 137 adults with varying degrees of impairment; of these, 67 participated in the final reliability assessment. The translation followed guidelines set forth by the "European Group for Quality of Life Assessment and Health Measurement". Internal consistency for subscales was estimated by Chronbach's alpha. Weighted kappa coefficients and intraclass correlation coefficients were calculated to assess the test-retest reliability at item and subscale level, respectively. A preliminary reliability assessment revealed residual issues regarding the translation and cultural adaptation of the instrument. The revised version (IPAQ-DK) was subsequently subjected to a similar assessment demonstrating Chronbach's alpha values from 0.698 to 0.817. Weighted kappa ranged from 0.370 to 0.880; 78% of these values were higher than 0.600. The intraclass correlation coefficient covered values from 0.701 to 0.818. IPAQ-DK is a useful instrument for identifying person-perceived participation restrictions and satisfaction with participation. Further studies of IPAQ-DK's floor/ceiling effects and responsiveness to change are recommended, and whether there is a need for further linguistic improvement of certain items.

Internal consistency and stability of the CANTAB neuropsychological test battery in children.

PubMed

Syväoja, Heidi J; Tammelin, Tuija H; Ahonen, Timo; Räsänen, Pekka; Tolvanen, Asko; Kankaanpää, Anna; Kantomaa, Marko T

2015-06-01

The Cambridge Neuropsychological Test Automated Battery (CANTAB) is a computer-assessed test battery widely use in different populations. The internal consistency and 1-year stability of CANTAB tests were examined in school-age children. Two hundred-thirty children (57% girls) from five schools in the Jyväskylä school district in Finland participated in the study in spring 2011. The children completed the following CANTAB tests: (a) visual memory (pattern recognition memory [PRM] and spatial recognition memory [SRM]), (b) executive function (spatial span [SSP], Stockings of Cambridge [SOC], and intra-extra dimensional set shift [IED]), and (c) attention (reaction time [RTI] and rapid visual information processing [RVP]). Seventy-four children participated in the follow-up measurements (64% girls) in spring 2012. Cronbach's alpha reliability coefficient was used to estimate the internal consistency of the nonhampering test, and structural equation models were applied to examine the stability of these tests. The reliability and the stability could not be determined for IED or SSP because of the nature of these tests. The internal consistency was acceptable only in the RTI task. The 1-year stability was moderate-to-good for the PRM, RTI, and RVP. The SSP and IED showed a moderate correlation between the two measurement points. The SRM and the SOC tasks were not reliable or stable measures in this study population. For research purposes, we recommend using structural equation modeling to improve reliability. The results suggest that the reliability and the stability of computer-based test batteries should be confirmed in the target population before using them for clinical or research purposes. (c) 2015 APA, all rights reserved).

Factor structure and diagnostic efficiency of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for avoidant personality disorder in Hispanic men and women with substance use disorders.

PubMed

Becker, Daniel F; Añez, Luis Miguel; Paris, Manuel; Bedregal, Luis; Grilo, Carlos M

2009-01-01

This study examined the internal consistency, factor structure, and diagnostic efficiency of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), criteria for avoidant personality disorder (AVPD) and the extent to which these metrics may be affected by sex. Subjects were 130 monolingual Hispanic adults (90 men, 40 women) who had been admitted to a specialty clinic that provides psychiatric and substance abuse services to Spanish-speaking patients. All were reliably assessed with the Spanish-Language Version of the Diagnostic Interview for DSM-IV Personality Disorders. The AVPD diagnosis was determined by the best-estimate method. After evaluating internal consistency of the AVPD criterion set, an exploratory factor analysis was performed using principal components extraction. Afterward, diagnostic efficiency indices were calculated for all AVPD criteria. Subsequent analyses examined men and women separately. For the overall group, internal consistency of AVPD criteria was good. Exploratory factor analysis revealed a 1-factor solution (accounting for 70% of the variance), supporting the unidimensionality of the AVPD criterion set. The best inclusion criterion was "reluctance to take risks," whereas "interpersonally inhibited" was the best exclusion criterion and the best predictor overall. When men and women were examined separately, similar results were obtained for both internal consistency and factor structure, with slight variations noted between sexes in the patterning of diagnostic efficiency indices. These psychometric findings, which were similar for men and women, support the construct validity of the DSM-IV criteria for AVPD and may also have implications for the treatment of this particular clinical population.

Consistency of Use and Effectiveness of Household Water Treatment Practices Among Urban and Rural Populations Claiming to Treat Their Drinking Water at Home: A Case Study in Zambia.

PubMed

Rosa, Ghislaine; Kelly, Paul; Clasen, Thomas

2016-02-01

Household water treatment (HWT) can improve drinking water quality and prevent disease, if used correctly and consistently. While international monitoring suggests that 1.8 billion people practice HWT, these estimates are based on household surveys that may overstate the level of consistent use and do not address microbiological effectiveness. We sought to examine how HWT is practiced among households identified as HWT users according to international monitoring standards. Case studies were conducted in urban and rural Zambia. After a baseline survey (urban: 203 households, rural: 276 households) to identify HWT users, 95 urban and 82 rural households were followed up for 6 weeks. Consistency of HWT reporting was low; only 72.6% of urban and 50.0% of rural households reported to be HWT users in the subsequent visit. Similarly, availability of treated water was low, only 23.3% and 4.2% of urban and rural households, respectively, had treated water on all visits. Drinking water was significantly worse than source water in both settings. Only 19.6% of urban and 2.4% of rural households had drinking water free of thermotolerant coliforms on all visits. Our findings raise questions about the value of the data gathered through the international monitoring of HWT practices as predictors of water quality in the home. © The American Society of Tropical Medicine and Hygiene.

Fluffy comets

NASA Astrophysics Data System (ADS)

Greenberg, J. M.

The density of typical comet nuclei is estimated on the basis of published empirical and theoretical density data on meteors. The nuclei are assumed to consist of aggregated interstellar dust (silicate cores with complex organic refractory mantles) as proposed by Greenberg (1982 and 1983) and Van de Bult et al. (1985). The theoretical density (0.5 g/cu cm) of a compact nucleus of this type is contrasted with the observed densities of meteors associated with short-period comets (0.2 g/cu cm) and the Draconids associated with comet Giacobini-Zinner (0.01 g/cu cm), and it is inferred that the original comet debris was less than fully packed. A birdsnest structure comprising elongated crystals and about 60 percent empty space is proposed; its albedo is estimated as about 0.05 (in the range predicted by observations); and it is shown to undergo much less internal heating by the sun than a solid ice nucleus. The mean density of reconstituted cometary matter is found to be in the range 0.54-0.03 g/cu cm, consistent with the estimates (0.1 g/cu cm) of Lin (1966) and Donn (1963).

Bayesian phylogenetic estimation of fossil ages.

PubMed

Drummond, Alexei J; Stadler, Tanja

2016-07-19

Recent advances have allowed for both morphological fossil evidence and molecular sequences to be integrated into a single combined inference of divergence dates under the rule of Bayesian probability. In particular, the fossilized birth-death tree prior and the Lewis-Mk model of discrete morphological evolution allow for the estimation of both divergence times and phylogenetic relationships between fossil and extant taxa. We exploit this statistical framework to investigate the internal consistency of these models by producing phylogenetic estimates of the age of each fossil in turn, within two rich and well-characterized datasets of fossil and extant species (penguins and canids). We find that the estimation accuracy of fossil ages is generally high with credible intervals seldom excluding the true age and median relative error in the two datasets of 5.7% and 13.2%, respectively. The median relative standard error (RSD) was 9.2% and 7.2%, respectively, suggesting good precision, although with some outliers. In fact, in the two datasets we analyse, the phylogenetic estimate of fossil age is on average less than 2 Myr from the mid-point age of the geological strata from which it was excavated. The high level of internal consistency found in our analyses suggests that the Bayesian statistical model employed is an adequate fit for both the geological and morphological data, and provides evidence from real data that the framework used can accurately model the evolution of discrete morphological traits coded from fossil and extant taxa. We anticipate that this approach will have diverse applications beyond divergence time dating, including dating fossils that are temporally unconstrained, testing of the 'morphological clock', and for uncovering potential model misspecification and/or data errors when controversial phylogenetic hypotheses are obtained based on combined divergence dating analyses.This article is part of the themed issue 'Dating species divergences using rocks and clocks'. © 2016 The Authors.

Bayesian phylogenetic estimation of fossil ages

PubMed Central

Drummond, Alexei J.; Stadler, Tanja

2016-01-01

Recent advances have allowed for both morphological fossil evidence and molecular sequences to be integrated into a single combined inference of divergence dates under the rule of Bayesian probability. In particular, the fossilized birth–death tree prior and the Lewis-Mk model of discrete morphological evolution allow for the estimation of both divergence times and phylogenetic relationships between fossil and extant taxa. We exploit this statistical framework to investigate the internal consistency of these models by producing phylogenetic estimates of the age of each fossil in turn, within two rich and well-characterized datasets of fossil and extant species (penguins and canids). We find that the estimation accuracy of fossil ages is generally high with credible intervals seldom excluding the true age and median relative error in the two datasets of 5.7% and 13.2%, respectively. The median relative standard error (RSD) was 9.2% and 7.2%, respectively, suggesting good precision, although with some outliers. In fact, in the two datasets we analyse, the phylogenetic estimate of fossil age is on average less than 2 Myr from the mid-point age of the geological strata from which it was excavated. The high level of internal consistency found in our analyses suggests that the Bayesian statistical model employed is an adequate fit for both the geological and morphological data, and provides evidence from real data that the framework used can accurately model the evolution of discrete morphological traits coded from fossil and extant taxa. We anticipate that this approach will have diverse applications beyond divergence time dating, including dating fossils that are temporally unconstrained, testing of the ‘morphological clock', and for uncovering potential model misspecification and/or data errors when controversial phylogenetic hypotheses are obtained based on combined divergence dating analyses. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’. PMID:27325827

Cross-cultural challenges for assessing medical professionalism among clerkship physicians in a Middle Eastern country (Bahrain): feasibility and psychometric properties of multisource feedback

PubMed Central

Al Ansari, Ahmed; Al Khalifa, Khalid; Al Azzawi, Mohamed; Al Amer, Rashed; Al Sharqi, Dana; Al-Mansoor, Anwar; Munshi, Fadi M

2015-01-01

Background We aimed to design, implement, and evaluate the feasibility and reliability of a multisource feedback (MSF) system to assess interns in their clerkship year in the Middle Eastern culture, the Kingdom of Bahrain. Method The study was undertaken in the Bahrain Defense Force Hospital, a military teaching hospital in the Kingdom of Bahrain. A total of 21 interns (who represent the total population of the interns for the given year) were assessed in this study. All of the interns were rotating through our hospital during their year-long clerkship rotation. The study sample consisted of nine males and 12 females. Each participating intern was evaluated by three groups of raters, eight medical intern colleagues, eight senior medical colleagues, and eight coworkers from different departments. Results A total of 21 interns (nine males and 12 females) were assessed in this study. The total mean response rates were 62.3%. A factor analysis was conducted that found that the data on the questionnaire grouped into three factors that counted for 76.4% of the total variance. These three factors were labeled as professionalism, collaboration, and communication. Reliability analysis indicated that the full instrument scale had high internal consistency (Cronbach’s α 0.98). The generalizability coefficients for the surveys were estimated to be 0.78. Conclusion Based on our results and analysis, we conclude that the MSF tool we used on the interns rotating in their clerkship year within our Middle Eastern culture provides an effective method of evaluation because it offers a reliable, valid, and feasible process. PMID:26316836

Internal curvature signal and noise in low- and high-level vision

PubMed Central

Grabowecky, Marcia; Kim, Yee Joon; Suzuki, Satoru

2011-01-01

How does internal processing contribute to visual pattern perception? By modeling visual search performance, we estimated internal signal and noise relevant to perception of curvature, a basic feature important for encoding of three-dimensional surfaces and objects. We used isolated, sparse, crowded, and face contexts to determine how internal curvature signal and noise depended on image crowding, lateral feature interactions, and level of pattern processing. Observers reported the curvature of a briefly flashed segment, which was presented alone (without lateral interaction) or among multiple straight segments (with lateral interaction). Each segment was presented with no context (engaging low-to-intermediate-level curvature processing), embedded within a face context as the mouth (engaging high-level face processing), or embedded within an inverted-scrambled-face context as a control for crowding. Using a simple, biologically plausible model of curvature perception, we estimated internal curvature signal and noise as the mean and standard deviation, respectively, of the Gaussian-distributed population activity of local curvature-tuned channels that best simulated behavioral curvature responses. Internal noise was increased by crowding but not by face context (irrespective of lateral interactions), suggesting prevention of noise accumulation in high-level pattern processing. In contrast, internal curvature signal was unaffected by crowding but modulated by lateral interactions. Lateral interactions (with straight segments) increased curvature signal when no contextual elements were added, but equivalent interactions reduced curvature signal when each segment was presented within a face. These opposing effects of lateral interactions are consistent with the phenomena of local-feature contrast in low-level processing and global-feature averaging in high-level processing. PMID:21209356

Functional Status Score for the Intensive Care Unit (FSS-ICU): An International Clinimetric Analysis of Validity, Responsiveness, and Minimal Important Difference

PubMed Central

Huang, Minxuan; Chan, Kitty S.; Zanni, Jennifer M.; Parry, Selina M.; Neto, Saint-Clair G. B.; Neto, Jose A. A.; da Silva, Vinicius Z. M.; Kho, Michelle E.; Needham, Dale M.

2017-01-01

Objective To evaluate the internal consistency, validity, responsiveness, and minimal important difference of the Functional Status Score for the Intensive Care Unit (FSS-ICU), a physical function measure designed for the intensive care unit (ICU). Design Clinimetric analysis. Settings Five international data sets from the United States, Australia, and Brazil. Patients 819 ICU patients. Intervention None. Measurements and Main Results Clinimetric analyses were initially conducted separately for each data source and time point to examine generalizability of findings, with pooled analyses performed thereafter to increase power of analyses. The FSS-ICU demonstrated good to excellent internal consistency. There was good convergent and discriminant validity, with significant and positive correlations (r = 0.30 to 0.95) between FSS-ICU and other physical function measures, and generally weaker correlations with non-physical measures (|r| = 0.01 to 0.70). Known group validity was demonstrated by significantly higher FSS-ICU scores among patients without ICU-acquired weakness (Medical Research Council sumscore ≥48 versus <48) and with hospital discharge to home (versus healthcare facility). FSS-ICU at ICU discharge predicted post-ICU hospital length of stay and discharge location. Responsiveness was supported via increased FSS-ICU scores with improvements in muscle strength. Distribution-based methods indicated a minimal important difference of 2.0 to 5.0. Conclusions The FSS-ICU has good internal consistency and is a valid and responsive measure of physical function for ICU patients. The estimated minimal important difference can be used in sample size calculations and in interpreting studies comparing the physical function of groups of ICU patients. PMID:27488220

High inter-rater reliability, agreement, and convergent validity of Constant score in patients with clavicle fractures.

PubMed

Ban, Ilija; Troelsen, Anders; Kristensen, Morten Tange

2016-10-01

The Constant score (CS) has been the primary endpoint in most studies on clavicle fractures. However, the CS was not developed to assess patients with clavicle fractures. Our aim was to examine inter-rater reliability and agreement of the CS in patients with clavicle fractures. The secondary aim was to estimate the correlation between the CS and the Disabilities of the Arm, Shoulder and Hand score and the internal consistency of the 2 scores. On the basis of sample sizing, 36 patients (31 male and 5 female patients; mean age, 41.3 years) with clavicle fractures underwent standardized CS assessment at a mean of 6.8 weeks (SD, 1.0 weeks) after injury. Reliability and agreement of the CS were determined by 2 raters. The interclass correlation coefficient (ICC2,1), standard error of measurement, minimal detectable change, Cronbach α coefficient, and Pearson correlation coefficient were estimated. Inter-rater reliability of the total CS was excellent (interclass correlation coefficient, 0.94; 95% confidence interval, 0.88-0.97), with no systematic difference between the 2 raters (P = .75). The standard error of measurement (measurement error at the group level) was 4.9, whereas the minimal detectable change (smallest change needed to indicate a real change for an individual) was 13.6 CS points. The internal consistency of the 10 CS items was good, with a Cronbach α of .85, and we found a strong correlation (r = -0.92) between the CS and Disabilities of the Arm, Shoulder and Hand score. The CS was found to be reliable for assessing patients with clavicle fractures, especially at the group level. With high inter-rater reliability and agreement, in addition to good internal consistency, the standardized CS used in this study can be used for comparison of results from different settings. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Validation of the German revised version of the program in palliative care education and practice questionnaire (PCEP-GR).

PubMed

Fetz, Katharina; Wenzel-Meyburg, Ursula; Schulz-Quach, Christian

2017-12-28

The evaluation of the effectiveness of undergraduate palliative care education (UPCE) programs is an essential foundation to providing high-quality UPCE programs. Therefore, the implementation of valid evaluation tools is indispensable. Until today, there has been no general consensus regarding concrete outcome parameters and their accurate measurement. The Program in Palliative Care Education and Practice Questionnaire (German Revised Version; PCEP-GR) is a promising assessment tool for UPCE. The aim of the current study was to evaluate the psychometric properties of PCEP-GR and to demonstrate its feasibility for the evaluation of UPCE programs. The practical feasibility of the PCEP-GR and its acceptance in medical students were investigated in a pilot study with 24 undergraduate medical students at Heinrich Heine University Dusseldorf, Germany. Subsequently, the PCEP-GR was surveyed in a representative sample (N = 680) of medical students in order to investigate its psychometric properties. Factorial validity was investigated by means of principal component analysis (PCA). Reliability was examined by means of split-half-reliability analysis and analysis of internal consistency. After taking into consideration the PCA and distribution analysis results, an evaluation instruction for the PCEP-GR was developed. The PCEP-GR proved to be feasible and well-accepted in medical students. PCA revealed a four-factorial solution indicating four PCEP-GR subscales: preparation to provide palliative care, attitudes towards palliative care, self-estimation of competence in communication with dying patients and their relatives and self-estimation of knowledge and skills in palliative care. The PCEP-GR showed good split-half-reliability and acceptable to good internal consistency of subscales. Attitudes towards palliative care slightly missed the criterion of acceptable internal consistency. The evaluation instruction suggests a global PCEP-GR index and four subscales. The PCEP-GR has proven to be a feasible, economic, valid and reliable tool for the assessment of UPCE that comprises self-efficacy expectation and relevant attitudes towards palliative care.

Effective pore size and radius of capture for K+ ions in K-channels

PubMed Central

Moldenhauer, Hans; Díaz-Franulic, Ignacio; González-Nilo, Fernando; Naranjo, David

2016-01-01

Reconciling protein functional data with crystal structure is arduous because rare conformations or crystallization artifacts occur. Here we present a tool to validate the dimensions of open pore structures of potassium-selective ion channels. We used freely available algorithms to calculate the molecular contour of the pore to determine the effective internal pore radius (rE) in several K-channel crystal structures. rE was operationally defined as the radius of the biggest sphere able to enter the pore from the cytosolic side. We obtained consistent rE estimates for MthK and Kv1.2/2.1 structures, with rE = 5.3–5.9 Å and rE = 4.5–5.2 Å, respectively. We compared these structural estimates with functional assessments of the internal mouth radii of capture (rC) for two electrophysiological counterparts, the large conductance calcium activated K-channel (rC = 2.2 Å) and the Shaker Kv-channel (rC = 0.8 Å), for MthK and Kv1.2/2.1 structures, respectively. Calculating the difference between rE and rC, produced consistent size radii of 3.1–3.7 Å and 3.6–4.4 Å for hydrated K+ ions. These hydrated K+ estimates harmonize with others obtained with diverse experimental and theoretical methods. Thus, these findings validate MthK and the Kv1.2/2.1 structures as templates for open BK and Kv-channels, respectively. PMID:26831782

Measuring eating disorder attitudes and behaviors: a reliability generalization study

PubMed Central

2014-01-01

Background Although score reliability is a sample-dependent characteristic, researchers often only report reliability estimates from previous studies as justification for employing particular questionnaires in their research. The present study followed reliability generalization procedures to determine the mean score reliability of the Eating Disorder Inventory and its most commonly employed subscales (Drive for Thinness, Bulimia, and Body Dissatisfaction) and the Eating Attitudes Test as a way to better identify those characteristics that might impact score reliability. Methods Published studies that used these measures were coded based on their reporting of reliability information and additional study characteristics that might influence score reliability. Results Score reliability estimates were included in 26.15% of studies using the EDI and 36.28% of studies using the EAT. Mean Cronbach’s alphas for the EDI (total score = .91; subscales = .75 to .89), EAT-40 (total score = .81) and EAT-26 (total score = .86; subscales = .56 to .80) suggested variability in estimated internal consistency. Whereas some EDI subscales exhibited higher score reliability in clinical eating disorder samples than in nonclinical samples, other subscales did not exhibit these differences. Score reliability information for the EAT was primarily reported for nonclinical samples, making it difficult to characterize the effect of type of sample on these measures. However, there was a tendency for mean score reliability to be higher in the adult (vs. adolescent) samples and in female (vs. male) samples. Conclusions Overall, this study highlights the importance of assessing and reporting internal consistency during every test administration because reliability is affected by characteristics of the participants being examined. PMID:24764530

Modeling individualized coefficient alpha to measure quality of test score data.

PubMed

Liu, Molei; Hu, Ming; Zhou, Xiao-Hua

2018-05-23

Individualized coefficient alpha is defined. It is item and subject specific and is used to measure the quality of test score data with heterogenicity among the subjects and items. A regression model is developed based on 3 sets of generalized estimating equations. The first set of generalized estimating equation models the expectation of the responses, the second set models the response's variance, and the third set is proposed to estimate the individualized coefficient alpha, defined and used to measure individualized internal consistency of the responses. We also use different techniques to extend our method to handle missing data. Asymptotic property of the estimators is discussed, based on which inference on the coefficient alpha is derived. Performance of our method is evaluated through simulation study and real data analysis. The real data application is from a health literacy study in Hunan province of China. Copyright © 2018 John Wiley & Sons, Ltd.

Processing of visual gravitational motion in the peri-sylvian cortex: Evidence from brain-damaged patients.

PubMed

Maffei, Vincenzo; Mazzarella, Elisabetta; Piras, Fabrizio; Spalletta, Gianfranco; Caltagirone, Carlo; Lacquaniti, Francesco; Daprati, Elena

2016-05-01

Rich behavioral evidence indicates that the brain estimates the visual direction and acceleration of gravity quite accurately, and the underlying mechanisms have begun to be unraveled. While the neuroanatomical substrates of gravity direction processing have been studied extensively in brain-damaged patients, to our knowledge no such study exists for the processing of visual gravitational motion. Here we asked 31 stroke patients to intercept a virtual ball moving along the vertical under either natural gravity or artificial reversed gravity. Twenty-seven of them also aligned a luminous bar to the vertical direction (subjective visual vertical, SVV). Using voxel-based lesion-symptom mapping as well as lesion subtraction analysis, we found that lesions mainly centered on the posterior insula are associated with greater deviations of SVV, consistent with several previous studies. Instead, lesions mainly centered on the parietal operculum decrease the ability to discriminate natural from unnatural gravitational acceleration with a timed motor response in the interception task. Both the posterior insula and the parietal operculum belong to the vestibular cortex, and presumably receive multisensory information about the gravity vector. We speculate that an internal model estimating the effects of gravity on visual objects is constructed by transforming the vestibular estimates of mechanical gravity, which are computed in the brainstem and cerebellum, into internalized estimates of virtual gravity, which are stored in the cortical vestibular network. The present lesion data suggest a specific role for the parietal operculum in detecting the mismatch between predictive signals from the internal model and the online visual signals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Personality traits in established schizophrenia: aspects of usability and differences between patients and controls using the Swedish universities Scales of Personality.

PubMed

Fagerberg, Tomas; Söderman, Erik; Gustavsson, J Petter; Agartz, Ingrid; Jönsson, Erik G

2016-08-01

Personality is considered as an important aspect that can affect symptoms and social function in persons with schizophrenia. The personality questionnaire Swedish universities Scales of Personality (SSP) has not previously been used in psychotic disorder. To investigate if SSP has a similar internal consistency and factor structure in a psychosis population as among healthy controls and if patients with psychotic disorders differ from non-psychotic individuals in their responses to the SSP. Patients with psychotic disorders (n = 107) and healthy controls (n = 119) completed SSP. SSP scores were analyzed for internal consistency and case-control differences by Cronbach's alfa and multiple analysis of covariance, respectively. Internal consistencies among patients were overall similar to that of controls. The patients scored significantly higher in seven (Somatic trait anxiety, Psychic trait anxiety, Stress susceptibility, Lack of assertiveness, Detachment, Embitterment, Mistrust) and lower in three (Physical trait aggression, Verbal trait aggression, Adventure seeking) of the 13 scales of the inventory. In three scales (Impulsiveness, Social desirability and Trait irritability) there was no significant difference between the scoring of patients and healthy controls. The reliability estimates suggest that SSP can be used by patients with psychotic disorders in stable remission. Patients score higher on neuroticism-related scales and lower on aggression-related scales than controls, which is in accordance with earlier studies where other personality inventories were used.

Portuguese version of the EUROPEP questionnaire: contributions to the psychometric validation

PubMed Central

Roque, Hugo; Veloso, Ana; Ferreira, Pedro L

2016-01-01

ABSTRACT OBJECTIVE To assess the construct validity and reliability of the Portuguese version of the European Task Force on Patient Evaluation of General Practice Care questionnaire. METHODS We applied the Portuguese version of the European Task Force on Patient Evaluation of General Practice Care to 392 users of 20 Family Health Units from the North of Portugal. The validity of the construct was evaluated by exploratory factor analysis, with the Principal Axis Factoring method, by orthogonal rotation (varimax procedure), by the Kaiser normalization criteria (eigenvalue ≥ 1). The factorability of the data matrix was verified by the Kaiser-Meyer-Olkin and Bartlett’s sphericity test. We estimated the reliability by the indicator of internal consistency Cronbach’s alpha. To analyze the correlations between satisfaction and loyalty, we used the Pearson correlations. The predictor effect of satisfaction on loyalty was analyzed by simple linear regression. RESULTS Satisfaction presented five robust and well individualized dimensions – medical care, nursing care, clinical secretariat services, accessibility, and organization of services – with alpha values between 0.86 and 0.97, good levels of internal consistency. The loyalty showed alpha value of 0.72, considered a reasonable internal consistency. The satisfaction was predictive of loyalty. CONCLUSIONS The Portuguese European Task Force on Patient Evaluation of General Practice Care questionnaire is a robust and reliable instrument to measure the satisfaction and loyalty of users of the Family Health Units. PMID:27706374

NACP Synthesis: Evaluating modeled carbon state and flux variables against multiple observational constraints (Invited)

NASA Astrophysics Data System (ADS)

Thornton, P. E.; Nacp Site Synthesis Participants

2010-12-01

The North American Carbon Program (NACP) synthesis effort includes an extensive intercomparison of modeled and observed ecosystem states and fluxes preformed with multiple models across multiple sites. The participating models span a range of complexity and intended application, while the participating sites cover a broad range of natural and managed ecosystems in North America, from the subtropics to arctic tundra, and coastal to interior climates. A unique characteristic of this collaborative effort is that multiple independent observations are available at all sites: fluxes are measured with the eddy covariance technique, and standard biometric and field sampling methods provide estimates of standing stock and annual production in multiple categories. In addition, multiple modeling approaches are employed to make predictions at each site, varying, for example, in the use of diagnostic vs. prognostic leaf area index. Given multiple independent observational constraints and multiple classes of model, we evaluate the internal consistency of observations at each site, and use this information to extend previously derived estimates of uncertainty in the flux observations. Model results are then compared with all available observations and models are ranked according to their consistency with each type of observation (high frequency flux measurement, carbon stock, annual production). We demonstrate a range of internal consistency across the sites, and show that some models which perform well against one observational metric perform poorly against others. We use this analysis to construct a hypothesis for combining eddy covariance, biometrics, and other standard physiological and ecological measurements which, as data collection proceeded over several years, would present an increasingly challenging target for next generation models.

Internal Medicine residents use heuristics to estimate disease probability

PubMed Central

Phang, Sen Han; Ravani, Pietro; Schaefer, Jeffrey; Wright, Bruce; McLaughlin, Kevin

2015-01-01

Background Training in Bayesian reasoning may have limited impact on accuracy of probability estimates. In this study, our goal was to explore whether residents previously exposed to Bayesian reasoning use heuristics rather than Bayesian reasoning to estimate disease probabilities. We predicted that if residents use heuristics then post-test probability estimates would be increased by non-discriminating clinical features or a high anchor for a target condition. Method We randomized 55 Internal Medicine residents to different versions of four clinical vignettes and asked them to estimate probabilities of target conditions. We manipulated the clinical data for each vignette to be consistent with either 1) using a representative heuristic, by adding non-discriminating prototypical clinical features of the target condition, or 2) using anchoring with adjustment heuristic, by providing a high or low anchor for the target condition. Results When presented with additional non-discriminating data the odds of diagnosing the target condition were increased (odds ratio (OR) 2.83, 95% confidence interval [1.30, 6.15], p = 0.009). Similarly, the odds of diagnosing the target condition were increased when a high anchor preceded the vignette (OR 2.04, [1.09, 3.81], p = 0.025). Conclusions Our findings suggest that despite previous exposure to the use of Bayesian reasoning, residents use heuristics, such as the representative heuristic and anchoring with adjustment, to estimate probabilities. Potential reasons for attribute substitution include the relative cognitive ease of heuristics vs. Bayesian reasoning or perhaps residents in their clinical practice use gist traces rather than precise probability estimates when diagnosing. PMID:27004080

The GEWEX Integrated Product - An Assessment of the Terrestrial Water Cycle from Satellite Observations and Reanalysis

NASA Astrophysics Data System (ADS)

Kummerow, C.; Brown, P.

2017-12-01

The GEWEX Data and Assessments Paned (GDAP) has been working on a set of consistent products describing the water and energy budgets as well as fluxes at high spatial (1°) and temporal (3hr) resolution. Unlike individual products, the GEWEX Integrated product is careful to make assumptions consistent among algorithms and use internally derived parameters from one product (e.g. clouds from the ISCCP) as input to all other products requiring cloud information. This product was developed with two goals in mind: The first was to validate individual assumptions by cross-checking them with other products within the water and energy budget and ultimately verifying closure of the water and energy budgets within the uncertainties of each algorithm. With the recent completion of the first version of the GEWEX Integrated product, this talk will offer a first look at the consistency among the products insofar as the terrestrial water budget is concerned. Satellite observations of evaporation and precipitation will be compared to atmospheric water vapor divergences from ERA-Interim for various regions, and time scales to assess consistency among the individual estimates. The second goal was to make a available to the community, an internally consistent product that could be used to better understand climate processes and feedback. The status of this will also be discussed.

Combining nutation and surface gravity observations to estimate the Earth's core and inner core resonant frequencies

NASA Astrophysics Data System (ADS)

Ziegler, Yann; Lambert, Sébastien; Rosat, Séverine; Nurul Huda, Ibnu; Bizouard, Christian

2017-04-01

Nutation time series derived from very long baseline interferometry (VLBI) and time varying surface gravity data recorded by superconducting gravimeters (SG) have long been used separately to assess the Earth's interior via the estimation of the free core and inner core resonance effects on nutation or tidal gravity. The results obtained from these two techniques have been shown recently to be consistent, making relevant the combination of VLBI and SG observables and the estimation of Earth's interior parameters in a single inversion. We present here the intermediate results of the ongoing project of combining nutation and surface gravity time series to improve estimates of the Earth's core and inner core resonant frequencies. We use VLBI nutation time series spanning 1984-2016 derived by the International VLBI Service for geodesy and astrometry (IVS) as the result of a combination of inputs from various IVS analysis centers, and surface gravity data from about 15 SG stations. We address here the resonance model used for describing the Earth's interior response to tidal excitation, the data preparation consisting of the error recalibration and amplitude fitting for nutation data, and processing of SG time-varying gravity to remove any gaps, spikes, steps and other disturbances, followed by the tidal analysis with the ETERNA 3.4 software package, the preliminary estimates of the resonant periods, and the correlations between parameters.

Experience gained in operation of the VLF ATD lightning location system

NASA Technical Reports Server (NTRS)

Lee, Anthony C. L.

1991-01-01

The United Kingdom (UK) Meteorological Office's Very Low Frequency (VLF) Arrival Time Difference (ATD) System for long-range location of lightning flashes started automatic international issue of lightning-location products on 17 Jun. 1988. Data from before and after this formal start-date were carefully scrutinized to judge performance. Techniques for estimating location accuracy include internal consistency and comparisons against other systems. Other areas studied were range (up to several thousand km); detection efficiency, saturation effects in active situations, and communication difficulties (for this redundant system); and spurious fix rate. Care was taken to assess the potential of the system, in addition to identifying the operational difficulties of the present implementation.

Magmatic oxygen fugacity estimated using zircon-melt partitioning of cerium

NASA Astrophysics Data System (ADS)

Smythe, Duane J.; Brenan, James M.

2016-11-01

Using a newly-calibrated relation for cerium redox equilibria in silicate melts (Smythe and Brenan, 2015), and an internally-consistent model for zircon-melt partitioning of Ce, we provide a method to estimate the prevailing redox conditions during crystallization of zircon-saturated magmas. With this approach, oxygen fugacities were calculated for samples from the Bishop tuff (USA), Toba tuff (Indonesia) and the Nain plutonic suite (Canada), which typically agree with independent estimates within one log unit or better. With the success of reproducing the fO2 of well-constrained igneous systems, we have applied our Ce-in-zircon oxygen barometer to estimating the redox state of Earth's earliest magmas. Using the composition of the Jack Hills Hadean zircons, combined with estimates of their parental magma composition, we determined the fO2 during zircon crystallization to be between FMQ -1.0 to +2.5 (where FMQ is the fayalite-magnetite-quartz buffer). Of the parental magmas considered, Archean tonalite-trondhjemite-granodiorite (TTG) compositions yield zircon-melt partitioning most similar to well-constrained modern suites (e.g., Sano et al., 2002). Although broadly consistent with previous redox estimates from the Jack Hills zircons, our results provide a more precise determination of fO2, narrowing the range for Hadean parental magmas by more than 8 orders of magnitude. Results suggest that relatively oxidized magmatic source regions, similar in oxidation state to that of 3.5 Ga komatiite suites, existed by ∼4.4 Ga.

Doubly robust estimation of generalized partial linear models for longitudinal data with dropouts.

PubMed

Lin, Huiming; Fu, Bo; Qin, Guoyou; Zhu, Zhongyi

2017-12-01

We develop a doubly robust estimation of generalized partial linear models for longitudinal data with dropouts. Our method extends the highly efficient aggregate unbiased estimating function approach proposed in Qu et al. (2010) to a doubly robust one in the sense that under missing at random (MAR), our estimator is consistent when either the linear conditional mean condition is satisfied or a model for the dropout process is correctly specified. We begin with a generalized linear model for the marginal mean, and then move forward to a generalized partial linear model, allowing for nonparametric covariate effect by using the regression spline smoothing approximation. We establish the asymptotic theory for the proposed method and use simulation studies to compare its finite sample performance with that of Qu's method, the complete-case generalized estimating equation (GEE) and the inverse-probability weighted GEE. The proposed method is finally illustrated using data from a longitudinal cohort study. © 2017, The International Biometric Society.

Relative contribution of organs other than brain to resting energy expenditure is consistent among male power athletes.

PubMed

Oshima, Satomi; Miyauchi, Sakiho; Asaka, Meiko; Kawano, Hiroshi; Taguchi, Motoko; Torii, Suguru; Higuchi, Mitsuru

2013-01-01

We have previously shown that resting energy expenditure (REE) adjusted by fat-free mass (FFM) in male college athletes remains consistent regardless of FFM. The FFM comprises internal organs with high metabolic activity, such as liver and brain, which account for 60 to 80% of REE in adults. The purpose of the present study is to examine the contribution of internal organs to the REE of the FFM fraction among male power athletes. The study included 37 American male college football players. REE was measured by indirect calorimetry and body composition was measured by dual energy X-ray absorptiometry (DXA). Mass of brain, liver, and kidneys was measured by MRI and mass of heart was estimated by echocardiography. Normal levels of thyroid hormone (triiodothyronine: T3) were confirmed in all subjects prior to the analysis. Multiple regression analysis was used to assess the influence of FFM, fat mass (FM), T3, and mass of organs on variance of REE. Average body weight and FFM were 81.2±11.3 kg and 67.7±7.4 kg, respectively. The relative contributions of liver, kidneys, and heart to REE were consistent regardless of FFM, while the REE of brain was negatively correlated with FFM (r=-0.672, p<0.001). Only FFM and T3 were found to be independent factors influencing REE. These results suggest that a steady contribution of internal organs other than the brain is the major reason for the consistency of the REE/FFM ratio in male power athletes.

Psychometric properties of the Purpose-In-Life Test and age-related differences among women diagnosed with eating disorders.

PubMed

García-Alandete, Joaquín; Ros, Montserrat Cañabate; Salvador, José Heliodoro Marco; Rodríguez, Sandra Pérez

2018-03-01

The aim of this study was to analyze the psychometric properties of the Purpose-In-Life Test (PIL), as well as the age-related differences in meaning in life in women diagnosed with eating disorders. Participants were 250 Spanish women diagnosed with eating disorders who ranged from 12 to 60 years old. Confirmatory Factor Analysis, descriptive analyses, estimation of the internal consistency of the PIL, correlations between the PIL and the Beck Hopelessness Scale (BHS), Overweight Preoccupation Scale (OPS), and Body Investment Scale (BIS), and age differences were calculated. A 19-item model that showed a good fit and internal consistency, a negative correlation between the PIL and both the BHS and OPS, and a positive correlation with the BIS, as well as significant differences between the adolescents and the mature adults, were found. It would be advisable to increase the inclusion of meaning in life in psychotherapeutic interventions with women diagnosed with eating disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

On estimation of time-dependent attributable fraction from population-based case-control studies.

PubMed

Zhao, Wei; Chen, Ying Qing; Hsu, Li

2017-09-01

Population attributable fraction (PAF) is widely used to quantify the disease burden associated with a modifiable exposure in a population. It has been extended to a time-varying measure that provides additional information on when and how the exposure's impact varies over time for cohort studies. However, there is no estimation procedure for PAF using data that are collected from population-based case-control studies, which, because of time and cost efficiency, are commonly used for studying genetic and environmental risk factors of disease incidences. In this article, we show that time-varying PAF is identifiable from a case-control study and develop a novel estimator of PAF. Our estimator combines odds ratio estimates from logistic regression models and density estimates of the risk factor distribution conditional on failure times in cases from a kernel smoother. The proposed estimator is shown to be consistent and asymptotically normal with asymptotic variance that can be estimated empirically from the data. Simulation studies demonstrate that the proposed estimator performs well in finite sample sizes. Finally, the method is illustrated by a population-based case-control study of colorectal cancer. © 2017, The International Biometric Society.

Current profile redistribution driven by neutral beam injection in a reversed-field pinch

NASA Astrophysics Data System (ADS)

Parke, E.; Anderson, J. K.; Brower, D. L.; Den Hartog, D. J.; Ding, W. X.; Johnson, C. A.; Lin, L.

2016-05-01

Neutral beam injection in reversed-field pinch (RFP) plasmas on the Madison Symmetric Torus [Dexter et al., Fusion Sci. Technol. 19, 131 (1991)] drives current redistribution with increased on-axis current density but negligible net current drive. Internal fluctuations correlated with tearing modes are observed on multiple diagnostics; the behavior of tearing mode correlated structures is consistent with flattening of the safety factor profile. The first application of a parametrized model for island flattening to temperature fluctuations in an RFP allows inferrence of rational surface locations for multiple tearing modes. The m = 1, n = 6 mode is observed to shift inward by 1.1 ± 0.6 cm with neutral beam injection. Tearing mode rational surface measurements provide a strong constraint for equilibrium reconstruction, with an estimated reduction of q0 by 5% and an increase in on-axis current density of 8% ± 5%. The inferred on-axis current drive is consistent with estimates of fast ion density using TRANSP [Goldston et al., J. Comput. Phys. 43, 61 (1981)].

TRAC-P1: an advanced best estimate computer program for PWR LOCA analysis. I. Methods, models, user information, and programming details

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

Not Available

1978-05-01

The Transient Reactor Analysis Code (TRAC) is being developed at the Los Alamos Scientific Laboratory (LASL) to provide an advanced ''best estimate'' predictive capability for the analysis of postulated accidents in light water reactors (LWRs). TRAC-Pl provides this analysis capability for pressurized water reactors (PWRs) and for a wide variety of thermal-hydraulic experimental facilities. It features a three-dimensional treatment of the pressure vessel and associated internals; two-phase nonequilibrium hydrodynamics models; flow-regime-dependent constitutive equation treatment; reflood tracking capability for both bottom flood and falling film quench fronts; and consistent treatment of entire accident sequences including the generation of consistent initial conditions.more » The TRAC-Pl User's Manual is composed of two separate volumes. Volume I gives a description of the thermal-hydraulic models and numerical solution methods used in the code. Detailed programming and user information is also provided. Volume II presents the results of the developmental verification calculations.« less

Consistent Measurement and Physical Character of the DSD: Disdrometer to Satellite

NASA Technical Reports Server (NTRS)

Petersen, Walt; Thurai, Merhala; Gatlin, Patrick; Tokay, Ali; Morris, Bob; Wolff, David; Pippitt, Jason; Marks, David; Berendes, Todd

2017-01-01

Objective: Validate GPM (Global Precipitation Measurement) Drop Size Distribution Retrievals: Drop size distributions (DSD) are critical to GPM DPR (Dual-frequency Precipitation Radar)-based rainfall retrievals; NASA GPM Science Requirements stipulate that the GPM Core observatory radar estimation of D (sub m) (mean diameter) shall be within plus or minus 0.5 millimeters of GV (Ground Validation); GV translates disdrometer measurements to polarimetric radar-based DSD and precipitation type retrievals (e.g., convective vs. stratiform (C/S)) for coincident match-up to GPM core overpasses; How well do we meet the requirement across product versions, rain types (e.g., C/S partitioning), and rain rates (heavy, light) and is behavior physically and internally consistent?

Titan's interior from its rotation axis orientation and its Love number

NASA Astrophysics Data System (ADS)

Baland, Rose-Marie; Gabriel, Tobie; Axel, Lefèvre

2013-04-01

The tidal Love number k2 of Titan has been recently estimated from Cassini flybys radio-tracking and is consistent with the presence of a global ocean in Titan's interior, located between two ice layers (Iess et al. 2012), in accordance with prediction from interior and evolutionary models for Titan. Previously, the orientation of the rotation axis of Titan has been measured on the basis of radar images from Cassini (Stiles et al. 2008). Titan's obliquity, is about 0.3. The measured orientation is more consistent with the presence of a global internal liquid ocean than with an entirely solid Titan (Baland et al. 2011). The global topography data of Titan seem to indicate some departure from the hydrostatic shape expected for a synchronous satellite under the influence of its rotation and the static tides raised by the central planet (Zebker et al. 2009). This may be explained by a differential tidal heating in the ice shell which flattens the poles (Nimmo and Bills 2010). A surface more flattened than expected implies compensation in depth to explain the measured gravity coefficients C20 and C22 of Iess et al. (2012). Here, all layers are assumed to have a tri-axial ellipsoid shape, but with polar and equatorial flattenings that differ from the hydrostatic expected ones. We assess the influence of this non-hydrostatic shape on the conclusions of Baland et al. (2011), which developped a Cassini state model for the orientation of the rotation axis of a synchronous satellite having an internal liquid layer. We assess the possibility to constrain Titan's interior (and particularly the structure of the water/ice layer) from both the rotation axis orientation and the Love number. We consider a range of internal structure models consistent with the mean density and the mean radius of Titan, and made of a shell, an ocean, a mantle, and a core, from the surface to the center, with various possible compositions (e.g. ammonia mixed with water for the ocean). The internal structure models consistent with the measured orientation of the rotation axis and Love number still have to be examined with respect to other constrains, such as the shell thickness estimation derived from electric-field measurement of the Huyges probe (Béghin et al. 2012) and the expected temperature profile of the water/ice layer. For instance, a thin shell would imply a rather thick ocean, based on water (or water/ammonia) phase diagram.

Thermodynamics-based Metabolite Sensitivity Analysis in metabolic networks.

PubMed

Kiparissides, A; Hatzimanikatis, V

2017-01-01

The increasing availability of large metabolomics datasets enhances the need for computational methodologies that can organize the data in a way that can lead to the inference of meaningful relationships. Knowledge of the metabolic state of a cell and how it responds to various stimuli and extracellular conditions can offer significant insight in the regulatory functions and how to manipulate them. Constraint based methods, such as Flux Balance Analysis (FBA) and Thermodynamics-based flux analysis (TFA), are commonly used to estimate the flow of metabolites through genome-wide metabolic networks, making it possible to identify the ranges of flux values that are consistent with the studied physiological and thermodynamic conditions. However, unless key intracellular fluxes and metabolite concentrations are known, constraint-based models lead to underdetermined problem formulations. This lack of information propagates as uncertainty in the estimation of fluxes and basic reaction properties such as the determination of reaction directionalities. Therefore, knowledge of which metabolites, if measured, would contribute the most to reducing this uncertainty can significantly improve our ability to define the internal state of the cell. In the present work we combine constraint based modeling, Design of Experiments (DoE) and Global Sensitivity Analysis (GSA) into the Thermodynamics-based Metabolite Sensitivity Analysis (TMSA) method. TMSA ranks metabolites comprising a metabolic network based on their ability to constrain the gamut of possible solutions to a limited, thermodynamically consistent set of internal states. TMSA is modular and can be applied to a single reaction, a metabolic pathway or an entire metabolic network. This is, to our knowledge, the first attempt to use metabolic modeling in order to provide a significance ranking of metabolites to guide experimental measurements. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

International comparison of observation-specific spatial buffers: maximizing the ability to estimate physical activity.

PubMed

Frank, Lawrence D; Fox, Eric H; Ulmer, Jared M; Chapman, James E; Kershaw, Suzanne E; Sallis, James F; Conway, Terry L; Cerin, Ester; Cain, Kelli L; Adams, Marc A; Smith, Graham R; Hinckson, Erica; Mavoa, Suzanne; Christiansen, Lars B; Hino, Adriano Akira F; Lopes, Adalberto A S; Schipperijn, Jasper

2017-01-23

Advancements in geographic information systems over the past two decades have increased the specificity by which an individual's neighborhood environment may be spatially defined for physical activity and health research. This study investigated how different types of street network buffering methods compared in measuring a set of commonly used built environment measures (BEMs) and tested their performance on associations with physical activity outcomes. An internationally-developed set of objective BEMs using three different spatial buffering techniques were used to evaluate the relative differences in resulting explanatory power on self-reported physical activity outcomes. BEMs were developed in five countries using 'sausage,' 'detailed-trimmed,' and 'detailed,' network buffers at a distance of 1 km around participant household addresses (n = 5883). BEM values were significantly different (p < 0.05) for 96% of sausage versus detailed-trimmed buffer comparisons and 89% of sausage versus detailed network buffer comparisons. Results showed that BEM coefficients in physical activity models did not differ significantly across buffering methods, and in most cases BEM associations with physical activity outcomes had the same level of statistical significance across buffer types. However, BEM coefficients differed in significance for 9% of the sausage versus detailed models, which may warrant further investigation. Results of this study inform the selection of spatial buffering methods to estimate physical activity outcomes using an internationally consistent set of BEMs. Using three different network-based buffering methods, the findings indicate significant variation among BEM values, however associations with physical activity outcomes were similar across each buffering technique. The study advances knowledge by presenting consistently assessed relationships between three different network buffer types and utilitarian travel, sedentary behavior, and leisure-oriented physical activity outcomes.

Validation of the Brazilian Portuguese Version of Geriatric Anxiety Inventory--GAI-BR.

PubMed

Massena, Patrícia Nitschke; de Araújo, Narahyana Bom; Pachana, Nancy; Laks, Jerson; de Pádua, Analuiza Camozzato

2015-07-01

The Geriatric Anxiety Inventory (GAI) is a recently developed scale aiming to evaluate symptoms of anxiety in later life. This 20-item scale uses dichotomous answers highlighting non-somatic anxiety complaints of elderly people. The present study aimed to evaluate the psychometric properties of the Brazilian Portuguese version GAI (GAI-BR) in a sample from community and outpatient psychogeriatric clinic. A mixed convenience sample of 72 subjects was recruited for answering the research protocol. The interview procedures were structured with questionnaires about sociodemographic data, clinical health status, anxiety, and depression previously validated instruments, Mini-Mental State Examination, Mini International Neuropsychiatric Interview, and GAI-BR. Twenty-two percent of the sample were interviewed twice for test-retest reliability. For internal consistency analyses, the Cronbach's α test was applied. The Spearman correlation test was applied to evaluate the test-retest GAI-BR reliability. A ROC (receiver operating characteristic) curve study was made to estimate the GAI-BR area under curve, cut-off points, sensitivity, and specificity for the Generalized Anxiety Disorder diagnosis. The GAI-BR version showed high internal consistency (Cronbach's α = 0.91) and strong and significant test-retest reliability (ρ = 0.85, p < 0.001). It also showed moderate and significant correlation with the Beck Anxiety Inventory (ρ = 0.68, p < 0.001) and the State-Trait Anxiety Inventory (ρ = 0.61, p < 0.001) showing evidence of concurrent validation. The cut-off point of 13 estimated by ROC curve analyses showed sensitivity of 83.3% and specificity of 84.6% to detect Generalized Anxiety Disorder (DSM-IV). GAI-BR has demonstrated very good psychometric properties and can be a reliable instrument to measure anxiety in Brazilian elderly people.

International Classification of Functioning, Disability and Health categories explored for self-rated participation in Swedish adolescents and adults with a mild intellectual disability.

PubMed

Arvidsson, Patrik; Granlund, Mats; Thyberg, Ingrid; Thyberg, Mikael

2012-06-01

To explore internal consistency and correlations between perceived ability, performance and perceived importance in a preliminary selection of self-reported items representing the activity/participation component of the International Classification of Functioning, Disability and Health (ICF). Structured interview study. Fifty-five Swedish adolescents and adults with a mild intellectual disability. Questions about perceived ability, performance and perceived importance were asked on the basis of a 3-grade Likert-scale regarding each of 68 items representing the 9 ICF domains of activity/participation. Internal consistency for perceived ability (Cronbach's alpha for all 68 items): 0.95 (values for each domain varied between 0.57 and 0.85), for performance: 0.86 (between 0.27 and 0.66), for perceived importance: 0.84 (between 0.27 and 0.68). Seventy-two percent of the items showed correlations >0.5 (mean=0.59) for performance vs perceived importance, 41% >0.5 (mean=0.47) for perceived ability vs performance and 12% >0.5 (mean=0.28) for perceived ability vs perceived importance. Measures of performance and perceived importance may have to be based primarily on their estimated clinical relevance for describing aspects of the ICF participation concept. With a clinimetric approach, parts of the studied items and domains may be used to investigate factors related to different patterns and levels of participation, and outcomes of rehabilitation.

Psychometric properties and cross-cultural adaptation of the Brazilian Quebec back pain disability scale questionnaire.

PubMed

Rodrigues, Marcelo F; Michel-Crosato, Edgard; Cardoso, Jefferson R; Traebert, Jefferson

2009-06-01

Cross-cultural translation and psychometric testing. To translate and cross-culturally adapt the Quebec Back Pain Disability Scale (QDS) to Brazilian Portuguese and to examine its validity and reliability. Current literature shows the need to adopt reliable and internationally standardized methods for the analysis of low back pain. To our knowledge, this specific questionnaire has not been translated and validated for Portuguese-speaking patients. The translation and cross-cultural adaptation of the QDS were developed in agreement with internationally recommended methodology, and the resulting product was evaluated in this study with 54 consecutive patients. Internal consistency was obtained through Cronbach's alpha; reliability was estimated through the intraclass correlation coefficient and the Bland and Altman agreement (d = mean difference). Validity was determined by correlating the scores of the Brazil-QDS with the Brazilian version of the Roland-Morris Questionnaire and Visual Analogue Pain Scale by means of the Spearman rank correlation coefficient. The internal consistency obtained was excellent (Cronbach's alpha = 0.97). Intraobserver and interobserver reliability were considered strong (ICC = 0.93-d = 0.68 and 0.96-d = 0.57, respectively). The correlation with Brazilian Roland-Morris Questionnaire and with the Visual Analogue Scale was high (r = 0.857; r = 0.758, respectively). The data showed that the process of translation and cross-cultural adaptation were successful and that the adapted instrument demonstrated excellent psychometric properties.

The Rights of Children on the Move and the Budapest Declaration.

PubMed

Oberg, Charles

2018-05-17

It has been estimated that more than 50,000,000 children and youth have migrated across borders or been forcibly displaced within their own country. They consist of refugees, asylum seekers, internally displaced persons (IDP), economic migrants, and exploited trafficked children. They are virtually "stateless", children deprived of the protective structures of state and family that they need and deserve and unrecognized by either their country of origin or the international community. This opinion piece starts with the personal reflections of its author on his recent work in Middle East refugee camps. It then explores the prevalence and demographics of these children and their plight. It examines the United Nation's Convention on the Rights of the Child (CRC) and other international conventions designed to protect them. It also summarizes the International Society of Social Pediatrics and Child Health (ISSOP) Budapest Declaration on the Rights, Health and Well-Being of Children and Youth on the Move as a vehicle for improved care and vehicle for change.

The Rights of Children on the Move and the Budapest Declaration

PubMed Central

2018-01-01

It has been estimated that more than 50,000,000 children and youth have migrated across borders or been forcibly displaced within their own country. They consist of refugees, asylum seekers, internally displaced persons (IDP), economic migrants, and exploited trafficked children. They are virtually “stateless”, children deprived of the protective structures of state and family that they need and deserve and unrecognized by either their country of origin or the international community. This opinion piece starts with the personal reflections of its author on his recent work in Middle East refugee camps. It then explores the prevalence and demographics of these children and their plight. It examines the United Nation’s Convention on the Rights of the Child (CRC) and other international conventions designed to protect them. It also summarizes the International Society of Social Pediatrics and Child Health (ISSOP) Budapest Declaration on the Rights, Health and Well-Being of Children and Youth on the Move as a framework for improved care and vehicle for change. PMID:29772813

Joint eigenvector estimation from mutually anisotropic tensors improves susceptibility tensor imaging of the brain, kidney, and heart.

PubMed

Dibb, Russell; Liu, Chunlei

2017-06-01

To develop a susceptibility-based MRI technique for probing microstructure and fiber architecture of magnetically anisotropic tissues-such as central nervous system white matter, renal tubules, and myocardial fibers-in three dimensions using susceptibility tensor imaging (STI) tools. STI can probe tissue microstructure, but is limited by reconstruction artifacts because of absent phase information outside the tissue and noise. STI accuracy may be improved by estimating a joint eigenvector from mutually anisotropic susceptibility and relaxation tensors. Gradient-recalled echo image data were simulated using a numerical phantom and acquired from the ex vivo mouse brain, kidney, and heart. Susceptibility tensor data were reconstructed using STI, regularized STI, and the proposed algorithm of mutually anisotropic and joint eigenvector STI (MAJESTI). Fiber map and tractography results from each technique were compared with diffusion tensor data. MAJESTI reduced the estimated susceptibility tensor orientation error by 30% in the phantom, 36% in brain white matter, 40% in the inner medulla of the kidney, and 45% in myocardium. This improved the continuity and consistency of susceptibility-based fiber tractography in each tissue. MAJESTI estimation of the susceptibility tensors yields lower orientation errors for susceptibility-based fiber mapping and tractography in the intact brain, kidney, and heart. Magn Reson Med 77:2331-2346, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Borderline personality disorder subscale (Chinese version) of the structured clinical interview for DSM-IV axis II personality disorders: a validation study in Cantonese-speaking Hong Kong Chinese.

PubMed

Wong, H M; Chow, L Y

2011-06-01

Borderline personality disorder is an important but under-recognised clinical entity, for which there are only a few available diagnostic instruments in the Chinese language. None has been tested for its psychometric properties in the Cantonese-speaking population in Hong Kong. The present study aimed to assess the validity of the Chinese version of the Borderline Personality Disorder subscale of the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders Axis II Personality Disorders (SCID-II) in Cantonese-speaking Hong Kong Chinese. A convenience sampling method was used. The subjects were seen by a multidisciplinary clinical team, who arrived at a best-estimate diagnosis and then by application of the SCID-II rater using the Chinese version of the Borderline Personality Disorder subscale. The study was carried out at the psychiatric clinic of the Prince of Wales Hospital in Hong Kong. A total of 87 patients of Chinese ethnicity aged 18 to 64 years who attended the clinic in April 2007 were recruited. The aforementioned patient parameters were used to examine the internal consistency, best-estimate clinical diagnosis-SCID diagnosis agreement, sensitivity, and specificity of the Chinese version of the subscale. The Borderline Personality Disorder subscale (Chinese version) of SCID-II had an internal consistency of 0.82 (Cronbach's alpha coefficient), best-estimate clinical diagnosis-SCID diagnosis agreement of 0.82 (kappa), sensitivity of 0.92, and specificity of 0.94. The Borderline Personality Disorder subscale (Chinese version) of the SCID-II rater had reasonable validity when applied to Cantonese-speaking Chinese subjects in Hong Kong.

Effects of varied doses of psilocybin on time interval reproduction in human subjects.

PubMed

Wackermann, Jirí; Wittmann, Marc; Hasler, Felix; Vollenweider, Franz X

2008-04-11

Action of a hallucinogenic substance, psilocybin, on internal time representation was investigated in two double-blind, placebo-controlled studies: Experiment 1 with 12 subjects and graded doses, and Experiment 2 with 9 subjects and a very low dose. The task consisted in repeated reproductions of time intervals in the range from 1.5 to 5s. The effects were assessed by parameter kappa of the 'dual klepsydra' model of internal time representation, fitted to individual response data and intra-individually normalized with respect to initial values. The estimates kappa were in the same order of magnitude as in earlier studies. In both experiments, kappa was significantly increased by psilocybin at 90 min from the drug intake, indicating a higher loss rate of the internal duration representation. These findings are tentatively linked to qualitative alterations of subjective time in altered states of consciousness.

Summary of Resources for the International Space Station Environmental Control and Life Support System

NASA Technical Reports Server (NTRS)

Williams, David E.

2003-01-01

The assembly complete Environmental Control and Life Support (ECLS) s ystem for the International Space Station (ISS) will consist of compo nents and subsystems in both the U.S. and International partner eleme nts which together will perform the functions of Temperature and Hum idity Control (THC), Atmosphere Control and Supply (ACS), Atmosphere Revitalization (AR), Water Recovery and Management (WRM), Fire Detect ion and Suppression (FDS), and Vacuum System (VS) for the station. D ue to limited resources available on ISS, detailed attention is given to minimizing and tracking all resources associated with all systems , beginning with estimates during the hardware development phase thr ough measured actuals when flight hardware is built and delivered. A summary of resources consumed by the current on-orbit U.S. ECLS syste m hardware is presented, including launch weight, average continuous and peak power loads, on-orbit volume and resupply logistics. ..

Summary of Resources for the International Space Station Environmental Control and Life Support System For Core Complete Modules

NASA Technical Reports Server (NTRS)

Williams, David E.

2004-01-01

The Core Complete Environmental Control and Life Support (ECLS) System for the International Space Station (ISS) will consist of components and subsystems in both the United States (U.S.) and International Partner elements which together will perform the functions of Temperature and Humidity Control (THC), Atmosphere Control and Supply (ACS), Atmosphere Revitalization (AR), Water Recovery and Management (WRM), Fire Detection and Suppression (FDS), and Vacuum System (VS) for the station. Due to limited resources available on ISS, detailed attention is given to minimizing and tracking all resources associated with all systems, beginning with estimates during the hardware development phase through measured actuals when flight hardware is built and delivered. A summary of resources consumed by the addition of future U.S. ECLS system hardware to get to Core Complete is presented, including launch weight, average continuous and peak power loads, on-orbit volume and resupply logistics.

On the interpretation of energy and energy fluxes of nonlinear internal waves: An example from Massachusetts Bay

USGS Publications Warehouse

Scotti, A.; Beardsley, R.; Butman, B.

2006-01-01

A self-consistent formalism to estimate baroclinic energy densities and fluxes resulting from the propagation of internal waves of arbitrary amplitude is derived using the concept of available potential energy. The method can be applied to numerical, laboratory or field data. The total energy flux is shown to be the sum of the linear energy flux ??? u??? p??? dz (primes denote baroclinic quantities), plus contributions from the non-hydrostatic pressure anomaly and the self-advection of kinetic and available potential energy. Using highly resolved observations in Massachusetts Bay, it is shown that due to the presence of nonlinear internal waves periodically propagating in the area, ??? u??? p??? dz accounts for only half of the total flux. The same data show that equipartition of available potential and kinetic energy can be violated, especially when the nonlinear waves begin to interact with the bottom. ?? 2006 Cambridge University Press.

Apparent and internal validity of a Monte Carlo-Markov model for cardiovascular disease in a cohort follow-up study.

PubMed

Nijhuis, Rogier L; Stijnen, Theo; Peeters, Anna; Witteman, Jacqueline C M; Hofman, Albert; Hunink, M G Myriam

2006-01-01

To determine the apparent and internal validity of the Rotterdam Ischemic heart disease & Stroke Computer (RISC) model, a Monte Carlo-Markov model, designed to evaluate the impact of cardiovascular disease (CVD) risk factors and their modification on life expectancy (LE) and cardiovascular disease-free LE (DFLE) in a general population (hereinafter, these will be referred to together as (DF)LE). The model is based on data from the Rotterdam Study, a cohort follow-up study of 6871 subjects aged 55 years and older who visited the research center for risk factor assessment at baseline (1990-1993) and completed a follow-up visit 7 years later (original cohort). The transition probabilities and risk factor trends used in the RISC model were based on data from 3501 subjects (the study cohort). To validate the RISC model, the number of simulated CVD events during 7 years' follow-up were compared with the observed number of events in the study cohort and the original cohort, respectively, and simulated (DF)LEs were compared with the (DF)LEs calculated from multistate life tables. Both in the study cohort and in the original cohort, the simulated distribution of CVD events was consistent with the observed number of events (CVD deaths: 7.1% v. 6.6% and 7.4% v. 7.6%, respectively; non-CVD deaths: 11.2% v. 11.5% and 12.9% v. 13.0%, respectively). The distribution of (DF)LEs estimated with the RISC model consistently encompassed the (DF)LEs calculated with multistate life tables. The simulated events and (DF)LE estimates from the RISC model are consistent with observed data from a cohort follow-up study.

Psychometric evaluation of the Nursing Stress Scale (NSS) among Chinese nurses in Taiwan.

PubMed

Lee, Mei-Hua; Holzemer, William L; Faucett, Julia

2007-01-01

The purpose of this study was to translate the Nursing Stress Scale (NSS) into Chinese and test its reliability and validity among Chinese nurses in Taiwan. Potential participants were asked to self-administer a Chinese version of the NSS. The agreement estimation was used to determine the equivalence of the meaning between the Chinese and original English versions and was rated by five bilingual nurses as 92% accurate for the 34 items. The test-retest reliability for the NSS at 2 weeks was .71 (p = .022, n=10). Internal consistency reliability and factor analysis were tested with 770 nurses from 65 inpatient units at a medical center in Taiwan. The internal consistency of the Chinese version of the NSS for an overall coefficient alpha is .91 for the total scale, and ranges from .67 to .79 for the subscales. The Chinese version of the NSS explains 53.77% of the variance in work stressors among Chinese nurses in Taiwan. Overall, the Chinese version of the NSS is internally consistent but may not be stable over 2 weeks. There was adequate evidence of the reliability and validity of the NSS-Chinese as an instrument appropriate to measure work stress among Chinese nurses. The translated NSS could be a useful tool for examining the frequency and major sources of stress experienced by Chinese nurses in hospital settings, and for the development of appropriate interventions for stress reduction.

Measuring teacher self-report on classroom practices: Construct validity and reliability of the Classroom Strategies Scale-Teacher Form.

PubMed

Reddy, Linda A; Dudek, Christopher M; Fabiano, Gregory A; Peters, Stephanie

2015-12-01

This article presents information about the construct validity and reliability of a new teacher self-report measure of classroom instructional and behavioral practices (the Classroom Strategies Scales-Teacher Form; CSS-T). The theoretical underpinnings and empirical basis for the instructional and behavioral management scales are presented. Information is provided about the construct validity, internal consistency, test-retest reliability, and freedom from item-bias of the scales. Given previous investigations with the CSS Observer Form, it was hypothesized that internal consistency would be adequate and that confirmatory factor analyses (CFA) of CSS-T data from 293 classrooms would offer empirical support for the CSS-T's Total, Composite and subscales, and yield a similar factor structure to that of the CSS Observer Form. Goodness-of-fit indices of χ2/df, Root Mean Square Error of Approximation, Goodness of Fit Index, and Adjusted Goodness of Fit Index suggested satisfactory fit of proposed CFA models whereas the Comparative Fit Index did not. Internal consistency estimates of .93 and .94 were obtained for the Instructional Strategies and Behavioral Strategies Total scales respectively. Adequate test-retest reliability was found for instructional and behavioral total scales (r = .79, r = .84, percent agreement 93% and 93%). The CSS-T evidences freedom from item bias on important teacher demographics (age, educational degree, and years of teaching experience). Implications of results are discussed. (c) 2015 APA, all rights reserved).

Personality traits in established schizophrenia: aspects of usability and differences between patients and controls using the Swedish universities Scales of Personality

PubMed Central

Fagerberg, Tomas; Söderman, Erik; Gustavsson, J. Petter; Agartz, Ingrid; Jönsson, Erik G.

2016-01-01

Abstract Background: Personality is considered as an important aspect that can affect symptoms and social function in persons with schizophrenia. The personality questionnaire Swedish universities Scales of Personality (SSP) has not previously been used in psychotic disorder. Aims: To investigate if SSP has a similar internal consistency and factor structure in a psychosis population as among healthy controls and if patients with psychotic disorders differ from non-psychotic individuals in their responses to the SSP. Methods: Patients with psychotic disorders (n = 107) and healthy controls (n = 119) completed SSP. SSP scores were analyzed for internal consistency and case-control differences by Cronbach’s alfa and multiple analysis of covariance, respectively. Results: Internal consistencies among patients were overall similar to that of controls. The patients scored significantly higher in seven (Somatic trait anxiety, Psychic trait anxiety, Stress susceptibility, Lack of assertiveness, Detachment, Embitterment, Mistrust) and lower in three (Physical trait aggression, Verbal trait aggression, Adventure seeking) of the 13 scales of the inventory. In three scales (Impulsiveness, Social desirability and Trait irritability) there was no significant difference between the scoring of patients and healthy controls. Conclusion: The reliability estimates suggest that SSP can be used by patients with psychotic disorders in stable remission. Patients score higher on neuroticism-related scales and lower on aggression-related scales than controls, which is in accordance with earlier studies where other personality inventories were used. PMID:27103375

Bridging the gap between financial reporting and the revenue cycle.

PubMed

Clark, Kari; Bang, Derek A

2012-09-01

Implementing a standardized financial reporting and revenue cycle monitoring platform can help healthcare organizations improve their net revenue reporting and budgeting processes. Consistent, standardized data help the finance office estimate accounts receivable reserves more accurately, streamline the month-end closing process, and strengthen internal controls. The benefits of standardizing the finance and revenue cycle functions are particularly significant in large organizations with multiple facilities, but even single-facility providers can benefit from improved communication between the business office and finance.

An introduction to g methods.

PubMed

Naimi, Ashley I; Cole, Stephen R; Kennedy, Edward H

2017-04-01

Robins' generalized methods (g methods) provide consistent estimates of contrasts (e.g. differences, ratios) of potential outcomes under a less restrictive set of identification conditions than do standard regression methods (e.g. linear, logistic, Cox regression). Uptake of g methods by epidemiologists has been hampered by limitations in understanding both conceptual and technical details. We present a simple worked example that illustrates basic concepts, while minimizing technical complications. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

Factor information retrieval system version 2. 0 (fire) (for microcomputers). Software

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

Not Available

FIRE Version 2.0 contains EPA's unique recommended criteria and toxic air emission estimation factors. FIRE consists of: (1) an EPA internal repository system that contains emission factor data identified and collected, and (2) an external distribution system that contains only EPA's recommended factors. The emission factors, compiled from a review of the literature, are identified by pollutant name, CAS number, process and emission source descriptions, SIC code, SCC, and control status. The factors are rated for quality using AP-42 rating criteria.

Major International R and D Ranges and Test Facilities. Summary of Capabilities

DTIC Science & Technology

1990-01-01

with a maximum impulse of firing of large numbers of rounds by a weapon in order to 1500 G and a maximum test item weight of 200 pounds. produce...millimetres may be fired safely, using test item weight of 1,000 pounds. training practice or training practice tracer ammunition. The :ange butts consist of...predictions of coherent sound propagation loss in the ocean. This information is useful in estimating the performance of low-frequency passive sonars

Construct validity of the Free and Cued Selective Reminding Test in older adults with memory complaints.

PubMed

Clerici, Francesca; Ghiretti, Roberta; Di Pucchio, Alessandra; Pomati, Simone; Cucumo, Valentina; Marcone, Alessandra; Vanacore, Nicola; Mariani, Claudio; Cappa, Stefano Francesco

2017-06-01

The Free and Cued Selective Reminding Test (FCSRT) is the memory test recommended by the International Working Group on Alzheimer's disease (AD) for the detection of amnestic syndrome of the medial temporal type in prodromal AD. Assessing the construct validity and internal consistency of the Italian version of the FCSRT is thus crucial. The FCSRT was administered to 338 community-dwelling participants with memory complaints (57% females, age 74.5 ± 7.7 years), including 34 with AD, 203 with Mild Cognitive Impairment, and 101 with Subjective Memory Impairment. Internal Consistency was estimated using Cronbach's alpha coefficient. To assess convergent validity, five FCSRT scores (Immediate Free Recall, Immediate Total Recall, Delayed Free Recall, Delayed Total Recall, and Index of Sensitivity of Cueing) were correlated with three well-validated memory tests: Story Recall, Rey Auditory Verbal Learning test, and Rey Complex Figure (RCF) recall (partial correlation analysis). To assess divergent validity, a principal component analysis (an exploratory factor analysis) was performed including, in addition to the above-mentioned memory tasks, the following tests: Word Fluencies, RCF copy, Clock Drawing Test, Trail Making Test, Frontal Assessment Battery, Raven Coloured Progressive Matrices, and Stroop Colour-Word Test. Cronbach's alpha coefficients for immediate recalls (IFR and ITR) and delayed recalls (DFR and DTR) were, respectively, .84 and .81. All FCSRT scores were highly correlated with those of the three well-validated memory tests. The factor analysis showed that the FCSRT does not load on the factors saturated by non-memory tests. These findings indicate that the FCSRT has a good internal consistency and has an excellent construct validity as an episodic memory measure. © 2015 The British Psychological Society.

Cross-cultural adaptation, reliability, internal consistency and validation of the Hand Function Sort (HFS©) for French speaking patients with upper limb complaints.

PubMed

Konzelmann, M; Burrus, C; Hilfiker, R; Rivier, G; Deriaz, O; Luthi, F

2015-03-01

Functional evaluation of upper limb is not only based on clinical findings but requires self-administered questionnaires to address patients' perspective. The Hand Function Sort (HFS©) was only validated in English. The aim of this study was the French cross cultural adaptation and validation of the HFS© (HFS-F). 150 patients with various upper limbs impairments were recruited in a rehabilitation center. Translation and cross-cultural adaptation were made according to international guidelines. Construct validity was estimated through correlations with Disabilities Arm Shoulder and Hand (DASH) questionnaire, SF-36 mental component summary (MCS),SF-36 physical component summary (PCS) and pain intensity. Internal consistency was assessed by Cronbach's α and test-retest reliability by intraclass correlation. Cronbach's α was 0.98, test-retest reliability was excellent at 0.921 (95 % CI 0.871-0.971) same as original HFS©. Correlations with DASH were-0.779 (95 % CI -0.847 to -0.685); with SF 36 PCS 0.452 (95 % CI 0.276-0.599); with pain -0.247 (95 % CI -0.429 to -0.041); with SF 36 MCS 0.242 (95 % CI 0.042-0.422). There were no floor or ceiling effects. The HFS-F has the same good psychometric properties as the original HFS© (internal consistency, test retest reliability, convergent validity with DASH, divergent validity with SF-36 MCS, and no floor or ceiling effects). The convergent validity with SF-36 PCS was poor; we found no correlation with pain. The HFS-F could be used with confidence in a population of working patients. Other studies are necessary to study its psychometric properties in other populations.

Construction of a memory battery for computerized administration, using item response theory.

PubMed

Ferreira, Aristides I; Almeida, Leandro S; Prieto, Gerardo

2012-10-01

In accordance with Item Response Theory, a computer memory battery with six tests was constructed for use in the Portuguese adult population. A factor analysis was conducted to assess the internal structure of the tests (N = 547 undergraduate students). According to the literature, several confirmatory factor models were evaluated. Results showed better fit of a model with two independent latent variables corresponding to verbal and non-verbal factors, reproducing the initial battery organization. Internal consistency reliability for the six tests were alpha = .72 to .89. IRT analyses (Rasch and partial credit models) yielded good Infit and Outfit measures and high precision for parameter estimation. The potential utility of these memory tasks for psychological research and practice willbe discussed.

Radiation Physics for Space and High Altitude Air Travel

NASA Technical Reports Server (NTRS)

Cucinotta, F. A.; Wilson, J. W.; Goldhagen, P.; Saganti, P.; Shavers, M. R.; McKay, Gordon A. (Technical Monitor)

2000-01-01

Galactic cosmic rays (GCR) are of extra-solar origin consisting of high-energy hydrogen, helium, and heavy ions. The GCR are modified by physical processes as they traverse through the solar system, spacecraft shielding, atmospheres, and tissues producing copious amounts of secondary radiation including fragmentation products, neutrons, mesons, and muons. We discuss physical models and measurements relevant for estimating biological risks in space and high-altitude air travel. Ambient and internal spacecraft computational models for the International Space Station and a Mars mission are discussed. Risk assessment is traditionally based on linear addition of components. We discuss alternative models that include stochastic treatments of columnar damage by heavy ion tracks and multi-cellular damage following nuclear fragmentation in tissue.

What influences midwives in estimating labour pain?

PubMed

Williams, A C de C; Morris, J; Stevens, K; Gessler, S; Cella, M; Baxter, J

2013-01-01

Clinicians' estimates of patients' pain are frequently used as a basis for delivering care, and the characteristics of the clinician and of the patient influence this estimate. We studied pain estimation by midwives attending women in uncomplicated labour. Sixty-six practising midwives of varied age, ethnicity and professional experience were asked to complete a trait empathy measure and then to estimate the maximum pain and anxiety experienced by six women whose filmed labour contractions they viewed. Additionally, they rated similarity to the labouring women in ethnicity, and described their beliefs about pain expression according to ethnicity. Midwife estimates of pain and anxiety were highly correlated. Longer professional experience was associated with lower pain estimates, while more births to the midwife herself was associated with higher pain estimates. A multiple regression model identified number of births to the midwife herself, and two components of empathy (perspective taking and identification), to be important in predicting midwife pain estimates for women in labour. Midwives expressed clear beliefs about women's expression of pain during labour according to ethnicity, but these beliefs were not consistent across midwives, even between midwives of similar ethnicity. Midwives' personal characteristics can bias the estimation of pain in woman in labour and therefore influence treatment. © 2012 European Federation of International Association for the Study of Pain Chapters.

Performance of internal covariance estimators for cosmic shear correlation functions

DOE PAGES

Friedrich, O.; Seitz, S.; Eifler, T. F.; ...

2015-12-31

Data re-sampling methods such as the delete-one jackknife are a common tool for estimating the covariance of large scale structure probes. In this paper we investigate the concepts of internal covariance estimation in the context of cosmic shear two-point statistics. We demonstrate how to use log-normal simulations of the convergence field and the corresponding shear field to carry out realistic tests of internal covariance estimators and find that most estimators such as jackknife or sub-sample covariance can reach a satisfactory compromise between bias and variance of the estimated covariance. In a forecast for the complete, 5-year DES survey we show that internally estimated covariance matrices can provide a large fraction of the true uncertainties on cosmological parameters in a 2D cosmic shear analysis. The volume inside contours of constant likelihood in themore » $$\\Omega_m$$-$$\\sigma_8$$ plane as measured with internally estimated covariance matrices is on average $$\\gtrsim 85\\%$$ of the volume derived from the true covariance matrix. The uncertainty on the parameter combination $$\\Sigma_8 \\sim \\sigma_8 \\Omega_m^{0.5}$$ derived from internally estimated covariances is $$\\sim 90\\%$$ of the true uncertainty.« less

Cross-Cultural Adaptation of the Profile Fitness Mapping Neck Questionnaire to Brazilian Portuguese: Internal Consistency, Reliability, and Construct and Structural Validity.

PubMed

Ferreira, Mariana Cândido; Björklund, Martin; Dach, Fabiola; Chaves, Thais Cristina

The purpose of this study was to adapt and evaluate the psychometric properties of the ProFitMap-neck to Brazilian Portuguese. The cross-cultural adaptation consisted of 5 stages, and 180 female patients with chronic neck pain participated in the study. A subsample (n = 30) answered the pretest, and another subsample (n = 100) answered the questionnaire a second time. Internal consistency, test-retest reliability, and construct validity (hypothesis testing and structural validity) were estimated. For construct validity, the scores of the questionnaire were correlated with the Neck Disability Index (NDI), and the Hospital Anxiety and Depression Scale (HADS), the Tampa Scale of Kinesiophobia (TSK), and the 36-item Short-Form Health Survey (SF-36). Internal consistency was determined by adequate Cronbach's α values (α > 0.70). Strong reliability was identified by high intraclass correlation coefficients (ICC > 0.75). Construct validity was identified by moderate and strong correlations of the Br-ProFitMap-neck with total NDI score (-0.56 50%, Kaiser-Meyer-Olkin index > 0.50, eigenvalue > 1, and factor loadings > 0.2. Br-ProFitMap-neck had adequate psychometric properties and can be used in clinical settings, as well as research, in patients with chronic neck pain. Copyright © 2017. Published by Elsevier Inc.

Internal representations reveal cultural diversity in expectations of facial expressions of emotion.

PubMed

Jack, Rachael E; Caldara, Roberto; Schyns, Philippe G

2012-02-01

Facial expressions have long been considered the "universal language of emotion." Yet consistent cultural differences in the recognition of facial expressions contradict such notions (e.g., R. E. Jack, C. Blais, C. Scheepers, P. G. Schyns, & R. Caldara, 2009). Rather, culture--as an intricate system of social concepts and beliefs--could generate different expectations (i.e., internal representations) of facial expression signals. To investigate, they used a powerful psychophysical technique (reverse correlation) to estimate the observer-specific internal representations of the 6 basic facial expressions of emotion (i.e., happy, surprise, fear, disgust, anger, and sad) in two culturally distinct groups (i.e., Western Caucasian [WC] and East Asian [EA]). Using complementary statistical image analyses, cultural specificity was directly revealed in these representations. Specifically, whereas WC internal representations predominantly featured the eyebrows and mouth, EA internal representations showed a preference for expressive information in the eye region. Closer inspection of the EA observer preference revealed a surprising feature: changes of gaze direction, shown primarily among the EA group. For the first time, it is revealed directly that culture can finely shape the internal representations of common facial expressions of emotion, challenging notions of a biologically hardwired "universal language of emotion."

Earth Core and Inner Core: What Can We Learn From a Bayesian Inversion of Combined Nutation and Surface Gravimetry Data?

NASA Astrophysics Data System (ADS)

Lambert, S. B.; Ziegler, Y.; Rosat, S.; Bizouard, C.

2017-12-01

Nutation time series derived from very long baseline interferometry (VLBI) and time varying surface gravity data recorded by superconducting gravimeters (SG) have long been used separately to assess the Earth's interior via the estimation of the free core and inner core resonance effects on nutation or tidal gravity. The results obtained from these two techniques have shown recently to be consistent, making relevant the combination of VLBI and SG observables and the estimation of Earth's interior parameters in a single inversion. We present here the results of combining nutation and surface gravity time series to improve estimates of the Earth's core and inner core resonant frequencies. We use VLBI nutation time series spanning 1984-2016 derived by several analysis centers affiliated to the International VLBI Service for Geodesy and Astrometry, together with surface gravity data from about 15 SG stations. We address the resonance model used for describing the Earth's interior response to tidal excitation, the data preparation consisting of the error recalibration and amplitude fitting to nutation data, and processing of SG time-varying gravity to remove any gaps, spikes, steps and other disturbances, followed by the tidal analysis with the ETERNA 3.4 software package. New estimates of the resonant periods are proposed and correlations between the parameters are investigated.

The probable continuum between emplacement of plutons and mare volcanism in lunar crustal evolution

NASA Technical Reports Server (NTRS)

Pieters, Carle M.

1991-01-01

A scenario for the formation of the Moon is advanced and is argued to be consistent with both known data and the leading hypothesis regarding the formation of the Moon. It is concluded that, although the volume of mare basalts is estimated to be only 0.1 percent of the lunar total, this value should not be taken to represent the amount of partial melt produced within the lunar interior, nor should the mare basalts be viewed as representing the only products of internal heating. The actual amount of magnetic activity is certain to be substantially larger, but cannot be estimated without a global assessment of lunar highland heterogeneity and the character, scale, and abundance of lunar plutons.

The estimation of material and patch parameters in a PDE-based circular plate model

NASA Technical Reports Server (NTRS)

Banks, H. T.; Smith, Ralph C.; Brown, D. E.; Metcalf, Vern L.; Silcox, R. J.

1995-01-01

The estimation of material and patch parameters for a system involving a circular plate, to which piezoceramic patches are bonded, is considered. A partial differential equation (PDE) model for the thin circular plate is used with the passive and active contributions form the patches included in the internal and external bending moments. This model contains piecewise constant parameters describing the density, flexural rigidity, Poisson ratio, and Kelvin-Voigt damping for the system as well as patch constants and a coefficient for viscous air damping. Examples demonstrating the estimation of these parameters with experimental acceleration data and a variety of inputs to the experimental plate are presented. By using a physically-derived PDE model to describe the system, parameter sets consistent across experiments are obtained, even when phenomena such as damping due to electric circuits affect the system dynamics.

Foot placement relies on state estimation during visually guided walking.

PubMed

Maeda, Rodrigo S; O'Connor, Shawn M; Donelan, J Maxwell; Marigold, Daniel S

2017-02-01

As we walk, we must accurately place our feet to stabilize our motion and to navigate our environment. We must also achieve this accuracy despite imperfect sensory feedback and unexpected disturbances. In this study we tested whether the nervous system uses state estimation to beneficially combine sensory feedback with forward model predictions to compensate for these challenges. Specifically, subjects wore prism lenses during a visually guided walking task, and we used trial-by-trial variation in prism lenses to add uncertainty to visual feedback and induce a reweighting of this input. To expose altered weighting, we added a consistent prism shift that required subjects to adapt their estimate of the visuomotor mapping relationship between a perceived target location and the motor command necessary to step to that position. With added prism noise, subjects responded to the consistent prism shift with smaller initial foot placement error but took longer to adapt, compatible with our mathematical model of the walking task that leverages state estimation to compensate for noise. Much like when we perform voluntary and discrete movements with our arms, it appears our nervous systems uses state estimation during walking to accurately reach our foot to the ground. Accurate foot placement is essential for safe walking. We used computational models and human walking experiments to test how our nervous system achieves this accuracy. We find that our control of foot placement beneficially combines sensory feedback with internal forward model predictions to accurately estimate the body's state. Our results match recent computational neuroscience findings for reaching movements, suggesting that state estimation is a general mechanism of human motor control. Copyright © 2017 the American Physiological Society.

Internal Dynamics and Crustal Evolution of Mars

NASA Technical Reports Server (NTRS)

Zuber, Maria

2005-01-01

The objective of this work is to improve understanding of the internal structure, crustal evolution, and thermal history of Mars by combining geophysical data analysis of topography, gravity and magnetics with results from analytical and computational modeling. Accomplishments thus far in this investigation include: (1) development of a new crustal thickness model that incorporates constraints from Mars meteorites, corrections for polar cap masses and other surface loads, Pratt isostasy, and core flattening; (2) determination of a refined estimate of crustal thickness of Mars from geoid/topography ratios (GTRs); (3) derivation of a preliminary estimate of the k(sub 2) gravitational Love number and a preliminary estimate of possible dissipation within Mars consistent with this value; and (4) an integrative analysis of the sequence of evolution of early Mars. During the remainder of this investigation we will: (1) extend models of degree-1 mantle convection from 2-D to 3-D; (2) investigate potential causal relationships and effects of major impacts on mantle plume formation, with primary application to Mars; (3) develop exploratory models to assess the convective stability of various Martian core states as relevant to the history of dynamo action; and (4) develop models of long-wavelength relaxation of crustal thickness anomalies to potentially explain the degree-1 structure of the Martian crust.

Introducing English and German versions of the Adolescent Time Attitude Scale.

PubMed

Worrell, Frank C; Mello, Zena R; Buhl, Monika

2013-08-01

In this study, the authors report on the development of English and German versions of the Adolescent Time Attitude Scale (ATAS). The ATAS consists of six subscales assessing Past Positive, Past Negative, Present Positive, Present Negative, Future Positive, and Future Negative time attitudes. The authors describe the development of the scales and present data on the reliability and structural validity of ATAS scores in samples of American (N = 300) and German (N = 316) adolescents. Internal consistency estimates for scores on the English and German versions of the ATAS were in the .70 to .80 range. Confirmatory factor analyses indicated that a six-factor structure yielded the best fit for scores and that the scores were invariant across samples.

A 4 π dilepton spectrometer: PEPSI

NASA Astrophysics Data System (ADS)

Buda, A.; Bacelar, J. C. S.; Bałanda, A.; van Klinken, J.; Sujkowski, Z.; van der Woude, A.

1993-11-01

A novel positron-electron pair spectroscopy instrument (PEPSI) was designed to measure transitions in the energy region 10-40 MeV. It consists of Nd 2Fe 14B permanent magnets forming a compact 4 π magnetic filter consisting of 12 positron and 20 electron mini-orange-like spectrometers. The response function of PEPSI has been measured with mono-energetic beams of electrons from 5 to 20 MeV. The PEPSI spectrometer was used for measuring the internal pair conversion coefficient ( απ) of the 15.1 MeV M1 transition from a Jπ = 1 + state to the ground state in 12C. Our experimental value of απ = (3.3 ± 0.5) × 10 -3 is in good agreement with theoretical estimates.

A generic biokinetic model for noble gases with application to radon

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

Leggett, Richard Wayne; Marsh, James; Gregoratto, Demetrio

The International Commission for Radiological Protection (ICRP) currently uses a dose conversion coefficient to calculate effective dose per unit exposure to radon and its progeny. The coefficient is derived by dividing the detriment associated with unit exposure to radon, as estimated from epidemiological studies, by the detriment per unit effective dose, as estimated mainly from atomic bomb survivor data and animal studies. In a recent statement the ICRP indicated that future guidance on exposure to radon and its progeny will be developed in the same way as guidance for any other radionuclide. That is, intake of radon and progeny willmore » be limited on the basis of effective dose coefficients derived from biokinetic and dosimetric models. This paper proposes a biokinetic model for systemic (absorbed) radon for use in the calculation of dose coefficients for inhaled or ingested radon. The model is based largely on physical laws governing transfer of a non-reactive and soluble gas between materials. Model predictions are shown to be consistent with results of controlled studies of the fate of internally deposited radon in human subjects.« less

Low Copy Numbers of DC-SIGN in Cell Membrane Microdomains: Implications for Structure and Function

PubMed Central

Liu, Ping; Wang, Xiang; Itano, Michelle S.; Neumann, Aaron K.; de Silva, Aravinda M.; Jacobson, Ken; Thompson, Nancy L.

2014-01-01

Presently, there are few estimates of the number of molecules occupying membrane domains. Using a total internal reflection fluorescence microscopy (TIRFM) imaging approach, based on comparing the intensities of fluorescently labeled microdomains with those of single fluorophores, we measured the occupancy of DC-SIGN, a C-type lectin, in membrane microdomains. DC-SIGN or its mutants were labeled with primary monoclonal antibodies (mAbs) in either dendritic cells (DCs) or NIH3T3 cells, or expressed as GFP fusions in NIH3T3 cells. The number of DC-SIGN molecules per microdomain ranges from only a few to over 20, while microdomain dimensions range from the diffraction limit to > 1μm. The largest fraction of microdomains, appearing at the diffraction limit, in either immature DCs or 3T3 cells contains only 4-8 molecules of DC-SIGN, consistent with our preliminary super-resolution Blink microscopy estimates. We further show that these small assemblies are sufficient to bind and efficiently internalize a small (~50nm) pathogen, dengue virus, leading to infection of host cells. PMID:24313910

Estimation of interfacial area in a packed cross-flow cascade with distillation of ethanol-water, methanol-water, and hexane-heptane

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

Velaga, A.

1986-01-01

Packed cross-flow internals consisting of four and ten stages including the samplers for liquid and vapor were fabricated to fit into the existing distillation column. Experiments were conducted using methanol-water, ethanol-water and hexane-heptane binary mixtures. The experimental data were collected for compositions of inlet and exist streams of cross-flow stages. The overall gas phase height transfer units (H/sub og/) were estimated using the experimental data. H/sub og/ values were compared to those of counter current conditions. The individual mass transfer coefficients in the liquid and vapor phases were estimated using the collected experimental data for degree of separation, flow ratesmore » and physical properties of the binary system used. The physical properties were estimated at an average temperature of the specific cross-flow stage. The mass transfer coefficients were evaluated using three different correlations proposed by Shulman. Onda and Hayashi respectively. The interfacial areas were estimated using the evaluated mass transfer coefficients and the experimental data at each stage of the column for different runs and compared.« less

Methods to assess geological CO2 storage capacity: Status and best practice

USGS Publications Warehouse

Heidug, Wolf; Brennan, Sean T.; Holloway, Sam; Warwick, Peter D.; McCoy, Sean; Yoshimura, Tsukasa

2013-01-01

To understand the emission reduction potential of carbon capture and storage (CCS), decision makers need to understand the amount of CO2 that can be safely stored in the subsurface and the geographical distribution of storage resources. Estimates of storage resources need to be made using reliable and consistent methods. Previous estimates of CO2 storage potential for a range of countries and regions have been based on a variety of methodologies resulting in a correspondingly wide range of estimates. Consequently, there has been uncertainty about which of the methodologies were most appropriate in given settings, and whether the estimates produced by these methods were useful to policy makers trying to determine the appropriate role of CCS. In 2011, the IEA convened two workshops which brought together experts for six national surveys organisations to review CO2 storage assessment methodologies and make recommendations on how to harmonise CO2 storage estimates worldwide. This report presents the findings of these workshops and an internationally shared guideline for quantifying CO2 storage resources.

Online estimation of internal stack temperatures in solid oxide fuel cell power generating units

NASA Astrophysics Data System (ADS)

Dolenc, B.; Vrečko, D.; Juričić, Ɖ.; Pohjoranta, A.; Pianese, C.

2016-12-01

Thermal stress is one of the main factors affecting the degradation rate of solid oxide fuel cell (SOFC) stacks. In order to mitigate the possibility of fatal thermal stress, stack temperatures and the corresponding thermal gradients need to be continuously controlled during operation. Due to the fact that in future commercial applications the use of temperature sensors embedded within the stack is impractical, the use of estimators appears to be a viable option. In this paper we present an efficient and consistent approach to data-driven design of the estimator for maximum and minimum stack temperatures intended (i) to be of high precision, (ii) to be simple to implement on conventional platforms like programmable logic controllers, and (iii) to maintain reliability in spite of degradation processes. By careful application of subspace identification, supported by physical arguments, we derive a simple estimator structure capable of producing estimates with 3% error irrespective of the evolving stack degradation. The degradation drift is handled without any explicit modelling. The approach is experimentally validated on a 10 kW SOFC system.

Translation, cross-cultural adaptation, and validation of the Bulgarian version of the Liverpool Adverse Event Profile.

PubMed

Kuzmanova, Rumyana; Stefanova, Irina; Velcheva, Irena; Stambolieva, Katerina

2014-10-01

Adverse effects (AEs) of antiepileptic drugs (AEDs) affect the quality of life of patients with epilepsy and their outcomes. There are no questionnaires or studies on the reliability and validity of instruments measuring AEs of AEDs in patients with epilepsy in Bulgarian language. The aim of the present study was the translation, cross-cultural adaptation, and validation of the LAEP in the Bulgarian language in order to use it in the Bulgarian-speaking population in providing a reliable instrument for the clinical monitoring of patients with epilepsy. One hundred thirty-one patients (57 men and 74 women, mean age: 40.13±13.37 years) took part in the investigation. The internal consistency and test-retest reliability were tested by Cronbach's α and ICC estimations. The convergent construct validity was tested by estimating the correlation of the LAEP-BG with the QOLIE-89 and the discriminant validity by evaluating the difference between LAEP-BG scores and clinical parameters such as the type of epilepsy using Kruskal-Wallis ANOVA. The LAEP-BG showed high internal consistency and reliability. The Cronbach's α of the total scale was 0.86. No significant differences between the Cronbach's α coefficients of the total LAEP-BG and original English, Chinese, Spanish, Korean, and Portuguese-Brazilian versions of the questionnaire were observed. The ICCs, which evaluate the test-retest reliability, were higher than the recommended value of 0.75 and determined the strong positive correlations between the first and second examinations. The creation of two subscales "Neurological and psychiatric side effects" and "Non neurological side effects" of the LAEP-BG proposed by us showed good internal consistency (Cronbach's α of 0.85 and 0.71, respectively). The LAEP-BG scores significantly correlated with other questionnaires such as the Quality of Life in Epilepsy Inventory-89 (QOLIE-89) and showed a good discriminative validity between groups with different levels of self-assessed AEs of AEDs. The Bulgarian version of the Liverpool Adverse Event Profile (LAEP) is a reliable and valid tool in assessing the patient-reported AEs of AEDs and their impact on the patient's outcome. Copyright © 2014 Elsevier Inc. All rights reserved.

[New questionnaire to assess self-efficacy toward physical activity in children].

PubMed

Aedo, Angeles; Avila, Héctor

2009-10-01

To design a questionnaire for assessment of self-efficacy toward physical activity in school children, as well as to measure its construct validity, test-retest reliability, and internal consistency. A four-stage multimethod approach was used: (1) bibliographic research followed by exploratory study and the formulation of questions and responses based on a dichotomous scale of 14 items; (2) validation of the content by a panel of experts; (3) application of the preliminary version of the questionnaire to a sample of 900 school-aged children in Mexico City; and (4) determination of the construct validity, test-retest reliability, and internal consistency (Cronbach's alpha). Three factors were identified that explain 64.15% of the variance: the search for positive alternatives to physical activity, ability to deal with possible barriers to exercising, and expectations of skill or competence. The model was validated using the goodness of fit, and the result of 65% less than 0.05 indicated that the estimated factor model fit the data. Cronbach's consistency alpha was 0.733; test-retest reliability was 0.867. The scale designed has adequate reliability and validity. These results are a good indicator of self-efficacy toward physical activity in school children, which is important when developing programs intended to promote such behavior in this age group.

Psychometric Properties of the Obsessive-Compulsive Inventory-Child Version (OCI-CV) in Chilean Children and Adolescents

PubMed Central

Martínez-González, Agustín E.; Rodríguez-Jiménez, Tíscar; Piqueras, José A.; Vera-Villarroel, Pablo; Godoy, Antonio

2015-01-01

In recent years, there has been a considerable increase in the development of assessment tools for obsessive-compulsive symptomatology in children and adolescents. The Obsessive Compulsive Inventory-Child Version (OCI-CV) is a well-established assessment self-report, with special interest for the assessment of dimensions of Obsessive Compulsive Disorder (OCD). This instrument has shown to be useful for clinical and non-clinical populations in two languages (English and European Spanish). Thus, the aim of this study was to analyze the psychometric properties of the OCI-CV in a Chilean community sample. The sample consisted of 816 children and adolescents with a mean age of 14.54 years (SD = 2.21; range = 10–18 years). Factor structure, internal consistency, test-retest reliability, convergent/divergent validity, and gender/age differences were examined. Confirmatory factor analysis showed a 6-factor structure (Doubting/Checking, Obsessing, Hoarding, Washing, Ordering, and Neutralizing) with one second-order factor. Good estimates of reliability (including internal consistency and test-retest), evidence supporting the validity, and small age and gender differences (higher levels of OCD symptomatology among older participants and women, respectively) are found. The OCI-CV is also an adequate scale for the assessment of obsessions and compulsions in a general population of Chilean children and adolescents. PMID:26317404

Validity and Reliability of Malay Version of the Job Content Questionnaire among Public Hospital Female Nurses in Malaysia.

PubMed

Amin, N A; Quek, K F; Oxley, J A; Noah, R M; Nordin, R

2015-10-01

The Job Content Questionnaire (M-JCQ) is an established self-reported instrument used across the world to measure the work dimensions based on the Karasek's demand-control-support model. To evaluate the psychometrics properties of the Malay version of M-JCQ among nurses in Malaysia. This cross-sectional study was carried out on nurses working in 4 public hospitals in Klang Valley area, Malaysia. M-JCQ was used to assess the perceived psychosocial stressors and physical demands of nurses at their workplaces. Construct validity of the questionnaire was examined using exploratory factor analysis (EFA). Cronbach's α values were used to estimate the reliability (internal consistency) of the M-JCQ. EFA showed that 34 selected items were loaded in 4 factors. Except for psychological job demand (Cronbach's α 0.51), the remaining 3 α values for 3 subscales (job control, social support, and physical demand) were greater than 0.70, indicating acceptable internal consistency. However, an item was excluded due to poor item-total correlation (r<0.3). The final M-JCQ was consisted of 33 items. The M-JCQ is a reliable and valid instrument to measure psychosocial and physical stressors in the workplace of public hospital nurses in Malaysia.

Evaluation of the Consumer Assessment of Healthcare Providers and Systems In-Center Hemodialysis Survey

PubMed Central

Paoli, Carly J.; Hays, Ron D.; Taylor-Stokes, Gavin; Piercy, James; Gitlin, Matthew

2014-01-01

Background and objectives The US Centers for Medicare and Medicaid Services (CMS) End Stage Renal Disease Prospective Payment System and Quality Incentive Program requires that dialysis centers meet predefined criteria for quality of patient care to ensure future funding. The CMS selected the Consumer Assessment of Healthcare Providers and Systems In-Center Hemodialysis (CAHPS-ICH) survey for the assessment of patient experience of care. This analysis evaluated the psychometric properties of the CAHPS-ICH survey in a sample of hemodialysis patients. Design, setting, participants, & measurements Data were drawn from the Adelphi CKD Disease Specific Program (a retrospective, cross-sectional survey of nephrologists and patients). Selected United States–based nephrologists treating patients receiving hemodialysis completed patient record forms and provided information on their dialysis center. Patients (n=404) completed the CAHPS-ICH survey (comprising 58 questions) providing six scores for the assessment of patient experience of care. CAHPS-ICH item-scale convergence, discrimination, and reliability were evaluated for multi-item scales. Floor and ceiling effects were estimated for all six scores. Patient (demographics, dialysis history, vascular access method) and facility characteristics (size, ratio of patients-to-physicians, nurses, and technicians) associated with the CAHPS-ICH scores were also evaluated. Results Item-scale correlations and internal consistency reliability estimates provided support for the nephrologists’ communication (range, 0.16–0.71; α=0.81) and quality of care (range, 0.16–0.76; α=0.90) composites. However, the patient information composite had low internal consistency reliability (α=0.55). Provider-to-patient ratios (range, 2.37 for facilities with >36 patients per physician to 2.8 for those with <8 patients per physician) and time spent in the waiting room (3.44 for >15 minutes of waiting time to 3.75 for 5 to <10 minutes) were characteristics most consistently related to patients’ perceptions of dialysis care. Conclusions CAHPS-ICH is a potentially valuable and informative tool for the evaluation of patients’ experiences with dialysis care. Additional studies are needed to estimate clinically meaningful differences between care providers. PMID:24832092

Planck 2013 results. V. LFI calibration

NASA Astrophysics Data System (ADS)

Planck Collaboration; Aghanim, N.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R. C.; Cappellini, B.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Chen, X.; Chiang, L.-Y.; Christensen, P. R.; Church, S.; Colombi, S.; Colombo, L. P. L.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Gaier, T. C.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Hanson, D.; Harrison, D.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Jaffe, A. H.; Jaffe, T. R.; Jewell, J.; Jones, W. C.; Juvela, M.; Kangaslahti, P.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Leach, S.; Leahy, J. P.; Leonardi, R.; Lesgourgues, J.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Naselsky, P.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Novikov, D.; Novikov, I.; O'Dwyer, I. J.; Osborne, S.; Paci, F.; Pagano, L.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, D.; Peel, M.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Ricciardi, S.; Riller, T.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Starck, J.-L.; Stolyarov, V.; Stompor, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Türler, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Varis, J.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Watson, R.; Wilkinson, A.; Yvon, D.; Zacchei, A.; Zonca, A.

2014-11-01

We discuss the methods employed to photometrically calibrate the data acquired by the Low Frequency Instrument on Planck. Our calibration is based on a combination of the orbital dipole plus the solar dipole, caused respectively by the motion of the Planck spacecraft with respect to the Sun and by motion of the solar system with respect to the cosmic microwave background (CMB) rest frame. The latter provides a signal of a few mK with the same spectrum as the CMB anisotropies and is visible throughout the mission. In this data releasewe rely on the characterization of the solar dipole as measured by WMAP. We also present preliminary results (at 44 GHz only) on the study of the Orbital Dipole, which agree with the WMAP value of the solar system speed within our uncertainties. We compute the calibration constant for each radiometer roughly once per hour, in order to keep track of changes in the detectors' gain. Since non-idealities in the optical response of the beams proved to be important, we implemented a fast convolution algorithm which considers the full beam response in estimating the signal generated by the dipole. Moreover, in order to further reduce the impact of residual systematics due to sidelobes, we estimated time variations in the calibration constant of the 30 GHz radiometers (the ones with the largest sidelobes) using the signal of an internal reference load at 4 K instead of the CMB dipole. We have estimated the accuracy of the LFI calibration following two strategies: (1) we have run a set of simulations to assess the impact of statistical errors and systematic effects in the instrument and in the calibration procedure; and (2) we have performed a number of internal consistency checks on the data and on the brightness temperature of Jupiter. Errors in the calibration of this Planck/LFI data release are expected to be about 0.6% at 44 and 70 GHz, and 0.8% at 30 GHz. Both these preliminary results at low and high ℓ are consistent with WMAP results within uncertainties and comparison of power spectra indicates good consistency in the absolute calibration with HFI (0.3%) and a 1.4σ discrepancy with WMAP (0.9%).

Evaluating internal and external markers versus fecal sampling procedure interactions when estimating intake in dairy cows consuming a corn silage-based diet.

PubMed

Velásquez, A V; da Silva, G G; Sousa, D O; Oliveira, C A; Martins, C M M R; Dos Santos, P P M; Balieiro, J C C; Rennó, F P; Fukushima, R S

2018-04-18

Feed intake assessment is a valuable tool for herd management decisions. The use of markers, either internal or external, is currently the most used technique for estimating feed intake in production animals. The experiment used 10 multiparous Holstein cows fed a corn silage-based diet, with 55:45 forage-to-concentrate ratio, the average fecal recovery (FR) of TiO 2 was higher than FR of Cr 2 O 3 , and both FR were more than unity. With internal markers, acetyl bromide lignin and cutin FR were lower than unity, and average FR for indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) was 1.5. The FR was unaffected by the fecal sampling procedure and appears to be an intrinsic property of each molecule and how it interacts with digesta. Of the 2 external markers, only Cr 2 O 3 produced accurate fecal output (FO) estimates and the same happened to dry matter digestibility (DMD) when iNDF and iADF were used. Estimates for DMD and FO were affected by sampling procedure; 72-h bulk [sub-sample from total feces collection (TFC)] sampling consistently produced accurate results. The grab (sub-samples taken at specific times during the day) sampling procedures were accurate when using either of the indigestible fibers (iNDF or iADF) to estimate DMD. However, grab sampling procedures can only be recommended when concomitant TFC is performed on at least one animal per treatment to determine FR. Under these conditions, Cr 2 O 3 is a suitable marker for estimating FO, and iNDF and iADF are adequate for estimating DMD. Moreover, the Cr 2 O 3 +iADF marker pair produces accurate dry matter intake estimates and deserves further attention in ruminant nutrition studies. The method of dosing the external markers is extremely important and greatly affects and determines results. Whichever the method, it must allow the animals to display normal feeding behavior and not affect performance. The grab sampling procedures can replace TFC (once FR is established), which may open new possibilities for pasture-based or collectively housed animals. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Estimation of inlet flow rates for image-based aneurysm CFD models: where and how to begin?

PubMed

Valen-Sendstad, Kristian; Piccinelli, Marina; KrishnankuttyRema, Resmi; Steinman, David A

2015-06-01

Patient-specific flow rates are rarely available for image-based computational fluid dynamics models. Instead, flow rates are often assumed to scale according to the diameters of the arteries of interest. Our goal was to determine how choice of inlet location and scaling law affect such model-based estimation of inflow rates. We focused on 37 internal carotid artery (ICA) aneurysm cases from the Aneurisk cohort. An average ICA flow rate of 245 mL min(-1) was assumed from the literature, and then rescaled for each case according to its inlet diameter squared (assuming a fixed velocity) or cubed (assuming a fixed wall shear stress). Scaling was based on diameters measured at various consistent anatomical locations along the models. Choice of location introduced a modest 17% average uncertainty in model-based flow rate, but within individual cases estimated flow rates could vary by >100 mL min(-1). A square law was found to be more consistent with physiological flow rates than a cube law. Although impact of parent artery truncation on downstream flow patterns is well studied, our study highlights a more insidious and potentially equal impact of truncation site and scaling law on the uncertainty of assumed inlet flow rates and thus, potentially, downstream flow patterns.

26 CFR 1.1502-5 - Estimated tax.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 12 2011-04-01 2011-04-01 false Estimated tax. 1.1502-5 Section 1.1502-5 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Consolidated Tax Liability § 1.1502-5 Estimated tax. (a) General rule—(1...

A comparison of the coupled cluster and internally contracted averaged coupled-pair functional levels of theory for the calculation of the MCH2(+) binding energies for M = Sc to Cu

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Partridge, Harry; Scuseria, Gustavo E.

1992-01-01

The correlation contribution to the M-C binding energy for the MCH2(+) systems can exceed 100 kcal/mol. At the self-consistent field (SCF) level, these systems can be more than 50 kcal/mol above the fragment energies. In spite of the poor zeroth-order reference, the coupled cluster single and double excitation method with a perturbational estimate of triple excitations, CCSD(T), method is shown to provide an accurate description of these systems. The maximum difference between the CCSD(T) and internally contracted averaged coupled-pair functional binding energies is 1.5 kcal/mol for CrCH2(+), with the remaining systems agreeing to within 1.0 kcal/mol.

The pricing behavior comparison of Canada and Australia exporter in wheat international market using Pricing to Market (PTM) and Residual Demand Elasticity (RDE)

NASA Astrophysics Data System (ADS)

Wibowo, R. P.; Sumono; Iddrisu, Y.; Darus, M.; Sihombing, L. P.; Jufri

2018-02-01

This paper try to identify and examined the degree of market power on wheat international market by 2 major exporting countries comprising Canada and Australia by using the Pricing to Market (PTM) method and Residual Demand Elasticity (RDE) method. The PTM method found that Canada impose noncompetitive strategy by applying price discrimination and apply market power to their importing. Different results come from Australian exporter as they are not using their market power to the importing. Conflicting result arise from estimation using RDE and PTM method suggest that the need to extend the theoretical model of both model by expand its economic and econometric model to have consistent expected result theoretically and empirically.

Underwater robot society doing internal inspection and leak monitoring of water systems

NASA Astrophysics Data System (ADS)

Halme, Aarne; Vainio, Mika; Appelqvist, Pekka; Jakubik, Peter; Schonberg, Torsten; Visala, Arto

1997-09-01

In the field of civil engineering an effective internal monitoring of pipes and water storage is very problematic. Normally the sensors used for the task are either fixed or manually movable. Thus they will only provide locally and temporally restricted information. As a solution an underwater robotic sensor/actuator society is presented. The system is capable of operating inside a fluid environment as a kind of distributed sensory system. The value of the system emerges from the interactions between the members. Through a communication system the society fuses information from individual members and provides a more reliable estimate of the conditions inside water systems. Tests results in a transparent demo process consisting of tanks and pipes with a volume of 700 liters are presented.

Space Station Furnace Facility. Volume 3: Program cost estimate

NASA Technical Reports Server (NTRS)

1992-01-01

The approach used to estimate costs for the Space Station Furnace Facility (SSFF) is based on a computer program developed internally at Teledyne Brown Engineering (TBE). The program produces time-phased estimates of cost elements for each hardware component, based on experience with similar components. Engineering estimates of the degree of similarity or difference between the current project and the historical data is then used to adjust the computer-produced cost estimate and to fit it to the current project Work Breakdown Structure (WBS). The SSFF Concept as presented at the Requirements Definition Review (RDR) was used as the base configuration for the cost estimate. This program incorporates data on costs of previous projects and the allocation of those costs to the components of one of three, time-phased, generic WBS's. Input consists of a list of similar components for which cost data exist, number of interfaces with their type and complexity, identification of the extent to which previous designs are applicable, and programmatic data concerning schedules and miscellaneous data (travel, off-site assignments). Output is program cost in labor hours and material dollars, for each component, broken down by generic WBS task and program schedule phase.

Evaluation and Application of Satellite-Based Latent Heating Profile Estimation Methods

NASA Technical Reports Server (NTRS)

Olson, William S.; Grecu, Mircea; Yang, Song; Tao, Wei-Kuo

2004-01-01

In recent years, methods for estimating atmospheric latent heating vertical structure from both passive and active microwave remote sensing have matured to the point where quantitative evaluation of these methods is the next logical step. Two approaches for heating algorithm evaluation are proposed: First, application of heating algorithms to synthetic data, based upon cloud-resolving model simulations, can be used to test the internal consistency of heating estimates in the absence of systematic errors in physical assumptions. Second, comparisons of satellite-retrieved vertical heating structures to independent ground-based estimates, such as rawinsonde-derived analyses of heating, provide an additional test. The two approaches are complementary, since systematic errors in heating indicated by the second approach may be confirmed by the first. A passive microwave and combined passive/active microwave heating retrieval algorithm are evaluated using the described approaches. In general, the passive microwave algorithm heating profile estimates are subject to biases due to the limited vertical heating structure information contained in the passive microwave observations. These biases may be partly overcome by including more environment-specific a priori information into the algorithm s database of candidate solution profiles. The combined passive/active microwave algorithm utilizes the much higher-resolution vertical structure information provided by spaceborne radar data to produce less biased estimates; however, the global spatio-temporal sampling by spaceborne radar is limited. In the present study, the passive/active microwave algorithm is used to construct a more physically-consistent and environment-specific set of candidate solution profiles for the passive microwave algorithm and to help evaluate errors in the passive algorithm s heating estimates. Although satellite estimates of latent heating are based upon instantaneous, footprint- scale data, suppression of random errors requires averaging to at least half-degree resolution. Analysis of mesoscale and larger space-time scale phenomena based upon passive and passive/active microwave heating estimates from TRMM, SSMI, and AMSR data will be presented at the conference.

Current profile redistribution driven by neutral beam injection in a reversed-field pinch

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

Parke, E.; Department of Physics, University of Wisconsin-Madison 1150 University Ave., Madison, Wisconsin 53706; Anderson, J. K.

2016-05-15

Neutral beam injection in reversed-field pinch (RFP) plasmas on the Madison Symmetric Torus [Dexter et al., Fusion Sci. Technol. 19, 131 (1991)] drives current redistribution with increased on-axis current density but negligible net current drive. Internal fluctuations correlated with tearing modes are observed on multiple diagnostics; the behavior of tearing mode correlated structures is consistent with flattening of the safety factor profile. The first application of a parametrized model for island flattening to temperature fluctuations in an RFP allows inferrence of rational surface locations for multiple tearing modes. The m = 1, n = 6 mode is observed to shift inward by 1.1 ± 0.6 cm withmore » neutral beam injection. Tearing mode rational surface measurements provide a strong constraint for equilibrium reconstruction, with an estimated reduction of q{sub 0} by 5% and an increase in on-axis current density of 8% ± 5%. The inferred on-axis current drive is consistent with estimates of fast ion density using TRANSP [Goldston et al., J. Comput. Phys. 43, 61 (1981)].« less

Psychometric properties of the Plutchik´s Violence Risk Scale on adolescent sample of Spanish-speaking population.

PubMed

Alcázar-Córcoles, Miguel Á; Verdejo-García, Antonio; Bouso-Sáiz, José C

2016-01-01

The objective of the present study was the validation and scaling of the Plutchik's Violence Risk Scale (EV) in adolescent Spanish-speaking population. For this purpose, a sample of adolescents from El Salvador, Mexico and Spain was obtained. The sample consisted of 1035 participants with a mean age of 16.2. There were 450 adolescents from forensic population (those who committed crime) and 585 adolescents from normal population (no crime committed). The internal consistency of the EV was estimated by Cronbach's alpha coefficient and with a value of 0.782. As for validity, the factorial structures found explain a large proportion of the variance (53.385%); the convergent validity was estimated by the correlation between the dimensions found, the EV and sociodemographic, criminological and personality variables. The developed scales are presented, for the first time in a cross-cultural sample, differentiating between gender and continent. Consequently, the obtained results suggest that the EV is a valid and reliable instrument within adolescent Spanish-speaking population. Furthermore, it is a quick scale, easy to apply, which is something valuable in forensic assessment.

Clinimetric Testing of the Comprehensive Cervical Dystonia Rating Scale

PubMed Central

Comella, C. L.; Perlmutter, J.S.; Jinnah, H. A.; Waliczek, T. A.; Rosen, A. R.; Galpern, W. R.; Adler, C. H.; Barbano, R. L.; Factor, S. A.; Goetz, C.G.; Jankovic, J.; Reich, S. G.; Rodriguez, R. L.; Severt, W. L.; Zurowski, M.; Fox, S. H.; Stebbins, G.T.

2016-01-01

Objective To test the clinimetric properties of the Comprehensive Cervical Dystonia Rating Scale. Background This is a modular scale with modifications of the Toronto Western Spasmodic Torticollis Rating Scale (composed of three subscales assessing motor severity, disability and pain) now referred to as the revised Toronto Western Spasmodic Torticollis Scale-2.; a newly developed psychiatric screening instrument; and the Cervical Dystonia Impact Profile-58 as a quality of life measure. Methods Ten dystonia experts rated subjects with cervical dystonia using the comprehensive scale. Clinimetric techniques assessed each module of the scale for reliability, item correlation and factor structure. Results There were 208 cervical dystonia patients (73% women, age 59±10 years, duration 15±12 years). The internal consistency of the motor severity subscale was acceptable (Cronbach’s alpha = 0.57). Item to total correlations showed that elimination of items with low correlations (<0.20) increased alpha to 0.71. Internal consistency estimates for the subscales for disability and pain were 0.88 and 0.95 respectively. The psychiatric screening scale had a Cronbach’s alpha of 0.84 and satisfactory item to total correlations. When the subscales of the Toronto Western Spasmodic Torticollis scale -2 were combined with the psychiatric screening scale, Cronbach's alpha was 0.88, and construct validity assessment demonstrated four rational factors: motor, disability, pain and psychiatric disorders. The Cervical Dystonia Impact Profile-58 had an alpha of 0.98 and its construction was validated through a confirmatory factor analysis. Conclusions The modules of the Comprehensive Cervical Dystonia Rating Scale are internally consistent with a logical factor structure. PMID:26971359

Training and Maintaining System-Wide Reliability in Outcome Management.

PubMed

Barwick, Melanie A; Urajnik, Diana J; Moore, Julia E

2014-01-01

The Child and Adolescent Functional Assessment Scale (CAFAS) is widely used for outcome management, for providing real time client and program level data, and the monitoring of evidence-based practices. Methods of reliability training and the assessment of rater drift are critical for service decision-making within organizations and systems of care. We assessed two approaches for CAFAS training: external technical assistance and internal technical assistance. To this end, we sampled 315 practitioners trained by external technical assistance approach from 2,344 Ontario practitioners who had achieved reliability on the CAFAS. To assess the internal technical assistance approach as a reliable alternative training method, 140 practitioners trained internally were selected from the same pool of certified raters. Reliabilities were high for both practitioners trained by external technical assistance and internal technical assistance approaches (.909-.995, .915-.997, respectively). 1 and 3-year estimates showed some drift on several scales. High and consistent reliabilities over time and training method has implications for CAFAS training of behavioral health care practitioners, and the maintenance of CAFAS as a global outcome management tool in systems of care.

Temporal coherence of the acoustic field forward propagated through a continental shelf with random internal waves.

PubMed

Gong, Zheng; Chen, Tianrun; Ratilal, Purnima; Makris, Nicholas C

2013-11-01

An analytical model derived from normal mode theory for the accumulated effects of range-dependent multiple forward scattering is applied to estimate the temporal coherence of the acoustic field forward propagated through a continental-shelf waveguide containing random three-dimensional internal waves. The modeled coherence time scale of narrow band low-frequency acoustic field fluctuations after propagating through a continental-shelf waveguide is shown to decay with a power-law of range to the -1/2 beyond roughly 1 km, decrease with increasing internal wave energy, to be consistent with measured acoustic coherence time scales. The model should provide a useful prediction of the acoustic coherence time scale as a function of internal wave energy in continental-shelf environments. The acoustic coherence time scale is an important parameter in remote sensing applications because it determines (i) the time window within which standard coherent processing such as matched filtering may be conducted, and (ii) the number of statistically independent fluctuations in a given measurement period that determines the variance reduction possible by stationary averaging.

Analysis of the Internal Consistency of Three Autism Scales. Brief Report.

ERIC Educational Resources Information Center

Sturmey, Peter; And Others

1992-01-01

Analyses of the internal consistency of three autism scales--the Autism Behavior Checklist (ABC), the Real Life Rating Scale (RLRS), and the Childhood Autism Rating Scale (CARS)--were conducted with 34 children with pervasive developmental disabilities. Good internal consistency was found for the CARS. Adequate full-scale consistency was found for…

X-Ray Transition Energies Database

National Institute of Standards and Technology Data Gateway

SRD 128 NIST X-Ray Transition Energies Database (Web, free access)   This X-ray transition table provides the energies and wavelengths for the K and L transitions connecting energy levels having principal quantum numbers n = 1, 2, 3, and 4. The elements covered include Z = 10, neon to Z = 100, fermium. There are two unique features of this data base: (1) a serious attempt to have all experimental values on a scale consistent with the International System of measurement (the SI) and (2) inclusion of accurate theoretical estimates for all transitions.

A new multidimensional measure of African adolescents' perceptions of teachers' behaviors.

PubMed

Mboya, M M

1994-04-01

The Perceived Teacher Behavior Inventory was designed to measure three dimensions of students' perceptions of the behaviors of their teachers. This research was conducted to assess the statistical validity and reliability of the instrument administered to 770 students attending two coeducational high schools in Cape Town, South Africa. Factor analysis clearly identified three subscales indicating that the instrument distinguished the students' perceptions of their teachers' behaviors in three areas. Estimates of internal consistency of the subscales were assessed using the squared multiple correlation as the index of reliability.

Internal radiocesium contamination of adults and children in Fukushima 7 to 20 months after the Fukushima NPP accident as measured by extensive whole-body-counter surveys

PubMed Central

HAYANO, Ryugo S.; TSUBOKURA, Masaharu; MIYAZAKI, Makoto; SATOU, Hideo; SATO, Katsumi; MASAKI, Shin; SAKUMA, Yu

2013-01-01

The Fukushima Dai-ichi NPP accident contaminated the soil of densely-populated regions in Fukushima Prefecture with radioactive cesium, which poses significant risks of internal and external exposure to the residents. If we apply the knowledge of post-Chernobyl accident studies, internal exposures in excess of a few mSv/y would be expected to be frequent in Fukushima. Extensive whole-body-counter surveys (n = 32,811) carried out at the Hirata Central Hospital between October, 2011 and November, 2012, however show that the internal exposure levels of residents are much lower than estimated. In particular, the first sampling-bias-free assessment of the internal exposure of children in the town of Miharu, Fukushima, shows that the 137Cs body burdens of all children (n = 1,383, ages 6–15, covering 95% of children enrolled in town-operated schools) were below the detection limit of 300 Bq/body in the fall of 2012. These results are not conclusive for the prefecture as a whole, but are consistent with results obtained from other municipalities in the prefecture, and with prefectural data. PMID:23574806

[KON-2006--Neurotic Personality Questionnaire].

PubMed

Aleksandrowicz, Jerzy W; Klasa, Katarzyna; Sobański, Jerzy A; Stolarska, Dorota

2007-01-01

Construction of a questionnaire describing personality traits connected to the occurrence and persistence of neurotic disorders. Responses of 794 patients (before treatment) and 520 persons from the control group on items of the constructed personality questionnaire and the symptom checklist "0". Analyses of subscales reliability and item-scale correlations, test-retest and split-half reliability. Factor analyses estimating internal reliability of the questionnaire. Cross-validation with the KO"0". symptom checklist Psychometric properties of KON-2006 questionnaire indicate that it is consistent and reliable enough. Validity analyses indicate a large probability that the X-KON coefficient informs on personality dysfunctions related to neurotic disorders. The Neurotic Personality Questionnaire KON-2006 may serve to estimate personality traits connected to the occurrence and persistence of neurotic disorders as well as changes resulting from psychotherapy.

Statistical approaches to lifetime measurements with restricted observation times

NASA Astrophysics Data System (ADS)

Chen, X. C.; Zeng, Q.; Litvinov, Yu. A.; Tu, X. L.; Walker, P. M.; Wang, M.; Wang, Q.; Yue, K.; Zhang, Y. H.

2017-09-01

Two generic methods based on frequentism and Bayesianism are presented in this work aiming to adequately estimate decay lifetimes from measured data, while accounting for restricted observation times in the measurements. All the experimental scenarios that can possibly arise from the observation constraints are treated systematically and formulas are derived. The methods are then tested against the decay data of bare isomeric 44+94mRu, which were measured using isochronous mass spectrometry with a timing detector at the CSRe in Lanzhou, China. Applying both methods in three distinct scenarios yields six different but consistent lifetime estimates. The deduced values are all in good agreement with a prediction based on the neutral-atom value modified to take the absence of internal conversion into account. Potential applications of such methods are discussed.

Discriminating External and Internal Causes for Heading Changes in Freely Flying Drosophila

PubMed Central

Sayaman, Rosalyn W.; Murray, Richard M.; Dickinson, Michael H.

2013-01-01

As animals move through the world in search of resources, they change course in reaction to both external sensory cues and internally-generated programs. Elucidating the functional logic of complex search algorithms is challenging because the observable actions of the animal cannot be unambiguously assigned to externally- or internally-triggered events. We present a technique that addresses this challenge by assessing quantitatively the contribution of external stimuli and internal processes. We apply this technique to the analysis of rapid turns (“saccades”) of freely flying Drosophila melanogaster. We show that a single scalar feature computed from the visual stimulus experienced by the animal is sufficient to explain a majority (93%) of the turning decisions. We automatically estimate this scalar value from the observable trajectory, without any assumption regarding the sensory processing. A posteriori, we show that the estimated feature field is consistent with previous results measured in other experimental conditions. The remaining turning decisions, not explained by this feature of the visual input, may be attributed to a combination of deterministic processes based on unobservable internal states and purely stochastic behavior. We cannot distinguish these contributions using external observations alone, but we are able to provide a quantitative bound of their relative importance with respect to stimulus-triggered decisions. Our results suggest that comparatively few saccades in free-flying conditions are a result of an intrinsic spontaneous process, contrary to previous suggestions. We discuss how this technique could be generalized for use in other systems and employed as a tool for classifying effects into sensory, decision, and motor categories when used to analyze data from genetic behavioral screens. PMID:23468601

The Swedish translation and cross-cultural adaptation of the Functional Assessment of Chronic Illness Therapy - Cervical Dysplasia (FACIT-CD): linguistic validity and reliability of the Swedish version.

PubMed

Rask, Marie; Oscarsson, Marie; Ludwig, Neil; Swahnberg, Katarina

2017-04-04

Cervical dysplasia is a precancerous condition, which has been shown to create anxiety in women. To be able to investigate these women's health-related quality of life, a disease-specific instrument is required. There does not seem to be a Swedish version of an instrument to screen for this specific disease. Therefore, this study aims to translate and cross-culturally adapt the Functional Assessment of Chronic Illness Therapy - Cervical Dysplasia (FACIT-CD) into a Swedish context and evaluate its linguistic validity and reliability. The Functional Assessment of Chronic Illness Therapy (FACIT) translation methodology was used, which consists of several steps including pilot testing of the FACIT-CD instrument through cognitive debriefing interviews. Ten women diagnosed with cervical dysplasia participated in the cognitive debriefing interviews. The internal consistency reliability of the Swedish FACIT-CD was estimated by Cronbach's alpha coefficient. Homogeneity of the items was evaluated by corrected item-total correlations. The sample consists of 34 women who were diagnosed with cervical dysplasia. The translation and cross-cultural adaptation went smoothly without any problems for the majority of the items. The cognitive debriefing interviews indicated that the Swedish FACIT-CD consists of relevant items, is easy to understand and complete, and has unambiguous and comprehensive response categories. The translation and cross-cultural adaptation resulted in a Swedish FACIT-CD, which is conceptually and semantically equivalent to the English version and linguistically valid. The total scale of the Swedish FACIT-CD exhibited good internal consistency reliability with a Cronbach's alpha coefficient of 0.84, and all of the subscales exhibited acceptable value between 0.71 and 0.81 except the Relationships subscale, which had a value of 0.67. Finally, all but four items exceeded the acceptable level for the corrected item-total correlations of ≥ 0.20. The Swedish FACIT-CD is conceptually and semantically equivalent to the English version and linguistically valid; further, it exhibits good internal consistency reliability.

Adding source positions to the IVS Combination

NASA Astrophysics Data System (ADS)

Bachmann, S.; Thaller, D.

2016-12-01

Simultaneous estimation of source positions, Earth orientation parameters (EOPs) and station positions in one common adjustment is crucial for a consistent generation of celestial and terrestrial reference frame (CRF and TRF, respectively). VLBI is the only technique to guarantee this consistency. Previous publications showed that the VLBI intra-technique combination could improve the quality of the EOPs and station coordinates compared to the individual contributions. By now, the combination of EOP and station coordinates is well established within the IVS and in combination with other space geodetic techniques (e.g. inter-technique combined TRF like the ITRF). Most of the contributing IVS Analysis Centers (AC) now provide source positions as a third parameter type (besides EOP and station coordinates), which have not been used for an operational combined solution yet. A strategy for the combination of source positions has been developed and integrated into the routine IVS combination. Investigations are carried out to compare the source positions derived from different IVS ACs with the combined estimates to verify whether the source positions are improved by the combination, as it has been proven for EOP and station coordinates. Furthermore, global solutions of source positions, i.e., so-called catalogues describing a CRF, are generated consistently with the TRF similar to the IVS operational combined quarterly solution. The combined solutions of the source positions time series and the consistently generated TRF and CRF are compared internally to the individual solutions of the ACs as well as to external CRF catalogues and TRFs. Additionally, comparisons of EOPs based on different CRF solutions are presented as an outlook for consistent EOP, CRF and TRF realizations.

The measurement of disability weights for 18 prevalent acute poisoning conditions.

PubMed

Asadi, R; Afshari, R; Dadpour, B

2016-10-01

Disability weights (DWs) are used in disease burden studies, with the calculation of the weight of the disability as years lived with disability versus years of lost life accounting for mortalities. Currently, there is a single DW score available for poisoning, which is considered to be a single health state. This makes it difficult to evaluate the differing burdens of poisonings involving various substances/conditions in comparison with other health states in countries with different patterns of substance abuse. The aim of this study is therefore to estimate the DWs of 18 common poisonings based on the expert elicitation method. A panel of 10 medical clinicians who were familiar with the clinical aspects of different poisonings estimated the DWs of 50 health states by interpolating them on a calibrated Visual Analogue Scale. The DWs of some poisonings, such as alcohol, cannabis and heroin, had been estimated in previous studies and so were used to determine the external consistency of our panel. As a matter of routine, the DWs could vary on a scale between 0 (best health state) and 1 (worst health state). Statistical analysis showed that both the internal (Cronbach's α = 0.912) and external consistency of the panel were acceptable. The DWs for the different poisonings were estimated along a range from 0.830 for severe aluminium phosphide to 0.022 for mild benzodiazepine. Different poisonings should be weighted differently since they vary widely. Unfortunately, they are currently all weighted the same. © The Author(s) 2015.

The curious case of Mercury's internal structure

NASA Astrophysics Data System (ADS)

Hauck, Steven A.; Margot, Jean-Luc; Solomon, Sean C.; Phillips, Roger J.; Johnson, Catherine L.; Lemoine, Frank G.; Mazarico, Erwan; McCoy, Timothy J.; Padovan, Sebastiano; Peale, Stanton J.; Perry, Mark E.; Smith, David E.; Zuber, Maria T.

2013-06-01

The recent determination of the gravity field of Mercury and new Earth-based radar observations of the planet's spin state afford the opportunity to explore Mercury's internal structure. These observations provide estimates of two measures of the radial mass distribution of Mercury: the normalized polar moment of inertia and the fractional polar moment of inertia of the solid portion of the planet overlying the liquid core. Employing Monte Carlo techniques, we calculate several million models of the radial density structure of Mercury consistent with its radius and bulk density and constrained by these moment of inertia parameters. We estimate that the top of the liquid core is at a radius of 2020 ± 30 km, the mean density above this boundary is 3380 ± 200 kg m-3, and the density below the boundary is 6980 ± 280 kg m-3. We find that these internal structure parameters are robust across a broad range of compositional models for the core and planet as a whole. Geochemical observations of Mercury's surface by MESSENGER indicate a chemically reducing environment that would favor the partitioning of silicon or both silicon and sulfur into the metallic core during core-mantle differentiation. For a core composed of Fe-S-Si materials, the thermodynamic properties at elevated pressures and temperatures suggest that an FeS-rich layer could form at the top of the core and that a portion of it may be presently solid.

Overcoming the Problems of Inconsistent International Migration data: A New Method Applied to Flows in Europe

PubMed Central

Raymer, James; van der Erf, Rob; van Wissen, Leo

2010-01-01

Due to differences in definitions and measurement methods, cross-country comparisons of international migration patterns are difficult and confusing. Emigration numbers reported by sending countries tend to differ from the corresponding immigration numbers reported by receiving countries. In this paper, a methodology is presented to achieve harmonised estimates of migration flows benchmarked to a specific definition of duration. This methodology accounts for both differences in definitions and the effects of measurement error due to, for example, under reporting and sampling fluctuations. More specifically, the differences between the two sets of reported data are overcome by estimating a set of adjustment factors for each country’s immigration and emigration data. The adjusted data take into account any special cases where the origin–destination patterns do not match the overall patterns. The new method for harmonising migration flows that we present is based on earlier efforts by Poulain (European Journal of Population, 9(4): 353–381 1993, Working Paper 12, joint ECE-Eurostat Work Session on Migration Statistics, Geneva, Switzerland 1999) and is illustrated for movements between 19 European countries from 2002 to 2007. The results represent a reliable and consistent set of international migration flows that can be used for understanding recent changes in migration patterns, as inputs into population projections and for developing evidence-based migration policies. PMID:21124647

Overcoming the Problems of Inconsistent International Migration data: A New Method Applied to Flows in Europe.

PubMed

de Beer, Joop; Raymer, James; van der Erf, Rob; van Wissen, Leo

2010-11-01

Due to differences in definitions and measurement methods, cross-country comparisons of international migration patterns are difficult and confusing. Emigration numbers reported by sending countries tend to differ from the corresponding immigration numbers reported by receiving countries. In this paper, a methodology is presented to achieve harmonised estimates of migration flows benchmarked to a specific definition of duration. This methodology accounts for both differences in definitions and the effects of measurement error due to, for example, under reporting and sampling fluctuations. More specifically, the differences between the two sets of reported data are overcome by estimating a set of adjustment factors for each country's immigration and emigration data. The adjusted data take into account any special cases where the origin-destination patterns do not match the overall patterns. The new method for harmonising migration flows that we present is based on earlier efforts by Poulain (European Journal of Population, 9(4): 353-381 1993, Working Paper 12, joint ECE-Eurostat Work Session on Migration Statistics, Geneva, Switzerland 1999) and is illustrated for movements between 19 European countries from 2002 to 2007. The results represent a reliable and consistent set of international migration flows that can be used for understanding recent changes in migration patterns, as inputs into population projections and for developing evidence-based migration policies.

Will international emissions trading help achieve the objectives of the Paris Agreement?

NASA Astrophysics Data System (ADS)

Fujimori, Shinichiro; Kubota, Izumi; Dai, Hancheng; Takahashi, Kiyoshi; Hasegawa, Tomoko; Liu, Jing-Yu; Hijioka, Yasuaki; Masui, Toshihiko; Takimi, Maho

2016-10-01

Under the Paris Agreement, parties set and implement their own emissions targets as nationally determined contributions (NDCs) to tackle climate change. International carbon emissions trading is expected to reduce global mitigation costs. Here, we show the benefit of emissions trading under both NDCs and a more ambitious reduction scenario consistent with the 2 °C goal. The results show that the global welfare loss, which was measured based on estimated household consumption change in 2030, decreased by 75% (from 0.47% to 0.16%), as a consequence of achieving NDCs through emissions trading. Furthermore, achieving the 2 °C targets without emissions trading led to a global welfare loss of 1.4%-3.4%, depending on the burden-sharing scheme used, whereas emissions trading reduced the loss to around 1.5% (from 1.4% to 1.7%). These results indicate that emissions trading is a valuable option for the international system, enabling NDCs and more ambitious targets to be achieved in a cost-effective manner.

Validity and feasibility of a satellite imagery-based method for rapid estimation of displaced populations

PubMed Central

2013-01-01

Background Estimating the size of forcibly displaced populations is key to documenting their plight and allocating sufficient resources to their assistance, but is often not done, particularly during the acute phase of displacement, due to methodological challenges and inaccessibility. In this study, we explored the potential use of very high resolution satellite imagery to remotely estimate forcibly displaced populations. Methods Our method consisted of multiplying (i) manual counts of assumed residential structures on a satellite image and (ii) estimates of the mean number of people per structure (structure occupancy) obtained from publicly available reports. We computed population estimates for 11 sites in Bangladesh, Chad, Democratic Republic of Congo, Ethiopia, Haiti, Kenya and Mozambique (six refugee camps, three internally displaced persons’ camps and two urban neighbourhoods with a mixture of residents and displaced) ranging in population from 1,969 to 90,547, and compared these to “gold standard” reference population figures from census or other robust methods. Results Structure counts by independent analysts were reasonably consistent. Between one and 11 occupancy reports were available per site and most of these reported people per household rather than per structure. The imagery-based method had a precision relative to reference population figures of <10% in four sites and 10–30% in three sites, but severely over-estimated the population in an Ethiopian camp with implausible occupancy data and two post-earthquake Haiti sites featuring dense and complex residential layout. For each site, estimates were produced in 2–5 working person-days. Conclusions In settings with clearly distinguishable individual structures, the remote, imagery-based method had reasonable accuracy for the purposes of rapid estimation, was simple and quick to implement, and would likely perform better in more current application. However, it may have insurmountable limitations in settings featuring connected buildings or shelters, a complex pattern of roofs and multi-level buildings. Based on these results, we discuss possible ways forward for the method’s development. PMID:23343099

Validity and feasibility of a satellite imagery-based method for rapid estimation of displaced populations.

PubMed

Checchi, Francesco; Stewart, Barclay T; Palmer, Jennifer J; Grundy, Chris

2013-01-23

Estimating the size of forcibly displaced populations is key to documenting their plight and allocating sufficient resources to their assistance, but is often not done, particularly during the acute phase of displacement, due to methodological challenges and inaccessibility. In this study, we explored the potential use of very high resolution satellite imagery to remotely estimate forcibly displaced populations. Our method consisted of multiplying (i) manual counts of assumed residential structures on a satellite image and (ii) estimates of the mean number of people per structure (structure occupancy) obtained from publicly available reports. We computed population estimates for 11 sites in Bangladesh, Chad, Democratic Republic of Congo, Ethiopia, Haiti, Kenya and Mozambique (six refugee camps, three internally displaced persons' camps and two urban neighbourhoods with a mixture of residents and displaced) ranging in population from 1,969 to 90,547, and compared these to "gold standard" reference population figures from census or other robust methods. Structure counts by independent analysts were reasonably consistent. Between one and 11 occupancy reports were available per site and most of these reported people per household rather than per structure. The imagery-based method had a precision relative to reference population figures of <10% in four sites and 10-30% in three sites, but severely over-estimated the population in an Ethiopian camp with implausible occupancy data and two post-earthquake Haiti sites featuring dense and complex residential layout. For each site, estimates were produced in 2-5 working person-days. In settings with clearly distinguishable individual structures, the remote, imagery-based method had reasonable accuracy for the purposes of rapid estimation, was simple and quick to implement, and would likely perform better in more current application. However, it may have insurmountable limitations in settings featuring connected buildings or shelters, a complex pattern of roofs and multi-level buildings. Based on these results, we discuss possible ways forward for the method's development.

Vascular input function correction of inflow enhancement for improved pharmacokinetic modeling of liver DCE-MRI.

PubMed

Ning, Jia; Schubert, Tilman; Johnson, Kevin M; Roldán-Alzate, Alejandro; Chen, Huijun; Yuan, Chun; Reeder, Scott B

2018-06-01

To propose a simple method to correct vascular input function (VIF) due to inflow effects and to test whether the proposed method can provide more accurate VIFs for improved pharmacokinetic modeling. A spoiled gradient echo sequence-based inflow quantification and contrast agent concentration correction method was proposed. Simulations were conducted to illustrate improvement in the accuracy of VIF estimation and pharmacokinetic fitting. Animal studies with dynamic contrast-enhanced MR scans were conducted before, 1 week after, and 2 weeks after portal vein embolization (PVE) was performed in the left portal circulation of pigs. The proposed method was applied to correct the VIFs for model fitting. Pharmacokinetic parameters fitted using corrected and uncorrected VIFs were compared between different lobes and visits. Simulation results demonstrated that the proposed method can improve accuracy of VIF estimation and pharmacokinetic fitting. In animal study results, pharmacokinetic fitting using corrected VIFs demonstrated changes in perfusion consistent with changes expected after PVE, whereas the perfusion estimates derived by uncorrected VIFs showed no significant changes. The proposed correction method improves accuracy of VIFs and therefore provides more precise pharmacokinetic fitting. This method may be promising in improving the reliability of perfusion quantification. Magn Reson Med 79:3093-3102, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

A model describing diffusion in prostate cancer.

PubMed

Gilani, Nima; Malcolm, Paul; Johnson, Glyn

2017-07-01

Quantitative diffusion MRI has frequently been studied as a means of grading prostate cancer. Interpretation of results is complicated by the nature of prostate tissue, which consists of four distinct compartments: vascular, ductal lumen, epithelium, and stroma. Current diffusion measurements are an ill-defined weighted average of these compartments. In this study, prostate diffusion is analyzed in terms of a model that takes explicit account of tissue compartmentalization, exchange effects, and the non-Gaussian behavior of tissue diffusion. The model assumes that exchange between the cellular (ie, stromal plus epithelial) and the vascular and ductal compartments is slow. Ductal and cellular diffusion characteristics are estimated by Monte Carlo simulation and a two-compartment exchange model, respectively. Vascular pseudodiffusion is represented by an additional signal at b = 0. Most model parameters are obtained either from published data or by comparing model predictions with the published results from 41 studies. Model prediction error is estimated using 10-fold cross-validation. Agreement between model predictions and published results is good. The model satisfactorily explains the variability of ADC estimates found in the literature. A reliable model that predicts the diffusion behavior of benign and cancerous prostate tissue of different Gleason scores has been developed. Magn Reson Med 78:316-326, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Quantifying annual internal effective 137Cesium dose utilizing direct body-burden measurement and ecological dose modeling.

PubMed

Jelin, Benjamin A; Sun, Wenjie; Kravets, Alexandra; Naboka, Maryna; Stepanova, Eugenia I; Vdovenko, Vitaliy Y; Karmaus, Wilfried J; Lichosherstov, Alex; Svendsen, Erik R

2016-11-01

The Chernobyl Nuclear Power Plant (CNPP) accident represents one of the most significant civilian releases of 137 Cesium ( 137 Cs, radiocesium) in human history. In the Chernobyl-affected region, radiocesium is considered to be the greatest on-going environmental hazard to human health by radiobiologists and public health scientists. The goal of this study was to characterize dosimetric patterns and predictive factors for whole-body count (WBC)-derived radiocesium internal dose estimations in a CNPP-affected children's cohort, and cross-validate these estimations with a soil-based ecological dose estimation model. WBC data were used to estimate the internal effective dose using the International Commission on Radiological Protection (ICRP) 67 dose conversion coefficient for 137 Cs and MONDAL Version 3.01 software. Geometric mean dose estimates from each model were compared utilizing paired t-tests and intra-class correlation coefficients. Additionally, we developed predictive models for WBC-derived dose estimation in order to determine the appropriateness of EMARC to estimate dose for this population. The two WBC-derived dose predictive models identified 137 Cs soil concentration (P<0.0001) as the strongest predictor of annual internal effective dose from radiocesium validating the use of the soil-based EMARC model. The geometric mean internal effective dose estimate of the EMARC model (0.183 mSv/y) was the highest followed by the ICRP 67 dose estimates (0.165 mSv/y) and the MONDAL model estimates (0.149 mSv/y). All three models yielded significantly different geometric mean dose (P<0.05) estimates for this cohort when stratified by sex, age at time of exam and season of exam, except for the mean MONDAL and EMARC estimates for 15- and 16-year olds and mean ICRP and MONDAL estimates for children examined in Winter. Further prospective and retrospective radio-epidemiological studies utilizing refined WBC measurements and ecological model dose estimations, in conjunction with findings from animal toxicological studies, should help elucidate possible deterministic radiogenic health effects associated with chronic low-dose internal exposure to 137 Cs.

A Systematic Review of the Frequency of Neurocyticercosis with a Focus on People with Epilepsy

PubMed Central

Ndimubanzi, Patrick C.; Carabin, Hélène; Budke, Christine M.; Nguyen, Hai; Qian, Ying-Jun; Rainwater, Elizabeth; Dickey, Mary; Reynolds, Stephanie; Stoner, Julie A.

2010-01-01

Background The objective of this study is to conduct a systematic review of studies reporting the frequency of neurocysticercosis (NCC) worldwide. Methods/Principal Findings PubMed, Commonwealth Agricultural Bureau (CAB) abstracts and 23 international databases were systematically searched for articles published from January 1, 1990 to June 1, 2008. Articles were evaluated for inclusion by at least two researchers focusing on study design and methods. Data were extracted independently using standardized forms. A random-effects binomial model was used to estimate the proportion of NCC among people with epilepsy (PWE). Overall, 565 articles were retrieved and 290 (51%) selected for further analysis. After a second analytic phase, only 4.5% of articles, all of which used neuroimaging for the diagnosis of NCC, were reviewed. Only two studies, both from the US, estimated an incidence rate of NCC using hospital discharge data. The prevalence of NCC in a random sample of village residents was reported from one study where 9.1% of the population harboured brain lesions of NCC. The proportion of NCC among different study populations varied widely. However, the proportion of NCC in PWE was a lot more consistent. The pooled estimate for this population was 29.0% (95%CI: 22.9%–35.5%). These results were not sensitive to the inclusion or exclusion of any particular study. Conclusion/Significance Only one study has estimated the prevalence of NCC in a random sample of all residents. Hence, the prevalence of NCC worldwide remains unknown. However, the pooled estimate for the proportion of NCC among PWE was very robust and could be used, in conjunction with estimates of the prevalence and incidence of epilepsy, to estimate this component of the burden of NCC in endemic areas. The previously recommended guidelines for the diagnostic process and for declaring NCC an international reportable disease would improve the knowledge on the global frequency of NCC. PMID:21072231

A systematic review of the frequency of neurocyticercosis with a focus on people with epilepsy.

PubMed

Ndimubanzi, Patrick C; Carabin, Hélène; Budke, Christine M; Nguyen, Hai; Qian, Ying-Jun; Rainwater, Elizabeth; Dickey, Mary; Reynolds, Stephanie; Stoner, Julie A

2010-11-02

The objective of this study is to conduct a systematic review of studies reporting the frequency of neurocysticercosis (NCC) worldwide. PubMed, Commonwealth Agricultural Bureau (CAB) abstracts and 23 international databases were systematically searched for articles published from January 1, 1990 to June 1, 2008. Articles were evaluated for inclusion by at least two researchers focusing on study design and methods. Data were extracted independently using standardized forms. A random-effects binomial model was used to estimate the proportion of NCC among people with epilepsy (PWE). Overall, 565 articles were retrieved and 290 (51%) selected for further analysis. After a second analytic phase, only 4.5% of articles, all of which used neuroimaging for the diagnosis of NCC, were reviewed. Only two studies, both from the US, estimated an incidence rate of NCC using hospital discharge data. The prevalence of NCC in a random sample of village residents was reported from one study where 9.1% of the population harboured brain lesions of NCC. The proportion of NCC among different study populations varied widely. However, the proportion of NCC in PWE was a lot more consistent. The pooled estimate for this population was 29.0% (95%CI: 22.9%-35.5%). These results were not sensitive to the inclusion or exclusion of any particular study. Only one study has estimated the prevalence of NCC in a random sample of all residents. Hence, the prevalence of NCC worldwide remains unknown. However, the pooled estimate for the proportion of NCC among PWE was very robust and could be used, in conjunction with estimates of the prevalence and incidence of epilepsy, to estimate this component of the burden of NCC in endemic areas. The previously recommended guidelines for the diagnostic process and for declaring NCC an international reportable disease would improve the knowledge on the global frequency of NCC.

Proposed biokinetic model for phosphorus

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

Leggett, Richard Wayne

2014-06-04

This paper reviews data related to the biokinetics of phosphorus in the human body and proposes a biokinetic model for systemic phosphorus for use in updated International Commission on Radiological Protection (ICRP) guidance on occupational intake of radionuclides. Compared with the ICRP s current occupational model for phosphorus (Publication 68, 1994) the proposed model provides a more realistic description of the paths of movement of phosphorus in the body and improved consistency with experimental, medical, and environmental data on the time-dependent distribution and retention of phosphorus following uptake to blood. For acute uptake of 32P to blood, the proposed modelmore » yields roughly a 50% decrease in dose estimates for bone surface and red marrow and a 6-fold increase in estimates for liver and kidney compared with the biokinetic model of Publication 68 (applying Publication 68 dosimetric models in both sets of calculations). For acute uptake of 33P to blood, the proposed model yields roughly a 50% increase in dose estimates for bone surface and red marrow and a 7-fold increase in estimates for liver and kidney compared with the model of Publication 68.« less

The McCanse Readiness for Death Instrument (MRDI): a reliable and valid measure for hospice care.

PubMed

McCanse, R P

1995-01-01

The purpose of this study was to establish whether or not readiness for death, as an indicator of healthy dying, is a measurable concept. Review of relevant literature revealed consensus regarding the universality of a human need for healthy dying. A theory of healthy dying was derived from the Rogerian paradigm. The McCanse Readiness for Death Instrument (MRDI) was constructed, which included indicators of physiological, psychological, sociological, and spiritual aspects of "healthy" field pattern as death is developmentally approached. The MRDI was a 26-item structured interview questionnaire which generated interval-ratio data through a visual analog scale. A pretest was conducted with a sample of 9 volunteer patients drawn from a small suburban outpatient hospice. The MRDI was concurrently administered to dying individuals, their primary caregivers, and their primary hospice nurses. Correlations between dying individuals' scores and their primary caregivers' estimates of patient death readiness as well as between patients and their primary hospice nurses were very encouraging. Cronbach's coefficient alpha for internal consistency reliability was .59. Content validity was supported by consensus of an expert panel of practicing hospice nurses. Construct validity was demonstrated through legitimate placement of the concept, healthy death readiness, within the theoretical web which supported it. The MRDI was then administered to a sample of 31 terminally-ill individuals, their primary caregivers, and their primary hospice nurses drawn from larger, urban hospice populations in three geographic areas of the United States. The MRDI was also administered to a contrast group of 39 cardiac-impaired individuals who were not terminally-ill. Overall internal consistency of the MRDI was found to be quite favorable (alpha = .76). Debilitating illness and actual mortality in the study sample precluded and/or confounded estimates of test-retest reliability. Convergent validity of the MRDI was indicated by significant correlations between patients' scores and primary caregivers' estimates (r = .35, p < .05) and between patients' scores and primary hospice nurses' estimates (r = .53, p < .01). Discriminant validity of the MRDI was demonstrated by a significant mean difference between the group of terminally-ill patients and the group of non-terminal, cardiac-impaired patients (t = 1.76, p < .01).

Psychometric Properties of the Multidimensional Pain Inventory Applied to Brazilian Patients with Orofacial Pain.

PubMed

Zucoloto, Miriane Lucindo; Maroco, João; Duarte Bonini Campos, Juliana Alvares

2015-01-01

To evaluate the psychometric properties of the Multidimensional Pain Inventory (MPI) in a Brazilian sample of patients with orofacial pain. A total of 1,925 adult patients, who sought dental care in the School of Dentistry of São Paulo State University's Araraquara campus, were invited to participate; 62.5% (n=1,203) agreed to participate. Of these, 436 presented with orofacial pain and were included. The mean age was 39.9 (SD=13.6) years and 74.5% were female. Confirmatory factor analysis was conducted using χ²/df, comparative fit index, goodness of fit index, and root mean square error of approximation as indices of goodness of fit. Convergent validity was estimated by the average variance extracted and composite reliability, and internal consistency by Cronbach's alpha standardized coefficient (α). The stability of the models was tested in independent samples (test and validation; dental pain and orofacial pain). The factorial invariance was estimated by multigroup analysis (Δχ²). Factorial, convergent validity, and internal consistency were adequate in all three parts of the MPI. To achieve this adequate fit for Part 1, item 15 needed to be deleted (λ=0.13). Discriminant validity was compromised between the factors "activities outside the home" and "social activities" of Part 3 of the MPI in the total sample, validation sample, and in patients with dental pain and with orofacial pain. A strong invariance between different subsamples from the three parts of the MPI was detected. The MPI produced valid, reliable, and stable data for pain assessment among Brazilian patients with orofacial pain.

An 'Observational Large Ensemble' to compare observed and modeled temperature trend uncertainty due to internal variability.

NASA Astrophysics Data System (ADS)

Poppick, A. N.; McKinnon, K. A.; Dunn-Sigouin, E.; Deser, C.

2017-12-01

Initial condition climate model ensembles suggest that regional temperature trends can be highly variable on decadal timescales due to characteristics of internal climate variability. Accounting for trend uncertainty due to internal variability is therefore necessary to contextualize recent observed temperature changes. However, while the variability of trends in a climate model ensemble can be evaluated directly (as the spread across ensemble members), internal variability simulated by a climate model may be inconsistent with observations. Observation-based methods for assessing the role of internal variability on trend uncertainty are therefore required. Here, we use a statistical resampling approach to assess trend uncertainty due to internal variability in historical 50-year (1966-2015) winter near-surface air temperature trends over North America. We compare this estimate of trend uncertainty to simulated trend variability in the NCAR CESM1 Large Ensemble (LENS), finding that uncertainty in wintertime temperature trends over North America due to internal variability is largely overestimated by CESM1, on average by a factor of 32%. Our observation-based resampling approach is combined with the forced signal from LENS to produce an 'Observational Large Ensemble' (OLENS). The members of OLENS indicate a range of spatially coherent fields of temperature trends resulting from different sequences of internal variability consistent with observations. The smaller trend variability in OLENS suggests that uncertainty in the historical climate change signal in observations due to internal variability is less than suggested by LENS.

Reliability of a self-report Italian version of the AUDIT-C questionnaire, used to estimate alcohol consumption by pregnant women in an obstetric setting.

PubMed

Bazzo, Stefania; Battistella, Giuseppe; Riscica, Patrizia; Moino, Giuliana; Dal Pozzo, Giuseppe; Bottarel, Mery; Geromel, Mariasole; Czerwinsky, Loredana

2015-01-01

Alcohol consumption during pregnancy can result in a range of harmful effects on the developing foetus and newborn, called Fetal Alcohol Spectrum Disorders (FASD). The identification of pregnant women who use alcohol enables to provide information, support and treatment for women and the surveillance of their children. The AUDIT-C (the shortened consumption version of the Alcohol Use Disorders Identification Test) is used for investigating risky drinking with different populations, and has been applied to estimate alcohol use and risky drinking also in antenatal clinics. The aim of the study was to investigate the reliability of a self-report Italian version of the AUDIT-C questionnaire to detect alcohol consumption during pregnancy, regardless of its use as a screening tool. The questionnaire was filled in by two independent consecutive series of pregnant women at the 38th gestation week visit in the two birth locations of the Local Health Authority of Treviso (Italy), during the years 2010 and 2011 (n=220 and n=239). Reliability analysis was performed using internal consistency, item-total score correlations, and inter-item correlations. The "discriminatory power" of the test was also evaluated. Results. Overall, about one third of women recalled alcohol consumption at least once during the current pregnancy. The questionnaire had an internal consistency of 0.565 for the group of the year 2010, of 0.516 for the year 2011, and of 0.542 for the overall group. The highest item total correlations' coefficient was 0.687 and the highest inter-item correlations' coefficient was 0.675. As for the discriminatory power of the questionnaire, the highest Ferguson's delta coefficient was 0.623. These findings suggest that the Italian self-report version of the AUDIT-C possesses unsatisfactory reliability to estimate alcohol consumption during pregnancy when used as self-report questionnaire in an obstetric setting.

Mass entrainment and turbulence-driven acceleration of ultra-high energy cosmic rays in Centaurus A

NASA Astrophysics Data System (ADS)

Wykes, Sarka; Croston, Judith H.; Hardcastle, Martin J.; Eilek, Jean A.; Biermann, Peter L.; Achterberg, Abraham; Bray, Justin D.; Lazarian, Alex; Haverkorn, Marijke; Protheroe, Ray J.; Bromberg, Omer

2013-10-01

Observations of the FR I radio galaxy Centaurus A in radio, X-ray, and gamma-ray bands provide evidence for lepton acceleration up to several TeV and clues about hadron acceleration to tens of EeV. Synthesising the available observational constraints on the physical conditions and particle content in the jets, inner lobes and giant lobes of Centaurus A, we aim to evaluate its feasibility as an ultra-high-energy cosmic-ray source. We apply several methods of determining jet power and affirm the consistency of various power estimates of ~1 × 1043 erg s-1. Employing scaling relations based on previous results for 3C 31, we estimate particle number densities in the jets, encompassing available radio through X-ray observations. Our model is compatible with the jets ingesting ~3 × 1021 g s-1 of matter via external entrainment from hot gas and ~7 × 1022 g s-1 via internal entrainment from jet-contained stars. This leads to an imbalance between the internal lobe pressure available from radiating particles and magnetic field, and our derived external pressure. Based on knowledge of the external environments of other FR I sources, we estimate the thermal pressure in the giant lobes as 1.5 × 10-12 dyn cm-2, from which we deduce a lower limit to the temperature of ~1.6 × 108 K. Using dynamical and buoyancy arguments, we infer ~440-645 Myr and ~560 Myr as the sound-crossing and buoyancy ages of the giant lobes respectively, inconsistent with their spectral ages. We re-investigate the feasibility of particle acceleration via stochastic processes in the lobes, placing new constraints on the energetics and on turbulent input to the lobes. The same "very hot" temperatures that allow self-consistency between the entrainment calculations and the missing pressure also allow stochastic UHECR acceleration models to work.

Lunar internal structure modeling using Apollo seismic travel time data and the latest selenodetic data from GRAIL and LLR

NASA Astrophysics Data System (ADS)

Matsumoto, K.; Yamada, R.; Kikuchi, F.; Kamata, S.; Ishihara, Y.; Iwata, T.; Hanada, H.; Sasaki, S.

2014-12-01

We tried to constrain lunar internal structure by combining the Apollo seismic travel time data and selenodetic data including those from GRAIL and LLR. We used a seven-layer model consisting of crust, upper mantle, middle mantle, lower mantle, low-velocity layer (LVL), fluid outer core and solid inner core. The model is constrained by the following observations; three selenodetic data of mass, mean moment of inertia, tidal Love number k2 from [1], and Apollo seismic travel time data from [2]. Markov Chain Monte Carlo method is used to infer the model parameters. We collected 140 million samples from 10 chains. Viscosity is not taken into account in this calculation. Mean crustal thickness of 46 ± 4 km is estimated by fitting a normal distribution curve to the posterior distribution, which is to be compared with the previous estimate of 34 - 43 km [3]. Major part of crustal densities is sampled between 2500 and 2600 kg/m3, which is consistent with the value of 2550 kg/m3 reported by [3]. In general, seismic wave velocities in the mantle are consistent with the previous estimates [4][5]. The ranges of size and density of the outer core which satisfy the observation are relatively wide and it is difficult to tightly constrain them. Strong correlation between outer core size and LVL thickness is observed. The smaller outer core should be accompanied by thick LVL and vice versa. When we take into account the upper bound of the fluid core size of 400 km which is predicted by magnetic observation [6], the thickness of the LVL is at least about 100 km. The S-wave velocity within this low-velocity layer is estimated to be less than about 3 km/s. The effect of low viscosity [7] may change the estimate of the S-wave velocity in the LVL. The inner core radius is expected to be smaller than 280 km. The lunar displacement Love number is predicted to be h2= 0.0423 ± 0.0004. References [1] Williams et al. (2014), JGR, doi:10.1002/2013JE004559 [2] Lognonne et al. (2003), EPSL, 211, 27-44 [3] Wieczorek et al. (2012), Science, doi:10.1126/science.1231530 [4] Weber et al. (2011), Science, 331, 309-312, doi:10.1126/science.1199375 [5] Garcia et al. (2011), PEPI, doi:10.1016/j.pepi.2011.06.015 [6] Shimizu et al. (2013), Icarus, doi:10.1016/j.icarus.2012.10.029 [7] Harada et al. (2014), Nature geoscience, doi:10.1038/NGEO2211

Delimiting Coefficient a from Internal Consistency and Unidimensionality

ERIC Educational Resources Information Center

Sijtsma, Klaas

2015-01-01

I discuss the contribution by Davenport, Davison, Liou, & Love (2015) in which they relate reliability represented by coefficient a to formal definitions of internal consistency and unidimensionality, both proposed by Cronbach (1951). I argue that coefficient a is a lower bound to reliability and that concepts of internal consistency and…

Appearance motives to tan and not tan: evidence for validity and reliability of a new scale.

PubMed

Cafri, Guy; Thompson, J Kevin; Roehrig, Megan; Rojas, Ariz; Sperry, Steffanie; Jacobsen, Paul B; Hillhouse, Joel

2008-04-01

Risk for skin cancer is increased by UV exposure and decreased by sun protection. Appearance reasons to tan and not tan have consistently been shown to be related to intentions and behaviors to UV exposure and protection. This study was designed to determine the factor structure of appearance motives to tan and not tan, evaluate the extent to which this factor structure is gender invariant, test for mean differences in the identified factors, and evaluate internal consistency, temporal stability, and criterion-related validity. Five-hundred eighty-nine females and 335 male college students were used to test confirmatory factor analysis models within and across gender groups, estimate latent mean differences, and use the correlation coefficient and Cronbach's alpha to further evaluate the reliability and validity of the identified factors. A measurement invariant (i.e., factor-loading invariant) model was identified with three higher-order factors: sociocultural influences to tan (lower order factors: media, friends, family, significant others), appearance reasons to tan (general, acne, body shape), and appearance reasons not to tan (skin aging, immediate skin damage). Females had significantly higher means than males on all higher-order factors. All subscales had evidence of internal consistency, temporal stability, and criterion-related validity. This study offers a framework and measurement instrument that has evidence of validity and reliability for evaluating appearance-based motives to tan and not tan.

VizieR Online Data Catalog: Face-on disk galaxies photometry. I. (de Jong+, 1994)

NASA Astrophysics Data System (ADS)

de Jong, R. S.; van der Kruit, P. C.

1995-07-01

We present accurate surface photometry in the B, V, R, I, H and K passbands of 86 spiral galaxies. The galaxies in this statistically complete sample of undisturbed spirals were selected from the UGC to have minimum diameters of 2' and minor over major axis ratios larger than 0.625. This sample has been selected in such a way that it can be used to represent a volume limited sample. The observation and reduction techniques are described in detail, especially the not often used driftscan technique for CCDs and the relatively new techniques using near-infrared (near-IR) arrays. For each galaxy we present radial profiles of surface brightness. Using these profiles we calculated the integrated magnitudes of the galaxies in the different passbands. We performed internal and external consistency checks for the magnitudes as well as the luminosity profiles. The internal consistency is well within the estimated errors. Comparisons with other authors indicate that measurements from photographic plates can show large deviations in the zero-point magnitude. Our surface brightness profiles agree within the errors with other CCD measurements. The comparison of integrated magnitudes shows a large scatter, but a consistent zero-point. These measurements will be used in a series of forthcoming papers to discuss central surface brightnesses, scalelengths, colors and color gradients of disks of spiral galaxies. (9 data files).

Online machining error estimation method of numerical control gear grinding machine tool based on data analysis of internal sensors

NASA Astrophysics Data System (ADS)

Zhao, Fei; Zhang, Chi; Yang, Guilin; Chen, Chinyin

2016-12-01

This paper presents an online estimation method of cutting error by analyzing of internal sensor readings. The internal sensors of numerical control (NC) machine tool are selected to avoid installation problem. The estimation mathematic model of cutting error was proposed to compute the relative position of cutting point and tool center point (TCP) from internal sensor readings based on cutting theory of gear. In order to verify the effectiveness of the proposed model, it was simulated and experimented in gear generating grinding process. The cutting error of gear was estimated and the factors which induce cutting error were analyzed. The simulation and experiments verify that the proposed approach is an efficient way to estimate the cutting error of work-piece during machining process.

Covariate selection with group lasso and doubly robust estimation of causal effects.

PubMed

Koch, Brandon; Vock, David M; Wolfson, Julian

2018-03-01

The efficiency of doubly robust estimators of the average causal effect (ACE) of a treatment can be improved by including in the treatment and outcome models only those covariates which are related to both treatment and outcome (i.e., confounders) or related only to the outcome. However, it is often challenging to identify such covariates among the large number that may be measured in a given study. In this article, we propose GLiDeR (Group Lasso and Doubly Robust Estimation), a novel variable selection technique for identifying confounders and predictors of outcome using an adaptive group lasso approach that simultaneously performs coefficient selection, regularization, and estimation across the treatment and outcome models. The selected variables and corresponding coefficient estimates are used in a standard doubly robust ACE estimator. We provide asymptotic results showing that, for a broad class of data generating mechanisms, GLiDeR yields a consistent estimator of the ACE when either the outcome or treatment model is correctly specified. A comprehensive simulation study shows that GLiDeR is more efficient than doubly robust methods using standard variable selection techniques and has substantial computational advantages over a recently proposed doubly robust Bayesian model averaging method. We illustrate our method by estimating the causal treatment effect of bilateral versus single-lung transplant on forced expiratory volume in one year after transplant using an observational registry. © 2017, The International Biometric Society.

Internal trip capture estimator for mixed-use developments.

DOT National Transportation Integrated Search

2007-12-01

This report describes a spreadsheet tool for estimating trip generation for mixed-use developments, : accounting for internal trip capture. Internal trip capture is the portion of trips generated by a mixed-use : development that both begin and end w...

The International DORIS Service contribution to the 2014 realization of the International Terrestrial Reference Frame

NASA Astrophysics Data System (ADS)

Moreaux, Guilhem; Lemoine, Frank G.; Capdeville, Hugues; Kuzin, Sergey; Otten, Michiel; Štěpánek, Petr; Willis, Pascal; Ferrage, Pascale

2016-12-01

In preparation of the 2014 realization of the International Terrestrial Reference Frame (ITRF2014), the International DORIS Service delivered to the International Earth Rotation and Reference Systems Service a set of 1140 weekly solution files including station coordinates and Earth orientation parameters, covering the time period from 1993.0 to 2015.0. The data come from eleven DORIS satellites: TOPEX/Poseidon, SPOT2, SPOT3, SPOT4, SPOT5, Envisat, Jason-1, Jason-2, Cryosat-2, Saral and HY-2A. In their processing, the six analysis centers which contributed to the DORIS combined solution used the latest time variable gravity models and estimated DORIS ground beacon frequency variations. Furthermore, all the analysis centers but one excepted included in their processing phase center variations for ground antennas. The main objective of this study is to present the combination process and to analyze the impact of the new modeling on the performance of the new combined solution. Comparisons with the IDS contribution to ITRF2008 show that (i) the application of the DORIS ground phase center variations in the data processing shifts the combined scale upward by nearly 7-11 mm and (ii) thanks to estimation of DORIS ground beacon frequency variations, the new combined solution no longer shows any scale discontinuity in early 2002 and does not present unexplained vertical discontinuities in any station position time series. However, analysis of the new series with respect to ITRF2008 exhibits a scale increase late 2011 which is not yet explained. A new DORIS Terrestrial Reference Frame was computed to evaluate the intrinsic quality of the new combined solution. That evaluation shows that the addition of data from the new missions equipped with the latest generation of DORIS receiver (Jason-2, Cryosat-2, HY-2A, Saral), results in an internal position consistency of 10 mm or better after mid-2008.

Reliability of perceived neighbourhood conditions and the effects of measurement error on self-rated health across urban and rural neighbourhoods.

PubMed

Pruitt, Sandi L; Jeffe, Donna B; Yan, Yan; Schootman, Mario

2012-04-01

Limited psychometric research has examined the reliability of self-reported measures of neighbourhood conditions, the effect of measurement error on associations between neighbourhood conditions and health, and potential differences in the reliabilities between neighbourhood strata (urban vs rural and low vs high poverty). We assessed overall and stratified reliability of self-reported perceived neighbourhood conditions using five scales (social and physical disorder, social control, social cohesion, fear) and four single items (multidimensional neighbouring). We also assessed measurement error-corrected associations of these conditions with self-rated health. Using random-digit dialling, 367 women without breast cancer (matched controls from a larger study) were interviewed twice, 2-3 weeks apart. Test-retest (intraclass correlation coefficients (ICC)/weighted κ) and internal consistency reliability (Cronbach's α) were assessed. Differences in reliability across neighbourhood strata were tested using bootstrap methods. Regression calibration corrected estimates for measurement error. All measures demonstrated satisfactory internal consistency (α ≥ 0.70) and either moderate (ICC/κ=0.41-0.60) or substantial (ICC/κ=0.61-0.80) test-retest reliability in the full sample. Internal consistency did not differ by neighbourhood strata. Test-retest reliability was significantly lower among rural (vs urban) residents for two scales (social control, physical disorder) and two multidimensional neighbouring items; test-retest reliability was higher for physical disorder and lower for one multidimensional neighbouring item among the high (vs low) poverty strata. After measurement error correction, the magnitude of associations between neighbourhood conditions and self-rated health were larger, particularly in the rural population. Research is needed to develop and test reliable measures of perceived neighbourhood conditions relevant to the health of rural populations.

Reassessment of the psychometric characteristics and factor structure of the 'Perceived Stress Questionnaire' (PSQ): analysis in a sample of dental students.

PubMed

Montero-Marin, Jesús; Piva Demarzo, Marcelo Marcos; Pereira, Joao Paulo; Olea, Marina; García-Campayo, Javier

2014-01-01

The training to become a dentist can create psychological distress. The present study evaluates the structure of the 'Perceived Stress Questionnaire' (PSQ), its internal consistency model and interrelatedness with burnout, anxiety, depression and resilience among dental students. The study employed a cross-sectional design. A sample of Spanish dental students (n = 314) completed the PSQ, the 'Goldberg Anxiety and Depression Scale' (GADS), 'Connor-Davidson Resilience Scale' (10-item CD-RISC) and 'Maslach Burnout Inventory-Student Survey' (MBI-SS). The structure was estimated using Parallel Analysis from polychoric correlations. Unweighted Least Squares was the method for factor extraction, using the Item Response Theory to evaluate the discriminative power of items. Internal consistency was assessed by squaring the correlation between the latent true variable and the observed variable. The relationships between the PSQ and the other constructs were analysed using Spearman's coefficient. The results showed a PSQ structure through two sub-factors ('frustration' and 'tenseness') with regard to one general factor ('perceived stress'). Items that did not satisfy discriminative capacity were rejected. The model fit were acceptable (GFI = 0.98; RSMR = 0.06; AGFI = 0.98; NFI = 0.98; RFI = 0.98). All the factors showed adequate internal consistency as measured by the congeneric model (≥0.91). High and significant associations were observed between perceived stress and burnout, anxiety, depression and resilience. The PSQ showed a hierarchical bi-factor structure among Spanish dental students. Using the questionnaire as a uni-dimensional scale may be useful in perceived stress level discrimination, while the sub-factors could help us to refine perceived stress analysis and improve therapeutic processes.

Statistical Validation of a Web-Based GIS Application and Its Applicability to Cardiovascular-Related Studies.

PubMed

Lee, Jae Eun; Sung, Jung Hye; Malouhi, Mohamad

2015-12-22

There is abundant evidence that neighborhood characteristics are significantly linked to the health of the inhabitants of a given space within a given time frame. This study is to statistically validate a web-based GIS application designed to support cardiovascular-related research developed by the NIH funded Research Centers in Minority Institutions (RCMI) Translational Research Network (RTRN) Data Coordinating Center (DCC) and discuss its applicability to cardiovascular studies. Geo-referencing, geocoding and geospatial analyses were conducted for 500 randomly selected home addresses in a U.S. southeastern Metropolitan area. The correlation coefficient, factor analysis and Cronbach's alpha (α) were estimated to quantify measures of the internal consistency, reliability and construct/criterion/discriminant validity of the cardiovascular-related geospatial variables (walk score, number of hospitals, fast food restaurants, parks and sidewalks). Cronbach's α for CVD GEOSPATIAL variables was 95.5%, implying successful internal consistency. Walk scores were significantly correlated with number of hospitals (r = 0.715; p < 0.0001), fast food restaurants (r = 0.729; p < 0.0001), parks (r = 0.773; p < 0.0001) and sidewalks (r = 0.648; p < 0.0001) within a mile from homes. It was also significantly associated with diversity index (r = 0.138, p = 0.0023), median household incomes (r = -0.181; p < 0.0001), and owner occupied rates (r = -0.440; p < 0.0001). However, its non-significant correlation was found with median age, vulnerability, unemployment rate, labor force, and population growth rate. Our data demonstrates that geospatial data generated by the web-based application were internally consistent and demonstrated satisfactory validity. Therefore, the GIS application may be useful to apply to cardiovascular-related studies aimed to investigate potential impact of geospatial factors on diseases and/or the long-term effect of clinical trials.

Reassessment of the Psychometric Characteristics and Factor Structure of the ‘Perceived Stress Questionnaire’ (PSQ): Analysis in a Sample of Dental Students

PubMed Central

Montero-Marin, Jesús; Piva Demarzo, Marcelo Marcos; Pereira, Joao Paulo; Olea, Marina; García-Campayo, Javier

2014-01-01

Background The training to become a dentist can create psychological distress. The present study evaluates the structure of the ‘Perceived Stress Questionnaire’ (PSQ), its internal consistency model and interrelatedness with burnout, anxiety, depression and resilience among dental students. Methods The study employed a cross-sectional design. A sample of Spanish dental students (n = 314) completed the PSQ, the ‘Goldberg Anxiety and Depression Scale’ (GADS), ‘Connor-Davidson Resilience Scale’ (10-item CD-RISC) and ‘Maslach Burnout Inventory-Student Survey’ (MBI-SS). The structure was estimated using Parallel Analysis from polychoric correlations. Unweighted Least Squares was the method for factor extraction, using the Item Response Theory to evaluate the discriminative power of items. Internal consistency was assessed by squaring the correlation between the latent true variable and the observed variable. The relationships between the PSQ and the other constructs were analysed using Spearman’s coefficient. Results The results showed a PSQ structure through two sub-factors (‘frustration’ and ‘tenseness’) with regard to one general factor (‘perceived stress’). Items that did not satisfy discriminative capacity were rejected. The model fit were acceptable (GFI = 0.98; RSMR = 0.06; AGFI = 0.98; NFI = 0.98; RFI = 0.98). All the factors showed adequate internal consistency as measured by the congeneric model (≥0.91). High and significant associations were observed between perceived stress and burnout, anxiety, depression and resilience. Conclusions The PSQ showed a hierarchical bi-factor structure among Spanish dental students. Using the questionnaire as a uni-dimensional scale may be useful in perceived stress level discrimination, while the sub-factors could help us to refine perceived stress analysis and improve therapeutic processes. PMID:24466330

Cross-cultural adaptation and measurement properties of the italian version of the Patient-Rated Tennis Elbow Evaluation (PRTEE) questionnaire.

PubMed

Cacchio, Angelo; Necozione, Stefano; MacDermid, Joy C; Rompe, Jan Dirk; Maffulli, Nicola; di Orio, Ferdinando; Santilli, Valter; Paoloni, Marco

2012-08-01

The Patient-Rated Tennis Elbow Evaluation (PRTEE) questionnaire is a tool designed for self-assessment of forearm pain and disability in patients with lateral elbow tendinopathy (LET). However, an Italian version of this questionnaire has not been available. The aims of this study were: (1) to translate and cross-culturally adapt the PRTEE questionnaire into Italian and (2) to evaluate its measurement properties. This was a longitudinal, observational measurement study. The PRTEE questionnaire was cross-culturally adapted to Italian according to established guidelines. Ninety-five individuals (41 women, 54 men) with unilateral, imaging-confirmed, chronic LET were selected consecutively to assess the measurement properties of the PRTEE questionnaire. Internal consistency, test-retest reliability, construct validity, and responsiveness were estimated. The Italian version of the PRTEE displayed a high degree of internal consistency, with a Cronbach alpha of .95. The test-retest reliability was high for both short-term and medium-term, with intraclass correlation coefficients (2,1) of .95 and .93, respectively. The PRTEE exhibited a strong correlation (r=.77-.91, P<.0001) with the Disabilities of the Arm, Shoulder and Hand (DASH) at the baseline and a moderate correlation (r=.58-.74, P<.0001) at discharge. The responsiveness was higher for the PRTEE than for the DASH. Limitations A methodological limitation of the study is that due to the small sample size, a factor analysis was not performed to assess convergent validity. The Italian version of the PRTEE questionnaire is internally consistent, demonstrates expected correlations with other measures, and is more responsive than the DASH in Italian patients with chronic LET.

Atlantic Ocean CARINA data: overview and salinity adjustments

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

Tanhua, T.; Steinfeldt, R.; Key, Robert

2010-01-01

Water column data of carbon and carbon-relevant hydrographic and hydrochemical parameters from 188 previously non-publicly available cruise data sets in the Arctic Mediterranean Seas, Atlantic and Southern Ocean have been retrieved and merged into a new database: CARINA (CARbon dioxide IN the Atlantic Ocean). The data have gone through rigorous quality control procedures to assure the highest possible quality and consistency. The data for the pertinent parameters in the CARINA database were objectively examined in order to quantify systematic differences in the reported values, i.e. secondary quality control. Systematic biases found in the data have been corrected in the threemore » data products: merged data files with measured, calculated and interpolated data for each of the three CARINA regions, i.e. the Arctic Mediterranean Seas, the Atlantic and the Southern Ocean. These products have been corrected to be internally consistent. Ninety-eight of the cruises in the CARINA database were conducted in the Atlantic Ocean, defined here as the region south of the Greenland-Iceland-Scotland Ridge and north of about 30 S. Here we present an overview of the Atlantic Ocean synthesis of the CARINA data and the adjustments that were applied to the data product. We also report the details of the secondary QC (Quality Control) for salinity for this data set. Procedures of quality control including crossover analysis between stations and inversion analysis of all crossover data are briefly described. Adjustments to salinity measurements were applied to the data from 10 cruises in the Atlantic Ocean region. Based on our analysis we estimate the internal consistency of the CARINA-ATL salinity data to be 4.1 ppm. With these adjustments the CARINA data products are consistent both internally was well as with GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s, and is now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates and for model validation.« less

Test-retest reliability and comparability of paper and computer questionnaires for the Finnish version of the Tampa Scale of Kinesiophobia.

PubMed

Koho, P; Aho, S; Kautiainen, H; Pohjolainen, T; Hurri, H

2014-12-01

To estimate the internal consistency, test-retest reliability and comparability of paper and computer versions of the Finnish version of the Tampa Scale of Kinesiophobia (TSK-FIN) among patients with chronic pain. In addition, patients' personal experiences of completing both versions of the TSK-FIN and preferences between these two methods of data collection were studied. Test-retest reliability study. Paper and computer versions of the TSK-FIN were completed twice on two consecutive days. The sample comprised 94 consecutive patients with chronic musculoskeletal pain participating in a pain management or individual rehabilitation programme. The group rehabilitation design consisted of physical and functional exercises, evaluation of the social situation, psychological assessment of pain-related stress factors, and personal pain management training in order to regain overall function and mitigate the inconvenience of pain and fear-avoidance behaviour. The mean TSK-FIN score was 37.1 [standard deviation (SD) 8.1] for the computer version and 35.3 (SD 7.9) for the paper version. The mean difference between the two versions was 1.9 (95% confidence interval 0.8 to 2.9). Test-retest reliability was 0.89 for the paper version and 0.88 for the computer version. Internal consistency was considered to be good for both versions. The intraclass correlation coefficient for comparability was 0.77 (95% confidence interval 0.66 to 0.85), indicating substantial reliability between the two methods. Both versions of the TSK-FIN demonstrated substantial intertest reliability, good test-retest reliability, good internal consistency and acceptable limits of agreement, suggesting their suitability for clinical use. However, subjects tended to score higher when using the computer version. As such, in an ideal situation, data should be collected in a similar manner throughout the course of rehabilitation or clinical research. Copyright © 2014 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Fundamentals of endoscopic surgery: creation and validation of the hands-on test.

PubMed

Vassiliou, Melina C; Dunkin, Brian J; Fried, Gerald M; Mellinger, John D; Trus, Thadeus; Kaneva, Pepa; Lyons, Calvin; Korndorffer, James R; Ujiki, Michael; Velanovich, Vic; Kochman, Michael L; Tsuda, Shawn; Martinez, Jose; Scott, Daniel J; Korus, Gary; Park, Adrian; Marks, Jeffrey M

2014-03-01

The Fundamentals of Endoscopic Surgery™ (FES) program consists of online materials and didactic and skills-based tests. All components were designed to measure the skills and knowledge required to perform safe flexible endoscopy. The purpose of this multicenter study was to evaluate the reliability and validity of the hands-on component of the FES examination, and to establish the pass score. Expert endoscopists identified the critical skill set required for flexible endoscopy. They were then modeled in a virtual reality simulator (GI Mentor™ II, Simbionix™ Ltd., Airport City, Israel) to create five tasks and metrics. Scores were designed to measure both speed and precision. Validity evidence was assessed by correlating performance with self-reported endoscopic experience (surgeons and gastroenterologists [GIs]). Internal consistency of each test task was assessed using Cronbach's alpha. Test-retest reliability was determined by having the same participant perform the test a second time and comparing their scores. Passing scores were determined by a contrasting groups methodology and use of receiver operating characteristic curves. A total of 160 participants (17 % GIs) performed the simulator test. Scores on the five tasks showed good internal consistency reliability and all had significant correlations with endoscopic experience. Total FES scores correlated 0.73, with participants' level of endoscopic experience providing evidence of their validity, and their internal consistency reliability (Cronbach's alpha) was 0.82. Test-retest reliability was assessed in 11 participants, and the intraclass correlation was 0.85. The passing score was determined and is estimated to have a sensitivity (true positive rate) of 0.81 and a 1-specificity (false positive rate) of 0.21. The FES hands-on skills test examines the basic procedural components required to perform safe flexible endoscopy. It meets rigorous standards of reliability and validity required for high-stakes examinations, and, together with the knowledge component, may help contribute to the definition and determination of competence in endoscopy.

Atlantic Ocean CARINA data: overview and salinity adjustments

NASA Astrophysics Data System (ADS)

Tanhua, T.; Steinfeldt, R.; Key, R. M.; Brown, P.; Gruber, N.; Wanninkhof, R.; Perez, F.; Körtzinger, A.; Velo, A.; Schuster, U.; van Heuven, S.; Bullister, J. L.; Stendardo, I.; Hoppema, M.; Olsen, A.; Kozyr, A.; Pierrot, D.; Schirnick, C.; Wallace, D. W. R.

2010-02-01

Water column data of carbon and carbon-relevant hydrographic and hydrochemical parameters from 188 previously non-publicly available cruise data sets in the Arctic Mediterranean Seas, Atlantic and Southern Ocean have been retrieved and merged into a new database: CARINA (CARbon dioxide IN the Atlantic Ocean). The data have gone through rigorous quality control procedures to assure the highest possible quality and consistency. The data for the pertinent parameters in the CARINA database were objectively examined in order to quantify systematic differences in the reported values, i.e. secondary quality control. Systematic biases found in the data have been corrected in the three data products: merged data files with measured, calculated and interpolated data for each of the three CARINA regions, i.e. the Arctic Mediterranean Seas, the Atlantic and the Southern Ocean. These products have been corrected to be internally consistent. Ninety-eight of the cruises in the CARINA database were conducted in the Atlantic Ocean, defined here as the region south of the Greenland-Iceland-Scotland Ridge and north of about 30° S. Here we present an overview of the Atlantic Ocean synthesis of the CARINA data and the adjustments that were applied to the data product. We also report the details of the secondary QC (Quality Control) for salinity for this data set. Procedures of quality control - including crossover analysis between stations and inversion analysis of all crossover data - are briefly described. Adjustments to salinity measurements were applied to the data from 10 cruises in the Atlantic Ocean region. Based on our analysis we estimate the internal consistency of the CARINA-ATL salinity data to be 4.1 ppm. With these adjustments the CARINA data products are consistent both internally as well as with GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s, and is now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates and for model validation.

Marginal regression analysis of recurrent events with coarsened censoring times.

PubMed

Hu, X Joan; Rosychuk, Rhonda J

2016-12-01

Motivated by an ongoing pediatric mental health care (PMHC) study, this article presents weakly structured methods for analyzing doubly censored recurrent event data where only coarsened information on censoring is available. The study extracted administrative records of emergency department visits from provincial health administrative databases. The available information of each individual subject is limited to a subject-specific time window determined up to concealed data. To evaluate time-dependent effect of exposures, we adapt the local linear estimation with right censored survival times under the Cox regression model with time-varying coefficients (cf. Cai and Sun, Scandinavian Journal of Statistics 2003, 30, 93-111). We establish the pointwise consistency and asymptotic normality of the regression parameter estimator, and examine its performance by simulation. The PMHC study illustrates the proposed approach throughout the article. © 2016, The International Biometric Society.

Reliability and validity of the McDonald Play Inventory.

PubMed

McDonald, Ann E; Vigen, Cheryl

2012-01-01

This study examined the ability of a two-part self-report instrument, the McDonald Play Inventory, to reliably and validly measure the play activities and play styles of 7- to 11-yr-old children and to discriminate between the play of neurotypical children and children with known learning and developmental disabilities. A total of 124 children ages 7-11 recruited from a sample of convenience and a subsample of 17 parents participated in this study. Reliability estimates yielded moderate correlations for internal consistency, total test intercorrelations, and test-retest reliability. Validity estimates were established for content and construct validity. The results suggest that a self-report instrument yields reliable and valid measures of a child's perceived play performance and discriminates between the play of children with and without disabilities. Copyright © 2012 by the American Occupational Therapy Association, Inc.

GGFC Special Bureau for Loading: current status and plans

NASA Astrophysics Data System (ADS)

van Dam, T.; Plag, H.-P.; Francis, O.; Gegout, P.

The Earth's surface is perpetually being displaced due to temporally varying atmospheric, oceanic and continental water mass surface loads. These non-geodynamic signals are of substantial magnitude that they contribute significantly to the scatter in geodetic observations of crustal motion. In February, 2002, the International Earth Rotation Service (IERS) established a Special Bureau of Loading (SBL) whose primary charge is to provide consistent and valid estimates of surface mass loading effects to the IERS community for the purpose of correcting geodetic time series. Here we outline the primary principles involved in modelling the surface displacements and gravity changes induced by surface mass loading including the basic theory, the Earth model and the surface load data. We then identify a list of operational issues, including product validation, that need to be addressed by the SBL before products can be provided to the community. Finally, we outline areas for future research to further improve the loading estimates. We conclude by formulating a recommendation on the best procedure for including loading corrections into geodetic data. Success of the SBL will depend on our ability to efficiently provide consistent and reliable estimates of surface mass loading effects. It is imperative that we work closely with the existing Global Geophysical Fluids Center (GGFC) Special Bureaus and with the community to as much as possible to verify the products.

National Renewable Energy Laboratory Pyrheliometer Comparisons: 24 September - 5 October 2012 (NPC-2012)

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

Stoffel, T.; Reda, I.

2013-05-01

The NREL Pyrheliometer Comparisons for 2012 (NPC-2012) were held at the Solar Radiation Research Laboratory in Golden, Colorado, from September 24 through October 5 for the purpose of transferring the World Radiometric Reference (WRR) to participating instrument. Twenty scientists and engineers operated 32 absolute cavity radiometers and 18 conventional thermopile-based pyrheliometers to simultaneously measure clear-sky direct normal irradiance during the comparisons. The transfer standard group of reference radiometers for NPC-2012 consisted of four NREL radiometers with direct traceability to the WRR, having participated in the Eleventh International Pyrheliometer Comparisons (IPC-XI) hosted by the World Radiation Center in the fall ofmore » 2010. As the result of NPC-2012, each participating absolute cavity radiometer was assigned a new WRR transfer factor, computed as the reference irradiance computed by the transfer standard group divided by the observed irradiance from the participating radiometer. The performance of the transfer standard group during NPC-2012 was consistent with previous comparisons, including IPC-XI. The measurement performance of the transfer standard group allowed the transfer of the WRR to each participating radiometer with an estimated uncertainty of +/- 0.33% with respect to the International System of Units.« less

Reliability of the Cooking Task in adults with acquired brain injury.

PubMed

Poncet, Frédérique; Swaine, Bonnie; Taillefer, Chantal; Lamoureux, Julie; Pradat-Diehl, Pascale; Chevignard, Mathilde

2015-01-01

Acquired brain injury (ABI) often leads to deficits in executive functioning (EF) responsible for severe and long-standing disabilities in daily life activities. The Cooking Task is an ecological and valid test of EF involving multi-tasking in a real environment. Given its complex scoring system, it is important to establish the tool's reliability. The objective of the study was to examine the reliability of the Cooking Task (internal consistency, inter-rater and test-retest reliability). A total of 160 patients with ABI (113 men, mean age 37 years, SD = 14.3) were tested using the Cooking Task. For test-retest reliability, patients were assessed by the same rater on two occasions (mean interval 11 days) while two raters independently and simultaneously observed and scored patients' performances to estimate inter-rater reliability. Internal consistency was high for the global scale (Cronbach α = .74). Inter-rater reliability (n = 66) for total errors was also high (ICC = .93), however the test-retest reliability (n = 11) was poor (ICC = .36). In general the Cooking Task appears to be a reliable tool. The low test-retest results were expected given the importance of EF in the performance of novel tasks.

Developing a measure of cultural-, maturity-, or esteem-driven modesty among Jewish women.

PubMed

Andrews, Caryn Scheinberg

2014-01-01

Understanding modesty and how it relates to religiosity among Jewish women was relatively unexplained, and as part of a larger study, a measure was needed. The purpose of this article is to report on three studies which represent the three stages of instrument development of a measure of modesty among Jewish women, "Your Views of Modesty": (a) content/concept definition; (b) instrument development; and (c) evaluation of the psychometric properties of the instrument: reliability and validity. In Study I, Q methodology was used to define the domain and results suggesting that modesty has multidimensions. In Study II, an instrument was developed based on distinctive perspectives from each group or what was important and not so important. This formed a 25-item Likert scale. In Study III, a survey of 300 Jewish women revealed internal consistency estimates with Cronbach's alpha 0.92, indicating high degree of internal consistency reliability for "Your Views of Modesty." For construct validity, four factors were found explaining 55% of the variance of modesty: (a) religion-driven, (b) maturity-driven, (c) esteem-driven, and (d) public-based modesty was identified. "Your Views of Modesty" shows good evidence for reliability and validity in this Jewish population.

Estimating and testing interactions when explanatory variables are subject to non-classical measurement error.

PubMed

Murad, Havi; Kipnis, Victor; Freedman, Laurence S

2016-10-01

Assessing interactions in linear regression models when covariates have measurement error (ME) is complex.We previously described regression calibration (RC) methods that yield consistent estimators and standard errors for interaction coefficients of normally distributed covariates having classical ME. Here we extend normal based RC (NBRC) and linear RC (LRC) methods to a non-classical ME model, and describe more efficient versions that combine estimates from the main study and internal sub-study. We apply these methods to data from the Observing Protein and Energy Nutrition (OPEN) study. Using simulations we show that (i) for normally distributed covariates efficient NBRC and LRC were nearly unbiased and performed well with sub-study size ≥200; (ii) efficient NBRC had lower MSE than efficient LRC; (iii) the naïve test for a single interaction had type I error probability close to the nominal significance level, whereas efficient NBRC and LRC were slightly anti-conservative but more powerful; (iv) for markedly non-normal covariates, efficient LRC yielded less biased estimators with smaller variance than efficient NBRC. Our simulations suggest that it is preferable to use: (i) efficient NBRC for estimating and testing interaction effects of normally distributed covariates and (ii) efficient LRC for estimating and testing interactions for markedly non-normal covariates. © The Author(s) 2013.

Evaluation of Dimensionality in the Assessment of Internal Consistency Reliability: Coefficient Alpha and Omega Coefficients

ERIC Educational Resources Information Center

Green, Samuel B.; Yang, Yanyun

2015-01-01

In the lead article, Davenport, Davison, Liou, & Love demonstrate the relationship among homogeneity, internal consistency, and coefficient alpha, and also distinguish among them. These distinctions are important because too often coefficient alpha--a reliability coefficient--is interpreted as an index of homogeneity or internal consistency.…

Robust versus consistent variance estimators in marginal structural Cox models.

PubMed

Enders, Dirk; Engel, Susanne; Linder, Roland; Pigeot, Iris

2018-06-11

In survival analyses, inverse-probability-of-treatment (IPT) and inverse-probability-of-censoring (IPC) weighted estimators of parameters in marginal structural Cox models are often used to estimate treatment effects in the presence of time-dependent confounding and censoring. In most applications, a robust variance estimator of the IPT and IPC weighted estimator is calculated leading to conservative confidence intervals. This estimator assumes that the weights are known rather than estimated from the data. Although a consistent estimator of the asymptotic variance of the IPT and IPC weighted estimator is generally available, applications and thus information on the performance of the consistent estimator are lacking. Reasons might be a cumbersome implementation in statistical software, which is further complicated by missing details on the variance formula. In this paper, we therefore provide a detailed derivation of the variance of the asymptotic distribution of the IPT and IPC weighted estimator and explicitly state the necessary terms to calculate a consistent estimator of this variance. We compare the performance of the robust and consistent variance estimators in an application based on routine health care data and in a simulation study. The simulation reveals no substantial differences between the 2 estimators in medium and large data sets with no unmeasured confounding, but the consistent variance estimator performs poorly in small samples or under unmeasured confounding, if the number of confounders is large. We thus conclude that the robust estimator is more appropriate for all practical purposes. Copyright © 2018 John Wiley & Sons, Ltd.

Energy environment study

NASA Technical Reports Server (NTRS)

Strangways, R.

1981-01-01

The international demand for and supply of oil between the years 1980 and 2000 is assessed and future world oil prices and their implications for the price of jet fuel are estimated. Three critical questions are investigated: (1) how long will the world supply of oil continue to keep pace with its demand under likely trends in its use and discovery; (2) at what price will demand and supply clear the world oil market; (3) what does the analysis imply about the price of jet fuel. Projection of oil price is based upon supply and demand, which is consistent with microeconomic analysis.

Bayes estimation: A novel approach to derivation of internally consistent thermodynamic data for minerals, their uncertainties, and correlations. Part II: Application

NASA Astrophysics Data System (ADS)

Chatterjee, Niranjan D.; Miller, Klaus; Olbricht, Walter

1994-05-01

Internally consistent thermodynamic data, including their uncertainties and correlations, are reported for 22 phases of the quaternary system CaO-Al2O3-SiO2-H2O. These data have been derived by simultaneous evaluation of the appropriate phase properties (PP) and reaction properties (RP) by the novel technique of Bayes estimation (BE). The thermodynamic model used and the theory of BE was expounded in Part I of this paper. Part II is the follow-up study illustrating an application of BE. The input for BE comprised, among others, the a priori values for standard enthalpy of formation of the i-th phase, Δf H {/i 0}, and its standard entropy, S {/i 0}, in addition to the reaction reversal constraints for 33 equilibria involving the relevant phases. A total of 269 RP restrictions have been processed, of which 107 turned out to be non-redundant. The refined values for Δf H {/i 0}and S {/i 0}obtained by BE, including their 2σ-uncertainties, appear in Table 4; the Appendix reproduces the corresponding correlation matrix. These data permit generation of computed phase diagrams with 2σ-uncertainty envelopes based on conventional error propagation; Fig. 3 depicts such a phase diagram for the system CaO-Al2O3-SiO2. It shows that the refined dataset is capable of yielding phase diagrams with uncertainty envelopes narrow enough to be geologically useful. The results in Table 4 demonstrate that the uncertainties of the prior values for Δf H {/i Emphasis>0}, given in Table 1, have decreased by up to an order of magnitude, while those for S {/i 0}improved by a factor of up to two. For comparison, Table 4 also lists the refined Δf H {/i 0}and S {/i 0}data obtained by mathematical programming (MAP), minimizing a quadratic objective function used earlier by Berman (1988). Examples of calculated phase diagrams are given to demonstrate the advantages of BE for deriving internally consistent thermodynamic data. Although P-T curves generated from both MAP and BE databases will pass through the reversal restrictions, BE datasets appear to be better suited for extrapolations beyond the P-T range explored experimentally and for predicting equilibria not constrained by reversals.

A micromixer with consistent mixing performance for a wide range of flow rates.

PubMed

Goovaerts, Robert; Van Assche, Tom; Sonck, Marc; Denayer, Joeri; Desmet, Gert

2015-02-01

A micromixer with consistent mixing performance for a wide range of flow rates is presented. The mixer makes use of internally moving elements, i.e. steel balls that are located in dedicated mixing chambers. Movement is induced by a rotating magnetic field. To get better insight in differences between active and passive mixing, we studied a mixer that can operate in both regimes. A mixing performance study for a range of flow rates along with pressure drop data is presented. The response of the moving elements in regard to the magnetic field is shown experimentally and shows the limitations of earlier modeling studies. Lastly, the estimated power input on the fluids was calculated and allows for a comparison with more well-known convective-type mixers. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Engaging with local stakeholders: some lessons from Fukushima for recovery.

PubMed

Hayano, R S

2015-06-01

The Fukushima Daiichi nuclear power plant accident contaminated the soil of densely populated regions in Fukushima prefecture with radioactive caesium, which poses significant risks of internal and external exposure to the residents. Applying the knowledge of post-Chernobyl accident studies, internal exposures in excess of a few mSv per year would be expected to be common in Fukushima. However, extensive whole-body-counter surveys have shown that the internal exposure levels of residents are much lower than estimated; in 2012-2013, the Cs-137 detection percentages (the detection limit being ∼300 Bq body(-1)) were approximately 1% for adults and practically 0% for children. These results are consistent with those of many other measurements/studies conducted to date in Fukushima. As a consequence, risks from external exposure assume greater importance for the majority of residents in Fukushima due to the lower contribution from internal exposure. In both cases, average doses remain low, although some residents are exposed to higher-than-average risks; it is these members of the population who need to be identified and followed-up. Consequently, it is essential to re-establish communication at all levels in society. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Estimation of hydraulic permeability considering the micro morphology of rocks of the borehole YAXCOPOIL-1 (Impact crater Chicxulub, Mexico)

NASA Astrophysics Data System (ADS)

Mayr, S. I.; Burkhardt, H.; Popov, Yu.; Wittmann, A.

2008-04-01

Internal surface, formation factor, Nuclear Magnetic Resonance (NMR)-T2 relaxation times and pore radius distributions were measured on representative core samples for the estimation of hydraulic permeability. Permeability is estimated using various versions of the classic Kozeny-Carman-equation (K-C) and a further development of K-C, the fractal PaRiS-model, taking into account the internal surface. In addition to grain and pore size distribution, directly connected to permeability, internal surface reflects the internal structure (“micro morphology”). Lithologies could be grouped with respect to differences in internal surface. Most melt rich impact breccia lithologies exhibit large internal surfaces, while Tertiary post-impact sediments and Cretaceous lithologies in displaced megablocks display smaller internal surfaces. Investigations with scanning electron microscopy confirm the correlation between internal surface and micro morphology. In addition to different versions of K-C, estimations by means of NMR, pore radius distributions and some gas permeability measurements serve for cross-checking and calibration. In general, the different estimations from the independent methods and the measurements are in satisfactory accordance. For Tertiary limestones and Suevites bulk with very high porosities (up to 35%) permeabilites between 10-14 and 10-16 m2 are found, whereas in lower Suevite, Cretaceous anhydrites and dolomites, bulk permeabilites are between 10-15 and 10-23 m2.

MTS dye based colorimetric CTLL-2 cell proliferation assay for product release and stability monitoring of interleukin-15: assay qualification, standardization and statistical analysis.

PubMed

Soman, Gopalan; Yang, Xiaoyi; Jiang, Hengguang; Giardina, Steve; Vyas, Vinay; Mitra, George; Yovandich, Jason; Creekmore, Stephen P; Waldmann, Thomas A; Quiñones, Octavio; Alvord, W Gregory

2009-08-31

A colorimetric cell proliferation assay using soluble tetrazolium salt [(CellTiter 96(R) Aqueous One Solution) cell proliferation reagent, containing the (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) and an electron coupling reagent phenazine ethosulfate], was optimized and qualified for quantitative determination of IL-15 dependent CTLL-2 cell proliferation activity. An in-house recombinant Human (rHu)IL-15 reference lot was standardized (IU/mg) against an international reference standard. Specificity of the assay for IL-15 was documented by illustrating the ability of neutralizing anti-IL-15 antibodies to block the product specific CTLL-2 cell proliferation and the lack of blocking effect with anti-IL-2 antibodies. Under the defined assay conditions, the linear dose-response concentration range was between 0.04 and 0.17ng/ml of the rHuIL-15 produced in-house and 0.5-3.0IU/ml for the international standard. Statistical analysis of the data was performed with the use of scripts written in the R Statistical Language and Environment utilizing a four-parameter logistic regression fit analysis procedure. The overall variation in the ED(50) values for the in-house reference standard from 55 independent estimates performed over the period of 1year was 12.3% of the average. Excellent intra-plate and within-day/inter-plate consistency was observed for all four parameter estimates in the model. Different preparations of rHuIL-15 showed excellent intra-plate consistency in the parameter estimates corresponding to the lower and upper asymptotes as well as to the 'slope' factor at the mid-point. The ED(50) values showed statistically significant differences for different lots and for control versus stressed samples. Three R-scripts improve data analysis capabilities allowing one to describe assay variations, to draw inferences between data sets from formal statistical tests, and to set up improved assay acceptance criteria based on comparability and consistency in the four parameters of the model. The assay is precise, accurate and robust and can be fully validated. Applications of the assay were established including process development support, release of the rHuIL-15 product for pre-clinical and clinical studies, and for monitoring storage stability.

Estimation of Japanese international financial assistance for HIV/AIDS control for 2003-2007: difficulties and limitations of data collection.

PubMed

Mori, Koichiro; Yonemoto, Kiyoshi; Takei, Teiji; Izazola-Licea, Jose; Gobet, Benjamin

2010-01-01

The purpose of this paper is to: (1) collect relevant data and estimate Japanese international financial assistance for HIV/AIDS control; (2) discuss the difficulties in collecting relevant data and the limitations of the collected data; and (3) conduct a comparative analysis on the estimated data with OECD and Kaiser Family Foundation aggregate data. The point is that we have comprehensively collected and estimated the data on Japanese international expenditures for HIV/AIDS control while there is no reliable data that is totally managed and published. In addition, we discuss the difficulties and limitations of data collection: unpublished data; insufficient data; inseparable data; problems of exchange rates; gaps between disbursement and commitment; and difference in year period among calendar, fiscal and organization-specific years. Furthermore, we show the risk of underestimating the Japanese international contribution to HIV/AIDS control on the basis of OECD and Kaiser data. In this respect, it is significant to comprehensively collect and estimate the data on Japanese international assistance for HIV/AIDS control. Finally, we derive the implication that it is crucial for a relevant international organization and/or individual countries to comprehensively collect and administer data for international cooperation in the development of health policies for HIV/AIDS.

Planck intermediate results: XLVI. Reduction of large-scale systematic effects in HFI polarization maps and estimation of the reionization optical depth

DOE PAGES

Aghanim, N.; Ashdown, M.; Aumont, J.; ...

2016-12-12

This study describes the identification, modelling, and removal of previously unexplained systematic effects in the polarization data of the Planck High Frequency Instrument (HFI) on large angular scales, including new mapmaking and calibration procedures, new and more complete end-to-end simulations, and a set of robust internal consistency checks on the resulting maps. These maps, at 100, 143, 217, and 353 GHz, are early versions of those that will be released in final form later in 2016. The improvements allow us to determine the cosmic reionization optical depth τ using, for the first time, the low-multipole EE data from HFI, reducingmore » significantly the central value and uncertainty, and hence the upper limit. Two different likelihood procedures are used to constrain τ from two estimators of the CMB E- and B-mode angular power spectra at 100 and 143 GHz, after debiasing the spectra from a small remaining systematic contamination. These all give fully consistent results. A further consistency test is performed using cross-correlations derived from the Low Frequency Instrument maps of the Planck 2015 data release and the new HFI data. For this purpose, end-to-end analyses of systematic effects from the two instruments are used to demonstrate the near independence of their dominant systematic error residuals. The tightest result comes from the HFI-based τ posterior distribution using the maximum likelihood power spectrum estimator from EE data only, giving a value 0.055 ± 0.009. Finally, in a companion paper these results are discussed in the context of the best-fit PlanckΛCDM cosmological model and recent models of reionization.« less

Planck intermediate results: XLVI. Reduction of large-scale systematic effects in HFI polarization maps and estimation of the reionization optical depth

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

Aghanim, N.; Ashdown, M.; Aumont, J.

This study describes the identification, modelling, and removal of previously unexplained systematic effects in the polarization data of the Planck High Frequency Instrument (HFI) on large angular scales, including new mapmaking and calibration procedures, new and more complete end-to-end simulations, and a set of robust internal consistency checks on the resulting maps. These maps, at 100, 143, 217, and 353 GHz, are early versions of those that will be released in final form later in 2016. The improvements allow us to determine the cosmic reionization optical depth τ using, for the first time, the low-multipole EE data from HFI, reducingmore » significantly the central value and uncertainty, and hence the upper limit. Two different likelihood procedures are used to constrain τ from two estimators of the CMB E- and B-mode angular power spectra at 100 and 143 GHz, after debiasing the spectra from a small remaining systematic contamination. These all give fully consistent results. A further consistency test is performed using cross-correlations derived from the Low Frequency Instrument maps of the Planck 2015 data release and the new HFI data. For this purpose, end-to-end analyses of systematic effects from the two instruments are used to demonstrate the near independence of their dominant systematic error residuals. The tightest result comes from the HFI-based τ posterior distribution using the maximum likelihood power spectrum estimator from EE data only, giving a value 0.055 ± 0.009. Finally, in a companion paper these results are discussed in the context of the best-fit PlanckΛCDM cosmological model and recent models of reionization.« less

Planck intermediate results. XLVI. Reduction of large-scale systematic effects in HFI polarization maps and estimation of the reionization optical depth

NASA Astrophysics Data System (ADS)

Planck Collaboration; Aghanim, N.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Ballardini, M.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Basak, S.; Battye, R.; Benabed, K.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Carron, J.; Challinor, A.; Chiang, H. C.; Colombo, L. P. L.; Combet, C.; Comis, B.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Di Valentino, E.; Dickinson, C.; Diego, J. M.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Fantaye, Y.; Finelli, F.; Forastieri, F.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frolov, A.; Galeotta, S.; Galli, S.; Ganga, K.; Génova-Santos, R. T.; Gerbino, M.; Ghosh, T.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Helou, G.; Henrot-Versillé, S.; Herranz, D.; Hivon, E.; Huang, Z.; Ilić, S.; Jaffe, A. H.; Jones, W. C.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Knox, L.; Krachmalnicoff, N.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Langer, M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Le Jeune, M.; Leahy, J. P.; Levrier, F.; Liguori, M.; Lilje, P. B.; López-Caniego, M.; Ma, Y.-Z.; Macías-Pérez, J. F.; Maggio, G.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Matarrese, S.; Mauri, N.; McEwen, J. D.; Meinhold, P. R.; Melchiorri, A.; Mennella, A.; Migliaccio, M.; Miville-Deschênes, M.-A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Moss, A.; Mottet, S.; Naselsky, P.; Natoli, P.; Oxborrow, C. A.; Pagano, L.; Paoletti, D.; Partridge, B.; Patanchon, G.; Patrizii, L.; Perdereau, O.; Perotto, L.; Pettorino, V.; Piacentini, F.; Plaszczynski, S.; Polastri, L.; Polenta, G.; Puget, J.-L.; Rachen, J. P.; Racine, B.; Reinecke, M.; Remazeilles, M.; Renzi, A.; Rocha, G.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Ruiz-Granados, B.; Salvati, L.; Sandri, M.; Savelainen, M.; Scott, D.; Sirri, G.; Sunyaev, R.; Suur-Uski, A.-S.; Tauber, J. A.; Tenti, M.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Trombetti, T.; Valiviita, J.; Van Tent, F.; Vibert, L.; Vielva, P.; Villa, F.; Vittorio, N.; Wandelt, B. D.; Watson, R.; Wehus, I. K.; White, M.; Zacchei, A.; Zonca, A.

2016-12-01

This paper describes the identification, modelling, and removal of previously unexplained systematic effects in the polarization data of the Planck High Frequency Instrument (HFI) on large angular scales, including new mapmaking and calibration procedures, new and more complete end-to-end simulations, and a set of robust internal consistency checks on the resulting maps. These maps, at 100, 143, 217, and 353 GHz, are early versions of those that will be released in final form later in 2016. The improvements allow us to determine the cosmic reionization optical depth τ using, for the first time, the low-multipole EE data from HFI, reducing significantly the central value and uncertainty, and hence the upper limit. Two different likelihood procedures are used to constrain τ from two estimators of the CMB E- and B-mode angular power spectra at 100 and 143 GHz, after debiasing the spectra from a small remaining systematic contamination. These all give fully consistent results. A further consistency test is performed using cross-correlations derived from the Low Frequency Instrument maps of the Planck 2015 data release and the new HFI data. For this purpose, end-to-end analyses of systematic effects from the two instruments are used to demonstrate the near independence of their dominant systematic error residuals. The tightest result comes from the HFI-based τ posterior distribution using the maximum likelihood power spectrum estimator from EE data only, giving a value 0.055 ± 0.009. In a companion paper these results are discussed in the context of the best-fit PlanckΛCDM cosmological model and recent models of reionization.

Estimation of covariate-specific time-dependent ROC curves in the presence of missing biomarkers.

PubMed

Li, Shanshan; Ning, Yang

2015-09-01

Covariate-specific time-dependent ROC curves are often used to evaluate the diagnostic accuracy of a biomarker with time-to-event outcomes, when certain covariates have an impact on the test accuracy. In many medical studies, measurements of biomarkers are subject to missingness due to high cost or limitation of technology. This article considers estimation of covariate-specific time-dependent ROC curves in the presence of missing biomarkers. To incorporate the covariate effect, we assume a proportional hazards model for the failure time given the biomarker and the covariates, and a semiparametric location model for the biomarker given the covariates. In the presence of missing biomarkers, we propose a simple weighted estimator for the ROC curves where the weights are inversely proportional to the selection probability. We also propose an augmented weighted estimator which utilizes information from the subjects with missing biomarkers. The augmented weighted estimator enjoys the double-robustness property in the sense that the estimator remains consistent if either the missing data process or the conditional distribution of the missing data given the observed data is correctly specified. We derive the large sample properties of the proposed estimators and evaluate their finite sample performance using numerical studies. The proposed approaches are illustrated using the US Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset. © 2015, The International Biometric Society.

Psychometric properties of the Alcohol Use Disorders Identification Test (AUDIT) and prevalence of alcohol use among Iranian psychiatric outpatients.

PubMed

Noorbakhsh, Simasadat; Shams, Jamal; Faghihimohamadi, Mohamadmahdi; Zahiroddin, Hanieh; Hallgren, Mats; Kallmen, Hakan

2018-01-30

Iran is a developing and Islamic country where the consumption of alcoholic beverages is banned. However, psychiatric disorders and alcohol use disorders are often co-occurring. We used the Alcohol Use Disorders Identification Test (AUDIT) to estimate the prevalence of alcohol use and examined the psychometric properties of the test among psychiatric outpatients in Teheran, Iran. AUDIT was completed by 846 consecutive (sequential) patients. Descriptive statistics, internal consistency (Cronbach alpha), confirmatory and exploratory factor analyses were used to analyze the prevalence of alcohol use, reliability and construct validity. 12% of men and 1% of women were hazardous alcohol consumers. Internal reliability of the Iranian version of AUDIT was excellent. Confirmatory factor analyses showed that the construct validity and the fit of previous factor structures (1, 2 and 3 factors) to data were not good and seemingly contradicted results from the explorative principal axis factoring, which showed that a 1-factor solution explained 77% of the co-variances. We could not reproduce the suggested factor structure of AUDIT, probably due to the skewed distribution of alcohol consumption. Only 19% of men and 3% of women scored above 0 on AUDIT. This could be explained by the fact that alcohol is illegal in Iran. In conclusion the AUDIT exhibited good internal reliability when used as a single scale. The prevalence estimates according to AUDIT were somewhat higher among psychiatric patients compared to what was reported by WHO regarding the general population.

Seismic, satellite, and site observations of internal solitary waves in the NE South China Sea.

PubMed

Tang, Qunshu; Wang, Caixia; Wang, Dongxiao; Pawlowicz, Rich

2014-06-20

Internal solitary waves (ISWs) in the NE South China Sea (SCS) are tidally generated at the Luzon Strait. Their propagation, evolution, and dissipation processes involve numerous issues still poorly understood. Here, a novel method of seismic oceanography capable of capturing oceanic finescale structures is used to study ISWs in the slope region of the NE SCS. Near-simultaneous observations of two ISWs were acquired using seismic and satellite imaging, and water column measurements. The vertical and horizontal length scales of the seismic observed ISWs are around 50 m and 1-2 km, respectively. Wave phase speeds calculated from seismic observations, satellite images, and water column data are consistent with each other. Observed waveforms and vertical velocities also correspond well with those estimated using KdV theory. These results suggest that the seismic method, a new option to oceanographers, can be further applied to resolve other important issues related to ISWs.

International Network of Passive Correlation Ranging for Orbit Determination of a Geostationary Satellite

NASA Astrophysics Data System (ADS)

Kaliuzhnyi, Mykola; Bushuev, Felix; Shulga, Oleksandr; Sybiryakova, Yevgeniya; Shakun, Leonid; Bezrukovs, Vladislavs; Moskalenko, Sergiy; Kulishenko, Vladislav; Malynovskyi, Yevgen

2016-12-01

An international network of passive correlation ranging of a geostationary telecommunication satellite is considered in the article. The network is developed by the RI "MAO". The network consists of five spatially separated stations of synchronized reception of DVB-S signals of digital satellite TV. The stations are located in Ukraine and Latvia. The time difference of arrival (TDOA) on the network stations of the DVB-S signals, radiated by the satellite, is a measured parameter. The results of TDOA estimation obtained by the network in May-August 2016 are presented in the article. Orbital parameters of the tracked satellite are determined using measured values of the TDOA and two models of satellite motion: the analytical model SGP4/SDP4 and the model of numerical integration of the equations of satellite motion. Both models are realized using the free low-level space dynamics library OREKIT (ORbit Extrapolation KIT).

An Application of the Methodology for Assessment of the Sustainability of Air Transport System

NASA Technical Reports Server (NTRS)

Janic, Milan

2003-01-01

An assessment and operationalization of the concept of sustainable air transport system is recognized as an important but complex research, operational and policy task. In the scope of the academic efforts to properly address the problem, this paper aims to assess the sustainability of air transport system. It particular, the paper describes the methodology for assessment of sustainability and its potential application. The methodology consists of the indicator systems, which relate to the air transport system operational, economic, social and environmental dimension of performance. The particular indicator systems are relevant for the particular actors such users (air travellers), air transport operators, aerospace manufacturers, local communities, governmental authorities at different levels (local, national, international), international air transport associations, pressure groups and public. In the scope of application of the methodology, the specific cases are selected to estimate the particular indicators, and thus to assess the system sustainability under given conditions.

Utility of correlation techniques in gravity and magnetic interpretation

NASA Technical Reports Server (NTRS)

Chandler, V. W.; Koski, J. S.; Braice, L. W.; Hinze, W. J.

1977-01-01

Internal correspondence uses Poisson's Theorem in a moving-window linear regression analysis between the anomalous first vertical derivative of gravity and total magnetic field reduced to the pole. The regression parameters provide critical information on source characteristics. The correlation coefficient indicates the strength of the relation between magnetics and gravity. Slope value gives delta j/delta sigma estimates of the anomalous source. The intercept furnishes information on anomaly interference. Cluster analysis consists of the classification of subsets of data into groups of similarity based on correlation of selected characteristics of the anomalies. Model studies are used to illustrate implementation and interpretation procedures of these methods, particularly internal correspondence. Analysis of the results of applying these methods to data from the midcontinent and a transcontinental profile shows they can be useful in identifying crustal provinces, providing information on horizontal and vertical variations of physical properties over province size zones, validating long wavelength anomalies, and isolating geomagnetic field removal problems.

An analysis of landing rates and separations at the Dallas/Fort Worth International Airport

NASA Technical Reports Server (NTRS)

Ballin, Mark G.; Erzberger, Heinz

1996-01-01

Advanced air traffic management systems such as the Center/TRACON Automation System (CTAS) should yield a wide range of benefits, including reduced aircraft delays and controller workload. To determine the traffic-flow benefits achievable from future terminal airspace automation, live radar information was used to perform an analysis of current aircraft landing rates and separations at the Dallas/Fort Worth International Airport. Separation statistics that result when controllers balance complex control procedural constraints in order to maintain high landing rates are presented. In addition, the analysis estimates the potential for airport capacity improvements by determining the unused landing opportunities that occur during rush traffic periods. Results suggest a large potential for improving the accuracy and consistency of spacing between arrivals on final approach, and they support earlier simulation findings that improved air traffic management would increase capacity and reduce delays.

Evaluation of internal alpha radiation exposure and subsequent infertility among a cohort of women formerly employed in the radium dial industry.

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

Schieve, L. A.; Davis, F.; Roeske, J.

1997-02-01

This study examined the effect of internal exposure to {alpha}-particle radiation on subsequent fertility among women employed in the radium dial industry prior to 1930, when appreciable amounts of radium were often ingested through the practice of pointing the paint brush with the lips. The analysis was limited to women for whom a radium body burden measurement had been obtained and who were married prior to age 45 (n=603). Internal radiation dose to the ovary was calculated based on initial intakes of radium-226 and radium-228, average ovarian mass, number and energy of {alpha} particles emitted, fraction of energy absorbed withmore » in the ovary, effective retention integrals and estimated photon irradiation. Time between marriage and pregnancy, number of pregnancies and number of live births served as surrogates for fertility. Radiation appeared to have no effect on fertility at estimated cumulative ovarian dose equivalents below 5 Sv; above this dose, however, statistically significant declines in both number of pregnancies and live births were observed. These trends persisted after multivariable adjustment for potential confounding variables and after exclusion of subjects contributing a potential classification or selection bias to the study. Additionally, the high-dose group experienced fewer live births than would have been expected based on population rates. There were no differences in time to first pregnancy between high- and low-dose groups. These results are consistent with earlier studies of {gamma}-ray exposures and suggest that exposure to high doses of radiation from internally deposited radium reduces fertility rather than inducing sterility.« less

45 CFR 265.7 - How will we determine if the State is meeting the quarterly reporting requirements?

Code of Federal Regulations, 2012 CFR

2012-10-01

... computational errors and are internally consistent (e.g., items that should add to totals do so); (3) The State... from computational errors and are internally consistent (e.g., items that should add to totals do so... from computational errors and are internally consistent (e.g., items that should add to totals do so...

Psychometrics and the neuroscience of individual differences: Internal consistency limits between-subjects effects.

PubMed

Hajcak, Greg; Meyer, Alexandria; Kotov, Roman

2017-08-01

In the clinical neuroscience literature, between-subjects differences in neural activity are presumed to reflect reliable measures-even though the psychometric properties of neural measures are almost never reported. The current article focuses on the critical importance of assessing and reporting internal consistency reliability-the homogeneity of "items" that comprise a neural "score." We demonstrate how variability in the internal consistency of neural measures limits between-subjects (i.e., individual differences) effects. To this end, we utilize error-related brain activity (i.e., the error-related negativity or ERN) in both healthy and generalized anxiety disorder (GAD) participants to demonstrate options for psychometric analyses of neural measures; we examine between-groups differences in internal consistency, between-groups effect sizes, and between-groups discriminability (i.e., ROC analyses)-all as a function of increasing items (i.e., number of trials). Overall, internal consistency should be used to inform experimental design and the choice of neural measures in individual differences research. The internal consistency of neural measures is necessary for interpreting results and guiding progress in clinical neuroscience-and should be routinely reported in all individual differences studies. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Analysis of the uncertainty associated with national fossil fuel CO2 emissions datasets for use in the global Fossil Fuel Data Assimilation System (FFDAS) and carbon budgets

NASA Astrophysics Data System (ADS)

Song, Y.; Gurney, K. R.; Rayner, P. J.; Asefi-Najafabady, S.

2012-12-01

High resolution quantification of global fossil fuel CO2 emissions has become essential in research aimed at understanding the global carbon cycle and supporting the verification of international agreements on greenhouse gas emission reductions. The Fossil Fuel Data Assimilation System (FFDAS) was used to estimate global fossil fuel carbon emissions at 0.25 degree from 1992 to 2010. FFDAS quantifies CO2 emissions based on areal population density, per capita economic activity, energy intensity and carbon intensity. A critical constraint to this system is the estimation of national-scale fossil fuel CO2 emissions disaggregated into economic sectors. Furthermore, prior uncertainty estimation is an important aspect of the FFDAS. Objective techniques to quantify uncertainty for the national emissions are essential. There are several institutional datasets that quantify national carbon emissions, including British Petroleum (BP), the International Energy Agency (IEA), the Energy Information Administration (EIA), and the Carbon Dioxide Information and Analysis Center (CDIAC). These four datasets have been "harmonized" by Jordan Macknick for inter-comparison purposes (Macknick, Carbon Management, 2011). The harmonization attempted to generate consistency among the different institutional datasets via a variety of techniques such as reclassifying into consistent emitting categories, recalculating based on consistent emission factors, and converting into consistent units. These harmonized data form the basis of our uncertainty estimation. We summarized the maximum, minimum and mean national carbon emissions for all the datasets from 1992 to 2010. We calculated key statistics highlighting the remaining differences among the harmonized datasets. We combine the span (max - min) of datasets for each country and year with the standard deviation of the national spans over time. We utilize the economic sectoral definitions from IEA to disaggregate the national total emission into specific sectors required by FFDAS. Our results indicated that although the harmonization performed by Macknick generates better agreement among datasets, significant differences remain at national total level. For example, the CO2 emission span for most countries range from 10% to 12%; BP is generally the highest of the four datasets while IEA is typically the lowest; The US and China had the highest absolute span values but lower percentage span values compared to other countries. However, the US and China make up nearly one-half of the total global absolute span quantity. The absolute span value for the summation of national differences approaches 1 GtC/year in 2007, almost one-half of the biological "missing sink". The span value is used as a potential bias in a recalculation of global and regional carbon budgets to highlight the importance of fossil fuel CO2 emissions in calculating the missing sink. We conclude that if the harmonized span represents potential bias, calculations of the missing sink through forward budget or inverse approaches may be biased by nearly a factor of two.

Benthic nutrient sources to hypereutrophic upper Klamath Lake, Oregon, USA.

PubMed

Kuwabara, James S; Topping, Brent R; Lynch, Dennis D; Carter, James L; Essaid, Hedeff I

2009-03-01

Three collecting trips were coordinated in April, May, and August 2006 to sample the water column and benthos of hypereutrophic Upper Klamath Lake (OR, USA) through the annual cyanophyte bloom of Aphanizomenon flos-aquae. A pore-water profiler was designed and fabricated to obtain the first high-resolution (centimeter-scale) estimates of the vertical concentration gradients of macro- and micronutrients for diffusive-flux determinations. A consistently positive benthic flux for soluble reactive phosphorus (SRP) was observed with solute release from the sediment, ranging between 0.4 and 6.1 mg/m(2)/d. The mass flux over an approximate 200-km(2) lake area was comparable in magnitude to riverine inputs. An additional concern related to fish toxicity was identified when dissolved ammonium also displayed consistently positive benthic fluxes of 4 to 134 mg/m(2)/d, again comparable to riverine inputs. Although phosphorus was a logical initial choice by water quality managers for the limiting nutrient when nitrogen-fixing cyanophytes dominate, initial trace-element results from the lake and major inflowing tributaries suggested that the role of iron limitation on primary productivity should be investigated. Dissolved iron became depleted in the lake water column during the course of the algal bloom, while dissolved ammonium and SRP increased. Elevated macroinvertebrate densities, at least of the order of 10(4) individuals/m(2), suggested that the diffusive-flux estimates may be significantly enhanced by bioturbation. In addition, heat-flux modeling indicated that groundwater advection of nutrients could also significantly contribute to internal nutrient loading. Accurate environmental assessments of lentic systems and reasonable expectations for point-source management require quantitative consideration of internal solute sources.

The Hermann Weyl Prize - Laudatio for Guilio Chiribella

NASA Astrophysics Data System (ADS)

del Olmo, M. A.

2011-03-01

The Hermann Weyl Prize was created in 2000 by the Standing Committee of the International Group Theory Colloquium. The purpose of the Weyl Prize is to provide recognition for young scientists (younger than 35) who have performed original work of significant scientific quality in the area of understanding physics through symmetries. The Hermann Weyl Prize consists of a certificate citing the accomplishments of the recipient, prize money of $500 and an allowance towards the attendance of the bi-annual International Group Theory Colloquium at which the award is presented. The previous winners of the award were: Edward Frenkel (2002), Nikita A Nekrasov (2004), Boyko Bakalov (2006) and Mohammad M Sheikh-Jabbari (2008). The Selection Committee of the Weyl Prize 2010 consisted of S T Ali (Concordia University), E Corrigan (Durham Univeristy), P Kulish (St Petersburg Mathematical Institute of the Russian Academy of Sciences), R Mosseri (CNRS Paris) and M A del Olmo (University of Valladolid, chairman). This committee has made the following announcement: The Weyl Prize for the year 2010 was awarded to Dr Giulio Chiribella, in recognition of his pioneering work on the application of group theoretical methods in Quantum Information Theory. In particular, for providing a general solution to the problem of optimal estimation of symmertry transformations based on the notion of quantum entanglement between representation and multiplicity spaces, for the derivation of optimal protocols for the alignment of quantum reference frames, for the characterization of extreme quantum measurements in finite dimensions, for the proof of equivalence between asymptotic cloning and state estimation and for the proof of the optimality of measure-and-reprepare for quantum learning of unitary transformations. The Laudatio of Guilio Chiribella, delivered by M A del Olmo, is included in the PDF.

Access to parks and physical activity: an eight country comparison.

PubMed

Schipperijn, Jasper; Cerin, Ester; Adams, Marc A; Reis, Rodrigo; Smith, Graham; Cain, Kelli; Christiansen, Lars B; van Dyck, Delfien; Gidlow, Christopher; Frank, Lawrence D; Mitáš, Josef; Pratt, Michael; Salvo, Deborah; Schofield, Grant; Sallis, James F

2017-10-01

Several systematic reviews have reported mixed associations between access to parks and physical activity, and suggest that this is due to inconsistencies in the study methods or differences across countries. An international study using consistent methods is needed to investigate the association between access to parks and physical activity. The International Physical Activity and Environment Network (IPEN) Adult Study is a multi-country cross-sectional study using a common design and consistent methods. Accelerometer, survey and Geographic Information Systems (GIS) data for 6,181 participants from 12 cities in 8 countries (Belgium, Brazil, Czech Republic, Denmark, Mexico, New Zealand, UK, USA) were used to estimate the strength and shape of associations of 11 measures of park access (1 perceived and 10 GIS-based measures) with accelerometer-based moderate-to-vigorous physical activity (MVPA) and four types of self-reported leisure-time physical activity. Associations were estimated using generalized additive mixed models. More parks within 1 km from participants' homes were associated with greater leisure-time physical activity and accelerometer-measured MVPA. Respondents who lived in the neighborhoods with the most parks did on average 24 minutes more MVPA per week than those living in the neighborhoods with the lowest number of parks. Perceived proximity to a park was positively associated with multiple leisure-time physical activity outcomes. Associations were homogeneous across all cities studied. Living in neighborhoods with many parks could contribute with up to 1/6 of the recommended weekly Having multiple parks nearby was the strongest positive correlate of PA. To increase comparability and validity of park access measures, we recommend that researchers, planners and policy makers use the number of parks within 1 km travel distance of homes as an objective indicator for park access in relation to physical activity.

Antisocial Personality Disorder Subscale (Chinese Version) of the Structured Clinical Interview for the DSM-IV Axis II disorders: validation study in Cantonese-speaking Hong Kong Chinese.

PubMed

Tang, D Y Y; Liu, A C Y; Leung, M H T; Siu, B W M

2013-06-01

OBJECTIVE. Antisocial personality disorder (ASPD) is a risk factor for violence and is associated with poor treatment response when it is a co-morbid condition with substance abuse. It is an under-recognised clinical entity in the local Hong Kong setting, for which there are only a few available Chinese-language diagnostic instruments. None has been tested for its psychometric properties in the Cantonese-speaking population in Hong Kong. This study therefore aimed to assess the reliability and validity of the Chinese version of the ASPD subscale of the Structured Clinical Interview for the DSM-IV Axis II Disorders (SCID-II) in Hong Kong Chinese. METHODS. This assessment tool was modified according to dialectal differences between Mainland China and Hong Kong. Inpatients in Castle Peak Hospital, Hong Kong, who were designated for priority follow-up based on their assessed propensity for violence and who fulfilled the inclusion criteria for the study, were recruited. To assess the level of agreement, best-estimate diagnosis made by a multidisciplinary team was compared with diagnostic status determined by the SCID-II ASPD subscale. The internal consistency, sensitivity, and specificity of the subscale were also calculated. RESULTS. The internal consistency of the subscale was acceptable at 0.79, whereas the test-retest reliability and inter-rater reliability showed an excellent and good agreement of 0.90 and 0.86, respectively. Best-estimate clinical diagnosis-SCID diagnosis agreement was acceptable at 0.76. The sensitivity, specificity, positive and negative predictive values were 0.91, 0.86, 0.83, and 0.93, respectively. CONCLUSION. The Chinese version of the SCID-II ASPD subscale is reliable and valid for diagnosing ASPD in a Cantonese-speaking clinical population.

Benthic nutrient sources to hypereutrophic Upper Klamath Lake, Oregon, USA

USGS Publications Warehouse

Kuwabara, J.S.; Topping, B.R.; Lynch, D.D.; Carter, J.L.; Essaid, H.I.

2009-01-01

Three collecting trips were coordinated in April, May, and August 2006 to sample the water column and benthos of hypereutrophic Upper Klamath Lake (OR, USA) through the annual cyanophyte bloom of Aphanizomenon flos-aquae. A porewater profiler was designed and fabricated to obtain the first high-resolution (centimeter-scale) estimates of the vertical, concentration gradients of macro- and micronutrients for diffusive-flux determinations. A consistently positive benthic flux for soluble reactive phosphorus (SRP) was observed with solute release from the sediment, ranging between 0.4 and 6.1 mg/m2/d. The mass flux over an approximate 200-km2 lake area was comparable in magnitude to riverine inputs. An additional concern, related to fish toxicity was identified when dissolved ammonium also displayed consistently positive benthic fluxes of 4 to 134 mg/m2/d, again, comparable to riverine inputs. Although phosphorus was a logical initial choice by water quality managers for the limiting nutrient when nitrogen-fixing cyanophytes dominate, initial trace-element results from the lake and major inflowing tributaries suggested that the role of iron limitation on primary productivity should be investigated. Dissolved iron became depleted in the lake water column during the course of the algal bloom, while dissolved ammonium and SRP increased. Elevated macroinvertebrate densities, at least of the order of 104 individuals/m2, suggested, that the diffusive-flux estimates may be significantly enhanced, by bioturbation. In addition, heat-flux modeling indicated that groundwater advection of nutrients could also significantly contribute to internal nutrient loading. Accurate environmental assessments of lentic systems and reasonable expectations for point-source management require quantitative consideration of internal solute sources ?? 2009 SETAC.

Translation, cross-cultural adaptation, and validation of the Turkish version of the Harris Hip Score.

PubMed

Çelik, Derya; Can, Canan; Aslan, Yasemin; Ceylan, Hasan Huseyin; Bilsel, Kerem; Ozdincler, Arzu Razak

2014-01-01

The Harris Hip Score (HHS) developed to assess function and pain from the perspective of patients hip pathologies. The purpose of this study was to translate and culturally adapt the HHS into Turkish, and thereby determine the reliability and validity of the translated version. The HHS was translated into Turkish in accordance with the stages recommended by Beaton. The measurement properties of the HHS were tested in 80 patients; 52 males, mean age 51 years (range 21-75 years) suffering from different hip pathologies. The test-retest reliability was tested in 58 patients; 28 males mean age, 52 years (range 30-73 years) after an interval of seven days. The Cronbach's Alpha was used to assess internal consistency and the intra-class correlation coefficient (ICC) was used to estimate the test-retest reliability. Patients were asked to answer the Oxford Hip Score (OHS), the Western Ontario and McMaster Universities Arthritis Index (WOMAC), the VAS and the Short Form-36 (SF-36) for the validity of the estimation. The Turkish version of the HHS showed sufficient internal consistency (Cronbach's alpha,0.70) and test-retest reliability (ICC = 0.91). The correlation coefficients between the HHS, the WOMAC and the OHS were 0.64 and 0.89 respectively. The highest correlations between the HHS and SF-36 were with the physical function scale (r = 0.72), and the lowest correlations were with the mental function scale (r = 0.10). We observed no floor or ceiling effects. The Turkish version of the HHS has sufficient reliability and validity to measure patient-reported outcome for Turkish-speaking individuals with a variety of hip disorders.

Evolution of Nonlinear Internal Waves in China Seas

NASA Technical Reports Server (NTRS)

Liu, Antony K.; Hsu, Ming-K.; Liang, Nai K.

1997-01-01

Synthetic Aperture Radar (SAR) images from ERS-I have been used to study the characteristics of internal waves of Taiwan in the East China Sea, and east of Hainan Island in the South China Sea. Rank-ordered packets of internal solitons propagating shoreward from the edge of the continental shelf were observed in the SAR images. Based on the assumption of a semidiurnal tidal origin, the wave speed can be estimated and is consistent with the internal wave theory. By using the SAR images and hydrographic data, internal waves of elevation have been identified in shallow water due to a thicker mixed layer as compared with the bottom layer on the continental shelf. The generation mechanism includes the influences of the tide and the Kuroshio intrusion across the continental shelf for the formations of elevation internal waves. The effects of water depth on the evolution of solitons and wave packets are modeled by nonlinear Kortweg-deVries (KdV) type equation and linked to satellite image observations. The numerical calculations of internal wave evolution on the continental shelf have been performed and compared with the SAR observations. For a case of depression waves in deep water, the solitons first disintegrate into dispersive wave trains and then evolve to a packet of elevation waves in the shallow water area after they pass through a turning point of approximately equal layer depths has been observed in the SAR image and simulated by numerical model.

26 CFR 1.6016-1 - Declarations of estimated income tax by corporations.

Code of Federal Regulations, 2011 CFR

2011-04-01

... corporations. 1.6016-1 Section 1.6016-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... of estimated income tax by corporations. (a) Requirement. For taxable years ending on or after December 31, 1955, a declaration of estimated tax shall be made by every corporation (including...

A new biodegradation prediction model specific to petroleum hydrocarbons.

PubMed

Howard, Philip; Meylan, William; Aronson, Dallas; Stiteler, William; Tunkel, Jay; Comber, Michael; Parkerton, Thomas F

2005-08-01

A new predictive model for determining quantitative primary biodegradation half-lives of individual petroleum hydrocarbons has been developed. This model uses a fragment-based approach similar to that of several other biodegradation models, such as those within the Biodegradation Probability Program (BIOWIN) estimation program. In the present study, a half-life in days is estimated using multiple linear regression against counts of 31 distinct molecular fragments. The model was developed using a data set consisting of 175 compounds with environmentally relevant experimental data that was divided into training and validation sets. The original fragments from the Ministry of International Trade and Industry BIOWIN model were used initially as structural descriptors and additional fragments were then added to better describe the ring systems found in petroleum hydrocarbons and to adjust for nonlinearity within the experimental data. The training and validation sets had r2 values of 0.91 and 0.81, respectively.

Decomposing self-estimates of intelligence: structure and sex differences across 12 nations.

PubMed

von Stumm, Sophie; Chamorro-Premuzic, Tomas; Furnham, Adrian

2009-05-01

This study examines the structure of self-estimates of intelligence (SEI) across 12 nations (Australia, Austria, Brazil, France, Iran, Israel, Malaysia, South Africa, Spain, Turkey, UK and US). Participants rated themselves on general and specific abilities from three popular models of intelligence: Gardner's multiple intelligences, Sternberg's triarchic theory of intelligence, and Goleman's emotional intelligence. The results showed that (a) laypeople across nations have similar and invariant concepts of intelligence, (b) concepts of intelligence are cross-culturally closely related to academic notions of intellectual ability and (c) sex differences in general and specific SEI favouring men are consistent across countries. Male hubris and female humility in SEI seem independent of sex differences in actual cognitive ability and national levels of masculinity-femininity. Furthermore, international mean differences in general SEI could not be attributed to discrepancies in national intelligence quotient (IQ) levels or to cultural variations.

Validation of the Adolescent Concerns Measure (ACM): evidence from exploratory and confirmatory factor analysis.

PubMed

Ang, Rebecca P; Chong, Wan Har; Huan, Vivien S; Yeo, Lay See

2007-01-01

This article reports the development and initial validation of scores obtained from the Adolescent Concerns Measure (ACM), a scale which assesses concerns of Asian adolescent students. In Study 1, findings from exploratory factor analysis using 619 adolescents suggested a 24-item scale with four correlated factors--Family Concerns (9 items), Peer Concerns (5 items), Personal Concerns (6 items), and School Concerns (4 items). Initial estimates of convergent validity for ACM scores were also reported. The four-factor structure of ACM scores derived from Study 1 was confirmed via confirmatory factor analysis in Study 2 using a two-fold cross-validation procedure with a separate sample of 811 adolescents. Support was found for both the multidimensional and hierarchical models of adolescent concerns using the ACM. Internal consistency and test-retest reliability estimates were adequate for research purposes. ACM scores show promise as a reliable and potentially valid measure of Asian adolescents' concerns.

A method for vibrational assessment of cortical bone

NASA Astrophysics Data System (ADS)

Song, Yan; Gunaratne, Gemunu H.

2006-09-01

Large bones from many anatomical locations of the human skeleton consist of an outer shaft (cortex) surrounding a highly porous internal region (trabecular bone) whose structure is reminiscent of a disordered cubic network. Age related degradation of cortical and trabecular bone takes different forms. Trabecular bone weakens primarily by loss of connectivity of the porous network, and recent studies have shown that vibrational response can be used to obtain reliable estimates for loss of its strength. In contrast, cortical bone degrades via the accumulation of long fractures and changes in the level of mineralization of the bone tissue. In this paper, we model cortical bone by an initially solid specimen with uniform density to which long fractures are introduced; we find that, as in the case of trabecular bone, vibrational assessment provides more reliable estimates of residual strength in cortical bone than is possible using measurements of density or porosity.

Technical Review of SRS Dose Reconstrruction Methods Used By CDC

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

Simpkins, Ali, A

2005-07-20

At the request of the Centers for Disease Control and Prevention (CDC), a subcontractor Advanced Technologies and Laboratories International, Inc.(ATL) issued a draft report estimating offsite dose as a result of Savannah River Site operations for the period 1954-1992 in support of Phase III of the SRS Dose Reconstruction Project. The doses reported by ATL differed than those previously estimated by Savannah River Site SRS dose modelers for a variety of reasons, but primarily because (1) ATL used different source terms, (2) ATL considered trespasser/poacher scenarios and (3) ATL did not consistently use site-specific parameters or correct usage parameters. Themore » receptors with the highest dose from atmospheric and liquid pathways were within about a factor of four greater than dose values previously reported by SRS. A complete set of technical comments have also been included.« less

Factor analysis of an instrument to measure the impact of disease on daily life.

PubMed

Pedrosa, Rafaela Batista Dos Santos; Rodrigues, Roberta Cunha Matheus; Padilha, Kátia Melissa; Gallani, Maria Cecília Bueno Jayme; Alexandre, Neusa Maria Costa

2016-01-01

to verify the structure of factors of an instrument to measure the Heart Valve Disease Impact on Daily Life (IDCV) when applied to coronary artery disease patients. the study included 153 coronary artery disease patients undergoing outpatient follow-up care. The IDCV structure of factors was initially assessed by means of confirmatory factor analysis and, subsequently, by exploratory factor analysis. The Varimax rotation method was used to estimate the main components of analysis, eigenvalues greater than one for extraction of factors, and factor loading greater than 0.40 for selection of items. Internal consistency was estimated using Cronbach's alpha coefficient. confirmatory factor analysis did not confirm the original structure of factors of the IDCV. Exploratory factor analysis showed three dimensions, which together explained 78% of the measurement variance. future studies with expansion of case selection are necessary to confirm the IDCV new structure of factors.

Quality and rigor of the concept mapping methodology: a pooled study analysis.

PubMed

Rosas, Scott R; Kane, Mary

2012-05-01

The use of concept mapping in research and evaluation has expanded dramatically over the past 20 years. Researchers in academic, organizational, and community-based settings have applied concept mapping successfully without the benefit of systematic analyses across studies to identify the features of a methodologically sound study. Quantitative characteristics and estimates of quality and rigor that may guide for future studies are lacking. To address this gap, we conducted a pooled analysis of 69 concept mapping studies to describe characteristics across study phases, generate specific indicators of validity and reliability, and examine the relationship between select study characteristics and quality indicators. Individual study characteristics and estimates were pooled and quantitatively summarized, describing the distribution, variation and parameters for each. In addition, variation in the concept mapping data collection in relation to characteristics and estimates was examined. Overall, results suggest concept mapping yields strong internal representational validity and very strong sorting and rating reliability estimates. Validity and reliability were consistently high despite variation in participation and task completion percentages across data collection modes. The implications of these findings as a practical reference to assess the quality and rigor for future concept mapping studies are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Estimating topological properties of weighted networks from limited information

NASA Astrophysics Data System (ADS)

Gabrielli, Andrea; Cimini, Giulio; Garlaschelli, Diego; Squartini, Angelo

A typical problem met when studying complex systems is the limited information available on their topology, which hinders our understanding of their structural and dynamical properties. A paramount example is provided by financial networks, whose data are privacy protected. Yet, the estimation of systemic risk strongly depends on the detailed structure of the interbank network. The resulting challenge is that of using aggregate information to statistically reconstruct a network and correctly predict its higher-order properties. Standard approaches either generate unrealistically dense networks, or fail to reproduce the observed topology by assigning homogeneous link weights. Here we develop a reconstruction method, based on statistical mechanics concepts, that exploits the empirical link density in a highly non-trivial way. Technically, our approach consists in the preliminary estimation of node degrees from empirical node strengths and link density, followed by a maximum-entropy inference based on a combination of empirical strengths and estimated degrees. Our method is successfully tested on the international trade network and the interbank money market, and represents a valuable tool for gaining insights on privacy-protected or partially accessible systems. Acknoweledgement to ``Growthcom'' ICT - EC project (Grant No: 611272) and ``Crisislab'' Italian Project.

Script-theory virtual case: A novel tool for education and research.

PubMed

Hayward, Jake; Cheung, Amandy; Velji, Alkarim; Altarejos, Jenny; Gill, Peter; Scarfe, Andrew; Lewis, Melanie

2016-11-01

Context/Setting: The script theory of diagnostic reasoning proposes that clinicians evaluate cases in the context of an "illness script," iteratively testing internal hypotheses against new information eventually reaching a diagnosis. We present a novel tool for teaching diagnostic reasoning to undergraduate medical students based on an adaptation of script theory. We developed a virtual patient case that used clinically authentic audio and video, interactive three-dimensional (3D) body images, and a simulated electronic medical record. Next, we used interactive slide bars to record respondents' likelihood estimates of diagnostic possibilities at various stages of the case. Responses were dynamically compared to data from expert clinicians and peers. Comparative frequency distributions were presented to the learner and final diagnostic likelihood estimates were analyzed. Detailed student feedback was collected. Over two academic years, 322 students participated. Student diagnostic likelihood estimates were similar year to year, but were consistently different from expert clinician estimates. Student feedback was overwhelmingly positive: students found the case was novel, innovative, clinically authentic, and a valuable learning experience. We demonstrate the successful implementation of a novel approach to teaching diagnostic reasoning. Future study may delineate reasoning processes associated with differences between novice and expert responses.

Observing Traveling Ionospheric Disturbances Caused by Tsunamis Using GPS TEC Measurements

NASA Technical Reports Server (NTRS)

Galvan, David A.; Komjathy, Attila; Hickey, Michael; Foster, James; Mannucci, Anthony J.

2010-01-01

Ground-based Global Positioning System (GPS) measurements of ionospheric Total Electron Content (TEC) show variations consistent with atmospheric internal gravity waves caused by ocean tsunamis following two recent seismic events: the American Samoa earthquake of September 29, 2009, and the Chile earthquake of February 27, 2010. Fluctuations in TEC correlated in time, space, and wave properties with these tsunamis were observed in TEC estimates processed using JPL's Global Ionospheric Mapping Software. These TEC estimates were band-pass filtered to remove ionospheric TEC variations with wavelengths and periods outside the typical range of internal gravity waves caused by tsunamis. Observable variations in TEC appear correlated with the tsunamis in certain locations, but not in others. Where variations are observed, the typical amplitude tends to be on the order of 1% of the background TEC value. Variations with amplitudes 0.1 - 0.2 TECU are observable with periods and timing affiliated with the tsunami. These observations are compared to estimates of expected tsunami-driven TEC variations produced by Embry Riddle Aeronautical University's Spectral Full Wave Model, an atmosphere-ionosphere coupling model, and found to be in good agreement in some locations, though there are cases when the model predicts an observable tsunami-driven signature and none is observed. These TEC variations are not always seen when a tsunami is present, but in these two events the regions where a strong ocean tsunami was observed did coincide with clear TEC observations, while a lack of clear TEC observations coincided with smaller tsunami amplitudes. There exists the potential to apply these detection techniques to real-time GPS TEC data, providing estimates of tsunami speed and amplitude that may be useful for early warning systems.

Risk of Lung Cancer Mortality in Nuclear Workers from Internal Exposure to Alpha Particle-emitting Radionuclides

PubMed Central

Atkinson, Will; Bérard, Philippe; Bingham, Derek; Birchall, Alan; Blanchardon, Eric; Bull, Richard; Guseva Canu, Irina; Challeton-de Vathaire, Cécile; Cockerill, Rupert; Do, Minh T.; Engels, Hilde; Figuerola, Jordi; Foster, Adrian; Holmstock, Luc; Hurtgen, Christian; Laurier, Dominique; Puncher, Matthew; Riddell, Anthony E.; Samson, Eric; Thierry-Chef, Isabelle; Tirmarche, Margot; Vrijheid, Martine; Cardis, Elisabeth

2017-01-01

Background: Carcinogenic risks of internal exposures to alpha-emitters (except radon) are poorly understood. Since exposure to alpha particles—particularly through inhalation—occurs in a range of settings, understanding consequent risks is a public health priority. We aimed to quantify dose–response relationships between lung dose from alpha-emitters and lung cancer in nuclear workers. Methods: We conducted a case–control study, nested within Belgian, French, and UK cohorts of uranium and plutonium workers. Cases were workers who died from lung cancer; one to three controls were matched to each. Lung doses from alpha-emitters were assessed using bioassay data. We estimated excess odds ratio (OR) of lung cancer per gray (Gy) of lung dose. Results: The study comprised 553 cases and 1,333 controls. Median positive total alpha lung dose was 2.42 mGy (mean: 8.13 mGy; maximum: 316 mGy); for plutonium the median was 1.27 mGy and for uranium 2.17 mGy. Excess OR/Gy (90% confidence interval)—adjusted for external radiation, socioeconomic status, and smoking—was 11 (2.6, 24) for total alpha dose, 50 (17, 106) for plutonium, and 5.3 (−1.9, 18) for uranium. Conclusions: We found strong evidence for associations between low doses from alpha-emitters and lung cancer risk. The excess OR/Gy was greater for plutonium than uranium, though confidence intervals overlap. Risk estimates were similar to those estimated previously in plutonium workers, and in uranium miners exposed to radon and its progeny. Expressed as risk/equivalent dose in sieverts (Sv), our estimates are somewhat larger than but consistent with those for atomic bomb survivors. See video abstract at, http://links.lww.com/EDE/B232. PMID:28520643

Double inverse-weighted estimation of cumulative treatment effects under nonproportional hazards and dependent censoring.

PubMed

Schaubel, Douglas E; Wei, Guanghui

2011-03-01

In medical studies of time-to-event data, nonproportional hazards and dependent censoring are very common issues when estimating the treatment effect. A traditional method for dealing with time-dependent treatment effects is to model the time-dependence parametrically. Limitations of this approach include the difficulty to verify the correctness of the specified functional form and the fact that, in the presence of a treatment effect that varies over time, investigators are usually interested in the cumulative as opposed to instantaneous treatment effect. In many applications, censoring time is not independent of event time. Therefore, we propose methods for estimating the cumulative treatment effect in the presence of nonproportional hazards and dependent censoring. Three measures are proposed, including the ratio of cumulative hazards, relative risk, and difference in restricted mean lifetime. For each measure, we propose a double inverse-weighted estimator, constructed by first using inverse probability of treatment weighting (IPTW) to balance the treatment-specific covariate distributions, then using inverse probability of censoring weighting (IPCW) to overcome the dependent censoring. The proposed estimators are shown to be consistent and asymptotically normal. We study their finite-sample properties through simulation. The proposed methods are used to compare kidney wait-list mortality by race. © 2010, The International Biometric Society.

Development and Validation of the 34-Item Disability Screening Questionnaire (DSQ-34) for Use in Low and Middle Income Countries Epidemiological and Development Surveys.

PubMed

Trani, Jean-François; Babulal, Ganesh Muneshwar; Bakhshi, Parul

2015-01-01

Although 80% of persons with disabilities live in low and middle-income countries, there is still a lack of comprehensive, cross-culturally validated tools to identify persons facing activity limitations and functioning difficulties in these settings. In absence of such a tool, disability estimates vary considerably according to the methodology used, and policies are based on unreliable estimates. The Disability Screening Questionnaire composed of 27 items (DSQ-27) was initially designed by a group of international experts in survey development and disability in Afghanistan for a national survey. Items were selected based on major domains of activity limitations and functioning difficulties linked to an impairment as defined by the International Classification of Functioning, Disability and Health. Face, content and construct validity, as well as sensitivity and specificity were examined. Based on the results obtained, the tool was subsequently refined and expanded to 34 items, tested and validated in Darfur, Sudan. Internal consistency for the total DSQ-34 using a raw and standardized Cronbach's Alpha and within each domain using a standardized Cronbach's Alpha was examined in the Asian context (India and Nepal). Exploratory factor analysis (EFA) using principal axis factoring (PAF) evaluated the lowest number of factors to account for the common variance among the questions in the screen. Test-retest reliability was determined by calculating intraclass correlation (ICC) and inter-rater reliability by calculating the kappa statistic; results were checked using Bland-Altman plots. The DSQ-34 was further tested for standard error of measurement (SEM) and for the minimum detectable change (MDC). Good internal consistency was indicated by Cronbach's Alpha of 0.83/0.82 for India and 0.76/0.78 for Nepal. We confirmed our assumption for EFA using the Kaiser-Meyer-Olkin measure of sampling well above the accepted cutoff of 0.40 for India (0.82) and Nepal (0.82). The criteria for Bartlett's test of sphericity were also met for both India (< .001) and Nepal (< .001). Estimates of reliability from the two countries reached acceptable levels of ICC of 0.75 (p<0.001) for India of 0.77 for Nepal (p<0.001) and good strength of agreement for weighted kappa (respectively 0.77 and 0.79). The SEM/MDC was 0.80/2.22 for India and 0.96/2.66 for Nepal indicating a smaller amount of measurement error in the screen. In Nepal and India, the DSQ-34 shows strong psychometric properties that indicate that it effectively discriminates between persons with and without disabilities. This instrument can be used in association with other instruments for the purpose of comparing health outcomes of persons with and without disabilities in LMICs.

[Validity and internal consistency of the Maslach Burnout Inventory in Dental Students from Cartagena, Colombia].

PubMed

Simancas-Pallares, Miguel Angel; Fortich Mesa, Natalia; González Martínez, Farith Damián

To determine the internal consistency and content validity of the Maslach Burnout Inventory-Student Survey (MBI-SS) in dental students from Cartagena, Colombia. Scale validation study in 886 dental students from Cartagena, Colombia. Factor structure was determined through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Internal consistency was measured using the Cronbach's alpha coefficient. Analyses were performed using the Stata v.13.2 for Windows (Statacorp., USA) and Mplus v.7.31 for Windows (Muthén & Muthén, USA) software. Internal consistency was α=.806. The factor structure showed three that accounted for the 56.6% of the variance. CFA revealed: χ 2 =926.036; df=85; RMSEA=.106 (90%CI, .100-.112); CFI=.947; TLI=.934. The MBI showed an adequate internal consistency and a factor structure being consistent with the original proposed structure with a poor fit, which does not reflect adequate content validity in this sample. Copyright © 2016 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Screening for depressive symptoms in adolescents at school: New validity evidences on the short form of the Reynolds Depression Scale.

PubMed

Ortuño-Sierra, Javier; Aritio-Solana, Rebeca; Inchausti, Félix; Chocarro de Luis, Edurne; Lucas Molina, Beatriz; Pérez de Albéniz, Alicia; Fonseca-Pedrero, Eduardo

2017-01-01

The main purpose of the present study was to assess the depressive symptomatology and to gather new validity evidences of the Reynolds Depression Scale-Short form (RADS-SF) in a representative sample of youths. The sample consisted of 2914 adolescents with a mean age of 15.85 years (SD = 1.68). We calculated the descriptive statistics and internal consistency of the RADS-SF scores. Also, confirmatory factor analyses (CFAs) at the item level and successive multigroup CFAs to test measurement invariance, were conducted. Latent mean differences across gender and educational level groups were estimated, and finally, we studied the sources of validity evidences with other external variables. The level of internal consistency of the RADS-SF Total score by means of Ordinal alpha was .89. Results from CFAs showed that the one-dimensional model displayed appropriate goodness of-fit indices with CFI value over .95, and RMSEA value under .08. In addition, the results support the strong measurement invariance of the RADS-SF scores across gender and age. When latent means were compared, statistically significant differences were found by gender and age. Females scored 0.347 over than males in Depression latent variable, whereas older adolescents scored 0.111 higher than the younger group. In addition, the RADS-SF score was associated with the RADS scores. The results suggest that the RADS-SF could be used as an efficient screening test to assess self-reported depressive symptoms in adolescents from the general population.

The Student Actions Coding Sheet (SACS): An instrument for illuminating the shifts toward student-centered science classrooms

NASA Astrophysics Data System (ADS)

Erdogan, Ibrahim; Campbell, Todd; Hashidah Abd-Hamid, Nor

2011-07-01

This study describes the development of an instrument to investigate the extent to which student-centered actions are occurring in science classrooms. The instrument was developed through the following five stages: (1) student action identification, (2) use of both national and international content experts to establish content validity, (3) refinement of the item pool based on reviewer comments, (4) pilot testing of the instrument, and (5) statistical reliability and item analysis leading to additional refinement and finalization of the instrument. In the field test, the instrument consisted of 26 items separated into four categories originally derived from student-centered instruction literature and used by the authors to sort student actions in previous research. The SACS was administered across 22 Grade 6-8 classrooms by 22 groups of observers, with a total of 67 SACS ratings completed. The finalized instrument was found to be internally consistent, with acceptable estimates from inter-rater intraclass correlation reliability coefficients at the p < 0.01 level. After the final stage of development, the SACS instrument consisted of 24 items separated into three categories, which aligned with the factor analysis clustering of the items. Additionally, concurrent validity of the SACS was established with the Reformed Teaching Observation Protocol. Based on the analyses completed, the SACS appears to be a useful instrument for inclusion in comprehensive assessment packages for illuminating the extent to which student-centered actions are occurring in science classrooms.

Construct validity test of evaluation tool for professional behaviors of entry-level occupational therapy students in the United States.

PubMed

Yuen, Hon K; Azuero, Andres; Lackey, Kaitlin W; Brown, Nicole S; Shrestha, Sangita

2016-01-01

This study aimed to test the construct validity of an instrument to measure student professional behaviors in entry-level occupational therapy (OT) students in the academic setting. A total of 718 students from 37 OT programs across the United States answered a self-assessment survey of professional behavior that we developed. The survey consisted of ranking 28 attributes, each on a 5-point Likert scale. A split-sample approach was used for exploratory and then confirmatory factor analysis. A three-factor solution with nine items was extracted using exploratory factor analysis [EFA] (n=430, 60%). The factors were 'Commitment to Learning' (2 items), 'Skills for Learning' (4 items), and 'Cultural Competence' (3 items). Confirmatory factor analysis (CFA) on the validation split (n=288, 40%) indicated fair fit for this three-factor model (fit indices: CFI=0.96, RMSEA=0.06, and SRMR=0.05). Internal consistency reliability estimates of each factor and the instrument ranged from 0.63 to 0.79. Results of the CFA in a separate validation dataset provided robust measures of goodness-of-fit for the three-factor solution developed in the EFA, and indicated that the three-factor model fitted the data well enough. Therefore, we can conclude that this student professional behavior evaluation instrument is a structurally validated tool to measure professional behaviors reported by entry-level OT students. The internal consistency reliability of each individual factor and the whole instrument was considered to be adequate to good.

Development of a self-report questionnaire designed for population-based surveillance of gingivitis in adolescents: assessment of content validity and reliability

PubMed Central

QUIROZ, Viviana; REINERO, Daniela; HERNÁNDEZ, Patricia; CONTRERAS, Johanna; VERNAL, Rolando; CARVAJAL, Paola

2017-01-01

Abstract The major infectious diseases in Chile encompass the periodontal diseases, with a combined prevalence that rises up to 90% of the population. Thus, the population-based surveillance of periodontal diseases plays a central role for assessing their prevalence and for planning, implementing, and evaluating preventive and control programs. Self-report questionnaires have been proposed for the surveillance of periodontal diseases in adult populations world-wide. Objective This study aimed to develop and assess the content validity and reliability of a cognitively adapted self-report questionnaire designed for surveillance of gingivitis in adolescents. Material and Methods Ten predetermined self-report questions evaluating early signs and symptoms of gingivitis were preliminary assessed by a panel of clinical experts. Eight questions were selected and cognitively tested in 20 adolescents aged 12 to 18 years from Santiago de Chile. The questionnaire was then conducted and answered by 178 Chilean adolescents. Internal consistency was measured using the Cronbach’s alpha and temporal stability was calculated using the Kappa-index. Results A reliable final self-report questionnaire consisting of 5 questions was obtained, with a total Cronbach’s alpha of 0.73 and a Kappa-index ranging from 0.41 to 0.77 between the different questions. Conclusions The proposed questionnaire is reliable, with an acceptable internal consistency and a temporal stability from moderate to substantial, and it is promising for estimating the prevalence of gingivitis in adolescents. PMID:28877279

Estimating the Growth of Internal Evidence Guiding Perceptual Decisions

ERIC Educational Resources Information Center

Ludwig, Casimir J. H.; Davies, J. Rhys

2011-01-01

Perceptual decision-making is thought to involve a gradual accrual of noisy evidence. Temporal integration of the evidence reduces the relative contribution of dynamic internal noise to the decision variable, thereby boosting its signal-to-noise ratio. We aimed to estimate the internal evidence guiding perceptual decisions over time, using a novel…

Low Vagal Tone Magnifies the Association Between Psychosocial Stress Exposure and Internalizing Psychopathology in Adolescents

PubMed Central

McLaughlin, Katie A.; Rith-Najarian, Leslie; Dirks, Melanie A.; Sheridan, Margaret A.

2014-01-01

Vagal tone is a measure of cardiovascular function that facilitates adaptive responses to environmental challenge. Low vagal tone is associated with poor emotional and attentional regulation in children and has been conceptualized as a marker of sensitivity to stress. We investigated whether the associations of a wide range of psychosocial stressors with internalizing and externalizing psychopathology were magnified in adolescents with low vagal tone. Resting heart period data were collected from a diverse community sample of adolescents (ages 13–17; N =168). Adolescents completed measures assessing internalizing and externalizing psychopathology and exposure to stressors occurring in family, peer, and community contexts. Respiratory sinus arrhythmia (RSA) was calculated from the interbeat interval time series. We estimated interactions between RSA and stress exposure in predicting internalizing and externalizing symptoms and evaluated whether interactions differed by gender. Exposure to psychosocial stressors was associated strongly with psychopathology. RSA was unrelated to internalizing or externalizing problems. Significant interactions were observed between RSA and child abuse, community violence, peer victimization, and traumatic events in predicting internalizing but not externalizing symptoms. Stressors were positively associated with internalizing symptoms in adolescents with low RSA but not in those with high RSA. Similar patterns were observed for anxiety and depression. These interactions were more consistently observed for male than female individuals. Low vagal tone is associated with internalizing psychopathology in adolescents exposed to high levels of stressors. Measurement of vagal tone in clinical settings might provide useful information about sensitivity to stress in child and adolescent clients. PMID:24156380

[Report of Internal Consistency of the Scales in Research Published in the Colombian Journal of Psychiatry].

PubMed

Campo-Arias, Adalberto

2013-03-01

Establishment of the frequency of reporting internal consistency of the scales in research published in the Colombian Journal of Psychiatry (CJP) between 2006 and 2010. A descriptive study was carried out which computes the report of internal consistency (Cronbach alpha) of scales in research published as original papers in the CJP. Validation studies were excluded. A total of 114 articles were published and 30 of them were included in the analysis. Researchers applied 67 scales for measuring some variables and Cronbach alpha of 20 (29.8%) scales was reported in the participating population. In the CJP, few published studies that apply measuring scales for variables report internal consistency in the analyzed sample. It is necessary for authors to report the internal consistency of used scales in the study population to guarantee the validity of conclusions. Copyright © 2013 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Socioeconomic inequalities in dental services utilisation in a Norwegian county: the third Nord-Trondelag Health Survey.

PubMed

Vikum, Eirik; Krokstad, Steinar; Holst, Dorthe; Westin, Steinar

2012-11-01

To assess the level of socioeconomic inequity in dental care utilisation in Norway and enable comparison with recent international comparative studies. We studied dental care utilisation among 17,136 men and 21,414 women in the third Nord-Trøndelag Health Survey (2006-08). Respondents aged 20 years and above were included in the study, and analyses were also performed within subgroups of age and gender (20-39, 40-59, and ≥60 years). Income-related horizontal inequity was estimated by means of concentration indices. Education-related inequity was estimated as relative risks. We found consistent pro-rich income inequity among men and women of all ages. The level of income inequity was highest among men and women ≥60 years, and in this group the income gradient was steepest between the poorest and the middle quintiles. Pro-educated inequity was found exclusively among men and women ≥60 years. General attendance was high (77%). The overall level of income-related inequity in dental services utilisation was low compared to other European countries as reported in two recent international studies of socioeconomic inequalities in dental care utilisation. Pro-rich and pro-educated inequity is a public health challenge mainly in the older part of the population.

Validity and reliability of the Self-Reported Physical Fitness (SRFit) survey.

PubMed

Keith, NiCole R; Clark, Daniel O; Stump, Timothy E; Miller, Douglas K; Callahan, Christopher M

2014-05-01

An accurate physical fitness survey could be useful in research and clinical care. To estimate the validity and reliability of a Self-Reported Fitness (SRFit) survey; an instrument that estimates muscular fitness, flexibility, cardiovascular endurance, BMI, and body composition (BC) in adults ≥ 40 years of age. 201 participants completed the SF-36 Physical Function Subscale, International Physical Activity Questionnaire (IPAQ), Older Adults' Desire for Physical Competence Scale (Rejeski), the SRFit survey, and the Rikli and Jones Senior Fitness Test. BC, height and weight were measured. SRFit survey items described BC, BMI, and Senior Fitness Test movements. Correlations between the Senior Fitness Test and the SRFit survey assessed concurrent validity. Cronbach's Alpha measured internal consistency within each SRFit domain. SRFit domain scores were compared with SF-36, IPAQ, and Rejeski survey scores to assess construct validity. Intraclass correlations evaluated test-retest reliability. Correlations between SRFit and the Senior Fitness Test domains ranged from 0.35 to 0.79. Cronbach's Alpha scores were .75 to .85. Correlations between SRFit and other survey scores were -0.23 to 0.72 and in the expected direction. Intraclass correlation coefficients were 0.79 to 0.93. All P-values were 0.001. Initial evaluation supports the SRFit survey's validity and reliability.

Deposition velocities and impact of physical properties on ozone removal for building materials

NASA Astrophysics Data System (ADS)

Lin, Chi-Chi; Hsu, Shu-Chen

2015-01-01

This study aims to estimate the ozone deposition velocities of eight commonly used building materials (BMs) which include calcium silicate board (CSB), green calcium silicate board (GCSB), mineral fiber ceiling (MFC), green mineral fiber ceiling (GMFC), gypsum board (GB), green gypsum board (GGB), wooden flooring (WF) and green wooden flooring (GWF). In addition, the impact of physical properties (specific surface area and total pore volume of BM) on ozone removal ability was also explored and discussed. Studies were conducted in a small-scale environmental stainless steel chamber. CSB and GCSB showed the highest ozone deposition velocities, while WF and GWF showed the lowest ozone deposition velocities among test BMs materials. All reaction probabilities were estimated to fall within the order of magnitude of 10-6. Green BMs showed lower reaction probabilities with ozone comparing with non-green BMs except for GGB. Consistent with the trends for deposition velocity, fleecy and porous materials exhibit higher reaction probabilities than smooth, non-porous surfaces. Specific surface area of BM is more closely related to ozone removal than total pore volume of BM with R2 of 0.93 vs. R2 of 0.84. Discussion of Thiele modulus for all test BMs indicates surface reactions are occurring quickly relative to internal diffusion and ozone removal is internal diffusion-limited.

Combined geometric and algebraic solutions for removal of bSSFP banding artifacts with performance comparisons.

PubMed

Hoff, Michael N; Andre, Jalal B; Xiang, Qing-San

2017-02-01

Balanced steady state free precession (bSSFP) imaging suffers from off-resonance artifacts such as signal modulation and banding. Solutions for removal of bSSFP off-resonance dependence are described and compared, and an optimal solution is proposed. An Algebraic Solution (AS) that complements a previously described Geometric Solution (GS) is derived from four phase-cycled bSSFP datasets. A composite Geometric-Algebraic Solution (GAS) is formed from a noise-variance-weighted average of the AS and GS images. Two simulations test the solutions over a range of parameters, and phantom and in vivo experiments are implemented. Image quality and performance of the GS, AS, and GAS are compared with the complex sum and a numerical parameter estimation algorithm. The parameter estimation algorithm, GS, AS, and GAS remove most banding and signal modulation in bSSFP imaging. The variable performance of the GS and AS on noisy data justifies generation of the GAS, which consistently provides the highest performance. The GAS is a robust technique for bSSFP signal demodulation that balances the regional efficacy of the GS and AS to remove banding, a feat not possible with prevalent techniques. Magn Reson Med 77:644-654, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

The test of variables of attention (TOVA): Internal consistency (Q1 vs. Q2 and Q3 vs. Q4) in children with Attention Deficit/Hyperactivity Disorder (ADHD)

USDA-ARS?s Scientific Manuscript database

The internal consistency of the Test of Variables of Attention (TOVA) was examined in a cohort of 6- to 12-year-old children (N = 63) strictly diagnosed with ADHD. The internal consistency of errors of omission (OMM), errors of commission (COM), response time (RT), and response time variability (RTV...

The Model Parameter Estimation Experiment (MOPEX): Its structure, connection to other international initiatives and future directions

USGS Publications Warehouse

Wagener, T.; Hogue, T.; Schaake, J.; Duan, Q.; Gupta, H.; Andreassian, V.; Hall, A.; Leavesley, G.

2006-01-01

The Model Parameter Estimation Experiment (MOPEX) is an international project aimed at developing enhanced techniques for the a priori estimation of parameters in hydrological models and in land surface parameterization schemes connected to atmospheric models. The MOPEX science strategy involves: database creation, a priori parameter estimation methodology development, parameter refinement or calibration, and the demonstration of parameter transferability. A comprehensive MOPEX database has been developed that contains historical hydrometeorological data and land surface characteristics data for many hydrological basins in the United States (US) and in other countries. This database is being continuously expanded to include basins from various hydroclimatic regimes throughout the world. MOPEX research has largely been driven by a series of international workshops that have brought interested hydrologists and land surface modellers together to exchange knowledge and experience in developing and applying parameter estimation techniques. With its focus on parameter estimation, MOPEX plays an important role in the international context of other initiatives such as GEWEX, HEPEX, PUB and PILPS. This paper outlines the MOPEX initiative, discusses its role in the scientific community, and briefly states future directions.

Force feedback delay affects perception of stiffness but not action, and the effect depends on the hand used but not on the handedness.

PubMed

Leib, Raz; Rubin, Inbar; Nisky, Ilana

2018-05-16

Interaction with an object often requires the estimation of its mechanical properties. We examined whether the hand that is used to interact with the object and their handedness affected people's estimation of these properties using stiffness estimation as a test case. We recorded participants' responses on a stiffness discrimination of a virtual elastic force field and the grip force applied on the robotic device during the interaction. In half of the trials, the robotic device delayed the participants' force feedback. Consistent with previous studies, delayed force feedback biased the perceived stiffness of the force field. Interestingly, in both left-handed and right-handed participants, for the delayed force field, there was even less perceived stiffness when participants used their left hand than their right hand. This result supports the idea that haptic processing is affected by laterality in the brain, not by handedness. Consistent with previous studies, participants adjusted their applied grip force according to the correct size and timing of the load force regardless of the hand that was used, the handedness, or the delay. This suggests that in all these conditions, participants were able to form an accurate internal representation of the anticipated trajectory of the load force (size and timing) and that this representation was used for accurate control of grip force independently of the perceptual bias. Thus, these results provide additional evidence for the dissociation between action and perception in the processing of delayed information.

Expanding the Reach of Participatory Risk Management: Testing an Online Decision-Aiding Framework for Informing Internally Consistent Choices.

PubMed

Bessette, Douglas L; Campbell-Arvai, Victoria; Arvai, Joseph

2016-05-01

This article presents research aimed at developing and testing an online, multistakeholder decision-aiding framework for informing multiattribute risk management choices associated with energy development and climate change. The framework was designed to provide necessary background information and facilitate internally consistent choices, or choices that are in line with users' prioritized objectives. In order to test different components of the decision-aiding framework, a six-part, 2 × 2 × 2 factorial experiment was conducted, yielding eight treatment scenarios. The three factors included: (1) whether or not users could construct their own alternatives; (2) the level of detail regarding the composition of alternatives users would evaluate; and (3) the way in which a final choice between users' own constructed (or highest-ranked) portfolio and an internally consistent portfolio was presented. Participants' self-reports revealed the framework was easy to use and providing an opportunity to develop one's own risk-management alternatives (Factor 1) led to the highest knowledge gains. Empirical measures showed the internal consistency of users' decisions across all treatments to be lower than expected and confirmed that providing information about alternatives' composition (Factor 2) resulted in the least internally consistent choices. At the same time, those users who did not develop their own alternatives and were not shown detailed information about the composition of alternatives believed their choices to be the most internally consistent. These results raise concerns about how the amount of information provided and the ability to construct alternatives may inversely affect users' real and perceived internal consistency. © 2015 Society for Risk Analysis.

The premature ejaculation diagnostic tool (PEDT): linguistic validity of the Chinese version.

PubMed

Huang, Yan-Ping; Chen, Bin; Ping, Ping; Wang, Hong-Xiang; Hu, Kai; Zhang, Tao; Yang, Hao; Jin, Yan; Yang, Qi; Huang, Yi-Ran

2014-09-01

The premature ejaculation diagnostic tool (PEDT) was developed to standardize the diagnosis of PE and has been applied in many countries. However, a linguistic validation of the Chinese version of PEDT does not exist. This study aims to undertake the Chinese validation of the PEDT and to evaluate its association with self-estimated intravaginal ejaculatory latency time (IELT) and clinical expert diagnosis of PE. A Chinese version of PEDT was confirmed by andrologist and bilingual linguist. Participants were recruited among seven different communities of Shanghai from 2011 to 2012, and their information regarding self-reported PE, self-estimated IELT, expert diagnosis of PE, and PEDT scores were collected. Validity of the PEDT and its association with clinical expert diagnosis of PE and self-estimated IELT were analyzed. A total of 143 patients without PE (mean age 55.11 ± 7.65 years) and 100 men with PE (mean age 53.07 ± 8.08 years) were enrolled for validation. Of the patients in PE group, the number of men reporting self-estimated IELTs of ≤1, 1-2, and >2 minutes were 34 (34.0%), 22 (22.0%), and 44 (44.0%), respectively. The Cronbach's alpha score (α = 0.77) showed adequate internal consistency, and the test-retest correlation coefficients of each item (r ≥ 0.70, P < 0.001) indicated excellent stability over time. The frequency of agreement showed that there was excellent concordance between PEDT diagnosis and clinician diagnosis when the PEDT scores ≥11. An adequate correlation was found between total PEDT score and self-estimated IELT (ρ = -0.396, P < 0.001), and sensitivity and specificity analyses suggested a score of ≤8 indicated no time-defined PE (self-estimated IELT ≤1 minute). The Chinese version of PEDT is valid in screening the presence of PE among Chinese men. The PEDT showed an adequate negative correlation with self-estimated IELT and an excellent concordance with clinician diagnosis of PE. © 2014 International Society for Sexual Medicine.

Analysis of EPR and FISH studies of radiation doses in persons who lived in the upper reaches of the Techa River.

PubMed

Degteva, M O; Shagina, N B; Shishkina, E A; Vozilova, A V; Volchkova, A Y; Vorobiova, M I; Wieser, A; Fattibene, P; Della Monaca, S; Ainsbury, E; Moquet, J; Anspaugh, L R; Napier, B A

2015-11-01

Waterborne radioactive releases into the Techa River from the Mayak Production Association in Russia during 1949-1956 resulted in significant doses to about 30,000 persons who lived in downstream settlements. The residents were exposed to internal and external radiation. Two methods for reconstruction of the external dose are considered in this paper, electron paramagnetic resonance (EPR) measurements of teeth, and fluorescence in situ hybridization (FISH) measurements of chromosome translocations in circulating lymphocytes. The main issue in the application of the EPR and FISH methods for reconstruction of the external dose for the Techa Riverside residents was strontium radioisotopes incorporated in teeth and bones that act as a source of confounding local exposures. In order to estimate and subtract doses from incorporated (89,90)Sr, the EPR and FISH assays were supported by measurements of (90)Sr-body burdens and estimates of (90)Sr concentrations in dental tissues by the luminescence method. The resulting dose estimates derived from EPR to FISH measurements for residents of the upper Techa River were found to be consistent: The mean values vary from 510 to 550 mGy for the villages located close to the site of radioactive release to 130-160 mGy for the more distant villages. The upper bound of individual estimates for both methods is equal to 2.2-2.3 Gy. The EPR- and FISH-based dose estimates were compared with the doses calculated for the donors using the most recent Techa River Dosimetry System (TRDS). The TRDS external dose assessments are based on the data on contamination of the Techa River floodplain, simulation of air kerma above the contaminated soil, age-dependent lifestyles and individual residence histories. For correct comparison, TRDS-based doses were calculated from two sources: external exposure from the contaminated environment and internal exposure from (137)Cs incorporated in donors' soft tissues. It is shown here that the TRDS-based absorbed doses in tooth enamel and muscle are in agreement with EPR- and FISH-based estimates within uncertainty bounds. Basically, this agreement between the estimates has confirmed the validity of external doses calculated with the TRDS.

Assessment of predictive performance in incomplete data by combining internal validation and multiple imputation.

PubMed

Wahl, Simone; Boulesteix, Anne-Laure; Zierer, Astrid; Thorand, Barbara; van de Wiel, Mark A

2016-10-26

Missing values are a frequent issue in human studies. In many situations, multiple imputation (MI) is an appropriate missing data handling strategy, whereby missing values are imputed multiple times, the analysis is performed in every imputed data set, and the obtained estimates are pooled. If the aim is to estimate (added) predictive performance measures, such as (change in) the area under the receiver-operating characteristic curve (AUC), internal validation strategies become desirable in order to correct for optimism. It is not fully understood how internal validation should be combined with multiple imputation. In a comprehensive simulation study and in a real data set based on blood markers as predictors for mortality, we compare three combination strategies: Val-MI, internal validation followed by MI on the training and test parts separately, MI-Val, MI on the full data set followed by internal validation, and MI(-y)-Val, MI on the full data set omitting the outcome followed by internal validation. Different validation strategies, including bootstrap und cross-validation, different (added) performance measures, and various data characteristics are considered, and the strategies are evaluated with regard to bias and mean squared error of the obtained performance estimates. In addition, we elaborate on the number of resamples and imputations to be used, and adopt a strategy for confidence interval construction to incomplete data. Internal validation is essential in order to avoid optimism, with the bootstrap 0.632+ estimate representing a reliable method to correct for optimism. While estimates obtained by MI-Val are optimistically biased, those obtained by MI(-y)-Val tend to be pessimistic in the presence of a true underlying effect. Val-MI provides largely unbiased estimates, with a slight pessimistic bias with increasing true effect size, number of covariates and decreasing sample size. In Val-MI, accuracy of the estimate is more strongly improved by increasing the number of bootstrap draws rather than the number of imputations. With a simple integrated approach, valid confidence intervals for performance estimates can be obtained. When prognostic models are developed on incomplete data, Val-MI represents a valid strategy to obtain estimates of predictive performance measures.

Probabilistic estimates of number of undiscovered deposits and their total tonnages in permissive tracts using deposit densities

USGS Publications Warehouse

Singer, Donald A.; Kouda, Ryoichi

2011-01-01

Empirical evidence indicates that processes affecting number and quantity of resources in geologic settings are very general across deposit types. Sizes of permissive tracts that geologically could contain the deposits are excellent predictors of numbers of deposits. In addition, total ore tonnage of mineral deposits of a particular type in a tract is proportional to the type’s median tonnage in a tract. Regressions using size of permissive tracts and median tonnage allow estimation of number of deposits and of total tonnage of mineralization. These powerful estimators, based on 10 different deposit types from 109 permissive worldwide control tracts, generalize across deposit types. Estimates of number of deposits and of total tonnage of mineral deposits are made by regressing permissive area, and mean (in logs) tons in deposits of the type, against number of deposits and total tonnage of deposits in the tract for the 50th percentile estimates. The regression equations (R2 = 0.91 and 0.95) can be used for all deposit types just by inserting logarithmic values of permissive area in square kilometers, and mean tons in deposits in millions of metric tons. The regression equations provide estimates at the 50th percentile, and other equations are provided for 90% confidence limits for lower estimates and 10% confidence limits for upper estimates of number of deposits and total tonnage. Equations for these percentile estimates along with expected value estimates are presented here along with comparisons with independent expert estimates. Also provided are the equations for correcting for the known well-explored deposits in a tract. These deposit-density models require internally consistent grade and tonnage models and delineations for arriving at unbiased estimates.

QSPR using MOLGEN-QSPR: the challenge of fluoroalkane boiling points.

PubMed

Rücker, Christoph; Meringer, Markus; Kerber, Adalbert

2005-01-01

By means of the new software MOLGEN-QSPR, a multilinear regression model for the boiling points of lower fluoroalkanes is established. The model is based exclusively on simple descriptors derived directly from molecular structure and nevertheless describes a broader set of data more precisely than previous attempts that used either more demanding (quantum chemical) descriptors or more demanding (nonlinear) statistical methods such as neural networks. The model's internal consistency was confirmed by leave-one-out cross-validation. The model was used to predict all unknown boiling points of fluorobutanes, and the quality of predictions was estimated by means of comparison with boiling point predictions for fluoropentanes.

Population, internal migration, and economic growth: an empirical analysis.

PubMed

Moreland, R S

1982-01-01

The role of population growth in the development process has received increasing attention during the last 15 years, as manifested in the literature in 3 broad categories. In the 1st category, the effects of rapid population growth on the growth of income have been studied with the use of simulation models, which sometimes include endogenous population growth. The 2nd category of the literature is concerned with theoretical and empirical studies of the economic determinants of various demographic rates--most usually fertility. Internal migration and dualism is the 3rd population development category to recieve attention. An attempt is made to synthesize developments in these 3 categories by estimating from a consistent set of data a 2 sector economic demographic model in which the major demographic rates are endogenous. Due to the fact that the interactions between economic and demographic variables are nonlinear and complex, the indirect effects of changes in a particular variable may depend upon the balance of numerical coefficients. For this reason it was felt that the model should be empirically grounded. A brief overview of the model is provided, and the model is compared to some similar existing models. Estimation of the model's 9 behavior equations is discussed, followed by a "base run" simulation of a developing country "stereotype" and a report of a number of policy experiments. The relatively new field of economic determinants of demographic variables was drawn upon in estimating equations to endogenize demographic phenomena that are frequently left exogenous in simulation models. The fertility and labor force participation rate functions are fairly standard, but a step beyong existing literature was taken in the life expectancy and intersectorial migration equations. On the economic side, sectoral savings functions were estimated, and it was found that the marginal propensity to save is lower in agriculture than in nonagriculture. Testing to see the effect of a population's age structure on savings rather than assuming a particular direction as Coale-Hoover and Simon do in their models, it was found that a higher proportion of children compete with savings in agriculture but complement savings in industrial areas. This was consistent with the economic value of children in agricultural and nonagricultural regions of less developed countries. The estimated production functions showed that marginal products of labor were considerably higher in agriculture than in nonagriculture. As with other simulation models, the effect of reducing fertility was to accelerate income growth. Reductions in rural fertility were more equitable and raised the overall level of per capita income more than similar efforts directed to urban areas only.

Polish adaptation of three self-report measures of job stressors: the Interpersonal Conflict at Work Scale, the Quantitative Workload Inventory and the Organizational Constraints Scale.

PubMed

Baka, Łukasz; Bazińska, Róża

2016-01-01

The objective of the present study was to test the psychometric properties, reliability and validity of three job stressor measures, namely, the Interpersonal Conflict at Work Scale, the Organizational Constraints Scale and the Quantitative Workload Inventory. The study was conducted on two samples (N = 382 and 3368) representing a wide range of occupations. The estimation of internal consistency with Cronbach's α and the test-retest method as well as both exploratory and confirmatory factor analyses were the main statistical methods. The internal consistency of the scales proved satisfactory, ranging from 0.80 to 0.90 for Cronbach's α test and from 0.72 to 0.86 for the test-retest method. The one-dimensional structure of the three measurements was confirmed. The three scales have acceptable fit to the data. The one-factor structures and other psychometric properties of the Polish version of the scales seem to be similar to those found in the US version of the scales. It was also proved that the three job stressors are positively related to all the job strain measures. The Polish versions of the three analysed scales can be used to measure the job stressors in Polish conditions.

Polish adaptation of three self-report measures of job stressors: the Interpersonal Conflict at Work Scale, the Quantitative Workload Inventory and the Organizational Constraints Scale

PubMed Central

Baka, Łukasz; Bazińska, Róża

2016-01-01

Aim. The objective of the present study was to test the psychometric properties, reliability and validity of three job stressor measures, namely, the Interpersonal Conflict at Work Scale, the Organizational Constraints Scale and the Quantitative Workload Inventory. Method. The study was conducted on two samples (N = 382 and 3368) representing a wide range of occupations. The estimation of internal consistency with Cronbach's α and the test–retest method as well as both exploratory and confirmatory factor analyses were the main statistical methods. Results. The internal consistency of the scales proved satisfactory, ranging from 0.80 to 0.90 for Cronbach's α test and from 0.72 to 0.86 for the test–retest method. The one-dimensional structure of the three measurements was confirmed. The three scales have acceptable fit to the data. The one-factor structures and other psychometric properties of the Polish version of the scales seem to be similar to those found in the US version of the scales. It was also proved that the three job stressors are positively related to all the job strain measures. Conclusions. The Polish versions of the three analysed scales can be used to measure the job stressors in Polish conditions. PMID:26652317

Psychometric Properties and Factor Structure of the German Version of the Clinician-Administered PTSD Scale for DSM-5.

PubMed

Müller-Engelmann, Meike; Schnyder, Ulrich; Dittmann, Clara; Priebe, Kathlen; Bohus, Martin; Thome, Janine; Fydrich, Thomas; Pfaltz, Monique C; Steil, Regina

2018-05-01

The Clinician-Administered PTSD Scale (CAPS) is a widely used diagnostic interview for posttraumatic stress disorder (PTSD). Following fundamental modifications in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition ( DSM-5), the CAPS had to be revised. This study examined the psychometric properties (internal consistency, interrater reliability, convergent and discriminant validity, and structural validity) of the German version of the CAPS-5 in a trauma-exposed sample ( n = 223 with PTSD; n =51 without PTSD). The results demonstrated high internal consistency (αs = .65-.93) and high interrater reliability (ICCs = .81-.89). With regard to convergent and discriminant validity, we found high correlations between the CAPS severity score and both the Posttraumatic Diagnostic Scale sum score ( r = .87) and the Beck Depression Inventory total score ( r = .72). Regarding the underlying factor structure, the hybrid model demonstrated the best fit, followed by the anhedonia model. However, we encountered some nonpositive estimates for the correlations of the latent variables (factors) for both models. The model with the best fit without methodological problems was the externalizing behaviors model, but the results also supported the DSM-5 model. Overall, the results demonstrate that the German version of the CAPS-5 is a psychometrically sound measure.

Factorial validity of an abbreviated neighborhood environment walkability scale for seniors in the Nurses' Health Study.

PubMed

Starnes, Heather A; McDonough, Meghan H; Tamura, Kosuke; James, Peter; Laden, Francine; Troped, Philip J

2014-10-10

Using validated measures of individuals' perceptions of their neighborhood built environment is important for accurately estimating effects on physical activity. However, no studies to date have examined the factorial validity of a measure of perceived neighborhood environment among older adults in the United States. The purpose of this measurement study was to test the factorial validity of a version of the Abbreviated Neighborhood Environment Walkability Scale (NEWS-A) modified for seniors in the Nurses' Health Study (NHS). A random sample of 2,920 female nurses (mean age = 73 ± 7 years) in the NHS cohort from California, Massachusetts, and Pennsylvania completed a 36-item modified NEWS-A for seniors. Confirmatory factor analyses were conducted to test measurement models for both the modified NEWS-A for seniors and the original NEWS-A. Internal consistency within factors was examined using Cronbach's alpha. The hypothesized 7-factor measurement model was a poor fit for the modified NEWS-A for seniors. Overall, the best-fitting measurement model was the original 6-factor solution to the NEWS-A. Factors were correlated and internally consistent. This study provided support for the construct validity of the original NEWS-A for assessing perceptions of neighborhood environments in older women in the United States.

Vibrotactile timing: Are vibrotactile judgements of duration affected by repetitive stimulation?

PubMed

Jones, Luke A; Ogden, Ruth S

2016-01-01

Timing in the vibrotactile modality was explored. Previous research has shown that repetitive auditory stimulation (in the form of click-trains) and visual stimulation (in the form of flickers) can alter duration judgements in a manner consistent with a "speeding up" of an internal clock. In Experiments 1 and 2 we investigated whether repetitive vibrotactile stimulation in the form of vibration trains would also alter duration judgements of either vibrotactile stimuli or visual stimuli. Participants gave verbal estimates of the duration of vibrotactile and visual stimuli that were preceded either by five seconds of 5-Hz vibration trains, or, by a five-second period of no vibrotactile stimulation, the end of which was signalled by a single vibration pulse (control condition). The results showed that durations were overestimated in the vibrotactile train conditions relative to the control condition; however, the effects were not multiplicative (did not increase with increasing stimulus duration) and as such were not consistent with a speeding up of the internal clock, but rather with an additive attentional effect. An additional finding was that the slope of the vibrotactile psychometric (control condition) function was not significantly different from that of the visual (control condition) function, which replicates a finding from a previous cross-modal comparison of timing.

Protected area types, strategies and impacts in Brazil's Amazon: public protected area strategies do not yield a consistent ranking of protected area types by impact

PubMed Central

Pfaff, Alexander; Robalino, Juan; Sandoval, Catalina; Herrera, Diego

2015-01-01

The leading policy to conserve forest is protected areas (PAs). Yet, PAs are not a single tool: land users and uses vary by PA type; and public PA strategies vary in the extent of each type and in the determinants of impact for each type, i.e. siting and internal deforestation. Further, across regions and time, strategies respond to pressures (deforestation and political). We estimate deforestation impacts of PA types for a critical frontier, the Brazilian Amazon. We separate regions and time periods that differ in their deforestation and political pressures and document considerable variation in PA strategies across regions, time periods and types. The siting of PAs varies across regions. For example, all else being equal, PAs in the arc of deforestation are relatively far from non-forest, while in other states they are relatively near. Internal deforestation varies across time periods, e.g. it is more similar across the PA types for PAs after 2000. By contrast, after 2000, PA extent is less similar across PA types with little non-indigenous area created inside the arc. PA strategies generate a range of impacts for PA types—always far higher within the arc—but not a consistent ranking of PA types by impact. PMID:26460126

Rotor internal friction instability

NASA Technical Reports Server (NTRS)

Bently, D. E.; Muszynska, A.

1985-01-01

Two aspects of internal friction affecting stability of rotating machines are discussed. The first role of internal friction consists of decreasing the level of effective damping during rotor subsynchronous and backward precessional vibrations caused by some other instability mechanisms. The second role of internal frication consists of creating rotor instability, i.e., causing self-excited subsynchronous vibrations. Experimental test results document both of these aspects.

Impact of statin adherence on cardiovascular disease and mortality outcomes: a systematic review

PubMed Central

De Vera, Mary A; Bhole, Vidula; Burns, Lindsay C; Lacaille, Diane

2014-01-01

Aims While suboptimal adherence to statin medication has been quantified in real-world patient settings, a better understanding of its impact is needed, particularly with respect to distinct problems of medication taking. Our aim was to synthesize current evidence on the impacts of statin adherence, discontinuation and persistence on cardiovascular disease and mortality outcomes. Methods We conducted a systematic review of peer-reviewed studies using a mapped search of Medline, Embase and International Pharmaceutical Abstracts databases. Observational studies that met the following criteria were included: defined patient population; statin adherence exposure; defined study outcome [i.e. cardiovascular disease (CVD), mortality]; and reporting of statin-specific results. Results Overall, 28 studies were included, with 19 studies evaluating outcomes associated with statin adherence, six with statin discontinuation and three with statin persistence. Among adherence studies, the proportion of days covered was the most widely used measure, with the majority of studies reporting increased risk of CVD (statistically significant risk estimates ranging from 1.22 to 5.26) and mortality (statistically significant risk estimates ranging from 1.25 to 2.54) among non-adherent individuals. There was greater methodological variability in discontinuation and persistence studies. However, findings of increased CVD (statistically significant risk estimates ranging from 1.22 to 1.67) and mortality (statistically significant risk estimates ranging from 1.79 to 5.00) among nonpersistent individuals were also consistently reported. Conclusions Observational studies consistently report an increased risk of adverse outcomes associated with poor statin adherence. These findings have important implications for patients and physicians and emphasize the importance of monitoring and encouraging adherence to statin therapy. PMID:25364801

INCIDENCE AND PREVALENCE OF ACROMEGALY IN THE UNITED STATES: A CLAIMS-BASED ANALYSIS.

PubMed

Broder, Michael S; Chang, Eunice; Cherepanov, Dasha; Neary, Maureen P; Ludlam, William H

2016-11-01

Acromegaly, a rare endocrine disorder, results from excessive growth hormone secretion, leading to multisystem-associated morbidities. Using 2 large nationwide databases, we estimated the annual incidence and prevalence of acromegaly in the U.S. We used 2008 to 2013 data from the Truven Health MarketScan ® Commercial Claims and Encounters Database and IMS Health PharMetrics healthcare insurance claims databases, with health plan enrollees <65 years of age. Study patients had ≥2 claims with acromegaly (International Classification of Diseases, 9th Revision, Clinical Modification Code [ICD-9CM] 253.0), or 1 claim with acromegaly and 1 claim for pituitary tumor, pituitary surgery, or cranial stereotactic radiosurgery. Annual incidence was calculated for each year from 2009 to 2013, and prevalence in 2013. Estimates were stratified by age and sex. Incidence was up to 11.7 cases per million person-years (PMPY) in MarketScan and 9.6 cases PMPY in PharMetrics. Rates were similar by sex but typically lowest in ≤17 year olds and higher in >24 year olds. The prevalence estimates were 87.8 and 71.0 per million per year in MarketScan and PharMetrics, respectively. Prevalence consistently increased with age but was similar by sex in each database. The current U.S. incidence of acromegaly may be up to 4 times higher and prevalence may be up to 50% higher than previously reported in European studies. Our findings correspond with the estimates reported by a recent U.S. study that used a single managed care database, supporting the robustness of these estimates in this population. Our study indicates there are approximately 3,000 new cases of acromegaly per year, with a prevalence of about 25,000 acromegaly patients in the U.S. CT = computed tomography GH = growth hormone IGF-1 = insulin-like growth factor 1 ICD-9-CM Code = International Classification of Diseases, 9th Revision, Clinical Modification Codes MRI = magnetic resonance imaging PMPY = per million person-years.

Next-Generation Satellite Precipitation Products for Understanding Global and Regional Water Variability

NASA Technical Reports Server (NTRS)

Hou, Arthur Y.

2011-01-01

A major challenge in understanding the space-time variability of continental water fluxes is the lack of accurate precipitation estimates over complex terrains. While satellite precipitation observations can be used to complement ground-based data to obtain improved estimates, space-based and ground-based estimates come with their own sets of uncertainties, which must be understood and characterized. Quantitative estimation of uncertainties in these products also provides a necessary foundation for merging satellite and ground-based precipitation measurements within a rigorous statistical framework. Global Precipitation Measurement (GPM) is an international satellite mission that will provide next-generation global precipitation data products for research and applications. It consists of a constellation of microwave sensors provided by NASA, JAXA, CNES, ISRO, EUMETSAT, DOD, NOAA, NPP, and JPSS. At the heart of the mission is the GPM Core Observatory provided by NASA and JAXA to be launched in 2013. The GPM Core, which will carry the first space-borne dual-frequency radar and a state-of-the-art multi-frequency radiometer, is designed to set new reference standards for precipitation measurements from space, which can then be used to unify and refine precipitation retrievals from all constellation sensors. The next-generation constellation-based satellite precipitation estimates will be characterized by intercalibrated radiometric measurements and physical-based retrievals using a common observation-derived hydrometeor database. For pre-launch algorithm development and post-launch product evaluation, NASA supports an extensive ground validation (GV) program in cooperation with domestic and international partners to improve (1) physics of remote-sensing algorithms through a series of focused field campaigns, (2) characterization of uncertainties in satellite and ground-based precipitation products over selected GV testbeds, and (3) modeling of atmospheric processes and land surface hydrology through simulation, downscaling, and data assimilation. An overview of the GPM mission, science status, and synergies with HyMex activities will be presented

A case study in electricity regulation: Theory, evidence, and policy

NASA Astrophysics Data System (ADS)

Luk, Stephen Kai Ming

This research provides a thorough empirical analysis of the problem of excess capacity found in the electricity supply industry in Hong Kong. I utilize a cost-function based temporary equilibrium framework to investigate empirically whether the current regulatory scheme encourages the two utilities to overinvest in capital, and how much consumers would have saved if the underutilized capacity is eliminated. The research is divided into two main parts. The first section attempts to find any evidence of over-investment in capital. As a point of departure from traditional analysis, I treat physical capital as quasi-fixed, which implies a restricted cost function to represent the firm's short-run cost structure. Under such specification, the firm minimizes the cost of employing variable factor inputs subject to predetermined levels of quasi-fixed factors. Using a transcendental logarithmic restricted cost function, I estimate the cost-side equivalent of marginal product of capital, or commonly referred to as "shadow values" of capital. The estimation results suggest that the two electric utilities consistently over-invest in generation capacity. The second part of this research focuses on the economies of capital utilization, and the estimation of distortion cost in capital investment. Again, I utilize a translog specification of the cost function to estimate the actual cost of the excess capacity, and to find out how much consumers could have saved if the underutilized generation capacity were brought closer to the international standard. Estimation results indicate that an increase in the utilization rate can significantly reduce the costs of both utilities. And if the current excess capacity were reduced to the international standard, the combined savings in costs for both firms will reach 4.4 billion. This amount of savings, if redistributed to all consumers evenly, will translate into a 650 rebate per capita. Finally, two policy recommendations: a more stringent policy towards capacity expansion and the creation of a reimbursement program, are discussed.

Patterns and reliability of EEG during error monitoring for internal versus external feedback in schizophrenia.

PubMed

Llerena, Katiah; Wynn, Jonathan K; Hajcak, Greg; Green, Michael F; Horan, William P

2016-07-01

Accurately monitoring one's performance on daily life tasks, and integrating internal and external performance feedback are necessary for guiding productive behavior. Although internal feedback processing, as indexed by the error-related negativity (ERN), is consistently impaired in schizophrenia, initial findings suggest that external performance feedback processing, as indexed by the feedback negativity (FN), may actually be intact. The current study evaluated internal and external feedback processing task performance and test-retest reliability in schizophrenia. 92 schizophrenia outpatients and 63 healthy controls completed a flanker task (ERN) and a time estimation task (FN). Analyses examined the ΔERN and ΔFN defined as difference waves between correct/positive versus error/negative feedback conditions. A temporal principal component analysis was conducted to distinguish the ΔERN and ΔFN from overlapping neural responses. We also assessed test-retest reliability of ΔERN and ΔFN in patients over a 4-week interval. Patients showed reduced ΔERN accompanied by intact ΔFN. In patients, test-retest reliability for both ΔERN and ΔFN over a four-week period was fair to good. Individuals with schizophrenia show a pattern of impaired internal, but intact external, feedback processing. This pattern has implications for understanding the nature and neural correlates of impaired feedback processing in schizophrenia. Published by Elsevier B.V.

UAV Annual Report, FY 1996.

DTIC Science & Technology

1996-11-06

Tracor; Vector; Cl Fiberite; Hexcel; Honeywell Cannon; Tamam; IntegriNautics; Lockheed Martin; Carlyle Gp; Northrop Grumman (SAR); Hbroux; Hughes...Aerospace; Group; Teftec Inc. Northrop Grumman ; Williams Internations Developmental estimates Developmental estimates 09 31 UAV ANNUAL REPORT UAV Tier 11...Rosemount Aerospace; Northrop Grumman ; Williams International Developmental estimates 31 UAVANNUAL REPORT A U.S. Customs Service P-3 AEW and Predator

CAREX Canada: an enhanced model for assessing occupational carcinogen exposure

PubMed Central

Peters, Cheryl E; Ge, Calvin B; Hall, Amy L; Davies, Hugh W; Demers, Paul A

2015-01-01

Objectives To estimate the numbers of workers exposed to known and suspected occupational carcinogens in Canada, building on the methods of CARcinogen EXposure (CAREX) projects in the European Union (EU). Methods CAREX Canada consists of estimates of the prevalence and level of exposure to occupational carcinogens. CAREX Canada includes occupational agents evaluated by the International Agency for Research on Cancer as known, probable or possible human carcinogens that were present and feasible to assess in Canadian workplaces. A Canadian Workplace Exposure Database was established to identify the potential for exposure in particular industries and occupations, and to create exposure level estimates among priority agents, where possible. CAREX EU data were reviewed for relevance to the Canadian context and the proportion of workers likely to be exposed by industry and occupation in Canada was assigned using expert assessment and agreement by a minimum of two occupational hygienists. These proportions were used to generate prevalence estimates by linkage with the Census of Population for 2006, and these estimates are available by industry, occupation, sex and province. Results CAREX Canada estimated the number of workers exposed to 44 known, probable and suspected carcinogens. Estimates of levels of exposure were further developed for 18 priority agents. Common exposures included night shift work (1.9 million exposed), solar ultraviolet radiation exposure (1.5 million exposed) and diesel engine exhaust (781 000 exposed). Conclusions A substantial proportion of Canadian workers are exposed to known and suspected carcinogens at work. PMID:24969047

Optimal Mass Transport for Statistical Estimation, Image Analysis, Information Geometry, and Control

DTIC Science & Technology

2017-01-10

Metric Uncertainty for Spectral Estimation based on Nevanlinna-Pick Interpolation, (with J. Karlsson) Intern. Symp. on the Math . Theory of Networks and...Systems, Melbourne 2012. 22. Geometric tools for the estimation of structured covariances, (with L. Ning, X. Jiang) Intern. Symposium on the Math . Theory...estimation and the reversibility of stochastic processes, (with Y. Chen, J. Karlsson) Proc. Int. Symp. on Math . Theory of Networks and Syst., July

Effects of control inputs on the estimation of stability and control parameters of a light airplane

NASA Technical Reports Server (NTRS)

Cannaday, R. L.; Suit, W. T.

1977-01-01

The maximum likelihood parameter estimation technique was used to determine the values of stability and control derivatives from flight test data for a low-wing, single-engine, light airplane. Several input forms were used during the tests to investigate the consistency of parameter estimates as it relates to inputs. These consistencies were compared by using the ensemble variance and estimated Cramer-Rao lower bound. In addition, the relationship between inputs and parameter correlations was investigated. Results from the stabilator inputs are inconclusive but the sequence of rudder input followed by aileron input or aileron followed by rudder gave more consistent estimates than did rudder or ailerons individually. Also, square-wave inputs appeared to provide slightly improved consistency in the parameter estimates when compared to sine-wave inputs.

DEPRESSION AND INTERNALLY DIRECTED AGGRESSION: GENETIC AND ENVIRONMENTAL CONTRIBUTIONS

PubMed Central

Haddad, Suzanne K.; Neiderhiser, Jenae M.; Spotts, Erica L.; Ganiban, Jody; Lichtenstein, Paul; Reiss, David

2013-01-01

This study uses behavior genetic (BG) methodology to investigate Freud’s theory of depression as aggression directed toward the self (1930) and the extent to which genetically and environmentally influenced aggressive tendencies contribute to depressive symptoms. Data from the Twin and Offspring Study in Sweden (TOSS) is used to demonstrate how, in estimating shared and unique environmental influences, BG methods can inform psychoanalytic theory and practice, particularly because of their shared emphasis on the importance of individual experience in development. The TOSS sample consists of 909 pairs of adult twins, their partners, and one adolescent child per couple. The Center for Epidemiologic Studies Depression Scale (Radloff 1977) was used to measure depressive symptoms and the Karolinska Scales of Personality (Schalling and Edman 1993) to measure internally directed aggression. Genetic analyses indicated that for both men and women, their unique experiences as well as genetic factors contributed equally to the association between internally directed aggression and depressive symptoms. These findings support Freud’s theory that constitutionally based differences in aggression, along with individual experiences, contribute to a person’s depressive symptoms. Establishing that an individual’s unique, not shared, experiences and perceptions contribute to depressive symptoms and internally directed aggression reinforces the use of patient-specific treatment approaches implemented in psychoanalytic psychotherapy or psychoanalysis. PMID:18515705

[Evaluation method with radiographic image quality indicator for internal defects of dental casting metallic restoration].

PubMed

Li, Y; Zheng, G; Lin, H

2014-12-18

To develop a new kind of dental radiographic image quality indicator (IQI) for internal quality of casting metallic restoration to influence on its usage life. Radiographic image quality indicator method was used to evaluate the depth of the defects region and internal quality of 127 casting metallic restoration and the accuracy was compared with that of conventional callipers method. In the 127 cases of casting metallic restoration, 9 were found the thickness less than 0.7 mm and the thinnest thickness only 0.2 mm in 26 casting metallic crowns or bridges' occlusal defects region. The data measured by image quality indicator were consistent with those measured by conventional gauging. Two metal inner crowns were found the thickness less than 0.3 mm in 56 porcelain crowns or bridges. The thickness of casting removable partial denture was more than 1.0 mm, but thinner regions were not found. It was found that in a titanium partial denture, the X-ray image of clasp was not uniform and there were internal porosity defects in the clasp. Special dental image quality indicator can solve the visual error problems caused by different observing backgrounds and estimate the depth of the defects region in the casting.

Development of an Earthquake Impact Scale

NASA Astrophysics Data System (ADS)

Wald, D. J.; Marano, K. D.; Jaiswal, K. S.

2009-12-01

With the advent of the USGS Prompt Assessment of Global Earthquakes for Response (PAGER) system, domestic (U.S.) and international earthquake responders are reconsidering their automatic alert and activation levels as well as their response procedures. To help facilitate rapid and proportionate earthquake response, we propose and describe an Earthquake Impact Scale (EIS) founded on two alerting criteria. One, based on the estimated cost of damage, is most suitable for domestic events; the other, based on estimated ranges of fatalities, is more appropriate for most global events. Simple thresholds, derived from the systematic analysis of past earthquake impact and response levels, turn out to be quite effective in communicating predicted impact and response level of an event, characterized by alerts of green (little or no impact), yellow (regional impact and response), orange (national-scale impact and response), and red (major disaster, necessitating international response). Corresponding fatality thresholds for yellow, orange, and red alert levels are 1, 100, and 1000, respectively. For damage impact, yellow, orange, and red thresholds are triggered by estimated losses exceeding 1M, 10M, and $1B, respectively. The rationale for a dual approach to earthquake alerting stems from the recognition that relatively high fatalities, injuries, and homelessness dominate in countries where vernacular building practices typically lend themselves to high collapse and casualty rates, and it is these impacts that set prioritization for international response. In contrast, it is often financial and overall societal impacts that trigger the level of response in regions or countries where prevalent earthquake resistant construction practices greatly reduce building collapse and associated fatalities. Any newly devised alert protocols, whether financial or casualty based, must be intuitive and consistent with established lexicons and procedures. In this analysis, we make an attempt at both simple and intuitive color-coded alerting criterion; yet, we preserve the necessary uncertainty measures by which one can gauge the likelihood for the alert to be over- or underestimated.

The uncertainties and causes of the recent changes in global evapotranspiration from 1982 to 2010

NASA Astrophysics Data System (ADS)

Dong, Bo; Dai, Aiguo

2017-07-01

Recent studies have shown considerable changes in terrestrial evapotranspiration (ET) since the early 1980s, but the causes of these changes remain unclear. In this study, the relative contributions of external climate forcing and internal climate variability to the recent ET changes are examined. Three datasets of global terrestrial ET and the CMIP5 multi-model ensemble mean ET are analyzed, respectively, to quantify the apparent and externally-forced ET changes, while the unforced ET variations are estimated as the apparent ET minus the forced component. Large discrepancies of the ET estimates, in terms of their trend, variability, and temperature- and precipitation-dependence, are found among the three datasets. Results show that the forced global-mean ET exhibits an upward trend of 0.08 mm day-1 century-1 from 1982 to 2010. The forced ET also contains considerable multi-year to decadal variations during the latter half of the 20th century that are caused by volcanic aerosols. The spatial patterns and interannual variations of the forced ET are more closely linked to precipitation than temperature. After removing the forced component, the global-mean ET shows a trend ranging from -0.07 to 0.06 mm day-1 century-1 during 1982-2010 with varying spatial patterns among the three datasets. Furthermore, linkages between the unforced ET and internal climate modes are examined. Variations in Pacific sea surface temperatures (SSTs) are found to be consistently correlated with ET over many land areas among the ET datasets. The results suggest that there are large uncertainties in our current estimates of global terrestrial ET for the recent decades, and the greenhouse gas (GHG) and aerosol external forcings account for a large part of the apparent trend in global-mean terrestrial ET since 1982, but Pacific SST and other internal climate variability dominate recent ET variations and changes over most regions.

137Cs exposure in the Marshallese populations: an assessment based on whole-body counting measurements (1989-1994).

PubMed

Sun, L C; Clinton, J H; Kaplan, E; Meinhold, C B

1997-07-01

The Marshall Islands were the site of numerous tests of nuclear weapons by the United States. From 1946 to 1958, nuclear devices were detonated at Enewetak and Bikini Atolls. Following the inadvertent contamination of the northern islands downwind of the 1954 Bravo Test, Brookhaven National Laboratory became involved in the medical care and the radiological safety of the affected populations. One important technique employed in assessing the internally deposited radionuclides is whole-body counting. To estimate current and future exposures to 137Cs, data from 1989 to 1994 were analyzed and are reported in this paper. During this period, 3,618 measurements were made for the Marshallese. The cesium body contents were assumed to result from a series of chronic intakes. Also, it was assumed that cesium activity in the body reaches a plateau that is maintained over 365 d. We estimated the annual effective dose rate for each population, derived from the recommendations of the International Commission on Radiological Protection. The average 137Cs uptake measured by the whole-body counting method varies from one population to another; it was consistent with measurements of external exposure rate. The analysis, though based on limited data, indicates that there is no statistical support for a seasonal effect on 137Cs uptake. The critical population group for cesium uptake is adult males. Within the 5-y monitoring period, all internal exposures to 137Cs were less than 0.2 mSv y(-1). Similarly, a persistent average cesium effective dose rate of 2 microSv y(-1) was determined for Majuro residents.

Validation of Persian rapid estimate of adult literacy in dentistry.

PubMed

Pakpour, Amir H; Lawson, Douglas M; Tadakamadla, Santosh K; Fridlund, Bengt

2016-05-01

The aim of the present study was to establish the psychometric properties of the Rapid Estimate of adult Literacy in Dentistry-99 (REALD-99) in the Persian language for use in an Iranian population (IREALD-99). A total of 421 participants with a mean age of 28 years (59% male) were included in the study. Participants included those who were 18 years or older and those residing in Quazvin (a city close to Tehran), Iran. A forward-backward translation process was used for the IREALD-99. The Test of Functional Health Literacy in Dentistry (TOFHLiD) was also administrated. The validity of the IREALD-99 was investigated by comparing the IREALD-99 across the categories of education and income levels. To further investigate, the correlation of IREALD-99 with TOFHLiD was computed. A principal component analysis (PCA) was performed on the data to assess unidimensionality and strong first factor. The Rasch mathematical model was used to evaluate the contribution of each item to the overall measure, and whether the data were invariant to differences in sex. Reliability was estimated with Cronbach's α and test-retest correlation. Cronbach's alpha for the IREALD-99 was 0.98, indicating strong internal consistency. The test-retest correlation was 0.97. IREALD-99 scores differed by education levels. IREALD-99 scores were positively related to TOFHLiD scores (rh = 0.72, P < 0.01). In addition, IREALD-99 showed positive correlation with self-rated oral health status (rh = 0.31, P < 0.01) as evidence of convergent validity. The PCA indicated a strong first component, five times the strength of the second component and nine times the third. The empirical data were a close fit with the Rasch mathematical model. There was not a significant difference in scores with respect to income level (P = 0.09), and only the very lowest income level was significantly different (P < 0.01). The IREALD-99 exhibited excellent reliability on repeated administrations, as well as internal consistency. The IREALD-99 can be used for the basic screening of oral health literacy among the Iranian population. © 2014 Wiley Publishing Asia Pty Ltd.

Test of synthetic DNA tracers in a periodic hydrodynamic system for time-variable transit time distribution assessment

NASA Astrophysics Data System (ADS)

Dahlke, H. E.; Wang, C.; McNew, C.; McLaughlin, S.; Lyon, S. W.

2016-12-01

Recent research on time-varying transport through hydrologic systems proposed using decomposed over-printed tracer breakthrough curves to directly observe transport through complex flow systems. This method, also known as the PERTH (Periodic Tracer Hierarchy) method requires periodic flow and multiple tracer injections to reveal changes in flow pathways and transport behavior. Time-variable transit time distributions (TTD) estimated from tracer breakthrough curves often vary with the storage state of the system, which in turn is influenced by internal and external variabilities, such as the arrangement of flow pathways and fluctuations in system inputs. Deciphering internal from external variabilities in TTDs might help to advance the use of TTDs for estimating the physical state of a system; however, thus far the finite number of unique conservative tracers available for tracing has limited deeper insights. Synthetic DNA tracers consisting of short strands of synthetic DNA encapsulated by polylactic acid (PLA) microspheres could potentially provide multiple unique tracers with identical transport properties needed to explore time varying transport through hydrologic systems in more detail. An experiment was conducted on the miniLeo hillslope, a 1 m3 sloping lysimeter, within the Biosphere 2 Landscape Evolution Observatory near Tucson, AZ to investigate transit time variability. The goal of the experiment was to 1) test the suitability of using synthetic DNA tracers for estimating TTDs in a hydrologic system and 2) to determine the TTDs of individual tracer pulses under periodic steady-state conditions. Five DNA tracers, consisting of four unique, encapsulated DNA sequences and one free/non-encapsulated DNA sequence, were applied as reference and probe tracers together with deuterium, using the PERTH method. The lysimeter received three 2-hour pulses of rainfall at a rate of 30 mm/hr for 10 days. Initial results show that both the encapsulated and free DNA tracers were successfully transported in a pulsed manner through the system, but had overall longer breakthrough times than the reference deuterium tracer. Comparison of the DNA probe tracers indicate differences in transit times, likely related to differences in tracer mobilization in response to the time-variant rainfall input.

JEDI International Model | Jobs and Economic Development Impact Models |

Science.gov Websites

NREL International Model JEDI International Model The Jobs and Economic Development Impacts (JEDI) International Model allows users to estimate economic development impacts from international

An Experimental Study of the Internal Consistency of Judgments Made in Bookmark Standard Setting

ERIC Educational Resources Information Center

Clauser, Brian E.; Baldwin, Peter; Margolis, Melissa J.; Mee, Janet; Winward, Marcia

2017-01-01

Validating performance standards is challenging and complex. Because of the difficulties associated with collecting evidence related to external criteria, validity arguments rely heavily on evidence related to internal criteria--especially evidence that expert judgments are internally consistent. Given its importance, it is somewhat surprising…

Sodankylä ionospheric tomography data set 2003-2014

NASA Astrophysics Data System (ADS)

Norberg, Johannes; Roininen, Lassi; Kero, Antti; Raita, Tero; Ulich, Thomas; Markkanen, Markku; Juusola, Liisa; Kauristie, Kirsti

2016-07-01

Sodankylä Geophysical Observatory has been operating a receiver network for ionospheric tomography and collecting the produced data since 2003. The collected data set consists of phase difference curves measured from COSMOS navigation satellites from the Russian Parus network (Wood and Perry, 1980) and tomographic electron density reconstructions obtained from these measurements. In this study vertical total electron content (VTEC) values are integrated from the reconstructed electron densities to make a qualitative and quantitative analysis to validate the long-term performance of the tomographic system. During the observation period, 2003-2014, there were three to five operational stations at the Fennoscandia sector. Altogether the analysis consists of around 66 000 overflights, but to ensure the quality of the reconstructions, the examination is limited to cases with descending (north to south) overflights and maximum elevation over 60°. These constraints limit the number of overflights to around 10 000. Based on this data set, one solar cycle of ionospheric VTEC estimates is constructed. The measurements are compared against the International Reference Ionosphere (IRI)-2012 model, F10.7 solar flux index and sunspot number data. Qualitatively the tomographic VTEC estimate corresponds to reference data very well, but the IRI-2012 model results are on average 40 % higher than that of the tomographic results.

Sodankylä ionospheric tomography dataset 2003-2014

NASA Astrophysics Data System (ADS)

Norberg, J.; Roininen, L.; Kero, A.; Raita, T.; Ulich, T.; Markkanen, M.; Juusola, L.; Kauristie, K.

2015-12-01

Sodankylä Geophysical Observatory has been operating a tomographic receiver network and collecting the produced data since 2003. The collected dataset consists of phase difference curves measured from Russian COSMOS dual-frequency (150/400 MHz) low-Earth-orbit satellite signals, and tomographic electron density reconstructions obtained from these measurements. In this study vertical total electron content (VTEC) values are integrated from the reconstructed electron densities to make a qualitative and quantitative analysis to validate the long-term performance of the tomographic system. During the observation period, 2003-2014, there were three-to-five operational stations at the Fenno-Scandinavian sector. Altogether the analysis consists of around 66 000 overflights, but to ensure the quality of the reconstructions, the examination is limited to cases with descending (north to south) overflights and maximum elevation over 60°. These constraints limit the number of overflights to around 10 000. Based on this dataset, one solar cycle of ionospheric vertical total electron content estimates is constructed. The measurements are compared against International Reference Ionosphere IRI-2012 model, F10.7 solar flux index and sunspot number data. Qualitatively the tomographic VTEC estimate corresponds to reference data very well, but the IRI-2012 model are on average 40 % higher of that of the tomographic results.

Dynamic estimator for determining operating conditions in an internal combustion engine

DOEpatents

Hellstrom, Erik; Stefanopoulou, Anna; Jiang, Li; Larimore, Jacob

2016-01-05

Methods and systems are provided for estimating engine performance information for a combustion cycle of an internal combustion engine. Estimated performance information for a previous combustion cycle is retrieved from memory. The estimated performance information includes an estimated value of at least one engine performance variable. Actuator settings applied to engine actuators are also received. The performance information for the current combustion cycle is then estimated based, at least in part, on the estimated performance information for the previous combustion cycle and the actuator settings applied during the previous combustion cycle. The estimated performance information for the current combustion cycle is then stored to the memory to be used in estimating performance information for a subsequent combustion cycle.

Earthquake impact scale

USGS Publications Warehouse

Wald, D.J.; Jaiswal, K.S.; Marano, K.D.; Bausch, D.

2011-01-01

With the advent of the USGS prompt assessment of global earthquakes for response (PAGER) system, which rapidly assesses earthquake impacts, U.S. and international earthquake responders are reconsidering their automatic alert and activation levels and response procedures. To help facilitate rapid and appropriate earthquake response, an Earthquake Impact Scale (EIS) is proposed on the basis of two complementary criteria. On the basis of the estimated cost of damage, one is most suitable for domestic events; the other, on the basis of estimated ranges of fatalities, is generally more appropriate for global events, particularly in developing countries. Simple thresholds, derived from the systematic analysis of past earthquake impact and associated response levels, are quite effective in communicating predicted impact and response needed after an event through alerts of green (little or no impact), yellow (regional impact and response), orange (national-scale impact and response), and red (international response). Corresponding fatality thresholds for yellow, orange, and red alert levels are 1, 100, and 1,000, respectively. For damage impact, yellow, orange, and red thresholds are triggered by estimated losses reaching $1M, $100M, and $1B, respectively. The rationale for a dual approach to earthquake alerting stems from the recognition that relatively high fatalities, injuries, and homelessness predominate in countries in which local building practices typically lend themselves to high collapse and casualty rates, and these impacts lend to prioritization for international response. In contrast, financial and overall societal impacts often trigger the level of response in regions or countries in which prevalent earthquake resistant construction practices greatly reduce building collapse and resulting fatalities. Any newly devised alert, whether economic- or casualty-based, should be intuitive and consistent with established lexicons and procedures. Useful alerts should also be both specific (although allowably uncertain) and actionable. In this analysis, an attempt is made at both simple and intuitive color-coded alerting criteria; yet the necessary uncertainty measures by which one can gauge the likelihood for the alert to be over- or underestimated are preserved. The essence of the proposed impact scale and alerting is that actionable loss information is now available in the immediate aftermath of significant earthquakes worldwide on the basis of quantifiable loss estimates. Utilizing EIS, PAGER's rapid loss estimates can adequately recommend alert levels and suggest appropriate response protocols, despite the uncertainties; demanding or awaiting observations or loss estimates with a high level of accuracy may increase the losses. ?? 2011 American Society of Civil Engineers.

Development and validation of a new population-based simulation model of osteoarthritis in New Zealand.

PubMed

Wilson, R; Abbott, J H

2018-04-01

To describe the construction and preliminary validation of a new population-based microsimulation model developed to analyse the health and economic burden and cost-effectiveness of treatments for knee osteoarthritis (OA) in New Zealand (NZ). We developed the New Zealand Management of Osteoarthritis (NZ-MOA) model, a discrete-time state-transition microsimulation model of the natural history of radiographic knee OA. In this article, we report on the model structure, derivation of input data, validation of baseline model parameters against external data sources, and validation of model outputs by comparison of the predicted population health loss with previous estimates. The NZ-MOA model simulates both the structural progression of radiographic knee OA and the stochastic development of multiple disease symptoms. Input parameters were sourced from NZ population-based data where possible, and from international sources where NZ-specific data were not available. The predicted distributions of structural OA severity and health utility detriments associated with OA were externally validated against other sources of evidence, and uncertainty resulting from key input parameters was quantified. The resulting lifetime and current population health-loss burden was consistent with estimates of previous studies. The new NZ-MOA model provides reliable estimates of the health loss associated with knee OA in the NZ population. The model structure is suitable for analysis of the effects of a range of potential treatments, and will be used in future work to evaluate the cost-effectiveness of recommended interventions within the NZ healthcare system. Copyright © 2018 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Internal Waves in the East Australian Current

NASA Astrophysics Data System (ADS)

Alford, Matthew H.; Sloyan, Bernadette M.; Simmons, Harper L.

2017-12-01

Internal waves, which drive most ocean turbulence and add "noise" to lower-frequency records, interact with low-frequency current systems and topography in yet poorly known ways. Taking advantage of a heavily instrumented, 14 month mooring array, internal waves in the East Australian Current (EAC) are examined for the first time. Internal wave horizontal kinetic energy (HKE) is within a factor of 2 of the Garrett-Munk (1976) spectrum. Continuum internal waves, near-inertial waves, and internal tides together constitute a significant percentage of the total velocity variance. Mode-1 internal tide energy fluxes are southward and much smaller than energy times group velocity, consistent with reflection at the continental slope of incident waves generated from near New Caledonia and the Solomon Islands. Internal tide HKE is highly phase variable, consistent with refraction by the variable EAC. Mode-1 near-inertial wave energy fluxes are of comparable magnitude and are equatorward and episodic, consistent with generation by storms farther poleward. These processes are considered together in the complex environment of the EAC.

Longitudinal pathways between mental health difficulties and academic performance during middle childhood and early adolescence.

PubMed

Deighton, Jessica; Humphrey, Neil; Belsky, Jay; Boehnke, Jan; Vostanis, Panos; Patalay, Praveetha

2018-03-01

There is a growing appreciation that child functioning in different domains, levels, or systems are interrelated over time. Here, we investigate links between internalizing symptoms, externalizing problems, and academic attainment during middle childhood and early adolescence, drawing on two large data sets (child: mean age 8.7 at enrolment, n = 5,878; adolescent: mean age 11.7, n = 6,388). Using a 2-year cross-lag design, we test three hypotheses - adjustment erosion, academic incompetence, and shared risk - while also examining the moderating influence of gender. Multilevel structural equation models provided consistent evidence of the deleterious effect of externalizing problems on later academic achievement in both cohorts, supporting the adjustment-erosion hypothesis. Evidence supporting the academic-incompetence hypothesis was restricted to the middle childhood cohort, revealing links between early academic failure and later internalizing symptoms. In both cohorts, inclusion of shared-risk variables improved model fit and rendered some previously established cross-lag pathways non-significant. Implications of these findings are discussed, and study strengths and limitations noted. Statement of contribution What is already known on this subject? Longitudinal research and in particular developmental cascades literature make the case for weaker associations between internalizing symptoms and academic performance than between externalizing problems and academic performance. Findings vary in terms of the magnitude and inferred direction of effects. Inconsistencies may be explained by different age ranges, prevalence of small-to-modest sample sizes, and large time lags between measurement points. Gender differences remain underexamined. What does this study add? The present study used cross-lagged models to examine longitudinal associations in age groups (middle child and adolescence) in a large-scale British sample. The large sample size not only allows for improvements on previous measurement models (e.g., allowing the analysis to account for nesting, and estimation of latent variables) but also allows for examination of gender differences. The findings clarify the role of shared-risk factors in accounting for associations between internalizing, externalizing, and academic performance, by demonstrating that shared-risk factors do not fully account for relationships between internalizing, externalizing, and academic achievement. Specifically, some pathways between mental health and academic attainment consistently remain, even after shared-risk variables have been accounted for. Findings also present consistent support for the potential impact of behavioural problems on children's academic attainment. The negative relationship between low academic attainment and subsequent internalizing symptoms for younger children is also noteworthy. © 2017 The British Psychological Society.

Applying Thiessen Polygon Catchment Areas and Gridded Population Weights to Estimate Conflict-Driven Population Changes in South Sudan

NASA Astrophysics Data System (ADS)

Jordan, L.

2017-10-01

Recent violence in South Sudan produced significant levels of conflict-driven migration undermining the accuracy and utility of both national and local level population forecasts commonly used in demographic estimates, public health metrics and food security proxies. This article explores the use of Thiessen Polygons and population grids (Gridded Population of the World, WorldPop and LandScan) as weights for estimating the catchment areas for settlement locations that serve large populations of internally displaced persons (IDP), in order to estimate the county-level in- and out-migration attributable to conflict-driven displacement between 2014-2015. Acknowledging IDP totals improves internal population estimates presented by global population databases. Unlike other forecasts, which produce spatially uniform increases in population, accounting for displaced population reveals that 15 percent of counties (n = 12) increased in population over 20 percent, and 30 percent of counties (n = 24) experienced zero or declining population growth, due to internal displacement and refugee out-migration. Adopting Thiessen Polygon catchment zones for internal migration estimation can be applied to other areas with United Nations IDP settlement data, such as Yemen, Somalia, and Nigeria.

A validation study of public health knowledge, skills, social responsibility and applied learning.

PubMed

Vackova, Dana; Chen, Coco K; Lui, Juliana N M; Johnston, Janice M

2018-06-22

To design and validate a questionnaire to measure medical students' Public Health (PH) knowledge, skills, social responsibility and applied learning as indicated in the four domains recommended by the Association of Schools & Programmes of Public Health (ASPPH). A cross-sectional study was conducted to develop an evaluation tool for PH undergraduate education through item generation, reduction, refinement and validation. The 74 preliminary items derived from the existing literature were reduced to 55 items based on expert panel review which included those with expertise in PH, psychometrics and medical education, as well as medical students. Psychometric properties of the preliminary questionnaire were assessed as follows: frequency of endorsement for item variance; principal component analysis (PCA) with varimax rotation for item reduction and factor estimation; Cronbach's Alpha, item-total correlation and test-retest validity for internal consistency and reliability. PCA yielded five factors: PH Learning Experience (6 items); PH Risk Assessment and Communication (5 items); Future Use of Evidence in Practice (6 items); Recognition of PH as a Scientific Discipline (4 items); and PH Skills Development (3 items), explaining 72.05% variance. Internal consistency and reliability tests were satisfactory (Cronbach's Alpha ranged from 0.87 to 0.90; item-total correlation > 0.59). Lower paired test-retest correlations reflected instability in a social science environment. An evaluation tool for community-centred PH education has been developed and validated. The tool measures PH knowledge, skills, social responsibilities and applied learning as recommended by the internationally recognised Association of Schools & Programmes of Public Health (ASPPH).

Development and testing of a scale to assess physician attitudes about handheld computers with decision support.

PubMed

Ray, Midge N; Houston, Thomas K; Yu, Feliciano B; Menachemi, Nir; Maisiak, Richard S; Allison, Jeroan J; Berner, Eta S

2006-01-01

The authors developed and evaluated a rating scale, the Attitudes toward Handheld Decision Support Software Scale (H-DSS), to assess physician attitudes about handheld decision support systems. The authors conducted a prospective assessment of psychometric characteristics of the H-DSS including reliability, validity, and responsiveness. Participants were 82 Internal Medicine residents. A higher score on each of the 14 five-point Likert scale items reflected a more positive attitude about handheld DSS. The H-DSS score is the mean across the fourteen items. Attitudes toward the use of the handheld DSS were assessed prior to and six months after receiving the handheld device. Cronbach's Alpha was used to assess internal consistency reliability. Pearson correlations were used to estimate and detect significant associations between scale scores and other measures (validity). Paired sample t-tests were used to test for changes in the mean attitude scale score (responsiveness) and for differences between groups. Internal consistency reliability for the scale was alpha = 0.73. In testing validity, moderate correlations were noted between the attitude scale scores and self-reported Personal Digital Assistant (PDA) usage in the hospital (correlation coefficient = 0.55) and clinic (0.48), p < 0.05 for both. The scale was responsive, in that it detected the expected increase in scores between the two administrations (3.99 (s.d. = 0.35) vs. 4.08, (s.d. = 0.34), p < 0.005). The authors' evaluation showed that the H-DSS scale was reliable, valid, and responsive. The scale can be used to guide future handheld DSS development and implementation.

Estimating Small-Body Gravity Field from Shape Model and Navigation Data

NASA Technical Reports Server (NTRS)

Park, Ryan S.; Werner, Robert A.; Bhaskaran, Shyam

2008-01-01

This paper presents a method to model the external gravity field and to estimate the internal density variation of a small-body. We first discuss the modeling problem, where we assume the polyhedral shape and internal density distribution are given, and model the body interior using finite elements definitions, such as cubes and spheres. The gravitational attractions computed from these approaches are compared with the true uniform-density polyhedral attraction and the level of accuracies are presented. We then discuss the inverse problem where we assume the body shape, radiometric measurements, and a priori density constraints are given, and estimate the internal density variation by estimating the density of each finite element. The result shows that the accuracy of the estimated density variation can be significantly improved depending on the orbit altitude, finite-element resolution, and measurement accuracy.

Empirical single sample quantification of bias and variance in Q-ball imaging.

PubMed

Hainline, Allison E; Nath, Vishwesh; Parvathaneni, Prasanna; Blaber, Justin A; Schilling, Kurt G; Anderson, Adam W; Kang, Hakmook; Landman, Bennett A

2018-02-06

The bias and variance of high angular resolution diffusion imaging methods have not been thoroughly explored in the literature and may benefit from the simulation extrapolation (SIMEX) and bootstrap techniques to estimate bias and variance of high angular resolution diffusion imaging metrics. The SIMEX approach is well established in the statistics literature and uses simulation of increasingly noisy data to extrapolate back to a hypothetical case with no noise. The bias of calculated metrics can then be computed by subtracting the SIMEX estimate from the original pointwise measurement. The SIMEX technique has been studied in the context of diffusion imaging to accurately capture the bias in fractional anisotropy measurements in DTI. Herein, we extend the application of SIMEX and bootstrap approaches to characterize bias and variance in metrics obtained from a Q-ball imaging reconstruction of high angular resolution diffusion imaging data. The results demonstrate that SIMEX and bootstrap approaches provide consistent estimates of the bias and variance of generalized fractional anisotropy, respectively. The RMSE for the generalized fractional anisotropy estimates shows a 7% decrease in white matter and an 8% decrease in gray matter when compared with the observed generalized fractional anisotropy estimates. On average, the bootstrap technique results in SD estimates that are approximately 97% of the true variation in white matter, and 86% in gray matter. Both SIMEX and bootstrap methods are flexible, estimate population characteristics based on single scans, and may be extended for bias and variance estimation on a variety of high angular resolution diffusion imaging metrics. © 2018 International Society for Magnetic Resonance in Medicine.

Attribution of global foodborne disease to specific foods: Findings from a World Health Organization structured expert elicitation.

PubMed

Hoffmann, Sandra; Devleesschauwer, Brecht; Aspinall, Willy; Cooke, Roger; Corrigan, Tim; Havelaar, Arie; Angulo, Frederick; Gibb, Herman; Kirk, Martyn; Lake, Robin; Speybroeck, Niko; Torgerson, Paul; Hald, Tine

2017-01-01

Recently the World Health Organization, Foodborne Disease Burden Epidemiology Reference Group (FERG) estimated that 31 foodborne diseases (FBDs) resulted in over 600 million illnesses and 420,000 deaths worldwide in 2010. Knowing the relative role importance of different foods as exposure routes for key hazards is critical to preventing illness. This study reports the findings of a structured expert elicitation providing globally comparable food source attribution estimates for 11 major FBDs in each of 14 world subregions. We used Cooke's Classical Model to elicit and aggregate judgments of 73 international experts. Judgments were elicited from each expert individually and aggregated using both equal and performance weights. Performance weighted results are reported as they increased the informativeness of estimates, while retaining accuracy. We report measures of central tendency and uncertainty bounds on food source attribution estimate. For some pathogens we see relatively consistent food source attribution estimates across subregions of the world; for others there is substantial regional variation. For example, for non-typhoidal salmonellosis, pork was of minor importance compared to eggs and poultry meat in the American and African subregions, whereas in the European and Western Pacific subregions the importance of these three food sources were quite similar. Our regional results broadly agree with estimates from earlier European and North American food source attribution research. As in prior food source attribution research, we find relatively wide uncertainty bounds around our median estimates. We present the first worldwide estimates of the proportion of specific foodborne diseases attributable to specific food exposure routes. While we find substantial uncertainty around central tendency estimates, we believe these estimates provide the best currently available basis on which to link FBDs and specific foods in many parts of the world, providing guidance for policy actions to control FBDs.

Estimating open population site occupancy from presence-absence data lacking the robust design.

PubMed

Dail, D; Madsen, L

2013-03-01

Many animal monitoring studies seek to estimate the proportion of a study area occupied by a target population. The study area is divided into spatially distinct sites where the detected presence or absence of the population is recorded, and this is repeated in time for multiple seasons. However, when occupied sites are detected with probability p < 1, the lack of a detection does not imply lack of occupancy. MacKenzie et al. (2003, Ecology 84, 2200-2207) developed a multiseason model for estimating seasonal site occupancy (ψt ) while accounting for unknown p. Their model performs well when observations are collected according to the robust design, where multiple sampling occasions occur during each season; the repeated sampling aids in the estimation p. However, their model does not perform as well when the robust design is lacking. In this paper, we propose an alternative likelihood model that yields improved seasonal estimates of p and Ψt in the absence of the robust design. We construct the marginal likelihood of the observed data by conditioning on, and summing out, the latent number of occupied sites during each season. A simulation study shows that in cases without the robust design, the proposed model estimates p with less bias than the MacKenzie et al. model and hence improves the estimates of Ψt . We apply both models to a data set consisting of repeated presence-absence observations of American robins (Turdus migratorius) with yearly survey periods. The two models are compared to a third estimator available when the repeated counts (from the same study) are considered, with the proposed model yielding estimates of Ψt closest to estimates from the point count model. Copyright © 2013, The International Biometric Society.

A behaviourally anchored rating scale for evaluating the use of the WHO surgical safety checklist: development and initial evaluation of the WHOBARS.

PubMed

Devcich, Daniel A; Weller, Jennifer; Mitchell, Simon J; McLaughlin, Scott; Barker, Lauren; Rudolph, Jenny W; Raemer, Daniel B; Zammert, Martin; Singer, Sara J; Torrie, Jane; Frampton, Chris Ma; Merry, Alan F

2016-10-01

Realising the full potential of the WHO Surgical Safety Checklist (SSC) to reduce perioperative harm requires the constructive engagement of all operating room (OR) team members during its administration. To facilitate research on SSC implementation, a valid and reliable instrument is needed for measuring OR team behaviours during its administration. We developed a behaviourally anchored rating scale (BARS) for this purpose. We used a modified Delphi process, involving 16 subject matter experts, to compile a BARS with behavioural domains applicable to all three phases of the SSC. We evaluated the instrument in 80 adult OR cases and 30 simulated cases using two medical student raters and seven expert raters, respectively. Intraclass correlation coefficients were calculated to assess inter-rater reliability. Internal consistency and instrument discrimination were explored. Sample size estimates for potential study designs using the instrument were calculated. The Delphi process resulted in a BARS instrument (the WHOBARS) with five behavioural domains. Intraclass correlation coefficients calculated from the OR cases exceeded 0.80 for 80% of the instrument's domains across the SSC phases. The WHOBARS showed high internal consistency across the three phases of the SSC and ability to discriminate among surgical cases in both clinical and simulated settings. Fewer than 20 cases per group would be required to show a difference of 1 point between groups in studies of the SSC, where α=0.05 and β=0.8. We have developed a generic instrument for comprehensively rating the administration of the SSC and informing initiatives to realise its full potential. We have provided data supporting its capacity for discrimination, internal consistency and inter-rater reliability. Further psychometric evaluation is warranted. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Psychometric evaluation of the Arabic version of the multidimensional assessment of fatigue scale (MAF) for use in patients with ankylosing spondylitis.

PubMed

Bahouq, Hanane; Rostom, Samira; Bahiri, Rachid; Hakkou, Jinane; Aissaoui, Nawal; Hajjaj-Hassouni, Najia

2012-12-01

Fatigue is a frequent symptom during ankylosing spondylitis (AS) often under estimated which needs to be measured properly with respect to its intensity by appropriate measures, such as the multidimensional assessment of fatigue (MAF). The aims of this study were to translate into the classic Arabic version of the MAF questionnaire and to validate its use for assessing fatigue in Moroccan patients with AS. The MAF contains 16 items with a global fatigue index (IGF). The MAF was translated and back-translated to arabic, pretested and reviewed by a committee following the Guillemin criteria (J Clin Epidemiol 46:1417-1432, 1993). It was then validate on 110 Moroccan patients with AS. Reliability for the 3-day test-retest was assessed using internal consistency by Cronbach's alpha coefficient and the intra-class correlation coefficient (ICC). External construct validity was assessed by correlation with pain, activity of disease and other keys variable. The reproducibility of the 15 items was satisfactory with a kappa statistics of agreement superior to 0.6. The ICC for IGF score reproducibility was good and reached 0.98 (IC 95%, 0.96-0.99). The internal consistency was at 0.991 with Cronbach's alpha coefficient. The construct validity showed a positive correlation between MAF and the axial (r = 0.34) and peripheral (r = 0.32) visual analogical scale, the Bath ankylosing spondylitis disease activity index (BASDAI) (r = 0.77), the first item of BASDAI (r = 0.85), the functional disability by the Bath ankylosing spondylitis functional index (r = 0.64), the erythrocyte sedimentation rate (r = 0.43) and the C reactive protein (r = 0.30) (for all P < 0.001). There was no statistical correlation between MAF and the other variables. The Arabic version of the MAF has good comprehensibility, internal consistency, reliability and validity for the evaluation of Arabic speaking patients with AS.

Reliability, Dimensionality, and Internal Consistency as Defined by Cronbach: Distinct Albeit Related Concepts

ERIC Educational Resources Information Center

Davenport, Ernest C.; Davison, Mark L.; Liou, Pey-Yan; Love, Quintin U.

2015-01-01

This article uses definitions provided by Cronbach in his seminal paper for coefficient a to show the concepts of reliability, dimensionality, and internal consistency are distinct but interrelated. The article begins with a critique of the definition of reliability and then explores mathematical properties of Cronbach's a. Internal consistency…

Estimating GFR using Serum Cystatin C Alone and in Combination with Serum Creatinine: A Pooled Analysis of 3418 Individuals with CKD

PubMed Central

Stevens, Lesley A; Coresh, Josef; Schmid, Christopher H; Feldman, Harold I.; Froissart, Marc; Kusek, John; Rossert, Jerome; Van Lente, Frederick; Bruce, Robert D.; Zhang, Yaping (Lucy); Greene, Tom; Levey, Andrew S

2008-01-01

Background Serum cystatin C (Scys) has been proposed as a potential replacement for serum creatinine (Scr) in glomerular filtration rate (GFR) estimation. We report development and evaluation of GFR estimating equations using Scys alone and Scys, Scr or both with demographic variables. Study Design Test of diagnostic accuracy. Setting and Participants Participants screened for three chronic kidney disease (CKD) studies in the US (n=2980) and a clinical population in Paris, France (n=438) Reference Test Measured GFR (mGFR). Index Test Estimated GFR using the four new equations based on Scys alone, Scys, Scr or both with age, sex and race. New equations were developed using regression with log GFR as the outcome in 2/3 data from US studies. Internal validation was performed in remaining 1/3 of data from US CKD studies; external validation was performed in the Paris study. Measurements GFR was measured using urinary clearance of 125I-iothalamate in the US studies and chromium-ethylenediaminetetraacetate (51Cr-EDTA) in the Paris study. Scys was measured by Dade Behring assay, standardized Scr. Results Mean mGFR, Scr and Scys were 48 (5th–95th percentile 15–95) ml/min/1.73m2 2.1 mg/dL and 1.8 mg/L respectively. For the new equations, the coefficients for age, sex and race were significant in the equation with Scys but 2 to 4 fold smaller than in the equation with Scr. Measures of performance among new equations were consistent across development, internal and external validation datasets. Percent of eGFR within 30% of mGFR for equations based on Scys alone, Scys, Scr or both with age, sex and race were 81, 83, 85, and 89%, respectively. The equation using Scys alone yields estimates with small biases in age, sex and race subgroups, which are improved in equations including these variables. Limitations Study population composed mainly of patients with CKD. Conclusions Scys alone provides GFR estimates that are nearly as accurate as Scr adjusted for age, sex and race thus providing an alternative GFR estimate that is not linked to muscle mass. An equation including Scys in combination with Scr, age, sex and race provide most accurate estimates. PMID:18295055

Post-Movement Beta Activity in Sensorimotor Cortex Indexes Confidence in the Estimations from Internal Models.

PubMed

Tan, Huiling; Wade, Cian; Brown, Peter

2016-02-03

Beta oscillations are a dominant feature of the sensorimotor system. A transient and prominent increase in beta oscillations is consistently observed across the sensorimotor cortical-basal ganglia network after cessation of voluntary movement: the post-movement beta synchronization (PMBS). Current theories about the function of the PMBS have been focused on either the closure of motor response or the processing of sensory afferance. Computational models of sensorimotor control have emphasized the importance of the integration between feedforward estimation and sensory feedback, and therefore the putative motor and sensory functions of beta oscillations may reciprocally interact with each other and in fact be indissociable. Here we show that the amplitude of sensorimotor PMBS is modulated by the history of visual feedback of task-relevant errors, and negatively correlated with the trial-to-trial exploratory adjustment in a sensorimotor adaptation task in young healthy human subjects. The PMBS also negatively correlated with the uncertainty associated with the feedforward estimation, which was recursively updated in light of new sensory feedback, as identified by a Bayesian learning model. These results reconcile the two opposing motor and sensory views of the function of PMBS, and suggest a unifying theory in which PMBS indexes the confidence in internal feedforward estimation in Bayesian sensorimotor integration. Its amplitude simultaneously reflects cortical sensory processing and signals the need for maintenance or adaptation of the motor output, and if necessary, exploration to identify an altered sensorimotor transformation. For optimal sensorimotor control, sensory feedback and feedforward estimation of a movement's sensory consequences should be weighted by the inverse of their corresponding uncertainties, which require recursive updating in a dynamic environment. We show that post-movement beta activity (13-30 Hz) over sensorimotor cortex in young healthy subjects indexes the evaluation of uncertainty in feedforward estimation. Our work contributes to the understanding of the function of beta oscillations in sensorimotor control, and provides further insight into how aberrant beta activity can contribute to the pathophysiology of movement disorders. Copyright © 2016 Tan et al.

Psychometric considerations in the measurement of event-related brain potentials: Guidelines for measurement and reporting.

PubMed

Clayson, Peter E; Miller, Gregory A

2017-01-01

Failing to consider psychometric issues related to reliability and validity, differential deficits, and statistical power potentially undermines the conclusions of a study. In research using event-related brain potentials (ERPs), numerous contextual factors (population sampled, task, data recording, analysis pipeline, etc.) can impact the reliability of ERP scores. The present review considers the contextual factors that influence ERP score reliability and the downstream effects that reliability has on statistical analyses. Given the context-dependent nature of ERPs, it is recommended that ERP score reliability be formally assessed on a study-by-study basis. Recommended guidelines for ERP studies include 1) reporting the threshold of acceptable reliability and reliability estimates for observed scores, 2) specifying the approach used to estimate reliability, and 3) justifying how trial-count minima were chosen. A reliability threshold for internal consistency of at least 0.70 is recommended, and a threshold of 0.80 is preferred. The review also advocates the use of generalizability theory for estimating score dependability (the generalizability theory analog to reliability) as an improvement on classical test theory reliability estimates, suggesting that the latter is less well suited to ERP research. To facilitate the calculation and reporting of dependability estimates, an open-source Matlab program, the ERP Reliability Analysis Toolbox, is presented. Copyright © 2016 Elsevier B.V. All rights reserved.

Terminator field-aligned current system: A new finding from model-assimilated data set (MADS)

NASA Astrophysics Data System (ADS)

Zhu, L.; Schunk, R. W.; Scherliess, L.; Sojka, J. J.; Gardner, L. C.; Eccles, J. V.; Rice, D.

2013-12-01

Physics-based data assimilation models have been recognized by the space science community as the most accurate approach to specify and forecast the space weather of the solar-terrestrial environment. The model-assimilated data sets (MADS) produced by these models constitute an internally consistent time series of global three-dimensional fields whose accuracy can be estimated. Because of its internal consistency of physics and completeness of descriptions on the status of global systems, the MADS has also been a powerful tool to identify the systematic errors in measurements, reveal the missing physics in physical models, and discover the important dynamical physical processes that are inadequately observed or missed by measurements due to observational limitations. In the past years, we developed a data assimilation model for the high-latitude ionospheric plasma dynamics and electrodynamics. With a set of physical models, an ensemble Kalman filter, and the ingestion of data from multiple observations, the data assimilation model can produce a self-consistent time-series of the complete descriptions of the global high-latitude ionosphere, which includes the convection electric field, horizontal and field-aligned currents, conductivity, as well as 3-D plasma densities and temperatures, In this presentation, we will show a new field-aligned current system discovered from the analysis of the MADS produced by our data assimilation model. This new current system appears and develops near the ionospheric terminator. The dynamical features of this current system will be described and its connection to the active role of the ionosphere in the M-I coupling will be discussed.

Estimating topological properties of weighted networks from limited information.

PubMed

Cimini, Giulio; Squartini, Tiziano; Gabrielli, Andrea; Garlaschelli, Diego

2015-10-01

A problem typically encountered when studying complex systems is the limitedness of the information available on their topology, which hinders our understanding of their structure and of the dynamical processes taking place on them. A paramount example is provided by financial networks, whose data are privacy protected: Banks publicly disclose only their aggregate exposure towards other banks, keeping individual exposures towards each single bank secret. Yet, the estimation of systemic risk strongly depends on the detailed structure of the interbank network. The resulting challenge is that of using aggregate information to statistically reconstruct a network and correctly predict its higher-order properties. Standard approaches either generate unrealistically dense networks, or fail to reproduce the observed topology by assigning homogeneous link weights. Here, we develop a reconstruction method, based on statistical mechanics concepts, that makes use of the empirical link density in a highly nontrivial way. Technically, our approach consists in the preliminary estimation of node degrees from empirical node strengths and link density, followed by a maximum-entropy inference based on a combination of empirical strengths and estimated degrees. Our method is successfully tested on the international trade network and the interbank money market, and represents a valuable tool for gaining insights on privacy-protected or partially accessible systems.

Estimating topological properties of weighted networks from limited information

NASA Astrophysics Data System (ADS)

Cimini, Giulio; Squartini, Tiziano; Gabrielli, Andrea; Garlaschelli, Diego

2015-10-01

A problem typically encountered when studying complex systems is the limitedness of the information available on their topology, which hinders our understanding of their structure and of the dynamical processes taking place on them. A paramount example is provided by financial networks, whose data are privacy protected: Banks publicly disclose only their aggregate exposure towards other banks, keeping individual exposures towards each single bank secret. Yet, the estimation of systemic risk strongly depends on the detailed structure of the interbank network. The resulting challenge is that of using aggregate information to statistically reconstruct a network and correctly predict its higher-order properties. Standard approaches either generate unrealistically dense networks, or fail to reproduce the observed topology by assigning homogeneous link weights. Here, we develop a reconstruction method, based on statistical mechanics concepts, that makes use of the empirical link density in a highly nontrivial way. Technically, our approach consists in the preliminary estimation of node degrees from empirical node strengths and link density, followed by a maximum-entropy inference based on a combination of empirical strengths and estimated degrees. Our method is successfully tested on the international trade network and the interbank money market, and represents a valuable tool for gaining insights on privacy-protected or partially accessible systems.

Nonparametric analysis of bivariate gap time with competing risks.

PubMed

Huang, Chiung-Yu; Wang, Chenguang; Wang, Mei-Cheng

2016-09-01

This article considers nonparametric methods for studying recurrent disease and death with competing risks. We first point out that comparisons based on the well-known cumulative incidence function can be confounded by different prevalence rates of the competing events, and that comparisons of the conditional distribution of the survival time given the failure event type are more relevant for investigating the prognosis of different patterns of recurrence disease. We then propose nonparametric estimators for the conditional cumulative incidence function as well as the conditional bivariate cumulative incidence function for the bivariate gap times, that is, the time to disease recurrence and the residual lifetime after recurrence. To quantify the association between the two gap times in the competing risks setting, a modified Kendall's tau statistic is proposed. The proposed estimators for the conditional bivariate cumulative incidence distribution and the association measure account for the induced dependent censoring for the second gap time. Uniform consistency and weak convergence of the proposed estimators are established. Hypothesis testing procedures for two-sample comparisons are discussed. Numerical simulation studies with practical sample sizes are conducted to evaluate the performance of the proposed nonparametric estimators and tests. An application to data from a pancreatic cancer study is presented to illustrate the methods developed in this article. © 2016, The International Biometric Society.

Unstable and Multiple Child Care Arrangements and Young Children’s Behavior

PubMed Central

Pilarz, Alejandra Ros; Hill, Heather D.

2015-01-01

Growing evidence suggests that child care instability is associated with child behavior problems, but existing studies confound different types of instability; use small, convenience samples; and/or control insufficiently for selection into child care arrangements. This study uses survey and calendar data from the Fragile Families and Child Well-Being Study to estimate the associations between three different types of child care instability—long-term instability, multiplicity, and the use of back-up arrangements—and children’s internalizing, externalizing, and prosocial behaviors at age 3, controlling for a large number of child and family background characteristics. Long-term instability between birth and age 3, as measured in both the survey and calendar data, is associated with higher levels of externalizing behavior problems. Current multiplicity at age 3 (as measured by survey data) is associated with higher levels of both externalizing and internalizing behavior problems, but stable multiplicity over time (as measured using calendar data) is not. Finally, the use of back-up arrangements at age 3 is associated with higher levels of internalizing behaviors. We find no consistent differences in these results by the timing of instability, child gender, family income, or type of care. PMID:25635158

Disturbance observer-based fuzzy control for flexible spacecraft combined attitude & sun tracking system

NASA Astrophysics Data System (ADS)

Chak, Yew-Chung; Varatharajoo, Renuganth; Razoumny, Yury

2017-04-01

This paper investigates the combined attitude and sun-tracking control problem in the presence of external disturbances and internal disturbances, caused by flexible appendages. A new method based on Pythagorean trigonometric identity is proposed to drive the solar arrays. Using the control input and attitude output, a disturbance observer is developed to estimate the lumped disturbances consisting of the external and internal disturbances, and then compensated by the disturbance observer-based controller via a feed-forward control. The stability analysis demonstrates that the desired attitude trajectories are followed even in the presence of external disturbance and internal flexible modes. The main features of the proposed control scheme are that it can be designed separately and incorporated into the baseline controller to form the observer-based control system, and the combined attitude and sun-tracking control is achieved without the conventional attitude actuators. The attitude and sun-tracking performance using the proposed strategy is evaluated and validated through numerical simulations. The proposed control solution can serve as a fail-safe measure in case of failure of the conventional attitude actuator, which triggered by automatic reconfiguration of the attitude control components.

Response of well aquifer systems to Earth tides: Problem revisited

USGS Publications Warehouse

Hsieh, Paul A.; Bredehoeft, John D.; Rojstaczer, Stuart

1988-01-01

Two recent works cause us to reexamine Bredehoeft's (1967) analysis of earthtide response of water wells. Narasimhan et al. (1984) raise several questions regarding Bredehoeft's (1967) analysis and suggest that the analysis is internally inconsistent. They argue that one cannot directly estimate the specific storage, which characterizes the drained behavior of a porous medium, from earth tide response, which is an undrained phenomenon. We resolve the questions raised by Narasimhan et al. (1984) and show that Bredehoeft's analysis is internally consistent. In addition, we show that it is possible to determine the specific storage from undrained loading. While Bredehoeft's analysis is somewhat heuristic and neglects grain compressibility, Van der Kamp and Gale (1983) present a more rigorous analysis that is based on Biot's (1941) constitutive relationships and accounts for grain compressibility. However, their results reduce to Bredehoeft's results when grains are assumed incompressible. This suggests that Bredehoeft's analysis has incorporated all the essential features of Biot's relationships except for grain compressibility. Upon reexamining Bredehoeft's analysis we find that this is indeed the case.

Seismic, satellite, and site observations of internal solitary waves in the NE South China Sea

PubMed Central

Tang, Qunshu; Wang, Caixia; Wang, Dongxiao; Pawlowicz, Rich

2014-01-01

Internal solitary waves (ISWs) in the NE South China Sea (SCS) are tidally generated at the Luzon Strait. Their propagation, evolution, and dissipation processes involve numerous issues still poorly understood. Here, a novel method of seismic oceanography capable of capturing oceanic finescale structures is used to study ISWs in the slope region of the NE SCS. Near-simultaneous observations of two ISWs were acquired using seismic and satellite imaging, and water column measurements. The vertical and horizontal length scales of the seismic observed ISWs are around 50 m and 1–2 km, respectively. Wave phase speeds calculated from seismic observations, satellite images, and water column data are consistent with each other. Observed waveforms and vertical velocities also correspond well with those estimated using KdV theory. These results suggest that the seismic method, a new option to oceanographers, can be further applied to resolve other important issues related to ISWs. PMID:24948180

De Novo Coding Variants Are Strongly Associated with Tourette Disorder

PubMed Central

Willsey, A. Jeremy; Fernandez, Thomas V.; Yu, Dongmei; King, Robert A.; Dietrich, Andrea; Xing, Jinchuan; Sanders, Stephan J.; Mandell, Jeffrey D.; Huang, Alden Y.; Richer, Petra; Smith, Louw; Dong, Shan; Samocha, Kaitlin E.; Neale, Benjamin M.; Coppola, Giovanni; Mathews, Carol A.; Tischfield, Jay A.; Scharf, Jeremiah M.; State, Matthew W.; Heiman, Gary A.

2017-01-01

SUMMARY Whole-exome sequencing (WES) and de novo variant detection have proven a powerful approach to gene discovery in complex neurodevelopmental disorders. We have completed WES of 325 Tourette disorder trios from the Tourette International Collaborative Genetics cohort and a replication sample of 186 trios from the Tourette Syndrome Association International Consortium on Genetics (511 total). We observe strong and consistent evidence for the contribution of de novo likely gene-disrupting (LGD) variants (rate ratio [RR] 2.32, p = 0.002). Additionally, de novo damaging variants (LGD and probably damaging missense) are overrepresented in probands (RR 1.37, p = 0.003). We identify four likely risk genes with multiple de novo damaging variants in unrelated probands: WWC1 (WW and C2 domain containing 1), CELSR3 (Cadherin EGF LAG seven-pass G-type receptor 3), NIPBL (Nipped-B-like), and FN1 (fibronectin 1). Overall, we estimate that de novo damaging variants in approximately 400 genes contribute risk in 12% of clinical cases. PMID:28472652

Internal alignment and position resolution of the silicon tracker of DAMPE determined with orbit data

NASA Astrophysics Data System (ADS)

Tykhonov, A.; Ambrosi, G.; Asfandiyarov, R.; Azzarello, P.; Bernardini, P.; Bertucci, B.; Bolognini, A.; Cadoux, F.; D'Amone, A.; De Benedittis, A.; De Mitri, I.; Di Santo, M.; Dong, Y. F.; Duranti, M.; D'Urso, D.; Fan, R. R.; Fusco, P.; Gallo, V.; Gao, M.; Gargano, F.; Garrappa, S.; Gong, K.; Ionica, M.; La Marra, D.; Lei, S. J.; Li, X.; Loparco, F.; Marsella, G.; Mazziotta, M. N.; Peng, W. X.; Qiao, R.; Salinas, M. M.; Surdo, A.; Vagelli, V.; Vitillo, S.; Wang, H. Y.; Wang, J. Z.; Wang, Z. M.; Wu, D.; Wu, X.; Zhang, F.; Zhang, J. Y.; Zhao, H.; Zimmer, S.

2018-06-01

The DArk Matter Particle Explorer (DAMPE) is a space-borne particle detector designed to probe electrons and gamma-rays in the few GeV to 10 TeV energy range, as well as cosmic-ray proton and nuclei components between 10 GeV and 100 TeV. The silicon-tungsten tracker-converter is a crucial component of DAMPE. It allows the direction of incoming photons converting into electron-positron pairs to be estimated, and the trajectory and charge (Z) of cosmic-ray particles to be identified. It consists of 768 silicon micro-strip sensors assembled in 6 double layers with a total active area of 6.6 m2. Silicon planes are interleaved with three layers of tungsten plates, resulting in about one radiation length of material in the tracker. Internal alignment parameters of the tracker have been determined on orbit, with non-showering protons and helium nuclei. We describe the alignment procedure and present the position resolution and alignment stability measurements.

Are Informant Reports of Personality More Internally Consistent Than Self Reports of Personality?

PubMed

Balsis, Steve; Cooper, Luke D; Oltmanns, Thomas F

2015-08-01

The present study examined whether informant-reported personality was more or less internally consistent than self-reported personality in an epidemiological community sample (n = 1,449). Results indicated that across the 5 NEO (Neuroticism-Extraversion-Openness) personality factors and the 10 personality disorder trait dimensions, informant reports tended to be more internally consistent than self reports, as indicated by equal or higher Cronbach's alpha scores and higher average interitem correlations. In addition, the informant reports collectively outperformed the self reports for predicting responses on a global measure of health, indicating that the informant reports are not only more reliable than self reports, but they can also be useful in predicting an external criterion. Collectively these findings indicate that informant reports tend to have greater internal consistency than self reports. © The Author(s) 2014.

Estimation of some transducer parameters in a broadband piezoelectric transmitter by using an artificial intelligence technique.

PubMed

Ruíz, A; Ramos, A; San Emeterio, J L

2004-04-01

An estimation procedure to efficiently find approximate values of internal parameters in ultrasonic transducers intended for broadband operation would be a valuable tool to discover internal construction data. This information is necessary in the modelling and simulation of acoustic and electrical behaviour related to ultrasonic systems containing commercial transducers. There is not a general solution for this generic problem of parameter estimation in the case of broadband piezoelectric probes. In this paper, this general problem is briefly analysed for broadband conditions. The viability of application in this field of an artificial intelligence technique supported on the modelling of the transducer internal components is studied. A genetic algorithm (GA) procedure is presented and applied to the estimation of different parameters, related to two transducers which are working as pulsed transmitters. The efficiency of this GA technique is studied, considering the influence of the number and variation range of the estimated parameters. Estimation results are experimentally ratified.

Monopole and dipole estimation for multi-frequency sky maps by linear regression

NASA Astrophysics Data System (ADS)

Wehus, I. K.; Fuskeland, U.; Eriksen, H. K.; Banday, A. J.; Dickinson, C.; Ghosh, T.; Górski, K. M.; Lawrence, C. R.; Leahy, J. P.; Maino, D.; Reich, P.; Reich, W.

2017-01-01

We describe a simple but efficient method for deriving a consistent set of monopole and dipole corrections for multi-frequency sky map data sets, allowing robust parametric component separation with the same data set. The computational core of this method is linear regression between pairs of frequency maps, often called T-T plots. Individual contributions from monopole and dipole terms are determined by performing the regression locally in patches on the sky, while the degeneracy between different frequencies is lifted whenever the dominant foreground component exhibits a significant spatial spectral index variation. Based on this method, we present two different, but each internally consistent, sets of monopole and dipole coefficients for the nine-year WMAP, Planck 2013, SFD 100 μm, Haslam 408 MHz and Reich & Reich 1420 MHz maps. The two sets have been derived with different analysis assumptions and data selection, and provide an estimate of residual systematic uncertainties. In general, our values are in good agreement with previously published results. Among the most notable results are a relative dipole between the WMAP and Planck experiments of 10-15μK (depending on frequency), an estimate of the 408 MHz map monopole of 8.9 ± 1.3 K, and a non-zero dipole in the 1420 MHz map of 0.15 ± 0.03 K pointing towards Galactic coordinates (l,b) = (308°,-36°) ± 14°. These values represent the sum of any instrumental and data processing offsets, as well as any Galactic or extra-Galactic component that is spectrally uniform over the full sky.

Family strengths and the Kansas Marital Satisfaction Scale: a factor analytic study.

PubMed

Schumm, W R; Bollman, S R; Jurich, A P; Hatch, R C

2001-06-01

20 new items were developed to measure six concepts of family strengths and were administered, along with the Kansas Marital Satisfaction Scale, to over 266 married subjects as part of a larger survey of current and former members of the Christian Church (Disciples of Christ). A common factor analysis suggested that most of the items were associated with their expected factors, while reliability analyses indicated that most of the scales had acceptable estimates of internal consistency. The marital satisfaction items clearly were associated with their own factor and not other factors, providing support for the unidimensional nature of the Kansas Marital Satisfaction Scale and for its construct validity.

Testing of the SEE and OEE post-hip fracture.

PubMed

Resnick, Barbara; Orwig, Denise; Zimmerman, Sheryl; Hawkes, William; Golden, Justine; Werner-Bronzert, Michelle; Magaziner, Jay

2006-08-01

The purpose of this study was to test the reliability and validity of the Self-Efficacy for Exercise (SEE) and the Outcome Expectations for Exercise (OEE) scales in a sample of 166 older women post-hip fracture. There was some evidence of validity of the SEE and OEE based on confirmatory factor analysis and Rasch model testing, criterion based and convergent validity, and evidence of internal consistency based on alpha coefficients and separation indices and reliability based on R2 estimates. Rasch model testing demonstrated that some items had high variability. Based on these findings suggestions are made for how items could be revised and the scales improved for future use.

Determination of fenoterol in human plasma by HPLC with fluorescence detection after derivatization.

PubMed

Meineke, Ingolf; Steinmetz, Hannelore; Kramer, Skaidrit; Gleiter, Christoph H

2002-06-20

A new method for the determination of fenoterol is described, which uses HPLC separation with fluorescence detection. Dobutamine is employed as an internal standard. The separation was achieved on a short reversed phase column with a mobile phase consisting of water, acetonitrile and methanol. Prior to chromatography both analytes are derivatized with 9-chloroformyl-carbazole. Isolation of the analytes from plasma is carried out by liquid-liquid extraction into 2-butanol after protein precipitation with acetonitrile. The method is capable of estimating fenoterol concentrations in the sub-nanogram per ml range with sufficient accuracy and precision. The determination of fenoterol can now be carried out in the average laboratory without radiolabelled material.

Fetal Biometry Studies of Malaysian Pregnant Women and Comparison with International Charts

NASA Astrophysics Data System (ADS)

Adam, N.; Ramli, R. M.; Jaafar, M. S.

2010-07-01

Fetal biometry is a measurement done on fetus anatomy to relate the fetus growth with gestational age (GA). In this study [1], fetal biometry that was studied consists of biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL). Studies were carried out at Maternity Unit, Hospital Pulau Penang. From the finding, it is understood that fetal biometry distinguish the normal from abnormal fetal structures and it vary among different populations, depending upon their racial [2,3] and nutrition [4,5,6]. True findings are valuable in estimating the gestational age of the fetus, abnormalities in fetus and the consideration of maternal health specific to the Malaysian population.

Critical parameters, thermodynamic functions, and shock Hugoniot of aluminum fluid at high energy density

NASA Astrophysics Data System (ADS)

Zaghloul, Mofreh R.

2018-03-01

We present estimates of the critical properties, thermodynamic functions, and principal shock Hugoniot of hot dense aluminum fluid as predicted from a chemical model for the equation-of-state of hot dense, partially ionized and partially degenerate plasma. The essential features of strongly coupled plasma of metal vapors, such as multiple ionization, Coulomb interactions among charged particles, partial degeneracy, and intensive short range hard core repulsion are taken into consideration. Internal partition functions of neutral, excited, and multiply ionized species are carefully evaluated in a statistical-mechanically consistent way. Results predicted from the present model are presented, analyzed and compared with available experimental measurements and other theoretical predictions in the literature.

The Healthy Worker Effect and Nuclear Industry Workers

PubMed Central

Fornalski, Krzysztof W.; Dobrzyński, Ludwik

2010-01-01

The linear no-threshold (LNT) dose-effect relationship has been consistently used by most radiation epidemiologists to estimate cancer mortality risk. The large scattering of data by International Agency for Research on Cancer, IARC (Vrijheid et al. 2007; Therry-Chef et al. 2007; Cardis et al. 2007), interpreted in accordance with LNT, has been previously demonstrated (Fornalski and Dobrzyński 2009). Using conventional and Bayesian methods the present paper demonstrates that the standard mortality ratios (SMRs), lower in the IARC cohort of exposed nuclear workers than in the non exposed group, should be considered as a hormetic effect, rather than a healthy worker effect (HWE) as claimed by the IARC group. PMID:20585442

Energy-density field approach for low- and medium-frequency vibroacoustic analysis of complex structures using a statistical computational model

NASA Astrophysics Data System (ADS)

Kassem, M.; Soize, C.; Gagliardini, L.

2009-06-01

In this paper, an energy-density field approach applied to the vibroacoustic analysis of complex industrial structures in the low- and medium-frequency ranges is presented. This approach uses a statistical computational model. The analyzed system consists of an automotive vehicle structure coupled with its internal acoustic cavity. The objective of this paper is to make use of the statistical properties of the frequency response functions of the vibroacoustic system observed from previous experimental and numerical work. The frequency response functions are expressed in terms of a dimensionless matrix which is estimated using the proposed energy approach. Using this dimensionless matrix, a simplified vibroacoustic model is proposed.

Design and evaluation of a robust dynamic neurocontroller for a multivariable aircraft control problem

NASA Technical Reports Server (NTRS)

Troudet, T.; Garg, S.; Merrill, W.

1992-01-01

The design of a dynamic neurocontroller with good robustness properties is presented for a multivariable aircraft control problem. The internal dynamics of the neurocontroller are synthesized by a state estimator feedback loop. The neurocontrol is generated by a multilayer feedforward neural network which is trained through backpropagation to minimize an objective function that is a weighted sum of tracking errors, and control input commands and rates. The neurocontroller exhibits good robustness through stability margins in phase and vehicle output gains. By maintaining performance and stability in the presence of sensor failures in the error loops, the structure of the neurocontroller is also consistent with the classical approach of flight control design.

Absolute probability estimates of lethal vessel strikes to North Atlantic right whales in Roseway Basin, Scotian Shelf.

PubMed

van der Hoop, Julie M; Vanderlaan, Angelia S M; Taggart, Christopher T

2012-10-01

Vessel strikes are the primary source of known mortality for the endangered North Atlantic right whale (Eubalaena glacialis). Multi-institutional efforts to reduce mortality associated with vessel strikes include vessel-routing amendments such as the International Maritime Organization voluntary "area to be avoided" (ATBA) in the Roseway Basin right whale feeding habitat on the southwestern Scotian Shelf. Though relative probabilities of lethal vessel strikes have been estimated and published, absolute probabilities remain unknown. We used a modeling approach to determine the regional effect of the ATBA, by estimating reductions in the expected number of lethal vessel strikes. This analysis differs from others in that it explicitly includes a spatiotemporal analysis of real-time transits of vessels through a population of simulated, swimming right whales. Combining automatic identification system (AIS) vessel navigation data and an observationally based whale movement model allowed us to determine the spatial and temporal intersection of vessels and whales, from which various probability estimates of lethal vessel strikes are derived. We estimate one lethal vessel strike every 0.775-2.07 years prior to ATBA implementation, consistent with and more constrained than previous estimates of every 2-16 years. Following implementation, a lethal vessel strike is expected every 41 years. When whale abundance is held constant across years, we estimate that voluntary vessel compliance with the ATBA results in an 82% reduction in the per capita rate of lethal strikes; very similar to a previously published estimate of 82% reduction in the relative risk of a lethal vessel strike. The models we developed can inform decision-making and policy design, based on their ability to provide absolute, population-corrected, time-varying estimates of lethal vessel strikes, and they are easily transported to other regions and situations.

Estimating Contraceptive Prevalence Using Logistics Data for Short-Acting Methods: Analysis Across 30 Countries.

PubMed

Cunningham, Marc; Bock, Ariella; Brown, Niquelle; Sacher, Suzy; Hatch, Benjamin; Inglis, Andrew; Aronovich, Dana

2015-09-01

Contraceptive prevalence rate (CPR) is a vital indicator used by country governments, international donors, and other stakeholders for measuring progress in family planning programs against country targets and global initiatives as well as for estimating health outcomes. Because of the need for more frequent CPR estimates than population-based surveys currently provide, alternative approaches for estimating CPRs are being explored, including using contraceptive logistics data. Using data from the Demographic and Health Surveys (DHS) in 30 countries, population data from the United States Census Bureau International Database, and logistics data from the Procurement Planning and Monitoring Report (PPMR) and the Pipeline Monitoring and Procurement Planning System (PipeLine), we developed and evaluated 3 models to generate country-level, public-sector contraceptive prevalence estimates for injectable contraceptives, oral contraceptives, and male condoms. Models included: direct estimation through existing couple-years of protection (CYP) conversion factors, bivariate linear regression, and multivariate linear regression. Model evaluation consisted of comparing the referent DHS prevalence rates for each short-acting method with the model-generated prevalence rate using multiple metrics, including mean absolute error and proportion of countries where the modeled prevalence rate for each method was within 1, 2, or 5 percentage points of the DHS referent value. For the methods studied, family planning use estimates from public-sector logistics data were correlated with those from the DHS, validating the quality and accuracy of current public-sector logistics data. Logistics data for oral and injectable contraceptives were significantly associated (P<.05) with the referent DHS values for both bivariate and multivariate models. For condoms, however, that association was only significant for the bivariate model. With the exception of the CYP-based model for condoms, models were able to estimate public-sector prevalence rates for each short-acting method to within 2 percentage points in at least 85% of countries. Public-sector contraceptive logistics data are strongly correlated with public-sector prevalence rates for short-acting methods, demonstrating the quality of current logistics data and their ability to provide relatively accurate prevalence estimates. The models provide a starting point for generating interim estimates of contraceptive use when timely survey data are unavailable. All models except the condoms CYP model performed well; the regression models were most accurate but the CYP model offers the simplest calculation method. Future work extending the research to other modern methods, relating subnational logistics data with prevalence rates, and tracking that relationship over time is needed. © Cunningham et al.

Estimating Contraceptive Prevalence Using Logistics Data for Short-Acting Methods: Analysis Across 30 Countries

PubMed Central

Cunningham, Marc; Brown, Niquelle; Sacher, Suzy; Hatch, Benjamin; Inglis, Andrew; Aronovich, Dana

2015-01-01

Background: Contraceptive prevalence rate (CPR) is a vital indicator used by country governments, international donors, and other stakeholders for measuring progress in family planning programs against country targets and global initiatives as well as for estimating health outcomes. Because of the need for more frequent CPR estimates than population-based surveys currently provide, alternative approaches for estimating CPRs are being explored, including using contraceptive logistics data. Methods: Using data from the Demographic and Health Surveys (DHS) in 30 countries, population data from the United States Census Bureau International Database, and logistics data from the Procurement Planning and Monitoring Report (PPMR) and the Pipeline Monitoring and Procurement Planning System (PipeLine), we developed and evaluated 3 models to generate country-level, public-sector contraceptive prevalence estimates for injectable contraceptives, oral contraceptives, and male condoms. Models included: direct estimation through existing couple-years of protection (CYP) conversion factors, bivariate linear regression, and multivariate linear regression. Model evaluation consisted of comparing the referent DHS prevalence rates for each short-acting method with the model-generated prevalence rate using multiple metrics, including mean absolute error and proportion of countries where the modeled prevalence rate for each method was within 1, 2, or 5 percentage points of the DHS referent value. Results: For the methods studied, family planning use estimates from public-sector logistics data were correlated with those from the DHS, validating the quality and accuracy of current public-sector logistics data. Logistics data for oral and injectable contraceptives were significantly associated (P<.05) with the referent DHS values for both bivariate and multivariate models. For condoms, however, that association was only significant for the bivariate model. With the exception of the CYP-based model for condoms, models were able to estimate public-sector prevalence rates for each short-acting method to within 2 percentage points in at least 85% of countries. Conclusions: Public-sector contraceptive logistics data are strongly correlated with public-sector prevalence rates for short-acting methods, demonstrating the quality of current logistics data and their ability to provide relatively accurate prevalence estimates. The models provide a starting point for generating interim estimates of contraceptive use when timely survey data are unavailable. All models except the condoms CYP model performed well; the regression models were most accurate but the CYP model offers the simplest calculation method. Future work extending the research to other modern methods, relating subnational logistics data with prevalence rates, and tracking that relationship over time is needed. PMID:26374805

Development and Validation of the 34-Item Disability Screening Questionnaire (DSQ-34) for Use in Low and Middle Income Countries Epidemiological and Development Surveys

PubMed Central

Trani, Jean-François; Babulal, Ganesh Muneshwar; Bakhshi, Parul

2015-01-01

Background Although 80% of persons with disabilities live in low and middle-income countries, there is still a lack of comprehensive, cross-culturally validated tools to identify persons facing activity limitations and functioning difficulties in these settings. In absence of such a tool, disability estimates vary considerably according to the methodology used, and policies are based on unreliable estimates. Methods and Findings The Disability Screening Questionnaire composed of 27 items (DSQ-27) was initially designed by a group of international experts in survey development and disability in Afghanistan for a national survey. Items were selected based on major domains of activity limitations and functioning difficulties linked to an impairment as defined by the International Classification of Functioning, Disability and Health. Face, content and construct validity, as well as sensitivity and specificity were examined. Based on the results obtained, the tool was subsequently refined and expanded to 34 items, tested and validated in Darfur, Sudan. Internal consistency for the total DSQ-34 using a raw and standardized Cronbach’s Alpha and within each domain using a standardized Cronbach’s Alpha was examined in the Asian context (India and Nepal). Exploratory factor analysis (EFA) using principal axis factoring (PAF) evaluated the lowest number of factors to account for the common variance among the questions in the screen. Test-retest reliability was determined by calculating intraclass correlation (ICC) and inter-rater reliability by calculating the kappa statistic; results were checked using Bland-Altman plots. The DSQ-34 was further tested for standard error of measurement (SEM) and for the minimum detectable change (MDC). Good internal consistency was indicated by Cronbach’s Alpha of 0.83/0.82 for India and 0.76/0.78 for Nepal. We confirmed our assumption for EFA using the Kaiser-Meyer-Olkin measure of sampling well above the accepted cutoff of 0.40 for India (0.82) and Nepal (0.82). The criteria for Bartlett’s test of sphericity were also met for both India (< .001) and Nepal (< .001). Estimates of reliability from the two countries reached acceptable levels of ICC of 0.75 (p<0.001) for India of 0.77 for Nepal (p<0.001) and good strength of agreement for weighted kappa (respectively 0.77 and 0.79). The SEM/MDC was 0.80/2.22 for India and 0.96/2.66 for Nepal indicating a smaller amount of measurement error in the screen. Conclusions In Nepal and India, the DSQ-34 shows strong psychometric properties that indicate that it effectively discriminates between persons with and without disabilities. This instrument can be used in association with other instruments for the purpose of comparing health outcomes of persons with and without disabilities in LMICs. PMID:26630668

Three-dimensional analysis of magnetometer array data

NASA Technical Reports Server (NTRS)

Richmond, A. D.; Baumjohann, W.

1984-01-01

A technique is developed for mapping magnetic variation fields in three dimensions using data from an array of magnetometers, based on the theory of optimal linear estimation. The technique is applied to data from the Scandinavian Magnetometer Array. Estimates of the spatial power spectra for the internal and external magnetic variations are derived, which in turn provide estimates of the spatial autocorrelation functions of the three magnetic variation components. Statistical errors involved in mapping the external and internal fields are quantified and displayed over the mapping region. Examples of field mapping and of separation into external and internal components are presented. A comparison between the three-dimensional field separation and a two-dimensional separation from a single chain of stations shows that significant differences can arise in the inferred internal component.

Investigating the detection of multi-homed devices independent of operating systems

DTIC Science & Technology

2017-09-01

timestamp data was used to estimate clock skews using linear regression and linear optimization methods. Analysis revealed that detection depends on...the consistency of the estimated clock skew. Through vertical testing, it was also shown that clock skew consistency depends on the installed...optimization methods. Analysis revealed that detection depends on the consistency of the estimated clock skew. Through vertical testing, it was also

The age of the 20 meter Solo River terrace, Java, Indonesia and the survival of Homo erectus in Asia.

PubMed

Indriati, Etty; Swisher, Carl C; Lepre, Christopher; Quinn, Rhonda L; Suriyanto, Rusyad A; Hascaryo, Agus T; Grün, Rainer; Feibel, Craig S; Pobiner, Briana L; Aubert, Maxime; Lees, Wendy; Antón, Susan C

2011-01-01

Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35-50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report (40)Ar/(39)Ar incremental heating analyses and new ESR/U-series age estimates from the "20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The (40)Ar/(39)Ar analyses give an average age of 546±12 ka (sd±5 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/-17. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and (40)Ar/(39)Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted.

The Age of the 20 Meter Solo River Terrace, Java, Indonesia and the Survival of Homo erectus in Asia

PubMed Central

Indriati, Etty; Swisher, Carl C.; Lepre, Christopher; Quinn, Rhonda L.; Suriyanto, Rusyad A.; Hascaryo, Agus T.; Grün, Rainer; Feibel, Craig S.; Pobiner, Briana L.; Aubert, Maxime; Lees, Wendy; Antón, Susan C.

2011-01-01

Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35–50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report 40Ar/39Ar incremental heating analyses and new ESR/U-series age estimates from the “20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The 40Ar/39Ar analyses give an average age of 546±12 ka (sd±5 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/−17. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and 40Ar/39Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted. PMID:21738710

Estimating the risk of a scuba diving fatality in Australia.

PubMed

Lippmann, John; Stevenson, Christopher; McD Taylor, David; Williams, Jo

2016-12-01

There are few data available on which to estimate the risk of death for Australian divers. This report estimates the risk of a scuba diving fatality for Australian residents, international tourists diving in Queensland, and clients of a large Victorian dive operator. Numerators for the estimates were obtained from the Divers Alert Network Asia-Pacific dive fatality database. Denominators were derived from three sources: Participation in Exercise, Recreation and Sport Surveys, 2001-2010 (Australian resident diving activity data); Tourism Research Australia surveys of international visitors to Queensland 2006-2014 and a dive operator in Victoria 2007-2014. Annual fatality rates (AFR) and 95% confidence intervals (95% CI) were calculated using an exact binomial test. Estimated AFRs were: 0.48 (0.37-0.59) deaths per 100,000 dives, or 8.73 (6.85-10.96) deaths per 100,000 divers for Australian residents; 0.12 (0.05-0.25) deaths per 100,000 dives, or 0.46 (0.20-0.91) deaths per 100,000 divers for international visitors to Queensland; and 1.64 (0.20-5.93) deaths per 100,000 dives for the dive operator in Victoria. On a per diver basis, Australian residents are estimated to be almost twenty times more likely to die whilst scuba diving than are international visitors to Queensland, or to lower than fourfold on a per dive basis. On a per dive basis, divers in Victoria are fourteen times more likely to die than are Queensland international tourists. Although some of the estimates are based on potentially unreliable denominator data extrapolated from surveys, the diving fatality rates in Australia appear to vary by State, being considerably lower in Queensland than in Victoria. These estimates are similar to or lower than comparable overseas estimates, although reliability of all such measurements varies with study size and accuracy of the data available.

Assessment of the reliability and consistency of the "malnutrition inflammation score" (MIS) in Mexican adults with chronic kidney disease for diagnosis of protein-energy wasting syndrome (PEW).

PubMed

González-Ortiz, Ailema Janeth; Arce-Santander, Celene Viridiana; Vega-Vega, Olynka; Correa-Rotter, Ricardo; Espinosa-Cuevas, María de Los Angeles

2014-10-04

The protein-energy wasting syndrome (PEW) is a condition of malnutrition, inflammation, anorexia and wasting of body reserves resulting from inflammatory and non-inflammatory conditions in patients with chronic kidney disease (CKD).One way of assessing PEW, extensively described in the literature, is using the Malnutrition Inflammation Score (MIS). To assess the reliability and consistency of MIS for diagnosis of PEW in Mexican adults with CKD on hemodialysis (HD). Study of diagnostic tests. A sample of 45 adults with CKD on HD were analyzed during the period June-July 2014.The instrument was applied on 2 occasions; the test-retest reliability was calculated using the Intraclass Correlation Coefficient (ICC); the internal consistency of the questionnaire was analyzed using Cronbach's αcoefficient. A weighted Kappa test was used to estimate the validity of the instrument; the result was subsequently compared with the Bilbrey nutritional index (BNI). The reliability of the questionnaires, evaluated in the patient sample, was ICC=0.829.The agreement between MIS observations was considered adequate, k= 0.585 (p <0.001); when comparing it with BNI, a value of k = 0.114 was obtained (p <0.001).In order to estimate the tendency, a correlation test was performed. The r² correlation coefficient was 0.488 (P <0.001). MIS has adequate reliability and validity for diagnosing PEW in the population with chronic kidney disease on HD. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Multi-GNSS real-time precise orbit/clock/UPD products and precise positioning service at GFZ

NASA Astrophysics Data System (ADS)

Li, Xingxing; Ge, Maorong; Liu, Yang; Fritsche, Mathias; Wickert, Jens; Schuh, Harald

2016-04-01

The rapid development of multi-constellation GNSSs (Global Navigation Satellite Systems, e.g., BeiDou, Galileo, GLONASS, GPS) and the IGS (International GNSS Service) Multi-GNSS Experiment (MGEX) bring great opportunities and challenges for real-time precise positioning service. In this contribution, we present a GPS+GLONASS+BeiDou+Galileo four-system model to fully exploit the observations of all these four navigation satellite systems for real-time precise orbit determination, clock estimation and positioning. A rigorous multi-GNSS analysis is performed to achieve the best possible consistency by processing the observations from different GNSS together in one common parameter estimation procedure. Meanwhile, an efficient multi-GNSS real-time precise positioning service system is designed and demonstrated by using the Multi-GNSS Experiment (MGEX) and International GNSS Service (IGS) data streams including stations all over the world. The addition of the BeiDou, Galileo and GLONASS systems to the standard GPS-only processing, reduces the convergence time almost by 70%, while the positioning accuracy is improved by about 25%. Some outliers in the GPS-only solutions vanish when multi-GNSS observations are processed simultaneous. The availability and reliability of GPS precise positioning decrease dramatically as the elevation cutoff increases. However, the accuracy of multi-GNSS precise point positioning (PPP) is hardly decreased and few centimeters are still achievable in the horizontal components even with 40° elevation cutoff.

Association between tax structure and cigarette consumption: findings from the International Tobacco Control Policy Evaluation (ITC) Project.

PubMed

Shang, Ce; Lee, Hye Myung; Chaloupka, Frank J; Fong, Geoffrey T; Thompson, Mary; O'Connor, Richard J

2018-05-24

Recent studies show that greater price variability and more opportunities for tax avoidance are associated with tax structures that depart from a specific uniform one. These findings indicate that tax structures other than a specific uniform one may lead to more cigarette consumption. This paper aims to examine how cigarette tax structure is associated with cigarette consumption. We used survey data taken from the International Tobacco Control Policy Evaluation Project in 17 countries to conduct the analysis. Self-reported cigarette consumption was aggregated to average measures for each surveyed country and wave. The effect of tax structures on cigarette consumption was estimated using generalised estimating equations after adjusting for sociodemographic characteristics, average taxes and year fixed effects. Our study provides important empirical evidence of a relationship between tax structure and cigarette consumption. We find that a change from a specific to an ad valorem structure is associated with a 6%-11% higher cigarette consumption. In addition, a change from uniform to tiered structure is associated with a 34%-65% higher cigarette consumption. The results are consistent with existing evidence and suggest that a uniform and specific tax structure is the most effective tax structure for reducing tobacco consumption. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Novel 18650 lithium-ion battery surrogate cell design with anisotropic thermophysical properties for studying failure events

NASA Astrophysics Data System (ADS)

Spinner, Neil S.; Hinnant, Katherine M.; Mazurick, Ryan; Brandon, Andrew; Rose-Pehrsson, Susan L.; Tuttle, Steven G.

2016-04-01

Cylindrical 18650-type surrogate cells were designed and fabricated to mimic the thermophysical properties and behavior of active lithium-ion batteries. An internal jelly roll geometry consisting of alternating stainless steel and mica layers was created, and numerous techniques were used to estimate thermophysical properties. Surrogate cell density was measured to be 1593 ± 30 kg/m3, and heat capacity was found to be 727 ± 18 J/kg-K. Axial thermal conductivity was determined to be 5.1 ± 0.6 W/m-K, which was over an order of magnitude higher than radial thermal conductivity due to jelly roll anisotropy. Radial heating experiments were combined with numerical and analytical solutions to the time-dependent, radial heat conduction equation, and from the numerical method an additional estimate for heat capacity of 805 ± 23 J/kg-K was found. Using both heat capacities and analysis techniques, values for radial thermal conductivity were between 0.120 and 0.197 W/m-K. Under normal operating conditions, relatively low radial temperature distributions were observed; however, during extreme battery failure with a hexagonal cell package, instantaneous radial temperature distributions as high as 43-71 °C were seen. For a vertical cell package, even during adjacent cell failure, similar homogeneity in internal temperatures were observed, demonstrating thermal anisotropy.

The development and validation of the On-the-job Learning Styles Questionnaire for the Nursing Profession.

PubMed

Berings, Marjolein G M C; Poell, Rob F; Simons, P Robert-Jan; van Veldhoven, Marc J P M

2007-06-01

This paper is a report of a study to develop and test the psychometric properties of the On-the-job Learning Style Questionnaire for the Nursing Profession. Although numerous questionnaires measuring learning styles have been developed, none are suitable for working environments. Existing instruments do not meet the requirements for use in workplace settings and tend to ignore the influence of different learning situations. The questionnaire was constructed using a situation-response design, measuring learning activities in different on-the-job learning situations. Content validity was ensured by basing the questionnaire on interview studies. The questionnaire was distributed to 912 Registered Nurses working in different departments of 13 general hospitals in the Netherlands at the end of 2005. The response rate was 41% (372 questionnaires). The internal factor structure of the questionnaire was partly based on the learning activities in which nurses participate and partly on the learning situation in which they are performed. The internal consistency was good. The situation-response design of the questionnaire demonstrated its added value. Construct validity was estimated using intercorrelations between the scales, and criterion validity was estimated based on the relationships of the scales with perceived professional competence. The On-the-job Learning Styles Questionnaire for the Nursing Profession is well suited to describing nurses' learning styles in on-the-job settings and has satisfactory psychometric properties.

Second Generation of Mass Estimation

DTIC Science & Technology

2013-09-01

Takashi Washio, Jonathan R. Wells, Fei Tony Liu and Sunil Aryal (2013). DEMass: A New Density Estimator for Big Data. International Journal of Knowledge...and Information Systems. Vol. 35, Issue. 3, pp. 493-524 5.2 List of peer-reviewed conference publications [3] Sunil Aryal and Kai Ming Ting (2013...Measures. Submitted to 2013 IEEE International Conference on Data Mining [6] Sunil Aryal and Kai Ming Ting. An ensemble approach to estimate multi

Psychometric Characteristics of the Korean Version of the Satisfaction with Life Scale Adapted for Children

ERIC Educational Resources Information Center

Lim, Young-Jin

2015-01-01

The aim of this study was to examine the internal consistency reliability, test-retest reliability, factorial structure validity, and convergent validity of a Korean version of the Satisfaction With Life Scale adapted for children (K-SWLS-C). Participants consisted of 653 elementary school students (48% were male). The internal consistency of the…

Probable Maximum Precipitation in the U.S. Pacific Northwest in a Changing Climate

NASA Astrophysics Data System (ADS)

Chen, Xiaodong; Hossain, Faisal; Leung, L. Ruby

2017-11-01

The safety of large and aging water infrastructures is gaining attention in water management given the accelerated rate of change in landscape, climate, and society. In current engineering practice, such safety is ensured by the design of infrastructure for the Probable Maximum Precipitation (PMP). Recently, several numerical modeling approaches have been proposed to modernize the conventional and ad hoc PMP estimation approach. However, the underlying physics have not been fully investigated and thus differing PMP estimates are sometimes obtained without physics-based interpretations. In this study, we present a hybrid approach that takes advantage of both traditional engineering practice and modern climate science to estimate PMP for current and future climate conditions. The traditional PMP approach is modified and applied to five statistically downscaled CMIP5 model outputs, producing an ensemble of PMP estimates in the Pacific Northwest (PNW) during the historical (1970-2016) and future (2050-2099) time periods. The hybrid approach produced consistent historical PMP estimates as the traditional estimates. PMP in the PNW will increase by 50% ± 30% of the current design PMP by 2099 under the RCP8.5 scenario. Most of the increase is caused by warming, which mainly affects moisture availability through increased sea surface temperature, with minor contributions from changes in storm efficiency in the future. Moist track change tends to reduce the future PMP. Compared with extreme precipitation, PMP exhibits higher internal variability. Thus, long-time records of high-quality data in both precipitation and related meteorological fields (temperature, wind fields) are required to reduce uncertainties in the ensemble PMP estimates.

Harmonization of initial estimates of shale gas life cycle greenhouse gas emissions for electric power generation.

PubMed

Heath, Garvin A; O'Donoughue, Patrick; Arent, Douglas J; Bazilian, Morgan

2014-08-05

Recent technological advances in the recovery of unconventional natural gas, particularly shale gas, have served to dramatically increase domestic production and reserve estimates for the United States and internationally. This trend has led to lowered prices and increased scrutiny on production practices. Questions have been raised as to how greenhouse gas (GHG) emissions from the life cycle of shale gas production and use compares with that of conventionally produced natural gas or other fuel sources such as coal. Recent literature has come to different conclusions on this point, largely due to differing assumptions, comparison baselines, and system boundaries. Through a meta-analytical procedure we call harmonization, we develop robust, analytically consistent, and updated comparisons of estimates of life cycle GHG emissions for electricity produced from shale gas, conventionally produced natural gas, and coal. On a per-unit electrical output basis, harmonization reveals that median estimates of GHG emissions from shale gas-generated electricity are similar to those for conventional natural gas, with both approximately half that of the central tendency of coal. Sensitivity analysis on the harmonized estimates indicates that assumptions regarding liquids unloading and estimated ultimate recovery (EUR) of wells have the greatest influence on life cycle GHG emissions, whereby shale gas life cycle GHG emissions could approach the range of best-performing coal-fired generation under certain scenarios. Despite clarification of published estimates through harmonization, these initial assessments should be confirmed through methane emissions measurements at components and in the atmosphere and through better characterization of EUR and practices.

Harmonization of initial estimates of shale gas life cycle greenhouse gas emissions for electric power generation

PubMed Central

Heath, Garvin A.; O’Donoughue, Patrick; Arent, Douglas J.; Bazilian, Morgan

2014-01-01

Recent technological advances in the recovery of unconventional natural gas, particularly shale gas, have served to dramatically increase domestic production and reserve estimates for the United States and internationally. This trend has led to lowered prices and increased scrutiny on production practices. Questions have been raised as to how greenhouse gas (GHG) emissions from the life cycle of shale gas production and use compares with that of conventionally produced natural gas or other fuel sources such as coal. Recent literature has come to different conclusions on this point, largely due to differing assumptions, comparison baselines, and system boundaries. Through a meta-analytical procedure we call harmonization, we develop robust, analytically consistent, and updated comparisons of estimates of life cycle GHG emissions for electricity produced from shale gas, conventionally produced natural gas, and coal. On a per-unit electrical output basis, harmonization reveals that median estimates of GHG emissions from shale gas-generated electricity are similar to those for conventional natural gas, with both approximately half that of the central tendency of coal. Sensitivity analysis on the harmonized estimates indicates that assumptions regarding liquids unloading and estimated ultimate recovery (EUR) of wells have the greatest influence on life cycle GHG emissions, whereby shale gas life cycle GHG emissions could approach the range of best-performing coal-fired generation under certain scenarios. Despite clarification of published estimates through harmonization, these initial assessments should be confirmed through methane emissions measurements at components and in the atmosphere and through better characterization of EUR and practices. PMID:25049378

SLR precision analysis for LAGEOS I and II

NASA Astrophysics Data System (ADS)

Kizilsu, Gaye; Sahin, Muhammed

2000-10-01

This paper deals with the problem of properly weighting satellite observations which are non-uniform in quality. The technique, the variance component estimation method developed by Helmert, was first applied to the 1987 LAGEOS I SLR data by Sahin et al. (1992). This paper investigates the performance of the globally distributed SLR stations using the Helmert type variance component estimation. As well as LAGEOS I data, LAGEOS II data were analysed, in order to compare with the previously analysed 1987 LAGEOS I data. The LAGEOS I and II data used in this research were obtained from the NASA Crustal Dynamics Data Information System (CDDIS), which archives data acquired from stations operated by NASA and by other U.S. and international organizations. The data covers the years 1994, 1995 and 1996. The analysis is based on "full-rate" laser observations, which consist of hundreds to thousands of ranges per satellite pass. The software used is based on the SATAN package (SATellite ANalysis) developed at the Royal Greenwich Observatory in the UK.

The Ukrainian-American Study of Leukemia and Related Disorders Among Chornobyl Cleanup Workers from Ukraine: I. STUDY METHODS

PubMed Central

Romanenko, A.; Bebeshko, V; Hatch, M; Bazyka, D; Finch, S.; Dyagil, I; Reiss, R.; Chumak, V; Bouville, A; Gudzenko, N; Zablotska, L; Pilinskaya, M.; Lyubarets, T.; Bakhanova, E.; Babkina, N.; Trotsiuk, N.; Ledoschuk, B.; Belayev, Y.; Dybsky, S.S.; Ron, E.; Howe, G.

2010-01-01

Thus far there are relatively few data on the risk of leukemia among those who were exposed to external radiation during cleanup operations following the Chornobyl nuclear accident, and results have not been consistent. To investigate this issue further, we assembled a cohort of 110,645 male cleanup workers from Ukraine and identified cases of leukemia occurring during the period 1986 to 2000. Detailed interviews were conducted and individual bone marrow doses were estimated using a new time-and-motion method known as RADRUE (Realistic Analytical Dose Reconstruction with Uncertainty Estimate). See companion paper II for a detailed description of the dosimetry. For the initial analyses we used a nested case-control approach with a minimum of five controls per case, matched for year of birth, oblast (region) of registration and residence. All identified cases were reviewed by an international panel of experts. The dose-response analysis and results are given in companion paper III. PMID:19138036

Parent-child discrepancies in the assessment of children's and adolescents' happiness.

PubMed

López-Pérez, Belén; Wilson, Ellie L

2015-11-01

In this study, we assessed parent-child agreement in the perception of children's general happiness or well-being in typically developing children (10- and 11-year-olds, n = 172) and adolescents (15- and 16-year-olds, n = 185). Despite parent and child reporters providing internally consistent responses in the General Happiness single-item scale and the Oxford Happiness Questionnaire-Short Form, their perceptions about children's and adolescents' general happiness did not correlate. Parents of 10- and 11-year-olds significantly overestimated children's happiness, supporting previous literature on the parents' positivity bias effect. However, parents of 15- and 16-year-olds showed the reverse pattern by underestimating adolescents' happiness. Furthermore, parents' self-reported happiness or well-being (reported 6 months later) significantly correlated with their estimations of children's and adolescents' happiness. Therefore, these results suggest a potential parents' "egocentric bias" when estimating their children's happiness. These findings are discussed in terms of their theoretical and applied implications for research into child-parent relationships. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of the medical exposure doses regarding dental examinations with different X-ray instruments

NASA Astrophysics Data System (ADS)

Liu, Yi-Chi; Chuang, Keh-Shih; Yu, Cheng-Ching; Chao, Jiunn-Hsing; Hsu, Fang-Yuh

2015-11-01

Modern dental X-ray examination that consists of traditional form, panorama, and cone-beamed 3D technologies is one of the most frequent diagnostic applications nowadays. This study used the Rando Phantom and thermoluminescence dosimeters (TLD) to measure the absorbed doses of radiosensitive organs recommended by International Commission on Radiological Protection (ICRP), and whole body effective doses which were delivered due to dental X-ray examination performed with different types of X-ray instrument. Besides, enamel samples which performed reading with Electronic Paramagnetic Resonance (EPR) procedure were also used to estimate the tooth doses. EPR is a dose reconstruction method of measuring free radicals induced by radiation exposure to the calcified tissue (mainly in the tooth enamel or bone) to evaluate the accepted high dose. The tooth doses estimated by TLD and EPR methods were compared. Relationships between the tooth doses and effective doses by dental X-ray examinations with different types of X-ray equipment were investigated in this work.

Measurement of Blood Pressure Using an Arterial Pulsimeter Equipped with a Hall Device

PubMed Central

Lee, Sang-Suk; Nam, Dong-Hyun; Hong, You-Sik; Lee, Woo-Beom; Son, Il-Ho; Kim, Keun-Ho; Choi, Jong-Gu

2011-01-01

To measure precise blood pressure (BP) and pulse rate without using a cuff, we have developed an arterial pulsimeter consisting of a small, portable apparatus incorporating a Hall device. Regression analysis of the pulse wave measured during testing of the arterial pulsimeter was conducted using two equations of the BP algorithm. The estimated values of BP obtained by the cuffless arterial pulsimeter over 5 s were compared with values obtained using electronic or liquid mercury BP meters. The standard deviation between the estimated values and the measured values for systolic and diastolic BP were 8.3 and 4.9, respectively, which are close to the range of values of the BP International Standard. Detailed analysis of the pulse wave measured by the cuffless radial artery pulsimeter by detecting changes in the magnetic field can be used to develop a new diagnostic algorithm for BP, which can be applied to new medical apparatus such as the radial artery pulsimeter. PMID:22319381

A local agreement pattern measure based on hazard functions for survival outcomes.

PubMed

Dai, Tian; Guo, Ying; Peng, Limin; Manatunga, Amita K

2018-03-01

Assessing agreement is often of interest in biomedical and clinical research when measurements are obtained on the same subjects by different raters or methods. Most classical agreement methods have been focused on global summary statistics, which cannot be used to describe various local agreement patterns. The objective of this work is to study the local agreement pattern between two continuous measurements subject to censoring. In this article, we propose a new agreement measure based on bivariate hazard functions to characterize the local agreement pattern between two correlated survival outcomes. The proposed measure naturally accommodates censored observations, fully captures the dependence structure between bivariate survival times and provides detailed information on how the strength of agreement evolves over time. We develop a nonparametric estimation method for the proposed local agreement pattern measure and study theoretical properties including strong consistency and asymptotical normality. We then evaluate the performance of the estimator through simulation studies and illustrate the method using a prostate cancer data example. © 2017, The International Biometric Society.

The Uncertainty of Long-term Linear Trend in Global SST Due to Internal Variation

NASA Astrophysics Data System (ADS)

Lian, Tao

2016-04-01

In most parts of the global ocean, the magnitude of the long-term linear trend in sea surface temperature (SST) is much smaller than the amplitude of local multi-scale internal variation. One can thus use the record of a specified period to arbitrarily determine the value and the sign of the long-term linear trend in regional SST, and further leading to controversial conclusions on how global SST responds to global warming in the recent history. Analyzing the linear trend coefficient estimated by the ordinary least-square method indicates that the linear trend consists of two parts: One related to the long-term change, and the other related to the multi-scale internal variation. The sign of the long-term change can be correctly reproduced only when the magnitude of the linear trend coefficient is greater than a theoretical threshold which scales the influence from the multi-scale internal variation. Otherwise, the sign of the linear trend coefficient will depend on the phase of the internal variation, or in the other words, the period being used. An improved least-square method is then proposed to reduce the theoretical threshold. When apply the new method to a global SST reconstruction from 1881 to 2013, we find that in a large part of Pacific, the southern Indian Ocean and North Atlantic, the influence from the multi-scale internal variation on the sign of the linear trend coefficient can-not be excluded. Therefore, the resulting warming or/and cooling linear trends in these regions can-not be fully assigned to global warming.

Multidecadal Changes in Near-Global Cloud Cover and Estimated Cloud Cover Radiative Forcing

NASA Technical Reports Server (NTRS)

Norris, Joel

2005-01-01

The first paper was Multidecadal changes in near-global cloud cover and estimated cloud cover radiative forcing, by J. R. Norris (2005, J. Geophys. Res. - Atmos., 110, D08206, doi: lO.l029/2004JD005600). This study examined variability in zonal mean surface-observed upper-level (combined midlevel and high-level) and low-level cloud cover over land during 1971-1 996 and over ocean during 1952-1997. These data were averaged from individual synoptic reports in the Extended Edited Cloud Report Archive (EECRA). Although substantial interdecadal variability is present in the time series, long-term decreases in upper-level cloud cover occur over land and ocean at low and middle latitudes in both hemispheres. Near-global upper-level cloud cover declined by 1.5%-sky-cover over land between 1971 and 1996 and by 1.3%-sky-cover over ocean between 1952 and 1997. Consistency between EECRA upper-level cloud cover anomalies and those from the International Satellite Cloud Climatology Project (ISCCP) during 1984-1 997 suggests the surface-observed trends are real. The reduction in surface-observed upper-level cloud cover between the 1980s and 1990s is also consistent with the decadal increase in all-sky outgoing longwave radiation reported by the Earth Radiation Budget Satellite (EMS). Discrepancies occur between time series of EECRA and ISCCP low-level cloud cover due to identified and probable artifacts in satellite and surface cloud data. Radiative effects of surface-observed cloud cover anomalies, called "cloud cover radiative forcing (CCRF) anomalies," are estimated based on a linear relationship to climatological cloud radiative forcing per unit cloud cover. Zonal mean estimated longwave CCRF has decreased over most of the globe. Estimated shortwave CCRF has become slightly stronger over northern midlatitude oceans and slightly weaker over northern midlatitude land areas. A long-term decline in the magnitude of estimated shortwave CCRF occurs over low-latitude land and ocean, but comparison with EMS all-sky reflected shortwave radiation during 1985-1997 suggests this decrease may be underestimated.

Psychometric Evaluation of Two Appetite Questionnaires in Patients With Heart Failure.

PubMed

Andreae, Christina; Strömberg, Anna; Sawatzky, Richard; Årestedt, Kristofer

2015-12-01

Decreased appetite in heart failure (HF) may lead to undernutrition which could negatively influence prognosis. Appetite is a complex clinical issue that is often best measured with the use of self-report instruments. However, there is a lack of self-rated appetite instruments. The Council on Nutrition Appetite Questionnaire (CNAQ) and the Simplified Nutritional Appetite Questionnaire (SNAQ) are validated instruments developed primarily for elderly people. Yet, the psychometric properties have not been evaluated in HF populations. The aim of the present study was to evaluate the psychometric properties of CNAQ and SNAQ in patients with HF. A total of 186 outpatients with reduced ejection fraction and New York Heart Association (NYHA) functional classifications II-IV were included (median age 72 y; 70% men). Data were collected with the use of a questionnaire that included the CNAQ and SNAQ. The psychometric evaluation included data quality, factor structure, construct validity, known-group validity, and internal consistency. Unidimensionality was supported by means of parallel analysis and confirmatory factor analyses (CFAs). The CFA results indicated sufficient model fit. Both construct validity and known-group validity were supported. Internal consistency reliability was acceptable, with ordinal coefficient alpha estimates of 0.82 for CNAQ and 0.77 for SNAQ. CNAQ and SNAQ demonstrated sound psychometric properties and can be used to measure appetite in patients with HF. Copyright © 2015 Elsevier Inc. All rights reserved.

Development of an instrument based on the protection motivation theory to measure factors influencing women's intention to first pap test practice.

PubMed

Hassani, Lale; Dehdari, Tahereh; Hajizadeh, Ebrahim; Shojaeizadeh, Davoud; Abedini, Mehrandokht; Nedjat, Saharnaz

2014-01-01

Given that there are many Iranian women who have never had a Pap smear, this study was designed to develop and validate a measurement tool based on the Protection Motivation Theory to assess factors influencing the Iranian women's intention to perform first Pap testing. In this psychometric research, to determine the Content Validity Index (CVI) and the Content Validity Ratio (CVR), a panel of experts (n=10) reviewed scale items. Reliability was estimated through the Intraclass Correlation Coefficient (n=30) and internal consistency (n=240). Also, factor analysis (exploratory and conformity) was performed on the data of the sample women who had never had a Pap smear test (n=240). A 26-item questionnaire was developed. The CVI and CVR scores of the scale were 0.89 and 0.90, respectively. Exploratory factor analysis loaded a 26-item with seven factors questionnaire (perceived vulnerability and severity, fear, response costs, response efficacy, self-efficacy, and protection motivation (or intention)) that jointly accounted for 72.76% of the observed variance. Confirmatory factor analysis indicated a good fit for the data. Internal consistency (range 0.70-0.93) and test-retest reliability (range 0.72-0.96) of sub-scales were acceptable. This study showed that the designed instrument was a valid and reliable tool for measuring the factors influencing the women's intention to perform their first Pap testing.

Self-Management and Transition Readiness Assessment: Development, Reliability, and Factor Structure of the STARx Questionnaire.

PubMed

Ferris, M; Cohen, S; Haberman, C; Javalkar, K; Massengill, S; Mahan, J D; Kim, S; Bickford, K; Cantu, G; Medeiros, M; Phillips, A; Ferris, M T; Hooper, S R

2015-01-01

The Self-Management and Transition to Adulthood with Rx=Treatment (STARx) Questionnaire was developed to collect information on self-management and health care transition (HCT) skills, via self-report, in a broad population of adolescents and young adults (AYAs) with chronic conditions. Over several iterations, the STARx questionnaire was created with AYA, family, and health provider input. The development and pilot testing of the STARx Questionnaire took place with the assistance of 1219 AYAs with different chronic health conditions, in multiple institutions and settings over three phases: item development, pilot testing, reliability and factor structuring. The three development phases resulted in a final version of the STARx Questionnaire. The exploratory factor analysis of the third version of the 18-item STARx identified six factors that accounted for about 65% of the variance: Medication management, Provider communication, Engagement during appointments, Disease knowledge, Adult health responsibilities, and Resource utilization. Reliability estimates revealed good internal consistency and temporal stability, with the alpha coefficient for the overall scale being .80. The STARx was developmentally sensitive, with older patients scoring significantly higher on nearly every factor than younger patients. The STARx Questionnaire is a reliable, self-report tool with adequate internal consistency, temporal stability, and a strong, multidimensional factor structure. It provides another assessment strategy to measure self-management and transition skills in AYAs with chronic conditions. Copyright © 2015 Elsevier Inc. All rights reserved.

The impact of variation in scaling factors on the estimation of ...

EPA Pesticide Factsheets

Many physiologically based pharmacokinetic (PBPK) models include values for metabolic rate parameters extrapolated from in vitro metabolism studies using scaling factors such as mg of microsomal protein per gram of liver (MPPGL) and liver mass (FVL). Variation in scaling factor values impacts metabolic rate parameter estimates (Vmax) and hence estimates of internal dose used in dose response analysis. The impacts of adult human variation in MPPGL and FVL on estimates of internal dose were assessed using a human PBPK model for BDCM for several internal dose metrics for two exposure scenarios (single 0.25 liter drink of water or 10 minute shower) under plausible (5 micrograms/L) and high level (20 micrograms/L) water concentrations. For both concentrations, all internal dose metrics were changed less than 5% for the showering scenario (combined inhalation and dermal exposure). In contrast, a 27-fold variation in area under the curve for BDCM in venous blood was observed at both oral exposure concentrations, whereas total amount of BDCM metabolized in liver was relatively unchanged. This analysis demonstrates that variability in the scaling factors used for in vitro to in vivo extrapolation (IVIVE) for metabolic rate parameters can have a significant route-dependent impact on estimates of internal dose under environmentally relevant exposure scenarios. This indicates the need to evaluate both uncertainty and variability for scaling factors used for IVIVE. Sca

Internal noise estimates correlate with autistic traits.

PubMed

Vilidaite, Greta; Yu, Miaomiao; Baker, Daniel H

2017-08-01

Previous neuroimaging research has reported increased internal (neural) noise in sensory systems of autistic individuals. However, it is unclear if this difference has behavioural or perceptual consequences, as previous attempts at measuring internal noise in ASD psychophysically have been indirect. Here, we use a "gold standard" psychophysical double-pass paradigm to investigate the relationship between internal noise and autistic traits in the neurotypical population (n = 43). We measured internal noise in three tasks (contrast perception, facial expression intensity perception, and number summation) to estimate a global internal noise factor using principal components analysis. This global internal noise was positively correlated with autistic traits (r s  = 0.32, P = 0.035). This suggests that increased internal noise is associated with the ASD phenotype even in subclinical populations. The finding is discussed in relation to the neural and genetic basis of internal noise in ASD. Autism Res 2017, 10: 1384-1391. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Uncertainties of Mayak urine data

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

Miller, Guthrie; Vostrotin, Vadim; Vvdensky, Vladimir

2008-01-01

For internal dose calculations for the Mayak worker epidemiological study, quantitative estimates of uncertainty of the urine measurements are necessary. Some of the data consist of measurements of 24h urine excretion on successive days (e.g. 3 or 4 days). In a recent publication, dose calculations were done where the uncertainty of the urine measurements was estimated starting from the statistical standard deviation of these replicate mesurements. This approach is straightforward and accurate when the number of replicate measurements is large, however, a Monte Carlo study showed it to be problematic for the actual number of replicate measurements (median from 3more » to 4). Also, it is sometimes important to characterize the uncertainty of a single urine measurement. Therefore this alternate method has been developed. A method of parameterizing the uncertainty of Mayak urine bioassay measmements is described. The Poisson lognormal model is assumed and data from 63 cases (1099 urine measurements in all) are used to empirically determine the lognormal normalization uncertainty, given the measurement uncertainties obtained from count quantities. The natural logarithm of the geometric standard deviation of the normalization uncertainty is found to be in the range 0.31 to 0.35 including a measurement component estimated to be 0.2.« less

Seismic b-value anomalies prior to the 3rd January 2016, Mw = 6.7 Manipur earthquake of northeast India

NASA Astrophysics Data System (ADS)

Borgohain, Jayanta Madhab; Borah, Kajaljyoti; Biswas, Rajib; Bora, Dipok K.

2018-04-01

Spatial variation of seismic b-value is estimated in the Indo-Myanmar subduction zone of northeast (NE) India using the homogeneous part of earthquake catalogue (1996-2015), recorded by International Seismological Center (ISC), consisting of 895 events of magnitude MW ≥ 3.9. The study region is divided into 1° × 1° square grids and b-values are estimated at each grid by maximum likelihood method. In this study, the b-value varies from 0.75 to 1.54 in the region. Significant variation of low b-value in the respective location may indicate high stress accumulation in that region. Spatial variation reveals intermediate b-value anomalies around the epicenter of the Mw = 6.7 Manipur earthquake which occurred on 3rd January at 23:05 UTC (4 January 2016 at 04:35 IST). The variations of b-values are also estimated with respect to depth. The low b-value associated with the depth range ∼15-55 km, which may imply crustal homogeneity and high stress accumulation in the crust. Since, NE India lies in the seismic zone V of the country; this study can be helpful to understand seismotectonics in the region.

Pseudo and conditional score approach to joint analysis of current count and current status data.

PubMed

Wen, Chi-Chung; Chen, Yi-Hau

2018-04-17

We develop a joint analysis approach for recurrent and nonrecurrent event processes subject to case I interval censorship, which are also known in literature as current count and current status data, respectively. We use a shared frailty to link the recurrent and nonrecurrent event processes, while leaving the distribution of the frailty fully unspecified. Conditional on the frailty, the recurrent event is assumed to follow a nonhomogeneous Poisson process, and the mean function of the recurrent event and the survival function of the nonrecurrent event are assumed to follow some general form of semiparametric transformation models. Estimation of the models is based on the pseudo-likelihood and the conditional score techniques. The resulting estimators for the regression parameters and the unspecified baseline functions are shown to be consistent with rates of square and cubic roots of the sample size, respectively. Asymptotic normality with closed-form asymptotic variance is derived for the estimator of the regression parameters. We apply the proposed method to a fracture-osteoporosis survey data to identify risk factors jointly for fracture and osteoporosis in elders, while accounting for association between the two events within a subject. © 2018, The International Biometric Society.

Thermodynamic properties of selected uranium compounds and aqueous species at 298.15 K and 1 bar and at higher temperatures; preliminary models for the origin of coffinite deposits

USGS Publications Warehouse

Hemingway, B.S.

1982-01-01

Thermodynamic values for 110 uranium-bearing phases and 28 aqueous uranium solution species (298.15 K and l bar) are tabulated based upon evaluated experimental data (largely from calorimetric experiments) and estimated values. Molar volume data are given for most of the solid phases. Thermodynamic values for 16 uranium-bearing phases are presented for higher temperatures in the form of and as a supplement to U.S. Geological Survey Bulletin 1452 (Robie et al., 1979). The internal consistency of the thermodynamic values reported herein is dependent upon the reliability of the experimental results for several uranium phases that have been used as secondary calorimetric reference phases. The data for the reference phases and for those phases evaluated with respect to the secondary reference phases are discussed. A preliminary model for coffinite formation has been proposed together with an estimate of the free energy of formation of coffinite. Free energy values are estimated for several other uranium-bearing silicate phases that have been reported as secondary uranium phases associated with uranium ore deposits and that could be expected to develop wherever uranium is leached by groundwaters.

Method for solving the problem of nonlinear heating a cylindrical body with unknown initial temperature

NASA Astrophysics Data System (ADS)

Yaparova, N.

2017-10-01

We consider the problem of heating a cylindrical body with an internal thermal source when the main characteristics of the material such as specific heat, thermal conductivity and material density depend on the temperature at each point of the body. We can control the surface temperature and the heat flow from the surface inside the cylinder, but it is impossible to measure the temperature on axis and the initial temperature in the entire body. This problem is associated with the temperature measurement challenge and appears in non-destructive testing, in thermal monitoring of heat treatment and technical diagnostics of operating equipment. The mathematical model of heating is represented as nonlinear parabolic PDE with the unknown initial condition. In this problem, both the Dirichlet and Neumann boundary conditions are given and it is required to calculate the temperature values at the internal points of the body. To solve this problem, we propose the numerical method based on using of finite-difference equations and a regularization technique. The computational scheme involves solving the problem at each spatial step. As a result, we obtain the temperature function at each internal point of the cylinder beginning from the surface down to the axis. The application of the regularization technique ensures the stability of the scheme and allows us to significantly simplify the computational procedure. We investigate the stability of the computational scheme and prove the dependence of the stability on the discretization steps and error level of the measurement results. To obtain the experimental temperature error estimates, computational experiments were carried out. The computational results are consistent with the theoretical error estimates and confirm the efficiency and reliability of the proposed computational scheme.

Multilevel Modeling with Correlated Effects

ERIC Educational Resources Information Center

Kim, Jee-Seon; Frees, Edward W.

2007-01-01

When there exist omitted effects, measurement error, and/or simultaneity in multilevel models, explanatory variables may be correlated with random components, and standard estimation methods do not provide consistent estimates of model parameters. This paper introduces estimators that are consistent under such conditions. By employing generalized…

Psychometric evaluation of a new instrument in Spanish to measure the wellness of university nursing faculty.

PubMed

Hurtado-Pardos, Barbara; Casas, Irma; Lluch-Canut, Teresa; Moreno-Arroyo, Carmen; Nebot-Bergua, Carlos; Roldán-Merino, Juan

2018-01-02

The aim of this study was to design and validate an instrument to measure the wellness among university nursing faculty. The study was performed in two phases. Phase I consisted of the development of the instrument with discussion groups and participant consensus. We designed an instrument including the 21 items or psychosocial risk factors identified and estimated an index by evaluating the frequency and intensity of each item. The items were grouped into 3 dimensions: teaching work demands, curricular demands, and organizational difficulties. Phase II, we evaluated the psychometric properties of the tool in a sample of 263 participants. Exploratory factor analysis showed a 3-factor structure that explained 53% of the total variance. The internal consistency of the instrument was 0.91 for the whole instrument. The results indicate that the tool developed is valid and reliable and may be a good instrument to monitor the wellness of university nursing faculty.

A generic biokinetic model for noble gases with application to radon.

PubMed

Leggett, Rich; Marsh, James; Gregoratto, Demetrio; Blanchardon, Eric

2013-06-01

To facilitate the estimation of radiation doses from intake of radionuclides, the International Commission on Radiological Protection (ICRP) publishes dose coefficients (dose per unit intake) based on reference biokinetic and dosimetric models. The ICRP generally has not provided biokinetic models or dose coefficients for intake of noble gases, but plans to provide such information for (222)Rn and other important radioisotopes of noble gases in a forthcoming series of reports on occupational intake of radionuclides (OIR). This paper proposes a generic biokinetic model framework for noble gases and develops parameter values for radon. The framework is tailored to applications in radiation protection and is consistent with a physiologically based biokinetic modelling scheme adopted for the OIR series. Parameter values for a noble gas are based largely on a blood flow model and physical laws governing transfer of a non-reactive and soluble gas between materials. Model predictions for radon are shown to be consistent with results of controlled studies of its biokinetics in human subjects.

Consistency of Post-Newtonian Waveforms with Numerical Relativity

NASA Technical Reports Server (NTRS)

Baker, John G.; vanMeter, James R.; McWilliams, Sean T.; Centrella, Joan; Kelly, Bernard J.

2007-01-01

General relativity predicts the gravitational radiation signatures of mergers of compact binaries,such as coalescing binary black hole systems. Derivations of waveform predictions for such systems are required for optimal scientific analysis of observational gravitational wave data, and have so far been achieved primarily with the aid of the post-Newtonian (PN) approximation. The quaIity of this treatment is unclear, however, for the important late inspiral portion. We derive late-inspiral wave forms via a complementary approach, direct numerical simulation of Einstein's equations, which has recently matured sufficiently for such applications. We compare waveform phasing from simulations covering the last approximately 14 cycles of gravitational radiation from an equal-mass binary system of nonspinning black holes with corresponding 3PN and 3.5PN waveforms. We find phasing agreement consistent with internal error estimates based in either approach, at the level of one radian over approximately 10 cycles. The result suggests that PN waveforms for this system are effective roughly until the system reaches its last stable orbit just prior to the final merger.

Consistency of Post-Newtonian Waveforms with Numerical Relativity

NASA Technical Reports Server (NTRS)

Baker, John G.; vanMeter, James R.; McWilliams, Sean T.; Cewntrella, Joan; Kelly, Bernard J.

2006-01-01

General relativity predicts the gravitational radiation signatures of mergers of compact binaries, such as coalescing binary black hole systems. Derivations of waveform predictions for such systems are required for optimal scientific analysis of observational gravitational wave data, and have so far been achieved primarily with the aid of the post-Newtonian (PN) approximation. The quality of this treatment is unclear, however, for the important late inspiral portion. We derive late-inspiral waveforms via a complementary approach, direct numerical simulation of Einstein's equations, which has recently matured sufficiently for such applications. We compare waveform phasing from simulations covering the last approximately 14 cycles of gravitational radiation from an equal-mass binary system of nonspinning black holes with the corresponding 3PN and 3.5PN orbital phasing. We find agreement consistent with internal error estimates based on either approach at the level of one radian over approximately 10 cycles. The result suggests that PN waveforms for this system are effective roughly until the system reaches its last stable orbit just prior to the final merger/

Pore dimensions and the role of occupancy in unitary conductance of Shaker K channels

PubMed Central

Díaz-Franulic, Ignacio; Sepúlveda, Romina V.; Navarro-Quezada, Nieves; González-Nilo, Fernando

2015-01-01

K channels mediate the selective passage of K+ across the plasma membrane by means of intimate interactions with ions at the pore selectivity filter located near the external face. Despite high conservation of the selectivity filter, the K+ transport properties of different K channels vary widely, with the unitary conductance spanning a range of over two orders of magnitude. Mutation of Pro475, a residue located at the cytoplasmic entrance of the pore of the small-intermediate conductance K channel Shaker (Pro475Asp (P475D) or Pro475Gln (P475Q)), increases Shaker’s reported ∼20-pS conductance by approximately six- and approximately threefold, respectively, without any detectable effect on its selectivity. These findings suggest that the structural determinants underlying the diversity of K channel conductance are distinct from the selectivity filter, making P475D and P475Q excellent probes to identify key determinants of the K channel unitary conductance. By measuring diffusion-limited unitary outward currents after unilateral addition of 2 M sucrose to the internal solution to increase its viscosity, we estimated a pore internal radius of capture of ∼0.82 Å for all three Shaker variants (wild type, P475D, and P475Q). This estimate is consistent with the internal entrance of the Kv1.2/2.1 structure if the effective radius of hydrated K+ is set to ∼4 Å. Unilateral exposure to sucrose allowed us to estimate the internal and external access resistances together with that of the inner pore. We determined that Shaker resistance resides mainly in the inner cavity, whereas only ∼8% resides in the selectivity filter. To reduce the inner resistance, we introduced additional aspartate residues into the internal vestibule to favor ion occupancy. No aspartate addition raised the maximum unitary conductance, measured at saturating [K+], beyond that of P475D, suggesting an ∼200-pS conductance ceiling for Shaker. This value is approximately one third of the maximum conductance of the large conductance K (BK) channel (the K channel of highest conductance), reducing the energy gap between their K+ transport rates to ∼1 kT. Thus, although Shaker’s pore sustains ion translocation as the BK channel’s does, higher energetic costs of ion stabilization or higher friction with the ion’s rigid hydration cage in its narrower aqueous cavity may entail higher resistance. PMID:26216859

Bias and robustness of uncertainty components estimates in transient climate projections

NASA Astrophysics Data System (ADS)

Hingray, Benoit; Blanchet, Juliette; Jean-Philippe, Vidal

2016-04-01

A critical issue in climate change studies is the estimation of uncertainties in projections along with the contribution of the different uncertainty sources, including scenario uncertainty, the different components of model uncertainty and internal variability. Quantifying the different uncertainty sources faces actually different problems. For instance and for the sake of simplicity, an estimate of model uncertainty is classically obtained from the empirical variance of the climate responses obtained for the different modeling chains. These estimates are however biased. Another difficulty arises from the limited number of members that are classically available for most modeling chains. In this case, the climate response of one given chain and the effect of its internal variability may be actually difficult if not impossible to separate. The estimate of scenario uncertainty, model uncertainty and internal variability components are thus likely to be not really robust. We explore the importance of the bias and the robustness of the estimates for two classical Analysis of Variance (ANOVA) approaches: a Single Time approach (STANOVA), based on the only data available for the considered projection lead time and a time series based approach (QEANOVA), which assumes quasi-ergodicity of climate outputs over the whole available climate simulation period (Hingray and Saïd, 2014). We explore both issues for a simple but classical configuration where uncertainties in projections are composed of two single sources: model uncertainty and internal climate variability. The bias in model uncertainty estimates is explored from theoretical expressions of unbiased estimators developed for both ANOVA approaches. The robustness of uncertainty estimates is explored for multiple synthetic ensembles of time series projections generated with MonteCarlo simulations. For both ANOVA approaches, when the empirical variance of climate responses is used to estimate model uncertainty, the bias is always positive. It can be especially high with STANOVA. In the most critical configurations, when the number of members available for each modeling chain is small (< 3) and when internal variability explains most of total uncertainty variance (75% or more), the overestimation is higher than 100% of the true model uncertainty variance. The bias can be considerably reduced with a time series ANOVA approach, owing to the multiple time steps accounted for. The longer the transient time period used for the analysis, the larger the reduction. When a quasi-ergodic ANOVA approach is applied to decadal data for the whole 1980-2100 period, the bias is reduced by a factor 2.5 to 20 depending on the projection lead time. In all cases, the bias is likely to be not negligible for a large number of climate impact studies resulting in a likely large overestimation of the contribution of model uncertainty to total variance. For both approaches, the robustness of all uncertainty estimates is higher when more members are available, when internal variability is smaller and/or the response-to-uncertainty ratio is higher. QEANOVA estimates are much more robust than STANOVA ones: QEANOVA simulated confidence intervals are roughly 3 to 5 times smaller than STANOVA ones. Excepted for STANOVA when less than 3 members is available, the robustness is rather high for total uncertainty and moderate for internal variability estimates. For model uncertainty or response-to-uncertainty ratio estimates, the robustness is conversely low for QEANOVA to very low for STANOVA. In the most critical configurations (small number of member, large internal variability), large over- or underestimation of uncertainty components is very thus likely. To propose relevant uncertainty analyses and avoid misleading interpretations, estimates of uncertainty components should be therefore bias corrected and ideally come with estimates of their robustness. This work is part of the COMPLEX Project (European Collaborative Project FP7-ENV-2012 number: 308601; http://www.complex.ac.uk/). Hingray, B., Saïd, M., 2014. Partitioning internal variability and model uncertainty components in a multimodel multireplicate ensemble of climate projections. J.Climate. doi:10.1175/JCLI-D-13-00629.1 Hingray, B., Blanchet, J. (revision) Unbiased estimators for uncertainty components in transient climate projections. J. Climate Hingray, B., Blanchet, J., Vidal, J.P. (revision) Robustness of uncertainty components estimates in climate projections. J.Climate

International Psychometric Validation of an EORTC Quality of Life Module Measuring Cancer Related Fatigue (EORTC QLQ-FA12).

PubMed

Weis, Joachim; Tomaszewski, Krzysztof A; Hammerlid, Eva; Ignacio Arraras, Juan; Conroy, Thierry; Lanceley, Anne; Schmidt, Heike; Wirtz, Markus; Singer, Susanne; Pinto, Monica; Alm El-Din, Mohamed; Compter, Inge; Holzner, Bernhard; Hofmeister, Dirk; Chie, Wei-Chu; Czeladzki, Marek; Harle, Amelie; Jones, Louise; Ritter, Sabrina; Flechtner, Hans-Henning; Bottomley, Andrew

2017-05-01

The European Organisation for Research and Treatment of Cancer (EORTC) Group has developed a new multidimensional instrument measuring cancer-related fatigue to be used in conjunction with the quality of life core questionnaire (EORTC QLQ-C30). The module EORTC QLQ-FA13 assesses physical, cognitive, and emotional aspects of cancer-related fatigue. The methodology follows the EORTC guidelines for phase IV validation of modules. This paper focuses on the results of the psychometric validation of the factorial structure of the module. For validation and cross-validation confirmatory factor analysis (maximum likelihood estimation), intraclass correlation and Cronbach alpha for internal consistency were employed. The study involved an international multicenter collaboration of 11 European and non-European countries. A total of 946 patients with various tumor diagnoses were enrolled. Based on the confirmatory factor analysis, we could approve the three-dimensional structure of the module. Removing one item and reassigning the factorial mapping of another item resulted in the EORTC QLQ-FA12. For the revised scale, we found evidence supporting good local (indicator reliability ≥ 0.60, factor reliability ≥ 0.82) and global model fit (GFI t1|t2 = 0.965/0.957, CFI t1|t2 = 0.976/0.972, RMSEA t1|t2 = 0.060/0.069) for both measurement points. For each scale, test-retest reliability proved to be very good (intraclass correlation: R t1-t2 = 0.905-0.921) and internal consistency proved to be good to high (Cronbach alpha = .79-.90). Based on the former phase III module, the multidimensional structure was revised as a phase IV module (EORTC FA12) with an improved scale structure. For a comprehensive validation of the EORTC FA12, further aspects of convergent and divergent validity as well as sensitivity to change should be determined. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Seismic reflection imaging, accounting for primary and multiple reflections

NASA Astrophysics Data System (ADS)

Wapenaar, Kees; van der Neut, Joost; Thorbecke, Jan; Broggini, Filippo; Slob, Evert; Snieder, Roel

2015-04-01

Imaging of seismic reflection data is usually based on the assumption that the seismic response consists of primary reflections only. Multiple reflections, i.e. waves that have reflected more than once, are treated as primaries and are imaged at wrong positions. There are two classes of multiple reflections, which we will call surface-related multiples and internal multiples. Surface-related multiples are those multiples that contain at least one reflection at the earth's surface, whereas internal multiples consist of waves that have reflected only at subsurface interfaces. Surface-related multiples are the strongest, but also relatively easy to deal with because the reflecting boundary (the earth's surface) is known. Internal multiples constitute a much more difficult problem for seismic imaging, because the positions and properties of the reflecting interfaces are not known. We are developing reflection imaging methodology which deals with internal multiples. Starting with the Marchenko equation for 1D inverse scattering problems, we derived 3D Marchenko-type equations, which relate reflection data at the surface to Green's functions between virtual sources anywhere in the subsurface and receivers at the surface. Based on these equations, we derived an iterative scheme by which these Green's functions can be retrieved from the reflection data at the surface. This iterative scheme requires an estimate of the direct wave of the Green's functions in a background medium. Note that this is precisely the same information that is also required by standard reflection imaging schemes. However, unlike in standard imaging, our iterative Marchenko scheme retrieves the multiple reflections of the Green's functions from the reflection data at the surface. For this, no knowledge of the positions and properties of the reflecting interfaces is required. Once the full Green's functions are retrieved, reflection imaging can be carried out by which the primaries and multiples are mapped to their correct positions, with correct reflection amplitudes. In the presentation we will illustrate this new methodology with numerical examples and discuss its potential and limitations.

ANALYSIS OF EPR AND FISH STUDIES OF RADIATION DOSES IN PERSONS WHO LIVED IN THE UPPER REACHES OF THE TECHA RIVER

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

Degteva, M. O.; Shagina, N. B.; Shishkina, Elena A.

Waterborne radioactive releases into the Techa River from the Mayak Production Association in Russia during 1949–1956 resulted in significant doses to about 30,000 persons who lived in downstream settlements. The residents were exposed to internal and external radiation. Two methods for reconstruction of the external dose are considered in this paper, electron paramagnetic resonance (EPR) measurements of teeth and fluorescence in situ hybridization (FISH) measurements of chromosome translocations in circulating lymphocytes. The main issue in the application of the EPR and FISH methods for reconstruction of the external dose for the Techa Riverside residents was strontium radioisotopes incorporated in teethmore » and bones that served as a source of confounding local exposures. In order to estimate and subtract doses from incorporated 89,90Sr, the EPR and FISH assays were supported by measurements of 90Sr-body burdens and estimates of 90Sr concentrations in dental tissues by the luminescence method. The resulting dose estimates derived from EPR and FISH measurements for residents of the upper Techa River were found to be consistent: the mean values vary from 510 – 550 mGy for the villages located close to the site of radioactive release to 130 – 160 mGy for the more distant villages. The upper bound of individual estimates for both methods is equal to 2.2 – 2.3 Gy. The EPR- and FISH-based dose estimates were compared with the doses calculated for the donors using the Techa River Dosimetry System (TRDS). The TRDS external dose assessments were based on the data on contamination of the Techa River floodplain, simulation of ai r kerma above the contaminated soil, age-dependent life-styles and individual residence histories. For correct comparison TRDS-based doses were calculated from two sources: external exposure from the contaminated environment and internal exposure from 137Cs incorporated in donors’ soft tissues. The TRDS-based absorbed doses in tooth enamel and muscle were in agreement with with EPR- and FISH-based estimates within uncertainty bounds. Basically, the agreement between the estimates has confirmed the validity of external doses calculated with the Techa River Dosimetry System.« less

Identifying the Community Structure of the Food-Trade International Multi-Network

NASA Technical Reports Server (NTRS)

Torreggiani, S.; Mangioni, G.

2018-01-01

Achieving international food security requires improved understanding of how international trade networks connect countries around the world through the import-export flows of food commodities. The properties of international food trade networks are still poorly documented, especially from a multi-network perspective. In particular, nothing is known about the multi-network's community structure. Here we find that the individual crop-specific layers of the multi-network have densely connected trading groups, a consistent characteristic over the period 2001-2011. Further, the multi-network is characterized by low variability over this period but with substantial heterogeneity across layers in each year. In particular, the layers are mostly assortative: more-intensively connected countries tend to import from and export to countries that are themselves more connected. We also fit econometric models to identify social, economic and geographic factors explaining the probability that any two countries are co-present in the same community. Our estimates indicate that the probability of country pairs belonging to the same food trade community depends more on geopolitical and economic factors-such as geographical proximity and trade-agreement co-membership-than on country economic size and/or income. These community-structure findings of the multi-network are especially valuable for efforts to understand past and emerging dynamics in the global food system, especially those that examine potential 'shocks' to global food trade.

Identifying the community structure of the food-trade international multi-network

NASA Astrophysics Data System (ADS)

Torreggiani, S.; Mangioni, G.; Puma, M. J.; Fagiolo, G.

2018-05-01

Achieving international food security requires improved understanding of how international trade networks connect countries around the world through the import-export flows of food commodities. The properties of international food trade networks are still poorly documented, especially from a multi-network perspective. In particular, nothing is known about the multi-network’s community structure. Here we find that the individual crop-specific layers of the multi-network have densely connected trading groups, a consistent characteristic over the period 2001–2011. Further, the multi-network is characterized by low variability over this period but with substantial heterogeneity across layers in each year. In particular, the layers are mostly assortative: more-intensively connected countries tend to import from and export to countries that are themselves more connected. We also fit econometric models to identify social, economic and geographic factors explaining the probability that any two countries are co-present in the same community. Our estimates indicate that the probability of country pairs belonging to the same food trade community depends more on geopolitical and economic factors—such as geographical proximity and trade-agreement co-membership—than on country economic size and/or income. These community-structure findings of the multi-network are especially valuable for efforts to understand past and emerging dynamics in the global food system, especially those that examine potential ‘shocks’ to global food trade.

26 CFR 1.6654-5 - Payments of estimated tax.

Code of Federal Regulations, 2010 CFR

2010-04-01

....6654-5 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Additions to the Tax, Additional Amounts, and Assessable Penalties § 1.6654-5... on Form 1040-ES. For the purpose of determining the estimated tax, the amount of gross income which...

Development and Validation of the Bicultural Youth Acculturation Questionnaire

PubMed Central

Kukaswadia, Atif; Janssen, Ian; Pickett, William; Bajwa, Jasmine; Georgiades, Katholiki; Lalonde, Richard N.; Quon, Elizabeth C.; Safdar, Saba; Pike, Ian

2016-01-01

Objectives Acculturation is a multidimensional process involving changes in behaviour and beliefs. Questionnaires developed to measure acculturation are typically designed for specific ethnic populations and adult experiences. This study developed a questionnaire that measures acculturation among ethnically diverse populations of youth that can be included as a module in population surveys. Methods Questionnaires measuring acculturation in youth were identified in the literature. The importance of items from the existing questionnaires was determined using a Delphi process and this informed the development of our questionnaire. The questionnaire was then pilot tested using a sample of 248 Canadians aged 18–25 via an online system. Participants identified as East and South East Asian (27.8%), South Asian (17.7%) and Black (13.7%). The majority were 1st (33.5%) or 2nd generation immigrants (52.0%). After redundant items were eliminated, exploratory factor analysis grouped items into domains, and, for each domain, internal consistency, and convergent validity with immigrant generation then age at immigration estimated. A subset of participants re-completed the questionnaire for reliability estimation. Results The literature review yielded 117 articles that used 13 questionnaires with a total of 440 questions. The Delphi process reduced these to 32 questions. Pilot testing occurred in 248 Canadians aged 18–25. Following item reduction, 16 questions in three domains remained: dominant culture, heritage language, and heritage culture. All had good internal consistency (Cronbach’s alphas > .75). The mean dominant domain score increased with immigrant generation (1st generation: 3.69 (95% CI: 3.49–3.89), 2nd: 4.13 (4.00–4.26), 3rd: 4.40 (4.19–4.61)), and mean heritage language score was higher among those who immigrated after age 12 than before (p = .0001), indicative of convergent validity. Conclusions This Bicultural Youth Acculturation Questionnaire has demonstrated validity. It can be incorporated into population health surveys to elucidate the impact of acculturation on health outcomes among bicultural youth. PMID:27557080

Development and Validation of the Bicultural Youth Acculturation Questionnaire.

PubMed

Kukaswadia, Atif; Janssen, Ian; Pickett, William; Bajwa, Jasmine; Georgiades, Katholiki; Lalonde, Richard N; Quon, Elizabeth C; Safdar, Saba; Pike, Ian

2016-01-01

Acculturation is a multidimensional process involving changes in behaviour and beliefs. Questionnaires developed to measure acculturation are typically designed for specific ethnic populations and adult experiences. This study developed a questionnaire that measures acculturation among ethnically diverse populations of youth that can be included as a module in population surveys. Questionnaires measuring acculturation in youth were identified in the literature. The importance of items from the existing questionnaires was determined using a Delphi process and this informed the development of our questionnaire. The questionnaire was then pilot tested using a sample of 248 Canadians aged 18-25 via an online system. Participants identified as East and South East Asian (27.8%), South Asian (17.7%) and Black (13.7%). The majority were 1st (33.5%) or 2nd generation immigrants (52.0%). After redundant items were eliminated, exploratory factor analysis grouped items into domains, and, for each domain, internal consistency, and convergent validity with immigrant generation then age at immigration estimated. A subset of participants re-completed the questionnaire for reliability estimation. The literature review yielded 117 articles that used 13 questionnaires with a total of 440 questions. The Delphi process reduced these to 32 questions. Pilot testing occurred in 248 Canadians aged 18-25. Following item reduction, 16 questions in three domains remained: dominant culture, heritage language, and heritage culture. All had good internal consistency (Cronbach's alphas > .75). The mean dominant domain score increased with immigrant generation (1st generation: 3.69 (95% CI: 3.49-3.89), 2nd: 4.13 (4.00-4.26), 3rd: 4.40 (4.19-4.61)), and mean heritage language score was higher among those who immigrated after age 12 than before (p = .0001), indicative of convergent validity. This Bicultural Youth Acculturation Questionnaire has demonstrated validity. It can be incorporated into population health surveys to elucidate the impact of acculturation on health outcomes among bicultural youth.

Demoralization Scale in Spanish-Speaking Palliative Care Patients.

PubMed

Rudilla, David; Galiana, Laura; Oliver, Amparo; Barreto, Pilar

2016-04-01

Among the approaches to the demoralization syndrome, the one proposed by Kissane et al. is prevalent in the literature. These authors developed the Demoralization Scale (DS) to assess emotional distress, conceived as demoralization. To present the Spanish adaptation of the Demoralization Scale in palliative care patients, with a new and more comprehensive approach to its factorial structure. A cross-sectional study was carried out in 226 Spanish palliative care patients in three different settings: hospital, home care unit, and continued care unit. Outcome measures included the DS and the Hospital Anxiety and Depression Scale. Analyses comprised confirmatory factor analyses to test the original, German, and Irish structure of the DS, exploratory structural equation modeling (ESEM), estimations of internal consistency, and multivariate analyses of variance for criterion-related validity. The confirmatory factor analyses showed inappropriate fit for the previous structures when studied in the Spanish version of the DS. With ESEM, the best fitting structure was the five-factor solution, without item 18. Reliability results offered good estimations of internal consistency for all the dimensions except for sense of failure. Cronbach alpha coefficients were appropriate for the dimensions of loss of meaning (0.86), helplessness (0.79), disheartenment (0.88), and dysphoria (0.80), but low reliability was found for sense of failure (0.62). Convergent and discriminant validity showed positive correlations between demoralization, anxiety, and depression. Patients with higher levels of anxiety had higher scores on every dimension of demoralization, and those with higher levels of depression had higher scores on loss of meaning, disheartenment, and sense of failure, but not on dysphoria or helplessness. The Spanish adaptation of the DS has shown appropriate psychometric properties. It has been useful to differentiate between depression and the demoralization syndrome, pointing to helplessness and dysphoria as unique characteristics of demoralized palliative care patients. Copyright © 2016. Published by Elsevier Inc.

Development and validation of the Rapid Estimate of Adolescent Literacy in Medicine (REALM-Teen): a tool to screen adolescents for below-grade reading in health care settings.

PubMed

Davis, Terry C; Wolf, Michael S; Arnold, Connie L; Byrd, Robert S; Long, Sandra W; Springer, Thomas; Kennen, Estela; Bocchini, Joseph A

2006-12-01

The magnitude and consequences of low literacy in adolescent health and health care are unknown. The purpose of this study was to validate the Rapid Estimate of Adolescent Literacy in Medicine (REALM-Teen), a word-recognition test in English that can be used as a brief literacy-screening tool in health care settings. A total of 1533 adolescents aged 10 to 19 years attending 1 of 5 middle schools, 3 high schools, 1 pediatric clinic, or 2 summer programs in Louisiana and North Carolina participated in face-to-face interviews. Demographic information was solicited, and participants were administered a battery of reading tests, including the REALM-Teen, Wide Range Achievement Test-Revised (WRAT-3), and Slosson Oral Reading Test-Revised (SORT-R). Internal consistency for the REALM-Teen was determined using Cronbach's alpha, and criterion validity was established through correlations with both the WRAT-R and SORT-R. Using reading below grade level (according to SORT-R scores) as an outcome, instrument accuracy and corresponding cutoff scores were calculated by plotting receiver operating characteristic curves and stratum-specific likelihood ratios. Participants were 50% black and 53% female; 34% were enrolled in middle school and 66% in high school. The average time required to administer the REALM-Teen was 3 minutes. Internal consistency was excellent, as was test-retest reliability. The REALM-Teen is strongly correlated with both the WRAT-R and SORT-R. Five reading level categories were identified: 3rd grade and below, 4th to 5th grade, 6th to 7th grade, 8th to 9th grade, and 10th grade and above. Forty-six percent of participants were reading below grade level according to the SORT-R and 28% had repeated at least 1 grade. The REALM-Teen is a brief, reliable instrument for assessing adolescent literacy skills and reading below grade level.

Internal displacement and the Syrian crisis: an analysis of trends from 2011-2014.

PubMed

Doocy, Shannon; Lyles, Emily; Delbiso, Tefera D; Robinson, Courtland W

2015-01-01

Since the start of the Syrian crisis in 2011, civil unrest and armed conflict in the country have resulted in a rapidly increasing number of people displaced both within and outside of Syria. Those displaced face immense challenges in meeting their basic needs. This study sought to characterize internal displacement in Syria, including trends in both time and place, and to provide insights on the association between displacement and selected measures of household well-being and humanitarian needs. This study presents findings from two complementary methods: a desk review of displaced population estimates and movements and a needs assessment of 3930 Syrian households affected by the crisis. The first method, a desk review of displaced population estimates and movements, provides a retrospective analysis of national trends in displacement from March 2011 through June 2014. The second method, analysis of findings from a 2014 needs assessment by displacement status, provides insight into the displaced population and the association between displacement and humanitarian needs. Findings indicate that while displacement often corresponds to conflict levels, such trends were not uniformly observed in governorate-level analysis. Governorate level IDP estimates do not provide information on a scale detailed enough to adequately plan humanitarian assistance. Furthermore, such estimates are often influenced by obstructed access to certain areas, unsubstantiated reports, and substantial discrepancies in reporting. Secondary displacement is not consistently reported across sources nor are additional details about displacement, including whether displaced individuals originated within the current governorate or outside of the governorate. More than half (56.4 %) of households reported being displaced more than once, with a majority displaced for more than one year (73.3 %). Some differences between displaced and non-displaced population were observed in residence crowding, food consumption, health access, and education. Differences in reported living conditions and key health, nutrition, and education indicators between displaced and non-displaced populations indicate a need to better understand migration trends in order to inform planning and provision of live saving humanitarian assistance.

Reliability and Validity of Instruments for Assessing Perinatal Depression in African Settings: Systematic Review and Meta-Analysis

PubMed Central

Tsai, Alexander C.; Scott, Jennifer A.; Hung, Kristin J.; Zhu, Jennifer Q.; Matthews, Lynn T.; Psaros, Christina; Tomlinson, Mark

2013-01-01

Background A major barrier to improving perinatal mental health in Africa is the lack of locally validated tools for identifying probable cases of perinatal depression or for measuring changes in depression symptom severity. We systematically reviewed the evidence on the reliability and validity of instruments to assess perinatal depression in African settings. Methods and Findings Of 1,027 records identified through searching 7 electronic databases, we reviewed 126 full-text reports. We included 25 unique studies, which were disseminated in 26 journal articles and 1 doctoral dissertation. These enrolled 12,544 women living in nine different North and sub-Saharan African countries. Only three studies (12%) used instruments developed specifically for use in a given cultural setting. Most studies provided evidence of criterion-related validity (20 [80%]) or reliability (15 [60%]), while fewer studies provided evidence of construct validity, content validity, or internal structure. The Edinburgh postnatal depression scale (EPDS), assessed in 16 studies (64%), was the most frequently used instrument in our sample. Ten studies estimated the internal consistency of the EPDS (median estimated coefficient alpha, 0.84; interquartile range, 0.71-0.87). For the 14 studies that estimated sensitivity and specificity for the EPDS, we constructed 2 x 2 tables for each cut-off score. Using a bivariate random-effects model, we estimated a pooled sensitivity of 0.94 (95% confidence interval [CI], 0.68-0.99) and a pooled specificity of 0.77 (95% CI, 0.59-0.88) at a cut-off score of ≥9, with higher cut-off scores yielding greater specificity at the cost of lower sensitivity. Conclusions The EPDS can reliably and validly measure perinatal depression symptom severity or screen for probable postnatal depression in African countries, but more validation studies on other instruments are needed. In addition, more qualitative research is needed to adequately characterize local understandings of perinatal depression-like syndromes in different African contexts. PMID:24340036

Interlaboratory evaluation of a standardized inductively coupled plasma mass spectrometry method for the determination of trace beryllium in air filter samples.

PubMed

Ashley, Kevin; Brisson, Michael J; Howe, Alan M; Bartley, David L

2009-12-01

A collaborative interlaboratory evaluation of a newly standardized inductively coupled plasma mass spectrometry (ICP-MS) method for determining trace beryllium in workplace air samples was carried out toward fulfillment of method validation requirements for ASTM International voluntary consensus standard test methods. The interlaboratory study (ILS) was performed in accordance with an applicable ASTM International standard practice, ASTM E691, which describes statistical procedures for investigating interlaboratory precision. Uncertainty was also estimated in accordance with ASTM D7440, which applies the International Organization for Standardization Guide to the Expression of Uncertainty in Measurement to air quality measurements. Performance evaluation materials (PEMs) used consisted of 37 mm diameter mixed cellulose ester filters that were spiked with beryllium at levels of 0.025 (low loading), 0.5 (medium loading), and 10 (high loading) microg Be/filter; these spiked filters were prepared by a contract laboratory. Participating laboratories were recruited from a pool of over 50 invitees; ultimately, 20 laboratories from Europe, North America, and Asia submitted ILS results. Triplicates of each PEM (blanks plus the three different loading levels) were conveyed to each volunteer laboratory, along with a copy of the draft standard test method that each participant was asked to follow; spiking levels were unknown to the participants. The laboratories were requested to prepare the PEMs by one of three sample preparation procedures (hotplate or microwave digestion or hotblock extraction) that were described in the draft standard. Participants were then asked to analyze aliquots of the prepared samples by ICP-MS and to report their data in units of mu g Be/filter sample. Interlaboratory precision estimates from participating laboratories, computed in accordance with ASTM E691, were 0.165, 0.108, and 0.151 (relative standard deviation) for the PEMs spiked at 0.025, 0.5, and 10 microg Be/filter, respectively. Overall recoveries were 93.2%, 102%, and 80.6% for the low, medium, and high beryllium loadings, respectively. Expanded uncertainty estimates for interlaboratory analysis of low, medium, and high beryllium loadings, calculated in accordance with ASTM D7440, were 18.8%, 19.8%, and 24.4%, respectively. These figures of merit support promulgation of the analytical procedure as an ASTM International standard test method, ASTM D7439.

Estimating Whether Replacing Time in Active Outdoor Play and Sedentary Video Games With Active Video Games Influences Youth's Mental Health.

PubMed

Janssen, Ian

2016-11-01

The primary objective was to use isotemporal substitution models to estimate whether replacing time spent in sedentary video games (SVGs) and active outdoor play (AOP) with active video games (AVGs) would be associated with changes in youth's mental health. A representative sample of 20,122 Canadian youth in Grades 6-10 was studied. The exposure variables were average hours/day spent playing AVGs, SVGs, and AOP. The outcomes consisted of a negative and internalizing mental health indicator (emotional problems), a positive and internalizing mental health indicator (life satisfaction), and a positive and externalizing mental health indicator (prosocial behavior). Isotemporal substitution models estimated the extent to which replacing time spent in SVGs and AOP with an equivalent amount of time in AVGs had on the mental health indicators. Replacing 1 hour/day of SVGs with 1 hour/day of AVGs was associated with a 6% (95% confidence interval: 3%-9%) reduced probability of high emotional problems, a 4% (2%-7%) increased probability of high life satisfaction, and a 13% (9%-16%) increased probability of high prosocial behavior. Replacing 1 hour/day of AOP with 1 hour/day of AVGs was associated with a 7% (3%-11%) increased probability of high emotional problems, a 3% (1%-5%) reduced probability of high life satisfaction, and a 6% (2%-9%) reduced probability of high prosocial behavior. Replacing SVGs with AVGs was associated with more preferable mental health indicators. Conversely, replacing AOP with AVGs was associated with more deleterious mental health indicators. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

An Estimate of the Incidence of Prostate Cancer in Africa: A Systematic Review and Meta-Analysis

PubMed Central

Aderemi, Adewale Victor; Iseolorunkanmi, Alexander; Oyedokun, Ayo; Ayo, Charles K.

2016-01-01

Background Prostate cancer (PCa) is rated the second most common cancer and sixth leading cause of cancer deaths among men globally. Reports show that African men suffer disproportionately from PCa compared to men from other parts of the world. It is still quite difficult to accurately describe the burden of PCa in Africa due to poor cancer registration systems. We systematically reviewed the literature on prostate cancer in Africa and provided a continent-wide incidence rate of PCa based on available data in the region. Methods A systematic literature search of Medline, EMBASE and Global Health from January 1980 to June 2015 was conducted, with additional search of Google Scholar, International Association of Cancer Registries (IACR), International Agency for Research on Cancer (IARC), and WHO African region websites, for studies that estimated incidence rate of PCa in any African location. Having assessed quality and consistency across selected studies, we extracted incidence rates of PCa and conducted a random effects meta-analysis. Results Our search returned 9766 records, with 40 studies spreading across 16 African countries meeting our selection criteria. We estimated a pooled PCa incidence rate of 22.0 (95% CI: 19.93–23.97) per 100,000 population, and also reported a median incidence rate of 19.5 per 100,000 population. We observed an increasing trend in PCa incidence with advancing age, and over the main years covered. Conclusion Effective cancer registration and extensive research are vital to appropriately quantifying PCa burden in Africa. We hope our findings may further assist at identifying relevant gaps, and contribute to improving knowledge, research, and interventions targeted at prostate cancer in Africa. PMID:27073921

International variation in the prevalence of preclinical colorectal cancer: Implications for predictive values of noninvasive screening tests and potential target populations for screening

PubMed Central

Stock, Christian; Brenner, Hermann

2017-01-01

Screening for colorectal cancer (CRC) is implemented in an increasing number of countries. We aimed to assess international variation in the prevalence of preclinical CRC and the resulting variation in positive and negative predictive values (PPVs, NPVs) of existing and potential CRC screening tests in various countries. Using age‐ and sex‐specific CRC incidence data and transition rates from preclinical to clinical CRC we estimated overall and age‐ and sex‐specific prevalence of preclinical CRC in the target population aged 50–74 years in different parts of the world. These prevalence estimates were used to derive PPVs and NPVs for existing and potential noninvasive screening tests with varying levels of sensitivity and specificity. Within all regions and countries, prevalence strongly increases with age and is higher in men than in women. In addition, major variation was seen between regions and countries, with overall prevalence varying between 1 and 0.1%. As a result, PPVs are expected to strongly vary between ∼10% for men in high incidence countries, such as Australia and Germany, and 1% for women in low incidence countries, whereas NPVs are expected to be consistently well above 99%. Variation in CRC prevalence profoundly affects expected PPVs of screening tests, and PPVs should be carefully considered when decisions on screening tests and strategies are made for specific populations and health care systems. Here, we provide estimates of preclinical CRC and expected PPVs and NPVs of noninvasive screening tests, which may enhance the empirical basis for planning of population‐based CRC screening strategies. PMID:28670788

Validation of the French version of the Burn Specific Health Scale-Brief (BSHS-B) questionnaire.

PubMed

Gandolfi, S; Auquit-Auckbur, I; Panunzi, S; Mici, E; Grolleau, J-L; Chaput, B

2016-11-01

The Burn Specific Health Scale-Brief questionnaire is a widely validated tool for estimating the health related quality of life and for assessing the best multidisciplinary management of burn patients. The aim of this study was to translate the BSHS-B into French and to investigate its reliability and validity. According to the procedure proposed by the Scientific Advisory Committee of the Medical Outcomes Trust, the Burn Specific Health Scale-Brief (BSHS-B) was translated from the English version into French. In order to test the reliability of the French version of the BSHS-B, 53 burn patients French speakers completed the BSHS-B and SF-36 questionnaires from two to four years after burn. Ten of them have been re-tested at 6 months after the first evaluation. To evaluate clinical utility of the BSHS-F, internal consistency, construct validity (using SF-36) and stability in time were assessed using Cronbach's alpha statistic, Spearman rank test, and intra-class correlation coefficient respectively. The French version of the BSHS-B Cronbach's alpha coefficient was 0.93 and was >0.80 for all the sub-domains. French version of the BSHS-B and the SF-36 were positively correlated, all the associations were statistically significant (p<0.01). Intra-class correlation coefficients for test-retest ranged between 0.95 and 0.99 for the sub-domains. The intra-class correlation coefficient (ICC) for the total score was 0.98. The French version of the BSHS-B shows a robust rate of internal consistency, construct validity and stability in time, supporting its application in routine clinical practice as well as in international studies. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Human blood metabolite timetable indicates internal body time

PubMed Central

Kasukawa, Takeya; Sugimoto, Masahiro; Hida, Akiko; Minami, Yoichi; Mori, Masayo; Honma, Sato; Honma, Ken-ichi; Mishima, Kazuo; Soga, Tomoyoshi; Ueda, Hiroki R.

2012-01-01

A convenient way to estimate internal body time (BT) is essential for chronotherapy and time-restricted feeding, both of which use body-time information to maximize potency and minimize toxicity during drug administration and feeding, respectively. Previously, we proposed a molecular timetable based on circadian-oscillating substances in multiple mouse organs or blood to estimate internal body time from samples taken at only a few time points. Here we applied this molecular-timetable concept to estimate and evaluate internal body time in humans. We constructed a 1.5-d reference timetable of oscillating metabolites in human blood samples with 2-h sampling frequency while simultaneously controlling for the confounding effects of activity level, light, temperature, sleep, and food intake. By using this metabolite timetable as a reference, we accurately determined internal body time within 3 h from just two anti-phase blood samples. Our minimally invasive, molecular-timetable method with human blood enables highly optimized and personalized medicine. PMID:22927403

A unified internal model theory to resolve the paradox of active versus passive self-motion sensation

PubMed Central

Angelaki, Dora E

2017-01-01

Brainstem and cerebellar neurons implement an internal model to accurately estimate self-motion during externally generated (‘passive’) movements. However, these neurons show reduced responses during self-generated (‘active’) movements, indicating that predicted sensory consequences of motor commands cancel sensory signals. Remarkably, the computational processes underlying sensory prediction during active motion and their relationship to internal model computations during passive movements remain unknown. We construct a Kalman filter that incorporates motor commands into a previously established model of optimal passive self-motion estimation. The simulated sensory error and feedback signals match experimentally measured neuronal responses during active and passive head and trunk rotations and translations. We conclude that a single sensory internal model can combine motor commands with vestibular and proprioceptive signals optimally. Thus, although neurons carrying sensory prediction error or feedback signals show attenuated modulation, the sensory cues and internal model are both engaged and critically important for accurate self-motion estimation during active head movements. PMID:29043978

Internal exposure to neutron-activated 56Mn dioxide powder in Wistar rats: part 1: dosimetry.

PubMed

Stepanenko, Valeriy; Rakhypbekov, Tolebay; Otani, Keiko; Endo, Satoru; Satoh, Kenichi; Kawano, Noriyuki; Shichijo, Kazuko; Nakashima, Masahiro; Takatsuji, Toshihiro; Sakaguchi, Aya; Kato, Hiroaki; Onda, Yuichi; Fujimoto, Nariaki; Toyoda, Shin; Sato, Hitoshi; Dyussupov, Altay; Chaizhunusova, Nailya; Sayakenov, Nurlan; Uzbekov, Darkhan; Saimova, Aisulu; Shabdarbaeva, Dariya; Skakov, Mazhin; Vurim, Alexandr; Gnyrya, Vyacheslav; Azimkhanov, Almas; Kolbayenkov, Alexander; Zhumadilov, Kasym; Kairikhanova, Yankar; Kaprin, Andrey; Galkin, Vsevolod; Ivanov, Sergey; Kolyzhenkov, Timofey; Petukhov, Aleksey; Yaskova, Elena; Belukha, Irina; Khailov, Artem; Skvortsov, Valeriy; Ivannikov, Alexander; Akhmedova, Umukusum; Bogacheva, Viktoria; Hoshi, Masaharu

2017-03-01

There were two sources of ionizing irradiation after the atomic bombings of Hiroshima and Nagasaki: (1) initial gamma-neutron irradiation at the moment of detonation and (2) residual radioactivity. Residual radioactivity consisted of two components: radioactive fallout containing fission products, including radioactive fissile materials from nuclear device, and neutron-activated radioisotopes from materials on the ground. The dosimetry systems DS86 and DS02 were mainly devoted to the assessment of initial radiation exposure to neutrons and gamma rays, while only brief considerations were given for the estimation of doses caused by residual radiation exposure. Currently, estimation of internal exposure of atomic bomb survivors due to dispersed radioactivity and neutron-activated radioisotopes from materials on the ground is a matter of some interest, in Japan. The main neutron-activated radionuclides in soil dust were 24 Na, 28 Al, 31 Si, 32 P, 38 Cl, 42 K, 45 Ca, 46 Sc, 56 Mn, 59 Fe, 60 Co, and 134 Cs. The radionuclide 56 Mn (T 1/2 = 2.58 h) is known as one of the dominant beta- and gamma emitters during the first few hours after neutron irradiation of soil and other materials on ground, dispersed in the form of dust after a nuclear explosion in the atmosphere. To investigate the peculiarities of biological effects of internal exposure to 56 Mn in comparison with external gamma irradiation, a dedicated experiment with Wistar rats exposed to neutron-activated 56 Mn dioxide powder was performed recently by Shichijo and coworkers. The dosimetry required for this experiment is described here. Assessment of internal radiation doses was performed on the basis of measured 56 Mn activity in the organs and tissues of the rats and of absorbed fractions of internal exposure to photons and electrons calculated with the MCNP-4C Monte Carlo using a mathematical rat phantom. The first results of this international multicenter study show that the internal irradiation due to incorporated 56 Mn powder is highly inhomogeneous, and that the most irradiated organs of the experimental animals are: large intestine, small intestine, stomach, and lungs. Accumulated absorbed organ doses were 1.65, 1.33, 0.24, 0.10 Gy for large intestine, small intestine, stomach, and lungs, respectively. Other organs were irradiated at lower dose levels. These results will be useful for interpretation of the biological effects of internal exposure of experimental rats to powdered 56 Mn as observed by Shichijo and coworkers.

The Production, Value, and Reduction Responsibility of Carbon Emissions through Electricity Consumption of Manufacturing Industries in South Korea and Thailand

NASA Astrophysics Data System (ADS)

Kitikun, Medhawin

This dissertation provides a new method of measuring efforts by manufacturing industries to reduce their emissions by curtailing electricity consumption. Employing comprehensive firm-level data from the National Manufacture Annual Surveys of South Korea and Thailand, I construct the measure from estimates of revenue functions by industry. The data consists of firms from more than 20 industries in each year from 1982 to 2005 for Korea and from 2001 to 2008 for Thailand. With a total of more than two million observations, I estimate revenue functions for each industry and year. Here, I use three inputs: number of employees(L), fixed asset stock(K), and electricity consumption(E) and two types of functional forms to represent each industry's revenue function. Second, under market competitive condition, I find that profit maximizing firms deviated their level of electricity usage in production from the profit-maximizing level during the time period for both countries, and I develop a theoretical framework to explain this behavior. Then, I tested the theory using my empirical models. Results support the notion of a hidden environmental value expressed by firms in the form of voluntary deviations from profit-maximizing levels of input demand. The measure used is the gap between the marginal revenue product of electricity and its price. This gap should increase with income, consistent with the Environmental Kuznets Curve literature. My current model provides considerable support for this proposition. Estimates indicate, in most industries, a negative relationship between per-capita income and emissions. In the final section of the dissertation, I consider the equitable distribution of emissions reduction burden under an international agreement such as the reduction effort, Kyoto Protocol. Both developed and developing countries have to cut their emissions to a specific reduction percentage target. Domestically, I present two extreme scenarios. In the first scenario, manufacturing industries take full responsibility for emissions reductions by curtailing their use of energy without any subsidies from the government. Revenue function estimates provide measures of the differential costs imposed on different industries by emissions reductions. In the second scenario, emissions reductions are achieved by changing the mix of electricity generation technologies used by the power generation sector within the country. For the international case, I focus on the fairness of emission reduction responsibility among countries. To be fair to countries at different levels of development and with different rate of carbon emissions, I propose a new method to adjust the timing and rates of emission reductions based on a lifetime cumulative emission per capita.

Accuracy and reliability testing of two methods to measure internal rotation of the glenohumeral joint.

PubMed

Hall, Justin M; Azar, Frederick M; Miller, Robert H; Smith, Richard; Throckmorton, Thomas W

2014-09-01

We compared accuracy and reliability of a traditional method of measurement (most cephalad vertebral spinous process that can be reached by a patient with the extended thumb) to estimates made with the shoulder in abduction to determine if there were differences between the two methods. Six physicians with fellowship training in sports medicine or shoulder surgery estimated measurements in 48 healthy volunteers. Three were randomly chosen to make estimates of both internal rotation measurements for each volunteer. An independent observer made objective measurements on lateral scoliosis films (spinous process method) or with a goniometer (abduction method). Examiners were blinded to objective measurements as well as to previous estimates. Intraclass coefficients for interobserver reliability for the traditional method averaged 0.75, indicating good agreement among observers. The difference in vertebral level estimated by the examiner and the actual radiographic level averaged 1.8 levels. The intraclass coefficient for interobserver reliability for the abduction method averaged 0.81 for all examiners, indicating near-perfect agreement. Confidence intervals indicated that estimates were an average of 8° different from the objective goniometer measurements. Pearson correlation coefficients of intraobserver reliability for the abduction method averaged 0.94, indicating near-perfect agreement within observers. Confidence intervals demonstrated repeated estimates between 5° and 10° of the original. Internal rotation estimates made with the shoulder abducted demonstrated interobserver reliability superior to that of spinous process estimates, and reproducibility was high. On the basis of this finding, we now take glenohumeral internal rotation measurements with the shoulder in abduction and use a goniometer to maximize accuracy and objectivity. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Causal inference with measurement error in outcomes: Bias analysis and estimation methods.

PubMed

Shu, Di; Yi, Grace Y

2017-01-01

Inverse probability weighting estimation has been popularly used to consistently estimate the average treatment effect. Its validity, however, is challenged by the presence of error-prone variables. In this paper, we explore the inverse probability weighting estimation with mismeasured outcome variables. We study the impact of measurement error for both continuous and discrete outcome variables and reveal interesting consequences of the naive analysis which ignores measurement error. When a continuous outcome variable is mismeasured under an additive measurement error model, the naive analysis may still yield a consistent estimator; when the outcome is binary, we derive the asymptotic bias in a closed-form. Furthermore, we develop consistent estimation procedures for practical scenarios where either validation data or replicates are available. With validation data, we propose an efficient method for estimation of average treatment effect; the efficiency gain is substantial relative to usual methods of using validation data. To provide protection against model misspecification, we further propose a doubly robust estimator which is consistent even when either the treatment model or the outcome model is misspecified. Simulation studies are reported to assess the performance of the proposed methods. An application to a smoking cessation dataset is presented.

Consistent estimate of ocean warming, land ice melt and sea level rise from Observations

NASA Astrophysics Data System (ADS)

Blazquez, Alejandro; Meyssignac, Benoît; Lemoine, Jean Michel

2016-04-01

Based on the sea level budget closure approach, this study investigates the consistency of observed Global Mean Sea Level (GMSL) estimates from satellite altimetry, observed Ocean Thermal Expansion (OTE) estimates from in-situ hydrographic data (based on Argo for depth above 2000m and oceanic cruises below) and GRACE observations of land water storage and land ice melt for the period January 2004 to December 2014. The consistency between these datasets is a key issue if we want to constrain missing contributions to sea level rise such as the deep ocean contribution. Numerous previous studies have addressed this question by summing up the different contributions to sea level rise and comparing it to satellite altimetry observations (see for example Llovel et al. 2015, Dieng et al. 2015). Here we propose a novel approach which consists in correcting GRACE solutions over the ocean (essentially corrections of stripes and leakage from ice caps) with mass observations deduced from the difference between satellite altimetry GMSL and in-situ hydrographic data OTE estimates. We check that the resulting GRACE corrected solutions are consistent with original GRACE estimates of the geoid spherical harmonic coefficients within error bars and we compare the resulting GRACE estimates of land water storage and land ice melt with independent results from the literature. This method provides a new mass redistribution from GRACE consistent with observations from Altimetry and OTE. We test the sensibility of this method to the deep ocean contribution and the GIA models and propose best estimates.

The reliability of the Hendrich Fall Risk Model in a geriatric hospital.

PubMed

Heinze, Cornelia; Halfens, Ruud; Dassen, Theo

2008-12-01

Aims and objectives.  The purpose of this study was to test the interrater reliability of the Hendrich Fall Risk Model, an instrument to identify patients in a hospital setting with a high risk of falling. Background.  Falls are a serious problem in older patients. Valid and reliable fall risk assessment tools are required to identify high-risk patients and to take adequate preventive measures. Methods.  Seventy older patients were independently and simultaneously assessed by six pairs of raters made up of nursing staff members. Consensus estimates were calculated using simple percentage agreement and consistency estimates using Spearman's rho and intra class coefficient. Results.  Percentage agreement ranged from 0.70 to 0.92 between the six pairs of raters. Spearman's rho coefficients were between 0.54 and 0.80 and the intra class coefficients were between 0.46 and 0.92. Conclusions.  Whereas some pairs of raters obtained considerable interobserver agreement and internal consistency, the others did not. Therefore, it is concluded that the Hendrich Fall Risk Model is not a reliable instrument. The use of more unambiguous operationalized items is preferred. Relevance to clinical practice.  In practice, well operationalized fall risk assessment tools are necessary. Observer agreement should always be investigated after introducing a standardized measurement tool. © 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd.

Multi-model approach to petroleum resource appraisal using analytic methodologies for probabilistic systems

USGS Publications Warehouse

Crovelli, R.A.

1988-01-01

The geologic appraisal model that is selected for a petroleum resource assessment depends upon purpose of the assessment, basic geologic assumptions of the area, type of available data, time available before deadlines, available human and financial resources, available computer facilities, and, most importantly, the available quantitative methodology with corresponding computer software and any new quantitative methodology that would have to be developed. Therefore, different resource assessment projects usually require different geologic models. Also, more than one geologic model might be needed in a single project for assessing different regions of the study or for cross-checking resource estimates of the area. Some geologic analyses used in the past for petroleum resource appraisal involved play analysis. The corresponding quantitative methodologies of these analyses usually consisted of Monte Carlo simulation techniques. A probabilistic system of petroleum resource appraisal for play analysis has been designed to meet the following requirements: (1) includes a variety of geologic models, (2) uses an analytic methodology instead of Monte Carlo simulation, (3) possesses the capacity to aggregate estimates from many areas that have been assessed by different geologic models, and (4) runs quickly on a microcomputer. Geologic models consist of four basic types: reservoir engineering, volumetric yield, field size, and direct assessment. Several case histories and present studies by the U.S. Geological Survey are discussed. ?? 1988 International Association for Mathematical Geology.

Two-Component Structure of the Radio Source 0014+813 from VLBI Observations within the CONT14 Program

NASA Astrophysics Data System (ADS)

Titov, O. A.; Lopez, Yu. R.

2018-03-01

We consider a method of reconstructing the structure delay of extended radio sources without constructing their radio images. The residuals derived after the adjustment of geodetic VLBI observations are used for this purpose. We show that the simplest model of a radio source consisting of two point components can be represented by four parameters (the angular separation of the components, the mutual orientation relative to the poleward direction, the flux-density ratio, and the spectral index difference) that are determined for each baseline of a multi-baseline VLBI network. The efficiency of this approach is demonstrated by estimating the coordinates of the radio source 0014+813 observed during the two-week CONT14 program organized by the International VLBI Service (IVS) in May 2014. Large systematic deviations have been detected in the residuals of the observations for the radio source 0014+813. The averaged characteristics of the radio structure of 0014+813 at a frequency of 8.4 GHz can be calculated from these deviations. Our modeling using four parameters has confirmed that the source consists of two components at an angular separation of 0.5 mas in the north-south direction. Using the structure delay when adjusting the CONT14 observations leads to a correction of the average declination estimate for the radio source 0014+813 by 0.070 mas.

The Relationships Between Internal and External Measures of Training Load and Intensity in Team Sports: A Meta-Analysis.

PubMed

McLaren, Shaun J; Macpherson, Tom W; Coutts, Aaron J; Hurst, Christopher; Spears, Iain R; Weston, Matthew

2018-03-01

The associations between internal and external measures of training load and intensity are important in understanding the training process and the validity of specific internal measures. We aimed to provide meta-analytic estimates of the relationships, as determined by a correlation coefficient, between internal and external measures of load and intensity during team-sport training and competition. A further aim was to examine the moderating effects of training mode on these relationships. We searched six electronic databases (Scopus, Web of Science, PubMed, MEDLINE, SPORTDiscus, CINAHL) for original research articles published up to September 2017. A Boolean search phrase was created to include search terms relevant to team-sport athletes (population; 37 keywords), internal load (dependent variable; 35 keywords), and external load (independent variable; 81 keywords). Articles were considered for meta-analysis when a correlation coefficient describing the association between at least one internal and one external measure of session load or intensity, measured in the time or frequency domain, was obtained from team-sport athletes during normal training or match-play (i.e., unstructured observational study). The final data sample included 122 estimates from 13 independent studies describing 15 unique relationships between three internal and nine external measures of load and intensity. This sample included 295 athletes and 10,418 individual session observations. Internal measures were session ratings of perceived exertion (sRPE), sRPE training load (sRPE-TL), and heart-rate-derived training impulse (TRIMP). External measures were total distance (TD), the distance covered at high and very high speeds (HSRD ≥ 13.1-15.0 km h -1 and VHSRD ≥ 16.9-19.8 km h -1 , respectively), accelerometer load (AL), and the number of sustained impacts (Impacts > 2-5 G). Distinct training modes were identified as either mixed (reference condition), skills, metabolic, or neuromuscular. Separate random effects meta-analyses were conducted for each dataset (n = 15) to determine the pooled relationships between internal and external measures of load and intensity. The moderating effects of training mode were examined using random-effects meta-regression for datasets with at least ten estimates (n = 4). Magnitude-based inferences were used to interpret analyses outcomes. During all training modes combined, the external load relationships for sRPE-TL were possibly very large with TD [r = 0.79; 90% confidence interval (CI) 0.74 to 0.83], possibly large with AL (r = 0.63; 90% CI 0.54 to 0.70) and Impacts (r = 0.57; 90% CI 0.47 to 0.64), and likely moderate with HSRD (r = 0.47; 90% CI 0.32 to 0.59). The relationship between TRIMP and AL was possibly large (r = 0.54; 90% CI 0.40 to 0.66). All other relationships were unclear or not possible to infer (r range 0.17-0.74, n = 10 datasets). Between-estimate heterogeneity [standard deviations (SDs) representing unexplained variation; τ] in the pooled internal-external relationships were trivial to extremely large for sRPE (τ range = 0.00-0.47), small to large for sRPE-TL (τ range = 0.07-0.31), and trivial to moderate for TRIMP (τ range= 0.00-0.17). The internal-external load relationships during mixed training were possibly very large for sRPE-TL with TD (r = 0.82; 90% CI 0.75 to 0.87) and AL (r = 0.81; 90% CI 0.74 to 0.86), and TRIMP with AL (r = 0.72; 90% CI 0.55 to 0.84), and possibly large for sRPE-TL with HSRD (r = 0.65; 90% CI 0.44 to 0.80). A reduction in these correlation magnitudes was evident for all other training modes (range of the change in r when compared with mixed training - 0.08 to - 0.58), with these differences being unclear to possibly large. Training mode explained 24-100% of the between-estimate variance in the internal-external load relationships. Measures of internal load derived from perceived exertion and heart rate show consistently positive associations with running- and accelerometer-derived external loads and intensity during team-sport training and competition, but the magnitude and uncertainty of these relationships are measure and training mode dependent.

[Factor analysis and internal consistency of pedagogical practices questionnaire among health care teachers].

PubMed

Pérez V, Cristhian; Vaccarezza G, Giulietta; Aguilar A, César; Coloma N, Katherine; Salgado F, Horacio; Baquedano R, Marjorie; Chavarría R, Carla; Bastías V, Nancy

2016-06-01

Teaching practice is one of the most complex topics of the training process in medicine and other health care careers. The Teaching Practices Questionnaire (TPQ) evaluates teaching skills. To assess the factor structure and internal consistency of the Spanish version of the TPP among health care teachers. The TPQ was answered by 315 university teachers from 13 of the 15 administrative Chilean regions, who were selected through a non-probabilistic volunteer sampling. The internal consistency of TPP factors was calculated and the correlation between them was analyzed. Six factors were identified: Student-centered teaching, Teaching planning, Assessment process, Dialogue relationship, Teacher-centered teaching and Use of technological resources. They had Cronbach alphas ranging from 0.60 to 0.85. The factorial structure of TPQ differentiates the most important functions of teaching. It also shows a theoretical consistency and a practical relevance to perform a diagnosis and continuous evaluation of teaching practices. Additionally, it has an adequate internal consistency. Thus, TPQ is valid and reliable to evaluate pedagogical practices in health care careers.

Online self-report questionnaire on computer work-related exposure (OSCWE): validity and internal consistency.

PubMed

Mekhora, Keerin; Jalayondeja, Wattana; Jalayondeja, Chutima; Bhuanantanondh, Petcharatana; Dusadiisariyavong, Asadang; Upiriyasakul, Rujiret; Anuraktam, Khajornyod

2014-07-01

To develop an online, self-report questionnaire on computer work-related exposure (OSCWE) and to determine the internal consistency, face and content validity of the questionnaire. The online, self-report questionnaire was developed to determine the risk factors related to musculoskeletal disorders in computer users. It comprised five domains: personal, work-related, work environment, physical health and psychosocial factors. The questionnaire's content was validated by an occupational medical doctor and three physical therapy lecturers involved in ergonomic teaching. Twenty-five lay people examined the feasibility of computer-administered and the user-friendly language. The item correlation in each domain was analyzed by the internal consistency (Cronbach's alpha; alpha). The content of the questionnaire was considered congruent with the testing purposes. Eight hundred and thirty-five computer users at the PTT Exploration and Production Public Company Limited registered to the online self-report questionnaire. The internal consistency of the five domains was: personal (alpha = 0.58), work-related (alpha = 0.348), work environment (alpha = 0.72), physical health (alpha = 0.68) and psychosocial factor (alpha = 0.93). The findings suggested that the OSCWE had acceptable internal consistency for work environment and psychosocial factors. The OSCWE is available to use in population-based survey research among computer office workers.

Hierarchy of evidence: differences in results between non-randomized studies and randomized trials in patients with femoral neck fractures.

PubMed

Bhandari, Mohit; Tornetta, Paul; Ellis, Thomas; Audige, Laurent; Sprague, Sheila; Kuo, Jonathann C; Swiontkowski, Marc F

2004-01-01

There have been a number of non-randomized studies comparing arthroplasty with internal fixation in patients with femoral neck fractures. However, there remains considerable debate about whether the results of non-randomized studies are consistent with the results of randomized, controlled trials. Given the economic burden of hip fractures, it remains essential to identify therapies to improve outcomes; however, whether data from non-randomized studies of an intervention should be used to guide patient care remains unclear. We aimed to determine whether the pooled results of mortality and revision surgery among non-randomized studies were similar to those of randomized trials in studies comparing arthroplasty with internal fixation in patients with femoral neck fractures. We conducted a Medline search from 1969 to June 2002, identifying both randomized and non-randomized studies comparing internal fixation with arthroplasty in patients with femoral neck fractures. Additional strategies to identify relevant articles included Cochrane database, SCISEARCH, textbooks, annual meeting programs, and content experts. We abstracted information on mortality and revision rates in each study and compared the pooled results between non-randomized and randomized studies. In addition, we explored potential reasons for dissimilar results between the two study designs. We identified 140 citations that addressed the general topic of comparison of arthroplasty and internal fixation for hip fracture. Of these, 27 studies met the eligibility criteria, 13 of which were non-randomized studies and 14 of which were randomized trials. Mortality data was available in all 13 non-randomized studies ( n=3108 patients) and in 12 randomized studies ( n=1767 patients). Non-randomized studies overestimated the risk of mortality by 40% when compared with the results of randomized trials (relative risk 1.44 vs 1.04, respectively). Information on revision risk was available in 9 non-randomized studies ( n=2764 patients) and all 14 randomized studies ( n=1901 patients). Both estimates from non-randomized and randomized studies revealed a significant reduction in the risk of revision surgery with arthroplasty compared with internal fixation (relative risk 0.38 vs 0.23, respectively). The reduction in the risk of revision surgery with arthroplasty compared with internal fixation was 62% for non-randomized studies and 77% for randomized trials. Thus, non-randomized studies underestimated the relative benefit of arthroplasty by 19.5%. Non-randomized studies with point estimates of relative risk similar to the pooled estimate for randomized trials all controlled for patient age, gender, and fracture displacement in their comparisons of mortality. We were unable to identify reasons for differences in the revision rate results between the study designs. Similar to other reports in medical subspecialties, non-randomized studies provided results dissimilar to randomized trials of arthroplasty vs internal fixation for mortality and revision rates in patients with femoral neck fractures. Investigators should be aware of these discrepancies when evaluating the merits of alternative surgical interventions, especially when both randomized trials and non-randomized comparative studies are available.

Schooling, Literacy and Individual Earnings. International Adult Literacy Survey.

ERIC Educational Resources Information Center

Osberg, Lars

This paper uses direct measures of literacy skill levels provided by the International Adult Literacy Survey to estimate the return to literacy skills. Using a very simple human capital earnings equation and standard ordinary least squares regression, it tested estimates of the return to literacy skills for their robustness to alternative scalings…

12 CFR 324.132 - Counterparty credit risk of repo-style transactions, eligible margin loans, and OTC derivative...

Code of Federal Regulations, 2014 CFR

2014-01-01

... of significant financial stress appropriate to the security or category of securities. (5) An FDIC... significant financial stress used to calculate the FDIC-supervised institution's own internal estimates for... significant financial stress in the calculation of own internal estimates for haircuts. (7) An FDIC-supervised...

ESTIMATION OF EARLY INTERNAL DOSES TO FUKUSHIMA RESIDENTS AFTER THE NUCLEAR DISASTER BASED ON THE ATMOSPHERIC DISPERSION SIMULATION.

PubMed

Kim, Eunjoo; Tani, Kotaro; Kunishima, Naoaki; Kurihara, Osamu; Sakai, Kazuo; Akashi, Makoto

2016-11-01

Estimating the early internal doses to residents in the Fukushima Daiichi Nuclear Power Station accident is a difficult task because limited human/environmental measurement data are available. Hence, the feasibility of using atmospheric dispersion simulations created by the Worldwide version of System for Prediction of Environmental Emergency Dose Information 2nd Version (WSPEEDI-II) in the estimation was examined in the present study. This examination was done by comparing the internal doses evaluated based on the human measurements with those calculated using time series air concentration maps ( 131 I and 137 Cs) generated by WSPEEDI-II. The results showed that the latter doses were several times higher than the former doses. However, this discrepancy could be minimised by taking into account personal behaviour data that will be available soon. This article also presents the development of a prototype system for estimating the internal dose based on the simulations. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A framework and a measurement instrument for sustainability of work practices in long-term care

PubMed Central

2011-01-01

Background In health care, many organizations are working on quality improvement and/or innovation of their care practices. Although the effectiveness of improvement processes has been studied extensively, little attention has been given to sustainability of the changed work practices after implementation. The objective of this study is to develop a theoretical framework and measurement instrument for sustainability. To this end sustainability is conceptualized with two dimensions: routinization and institutionalization. Methods The exploratory methodological design consisted of three phases: a) framework development; b) instrument development; and c) field testing in former improvement teams in a quality improvement program for health care (N teams = 63, N individual = 112). Data were collected not until at least one year had passed after implementation. Underlying constructs and their interrelations were explored using Structural Equation Modeling and Principal Component Analyses. Internal consistency was computed with Cronbach's alpha coefficient. A long and a short version of the instrument are proposed. Results The χ2- difference test of the -2 Log Likelihood estimates demonstrated that the hierarchical two factor model with routinization and institutionalization as separate constructs showed a better fit than the one factor model (p < .01). Secondly, construct validity of the instrument was strong as indicated by the high factor loadings of the items. Finally, the internal consistency of the subscales was good. Conclusions The theoretical framework offers a valuable starting point for the analysis of sustainability on the level of actual changed work practices. Even though the two dimensions routinization and institutionalization are related, they are clearly distinguishable and each has distinct value in the discussion of sustainability. Finally, the subscales conformed to psychometric properties defined in literature. The instrument can be used in the evaluation of improvement projects. PMID:22087884

Development and psychometric evaluation of the Primary Health Care Engagement (PHCE) Scale: a pilot survey of rural and remote nurses.

PubMed

Kosteniuk, Julie G; Wilson, Erin C; Penz, Kelly L; MacLeod, Martha L P; Stewart, Norma J; Kulig, Judith C; Karunanayake, Chandima P; Kilpatrick, Kelley

2016-01-01

To report the development and psychometric evaluation of a scale to measure rural and remote (rural/remote) nurses' perceptions of the engagement of their workplaces in key dimensions of primary health care (PHC). Amidst ongoing PHC reforms, a comprehensive instrument is needed to evaluate the degree to which rural/remote health care settings are involved in the key dimensions that characterize PHC delivery, particularly from the perspective of professionals delivering care. This study followed a three-phase process of instrument development and psychometric evaluation. A literature review and expert consultation informed instrument development in the first phase, followed by an iterative process of content evaluation in the second phase. In the final phase, a pilot survey was undertaken and item discrimination analysis employed to evaluate the internal consistency reliability of each subscale in the preliminary 60-item Primary Health Care Engagement (PHCE) Scale. The 60-item scale was subsequently refined to a 40-item instrument. The pilot survey sample included 89 nurses in current practice who had experience in rural/remote practice settings. Participants completed either a web-based or paper survey from September to December, 2013. Following item discrimination analysis, the 60-item instrument was refined to a 40-item PHCE Scale consisting of 10 subscales, each including three to five items. Alpha estimates of the 10 refined subscales ranged from 0.61 to 0.83, with seven of the subscales demonstrating acceptable reliability (α ⩾ 0.70). The refined 40-item instrument exhibited good internal consistency reliability (α=0.91). The 40-item PHCE Scale may be considered for use in future studies regardless of locale, to measure the extent to which health care professionals perceive their workplaces to be engaged in key dimensions of PHC.

Currents and Mixing in the San Lorenzo Overflow, Northern Gulf of California

NASA Astrophysics Data System (ADS)

Rosas-Villegas, Froylán.; López, Manuel; Candela, Julio

2018-02-01

The main properties of the San Lorenzo (SL) overflow are studied, using data from two nonsimultaneous ADCP moorings (located at the sill, and 5 km downstream), as well as CTD and LADCP profiles. Strong tidal currents at the sill modulate the overflow, which is not shut down during the neaps. At the downstream site, the largest flood currents are associated with colder water advected from the sill, flowing downslope, and creating an asymmetry in the semidiurnal tidal cycle. The overflow introduces a significant fortnightly harmonic at the downstream site, and delays the M2 tidal currents for more than an hour with respect to the currents at the sill. The overflow mixes with the overlying water by entrainment during its supercritical stage, reaching near-bottom velocities as high as 1.5 ms-1 and an estimated mean transport of 0.11 Sv; almost twice that estimated at the sill for the same period of the year. Estimated Froude numbers during spring tides suggest the development of an internal hydraulic jump. After relaxation of the maximum downstream currents, high-frequency temperature fluctuations, likely linked to upstream traveling waves, are consistently observed. Direct estimations of the turbulent dissipation rates were used to compute diapycnal diffusivity (Kρ) profiles. Mean estimates of Kρ, as high as 5.5 × 10-2 m2s-1, show that shear at the interface is the most significant source of cross-isopycnal mixing along the SL overflow during ebb tides.