External validation of the NOBLADS score, a risk scoring system for severe acute lower gastrointestinal bleeding.

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Tomonori Aoki

Full Text Available We aimed to evaluate the generalizability of NOBLADS, a severe lower gastrointestinal bleeding (LGIB prediction model which we had previously derived when working at a different institution, using an external validation cohort. NOBLADS comprises the following factors: non-steroidal anti-inflammatory drug use, no diarrhea, no abdominal tenderness, blood pressure ≤ 100 mmHg, antiplatelet drug use, albumin < 3.0 g/dL, disease score ≥ 2, and syncope.We retrospectively analyzed 511 patients emergently hospitalized for acute LGIB at the University of Tokyo Hospital, from January 2009 to August 2016. The areas under the receiver operating characteristic curves (ROCs-AUCs for severe bleeding (continuous and/or recurrent bleeding were compared between the original derivation cohort and the external validation cohort.Severe LGIB occurred in 44% of patients. Several clinical factors were significantly different between the external and derivation cohorts (p < 0.05, including background, laboratory data, NOBLADS scores, and diagnosis. The NOBLADS score predicted the severity of LGIB with an AUC value of 0.74 in the external validation cohort and one of 0.77 in the derivation cohort. In the external validation cohort, the score predicted the risk for blood transfusion need (AUC, 0.71, but was not adequate for predicting intervention need (AUC, 0.54. The in-hospital mortality rate was higher in patients with a score ≥ 5 than in those with a score < 5 (AUC, 0.83.Although the external validation cohort clinically differed from the derivation cohort in many ways, we confirmed the moderately high generalizability of NOBLADS, a clinical risk score for severe LGIB. Appropriate triage using this score may support early decision-making in various hospitals.

External Validity in the Study of Human Development: Theoretical and Methodological Issues

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Hultsch, David F.; Hickey, Tom

1978-01-01

An examination of the concept of external validity from two theoretical perspectives: a traditional mechanistic approach and a dialectical organismic approach. Examines the theoretical and methodological implications of these perspectives. (BD)

The use of Geographic Information System (GIS) and non-GIS methods to assess the external validity of samples postcollection.

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Richardson, Esther; Good, Margaret; McGrath, Guy; More, Simon J

2009-09-01

External validity is fundamental to veterinary diagnostic investigation, reflecting the accuracy with which sample results can be extrapolated to a broader population of interest. Probability sampling methods are routinely used during the collection of samples from populations, specifically to maximize external validity. Nonprobability sampling (e.g., of blood samples collected as part of routine surveillance programs or laboratory submissions) may provide useful data for further posthoc epidemiological analysis, adding value to the collection and submission of samples. As the sample has already been submitted, the analyst or investigator does not have any control over the sampling methodology, and hence external validity as routine probability sampling methods may not have been employed. The current study describes several Geographic Information System (GIS) and non-GIS methods, applied posthoc, to assess the external validity of samples collected using both probability and nonprobability sampling methods. These methods could equally be employed for inspecting other datasets. Mapping was conducted using ArcView 9.1. Based on this posthoc assessment, results from the random field sample could provide an externally valid, albeit relatively imprecise, estimate of national disease prevalence, of disease prevalence in 3 of the 4 provinces (all but Ulster, in the north and northwest, where sample size was small), and in beef and dairy herds. This study provides practical methods for examining the external validity of samples postcollection.

Prediction of prostate cancer in unscreened men: external validation of a risk calculator.

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van Vugt, Heidi A; Roobol, Monique J; Kranse, Ries; Määttänen, Liisa; Finne, Patrik; Hugosson, Jonas; Bangma, Chris H; Schröder, Fritz H; Steyerberg, Ewout W

2011-04-01

Prediction models need external validation to assess their value beyond the setting where the model was derived from. To assess the external validity of the European Randomized study of Screening for Prostate Cancer (ERSPC) risk calculator (www.prostatecancer-riskcalculator.com) for the probability of having a positive prostate biopsy (P(posb)). The ERSPC risk calculator was based on data of the initial screening round of the ERSPC section Rotterdam and validated in 1825 and 531 men biopsied at the initial screening round in the Finnish and Swedish sections of the ERSPC respectively. P(posb) was calculated using serum prostate specific antigen (PSA), outcome of digital rectal examination (DRE), transrectal ultrasound and ultrasound assessed prostate volume. The external validity was assessed for the presence of cancer at biopsy by calibration (agreement between observed and predicted outcomes), discrimination (separation of those with and without cancer), and decision curves (for clinical usefulness). Prostate cancer was detected in 469 men (26%) of the Finnish cohort and in 124 men (23%) of the Swedish cohort. Systematic miscalibration was present in both cohorts (mean predicted probability 34% versus 26% observed, and 29% versus 23% observed, both pscreened men, but overestimated the risk of a positive biopsy. Further research is necessary to assess the performance and applicability of the ERSPC risk calculator when a clinical setting is considered rather than a screening setting. Copyright © 2010 Elsevier Ltd. All rights reserved.

External validation of a clinical scoring system for the risk of gestational diabetes mellitus

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van Leeuwen, M.; Opmeer, B. C.; Zweers, E. J. K.; van Ballegooie, E.; ter Brugge, H. G.; de Valk, H. W.; Visser, G. H. A.; Mol, B. W. J.

Aim: A prediction rule for gestational diabetes mellitus (GDM) could be helpful in early detection and increased efficiency of screening. A prediction rule by means of a clinical scoring system is available, but has never been validated externally. The aim of this study was to validate the scoring

External validation of the ability of the DRAGON score to predict outcome after thrombolysis treatment

DEFF Research Database (Denmark)

Ovesen, Christian Aavang; Christensen, Anders; Nielsen, J K

2013-01-01

Easy-to-perform and valid assessment scales for the effect of thrombolysis are essential in hyperacute stroke settings. Because of this we performed an external validation of the DRAGON scale proposed by Strbian et al. in a Danish cohort. All patients treated with intravenous recombinant plasmino......Easy-to-perform and valid assessment scales for the effect of thrombolysis are essential in hyperacute stroke settings. Because of this we performed an external validation of the DRAGON scale proposed by Strbian et al. in a Danish cohort. All patients treated with intravenous recombinant...... and their modified Rankin Scale (mRS) was assessed after 3 months. Three hundred and three patients were included in the analysis. The DRAGON scale proved to have a good discriminative ability for predicting highly unfavourable outcome (mRS 5-6) (area under the curve-receiver operating characteristic [AUC-ROC]: 0...

Derivation and external validation of a case mix model for the standardized reporting of 30-day stroke mortality rates.

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Bray, Benjamin D; Campbell, James; Cloud, Geoffrey C; Hoffman, Alex; James, Martin; Tyrrell, Pippa J; Wolfe, Charles D A; Rudd, Anthony G

2014-11-01

Case mix adjustment is required to allow valid comparison of outcomes across care providers. However, there is a lack of externally validated models suitable for use in unselected stroke admissions. We therefore aimed to develop and externally validate prediction models to enable comparison of 30-day post-stroke mortality outcomes using routine clinical data. Models were derived (n=9000 patients) and internally validated (n=18 169 patients) using data from the Sentinel Stroke National Audit Program, the national register of acute stroke in England and Wales. External validation (n=1470 patients) was performed in the South London Stroke Register, a population-based longitudinal study. Models were fitted using general estimating equations. Discrimination and calibration were assessed using receiver operating characteristic curve analysis and correlation plots. Two final models were derived. Model A included age (<60, 60-69, 70-79, 80-89, and ≥90 years), National Institutes of Health Stroke Severity Score (NIHSS) on admission, presence of atrial fibrillation on admission, and stroke type (ischemic versus primary intracerebral hemorrhage). Model B was similar but included only the consciousness component of the NIHSS in place of the full NIHSS. Both models showed excellent discrimination and calibration in internal and external validation. The c-statistics in external validation were 0.87 (95% confidence interval, 0.84-0.89) and 0.86 (95% confidence interval, 0.83-0.89) for models A and B, respectively. We have derived and externally validated 2 models to predict mortality in unselected patients with acute stroke using commonly collected clinical variables. In settings where the ability to record the full NIHSS on admission is limited, the level of consciousness component of the NIHSS provides a good approximation of the full NIHSS for mortality prediction. © 2014 American Heart Association, Inc.

External validation of the Cairns Prediction Model (CPM) to predict conversion from laparoscopic to open cholecystectomy.

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Hu, Alan Shiun Yew; Donohue, Peter O'; Gunnarsson, Ronny K; de Costa, Alan

2018-03-14

Valid and user-friendly prediction models for conversion to open cholecystectomy allow for proper planning prior to surgery. The Cairns Prediction Model (CPM) has been in use clinically in the original study site for the past three years, but has not been tested at other sites. A retrospective, single-centred study collected ultrasonic measurements and clinical variables alongside with conversion status from consecutive patients who underwent laparoscopic cholecystectomy from 2013 to 2016 in The Townsville Hospital, North Queensland, Australia. An area under the curve (AUC) was calculated to externally validate of the CPM. Conversion was necessary in 43 (4.2%) out of 1035 patients. External validation showed an area under the curve of 0.87 (95% CI 0.82-0.93, p = 1.1 × 10 -14 ). In comparison with most previously published models, which have an AUC of approximately 0.80 or less, the CPM has the highest AUC of all published prediction models both for internal and external validation. Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.

Review and evaluation of performance measures for survival prediction models in external validation settings

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M. Shafiqur Rahman

2017-04-01

Full Text Available Abstract Background When developing a prediction model for survival data it is essential to validate its performance in external validation settings using appropriate performance measures. Although a number of such measures have been proposed, there is only limited guidance regarding their use in the context of model validation. This paper reviewed and evaluated a wide range of performance measures to provide some guidelines for their use in practice. Methods An extensive simulation study based on two clinical datasets was conducted to investigate the performance of the measures in external validation settings. Measures were selected from categories that assess the overall performance, discrimination and calibration of a survival prediction model. Some of these have been modified to allow their use with validation data, and a case study is provided to describe how these measures can be estimated in practice. The measures were evaluated with respect to their robustness to censoring and ease of interpretation. All measures are implemented, or are straightforward to implement, in statistical software. Results Most of the performance measures were reasonably robust to moderate levels of censoring. One exception was Harrell’s concordance measure which tended to increase as censoring increased. Conclusions We recommend that Uno’s concordance measure is used to quantify concordance when there are moderate levels of censoring. Alternatively, Gönen and Heller’s measure could be considered, especially if censoring is very high, but we suggest that the prediction model is re-calibrated first. We also recommend that Royston’s D is routinely reported to assess discrimination since it has an appealing interpretation. The calibration slope is useful for both internal and external validation settings and recommended to report routinely. Our recommendation would be to use any of the predictive accuracy measures and provide the corresponding predictive

The Internal, External, and Diagnostic Validity of Sluggish Cognitive Tempo: A Meta-Analysis and Critical Review

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Becker, Stephen P.; Leopold, Daniel R.; Burns, G. Leonard; Jarrett, Matthew A.; Langberg, Joshua M.; Marshall, Stephen A.; McBurnett, Keith; Waschbusch, Daniel A.; Willcutt, Erik G.

2015-01-01

Objective To conduct the first meta-analysis evaluating the internal and external validity of the sluggish cognitive tempo (SCT) construct as related to or distinct from attention-deficit/hyperactivity disorder (ADHD) and as associated with functional impairment and neuropsychological functioning. Method Electronic databases were searched through September 2015 for studies examining the factor structure and/or correlates of SCT in children or adults. The search procedures identified 73 papers. The core SCT behaviors included across studies, as well as factor loadings and reliability estimates, were reviewed to evaluate internal validity. Pooled correlation effect sizes using random effects models were used to evaluate SCT in relation to external validity domains (i.e., demographics, other psychopathologies, functional impairment, and neuropsychological functioning). Results Strong support was found for the internal validity of the SCT construct. Specifically, across factor analytic studies including over 19,000 individuals, 13 SCT items loaded consistently on an SCT factor as opposed to an ADHD factor. Findings also support the reliability (i.e., internal consistency, test-retest reliability, inter-rater reliability) of SCT. In terms of external validity, there is some indication that SCT may increase with age (r = 0.11) and be associated with lower socioeconomic status (r = 0.10). Modest (potentially negligible) support was found for SCT symptoms being higher in males than females in children (r = 0.05) but not adults. SCT is more strongly associated with ADHD inattention (r = 0.63 in children, r = 0.72 in adults) than with ADHD hyperactivity-impulsivity (r = 0.32 in children, r = 0.46 in adults), and it likewise appears that SCT is more strongly associated with internalizing symptoms than with externalizing symptoms. SCT is associated with significant global, social, and academic impairment (rs = 0.38–0.44). Effects for neuropsychological functioning are mixed

The relationship between external and internal validity of randomized controlled trials: A sample of hypertension trials from China.

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Zhang, Xin; Wu, Yuxia; Ren, Pengwei; Liu, Xueting; Kang, Deying

2015-10-30

To explore the relationship between the external validity and the internal validity of hypertension RCTs conducted in China. Comprehensive literature searches were performed in Medline, Embase, Cochrane Central Register of Controlled Trials (CCTR), CBMdisc (Chinese biomedical literature database), CNKI (China National Knowledge Infrastructure/China Academic Journals Full-text Database) and VIP (Chinese scientific journals database) as well as advanced search strategies were used to locate hypertension RCTs. The risk of bias in RCTs was assessed by a modified scale, Jadad scale respectively, and then studies with 3 or more grading scores were included for the purpose of evaluating of external validity. A data extract form including 4 domains and 25 items was used to explore relationship of the external validity and the internal validity. Statistic analyses were performed by using SPSS software, version 21.0 (SPSS, Chicago, IL). 226 hypertension RCTs were included for final analysis. RCTs conducted in university affiliated hospitals (P internal validity. Multi-center studies (median = 4.0, IQR = 2.0) were scored higher internal validity score than single-center studies (median = 3.0, IQR = 1.0) (P internal validity (P = 0.004). Multivariate regression indicated sample size, industry-funding, quality of life (QOL) taken as measure and the university affiliated hospital as trial setting had statistical significance (P external validity of RCTs do associate with the internal validity, that do not stand in an easy relationship to each other. Regarding the poor reporting, other possible links between two variables need to trace in the future methodological researches.

Adapting social neuroscience measures for schizophrenia clinical trials, part 3: fathoming external validity.

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Olbert, Charles M; Penn, David L; Kern, Robert S; Lee, Junghee; Horan, William P; Reise, Steven P; Ochsner, Kevin N; Marder, Stephen R; Green, Michael F

2013-11-01

It is unknown whether measures adapted from social neuroscience linked to specific neural systems will demonstrate relationships to external variables. Four paradigms adapted from social neuroscience were administered to 173 clinically stable outpatients with schizophrenia to determine their relationships to functionally meaningful variables and to investigate their incremental validity beyond standard measures of social and nonsocial cognition. The 4 paradigms included 2 that assess perception of nonverbal social and action cues (basic biological motion and emotion in biological motion) and 2 that involve higher level inferences about self and others' mental states (self-referential memory and empathic accuracy). Overall, social neuroscience paradigms showed significant relationships to functional capacity but weak relationships to community functioning; the paradigms also showed weak correlations to clinical symptoms. Evidence for incremental validity beyond standard measures of social and nonsocial cognition was mixed with additional predictive power shown for functional capacity but not community functioning. Of the newly adapted paradigms, the empathic accuracy task had the broadest external validity. These results underscore the difficulty of translating developments from neuroscience into clinically useful tasks with functional significance.

Clashing Validities in the Comparative Method? Balancing In-Depth Understanding and Generalizability in Small-N Policy Studies

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van der Heijden, J.

2013-01-01

The comparative method receives considerable attention in political science. To some a main advantage of the method is that it allows for both in-depth insights (internal validity), and generalizability beyond the cases studied (external validity). However, others consider internal and external

External Validation of the Acoustic Voice Quality Index Version 03.01 With Extended Representativity.

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Barsties, Ben; Maryn, Youri

2016-07-01

The Acoustic Voice Quality Index (AVQI) is an objective method to quantify the severity of overall voice quality in concatenated continuous speech and sustained phonation segments. Recently, AVQI was successfully modified to be more representative and ecologically valid because the internal consistency of AVQI was balanced out through equal proportion of the 2 speech types. The present investigation aims to explore its external validation in a large data set. An expert panel of 12 speech-language therapists rated the voice quality of 1058 concatenated voice samples varying from normophonia to severe dysphonia. The Spearman rank-order correlation coefficients (r) were used to measure concurrent validity. The AVQI's diagnostic accuracy was evaluated with several estimates of its receiver operating characteristics (ROC). Finally, 8 of the 12 experts were chosen because of reliability criteria. A strong correlation was identified between AVQI and auditoryperceptual rating (r = 0.815, P = .000). It indicated that 66.4% of the auditory-perceptual rating's variation was explained by AVQI. Additionally, the ROC results showed again the best diagnostic outcome at a threshold of AVQI = 2.43. This study highlights external validation and diagnostic precision of the AVQI version 03.01 as a robust and ecologically valid measurement to objectify voice quality. © The Author(s) 2016.

Can Findings from Randomized Controlled Trials of Social Skills Training in Autism Spectrum Disorder Be Generalized? The Neglected Dimension of External Validity

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Jonsson, Ulf; Olsson, Nora Choque; Bölte, Sven

2016-01-01

Systematic reviews have traditionally focused on internal validity, while external validity often has been overlooked. In this study, we systematically reviewed determinants of external validity in the accumulated randomized controlled trials of social skills group interventions for children and adolescents with autism spectrum disorder. We…

External Validation of the HERNIAscore: An Observational Study.

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Cherla, Deepa V; Moses, Maya L; Mueck, Krislynn M; Hannon, Craig; Ko, Tien C; Kao, Lillian S; Liang, Mike K

2017-09-01

The HERNIAscore is a ventral incisional hernia (VIH) risk assessment tool that uses only preoperative variables and predictable intraoperative variables. The aim of this study was to validate and modify, if needed, the HERNIAscore in an external dataset. This was a retrospective observational study of all patients undergoing resection for gastrointestinal malignancy from 2011 through 2015 at a safety-net hospital. The primary end point was clinical postoperative VIH. Patients were stratified into low-risk, medium-risk, and high-risk groups based on HERNIAscore. A revised HERNIAscore was calculated with the addition of earlier abdominal operation as a categorical variable. Cox regression of incisional hernia with stratification by risk class was performed. Incidence rates of clinical VIH formation within each risk class were also calculated. Two hundred and forty-seven patents were enrolled. On Cox regression, in addition to the 3 variables of the HERNIAscore (BMI, COPD, and incision length), earlier abdominal operation was also predictive of VIH. The revised HERNIAscore demonstrated improved predictive accuracy for clinical VIH. Although the original HERNIAscore effectively stratified the risk of an incisional radiographic VIH developing, the revised HERNIAscore provided a statistically significant stratification for both clinical and radiographic VIHs in this patient cohort. We have externally validated and improved the HERNIAscore. The revised HERNIAscore uses BMI, incision length, COPD, and earlier abdominal operation to predict risk of postoperative incisional hernia. Future research should assess methods to prevent incisional hernias in moderate-to-high risk patients. Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Development and validation of the ExPRESS instrument for primary health care providers' evaluation of external supervision.

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Schriver, Michael; Cubaka, Vincent Kalumire; Vedsted, Peter; Besigye, Innocent; Kallestrup, Per

2018-01-01

External supervision of primary health care facilities to monitor and improve services is common in low-income countries. Currently there are no tools to measure the quality of support in external supervision in these countries. To develop a provider-reported instrument to assess the support delivered through external supervision in Rwanda and other countries. "External supervision: Provider Evaluation of Supervisor Support" (ExPRESS) was developed in 18 steps, primarily in Rwanda. Content validity was optimised using systematic search for related instruments, interviews, translations, and relevance assessments by international supervision experts as well as local experts in Nigeria, Kenya, Uganda and Rwanda. Construct validity and reliability were examined in two separate field tests, the first using exploratory factor analysis and a test-retest design, the second for confirmatory factor analysis. We included 16 items in section A ('The most recent experience with an external supervisor'), and 13 items in section B ('The overall experience with external supervisors'). Item-content validity index was acceptable. In field test I, test-retest had acceptable kappa values and exploratory factor analysis suggested relevant factors in sections A and B used for model hypotheses. In field test II, models were tested by confirmatory factor analysis fitting a 4-factor model for section A, and a 3-factor model for section B. ExPRESS is a promising tool for evaluation of the quality of support of primary health care providers in external supervision of primary health care facilities in resource-constrained settings. ExPRESS may be used as specific feedback to external supervisors to help identify and address gaps in the supervision they provide. Further studies should determine optimal interpretation of scores and the number of respondents needed per supervisor to obtain precise results, as well as test the functionality of section B.

Evaluating health inequity interventions: applying a contextual (external) validity framework to programs funded by the Canadian Health Services Research Foundation.

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Phillips, Kaye; Müller-Clemm, Werner; Ysselstein, Margaretha; Sachs, Jonathan

2013-02-01

Including context in the measurement and evaluation of health in equity interventions is critical to understanding how events that occur in an intervention's environment might contribute to or impede its success. This study adapted and piloted a contextual validity assessment framework on a selection of health inequity-related programs funded by the Canadian Health Services Research Foundation (CHSRF) between 1998 and 2006. The two overarching objectives of this study were (1) to determine the relative amount and quality of attention given to conceptualizing, measuring and validating context within CHSRF funded research final reports related to health-inequity; and (2) to contribute evaluative evidence towards the incorporation of context into the assessment and measurement of health inequity interventions. The study found that of the 42/146 CHSRF programs and projects, judged to be related to health inequity 20 adequately reported on the conceptualization, measurement and validation of context. Amongst these health-inequity related project reports, greatest emphasis was placed on describing the socio-political and economical context over actually measuring and validating contextual evidence. Applying a contextual validity assessment framework was useful for distinguishing between the descriptive (conceptual) versus empirical (measurement and validation) inclusion of documented contextual evidence. Although contextual validity measurement frameworks needs further development, this study contributes insight into identifying funded research related to health inequities and preliminary criteria for assessing interventions targeted at specific populations and jurisdictions. This study also feeds a larger critical dialogue (albeit beyond the scope of this study) regarding the relevance and utility of using evaluative techniques for understanding how specific external conditions support or impede the successful implementation of health inequity interventions. Copyright �

Development and External Validation of a Prognostic Nomogram for Metastatic Uveal Melanoma

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Valpione, Sara; Moser, Justin C.; Parrozzani, Raffaele; Bazzi, Marco; Mansfield, Aaron S.; Mocellin, Simone; Pigozzo, Jacopo; Midena, Edoardo; Markovic, Svetomir N.; Aliberti, Camillo; Campana, Luca G.; Chiarion-Sileni, Vanna

2015-01-01

Background Approximately 50% of patients with uveal melanoma (UM) will develop metastatic disease, usually involving the liver. The outcome of metastatic UM (mUM) is generally poor and no standard therapy has been established. Additionally, clinicians lack a validated prognostic tool to evaluate these patients. The aim of this work was to develop a reliable prognostic nomogram for clinicians. Patients and Methods Two cohorts of mUM patients, from Veneto Oncology Institute (IOV) (N=152) and Mayo Clinic (MC) (N=102), were analyzed to develop and externally validate, a prognostic nomogram. Results The median survival of mUM was 17.2 months in the IOV cohort and 19.7 in the MC cohort. Percentage of liver involvement (HR 1.6), elevated levels of serum LDH (HR 1.6), and a WHO performance status=1 (HR 1.5) or 2–3 (HR 4.6) were associated with worse prognosis. Longer disease-free interval from diagnosis of UM to that of mUM conferred a survival advantage (HR 0.9). The nomogram had a concordance probability of 0.75 (SE .006) in the development dataset (IOV), and 0.80 (SE .009) in the external validation (MC). Nomogram predictions were well calibrated. Conclusions The nomogram, which includes percentage of liver involvement, LDH levels, WHO performance status and disease free-interval accurately predicts the prognosis of mUM and could be useful for decision-making and risk stratification for clinical trials. PMID:25780931

Development and external validation of a prognostic nomogram for metastatic uveal melanoma.

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Sara Valpione

Full Text Available Approximately 50% of patients with uveal melanoma (UM will develop metastatic disease, usually involving the liver. The outcome of metastatic UM (mUM is generally poor and no standard therapy has been established. Additionally, clinicians lack a validated prognostic tool to evaluate these patients. The aim of this work was to develop a reliable prognostic nomogram for clinicians.Two cohorts of mUM patients, from Veneto Oncology Institute (IOV (N=152 and Mayo Clinic (MC (N=102, were analyzed to develop and externally validate, a prognostic nomogram.The median survival of mUM was 17.2 months in the IOV cohort and 19.7 in the MC cohort. Percentage of liver involvement (HR 1.6, elevated levels of serum LDH (HR 1.6, and a WHO performance status=1 (HR 1.5 or 2-3 (HR 4.6 were associated with worse prognosis. Longer disease-free interval from diagnosis of UM to that of mUM conferred a survival advantage (HR 0.9. The nomogram had a concordance probability of 0.75 (SE .006 in the development dataset (IOV, and 0.80 (SE .009 in the external validation (MC. Nomogram predictions were well calibrated.The nomogram, which includes percentage of liver involvement, LDH levels, WHO performance status and disease free-interval accurately predicts the prognosis of mUM and could be useful for decision-making and risk stratification for clinical trials.

Analysis of internal and external validity criteria for a computerized visual search task: A pilot study.

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Richard's, María M; Introzzi, Isabel; Zamora, Eliana; Vernucci, Santiago

2017-01-01

Inhibition is one of the main executive functions, because of its fundamental role in cognitive and social development. Given the importance of reliable and computerized measurements to assessment inhibitory performance, this research intends to analyze the internal and external criteria of validity of a computerized conjunction search task, to evaluate the role of perceptual inhibition. A sample of 41 children (21 females and 20 males), aged between 6 and 11 years old (M = 8.49, SD = 1.47), intentionally selected from a private management school of Mar del Plata (Argentina), middle socio-economic level were assessed. The Conjunction Search Task from the TAC Battery, Coding and Symbol Search tasks from Wechsler Intelligence Scale for Children were used. Overall, results allow us to confirm that the perceptual inhibition task form TAC presents solid rates of internal and external validity that make a valid measurement instrument of this process.

External Validation Study of First Trimester Obstetric Prediction Models (Expect Study I): Research Protocol and Population Characteristics.

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Meertens, Linda Jacqueline Elisabeth; Scheepers, Hubertina Cj; De Vries, Raymond G; Dirksen, Carmen D; Korstjens, Irene; Mulder, Antonius Lm; Nieuwenhuijze, Marianne J; Nijhuis, Jan G; Spaanderman, Marc Ea; Smits, Luc Jm

2017-10-26

A number of first-trimester prediction models addressing important obstetric outcomes have been published. However, most models have not been externally validated. External validation is essential before implementing a prediction model in clinical practice. The objective of this paper is to describe the design of a study to externally validate existing first trimester obstetric prediction models, based upon maternal characteristics and standard measurements (eg, blood pressure), for the risk of pre-eclampsia (PE), gestational diabetes mellitus (GDM), spontaneous preterm birth (PTB), small-for-gestational-age (SGA) infants, and large-for-gestational-age (LGA) infants among Dutch pregnant women (Expect Study I). The results of a pilot study on the feasibility and acceptability of the recruitment process and the comprehensibility of the Pregnancy Questionnaire 1 are also reported. A multicenter prospective cohort study was performed in The Netherlands between July 1, 2013 and December 31, 2015. First trimester obstetric prediction models were systematically selected from the literature. Predictor variables were measured by the Web-based Pregnancy Questionnaire 1 and pregnancy outcomes were established using the Postpartum Questionnaire 1 and medical records. Information about maternal health-related quality of life, costs, and satisfaction with Dutch obstetric care was collected from a subsample of women. A pilot study was carried out before the official start of inclusion. External validity of the models will be evaluated by assessing discrimination and calibration. Based on the pilot study, minor improvements were made to the recruitment process and online Pregnancy Questionnaire 1. The validation cohort consists of 2614 women. Data analysis of the external validation study is in progress. This study will offer insight into the generalizability of existing, non-invasive first trimester prediction models for various obstetric outcomes in a Dutch obstetric population

External validation of prognostic models to predict risk of gestational diabetes mellitus in one Dutch cohort: prospective multicentre cohort study.

NARCIS (Netherlands)

Lamain-de Ruiter, M.; Kwee, A.; Naaktgeboren, C.A.; Groot, I. de; Evers, I.M.; Groenendaal, F.; Hering, Y.R.; Huisjes, A.J.M.; Kirpestein, C.; Monincx, W.M.; Siljee, J.E.; Zelfde, A. van't; Oirschot, C.M. van; Vankan-Buitelaar, S.A.; Vonk, M.A.A.W.; Wiegers, T.A.; Zwart, J.J.; Franx, A.; Moons, K.G.M.; Koster, M.P.H.

2016-01-01

Objective: To perform an external validation and direct comparison of published prognostic models for early prediction of the risk of gestational diabetes mellitus, including predictors applicable in the first trimester of pregnancy. Design: External validation of all published prognostic models in

Multiple Score Comparison: a network meta-analysis approach to comparison and external validation of prognostic scores

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Sarah R. Haile

2017-12-01

Full Text Available Abstract Background Prediction models and prognostic scores have been increasingly popular in both clinical practice and clinical research settings, for example to aid in risk-based decision making or control for confounding. In many medical fields, a large number of prognostic scores are available, but practitioners may find it difficult to choose between them due to lack of external validation as well as lack of comparisons between them. Methods Borrowing methodology from network meta-analysis, we describe an approach to Multiple Score Comparison meta-analysis (MSC which permits concurrent external validation and comparisons of prognostic scores using individual patient data (IPD arising from a large-scale international collaboration. We describe the challenges in adapting network meta-analysis to the MSC setting, for instance the need to explicitly include correlations between the scores on a cohort level, and how to deal with many multi-score studies. We propose first using IPD to make cohort-level aggregate discrimination or calibration scores, comparing all to a common comparator. Then, standard network meta-analysis techniques can be applied, taking care to consider correlation structures in cohorts with multiple scores. Transitivity, consistency and heterogeneity are also examined. Results We provide a clinical application, comparing prognostic scores for 3-year mortality in patients with chronic obstructive pulmonary disease using data from a large-scale collaborative initiative. We focus on the discriminative properties of the prognostic scores. Our results show clear differences in performance, with ADO and eBODE showing higher discrimination with respect to mortality than other considered scores. The assumptions of transitivity and local and global consistency were not violated. Heterogeneity was small. Conclusions We applied a network meta-analytic methodology to externally validate and concurrently compare the prognostic properties

Estimating mortality from external causes using data from retrospective surveys: A validation study in Niakhar (Senegal

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Gilles Pison

2018-03-01

Full Text Available Background: In low- and middle-income countries (LMICs, data on causes of death is often inaccurate or incomplete. In this paper, we test whether adding a few questions about injuries and accidents to mortality questionnaires used in representative household surveys would yield accurate estimates of the extent of mortality due to external causes (accidents, homicides, or suicides. Methods: We conduct a validation study in Niakhar (Senegal, during which we compare reported survey data to high-quality prospective records of deaths collected by a health and demographic surveillance system (HDSS. Results: Survey respondents more frequently list the deaths of their adult siblings who die of external causes than the deaths of those who die from other causes. The specificity of survey data is high, but sensitivity is low. Among reported deaths, less than 60Š of the deaths classified as due to external causes by the HDSS are also classified as such by survey respondents. Survey respondents better report deaths due to road-traffic accidents than deaths from suicides and homicides. Conclusions: Asking questions about deaths resulting from injuries and accidents during surveys might help measure mortality from external causes in LMICs, but the resulting data displays systematic bias in a rural population of Senegal. Future studies should 1 investigate whether similar biases also apply in other settings and 2 test new methods to further improve the accuracy of survey data on mortality from external causes. Contribution: This study helps strengthen the monitoring of sustainable development targets in LMICs by validating a simple approach for the measurement of mortality from external causes.

Students' Understanding of External Representations of the Potassium Ion Channel Protein Part II: Structure-Function Relationships and Fragmented Knowledge

Science.gov (United States)

Harle, Marissa; Towns, Marcy H.

2012-01-01

Research that has focused on external representations in biochemistry has uncovered student difficulties in comprehending and interpreting external representations. This study focuses on students' understanding of three external representations (ribbon diagram, wireframe, and hydrophobic/hydrophilic) of the potassium ion channel protein. Analysis…

External validation of a clinical prediction rule to predict full recovery and ongoing moderate/severe disability following acute whiplash injury.

Science.gov (United States)

Ritchie, Carrie; Hendrikz, Joan; Jull, Gwendolen; Elliott, James; Sterling, Michele

2015-04-01

Retrospective secondary analysis of data. To investigate the external validity of the whiplash clinical prediction rule (CPR). We recently derived a whiplash CPR to consolidate previously established prognostic factors for poor recovery from a whiplash injury and predicted 2 recovery pathways. Prognostic factors for full recovery were being less than 35 years of age and having an initial Neck Disability Index (NDI) score of 32% or less. Prognostic factors for ongoing moderate/severe pain and disability were being 35 years of age or older, having an initial NDI score of 40% or more, and the presence of hyperarousal symptoms. Validation is required to confirm the reproducibility and accuracy of this CPR. Clinician feedback on the usefulness of the CPR is also important to gauge acceptability. A secondary analysis of data from 101 individuals with acute whiplash-associated disorder who had previously participated in either a randomized controlled clinical trial or prospective cohort study was performed using accuracy statistics. Full recovery was defined as NDI score at 6 months of 10% or less, and ongoing moderate/severe pain and disability were defined as an NDI score at 6 months of 30% or greater. In addition, a small sample of physical therapists completed an anonymous survey on the clinical acceptability and usability of the tool. Results The positive predictive value of ongoing moderate/severe pain and disability was 90.9% in the validation cohort, and the positive predictive value of full recovery was 80.0%. Surveyed physical therapists reported that the whiplash CPR was simple, understandable, would be easy to use, and was an acceptable prognostic tool. External validation of the whiplash CPR confirmed the reproducibility and accuracy of this dual-pathway tool for individuals with acute whiplash-associated disorder. Further research is needed to assess prospective validation, the impact of inclusion on practice, and to examine the efficacy of linking treatment

3D Simulation of External Flooding Events for the RISMC Pathway

International Nuclear Information System (INIS)

Prescott, Steven; Mandelli, Diego; Sampath, Ramprasad; Smith, Curtis; Lin, Linyu

2015-01-01

Incorporating 3D simulations as part of the Risk-Informed Safety Margins Characterization (RISMIC) Toolkit allows analysts to obtain a more complete picture of complex system behavior for events including external plant hazards. External events such as flooding have become more important recently – however these can be analyzed with existing and validated simulated physics toolkits. In this report, we describe these approaches specific to flooding-based analysis using an approach called Smoothed Particle Hydrodynamics. The theory, validation, and example applications of the 3D flooding simulation are described. Integrating these 3D simulation methods into computational risk analysis provides a spatial/visual aspect to the design, improves the realism of results, and can prove visual understanding to validate the analysis of flooding.

3D Simulation of External Flooding Events for the RISMC Pathway

Energy Technology Data Exchange (ETDEWEB)

Prescott, Steven [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sampath, Ramprasad [Idaho National Lab. (INL), Idaho Falls, ID (United States); Smith, Curtis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lin, Linyu [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-09-01

Incorporating 3D simulations as part of the Risk-Informed Safety Margins Characterization (RISMIC) Toolkit allows analysts to obtain a more complete picture of complex system behavior for events including external plant hazards. External events such as flooding have become more important recently – however these can be analyzed with existing and validated simulated physics toolkits. In this report, we describe these approaches specific to flooding-based analysis using an approach called Smoothed Particle Hydrodynamics. The theory, validation, and example applications of the 3D flooding simulation are described. Integrating these 3D simulation methods into computational risk analysis provides a spatial/visual aspect to the design, improves the realism of results, and can prove visual understanding to validate the analysis of flooding.

Derivation and External Validation of Prediction Models for Advanced Chronic Kidney Disease Following Acute Kidney Injury.

Science.gov (United States)

James, Matthew T; Pannu, Neesh; Hemmelgarn, Brenda R; Austin, Peter C; Tan, Zhi; McArthur, Eric; Manns, Braden J; Tonelli, Marcello; Wald, Ron; Quinn, Robert R; Ravani, Pietro; Garg, Amit X

2017-11-14

Some patients will develop chronic kidney disease after a hospitalization with acute kidney injury; however, no risk-prediction tools have been developed to identify high-risk patients requiring follow-up. To derive and validate predictive models for progression of acute kidney injury to advanced chronic kidney disease. Data from 2 population-based cohorts of patients with a prehospitalization estimated glomerular filtration rate (eGFR) of more than 45 mL/min/1.73 m2 and who had survived hospitalization with acute kidney injury (defined by a serum creatinine increase during hospitalization > 0.3 mg/dL or > 50% of their prehospitalization baseline), were used to derive and validate multivariable prediction models. The risk models were derived from 9973 patients hospitalized in Alberta, Canada (April 2004-March 2014, with follow-up to March 2015). The risk models were externally validated with data from a cohort of 2761 patients hospitalized in Ontario, Canada (June 2004-March 2012, with follow-up to March 2013). Demographic, laboratory, and comorbidity variables measured prior to discharge. Advanced chronic kidney disease was defined by a sustained reduction in eGFR less than 30 mL/min/1.73 m2 for at least 3 months during the year after discharge. All participants were followed up for up to 1 year. The participants (mean [SD] age, 66 [15] years in the derivation and internal validation cohorts and 69 [11] years in the external validation cohort; 40%-43% women per cohort) had a mean (SD) baseline serum creatinine level of 1.0 (0.2) mg/dL and more than 20% had stage 2 or 3 acute kidney injury. Advanced chronic kidney disease developed in 408 (2.7%) of 9973 patients in the derivation cohort and 62 (2.2%) of 2761 patients in the external validation cohort. In the derivation cohort, 6 variables were independently associated with the outcome: older age, female sex, higher baseline serum creatinine value, albuminuria, greater severity of acute kidney injury, and higher

The relationship between external and internal validity of randomized controlled trials: A sample of hypertension trials from China

Directory of Open Access Journals (Sweden)

Xin Zhang

2015-10-01

Conclusion: Several components relate to the external validity of RCTs do associate with the internal validity, that do not stand in an easy relationship to each other. Regarding the poor reporting, other possible links between two variables need to trace in the future methodological researches.

Predicting Overall Survival After Stereotactic Ablative Radiation Therapy in Early-Stage Lung Cancer: Development and External Validation of the Amsterdam Prognostic Model

Energy Technology Data Exchange (ETDEWEB)

Louie, Alexander V., E-mail: Dr.alexlouie@gmail.com [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands); Department of Radiation Oncology, London Regional Cancer Program, University of Western Ontario, London, Ontario (Canada); Department of Epidemiology, Harvard School of Public Health, Harvard University, Boston, Massachusetts (United States); Haasbeek, Cornelis J.A. [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands); Mokhles, Sahar [Department of Cardio-Thoracic Surgery, Erasmus University Medical Center, Rotterdam (Netherlands); Rodrigues, George B. [Department of Radiation Oncology, London Regional Cancer Program, University of Western Ontario, London, Ontario (Canada); Stephans, Kevin L. [Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Lagerwaard, Frank J. [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands); Palma, David A. [Department of Radiation Oncology, London Regional Cancer Program, University of Western Ontario, London, Ontario (Canada); Videtic, Gregory M.M. [Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Warner, Andrew [Department of Radiation Oncology, London Regional Cancer Program, University of Western Ontario, London, Ontario (Canada); Takkenberg, Johanna J.M. [Department of Cardio-Thoracic Surgery, Erasmus University Medical Center, Rotterdam (Netherlands); Reddy, Chandana A. [Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Maat, Alex P.W.M. [Department of Cardio-Thoracic Surgery, Erasmus University Medical Center, Rotterdam (Netherlands); Woody, Neil M. [Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Slotman, Ben J.; Senan, Suresh [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands)

2015-09-01

Purpose: A prognostic model for 5-year overall survival (OS), consisting of recursive partitioning analysis (RPA) and a nomogram, was developed for patients with early-stage non-small cell lung cancer (ES-NSCLC) treated with stereotactic ablative radiation therapy (SABR). Methods and Materials: A primary dataset of 703 ES-NSCLC SABR patients was randomly divided into a training (67%) and an internal validation (33%) dataset. In the former group, 21 unique parameters consisting of patient, treatment, and tumor factors were entered into an RPA model to predict OS. Univariate and multivariate models were constructed for RPA-selected factors to evaluate their relationship with OS. A nomogram for OS was constructed based on factors significant in multivariate modeling and validated with calibration plots. Both the RPA and the nomogram were externally validated in independent surgical (n=193) and SABR (n=543) datasets. Results: RPA identified 2 distinct risk classes based on tumor diameter, age, World Health Organization performance status (PS) and Charlson comorbidity index. This RPA had moderate discrimination in SABR datasets (c-index range: 0.52-0.60) but was of limited value in the surgical validation cohort. The nomogram predicting OS included smoking history in addition to RPA-identified factors. In contrast to RPA, validation of the nomogram performed well in internal validation (r{sup 2}=0.97) and external SABR (r{sup 2}=0.79) and surgical cohorts (r{sup 2}=0.91). Conclusions: The Amsterdam prognostic model is the first externally validated prognostication tool for OS in ES-NSCLC treated with SABR available to individualize patient decision making. The nomogram retained strong performance across surgical and SABR external validation datasets. RPA performance was poor in surgical patients, suggesting that 2 different distinct patient populations are being treated with these 2 effective modalities.

The Main Concept Analysis in Cantonese Aphasic Oral Discourse: External Validation and Monitoring Chronic Aphasia

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Kong, Anthony Pak-Hin

2011-01-01

Purpose: The 1st aim of this study was to further establish the external validity of the main concept (MC) analysis by examining its relationship with the Cantonese Linguistic Communication Measure (CLCM; Kong, 2006; Kong & Law, 2004)--an established quantitative system for narrative production--and the Cantonese version of the Western Aphasia…

Poor quality of external validity reporting limits generalizability of overweight and/or obesity lifestyle prevention interventions in young adults: a systematic review.

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Partridge, S R; Juan, S J-H; McGeechan, K; Bauman, A; Allman-Farinelli, M

2015-01-01

Young adulthood is a high-risk life stage for weight gain. Evidence is needed to translate behavioural approaches into community practice to prevent weight gain in young adults. This systematic review assessed the effectiveness and reporting of external validity components in prevention interventions. The search was limited to randomized controlled trial (RCT) lifestyle interventions for the prevention of weight gain in young adults (18-35 years). Mean body weight and/or body mass index (BMI) change were the primary outcomes. External validity, quality assessment and risk of bias tools were applied to all studies. Twenty-one RCTs were identified through 14 major electronic databases. Over half of the studies were effective in the short term for significantly reducing body weight and/or BMI; however, few showed long-term maintenance. All studies lacked full reporting on external validity components. Description of the intervention components and participant attrition rates were reported by most studies. However, few studies reported the representativeness of participants, effectiveness of recruitment methods, process evaluation detail or costs. It is unclear from the information reported how to implement the interventions into community practice. Integrated reporting of intervention effectiveness and enhanced reporting of external validity components are needed for the translation and potential upscale of prevention strategies. © 2014 World Obesity.

External validation of a normal tissue complication probability model for radiation-induced hypothyroidism in an independent cohort

DEFF Research Database (Denmark)

Rønjom, Marianne F; Brink, Carsten; Bentzen, Søren M

2015-01-01

blood tests in the validation cohort relative to the original cohort. However, Pearson's correlation coefficients between model and clinical outcome were high: r = 0.97 estimated by the original model versus the original cohort, and r = 0.97 estimated by the original model versus the new cohort....... CONCLUSION: Dmean and Vthyroid were significant predictors of RIHT in both cohorts. The original NTCP model demonstrated external validity owing to high Pearson's correlation coefficients between estimated and observed incidence rates of RIHT in the original as well as in the validation cohort. This model...

Externalizing disorders: cluster 5 of the proposed meta-structure for DSM-V and ICD-11.

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Krueger, R F; South, S C

2009-12-01

The extant major psychiatric classifications DSM-IV and ICD-10 are purportedly atheoretical and largely descriptive. Although this achieves good reliability, the validity of a medical diagnosis is greatly enhanced by an understanding of the etiology. In an attempt to group mental disorders on the basis of etiology, five clusters have been proposed. We consider the validity of the fifth cluster, externalizing disorders, within this proposal. We reviewed the literature in relation to 11 validating criteria proposed by the Study Group of the DSM-V Task Force, in terms of the extent to which these criteria support the idea of a coherent externalizing spectrum of disorders. This cluster distinguishes itself by the central role of disinhibitory personality in mental disorders spread throughout sections of the current classifications, including substance dependence, antisocial personality disorder and conduct disorder. Shared biomarkers, co-morbidity and course offer additional evidence for a valid cluster of externalizing disorders. Externalizing disorders meet many of the salient criteria proposed by the Study Group of the DSM-V Task Force to suggest a classification cluster.

Do we understand children's restlessness? Constructing ecologically valid understandings through reflexive cooperation

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Anna Helle-Valle

2015-12-01

Full Text Available Attention-deficit/hyperactivity disorder (ADHD is the most widely used children's mental health diagnosis today, but the validity of the diagnosis is controversial, for instance, because it might conceal relational and ecological dimensions of restlessness. We invited parents and professionals from one local community in western Norway to participate in cooperative group discussions on how to conceptualize and understand children's restlessness. We carried out a thematic and reflexive analysis of the cooperative group discussions on ADHD and children's restlessness, and present findings related to three ecological levels inspired by Bronfenbrenner's ecological systems model. At the level of the individual, restlessness was discussed as individual trait, as the expectation to be seen and heard, and as a result of traumatization. At the level of dyad, group or family, restlessness was discussed as a relational phenomenon and as parents' problems. At the level of community, restlessness was discussed as lack of cooperation and lack of structures or resources. Our findings show how contextualized and cooperative reflexivity can contribute to more valid understandings of children's restlessness, and how cooperative inquiry can stimulate reflections about solidarity and sustainability in relation to adult's actions.

Prognosis in moderate and severe traumatic brain injury: External validation of the IMPACT models and the role of extracranial injuries

NARCIS (Netherlands)

Lingsma, Hester; Andriessen, Teuntje M. J. C.; Haitsema, Iain; Horn, Janneke; van der Naalt, Joukje; Franschman, Gaby; Maas, Andrew I. R.; Vos, Pieter E.; Steyerberg, Ewout W.

2013-01-01

BACKGROUND: Several prognostic models to predict outcome in traumatic brain injury (TBI) have been developed, but few are externally validated. We aimed to validate the International Mission on Prognosis and Analysis of Clinical Trials in TBI (IMPACT) prognostic models in a recent unselected patient

Development and Validation of a Mobile Device-based External Ventricular Drain Simulator.

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Morone, Peter J; Bekelis, Kimon; Root, Brandon K; Singer, Robert J

2017-10-01

Multiple external ventricular drain (EVD) simulators have been created, yet their cost, bulky size, and nonreusable components limit their accessibility to residency programs. To create and validate an animated EVD simulator that is accessible on a mobile device. We developed a mobile-based EVD simulator that is compatible with iOS (Apple Inc., Cupertino, California) and Android-based devices (Google, Mountain View, California) and can be downloaded from the Apple App and Google Play Store. Our simulator consists of a learn mode, which teaches users the procedure, and a test mode, which assesses users' procedural knowledge. Twenty-eight participants, who were divided into expert and novice categories, completed the simulator in test mode and answered a postmodule survey. This was graded using a 5-point Likert scale, with 5 representing the highest score. Using the survey results, we assessed the module's face and content validity, whereas construct validity was evaluated by comparing the expert and novice test scores. Participants rated individual survey questions pertaining to face and content validity a median score of 4 out of 5. When comparing test scores, generated by the participants completing the test mode, the experts scored higher than the novices (mean, 71.5; 95% confidence interval, 69.2 to 73.8 vs mean, 48; 95% confidence interval, 44.2 to 51.6; P mobile-based EVD simulator that is inexpensive, reusable, and accessible. Our results demonstrate that this simulator is face, content, and construct valid. Copyright © 2017 by the Congress of Neurological Surgeons

External validation of blood eosinophils, FE(NO) and serum periostin as surrogates for sputum eosinophils in asthma.

Science.gov (United States)

Wagener, A H; de Nijs, S B; Lutter, R; Sousa, A R; Weersink, E J M; Bel, E H; Sterk, P J

2015-02-01

Monitoring sputum eosinophils in asthma predicts exacerbations and improves management of asthma. Thus far, blood eosinophils and FE(NO) show contradictory results in predicting eosinophilic airway inflammation. More recently, serum periostin was proposed as a novel biomarker for eosinophilic inflammation. Quantifying the mutual relationships of blood eosinophils, FE(NO), and serum periostin with sputum eosinophils by external validation in two independent cohorts across various severities of asthma. The first cohort consisted of 110 patients with mild to moderate asthma (external validation cohort). The replication cohort consisted of 37 patients with moderate to severe asthma. Both cohorts were evaluated cross-sectionally. Sputum was induced for the assessment of eosinophils. In parallel, blood eosinophil counts, serum periostin concentrations and FENO were assessed. The diagnostic accuracy of these markers to identify eosinophilic asthma (sputum eosinophils ≥3%) was calculated using receiver operating characteristics area under the curve (ROC AUC). In the external validation cohort, ROC AUC for blood eosinophils was 89% (peosinophilic from non-eosinophilic airway inflammation (ROC AUC=55%, p=0.44). When combining these three variables, no improvement was seen. The diagnostic value of blood eosinophils was confirmed in the replication cohort (ROC AUC 85%, peosinophils had the highest accuracy in the identification of sputum eosinophilia in asthma. The use of blood eosinophils can facilitate individualised treatment and management of asthma. NTR1846 and NTR2364. 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.

Measuring striving for understanding and learning value of geometry: a validity study

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Ubuz, Behiye; Aydınyer, Yurdagül

2017-11-01

The current study aimed to construct a questionnaire that measures students' personality traits related to striving for understanding and learning value of geometry and then examine its psychometric properties. Through the use of multiple methods on two independent samples of 402 and 521 middle school students, two studies were performed to address this issue to provide support for its validity. In Study 1, exploratory factor analysis indicated the two-factor model. In Study 2, confirmatory factor analysis indicated the better fit of two-factor model compared to one or three-factor model. Convergent and discriminant validity evidence provided insight into the distinctiveness of the two factors. Subgroup validity evidence revealed gender differences for striving for understanding geometry trait favouring girls and grade level differences for learning value of geometry trait favouring the sixth- and seventh-grade students. Predictive validity evidence demonstrated that the striving for understanding geometry trait but not learning value of geometry trait was significantly correlated with prior mathematics achievement. In both studies, each factor and the entire questionnaire showed satisfactory reliability. In conclusion, the questionnaire was psychometrically sound.

Multicentre validation of IMRT pre-treatment verification: Comparison of in-house and external audit

International Nuclear Information System (INIS)

Jornet, Núria; Carrasco, Pablo; Beltrán, Mercè; Calvo, Juan Francisco; Escudé, Lluís; Hernández, Victor; Quera, Jaume; Sáez, Jordi

2014-01-01

Background and purpose: We performed a multicentre intercomparison of IMRT optimisation and dose planning and IMRT pre-treatment verification methods and results. The aims were to check consistency between dose plans and to validate whether in-house pre-treatment verification results agreed with those of an external audit. Materials and methods: Participating centres used two mock cases (prostate and head and neck) for the intercomparison and audit. Compliance to dosimetric goals and total number of MU per plan were collected. A simple quality index to compare the different plans was proposed. We compared gamma index pass rates using the centre’s equipment and methodology to those of an external audit. Results: While for the prostate case, all centres fulfilled the dosimetric goals and plan quality was homogeneous, that was not the case for the head and neck case. The number of MU did not correlate with the plan quality index. Pre-treatment verifications results of the external audit did not agree with those of the in-house measurements for two centres: being within tolerance for in-house measurements and unacceptable for the audit or the other way round. Conclusions: Although all plans fulfilled dosimetric constraints, plan quality is highly dependent on the planner expertise. External audits are an excellent tool to detect errors in IMRT implementation and cannot be replaced by intercomparison using results obtained by centres

Assessing Students' Understanding of Macroevolution: Concerns regarding the validity of the MUM

Science.gov (United States)

Novick, Laura R.; Catley, Kefyn M.

2012-11-01

In a recent article, Nadelson and Southerland (2010. Development and preliminary evaluation of the Measure of Understanding of Macroevolution: Introducing the MUM. The Journal of Experimental Education, 78, 151-190) reported on their development of a multiple-choice concept inventory intended to assess college students' understanding of macroevolutionary concepts, the Measure of Understanding Macroevolution (MUM). Given that the only existing evolution inventories assess understanding of natural selection, a microevolutionary concept, a valid assessment of students' understanding of macroevolution would be a welcome and necessary addition to the field of science education. Although the conceptual framework underlying Nadelson and Southerland's test is promising, we believe the test has serious shortcomings with respect to validity evidence for the construct being tested. We argue and provide evidence that these problems are serious enough that the MUM should not be used in its current form to measure students' understanding of macroevolution.

Development and external validation of a risk-prediction model to predict 5-year overall survival in advanced larynx cancer.

Science.gov (United States)

Petersen, Japke F; Stuiver, Martijn M; Timmermans, Adriana J; Chen, Amy; Zhang, Hongzhen; O'Neill, James P; Deady, Sandra; Vander Poorten, Vincent; Meulemans, Jeroen; Wennerberg, Johan; Skroder, Carl; Day, Andrew T; Koch, Wayne; van den Brekel, Michiel W M

2018-05-01

TNM-classification inadequately estimates patient-specific overall survival (OS). We aimed to improve this by developing a risk-prediction model for patients with advanced larynx cancer. Cohort study. We developed a risk prediction model to estimate the 5-year OS rate based on a cohort of 3,442 patients with T3T4N0N+M0 larynx cancer. The model was internally validated using bootstrapping samples and externally validated on patient data from five external centers (n = 770). The main outcome was performance of the model as tested by discrimination, calibration, and the ability to distinguish risk groups based on tertiles from the derivation dataset. The model performance was compared to a model based on T and N classification only. We included age, gender, T and N classification, and subsite as prognostic variables in the standard model. After external validation, the standard model had a significantly better fit than a model based on T and N classification alone (C statistic, 0.59 vs. 0.55, P statistic to 0.68. A risk prediction model for patients with advanced larynx cancer, consisting of readily available clinical variables, gives more accurate estimations of the estimated 5-year survival rate when compared to a model based on T and N classification alone. 2c. Laryngoscope, 128:1140-1145, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

SU-C-BRF-05: Design and Geometric Validation of An Externally and Internally Deformable, Programmable Lung Motion Phantom

International Nuclear Information System (INIS)

Cheung, Y; Sawant, A

2014-01-01

Purpose: Most clinically-deployed strategies for respiratory motion management in lung radiotherapy (e.g., gating, tracking) use external markers that serve as surrogates for tumor motion. However, typical lung phantoms used to validate these strategies are rigid-exterior+rigid-interior or rigid-exterior+deformable-interior. Neither class adequately represents the human anatomy, which is deformable internally as well as externally. We describe the construction and experimental validation of a more realistic, externally- and internally-deformable, programmable lung phantom. Methods: The outer shell of a commercially-available lung phantom (RS- 1500, RSD Inc.) was used. The shell consists of a chest cavity with a flexible anterior surface, and embedded vertebrae, rib-cage and sternum. A 3-axis platform was programmed with sinusoidal and six patient-recorded lung tumor trajectories. The platform was used to drive a rigid foam ‘diaphragm’ that compressed/decompressed the phantom interior. Experimental characterization comprised of mapping the superior-inferior (SI) and anterior-posterior (AP) trajectories of external and internal radioopaque markers with kV x-ray fluoroscopy and correlating these with optical surface monitoring using the in-room VisionRT system. Results: The phantom correctly reproduced the programmed motion as well as realistic effects such as hysteresis. The reproducibility of marker trajectories over multiple runs for sinusoidal as well as patient traces, as characterized by fluoroscopy, was within 0.4 mm RMS error for internal as well as external markers. The motion trajectories of internal and external markers as measured by fluoroscopy were found to be highly correlated (R=0.97). Furthermore, motion trajectories of arbitrary points on the deforming phantom surface, as recorded by the VisionRT system also showed a high correlation with respect to the fluoroscopically-measured trajectories of internal markers (R=0.92). Conclusion: We have

External validation of models predicting the individual risk of metachronous peritoneal carcinomatosis from colon and rectal cancer.

Science.gov (United States)

Segelman, J; Akre, O; Gustafsson, U O; Bottai, M; Martling, A

2016-04-01

To externally validate previously published predictive models of the risk of developing metachronous peritoneal carcinomatosis (PC) after resection of nonmetastatic colon or rectal cancer and to update the predictive model for colon cancer by adding new prognostic predictors. Data from all patients with Stage I-III colorectal cancer identified from a population-based database in Stockholm between 2008 and 2010 were used. We assessed the concordance between the predicted and observed probabilities of PC and utilized proportional-hazard regression to update the predictive model for colon cancer. When applied to the new validation dataset (n = 2011), the colon and rectal cancer risk-score models predicted metachronous PC with a concordance index of 79% and 67%, respectively. After adding the subclasses of pT3 and pT4 stage and mucinous tumour to the colon cancer model, the concordance index increased to 82%. In validation of external and recent cohorts, the predictive accuracy was strong in colon cancer and moderate in rectal cancer patients. The model can be used to identify high-risk patients for planned second-look laparoscopy/laparotomy for possible subsequent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Colorectal Disease © 2015 The Association of Coloproctology of Great Britain and Ireland.

External Validity of Randomized Controlled Trials on Alzheimer’s Disease: The Biases of Frailty and Biological Aging

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Marco Canevelli

2017-11-01

Full Text Available To date, the external validity of randomized controlled trials (RCTs on Alzheimer’s disease (AD has been assessed only considering monodimensional variables. Nevertheless, looking at isolated and single characteristics cannot guarantee a sufficient level of appreciation of the AD patients’ complexity. The only way to understand whether the two worlds (i.e., research and clinics deal with the same type of patients is to adopt multidimensional approaches more holistically reflecting the biological age of the individual. In the present study, we compared measures of frailty/biological aging [assessed by a Frailty Index (FI] of a sample of patients with AD resulted eligible and subsequently included in phase III RCTs compared to patients referring to the same clinical service, but not considered for inclusion. The “RCT sample” and the “real world sample” were found to be statistically similar for all the considered sociodemographic and clinical variables. Nevertheless, the “real world sample” was found to be significantly frailer compared to the “RCT sample,” as indicated by higher FI scores [0.28 (SD 0.1 vs. 0.17 (SD 0.1; p < 0.001, respectively]. Moreover, when assessing the relationship between FI and age, we found that the correlation was almost null in the “RCT sample” (Spearman’s r = 0.01; p = 0.98, while it was statistically significant in the “real world sample” (r = 0.49; p = 0.02. The application of too rigid designs may result in the poor representativeness of RCT samples. It may even imply the study of a condition biologically different from that observed in the “real world.” The adoption of multidimensional measures capable to capture the individual’s biological age may facilitate evaluating the external validity of clinical studies, implicitly improving the interpretation of the results and their translation in the clinical arena.

Psychological capital: Internal and external validity of the Psychological Capital Questionnaire (PCQ-24 on a South African sample

Directory of Open Access Journals (Sweden)

Gina Görgens-Ekermans

2013-10-01

Research purpose: The objectives of this study were to investigate the internal validity (construct and discriminant validity, reliability and external validity (relationship with theoretically relevant variables, namely stress, burnout and work engagement of the PCQ-24. Motivation for the study: Multiple studies have underscored the value of PsyCap within the workplace. In order to harness the full potential of the construct in the South African environment, sound measurement thereof, evidenced by a psychometrically sound instrument, is needed. Research design, approach and method: A cross-sectional survey design was used. The sample consisted of employees at managerial and non-managerial levels, from a medium-sized construction company in the Western Cape, South Africa. In addition to PsyCap, perceived stress, work-related burnout and work engagement were measured. Main findings: The results provided preliminary evidence of construct and discriminant validity, reliability and significant relations with external theoretically relevant variables. Practical/managerial implications: Researchers may confidently use the PCQ-24 to measure the construct of PsyCap and investigate relations with workplace outcomes in the South African environment, informing human relations practices. Contribution/value-add: Preliminary evidence of the psychometric properties of the PCQ-24, which measures the construct of PsyCap (consisting of hope, self-efficacy, resilience and optimism on a South African sample, was provided in this study.

A Psychometric Validation of the Internal and External Motivation to Respond without Prejudice toward People with Disabilities Scale

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Pruett, Steven R.; Deiches, Jon; Pfaller, Joseph; Moser, Erin; Chan, Fong

2014-01-01

Objective: To determine the factorial validity of the Internal and External Motivation to Respond without Prejudice toward People with Disabilities Scale (D-IMS/EMS). Design: A quantitative descriptive design using factor analysis. Participants: 233 rehabilitation counseling and rehabilitation services students. Results: Both exploratory and…

External validity of sentiment mining reports: Can current methods identify demographic biases, event biases, and manipulation of reviews?

NARCIS (Netherlands)

Wijnhoven, Alphonsus B.J.M.; Bloemen, Oscar

2014-01-01

Many publications in sentiment mining provide new techniques for improved accuracy in extracting features and corresponding sentiments in texts. For the external validity of these sentiment reports, i.e., the applicability of the results to target audiences, it is important to well analyze data of

Assessing the external validity of model-based estimates of the incidence of heart attack in England: a modelling study

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Peter Scarborough

2016-11-01

Full Text Available Abstract Background The DisMod II model is designed to estimate epidemiological parameters on diseases where measured data are incomplete and has been used to provide estimates of disease incidence for the Global Burden of Disease study. We assessed the external validity of the DisMod II model by comparing modelled estimates of the incidence of first acute myocardial infarction (AMI in England in 2010 with estimates derived from a linked dataset of hospital records and death certificates. Methods Inputs for DisMod II were prevalence rates of ever having had an AMI taken from a population health survey, total mortality rates and AMI mortality rates taken from death certificates. By definition, remission rates were zero. We estimated first AMI incidence in an external dataset from England in 2010 using a linked dataset including all hospital admissions and death certificates since 1998. 95 % confidence intervals were derived around estimates from the external dataset and DisMod II estimates based on sampling variance and reported uncertainty in prevalence estimates respectively. Results Estimates of the incidence rate for the whole population were higher in the DisMod II results than the external dataset (+54 % for men and +26 % for women. Age-specific results showed that the DisMod II results over-estimated incidence for all but the oldest age groups. Confidence intervals for the DisMod II and external dataset estimates did not overlap for most age groups. Conclusion By comparison with AMI incidence rates in England, DisMod II did not achieve external validity for age-specific incidence rates, but did provide global estimates of incidence that are of similar magnitude to measured estimates. The model should be used with caution when estimating age-specific incidence rates.

External Validity and Model Validity: A Conceptual Approach for Systematic Review Methodology

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Raheleh Khorsan

2014-01-01

Full Text Available Background. Evidence rankings do not consider equally internal (IV, external (EV, and model validity (MV for clinical studies including complementary and alternative medicine/integrative health care (CAM/IHC research. This paper describe this model and offers an EV assessment tool (EVAT© for weighing studies according to EV and MV in addition to IV. Methods. An abbreviated systematic review methodology was employed to search, assemble, and evaluate the literature that has been published on EV/MV criteria. Standard databases were searched for keywords relating to EV, MV, and bias-scoring from inception to Jan 2013. Tools identified and concepts described were pooled to assemble a robust tool for evaluating these quality criteria. Results. This study assembled a streamlined, objective tool to incorporate for the evaluation of quality of EV/MV research that is more sensitive to CAM/IHC research. Conclusion. Improved reporting on EV can help produce and provide information that will help guide policy makers, public health researchers, and other scientists in their selection, development, and improvement in their research-tested intervention. Overall, clinical studies with high EV have the potential to provide the most useful information about “real-world” consequences of health interventions. It is hoped that this novel tool which considers IV, EV, and MV on equal footing will better guide clinical decision making.

External validation and clinical utility of a prediction model for 6-month mortality in patients undergoing hemodialysis for end-stage kidney disease.

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Forzley, Brian; Er, Lee; Chiu, Helen Hl; Djurdjev, Ognjenka; Martinusen, Dan; Carson, Rachel C; Hargrove, Gaylene; Levin, Adeera; Karim, Mohamud

2018-02-01

End-stage kidney disease is associated with poor prognosis. Health care professionals must be prepared to address end-of-life issues and identify those at high risk for dying. A 6-month mortality prediction model for patients on dialysis derived in the United States is used but has not been externally validated. We aimed to assess the external validity and clinical utility in an independent cohort in Canada. We examined the performance of the published 6-month mortality prediction model, using discrimination, calibration, and decision curve analyses. Data were derived from a cohort of 374 prevalent dialysis patients in two regions of British Columbia, Canada, which included serum albumin, age, peripheral vascular disease, dementia, and answers to the "the surprise question" ("Would I be surprised if this patient died within the next year?"). The observed mortality in the validation cohort was 11.5% at 6 months. The prediction model had reasonable discrimination (c-stat = 0.70) but poor calibration (calibration-in-the-large = -0.53 (95% confidence interval: -0.88, -0.18); calibration slope = 0.57 (95% confidence interval: 0.31, 0.83)) in our data. Decision curve analysis showed the model only has added value in guiding clinical decision in a small range of threshold probabilities: 8%-20%. Despite reasonable discrimination, the prediction model has poor calibration in this external study cohort; thus, it may have limited clinical utility in settings outside of where it was derived. Decision curve analysis clarifies limitations in clinical utility not apparent by receiver operating characteristic curve analysis. This study highlights the importance of external validation of prediction models prior to routine use in clinical practice.

External validation of approaches to prediction of falls during hospital rehabilitation stays and development of a new simpler tool

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Angela Vratsistas-Curto

2017-12-01

Full Text Available Objectives: To test the external validity of 4 approaches to fall prediction in a rehabilitation setting (Predict_FIRST, Ontario Modified STRATIFY (OMS, physiotherapists’ judgement of fall risk (PT_Risk, and falls in the past year (Past_Falls, and to develop and test the validity of a simpler tool for fall prediction in rehabilitation (Predict_CM2. Participants: A total of 300 consecutively-admitted rehabilitation inpatients. Methods: Prospective inception cohort study. Falls during the rehabilitation stay were monitored. Potential predictors were extracted from medical records. Results: Forty-one patients (14% fell during their rehabilitation stay. The external validity, area under the receiver operating characteristic curve (AUC, for predicting future fallers was: 0.71 (95% confidence interval (95% CI: 0.61–0.81 for OMS (Total_Score; 0.66 (95% CI: 0.57–0.74 for Predict_FIRST; 0.65 (95% CI 0.57–0.73 for PT_Risk; and 0.52 for Past_Falls (95% CI: 0.46–0.60. A simple 3-item tool (Predict_CM2 was developed from the most predictive individual items (impaired mobility/transfer ability, impaired cognition, and male sex. The accuracy of Predict_CM2 was 0.73 (95% CI: 0.66–0.81, comparable to OMS (Total_Score (p = 0.52, significantly better than Predict_FIRST (p = 0.04, and Past_Falls (p < 0.001, and approaching significantly better than PT_Risk (p = 0.09. Conclusion: Predict_CM2 is a simpler screening tool with similar accuracy for predicting fallers in rehabilitation to OMS (Total_Score and better accuracy than Predict_FIRST or Past_Falls. External validation of Predict_CM2 is required.

Towards Better Understanding QBism.

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Khrennikov, Andrei

2018-01-01

Recently I posted a paper entitled "External observer reflections on QBism". As any external observer, I was not able to reflect all features of QBism properly. The comments I received from one of QBism's creators, C. A. Fuchs, were very valuable to me in better understanding the views of QBists. Some of QBism's features are very delicate and extracting them from articles of QBists is not a simple task. Therefore, I hope that the second portion of my reflections on QBism (or, strictly speaking, my reflections on Fuchs reflections on my earlier reflections) might be interesting and useful for other experts in quantum foundations and quantum information theory (especially, taking into account my previous aggressively anti-QBism position). In the present paper I correct some of my earlier posted critical comments on QBism. At the same time, other critical comments gained new validation through my recent deeper understanding of QBists views on a number of problems.

Validation of the prognostic gene portfolio, ClinicoMolecular Triad Classification, using an independent prospective breast cancer cohort and external patient populations.

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Wang, Dong-Yu; Done, Susan J; Mc Cready, David R; Leong, Wey L

2014-07-04

Using genome-wide expression profiles of a prospective training cohort of breast cancer patients, ClinicoMolecular Triad Classification (CMTC) was recently developed to classify breast cancers into three clinically relevant groups to aid treatment decisions. CMTC was found to be both prognostic and predictive in a large external breast cancer cohort in that study. This study serves to validate the reproducibility of CMTC and its prognostic value using independent patient cohorts. An independent internal cohort (n = 284) and a new external cohort (n = 2,181) were used to validate the association of CMTC between clinicopathological factors, 12 known gene signatures, two molecular subtype classifiers, and 19 oncogenic signalling pathway activities, and to reproduce the abilities of CMTC to predict clinical outcomes of breast cancer. In addition, we also updated the outcome data of the original training cohort (n = 147). The original training cohort reached a statistically significant difference (p value of the triad classification was reproduced in the second independent internal cohort and the new external validation cohort. CMTC achieved even higher prognostic significance when all available patients were analyzed (n = 4,851). Oncogenic pathways Myc, E2F1, Ras and β-catenin were again implicated in the high-risk groups. Both prospective internal cohorts and the independent external cohorts reproduced the triad classification of CMTC and its prognostic significance. CMTC is an independent prognostic predictor, and it outperformed 12 other known prognostic gene signatures, molecular subtype classifications, and all other standard prognostic clinicopathological factors. Our results support further development of CMTC portfolio into a guide for personalized breast cancer treatments.

Predicting the success of IVF: external validation of the van Loendersloot's model.

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Sarais, Veronica; Reschini, Marco; Busnelli, Andrea; Biancardi, Rossella; Paffoni, Alessio; Somigliana, Edgardo

2016-06-01

Is the predictive model for IVF success proposed by van Loendersloot et al. valid in a different geographical and cultural context? The model discriminates well but was less accurate than in the original context where it was developed. Several independent groups have developed models that combine different variables with the aim of estimating the chance of pregnancy with IVF but only four of them have been externally validated. One of these four, the van Loendersloot's model, deserves particular attention and further investigation for at least three reasons; (i) the reported area under the receiver operating characteristics curve (c-statistics) in the temporal validation setting was the highest reported to date (0.68), (ii) the perspective of the model is clinically wise since it includes variables obtained from previous failed cycles, if any, so it can be applied to any women entering an IVF cycle, (iii) the model lacks external validation in a geographically different center. Retrospective cohort study of women undergoing oocyte retrieval for IVF between January 2013 and December 2013 at the infertility unit of the Fondazione Ca' Granda, Ospedale Maggiore Policlinico of Milan, Italy. Only the first oocyte retrieval cycle performed during the study period was included in the study. Women with previous IVF cycles were excluded if the last one before the study cycle was in another center. The main outcome was the cumulative live birth rate per oocytes retrieval. Seven hundred seventy-two women were selected. Variables included in the van Loendersloot's model and the relative weights (beta) were used. The variable resulting from this combination (Y) was transformed into a probability. The discriminatory capacity was assessed using the c-statistics. Calibration was made using a logistic regression that included Y as the unique variable and live birth as the outcome. Data are presented using both the original and the calibrated models. Performance was evaluated

External Validation of Prediction Models for Pneumonia in Primary Care Patients with Lower Respiratory Tract Infection

DEFF Research Database (Denmark)

Schierenberg, Alwin; Minnaard, Margaretha C; Hopstaken, Rogier M

2016-01-01

BACKGROUND: Pneumonia remains difficult to diagnose in primary care. Prediction models based on signs and symptoms (S&S) serve to minimize the diagnostic uncertainty. External validation of these models is essential before implementation into routine practice. In this study all published S&S mode...... discriminative accuracy coupled with reasonable to good calibration across the IPD of different study populations. This model is therefore the main candidate for primary care use....

Predicting new service adoption with conjoint analysis : External validity of BDM-based incentive-aligned and dual-response choice designs

NARCIS (Netherlands)

Wlömert, Nils; Eggers, Felix

2016-01-01

In this paper, we compare the standard, single-response choice-based con- joint (CBC) approach with three extended CBC procedures in terms of their external predictive validity and their ability to realistically capture consumers’ willingness to pay: (1) an incentive-aligned CBC mechanism (IA-CBC),

External validation of prognostic models to predict risk of gestational diabetes mellitus in one Dutch cohort: prospective multicentre cohort study.

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Lamain-de Ruiter, Marije; Kwee, Anneke; Naaktgeboren, Christiana A; de Groot, Inge; Evers, Inge M; Groenendaal, Floris; Hering, Yolanda R; Huisjes, Anjoke J M; Kirpestein, Cornel; Monincx, Wilma M; Siljee, Jacqueline E; Van 't Zelfde, Annewil; van Oirschot, Charlotte M; Vankan-Buitelaar, Simone A; Vonk, Mariska A A W; Wiegers, Therese A; Zwart, Joost J; Franx, Arie; Moons, Karel G M; Koster, Maria P H

2016-08-30

 To perform an external validation and direct comparison of published prognostic models for early prediction of the risk of gestational diabetes mellitus, including predictors applicable in the first trimester of pregnancy.  External validation of all published prognostic models in large scale, prospective, multicentre cohort study.  31 independent midwifery practices and six hospitals in the Netherlands.  Women recruited in their first trimester (diabetes mellitus of any type were excluded.  Discrimination of the prognostic models was assessed by the C statistic, and calibration assessed by calibration plots.  3723 women were included for analysis, of whom 181 (4.9%) developed gestational diabetes mellitus in pregnancy. 12 prognostic models for the disorder could be validated in the cohort. C statistics ranged from 0.67 to 0.78. Calibration plots showed that eight of the 12 models were well calibrated. The four models with the highest C statistics included almost all of the following predictors: maternal age, maternal body mass index, history of gestational diabetes mellitus, ethnicity, and family history of diabetes. Prognostic models had a similar performance in a subgroup of nulliparous women only. Decision curve analysis showed that the use of these four models always had a positive net benefit.  In this external validation study, most of the published prognostic models for gestational diabetes mellitus show acceptable discrimination and calibration. The four models with the highest discriminative abilities in this study cohort, which also perform well in a subgroup of nulliparous women, are easy models to apply in clinical practice and therefore deserve further evaluation regarding their clinical impact. 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.

External validation of the Society of Thoracic Surgeons General Thoracic Surgery Database.

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Magee, Mitchell J; Wright, Cameron D; McDonald, Donna; Fernandez, Felix G; Kozower, Benjamin D

2013-11-01

The Society of Thoracic Surgeons (STS) General Thoracic Surgery Database (GTSD) reports outstanding results for lung and esophageal cancer resection. However, a major weakness of the GTSD has been the lack of validation of this voluntary registry. The purpose of this study was to perform an external, independent audit to assess the accuracy of the data collection process and the quality of the database. An independent firm was contracted to audit 5% of sites randomly selected from the GTDB in 2011. Audits were performed remotely to maximize the number of audits performed and reduce cost. Auditors compared lobectomy cases submitted to the GTSD with the hospital operative logs to evaluate completeness of the data. In addition, 20 lobectomy records from each site were audited in detail. Agreement rates were calculated for 32 individual data elements, 7 data categories pertaining to patient status or care delivery, and an overall agreement rate for each site. Six process variables were also evaluated to assess best practice for data collection and submission. Ten sites were audited from the 222 participants. Comparison of the 559 submitted lobectomy cases with operative logs from each site identified 28 omissions, a 94.6% agreement rate (discrepancies/site range, 2 to 27). Importantly, cases not submitted had no mortality or major morbidity, indicating a lack of purposeful omission. The aggregate agreement rates for all categories were greater than 90%. The overall data accuracy was 94.9%. External audits of the GTSD validate the accuracy and completeness of the data. Careful examination of unreported cases demonstrated no purposeful omission or gaming. Although these preliminary results are quite good, it is imperative that the audit process is refined and continues to expand along with the GTSD to insure reliability of the database. The audit results are currently being incorporated into educational and quality improvement processes to add further value. Copyright �

External validation of the NUn score for predicting anastomotic leakage after oesophageal resection.

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Paireder, Matthias; Jomrich, Gerd; Asari, Reza; Kristo, Ivan; Gleiss, Andreas; Preusser, Matthias; Schoppmann, Sebastian F

2017-08-29

Early detection of anastomotic leakage (AL) after oesophageal resection for malignancy is crucial. This retrospective study validates a risk score, predicting AL, which includes C-reactive protein, albumin and white cell count in patients undergoing oesophageal resection between 2003 and 2014. For validation of the NUn score a receiver operating characteristic (ROC) curve is estimated. Area under the ROC curve (AUC) is reported with 95% confidence interval (CI). Among 258 patients (79.5% male) 32 patients showed signs of anastomotic leakage (12.4%). NUn score in our data has a median of 9.3 (range 6.2-17.6). The odds ratio for AL was 1.31 (CI 1.03-1.67; p = 0.028). AUC for AL was 0.59 (CI 0.47-0.72). Using the original cutoff value of 10, the sensitivity was 45.2% an the specificity was 73.8%. This results in a positive predictive value of 19.4% and a negative predictive value of 90.6%. The proportion of variation in AL occurrence, which is explained by the NUn score, was 2.5% (PEV = 0.025). This study provides evidence for an external validation of a simple risk score for AL after oesophageal resection. In this cohort, the NUn score is not useful due to its poor discrimination.

Students' Understanding of External Representations of the Potassium Ion Channel Protein, Part I: Affordances and Limitations of Ribbon Diagrams, Vines, and Hydrophobic/Polar Representations

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Harle, Marissa; Towns, Marcy H.

2012-01-01

Research on external representations in biochemistry has uncovered student difficulties in comprehending and interpreting external representations. This project focuses on students' understanding of three external representations of the potassium ion channel protein. This is part I of a two-part study, which focuses on the affordances and…

The impact of crowd noise on officiating in Muay Thai: achieving external validity in an experimental setting

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Tony D Myers

2012-09-01

Full Text Available Numerous factors have been proposed to explain the home advantage in sport. Several authors have suggested that a partisan home crowd enhances home advantage and that this is at least in part a consequence of their influence on officiating. However, while experimental studies examining this phenomenon have high levels of internal validity (since only the ‘crowd noise’ intervention is allowed to vary, they suffer from a lack of external validity, with decision-making in a laboratory setting typically bearing little resemblance to decision-making in live sports settings. Conversely, observational and quasi-experimental studies with high levels of external validity suffer from low levels of internal validity as countless factors besides crowd noise vary. The present study provides a unique opportunity to address these criticisms, by conducting a controlled experiment on the impact of crowd noise on officiating in a live tournament setting. Seventeen qualified judges officiated on thirty Thai boxing bouts in a live international tournament setting featuring ‘home’ and ‘away’ boxers. In each bout, judges were randomised into a ‘noise’ (live sound or ‘no crowd noise’ (noise cancelling headphones and white noise condition, resulting in 59 judgements in the ‘no crowd noise’ and 61 in the ‘crowd noise’ condition. The results provide the first experimental evidence of the impact of live crowd noise on officials in sport. A cross-classified statistical model indicated that crowd noise had a statistically significant impact, equating to just over half a point per bout (in the context of five round bouts with the ‘ten point must’ scoring system shared with professional boxing. The practical significance of the findings, their implications for officiating and for the future conduct of crowd noise studies are discussed.

The impact of crowd noise on officiating in muay thai: achieving external validity in an experimental setting.

Science.gov (United States)

Myers, Tony; Balmer, Nigel

2012-01-01

Numerous factors have been proposed to explain the home advantage in sport. Several authors have suggested that a partisan home crowd enhances home advantage and that this is at least in part a consequence of their influence on officiating. However, while experimental studies examining this phenomenon have high levels of internal validity (since only the "crowd noise" intervention is allowed to vary), they suffer from a lack of external validity, with decision-making in a laboratory setting typically bearing little resemblance to decision-making in live sports settings. Conversely, observational and quasi-experimental studies with high levels of external validity suffer from low levels of internal validity as countless factors besides crowd noise vary. The present study provides a unique opportunity to address these criticisms, by conducting a controlled experiment on the impact of crowd noise on officiating in a live tournament setting. Seventeen qualified judges officiated on thirty Thai boxing bouts in a live international tournament setting featuring "home" and "away" boxers. In each bout, judges were randomized into a "noise" (live sound) or "no crowd noise" (noise-canceling headphones and white noise) condition, resulting in 59 judgments in the "no crowd noise" and 61 in the "crowd noise" condition. The results provide the first experimental evidence of the impact of live crowd noise on officials in sport. A cross-classified statistical model indicated that crowd noise had a statistically significant impact, equating to just over half a point per bout (in the context of five round bouts with the "10-point must" scoring system shared with professional boxing). The practical significance of the findings, their implications for officiating and for the future conduct of crowd noise studies are discussed.

Multisite external validation of a risk prediction model for the diagnosis of blood stream infections in febrile pediatric oncology patients without severe neutropenia.

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Esbenshade, Adam J; Zhao, Zhiguo; Aftandilian, Catherine; Saab, Raya; Wattier, Rachel L; Beauchemin, Melissa; Miller, Tamara P; Wilkes, Jennifer J; Kelly, Michael J; Fernbach, Alison; Jeng, Michael; Schwartz, Cindy L; Dvorak, Christopher C; Shyr, Yu; Moons, Karl G M; Sulis, Maria-Luisa; Friedman, Debra L

2017-10-01

Pediatric oncology patients are at an increased risk of invasive bacterial infection due to immunosuppression. The risk of such infection in the absence of severe neutropenia (absolute neutrophil count ≥ 500/μL) is not well established and a validated prediction model for blood stream infection (BSI) risk offers clinical usefulness. A 6-site retrospective external validation was conducted using a previously published risk prediction model for BSI in febrile pediatric oncology patients without severe neutropenia: the Esbenshade/Vanderbilt (EsVan) model. A reduced model (EsVan2) excluding 2 less clinically reliable variables also was created using the initial EsVan model derivative cohort, and was validated using all 5 external validation cohorts. One data set was used only in sensitivity analyses due to missing some variables. From the 5 primary data sets, there were a total of 1197 febrile episodes and 76 episodes of bacteremia. The overall C statistic for predicting bacteremia was 0.695, with a calibration slope of 0.50 for the original model and a calibration slope of 1.0 when recalibration was applied to the model. The model performed better in predicting high-risk bacteremia (gram-negative or Staphylococcus aureus infection) versus BSI alone, with a C statistic of 0.801 and a calibration slope of 0.65. The EsVan2 model outperformed the EsVan model across data sets with a C statistic of 0.733 for predicting BSI and a C statistic of 0.841 for high-risk BSI. The results of this external validation demonstrated that the EsVan and EsVan2 models are able to predict BSI across multiple performance sites and, once validated and implemented prospectively, could assist in decision making in clinical practice. Cancer 2017;123:3781-3790. © 2017 American Cancer Society. © 2017 American Cancer Society.

Real external predictivity of QSAR models: how to evaluate it? Comparison of different validation criteria and proposal of using the concordance correlation coefficient.

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Chirico, Nicola; Gramatica, Paola

2011-09-26

The main utility of QSAR models is their ability to predict activities/properties for new chemicals, and this external prediction ability is evaluated by means of various validation criteria. As a measure for such evaluation the OECD guidelines have proposed the predictive squared correlation coefficient Q(2)(F1) (Shi et al.). However, other validation criteria have been proposed by other authors: the Golbraikh-Tropsha method, r(2)(m) (Roy), Q(2)(F2) (Schüürmann et al.), Q(2)(F3) (Consonni et al.). In QSAR studies these measures are usually in accordance, though this is not always the case, thus doubts can arise when contradictory results are obtained. It is likely that none of the aforementioned criteria is the best in every situation, so a comparative study using simulated data sets is proposed here, using threshold values suggested by the proponents or those widely used in QSAR modeling. In addition, a different and simple external validation measure, the concordance correlation coefficient (CCC), is proposed and compared with other criteria. Huge data sets were used to study the general behavior of validation measures, and the concordance correlation coefficient was shown to be the most restrictive. On using simulated data sets of a more realistic size, it was found that CCC was broadly in agreement, about 96% of the time, with other validation measures in accepting models as predictive, and in almost all the examples it was the most precautionary. The proposed concordance correlation coefficient also works well on real data sets, where it seems to be more stable, and helps in making decisions when the validation measures are in conflict. Since it is conceptually simple, and given its stability and restrictiveness, we propose the concordance correlation coefficient as a complementary, or alternative, more prudent measure of a QSAR model to be externally predictive.

External validation of the ability of the DRAGON score to predict outcome after thrombolysis treatment.

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Ovesen, C; Christensen, A; Nielsen, J K; Christensen, H

2013-11-01

Easy-to-perform and valid assessment scales for the effect of thrombolysis are essential in hyperacute stroke settings. Because of this we performed an external validation of the DRAGON scale proposed by Strbian et al. in a Danish cohort. All patients treated with intravenous recombinant plasminogen activator between 2009 and 2011 were included. Upon admission all patients underwent physical and neurological examination using the National Institutes of Health Stroke Scale along with non-contrast CT scans and CT angiography. Patients were followed up through the Outpatient Clinic and their modified Rankin Scale (mRS) was assessed after 3 months. Three hundred and three patients were included in the analysis. The DRAGON scale proved to have a good discriminative ability for predicting highly unfavourable outcome (mRS 5-6) (area under the curve-receiver operating characteristic [AUC-ROC]: 0.89; 95% confidence interval [CI] 0.81-0.96; pDRAGON scale provided good discriminative capability (AUC-ROC: 0.89; 95% CI 0.78-1.0; p=0.003) for highly unfavourable outcome. We confirmed the validity of the DRAGON scale in predicting outcome after thrombolysis treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Can endocranial volume be estimated accurately from external skull measurements in great-tailed grackles (Quiscalus mexicanus?

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Corina J. Logan

2015-06-01

Full Text Available There is an increasing need to validate and collect data approximating brain size on individuals in the field to understand what evolutionary factors drive brain size variation within and across species. We investigated whether we could accurately estimate endocranial volume (a proxy for brain size, as measured by computerized tomography (CT scans, using external skull measurements and/or by filling skulls with beads and pouring them out into a graduated cylinder for male and female great-tailed grackles. We found that while females had higher correlations than males, estimations of endocranial volume from external skull measurements or beads did not tightly correlate with CT volumes. We found no accuracy in the ability of external skull measures to predict CT volumes because the prediction intervals for most data points overlapped extensively. We conclude that we are unable to detect individual differences in endocranial volume using external skull measurements. These results emphasize the importance of validating and explicitly quantifying the predictive accuracy of brain size proxies for each species and each sex.

Predicting the 6-month risk of severe hypoglycemia among adults with diabetes: Development and external validation of a prediction model.

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Schroeder, Emily B; Xu, Stan; Goodrich, Glenn K; Nichols, Gregory A; O'Connor, Patrick J; Steiner, John F

2017-07-01

To develop and externally validate a prediction model for the 6-month risk of a severe hypoglycemic event among individuals with pharmacologically treated diabetes. The development cohort consisted of 31,674 Kaiser Permanente Colorado members with pharmacologically treated diabetes (2007-2015). The validation cohorts consisted of 38,764 Kaiser Permanente Northwest members and 12,035 HealthPartners members. Variables were chosen that would be available in electronic health records. We developed 16-variable and 6-variable models, using a Cox counting model process that allows for the inclusion of multiple 6-month observation periods per person. Across the three cohorts, there were 850,992 6-month observation periods, and 10,448 periods with at least one severe hypoglycemic event. The six-variable model contained age, diabetes type, HgbA1c, eGFR, history of a hypoglycemic event in the prior year, and insulin use. Both prediction models performed well, with good calibration and c-statistics of 0.84 and 0.81 for the 16-variable and 6-variable models, respectively. In the external validation cohorts, the c-statistics were 0.80-0.84. We developed and validated two prediction models for predicting the 6-month risk of hypoglycemia. The 16-variable model had slightly better performance than the 6-variable model, but in some practice settings, use of the simpler model may be preferred. Copyright © 2017 Elsevier Inc. All rights reserved.

External validation of a PCA-3-based nomogram for predicting prostate cancer and high-grade cancer on initial prostate biopsy.

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Greene, Daniel J; Elshafei, Ahmed; Nyame, Yaw A; Kara, Onder; Malkoc, Ercan; Gao, Tianming; Jones, J Stephen

2016-08-01

The aim of this study was to externally validate a previously developed PCA3-based nomogram for the prediction of prostate cancer (PCa) and high-grade (intermediate and/or high-grade) prostate cancer (HGPCa) at the time of initial prostate biopsy. A retrospective review was performed on a cohort of 336 men from a large urban academic medical center. All men had serum PSA PCa, PSA at diagnosis, PCA3, total prostate volume (TPV), and abnormal finding on digital rectal exam (DRE). These variables were used to test the accuracy (concordance index) and calibration of a previously published PCA3 nomogram. Biopsy confirms PCa and HGPCa in 51.0% and 30.4% of validation patients, respectively. This differed from the original cohort in that it had significantly more PCa and HGPCA (51% vs. 44%, P = 0.019; and 30.4% vs. 19.1%, P PCa detection the concordance index was 75% and 77% for overall PCa and HGPCa, respectively. Calibration for overall PCa was good. This represents the first external validation of a PCA3-based prostate cancer predictive nomogram in a North American population. Prostate 76:1019-1023, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Assessment of generalizability, applicability and predictability (GAP) for evaluating external validity in studies of universal family-based prevention of alcohol misuse in young people: systematic methodological review of randomized controlled trials.

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Fernandez-Hermida, Jose Ramon; Calafat, Amador; Becoña, Elisardo; Tsertsvadze, Alexander; Foxcroft, David R

2012-09-01

To assess external validity characteristics of studies from two Cochrane Systematic Reviews of the effectiveness of universal family-based prevention of alcohol misuse in young people. Two reviewers used an a priori developed external validity rating form and independently assessed three external validity dimensions of generalizability, applicability and predictability (GAP) in randomized controlled trials. The majority (69%) of the included 29 studies were rated 'unclear' on the reporting of sufficient information for judging generalizability from sample to study population. Ten studies (35%) were rated 'unclear' on the reporting of sufficient information for judging applicability to other populations and settings. No study provided an assessment of the validity of the trial end-point measures for subsequent mortality, morbidity, quality of life or other economic or social outcomes. Similarly, no study reported on the validity of surrogate measures using established criteria for assessing surrogate end-points. Studies evaluating the benefits of family-based prevention of alcohol misuse in young people are generally inadequate at reporting information relevant to generalizability of the findings or implications for health or social outcomes. Researchers, study authors, peer reviewers, journal editors and scientific societies should take steps to improve the reporting of information relevant to external validity in prevention trials. © 2012 The Authors. Addiction © 2012 Society for the Study of Addiction.

Process evaluation to explore internal and external validity of the "Act in Case of Depression" care program in nursing homes.

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Leontjevas, Ruslan; Gerritsen, Debby L; Koopmans, Raymond T C M; Smalbrugge, Martin; Vernooij-Dassen, Myrra J F J

2012-06-01

A multidisciplinary, evidence-based care program to improve the management of depression in nursing home residents was implemented and tested using a stepped-wedge design in 23 nursing homes (NHs): "Act in case of Depression" (AiD). Before effect analyses, to evaluate AiD process data on sampling quality (recruitment and randomization, reach) and intervention quality (relevance and feasibility, extent to which AiD was performed), which can be used for understanding internal and external validity. In this article, a model is presented that divides process evaluation data into first- and second-order process data. Qualitative and quantitative data based on personal files of residents, interviews of nursing home professionals, and a research database were analyzed according to the following process evaluation components: sampling quality and intervention quality. Nursing home. The pattern of residents' informed consent rates differed for dementia special care units and somatic units during the study. The nursing home staff was satisfied with the AiD program and reported that the program was feasible and relevant. With the exception of the first screening step (nursing staff members using a short observer-based depression scale), AiD components were not performed fully by NH staff as prescribed in the AiD protocol. Although NH staff found the program relevant and feasible and was satisfied with the program content, individual AiD components may have different feasibility. The results on sampling quality implied that statistical analyses of AiD effectiveness should account for the type of unit, whereas the findings on intervention quality implied that, next to the type of unit, analyses should account for the extent to which individual AiD program components were performed. In general, our first-order process data evaluation confirmed internal and external validity of the AiD trial, and this evaluation enabled further statistical fine tuning. The importance of

Validation of a Video-based Game-Understanding Test Procedure in Badminton.

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Blomqvist, Minna T.; Luhtanen, Pekka; Laakso, Lauri; Keskinen, Esko

2000-01-01

Reports the development and validation of video-based game-understanding tests in badminton for elementary and secondary students. The tests included different sequences that simulated actual game situations. Players had to solve tactical problems by selecting appropriate solutions and arguments for their decisions. Results suggest that the test…

External validation of two prediction models identifying employees at risk of high sickness absence : cohort study with 1-year follow-up

NARCIS (Netherlands)

Roelen, Corne A. M.; Bultmann, Ute; van Rhenen, Willem; van der Klink, Jac J. L.; Twisk, Jos W. R.; Heymans, Martijn W.

2013-01-01

Background: Two models including age, self-rated health (SRH) and prior sickness absence (SA) were found to predict high SA in health care workers. The present study externally validated these prediction models in a population of office workers and investigated the effect of adding gender as a

Development of Decision Support Formulas for the Prediction of Bladder Outlet Obstruction and Prostatic Surgery in Patients With Lower Urinary Tract Symptom/Benign Prostatic Hyperplasia: Part II, External Validation and Usability Testing of a Smartphone App

Directory of Open Access Journals (Sweden)

Min Soo Choo

2017-04-01

Full Text Available Purpose We aimed to externally validate the prediction model we developed for having bladder outlet obstruction (BOO and requiring prostatic surgery using 2 independent data sets from tertiary referral centers, and also aimed to validate a mobile app for using this model through usability testing. Methods Formulas and nomograms predicting whether a subject has BOO and needs prostatic surgery were validated with an external validation cohort from Seoul National University Bundang Hospital and Seoul Metropolitan Government-Seoul National University Boramae Medical Center between January 2004 and April 2015. A smartphone-based app was developed, and 8 young urologists were enrolled for usability testing to identify any human factor issues of the app. Results A total of 642 patients were included in the external validation cohort. No significant differences were found in the baseline characteristics of major parameters between the original (n=1,179 and the external validation cohort, except for the maximal flow rate. Predictions of requiring prostatic surgery in the validation cohort showed a sensitivity of 80.6%, a specificity of 73.2%, a positive predictive value of 49.7%, and a negative predictive value of 92.0%, and area under receiver operating curve of 0.84. The calibration plot indicated that the predictions have good correspondence. The decision curve showed also a high net benefit. Similar evaluation results using the external validation cohort were seen in the predictions of having BOO. Overall results of the usability test demonstrated that the app was user-friendly with no major human factor issues. Conclusions External validation of these newly developed a prediction model demonstrated a moderate level of discrimination, adequate calibration, and high net benefit gains for predicting both having BOO and requiring prostatic surgery. Also a smartphone app implementing the prediction model was user-friendly with no major human factor issue.

Development and validation of a system of assimilation indices: A mixed method approach to understand change in psychotherapy.

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Neto, David D; Baptista, Telmo M; Dent-Brown, Kim

2015-06-01

Assimilation is an important process in understanding change in psychotherapy. Similar to other psychological processes, assimilation may be traceable in the speech of clients by attending to its signs or indices. In the present research, we aimed to build a system of indices of assimilation. This research follows a mixed method design. The indices were derived through qualitative analysis, using grounded theory. Subsequently, the indices were adjusted quantitatively and applied to 30 single psychotherapy sessions of adult clients with depression and 11 therapists. Forty-two indices were found and grouped into the following five process categories of assimilation: external distress, pain, noticing, decentring and action. The indices showed good inter-rater reliability and internal consistency. Except for noticing, all process categories correlated significantly with each other according to conceptual proximity. The system of indices also showed convergent validity with an existing coding system of assimilation for two process categories. The results suggest that the system of indices is a useful approach for understanding assimilation. The consideration of assimilation in a continuous fashion through sub-processes may help to extend our knowledge of this process and provide a tool for clinical practice. Assimilation is an important process in understanding change in psychotherapy in the sense that it takes into account insight and action-related processes. Clients convey in their speech signs or indices of the assimilation process which can be observed both in the style and content of their utterances. Using these indices, therapists can continuously assess assimilation and use this information in choosing interventions. Limitations: This study follows a cross-sectional design and does not allow consideration of the predictive value of the indices. The outcome of the therapy was not taken into account, which restricts validity considerations to the comparison with

External validation of a decision tree early warning score using only laboratory data

DEFF Research Database (Denmark)

Holm Atkins, Tara E; Öhman, Malin C; Brabrand, Mikkel

2018-01-01

INTRODUCTION: Early warning scores (EWS) have been developed to identify the degree of illness severity among acutely ill patients. One system, The Laboratory Decision Tree Early Warning Score (LDT-EWS) is wholly laboratory data based. Laboratory data was used in the development of a rare...... computerized method, developing a decision tree analysis. This article externally validates LDT-EWS, which is obligatory for an EWS before clinical use. METHOD: We conducted a retrospective review of prospectively collected data based on a time limited sample of all patients admitted through the medical......) and calibration (precision) as Hosmer-Lemeshow Goodness of fit test. RESULTS: A total of 5858 patients were admitted and 4902 included (83.7%). In-hospital mortality in our final dataset (n=4902) was 3.5%. Discriminatory power (95% CI), identifying in-hospital death was 0.809 (0.777-0.842). Calibration was good...

External validation of the endometriosis fertility index (EFI) staging system for predicting non-ART pregnancy after endometriosis surgery.

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Tomassetti, C; Geysenbergh, B; Meuleman, C; Timmerman, D; Fieuws, S; D'Hooghe, T

2013-05-01

Can the ability of the endometriosis fertility index (EFI) to predict non-assisted reproductive technology (ART) pregnancy after endometriosis surgery be confirmed by an external validation study? The significant relationship between the EFI score and the time to non-ART pregnancy observed in our study represents an external validation of this scoring system. The EFI was previously developed and tested prospectively in a single center, but up to now no external validation has been published. Our data provide validation of the EFI in an external fertility unit on a robust scientific basis, to identify couples with a good prognosis for spontaneous conception who can therefore defer ART treatment, regardless of their revised American Fertility Society (rAFS) endometriosis staging. Retrospective cohort study where the EFI was calculated based on history and detailed surgical findings, and related to pregnancy outcome in 233 women attempting non-ART conception immediately after surgery; all data used for EFI calculation and analysis of reproductive outcome had been collected prospectively as part of another study. The EFI score was calculated (score 0-10) for 233 women with all rAFS endometriosis stages (minimal-mild, n = 75; moderate-severe, n = 158) after endometriosis surgery (1 September 2006-30 September 2010) in a university hospital-based reproductive medicine unit with combined expertise in reproductive surgery and medically assisted reproduction. All participants attempted non-ART conception immediately after surgery by natural intercourse, ovulation induction with timed intercourse or intrauterine insemination (with or without ovulation induction or controlled ovarian stimulation). All analyses were performed for three different definitions of pregnancy [overall (any HCG >25 IU/l), clinical and ongoing >20 weeks]. Six groups were distinguished (EFI scores 1-3, 4, 5, 6, 7+8, 9+10), and Kaplan-Meier (K-M) estimates for cumulative pregnancy rate were calculated

Towards a better understanding of helicopter external noise

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Damongeot, A.; Dambra, F.; Masure, B.

The problem of helicopter external noise generation is studied taking into consideration simultaneously the multiple noise sources: rotor rotational-, rotor broadband -, and engine noise. The main data are obtained during flight tests of the rather quiet AS 332 Super Puma. The flight procedures settled by ICAO for noise regulations are used: horizontal flyover at 90 percent of the maximum speed, approach at minimum power velocity, take-off at best rate of climb. Noise source levels are assessed through narrow band analysis of ground microphone recordings, ground measurements of engine noise and theoretical means. With the perceived noise level unit used throughout the study, relative magnitude of noise sources is shown to be different from that obtained with linear noise unit. A parametric study of the influence of some helicopter parameters on external noise has shown that thickness-tapered, chord-tapered, and swept-back blade tips are good means to reduce the overall noise level in flyover and approach.

Validation of the prognostic gene portfolio, ClinicoMolecular Triad Classification, using an independent prospective breast cancer cohort and external patient populations

Science.gov (United States)

2014-01-01

Introduction Using genome-wide expression profiles of a prospective training cohort of breast cancer patients, ClinicoMolecular Triad Classification (CMTC) was recently developed to classify breast cancers into three clinically relevant groups to aid treatment decisions. CMTC was found to be both prognostic and predictive in a large external breast cancer cohort in that study. This study serves to validate the reproducibility of CMTC and its prognostic value using independent patient cohorts. Methods An independent internal cohort (n = 284) and a new external cohort (n = 2,181) were used to validate the association of CMTC between clinicopathological factors, 12 known gene signatures, two molecular subtype classifiers, and 19 oncogenic signalling pathway activities, and to reproduce the abilities of CMTC to predict clinical outcomes of breast cancer. In addition, we also updated the outcome data of the original training cohort (n = 147). Results The original training cohort reached a statistically significant difference (p risk groups. Conclusions Both prospective internal cohorts and the independent external cohorts reproduced the triad classification of CMTC and its prognostic significance. CMTC is an independent prognostic predictor, and it outperformed 12 other known prognostic gene signatures, molecular subtype classifications, and all other standard prognostic clinicopathological factors. Our results support further development of CMTC portfolio into a guide for personalized breast cancer treatments. PMID:24996446

Clinical Validity, Understandability, and Actionability of Online Cardiovascular Disease Risk Calculators: Systematic Review.

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Bonner, Carissa; Fajardo, Michael Anthony; Hui, Samuel; Stubbs, Renee; Trevena, Lyndal

2018-02-01

Online health information is particularly important for cardiovascular disease (CVD) prevention, where lifestyle changes are recommended until risk becomes high enough to warrant pharmacological intervention. Online information is abundant, but the quality is often poor and many people do not have adequate health literacy to access, understand, and use it effectively. This project aimed to review and evaluate the suitability of online CVD risk calculators for use by low health literate consumers in terms of clinical validity, understandability, and actionability. This systematic review of public websites from August to November 2016 used evaluation of clinical validity based on a high-risk patient profile and assessment of understandability and actionability using Patient Education Material Evaluation Tool for Print Materials. A total of 67 unique webpages and 73 unique CVD risk calculators were identified. The same high-risk patient profile produced widely variable CVD risk estimates, ranging from as little as 3% to as high as a 43% risk of a CVD event over the next 10 years. One-quarter (25%) of risk calculators did not specify what model these estimates were based on. The most common clinical model was Framingham (44%), and most calculators (77%) provided a 10-year CVD risk estimate. The calculators scored moderately on understandability (mean score 64%) and poorly on actionability (mean score 19%). The absolute percentage risk was stated in most (but not all) calculators (79%), and only 18% included graphical formats consistent with recommended risk communication guidelines. There is a plethora of online CVD risk calculators available, but they are not readily understandable and their actionability is poor. Entering the same clinical information produces widely varying results with little explanation. Developers need to address actionability as well as clinical validity and understandability to improve usefulness to consumers with low health literacy. �

Predicting AKI in emergency admissions: an external validation study of the acute kidney injury prediction score (APS).

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Hodgson, L E; Dimitrov, B D; Roderick, P J; Venn, R; Forni, L G

2017-03-08

Hospital-acquired acute kidney injury (HA-AKI) is associated with a high risk of mortality. Prediction models or rules may identify those most at risk of HA-AKI. This study externally validated one of the few clinical prediction rules (CPRs) derived in a general medicine cohort using clinical information and data from an acute hospitals electronic system on admission: the acute kidney injury prediction score (APS). External validation in a single UK non-specialist acute hospital (2013-2015, 12 554 episodes); four cohorts: adult medical and general surgical populations, with and without a known preadmission baseline serum creatinine (SCr). Performance assessed by discrimination using area under the receiver operating characteristic curves (AUCROC) and calibration. HA-AKI incidence within 7 days (kidney disease: improving global outcomes (KDIGO) change in SCr) was 8.1% (n=409) of medical patients with known baseline SCr, 6.6% (n=141) in those without a baseline, 4.9% (n=204) in surgical patients with baseline and 4% (n=49) in those without. Across the four cohorts AUCROC were: medical with known baseline 0.65 (95% CIs 0.62 to 0.67) and no baseline 0.71 (0.67 to 0.75), surgical with baseline 0.66 (0.62 to 0.70) and no baseline 0.68 (0.58 to 0.75). For calibration, in medicine and surgical cohorts with baseline SCr, Hosmer-Lemeshow p values were non-significant, suggesting acceptable calibration. In the medical cohort, at a cut-off of five points on the APS to predict HA-AKI, positive predictive value was 16% (13-18%) and negative predictive value 94% (93-94%). Of medical patients with HA-AKI, those with an APS ≥5 had a significantly increased risk of death (28% vs 18%, OR 1.8 (95% CI 1.1 to 2.9), p=0.015). On external validation the APS on admission shows moderate discrimination and acceptable calibration to predict HA-AKI and may be useful as a severity marker when HA-AKI occurs. Harnessing linked data from primary care may be one way to achieve more accurate

Development and external multicenter validation of Chinese Prostate Cancer Consortium prostate cancer risk calculator for initial prostate biopsy.

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Chen, Rui; Xie, Liping; Xue, Wei; Ye, Zhangqun; Ma, Lulin; Gao, Xu; Ren, Shancheng; Wang, Fubo; Zhao, Lin; Xu, Chuanliang; Sun, Yinghao

2016-09-01

Substantial differences exist in the relationship of prostate cancer (PCa) detection rate and prostate-specific antigen (PSA) level between Western and Asian populations. Classic Western risk calculators, European Randomized Study for Screening of Prostate Cancer Risk Calculator, and Prostate Cancer Prevention Trial Risk Calculator, were shown to be not applicable in Asian populations. We aimed to develop and validate a risk calculator for predicting the probability of PCa and high-grade PCa (defined as Gleason Score sum 7 or higher) at initial prostate biopsy in Chinese men. Urology outpatients who underwent initial prostate biopsy according to the inclusion criteria were included. The multivariate logistic regression-based Chinese Prostate Cancer Consortium Risk Calculator (CPCC-RC) was constructed with cases from 2 hospitals in Shanghai. Discriminative ability, calibration and decision curve analysis were externally validated in 3 CPCC member hospitals. Of the 1,835 patients involved, PCa was identified in 338/924 (36.6%) and 294/911 (32.3%) men in the development and validation cohort, respectively. Multivariate logistic regression analyses showed that 5 predictors (age, logPSA, logPV, free PSA ratio, and digital rectal examination) were associated with PCa (Model 1) or high-grade PCa (Model 2), respectively. The area under the curve of Model 1 and Model 2 was 0.801 (95% CI: 0.771-0.831) and 0.826 (95% CI: 0.796-0.857), respectively. Both models illustrated good calibration and substantial improvement in decision curve analyses than any single predictors at all threshold probabilities. Higher predicting accuracy, better calibration, and greater clinical benefit were achieved by CPCC-RC, compared with European Randomized Study for Screening of Prostate Cancer Risk Calculator and Prostate Cancer Prevention Trial Risk Calculator in predicting PCa. CPCC-RC performed well in discrimination and calibration and decision curve analysis in external validation compared

EXTERNAL VALIDATION OF THE DIABETES EARLY READMISSION RISK INDICATOR (DERRI™).

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Rubin, Daniel J; Recco, Dominic; Turchin, Alexander; Zhao, Huaqing; Golden, Sherita Hill

2018-04-06

The Diabetes Early Readmission Risk Indicator (DERRI ™ ) was previously developed and internally validated as a tool to predict the risk of all-cause readmission within 30 days of discharge (30-d readmission) of hospitalized patients with diabetes. In this study, the predictive performance of the DERRI ™ with and without additional predictors was assessed in an external sample. We conducted a retrospective cohort study of adult patients with diabetes discharged from 2 academic medical centers between 1/1/2000 and 12/31/2014. We applied the previously developed DERRI ™ , which includes admission laboratory results, sociodemographics, a diagnosis of certain comorbidities, and recent discharge information, and evaluated the effect of adding metabolic indicators on predictive performance using multivariable logistic regression. Total cholesterol and A1c were selected based on clinical relevance and univariate association with 30-d readmission. Among 105,974 discharges, 19,032 (18.0%) were followed by 30-d readmission for any cause. The DERRI ™ had a C-statistic of 0.634 for 30-d readmission. Total cholesterol (TC) was the lipid parameter most strongly associated with 30-d readmission. The DERRI ™ predictors, A1c, and TC were significantly associated with 30-d readmission; however, their addition to the DERRI ™ did not significantly change model performance (C-statistic 0.643 [95% CI, 0.638-0.647], p=0.92). Performance of the DERRI ™ in this external cohort was modest but comparable to other readmission prediction models. Addition of A1c and TC to the DERRI ™ did not significantly improve performance. Although the DERRI ™ may be useful to direct resources toward diabetes patients at higher risk, better prediction is needed. DERRI = Diabetes Early Readmission Risk Indicator; TC = Total cholesterol; A1c = hemoglobin A1c; HDL-C = high-density lipoprotein cholesterol; LDL-C = low-density lipoprotein cholesterol; DKA = diabetic ketoacidosis; HHS

Prevalence of diabetes treatment effect modifiers: the external validity of trials to older adults.

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Weiss, Carlos O; Boyd, Cynthia M; Wolff, Jennifer L; Leff, Bruce

2012-08-01

Potential treatment effect modifiers (TEMs) are specific diseases or conditions with a well-described mechanism for treatment effect modification. The prevalence of TEMs in older adults with type 2 diabetes mellitus (DM) is unknown. Objectives were to 1) determine the prevalence of pre-specified potential TEMs; 2) demonstrate the potential impact of TEMs in the older adult population using a simulated trial; 3) identify TEM combinations associated with number of hospitalizations to test construct validity. Data are from the nationally-representative United States National Health and Examination Survey, 1999-2004: 8646 Civilian, non-institutionalized adults aged 45-64 or 65+ years, including 1443 with DM. TEMs were anemia, congestive heart failure, liver inflammation, polypharmacy, renal insufficiency, cognitive impairment, dizziness, frequent mental distress, mobility difficulty, and visual impairment. A trial was simulated to examine prevalence of potential TEM impact. The cross-sectional association between TEM patterns and number of hospitalizations was estimated to assess construct validity. The prevalence of TEMs was substantial such that 19.0% (95% CI 14.8-23.2) of middle-aged adults and 38.0% (95% CI 33.4-42.5) of older adults had any two. A simulated trial with modest levels of interaction suggested the prevalence of TEMs could nullify treatment benefit in 3.9-27.2% of older adults with DM. Compared to having DM alone, hospitalization rate was increased by several combinations of TEMs with substantial prevalence. We provide national benchmarks that can be used to evaluate TEM prevalence reported by clinical trials of DM, and correspondingly their external validity to older adults.

Predictive Accuracy of the PanCan Lung Cancer Risk Prediction Model -External Validation based on CT from the Danish Lung Cancer Screening Trial

NARCIS (Netherlands)

Wille, M.M.W.; Riel, S.J. van; Saghir, Z.; Dirksen, A.; Pedersen, J.H.; Jacobs, C.; Thomsen, L.H.u.; Scholten, E.T.; Skovgaard, L.T.; Ginneken, B. van

2015-01-01

Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models.From the DLCST database, 1,152

Development and external validation of a clinical prognostic score for death in visceral leishmaniasis patients in a high HIV co-infection burden area in Ethiopia.

Directory of Open Access Journals (Sweden)

Charles Abongomera

Full Text Available In Ethiopia, case fatality rates among subgroups of visceral leishmaniasis (VL patients are high. A clinical prognostic score for death in VL patients could contribute to optimal management and reduction of these case fatality rates. We aimed to identify predictors of death from VL, and to develop and externally validate a clinical prognostic score for death in VL patients, in a high HIV co-infection burden area in Ethiopia.We conducted a retrospective cohort study in north west Ethiopia. Predictors with an adjusted likelihood ratio ≥1.5 or ≤0.67 were retained to calculate the predictor score. The derivation cohort consisted of 1686 VL patients treated at an upgraded health center and the external validation cohort consisted of 404 VL patients treated in hospital. There were 99 deaths in the derivation cohort and 53 deaths in the external validation cohort. The predictors of death were: age >40 years (score +1; HIV seropositive (score +1; HIV seronegative (score -1; hemoglobin ≤6.5 g/dl (score +1; bleeding (score +1; jaundice (score +1; edema (score +1; ascites (score +2 and tuberculosis (score +1. The total predictor score per patient ranged from -1 to +5. A score of -1, indicated a low risk of death (1.0%, a score of 0 an intermediate risk of death (3.8% and a score of +1 to +5, a high risk of death (10.4-85.7%. The area under the receiver operating characteristic curve was 0.83 (95% confidence interval: 0.79-0.87 in derivation, and 0.78 (95% confidence interval: 0.72-0.83 in external validation.The overall performance of the score was good. The score can enable the early detection of VL cases at high risk of death, which can inform operational, clinical management guidelines, and VL program management. Implementation of focused strategies could contribute to optimal management and reduction of the case fatality rates.

Evaluating the predictive accuracy and the clinical benefit of a nomogram aimed to predict survival in node-positive prostate cancer patients: External validation on a multi-institutional database.

Science.gov (United States)

Bianchi, Lorenzo; Schiavina, Riccardo; Borghesi, Marco; Bianchi, Federico Mineo; Briganti, Alberto; Carini, Marco; Terrone, Carlo; Mottrie, Alex; Gacci, Mauro; Gontero, Paolo; Imbimbo, Ciro; Marchioro, Giansilvio; Milanese, Giulio; Mirone, Vincenzo; Montorsi, Francesco; Morgia, Giuseppe; Novara, Giacomo; Porreca, Angelo; Volpe, Alessandro; Brunocilla, Eugenio

2018-04-06

To assess the predictive accuracy and the clinical value of a recent nomogram predicting cancer-specific mortality-free survival after surgery in pN1 prostate cancer patients through an external validation. We evaluated 518 prostate cancer patients treated with radical prostatectomy and pelvic lymph node dissection with evidence of nodal metastases at final pathology, at 10 tertiary centers. External validation was carried out using regression coefficients of the previously published nomogram. The performance characteristics of the model were assessed by quantifying predictive accuracy, according to the area under the curve in the receiver operating characteristic curve and model calibration. Furthermore, we systematically analyzed the specificity, sensitivity, positive predictive value and negative predictive value for each nomogram-derived probability cut-off. Finally, we implemented decision curve analysis, in order to quantify the nomogram's clinical value in routine practice. External validation showed inferior predictive accuracy as referred to in the internal validation (65.8% vs 83.3%, respectively). The discrimination (area under the curve) of the multivariable model was 66.7% (95% CI 60.1-73.0%) by testing with receiver operating characteristic curve analysis. The calibration plot showed an overestimation throughout the range of predicted cancer-specific mortality-free survival rates probabilities. However, in decision curve analysis, the nomogram's use showed a net benefit when compared with the scenarios of treating all patients or none. In an external setting, the nomogram showed inferior predictive accuracy and suboptimal calibration characteristics as compared to that reported in the original population. However, decision curve analysis showed a clinical net benefit, suggesting a clinical implication to correctly manage pN1 prostate cancer patients after surgery. © 2018 The Japanese Urological Association.

Development, external validation and clinical usefulness of a practical prediction model for radiation-induced dysphagia in lung cancer patients

International Nuclear Information System (INIS)

Dehing-Oberije, Cary; De Ruysscher, Dirk; Petit, Steven; Van Meerbeeck, Jan; Vandecasteele, Katrien; De Neve, Wilfried; Dingemans, Anne Marie C.; El Naqa, Issam; Deasy, Joseph; Bradley, Jeff; Huang, Ellen; Lambin, Philippe

2010-01-01

Introduction: Acute dysphagia is a distressing dose-limiting toxicity occurring frequently during concurrent chemo-radiation or high-dose radiotherapy for lung cancer. It can lead to treatment interruptions and thus jeopardize survival. Although a number of predictive factors have been identified, it is still not clear how these could offer assistance for treatment decision making in daily clinical practice. Therefore, we have developed and validated a nomogram to predict this side-effect. In addition, clinical usefulness was assessed by comparing model predictions to physicians' predictions. Materials and methods: Clinical data from 469 inoperable lung cancer patients, treated with curative intent, were collected prospectively. A prediction model for acute radiation-induced dysphagia was developed. Model performance was evaluated by the c-statistic and assessed using bootstrapping as well as two external datasets. In addition, a prospective study was conducted comparing model to physicians' predictions in 138 patients. Results: The final multivariate model consisted of age, gender, WHO performance status, mean esophageal dose (MED), maximum esophageal dose (MAXED) and overall treatment time (OTT). The c-statistic, assessed by bootstrapping, was 0.77. External validation yielded an AUC of 0.94 on the Ghent data and 0.77 on the Washington University St. Louis data for dysphagia ≥ grade 3. Comparing model predictions to the physicians' predictions resulted in an AUC of 0.75 versus 0.53, respectively. Conclusions: The proposed model performed well was successfully validated and demonstrated the ability to predict acute severe dysphagia remarkably better than the physicians. Therefore, this model could be used in clinical practice to identify patients at high or low risk.

External Validation of a Case-Mix Adjustment Model for the Standardized Reporting of 30-Day Stroke Mortality Rates in China.

Science.gov (United States)

Yu, Ping; Pan, Yuesong; Wang, Yongjun; Wang, Xianwei; Liu, Liping; Ji, Ruijun; Meng, Xia; Jing, Jing; Tong, Xu; Guo, Li; Wang, Yilong

2016-01-01

A case-mix adjustment model has been developed and externally validated, demonstrating promise. However, the model has not been thoroughly tested among populations in China. In our study, we evaluated the performance of the model in Chinese patients with acute stroke. The case-mix adjustment model A includes items on age, presence of atrial fibrillation on admission, National Institutes of Health Stroke Severity Scale (NIHSS) score on admission, and stroke type. Model B is similar to Model A but includes only the consciousness component of the NIHSS score. Both model A and B were evaluated to predict 30-day mortality rates in 13,948 patients with acute stroke from the China National Stroke Registry. The discrimination of the models was quantified by c-statistic. Calibration was assessed using Pearson's correlation coefficient. The c-statistic of model A in our external validation cohort was 0.80 (95% confidence interval, 0.79-0.82), and the c-statistic of model B was 0.82 (95% confidence interval, 0.81-0.84). Excellent calibration was reported in the two models with Pearson's correlation coefficient (0.892 for model A, pcase-mix adjustment model could be used to effectively predict 30-day mortality rates in Chinese patients with acute stroke.

Validation of psychoanalytic theories: towards a conceptualization of references.

Science.gov (United States)

Zachrisson, Anders; Zachrisson, Henrik Daae

2005-10-01

The authors discuss criteria for the validation of psychoanalytic theories and develop a heuristic and normative model of the references needed for this. Their core question in this paper is: can psychoanalytic theories be validated exclusively from within psychoanalytic theory (internal validation), or are references to sources of knowledge other than psychoanalysis also necessary (external validation)? They discuss aspects of the classic truth criteria correspondence and coherence, both from the point of view of contemporary psychoanalysis and of contemporary philosophy of science. The authors present arguments for both external and internal validation. Internal validation has to deal with the problems of subjectivity of observations and circularity of reasoning, external validation with the problem of relevance. They recommend a critical attitude towards psychoanalytic theories, which, by carefully scrutinizing weak points and invalidating observations in the theories, reduces the risk of wishful thinking. The authors conclude by sketching a heuristic model of validation. This model combines correspondence and coherence with internal and external validation into a four-leaf model for references for the process of validating psychoanalytic theories.

Prediction models for successful external cephalic version: a systematic review.

Science.gov (United States)

Velzel, Joost; de Hundt, Marcella; Mulder, Frederique M; Molkenboer, Jan F M; Van der Post, Joris A M; Mol, Ben W; Kok, Marjolein

2015-12-01

To provide an overview of existing prediction models for successful ECV, and to assess their quality, development and performance. We searched MEDLINE, EMBASE and the Cochrane Library to identify all articles reporting on prediction models for successful ECV published from inception to January 2015. We extracted information on study design, sample size, model-building strategies and validation. We evaluated the phases of model development and summarized their performance in terms of discrimination, calibration and clinical usefulness. We collected different predictor variables together with their defined significance, in order to identify important predictor variables for successful ECV. We identified eight articles reporting on seven prediction models. All models were subjected to internal validation. Only one model was also validated in an external cohort. Two prediction models had a low overall risk of bias, of which only one showed promising predictive performance at internal validation. This model also completed the phase of external validation. For none of the models their impact on clinical practice was evaluated. The most important predictor variables for successful ECV described in the selected articles were parity, placental location, breech engagement and the fetal head being palpable. One model was assessed using discrimination and calibration using internal (AUC 0.71) and external validation (AUC 0.64), while two other models were assessed with discrimination and calibration, respectively. We found one prediction model for breech presentation that was validated in an external cohort and had acceptable predictive performance. This model should be used to council women considering ECV. Copyright © 2015. Published by Elsevier Ireland Ltd.

Development and validation of a computational model to study the effect of foot constraint on ankle injury due to external rotation.

Science.gov (United States)

Wei, Feng; Hunley, Stanley C; Powell, John W; Haut, Roger C

2011-02-01

Recent studies, using two different manners of foot constraint, potted and taped, document altered failure characteristics in the human cadaver ankle under controlled external rotation of the foot. The posterior talofibular ligament (PTaFL) was commonly injured when the foot was constrained in potting material, while the frequency of deltoid ligament injury was higher for the taped foot. In this study an existing multibody computational modeling approach was validated to include the influence of foot constraint, determine the kinematics of the joint under external foot rotation, and consequently obtain strains in various ligaments. It was hypothesized that the location of ankle injury due to excessive levels of external foot rotation is a function of foot constraint. The results from this model simulation supported this hypothesis and helped to explain the mechanisms of injury in the cadaver experiments. An excessive external foot rotation might generate a PTaFL injury for a rigid foot constraint, and an anterior deltoid ligament injury for a pliant foot constraint. The computational models may be further developed and modified to simulate the human response for different shoe designs, as well as on various athletic shoe-surface interfaces, so as to provide a computational basis for optimizing athletic performance with minimal injury risk.

External validation of scoring systems in risk stratification of upper gastrointestinal bleeding.

Science.gov (United States)

Anchu, Anna Cherian; Mohsina, Subair; Sureshkumar, Sathasivam; Mahalakshmy, T; Kate, Vikram

2017-03-01

The aim of this study was to externally validate the four commonly used scoring systems in the risk stratification of patients with upper gastrointestinal bleed (UGIB). Patients of UGIB who underwent endoscopy within 24 h of presentation were stratified prospectively using the pre-endoscopy Rockall score (PRS) >0, complete Rockall score (CRS) >2, Glasgow Blatchford bleeding scores (GBS) >3, and modified GBS (m-GBS) >3 scores. Patients were followed up to 30 days. Prognostic accuracy of the scores was done by comparing areas under curve (AUC) in terms of overall risk stratification, re-bleeding, mortality, need for intervention, and length of hospitalization. One hundred and seventy-five patients were studied. All four scores performed better in the overall risk stratification on AUC [PRS = 0.566 (CI: 0.481-0.651; p-0.043)/CRS = 0.712 (CI: 0.634-0.790); p0.001); m-GBS = 0.802 (CI: 0.734-0.871; pbleed [AUC-0.679 (CI: 0.579-0.780; p = 0.003)]. All the scoring systems except PRS were found to be significantly better in detecting 30-day mortality with a high AUC (CRS = 0.798; p-0.042)/GBS = 0.833; p-0.023); m-GBS = 0.816; p-0.031). All four scores demonstrated significant accuracy in the risk stratification of non-variceal patients; however, only GBS and m-GBS were significant in variceal etiology. Higher cutoff scores achieved better sensitivity/specificity [RS > 0 (50/60.8), CRS > 1 (87.5/50.6), GBS > 7 (88.5/63.3), m-GBS > 7(82.3/72.6)] in the risk stratification. GBS and m-GBS appear to be more valid in risk stratification of UGIB patients in this region. Higher cutoff values achieved better predictive accuracy.

Understanding China's Transformations

DEFF Research Database (Denmark)

Li, Xing

The objective of this paper is to offer a framework of understanding the dialectical nexus between China's internal evolutions and the external influences with a focus on the century-long "challenge-response" dynamism. That is to explore how external factors helped shaping China's internal...... transformations, i.e. how generations of Chinese have been struggling in responding to the external challenges and attempting to sinicize external political ideas in order to change China from within. Likewise, it is equally important to understand how China's inner transformation contributed to reshaping...... the world. Each time, be it China's dominance or decline, the capitalist world system has to adjust and readjust itself to the opportunities and constraints brought about by the "China factors"....

Meaningful Understanding and Systems Thinking in Organic Chemistry: Validating Measurement and Exploring Relationships

Science.gov (United States)

Vachliotis, Theodoros; Salta, Katerina; Tzougraki, Chryssa

2014-01-01

The purpose of this study was dual: First, to develop and validate assessment schemes for assessing 11th grade students' meaningful understanding of organic chemistry concepts, as well as their systems thinking skills in the domain. Second, to explore the relationship between the two constructs of interest based on students' performance…

External validation and calibration of IVFpredict: a national prospective cohort study of 130,960 in vitro fertilisation cycles.

Directory of Open Access Journals (Sweden)

Andrew D A C Smith

Full Text Available Accurately predicting the probability of a live birth after in vitro fertilisation (IVF is important for patients, healthcare providers and policy makers. Two prediction models (Templeton and IVFpredict have been previously developed from UK data and are widely used internationally. The more recent of these, IVFpredict, was shown to have greater predictive power in the development dataset. The aim of this study was external validation of the two models and comparison of their predictive ability.130,960 IVF cycles undertaken in the UK in 2008-2010 were used to validate and compare the Templeton and IVFpredict models. Discriminatory power was calculated using the area under the receiver-operator curve and calibration assessed using a calibration plot and Hosmer-Lemeshow statistic. The scaled modified Brier score, with measures of reliability and resolution, were calculated to assess overall accuracy. Both models were compared after updating for current live birth rates to ensure that the average observed and predicted live birth rates were equal. The discriminative power of both methods was comparable: the area under the receiver-operator curve was 0.628 (95% confidence interval (CI: 0.625-0.631 for IVFpredict and 0.616 (95% CI: 0.613-0.620 for the Templeton model. IVFpredict had markedly better calibration and higher diagnostic accuracy, with calibration plot intercept of 0.040 (95% CI: 0.017-0.063 and slope of 0.932 (95% CI: 0.839-1.025 compared with 0.080 (95% CI: 0.044-0.117 and 1.419 (95% CI: 1.149-1.690 for the Templeton model. Both models underestimated the live birth rate, but this was particularly marked in the Templeton model. Updating the models to reflect improvements in live birth rates since the models were developed enhanced their performance, but IVFpredict remained superior.External validation in a large population cohort confirms IVFpredict has superior discrimination and calibration for informing patients, clinicians and

Development and External Validation of Prognostic Model for 2-Year Survival of Non-Small-Cell Lung Cancer Patients Treated With Chemoradiotherapy

International Nuclear Information System (INIS)

Dehing-Oberije, Cary; Yu Shipeng; De Ruysscher, Dirk; Meersschout, Sabine; Van Beek, Karen; Lievens, Yolande; Van Meerbeeck, Jan; De Neve, Wilfried; Rao, Bharat Ph.D.; Weide, Hiska van der; Lambin, Philippe

2009-01-01

Purpose: Radiotherapy, combined with chemotherapy, is the treatment of choice for a large group of non-small-cell lung cancer (NSCLC) patients. Recent developments in the treatment of these patients have led to improved survival. However, the clinical TNM stage is highly inaccurate for the prediction of survival, and alternatives are lacking. The objective of this study was to develop and validate a prediction model for survival of NSCLC patients, treated with chemoradiotherapy. Patients and Methods: The clinical data from 377 consecutive inoperable NSCLC patients, Stage I-IIIB, treated radically with chemoradiotherapy were collected. A prognostic model for 2-year survival was developed, using 2-norm support vector machines. The performance of the model was expressed as the area under the curve of the receiver operating characteristic and assessed using leave-one-out cross-validation, as well as two external data sets. Results: The final multivariate model consisted of gender, World Health Organization performance status, forced expiratory volume in 1 s, number of positive lymph node stations, and gross tumor volume. The area under the curve, assessed by leave-one-out cross-validation, was 0.74, and application of the model to the external data sets yielded an area under the curve of 0.75 and 0.76. A high- and low-risk group could be clearly identified using a risk score based on the model. Conclusion: The multivariate model performed very well and was able to accurately predict the 2-year survival of NSCLC patients treated with chemoradiotherapy. The model could support clinicians in the treatment decision-making process.

Model-based clinical dose optimization for phenobarbital in neonates: An illustration of the importance of data sharing and external validation.

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Völler, Swantje; Flint, Robert B; Stolk, Leo M; Degraeuwe, Pieter L J; Simons, Sinno H P; Pokorna, Paula; Burger, David M; de Groot, Ronald; Tibboel, Dick; Knibbe, Catherijne A J

2017-11-15

Particularly in the pediatric clinical pharmacology field, data-sharing offers the possibility of making the most of all available data. In this study, we utilize previously collected therapeutic drug monitoring (TDM) data of term and preterm newborns to develop a population pharmacokinetic model for phenobarbital. We externally validate the model using prospective phenobarbital data from an ongoing pharmacokinetic study in preterm neonates. TDM data from 53 neonates (gestational age (GA): 37 (24-42) weeks, bodyweight: 2.7 (0.45-4.5) kg; postnatal age (PNA): 4.5 (0-22) days) contained information on dosage histories, concentration and covariate data (including birth weight, actual weight, post-natal age (PNA), postmenstrual age, GA, sex, liver and kidney function, APGAR-score). Model development was carried out using NONMEM ® 7.3. After assessment of model fit, the model was validated using data of 17 neonates included in the DINO (Drug dosage Improvement in NeOnates)-study. Modelling of 229 plasma concentrations, ranging from 3.2 to 75.2mg/L, resulted in a one compartment model for phenobarbital. Clearance (CL) and volume (V d ) for a child with a birthweight of 2.6kg at PNA day 4.5 was 0.0091L/h (9%) and 2.38L (5%), respectively. Birthweight and PNA were the best predictors for CL maturation, increasing CL by 36.7% per kg birthweight and 5.3% per postnatal day of living, respectively. The best predictor for the increase in V d was actual bodyweight (0.31L/kg). External validation showed that the model can adequately predict the pharmacokinetics in a prospective study. Data-sharing can help to successfully develop and validate population pharmacokinetic models in neonates. From the results it seems that both PNA and bodyweight are required to guide dosing of phenobarbital in term and preterm neonates. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

External Validation of a Case-Mix Adjustment Model for the Standardized Reporting of 30-Day Stroke Mortality Rates in China.

Directory of Open Access Journals (Sweden)

Ping Yu

Full Text Available A case-mix adjustment model has been developed and externally validated, demonstrating promise. However, the model has not been thoroughly tested among populations in China. In our study, we evaluated the performance of the model in Chinese patients with acute stroke.The case-mix adjustment model A includes items on age, presence of atrial fibrillation on admission, National Institutes of Health Stroke Severity Scale (NIHSS score on admission, and stroke type. Model B is similar to Model A but includes only the consciousness component of the NIHSS score. Both model A and B were evaluated to predict 30-day mortality rates in 13,948 patients with acute stroke from the China National Stroke Registry. The discrimination of the models was quantified by c-statistic. Calibration was assessed using Pearson's correlation coefficient.The c-statistic of model A in our external validation cohort was 0.80 (95% confidence interval, 0.79-0.82, and the c-statistic of model B was 0.82 (95% confidence interval, 0.81-0.84. Excellent calibration was reported in the two models with Pearson's correlation coefficient (0.892 for model A, p<0.001; 0.927 for model B, p = 0.008.The case-mix adjustment model could be used to effectively predict 30-day mortality rates in Chinese patients with acute stroke.

Physical activity promotion in Latin American populations: a systematic review on issues of internal and external validity.

Science.gov (United States)

Galaviz, Karla I; Harden, Samantha M; Smith, Erin; Blackman, Kacie Ca; Berrey, Leanna M; Mama, Scherezade K; Almeida, Fabio A; Lee, Rebecca E; Estabrooks, Paul A

2014-06-17

The purpose of this review was to determine the degree to which physical activity interventions for Latin American populations reported on internal and external validity factors using the RE-AIM framework (reach & representativeness, effectiveness, adoption, implementation, maintenance). We systematically identified English (PubMed; EbscoHost) and Spanish (SCIELO; Biblioteca Virtual en Salud) language studies published between 2001 and 2012 that tested physical activity, exercise, or fitness promotion interventions in Latin American populations. Cross-sectional/descriptive studies, conducted in Brazil or Spain, published in Portuguese, not including a physical activity/fitness/exercise outcome, and with one time point assessment were excluded. We reviewed 192 abstracts and identified 46 studies that met the eligibility criteria (34 in English, 12 in Spanish). A validated 21-item RE-AIM abstraction tool was used to determine the quality of reporting across studies (0-7 = low, 8-14 = moderate, and 15-21 = high). The number of indicators reported ranged from 3-14 (mean = 8.1 ± 2.6), with the majority of studies falling in the moderate quality reporting category. English and Spanish language articles did not differ on the number of indicators reported (8.1 vs. 8.3, respectively). However, Spanish articles reported more across reach indicators (62% vs. 43% of indicators), while English articles reported more across effectiveness indicators (69% vs 62%). Across RE-AIM dimensions, indicators for reach (48%), efficacy/effectiveness (67%), and implementation (41%) were reported more often than indicators of adoption (25%) and maintenance (10%). Few studies reported on the representativeness of participants, staff that delivered interventions, or the settings where interventions were adopted. Only 13% of the studies reported on quality of life and/or potential negative outcomes, 20% reported on intervention fidelity, and 11% on cost of implementation

A general psychopathology factor (P factor) in children: Structural model analysis and external validation through familial risk and child global executive function.

Science.gov (United States)

Martel, Michelle M; Pan, Pedro M; Hoffmann, Maurício S; Gadelha, Ary; do Rosário, Maria C; Mari, Jair J; Manfro, Gisele G; Miguel, Eurípedes C; Paus, Tomás; Bressan, Rodrigo A; Rohde, Luis A; Salum, Giovanni A

2017-01-01

High rates of comorbidities and poor validity of disorder diagnostic criteria for mental disorders hamper advances in mental health research. Recent work has suggested the utility of continuous cross-cutting dimensions, including general psychopathology and specific factors of externalizing and internalizing (e.g., distress and fear) syndromes. The current study evaluated the reliability of competing structural models of psychopathology and examined external validity of the best fitting model on the basis of family risk and child global executive function (EF). A community sample of 8,012 families from Brazil with children ages 6-12 years completed structured interviews about the child and parental psychiatric syndromes, and a subsample of 2,395 children completed tasks assessing EF (i.e., working memory, inhibitory control, and time processing). Confirmatory factor analyses tested a series of structural models of psychopathology in both parents and children. The model with a general psychopathology factor ("P factor") with 3 specific factors (fear, distress, and externalizing) exhibited the best fit. The general P factor accounted for most of the variance in all models, with little residual variance explained by each of the 3 specific factors. In addition, associations between child and parental factors were mainly significant for the P factors and nonsignificant for the specific factors from the respective models. Likewise, the child P factor-but not the specific factors-was significantly associated with global child EF. Overall, our results provide support for a latent overarching P factor characterizing child psychopathology, supported by familial associations and child EF. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Parametric oesophageal multiple swallow scintigraphy for validation of dysphageal symptoms during external beam irradiation of mediastinal tumours

Energy Technology Data Exchange (ETDEWEB)

Brandt-Mainz, K.; Eising, E.G.; Bockisch, A. [Essen Univ. (Gesamthochschule) (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Mallek, D. von; Poettgen, C.; Stuschke, M.; Sack, H. [Klinik und Poliklinik fuer Strahlentherapie, Universitaetsklinikum Essen (Germany)

2001-03-01

The aim of the study was to evaluate dysphageal symptoms and to measure the effect of local analgesic treatment using parametric oesophageal multiple swallow scintigraphy (PES) during external beam irradiation of the mediastinal region. Fifteen patients (most with lung cancer) with dysphagia grade II underwent PES during external beam radiotherapy of the mediastinum before and after application of local analgesics. Dynamic parametric condensed images were recorded. The intensity of clinical symptoms was correlated with the emptying rate at 10 s (ER-10 s) and the mean transit time (MTT). Visual analysis of the images was performed and the results were correlated with the fields of irradiation portals. Of the 15 patients, 12 showed a correlation between irradiation portals and the region of oesophageal motility disorder. Concordant results of clinical symptoms and PES data were found. In nine patients with a decrease in dysphagia following local analgesia, an increase in mean ER-10 s and a decrease in MTT were observed. In three patients with deterioration in clinical symptoms after analgesic treatment, a similar decrease in mean ER-10 s was found, though MTT remained constant. In three patients with normal values, motility disorders were detected in the dynamic study. In conclusion, PES was found to be a sensitive tool for the validation of dysphageal symptoms in patients during external beam irradiation of mediastinal tumours and for the evaluation and quantification of the efficacy of local analgesic treatment. Additional visual analysis of the dynamic study is helpful in diagnosing minimal disorders. (orig.)

Parametric oesophageal multiple swallow scintigraphy for validation of dysphageal symptoms during external beam irradiation of mediastinal tumours

International Nuclear Information System (INIS)

Brandt-Mainz, K.; Eising, E.G.; Bockisch, A.

2001-01-01

The aim of the study was to evaluate dysphageal symptoms and to measure the effect of local analgesic treatment using parametric oesophageal multiple swallow scintigraphy (PES) during external beam irradiation of the mediastinal region. Fifteen patients (most with lung cancer) with dysphagia grade II underwent PES during external beam radiotherapy of the mediastinum before and after application of local analgesics. Dynamic parametric condensed images were recorded. The intensity of clinical symptoms was correlated with the emptying rate at 10 s (ER-10 s) and the mean transit time (MTT). Visual analysis of the images was performed and the results were correlated with the fields of irradiation portals. Of the 15 patients, 12 showed a correlation between irradiation portals and the region of oesophageal motility disorder. Concordant results of clinical symptoms and PES data were found. In nine patients with a decrease in dysphagia following local analgesia, an increase in mean ER-10 s and a decrease in MTT were observed. In three patients with deterioration in clinical symptoms after analgesic treatment, a similar decrease in mean ER-10 s was found, though MTT remained constant. In three patients with normal values, motility disorders were detected in the dynamic study. In conclusion, PES was found to be a sensitive tool for the validation of dysphageal symptoms in patients during external beam irradiation of mediastinal tumours and for the evaluation and quantification of the efficacy of local analgesic treatment. Additional visual analysis of the dynamic study is helpful in diagnosing minimal disorders. (orig.)

On the validity of language: speaking, knowing and understanding in medical geography.

Science.gov (United States)

Scarpaci, J L

1993-09-01

This essay examines methodological problems concerning the conceptualization and operationalization of phenomena central to medical geography. Its main argument is that qualitative research can be strengthened if the differences between instrumental and apparent validity are better understood than the current research in medical geography suggests. Its premise is that our definitions of key terms and concepts must be reinforced throughout the design of research should our knowledge and understanding be enhanced. In doing so, the paper aims to move the methodological debate beyond the simple dichotomies of quantitative vs qualitative approaches and logical positivism vs phenomenology. Instead, the argument is couched in a postmodernist hermeneutic sense which questions the validity of one discourse of investigation over another. The paper begins by discussing methods used in conceptualizing and operationalizing variables in quantitative and qualitative research design. Examples derive from concepts central to a geography of health-care behavior and well-being. The latter half of the essay shows the uses and misuses of validity studies in selected health services research and the current debate on national health insurance.

Modal response of interior mass based upon external measurements

International Nuclear Information System (INIS)

Chow, C T; Eli, M; Jorgensen, B R; Woehrle, T.

1999-01-01

Modal response testing has been used to predict the motion of interior masses of a system in which only external instrumentation is allowed. Testing of this form may occasionally be necessary in validation of a computer model, but also has potential as a tool for validating individual assemblies in a QA process. Examination of the external frequency response and mode shapes can offer insight into interior response. The interpretation of these results is improved through parallel analytical solutions. A simple, three-mass model has been examined experimentally and analytically to demonstrate modal theory. These results show the limitations of the external measurement in predicting internal response due to transmissibility. A procedure for utilizing external testing is described. The question posed through this research is whether or not modal correlation analysis can be adapted for use in systems for which instrumentation of critical components is missing

External validation of the MRI-DRAGON score: early prediction of stroke outcome after intravenous thrombolysis.

Science.gov (United States)

Turc, Guillaume; Aguettaz, Pierre; Ponchelle-Dequatre, Nelly; Hénon, Hilde; Naggara, Olivier; Leclerc, Xavier; Cordonnier, Charlotte; Leys, Didier; Mas, Jean-Louis; Oppenheim, Catherine

2014-01-01

The aim of our study was to validate in an independent cohort the MRI-DRAGON score, an adaptation of the (CT-) DRAGON score to predict 3-month outcome in acute ischemic stroke patients undergoing MRI before intravenous thrombolysis (IV-tPA). We reviewed consecutive (2009-2013) anterior circulation stroke patients treated within 4.5 hours by IV-tPA in the Lille stroke unit (France), where MRI is the first-line pretherapeutic work-up. We assessed the discrimination and calibration of the MRI-DRAGON score to predict poor 3-month outcome, defined as modified Rankin Score >2, using c-statistic and the Hosmer-Lemeshow test, respectively. We included 230 patients (mean ±SD age 70.4±16.0 years, median [IQR] baseline NIHSS 8 [5]-[14]; poor outcome in 78(34%) patients). The c-statistic was 0.81 (95%CI 0.75-0.87), and the Hosmer-Lemeshow test was not significant (p = 0.54). The MRI-DRAGON score showed good prognostic performance in the external validation cohort. It could therefore be used to inform the patient's relatives about long-term prognosis and help to identify poor responders to IV-tPA alone, who may be candidates for additional therapeutic strategies, if they are otherwise eligible for such procedures based on the institutional criteria.

External validation of the MRI-DRAGON score: early prediction of stroke outcome after intravenous thrombolysis.

Directory of Open Access Journals (Sweden)

Guillaume Turc

Full Text Available The aim of our study was to validate in an independent cohort the MRI-DRAGON score, an adaptation of the (CT- DRAGON score to predict 3-month outcome in acute ischemic stroke patients undergoing MRI before intravenous thrombolysis (IV-tPA.We reviewed consecutive (2009-2013 anterior circulation stroke patients treated within 4.5 hours by IV-tPA in the Lille stroke unit (France, where MRI is the first-line pretherapeutic work-up. We assessed the discrimination and calibration of the MRI-DRAGON score to predict poor 3-month outcome, defined as modified Rankin Score >2, using c-statistic and the Hosmer-Lemeshow test, respectively.We included 230 patients (mean ±SD age 70.4±16.0 years, median [IQR] baseline NIHSS 8 [5]-[14]; poor outcome in 78(34% patients. The c-statistic was 0.81 (95%CI 0.75-0.87, and the Hosmer-Lemeshow test was not significant (p = 0.54.The MRI-DRAGON score showed good prognostic performance in the external validation cohort. It could therefore be used to inform the patient's relatives about long-term prognosis and help to identify poor responders to IV-tPA alone, who may be candidates for additional therapeutic strategies, if they are otherwise eligible for such procedures based on the institutional criteria.

Validation of virtual reality as a tool to understand and prevent child pedestrian injury.

Science.gov (United States)

Schwebel, David C; Gaines, Joanna; Severson, Joan

2008-07-01

In recent years, virtual reality has emerged as an innovative tool for health-related education and training. Among the many benefits of virtual reality is the opportunity for novice users to engage unsupervised in a safe environment when the real environment might be dangerous. Virtual environments are only useful for health-related research, however, if behavior in the virtual world validly matches behavior in the real world. This study was designed to test the validity of an immersive, interactive virtual pedestrian environment. A sample of 102 children and 74 adults was recruited to complete simulated road-crossings in both the virtual environment and the identical real environment. In both the child and adult samples, construct validity was demonstrated via significant correlations between behavior in the virtual and real worlds. Results also indicate construct validity through developmental differences in behavior; convergent validity by showing correlations between parent-reported child temperament and behavior in the virtual world; internal reliability of various measures of pedestrian safety in the virtual world; and face validity, as measured by users' self-reported perception of realism in the virtual world. We discuss issues of generalizability to other virtual environments, and the implications for application of virtual reality to understanding and preventing pediatric pedestrian injuries.

A computable phenotype for asthma case identification in adult and pediatric patients: External validation in the Chicago Area Patient-Outcomes Research Network (CAPriCORN).

Science.gov (United States)

Afshar, Majid; Press, Valerie G; Robison, Rachel G; Kho, Abel N; Bandi, Sindhura; Biswas, Ashvini; Avila, Pedro C; Kumar, Harsha Vardhan Madan; Yu, Byung; Naureckas, Edward T; Nyenhuis, Sharmilee M; Codispoti, Christopher D

2017-10-13

Comprehensive, rapid, and accurate identification of patients with asthma for clinical care and engagement in research efforts is needed. The original development and validation of a computable phenotype for asthma case identification occurred at a single institution in Chicago and demonstrated excellent test characteristics. However, its application in a diverse payer mix, across different health systems and multiple electronic health record vendors, and in both children and adults was not examined. The objective of this study is to externally validate the computable phenotype across diverse Chicago institutions to accurately identify pediatric and adult patients with asthma. A cohort of 900 asthma and control patients was identified from the electronic health record between January 1, 2012 and November 30, 2014. Two physicians at each site independently reviewed the patient chart to annotate cases. The inter-observer reliability between the physician reviewers had a κ-coefficient of 0.95 (95% CI 0.93-0.97). The accuracy, sensitivity, specificity, negative predictive value, and positive predictive value of the computable phenotype were all above 94% in the full cohort. The excellent positive and negative predictive values in this multi-center external validation study establish a useful tool to identify asthma cases in in the electronic health record for research and care. This computable phenotype could be used in large-scale comparative-effectiveness trials.

External Validity of a Risk Stratification Score Predicting Early Distant Brain Failure and Salvage Whole Brain Radiation Therapy After Stereotactic Radiosurgery for Brain Metastases.

Science.gov (United States)

Press, Robert H; Boselli, Danielle M; Symanowski, James T; Lankford, Scott P; McCammon, Robert J; Moeller, Benjamin J; Heinzerling, John H; Fasola, Carolina E; Burri, Stuart H; Patel, Kirtesh R; Asher, Anthony L; Sumrall, Ashley L; Curran, Walter J; Shu, Hui-Kuo G; Crocker, Ian R; Prabhu, Roshan S

2017-07-01

A scoring system using pretreatment factors was recently published for predicting the risk of early (≤6 months) distant brain failure (DBF) and salvage whole brain radiation therapy (WBRT) after stereotactic radiosurgery (SRS) alone. Four risk factors were identified: (1) lack of prior WBRT; (2) melanoma or breast histologic features; (3) multiple brain metastases; and (4) total volume of brain metastases external patient population. We reviewed the records of 247 patients with 388 brain metastases treated with SRS between 2010 at 2013 at Levine Cancer Institute. The Press (Emory) risk score was calculated and applied to the validation cohort population, and subsequent risk groups were analyzed using cumulative incidence. The low-risk (LR) group had a significantly lower risk of early DBF than did the high-risk (HR) group (22.6% vs 44%, P=.004), but there was no difference between the HR and intermediate-risk (IR) groups (41.2% vs 44%, P=.79). Total lesion volume externally valid, but the model was able to stratify between 2 levels (LR and not-LR [combined IR and HR]) for early (≤6 months) DBF. These results reinforce the importance of validating predictive models in independent cohorts. Further refinement of this scoring system with molecular information and in additional contemporary patient populations is warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

Serum Gamma-Glutamyl-Transferase Independently Predicts Outcome After Transarterial Chemoembolization of Hepatocellular Carcinoma: External Validation

Energy Technology Data Exchange (ETDEWEB)

Guiu, Boris, E-mail: boris.guiu@chu-dijon.fr; Deschamps, Frederic [Institut Gustave Roussy, Department of Interventional Radiology (France); Boulin, Mathieu [University Hospital, INSERM U866 (France); Boige, Valerie; Malka, David; Ducreux, Michel [Institut Gustave Roussy, Department of Digestive Oncology (France); Hillon, Patrick [University Hospital, INSERM U866 (France); Baere, Thierry de [Institut Gustave Roussy, Department of Interventional Radiology (France)

2012-10-15

Purpose: An Asian study showed that gamma glutamyl transpeptidase (GGT) can predict survival after transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). This study was designed to validate in a European population this biomarker as an independent predictor of outcome after TACE of HCC and to determine a threshold value for clinical use. Methods: In 88 consecutive patients treated by TACE for HCC, the optimal threshold for GGT serum level was determined by a ROC analysis. Endpoints were time-to-treatment failure (TTTF) and overall survival (OS). All multivariate models were internally validated using bootstrapping (90 replications). Results: Median follow-up lasted 373 days, and median overall survival was 748 days. The optimal threshold for GGT was 165 U/L (sensitivity: 89.3%; specificity: 56.7%; area under the ROC curve: 0.7515). Median TTTF was shorter when GGT was {>=}165 U/L (281 days vs. 850 days; P < 0.001). GGT {>=}165 U/L (hazard ratio (HR) = 2.06; P = 0.02), WHO PS of 2 (HR = 5.4; P = 0.002), and tumor size (HR = 1.12; P = 0.014) were independently associated with shorter TTTF. Median OS was shorter when GGT was {>=}165 U/L (508 days vs. not reached; P < 0.001). GGT {>=} 165 U/L (HR = 3.05; P = 0.029), WHO PS of 2 (HR = 12.95; P < 0.001), alfa-fetoprotein (HR = 2.9; P = 0.01), and tumor size (HR = 1.096; P = 0.013) were independently associated with shorter OS. The results were confirmed by bootstrapping. Conclusions: Our results provide in a European population the external validation of GGT as an independent predictor of outcome after TACE of HCC. A serum level of GGT {>=} 165 U/L is independently associated with both shorter TTTF and OS.

Serum Gamma-Glutamyl-Transferase Independently Predicts Outcome After Transarterial Chemoembolization of Hepatocellular Carcinoma: External Validation

International Nuclear Information System (INIS)

Guiu, Boris; Deschamps, Frédéric; Boulin, Mathieu; Boige, Valérie; Malka, David; Ducreux, Michel; Hillon, Patrick; Baère, Thierry de

2012-01-01

Purpose: An Asian study showed that gamma glutamyl transpeptidase (GGT) can predict survival after transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). This study was designed to validate in a European population this biomarker as an independent predictor of outcome after TACE of HCC and to determine a threshold value for clinical use. Methods: In 88 consecutive patients treated by TACE for HCC, the optimal threshold for GGT serum level was determined by a ROC analysis. Endpoints were time-to-treatment failure (TTTF) and overall survival (OS). All multivariate models were internally validated using bootstrapping (90 replications). Results: Median follow-up lasted 373 days, and median overall survival was 748 days. The optimal threshold for GGT was 165 U/L (sensitivity: 89.3%; specificity: 56.7%; area under the ROC curve: 0.7515). Median TTTF was shorter when GGT was ≥165 U/L (281 days vs. 850 days; P < 0.001). GGT ≥165 U/L (hazard ratio (HR) = 2.06; P = 0.02), WHO PS of 2 (HR = 5.4; P = 0.002), and tumor size (HR = 1.12; P = 0.014) were independently associated with shorter TTTF. Median OS was shorter when GGT was ≥165 U/L (508 days vs. not reached; P < 0.001). GGT ≥ 165 U/L (HR = 3.05; P = 0.029), WHO PS of 2 (HR = 12.95; P < 0.001), alfa-fetoprotein (HR = 2.9; P = 0.01), and tumor size (HR = 1.096; P = 0.013) were independently associated with shorter OS. The results were confirmed by bootstrapping. Conclusions: Our results provide in a European population the external validation of GGT as an independent predictor of outcome after TACE of HCC. A serum level of GGT ≥ 165 U/L is independently associated with both shorter TTTF and OS.

Efficacy and External Validity of Electronic and Mobile Phone-Based Interventions Promoting Vegetable Intake in Young Adults: Systematic Review and Meta-Analysis.

Science.gov (United States)

Nour, Monica; Chen, Juliana; Allman-Farinelli, Margaret

2016-04-08

Young adults (18-35 years) remain among the lowest vegetable consumers in many western countries. The digital era offers opportunities to engage this age group in interventions in new and appealing ways. This systematic review evaluated the efficacy and external validity of electronic (eHealth) and mobile phone (mHealth) -based interventions that promote vegetable intake in young adults. We searched several electronic databases for studies published between 1990 and 2015, and 2 independent authors reviewed the quality and risk of bias of the eligible papers and extracted data for analyses. The primary outcome of interest was the change in vegetable intake postintervention. Where possible, we calculated effect sizes (Cohen d and 95% CIs) for comparison. A random effects model was applied to the data for meta-analysis. Reach and representativeness of participants, intervention implementation, and program maintenance were assessed to establish external validity. Published validation studies were consulted to determine the validity of tools used to measure intake. We applied the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to evaluate the overall quality of the body of evidence. Of the 14 studies that met the selection criteria, we included 12 in the meta-analysis. In the meta-analysis, 7 studies found positive effects postintervention for fruit and vegetable intake, Cohen d 0.14-0.56 (pooled effect size 0.22, 95% CI 0.11-0.33, I(2)=68.5%, P=.002), and 4 recorded positive effects on vegetable intake alone, Cohen d 0.11-0.40 (pooled effect size 0.15, 95% CI 0.04-0.28, I(2)=31.4%, P=.2). These findings should be interpreted with caution due to variability in intervention design and outcome measures. With the majority of outcomes documented as a change in combined fruit and vegetable intake, it was difficult to determine intervention effects on vegetable consumption specifically. Measurement of intake was most commonly by self

Assessing middle school students` understanding of science relationships and processes: Year 2 - instrument validation. Final report

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Schau, C.; Mattern, N.; Weber, R.; Minnick, K.

1997-01-01

Our overall purpose for this multi-year project was to develop an alternative assessment format measuring rural middle school students understanding of science concepts and processes and the interrelationships among them. This kind of understanding is called structural knowledge. We had 3 major interrelated goals: (1) Synthesize the existing literature and critically evaluate the actual and potential use of measures of structural knowledge in science education. (2) Develop a structural knowledge alternative assessment format. (3) Examine the validity of our structural knowledge format. We accomplished the first two goals during year 1. The structural knowledge assessment we identified and developed further was a select-and-fill-in concept map format. The goal for our year 2 work was to begin to validate this assessment approach. This final report summarizes our year 2 work.

Using process elicitation and validation to understand and improve chemotherapy ordering and delivery.

Science.gov (United States)

Mertens, Wilson C; Christov, Stefan C; Avrunin, George S; Clarke, Lori A; Osterweil, Leon J; Cassells, Lucinda J; Marquard, Jenna L

2012-11-01

Chemotherapy ordering and administration, in which errors have potentially severe consequences, was quantitatively and qualitatively evaluated by employing process formalism (or formal process definition), a technique derived from software engineering, to elicit and rigorously describe the process, after which validation techniques were applied to confirm the accuracy of the described process. The chemotherapy ordering and administration process, including exceptional situations and individuals' recognition of and responses to those situations, was elicited through informal, unstructured interviews with members of an interdisciplinary team. The process description (or process definition), written in a notation developed for software quality assessment purposes, guided process validation (which consisted of direct observations and semistructured interviews to confirm the elicited details for the treatment plan portion of the process). The overall process definition yielded 467 steps; 207 steps (44%) were dedicated to handling 59 exceptional situations. Validation yielded 82 unique process events (35 new expected but not yet described steps, 16 new exceptional situations, and 31 new steps in response to exceptional situations). Process participants actively altered the process as ambiguities and conflicts were discovered by the elicitation and validation components of the study. Chemotherapy error rates declined significantly during and after the project, which was conducted from October 2007 through August 2008. Each elicitation method and the subsequent validation discussions contributed uniquely to understanding the chemotherapy treatment plan review process, supporting rapid adoption of changes, improved communication regarding the process, and ensuing error reduction.

Experimental validation of a radio frequency photogun as external electron

NARCIS (Netherlands)

Stragier, X.F.D.; Luiten, O.J.; Geer, van der S.B.; Wiel, van der M.J.

2011-01-01

A purpose-built RF-photogun as external electron injector for a laser wakefield accelerator has been thoroughly tested. Different properties of the RF-photogun have been measured such as energy, energy spread and transverse emittance. The focus of this study is the investigation of the smallest

Development and validation of a method for measuring depth of understanding in constructivist learning

Science.gov (United States)

Guarino, Lucia Falsetti

A method for measuring depth of understanding of students in the middle-level science classroom was developed and validated. A common theme in the literature on constructivism in science education is that constructivist pedagogy, as opposed to objectivist pedagogy, results in a greater depth of understanding. Since few instruments measuring this construct exist at the present time, the development of such a tool to measure this construct was a significant contribution to the current body of assessment technologies in science education. The author's Depth of Understanding Assessment (DUA) evolved from a writing measure originally designed as a history assessment. The study involved 230 eighth grade science students studying a chemical change unit. The main research questions were: (1) What is the relationship between the DUA and each of the following independent variables: recall, application, and questioning modalities as measured by the Cognitive Preference Test; deep, surface, achieving, and deep-achieving approaches as measured by the Learning Process Questionnaire; achievement as measured by the Chemical Change Quiz, and teacher perception of student ability to conceptualize science content? (2) Is there a difference in depth of understanding, as measured by the DUA, between students who are taught by objectivist pedagogy and students who are taught by constructivist pedagogy favoring the constructivist group? (3) Is there a gender difference in depth of understanding as measured by the DUA? (4) Do students who are taught by constructivist pedagogy perceive their learning environment as more constructivist than students who are taught by objectivist pedagogy? Six out of nine hypothesis tests supported the validity of the DUA. The results of the qualitative component of this study which consisted of student interviews substantiated the quantitative results by providing additional information and insights. There was a significant difference in depth of

Update of the German Diabetes Risk Score and external validation in the German MONICA/KORA study.

Science.gov (United States)

Mühlenbruch, Kristin; Ludwig, Tonia; Jeppesen, Charlotte; Joost, Hans-Georg; Rathmann, Wolfgang; Meisinger, Christine; Peters, Annette; Boeing, Heiner; Thorand, Barbara; Schulze, Matthias B

2014-06-01

Several published diabetes prediction models include information about family history of diabetes. The aim of this study was to extend the previously developed German Diabetes Risk Score (GDRS) with family history of diabetes and to validate the updated GDRS in the Multinational MONItoring of trends and determinants in CArdiovascular Diseases (MONICA)/German Cooperative Health Research in the Region of Augsburg (KORA) study. We used data from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study for extending the GDRS, including 21,846 participants. Within 5 years of follow-up 492 participants developed diabetes. The definition of family history included information about the father, the mother and/or sibling/s. Model extension was evaluated by discrimination and reclassification. We updated the calculation of the score and absolute risks. External validation was performed in the MONICA/KORA study comprising 11,940 participants with 315 incident cases after 5 years of follow-up. The basic ROC-AUC of 0.856 (95%-CI: 0.842-0.870) was improved by 0.007 (0.003-0.011) when parent and sibling history was included in the GDRS. The net reclassification improvement was 0.110 (0.072-0.149), respectively. For the updated score we demonstrated good calibration across all tenths of risk. In MONICA/KORA, the ROC-AUC was 0.837 (0.819-0.855); regarding calibration we saw slight overestimation of absolute risks. Inclusion of the number of diabetes-affected parents and sibling history improved the prediction of type 2 diabetes. Therefore, we updated the GDRS algorithm accordingly. Validation in another German cohort study showed good discrimination and acceptable calibration for the vast majority of individuals. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

External validation of three dimensional conformal radiotherapy based NTCP models for patient-rated xerostomia and sticky saliva among patients treated with intensity modulated radiotherapy

International Nuclear Information System (INIS)

Beetz, Ivo; Schilstra, Cornelis; Luijk, Peter van; Christianen, Miranda E.M.C.; Doornaert, Patricia; Bijl, Henk P.; Chouvalova, Olga; Heuvel, Edwin R. van den; Steenbakkers, Roel J.H.M.; Langendijk, Johannes A.

2012-01-01

Purpose: The purpose of this study was to investigate the ability of predictive models for patient-rated xerostomia (XER 6M ) and sticky saliva (STIC 6M ) at 6 months after completion of primary (chemo)radiation developed in head and neck cancer patients treated with 3D-conformal radiotherapy (3D-CRT) to predict outcome in patients treated with intensity modulated radiotherapy (IMRT). Methods and materials: Recently, we published the results of a prospective study on predictive models for patient-rated xerostomia and sticky saliva in head and neck cancer patients treated with 3D-CRT (3D-CRT based NTCP models). The 3D-CRT based model for XER 6M consisted of three factors, including the mean parotid dose, age, and baseline xerostomia (none versus a bit). The 3D-CRT based model for STIC 6M consisted of the mean submandibular dose, age, the mean sublingual dose, and baseline sticky saliva (none versus a bit). In the current study, a population consisting of 162 patients treated with IMRT was used to test the external validity of these 3D-CRT based models. External validity was described by the explained variation (R 2 Nagelkerke) and the Brier score. The discriminative abilities of the models were calculated using the area under the receiver operating curve (AUC) and calibration (i.e. the agreement between predicted and observed outcome) was assessed with the Hosmer–Lemeshow “goodness-of-fit” test. Results: Overall model performance of the 3D-CRT based predictive models for XER 6M and STIC 6M was significantly worse in terms of the Brier score and R 2 Nagelkerke among patients treated with IMRT. Moreover the AUC for both 3D-CRT based models in the IMRT treated patients were markedly lower. The Hosmer–Lemeshow test showed a significant disagreement for both models between predicted risk and observed outcome. Conclusion: 3D-CRT based models for patient-rated xerostomia and sticky saliva among head and neck cancer patients treated with primary radiotherapy or

Validation of an amino-acid-based radionuclide therapy plus external beam radiotherapy in heterotopic glioblastoma models

Energy Technology Data Exchange (ETDEWEB)

Israel, Ina [Department of Nuclear Medicine, University of Wuerzburg, D-97080 Wuerzburg (Germany); Blass, Georg [Department of Radiotherapy and Radiooncology, Saarland University Medical Center, Homburg (Germany); Reiners, Christoph [Department of Nuclear Medicine, University of Wuerzburg, D-97080 Wuerzburg (Germany); Samnick, Samuel, E-mail: samnick_s@klinik.uni-wuerzburg.d [Department of Nuclear Medicine, University of Wuerzburg, D-97080 Wuerzburg (Germany)

2011-05-15

Background and purpose: Malignant gliomas represent a major therapeutic challenge because no efficient treatment is currently available. p-[{sup 131}I]iodo-L-phenylalanine ([{sup 131}I]IPA) is a glioma avid radiopharmaceutical that demonstrated antiproliferative and tumoricidal effects in gliomas. The present study validated the therapeutic efficiency of [{sup 131}I]IPA combined with external beam radiotherapy in experimental gliomas. Materials and methods: Glioma cells derived from the primary human A1207, T5135, Tx3868 and M059K glioblastoma cell lines or rat F98 glioma cell line were treated with various doses of [{sup 131}I]IPA, external photon irradiation (RT) or combined [{sup 131}I]IPA/RT treatment. Responsiveness of glioma cells to the different therapy modalities was investigated at 24, 48 and 72 h after treatments by trypan blue, WST-1 assay, propidium iodide and bisbenzimide staining as well as by clonogenic assay. In addition, the therapy-induced DNA damage and repair were evaluated using phosphorylated histone H2AX ({gamma}-H2AX). In vivo, the effectiveness of the combination treatment was validated in human Tx3868 and A1207 glioblastoma xenografts in CD1 nu/nu mice and RNU rats. Results: In vitro, the combination treatment resulted in a greater than additive increase in cytotoxic effect in glioma cell lines. Cell survival rate following a treatment with 1.0 {mu}Ci (37 kBq) of [{sup 131}I]IPA amounted to 70%{+-}15% and 60%{+-}10% after 48 and 72 h, respectively, and decreased under 20% after additional RT with 5 Gy. At higher RT doses, cell survival rate decreased below 5%. As a measure of DNA double-strand break, nuclear {gamma}-H2AX foci were determined as a function of time. Within 24 h, the number of {gamma}-H2AX foci per cell was significantly greater after combined modality compared with the individual treatments. In vivo, when combined with RT, the radionuclide therapy with [{sup 131}I]IPA resulted in an extended tumor growth delay, a reduction

External validation and newly development of a nomogram to predict overall survival of abiraterone-treated, castration-resistant patients with metastatic prostate cancer

Directory of Open Access Journals (Sweden)

Yun-Jie Yang

2018-01-01

Full Text Available Abiraterone acetate is approved for the treatment of castration-resistant prostate cancer (CRPC; however, its effects vary. An accurate prediction model to identify patient groups that will benefit from abiraterone treatment is therefore urgently required. The Chi model exhibits a good profile for risk classification, although its utility for the chemotherapy-naive group is unclear. This study aimed to externally validate the Chi model and develop a new nomogram to predict overall survival (OS. We retrospectively analyzed a cohort of 110 patients. Patients were distributed among good-, intermediate-, and poor-risk groups, according to the Chi model. The good-, intermediate-, and poor-risk groups had a sample size of 59 (53.6%, 34 (30.9%, and 17 (15.5% in our dataset, and a median OS of 48.4, 29.1, and 10.5 months, respectively. The C-index of external validation of Chi model was 0.726. Univariate and multivariate analyses identified low hemoglobin concentrations (<110 g l−1, liver metastasis, and a short time interval from androgen deprivation therapy to abiraterone initiation (<36 months as predictors of OS. Accordingly, a new nomogram was developed with a C-index equal to 0.757 (95% CI, 0.678–0.836. In conclusion, the Chi model predicted the prognosis of abiraterone-treated, chemotherapy-naive patients with mCRPC, and we developed a new nomogram to predict the overall survival of this group of patients with less parameters.

Developing and validating a conceptual survey to assess introductory physics students’ understanding of magnetism

Science.gov (United States)

Li, Jing; Singh, Chandralekha

2017-03-01

Development of validated physics surveys on various topics is important for investigating the extent to which students master those concepts after traditional instruction and for assessing innovative curricula and pedagogies that can improve student understanding significantly. Here, we discuss the development and validation of a conceptual multiple-choice survey related to magnetism suitable for introductory physics courses. The survey was developed taking into account common students’ difficulties with magnetism concepts covered in introductory physics courses found in our investigation and the incorrect choices to the multiple-choice questions were designed based upon those common student difficulties. After the development and validation of the survey, it was administered to introductory physics students in various classes in paper-pencil format before and after traditional lecture-based instruction in relevant concepts. We compared the performance of students on the survey in the algebra-based and calculus-based introductory physics courses before and after traditional lecture-based instruction in relevant magnetism concepts. We discuss the common difficulties of introductory physics students with magnetism concepts we found via the survey. We also administered the survey to upper-level undergraduates majoring in physics and PhD students to benchmark the survey and compared their performance with those of traditionally taught introductory physics students for whom the survey is intended. A comparison with the base line data on the validated magnetism survey from traditionally taught introductory physics courses and upper-level undergraduate and PhD students discussed in this paper can help instructors assess the effectiveness of curricula and pedagogies which is especially designed to help students integrate conceptual and quantitative understanding and develop a good grasp of the concepts. In particular, if introductory physics students’ average

Developing and validating a conceptual survey to assess introductory physics students’ understanding of magnetism

International Nuclear Information System (INIS)

Li, Jing; Singh, Chandralekha

2017-01-01

Development of validated physics surveys on various topics is important for investigating the extent to which students master those concepts after traditional instruction and for assessing innovative curricula and pedagogies that can improve student understanding significantly. Here, we discuss the development and validation of a conceptual multiple-choice survey related to magnetism suitable for introductory physics courses. The survey was developed taking into account common students’ difficulties with magnetism concepts covered in introductory physics courses found in our investigation and the incorrect choices to the multiple-choice questions were designed based upon those common student difficulties. After the development and validation of the survey, it was administered to introductory physics students in various classes in paper–pencil format before and after traditional lecture-based instruction in relevant concepts. We compared the performance of students on the survey in the algebra-based and calculus-based introductory physics courses before and after traditional lecture-based instruction in relevant magnetism concepts. We discuss the common difficulties of introductory physics students with magnetism concepts we found via the survey. We also administered the survey to upper-level undergraduates majoring in physics and PhD students to benchmark the survey and compared their performance with those of traditionally taught introductory physics students for whom the survey is intended. A comparison with the base line data on the validated magnetism survey from traditionally taught introductory physics courses and upper-level undergraduate and PhD students discussed in this paper can help instructors assess the effectiveness of curricula and pedagogies which is especially designed to help students integrate conceptual and quantitative understanding and develop a good grasp of the concepts. In particular, if introductory physics students’ average

An External Independent Validation of APACHE IV in a Malaysian Intensive Care Unit.

Science.gov (United States)

Wong, Rowena S Y; Ismail, Noor Azina; Tan, Cheng Cheng

2015-04-01

Intensive care unit (ICU) prognostic models are predominantly used in more developed nations such as the United States, Europe and Australia. These are not that popular in Southeast Asian countries due to costs and technology considerations. The purpose of this study is to evaluate the suitability of the acute physiology and chronic health evaluation (APACHE) IV model in a single centre Malaysian ICU. A prospective study was conducted at the single centre ICU in Hospital Sultanah Aminah (HSA) Malaysia. External validation of APACHE IV involved a cohort of 916 patients who were admitted in 2009. Model performance was assessed through its calibration and discrimination abilities. A first-level customisation using logistic regression approach was also applied to improve model calibration. APACHE IV exhibited good discrimination, with an area under receiver operating characteristic (ROC) curve of 0.78. However, the model's overall fit was observed to be poor, as indicated by the Hosmer-Lemeshow goodness-of-fit test (Ĉ = 113, P discrimination was not affected. APACHE IV is not suitable for application in HSA ICU, without further customisation. The model's lack of fit in the Malaysian study is attributed to differences in the baseline characteristics between HSA ICU and APACHE IV datasets. Other possible factors could be due to differences in clinical practice, quality and services of health care systems between Malaysia and the United States.

Multicenter external validation of two malignancy risk prediction models in patients undergoing 18F-FDG-PET for solitary pulmonary nodule evaluation

International Nuclear Information System (INIS)

Perandini, Simone; Soardi, G.A.; Signorini, M.; Motton, M.; Montemezzi, S.; Larici, A.R.; Del Ciello, A.; Rizzardi, G.; Solazzo, A.; Mancino, L.; Zeraj, F.; Bernhart, M.

2017-01-01

To achieve multicentre external validation of the Herder and Bayesian Inference Malignancy Calculator (BIMC) models. Two hundred and fifty-nine solitary pulmonary nodules (SPNs) collected from four major hospitals which underwent 18-FDG-PET characterization were included in this multicentre retrospective study. The Herder model was tested on all available lesions (group A). A subgroup of 180 SPNs (group B) was used to provide unbiased comparison between the Herder and BIMC models. Receiver operating characteristic (ROC) area under the curve (AUC) analysis was performed to assess diagnostic accuracy. Decision analysis was performed by adopting the risk threshold stated in British Thoracic Society (BTS) guidelines. Unbiased comparison performed In Group B showed a ROC AUC for the Herder model of 0.807 (95 % CI 0.742-0.862) and for the BIMC model of 0.822 (95 % CI 0.758-0.875). Both the Herder and the BIMC models were proven to accurately predict the risk of malignancy when tested on a large multicentre external case series. The BIMC model seems advantageous on the basis of a more favourable decision analysis. (orig.)

Multicenter external validation of two malignancy risk prediction models in patients undergoing 18F-FDG-PET for solitary pulmonary nodule evaluation

Energy Technology Data Exchange (ETDEWEB)

Perandini, Simone; Soardi, G.A.; Signorini, M.; Motton, M.; Montemezzi, S. [Azienda Ospedaliera Universitaria Integrata di Verona, UOC Radiologia, Ospedale Maggiore di Borgo Trento, Verona (Italy); Larici, A.R.; Del Ciello, A. [Universita Cattolica del Sacro Cuore, Dipartimento di Scienze Radiologiche, Roma (Italy); Rizzardi, G. [Ospedale Humanitas Gavazzeni, UO Chirurgia Toracica, Bergamo (Italy); Solazzo, A. [Ospedale Humanitas Gavazzeni, UO Radiologia, Bergamo (Italy); Mancino, L.; Zeraj, F. [Ospedale dell' Angelo di Mestre, UO Pneumologia, Venezia (Italy); Bernhart, M. [Ospedale dell' Angelo di Mestre, UO Radiologia, Venezia (Italy)

2017-05-15

To achieve multicentre external validation of the Herder and Bayesian Inference Malignancy Calculator (BIMC) models. Two hundred and fifty-nine solitary pulmonary nodules (SPNs) collected from four major hospitals which underwent 18-FDG-PET characterization were included in this multicentre retrospective study. The Herder model was tested on all available lesions (group A). A subgroup of 180 SPNs (group B) was used to provide unbiased comparison between the Herder and BIMC models. Receiver operating characteristic (ROC) area under the curve (AUC) analysis was performed to assess diagnostic accuracy. Decision analysis was performed by adopting the risk threshold stated in British Thoracic Society (BTS) guidelines. Unbiased comparison performed In Group B showed a ROC AUC for the Herder model of 0.807 (95 % CI 0.742-0.862) and for the BIMC model of 0.822 (95 % CI 0.758-0.875). Both the Herder and the BIMC models were proven to accurately predict the risk of malignancy when tested on a large multicentre external case series. The BIMC model seems advantageous on the basis of a more favourable decision analysis. (orig.)

External Validation and Optimization of International Consensus Clinical Target Volumes for Adjuvant Radiation Therapy in Bladder Cancer

Energy Technology Data Exchange (ETDEWEB)

Reddy, Abhinav V. [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States); Christodouleas, John P. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Wu, Tianming [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States); Smith, Norman D.; Steinberg, Gary D. [Section of Urology, Department of Surgery, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States); Liauw, Stanley L., E-mail: sliauw@radonc.uchicago.edu [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States)

2017-03-15

Purpose: International consensus (IC) clinical target volumes (CTVs) have been proposed to standardize radiation field design in the treatment of patients at high risk of locoregional failure (LRF) after radical cystectomy. The purpose of this study was to externally validate the IC CTVs in a cohort of postsurgical patients followed up for LRF and identify revisions that might improve the IC CTVs' performance. Methods and Materials: Among 334 patients with pT3 to pT4 bladder cancer treated with radical cystectomy, LRF developed in 58 (17%), of whom 52 had computed tomography scans available for review. Images with LRF were exported into a treatment planning system, and IC CTVs were contoured and evaluated for adequacy of coverage of each LRF with respect to both the patient and each of 6 pelvic subsites: common iliac (CI) region, obturator region (OR), external and internal iliac region, presacral region, cystectomy bed, or other pelvic site. Revisions to the IC contours were proposed based on the findings. Results: Of the 52 patients with documented LRF, 13 (25%) had LRFs that were outside of the IC CTV involving 17 pelvic subsites: 5 near the CI CTV, 5 near the OR CTV, 1 near the external and internal iliac region, and 6 near the cystectomy bed. The 5 CI failures were located superior to the CTV, and the 5 OR failures were located medial to the CTV. Increasing the superior boundary of the CI to a vessel-based definition of the aortic bifurcation, as well as increasing the medial extension of the OR by an additional 9 mm, decreased the number of patients with LRF outside of the IC CTV to 7 (13%). Conclusions: Modified IC CTVs inclusive of a slight adjustment superiorly for the CI region and medially for the OR may reduce the risk of pelvic failure in patients treated with adjuvant radiation therapy.

Technical review of externalities issues. Final report

International Nuclear Information System (INIS)

Niemeyer, V.

1994-12-01

Externalities has become the catchword for a major experiment in electric utility regulation. Together with increased competition as a means for economic regulation, this experiment represents a potential revolution in how electric utilities are regulated. It is very important for utilities and policy makers to understand the technical issues and arguments driving the externality experiment. This Technical Review presents four papers covering topics in economics that may play important roles in this revolution. The four papers are: Economic Issues in the Application of Externalities to Electricity Resource Selection; Climate Change, the Marginal Cost of Carbon Dioxide Emissions and the Implications for Carbon Dioxide Emissions Adders; Positive Externalities and Benefits from Electricity; and Socioeconomic Effects of Externality Adders for Electric Utility Emissions

Validity, reliability and understanding of the EORTC-C30 and EORTC-BR23, quality of life questionnaires specific for breast cancer

Directory of Open Access Journals (Sweden)

Fernanda Alessandra Silva Michels

2013-06-01

Full Text Available Objective: To validate and assess reliability and understanding of the EORTC–C30 quality of life questionnaire and its breast cancer specific module, the EORTC-BR23. Methods: This study was conducted at the AC Camargo Cancer Hospital, São Paulo, Brazil. A total of 100 women diagnosed with breast cancer were interviewed. Internal consistency, confirmatory factorial analysis, convergent validity, construct validity and degree of understanding were examined. Reliability was assessed by comparison of means at times 1 and 2, inter-class coefficient and Bland-Altman graphics. Results: Cronbach’s alpha ranged from 0.72 to 0.86 for the EORTC-C30 and from 0.78 to 0.83 for the EORTC-BR23 questionnaire. Most questions were confirmed in the confirmatory factorial analysis. In the construct validity analysis, the questionnaires were capable of differentiating patients with or without lymphedema, apart from the symptom scales of both questionnaires. Both questionnaires presented a significant correlation in most domains of the SF-36, in the convergent validity analysis. Only a few criticisms were reported concerning questions, and the mean grade of understanding was high (C30 = 4.91 and BR23 = 4.89. The questionnaires presented good rates of reliability, with the exception of the functional scale of the C30 and the symptom scale of the BR23. Conclusions: The EORTC-C30 and EORTC-BR23 quality of life questionnaires were validated, presented good rates of reliability and are easily understood, allowing them to be used in Brazil to assess quality of life among women with breast cancer.

Multicentre external validation of the BIMC model for solid solitary pulmonary nodule malignancy prediction

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Soardi, Gian Alberto; Perandini, Simone; Motton, Massimiliano; Montemezzi, Stefania [AOUI Verona, UOC Radiologia, Ospedale Maggiore di Borgo Trento, Verona (Italy); Larici, Anna Rita; Del Ciello, Annemilia [Universita Cattolica del Sacro Cuore, Dipartimento di Scienze Radiologiche, Roma (Italy); Rizzardi, Giovanna [UO Chirurgia Toracica, Ospedale Humanitas Gavazzeni, Bergamo (Italy); Solazzo, Antonio [UO Radiologia, Ospedale Humanitas Gavazzeni, Bergamo (Italy); Mancino, Laura [UO Pneumologia, Ospedale dell' Angelo di Mestre, Mestre (Italy); Bernhart, Marco [UO Radiologia, Ospedale dell' Angelo di Mestre, Mestre (Italy)

2017-05-15

To provide multicentre external validation of the Bayesian Inference Malignancy Calculator (BIMC) model by assessing diagnostic accuracy in a cohort of solitary pulmonary nodules (SPNs) collected in a clinic-based setting. To assess model impact on SPN decision analysis and to compare findings with those obtained via the Mayo Clinic model. Clinical and imaging data were retrospectively collected from 200 patients from three centres. Accuracy was assessed by means of receiver-operating characteristic (ROC) areas under the curve (AUCs). Decision analysis was performed by adopting both the American College of Chest Physicians (ACCP) and the British Thoracic Society (BTS) risk thresholds. ROC analysis showed an AUC of 0.880 (95 % CI, 0.832-0.928) for the BIMC model and of 0.604 (95 % CI, 0.524-0.683) for the Mayo Clinic model. Difference was 0.276 (95 % CI, 0.190-0.363, P < 0.0001). Decision analysis showed a slightly reduced number of false-negative and false-positive results when using ACCP risk thresholds. The BIMC model proved to be an accurate tool when characterising SPNs. In a clinical setting it can distinguish malignancies from benign nodules with minimal errors by adopting current ACCP or BTS risk thresholds and guiding lesion-tailored diagnostic and interventional procedures during the work-up. (orig.)

Using linked electronic data to validate algorithms for health outcomes in administrative databases.

Science.gov (United States)

Lee, Wan-Ju; Lee, Todd A; Pickard, Alan Simon; Shoaibi, Azadeh; Schumock, Glen T

2015-08-01

The validity of algorithms used to identify health outcomes in claims-based and administrative data is critical to the reliability of findings from observational studies. The traditional approach to algorithm validation, using medical charts, is expensive and time-consuming. An alternative method is to link the claims data to an external, electronic data source that contains information allowing confirmation of the event of interest. In this paper, we describe this external linkage validation method and delineate important considerations to assess the feasibility and appropriateness of validating health outcomes using this approach. This framework can help investigators decide whether to pursue an external linkage validation method for identifying health outcomes in administrative/claims data.

Development and Validation of the Spanish Numeracy Understanding in Medicine Instrument.

Science.gov (United States)

Jacobs, Elizabeth A; Walker, Cindy M; Miller, Tamara; Fletcher, Kathlyn E; Ganschow, Pamela S; Imbert, Diana; O'Connell, Maria; Neuner, Joan M; Schapira, Marilyn M

2016-11-01

The Spanish-speaking population in the U.S. is large and growing and is known to have lower health literacy than the English-speaking population. Less is known about the health numeracy of this population due to a lack of health numeracy measures in Spanish. we aimed to develop and validate a short and easy to use measure of health numeracy for Spanish-speaking adults: the Spanish Numeracy Understanding in Medicine Instrument (Spanish-NUMi). Items were generated based on qualitative studies in English- and Spanish-speaking adults and translated into Spanish using a group translation and consensus process. Candidate items for the Spanish NUMi were selected from an eight-item validated English Short NUMi. Differential Item Functioning (DIF) was conducted to evaluate equivalence between English and Spanish items. Cronbach's alpha was computed as a measure of reliability and a Pearson's correlation was used to evaluate the association between test scores and the Spanish Test of Functional Health Literacy (S-TOFHLA) and education level. Two-hundred and thirty-two Spanish-speaking Chicago residents were included in the study. The study population was diverse in age, gender, and level of education and 70 % reported Mexico as their country of origin. Two items of the English eight-item Short NUMi demonstrated DIF and were dropped. The resulting six-item test had a Cronbach's alpha of 0.72, a range of difficulty using classical test statistics (percent correct: 0.48 to 0.86), and adequate discrimination (item-total score correlation: 0.34-0.49). Scores were positively correlated with print literacy as measured by the S- TOFHLA (r = 0.67; p Spanish NUMi is a reliable and valid measure of important numerical concepts used in communicating health information.

Reliability and Validity of Qualitative and Operational Research Paradigm

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Muhammad Bashir

2008-01-01

Full Text Available Both qualitative and quantitative paradigms try to find the same result; the truth. Qualitative studies are tools used in understanding and describing the world of human experience. Since we maintain our humanity throughout the research process, it is largely impossible to escape the subjective experience, even for the most experienced of researchers. Reliability and Validity are the issue that has been described in great deal by advocates of quantitative researchers. The validity and the norms of rigor that are applied to quantitative research are not entirely applicable to qualitative research. Validity in qualitative research means the extent to which the data is plausible, credible and trustworthy; and thus can be defended when challenged. Reliability and validity remain appropriate concepts for attaining rigor in qualitative research. Qualitative researchers have to salvage responsibility for reliability and validity by implementing verification strategies integral and self-correcting during the conduct of inquiry itself. This ensures the attainment of rigor using strategies inherent within each qualitative design, and moves the responsibility for incorporating and maintaining reliability and validity from external reviewers’ judgments to the investigators themselves. There have different opinions on validity with some suggesting that the concepts of validity is incompatible with qualitative research and should be abandoned while others argue efforts should be made to ensure validity so as to lend credibility to the results. This paper is an attempt to clarify the meaning and use of reliability and validity in the qualitative research paradigm.

Contracting for Competitive Supply Chains under Network Externalities and Demand Uncertainty

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Xiaojing Liu

2016-01-01

Full Text Available Based on network externalities and demand uncertainty environment, supply chain competition model is built; we identify the valid mechanism for the alternative range of profit-sharing contracts and also analyze the effect of product substitutability coefficient and network externalities on the alliance and profit-sharing contract. The results show that the vertical alliance contributes profit improvement to both the manufacturer and the retailer when the impact of network externalities on the product substitutability is not strong. However, vertical alliance will be out of operation when the effect of network externalities on the product substitutability is strong.

Comprehensive Understanding of Ductility Loss Mechanisms in Various Steels with External and Internal Hydrogen

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Takakuwa, Osamu; Yamabe, Junichiro; Matsunaga, Hisao; Furuya, Yoshiyuki; Matsuoka, Saburo

2017-11-01

Hydrogen-induced ductility loss and related fracture morphologies are comprehensively discussed in consideration of the hydrogen distribution in a specimen with external and internal hydrogen by using 300-series austenitic stainless steels (Types 304, 316, 316L), high-strength austenitic stainless steels (HP160, XM-19), precipitation-hardened iron-based super alloy (A286), low-alloy Cr-Mo steel (JIS-SCM435), and low-carbon steel (JIS-SM490B). External hydrogen is realized by a non-charged specimen tested in high-pressure gaseous hydrogen, and internal hydrogen is realized by a hydrogen-charged specimen tested in air or inert gas. Fracture morphologies obtained by slow-strain-rate tensile tests (SSRT) of the materials with external or internal hydrogen could be comprehensively categorized into five types: hydrogen-induced successive crack growth, ordinary void formation, small-sized void formation related to the void sheet, large-sized void formation, and facet formation. The mechanisms of hydrogen embrittlement are broadly classified into hydrogen-enhanced decohesion (HEDE) and hydrogen-enhanced localized plasticity (HELP). In the HEDE model, hydrogen weakens interatomic bonds, whereas in the HELP model, hydrogen enhances localized slip deformations. Although various fracture morphologies are produced by external or internal hydrogen, these morphologies can be explained by the HELP model rather than by the HEDE model.

Understanding Dynamic Model Validation of a Wind Turbine Generator and a Wind Power Plant: Preprint

Energy Technology Data Exchange (ETDEWEB)

Muljadi, Eduard; Zhang, Ying Chen; Gevorgian, Vahan; Kosterev, Dmitry

2016-09-01

Regional reliability organizations require power plants to validate the dynamic models that represent them to ensure that power systems studies are performed to the best representation of the components installed. In the process of validating a wind power plant (WPP), one must be cognizant of the parameter settings of the wind turbine generators (WTGs) and the operational settings of the WPP. Validating the dynamic model of a WPP is required to be performed periodically. This is because the control parameters of the WTGs and the other supporting components within a WPP may be modified to comply with new grid codes or upgrades to the WTG controller with new capabilities developed by the turbine manufacturers or requested by the plant owners or operators. The diversity within a WPP affects the way we represent it in a model. Diversity within a WPP may be found in the way the WTGs are controlled, the wind resource, the layout of the WPP (electrical diversity), and the type of WTGs used. Each group of WTGs constitutes a significant portion of the output power of the WPP, and their unique and salient behaviors should be represented individually. The objective of this paper is to illustrate the process of dynamic model validations of WTGs and WPPs, the available data recorded that must be screened before it is used for the dynamic validations, and the assumptions made in the dynamic models of the WTG and WPP that must be understood. Without understanding the correct process, the validations may lead to the wrong representations of the WTG and WPP modeled.

Protection of Mobile Agents Execution Using a Modified Self-Validating Branch-Based Software Watermarking with External Sentinel

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Tomàs-Buliart, Joan; Fernández, Marcel; Soriano, Miguel

Critical infrastructures are usually controlled by software entities. To monitor the well-function of these entities, a solution based in the use of mobile agents is proposed. Some proposals to detect modifications of mobile agents, as digital signature of code, exist but they are oriented to protect software against modification or to verify that an agent have been executed correctly. The aim of our proposal is to guarantee that the software is being executed correctly by a non trusted host. The way proposed to achieve this objective is by the improvement of the Self-Validating Branch-Based Software Watermarking by Myles et al.. The proposed modification is the incorporation of an external element called sentinel which controls branch targets. This technique applied in mobile agents can guarantee the correct operation of an agent or, at least, can detect suspicious behaviours of a malicious host during the execution of the agent instead of detecting when the execution of the agent have finished.

Greed, grievance, leadership and external interventions in the initiation and intensification of the civil war in Angola

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Ricardo Real P. Sousa

2016-05-01

Full Text Available Understanding the initiation of conflict is fundamental for the success of efforts in conflict prevention. The validity of the mechanisms of the “Greed and Grievance” model, alongside leadership and external interventions are tested in four periods of initiation and intensification of the conflict in Angola. All mechanisms are present but their relative relevance varies throughout the conflict. Among the mechanisms identified in each period the most relevant in the Cold War period are the international and regional interventions in 1961 and 1975 and in the post-Cold War period, the “greed” factors in 1992 (oil and diamonds, poverty and war capital and the UNITA leadership of Jonas Savimbi in 1998. The case study provides evidence that “greed” and “grievance” can be interlinked (such as in 1992 and confirms the relevance of leadership and external interventions mechanisms.

Evolution of external genitalia: insights from reptilian development.

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Gredler, Marissa L; Larkins, Christine E; Leal, Francisca; Lewis, A Kelsey; Herrera, Ana M; Perriton, Claire L; Sanger, Thomas J; Cohn, Martin J

2014-01-01

External genitalia are found in each of the major clades of amniotes. The phallus is an intromittent organ that functions to deliver sperm into the female reproductive tract for internal fertilization. The cellular and molecular genetic mechanisms of external genital development have begun to be elucidated from studies of the mouse genital tubercle, an embryonic appendage adjacent to the cloaca that is the precursor of the penis and clitoris. Progress in this area has improved our understanding of genitourinary malformations, which are among the most common birth defects in humans, and created new opportunities for comparative studies of other taxa. External genitalia evolve rapidly, which has led to a striking diversity of anatomical forms. Within the past year, studies of external genital development in non-mammalian amniotes, including birds, lizards, snakes, alligators, and turtles, have begun to shed light on the molecular and morphogenetic mechanisms underlying the diversification of phallus morphology. Here, we review recent progress in the comparative developmental biology of external genitalia and discuss the implications of this work for understanding external genital evolution. We address the question of the deep homology (shared common ancestry) of genital structures and of developmental mechanisms, and identify new areas of investigation that can be pursued by taking a comparative approach to studying development of the external genitalia. We propose an evolutionary interpretation of hypospadias, a congenital malformation of the urethra, and discuss how investigations of non-mammalian species can provide novel perspectives on human pathologies.

An experimental study of the effect of external thermocouples on rewetting during reflood

International Nuclear Information System (INIS)

Shires, G.L.; Butcher, A.A.; Carpenter, B.G.; McCune, D.S.; Pearson, K.G.

1980-04-01

The validation of computer codes used for PWR safety assessment often depends upon experiments carried out with either real fuel pins or electrically heated fuel pin simulators. In some cases, and this applies particularly to in-pile tests, temperatures are measured by means of sheathed thermocouples attached externally to the pins and this raises the question of the possible effect of such thermocouples on the two phase hydraulics and heat transfer which are being studied. This paper describes the experiments which subjected two realistic fuel pin simulators, one with and one without external thermocouples, to identical bottom flooding conditions. They demonstrate very clearly that external thermocouples act as preferential rewetting sites and thereby increase the rate of propagation of the quench front. In the view of the authors of this paper the facts described raise serious doubts about the validity of rewetting data obtained from experiments employing external thermocouples. (U.K.)

Evaluation of external hazards to nuclear power plants in the United States: Other external events

International Nuclear Information System (INIS)

Kimura, C.Y.; Prassinos, P.G.

1989-02-01

In support of implementation of the Nuclear Regulatory Commission's Severe Accident Policy, the Lawrence Livermore National Laboratory (LLNL) has performed a study of the risk of core damage to nuclear power plants in the United States due to ''other external events.'' The broad objective has been to gain an understanding of whether ''other external events'' (the hazards not covered by previous reports) are among the major potential accident initiators that may pose a threat of severe reactor core damage or of large radioactive release to the environment from the reactor. The ''other external events'' covered in this report are nearby industrial/military facility accidents, on site hazardous material storage accidents, severe temperature transients, severe weather storms, lightning strikes, external fires, extraterrestrial activity, volcanic activity, earth movement, and abrasive windstorms. The analysis was based on two figures-of-merit, one based on core damage frequency and the other based on the frequency of large radioactive releases. 37 refs., 8 tabs

Clinical endpoint adjudication in a contemporary all-comers coronary stent investigation: methodology and external validation.

Science.gov (United States)

Vranckx, Pascal; McFadden, Eugene; Cutlip, Donald E; Mehran, Roxana; Swart, Michael; Kint, P P; Zijlstra, Felix; Silber, Sigmund; Windecker, Stephan; Serruys, Patrick W C J

2013-01-01

Globalisation in coronary stent research calls for harmonization of clinical endpoint definitions and event adjudication. Little has been published about the various processes used for event adjudication or their impact on outcome reporting. We performed a validation of the clinical event committee (CEC) adjudication process on 100 suspected events in the RESOLUTE All-comers trial (Resolute-AC). Two experienced Clinical Research Organisations (CRO) that had already extensive internal validation processes in place, participated in the study. After initial adjudication by the primary-CEC, events were cross-adjudicated by an external-CEC using the same definitions. Major discrepancies affecting the primary end point of target-lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction (TV-MI), or clinically-indicated target-lesion revascularization (CI-TLR), were analysed by an independent oversight committee who provided recommendations for harmonization. Discordant adjudications were reconsidered by the primary CEC. Subsequently, the RAC database was interrogated for cases that based on these recommendations merited re-adjudication and these cases were also re-adjudicated by the primary CEC. Final discrepancies in adjudication of individual components of TLF occurred in 7 out of 100 events in 5 patients. Discrepancies for the (hierarchical) primary endpoint occurred in 5 events (2 cardiac deaths and 3 TV-MI). After application of harmonization recommendations to the overall RAC population (n=2292), the primary CEC adjudicated 3 additional clinical-TLRs and considered 1 TV-MI as no event. A harmonization process provided a high level of concordance for event adjudication and improved accuracy for final event reporting. These findings suggest it is feasible to pool clinical event outcome data across clinical trials even when different CECs are responsible for event adjudication. Copyright © 2012 Elsevier Inc. All rights reserved.

Investigation of thermoelastic stresses induced at high altitudes on aircraft external fuel tanks

Science.gov (United States)

Mousseau, Stephanie Lynn Steber

As composite technology has grown over the past several decades, the use of composite materials in military applications has become more feasible and widely accepted. Although composite materials provide many benefits, including strength optimization and reduced weight, damage and repair of these materials creates an additional challenge, especially when operating in a marine environment, such as on a carrier deck. This is evident within the Navy, as excessive damage often leads to the scrapping of F/A-18 External Fuel Tanks. This damage comes in many forms, the most elusive of which is delamination. Often the delamination found on the tanks is beyond repairable limits and the cause unknown, making it difficult to predict and prevent. The purpose of this investigation was to study the structure of the Navy's 330 gallon External Fuel Tanks and investigate one potential cause of delamination, stresses induced at high altitudes by cold temperatures. A stress analysis was completed using finite element software, and validation of the model was accomplished through testing of a scale model specimen. Due to the difficulties in modeling and predicting delamination, such as unknown presence of voids and understanding failure criteria, delamination was not modeled in Abaqus, rather stresses were observed and characteristics were studied to understand the potential for delamination within the layup. In addition, studies were performed to understand the effect of material properties and layup sequence on the stress distribution within the tank. Alternative design solutions are presented which could reduce the radial stresses within the tank, and recommendations are made for further study to understand the trade-offs between stress, cost, and manufacturability.

Family Violence Pathways and Externalizing Behavior in Youth.

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Bozzay, Melanie L; Joy, Lendi N; Verona, Edelyn

2017-08-01

While studies suggest that youth who experience violence in the home are more likely to engage in externalizing behaviors (e.g., aggression, substance use, rule breaking), research is needed to understand factors that may explain how family violence is linked to externalizing, and whether there may be gender-specific trajectories to this outcome. The present study used a cross-sectional design and multigroup, path analytic modeling to test the degree to which personality traits (negative emotionality, constraint) in boys and girls (Model 1), as well as status offending primarily in girls (Model 2), may help explain relationships between exposure to familial adversity (witnessing family violence and child abuse) and adolescent externalizing behaviors in a mixed-gender, community sample with both caregiver and youth reports ( N = 237, 57% female, 10-17 years old). Results indicated that personality traits fully explained the relationship between witnessing family violence and externalizing and partially explained the relationship between child abuse and externalizing among youth. Despite theory suggesting a female-specific trajectory involving status offenses, both models were similarly relevant for boys and girls. These findings have implications for understanding processes by which adverse family circumstances may relate to externalizing behavior in youth. Preliminary suggestions are provided for future longitudinal research, policy changes, and clinical techniques that may be essential in preventing the progression to long-term adverse outcomes among youth.

Operationalizing Proneness to Externalizing Psychopathology as a Multivariate Psychophysiological Phenotype

Science.gov (United States)

Nelson, Lindsay D.; Patrick, Christopher J.; Bernat, Edward M.

2010-01-01

The externalizing dimension is viewed as a broad dispositional factor underlying risk for numerous disinhibitory disorders. Prior work has documented deficits in event-related brain potential (ERP) responses in individuals prone to externalizing problems. Here, we constructed a direct physiological index of externalizing vulnerability from three ERP indicators and evaluated its validity in relation to criterion measures in two distinct domains: psychometric and physiological. The index was derived from three ERP measures that covaried in their relations with externalizing proneness the error-related negativity and two variants of the P3. Scores on this ERP composite predicted psychometric criterion variables and accounted for externalizing-related variance in P3 response from a separate task. These findings illustrate how a diagnostic construct can be operationalized as a composite (multivariate) psychophysiological variable (phenotype). PMID:20573054

The Interactive Effects of Perceived External Prestige and Need for Organizational Identification on Turnover Intentions

Science.gov (United States)

Mignonac, Karim; Herrbach, Olivier; Guerrero, Sylvie

2006-01-01

Recent research has highlighted the importance of understanding the influence of an organization's external image on its members. Although progress has been made in understanding how perceived external prestige relates to workplace outcomes, researchers have not examined the joint effect of perceived external prestige and individual differences on…

STRUCTURE AND VALIDATION OF A CONTEXTUAL QUALITY OF LIFE SCALE FOR PEOPLE WITH INTELLECTUAL DISABILITIES IN SOCIAL SERVICES: AN ORGANIZATION-ORIENTED MEASURE FROM AN EXTERNAL PERSPECTIVE

Directory of Open Access Journals (Sweden)

Carolina Moliner

2013-09-01

Full Text Available The aim of this study is to develop and validate a scale on the Quality of Life (QoL of people with intellectual disabilities as assessed by family members (external perspective. The instrument measures improvement in QoL due to actions by organizations delivering services to individuals with intellectual disabilities (organization-oriented measure. In order to design the items for the scale, focus groups were set up with professionals dedicated to attending to individuals with intellectual disabilities. An initial scale of 20 items was constructed by consensus. A total of 1195 family members answered the questionnaire. In order to assess the structure of the scale, EFA recommended deleting 3 overlapping items. The final scale consisted of 17 items (α=95 and was composed of four main dimensions: self-determination (SD, social inclusion (SI, rights (RI and overall improvement (OI, which explained 74.83% of the variance. Finally, the consistency and validity were assessed. Convergent validity and discriminant validity were satisfactory. Moreover, CFA confirmed the structure of the scale. Main conclusions, limitations and practical implications are discussed.

External review and validation of the Swedish national inpatient register

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Kim Jeong-Lim

2011-06-01

Full Text Available Abstract Background The Swedish National Inpatient Register (IPR, also called the Hospital Discharge Register, is a principal source of data for numerous research projects. The IPR is part of the National Patient Register. The Swedish IPR was launched in 1964 (psychiatric diagnoses from 1973 but complete coverage did not begin until 1987. Currently, more than 99% of all somatic (including surgery and psychiatric hospital discharges are registered in the IPR. A previous validation of the IPR by the National Board of Health and Welfare showed that 85-95% of all diagnoses in the IPR are valid. The current paper describes the history, structure, coverage and quality of the Swedish IPR. Methods and results In January 2010, we searched the medical databases, Medline and HighWire, using the search algorithm "validat* (inpatient or hospital discharge Sweden". We also contacted 218 members of the Swedish Society of Epidemiology and an additional 201 medical researchers to identify papers that had validated the IPR. In total, 132 papers were reviewed. The positive predictive value (PPV was found to differ between diagnoses in the IPR, but is generally 85-95%. Conclusions In conclusion, the validity of the Swedish IPR is high for many but not all diagnoses. The long follow-up makes the register particularly suitable for large-scale population-based research, but for certain research areas the use of other health registers, such as the Swedish Cancer Register, may be more suitable.

External validation of Vascular Study Group of New England risk predictive model of mortality after elective abdominal aorta aneurysm repair in the Vascular Quality Initiative and comparison against established models.

Science.gov (United States)

Eslami, Mohammad H; Rybin, Denis V; Doros, Gheorghe; Siracuse, Jeffrey J; Farber, Alik

2018-01-01

The purpose of this study is to externally validate a recently reported Vascular Study Group of New England (VSGNE) risk predictive model of postoperative mortality after elective abdominal aortic aneurysm (AAA) repair and to compare its predictive ability across different patients' risk categories and against the established risk predictive models using the Vascular Quality Initiative (VQI) AAA sample. The VQI AAA database (2010-2015) was queried for patients who underwent elective AAA repair. The VSGNE cases were excluded from the VQI sample. The external validation of a recently published VSGNE AAA risk predictive model, which includes only preoperative variables (age, gender, history of coronary artery disease, chronic obstructive pulmonary disease, cerebrovascular disease, creatinine levels, and aneurysm size) and planned type of repair, was performed using the VQI elective AAA repair sample. The predictive value of the model was assessed via the C-statistic. Hosmer-Lemeshow method was used to assess calibration and goodness of fit. This model was then compared with the Medicare, Vascular Governance Northwest model, and Glasgow Aneurysm Score for predicting mortality in VQI sample. The Vuong test was performed to compare the model fit between the models. Model discrimination was assessed in different risk group VQI quintiles. Data from 4431 cases from the VSGNE sample with the overall mortality rate of 1.4% was used to develop the model. The internally validated VSGNE model showed a very high discriminating ability in predicting mortality (C = 0.822) and good model fit (Hosmer-Lemeshow P = .309) among the VSGNE elective AAA repair sample. External validation on 16,989 VQI cases with an overall 0.9% mortality rate showed very robust predictive ability of mortality (C = 0.802). Vuong tests yielded a significant fit difference favoring the VSGNE over then Medicare model (C = 0.780), Vascular Governance Northwest (0.774), and Glasgow Aneurysm Score (0

Modeling and simulation of maintenance treatment in first-line non-small cell lung cancer with external validation

International Nuclear Information System (INIS)

Han, Kelong; Claret, Laurent; Sandler, Alan; Das, Asha; Jin, Jin; Bruno, Rene

2016-01-01

Maintenance treatment (MTx) in responders following first-line treatment has been investigated and practiced for many cancers. Modeling and simulation may support interpretation of interim data and development decisions. We aimed to develop a modeling framework to simulate overall survival (OS) for MTx in NSCLC using tumor growth inhibition (TGI) data. TGI metrics were estimated using longitudinal tumor size data from two Phase III first-line NSCLC studies evaluating bevacizumab and erlotinib as MTx in 1632 patients. Baseline prognostic factors and TGI metric estimates were assessed in multivariate parametric models to predict OS. The OS model was externally validated by simulating a third independent NSCLC study (n = 253) based on interim TGI data (up to progression-free survival database lock). The third study evaluated pemetrexed + bevacizumab vs. bevacizumab alone as MTx. Time-to-tumor-growth (TTG) was the best TGI metric to predict OS. TTG, baseline tumor size, ECOG score, Asian ethnicity, age, and gender were significant covariates in the final OS model. The OS model was qualified by simulating OS distributions and hazard ratios (HR) in the two studies used for model-building. Simulations of the third independent study based on interim TGI data showed that pemetrexed + bevacizumab MTx was unlikely to significantly prolong OS vs. bevacizumab alone given the current sample size (predicted HR: 0.81; 95 % prediction interval: 0.59–1.09). Predicted median OS was 17.3 months and 14.7 months in both arms, respectively. These simulations are consistent with the results of the final OS analysis published 2 years later (observed HR: 0.87; 95 % confidence interval: 0.63–1.21). Final observed median OS was 17.1 months and 13.2 months in both arms, respectively, consistent with our predictions. A robust TGI-OS model was developed for MTx in NSCLC. TTG captures treatment effect. The model successfully predicted the OS outcomes of an independent study based on interim

Modeling and simulation of maintenance treatment in first-line non-small cell lung cancer with external validation.

Science.gov (United States)

Han, Kelong; Claret, Laurent; Sandler, Alan; Das, Asha; Jin, Jin; Bruno, Rene

2016-07-13

Maintenance treatment (MTx) in responders following first-line treatment has been investigated and practiced for many cancers. Modeling and simulation may support interpretation of interim data and development decisions. We aimed to develop a modeling framework to simulate overall survival (OS) for MTx in NSCLC using tumor growth inhibition (TGI) data. TGI metrics were estimated using longitudinal tumor size data from two Phase III first-line NSCLC studies evaluating bevacizumab and erlotinib as MTx in 1632 patients. Baseline prognostic factors and TGI metric estimates were assessed in multivariate parametric models to predict OS. The OS model was externally validated by simulating a third independent NSCLC study (n = 253) based on interim TGI data (up to progression-free survival database lock). The third study evaluated pemetrexed + bevacizumab vs. bevacizumab alone as MTx. Time-to-tumor-growth (TTG) was the best TGI metric to predict OS. TTG, baseline tumor size, ECOG score, Asian ethnicity, age, and gender were significant covariates in the final OS model. The OS model was qualified by simulating OS distributions and hazard ratios (HR) in the two studies used for model-building. Simulations of the third independent study based on interim TGI data showed that pemetrexed + bevacizumab MTx was unlikely to significantly prolong OS vs. bevacizumab alone given the current sample size (predicted HR: 0.81; 95 % prediction interval: 0.59-1.09). Predicted median OS was 17.3 months and 14.7 months in both arms, respectively. These simulations are consistent with the results of the final OS analysis published 2 years later (observed HR: 0.87; 95 % confidence interval: 0.63-1.21). Final observed median OS was 17.1 months and 13.2 months in both arms, respectively, consistent with our predictions. A robust TGI-OS model was developed for MTx in NSCLC. TTG captures treatment effect. The model successfully predicted the OS outcomes of an independent study

Validation of a questionnaire to measure sexual health knowledge and understanding (Sexual Health Questionnaire) in Nepalese secondary school: A psychometric process.

Science.gov (United States)

Acharya, Dev Raj; Thomas, Malcolm; Cann, Rosemary

2016-01-01

School-based sex education has the potential to prevent unwanted pregnancy and to promote positive sexual health at the individual, family and community level. To develop and validate a sexual health questionnaire to measure young peoples' sexual health knowledge and understanding (SHQ) in Nepalese secondary school. Secondary school students (n = 259, male = 43.63%, female = 56.37%) and local experts (n = 9, male = 90%, female = 10%) were participated in this study. Evaluation processes were; content validity (>0.89), plausibility check (>95), item-total correlation (>0.3), factor loading (>0.4), principal component analysis (4 factors Kaiser's criterion), Chronbach's alpha (>0.65), face validity and internal consistency using test-retest reliability (P > 0.05). The principal component analysis revealed four factors to be extracted; sexual health norms and beliefs, source of sexual health information, sexual health knowledge and understanding, and level of sexual awareness. Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy demonstrated that the patterns of correlations are relatively compact (>0.80). Chronbach's alpha for each factors were above the cut-off point (0.65). Face validity indicated that the questions were clear to the majority of the respondent. Moreover, there were no significant differences (P > 0.05) in the responses to the items at two time points at seven weeks later. The finding suggests that SHQ is a valid and reliable instrument to be used in schools to measure sexual health knowledge and understanding. Further analysis such as structured equation modelling (SEM) and confirmatory factor analysis could make the questionnaire more robust and applicable to the wider school population.

External Validation of Fatty Liver Index for Identifying Ultrasonographic Fatty Liver in a Large-Scale Cross-Sectional Study in Taiwan

Science.gov (United States)

Fang, Kuan-Chieh; Wang, Yuan-Chen; Huo, Teh-Ia; Huang, Yi-Hsiang; Yang, Hwai-I; Su, Chien-Wei; Lin, Han-Chieh; Lee, Fa-Yauh; Wu, Jaw-Ching; Lee, Shou-Dong

2015-01-01

Background and Aims The fatty liver index (FLI) is an algorithm involving the waist circumference, body mass index, and serum levels of triglyceride and gamma-glutamyl transferase to identify fatty liver. Although some studies have attempted to validate the FLI, few studies have been conducted for external validation among Asians. We attempted to validate FLI to predict ultrasonographic fatty liver in Taiwanese subjects. Methods We enrolled consecutive subjects who received health check-up services at the Taipei Veterans General Hospital from 2002 to 2009. Ultrasonography was applied to diagnose fatty liver. The ability of the FLI to detect ultrasonographic fatty liver was assessed by analyzing the area under the receiver operating characteristic (AUROC) curve. Results Among the 29,797 subjects enrolled in this study, fatty liver was diagnosed in 44.5% of the population. Subjects with ultrasonographic fatty liver had a significantly higher FLI than those without fatty liver by multivariate analysis (odds ratio 1.045; 95% confidence interval, CI 1.044–1.047, pfatty liver (AUROC: 0.827, 95% confidence interval, 0.822–0.831). An FLI fatty liver. Moreover, an FLI ≥ 35 (positive likelihood ratio (LR+) 3.12) for males and ≥ 20 (LR+ 4.43) for females rule in ultrasonographic fatty liver. Conclusions FLI could accurately identify ultrasonographic fatty liver in a large-scale population in Taiwan but with lower cut-off value than the Western population. Meanwhile the cut-off value was lower in females than in males. PMID:25781622

Fundamentals of critical analysis: the concept of validity and analysis essentials

Directory of Open Access Journals (Sweden)

Miguel Araujo Alonso

2012-01-01

Full Text Available Critical analysis of literature is an assessment process that allows the reader to get an idea of potential error in the results of a study, errors arising either from bias or confusion. Critical analysis attempts to establish whether the study meets expected criteria or methodological conditions. There are many checklists available that are commonly used to guide this analysis, but filling out a checklist is not tantamount to critical appraisal. Internal validity is defined as the extent to which a research finding actually represents the true relationship between exposure and outcome, considering the unique conditions in which the study was carried out. Attention must be given to the inclusion and exclusion criteria that were used, on the sampling methods, on the baseline characteristics of the patients that were enrolled in the study. External validity refers to the possibility of generalizing conclusions beyond the study sample or the study population. External validity includes population validity and ecological validity. Lastly, the article covers potential threats to external validity that must be considered when analyzing a study.

Bursting pressure of autofrettaged cylinders with inclined external cracks

International Nuclear Information System (INIS)

Seifi, Rahman; Babalhavaeji, Majid

2012-01-01

Autofrettaging a pressure vessel improves its pressure capacity. This is reliable if there isn’t any crack or other type of flaws. In this paper, the effects of external surface cracks on bursting pressure of autofrettaged cylinders are studied. It is observed that bursting pressure decreases considerably (up to 30%) due to external cracks in the cylinders without autofrettage. This reduction increases for high levels of the applied autofrettage. External axial cracks have more effects than inclined cracks. Comparing experimental and numerical results show that the numerical methods can acceptably predict the bursting pressure of the autofrettaged cracked cylinders. These predictions are valid when the fracture parameter (J-Integral) is calculated from the modified equation that takes into account the effects of residual stresses. - Highlights: ► Modified J-Integral can be used for study of autofrettaged cracked cylinders. ► External axial cracks reduce considerably the pressure capacity of cylinders. ► External circumferential cracks have not considerable effects on bursting pressure. ► Autofrettage has contrary effects on external crack in compared with internal crack.

An Exploration of the Validity and Potential of Adult Ego Development for Enhancing Understandings of School Leadership

Science.gov (United States)

James, Chris; James, Jane; Potter, Ian

2017-01-01

An adult ego development (AED) perspective accepts that the way adults interpret and interact in the social world can change during their life-span. This article seeks to analyse the validity and potential of AED for enhancing understandings of educational leadership practice and development. We analysed the AED literature and interviewed 16…

External Correlates of the MMPI-2 Content Component Scales in Mental Health Inpatients

Science.gov (United States)

Green, Bradley A.; Handel, Richard W.; Archer, Robert P.

2006-01-01

External correlates of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Content Component Scales were identified using an inpatient sample of 544 adults. The Brief Psychiatric Rating Scale (BPRS) and Symptom Checklist 90-Revised (SCL-90-R) produced correlates of the Content Component Scales, demonstrating external validity with…

ExternE transport methodology for external cost evaluation of air pollution

DEFF Research Database (Denmark)

Jensen, S. S.; Berkowicz, R.; Brandt, J.

The report describes how the human exposure estimates based on NERI's human exposure modelling system (AirGIS) can improve the Danish data used for exposure factors in the ExternE Transport methodology. Initially, a brief description of the ExternE Tranport methodology is given and it is summarised...

The bottom-up approach to integrative validity: a new perspective for program evaluation.

Science.gov (United States)

Chen, Huey T

2010-08-01

The Campbellian validity model and the traditional top-down approach to validity have had a profound influence on research and evaluation. That model includes the concepts of internal and external validity and within that model, the preeminence of internal validity as demonstrated in the top-down approach. Evaluators and researchers have, however, increasingly recognized that in an evaluation, the over-emphasis on internal validity reduces that evaluation's usefulness and contributes to the gulf between academic and practical communities regarding interventions. This article examines the limitations of the Campbellian validity model and the top-down approach and provides a comprehensive, alternative model, known as the integrative validity model for program evaluation. The integrative validity model includes the concept of viable validity, which is predicated on a bottom-up approach to validity. This approach better reflects stakeholders' evaluation views and concerns, makes external validity workable, and becomes therefore a preferable alternative for evaluation of health promotion/social betterment programs. The integrative validity model and the bottom-up approach enable evaluators to meet scientific and practical requirements, facilitate in advancing external validity, and gain a new perspective on methods. The new perspective also furnishes a balanced view of credible evidence, and offers an alternative perspective for funding. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

External validity of randomized controlled trials in older adults, a systematic review.

Directory of Open Access Journals (Sweden)

Floor J van Deudekom

Full Text Available To critically assess the external validity of randomized controlled trials (RCTs it is important to know what older adults have been enrolled in the trials. The aim of this systematic review is to study what proportion of trials specifically designed for older patients report on somatic status, physical and mental functioning, social environment and frailty in the patient characteristics.PubMed was searched for articles published in 2012 and only RCTs were included. Articles were further excluded if not conducted with humans or only secondary analyses were reported. A random sample of 10% was drawn. The current review analyzed this random sample and further selected trials when the reported mean age was ≥ 60 years. We extracted geriatric assessments from the population descriptives or the in- and exclusion criteria.In total 1396 trials were analyzed and 300 trials included. The median of the reported mean age was 66 (IQR 63-70 and the median percentage of men in the trials was 60 (IQR 45-72. In 34% of the RCTs specifically designed for older patients somatic status, physical and mental functioning, social environment or frailty were reported in the population descriptives or the in- and exclusion criteria. Physical and mental functioning was reported most frequently (22% and 14%. When selecting RCTs on a mean age of 70 or 80 years the report of geriatric assessments in the patient characteristics was 46% and 85% respectively but represent only 5% and 1% of the trials.Somatic status, physical and mental functioning, social environment and frailty are underreported even in RCTs specifically designed for older patients published in 2012. Therefore, it is unclear for clinicians to which older patients the results can be applied. We recommend systematic to transparently report these relevant characteristics of older participants included in RCTs.

Development, validation, and implementation of a questionnaire assessing disease knowledge and understanding in adult cystic fibrosis patients.

LENUS (Irish Health Repository)

Siklosi, Karen R

2012-02-01

BACKGROUND: The number of adults living with cystic fibrosis (CF) is increasing, necessitating an assessment of knowledge in this growing population. METHODS: A questionnaire assessing CF knowledge was completed by 100 CF patients (median age: 26.0 years, range 17-49 years; median FEV: 57.0% predicted, range 20-127% predicted). Level of knowledge was correlated with clinical and sociodemographic characteristics. RESULTS: Questionnaire validation showed acceptable internal consistency (alpha=0.75) and test-retest reliability (0.94). Patients had fair overall understanding of CF (mean=72.4%, SD=13.1), with greater knowledge of lung and gastrointestinal topics (mean=81.6%, SD=11.6) than reproduction and genetics topics (mean=57.9%, SD=24.1). Females and those with post-secondary education scored significantly higher (p<0.05). CONCLUSIONS: This study validated a questionnaire that can be utilized to assess CF knowledge. Although CF patients understand most aspects of their disease, knowledge deficits are common - particularly regarding genetics and reproduction - and should be considered when developing CF education programs.

External validation of EPIWIN biodegradation models.

Science.gov (United States)

Posthumus, R; Traas, T P; Peijnenburg, W J G M; Hulzebos, E M

2005-01-01

The BIOWIN biodegradation models were evaluated for their suitability for regulatory purposes. BIOWIN includes the linear and non-linear BIODEG and MITI models for estimating the probability of rapid aerobic biodegradation and an expert survey model for primary and ultimate biodegradation estimation. Experimental biodegradation data for 110 newly notified substances were compared with the estimations of the different models. The models were applied separately and in combinations to determine which model(s) showed the best performance. The results of this study were compared with the results of other validation studies and other biodegradation models. The BIOWIN models predict not-readily biodegradable substances with high accuracy in contrast to ready biodegradability. In view of the high environmental concern of persistent chemicals and in view of the large number of not-readily biodegradable chemicals compared to the readily ones, a model is preferred that gives a minimum of false positives without a corresponding high percentage false negatives. A combination of the BIOWIN models (BIOWIN2 or BIOWIN6) showed the highest predictive value for not-readily biodegradability. However, the highest score for overall predictivity with lowest percentage false predictions was achieved by applying BIOWIN3 (pass level 2.75) and BIOWIN6.

Developmental Pathways for Social Understanding: Linking Social Cognition to Social Contexts

Directory of Open Access Journals (Sweden)

Kimberly eBrink

2015-05-01

Full Text Available Contemporary research, often with looking-time tasks, reveals that infants possess foundational understandings of their social worlds. However, few studies have examined how these early social cognitions relate to the child’s social interactions and behavior in early development. Does an early understanding of the social world relate to how an infant interacts with his or her parents? Do early social interactions along with social-cognitive understandings in infancy predict later preschool social competencies? In the current paper, we propose a theory in which children’s later social behaviors and their understanding of the social world depend on the integration of early social understanding and experiences in infancy. We review several of our studies, as well as other research, that directly examine the pathways between these competencies to support a hypothesized network of relations between social-cognitive development and social-interactive behaviors in the development from infancy to childhood. In total, these findings reveal differences in infant social competences that both track the developmental trajectory of infants’ understanding of people over the first years of life and provide external validation for the large body of social-cognitive findings emerging from laboratory looking-time paradigms.

External validation of the Intensive Care National Audit & Research Centre (ICNARC) risk prediction model in critical care units in Scotland.

Science.gov (United States)

Harrison, David A; Lone, Nazir I; Haddow, Catriona; MacGillivray, Moranne; Khan, Angela; Cook, Brian; Rowan, Kathryn M

2014-01-01

Risk prediction models are used in critical care for risk stratification, summarising and communicating risk, supporting clinical decision-making and benchmarking performance. However, they require validation before they can be used with confidence, ideally using independently collected data from a different source to that used to develop the model. The aim of this study was to validate the Intensive Care National Audit & Research Centre (ICNARC) model using independently collected data from critical care units in Scotland. Data were extracted from the Scottish Intensive Care Society Audit Group (SICSAG) database for the years 2007 to 2009. Recoding and mapping of variables was performed, as required, to apply the ICNARC model (2009 recalibration) to the SICSAG data using standard computer algorithms. The performance of the ICNARC model was assessed for discrimination, calibration and overall fit and compared with that of the Acute Physiology And Chronic Health Evaluation (APACHE) II model. There were 29,626 admissions to 24 adult, general critical care units in Scotland between 1 January 2007 and 31 December 2009. After exclusions, 23,269 admissions were included in the analysis. The ICNARC model outperformed APACHE II on measures of discrimination (c index 0.848 versus 0.806), calibration (Hosmer-Lemeshow chi-squared statistic 18.8 versus 214) and overall fit (Brier's score 0.140 versus 0.157; Shapiro's R 0.652 versus 0.621). Model performance was consistent across the three years studied. The ICNARC model performed well when validated in an external population to that in which it was developed, using independently collected data.

Development of a reliable, valid measure to assess parents' and teachers' understanding of postural care for children with physical disabilities: the (UKC PostCarD) questionnaire.

Science.gov (United States)

Hotham, S; Hutton, E; Hamilton-West, K E

2015-11-01

Previous research has highlighted lack of knowledge, understanding and confidence among parents and teachers responsible for the postural care of children with physical disability. Interventions designed to improve these qualities require a reliable and validated tool to assess pre- and post-intervention levels. Currently, however, no validated measure of postural care confidence (i.e. self-efficacy) exists. Hence, the aim of this research was to develop a reliable and valid questionnaire to assess parents' and teachers' confidence, alongside knowledge and understanding of postural care - the Understanding Knowledge and Confidence in providing POSTural CARe for children with Disabilities (UKC PostCarD) questionnaire. Items were developed by a multidisciplinary team and designed to map onto the content of 'An A-to-Z of Postural Care'. Parents, teachers and therapists assessed items for face validity. Scale reliability was then assessed using Cronbach's alpha and known-group validity was assessed by comparing scores of an 'expert' group (physiotherapists and occupational therapists) with those of a 'non-expert' group (with no formal training in postural care). The total scale and all three subscales (understanding and knowledge, confidence and concerns) demonstrated adequate reliability (α > 0.83) and subscale correlations formed a logical pattern (understanding and knowledge correlated positively with confidence and negatively with concerns). Experts' (n = 111) scores were higher than non-experts' (n = 79) for the total scale and all subscales (P children with disabilities. © 2015 John Wiley & Sons Ltd.

Children's emotion understanding: A meta-analysis of training studies.

Science.gov (United States)

Sprung, Manuel; Münch, Hannah M; Harris, Paul L; Ebesutani, Chad; Hofmann, Stefan G

2015-09-01

In the course of development, children show increased insight and understanding of emotions-both of their own emotions and those of others. However, little is known about the efficacy of training programs aimed at improving children's understanding of emotion. To conduct an effect size analysis of trainings aimed at three aspects of emotion understanding: external aspects (i.e., the recognition of emotional expressions, understanding external causes of emotion, understanding the influence of reminders on present emotions); mental aspects (i.e., understanding desire-based emotions, understanding belief-based emotions, understanding hidden emotions); and reflective aspects (i.e., understanding the regulation of an emotion, understanding mixed emotions, understanding moral emotions). A literature search was conducted using PubMed, PsycInfo, the Cochrane Library, and manual searches. The search identified 19 studies or experiments including a total of 749 children with an average age of 86 months ( S.D .=30.71) from seven different countries. Emotion understanding training procedures are effective for improving external (Hedge's g = 0.62), mental (Hedge's g = 0.31), and reflective (Hedge's g = 0.64) aspects of emotion understanding. These effect sizes were robust and generally unrelated to the number and lengths of training sessions, length of the training period, year of publication, and sample type. However, training setting and social setting moderated the effect of emotion understanding training on the understanding of external aspects of emotion. For the length of training session and social setting, we observed significant moderator effects of training on reflective aspects of emotion. Emotion understanding training may be a promising tool for both preventive intervention and the psychotherapeutic process. However, more well-controlled studies are needed.

Bursting pressure of autofrettaged cylinders with inclined external cracks

Energy Technology Data Exchange (ETDEWEB)

Seifi, Rahman, E-mail: rseifi@basu.ac.ir [Mechanical Engineering Department, Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Babalhavaeji, Majid [Mechanical Engineering Department, Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)

2012-01-15

Autofrettaging a pressure vessel improves its pressure capacity. This is reliable if there isn't any crack or other type of flaws. In this paper, the effects of external surface cracks on bursting pressure of autofrettaged cylinders are studied. It is observed that bursting pressure decreases considerably (up to 30%) due to external cracks in the cylinders without autofrettage. This reduction increases for high levels of the applied autofrettage. External axial cracks have more effects than inclined cracks. Comparing experimental and numerical results show that the numerical methods can acceptably predict the bursting pressure of the autofrettaged cracked cylinders. These predictions are valid when the fracture parameter (J-Integral) is calculated from the modified equation that takes into account the effects of residual stresses. - Highlights: Black-Right-Pointing-Pointer Modified J-Integral can be used for study of autofrettaged cracked cylinders. Black-Right-Pointing-Pointer External axial cracks reduce considerably the pressure capacity of cylinders. Black-Right-Pointing-Pointer External circumferential cracks have not considerable effects on bursting pressure. Black-Right-Pointing-Pointer Autofrettage has contrary effects on external crack in compared with internal crack.

Predictors of outcome after elective endovascular abdominal aortic aneurysm repair and external validation of a risk prediction model.

Science.gov (United States)

Wisniowski, Brendan; Barnes, Mary; Jenkins, Jason; Boyne, Nicholas; Kruger, Allan; Walker, Philip J

2011-09-01

Endovascular abdominal aortic aneurysm (AAA) repair (EVAR) has been associated with lower operative mortality and morbidity than open surgery but comparable long-term mortality and higher delayed complication and reintervention rates. Attention has therefore been directed to identifying preoperative and operative variables that influence outcomes after EVAR. Risk-prediction models, such as the EVAR Risk Assessment (ERA) model, have also been developed to help surgeons plan EVAR procedures. The aims of this study were (1) to describe outcomes of elective EVAR at the Royal Brisbane and Women's Hospital (RBWH), (2) to identify preoperative and operative variables predictive of outcomes after EVAR, and (3) to externally validate the ERA model. All elective EVAR procedures at the RBWH before July 1, 2009, were reviewed. Descriptive analyses were performed to determine the outcomes. Univariate and multivariate analyses were performed to identify preoperative and operative variables predictive of outcomes after EVAR. Binomial logistic regression analyses were used to externally validate the ERA model. Before July 1, 2009, 197 patients (172 men), who were a mean age of 72.8 years, underwent elective EVAR at the RBWH. Operative mortality was 1.0%. Survival was 81.1% at 3 years and 63.2% at 5 years. Multivariate analysis showed predictors of survival were age (P = .0126), American Society of Anesthesiologists (ASA) score (P = .0180), and chronic obstructive pulmonary disease (P = .0348) at 3 years and age (P = .0103), ASA score (P = .0006), renal failure (P = .0048), and serum creatinine (P = .0022) at 5 years. Aortic branch vessel score was predictive of initial (30-day) type II endoleak (P = .0015). AAA tortuosity was predictive of midterm type I endoleak (P = .0251). Female sex was associated with lower rates of initial clinical success (P = .0406). The ERA model fitted RBWH data well for early death (C statistic = .906), 3-year survival (C statistic = .735), 5-year

Externalities of energy. Swedish implementation of the ExternE methodology

International Nuclear Information System (INIS)

Nilsson, Maans; Gullberg, M.

1998-01-01

The growing interest for developing economic instruments for efficient environmental policies has opened up a large area of multi-disciplinary research. ExternE is an example of this research, combining disciplines such as engineering, ecology, immunology and economics expertise to create new knowledge about how environmental pressures from energy production affect our nature and society. The ExternE Project aims to identify and, as far as possible quantify the externalities of energy production in Europe. The Stockholm Environment Institute has carried out a preliminary aggregation: -Coal Fuel Cycle: centred around Vaesteraas Kraftvaermeverk, Vaesteraas. This is the largest co-generation plant in Sweden, with four blocks and a maximum co-generation output of 520 MW electricity and 950 MW heat. The analysis is carried out on boiler B4. -Biomass Fuel Cycle: centred around Haendeloeverket, Norrkoeping. This plant predominately burns forestry residues, but a variety of fuels are combusted. Haendeloeverket has an installed capacity of 100 MW electricity and 375 MW heat, in a total of three boilers and two back-pressure turbines. The analysis is carried out on boiler P13. -Hydro Fuel Cycle: Klippens Kraftstation, Storuman. Built in 1990-1994, it is the youngest hydro power station in Sweden. It has been designed and built with significant efforts to account for and protect environmental values. Installed capacity is 28 MW. The environmental impact assessment from the construction of this plant is carried out, but the evaluation is still not finalized. The preliminary aggregation aimed to test whether ExternE results could be used to make estimates for the entire Swedish electricity production system. Hence, national results as well as results from other partner countries in ExternE has been applied

Testing the role of external debt in environmental degradation: empirical evidence from Turkey.

Science.gov (United States)

Katircioglu, Salih; Celebi, Aysem

2018-03-01

This study investigates the role of external debt stock in Turkey, which has suffered from heavy (external and domestic) debt stock for many years. Annual data from 1960 to 2013 was analyzed using time series analysis in order to study this. The results confirm the validity of the conventional environmental Kuznets curve (EKC) in the case of Turkey. However, this study also found that Turkey's external debt stock did not influence the Turkish economy's long-term EKC behavior. Fortunately, the results suggest that there are important interactions among external debt stock, CO 2 emissions, energy consumption, and real income; that is, changes in external debt volume precede changes in these aggregates' volumes.

The Development and Validation of an Alternative Assessment to Measure Changes in Understanding of the Longleaf Pine Ecosystem

Science.gov (United States)

Dentzau, Michael W.; Martínez, Alejandro José Gallard

2016-01-01

A drawing assessment to gauge changes in fourth grade students' understanding of the essential components of the longleaf pine ecosystem was developed to support an out-of-school environmental education program. Pre- and post-attendance drawings were scored with a rubric that was determined to have content validity and reliability among users. In…

Quantifying external focus of attention in sailing by means of action sport cameras

NARCIS (Netherlands)

Pluijms, Joost; Canal Bruland, R.; Hoozemans, M.J.M.; Beek, M.; Brocker, K.; Savelsbergh, G.J.P.

2016-01-01

The aim of the current study was twofold: (1) to validate the use of action sport cameras for quantifying focus of visual attention in sailing and (2) to apply this method to examine whether an external focus of attention is associated with better performance in upwind sailing. To test the validity

EO Model for Tacit Knowledge Externalization in Socio-Technical Enterprises

Directory of Open Access Journals (Sweden)

Shreyas Suresh Rao

2017-03-01

Full Text Available Aim/Purpose: A vital business activity within socio-technical enterprises is tacit knowledge externalization, which elicits and explicates tacit knowledge of enterprise employees as external knowledge. The aim of this paper is to integrate diverse aspects of externalization through the Enterprise Ontology model. Background: Across two decades, researchers have explored various aspects of tacit knowledge externalization. However, from the existing works, it is revealed that there is no uniform representation of the externalization process, which has resulted in divergent and contradictory interpretations across the literature. Methodology\t: The Enterprise Ontology model is constructed step-wise through the conceptual and measurement views. While the conceptual view encompasses three patterns that model the externalization process, the measurement view employs certainty-factor model to empirically measure the outcome of the externalization process. Contribution: The paper contributes towards knowledge management literature in two ways. The first contribution is the Enterprise Ontology model that integrates diverse aspects of externalization. The second contribution is a Web application that validates the model through a case study in banking. Findings: The findings show that the Enterprise Ontology model and the patterns are pragmatic in externalizing the tacit knowledge of experts in a problem-solving scenario within a banking enterprise. Recommendations for Practitioners\t: Consider the diverse aspects (what, where, when, why, and how during the tacit knowledge externalization process. Future Research:\tTo extend the Enterprise Ontology model to include externalization from partially automated enterprise systems.

Efficacy and External Validity of Electronic and Mobile Phone-Based Interventions Promoting Vegetable Intake in Young Adults: A Systematic Review Protocol.

Science.gov (United States)

Nour, Monica Marina; Chen, Juliana; Allman-Farinelli, Margaret

2015-07-28

Despite social marketing campaigns and behavior change interventions, young adults remain among the lowest consumers of vegetables. The digital era offers potential new avenues for both social marketing and individually tailored programs, through texting, web, and mobile applications. The effectiveness and generalizability of such programs have not been well documented. The aim of this systematic review is to evaluate the efficacy and external validity of social marketing, electronic, and mobile phone-based (mHealth) interventions aimed at increasing vegetable intake in young adults. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol will be used to conduct this systematic review. The search strategy will be executed across eleven electronic databases using combinations of the following search terms: "online intervention", "computer-assisted therapy", "internet", "website", "cell phones", "cyber", "telemedicine", "email", "social marketing", "social media", "mass media", "young adult", and "fruit and vegetables". The reference lists of included studies will also be searched for additional citations. Titles and abstracts will be screened against inclusion criteria and full texts of potentially eligible papers will be assessed by two independent reviewers. Data from eligible papers will be extracted. Quality and risk of bias will be assessed using the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies and The Cochrane Collaboration Risk of Bias assessment tool respectively. The external validity of the studies will be determined based on components such as reach, adoption, and representativeness of participants; intervention implementation and adaption; and program maintenance and institutionalization. Results will be reported quantitatively and qualitatively. Our research is in progress. A draft of the systematic review is currently being produced for publication by the end of 2015

Environmental external effects from wind power based on the EU ExternE methodology

DEFF Research Database (Denmark)

Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

1998-01-01

of the Danish part of the project is to implement the framework for externality evaluation, for three different power plants located in Denmark. The paper will focus on the assessment of the impacts of the whole fuel cycles for wind, natural gas and biogas. Priority areas for environmental impact assessment......The European Commission has launched a major study project, ExternE, to develop a methodology to quantify externalities. A “National Implementation Phase”, was started under the Joule II programme with the purpose of implementing the ExternE methodology in all member states. The main objective...

ExternE National Implementation Finland

Energy Technology Data Exchange (ETDEWEB)

Pingoud, K; Maelkki, H; Wihersaari, M; Pirilae, P [VTT Energy, Espoo (Finland); Hongisto, M [Imatran Voima Oy, Vantaa (Finland); Siitonen, S [Ekono Energy Ltd, Espoo (Finland); Johansson, M [Finnish Environment Institute, Helsinki (Finland)

1999-07-01

ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

ExternE National Implementation Finland

Energy Technology Data Exchange (ETDEWEB)

Pingoud, K.; Maelkki, H.; Wihersaari, M.; Pirilae, P. [VTT Energy, Espoo (Finland); Hongisto, M. [Imatran Voima Oy, Vantaa (Finland); Siitonen, S. [Ekono Energy Ltd, Espoo (Finland); Johansson, M. [Finnish Environment Institute, Helsinki (Finland)

1999-07-01

ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

ExternE National Implementation Finland

International Nuclear Information System (INIS)

Pingoud, K.; Maelkki, H.; Wihersaari, M.; Pirilae, P.; Hongisto, M.; Siitonen, S.; Johansson, M.

1999-01-01

ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

External validation of fatty liver index for identifying ultrasonographic fatty liver in a large-scale cross-sectional study in Taiwan.

Directory of Open Access Journals (Sweden)

Bi-Ling Yang

Full Text Available The fatty liver index (FLI is an algorithm involving the waist circumference, body mass index, and serum levels of triglyceride and gamma-glutamyl transferase to identify fatty liver. Although some studies have attempted to validate the FLI, few studies have been conducted for external validation among Asians. We attempted to validate FLI to predict ultrasonographic fatty liver in Taiwanese subjects.We enrolled consecutive subjects who received health check-up services at the Taipei Veterans General Hospital from 2002 to 2009. Ultrasonography was applied to diagnose fatty liver. The ability of the FLI to detect ultrasonographic fatty liver was assessed by analyzing the area under the receiver operating characteristic (AUROC curve.Among the 29,797 subjects enrolled in this study, fatty liver was diagnosed in 44.5% of the population. Subjects with ultrasonographic fatty liver had a significantly higher FLI than those without fatty liver by multivariate analysis (odds ratio 1.045; 95% confidence interval, CI 1.044-1.047, p< 0.001. Moreover, FLI had the best discriminative ability to identify patients with ultrasonographic fatty liver (AUROC: 0.827, 95% confidence interval, 0.822-0.831. An FLI < 25 (negative likelihood ratio (LR- 0.32 for males and <10 (LR- 0.26 for females rule out ultrasonographic fatty liver. Moreover, an FLI ≥ 35 (positive likelihood ratio (LR+ 3.12 for males and ≥ 20 (LR+ 4.43 for females rule in ultrasonographic fatty liver.FLI could accurately identify ultrasonographic fatty liver in a large-scale population in Taiwan but with lower cut-off value than the Western population. Meanwhile the cut-off value was lower in females than in males.

Regional Externalities

NARCIS (Netherlands)

Heijman, W.J.M.

2007-01-01

The book offers practical and theoretical insights in regional externalities. Regional externalities are a specific subset of externalities that can be defined as externalities where space plays a dominant role. This class of externalities can be divided into three categories: (1) externalities

External non-white noise and nonequilibrium phase transitions

International Nuclear Information System (INIS)

Sancho, J.M.; San Miguel, M.

1980-01-01

Langevin equations with external non-white noise are considered. A Fokker Planck equation valid in general in first order of the correlation time tau of the noise is derived. In some cases its validity can be extended to any value of tau. The effect of a finite tau in the nonequilibrium phase transitions induced by the noise is analyzed, by means of such Fokker Planck equation, in general, for the Verhulst equation under two different kind of fluctuations, and for a genetic model. It is shown that new transitions can appear and that the threshold value of the parameter can be changed. (orig.)

Externalities - an analysis using the EU ExternE-results

International Nuclear Information System (INIS)

2003-10-01

The EU project ExternE quantified the externalities for the different energy technologies. In this work, the ExternE results are used in a MARKAL-analysis for the Nordic countries. The analysis does not go into detail, but gives some interesting indications: The external costs are not fully covered in the Nordic energy systems, the present taxes and charges are not high enough. The emissions from the energy systems would be strongly reduced, if taxes/environmental charges were set at the level ExternE calculate. The emissions from power production would be reduced most. Renewable energy sources and natural gas dominate the energy systems in the ExternE case

External validation of the DHAKA score and comparison with the current IMCI algorithm for the assessment of dehydration in children with diarrhoea: a prospective cohort study.

Science.gov (United States)

Levine, Adam C; Glavis-Bloom, Justin; Modi, Payal; Nasrin, Sabiha; Atika, Bita; Rege, Soham; Robertson, Sarah; Schmid, Christopher H; Alam, Nur H

2016-10-01

Dehydration due to diarrhoea is a leading cause of child death worldwide, yet no clinical tools for assessing dehydration have been validated in resource-limited settings. The Dehydration: Assessing Kids Accurately (DHAKA) score was derived for assessing dehydration in children with diarrhoea in a low-income country setting. In this study, we aimed to externally validate the DHAKA score in a new population of children and compare its accuracy and reliability to the current Integrated Management of Childhood Illness (IMCI) algorithm. DHAKA was a prospective cohort study done in children younger than 60 months presenting to the International Centre for Diarrhoeal Disease Research, Bangladesh, with acute diarrhoea (defined by WHO as three or more loose stools per day for less than 14 days). Local nurses assessed children and classified their dehydration status using both the DHAKA score and the IMCI algorithm. Serial weights were obtained and dehydration status was established by percentage weight change with rehydration. We did regression analyses to validate the DHAKA score and compared the accuracy and reliability of the DHAKA score and IMCI algorithm with receiver operator characteristic (ROC) curves and the weighted κ statistic. This study was registered with ClinicalTrials.gov, number NCT02007733. Between March 22, 2015, and May 15, 2015, 496 patients were included in our primary analyses. On the basis of our criterion standard, 242 (49%) of 496 children had no dehydration, 184 (37%) of 496 had some dehydration, and 70 (14%) of 496 had severe dehydration. In multivariable regression analyses, each 1-point increase in the DHAKA score predicted an increase of 0·6% in the percentage dehydration of the child and increased the odds of both some and severe dehydration by a factor of 1·4. Both the accuracy and reliability of the DHAKA score were significantly greater than those of the IMCI algorithm. The DHAKA score is the first clinical tool for assessing

ExternE: Externalities of energy Vol. 1. Summary

International Nuclear Information System (INIS)

Holland, M.; Berry, J.

1995-01-01

There is a growing requirement for policy analysts to take account of the environment in their decision making and to undertake the specified cost-benefit analysis. Within the European Union this is reflected in the 5th Environmental Action Programme, and the Commission's White Paper entitled 'Growth, competitiveness, employment and the ways forward to the 21st century'. This has led to a need for evaluation of environmental externalities. The ExternE Project commenced in 1991 as the European part of a collaborative study between the European Commission and the US Department of Energy. It aims to be the first systematic approach to the evaluation of external costs of a wide range of different fuel cycles. The project will result in an operational accounting framework for the quantification and monetarisation of priority environmental and other externalities. This framework will allow the calculation of the marginal external costs and benefits for specific power plants, at specific sites using specified technologies. There are three major phases in the project. Phase 1 was undertaken in collaboration with the US Department of Energy. In this phase the teams jointly developed the conceptual approach and methodology and shared scientific information for application to a number of fuel cycles. On the European side work concentrated on the nuclear and coal fuel cycles which together were expected to raise many of the fundamental issues in fuel cycle analysis. The project is currently nearing completion of Phase 2. During this phase the methodology has been applied to a wide range of different fossil, nuclear and renewable fuel cycles for power generation and energy conservation options. Also a series of National Implementation Programmes is underway in which the methodology and accounting framework are being applied to reference sites throughout Europe. In addition the general methodology is being extended to address the evaluation of externalities associated with

ExternE: Externalities of energy Vol. 2. Methodology

International Nuclear Information System (INIS)

Berry, J.; Holland, M.; Watkiss, P.

1995-01-01

This report describes the methodology used by the ExternE Project of the European Commission (DGXII) JOULE Programme for assessment of the external costs of energy. It is one of a series of reports describing analysis of nuclear, fossil and renewable fuel cycles for assessment of the externalities associated with electricity generation. Part I of the report deals with analysis of impacts, and Part II with the economic valuation of those impacts. Analysis is conducted on a marginal basis, to allow the effect of an incremental investment in a given technology to be quantified. Attention has been paid to the specificity of results with respect to the location of fuel cycle activities, the precise technologies used, and the type and source of fuel. The main advantages of this detailed approach are as follows: It takes full and proper account of the variability of impacts that might result from different power projects; It is more transparent than analysis based on hypothetically 'representative' cases for each of the different fuel cycles; It provides a framework for consistent comparison between fuel cycles. A wide variety of impacts have been considered. These include the effects of air pollution on the natural and human environment, consequences of accidents in the workplace, impacts of noise and visual intrusion on amenity, and the effects of climate change arising from the release of greenhouse gases. Wherever possible we have used the 'impact pathway' or 'damage function' approach to follow the analysis from identification of burdens (e.g. emissions) through to impact assessment and then valuation in monetary terms. This has required a detailed knowledge of the technologies involved, pollutant dispersion, analysis of effects on human and environmental health, and economics. In view of this the project brought together a multi-disciplinary team with experts from many European countries and the USA. The spatial and temporal ranges considered in the analysis are

Validating an Agency-based Tool for Measuring Women's Empowerment in a Complex Public Health Trial in Rural Nepal.

Science.gov (United States)

Gram, Lu; Morrison, Joanna; Sharma, Neha; Shrestha, Bhim; Manandhar, Dharma; Costello, Anthony; Saville, Naomi; Skordis-Worrall, Jolene

2017-01-02

Despite the rising popularity of indicators of women's empowerment in global development programmes, little work has been done on the validity of existing measures of such a complex concept. We present a mixed methods validation of the use of the Relative Autonomy Index for measuring Amartya Sen's notion of agency freedom in rural Nepal. Analysis of think-aloud interviews ( n  = 7) indicated adequate respondent understanding of questionnaire items, but multiple problems of interpretation including difficulties with the four-point Likert scale, questionnaire item ambiguity and difficulties with translation. Exploratory Factor Analysis of a calibration sample ( n  = 511) suggested two positively correlated factors ( r  = 0.64) loading on internally and externally motivated behaviour. Both factors increased with decreasing education and decision-making power on large expenditures and food preparation. Confirmatory Factor Analysis on a validation sample ( n  = 509) revealed good fit (Root Mean Square Error of Approximation 0.05-0.08, Comparative Fit Index 0.91-0.99). In conclusion, we caution against uncritical use of agency-based quantification of women's empowerment. While qualitative and quantitative analysis revealed overall satisfactory construct and content validity, the positive correlation between external and internal motivations suggests the existence of adaptive preferences. High scores on internally motivated behaviour may reflect internalized oppression rather than agency freedom.

The sources of sharing externalities: Specialization vs Competition

OpenAIRE

Bucci, Alberto; Ushchev, Philip

2015-01-01

In this paper, we undertake an in-depth inquiry into the nature of sharing externalities, and study how they affect the market outcome. We show that the key thing for understanding sharing externalities is the interplay between two forces: the specialization/complexity effect, on the one hand, and the competition effect, on the other hand. How the interaction between these two forces generates endogenous increasing returns to scale is definitely understudied in the literature because of the w...

External costs related to power production technologies. ExternE national implementation for Denmark

Energy Technology Data Exchange (ETDEWEB)

Schleisner, L; Sieverts Nielsen, P [eds.

1997-12-01

The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results, to aggregate these site- and technology-specific results to more general figures. The current report covers the detailed information concerning the ExternE methodology. Importance is attached to the computer system used in the project and the assessment of air pollution effects on health, materials and ecological effects. Also the assessment of global warming damages are described. Finally the report covers the detailed information concerning the national implementation for Denmark for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant base on biogas. (au) EU-JOULE 3. 79 tabs., 11 ills., 201 refs.

External costs related to power production technologies. ExternE national implementation for Denmark

International Nuclear Information System (INIS)

Schleisner, L.; Sieverts Nielsen, P.

1997-12-01

The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results, to aggregate these site- and technology-specific results to more general figures. The current report covers the detailed information concerning the ExternE methodology. Importance is attached to the computer system used in the project and the assessment of air pollution effects on health, materials and ecological effects. Also the assessment of global warming damages are described. Finally the report covers the detailed information concerning the national implementation for Denmark for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant base on biogas. (au) EU-JOULE 3. 79 tabs., 11 ills., 201 refs

Light Water Reactor Sustainability Program Industry Application External Hazard Analyses Problem Statement

Energy Technology Data Exchange (ETDEWEB)

Szilard, Ronaldo Henriques [Idaho National Lab. (INL), Idaho Falls, ID (United States); Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Smith, Curtis L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Prescott, Steven [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kammerer, Annie [Annie Kammerer Consulting, Rye, NH (United States); Youngblood, Robert [Idaho National Lab. (INL), Idaho Falls, ID (United States); Pope, Chad [Idaho State Univ., Pocatello, ID (United States)

2015-07-01

Risk-Informed Margin Management Industry Application on External Events. More specifically, combined events, seismically induced external flooding analyses for a generic nuclear power plant with a generic site soil, and generic power plant system and structure. The focus of this report is to define the problem above, set up the analysis, describe the methods to be used, tools to be applied to each problem, and data analysis and validation associated with the above.

External validation and comparison of two variants of the Elixhauser comorbidity measures for all-cause mortality.

Directory of Open Access Journals (Sweden)

Yannick Fortin

Full Text Available Assessing prevalent comorbidities is a common approach in health research for identifying clinical differences between individuals. The objective of this study was to validate and compare the predictive performance of two variants of the Elixhauser comorbidity measures (ECM for inhospital mortality at index and at 1-year in the Cerner Health Facts® (HF U.S.We estimated the prevalence of select comorbidities for individuals 18 to 89 years of age who received care at Cerner contributing health facilities between 2002 and 2011 using the AHRQ (version 3.7 and the Quan Enhanced ICD-9-CM ECMs. External validation of the ECMs was assessed with measures of discrimination [c-statistics], calibration [Hosmer-Lemeshow goodness-of-fit test, Brier Score, calibration curves], added predictive ability [Net Reclassification Improvement], and overall model performance [R2]. Of 3,273,298 patients with a mean age of 43.9 years and a female composition of 53.8%, 1.0% died during their index encounter and 1.5% were deceased at 1-year. Calibration measures were equivalent between the two ECMs. Calibration performance was acceptable when predicting inhospital mortality at index, although recalibration is recommended for predicting inhospital mortality at 1 year. Discrimination was marginally better with the Quan ECM compared the AHRQ ECM when predicting inhospital mortality at index (cQuan = 0.887, 95% CI: 0.885-0.889 vs. cAHRQ = 0.880, 95% CI: 0.878-0.882; p < .0001 and at 1-year (cQuan = 0.884, 95% CI: 0.883-0.886 vs. cAHRQ = 0.880, 95% CI: 0.878-0.881, p < .0001. Both the Quan and the AHRQ ECMs demonstrated excellent discrimination for inhospital mortality of all-causes in Cerner Health Facts®, a HIPAA compliant observational research and privacy-protected data warehouse. While differences in discrimination performance between the ECMs were statistically significant, they are not likely clinically meaningful.

Validating an Agency-based Tool for Measuring Women’s Empowerment in a Complex Public Health Trial in Rural Nepal

Science.gov (United States)

Gram, Lu; Morrison, Joanna; Sharma, Neha; Shrestha, Bhim; Manandhar, Dharma; Costello, Anthony; Saville, Naomi; Skordis-Worrall, Jolene

2017-01-01

Abstract Despite the rising popularity of indicators of women’s empowerment in global development programmes, little work has been done on the validity of existing measures of such a complex concept. We present a mixed methods validation of the use of the Relative Autonomy Index for measuring Amartya Sen’s notion of agency freedom in rural Nepal. Analysis of think-aloud interviews (n = 7) indicated adequate respondent understanding of questionnaire items, but multiple problems of interpretation including difficulties with the four-point Likert scale, questionnaire item ambiguity and difficulties with translation. Exploratory Factor Analysis of a calibration sample (n = 511) suggested two positively correlated factors (r = 0.64) loading on internally and externally motivated behaviour. Both factors increased with decreasing education and decision-making power on large expenditures and food preparation. Confirmatory Factor Analysis on a validation sample (n = 509) revealed good fit (Root Mean Square Error of Approximation 0.05–0.08, Comparative Fit Index 0.91–0.99). In conclusion, we caution against uncritical use of agency-based quantification of women’s empowerment. While qualitative and quantitative analysis revealed overall satisfactory construct and content validity, the positive correlation between external and internal motivations suggests the existence of adaptive preferences. High scores on internally motivated behaviour may reflect internalized oppression rather than agency freedom. PMID:28303173

Findings Brief External Review of the Ecosystem Approaches to ...

International Development Research Centre (IDRC) Digital Library (Canada)

External Review of the Ecosystem Approaches to Human. Health Program ... Improved understanding of social, political, economic, and ecological interactions and .... global learning, communication among partners and others stakeholders.

French validation of the Foot Function Index (FFI).

Science.gov (United States)

Pourtier-Piotte, C; Pereira, B; Soubrier, M; Thomas, E; Gerbaud, L; Coudeyre, E

2015-10-01

French validation of the Foot Function Index (FFI), self-questionnaire designed to evaluate rheumatoid foot according to 3 domains: pain, disability and activity restriction. The first step consisted of translation/back translation and cultural adaptation according to the validated methodology. The second stage was a prospective validation on 53 patients with rheumatoid arthritis who filled out the FFI. The following data were collected: pain (Visual Analog Scale), disability (Health Assessment Questionnaire) and activity restrictions (McMaster Toronto Arthritis questionnaire). A test/retest procedure was performed 15 days later. The statistical analyses focused on acceptability, internal consistency (Cronbach's alpha and Principal Component Analysis), test-retest reproducibility (concordance coefficients), external validity (correlation coefficients) and responsiveness to change. The FFI-F is a culturally acceptable version for French patients with rheumatoid arthritis. The Cronbach's alpha ranged from 0.85 to 0.97. Reproducibility was correct (correlation coefficients>0.56). External validity and responsiveness to change were good. The use of a rigorous methodology allowed the validation of the FFI in the French language (FFI-F). This tool can be used in routine practice and clinical research for evaluating the rheumatoid foot. The FFI-F could be used in other pathologies with foot-related functional impairments. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Mapping the EORTC QLQ-C30 onto the EQ-5D-3L: assessing the external validity of existing mapping algorithms.

Science.gov (United States)

Doble, Brett; Lorgelly, Paula

2016-04-01

To determine the external validity of existing mapping algorithms for predicting EQ-5D-3L utility values from EORTC QLQ-C30 responses and to establish their generalizability in different types of cancer. A main analysis (pooled) sample of 3560 observations (1727 patients) and two disease severity patient samples (496 and 93 patients) with repeated observations over time from Cancer 2015 were used to validate the existing algorithms. Errors were calculated between observed and predicted EQ-5D-3L utility values using a single pooled sample and ten pooled tumour type-specific samples. Predictive accuracy was assessed using mean absolute error (MAE) and standardized root-mean-squared error (RMSE). The association between observed and predicted EQ-5D utility values and other covariates across the distribution was tested using quantile regression. Quality-adjusted life years (QALYs) were calculated using observed and predicted values to test responsiveness. Ten 'preferred' mapping algorithms were identified. Two algorithms estimated via response mapping and ordinary least-squares regression using dummy variables performed well on number of validation criteria, including accurate prediction of the best and worst QLQ-C30 health states, predicted values within the EQ-5D tariff range, relatively small MAEs and RMSEs, and minimal differences between estimated QALYs. Comparison of predictive accuracy across ten tumour type-specific samples highlighted that algorithms are relatively insensitive to grouping by tumour type and affected more by differences in disease severity. Two of the 'preferred' mapping algorithms suggest more accurate predictions, but limitations exist. We recommend extensive scenario analyses if mapped utilities are used in cost-utility analyses.

Externalities of fuel cycles 'ExternE' project. Summary report

International Nuclear Information System (INIS)

Holland, M.; Berry, J.

1994-01-01

There is a growing requirement for policy analysts to take account of the environment in their decision making and to undertake the specified cost-benefit analysis. Within the European Union this is reflected in the 5th Environmental Action Programme, and the Commission's White Paper entitled 'Growth, competitiveness, employment and the ways forward to the 21st century'. This has led to a need for evaluation of environmental externalities. The ExternE Project commenced in 1991 as the European part of a collaborative study between the European Commission and the US Department of Energy. It aims to be the first systematic approach to the evaluation of external costs of a wide range of different fuel cycles. The project will result in an operational accounting framework for the quantification and monetarisation of priority environmental and other externalities. This framework will allow the calculation of the marginal external costs and benefits for specific power plants, at specific sites using specified technologies. There are three major phases in the project. Phase I was undertaken in collaboration with the US Department of Energy. In this phase the teams jointly developed the conceptual approach and methodology and shared scientific information for application to a number of fuel cycles. On the European side work concentrated on the nuclear and coal fuel cycles which together were expected to raise many of the fundamental issues in fuel cycle analysis. The project is currently nearing completion of Phase 2. During this phase the methodology has been applied to a wide range of different fossil, nuclear and renewable fuel cycles for power generation and energy conservation options. Also a series of National Implementation Programmes are underway in which the methodology and accounting framework are being applied to reference sites throughout Europe. In addition the general methodology is being extended to address the evaluation of externalities associated with

Clinical prediction models for bronchopulmonary dysplasia: a systematic review and external validation study

NARCIS (Netherlands)

Onland, Wes; Debray, Thomas P.; Laughon, Matthew M.; Miedema, Martijn; Cools, Filip; Askie, Lisa M.; Asselin, Jeanette M.; Calvert, Sandra A.; Courtney, Sherry E.; Dani, Carlo; Durand, David J.; Marlow, Neil; Peacock, Janet L.; Pillow, J. Jane; Soll, Roger F.; Thome, Ulrich H.; Truffert, Patrick; Schreiber, Michael D.; van Reempts, Patrick; Vendettuoli, Valentina; Vento, Giovanni; van Kaam, Anton H.; Moons, Karel G.; Offringa, Martin

2013-01-01

Bronchopulmonary dysplasia (BPD) is a common complication of preterm birth. Very different models using clinical parameters at an early postnatal age to predict BPD have been developed with little extensive quantitative validation. The objective of this study is to review and validate clinical

An externally and internally deformable, programmable lung motion phantom

Energy Technology Data Exchange (ETDEWEB)

Cheung, Yam; Sawant, Amit, E-mail: amit.sawant@utsouthwestern.edu [UT Southwestern Medical Center, University of Texas, Dallas, Texas 75390 (United States)

2015-05-15

Purpose: Most clinically deployed strategies for respiratory motion management in lung radiotherapy (e.g., gating and tracking) use external markers that serve as surrogates for tumor motion. However, typical lung phantoms used to validate these strategies are based on a rigid exterior and a rigid or a deformable-interior. Such designs do not adequately represent respiration because the thoracic anatomy deforms internally as well as externally. In order to create a closer approximation of respiratory motion, the authors describe the construction and experimental testing of an externally as well as internally deformable, programmable lung phantom. Methods: The outer shell of a commercially available lung phantom (RS-1500, RSD, Inc.) was used. The shell consists of a chest cavity with a flexible anterior surface, and embedded vertebrae, rib-cage and sternum. A custom-made insert was designed using a piece of natural latex foam block. A motion platform was programmed with sinusoidal and ten patient-recorded lung tumor trajectories. The platform was used to drive a rigid foam “diaphragm” that compressed/decompressed the phantom interior. Experimental characterization comprised of determining the reproducibility and the external–internal correlation of external and internal marker trajectories extracted from kV x-ray fluoroscopy. Experiments were conducted to illustrate three example applications of the phantom—(i) validating the geometric accuracy of the VisionRT surface photogrammetry system; (ii) validating an image registration tool, NiftyReg; and (iii) quantifying the geometric error due to irregular motion in four-dimensional computed tomography (4DCT). Results: The phantom correctly reproduced sinusoidal and patient-derived motion, as well as realistic respiratory motion-related effects such as hysteresis. The reproducibility of marker trajectories over multiple runs for sinusoidal as well as patient traces, as characterized by fluoroscopy, was within 0

The Impact of Recipient Site External Expansion in Fat Grafting Surgical Outcomes

Directory of Open Access Journals (Sweden)

Carlo M. Oranges, MD

2018-02-01

Conclusions:. External expansion and fat grafting is a promising technique for breast reconstruction and augmentation. However, due to the overall low level of evidence of the available studies, further research is needed to validate the procedure.

Validation of a measurement tool for self-assessment of teamwork in intensive care.

Science.gov (United States)

Weller, J; Shulruf, B; Torrie, J; Frengley, R; Boyd, M; Paul, A; Yee, B; Dzendrowskyj, P

2013-09-01

Teamwork is an important contributor to patient safety and a validated teamwork measurement tool could help healthcare teams identify areas for improvement and measure progress. We explored the psychometric properties of a teamwork measurement tool when used for self-assessment. We hypothesized that the tool had a valid factor structure and that scores from participants and external assessors would correlate. Forty intensive care teams (one doctor, three nurses) participated in four simulated emergencies, and each independently rated their team's performance at the end of each case using the teamwork measurement tool, without prior training in the use of the tool. We used exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), and compared factor structure between participants and external assessors (using previously reported data). Scores from participants and external assessors were compared using Pearson's correlation coefficient. EFA demonstrated items loaded onto three distinct factors which were supported by the CFA. We found significant correlations between external and participant scores for overall teamwork scores and the three factors. Participants agreed with external assessors on the ranking of overall team performance but scored themselves significantly higher than external assessors. The teamwork measurement tool has a valid structure when used for self-assessment. Participant and external assessor scores correlated significantly, suggesting that participants could discriminate between different levels of performance, although leniency in self-assessed scores indicated the need for calibration. This tool could help structure reflection on teamwork and potentially facilitate self-directed, workplace-based improvement in teamwork.

Externalizing disorders among children of different ethnic origin in the Netherlands

NARCIS (Netherlands)

Zwirs, Barbara Wilhelmina Cornelia

2006-01-01

The overall aim of the current study was to extend the knowledge of externalizing problems in non-Western immigrant children in Europe. More specifically, the research was aimed at assessing whether the expression, treatment rates, prevalence estimates, parental detection and screening validity of

Project on Elite Athlete Commitment (PEAK): III. An examination of the external validity across gender, and the expansion and clarification of the Sport Commitment Model.

Science.gov (United States)

Scanlan, Tara K; Russell, David G; Magyar, T Michelle; Scanlan, Larry A

2009-12-01

The Sport Commitment Model was further tested using the Scanlan Collaborative Interview Method to examine its generalizability to New Zealand's elite female amateur netball team, the Silver Ferns. Results supported or clarified Sport Commitment Model predictions, revealed avenues for model expansion, and elucidated the functions of perceived competence and enjoyment in the commitment process. A comparison and contrast of the in-depth interview data from the Silver Ferns with previous interview data from a comparable elite team of amateur male athletes allowed assessment of model external validity, tested the generalizability of the underlying mechanisms, and separated gender differences from discrepancies that simply reflected team or idiosyncratic differences.

Development and external validation of nomograms to predict the risk of skeletal metastasis at the time of diagnosis and skeletal metastasis-free survival in nasopharyngeal carcinoma.

Science.gov (United States)

Yang, Lin; Xia, Liangping; Wang, Yan; He, Shasha; Chen, Haiyang; Liang, Shaobo; Peng, Peijian; Hong, Shaodong; Chen, Yong

2017-09-06

The skeletal system is the most common site of distant metastasis in nasopharyngeal carcinoma (NPC); various prognostic factors have been reported for skeletal metastasis, though most studies have focused on a single factor. We aimed to establish nomograms to effectively predict skeletal metastasis at initial diagnosis (SMAD) and skeletal metastasis-free survival (SMFS) in NPC. A total of 2685 patients with NPC who received bone scintigraphy (BS) and/or 18F-deoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and 2496 patients without skeletal metastasis were retrospectively assessed to develop individual nomograms for SMAD and SMFS. The models were validated externally using separate cohorts of 1329 and 1231 patients treated at two other institutions. Five independent prognostic factors were included in each nomogram. The SMAD nomogram had a significantly higher c-index than the TNM staging system (training cohort, P = 0.005; validation cohort, P system (P skeletal metastasis, which may improve counseling and facilitate individualized management of patients with NPC.

Development and validation of the Children’s Center Adaptation Questionnaire (CAC

Directory of Open Access Journals (Sweden)

Juan Manuel Fernández Millán

2017-12-01

Full Text Available The present study aims at the development and validation of the Center Adaptation Questionnaire (CAC by statistical homogeneity analysis, factor analysis and both internal and external validity. The questionnaire was admi- nistered to 318 children and adolescents aged between 4 and 17, from different child/youth care centers in Melilla (Spain. Statistical analyzes indicate that the questionnaire has a structure formed by two factors and 8 additional items with a Cronbach Alpha suitable for both the overall rate of the scale (0.790 and their different dimensions. These data and the correlation between total scores and external adaptation measure allow us to conclude that the Center Adaptation Questionnaire (CAC is a reliable and valid instrument.

External Validation of the ISAN, A2DS2, and AIS-APS Scores for Predicting Stroke-Associated Pneumonia.

Science.gov (United States)

Zapata-Arriaza, Elena; Moniche, Francisco; Blanca, Pardo-Galiana; Bustamante, Alejandro; Escudero-Martínez, Irene; Uclés, Oscar; Ollero-Ortiz, Ángela; Sánchez-García, Jose Antonio; Gamero, Miguel Ángel; Quesada, Ángeles; Vidal De Francisco, Diana; Romera, Mercedes; De la Cruz, Carlos; Sanz, Gema; Montaner, Joan

2018-03-01

The Prestroke Independence, Sex, Age, National Institutes of Health Stroke Scale (ISAN), Age, Atrial Fibrillation, Dysphagia, male sex, and National Institutes of Health Stroke Scale (A2DS2), and acute ischemic stroke-associated pneumonia score (AIS-APS) scores were created to predict stroke-associated pneumonia (SAP), one of the most important medical stroke complications. External validation of all such scores in an acute stroke population was the aim of our study. Patients with ischemic or hemorrhagic stroke were prospectively enrolled in the multicenter Stroke-Induced Pneumonia in Andalucía project between October 2014 and May 2016. Receiver operating characteristic curves and linear regression analyses were used to determine discrimination ability of the scores. The Hosmer-Lemeshow goodness-of-fit test and the plot of observed versus predicted SAP risk were used to assess model calibration. Among 201 included patients, SAP rate was 15.5% (31). Higher ISAN, A2DS2, and AIS-APS scores were related to SAP (all P manage SAP. The AIS-APS score would be recommendable for the development of future clinical trials. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

External built residential environment characteristics that affect mental health of adults.

Science.gov (United States)

Ochodo, Charles; Ndetei, D M; Moturi, W N; Otieno, J O

2014-10-01

External built residential environment characteristics include aspects of building design such as types of walls, doors and windows, green spaces, density of houses per unit area, and waste disposal facilities. Neighborhoods that are characterized by poor quality external built environment can contribute to psychosocial stress and increase the likelihood of mental health disorders. This study investigated the relationship between characteristics of external built residential environment and mental health disorders in selected residences of Nakuru Municipality, Kenya. External built residential environment characteristics were investigated for 544 residents living in different residential areas that were categorized by their socioeconomic status. Medically validated interview schedules were used to determine mental health of residents in the respective neighborhoods. The relationship between characteristics of the external built residential environment and mental health of residents was determined by multivariable logistic regression analyses and chi-square tests. The results show that walling materials used on buildings, density of dwelling units, state of street lighting, types of doors, states of roofs, and states of windows are some built external residential environment characteristics that affect mental health of adult males and females. Urban residential areas that are characterized by poor quality external built environment substantially expose the population to daily stressors and inconveniences that increase the likelihood of developing mental health disorders.

External costs of energy - do the answers match the questions? Looking back at 10 years of ExternE

International Nuclear Information System (INIS)

Krewitt, W.

2002-01-01

While the claim for 'getting prices right' is quite popular in conceptual policy papers, the implementation of appropriate internalisation strategies is still hampered by a lack of reliable external cost data. Great expectations were set into the ExternE project, a major research programme launched by the European Commission at the beginning of the 1990s to provide a scientific basis for the quantification of energy related externalities and to give guidance supporting the design of internalisation measures. After more than a decade of research, the ExternE label became a well recognised standard source for external cost data. Looking back into the ExternE history, the paper pursues how emerging new scientific insights and changing background assumptions affected external cost estimates and related recommendations to policy over time. Based on ExternE results, the usefulness and inherent limitations of external cost estimates for impact categories like climate change or nuclear waste disposal is discussed. The paper also gives examples on how external costs in spite of remaining uncertainties are successfully used to support environmental policy. (Author)

External event analysis methods for NUREG-1150

International Nuclear Information System (INIS)

Bohn, M.P.; Lambright, J.A.

1989-01-01

The US Nuclear Regulatory Commission is sponsoring probabilistic risk assessments of six operating commercial nuclear power plants as part of a major update of the understanding of risk as provided by the original WASH-1400 risk assessments. In contrast to the WASH-1400 studies, at least two of the NUREG-1150 risk assessments will include an analysis of risks due to earthquakes, fires, floods, etc., which are collectively known as eternal events. This paper summarizes the methods to be used in the external event analysis for NUREG-1150 and the results obtained to date. The two plants for which external events are being considered are Surry and Peach Bottom, a PWR and BWR respectively. The external event analyses (through core damage frequency calculations) were completed in June 1989, with final documentation available in September. In contrast to most past external event analyses, wherein rudimentary systems models were developed reflecting each external event under consideration, the simplified NUREG-1150 analyses are based on the availability of the full internal event PRA systems models (event trees and fault trees) and make use of extensive computer-aided screening to reduce them to sequence cut sets important to each external event. This provides two major advantages in that consistency and scrutability with respect to the internal event analysis is achieved, and the full gamut of random and test/maintenance unavailabilities are automatically included, while only those probabilistically important survive the screening process. Thus, full benefit of the internal event analysis is obtained by performing the internal and external event analyses sequentially

External stimulation strength controls actin response dynamics in Dictyostelium cells

Science.gov (United States)

Hsu, Hsin-Fang; Westendorf, Christian; Tarantola, Marco; Zykov, Vladimir; Bodenschatz, Eberhard; Beta, Carsten

2015-03-01

Self-sustained oscillation and the resonance frequency of the cytoskeletal actin polymerization/depolymerization have recently been observed in Dictyostelium, a model system for studying chemotaxis. Here we report that the resonance frequency is not constant but rather varies with the strength of external stimuli. To understand the underlying mechanism, we analyzed the polymerization and depolymerization time at different levels of external stimulation. We found that polymerization time is independent of external stimuli but the depolymerization time is prolonged as the stimulation increases. These observations can be successfully reproduced in the frame work of our time delayed differential equation model.

Getting the phenotypes right: an essential ingredient for understanding aetiological mechanisms underlying persistent violence and developing effective treatments

Directory of Open Access Journals (Sweden)

Sheilagh Hodgins

2009-11-01

Full Text Available In order to reduce societal levels of violence, it is essential to advance understanding of the neurobiological mechanisms involved in initiating and maintaining individual patterns of physical aggression. New technologies such as Magnetic Resonance Imagining and analyses of DNA provide tools for identifying these mechanisms. The reliability and validity of the results of studies using these tools depend not only on aspects of the technology, but also on the methodological rigour with which the studies are conducted, particularly with respect to characterizing the phenotype. The present article discusses five challenges confronting scientists who aim to advance understanding of the neurobiological mechanisms associated with persistent violence. These challenges are: (1 to develop evidence-based hypotheses and to design studies that test alternate hypotheses; (2 to recruit samples that are homogeneous with respect to variables that may be linked to neurobiological mechanisms underpinning violent behaviour; (3 to use reliable and valid measures in order to fully characterize participants so that the external validity of the results is evident; (4 to restrict the range of age of participants so as not to confuse developmental change with group differences; and (5 to take account of sex. Our goal is to contribute to elevating methodological standards in this new field of research and to thereby improve the validity of results and move closer to finding effective ways to reduce violence

Validity and reliability of isometric muscle strength measurements of hip abduction and abduction with external hip rotation in a bent-hip position using a handheld dynamometer with a belt.

Science.gov (United States)

Aramaki, Hidefumi; Katoh, Munenori; Hiiragi, Yukinobu; Kawasaki, Tsubasa; Kurihara, Tomohisa; Ohmi, Yorikatsu

2016-07-01

[Purpose] This study aimed to investigate the relatedness, reliability, and validity of isometric muscle strength measurements of hip abduction and abduction with an external hip rotation in a bent-hip position using a handheld dynamometer with a belt. [Subjects and Methods] Twenty healthy young adults, with a mean age of 21.5 ± 0.6 years were included. Isometric hip muscle strength in the subjects' right legs was measured under two posture positions using two devices: a handheld dynamometer with a belt and an isokinetic dynamometer. Reliability was evaluated using an intra-class correlation coefficient (ICC); relatedness and validity were evaluated using Pearson's product moment correlation coefficient. Differences in measurements of devices were assessed by two-way ANOVA. [Results] ICC (1, 1) was ≥0.9; significant positive correlations in measurements were found between the two devices under both conditions. No main effect was found between the measurement values. [Conclusion] Our findings revealed that there was relatedness, reliability, and validity of this method for isometric muscle strength measurements using a handheld dynamometer with a belt.

Impact of external conditions on energy consumption in industrial halls

Science.gov (United States)

Żabnieńśka-Góra, Alina

2017-11-01

The energy demand for heating the halls buildings is high. The impact on this may have the technology of production, building construction and technology requirements (HVAC systems). The isolation of the external partitions, the location of the object in relation to the surrounding buildings and the degree of the interior insolation (windows and skylights) are important in the context of energy consumption. The article discusses the impact of external conditions, wind and sunlight on energy demand in the industrial hall. The building model was prepared in IDA ICE 4.0 simulation software. Model validation was done based on measurements taken in the analyzed building.

The ExternE project: methodology, objectives and limitations

International Nuclear Information System (INIS)

Rabl, A.; Spadaro, J.V.

2002-01-01

This paper presents a summary of recent studies on external costs of energy systems, in particular the ExternE (External Costs of Energy) Project of the European Commission. To evaluate the impact and damage cost of a pollutant, one needs to carry out an impact pathway analysis; this involves the calculation of increased pollutant concentrations in all affected regions due to an incremental emission (e.g. μg/m 3 of particles, using models of atmospheric dispersion and chemistry), followed by the calculation of physical impacts (e.g. number of cases of asthma due to these particles, using a dose-response function). The entire so-called fuel chain (or fuel cycle) is evaluated and compared on the basis of delivered end use energy. Even though the uncertainties are large, the results provide substantial evidence that the classical air pollutants (particles, NO x and SO x ) from the combustion of fossil fuels impose a heavy toll, in addition to the cost of global warming. The external costs are especially large for coal; even for 'good current technology' they may be comparable to the price of electricity. For natural gas the external costs are about a third to a half of coal. The external costs of nuclear are small compared to the price of electricity (at most a few %), and so are the external costs of most renewable energy systems. (authors)

Structure-independent cross-validation between residual dipolar couplings originating from internal and external orienting media

International Nuclear Information System (INIS)

Barbieri, Renato; Bertini, Ivano; Lee, Yong-Min; Luchinat, Claudio; Velders, Aldrik H.

2002-01-01

Lanthanide-substituted calcium binding proteins are known to partially orient in high magnetic fields. Orientation provides residual dipolar couplings (rdc's). Two of these systems, Tm 3+ - and Dy 3+ -substituted calbindin D 9k , dissolved in an external orienting medium (nonionic liquid crystalline phase) provide rdc values which are the sum of those induced by the lanthanides and by the liquid crystalline phase on the native calcium binding protein. This structure-independent check shows the innocence of the orienting medium with respect to the structure of the protein in solution. Furthermore, the simultaneous use of lanthanide substitution and external orienting media provides a further effective tool to control and tune the orientation tensor

Predictive accuracy of the PanCan lung cancer risk prediction model - external validation based on CT from the Danish Lung Cancer Screening Trial

International Nuclear Information System (INIS)

Winkler Wille, Mathilde M.; Dirksen, Asger; Riel, Sarah J. van; Jacobs, Colin; Scholten, Ernst T.; Ginneken, Bram van; Saghir, Zaigham; Pedersen, Jesper Holst; Hohwue Thomsen, Laura; Skovgaard, Lene T.

2015-01-01

Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models. From the DLCST database, 1,152 nodules from 718 participants were included. Parsimonious and full PanCan risk prediction models were applied to DLCST data, and also coefficients of the model were recalculated using DLCST data. Receiver operating characteristics (ROC) curves and area under the curve (AUC) were used to evaluate risk discrimination. AUCs of 0.826-0.870 were found for DLCST data based on PanCan risk prediction models. In the DLCST, age and family history were significant predictors (p = 0.001 and p = 0.013). Female sex was not confirmed to be associated with higher risk of lung cancer; in fact opposing effects of sex were observed in the two cohorts. Thus, female sex appeared to lower the risk (p = 0.047 and p = 0.040) in the DLCST. High risk discrimination was validated in the DLCST cohort, mainly determined by nodule size. Age and family history of lung cancer were significant predictors and could be included in the parsimonious model. Sex appears to be a less useful predictor. (orig.)

Predictive accuracy of the PanCan lung cancer risk prediction model - external validation based on CT from the Danish Lung Cancer Screening Trial

Energy Technology Data Exchange (ETDEWEB)

Winkler Wille, Mathilde M.; Dirksen, Asger [Gentofte Hospital, Department of Respiratory Medicine, Hellerup (Denmark); Riel, Sarah J. van; Jacobs, Colin; Scholten, Ernst T.; Ginneken, Bram van [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Saghir, Zaigham [Herlev Hospital, Department of Respiratory Medicine, Herlev (Denmark); Pedersen, Jesper Holst [Copenhagen University Hospital, Department of Thoracic Surgery, Rigshospitalet, Koebenhavn Oe (Denmark); Hohwue Thomsen, Laura [Hvidovre Hospital, Department of Respiratory Medicine, Hvidovre (Denmark); Skovgaard, Lene T. [University of Copenhagen, Department of Biostatistics, Koebenhavn Oe (Denmark)

2015-10-15

Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models. From the DLCST database, 1,152 nodules from 718 participants were included. Parsimonious and full PanCan risk prediction models were applied to DLCST data, and also coefficients of the model were recalculated using DLCST data. Receiver operating characteristics (ROC) curves and area under the curve (AUC) were used to evaluate risk discrimination. AUCs of 0.826-0.870 were found for DLCST data based on PanCan risk prediction models. In the DLCST, age and family history were significant predictors (p = 0.001 and p = 0.013). Female sex was not confirmed to be associated with higher risk of lung cancer; in fact opposing effects of sex were observed in the two cohorts. Thus, female sex appeared to lower the risk (p = 0.047 and p = 0.040) in the DLCST. High risk discrimination was validated in the DLCST cohort, mainly determined by nodule size. Age and family history of lung cancer were significant predictors and could be included in the parsimonious model. Sex appears to be a less useful predictor. (orig.)

German Translation and Validation of the Cognitive Style Questionnaire Short Form (CSQ-SF-D.

Directory of Open Access Journals (Sweden)

Quentin J M Huys

Full Text Available The Cognitive Style Questionnaire is a valuable tool for the assessment of hopeless cognitive styles in depression research, with predictive power in longitudinal studies. However, it is very burdensome to administer. Even the short form is still long, and neither this nor the original version exist in validated German translations.The questionnaire was translated from English to German, back-translated and commented on by clinicians. The reliability, factor structure and external validity of an online form of the questionnaire were examined on 214 participants. External validity was measured on a subset of 90 subjects.The resulting CSQ-SF-D had good to excellent reliability, both across items and subscales, and similar external validity to the original English version. The internality subscale appeared less robust than other subscales. A detailed analysis of individual item performance suggests that stable results could be achieved with a very short form (CSQ-VSF-D including only 27 of the 72 items.The CSQ-SF-D is a validated and freely distributed translation of the CSQ-SF into German. This should make efficient assessment of cognitive style in German samples more accessible to researchers.

External costs related to power production technologies. ExternE national implementation for Denmark

International Nuclear Information System (INIS)

Schleisner, L.; Sieverts Nielsen, P.

1997-12-01

The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results; to aggregate these site- and technology-specific results to more general figures. The current report covers the results of the national implementation for Denmark. Three different fuel cycles have been chosen as case studies. These are fuel cycles for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant based on biogas. The report covers all the details of the application of the methodology to these fuel cycles aggregation to a national level. (au) EU-JOULE 3. 59 tabs., 25 ills., 61 refs

External costs related to power production technologies. ExternE national implementation for Denmark

Energy Technology Data Exchange (ETDEWEB)

Schleisner, L; Sieverts Nielsen, P

1997-12-01

The objective of the ExternE National Implementation project has been to establish a comprehensive and comparable set of data on externalities of power generation for all EU member states and Norway. The tasks include the application of the ExternE methodology to the most important fuel cycles for each country as well as to update the already existing results; to aggregate these site- and technology-specific results to more general figures. The current report covers the results of the national implementation for Denmark. Three different fuel cycles have been chosen as case studies. These are fuel cycles for an offshore wind farm and a wind farm on land, a decentralised CHP plant based on natural gas and a decentralised CHP plant based on biogas. The report covers all the details of the application of the methodology to these fuel cycles aggregation to a national level. (au) EU-JOULE 3. 59 tabs., 25 ills., 61 refs.

Environmental externalities related to power production on biogas and natural gas based on the EU ExternE methodology

DEFF Research Database (Denmark)

Nielsen, Per Sieverts; Ibsen, Liselotte Schleisner

1998-01-01

This paper assesses the environmental impacts and external costs from selected electricity generation systems in Denmark. The assessment is carried out as part of the ExternE National Implementation, which is the second phase of the ExternE project and involves case studies from all Western...... European countries. The project use a “bottom-up” methodology to evaluate the external costs associated with a wide range of different fuel cycles. The project has identified priority impacts, where most are impacts from air emissions. Externalities due to atmospheric emissions are calculated through...

Multi-Informant Assessment of Temperament in Children with Externalizing Behavior Problems

Science.gov (United States)

Copeland, William; Landry, Kerry; Stanger, Catherine; Hudziak, James J.

2004-01-01

We examined the criterion validity of parent and self-report versions of the Junior Temperament and Character Inventory (JTCI) in children with high levels of externalizing problems. The sample included 412 children (206 participants and 206 siblings) participating in a family study of attention and aggressive behavior problems. Criterion validity…

Time-dependent anisotropic external sources in transient 3-D transport code TORT-TD

International Nuclear Information System (INIS)

Seubert, A.; Pautz, A.; Becker, M.; Dagan, R.

2009-01-01

This paper describes the implementation of a time-dependent distributed external source in TORT-TD by explicitly considering the external source in the ''fixed-source'' term of the implicitly time-discretised 3-D discrete ordinates transport equation. Anisotropy of the external source is represented by a spherical harmonics series expansion similar to the angular fluxes. The YALINA-Thermal subcritical assembly serves as a test case. The configuration with 280 fuel rods has been analysed with TORT-TD using cross sections in 18 energy groups and P1 scattering order generated by the KAPROS code system. Good agreement is achieved concerning the multiplication factor. The response of the system to an artificial time-dependent source consisting of two square-wave pulses demonstrates the time-dependent external source capability of TORT-TD. The result is physically plausible as judged from validation calculations. (orig.)

External details revisited - A new taxonomy for coding 'non-episodic' content during autobiographical memory retrieval.

Science.gov (United States)

Strikwerda-Brown, Cherie; Mothakunnel, Annu; Hodges, John R; Piguet, Olivier; Irish, Muireann

2018-04-24

Autobiographical memory (ABM) is typically held to comprise episodic and semantic elements, with the vast majority of studies to date focusing on profiles of episodic details in health and disease. In this context, 'non-episodic' elements are often considered to reflect semantic processing or are discounted from analyses entirely. Mounting evidence suggests that rather than reflecting one unitary entity, semantic autobiographical information may contain discrete subcomponents, which vary in their relative degree of semantic or episodic content. This study aimed to (1) review the existing literature to formally characterize the variability in analysis of 'non-episodic' content (i.e., external details) on the Autobiographical Interview and (2) use these findings to create a theoretically grounded framework for coding external details. Our review exposed discrepancies in the reporting and interpretation of external details across studies, reinforcing the need for a new, consistent approach. We validated our new external details scoring protocol (the 'NExt' taxonomy) in patients with Alzheimer's disease (n = 18) and semantic dementia (n = 13), and 20 healthy older Control participants and compared profiles of the NExt subcategories across groups and time periods. Our results revealed increased sensitivity of the NExt taxonomy in discriminating between ABM profiles of patient groups, when compared to traditionally used internal and external detail metrics. Further, remote and recent autobiographical memories displayed distinct compositions of the NExt detail types. This study is the first to provide a fine-grained and comprehensive taxonomy to parse external details into intuitive subcategories and to validate this protocol in neurodegenerative disorders. © 2018 The British Psychological Society.

Translation and validation of the German version of the Bournemouth Questionnaire for Neck Pain

Directory of Open Access Journals (Sweden)

Soklic Marina

2012-01-01

Full Text Available Abstract Background Clinical outcome measures are important tools to monitor patient improvement during treatment as well as to document changes for research purposes. The short-form Bournemouth questionnaire for neck pain patients (BQN was developed from the biopsychosocial model and measures pain, disability, cognitive and affective domains. It has been shown to be a valid and reliable outcome measure in English, French and Dutch and more sensitive to change compared to other questionnaires. The purpose of this study was to translate and validate a German version of the Bournemouth questionnaire for neck pain patients. Methods German translation and back translation into English of the BQN was done independently by four persons and overseen by an expert committee. Face validity of the German BQN was tested on 30 neck pain patients in a single chiropractic practice. Test-retest reliability was evaluated on 31 medical students and chiropractors before and after a lecture. The German BQN was then assessed on 102 first time neck pain patients at two chiropractic practices for internal consistency, external construct validity, external longitudinal construct validity and sensitivity to change compared to the German versions of the Neck Disability Index (NDI and the Neck Pain and Disability Scale (NPAD. Results Face validity testing lead to minor changes to the German BQN. The Intraclass Correlation Coefficient for the test-retest reliability was 0.99. The internal consistency was strong for all 7 items of the BQN with Cronbach α's of .79 and .80 for the pre and post-treatment total scores. External construct validity and external longitudinal construct validity using Pearson's correlation coefficient showed statistically significant correlations for all 7 scales of the BQN with the other questionnaires. The German BQN showed greater responsiveness compared to the other questionnaires for all scales. Conclusions The German BQN is a valid and

Gating based on internal/external signals with dynamic correlation updates

International Nuclear Information System (INIS)

Wu Huanmei; Zhao Qingya; Berbeco, Ross I; Nishioka, Seiko; Shirato, Hiroki; Jiang, Steve B

2008-01-01

Precise localization of mobile tumor positions in real time is critical to the success of gated radiotherapy. Tumor positions are usually derived from either internal or external surrogates. Fluoroscopic gating based on internal surrogates, such as implanted fiducial markers, is accurate however requiring a large amount of imaging dose. Gating based on external surrogates, such as patient abdominal surface motion, is non-invasive however less accurate due to the uncertainty in the correlation between tumor location and external surrogates. To address these complications, we propose to investigate an approach based on hybrid gating with dynamic internal/external correlation updates. In this approach, the external signal is acquired at high frequency (such as 30 Hz) while the internal signal is sparsely acquired (such as 0.5 Hz or less). The internal signal is used to validate and update the internal/external correlation during treatment. Tumor positions are derived from the external signal based on the newly updated correlation. Two dynamic correlation updating algorithms are introduced. One is based on the motion amplitude and the other is based on the motion phase. Nine patients with synchronized internal/external motion signals are simulated retrospectively to evaluate the effectiveness of hybrid gating. The influences of different clinical conditions on hybrid gating, such as the size of gating windows, the optimal timing for internal signal acquisition and the acquisition frequency are investigated. The results demonstrate that dynamically updating the internal/external correlation in or around the gating window will reduce false positive with relatively diminished treatment efficiency. This improvement will benefit patients with mobile tumors, especially greater for early stage lung cancers, for which the tumors are less attached or freely floating in the lung.

Gating based on internal/external signals with dynamic correlation updates

Energy Technology Data Exchange (ETDEWEB)

Wu Huanmei [Purdue School of Engineering and Technology, Indiana University School of Informatics, IUPUI, Indianapolis, IN (United States); Zhao Qingya [School of Health Sciences, Purdue University, West Lafayette, IN (United States); Berbeco, Ross I [Department of Radiation Oncology, Dana-Farber/Brigham and Womens Cancer Center and Harvard Medical School, Boston, MA (United States); Nishioka, Seiko [NTT East-Japan Sapporo Hospital, Sapporo (Japan); Shirato, Hiroki [Hokkaido University Graduate School of Medicine, Sapporo (Japan); Jiang, Steve B [Department of Radiation Oncology, School of Medicine, University of California, San Diego, CA (United States)], E-mail: hw9@iupui.edu, E-mail: sbjiang@ucsd.edu

2008-12-21

Precise localization of mobile tumor positions in real time is critical to the success of gated radiotherapy. Tumor positions are usually derived from either internal or external surrogates. Fluoroscopic gating based on internal surrogates, such as implanted fiducial markers, is accurate however requiring a large amount of imaging dose. Gating based on external surrogates, such as patient abdominal surface motion, is non-invasive however less accurate due to the uncertainty in the correlation between tumor location and external surrogates. To address these complications, we propose to investigate an approach based on hybrid gating with dynamic internal/external correlation updates. In this approach, the external signal is acquired at high frequency (such as 30 Hz) while the internal signal is sparsely acquired (such as 0.5 Hz or less). The internal signal is used to validate and update the internal/external correlation during treatment. Tumor positions are derived from the external signal based on the newly updated correlation. Two dynamic correlation updating algorithms are introduced. One is based on the motion amplitude and the other is based on the motion phase. Nine patients with synchronized internal/external motion signals are simulated retrospectively to evaluate the effectiveness of hybrid gating. The influences of different clinical conditions on hybrid gating, such as the size of gating windows, the optimal timing for internal signal acquisition and the acquisition frequency are investigated. The results demonstrate that dynamically updating the internal/external correlation in or around the gating window will reduce false positive with relatively diminished treatment efficiency. This improvement will benefit patients with mobile tumors, especially greater for early stage lung cancers, for which the tumors are less attached or freely floating in the lung.

Assessing self-determined motivation for addiction treatment: validity of the Treatment Entry Questionnaire.

Science.gov (United States)

Urbanoski, Karen A; Wild, T Cameron

2012-07-01

Although legal, formal, and informal social controls are frequently used to pressure individuals to enter treatment, motivational consequences of using these tactics have been neglected. Self-determination theory (SDT) provides a useful perspective for understanding client experiences of social controls and highlights the importance of self-determined motivation for long-term behavior change. This study assessed the construct validity of the Treatment Entry Questionnaire (TEQ), a brief scale derived from SDT to measure identified, introjected, and external treatment motivation. Two independent samples of clients entering Canadian residential and outpatient treatment completed TEQ items (ns = 529 and 623). Exploratory and confirmatory factor analyses supported a 9-item version of the scale, with 3 factors aligning with SDT motivational subtypes. Subscales showed high internal consistency and correlated as expected with social controls and perceived coercion at treatment entry. The TEQ-9 is a valid option for assessing self-determined motivation in clinical practice and evaluating coerced addiction treatment. Copyright © 2012 Elsevier Inc. All rights reserved.

External Validation and Evaluation of Reliability and Validity of the Modified Seoul National University Renal Stone Complexity Scoring System to Predict Stone-Free Status After Retrograde Intrarenal Surgery.

Science.gov (United States)

Park, Juhyun; Kang, Minyong; Jeong, Chang Wook; Oh, Sohee; Lee, Jeong Woo; Lee, Seung Bae; Son, Hwancheol; Jeong, Hyeon; Cho, Sung Yong

2015-08-01

The modified Seoul National University Renal Stone Complexity scoring system (S-ReSC-R) for retrograde intrarenal surgery (RIRS) was developed as a tool to predict stone-free rate (SFR) after RIRS. We externally validated the S-ReSC-R. We retrospectively reviewed 159 patients who underwent RIRS. The S-ReSC-R was assigned from 1 to 12 according to the location and number of sites involved. The stone-free status was defined as no evidence of a stone or with clinically insignificant residual fragment stones less than 2 mm. Interobserver and test-retest reliabilities were evaluated. Statistical performance of the prediction model was assessed by its predictive accuracy, predictive probability, and clinical usefulness. Overall SFR was 73.0%. The SFRs were 86.7%, 70.2%, and 48.6% in low-score (1-2), intermediate-score (3-4), and high-score (5-12) groups, respectively (pR revealed an area under the curve (AUC) of 0.731 (95% CI 0.650-0.813). The AUC of the three-titered S-ReSC-R was 0.701 (95% CI 0.609-0.794). The calibration plot showed that the predicted probability of SFR had a concordance comparable to that of observed frequency. The Hosmer-Lemeshow goodness of fit test revealed a p-value of 0.01 for the S-ReSC-R and 0.90 for the three-titered S-ReSC-R. Interobserver and test-retest reliabilities revealed an almost perfect level of agreement. The present study proved the predictive value of S-ReSC-R to predict SFR following RIRS in an independent cohort. Interobserver and test-retest reliabilities confirmed that S-ReSC-R was reliable and valid.

Sample size calculation to externally validate scoring systems based on logistic regression models.

Directory of Open Access Journals (Sweden)

Antonio Palazón-Bru

Full Text Available A sample size containing at least 100 events and 100 non-events has been suggested to validate a predictive model, regardless of the model being validated and that certain factors can influence calibration of the predictive model (discrimination, parameterization and incidence. Scoring systems based on binary logistic regression models are a specific type of predictive model.The aim of this study was to develop an algorithm to determine the sample size for validating a scoring system based on a binary logistic regression model and to apply it to a case study.The algorithm was based on bootstrap samples in which the area under the ROC curve, the observed event probabilities through smooth curves, and a measure to determine the lack of calibration (estimated calibration index were calculated. To illustrate its use for interested researchers, the algorithm was applied to a scoring system, based on a binary logistic regression model, to determine mortality in intensive care units.In the case study provided, the algorithm obtained a sample size with 69 events, which is lower than the value suggested in the literature.An algorithm is provided for finding the appropriate sample size to validate scoring systems based on binary logistic regression models. This could be applied to determine the sample size in other similar cases.

Understanding vented gas explosions

Energy Technology Data Exchange (ETDEWEB)

Lautkaski, R. [VTT Energy, Espoo (Finland). Energy Systems

1997-12-31

The report is an introduction to vented gas explosions for nonspecialists, particularly designers of plants for flammable gases and liquids. The phenomena leading to pressure generation in vented gas explosions in empty and congested rooms are reviewed. The four peak model of vented gas explosions is presented with simple methods to predict the values of the individual peaks. Experimental data on the external explosion of dust and gas explosions is discussed. The empirical equation relating the internal and external peak pressures in vented dust explosions is shown to be valid for gas explosion tests in 30 m{sup 3} and 550 m{sup 3} chambers. However, the difficulty of predicting the internal peak pressure in large chambers remains. Methods of explosion relief panel design and principles of vent and equipment layout to reduce explosion overpressures are reviewed. (orig.) 65 refs.

Understanding vented gas explosions

Energy Technology Data Exchange (ETDEWEB)

Lautkaski, R [VTT Energy, Espoo (Finland). Energy Systems

1998-12-31

The report is an introduction to vented gas explosions for nonspecialists, particularly designers of plants for flammable gases and liquids. The phenomena leading to pressure generation in vented gas explosions in empty and congested rooms are reviewed. The four peak model of vented gas explosions is presented with simple methods to predict the values of the individual peaks. Experimental data on the external explosion of dust and gas explosions is discussed. The empirical equation relating the internal and external peak pressures in vented dust explosions is shown to be valid for gas explosion tests in 30 m{sup 3} and 550 m{sup 3} chambers. However, the difficulty of predicting the internal peak pressure in large chambers remains. Methods of explosion relief panel design and principles of vent and equipment layout to reduce explosion overpressures are reviewed. (orig.) 65 refs.

External validation of the use of vignettes in cross-country health studies

DEFF Research Database (Denmark)

Datta Gupta, Nabanita; Kristensen, Nicolai; Pozzoli, Dario

2010-01-01

Cross-country comparisons of subjective assessments are rendered difficult if not impossible because of sub-population specific response style. To correct for this, the use of vignettes has become increasingly popular, notably within cross-country health studies. However, the validity of vignette...... and vignettes. Our results indicate that the assumption of RC is not innocuous and that our extended model relaxing this assumption improves the fit and significantly changes the cross-country rankings of health vis-a-vis the standard Chopit model.......Cross-country comparisons of subjective assessments are rendered difficult if not impossible because of sub-population specific response style. To correct for this, the use of vignettes has become increasingly popular, notably within cross-country health studies. However, the validity of vignettes...

External Validation of the Use of Vignettes in Cross-Country Health Studies

DEFF Research Database (Denmark)

Datta Gupta, Nabanita; Kristensen, Nicolai; Pozzoli, Dario

Cross-country comparisons of subjective assessments are rendered difficult if not impossible because of sub-population specific response style. To correct for this, the use of vignettes has become increasingly popular, notably within cross-country health studies. However, the validity of vignette...... and vignettes. Our results indicate that the assumption of RC is not innocuous and that our extended model relaxing this assumption improves the fit and significantly changes the cross-country rankings of health vis-à-vis the standard Chopit model.......Cross-country comparisons of subjective assessments are rendered difficult if not impossible because of sub-population specific response style. To correct for this, the use of vignettes has become increasingly popular, notably within cross-country health studies. However, the validity of vignettes...

External validation of the use of vignettes in cross-country health studies

DEFF Research Database (Denmark)

Gupta, Nabanita Datta; Kristensen, Nicolai; Pozzoli, Dario

Cross-country comparisons of subjective assessments are rendered difficult if not impossible because of sub-population specific response style. To correct for this, the use of vignettes has become increasingly popular, notably within cross-country health studies. However, the validity of vignette...... and vignettes. Our results indicate that the assumption of RC is not innocous and that our extended model relaxing this assumption improves the fit and significantly changes the cross-country rankings of health vis-\\'{a}-vis the standard Chopit model.......Cross-country comparisons of subjective assessments are rendered difficult if not impossible because of sub-population specific response style. To correct for this, the use of vignettes has become increasingly popular, notably within cross-country health studies. However, the validity of vignettes...

Development and validation of the Stirling Eating Disorder Scales.

Science.gov (United States)

Williams, G J; Power, K G; Miller, H R; Freeman, C P; Yellowlees, A; Dowds, T; Walker, M; Parry-Jones, W L

1994-07-01

The development and reliability/validity check of an 80-item, 8-scale measure for use with eating disorder patients is presented. The Stirling Eating Disorder Scales (SEDS) assess anorexic dietary behavior, anorexic dietary cognitions, bulimic dietary behavior, bulimic dietary cognitions, high perceived external control, low assertiveness, low self-esteem, and self-directed hostility. The SEDS were administered to 82 eating disorder patients and 85 controls. Results indicate that the SEDS are acceptable in terms of internal consistency, reliability, group validity, and concurrent validity.

External validity of randomized controlled trials of glycaemic control and vascular disease: how representative are participants?

Science.gov (United States)

Saunders, C; Byrne, C D; Guthrie, B; Lindsay, R S; McKnight, J A; Philip, S; Sattar, N; Walker, J J; Wild, S H

2013-03-01

To describe the proportion of people with Type 2 diabetes living in Scotland who meet eligibility criteria for inclusion in several large randomized controlled trials of glycaemic control to inform physicians and guideline developers about the generalizibility of trial results. A literature review was performed to identify large trials assessing the impact of glycaemic control on risk of macrovascular disease. Inclusion and exclusion criteria from each trial were applied to data on the population of people with a diagnosis of Type 2 diabetes living in Scotland in 2008 (n = 180,590) in a population-based cross-sectional study and the number and proportion of people eligible for each trial was determined. Seven trials were identified. The proportion of people with Type 2 diabetes who met the eligibility criteria for the trials ranged from 3.5 to 50.7%. Trial participants were younger at age of diagnosis of diabetes and at time of trial recruitment than in the Scottish study population. The application of upper age criteria excluded the largest proportion of patients, with up to 39% of people with Type 2 diabetes ineligible for a trial with the most stringent criteria based on age alone. We found that many of the large trials of glycaemic control among people with Type 2 diabetes have limited external validity when applied to a population-based cohort of people with Type 2 diabetes. In particular, the age distribution of trial participants often does not reflect that of people with Type 2 diabetes in a contemporary British population. © 2012 The Authors. Diabetic Medicine © 2012 Diabetes UK.

Effort, symptom validity testing, performance validity testing and traumatic brain injury.

Science.gov (United States)

Bigler, Erin D

2014-01-01

To understand the neurocognitive effects of brain injury, valid neuropsychological test findings are paramount. This review examines the research on what has been referred to a symptom validity testing (SVT). Above a designated cut-score signifies a 'passing' SVT performance which is likely the best indicator of valid neuropsychological test findings. Likewise, substantially below cut-point performance that nears chance or is at chance signifies invalid test performance. Significantly below chance is the sine qua non neuropsychological indicator for malingering. However, the interpretative problems with SVT performance below the cut-point yet far above chance are substantial, as pointed out in this review. This intermediate, border-zone performance on SVT measures is where substantial interpretative challenges exist. Case studies are used to highlight the many areas where additional research is needed. Historical perspectives are reviewed along with the neurobiology of effort. Reasons why performance validity testing (PVT) may be better than the SVT term are reviewed. Advances in neuroimaging techniques may be key in better understanding the meaning of border zone SVT failure. The review demonstrates the problems with rigidity in interpretation with established cut-scores. A better understanding of how certain types of neurological, neuropsychiatric and/or even test conditions may affect SVT performance is needed.

The impact of morality on externalizing behaviour : values, reasoning, cognitive distortions and identity

NARCIS (Netherlands)

Beerthuizen, M.G.C.J.

2012-01-01

The current dissertation investigated the association between several aspects of morality and externalizing behaviour among adolescents. The first study assessed the validity of the Sociomoral Reflection Measure - Short Form Objective (SRM-SFO). The SRM-SFO appears to be a promising instrument for

Sperm motility of externally fertilizing fish and amphibians.

Science.gov (United States)

Browne, R K; Kaurova, S A; Uteshev, V K; Shishova, N V; McGinnity, D; Figiel, C R; Mansour, N; Agney, D; Wu, M; Gakhova, E N; Dzyuba, B; Cosson, J

2015-01-01

We review the phylogeny, sperm competition, morphology, physiology, and fertilization environments of the sperm of externally fertilizing fish and amphibians. Increased sperm competition in both fish and anurans generally increases sperm numbers, sperm length, and energy reserves. The difference between the internal osmolarity and iconicity of sperm cells and those of the aquatic medium control the activation, longevity, and velocity of sperm motility. Hypo-osmolarity of the aquatic medium activates the motility of freshwater fish and amphibian sperm and hyperosmolarity activates the motility of marine fish sperm. The average longevity of the motility of marine fish sperm (~550 seconds) was significantly (P amphibian sperm in general and anurans reversion from internal to external fertilization. Our findings provide a greater understanding of the reproductive biology of externally fertilizing fish and amphibians, and a biological foundation for the further development of reproduction technologies for their sustainable management.

Regulating multiple externalities

DEFF Research Database (Denmark)

Waldo, Staffan; Jensen, Frank; Nielsen, Max

2016-01-01

Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory instrume......Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory...

Socioeconomic Status, Parenting, and Externalizing Problems in African American Single-Mother Homes: A Person-Oriented Approach

Science.gov (United States)

Anton, Margaret T.; Jones, Deborah J.; Youngstrom, Eric A.

2016-01-01

African American youth, particularly those from single-mother homes, are overrepresented in statistics on externalizing problems. The family is a central context in which to understand externalizing problems; however, reliance on variable-oriented approaches to the study of parenting, which originate from work with intact, middle-income, European American families, may obscure important information regarding variability in parenting styles among African American single mothers, and in turn, variability in youth outcomes as well. The current study demonstrated that within African American single-mother families: (a) a person-, rather than variable-, oriented approach to measuring parenting style may further elucidate variability; (b) socioeconomic status may provide 1 context within which to understanding variability in parenting style; and (c) 1 marker of socioeconomic status, income, and parenting style may each explain variability in youth externalizing problems; however, the interaction between income and parenting style was not significant. Findings have potential implications for better understanding the specific contexts in which externalizing problems may be most likely to occur within this at-risk and underserved group. PMID:26053349

Socioeconomic status, parenting, and externalizing problems in African American single-mother homes: A person-oriented approach.

Science.gov (United States)

Anton, Margaret T; Jones, Deborah J; Youngstrom, Eric A

2015-06-01

African American youth, particularly those from single-mother homes, are overrepresented in statistics on externalizing problems. The family is a central context in which to understand externalizing problems; however, reliance on variable-oriented approaches to the study of parenting, which originate from work with intact, middle-income, European American families, may obscure important information regarding variability in parenting styles among African American single mothers, and in turn, variability in youth outcomes as well. The current study demonstrated that within African American single-mother families: (a) a person-, rather than variable-, oriented approach to measuring parenting style may further elucidate variability; (b) socioeconomic status may provide 1 context within which to understanding variability in parenting style; and (c) 1 marker of socioeconomic status, income, and parenting style may each explain variability in youth externalizing problems; however, the interaction between income and parenting style was not significant. Findings have potential implications for better understanding the specific contexts in which externalizing problems may be most likely to occur within this at-risk and underserved group. (c) 2015 APA, all rights reserved).

Small--radiation-amplitude dynamical voltage model of an irradiated, externally unbiased Josephson tunnel junction

International Nuclear Information System (INIS)

McAdory, R.T. Jr.

1988-01-01

A theory is presented for the nonequilibrium voltage states of an irradiated Josephson junction shunted by an external resistor but with no external current or voltage biasing. This device, referred to as a free-running Josephson junction, is modeled in a small--radiation-amplitude, deterministic regime extending the previous work of Shenoy and Agarwal. The time-averaged induced voltage is treated as a dynamical variable, the external radiation is modeled as a current source, and the induced junction-radiation vector potential, with and without a mode structure, is treated to first order in the driving currents. A dynamical equation for the time-averaged induced voltage yields a (nonequilibrium) steady-state relation between the time-averaged induced voltage and the incident radiation amplitude valid for a wide range of voltages, including zero. Regions of bistability occur in the voltage--versus--incident-amplitude curves, some of which are dependent on the external resistor. The zero-voltage state breaks down, as the external radiation amplitude is increased, at a critical value of the incident-radiation amplitude inversely proportional to the external resistance

Construction and validation of a Tamil logMAR chart.

Science.gov (United States)

Varadharajan, Srinivasa; Srinivasan, Krithica; Kumaresan, Brindha

2009-09-01

To design, construct and validate a new Tamil logMAR visual acuity chart based on current recommendations. Ten Tamil letters of equal legibility were identified experimentally and were used in the chart. Two charts, one internally illuminated and one externally illuminated, were constructed for testing at 4 m distance. The repeatability of the two charts was tested. For validation, the two charts were compared with a standard English logMAR chart (ETDRS). When compared to the ETDRS chart, a difference of 0.06 +/- 0.07 and 0.07 +/- 0.07 logMAR was found for the internally and externally illuminated charts respectively. Limits of agreement between the internally illuminated Tamil logMAR chart and ETDRS chart were found to be (-0.08, 0.19), and (-0.07, 0.20) for the externally illuminated chart. The test - retest results showed a difference of 0.02 +/- 0.04 and 0.02 +/- 0.06 logMAR for the internally and externally illuminated charts respectively. Limits of agreement for repeated measurements for the internally illuminated Tamil logMAR chart were found to be (-0.06, 0.10), and (-0.10, 0.14) for the externally illuminated chart. The newly constructed Tamil logMAR charts have good repeatability. The difference in visual acuity scores between the newly constructed Tamil logMAR chart and the standard English logMAR chart was within acceptable limits. This new chart can be used for measuring visual acuity in the literate Tamil population.

Approaches in estimation of external cost for fuel cycles in the ExternE project

International Nuclear Information System (INIS)

Afanas'ev, A.A.; Maksimenko, B.N.

1998-01-01

The purposes, content and main results of studies realized within the frameworks of the International Project ExternE which is the first comprehensive attempt to develop general approach to estimation of external cost for different fuel cycles based on utilization of nuclear and fossil fuels, as well as on renewable power sources are discussed. The external cost of a fuel cycle is treated as social and environmental expenditures which are not taken into account by energy producers and consumers, i.e. these are expenditures not included into commercial cost nowadays. The conclusion on applicability of the approach suggested for estimation of population health hazards and environmental impacts connected with electric power generation growth (expressed in money or some other form) is made

Perturbative neutrino pair creation by an external source

International Nuclear Information System (INIS)

Koers, Hylke B.J.

2005-01-01

We consider the rate of fermion-antifermion pair creation by an external field. We derive a rate formula that is valid for a coupling with arbitrary vector and axial vector components to first order in perturbation theory. This is then applied to study the creation of neutrinos by nuclear matter, a problem with astrophysical relevance. We present an estimate for the creation rate per unit volume, compare this to previous results and comment on the role of the neutrino mass

Predictive Accuracy of the PanCan Lung Cancer Risk Prediction Model -External Validation based on CT from the Danish Lung Cancer Screening Trial

DEFF Research Database (Denmark)

Winkler Wille, Mathilde M.; van Riel, Sarah J.; Saghir, Zaigham

2015-01-01

Objectives: Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models. Methods: From...... the DLCST database, 1,152 nodules from 718 participants were included. Parsimonious and full PanCan risk prediction models were applied to DLCST data, and also coefficients of the model were recalculated using DLCST data. Receiver operating characteristics (ROC) curves and area under the curve (AUC) were...... used to evaluate risk discrimination. Results: AUCs of 0.826–0.870 were found for DLCST data based on PanCan risk prediction models. In the DLCST, age and family history were significant predictors (p = 0.001 and p = 0.013). Female sex was not confirmed to be associated with higher risk of lung cancer...

Structural Continuum Modeling of Space Shuttle External Tank Foam Insulation

Science.gov (United States)

Steeve, Brian; Ayala, Sam; Purlee, T. Eric; Shaw, Phillip

2006-01-01

This document is a viewgraph presentation reporting on work in modeling the foam insulation of the Space Shuttle External Tank. An analytical understanding of foam mechanics is required to design against structural failure. The Space Shuttle External Tank is covered primarily with closed cell foam to: Prevent ice, Protect structure from ascent aerodynamic and engine plume heating, and Delay break-up during re-entry. It is important that the foam does not shed unacceptable debris during ascent environment. Therefore a modeling of the foam insulation was undertaken.

The Impact of Overreporting on MMPI-2-RF Substantive Scale Score Validity

Science.gov (United States)

Burchett, Danielle L.; Ben-Porath, Yossef S.

2010-01-01

This study examined the impact of overreporting on the validity of Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) substantive scale scores by comparing correlations with relevant external criteria (i.e., validity coefficients) of individuals who completed the instrument under instructions to (a) feign psychopathology…

Cognitive Dissonance as an Instructional Tool for Understanding Chemical Representations

Science.gov (United States)

Corradi, David; Clarebout, Geraldine; Elen, Jan

2015-01-01

Previous research on multiple external representations (MER) indicates that sequencing representations (compared with presenting them as a whole) can, in some cases, increase conceptual understanding if there is interference between internal and external representations. We tested this mechanism by sequencing different combinations of scientific…

Analysis of External Treatment Methods and Technical Characteristics of External Treatment

Science.gov (United States)

Zhang, Rui; Miao, Mingsan; Bai, Ming

2018-01-01

Chinese medicine external therapy is a treatment method of Chinese medicine with Chinese characteristics. The effect of traditional Chinese medicine external treatment, convenient operation, external treatment and technology has great prospects for development. The traditional Chinese medicine external treatment method and technical characteristics were analyzed.

Analysis of risk factors for schizophrenia with two different case definitions: a nationwide register-based external validation study.

Science.gov (United States)

Sørensen, Holger J; Larsen, Janne T; Mors, Ole; Nordentoft, Merete; Mortensen, Preben B; Petersen, Liselotte

2015-03-01

Different case definitions of schizophrenia have been used in register based research. However, no previous study has externally validated two different case definitions of schizophrenia against a wide range of risk factors for schizophrenia. We investigated hazard ratios (HRs) for a wide range of risk factors for ICD-10 DCR schizophrenia using a nationwide Danish sample of 2,772,144 residents born in 1955-1997. We compared one contact only (OCO) (the case definition of schizophrenia used in Danish register based studies) with two or more contacts (TMC) (a case definition of at least 2 inpatient contacts with schizophrenia). During the follow-up, the OCO definition included 15,074 and the TMC 7562 cases; i.e. half as many. The TMC case definition appeared to select for a worse illness course. A wide range of risk factors were uniformly associated with both case definitions and only slightly higher risk estimates were found for the TMC definition. Choosing at least 2 inpatient contacts with schizophrenia (TMC) instead of the currently used case definition would result in almost similar risk estimates for many well-established risk factors. However, this would also introduce selection and include considerably fewer cases and reduce power of e.g. genetic studies based on register-diagnosed cases only. Copyright © 2015 Elsevier B.V. All rights reserved.

External validation of a measurement tool to assess systematic reviews (AMSTAR.

Directory of Open Access Journals (Sweden)

Beverley J Shea

Full Text Available BACKGROUND: Thousands of systematic reviews have been conducted in all areas of health care. However, the methodological quality of these reviews is variable and should routinely be appraised. AMSTAR is a measurement tool to assess systematic reviews. METHODOLOGY: AMSTAR was used to appraise 42 reviews focusing on therapies to treat gastro-esophageal reflux disease, peptic ulcer disease, and other acid-related diseases. Two assessors applied the AMSTAR to each review. Two other assessors, plus a clinician and/or methodologist applied a global assessment to each review independently. CONCLUSIONS: The sample of 42 reviews covered a wide range of methodological quality. The overall scores on AMSTAR ranged from 0 to 10 (out of a maximum of 11 with a mean of 4.6 (95% CI: 3.7 to 5.6 and median 4.0 (range 2.0 to 6.0. The inter-observer agreement of the individual items ranged from moderate to almost perfect agreement. Nine items scored a kappa of >0.75 (95% CI: 0.55 to 0.96. The reliability of the total AMSTAR score was excellent: kappa 0.84 (95% CI: 0.67 to 1.00 and Pearson's R 0.96 (95% CI: 0.92 to 0.98. The overall scores for the global assessment ranged from 2 to 7 (out of a maximum score of 7 with a mean of 4.43 (95% CI: 3.6 to 5.3 and median 4.0 (range 2.25 to 5.75. The agreement was lower with a kappa of 0.63 (95% CI: 0.40 to 0.88. Construct validity was shown by AMSTAR convergence with the results of the global assessment: Pearson's R 0.72 (95% CI: 0.53 to 0.84. For the AMSTAR total score, the limits of agreement were -0.19+/-1.38. This translates to a minimum detectable difference between reviews of 0.64 'AMSTAR points'. Further validation of AMSTAR is needed to assess its validity, reliability and perceived utility by appraisers and end users of reviews across a broader range of systematic reviews.

On the contribution of external cost calculations to energy system governance: The case of a potential large-scale nuclear accident

International Nuclear Information System (INIS)

Laes, Erik; Meskens, Gaston; Sluijs, Jeroen P. van der

2011-01-01

The contribution of nuclear power to a sustainable energy future is a contested issue. This paper presents a critical review of an attempt to objectify this debate through the calculation of the external costs of a potential large-scale nuclear accident in the ExternE project. A careful dissection of the ExternE approach resulted in a list of 30 calculation steps and assumptions, from which the 6 most contentious ones were selected through a stakeholder internet survey. The policy robustness and relevance of these key assumptions were then assessed in a workshop using the concept of a 'pedigree of knowledge'. Overall, the workshop outcomes revealed the stakeholder and expert panel's scepticism about the assumptions made: generally these were considered not very plausible, subjected to disagreement, and to a large extent inspired by contextual factors. Such criticism indicates a limited validity and useability of the calculated nuclear accident externality as a trustworthy sustainability indicator. Furthermore, it is our contention that the ExternE project could benefit greatly - in terms of gaining public trust - from employing highly visible procedures of extended peer review such as the pedigree assessment applied to our specific case of the external costs of a potential large-scale nuclear accident. - Highlights: → Six most contentious assumptions were selected through a stakeholder internet survey. → Policy robustness of these assumptions was assessed in a pedigree assessment workshop. → Assumptions were considered implausible, controversial, and inspired by contextual factors. → This indicates a limited validity and useability as a trustworthy sustainability indicator.

[Interpersonal attention management inventory: a new instrument to capture different self- and external perception skills].

Science.gov (United States)

Blaser, Klaus; Zlabinger, Milena; Hinterberger, Thilo

2014-01-01

The Interpersonal Attention Management Inventory (IAMI) represents a new instrument to capture self- and external perception skills. The underlying theoretical model assumes 3 mental locations of attention (the intrapersonal space, the extrapersonal space, and the external intrapersonal space) of the other. The IAMI was studied regarding its factor structure; it was shortened and statistical values as well as first reference values were calculated based on a larger sample (n = 1089). By factor analysis, the superordinate scales could be widely validated. The shortened version with 31 items and 3 superordinate scales shows a high reliability of the global value (Cronbach's α = 0.81) and, regarding the convergent validity, a modest correlation (r = 0.41) of the global value and mindfulness, measured with the Freiburg Mindfulness Inventory (FMI). Further validation studies are invited so that the IAMI can be used as an instrument for (course) diagnosis in the therapy of psychiatric disorders as well as for research in social neuroscience, e.g., in investigations on mindfulness, compassion, empathy, theory of mind, and self-boundaries.

The Subaxial Cervical Spine Injury Classification System: an external agreement validation study

NARCIS (Netherlands)

Middendorp, J.J. van; Audige, L.; Bartels, R.H.M.A.; Bolger, C.; Deverall, H.; Dhoke, P.; Diekerhof, C.H.; Govaert, G.A.; Guimera, V.; Koller, H.; Morris, S.A.; Setiobudi, T.; Hosman, A.J.F.

2013-01-01

BACKGROUND CONTEXT: In 2007, the Subaxial Cervical Spine Injury Classification (SLIC) system was introduced demonstrating moderate reliability in an internal validation study. PURPOSE: To assess the agreement on the SLIC system using clinical data from a spinal trauma population and whether the SLIC

The Subaxial Cervical Spine Injury Classification System : an external agreement validation study

NARCIS (Netherlands)

van Middendorp, Joost J.; Audige, Laurent; Bartels, Ronald H.; Bolger, Ciaran; Deverall, Hamish; Dhoke, Priyesh; Diekerhof, Carel H.; Govaert, Geertje A. M.; Guimera, Vicente; Koller, Heiko; Morris, Stephen A. C.; Setiobudi, Tony; Hosman, Allard J. F.

BACKGROUND CONTEXT: In 2007, the Subaxial Cervical Spine Injury Classification (SLIC) system was introduced demonstrating moderate reliability in an internal validation study. PURPOSE: To assess the agreement on the SLIC system using clinical data from a spinal trauma population and whether the SLIC

ExternE: Externalities of energy Vol. 5. Nuclear

International Nuclear Information System (INIS)

Dreicer, M.; Tort, V.; Manen, P.

1995-01-01

Since the early 1970s, there has been increased interest in the environmental impacts that are caused by the generation of electricity. The comparative risk assessment studies at that time used mainly deaths and injuries as impact indicators. By the end of the 1980s studies changed to the assessment of the costs imposed on society and the environment that were not included in the market price of the energy produced, the so-called external costs. The preliminary studies that were published set the conceptual basis, grounded in neo-classical economics, for the valuation of the health and environmental impacts that could be assessed. As a consequence of the many questions raised by the methodologies employed by these early studies, Directorate General XII (DG XII) of the Commission of the European Communities established a collaborative research programme with the United States Department of Energy to identify an appropriate methodology for this type of work. Following the completion of this collaboration, the DG XII programme has continued as the ExternE project. The main objective of the work carried out at CEPN was to develop an impact pathway methodology for the nuclear fuel cycle that would be consistent with the methodologies developed for other fuel cycles, without loosing the nuclear-specific techniques required for a proper evaluation. In this way, comparisons between the different fuel cycles would be possible. This report presents the methodology and demonstration of the results in the context of the French nuclear fuel cycle. The United States team at Oak Ridge National Laboratory has previously issued a draft report on the results of their assessment. The French fuel cycle was broken down into 8 separate stages. Reference sites and 1990s technology were chosen to represent the total nuclear fuel cycle, as it exists today. In addition, the transportation of material between the sites was considered. The facilities are assessed for routine operation, except

ExternE: Externalities of energy Vol. 4. Oil and gas

International Nuclear Information System (INIS)

Friedrich, R.; Krewitt, W.; Mayerhofer, P.

1995-01-01

Awareness of the environmental damage resulting from human activity, particularly commencing energy use, has grown greatly in recent years. Effects such as global warming, ozone depletion and acid rain are now the subjects of much research and public debate. It is now known that these and other effects damage a wide range of receptors, including human health, forests, crops, freshwater ecosystems and buildings. Such damages are typically not accounted for by the producers and consumers of the good in question (in this case energy). They are thus referred to as 'external costs' or 'externalities', to distinguish them from the private costs which account for the construction of plant, cost of fuel, wages, etc. In recent years there has been a growing interest in the assessment of the environmental and health impacts of energy, and the related external costs. This concern is driven by a number of different factors: the need to integrate environmental concerns in decision making over the choice between different fuels and energy technologies; the need to evaluate the costs and benefits of stricter environmental standards; increased attention to the use of economic instruments for environmental policy, the need to develop overall indicators of environmental performance of different technologies; major changes in the energy sector, including privatisation, liberalisation of markets, reduction of subsidies, etc. An agreed methodology for calculation and integration of external costs has not been established. Earlier work is typically of a preliminary nature and tends to be deficient with respect to both the methods employed and the quality of models and data used. In consequence of this a collaborative project, the EC/US Fuel Cycles Study, was established between Directorate General XLI (Science, Research and Technology) of the European Commission and the United States Department of Energy. This ran for the period 1991 to 1993, and good agreement on a variety of

Participatory action research designs in applied disability and rehabilitation science: protecting against threats to social validity.

Science.gov (United States)

Seekins, Tom; White, Glen W

2013-01-01

Researchers and disability advocates have been debating consumer involvement in disability and rehabilitation science since at least 1972. Despite the length of this debate, much confusion remains. Consumer involvement may represent a spirit of democracy or even empowerment, but as a tool of science, it is necessary to understand how to judge its application. To realize consumer involvement as a design element in science, researchers need a framework for understanding how it can contribute to the scientific process. The thesis of this article is that a primary scientific function of consumer involvement is to reduce threats to the social validity of research, the extent to which those expected to use or benefit from research products judge them as useful and actually use them. Social validity has traditionally not been treated with the same rigor as concerns for internal and external validity. This article presents a framework that describes 7 threats to social validity and explains how 15 forms of consumer involvement protect against those threats. We also suggest procedures for reporting and reviewing consumer involvement in proposals and manuscripts. This framework offers tools familiar to all scientists for identifying threats to the quality of research, and for judging the effectiveness of strategies for protecting against those threats. It may also enhance the standing of consumer involvement strategies as tools for protecting research quality by organizing them in a way that allows for systematic criticism of their effectiveness and subsequent improvement. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Extreme external events in the design and assessment of nuclear power plants

International Nuclear Information System (INIS)

2003-03-01

: identification of major unresolved safety issues and of areas of potential future improvement/clarification, overview of adopted approaches in Member States for site evaluation and design of new and existing plants, presentation and discussion of few case studies and examples from regulatory and engineering practice, preparation of a technical report, synthesis among the contents of current IAEA Safety Guides and the most updated engineering practice in Member States, for a common understanding of major safety issues connected with extreme events. This publication refers to nuclear power plants. However most of its content is still valid for other nuclear facilities provided the necessary 'grading' is applied. External events in this publication include also events originated at the site, of such nature that they can be assimilated, in terms of source and effect characterization, to events originated off the site

Effect of external pulsation on kinematics of fluid particles in the field ...

Indian Academy of Sciences (India)

The effect of external pulsation on a pair of stationary Lamb–Oseen vortices of equal strength has been analyzed to investigate kinematic behavior of a fluid particle. The assumption of vortices being treated stationary or fixed vortex filaments is valid in a reference frame attached to the vortex system with axes along and ...

Internal and External Validation of a multivariable Model to Define Hospital-Acquired Pneumonia After Esophagectomy

NARCIS (Netherlands)

Weijs, Teus J; Seesing, Maarten F J; van Rossum, Peter S N; Koëter, Marijn; van der Sluis, Pieter C; Luyer, Misha D P; Ruurda, Jelle P; Nieuwenhuijzen, Grard A P; van Hillegersberg, Richard

BACKGROUND: Pneumonia is an important complication following esophagectomy; however, a wide range of pneumonia incidence is reported. The lack of one generally accepted definition prevents valid inter-study comparisons. We aimed to simplify and validate an existing scoring model to define pneumonia

Evaluation of the Match External Load in Soccer: Methods Comparison.

Science.gov (United States)

Castagna, Carlo; Varley, Matthew; Póvoas, Susana C A; D'Ottavio, Stefano

2017-04-01

To test the interchangeability of 2 match-analysis approaches for external-load detection considering arbitrary selected speeds and metabolic power (MP) thresholds in male top-level soccer. Data analyses were performed considering match physical performance of 60 matches (1200 player cases) of randomly selected Spanish, German, and English first-division championship matches (2013-14 season). Match analysis was performed with a validated semiautomated multicamera system operating at 25 Hz. During a match, players covered 10,673 ± 348 m, of which 1778 ± 208 m and 2759 ± 241 m were performed at high intensity, as measured using speed (≥16 km/h, HI) and metabolic power (≥20 W/kg, MPHI) notations. High-intensity notations were nearly perfectly associated (r = .93, P Player high-intensity decelerations (≥-2 m/s 2 ) were very largely associated with MPHI (r = .73, P physical match-analysis methods can be independently used to track match external load in elite-level players. However, match-analyst decisions must be based on use of a single method to avoid bias in external-load determination.

An External Archive-Guided Multiobjective Particle Swarm Optimization Algorithm.

Science.gov (United States)

Zhu, Qingling; Lin, Qiuzhen; Chen, Weineng; Wong, Ka-Chun; Coello Coello, Carlos A; Li, Jianqiang; Chen, Jianyong; Zhang, Jun

2017-09-01

The selection of swarm leaders (i.e., the personal best and global best), is important in the design of a multiobjective particle swarm optimization (MOPSO) algorithm. Such leaders are expected to effectively guide the swarm to approach the true Pareto optimal front. In this paper, we present a novel external archive-guided MOPSO algorithm (AgMOPSO), where the leaders for velocity update are all selected from the external archive. In our algorithm, multiobjective optimization problems (MOPs) are transformed into a set of subproblems using a decomposition approach, and then each particle is assigned accordingly to optimize each subproblem. A novel archive-guided velocity update method is designed to guide the swarm for exploration, and the external archive is also evolved using an immune-based evolutionary strategy. These proposed approaches speed up the convergence of AgMOPSO. The experimental results fully demonstrate the superiority of our proposed AgMOPSO in solving most of the test problems adopted, in terms of two commonly used performance measures. Moreover, the effectiveness of our proposed archive-guided velocity update method and immune-based evolutionary strategy is also experimentally validated on more than 30 test MOPs.

External mean flow influence on sound transmission through finite clamped double-wall sandwich panels

Science.gov (United States)

Liu, Yu; Catalan, Jean-Cédric

2017-09-01

This paper studies the influence of an external mean flow on the sound transmission through finite clamped double-wall sandwich panels lined with poroelastic materials. Biot's theory is employed to describe wave propagation in poroelastic materials and various configurations of coupling the poroelastic layer to the facing plates are considered. The clamped boundary of finite panels are dealt with by the modal superposition theory and the weighted residual (Garlekin) method, leading to a matrix equation solution for the sound transmission loss (STL) through the structure. The theoretical model is validated against existing theories of infinite sandwich panels with and without an external flow. The numerical results of a single incident wave show that the external mean flow has significant effects on the STL which are coupled with the clamped boundary effect dominating in the low-frequency range. The external mean flow also influences considerably the limiting incidence angle of the panel system and the effect of the incidence angle on the STL. However, the influences of the azimuthal angle and the external flow orientation are negligible.

Evaluation of external hazards to nuclear power plants in the United States

International Nuclear Information System (INIS)

Kimura, C.Y.; Budnitz, R.J.

1987-12-01

The Lawrence Livermore National Laboratory (LLNL) has performed a study of the risk of core damage to nuclear power plants in the United States due to externally initiated events. The broad objective has been to gain an understanding of whether or not each external initiator is among the major potential accident initiators that may pose a threat of severe reactor core damage or of large radioactive release to the environment from the reactor. Four external hazards were investigated in this report. These external hazards are internal fires, high winds/tornadoes, external floods, and transportation accidents. Analysis was based on two figures-of-merit, one based on core damage frequency and the other based on the frequency of large radioactive releases. Using these two figures-of-merit as evaluation criteria, it has been feasible to ascertain whether the risk from externally initiated accidents is, or is not, an important contributor to overall risk for the US nuclear power plants studied. This has been accomplished for each initiator separately. 208 refs., 17 figs., 45 tabs

Development and External Validation of the Korean Prostate Cancer Risk Calculator for High-Grade Prostate Cancer: Comparison with Two Western Risk Calculators in an Asian Cohort.

Science.gov (United States)

Park, Jae Young; Yoon, Sungroh; Park, Man Sik; Choi, Hoon; Bae, Jae Hyun; Moon, Du Geon; Hong, Sung Kyu; Lee, Sang Eun; Park, Chanwang; Byun, Seok-Soo

2017-01-01

We developed the Korean Prostate Cancer Risk Calculator for High-Grade Prostate Cancer (KPCRC-HG) that predicts the probability of prostate cancer (PC) of Gleason score 7 or higher at the initial prostate biopsy in a Korean cohort (http://acl.snu.ac.kr/PCRC/RISC/). In addition, KPCRC-HG was validated and compared with internet-based Western risk calculators in a validation cohort. Using a logistic regression model, KPCRC-HG was developed based on the data from 602 previously unscreened Korean men who underwent initial prostate biopsies. Using 2,313 cases in a validation cohort, KPCRC-HG was compared with the European Randomized Study of Screening for PC Risk Calculator for high-grade cancer (ERSPCRC-HG) and the Prostate Cancer Prevention Trial Risk Calculator 2.0 for high-grade cancer (PCPTRC-HG). The predictive accuracy was assessed using the area under the receiver operating characteristic curve (AUC) and calibration plots. PC was detected in 172 (28.6%) men, 120 (19.9%) of whom had PC of Gleason score 7 or higher. Independent predictors included prostate-specific antigen levels, digital rectal examination findings, transrectal ultrasound findings, and prostate volume. The AUC of the KPCRC-HG (0.84) was higher than that of the PCPTRC-HG (0.79, pexternal validation. Calibration plots also revealed better performance of KPCRC-HG and ERSPCRC-HG than that of PCPTRC-HG on external validation. At a cut-off of 5% for KPCRC-HG, 253 of the 2,313 men (11%) would not have been biopsied, and 14 of the 614 PC cases with Gleason score 7 or higher (2%) would not have been diagnosed. KPCRC-HG is the first web-based high-grade prostate cancer prediction model in Korea. It had higher predictive accuracy than PCPTRC-HG in a Korean population and showed similar performance with ERSPCRC-HG in a Korean population. This prediction model could help avoid unnecessary biopsy and reduce overdiagnosis and overtreatment in clinical settings.

Effort-Based Decision-Making Paradigms for Clinical Trials in Schizophrenia: Part 2—External Validity and Correlates.

Science.gov (United States)

Horan, William P; Reddy, L Felice; Barch, Deanna M; Buchanan, Robert W; Dunayevich, Eduardo; Gold, James M; Marder, Steven R; Wynn, Jonathan K; Young, Jared W; Green, Michael F

2015-09-01

Effort-based decision making has strong conceptual links to the motivational disturbances that define a key subdomain of negative symptoms. However, the extent to which effort-based decision-making performance relates to negative symptoms, and other clinical and functionally important variables has yet to be systematically investigated. In 94 clinically stable outpatients with schizophrenia, we examined the external validity of 5 effort-based paradigms, including the Effort Expenditure for Rewards, Balloon Effort, Grip Strength Effort, Deck Choice Effort, and Perceptual Effort tasks. These tasks covered 3 types of effort: physical, cognitive, and perceptual. Correlations between effort related performance and 6 classes of variables were examined, including: (1) negative symptoms, (2) clinically rated motivation and community role functioning, (3) self-reported motivational traits, (4) neurocognition, (5) other psychiatric symptoms and clinical/demographic characteristics, and (6) subjective valuation of monetary rewards. Effort paradigms showed small to medium relationships to clinical ratings of negative symptoms, motivation, and functioning, with the pattern more consistent for some measures than others. They also showed small to medium relations with neurocognitive functioning, but were generally unrelated to other psychiatric symptoms, self-reported traits, antipsychotic medications, side effects, and subjective valuation of money. There were relatively strong interrelationships among the effort measures. In conjunction with findings from a companion psychometric article, all the paradigms warrant further consideration and development, and 2 show the strongest potential for clinical trial use at this juncture. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Do clinical and translational science graduate students understand linear regression? Development and early validation of the REGRESS quiz.

Science.gov (United States)

Enders, Felicity

2013-12-01

Although regression is widely used for reading and publishing in the medical literature, no instruments were previously available to assess students' understanding. The goal of this study was to design and assess such an instrument for graduate students in Clinical and Translational Science and Public Health. A 27-item REsearch on Global Regression Expectations in StatisticS (REGRESS) quiz was developed through an iterative process. Consenting students taking a course on linear regression in a Clinical and Translational Science program completed the quiz pre- and postcourse. Student results were compared to practicing statisticians with a master's or doctoral degree in statistics or a closely related field. Fifty-two students responded precourse, 59 postcourse , and 22 practicing statisticians completed the quiz. The mean (SD) score was 9.3 (4.3) for students precourse and 19.0 (3.5) postcourse (P REGRESS quiz was internally reliable (Cronbach's alpha 0.89). The initial validation is quite promising with statistically significant and meaningful differences across time and study populations. Further work is needed to validate the quiz across multiple institutions. © 2013 Wiley Periodicals, Inc.

A concept of external aerodynamic elements in improving the performance of natural smoke ventilation in wind conditions

Science.gov (United States)

Wegrzyński, Wojciech; Krajewski, Grzegorz; Kimbar, Grzegorz

2018-01-01

This paper is a proposal of a new device that may be used as a component of natural smoke ventilation systems - an external aerodynamic baffle used to limit the wind effect at the most adverse angle. Natural ventilation is not only affected by the external wind, but also dependent on the angle of wind attack. It has been proven, that at angles between 45° to 60° the performance of such device is the lowest. This is the reason why additional device is proposed - external baffle that could hypothetically increase the performance at chosen angles. The purpose of this paper is to explore this idea by numerical modelling of such external elements on a validated natural ventilator model, with use of ANSYS® Fluent® CFD model.

External Nutrient Inputs into Lake Kivu: Rivers and Atmospheric ...

African Journals Online (AJOL)

Quantifying the external nutrients inputs is a key factor for understanding the formation of methane in Lake Kivu. This tectonic lake located between Rwanda and DRC contains a big quantity of dissolved gases predominated by carbon dioxide, methane and sulphide. The CH4 is most probably produced in the lake, mainly in ...

Impulsive Flocking of Dynamical Multiagent Systems with External Disturbances

Directory of Open Access Journals (Sweden)

Fujun Han

2017-01-01

Full Text Available Flocking motion of multiagent systems is influenced by various external disturbances in complex environment. By applying disturbance observer, flocking of multiagent systems with exogenous disturbances is studied. Based on the robust features of impulsive control, a distributed impulsive control protocol is presented with disturbance observer, and flocking motion of multiagent systems is analyzed. Moreover, a sufficient condition is obtained to ensure the flocking motion of multiagent systems following a leader. Finally, simulation results show the validity of the theoretical conclusion.

Interprofessional education and social interaction: The use of automated external defibrillators in team-based basic life support.

Science.gov (United States)

Onan, Arif; Simsek, Nurettin

2017-04-01

Automated external defibrillators are pervasive computing devices designed for the treatment and management of acute sudden cardiac arrest. This study aims to explain users' actual use behavior in teams formed by different professions taken after a short time span of interaction with automated external defibrillator. Before the intervention, all the participants were certified with the American Heart Association Basic Life Support for healthcare providers. A statistically significant difference was revealed in mean individual automated external defibrillator technical skills between uniprofessional and interprofessional groups. The technical automated external defibrillator team scores were greater for groups with interprofessional than for those with uniprofessional education. The nontechnical automated external defibrillator skills of interprofessional and uniprofessional teams revealed differences in advantage of interprofessional teams. Students positively accept automated external defibrillators if well-defined and validated training opportunities to use them expertly are available. Uniprofessional teams were successfully supported by their members and, thereby, used automated external defibrillator effectively. Furthermore, the interprofessional approach resulted in as much effective teamwork as the uniprofessional approach.

Characteristics of a multisensor system for non invasive glucose monitoring with external validation and prospective evaluation.

Science.gov (United States)

Caduff, Andreas; Mueller, Martin; Megej, Alexander; Dewarrat, Francois; Suri, Roland E; Klisic, Jelena; Donath, Marc; Zakharov, Pavel; Schaub, Dominik; Stahel, Werner A; Talary, Mark S

2011-05-15

The Multisensor Glucose Monitoring System (MGMS) features non invasive sensors for dielectric characterisation of the skin and underlying tissue in a wide frequency range (1 kHz-100 MHz, 1 and 2 GHz) as well as optical characterisation. In this paper we describe the results of using an MGMS in a miniaturised housing with fully integrated sensors and battery. Six patients with Type I Diabetes Mellitus (age 44±16 y; BMI 24.1±1.3 kg/m(2), duration of diabetes 27±12 y; HbA1c 7.3±1.0%) wore a single Multisensor at the upper arm position and performed a total of 45 in-clinic study days with 7 study days per patient on average (min. 5 and max. 10). Glucose changes were induced either orally or by i.v. glucose administration and the blood glucose was measured routinely. Several prospective data evaluation routines were applied to evaluate the data. The results are shown using one of the restrictive data evaluation routines, where measurements from the first 22 study days were used to train a linear regression model. The global model was then prospectively applied to the data of the remaining 23 study days to allow for an external validation of glucose prediction. The model application yielded a Mean Absolute Relative Difference of 40.8%, a Mean Absolute Difference of 51.9 mg dL(-1), and a correlation of 0.84 on average per study day. The Clarke error grid analyses showed 89.0% in A+B, 4.5% in C, 4.6% in D and 1.9% in the E region. Prospective application of a global, purely statistical model, demonstrates that glucose variations can be tracked non invasively by the MGMS in most cases under these conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

European Randomized Study of Screening for Prostate Cancer Risk Calculator: External Validation, Variability, and Clinical Significance.

Science.gov (United States)

Gómez-Gómez, Enrique; Carrasco-Valiente, Julia; Blanca-Pedregosa, Ana; Barco-Sánchez, Beatriz; Fernandez-Rueda, Jose Luis; Molina-Abril, Helena; Valero-Rosa, Jose; Font-Ugalde, Pilar; Requena-Tapia, Maria José

2017-04-01

To externally validate the European Randomized Study of Screening for Prostate Cancer (ERSPC) risk calculator (RC) and to evaluate its variability between 2 consecutive prostate-specific antigen (PSA) values. We prospectively catalogued 1021 consecutive patients before prostate biopsy for suspicion of prostate cancer (PCa). The risk of PCa and significant PCa (Gleason score ≥7) from 749 patients was calculated according to ERSPC-RC (digital rectal examination-based version 3 of 4) for 2 consecutive PSA tests per patient. The calculators' predictions were analyzed using calibration plots and the area under the receiver operating characteristic curve (area under the curve). Cohen kappa coefficient was used to compare the ability and variability. Of 749 patients, PCa was detected in 251 (33.5%) and significant PCa was detected in 133 (17.8%). Calibration plots showed an acceptable parallelism and similar discrimination ability for both PSA levels with an area under the curve of 0.69 for PCa and 0.74 for significant PCa. The ERSPC showed 226 (30.2%) unnecessary biopsies with the loss of 10 significant PCa. The variability of the RC was 16% for PCa and 20% for significant PCa, and a higher variability was associated with a reduced risk of significant PCa. We can conclude that the performance of the ERSPC-RC in the present cohort shows a high similitude between the 2 PSA levels; however, the RC variability value is associated with a decreased risk of significant PCa. The use of the ERSPC in our cohort detects a high number of unnecessary biopsies. Thus, the incorporation of ERSPC-RC could help the clinical decision to carry out a prostate biopsy. Copyright © 2016 Elsevier Inc. All rights reserved.

External Validation of Risk Prediction Scores for Invasive Candidiasis in a Medical/Surgical Intensive Care Unit: An Observational Study

Science.gov (United States)

Ahmed, Armin; Baronia, Arvind Kumar; Azim, Afzal; Marak, Rungmei S. K.; Yadav, Reema; Sharma, Preeti; Gurjar, Mohan; Poddar, Banani; Singh, Ratender Kumar

2017-01-01

Background: The aim of this study was to conduct external validation of risk prediction scores for invasive candidiasis. Methods: We conducted a prospective observational study in a 12-bedded adult medical/surgical Intensive Care Unit (ICU) to evaluate Candida score >3, colonization index (CI) >0.5, corrected CI >0.4 (CCI), and Ostrosky's clinical prediction rule (CPR). Patients' characteristics and risk factors for invasive candidiasis were noted. Patients were divided into two groups; invasive candidiasis and no-invasive candidiasis. Results: Of 198 patients, 17 developed invasive candidiasis. Discriminatory power (area under receiver operator curve [AUROC]) for Candida score, CI, CCI, and CPR were 0.66, 0.67, 0.63, and 0.62, respectively. A large number of patients in the no-invasive candidiasis group (114 out of 181) were exposed to antifungal agents during their stay in ICU. Subgroup analysis was carried out after excluding such patients from no-invasive candidiasis group. AUROC of Candida score, CI, CCI, and CPR were 0.7, 0.7, 0.65, and 0.72, respectively, and positive predictive values (PPVs) were in the range of 25%–47%, along with negative predictive values (NPVs) in the range of 84%–96% in the subgroup analysis. Conclusion: Currently available risk prediction scores have good NPV but poor PPV. They are useful for selecting patients who are not likely to benefit from antifungal therapy. PMID:28904481

The Interstellar Medium in External Galaxies: Summaries of contributed papers

Science.gov (United States)

Hollenbach, David J. (Editor); Thronson, Harley A., Jr. (Editor)

1990-01-01

The Second Wyoming Conference entitled, The Interstellar Medium in External Galaxies, was held on July 3 to 7, 1989, to discuss the current understanding of the interstellar medium in external galaxies and to analyze the basic physical processes underlying interstellar phenomena. The papers covered a broad range of research on the gas and dust in external galaxies and focused on such topics as the distribution and morphology of the atomic, molecular, and dust components; the dynamics of the gas and the role of the magnetic field in the dynamics; elemental abundances and gas depletions in the atomic and ionized components; cooling flows; star formation; the correlation of the nonthermal radio continuum with the cool component of the interstellar medium; the origin and effect of hot galactic halos; the absorption line systems seen in distant quasars; and the effect of galactic collisions.

Correlations of External Landmarks With Internal Structures of the Temporal Bone.

Science.gov (United States)

Piromchai, Patorn; Wijewickrema, Sudanthi; Smeds, Henrik; Kennedy, Gregor; O'Leary, Stephen

2015-09-01

The internal anatomy of a temporal bone could be inferred from external landmarks. Mastoid surgery is an important skill that ENT surgeons need to acquire. Surgeons commonly use CT scans as a guide to understanding anatomical variations before surgery. Conversely, in cases where CT scans are not available, or in the temporal bone laboratory where residents are usually not provided with CT scans, it would be beneficial if the internal anatomy of a temporal bone could be inferred from external landmarks. We explored correlations between internal anatomical variations and metrics established to quantify the position of external landmarks that are commonly exposed in the operating room, or the temporal bone laboratory, before commencement of drilling. Mathematical models were developed to predict internal anatomy based on external structures. From an operating room view, the distances between the following external landmarks were observed to have statistically significant correlations with the internal anatomy of a temporal bone: temporal line, external auditory canal, mastoid tip, occipitomastoid suture, and Henle's spine. These structures can be used to infer a low lying dura mater (p = 0.002), an anteriorly located sigmoid sinus (p = 0.006), and a more lateral course of the facial nerve (p external landmarks. The distances between these two landmarks and the operating view external structures were able to further infer the laterality of the facial nerve (p internal structures with a high level of accuracy: the distance from the sigmoid sinus to the posterior external auditory canal (p external landmarks found on the temporal bone. These relationships could be used as a guideline to predict challenges during drilling and choosing appropriate temporal bones for dissection.

Book Review: EU External Relations Law: Text, Cases and Materials

Directory of Open Access Journals (Sweden)

Graham Butler

2014-06-01

Full Text Available This latest textbook contributing to the field of EU external relations law is unique in that it is the first such book in the post-Treaty of Lisbon environment to take a wide-angled look on as many aspects of the growing area as it continues to develop within the legal parameters as set by the Treaties, and it is suitably placed to become the core text for teaching this expanding EU policy field. In their book, EU External Relations Law: Text, Cases and Materials, Van Vooren and Wessel seek to fill the gap in up-to-date literature from a legal standpoint in the field of external relations of the EU, with a book that is suitable for delivery as a core textbook for students of all levels. Their analysis covering fifteen long chapters offers the reader a comprehensive insight into the world of EU external relations law, and allows for a thoroughly better understanding of all the encapsulated issues that are at play.

Promoting justice or perpetuating prejudice? Interrupting external motivation in multicultural training.

Science.gov (United States)

Gushue, George V; Hinman, Kimberly A

2018-01-01

The effects of responding to social pressure (external motivation) are short-lived. Multicultural training, however, seeks to promote change in students and trainees that will be transformative and long-lasting. To this end, understanding the motivational factors that inform training is key. The present study was an investigation of the factors underlying external motivation to respond without prejudice for White individuals from the perspective of Higgins's regulatory focus (promotion and prevention) and regulatory mode (assessment and locomotion) theories. The results indicate that locomotion was negatively associated with external motivation to respond without prejudice, while assessment and prevention were positively associated with external motivation. Taken together, findings highlight the importance of cultivating locomotion (action oriented) motivation and inhibiting prevention (loss oriented) and assessment (preoccupation with finding the correct answer) motivations in multicultural training. Implications for training, effective action for justice, and future research are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A validation study of the Brief Irrational Thoughts Inventory

NARCIS (Netherlands)

Hoogsteder, L.M.; Wissink, I.B.; Stams, G.J.J.M.; van Horn, J.E.; Hendriks, J.

2014-01-01

This study examines the reliability and validity of the "Brief Irrational Thoughts Inventory" (BITI) in a sample of 256 justice-involved youths. The BITI is a questionnaire used to determine the nature and severity of irrational thoughts related to aggressive (externalizing), sub-assertive

60 GHz Antenna Diagnostics from Planar Near Field Antenna Measurement Without External Frequency Conversion

DEFF Research Database (Denmark)

Popa, Paula Irina; Pivnenko, Sergey; Breinbjerg, Olav

2015-01-01

,J.M. Nielsen, O. Breinbjerg, 60 GHz Antenna Measurement Setup using a VNA without External Frequency Conversion,36th Annual Symposium of the Antenna Measurement Technique Association ,October 12-17,Tucson, Arizona, 2014]. In this work we extend the validation of this 60 GHz planar near-field (PNF) set...

Mapping the MMPI-2-RF Substantive Scales Onto Internalizing, Externalizing, and Thought Dysfunction Dimensions in a Forensic Inpatient Setting.

Science.gov (United States)

Romero, Isabella E; Toorabally, Nasreen; Burchett, Danielle; Tarescavage, Anthony M; Glassmire, David M

2017-01-01

Contemporary models of psychopathology-encompassing internalizing, externalizing, and thought dysfunction factors-have gained significant support. Although research indicates the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008 /2011) measures these domains of psychopathology, this study addresses extant limitations in MMPI-2-RF diagnostic validity research by examining associations between all MMPI-2-RF substantive scales and broad dichotomous indicators of internalizing, externalizing, and thought dysfunction diagnoses in a sample of 1,110 forensic inpatients. Comparing those with and without internalizing diagnoses, notable effects were observed for Negative Emotionality/Neuroticism-Revised (NEGE-r), Emotional/Internalizing Dysfunction (EID), Dysfunctional Negative Emotions (RC7), Demoralization (RCd), and several other internalizing and somatic/cognitive scales. Comparing those with and without thought dysfunction diagnoses, the largest hypothesized differences occurred for Thought Dysfunction (THD), Aberrant Experiences (RC8), and Psychoticism-Revised (PSYC-r), although unanticipated differences were observed on internalizing and interpersonal scales, likely reflecting the high prevalence of internalizing dysfunction in forensic inpatients not experiencing thought dysfunction. Comparing those with and without externalizing diagnoses, the largest effects were for Substance Abuse (SUB), Antisocial Behavior (RC4), Behavioral/Externalizing Dysfunction (BXD), Juvenile Conduct Problems (JCP), and Disconstraint-Revised (DISC-r). Multivariate models evidenced similar results. Findings support the construct validity of MMPI-2-RF scales as measures of internalizing, thought, and externalizing dysfunction.

Does external technology acquisition determine export performance? Evidence from Chinese manufacturing firms

DEFF Research Database (Denmark)

Wang, Yuandi; Cao, Wei; Zhou, Zhao

2013-01-01

understanding of the determinants of export performance by examining the impact of the inter-organizational dimension of innovation strategy to export performance, which has been ignored in the prevailing “strategy tripod” perspective of exporting research. This study is based on a sample of 141 Chinese...... indigenous manufacturing firms that engaged in inward technology licensing between 2000 and 2003. The empirical results indicate that external technology acquisitions positively influence Chinese firms’ export performance. Moreover the exporting performance of using external technology varies depending...

Validating the passenger traffic model for Copenhagen

DEFF Research Database (Denmark)

Overgård, Christian Hansen; VUK, Goran

2006-01-01

The paper presents a comprehensive validation procedure for the passenger traffic model for Copenhagen based on external data from the Danish national travel survey and traffic counts. The model was validated for the years 2000 to 2004, with 2004 being of particular interest because the Copenhagen...... matched the observed traffic better than those of the transit assignment model. With respect to the metro forecasts, the model over-predicts metro passenger flows by 10% to 50%. The wide range of findings from the project resulted in two actions. First, a project was started in January 2005 to upgrade...

Preliminary Validity of the Eyberg Child Behavior Inventory With Filipino Immigrant Parents.

Science.gov (United States)

Coffey, Dean M; Javier, Joyce R; Schrager, Sheree M

Filipinos are an understudied minority affected by significant behavioral health disparities. We evaluate evidence for the reliability, construct validity, and convergent validity of the Eyberg Child Behavior Inventory (ECBI) in 6- to 12- year old Filipino children ( N = 23). ECBI scores demonstrated high internal consistency, supporting a single-factor model (pre-intervention α =.91; post-intervention α =.95). Results document convergent validity with the Child Behavior Checklist Externalizing scale at pretest ( r = .54, p Filipino children.

Investigating the relationship between the practice of pharmaceutical care, construed external image, organizational identification, and job turnover intention of community pharmacists.

Science.gov (United States)

O'Neill, Jessica L; Gaither, Caroline A

2007-12-01

Pharmacy employers are being challenged to recruit and retain qualified employees. Our study hypothesized that pharmacists who practice pharmaceutical care have an attractive construed external image (how employees think outsiders view their organization), which strengthens their organizational identification (perceptions of oneness with or belongingness to the organization) and decreases job turnover intention (thoughts of quitting/searching for another job). A 7-page questionnaire was mailed to the homes of a random sample of 759 licensed pharmacists practicing in the United States. Participants had the option of returning the completed survey via postal mail or a Web site. The study variables were measured with previously validated scales. Structural equation modeling with latent variables evaluated the hypothesized relationships. Several demographic variables were included. Responses were received from 252 subjects (33%); 121 were community pharmacists. As hypothesized, organizational identification and job turnover intention were significantly related (B=-0.24) as well as construed external image and organizational identification (B=0.41). The practice of pharmaceutical care and construed external image were not significantly correlated (B=0.10). Although not hypothesized, construed external image was directly related to job turnover intention (B=-0.25). The effects of the practice of pharmaceutical care on job turnover intention were mediated through organizational identification. Position had significant effects. One additional benefit to the practice of pharmaceutical care may be strengthened organizational identification. Pharmacists' perception of the image of their employer may increase organizational identification and decrease job turnover intention. An understanding of the organizational identification of pharmacists would be useful in decreasing job turnover intention. Given the current demand for pharmacists, this is a worthwhile endeavor. Future

Understanding the dynamics of correct and error responses in free recall: evidence from externalized free recall.

Science.gov (United States)

Unsworth, Nash; Brewer, Gene A; Spillers, Gregory J

2010-06-01

The dynamics of correct and error responses in a variant of delayed free recall were examined in the present study. In the externalized free recall paradigm, participants were presented with lists of words and were instructed to subsequently recall not only the words that they could remember from the most recently presented list, but also any other words that came to mind during the recall period. Externalized free recall is useful for elucidating both sampling and postretrieval editing processes, thereby yielding more accurate estimates of the total number of error responses, which are typically sampled and subsequently edited during free recall. The results indicated that the participants generally sampled correct items early in the recall period and then transitioned to sampling more erroneous responses. Furthermore, the participants generally terminated their search after sampling too many errors. An examination of editing processes suggested that the participants were quite good at identifying errors, but this varied systematically on the basis of a number of factors. The results from the present study are framed in terms of generate-edit models of free recall.

The Changing Role of External Stakeholders: From Imaginary Friends to Effective Actors or Non-Interfering Friends

Science.gov (United States)

Magalhães, António; Veiga, Amélia; Amaral, Alberto

2018-01-01

Recent shifts in university governance have relied on increased autonomy. Within this context, the enhanced role attributed to governance boards at the expense of academic bodies and the role of external stakeholders has gained momentum. With the aim of understanding the extent of the influence of external stakeholders at the institutional level,…

Corporal Punishment and Youth Externalizing Behavior in Santiago, Chile

Science.gov (United States)

Ma, Julie; Han, Yoonsun; Grogan-Kaylor, Andrew; Delva, Jorge; Castillo, Marcela

2012-01-01

Objectives Corporal punishment is still widely practiced around the globe, despite the large body of child development research that substantiates its short- and long-term consequences. Within this context, this paper examined the relationship between parental use of corporal punishment and youth externalizing behavior with a Chilean sample to add to the growing empirical evidence concerning the potential relationship between increased corporal punishment and undesirable youth outcomes across cultures. Methods Analysis was based on 919 adolescents in Santiago, Chile. Descriptive and multivariate analyses were conducted to examine the extent to which parents’ use of corporal punishment and positive family measures were associated with youth externalizing behavior. Furthermore, the associations between self-reported externalizing behavior and infrequent, as well as frequent, use of corporal punishment were investigated to contribute to understanding how varying levels of parental use of corporal punishment were differently related to youth outcomes. Results Both mother’s and father’s use of corporal punishment were associated with greater youth externalizing behavior. Additionally, increases in positive parenting practices, such as parental warmth and family involvement, were met with decreases in youth externalizing behavior when controlling for youth demographics, family socioeconomic status, and parents’ use of corporal punishment. Finally, both infrequent and frequent use of corporal punishment were positively associated with higher youth problem behaviors, though frequent corporal punishment had a stronger relationship with externalizing behavior than did infrequent corporal punishment. Conclusions Parental use of corporal punishment, even on an occasional basis, is associated with greater externalizing behavior for youth while a warm and involving family environment may protect youth from serious problem behaviors. Therefore, findings of this study add

Mental states inside out: switching costs for emotional and nonemotional sentences that differ in internal and external focus.

Science.gov (United States)

Oosterwijk, Suzanne; Winkielman, Piotr; Pecher, Diane; Zeelenberg, René; Rotteveel, Mark; Fischer, Agneta H

2012-01-01

Mental states-such as thinking, remembering, or feeling angry, happy, or dizzy-have a clear internal component. We feel a certain way when we are in these states. These internal experiences may be simulated when people understand conceptual references to mental states. However, mental states can also be described from an "external" perspective, for example when referring to "smiling." In those cases, simulation of visible outside features may be more relevant for understanding. In a switching costs paradigm, we presented semantically unrelated sentences describing emotional and nonemotional mental states while manipulating their internal or external focus. The results show that switching costs occur when participants shift between sentences with an internal and an external focus. This suggests that different forms of simulation underlie understanding these sentences. In addition, these effects occurred for emotional and nonemotional mental states, suggesting that they are grounded in a similar way-through the process of simulation.

Validation and Adjustment of the Leipzig-Halifax Acute Aortic Dissection Type A Scorecard.

Science.gov (United States)

Mejàre-Berggren, Hanna; Olsson, Christian

2017-11-01

The novel Leipzig-Halifax (LH) scorecard for acute aortic dissection type A (AADA) stratifies risk of in-hospital death based on age, malperfusion syndromes, critical preoperative state, and coronary disease. The study aim was to externally validate the LH scorecard performance and, if adequate, propose adjustments. All consecutive AADA patients operated on from 1996 to 2016 (n = 509) were included to generate an external validation cohort. Variables related to in-hospital death were analyzed using univariable and multivariable analysis. The LH scorecard was applied to the validation cohort, compared with the original study, and variable selection was adjusted using validation measures for discrimination and calibration. In-hospital mortality rate was 17.7% (LH cohort 18.7%). Critical preoperative state and Penn class non-Aa were independent predictors (odds ratio [OR] 2.42 and 2.45, respectively) of in-hospital death. The LH scorecard was adjusted to include Penn class non-Aa, critical preoperative state, and coronary disease. Assessing discrimination, area under receiver operator characteristic curve for the LH scorecard was 0.61 versus 0.66 for the new scorecard (p = 0.086). In-hospital mortality rates in low-, medium-, and high-risk groups were 14%, 15%, and 48%, respectively (LH scorecard) versus 11%, 23%, and 43%, respectively (new scorecard), and goodness-of-fit p value was 0.01 versus 0.86, indicating better calibration by the new scorecard. A lower Akaike information criterion value, 464 versus 448, favored the new scorecard. Through adjustment of the LH scorecard after external validation, prognostic performance improved. Further validated, the LH scorecard could be a valuable risk prediction tool. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Teaching with External Representations: The Case of a Common Energy-Level Diagram in Chemistry

Science.gov (United States)

Orgill, MaryKay; Crippen, Kent

2010-01-01

Diagrams and figures play a central role in science and science education. Research has indicated that, when presented and used properly in a classroom setting, these external representations can contribute to students' understanding of scientific concepts; however, it is apparent that students do not always use, understand, interpret, or value…

Validation of the Spanish Version of the COPD-Q Questionnaire on COPD Knowledge.

Science.gov (United States)

Puente-Maestu, Luis; Chancafe-Morgan, Jorge; Calle, Myriam; Rodríguez-Hermosa, Juan L; Malo de Molina, Rosa; Ortega-González, Ángel; Fuster, Antonia; Márquez-Martín, Eduardo; Marcos, Pedro J; Ramírez, Laura; Ray, Shaunta'; Franks, Andrea

2016-01-01

Although recognition of the importance of educating chronic obstructive pulmonary disease (COPD) patients has grown in recent years, their understanding of this disease is not being measured due to a lack of specific instruments. The aim of this study was to validate the COPD-Q questionnaire, a 13-item instrument for determining COPD knowledge. The COPD-Q was translated and backtranslated, and subsequently submitted to logic and content validation by a group of COPD experts and 8 COPD patients. Reliability was studied in an independent group of 59 patients with severe COPD seen in the pulmonology ward or clinics of 6 hospitals in Spain (Andalusia, Baleares, Castilla-La Mancha, Galicia and Madrid). This sample was also used for other internal and external validations. The mean age of the group was approximately 70 years and their health awareness was low-to-medium. The number of correct answers was 8.3 (standard deviation: 1.9), median 8, range 3-13. Floor and ceiling effects were 0% and 1.5%, respectively. Internal consistency of the questionnaire was good (Cronbach's alpha=0.85) and reliability was also high, with a kappa coefficient >0.6 for all items and an intraclass correlation efficient of 0.84 for the total score. The 13-item COPD-Q is a valid, applicable and reliable instrument for determining patients' knowledge of COPD. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.

[External cephalic version].

Science.gov (United States)

Navarro-Santana, B; Duarez-Coronado, M; Plaza-Arranz, J

2016-08-01

To analyze the rate of successful external cephalic versions in our center and caesarean sections that would be avoided with the use of external cephalic versions. From January 2012 to March 2016 external cephalic versions carried out at our center, which were a total of 52. We collected data about female age, gestational age at the time of the external cephalic version, maternal body mass index (BMI), fetal variety and situation, fetal weight, parity, location of the placenta, amniotic fluid index (ILA), tocolysis, analgesia, and newborn weight at birth, minor adverse effects (dizziness, hypotension and maternal pain) and major adverse effects (tachycardia, bradycardia, decelerations and emergency cesarean section). 45% of the versions were unsuccessful and 55% were successful. The percentage of successful vaginal delivery in versions was 84% (4% were instrumental) and 15% of caesarean sections. With respect to the variables studied, only significant differences in birth weight were found; suggesting that birth weight it is related to the outcome of external cephalic version. Probably we did not find significant differences due to the number of patients studied. For women with breech presentation, we recommend external cephalic version before the expectant management or performing a cesarean section. The external cephalic version increases the proportion of fetuses in cephalic presentation and also decreases the rate of caesarean sections.

Aetiology of thrombosed external haemorrhoids: a questionnaire study

OpenAIRE

Gebbensleben, Ole; Hilger, York; Rohde, Henning

2009-01-01

Abstract Background It is important to better understand the aetiology of thrombosed external haemorrhoids (TEH) because recurrence rates are high, prophylaxis is unknown, and optimal therapy is highly debated. Findings We conducted a questionnaire study of individuals with and without TEH. Aetiology was studied by comparison of answers to a questionnaire given to individuals with and without TEH concerning demography, history, and published aetiologic hypotheses. Participants were evaluated ...

Bureaucratic discretion and alternative teacher certification: understanding program variation in Missouri.

Directory of Open Access Journals (Sweden)

Ethan B. Heinen

2007-06-01

Full Text Available Alternative teacher certification literature has contributed significantly to our understanding of this approach to teacher preparation. However, this literature has more often than not treated alternative teacher certification programs (ATCPs as a black box, thus ignoring program heterogeneity. The present study examines how and why five ATCPs in Missouri have evolved in different ways. To understand this variation and its potential significance for researchers and practitioners, we use political science literature on bureaucratic discretion to understand programs' varied responses within the same state policy context. Using a multiple case study design, we present two key findings. First, external factors such as the state's regulatory approach, programs' relationships with school districts, and programs' relationship with external partners shape program coordinators' perceptions of their discretionary authority. Second, within an environment of limited regulation, programs responded to these external factors in ways that shaped programs in dramatically different ways. These approaches ranged from formal partnerships with large urban school districts and philanthropic funders to alternative certification programs that were at least partially blended with existing undergraduate and post baccalaureate teacher preparation programs. In our discussion, we explore how state attempts to widen the discretionary space between the rules may have allowed external interests (e.g., school districts, and external funders to backfill that space in ways that limit the potential for programs to provide high quality preparation experiences. This study explores these consequences and trade offs in order to inform policy makers and practitioners who are concerned with fostering innovative and creative ways to prepare high quality teachers.

External radiation surveillance

Energy Technology Data Exchange (ETDEWEB)

Antonio, E.J.

1995-06-01

This section of the 1994 Hanford Site Environmental Report describes how external radiation was measured, how surveys were performed, and the results of these measurements and surveys. External radiation exposure rates were measured at locations on and off the Hanford Site using thermoluminescent dosimeters (TLD). External radiation and contamination surveys were also performed with portable radiation survey instruments at locations on and around the Hanford Site.

External radiation surveillance

International Nuclear Information System (INIS)

Antonio, E.J.

1995-01-01

This section of the 1994 Hanford Site Environmental Report describes how external radiation was measured, how surveys were performed, and the results of these measurements and surveys. External radiation exposure rates were measured at locations on and off the Hanford Site using thermoluminescent dosimeters (TLD). External radiation and contamination surveys were also performed with portable radiation survey instruments at locations on and around the Hanford Site

Human Factors methods concerning integrated validation of nuclear power plant control rooms; Metodutveckling foer integrerad validering

Energy Technology Data Exchange (ETDEWEB)

Oskarsson, Per-Anders; Johansson, Bjoern J.E.; Gonzalez, Natalia (Swedish Defence Research Agency, Information Systems, Linkoeping (Sweden))

2010-02-15

The frame of reference for this work was existing recommendations and instructions from the NPP area, experiences from the review of the Turbic Validation and experiences from system validations performed at the Swedish Armed Forces, e.g. concerning military control rooms and fighter pilots. These enterprises are characterized by complex systems in extreme environments, often with high risks, where human error can lead to serious consequences. A focus group has been performed with representatives responsible for Human Factors issues from all Swedish NPP:s. The questions that were discussed were, among other things, for whom an integrated validation (IV) is performed and its purpose, what should be included in an IV, the comparison with baseline measures, the design process, the role of SSM, which methods of measurement should be used, and how the methods are affected of changes in the control room. The report brings different questions to discussion concerning the validation process. Supplementary methods of measurement for integrated validation are discussed, e.g. dynamic, psychophysiological, and qualitative methods for identification of problems. Supplementary methods for statistical analysis are presented. The study points out a number of deficiencies in the validation process, e.g. the need of common guidelines for validation and design, criteria for different types of measurements, clarification of the role of SSM, and recommendations for the responsibility of external participants in the validation process. The authors propose 12 measures for taking care of the identified problems

The correlation between internal and external markers for abdominal tumors: Implications for respiratory gating

International Nuclear Information System (INIS)

Gierga, David P.; Brewer, Johanna; Sharp, Gregory C.; Betke, Margrit; Willett, Christopher G.; Chen, George T.Y.

2005-01-01

Purpose: The correlation of the respiratory motion of external patient markers and abdominal tumors was examined. Data of this type are important for image-guided therapy techniques, such as respiratory gating, that monitor the movement of external fiducials. Methods and Materials: Fluoroscopy sessions for 4 patients with internal, radiopaque tumor fiducial clips were analyzed by computer vision techniques. The motion of the internal clips and the external markers placed on the patient's abdominal skin surface were quantified and correlated. Results: In general, the motion of the tumor and external markers were well correlated. The maximum amount of peak-to-peak craniocaudal tumor motion was 2.5 cm. The ratio of tumor motion to external-marker motion ranged from 0.85 to 7.1. The variation in tumor position for a given external-marker position ranged from 2 to 9 mm. The period of the breathing cycle ranged from 2.7 to 4.5 seconds, and the frequency patterns for both the tumor and the external markers were similar. Conclusions: Although tumor motion generally correlated well with external fiducial marker motion, relatively large underlying tumor motion can occur compared with external-marker motion and variations in the tumor position for a given marker position. Treatment margins should be determined on the basis of a detailed understanding of tumor motion, as opposed to relying only on external-marker information

Validation of multisource electronic health record data: an application to blood transfusion data.

Science.gov (United States)

Hoeven, Loan R van; Bruijne, Martine C de; Kemper, Peter F; Koopman, Maria M W; Rondeel, Jan M M; Leyte, Anja; Koffijberg, Hendrik; Janssen, Mart P; Roes, Kit C B

2017-07-14

Although data from electronic health records (EHR) are often used for research purposes, systematic validation of these data prior to their use is not standard practice. Existing validation frameworks discuss validity concepts without translating these into practical implementation steps or addressing the potential influence of linking multiple sources. Therefore we developed a practical approach for validating routinely collected data from multiple sources and to apply it to a blood transfusion data warehouse to evaluate the usability in practice. The approach consists of identifying existing validation frameworks for EHR data or linked data, selecting validity concepts from these frameworks and establishing quantifiable validity outcomes for each concept. The approach distinguishes external validation concepts (e.g. concordance with external reports, previous literature and expert feedback) and internal consistency concepts which use expected associations within the dataset itself (e.g. completeness, uniformity and plausibility). In an example case, the selected concepts were applied to a transfusion dataset and specified in more detail. Application of the approach to a transfusion dataset resulted in a structured overview of data validity aspects. This allowed improvement of these aspects through further processing of the data and in some cases adjustment of the data extraction. For example, the proportion of transfused products that could not be linked to the corresponding issued products initially was 2.2% but could be improved by adjusting data extraction criteria to 0.17%. This stepwise approach for validating linked multisource data provides a basis for evaluating data quality and enhancing interpretation. When the process of data validation is adopted more broadly, this contributes to increased transparency and greater reliability of research based on routinely collected electronic health records.

Influence of Internal and External Noise on Spontaneous Visuomotor Synchronization.

Science.gov (United States)

Varlet, Manuel; Schmidt, R C; Richardson, Michael J

2016-01-01

Historically, movement noise or variability is considered to be an undesirable property of biological motor systems. In particular, noise is typically assumed to degrade the emergence and stability of rhythmic motor synchronization. Recently, however, it has been suggested that small levels of noise might actually improve the functioning of motor systems and facilitate their adaptation to environmental events. Here, the authors investigated whether noise can facilitate spontaneous rhythmic visuomotor synchronization. They examined the influence of internal noise in the rhythmic limb movements of participants and external noise in the movement of an oscillating visual stimulus on the occurrence of spontaneous synchronization. By indexing the natural frequency variability of participants and manipulating the frequency variability of the visual stimulus, the authors demonstrated that both internal and external noise degrade synchronization when the participants' and stimulus movement frequencies are similar, but can actually facilitate synchronization when the frequencies are different. Furthermore, the two kinds of noise interact with each other. Internal noise facilitates synchronization only when external noise is minimal and vice versa. Too much internal and external noise together degrades synchronization. These findings open new perspectives for better understanding the role of noise in human rhythmic coordination.

Computation of External Quality Factors for RF Structures by Means of Model Order Reduction and a Perturbation Approach

CERN Document Server

Flisgen, Thomas; van Rienen, Ursula

2016-01-01

External quality factors are significant quantities to describe losses via waveguide ports in radio frequency resonators. The current contribution presents a novel approach to determine external quality factors by means of a two-step procedure: First, a state-space model for the lossless radio frequency structure is generated and its model order is reduced. Subsequently, a perturbation method is applied on the reduced model so that external losses are accounted for. The advantage of this approach results from the fact that the challenges in dealing with lossy systems are shifted to the reduced order model. This significantly saves computational costs. The present paper provides a short overview on existing methods to compute external quality factors. Then, the novel approach is introduced and validated in terms of accuracy and computational time by means of commercial software.

The Development and Piloting of Parallel Scales Measuring External and Internal HIV and Tuberculosis Stigma Among Healthcare Workers in the Free State Province, South Africa.

Science.gov (United States)

Wouters, Edwin; Rau, Asta; Engelbrecht, Michelle; Uebel, Kerry; Siegel, Jacob; Masquillier, Caroline; Kigozi, Gladys; Sommerland, Nina; Yassi, Annalee

2016-05-15

The dual burden of tuberculosis and human immunodeficiency virus (HIV) is severely impacting the South African healthcare workforce. However, the use of on-site occupational health services is hampered by stigma among the healthcare workforce. The success of stigma-reduction interventions is difficult to evaluate because of a dearth of appropriate scientific tools to measure stigma in this specific professional setting. The current pilot study aimed to develop and test a range of scales measuring different aspects of stigma-internal and external stigma toward tuberculosis as well as HIV-in a South African healthcare setting. The study employed data of a sample of 200 staff members of a large hospital in Bloemfontein, South Africa. Confirmatory factor analysis produced 7 scales, displaying internal construct validity: (1) colleagues' external HIV stigma, (2) colleagues' actions against external HIV stigma, (3) respondent's external HIV stigma, (4) respondent's internal HIV stigma, (5) colleagues' external tuberculosis stigma, (6) respondent's external tuberculosis stigma, and (7) respondent's internal tuberculosis stigma. Subsequent analyses (reliability analysis, structural equation modeling) demonstrated that the scales displayed good psychometric properties in terms of reliability and external construct validity. The study outcomes support the use of the developed scales as a valid and reliable means to measure levels of tuberculosis- and HIV-related stigma among the healthcare workforce in a resource-limited context. Future studies should build on these findings to fine-tune the instruments and apply them to larger study populations across a range of different resource-limited healthcare settings with high HIV and tuberculosis prevalence. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

External Influences on an Internal Process: Supporting Preservice Teacher Research

Science.gov (United States)

Schulte, Ann; Klipfel, Lyndsay Halpin

2016-01-01

In an effort to better understand how participating in teacher research as a student teacher compares to conducting it as a practicing teacher, a teacher educator and her former teacher education student engaged in a collaborative dialogue. They focus their reflections in this article on the impact of external forces on the process of teacher…

Method Validation Procedure in Gamma Spectroscopy Laboratory

International Nuclear Information System (INIS)

El Samad, O.; Baydoun, R.

2008-01-01

The present work describes the methodology followed for the application of ISO 17025 standards in gamma spectroscopy laboratory at the Lebanese Atomic Energy Commission including the management and technical requirements. A set of documents, written procedures and records were prepared to achieve the management part. The technical requirements, internal method validation was applied through the estimation of trueness, repeatability , minimum detectable activity and combined uncertainty, participation in IAEA proficiency tests assure the external method validation, specially that the gamma spectroscopy lab is a member of ALMERA network (Analytical Laboratories for the Measurements of Environmental Radioactivity). Some of these results are presented in this paper. (author)

External validation of the ITA.LI.CA prognostic system for patients with hepatocellular carcinoma: A multicenter cohort study.

Science.gov (United States)

Borzio, Mauro; Dionigi, Elena; Rossini, Angelo; Marignani, Massimo; Sacco, Rodolfo; De Sio, Ilario; Bertolini, Emanuela; Francica, Giampiero; Giacomin, Anna; Parisi, Giancarlo; Vicari, Susanna; Toldi, Anna; Salmi, Andrea; Boccia, Sergio; Mitra, Mario; Fornari, Fabio

2017-11-22

Several staging systems for hepatocellular carcinoma (HCC) have been developed. The Barcelona Clinic Liver Cancer staging system is considered the best in predicting survival, although limitations have emerged. Recently, the Italian Liver Cancer (ITA.LI.CA) prognostic system, integrating ITA.LI.CA tumor staging (stages 0, A, B1-3, C) with the Child-Turcotte-Pugh score, Eastern Cooperative Oncology Group performance status, and alpha-fetoprotein with a strong ability to predict survival, was proposed. The aim of our study was to provide an external validation of the ITA.LI.CA system in an independent real-life occidental cohort of HCCs. From September 2008 to April 2016, 1,508 patients with cirrhosis and incident HCC were consecutively enrolled in 27 Italian institutions. Clinical, tumor, and treatment-related variables were collected, and patients were stratified according to scores of the Barcelona Clinic Liver Cancer system, ITA.LI.CA prognostic system, Hong Kong Liver Cancer system, Cancer of the Liver Italian Program, Japanese Integrated System, and model to estimate survival in ambulatory patients with hepatocellular carcinoma. Harrell's C-index, Akaike information criterion, and likelihood-ratio test were used to compare the predictive ability of the different systems. A subgroup analysis for treatment category (curative versus palliative) was performed. Median follow-up was 44 months (interquartile range, 23-63 months), and median overall survival was 34 months (interquartile range, 13-82 months). Median age was 71 years, and patients were mainly male individuals and hepatitis C virus carriers. According to ITA.LI.CA tumor staging, 246 patients were in stage 0, 472 were in stage A, 657 were in stages B1/3, and 133 were in stage C. The ITA.LI.CA prognostic system showed the best discriminatory ability (C-index = 0.77) and monotonicity of gradients compared to other systems, and its superiority was also confirmed after stratification for treatment strategy

The pursuit of understanding: A study of exemplary high school students' conceptions of knowledge validation in science and history

Science.gov (United States)

Boix Mansilla, Veronica Maria

The study presented examined 16 award-winning high school students' beliefs about the criteria by which scientific theories and historical narratives are deemed trustworthy. It sought to (a) describe such beliefs as students reasoned within each discipline; (b) examine the degree to which such beliefs were organized as coherent systems of thought; and (c) explore the relationship between students' beliefs and their prior disciplinary research experience. Students were multiple-year award-winners at the Massachusetts Science Fair and the National History Day---two pre-collegiate State-level competitions. Two consecutive semi-structured interviews invited students to assess and enhance the trustworthiness of competing accounts of genetic inheritance and the Holocaust in science and history respectively. A combined qualitative and quantitative data analysis yielded the following results: (a) Students valued three standards of acceptability that were common across disciplines: e.g. empirical strength, explanatory power and formal and presentational strength. However, when reasoning within each discipline they tended to define each standard in disciplinary-specific ways. Students also valued standards of acceptability that were not shared across disciplines: i.e., external validity in science and human understanding in history. (b) In science, three distinct epistemological orientations were identified---i.e., "faith in method," "trusting the scientific community" and "working against error." In history students held two distinct epistemologies---i.e., "reproducing the past" and "organizing the past". Students' epistemological orientations tended to operate as collections of mutually supporting ideas about what renders a theory or a narrative acceptable. (c) Contrary to the standard position to date in the literature on epistemological beliefs, results revealed that students' research training in a particular discipline (e.g., science or history) was strongly related to

A geography of moral hazard: sources and sinks of motor-vehicle commuting externalities.

Science.gov (United States)

Yiannakoulias, Niko; Bland, Widmer; Scott, Darren M

2014-09-01

Motor-vehicles are responsible for harms to health that are not directly experienced by individual drivers - such as air pollution and risk of injury to pedestrians. In addition to their direct effects on health, these harms also represent a moral hazard since drivers are not required to consider their effects as part of their decision to drive. We describe an approach for estimating sources of motor-vehicle commuter externalities as a means of understanding the geography of moral hazard, and in particular, the spatial displacement of negative health externalities associated with motor-vehicle commuting. This approach models motor-vehicle commuter traffic flow by trip origin for small geographic areas within the City of Toronto, Ontario. We find that most health-related externalities associated with motor-vehicle commuters are not locally generated, with a large share coming from outside Toronto. Low income is associated with externalities originating outside the municipal boundary, but not with locally sourced externalities. We discuss the impact of geographical moral hazard on the agency of citizens as well as policy options aimed at addressing motor-vehicle externalities. Copyright © 2014 Elsevier Ltd. All rights reserved.

International External Validation Study of the 2014 European Society of Cardiology Guidelines on Sudden Cardiac Death Prevention in Hypertrophic Cardiomyopathy (EVIDENCE-HCM).

Science.gov (United States)

O'Mahony, Constantinos; Jichi, Fatima; Ommen, Steve R; Christiaans, Imke; Arbustini, Eloisa; Garcia-Pavia, Pablo; Cecchi, Franco; Olivotto, Iacopo; Kitaoka, Hiroaki; Gotsman, Israel; Carr-White, Gerald; Mogensen, Jens; Antoniades, Loizos; Mohiddin, Saidi A; Maurer, Mathew S; Tang, Hak Chiaw; Geske, Jeffrey B; Siontis, Konstantinos C; Mahmoud, Karim D; Vermeer, Alexa; Wilde, Arthur; Favalli, Valentina; Guttmann, Oliver P; Gallego-Delgado, Maria; Dominguez, Fernando; Tanini, Ilaria; Kubo, Toru; Keren, Andre; Bueser, Teofila; Waters, Sarah; Issa, Issa F; Malcolmson, James; Burns, Tom; Sekhri, Neha; Hoeger, Christopher W; Omar, Rumana Z; Elliott, Perry M

2018-03-06

Identification of people with hypertrophic cardiomyopathy (HCM) who are at risk of sudden cardiac death (SCD) and require a prophylactic implantable cardioverter defibrillator is challenging. In 2014, the European Society of Cardiology proposed a new risk stratification method based on a risk prediction model (HCM Risk-SCD) that estimates the 5-year risk of SCD. The aim was to externally validate the 2014 European Society of Cardiology recommendations in a geographically diverse cohort of patients recruited from the United States, Europe, the Middle East, and Asia. This was an observational, retrospective, longitudinal cohort study. The cohort consisted of 3703 patients. Seventy three (2%) patients reached the SCD end point within 5 years of follow-up (5-year incidence, 2.4% [95% confidence interval {CI}, 1.9-3.0]). The validation study revealed a calibration slope of 1.02 (95% CI, 0.93-1.12), C-index of 0.70 (95% CI, 0.68-0.72), and D-statistic of 1.17 (95% CI, 1.05-1.29). In a complete case analysis (n= 2147; 44 SCD end points at 5 years), patients with a predicted 5-year risk of <4% (n=1524; 71%) had an observed 5-year SCD incidence of 1.4% (95% CI, 0.8-2.2); patients with a predicted risk of ≥6% (n=297; 14%) had an observed SCD incidence of 8.9% (95% CI, 5.96-13.1) at 5 years. For every 13 (297/23) implantable cardioverter defibrillator implantations in patients with an estimated 5-year SCD risk ≥6%, 1 patient can potentially be saved from SCD. This study confirms that the HCM Risk-SCD model provides accurate prognostic information that can be used to target implantable cardioverter defibrillator therapy in patients at the highest risk of SCD. © 2017 American Heart Association, Inc.

Unavailability of thymidine kinase does not preclude the use of German comprehensive prognostic index: results of an external validation analysis in early chronic lymphocytic leukemia and comparison with MD Anderson Cancer Center model.

Science.gov (United States)

Molica, Stefano; Giannarelli, Diana; Mirabelli, Rosanna; Levato, Luciano; Russo, Antonio; Linardi, Maria; Gentile, Massimo; Morabito, Fortunato

2016-01-01

A comprehensive prognostic index that includes clinical (i.e., age, sex, ECOG performance status), serum (i.e., ß2-microglobulin, thymidine kinase [TK]), and molecular (i.e., IGVH mutational status, del 17p, del 11q) markers developed by the German CLL Study Group (GCLLSG) was externally validated in a prospective, community-based cohort consisting of 338 patients with early chronic lymphocytic leukemia (CLL) using as endpoint the time to first treatment (TTFT). Because serum TK was not available, a slightly modified version of the model based on seven instead of eight prognostic variables was used. By German index, 62.9% of patients were scored as having low-risk CLL (score 0-2), whereas 37.1% had intermediate-risk CLL (score 3-5). This stratification translated into a significant difference in the TTFT [HR = 4.21; 95% C.I. (2.71-6.53); P reliability [HR = 2.73; 95% C.I. (1.79-4.17); P German score. The c-statistic of the MDACC model was 0.65 (range, 0.53-0.78) a level below that of the German index [0.71 (range, 0.60-0.82)] and below the accepted 0.7 threshold necessary to have value at the individual patient level. Results of this external comparative validation analysis strongly support the German score as the benchmark for comparison of any novel prognostic scheme aimed at evaluating the TTFT in patients with early CLL even when a modified version which does not include TK is utilized. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Stabilization of the external kink and the resistive wall mode

International Nuclear Information System (INIS)

Chu, M S; Okabayashi, M

2010-01-01

The pursuit of steady-state economic production of thermonuclear fusion energy has led to research on the stabilization of the external kink and the resistive wall mode. Advances in both experiment and theory, together with improvements in diagnostics, heating and feedback methods have led to substantial and steady progress in the understanding and stabilization of these instabilities. Many of the theory and experimental techniques and results that have been developed are useful not only for the stabilization of the resistive wall mode. They can also be used to improve the general performance of fusion confinement devices. The conceptual foundations and experimental results on the stabilization of the external kink and the resistive wall mode are reviewed. (topical review)

Estimating external causes of death in Thailand 1996-2009 based on the 2005 Verbal Autopsy study

Directory of Open Access Journals (Sweden)

Nuntaporn Klinjun

2014-12-01

Full Text Available This study aimed to develop models based on Verbal Autopsy (VA data and to estimate correct number of deaths from external causes in Thailand from 1996 to 2009. Logistic regression was used to create models of the three external causes of death classified by province, gender-age group and Vital registration (VR cause-location group. Receiver operating characteristic (ROC curves were used to validate the models by matching the number of reported deaths to the number of deaths predicted by the models. The models provided accurate prediction results, with false positive error rates 1.6%, 2.0% and 0.6% and sensitivities 73.8%, 46.3% and 62.0%, respectively. The results reveal that under-reporting of external causes of death increased over the 14-year period. Our statistical method confirms that the Thai 2005 VA data can be used to estimate external causes of death from VR report in Thailand to allow for the under-reporting rate.

Towards a kernel theory of external knowledge integration for high-tech firms: exploring a failed theory test

NARCIS (Netherlands)

Kraaijenbrink, Jeroen; Wijnhoven, Alphonsus B.J.M.; Groen, Arend J.

2007-01-01

Designing information systems (ISs) requires a thorough understanding of the organizational knowledge processes in which these systems are used. Although much is known about internal organizational knowledge processes, the understanding of external knowledge processes is less developed. Hence, this

The suitability of internal versus external successors

DEFF Research Database (Denmark)

Boyd, Britta; Royer, Susanne

2012-01-01

Understanding knowledge transfer in family firm succession is important for the survival of family firms. Previous research has begun to explore the suitability of internal versus external successor in family firms with regard to relevant knowledge types. This paper builds on the contingency model...... of family business succession in order to understand when family successors are preferred because of their family-specific experiential knowledge. A case study analysis from the German-Danish border region explores how a family firm has used internal successors for the last 12 successions. We argue...... that in industries where tacit knowledge forms the basis for competitive advantage, the use of internal successors can help family firms excel after a transition of power has occurred. Theoretical and practical implications are discussed to enhance the long-term perspective for family businesses....

External quality assurance system for antibiotic resistance in bacteria of animal origin in Europe (ARBAO-II), 2003

NARCIS (Netherlands)

Fo Wong, Lo D.M.A.; Hendriksen, R.S.; Mevius, D.J.; Veldman, K.T.; Aarestrup, F.M.

2006-01-01

Initiated in 2003 by the European Union, ARBAO-II aims to establish a monitoring of antimicrobial susceptibility among the veterinary laboratories in all European countries based on validated methodologies. This includes an external quality control system for the most important bacterial pathogens.

The Children's Social Understanding Scale: construction and validation of a parent-report measure for assessing individual differences in children's theories of mind.

Science.gov (United States)

Tahiroglu, Deniz; Moses, Louis J; Carlson, Stephanie M; Mahy, Caitlin E V; Olofson, Eric L; Sabbagh, Mark A

2014-11-01

Children's theory of mind (ToM) is typically measured with laboratory assessments of performance. Although these measures have generated a wealth of informative data concerning developmental progressions in ToM, they may be less useful as the sole source of information about individual differences in ToM and their relation to other facets of development. In the current research, we aimed to expand the repertoire of methods available for measuring ToM by developing and validating a parent-report ToM measure: the Children's Social Understanding Scale (CSUS). We present 3 studies assessing the psychometric properties of the CSUS. Study 1 describes item analysis, internal consistency, test-retest reliability, and relation of the scale to children's performance on laboratory ToM tasks. Study 2 presents cross-validation data for the scale in a different sample of preschool children with a different set of ToM tasks. Study 3 presents further validation data for the scale with a slightly older age group and a more advanced ToM task, while controlling for several other relevant cognitive abilities. The findings indicate that the CSUS is a reliable and valid measure of individual differences in children's ToM that may be of great value as a complement to standard ToM tasks in many different research contexts. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

THE IMPACT OF THE EXTERNALITIES GENERATED BY COMPETITIVE INTELLIGENCE

Directory of Open Access Journals (Sweden)

Moraru Adrian

2015-07-01

Full Text Available The goal of the paper named “The impact of the externalities generated by Competitive Intelligence” is to describe and understand how this activity works and behaves in a competitive environment, and what are the real cost of obtaining durable competitive advantages through a process such as Competitive Intelligence. This activity creates high added value on the market and the proper use of it can have a strong influence on increasing the competitiveness on the global economic environment and, therefore, increasing the efficiency inside those environments. On the other hand, externalities play a significant part in the economic welfare and, currently, in a globalized world, must be taken into consideration in order to obtain sustainable growth of the economy. As any other economic activity, Competitive Intelligence is also causing both positive and negative externalities. A thorough analysis of those externalities effects has to be made in order to understand how this process really works, and this paper aims to be the starting point of that analysis. Of course, further studies have to deepen each impact and obtain relevant results that will add up and draw more specific conclusions. This study’s conclusions, however, will reveal if this activity can work properly in every type of economy, regardless of its state of development. Since it represents a way to improve global competitiveness and, therefore, the market’s performance, the impact Competitive Intelligence is making on the whole economic system is a main parameter for establishing its real use. All in one, by being one of the most innovative ways to obtain competitive advantages through qualitative methods of analysis, the implementation of this process into the organizational culture of firms might change the way competitors choose to respond to one another’s actions. This research has taken into consideration both the macroeconomic and the microeconomic environment, using

Validation of NEPTUNE-CFD on ULPU-V experiments

Energy Technology Data Exchange (ETDEWEB)

Jamet, Mathieu, E-mail: mathieu.jamet@edf.fr; Lavieville, Jerome; Atkhen, Kresna; Mechitoua, Namane

2015-11-15

In-vessel retention (IVR) of molten corium through external cooling of the reactor pressure vessel is one possible means of severe accident mitigation for a class of nuclear power plants. The aim is to successfully terminate the progression of a core melt within the reactor vessel. The probability of success depends on the efficacy of the cooling strategy; hence one of the key aspects of an IVR demonstration relates to the heat removal capability through the vessel wall by convection and boiling in the external water flow. This is only possible if the in-vessel thermal loading is lower than the local critical heat flux expected along the outer wall of the vessel, which is in turn highly dependent on the flow characteristics between the vessel and the insulator. The NEPTUNE-CFD multiphase flow solver is used to obtain a better understanding at local scale of the thermal hydraulics involved in this situation. The validation of the NEPTUNE-CFD code on the ULPU-V facility experiments carried out at the University of California Santa Barbara is presented as a first attempt of using CFD codes at EDF to address such an issue. Two types of computation are performed. On the one hand, a steady state algorithm is used to compute natural circulation flow rates and differential pressures and, on the other, a transient algorithm computation reveals the oscillatory nature of the pressure data recorded in the ULPU facility. Several dominant frequencies are highlighted. In both cases, the CFD simulations reproduce reasonably well the experimental data for these quantities.

External validation of a biomarker and clinical prediction model for hospital mortality in acute respiratory distress syndrome.

Science.gov (United States)

Zhao, Zhiguo; Wickersham, Nancy; Kangelaris, Kirsten N; May, Addison K; Bernard, Gordon R; Matthay, Michael A; Calfee, Carolyn S; Koyama, Tatsuki; Ware, Lorraine B

2017-08-01

Mortality prediction in ARDS is important for prognostication and risk stratification. However, no prediction models have been independently validated. A combination of two biomarkers with age and APACHE III was superior in predicting mortality in the NHLBI ARDSNet ALVEOLI trial. We validated this prediction tool in two clinical trials and an observational cohort. The validation cohorts included 849 patients from the NHLBI ARDSNet Fluid and Catheter Treatment Trial (FACTT), 144 patients from a clinical trial of sivelestat for ARDS (STRIVE), and 545 ARDS patients from the VALID observational cohort study. To evaluate the performance of the prediction model, the area under the receiver operating characteristic curve (AUC), model discrimination, and calibration were assessed, and recalibration methods were applied. The biomarker/clinical prediction model performed well in all cohorts. Performance was better in the clinical trials with an AUC of 0.74 (95% CI 0.70-0.79) in FACTT, compared to 0.72 (95% CI 0.67-0.77) in VALID, a more heterogeneous observational cohort. The AUC was 0.73 (95% CI 0.70-0.76) when FACTT and VALID were combined. We validated a mortality prediction model for ARDS that includes age, APACHE III, surfactant protein D, and interleukin-8 in a variety of clinical settings. Although the model performance as measured by AUC was lower than in the original model derivation cohort, the biomarker/clinical model still performed well and may be useful for risk assessment for clinical trial enrollment, an issue of increasing importance as ARDS mortality declines, and better methods are needed for selection of the most severely ill patients for inclusion.

Women's experiences of participating in the early external cephalic version 2 trial.

Science.gov (United States)

Murray-Davis, Beth; Marion, Anya; Malott, Anne; Reitsma, Angela; Hutton, Eileen K

2012-03-01

The international, multicenter External Cephalic Version 2 (ECV2) Trial compared early external cephalic version at 34(0/7) to 35(6/7) weeks with that at greater than 37 weeks. A total of 1,543 women were randomized from 68 centers in 21 countries. The goal of this component of the trial was to understand women's views about participation in a research trial and timing of external cephalic version. A postpartum questionnaire was completed containing a 5-point Likert scale examining contact and availability of staff, choice of timing of external cephalic version, preference of randomization, convenience of participating, and overall satisfaction. Participants also completed two open-ended questions related to timing of external cephalic version and satisfaction with the trial. Descriptive statistics and content analysis were used to analyze data. A total of 1,458 women completed the questionnaire, of whom 86 percent said "yes"-they would participate in the trial again. Themes influencing decisions about participating were perceptions of the external cephalic version experience, preferred mode of delivery, preferred timing of external cephalic version, and perceptions of the effectiveness of external cephalic version and of the trial environment. Many participants preferred the early timing of the procedure offered through the trial because of perceived advantages of a smaller baby being easier to turn and the opportunity for repeat procedures. Women were positive about their participation in the trial. Early external cephalic version was preferred over the traditional timing as it was perceived to afford both physiologic and practical advantages. © 2012, Copyright the Authors. Journal compilation © 2012, Wiley Periodicals, Inc.

Validation of the Danish version of the McGill Ingestive Skills Assessment using classical test theory and the Rasch model

DEFF Research Database (Denmark)

Hansen, Tina; Lambert, Heather C; Faber, Jens

2012-01-01

Purpose: The study aimed to validate the Danish version of the Canadian the "McGill Ingestive Skills Assessment" (MISA-DK) for measuring dysphagia in frail elders. Method: One-hundred and ten consecutive older medical patients were recruited to the study. Reliability was assessed by internal...... consistency (Chronbach's alpha). External construct validity (convergent and known-groups validity) was evaluated against theoretical constructs assessing the complex concept of ingestive skills. Internal construct validity was tested using Rasch analysis. Results: High internal consistency reliability...... with Chronbach's alpha of 0.77-0.95 was evident. External construct validity was supported by expected high correlations with most of the constructs related to ingestive skills (r(s)¿=¿0.53 to r(s)¿=¿0.66). The MISA-DK discriminated significantly between known-groups. Fit to the Rasch model (x(2) (df)¿=¿12 (12...

Interpreting biomarker data from the COPHES/DEMOCOPHES twin projects: Using external exposure data to understand biomarker differences among countries

International Nuclear Information System (INIS)

Smolders, R.; Den Hond, E.; Koppen, G.; Govarts, E.; Willems, H.; Casteleyn, L.; Kolossa-Gehring, M.; Fiddicke, U.; Castaño, A.; Koch, H.M.; Angerer, J.; Esteban, M.; Sepai, O.; Exley, K.; Bloemen, L.; Horvat, M.; Knudsen, L.E.; Joas, A.; Joas, R.; Biot, P.

2015-01-01

In 2011 and 2012, the COPHES/DEMOCOPHES twin projects performed the first ever harmonized human biomonitoring survey in 17 European countries. In more than 1800 mother–child pairs, individual lifestyle data were collected and cadmium, cotinine and certain phthalate metabolites were measured in urine. Total mercury was determined in hair samples. While the main goal of the COPHES/DEMOCOPHES twin projects was to develop and test harmonized protocols and procedures, the goal of the current paper is to investigate whether the observed differences in biomarker values among the countries implementing DEMOCOPHES can be interpreted using information from external databases on environmental quality and lifestyle. In general, 13 countries having implemented DEMOCOPHES provided high-quality data from external sources that were relevant for interpretation purposes. However, some data were not available for reporting or were not in line with predefined specifications. Therefore, only part of the external information could be included in the statistical analyses. Nonetheless, there was a highly significant correlation between national levels of fish consumption and mercury in hair, the strength of antismoking legislation was significantly related to urinary cotinine levels, and we were able to show indications that also urinary cadmium levels were associated with environmental quality and food quality. These results again show the potential of biomonitoring data to provide added value for (the evaluation of) evidence-informed policy making. - Highlights: • External data was collected to interpret HBM data from DEMOCOPHES. • Hg in hair could be related to fish consumption across different countries. • Urinary cotinine was related to strictness of anti-smoking legislation. • Urinary Cd was borderline significantly related to air and food quality. • Lack of comparable data among countries hampered the analysis

Interpreting biomarker data from the COPHES/DEMOCOPHES twin projects: Using external exposure data to understand biomarker differences among countries

Energy Technology Data Exchange (ETDEWEB)

Smolders, R., E-mail: roel.smolders@vito.be [Flemish Institute of Technological Research (VITO), Environmental Risks and Health Unit, Boeretang 200, 2400 Mol (Belgium); Den Hond, E.; Koppen, G.; Govarts, E.; Willems, H. [Flemish Institute of Technological Research (VITO), Environmental Risks and Health Unit, Boeretang 200, 2400 Mol (Belgium); Casteleyn, L. [KU LEUVEN (Belgium); Kolossa-Gehring, M.; Fiddicke, U. [Federal Environment Agency (UBA) (Germany); Castaño, A. [Instituto de Salud Carlos III (Spain); Koch, H.M.; Angerer, J. [Institute for Prevention and Occupational Medicine of the German Social Accident Insurance - Institute of the Ruhr-Universität Bochum (IPA) (Germany); Esteban, M. [Instituto de Salud Carlos III (Spain); Sepai, O.; Exley, K. [Public Health England (United Kingdom); Bloemen, L. [Environmental Health Sciences International (Netherlands); Horvat, M. [Jožef Stefan Institute (Slovenia); Knudsen, L.E. [University of Copenhagen (Denmark); Joas, A.; Joas, R. [BiPRO (Germany); Biot, P. [FPS Health, Food Chain Safety and Environment (Belgium); and others

2015-08-15

In 2011 and 2012, the COPHES/DEMOCOPHES twin projects performed the first ever harmonized human biomonitoring survey in 17 European countries. In more than 1800 mother–child pairs, individual lifestyle data were collected and cadmium, cotinine and certain phthalate metabolites were measured in urine. Total mercury was determined in hair samples. While the main goal of the COPHES/DEMOCOPHES twin projects was to develop and test harmonized protocols and procedures, the goal of the current paper is to investigate whether the observed differences in biomarker values among the countries implementing DEMOCOPHES can be interpreted using information from external databases on environmental quality and lifestyle. In general, 13 countries having implemented DEMOCOPHES provided high-quality data from external sources that were relevant for interpretation purposes. However, some data were not available for reporting or were not in line with predefined specifications. Therefore, only part of the external information could be included in the statistical analyses. Nonetheless, there was a highly significant correlation between national levels of fish consumption and mercury in hair, the strength of antismoking legislation was significantly related to urinary cotinine levels, and we were able to show indications that also urinary cadmium levels were associated with environmental quality and food quality. These results again show the potential of biomonitoring data to provide added value for (the evaluation of) evidence-informed policy making. - Highlights: • External data was collected to interpret HBM data from DEMOCOPHES. • Hg in hair could be related to fish consumption across different countries. • Urinary cotinine was related to strictness of anti-smoking legislation. • Urinary Cd was borderline significantly related to air and food quality. • Lack of comparable data among countries hampered the analysis.

MO-B-BRB-03: 3D Dosimetry in the Clinic: Validating Special Techniques

Energy Technology Data Exchange (ETDEWEB)

Juang, T. [Stanford Cancer Center (United States)

2016-06-15

irradiated volume can help understand interplay effects during TomoTherapy or VMAT. Titania Juang: Special techniques in the clinic and research Understand the potential for 3D dosimetry in validating dose accumulation in deformable systems, and Observe the benefits of high resolution measurements for precision therapy in SRS and in MicroSBRT for small animal irradiators Geoffrey S. Ibbott: 3D Dosimetry in end-to-end dosimetry QA Understand the potential for 3D dosimetry for end-to-end radiation therapy process validation in the in-house and external credentialing setting. Canadian Institutes of Health Research; L. Schreiner, Modus QA, London, ON, Canada; T. Juang, NIH R01CA100835.

MO-B-BRB-03: 3D Dosimetry in the Clinic: Validating Special Techniques

International Nuclear Information System (INIS)

Juang, T.

2016-01-01

irradiated volume can help understand interplay effects during TomoTherapy or VMAT. Titania Juang: Special techniques in the clinic and research Understand the potential for 3D dosimetry in validating dose accumulation in deformable systems, and Observe the benefits of high resolution measurements for precision therapy in SRS and in MicroSBRT for small animal irradiators Geoffrey S. Ibbott: 3D Dosimetry in end-to-end dosimetry QA Understand the potential for 3D dosimetry for end-to-end radiation therapy process validation in the in-house and external credentialing setting. Canadian Institutes of Health Research; L. Schreiner, Modus QA, London, ON, Canada; T. Juang, NIH R01CA100835

Monitoring training load to understand fatigue in athletes.

Science.gov (United States)

Halson, Shona L

2014-11-01

Many athletes, coaches, and support staff are taking an increasingly scientific approach to both designing and monitoring training programs. Appropriate load monitoring can aid in determining whether an athlete is adapting to a training program and in minimizing the risk of developing non-functional overreaching, illness, and/or injury. In order to gain an understanding of the training load and its effect on the athlete, a number of potential markers are available for use. However, very few of these markers have strong scientific evidence supporting their use, and there is yet to be a single, definitive marker described in the literature. Research has investigated a number of external load quantifying and monitoring tools, such as power output measuring devices, time-motion analysis, as well as internal load unit measures, including perception of effort, heart rate, blood lactate, and training impulse. Dissociation between external and internal load units may reveal the state of fatigue of an athlete. Other monitoring tools used by high-performance programs include heart rate recovery, neuromuscular function, biochemical/hormonal/immunological assessments, questionnaires and diaries, psychomotor speed, and sleep quality and quantity. The monitoring approach taken with athletes may depend on whether the athlete is engaging in individual or team sport activity; however, the importance of individualization of load monitoring cannot be over emphasized. Detecting meaningful changes with scientific and statistical approaches can provide confidence and certainty when implementing change. Appropriate monitoring of training load can provide important information to athletes and coaches; however, monitoring systems should be intuitive, provide efficient data analysis and interpretation, and enable efficient reporting of simple, yet scientifically valid, feedback.

Piezosurgery in External Dacryocystorhinostomy.

Science.gov (United States)

Czyz, Craig N; Fowler, Amy M; Dutton, Jonathan J; Cahill, Kenneth V; Foster, Jill A; Hill, Robert H; Everman, Kelly R; Nabavi, Cameron B

Dacryocystorhinostomy (DCR) can be performed via an external or endoscopic approach. The use of ultrasonic or piezosurgery has been well described for endoscopic DCRs but is lacking for external DCRs. This study presents a case series of external DCRs performed using piezosurgery evaluating results and complications. Prospective, consecutive case series of patients undergoing primary external DCR for lacrimal drainage insufficiency. A standard external DCR technique was used using 1 of 2 piezosurgery systems for all bone incision. All patients received silicone intubation to the lacrimal system. Surgical outcome was measured in terms of patient-reported epiphora as follows: 1) complete resolution, 2) improvement >50%, 3) improvement 50% improvement. There were 4 patients (7%) who had <50% improvement. There was 1 (2%) intraoperative complication and 2 (4%) postoperative complications recorded. Piezourgery is a viable modality for performing external DCRs. The lack of surgical complications shows a potential for decreased soft tissues damage. The surgical success rate based on patient-reported epiphora is similar to those published for mechanical external DCRs. This modality may benefit the novice surgeon in the reduction of soft and mucosal tissue damage.

The State Regulation of External Labor Migration: the Experience of the EU, France, Germany and the USA

Directory of Open Access Journals (Sweden)

Андрей Георгиевич Иванов

2009-09-01

Full Text Available The given article is devoted to the actual problem of the state regulation of external labor migration. It's based on examples of developed western countries. The author makes a conclusion about the importance of the state regulation of migration processes, warning that narrow understanding of migration policy as restriction of external migration flows is insufficient nowadays.

Understanding Influence within the Context of Nursing: Development of the Adams Influence Model Using Practice, Research, and Theory.

Science.gov (United States)

Adams, Jeffrey M; Natarajan, Sudha

2016-01-01

Acquiring influence, and knowing how to use it, is a required competency for nurse leaders, yet the concept of influence and how it works is not well described in the nursing literature. In this article, the authors examine what is known about influence and present an influence model specific to nurse leaders. The Adams Influence Model was developed through an iterative process and is based on a comprehensive review of the influence literature, expert commentary, multiple pilot studies, evaluation of nursing theories, and validation by an external data source. Rather than defining "how to" influence, the model serves as a guide for personal reflection, helping nurse leaders understand and reflect on the influence process and factors, tactics, and strategies they can use when seeking to influence others.

Congenital malformations of the external and middle ear

International Nuclear Information System (INIS)

Koesling, S.; Omenzetter, M.; Bartel-Friedrich, S.

2009-01-01

With the focus on imaging, this paper gives a summarized view of the present knowledge on fields, which are necessary to know for a profound understanding of congenital malformations of the external and middle ear. Typical and less typical combinations of malformed parts of the ear can be derived from the embryogenesis. Clinical signs and audiometric findings lead to diagnosis in congenital aural atresia. Isolated middle ear malformations can be clinically mixed up especially with otosclerosis and tympanosclerosis. Imaging is needed for exact morphological information. In malformations of the external and middle ear, CT is the imaging modality of choice. Requirements on CT-technique as well as radiological findings including classification and pre-surgical rating are described. Morphological CT-correlates of congenital malformations and their differential diagnoses are enlisted and illustrated. The impact of CT-results on therapy is explained and actual therapeutic concepts are briefly presented

Validity and Reliability in Social Science Research

Science.gov (United States)

Drost, Ellen A.

2011-01-01

In this paper, the author aims to provide novice researchers with an understanding of the general problem of validity in social science research and to acquaint them with approaches to developing strong support for the validity of their research. She provides insight into these two important concepts, namely (1) validity; and (2) reliability, and…

Non-invasive Renal Denervation: Update on External Ultrasound Approaches.

Science.gov (United States)

Schmieder, Roland E; Ott, Christian; Bramlage, Peter

2016-06-01

In the last decade, intravenous renal denervation (RDN) has emerged as an alternative to pharmacological treatment in patients with resistant hypertension, but currently involves an invasive and technically challenging procedure. The Surround Sound™ system utilises externally delivered ultrasound to achieve RDN using a completely non-invasive, automated real-time tracking system coupled with a therapeutic delivery module thereby addressing these limitations. A brief history, technical overview and summary of preclinical and clinical studies of the KonaMedical Surround Sound™ system are presented. A literature search using the terms "renal denervation", "resistant hypertension" and "external ultrasound" was performed using PubMed, and references retrieved were selected based on relevancy and year of publication (date range 1991-2015). The Surround Sound™ system appears to be a promising approach to RDN which eliminates several of the factors currently limiting the intravenous approach. So far, it has demonstrated efficacy for reducing blood pressure in resistant hypertension patients with minimal adverse effects. Several double-blind, sham-controlled clinical trials are currently underway to confirm the validity of these findings.

Patient-Reported Outcomes After Radiation Therapy in Men With Prostate Cancer: A Systematic Review of Prognostic Tool Accuracy and Validity

Energy Technology Data Exchange (ETDEWEB)

O' Callaghan, Michael E., E-mail: elspeth.raymond@health.sa.gov.au [South Australian Prostate Cancer Clinical Outcomes Collaborative (Australia); Freemasons Foundation Centre for Men' s Health, University of Adelaide (Australia); Urology Unit, Repatriation General Hospital, SA Health, Flinders Centre for Innovation in Cancer (Australia); Raymond, Elspeth [South Australian Prostate Cancer Clinical Outcomes Collaborative (Australia); Campbell, Jared M. [Joanna Briggs Institute, University of Adelaide (Australia); Vincent, Andrew D. [Freemasons Foundation Centre for Men' s Health, University of Adelaide (Australia); Beckmann, Kerri [South Australian Prostate Cancer Clinical Outcomes Collaborative (Australia); Centre for Population Health Research, University of South Australia (Australia); Roder, David [Centre for Population Health Research, University of South Australia (Australia); Evans, Sue; McNeil, John [Epidemiology and Preventative Medicine, Monash University (Australia); Millar, Jeremy [Radiation Oncology, Alfred Health (Australia); Zalcberg, John [Epidemiology and Preventative Medicine, Monash University (Australia); Borg, Martin [South Australian Prostate Cancer Clinical Outcomes Collaborative (Australia); Adelaide Radiotherapy Centre (Australia); Moretti, Kim [South Australian Prostate Cancer Clinical Outcomes Collaborative (Australia); Freemasons Foundation Centre for Men' s Health, University of Adelaide (Australia); Flinders Centre for Innovation in Cancer, Centre for Population Health Research, University of South Australia (Australia); Discipline of Surgery, University of Adelaide (Australia)

2017-06-01

Purpose: To identify, through a systematic review, all validated tools used for the prediction of patient-reported outcome measures (PROMs) in patients being treated with radiation therapy for prostate cancer, and provide a comparative summary of accuracy and generalizability. Methods and Materials: PubMed and EMBASE were searched from July 2007. Title/abstract screening, full text review, and critical appraisal were undertaken by 2 reviewers, whereas data extraction was performed by a single reviewer. Eligible articles had to provide a summary measure of accuracy and undertake internal or external validation. Tools were recommended for clinical implementation if they had been externally validated and found to have accuracy ≥70%. Results: The search strategy identified 3839 potential studies, of which 236 progressed to full text review and 22 were included. From these studies, 50 tools predicted gastrointestinal/rectal symptoms, 29 tools predicted genitourinary symptoms, 4 tools predicted erectile dysfunction, and no tools predicted quality of life. For patients treated with external beam radiation therapy, 3 tools could be recommended for the prediction of rectal toxicity, gastrointestinal toxicity, and erectile dysfunction. For patients treated with brachytherapy, 2 tools could be recommended for the prediction of urinary retention and erectile dysfunction. Conclusions: A large number of tools for the prediction of PROMs in prostate cancer patients treated with radiation therapy have been developed. Only a small minority are accurate and have been shown to be generalizable through external validation. This review provides an accessible catalogue of tools that are ready for clinical implementation as well as which should be prioritized for validation.

Externalities of fuel cycles 'ExternE' project. Natural gas fuel cycle. Estimation of physical impacts and monetary valuation for priority impact pathways

International Nuclear Information System (INIS)

Holland, M.; Watkiss, P.; Berry, J.; Johnson, C.; Lee, D.

1994-01-01

been established. Earlier work is typically of a preliminary nature and tends to be deficient with respect to both the methods employed and the quality of models and data used. In consequence of this the ExternE Project was established in 1991, with the following main objectives; 1) To identify and develop a suitable methodology with which to quantify the external costs and benefits of the major fuel cycles for electricity generation and conservation, using the best available models and data. This to be done using a common framework for assessment of different fuel cycles, in order that fair comparison can be made between them. 2) To use this methodology to assess the external costs for a number of case studies representative of each fuel cycle. 3) To make recommendations on areas in which further research is required in order that future estimates of damages can be made with greater confidence. To meet these objectives we have stressed transparency, consistency and comprehensiveness as guiding principles for the work. This applies particularly to the methods used, definition of study boundaries and listing of effects that are considered and those that are not. These principles are essential to allow valid comparison to be made between different fuel cycles, for which priority impacts may differ greatly, as illustrated by comparison of the gas, nuclear and wind fuel cycles. The present report is one of a series covering the following fuel cycles; coal, uranium, lignite, oil, gas, wind, photovoltaics, biomass and small scale hydroelectric projects. Energy security and energy conservation are also being considered within a similar framework. The methodology used is broadly similar to that identified for Life Cycle Analysis (LCA) by The Society for Environmental Toxicology and Chemistry. It is split into the following stages; 1) Definition of objectives and system boundaries; 2) Collation of an inventory of burdens associated with the process in question; 3

Understanding health constraints among rural-to-urban migrants in China.

Science.gov (United States)

Li, Yan

2013-11-01

The main purpose of this article is to examine the understanding and experience of health and health care among rural-to-urban migrants in China, and to explain the impact of the internal factors of migrants themselves and the external factors of their social environment. Understanding the perceptions and consciousness of health issues among migrants is crucial to prevention, intervention, and other health-related measures for the migrant population in China, but this has rarely been explored in studies. On the basis of a case study of a migrant community in Beijing, I explore the migrants' understandings of health and health care and analyze factors in the social environment, including exclusion from the social system and the possibility of health participation, exclusion from social relation networks, obstructed channels of health maintenance, and exclusion of crowd psychology, which impact heavily on their health understanding and health behavior. I argue that the internal and the external factors are linked together closely and interact as reciprocal causation. However, the migrants should not be seen as primarily responsible, because their poor understanding of health mainly results from the socioeconomic environment in which they live and work.

ASH External Web Portal (External Portal) -

Data.gov (United States)

Department of Transportation — The ASH External Web Portal is a web-based portal that provides single sign-on functionality, making the web portal a single location from which to be authenticated...

Response of Bose-Einstein condensates to external perturbations at finite temperature

International Nuclear Information System (INIS)

Morgan, S.A.

2004-01-01

We present a theory of the linear response of a Bose-Einstein-condensed gas to external perturbations at finite temperature. The theory developed here is the basis of a recent quantitative explanation of the measurements of condensate excitations and decay rates made at JILA [D. S. Jin et al., Phys. Rev. Lett. 78, 764 (1997)]. The formalism is based on a dynamic, number-conserving, mean-field scheme and is valid in the collisionless limit of well-defined quasiparticles. The theory is gapless, consistent with the generalized Kohn theorem for the dipole modes, and includes the time-dependent normal and anomalous averages, Beliaev and Landau processes, and all relevant finite-size effects. The important physical process where the thermal cloud is driven directly by the external perturbation is explicitly included. This is required for consistency with the dipole modes and is also needed to explain the JILA observations

Breakup of free liquid jets influenced by external mechanical vibrations

Energy Technology Data Exchange (ETDEWEB)

Lad, V N; Murthy, Z V P, E-mail: vnl@ched.svnit.ac.in, E-mail: zvpm@ched.svnit.ac.in, E-mail: zvpm2000@yahoo.com [Chemical Engineering Department, Sardar Vallabhbhai National Institute of Technology—Surat, Surat—395007, Gujarat (India)

2017-02-15

The breakup of liquid jets has been studied with various test liquids using externally imposed mechanical vibrations. Images of the jets were captured by a high speed camera up to the speed of 1000 frames per second, and analyzed to obtain the profile of the jet and breakup length. The dynamics of the jets have also been studied to understand the effects of additives—a surfactant and polymer—incorporating externally imposed mechanical vibrations. Different types of breakup modes have been explored with respect to the Weber number and Ohnesorge number. The introduction of mechanical vibrations have caused jet breakup with separated droplets at a comparatively lower Weber number. The region of jet breakup by neck formation at constant jet velocities also contracted due to mechanical vibrations. (paper)

Tracing the External Origin of the AGN Gas Fueling Reservoir

Directory of Open Access Journals (Sweden)

Sandra I. Raimundo

2018-01-01

Full Text Available Near-infrared observations of the active galaxy MCG–6-30-15 provide strong evidence that its molecular gas fueling reservoir is of external origin. MCG–6-30-15 has a counter-rotating core of stars within its central 400 pc and a counter-rotating disc of molecular gas that extends as close as ~50–100 pc from the central black hole. The gas counter-rotation establishes that the gas reservoir in the center of the galaxy originates from a past external accretion event. In this contribution we discuss the gas and stellar properties of MCG–6-30-15, its past history and how the findings on this galaxy can be used to understand AGN fueling in S0 galaxies with counter-rotating structures.

Prefrontal Cortex Networks Shift from External to Internal Modes during Learning

Science.gov (United States)

Brincat, Scott L.

2016-01-01

As we learn about items in our environment, their neural representations become increasingly enriched with our acquired knowledge. But there is little understanding of how network dynamics and neural processing related to external information changes as it becomes laden with “internal” memories. We sampled spiking and local field potential activity simultaneously from multiple sites in the lateral prefrontal cortex (PFC) and the hippocampus (HPC)—regions critical for sensory associations—of monkeys performing an object paired-associate learning task. We found that in the PFC, evoked potentials to, and neural information about, external sensory stimulation decreased while induced beta-band (∼11–27 Hz) oscillatory power and synchrony associated with “top-down” or internal processing increased. By contrast, the HPC showed little evidence of learning-related changes in either spiking activity or network dynamics. The results suggest that during associative learning, PFC networks shift their resources from external to internal processing. SIGNIFICANCE STATEMENT As we learn about items in our environment, their representations in our brain become increasingly enriched with our acquired “top-down” knowledge. We found that in the prefrontal cortex, but not the hippocampus, processing of external sensory inputs decreased while internal network dynamics related to top-down processing increased. The results suggest that during learning, prefrontal cortex networks shift their resources from external (sensory) to internal (memory) processing. PMID:27629722

External validation of the PROFUND index in polypathological patients from internal medicine and acute geriatrics departments in Aragón.

Science.gov (United States)

Díez-Manglano, Jesús; Cabrerizo García, José Luis; García-Arilla Calvo, Ernesto; Jimeno Saínz, Araceli; Calvo Beguería, Eva; Martínez-Álvarez, Rosa M; Bejarano Tello, Esperanza; Caudevilla Martínez, Aránzazu

2015-12-01

The objective of the study was to validate externally and prospectively the PROFUND index to predict survival of polypathological patients after a year. An observational, prospective and multicenter study was performed. Polypathological patients admitted to an internal medicine or geriatrics department and attended by investigators consecutively between March 1 and June 30, 2011 were included. Data concerning age, gender, comorbidity, Barthel and Lawton-Brody indexes, Pfeiffer questionnaire, socio-familial Gijon scale, delirium, number of drugs and number of admissions during the previous year were gathered for each patient. The PROFUND index was calculated. The follow-up lasted 1 year. A Cox proportional regression model was calculated, and was used to analyze the association of the variables to mortality and C-statistic. 465 polypathological patients, 333 from internal medicine and 132 from geriatrics, were included. One-year mortality is associated with age [hazard ratio (HR) 1.52 95 % CI 1.04-2.12; p = 0.01], presence of neoplasia [HR 2.68 95 % CI 1.71-4.18; p = 0.0001] and dependence for basic activities of daily living [HR 2.34 95 % CI 1.61-3.40; p = 0.0009]. In predicting mortality, the PROFUND index shows good discrimination in patients from internal medicine (C-statistics 0.725 95 % CI 0.670-0.781), but a poor one in those from geriatrics (0.546 95 % CI 0.448-0.644). The PROFUND index is a reliable tool for predicting mortality in internal medicine PP patients.

Multi-Institutional External Validation of Seminal Vesicle Invasion Nomograms: Head-to-Head Comparison of Gallina Nomogram Versus 2007 Partin Tables

International Nuclear Information System (INIS)

Zorn, Kevin C.; Capitanio, Umberto; Jeldres, Claudio; Arjane, Philippe; Perrotte, Paul; Shariat, Shahrokh F.; Lee, David I.; Shalhav, Arieh L.; Zagaja, Gregory P.; Shikanov, Sergey A.; Gofrit, Ofer N.; Thong, Alan E.; Albala, David M.; Sun, Leon; Karakiewicz, Pierre I.

2009-01-01

Purpose: The Partin tables represent one of the most widely used prostate cancer staging tools for seminal vesicle invasion (SVI) prediction. Recently, Gallina et al. reported a novel staging tool for the prediction of SVI that further incorporated the use of the percentage of positive biopsy cores. We performed an external validation of the Gallina et al. nomogram and the 2007 Partin tables in a large, multi-institutional North American cohort of men treated with robotic-assisted radical prostatectomy. Methods and Materials: Clinical and pathologic data were prospectively gathered from 2,606 patients treated with robotic-assisted radical prostatectomy at one of four North American robotic referral centers between 2002 and 2007. Discrimination was quantified with the area under the receiver operating characteristics curve. The calibration compared the predicted and observed SVI rates throughout the entire range of predictions. Results: At robotic-assisted radical prostatectomy, SVI was recorded in 4.2% of patients. The discriminant properties of the Gallina et al. nomogram resulted in 81% accuracy compared with 78% for the 2007 Partin tables. The Gallina et al. nomogram overestimated the true rate of SVI. Conversely, the Partin tables underestimated the true rate of SVI. Conclusion: The Gallina et al. nomogram offers greater accuracy (81%) than the 2007 Partin tables (78%). However, both tools are associated with calibration limitations that need to be acknowledged and considered before their implementation into clinical practice.

A Proposed Framework between Internal, External and Pedagogy Dimensions in Adoption of Interactive Multimedia e-Learning

Science.gov (United States)

Lahwal, Fathia; Al-Ajlan, Ajlan S.; Amain, Mohamad

2016-01-01

This study focuses on interactive multimedia e-learning aims to improve our understanding about the dynamics of e-learning. The objective is to critical evaluate and better understand the interrelationships in the proposed framework between internal, external and the pedagogy dimensions in adoption of interactive multimedia and e-learning. It…

Self-regulation as a predictor of patterns of change in externalizing behaviors from infancy to adolescence.

Science.gov (United States)

Perry, Nicole B; Calkins, Susan D; Dollar, Jessica M; Keane, Susan P; Shanahan, Lilly

2018-05-01

We examined associations between specific self-regulatory mechanisms and externalizing behavior patterns from ages 2 to 15 (N = 443). The relation between multiple self-regulatory indicators across multiple domains (i.e., physiological, attentional, emotional, and behavioral) at age 2 and at age 5 and group membership in four distinct externalizing trajectories was examined. By examining each of these self-regulatory processes in combination with one another, and therefore accounting for their shared variance, we aimed to better understand which specific self-regulatory skills were associated most strongly with externalizing behavioral patterns. Findings suggest that behavioral inhibitory control and emotion regulation are particularly important in distinguishing between children who show normative declines in externalizing behaviors across early childhood and those who demonstrate high levels through adolescence.

Internal Motion Estimation by Internal-external Motion Modeling for Lung Cancer Radiotherapy.

Science.gov (United States)

Chen, Haibin; Zhong, Zichun; Yang, Yiwei; Chen, Jiawei; Zhou, Linghong; Zhen, Xin; Gu, Xuejun

2018-02-27

The aim of this study is to develop an internal-external correlation model for internal motion estimation for lung cancer radiotherapy. Deformation vector fields that characterize the internal-external motion are obtained by respectively registering the internal organ meshes and external surface meshes from the 4DCT images via a recently developed local topology preserved non-rigid point matching algorithm. A composite matrix is constructed by combing the estimated internal phasic DVFs with external phasic and directional DVFs. Principle component analysis is then applied to the composite matrix to extract principal motion characteristics, and generate model parameters to correlate the internal-external motion. The proposed model is evaluated on a 4D NURBS-based cardiac-torso (NCAT) synthetic phantom and 4DCT images from five lung cancer patients. For tumor tracking, the center of mass errors of the tracked tumor are 0.8(±0.5)mm/0.8(±0.4)mm for synthetic data, and 1.3(±1.0)mm/1.2(±1.2)mm for patient data in the intra-fraction/inter-fraction tracking, respectively. For lung tracking, the percent errors of the tracked contours are 0.06(±0.02)/0.07(±0.03) for synthetic data, and 0.06(±0.02)/0.06(±0.02) for patient data in the intra-fraction/inter-fraction tracking, respectively. The extensive validations have demonstrated the effectiveness and reliability of the proposed model in motion tracking for both the tumor and the lung in lung cancer radiotherapy.

Predicting Failure in Early Acute Prosthetic Joint Infection Treated With Debridement, Antibiotics, and Implant Retention: External Validation of the KLIC Score.

Science.gov (United States)

Löwik, Claudia A M; Jutte, Paul C; Tornero, Eduard; Ploegmakers, Joris J W; Knobben, Bas A S; de Vries, Astrid J; Zijlstra, Wierd P; Dijkstra, Baukje; Soriano, Alex; Wouthuyzen-Bakker, Marjan

2018-03-27

Debridement, antibiotics, and implant retention (DAIR) is a widely used treatment modality for early acute prosthetic joint infection (PJI). A preoperative risk score was previously designed for predicting DAIR failure, consisting of chronic renal failure (K), liver cirrhosis (L), index surgery (I), cemented prosthesis (C), and C-reactive protein >115 mg/L (KLIC). The aim of this study was to validate the KLIC score in an external cohort. We retrospectively evaluated patients with early acute PJI treated with DAIR between 2006 and 2016 in 3 Dutch hospitals. Early acute PJI was defined as infection-related death within 60 days after debridement. A total of 386 patients were included. Failure occurred in 148 patients (38.3%). Patients with KLIC scores of ≤2, 2.5-3.5, 4-5, 5.5-6.5, and ≥7 had failure rates of 27.9%, 37.1%, 49.3%, 54.5%, and 85.7%, respectively (P < .001). The receiver-operating characteristic curve showed an area under the curve of 0.64 (95% confidence interval 0.59-0.69). A KLIC score higher than 6 points showed a specificity of 97.9%. The KLIC score is a relatively good preoperative risk score for DAIR failure in patients with early acute PJI and appears to be most useful in clinical practice for patients with low or high KLIC scores. Copyright © 2018 Elsevier Inc. All rights reserved.

How does context affect intimate relationships? linking external stress and cognitive processes within marriage.

Science.gov (United States)

Neff, Lisa A; Karney, Benjamin R

2004-02-01

Stressors external to the marriage frequently affect the way spouses evaluate their marital quality. To date, however, understanding of the interplay between external stress and internal relationship processes has been limited in two ways. First, research has generally examined only the short-term consequences of stress. Second, the mechanisms through which external stressors influence relationship outcomes are unclear. This study addressed both limitations by examining relationship cognitions that may mediate the effects of external stress throughout 4 years of marriage. Analyses confirmed that stressful experiences were associated with the trajectory of marital quality overtime. Furthermore, both the content and the organization of spouses' specific relationship cognitions mediated this effect. That is, stress negatively influenced the nature of spouses' marital perceptions as well as the way spouses interpreted and processed those perceptions. These findings draw attention to ways that the context of relationships shapes and constrains relationship processes.

Understanding and Measuring Evaluation Capacity: A Model and Instrument Validation Study

Science.gov (United States)

Taylor-Ritzler, Tina; Suarez-Balcazar, Yolanda; Garcia-Iriarte, Edurne; Henry, David B.; Balcazar, Fabricio E.

2013-01-01

This study describes the development and validation of the Evaluation Capacity Assessment Instrument (ECAI), a measure designed to assess evaluation capacity among staff of nonprofit organizations that is based on a synthesis model of evaluation capacity. One hundred and sixty-nine staff of nonprofit organizations completed the ECAI. The 68-item…

External validation of the simple clinical score and the HOTEL score, two scores for predicting short-term mortality after admission to an acute medical unit.

Science.gov (United States)

Stræde, Mia; Brabrand, Mikkel

2014-01-01

Clinical scores can be of aid to predict early mortality after admission to a medical admission unit. A developed scoring system needs to be externally validated to minimise the risk of the discriminatory power and calibration to be falsely elevated. We performed the present study with the objective of validating the Simple Clinical Score (SCS) and the HOTEL score, two existing risk stratification systems that predict mortality for medical patients based solely on clinical information, but not only vital signs. Pre-planned prospective observational cohort study. Danish 460-bed regional teaching hospital. We included 3046 consecutive patients from 2 October 2008 until 19 February 2009. 26 (0.9%) died within one calendar day and 196 (6.4%) died within 30 days. We calculated SCS for 1080 patients. We found an AUROC of 0.960 (95% confidence interval [CI], 0.932 to 0.988) for 24-hours mortality and 0.826 (95% CI, 0.774-0.879) for 30-day mortality, and goodness-of-fit test, χ(2) = 2.68 (10 degrees of freedom), P = 0.998 and χ(2) = 4.00, P = 0.947, respectively. We included 1470 patients when calculating the HOTEL score. Discriminatory power (AUROC) was 0.931 (95% CI, 0.901-0.962) for 24-hours mortality and goodness-of-fit test, χ(2) = 5.56 (10 degrees of freedom), P = 0.234. We find that both the SCS and HOTEL scores showed an excellent to outstanding ability in identifying patients at high risk of dying with good or acceptable precision.

Understanding Extraordinary Architectural Experiences through Content Analysis of Written Narratives

Directory of Open Access Journals (Sweden)

Brandon Richard Ro

2015-12-01

Full Text Available This study a identifies how people describe, characterize, and communicate in written form Extraordinary Architectural Experiences (EAE, and b expands the traditional qualitative approach to architectural phenomenology by demonstrating a quantitative method to analyze written narratives. Specifically, this study reports on the content analysis of 718 personal accounts of EAEs. Using a deductive, ‘theory-driven’ approach, these narratives were read, coded, and statistically analyzed to identify storyline structure, convincing power, and the relationship between subjective and objective experiential qualities used in the story-telling process. Statistical intercoder agreement tests were conducted to verify the reliability of the interpretations to approach the hard problem of “extraordinary aesthetics” in architecture empirically. The results of this study confirm the aesthetic nature of EAE narratives (and of told experiences by showing their higher dependence on external objective content (e.g., a building’s features and location rather than its internal subjective counterpart (e.g., emotions and sensations, which makes them more outwardly focused. The strong interrelationships and intercoder agreement between the thematic realms provide a unique aesthetic construct revealing EAE narratives as memorable, embodied, emotional events mapped by the externally focused content of place, social setting, time, and building features. A majority of EAE narratives were found to possess plot-structure along with significant relationships to objective-subjective content that further grounded their storylines. This study concludes that content analysis provides not only a valid method to understand written narratives about extraordinary architectural experiences quantitatively, but also a view as to how to map the unique nature of aesthetic phenomenology empirically.

Validation and Refinement of Prediction Models to Estimate Exercise Capacity in Cancer Survivors Using the Steep Ramp Test

NARCIS (Netherlands)

Stuiver, Martijn M.; Kampshoff, Caroline S.; Persoon, Saskia; Groen, Wim; van Mechelen, Willem; Chinapaw, Mai J. M.; Brug, Johannes; Nollet, Frans; Kersten, Marie-José; Schep, Goof; Buffart, Laurien M.

2017-01-01

Objective: To further test the validity and clinical usefulness of the steep ramp test (SRT) in estimating exercise tolerance in cancer survivors by external validation and extension of previously published prediction models for peak oxygen consumption (Vo2(peak)) and peak power output (W-peak).&

External validation of a publicly available computer assisted diagnostic tool for mammographic mass lesions with two high prevalence research datasets.

Science.gov (United States)

Benndorf, Matthias; Burnside, Elizabeth S; Herda, Christoph; Langer, Mathias; Kotter, Elmar

2015-08-01

Lesions detected at mammography are described with a highly standardized terminology: the breast imaging-reporting and data system (BI-RADS) lexicon. Up to now, no validated semantic computer assisted classification algorithm exists to interactively link combinations of morphological descriptors from the lexicon to a probabilistic risk estimate of malignancy. The authors therefore aim at the external validation of the mammographic mass diagnosis (MMassDx) algorithm. A classification algorithm like MMassDx must perform well in a variety of clinical circumstances and in datasets that were not used to generate the algorithm in order to ultimately become accepted in clinical routine. The MMassDx algorithm uses a naïve Bayes network and calculates post-test probabilities of malignancy based on two distinct sets of variables, (a) BI-RADS descriptors and age ("descriptor model") and (b) BI-RADS descriptors, age, and BI-RADS assessment categories ("inclusive model"). The authors evaluate both the MMassDx (descriptor) and MMassDx (inclusive) models using two large publicly available datasets of mammographic mass lesions: the digital database for screening mammography (DDSM) dataset, which contains two subsets from the same examinations-a medio-lateral oblique (MLO) view and cranio-caudal (CC) view dataset-and the mammographic mass (MM) dataset. The DDSM contains 1220 mass lesions and the MM dataset contains 961 mass lesions. The authors evaluate discriminative performance using area under the receiver-operating-characteristic curve (AUC) and compare this to the BI-RADS assessment categories alone (i.e., the clinical performance) using the DeLong method. The authors also evaluate whether assigned probabilistic risk estimates reflect the lesions' true risk of malignancy using calibration curves. The authors demonstrate that the MMassDx algorithms show good discriminatory performance. AUC for the MMassDx (descriptor) model in the DDSM data is 0.876/0.895 (MLO/CC view) and AUC

External Validation of Contact Surface Area as a Predictor of Postoperative Renal Function in Patients Undergoing Partial Nephrectomy.

Science.gov (United States)

Haifler, Miki; Ristau, Benjamin T; Higgins, Andrew M; Smaldone, Marc C; Kutikov, Alexander; Zisman, Amnon; Uzzo, Robert G

2017-09-20

We sought to externally validate a mathematical formula for tumor contact surface area as a predictor of postoperative renal function in patients undergoing partial nephrectomy for renal cell carcinoma. We queried a prospectively maintained kidney cancer database for patients who underwent partial nephrectomy between 2014 and 2016. Contact surface area was calculated using data obtained from preoperative cross-sectional imaging. The correlation between contact surface area and perioperative variables was examined. The correlation between postoperative renal functional outcomes, contact surface area and the R.E.N.A.L. (radius, exophytic/endophytic properties, nearness of tumor to collecting system or sinus, anterior/posterior, location relative to polar lines and tumor touches main renal artery or vein) nephrometry score was also assessed. A total of 257 patients who underwent partial nephrectomy had sufficient data to enter the study. Median contact surface area was 14.5 cm 2 (IQR 6.2-36) and the median nephrometry score was 9 (IQR 7-10). Spearman correlation analysis showed that contact surface area correlated with estimated blood loss (r s = 0.42, p contact surface area and nephrometry score were independent predictors of the absolute change in the estimated glomerular filtration rate (each p contact surface area was a better predictor of a greater than 20% postoperative decline in the estimated glomerular filtration rate compared with the nephrometry score (AUC 0.94 vs 0.80). Contact surface area correlated with the change in postoperative renal function after partial nephrectomy. It can be used in conjunction with the nephrometry score to counsel patients about the risk of renal functional decline after partial nephrectomy. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Collaborative entrepreneurship: On the Influence of Internal and External Collaboration on Corporate Entrepreneurial Innovation

DEFF Research Database (Denmark)

Lassen, Astrid Heidemann; Timenes Laugen, Bjørge; Middel, Rick

2008-01-01

The present paper empirically tests the effect which internal/external collaboration has on innovation height and identifies characteristics of collaboration patterns leading to entrepreneurial innovation in particular. Doing so adds to the understanding of how corporate entrepreneurship best...... unfolds as interfirm activity, which here is termed collaborative entrepreneurship, and provides details on the particular patterns of Open Innovation. The empirical analysis is based on a data set with responses from 512 Danish engineers. The analysis finds that external collaboration has significantly...... different effects on innovation height depending on the type of partners involved, and furthermore suggests that the development of entrepreneurial innovation is not only dependent on high external involvement, but also on involvement and collaboration among internal functional departments and people....

External validity of the Indonesian Wechsler Adult Intelligence Scale - Fourth edition (WAIS-IV-ID)

NARCIS (Netherlands)

Suwartono, C.; Hidajat, L.L.; Halim, M.S.; Hendriks, M.P.H.; Kessels, R.P.C.

2016-01-01

The Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV-ID) has been adapted and proved to be valid for its internal structure for Indonesian population. The same structure found as in the American WAIS-IV (WAIS-IV-US; Suwartono, Hendriks, Hidajat, Halim, & Kessels, 2015). Despite its strong

The predictive and external validity of the STarT Back Tool in Danish primary care.

Science.gov (United States)

Morsø, Lars; Kent, Peter; Albert, Hanne B; Hill, Jonathan C; Kongsted, Alice; Manniche, Claus

2013-08-01

The STarT Back Tool (SBT) was recently translated into Danish and its concurrent validity described. This study tested the predictive validity of the Danish SBT. Danish primary care patients (n = 344) were compared to a UK cohort. SBT subgroup validity for predicting high activity limitation at 3 months' follow-up was assessed using descriptive proportions, relative risks, AUC and odds ratios. The SBT had a statistically similar predictive ability in Danish primary care as in UK primary care. Unadjusted relative risks for poor clinical outcome on activity limitation in the Danish cohort were 2.4 (1.7-3.4) for the medium-risk subgroup and 2.8 (1.8-3.8) for the high-risk subgroup versus 3.1 (2.5-3.9) and 4.5 (3.6-5.6) for the UK cohort. Adjusting for confounders appeared to explain the lower predictive ability of the Danish high-risk group. The Danish SBT distinguished between low- and medium-risk subgroups with a similar predictive ability of the UK SBT. That distinction is useful information for informing patients about their expected prognosis and may help guiding clinicians' choice of treatment. However, cross-cultural differences in the SBT psychosocial subscale may reduce the predictive ability of the high-risk subgroup in Danish primary care.

A Critical Assessment of the Quality and Validity of Composite Indicators of Innovation

Energy Technology Data Exchange (ETDEWEB)

Vértesy, D.

2016-07-01

While it is generally accepted that monitoring innovation system performance requires a set of indicators, there is a constant debate on whether and how composite indices can be used to summarize them. This paper enters this discussion by assessing the validity and quality of the most commonly used composite indicators of innovation. In our framework, the validity of an index relates to the link between component indicators or aggregates and to the aspect(s) of national systems of innovation they seek to measure, while the quality of an indicator relates to its statistical properties. To better understand validity, we discuss how the evolution of the national system of innovation concept and its use in policy has shifted demand from an advocacy to more analytical functions of composite indicators of innovation.We next examine selected composite indicators of innovation (the WIPO-INSEAD’s Global Innovation Indicator, the Summary Innovation Index and Innovation Output Indicator of the European Commission and the Fraunhofer Innovation Index) in different contexts of external and internal validity and conduct global sensitivity analyses on them. Our policy-relevant findings highlight the need for analytically stronger composites of a more limited set of indicators.We also found significant quality differences across the indices, as some included components which explain little or none of the variance in composite scores, and were more sensitive to modeling choices. The indices studied differed in how validly they represented various innovation system functions and types of innovation, and showed information relevant for a broader or a more limited set of stakeholders. We argue that further development of innovation indicators should put more emphasis on identifying tradeoffs within innovation policy, and unintended consequences of innovative activities. (Author)

Soil carbon mineralization following biochar addition associated with external nitrogen

Directory of Open Access Journals (Sweden)

Rudong Zhao

2015-12-01

Full Text Available Biochar has been attracting increasing attention for its potentials of C sequestration and soil amendment. This study aimed to understand the effects of combining biochar with additional external N on soil C mineralization. A typical red soil (Plinthudults was treated with two biochars made from two types of plantation-tree trunks (soil-biochar treatments, and was also treated with external N (soil-biochar-N treatments. All treatments were incubated for 42 d. The CO2-C released from the treatments was detected periodically. After the incubation, soil properties such as pH, microbial biomass C (MBC, and microbial biomass N (MBN were measured. The addition of biochar with external N increased the soil pH (4.31-4.33 compared to the soil treated with external N only (4.21. This was not observed in the comparison of soil-biochar treatments (4.75-4.80 to soil only (4.74. Biochar additions (whether or not they were associated with external N increased soil MBC and MBN, but decreased CO2-C value per unit total C (added biochar C + soil C according to the model fitting. The total CO2-C released in soil-biochar treatments were enhanced compared to soil only (i.e., 3.15 vs. 2.57 mg and 3.23 vs. 2.45 mg, which was attributed to the labile C fractions in the biochars and through soil microorganism enhancement. However, there were few changes in soil C mineralization in soil-biochar-N treatments. Additionally, the potentially available C per unit total C in soil-biochar-N treatments was lower than that observed in the soil-biochar treatments. Therefore, we believe in the short term, that C mineralization in the soil can be enhanced by biochar addition, but not by adding external N concomitantly.

Prediction of the neutrons subcritical multiplication using the diffusion hybrid equation with external neutron sources

Energy Technology Data Exchange (ETDEWEB)

Costa da Silva, Adilson; Carvalho da Silva, Fernando [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, 21941-914, Rio de Janeiro (Brazil); Senra Martinez, Aquilino, E-mail: aquilino@lmp.ufrj.br [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, 21941-914, Rio de Janeiro (Brazil)

2011-07-15

Highlights: > We proposed a new neutron diffusion hybrid equation with external neutron source. > A coarse mesh finite difference method for the adjoint flux and reactivity calculation was developed. > 1/M curve to predict the criticality condition is used. - Abstract: We used the neutron diffusion hybrid equation, in cartesian geometry with external neutron sources to predict the subcritical multiplication of neutrons in a pressurized water reactor, using a 1/M curve to predict the criticality condition. A Coarse Mesh Finite Difference Method was developed for the adjoint flux calculation and to obtain the reactivity values of the reactor. The results obtained were compared with benchmark values in order to validate the methodology presented in this paper.

Prediction of the neutrons subcritical multiplication using the diffusion hybrid equation with external neutron sources

International Nuclear Information System (INIS)

Costa da Silva, Adilson; Carvalho da Silva, Fernando; Senra Martinez, Aquilino

2011-01-01

Highlights: → We proposed a new neutron diffusion hybrid equation with external neutron source. → A coarse mesh finite difference method for the adjoint flux and reactivity calculation was developed. → 1/M curve to predict the criticality condition is used. - Abstract: We used the neutron diffusion hybrid equation, in cartesian geometry with external neutron sources to predict the subcritical multiplication of neutrons in a pressurized water reactor, using a 1/M curve to predict the criticality condition. A Coarse Mesh Finite Difference Method was developed for the adjoint flux calculation and to obtain the reactivity values of the reactor. The results obtained were compared with benchmark values in order to validate the methodology presented in this paper.

ExternE: Externalities of energy Vol. 3. Coal and lignite

International Nuclear Information System (INIS)

Berry, J.; Holland, M.; Lee, D.

1995-01-01

Awareness of the environmental damage resulting from human activity, particularly concerning energy use, has grown greatly in recent years. Effects such as global warming, ozone depletion and acid rain are now the subjects of much research and public debate. It is now known that these and other effects damage a wide range of receptors, including human health, forests, crops, freshwater ecosystems and buildings. Such damages are typically not accounted for by the producers and consumers of the good in question (in this case energy). They are thus referred to as 'external costs' or 'externalities', to distinguish them from the private costs which account for the construction of plant, cost of fuel, wages, etc. In recent years there has been a growing interest in the assessment of the environmental and health impacts of energy, and the related external costs. This concern is driven by a number of different factors: the need to integrate environmental concerns in decision making over the choice between different fuels and energy technologies; the need to evaluate the costs and benefits of stricter environmental standards; increased attention to the use of economic instruments for environmental policy; the need to develop overall indicators of environmental performance of different technologies; major changes in the energy sector, including privatisation, liberalisation of markets, reduction of subsidies, etc. An agreed methodology for calculation and integration of external costs has not been established. Earlier work is typically of a preliminary nature and tends to be deficient with respect to both the methods employed and the quality of models and data used. In consequence of this a collaborative project, the EC/US Fuel Cycles Study, was established between Directorate General XII (Science, Research and Technology) of the European Commission and the United States Department of Energy. This ran for the period 1991 to 1993, and good agreement on a variety of

Further Understanding of the Food Safety Problem

Institute of Scientific and Technical Information of China (English)

Xingxing; MEI; Zhongchao; FENG; Pinghua; HE; Yawen; GAO; Yuqin; DAI

2015-01-01

Frequent occurrence of food quality and safety proves that it is not effective to solve the Problem only from mechanism and supervision mechanism. Instead,it may expand solution ideas from external environment inducing changes of social institutions. Edible agricultural products are raw materials of foods,so their quality and safety are decisive for food quality and safety. Combining with concept of quality and safety of edible agricultural products,from social economy,science,technology and culture,environment cognition,this paper made a further understanding of food quality and safety. It found that the quality and safety of domestic edible agricultural products are not completely resulted from human factor,and not completely quality and safety problem in practical sense. Design of problem solutions should consider such external factors as economic level and consumption concept,dual character of science and technology,cultural quality of the masses,and moral trait of the masses,and enhance matching of building of regulation tools with external environment.

Derivation and Cross-Validation of Cutoff Scores for Patients With Schizophrenia Spectrum Disorders on WAIS-IV Digit Span-Based Performance Validity Measures.

Science.gov (United States)

Glassmire, David M; Toofanian Ross, Parnian; Kinney, Dominique I; Nitch, Stephen R

2016-06-01

Two studies were conducted to identify and cross-validate cutoff scores on the Wechsler Adult Intelligence Scale-Fourth Edition Digit Span-based embedded performance validity (PV) measures for individuals with schizophrenia spectrum disorders. In Study 1, normative scores were identified on Digit Span-embedded PV measures among a sample of patients (n = 84) with schizophrenia spectrum diagnoses who had no known incentive to perform poorly and who put forth valid effort on external PV tests. Previously identified cutoff scores resulted in unacceptable false positive rates and lower cutoff scores were adopted to maintain specificity levels ≥90%. In Study 2, the revised cutoff scores were cross-validated within a sample of schizophrenia spectrum patients (n = 96) committed as incompetent to stand trial. Performance on Digit Span PV measures was significantly related to Full Scale IQ in both studies, indicating the need to consider the intellectual functioning of examinees with psychotic spectrum disorders when interpreting scores on Digit Span PV measures. © The Author(s) 2015.

When attention wanders: Pupillometric signatures of fluctuations in external attention.

Science.gov (United States)

Konishi, Mahiko; Brown, Kevin; Battaglini, Luca; Smallwood, Jonathan

2017-11-01

Attention is not always directed to events in the external environment. On occasion our thoughts wander to people and places distant from the here and now. Sometimes, this lack of external attention can compromise ongoing task performance. In the current study we set out to understand the extent to which states of internal and external attention can be determined using pupillometry as an index of ongoing cognition. In two experiments we found that periods of slow responding were associated with elevations in the baseline pupil signal over three and a half seconds prior to a behavioural response. In the second experiment we found that unlike behavioural lapses, states of off-task thought, particularly those associated with a focus on the past and with an intrusive quality, were associated with reductions in the size of the pupil over the same window prior to the probe. These data show that both states of large and small baseline pupil size are linked to states when attention is not effectively focused on the external environment, although these states have different qualities. More generally, these findings illustrate that subjective and objective markers of task performance may not be equivalent and underscore the importance of developing objective indicators that can allow these different states to be understood. Copyright © 2017 Elsevier B.V. All rights reserved.

Utilization of automated external defibrillators installed in commonly used areas of Japanese hospitals

OpenAIRE

OHTA, SHOICHI; NAKAO, HIROYUKI; KUSHIMOTO, SHIGEKI; HIRAIDE, ATSUSHI; SAKAMOTO, TETSUYA; NAGAO, KEN; HORI, SHINGO

2013-01-01

Objective. Since July 2004, it has become legal in Japan for laypersons to use automated external defibrillators (AEDs). We investigated the effect of AED installation in commonly used areas of Japanese Association for Acute Medicine accredited training (JAAM) hospitals. Methods. In 2008, we sent questionnaires to 419 JAAM hospitals enquiring about the systems, operations, outcome and characteristics of AED usage. Results. Valid responses were received from 271 hospitals (64.7%). A total of 2...

Validity of a self-administered food frequency questionnaire (FFQ and its generalizability to the estimation of dietary folate intake in Japan

Directory of Open Access Journals (Sweden)

Iso Hiroyasu

2005-10-01

Full Text Available Abstract Background In an epidemiological study, it is essential to test the validity of the food frequency questionnaire (FFQ for its ability to estimate dietary intake. The objectives of our study were to 1 validate a FFQ for estimating folate intake, and to identify the foods that contribute to inter-individual variation of folate intake in the Japanese population. Methods Validity of the FFQ was evaluated using 28-day weighed dietary records (DRs as gold standard in the two groups independently. In the group for which the FFQ was developed, validity was evaluated by Spearman's correlation coefficients (CCs, and linear regression analysis was used to identify foods with large inter-individual variation. The cumulative mean intake of these foods was compared with total intake estimated by the DR. The external validity of the FFQ and intake from foods on the same list were evaluated in the other group to verify generalizability. Subjects were a subsample from the Japan Public Health Center-based prospective Study who volunteered to participate in the FFQ validation study. Results CCs for the internal validity of the FFQ were 0.49 for men and 0.29 and women, while CCs for external validity were 0.33 for men and 0.42 for women. CCs for cumulative folate intake from 33 foods selected by regression analysis were also applicable to an external population. Conclusion Our FFQ was valid for and generalizable to the estimation of folate intake. Foods identified as predictors of inter-individual variation in folate intake were also generalizable in Japanese populations. The FFQ with 138 foods was valid for the estimation of folate intake, while that with 33 foods might be useful for estimating inter-individual variation and ranking of individual folate intake.

Validity of a self-administered food frequency questionnaire (FFQ) and its generalizability to the estimation of dietary folate intake in Japan

Science.gov (United States)

Ishihara, Junko; Yamamoto, Seiichiro; Iso, Hiroyasu; Inoue, Manami; Tsugane, Shoichiro

2005-01-01

Background In an epidemiological study, it is essential to test the validity of the food frequency questionnaire (FFQ) for its ability to estimate dietary intake. The objectives of our study were to 1) validate a FFQ for estimating folate intake, and to identify the foods that contribute to inter-individual variation of folate intake in the Japanese population. Methods Validity of the FFQ was evaluated using 28-day weighed dietary records (DRs) as gold standard in the two groups independently. In the group for which the FFQ was developed, validity was evaluated by Spearman's correlation coefficients (CCs), and linear regression analysis was used to identify foods with large inter-individual variation. The cumulative mean intake of these foods was compared with total intake estimated by the DR. The external validity of the FFQ and intake from foods on the same list were evaluated in the other group to verify generalizability. Subjects were a subsample from the Japan Public Health Center-based prospective Study who volunteered to participate in the FFQ validation study. Results CCs for the internal validity of the FFQ were 0.49 for men and 0.29 and women, while CCs for external validity were 0.33 for men and 0.42 for women. CCs for cumulative folate intake from 33 foods selected by regression analysis were also applicable to an external population. Conclusion Our FFQ was valid for and generalizable to the estimation of folate intake. Foods identified as predictors of inter-individual variation in folate intake were also generalizable in Japanese populations. The FFQ with 138 foods was valid for the estimation of folate intake, while that with 33 foods might be useful for estimating inter-individual variation and ranking of individual folate intake. PMID:16202175

The SATISPSY-22: development and validation of a French hospitalized patients' satisfaction questionnaire in psychiatry.

Science.gov (United States)

Zendjidjian, X Y; Auquier, P; Lançon, C; Loundou, A; Parola, N; Faugère, M; Boyer, L

2015-01-01

The aim of our study was to develop a specific French self-administered instrument for measuring hospitalized patients' satisfaction in psychiatry based on exclusive patient point of view: the SATISPSY-22. The development of the SATISPSY was undertaken in three steps: item generation, item reduction, and validation. The content of the SATISPSY was derived from 80 interviews with patients hospitalized in psychiatry. Using item response and classical test theories, item reduction was performed in 2 hospitals on 270 responders. The validation was based on construct validity, reliability, and some aspects of external validity. The SATISPSY contains 22 items describing 6 dimensions (staff, quality of care, personal experience, information, activity, and food). The six-factor structure accounted for 78.0% of the total variance. Each item achieved the 0.40 standard for item-internal consistency, and the Cronbach's alpha coefficients were>0.70. Scores of dimensions were strongly positively correlated with Visual Analogue Scale scores. Significant associations with socioeconomic and clinical indicators showed good discriminant and external validity. INFIT statistics were ranged from 0.71 to 1.25. The SATISPSY-22 presents satisfactory psychometric properties, enabling patient feedback to be incorporated in a continuous quality health care improvement strategy. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Atlantic Meridional Overturning Circulation response to idealized external forcing

Energy Technology Data Exchange (ETDEWEB)

Park, W.; Latif, M. [Leibniz-Institut fuer Meereswissenschaften an der Universitaet Kiel, Kiel (Germany)

2012-10-15

The response of the Atlantic Meridional Overturning Circulation (AMOC) to idealized external (solar) forcing is studied in terms of the internal (unforced) AMOC modes with the Kiel Climate Model (KCM), a coupled atmosphere-ocean-sea ice general circulation model. The statistical investigation of KCM's internal AMOC variability obtained from a multi-millennial control run yields three distinct modes: a multi-decadal mode with a period of about 60 years, a quasi-centennial mode with a period of about 100 years and a multi-centennial mode with a period of about 300-400 years. Most variance is explained by the multi-centennial mode, and the least by the quasi-centennial mode. The solar constant varies sinusoidally with two different periods (100 and 60 years) in forced runs with KCM. The AMOC response to the external forcing is rather complex and nonlinear. It involves strong changes in the frequency structure of the variability. While the control run depicts multi-timescale behavior, the AMOC variability in the experiment with 100 year forcing period is channeled into a relatively narrow band centered near the forcing period. It is the quasi-centennial AMOC mode with a period of just under 100 years which is excited, although it is heavily damped in the control run. Thus, the quasi-centennial mode retains its period which does not correspond exactly to the forcing period. Surprisingly, the quasi-centennial mode is also most strongly excited when the forcing period is set to 60 years, the period of the multi-decadal mode which is rather prominent in the control run. It is largely the spatial structure of the forcing rather than its period that determines which of the three internal AMOC modes is excited. The results suggest that we need to understand the full modal structure of the internal AMOC variability in order to understand the circulation's response to external forcing. This could be a challenge for climate models: we cannot necessarily expect that the

Electron-correlation based externally predictive QSARs for mutagenicity of nitrated-PAHs in Salmonella typhimurium TA100.

Science.gov (United States)

Reenu; Vikas

2014-03-01

In quantitative modeling, there are two major aspects that decide reliability and real external predictivity of a structure-activity relationship (SAR) based on quantum chemical descriptors. First, the information encoded in employed molecular descriptors, computed through a quantum-mechanical method, should be precisely estimated. The accuracy of the quantum-mechanical method, however, is dependent upon the amount of electron-correlation it incorporates. Second, the real external predictivity of a developed quantitative SAR (QSAR) should be validated employing an external prediction set. In this work, to analyze the role of electron-correlation, QSAR models are developed for a set of 51 ubiquitous pollutants, namely, nitrated monocyclic and polycyclic aromatic hydrocarbons (nitrated-AHs and PAHs) having mutagenic activity in TA100 strain of Salmonella typhimurium. The quality of the models, through state-of-the-art external validation procedures employing an external prediction set, is compared to the best models known in the literature for mutagenicity. The molecular descriptors whose electron-correlation contribution is analyzed include total energy, energy of HOMO and LUMO, and commonly employed electron-density based descriptors such as chemical hardness, chemical softness, absolute electronegativity and electrophilicity index. The electron-correlation based QSARs are also compared with those developed using quantum-mechanical descriptors computed with advanced semi-empirical (SE) methods such as PM6, PM7, RM1, and ab initio methods, namely, the Hartree-Fock (HF) and the density functional theory (DFT). The models, developed using electron-correlation contribution of the quantum-mechanical descriptors, are found to be not only reliable but also satisfactorily predictive when compared to the existing robust models. The robustness of the models based on descriptors computed through advanced SE methods, is also observed to be comparable to those developed with

The Role of Maternal Depression on Treatment Outcome for Children with Externalizing Behavior Problems

NARCIS (Netherlands)

Loon, L.M.A. van; Granic, I.; Engels, R.C.M.E.

2011-01-01

Studies have shown that, on average, Parent Management Training combined with cognitive-behavioral therapy decreases children's externalizing behavior, but some children do not improve through treatment. The current study aimed to examine the role of maternal depression in understanding this

Does Competence Mediate the Associations between Puberty and Internalizing or Externalizing Problems in Adolescent Girls

Science.gov (United States)

Negriff, Sonya; Hillman, Jennifer, B.; Dorn, Lorah D.

2011-01-01

Purpose To examine separate mediational models linking a) menarcheal status or b) pubertal timing to internalizing and externalizing problems through competence. Method Cross-sectional analyses of 262 adolescent girls (11–17 years; M=14.93, SD=2.17) enrolled in a longitudinal study examining the association of psychological functioning and smoking with reproductive and bone health. Measures of menarcheal status (pre/post), pubertal timing (early, on-time, or late), internalizing and externalizing behavior, and perceived competence (parent and adolescent report) were obtained. Structural Equation Modeling was used for analyses. Results Perceived competence was found to fully mediate the association between menarcheal status and parent report of internalizing and externalizing problems. For adolescent report, there was a full mediation effect for internalizing problems but a partial mediation effect for externalizing problems. Being menarcheal was related to lower competence which was related to higher internalizing and externalizing problems. Models including pubertal timing were not significant. Conclusions Perceived competence is important in understanding the associations between menarcheal status and internalizing and externalizing problems. Interventions targeting competence, particularly in post-menarcheal girls, may reduce or prevent problem behaviors. PMID:21939864

Development and validation of the goal content for exercise questionnaire.

Science.gov (United States)

Sebire, Simon J; Standage, Martyn; Vansteenkiste, Maarten

2008-08-01

Self-determination theory (SDT; Deci & Ryan, 2000) proposes that intrinsic, relative to extrinsic, goal content is a critical predictor of the quality of an individual's behavior and psychological well-being. Through three studies, we developed and psychometrically tested a measure of intrinsic and extrinsic goal content in the exercise context: the Goal Content for Exercise Questionnaire (GCEQ). In adults, exploratory (N = 354; Study 1) and confirmatory factor analyses (N = 312; Study 2) supported a 20-item solution consisting of 5 lower order factors (i.e., social affiliation, health management, skill development, image and social recognition) that could be subsumed within a 2-factor higher order structure (i.e., intrinsic and extrinsic). Evidence for external validity, temporal stability, gender invariance, and internal consistency of the GCEQ was found. An independent sample (N = 475; Study 3) provided further support for the lower order structure of the GCEQ and some support for the higher order structure. The GCEQ was supported as a measure of exercise-based goal content, which may help understand how intrinsic and extrinsic goals can motivate exercise behavior.

Effect of External Electric Field on Substrate Transport of a Secondary Active Transporter.

Science.gov (United States)

Zhang, Ji-Long; Zheng, Qing-Chuan; Yu, Li-Ying; Li, Zheng-Qiang; Zhang, Hong-Xing

2016-08-22

Substrate transport across a membrane accomplished by a secondary active transporter (SAT) is essential to the normal physiological function of living cells. In the present research, a series of all-atom molecular dynamics (MD) simulations under different electric field (EF) strengths was performed to investigate the effect of an external EF on the substrate transport of an SAT. The results show that EF both affects the interaction between substrate and related protein's residues by changing their conformations and tunes the timeline of the transport event, which collectively reduces the height of energy barrier for substrate transport and results in the appearance of two intermediate conformations under the existence of an external EF. Our work spotlights the crucial influence of external EFs on the substrate transport of SATs and could provide a more penetrating understanding of the substrate transport mechanism of SATs.

External corners as heat bridges

Energy Technology Data Exchange (ETDEWEB)

Berber, J.

1984-08-01

The maximum additional heat loss in vertical external corners depending on wall thickness is determined. In order to amire at a low k-value, a much smaller wall thickness is required in externally insulated walls than in monolithic constructions; the greater loss of heat bridge with external insulation stands in contrast to a higher loss in thick, monolithic walls. In relation to total losses, the additional losses through external corners are practically negligible.

Aboriginal research coalition externalities associated with energy production: Types, measures and integration

International Nuclear Information System (INIS)

Goodman, I.

1992-01-01

A system that has evolved to determine the environmental externalities associated with energy generation is described. The system involves identification and understanding of the activity being considered (power generation from a specific type of plant), effects such as air pollution, measures such as pollution control that can influence the levels of the preceding effects, the resources affected, impacts on human resource uses, and the values humans place on the use of the resources. Considerations in estimating external costs are then discussed. These include property rights, air emissions, electromagnetic fields, pollution control effectiveness and costs, valuation of air emissions, water quality and quantity, effects on fisheries and recreational activities, and effects of dams and inundation. A least-cost, or integrated management process, selects the combination of electricity supply and demand sources that have the least social cost. Total externality costs are estimated, based on emissions or effects from each source multiplied by unit costs, and control measures selected. The external costs are combined with the usual fixed and variable cost calculations to provide a total social cost measure. This monetization procedure allows a complete accounting of all costs to society on an equal basis. 53 refs., 4 figs

MO-B-BRB-02: 3D Dosimetry in the Clinic: IMRT Technique Validation in Sweden

Energy Technology Data Exchange (ETDEWEB)

Ceberg, S. [Lund University (Sweden)

2016-06-15

irradiated volume can help understand interplay effects during TomoTherapy or VMAT. Titania Juang: Special techniques in the clinic and research Understand the potential for 3D dosimetry in validating dose accumulation in deformable systems, and Observe the benefits of high resolution measurements for precision therapy in SRS and in MicroSBRT for small animal irradiators Geoffrey S. Ibbott: 3D Dosimetry in end-to-end dosimetry QA Understand the potential for 3D dosimetry for end-to-end radiation therapy process validation in the in-house and external credentialing setting. Canadian Institutes of Health Research; L. Schreiner, Modus QA, London, ON, Canada; T. Juang, NIH R01CA100835.

MO-B-BRB-02: 3D Dosimetry in the Clinic: IMRT Technique Validation in Sweden

International Nuclear Information System (INIS)

Ceberg, S.

2016-01-01

irradiated volume can help understand interplay effects during TomoTherapy or VMAT. Titania Juang: Special techniques in the clinic and research Understand the potential for 3D dosimetry in validating dose accumulation in deformable systems, and Observe the benefits of high resolution measurements for precision therapy in SRS and in MicroSBRT for small animal irradiators Geoffrey S. Ibbott: 3D Dosimetry in end-to-end dosimetry QA Understand the potential for 3D dosimetry for end-to-end radiation therapy process validation in the in-house and external credentialing setting. Canadian Institutes of Health Research; L. Schreiner, Modus QA, London, ON, Canada; T. Juang, NIH R01CA100835

Deflection modeling of permanent magnet spherical chains in the presence of external magnetic fields

Energy Technology Data Exchange (ETDEWEB)

O' Donoghue, Kilian, E-mail: kilianod@rennes.ucc.ie; Cantillon-Murphy, Pádraig, E-mail: padraig@alum.mit.edu

2013-10-15

This work examines the interaction of permanently magnetised spheres in the presence of external magnetic fields at the millimetre scale. Static chain formation and deflection models are described for N spheres in the presence of an external magnetic field. Analytical models are presented for the two sphere case by neglecting the effects of magnetocrystalline anisotropy while details of a numerical approach to solve a chain of N spheres are shown. The model is experimentally validated using chain deflections in 4.5 mm diameter spheres in groups of 2, 3 and 4 magnets in the presence of uniform magnetic fields, neglecting gravitational effects, with good agreement between the theoretical model and experimental results. This spherical chain structure could be used as an end effector for catheters as a deflection mechanism for magnetic guidance. The spherical point contacts result in large deflections for navigation around tight corners in endoluminal minimally invasive clinical applications. - Highlights: • We model the interaction of magnetic spheres with uniform external fields. • Analytical models are presented for two spheres interacting with an external field. • Numerical methods are used to model the interaction of N spheres in chain formations. • These models are tested experimentally. • We report good agreement between experiment and theory.

Deflection modeling of permanent magnet spherical chains in the presence of external magnetic fields

International Nuclear Information System (INIS)

O'Donoghue, Kilian; Cantillon-Murphy, Pádraig

2013-01-01

This work examines the interaction of permanently magnetised spheres in the presence of external magnetic fields at the millimetre scale. Static chain formation and deflection models are described for N spheres in the presence of an external magnetic field. Analytical models are presented for the two sphere case by neglecting the effects of magnetocrystalline anisotropy while details of a numerical approach to solve a chain of N spheres are shown. The model is experimentally validated using chain deflections in 4.5 mm diameter spheres in groups of 2, 3 and 4 magnets in the presence of uniform magnetic fields, neglecting gravitational effects, with good agreement between the theoretical model and experimental results. This spherical chain structure could be used as an end effector for catheters as a deflection mechanism for magnetic guidance. The spherical point contacts result in large deflections for navigation around tight corners in endoluminal minimally invasive clinical applications. - Highlights: • We model the interaction of magnetic spheres with uniform external fields. • Analytical models are presented for two spheres interacting with an external field. • Numerical methods are used to model the interaction of N spheres in chain formations. • These models are tested experimentally. • We report good agreement between experiment and theory

Validation of a new mortality risk prediction model for people 65 years and older in northwest Russia: The Crystal risk score.

Science.gov (United States)

Turusheva, Anna; Frolova, Elena; Bert, Vaes; Hegendoerfer, Eralda; Degryse, Jean-Marie

2017-07-01

Prediction models help to make decisions about further management in clinical practice. This study aims to develop a mortality risk score based on previously identified risk predictors and to perform internal and external validations. In a population-based prospective cohort study of 611 community-dwelling individuals aged 65+ in St. Petersburg (Russia), all-cause mortality risks over 2.5 years follow-up were determined based on the results obtained from anthropometry, medical history, physical performance tests, spirometry and laboratory tests. C-statistic, risk reclassification analysis, integrated discrimination improvement analysis, decision curves analysis, internal validation and external validation were performed. Older adults were at higher risk for mortality [HR (95%CI)=4.54 (3.73-5.52)] when two or more of the following components were present: poor physical performance, low muscle mass, poor lung function, and anemia. If anemia was combined with high C-reactive protein (CRP) and high B-type natriuretic peptide (BNP) was added the HR (95%CI) was slightly higher (5.81 (4.73-7.14)) even after adjusting for age, sex and comorbidities. Our models were validated in an external population of adults 80+. The extended model had a better predictive capacity for cardiovascular mortality [HR (95%CI)=5.05 (2.23-11.44)] compared to the baseline model [HR (95%CI)=2.17 (1.18-4.00)] in the external population. We developed and validated a new risk prediction score that may be used to identify older adults at higher risk for mortality in Russia. Additional studies need to determine which targeted interventions improve the outcomes of these at-risk individuals. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrasound comparison of external and internal neck anatomy with the LMA Unique.

Science.gov (United States)

Lee, Steven M; Wojtczak, Jacek A; Cattano, Davide

2017-12-01

Internal neck anatomy landmarks and their relation after placement of an extraglottic airway devices have not been studied extensively by the use of ultrasound. Based on our group experience with external landmarks as well as internal landmarks evaluation with other techniques, we aimed use ultrasound to analyze the internal neck anatomy landmarks and the related changes due to the placement of the Laryngeal Mask Airway Unique. Observational pilot investigation. Non-obese adult patients with no evidence of airway anomalies, were recruited. External neck landmarks were measured based on a validated and standardized method by tape. Eight internal anatomical landmarks, reciprocal by the investigational hypothesis to the external landmarks, were also measured by ultrasound guidance. The internal landmarks were re-measured after optimal placement and inflation of the extraglottic airway devices cuff Laryngeal Mask Airway Unique. Six subjects were recruited. Ultrasound measurements of hyoid-mental distance, thyroid-cricoid distance, thyroid height, and thyroid width were found to be significantly ( p internal neck anatomy. The induced changes and respective specific internal neck anatomy landmarks could help to design devices that would modify their shape accordingly to areas of greatest displacement. Also, while external neck landmark measurements overestimate their respective internal neck landmarks, as we previously reported, the concordance of each measurement and their respective conversion factor could continue to be of help in sizing extraglottic airway devices. Due to the pilot nature of the study, more investigations are warranted.

Data collection, validation, and description for the Oak Ridge nuclear facilities mortality study

International Nuclear Information System (INIS)

Watkins, J.P.; Reagan, J.L.; Cragle, D.L.; West, C.M.; Tankersley, W.G.; Crawford-Brown, D.J.

1995-01-01

To investigate the long-term health effects of protracted occupational exposure to low levels of ionizing radiation, a mortality study was initiated by pooling data for 118,588 workers hired between 1943 and 1982, at three Department of Energy (DOE) facilities in Oak Ridge, Tennessee, with follow-up through 1984. Topics for this discussion will include issues involving the collection and validation of data for individuals in the study cohort, and characteristics of their demographic and radiation exposure data. Since the data were compiled between the late 1960s and the present under the direction of several principal investigators, it was essential to verify data precision and to understand how exposure data were generated prior to beginning any analysis. A stratified random sample of workers in the cohort was chosen for verification of their computerized data as it appeared in the database. Original source documents were reviewed to verify demographic data, as well as internal and external radiation exposure data. Extensive effort was expended to document the personal radiation monitoring policies and types of dosimeters used at each facility over the 42 years included in the study. Characteristics of internal and external exposure data by facility and year were examined by graphical methods with the intent of combining these monitoring data over time and across facilities

Development and Validation of a Risk Score Predicting Substantial Weight Gain over 5 Years in Middle-Aged European Men and Women

DEFF Research Database (Denmark)

Steffen, Annika; Sørensen, Thorkild I.A.; Knüppel, Sven

2013-01-01

Identifying individuals at high risk of excess weight gain may help targeting prevention efforts at those at risk of various metabolic diseases associated with weight gain. Our aim was to develop a risk score to identify these individuals and validate it in an external population.......Identifying individuals at high risk of excess weight gain may help targeting prevention efforts at those at risk of various metabolic diseases associated with weight gain. Our aim was to develop a risk score to identify these individuals and validate it in an external population....

Nonequilibrium electrophoresis of an ion-selective microgranule for weak and moderate external electric fields

Science.gov (United States)

Frants, E. A.; Ganchenko, G. S.; Shelistov, V. S.; Amiroudine, S.; Demekhin, E. A.

2018-02-01

Electrokinetics and the movement of charge-selective micro-granules in an electrolyte solution under the influence of an external electric field are investigated theoretically. Straightforward perturbation analysis is applied to a thin electric double layer and a weak external field, while a numerical solution is used for moderate electric fields. The asymptotic solution enables the determination of the salt concentration, electric charge distribution, and electro-osmotic velocity fields. It may also be used to obtain a simple analytical formula for the electrophoretic velocity in the case of quasi-equilibrium electrophoresis (electrophoresis of the first kind). This formula differs from the famous Helmholtz-Smoluchowski relation, which applies to dielectric microparticles, but not to ion-selective granules. Numerical calculations are used to validate the derived formula for weak external electric fields, but for moderate fields, nonlinear effects lead to a significant increase in electrophoretic mobility and to a transition from quasi-equilibrium electrophoresis of the first kind to nonequilibrium electrophoresis of the second kind. Theoretical results are successfully compared with experimental data.

Compromised External Validity: Federally Produced Cannabis Does Not Reflect Legal Markets

OpenAIRE

Torres, Anthony; Du, Gary; Ruthenburg, Travis; Decesare, Kymron; Land, Donald; Hutchison, Kent; Kane, Nolan; Vergara, Daniela; Bidwell, Cinnamon; Gaudino, Reggie

2016-01-01

As the most widely used illicit drug worldwide, and as a source of numerous under-studied pharmacologically-active compounds, a precise understanding of variability in psychological and physiological effects of Cannabis varieties is essential. The National Institute on Drug Abuse (NIDA) is designated as the sole legal producer of Cannabis for use in US research studies. We sought to compare the chemical profiles of Cannabis varieties that are available to consumers in states that have state-l...

Understanding disruptions in tokamaksa)

Science.gov (United States)

Zakharov, Leonid E.; Galkin, Sergei A.; Gerasimov, Sergei N.; contributors, JET-EFDA

2012-05-01

This paper describes progress achieved since 2007 in understanding disruptions in tokamaks, when the effect of plasma current sharing with the wall was introduced into theory. As a result, the toroidal asymmetry of the plasma current measurements during vertical disruption event (VDE) on the Joint European Torus was explained. A new kind of plasma equilibria and mode coupling was introduced into theory, which can explain the duration of the external kink 1/1 mode during VDE. The paper presents first results of numerical simulations using a free boundary plasma model, relevant to disruptions.

False negative rate of syndesmotic injury in pronation-external rotation stage IV ankle fractures

Directory of Open Access Journals (Sweden)

Kwang-Soon Song

2013-01-01

Full Text Available Background: To investigate false negative rate in the diagnosis of diastasis on initial static anteroposterior radiograph and reliability of intraoperative external rotational stress test for detection of concealed disruption of syndesmosis in pronation external rotation (PER stage IV (Lauge-Hansen ankle fractures. Materials and Methods: We prospectively studied 34 PER stage IV ankle fractures between September 2001 and September 2008. Twenty (59% patients show syndesmotic injury on initial anteroposterior radiographs. We performed an intraoperative external rotation stress test in other 14 patients with suspicious PER stage IV ankle fractures, which showed no defined syndesmotic injury on anteroposterior radiographs inspite of a medial malleolar fracture, an oblique fibular fracture above the syndesmosis and fracture of the posterior tubercle of the tibia. Results: All 14 fractures showed different degrees of tibiofibular clear space (TFCS and tibiofibular overlapping (TFO on the external rotation stress test radiograph compared to the initial plain anteroposterior radiograph. It is important to understand the fracture pattern characterstic of PER stage IV ankle fractures even though it appears normal on anteroposterior radiographs, it is to be confirmed for the concealed syndesmotic injury through a routine intraoperative external rotational stress radiograph.

Comparative Effects Of Training In External And Internal Concentration On Two Counseling Behaviors

Science.gov (United States)

Leung, Paul

1973-01-01

A training procedure that appears to facilitate both empathic understanding and selective response to client statements is one built around the training of Zen Buddhist monks. Subjects trained in Zen techniques of external and internal concentration were found to increase their ability in these two counseling behaviors. (Author/LA)

SU-E-J-244: Development and Validation of a Knowledge Based Planning Model for External Beam Radiation Therapy of Locally Advanced Non-Small Cell Lung Cancer

Energy Technology Data Exchange (ETDEWEB)

Liu, Z; Kennedy, A [Sarah Cannon, Nashville, TN (United States); Larsen, E; Hayes, C; Grow, A [North Florida Cancer Center, Gainesville, FL (United States); Bahamondes, S.; Zheng, Y; Wu, X [JFK Comprehensive Cancer Institute, Lake Worth, FL (United States); Choi, M; Pai, S [Good Samaritan Hospital, Los Gatos, CA (United States); Li, J [Doctors Hospital of Augusta, Augusta, GA (United States); Cranford, K [Trident Medical Center, Charleston, SC (United States)

2015-06-15

Purpose: The study aims to develop and validate a knowledge based planning (KBP) model for external beam radiation therapy of locally advanced non-small cell lung cancer (LA-NSCLC). Methods: RapidPlan™ technology was used to develop a lung KBP model. Plans from 65 patients with LA-NSCLC were used to train the model. 25 patients were treated with VMAT, and the other patients were treated with IMRT. Organs-at-risk (OARs) included right lung, left lung, heart, esophagus, and spinal cord. DVH and geometric distribution DVH were extracted from the treated plans. The model was trained using principal component analysis and step-wise multiple regression. Box plot and regression plot tools were used to identify geometric outliers and dosimetry outliers and help fine-tune the model. The validation was performed by (a) comparing predicted DVH boundaries to actual DVHs of 63 patients and (b) using an independent set of treatment planning data. Results: 63 out of 65 plans were included in the final KBP model with PTV volume ranging from 102.5cc to 1450.2cc. Total treatment dose prescription varied from 50Gy to 70Gy based on institutional guidelines. One patient was excluded due to geometric outlier where 2.18cc of spinal cord was included in PTV. The other patient was excluded due to dosimetric outlier where the dose sparing to spinal cord was heavily enforced in the clinical plan. Target volume, OAR volume, OAR overlap volume percentage to target, and OAR out-of-field volume were included in the trained model. Lungs and heart had two principal component scores of GEDVH, whereas spinal cord and esophagus had three in the final model. Predicted DVH band (mean ±1 standard deviation) represented 66.2±3.6% of all DVHs. Conclusion: A KBP model was developed and validated for radiotherapy of LA-NSCLC in a commercial treatment planning system. The clinical implementation may improve the consistency of IMRT/VMAT planning.

Criterion Validity of the Child's Challenging Behavior Scale, Version 2 (CCBS-2).

Science.gov (United States)

Bourke-Taylor, Helen M; Cordier, Reinie; Pallant, Julie F

The Child's Challenging Behavior Scale, Version 2 (CCBS-2), measures maternal rating of a child's challenging behaviors that compromise maternal mental health. The CCBS-2, the Child Behavior Checklist (CBCL), and the Strengths and Difficulties Questionnaire (SDQ) were compared in a sample of typically developing young Australian children. Criterion validity was investigated by correlating the CCBS-2 with "gold standard" measures (CBCL and SDQ subscales). Data were collected in a cross-sectional survey of mothers (N = 336) of children ages 3-9 yr. Correlations with the CBCL externalizing subscales demonstrated moderate (ρ = .46) to strong (ρ = .66) correlations. Correlations with the SDQ externalizing behaviors subscales were moderate (ρ = .35) to strong (ρ = .60). The criterion validity established in this study strengthens the psychometric properties that support ongoing development of the CCBS-2 as an efficient tool that may identify children in need of further evaluation. Copyright © 2018 by the American Occupational Therapy Association, Inc.

Examining assumptions regarding valid electronic monitoring of medication therapy: development of a validation framework and its application on a European sample of kidney transplant patients

Directory of Open Access Journals (Sweden)

Steiger Jürg

2008-02-01

Full Text Available Abstract Background Electronic monitoring (EM is used increasingly to measure medication non-adherence. Unbiased EM assessment requires fulfillment of assumptions. The purpose of this study was to determine assumptions needed for internal and external validity of EM measurement. To test internal validity, we examined if (1 EM equipment functioned correctly, (2 if all EM bottle openings corresponded to actual drug intake, and (3 if EM did not influence a patient's normal adherence behavior. To assess external validity, we examined if there were indications that using EM affected the sample representativeness. Methods We used data from the Supporting Medication Adherence in Renal Transplantation (SMART study, which included 250 adult renal transplant patients whose adherence to immunosuppressive drugs was measured during 3 months with the Medication Event Monitoring System (MEMS. Internal validity was determined by assessing the prevalence of nonfunctioning EM systems, the prevalence of patient-reported discrepancies between cap openings and actual intakes (using contemporaneous notes and interview at the end of the study, and by exploring whether adherence was initially uncharacteristically high and decreased over time (an indication of a possible EM intervention effect. Sample representativeness was examined by screening for differences between participants and non-participants or drop outs on non-adherence. Results Our analysis revealed that some assumptions were not fulfilled: 1 one cap malfunctioned (0.4%, 2 self-reported mismatches between bottle openings and actual drug intake occurred in 62% of the patients (n = 155, and 3 adherence decreased over the first 5 weeks of the monitoring, indicating that EM had a waning intervention effect. Conclusion The validity assumptions presented in this article should be checked in future studies using EM as a measure of medication non-adherence.

Macroeconomic Adjustment in Armenia: The Role of External Factors

OpenAIRE

Van Aarle, Bas

2011-01-01

This paper develops a small macroeconomic model of the Armenian economy. After setting up the model and its estimation, a number of macroeconomic scenarios is analyzed in the form of out-of-sample simulations. We analyze the transmissions in the model of a number of macroeconomic shocks and policy scenarios to obtain a better understanding of their possible effects on the internal and external balance of the Armenian economy. A special focus is put on the role of exchange rate and monetary ma...

The assessment validity of the curriculum in gender and education

Directory of Open Access Journals (Sweden)

Rosa María González

2013-01-01

Full Text Available The study of validity applied to the studies specialized in gender in an education that has been offered by the National Pedagogical University since 1999 basing itself on two major areas: the external validity and internal validity. The first one contemplates four sections that include the review of gender studies in education as a field of knowledge, the comparative analysis of this educational program with similar (national and international, reviewing its relevance to public gender policy and education, as well as an overview of the demands of the professional workplace – the work of specialists in the field.Moreover, the assessment of internal validity followed a strategy that consisted of verifying consistency between course objectives with the overall objective of the curriculum, as well as reviewing the correspondence between the scope proposed for each theme for each course and the characteristics of the graduate profile.

Opportunistic screening for osteoporosis on routine computed tomography? An external validation study

Energy Technology Data Exchange (ETDEWEB)

Buckens, Constantinus F. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Universitair Medisch Centrum Utrecht, Department of Radiology, Utrecht (Netherlands); Dijkhuis, Gawein; Jong, Pim A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Keizer, Bart de [University Medical Center Utrecht, Department of Nuclear Medicine, Utrecht (Netherlands); Verhaar, Harald J. [University Medical Center Utrecht, Department of Geriatric Medicine, Utrecht (Netherlands)

2015-07-15

Opportunistic screening for osteoporosis using computed tomography (CT) examinations that happen to visualise the spine can be used to identify patients with osteoporosis. We sought to verify the diagnostic performance of vertebral Hounsfield unit (HU) measurements on routine CT examinations for diagnosing osteoporosis in a separate, external population. Consecutive patients who underwent a CT examination of the chest or abdomen and had also received a dual-energy X-ray absorptiometry (DXA) test were retrospectively included. CTs were evaluated for vertebral fractures and vertebral attenuation (density) values were measured. Diagnostic performance measures and the area under the receiver operator characteristics curve (AUC) for diagnosing osteoporosis were calculated. Three hundred and two patients with a mean age of 57.9 years were included, of which 82 (27 %) had osteoporosis according to DXA and 65 (22 %) had vertebral fractures. The diagnostic performance for vertebral HU measurements was modest, with a maximal AUC of 0.74 (0.68 - 0.80). At that optimal threshold the sensitivity was 62 % (51 - 72 %) and the specificity was 79 % (74 - 84 %). We confirmed that simple trabecular vertebral density measurements on routine CT contain diagnostic information related to bone mineral density as measured by DXA, albeit with substantially lower diagnostic accuracy than previously reported. (orig.)

Opportunistic screening for osteoporosis on routine computed tomography? An external validation study

International Nuclear Information System (INIS)

Buckens, Constantinus F.; Dijkhuis, Gawein; Jong, Pim A. de; Keizer, Bart de; Verhaar, Harald J.

2015-01-01

Opportunistic screening for osteoporosis using computed tomography (CT) examinations that happen to visualise the spine can be used to identify patients with osteoporosis. We sought to verify the diagnostic performance of vertebral Hounsfield unit (HU) measurements on routine CT examinations for diagnosing osteoporosis in a separate, external population. Consecutive patients who underwent a CT examination of the chest or abdomen and had also received a dual-energy X-ray absorptiometry (DXA) test were retrospectively included. CTs were evaluated for vertebral fractures and vertebral attenuation (density) values were measured. Diagnostic performance measures and the area under the receiver operator characteristics curve (AUC) for diagnosing osteoporosis were calculated. Three hundred and two patients with a mean age of 57.9 years were included, of which 82 (27 %) had osteoporosis according to DXA and 65 (22 %) had vertebral fractures. The diagnostic performance for vertebral HU measurements was modest, with a maximal AUC of 0.74 (0.68 - 0.80). At that optimal threshold the sensitivity was 62 % (51 - 72 %) and the specificity was 79 % (74 - 84 %). We confirmed that simple trabecular vertebral density measurements on routine CT contain diagnostic information related to bone mineral density as measured by DXA, albeit with substantially lower diagnostic accuracy than previously reported. (orig.)

3D FE Analysis of RC Beams Externally Strengthened with SRG/SRP Systems

Directory of Open Access Journals (Sweden)

Francesco Bencardino

2016-05-01

Full Text Available The purpose of this study is to evaluate, through a nonlinear Finite Element (FE analysis, the structural behavior of Reinforced Concrete (RC beams externally strengthened by using Steel Reinforced Grout (SRG and Steel Reinforced Polymer (SRP systems. The parameters taken into account were the external strengthening configuration, with or without U-wrap end anchorages, as well as the strengthening materials. The numerical simulations were carried out by using a three-dimensional (3D FE model. The linear and nonlinear behavior of all materials was modeled by appropriate constitutive laws and the connection between concrete substrate and external reinforcing layer was simulated by means of cohesive surfaces with appropriate bond-slip laws. In order to overcome convergence difficulties, to simulate the quasi-static response of the strengthened RC beams, a dynamic approach was adopted. The numerical results in terms of load-displacement curves, failure modes, and load and strain values at critical stages were validated against some experimental data. As a result, the proposed 3D FE model can be used to predict the structural behavior up to ultimate stage of similar strengthened beams without carrying out experimental tests.

Performance Targets and External Benchmarking

DEFF Research Database (Denmark)

Friis, Ivar; Hansen, Allan; Vámosi, Tamás S.

Research on relative performance measures, transfer pricing, beyond budgeting initiatives, target costing, piece rates systems and value based management has for decades underlined the importance of external benchmarking in performance management. Research conceptualises external benchmarking...... as a market mechanism that can be brought inside the firm to provide incentives for continuous improvement and the development of competitive advances. However, whereas extant research primarily has focused on the importance and effects of using external benchmarks, less attention has been directed towards...... the conditions upon which the market mechanism is performing within organizations. This paper aims to contribute to research by providing more insight to the conditions for the use of external benchmarking as an element in performance management in organizations. Our study explores a particular type of external...

Validity and reliability of the Academic Motivation Scale in a sample of Slovenian students

Directory of Open Access Journals (Sweden)

Melita Puklek Levpušček

2017-02-01

Full Text Available In this study we examined construct validity and reliability of the Academic Motivation Scale, College Version (Academic Motivation Scale, AMS-C 28, Vallerand et al., 1992 and its relationship with gender, certainty of study choice and career goals in Slovenian university students. The theoretical basis of AMS is derived from Self-Determination Theory, which identified different types of motivation on a continuum from amotivation to different types of external motivation and intrinsic (self-determined motivation. The AMS measures multidimensional motivational construct and contains seven scales. The validation sample consisted of 324 students of various studies at the University of Ljubljana. Multigroup confirmatory factor analysis showed an acceptable fit of the original 7-factor structure on Slovenian data and measurement invariance across gender. The highest were correlations among the three factors of intrinsic motivation and among the three factors of external motivation. Current certainty of study choice was positively associated with all three factors of intrinsic motivation and identified regulation, and negatively correlated with amotivation. Extrinsic career goals had low to moderate positive correlations with factors of external motivation while intrinsic career goals correlated positively with the three factors of intrinsic motivation, identified and introjected regulation, and negatively with amotivation. Female students had higher scores on intrinsic motivation to accomplish, and identified and introjected regulation than male students. In sum, the AMS C-28 showed good construct and convergent validity and reliability in Slovenian university context.

Financial Stress, Parental Depressive Symptoms, Parenting Practices, and Children's Externalizing Problem Behaviors: Underlying Processes

Science.gov (United States)

Lee, Chih-Yuan Steven; Lee, Jaerim; August, Gerald J.

2011-01-01

This study examined the relationships among financial stress encountered by families, parents' social support, parental depressive symptoms, parenting practices, and children's externalizing problem behaviors to advance our understanding of the processes by which family financial stress is associated with children's problem behaviors. We also…

External Otitis (Swimmer's Ear)

Science.gov (United States)

... otitis. Fungal external otitis (otomycosis), typically caused by Aspergillus niger or Candida albicans, is less common. Boils are ... in the ear. Fungal external otitis caused by Aspergillus niger usually causes grayish black or yellow dots (called ...

Establishing macroecological trait datasets: digitalization, extrapolation, and validation of diet preferences in terrestrial mammals worldwide

DEFF Research Database (Denmark)

Kissling, W. Daniel; Dalby, Lars; Fløjgaard, Camilla

2014-01-01

, the importance of diet for macroevolutionary and macroecological dynamics remains little explored, partly because of the lack of comprehensive trait datasets. We compiled and evaluated a comprehensive global dataset of diet preferences of mammals (“MammalDIET”). Diet information was digitized from two global...... species within the same genus, or family) and this extrapolation was subsequently validated both internally (with a jack-knife approach applied to the compiled species-level diet data) and externally (using independent species-level diet information from a comprehensive continentwide data source). Finally...... information (48% of all terrestrial mammal species), and only rarely from other species within the same genus (6%) or from family level (8%). Internal and external validation showed that: (1) extrapolations were most reliable for primary food items; (2) several diet categories (“Animal”, “Mammal...

Hydropower externalities: A meta-analysis

International Nuclear Information System (INIS)

Mattmann, Matteo; Logar, Ivana; Brouwer, Roy

2016-01-01

This paper presents a meta-analysis of existing research related to the economic valuation of the external effects of hydropower. A database consisting of 81 observations derived from 29 studies valuing the non-market impacts of hydropower electricity generation is constructed with the main aim to quantify and explain the economic values for positive and negative hydropower externalities. Different meta-regression model specifications are used to test the robustness of significant determinants of non-market values, including different types of hydropower impacts. The explanatory and predictive power of the estimated models is relatively high. Whilst controlling for sample and study characteristics, we find significant evidence for public aversion towards deteriorations of landscape, vegetation and wildlife caused by hydropower projects. There is however only weak evidence of willingness to pay for mitigating these effects. The main positive externality of hydropower generation, the avoidance of greenhouse gas emission, positively influences welfare estimates when combined with the share of hydropower in national energy production. Sensitivity to scope is detected, but not linked to specific externalities or non-market valuation methods. - Highlights: • A global meta-analysis of valuation studies of hydropower externalities is presented. • Positive and negative externalities are distinguished. • Welfare losses due to environmental deteriorations outweigh gains of GHG reductions. • There is only weak evidence of public WTP for mitigating negative externalities. • The non-market values of hydropower externalities are sensitive to scope.

Mathematical model of voltage-current characteristics of Bi(2223)/Ag magnets under an external magnetic field

CERN Document Server

Pitel, J; Lehtonen, J; Kovács, P

2002-01-01

We have developed a mathematical model, which enables us to predict the voltage-current V(I) characteristics of a solenoidal high-temperature superconductor (HTS) magnet subjected to an external magnetic field parallel to the magnet axis. The model takes into account the anisotropy in the critical current-magnetic field (I sub c (B)) characteristic and the n-value of Bi(2223)Ag multifilamentary tape at 20 K. From the power law between the electric field and the ratio of the operating and critical currents, the voltage on the magnet terminals is calculated by integrating the contributions of individual turns. The critical current of each turn, at given values of operating current and external magnetic field, is obtained by simple linear interpolation between the two suitable points of the I sub c (B) characteristic, which corresponds to the angle alpha between the vector of the resulting magnetic flux density and the broad tape face. In fact, the model is valid for any value and orientation of external magneti...

Correlation functions for the fractional generalized Langevin equation in the presence of internal and external noise

International Nuclear Information System (INIS)

Sandev, Trifce; Metzler, Ralf; Tomovski, Živorad

2014-01-01

We study generalized fractional Langevin equations in the presence of a harmonic potential. General expressions for the mean velocity and particle displacement, the mean squared displacement, position and velocity correlation functions, as well as normalized displacement correlation function are derived. We report exact results for the cases of internal and external friction, that is, when the driving noise is either internal and thus the fluctuation-dissipation relation is fulfilled or when the noise is external. The asymptotic behavior of the generalized stochastic oscillator is investigated, and the case of high viscous damping (overdamped limit) is considered. Additional behaviors of the normalized displacement correlation functions different from those for the regular damped harmonic oscillator are observed. In addition, the cases of a constant external force and the force free case are obtained. The validity of the generalized Einstein relation for this process is discussed. The considered fractional generalized Langevin equation may be used to model anomalous diffusive processes including single file-type diffusion

Characterization of functional biopolymers under various external stimuli

Energy Technology Data Exchange (ETDEWEB)

Maleki, Atoosa

2008-07-01

Polymers are large molecules composed of repeating structural units connected by covalent chemical bonds. Biopolymers are a class of polymers produced by living organisms, which exhibit both biocompatible and biodegradable properties. The behavior of a biopolymer in solution is strongly dependent on the chemical and physical structure of the polymer chain, as well as external environmental conditions. To improve biopolymers in the direction of higher performance and better functionality, understanding of their physicochemical behavior and their response to external stimuli are of great importance. Rheology, rheo-small angle light scattering, dynamic light scattering, small angle neutron scattering, and asymmetric flow field-flow fractionation were utilized in this thesis to investigate the properties of hydroxyethyl cellulose and its hydrophobically modified analogue, as well as dextran, hyaluronan, and mucin under different conditions such as temperature, solvent, mechanical stress and strain, and radiation. Different novel hydrogels were prepared by using various chemical cross-linking agents. Specific features of these macromolecules provide them to be used as 'functional' materials, e.g., sensors, actuators, personal care products, enhanced oil recovery, and controlled drug delivery systems (author)

Congenital External Carotid-External Jugular Arteriovenous Fistula: Diagnosis With Contrast-Enhanced Computed Tomography

International Nuclear Information System (INIS)

Faghihi Langroudi, Taraneh; Arjmand Shabestari, Abbas; Pourghorban, Ramin; Khalili Pouya, Ensi

2015-01-01

Arteriovenous fistula (AVF) between the external carotid artery and external jugular vein is extremely rare, with only few cases reported in the literature so far. Most of these AVFs have been either iatrogenic or secondary to previous trauma. Herein, we report a 42-year-old woman with congenital AVF between the external carotid artery and external jugular vein, presenting with palpitation and dyspnea. The patient was suffering from mitral and tricuspid regurgitation. On physical examination, a thrill on the left side of the neck and an audible bruit over the left mandibular angle were detected. The possibility of abnormal AVF was considered and it was confirmed on contrast-enhanced computed tomography (CT), inferring that this modality is not only fast and non-invasive, but also accurate in detecting vascular abnormalities

Understanding Student Teachers' Behavioural Intention to Use Technology: Technology Acceptance Model (TAM) Validation and Testing

Science.gov (United States)

Wong, Kung-Teck; Osman, Rosma bt; Goh, Pauline Swee Choo; Rahmat, Mohd Khairezan

2013-01-01

This study sets out to validate and test the Technology Acceptance Model (TAM) in the context of Malaysian student teachers' integration of their technology in teaching and learning. To establish factorial validity, data collected from 302 respondents were tested against the TAM using confirmatory factor analysis (CFA), and structural equation…

Energy policy and externalities

International Nuclear Information System (INIS)

Bertel, E.; Fraser, P.

2002-01-01

External costs of energy have been assessed in a number of authoritative and reliable studies based upon widely accepted methodologies such as life cycle analysis (LCA). However, although those costs are recognised by most stakeholders and decision makers, results from analytical work on externalities and LCA studies are seldom used in policy making. The International Energy Agency (IEA) and the Nuclear Energy Agency (NEA) convened a joint workshop in November 2001 to offer experts and policy makers an opportunity to present state-of-the-art results from analytical work on externalities and debate issues related to the relevance of external costs and LCA for policy-making purposes. The findings from the workshop highlight the need for further work in the field and the potential rote of international organisations like the IEA and the NEA in this context. (authors)

Externally Verifiable Oblivious RAM

Directory of Open Access Journals (Sweden)

Gancher Joshua

2017-04-01

Full Text Available We present the idea of externally verifiable oblivious RAM (ORAM. Our goal is to allow a client and server carrying out an ORAM protocol to have disputes adjudicated by a third party, allowing for the enforcement of penalties against an unreliable or malicious server. We give a security definition that guarantees protection not only against a malicious server but also against a client making false accusations. We then give modifications of the Path ORAM [15] and Ring ORAM [9] protocols that meet this security definition. These protocols both have the same asymptotic runtimes as the semi-honest original versions and require the external verifier to be involved only when the client or server deviates from the protocol. Finally, we implement externally verified ORAM, along with an automated cryptocurrency contract to use as the external verifier.

Malignant external otitis: CT evaluation

International Nuclear Information System (INIS)

Curtin, H.D.; Wolfe, P.; May, M.

1982-01-01

Malignant external otitis is an aggressive infection caused by Pseudomonas aeruginosa that most often occurs in elderly diabetics. Malignant external otitis often spreads inferiorly from the external canal to involve the subtemporal area and progresses medially towards the petrous apex leading to multiple cranial nerve palsies. The computed tomographic (CT) findings in malignant external otitis include obliteration of the normal fat planes in the subtemporal area as well as patchy destruction of the bony cortex of the mastoid. The point of exit of the various cranial nerves can be identified on CT scans, and the extent of the inflammatory mass correlates well with the clinical findings. Four cases of malignant external otitis are presented. In each case CT provided a good demonstration of involvement of the soft tissues at the base of the skull

Infant attachment disorganization and moderation pathways to level and change in externalizing behavior during preschool ages.

Science.gov (United States)

Wang, Feihong; Willoughby, Michael; Mills-Koonce, Roger; Cox, Martha J

2016-12-01

This research examined the child, parent, and family conditions under which attachment disorganization was related to both level and change in externalizing behavior during preschool among a community sample. Using the ordinary least squares regression, we found that attachment disorganization at 12 months significantly predicted children's externalizing behavior at 36 months and this prediction was not contingent on any other factors tested. For predicting changes in externalizing behavior from 36 to 60 months, we found a significant main effect of family cumulative risk and an interaction effect between attachment disorganization at 12 months and maternal sensitivity at 24 months. Specifically, high disorganization was related to a significant decrease in externalizing behavior from 36 to 60 months when maternal sensitivity at 24 months was high. Our main-effect findings replicated the significant effect of attachment disorganization and cumulative risk on externalizing behavior with preschool-aged children. Our interaction finding provided support for understanding the parenting conditions under which infant attachment disorganization may be related to change in externalizing behavior during preschool ages. Implications of the findings were discussed.

External costs of electricity; Les couts externes de l'electricite

Energy Technology Data Exchange (ETDEWEB)

Rabl, A. [Ecole des Mines de Paris, 75 (France); Spadaro, J.V. [International Atomic Energy Agency (IAEA), Vienna (Austria)

2005-07-01

This article presents a synthesis of the ExternE project (External costs of Energy) of the European community about the external costs of power generation. Pollution impacts are calculated using an 'impact pathways' analysis, i.e. an analysis of the emission - dispersion - dose-response function - cost evaluation chain. Results are presented for different fuel cycles (with several technological variants) with their confidence intervals. The environmental impact costs are particularly high for coal: for instance, in France, for coal-fired power plants it is of the same order as the electricity retail price. For natural gas, this cost is about a third of the one for coal. On the contrary, the environmental impact costs for nuclear and renewable energies are low, typically of few per cent of the electricity price. The main part of these costs corresponds to the sanitary impacts, in particular the untimely mortality. In order to avoid any controversy about the cost evaluation of mortality, the reduction of the expectation of life due to the different fuel cycles is also indicated and the risks linked with nuclear energy are presented using several comparisons. (J.S.)

Diagnosing Students' Understanding of the Nature of Models

Science.gov (United States)

Gogolin, Sarah; Krüger, Dirk

2017-10-01

Students' understanding of models in science has been subject to a number of investigations. The instruments the researchers used are suitable for educational research but, due to their complexity, cannot be employed directly by teachers. This article presents forced choice (FC) tasks, which, assembled as a diagnostic instrument, are supposed to measure students' understanding of the nature of models efficiently, while being sensitive enough to detect differences between individuals. In order to evaluate if the diagnostic instrument is suitable for its intended use, we propose an approach that complies with the demand to integrate students' responses to the tasks into the validation process. Evidence for validity was gathered based on relations to other variables and on students' response processes. Students' understanding of the nature of models was assessed using three methods: FC tasks, open-ended tasks and interviews ( N = 448). Furthermore, concurrent think-aloud protocols ( N = 30) were performed. The results suggest that the method and the age of the students have an effect on their understanding of the nature of models. A good understanding of the FC tasks as well as a convergence in the findings across the three methods was documented for grades eleven and twelve. This indicates that teachers can use the diagnostic instrument for an efficient and, at the same time, valid diagnosis for this group. Finally, the findings of this article may provide a possible explanation for alternative findings from previous studies as a result of specific methods that were used.

The Validity of the WHO-5 as an Early Screening for Apathy in an Elderly Population

Directory of Open Access Journals (Sweden)

Ramona Lucas-Carrasco

2012-01-01

Full Text Available Aim. The objective of our study has been to evaluate the WHO-5 as a new early screening instrument for apathy in a group of elderly persons. Methods. The WHO-5 was compared to the Geriatric Depression Scale (GDS-15. The GDS contains five items measuring well-being and ten items measuring depression. The internal validity of the WHO-5 (total score being a sufficient statistic was evaluated with both parametric and nonparametric item response theory models. The external validity of the WHO-5 and the GDS was evaluated by ROC using depression as index of validity. Results. The item response theory analyses confirmed that the total score of the WHO-5 is a sufficient statistic. The ROC analysis shows an adequate sensitivity (61% and specificity (84%. The GDS15 and its two subscales obtained low sensitivity (25–42%, but high specificity (90–98%. Conclusion. The WHO-5 was found both internally and externally valid when considering decreased positive well-being to be an early indication of apathy reflecting that the wind has begun to be taken out of the “motivation sail.”

How does external technology search become balanced? A three-dimensional approach

DEFF Research Database (Denmark)

Li-Ying, Jason; Wang, Yuandi

2015-01-01

Firms need to search for external knowledge in a balanced way as over-search entails too much risks and uncertainty and local-search does not promise novel opportunities, as the literature has suggested. We conceptually position firms? search behavior within a three-dimensional knowledge search...... space, including cognitive, temporal, and geographic dimensions. We suggest that the balance is no longer a matter of finding optimal search distance along a single dimension. Instead, it becomes an art to maintain balance in a dynamic manner across three dimensions. Using empirical evidence from...... Chinese licensee firms, we show that such a three-dimension balance does exist among firms? practice. The findings in this respect provide promising opportunities for future research, which will significantly contribute to our understanding of how firms search for external knowledge and the implications...

Health-related external cost assessment in Europe: methodological developments from ExternE to the 2013 Clean Air Policy Package.

Science.gov (United States)

van der Kamp, Jonathan; Bachmann, Till M

2015-03-03

"Getting the prices right" through internalizing external costs is a guiding principle of environmental policy making, one recent example being the EU Clean Air Policy Package released at the end of 2013. It is supported by impact assessments, including monetary valuation of environmental and health damages. For over 20 years, related methodologies have been developed in Europe in the Externalities of Energy (ExternE) project series and follow-up activities. In this study, we aim at analyzing the main methodological developments over time from the 1990s until today with a focus on classical air pollution-induced human health damage costs. An up-to-date assessment including the latest European recommendations is also applied. Using a case from the energy sector, we identify major influencing parameters: differences in exposure modeling and related data lead to variations in damage costs of up to 21%; concerning risk assessment and monetary valuation, differences in assessing long-term exposure mortality risks together with assumptions on particle toxicity explain most of the observed changes in damage costs. These still debated influencing parameters deserve particular attention when damage costs are used to support environmental policy making.

Technical basis document for external events

International Nuclear Information System (INIS)

OBERG, B.D.

2003-01-01

This document supports the Tank Farms Documented Safety Analysis and presents the technical basis for the FR-equencies of externally initiated accidents. The consequences of externally initiated events are discussed in other documents that correspond to the accident that was caused by the external event. The external events include aircraft crash, vehicle accident, range fire, and rail accident

Understanding the effects of violent video games on violent crime

OpenAIRE

Cunningham, A. Scott; Engelstätter, Benjamin; Ward, Michael R.

2011-01-01

Psychological studies invariably find a positive relationship between violent video game play and aggression. However, these studies cannot account for either aggressive effects of alternative activities video game playing substitutes for or the possible selection of relatively violent people into playing violent video games. That is, they lack external validity. We investigate the relationship between the prevalence of violent video games and violent crimes. Our results are consistent with t...

External validation of the clinical dehydration scale for children with acute gastroenteritis.

Science.gov (United States)

Bailey, Benoit; Gravel, Jocelyn; Goldman, Ran D; Friedman, Jeremy N; Parkin, Patricia C

2010-06-01

The objective was to validate the clinical dehydration scale (CDS) for children with gastroenteritis in a different pediatric emergency department (ED) from where it was initially derived and validated. A prospective cohort study was performed in a tertiary care pediatric ED over a 1-year period. A sample of triage nurses were trained in applying the CDS. The CDS consists of four clinical characteristics (general appearance, eyes, mucous membranes, and tears), each of which are scored 0, 1, or 2 for a total score of 0 to 8, with 0 representing no dehydration; 1 to 4, some dehydration; and 5 to 8, moderate/severe dehydration. Children 1 month to 5 years of age with vomiting and/or diarrhea who had the CDS documented at triage and a final diagnosis of gastroenteritis, gastritis, or enteritis were enrolled. Exclusion criteria included a chronic disease, treatment with intravenous (IV) rehydration within the previous 24 hours, visit to the ED for the same illness in the 7 days prior to arrival, and diarrhea of more than 10 days' duration. The primary outcome was the length of stay (LOS) in the ED from the time of seeing a physician to discharge, analyzed with a Kruskal-Wallis test. From April 2008 to March 2009, 150 patients with a mean (+/-SD) age of 22 (+/-14) months (range = 4 months to 4 years) were enrolled. Fifty-six patients had no dehydration, 74 had some dehydration, and 20 had moderate/severe dehydration. The median LOS in the ED after being seen by a physician was significantly longer as children appeared more dehydrated according to the CDS: 54 minutes (interquartile range [IQR] = 26-175 minutes), 128 minutes (IQR = 25-334 minutes), and 425 minutes (IQR = 218-673 minutes) for the no, some, and moderate/severe dehydration groups, respectively (p children with gastroenteritis in a different pediatric center than the original one where it was developed. It is a good predictor of LOS in the ED after being seen by a physician. (c) 2010 by the Society for

Affective commitment to the employer brand: Development and validation of a scale

Directory of Open Access Journals (Sweden)

Susana Fernandez-Lores

2016-01-01

Full Text Available In recent years employer branding has become increasingly important as a source of sustainable competitive advantage. Companies are trying to engender affective commitment in the best employees in a global labour market. In this study, we develop and validate a multidimensional scale to measure the strength of an employee's affective commitment to the employer brand in five separate studies. In Studies 1 and 2 the Affective Commitment to the Employer Brand (ACEB scale was developed and tested for its structure, reliability and convergent validity. Study 3 examines additional reliability and discriminant validity. Study 4 provides evidence of external validity. Study 5 examines the scale's nomological validity showing that a positive experience with the employer brand is important in making the employee develop affective commitment towards it. The limitations of the scale and the boundary conditions of its applicability are also discussed.

Internal Cluster Validation on Earthquake Data in the Province of Bengkulu

Science.gov (United States)

Rini, D. S.; Novianti, P.; Fransiska, H.

2018-04-01

K-means method is an algorithm for cluster n object based on attribute to k partition, where k < n. There is a deficiency of algorithms that is before the algorithm is executed, k points are initialized randomly so that the resulting data clustering can be different. If the random value for initialization is not good, the clustering becomes less optimum. Cluster validation is a technique to determine the optimum cluster without knowing prior information from data. There are two types of cluster validation, which are internal cluster validation and external cluster validation. This study aims to examine and apply some internal cluster validation, including the Calinski-Harabasz (CH) Index, Sillhouette (S) Index, Davies-Bouldin (DB) Index, Dunn Index (D), and S-Dbw Index on earthquake data in the Bengkulu Province. The calculation result of optimum cluster based on internal cluster validation is CH index, S index, and S-Dbw index yield k = 2, DB Index with k = 6 and Index D with k = 15. Optimum cluster (k = 6) based on DB Index gives good results for clustering earthquake in the Bengkulu Province.

Externalizing behaviors in preadolescents: Familial risk to externalizing behaviors and perceived parenting styles

NARCIS (Netherlands)

C.J.M. Buschgens (Cathelijne); M.A.G. van Aken (Marcel); S.H.N. Swinkels (Sophie); J. Ormel (Johan Hans); F.C. Verhulst (Frank); J.K. Buitelaar (Jan)

2010-01-01

textabstractThe aim was to investigate the contribution of familial risk to externalizing behaviors (FR-EXT), perceived parenting styles, and their interactions to the prediction of externalizing behaviors in preadolescents. Participants were preadolescents aged 10-12 years who participated in

Self-reported competency--validation of the Norwegian version of the patient competency rating scale for traumatic brain injury.

Science.gov (United States)

Sveen, Unni; Andelic, Nada; Bautz-Holter, Erik; Røe, Cecilie

2015-01-01

To evaluate the psychometric properties of the Norwegian version of the Patient Competency Rating Scale (PCRS) in patients with traumatic brain injury (TBI) at 12 months post-injury. Demographic and injury-related data were registered upon admission to the hospital in 148 TBI patients with mild, moderate, or severe TBI. At 12 months post-injury, competency in activities and global functioning were measured using the PCRS patient version and the Glasgow Outcome Scale-Extended (GOSE). Descriptive reliability statistics, factor analysis and Rasch modeling were applied to explore the psychometric properties of the PCRS. External validity was evaluated using the GOSE. The PCRS can be divided into three subscales that reflect interpersonal/emotional, cognitive, and activities of daily living competency. The three-factor solution explained 56.6% of the variance in functioning. The internal consistency was very good, with a Cronbach's α of 0.95. Item 30, "controlling my laughter", did not load above 0.40 on any factors and did not fit the Rasch model. The external validity of the subscales was acceptable, with correlations between 0.50 and 0.52 with the GOSE. The Norwegian version of the PCRS is reliable, has an acceptable construct and external validity, and can be recommended for use during the later phases of TBI.

Determination of external measurements in aim to solve inverse heat conduction problem in piping

International Nuclear Information System (INIS)

Blanc, G.; Raynaud, M.; Chau, T.H.

1995-01-01

The inverse heat conduction problem (IHCP) to be solved involves with the reconstruction of unknown thermal loadings applied on piping internal wall. Only external temperature measurements are available as data. Different approaches can be found in the literature for solving this ill-posed problem. The most frequently used among them is the function specification method proposed by Professor BECK. However, for multidimensional IHCP, the accuracy of the solution strongly depends on the number of sensors and their location. This work focuses on the determination of minimal number and locations of the external thermocouples to get the most complete estimation of internal heat flux in a straight pipe. It more particularly concerns the preparation of experimental validation tests which will be performed on the ESTHER mock-up of Electricite de France (EDF). (authors). 4 refs., 9 figs

A New Local Bipolar Autoassociative Memory Based on External Inputs of Discrete Recurrent Neural Networks With Time Delay.

Science.gov (United States)

Zhou, Caigen; Zeng, Xiaoqin; Luo, Chaomin; Zhang, Huaguang

In this paper, local bipolar auto-associative memories are presented based on discrete recurrent neural networks with a class of gain type activation function. The weight parameters of neural networks are acquired by a set of inequalities without the learning procedure. The global exponential stability criteria are established to ensure the accuracy of the restored patterns by considering time delays and external inputs. The proposed methodology is capable of effectively overcoming spurious memory patterns and achieving memory capacity. The effectiveness, robustness, and fault-tolerant capability are validated by simulated experiments.In this paper, local bipolar auto-associative memories are presented based on discrete recurrent neural networks with a class of gain type activation function. The weight parameters of neural networks are acquired by a set of inequalities without the learning procedure. The global exponential stability criteria are established to ensure the accuracy of the restored patterns by considering time delays and external inputs. The proposed methodology is capable of effectively overcoming spurious memory patterns and achieving memory capacity. The effectiveness, robustness, and fault-tolerant capability are validated by simulated experiments.

Validation Experiments for Spent-Fuel Dry-Cask In-Basket Convection

International Nuclear Information System (INIS)

Smith, Barton L.

2016-01-01

This work consisted of the following major efforts; 1. Literature survey on validation of external natural convection; 2. Design the experiment; 3. Build the experiment; 4. Run the experiment; 5. Collect results; 6. Disseminate results; and 7. Perform a CFD validation study using the results. We note that while all tasks are complete, some deviations from the original plan were made. Specifically, geometrical changes in the parameter space were skipped in favor of flow condition changes, which were found to be much more practical to implement. Changing the geometry required new as-built measurements, which proved extremely costly and impractical given the time and funds available

Validation Experiments for Spent-Fuel Dry-Cask In-Basket Convection

Energy Technology Data Exchange (ETDEWEB)

Smith, Barton L. [Utah State Univ., Logan, UT (United States). Dept. of Mechanical and Aerospace Engineering

2016-08-16

This work consisted of the following major efforts; 1. Literature survey on validation of external natural convection; 2. Design the experiment; 3. Build the experiment; 4. Run the experiment; 5. Collect results; 6. Disseminate results; and 7. Perform a CFD validation study using the results. We note that while all tasks are complete, some deviations from the original plan were made. Specifically, geometrical changes in the parameter space were skipped in favor of flow condition changes, which were found to be much more practical to implement. Changing the geometry required new as-built measurements, which proved extremely costly and impractical given the time and funds available

Externally Delivered Focused Ultrasound for Renal Denervation.

Science.gov (United States)

Neuzil, Petr; Ormiston, John; Brinton, Todd J; Starek, Zdenek; Esler, Murray; Dawood, Omar; Anderson, Thomas L; Gertner, Michael; Whitbourne, Rob; Schmieder, Roland E

2016-06-27

The aim of this study was to assess clinical safety and efficacy outcomes of renal denervation executed by an externally delivered, completely noninvasive focused therapeutic ultrasound device. Renal denervation has emerged as a potential treatment approach for resistant hypertension. Sixty-nine subjects received renal denervation with externally delivered focused ultrasound via the Kona Medical Surround Sound System. This approach was investigated across 3 consecutive studies to optimize targeting, tracking, and dosing. In the third study, treatments were performed in a completely noninvasive way using duplex ultrasound image guidance to target the therapy. Short- and long-term safety and efficacy were evaluated through use of clinical assessments, magnetic resonance imaging scans prior to and 3 and 24 weeks after renal denervation, and, in cases in which a targeting catheter was used to facilitate targeting, fluoroscopic angiography with contrast. All patients tolerated renal denervation using externally delivered focused ultrasound. Office blood pressure (BP) decreased by 24.6 ± 27.6/9.0 ± 15.0 mm Hg (from baseline BP of 180.0 ± 18.5/97.7 ± 13.7 mm Hg) in 69 patients after 6 months and 23.8 ± 24.1/10.3 ± 13.1 mm Hg in 64 patients with complete 1-year follow-up. The response rate (BP decrease >10 mm Hg) was 75% after 6 months and 77% after 1 year. The most common adverse event was post-treatment back pain, which was reported in 32 of 69 patients and resolved within 72 h in most cases. No intervention-related adverse events involving motor or sensory deficits were reported. Renal function was not altered, and vascular safety was established by magnetic resonance imaging (all patients), fluoroscopic angiography (n = 48), and optical coherence tomography (n = 5). Using externally delivered focused ultrasound and noninvasive duplex ultrasound, image-guided targeting was associated with substantial BP reduction without any major safety signals. Further

Comparison of infection between internal-external and external percutaneous transhepatic biliary drainage in treating patients with malignant obstructive jaundice.

Science.gov (United States)

Xu, Chuan; Huang, Xin-En; Wang, Shu-Xiang; Lv, Peng-Hua; Sun, Ling; Wang, Fu-An

2015-01-01

Percutaneous transhepatic biliary drainage (PTBD) is a form of palliative care for patients with malignant obstructive jaundice. We here compared the infection incidence between internal-external and external drainage for patients with malignant obstructive jaundice. Patients with malignant obstructive jaundice without infection before surgery receiving internal-external or external drainage from January 2008 to July 2014 were recruited. According to percutaneous transhepatic cholangiography (PTC), if the guide wire could pass through the occlusion and enter the duodenum, we recommended internal-external drainage, and external drainage biliary drainage was set up if the occlusion was not crossed. All patients with infection after procedure received a cultivation of blood and a bile bacteriological test. Among 110 patients with malignant obstructive jaundice, 22 (52.4%) were diagnosed with infection after the procedure in the internal-external drainage group, whereas 19 (27.9%) patients were so affected in the external drainage group, the difference being significant (pinternal-external group infection was controlled, as compared to 12 (63.1%) in the external group (pinternal-external group in one month was 42.8%, while this rate in external group was 28.6% (pExternal drainage is a good choice, which could significantly reduce the chance of biliary infection caused by bacteria, and decrease the mortality rate at one month and improve the long-term prognosis.