WorldWideScience

Sample records for understanding external validity

  1. Checklists for external validity

    DEFF Research Database (Denmark)

    Dyrvig, Anne-Kirstine; Kidholm, Kristian; Gerke, Oke

    2014-01-01

    to an implementation setting. In this paper, currently available checklists on external validity are identified, assessed and used as a basis for proposing a new improved instrument. METHOD: A systematic literature review was carried out in Pubmed, Embase and Cinahl on English-language papers without time restrictions...

  2. Understanding the internal and external validity of health literacy interventions: a systematic literature review using the RE-AIM framework.

    Science.gov (United States)

    Allen, Kacie; Zoellner, Jamie; Motley, Monica; Estabrooks, Paul A

    2011-01-01

    We conducted a systematic literature review, using the RE-AIM framework, with the goal of determining what information is available to inform research to practice translation of health promotion interventions developed to address health literacy. Thirty-one articles reflecting 25 trials published between 2000 and 2010 met inclusion criteria. Two researchers coded each article, using a validated RE-AIM (reach, effectiveness/efficacy, adoption, implementation, maintenance) data extraction tool, and group meetings were used to gain consensus on discrepancies. Across all studies (14 randomized controlled trials, 11 quasi-experimental; 24 clinic-based, 1 community-based), the mean level of reporting RE-AIM indicators varied by dimension (reach = 69%; efficacy/ effectiveness = 58%; adoption = 36%; implementation = 35%; maintenance = 11%). Among participants enrolled in the 25 interventions, approximately 38% were identified as low health literate. Only eight of the studies examined health literacy status as a moderator of intervention effectiveness. This review suggests that the current research on health promotion for participants with low health literacy provides insufficient information to conclude whether interventions for health literacy can attract the target population, achieve an effect that is sustainable, or be generalized outside of clinical settings. Recommendations for enhancing the design and reporting of these trials are provided.

  3. Geochemistry Model Validation Report: External Accumulation Model

    Energy Technology Data Exchange (ETDEWEB)

    K. Zarrabi

    2001-09-27

    The purpose of this Analysis and Modeling Report (AMR) is to validate the External Accumulation Model that predicts accumulation of fissile materials in fractures and lithophysae in the rock beneath a degrading waste package (WP) in the potential monitored geologic repository at Yucca Mountain. (Lithophysae are voids in the rock having concentric shells of finely crystalline alkali feldspar, quartz, and other materials that were formed due to entrapped gas that later escaped, DOE 1998, p. A-25.) The intended use of this model is to estimate the quantities of external accumulation of fissile material for use in external criticality risk assessments for different types of degrading WPs: U.S. Department of Energy (DOE) Spent Nuclear Fuel (SNF) codisposed with High Level Waste (HLW) glass, commercial SNF, and Immobilized Plutonium Ceramic (Pu-ceramic) codisposed with HLW glass. The scope of the model validation is to (1) describe the model and the parameters used to develop the model, (2) provide rationale for selection of the parameters by comparisons with measured values, and (3) demonstrate that the parameters chosen are the most conservative selection for external criticality risk calculations. To demonstrate the applicability of the model, a Pu-ceramic WP is used as an example. The model begins with a source term from separately documented EQ6 calculations; where the source term is defined as the composition versus time of the water flowing out of a breached waste package (WP). Next, PHREEQC, is used to simulate the transport and interaction of the source term with the resident water and fractured tuff below the repository. In these simulations the primary mechanism for accumulation is mixing of the high pH, actinide-laden source term with resident water; thus lowering the pH values sufficiently for fissile minerals to become insoluble and precipitate. In the final section of the model, the outputs from PHREEQC, are processed to produce mass of accumulation

  4. Geochemistry Model Validation Report: External Accumulation Model

    International Nuclear Information System (INIS)

    Zarrabi, K.

    2001-01-01

    The purpose of this Analysis and Modeling Report (AMR) is to validate the External Accumulation Model that predicts accumulation of fissile materials in fractures and lithophysae in the rock beneath a degrading waste package (WP) in the potential monitored geologic repository at Yucca Mountain. (Lithophysae are voids in the rock having concentric shells of finely crystalline alkali feldspar, quartz, and other materials that were formed due to entrapped gas that later escaped, DOE 1998, p. A-25.) The intended use of this model is to estimate the quantities of external accumulation of fissile material for use in external criticality risk assessments for different types of degrading WPs: U.S. Department of Energy (DOE) Spent Nuclear Fuel (SNF) codisposed with High Level Waste (HLW) glass, commercial SNF, and Immobilized Plutonium Ceramic (Pu-ceramic) codisposed with HLW glass. The scope of the model validation is to (1) describe the model and the parameters used to develop the model, (2) provide rationale for selection of the parameters by comparisons with measured values, and (3) demonstrate that the parameters chosen are the most conservative selection for external criticality risk calculations. To demonstrate the applicability of the model, a Pu-ceramic WP is used as an example. The model begins with a source term from separately documented EQ6 calculations; where the source term is defined as the composition versus time of the water flowing out of a breached waste package (WP). Next, PHREEQC, is used to simulate the transport and interaction of the source term with the resident water and fractured tuff below the repository. In these simulations the primary mechanism for accumulation is mixing of the high pH, actinide-laden source term with resident water; thus lowering the pH values sufficiently for fissile minerals to become insoluble and precipitate. In the final section of the model, the outputs from PHREEQC, are processed to produce mass of accumulation

  5. Relabeling Internal and External Validity for Applied Social Scientists.

    Science.gov (United States)

    Campbell, Donald T.

    1986-01-01

    Confusion about the meaning of validity in quasi-experimental research can be addressed by carefully relabeling types of validity. Internal validity can more aptly be termed "local molar causal validity." More tentatively, the "principle of proximal similarity" can be substituted for the concept of external validity. (Author)

  6. Reconceptualising the external validity of discrete choice experiments.

    Science.gov (United States)

    Lancsar, Emily; Swait, Joffre

    2014-10-01

    External validity is a crucial but under-researched topic when considering using discrete choice experiment (DCE) results to inform decision making in clinical, commercial or policy contexts. We present the theory and tests traditionally used to explore external validity that focus on a comparison of final outcomes and review how this traditional definition has been empirically tested in health economics and other sectors (such as transport, environment and marketing) in which DCE methods are applied. While an important component, we argue that the investigation of external validity should be much broader than a comparison of final outcomes. In doing so, we introduce a new and more comprehensive conceptualisation of external validity, closely linked to process validity, that moves us from the simple characterisation of a model as being or not being externally valid on the basis of predictive performance, to the concept that external validity should be an objective pursued from the initial conceptualisation and design of any DCE. We discuss how such a broader definition of external validity can be fruitfully used and suggest innovative ways in which it can be explored in practice.

  7. Review of external validity reporting in childhood obesity prevention research.

    Science.gov (United States)

    Klesges, Lisa M; Dzewaltowski, David A; Glasgow, Russell E

    2008-03-01

    The translation and dissemination of prevention intervention evidence into practice is needed to address significant public health issues such as childhood obesity. Increased attention to and reporting of external validity information in research publications would allow for better understanding of generalizability issues relevant to successful translation. To demonstrate this potential, recent reports of childhood obesity prevention interventions were evaluated on the extent to which external validity dimensions were reported. Childhood obesity prevention studies that were controlled, long-term research trials published between 1980 and 2004 that reported a behavioral target of physical activity and/or healthy eating along with at least one anthropometric outcome were identified in 2005. Studies were summarized between 2005 and 2006 using review criteria developed by Green and Glasgow in 2006. Nineteen publications met selection criteria. In general, all studies lacked full reporting on potential generalizability and dissemination elements. Median reporting over all elements was 34.5%; the mode was 0% with a range of 0% to 100%. Most infrequent were reports of setting level selection criteria and representativeness, characteristics regarding intervention staff, implementation of intervention content, costs, and program sustainability. The evidence base for future prevention interventions can be improved by enhancing the reporting of contextual and generalizability elements central to translational research. Such efforts face practical hurdles but could provide additional explanation for variability in intervention outcomes, insights into successful adaptations of interventions, and help guide policy decisions.

  8. Interaction of Theory and Practice to Assess External Validity.

    Science.gov (United States)

    Leviton, Laura C; Trujillo, Mathew D

    2016-01-18

    Variations in local context bedevil the assessment of external validity: the ability to generalize about effects of treatments. For evaluation, the challenges of assessing external validity are intimately tied to the translation and spread of evidence-based interventions. This makes external validity a question for decision makers, who need to determine whether to endorse, fund, or adopt interventions that were found to be effective and how to ensure high quality once they spread. To present the rationale for using theory to assess external validity and the value of more systematic interaction of theory and practice. We review advances in external validity, program theory, practitioner expertise, and local adaptation. Examples are provided for program theory, its adaptation to diverse contexts, and generalizing to contexts that have not yet been studied. The often critical role of practitioner experience is illustrated in these examples. Work is described that the Robert Wood Johnson Foundation is supporting to study treatment variation and context more systematically. Researchers and developers generally see a limited range of contexts in which the intervention is implemented. Individual practitioners see a different and often a wider range of contexts, albeit not a systematic sample. Organized and taken together, however, practitioner experiences can inform external validity by challenging the developers and researchers to consider a wider range of contexts. Researchers have developed a variety of ways to adapt interventions in light of such challenges. In systematic programs of inquiry, as opposed to individual studies, the problems of context can be better addressed. Evaluators have advocated an interaction of theory and practice for many years, but the process can be made more systematic and useful. Systematic interaction can set priorities for assessment of external validity by examining the prevalence and importance of context features and treatment

  9. External Validity: The Next Step for Systematic Reviews?

    Science.gov (United States)

    Avellar, Sarah A; Thomas, Jaime; Kleinman, Rebecca; Sama-Miller, Emily; Woodruff, Sara E; Coughlin, Rebecca; Westbrook, T'Pring R

    2016-08-31

    Systematic reviews-which identify, assess, and summarize existing research-are usually designed to determine whether research shows that an intervention has evidence of effectiveness, rather than whether an intervention will work under different circumstances. The reviews typically focus on the internal validity of the research and do not consistently incorporate information on external validity into their conclusions. In this article, we focus on how systematic reviews address external validity. We conducted a brief scan of 19 systematic reviews and a more in-depth examination of information presented in a systematic review of home visiting research. We found that many reviews do not provide information on generalizability, such as statistical representativeness, but focus on factors likely to increase heterogeneity (e.g., numbers of studies or settings) and report on context. The latter may help users decide whether the research characteristics-such as sample demographics or settings-are similar to their own. However, we found that differences in reporting, such as which variables are included and how they are measured, make it difficult to summarize across studies or make basic determinations of sample characteristics, such as whether the majority of a sample was unemployed or married. Evaluation research and systematic reviews would benefit from reporting guidelines for external validity to ensure that key information is reported across studies. © The Author(s) 2016.

  10. Development and external validation of a new PTA assessment scale

    Directory of Open Access Journals (Sweden)

    Jacobs Bram

    2012-08-01

    Full Text Available Abstract Background Post-traumatic amnesia (PTA is a key symptom of traumatic brain injury (TBI. Accurate assessment of PTA is imperative in guiding clinical decision making. Our aim was to develop and externally validate a short, examiner independent and practical PTA scale, by selecting the most discriminative items from existing scales and using a three-word memory test. Methods Mild, moderate and severe TBI patients and control subjects were assessed in two separate cohorts, one for derivation and one for validation, using a questionnaire comprised of items from existing PTA scales. We tested which individual items best discriminated between TBI patients and controls, represented by sensitivity and specificity. We then created our PTA scale based on these results. This new scale was externally evaluated for its discriminative value using Receiver Operating Characteristic (ROC analysis and compared to existing PTA scales. Results The derivation cohort included 126 TBI patients and 31 control subjects; the validation cohort consisted of 132 patients and 30 controls. A set of seven items was eventually selected to comprise the new PTA scale: age, name of hospital, time, day of week, month, mode of transport and recall of three words. This scale demonstrated adequate discriminative values compared to existing PTA scales on three consecutive administrations in the validation cohort. Conclusion We introduce a valid, practical and examiner independent PTA scale, which is suitable for mild TBI patients at the emergency department and yet still valuable for the follow-up of more severely injured TBI patients.

  11. Geographic Information Systems to Assess External Validity in Randomized Trials.

    Science.gov (United States)

    Savoca, Margaret R; Ludwig, David A; Jones, Stedman T; Jason Clodfelter, K; Sloop, Joseph B; Bollhalter, Linda Y; Bertoni, Alain G

    2017-08-01

    To support claims that RCTs can reduce health disparities (i.e., are translational), it is imperative that methodologies exist to evaluate the tenability of external validity in RCTs when probabilistic sampling of participants is not employed. Typically, attempts at establishing post hoc external validity are limited to a few comparisons across convenience variables, which must be available in both sample and population. A Type 2 diabetes RCT was used as an example of a method that uses a geographic information system to assess external validity in the absence of a priori probabilistic community-wide diabetes risk sampling strategy. A geographic information system, 2009-2013 county death certificate records, and 2013-2014 electronic medical records were used to identify community-wide diabetes prevalence. Color-coded diabetes density maps provided visual representation of these densities. Chi-square goodness of fit statistic/analysis tested the degree to which distribution of RCT participants varied across density classes compared to what would be expected, given simple random sampling of the county population. Analyses were conducted in 2016. Diabetes prevalence areas as represented by death certificate and electronic medical records were distributed similarly. The simple random sample model was not a good fit for death certificate record (chi-square, 17.63; p=0.0001) and electronic medical record data (chi-square, 28.92; p<0.0001). Generally, RCT participants were oversampled in high-diabetes density areas. Location is a highly reliable "principal variable" associated with health disparities. It serves as a directly measurable proxy for high-risk underserved communities, thus offering an effective and practical approach for examining external validity of RCTs. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  12. Validation of a scenario-based assessment of critical thinking using an externally validated tool.

    Science.gov (United States)

    Buur, Jennifer L; Schmidt, Peggy; Smylie, Dean; Irizarry, Kris; Crocker, Carlos; Tyler, John; Barr, Margaret

    2012-01-01

    With medical education transitioning from knowledge-based curricula to competency-based curricula, critical thinking skills have emerged as a major competency. While there are validated external instruments for assessing critical thinking, many educators have created their own custom assessments of critical thinking. However, the face validity of these assessments has not been challenged. The purpose of this study was to compare results from a custom assessment of critical thinking with the results from a validated external instrument of critical thinking. Students from the College of Veterinary Medicine at Western University of Health Sciences were administered a custom assessment of critical thinking (ACT) examination and the externally validated instrument, California Critical Thinking Skills Test (CCTST), in the spring of 2011. Total scores and sub-scores from each exam were analyzed for significant correlations using Pearson correlation coefficients. Significant correlations between ACT Blooms 2 and deductive reasoning and total ACT score and deductive reasoning were demonstrated with correlation coefficients of 0.24 and 0.22, respectively. No other statistically significant correlations were found. The lack of significant correlation between the two examinations illustrates the need in medical education to externally validate internal custom assessments. Ultimately, the development and validation of custom assessments of non-knowledge-based competencies will produce higher quality medical professionals.

  13. Internal and external validation of an ESTRO delineation guideline

    DEFF Research Database (Denmark)

    Eldesoky, Ahmed R.; Yates, Esben Svitzer; Nyeng, Tine B

    2016-01-01

    multi-atlas libraries using MIM Maestro™ software. These libraries were used for auto-segmentation in two different patient groups (50 patients from the local institution and 40 patients from other institutions). Dice Similarity Coefficient, Average Hausdorff Distance, difference in volume and time were......Background and purpose To internally and externally validate an atlas based automated segmentation (ABAS) in loco-regional radiation therapy of breast cancer. Materials and methods Structures of 60 patients delineated according to the ESTRO consensus guideline were included in four categorized...

  14. External validity of post-stroke interventional gait rehabilitation studies.

    Science.gov (United States)

    Kafri, Michal; Dickstein, Ruth

    2017-01-01

    Gait rehabilitation is a major component of stroke rehabilitation, and is supported by extensive research. The objective of this review was to examine the external validity of intervention studies aimed at improving gait in individuals post-stroke. To that end, two aspects of these studies were assessed: subjects' exclusion criteria and the ecological validity of the intervention, as manifested by the intervention's technological complexity and delivery setting. Additionally, we examined whether the target population as inferred from the titles/abstracts is broader than the population actually represented by the reported samples. We systematically researched PubMed for intervention studies to improve gait post-stroke, working backwards from the beginning of 2014. Exclusion criteria, the technological complexity of the intervention (defined as either elaborate or simple), setting, and description of the target population in the titles/abstracts were recorded. Fifty-two studies were reviewed. The samples were exclusive, with recurrent stroke, co-morbidities, cognitive status, walking level, and residency being major reasons for exclusion. In one half of the studies, the intervention was elaborate. Descriptions of participants in the title/abstract in almost one half of the studies included only the diagnosis (stroke or comparable terms) and its stage (acute, subacute, and chronic). The external validity of a substantial number of intervention studies about rehabilitation of gait post-stroke appears to be limited by exclusivity of the samples as well as by deficiencies in ecological validity of the interventions. These limitations are not accurately reflected in the titles or abstracts of the studies.

  15. On the external validity of construction bidding experiment

    Directory of Open Access Journals (Sweden)

    Bee Lan Oo

    2016-03-01

    Full Text Available The external validity of experimental studies and in particular, the subject pool effects have been much debated among researchers. The common objections are that the use of student as experimental subjects is invalid as they are likely to be unrepresentative. This paper addresses this methodological aspect in building economics research. It compares the bidding behavioural patterns of experienced construction executives (professionals and student subjects through replication of a bidding experiment that aimed at testing theories. The results show that the student subjects’ bidding behavourial patterns, in terms of decision to bid and mark-up decision, are sufficiently similar to that of the professionals. This suggests that the subject pool per se is not a threat to the external validity of the bidding experiment. In addition, the demonstrated practicality of an experimental approach in testing theories should lead to more use of experimental studies with student subjects in building economics research. It is suggested that experimental and field findings should be seen as complementary in building economics research, as advocated in social sciences.

  16. Population pharmacokinetics of bevacizumab in cancer patients with external validation.

    Science.gov (United States)

    Han, Kelong; Peyret, Thomas; Marchand, Mathilde; Quartino, Angelica; Gosselin, Nathalie H; Girish, Sandhya; Allison, David E; Jin, Jin

    2016-08-01

    Bevacizumab is approved for various cancers. This analysis aimed to comprehensively evaluate bevacizumab pharmacokinetics and the influence of patient variables on bevacizumab pharmacokinetics. Rich and sparse bevacizumab serum concentrations were collected from Phase I through IV studies in early and metastatic cancers. Bevacizumab was given intravenously as single agent or in combination with chemotherapy for single- and multiple-dose schedules. Model-building used 8943 bevacizumab concentrations from 1792 patients with colon/colorectal, non-small cell lung, kidney, pancreatic, breast, prostate and brain cancer. Bevacizumab doses ranged from 1 to 20 mg/kg given once every 1, 2 or 3 weeks. A two-compartment model best described the data. The population estimates of clearance (CL), central volume of distribution (V1) and half-life for a typical 70-kg patient were 9.01 mL/h, 2.88 L and 19.6 days. CL and V1 increased with body weight and were higher in males than females by 14 and 18 %, respectively. CL decreased with increasing albumin and decreasing alkaline phosphatase. The final model was externally validated using 1670 concentrations from 146 Japanese patients that were not used for model-building. Mean prediction errors were -2.1, 3.1 and 1.0 % for concentrations, CL and V1, respectively, confirming adequate predictive performance. A robust bevacizumab pharmacokinetic model was developed and externally validated, which may be used to simulate bevacizumab exposure to optimize dosing strategies. Asian and non-Asian patients exhibited similar bevacizumab pharmacokinetics. Given the similarity in pharmacokinetics among monoclonal antibodies, this may inform pharmacokinetic studies in different ethnic groups for other therapeutic antibodies.

  17. External Validation of the HERNIAscore: An Observational Study.

    Science.gov (United States)

    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.

  18. External Validation of the Liverpool Uveal Melanoma Prognosticator Online.

    Science.gov (United States)

    DeParis, Sarah W; Taktak, Azzam; Eleuteri, Antonio; Enanoria, Wayne; Heimann, Heinrich; Coupland, Sarah E; Damato, Bertil

    2016-11-01

    To validate the Liverpool Uveal Melanoma Prognosticator Online (LUMPO) in a cohort of patients treated at the University of California-San Francisco (UCSF). A retrospective chart review was performed of 390 patients treated between 2002 and 2007 for choroidal melanoma at UCSF. Similar patients (n = 1175) treated at the Liverpool Ocular Oncology Centre (LOOC) were included in the study. The data were analyzed using the model previously developed for LUMPO, an online prognostication tool combining multiple prognostic factors. Main outcome measures included all-cause mortality and melanoma-specific mortality. Reliability of the survival estimates in each group of patients was indicated by the C-indices of discrimination and Hosmer-Lemeshow test. Patients treated at UCSF tended to be younger with thicker tumors, and were more likely to receive proton beam radiotherapy as primary treatment compared to patients at LOOC. There were no significance differences with respect to ciliary body involvement, melanoma cytomorphology, and mitotic counts between the two groups. Death occurred in 140/390 (35%) patients from UCSF and 409/1175 (34%) patients from LOOC, with no difference in overall mortality by Kaplan-Meier analysis (log rank test, P = 0.503). For all-cause mortality and melanoma-specific mortality, the C-index of discrimination and Hosmer-Lemeshow test at 5 years after treatment indicated good discrimination performance of the model, with no statistically significant difference between observed and predicted survival. Despite differences between the two cohorts, external validation in patients treated at UCSF indicates that LUMPO estimated the all-cause and melanoma-specific mortality well.

  19. When All Children Comprehend: Increasing the External Validity of Narrative Comprehension Development Research

    Directory of Open Access Journals (Sweden)

    Silas E. Burris

    2014-03-01

    Full Text Available Narratives, also called stories, can be found in conversations, children’s play interactions, reading material, and television programs. From infancy to adulthood, narrative comprehension processes interpret events and inform our understanding of physical and social environments. These processes have been extensively studied to ascertain the multifaceted nature of narrative comprehension. From this research we know that three overlapping processes (i.e., knowledge integration, goal structure understanding, and causal inference generation proposed by the constructionist paradigm are necessary for narrative comprehension, narrative comprehension has a predictive relationship with children’s later reading performance, and comprehension processes are generalizable to other contexts. Much of the previous research has emphasized internal and predictive validity; thus, limiting the generalizability of previous findings. We are concerned these limitations may be excluding underrepresented populations from benefits and implications identified by early comprehension processes research. This review identifies gaps in extant literature regarding external validity and argues for increased emphasis on externally valid research. We highlight limited research on narrative comprehension processes in children from low-income and minority populations, and argue for changes in comprehension assessments. Specifically, we argue both on- and off-line assessments should be used across various narrative types (e.g., picture books, televised narratives with traditionally underserved and underrepresented populations. We propose increasing the generalizability narrative comprehension processes research can inform persistent reading achievement gaps, and have practical implications for how children learn from narratives.

  20. When all children comprehend: increasing the external validity of narrative comprehension development research

    Science.gov (United States)

    Burris, Silas E.; Brown, Danielle D.

    2014-01-01

    Narratives, also called stories, can be found in conversations, children's play interactions, reading material, and television programs. From infancy to adulthood, narrative comprehension processes interpret events and inform our understanding of physical and social environments. These processes have been extensively studied to ascertain the multifaceted nature of narrative comprehension. From this research we know that three overlapping processes (i.e., knowledge integration, goal structure understanding, and causal inference generation) proposed by the constructionist paradigm are necessary for narrative comprehension, narrative comprehension has a predictive relationship with children's later reading performance, and comprehension processes are generalizable to other contexts. Much of the previous research has emphasized internal and predictive validity; thus, limiting the generalizability of previous findings. We are concerned these limitations may be excluding underrepresented populations from benefits and implications identified by early comprehension processes research. This review identifies gaps in extant literature regarding external validity and argues for increased emphasis on externally valid research. We highlight limited research on narrative comprehension processes in children from low-income and minority populations, and argue for changes in comprehension assessments. Specifically, we argue both on- and off-line assessments should be used across various narrative types (e.g., picture books, televised narratives) with traditionally underserved and underrepresented populations. We propose increasing the generalizability of narrative comprehension processes research can inform persistent reading achievement gaps, and have practical implications for how children learn from narratives. PMID:24659973

  1. Understanding externalizing behavior from children's personality and parenting characteristics.

    Science.gov (United States)

    Hiramura, Hidetoshi; Uji, Masayo; Shikai, Noriko; Chen, Zi; Matsuoka, Nao; Kitamura, Toshinori

    2010-01-30

    A total of 946 Japanese children in the 5th to 9th grades and their parents were studied in order to investigate the extent to which parenting characteristics (measured by the Parental Bonding Instrument) and the personality of the child (measured by the junior version of the Temperament and Character Inventory) would be associated with the two aspects of the externalizing problems--aggression and delinquency--of the child (measured by the Child Behavior Checklist). A series of regression analyses demonstrated that (1) aggressive children were higher in Novelty Seeking, and delinquent children were higher in Novelty Seeking and lower in Harm Avoidance, and (2) both aggressive and delinquent children were characterised by low maternal care, paternal over-protection, and low maternal overprotection. A structural equation model confirmed these findings except for the link between the two externalizing behaviour scores and the maternal care. Moreover, it was suggested that Novelty seeking of the child would be predicted by low parental care and low paternal and high maternal overprotection. The children's aggression and delinquency could, to some extent, be explainable by their temperament patterns and parental characteristics.

  2. External validation of urinary PCA3-based nomograms to individually predict prostate biopsy outcome

    NARCIS (Netherlands)

    Auprich, Marco; Haese, Alexander; Walz, Jochen; Pummer, Karl; de la Taille, Alexandre; Graefen, Markus; de Reijke, Theo; Fisch, Margit; Kil, Paul; Gontero, Paolo; Irani, Jacques; Chun, Felix K.-H.

    2010-01-01

    Prior to safely adopting risk stratification tools, their performance must be tested in an external patient cohort. To assess accuracy and generalizability of previously reported, internally validated, prebiopsy prostate cancer antigen 3 (PCA3) gene-based nomograms when applied to a large, external,

  3. External validation of clinical decision rules for children with wrist trauma

    NARCIS (Netherlands)

    Mulders, Marjolein A. M.; Walenkamp, Monique M. J.; Dubois, Bente F. H.; Slaar, Annelie; Goslings, J. Carel; Schep, Niels W. L.

    2017-01-01

    Clinical decision rules help to avoid potentially unnecessary radiographs of the wrist, reduce waiting times and save costs. The primary aim of this study was to provide an overview of all existing non-validated clinical decision rules for wrist trauma in children and to externally validate these

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

    NARCIS (Netherlands)

    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

  5. GATE/GEANT4 validation for external radiotherapy; Validation de Gate/Geant4 pour la radiotherapie externe

    Energy Technology Data Exchange (ETDEWEB)

    Perrot, Y.; Breton, V.; Donnarieix, D.; Maigne, L. [Laboratoire de Physique Corpusculaire, 24 avenue des Landais 63177 Aubiere cedex (France); Donnarieix, D. [Centre Jean Perrin, Unite de Physique Medicale, Departement de Radiotherapie-Curietherapie, 58 rue Montalembert, 63011 Clermont-Ferrand cedex (France)

    2010-07-01

    The authors summarize a study in which a Monte Carlo simulation platform (GATE) based on the GEANT4 code has been used for dose rate assessments in radiotherapy. In order to validate the last GATE version for radiotherapy, realistic clinic conditions have been modelled, notably electron beam and low energy physical processes. Computed results and measurements are compared for dose distributions in different types of phantoms

  6. External validation of scoring instruments for evaluating pediatric resuscitation.

    Science.gov (United States)

    Levy, Arielle; Donoghue, Aaron; Bailey, Benoit; Thompson, Nathan; Jamoulle, Olivier; Gagnon, Robert; Gravel, Jocelyn

    2014-12-01

    Although many methods have been proposed to assess clinical performance during resuscitation, robust and generalizable metrics are still lacking. Further research is necessary to develop validated clinical performance assessment tools and show an improvement in outcomes after training. We aimed to establish evidence for validity of a previously published scoring instrument--the Clinical Performance Tool (CPT)--designed to evaluate clinical performance during simulated pediatric resuscitations. This was a prospective experimental trial performed in the simulation laboratory of a pediatric tertiary care facility, with a pretest/posttest design that assessed residents before and after pediatric advanced life support (PALS) certification. Thirteen postgraduate year 1 (PGY1) and 11 PGY3 pediatric residents completed 5 simulated pediatric resuscitation scenarios each during 2 consecutive sessions; between the 2 sessions, they completed a full PALS certification course. All sessions were video recorded. Sessions were scored by raters using the CPT; total scores were expressed as a percentage of maximum points possible for each scenario. Validity evidence was established and interpreted according to Messick's framework. Evidence regarding relations to other variables was assessed by calculating differences in scores between pre-PALS and post-PALS certification and PGY1 and PGY3 using a repeated-measures analysis of variance test. Internal structure evidence was established by assessing interrater reliability using intraclass correlation coefficients (ICCs) for each scenario, a G-study, and a variance component analysis of individual measurement facets (scenarios, raters, and occasions) and associated interactions. Overall scores for the entire study cohort improved by 10% after PALS training. Scores improved by 9.9% (95% confidence interval [CI], 4.5-15.4) for the pulseless nonshockable arrest (ICC, 0.85; 95% CI, 0.74-0.92), 14.6% (95% CI, 6.7-22.4) for the pulseless

  7. Pragmatic controlled clinical trials in primary care: the struggle between external and internal validity

    Directory of Open Access Journals (Sweden)

    Birtwhistle Richard

    2003-12-01

    Full Text Available Abstract Background Controlled clinical trials of health care interventions are either explanatory or pragmatic. Explanatory trials test whether an intervention is efficacious; that is, whether it can have a beneficial effect in an ideal situation. Pragmatic trials measure effectiveness; they measure the degree of beneficial effect in real clinical practice. In pragmatic trials, a balance between external validity (generalizability of the results and internal validity (reliability or accuracy of the results needs to be achieved. The explanatory trial seeks to maximize the internal validity by assuring rigorous control of all variables other than the intervention. The pragmatic trial seeks to maximize external validity to ensure that the results can be generalized. However the danger of pragmatic trials is that internal validity may be overly compromised in the effort to ensure generalizability. We are conducting two pragmatic randomized controlled trials on interventions in the management of hypertension in primary care. We describe the design of the trials and the steps taken to deal with the competing demands of external and internal validity. Discussion External validity is maximized by having few exclusion criteria and by allowing flexibility in the interpretation of the intervention and in management decisions. Internal validity is maximized by decreasing contamination bias through cluster randomization, and decreasing observer and assessment bias, in these non-blinded trials, through baseline data collection prior to randomization, automating the outcomes assessment with 24 hour ambulatory blood pressure monitors, and blinding the data analysis. Summary Clinical trials conducted in community practices present investigators with difficult methodological choices related to maintaining a balance between internal validity (reliability of the results and external validity (generalizability. The attempt to achieve methodological purity can

  8. External validation and comparison of three pediatric clinical dehydration scales.

    Directory of Open Access Journals (Sweden)

    Joshua Jauregui

    Full Text Available OBJECTIVE: To prospectively validate three popular clinical dehydration scales and overall physician gestalt in children with vomiting or diarrhea relative to the criterion standard of percent weight change with rehydration. METHODS: We prospectively enrolled a non-consecutive cohort of children ≤ 18 years of age with an acute episode of diarrhea or vomiting. Patient weight, clinical scale variables and physician clinical impression, or gestalt, were recorded before and after fluid resuscitation in the emergency department and upon hospital discharge. The percent weight change from presentation to discharge was used to calculate the degree of dehydration, with a weight change of ≥ 5% considered significant dehydration. Receiver operating characteristics (ROC curves were constructed for each of the three clinical scales and physician gestalt. Sensitivity and specificity were calculated based on the best cut-points of the ROC curve. RESULTS: We approached 209 patients, and of those, 148 were enrolled and 113 patients had complete data for analysis. Of these, 10.6% had significant dehydration based on our criterion standard. The Clinical Dehydration Scale (CDS and Gorelick scales both had an area under the ROC curve (AUC statistically different from the reference line with AUCs of 0.72 (95% CI 0.60, 0.84 and 0.71 (95% CI 0.57, 0.85 respectively. The World Health Organization (WHO scale and physician gestalt had AUCs of 0.61 (95% CI 0.45, 0.77 and 0.61 (0.44, 0.78 respectively, which were not statistically significant. CONCLUSION: The Gorelick scale and Clinical Dehydration Scale were fair predictors of dehydration in children with diarrhea or vomiting. The World Health Organization scale and physician gestalt were not helpful predictors of dehydration in our cohort.

  9. External validation and comparison of three pediatric clinical dehydration scales.

    Science.gov (United States)

    Jauregui, Joshua; Nelson, Daniel; Choo, Esther; Stearns, Branden; Levine, Adam C; Liebmann, Otto; Shah, Sachita P

    2014-01-01

    To prospectively validate three popular clinical dehydration scales and overall physician gestalt in children with vomiting or diarrhea relative to the criterion standard of percent weight change with rehydration. We prospectively enrolled a non-consecutive cohort of children ≤ 18 years of age with an acute episode of diarrhea or vomiting. Patient weight, clinical scale variables and physician clinical impression, or gestalt, were recorded before and after fluid resuscitation in the emergency department and upon hospital discharge. The percent weight change from presentation to discharge was used to calculate the degree of dehydration, with a weight change of ≥ 5% considered significant dehydration. Receiver operating characteristics (ROC) curves were constructed for each of the three clinical scales and physician gestalt. Sensitivity and specificity were calculated based on the best cut-points of the ROC curve. We approached 209 patients, and of those, 148 were enrolled and 113 patients had complete data for analysis. Of these, 10.6% had significant dehydration based on our criterion standard. The Clinical Dehydration Scale (CDS) and Gorelick scales both had an area under the ROC curve (AUC) statistically different from the reference line with AUCs of 0.72 (95% CI 0.60, 0.84) and 0.71 (95% CI 0.57, 0.85) respectively. The World Health Organization (WHO) scale and physician gestalt had AUCs of 0.61 (95% CI 0.45, 0.77) and 0.61 (0.44, 0.78) respectively, which were not statistically significant. The Gorelick scale and Clinical Dehydration Scale were fair predictors of dehydration in children with diarrhea or vomiting. The World Health Organization scale and physician gestalt were not helpful predictors of dehydration in our cohort.

  10. Checklist for the qualitative evaluation of clinical studies with particular focus on external validity and model validity

    Directory of Open Access Journals (Sweden)

    Vollmar Horst C

    2006-12-01

    Full Text Available Abstract Background It is often stated that external validity is not sufficiently considered in the assessment of clinical studies. Although tools for its evaluation have been established, there is a lack of awareness of their significance and application. In this article, a comprehensive checklist is presented addressing these relevant criteria. Methods The checklist was developed by listing the most commonly used assessment criteria for clinical studies. Additionally, specific lists for individual applications were included. The categories of biases of internal validity (selection, performance, attrition and detection bias correspond to structural, treatment-related and observational differences between the test and control groups. Analogously, we have extended these categories to address external validity and model validity, regarding similarity between the study population/conditions and the general population/conditions related to structure, treatment and observation. Results A checklist is presented, in which the evaluation criteria concerning external validity and model validity are systemised and transformed into a questionnaire format. Conclusion The checklist presented in this article can be applied to both planning and evaluating of clinical studies. We encourage the prospective user to modify the checklists according to the respective application and research question. The higher expenditure needed for the evaluation of clinical studies in systematic reviews is justified, particularly in the light of the influential nature of their conclusions on therapeutic decisions and the creation of clinical guidelines.

  11. SET-bullying: presentation of a collaborative project and discussion of its internal and external validity.

    Science.gov (United States)

    Chalamandaris, Alexandros-Georgios; Wilmet-Dramaix, Michèle; Eslea, Mike; Ertesvåg, Sigrun Karin; Piette, Danielle

    2016-04-12

    Since the early 1980s, several school based anti-bullying interventions (SBABI) have been implemented and evaluated in different countries. Some meta-analyses have also drawn conclusions on the effectiveness of SBABIs. However, the relationship between time and effectiveness of SBABIs has not been fully studied. For this aim, a collaborative project, SET-Bullying, is established by researchers from Greece, Belgium, Norway and United Kingdom. Its primary objective is to further understand and statistically model the relationship between the time and the sustainability of the effectiveness of SBABI. The secondary objective of SET-Bullying is to assess the possibility of predicting the medium-term or long-term effectiveness using as key information the prior measurement and the short-term effectiveness of the intervention. Researchers and owners of potentially eligible databases were asked to participate in this effort. Two studies have contributed data for the purpose of SET-Bullying. This paper summarizes the main characteristics of the participating studies and provides a high level overview of the collaborative project. It also discusses on the extent to which both study and project characteristics may pose threats to the expected internal and external validity of the potential outcomes of the project. Despite these threats, this work represents the first effort to understand the impact of time on the observed effectiveness of SBABIs and assess its predictability, which would allow for better planning, implementation and evaluation of SBABIs.

  12. External validation of clinical decision rules for children with wrist trauma.

    Science.gov (United States)

    Mulders, Marjolein A M; Walenkamp, Monique M J; Dubois, Bente F H; Slaar, Annelie; Goslings, J Carel; Schep, Niels W L

    2017-05-01

    Clinical decision rules help to avoid potentially unnecessary radiographs of the wrist, reduce waiting times and save costs. The primary aim of this study was to provide an overview of all existing non-validated clinical decision rules for wrist trauma in children and to externally validate these rules in a different cohort of patients. Secondarily, we aimed to compare the performance of these rules with the validated Amsterdam Pediatric Wrist Rules. We included all studies that proposed a clinical prediction or decision rule in children presenting at the emergency department with acute wrist trauma. We performed external validation within a cohort of 379 children. We also calculated the sensitivity, specificity, negative predictive value and positive predictive value of each decision rule. We included three clinical decision rules. The sensitivity and specificity of all clinical decision rules after external validation were between 94% and 99%, and 11% and 26%, respectively. After external validation 7% to 17% less radiographs would be ordered and 1.4% to 5.7% of all fractures would be missed. Compared to the Amsterdam Pediatric Wrist Rules only one of the three other rules had a higher sensitivity; however both the specificity and the reduction in requested radiographs were lower in the other three rules. The sensitivity of the three non-validated clinical decision rules is high. However the specificity and the reduction in number of requested radiographs are low. In contrast, the validated Amsterdam Pediatric Wrist Rules has an acceptable sensitivity and the greatest reduction in radiographs, at 22%, without missing any clinically relevant fractures.

  13. Understanding Foreign Language Learning Strategies: A Validation Study

    Science.gov (United States)

    Tragant, Elsa; Thompson, Marilyn S.; Victori, Mia

    2013-01-01

    The present work aims to contribute to our understanding of the underlying dimensions of language learning strategies in foreign language contexts. The study analyzes alternative factor structures underlying a recently developed instrument (Tragant and Victori, 2012) and it includes the age factor in the examination of its construct validity. The…

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

    Science.gov (United States)

    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…

  15. Systematic Review and the External Validity of Randomized Controlled Trials in Lupus Nephritis

    Directory of Open Access Journals (Sweden)

    Angela Pakozdi

    2018-03-01

    Conclusion: Published RCTs do not truly reflect the heterogeneity of patients with LN in routine practice at our lupus center. The external validity of RCTs could be improved by including more representative patient cohorts. RCTs should be used as a guide but consideration should be given to similarities between individual patients and the characteristics of the trial cohorts before treatment decisions being made.

  16. Real-life COPD patients compared to large trial populations : An UNLOCK external validity study

    NARCIS (Netherlands)

    Kruis, Annemarije; Ställberg, Bjorn; Jones, Rupert; Tsiligianni, Ioanna; Kocks, Jan Willem; Van Der Molen, Thys; Chavannes, Niels

    2013-01-01

    Objective To investigate the external validity of six large randomized controlled medication trials (ISOLDE, TRISTAN, TORCH, UPLIFT, ECLIPSE, POET-COPD) compared to the COPD population seen in the community, and to examine the proportion of patients in the community that would be selected based on

  17. 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 models...... for prediction of pneumonia in primary care were externally validated in the individual patient data (IPD) of previously performed diagnostic studies. METHODS AND FINDINGS: S&S models for diagnosing pneumonia in adults presenting to primary care with lower respiratory tract infection and IPD for validation were...... identified through a systematical search. Six prediction models and IPD of eight diagnostic studies (N total = 5308, prevalence pneumonia 12%) were included. Models were assessed on discrimination and calibration. Discrimination was measured using the pooled Area Under the Curve (AUC) and delta AUC...

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

    Science.gov (United States)

    Rahman, M Shafiqur; Ambler, Gareth; Choodari-Oskooei, Babak; Omar, Rumana Z

    2017-04-18

    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. 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. 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. 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 accuracy curves. In addition, we recommend to investigate the characteristics

  19. The challenge of external validity in policy-relevant systematic reviews: a case study from the field of substance misuse.

    Science.gov (United States)

    Pearson, Mark; Coomber, Ross

    2010-01-01

    To critically evaluate the methods utilized in the conduct of a systematic review in the field of substance misuse. Participant-observation in the review process, semi-structured interviews with review team members and management and structured observation of the process of guidance development. An 'arm's-length' government body. Review team members, management and the committee responsible for producing evidence-based guidance for policy and practice. Data from interviews and (participant-)observation were reflected upon critically in order to increase understanding of the systematic review process. The application of systematic review methods produced an evidence base that did not inform the development of guidance to the extent that it could have done: (i) an emphasis upon internal research validity produced an evidence base with an emphasis on short-term interventions at the level of the individual; (ii) criteria for appraising the external validity of studies were not developed sufficiently; and (iii) the systematic review of evidence and development of guidance are strongly reliant upon the judgement of reviewers and committee members. Prioritizing internal validity in a systematic review risks producing an evidence base that is not informed adequately by the wider determinants of health and which does not give sufficient consideration to external validity. The use of appropriate methods requires that commissioners of systematic reviews are clear at the outset how the review is proposed to be utilized. Review methods such as meta-ethnography and realist synthesis could contribute to making the frameworks within which judgements are made more explicit.

  20. Prognostic models for locally advanced cervical cancer: external validation of the published models.

    Science.gov (United States)

    Lora, David; Gómez de la Cámara, Agustín; Fernández, Sara Pedraza; Enríquez de Salamanca, Rafael; Gómez, José Fermín Pérez Regadera

    2017-09-01

    To externally validate the prognostic models for predicting the time-dependent outcome in patients with locally advanced cervical cancer (LACC) who were treated with concurrent chemoradiotherapy in an independent cohort. A historical cohort of 297 women with LACC who were treated with radical concurrent chemoradiotherapy from 1999 to 2014 at the 12 de Octubre University Hospital (H12O), Madrid, Spain. The external validity of prognostic models was quantified regarding discrimination, calibration, measures of overall performance, and decision curve analyses. The review identified 8 studies containing 13 prognostic models. Different (International Federation of Gynecology and Obstetrics [FIGO] stages, parametrium involvement, hydronephrosis, location of positive nodes, and race) but related cohorts with validation cohort (5-year overall survival [OS]=70%; 5-year disease-free survival [DFS]=64%; average age of 50; and over 79% squamous cell) were evaluated. The following models exhibited good external validity in terms of discrimination and calibration but limited clinical utility: the OS model at 3 year from Kidd et al.'s study (area under the receiver operating characteristic curve [AUROC]=0.69; threshold of clinical utility [TCU] between 36% and 50%), the models of DFS at 1 year from Kidd et al.'s study (AUROC=0.64; TCU between 24% and 32%) and 2 years from Rose et al.'s study (AUROC=0.70; TCU between 19% and 58%) and the distant recurrence model at 5 years from Kang et al.'s study (AUROC=0.67; TCU between 12% and 36%). The external validation revealed the statistical and clinical usefulness of 4 prognostic models published in the literature. Copyright © 2017. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology

  1. Regression Discontinuity and Beyond: Options for Studying External Validity in an Internally Valid Design

    Science.gov (United States)

    Wing, Coady; Bello-Gomez, Ricardo A.

    2018-01-01

    Treatment effect estimates from a "regression discontinuity design" (RDD) have high internal validity. However, the arguments that support the design apply to a subpopulation that is narrower and usually different from the population of substantive interest in evaluation research. The disconnect between RDD population and the…

  2. External validation of multivariable prediction models: a systematic review of methodological conduct and reporting

    Science.gov (United States)

    2014-01-01

    Background Before considering whether to use a multivariable (diagnostic or prognostic) prediction model, it is essential that its performance be evaluated in data that were not used to develop the model (referred to as external validation). We critically appraised the methodological conduct and reporting of external validation studies of multivariable prediction models. Methods We conducted a systematic review of articles describing some form of external validation of one or more multivariable prediction models indexed in PubMed core clinical journals published in 2010. Study data were extracted in duplicate on design, sample size, handling of missing data, reference to the original study developing the prediction models and predictive performance measures. Results 11,826 articles were identified and 78 were included for full review, which described the evaluation of 120 prediction models. in participant data that were not used to develop the model. Thirty-three articles described both the development of a prediction model and an evaluation of its performance on a separate dataset, and 45 articles described only the evaluation of an existing published prediction model on another dataset. Fifty-seven percent of the prediction models were presented and evaluated as simplified scoring systems. Sixteen percent of articles failed to report the number of outcome events in the validation datasets. Fifty-four percent of studies made no explicit mention of missing data. Sixty-seven percent did not report evaluating model calibration whilst most studies evaluated model discrimination. It was often unclear whether the reported performance measures were for the full regression model or for the simplified models. Conclusions The vast majority of studies describing some form of external validation of a multivariable prediction model were poorly reported with key details frequently not presented. The validation studies were characterised by poor design, inappropriate handling

  3. Large-scale external validation and comparison of prognostic models: an application to chronic obstructive pulmonary disease

    NARCIS (Netherlands)

    Guerra, Beniamino; Haile, Sarah R.; Lamprecht, Bernd; Ramírez, Ana S.; Martinez-Camblor, Pablo; Kaiser, Bernhard; Alfageme, Inmaculada; Almagro, Pere; Casanova, Ciro; Esteban-González, Cristóbal; Soler-Cataluña, Juan J.; de-Torres, Juan P.; Miravitlles, Marc; Celli, Bartolome R.; Marin, Jose M.; ter Riet, Gerben; Sobradillo, Patricia; Lange, Peter; Garcia-Aymerich, Judith; Antó, Josep M.; Turner, Alice M.; Han, MeiLan K.; Langhammer, Arnulf; Leivseth, Linda; Bakke, Per; Johannessen, Ane; Oga, Toru; Cosio, Borja; Ancochea-Bermúdez, Julio; Echazarreta, Andres; Roche, Nicolas; Burgel, Pierre-Régis; Sin, Don D.; Soriano, Joan B.; Puhan, Milo A.

    2018-01-01

    External validations and comparisons of prognostic models or scores are a prerequisite for their use in routine clinical care but are lacking in most medical fields including chronic obstructive pulmonary disease (COPD). Our aim was to externally validate and concurrently compare prognostic scores

  4. Statistical external validation and consensus modeling: a QSPR case study for Koc prediction.

    Science.gov (United States)

    Gramatica, Paola; Giani, Elisa; Papa, Ester

    2007-03-01

    The soil sorption partition coefficient (log K(oc)) of a heterogeneous set of 643 organic non-ionic compounds, with a range of more than 6 log units, is predicted by a statistically validated QSAR modeling approach. The applied multiple linear regression (ordinary least squares, OLS) is based on a variety of theoretical molecular descriptors selected by the genetic algorithms-variable subset selection (GA-VSS) procedure. The models were validated for predictivity by different internal and external validation approaches. For external validation we applied self organizing maps (SOM) to split the original data set: the best four-dimensional model, developed on a reduced training set of 93 chemicals, has a predictivity of 78% when applied on 550 validation chemicals (prediction set). The selected molecular descriptors, which could be interpreted through their mechanistic meaning, were compared with the more common physico-chemical descriptors log K(ow) and log S(w). The chemical applicability domain of each model was verified by the leverage approach in order to propose only reliable data. The best predicted data were obtained by consensus modeling from 10 different models in the genetic algorithm model population.

  5. Are external quality assurance (EQA) slide schemes a valid tool for the performance assessment of histopathologists?

    Science.gov (United States)

    Parham, D M

    2005-01-01

    Quality assurance plays a vital role in the healthcare profession and histopathologists play a central role in the diagnosis and treatment of disease. In the past these specialists have worked in isolation and quality assurance of their work has been difficult. In recent years this has changed with the introduction of External Quality Assurance slide schemes. This paper discusses how these schemes have evolved, the problems of standard setting and their validity as a measure of pathologists performance.

  6. External validity of a generic safety climate scale for lone workers across different industries and companies.

    Science.gov (United States)

    Lee, Jin; Huang, Yueng-hsiang; Robertson, Michelle M; Murphy, Lauren A; Garabet, Angela; Chang, Wen-Ruey

    2014-02-01

    The goal of this study was to examine the external validity of a 12-item generic safety climate scale for lone workers in order to evaluate the appropriateness of generalized use of the scale in the measurement of safety climate across various lone work settings. External validity evidence was established by investigating the measurement equivalence (ME) across different industries and companies. Confirmatory factor analysis (CFA)-based and item response theory (IRT)-based perspectives were adopted to examine the ME of the generic safety climate scale for lone workers across 11 companies from the trucking, electrical utility, and cable television industries. Fairly strong evidence of ME was observed for both organization- and group-level generic safety climate sub-scales. Although significant invariance was observed in the item intercepts across the different lone work settings, absolute model fit indices remained satisfactory in the most robust step of CFA-based ME testing. IRT-based ME testing identified only one differentially functioning item from the organization-level generic safety climate sub-scale, but its impact was minimal and strong ME was supported. The generic safety climate scale for lone workers reported good external validity and supported the presence of a common feature of safety climate among lone workers. The scale can be used as an effective safety evaluation tool in various lone work situations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Achieving external validity in home advantage research: generalizing crowd noise effects

    Directory of Open Access Journals (Sweden)

    Tony D Myers

    2014-06-01

    Full Text Available Different factors have been postulated to explain the home advantage phenomenon in sport. One plausible explanation investigated has been the influence of a partisan home crowd on sports officials’ decisions. Different types of studies have tested the crowd influence hypothesis including purposefully designed experiments. However, while experimental studies investigating crowd influences have high levels of internal validity, they suffer from a lack of external validity; decision-making in a laboratory setting bearing little resemblance to decision-making in live sports settings. This focused review initially considers threats to external validity in applied and theoretical experimental research. Discussing how such threats can be addressed using representative design by focusing on a recently published study that arguably provides the first experimental evidence of the impact of live crowd noise on officials in sport. The findings of this controlled experiment conducted in a real tournament setting offer some confirmation of the validity of laboratory experimental studies in the area. Finally directions for future research and the future conduct of crowd noise studies are discussed.

  8. Reliability and External Validity of AMSTAR in Assessing Quality of TCM Systematic Reviews.

    Science.gov (United States)

    Kang, Deying; Wu, Yuxia; Hu, Dan; Hong, Qi; Wang, Jialiang; Zhang, Xin

    2012-01-01

    Objective. The aim of this study is to measure the reliability and external validity of AMSTAR by applying it to a sample of TCM systematic reviews. Study Design and Methods. We tested the agreement, reliability, construct validity, and feasibility of AMSTAR through comparisons with OQAQ. Statistical analyses were performed by using SPSS 13.0. Results. A random of sample with 41 TCM systematic reviews was selected from a database. The interrater agreement of the individual items of AMSTAR was moderate with a mean kappa of 0.50 (95% CI: 0.26, 0.73). The ICC for AMSTAR against OQAQ (total score of 9 items, excluding item 10) was 0.87 (95% CI: 0.76, 0.93). Conclusions. Although there is room for improvement on few items, the new tool is reliable, valid, and easy to use for methodological quality assessment of systematic reviews on TCM.

  9. Reliability and External Validity of AMSTAR in Assessing Quality of TCM Systematic Reviews

    Directory of Open Access Journals (Sweden)

    Deying Kang

    2012-01-01

    Full Text Available Objective. The aim of this study is to measure the reliability and external validity of AMSTAR by applying it to a sample of TCM systematic reviews. Study Design and Methods. We tested the agreement, reliability, construct validity, and feasibility of AMSTAR through comparisons with OQAQ. Statistical analyses were performed by using SPSS 13.0. Results. A random of sample with 41 TCM systematic reviews was selected from a database. The interrater agreement of the individual items of AMSTAR was moderate with a mean kappa of 0.50 (95% CI: 0.26, 0.73. The ICC for AMSTAR against OQAQ (total score of 9 items, excluding item 10 was 0.87 (95% CI: 0.76, 0.93. Conclusions. Although there is room for improvement on few items, the new tool is reliable, valid, and easy to use for methodological quality assessment of systematic reviews on TCM.

  10. Multicentre validation of IMRT pre-treatment verification: comparison of in-house and external audit.

    Science.gov (United States)

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

    2014-09-01

    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. 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. 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. 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. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  12. Achieving external validity in home advantage research: generalizing crowd noise effects.

    Science.gov (United States)

    Myers, Tony D

    2014-01-01

    Different factors have been postulated to explain the home advantage phenomenon in sport. One plausible explanation investigated has been the influence of a partisan home crowd on sports officials' decisions. Different types of studies have tested the crowd influence hypothesis including purposefully designed experiments. However, while experimental studies investigating crowd influences have high levels of internal validity, they suffer from a lack of external validity; decision-making in a laboratory setting bearing little resemblance to decision-making in live sports settings. This focused review initially considers threats to external validity in applied and theoretical experimental research. Discussing how such threats can be addressed using representative design by focusing on a recently published study that arguably provides the first experimental evidence of the impact of live crowd noise on officials in sport. The findings of this controlled experiment conducted in a real tournament setting offer a level of confirmation of the findings of laboratory studies in the area. Finally directions for future research and the future conduct of crowd noise studies are discussed.

  13. Clinical drug trials in general practice: how well are external validity issues reported?

    Science.gov (United States)

    Brænd, Anja Maria; Straand, Jørund; Klovning, Atle

    2017-12-29

    When reading a report of a clinical trial, it should be possible to judge whether the results are relevant for your patients. Issues affecting the external validity or generalizability of a trial should therefore be reported. Our aim was to determine whether articles with published results from a complete cohort of drug trials conducted entirely or partly in general practice reported sufficient information about the trials to consider the external validity. A cohort of 196 drug trials in Norwegian general practice was previously identified from the Norwegian Medicines Agency archive with year of application for approval 1998-2007. After comprehensive literature searches, 134 journal articles reporting results published from 2000 to 2015 were identified. In these articles, we considered the reporting of the following issues relevant for external validity: reporting of the clinical setting; selection of patients before inclusion in a trial; reporting of patients' co-morbidity, co-medication or ethnicity; choice of primary outcome; and reporting of adverse events. Of these 134 articles, only 30 (22%) reported the clinical setting of the trial. The number of patients screened before enrolment was reported in 61 articles (46%). The primary outcome of the trial was a surrogate outcome for 60 trials (45%), a clinical outcome for 39 (29%) and a patient-reported outcome for 25 (19%). Clinical details of adverse events were reported in 124 (93%) articles. Co-morbidity of included participants was reported in 54 trials (40%), co-medication in 27 (20%) and race/ethnicity in 78 (58%). The clinical setting of the trials, the selection of patients before enrolment, and co-morbidity or co-medication of participants was most commonly not reported, limiting the possibility to consider the generalizability of a trial. It may therefore be difficult for readers to judge whether drug trial results are applicable to clinical decision-making in general practice or when developing clinical

  14. The predictive validity of the DEBQ-external eating scale for eating in response to food commercials while watching television

    NARCIS (Netherlands)

    van Strien, Tatjana; Peter Herman, C; Anschutz, Doeschka

    OBJECTIVE: To challenge the conclusion by Jansen et al., Int J Eat Disord 2011; 44:164-168, that the widely used Dutch Eating Behavior Questionnaire (DEBQ) External Eating subscale (DEBQ-EX) lacks validity for external eating, because of limitations of that study. METHOD: In a seminaturalistic

  15. The Predictive Validity of the DEBQ-External Eating Scale For Eating in Response to Food Commercials While Watching Television

    NARCIS (Netherlands)

    Strien, T. van; Herman, C.P.; Anschutz, D.J.

    2012-01-01

    Objective: To challenge the conclusion by Jansen et al., Int J Eat Disord 2011; 44:164-168, that the widely used Dutch Eating Behavior Questionnaire (DEBQ) External Eating subscale (DEBQ-EX) lacks validity for external eating, because of limitations of that study. Method: In a seminaturalistic

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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 < .001). We created a 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

  19. 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.

  20. 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...... with a goodness-of-fit test of X2=5.37 (7 degrees of freedom), p=0.62. CONCLUSION: LDT-EWS has acceptable ability to identify patients at high risk of dying during hospitalization with good precision. Further studies performing impact analysis are required before this score should be implemented in clinical...

  1. A multi-institutional external validation of the fistula risk score for pancreatoduodenectomy.

    Science.gov (United States)

    Miller, Benjamin C; Christein, John D; Behrman, Stephen W; Drebin, Jeffrey A; Pratt, Wande B; Callery, Mark P; Vollmer, Charles M

    2014-01-01

    The Fistula Risk Score (FRS), a ten-point scale that relies on weighted influence of four variables, has been shown to effectively predict clinically relevant postoperative pancreatic fistula (CR-POPF) development and its consequences after pancreatoduodenectomy (PD). The proposed FRS demonstrated excellent predictive capacity; however, external validation of this tool would confirm its universal applicability. From 2001 to 2012, 594 PDs with pancreatojejunostomy reconstructions were performed at three institutions. POPFs were graded by International Study Group on Pancreatic Fistula standards as grades A, B, or C. The FRS was calculated for each patient, and clinical outcomes were evaluated across four discrete risk zones as described in the original work. Receiver operator curve analysis was performed to judge model validity. One hundred forty-two patients developed any sort of POPF, of which 68 were CR-POPF (11.4 % overall; 8.9 % grade B, 2.5 % grade C). Increasing FRS scores (0-10) correlated well with CR-POPF development (p < 0.001) with a C-statistic of 0.716. When segregated by discrete FRS-risk groups, CR-POPFs occurred in low-, moderate-, and high-risk patients, 6.6, 12.9, and 28.6 % of the time, respectively (p < 0.001). Clinical outcomes including complications, length of stay, and readmission rates also increased across risk groups. This multi-institutional experience confirms the Fistula Risk Score as a valid tool for predicting the development of CR-POPF after PD. Patients devoid of any risk factors did not develop a CR-POPF, and the rate of CR-POPF approximately doubles with each subsequent risk zone. The FRS is validated as a strongly predictive tool, with widespread applicability, which can be readily incorporated into common clinical practice and research analysis.

  2. External validity of children's self-reported sleep functioning: associations with academic, social, and behavioral adjustment.

    Science.gov (United States)

    Becker, Stephen P

    2014-09-01

    Several child-report measures of sleep functioning have been developed but very few studies have examined the external validity of child self-reported sleep in relation to daytime functioning. This study examined child-reported sleep in relation to teacher-rated psychopathology symptoms and also tested the hypothesis that child-reported sleep would be associated with poorer child- and teacher-reported functioning after controlling for demographics and psychopathology symptoms that are known to be associated with adjustment. Participants were 175 children (81 boys, 94 girls) in 1st-6th grades (ages 6-13) and their teachers. Children completed the Sleep Self-Report. Teachers completed a measure of attention-deficit/hyperactivity disorder (ADHD), oppositional/conduct, and anxiety/depression symptoms. Children and teachers completed multiple measures of academic, behavioral, and social/peer functioning. Child-reported sleep was significantly associated with teacher-rated inattentive and internalizing symptoms, even after controlling for child demographics, hyperactivity-impulsivity, and conduct problems. Multilevel modeling analyses further indicated that, after controlling for child demographics and psychopathology symptoms, child-reported sleep problems were significantly associated with poorer child- and teacher-reported academic, behavioral, and social functioning (including increased reactive aggression, peer rejection, loneliness, and lower friendship satisfaction and self-worth). Findings provide initial support for the external validity of children's self-reported sleep functioning. Results of this study suggest that it may be clinically useful to screen for sleep problems by assessing for children's own perceptions of their sleep. Future studies should include both child- and parent-reported sleep functioning to further examine the utility of children's ratings of sleep functioning. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. How to Assess the External Validity and Model Validity of Therapeutic Trials: A Conceptual Approach to Systematic Review Methodology

    Science.gov (United States)

    2014-01-01

    Background. Evidence rankings do not consider equally internal (IV), external (EV), and model validity (MV) for clinical studies including complementary and alternative medicine/integrative medicine (CAM/IM) 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/IM 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. PMID:24734111

  4. External validation of medicare claims for breast cancer chemotherapy compared with medical chart reviews.

    Science.gov (United States)

    Du, Xianglin L; Key, Charles R; Dickie, Lois; Darling, Ronald; Geraci, Jane M; Zhang, Dong

    2006-02-01

    Although Medicare claims data have been increasingly used to examine the patterns and outcomes of cancer chemotherapy, their external validity has not been well studied. We sought to validate Medicare claims for chemotherapy compared with medical chart reviews. We completed medical chart reviews for 1228 women who were diagnosed with breast cancer at age 65 and older between 1993 and 1999 in New Mexico that were linked with Medicare claims data, achieving an estimated sensitivity of more than 90% and a 0.05 level of precision. Of the 150 subjects identified by Medicare claims as receiving chemotherapy within 6 months of diagnosis, 75% were confirmed by medical records as having received chemotherapy. Of the remaining 25% of cases without chart verification, (1) 33 cases had 7 or more claims for chemotherapy and also had specific chemotherapy drugs indicated in Medicare data, representing 22% (33/150) of all cases that received chemotherapy according to Medicare claims and (2) 4 cases had 1 to 6 claims for chemotherapy, representing 3% (4/150) of all cases with claims for chemotherapy. Of those 1078 subjects who did not receive chemotherapy according to Medicare claims, more than 99% were confirmed by chart reviews. Observed agreement on chemotherapy between Medicare claims and chart reviews was 94% and overall reliability (kappa) was 0.69 (95% confidence interval = 0.63-0.76). Of cases identified as receiving chemotherapy by Medicare claims, 97% had strong evidence and only 3% had weak evidence for receiving this therapy.

  5. A latent class approach to the external validation of respiratory and non-respiratory panic subtypes

    Science.gov (United States)

    Roberson-Nay, R.; Latendresse, S. J.; Kendler, K. S.

    2013-01-01

    Background The phenotypic variance observed in panic disorder (PD) appears to be best captured by a respiratory and non-respiratory panic subtype. We compared respiratory and non-respiratory panic subtypes across a series of external validators (temporal stability, psychiatric co-morbidity, treatment response) to determine whether subtypes are best conceptualized as differing: (1) only on their symptom profiles with no other differences between them; (2) on a quantitative (i.e. severity) dimension only; or (3) qualitatively from one another. Method Data from a large epidemiological survey (National Epidemiologic Survey on Alcohol and Related Conditions) and a clinical trial (Cross-National Collaborative Panic Study) were used. All analytic comparisons were examined within a latent class framework. Results High temporal stability of panic subtypes was observed, particularly among females. Respiratory panic was associated with greater odds of lifetime major depression and a range of anxiety disorders as well as increased treatment utilization, but no demographic differences. Treatment outcome data did not suggest that the two PD subtypes were associated with differential response to either imipramine or alprazolam. Conclusions These data suggest that respiratory and non-respiratory panic represent valid subtypes along the PD continuum, with the respiratory variant representing a more severe form of the disorder. PMID:21846423

  6. External validation of a prognostic model for predicting survival of cirrhotic patients with refractory ascites.

    Science.gov (United States)

    Guardiola, Jordi; Baliellas, Carme; Xiol, Xavier; Fernandez Esparrach, Glòria; Ginès, Pere; Ventura, Pere; Vazquez, Santiago

    2002-09-01

    Cirrhotic patients with refractory ascites (RA) have a poor prognosis, although individual survival varies greatly. A model that could predict survival for patients with RA would be helpful in planning treatment. Moreover, in cases of potential liver transplantation, a model of these characteristics would provide the bases for establishing priorities of organ allocation and the selection of patients for a living donor graft. Recently, we developed a model to predict survival of patients with RA. The aim of this study was to establish its generalizability for predicting the survival of patients with RA. The model was validated by assessing its performance in an external cohort of patients with RA included in a multicenter, randomized, controlled trial that compared large-volume paracentesis and peritoneovenous shunt. The values for actual and model-predicted survival of three risk groups of patients, established according to the model, were compared graphically and by means of the one-sample log-rank test. The model provided a very good fit to the survival data of the three risk groups in the validation cohort. We also found good agreement between the survival predicted from the model and the observed survival when patients treated with peritoneovenous shunt and with paracentesis were considered separately. Our survival model can be used to predict the survival of patients with RA and may be a useful tool in clinical decision making, especially in deciding priority for liver transplantation.

  7. Validity of the Externalizing Spectrum Inventory in a Criminal Offender Sample: Relations with Disinhibitory Psychopathology, Personality, and Psychopathic Features

    Science.gov (United States)

    Venables, Noah C.; Patrick, Christopher J.

    2013-01-01

    The Externalizing Spectrum Inventory (ESI; Krueger, Markon, Patrick, Benning, & Kramer, 2007) provides a self-report based method for indexing a range of correlated problem behaviors and traits in the domain of deficient impulse control. The ESI organizes lower-order behaviors and traits of this kind around higher-order factors encompassing general disinhibitory proneness, callous-aggression, and substance abuse. The current study used data from a male prisoner sample (N = 235) to evaluate the validity of ESI total and factor scores in relation to external criterion measures consisting of externalizing disorder symptoms (including child and adult antisocial deviance and substance-related problems) assessed via diagnostic interview, personality traits assessed by self-report, and psychopathic features as assessed by both interview and self-report. Results provide evidence for the validity of the ESI measurement model and point to its potential utility as a referent for research on the neurobiological correlates and etiological bases of externalizing proneness. PMID:21787091

  8. External validation of a prognostic nomogram for overall survival in women with uterine leiomyosarcoma.

    Science.gov (United States)

    Iasonos, Alexia; Keung, Emily Z; Zivanovic, Oliver; Mancari, Rosanna; Peiretti, Michele; Nucci, Marisa; George, Suzanne; Colombo, Nicoletta; Carinelli, Silvestro; Hensley, Martee L; Raut, Chandrajit P

    2013-05-15

    There is no validated system to identify prognostically distinct cohorts of women with uterine leiomyosarcoma (ULMS). By using an independent, pooled, multi-institutional, international patient cohort, the authors validated a recently proposed ULMS nomogram. The ULMS nomogram incorporated 7 clinical characteristics (age, tumor size, tumor grade, cervical involvement, locoregional metastases, distant metastases, and mitotic index (per 10 high-power fields) to predict overall survival (OS) after primary surgery. Independent cohorts from 2 sarcoma centers were included. Eligible women, at minimum, underwent a hysterectomy for primary, locally advanced, or metastatic ULMS and received part of their care at 1 of the centers between 1994 and 2010. In total, 187 women with ULMS were identified who met the above criteria described above (median age, 51 years; median tumor size, 9 cm; median mitotic index, 20 per 10 high-power fields). Tumors generally were high grade (88%), FIGO stage I or II (61%) without cervical involvement (93%) and without locoregional metastases (77%) or distant metastases (83%). The median OS and the 5-year OS rate were 4.5 years (95% confidence interval, 3.2-5.3 years) and 46%, respectively; and 65 women (35%) remained alive at last follow-up. The nomogram concordance index was 0.67(standard error, 0.02), which was as high as the concordance index from the initial cohort used for nomogram development. The concordance between actual OS and nomogram predictions suggests excellent calibration because predictions were within 1% of actual 5-year OS rates for patients with a predicted 5-year OS of less than 0.68. The ULMS nomogram was externally validated using independent cohorts. These findings support the international use of the ULMS nomogram prognostic of OS in ULMS. Copyright © 2013 American Cancer Society.

  9. Mission Driven Scene Understanding: Candidate Model Training and Validation

    Science.gov (United States)

    2016-09-01

    CNN was able to determine the correct class labels for images taken from the 2,560 image training data set, the validation process did not appear to...set containing approximately 1.2 million images (Fig. 1). In Section 3, we show that the CNN achieved 79.7% validation accuracy for the top-5 class...to their capability to incorporate different types of CNN architectures, their hardware usage (central processing unit [CPU] and graphical

  10. Prediction models for the mortality risk in chronic dialysis patients: a systematic review and independent external validation study.

    Science.gov (United States)

    Ramspek, Chava L; Voskamp, Pauline Wm; van Ittersum, Frans J; Krediet, Raymond T; Dekker, Friedo W; van Diepen, Merel

    2017-01-01

    In medicine, many more prediction models have been developed than are implemented or used in clinical practice. These models cannot be recommended for clinical use before external validity is established. Though various models to predict mortality in dialysis patients have been published, very few have been validated and none are used in routine clinical practice. The aim of the current study was to identify existing models for predicting mortality in dialysis patients through a review and subsequently to externally validate these models in the same large independent patient cohort, in order to assess and compare their predictive capacities. A systematic review was performed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. To account for missing data, multiple imputation was performed. The original prediction formulae were extracted from selected studies. The probability of death per model was calculated for each individual within the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD). The predictive performance of the models was assessed based on their discrimination and calibration. In total, 16 articles were included in the systematic review. External validation was performed in 1,943 dialysis patients from NECOSAD for a total of seven models. The models performed moderately to well in terms of discrimination, with C -statistics ranging from 0.710 (interquartile range 0.708-0.711) to 0.752 (interquartile range 0.750-0.753) for a time frame of 1 year. According to the calibration, most models overestimated the probability of death. Overall, the performance of the models was poorer in the external validation than in the original population, affirming the importance of external validation. Floege et al's models showed the highest predictive performance. The present study is a step forward in the use of a prediction model as a useful tool for nephrologists, using evidence-based medicine that

  11. Prediction of violent reoffending on release from prison: derivation and external validation of a scalable tool.

    Science.gov (United States)

    Fazel, Seena; Chang, Zheng; Fanshawe, Thomas; Långström, Niklas; Lichtenstein, Paul; Larsson, Henrik; Mallett, Susan

    2016-06-01

    More than 30 million people are released from prison worldwide every year, who include a group at high risk of perpetrating interpersonal violence. Because there is considerable inconsistency and inefficiency in identifying those who would benefit from interventions to reduce this risk, we developed and validated a clinical prediction rule to determine the risk of violent offending in released prisoners. We did a cohort study of a population of released prisoners in Sweden. Through linkage of population-based registers, we developed predictive models for violent reoffending for the cohort. First, we developed a derivation model to determine the strength of prespecified, routinely obtained criminal history, sociodemographic, and clinical risk factors using multivariable Cox proportional hazard regression, and then tested them in an external validation. We measured discrimination and calibration for prediction of our primary outcome of violent reoffending at 1 and 2 years using cutoffs of 10% for 1-year risk and 20% for 2-year risk. We identified a cohort of 47 326 prisoners released in Sweden between 2001 and 2009, with 11 263 incidents of violent reoffending during this period. We developed a 14-item derivation model to predict violent reoffending and tested it in an external validation (assigning 37 100 individuals to the derivation sample and 10 226 to the validation sample). The model showed good measures of discrimination (Harrell's c-index 0·74) and calibration. For risk of violent reoffending at 1 year, sensitivity was 76% (95% CI 73-79) and specificity was 61% (95% CI 60-62). Positive and negative predictive values were 21% (95% CI 19-22) and 95% (95% CI 94-96), respectively. At 2 years, sensitivity was 67% (95% CI 64-69) and specificity was 70% (95% CI 69-72). Positive and negative predictive values were 37% (95% CI 35-39) and 89% (95% CI 88-90), respectively. Of individuals with a predicted risk of violent reoffending of 50% or more, 88% had drug

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

    Science.gov (United States)

    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…

  13. 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.

  14. Ecological Validity in Understanding Sport Performance: Some Problems of Definition.

    Science.gov (United States)

    Davids, Keith

    1988-01-01

    The article attempts to identify and define some of the most important criteria underpinning ecologically valid research in sport psychology. Vision and sport performance is used as an exemplary area for examination of issues. It is concluded that more debate must be stimulated concerning this important methodological principle. (Author/CB)

  15. External validation suggests Integrin beta 3 as prognostic biomarker in serous ovarian adenocarcinomas

    Directory of Open Access Journals (Sweden)

    Sundfeldt Karin

    2009-09-01

    Full Text Available Abstract Background The majority of women with ovarian cancer are diagnosed in late stages, and the mortality rate is high. The use of biomarkers as prognostic factors may improve the treatment and clinical outcome of these patients. We performed an external validation of the potential biomarkers CLU, ITGB3, CAPG, and PRAME to determine if the expression levels are relevant to use as prognostic factors. Methods We analysed the gene expression of CLU, ITGB3, CAPG, and PRAME in 30 advanced staged serous adenocarcinomas with quantitative real-time polymerase chain reaction (QPCR and the protein levels were analysed in 98 serous adenocarcinomas with western blot for semiquantitative analysis. Statistical differences in mRNA and protein expressions between tumours from survivors and tumours from deceased patients were evaluated using the Mann-Whitney U test. Results The gene and protein ITGB3 (Integrin beta 3 were significantly more expressed in tumours from survivors compared to tumours from deceased patients, which is in concordance with our previous results. However, no significant differences were detected for the other three genes or proteins CLU, CAPG, and PRAME. Conclusion The loss of ITGB3 expression in tumours from deceased patients and high expression in tumours from survivors could be used as a biomarker for patients with advanced serous tumours.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  17. 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

  18. Validation of a Switching Operation in the External Grid of Gunfleet Sand Offshore Wind Farm by Means of EMT Simulations

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Okholm, J.; Holbøll, Joachim

    2011-01-01

    This paper presents the voltage signals occurring during a switching operation recorded in the external grid of Gunfleet Sands Offshore Wind Farm recorded with an Elspec measurement system. The measurements are compared to electromagnetic (EMT) simulations for validation of the wind farm model us...

  19. A Validation of the Student Risk Screening Scale for Internalizing and Externalizing Behaviors: Patterns in Rural and Urban Elementary Schools

    Science.gov (United States)

    Lane, Kathleen Lynne; Menzies, Holly M.; Oakes, Wendy P.; Lambert, Warren; Cox, Meredith; Hankins, Katy

    2012-01-01

    We report findings of two studies, one conducted in a rural school district (N = 982) and a second conducted in an urban district (N = 1,079), offering additional evidence of the reliability and validity of a revised instrument, the Student Risk Screening Scale-Internalizing and Externalizing (SRSS-IE), to accurately detect internalizing and…

  20. Understanding and Using Feedback--A Review of Empirical Studies Concerning Feedback from External Evaluations to Teachers

    Science.gov (United States)

    Hellrung, Katrin; Hartig, Johannes

    2013-01-01

    To improve the quality of teaching, educational accountability needs to include periodic external evaluations of students' performance. This requires evaluation formats which support the development of the educational process and provide information which is understandable for teachers. The aims of this study were to review: (i) how teachers…

  1. Prediction models for the mortality risk in chronic dialysis patients: a systematic review and independent external validation study

    Directory of Open Access Journals (Sweden)

    Ramspek CL

    2017-09-01

    Full Text Available Chava L Ramspek,1 Pauline WM Voskamp,1 Frans J van Ittersum,2 Raymond T Krediet,3 Friedo W Dekker,1 Merel van Diepen1 On behalf of the NECOSAD study group 1Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, 2Department of Nephrology, VU University Medical Center, 3Department of Nephrology, Academic Medical Center, Amsterdam, The Netherlands Objective: In medicine, many more prediction models have been developed than are implemented or used in clinical practice. These models cannot be recommended for clinical use before external validity is established. Though various models to predict mortality in dialysis patients have been published, very few have been validated and none are used in routine clinical practice. The aim of the current study was to identify existing models for predicting mortality in dialysis patients through a review and subsequently to externally validate these models in the same large independent patient cohort, in order to assess and compare their predictive capacities.Methods: A systematic review was performed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA guidelines. To account for missing data, multiple imputation was performed. The original prediction formulae were extracted from selected studies. The probability of death per model was calculated for each individual within the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD. The predictive performance of the models was assessed based on their discrimination and calibration.Results: In total, 16 articles were included in the systematic review. External validation was performed in 1,943 dialysis patients from NECOSAD for a total of seven models. The models performed moderately to well in terms of discrimination, with C-statistics ranging from 0.710 (interquartile range 0.708–0.711 to 0.752 (interquartile range 0.750–0.753 for a time frame of 1 year. According to the calibration, most

  2. [External and internal validity of a multidimensional Locus of control scale of eating attitudes for athletes (LOCSCAS)].

    Science.gov (United States)

    Paquet, Y; Scoffier, S; d'Arripe-Longueville, F

    2016-10-01

    In the field of health psychology, the control has consistently been considered as a protective factor. This protective role has been also highlighted in eating attitudes' domain. However, current studies use the one-dimensional scale of Rotter or the multidimensional health locus of control scale, and no specific eating attitudes' scale in the sport context exists. Moreover, the social influence in previous scales is limited. According to recent works, the purpose of this study was to test the internal and external validity of a multidimensional locus of control scale of eating attitudes for athletes. One hundred and seventy-nine participants were solicited. A confirmatory factorial analysis was conducted in order to test the internal validity of the scale. The scale external validity was tested in relation to eating attitudes. The internal validity of the scale was verified as well as the external validity, which confirmed the importance of taking into consideration social influences. Indeed, the 2 subscales "Trainers, friends" and "Parents, family" are related respectively positively and negatively in eating disorders. Copyright © 2016 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. External Validity of ADHD Inattention and Sluggish Cognitive Tempo Dimensions in Spanish Children With ADHD.

    Science.gov (United States)

    Fenollar Cortés, Javier; Servera, Mateu; Becker, Stephen P; Burns, G Leonard

    2017-06-01

    Few studies have examined whether separate dimensions of Sluggish Cognitive Tempo (SCT)-inconsistent alertness and slowness-have different external correlates from each other as well as symptoms of ADHD inattention (ADHD-IN). Participants were 131 Spanish children (ages 6-16; 72% boys) diagnosed with ADHD. In regression analyses, ADHD-IN was positively associated with hyperactivity/impulsivity, conduct problems, defiance/aggression, anxiety, peer relations problems, and learning problems. SCT-inconsistent alertness was positively associated with hyperactivity/impulsivity and peer relations problems. In contrast, SCT-slowness was negatively associated with hyperactivity/impulsivity and conduct problems and positively associated with depression and learning problems. Results were consistent after controlling for depression, medication status, and sex. The findings support SCT to be a construct with two dimensions that have unique correlates relative to each other as well as ADHD-IN. Future research on SCT should separate these dimensions of SCT to provide a better understanding of the construct.

  5. External validation of the modified Glasgow prognostic score for renal cancer

    Directory of Open Access Journals (Sweden)

    Caroline G Tai

    2014-01-01

    Full Text Available Purpose: The modified Glasgow prognostic Score (mGPS incorporates C-reactive protein and albumin as a clinically useful marker of tumor behavior. The ability of the mGPS to predict metastasis in localized renal cell carcinoma (RCC remains unknown in an external validation cohort. Patients and Methods: Patients with clinically localized clear cell RCC were followed for 1 year post-operatively. Metastases were identified radiologically. Patients were categorized by mGPS score as low-risk (mGPS = 0 points, intermediate-risk (mGPS = 1 point and high-risk (mGPS = 2 points. Univariate, Kaplan-Meier and multivariate Cox regression analyses examined Recurrence -free survival (RFS across patient and disease characteristics. Results: Of the 129 patients in this study, 23.3% developed metastases. Of low, intermediate and high risk patients, 10.1%, 38.9% and 89.9% recurred during the study. After accounting for various patient and tumor characteristics in multivariate analysis including stage and grade, only mGPS was significantly associated with RFS. Compared with low-risk patients, intermediate- and high-risk patients experienced a 4-fold (hazard ratios [HR]: 4.035, 95% confidence interval [CI]: 1.312-12.415, P = 0.015 and 7-fold (HR: 7.012, 95% CI: 2.126-23.123 P < 0.001 risk of metastasis, respectively. Conclusions: mGPS is a robust predictor of metastasis following potentially curative nephrectomy for localized RCC. Clinicians may consider mGPS as an adjunct to identify high-risk patients for possible enrollment into clinical trials or for patient counseling

  6. 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.

  7. 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.

  8. Risk scores for outcome in bacterial meningitis: Systematic review and external validation study.

    Science.gov (United States)

    Bijlsma, Merijn W; Brouwer, Matthijs C; Bossuyt, Patrick M; Heymans, Martijn W; van der Ende, Arie; Tanck, Michael W T; van de Beek, Diederik

    2016-11-01

    To perform an external validation study of risk scores, identified through a systematic review, predicting outcome in community-acquired bacterial meningitis. MEDLINE and EMBASE were searched for articles published between January 1960 and August 2014. Performance was evaluated in 2108 episodes of adult community-acquired bacterial meningitis from two nationwide prospective cohort studies by the area under the receiver operating characteristic curve (AUC), the calibration curve, calibration slope or Hosmer-Lemeshow test, and the distribution of calculated risks. Nine risk scores were identified predicting death, neurological deficit or death, or unfavorable outcome at discharge in bacterial meningitis, pneumococcal meningitis and invasive meningococcal disease. Most studies had shortcomings in design, analyses, and reporting. Evaluation showed AUCs of 0.59 (0.57-0.61) and 0.74 (0.71-0.76) in bacterial meningitis, 0.67 (0.64-0.70) in pneumococcal meningitis, and 0.81 (0.73-0.90), 0.82 (0.74-0.91), 0.84 (0.75-0.93), 0.84 (0.76-0.93), 0.85 (0.75-0.95), and 0.90 (0.83-0.98) in meningococcal meningitis. Calibration curves showed adequate agreement between predicted and observed outcomes for four scores, but statistical tests indicated poor calibration of all risk scores. One score could be recommended for the interpretation and design of bacterial meningitis studies. None of the existing scores performed well enough to recommend routine use in individual patient management. Copyright © 2016 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  11. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Validation of External Corrosion Growth-Rate Using Polarization Resistance and Soil Properties

    Science.gov (United States)

    2010-08-01

    The research project evaluated the use of the Linear Polarization Resistance (LPR) and the Electric Resistance (ER) technologies in estimating the external corrosion growth rates of buried steel pipelines. This was achieved by performing laboratory a...

  14. The predictive and external validity of the STarT Back Tool in Danish primary care

    DEFF Research Database (Denmark)

    Morsø, Lars; Kent, Peter; Albert, Hanne B

    2013-01-01

    PURPOSE: 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. METHODS: Danish primary care patients (n = 344) were compared to a UK cohort. SBT subgroup validity for predicting high activi...

  15. Improving reproducibility and external validity. The role of standardization and data reporting of laboratory rat husbandry and housing.

    Science.gov (United States)

    Fontoura-Andrade, José Luiz; Amorim, Rivadávio Fernandes Batista de; Sousa, João Batista de

    2017-03-01

    To identify the most relevant flaws in standardization in husbandry practices and lack of transparency to report them. This review proposes some measures in order to improve transparency, reproducibility and eventually external validity in experimental surgery experiments with rat model. We performed a search of scientific articles in PUBMED data base. The survey was conducted from august 2016 to January 2017. The keywords used were "reproducibility", "external validity", "rat model", "rat husbandry", "rat housing", and the time frame was up to January 2017. Articles discarded were the ones which the abstract or the key words did not imply that the authors would discuss any relationship of husbandry and housing with the reproducibility and transparency of reporting animal experiment. Reviews and papers that discussed specifically reproducibility and data reporting transparency were laboriously explored, including references for other articles that could fulfil the inclusion criteria. A total of 246 articles were initially found but only 44 were selected. Lack of transparency is the rule and not the exception when reporting results with rat model. This results in poor reproducibility and low external validity with the consequence of considerable loss of time and financial resources. There are still much to be done to improve compliance and adherence of researchers, editors and reviewers to adopt guidelines to mitigate some of the challenges that can impair reproducibility and external validity. Authors and reviewers should avoid pitfalls of absent, insufficient or inaccurate description of relevant information the rat model used. This information should be correctly published or reported on another source easily available for readers. Environmental conditions are well known by laboratory animal personnel and are well controlled in housing facilities, but usually neglected in experimental laboratories when the rat model is a novelty for the researcher.

  16. Development and External Validation of a Melanoma Risk Prediction Model Based on Self-assessed Risk Factors.

    Science.gov (United States)

    Vuong, Kylie; Armstrong, Bruce K; Weiderpass, Elisabete; Lund, Eiliv; Adami, Hans-Olov; Veierod, Marit B; Barrett, Jennifer H; Davies, John R; Bishop, D Timothy; Whiteman, David C; Olsen, Catherine M; Hopper, John L; Mann, Graham J; Cust, Anne E; McGeechan, Kevin

    2016-08-01

    Identifying individuals at high risk of melanoma can optimize primary and secondary prevention strategies. To develop and externally validate a risk prediction model for incident first-primary cutaneous melanoma using self-assessed risk factors. We used unconditional logistic regression to develop a multivariable risk prediction model. Relative risk estimates from the model were combined with Australian melanoma incidence and competing mortality rates to obtain absolute risk estimates. A risk prediction model was developed using the Australian Melanoma Family Study (629 cases and 535 controls) and externally validated using 4 independent population-based studies: the Western Australia Melanoma Study (511 case-control pairs), Leeds Melanoma Case-Control Study (960 cases and 513 controls), Epigene-QSkin Study (44 544, of which 766 with melanoma), and Swedish Women's Lifestyle and Health Cohort Study (49 259 women, of which 273 had melanoma). We validated model performance internally and externally by assessing discrimination using the area under the receiver operating curve (AUC). Additionally, using the Swedish Women's Lifestyle and Health Cohort Study, we assessed model calibration and clinical usefulness. The risk prediction model included hair color, nevus density, first-degree family history of melanoma, previous nonmelanoma skin cancer, and lifetime sunbed use. On internal validation, the AUC was 0.70 (95% CI, 0.67-0.73). On external validation, the AUC was 0.66 (95% CI, 0.63-0.69) in the Western Australia Melanoma Study, 0.67 (95% CI, 0.65-0.70) in the Leeds Melanoma Case-Control Study, 0.64 (95% CI, 0.62-0.66) in the Epigene-QSkin Study, and 0.63 (95% CI, 0.60-0.67) in the Swedish Women's Lifestyle and Health Cohort Study. Model calibration showed close agreement between predicted and observed numbers of incident melanomas across all deciles of predicted risk. In the external validation setting, there was higher net benefit when using the risk prediction

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

    Science.gov (United States)

    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.

  18. Alternative Fistula Risk Score for Pancreatoduodenectomy (a-FRS): Design and International External Validation

    NARCIS (Netherlands)

    Mungroop, Timothy H.; van Rijssen, L. Bengt; van Klaveren, David; Smits, F. Jasmijn; van Woerden, Victor; Linnemann, Ralph J.; de Pastena, Matteo; Klompmaker, Sjors; Marchegiani, Giovanni; Ecker, Brett L.; van Dieren, Susan; Bonsing, Bert; Busch, Olivier R.; van Dam, Ronald M.; Erdmann, Joris; van Eijck, Casper H.; Gerhards, Michael F.; van Goor, Harry; van der Harst, Erwin; de Hingh, Ignace H.; de Jong, Koert P.; Kazemier, Geert; Luyer, Misha; Shamali, Awad; Barbaro, Salvatore; Armstrong, Thomas; Takhar, Arjun; Hamady, Zaed; Klaase, Joost; Lips, Daan J.; Molenaar, I. Quintus; Nieuwenhuijs, Vincent B.; Rupert, Coen; van Santvoort, Hjalmar C.; Scheepers, Joris J.; van der Schelling, George P.; Bassi, Claudio; Vollmer, Charles M.; Steyerberg, Ewout W.; Abu Hilal, Mohammed; Groot Koerkamp, Bas; Besselink, Marc G.

    2017-01-01

    The aim of this study was to develop an alternative fistula risk score (a-FRS) for postoperative pancreatic fistula (POPF) after pancreatoduodenectomy, without blood loss as a predictor. Blood loss, one of the predictors of the original-FRS, was not a significant factor during 2 recent external

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

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Y; Sawant, A [UT Southwestern Medical Center, Dallas, TX (United States)

    2014-06-15

    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

  20. The 12-Item General Health Questionnaire (GHQ-12): reliability, external validity and factor structure in the Spanish population.

    Science.gov (United States)

    Sánchez-López, María del Pilar; Dresch, Virginia

    2008-11-01

    The purpose of this study was to analyze the internal consistency and the external and structure validity of the 12-Item General Health Questionnaire (GHQ-12) in the Spanish general population. A stratified sample of 1001 subjects, ages between 25 and 65 years, taken from the general Spanish population was employed. The GHQ-12 and the Inventory of Situations and Responses of Anxiety-ISRA were administered. A Cronbach's alpha of .76 (Standardized Alpha: .78) and a 3-factor structure (with oblique rotation and maximum likelihood procedure) were obtained. External validity of Factor I (Successful Coping) with the ISRA is very robust (.82; Factor II, .70; Factor III, .75). The GHQ-12 shows adequate reliability and validity in the Spanish population. Therefore, the GHQ-12 can be used with efficacy to assess people's overall psychological well-being and to detect non-psychotic psychiatric problems. Additionally, our results confirm that the GHQ-12 can best be thought of as a multidimensional scale that assesses several distinct aspects of distress, rather than just a unitary screening measure.

  1. 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.

  2. 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 model was able to distinguish well among three risk groups based on tertiles of the risk score. Adding treatment modality to the model did not decrease the predictive power. As a post hoc analysis, we tested the added value of comorbidity as scored by American Society of Anesthesiologists score in a subsample, which increased the C 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.

  3. Distension test in passive external rotation: Validation of a new clinical test for the early diagnosis of shoulder adhesive capsulitis.

    Science.gov (United States)

    Noboa, E; López-Graña, G; Barco, R; Antuña, S

    2015-01-01

    The aim of this study is to evaluate the internal validity of a clinical test for the early diagnosis of shoulder adhesive capsulitis, called the Distension Test in Passive External Rotation (DTPER). The DTPER is performed with the patient standing up, the arm adducted, and the elbow bent at 90°. From this position, a smooth passive external rotation is started, the affected arm being supporting at the wrist with one hand of the examiner and the other maintaining the adducted elbow until the maximum painless point of the rotation is reached. From this point of maximum external rotation with the arm in adduction and with no pain, an abrupt distension movement is made, increasing the external rotation, causing pain in the shoulder if the test is positive. This term was performed on a group of patients with shoulder pain of many origins, in order to analyse the predictive values, sensitivity, specificity, and the likelihood ratio. The DTPER showed a sensitivity of 100% (95% CI; 91.8 to 100%) and a specificity of 90% (95% CI; 82.4 to 94.8%). The positive predictive value was 0.62 and a likelihood ratio of 10.22 (95% CI; 5.5 to 19.01). False positives were only found in patients with subscapular tendinopathies or glenohumeral arthrosis. The DTPER has a high sensitivity for the diagnosis of adhesive capsulitis, and is excluded when it is practically negative. False positives can easily be identified if there is external rotation with no limits (subscapular tendinopathy) or with a simple shoulder X-ray (glenohumeral arthrosis). Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

  4. The 12-Item General Health Questionnaire (GHQ-12): Reliability,external validity and factor structure in the Spanish population

    OpenAIRE

    Sánchez López, María Pilar; Dresch, Virginia

    2008-01-01

    The purpose of this study was to analyze the internal consistency and the external and structure validity of the 12-Item General Health Questionnaire (GHQ-12) in the Spanish general population. A stratified sample of 1001 subjects, ages between 25 and 65 years, taken from the general Spanish population was employed. The GHQ-12 and the Inventory of Situations and Responses of Anxiety-ISRA were administered. A Cronbach’s alpha of .76 (Standardized Alpha: .78) and a 3-factor structure (with obli...

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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.

  7. External Validation of Adjuvant! Online Breast Cancer Prognosis Tool Prioritising Recommendations for Improvement

    NARCIS (Netherlands)

    Hajage, D.; de Rycke, Y.; Bollet, M.; Savignoni, A.; Caly, M.; Pierga, J.Y.; Horlings, H.M.; van de Vijver, M.J.; Vincent-Salomon, A.; Sigal-Zafrani, B.; Senechal, C.; Asselain, B.; Sastre, X.; Reyal, F.

    2011-01-01

    Background: Adjuvant! Online is a web-based application designed to provide 10 years survival probability of patients with breast cancer. Several predictors have not been assessed in the original Adjuvant! Online study. We provide the validation of Adjuvant! Online algorithm on two breast cancer

  8. External validation of Adjuvant! Online breast cancer prognosis tool. Prioritising recommendations for improvement

    NARCIS (Netherlands)

    Hajage, David; de Rycke, Yann; Bollet, Marc; Savignoni, Alexia; Caly, Martial; Pierga, Jean-Yves; Horlings, Hugo M.; van de Vijver, Marc J.; Vincent-Salomon, Anne; Sigal-Zafrani, Brigitte; Senechal, Claire; Asselain, Bernard; Sastre, Xavier; Reyal, Fabien

    2011-01-01

    Adjuvant! Online is a web-based application designed to provide 10 years survival probability of patients with breast cancer. Several predictors have not been assessed in the original Adjuvant! Online study. We provide the validation of Adjuvant! Online algorithm on two breast cancer datasets, and

  9. 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

  10. 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

  11. External validation of severity scoring systems for acute renal failure using a multinational database

    NARCIS (Netherlands)

    Uchino, Shigehiko; Bellomo, Rinaldo; Morimatsu, Hiroshi; Morgera, Stanislao; Schetz, Miet; Tan, Ian; Bouman, Catherine; Macedo, Ettiene; Gibney, Noel; Tolwani, Ashita; Doig, Gordon S.; Oudemans van Straaten, Heleen; Ronco, Claudio; Kellum, John A.

    2005-01-01

    Several different severity scoring systems specific to acute renal failure have been proposed. However, most validation studies of these scoring systems were conducted in a single center or in a small number of centers, often the same ones used for their development. Therefore, it is not known

  12. External validation of clinical decision rules for children with wrist trauma

    NARCIS (Netherlands)

    M.A.M. Mulders (Marjolein A. M.); M.M.J. Walenkamp (Monique); B.F.H. Dubois (Bente F. H.); A. Slaar (Annelie); J.C. Goslings (Carel); N.W.L. Schep (Niels)

    2017-01-01

    textabstractBackground: Clinical decision rules help to avoid potentially unnecessary radiographs of the wrist, reduce waiting times and save costs. Objective: The primary aim of this study was to provide an overview of all existing non-validated clinical decision rules for wrist trauma in children

  13. 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

  14. External Validation of Health Economic Decision Models for Chronic Obstructive Pulmonary Disease (COPD) : Report of the Third COPD Modeling Meeting

    NARCIS (Netherlands)

    Hoogendoorn, Martine; Feenstra, Talitha L.; Asukai, Yumi; Briggs, Andrew H.; Hansen, Ryan N.; Leidl, Reiner; Risebrough, Nancy; Samyshkin, Yevgeniy; Wacker, Margarethe; Rutten-van Molken, Maureen P. M. H.

    Objectives: To validate outcomes of presently available chronic obstructive pulmonary disease (COPD) cost-effectiveness models against results of two large COPD trials the 3-year TOwards a Revolution in COPD Health (TORCH) trial and the 4-year Understanding Potential Long-term Impacts on Function

  15. External validation of the Vulnerable Elder's Survey for predicting mortality and emergency admission in older community-dwelling people: a prospective cohort study.

    OpenAIRE

    Wallace, Emma; McDowell, Ronald; Bennett, Kathleen; Fahey, Tom; Smith, Susan M

    2017-01-01

    Background Prospective external validation of the Vulnerable Elder?s Survey (VES-13) in primary care remains limited. The aim of this study is to externally validate the VES-13 in predicting mortality and emergency admission in older community-dwelling adults. Methods Design: Prospective cohort study with 2 years follow-up (2010?2012). Setting: 15 General Practices (GPs) in the Republic of Ireland. Participants: n?=?862, aged ?70?years, community-dwellers Exposure: VES-13 calculated at baseli...

  16. 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.)

  17. 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...

  18. 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...

  19. Prediction of violent reoffending on release from prison: derivation and external validation of a scalable tool

    OpenAIRE

    Fazel, Seena; Chang, Zheng; Fanshawe, Thomas; Långström, Niklas; Lichtenstein, Paul; Larsson, Henrik; Mallett, Susan

    2016-01-01

    Background: More than 30 million people are released from prison worldwide every year, who include a group at high risk of perpetrating interpersonal violence. Because there is considerable inconsistency and inefficiency in identifying those who would benefit from interventions to reduce this risk, we developed and validated a clinical prediction rule to determine the risk of violent offending in released prisoners. Methods: We did a cohort study of a population of released prison...

  20. 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.

  1. Automated detection of healthcare associated infections: external validation and updating of a model for surveillance of drain-related meningitis.

    Directory of Open Access Journals (Sweden)

    Maaike S M van Mourik

    Full Text Available OBJECTIVE: Automated surveillance of healthcare-associated infections can improve efficiency and reliability of surveillance. The aim was to validate and update a previously developed multivariable prediction model for the detection of drain-related meningitis (DRM. DESIGN: Retrospective cohort study using traditional surveillance by infection control professionals as reference standard. PATIENTS: Patients receiving an external cerebrospinal fluid drain, either ventricular (EVD or lumbar (ELD in a tertiary medical care center. Children, patients with simultaneous drains, <1 day of follow-up or pre-existing meningitis were excluded leaving 105 patients in validation set (2010-2011 and 653 in updating set (2004-2011. METHODS: For validation, the original model was applied. Discrimination, classification and calibration were assessed. For updating, data from all available years was used to optimally re-estimate coefficients and determine whether extension with new predictors is necessary. The updated model was validated and adjusted for optimism (overfitting using bootstrapping techniques. RESULTS: In model validation, the rate of DRM was 17.4/1000 days at risk. All cases were detected by the model. The area under the ROC curve was 0.951. The positive predictive value was 58.8% (95% CI 40.7-75.4 and calibration was good. The revised model also includes Gram stain results. Area under the ROC curve after correction for optimism was 0.963 (95% CI 0.953- 0.974. Group-level prediction was adequate. CONCLUSIONS: The previously developed multivariable prediction model maintains discriminatory power and calibration in an independent patient population. The updated model incorporates all available data and performs well, also after elaborate adjustment for optimism.

  2. Development and Validation of Acyclovir HPLC External Standard Method in Human Plasma: Application to Pharmacokinetic Studies

    Directory of Open Access Journals (Sweden)

    Selvadurai Muralidharan

    2014-01-01

    Full Text Available A simple, rapid, and selective RP-HPLC method was developed for the estimation of acyclovir in human plasma. The method involves a simple protein precipitation technique. Chromatographic separation was carried out on a reverse phase C18 column using mixture of 5 mM ammonium acetate (pH 4.0 and acetonitrile (40 : 60, v/v at a flow rate of 1.0 mL/min with UV detection at 290 nm. The retention time of acyclovir was 4.12 minutes. The method was validated and found to be linear in the range of 25.0–150.0 ng/mL. Validation studies were achieved by using the fundamental parameters, including accuracy, precision, selectivity, sensitivity, linearity and range, stability studies, limit of detection (LOD, and limit of quantitation (LOQ. It shows recovery at 91.0% which is more precise and accurate compared to the other method. These results indicated that the bioanalytical method was linear, precise, and accurate. The new bioanalytical method was successfully applied to a pharmacokinetic linearity study in human plasma.

  3. The development and validation of dried blood spots for external quality assurance of syphilis serology.

    Science.gov (United States)

    Smit, Pieter W; van der Vlis, Thomas; Mabey, David; Changalucha, John; Mngara, Julius; Clark, Benjamin D; Andreasen, Aura; Todd, Jim; Urassa, Mark; Zaba, Basia; Peeling, Rosanna W

    2013-02-26

    Syphilis causes up to 1,500,000 congenital syphilis cases annually. These could be prevented if all pregnant women were screened, and those with syphilis treated with a single dose of penicillin before 28 weeks gestation. In recent years, rapid point-of-care tests have allowed greater access to syphilis screening, especially in rural or remote areas, but the lack of quality assurance of rapid testing has been a concern. We determined the feasibility of using dried blood spots (DBS) as specimens for quality assurance of syphilis serological assays. We developed DBS extraction protocols for use with Treponema pallidum particle agglutination assay (TPPA), Treponema pallidum haemagglutination assay (TPHA) and an enzyme immunoassay (EIA) and compared the results with those using matching plasma samples from the same patient. Since DBS samples showed poor performance with TPHA and EIA (TPHA sensitivity was 50.5% (95% confidence interval: 39.9-61.2%) and EIA specificity was 50.4% (95% CI: 43.7-57.1%), only the DBS TPPA was used in the final evaluation. DBS TPPA showed an sensitivity of 95.5% (95% CI: 91.3-98.0%) and a specificity of 99.0% (95% CI: 98.1-99.5%) compared to TPPA using plasma samples as a reference. DBS samples can be recommended for use with TPPA, and may be of value for external quality assurance of point-of-care syphilis testing.

  4. 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.)

  5. Reanalysis and External Validation of a Decision Tree Model for Detecting Unrecognized Diabetes in Rural Chinese Individuals

    Directory of Open Access Journals (Sweden)

    Zhong Xin

    2017-01-01

    Full Text Available We reanalyzed previous data to develop a more simplified decision tree model as a screening tool for unrecognized diabetes, using basic information in Beijing community health records. Then, the model was validated in another rural town. Only three non-laboratory-based risk factors (age, BMI, and presence of hypertension with fewer branches were used in the new model. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve (AUC for detecting diabetes were calculated. The AUC values in internal and external validation groups were 0.708 and 0.629, respectively. Subjects with high risk of diabetes had significantly higher HOMA-IR, but no significant difference in HOMA-B was observed. This simple tool will help general practitioners and residents assess the risk of diabetes quickly and easily. This study also validates the strong associations of insulin resistance and early stage of diabetes, suggesting that more attention should be paid to the current model in rural Chinese adult populations.

  6. Reanalysis and External Validation of a Decision Tree Model for Detecting Unrecognized Diabetes in Rural Chinese Individuals.

    Science.gov (United States)

    Xin, Zhong; Hua, Lin; Wang, Xu-Hong; Zhao, Dong; Yu, Cai-Guo; Ma, Ya-Hong; Zhao, Lei; Cao, Xi; Yang, Jin-Kui

    2017-01-01

    We reanalyzed previous data to develop a more simplified decision tree model as a screening tool for unrecognized diabetes, using basic information in Beijing community health records. Then, the model was validated in another rural town. Only three non-laboratory-based risk factors (age, BMI, and presence of hypertension) with fewer branches were used in the new model. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve (AUC) for detecting diabetes were calculated. The AUC values in internal and external validation groups were 0.708 and 0.629, respectively. Subjects with high risk of diabetes had significantly higher HOMA-IR, but no significant difference in HOMA-B was observed. This simple tool will help general practitioners and residents assess the risk of diabetes quickly and easily. This study also validates the strong associations of insulin resistance and early stage of diabetes, suggesting that more attention should be paid to the current model in rural Chinese adult populations.

  7. 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.

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

    Science.gov (United States)

    Shea, Beverley J; Bouter, Lex M; Peterson, Joan; Boers, Maarten; Andersson, Neil; Ortiz, Zulma; Ramsay, Tim; Bai, Annie; Shukla, Vijay K; Grimshaw, Jeremy M

    2007-12-26

    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. 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. 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.

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

    Science.gov (United States)

    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

  10. External validation of recombinant antigens for serodiagnosis of machine operator's lung.

    Science.gov (United States)

    Barrera, Coralie; Reboux, Gabriel; Warfolomeow, Isabel; Rognon, Bénédicte; Millon, Laurence; Roussel, Sandrine

    2014-02-01

    Machine operator's lung (MOL) is a hypersensitivity pneumonitis the diagnosis of which is difficult. Our laboratory previously developed an ELISA test using recombinant antigens from Mycobacterium immunogenum isolated in French plant. The objective was to validate the previous ELISA results with ten new suspected cases from Germany. Two serological analyses were performed: ELISA with the six recombinant antigens, and electrosyneresis with crude antigens of M. immunogenum and three other main species isolated from contaminated metalworking fluids. The two recombinant antigens acyl-CoA dehydrogenase and dihydrolipoyl dehydrogenase, combined together, and electrosyneresis are useful in making the diagnosis regardless of the clinical and radiological data. Finally 9 out of the 10 suspected cases were declared as MOL. Despite the geographical distance, the crude and recombinant antigens produced to investigate the clustered French cases also proved to be useful in diagnosing the suspected cases in Germany. © 2013 Wiley Periodicals, Inc.

  11. The development and validation of dried blood spots for external quality assurance of syphilis serology

    Directory of Open Access Journals (Sweden)

    Smit Pieter W

    2013-02-01

    Full Text Available Abstract Background Syphilis causes up to 1,500,000 congenital syphilis cases annually. These could be prevented if all pregnant women were screened, and those with syphilis treated with a single dose of penicillin before 28 weeks gestation. In recent years, rapid point-of-care tests have allowed greater access to syphilis screening, especially in rural or remote areas, but the lack of quality assurance of rapid testing has been a concern. We determined the feasibility of using dried blood spots (DBS as specimens for quality assurance of syphilis serological assays. Methods We developed DBS extraction protocols for use with Treponema pallidum particle agglutination assay (TPPA, Treponema pallidum haemagglutination assay (TPHA and an enzyme immunoassay (EIA and compared the results with those using matching plasma samples from the same patient. Results Since DBS samples showed poor performance with TPHA and EIA (TPHA sensitivity was 50.5% (95% confidence interval: 39.9–61.2% and EIA specificity was 50.4% (95% CI: 43.7–57.1%, only the DBS TPPA was used in the final evaluation. DBS TPPA showed an sensitivity of 95.5% (95% CI: 91.3–98.0% and a specificity of 99.0% (95% CI: 98.1–99.5% compared to TPPA using plasma samples as a reference. Conclusion DBS samples can be recommended for use with TPPA, and may be of value for external quality assurance of point-of-care syphilis testing.

  12. 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.

  13. External validation of the Donor Risk Index and the Eurotransplant Donor Risk Index on the French liver transplantation registry.

    Science.gov (United States)

    Winter, Audrey; Féray, Cyrille; Audureau, Etienne; Écochard, René; Jacquelinet, Christian; Roudot-Thoraval, Françoise; Duvoux, Christophe; Daurès, Jean-Pierre; Landais, Paul

    2017-08-01

    A major limitation to liver transplantation is organ shortage leading to the use of non-optimal liver grafts. The Donor Risk Index has been validated and recommended to select donors/organs. The Eurotransplant Donor Risk Index was derived from the Donor Risk Index. The objective of our study was to perform an external validation of both Donor Risk Index and Eurotransplant-Donor Risk Index against the French liver transplantation Cristal registry according to recommendations of the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis. Liver transplantations performed in France between 2009 and 2013 were used to perform the validation study for the Donor Risk Index and the Eurotransplant-Donor Risk Index respectively. We applied on the French data the models used to construct the Donor Risk Index and the Eurotransplant-Donor Risk Index respectively. Neither the Donor Risk Index nor the Eurotransplant-Donor Risk Index were validated against this dataset. Discrimination and calibration of these scores were not preserved according to our data. Important donor and candidates differences between our dataset and the Organ Procurement and Transplantation Network or the Eurotransplant datasets may explain why the Donor Risk Index and the Eurotransplant-Donor Risk Index appeared unadapted to the French transplant registry. Neither of these risk indexes were suitable to optimize the French liver allocation system. Thus, our next step will be to propose a general adaptive model for a Donor Risk Index. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. External validation of Adjuvant! Online breast cancer prognosis tool. Prioritising recommendations for improvement.

    Directory of Open Access Journals (Sweden)

    David Hajage

    Full Text Available BACKGROUND: Adjuvant! Online is a web-based application designed to provide 10 years survival probability of patients with breast cancer. Several predictors have not been assessed in the original Adjuvant! Online study. We provide the validation of Adjuvant! Online algorithm on two breast cancer datasets, and we determined whether the accuracy of Adjuvant! Online is improved with other well-known prognostic factors. PATIENTS AND METHODS: The French data set is composed of 456 women with early breast cancer. The Dutch data set is composed of 295 women less than 52 years of age. Agreement between observation and Adjuvant! Online prediction was checked, and logistic models were performed to estimate the prognostic information added by risk factors to Adjuvant! Online prediction. RESULTS: Adjuvant! Online prediction was overall well-calibrated in the French data set but failed in some subgroups of such high grade and HER2 positive patients. HER2 status, Mitotic Index and Ki67 added significant information to Adjuvant! Online prediction. In the Dutch data set, the overall 10-year survival was overestimated by Adjuvant! Online, particularly in patients less than 40 years old. CONCLUSION: Adjuvant! Online needs to be updated to adjust overoptimistic results in young and high grade patients, and should consider new predictors such as Ki67, HER2 and Mitotic Index.

  15. External validation of non-invasive prediction models for identifying ultrasonography-diagnosed fatty liver disease in a Chinese population.

    Science.gov (United States)

    Shen, Ya-Nan; Yu, Ming-Xing; Gao, Qian; Li, Yan-Yan; Huang, Jian-Jun; Sun, Chen-Ming; Qiao, Nan; Zhang, Hai-Xia; Wang, Hui; Lu, Qing; Wang, Tong

    2017-07-01

    Several prediction models for fatty liver disease (FLD) are available with limited externally validation and less comprehensive evaluation. The aim was to perform external validation and direct comparison of 4 prediction models (the Fatty Liver Index, the Hepatic Steatosis Index, the ZJU index, and the Framingham Steatosis Index) for FLD both in the overall population and the obese subpopulation.This cross-sectional study included 4247 subjects aged 20 to 65 years recruited from the north of Shanxi Province in China. Anthropometric and biochemical features were collected using standard protocols. FLD was diagnosed by liver ultrasonography. We assessed all models in terms of discrimination, calibration, and decision curve analysis.The original models performed well in terms of discrimination for the overall population, with the area under the receiver operating characteristic curves (AUCs) around 0.85, while AUCs for obese individuals were around 0.68. Nevertheless, the predicted risks did not match well with the observed risks both in the overall population and the obese subpopulation. The FLI 2006 was 1 of the 2 best models in terms of discrimination (AUCs were 0.87 and 0.72 for the overall population and the obese subgroup, respectively) and had the best performance in terms of calibration, and attained the highest net benefit.The FLI 2006 is overall the best tool to identify high risk individuals and has great clinical utility. Nonetheless, it does not perform well enough to quantify the actual risk of FLD, which need to be (re)calibrated for clinical use.

  16. 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.

  17. External validation of the paracetamol-aminotransferase multiplication product to predict hepatotoxicity from paracetamol overdose.

    Science.gov (United States)

    Wong, Anselm; Sivilotti, Marco L A; Dargan, Paul I; Wood, David M; Greene, Shaun L

    2015-01-01

    Risk prediction in paracetamol (acetaminophen, or APAP) poisoning treated with acetylcysteine helps guide initial patient management and disposition. The paracetamol-aminotransferase multiplication product may be a useful and less time-sensitive risk predictor. The aim of this study was to validate this multiplication product in an independent cohort of patients with paracetamol overdose. Using an existing toxicology dataset of poisoned patients from two large inner-city United Kingdom teaching hospitals, we retrospectively identified by electronic search all paracetamol overdoses from February 2005 to March 2013. We assessed the diagnostic accuracy of the multiplication product (serum APAP concentration × alanine transaminase [ALT] activity), especially at the pre-specified cut-off points of 1 500 mg/L × IU/L (10 000 micromol/L × IU/L) and 10 000 mg/L × IU/L (66 000 micromol/L × IU/L). The primary outcome was hepatotoxicity defined by a peak ALT > 1000 IU/L. Of 3823 total paracetamol overdose presentations, there were 2743 acute single, 452 delayed single (> 24 h post overdose), 426 staggered (ingestion over > 1 h), and 202 supratherapeutic ingestions. Altogether, 34 patients developed hepatotoxicity. Among the acute single-ingestion patients, a multiplication product > 10 000 mg/L × IU/L had a sensitivity of 80% (95% confidence interval [CI]: 44%, 96%) and specificity of 99.6% [99.3%, 99.8%], while a product > 1 500 mg/L × IU/L had a sensitivity of 100% [66%, 100%] and specificity of 92% [91%, 93%]. Overall, 16 patients with a multiplication product > 10 000 mg/L × IU/L developed hepatotoxicity (likelihood ratio: 250, 95% CI: 130, 480), and 4 patients with a multiplication product between 1 500 and 10 000 (likelihood ratio: 2.5, 95% CI: 1.0, 6.0). No patient with a product 10 000 mg/L × IU/L was associated with a very high likelihood, and < 1 500 mg/L × IU/L with a very low likelihood, of developing hepatotoxicity in patients treated with acetylcysteine.

  18. Reliability and validity of goniometric iPhone applications for the assessment of active shoulder external rotation.

    Science.gov (United States)

    Mitchell, Katy; Gutierrez, Simran Bakshi; Sutton, Stacy; Morton, Stephanie; Morgenthaler, Andrea

    2014-10-01

    The purpose of this study was to determine the reliability and validity of two smartphone applications: (1) GetMyROM - inclinometery-based and (2) DrGoniometry - photo-based in the measurement of active shoulder external rotation (ER) as compared to standard goniometry (SG). Ninety-four Texas Woman's University Doctor of Physical Therapy students from the School of Physical Therapy - Houston campus, were recruited to participate in this study. Two iPhone applications were compared to SG using both novice and experienced raters. Active shoulder ER range of motion was measured over two time periods in random order by blinded novice and experienced raters. Intra-rater reliability using novice raters for the two applications ranged from an intraclass correlation coefficient (ICC) of 0.79 to 0.81 with SG at 0.82. Inter-rater reliability (novice/expert) for the two applications ranged from an ICC of 0.92 to 0.94 with SG at 0.91. Concurrent validity (when compared to SG) ranged from 0.93 to 0.94. There were no significant differences between the novice and experienced raters. Both applications were found to be reliable and comparable to SG. A photo-based application potentially offers a superior method of measurement as visualizing the landmarks may be simplified in this format and it provides a record of measurement. Further study using patient populations may find the two studied applications are useful as an adjunct for clinical practice.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  1. 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.

  2. Risk prediction models for delirium in the intensive care unit after cardiac surgery: a systematic review and independent external validation.

    Science.gov (United States)

    Lee, A; Mu, J L; Joynt, G M; Chiu, C H; Lai, V K W; Gin, T; Underwood, M J

    2017-03-01

    Numerous risk prediction models are available for predicting delirium after cardiac surgery, but few have been directly compared with one another or been validated in an independent data set. We conducted a systematic review to identify validated risk prediction models of delirium (using the Confusion Assessment Method-Intensive Care Unit tool) after cardiac surgery and assessed the transportability of the risk prediction models on a prospective cohort of 600 consecutive patients undergoing cardiac surgery at a university hospital in Hong Kong from July 2013 to July 2015. The discrimination (c-statistic), calibration (GiViTI calibration belt), and clinical usefulness (decision curve analysis) of the risk prediction models were examined in a stepwise manner. Three published high-quality intensive care unit delirium risk prediction models (n=5939) were identified: Katznelson, the original PRE-DELIRIC, and the international recalibrated PRE-DELIRIC model. Delirium occurred in 83 patients (13.8%, 95% CI: 11.2-16.9%). After updating the intercept and regression coefficients in the Katznelson model, there was fair discrimination (0.62, 95% CI: 0.58-0.66) and good calibration. As the original PRE-DELIRIC model was already validated externally and recalibrated in six countries, we performed a logistic calibration on the recalibrated model and found acceptable discrimination (0.75, 95% CI: 0.72-0.79) and good calibration. Decision curve analysis demonstrated that the recalibrated PRE-DELIRIC risk model was marginally more clinically useful than the Katznelson model. Current models predict delirium risk in the intensive care unit after cardiac surgery with only fair to moderate accuracy and are insufficient for routine clinical use. © The Author 2017. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. 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.

  5. External validation of the ROSC after cardiac arrest (RACA) score in a physician staffed emergency medical service system.

    Science.gov (United States)

    Kupari, Petteri; Skrifvars, Markus; Kuisma, Markku

    2017-03-29

    The return of spontaneous circulation (ROSC) after cardiac arrest (RACA) score may have implications as a quality indicator for the emergency medical services (EMS) system. We aimed to validate this score externally in a physician staffed urban EMS system. We conducted a retrospective cohort study. Data on resuscitation attempts from the Helsinki EMS cardiac arrest registry from 1.1.2008 to 31.12.2010 were collected and analyzed. For each attempted resuscitation the RACA score variables were collected and the score calculated. The endpoint was ROSC defined as palpable pulse over 30 s. Calibration was assessed by comparing predicted and observed ROSC rates in the whole sample, separately for shockable and non-shockable rhythm, and separately for resuscitations lead by a specialist, registrar or medical supervisor (i.e., senior paramedic). Data are presented as medians and interquartile ranges. Statistical testing included chi-square test, the Mann-Whitney U test, Hosmer-Lemeshow goodness of fit test and calculation of 95% confidence intervals (CI) for proportions. A total of 680 patients were included of whom 340 attained ROSC. The RACA score was higher in patients with ROSC (0.62 [0.46-0.69] than in those without (0.46 [0.36-0.57]) (p system for out-of-hospital cardiac arrest patients would allow patient heterogeneity adjustment and measurement of quality of care in analogy to commoly used severity-of-illness- scores developed for the similar purposes for the general intensive care unit population. However, transferring RACA score to another country with different population and EMS system might affect the performance and generalizability of the score. This study found a good overall calibration and moderate discrimination of the RACA score in a physician staffed urban EMS system which suggests external validity of the score. Calibration was suboptimal in patients with a non-shockable rhythm which may due to a local do-not-attempt-resuscitation policy. The lower

  6. Large-scale external validation and comparison of prognostic models: an application to chronic obstructive pulmonary disease.

    Science.gov (United States)

    Guerra, Beniamino; Haile, Sarah R; Lamprecht, Bernd; Ramírez, Ana S; Martinez-Camblor, Pablo; Kaiser, Bernhard; Alfageme, Inmaculada; Almagro, Pere; Casanova, Ciro; Esteban-González, Cristóbal; Soler-Cataluña, Juan J; de-Torres, Juan P; Miravitlles, Marc; Celli, Bartolome R; Marin, Jose M; Ter Riet, Gerben; Sobradillo, Patricia; Lange, Peter; Garcia-Aymerich, Judith; Antó, Josep M; Turner, Alice M; Han, Meilan K; Langhammer, Arnulf; Leivseth, Linda; Bakke, Per; Johannessen, Ane; Oga, Toru; Cosio, Borja; Ancochea-Bermúdez, Julio; Echazarreta, Andres; Roche, Nicolas; Burgel, Pierre-Régis; Sin, Don D; Soriano, Joan B; Puhan, Milo A

    2018-03-02

    External validations and comparisons of prognostic models or scores are a prerequisite for their use in routine clinical care but are lacking in most medical fields including chronic obstructive pulmonary disease (COPD). Our aim was to externally validate and concurrently compare prognostic scores for 3-year all-cause mortality in mostly multimorbid patients with COPD. We relied on 24 cohort studies of the COPD Cohorts Collaborative International Assessment consortium, corresponding to primary, secondary, and tertiary care in Europe, the Americas, and Japan. These studies include globally 15,762 patients with COPD (1871 deaths and 42,203 person years of follow-up). We used network meta-analysis adapted to multiple score comparison (MSC), following a frequentist two-stage approach; thus, we were able to compare all scores in a single analytical framework accounting for correlations among scores within cohorts. We assessed transitivity, heterogeneity, and inconsistency and provided a performance ranking of the prognostic scores. Depending on data availability, between two and nine prognostic scores could be calculated for each cohort. The BODE score (body mass index, airflow obstruction, dyspnea, and exercise capacity) had a median area under the curve (AUC) of 0.679 [1st quartile-3rd quartile = 0.655-0.733] across cohorts. The ADO score (age, dyspnea, and airflow obstruction) showed the best performance for predicting mortality (difference AUC ADO - AUC BODE = 0.015 [95% confidence interval (CI) = -0.002 to 0.032]; p = 0.08) followed by the updated BODE (AUC BODE updated - AUC BODE = 0.008 [95% CI = -0.005 to +0.022]; p = 0.23). The assumption of transitivity was not violated. Heterogeneity across direct comparisons was small, and we did not identify any local or global inconsistency. Our analyses showed best discriminatory performance for the ADO and updated BODE scores in patients with COPD. A limitation to be addressed in future studies is the extension of MSC

  7. Tumor size and invasiveness matters for partial nephrectomy: External validation and modification of the arterial based complexity score.

    Science.gov (United States)

    Kriegmair, Maximilian C; Hetjens, Svetlana; Mandel, Philipp; Wadle, Jula; Budjan, Johannes; Michel, Maurice S; Pfalzgraf, Daniel; Wagener, Nina

    2017-05-01

    Outcome of partial nephrectomy (PN) depends on anatomic features of the renal tumor, which can be assessed by nephrometry scores. The aim was to externally validate and refine the Arterial Based Complexity (ABC) score and to compare it to established systems. Tumors of 300 patients undergoing PN were categorized according to the ABC, RENAL, and PADUA score. Size and tumor invasiveness were combined to form the ABCD score. Correlation analysis and multivariate logistic regression was performed to validate and compare the respective scores as predictors of surgical outcome. The ABC score shows significant correlation with ischemia time (IT) (P < 0.01), opening of the collecting system (CS) (P < 0.01), and conversion to nephrectomy (P = 0.01). In the multivariate analysis, the ABC score was predictive for on-clamp excision (P < 0.01) and opening of the CS (P < 0.01) only. The RENAL and ABCD scores were independent predictors for complications (P = 0.02, P = 0.05), IT (P < 0.01, P = 0.03), on clamp excision (P < 0.01, P < 0.01), and opening of the CS (P < 0.01, P < 0.01). The ABC score correlates well with surgical parameters. Expanding the score by tumor diameter gives the ABCD system. It has similar predictive effectiveness to the well-established RENAL score, but features simplicity by only assessing invasiveness and tumor size. © 2017 Wiley Periodicals, Inc.

  8. 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.

  9. 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.

  10. External and internal validity of open label or double-blind trials in oral anticoagulation: better, worse or just different?

    Science.gov (United States)

    Beyer-Westendorf, J; Büller, H

    2011-11-01

    Currently, few topics in the field of anticoagulant therapy are as intensely discussed as the question: which is the best new oral anticoagulant? The most advanced substances in this field are the oral direct factor Xa-inhibitors rivaroxaban, apixaban and edoxaban and the oral direct thrombin inhibitor dabigatran. All of these substances are currently being tested in very similar phase III trials or are in the process of approval. In these trials, open-label or double-blind double-dummy designs are being used to evaluate the efficacy and safety in prevention and treatment of venous thromboembolism or stroke prevention in atrial fibrillation in several thousands of patients. As a consequence, an intense discussion of the advantages and disadvantages of open-label or double-blind trials is currently under way and interpretation of trial results is often focused on this matter. In general, a blinded trial is regarded as being less subject to bias than an open trial because it minimizes the impact of knowledge of treatment allocation on post-randomized treatment decisions and on reporting of outcomes. However, a blinded trial is not always feasible. Thus, in some respects, the two trial designs offer complementary strengths and weaknesses. This review addresses the risks of bias for internal and external validity of open-label and double-blind anticoagulation trials to help to objectify this debate. © 2011 International Society on Thrombosis and Haemostasis.

  11. 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.

  12. 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

    2017-08-01

    The aim of this study was to conduct external validation of risk prediction scores for invasive candidiasis. 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. 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. 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.

  13. 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),

  14. 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

  15. Internal and external validation of an ESTRO delineation guideline - dependent automated segmentation tool for loco-regional radiation therapy of early breast cancer

    NARCIS (Netherlands)

    Eldesoky, A.R.; Yates, E.S.; Nyeng, T.B.; Thomsen, M.S.; Nielsen, H.M.; Poortmans, P.; Kirkove, C.; Krause, M.; Kamby, C.; Mjaaland, I.; Blix, E.S.; Jensen, I.; Berg, M; Lorenzen, E.L.; Taheri-Kadkhoda, Z.; Offersen, B.V.

    2016-01-01

    BACKGROUND AND PURPOSE: To internally and externally validate an atlas based automated segmentation (ABAS) in loco-regional radiation therapy of breast cancer. MATERIALS AND METHODS: Structures of 60 patients delineated according to the ESTRO consensus guideline were included in four categorized

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

    Science.gov (United States)

    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.

  17. Initial Evidence for the Reliability and Validity of the Student Risk Screening Scale for Internalizing and Externalizing Behaviors at the Elementary Level

    Science.gov (United States)

    Lane, Kathleen Lynne; Oakes, Wendy P.; Harris, Pamela J.; Menzies, Holly Mariah; Cox, Meredith; Lambert, Warren

    2012-01-01

    We report findings of an exploratory validation study of a revised instrument: the Student Risk Screening Scale-Internalizing and Externalizing (SRSS-IE). The SRSS-IE was modified to include seven additional items reflecting characteristics of internalizing behaviors, with proposed items generated from the current literature base, review of…

  18. Understanding the ecological validity of neuropsychological testing using an ethnographic approach.

    Science.gov (United States)

    Gioia, Deborah

    2009-10-01

    Neurocognitive impairment is a defining and disabling feature of schizophrenia and other physical disorders. Most of our understanding about neurocognitive deficits comes from laboratory-based testing in research protocols. There has been little research using direct behavioral community observation over a prolonged period to understand the association of daily functioning with cognitive performance.The purpose of this study was to develop an observational method that could be replicated by researchers interested in viewing cognitive deficits in vivo, and then comparing this data to laboratory measures to affirm the ecological validity of those measures.The eight-step method explained here was developed from the targeted ethnographic study of 10 persons with schizophrenia. Obtaining real world context with this method will help to increase the generalizability of effective cognitive treatments, create improved interventions for this population, and bring into greater relief the coping and compensatory strategies already used by individuals to complete daily tasks.

  19. 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

  20. External validation of type 2 diabetes computer simulation models: definitions, approaches, implications and room for improvement-a protocol for a systematic review.

    Science.gov (United States)

    Ogurtsova, Katherine; Heise, Thomas L; Linnenkamp, Ute; Dintsios, Charalabos-Markos; Lhachimi, Stefan K; Icks, Andrea

    2017-12-29

    Type 2 diabetes mellitus (T2DM), a highly prevalent chronic disease, puts a large burden on individual health and health care systems. Computer simulation models, used to evaluate the clinical and economic effectiveness of various interventions to handle T2DM, have become a well-established tool in diabetes research. Despite the broad consensus about the general importance of validation, especially external validation, as a crucial instrument of assessing and controlling for the quality of these models, there are no systematic reviews comparing such validation of diabetes models. As a result, the main objectives of this systematic review are to identify and appraise the different approaches used for the external validation of existing models covering the development and progression of T2DM. We will perform adapted searches by applying respective search strategies to identify suitable studies from 14 electronic databases. Retrieved study records will be included or excluded based on predefined eligibility criteria as defined in this protocol. Among others, a publication filter will exclude studies published before 1995. We will run abstract and full text screenings and then extract data from all selected studies by filling in a predefined data extraction spreadsheet. We will undertake a descriptive, narrative synthesis of findings to address the study objectives. We will pay special attention to aspects of quality of these models in regard to the external validation based upon ISPOR and ADA recommendations as well as Mount Hood Challenge reports. All critical stages within the screening, data extraction and synthesis processes will be conducted by at least two authors. This protocol adheres to PRISMA and PRISMA-P standards. The proposed systematic review will provide a broad overview of the current practice in the external validation of models with respect to T2DM incidence and progression in humans built on simulation techniques. PROSPERO CRD42017069983 .

  1. 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.

  2. 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

    2015-01-01

    Purpose: 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. Methods: 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. Results: The authors demonstrate that the MMassDx algorithms show good discriminatory performance. AUC for the MMassDx (descriptor) model in the

  3. 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

  4. 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

  5. The Danish National Prescription Registry in studies of a biological pharmaceutical: palivizumab – validation against two external data sources

    Directory of Open Access Journals (Sweden)

    Haerskjold A

    2015-05-01

    Full Text Available Ann Haerskjold,1,2 Lonny Henriksen,2 Susanne Way,1 Mikkel Malham,3 Jesper Hallas,4 Lars Pedersen,5 Lone Graff Stensballe1 1The Child and Adolescent Clinic 4072, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark; 2The Research Unit Women's and Children's Health, The Juliane Marie Centre for Women, Children and Reproduction, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark; 3Department of Pediatrics, Hvidovre University Hospital, Hvidovre, Denmark; 4Department of Clinical Pharmacology, Institute of Public Health, University of Southern Denmark, Denmark; 5Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark Background: National prescription databases are important tools in pharmacoepidemiological studies investigating potential long-term adverse events after drug use. Palivizumab is a biological pharmaceutical used as passive prophylaxis against severe infection with respiratory syncytial virus in high-risk children. Objective: To assess the registration of palivizumab in the Danish National Prescription Registry (DNPR and to examine if palivizumab reimbursement data obtained from the Danish Health and Medicines Authority could serve as a supplement to data from the DNPR. Methods: Registration of palivizumab exposure in the DNPR between 1999 and 2010 was compared to two external data sources: registration of palivizumab exposure in medical records, and palivizumab reimbursement data. Results: During the study period, 182 children with palivizumab exposure were registered in the DNPR. A total of 207 children were registered for palivizumab reimbursement. The sensitivity of palivizumab registration in the DNPR was 26% (20%–34%, and the specificity of no palivizumab registration in the DNPR was 97% (94%–99%, with data from the medical record as the reference. Palivizumab registration sensitivity in reimbursement data was 29% (22%–36%, and the specificity of no palivizumab

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

    Science.gov (United States)

    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.

  7. Real external predictivity of QSAR models. Part 2. New intercomparable thresholds for different validation criteria and the need for scatter plot inspection.

    Science.gov (United States)

    Chirico, Nicola; Gramatica, Paola

    2012-08-27

    The evaluation of regression QSAR model performance, in fitting, robustness, and external prediction, is of pivotal importance. Over the past decade, different external validation parameters have been proposed: Q(F1)(2), Q(F2)(2), Q(F3)(2), r(m)(2), and the Golbraikh-Tropsha method. Recently, the concordance correlation coefficient (CCC, Lin), which simply verifies how small the differences are between experimental data and external data set predictions, independently of their range, was proposed by our group as an external validation parameter for use in QSAR studies. In our preliminary work, we demonstrated with thousands of simulated models that CCC is in good agreement with the compared validation criteria (except r(m)(2)) using the cutoff values normally applied for the acceptance of QSAR models as externally predictive. In this new work, we have studied and compared the general trends of the various criteria relative to different possible biases (scale and location shifts) in external data distributions, using a wide range of different simulated scenarios. This study, further supported by visual inspection of experimental vs predicted data scatter plots, has highlighted problems related to some criteria. Indeed, if based on the cutoff suggested by the proponent, r(m)(2) could also accept not predictive models in two of the possible biases (location, location plus scale), while in the case of scale shift bias, it appears to be the most restrictive. Moreover, Q(F1)(2) and Q(F2)(2) showed some problems in one of the possible biases (scale shift). This analysis allowed us to also propose recalibrated, and intercomparable for the same data scatter, new thresholds for each criterion in defining a QSAR model as really externally predictive in a more precautionary approach. An analysis of the results revealed that the scatter plot of experimental vs predicted external data must always be evaluated to support the statistical criteria values: in some cases high

  8. 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.

  9. 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

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

    Science.gov (United States)

    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.

  11. 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.

  12. "To whom do the results of this trial apply?" External validity of a randomized controlled trial involving 130 patients scheduled for primary total hip replacement

    DEFF Research Database (Denmark)

    Petersen, Mette K; Andersen, Karen Vestergaard; Andersen, Niels T

    2007-01-01

    BACKGROUND: Although the randomized controlled trial (RCT) is regarded as the gold standard for evaluation of the effect of an intervention, its external validity has been questioned. RCTs cannot be expected to produce results that are directly relevant to all patients and all settings, but they ......BACKGROUND: Although the randomized controlled trial (RCT) is regarded as the gold standard for evaluation of the effect of an intervention, its external validity has been questioned. RCTs cannot be expected to produce results that are directly relevant to all patients and all settings......, but they should at least allow patients and clinicians to judge to whom trial results can reasonably be applied. We assessed the external validity of an RCT investigating the efficacy of a fast-track program after total hip replacement. METHODS: 130 patients were identified as potential participants.18 patients...... were excluded, 33 enrolled patients declined to participate, and 79 patients were enrolled and randomized. We studied the distribution of preoperative characteristics and postoperative clinical variables in these 3 groups. RESULTS: A significant difference was found in both preoperative characteristics...

  13. Prognostic score for second-line chemotherapy of advanced non-small-cell lung cancer: external validation in a phase III trial comparing vinflunine with docetaxel.

    Science.gov (United States)

    Di Maio, Massimo; Krzakowski, Maciej; Fougeray, Ronan; Kowalski, Dariusz M; Gridelli, Cesare

    2012-07-01

    A prognostic index for second-line chemotherapy of NSCLC was previously developed, based on individual patient data (IPD) of nine randomized trials. In order to validate the prognostic score in an external dataset, we analysed IPD of a non-inferiority phase III trial comparing vinflunine vs. docetaxel in second-line treatment of advanced NSCLC. Primary endpoint of this analysis was overall survival (OS). The following variables were considered for survival analysis and score calculation: gender, performance status, stage of disease, tumour histology, type of first-line treatment, response to first-line treatment. Cox model, stratified by treatment arm, was used for multivariate analysis. Individual prognostic scores were derived, and patients were divided into 3 categories: best), 5-9 (intermediate), >9 (worst). All 551 patients enrolled in the trial had complete information for the calculation of prognostic score. Median OS in the whole group was 6.9 months, with similar efficacy in the two treatment arms. Median OS was 12.9, 6.9 and 3.8 months in the best, intermediate and worst category, respectively. Cox model showed a significant effect comparing intermediate vs. best category (Hazard Ratio 1.79, 95%CI 1.31-2.47, p=0.0003) and comparing worst vs. best category (Hazard Ratio 3.25, 95%CI 2.18-4.83, ppractise, because a better understanding of factors conditioning life expectancy of patients could greatly help a careful evaluation of risks and benefits associated with therapeutic decisions. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  15. Validated image fusion of dedicated PET and CT for external beam radiation and therapy in the head and neck area.

    NARCIS (Netherlands)

    Vogel, W.V.; Schinagl, D.A.X.; Dalen, J.A. van; Kaanders, J.H.A.M.; Oyen, W.J.G.

    2008-01-01

    AIM: Integration of positron emission tomography (PET) information into computer tomography (CT)- based intensity modulated external beam radiation therapy (IMRT) allows adaptation of the target volume to functional parameters, but only when the image registration procedure is reliable. The aim of

  16. A Perspective on Research on Dishonesty: Limited External Validity Due to the Lack of Possibility of Self-Selection in Experimental Designs.

    Science.gov (United States)

    Houdek, Petr

    2017-01-01

    The aim of this perspective article is to show that current experimental evidence on factors influencing dishonesty has limited external validity. Most of experimental studies is built on random assignments, in which control/experimental groups of subjects face varied sizes of the expected reward for behaving dishonestly, opportunities for cheating, means of rationalizing dishonest behavior etc., and mean groups' reactions are observed. The studies have internal validity in assessing the causal influence of these and other factors, but they lack external validity in organizational, market and other environments. If people can opt into or out of diverse real-world environments, an experiment aimed at studying factors influencing real-life degree of dishonesty should permit for such an option. The behavior of such self-selected groups of marginal subjects would probably contain a larger level of (non)deception than the behavior of average people. The article warns that there are not many studies that would enable self-selection or sorting of participants into varying environments, and that limits current knowledge of the extent and dynamics of dishonest and fraudulent behavior. The article focuses on suggestions how to improve dishonesty research, especially how to avoid the experimenter demand bias.

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

    Science.gov (United States)

    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.

  18. External validation of IASP diagnostic criteria for Complex Regional Pain Syndrome and proposed research diagnostic criteria. International Association for the Study of Pain.

    Science.gov (United States)

    Bruehl, S; Harden, R N; Galer, B S; Saltz, S; Bertram, M; Backonja, M; Gayles, R; Rudin, N; Bhugra, M K; Stanton-Hicks, M

    1999-05-01

    Recent work in our research consortium has raised internal validity concerns regarding the current IASP criteria for Complex Regional Pain Syndrome (CRPS), suggesting problems with inadequate sensitivity and specificity. The current study explored the external validity of these IASP criteria for CRPS. A standardized evaluation of signs and symptoms of CRPS was conducted by study physicians in 117 patients meeting IASP criteria for CRPS, and 43 patients experiencing neuropathic pain with established non-CRPS etiology (e.g. diabetic neuropathy, post-herpetic neuralgia). Multiple discriminant function analyses were used to test the ability of the IASP diagnostic criteria and decision rules, as well as proposed research modifications of these criteria, to discriminate between CRPS patients and those experiencing non-CRPS neuropathic pain. Current IASP criteria and decision rules (e.g. signs or symptoms of edema, or color changes or sweating changes satisfy criterion 3) discriminated significantly between groups (P IASP criteria for CRPS have inadequate specificity and are likely to lead to overdiagnosis. Proposed modifications to these criteria substantially improve their external validity and merit further evaluation.

  19. [Reliability and external validity of a questionnaire to assess the knowledge about risk and cardiovascular disease and in patients attending Spanish community pharmacies].

    Science.gov (United States)

    Amariles, Pedro; Pino-Marín, Daniel; Sabater-Hernández, Daniel; García-Jiménez, Emilio; Roig-Sánchez, Inés; Faus, María José

    2016-11-01

    To determine the test-retest reliability of a questionnaire, with a validation preliminary, to assess knowledge of cardiovascular risk (CVR) and cardiovascular disease in patients attending community pharmacies in Spain. To complement the external validity, establishing the relationship between an educational activity and the increase in knowledge about CVR and cardiovascular disease. Sub-analysis of a controlled clinical study, EMDADER-CV, in which a questionnaire about knowledge concerning CVR was applied at 4 different times. Spanish Community Pharmacies. There were 323 patients in the control group, from the 640 who completed the study. Intraclass correlation coefficient to assess the reliability in 3 comparisons (post-educational activity with week 16, post-educational activity with week 32, and week 16 with week 32); and the non-parametric Friedman test to establish the relationship between an oral and written educational activity with increasing knowledge. For the 323 patients in the 3 comparisons, the intraclass correlation coefficient values were 0.624; 0.608 and 0.801, respectively (fair-good to excellent reliability). So, the Friedman test showed a statistically significant relationship between educational activity and increased knowledge (p cardiovascular disease has a reliability between acceptable and excellent, which added to the previous validation, shows that the instrument meets the criteria of validity and reliability. Furthermore, the questionnaire showed the ability to relate an increase in knowledge with an educational intervention, feature that complements its external validity. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  20. 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.

  1. Use of a 3-Item Short-Form Version of the Barthel Index for Use in Stroke: Systematic Review and External Validation.

    Science.gov (United States)

    MacIsaac, Rachael L; Ali, Myzoon; Taylor-Rowan, Martin; Rodgers, Helen; Lees, Kennedy R; Quinn, Terence J

    2017-03-01

    There may be a potential to reduce the number of items assessed in the Barthel Index (BI), and shortened versions of the BI have been described. We sought to collate all existing short-form BI (SF-BI) and perform a comparative validation using clinical trial data. We performed a systematic review across multidisciplinary electronic databases to find all published SF-BI. Our validation used the VISTA (Virtual International Stroke Trials Archive) resource. We describe concurrent validity (agreement of each SF-BI with BI), convergent and divergent validity (agreement of each SF-BI with other outcome measures available in the data set), predictive validity (association of prognostic factors with SF-BI outcomes), and content validity (item correlation and exploratory factor analyses). From 3546 titles, we found 8 articles describing 6 differing SF-BI. Using acute trial data (n=8852), internal reliability suggested redundancy in BI (Cronbach α, 0.96). Each SF-BI demonstrated a strong correlation with BI, modified Rankin Scale, National Institutes of Health Stroke Scale (all ρ≥0.83; P Scale and 5 domain EuroQOL (ρ≥0.50, P <0.001). Prespecified prognostic factors were associated with SF-BI outcomes (all P <0.001). Our factor analysis described a 3 factor structure, and item reduction suggested an optimal 3-item SF-BI comprising bladder control, transfer, and mobility items in keeping with 1 of the 3-item SF-BI previously described in the literature. There is redundancy in the original BI; we have demonstrated internal and external validity of a 3-item SF-BI that should be simple to use. © 2017 American Heart Association, Inc.

  2. Early Detection of Increased Intracranial Pressure Episodes in Traumatic Brain Injury: External Validation in an Adult and in a Pediatric Cohort.

    Science.gov (United States)

    Güiza, Fabian; Depreitere, Bart; Piper, Ian; Citerio, Giuseppe; Jorens, Philippe G; Maas, Andrew; Schuhmann, Martin U; Lo, Tsz-Yan Milly; Donald, Rob; Jones, Patricia; Maier, Gottlieb; Van den Berghe, Greet; Meyfroidt, Geert

    2017-03-01

    A model for early detection of episodes of increased intracranial pressure in traumatic brain injury patients has been previously developed and validated based on retrospective adult patient data from the multicenter Brain-IT database. The purpose of the present study is to validate this early detection model in different cohorts of recently treated adult and pediatric traumatic brain injury patients. Prognostic modeling. Noninterventional, observational, retrospective study. The adult validation cohort comprised recent traumatic brain injury patients from San Gerardo Hospital in Monza (n = 50), Leuven University Hospital (n = 26), Antwerp University Hospital (n = 19), Tübingen University Hospital (n = 18), and Southern General Hospital in Glasgow (n = 8). The pediatric validation cohort comprised patients from neurosurgical and intensive care centers in Edinburgh and Newcastle (n = 79). None. The model's performance was evaluated with respect to discrimination, calibration, overall performance, and clinical usefulness. In the recent adult validation cohort, the model retained excellent performance as in the original study. In the pediatric validation cohort, the model retained good discrimination and a positive net benefit, albeit with a performance drop in the remaining criteria. The obtained external validation results confirm the robustness of the model to predict future increased intracranial pressure events 30 minutes in advance, in adult and pediatric traumatic brain injury patients. These results are a large step toward an early warning system for increased intracranial pressure that can be generally applied. Furthermore, the sparseness of this model that uses only two routinely monitored signals as inputs (intracranial pressure and mean arterial blood pressure) is an additional asset.

  3. 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

    ; 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. Conclusions: High risk discrimination was validated in the DLCST cohort, mainly determined by nodule size. Age and family history of lung cancer were......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...... 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...

  4. 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…

  5. Examining Evidence for External and Consequential Validity of the First Term General Chemistry Exam from the ACS Examinations Institute

    Science.gov (United States)

    Lewis, Scott E.

    2014-01-01

    Validity of educational research instruments and student assessments has appropriately become a growing interest in the chemistry education research community. Of particular concern is an attention to the consequences to students that result from the interpretation of assessment scores and whether those consequences are swayed by invalidity within…

  6. A method for sensitivity analysis to assess the effects of measurement error in multiple exposure variables using external validation data

    Directory of Open Access Journals (Sweden)

    George O. Agogo

    2016-10-01

    Full Text Available Abstract Background Measurement error in self-reported dietary intakes is known to bias the association between dietary intake and a health outcome of interest such as risk of a disease. The association can be distorted further by mismeasured confounders, leading to invalid results and conclusions. It is, however, difficult to adjust for the bias in the association when there is no internal validation data. Methods We proposed a method to adjust for the bias in the diet-disease association (hereafter, association, due to measurement error in dietary intake and a mismeasured confounder, when there is no internal validation data. The method combines prior information on the validity of the self-report instrument with the observed data to adjust for the bias in the association. We compared the proposed method with the method that ignores the confounder effect, and with the method that ignores measurement errors completely. We assessed the sensitivity of the estimates to various magnitudes of measurement error, error correlations and uncertainty in the literature-reported validation data. We applied the methods to fruits and vegetables (FV intakes, cigarette smoking (confounder and all-cause mortality data from the European Prospective Investigation into Cancer and Nutrition study. Results Using the proposed method resulted in about four times increase in the strength of association between FV intake and mortality. For weakly correlated errors, measurement error in the confounder minimally affected the hazard ratio estimate for FV intake. The effect was more pronounced for strong error correlations. Conclusions The proposed method permits sensitivity analysis on measurement error structures and accounts for uncertainties in the reported validity coefficients. The method is useful in assessing the direction and quantifying the magnitude of bias in the association due to measurement errors in the confounders.

  7. Using Rasch Measurement to Validate the Instrument of Students' Understanding of Models in Science (SUMS)

    Science.gov (United States)

    Wei, Silin; Liu, Xiufeng; Jia, Yuane

    2014-01-01

    Scientific models and modeling play an important role in science, and students' understanding of scientific models is essential for their understanding of scientific concepts. The measurement instrument of "Students' Understanding of Models in Science" (SUMS), developed by Treagust, Chittleborough & Mamiala ("International…

  8. 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.

  9. Internal and external validation of an ESTRO delineation guideline - dependent automated segmentation tool for loco-regional radiation therapy of early breast cancer.

    Science.gov (United States)

    Eldesoky, Ahmed R; Yates, Esben S; Nyeng, Tine B; Thomsen, Mette S; Nielsen, Hanne M; Poortmans, Philip; Kirkove, Carine; Krause, Mechthild; Kamby, Claus; Mjaaland, Ingvil; Blix, Egil S; Jensen, Ingelise; Berg, Martin; Lorenzen, Ebbe L; Taheri-Kadkhoda, Zahra; Offersen, Birgitte V

    2016-12-01

    To internally and externally validate an atlas based automated segmentation (ABAS) in loco-regional radiation therapy of breast cancer. Structures of 60 patients delineated according to the ESTRO consensus guideline were included in four categorized multi-atlas libraries using MIM Maestro™ software. These libraries were used for auto-segmentation in two different patient groups (50 patients from the local institution and 40 patients from other institutions). Dice Similarity Coefficient, Average Hausdorff Distance, difference in volume and time were computed to compare ABAS before and after correction against a gold standard manual segmentation (MS). ABAS reduced the time of MS before and after correction by 93% and 32%, respectively. ABAS showed high agreement for lung, heart, breast and humeral head, moderate agreement for chest wall and axillary nodal levels and poor agreement for interpectoral, internal mammary nodal regions and LADCA. Correcting ABAS significantly improved all the results. External validation of ABAS showed comparable results. ABAS is a clinically useful tool for segmenting structures in breast cancer loco-regional radiation therapy in a multi-institutional setting. However, manual correction of some structures is important before clinical use. The ABAS is now available for routine clinical use in Danish patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. 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).

  11. Reanalysis and External Validation of a Decision Tree Model for Detecting Unrecognized Diabetes in Rural Chinese Individuals

    OpenAIRE

    Xin, Zhong; Hua, Lin; Wang, Xu-Hong; Zhao, Dong; Yu, Cai-Guo; Ma, Ya-Hong; Zhao, Lei; Cao, Xi; Yang, Jin-Kui

    2017-01-01

    We reanalyzed previous data to develop a more simplified decision tree model as a screening tool for unrecognized diabetes, using basic information in Beijing community health records. Then, the model was validated in another rural town. Only three non-laboratory-based risk factors (age, BMI, and presence of hypertension) with fewer branches were used in the new model. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve (AUC) for detect...

  12. 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

  13. 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.

  14. Understanding the Validity of Data: A Knowledge-Based Network Underlying Research Expertise in Scientific Disciplines

    Science.gov (United States)

    Roberts, Ros

    2016-01-01

    This article considers what might be taught to meet a widely held curriculum aim of students being able to understand research in a discipline. Expertise, which may appear as a "chain of practice," is widely held to be underpinned by networks of understanding. Scientific research expertise is considered from this perspective. Within…

  15. 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, p<0.001) but not different from that of the ERSPCRC-HG (0.83) on external 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

  16. 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.

    Directory of Open Access Journals (Sweden)

    Jae Young Park

    Full Text Available 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, p<0.001 but not different from that of the ERSPCRC-HG (0.83 on external 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

  17. External validation of aminoglycoside models used in web calculators and clinical decision support systems after laboratory conversion to serum creatinine isotope dilution mass spectrometry assay.

    Science.gov (United States)

    Wolowich, William R; Steinberg, Jennifer G

    2012-04-01

    Models to predict gentamicin t(½) from serum creatinine (SCr) estimated creatinine clearance (CrCl) are currently being incorporated into smart-device applications and clinical decision support modules without external validation. The aim of this study was to determine whether such models remain viable after conversion to isotope dilution mass spectrometry (IDMS) SCr assay. This study analyzed data from retrospective reviews of the medical records of nonobese adults receiving the aminoglycoside gentamicin and having ≥2 evaluable serum gentamicin concentrations after laboratory IDMS SCr conversion, from January 2008 to August 2009, at a tertiary care hospital in Florida. A literature search found a number of cited aminoglycoside models. This group of models was classified as group 1. The World Wide Web was also searched for the term aminoglycoside dosing calculators, with 6 models found and referred to as group 2. Predictive performance measures were used to compare the model results with the t(½) calculated from gentamicin concentrations using the Nelder-Mead algorithm. The records of 39 patients met the inclusion criteria (23 men, 16 women; age range, 18-86 years; range of estimated CrCl, 55-115 mL/min) and provided the "gold standard" aminoglycoside t(½). A gentamicin t(½) was predicted from several published models (group 1) and from other models used in online smart-device applications (group 2) and clinical decision modules. The median (interquartile range) root mean square errors were 0.48 (0.44 to 0.65) and 0.48 (0.45 to 0.70) hours from group-1 and -2 models, respectively. The median mean relative prediction errors were 9% (-14% to +13%) and 11% (+1% to +21%) from groups 1 and 2. The median mean absolute prediction errors were 21% (19% to 28%) and 21% (20% to 30%) from groups 1 and 2. Adjusting SCr by +20% improved the predictive ability in 3 of 12 cited models and in 5 of 6 models used in applications. Models to predict gentamicin t(½) should be

  18. Lower-limb amputation following foot ulcers in patients with diabetes: classification systems, external validation and comparative analysis.

    Science.gov (United States)

    Monteiro-Soares, Matilde; Martins-Mendes, Daniela; Vaz-Carneiro, António; Dinis-Ribeiro, Mário

    2015-07-01

    This study aimed to validate and compare the existing systems developed to stratify subjects with diabetic foot ulcers by risk of consequent lower extremity amputation. We conducted a prospective cohort study on a consecutive series of patients (mean age of 68 years; 64% male) with active ulcer who were attending our Hospital Diabetic Foot Clinic (n = 293) from January 2010 to March 2013. At baseline, we collected information on the participants' characteristics and the relevant variables. Afterwards, we assessed the predictive value of each variable and each system's prognostic accuracy for amputation occurrence. During a median follow-up of 91 days (interquartile range of 98), ulcers healed in 62% of the subjects. Major amputation occurred in 7% and minor occurred in 17%. Previous ulcer or amputation, ulcer area, and gangrene were associated with amputation occurrence. Nephropathy, pulses number, ulcer aetiology, depth, and number were associated with risk of amputation. Systems typically presented sensitivity values ≥80% and negative likelihood ratios ≤0.5 for the highest risk group; area under the receiver operating characteristic curve ranged from 0.56 to 0.83 and positive likelihood ratios from 1.0 to 5.9. If one chose only major amputation as an outcome, positive predictive values were lower, and negative predictive values tended to be higher. System stages, grades, scores, and/or prognostics were generally associated with amputation, presenting overall substantial accuracy values. Nevertheless, great improvement is possible. A multicentre study validating and refining the existing systems is needed to improve clinical decision-making in this area. Copyright © 2014 John Wiley & Sons, Ltd.

  19. 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

  20. The Test of Understanding in College Economics and its Construct Validity

    Science.gov (United States)

    Lewis, Darrell R.; Dahl, Tor

    1971-01-01

    784 University of Minnesota students in an introductory economics course were tested for this generally positive evaluation. Reservations about the complex application types of questions of the Test of Understanding in College Economics are discussed. (DB)

  1. 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

  2. Understanding Student Teachers’ Behavioural Intention to Use Technology: Technology Acceptance Model (TAM Validation and Testing

    Directory of Open Access Journals (Sweden)

    Kung-Teck, Wong

    2013-01-01

    Full Text Available 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 modelling (SEM was used for model comparison and hypotheses testing. The goodness-of-fit test of the analysis shows partial support of the applicability of the TAM in a Malaysian context. Overall, the TAM accounted for 37.3% of the variance in intention to use technology among student teachers and of the five hypotheses formulated, four are supported. Perceived usefulness is a significant influence on attitude towards computer use and behavioural intention. Perceived ease of use significantly influences perceived usefulness, and finally, behavioural intention is found to be influenced by attitude towards computer use. The findings of this research contribute to the literature by validating the TAM in the Malaysian context and provide several prominent implications for the research and practice of technology integration development.

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

    Science.gov (United States)

    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.

  4. 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.)

  5. External validation of the fatty liver index for identifying nonalcoholic fatty liver disease in a population-based study.

    Science.gov (United States)

    Koehler, Edith M; Schouten, Jeoffrey N L; Hansen, Bettina E; Hofman, Albert; Stricker, Bruno H; Janssen, Harry L A

    2013-09-01

    We aimed to validate the fatty liver index (FLI), an algorithm that is based on waist circumference, body mass index, and levels of triglyceride and γ-glutamyltransferase. We calculated its ability to identify fatty liver disease from any cause or nonalcoholic fatty liver disease (NAFLD) in a large population of white elderly persons. We collected ultrasonography and FLI data from participants of the Rotterdam Study from February 2009 to February 2012; 2652 subjects (mean age, 76.3 ± 6.0 years) were interviewed and received a clinical examination that included abdominal ultrasound, analysis of blood samples during fasting, and anthropometric assessment. The ability of the FLI to detect (nonalcoholic) fatty liver was assessed by using area under the receiver operator characteristic (AUROC) curve analysis. FLI score was associated with NAFLD in multivariable analysis (odds ratio, 1.05; 95% confidence interval [CI], 1.04-1.05; P < .001). FLI identified patients with NAFLD with an AUROC curve of 0.813 (95% CI, 0.797-0.830) and those with fatty liver from any cause with an AUROC curve of 0.807 (95% CI, 0.792-0.823). The FLI (an algorithm that is based on waist circumference, body mass index, and levels of triglyceride and γ-glutamyltransferase) accurately identifies NAFLD, confirmed via ultrasonography, in a large, white, elderly population. Published by Elsevier Inc.

  6. Predictive and External Validity of a Pre-Market Study to Determine the Most Effective Pictorial Health Warning Label Content for Cigarette Packages.

    Science.gov (United States)

    Huang, Li-Ling; Thrasher, James F; Reid, Jessica L; Hammond, David

    2016-05-01

    Studies examining cigarette package pictorial health warning label (HWL) content have primarily used designs that do not allow determination of effectiveness after repeated, naturalistic exposure. This research aimed to determine the predictive and external validity of a pre-market evaluation study of pictorial HWLs. Data were analyzed from: (1) a pre-market convenience sample of 544 adult smokers who participated in field experiments in Mexico City before pictorial HWL implementation (September 2010); and (2) a post-market population-based representative sample of 1765 adult smokers in the Mexican administration of the International Tobacco Control Policy Evaluation Survey after pictorial HWL implementation. Participants in both samples rated six HWLs that appeared on cigarette packs, and also ranked HWLs with four different themes. Mixed effects models were estimated for each sample to assess ratings of relative effectiveness for the six HWLs, and to assess which HWL themes were ranked as the most effective. Pre- and post-market data showed similar relative ratings across the six HWLs, with the least and most effective HWLs consistently differentiated from other HWLs. Models predicting rankings of HWL themes in post-market sample indicated: (1) pictorial HWLs were ranked as more effective than text-only HWLs; (2) HWLs with both graphic and "lived experience" content outperformed symbolic content; and, (3) testimonial content significantly outperformed didactic content. Pre-market data showed a similar pattern of results, but with fewer statistically significant findings. The study suggests well-designed pre-market studies can have predictive and external validity, helping regulators select HWL content. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. In-vivo dosimetry in external radiotherapy with amorphous silicon Portal Imaging Devices: from method to clinical validation

    International Nuclear Information System (INIS)

    Boissard, Philippe

    2012-01-01

    In vivo dose verification is used to prevent major deviations between the prescribed dose and the dose really delivered to the patient. This quality control was, nationally and internationally, widely recommended by scientific organizations. In France, its implementation and its use are now regulated. To do this, small detectors are fixed on the patient skin at the beginning of the treatment. However, the treatment delay is increased and not all treatment techniques could be assessed, such as IMRT plans (Intensity Modulated Radiation Therapy). In this context, Transit dosimetry performed with Electronic Portal Imaging Devices (EPIDs) appears as an interesting alternative for in vivo dose verification. During the treatment session, a transit dose is measured with the EPID, in two dimensions, and the dose in the patient is estimated from back projection of the portal dose. This work presents a quick and simple alternative method for verification of dose delivered to the patient using photon beams. Verifications in cases of complexes patient shapes and Intensity Modulated Radiation Therapy (IMRT) have been improved by using a Clarkson-Cunningham's integration method. 46 phantom test cases were designed to assess the accuracy of the method for 4, 6, 10 and 20 MV photon beams. For some points of interest the dose reconstructed by the method is compared to the dose measured with an ionization chamber. An additional in vivo uncertainty due to day to day deviations is defined and investigated. In the same time, a clinical study was driven during three years. In vivo dosimetry was performed for 494 patients treated for various tumors sites. Most of the patients were treated for a prostate cancer using IMRT. The in vivo dose is here compared to the dose calculated by the Treatment Planning System, TPS. The results of these two ways of validations are within the accepted tolerance of classical in vivo dosimetry. From the phantom study, we have estimated that the standard

  8. Validation and evaluation of measuring methods for the 3D documentation of external injuries in the field of forensic medicine.

    Science.gov (United States)

    Buck, Ursula; Buße, Kirsten; Campana, Lorenzo; Schyma, Christian

    2018-03-01

    Three-dimensional (3D) measurement techniques are gaining importance in many areas. The latest developments brought more cost-effective, user-friendly, and faster technologies onto the market. Which 3D techniques are suitable in the field of forensic medicine and what are their advantages and disadvantages? This wide-ranging study evaluated and validated various 3D measurement techniques for the forensic requirements. High-tech methods as well as low-budget systems have been tested and compared in terms of accuracy, ease of use, expenditure of time, mobility, cost, necessary knowhow, and their limitations. Within this study, various commercial measuring systems of the different techniques were tested. Based on the first results, one measuring system was selected for each technique, which appeared to be the most suitable for the forensic application or is already established in forensic medicine. A body of a deceased, a face and an injury of a living person, and a shoe sole were recorded by 11 people with different professions and previous knowledge using the selected systems. The results were assessed and the personal experiences were evaluated using a questionnaire. In addition, precision investigations were carried out using test objects. The study shows that the hand-held scanner and photogrammetry are very suitable for the 3D documentation of forensic medical findings. Their moderate acquisition costs and easy operation could lead to more frequent application in forensic medicine in the future. For special applications, the stripe-light scanner still has its justification due to its high precision, the flexible application area, and the high reliability. The results show that, thanks to the technological advances, the 3D measurement technology will have more and more impact on the routine of the forensic medical examination.

  9. Furthering our Understanding of Land Surface Interactions using SVAT modelling: Results from SimSphere's Validation

    Science.gov (United States)

    North, Matt; Petropoulos, George; Ireland, Gareth; Rendal, Daisy; Carlson, Toby

    2015-04-01

    With current predicted climate change, there is an increased requirement to gain knowledge on the terrestrial biosphere, for numerous agricultural, hydrological and meteorological applications. To this end, Soil Vegetation Atmospheric Transfer (SVAT) models are quickly becoming the preferred scientific tool to monitor, at fine temporal and spatial resolutions, detailed information on numerous parameters associated with Earth system interactions. Validation of any model is critical to assess its accuracy, generality and realism to distinctive ecosystems and subsequently acts as important step before its operational distribution. In this study, the SimSphere SVAT model has been validated to fifteen different sites of the FLUXNET network, where model performance was statistically evaluated by directly comparing the model predictions vs in situ data, for cloud free days with a high energy balance closure. Specific focus is given to the models ability to simulate parameters associated with the energy balance, namely Shortwave Incoming Solar Radiation (Rg), Net Radiation (Rnet), Latent Heat (LE), Sensible Heat (H), Air Temperature at 1.3m (Tair 1.3m) and Air temperature at 50m (Tair 50m). Comparisons were performed for a number distinctive ecosystem types and for 150 days in total using in-situ data from ground observational networks acquired from the year 2011 alone. Evaluation of the models' coherence to reality was evaluated on the basis of a series of statistical parameters including RMSD, R2, Scatter, Bias, MAE , NASH index, Slope and Intercept. Results showed good to very good agreement between predicted and observed datasets, particularly so for LE, H, Tair 1.3m and Tair 50m where mean error distribution values indicated excellent model performance. Due to the systematic underestimation, poorer simulation accuracies were exhibited for Rg and Rnet, yet all values reported are still analogous to other validatory studies of its kind. In overall, the model

  10. 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.)

  11. 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.)

  12. [External multicentric validation of two scores predicting the risk of relapse in patients with borderline ovarian tumors: The nomogram of Bendifallah and the score of Ouldamer].

    Science.gov (United States)

    Pais, Prescilla; Huchon, Cyrille; Chevrot, Audrey; Cohen, Julien; Fauconnier, Arnaud; Rouzier, Roman; Mimouni, Myriam

    2017-09-01

    Borderline ovarian tumors are rare and can occur in young women. For these patients, a fertility sparing surgery should be discussed. Two predicting borderline ovarian tumor relapse risk models were developed in 2014 (Nomogram of Bendifallah) and 2017 (Score of Ouldamer). This study aimed to valid in an external population, these two scores using a multi-institutional BOT database. In this bicentric and retrospective study, all consecutive patients comprising the variable nomogram documented treated between January 2006 and December 2012 for BOT in centre hospitalier de Poissy-Saint-Germain and hôpital René-Huguenin were included. A ROC model was established for each predicting scores. Sixty-five patients were included in the study. Twelve patients showed a recurrence (19%), three of them experienced an infiltrative cancer (5%). The median time of recurrence was 25 months (range: 8-115). The concordance index for the Nomogram of Bendifallah and the Score of Ouldamer were 0.88 (IC 95% [0.78-0.98]) and 0.87 (IC 95% [0.77-0.96]) respectively. This study from an independent population valids the Bendifallah nomogram and Ouldamer score for clinical use in predicting borderline ovarian recurrence. Copyright © 2017 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

  13. 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

  14. 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

  15. 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.

  16. External Validation of the Prestroke Independence, Sex, Age, National Institutes of Health Stroke Scale Score for Predicting Pneumonia After Stroke Using Data From the China National Stroke Registry.

    Science.gov (United States)

    Zhang, Runhua; Ji, Ruijun; Pan, Yuesong; Jiang, Yong; Liu, Gaifen; Wang, Yilong; Wang, Yongjun

    2017-05-01

    Pneumonia is an important risk factor for mortality and morbidity after stroke. The Prestroke Independence, Sex, Age, National Institutes of Health Stroke Scale (ISAN) score was shown to be a useful tool for predicting stroke-associated pneumonia based on UK multicenter cohort study. We aimed to externally validate the score using data from the China National Stroke Registry (CNSR). Eligible patients with acute ischemic stroke (AIS) and intracerebral hemorrhage (ICH) in the CNSR from 2007 to 2008 were included. The area under the receiver operating characteristic (AUC) curve was used to evaluate discrimination. The Hosmer-Lemeshow goodness of fit test and Pearson correlation coefficient were performed to assess calibration of the model. A total of 19,333 patients (AIS = 14400; ICH = 4933) were included and the overall pneumonia rate was 12.7%. The AUC was .76 (95% confidence interval [CI]: .75-.78) for the subgroup of AIS and .70 (95% CI: .68-.72) for the subgroup of ICH. The Hosmer-Lemeshow test showed the ISAN score with the good calibration for AIS and ICH (P = .177 and .405, respectively). The plot of observed versus predicted pneumonia rates suggested higher correlation for patients with AIS than with ICH (Pearson correlation coefficient = .99 and .83, respectively). The ISAN score was a useful tool for predicting in-hospital pneumonia after acute stroke, especially for patients with AIS. Further validations need to be done in different populations. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  17. External validation of a collar-mounted triaxial accelerometer for second-by-second monitoring of eight behavioural states in dogs.

    Directory of Open Access Journals (Sweden)

    Ingrid den Uijl

    Full Text Available Early detection of disease by an animal owner may motivate them to seek early veterinary advice. Presentation before a more advanced clinical manifestation is evident could lead to more effective treatment and thus benefit the animal's health and welfare. Accelerometers are able to detect changes in specific activities or behaviours, thus indicating early signs of possible adverse health events. The objective of this validation study was to determine whether the detection of eight behavioural states: walk, trot, canter/gallop, sleep, static/inactive, eat, drink, and headshake, by an accelerometer device was sufficiently accurate to be useful in a clinical setting. This fully independent external validation estimated the accuracy of a specific triaxial, collar-mounted accelerometer on a second-by second basis in 51 healthy dogs of different breeds, aged between 6 months and 13 years, weighing >10 kg. The overall diagnostic effectiveness was estimated as: % record correctly classified of > 95% in walk, trot, canter/gallop, eat, drink and headshake and >90% in sleep and static/inactive. The positive predictive values ranged from 93-100%, while the negative predictive values ranged from 96-100%, with exception of static/inactive (86%.This was probably because dogs were placed in unfamiliar kennels where they did not exhibit their typical resting behaviour. The device is worn on a collar, making its use feasible for anyone wanting to monitor their dog's behaviour. The high accuracy in detecting various kinds of behaviour appears promising in assessing canine health and welfare states.

  18. 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.

  19. Stepwise algorithm using computed tomography and magnetic resonance imaging for diagnosis of fat-poor angiomyolipoma in small renal masses: Development and external validation.

    Science.gov (United States)

    Tanaka, Hajime; Fujii, Yasuhisa; Tanaka, Hiroshi; Ishioka, Junichiro; Matsuoka, Yoh; Saito, Kazutaka; Uehara, Sho; Numao, Noboru; Yuasa, Takeshi; Yamamoto, Shinya; Masuda, Hitoshi; Yonese, Junji; Kihara, Kazunori

    2017-07-01

    To develop a stepwise diagnostic algorithm for fat-poor angiomyolipoma in small renal masses. Two cohorts of small renal masses magnetic resonance imaging and clinical findings were analyzed. Based on multivariate analysis, we developed two prediction models for fat-poor angiomyolipoma, the computed tomography model and the computed tomography + magnetic resonance imaging model, and a stepwise algorithm that proposes the sequential use of computed tomography and magnetic resonance imaging. The computed tomography model, which was composed of female aged magnetic resonance imaging model. The computed tomography + magnetic resonance imaging model, consisting of the first three factors of the computed tomography model, low signal intensity and absence of pseudocapsule on T2-weighted magnetic resonance imaging, re-stratified the tumors into low, intermediate and high angiomyolipoma-probability groups. The incidence of fat-poor angiomyolipoma in each group was 0%, 26% and 93%, respectively (area under the curve 0.981). External validation by two readers showed a high area under the curve (0.912 and 0.924) for each. The interobserver agreement was good (kappa score 0.77). The present algorithm differentiates fat-poor angiomyolipoma in small renal masses with high accuracy by adding magnetic resonance imaging to computed tomography in selected patients. © 2017 The Japanese Urological Association.

  20. External validation of the Simplified Acute Physiology Score (SAPS) 3 in a cohort of 28,357 patients from 147 Italian intensive care units.

    Science.gov (United States)

    Poole, Daniele; Rossi, Carlotta; Anghileri, Abramo; Giardino, Michele; Latronico, Nicola; Radrizzani, Danilo; Langer, Martin; Bertolini, Guido

    2009-11-01

    To evaluate the SAPS 3 score predictive ability of hospital mortality in a large external validation cohort. Prospective observational study. A total of 28,357 patients from 147 Italian ICUs joining the Project Margherita national database of the Gruppo italiano per la Valutazione degli interventi in Terapia Intensiva (GiViTI). None. Evaluation of discrimination through ROC analysis and of overall goodness-of-fit through the Cox calibration test. Although discrimination was good, calibration turned out to be poor. The general and the South-Europe Mediterranean countries equations overestimated hospital mortality overall (SMR values 0.73 with 95% CI 0.72-0.75 for both equations) and homogeneously across risk classes. Overprediction was confirmed among important subgroups, with SMR values ranging between 0.47 and 0.82. The result strictly supported by our data is that the SAPS 3 score calibrates inadequately in a large sample of Italian ICU patients and thus should not be used for benchmarking, at least in Italian settings.

  1. 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.

  2. Analysis, Validation, Prediction And Fundamental Understanding Of Rotor Blade Loads In An Unsteady Maneuver

    Science.gov (United States)

    Abhishek, Abhishek

    This study predicts, analyzes, and isolates the mechanisms of main rotor airloads, structural loads, and swashplate servo loads in a severe unsteady maneuver. The objective is, to develop a comprehensive transient rotor analysis for predicting maneuver loads. The main rotor structural loads encountered during unsteady maneuvers are important to size different critical components of the rotor system, particularly for advanced combat helicopters. These include the blade structural loads, control/pitch-link loads, and swashplate servo loads. Accurate and consistent prediction of maneuver loads is necessary to reduce the risks and costs associated with use of prior flight test data as a basis for design. The mechanism of rotor loads in different level flight regimes is well understood -- transonic shock in high speed flight, inter-twinning of blade tip vortices below the rotor disk at low speed transonic flight, and two dynamic stall cycles on retreating blade during high altitude dynamic stall flight. All these physical phenomena can occur simultaneously during a maneuver. The goal is to understand the key mechanisms involved in maneuver and model them accurately. To achieve this, the aerodynamics and structural dynamics of UH-60A rotor in unsteady maneuvering flight is studied separately. For identification of prediction deficiencies in each, first, the measured lift, drag, pitching moment and damper force from the UH-60A Flight Test Program for UTTAS pull-up maneuver (C11029: 2.16g pull-up maneuver) are used to obtain an accurate set of deformations. A multibody finite element blade model, developed for this purpose, is used to perform measured airloads analysis. Next, the resultant blade deformations are used to predict the airloads using lifting-line and RANS CFD aerodynamic models. Both lifting-line as well as CFD analyses predict all three stall cycles with prescribed deformations. From the airloads predicted using prescribed deformations, it is established that

  3. A score to predict and stratify risk of tuberculosis in adult contacts of tuberculosis index cases: a prospective derivation and external validation cohort study.

    Science.gov (United States)

    Saunders, Matthew J; Wingfield, Tom; Tovar, Marco A; Baldwin, Matthew R; Datta, Sumona; Zevallos, Karine; Montoya, Rosario; Valencia, Teresa R; Friedland, Jon S; Moulton, Larry H; Gilman, Robert H; Evans, Carlton A

    2017-11-01

    Contacts of tuberculosis index cases are at increased risk of developing tuberculosis. Screening, preventive therapy, and surveillance for tuberculosis are underused interventions in contacts, particularly adults. We developed a score to predict risk of tuberculosis in adult contacts of tuberculosis index cases. In 2002-06, we recruited contacts aged 15 years or older of index cases with pulmonary tuberculosis who lived in desert shanty towns in Ventanilla, Peru. We followed up contacts for tuberculosis until February, 2016. We used a Cox proportional hazards model to identify index case, contact, and household risk factors for tuberculosis from which to derive a score and classify contacts as low, medium, or high risk. We validated the score in an urban community recruited in Callao, Peru, in 2014-15. In the derivation cohort, we identified 2017 contacts of 715 index cases, and median follow-up was 10·7 years (IQR 9·5-11·8). 178 (9%) of 2017 contacts developed tuberculosis during 19 147 person-years of follow-up (incidence 0·93 per 100 person-years, 95% CI 0·80-1·08). Risk factors for tuberculosis were body-mass index, previous tuberculosis, age, sustained exposure to the index case, the index case being in a male patient, lower community household socioeconomic position, indoor air pollution, previous tuberculosis among household members, and living in a household with a low number of windows per room. The 10-year risks of tuberculosis in the low-risk, medium-risk, and high-risk groups were, respectively, 2·8% (95% CI 1·7-4·4), 6·2% (4·8-8·1), and 20·6% (17·3-24·4). The 535 (27%) contacts classified as high risk accounted for 60% of the tuberculosis identified during follow-up. The score predicted tuberculosis independently of tuberculin skin test and index-case drug sensitivity results. In the external validation cohort, 65 (3%) of 1910 contacts developed tuberculosis during 3771 person-years of follow-up (incidence 1·7 per 100 person-years, 95

  4. Assessment of the External Validity of the National Comprehensive Cancer Network and European Society for Medical Oncology Guidelines for Non-Small-Cell Lung Cancer in a Population of Patients Aged 80 Years and Older.

    Science.gov (United States)

    Battisti, Nicolò Matteo Luca; Sehovic, Marina; Extermann, Martine

    2017-09-01

    Non-small-cell lung cancer (NSCLC) is a disease of the elderly, who are under-represented in clinical trials. This challenges the external validity of the evidence base for its management and of current guidelines, that we evaluated in a population of older patients. We retrieved randomized clinical trials (RCTs) supporting the guidelines and identified 18 relevant topics. We matched a cohort of NSCLC patients aged older than 80 years from the Moffitt Cancer Center database with the studies' eligibility criteria to check their qualification for at least 2 studies. Eligibility > 60% was rated full validity, 30% to 60% partial validity, and validity. We obtained data from 760 elderly patients in stage-adjusted groups and collected 244 RCTs from the National Comprehensive Cancer Network (NCCN) and 148 from the European Society for Medical Oncology (ESMO) guidelines. External validity was deemed insufficient for neoadjuvant chemotherapy in stage III disease (27.37% and 25.26% of patients eligible for NCCN and ESMO guidelines, respectively) and use of bevacizumab (13.86% and 16.27% of patients eligible). For ESMO guidelines, it was inadequate regarding double-agent chemotherapy (25.90% of patients eligible), its duration (24.10%) and therapy for Eastern Cooperative Oncology Group performance status 2 patients (17.74%). For NCCN guidelines external validity was lacking for neoadjuvant chemoradiotherapy in stage IIIA disease (25.86% of patients eligible). Our analysis highlighted the effect of RCT eligibility criteria on guidelines' external validity in elderly patients. Eligibility criteria should be carefully considered in trial design and more studies that do not exclude elderly patients should be included in guidelines. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. 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.

  6. External validation and comparison of two nomograms predicting the probability of Gleason sum upgrading between biopsy and radical prostatectomy pathology in two patient populations: a retrospective cohort study.

    Science.gov (United States)

    Utsumi, Takanobu; Oka, Ryo; Endo, Takumi; Yano, Masashi; Kamijima, Shuichi; Kamiya, Naoto; Fujimura, Masaaki; Sekita, Nobuyuki; Mikami, Kazuo; Hiruta, Nobuyuki; Suzuki, Hiroyoshi

    2015-11-01

    The aim of this study is to validate and compare the predictive accuracy of two nomograms predicting the probability of Gleason sum upgrading between biopsy and radical prostatectomy pathology among representative patients with prostate cancer. We previously developed a nomogram, as did Chun et al. In this validation study, patients originated from two centers: Toho University Sakura Medical Center (n = 214) and Chibaken Saiseikai Narashino Hospital (n = 216). We assessed predictive accuracy using area under the curve values and constructed calibration plots to grasp the tendency for each institution. Both nomograms showed a high predictive accuracy in each institution, although the constructed calibration plots of the two nomograms underestimated the actual probability in Toho University Sakura Medical Center. Clinicians need to use calibration plots for each institution to correctly understand the tendency of each nomogram for their patients, even if each nomogram has a good predictive accuracy. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. External validation of the Probability of repeated admission (Pra) risk prediction tool in older community-dwelling people attending general practice: a prospective cohort study.

    Science.gov (United States)

    Wallace, Emma; McDowell, Ronald; Bennett, Kathleen; Fahey, Tom; Smith, Susan M

    2016-11-14

    Emergency admission is associated with the potential for adverse events in older people and risk prediction models are available to identify those at highest risk of admission. The aim of this study was to externally validate and compare the performance of the Probability of repeated admission (Pra) risk model and a modified version (incorporating a multimorbidity measure) in predicting emergency admission in older community-dwelling people. 15 general practices (GPs) in the Republic of Ireland. n=862, ≥70 years, community-dwelling people prospectively followed up for 2 years (2010-2012). Pra risk model (original and modified) calculated for baseline year where ≥0.5 denoted high risk (patient questionnaire, GP medical record review) of future emergency admission. Emergency admission over 1 year (GP medical record review). descriptive statistics, model discrimination (c-statistic) and calibration (Hosmer-Lemeshow statistic). Of 862 patients, a total of 154 (18%) had ≥1 emergency admission(s) in the follow-up year. 63 patients (7%) were classified as high risk by the original Pra and of these 26 (41%) were admitted. The modified Pra classified 391 (45%) patients as high risk and 103 (26%) were subsequently admitted. Both models demonstrated only poor discrimination (original Pra: c-statistic 0.65 (95% CI 0.61 to 0.70); modified Pra: c-statistic 0.67 (95% CI 0.62 to 0.72)). When categorised according to risk-category model, specificity was highest for the original Pra at cut-point of ≥0.5 denoting high risk (95%), and for the modified Pra at cut-point of ≥0.7 (95%). Both models overestimated the number of admissions across all risk strata. While the original Pra model demonstrated poor discrimination, model specificity was high and a small number of patients identified as high risk. Future validation studies should examine higher cut-points denoting high risk for the modified Pra, which has practical advantages in terms of application in GP. The

  8. Performance of an easy-to-use prediction model for renal patient survival: an external validation study using data from the ERA-EDTA Registry.

    Science.gov (United States)

    Hemke, Aline C; Heemskerk, Martin B A; van Diepen, Merel; Kramer, Anneke; de Meester, Johan; Heaf, James G; Abad Diez, José Maria; Torres Guinea, Marta; Finne, Patrik; Brunet, Philippe; Vikse, Bjørn E; Caskey, Fergus J; Traynor, Jamie P; Massy, Ziad A; Couchoud, Cécile; Groothoff, Jaap W; Nordio, Maurizio; Jager, Kitty J; Dekker, Friedo W; Hoitsma, Andries J

    2018-01-16

    An easy-to-use prediction model for long-term renal patient survival based on only four predictors [age, primary renal disease, sex and therapy at 90 days after the start of renal replacement therapy (RRT)] has been developed in The Netherlands. To assess the usability of this model for use in Europe, we externally validated the model in 10 European countries. Data from the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry were used. Ten countries that reported individual patient data to the registry on patients starting RRT in the period 1995-2005 were included. Patients prediction model was evaluated for the 10- (primary endpoint), 5- and 3-year survival predictions by assessing the calibration and discrimination outcomes. We used a data set of 136 304 patients from 10 countries. The calibration in the large and calibration plots for 10 deciles of predicted survival probabilities showed average differences of 1.5, 3.2 and 3.4% in observed versus predicted 10-, 5- and 3-year survival, with some small variation on the country level. The concordance index, indicating the discriminatory power of the model, was 0.71 in the complete ERA-EDTA Registry cohort and varied according to country level between 0.70 and 0.75. A prediction model for long-term renal patient survival developed in a single country, based on only four easily available variables, has a comparably adequate performance in a wide range of other European countries. © The Author(s) 2018. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. External validation of chemotherapy response score system for histopathological assessment of tumor regression after neoadjuvant chemotherapy in tubo-ovarian high-grade serous carcinoma.

    Science.gov (United States)

    Lee, Jung Yun; Chung, Young Shin; Na, Kiyong; Kim, Hye Min; Park, Cheol Keun; Nam, Eun Ji; Kim, Sunghoon; Kim, Sang Wun; Kim, Young Tae; Kim, Hyun Soo

    2017-11-01

    The chemotherapy response score (CRS) system based on histopathological examination has been recently proposed for tubo-ovarian high-grade serous carcinoma (HGSC) to assess response to neoadjuvant chemotherapy (NAC). This study was aimed at validating the CRS system in an external cohort of tubo-ovarian HGSC patients. This study included 110 tubo-ovarian HGSC patients who underwent NAC followed by interval debulking surgery. The 3-tiered CRS of the omental and adnexal tissue sections was determined by 3 independent pathologists. Differences in patient outcomes according to CRS were analyzed. The CRS system was highly reproducible among the 3 pathologists. Fleiss' kappa value and Kendall's coefficient of concordance for the omental CRS were 0.656 and 0.669, respectively. The omental CRS significantly predicted progression-free survival (PFS). The median PFS of patients whose tumors exhibited the omental CRS 1-2 (15 months) was significantly shorter than that of patients with an omental CRS of 3 (19 months; p=0.016). In addition, after adjusting for age, stage, and debulking status, the omental CRS was an independent prognostic factor for PFS of tubo-ovarian HGSC patients who were treated with NAC (adjusted hazard ratio [HR]=1.74; 95% confidence interval [CI]=1.05-2.87). The CRS system for assessing NAC response was a reproducible prognostic tool in our cohort. The application of the CRS system after NAC can improve survival estimation in HGSC patients. Copyright © 2017. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology

  10. Usefulness of the index of NASH - ION for the diagnosis of steatohepatitis in patients with non-alcoholic fatty liver: An external validation study.

    Science.gov (United States)

    Younes, Ramy; Rosso, Chiara; Petta, Salvatore; Cucco, Monica; Marietti, Milena; Caviglia, Gian Paolo; Ciancio, Alessia; Abate, Maria Lorena; Cammà, Carlo; Smedile, Antonina; Craxì, Antonio; Saracco, Giorgio Maria; Bugianesi, Elisabetta

    2017-10-13

    The non-invasive identification of steatohepatitis (NASH) in patients with Non-Alcoholic Fatty Liver Disease is an unmet need in clinical practice. Index of NASH (ION) is a new tool for the prediction of NASH. We aimed to externally validate ION and to compare it with CK-18. Since necroinflammation precedes fibrosis, we also tested ION in combination with non-invasive tools for fibrosis. We analysed data from 292 Italian patients (169 Southern cohort, and 123 Northern cohort) with an histological diagnosis of NAFLD. The ION, FIB-4 and NFS scores were calculated according to published algorithms. Serum cytokeratin18-Aspartate396 levels and liver stiffness (LS) by Fibroscan were assessed within three months from liver biopsy. The diagnostic accuracy of ION for the identification of NASH was not as satisfactory as reported (area under the ROC curve, AUROC = 0.687 [95% CI = 0.62-0.75]). The proposed cut-off value ≥50 showed a poor sensitivity (Se) (28%) and a good specificity (Sp) (92%), with a positive predictive value (PPV) of 91% and a negative predictive value (NPV) of 30%. A new cut-off value >26 improved Se (73%) but decreased Sp (60%) (PPV of 84% and a NPV of 43%). ION performed slightly better in obese NAFLD (AUROC = 0.700). The combination of ION and markers of fibrosis did not improve the identification of advanced liver disease. ION is not feasible for the non-invasive diagnosis of NASH across different populations of NAFLD patients, mainly because its limited reproducibility in non-obese subjects. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Understanding the Covariation among Childhood Externalizing Symptoms: Genetic and Environmental Influences on Conduct Disorder, Attention Deficit Hyperactivity Disorder, and Oppositional Defiant Disorder Symptoms.

    Science.gov (United States)

    Dick, Danielle M.; Viken, Richard J.; Kaprio, Jaakko; Pulkkinen, Lea; Rose, Richard J.

    2005-01-01

    Conduct disorder (CD), attention deficit hyperactivity disorder (ADHD), and oppositional defiant disorder (ODD) are common childhood externalizing disorders that frequently co-occur. However, the causes of their comorbidity are not well understood. To address that question, we analyzed data from >600 Finnish twin pairs, who completed standardized…

  12. An Exploratory Study of the Concept Map as a Tool To Facilitate the Externalization of Students' Understandings about Global Atmospheric Change in the Interview Setting.

    Science.gov (United States)

    Rye, James A.; Rubba, Peter A.

    The primary purpose of this study was to investigate the effectiveness of two different types of post-instruction concept interviews: one that did and one that did not embed a concept mapping process as means of eliciting students' post-instruction conceptual understandings about the nature of, source of, and problems caused by chlorofluorocarbons…

  13. 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.

  14. 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

  15. TIMES-SS - A promising tool for the assessment of skin sensitization hazard. A characterization with respect to the OECD validation principles for (Q)SARs and an external evaluation for predictivity

    DEFF Research Database (Denmark)

    Patlewicz, Grace; Dimitrov, Sabcho D.; Low, Lawrence K.

    2007-01-01

    and to be scientifically valid in accordance with the OECD principles for (Q)SAR validation. TIMES-SS encodes structure-toxicity and structure-skin metabolism relationships through a number of transformations, some of which are underpinned by mechanistic 3D QSARs. Here, we describe the extent to which the five OECD...... principles are met and in particular the results from an external evaluation exercise that was recently carried out. As part of this exercise, data were generated for 40 new chemicals in the murine local lymph node assay (LLNA) and then compared with predictions made by TIMES-SS. The results were promising...... with an overall good concordance (83%) between experimental and predicted values. Further evaluation of these results highlighted certain inconsistencies which were rationalized by a consideration of reaction chemistry principles for sensitization. Improvements for TIMES-SS were proposed where appropriate. TIMES...

  16. Large-Scale Investigation of the Role of Trait Activation Theory for Understanding Assessment Center Convergent and Discriminant Validity

    Science.gov (United States)

    Lievens, Filip; Chasteen, Christopher S.; Day, Eric Anthony; Christiansen, Neil D.

    2006-01-01

    This study used trait activation theory as a theoretical framework to conduct a large-scale test of the interactionist explanation of the convergent and discriminant validity findings obtained in assessment centers. Trait activation theory specifies the conditions in which cross-situationally consistent and inconsistent candidate performances are…

  17. Development and external validation of a post-discharge bleeding risk score in patients with acute coronary syndrome: The BleeMACS score

    NARCIS (Netherlands)

    Raposeiras-Roubín, Sergio; Faxén, Jonas; Íñiguez-Romo, Andrés; Henriques, Jose Paulo Simao; D'Ascenzo, Fabrizio; Saucedo, Jorge; Szummer, Karolina; Jernberg, Tomas; James, Stefan K.; Juanatey, José Ramón González; Wilton, Stephen B.; Kikkert, Wouter J.; Nuñez-Gil, Iván; Ariza-Sole, Albert; Song, Xiantao; Alexopoulos, Dimitrios; Liebetrau, Christoph; Kawaji, Tetsuma; Moretti, Claudio; Huczek, Zenon; Nie, Shao-Ping; Fujii, Toshiharu; Correia, Luis; Kawashiri, Masa-Aki; Caneiro-Queija, Berenice; Cobas-Paz, Rafael; Acuña, José María García; Southern, Danielle; Alfonso, Emilio; Terol, Belén; Garay, Alberto; Zhang, Dongfeng; Chen, Yalei; Xanthopoulou, Ioanna; Osman, Neriman; Möllmann, Helge; Shiomi, Hiroki; Giordana, Francesca; Gaita, Fiorenzo; Kowara, Michal; Filipiak, Krzysztof; Wang, Xiao; Yan, Yan; Fan, Jing-Yao; Ikari, Yuji; Nakahayshi, Takuya; Sakata, Kenji; Yamagishi, Masakazu; Kalpak, Oliver; Kedev, Sasko; Rivera-Asenjo, Daniel; Abu-Assi, Emad

    2018-01-01

    Background: Accurate 1-year bleeding risk estimation after hospital discharge for acute coronary syndrome(ACS) may help clinicians guide the type and duration of antithrombotic therapy. Currently there are no predictive models for this purpose. The aim of this study was to derive and validate a

  18. Validation Metrics for Improving Our Understanding of Turbulent Transport - Moving Beyond Proof by Pretty Picture and Loud Assertion

    Science.gov (United States)

    Holland, C.

    2013-10-01

    Developing validated models of plasma dynamics is essential for confident predictive modeling of current and future fusion devices. This tutorial will present an overview of the key guiding principles and practices for state-of-the-art validation studies, illustrated using examples from investigations of turbulent transport in magnetically confined plasmas. The primary focus of the talk will be the development of quantiatve validation metrics, which are essential for moving beyond qualitative and subjective assessments of model performance and fidelity. Particular emphasis and discussion is given to (i) the need for utilizing synthetic diagnostics to enable quantitatively meaningful comparisons between simulation and experiment, and (ii) the importance of robust uncertainty quantification and its inclusion within the metrics. To illustrate these concepts, we first review the structure and key insights gained from commonly used ``global'' transport model metrics (e.g. predictions of incremental stored energy or radially-averaged temperature), as well as their limitations. Building upon these results, a new form of turbulent transport metrics is then proposed, which focuses upon comparisons of predicted local gradients and fluctuation characteristics against observation. We demonstrate the utility of these metrics by applying them to simulations and modeling of a newly developed ``validation database'' derived from the results of a systematic, multi-year turbulent transport validation campaign on the DIII-D tokamak, in which comprehensive profile and fluctuation measurements have been obtained from a wide variety of heating and confinement scenarios. Finally, we discuss extensions of these metrics and their underlying design concepts to other areas of plasma confinement research, including both magnetohydrodynamic stability and integrated scenario modeling. Supported by the US DOE under DE-FG02-07ER54917 and DE-FC02-08ER54977.

  19. 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.

  20. A clinical decision rule for the use of plain radiography in children after acute wrist injury: development and external validation of the Amsterdam Pediatric Wrist Rules

    Energy Technology Data Exchange (ETDEWEB)

    Slaar, Annelie; Maas, Mario; Rijn, Rick R. van [University of Amsterdam, Department of Radiology, Academic Medical Centre, Meibergdreef 9, 1105, AZ, Amsterdam (Netherlands); Walenkamp, Monique M.J.; Bentohami, Abdelali; Goslings, J.C. [University of Amsterdam, Trauma Unit, Department of Surgery, Academic Medical Centre, Amsterdam (Netherlands); Steyerberg, Ewout W. [Erasmus MC - University Medical Centre, Department of Public Health, Rotterdam (Netherlands); Jager, L.C. [University of Amsterdam, Emergency Department, Academic Medical Centre, Amsterdam (Netherlands); Sosef, Nico L. [Spaarne Hospital, Department of Surgery, Hoofddorp (Netherlands); Velde, Romuald van [Tergooi Hospitals, Department of Surgery, Hilversum (Netherlands); Ultee, Jan M. [Sint Lucas Andreas Hospital, Department of Surgery, Amsterdam (Netherlands); Schep, Niels W.L. [University of Amsterdam, Trauma Unit, Department of Surgery, Academic Medical Centre, Amsterdam (Netherlands); Maasstadziekenhuis Rotterdam, Department of Surgery, Rotterdam (Netherlands)

    2016-01-15

    In most hospitals, children with acute wrist trauma are routinely referred for radiography. To develop and validate a clinical decision rule to decide whether radiography in children with wrist trauma is required. We prospectively developed and validated a clinical decision rule in two study populations. All children who presented in the emergency department of four hospitals with pain following wrist trauma were included and evaluated for 18 clinical variables. The outcome was a wrist fracture diagnosed by plain radiography. Included in the study were 787 children. The prediction model consisted of six variables: age, swelling of the distal radius, visible deformation, distal radius tender to palpation, anatomical snuffbox tender to palpation, and painful or abnormal supination. The model showed an area under the receiver operator characteristics curve of 0.79 (95% CI: 0.76-0.83). The sensitivity and specificity were 95.9% and 37.3%, respectively. The use of this model would have resulted in a 22% absolute reduction of radiographic examinations. In a validation study, 7/170 fractures (4.1%, 95% CI: 1.7-8.3%) would have been missed using the decision model. The decision model may be a valuable tool to decide whether radiography in children after wrist trauma is required. (orig.)

  1. Brief screening tool for disordered eating in diabetes: internal consistency and external validity in a contemporary sample of pediatric patients with type 1 diabetes.

    Science.gov (United States)

    Markowitz, Jessica T; Butler, Deborah A; Volkening, Lisa K; Antisdel, Jeanne E; Anderson, Barbara J; Laffel, Lori M B

    2010-03-01

    OBJECTIVE To update and validate a diabetes-specific screening tool for disordered eating (the Diabetes Eating Problem Survey [DEPS]) in contemporary youth with type 1 diabetes. RESEARCH DESIGN AND METHODS A total of 112 youth with type 1 diabetes, ages 13-19 years, completed the DEPS. Higher scores on the DEPS indicate more disordered eating behaviors. Youth and their parents also completed additional surveys to examine diabetes-specific family conflict, negative affect related to blood glucose monitoring, youth quality of life, and diabetes burden. Clinicians provided data on height, weight, A1C, and insulin dosing. The DEPS was revised into a shorter, updated measure and validated. RESULTS The revised 16-item DEPS (DEPS-R) displayed excellent internal consistency (Cronbach's alpha = 0.86). Construct validity was demonstrated by positive correlations with zBMI (P = 0.01), A1C (P = 0.001), diabetes-specific family conflict (P diabetes-specific burden (P = 0.0005), and negative correlations with frequency of blood glucose monitoring (P = 0.03) and quality of life (P diabetes-specific self-report measure of disordered eating that can be completed in diabetes. Future studies should focus on using the DEPS-R to identify high-risk populations for prevention of and early intervention for disordered eating behaviors.

  2. A clinical decision rule for the use of plain radiography in children after acute wrist injury: development and external validation of the Amsterdam Pediatric Wrist Rules

    International Nuclear Information System (INIS)

    Slaar, Annelie; Maas, Mario; Rijn, Rick R. van; Walenkamp, Monique M.J.; Bentohami, Abdelali; Goslings, J.C.; Steyerberg, Ewout W.; Jager, L.C.; Sosef, Nico L.; Velde, Romuald van; Ultee, Jan M.; Schep, Niels W.L.

    2016-01-01

    In most hospitals, children with acute wrist trauma are routinely referred for radiography. To develop and validate a clinical decision rule to decide whether radiography in children with wrist trauma is required. We prospectively developed and validated a clinical decision rule in two study populations. All children who presented in the emergency department of four hospitals with pain following wrist trauma were included and evaluated for 18 clinical variables. The outcome was a wrist fracture diagnosed by plain radiography. Included in the study were 787 children. The prediction model consisted of six variables: age, swelling of the distal radius, visible deformation, distal radius tender to palpation, anatomical snuffbox tender to palpation, and painful or abnormal supination. The model showed an area under the receiver operator characteristics curve of 0.79 (95% CI: 0.76-0.83). The sensitivity and specificity were 95.9% and 37.3%, respectively. The use of this model would have resulted in a 22% absolute reduction of radiographic examinations. In a validation study, 7/170 fractures (4.1%, 95% CI: 1.7-8.3%) would have been missed using the decision model. The decision model may be a valuable tool to decide whether radiography in children after wrist trauma is required. (orig.)

  3. Predicting the risk of Chronic Kidney Disease in Men and Women in England and Wales: prospective derivation and external validation of the QKidney® Scores

    Directory of Open Access Journals (Sweden)

    Coupland Carol

    2010-06-01

    Full Text Available Abstract Background Chronic Kidney Disease is a major cause of morbidity and interventions now exist which can reduce risk. We sought to develop and validate two new risk algorithms (the QKidney® Scores for estimating (a the individual 5 year risk of moderate-severe CKD and (b the individual 5 year risk of developing End Stage Kidney Failure in a primary care population. Methods We conducted a prospective open cohort study using data from 368 QResearch® general practices to develop the scores. We validated the scores using two separate sets of practices - 188 separate QResearch® practices and 364 practices contributing to the THIN database. We studied 775,091 women and 799,658 men aged 35-74 years in the QResearch® derivation cohort, who contributed 4,068,643 and 4,121,926 person-years of observation respectively. We had two main outcomes (a moderate-severe CKD (defined as the first evidence of CKD based on the earliest of any of the following: kidney transplant; kidney dialysis; diagnosis of nephropathy; persistent proteinuria; or glomerular filtration rate of We derived separate risk equations for men and women. We calculated measures of calibration and discrimination using the two separate validation cohorts. Results Our final model for moderate-severe CKD included: age, ethnicity, deprivation, smoking, BMI, systolic blood pressure, diabetes, rheumatoid arthritis, cardiovascular disease, treated hypertension, congestive cardiac failure; peripheral vascular disease, NSAID use and family history of kidney disease. In addition, it included SLE and kidney stones in women. The final model for End Stage Kidney Failure was similar except it did not include NSAID use. Each risk prediction algorithms performed well across all measures in both validation cohorts. For the THIN cohort, the model to predict moderate-severe CKD explained 56.38% of the total variation in women and 57.49% for men. The D statistic values were high with values of 2.33 for

  4. External validity of a prognostic score for acute heart failure based on the Epidemiology of Acute Heart Failure in Emergency Departments registry: the EAHFE-3D scale.

    Science.gov (United States)

    García-Gutiérrez, Susana; Quintana López, José M; Antón-Ladislao, Ane; Gallardo Rebollal, María Soledad; Rilo Miranda, Irene; Morillas Bueno, Miren; Murga Eizagaetxebarria, Nekane; Palenzuela Arocena, Ricardo; Pulido, Esther; Barrio Beraza, Irantzu; Aguirre Larracoechea, Urko; Arostegui, Inmaculada

    2018-01-01

    To validate the EAHFE-3D scale, based on the Acute Heart Failure in Emergency Departments registry, in a cohort of patients attended for acute heart failure. Study of a multipurpose cohort of patients with acute heart failure in 3 hospitals in the Basque Country between 2011 and 2013. We extracted age, baseline New York Heart Association functional class, systolic blood pressure, baseline arterial oxygen saturation, sodium level in blood, and emergency department treatments (noninvasive mechanical ventilation, use of inotropic agents and vasopressors) in order to calculate each patient's EAHFE-3D score. The main outcome variable was mortality within 3 days of arrival at the emergency department. The patient sample for score validation consisted of 717 patients with complete information. The model's intercept was 0.5 (95% CI, -2.7 to 3.7) and the slope was 1.3 (95% CI, 0.4 to 2.2). The area under the receiver operating characteristic curve was 0.76 (95% CI, 0.58 to 0.94). The EAHFE-3D scale's ability to discriminate was good in this patient sample and similar to that reported by the authors who developed the scale; however, calibration was poor. The scale should be studied further before it is applied in clinical practice.

  5. Investigation of element distribution and homogeneity of TXRF samples using SR-micro-XRF to validate the use of an internal standard and improve external standard quantification.

    Science.gov (United States)

    Horntrich, C; Smolek, S; Maderitsch, A; Simon, R; Kregsamer, P; Streli, C

    2011-06-01

    Total reflection X-ray fluorescence analysis (TXRF) offers a nondestructive qualitative and quantitative analysis of trace elements. Due to its outstanding properties TXRF is widely used in the semiconductor industry for the analysis of silicon wafer surfaces and in the chemical analysis of liquid samples. Two problems occur in quantification: the large statistical uncertainty in wafer surface analysis and the validity of using an internal standard in chemical analysis. In general TXRF is known to allow for linear calibration. For small sample amounts (low nanogram (ng) region) the thin film approximation is valid neglecting absorption effects of the exciting and the detected radiation. For higher total amounts of samples deviations from the linear relation between fluorescence intensity and sample amount can be observed. This could be caused by the sample itself because inhomogeneities and different sample shapes can lead to differences of the emitted fluorescence intensities and high statistical errors. The aim of the study was to investigate the elemental distribution inside a sample. Single and multi-element samples were investigated with Synchrotron-radiation-induced micro X-ray Fluorescence Analysis (SR-μ-XRF) and with an optical microscope. It could be proven that the microscope images are all based on the investigated elements. This allows the determination of the sample shape and potential inhomogeneities using only light microscope images. For the multi-element samples, it was furthermore shown that the elemental distribution inside the samples is homogeneous. This justifies internal standard quantification.

  6. Population-Based Validation of the 2014 ISUP Gleason Grade Groups in Patients Treated With Radical Prostatectomy, Brachytherapy, External Beam Radiation, or no Local Treatment.

    Science.gov (United States)

    Pompe, Raisa S; Davis-Bondarenko, Helen; Zaffuto, Emanuele; Tian, Zhe; Shariat, Shahrokh F; Leyh-Bannurah, Sami-Ramzi; Schiffmann, Jonas; Saad, Fred; Huland, Hartwig; Graefen, Markus; Tilki, Derya; Karakiewicz, Pierre I

    2017-05-01

    To test discriminant ability of the 2014 ISUP Gleason grade groups (GGG) for prediction of prostate cancer specific mortality (PCSM) after radical prostatectomy (RP), brachytherapy (BT), external beam radiation (EBRT) or no local treatment (NLT) relative to traditional Gleason grading (TGG). In the Surveillance, Epidemiology, and End Results (SEER)-database (2004-2009), 2,42,531 non-metastatic prostate cancer (PCa) patients were identified, who underwent local treatment (RP, BT, EBRT only) or NLT. Follow-up endpoint was PCSM. Biopsy and/or pathological Gleason score (GS) were categorized as TGG ≤6, 7, 8-10 or GGG: I (≤6), II (3 + 4), III (4 + 3), IV (8), and V (9-10). Kaplan-Meier plots, multivariable Cox regression analyses and receiver operating characteristics (ROC) area under the curve analyses (AUC) were used. Median follow-up was 76 months (IQR: 59-94). For the four examined treatment modalities, all five GGG strata and all three TGG strata independently predicted PCSM. GGG yielded 1.5-fold or greater HR differences between GGG II and GGG III, and twofold or greater HR differences between GGG IV and GGG V. Relative to TGG, GGG added 0.4-1.1% to AUC. This large population-based cohort study confirms the added discriminant properties of the novel GGG strata and confirms a modest gain in predictive accuracy. Prostate 77: 686-693, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. External Validation of the ASTER GDEM2, GMTED2010 and CGIAR-CSI- SRTM v4.1 Free Access Digital Elevation Models (DEMs in Tunisia and Algeria

    Directory of Open Access Journals (Sweden)

    Djamel Athmania

    2014-05-01

    Full Text Available Digital Elevation Models (DEMs including Advanced Spaceborne Thermal Emission and Reflection Radiometer-Global Digital Elevation Model (ASTER GDEM, Shuttle Radar Topography Mission (SRTM, and Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010 are freely available for nearly the entire earth’s surface. DEMs that are usually subject to errors need to be evaluated using reference elevation data of higher accuracy. This work was performed to assess the vertical accuracy of the ASTER GDEM version 2, (ASTER GDEM2, the Consultative Group on International Agriculture Research-Consortium for Spatial Information (CGIAR-CSI SRTM version 4.1 (SRTM v4.1 and the systematic subsample GMTED2010, at their original spatial resolution, using Global Navigation Satellite Systems (GNSS validation points. Two test sites, the Anaguid Saharan platform in southern Tunisia and the Tebessa basin in north eastern Algeria, were chosen for accuracy assessment of the above mentioned DEMs, based on geostatistical and statistical measurements. Within the geostatistical approach, empirical variograms of each DEM were compared with those of the GPS validation points. Statistical measures were computed from the elevation differences between the DEM pixel value and the corresponding GPS point. For each DEM, a Root Mean Square Error (RMSE was determined for model validation. In addition, statistical tools such as frequency histograms and Q-Q plots were used to evaluate error distributions in each DEM. The results indicate that the vertical accuracy of SRTM model is much higher than ASTER GDEM2 and GMTED2010 for both sites. In Anaguid test site, the vertical accuracy of SRTM is estimated 3.6 m (in terms of RMSE 5.3 m and 4.5 m for the ASTERGDEM2 and GMTED2010 DEMs, respectively. In Tebessa test site, the overall vertical accuracy shows a RMSE of 9.8 m, 8.3 m and 9.6 m for ASTER GDEM 2, SRTM and GMTED2010 DEM, respectively. This work is the first study to report the

  8. External validation of the Prostate Cancer Prevention Trial and the European Randomized Study of Screening for Prostate Cancer risk calculators in a Chinese cohort.

    Science.gov (United States)

    Zhu, Yao; Wang, Jin-You; Shen, Yi-Jun; Dai, Bo; Ma, Chun-Guang; Xiao, Wen-Jun; Lin, Guo-Wen; Yao, Xu-Dong; Zhang, Shi-Lin; Ye, Ding-Wei

    2012-09-01

    Several prediction models have been developed to estimate the outcomes of prostate biopsies. Most of these tools were designed for use with Western populations and have not been validated across different ethnic groups. Therefore, we evaluated the predictive value of the Prostate Cancer Prevention Trial (PCPT) and the European Randomized Study of Screening for Prostate Cancer (ERSPC) risk calculators in a Chinese cohort. Clinicopathological information was obtained from 495 Chinese men who had undergone extended prostate biopsies between January 2009 and March 2011. The estimated probabilities of prostate cancer and high-grade disease (Gleason >6) were calculated using the PCPT and ERSPC risk calculators. Overall measures, discrimination, calibration and clinical usefulness were assessed for the model evaluation. Of these patients, 28.7% were diagnosed with prostate cancer and 19.4% had high-grade disease. Compared to the PCPT model and the prostate-specific antigen (PSA) threshold of 4 ng ml(-1), the ERSPC risk calculator exhibited better discriminative ability for predicting positive biopsies and high-grade disease (the area under the curve was 0.831 and 0.852, respectively, Pcalculator in the validation dataset. Both prediction models demonstrated miscalibration: the risk of prostate cancer and high-grade disease was overestimated by approximately 20% for a wide range of predicted probabilities. In conclusion, the ERSPC risk calculator outperformed both the PCPT model and the PSA threshold of 4 ng ml(-1) in predicting prostate cancer and high-grade disease in Chinese patients. However, the prediction tools derived from Western men significantly overestimated the probability of prostate cancer and high-grade disease compared to the outcomes of biopsies in a Chinese cohort.

  9. External validation of equations to estimate resting energy expenditure in 14952 adults with overweight and obesity and 1948 adults with normal weight from Italy.

    Science.gov (United States)

    Bedogni, Giorgio; Bertoli, Simona; Leone, Alessandro; De Amicis, Ramona; Lucchetti, Elisa; Agosti, Fiorenza; Marazzi, Nicoletta; Battezzati, Alberto; Sartorio, Alessandro

    2017-11-24

    We cross-validated 28 equations to estimate resting energy expenditure (REE) in a very large sample of adults with overweight or obesity. 14952 Caucasian men and women with overweight or obesity and 1498 with normal weight were studied. REE was measured using indirect calorimetry and estimated using two meta-regression equations and 26 other equations. The correct classification fraction (CCF) was defined as the fraction of subjects whose estimated REE was within 10% of measured REE. The highest CCF was 79%, 80%, 72%, 64%, and 63% in subjects with normal weight, overweight, class 1 obesity, class 2 obesity, and class 3 obesity, respectively. The Henry weight and height and Mifflin equations performed equally well with CCFs of 77% vs. 77% for subjects with normal weight, 80% vs. 80% for those with overweight, 72% vs. 72% for those with class 1 obesity, 64% vs. 63% for those with class 2 obesity, and 61% vs. 60% for those with class 3 obesity. The Sabounchi meta-regression equations offered an improvement over the above equations only for class 3 obesity (63%). The accuracy of REE equations decreases with increasing values of body mass index. The Henry weight & height and Mifflin equations are similarly accurate and the Sabounchi equations offer an improvement only in subjects with class 3 obesity. Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  10. 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

    DEFF Research Database (Denmark)

    Stræde, Mia; Brabrand, Mikkel

    2014-01-01

    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. METHODS: Pre-planned prospective observational cohort study. SETTING: Danish 460.......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, χ2 = 2.68 (10 degrees of freedom), P = 0.998 and χ2 = 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, χ2 = 5.56 (10 degrees of freedom), P = 0.234. CONCLUSION: 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....

  11. Prediction of incomplete primary debulking surgery in patients with advanced ovarian cancer: An external validation study of three models using computed tomography.

    Science.gov (United States)

    Rutten, Iris J G; van de Laar, Rafli; Kruitwagen, Roy F P M; Bakers, Frans C H; Ploegmakers, Marieke J M; Pappot, Teun W F; Beets-Tan, Regina G H; Massuger, Leon F A G; Zusterzeel, Petra L M; Van Gorp, Toon

    2016-01-01

    To test the ability of three prospectively developed computed tomography (CT) models to predict incomplete primary debulking surgery in patients with advanced (International Federation of Gynecology and Obstetrics stages III-IV) ovarian cancer. Three prediction models to predict incomplete surgery (any tumor residual >1cm in diameter) previously published by Ferrandina (models A and B) and by Gerestein were applied to a validation cohort consisting of 151 patients with advanced epithelial ovarian cancer. All patients were treated with primary debulking surgery in the Eastern part of the Netherlands between 2000 and 2009 and data were retrospectively collected. Three individual readers evaluated the radiographic parameters and gave a subjective assessment. Using the predicted probabilities from the models, the area under the curve (AUC) was calculated which represents the discriminative ability of the model. The AUC of the Ferrandina models was 0.56, 0.59 and 0.59 in model A, and 0.55, 0.60 and 0.59 in model B for readers 1, 2 and 3, respectively. The AUC of Gerestein's model was 0.69, 0.61 and 0.69 for readers 1, 2 and 3, respectively. AUC values of 0.69 and 0.63 for reader 1 and 3 were found for subjective assessment. Models to predict incomplete surgery in advanced ovarian cancer have limited predictive ability and their reproducibility is questionable. Subjective assessment seems as successful as applying predictive models. Present prediction models are not reliable enough to be used in clinical decision-making and should be interpreted with caution. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Internally- and Externally-Driven Network Transitions as a Basis for Automatic and Strategic Processes in Semantic Priming: Theory and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Itamar eLerner

    2014-04-01

    Full Text Available For the last four decades, semantic priming – the facilitation in recognition of a target word when it follows the presentation of a semantically related prime word – has been a central topic in research of human cognitive processing. Studies have drawn a complex picture of findings which demonstrated the sensitivity of this priming effect to a unique combination of variables, including, but not limited to, the type of relatedness between primes and targets, the prime-target SOA, the relatedness proportion in the stimuli list and the specific task subjects are required to perform. Automatic processes depending on the activation patterns of semantic representations in memory and controlled strategies adapted by individuals when attempting to maximize their recognition performance have both been implicated in contributing to the results. Lately, we have published a new model of semantic priming that addresses the majority of these findings within one conceptual framework. In our model, semantic memory is depicted as an attractor neural network in which stochastic transitions from one stored pattern to another are continually taking place due to synaptic depression mechanisms. We have shown how such transitions, in combination with a reinforcement-learning rule that adjusts their pace, resemble the classic automatic and controlled processes involved in semantic priming and account for a great number of the findings in the literature. Here, we review the core findings of our model and present new simulations that show how similar principles of parameter-adjustments could account for additional data not addressed in our previous studies, such as the relation between expectancy and inhibition in priming, target frequency and target degradation effects. Finally, we describe two human experiments that validate several key predictions of the model.

  13. Internally- and externally-driven network transitions as a basis for automatic and strategic processes in semantic priming: theory and experimental validation.

    Science.gov (United States)

    Lerner, Itamar; Shriki, Oren

    2014-01-01

    For the last four decades, semantic priming-the facilitation in recognition of a target word when it follows the presentation of a semantically related prime word-has been a central topic in research of human cognitive processing. Studies have drawn a complex picture of findings which demonstrated the sensitivity of this priming effect to a unique combination of variables, including, but not limited to, the type of relatedness between primes and targets, the prime-target Stimulus Onset Asynchrony (SOA), the relatedness proportion (RP) in the stimuli list and the specific task subjects are required to perform. Automatic processes depending on the activation patterns of semantic representations in memory and controlled strategies adapted by individuals when attempting to maximize their recognition performance have both been implicated in contributing to the results. Lately, we have published a new model of semantic priming that addresses the majority of these findings within one conceptual framework. In our model, semantic memory is depicted as an attractor neural network in which stochastic transitions from one stored pattern to another are continually taking place due to synaptic depression mechanisms. We have shown how such transitions, in combination with a reinforcement-learning rule that adjusts their pace, resemble the classic automatic and controlled processes involved in semantic priming and account for a great number of the findings in the literature. Here, we review the core findings of our model and present new simulations that show how similar principles of parameter-adjustments could account for additional data not addressed in our previous studies, such as the relation between expectancy and inhibition in priming, target frequency and target degradation effects. Finally, we describe two human experiments that validate several key predictions of the model.

  14. Couples' joint decision-making: the construction and validation of a key proxy for understanding gender relations in contemporary families

    Directory of Open Access Journals (Sweden)

    Maira Covre-Sussai

    2014-06-01

    Full Text Available Gender relations have become a key dimension in family studies, and understanding gender relations as both determining and resulting from outcome of new family configurations requires the use of specific surveys aimed at the dynamics of couples. Unfortunately, nationally representative surveys of this type are not available for Latin American countries. Nonetheless, the most recent versions of the Demographic and Health Surveys (DHS include a section called "Women's Status and Empowerment", which can provide information about gender relations as well. This study aims at assessing the construct of gender relations in terms of couples' joint decision-making for all five Brazilian geographical regions. To this end, a step-by-step multi-group confirmatory factor analysis (MGCFA was applied in order to verify whether this concept can be compared across Brazilian regions. Results show that the DHS items can be used reliably for measuring couples' joint decision-making and that this construct can be meaningfully compared over the regions. These findings will contribute to further demographic and sociological research on gender relations which can use this concept and other indicators provided by the DHS to identify the causal processes related to it.

  15. Case-finding for common mental disorders of anxiety and depression in primary care: an external validation of routinely collected data.

    Science.gov (United States)

    John, Ann; McGregor, Joanne; Fone, David; Dunstan, Frank; Cornish, Rosie; Lyons, Ronan A; Lloyd, Keith R

    2016-03-15

    The robustness of epidemiological research using routinely collected primary care electronic data to support policy and practice for common mental disorders (CMD) anxiety and depression would be greatly enhanced by appropriate validation of diagnostic codes and algorithms for data extraction. We aimed to create a robust research platform for CMD using population-based, routinely collected primary care electronic data. We developed a set of Read code lists (diagnosis, symptoms, treatments) for the identification of anxiety and depression in the General Practice Database (GPD) within the Secure Anonymised Information Linkage Databank at Swansea University, and assessed 12 algorithms for Read codes to define cases according to various criteria. Annual incidence rates were calculated per 1000 person years at risk (PYAR) to assess recording practice for these CMD between January 1(st) 2000 and December 31(st) 2009. We anonymously linked the 2799 MHI-5 Caerphilly Health and Social Needs Survey (CHSNS) respondents aged 18 to 74 years to their routinely collected GP data in SAIL. We estimated the sensitivity, specificity and positive predictive value of the various algorithms using the MHI-5 as the gold standard. The incidence of combined depression/anxiety diagnoses remained stable over the ten-year period in a population of over 500,000 but symptoms increased from 6.5 to 20.7 per 1000 PYAR. A 'historical' GP diagnosis for depression/anxiety currently treated plus a current diagnosis (treated or untreated) resulted in a specificity of 0.96, sensitivity 0.29 and PPV 0.76. Adding current symptom codes improved sensitivity (0.32) with a marginal effect on specificity (0.95) and PPV (0.74). We have developed an algorithm with a high specificity and PPV of detecting cases of anxiety and depression from routine GP data that incorporates symptom codes to reflect GP coding behaviour. We have demonstrated that using diagnosis and current treatment alone to identify cases for

  16. Automated External Defibrillator

    Science.gov (United States)

    ... To Health Topics / Automated External Defibrillator Automated External Defibrillator Also known as What Is An automated external ... in survival. Training To Use an Automated External Defibrillator Learning how to use an AED and taking ...

  17. Performance of Multiple Risk Assessment Tools to Predict Mortality for Adult Respiratory Distress Syndrome with Extracorporeal Membrane Oxygenation Therapy: An External Validation Study Based on Chinese Single-center Data.

    Science.gov (United States)

    Huang, Lei; Li, Tong; Xu, Lei; Hu, Xiao-Min; Duan, Da-Wei; Li, Zhi-Bo; Gao, Xin-Jing; Li, Jun; Wu, Peng; Liu, Ying-Wu; Wang, Song; Lang, Yu-Heng

    2016-07-20

    There has been no external validation of survival prediction models for severe adult respiratory distress syndrome (ARDS) with extracorporeal membrane oxygenation (ECMO) therapy in China. The aim of study was to compare the performance of multiple models recently developed for patients with ARDS undergoing ECMO based on Chinese single-center data. A retrospective case study was performed, including twenty-three severe ARDS patients who received ECMO from January 2009 to July 2015. The PRESERVE (Predicting death for severe ARDS on VV-ECMO), ECMOnet, Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP) score, a center-specific model developed for inter-hospital transfers receiving ECMO, and the classical risk-prediction scores of Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) were calculated. In-hospital and six-month mortality were regarded as the endpoints and model performance was evaluated by comparing the area under the receiver operating characteristic curve (AUC). The RESP and APACHE II scores showed excellent discriminate performance in predicting survival with AUC of 0.835 (95% confidence interval [CI], 0.659-1.010, P = 0.007) and 0.762 (95% CI, 0.558-0.965, P = 0.035), respectively. The optimal cutoff values were risk class 3.5 for RESP and 35.5 for APACHE II score, and both showed 70.0% sensitivity and 84.6% specificity. The excellent performance of these models was also evident for the pneumonia etiological subgroup, for which the SOFA score was also shown to be predictive, with an AUC of 0.790 (95% CI, 0.571-1.009, P = 0.038). However, the ECMOnet and the score developed for externally retrieved ECMO patients failed to demonstrate significant discriminate power for the overall cohort. The PRESERVE model was unable to be evaluated fully since only one patient died six months postdischarge. The RESP, APCHAE II, and SOFA scorings systems show good predictive value for intra

  18. Mirroring everyday clinical practice in clinical trial design: a new concept to improve the external validity of randomized double-blind placebo-controlled trials in the pharmacological treatment of major depression

    Directory of Open Access Journals (Sweden)

    Severus Emanuel

    2012-07-01

    Full Text Available Abstract Background Randomized, double-blind, placebo-controlled trials constitute the gold standard in clinical research when testing the efficacy of new psychopharmacological interventions in the treatment of major depression. However, the blinded use of placebo has been found to influence clinical trial outcomes and may bias patient selection. Discussion To improve clinical trial design in major depression so as to reflect clinical practice more closely we propose to present patients with a balanced view of the benefits of study participation irrespective of their assignment to placebo or active treatment. In addition every participant should be given the option to finally receive the active medication. A research agenda is outlined to evaluate the impact of the proposed changes on the efficacy of the drug to be evaluated and on the demographic and clinical characteristics of the enrollment fraction with regard to its representativeness of the eligible population. Summary We propose a list of measures to be taken to improve the external validity of double-blind, placebo-controlled trials in major depression. The recommended changes to clinical trial design may also be relevant for other psychiatric as well as medical disorders in which expectations regarding treatment outcome may affect the outcome itself.

  19. Delirium risk stratification in consecutive unselected admissions to acute medicine: validation of a susceptibility score based on factors identified externally in pooled data for use at entry to the acute care pathway.

    Science.gov (United States)

    Pendlebury, Sarah T; Lovett, Nicola G; Smith, Sarah C; Wharton, Rose; Rothwell, Peter M

    2017-03-01

    recognition of prevalent delirium and prediction of incident delirium may be difficult at first assessment. We therefore aimed to validate a pragmatic delirium susceptibility (for any, prevalent and incident delirium) score for use in front-line clinical practice in a consecutive cohort of older acute medicine patients. consecutive patients aged ≥65 years over two 8-week periods (2010-12) were screened prospectively for delirium using the Confusion Assessment Method (CAM), and delirium was diagnosed using the DSM IV criteria. The delirium susceptibility score was the sum of weighted risk factors derived using pooled data from UK-NICE guidelines: age >80 = 2, cognitive impairment (cognitive score below cut-off/dementia) = 2, severe illness (systemic inflammatory response syndrome) = 1, infection = 1, visual impairment = 1. Score reliability was determined by the area under the receiver operating curve (AUC). among 308 consecutive patients aged ≥65 years (mean age/SD = 81/8 years, 164 (54%) female), AUC was 0.78 (95% CI 0.71-0.84) for any delirium; 0.71 (0.64-0.79), for prevalent delirium; 0.81 (0.70-0.92), for incident delirium; odds ratios (ORs) for risk score 5-7 versus delirium, 8.1 (2.2-29.7), P = 0.002 for prevalent delirium, and 25.0 (3.0-208.9) P = 0.003 for incident delirium, with corresponding relative risks of 5.4, 4.7 and 13. Higher risk scores were associated with frailty markers, increased care needs and poor outcomes. the externally derived delirium susceptibility score reliably identified prevalent and incident delirium using clinical data routinely available at initial patient assessment and might therefore aid recognition of vulnerability in acute medical admissions early in the acute care pathway. © The Author 2016. Published by Oxford University Press on behalf of the British Geriatrics Society.

  20. 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.

  1. 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.)

  2. 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.)

  3. 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...

  4. The External Nasal Valve.

    Science.gov (United States)

    Hamilton, Grant S

    2017-05-01

    The external nasal valve is a complex entity comprised of multiple structures and tissue types. As such, there is no single operation that can address all problems of the external valve. This article reviews the relevant anatomy, pathologic conditions, and treatments for external nasal valve dysfunction, including a detailed review of the nasal muscles and their contribution to external nasal valve patency. Surgical and nonsurgical options for treatment and the evidence supporting the importance of proper external nasal valve function on quality-of-life measures are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. 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

  6. 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

  7. Validation and understanding of Moderate Resolution Imaging Spectroradiometer aerosol products (C5) using ground-based measurements from the handheld Sun photometer network in China

    Science.gov (United States)

    Zhanqing Li; Feng Niu; Kwon-Ho Lee; Jinyuan Xin; Wei Min Hao; Bryce L. Nordgren; Yuesi Wang; Pucai Wang

    2007-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) currently provides the most extensive aerosol retrievals on a global basis, but validation is limited to a small number of ground stations. This study presents a comprehensive evaluation of Collection 4 and 5 MODIS aerosol products using ground measurements from the Chinese Sun Hazemeter Network (CSHNET). The...

  8. Using the risk behaviour diagnosis scale to understand Australian Aboriginal smoking — A cross-sectional validation survey in regional New South Wales

    Directory of Open Access Journals (Sweden)

    Gillian Sandra Gould

    2015-01-01

    Conclusions: In these Aboriginal smokers of reproductive age, the RBD Scale appeared valid and reliable. Further research is required to assess whether the RBD Scale and EPPM can predict quit attempts and assist with tailored approaches to counselling and targeted health promotion campaigns.

  9. The Development and Validation of a Three-Tier Diagnostic Test Measuring Pre-Service Elementary Education and Secondary Science Teachers' Understanding of the Water Cycle

    Science.gov (United States)

    Schaffer, Dannah Lynn

    2013-01-01

    The main goal of this research study was to develop and validate a three-tier diagnostic test to determine pre-service teachers' (PSTs) conceptual knowledge of the water cycle. For a three-tier diagnostic test, the first tier assesses content knowledge; in the second tier, a reason is selected for the content answer; and the third tier allows…

  10. Teaching Teaching & Understanding Understanding

    DEFF Research Database (Denmark)

    2006-01-01

    "Teaching Teaching & Understanding Understanding" is a 19-minute award-winning short-film about teaching at university and higher-level educational institutions. It is based on the "Constructive Alignment" theory developed by Prof. John Biggs. The film delivers a foundation for understanding what...

  11. Automated external defibrillators: design considerations.

    Science.gov (United States)

    Kroll, M W; Brewer, J E

    1997-05-01

    Biphasic defibrillation waveforms are now the standard of care in clinical use for defibrillation with implantable cardioverter-defibrillators (ICDs), due to the superior performance demonstrated over that of comparable monophasic waveforms. To better understand these significantly different outcomes, ICD research has developed cardiac cell response models to defibrillation. Waveform design criteria have been derived from these first principles and have been applied to monophasic and biphasic waveforms to optimize their parameters. These principles-based design criteria have produced significant improvements over the current art of waveforms. Monophasic defibrillation waveforms remain the standard of care in clinical use for transthoracic defibrillation. Waveform design has not yet been influenced by the important gains made in ICD research. The limitations of present transthoracic waveforms may be due in part to a lack of application of these design principles to determine optimal waveform characteristics. To overcome these limitations, design principles based on cell response have recently been developed for external defibrillation waveforms. The transthoracic model incorporates elements into a cell response model that extends it to external defibrillation. External waveform design principles demonstrate reductions in capacitance, voltage, duration, and delivered energy. Therefore, design principles based on cardiac electrophysiology may provide a means to significantly reduce the energy required for safe and efficacious external defibrillation. Footnotes, formulae, and figures augment this presentation in order to clarify the defibrillation waveform theory.

  12. 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

  13. 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"....

  14. 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...... instruments. However, solving the open-access externality problem also affects CO2 emissions. By using a bio-economic model covering Iceland, Norway, Denmark, Sweden, and the Faroe Islands, it is shown that regulations of the open-access externality problem have a large effect on both economic performance...... and CO2 emissions, while an additional CO2 regulation only has minor effects. The second-best solution achieved by only regulating open access reduces emissions by approximately 50% compared to current fisheries, with the exception of Iceland, which already has a well-developed fisheries management...

  15. Validation of the CPAP Habit Index-5: A Tool to Understand Adherence to CPAP Treatment in Patients with Obstructive Sleep Apnea

    OpenAIRE

    Broström, Anders; Nilsen, Per; Gardner, Benjamin; Johansson, Peter; Ulander, Martin; Fridlund, Bengt; Årestedt, Kristofer

    2014-01-01

    Long-term adherence to continuous positive airway pressure (CPAP) is low among patients with obstructive sleep apnea (OSA). The potential role of "habit" in sustaining adherence to CPAP use has not been studied. This study aimed to establish the relevance of habit to CPAP adherence, via validation of an adaptation of the Self-Report Habit Index (the CPAP Habit Index-5; CHI-5). Analyses focused on the homogeneity, reliability, and factor structure of the CHI-5 and, in line with theoretical pre...

  16. Imitation and Action Understanding in Autistic Spectrum Disorders: How Valid Is the Hypothesis of a Deficit in the Mirror Neuron System?

    Science.gov (United States)

    Hamilton, Antonia F. de C.; Brindley, Rachel M.; Frith, Uta

    2007-01-01

    The motor mirror neuron system supports imitation and goal understanding in typical adults. Recently, it has been proposed that a deficit in this mirror neuron system might contribute to poor imitation performance in children with autistic spectrum disorders (ASD) and might be a cause of poor social abilities in these children. We aimed to test…

  17. [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.

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

    Science.gov (United States)

    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.

  19. Northern Territory perspectives on heart failure with comorbidities – understanding trial validity and exploring collaborative opportunities to broaden the evidence base.

    Science.gov (United States)

    Iyngkaran, P; Majoni, W; Cass, A; Sanders, Prashanthan; Ronco, C; Brady, S; Kangaharan, N; Ilton, M; Hare, D L; Thomas, M C

    2015-06-01

    Congestive Heart Failure (CHF) is an ambulatory care sensitive condition, associated with significant morbidity and mortality, rarely with cure. Outpatient based pharmacological management represents the main and most important aspect of care, and is usually lifelong. This narrative styled opinion review looks at the pharmacological agents recommended in the guidelines in context of the Northern Territory (NT) of Australia. We explore the concept of validity, a term used to describe the basis of standardising a particular trial or study and the population to which it is applicable. We aim to highlight the problems of the current guidelines based approach. We also present alternatives that could utilise the core principles from major trials, while incorporating regional considerations, which could benefit clients living in the NT and remote Australia. Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  20. Understanding latent structures of clinical information logistics: A bottom-up approach for model building and validating the workflow composite score.

    Science.gov (United States)

    Esdar, Moritz; Hübner, Ursula; Liebe, Jan-David; Hüsers, Jens; Thye, Johannes

    2017-01-01

    Clinical information logistics is a construct that aims to describe and explain various phenomena of information provision to drive clinical processes. It can be measured by the workflow composite score, an aggregated indicator of the degree of IT support in clinical processes. This study primarily aimed to investigate the yet unknown empirical patterns constituting this construct. The second goal was to derive a data-driven weighting scheme for the constituents of the workflow composite score and to contrast this scheme with a literature based, top-down procedure. This approach should finally test the validity and robustness of the workflow composite score. Based on secondary data from 183 German hospitals, a tiered factor analytic approach (confirmatory and subsequent exploratory factor analysis) was pursued. A weighting scheme, which was based on factor loadings obtained in the analyses, was put into practice. We were able to identify five statistically significant factors of clinical information logistics that accounted for 63% of the overall variance. These factors were "flow of data and information", "mobility", "clinical decision support and patient safety", "electronic patient record" and "integration and distribution". The system of weights derived from the factor loadings resulted in values for the workflow composite score that differed only slightly from the score values that had been previously published based on a top-down approach. Our findings give insight into the internal composition of clinical information logistics both in terms of factors and weights. They also allowed us to propose a coherent model of clinical information logistics from a technical perspective that joins empirical findings with theoretical knowledge. Despite the new scheme of weights applied to the calculation of the workflow composite score, the score behaved robustly, which is yet another hint of its validity and therefore its usefulness. Copyright © 2016 Elsevier Ireland

  1. Initial external events: floods

    International Nuclear Information System (INIS)

    Drumond, M.M.

    1989-12-01

    The initial external event, specifically flood in a Nuclear power plant, and the calculation necessary to determine the contribution of this type of event in a Probabilistic Safety Analysis, are presented. (M.I.)

  2. 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)

  3. 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.

  4. Future of External Reporting

    Science.gov (United States)

    Powers, Kristina

    2015-01-01

    This chapter builds on prior chapters and focuses on higher education trends on the horizon and the resulting impact on external reporting for institutional researchers. Three practical recommendations and examples for institutional researchers are also presented.

  5. Performance of Multiple Risk Assessment Tools to Predict Mortality for Adult Respiratory Distress Syndrome with Extracorporeal Membrane Oxygenation Therapy: An External Validation Study Based on Chinese Single-center Data

    Directory of Open Access Journals (Sweden)

    Lei Huang

    2016-01-01

    Conclusions: The RESP, APCHAE II, and SOFA scorings systems show good predictive value for intra-hospital survival of ARDS patients treated with ECMO in our single-center evaluation. Future validation should include a larger study with either more patients' data at single-center or by integration of domestic multi-center data. Development of a scoring system with national characteristics might be warranted.

  6. Validation of the CPAP Habit Index-5: A Tool to Understand Adherence to CPAP Treatment in Patients with Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Anders Broström

    2014-01-01

    Full Text Available Long-term adherence to continuous positive airway pressure (CPAP is low among patients with obstructive sleep apnea (OSA. The potential role of “habit” in sustaining adherence to CPAP use has not been studied. This study aimed to establish the relevance of habit to CPAP adherence, via validation of an adaptation of the Self-Report Habit Index (the CPAP Habit Index-5; CHI-5. Analyses focused on the homogeneity, reliability, and factor structure of the CHI-5 and, in line with theoretical predictions, its utility as a predictor of long-term CPAP adherence in middle-aged patients with OSA. A prospective longitudinal design was used. 117 patients with objectively verified OSA intended for CPAP treatment were recruited. Data was collected via clinical examinations, respiratory recordings, questionnaires, and CPAP devices at baseline, 2 weeks, 6 months, and 12 months. The CHI-5 showed satisfactory homogeneity interitem correlations (0.42–0.93, item-total correlations (0.58–0.91, and reliability (α = 0.92. CHI-5 data at 6 months showed a one-factor solution and predicted 63% of variance in total CPAP use hours after 12 months. Based on the satisfactory measurement properties and the high amount of CPAP use variance it explained, the CHI-5 can be seen as a useful tool in clinical practice.

  7. Validation of the D'amico risk groups classification, valuation of high-risk patients with or without hormonal therapy and complications of patients with adenocarcinoma of the prostate, after treatment with external radiotherapy, Hospital Calderon Guardia, 2003-2004

    International Nuclear Information System (INIS)

    Lopez Arias, Ever Roy

    2008-01-01

    D'amico risk groups have been classified to estimate the probability of biochemical recurrence after treatment for localized prostate cancer. The evolution of patients that have received external radiotherapy were analyzed according to the risk group. The medical records of 50 patients between 2003 and 2004 have been assessed and has observed the evolution of Prostatic Specific Antigen after treatment ends, at Hospital Calderon Guardia. Adverse reactions resulting from radiotherapy treatment and the organs most affected by the same have been documented nith the possibility to compare the results of similar studies in the literature. The best performance is given by receiving concomitant hormonal therapy that high risk patients of D'amico without receiving. (author) [es

  8. an external control unit implemented for stimulator asic

    African Journals Online (AJOL)

    pc

    2017-11-10

    Nov 10, 2017 ... external control of supply voltage adaptation validate the functionality of the designed ECU and the stimulator ASIC. ... Keywords: external control unit; data transceiver; stimulator ASIC; retinal prosthesis; epiretinal implant ...... using MATLAB Simulink and Arduino microcontroller. Journal of Applied ...

  9. How Health Professionals Conceptualize and Represent Placebo Treatment in Clinical Trials and How Their Patients Understand It: Impact on Validity of Informed Consent

    Science.gov (United States)

    Keller, Pascal-Henri; Grondin, Olivier; Tison, François; Gonon, Francois

    2016-01-01

    Context Previous studies suggested that many patients, who have given their informed consent to participate in randomized controlled trials (RCT), have somewhat limited understanding of what a placebo treatment is. We hypothesized that the relationship between patients and their health professionals plays a central role in this understanding. Methods We interviewed 12 patients included in RCTs (nine suffering from Parkinson’s disease and three from Huntington’s disease) and 18 health professionals involved with RCTs (eight principal investigators, four associated physicians and six clinical research associates). Semi-structured interviews were conducted after the RCTs had ended but before the treatment allocation was revealed. Results Only two patients clearly understood the aim of placebo-controlled RCTs. Only one principal investigator said she asks all her patients whether they agree to participate in RCTs. The seven others said they only ask patients who seem more likely to be compliant. Their selection criteria included docility and personality traits associated in other studies with enhanced placebo responses. According to 13 of the 18 health professionals, their relationship with patients may influence the amplitude of the placebo response. All but one clinical research associates added that the placebo response could result from a “maternal” type of care. All principal investigators said they have a strong influence on their patient's decision to participate. Finally, when interviewees were asked to narrate a memory of a medically unexplained healing, in eight of 11 physicians' narratives the beneficiary was a child while in 10 of 12 patients' narratives it was an adult. Conclusion Our observations suggest that the interrelationship between health professionals and patients involved in RCTs could be compared to that between parents and children. Therefore, adherence to formal rules regarding informed consent does not ensure a balanced relationship

  10. Seven-day mortality can be predicted in medical patients by blood pressure, age, respiratory rate, loss of independence, and peripheral oxygen saturation (the PARIS score: a prospective cohort study with external validation.

    Directory of Open Access Journals (Sweden)

    Mikkel Brabrand

    Full Text Available Most existing risk stratification systems predicting mortality in emergency departments or admission units are complex in clinical use or have not been validated to a level where use is considered appropriate. We aimed to develop and validate a simple system that predicts seven-day mortality of acutely admitted medical patients using routinely collected variables obtained within the first minutes after arrival.This observational prospective cohort study used three independent cohorts at the medical admission units at a regional teaching hospital and a tertiary university hospital and included all adult (≥ 15 years patients. Multivariable logistic regression analysis was used to identify the clinical variables that best predicted the endpoint. From this, we developed a simplified model that can be calculated without specialized tools or loss of predictive ability. The outcome was defined as seven-day all-cause mortality. 76 patients (2.5% met the endpoint in the development cohort, 57 (2.0% in the first validation cohort, and 111 (4.3% in the second. Systolic blood Pressure, Age, Respiratory rate, loss of Independence, and peripheral oxygen Saturation were associated with the endpoint (full model. Based on this, we developed a simple score (range 0-5, ie, the PARIS score, by dichotomizing the variables. The ability to identify patients at increased risk (discriminatory power and calibration was excellent for all three cohorts using both models. For patients with a PARIS score ≥ 3, sensitivity was 62.5-74.0%, specificity 85.9-91.1%, positive predictive value 11.2-17.5%, and negative predictive value 98.3-99.3%. Patients with a score ≤ 1 had a low mortality (≤ 1%; with 2, intermediate mortality (2-5%; and ≥ 3, high mortality (≥ 10%.Seven-day mortality can be predicted upon admission with high sensitivity and specificity and excellent negative predictive values.

  11. Productivity Change and Externalities

    DEFF Research Database (Denmark)

    Kravtsova, Victoria

    2014-01-01

    This paper contributes to the analysis of the impact of externalities on the host country's total factor productivity by taking into account different dimensions of spillover effects. Namely, engagement in exporting and foreign ownership is generally perceived as being beneficial to individual...... firms and the economy as a whole. The approach used in the current research accounts for different internal as well as external factors that individual firms face and evaluates the effect on changes in productivity, technology as well as the efficiency of domestic firms. The empirical analysis focuses...... on Hungary. While the country leads the group of post-socialist countries in the amount of attracted foreign direct investments (FDI) the effect of this policy on the economy remains unclear. The research finds that different externalities play a different role in productivity, technological and efficiency...

  12. Externality or sustainability economics?

    International Nuclear Information System (INIS)

    Bergh, Jeroen C.J.M. van den

    2010-01-01

    In an effort to develop 'sustainability economics' Baumgaertner and Quaas (2010) neglect the central concept of environmental economics-'environmental externality'. This note proposes a possible connection between the concepts of environmental externality and sustainability. In addition, attention is asked for other aspects of 'sustainability economics', namely the distinction weak/strong sustainability, spatial sustainability and sustainable trade, distinctive sustainability policy, and the ideas of early 'sustainability economists'. I argue that both sustainability and externalities reflect a systems perspective and propose that effective sustainability solutions require that more attention is given to system feedbacks, notably other-regarding preferences and social interactions, and energy and environmental rebound. The case of climate change and policy is used to illustrate particular statements. As a conclusion, a list of 20 insights and suggestions for research is offered. (author)

  13. External validation of the fatty liver index and lipid accumulation product indices, using 1H-magnetic resonance spectroscopy, to identify hepatic steatosis in healthy controls and obese, insulin-resistant individuals.

    Science.gov (United States)

    Cuthbertson, Daniel J; Weickert, Martin O; Lythgoe, Daniel; Sprung, Victoria S; Dobson, Rebecca; Shoajee-Moradie, Fariba; Umpleby, Margot; Pfeiffer, Andreas F H; Thomas, E Louise; Bell, Jimmy D; Jones, Helen; Kemp, Graham J

    2014-11-01

    Simple clinical algorithms including the fatty liver index (FLI) and lipid accumulation product (LAP) have been developed as surrogate markers for non-alcoholic fatty liver disease (NAFLD), constructed using (semi-quantitative) ultrasonography. This study aimed to validate FLI and LAP as measures of hepatic steatosis, as determined quantitatively by proton magnetic resonance spectroscopy (1H-MRS). Data were collected from 168 patients with NAFLD and 168 controls who had undergone clinical, biochemical and anthropometric assessment. Values of FLI and LAP were determined and assessed both as predictors of the presence of hepatic steatosis (liver fat>5.5%) and of actual liver fat content, as measured by 1H-MRS. The discriminative ability of FLI and LAP was estimated using the area under the receiver operator characteristic curve (AUROC). As FLI can also be interpreted as a predictive probability of hepatic steatosis, we assessed how well calibrated it was in our cohort. Linear regression with prediction intervals was used to assess the ability of FLI and LAP to predict liver fat content. Further validation was provided in 54 patients with type 2 diabetes mellitus. FLI, LAP and alanine transferase discriminated between patients with and without steatosis with an AUROC of 0.79 (IQR=0.74, 0.84), 0.78 (IQR=0.72, 0.83) and 0.83 (IQR=0.79, 0.88) respectively although could not quantitatively predict liver fat. Additionally, the algorithms accurately matched the observed percentages of patients with hepatic steatosis in our cohort. FLI and LAP may be used to identify patients with hepatic steatosis clinically or for research purposes but could not predict liver fat content. © 2014 European Society of Endocrinology.

  14. External costs of electricity

    International Nuclear Information System (INIS)

    Rabl, A.; Spadaro, J.V.

    2005-01-01

    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.)

  15. On parabolic external maps

    DEFF Research Database (Denmark)

    Lomonaco, Luna; Petersen, Carsten Lunde; Shen, Weixiao

    2017-01-01

    We prove that any C1+BV degree d ≥ 2 circle covering h having all periodic orbits weakly expanding, is conjugate by a C1+BV diffeomorphism to a metrically expanding map. We use this to connect the space of parabolic external maps (coming from the theory of parabolic-like maps) to metrically expan...

  16. Network cities and externalities

    Directory of Open Access Journals (Sweden)

    Rafael Boix Domènech

    2004-01-01

    Full Text Available The concept of «agglomeration economies» explains the existence of advantages derived from the concentration of population and activity. However, it does not explain the existence of spatially dynamic external economies. Network economies generated in networks of cities correspond to this last type, since they are generated from the interaction between urban units, linked by a network relationship. The objective of this research is to advance in the study of the relationship between the networks of cities and the generation of external economies. The research is divided in four parts: first we expose the link between networks of cities and external economies. The second part outlines a model for the combined measuring of the concentration and network economies. The third part explains the results of applying the model to a case of study: the network of cities of Catalonia. The results suggest that there is a causal relationship between the organization of the urban units forming networks of cities and the generation of external economies that affect growth and economic development. Finally, conclusions and policy implications are drawn up.

  17. External Otitis (Swimmer's Ear)

    Science.gov (United States)

    ... an otoscope for redness, swelling, and pus. Debris removal, antibiotic ear drops, keeping water out of the ear, and pain relievers are ... cleaning it (using cotton-tipped swabs) or getting water or irritants, such as hair spray or hair dye, in the canal often leads to external otitis. ...

  18. The External Mind

    DEFF Research Database (Denmark)

    The External Mind: an Introduction by Riccardo Fusaroli, Claudio Paolucci pp. 3-31 The sign of the Hand: Symbolic Practices and the Extended Mind by Massimiliano Cappuccio, Michael Wheeler pp. 33-55 The Overextended Mind by Shaun Gallagher pp. 57-68 The "External Mind": Semiotics, Pragmatism......, Extended Mind and Distributed Cognition by Claudio Paolucci pp. 69-96 The Social Horizon of Embodied Language and Material Symbols by Riccardo Fusaroli pp. 97-123 Semiotics and Theories of Situated/Distributed Action and Cognition: a Dialogue and Many Intersections by Tommaso Granelli pp. 125-167 Building...... Action in Public Environments with Diverse Semiotic Resources by Charles Goodwin pp. 169-182 How Marking in Dance Constitutes Thinking with the Body by David Kirsh pp. 183-214 Ambiguous Coordination: Collaboration in Informal Science Education Research by Ivan Rosero, Robert Lecusay, Michael Cole pp. 215-240...

  19. Externally triggered microcapsules

    Science.gov (United States)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2011-01-01

    Disclosed are microcapsules comprising a polymer shell enclosing one or more immiscible liquid phases in which a drug or drug precursor are contained in a liquid phase. The microparticles also contain magnetic particles that can be heated by application of an external magnetic field and thus heated to a predetermined Curie temperature. Heating of the particles melts the polymer shell and releases the drug without causing heating of surrounding tissues.

  20. Beliefs about language development: construct validity evidence.

    Science.gov (United States)

    Donahue, Mavis L; Fu, Qiong; Smith, Everett V

    2012-01-01

    Understanding language development is incomplete without recognizing children's sociocultural environments, including adult beliefs about language development. Yet there is a need for data supporting valid inferences to assess these beliefs. The current study investigated the psychometric properties of data from a survey (MODeL) designed to explore beliefs in the popular culture, and their alignment with more formal theories. Support for the content, substantive, structural, generalizability, and external aspects of construct validity of the data were investigated. Subscales representing Behaviorist, Cognitive, Nativist, and Sociolinguistic models were identified as dimensions of beliefs. More than half of the items showed a high degree of consensus, suggesting culturally-transmitted beliefs. Behaviorist ideas were most popular. Bilingualism and ethnicity were related to Cognitive and Sociolinguistic beliefs. Identifying these beliefs may clarify the nature of child-directed speech, and enable the design of language intervention programs that are congruent with family and cultural expectations.

  1. 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…

  2. External split field generator

    Science.gov (United States)

    Thundat, Thomas George [Knoxville, TN; Van Neste, Charles W [Kingston, TN; Vass, Arpad Alexander [Oak Ridge, TN

    2012-02-21

    A generator includes a coil disposed about a core. A first stationary magnetic field source may be disposed on a first end portion of the core and a second stationary magnetic field source may be disposed on a second end portion of core. The first and second stationary magnetic field sources apply a stationary magnetic field to the coil. An external magnetic field source may be disposed outside the coil to apply a moving magnetic field to the coil. Electrical energy is generated in response to an interaction between the coil, the moving magnetic field, and the stationary magnetic field.

  3. 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...

  4. 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

  5. External quality assessment: best practice.

    Science.gov (United States)

    James, David; Ames, Darren; Lopez, Berenice; Still, Rachel; Simpson, Wiliam; Twomey, Patrick

    2014-08-01

    There is a requirement for accredited laboratories to participate in external quality assessment (EQA) schemes, but there is wide variation in understanding as to what is required by the laboratories and scheme providers in fulfilling this. This is not helped by a diversity of language used in connection with EQA; Proficiency testing (PT), EQA schemes, and EQA programmes, each of which have different meanings and offerings in the context of improving laboratory quality. We examine these differences, and identify what factors are important in supporting quality within a clinical laboratory and what should influence the choice of EQA programme. Equally as important is how EQA samples are handled within the laboratory, and how the information provided by the EQA programme is used. EQA programmes are a key element of a laboratory's quality assurance framework, but laboratories should have an understanding of what their EQA programmes are capable of demonstrating, how they should be used within the laboratory, and how they support quality. EQA providers should be clear as to what type of programme they provide - PT, EQA Scheme or EQA Programme. 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.

  6. Validade de construto da versão brasileira do Inventário Espectral de Externalização: evidências a partir de uma amostra de estudantes universitários Construct validity of the Brazilian version of the Externalizing Spectrum Inventory: evidence from a university student sample

    Directory of Open Access Journals (Sweden)

    Hudson Wander de Carvalho

    2010-01-01

    Full Text Available CONTEXTO: Externalização é uma dimensão das diferenças individuais que dá substrato e unifica traços impulsivos e agressivos de personalidade a transtornos mentais relacionados ao uso de substância e à conduta antissocial. OBJETIVOS: O presente estudo objetivou apresentar indicadores de validade de construto da versão brasileira do Inventário Espectral de Externalização. MÉTODO: Trata-se de um estudo psicométrico de orientação correlacional. Foram utilizadas duas técnicas clássicas de representação de construto: análise exploratória de fatores comuns e análise de consistência interna. A amostra consistiu de 258 participantes de ambos os sexos, provenientes de diferentes cursos universitários de duas instituições públicas do estado de Minas Gerais. RESULTADOS: A análise fatorial resultou em um modelo de um fator de segunda ordem (Externalização com três fatores de primeira ordem (dimensões de agressão, de uso de substância e de impulsividade/alienação. Os coeficientes alfa mostraram-se bastante elevados, com índices acima de 0,9 tanto para os três fatores de primeira ordem quanto para o fator geral. CONCLUSÃO: Combinados, os resultados trazem evidências de validade e de fidedignidade para a versão brasileira do Inventário Espectral de Externalização no que tange à sua aplicabilidade a estudantes universitários.BACKGROUND: Externalizing is a dimension of individual differences that undergirds and unites aggressive and impulsive personality traits to psychopathological disorders related to substance use and antisocial behavior. OBJECTIVES: The present study aims to establish parameters of construct validity for the Brazilian version of the Externalizing Spectrum Inventory. METHOD: This is a psychometrical correlacional study design. Two classical techniques of construct representation were implemented: unweighted least squares exploratory factor analysis and internal consistency analysis. The sample

  7. 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.

  8. An SAT® Validity Primer

    Science.gov (United States)

    Shaw, Emily J.

    2015-01-01

    This primer should provide the reader with a deeper understanding of the concept of test validity and will present the recent available validity evidence on the relationship between SAT® scores and important college outcomes. In addition, the content examined on the SAT will be discussed as well as the fundamental attention paid to the fairness of…

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Identifying and Evaluating External Validity Evidence for Passing Scores

    Science.gov (United States)

    Davis-Becker, Susan L.; Buckendahl, Chad W.

    2013-01-01

    A critical component of the standard setting process is collecting evidence to evaluate the recommended cut scores and their use for making decisions and classifying students based on test performance. Kane (1994, 2001) proposed a framework by which practitioners can identify and evaluate evidence of the results of the standard setting from (1)…

  11. An external construct validity study of Rorschach personality variables.

    Science.gov (United States)

    Greenwald, D F

    1990-01-01

    This study examined (a) hypothesized relationships between Rorschach variables and self-report test measures relating to nominally similar aspects of personality functioning and (b) interrelationships among Rorschach variables. Sixty-two undergraduates were administered the Rorschach, Barron Ego Strength Scale, Kaplan Self-Derogation Scale, Eagly Self-Esteem Scale, Multiple Affective Adjective Checklist (MAACL), Marlowe-Crowne Social Desirability Scale, and the Rotter Locus of Control Scale. Only a few of the predictions received confirmation: inanimate movement (m) correlated, as expected, with MAACL anxiety and hostility, the egocentricity index (3r + 2)/R (R = total responses) correlated significantly with self-esteem, and human movement with minus form level (M-) correlated (inversely) with ego strength. Among the unpredicted findings were some that appear inconsistent with standard Rorschach interpretation. Rorschach variables human movement (M), and experience actual (EA), generally interpreted as reflecting coping resources, related significantly with self-report measures of poor coping and of dysphoric affect. In general, the Rorschach appears better at identifying weaknesses in the ego rather than strengths.

  12. External validation and modification of a pediatric trauma triage tool.

    Science.gov (United States)

    Nasr, Ahmed; Mikrogianakis, Angelo; McDowall, Dorothy; Wales, Paul

    2007-03-01

    Simon et al. developed a simple secondary triage tool (mPTS) based on physiologic parameters and physical findings to identify pediatric trauma patients who had a low likelihood of serious injury. Such patients could be treated in the emergency room without full trauma team activation. Our objective was to evaluate the mPTS on the trauma population at our institution, a Level I pediatric trauma center. This was a retrospective cohort study of all trauma team activations at The Hospital for Sick Children (Sick Kids) (1999-2002), excluding penetrating trauma and burns. Patients were stratified into high-risk (Injury Severity Score [ISS] >or=12) and low-risk (ISS mPTS evaluates airway integrity, open wounds, neurologic status, hemodynamics, and skeletal integrity and applies a score of 1 point to each criterion. There were 628 trauma patients (382 boys, mean age of 8 +/- 3.8 years). The mPTS had a sensitivity of 92% and a positive predictive value (PPV) of 47% when applied to our population. The mPTS missed 21 patients with significant injuries, many were intra-abdominal. We modified the mPTS to include contusions to head and/or torso and a history of loss of consciousness and a 7-point score was developed. After modification the sensitivity was 99%, specificity 21%, and PPV of 46% with a 20% reduction in unnecessary trauma team activations. The original mPTS by Simon et al. was not sensitive enough when applied to our population. The Sick Kids modification to the score improved the sensitivity to 99%. The PPV of 46% indicates a safe level of overtriage is maintained. The Sick Kids mPTS remains easy to apply and would have reduced trauma team activation by 20%.

  13. Conceptual Elaboration Sequencing: An External Validation Study in Nursing Education

    Science.gov (United States)

    Kinderman, Kathy T.

    2012-01-01

    Nursing education is a knowledge domain that requires higher order thinking (critical thinking) for making decisions that impact outcomes of human health. The goal of nursing education is to develop novice experts in nursing knowledge and clinical practice. In order to achieve this goal, nursing education must employ instructional approaches that…

  14. External Validity: From Do-calculus to Transportability Across Populations

    Science.gov (United States)

    2012-05-01

    experiments with a different version. Their analysis is a special case of the theory developed in this paper (Petersen, 2011). A related application is...described below. 4 J. PEARL AND E. BAREINBOIM expected effect of a given intervention. Auxiliary to C, a causal model should also yield an estimand Qi(P...and used to confirm or disconfirm the model against the data. The structure of this inferential exercise is shown schematically in Figure 1. For a

  15. Different perspectives of validity in psychiatry.

    Science.gov (United States)

    Telles Correia, Diogo

    2017-10-01

    It is important to improve our understanding about what might be the specific characteristics of mental disorders to strengthen the scientific credibility of psychiatry and to clarify its position among other medical and nonmedical sciences. On the other hand, this issue has diagnostic, research, therapeutic, legal, financial, and moral implications. Some authors defend a realistic and absolutist attitude towards validity and others an instrumental and relativistic stance. Regarding the organization of concepts, dimensional or categorical approaches have both advantages and disadvantages. Regarding the methodology by which validity is sought, it can be oriented externally or internally to the concept in question. On the other hand, the validity can be expert driven or data driven, the research can be based on disorders or in symptoms and quantitative or qualitative methods may be used. In this article, we review all these different kinds of perspectives that can be taken towards the definition of validity in psychiatry and the methodology to search for it. © 2017 John Wiley & Sons, Ltd.

  16. 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

    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...... 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...... are identified, based on results of earlier studies and some identified of specific relevance for Denmark. Importance is attached to the quantification of impacts for each of the three fuel cycles and to monetisation of the externalities....

  17. Understanding Carbohydrates

    Science.gov (United States)

    ... Size: A A A Listen En Español Understanding Carbohydrates How much and what type of carbohydrate foods ... glucose levels in your target range. Explore: Understanding Carbohydrates Glycemic Index and Diabetes Learn about the glycemic ...

  18. Explicating Validity

    Science.gov (United States)

    Kane, Michael T.

    2016-01-01

    How we choose to use a term depends on what we want to do with it. If "validity" is to be used to support a score interpretation, validation would require an analysis of the plausibility of that interpretation. If validity is to be used to support score uses, validation would require an analysis of the appropriateness of the proposed…

  19. 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...... how the methodology has been applied so far in a previous Danish study. Finally, results of a case study are reported. Exposure factors have been calculated for various urban categories in the Greater Copenhagen Area...

  20. Retrofitting Systems for External Walls

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    In this report, 9 different external and internal retrofitting systems are analyzed using numerical calculations. The analysis focuses on the thermal bridge effects in the different systems, and on this basis it is discussed whether internal or external retrofitting has the most advantages. The d....... The different systems are evaluated using 5 different types of existing walls....

  1. External coating of colonic anastomoses

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Achiam, Michael Patrick; Rosenberg, Jacob

    2012-01-01

    Colon anastomotic leakage remains both a frequent and serious complication in gastrointestinal surgery. External coating of colonic anastomoses has been proposed as a means to lower the rate of this complication. The aim of this review was to evaluate existing studies on external coating of colonic...

  2. External benefits of natural environments

    Science.gov (United States)

    Larry W. Tombaugh

    1971-01-01

    Existing methods of assessing economic benefits arising from certain physical environments left in a relatively natural condition do not include estimates of external benefits. Existence value is one such external benefit that accrues to individuals who have no intention of ever visiting the area in question. A partial measure of the existence value of National Parks...

  3. External meeting: Geneva University

    CERN Multimedia

    2006-01-01

    ECOLE DE PHYSIQUE Département de physique nucléaire et corspusculaire 24, Quai Ernest-Ansermet1211 GENEVE 4 - Tél : 022 379 62 73 - Fax: 022 379 69 92 Wednesday 24 May 2006 PARTICLE PHYSICS SEMINAR at 17:00 - Stückelberg Auditorium Physics Performances of CMS by Dr Albert De Roeck / CERN An overview will be given of the physics capabilities of the CMS detector at the LHC. CMS is now completing its Physics Technical Design reports, summarizing the expected detector performance in a first volume and the physics reach with up to 30 fb-1 in the second volume. Results on the performance of the CMS detector as obtained from detailed simulations are presented for realistic operating conditions, and validated where possible against test beam and cosmic ray data. Procedures to measure the performance from early LHC data will be described. Finally, a selected number of results from new physics studies will be presented. Information: http://dpnc.unige.ch/seminaire/annonce.html Organizer : J.-S. Graulich

  4. External meeting: GENEVA UNIVERSITY

    CERN Multimedia

    2006-01-01

    ECOLE DE PHYSIQUE Département de physique nucléaire et corspusculaire 24, Quai Ernest-Ansermet1211 GENEVE 4 - Tél : 022 379 62 73 - Fax: 022 379 69 92 Wednesday 10 May 2006 PARTICLE PHYSICS SEMINARat 17:00 - Stückelberg Auditorium ZEUS: A detector for HERA by Andrée Robichaud-Véronneau / DPNC, Université de Genè ve HERA is the first lepton-proton collider in the world where a center of mass energy of 318 GeV is reached. Since 1992, the ZEUS detector is gating luminosity from it to probe QCD and look for exotic phenomena of fundamental particle physics. A history and overview of the detector and collider will be presented as well as important physics contributions made by the ZEUS experiment to the understanding of our world. Information: http://dpnc.unige.ch/seminaire/annonce.html Organizer : J.-S. Graulich

  5. Understanding classification

    NARCIS (Netherlands)

    Subianto, M.

    2009-01-01

    In practical data analysis, the understandability of models plays an important role in their acceptance. In the data mining literature, however, understandability plays is hardly ever mentioned. If it is mentioned, it is interpreted as meaning that the models have to be simple. In this thesis we

  6. Embodied understanding.

    Science.gov (United States)

    Johnson, Mark

    2015-01-01

    Western culture has inherited a view of understanding as an intellectual cognitive operation of grasping of concepts and their relations. However, cognitive science research has shown that this received intellectualist conception is substantially out of touch with how humans actually make and experience meaning. The view emerging from the mind sciences recognizes that understanding is profoundly embodied, insofar as our conceptualization and reasoning recruit sensory, motor, and affective patterns and processes to structure our understanding of, and engagement with, our world. A psychologically realistic account of understanding must begin with the patterns of ongoing interaction between an organism and its physical and cultural environments and must include both our emotional responses to changes in our body and environment, and also the actions by which we continuously transform our experience. Consequently, embodied understanding is not merely a conceptual/propositional activity of thought, but rather constitutes our most basic way of being in, and engaging with, our surroundings in a deep visceral manner.

  7. 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

  8. 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.

  9. Guidance for External Events Analysis

    International Nuclear Information System (INIS)

    This Guidance for External Events Analysis was developed under a contract with the Nordic PSA Group, and aims at creating a common framework for analysis of external events as part of a nuclear power plant Probabilistic Safety Assessment. Thus, the purpose of this Guidance is to constitute a common methodological guidance for the analysis of external events at Nordic nuclear power plants. This will make it possible for the utilities to perform these analyses in a cost-efficient way, assuring simultaneously the quality of the analyses. The Guidance is meant to clarify the scope of the analysis of external events, to provide guidance for the performance of the analysis, and to help in defining, subcontracting and reviewing the work. The analysis procedure includes four phases, addressing project planning, identification of external events, screening of events, and probabilistic analysis. The aim is first to do as complete an identification of potential single and combined external events as possible. Thereafter, as many external events as possible are screened out as early as possible. The screening capability is increased during the project, using the continuously acquired information on the events and on their effects on the plant

  10. traumatismes externes du larynx external laryngeal trauma of larynx

    African Journals Online (AJOL)

    Introduction : Le traumatisme externe du larynx est relativement rare mais expose à un risque vital immédiat. En l'absence de dia- gnostic et de prise en charge rapide il expose à des séquelles fonctionnelles. Le but de ce travail est de rappeler la présentation clinique des traumatismes externes du larynx et d'étayer notre ...

  11. Matchings with Externalities and Attitudes

    DEFF Research Database (Denmark)

    Branzei, Simina; Michalak, Tomasz; Rahwan, Talal

    2013-01-01

    Two-sided matchings are an important theoretical tool used to model markets and social interactions. In many real-life problems the utility of an agent is influenced not only by their own choices, but also by the choices that other agents make. Such an influence is called an externality. Whereas...... fully expressive representations of externalities in matchings require exponential space, in this paper we propose a compact model of externalities, in which the influence of a match on each agent is computed additively. Under this framework, we analyze many-to-many matchings and one-to-one matchings...

  12. Matching Games with Additive Externalities

    DEFF Research Database (Denmark)

    Branzei, Simina; Michalak, Tomasz; Rahwan, Talal

    2012-01-01

    Two-sided matchings are an important theoretical tool used to model markets and social interactions. In many real life problems the utility of an agent is influenced not only by their own choices, but also by the choices that other agents make. Such an influence is called an externality. Whereas...... fully expressive representations of externalities in matchings require exponential space, in this paper we propose a compact model of externalities, in which the influence of a match on each agent is computed additively. In this framework, we analyze many-to-many and one-to-one matchings under neutral...

  13. External effects in Swiss hydropower

    International Nuclear Information System (INIS)

    Hauenstein, W.; Bonvin, J.; Vouillamoz, J.

    1999-01-01

    The article discusses the external costs and benefits of hydropower that are not internalised in normal book-keeping. Several negative and positive effects are discussed. The results of a study that addressed the difficult task of quantifying these external effects are presented. An assessment of the results gained shows that difficulties are to be met regarding system limits, methods of expressing the effects in monetary terms and ethical factors. The report also examines the consideration of external effects as a correction factor for falsified market prices for electricity

  14. Understanding semantics

    DEFF Research Database (Denmark)

    Thrane, Torben

    1997-01-01

    Understanding natural language is a cognitive, information-driven process. Discussing some of the consequences of this fact, the paper offers a novel look at the semantic effect of lexical nouns and the identification of reference types....

  15. Understanding Alzheimer's

    Science.gov (United States)

    ... Navigation Bar Home Current Issue Past Issues Understanding Alzheimer's Past Issues / Fall 2007 Table of Contents For ... and brain scans. No treatment so far stops Alzheimer's. However, for some in the disease's early and ...

  16. Understanding homelessness

    OpenAIRE

    Somerville, Peter

    2013-01-01

    This paper reviews the literature on understanding homelessness. It criticizes approaches that ignore, distort or diminish the humanity of homeless people, or else, add little to our understanding of that humanity. In particular, it rejects what it calls “epidemiological” approaches, which deny the possibility of agency for homeless people, insofar as those approaches view the situation of those people largely as a “social fact”, to be explained in terms of causal variables or “risk factors” ...

  17. External imaging of human atherosclerosis

    International Nuclear Information System (INIS)

    Lees, R.S.; Lees, A.M.

    1986-01-01

    For external imaging of arteriosclerotic lesions in blood vessels, low-density lipoproteins labeled by 99 Tc were employed, instead of radiolabelled blood platelets. The results suggest that the ability to be imaged correlates with lesion activity. (Auth.)

  18. 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.

  19. 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

  20. Ideological systems and its validation: a neutrosophic approach

    Directory of Open Access Journals (Sweden)

    Josué Nescolarde-Selva

    2015-09-01

    Full Text Available Ideologies face two critical problems in the reality, the problem of commitment and the problem of validation. Commitment and validation are two separate phenomena, in spite of the near universal myth that the human is committed because his beliefs are valid. Ideologies not only seem external and valid but also worth whatever discomforts believing entails. In this paper the authors develop a theory of social commitment and social validation using concepts of validation of neutrosophic logic.

  1. 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

  2. Parallel External Memory Graph Algorithms

    DEFF Research Database (Denmark)

    Arge, Lars Allan; Goodrich, Michael T.; Sitchinava, Nodari

    2010-01-01

    In this paper, we study parallel I/O efficient graph algorithms in the Parallel External Memory (PEM) model, one o f the private-cache chip multiprocessor (CMP) models. We study the fundamental problem of list ranking which leads to efficient solutions to problems on trees, such as computing lowest...... an optimal speedup of ¿(P) in parallel I/O complexity and parallel computation time, compared to the single-processor external memory counterparts....

  3. Does external walking environment affect gait patterns?

    Science.gov (United States)

    Patterson, Matthew R; Whelan, Darragh; Reginatto, Brenda; Caprani, Niamh; Walsh, Lorcan; Smeaton, Alan F; Inomata, Akihiro; Caulfield, Brian

    2014-01-01

    The objective of this work is to develop an understanding of the relationship between mobility metrics obtained outside of the clinic or laboratory and the context of the external environment. Ten subjects walked with an inertial sensor on each shank and a wearable camera around their neck. They were taken on a thirty minute walk in which they mobilized over the following conditions; normal path, busy hallway, rough ground, blind folded and on a hill. Stride time, stride time variability, stance time and peak shank rotation rate during swing were calculated using previously published algorithms. Stride time was significantly different between several of the conditions. Technological advances mean that gait variables can now be captured as patients go about their daily lives. The results of this study show that the external environment has a significant impact on the quality of gait metrics. Thus, context of external walking environment is an important consideration when analyzing ambulatory gait metrics from the unsupervised home and community setting.

  4. External Costs Related to Power Production Technologies

    DEFF Research Database (Denmark)

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1997-01-01

    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 of...

  5. Understanding Maple

    CERN Document Server

    Thompson, Ian

    2016-01-01

    Maple is a powerful symbolic computation system that is widely used in universities around the world. This short introduction gives readers an insight into the rules that control how the system works, and how to understand, fix, and avoid common problems. Topics covered include algebra, calculus, linear algebra, graphics, programming, and procedures. Each chapter contains numerous illustrative examples, using mathematics that does not extend beyond first-year undergraduate material. Maple worksheets containing these examples are available for download from the author's personal website. The book is suitable for new users, but where advanced topics are central to understanding Maple they are tackled head-on. Many concepts which are absent from introductory books and manuals are described in detail. With this book, students, teachers and researchers will gain a solid understanding of Maple and how to use it to solve complex mathematical problems in a simple and efficient way.

  6. Understanding physics

    CERN Document Server

    Mansfield, Michael

    2011-01-01

    Understanding Physics - Second edition is a comprehensive, yet compact, introductory physics textbook aimed at physics undergraduates and also at engineers and other scientists taking a general physics course. Written with today's students in mind, this text covers the core material required by an introductory course in a clear and refreshing way. A second colour is used throughout to enhance learning and understanding. Each topic is introduced from first principles so that the text is suitable for students without a prior background in physics. At the same time the book is designed to enable

  7. The suitability of internal versus external successors

    DEFF Research Database (Denmark)

    Boyd, Britta; Royer, Susanne

    2012-01-01

    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.......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...

  8. Understanding Energy

    Science.gov (United States)

    Menon, Deepika; Shelby, Blake; Mattingly, Christine

    2016-01-01

    "Energy" is a term often used in everyday language. Even young children associate energy with the food they eat, feeling tired after playing soccer, or when asked to turn the lights off to save light energy. However, they may not have the scientific conceptual understanding of energy at this age. Teaching energy and matter could be…

  9. 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.

  10. In vitro test of external Qigong

    Directory of Open Access Journals (Sweden)

    Reading Melissa

    2004-03-01

    Full Text Available Abstract Background Practitioners of the alternative medical practice 'external Qigong' generally claim the ability to emit or direct "healing energy" to treat patients. We investigated the ability of experienced Qigong practitioners to enhance the healthy growth of cultured human cells in a series of studies, each following a rigorously designed protocol with randomization, blinding and controls for variability. Methods Qigong practitioners directed healing intentionality toward normal brain cell cultures in a basic science laboratory. Qigong treatments were delivered for 20 minutes from a minimum distance of 10 centimeters. Cell proliferation was measured by a standard colony-forming efficiency (CFE assay and a CFE ratio (CFE for treated samples/CFE for sham samples was the dependent measure for each experiment. Results During a pilot study (8 experiments, a trend of increased cell proliferation in Qigong-treated samples (CFE Qigong/sham ratios > 1.0 was observed (P = 0.162. In a formal study (28 experiments, a similar trend was observed, with Qigong-treated samples showing on average more colony formation than sham samples (P = 0.036. In a replication study (60 experiments, no significant difference between Qigong-treated samples and sham samples was observed (P = 0.465. Conclusion We observed an apparent increase in the proliferation of cultured cells following external Qigong treatment by practitioners under strictly controlled conditions, but we did not observe this effect in a replication study. These results suggest the need for more controlled and thorough investigation of external Qigong before scientific validation is claimed.

  11. Pervasive externalities at the population, consumption, and environment nexus.

    Science.gov (United States)

    Dasgupta, Partha S; Ehrlich, Paul R

    2013-04-19

    Growing concerns that contemporary patterns of economic development are unsustainable have given rise to an extensive empirical literature on population growth, consumption increases, and our growing use of nature's products and services. However, far less has been done to reach a theoretical understanding of the socio-ecological processes at work at the population-consumption-environment nexus. In this Research Article, we highlight the ubiquity of externalities (which are the unaccounted for consequences for others, including future people) of decisions made by each of us on reproduction, consumption, and the use of our natural environment. Externalities, of which the "tragedy of the commons" remains the most widely discussed illustration, are a cause of inefficiency in the allocation of resources across space, time, and contingencies; in many situations, externalities accentuate inequity as well. Here, we identify and classify externalities in consumption and reproductive decisions and use of the natural environment so as to construct a unified theoretical framework for the study of data drawn from the nexus. We show that externalities at the nexus are not self-correcting in the marketplace. We also show that fundamental nonlinearities, built into several categories of externalities, amplify the socio-ecological processes operating at the nexus. Eliminating the externalities would, therefore, require urgent collective action at both local and global levels.

  12. Understanding translation

    DEFF Research Database (Denmark)

    Schjoldager, Anne Gram; Gottlieb, Henrik; Klitgård, Ida

    Understanding Translation is designed as a textbook for courses on the theory and practice of translation in general and of particular types of translation - such as interpreting, screen translation and literary translation. The aim of the book is to help you gain an in-depth understanding...... of the phenomenon of translation and to provide you with a conceptual framework for the analysis of various aspects of professional translation. Intended readers are students of translation and languages, but the book will also be relevant for others who are interested in the theory and practice of translation...... - translators, language teachers, translation users and literary, TV and film critics, for instance. Discussions focus on translation between Danish and English....

  13. Understanding Resilience

    Directory of Open Access Journals (Sweden)

    Gang eWu

    2013-02-01

    Full Text Available Resilience is the ability to adapt successfully in the face of stress and adversity. Stressful life events, trauma and chronic adversity can have a substantial impact on brain function and structure, and can result in the development of PTSD, depression and other psychiatric disorders. However, most individuals do not develop such illnesses after experiencing stressful life events, and are thus thought to be resilient. Resilience as successful adaptation relies on effective responses to environmental challenges and ultimate resistance to the deleterious effects of stress, therefore a greater understanding of the factors that promote such effects is of great relevance. This review focuses on recent findings regarding genetic, epigenetic, developmental, psychosocial and neurochemical factors that are considered essential contributors to the development of resilience. Neural circuits and pathways involved in mediating resilience are also discussed. The growing understanding of resilience factors will hopefully lead to the development of new pharmacological and psychological interventions for enhancing resilience and mitigating the untoward consequences.

  14. 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.

  15. Understand electronics

    CERN Document Server

    Bishop, Owen

    2013-01-01

    Understand Electronics provides a readable introduction to the exciting world of electronics for the student or enthusiast with little previous knowledge. The subject is treated with the minimum of mathematics and the book is extensively illustrated.This is an essential guide for the newcomer to electronics, and replaces the author's best-selling Beginner's Guide to Electronics.The step-by-step approach makes this book ideal for introductory courses such as the Intermediate GNVQ.

  16. Understanding users

    DEFF Research Database (Denmark)

    Johannsen, Carl Gustav Viggo

    2014-01-01

    Segmentation of users can help libraries in the process of understanding user similarities and differences. Segmentation can also form the basis for selecting segments of target users and for developing tailored services for specific target segments. Several approaches and techniques have been...... segmentation project using computer-generated clusters. Compared to traditional marketing texts, this article also tries to identify user segments or images or metaphors by the library profession itself....

  17. Understanding unemployment

    OpenAIRE

    Guillaume Rocheteau

    2006-01-01

    Modern economists have built models of the labor market, which isolate the market’s key drivers and describe the way these interact to produce particular levels of unemployment. One of the most popular models used by macroeconomists today is the search-matching model of equilibrium unemployment. We explain this model, and show how it can be applied to understand the way various policies, such as unemployment benefits, taxes, or technological changes, can affect the unemployment rate.

  18. Space station neutral external environment

    Science.gov (United States)

    Ehlers, H.; Leger, L.

    1988-01-01

    Molecular contamination levels arising from the external induced neutral environment of the Space Station (Phase 1 configuration) were calculated using the MOLFLUX model. Predicted molecular column densities and deposition rates generally meet the Space Station contamination requirements. In the doubtful cases of deposition due to materials outgassing, proper material selection, generally excluding organic products exposed to the external environment, must be considered to meet contamination requirements. It is important that the Space Station configuration, once defined, is not significantly modified to avoid introducing new unacceptable contamination sources.

  19. Understanding Technology?

    Directory of Open Access Journals (Sweden)

    Erik Bendtsen

    2016-11-01

    Full Text Available We are facing radical changes in our ways of living in the nearest future. Not necessarily of our own choice, but because tchnological development is moving so fast, that it will have still greater impact on many aspects of our lives. We have seen the beginnings of that change within the latest 35 years or so, but according to newest research that change will speed up immensely in the nearest years to come. The impact of that change or these changes will affect our working life immensely as a consequence of automation. How these changes are brought about and which are their consequences in a broad sense is being attempted to be understood and guessed by researchers. No one knows for sure, but specific patterns are visible. This paper will not try to guess, what will come, but will rather try to understand the deepest ”nature” of technology in order to understand the driving factors in this development: the genesis of technology in a broad sense in order to contibute to the understanding of the basis for the expected development.

  20. PHOSPHORUS SORPTION ISOTHERMS AND EXTERNAL ...

    African Journals Online (AJOL)

    ACSS

    Zhang et al., 2005). For instance, in strongly acidic soils with pH<5.5 and high P sorbing soils, application of rock phosphate is more effective and cheaper than using TSP (Bationo et al., 2011). Moreover, it enables determination of the external P.

  1. Organizing for External Knowledge Sourcing

    DEFF Research Database (Denmark)

    Rabbiosi, Larissa; Reichstein, Toke

    2011-01-01

    The aim of this article is to provide an introduction to the special issue. We briefly consider the external knowledge sourcing and organizing for innovation literatures, which offer a background for the special issue, and we highlight their mutual dialogue. We then illustrate the main findings o...

  2. Femoral Reconstruction Using External Fixation

    Directory of Open Access Journals (Sweden)

    Yevgeniy Palatnik

    2011-01-01

    Full Text Available Background. The use of an external fixator for the purpose of distraction osteogenesis has been applied to a wide range of orthopedic problems caused by such diverse etiologies as congenital disease, metabolic conditions, infections, traumatic injuries, and congenital short stature. The purpose of this study was to analyze our experience of utilizing this method in patients undergoing a variety of orthopedic procedures of the femur. Methods. We retrospectively reviewed our experience of using external fixation for femoral reconstruction. Three subgroups were defined based on the primary reconstruction goal lengthening, deformity correction, and repair of nonunion/bone defect. Factors such as leg length discrepancy (LLD, limb alignment, and external fixation time and complications were evaluated for the entire group and the 3 subgroups. Results. There was substantial improvement in the overall LLD, femoral length discrepancy, and limb alignment as measured by mechanical axis deviation (MAD and lateral distal femoral angle (LDFA for the entire group as well as the subgroups. Conclusions. The Ilizarov external fixator allows for decreased surgical exposure and preservation of blood supply to bone, avoidance of bone grafting and internal fixation, and simultaneous lengthening and deformity correction, making it a very useful technique for femoral reconstruction.

  3. Lupus vulgaris of external nose

    OpenAIRE

    Bhandary, Satheesh Kumar; Ranganna, B. Usha

    2008-01-01

    Lupus vulgaris is the commonest form of cutaneous tuberculosis which commonly involve trunk and buttocks. Lupus vulgaris affecting nose and face, are rarely reported in India. This study reports an unusual case of lupus vulgaris involving the external nose that showed dramatic outcome after six months of anti- tubercular treatment.

  4. EAMJ External Dec 09.indd

    African Journals Online (AJOL)

    2009-12-12

    Dec 12, 2009 ... the dental chair light and a dental probe. The tooth revealed the presence of at least two canal orifices on the floor of the pulp chamber. (iv) Three-rooted when three external roots were observed. Figure 1 (a-d) shows the four root types. Figure 1 (a-d). Premolars depicting one root (a), two distinct roots (b),.

  5. Understanding uncertainty

    CERN Document Server

    Lindley, Dennis V

    2013-01-01

    Praise for the First Edition ""...a reference for everyone who is interested in knowing and handling uncertainty.""-Journal of Applied Statistics The critically acclaimed First Edition of Understanding Uncertainty provided a study of uncertainty addressed to scholars in all fields, showing that uncertainty could be measured by probability, and that probability obeyed three basic rules that enabled uncertainty to be handled sensibly in everyday life. These ideas were extended to embrace the scientific method and to show how decisions, containing an uncertain element, could be rationally made.

  6. 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 ...

  7. Understanding analysis

    CERN Document Server

    Abbott, Stephen

    2015-01-01

    This lively introductory text exposes the student to the rewards of a rigorous study of functions of a real variable. In each chapter, informal discussions of questions that give analysis its inherent fascination are followed by precise, but not overly formal, developments of the techniques needed to make sense of them. By focusing on the unifying themes of approximation and the resolution of paradoxes that arise in the transition from the finite to the infinite, the text turns what could be a daunting cascade of definitions and theorems into a coherent and engaging progression of ideas. Acutely aware of the need for rigor, the student is much better prepared to understand what constitutes a proper mathematical proof and how to write one. Fifteen years of classroom experience with the first edition of Understanding Analysis have solidified and refined the central narrative of the second edition. Roughly 150 new exercises join a selection of the best exercises from the first edition, and three more project-sty...

  8. Understanding ayurveda.

    Science.gov (United States)

    Gadgil, Vaidya Dilip

    2010-01-01

    Ayurveda needs to achieve its full potential both in India and globally. This requires imparting to its students full appreciation of Ayurveda's power and strength, particularly proper understanding of the advantages of applying it to treat chronic and acute diseases. To this end, we explain the necessity of learning Sanskrit as a medium of study, and the advantages of learning the Texts in the traditional way, rather than relying on translations with all the loss of meaning and precision, which that entails. We emphasize the use of Triskandhakosha as a means to fully understand Ayurveda fundamental concepts and technical terms, so that all their shades of meaning are fully understood, and all their usages given in different places in the texts. Only by such methods can full appreciation of Ayurvedic wisdom be achieved, and the full depth and power of its knowledge be applied. Only then will its true status among systems of medicine come to be appreciated, either in India or more widely in the world as a whole.

  9. Understanding Ayurveda

    Directory of Open Access Journals (Sweden)

    Vaidya Dilip Gadgil

    2010-01-01

    Full Text Available Ayurveda needs to achieve its full potential both in India and globally. This requires imparting to its students full appreciation of Ayurveda′s power and strength, particularly proper understanding of the advantages of applying it to treat chronic and acute diseases. To this end, we explain the necessity of learning Sanskrit as a medium of study, and the advantages of learning the Texts in the traditional way, rather than relying on translations with all the loss of meaning and precision, which that entails. We emphasize the use of Triskandhakosha as a means to fully understand Ayurveda fundamental concepts and technical terms, so that all their shades of meaning are fully understood, and all their usages given in different places in the texts. Only by such methods can full appreciation of Ayurvedic wisdom be achieved, and the full depth and power of its knowledge be applied. Only then will its true status among systems of medicine come to be appreciated, either in India or more widely in the world as a whole.

  10. 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.)

  11. 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.

  12. Validity of self-assessment in a quality improvement collaborative in Ecuador.

    Science.gov (United States)

    Hermida, Jorge; Broughton, Edward I; Miller Franco, Lynne

    2011-12-01

    Health care quality improvement (QI) efforts commonly use self-assessment to measure compliance with quality standards. This study investigates the validity of self-assessment of quality indicators. Cross sectional. A maternal and newborn care improvement collaborative intervention conducted in health facilities in Ecuador in 2005. Four external evaluators were trained in abstracting medical records to calculate six indicators reflecting compliance with treatment standards. About 30 medical records per month were examined at 12 participating health facilities for a total of 1875 records. The same records had already been reviewed by QI teams at these facilities (self-assessment). Overall compliance, agreement (using the Kappa statistic), sensitivity and specificity were analyzed. We also examined patterns of disagreement and the effect of facility characteristics on levels of agreement. External evaluators reported compliance of 69-90%, while self-assessors reported 71-92%, with raw agreement of 71-95% and Kappa statistics ranging from fair to almost perfect agreement. Considering external evaluators as the gold standard, sensitivity of self-assessment ranged from 90 to 99% and specificity from 48 to 86%. Simpler indicators had fewer disagreements. When disagreements occurred between self-assessment and external valuators, the former tended to report more positive findings in five of six indicators, but this tendency was not of a magnitude to change program actions. Team leadership, understanding of the tools and facility size had no overall impact on the level of agreement. When compared with external evaluation (gold standard), self-assessment was found to be sufficiently valid for tracking QI team performance. Sensitivity was generally higher than specificity. Simplifying indicators may improve validity.

  13. Understanding physics

    CERN Document Server

    Cassidy, David; Rutherford, James

    2002-01-01

    Understanding Physics provides a thorough grounding in contemporary physics while placing physics into its social and historical context Based in large part on the highly respected Project Physics Course developed by two of the authors, it also integrates the results of recent pedagogical research The text thus - teaches about the basic phenomena in the physical world and the concepts developed to explain them - shows that science is a rational human endeavor with a long and continuing tradition, involving many different cultures and people - develops facility in critical thinking, reasoned argumentation, evaluation of evidence, mathematical modeling, and ethical values The treatment emphasizes not only what we know but also how we know it, why we believe it, and what effects that knowledge has - Why do we believe the Earth and planets revolve around the Sun? - Why do we believe that matter is made of atoms? - How do relativity theory and quantum mechanics alter our conception of Nature and in what ways do th...

  14. 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.

  15. 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

  16. Validity and reliability of the classroom participation questionnaire with deaf and hard of hearing students in public schools.

    Science.gov (United States)

    Antia, Shirin D; Sabers, Darrell L; Stinson, Michael S

    2007-01-01

    The Classroom Participation Questionnaire (CPQ) was administered to 136 deaf or hard of hearing (D/HH) students attending general education classrooms in Grades 4-10. The CPQ is a student-rated measure that yields scores for Understanding Teachers, Understanding Students, Positive Affect, and Negative Affect. Validity and reliability of a long (28-item) and a short (16-item) form are reported. We provide evidence of (a) internal structure validity through an examination of the relationships between the subscales and an analysis of interitem reliability within each scale, (b) reliability over time by examining the scores of students over a 3-year period, and (c) external structure validity through an examination of the relationships of the CPQ with measures of teacher-rated academic competence and Stanford achievement scores. The results suggest that both the long and short form of the CPQ can be used to assess participation of D/HH students in general education classrooms.

  17. Consumer or Citizen: A Study About Externalities in Energy Consumption

    Directory of Open Access Journals (Sweden)

    Luciano Ferreira da Silva

    2016-07-01

    Full Text Available The main purpose of this article is to discuss how negative externalities generated by consumption can have impact on the same individual in his/her role as a citizen and consumer. Therefore, in order to highlight this relation,a generation, distribution and consumption of electricity systemwas presented. Asto  methodological procedures, anexploratory and deductive typehas been adopted so as to approach the study, ie, we have started from general concepts on consumer behaviour and externalities, in order to build a relationship between the two concepts so as to explain citizen-conscious consumption-citizen. Regarding the analysis, a qualitative approach has been used for appreciation of content analysis. The main results of this research that can be highlighted are that both the negative externalities generated in production and distribution and the negative consumption externalities are absorbed by individuals in their roles as consumers or citizens. In this case, externalities are assimilated in the power supply bill or the government bill. So anyway the individual will pay,either as a consumer or as a citizen. So, to understand that externalities generated in consumer processes will be internalized and directed to oneself,, one can build a sense of "consumer-citizen".

  18. 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)

  19. MGR External Events Hazards Analysis

    International Nuclear Information System (INIS)

    Booth, L.

    1999-01-01

    The purpose and objective of this analysis is to apply an external events Hazards Analysis (HA) to the License Application Design Selection Enhanced Design Alternative 11 [(LADS EDA II design (Reference 8.32))]. The output of the HA is called a Hazards List (HL). This analysis supersedes the external hazards portion of Rev. 00 of the PHA (Reference 8.1). The PHA for internal events will also be updated to the LADS EDA II design but under a separate analysis. Like the PHA methodology, the HA methodology provides a systematic method to identify potential hazards during the 100-year Monitored Geologic Repository (MGR) operating period updated to reflect the EDA II design. The resulting events on the HL are candidates that may have potential radiological consequences as determined during Design Basis Events (DBEs) analyses. Therefore, the HL that results from this analysis will undergo further screening and analysis based on the criteria that apply during the performance of DBE analyses

  20. Firm Search for External Knowledge

    DEFF Research Database (Denmark)

    Sofka, Wolfgang; Grimpe, Christoph

    2012-01-01

    ignored the institutional context that provides or denies access to external knowledge at the country level. Combining institutional and knowledge search theory, we suggest that the market orientation of the institutional environment and the magnitude of institutional change influence when firms begin......The innovation performance of modern firms is increasingly determined by their ability to search and absorb external knowledge. However, after a certain threshold firms "oversearch" their environment and innovation performance declines. In this paper, we argue that prior literature has largely...... to experience the negative performance effects of oversearch. Based on a comprehensive sample of almost 8,000 firms from ten European countries, we find that institutions matter considerably for firms' search activity. Higher market orientation of institutions increases the effectiveness of firms' search...

  1. MGR External Events Hazards Analysis

    Energy Technology Data Exchange (ETDEWEB)

    L. Booth

    1999-11-06

    The purpose and objective of this analysis is to apply an external events Hazards Analysis (HA) to the License Application Design Selection Enhanced Design Alternative 11 [(LADS EDA II design (Reference 8.32))]. The output of the HA is called a Hazards List (HL). This analysis supersedes the external hazards portion of Rev. 00 of the PHA (Reference 8.1). The PHA for internal events will also be updated to the LADS EDA II design but under a separate analysis. Like the PHA methodology, the HA methodology provides a systematic method to identify potential hazards during the 100-year Monitored Geologic Repository (MGR) operating period updated to reflect the EDA II design. The resulting events on the HL are candidates that may have potential radiological consequences as determined during Design Basis Events (DBEs) analyses. Therefore, the HL that results from this analysis will undergo further screening and analysis based on the criteria that apply during the performance of DBE analyses.

  2. Conceptual challenges for internalising externalities

    DEFF Research Database (Denmark)

    Miguel, Brandão; Weidema, Bo Pedersen

    2013-01-01

    We analyse a number of different externalities to identify conceptual challenges for the practical implementation of their internalisation. Three issues were identified: i) The balance between compensation and technology change and the respective effects on the nominal and real GDP; ii) The relev......We analyse a number of different externalities to identify conceptual challenges for the practical implementation of their internalisation. Three issues were identified: i) The balance between compensation and technology change and the respective effects on the nominal and real GDP; ii......) The relevance and efficiency of different instruments for internalisation and compensation; and iii) Implementing internalisation over large geographical and temporal distances. We find taxation to be a more relevant and efficient tool for internalisation than insurance and litigation. With increasing...

  3. BOP Crises and External Shocks

    OpenAIRE

    Kitano, Shigeto

    2003-01-01

    This is a theoretical study of BOP crises in emerging markets in East Asia and LatinAmerica in the l990s. These BOP crises tend to be preceded by the current account deterioration, the real exchange rate appreciation, and inflationary pressures. The paper develops a model of BOP crises preceded by these macroeconomic phenomena. The model shows that an external shock (a decrease in the world nominal interest rate) leads to this type of BOP crises.

  4. Acute incarcerated external abdominal hernia

    OpenAIRE

    Yang, Xue-Fei; Liu, Jia-Lin

    2014-01-01

    External abdominal hernia occurs when abdominal organs or tissues leave their normal anatomic site and protrude outside the skin through the congenital or acquired weakness, defects or holes on the abdominal wall, including inguinal hernia, umbilical hernia, femoral hernia and so on. Acute incarcerated hernia is a common surgical emergency. With advances in minimally invasive devices and techniques, the diagnosis and treatment have witnessed major changes, such as the use of laparoscopic surg...

  5. Personnel external dose monitoring system

    International Nuclear Information System (INIS)

    Zhao Hengyuan

    1989-01-01

    The status and trend of personnel external dose monitoring system are introduced briefly. Their characteristics, functions and TLD bedges of some commercially available automatic TLD system, including UD-710A (Matsushita, Japan), Harshaw-2271, 2276 (Harshaw, USA), Harshaw-8000 (Harshaw/Filtrol), Studsvik-1313 (Sweden) and Pitman-800 (UK) were depicted in detail. Finally, personnel dose management and record keeping system were presented and two examples were given

  6. Random matrix theory with an external source

    CERN Document Server

    Brézin, Edouard

    2016-01-01

    This is a first book to show that the theory of the Gaussian random matrix is essential to understand the universal correlations with random fluctuations and to demonstrate that it is useful to evaluate topological universal quantities. We consider Gaussian random matrix models in the presence of a deterministic matrix source. In such models the correlation functions are known exactly for an arbitrary source and for any size of the matrices. The freedom given by the external source allows for various tunings to different classes of universality. The main interest is to use this freedom to compute various topological invariants for surfaces such as the intersection numbers for curves drawn on a surface of given genus with marked points, Euler characteristics, and the Gromov–Witten invariants. A remarkable duality for the average of characteristic polynomials is essential for obtaining such topological invariants. The analysis is extended to nonorientable surfaces and to surfaces with boundaries.

  7. 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

  8. Verification and validation benchmarks.

    Energy Technology Data Exchange (ETDEWEB)

    Oberkampf, William Louis; Trucano, Timothy Guy

    2007-02-01

    Verification and validation (V&V) are the primary means to assess the accuracy and reliability of computational simulations. V&V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V&V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the level of

  9. Verification and validation benchmarks

    International Nuclear Information System (INIS)

    Oberkampf, William L.; Trucano, Timothy G.

    2008-01-01

    Verification and validation (V and V) are the primary means to assess the accuracy and reliability of computational simulations. V and V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V and V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the

  10. Validation philosophy

    International Nuclear Information System (INIS)

    Vornehm, D.

    1994-01-01

    To determine when a set of calculations falls within an umbrella of an existing validation documentation, it is necessary to generate a quantitative definition of range of applicability (our definition is only qualitative) for two reasons: (1) the current trend in our regulatory environment will soon make it impossible to support the legitimacy of a validation without quantitative guidelines; and (2) in my opinion, the lack of support by DOE for further critical experiment work is directly tied to our inability to draw a quantitative open-quotes line-in-the-sandclose quotes beyond which we will not use computer-generated values

  11. Understanding PISA

    Directory of Open Access Journals (Sweden)

    Stephen DOWNES

    2005-04-01

    Full Text Available Understanding PISA Stephen DOWNESMoncton, CANADA ABSTRACT The headline was dramatic enough to cause a ripple in the reading public. "Students who use computers a lot at school have worse maths and reading performance," noted the BBC news article, citing a 2004 study by Ludger Woessmann and Thomas Fuchs (Fuchs and Woessman, 2004. It was not long before the blogosphere took notice. Taking the theme and running with it, Alice and Bill ask, "Computers Make School Kids Dumber?" They theorize, "If you track the admitted decline of education, you'll probably notice that it follows along with the increase of technology in the classroom." In a similar vein, James Bartholomew asks, "Do you think that the government will turn down the volume of its boasting about how it has spent billions introducing computers in schools (while keeping down the pay of teachers so much that there are shortages? Do you think it will stop sending governors of state schools glossy pamphlets about insisting that computers are used in their schools as much as possible?" In this study, therefore, PISA looks well beyond educational attainment, and also includes school demographics, such as whether it is a public or private school, has large or small classes, or has access or not to technological resources. Finally, it does measure student information-their family background, access to books and computers and parental support as well. The PISA survey departs from previous surveys in disregarding the stated curricula of the schools being measured. Therefore, the conclusion is not surprising, nor even wrong for him to consider independently of any parental or teacher support, considered without reference to the software running on it, considered without reference to student attitudes and interests, does not positively impact an education. Finally, he focus on missing the reporting of results

  12. Understanding the site selectivity in small-sized neutral and charged Al(n) (4 ≤ N ≤ 7) clusters using density functional theory based reactivity descriptors: a validation study on water molecule adsorption.

    Science.gov (United States)

    Das, Susanta; Pal, Sourav; Krishnamurty, Sailaja

    2013-09-12

    Aluminum clusters are now technologically important due to their high catalytic activity. Our present study on the small-sized aluminum clusters applies density functional theory (DFT)-based reactivity descriptors to identify potential sites for adsorption and eventual chemical reaction. Depending on symmetry, susceptibility of various type of reactive sites within a cluster toward an impending electrophilic and/or nucleophilic attack is predicted using the reactivity descriptors. In addition, the study devises general rules as to how the size, shape, and charge of the cluster influences the number of available sites for an electrophilic and/or nucleophilic attack. The predictions by reactivity descriptors are validated by performing an explicit adsorption of water molecule on Al clusters with four atoms. The adsorption studies demonstrate that the most stable water-cluster complex is obtained when the molecule is adsorbed through an oxygen atom on the site with the highest relative electrophilicity.

  13. Malignant external otitis in Spain.

    Science.gov (United States)

    Guerrero-Espejo, Antonio; Valenciano-Moreno, Inmaculada; Ramírez-Llorens, Rafael; Pérez-Monteagudo, Palmira

    Malignant external otitis is a necrotizing infection, which extends from the squamous epithelium of the ear canal to the adjacent tissue. The objective of the study was to investigate its incidence and other epidemiological data in Spain, reporting the largest case series to date. A descriptive, retrospective study of the Spanish population was carried out using the minimum basic data set (MBDS) based on data of patients admitted to hospitals in the 2008-2013 period. Patients whose diagnosis (principal or secondary) at discharge was encoded as 380.14 (malignant external otitis), according to ICD-9-CM, were included as cases. The Spanish incidence rate was calculated for all its communities and provinces, as well as by season and mortality. A total of 355 patients (302 as principal diagnosis and 53 as secondary) were diagnosed. The incidence rate was 1.30 (95% CI, 1.17 to 1.44) per 106 inhabitants and year, although there were variations among geographical areas. The median age of cases with main diagnosis was 74 years (range 10-95 years). The predominant age group was in patients over 84 years old (19.3 cases per 10 6 inhabitants and year). The incidence was higher in men and the male-female relative risk was 2.4. Diabetes was present in 74.6% of patients. The diagnosis was predominant in the last quarter of the year. The gross in-hospital mortality rate was 3.7%. Malignant external otitis is seen mostly among male elderly and diabetic patients. The incidence and mortality rate are low in Spain. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

  14. Skepticism, Contextualism, Externalism and Modality

    Directory of Open Access Journals (Sweden)

    Ron Wilburn

    2006-12-01

    Full Text Available In this paper, I argue for the following claims. Contextualist strategies to tame or localize epistemic skepticism are hopeless if contextualist factors are construed internalistically. However, because efforts to contextualize externalism via subjunctive conditional analysis court circularity, it is only on an internalistic interpretation that contextualist strategies can even be motivated. While these claims do not give us an argument for skepticism, they do give us an argument that contextualism, as such, is not likely to provide us with an argument against skepticism.

  15. 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.

  16. 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.

  17. Waveguide based external cavity semiconductor lasers

    NARCIS (Netherlands)

    Oldenbeuving, Ruud; Klein, E.J.; Offerhaus, Herman L.; Lee, Christopher James; Verhaegen, M.; Boller, Klaus J.

    2012-01-01

    We report on progress of the project waveguide based external cavity semiconductor laser (WECSL) arrays. Here we present the latest results on our efforts to mode lock an array of tunable, external cavity semiconductor lasers.

  18. 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

  19. Alignment validation

    Energy Technology Data Exchange (ETDEWEB)

    ALICE; ATLAS; CMS; LHCb; Golling, Tobias

    2008-09-06

    The four experiments, ALICE, ATLAS, CMS and LHCb are currently under constructionat CERN. They will study the products of proton-proton collisions at the Large Hadron Collider. All experiments are equipped with sophisticated tracking systems, unprecedented in size and complexity. Full exploitation of both the inner detector andthe muon system requires an accurate alignment of all detector elements. Alignmentinformation is deduced from dedicated hardware alignment systems and the reconstruction of charged particles. However, the system is degenerate which means the data is insufficient to constrain all alignment degrees of freedom, so the techniques are prone to converging on wrong geometries. This deficiency necessitates validation and monitoring of the alignment. An exhaustive discussion of means to validate is subject to this document, including examples and plans from all four LHC experiments, as well as other high energy experiments.

  20. Validation of the measure automobile emissions model : a statistical analysis

    Science.gov (United States)

    2000-09-01

    The Mobile Emissions Assessment System for Urban and Regional Evaluation (MEASURE) model provides an external validation capability for hot stabilized option; the model is one of several new modal emissions models designed to predict hot stabilized e...

  1. Externalized ileocolic anastomosis: case report.

    Science.gov (United States)

    Simcock, James; Kuntz, Charles A; Newman, Raquel

    2010-01-01

    A 6-year-old, spayed female Labrador retriever was presented 48 hours after an intestinal resection and anastomosis for management of a small intestinal foreign body. Abdominal ultrasound confirmed the presence of peritoneal effusion. Cytology of fluid collected by abdominocentesis revealed a large number of degenerate neutrophils with intracellular cocci. A diagnosis of septic peritonitis was made, presumably because of dehiscence of the anastomosis. Upon repeat exploratory celiotomy, the intestinal anastomosis (located 4 cm orad to the cecum) was found to be leaking intestinal contents into the abdomen. The distal ileum, cecum, and proximal colon were resected. An end-to-end, ileocolic anastomosis was performed and subsequently exteriorized into the subcutaneous space via a paramedian incision through the abdominal wall. The anastomosis was inspected daily for 4 days before it was returned to the abdomen and the subcutaneous defect was closed. Serial cytology of the peritoneal fluid, which was performed during this 4-day postoperative period, confirmed progressive resolution of peritonitis. The dog was discharged from the hospital 2 days following return of the anastomosis into the abdomen. Externalized intestinal anastomosis is used with good success in human medicine for repair of colonic injuries. In this case, externalization of the anastomosis permitted healing of the intestinal anastomosis in an environment isolated from the detrimental effects created by septic peritonitis. In addition, direct visualization of the anastomosis allowed assessment of healing. To our knowledge, this procedure has not been previously reported in companion animals.

  2. 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

  3. EXTERNAL FACTORS FOR THE MONETARY POLICY TRANSMISSION MECHANISM

    Directory of Open Access Journals (Sweden)

    Dan Horatiu

    2013-07-01

    Full Text Available This paper reviews and analyzes the effects that external (or exogenous factors, defined as economic factors that cannot be controlled or influenced by the central bank, have on monetary policy and the monetary policy transmission mechanism. Adopting a theoretical research position, we aim at identifying the main external factors to monetary policy and discuss the ways in which these factors alter the economic environment and implicitly the monetary policy transmission mechanism. This is done by changing the way in which monetary transmission channels work and deliver monetary policy decisions throughout the economy, with the final goal of producing central bank desired outcomes with regard to economic variables like inflation, employment, or the production level. We will begin this article with a brief introduction on the topic of monetary policy, the monetary policy transmission mechanism and the potential external factors that may influence the monetary policy and the functioning of its transmission mechanism. The main external factors are identified as linked to fiscal policy, commodity prices, financial market volatility or other globalization related processes. After this introduction, we will proceed with the analysis of the nature and influences of each of the above mentioned external factors on monetary policy and its transmission, indentifying the potential ways in which they can change the structure and internal processes of the transmission channels. As we will see in the study and highlight in our conclusion, the external factors cause decisive changes in the way monetary policy is transmitted, and thus will strongly influence the decisions that central banks take in order to alter key economic variables. The profound understanding of how these non-central bank controlled factors influence the monetary policy transmission mechanism is a key requirement for central banks, as only by being able to predict, recognize and evaluate the

  4. SANSMIC Validation.

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Paula D.; Rudeen, David Keith; Lord, David L.

    2014-08-01

    SANSMIC is solution mining software that was developed and utilized by SNL in its role as geotechnical advisor to the US DOE SPR for planning purposes. Three SANSMIC leach modes - withdrawal, direct, and reverse leach - have been revalidated with multiple test cases for each mode. The withdrawal mode was validated using high quality data from recent leach activity while the direct and reverse modes utilized data from historical cavern completion reports. Withdrawal results compared very well with observed data, including the location and size of shelves due to string breaks with relative leached volume differences ranging from 6 - 10% and relative radius differences from 1.5 - 3%. Profile comparisons for the direct mode were very good with relative leached volume differences ranging from 6 - 12% and relative radius differences from 5 - 7%. First, second, and third reverse configurations were simulated in order to validate SANSMIC over a range of relative hanging string and OBI locations. The first-reverse was simulated reasonably well with relative leached volume differences ranging from 1 - 9% and relative radius differences from 5 - 12%. The second-reverse mode showed the largest discrepancies in leach profile. Leached volume differences ranged from 8 - 12% and relative radius differences from 1 - 10%. In the third-reverse, relative leached volume differences ranged from 10 - 13% and relative radius differences were %7E4 %. Comparisons to historical reports were quite good, indicating that SANSMIC is essentially the same as documented and validated in the early 1980's.

  5. The external cruising costs of parking

    NARCIS (Netherlands)

    Inci, E.; van Ommeren, J.N.; Kobus, Martijn

    2017-01-01

    Existing work emphasizes the importance of traffic congestion externalities, but typically ignores cruising-for-parking externalities. We estimate the marginal external cruising costs of parking—that is, the time costs that an additional parked car imposes on drivers by inducing them to cruise for

  6. 46 CFR 64.19 - External pressure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false External pressure. 64.19 Section 64.19 Shipping COAST... HANDLING SYSTEMS Standards for an MPT § 64.19 External pressure. (a) A tank without a vacuum breaker must be designed to withstand an external pressure of 71/2 psig or more. (b) A tank with a vacuum breaker...

  7. 49 CFR 195.108 - External pressure.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External pressure. 195.108 Section 195.108 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Design Requirements § 195.108 External pressure. Any external pressure that will be exerted on the...

  8. 46 CFR 154.452 - External pressure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false External pressure. 154.452 Section 154.452 Shipping... Independent Tank Type C and Process Pressure Vessels § 154.452 External pressure. The design external pressure...) for tanks without a vacuum relief valve. P2=0, or the pressure relief valve setting for an enclosed...

  9. 187 AGRICULTURAL GROWTH AND EXTERNAL DEBT ...

    African Journals Online (AJOL)

    Agricultural revenue has not been able to sustain the external debt in. Nigeria despite the effort ... increasing external debt volume while real private investment expenditure decreases with .... results. Ehirim, N. C. Agricultural growth and External debt management in developing nations: Evidence from Nigeria (1960-. 2005) ...

  10. 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

  11. Advisory External Defibrillator Availability in General Practice.

    Science.gov (United States)

    Barry, T; Bury, G

    2015-01-01

    This study aimed to describe the availability of advisory external defibrillators (AEDs) in Irish General Practice. The study utilised a computer generated random sample of Irish general practitioners and involved a postal questionnaire, with telephone follow up of non-responders. The cohort of GPs already known to possess an AED (via participation in the Merit Project) was excluded. 115 valid paper survey responses were received representing a response rate of 59%. 5 of the responding GPs identified themselves as Merit project participants and were excluded from data analysis. 74/110 GPs (67%) reported having one or more AED(s) available for use at their practice. 41/77 GPs (53%) who had not responded to the paper survey but were contactable by telephone had an AED available. When AED availability was examined by practice setting a higher proportion of rural and mixed settings had AEDs available than in urban and city areas. Cost was reported as the most common reason for not having an AED.

  12. 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.)

  13. External noise when using biofuel

    International Nuclear Information System (INIS)

    Kotaleski, J.

    1994-08-01

    The aim of this study has been to cover sources of noise dealing with all steps in a biofuel chain; producing, transporting, storing and firing the biofuel. When the availability of relevant test results from noise surveys is not so good and mostly badly documented, the study has been concentrated on estimation of external noise for planning and design purposes, from a prospective biofuel-fired plant. A synoptic tabulation of estimated acoustic power levels from different noise sources, has been done. The results from measurements of external noise from different existing combined power and heating plants are tabulated. The Nordic model for simulation of external noise has been used for a prospective plant - VEGA - designed by Vattenfall. The aim has been to estimate its noise pollutions at critical points at the nearest residential area (250 m from the fenced industry area). The software - ILYD - is easy to handle, but knowledge about the model is necessary. A requisite for the reliability is the access to measurements or estimations of different sources of noise, at different levels of octaves from 63 to 8000 Hz. The degree of accuracy increases with the number of broad band sources, that are integrated. Using ILYD with available data, a night limit of 40 dB(A) should be possible to fulfill with good degree of accuracy at VEGA, between 10 pm and 7 am, with good planning and under normal operation conditions. A demand for 35 dB(A) as a limit can be harder to fulfill, especially at mornings from 6 to 7. Noise from heavy vehicles within the plant area is classified as industrial noise and not as road traffic noise. This type of noise depends very much on the way of driving and assumed acceleration. Concerning wheel-mounted loaders, they may then only be used during daytime. The simulations show, that even at daytime from 7 to 6 pm, it would be possible to use an acoustically damped chipping machine, inside the power industry area. 31 refs, 13 figs, tabs, 8

  14. Leveraging External Sources of Innovation

    DEFF Research Database (Denmark)

    West, Joel; Bogers, Marcel

    2014-01-01

    suggests several gaps in prior research. One is a tendency to ignore the importance of business models, despite their central role in distinguishing open innovation from earlier research on interorganizational collaboration in innovation. Another gap is a tendency in open innovation to use “innovation......, it suggests a four-phase model in which a linear process—(1) obtaining, (2) integrating, and (3) commercializing external innovations—is combined with (4) interaction between the firm and its collaborators. This model is used to classify papers taken from the top 25 innovation journals, complemented by highly...... cited work beyond those journals. A review of 291 open innovation-related publications from these sources shows that the majority of these articles indeed address elements of this inbound open innovation process model. Specifically, it finds that researchers have front-loaded their examination...

  15. External radiotherapy in thyroid cancer

    International Nuclear Information System (INIS)

    Samuel, A.M.; Shah, D.H.

    1999-01-01

    In the management of thyroid carcinoma (TC) of any histological type, surgery is the primary mode of treatment. The second modality for the management is treatment with radioactive iodine ( 131 I), especially, when the tumor has the ability to concentrate 131 I. External radiotherapy has a limited use in differentiated thyroid carcinoma (DTC). It is useful in the management of bulky residual tissue which is not completely resected, metastatic disease which does not concentrated radioiodine and as a palliative treatment for reliving pain in patients with distant metastases. The ER as an adjuvant treatment in both anaplastic and medullary carcinoma has a significant role to play and should be used more frequently than is presently being advocated and practiced

  16. 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.

  17. 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.

  18. [Automated external defibrillators, life vest defibrillator, or both?].

    Science.gov (United States)

    Conti, C Richard

    2012-03-01

    As most understand, survival of cardiac arrest victims falls significantly if cardioversion is not performed promptly. The standard of practice for out-of-hospital defibrillation is the implantable cardiac defibrillator; however, much has been written and discussed about the use of automated external defibrillators. Not as much has been written about life vest wearable defibrillators. How to use these devices will be reviewed in this article.

  19. Externalities of fuel cycles 'ExternE' project. Economic valuation. Economical valuation: An impact pathway approach

    International Nuclear Information System (INIS)

    Markandya, A.

    1994-01-01

    The EC/US study of the external costs of fuel cycles is designed to trace through all the environmental impacts arising from the use of a particular fuel, from the 'cradle' to the 'grave'; to quantify these impacts as far as possible (giving priority to those that are the considered the most important) and to value the damages arising from them in money terms as far as possible (again keeping to the priority listing established by the physical quantification). The fuel cycle has been identified as consisting of the following elements: activities -> emissions/burdens; emissions/burdens -> physical environmental impacts; physical impacts -> external environmental impacts; external impacts -> costs of these impacts. The activities consist of all the operations that are carried out in connection with the extraction transportation, use in electricity generation and finally disposal of the fuel. The emissions or burdens arising from the cycle result in physical impacts, which in turn imply certain environmental impacts. An illustration of a typical fuel cycle (coal) audits environmental impacts is given in Figures. The work of the fuels cycle study teams is to complete the valuation of the shaded areas but giving priority to those impacts that are likely to be quantitatively important. .Each fuel cycle is evaluated in a location-specific context, so that it refers to the impacts arising from the use of coal, or gas or whatever fuel is being considered at an actual plant that is operating. The purpose of this report on economic valuation is to: (a) examine the literature or economic valuation of environmental externalities in Europe; (b) assess its relevance to the fuel cycle study and (c) make recommendations on how the detailed analysis of the individual fuel cycles should use the economic valuation. It is important to recognize that the report is not a complete survey of all the research ever done on environmental valuation. Although as complete a survey of all the

  20. 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

  1. Understanding Autism in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Arnaldo Ballerini

    2012-01-01

    Full Text Available Detachment from external reality, distancing from others, closure into a sort of virtual hermitage, and prevalence of inner fantasies, are the descriptive aspects of autism. However, from an anthropological-phenomenological point of view, in schizophrenia, the autistic mode of life can arise from a person’s being confronted with a pathological crisis in the obviousness of the intersubjective world, essentially a crisis in the intersubjective foundation of human presence. The “condition of possibility” of the autistic way of being is the deficiency of the operation that phenomenology call empathetic-intuitive constitution of the Other, an Other which is the naturalness of evidence of being a subject like me. The theme of the Other, of intersubjectivity, has become so central in the psychopathological analysis of schizophrenic disorders because the modifications of interhuman encounter cannot be seen as the secondary consequences of symptoms but constitute the fundamental disorder of schizophrenic alienation. Revision of the concept of autism from the original definition, centered on the prevalence of inner fantasies, leads to the profound change with the vision of autism as “loss” and “void.” I call attention to possibility of phenomenological research to understand autistic world starting from this “void.”

  2. Understanding autism in schizophrenia.

    Science.gov (United States)

    Ballerini, Arnaldo

    2012-01-01

    Detachment from external reality, distancing from others, closure into a sort of virtual hermitage, and prevalence of inner fantasies, are the descriptive aspects of autism. However, from an anthropological-phenomenological point of view, in schizophrenia, the autistic mode of life can arise from a person's being confronted with a pathological crisis in the obviousness of the intersubjective world, essentially a crisis in the intersubjective foundation of human presence. The "condition of possibility" of the autistic way of being is the deficiency of the operation that phenomenology call empathetic-intuitive constitution of the Other, an Other which is the naturalness of evidence of being a subject like me. The theme of the Other, of intersubjectivity, has become so central in the psychopathological analysis of schizophrenic disorders because the modifications of interhuman encounter cannot be seen as the secondary consequences of symptoms but constitute the fundamental disorder of schizophrenic alienation. Revision of the concept of autism from the original definition, centered on the prevalence of inner fantasies, leads to the profound change with the vision of autism as "loss" and "void." I call attention to possibility of phenomenological research to understand autistic world starting from this "void."

  3. 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…

  4. 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

  5. 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.

  6. Impact Testing on Reinforced Carbon-Carbon Flat Panels With BX-265 and PDL-1034 External Tank Foam for the Space Shuttle Return to Flight Program

    Science.gov (United States)

    Melis, Matthew E.; Revilock, Duane M.; Pereira, Michael J.; Lyle, Karen H.

    2009-01-01

    Following the tragedy of the Orbiter Columbia (STS-107) on February 1, 2003, a major effort commenced to develop a better understanding of debris impacts and their effect on the space shuttle subsystems. An initiative to develop and validate physics-based computer models to predict damage from such impacts was a fundamental component of this effort. To develop the models it was necessary to physically characterize reinforced carbon-carbon (RCC) along with ice and foam debris materials, which could shed on ascent and impact the orbiter RCC leading edges. The validated models enabled the launch system community to use the impact analysis software LS-DYNA (Livermore Software Technology Corp.) to predict damage by potential and actual impact events on the orbiter leading edge and nose cap thermal protection systems. Validation of the material models was done through a three-level approach: Level 1-fundamental tests to obtain independent static and dynamic constitutive model properties of materials of interest, Level 2-subcomponent impact tests to provide highly controlled impact test data for the correlation and validation of the models, and Level 3-full-scale orbiter leading-edge impact tests to establish the final level of confidence for the analysis methodology. This report discusses the Level 2 test program conducted in the NASA Glenn Research Center (GRC) Ballistic Impact Laboratory with external tank foam impact tests on flat RCC panels, and presents the data observed. The Level 2 testing consisted of 54 impact tests in the NASA GRC Ballistic Impact Laboratory on 6- by 6-in. and 6- by 12-in. flat plates of RCC and evaluated two types of debris projectiles: BX-265 and PDL-1034 external tank foam. These impact tests helped determine the level of damage generated in the RCC flat plates by each projectile and validated the use of the foam and RCC models for use in LS-DYNA.

  7. External and internal limitations in amplitude-modulation processing

    DEFF Research Database (Denmark)

    Ewert, Stephan; Dau, Torsten

    2004-01-01

    Three experiments are presented to explore the relative role of "external" signal variability and "internal" resolution limitations of the auditory system in the detection and discrimination of amplitude modulations (AM). In the first experiment, AM-depth discrimination performance was determined......-term average envelope power spectrum was held constant. The experiment examined the validity of a long-term average quantity as the decision variable, and the role of memory in experiments with frozen-noise maskers. The empirical results were compared to predictions obtained with two modulation...

  8. EXTERNAL ELEMENTS OF INTERCULTURAL MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Ruxandra GEORGESCU

    2017-12-01

    Full Text Available Because nowadays we attach a great importance to our look, this article wants to highlight certain aspects of intercultural management that are external to us, the personal label with which we "come into contact with the whole world” and also this article gives some suggestions that I want to consider for business success. As speakers of a language, we are both "producers" and "consumers" of it. In a sense, this is also the case for the dress code, the "language" of clothing: we dress in a certain way and this send messages to others; We perceive how others are dressed and so we receive messages from them. But there is no difference: we are not the ones who produce the signs. Beyond fashion, myths and motes, clothing, accessories, gesture, face expression, posture and body lines are the first elements that give visual identity to any person. In the business environment, as in the world of fashion, immediate visual identity is the one that generates the first impression.

  9. External plans for radiological emergency

    International Nuclear Information System (INIS)

    Suarez, G.; Vizuet G, J.; Benitez S, J.A.

    1999-01-01

    Since 1989, the National Institute of Nuclear Research in Mexico shares in the task of Food and Water Control corresponding to the FT-86 task force of External Plans for Radiological Emergency (PERE), in charge of the Veracruz Health Services. In the PERE preparation stage previous actions are necessary developed for the preparation and updating of this plan and the task organization with the purpose to maintaining standing and operable in any time and circumstance, the capability to response in the face of an emergency. This stage englobes activities which must be realized before to carry out the Plan as they are the specialized training of personnel which participates and the execution of exercises and simulacrums. Until 1998, training and exercises for this task had been realized under diverse possible sceneries but in conditions that simulated the presence of radioactive material. For this reason, it should be emphasized the training realized during the days 6th, 7th, 8th July, 1999, in the emergency planning zone of the Plan, which to carry out using radioactive material. The National Institute of Nuclear Research had in charge of the training. This work describes all the activities for the realization of this training. (Author)

  10. Clinical governance and external audit.

    Science.gov (United States)

    Glazebrook, S G; Buchanan, J G

    2001-01-01

    This paper describes a model of clinical governance that was developed at South Auckland Health during the period 1995 to 2000. Clinical quality and safety are core objectives. A multidisciplinary Clinical Board is responsible for the development and publicising of sound clinical policies together with monitoring the effects of their implementation on quality and safety. The Clinical Board has several committees, including an organization-wide Continuous Quality Improvement Committee to enhance the explicit nature of the quality system in terms of structure, staff awareness and involvement, and to develop the internal audit system. The second stream stems from the Chief Medical Officer and clinical directors in a clinical management sense. The Audit Committee of the Board of Directors covers both clinical and financial audit. The reporting lines back to that committee are described and the role of the external auditor of clinical standards is explained. The aim has been to create a supportive culture where quality initiatives and innovation can flourish, and where the emphasis is not on censure but improvement.

  11. Human Sound Externalization in Reverberant Environments

    DEFF Research Database (Denmark)

    Catic, Jasmina

    In everyday environments, listeners perceive sound sources as externalized. In listening conditions where the spatial cues that are relevant for externalization are not represented correctly, such as when listening through headphones or hearing aids, a degraded perception of externalization may...... occur. In this thesis, the spatial cues that arise from a combined effect of filtering due to the head, torso, and pinna and the acoustic environment were analysed and the impact of such cues for the perception of externalization in different frequency regions was investigated. Distant sound sources...... were simulated via headphones using individualized binaural room impulse responses (BRIRs). An investigation of the influence of spectral content of a sound source on externalization showed that effective externalization cues are present across the entire frequency range. The fluctuation of interaural...

  12. External Beam Radiation in Differentiated Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Salem Billan

    2016-01-01

    Full Text Available The treatment of differentiated thyroid carcinoma (DTC is surgery followed in some cases by adjuvant treatment, mostly with radioactive iodine (RAI. External beam radiotherapy (EBRT is less common and not a well-established treatment modality in DTC. The risk of recurrence depends on three major prognostic factors: extra-thyroid extension, patient’s age, and tumor with reduced iodine uptake. Increased risk for recurrence is a major factor in the decision whether to treat the patient with EBRT. Data about the use of EBRT in DTC are limited to small retrospective studies. Most series have demonstrated an increase in loco-regional control. The risk/benefit from giving EBRT requires careful patient selection. Different scoring systems have been proposed by different investigators and centers. The authors encourage clinicians treating DTC to become familiarized with those scoring systems and to use them in the management of different cases. The irradiated volume should include areas of risk for microscopic disease. Determining those areas in each case can be difficult and requires detailed knowledge of the surgery and pathological results, and also understanding of the disease-spreading pattern. Treatment with EBRT in DTC can be beneficial, and data support the use of EBRT in high-risk patients. Randomized controlled trials are needed for better confirmation of the role of EBRT.

  13. External dosimetry - Applications to radiation protection

    International Nuclear Information System (INIS)

    Faussot, Alain

    2011-01-01

    Dosimetry is the essential component of radiation protection. It allows to determine by calculation and measurement the absorbed dose value, i.e. the energy amounts deposited in matter by ionizing radiations. It deals also with the irradiation effects on living organisms and with their biological consequences. This reference book gathers all the necessary information to understand and master the external dosimetry and the metrology of ionizing radiations, from the effects of radiations to the calibration of radiation protection devices. The first part is devoted to physical dosimetry and allows to obtain in a rigorous manner the mathematical formalisms leading to the absorbed dose for different ionizing radiation fields. The second part presents the biological effects of ionizing radiations on living matter and the determination of a set of specific radiation protection concepts and data to express the 'risk' to develop a radio-induced cancer. The third part deals with the metrology of ionizing radiations through the standardized study of the methods used for the calibration of radiation protection equipments. Some practical exercises with their corrections are proposed at the end of each chapter

  14. Understanding diversity in impact and responses among HIV/AIDS ...

    African Journals Online (AJOL)

    AIDS-related illnesses on people's mind and spirit (the internal environment), and 2) the influence of institutional structures and processes (the external environment), in order to better understand 3) the actions taken by individuals and households ...

  15. Energy security externalities and fuel cycle comparisons

    International Nuclear Information System (INIS)

    Bohi, D.; Toman, M.

    1994-01-01

    Externalities related to 'energy security' may be one way in which the full social costs of energy use diverge from the market prices of energy commodities. Such divergences need to be included in reckoning the full costs of different fuel cycles. In this paper we critically examine potential externalities related to energy security and issues related to the measurement of 2 these externalities, in the context of fuel cycle comparisons

  16. Risk analysis of external radiation therapy

    International Nuclear Information System (INIS)

    Arvidsson, Marcus

    2011-09-01

    External radiation therapy is carried out via a complex treatment process in which many different groups of staff work together. Much of the work is dependent on and in collaboration with advanced technical equipment. The purpose of the research task has been to identify a process for external radiation therapy and to identify, test and analyze a suitable method for performing risk analysis of external radiation therapy

  17. Early discharge after external anal sphincter repair

    DEFF Research Database (Denmark)

    Rosenberg, J; Kehlet, H

    1999-01-01

    PURPOSE: The aim of this study was to describe an accelerated-stay program for repair of the external anal sphincter. METHODS: Twenty consecutive patients undergoing overlapping repair of the external anal sphincter were included in the study. Effect parameters were length of hospitalization....... CONCLUSION: We have described a safe accelerated-stay program (24 to 48 hours) for overlapping repair of external anal sphincter....

  18. Internal and External Readings of Same

    DEFF Research Database (Denmark)

    Hardt, Daniel

    2016-01-01

    is infelicitous in the absence of parallelism. Hardt and Mikkelsen propose an account that applies uniformly to internal and external readings; however, the evidence they present largely targets external readings – they don’t offer empirical evidence that clearly supports the uniform approach. Furthermore, Barker...... (2007) argues that internal readings must be treated differently than external readings. In this paper, I show that the parallelism effects observed by Hardt and Mikkelsen in fact apply to internal readings as well. This provides support for a uniform treatment of internal and external readings of same...

  19. Proceedings: National conference on environmental externalities

    International Nuclear Information System (INIS)

    1990-01-01

    This report is the proceedings of the National Conference on Environmental Externalities. A environmental externality is the environmental impact of a process or a plant that society must endure. It is a social cost and is paid, but not by the company who produced it or the company's customers who endure it. The main purpose of this report is to gather the many designs and ideas of how and why to internalize the externalities into the pricing systems of the public utility commissions, especially that of the electric utilities. Economic and sociological aspects of the internalization of these externalities are given in these proceedings. Individual papers are processed separately for databases. (MB)

  20. External dacryocystorhinostomy combined with mucosal grafting and magnetic resonance imaging

    International Nuclear Information System (INIS)

    Uehara, Fumiyuki; Ohba, Norio

    2002-01-01

    The purpose of this study was to facilitate understanding of the use of magnetic resonance imaging (MRI) in nasolacrimal obstructive diseases and to determine the indication for external dacryocystorhinostomy (DCR) combined with mucosal grafting. We retrospectively studied the correlation between MRI images and surgical findings in 13 consecutive patients with swollen lacrimal sacs because of obstruction of the nasolacrimal duct or lacrimal sac. They were treated at the Kagoshima University Hospital between June 1999 and May 2001. A simple procedure of external DCR was performed in 9 cases, and a procedure combined with mucosal grafting was performed in 4 cases (age range, 51-88 years). Surgical findings in the fibrous region of the lacrimal sac corresponded to the hyperintense signal on MRI T 1 -weighted (T1W) images, more remarkably after enhancement. Surgical findings in the granulomatous sac and proteinaceous contents corresponded to the isointense areas on T2W images. Cases with thin sac were treated by standard DCR, whereas cases with tick, fibrous and granulomatous sac were treated by external DCR combined with mucosal grafting. The MRI images provide a useful preoperative determination for indications of external DCR combined with mucosal grafting. (author)

  1. 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.

  2. 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.

  3. Measuring Long-Distance Romantic Relationships: A Validity Study

    Science.gov (United States)

    Pistole, M. Carole; Roberts, Amber

    2011-01-01

    This study investigated aspects of construct validity for the scores of a new long-distance romantic relationship measure. A single-factor structure of the long-distance romantic relationship index emerged, with convergent and discriminant evidence of external validity, high internal consistency reliability, and applied utility of the scores.…

  4. External proton and Li beams

    International Nuclear Information System (INIS)

    Schuff, Juan A.; Burlon, Alejandro A.; Debray, Mario E.; Kesque, Jose M.; Kreiner, Andres J.; Stoliar, Pablo A.; Naab, Fabian; Ozafran, Mabel J.; Vazquez, Monica E.; Perez de la Hoz, A.; Somacal, Hector; Valda, Alejandro; Canevas, S.; Ruffolo, M.; Tasat, D.R.; Muhlmann, M. C.

    2000-01-01

    In the frame of a feasibility study to introduce proton therapy in Argentina in a collaborative agreement between the Physics and Radiobiology Departments of the National Atomic Energy Commission or Argentina and the Centre de Protontherapie de Orsay, France, external proton and Li beams were produced at the TANDAR accelerator in Buenos Aires. The specific aim of this work was to start radiobiology studies on cell cultures and small laboratory animals. In particular we seek to determine here the relative biological effectiveness, RBE, for proton and Li beams as a function of energy for different tumor and normal cell lines. The 24 MeV proton beam was diffused using a 25 μm gold foil and extracted through a Kapton window to obtain a homogeneous field (constant to 95%) of about 7 cm in diameter. Measurements were carried out with quasi-monoenergetic beams (of 20.2 ± 0.07 MeV, 2.9 ± 0.10 MeV y 1.5 ± 0.1 MeV for protons and 21.4 ± 0.4 MeV for Lithium). Proton fluence and Bragg peaks were measured. The dose delivered in each case was monitored on-line with a calibrated transmission ionization chamber. Three cell lines PDV, PDVC 57 and V 79 (as a reference) were irradiated with γ-rays, proton and lithium beams with linear energy transfer (LET) from 2 to 100 keV/μm. RBE values in the range of 1.2-5.9 were obtained. In addition preliminary studies on chromosomal aberrations and viability of alveolar macrophages were carried out. (author)

  5. 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 Europ...... show that estimated damages due to the greenhouse effect are predominant, however, the uncertainty is high. The predominant damage at the local and regional level is related to emission of NOx, which results in effects on public health....... the use of a software package, EcoSence, having an environmental database at both a local and regional level including population, crops, building materials and forest. The system also incorporates two air transport models, allowing local and regional scale modelling. The results of the Danish case study...

  6. Semantic Borders and Incomplete Understanding.

    Science.gov (United States)

    Silva-Filho, Waldomiro J; Dazzani, Maria Virgínia

    2016-03-01

    In this article, we explore a fundamental issue of Cultural Psychology, that is our "capacity to make meaning", by investigating a thesis from contemporary philosophical semantics, namely, that there is a decisive relationship between language and rationality. Many philosophers think that for a person to be described as a rational agent he must understand the semantic content and meaning of the words he uses to express his intentional mental states, e.g., his beliefs and thoughts. Our argument seeks to investigate the thesis developed by Tyler Burge, according to which our mastery or understanding of the semantic content of the terms which form our beliefs and thoughts is an "incomplete understanding". To do this, we discuss, on the one hand, the general lines of anti-individualism or semantic externalism and, on the other, criticisms of the Burgean notion of incomplete understanding - one radical and the other moderate. We defend our understanding that the content of our beliefs must be described in the light of the limits and natural contingencies of our cognitive capacities and the normative nature of our rationality. At heart, anti-individualism leads us to think about the fact that we are social creatures, living in contingent situations, with important, but limited, cognitive capacities, and that we receive the main, and most important, portion of our knowledge simply from what others tell us. Finally, we conclude that this discussion may contribute to the current debate about the notion of borders.

  7. 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.

  8. Crossing boundaries : Involving external parties in innovation

    NARCIS (Netherlands)

    Slot, J.H.

    2013-01-01

    To improve the return on investments in innovation, firms increasingly open up their new product development (NPD) processes by inviting external parties to participate. This dissertation focuses on the involvement of three different types of external parties in the NPD process: suppliers,

  9. 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.

  10. School Improvement Processes and External Agency Roles.

    Science.gov (United States)

    Temkin, Sanford

    This paper discusses the improvement process used in schools to bring about change, as well as the influence of external agencies on improvement activity. It considers school district processes as they relate to improvement activity, the strategies and roles performed by external agencies, and the issues that might effect planning by an external…

  11. External Communities of Practice and Relational Capital

    Science.gov (United States)

    Dewhurst, Frank W.; Navarro, Juan G. Cegarra

    2004-01-01

    External communities of practice are groups formed by company clients and employees based on common interests, commitment, mutual trust and collaboration whose members regularly share knowledge and learning. This paper examines how external communities of practice contribute to the creation of relational capital through an empirical investigation…

  12. Black holes under external influence £

    Indian Academy of Sciences (India)

    KTF MFF UK

    Abstract. The work on black holes immersed in external fields is reviewed in both test-field ap- proximation and within exact solutions. In particular we pay attention to the effect of the expulsion of the flux of external fields across charged and rotating black holes which are approaching extremal states. Recently this effect has ...

  13. Forms of Spanking and Children's Externalizing Behaviors

    Science.gov (United States)

    Lansford, Jennifer E.; Wager, Laura B.; Bates, John E.; Pettit, Gregory S.; Dodge, Kenneth A.

    2012-01-01

    Research suggests that corporal punishment is related to higher levels of child externalizing behavior, but there has been controversy regarding whether infrequent, mild spanking predicts child externalizing or whether more severe and frequent forms of corporal punishment account for the link. Mothers rated the frequency with which they spanked…

  14. Wind power externalities: A meta-analysis

    NARCIS (Netherlands)

    Mattmann, M.; Logar, I.; Brouwer, R.

    2016-01-01

    This study presents the first quantitative meta-analysis of the non-market valuation literature on the external effects associated with wind power production. A data set of 60 observations drawn from 32 studies is constructed. The relative economic values of different types of externalities as well

  15. Examining the Assessment Literacy of External Examiners

    Science.gov (United States)

    Medland, Emma

    2015-01-01

    External scrutiny of higher education courses is evident globally, but the use of an external examiner from another institution for the purposes of quality assurance has been a distinguishing feature of UK higher education since the 1830s. However, the changing higher education context has led to mounting criticism of the system and the…

  16. On interaction with external fields. 1

    International Nuclear Information System (INIS)

    Polubarinov, I.V.

    1978-01-01

    An introduction into theory of interaction of any quantized charged field with arbitrary external time-dependent classical fields is exposed. Usual field operator terms are used. S-matrix is explicitly represented in an N-ordered form. Its matrix elements are treated, using a particle number operator formalism. Pair number distribution produced by external fields from vacuum is characterized

  17. Network Externality and Commercial Software Piracy

    OpenAIRE

    Sougata Poddar

    2005-01-01

    Contrary to the earlier findings under end-users piracy where the existence of strong network externality was shown to be a reason for allowing limited piracy, we find when the piracy is commercial in nature the optimal policy for the original software developer is to protect its product irrespective of the strength of network externality in the software users market.

  18. 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.

  19. New advances in solid state powder lasers: the effects of external seeding and external mirrors

    Science.gov (United States)

    Noginov, Mikhail A.; Noginova, Natalia E.; Egarievwe, Stephen U.; Wang, JaChing; Caulfield, H. John

    1999-01-01

    We have studied the effects of the external laser seeding and external mirrors on stimulated emission in powder lasers. The possibility of remove controlling of the powder laser emission has been demonstrated.

  20. External Tank - The Structure Backbone

    Science.gov (United States)

    Welzyn, Kenneth; Pilet, Jeffrey C.; Diecidue-Conners, Dawn; Worden, Michelle; Guillot, Michelle

    2011-01-01

    The External Tank forms the structural backbone of the Space Shuttle in the launch configuration. Because the tank flies to orbital velocity with the Space Shuttle Orbiter, minimization of weight is mandatory, to maximize payload performance. Choice of lightweight materials both for structure and thermal conditioning was necessary. The tank is large, and unique manufacturing facilities, tooling, handling, and transportation operations were required. Weld processes and tooling evolved with the design as it matured through several block changes, to reduce weight. Non Destructive Evaluation methods were used to assure integrity of welds and thermal protection system materials. The aluminum-lithium alloy was used near the end of the program and weld processes and weld repair techniques had to be refined. Development and implementation of friction stir welding was a substantial technology development incorporated during the Program. Automated thermal protection system application processes were developed for the majority of the tank surface. Material obsolescence was an issue throughout the 40 year program. The final configuration and tank weight enabled international space station assembly in a high inclination orbit allowing international cooperation with the Russian Federal Space Agency. Numerous process controls were implemented to assure product quality, and innovative proof testing was accomplished prior to delivery. Process controls were implemented to assure cleanliness in the production environment, to control contaminants, and to preclude corrosion. Each tank was accepted via rigorous inspections, including non-destructive evaluation techniques, proof testing, and all systems testing. In the post STS-107 era, the project focused on ascent debris risk reduction. This was accomplished via stringent process controls, post flight assessment using substantially improved imagery, and selective redesigns. These efforts were supported with a number of test programs to

  1. External conference: UNIVERSITE DE GENEVE

    CERN Multimedia

    2007-01-01

    Ecole de physique Département de physique nucléaire et corspusculaire 24, Quai Ernest-Ansermet
1211 GENEVE 4
Tél: (022) 379 62 73
Fax: (022) 379 69 92 Wednesday 26th September 2007 PARTICLE PHYSICS SEMINAR at 17.00 hrs - Stückelberg Auditorium Precision determinations of |Vcb| and |Vub| by Dr U. Phillip / University of Melbourne The success of the B factories has dramatically improved our understanding of CP violation. The search for clear signs of new physics through measurements of CP violation is limited by understanding of the CKM elements |Vub| and |Vcb|. Improvement of our knowledge of the least well known CKM parameter, |Vub|, therefore directly translates to a more stringent test of the Standard Model. The prodigious samples of B meson decays available at the B factories, along with advances in the theory involving semileptonic B decays, have been used to provide a determination of both, |Vcb| and the b-quark mass, with a precision of 1%, and bring the pr...

  2. Validity, Science and Educational Measurement

    Science.gov (United States)

    Goldstein, Harvey

    2015-01-01

    The term "validity" is one of the most important and one of the most debated concepts in educational measurement. In this paper, I argue that various different approaches can all be viewed from an associational perspective. I also argue that our understanding will be enhanced by adopting some basic ideas of scientific reasoning to the…

  3. Externalities of energy and atomic power

    International Nuclear Information System (INIS)

    2006-09-01

    Energy technology ensures not only energy supply but also has great impacts on society and environments. Economical value and effect evaluation alone doesn't mean appropriate so the evaluation of 'externalities' should be appreciated. In order to assess atomic power in this context, the Atomic Energy Society of Japan set up a research committee on 'externalities of energy and atomic power' from April 2002 to March 2006, whose activities were described in this report. In addition to environmental effects and environmental externalities, four areas were newly studied as follows: (1) biological effects of low dose rate exposure and externalities, (2) externalities as social/economical effects including stable supply and security, (3) energy technologies evaluation and (4) social choice and decision-making. (T. Tanaka)

  4. 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

  5. Shape understanding system machine understanding and human understanding

    CERN Document Server

    Les, Zbigniew

    2015-01-01

    This is the third book presenting selected results of research on the further development of the shape understanding system (SUS) carried out by authors in the newly founded Queen Jadwiga Research Institute of Understanding. In this book the new term Machine Understanding is introduced referring to a new area of research aiming to investigate the possibility of building machines with the ability to understand. It is presented that SUS needs to some extent mimic human understanding and for this reason machines are evaluated according to the rules applied for the evaluation of human understanding. The book shows how to formulate problems and how it can be tested if the machine is able to solve these problems.    

  6. Key External Influences Affecting Consumers’ Decisions Regarding Food

    Science.gov (United States)

    Martínez-Ruiz, María Pilar; Gómez-Cantó, Carmen María

    2016-01-01

    Among the numerous internal and external forces that compete for consumers’ attention in the context in which they buy their food, this paper will seek to provide a review of the most important external influences, such as the variables related to food itself. To this end, in addition to the food attributes traditionally identified in fields such as consumer behavior, it will give special consideration to the classification of food values. Although the influence of these variables on consumer decisions depends on the individual, analyzing them will undoubtedly increase understanding of consumers’ decisions. Additionally, identifying and describing these variables will enable subsequent research on how they influence both consumer behavior and other key outcomes for producers, manufacturers, and retailers in the food industry, such as satisfaction, trust, and loyalty. PMID:27803686

  7. 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.

  8. 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

  9. Congenital malformations of the external and middle ear

    Energy Technology Data Exchange (ETDEWEB)

    Koesling, S. [University of Halle, Department of Diagnostic Radiology (Germany)], E-mail: sabrina.koesling@medizin.uni-halle.de; Omenzetter, M. [University of Halle, Department of Diagnostic Radiology (Germany); Bartel-Friedrich, S. [University of Halle, Department of Otorhinolaryngology - Head and Neck Surgery, Section of Phoniatrics and Pedaudiology (Germany)

    2009-02-15

    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.

  10. 3D-printed external light trap for solar cells.

    Science.gov (United States)

    van Dijk, Lourens; Paetzold, Ulrich W; Blab, Gerhard A; Schropp, Ruud E I; di Vece, Marcel

    2016-05-01

    We present a universally applicable 3D-printed external light trap for enhanced absorption in solar cells. The macroscopic external light trap is placed at the sun-facing surface of the solar cell and retro-reflects the light that would otherwise escape. The light trap consists of a reflective parabolic concentrator placed on top of a reflective cage. Upon placement of the light trap, an improvement of 15% of both the photocurrent and the power conversion efficiency in a thin-film nanocrystalline silicon (nc-Si:H) solar cell is measured. The trapped light traverses the solar cell several times within the reflective cage thereby increasing the total absorption in the cell. Consequently, the trap reduces optical losses and enhances the absorption over the entire spectrum. The components of the light trap are 3D printed and made of smoothened, silver-coated thermoplastic. In contrast to conventional light trapping methods, external light trapping leaves the material quality and the electrical properties of the solar cell unaffected. To explain the theoretical operation of the external light trap, we introduce a model that predicts the absorption enhancement in the solar cell by the external light trap. The corresponding calculated path length enhancement shows good agreement with the empirically derived value from the opto-electrical data of the solar cell. Moreover, we analyze the influence of the angle of incidence on the parasitic absorptance to obtain full understanding of the trap performance. © 2015 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons, Ltd.

  11. Hyperglycemia and externalizing behavior in children with type 1 diabetes.

    Science.gov (United States)

    McDonnell, Ciara M; Northam, Elisabeth A; Donath, Susan M; Werther, George A; Cameron, Fergus J

    2007-09-01

    Ancedotally, parents report behavioral changes in their diabetic children who have fluctuating blood glucose levels. This study aimed to test associations between intercurrent glycemia and child behavior in an ambulant setting. Prepubertal children attending the Royal Children's Hospital, Melbourne, Australia, with type 1 diabetes received glycemic assessment and simultaneous behavioral assessment on two occasions 6 months apart. Subjects wore a continuous glucose monitor over a 72-h period, and parents completed the Behavior Assessment System for Children at the two study time points. There was a high correlation between intra-individual externalizing and internalizing behavior scores (r = 0.88, P behavior score (beta = 1.7 [95% CI 0.6-2.8], adjusted r(2) = 0.088). Percentage of time in the normal (r = -0.2 [-0.3 to -0.5], adjusted r(2) = 0.068) and high (r = 0.2 [0.07-0.3], adjusted r(2) = 0.089) glycemic ranges were significantly associated with the mean externalizing behavior score. For every 5% increase in time in the normal glycemic range, there was a decrease in the externalizing behavior score of 1.0, and for every 5% increase in time in the high glycemic range there was an increase in the externalizing behavior score of 1.0. There was no significant association between MBG and the mean internalizing behavior score. Externalizing behaviors were associated with intercurrent glycemic status. These findings underscore the importance of understanding the mechanisms of this association and how it might impact ultimate diabetes outcomes.

  12. Evaluations of the Third Kind: External Evaluations of External Quality Assurance Agencies

    Science.gov (United States)

    Szanto, Tibor R.

    2005-01-01

    This paper reviews several cases of external evaluations of external quality assurance (EQA) agencies. The characteristics, methodology and findings of six such evaluations from three continents are discussed and similarities and differences are analysed. The lessons drawn from these six cases show that external evaluation of agencies is a…

  13. 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

  14. 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 ...

  15. Use of Automated External Defibrillators

    Energy Technology Data Exchange (ETDEWEB)

    Gregory K Christensen

    2009-02-01

    In an effort to improve survival from cardiac arrest, the American Heart Association (AHA) has promoted the Chain of Survival concept, describing a sequence of prehospital steps that result in improved survival after sudden cardiac arrest. These interventions include immediate deployment of emergency medical services, prompt cardiopulmonary resuscitation, early defibrillation when indicated, and early initiation of advanced medical care. Early defibrillation has emerged as the most important intervention with survival decreasing by 10% with each minute of delay in defibrillation. Ventricular Fibrillation (VF) is a condition in which there is uncoordinated contraction of the heart cardiac muscle of the ventricles in the heart, making them tremble rather than contract properly. VF is a medical emergency and if the arrhythmia continues for more than a few seconds, blood circulation will cease, and death can occur in a matter of minutes. During VF, contractions of the heart are not synchronized, blood flow ceases, organs begin to fail from oxygen deprivation and within 10 minutes, death will occur. When VF occurs, the victim must be defibrillated in order to establish the heart’s normal rhythm. On average, the wait for an ambulance in populated areas of the United States is about 11 minutes. In view of these facts, the EFCOG Electrical Safety Task Group initiated this review to evaluate the potential value of deployment and use of automated external defibrillators (AEDs) for treatment of SCA victims. This evaluation indicates the long term survival benefit to victims of SCA is high if treated with CPR plus defibrillation within the first 3-5 minutes after collapse. According to the American Heart Association (AHA), survival rates as high as 74% are possible if treatment and defibrillation is performed in the first 3 minutes. In contrast survival rates are only 5% where no AED programs have been established to provide prompt CPR and defibrillation. ["CPR statistics

  16. Estimation of Externalities for Juragua Nuclear Project

    International Nuclear Information System (INIS)

    Mora, H. R.; Carbonell, L. T.

    2002-01-01

    Estimation of externalities allows taking into account environmental impacts due to any activity in total costs calculation. In the present work, the external costs of electricity generation from nuclear energy were calculated considering three scenarios: normal operation (routine releases), accident situation and solid waste disposal. A comparison between these results and those obtained for electricity generation from fossil fuels was made. IAEA proposals of Simplified methodologies were used for externality calculations. The Juragua project was selected as a study case; it is based in two energetic blocks both PWR, VVER 440/318 type with a plant capacity of 417 MWe each. Four impact ways were considered for all scenarios: (1) Inhalation of radionuclides in the air, (2) External irradiation from radionuclides immersed in clouds, (3) External irradiation from deposited radionuclides and (4) Ingestion of radionuclides in agricultural products. Besides, two impact categories (local and regional) for all scenarios were considered. The total cost of externalities was 0.01425 c/kWh, value smaller than the one obtained for electricity generation from fossil fuel (0.256 c/kWh). For the normal operation scenario, the external cost calculated was 0.00112 c/kWh, for accident situation 0.01103 c/kWh, and for the solid wastes management scenario 0.0021 c/kWh. The high value obtained for solid waste disposal scenario is due to repository placement features. (author)

  17. The Role of Maternal Depression on Treatment Outcome for Children with Externalizing Behavior Problems

    OpenAIRE

    van Loon, Linda M. A.; Granic, Isabela; Engels, Rutger 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 variability in treatment outcome. Children with externalizing behavioral problems and their parents were recruited from combined Parent Management Training and Cognitive-Behavioral programs in "real-world...

  18. The impact of external pressure and sustainable management practices on manufacturing performance and environmental outcomes

    OpenAIRE

    Adebanjo, Dotun; Teh, Pei-Lee; Ahmed, Pervaiz K.

    2016-01-01

    Purpose: The study investigates the direct effect of external pressure on environmental outcomes and manufacturing performance and examines the mediating effect of sustainable management practice.\\ud \\ud Design/methodology/approach: This study draws upon Institutional Theory and Resource Based View to understand how factors such as external pressure and sustainable management relate with environmental outcomes and manufacturing performance. The model specifies previously unexplored direct and...

  19. Assembly of Superparamagnetic Filaments in External Field.

    Science.gov (United States)

    Wei, Jiachen; Song, Fan; Dobnikar, Jure

    2016-09-13

    We present a theoretical and simulation study of anchored magneto-elastic filaments in external magnetic field. The filaments are composed of a mixture of superparamagnetic and nonmagnetic colloidal beads interlinked with elastic springs. We explore the steady-state structures of filaments with various composition and bending rigidity subject to external magnetic field parallel to the surface. The interplay of elastic and induced magnetic interactions results in a rich phase behavior with morphologies reminiscent of macromolecular folding: bent filaments, loops, sheets, helicoids, and other collapsed structures. Our results provide new insights into the design of hierarchically assembled supramolecular structures with controlled response to external stimuli.

  20. Environment and externalization; Environnement et externalisation

    Energy Technology Data Exchange (ETDEWEB)

    Kremlis, G.; Renaud, R. [Association francaise des ingenieurs et techniciens de l' environnement, AFITE, 75 - Paris (France); Touron, M. [Veritas, 75 - Paris (France)] [and others

    2001-07-01

    This document presents the discussions of the 16 may 2000, concerning the externalization and the environment and proposes to answer the following questions: is the externalization a new strategy to better perceive, hopeful engineering department, the technological risks problems, the environment or the land pollution? Does the externalization allow a better organization of the enterprise? To analyse the situation, the document presents the white book of the environmental liability, the administration point of view, some enterprises examples and the importance of the environmental management. (A.L.B.)

  1. Relaxed plasmas in external magnetic fields

    International Nuclear Information System (INIS)

    Spies, G.O.; Li, J.

    1991-08-01

    The well-known theory of relaxed plasmas (Taylor states) is extended to external magnetic fields whose field lines intersect the conducting toroidal boundary. Application to an axially symmetric, large-aspect-ratio torus with circular cross section shows that the maximum pinch ratio, and hence the phenomenon of current saturation, is independent of the external field. The relaxed state is explicitly given for an external octupole field. In this case, field reversal is inhibited near parts of the boundary if the octupole generates magnetic x-points within the plasma. (orig.)

  2. Internal Versus External Knowledge Sourcing Of Subsidiaries

    DEFF Research Database (Denmark)

    Gammelgaard, Jens; Pedersen, Torben

    2003-01-01

    between the external and internal networks. However, newer organizationalforms, like the concept of the `differentiated MNC', imply a relatively smooth flow of knowledgeinside the MNC, indicating that we should not expect an organizational trade-off between internaland external sources. The subsidiary...... countries (the Centre of ExcellenceProject). In fact, the results show that, to a certain extent, there is no dilemma between asubsidiary's knowledge development based on both internal, and external knowledge sources.However, the results also show a bell-shaped relationship between the use of internal...

  3. Concurrent sourcing and external supplier opportunism

    DEFF Research Database (Denmark)

    Mols, Niels Peter

    costs of opportunism are determined as a product of four factors. The four factors are: likelihood of discovering supplier opportunism, buyer’s internalized quantity as reaction to supplier opportunism, asset specificity of external supplier’s investments, and multiplicator effects. Each......When a firm simultaneously makes and buys the same components then the firm uses concurrent sourcing. This paper presents an agency model for explaining how and when concurrent sourcing reduces the likelihood of external supplier opportunism. In the proposed model, the external supplier’s expected...

  4. Hazards related to external flooding

    International Nuclear Information System (INIS)

    1984-04-01

    RFS or Regles Fondamentales de Surete (Basic Safety Rules) applicable to certain types of nuclear facilities lay down requirements with which compliance, for the type of facilities and within the scope of application covered by the RFS, is considered to be equivalent to compliance with technical French regulatory practice. The object of the RFS is to take advantage of standardization in the field of safety, while allowing for technical progress in that field. They are designed to enable the operating utility and contractors to know the rules pertaining to various subjects which are considered to be acceptable by the Service Central de Surete des Installations Nucleaires, or the SCSIN (Central Department for the Safety of Nuclear Facilities). These RFS should make safety analysis easier and lead to better understanding between experts and individuals concerned with the problems of nuclear safety. The SCSIN reserves the right to modify, when considered necessary, any RFS and specify, if need be, the terms under which a modification is deemed retroactive. This RFS is intended to give state-of-the-art definitions of: - an acceptable method to determine water levels to be used in flood design of a facility - facility design principles required to meet the principles above

  5. 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.

  6. [Intention and Current Situation of External Quality Assurance Program Supervised by the Japan Medical Association].

    Science.gov (United States)

    Maekawa, Masato

    2015-08-01

    The Japan Medical Association (JMA) has provided the external quality assurance (EQA) program in clinical laboratory testing. About 3,200 clinical laboratories recently participated. The EQA program shows us the current situation of clinical laboratory testing as well as the evaluation of each clinical laboratory. Moreover, it aims for the harmonization of clinical laboratory testing, resulting in common objective data, common diagnostic criteria, and medical standardization. The EQA program examines and educates regarding the measurement method (JSCC transferable method or not), analyzer, reagent, traceability, calibrator, unit, temperature, cut-off value, and lower decision limit, in order to strengthen the foundation of clinical laboratories. Clinical laboratory testing consists of pre-pre-analytical, pre-analytical, analytical, post-analytical, and post-post-analytical phases. The EQA program investigates not only the analytical phase but also a part of pre-analytical and post-analytical phases. We should know that the role of a clinical laboratory is not just analysis or measurement. It is truly expected that we will earnestly participate in the EQA program to check the validity of our own ordinary and not champion results, and to understand the harmonization of total laboratory testing phases.

  7. Proceedings: National conference on environmental externalities

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    This report is the proceedings of the National Conference on Environmental Externalities. A environmental externality is the environmental impact of a process or a plant that society must endure. It is a social cost and is paid, but not by the company who produced it or the company`s customers who endure it. The main purpose of this report is to gather the many designs and ideas of how and why to internalize the externalities into the pricing systems of the public utility commissions, especially that of the electric utilities. Economic and sociological aspects of the internalization of these externalities are given in these proceedings. Individual papers are processed separately for databases. (MB)

  8. Which Agglomeration Externalities Matter Most and Why?

    NARCIS (Netherlands)

    de Groot, Henri L.F.; Poot, Jacques; Smit, Martijn J.

    2016-01-01

    This paper revisits the ongoing discussion on the importance of agglomeration externalities – specifically specialization, diversity and competition effects – that may contribute to innovation, productivity and urban employment growth. Previous meta‐analyses suggested that the evidence on

  9. Which Agglomeration Externalities Matter Most and Why?

    NARCIS (Netherlands)

    de Groot, H.L.F.; Poot, J.; Smit, M.J.

    2016-01-01

    This paper revisits the ongoing discussion on the importance of agglomeration externalities – specifically specialization, diversity and competition effects – that may contribute to innovation, productivity and urban employment growth. Previous meta-analyses suggested that the evidence on

  10. Partial breast radiation therapy - external beam

    Science.gov (United States)

    Carcinoma of the breast - partial radiation therapy; Partial external beam radiation - breast; Intensity-modulated radiation therapy - breast cancer; IMRT - breast cancer WBRT; Adjuvant partial breast - IMRT; APBI - IMRT; ...

  11. The strategic significance of negative externalities.

    Science.gov (United States)

    2012-12-01

    Negative externalities have competitive relevance in a market when they have selective impacts as, for : example, when a product in use imposes greater costs on consumers of rival products than on other people. : Because managers have discretion ...

  12. Macroeconomic Adjustment in Armenia: The Role of External Factors

    Directory of Open Access Journals (Sweden)

    Bas van AARLE

    2010-05-01

    Full Text Available 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 management and the inflow of remittances in the Armenian economy

  13. Servitization in China via an External Service Partner Network

    DEFF Research Database (Denmark)

    Raja, Jawwad; Frandsen, Thomas

    2016-01-01

    Previous research has predominately focused on the servitization strategies of Western manufacturers in advanced economies, neglecting the potential in those which are emerging, such as China. This paper explores the role of the external service partner network of a European manufacturer providing...... services in China in order to develop a better understanding of the challenges. An in-depth multiple case study approach was taken to examine the parent company, its subsidiary in China and the related service partner network. Data collection involved all three actors and took place in Denmark and China...

  14. Multiple Environmental Externalities and Manure Management Policy

    OpenAIRE

    Key, Nigel D.; Kaplan, Jonathan D.

    2007-01-01

    This paper considers the economic and environmental implications of regulating water and air nitrogen emissions under single and multi-environmental media policies in the U.S. hog industry. We examine tradeoffs from policies designed to correct an externality in one medium, when there are multiple environmental externalities. We separately and jointly analyze: (a) nitrogen land application restrictions consistent with recently adopted EPA requirements under the Clean Water Act, and (b) hypoth...

  15. Integrating Building Functions into Massive External Walls

    Directory of Open Access Journals (Sweden)

    Ahmed Hisham Hafez

    2017-11-01

    Full Text Available Well into the twentieth century, brick and stone were the materials used. Bricklaying and stonemasonry were the construction technologies employed for the exterior walls of virtually all major structures. However, with the rise in quality of life, the massive walls alone became incapable of fulfilling all the developed needs. Adjacent systems and layers had then to be attached to the massive layer. Nowadays, the external wall is usually composed of a layered construction. Each external wall function is usually represented by a separate layer or system. The massive layer of the wall is usually responsible for the load-bearing function. Traditional massive external walls vary in terms of their external appearance, their composition and attached layers. However, their design and construction process is usually a repeated process. It is a linear process where each discipline is concerned with a separate layer or system. These disciplines usually take their tasks away and bring them back to be re-integrated in a layered manner. New massive technologies with additional function have recently become available. Such technologies can provide the external wall with other functions in addition to its load-bearing function. The purpose of this research is to map the changes required to the traditional design and construction process when massive technologies with additional function are applied in external walls. Moreover, the research aims at assessing the performance of massive solutions with additional function when compared to traditional solutions in two different contexts, the Netherlands and Egypt. Through the analysis of different additional function technologies in external walls, a guidance scheme for different stakeholders is generated. It shows the expected process changes as related to the product level and customization level. Moreover, the research concludes that the performance of additional insulating technologies, and specifically

  16. Road Damage Externalities and Road User Charges.

    OpenAIRE

    Newbery, David M

    1988-01-01

    Vehicles damage roads and, thus, increase road repair costs and create a road damage externality by raising the operating costs of subsequent vehicles. The main result is that if periodic road maintenance is condition responsive and if all road damage is attributable to traffic, then, in steady state with zero traffic growth, the average road damage externality is zero a nd the appropriate road damage charge is the average maintenance cost. Where weather accounts for some road damage, the roa...

  17. External cost assessment for nuclear fuel cycle

    International Nuclear Information System (INIS)

    Park, Byung Heung; Ko, Won Il

    2015-01-01

    Nuclear power is currently the second largest power supply method in Korea and the number of nuclear power plants are planned to be increased as well. However, clear management policy for spent fuels generated from nuclear power plants has not yet been established. The back-end fuel cycle, associated with nuclear material flow after nuclear reactors is a collection of technologies designed for the spent fuel management and the spent fuel management policy is closely related with the selection of a nuclear fuel cycle. Cost is an important consideration in selection of a nuclear fuel cycle and should be determined by adding external cost to private cost. Unlike the private cost, which is a direct cost, studies on the external cost are focused on nuclear reactors and not at the nuclear fuel cycle. In this research, external cost indicators applicable to nuclear fuel cycle were derived and quantified. OT (once through), DUPIC (Direct Use of PWR SF in CANDU), PWR-MOX (PWR PUREX reprocessing), and Pyro-SFR (SFR recycling with pyroprocessing) were selected as nuclear fuel cycles which could be considered for estimating external cost in Korea. Energy supply security cost, accident risk cost, and acceptance cost were defined as external cost according to precedent and estimated after analyzing approaches which have been adopted for estimating external costs on nuclear power generation

  18. 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...

  19. 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.

  20. 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.