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Sample records for reliability reproducibility amstar

  1. Inter-rater reliability of AMSTAR is dependent on the pair of reviewers.

    Science.gov (United States)

    Pieper, Dawid; Jacobs, Anja; Weikert, Beate; Fishta, Alba; Wegewitz, Uta

    2017-07-11

    Inter-rater reliability (IRR) is mainly assessed based on only two reviewers of unknown expertise. The aim of this paper is to examine differences in the IRR of the Assessment of Multiple Systematic Reviews (AMSTAR) and R(evised)-AMSTAR depending on the pair of reviewers. Five reviewers independently applied AMSTAR and R-AMSTAR to 16 systematic reviews (eight Cochrane reviews and eight non-Cochrane reviews) from the field of occupational health. Responses were dichotomized and reliability measures were calculated by applying Holsti's method (r) and Cohen's kappa (κ) to all potential pairs of reviewers. Given that five reviewers participated in the study, there were ten possible pairs of reviewers. Inter-rater reliability varied for AMSTAR between r = 0.82 and r = 0.98 (median r = 0.88) using Holsti's method and κ = 0.41 and κ = 0.69 (median κ = 0.52) using Cohen's kappa and for R-AMSTAR between r = 0.77 and r = 0.89 (median r = 0.82) and κ = 0.32 and κ = 0.67 (median κ = 0.45) depending on the pair of reviewers. The same pair of reviewers yielded the highest IRR for both instruments. Pairwise Cohen's kappa reliability measures showed a moderate correlation between AMSTAR and R-AMSTAR (Spearman's ρ =0.50). The mean inter-rater reliability for AMSTAR was highest for item 1 (κ = 1.00) and item 5 (κ = 0.78), while lowest values were found for items 3, 8, 9 and 11, which showed only fair agreement. Inter-rater reliability varies widely depending on the pair of reviewers. There may be some shortcomings associated with conducting reliability studies with only two reviewers. Further studies should include additional reviewers and should probably also take account of their level of expertise.

  2. Reliability versus reproducibility

    International Nuclear Information System (INIS)

    Lautzenheiser, C.E.

    1976-01-01

    Defect detection and reproducibility of results are two separate but closely related subjects. It is axiomatic that a defect must be detected from examination to examination or reproducibility of results is very poor. On the other hand, a defect can be detected on each of subsequent examinations for higher reliability and still have poor reproducibility of results

  3. Systematic review found AMSTAR, but not R(evised)-AMSTAR, to have good measurement properties.

    Science.gov (United States)

    Pieper, Dawid; Buechter, Roland Brian; Li, Lun; Prediger, Barbara; Eikermann, Michaela

    2015-05-01

    To summarize all available evidence on measurement properties in terms of reliability, validity, and feasibility of the Assessment of Multiple Systematic Reviews (AMSTAR) tool, including R(evised)-AMSTAR. MEDLINE, EMBASE, Psycinfo, and CINAHL were searched for studies containing information on measurement properties of the tools in October 2013. We extracted data on study characteristics and measurement properties. These data were analyzed following measurement criteria. We included 13 studies, four of them were labeled as validation studies. Nine articles dealt with AMSTAR, two articles dealt with R-AMSTAR, and one article dealt with both instruments. In terms of interrater reliability, most items showed a substantial agreement (>0.6). The median intraclass correlation coefficient (ICC) for the overall score of AMSTAR was 0.83 (range 0.60-0.98), indicating a high agreement. In terms of validity, ICCs were very high with all but one ICC lower than 0.8 when the AMSTAR score was compared with scores from other tools. Scoring AMSTAR takes between 10 and 20 minutes. AMSTAR seems to be reliable and valid. Further investigations for systematic reviews of other study designs than randomized controlled trials are needed. R-AMSTAR should be further investigated as evidence for its use is limited and its measurement properties have not been studied sufficiently. In general, test-retest reliability should be investigated in future studies. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Comparison of methodological quality rating of systematic reviews on neuropathic pain using AMSTAR and R-AMSTAR.

    Science.gov (United States)

    Dosenovic, Svjetlana; Jelicic Kadic, Antonia; Vucic, Katarina; Markovina, Nikolina; Pieper, Dawid; Puljak, Livia

    2018-05-08

    Systematic reviews (SRs) in the field of neuropathic pain (NeuP) are increasingly important for decision-making. However, methodological flaws in SRs can reduce the validity of conclusions. Hence, it is important to assess the methodological quality of NeuP SRs critically. Additionally, it remains unclear which assessment tool should be used. We studied the methodological quality of SRs published in the field of NeuP and compared two assessment tools. We systematically searched 5 electronic databases to identify SRs of randomized controlled trials of interventions for NeuP available up to March 2015. Two independent reviewers assessed the methodological quality of the studies using the Assessment of Multiple Systematic Reviews (AMSTAR) and the revised AMSTAR (R-AMSTAR) tools. The scores were converted to percentiles and ranked into 4 grades to allow comparison between the two checklists. Gwet's AC1 coefficient was used for interrater reliability assessment. The 97 included SRs had a wide range of methodological quality scores (AMSTAR median (IQR): 6 (5-8) vs. R-AMSTAR median (IQR): 30 (26-35)). The overall agreement score between the 2 raters was 0.62 (95% CI 0.39-0.86) for AMSTAR and 0.62 (95% CI 0.53-0.70) for R-AMSTAR. The 31 Cochrane systematic reviews (CSRs) were consistently ranked higher than the 66 non-Cochrane systematic reviews (NCSRs). The analysis of individual domains showed the best compliance in a comprehensive literature search (item 3) on both checklists. The results for the domain that was the least compliant differed: conflict of interest (item 11) was the item most poorly reported on AMSTAR vs. publication bias assessment (item 10) on R-AMSTAR. A high positive correlation between the total AMSTAR and R-AMSTAR scores for all SRs, as well as for CSRs and NCSRs, was observed. The methodological quality of analyzed SRs in the field of NeuP was not optimal, and CSRs had a higher quality than NCSRs. Both AMSTAR and R-AMSTAR tools produced comparable

  5. Reproducibility and Reliability of Repeated Quantitative Fluorescence Angiography

    DEFF Research Database (Denmark)

    Nerup, Nikolaj; Knudsen, Kristine Bach Korsholm; Ambrus, Rikard

    2017-01-01

    INTRODUCTION: When using fluorescence angiography (FA) in perioperative perfusion assessment, repeated measures with re-injections of fluorescent dye (ICG) may be required. However, repeated injections may cause saturation of dye in the tissue, exceeding the limit of fluorescence intensity...... that the camera can detect. As the emission of fluorescence is dependent of the excitatory light intensity, reduction of this may solve the problem. The aim of the present study was to investigate the reproducibility and reliability of repeated quantitative FA during a reduction of excitatory light....

  6. Dental Students' Use of AMSTAR to Critically Appraise Systematic Reviews.

    Science.gov (United States)

    Teich, Sorin T; Heima, Masahiro; Lang, Lisa

    2015-09-01

    The idea of basing clinical procedures upon evidence gathered by observation is less than 200 years old, with the first set of evidence-based position papers dating back only to the early 1970s. The relationship between evidence-based education and health outcomes is difficult to test and may be indirect, but teaching critical appraisal skills may be beneficial in developing knowledge. Systematic reviews have a central role in the process of clinical decision making in practice and therefore should be of high quality, following a rigorous protocol that can be evaluated with validated tools. The aim of this study was to assess how dental students utilized the Assessment of Multiple Systematic Reviews (AMSTAR) appraisal tool to evaluate systematic reviews in the context of a treatment planning course. During the in-class final exam, students were required to appraise the quality of a systematic review and to justify their answers. Of the 74 third-year students who took the exam, 100% answered all questions on the AMSTAR form. The mean number of correct answers was nine (SD=1.047, Min=6, Max=10), with no student providing all 11 correct answers. The fact that nearly 90% of the students provided eight or more correct answers suggests that AMSTAR can be used by students to evaluate the methodological quality of systematic reviews. It also was evident that although the AMSTAR tool requires less than 15 minutes to complete an evaluation, using it requires extensive training and repetition to achieve consistent and reliable results.

  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. Reliability and reproducibility analysis of the AOSpine thoracolumbar spine injury classification system by Chinese spinal surgeons.

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    Cheng, Jie; Liu, Peng; Sun, Dong; Qin, Tingzheng; Ma, Zikun; Liu, Jingpei

    2017-05-01

    The objective of this study was to analyze the interobserver reliability and intraobserver reproducibility of the new AOSpine thoracolumbar spine injury classification system in young Chinese orthopedic surgeons with different levels of experience in spinal trauma. Previous reports suggest that the new AOSpine thoracolumbar spine injury classification system demonstrates acceptable interobserver reliability and intraobserver reproducibility. However, there are few studies in Asia, especially in China. The AOSpine thoracolumbar spine injury classification system was applied to 109 patients with acute, traumatic thoracolumbar spinal injuries by two groups of spinal surgeons with different levels of clinical experience. The Kappa coefficient was used to determine interobserver reliability and intraobserver reproducibility. The overall Kappa coefficient for all cases was 0.362, which represents fair reliability. The Kappa statistic was 0.385 for A-type injuries and 0.292 for B-type injuries, which represents fair reliability, and 0.552 for C-type injuries, which represents moderate reliability. The Kappa coefficient for intraobserver reproducibility was 0.442 for A-type injuries, 0.485 for B-type injuries, and 0.412 for C-type injuries. These values represent moderate reproducibility for all injury types. The raters in Group A provided significantly better interobserver reliability than Group B (P < 0.05). There were no between-group differences in intraobserver reproducibility. This study suggests that the new AO spine injury classification system may be applied in day-to-day clinical practice in China following extensive training of healthcare providers. Further prospective studies in different healthcare providers and clinical settings are essential for validation of this classification system and to assess its utility.

  9. Evaluation of reproducibility and reliability of 3D soft tissue analysis using 3D stereophotogrammetry.

    NARCIS (Netherlands)

    Plooij, J.M.; Swennen, G.R.J.; Rangel, F.A.; Maal, T.J.J.; Schutyser, F.A.C.; Bronkhorst, E.M.; Kuijpers-Jagtman, A.M.; Berge, S.J.

    2009-01-01

    In 3D photographs the bony structures are neither available nor palpable, therefore, the bone-related landmarks, such as the soft tissue gonion, need to be redefined. The purpose of this study was to determine the reproducibility and reliability of 49 soft tissue landmarks, including newly defined

  10. Reproducibility and reliability of repeated semen analyses in male partners of subfertile couples

    NARCIS (Netherlands)

    Leushuis, Esther; van der Steeg, Jan Willem; Steures, Pieternel; Repping, Sjoerd; Bossuyt, Patrick M. M.; Blankenstein, Marinus A.; Mol, Ben Willem J.; van der Veen, Fulco; Hompes, Peter G. A.

    2010-01-01

    Objective: To determine the precise degree of variability that is represented by the reproducibility and reliability of semen analysis. The general assumption is that semen analyses need to be repeated because of a high degree of within-individual variability. However, the precise degree of

  11. A national drug related problems database: evaluation of use in practice, reliability and reproducibility

    DEFF Research Database (Denmark)

    Kjeldsen, Lene Juel; Birkholm, Trine; Fischer, Hanne Lis

    2014-01-01

    Background A drug related problems database (DRP-database) was developed on request by clinical pharmacists. The information from the DRP-database has only been used locally e.g. to identify focus areas and to communicate identified DRPs to the hospital wards. Hence the quality of the data...... by clinical pharmacists with categorization performed by the project group. Reproducibility was explored by re-categorization of a sample of existing records in the DRP-database by two project group members individually. Main outcome measures Observed proportion of agreement and Fleiss' kappa as measures...... reliability study of 34 clinical pharmacists showed high inter-rater reliability with the project group (Fleiss' kappa = 0.79 with 95 % CI (0.70; 0.88)), and the reproducibility study also documented high inter-rater reliability of a sample of 379 records from the DRP-database re-categorized by two project...

  12. Analysis of the reliability and reproducibility of goniometry compared to hand photogrammetry

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    de Carvalho, Rosana Martins Ferreira; Mazzer, Nilton; Barbieri, Claudio Henrique

    2012-01-01

    Objective: To evaluate the intra- and inter-examiner reliability and reproducibility of goniometry in relation to photogrammetry of hand, comparing the angles of thumb abduction, PIP joint flexion of the II finger and MCP joint flexion of the V finger. Methods: The study included 30 volunteers, who were divided into three groups: one group of 10 physiotherapy students, one group of 10 physiotherapists, and a third group of 10 therapists of the hand. Each examiner performed the measurements on the same hand mold, using the goniometer followed by two photogrammetry software programs; CorelDraw® and ALCimagem®. Results: The results revealed that the groups and the methods proposed presented inter-examiner reliability, generally rated as excellent (ICC 0.998 I.C. 95% 0.995 - 0.999). In the intra-examiner evaluation, an excellent level of reliability was found between the three groups. In the comparison between groups for each angle and each method, no significant differences were found between the groups for most of the measurements. Conclusion: Goniometry and photogrammetry are reliable and reproducible methods for evaluating measurements of the hand. However, due to the lack of similar references, detailed studies are needed to define the normal parameters between the methods in the joints of the hand. Level of Evidence II, Diagnostic Study. PMID:24453594

  13. Reliability and reproducibility of disc-foveal angle measurements by non-mydriatic fundus photography.

    Science.gov (United States)

    Le Jeune, Caroline; Chebli, Fayçal; Leon, Lorette; Anthoine, Emmanuelle; Weber, Michel; Péchereau, Alain; Lebranchu, Pierre

    2018-01-01

    Abnormal torsion could be associated with cyclovertical strabismus, but torsion measurements are not reliable in children. To assess an objective fundus torsion evaluation in a paediatric population, we used Non-Mydriatic Fundus photography (NMFP) in healthy and cyclovertical strabismus patients to evaluate the disc-foveal angle over time and observers. We used a retrospective set of NMFP including 24 A or V-pattern strabismus and 27 age-matched normal children (mean age 6.4 and 6.7 years respectively), taken during 2 distinct follow-up consultations (separated by 251 and 479 days respectively). Each disc-foveal angle measurement (from which the ocular torsion can be assessed) was performed by 5 different observers, using graphical software and based on reproducible fundus anatomical marks. Statistical analysis was performed with a multivariate ANOVA using group, time and observers as factors, in addition to intraclass coefficient correlation (ICC) to assess measurement reproducibility. A significant difference of disc-foveal angle measures was observed between groups (p0,97). Abnormal amount of objective torsion could be associated with alphabet-pattern strabismus. Disc-foveal angle evaluation by NMFP in a children population appears as a non-invasive, reliable and reproducible method.

  14. Reproducibility and Reliability of the Quality of Life Questionnaire in Patients With Atrial Fibrillation

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    Rita Simone Lopes Moreira

    2016-03-01

    Full Text Available Abstract Background: Studies have shown the impact of atrial fibrillation (AF on the patients' quality of life. Specific questionnaires enable the evaluation of relevant events. We previously developed a questionnaire to assess the quality of life of patients with AF (AFQLQ version 1, which was reviewed in this study, and new domains were added. Objective: To demonstrate the reproducibility of the AFQLQ version 2 (AFQLQ v.2, which included the domains of fatigue, illness perception and well-being. Methods: We applied 160 questionnaires (AFQLQ v.2 and SF-36 to 40 patients, at baseline and 15 days after, to measure inter- and intraobserver reproducibility. The analysis of quality of life stability was determined by test-retest, applying the Bartko intraclass correlation coefficient (ICC. Internal consistency was assessed by Cronbach's alpha test. Results: The total score of the test-retest (n = 40 had an ICC of 0.98 in the AFQLQ v.2, and of 0.94 in the SF36. In assessing the intra- and interobserver reproducibility of the AFQLQ v.2, the ICC reliability was 0.98 and 0.97, respectively. The internal consistency had a Cronbach's alpha coefficient of 0.82, compatible with good agreement of the AFQLQ v.2. Conclusion: The AFQLQ v.2 performed better than its previous version. Similarly, the domains added contributed to make it more comprehensive and robust to assess the quality of life of patients with AF.

  15. Reliability and reproducibility of subaxial cervical injury description system: a standardized nomenclature schema.

    Science.gov (United States)

    Bono, Christopher M; Schoenfeld, Andrew; Gupta, Giri; Harrop, James S; Anderson, Paul; Patel, Alpesh A; Dimar, John; Aarabi, Bizhan; Dailey, Andrew; Vaccaro, Alexander R; Gahr, Ralf; Shaffrey, Christopher; Anderson, David G; Rampersaud, Raj

    2011-08-01

    Radiographic measurement study. To develop a standardized cervical injury nomenclature system to facilitate description, communication, and classification among health care providers. The reliability and reproducibility of this system was then examined. Description of subaxial cervical injuries is critical for treatment decision making and comparing scientific reports of outcomes. Despite a number of available classification systems, surgeons, and researchers continue to use descriptive nomenclature, such as "burst" and "teardrop" fractures, to describe injuries. However, there is considerable inconsistency with use of such terms in the literature. Eleven distinct injury types and associated definitions were established for the subaxial cervical spine and subsequently refined by members of the Spine Trauma Study Group. A series of 18 cases of patients with a broad spectrum of subaxial cervical spine injuries was prepared and distributed to surgeon raters. Each rater was provided with the full nomenclature document and asked to select primary and secondary injury types for each case. After receipt of the raters' first round of classifications, the cases were resorted and returned to the raters for a second round of review. Interrater and intrarater reliabilities were calculated as percent agreement and Cohen kappa (κ) values. Intrarater reliability was assessed by comparing a given rater's diagnosis from the first and second rounds. Nineteen surgeons completed the first and second rounds of the study. Overall, the system demonstrated 56.4% interrater agreement and 72.8% intrarater agreement. Overall, interrater κ values demonstrated moderate agreement while intrarater κ values showed substantial agreement. Analyzed by injury types, only four (burst fractures, lateral mass fractures, flexion teardrop fractures, and anterior distraction injuries) demonstrated greater than 50% interrater agreement. This study demonstrated that, even in ideal circumstances, there is

  16. Reproducibility and reliability of hypoglycaemic episodes recorded with Continuous Glucose Monitoring System (CGMS) in daily life

    DEFF Research Database (Denmark)

    Høi-Hansen, T; Pedersen-Bjergaard, U; Thorsteinsson, B

    2005-01-01

    AIM: Continuous glucose monitoring may reveal episodes of unrecognized hypoglycaemia. We evaluated reproducibility and reliability of hypoglycaemic episodes recorded in daily life by the Medtronic MiniMed Continuous Glucose Monitoring System (CGMS). METHODS: Twenty-nine adult patients with Type 1...... data were recalibrated generating four different CGMS data sets [left-A (left side of abdomen, calibration set A), left-B, right-A and right-B]. Agreement between CGMS data sets was evaluated during hypoglycaemic events, comparing CGMS readings = 2.2 mmol/l with nadir values from corresponding CGMS...... data sets. CGMS readings were also compared with independent self-monitored blood glucose (SMBG) values. RESULTS: With hypoglycaemia (CGMS readings = 2.2 mmol/l) in calibration set left-A, values below 3.5 mmol/l were present in 99% (95% CI: 95-100%) of samples in left-B, 91% (95% CI: 84...

  17. Highly reliable field electron emitters produced from reproducible damage-free carbon nanotube composite pastes with optimal inorganic fillers

    Science.gov (United States)

    Kim, Jae-Woo; Jeong, Jin-Woo; Kang, Jun-Tae; Choi, Sungyoul; Ahn, Seungjoon; Song, Yoon-Ho

    2014-02-01

    Highly reliable field electron emitters were developed using a formulation for reproducible damage-free carbon nanotube (CNT) composite pastes with optimal inorganic fillers and a ball-milling method. We carefully controlled the ball-milling sequence and time to avoid any damage to the CNTs, which incorporated fillers that were fully dispersed as paste constituents. The field electron emitters fabricated by printing the CNT pastes were found to exhibit almost perfect adhesion of the CNT emitters to the cathode, along with good uniformity and reproducibility. A high field enhancement factor of around 10 000 was achieved from the CNT field emitters developed. By selecting nano-sized metal alloys and oxides and using the same formulation sequence, we also developed reliable field emitters that could survive high-temperature post processing. These field emitters had high durability to post vacuum annealing at 950 °C, guaranteeing survival of the brazing process used in the sealing of field emission x-ray tubes. We evaluated the field emitters in a triode configuration in the harsh environment of a tiny vacuum-sealed vessel and observed very reliable operation for 30 h at a high current density of 350 mA cm-2. The CNT pastes and related field emitters that were developed could be usefully applied in reliable field emission devices.

  18. Highly reproducible and reliable metal/graphene contact by ultraviolet-ozone treatment

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei [Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871 (China); Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Hacker, Christina A.; Cheng, Guangjun; Hight Walker, A. R.; Richter, Curt A.; Gundlach, David J., E-mail: david.gundlach@nist.gov, E-mail: liangxl@pku.edu.cn [Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Liang, Yiran; Tian, Boyuan; Liang, Xuelei, E-mail: david.gundlach@nist.gov, E-mail: liangxl@pku.edu.cn; Peng, Lianmao [Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871 (China)

    2014-03-21

    Resist residue from the device fabrication process is a significant source of contamination at the metal/graphene contact interface. Ultraviolet Ozone (UVO) treatment is proven here, by X-ray photoelectron spectroscopy and Raman measurement, to be an effective way of cleaning the metal/graphene interface. Electrical measurements of devices that were fabricated by using UVO treatment of the metal/graphene contact region show that stable and reproducible low resistance metal/graphene contacts are obtained and the electrical properties of the graphene channel remain unaffected.

  19. Highly reproducible and reliable metal/graphene contact by ultraviolet-ozone treatment

    International Nuclear Information System (INIS)

    Li, Wei; Hacker, Christina A.; Cheng, Guangjun; Hight Walker, A. R.; Richter, Curt A.; Gundlach, David J.; Liang, Yiran; Tian, Boyuan; Liang, Xuelei; Peng, Lianmao

    2014-01-01

    Resist residue from the device fabrication process is a significant source of contamination at the metal/graphene contact interface. Ultraviolet Ozone (UVO) treatment is proven here, by X-ray photoelectron spectroscopy and Raman measurement, to be an effective way of cleaning the metal/graphene interface. Electrical measurements of devices that were fabricated by using UVO treatment of the metal/graphene contact region show that stable and reproducible low resistance metal/graphene contacts are obtained and the electrical properties of the graphene channel remain unaffected

  20. Reliability and reproducibility analysis of the Cobb angle and assessing sagittal plane by computer-assisted and manual measurement tools.

    Science.gov (United States)

    Wu, Weifei; Liang, Jie; Du, Yuanli; Tan, Xiaoyi; Xiang, Xuanping; Wang, Wanhong; Ru, Neng; Le, Jinbo

    2014-02-06

    Although many studies on reliability and reproducibility of measurement have been performed on coronal Cobb angle, few results about reliability and reproducibility are reported on sagittal alignment measurement including the pelvis. We usually use SurgimapSpine software to measure the Cobb angle in our studies; however, there are no reports till date on its reliability and reproducible measurements. Sixty-eight standard standing posteroanterior whole-spine radiographs were reviewed. Three examiners carried out the measurements independently under the settings of manual measurement on X-ray radiographies and SurgimapSpine software on the computer. Parameters measured included pelvic incidence, sacral slope, pelvic tilt, Lumbar lordosis (LL), thoracic kyphosis, and coronal Cobb angle. SPSS 16.0 software was used for statistical analyses. The means, standard deviations, intraclass and interclass correlation coefficient (ICC), and 95% confidence intervals (CI) were calculated. There was no notable difference between the two tools (P = 0.21) for the coronal Cobb angle. In the sagittal plane parameters, the ICC of intraobserver reliability for the manual measures varied from 0.65 (T2-T5 angle) to 0.95 (LL angle). Further, for SurgimapSpine tool, the ICC ranged from 0.75 to 0.98. No significant difference in intraobserver reliability was found between the two measurements (P > 0.05). As for the interobserver reliability, measurements with SurgimapSpine tool had better ICC (0.71 to 0.98 vs 0.59 to 0.96) and Pearson's coefficient (0.76 to 0.99 vs 0.60 to 0.97). The reliability of SurgimapSpine measures was significantly higher in all parameters except for the coronal Cobb angle where the difference was not significant (P > 0.05). Although the differences between the two methods are very small, the results of this study indicate that the SurgimapSpine measurement is an equivalent measuring tool to the traditional manual in coronal Cobb angle, but is advantageous in spino

  1. Reliability and reproducibility of disc-foveal angle measurements by non-mydriatic fundus photography

    OpenAIRE

    Le Jeune, Caroline; Chebli, Fayçal; Leon, Lorette; Anthoine, Emmanuelle; Weber, Michel; Péchereau, Alain; Lebranchu, Pierre

    2018-01-01

    Purpose Abnormal torsion could be associated with cyclovertical strabismus, but torsion measurements are not reliable in children. To assess an objective fundus torsion evaluation in a paediatric population, we used Non-Mydriatic Fundus photography (NMFP) in healthy and cyclovertical strabismus patients to evaluate the disc-foveal angle over time and observers. Methods We used a retrospective set of NMFP including 24 A or V-pattern strabismus and 27 age-matched normal children (mean age 6.4 a...

  2. Resuming the discussion of AMSTAR: What can (should be made better?

    Directory of Open Access Journals (Sweden)

    Uta Wegewitz

    2016-08-01

    Full Text Available Abstract Background Evidence syntheses, and in particular systematic reviews (SRs, have become one of the cornerstones of evidence-based health care. The Assessment of Multiple Systematic Reviews (AMSTAR tool has become the most widely used tool for investigating the methodological quality of SRs and is currently undergoing revision. The objective of this paper is to present insights, challenges and potential solutions from the point of view of a group of assessors, while referring to earlier methodological discussions and debates with respect to AMSTAR. Discussion One major drawback of AMSTAR is that it relies heavily on reporting quality rather than on methodological quality. This can be found in several items. Furthermore, it should be acknowledged that there are now new methods and procedures that did not exist when AMSTAR was developed. For example, the note to item 1 should now refer to the International Prospective Register of Ongoing Systematic Reviews (PROSPERO. Furthermore, item 3 should consider the definition of hand-searching, as the process of reviewing conference proceedings using the search function (e.g. in Microsoft Word or in a PDF file does not meet the definition set out by the Cochrane Collaboration. Moreover, methods for assessing the quality of the body of evidence have evolved since AMSTAR was developed and should be incorporated into a revised AMSTAR tool. Summary Potential solutions are presented for each AMSTAR item with the aim of allowing a more thorough assessment of SRs. As the AMSTAR tool is currently undergoing further development, our paper hopes to add to preceding discussions and papers regarding this tool and stimulate further discussion.

  3. Reliable Mechanochemistry: Protocols for Reproducible Outcomes of Neat and Liquid Assisted Ball-mill Grinding Experiments.

    Science.gov (United States)

    Belenguer, Ana M; Lampronti, Giulio I; Sanders, Jeremy K M

    2018-01-23

    The equilibrium outcomes of ball mill grinding can dramatically change as a function of even tiny variations in the experimental conditions such as the presence of very small amounts of added solvent. To reproducibly and accurately capture this sensitivity, the experimentalist needs to carefully consider every single factor that can affect the ball mill grinding reaction under investigation, from ensuring the grinding jars are clean and dry before use, to accurately adding the stoichiometry of the starting materials, to validating that the delivery of solvent volume is accurate, to ensuring that the interaction between the solvent and the powder is well understood and, if necessary, a specific soaking time is added to the procedure. Preliminary kinetic studies are essential to determine the necessary milling time to achieve equilibrium. Only then can exquisite phase composition curves be obtained as a function of the solvent concentration under ball mill liquid assisted grinding (LAG). By using strict and careful procedures analogous to the ones here presented, such milling equilibrium curves can be obtained for virtually all milling systems. The system we use to demonstrate these procedures is a disulfide exchange reaction starting from the equimolar mixture of two homodimers to obtain at equilibrium quantitative heterodimer. The latter is formed by ball mill grinding as two different polymorphs, Form A and Form B. The ratio R = [Form B] / ([Form A] + [Form B]) at milling equilibrium depends on the nature and concentration of the solvent in the milling jar.

  4. Procedures and methods that increase reliability and reproducibility of the transplanted kidney perfusion index

    International Nuclear Information System (INIS)

    Smokvina, A.

    1994-01-01

    At different times following surgery and during various complications, 119 studies were performed on 57 patients. In many patients studies were repeated several times. Twenty-three studies were performed in as many patients, in whom a normal function of the transplanted kidney was established by other diagnostic methods and retrospective analysis. Comparison was made of the perfusion index results obtained by the Hilson et al. method from 1978 and the ones obtained by my own modified method, which for calculating the index also takes into account: the time difference in appearance of the initial portions of the artery and kidney curves; the positioning of the region of interest over the distal part of the aorta; the bolus injection into the arteriovenous shunt of the forearm with high specific activity of small volumes of Tc-99m labelled agents; a fast 0.5 seconds study of data collection; and a standard for normalization of numerical data. The reliability of one or the other method tested by simulated time shift of the peak of arterial curves shows that the deviation percentage from the main index value in the unmodified method is 2-5 times greater than in the modified method. The normal value of the perfusion index applying the modified method is 91-171. (author)

  5. How is AMSTAR applied by authors - a call for better reporting.

    Science.gov (United States)

    Pieper, Dawid; Koensgen, Nadja; Breuing, Jessica; Ge, Long; Wegewitz, Uta

    2018-06-18

    The assessment of multiple systematic reviews (AMSTAR) tool is widely used for investigating the methodological quality of systematic reviews (SR). Originally, AMSTAR was developed for SRs of randomized controlled trials (RCTs). Its applicability to SRs of other study designs remains unclear. Our objectives were to: 1) analyze how AMSTAR is applied by authors and (2) analyze whether the authors pay attention to the original purpose of AMSTAR and for what it has been validated. We searched MEDLINE (via PubMed) from inception through October 2016 to identify studies that applied AMSTAR. Full-text studies were sought for all retrieved hits and screened by one reviewer. A second reviewer verified the excluded studies (liberal acceleration). Data were extracted into structured tables by one reviewer and were checked by a second reviewer. Discrepancies at any stage were resolved by consensus or by consulting a third person. We analyzed the data descriptively as frequencies or medians and interquartile ranges (IQRs). Associations were quantified using the risk ratio (RR), with 95% confidence intervals. We identified 247 studies. They included a median of 17 reviews (interquartile range (IQR): 8 to 47) per study. AMSTAR was modified in 23% (57/247) of studies. In most studies, an AMSTAR score was calculated (200/247; 81%). Methods for calculating an AMSTAR score varied, with summing up all yes answers (yes = 1) being the most frequent option (102/200; 51%). More than one third of the authors failed to report how the AMSTAR score was obtained (71/200; 36%). In a subgroup analysis, we compared overviews of reviews (n = 154) with the methodological publications (n = 93). The overviews of reviews were much less likely to mention both limitations with respect to study designs (if other studies other than RCTs were included in the reviews) (RR 0.27, 95% CI 0.09 to 0.75) and overall score (RR 0.08, 95% CI 0.02 to 0.35). Authors, peer reviewers, and editors should pay

  6. Pore sub-features reproducibility in direct microscopic and Livescan images--their reliability in personal identification.

    Science.gov (United States)

    Gupta, Abhishek; Sutton, Raul

    2010-07-01

    Third level features have been reported to have equal discriminatory power as second level details in establishing personal identification. Pore area, as an extended set third level sub-feature, has been studied by minimizing possible factors that could affect pore size. The reproducibility of pore surface area has been studied using direct microscopic and 500 ppi Livescan images. Direct microscopic pore area measurements indicated that the day on which the pore area was measured had a significant impact on the measured pore area. Pore area measurement was shown to be difficult to estimate in 500 ppi Livescan measurements owing to lack of resolution. It is not possible to reliably use pore area as an identifying feature in fingerprint examination.

  7. 3D-modeling of the spine using EOS imaging system: Inter-reader reproducibility and reliability.

    Directory of Open Access Journals (Sweden)

    Johannes Rehm

    Full Text Available To retrospectively assess the interreader reproducibility and reliability of EOS 3D full spine reconstructions in patients with adolescent idiopathic scoliosis (AIS.73 patients with mean age of 17 years and a moderate AIS (median Cobb Angle 18.2° obtained low-dose standing biplanar radiographs with EOS. Two independent readers performed "full spine" 3D reconstructions of the spine with the "full-spine" method adjusting the bone contour of every thoracic and lumbar vertebra (Th1-L5. Interreader reproducibility was assessed regarding rotation of every single vertebra in the coronal (i.e. frontal, sagittal (i.e. lateral, and axial plane, T1/T12 kyphosis, T4/T12 kyphosis, L1/L5 lordosis, L1/S1 lordosis and pelvic parameters. Radiation exposure, scan-time and 3D reconstruction time were recorded.Interclass correlation (ICC ranged between 0.83 and 0.98 for frontal vertebral rotation, between 0.94 and 0.99 for lateral vertebral rotation and between 0.51 and 0.88 for axial vertebral rotation. ICC was 0.92 for T1/T12 kyphosis, 0.95 for T4/T12 kyphosis, 0.90 for L1/L5 lordosis, 0.85 for L1/S1 lordosis, 0.97 for pelvic incidence, 0.96 for sacral slope, 0.98 for sagittal pelvic tilt and 0.94 for lateral pelvic tilt. The mean time for reconstruction was 14.9 minutes (reader 1: 14.6 minutes, reader 2: 15.2 minutes, p<0.0001. The mean total absorbed dose was 593.4μGy ±212.3 per patient.EOS "full spine" 3D angle measurement of vertebral rotation proved to be reliable and was performed in an acceptable reconstruction time. Interreader reproducibility of axial rotation was limited to some degree in the upper and middle thoracic spine due the obtuse angulation of the pedicles and the processi spinosi in the frontal view somewhat complicating their delineation.

  8. Intra-observer reproducibility and interobserver reliability of the radiographic parameters in the Spinal Deformity Study Group's AIS Radiographic Measurement Manual.

    Science.gov (United States)

    Dang, Natasha Radhika; Moreau, Marc J; Hill, Douglas L; Mahood, James K; Raso, James

    2005-05-01

    Retrospective cross-sectional assessment of the reproducibility and reliability of radiographic parameters. To measure the intra-examiner and interexaminer reproducibility and reliability of salient radiographic features. The management and treatment of adolescent idiopathic scoliosis (AIS) depends on accurate and reproducible radiographic measurements of the deformity. Ten sets of radiographs were randomly selected from a sample of patients with AIS, with initial curves between 20 degrees and 45 degrees. Fourteen measures of the deformity were measured from posteroanterior and lateral radiographs by 2 examiners, and were repeated 5 times at intervals of 3-5 days. Intra-examiner and interexaminer differences were examined. The parameters include measures of curve size, spinal imbalance, sagittal kyphosis and alignment, maximum apical vertebral rotation, T1 tilt, spondylolysis/spondylolisthesis, and skeletal age. Intra-examiner reproducibility was generally excellent for parameters measured from the posteroanterior radiographs but only fair to good for parameters from the lateral radiographs, in which some landmarks were not clearly visible. Of the 13 parameters observed, 7 had excellent interobserver reliability. The measurements from the lateral radiograph were less reproducible and reliable and, thus, may not add value to the assessment of AIS. Taking additional measures encourages a systematic and comprehensive assessment of spinal radiographs.

  9. A flood tide of systematic reviews on endodontic posts: methodological assessment using of R-AMSTAR.

    Science.gov (United States)

    Schmitter, M; Sterzenbach, G; Faggion, C M; Krastl, G

    2013-06-01

    To help the dental practitioner solve a specific clinical problem, systematic reviews (SRs) are seen as the best guide. In addition to the unmanageable quantity of SRs, however, one should be aware of their variable quality. The present review describes the methodological quality of SRs on postendodontic restorations to work out the value of these reviews for the dental practitioner. SRs were searched in April 2012, independently and in triplicate. Post survival was used as measure of outcome. The methodological quality of included SRs was assessed with the Revised Assessment of Multiple Systematic Reviews (R-AMSTAR) checklist. Kappa statistics were used to assess reviewer agreement. Three hundred sixty-three papers were retrieved from the initial search. Ten SRs were included. One SR achieved a high R-AMSTAR score, whereas the other nine SRs achieved scores that indicate a substantial lack of methodological quality. Especially the items "grey literature," "combination of findings," "likelihood of publication bias," and conflict of interest" showed low R-AMSTAR scores. The three reviews with the highest R-AMSTAR scores tended to conclude that fewer failures occurred when using nonmetal posts. The reviewer agreement was excellent (kappa ranged from 0.79 to 0.85) in the R-AMSTAR classification. The approach presented revealed a lack of SRs with high methodological quality. Thus, no decisive conclusion can be drawn with respect to this topic. It appears that there is a trend for the superiority of fiber-reinforced posts. SRs must be of high methodological quality. This can be achieved by taking into consideration the results of this review. Improved methodological quality would make SRs more supportive for the general practitioner.

  10. Validity, reliability, and reproducibility of linear measurements on digital models obtained from intraoral and cone-beam computed tomography scans of alginate impressions

    NARCIS (Netherlands)

    Wiranto, Matthew G.; Engelbrecht, W. Petrie; Nolthenius, Heleen E. Tutein; van der Meer, W. Joerd; Ren, Yijin

    INTRODUCTION: Digital 3-dimensional models are widely used for orthodontic diagnosis. The aim of this study was to assess the validity, reliability, and reproducibility of digital models obtained from the Lava Chairside Oral scanner (3M ESPE, Seefeld, Germany) and cone-beam computed tomography scans

  11. Reliability and Reproducibility of Advanced ECG Parameters in Month-to-Month and Year-to-Year Recordings in Healthy Subjects

    Science.gov (United States)

    Starc, Vito; Abughazaleh, Ahmed S.; Schlegel, Todd T.

    2014-01-01

    Advanced resting ECG parameters such the spatial mean QRS-T angle and the QT variability index (QTVI) have important diagnostic and prognostic utility, but their reliability and reproducibility (R&R) are not well characterized. We hypothesized that the spatial QRS-T angle would have relatively higher R&R than parameters such as QTVI that are more responsive to transient changes in the autonomic nervous system. The R&R of several conventional and advanced ECG para-meters were studied via intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) in: (1) 15 supine healthy subjects from month-to-month; (2) 27 supine healthy subjects from year-to-year; and (3) 25 subjects after transition from the supine to the seated posture. As hypothesized, for the spatial mean QRS-T angle and many conventional ECG parameters, ICCs we-re higher, and CVs lower than QTVI, suggesting that the former parameters are more reliable and reproducible.

  12. The reliability and reproducibility of the Hertel classification for comminuted proximal humeral fractures compared with the Neer classification

    NARCIS (Netherlands)

    Iordens, Gijs I. T.; Mahabier, Kiran C.; Buisman, Florian E.; Schep, Niels W. L.; Muradin, Galied S. R.; Beenen, Ludo F. M.; Patka, Peter; van Lieshout, Esther M. M.; den Hartog, Dennis

    2016-01-01

    The Neer classification is the most commonly used fracture classification system for proximal humeral fractures. Inter- and intra-observer agreement is limited, especially for comminuted fractures. A possibly more straightforward and reliable classification system is the Hertel classification. The

  13. Quality assessment of systematic reviews on total hip or knee arthroplasty using mod-AMSTAR.

    Science.gov (United States)

    Wu, Xinyu; Sun, Huan; Zhou, Xiaoqin; Wang, Ji; Li, Jing

    2018-03-16

    Increasing numbers of systematic reviews (SRs) on total knee arthroplasty (TKA) and total hip arthroplasty (THA) have been published in recent years, but their quality has been unclear. The purpose of this study is to evaluate the methodological quality of SRs on TKA and THA. We searched Ovid-Medline, Ovid-Embase, Cochrane Databases (including HTA, DARE, and CDSR), CBM, CNKI, Wang Fang, and VIP, from January 2014 to December 2015 for THA and TKA. The quality of SRs was assessed using the modified 25-item "Assessment of Multiple Systematic Reviews" (mod-AMSTAR) tool, which was based on the AMSTAR scale. A T-test, nonparametric test, and linear regression were conducted to assess the relationship between bibliographical characteristics and methodological quality. Sixty-three SRs were included, from which the majority of SRs (50, 79.4%) were conducted in Asia. Only 4 reviews were rated as high quality, and most were weak in providing a priori design (6, 9.5%), not limiting the publication type (8, 13%), providing an excluded primary studies list (4, 6.3%) and reporting support for the included primary studies (1, 1.6%). Reviews published in English journals performed better than did Chinese journals in duplicate data extraction (81.3% vs 46.7%, p = 0.017; 70.8% vs 33.3%, p = 0.009) and providing source of support for the SR (87.5% vs 33.3%, P quality of the included SRs is far from satisfactory. Authors of SRs should conform to the recommendations outlined in the mod-AMSTAR items. Areas needing improvement were providing a priori design, not limiting the publication type, providing an excluded primary studies list, and reporting conflicts of interest.

  14. Development of the Japanese version of the Council on Nutrition Appetite Questionnaire and its simplified versions, and evaluation of their reliability, validity, and reproducibility.

    Science.gov (United States)

    Tokudome, Yuko; Okumura, Keiko; Kumagai, Yoshiko; Hirano, Hirohiko; Kim, Hunkyung; Morishita, Shiho; Watanabe, Yutaka

    2017-11-01

    Because few Japanese questionnaires assess the elderly's appetite, there is an urgent need to develop an appetite questionnaire with verified reliability, validity, and reproducibility. We translated and back-translated the Council on Nutrition Appetite Questionnaire (CNAQ), which has eight items, into Japanese (CNAQ-J), as well as the Simplified Nutritional Appetite Questionnaire (SNAQ-J), which includes four CNAQ-J-derived items. Using structural equation modeling, we examined the CNAQ-J structure based on data of 649 Japanese elderly people in 2013, including individuals having a certain degree of cognitive impairment, and we developed the SNAQ for the Japanese elderly (SNAQ-JE) according to an exploratory factor analysis. Confirmatory factor analyses on the appetite questionnaires were conducted to probe fitting to the model. We computed Cronbach's α coefficients and criterion-referenced/-related validity figures examining associations of the three appetite battery scores with body mass index (BMI) values and with nutrition-related questionnaire values. Test-retest reproducibility of appetite tools was scrutinized over an approximately 2-week interval. An exploratory factor analysis demonstrated that the CNAQ-J was constructed of one factor (appetite), yielding the SNAQ-JE, which includes four questions derived from the CNAQ-J. The three appetite instruments showed almost equivalent fitting to the model and reproducibility. The CNAQ-J and SNAQ-JE demonstrated satisfactory reliability and significant criterion-referenced/-related validity values, including BMIs, but the SNAQ-J included a low factor-loading item, exhibited less satisfactory reliability and had a non-significant relationship to BMI. The CNAQ-J and SNAQ-JE may be applied to assess the appetite of Japanese elderly, including persons with some cognitive impairment. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  15. Reproducibility and intermethod reliability of a calcium food frequency questionnaire for use in Hispanic, non-Hispanic Black, and non-Hispanic White youth.

    Science.gov (United States)

    Ollberding, Nicholas J; Gilsanz, Vicente; Lappe, Joan M; Oberfield, Sharon E; Shepherd, John A; Winer, Karen K; Zemel, Babette S; Kalkwarf, Heidi J

    2015-04-01

    A dietary assessment instrument designed for use in a nationally representative pediatric population was required to examine associations between calcium intake and bone mineral accrual in a large, multicenter study. To determine the reproducibility and intermethod reliability of a youth calcium food frequency questionnaire (FFQ) in a multiracial/ethnic sample of children and adolescents. Reproducibility (n=69) and intermethod reliability (n=393) studies were conducted by administering repeat FFQs and three unannounced 24-hour dietary recalls to stratified random samples of individuals participating in the Bone Mineral Density in Childhood Study. Children and adolescents ages 5 to 21 years. Calcium intake estimated from the FFQ and 24-hour dietary recalls. Reproducibility was assessed by the intraclass correlation coefficient (ICC). Intermethod reliability was assessed by deattenuated Pearson correlations between the FFQ and 24-hour recalls. Attenuation factors and calibration corrected effect estimates for bone density were calculated to determine the potential influence of measurement error on associations with health outcomes. The ICC (0.61) for repeat administrations and deattenuated Pearson correlation between the FFQ and 24-hour recalls (r=0.60) for all subjects indicated reproducibility and intermethod reliability (Pearson r=0.50 to 0.74 across sex and age groups). Attenuation factors were ≤0.50 for all sex and age groups and lower for non-Hispanic blacks (λ=0.20) and Hispanics (λ=0.26) than for non-Hispanic whites (λ=0.42). The Bone Mineral Density in Childhood Study calcium FFQ appears to provide a useful tool for assessing calcium intake in children and adolescents drawn from multiracial/ethnic populations and/or spanning a wide age range. However, similar to other FFQs, attenuation factors were substantially <1, indicating the potential for appreciable measurement error bias. Calibration correction should be performed and racial/ethnic differences

  16. Reliability and reproducibility of several methods of arthroscopic assessment of femoral tunnel position during anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Ilahi, Omer A; Mansfield, David J; Urrea, Luis H; Qadeer, Ali A

    2014-10-01

    To assess interobserver and intraobserver agreement of estimating anterior cruciate ligament (ACL) femoral tunnel positioning arthroscopically using circular and linear (noncircular) estimation methods and to determine whether overlay template visual aids improve agreement. Standardized intraoperative pictures of femoral tunnel pilot holes (taken with a 30° arthroscope through an anterolateral portal at 90° of knee flexion with horizontal being parallel to the tibial surface) in 27 patients undergoing single-bundle ACL reconstruction were presented to 3 fellowship-trained arthroscopists on 2 separate occasions. On both viewings, each surgeon estimated the femoral tunnel pilot hole location to the nearest half-hour mark using a whole clock face and half clock face, to the nearest 15° using a whole compass and half compass, in the top or bottom half of a linear quadrant, and in the top or bottom half of a linear trisector. Evaluations were performed first without and then with an overlay template of each estimation method. The average difference among reviewers was quite similar for all 4 circular methods with the use of visual aids. Without overlay template visual aids, pair-wise κ statistic values for interobserver agreement ranged from -0.14 to 0.56 for the whole clock face and from 0.16 to 0.42 for the half clock face. With overlay visual guides, interobserver agreement ranged from 0.29 to 0.63 for the whole clock face and from 0.17 to 0.66 for the half clock face. The quadrant method's interobserver agreement ranged from 0.22 to 0.60, and that of the trisection method ranged from 0.17 to 0.57. Neither linear estimation method's reliability uniformly improved with the use of overlay templates. Intraobserver agreement without overlay templates ranged from 0.17 to 0.49 for the whole clock face, 0.11 to 0.47 for the half clock face, 0.01 to 0.66 for the quadrant method, and 0.20 to 0.57 for the trisection method. Use of overlay templates did not uniformly

  17. A reliable and reproducible technique for DNA fingerprinting in biorepositories: a pilot study from BioBIM.

    Science.gov (United States)

    Palmirotta, Raffaele; De Marchis, Maria Laura; Ludovici, Giorgia; Ialongo, Cristiano; Leone, Barbara; Lopez, Nadia; Valente, Maria Giovanna; Spila, Antonella; Ferroni, Patrizia; Della-Morte, David; Guadagni, Fiorella

    2013-12-17

    Standard operating procedures (SOPs) optimization for nucleic acid extraction from stored samples is of crucial importance in a biological repository, considering the large number of collected samples and their future downstream molecular and biological applications. However, the validity of molecular studies using stored specimens depends not only on the integrity of the biological samples, but also on the procedures that ensure the traceability of the same sample, certifying its uniqueness, and ensuring the identification of potential sample contaminations. With this aim, we have developed a rapid, reliable, low-cost, and simple DNA fingerprinting tool for a routine use in quality control of biorepositories samples. The method consists of a double ALU insertion/deletion genotyping panel suitable for uniqueness, identification of sample contaminations, and gender validation. Preliminary data suggest that this easy-to-use DNA fingerprinting protocol could routinely provide assurances of DNA identity and quality in a biorepository setting.

  18. Can we improve accuracy and reliability of MRI interpretation in children with optic pathway glioma? Proposal for a reproducible imaging classification

    Energy Technology Data Exchange (ETDEWEB)

    Lambron, Julien; Frampas, Eric; Toulgoat, Frederique [University Hospital, Department of Radiology, Nantes (France); Rakotonjanahary, Josue [University Hospital, Department of Pediatric Oncology, Angers (France); University Paris Diderot, INSERM CIE5 Robert Debre Hospital, Assistance Publique-Hopitaux de Paris (AP-HP), Paris (France); Loisel, Didier [University Hospital, Department of Radiology, Angers (France); Carli, Emilie de; Rialland, Xavier [University Hospital, Department of Pediatric Oncology, Angers (France); Delion, Matthieu [University Hospital, Department of Neurosurgery, Angers (France)

    2016-02-15

    Magnetic resonance (MR) images from children with optic pathway glioma (OPG) are complex. We initiated this study to evaluate the accuracy of MR imaging (MRI) interpretation and to propose a simple and reproducible imaging classification for MRI. We randomly selected 140 MRIs from among 510 MRIs performed on 104 children diagnosed with OPG in France from 1990 to 2004. These images were reviewed independently by three radiologists (F.T., 15 years of experience in neuroradiology; D.L., 25 years of experience in pediatric radiology; and J.L., 3 years of experience in radiology) using a classification derived from the Dodge and modified Dodge classifications. Intra- and interobserver reliabilities were assessed using the Bland-Altman method and the kappa coefficient. These reviews allowed the definition of reliable criteria for MRI interpretation. The reviews showed intraobserver variability and large discrepancies among the three radiologists (kappa coefficient varying from 0.11 to 1). These variabilities were too large for the interpretation to be considered reproducible over time or among observers. A consensual analysis, taking into account all observed variabilities, allowed the development of a definitive interpretation protocol. Using this revised protocol, we observed consistent intra- and interobserver results (kappa coefficient varying from 0.56 to 1). The mean interobserver difference for the solid portion of the tumor with contrast enhancement was 0.8 cm{sup 3} (limits of agreement = -16 to 17). We propose simple and precise rules for improving the accuracy and reliability of MRI interpretation for children with OPG. Further studies will be necessary to investigate the possible prognostic value of this approach. (orig.)

  19. Reliable and reproducible method for rapid identification of Nocardia species by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Toyokawa, Masahiro; Kimura, Keigo; Nishi, Isao; Sunada, Atsuko; Ueda, Akiko; Sakata, Tomomi; Asari, Seishi

    2013-01-01

    Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been challenged for the identification of Nocardia species. However, the standard ethanol-formic acid extraction alone is insufficient in allowing the membrane proteins of Nocardia species to be ionized by the matrix. We therefore aimed to establish our new extraction method for the MALDI-TOF MS-based identification of Nocardia species isolates. Our modified extraction procedure is through dissociation in 0.5% Tween-20 followed by bacterial heat-inactivation, mechanical breaking of the cell wall by acid-washed glass beads and protein extraction with formic acid and acetonitrile. As reference methods for species identification, full-length 16S rRNA gene sequencing and some phenotypical tests were used. In a first step, we made our own Nocardia database by analyzing 13 strains (13 different species including N. elegans, N. otitidiscaviarum, N. asiatica, N. abscessus, N. brasiliensis, N. thailandica, N. farcinica, N. nova, N. mikamii, N. cyriacigeorgica, N. asteroids, Nocardiopsis alba, and Micromonospora sp.) and registered to the MALDI BioTyper database. Then we established our database. The analysis of 12 challenge strains using the our database gave a 100% correct identification, including 8 strains identified to the species level and 4 strains to the genus level (N. elegans, N. nova, N. farcinica, Micromonospora sp.) according to the manufacture's log score specifications. In the estimation of reproducibility of our method intended for 4 strains, both within-run and between-run reproducibility were excellent. These data indicates that our method for rapid identification of Nocardia species is with reliability, reproducibility and cost effective.

  20. A Reliable and Reproducible Model for Assessing the Effect of Different Concentrations of α-Solanine on Rat Bone Marrow Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Adriana Ordóñez-Vásquez

    2017-01-01

    Full Text Available Αlpha-solanine (α-solanine is a glycoalkaloid present in potato (Solanum tuberosum. It has been of particular interest because of its toxicity and potential teratogenic effects that include abnormalities of the central nervous system, such as exencephaly, encephalocele, and anophthalmia. Various types of cell culture have been used as experimental models to determine the effect of α-solanine on cell physiology. The morphological changes in the mesenchymal stem cell upon exposure to α-solanine have not been established. This study aimed to describe a reliable and reproducible model for assessing the structural changes induced by exposure of mouse bone marrow mesenchymal stem cells (MSCs to different concentrations of α-solanine for 24 h. The results demonstrate that nonlethal concentrations of α-solanine (2–6 μM changed the morphology of the cells, including an increase in the number of nucleoli, suggesting elevated protein synthesis, and the formation of spicules. In addition, treatment with α-solanine reduced the number of adherent cells and the formation of colonies in culture. Immunophenotypic characterization and staining of MSCs are proposed as a reproducible method that allows description of cells exposed to the glycoalkaloid, α-solanine.

  1. The 6-min mastication test: a unique test to assess endurance of continuous chewing, normal values, reliability, reproducibility and usability in patients with mitochondrial disease.

    Science.gov (United States)

    van den Engel-Hoek, L; Knuijt, S; van Gerven, M H J C; Lagarde, M L J; Groothuis, J T; de Groot, I J M; Janssen, M C H

    2017-03-01

    In patients with mitochondrial disease, fatigue and muscle problems are the most common complaints. They also experience these complaints during mastication. To measure endurance of continuous mastication in patients with mitochondrial diseases, the 6-min mastication test (6MMT) was developed. This study included the collection of normal data for the 6MMT in a healthy population (children and adults). During 6 min of continuous mastication on a chew tube chewing cycles per minute, total amount of chewing cycles and the difference between minute 1 (M 1 ) and minute 6 (M 2 ) were collected in 271 healthy participants (5-80 years old). These results were compared with those of nine paediatric and 25 adult patients with a mitochondrial disease. Visual analogue scale (VAS) scores were collected directly after the test and after 5 min. A qualitative rating was made on masticatory movements. The reproducibility of the 6MMT in the healthy population with an interval of approximately 2 weeks was good. The inter-rater reliability for the observations was excellent. The patient group demonstrated lower total amount of chewing cycles or had greater differences between M 1 and M 6 . The 6MMT is a reliable and objective test to assess endurance of continuous chewing. It demonstrates the ability of healthy children and adults to chew during 6 min with a highly stable frequency of mastication movements. The test may give an explanation for the masticatory problems in patient groups, who are complaining of pain and fatigue during mastication. © 2017 John Wiley & Sons Ltd.

  2. Reliability

    OpenAIRE

    Condon, David; Revelle, William

    2017-01-01

    Separating the signal in a test from the irrelevant noise is a challenge for all measurement. Low test reliability limits test validity, attenuates important relationships, and can lead to regression artifacts. Multiple approaches to the assessment and improvement of reliability are discussed. The advantages and disadvantages of several different approaches to reliability are considered. Practical advice on how to assess reliability using open source software is provided.

  3. Reproducibility of tender point examination in chronic low back pain patients as measured by intrarater and inter-rater reliability and agreement

    DEFF Research Database (Denmark)

    Jensen, Ole Kudsk; Callesen, Jacob; Nielsen, Merete Graakjaer

    2013-01-01

    back examination and return-to-work intervention, 43 and 39 patients, respectively (18 women, 46%) entered and completed the study. MAIN OUTCOME MEASURES: The reliability was estimated by the intraclass correlation coefficient (ICC), and agreement was calculated for up to ±3 TPs. Furthermore......, the smallest detectable difference was calculated. RESULTS: TP examination was performed twice by two consultants in rheumatology and rehabilitation at 20 min intervals and repeated 1 week later. Intrarater reliability in the more and less experienced rater was ICC 0.84 (95% CI 0.69 to 0.98) and 0.72 (95% CI 0.......49 to 0.95), respectively. The figures for inter-rater reliability were intermediate between these figures. In more than 70% of the cases, the raters agreed within ±3 TPs in both men and women and between test days. The smallest detectable difference between raters was 5, and for the more and less...

  4. Reproducibility and interoperator reliability of obtaining images and measurements of the cervix and uterus with brachytherapy treatment applicators in situ using transabdominal ultrasound.

    Science.gov (United States)

    van Dyk, Sylvia; Garth, Margaret; Oates, Amanda; Kondalsamy-Chennakesavan, Srinivas; Schneider, Michal; Bernshaw, David; Narayan, Kailash

    2016-01-01

    To validate interoperator reliability of brachytherapy radiation therapists (RTs) in obtaining an ultrasound image and measuring the cervix and uterine dimensions using transabdominal ultrasound. Patients who underwent MRI with applicators in situ after the first insertion were included in the study. Imaging was performed by three RTs (RT1, RT2, and RT3) with varying degrees of ultrasound experience. All RTs were required to obtain a longitudinal planning image depicting the applicator in the uterine canal and measure the cervix and uterus. The MRI scan, taken 1 hour after the ultrasound, was used as the reference standard against which all measurements were compared. Measurements were analyzed with intraclass correlation coefficient and Bland-Altman plots. All RTs were able to obtain a suitable longitudinal image for each patient in the study. Mean differences (SD) between MRI and ultrasound measurements obtained by RTs ranged from 3.5 (3.6) to 4.4 (4.23) mm and 0 (3.0) to 0.9 (2.5) mm on the anterior and posterior surface of the cervix, respectively. Intraclass correlation coefficient for absolute agreement between MRI and RTs was >0.9 for all posterior measurement points in the cervix and ranged from 0.41 to 0.92 on the anterior surface. Measurements were not statistically different between RTs at any measurement point. RTs with variable training attained high levels of interoperator reliability when using transabdominal ultrasound to obtain images and measurements of the uterus and cervix with brachytherapy applicators in situ. Access to training and use of a well-defined protocol assist in achieving these high levels of reliability. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  5. Intra- and interobserver reliability and intra-catheter reproducibility using frequency domain optical coherence tomography for the evaluation of morphometric stent parameters and qualitative assessment of stent strut coverage

    International Nuclear Information System (INIS)

    Antonsen, Lisbeth; Thayssen, Per; Junker, Anders; Veien, Karsten Tange; Hansen, Henrik Steen; Hansen, Knud Nørregaard; Hougaard, Mikkel; Jensen, Lisette Okkels

    2015-01-01

    Purpose: Frequency-domain optical coherence tomography (FD-OCT) is a high-resolution imaging tool (~ 10–15 μm), which enables near-histological in-vivo images of the coronary vessel wall. The use of the technique is increasing, both for research- and clinical purposes. This study sought to investigate the intra- and interobserver reliability, as well as the intra-catheter reproducibility of quantitative FD-OCT-assessment of morphometric stent parameters and qualitative FD-OCT-evaluation of strut coverage in 10 randomly selected 6-month follow-up Nobori® biolimus-eluting stents (N-BESs). Methods: Ten N-BESs (213 cross sectional areas (CSAs) and 1897 struts) imaged with OCT 6 months post-implantation were randomly selected and analyzed by 2 experienced analysts, and the same 10 N-BESs were analyzed by one of the analysts 3 months later. Further, 2 consecutive pullbacks randomly performed in another 10 N-BESs (219 CSAs and 1860 struts) were independently assessed by one of the analysts. Results: The intraobserver variability with regard to relative difference of mean luminal area and mean stent area at the CSA-level was very low: 0.1% ± 1.4% and 0.5% ± 3.2%. Interobserver variability also proved to be low: − 2.1% ± 3.3% and 2.1% ± 4.6%, and moreover, very restricted intra-catheter variation was observed: 0.02% ± 6.8% and − 0.18% ± 5.2%. The intraobserver-, interobserver- and intra-catheter reliability for the qualitative evaluation of strut coverage was found to be: kappa (κ) = 0.91 (95% confidence interval (CI): 0.88–0.93, p < 0.01), κ = 0.88 (95% CI: 0.85–0.91, p < 0.01), and κ = 0.73 (95% CI: 0.68–0.78, p < 0.01), respectively. Conclusions: FD-OCT is a reproducible and reliable imaging tool for quantitative evaluation of stented coronary segments, and for qualitative assessment of strut coverage. - Highlights: • Frequency-domain optical coherence tomography (FD-OCT) is increasingly adopted in the catherization laboratories. • This

  6. Intra- and interobserver reliability and intra-catheter reproducibility using frequency domain optical coherence tomography for the evaluation of morphometric stent parameters and qualitative assessment of stent strut coverage

    Energy Technology Data Exchange (ETDEWEB)

    Antonsen, Lisbeth, E-mail: Lisbeth.antonsen@rsyd.dk; Thayssen, Per; Junker, Anders; Veien, Karsten Tange; Hansen, Henrik Steen; Hansen, Knud Nørregaard; Hougaard, Mikkel; Jensen, Lisette Okkels

    2015-12-15

    Purpose: Frequency-domain optical coherence tomography (FD-OCT) is a high-resolution imaging tool (~ 10–15 μm), which enables near-histological in-vivo images of the coronary vessel wall. The use of the technique is increasing, both for research- and clinical purposes. This study sought to investigate the intra- and interobserver reliability, as well as the intra-catheter reproducibility of quantitative FD-OCT-assessment of morphometric stent parameters and qualitative FD-OCT-evaluation of strut coverage in 10 randomly selected 6-month follow-up Nobori® biolimus-eluting stents (N-BESs). Methods: Ten N-BESs (213 cross sectional areas (CSAs) and 1897 struts) imaged with OCT 6 months post-implantation were randomly selected and analyzed by 2 experienced analysts, and the same 10 N-BESs were analyzed by one of the analysts 3 months later. Further, 2 consecutive pullbacks randomly performed in another 10 N-BESs (219 CSAs and 1860 struts) were independently assessed by one of the analysts. Results: The intraobserver variability with regard to relative difference of mean luminal area and mean stent area at the CSA-level was very low: 0.1% ± 1.4% and 0.5% ± 3.2%. Interobserver variability also proved to be low: − 2.1% ± 3.3% and 2.1% ± 4.6%, and moreover, very restricted intra-catheter variation was observed: 0.02% ± 6.8% and − 0.18% ± 5.2%. The intraobserver-, interobserver- and intra-catheter reliability for the qualitative evaluation of strut coverage was found to be: kappa (κ) = 0.91 (95% confidence interval (CI): 0.88–0.93, p < 0.01), κ = 0.88 (95% CI: 0.85–0.91, p < 0.01), and κ = 0.73 (95% CI: 0.68–0.78, p < 0.01), respectively. Conclusions: FD-OCT is a reproducible and reliable imaging tool for quantitative evaluation of stented coronary segments, and for qualitative assessment of strut coverage. - Highlights: • Frequency-domain optical coherence tomography (FD-OCT) is increasingly adopted in the catherization laboratories. • This

  7. Intra- and interobserver reliability and intra-catheter reproducibility using frequency domain optical coherence tomography for the evaluation of morphometric stent parameters and qualitative assessment of stent strut coverage

    DEFF Research Database (Denmark)

    Antonsen, Lisbeth; Thayssen, Per; Junker, Anders

    2015-01-01

    to investigate the intra- and interobserver reliability, as well as the intra-catheter reproducibility of quantitative FD-OCT-assessment of morphometric stent parameters and qualitative FD-OCT-evaluation of strut coverage in 10 randomly selected 6-month follow-up Nobori® biolimus-eluting stents (N-BESs). METHODS...... in another 10 N-BESs (219 CSAs and 1860 struts) were independently assessed by one of the analysts. RESULTS: The intraobserver variability with regard to relative difference of mean luminal area and mean stent area at the CSA-level was very low: 0.1%±1.4% and 0.5%±3.2%. Interobserver variability also proved...... (CI): 0.88-0.93, pstented coronary segments, and for qualitative assessment of strut coverage....

  8. reliability reliability

    African Journals Online (AJOL)

    eobe

    Corresponding author, Tel: +234-703. RELIABILITY .... V , , given by the code of practice. However, checks must .... an optimization procedure over the failure domain F corresponding .... of Concrete Members based on Utility Theory,. Technical ...

  9. The Need for Reproducibility

    Energy Technology Data Exchange (ETDEWEB)

    Robey, Robert W. [Los Alamos National Laboratory

    2016-06-27

    The purpose of this presentation is to consider issues of reproducibility, specifically it determines whether bitwise reproducible computation is possible, if computational research in DOE improves its publication process, and if reproducible results can be achieved apart from the peer review process?

  10. Reliability and reproducibility of spectral and time domain optical coherence tomography images before and after correction for patients with age-related macular degeneration [v2; ref status: indexed, http://f1000r.es/50m

    Directory of Open Access Journals (Sweden)

    Mohammad A. Sadiq

    2015-03-01

    Full Text Available Purpose: To evaluate the reproducibility and reliability of optical coherence tomography scans obtained using the time domain (TD-OCT StratusTM OCT, and the Spectral Domain (SD-OCT SpectralisTM and CirrusTM OCT devices before and after manual correction in eyes with either Neovascular (NV-AMD or Non-Neovascular (NNV-AMD age-related macular degeneration. Design: Prospective observational study. Methods: Setting: University-based retina practice. Patients: Thirty-six patients (50 eyes with NV-AMD or NNV-AMD. Procedure: OCT scans were taken simultaneously using one TD-OCT and two SD-OCT devices. Main Outcome Measures: Macular thickness measurements were assessed before and after correction of the algorithm by constructing Bland-Altman plots for agreement and calculating intraclass correlation coefficients (ICCs and coefficients of repeatability (COR to evaluate intraclass repeatability. Results: Spectralis had the highest number of images needing manual correction.  All machines had high ICCs, with Spectralis having the highest.  Also, Bland-Altman plots indicated that there was low agreement between Cirrus™ and Stratus™, Spectralis™ and Stratus™, while there was good agreement between the Cirrus™ and Spectralis™.  The CORs were lowest for SpectralisTM and similar and higher for CirrusTM and StratusTM.  Agreement, CORs, and ICCs generally improved after manual correction, but only minimally.  Conclusion: Agreement is low between devices, except between both SD-OCT machines.  Manual correction tends to improve results.

  11. Magni Reproducibility Example

    DEFF Research Database (Denmark)

    2016-01-01

    An example of how to use the magni.reproducibility package for storing metadata along with results from a computational experiment. The example is based on simulating the Mandelbrot set.......An example of how to use the magni.reproducibility package for storing metadata along with results from a computational experiment. The example is based on simulating the Mandelbrot set....

  12. Evaluation of multichannel reproduced sound

    DEFF Research Database (Denmark)

    Choisel, Sylvain; Wickelmaier, Florian Maria

    2007-01-01

    A study was conducted with the goal of quantifying auditory attributes which underlie listener preference for multichannel reproduced sound. Short musical excerpts were presented in mono, stereo and several multichannel formats to a panel of forty selected listeners. Scaling of auditory attributes......, as well as overall preference, was based on consistency tests of binary paired-comparison judgments and on modeling the choice frequencies using probabilistic choice models. As a result, the preferences of non-expert listeners could be measured reliably at a ratio scale level. Principal components derived...

  13. Preserve specimens for reproducibility

    Czech Academy of Sciences Publication Activity Database

    Krell, F.-T.; Klimeš, Petr; Rocha, L. A.; Fikáček, M.; Miller, S. E.

    2016-01-01

    Roč. 539, č. 7628 (2016), s. 168 ISSN 0028-0836 Institutional support: RVO:60077344 Keywords : reproducibility * specimen * biodiversity Subject RIV: EH - Ecology, Behaviour Impact factor: 40.137, year: 2016 http://www.nature.com/nature/journal/v539/n7628/full/539168b.html

  14. Reproducibility of ultrasonic testing

    International Nuclear Information System (INIS)

    Lecomte, J.-C.; Thomas, Andre; Launay, J.-P.; Martin, Pierre

    The reproducibility of amplitude quotations for both artificial and natural reflectors was studied for several combinations of instrument/search unit, all being of the same type. This study shows that in industrial inspection if a range of standardized equipment is used, a margin of error of about 6 decibels has to be taken into account (confidence interval of 95%). This margin is about 4 to 5 dB for natural or artificial defects located in the central area and about 6 to 7 dB for artificial defects located on the back surface. This lack of reproducibility seems to be attributable first to the search unit and then to the instrument and operator. These results were confirmed by analysis of calibration data obtained from 250 tests performed by 25 operators under shop conditions. The margin of error was higher than the 6 dB obtained in the study [fr

  15. Magnet stability and reproducibility

    CERN Document Server

    Marks, N

    2010-01-01

    Magnet stability and reproducibility have become increasingly important as greater precision and beams with smaller dimension are required for research, medical and other purpose. The observed causes of mechanical and electrical instability are introduced and the engineering arrangements needed to minimize these problems discussed; the resulting performance of a state-of-the-art synchrotron source (Diamond) is then presented. The need for orbit feedback to obtain best possible beam stability is briefly introduced, but omitting any details of the necessary technical equipment, which is outside the scope of the presentation.

  16. Reproducible research in palaeomagnetism

    Science.gov (United States)

    Lurcock, Pontus; Florindo, Fabio

    2015-04-01

    The reproducibility of research findings is attracting increasing attention across all scientific disciplines. In palaeomagnetism as elsewhere, computer-based analysis techniques are becoming more commonplace, complex, and diverse. Analyses can often be difficult to reproduce from scratch, both for the original researchers and for others seeking to build on the work. We present a palaeomagnetic plotting and analysis program designed to make reproducibility easier. Part of the problem is the divide between interactive and scripted (batch) analysis programs. An interactive desktop program with a graphical interface is a powerful tool for exploring data and iteratively refining analyses, but usually cannot operate without human interaction. This makes it impossible to re-run an analysis automatically, or to integrate it into a larger automated scientific workflow - for example, a script to generate figures and tables for a paper. In some cases the parameters of the analysis process itself are not saved explicitly, making it hard to repeat or improve the analysis even with human interaction. Conversely, non-interactive batch tools can be controlled by pre-written scripts and configuration files, allowing an analysis to be 'replayed' automatically from the raw data. However, this advantage comes at the expense of exploratory capability: iteratively improving an analysis entails a time-consuming cycle of editing scripts, running them, and viewing the output. Batch tools also tend to require more computer expertise from their users. PuffinPlot is a palaeomagnetic plotting and analysis program which aims to bridge this gap. First released in 2012, it offers both an interactive, user-friendly desktop interface and a batch scripting interface, both making use of the same core library of palaeomagnetic functions. We present new improvements to the program that help to integrate the interactive and batch approaches, allowing an analysis to be interactively explored and refined

  17. Reproducibility in a multiprocessor system

    Science.gov (United States)

    Bellofatto, Ralph A; Chen, Dong; Coteus, Paul W; Eisley, Noel A; Gara, Alan; Gooding, Thomas M; Haring, Rudolf A; Heidelberger, Philip; Kopcsay, Gerard V; Liebsch, Thomas A; Ohmacht, Martin; Reed, Don D; Senger, Robert M; Steinmacher-Burow, Burkhard; Sugawara, Yutaka

    2013-11-26

    Fixing a problem is usually greatly aided if the problem is reproducible. To ensure reproducibility of a multiprocessor system, the following aspects are proposed; a deterministic system start state, a single system clock, phase alignment of clocks in the system, system-wide synchronization events, reproducible execution of system components, deterministic chip interfaces, zero-impact communication with the system, precise stop of the system and a scan of the system state.

  18. Reliability engineering

    International Nuclear Information System (INIS)

    Lee, Chi Woo; Kim, Sun Jin; Lee, Seung Woo; Jeong, Sang Yeong

    1993-08-01

    This book start what is reliability? such as origin of reliability problems, definition of reliability and reliability and use of reliability. It also deals with probability and calculation of reliability, reliability function and failure rate, probability distribution of reliability, assumption of MTBF, process of probability distribution, down time, maintainability and availability, break down maintenance and preventive maintenance design of reliability, design of reliability for prediction and statistics, reliability test, reliability data and design and management of reliability.

  19. Reproducibility of scoring emphysema by HRCT

    International Nuclear Information System (INIS)

    Malinen, A.; Partanen, K.; Rytkoenen, H.; Vanninen, R.; Erkinjuntti-Pekkanen, R.

    2002-01-01

    Purpose: We evaluated the reproducibility of three visual scoring methods of emphysema and compared these methods with pulmonary function tests (VC, DLCO, FEV1 and FEV%) among farmer's lung patients and farmers. Material and Methods: Three radiologists examined high-resolution CT images of farmer's lung patients and their matched controls (n=70) for chronic interstitial lung diseases. Intraobserver reproducibility and interobserver variability were assessed for three methods: severity, Sanders' (extent) and Sakai. Pulmonary function tests as spirometry and diffusing capacity were measured. Results: Intraobserver -values for all three methods were good (0.51-0.74). Interobserver varied from 0.35 to 0.72. The Sanders' and the severity methods correlated strongly with pulmonary function tests, especially DLCO and FEV1. Conclusion: The Sanders' method proved to be reliable in evaluating emphysema, in terms of good consistency of interpretation and good correlation with pulmonary function tests

  20. Reproducibility of scoring emphysema by HRCT

    Energy Technology Data Exchange (ETDEWEB)

    Malinen, A.; Partanen, K.; Rytkoenen, H.; Vanninen, R. [Kuopio Univ. Hospital (Finland). Dept. of Clinical Radiology; Erkinjuntti-Pekkanen, R. [Kuopio Univ. Hospital (Finland). Dept. of Pulmonary Diseases

    2002-04-01

    Purpose: We evaluated the reproducibility of three visual scoring methods of emphysema and compared these methods with pulmonary function tests (VC, DLCO, FEV1 and FEV%) among farmer's lung patients and farmers. Material and Methods: Three radiologists examined high-resolution CT images of farmer's lung patients and their matched controls (n=70) for chronic interstitial lung diseases. Intraobserver reproducibility and interobserver variability were assessed for three methods: severity, Sanders' (extent) and Sakai. Pulmonary function tests as spirometry and diffusing capacity were measured. Results: Intraobserver -values for all three methods were good (0.51-0.74). Interobserver varied from 0.35 to 0.72. The Sanders' and the severity methods correlated strongly with pulmonary function tests, especially DLCO and FEV1. Conclusion: The Sanders' method proved to be reliable in evaluating emphysema, in terms of good consistency of interpretation and good correlation with pulmonary function tests.

  1. Additive Manufacturing: Reproducibility of Metallic Parts

    Directory of Open Access Journals (Sweden)

    Konda Gokuldoss Prashanth

    2017-02-01

    Full Text Available The present study deals with the properties of five different metals/alloys (Al-12Si, Cu-10Sn and 316L—face centered cubic structure, CoCrMo and commercially pure Ti (CP-Ti—hexagonal closed packed structure fabricated by selective laser melting. The room temperature tensile properties of Al-12Si samples show good consistency in results within the experimental errors. Similar reproducible results were observed for sliding wear and corrosion experiments. The other metal/alloy systems also show repeatable tensile properties, with the tensile curves overlapping until the yield point. The curves may then follow the same path or show a marginal deviation (~10 MPa until they reach the ultimate tensile strength and a negligible difference in ductility levels (of ~0.3% is observed between the samples. The results show that selective laser melting is a reliable fabrication method to produce metallic materials with consistent and reproducible properties.

  2. ITK: Enabling Reproducible Research and Open Science

    Directory of Open Access Journals (Sweden)

    Matthew Michael McCormick

    2014-02-01

    Full Text Available Reproducibility verification is essential to the practice of the scientific method. Researchers report their findings, which are strengthened as other independent groups in the scientific community share similar outcomes. In the many scientific fields where software has become a fundamental tool for capturing and analyzing data, this requirement of reproducibility implies that reliable and comprehensive software platforms and tools should be made available to the scientific community. The tools will empower them and the public to verify, through practice, the reproducibility of observations that are reported in the scientific literature.Medical image analysis is one of the fields in which the use of computational resources, both software and hardware, are an essential platform for performing experimental work. In this arena, the introduction of the Insight Toolkit (ITK in 1999 has transformed the field and facilitates its progress by accelerating the rate at which algorithmic implementations are developed, tested, disseminated and improved. By building on the efficiency and quality of open source methodologies, ITK has provided the medical image community with an effective platform on which to build a daily workflow that incorporates the true scientific practices of reproducibility verification.This article describes the multiple tools, methodologies, and practices that the ITK community has adopted, refined, and followed during the past decade, in order to become one of the research communities with the most modern reproducibility verification infrastructure. For example, 207 contributors have created over 2400 unit tests that provide over 84% code line test coverage. The Insight Journal, an open publication journal associated with the toolkit, has seen over 360,000 publication downloads. The median normalized closeness centrality, a measure of knowledge flow, resulting from the distributed peer code review system was high, 0.46.

  3. Contextual sensitivity in scientific reproducibility.

    Science.gov (United States)

    Van Bavel, Jay J; Mende-Siedlecki, Peter; Brady, William J; Reinero, Diego A

    2016-06-07

    In recent years, scientists have paid increasing attention to reproducibility. For example, the Reproducibility Project, a large-scale replication attempt of 100 studies published in top psychology journals found that only 39% could be unambiguously reproduced. There is a growing consensus among scientists that the lack of reproducibility in psychology and other fields stems from various methodological factors, including low statistical power, researcher's degrees of freedom, and an emphasis on publishing surprising positive results. However, there is a contentious debate about the extent to which failures to reproduce certain results might also reflect contextual differences (often termed "hidden moderators") between the original research and the replication attempt. Although psychologists have found extensive evidence that contextual factors alter behavior, some have argued that context is unlikely to influence the results of direct replications precisely because these studies use the same methods as those used in the original research. To help resolve this debate, we recoded the 100 original studies from the Reproducibility Project on the extent to which the research topic of each study was contextually sensitive. Results suggested that the contextual sensitivity of the research topic was associated with replication success, even after statistically adjusting for several methodological characteristics (e.g., statistical power, effect size). The association between contextual sensitivity and replication success did not differ across psychological subdisciplines. These results suggest that researchers, replicators, and consumers should be mindful of contextual factors that might influence a psychological process. We offer several guidelines for dealing with contextual sensitivity in reproducibility.

  4. The risk of bias in systematic reviews tool showed fair reliability and good construct validity.

    Science.gov (United States)

    Bühn, Stefanie; Mathes, Tim; Prengel, Peggy; Wegewitz, Uta; Ostermann, Thomas; Robens, Sibylle; Pieper, Dawid

    2017-11-01

    There is a movement from generic quality checklists toward a more domain-based approach in critical appraisal tools. This study aimed to report on a first experience with the newly developed risk of bias in systematic reviews (ROBIS) tool and compare it with A Measurement Tool to Assess Systematic Reviews (AMSTAR), that is, the most common used tool to assess methodological quality of systematic reviews while assessing validity, reliability, and applicability. Validation study with four reviewers based on 16 systematic reviews in the field of occupational health. Interrater reliability (IRR) of all four raters was highest for domain 2 (Fleiss' kappa κ = 0.56) and lowest for domain 4 (κ = 0.04). For ROBIS, median IRR was κ = 0.52 (range 0.13-0.88) for the experienced pair of raters compared to κ = 0.32 (range 0.12-0.76) for the less experienced pair of raters. The percentage of "yes" scores of each review of ROBIS ratings was strongly correlated with the AMSTAR ratings (r s  = 0.76; P = 0.01). ROBIS has fair reliability and good construct validity to assess the risk of bias in systematic reviews. More validation studies are needed to investigate reliability and applicability, in particular. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Contextual sensitivity in scientific reproducibility

    Science.gov (United States)

    Van Bavel, Jay J.; Mende-Siedlecki, Peter; Brady, William J.; Reinero, Diego A.

    2016-01-01

    In recent years, scientists have paid increasing attention to reproducibility. For example, the Reproducibility Project, a large-scale replication attempt of 100 studies published in top psychology journals found that only 39% could be unambiguously reproduced. There is a growing consensus among scientists that the lack of reproducibility in psychology and other fields stems from various methodological factors, including low statistical power, researcher’s degrees of freedom, and an emphasis on publishing surprising positive results. However, there is a contentious debate about the extent to which failures to reproduce certain results might also reflect contextual differences (often termed “hidden moderators”) between the original research and the replication attempt. Although psychologists have found extensive evidence that contextual factors alter behavior, some have argued that context is unlikely to influence the results of direct replications precisely because these studies use the same methods as those used in the original research. To help resolve this debate, we recoded the 100 original studies from the Reproducibility Project on the extent to which the research topic of each study was contextually sensitive. Results suggested that the contextual sensitivity of the research topic was associated with replication success, even after statistically adjusting for several methodological characteristics (e.g., statistical power, effect size). The association between contextual sensitivity and replication success did not differ across psychological subdisciplines. These results suggest that researchers, replicators, and consumers should be mindful of contextual factors that might influence a psychological process. We offer several guidelines for dealing with contextual sensitivity in reproducibility. PMID:27217556

  6. Testing Reproducibility in Earth Sciences

    Science.gov (United States)

    Church, M. A.; Dudill, A. R.; Frey, P.; Venditti, J. G.

    2017-12-01

    Reproducibility represents how closely the results of independent tests agree when undertaken using the same materials but different conditions of measurement, such as operator, equipment or laboratory. The concept of reproducibility is fundamental to the scientific method as it prevents the persistence of incorrect or biased results. Yet currently the production of scientific knowledge emphasizes rapid publication of previously unreported findings, a culture that has emerged from pressures related to hiring, publication criteria and funding requirements. Awareness and critique of the disconnect between how scientific research should be undertaken, and how it actually is conducted, has been prominent in biomedicine for over a decade, with the fields of economics and psychology more recently joining the conversation. The purpose of this presentation is to stimulate the conversation in earth sciences where, despite implicit evidence in widely accepted classifications, formal testing of reproducibility is rare.As a formal test of reproducibility, two sets of experiments were undertaken with the same experimental procedure, at the same scale, but in different laboratories. Using narrow, steep flumes and spherical glass beads, grain size sorting was examined by introducing fine sediment of varying size and quantity into a mobile coarse bed. The general setup was identical, including flume width and slope; however, there were some variations in the materials, construction and lab environment. Comparison of the results includes examination of the infiltration profiles, sediment mobility and transport characteristics. The physical phenomena were qualitatively reproduced but not quantitatively replicated. Reproduction of results encourages more robust research and reporting, and facilitates exploration of possible variations in data in various specific contexts. Following the lead of other fields, testing of reproducibility can be incentivized through changes to journal

  7. Reproducible Bioinformatics Research for Biologists

    Science.gov (United States)

    This book chapter describes the current Big Data problem in Bioinformatics and the resulting issues with performing reproducible computational research. The core of the chapter provides guidelines and summaries of current tools/techniques that a noncomputational researcher would need to learn to pe...

  8. Reproducibility of brain ADC histograms

    International Nuclear Information System (INIS)

    Steens, S.C.A.; Buchem, M.A. van; Admiraal-Behloul, F.; Schaap, J.A.; Hoogenraad, F.G.C.; Wheeler-Kingshott, C.A.M.; Tofts, P.S.; Cessie, S. le

    2004-01-01

    The aim of this study was to assess the effect of differences in acquisition technique on whole-brain apparent diffusion coefficient (ADC) histogram parameters, as well as to assess scan-rescan reproducibility. Diffusion-weighted imaging (DWI) was performed in 7 healthy subjects with b-values 0-800, 0-1000, and 0-1500 s/mm 2 and fluid-attenuated inversion recovery (FLAIR) DWI with b-values 0-1000 s/mm 2 . All sequences were repeated with and without repositioning. The peak location, peak height, and mean ADC of the ADC histograms and mean ADC of a region of interest (ROI) in the white matter were compared using paired-sample t tests. Scan-rescan reproducibility was assessed using paired-sample t tests, and repeatability coefficients were reported. With increasing maximum b-values, ADC histograms shifted to lower values, with an increase in peak height (p<0.01). With FLAIR DWI, the ADC histogram shifted to lower values with a significantly higher, narrower peak (p<0.01), although the ROI mean ADC showed no significant differences. For scan-rescan reproducibility, no significant differences were observed. Different DWI pulse sequences give rise to different ADC histograms. With a given pulse sequence, however, ADC histogram analysis is a robust and reproducible technique. Using FLAIR DWI, the partial-voluming effect of cerebrospinal fluid, and thus its confounding effect on histogram analyses, can be reduced

  9. Reliability Engineering

    International Nuclear Information System (INIS)

    Lee, Sang Yong

    1992-07-01

    This book is about reliability engineering, which describes definition and importance of reliability, development of reliability engineering, failure rate and failure probability density function about types of it, CFR and index distribution, IFR and normal distribution and Weibull distribution, maintainability and movability, reliability test and reliability assumption in index distribution type, normal distribution type and Weibull distribution type, reliability sampling test, reliability of system, design of reliability and functionality failure analysis by FTA.

  10. Modeling and evaluating repeatability and reproducibility of ordinal classifications

    NARCIS (Netherlands)

    de Mast, J.; van Wieringen, W.N.

    2010-01-01

    This paper argues that currently available methods for the assessment of the repeatability and reproducibility of ordinal classifications are not satisfactory. The paper aims to study whether we can modify a class of models from Item Response Theory, well established for the study of the reliability

  11. Reproducibility of a reaming test

    DEFF Research Database (Denmark)

    Pilny, Lukas; Müller, Pavel; De Chiffre, Leonardo

    2012-01-01

    The reproducibility of a reaming test was analysed to document its applicability as a performance test for cutting fluids. Reaming tests were carried out on a drilling machine using HSS reamers. Workpiece material was an austenitic stainless steel, machined using 4.75 m∙min-1 cutting speed and 0......). Process reproducibility was assessed as the ability of different operators to ensure a consistent rating of individual lubricants. Absolute average values as well as experimental standard deviations of the evaluation parameters were calculated, and uncertainty budgeting was performed. Results document...... a built-up edge occurrence hindering a robust evaluation of cutting fluid performance, if the data evaluation is based on surface finish only. Measurements of hole geometry provide documentation to recognize systematic error distorting the performance test....

  12. Reproducibility of a reaming test

    DEFF Research Database (Denmark)

    Pilny, Lukas; Müller, Pavel; De Chiffre, Leonardo

    2014-01-01

    The reproducibility of a reaming test was analysed to document its applicability as a performance test for cutting fluids. Reaming tests were carried out on a drilling machine using HSS reamers. Workpiece material was an austenitic stainless steel, machined using 4.75 m•min−1 cutting speed and 0......). Process reproducibility was assessed as the ability of different operators to ensure a consistent rating of individual lubricants. Absolute average values as well as experimental standard deviations of the evaluation parameters were calculated, and uncertainty budgeting was performed. Results document...... a built–up edge occurrence hindering a robust evaluation of cutting fluid performance, if the data evaluation is based on surface finish only. Measurements of hole geometry provide documentation to recognise systematic error distorting the performance test....

  13. Towards Reproducibility in Computational Hydrology

    Science.gov (United States)

    Hutton, Christopher; Wagener, Thorsten; Freer, Jim; Han, Dawei; Duffy, Chris; Arheimer, Berit

    2017-04-01

    Reproducibility is a foundational principle in scientific research. The ability to independently re-run an experiment helps to verify the legitimacy of individual findings, and evolve (or reject) hypotheses and models of how environmental systems function, and move them from specific circumstances to more general theory. Yet in computational hydrology (and in environmental science more widely) the code and data that produces published results are not regularly made available, and even if they are made available, there remains a multitude of generally unreported choices that an individual scientist may have made that impact the study result. This situation strongly inhibits the ability of our community to reproduce and verify previous findings, as all the information and boundary conditions required to set up a computational experiment simply cannot be reported in an article's text alone. In Hutton et al 2016 [1], we argue that a cultural change is required in the computational hydrological community, in order to advance and make more robust the process of knowledge creation and hypothesis testing. We need to adopt common standards and infrastructures to: (1) make code readable and re-useable; (2) create well-documented workflows that combine re-useable code together with data to enable published scientific findings to be reproduced; (3) make code and workflows available, easy to find, and easy to interpret, using code and code metadata repositories. To create change we argue for improved graduate training in these areas. In this talk we reflect on our progress in achieving reproducible, open science in computational hydrology, which are relevant to the broader computational geoscience community. In particular, we draw on our experience in the Switch-On (EU funded) virtual water science laboratory (http://www.switch-on-vwsl.eu/participate/), which is an open platform for collaboration in hydrological experiments (e.g. [2]). While we use computational hydrology as

  14. Methodological quality of meta-analyses on treatments for chronic obstructive pulmonary disease: a cross-sectional study using the AMSTAR (Assessing the Methodological Quality of Systematic Reviews) tool.

    Science.gov (United States)

    Ho, Robin S T; Wu, Xinyin; Yuan, Jinqiu; Liu, Siya; Lai, Xin; Wong, Samuel Y S; Chung, Vincent C H

    2015-01-08

    Meta-analysis (MA) of randomised trials is considered to be one of the best approaches for summarising high-quality evidence on the efficacy and safety of treatments. However, methodological flaws in MAs can reduce the validity of conclusions, subsequently impairing the quality of decision making. To assess the methodological quality of MAs on COPD treatments. A cross-sectional study on MAs of COPD trials. MAs published during 2000-2013 were sampled from the Cochrane Database of Systematic Reviews and Database of Abstracts of Reviews of Effect. Methodological quality was assessed using the validated AMSTAR (Assessing the Methodological Quality of Systematic Reviews) tool. Seventy-nine MAs were sampled. Only 18% considered the scientific quality of primary studies when formulating conclusions and 49% used appropriate meta-analytic methods to combine findings. The problems were particularly acute among MAs on pharmacological treatments. In 48% of MAs the authors did not report conflict of interest. Fifty-eight percent reported harmful effects of treatment. Publication bias was not assessed in 65% of MAs, and only 10% had searched non-English databases. The methodological quality of the included MAs was disappointing. Consideration of scientific quality when formulating conclusions should be made explicit. Future MAs should improve on reporting conflict of interest and harm, assessment of publication bias, prevention of language bias and use of appropriate meta-analytic methods.

  15. Reproducibility of isotope ratio measurements

    International Nuclear Information System (INIS)

    Elmore, D.

    1981-01-01

    The use of an accelerator as part of a mass spectrometer has improved the sensitivity for measuring low levels of long-lived radionuclides by several orders of magnitude. However, the complexity of a large tandem accelerator and beam transport system has made it difficult to match the precision of low energy mass spectrometry. Although uncertainties for accelerator measured isotope ratios as low as 1% have been obtained under favorable conditions, most errors quoted in the literature for natural samples are in the 5 to 20% range. These errors are dominated by statistics and generally the reproducibility is unknown since the samples are only measured once

  16. Shear wave elastography for breast masses is highly reproducible.

    Science.gov (United States)

    Cosgrove, David O; Berg, Wendie A; Doré, Caroline J; Skyba, Danny M; Henry, Jean-Pierre; Gay, Joel; Cohen-Bacrie, Claude

    2012-05-01

    To evaluate intra- and interobserver reproducibility of shear wave elastography (SWE) for breast masses. For intraobserver reproducibility, each observer obtained three consecutive SWE images of 758 masses that were visible on ultrasound. 144 (19%) were malignant. Weighted kappa was used to assess the agreement of qualitative elastographic features; the reliability of quantitative measurements was assessed by intraclass correlation coefficients (ICC). For the interobserver reproducibility, a blinded observer reviewed images and agreement on features was determined. Mean age was 50 years; mean mass size was 13 mm. Qualitatively, SWE images were at least reasonably similar for 666/758 (87.9%). Intraclass correlation for SWE diameter, area and perimeter was almost perfect (ICC ≥ 0.94). Intraobserver reliability for maximum and mean elasticity was almost perfect (ICC = 0.84 and 0.87) and was substantial for the ratio of mass-to-fat elasticity (ICC = 0.77). Interobserver agreement was moderate for SWE homogeneity (κ = 0.57), substantial for qualitative colour assessment of maximum elasticity (κ = 0.66), fair for SWE shape (κ = 0.40), fair for B-mode mass margins (κ = 0.38), and moderate for B-mode mass shape (κ = 0.58), orientation (κ = 0.53) and BI-RADS assessment (κ = 0.59). SWE is highly reproducible for assessing elastographic features of breast masses within and across observers. SWE interpretation is at least as consistent as that of BI-RADS ultrasound B-mode features. • Shear wave ultrasound elastography can measure the stiffness of breast tissue • It provides a qualitatively and quantitatively interpretable colour-coded map of tissue stiffness • Intraobserver reproducibility of SWE is almost perfect while intraobserver reproducibility of SWE proved to be moderate to substantial • The most reproducible SWE features between observers were SWE image homogeneity and maximum elasticity.

  17. Reproducibility of ECG-gated Ultrasound Diameter Assessment of Small Abdominal Aortic Aneurysms

    DEFF Research Database (Denmark)

    Bredahl, K; Eldrup, N; Meyer, C

    2013-01-01

    No standardised ultrasound procedure to obtain reliable growth estimates for abdominal aortic aneurysms (AAA) is currently available. We investigated the feasibility and reproducibility of a novel approach controlling for a combination of vessel wall delineation and cardiac cycle variation....

  18. Reproducibility of graph metrics in fMRI networks

    Directory of Open Access Journals (Sweden)

    Qawi K Telesford

    2010-12-01

    Full Text Available The reliability of graph metrics calculated in network analysis is essential to the interpretation of complex network organization. These graph metrics are used to deduce the small-world properties in networks. In this study, we investigated the test-retest reliability of graph metrics from functional magnetic resonance imaging (fMRI data collected for two runs in 45 healthy older adults. Graph metrics were calculated on data for both runs and compared using intraclass correlation coefficient (ICC statistics and Bland-Altman (BA plots. ICC scores describe the level of absolute agreement between two measurements and provide a measure of reproducibility. For mean graph metrics, ICC scores were high for clustering coefficient (ICC=0.86, global efficiency (ICC=0.83, path length (ICC=0.79, and local efficiency (ICC=0.75; the ICC score for degree was found to be low (ICC=0.29. ICC scores were also used to generate reproducibility maps in brain space to test voxel-wise reproducibility for unsmoothed and smoothed data. Reproducibility was uniform across the brain for global efficiency and path length, but was only high in network hubs for clustering coefficient, local efficiency and degree. BA plots were used to test the measurement repeatability of all graph metrics. All graph metrics fell within the limits for repeatability. Together, these results suggest that with exception of degree, mean graph metrics are reproducible and suitable for clinical studies. Further exploration is warranted to better understand reproducibility across the brain on a voxel-wise basis.

  19. Reproducibility of abdominal fat assessment by ultrasound and computed tomography.

    Science.gov (United States)

    Mauad, Fernando Marum; Chagas-Neto, Francisco Abaeté; Benedeti, Augusto César Garcia Saab; Nogueira-Barbosa, Marcello Henrique; Muglia, Valdair Francisco; Carneiro, Antonio Adilton Oliveira; Muller, Enrico Mattana; Elias Junior, Jorge

    2017-01-01

    To test the accuracy and reproducibility of ultrasound and computed tomography (CT) for the quantification of abdominal fat in correlation with the anthropometric, clinical, and biochemical assessments. Using ultrasound and CT, we determined the thickness of subcutaneous and intra-abdominal fat in 101 subjects-of whom 39 (38.6%) were men and 62 (61.4%) were women-with a mean age of 66.3 years (60-80 years). The ultrasound data were correlated with the anthropometric, clinical, and biochemical parameters, as well as with the areas measured by abdominal CT. Intra-abdominal thickness was the variable for which the correlation with the areas of abdominal fat was strongest (i.e., the correlation coefficient was highest). We also tested the reproducibility of ultrasound and CT for the assessment of abdominal fat and found that CT measurements of abdominal fat showed greater reproducibility, having higher intraobserver and interobserver reliability than had the ultrasound measurements. There was a significant correlation between ultrasound and CT, with a correlation coefficient of 0.71. In the assessment of abdominal fat, the intraobserver and interobserver reliability were greater for CT than for ultrasound, although both methods showed high accuracy and good reproducibility.

  20. Reproducibility of abdominal fat assessment by ultrasound and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Mauad, Fernando Marum; Chagas-Neto, Francisco Abaete; Benedeti, Augusto Cesar Garcia Saab; Nogueira-Barbosa, Marcello Henrique; Muglia, Valdair Francisco; Carneiro, Antonio Adilton Oliveira; Muller, Enrico Mattana; Elias Junior, Jorge, E-mail: fernando@fatesa.edu.br [Faculdade de Tecnologia em Saude (FATESA), Ribeirao Preto, SP (Brazil); Universidade de Fortaleza (UNIFOR), Fortaleza, CE (Brazil). Departmento de Radiologia; Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Departmento de Medicina Clinica; Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras; Hospital Mae de Deus, Porto Alegre, RS (Brazil)

    2017-05-15

    Objective: To test the accuracy and reproducibility of ultrasound and computed tomography (CT) for the quantification of abdominal fat in correlation with the anthropometric, clinical, and biochemical assessments. Materials and Methods: Using ultrasound and CT, we determined the thickness of subcutaneous and intra-abdominal fat in 101 subjects-of whom 39 (38.6%) were men and 62 (61.4%) were women-with a mean age of 66.3 years (60-80 years). The ultrasound data were correlated with the anthropometric, clinical, and biochemical parameters, as well as with the areas measured by abdominal CT. Results: Intra-abdominal thickness was the variable for which the correlation with the areas of abdominal fat was strongest (i.e., the correlation coefficient was highest). We also tested the reproducibility of ultrasound and CT for the assessment of abdominal fat and found that CT measurements of abdominal fat showed greater reproducibility, having higher intraobserver and interobserver reliability than had the ultrasound measurements. There was a significant correlation between ultrasound and CT, with a correlation coefficient of 0.71. Conclusion: In the assessment of abdominal fat, the intraobserver and interobserver reliability were greater for CT than for ultrasound, although both methods showed high accuracy and good reproducibility. (author)

  1. Reproducible research: a minority opinion

    Science.gov (United States)

    Drummond, Chris

    2018-01-01

    Reproducible research, a growing movement within many scientific fields, including machine learning, would require the code, used to generate the experimental results, be published along with any paper. Probably the most compelling argument for this is that it is simply following good scientific practice, established over the years by the greats of science. The implication is that failure to follow such a practice is unscientific, not a label any machine learning researchers would like to carry. It is further claimed that misconduct is causing a growing crisis of confidence in science. That, without this practice being enforced, science would inevitably fall into disrepute. This viewpoint is becoming ubiquitous but here I offer a differing opinion. I argue that far from being central to science, what is being promulgated is a narrow interpretation of how science works. I contend that the consequences are somewhat overstated. I would also contend that the effort necessary to meet the movement's aims, and the general attitude it engenders would not serve well any of the research disciplines, including our own.

  2. Software reliability

    CERN Document Server

    Bendell, A

    1986-01-01

    Software Reliability reviews some fundamental issues of software reliability as well as the techniques, models, and metrics used to predict the reliability of software. Topics covered include fault avoidance, fault removal, and fault tolerance, along with statistical methods for the objective assessment of predictive accuracy. Development cost models and life-cycle cost models are also discussed. This book is divided into eight sections and begins with a chapter on adaptive modeling used to predict software reliability, followed by a discussion on failure rate in software reliability growth mo

  3. Human reliability

    International Nuclear Information System (INIS)

    Embrey, D.E.

    1987-01-01

    Concepts and techniques of human reliability have been developed and are used mostly in probabilistic risk assessment. For this, the major application of human reliability assessment has been to identify the human errors which have a significant effect on the overall safety of the system and to quantify the probability of their occurrence. Some of the major issues within human reliability studies are reviewed and it is shown how these are applied to the assessment of human failures in systems. This is done under the following headings; models of human performance used in human reliability assessment, the nature of human error, classification of errors in man-machine systems, practical aspects, human reliability modelling in complex situations, quantification and examination of human reliability, judgement based approaches, holistic techniques and decision analytic approaches. (UK)

  4. Reliability Calculations

    DEFF Research Database (Denmark)

    Petersen, Kurt Erling

    1986-01-01

    Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety...... and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic...... approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very...

  5. Theory of reproducing kernels and applications

    CERN Document Server

    Saitoh, Saburou

    2016-01-01

    This book provides a large extension of the general theory of reproducing kernels published by N. Aronszajn in 1950, with many concrete applications. In Chapter 1, many concrete reproducing kernels are first introduced with detailed information. Chapter 2 presents a general and global theory of reproducing kernels with basic applications in a self-contained way. Many fundamental operations among reproducing kernel Hilbert spaces are dealt with. Chapter 2 is the heart of this book. Chapter 3 is devoted to the Tikhonov regularization using the theory of reproducing kernels with applications to numerical and practical solutions of bounded linear operator equations. In Chapter 4, the numerical real inversion formulas of the Laplace transform are presented by applying the Tikhonov regularization, where the reproducing kernels play a key role in the results. Chapter 5 deals with ordinary differential equations; Chapter 6 includes many concrete results for various fundamental partial differential equations. In Chapt...

  6. Towards reproducibility of research by reuse of IT best practices

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    Reproducibility of any research gives much higher credibility both to research results and to the researchers. This is true for any kind of research including computer science, where a lot of tools and approaches have been developed to ensure reproducibility. In this talk I will focus on basic and seemingly simple principles, which sometimes look too obvious to follow, but help researchers build beautiful and reliable systems that produce consistent, measurable results. My talk will cover, among other things, the problem of embedding machine learning techniques into analysis strategy. I will also speak about the most common pitfalls in this process and how to avoid them. In addition, I will demonstrate the research environment based on the principles that I will have outlined. About the speaker Andrey Ustyuzhanin (36) is Head of CERN partnership program at Yandex. He is involved in the development of event indexing and event filtering services which Yandex has been providing for the LHCb experiment sinc...

  7. Reproducibility of surface roughness in reaming

    DEFF Research Database (Denmark)

    Müller, Pavel; De Chiffre, Leonardo

    An investigation on the reproducibility of surface roughness in reaming was performed to document the applicability of this approach for testing cutting fluids. Austenitic stainless steel was used as a workpiece material and HSS reamers as cutting tools. Reproducibility of the results was evaluat...

  8. Reproducibility principles, problems, practices, and prospects

    CERN Document Server

    Maasen, Sabine

    2016-01-01

    Featuring peer-reviewed contributions from noted experts in their fields of research, Reproducibility: Principles, Problems, Practices, and Prospects presents state-of-the-art approaches to reproducibility, the gold standard sound science, from multi- and interdisciplinary perspectives. Including comprehensive coverage for implementing and reflecting the norm of reproducibility in various pertinent fields of research, the book focuses on how the reproducibility of results is applied, how it may be limited, and how such limitations can be understood or even controlled in the natural sciences, computational sciences, life sciences, social sciences, and studies of science and technology. The book presents many chapters devoted to a variety of methods and techniques, as well as their epistemic and ontological underpinnings, which have been developed to safeguard reproducible research and curtail deficits and failures. The book also investigates the political, historical, and social practices that underlie repro...

  9. Reliability Engineering

    CERN Document Server

    Lazzaroni, Massimo

    2012-01-01

    This book gives a practical guide for designers and users in Information and Communication Technology context. In particular, in the first Section, the definition of the fundamental terms according to the international standards are given. Then, some theoretical concepts and reliability models are presented in Chapters 2 and 3: the aim is to evaluate performance for components and systems and reliability growth. Chapter 4, by introducing the laboratory tests, puts in evidence the reliability concept from the experimental point of view. In ICT context, the failure rate for a given system can be

  10. Reliability training

    Science.gov (United States)

    Lalli, Vincent R. (Editor); Malec, Henry A. (Editor); Dillard, Richard B.; Wong, Kam L.; Barber, Frank J.; Barina, Frank J.

    1992-01-01

    Discussed here is failure physics, the study of how products, hardware, software, and systems fail and what can be done about it. The intent is to impart useful information, to extend the limits of production capability, and to assist in achieving low cost reliable products. A review of reliability for the years 1940 to 2000 is given. Next, a review of mathematics is given as well as a description of what elements contribute to product failures. Basic reliability theory and the disciplines that allow us to control and eliminate failures are elucidated.

  11. Intra-and interobserver reproducibility of shear wave elastography for evaluation of the breast lesions

    International Nuclear Information System (INIS)

    Hong, Min Ji; Kim, Hak Hee

    2017-01-01

    To evaluate reproducibility of shear wave elastography (SWE) for breast lesions within and between observers and compare the reproducibility of SWE features. For intraobserver reproducibility, 225 masses with 208 patients were included; and two consecutive SWE images were acquired by each observer. For interobserver reproducibility, SWE images of the same mass were obtained by another observer before surgery in 40 patients. Intraclass correlation coefficients (ICC) were used to determine intra- and interobserver reproducibility. Intraobserver reliability for mean elasticity (Emean) and maximum elasticity (Emax) were excellent (ICC = 0.803, 0.799). ICC for SWE ratio and minimum elasticity (Emin) were fair to good (ICC = 0.703, 0.539). Emean showed excellent ICC regardless of histopathologic type and tumor size. Emax, SWE ratio and Emin represented excellent or fair to good reproducibility based on histopathologic type and tumor size. In interobserver study, ICC for Emean, Emax and SWE ratio were excellent. Emean, Emax and SWE ratio represented excellent ICC irrespective of histopathologic type. ICC for Emean was excellent regardless of tumor size. SWE ratio and Emax showed fair to good interobserver reproducibility based on tumor size. Emin represented poor interobserver reliability. Emean in SWE was highly reproducible within and between observers

  12. Intra-and interobserver reproducibility of shear wave elastography for evaluation of the breast lesions

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Min Ji [Dept. of Radiology, Gil Hospital, Gachon University of Medicine and Science, Incheon (Korea, Republic of); Kim, Hak Hee [Dept. of Radiology, and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2017-03-15

    To evaluate reproducibility of shear wave elastography (SWE) for breast lesions within and between observers and compare the reproducibility of SWE features. For intraobserver reproducibility, 225 masses with 208 patients were included; and two consecutive SWE images were acquired by each observer. For interobserver reproducibility, SWE images of the same mass were obtained by another observer before surgery in 40 patients. Intraclass correlation coefficients (ICC) were used to determine intra- and interobserver reproducibility. Intraobserver reliability for mean elasticity (Emean) and maximum elasticity (Emax) were excellent (ICC = 0.803, 0.799). ICC for SWE ratio and minimum elasticity (Emin) were fair to good (ICC = 0.703, 0.539). Emean showed excellent ICC regardless of histopathologic type and tumor size. Emax, SWE ratio and Emin represented excellent or fair to good reproducibility based on histopathologic type and tumor size. In interobserver study, ICC for Emean, Emax and SWE ratio were excellent. Emean, Emax and SWE ratio represented excellent ICC irrespective of histopathologic type. ICC for Emean was excellent regardless of tumor size. SWE ratio and Emax showed fair to good interobserver reproducibility based on tumor size. Emin represented poor interobserver reliability. Emean in SWE was highly reproducible within and between observers.

  13. INFRARED IMAGING OF CARBON AND CERAMIC COMPOSITES: DATA REPRODUCIBILITY

    International Nuclear Information System (INIS)

    Knight, B.; Howard, D. R.; Ringermacher, H. I.; Hudson, L. D.

    2010-01-01

    Infrared NDE techniques have proven to be superior for imaging of flaws in ceramic matrix composites (CMC) and carbon silicon carbide composites (C/SiC). Not only can one obtain accurate depth gauging of flaws such as delaminations and layered porosity in complex-shaped components such as airfoils and other aeronautical components, but also excellent reproducibility of image data is obtainable using the STTOF (Synthetic Thermal Time-of-Flight) methodology. The imaging of large complex shapes is fast and reliable. This methodology as applied to large C/SiC flight components at the NASA Dryden Flight Research Center will be described.

  14. Infrared Imaging of Carbon and Ceramic Composites: Data Reproducibility

    Science.gov (United States)

    Knight, B.; Howard, D. R.; Ringermacher, H. I.; Hudson, L. D.

    2010-02-01

    Infrared NDE techniques have proven to be superior for imaging of flaws in ceramic matrix composites (CMC) and carbon silicon carbide composites (C/SiC). Not only can one obtain accurate depth gauging of flaws such as delaminations and layered porosity in complex-shaped components such as airfoils and other aeronautical components, but also excellent reproducibility of image data is obtainable using the STTOF (Synthetic Thermal Time-of-Flight) methodology. The imaging of large complex shapes is fast and reliable. This methodology as applied to large C/SiC flight components at the NASA Dryden Flight Research Center will be described.

  15. Reliability calculations

    International Nuclear Information System (INIS)

    Petersen, K.E.

    1986-03-01

    Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very complex systems. In order to increase the applicability of the programs variance reduction techniques can be applied to speed up the calculation process. Variance reduction techniques have been studied and procedures for implementation of importance sampling are suggested. (author)

  16. Systems reliability/structural reliability

    International Nuclear Information System (INIS)

    Green, A.E.

    1980-01-01

    The question of reliability technology using quantified techniques is considered for systems and structures. Systems reliability analysis has progressed to a viable and proven methodology whereas this has yet to be fully achieved for large scale structures. Structural loading variants over the half-time of the plant are considered to be more difficult to analyse than for systems, even though a relatively crude model may be a necessary starting point. Various reliability characteristics and environmental conditions are considered which enter this problem. The rare event situation is briefly mentioned together with aspects of proof testing and normal and upset loading conditions. (orig.)

  17. Learning Reproducibility with a Yearly Networking Contest

    KAUST Repository

    Canini, Marco

    2017-08-10

    Better reproducibility of networking research results is currently a major goal that the academic community is striving towards. This position paper makes the case that improving the extent and pervasiveness of reproducible research can be greatly fostered by organizing a yearly international contest. We argue that holding a contest undertaken by a plurality of students will have benefits that are two-fold. First, it will promote hands-on learning of skills that are helpful in producing artifacts at the replicable-research level. Second, it will advance the best practices regarding environments, testbeds, and tools that will aid the tasks of reproducibility evaluation committees by and large.

  18. The Economics of Reproducibility in Preclinical Research.

    Directory of Open Access Journals (Sweden)

    Leonard P Freedman

    2015-06-01

    Full Text Available Low reproducibility rates within life science research undermine cumulative knowledge production and contribute to both delays and costs of therapeutic drug development. An analysis of past studies indicates that the cumulative (total prevalence of irreproducible preclinical research exceeds 50%, resulting in approximately US$28,000,000,000 (US$28B/year spent on preclinical research that is not reproducible-in the United States alone. We outline a framework for solutions and a plan for long-term improvements in reproducibility rates that will help to accelerate the discovery of life-saving therapies and cures.

  19. Thou Shalt Be Reproducible! A Technology Perspective

    Directory of Open Access Journals (Sweden)

    Patrick Mair

    2016-07-01

    Full Text Available This article elaborates on reproducibility in psychology from a technological viewpoint. Modernopen source computational environments are shown and explained that foster reproducibilitythroughout the whole research life cycle, and to which emerging psychology researchers shouldbe sensitized, are shown and explained. First, data archiving platforms that make datasets publiclyavailable are presented. Second, R is advocated as the data-analytic lingua franca in psychologyfor achieving reproducible statistical analysis. Third, dynamic report generation environments forwriting reproducible manuscripts that integrate text, data analysis, and statistical outputs such asfigures and tables in a single document are described. Supplementary materials are provided inorder to get the reader started with these technologies.

  20. Static and Dynamic Handgrip Strength Endurance: Test-Retest Reproducibility.

    Science.gov (United States)

    Gerodimos, Vassilis; Karatrantou, Konstantina; Psychou, Dimitra; Vasilopoulou, Theodora; Zafeiridis, Andreas

    2017-03-01

    This study investigated the reliability of static and dynamic handgrip strength endurance using different protocols and indicators for the assessment of strength endurance. Forty young, healthy men and women (age, 18-22 years) performed 2 handgrip strength endurance protocols: a static protocol (sustained submaximal contraction at 50% of maximal voluntary contraction) and a dynamic one (8, 10, and 12 maximal repetitions). The participants executed each protocol twice to assess the test-retest reproducibility. Total work and total time were used as indicators of strength endurance in the static protocol; the strength recorded at each maximal repetition, the percentage change, and fatigue index were used as indicators of strength endurance in the dynamic protocol. The static protocol showed high reliability irrespective of sex and hand for total time and work. The 12-repetition dynamic protocol exhibited moderate-high reliability for repeated maximal repetitions and percentage change; the 8- and 10-repetition protocols demonstrated lower reliability irrespective of sex and hand. The fatigue index was not a reliable indicator for the assessment of dynamic handgrip endurance. Static handgrip endurance can be measured reliably using the total time and total work as indicators of strength endurance. For the evaluation of dynamic handgrip endurance, the 12-repetition protocol is recommended, using the repeated maximal repetitions and percentage change as indicators of strength endurance. Practitioners should consider the static (50% maximal voluntary contraction) and dynamic (12 repeated maximal repetitions) protocols as reliable for the assessment of handgrip strength endurance. The evaluation of static endurance in conjunction with dynamic endurance would provide more complete information about hand function. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  1. Navicular bone position determined by positional MRI: a reproducibility study

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Philip; Nybing, Janus D. [Copenhagen University Hospital Frederiksberg and Bispebjerg, Department of Radiology, Frederiksberg (Denmark); Johannsen, Finn E.; Stallknecht, Sandra E. [Copenhagen University Hospital Bispebjerg, Institute of Sports Medicine Copenhagen, Copenhagen, NV (Denmark); Hangaard, Stine; Hansen, Bjarke B. [Copenhagen University Hospital Frederiksberg, Parker Institute, Department of Rheumatology, Frederiksberg (Denmark); Boesen, Mikael [Copenhagen University Hospital Frederiksberg and Bispebjerg, Department of Radiology, Frederiksberg (Denmark); Copenhagen University Hospital Frederiksberg, Parker Institute, Department of Rheumatology, Frederiksberg (Denmark)

    2016-02-15

    To examine intraobserver, interobserver and between-day reproducibility of positional MRI for evaluation of navicular bone height (NVH) and medial navicular position (MNP). Positional MRI (pMRI) of the foot was performed on ten healthy participants (0.25 T G-scanner). Scanning was performed in supine and standing position, respectively. Two radiologists evaluated the images in a blinded manner. Reliability and agreement were assessed by calculation of intraclass correlation coefficient (ICC) and 95 % limits of agreement as a percentage of the mean (LOA%). Intraobserver and interobserver reliability was ''substantial'' in both supine and standing position (ICC 0.86-0.98) and showed good agreement (LOA% 4.9-14.7 %). Between-day reliability of navicular height and medial navicular position in standing position remained substantial (ICC 0.85-0.92) with adequate agreement (LOA% 8.3-19.8 %). In supine position between-day reliability was ''moderate'' for NVH (ICC 0.72) and ''slight'' for MNP (ICC 0.39). Agreement remained adequate between-days for MNP in supine position (LOA% 17.7 %), but it was less than adequate for NVH in supine position (LOA% 24.2 %). Navicular height and medial navicular position can be measured by pMRI in a very reproducible manner within and between observers. Increased measurement variation is observed between-days in supine position, which may be due to small positional differences or other unknown biomechanical factors. (orig.)

  2. Psychometric Evaluation of the Brachial Assessment Tool Part 1: Reproducibility.

    Science.gov (United States)

    Hill, Bridget; Williams, Gavin; Olver, John; Ferris, Scott; Bialocerkowski, Andrea

    2018-04-01

    To evaluate reproducibility (reliability and agreement) of the Brachial Assessment Tool (BrAT), a new patient-reported outcome measure for adults with traumatic brachial plexus injury (BPI). Prospective repeated-measure design. Outpatient clinics. Adults with confirmed traumatic BPI (N=43; age range, 19-82y). People with BPI completed the 31-item 4-response BrAT twice, 2 weeks apart. Results for the 3 subscales and summed score were compared at time 1 and time 2 to determine reliability, including systematic differences using paired t tests, test retest using intraclass correlation coefficient model 1,1 (ICC 1,1 ), and internal consistency using Cronbach α. Agreement parameters included standard error of measurement, minimal detectable change, and limits of agreement. BrAT. Test-retest reliability was excellent (ICC 1,1 =.90-.97). Internal consistency was high (Cronbach α=.90-.98). Measurement error was relatively low (standard error of measurement range, 3.1-8.8). A change of >4 for subscale 1, >6 for subscale 2, >4 for subscale 3, and >10 for the summed score is indicative of change over and above measurement error. Limits of agreement ranged from ±4.4 (subscale 3) to 11.61 (summed score). These findings support the use of the BrAT as a reproducible patient-reported outcome measure for adults with traumatic BPI with evidence of appropriate reliability and agreement for both individual and group comparisons. Further psychometric testing is required to establish the construct validity and responsiveness of the BrAT. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  3. Navicular bone position determined by positional MRI: a reproducibility study

    International Nuclear Information System (INIS)

    Hansen, Philip; Nybing, Janus D.; Johannsen, Finn E.; Stallknecht, Sandra E.; Hangaard, Stine; Hansen, Bjarke B.; Boesen, Mikael

    2016-01-01

    To examine intraobserver, interobserver and between-day reproducibility of positional MRI for evaluation of navicular bone height (NVH) and medial navicular position (MNP). Positional MRI (pMRI) of the foot was performed on ten healthy participants (0.25 T G-scanner). Scanning was performed in supine and standing position, respectively. Two radiologists evaluated the images in a blinded manner. Reliability and agreement were assessed by calculation of intraclass correlation coefficient (ICC) and 95 % limits of agreement as a percentage of the mean (LOA%). Intraobserver and interobserver reliability was ''substantial'' in both supine and standing position (ICC 0.86-0.98) and showed good agreement (LOA% 4.9-14.7 %). Between-day reliability of navicular height and medial navicular position in standing position remained substantial (ICC 0.85-0.92) with adequate agreement (LOA% 8.3-19.8 %). In supine position between-day reliability was ''moderate'' for NVH (ICC 0.72) and ''slight'' for MNP (ICC 0.39). Agreement remained adequate between-days for MNP in supine position (LOA% 17.7 %), but it was less than adequate for NVH in supine position (LOA% 24.2 %). Navicular height and medial navicular position can be measured by pMRI in a very reproducible manner within and between observers. Increased measurement variation is observed between-days in supine position, which may be due to small positional differences or other unknown biomechanical factors. (orig.)

  4. Examination of reproducibility in microbiological degredation experiments

    DEFF Research Database (Denmark)

    Sommer, Helle Mølgaard; Spliid, Henrik; Holst, Helle

    1998-01-01

    Experimental data indicate that certain microbiological degradation experiments have a limited reproducibility. Nine identical batch experiments were carried out on 3 different days to examine reproducibility. A pure culture, isolated from soil, grew with toluene as the only carbon and energy...... source. Toluene was degraded under aerobic conditions at a constant temperature of 28 degreesC. The experiments were modelled by a Monod model - extended to meet the air/liquid system, and the parameter values were estimated using a statistical nonlinear estimation procedure. Model reduction analysis...... resulted in a simpler model without the biomass decay term. In order to test for model reduction and reproducibility of parameter estimates, a likelihood ratio test was employed. The limited reproducibility for these experiments implied that all 9 batch experiments could not be described by the same set...

  5. Archiving Reproducible Research with R and Dataverse

    DEFF Research Database (Denmark)

    Leeper, Thomas

    2014-01-01

    Reproducible research and data archiving are increasingly important issues in research involving statistical analyses of quantitative data. This article introduces the dvn package, which allows R users to publicly archive datasets, analysis files, codebooks, and associated metadata in Dataverse...

  6. Human reliability

    International Nuclear Information System (INIS)

    Bubb, H.

    1992-01-01

    This book resulted from the activity of Task Force 4.2 - 'Human Reliability'. This group was established on February 27th, 1986, at the plenary meeting of the Technical Reliability Committee of VDI, within the framework of the joint committee of VDI on industrial systems technology - GIS. It is composed of representatives of industry, representatives of research institutes, of technical control boards and universities, whose job it is to study how man fits into the technical side of the world of work and to optimize this interaction. In a total of 17 sessions, information from the part of ergonomy dealing with human reliability in using technical systems at work was exchanged, and different methods for its evaluation were examined and analyzed. The outcome of this work was systematized and compiled in this book. (orig.) [de

  7. Microelectronics Reliability

    Science.gov (United States)

    2017-01-17

    inverters  connected in a chain. ................................................. 5  Figure 3  Typical graph showing frequency versus square root of...developing an experimental  reliability estimating methodology that could both illuminate the  lifetime  reliability of advanced devices,  circuits and...or  FIT of the device. In other words an accurate estimate of the device  lifetime  was found and thus the  reliability  that  can  be  conveniently

  8. Reproducing Epidemiologic Research and Ensuring Transparency.

    Science.gov (United States)

    Coughlin, Steven S

    2017-08-15

    Measures for ensuring that epidemiologic studies are reproducible include making data sets and software available to other researchers so they can verify published findings, conduct alternative analyses of the data, and check for statistical errors or programming errors. Recent developments related to the reproducibility and transparency of epidemiologic studies include the creation of a global platform for sharing data from clinical trials and the anticipated future extension of the global platform to non-clinical trial data. Government agencies and departments such as the US Department of Veterans Affairs Cooperative Studies Program have also enhanced their data repositories and data sharing resources. The Institute of Medicine and the International Committee of Medical Journal Editors released guidance on sharing clinical trial data. The US National Institutes of Health has updated their data-sharing policies. In this issue of the Journal, Shepherd et al. (Am J Epidemiol. 2017;186:387-392) outline a pragmatic approach for reproducible research with sensitive data for studies for which data cannot be shared because of legal or ethical restrictions. Their proposed quasi-reproducible approach facilitates the dissemination of statistical methods and codes to independent researchers. Both reproducibility and quasi-reproducibility can increase transparency for critical evaluation, further dissemination of study methods, and expedite the exchange of ideas among researchers. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. The Reproducibility of Nuclear Morphometric Measurements in Invasive Breast Carcinoma

    Directory of Open Access Journals (Sweden)

    Pauliina Kronqvist

    1997-01-01

    Full Text Available The intraobserver and interobserver reproducibility of computerized nuclear morphometry was determined in repeated measurements of 212 samples of invasive breast cancer. The influence of biological variation and the selection of the measurement area was also tested. Morphometrically determined mean nuclear profile area (Pearson’s r 0.89, grading efficiency (GE 0.95 and standard deviation (SD of nuclear profile area (Pearson’s r 0.84, GE 0.89 showed high reproducibility. In this respect, nuclear morphometry equals with other established methods of quantitative pathology and exceeds the results of subjective grading of nuclear atypia in invasive breast cancer. A training period of eight days was sufficient to produce clear improvement in consistency of nuclear morphometry results. By estimating the sources of variation it could be shown that the variation associated with the measurement procedure itself is small. Instead, sample associated variation is responsible for the majority of variation in the measurements (82.9% in mean nuclear profile area and 65.9% in SD of nuclear profile area. This study points out that when standardized methods are applied computerized morphometry is a reproducible and reliable method of assessing nuclear atypia in invasive breast cancer. For further improvement special emphasize should be put on sampling rules of selecting the microscope fields and measurement areas.

  10. Assessment of precision and reproducibility of a new myograph

    Directory of Open Access Journals (Sweden)

    Piepenbrock Siegfried

    2007-12-01

    Full Text Available Abstract Background The physiological characteristics of muscle activity and the assessment of muscle strength represent important diagnostic information. There are many devices that measure muscle force in humans, but some require voluntary contractions, which are difficult to assess in weak or unconscious patients who are unable to complete a full range of voluntary force assessment tasks. Other devices, which obtain standard muscle contractions by electric stimulations, do not have the technology required to induce and measure reproducible valid contractions at the optimum muscle length. Methods In our study we used a newly developed diagnostic device which measures accurately the reproducibility and time-changed-variability of the muscle force in an individual muscle. A total of 500 in-vivo measurements of supra-maximal isometric single twitch contractions were carried out on the musculus adductor pollicis of 5 test subjects over 10 sessions, with ten repetitions per session. The same protocol was performed on 405 test subjects with two repetitions each to determine a reference-interval on healthy subjects. Results Using our test setting, we found a high reproducibility of the muscle contractions of each test subject. The precision of the measurements performed with our device was 98.74%. Only two consecutive measurements are needed in order to assess a real, representative individual value of muscle force. The mean value of the force of contraction was 9.51 N and the 95% reference interval was 4.77–14.25 N. Conclusion The new myograph is a highly reliable measuring device with which the adductor pollicis can be investigated at the optimum length. It has the potential to become a reliable and valid tool for diagnostic in the clinical setting and for monitoring neuromuscular diseases.

  11. Repeat: a framework to assess empirical reproducibility in biomedical research

    Directory of Open Access Journals (Sweden)

    Leslie D. McIntosh

    2017-09-01

    Full Text Available Abstract Background The reproducibility of research is essential to rigorous science, yet significant concerns of the reliability and verifiability of biomedical research have been recently highlighted. Ongoing efforts across several domains of science and policy are working to clarify the fundamental characteristics of reproducibility and to enhance the transparency and accessibility of research. Methods The aim of the proceeding work is to develop an assessment tool operationalizing key concepts of research transparency in the biomedical domain, specifically for secondary biomedical data research using electronic health record data. The tool (RepeAT was developed through a multi-phase process that involved coding and extracting recommendations and practices for improving reproducibility from publications and reports across the biomedical and statistical sciences, field testing the instrument, and refining variables. Results RepeAT includes 119 unique variables grouped into five categories (research design and aim, database and data collection methods, data mining and data cleaning, data analysis, data sharing and documentation. Preliminary results in manually processing 40 scientific manuscripts indicate components of the proposed framework with strong inter-rater reliability, as well as directions for further research and refinement of RepeAT. Conclusions The use of RepeAT may allow the biomedical community to have a better understanding of the current practices of research transparency and accessibility among principal investigators. Common adoption of RepeAT may improve reporting of research practices and the availability of research outputs. Additionally, use of RepeAT will facilitate comparisons of research transparency and accessibility across domains and institutions.

  12. The reproducibility of single photon absorptiometry in a clinical setting

    International Nuclear Information System (INIS)

    Valkema, R.; Blokland, J.A.K.; Pauwels, E.K.J.; Papapoulos, S.E.; Bijvoet, O.L.M.

    1989-01-01

    The reproducibility of single photon absorptiometry (SPA) results for detection of changes in bone mineral content (BMC) was evaluated in a clinical setting. During a period of 18 months with 4 different sources, the calibration scans of an aluminium standard had a variation of less than 1% unless the activity of the 125 I source was low. The calibration procedure was performed weekly and this was sufficient to correct for drift of the system. The short term reproducibility in patients was assessed with 119 duplicate measurements made in direct succession. The best reproducibility (CV=1.35%) was found for fat corrected BMC results expressed in g/cm, obtained at the site proximal to the 8 mm space between the radius and ulna. Analysis of all SPA scans made during 1 year (487 scans) showed a failure of the automatic procedure to detect the space of 8 mm between the forearm bones in 19 scans (3.9%). A space adjacent to the ulnar styloid was taken as the site for the first scan in these examinations. This problem may be recognized and corrected relatively easy. A significant correlation was found between BMC at the lower arm and BMC of the lumbar spine assessed with dual photon absorptiometry. However, the error of estimation of proximal BMC (SEE=20%) and distal BMC (SEE=19.4%) made these measurements of little value to predict BMC at the lumbar spine in individuals. The short term reproducibility in patients combined with long term stability of the equipment in our clinical setting showed that SPA is a reliable technique to assess changes in bone mass at the lower arm of 4% between 2 measurements with a confidence level of 95%. (orig.)

  13. Reproducibility of central lumbar vertebral BMD

    International Nuclear Information System (INIS)

    Chan, F.; Pocock, N.; Griffiths, M.; Majerovic, Y.; Freund, J.

    1997-01-01

    Full text: Lumbar vertebral bone mineral density (BMD) using dual X-ray absorptiometry (DXA) has generally been calculated from a region of interest which includes the entire vertebral body. Although this region excludes part of the transverse processes, it does include the outer cortical shell of the vertebra. Recent software has been devised to calculate BMD in a central vertebral region of interest which excludes the outer cortical envelope. Theoretically this area may be more sensitive to detecting osteoporosis which affects trabecular bone to a greater extent than cortical bone. Apart from the sensitivity of BMD estimation, the reproducibility of any measurement is important owing to the slow rate of change of bone mass. We have evaluated the reproducibility of this new vertebral region of interest in 23 women who had duplicate lumbar spine DXA scans performed on the same day. The patients were repositioned between each measurement. Central vertebral analysis was performed for L2-L4 and the reproducibility of area, bone mineral content (BMC) and BMD calculated as the coefficient of variation; these values were compared with those from conventional analysis. Thus we have shown that the reproducibility of the central BMD is comparable to the conventional analysis which is essential if this technique is to provide any additional clinical data. The reasons for the decrease in reproducibility of the area and hence BMC requires further investigation

  14. Redefining reliability

    International Nuclear Information System (INIS)

    Paulson, S.L.

    1995-01-01

    Want to buy some reliability? The question would have been unthinkable in some markets served by the natural gas business even a few years ago, but in the new gas marketplace, industrial, commercial and even some residential customers have the opportunity to choose from among an array of options about the kind of natural gas service they need--and are willing to pay for. The complexities of this brave new world of restructuring and competition have sent the industry scrambling to find ways to educate and inform its customers about the increased responsibility they will have in determining the level of gas reliability they choose. This article discusses the new options and the new responsibilities of customers, the needed for continuous education, and MidAmerican Energy Company's experiment in direct marketing of natural gas

  15. Enacting the International/Reproducing Eurocentrism

    Directory of Open Access Journals (Sweden)

    Zeynep Gülşah Çapan

    Full Text Available Abstract This article focuses on the way in which Eurocentric conceptualisations of the ‘international’ are reproduced in different geopolitical contexts. Even though the Eurocentrism of International Relations has received growing attention, it has predominantly been concerned with unearthing the Eurocentrism of the ‘centre’, overlooking its varied manifestations in other geopolitical contexts. The article seeks to contribute to discussions about Eurocentrism by examining how different conceptualisations of the international are at work at a particular moment, and how these conceptualisations continue to reproduce Eurocentrism. It will focus on the way in which Eurocentric designations of spatial and temporal hierarchies were reproduced in the context of Turkey through a reading of how the ‘Gezi Park protests’ of 2013 and ‘Turkey’ itself were written into the story of the international.

  16. Reproducibility, controllability, and optimization of LENR experiments

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, David J. [The George Washington University, Washington DC 20052 (United States)

    2006-07-01

    Low-energy nuclear reaction (LENR) measurements are significantly, and increasingly reproducible. Practical control of the production of energy or materials by LENR has yet to be demonstrated. Minimization of costly inputs and maximization of desired outputs of LENR remain for future developments. The paper concludes by underlying that it is now clearly that demands for reproducible experiments in the early years of LENR experiments were premature. In fact, one can argue that irreproducibility should be expected for early experiments in a complex new field. As emphasized in the paper and as often happened in the history of science, experimental and theoretical progress can take even decades. It is likely to be many years before investments in LENR experiments will yield significant returns, even for successful research programs. However, it is clearly that a fundamental understanding of the anomalous effects observed in numerous experiments will significantly increase reproducibility, improve controllability, enable optimization of processes, and accelerate the economic viability of LENR.

  17. Reproducibility, controllability, and optimization of LENR experiments

    International Nuclear Information System (INIS)

    Nagel, David J.

    2006-01-01

    Low-energy nuclear reaction (LENR) measurements are significantly, and increasingly reproducible. Practical control of the production of energy or materials by LENR has yet to be demonstrated. Minimization of costly inputs and maximization of desired outputs of LENR remain for future developments. The paper concludes by underlying that it is now clearly that demands for reproducible experiments in the early years of LENR experiments were premature. In fact, one can argue that irreproducibility should be expected for early experiments in a complex new field. As emphasized in the paper and as often happened in the history of science, experimental and theoretical progress can take even decades. It is likely to be many years before investments in LENR experiments will yield significant returns, even for successful research programs. However, it is clearly that a fundamental understanding of the anomalous effects observed in numerous experiments will significantly increase reproducibility, improve controllability, enable optimization of processes, and accelerate the economic viability of LENR

  18. Undefined cellulase formulations hinder scientific reproducibility.

    Science.gov (United States)

    Himmel, Michael E; Abbas, Charles A; Baker, John O; Bayer, Edward A; Bomble, Yannick J; Brunecky, Roman; Chen, Xiaowen; Felby, Claus; Jeoh, Tina; Kumar, Rajeev; McCleary, Barry V; Pletschke, Brett I; Tucker, Melvin P; Wyman, Charles E; Decker, Stephen R

    2017-01-01

    In the shadow of a burgeoning biomass-to-fuels industry, biological conversion of lignocellulose to fermentable sugars in a cost-effective manner is key to the success of second-generation and advanced biofuel production. For the effective comparison of one cellulase preparation to another, cellulase assays are typically carried out with one or more engineered cellulase formulations or natural exoproteomes of known performance serving as positive controls. When these formulations have unknown composition, as is the case with several widely used commercial products, it becomes impossible to compare or reproduce work done today to work done in the future, where, for example, such preparations may not be available. Therefore, being a critical tenet of science publishing, experimental reproducibility is endangered by the continued use of these undisclosed products. We propose the introduction of standard procedures and materials to produce specific and reproducible cellulase formulations. These formulations are to serve as yardsticks to measure improvements and performance of new cellulase formulations.

  19. Reproducibility of somatosensory spatial perceptual maps.

    Science.gov (United States)

    Steenbergen, Peter; Buitenweg, Jan R; Trojan, Jörg; Veltink, Peter H

    2013-02-01

    Various studies have shown subjects to mislocalize cutaneous stimuli in an idiosyncratic manner. Spatial properties of individual localization behavior can be represented in the form of perceptual maps. Individual differences in these maps may reflect properties of internal body representations, and perceptual maps may therefore be a useful method for studying these representations. For this to be the case, individual perceptual maps need to be reproducible, which has not yet been demonstrated. We assessed the reproducibility of localizations measured twice on subsequent days. Ten subjects participated in the experiments. Non-painful electrocutaneous stimuli were applied at seven sites on the lower arm. Subjects localized the stimuli on a photograph of their own arm, which was presented on a tablet screen overlaying the real arm. Reproducibility was assessed by calculating intraclass correlation coefficients (ICC) for the mean localizations of each electrode site and the slope and offset of regression models of the localizations, which represent scaling and displacement of perceptual maps relative to the stimulated sites. The ICCs of the mean localizations ranged from 0.68 to 0.93; the ICCs of the regression parameters were 0.88 for the intercept and 0.92 for the slope. These results indicate a high degree of reproducibility. We conclude that localization patterns of non-painful electrocutaneous stimuli on the arm are reproducible on subsequent days. Reproducibility is a necessary property of perceptual maps for these to reflect properties of a subject's internal body representations. Perceptual maps are therefore a promising method for studying body representations.

  20. [Natural head position's reproducibility on photographs].

    Science.gov (United States)

    Eddo, Marie-Line; El Hayeck, Émilie; Hoyeck, Maha; Khoury, Élie; Ghoubril, Joseph

    2017-12-01

    The purpose of this study is to evaluate the reproducibility of natural head position with time on profile photographs. Our sample is composed of 96 students (20-30 years old) at the department of dentistry of Saint Joseph University in Beirut. Two profile photographs were taken in natural head position about a week apart. No significant differences were found between T0 and T1 (E = 1.065°). Many studies confirmed this reproducibility with time. Natural head position can be adopted as an orientation for profile photographs in orthodontics. © EDP Sciences, SFODF, 2017.

  1. Highly reproducible polyol synthesis for silver nanocubes

    Science.gov (United States)

    Han, Hye Ji; Yu, Taekyung; Kim, Woo-Sik; Im, Sang Hyuk

    2017-07-01

    We could synthesize the Ag nanocubes highly reproducibly by conducting the polyol synthesis using HCl etchant in dark condition because the photodecomposition/photoreduction of AgCl nanoparticles formed at initial reaction stage were greatly depressed and consequently the selective self-nucleation of Ag single crystals and their selective growth reaction could be promoted. Whereas the reproducibility of the formation of Ag nanocubes were very poor when we synthesize the Ag nanocubes in light condition due to the photoreduction of AgCl to Ag.

  2. Reproducible statistical analysis with multiple languages

    DEFF Research Database (Denmark)

    Lenth, Russell; Højsgaard, Søren

    2011-01-01

    This paper describes the system for making reproducible statistical analyses. differs from other systems for reproducible analysis in several ways. The two main differences are: (1) Several statistics programs can be in used in the same document. (2) Documents can be prepared using OpenOffice or ......Office or \\LaTeX. The main part of this paper is an example showing how to use and together in an OpenOffice text document. The paper also contains some practical considerations on the use of literate programming in statistics....

  3. Reproducing kernel Hilbert spaces of Gaussian priors

    NARCIS (Netherlands)

    Vaart, van der A.W.; Zanten, van J.H.; Clarke, B.; Ghosal, S.

    2008-01-01

    We review definitions and properties of reproducing kernel Hilbert spaces attached to Gaussian variables and processes, with a view to applications in nonparametric Bayesian statistics using Gaussian priors. The rate of contraction of posterior distributions based on Gaussian priors can be described

  4. Reproducibility of the results in ultrasonic testing

    International Nuclear Information System (INIS)

    Chalaye, M.; Launay, J.P.; Thomas, A.

    1980-12-01

    This memorandum reports on the conclusions of the tests carried out in order to evaluate the reproducibility of ultrasonic tests made on welded joints. FRAMATOME have started a study to assess the dispersion of results afforded by the test line and to characterize its behaviour. The tests covered sensors and ultrasonic generators said to be identical to each other (same commercial batch) [fr

  5. Reproducibility in Computational Neuroscience Models and Simulations

    Science.gov (United States)

    McDougal, Robert A.; Bulanova, Anna S.; Lytton, William W.

    2016-01-01

    Objective Like all scientific research, computational neuroscience research must be reproducible. Big data science, including simulation research, cannot depend exclusively on journal articles as the method to provide the sharing and transparency required for reproducibility. Methods Ensuring model reproducibility requires the use of multiple standard software practices and tools, including version control, strong commenting and documentation, and code modularity. Results Building on these standard practices, model sharing sites and tools have been developed that fit into several categories: 1. standardized neural simulators, 2. shared computational resources, 3. declarative model descriptors, ontologies and standardized annotations; 4. model sharing repositories and sharing standards. Conclusion A number of complementary innovations have been proposed to enhance sharing, transparency and reproducibility. The individual user can be encouraged to make use of version control, commenting, documentation and modularity in development of models. The community can help by requiring model sharing as a condition of publication and funding. Significance Model management will become increasingly important as multiscale models become larger, more detailed and correspondingly more difficult to manage by any single investigator or single laboratory. Additional big data management complexity will come as the models become more useful in interpreting experiments, thus increasing the need to ensure clear alignment between modeling data, both parameters and results, and experiment. PMID:27046845

  6. Estimating the reproducibility of psychological science

    NARCIS (Netherlands)

    Aarts, Alexander A.; Anderson, Joanna E.; Anderson, Christopher J.; Attridge, Peter R.; Attwood, Angela; Axt, Jordan; Babel, Molly; Bahnik, Stepan; Baranski, Erica; Barnett-Cowan, Michael; Bartmess, Elizabeth; Beer, Jennifer; Bell, Raoul; Bentley, Heather; Beyan, Leah; Binion, Grace; Borsboom, Denny; Bosch, Annick; Bosco, Frank A.; Bowman, Sara D.; Brandt, Mark J.; Braswell, Erin; Brohmer, Hilmar; Brown, Benjamin T.; Brown, Kristina; Bruening, Jovita; Calhoun-Sauls, Ann; Chagnon, Elizabeth; Callahan, Shannon P.; Chandler, Jesse; Chartier, Christopher R.; Cheung, Felix; Cillessen, Linda; Christopherson, Cody D.; Clay, Russ; Cleary, Hayley; Cloud, Mark D.; Cohn, Michael; Cohoon, Johanna; Columbus, Simon; Cordes, Andreas; Costantini, Giulio; Hartgerink, Chris; Krijnen, Job; Nuijten, Michele B.; van 't Veer, Anna E.; Van Aert, Robbie; van Assen, M.A.L.M.; Wissink, Joeri; Zeelenberg, Marcel

    2015-01-01

    INTRODUCTION Reproducibility is a defining feature of science, but the extent to which it characterizes current research is unknown. Scientific claims should not gain credence because of the status or authority of their originator but by the replicability of their supporting evidence. Even research

  7. Reproducibility, Controllability, and Optimization of Lenr Experiments

    Science.gov (United States)

    Nagel, David J.

    2006-02-01

    Low-energy nuclear reaction (LENR) measurements are significantly and increasingly reproducible. Practical control of the production of energy or materials by LENR has yet to be demonstrated. Minimization of costly inputs and maximization of desired outputs of LENR remain for future developments.

  8. Estimating the reproducibility of psychological science

    NARCIS (Netherlands)

    Anderson, Joanna E.; Aarts, Alexander A.; Anderson, Christopher J.; Attridge, Peter R.; Attwood, Angela; Axt, Jordan; Babel, Molly; Bahník, Štěpán; Baranski, Erica; Barnett-Cowan, Michael; Bartmess, Elizabeth; Beer, Jennifer; Bell, Raoul; Bentley, Heather; Beyan, Leah; Binion, Grace; Borsboom, Denny; Bosch, Annick; Bosco, Frank A.; Bowman, Sara D.; Brandt, Mark J.; Braswell, Erin; Brohmer, Hilmar; Brown, Benjamin T.; Brown, Kristina; Brüning, Jovita; Calhoun-Sauls, Ann; Callahan, Shannon P.; Chagnon, Elizabeth; Chandler, Jesse; Chartier, Christopher R.; Cheung, Felix; Christopherson, Cody D.; Cillessen, Linda; Clay, Russ; Cleary, Hayley; Cloud, Mark D.; Conn, Michael; Cohoon, Johanna; Columbus, Simon; Cordes, Andreas; Costantini, Giulio; Alvarez, Leslie D Cramblet; Cremata, Ed; Crusius, Jan; DeCoster, Jamie; DeGaetano, Michelle A.; Penna, Nicolás Delia; Den Bezemer, Bobby; Deserno, Marie K.; Devitt, Olivia; Dewitte, Laura; Dobolyi, David G.; Dodson, Geneva T.; Donnellan, M. Brent; Donohue, Ryan; Dore, Rebecca A.; Dorrough, Angela; Dreber, Anna; Dugas, Michelle; Dunn, Elizabeth W.; Easey, Kayleigh; Eboigbe, Sylvia; Eggleston, Casey; Embley, Jo; Epskamp, Sacha; Errington, Timothy M.; Estel, Vivien; Farach, Frank J.; Feather, Jenelle; Fedor, Anna; Fernández-Castilla, Belén; Fiedler, Susann; Field, James G.; Fitneva, Stanka A.; Flagan, Taru; Forest, Amanda L.; Forsell, Eskil; Foster, Joshua D.; Frank, Michael C.; Frazier, Rebecca S.; Fuchs, Heather; Gable, Philip; Galak, Jeff; Galliani, Elisa Maria; Gampa, Anup; Garcia, Sara; Gazarian, Douglas; Gilbert, Elizabeth; Giner-Sorolla, Roger; Glöckner, Andreas; Goellner, Lars; Goh, Jin X.; Goldberg, Rebecca; Goodbourn, Patrick T.; Gordon-McKeon, Shauna; Gorges, Bryan; Gorges, Jessie; Goss, Justin; Graham, Jesse; Grange, James A.; Gray, Jeremy; Hartgerink, Chris; Hartshorne, Joshua; Hasselman, Fred; Hayes, Timothy; Heikensten, Emma; Henninger, Felix; Hodsoll, John; Holubar, Taylor; Hoogendoorn, Gea; Humphries, Denise J.; Hung, Cathy O Y; Immelman, Nathali; Irsik, Vanessa C.; Jahn, Georg; Jäkel, Frank; Jekel, Marc; Johannesson, Magnus; Johnson, Larissa G.; Johnson, David J.; Johnson, Kate M.; Johnston, William J.; Jonas, Kai; Joy-Gaba, Jennifer A.; Kappes, Heather Barry; Kelso, Kim; Kidwell, Mallory C.; Kim, Seung Kyung; Kirkhart, Matthew; Kleinberg, Bennett; Knežević, Goran; Kolorz, Franziska Maria; Kossakowski, Jolanda J.; Krause, Robert Wilhelm; Krijnen, Job; Kuhlmann, Tim; Kunkels, Yoram K.; Kyc, Megan M.; Lai, Calvin K.; Laique, Aamir; Lakens, Daniël|info:eu-repo/dai/nl/298811855; Lane, Kristin A.; Lassetter, Bethany; Lazarević, Ljiljana B.; Le Bel, Etienne P.; Lee, Key Jung; Lee, Minha; Lemm, Kristi; Levitan, Carmel A.; Lewis, Melissa; Lin, Lin; Lin, Stephanie; Lippold, Matthias; Loureiro, Darren; Luteijn, Ilse; MacKinnon, Sean; Mainard, Heather N.; Marigold, Denise C.; Martin, Daniel P.; Martinez, Tylar; Masicampo, E. J.; Matacotta, Josh; Mathur, Maya; May, Michael; Mechin, Nicole; Mehta, Pranjal; Meixner, Johannes; Melinger, Alissa; Miller, Jeremy K.; Miller, Mallorie; Moore, Katherine; Möschl, Marcus; Motyl, Matt; Müller, Stephanie M.; Munafo, Marcus; Neijenhuijs, Koen I.; Nervi, Taylor; Nicolas, Gandalf; Nilsonne, Gustav; Nosek, Brian A.; Nuijten, Michèle B.; Olsson, Catherine; Osborne, Colleen; Ostkamp, Lutz; Pavel, Misha; Penton-Voak, Ian S.; Perna, Olivia; Pernet, Cyril; Perugini, Marco; Pipitone, R. Nathan; Pitts, Michael; Plessow, Franziska; Prenoveau, Jason M.; Rahal, Rima Maria; Ratliff, Kate A.; Reinhard, David; Renkewitz, Frank; Ricker, Ashley A.; Rigney, Anastasia; Rivers, Andrew M.; Roebke, Mark; Rutchick, Abraham M.; Ryan, Robert S.; Sahin, Onur; Saide, Anondah; Sandstrom, Gillian M.; Santos, David; Saxe, Rebecca; Schlegelmilch, René; Schmidt, Kathleen; Scholz, Sabine; Seibel, Larissa; Selterman, Dylan Faulkner; Shaki, Samuel; Simpson, William B.; Sinclair, H. Colleen; Skorinko, Jeanine L M; Slowik, Agnieszka; Snyder, Joel S.; Soderberg, Courtney; Sonnleitner, Carina; Spencer, Nick; Spies, Jeffrey R.; Steegen, Sara; Stieger, Stefan; Strohminger, Nina; Sullivan, Gavin B.; Talhelm, Thomas; Tapia, Megan; Te Dorsthorst, Anniek; Thomae, Manuela; Thomas, Sarah L.; Tio, Pia; Traets, Frits; Tsang, Steve; Tuerlinckx, Francis; Turchan, Paul; Valášek, Milan; Van't Veer, Anna E.; Van Aert, Robbie; Van Assen, Marcel|info:eu-repo/dai/nl/407629971; Van Bork, Riet; Van De Ven, Mathijs; Van Den Bergh, Don; Van Der Hulst, Marije; Van Dooren, Roel; Van Doorn, Johnny; Van Renswoude, Daan R.; Van Rijn, Hedderik; Vanpaemel, Wolf; Echeverría, Alejandro Vásquez; Vazquez, Melissa; Velez, Natalia; Vermue, Marieke; Verschoor, Mark; Vianello, Michelangelo; Voracek, Martin; Vuu, Gina; Wagenmakers, Eric Jan; Weerdmeester, Joanneke; Welsh, Ashlee; Westgate, Erin C.; Wissink, Joeri; Wood, Michael; Woods, Andy; Wright, Emily; Wu, Sining; Zeelenberg, Marcel; Zuni, Kellylynn

    2015-01-01

    Reproducibility is a defining feature of science, but the extent to which it characterizes current research is unknown. We conducted replications of 100 experimental and correlational studies published in three psychology journals using high-powered designs and original materials when available.

  9. Inter-examiner reproducibility of tests for lumbar motor control

    Directory of Open Access Journals (Sweden)

    Elkjaer Arne

    2011-05-01

    Full Text Available Abstract Background Many studies show a relation between reduced lumbar motor control (LMC and low back pain (LBP. However, test circumstances vary and during test performance, subjects may change position. In other words, the reliability - i.e. reproducibility and validity - of tests for LMC should be based on quantitative data. This has not been considered before. The aim was to analyse the reproducibility of five different quantitative tests for LMC commonly used in daily clinical practice. Methods The five tests for LMC were: repositioning (RPS, sitting forward lean (SFL, sitting knee extension (SKE, and bent knee fall out (BKFO, all measured in cm, and leg lowering (LL, measured in mm Hg. A total of 40 subjects (14 males, 26 females 25 with and 15 without LBP, with a mean age of 46.5 years (SD 14.8, were examined independently and in random order by two examiners on the same day. LBP subjects were recruited from three physiotherapy clinics with a connection to the clinic's gym or back-school. Non-LBP subjects were recruited from the clinic's staff acquaintances, and from patients without LBP. Results The means and standard deviations for each of the tests were 0.36 (0.27 cm for RPS, 1.01 (0.62 cm for SFL, 0.40 (0.29 cm for SKE, 1.07 (0.52 cm for BKFO, and 32.9 (7.1 mm Hg for LL. All five tests for LMC had reproducibility with the following ICCs: 0.90 for RPS, 0.96 for SFL, 0.96 for SKE, 0.94 for BKFO, and 0.98 for LL. Bland and Altman plots showed that most of the differences between examiners A and B were less than 0.20 cm. Conclusion These five tests for LMC displayed excellent reproducibility. However, the diagnostic accuracy of these tests needs to be addressed in larger cohorts of subjects, establishing values for the normal population. Also cut-points between subjects with and without LBP must be determined, taking into account age, level of activity, degree of impairment and participation in sports. Whether reproducibility of these

  10. Cervical vertebrae maturation method morphologic criteria: poor reproducibility.

    Science.gov (United States)

    Nestman, Trenton S; Marshall, Steven D; Qian, Fang; Holton, Nathan; Franciscus, Robert G; Southard, Thomas E

    2011-08-01

    The cervical vertebrae maturation (CVM) method has been advocated as a predictor of peak mandibular growth. A careful review of the literature showed potential methodologic errors that might influence the high reported reproducibility of the CVM method, and we recently established that the reproducibility of the CVM method was poor when these potential errors were eliminated. The purpose of this study was to further investigate the reproducibility of the individual vertebral patterns. In other words, the purpose was to determine which of the individual CVM vertebral patterns could be classified reliably and which could not. Ten practicing orthodontists, trained in the CVM method, evaluated the morphology of cervical vertebrae C2 through C4 from 30 cephalometric radiographs using questions based on the CVM method. The Fleiss kappa statistic was used to assess interobserver agreement when evaluating each cervical vertebrae morphology question for each subject. The Kendall coefficient of concordance was used to assess the level of interobserver agreement when determining a "derived CVM stage" for each subject. Interobserver agreement was high for assessment of the lower borders of C2, C3, and C4 that were either flat or curved in the CVM method, but interobserver agreement was low for assessment of the vertebral bodies of C3 and C4 when they were either trapezoidal, rectangular horizontal, square, or rectangular vertical; this led to the overall poor reproducibility of the CVM method. These findings were reflected in the Fleiss kappa statistic. Furthermore, nearly 30% of the time, individual morphologic criteria could not be combined to generate a final CVM stage because of incompatible responses to the 5 questions. Intraobserver agreement in this study was only 62%, on average, when the inconclusive stagings were excluded as disagreements. Intraobserver agreement was worse (44%) when the inconclusive stagings were included as disagreements. For the group of subjects

  11. A PHYSICAL ACTIVITY QUESTIONNAIRE: REPRODUCIBILITY AND VALIDITY

    Directory of Open Access Journals (Sweden)

    Nicolas Barbosa

    2007-12-01

    Full Text Available This study evaluates the Quantification de L'Activite Physique en Altitude chez les Enfants (QAPACE supervised self-administered questionnaire reproducibility and validity on the estimation of the mean daily energy expenditure (DEE on Bogotá's schoolchildren. The comprehension was assessed on 324 students, whereas the reproducibility was studied on a different random sample of 162 who were exposed twice to it. Reproducibility was assessed using both the Bland-Altman plot and the intra-class correlation coefficient (ICC. The validity was studied in a sample of 18 girls and 18 boys randomly selected, which completed the test - re-test study. The DEE derived from the questionnaire was compared with the laboratory measurement results of the peak oxygen uptake (Peak VO2 from ergo-spirometry and Leger Test. The reproducibility ICC was 0.96 (95% C.I. 0.95-0.97; by age categories 8-10, 0.94 (0.89-0. 97; 11-13, 0.98 (0.96- 0.99; 14-16, 0.95 (0.91-0.98. The ICC between mean TEE as estimated by the questionnaire and the direct and indirect Peak VO2 was 0.76 (0.66 (p<0.01; by age categories, 8-10, 11-13, and 14-16 were 0.89 (0.87, 0.76 (0.78 and 0.88 (0.80 respectively. The QAPACE questionnaire is reproducible and valid for estimating PA and showed a high correlation with the Peak VO2 uptake

  12. Intrasubject reproducibility of presurgical language lateralization and mapping using fMRI.

    NARCIS (Netherlands)

    Fernandez, G.S.E.; Specht, K.; Weis, S.; Tendolkar, I.; Reuber, M.; Fell, J.; Klaver, P.; Ruhlmann, J.; Reul, J.; Elger, C.E.

    2003-01-01

    BACKGROUND: fMRI is becoming a standard tool for the presurgical lateralization and mapping of brain areas involved in language processing. However, its within-subject reproducibility has yet to be fully explored. OBJECTIVE: To evaluate within-test and test-retest reliability of language fMRI in

  13. Low reproducibility of maximum urinary flow rate determined by portable flowmetry

    NARCIS (Netherlands)

    Sonke, G. S.; Kiemeney, L. A.; Verbeek, A. L.; Kortmann, B. B.; Debruyne, F. M.; de la Rosette, J. J.

    1999-01-01

    To evaluate the reproducibility in maximum urinary flow rate (Qmax) in men with lower urinary tract symptoms (LUTSs) and to determine the number of flows needed to obtain a specified reliability in mean Qmax, 212 patients with LUTSs (mean age, 62 years) referred to the University Hospital Nijmegen,

  14. Does systematic variation improve the reproducibility of animal experiments?

    NARCIS (Netherlands)

    Jonker, R.M.; Guenther, A.; Engqvist, L.; Schmoll, T.

    2013-01-01

    Reproducibility of results is a fundamental tenet of science. In this journal, Richter et al.1 tested whether systematic variation in experimental conditions (heterogenization) affects the reproducibility of results. Comparing this approach with the current standard of ensuring reproducibility

  15. Reproducibility in light microscopy: Maintenance, standards and SOPs.

    Science.gov (United States)

    Deagle, Rebecca C; Wee, Tse-Luen Erika; Brown, Claire M

    2017-08-01

    Light microscopy has grown to be a valuable asset in both the physical and life sciences. It is a highly quantitative method available in individual research laboratories and often centralized in core facilities. However, although quantitative microscopy is becoming a customary tool in research, it is rarely standardized. To achieve accurate quantitative microscopy data and reproducible results, three levels of standardization must be considered: (1) aspects of the microscope, (2) the sample, and (3) the detector. The accuracy of the data is only as reliable as the imaging system itself, thereby imposing the need for routine standard performance testing. Depending on the task some maintenance procedures should be performed once a month, some before each imaging session, while others conducted annually. This text should be implemented as a resource for researchers to integrate with their own standard operating procedures to ensure the highest quality quantitative microscopy data. Copyright © 2017. Published by Elsevier Ltd.

  16. Reproducibility of Automated Voice Range Profiles, a Systematic Literature Review

    DEFF Research Database (Denmark)

    Printz, Trine; Rosenberg, Tine; Godballe, Christian

    2018-01-01

    literature on test-retest accuracy of the automated voice range profile assessment. Study design: Systematic review. Data sources: PubMed, Scopus, Cochrane Library, ComDisDome, Embase, and CINAHL (EBSCO). Methods: We conducted a systematic literature search of six databases from 1983 to 2016. The following......Objective: Reliable voice range profiles are of great importance when measuring effects and side effects from surgery affecting voice capacity. Automated recording systems are increasingly used, but the reproducibility of results is uncertain. Our objective was to identify and review the existing...... keywords were used: phonetogram, voice range profile, and acoustic voice analysis. Inclusion criteria were automated recording procedure, healthy voices, and no intervention between test and retest. Test-retest values concerning fundamental frequency and voice intensity were reviewed. Results: Of 483...

  17. Enhancing Scientific Foundations to Ensure Reproducibility: A New Paradigm.

    Science.gov (United States)

    Hsieh, Terry; Vaickus, Max H; Remick, Daniel G

    2018-01-01

    Progress in science is dependent on a strong foundation of reliable results. The publish or perish paradigm in research, coupled with an increase in retracted articles from the peer-reviewed literature, is beginning to erode the trust of both the scientific community and the public. The NIH is combating errors by requiring investigators to follow new guidelines addressing scientific premise, experimental design, biological variables, and authentication of reagents. Herein, we discuss how implementation of NIH guidelines will help investigators proactively address pitfalls of experimental design and methods. Careful consideration of the variables contributing to reproducibility helps ensure robust results. The NIH, investigators, and journals must collaborate to ensure that quality science is funded, explored, and published. Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  18. Reproducibility of gallbladder ejection fraction measured by fatty meal cholescintigraphy

    International Nuclear Information System (INIS)

    Al-Muqbel, Kusai M.; Hani, M. N. Hani; Elheis, M. A.; Al-Omari, M. H.

    2010-01-01

    There are conflicting data in the literature regarding the reproducibility of the gallbladder ejection fraction (GBEF) measured by fatty meal cholescintigraphy (CS). We aimed to test the reproducibility of GBEF measured by fatty meal CS. Thirty-five subjects (25 healthy volunteers and 10 patients with chronic abdominal pain) underwent fatty meal CS twice in order to measure GBEF1 and GBEF2. The healthy volunteers underwent a repeat scan within 1-13 months from the first scan. The patients underwent a repeat scan within 1-4 years from the first scan and were not found to have chronic acalculous cholecystitis (CAC). Our standard fatty meal was composed of a 60-g Snickers chocolate bar and 200 ml full-fat yogurt. The mean ± SD values for GBEF1 and GBEF2 were 52±17% and 52±16%, respectively. There was a direct linear correlation between the values of GBEF1 and GBEF2 for the subjects, with a correlation coefficient of 0.509 (p=0.002). Subgroup data analysis of the volunteer group showed that there was significant linear correlation between volunteer values of GBEF1 and GBEF2, with a correlation coefficient of 0.473 (p=0.017). Subgroup data analysis of the non-CAC patient group showed no significant correlation between patient values of GBEF1 and GBEF2, likely due to limited sample size. This study showed that fatty meal CS is a reliable test in gallbladder motility evaluation and that GBEF measured by fatty meal CS is reproducible

  19. Reproducibility of gallbladder ejection fraction measured by fatty meal cholescintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Al-Muqbel, Kusai M.; Hani, M. N. Hani; Elheis, M. A.; Al-Omari, M. H. [School of Medicine, Jordan University of Science and Technology, Irbid (Jordan)

    2010-12-15

    There are conflicting data in the literature regarding the reproducibility of the gallbladder ejection fraction (GBEF) measured by fatty meal cholescintigraphy (CS). We aimed to test the reproducibility of GBEF measured by fatty meal CS. Thirty-five subjects (25 healthy volunteers and 10 patients with chronic abdominal pain) underwent fatty meal CS twice in order to measure GBEF1 and GBEF2. The healthy volunteers underwent a repeat scan within 1-13 months from the first scan. The patients underwent a repeat scan within 1-4 years from the first scan and were not found to have chronic acalculous cholecystitis (CAC). Our standard fatty meal was composed of a 60-g Snickers chocolate bar and 200 ml full-fat yogurt. The mean {+-} SD values for GBEF1 and GBEF2 were 52{+-}17% and 52{+-}16%, respectively. There was a direct linear correlation between the values of GBEF1 and GBEF2 for the subjects, with a correlation coefficient of 0.509 (p=0.002). Subgroup data analysis of the volunteer group showed that there was significant linear correlation between volunteer values of GBEF1 and GBEF2, with a correlation coefficient of 0.473 (p=0.017). Subgroup data analysis of the non-CAC patient group showed no significant correlation between patient values of GBEF1 and GBEF2, likely due to limited sample size. This study showed that fatty meal CS is a reliable test in gallbladder motility evaluation and that GBEF measured by fatty meal CS is reproducible

  20. Size Control of Sessile Microbubbles for Reproducibly Driven Acoustic Streaming

    Science.gov (United States)

    Volk, Andreas; Kähler, Christian J.

    2018-05-01

    Acoustically actuated bubbles are receiving growing interest in microfluidic applications, as they induce a streaming field that can be used for particle sorting and fluid mixing. An essential but often unspoken challenge in such applications is to maintain a constant bubble size to achieve reproducible conditions. We present an automatized system for the size control of a cylindrical bubble that is formed at a blind side pit of a polydimethylsiloxane microchannel. Using a pressure control system, we adapt the protrusion depth of the bubble into the microchannel to a precision of approximately 0.5 μ m on a timescale of seconds. By comparing the streaming field generated by bubbles of width 80 μ m with a protrusion depth between -12 and 60 μ m , we find that the mean velocity of the induced streaming fields varies by more than a factor of 4. We also find a qualitative change of the topology of the streaming field. Both observations confirm the importance of the bubble size control system in order to achieve reproducible and reliable bubble-driven streaming experiments.

  1. Reproducibility of the chamber scarification test

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner

    1996-01-01

    The chamber scarification test is a predictive human skin irritation test developed to rank the irritation potential of products and ingredients meant for repeated use on normal and diseased skin. 12 products or ingredients can be tested simultaneously on the forearm skin of each volunteer....... The test combines with the procedure scratching of the skin at each test site and subsequent closed patch tests with the products, repeated daily for 3 days. The test is performed on groups of human volunteers: a skin irritant substance or products is included in each test as a positive control...... high reproducibility of the test. Further, intra-individual variation in skin reaction to the 2 control products in 26 volunteers, who participated 2x, is shown, which supports the conclusion that the chamber scarification test is a useful short-term human skin irritation test with high reproducibility....

  2. Reproducibility in cyclostratigraphy: initiating an intercomparison project

    Science.gov (United States)

    Sinnesael, Matthias; De Vleeschouwer, David; Zeeden, Christian; Claeys, Philippe

    2017-04-01

    The study of astronomical climate forcing and the application of cyclostratigraphy have experienced a spectacular growth over the last decades. In the field of cyclostratigraphy a broad range in methodological approaches exist. However, comparative study between the different approaches is lacking. Different cases demand different approaches, but with the growing importance of the field, questions arise about reproducibility, uncertainties and standardization of results. The radioisotopic dating community, in particular, has done far-reaching efforts to improve reproducibility and intercomparison of radioisotopic dates and their errors. To satisfy this need in cyclostratigraphy, we initiate a comparable framework for the community. The aims are to investigate and quantify reproducibility of, and uncertainties related to cyclostratigraphic studies and to provide a platform to discuss the merits and pitfalls of different methodologies, and their applicabilities. With this poster, we ask the feedback from the community on how to design this comparative framework in a useful, meaningful and productive manner. In parallel, we would like to discuss how reproducibility should be tested and what uncertainties should stand for in cyclostratigraphy. On the other hand, we intend to trigger interest for a cyclostratigraphic intercomparison project. This intercomparison project would imply the analysis of artificial and genuine geological records by individual researchers. All participants would be free to determine their method of choice. However, a handful of criterions will be required for an outcome to be comparable. The different results would be compared (e.g. during a workshop or a special session), and the lessons learned from the comparison could potentially be reported in a review paper. The aim of an intercomparison project is not to rank the different methods according to their merits, but to get insight into which specific methods are most suitable for which

  3. A how to guide to reproducible research

    OpenAIRE

    Whitaker, Kirstie

    2018-01-01

    This talk will discuss the perceived and actual barriers experienced by researchers attempting to do reproducible research, and give practical guidance on how they can be overcome. It will include suggestions on how to make your code and data available and usable for others (including a strong suggestion to document both clearly so you don't have to reply to lots of email questions from future users). Specifically it will include a brief guide to version control, collaboration and disseminati...

  4. Bad Behavior: Improving Reproducibility in Behavior Testing.

    Science.gov (United States)

    Andrews, Anne M; Cheng, Xinyi; Altieri, Stefanie C; Yang, Hongyan

    2018-01-24

    Systems neuroscience research is increasingly possible through the use of integrated molecular and circuit-level analyses. These studies depend on the use of animal models and, in many cases, molecular and circuit-level analyses. Associated with genetic, pharmacologic, epigenetic, and other types of environmental manipulations. We illustrate typical pitfalls resulting from poor validation of behavior tests. We describe experimental designs and enumerate controls needed to improve reproducibility in investigating and reporting of behavioral phenotypes.

  5. A Framework for Reproducible Latent Fingerprint Enhancements.

    Science.gov (United States)

    Carasso, Alfred S

    2014-01-01

    Photoshop processing of latent fingerprints is the preferred methodology among law enforcement forensic experts, but that appproach is not fully reproducible and may lead to questionable enhancements. Alternative, independent, fully reproducible enhancements, using IDL Histogram Equalization and IDL Adaptive Histogram Equalization, can produce better-defined ridge structures, along with considerable background information. Applying a systematic slow motion smoothing procedure to such IDL enhancements, based on the rapid FFT solution of a Lévy stable fractional diffusion equation, can attenuate background detail while preserving ridge information. The resulting smoothed latent print enhancements are comparable to, but distinct from, forensic Photoshop images suitable for input into automated fingerprint identification systems, (AFIS). In addition, this progressive smoothing procedure can be reexamined by displaying the suite of progressively smoother IDL images. That suite can be stored, providing an audit trail that allows monitoring for possible loss of useful information, in transit to the user-selected optimal image. Such independent and fully reproducible enhancements provide a valuable frame of reference that may be helpful in informing, complementing, and possibly validating the forensic Photoshop methodology.

  6. Reproducibility of 201Tl myocardial imaging

    International Nuclear Information System (INIS)

    McLaughlin, P.R.; Martin, R.P.; Doherty, P.; Daspit, S.; Goris, M.; Haskell, W.; Lewis, S.; Kriss, J.P.; Harrison, D.C.

    1977-01-01

    Seventy-six thallium-201 myocardial perfusion studies were performed on twenty-five patients to assess their reproducibility and the effect of varying the level of exercise on the results of imaging. Each patient had a thallium-201 study at rest. Fourteen patients had studies on two occasions at maximum exercise, and twelve patients had studies both at light and at maximum exercise. Of 70 segments in the 14 patients assessed on each of two maximum exercise tests, 64 (91 percent) were reproducible. Only 53 percent (16/30) of the ischemic defects present at maximum exercise were seen in the light exercise study in the 12 patients assessed at two levels of exercise. Correlation of perfusion defects with arteriographically proven significant coronary stenosis was good for the left anterior descending and right coronary arteries, but not as good for circumflex artery disease. Thallium-201 myocardial imaging at maximum exercise is reproducible within acceptable limits, but careful attention to exercise technique is essential for valid comparative studies

  7. An Introduction To Reliability

    International Nuclear Information System (INIS)

    Park, Kyoung Su

    1993-08-01

    This book introduces reliability with definition of reliability, requirement of reliability, system of life cycle and reliability, reliability and failure rate such as summary, reliability characteristic, chance failure, failure rate which changes over time, failure mode, replacement, reliability in engineering design, reliability test over assumption of failure rate, and drawing of reliability data, prediction of system reliability, conservation of system, failure such as summary and failure relay and analysis of system safety.

  8. Standing Together for Reproducibility in Large-Scale Computing: Report on reproducibility@XSEDE

    OpenAIRE

    James, Doug; Wilkins-Diehr, Nancy; Stodden, Victoria; Colbry, Dirk; Rosales, Carlos; Fahey, Mark; Shi, Justin; Silva, Rafael F.; Lee, Kyo; Roskies, Ralph; Loewe, Laurence; Lindsey, Susan; Kooper, Rob; Barba, Lorena; Bailey, David

    2014-01-01

    This is the final report on reproducibility@xsede, a one-day workshop held in conjunction with XSEDE14, the annual conference of the Extreme Science and Engineering Discovery Environment (XSEDE). The workshop's discussion-oriented agenda focused on reproducibility in large-scale computational research. Two important themes capture the spirit of the workshop submissions and discussions: (1) organizational stakeholders, especially supercomputer centers, are in a unique position to promote, enab...

  9. Comparison of reliability of lateral cephalogram and computed ...

    African Journals Online (AJOL)

    2014-05-07

    May 7, 2014 ... measurements acquired from both the modalities are reliable and reproducible, but .... paint on all the slice of the image stack in the axial plane of ..... between body mass index, age and upper airway measurements in snorers.

  10. Convergence of macrostates under reproducible processes

    International Nuclear Information System (INIS)

    Rau, Jochen

    2010-01-01

    I show that whenever a system undergoes a reproducible macroscopic process the mutual distinguishability of macrostates, as measured by their relative entropy, diminishes. This extends the second law which regards only ordinary entropies, and hence only the distinguishability between macrostates and one specific reference state (equidistribution). The new result holds regardless of whether the process is linear or nonlinear. Its proof hinges on the monotonicity of quantum relative entropy under arbitrary coarse grainings, even those that cannot be represented by trace-preserving completely positive maps.

  11. Open and reproducible global land use classification

    Science.gov (United States)

    Nüst, Daniel; Václavík, Tomáš; Pross, Benjamin

    2015-04-01

    Researchers led by the Helmholtz Centre for Environmental research (UFZ) developed a new world map of land use systems based on over 30 diverse indicators (http://geoportal.glues.geo.tu-dresden.de/stories/landsystemarchetypes.html) of land use intensity, climate and environmental and socioeconomic factors. They identified twelve land system archetypes (LSA) using a data-driven classification algorithm (self-organizing maps) to assess global impacts of land use on the environment, and found unexpected similarities across global regions. We present how the algorithm behind this analysis can be published as an executable web process using 52°North WPS4R (https://wiki.52north.org/bin/view/Geostatistics/WPS4R) within the GLUES project (http://modul-a.nachhaltiges-landmanagement.de/en/scientific-coordination-glues/). WPS4R is an open source collaboration platform for researchers, analysts and software developers to publish R scripts (http://www.r-project.org/) as a geo-enabled OGC Web Processing Service (WPS) process. The interoperable interface to call the geoprocess allows both reproducibility of the analysis and integration of user data without knowledge about web services or classification algorithms. The open platform allows everybody to replicate the analysis in their own environments. The LSA WPS process has several input parameters, which can be changed via a simple web interface. The input parameters are used to configure both the WPS environment and the LSA algorithm itself. The encapsulation as a web process allows integration of non-public datasets, while at the same time the publication requires a well-defined documentation of the analysis. We demonstrate this platform specifically to domain scientists and show how reproducibility and open source publication of analyses can be enhanced. We also discuss future extensions of the reproducible land use classification, such as the possibility for users to enter their own areas of interest to the system and

  12. Reproducibility in Research: Systems, Infrastructure, Culture

    Directory of Open Access Journals (Sweden)

    Tom Crick

    2017-11-01

    Full Text Available The reproduction and replication of research results has become a major issue for a number of scientific disciplines. In computer science and related computational disciplines such as systems biology, the challenges closely revolve around the ability to implement (and exploit novel algorithms and models. Taking a new approach from the literature and applying it to a new codebase frequently requires local knowledge missing from the published manuscripts and transient project websites. Alongside this issue, benchmarking, and the lack of open, transparent and fair benchmark sets present another barrier to the verification and validation of claimed results. In this paper, we outline several recommendations to address these issues, driven by specific examples from a range of scientific domains. Based on these recommendations, we propose a high-level prototype open automated platform for scientific software development which effectively abstracts specific dependencies from the individual researcher and their workstation, allowing easy sharing and reproduction of results. This new e-infrastructure for reproducible computational science offers the potential to incentivise a culture change and drive the adoption of new techniques to improve the quality and efficiency – and thus reproducibility – of scientific exploration.

  13. Reproducibility assessment of brain responses to visual food stimuli in adults with overweight and obesity.

    Science.gov (United States)

    Drew Sayer, R; Tamer, Gregory G; Chen, Ningning; Tregellas, Jason R; Cornier, Marc-Andre; Kareken, David A; Talavage, Thomas M; McCrory, Megan A; Campbell, Wayne W

    2016-10-01

    The brain's reward system influences ingestive behavior and subsequently obesity risk. Functional magnetic resonance imaging (fMRI) is a common method for investigating brain reward function. This study sought to assess the reproducibility of fasting-state brain responses to visual food stimuli using BOLD fMRI. A priori brain regions of interest included bilateral insula, amygdala, orbitofrontal cortex, caudate, and putamen. Fasting-state fMRI and appetite assessments were completed by 28 women (n = 16) and men (n = 12) with overweight or obesity on 2 days. Reproducibility was assessed by comparing mean fasting-state brain responses and measuring test-retest reliability of these responses on the two testing days. Mean fasting-state brain responses on day 2 were reduced compared with day 1 in the left insula and right amygdala, but mean day 1 and day 2 responses were not different in the other regions of interest. With the exception of the left orbitofrontal cortex response (fair reliability), test-retest reliabilities of brain responses were poor or unreliable. fMRI-measured responses to visual food cues in adults with overweight or obesity show relatively good mean-level reproducibility but considerable within-subject variability. Poor test-retest reliability reduces the likelihood of observing true correlations and increases the necessary sample sizes for studies. © 2016 The Obesity Society.

  14. Frontiers of reliability

    CERN Document Server

    Basu, Asit P; Basu, Sujit K

    1998-01-01

    This volume presents recent results in reliability theory by leading experts in the world. It will prove valuable for researchers, and users of reliability theory. It consists of refereed invited papers on a broad spectrum of topics in reliability. The subjects covered include Bayesian reliability, Bayesian reliability modeling, confounding in a series system, DF tests, Edgeworth approximation to reliability, estimation under random censoring, fault tree reduction for reliability, inference about changes in hazard rates, information theory and reliability, mixture experiment, mixture of Weibul

  15. Reproducible gene targeting in recalcitrant Escherichia coli isolates

    Directory of Open Access Journals (Sweden)

    De Greve Henri

    2011-06-01

    Full Text Available Abstract Background A number of allele replacement methods can be used to mutate bacterial genes. For instance, the Red recombinase system of phage Lambda has been used very efficiently to inactivate chromosomal genes in E. coli K-12, through recombination between regions of homology. However, this method does not work reproducibly in some clinical E. coli isolates. Findings The procedure was modified by using longer homologous regions (85 bp and 500-600 bp, to inactivate genes in the uropathogenic E. coli strain UTI89. An lrhA regulator mutant, and deletions of the lac operon as well as the complete type 1 fimbrial gene cluster, were obtained reproducibly. The modified method is also functional in other recalcitrant E. coli, like the avian pathogenic E. coli strain APEC1. The lrhA regulator and lac operon deletion mutants of APEC1 were successfully constructed in the same way as the UTI89 mutants. In other avian pathogenic E. coli strains (APEC3E, APEC11A and APEC16A it was very difficult or impossible to construct these mutants, with the original Red recombinase-based method, with a Red recombinase-based method using longer (85 bp homologous regions or with our modified protocol, using 500 - 600 bp homologous regions. Conclusions The method using 500-600 bp homologous regions can be used reliably in some clinical isolates, to delete single genes or entire operons by homologous recombination. However, it does not invariably show a greater efficiency in obtaining mutants, when compared to the original Red-mediated gene targeting method or to the gene targeting method with 85 bp homologous regions. Therefore the length of the homology regions is not the only limiting factor for the construction of mutants in these recalcitrant strains.

  16. Reproducibility of the results in nondestructive testing

    International Nuclear Information System (INIS)

    Launay, J.P.; Chalaye, H.; Thomas, A.

    1980-10-01

    Pressure vessels must comply with very severe safety criteria. In order to ensure that the required quality is attained, non destructive tests are used and these have to be highly reliable: magnetoscopy and liquid penetration for surface examinations, radiography and ultrasonics for voluminal examinations. In the case of ultrasonic examinations, a study of parameters has been made and a statistical analysis of the results has made it possible to calculate the dispersion due to the testing equipment [fr

  17. PSYCHOLOGY. Estimating the reproducibility of psychological science.

    Science.gov (United States)

    2015-08-28

    Reproducibility is a defining feature of science, but the extent to which it characterizes current research is unknown. We conducted replications of 100 experimental and correlational studies published in three psychology journals using high-powered designs and original materials when available. Replication effects were half the magnitude of original effects, representing a substantial decline. Ninety-seven percent of original studies had statistically significant results. Thirty-six percent of replications had statistically significant results; 47% of original effect sizes were in the 95% confidence interval of the replication effect size; 39% of effects were subjectively rated to have replicated the original result; and if no bias in original results is assumed, combining original and replication results left 68% with statistically significant effects. Correlational tests suggest that replication success was better predicted by the strength of original evidence than by characteristics of the original and replication teams. Copyright © 2015, American Association for the Advancement of Science.

  18. Reproducibility of range of motion and muscle strength measurements in patients with hip osteoarthritis – an interrater study

    DEFF Research Database (Denmark)

    Poulsen, Erik; Christensen, Henrik Wulff; Penny, Jeannette Østergaard

    2012-01-01

    ABSTRACT: BACKGROUND: Assessment of range of motion (ROM) and muscle strength is fundamental in the clinical diagnosis of hip osteoarthritis (OA) but reproducibility of these measurements has mostly involved clinicians from secondary care and has rarely reported agreement parameters. Therefore......, the primary objective of the study was to determine the inter-rater reproducibility of ROM and muscle strength measurements. Furthermore, the reliability of the overall assessment of clinical hip OA was evaluated. Reporting is in accordance with proposed guidelines for the reporting of reliability...... differentiate between hips with or without osteoarthritis....

  19. Reproducibility of MR-based Attenuation Maps in PET/MRI and the Impact on PET Quantification in Lung Cancer

    DEFF Research Database (Denmark)

    Olin, Anders; Ladefoged, Claes N; Langer, Natasha H

    2018-01-01

    AIM: Quantitative positron emission tomography/magnetic resonance imaging (PET/MRI) is dependent upon reliable and reproducible MR-based attenuation correction (MR-AC). In this study we evaluated the quality of current vendor-provided thoracic MR-AC maps, and further investigated...... affecting the reproducibility of PET/MRI. This, in combination with other well-known sources of error associated with PET/MRI examinations, leads to inconsistent SUV measurements in serial studies and follow-up scenarios, which may affect the reliability of therapy response assessment. A thorough visual...

  20. Repeatability and reproducibility of Population Viability Analysis (PVA and the implications for threatened species management

    Directory of Open Access Journals (Sweden)

    Clare Morrison

    2016-08-01

    Full Text Available Conservation triage focuses on prioritizing species, populations or habitats based on urgency, biodiversity benefits, recovery potential as well as cost. Population Viability Analysis (PVA is frequently used in population focused conservation prioritizations. The critical nature of many of these management decisions requires that PVA models are repeatable and reproducible to reliably rank species and/or populations quantitatively. This paper assessed the repeatability and reproducibility of a subset of previously published PVA models. We attempted to rerun baseline models from 90 publicly available PVA studies published between 2000-2012 using the two most common PVA modelling software programs, VORTEX and RAMAS-GIS. Forty percent (n = 36 failed, 50% (45 were both repeatable and reproducible, and 10% (9 had missing baseline models. Repeatability was not linked to taxa, IUCN category, PVA program version used, year published or the quality of publication outlet, suggesting that the problem is systemic within the discipline. Complete and systematic presentation of PVA parameters and results are needed to ensure that the scientific input into conservation planning is both robust and reliable, thereby increasing the chances of making decisions that are both beneficial and defensible. The implications for conservation triage may be far reaching if population viability models cannot be reproduced with confidence, thus undermining their intended value.

  1. System Reliability Engineering

    International Nuclear Information System (INIS)

    Lim, Tae Jin

    2005-02-01

    This book tells of reliability engineering, which includes quality and reliability, reliability data, importance of reliability engineering, reliability and measure, the poisson process like goodness of fit test and the poisson arrival model, reliability estimation like exponential distribution, reliability of systems, availability, preventive maintenance such as replacement policies, minimal repair policy, shock models, spares, group maintenance and periodic inspection, analysis of common cause failure, and analysis model of repair effect.

  2. Reproducibility of morphometric X-ray absorptiometry

    International Nuclear Information System (INIS)

    Culton, N.; Pocock, N.

    1999-01-01

    Full text: Morphometric X-ray absorptiometry (MXA) using DXA is potentially a useful clinical tool which may provide additional vertebral fracture information with low radiation exposure. While morphometric analysis is semi-automated, operator intervention is crucial for the accurate positioning of the six data points quantifying the vertebral heights at the anterior, middle and posterior positions. Our study evaluated intra-operator reproducibility of MXA in an elderly patient population and assessed the effect of training and experience on vertebral height precision. Ten patients, with a mean lumbar T score of - 2.07, were studied. Images were processed by a trained operator who had initially only limited morphometric experience. The analysis of the data files were repeated at 2 and 6 weeks, during which time the operator had obtained further experience and training. The intra-operator precision of vertebral height measurements was calculated using the three separate combinations of paired analyses, and expressed as the coefficient of variation. This study confirms the importance of adequate training and attention to detail in MXA analysis. The data indicate that the precision of MXA is adequate for its use in the diagnosis of vertebral fractures, based on a 20% deformity criteria. Use of MXA for monitoring would require approximately an 8% change in vertebral heights to achieve statistical significance

  3. Reproducibility of neuroimaging analyses across operating systems.

    Science.gov (United States)

    Glatard, Tristan; Lewis, Lindsay B; Ferreira da Silva, Rafael; Adalat, Reza; Beck, Natacha; Lepage, Claude; Rioux, Pierre; Rousseau, Marc-Etienne; Sherif, Tarek; Deelman, Ewa; Khalili-Mahani, Najmeh; Evans, Alan C

    2015-01-01

    Neuroimaging pipelines are known to generate different results depending on the computing platform where they are compiled and executed. We quantify these differences for brain tissue classification, fMRI analysis, and cortical thickness (CT) extraction, using three of the main neuroimaging packages (FSL, Freesurfer and CIVET) and different versions of GNU/Linux. We also identify some causes of these differences using library and system call interception. We find that these packages use mathematical functions based on single-precision floating-point arithmetic whose implementations in operating systems continue to evolve. While these differences have little or no impact on simple analysis pipelines such as brain extraction and cortical tissue classification, their accumulation creates important differences in longer pipelines such as subcortical tissue classification, fMRI analysis, and cortical thickness extraction. With FSL, most Dice coefficients between subcortical classifications obtained on different operating systems remain above 0.9, but values as low as 0.59 are observed. Independent component analyses (ICA) of fMRI data differ between operating systems in one third of the tested subjects, due to differences in motion correction. With Freesurfer and CIVET, in some brain regions we find an effect of build or operating system on cortical thickness. A first step to correct these reproducibility issues would be to use more precise representations of floating-point numbers in the critical sections of the pipelines. The numerical stability of pipelines should also be reviewed.

  4. Modeling reproducibility of porescale multiphase flow experiments

    Science.gov (United States)

    Ling, B.; Tartakovsky, A. M.; Bao, J.; Oostrom, M.; Battiato, I.

    2017-12-01

    Multi-phase flow in porous media is widely encountered in geological systems. Understanding immiscible fluid displacement is crucial for processes including, but not limited to, CO2 sequestration, non-aqueous phase liquid contamination and oil recovery. Microfluidic devices and porescale numerical models are commonly used to study multiphase flow in biological, geological, and engineered porous materials. In this work, we perform a set of drainage and imbibition experiments in six identical microfluidic cells to study the reproducibility of multiphase flow experiments. We observe significant variations in the experimental results, which are smaller during the drainage stage and larger during the imbibition stage. We demonstrate that these variations are due to sub-porescale geometry differences in microcells (because of manufacturing defects) and variations in the boundary condition (i.e.,fluctuations in the injection rate inherent to syringe pumps). Computational simulations are conducted using commercial software STAR-CCM+, both with constant and randomly varying injection rate. Stochastic simulations are able to capture variability in the experiments associated with the varying pump injection rate.

  5. Environment and industrial economy: Challenge of reproducibility

    International Nuclear Information System (INIS)

    Rullani, E.

    1992-01-01

    Historically and methodologically counterposed until now, the environmentalist and the economic approach to environmental problems need to be integrated in a new approach that considers, from one side, the relevance of the ecological equilibria for the economic systems and, from the other side, the economic dimension (in terms of investments and transformations in the production system) of any attempt to achieve a better environment. In order to achieve this integration, both approaches are compelled to give up some cultural habits that have characterized them, and have contributed to over-emphasize the opposition between them. The article shows that both approaches can converge into a new one, in which environment is no longer only an holistic, not bargainable, natural external limit to human activity (as in the environmentalist approach), nor simply a scarce and exhaustible resource (as economics tends to consider it); environment should instead become part of the reproducibility sphere, or, in other words, it must be regarded as part of the output that the economic system provides. This new approach, due to scientific and technological advances, is made possible for an increasing class of environmental problems. In order to do this, an evolution is required, that could be able to convert environmental goals into investment and technological innovation goals, and communicate to the firms the value society assigns to environmental resources. This value, the author suggests, should correspond to the reproduction cost. Various examples of this new approach are analyzed and discussed

  6. Liquid scintigraphic gastric emptying - is it reproducible?

    International Nuclear Information System (INIS)

    Cooper, R.G.; Shuter, B.; Leach, M.; Roach, P.J.

    1999-01-01

    Full text: Radioisotope gastric emptying (GE) studies have been used as a non-invasive technique for motility assessment for many years. In a recent study investigating the correlation of mesenteric vascular changes with GE, six subjects had a repeat study 2-4 months later. Repeat studies were required due to minor technical problems (5 subjects) and a very slow GE (I subject) on the original study. Subjects drank 275 ml of 'Ensure Plus' mixed with 8 MBq 67 Ga-DTPA and were imaged for 2 h while lying supine. GE time-activity curves for each subject were generated and time to half emptying (T l/2 ) calculated. Five of the six subjects had more rapid GE on the second study. Three of the subjects had T l/2 values on their second study which were within ± 15 min of their original T l/2 . The other three subjects had T l/2 values on their second study which were 36 min, 55 min and 280 min (subject K.H.) less than their original T l/2 . Statistical analysis (t-test) was performed on paired T l/2 values. The average T l/2 value was greater in the first study than in the second (149 ± 121 and 86 ± 18 min respectively), although the difference was not statistically significant (P ∼ 0.1). Subjects' anxiety levels were not quantitated during the GE study; however, several major equipment faults occurred during the original study of subject K.H., who became visibly stressed. These results suggest that the reproducibility of GE studies may be influenced by psychological factors

  7. Is my network module preserved and reproducible?

    Directory of Open Access Journals (Sweden)

    Peter Langfelder

    2011-01-01

    Full Text Available In many applications, one is interested in determining which of the properties of a network module change across conditions. For example, to validate the existence of a module, it is desirable to show that it is reproducible (or preserved in an independent test network. Here we study several types of network preservation statistics that do not require a module assignment in the test network. We distinguish network preservation statistics by the type of the underlying network. Some preservation statistics are defined for a general network (defined by an adjacency matrix while others are only defined for a correlation network (constructed on the basis of pairwise correlations between numeric variables. Our applications show that the correlation structure facilitates the definition of particularly powerful module preservation statistics. We illustrate that evaluating module preservation is in general different from evaluating cluster preservation. We find that it is advantageous to aggregate multiple preservation statistics into summary preservation statistics. We illustrate the use of these methods in six gene co-expression network applications including 1 preservation of cholesterol biosynthesis pathway in mouse tissues, 2 comparison of human and chimpanzee brain networks, 3 preservation of selected KEGG pathways between human and chimpanzee brain networks, 4 sex differences in human cortical networks, 5 sex differences in mouse liver networks. While we find no evidence for sex specific modules in human cortical networks, we find that several human cortical modules are less preserved in chimpanzees. In particular, apoptosis genes are differentially co-expressed between humans and chimpanzees. Our simulation studies and applications show that module preservation statistics are useful for studying differences between the modular structure of networks. Data, R software and accompanying tutorials can be downloaded from the following webpage: http

  8. AMSAA Reliability Growth Guide

    National Research Council Canada - National Science Library

    Broemm, William

    2000-01-01

    ... has developed reliability growth methodology for all phases of the process, from planning to tracking to projection. The report presents this methodology and associated reliability growth concepts.

  9. Precision and reproducibility in AMS radiocarbon measurements.

    Energy Technology Data Exchange (ETDEWEB)

    Hotchkis, M A; Fink, D; Hua, Q; Jacobsen, G E; Lawson, E M; Smith, A M; Tuniz, C [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1997-12-31

    Accelerator Mass Spectrometry (AMS) is a technique by which rare radioisotopes such as {sup 14}C can be measured at environmental levels with high efficiency. Instead of detecting radioactivity, which is very weak for long-lived environmental radioisotopes, atoms are counted directly. The sample is placed in an ion source, from which a negative ion beam of the atoms of interest is extracted, mass analysed, and injected into a tandem accelerator. After stripping to positive charge states in the accelerator HV terminal, the ions are further accelerated, analysed with magnetic and electrostatic devices and counted in a detector. An isotopic ratio is derived from the number of radioisotope atoms counted in a given time and the beam current of a stable isotope of the same element, measured after the accelerator. For radiocarbon, {sup 14}C/{sup 13}C ratios are usually measured, and the ratio of an unknown sample is compared to that of a standard. The achievable precision for such ratio measurements is limited primarily by {sup 14}C counting statistics and also by a variety of factors related to accelerator and ion source stability. At the ANTARES AMS facility at Lucas Heights Research Laboratories we are currently able to measure {sup 14}C with 0.5% precision. In the two years since becoming operational, more than 1000 {sup 14}C samples have been measured. Recent improvements in precision for {sup 14}C have been achieved with the commissioning of a 59 sample ion source. The measurement system, from sample changing to data acquisition, is under common computer control. These developments have allowed a new regime of automated multi-sample processing which has impacted both on the system throughput and the measurement precision. We have developed data evaluation methods at ANTARES which cross-check the self-consistency of the statistical analysis of our data. Rigorous data evaluation is invaluable in assessing the true reproducibility of the measurement system and aids in

  10. Precision and reproducibility in AMS radiocarbon measurements.

    Energy Technology Data Exchange (ETDEWEB)

    Hotchkis, M.A.; Fink, D.; Hua, Q.; Jacobsen, G.E.; Lawson, E. M.; Smith, A.M.; Tuniz, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Accelerator Mass Spectrometry (AMS) is a technique by which rare radioisotopes such as {sup 14}C can be measured at environmental levels with high efficiency. Instead of detecting radioactivity, which is very weak for long-lived environmental radioisotopes, atoms are counted directly. The sample is placed in an ion source, from which a negative ion beam of the atoms of interest is extracted, mass analysed, and injected into a tandem accelerator. After stripping to positive charge states in the accelerator HV terminal, the ions are further accelerated, analysed with magnetic and electrostatic devices and counted in a detector. An isotopic ratio is derived from the number of radioisotope atoms counted in a given time and the beam current of a stable isotope of the same element, measured after the accelerator. For radiocarbon, {sup 14}C/{sup 13}C ratios are usually measured, and the ratio of an unknown sample is compared to that of a standard. The achievable precision for such ratio measurements is limited primarily by {sup 14}C counting statistics and also by a variety of factors related to accelerator and ion source stability. At the ANTARES AMS facility at Lucas Heights Research Laboratories we are currently able to measure {sup 14}C with 0.5% precision. In the two years since becoming operational, more than 1000 {sup 14}C samples have been measured. Recent improvements in precision for {sup 14}C have been achieved with the commissioning of a 59 sample ion source. The measurement system, from sample changing to data acquisition, is under common computer control. These developments have allowed a new regime of automated multi-sample processing which has impacted both on the system throughput and the measurement precision. We have developed data evaluation methods at ANTARES which cross-check the self-consistency of the statistical analysis of our data. Rigorous data evaluation is invaluable in assessing the true reproducibility of the measurement system and aids in

  11. Handgrip force steadiness in young and older adults: a reproducibility study.

    Science.gov (United States)

    Blomkvist, Andreas W; Eika, Fredrik; de Bruin, Eling D; Andersen, Stig; Jorgensen, Martin

    2018-04-02

    Force steadiness is a quantitative measure of the ability to control muscle tonus. It is an independent predictor of functional performance and has shown to correlate well with different degrees of motor impairment following stroke. Despite being clinically relevant, few studies have assessed the validity of measuring force steadiness. The aim of this study was to explore the reproducibility of handgrip force steadiness, and to assess age difference in steadiness. Intrarater reproducibility (the degree to which a rating gives consistent result on separate occasions) was investigated in a test-retest design with seven days between sessions. Ten young and thirty older adults were recruited and handgrip steadiness was tested at 5%, 10% and 25% of maximum voluntary contraction (MVC) using Nintendo Wii Balance Board (WBB). Coefficients of variation were calculated from the mean force produced (CVM) and the target force (CVT). Area between the force curve and the target force line (Area) was also calculated. For the older adults we explored reliability using intraclass correlation coefficient (ICC) and agreement using standard error of measurement (SEM), limits of agreement (LOA) and smallest real difference (SRD). A systematic improvement in handgrip steadiness was found between sessions for all measures (CVM, CVT, Area). CVM and CVT at 5% of MVC showed good to high reliability, while Area had poor reliability for all percentages of MVC. Averaged ICC for CVM, CVT and Area was 0.815, 0.806 and 0.464, respectively. Averaged ICC on 5%, 10%, and 25% of MVC was 0.751, 0.667 and 0.668, respectively. Measures of agreement showed similar trends with better results for CVM and CVT than for Area. Young adults had better handgrip steadiness than older adults across all measures. The CVM and CVT measures demonstrated good reproducibility at lower percentages of MVC using the WBB, and could become relevant measures in the clinical setting. The Area measure had poor reproducibility

  12. Intra- and inter-observer reproducibility and generalizability of first trimester uterine artery pulsatility index by transabdominal and transvaginal ultrasound

    NARCIS (Netherlands)

    Marchi, Laura; Zwertbroek, Eva; Snelder, Judith; Kloosterman, Maaike; Bilardo, Caterina Maddalena

    2016-01-01

    Objectives The primary aim of the study was to assess intra-observer and inter-observer reproducibility and generalizability (general reliability) of first trimester Doppler measurements of uterine arteries (UtA) performed both transabdominally (TA) and transvaginally (TV). Secondary aims were to

  13. A reliability simulation language for reliability analysis

    International Nuclear Information System (INIS)

    Deans, N.D.; Miller, A.J.; Mann, D.P.

    1986-01-01

    The results of work being undertaken to develop a Reliability Description Language (RDL) which will enable reliability analysts to describe complex reliability problems in a simple, clear and unambiguous way are described. Component and system features can be stated in a formal manner and subsequently used, along with control statements to form a structured program. The program can be compiled and executed on a general-purpose computer or special-purpose simulator. (DG)

  14. Guidelines for Reproducibly Building and Simulating Systems Biology Models.

    Science.gov (United States)

    Medley, J Kyle; Goldberg, Arthur P; Karr, Jonathan R

    2016-10-01

    Reproducibility is the cornerstone of the scientific method. However, currently, many systems biology models cannot easily be reproduced. This paper presents methods that address this problem. We analyzed the recent Mycoplasma genitalium whole-cell (WC) model to determine the requirements for reproducible modeling. We determined that reproducible modeling requires both repeatable model building and repeatable simulation. New standards and simulation software tools are needed to enhance and verify the reproducibility of modeling. New standards are needed to explicitly document every data source and assumption, and new deterministic parallel simulation tools are needed to quickly simulate large, complex models. We anticipate that these new standards and software will enable researchers to reproducibly build and simulate more complex models, including WC models.

  15. Silver nanowires for highly reproducible cantilever based AFM-TERS microscopy: towards a universal TERS probe.

    Science.gov (United States)

    Walke, Peter; Fujita, Yasuhiko; Peeters, Wannes; Toyouchi, Shuichi; Frederickx, Wout; De Feyter, Steven; Uji-I, Hiroshi

    2018-04-26

    Tip-enhanced Raman scattering (TERS) microscopy is a unique analytical tool to provide complementary chemical and topographic information of surfaces with nanometric resolution. However, difficulties in reliably producing the necessary metallized scanning probe tips has limited its widespread utilisation, particularly in the case of cantilever-based atomic force microscopy. Attempts to alleviate tip related issues using colloidal or bottom-up engineered tips have so far not reported consistent probes for both Raman and topographic imaging. Here we demonstrate the reproducible fabrication of cantilever-based high-performance TERS probes for both topographic and Raman measurements, based on an approach that utilises noble metal nanowires as the active TERS probe. The tips show 10 times higher TERS contrasts than the most typically used electrochemically-etched tips, and show a reproducibility for TERS greater than 90%, far greater than found with standard methods. We show that TERS can be performed in tapping as well as contact AFM mode, with optical resolutions around or below 15 nm, and with a maximum resolution achieved in tapping-mode of 6 nm. Our work illustrates that superior TERS probes can be produced in a fast and cost-effective manner using simple wet-chemistry methods, leading to reliable and reproducible high-resolution and high-sensitivity TERS, and thus renders the technique applicable for a broad community.

  16. Fixed-flexion radiography of the knee provides reproducible joint space width measurements in osteoarthritis

    International Nuclear Information System (INIS)

    Kothari, Manish; Sieffert, Martine; Block, Jon E.; Peterfy, Charles G.; Guermazi, Ali; Ingersleben, Gabriele von; Miaux, Yves; Stevens, Randall

    2004-01-01

    The validity of a non-fluoroscopic fixed-flexion radiographic acquisition and analysis protocol for measurement of joint space width (JSW) in knee osteoarthritis is determined. A cross-sectional study of 165 patients with documented knee osteoarthritis participating in a multicenter, prospective study of chondroprotective agents was performed. All patients had posteroanterior, weight-bearing, fixed-flexion radiography with 10 caudal beam angulation. A specially designed frame (SynaFlexer) was used to standardize the positioning. Minimum medial and lateral JSW were measured manually and twice by an automated analysis system to determine inter-technique and intra-reader concordance and reliability. A random subsample of 30 patients had repeat knee radiographs 2 weeks apart to estimate short-term reproducibility using automated analysis. Concordance between manual and automated medial JSW measurements was high (ICC=0.90); lateral compartment measurements showed somewhat less concordance (ICC=0.72). There was excellent concordance between repeated automated JSW measurements performed 6 months apart for the medial (ICC=0.94) and lateral (ICC=0.86) compartments. Short-term reproducibility for the subsample of 30 cases with repeat acquisitions demonstrated an average SD of 0.14 mm for medial JSW (CV=4.3%) and 0.23 mm for lateral JSW (CV=4.0%). Fixed-flexion radiography of the knee using a positioning device provides consistent, reliable and reproducible measurement of minimum JSW in knee osteoarthritis without the need for concurrent fluoroscopic guidance. (orig.)

  17. Development of a Consistent and Reproducible Porcine Scald Burn Model

    Science.gov (United States)

    Kempf, Margit; Kimble, Roy; Cuttle, Leila

    2016-01-01

    There are very few porcine burn models that replicate scald injuries similar to those encountered by children. We have developed a robust porcine burn model capable of creating reproducible scald burns for a wide range of burn conditions. The study was conducted with juvenile Large White pigs, creating replicates of burn combinations; 50°C for 1, 2, 5 and 10 minutes and 60°C, 70°C, 80°C and 90°C for 5 seconds. Visual wound examination, biopsies and Laser Doppler Imaging were performed at 1, 24 hours and at 3 and 7 days post-burn. A consistent water temperature was maintained within the scald device for long durations (49.8 ± 0.1°C when set at 50°C). The macroscopic and histologic appearance was consistent between replicates of burn conditions. For 50°C water, 10 minute duration burns showed significantly deeper tissue injury than all shorter durations at 24 hours post-burn (p ≤ 0.0001), with damage seen to increase until day 3 post-burn. For 5 second duration burns, by day 7 post-burn the 80°C and 90°C scalds had damage detected significantly deeper in the tissue than the 70°C scalds (p ≤ 0.001). A reliable and safe model of porcine scald burn injury has been successfully developed. The novel apparatus with continually refreshed water improves consistency of scald creation for long exposure times. This model allows the pathophysiology of scald burn wound creation and progression to be examined. PMID:27612153

  18. Modelling soil erosion at European scale: towards harmonization and reproducibility

    Science.gov (United States)

    Bosco, C.; de Rigo, D.; Dewitte, O.; Poesen, J.; Panagos, P.

    2015-02-01

    Soil erosion by water is one of the most widespread forms of soil degradation. The loss of soil as a result of erosion can lead to decline in organic matter and nutrient contents, breakdown of soil structure and reduction of the water-holding capacity. Measuring soil loss across the whole landscape is impractical and thus research is needed to improve methods of estimating soil erosion with computational modelling, upon which integrated assessment and mitigation strategies may be based. Despite the efforts, the prediction value of existing models is still limited, especially at regional and continental scale, because a systematic knowledge of local climatological and soil parameters is often unavailable. A new approach for modelling soil erosion at regional scale is here proposed. It is based on the joint use of low-data-demanding models and innovative techniques for better estimating model inputs. The proposed modelling architecture has at its basis the semantic array programming paradigm and a strong effort towards computational reproducibility. An extended version of the Revised Universal Soil Loss Equation (RUSLE) has been implemented merging different empirical rainfall-erosivity equations within a climatic ensemble model and adding a new factor for a better consideration of soil stoniness within the model. Pan-European soil erosion rates by water have been estimated through the use of publicly available data sets and locally reliable empirical relationships. The accuracy of the results is corroborated by a visual plausibility check (63% of a random sample of grid cells are accurate, 83% at least moderately accurate, bootstrap p ≤ 0.05). A comparison with country-level statistics of pre-existing European soil erosion maps is also provided.

  19. Participant Nonnaiveté and the reproducibility of cognitive psychology.

    Science.gov (United States)

    Zwaan, Rolf A; Pecher, Diane; Paolacci, Gabriele; Bouwmeester, Samantha; Verkoeijen, Peter; Dijkstra, Katinka; Zeelenberg, René

    2017-07-25

    Many argue that there is a reproducibility crisis in psychology. We investigated nine well-known effects from the cognitive psychology literature-three each from the domains of perception/action, memory, and language, respectively-and found that they are highly reproducible. Not only can they be reproduced in online environments, but they also can be reproduced with nonnaïve participants with no reduction of effect size. Apparently, some cognitive tasks are so constraining that they encapsulate behavior from external influences, such as testing situation and prior recent experience with the experiment to yield highly robust effects.

  20. The reproducibility of 31-phosphorus MRS measures of muscle energetics at 3 Tesla in trained men.

    Directory of Open Access Journals (Sweden)

    Lindsay M Edwards

    Full Text Available OBJECTIVE: Magnetic resonance spectroscopy (MRS provides an exceptional opportunity for the study of in vivo metabolism. MRS is widely used to measure phosphorus metabolites in trained muscle, although there are no published data regarding its reproducibility in this specialized cohort. Thus, the aim of this study was to assess the reproducibility of (31P-MRS in trained skeletal muscle. METHODS: We recruited fifteen trained men (VO(2peak = 4.7±0.8 L min(-1/58±8 mL kg(-1 min(-1 and performed duplicate MR experiments during plantar flexion exercise, three weeks apart. RESULTS: Measures of resting phosphorus metabolites were reproducible, with 1.7 mM the smallest detectable difference in phosphocreatine (PCr. Measures of metabolites during exercise were less reliable: exercising PCr had a coefficient of variation (CV of 27% during exercise, compared with 8% at rest. Estimates of mitochondrial function were variable, but experimentally useful. The CV of PCr(1/2t was 40%, yet much of this variance was inter-subject such that differences of <20% were detectable with n = 15, given a significance threshold of p<0.05. CONCLUSIONS: 31-phosphorus MRS provides reproducible and experimentally useful measures of phosphorus metabolites and mitochondrial function in trained human skeletal muscle.

  1. Reproducibility of myelin content-based human habenula segmentation at 3 Tesla.

    Science.gov (United States)

    Kim, Joo-Won; Naidich, Thomas P; Joseph, Joshmi; Nair, Divya; Glasser, Matthew F; O'halloran, Rafael; Doucet, Gaelle E; Lee, Won Hee; Krinsky, Hannah; Paulino, Alejandro; Glahn, David C; Anticevic, Alan; Frangou, Sophia; Xu, Junqian

    2018-03-26

    In vivo morphological study of the human habenula, a pair of small epithalamic nuclei adjacent to the dorsomedial thalamus, has recently gained significant interest for its role in reward and aversion processing. However, segmenting the habenula from in vivo magnetic resonance imaging (MRI) is challenging due to the habenula's small size and low anatomical contrast. Although manual and semi-automated habenula segmentation methods have been reported, the test-retest reproducibility of the segmented habenula volume and the consistency of the boundaries of habenula segmentation have not been investigated. In this study, we evaluated the intra- and inter-site reproducibility of in vivo human habenula segmentation from 3T MRI (0.7-0.8 mm isotropic resolution) using our previously proposed semi-automated myelin contrast-based method and its fully-automated version, as well as a previously published manual geometry-based method. The habenula segmentation using our semi-automated method showed consistent boundary definition (high Dice coefficient, low mean distance, and moderate Hausdorff distance) and reproducible volume measurement (low coefficient of variation). Furthermore, the habenula boundary in our semi-automated segmentation from 3T MRI agreed well with that in the manual segmentation from 7T MRI (0.5 mm isotropic resolution) of the same subjects. Overall, our proposed semi-automated habenula segmentation showed reliable and reproducible habenula localization, while its fully-automated version offers an efficient way for large sample analysis. © 2018 Wiley Periodicals, Inc.

  2. Reliability data banks

    International Nuclear Information System (INIS)

    Cannon, A.G.; Bendell, A.

    1991-01-01

    Following an introductory chapter on Reliability, what is it, why it is needed, how it is achieved and measured, the principles of reliability data bases and analysis methodologies are the subject of the next two chapters. Achievements due to the development of data banks are mentioned for different industries in the next chapter, FACTS, a comprehensive information system for industrial safety and reliability data collection in process plants are covered next. CREDO, the Central Reliability Data Organization is described in the next chapter and is indexed separately, as is the chapter on DANTE, the fabrication reliability Data analysis system. Reliability data banks at Electricite de France and IAEA's experience in compiling a generic component reliability data base are also separately indexed. The European reliability data system, ERDS, and the development of a large data bank come next. The last three chapters look at 'Reliability data banks, - friend foe or a waste of time'? and future developments. (UK)

  3. Suncor maintenance and reliability

    Energy Technology Data Exchange (ETDEWEB)

    Little, S. [Suncor Energy, Calgary, AB (Canada)

    2006-07-01

    Fleet maintenance and reliability at Suncor Energy was discussed in this presentation, with reference to Suncor Energy's primary and support equipment fleets. This paper also discussed Suncor Energy's maintenance and reliability standard involving people, processes and technology. An organizational maturity chart that graphed organizational learning against organizational performance was illustrated. The presentation also reviewed the maintenance and reliability framework; maintenance reliability model; the process overview of the maintenance and reliability standard; a process flow chart of maintenance strategies and programs; and an asset reliability improvement process flow chart. An example of an improvement initiative was included, with reference to a shovel reliability review; a dipper trip reliability investigation; bucket related failures by type and frequency; root cause analysis of the reliability process; and additional actions taken. Last, the presentation provided a graph of the results of the improvement initiative and presented the key lessons learned. tabs., figs.

  4. The Accelerator Reliability Forum

    CERN Document Server

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  5. Using the mouse to model human disease: increasing validity and reproducibility

    Directory of Open Access Journals (Sweden)

    Monica J. Justice

    2016-02-01

    Full Text Available Experiments that use the mouse as a model for disease have recently come under scrutiny because of the repeated failure of data, particularly derived from preclinical studies, to be replicated or translated to humans. The usefulness of mouse models has been questioned because of irreproducibility and poor recapitulation of human conditions. Newer studies, however, point to bias in reporting results and improper data analysis as key factors that limit reproducibility and validity of preclinical mouse research. Inaccurate and incomplete descriptions of experimental conditions also contribute. Here, we provide guidance on best practice in mouse experimentation, focusing on appropriate selection and validation of the model, sources of variation and their influence on phenotypic outcomes, minimum requirements for control sets, and the importance of rigorous statistics. Our goal is to raise the standards in mouse disease modeling to enhance reproducibility, reliability and clinical translation of findings.

  6. Reproducible diagnosis of Chronic Lymphocytic Leukemia by flow cytometry

    DEFF Research Database (Denmark)

    Rawstron, Andy C; Kreuzer, Karl-Anton; Soosapilla, Asha

    2018-01-01

    The diagnostic criteria for CLL rely on morphology and immunophenotype. Current approaches have limitations affecting reproducibility and there is no consensus on the role of new markers. The aim of this project was to identify reproducible criteria and consensus on markers recommended for the di...

  7. Genotypic variability enhances the reproducibility of an ecological study.

    Science.gov (United States)

    Milcu, Alexandru; Puga-Freitas, Ruben; Ellison, Aaron M; Blouin, Manuel; Scheu, Stefan; Freschet, Grégoire T; Rose, Laura; Barot, Sebastien; Cesarz, Simone; Eisenhauer, Nico; Girin, Thomas; Assandri, Davide; Bonkowski, Michael; Buchmann, Nina; Butenschoen, Olaf; Devidal, Sebastien; Gleixner, Gerd; Gessler, Arthur; Gigon, Agnès; Greiner, Anna; Grignani, Carlo; Hansart, Amandine; Kayler, Zachary; Lange, Markus; Lata, Jean-Christophe; Le Galliard, Jean-François; Lukac, Martin; Mannerheim, Neringa; Müller, Marina E H; Pando, Anne; Rotter, Paula; Scherer-Lorenzen, Michael; Seyhun, Rahme; Urban-Mead, Katherine; Weigelt, Alexandra; Zavattaro, Laura; Roy, Jacques

    2018-02-01

    Many scientific disciplines are currently experiencing a 'reproducibility crisis' because numerous scientific findings cannot be repeated consistently. A novel but controversial hypothesis postulates that stringent levels of environmental and biotic standardization in experimental studies reduce reproducibility by amplifying the impacts of laboratory-specific environmental factors not accounted for in study designs. A corollary to this hypothesis is that a deliberate introduction of controlled systematic variability (CSV) in experimental designs may lead to increased reproducibility. To test this hypothesis, we had 14 European laboratories run a simple microcosm experiment using grass (Brachypodium distachyon L.) monocultures and grass and legume (Medicago truncatula Gaertn.) mixtures. Each laboratory introduced environmental and genotypic CSV within and among replicated microcosms established in either growth chambers (with stringent control of environmental conditions) or glasshouses (with more variable environmental conditions). The introduction of genotypic CSV led to 18% lower among-laboratory variability in growth chambers, indicating increased reproducibility, but had no significant effect in glasshouses where reproducibility was generally lower. Environmental CSV had little effect on reproducibility. Although there are multiple causes for the 'reproducibility crisis', deliberately including genetic variability may be a simple solution for increasing the reproducibility of ecological studies performed under stringently controlled environmental conditions.

  8. Participant Nonnaiveté and the reproducibility of cognitive psychology

    NARCIS (Netherlands)

    R.A. Zwaan (Rolf); D. Pecher (Diane); G. Paolacci (Gabriele); S. Bouwmeester (Samantha); P.P.J.L. Verkoeijen (Peter); K. Dijkstra (Katinka); R. Zeelenberg (René)

    2017-01-01

    textabstractMany argue that there is a reproducibility crisis in psychology. We investigated nine well-known effects from the cognitive psychology literature—three each from the domains of perception/action, memory, and language, respectively—and found that they are highly reproducible. Not only can

  9. Reproducing Kernels and Coherent States on Julia Sets

    Energy Technology Data Exchange (ETDEWEB)

    Thirulogasanthar, K., E-mail: santhar@cs.concordia.ca; Krzyzak, A. [Concordia University, Department of Computer Science and Software Engineering (Canada)], E-mail: krzyzak@cs.concordia.ca; Honnouvo, G. [Concordia University, Department of Mathematics and Statistics (Canada)], E-mail: g_honnouvo@yahoo.fr

    2007-11-15

    We construct classes of coherent states on domains arising from dynamical systems. An orthonormal family of vectors associated to the generating transformation of a Julia set is found as a family of square integrable vectors, and, thereby, reproducing kernels and reproducing kernel Hilbert spaces are associated to Julia sets. We also present analogous results on domains arising from iterated function systems.

  10. Reproducing Kernels and Coherent States on Julia Sets

    International Nuclear Information System (INIS)

    Thirulogasanthar, K.; Krzyzak, A.; Honnouvo, G.

    2007-01-01

    We construct classes of coherent states on domains arising from dynamical systems. An orthonormal family of vectors associated to the generating transformation of a Julia set is found as a family of square integrable vectors, and, thereby, reproducing kernels and reproducing kernel Hilbert spaces are associated to Julia sets. We also present analogous results on domains arising from iterated function systems

  11. Completely reproducible description of digital sound data with cellular automata

    International Nuclear Information System (INIS)

    Wada, Masato; Kuroiwa, Jousuke; Nara, Shigetoshi

    2002-01-01

    A novel method of compressive and completely reproducible description of digital sound data by means of rule dynamics of CA (cellular automata) is proposed. The digital data of spoken words and music recorded with the standard format of a compact disk are reproduced completely by this method with use of only two rules in a one-dimensional CA without loss of information

  12. Human Reliability Program Overview

    Energy Technology Data Exchange (ETDEWEB)

    Bodin, Michael

    2012-09-25

    This presentation covers the high points of the Human Reliability Program, including certification/decertification, critical positions, due process, organizational structure, program components, personnel security, an overview of the US DOE reliability program, retirees and academia, and security program integration.

  13. Power electronics reliability analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Mark A.; Atcitty, Stanley

    2009-12-01

    This report provides the DOE and industry with a general process for analyzing power electronics reliability. The analysis can help with understanding the main causes of failures, downtime, and cost and how to reduce them. One approach is to collect field maintenance data and use it directly to calculate reliability metrics related to each cause. Another approach is to model the functional structure of the equipment using a fault tree to derive system reliability from component reliability. Analysis of a fictitious device demonstrates the latter process. Optimization can use the resulting baseline model to decide how to improve reliability and/or lower costs. It is recommended that both electric utilities and equipment manufacturers make provisions to collect and share data in order to lay the groundwork for improving reliability into the future. Reliability analysis helps guide reliability improvements in hardware and software technology including condition monitoring and prognostics and health management.

  14. Reliability of software

    International Nuclear Information System (INIS)

    Kopetz, H.

    1980-01-01

    Common factors and differences in the reliability of hardware and software; reliability increase by means of methods of software redundancy. Maintenance of software for long term operating behavior. (HP) [de

  15. Reliable Design Versus Trust

    Science.gov (United States)

    Berg, Melanie; LaBel, Kenneth A.

    2016-01-01

    This presentation focuses on reliability and trust for the users portion of the FPGA design flow. It is assumed that the manufacturer prior to hand-off to the user tests FPGA internal components. The objective is to present the challenges of creating reliable and trusted designs. The following will be addressed: What makes a design vulnerable to functional flaws (reliability) or attackers (trust)? What are the challenges for verifying a reliable design versus a trusted design?

  16. Pocket Handbook on Reliability

    Science.gov (United States)

    1975-09-01

    exponencial distributions Weibull distribution, -xtimating reliability, confidence intervals, relia- bility growth, 0. P- curves, Bayesian analysis. 20 A S...introduction for those not familiar with reliability and a good refresher for those who are currently working in the area. LEWIS NERI, CHIEF...includes one or both of the following objectives: a) prediction of the current system reliability, b) projection on the system reliability for someI future

  17. Principles of Bridge Reliability

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, Andrzej S.

    The paper gives a brief introduction to the basic principles of structural reliability theory and its application to bridge engineering. Fundamental concepts like failure probability and reliability index are introduced. Ultimate as well as serviceability limit states for bridges are formulated......, and as an example the reliability profile and a sensitivity analyses for a corroded reinforced concrete bridge is shown....

  18. Reliability in engineering '87

    International Nuclear Information System (INIS)

    Tuma, M.

    1987-01-01

    The participants heard 51 papers dealing with the reliability of engineering products. Two of the papers were incorporated in INIS, namely ''Reliability comparison of two designs of low pressure regeneration of the 1000 MW unit at the Temelin nuclear power plant'' and ''Use of probability analysis of reliability in designing nuclear power facilities.''(J.B.)

  19. Measurement and Reproducibility of Preserved Ellipsoid Zone Area and Preserved Retinal Pigment Epithelium Area in Eyes With Choroideremia

    DEFF Research Database (Denmark)

    Hariri, Amir H; Velaga, Swetha B; Girach, Aniz

    2017-01-01

    PURPOSE: To identify valid and reproducible methods for quantifying anatomic outcome measures for eyes with choroideremia (CHM) in clinical trials. DESIGN: Reliability analysis study. METHODS: In this multicenter study, patients with confirmed genetic diagnosis of CHM were enrolled. All cases...... of both FAF and OCT images were compared to assess the reproducibility of the grading methods. RESULTS: A total of 148 eyes from 75 cases were included. In 21% of eyes PAF and in 43% of eyes preserved EZ had extended beyond the image capture area. After exclusion of these eyes and low-quality images, 114...

  20. Container-Based Clinical Solutions for Portable and Reproducible Image Analysis.

    Science.gov (United States)

    Matelsky, Jordan; Kiar, Gregory; Johnson, Erik; Rivera, Corban; Toma, Michael; Gray-Roncal, William

    2018-05-08

    Medical imaging analysis depends on the reproducibility of complex computation. Linux containers enable the abstraction, installation, and configuration of environments so that software can be both distributed in self-contained images and used repeatably by tool consumers. While several initiatives in neuroimaging have adopted approaches for creating and sharing more reliable scientific methods and findings, Linux containers are not yet mainstream in clinical settings. We explore related technologies and their efficacy in this setting, highlight important shortcomings, demonstrate a simple use-case, and endorse the use of Linux containers for medical image analysis.

  1. Effect of Initial Conditions on Reproducibility of Scientific Research

    Science.gov (United States)

    Djulbegovic, Benjamin; Hozo, Iztok

    2014-01-01

    Background: It is estimated that about half of currently published research cannot be reproduced. Many reasons have been offered as explanations for failure to reproduce scientific research findings- from fraud to the issues related to design, conduct, analysis, or publishing scientific research. We also postulate a sensitive dependency on initial conditions by which small changes can result in the large differences in the research findings when attempted to be reproduced at later times. Methods: We employed a simple logistic regression equation to model the effect of covariates on the initial study findings. We then fed the input from the logistic equation into a logistic map function to model stability of the results in repeated experiments over time. We illustrate the approach by modeling effects of different factors on the choice of correct treatment. Results: We found that reproducibility of the study findings depended both on the initial values of all independent variables and the rate of change in the baseline conditions, the latter being more important. When the changes in the baseline conditions vary by about 3.5 to about 4 in between experiments, no research findings could be reproduced. However, when the rate of change between the experiments is ≤2.5 the results become highly predictable between the experiments. Conclusions: Many results cannot be reproduced because of the changes in the initial conditions between the experiments. Better control of the baseline conditions in-between the experiments may help improve reproducibility of scientific findings. PMID:25132705

  2. Reliable computer systems.

    Science.gov (United States)

    Wear, L L; Pinkert, J R

    1993-11-01

    In this article, we looked at some decisions that apply to the design of reliable computer systems. We began with a discussion of several terms such as testability, then described some systems that call for highly reliable hardware and software. The article concluded with a discussion of methods that can be used to achieve higher reliability in computer systems. Reliability and fault tolerance in computers probably will continue to grow in importance. As more and more systems are computerized, people will want assurances about the reliability of these systems, and their ability to work properly even when sub-systems fail.

  3. Human factor reliability program

    International Nuclear Information System (INIS)

    Knoblochova, L.

    2017-01-01

    The human factor's reliability program was at Slovenske elektrarne, a.s. (SE) nuclear power plants. introduced as one of the components Initiatives of Excellent Performance in 2011. The initiative's goal was to increase the reliability of both people and facilities, in response to 3 major areas of improvement - Need for improvement of the results, Troubleshooting support, Supporting the achievement of the company's goals. The human agent's reliability program is in practice included: - Tools to prevent human error; - Managerial observation and coaching; - Human factor analysis; -Quick information about the event with a human agent; -Human reliability timeline and performance indicators; - Basic, periodic and extraordinary training in human factor reliability(authors)

  4. Reproducibility of R-fMRI metrics on the impact of different strategies for multiple comparison correction and sample sizes.

    Science.gov (United States)

    Chen, Xiao; Lu, Bin; Yan, Chao-Gan

    2018-01-01

    Concerns regarding reproducibility of resting-state functional magnetic resonance imaging (R-fMRI) findings have been raised. Little is known about how to operationally define R-fMRI reproducibility and to what extent it is affected by multiple comparison correction strategies and sample size. We comprehensively assessed two aspects of reproducibility, test-retest reliability and replicability, on widely used R-fMRI metrics in both between-subject contrasts of sex differences and within-subject comparisons of eyes-open and eyes-closed (EOEC) conditions. We noted permutation test with Threshold-Free Cluster Enhancement (TFCE), a strict multiple comparison correction strategy, reached the best balance between family-wise error rate (under 5%) and test-retest reliability/replicability (e.g., 0.68 for test-retest reliability and 0.25 for replicability of amplitude of low-frequency fluctuations (ALFF) for between-subject sex differences, 0.49 for replicability of ALFF for within-subject EOEC differences). Although R-fMRI indices attained moderate reliabilities, they replicated poorly in distinct datasets (replicability < 0.3 for between-subject sex differences, < 0.5 for within-subject EOEC differences). By randomly drawing different sample sizes from a single site, we found reliability, sensitivity and positive predictive value (PPV) rose as sample size increased. Small sample sizes (e.g., < 80 [40 per group]) not only minimized power (sensitivity < 2%), but also decreased the likelihood that significant results reflect "true" effects (PPV < 0.26) in sex differences. Our findings have implications for how to select multiple comparison correction strategies and highlight the importance of sufficiently large sample sizes in R-fMRI studies to enhance reproducibility. Hum Brain Mapp 39:300-318, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  5. Reproducible and controllable induction voltage adder for scaled beam experiments

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Yasuo; Nakajima, Mitsuo; Horioka, Kazuhiko [Department of Energy Sciences, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan)

    2016-08-15

    A reproducible and controllable induction adder was developed using solid-state switching devices and Finemet cores for scaled beam compression experiments. A gate controlled MOSFET circuit was developed for the controllable voltage driver. The MOSFET circuit drove the induction adder at low magnetization levels of the cores which enabled us to form reproducible modulation voltages with jitter less than 0.3 ns. Preliminary beam compression experiments indicated that the induction adder can improve the reproducibility of modulation voltages and advance the beam physics experiments.

  6. Improving Reliability of a Residency Interview Process

    Science.gov (United States)

    Serres, Michelle L.; Gundrum, Todd E.

    2013-01-01

    Objective. To improve the reliability and discrimination of a pharmacy resident interview evaluation form, and thereby improve the reliability of the interview process. Methods. In phase 1 of the study, authors used a Many-Facet Rasch Measurement model to optimize an existing evaluation form for reliability and discrimination. In phase 2, interviewer pairs used the modified evaluation form within 4 separate interview stations. In phase 3, 8 interviewers individually-evaluated each candidate in one-on-one interviews. Results. In phase 1, the evaluation form had a reliability of 0.98 with person separation of 6.56; reproducibly, the form separated applicants into 6 distinct groups. Using that form in phase 2 and 3, our largest variation source was candidates, while content specificity was the next largest variation source. The phase 2 g-coefficient was 0.787, while confirmatory phase 3 was 0.922. Process reliability improved with more stations despite fewer interviewers per station—impact of content specificity was greatly reduced with more interview stations. Conclusion. A more reliable, discriminating evaluation form was developed to evaluate candidates during resident interviews, and a process was designed that reduced the impact from content specificity. PMID:24159209

  7. Improving reliability of a residency interview process.

    Science.gov (United States)

    Peeters, Michael J; Serres, Michelle L; Gundrum, Todd E

    2013-10-14

    To improve the reliability and discrimination of a pharmacy resident interview evaluation form, and thereby improve the reliability of the interview process. In phase 1 of the study, authors used a Many-Facet Rasch Measurement model to optimize an existing evaluation form for reliability and discrimination. In phase 2, interviewer pairs used the modified evaluation form within 4 separate interview stations. In phase 3, 8 interviewers individually-evaluated each candidate in one-on-one interviews. In phase 1, the evaluation form had a reliability of 0.98 with person separation of 6.56; reproducibly, the form separated applicants into 6 distinct groups. Using that form in phase 2 and 3, our largest variation source was candidates, while content specificity was the next largest variation source. The phase 2 g-coefficient was 0.787, while confirmatory phase 3 was 0.922. Process reliability improved with more stations despite fewer interviewers per station-impact of content specificity was greatly reduced with more interview stations. A more reliable, discriminating evaluation form was developed to evaluate candidates during resident interviews, and a process was designed that reduced the impact from content specificity.

  8. Establishment of reproducible osteosarcoma rat model using orthotopic implantation technique.

    Science.gov (United States)

    Yu, Zhe; Sun, Honghui; Fan, Qingyu; Long, Hua; Yang, Tongtao; Ma, Bao'an

    2009-05-01

    In experimental musculoskeletal oncology, there remains a need for animal models that can be used to assess the efficacy of new and innovative treatment methodologies for bone tumors. Rat plays a very important role in the bone field especially in the evaluation of metabolic bone diseases. The objective of this study was to develop a rat osteosarcoma model for evaluation of new surgical and molecular methods of treatment for extremity sarcoma. One hundred male SD rats weighing 125.45+/-8.19 g were divided into 5 groups and anesthetized intraperitoneally with 10% chloral hydrate. Orthotopic implantation models of rat osteosarcoma were performed by injecting directly into the SD rat femur with a needle for inoculation with SD tumor cells. In the first step of the experiment, 2x10(5) to 1x10(6) UMR106 cells in 50 microl were injected intraosseously into median or distal part of the femoral shaft and the tumor take rate was determined. The second stage consisted of determining tumor volume, correlating findings from ultrasound with findings from necropsia and determining time of survival. In the third stage, the orthotopically implanted tumors and lung nodules were resected entirely, sectioned, and then counter stained with hematoxylin and eosin for histopathologic evaluation. The tumor take rate was 100% for implants with 8x10(5) tumor cells or more, which was much less than the amount required for subcutaneous implantation, with a high lung metastasis rate of 93.0%. Ultrasound and necropsia findings matched closely (r=0.942; p<0.01), which demonstrated that Doppler ultrasonography is a convenient and reliable technique for measuring cancer at any stage. Tumor growth curve showed that orthotopically implanted tumors expanded vigorously with time-lapse, especially in the first 3 weeks. The median time of survival was 38 days and surgical mortality was 0%. The UMR106 cell line has strong carcinogenic capability and high lung metastasis frequency. The present rat

  9. Intra- and interobserver reproducibility of vertebral endplate signal (modic) changes in the lumbar spine

    DEFF Research Database (Denmark)

    Jensen, Tue Secher; Sorensen, Joan Solgaard; Kjær, Per

    2007-01-01

    . PURPOSE: To assess the intra- and interobserver reliability of the "Nordic Modic classification" protocol. MATERIAL AND METHODS: MRI scans of 50 individuals representative of the general Danish population aged 40 were evaluated by two observers. Criteria for grading the changes were developed...... by the Nordic Modic Consensus Group. After consensus was established, all 50 MRI examinations were evaluated independently by each observer. Intraobserver reliability was assessed by re-evaluation of the 50 examinations by one of the observers. Kappa statistics were used to calculate agreement. RESULTS: Intra....... CONCLUSION: In this study, we found convincing reproducibility of a detailed evaluation protocol of vertebral endplate signal changes, the "Nordic Modic Classification." The authors recommend that the evaluation protocol should be used in future studies investigating vertebral endplate signal changes....

  10. Reproducibility of corneal, macular and retinal nerve fiber layer ...

    African Journals Online (AJOL)

    side the limits of a consulting room.5. Reproducibility of ... examination, intraocular pressure and corneal thickness ... All OCT measurements were taken between 2 and 5 pm ..... CAS-OCT, Slit-lamp OCT, RTVue-100) have shown ICC.

  11. Beyond Bundles - Reproducible Software Environments with GNU Guix

    CERN Multimedia

    CERN. Geneva; Wurmus, Ricardo

    2018-01-01

    Building reproducible data analysis pipelines and numerical experiments is a key challenge for reproducible science, in which tools to reproduce software environments play a critical role. The advent of “container-based” deployment tools such as Docker and Singularity has made it easier to replicate software environments. These tools are very much about bundling the bits of software binaries in a convenient way, not so much about describing how software is composed. Science is not just about replicating, though—it demands the ability to inspect and to experiment. In this talk we will present GNU Guix, a software management toolkit. Guix departs from container-based solutions in that it enables declarative composition of software environments. It is comparable to “package managers” like apt or yum, but with a significant difference: Guix provides accurate provenance tracking of build artifacts, and bit-reproducible software. We will illustrate the many ways in which Guix can improve how software en...

  12. The reproducibility of random amplified polymorphic DNA (RAPD ...

    African Journals Online (AJOL)

    RAPD) profiles of Streptococcus thermophilus strains by using the polymerase chain reaction (PCR). Several factors can cause the amplification of false and non reproducible bands in the RAPD profiles. We tested three primers, OPI-02 MOD, ...

  13. Systematic heterogenization for better reproducibility in animal experimentation.

    Science.gov (United States)

    Richter, S Helene

    2017-08-31

    The scientific literature is full of articles discussing poor reproducibility of findings from animal experiments as well as failures to translate results from preclinical animal studies to clinical trials in humans. Critics even go so far as to talk about a "reproducibility crisis" in the life sciences, a novel headword that increasingly finds its way into numerous high-impact journals. Viewed from a cynical perspective, Fett's law of the lab "Never replicate a successful experiment" has thus taken on a completely new meaning. So far, poor reproducibility and translational failures in animal experimentation have mostly been attributed to biased animal data, methodological pitfalls, current publication ethics and animal welfare constraints. More recently, the concept of standardization has also been identified as a potential source of these problems. By reducing within-experiment variation, rigorous standardization regimes limit the inference to the specific experimental conditions. In this way, however, individual phenotypic plasticity is largely neglected, resulting in statistically significant but possibly irrelevant findings that are not reproducible under slightly different conditions. By contrast, systematic heterogenization has been proposed as a concept to improve representativeness of study populations, contributing to improved external validity and hence improved reproducibility. While some first heterogenization studies are indeed very promising, it is still not clear how this approach can be transferred into practice in a logistically feasible and effective way. Thus, further research is needed to explore different heterogenization strategies as well as alternative routes toward better reproducibility in animal experimentation.

  14. Fabrication of reproducible, integration-compatible hybrid molecular/si electronics.

    Science.gov (United States)

    Yu, Xi; Lovrinčić, Robert; Kraynis, Olga; Man, Gabriel; Ely, Tal; Zohar, Arava; Toledano, Tal; Cahen, David; Vilan, Ayelet

    2014-12-29

    Reproducible molecular junctions can be integrated within standard CMOS technology. Metal-molecule-semiconductor junctions are fabricated by direct Si-C binding of hexadecane or methyl-styrene onto oxide-free H-Si(111) surfaces, with the lateral size of the junctions defined by an etched SiO2 well and with evaporated Pb as the top contact. The current density, J, is highly reproducible with a standard deviation in log(J) of 0.2 over a junction diameter change from 3 to 100 μm. Reproducibility over such a large range indicates that transport is truly across the molecules and does not result from artifacts like edge effects or defects in the molecular monolayer. Device fabrication is tested for two n-Si doping levels. With highly doped Si, transport is dominated by tunneling and reveals sharp conductance onsets at room temperature. Using the temperature dependence of current across medium-doped n-Si, the molecular tunneling barrier can be separated from the Si-Schottky one, which is a 0.47 eV, in agreement with the molecular-modified surface dipole and quite different from the bare Si-H junction. This indicates that Pb evaporation does not cause significant chemical changes to the molecules. The ability to manufacture reliable devices constitutes important progress toward possible future hybrid Si-based molecular electronics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Design of reproducible polarized and non-polarized edge filters using genetic algorithm

    International Nuclear Information System (INIS)

    Ejigu, Efrem Kebede; Lacquet, B M

    2010-01-01

    Recent advancement in optical fibre communications technology is partly due to the advancement of optical thin film technology. The advancement of optical thin film technology includes the development of new and existing optical filter design methods. The genetic algorithm is one of the new design methods that show promising results in designing a number of complicated design specifications. It is the finding of this study that the genetic algorithm design method, through its optimization capability, can give more reliable and reproducible designs of any specifications. The design method in this study optimizes the thickness of each layer to get to the best possible solution. Its capability and unavoidable limitations in designing polarized and non-polarized edge filters from absorptive and dispersive materials is well demonstrated. It is also demonstrated that polarized and non-polarized designs from the genetic algorithm are reproducible with great success. This research has accomplished the great task of formulating a computer program using the genetic algorithm in a Matlab environment for the design of a reproducible polarized and non-polarized filters of any sort from any kind of materials

  16. Long-term reproducibility of in vivo measures of specific binding of radioligands in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Kilbourn, Michael R. E-mail: mkilbour@umich.edu

    2004-07-01

    The long-term reproducibility of measures of in vivo specific binding of radiolabeled forms of (+)-{alpha}-dihydrotetrabenazine (DTBZ) and d-threo-methylphenidate (MPH) in rat brain was examined. All studies were done using a consistent bolus plus infusion protocol and calculation of equilibrium distribution volume ratios (DVR). Over a period of eight years striatal DVR values for DTBZ binding to the vesicular monoamine transporter 2 (VMAT2) in young adult (8-10 wks old) rats showed very good reproducibility (3.62{+-}0.33, N=35). Equivalent values were obtained using either tritiated or carbon-11 labeled DTBZ, and were irrespective of sex of animals. Older animals (78 wks old) showed losses (-45%) of specific binding. Striatal binding of MPH to the dopamine transporter (DAT) showed a similar reproducibility over a five year period (DVR=2.17{+-}0.39, N=52), again irrespective of radionuclide or sex. These studies demonstrate that use of a consistent in vivo technique can provide reliable measures of specific binding of radioligands to high affinity sites in the rat brain.

  17. Reliability and safety engineering

    CERN Document Server

    Verma, Ajit Kumar; Karanki, Durga Rao

    2016-01-01

    Reliability and safety are core issues that must be addressed throughout the life cycle of engineering systems. Reliability and Safety Engineering presents an overview of the basic concepts, together with simple and practical illustrations. The authors present reliability terminology in various engineering fields, viz.,electronics engineering, software engineering, mechanical engineering, structural engineering and power systems engineering. The book describes the latest applications in the area of probabilistic safety assessment, such as technical specification optimization, risk monitoring and risk informed in-service inspection. Reliability and safety studies must, inevitably, deal with uncertainty, so the book includes uncertainty propagation methods: Monte Carlo simulation, fuzzy arithmetic, Dempster-Shafer theory and probability bounds. Reliability and Safety Engineering also highlights advances in system reliability and safety assessment including dynamic system modeling and uncertainty management. Cas...

  18. Reproducibility and relative validity of food group intake in a food frequency questionnaire developed for Nepalese diet.

    Science.gov (United States)

    Shrestha, Archana; Koju, Rajendra Prasad; Beresford, Shirley A A; Chan, Kwun Chuen Gary; Connell, Frederik A; Karmacharya, Biraj Man; Shrestha, Pramita; Fitzpatrick, Annette L

    2017-08-01

    We developed a food frequency questionnaire (FFQ) designed to measure the dietary practices of adult Nepalese. The present study examined the validity and reproducibility of the FFQ. To evaluate the reproducibility of the FFQ, 116 subjects completed two 115-item FFQ across a four-month interval. Six 24-h dietary recalls were collected (1 each month) to assess the validity of the FFQ. Seven major food groups and 23 subgroups were clustered from the FFQ based on macronutrient composition. Spearman correlation coefficients evaluating reproducibility for all food groups were greater than 0.5, with the exceptions of oil. The correlations varied from 0.41 (oil) to 0.81 (vegetables). All crude spearman coefficients for validity were greater than 0.5 except for dairy products, pizzas/pastas and sausage/burgers. The FFQ was found to be reliable and valid for ranking the intake of food groups for Nepalese dietary intake.

  19. Human reliability analysis

    International Nuclear Information System (INIS)

    Dougherty, E.M.; Fragola, J.R.

    1988-01-01

    The authors present a treatment of human reliability analysis incorporating an introduction to probabilistic risk assessment for nuclear power generating stations. They treat the subject according to the framework established for general systems theory. Draws upon reliability analysis, psychology, human factors engineering, and statistics, integrating elements of these fields within a systems framework. Provides a history of human reliability analysis, and includes examples of the application of the systems approach

  20. Reliability of electronic systems

    International Nuclear Information System (INIS)

    Roca, Jose L.

    2001-01-01

    Reliability techniques have been developed subsequently as a need of the diverse engineering disciplines, nevertheless they are not few those that think they have been work a lot on reliability before the same word was used in the current context. Military, space and nuclear industries were the first ones that have been involved in this topic, however not only in these environments it is that it has been carried out this small great revolution in benefit of the increase of the reliability figures of the products of those industries, but rather it has extended to the whole industry. The fact of the massive production, characteristic of the current industries, drove four decades ago, to the fall of the reliability of its products, on one hand, because the massively itself and, for other, to the recently discovered and even not stabilized industrial techniques. Industry should be changed according to those two new requirements, creating products of medium complexity and assuring an enough reliability appropriated to production costs and controls. Reliability began to be integral part of the manufactured product. Facing this philosophy, the book describes reliability techniques applied to electronics systems and provides a coherent and rigorous framework for these diverse activities providing a unifying scientific basis for the entire subject. It consists of eight chapters plus a lot of statistical tables and an extensive annotated bibliography. Chapters embrace the following topics: 1- Introduction to Reliability; 2- Basic Mathematical Concepts; 3- Catastrophic Failure Models; 4-Parametric Failure Models; 5- Systems Reliability; 6- Reliability in Design and Project; 7- Reliability Tests; 8- Software Reliability. This book is in Spanish language and has a potentially diverse audience as a text book from academic to industrial courses. (author)

  1. The paediatric flat foot proforma (p-FFP: improved and abridged following a reproducibility study

    Directory of Open Access Journals (Sweden)

    Nicholson Hollie

    2009-08-01

    Full Text Available Abstract Background Concern about a child's flat foot posture is a common reason for frequent clinical consultations for an array of health care and medical professionals. The recently developed paediatric flatfoot clinical-care pathway (FFP has provided an evidence based approach to diagnosis and management. The intra and inter-rater/measurer reliability of the FFP has been investigated in this study. Methods From a study population of 140 children aged seven to 10 years, a sample with flat feet was identified by screening with the Foot posture index (FPI-6. Subjects who scored ≥ 6 on the FPI-6 for both feet became the study's flat foot sample. A same subject, repeated measure research design was used for this study which examined the reliability of the FFP in 31 children aged seven to 10 years, as rated by three examiners. Results Approximately half of the items of the FFP showed less-than-desirable inter-rater reliability, arbitrarily set at the conventional 0.7 level (intra-class correlations. Removal of the unreliable items has produced a shorter; more relevant instrument designated the paediatric flat foot proforma (p-FFP. Conclusion The p-FFP is a reliable instrument for the assessment and resulting treatment actions for children with flat feet. Findings indicate that the simplified p-FFP is a reproducible instrument for the clinical assessment of flat foot in mid-childhood.

  2. A Reproducible Computerized Method for Quantitation of Capillary Density using Nailfold Capillaroscopy.

    Science.gov (United States)

    Cheng, Cynthia; Lee, Chadd W; Daskalakis, Constantine

    2015-10-27

    Capillaroscopy is a non-invasive, efficient, relatively inexpensive and easy to learn methodology for directly visualizing the microcirculation. The capillaroscopy technique can provide insight into a patient's microvascular health, leading to a variety of potentially valuable dermatologic, ophthalmologic, rheumatologic and cardiovascular clinical applications. In addition, tumor growth may be dependent on angiogenesis, which can be quantitated by measuring microvessel density within the tumor. However, there is currently little to no standardization of techniques, and only one publication to date reports the reliability of a currently available, complex computer based algorithms for quantitating capillaroscopy data.(1) This paper describes a new, simpler, reliable, standardized capillary counting algorithm for quantitating nailfold capillaroscopy data. A simple, reproducible computerized capillaroscopy algorithm such as this would facilitate more widespread use of the technique among researchers and clinicians. Many researchers currently analyze capillaroscopy images by hand, promoting user fatigue and subjectivity of the results. This paper describes a novel, easy-to-use automated image processing algorithm in addition to a reproducible, semi-automated counting algorithm. This algorithm enables analysis of images in minutes while reducing subjectivity; only a minimal amount of training time (in our experience, less than 1 hr) is needed to learn the technique.

  3. [Reproducibility of Fuhrman nuclear grade: advantages of a two-grade system].

    Science.gov (United States)

    Letourneux, Hervé; Lindner, Véronique; Lang, Hervé; Massfelder, Thierry; Meyer, Nicolas; Saussine, Christian; Jacqmin, Didier

    2006-06-01

    The Fuhrman nuclear grade is the reference histoprognostic grading system routinely used all over the world for renal cell carcinoma. Studies measuring the inter-observer and intra-observer concordance of Fuhrman grade show poor results in terms of reproducibility and repeatability. These variations are due to a certain degree of subjectivity of the pathologist in application of the definition of tumour grade, particularly nuclear grade. Elements able to account for this subjectivity in renal cell carcinoma are identified from a review of the literature. To improve the reliability of nuclear grade, the territory occupied by the highest grade must be specified and the grades should probably be combined. At the present time, regrouping of grade 1 and 2 tumours as low grade and grade 3 and 4 tumours as high grade would achieve better reproducibility, while preserving the prognostic: value for overall survival. The development of new treatment modalities and their use in adjuvant situations will imply the use of reliable histoprognostic factors to specify, indications.

  4. Reproducibility of ZrO2-based freeze casting for biomaterials.

    Science.gov (United States)

    Naleway, Steven E; Fickas, Kate C; Maker, Yajur N; Meyers, Marc A; McKittrick, Joanna

    2016-04-01

    The processing technique of freeze casting has been intensely researched for its potential to create porous scaffold and infiltrated composite materials for biomedical implants and structural materials. However, in order for this technique to be employed medically or commercially, it must be able to reliably produce materials in great quantities with similar microstructures and properties. Here we investigate the reproducibility of the freeze casting process by independently fabricating three sets of eight ZrO2-epoxy composite scaffolds with the same processing conditions but varying solid loading (10, 15 and 20 vol.%). Statistical analyses (One-way ANOVA and Tukey's HSD tests) run upon measurements of the microstructural dimensions of these composite scaffold sets show that, while the majority of microstructures are similar, in all cases the composite scaffolds display statistically significant variability. In addition, composite scaffolds where mechanically compressed and statistically analyzed. Similar to the microstructures, almost all of their resultant properties displayed significant variability though most composite scaffolds were similar. These results suggest that additional research to improve control of the freeze casting technique is required before scaffolds and composite scaffolds can reliably be reproduced for commercial or medical applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Reliability and validity of emergency department triage systems

    NARCIS (Netherlands)

    van der Wulp, I.

    2010-01-01

    Reliability and validity of triage systems is important because this can affect patient safety. In this thesis, these aspects of two emergency department (ED) triage systems were studied as well as methodological aspects in these types of studies. The consistency, reproducibility, and criterion

  6. Operational safety reliability research

    International Nuclear Information System (INIS)

    Hall, R.E.; Boccio, J.L.

    1986-01-01

    Operating reactor events such as the TMI accident and the Salem automatic-trip failures raised the concern that during a plant's operating lifetime the reliability of systems could degrade from the design level that was considered in the licensing process. To address this concern, NRC is sponsoring the Operational Safety Reliability Research project. The objectives of this project are to identify the essential tasks of a reliability program and to evaluate the effectiveness and attributes of such a reliability program applicable to maintaining an acceptable level of safety during the operating lifetime at the plant

  7. Circuit design for reliability

    CERN Document Server

    Cao, Yu; Wirth, Gilson

    2015-01-01

    This book presents physical understanding, modeling and simulation, on-chip characterization, layout solutions, and design techniques that are effective to enhance the reliability of various circuit units.  The authors provide readers with techniques for state of the art and future technologies, ranging from technology modeling, fault detection and analysis, circuit hardening, and reliability management. Provides comprehensive review on various reliability mechanisms at sub-45nm nodes; Describes practical modeling and characterization techniques for reliability; Includes thorough presentation of robust design techniques for major VLSI design units; Promotes physical understanding with first-principle simulations.

  8. The Accuracy and Reproducibility of Linear Measurements Made on CBCT-derived Digital Models.

    Science.gov (United States)

    Maroua, Ahmad L; Ajaj, Mowaffak; Hajeer, Mohammad Y

    2016-04-01

    To evaluate the accuracy and reproducibility of linear measurements made on cone-beam computed tomography (CBCT)-derived digital models. A total of 25 patients (44% female, 18.7 ± 4 years) who had CBCT images for diagnostic purposes were included. Plaster models were obtained and digital models were extracted from CBCT scans. Seven linear measurements from predetermined landmarks were measured and analyzed on plaster models and the corresponding digital models. The measurements included arch length and width at different sites. Paired t test and Bland-Altman analysis were used to evaluate the accuracy of measurements on digital models compared to the plaster models. Also, intraclass correlation coefficients (ICCs) were used to evaluate the reproducibility of the measurements in order to assess the intraobserver reliability. The statistical analysis showed significant differences on 5 out of 14 variables, and the mean differences ranged from -0.48 to 0.51 mm. The Bland-Altman analysis revealed that the mean difference between variables was (0.14 ± 0.56) and (0.05 ± 0.96) mm and limits of agreement between the two methods ranged from -1.2 to 0.96 and from -1.8 to 1.9 mm in the maxilla and the mandible, respectively. The intraobserver reliability values were determined for all 14 variables of two types of models separately. The mean ICC value for the plaster models was 0.984 (0.924-0.999), while it was 0.946 for the CBCT models (range from 0.850 to 0.985). Linear measurements obtained from the CBCT-derived models appeared to have a high level of accuracy and reproducibility.

  9. Reproducibility and comparative validity of a food frequency questionnaire for Australian adults.

    Science.gov (United States)

    Collins, Clare E; Boggess, May M; Watson, Jane F; Guest, Maya; Duncanson, Kerith; Pezdirc, Kristine; Rollo, Megan; Hutchesson, Melinda J; Burrows, Tracy L

    2014-10-01

    Food frequency questionnaires (FFQ) are used in epidemiological studies to investigate the relationship between diet and disease. There is a need for a valid and reliable adult FFQ with a contemporary food list in Australia. To evaluate the reproducibility and comparative validity of the Australian Eating Survey (AES) FFQ in adults compared to weighed food records (WFRs). Two rounds of AES and three-day WFRs were conducted in 97 adults (31 males, median age and BMI for males of 44.9 years, 26.2 kg/m(2), females 41.3 years, 24.0 kg/m(2). Reproducibility was assessed over six months using Wilcoxon signed-rank tests and comparative validity was assessed by intraclass correlation coefficients (ICC) estimated by fitting a mixed effects model for each nutrient to account for age, sex and BMI to allow estimation of between and within person variance. Reproducibility was found to be good for both WFR and FFQ since there were no significant differences between round 1 and 2 administrations. For comparative validity, FFQ ICCs were at least as large as those for WFR. The ICC of the WFR-FFQ difference for total energy intake was 0.6 (95% CI 0.43, 0.77) and the median ICC for all nutrients was 0.47, with all ICCs between 0.15 (%E from saturated fat) and 0.7 (g/day sugars). Compared to WFR the AES FFQ is suitable for reliably estimating the dietary intakes of Australian adults across a wide range of nutrients. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  10. Reproducibility of the interpretation of pelvic x-ray 3 months after hysteroscopic sterilization with Essure.

    Science.gov (United States)

    Veersema, Sebastiaan; Mol, Ben W J; Brölmann, Hans A M

    2010-09-01

    To estimate the diagnostic accuracy and the interobserver reproducibility of pelvic x-rays in the diagnosis of successful bilateral sterilization with Essure after a 3-month follow-up period. Interobserver study. Outpatient department of obstetrics and gynecology in a Dutch teaching hospital. Patients with successful bilateral Essure placement. Hysteroscopic sterilization with Essure and pelvic x-ray and hysterosalpingography after a 3-month follow-up period. Six observers evaluations of 47 pelvic x-rays from 47 patients 3 months after a technical successful bilateral placement of microinserts to estimate the reliability of the sterilization. Diagnostic accuracy of pelvic x-ray per observer in detecting incorrectly positioned microinserts was expressed in terms of sensitivity and specificity, with hysterosalpingography as the reference strategy. Reproducibility of the interpretation of the pelvic x-ray was expressed as kappa-values. The sensitivity and specificity for x-rays read by gynecologists was 0.67 (95% confidence interval [CI], 0.29-0.96) and 0.79 (95% CI, 0.58-1.00) and for radiologists 1.0 and 0.5 (95% CI, 0.36-0.64). The interobserver agreement in reliability of pelvic x-ray of hysteroscopic sterilization assessment with Essure ranged from slight (kappa-value=0.09) for gynecologists to moderate (kappa-value=0.52) for radiologists. Test characteristics of pelvic x-ray as the imaging technique to assess the position of the Essure microinserts and tubal patency were poor, as was the reproducibility, particularly if gynecologists performed the evaluation. We do not recommend the use of pelvic x-ray for the assessment of the positioning of microinserts after hysteroscopic sterilization. Copyright (c) 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  11. Reproducibility of biomarkers in induced sputum and in serum from chronic smokers.

    Science.gov (United States)

    Zuiker, Rob G J A; Kamerling, Ingrid M C; Morelli, Nicoletta; Calderon, Cesar; Boot, J Diderik; de Kam, Marieke; Diamant, Zuzana; Burggraaf, Jacobus; Cohen, Adam F

    2015-08-01

    Soluble inflammatory markers obtained from non-invasive airway sampling such as induced sputum may be useful biomarkers for targeted pharmaceutical interventions. However, before these soluble markers can be used as potential targets, their variability and reproducibility need to be established in distinct study populations. This study aimed to assess the reproducibility of biomarkers obtained from induced sputum and serum in chronic smokers and non-smokers. Sputum and serum samples were obtained from 16 healthy non-smokers and 16 asymptomatic chronic smokers (for both groups: 8M/8F, 30-52 years, FEV1 ≥80% pred.; ≥10 pack years for the smokers) on 2 separate visits 4-10 days apart. Soluble markers in serum and sputum were analysed by ELISA. The differences between smokers vs non-smokers were analysed with a t-test and variability was assessed on log-transformed data by a mixed model ANOVA. Analysable sputum samples could be obtained from all 32 subjects. In both study populations neutrophils and macrophages were the predominant cell types. Serum Pulmonary Surfactant Associated Protein D had favourable reproducibility criteria for reliability ratio (0.99), intra-subject coefficient of variation (11.2%) and the Bland Altman limits of agreement. Furthermore, chronic smokers, compared to non-smokers, had significantly higher sputum concentrations of IL-8 (1094.6 pg/mL vs 460.8 pg/mL, p = 0.006)), and higher serum concentrations of Pulmonary Surfactant Associated Protein D (110.9 pg/mL vs 64.7 pg/mL, p = 0.019), and lower concentrations of Serum Amyloid A (1352.4 pg/mL vs 2297.5 pg/mL, p = 0.022). Serum Pulmonary Surfactant Associated Protein D proved to be a biomarker that fulfilled the criteria for reproducibility in both study groups. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Reproducibility of ad libitum energy intake with the use of a computerized vending machine system123

    Science.gov (United States)

    Votruba, Susanne B; Franks, Paul W; Krakoff, Jonathan; Salbe, Arline D

    2010-01-01

    Background: Accurate assessment of energy intake is difficult but critical for the evaluation of eating behavior and intervention effects. Consequently, methods to assess ad libitum energy intake under controlled conditions have been developed. Objective: Our objective was to evaluate the reproducibility of ad libitum energy intake with the use of a computerized vending machine system. Design: Twelve individuals (mean ± SD: 36 ± 8 y old; 41 ± 8% body fat) consumed a weight-maintaining diet for 3 d; subsequently, they self-selected all food with the use of a computerized vending machine system for an additional 3 d. Mean daily energy intake was calculated from the actual weight of foods consumed and expressed as a percentage of weight-maintenance energy needs (%WMEN). Subjects repeated the study multiple times during 2 y. The within-person reproducibility of energy intake was determined through the calculation of the intraclass correlation coefficients (ICCs) between visits. Results: Daily energy intake for all subjects was 5020 ± 1753 kcal during visit 1 and 4855 ± 1615 kcal during visit 2. There were no significant associations between energy intake and body weight, body mass index, or percentage body fat while subjects used the vending machines, which indicates that intake was not driven by body size or need. Despite overconsumption (%WMEN = 181 ± 57%), the reproducibility of intake between visits, whether expressed as daily energy intake (ICC = 0.90), %WMEN (ICC = 0.86), weight of food consumed (ICC = 0.87), or fat intake (g/d; ICC = 0.87), was highly significant (P < 0.0001). Conclusion: Although ad libitum energy intake exceeded %WMEN, the within-person reliability of this intake across multiple visits was high, which makes this a reproducible method for the measurement of ad libitum intake in subjects who reside in a research unit. This trial was registered at clinicaltrials.gov as NCT00342732. PMID:19923376

  13. Hawaii Electric System Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Loose, Verne William [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Silva Monroy, Cesar Augusto [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2012-08-01

    This report addresses Hawaii electric system reliability issues; greater emphasis is placed on short-term reliability but resource adequacy is reviewed in reference to electric consumers’ views of reliability “worth” and the reserve capacity required to deliver that value. The report begins with a description of the Hawaii electric system to the extent permitted by publicly available data. Electrical engineering literature in the area of electric reliability is researched and briefly reviewed. North American Electric Reliability Corporation standards and measures for generation and transmission are reviewed and identified as to their appropriateness for various portions of the electric grid and for application in Hawaii. Analysis of frequency data supplied by the State of Hawaii Public Utilities Commission is presented together with comparison and contrast of performance of each of the systems for two years, 2010 and 2011. Literature tracing the development of reliability economics is reviewed and referenced. A method is explained for integrating system cost with outage cost to determine the optimal resource adequacy given customers’ views of the value contributed by reliable electric supply. The report concludes with findings and recommendations for reliability in the State of Hawaii.

  14. Hawaii electric system reliability.

    Energy Technology Data Exchange (ETDEWEB)

    Silva Monroy, Cesar Augusto; Loose, Verne William

    2012-09-01

    This report addresses Hawaii electric system reliability issues; greater emphasis is placed on short-term reliability but resource adequacy is reviewed in reference to electric consumers' views of reliability %E2%80%9Cworth%E2%80%9D and the reserve capacity required to deliver that value. The report begins with a description of the Hawaii electric system to the extent permitted by publicly available data. Electrical engineering literature in the area of electric reliability is researched and briefly reviewed. North American Electric Reliability Corporation standards and measures for generation and transmission are reviewed and identified as to their appropriateness for various portions of the electric grid and for application in Hawaii. Analysis of frequency data supplied by the State of Hawaii Public Utilities Commission is presented together with comparison and contrast of performance of each of the systems for two years, 2010 and 2011. Literature tracing the development of reliability economics is reviewed and referenced. A method is explained for integrating system cost with outage cost to determine the optimal resource adequacy given customers' views of the value contributed by reliable electric supply. The report concludes with findings and recommendations for reliability in the State of Hawaii.

  15. Improving machinery reliability

    CERN Document Server

    Bloch, Heinz P

    1998-01-01

    This totally revised, updated and expanded edition provides proven techniques and procedures that extend machinery life, reduce maintenance costs, and achieve optimum machinery reliability. This essential text clearly describes the reliability improvement and failure avoidance steps practiced by best-of-class process plants in the U.S. and Europe.

  16. LED system reliability

    NARCIS (Netherlands)

    Driel, W.D. van; Yuan, C.A.; Koh, S.; Zhang, G.Q.

    2011-01-01

    This paper presents our effort to predict the system reliability of Solid State Lighting (SSL) applications. A SSL system is composed of a LED engine with micro-electronic driver(s) that supplies power to the optic design. Knowledge of system level reliability is not only a challenging scientific

  17. Integrated system reliability analysis

    DEFF Research Database (Denmark)

    Gintautas, Tomas; Sørensen, John Dalsgaard

    Specific targets: 1) The report shall describe the state of the art of reliability and risk-based assessment of wind turbine components. 2) Development of methodology for reliability and risk-based assessment of the wind turbine at system level. 3) Describe quantitative and qualitative measures...

  18. Reliability of neural encoding

    DEFF Research Database (Denmark)

    Alstrøm, Preben; Beierholm, Ulrik; Nielsen, Carsten Dahl

    2002-01-01

    The reliability with which a neuron is able to create the same firing pattern when presented with the same stimulus is of critical importance to the understanding of neuronal information processing. We show that reliability is closely related to the process of phaselocking. Experimental results f...

  19. Reproducibility of computer-aided detection system in digital mammograms

    International Nuclear Information System (INIS)

    Kim, Seung Ja; Cho, Nariya; Cha, Joo Hee; Chung, Hye Kyung; Lee, Sin Ho; Cho, Kyung Soo; Kim, Sun Mi; Moon, Woo Kyung

    2005-01-01

    To evaluate the reproducibility of the computer-aided detection (CAD) system for digital mammograms. We applied the CAD system (ImageChecker M1000-DM, version 3.1; R2 Technology) to full field digital mammograms. These mammograms were taken twice at an interval of 10-45 days (mean:25 days) for 34 preoperative patients (breast cancer n=27, benign disease n=7, age range:20-66 years, mean age:47.9 years). On the mammograms, lesions were visible in 19 patients and these were depicted as 15 masses and 12 calcification clusters. We analyzed the sensitivity, the false positive rate (FPR) and the reproducibility of the CAD marks. The broader sensitivities of the CAD system were 80% (12 of 15), 67%(10 of 15) for masses and those for calcification clusters were 100% (12 of 12). The strict sensitivities were 50% (15 of 30) and 50% (15 of 30) for masses and 92% (22 of 24) and 79% (19 of 24) for the clusters. The FPR for the masses was 0.21-0.22/image, the FPR for the clusters was 0.03-0.04/image and the total FPR was 0.24-0.26/image. Among 132 mammography images, the identical images regardless of the existence of CAD marks were 59% (78 of 132), and the identical images with CAD marks were 22% (15 of 69). The reproducibility of the CAD marks for the true positive mass was 67% (12 of 18) and 71% (17 of 24) for the true positive cluster. The reproducibility of CAD marks for the false positive mass was 8% (4 of 53), and the reproducibility of CAD marks for the false positive clusters was 14% (1 of 7). The reproducibility of the total mass marks was 23% (16 of 71), and the reproducibility of the total cluster marks was 58% (18 of 31). CAD system showed higher sensitivity and reproducibility of CAD marks for the calcification clusters which are related to breast cancer. Yet the overall reproducibility of CAD marks was low; therefore, the CAD system must be applied considering this limitation

  20. Using prediction markets to estimate the reproducibility of scientific research

    Science.gov (United States)

    Dreber, Anna; Pfeiffer, Thomas; Almenberg, Johan; Isaksson, Siri; Wilson, Brad; Chen, Yiling; Nosek, Brian A.; Johannesson, Magnus

    2015-01-01

    Concerns about a lack of reproducibility of statistically significant results have recently been raised in many fields, and it has been argued that this lack comes at substantial economic costs. We here report the results from prediction markets set up to quantify the reproducibility of 44 studies published in prominent psychology journals and replicated in the Reproducibility Project: Psychology. The prediction markets predict the outcomes of the replications well and outperform a survey of market participants’ individual forecasts. This shows that prediction markets are a promising tool for assessing the reproducibility of published scientific results. The prediction markets also allow us to estimate probabilities for the hypotheses being true at different testing stages, which provides valuable information regarding the temporal dynamics of scientific discovery. We find that the hypotheses being tested in psychology typically have low prior probabilities of being true (median, 9%) and that a “statistically significant” finding needs to be confirmed in a well-powered replication to have a high probability of being true. We argue that prediction markets could be used to obtain speedy information about reproducibility at low cost and could potentially even be used to determine which studies to replicate to optimally allocate limited resources into replications. PMID:26553988

  1. Validation and reproducibility of an Australian caffeine food frequency questionnaire.

    Science.gov (United States)

    Watson, E J; Kohler, M; Banks, S; Coates, A M

    2017-08-01

    The aim of this study was to measure validity and reproducibility of a caffeine food frequency questionnaire (C-FFQ) developed for the Australian population. The C-FFQ was designed to assess average daily caffeine consumption using four categories of food and beverages including; energy drinks; soft drinks/soda; coffee and tea and chocolate (food and drink). Participants completed a seven-day food diary immediately followed by the C-FFQ on two consecutive days. The questionnaire was first piloted in 20 adults, and then, a validity/reproducibility study was conducted (n = 90 adults). The C-FFQ showed moderate correlations (r = .60), fair agreement (mean difference 63 mg) and reasonable quintile rankings indicating fair to moderate agreement with the seven-day food diary. To test reproducibility, the C-FFQ was compared to itself and showed strong correlations (r = .90), good quintile rankings and strong kappa values (κ = 0.65), indicating strong reproducibility. The C-FFQ shows adequate validity and reproducibility and will aid researchers in Australia to quantify caffeine consumption.

  2. Using prediction markets to estimate the reproducibility of scientific research.

    Science.gov (United States)

    Dreber, Anna; Pfeiffer, Thomas; Almenberg, Johan; Isaksson, Siri; Wilson, Brad; Chen, Yiling; Nosek, Brian A; Johannesson, Magnus

    2015-12-15

    Concerns about a lack of reproducibility of statistically significant results have recently been raised in many fields, and it has been argued that this lack comes at substantial economic costs. We here report the results from prediction markets set up to quantify the reproducibility of 44 studies published in prominent psychology journals and replicated in the Reproducibility Project: Psychology. The prediction markets predict the outcomes of the replications well and outperform a survey of market participants' individual forecasts. This shows that prediction markets are a promising tool for assessing the reproducibility of published scientific results. The prediction markets also allow us to estimate probabilities for the hypotheses being true at different testing stages, which provides valuable information regarding the temporal dynamics of scientific discovery. We find that the hypotheses being tested in psychology typically have low prior probabilities of being true (median, 9%) and that a "statistically significant" finding needs to be confirmed in a well-powered replication to have a high probability of being true. We argue that prediction markets could be used to obtain speedy information about reproducibility at low cost and could potentially even be used to determine which studies to replicate to optimally allocate limited resources into replications.

  3. Design reliability engineering

    International Nuclear Information System (INIS)

    Buden, D.; Hunt, R.N.M.

    1989-01-01

    Improved design techniques are needed to achieve high reliability at minimum cost. This is especially true of space systems where lifetimes of many years without maintenance are needed and severe mass limitations exist. Reliability must be designed into these systems from the start. Techniques are now being explored to structure a formal design process that will be more complete and less expensive. The intent is to integrate the best features of design, reliability analysis, and expert systems to design highly reliable systems to meet stressing needs. Taken into account are the large uncertainties that exist in materials, design models, and fabrication techniques. Expert systems are a convenient method to integrate into the design process a complete definition of all elements that should be considered and an opportunity to integrate the design process with reliability, safety, test engineering, maintenance and operator training. 1 fig

  4. Bayesian methods in reliability

    Science.gov (United States)

    Sander, P.; Badoux, R.

    1991-11-01

    The present proceedings from a course on Bayesian methods in reliability encompasses Bayesian statistical methods and their computational implementation, models for analyzing censored data from nonrepairable systems, the traits of repairable systems and growth models, the use of expert judgment, and a review of the problem of forecasting software reliability. Specific issues addressed include the use of Bayesian methods to estimate the leak rate of a gas pipeline, approximate analyses under great prior uncertainty, reliability estimation techniques, and a nonhomogeneous Poisson process. Also addressed are the calibration sets and seed variables of expert judgment systems for risk assessment, experimental illustrations of the use of expert judgment for reliability testing, and analyses of the predictive quality of software-reliability growth models such as the Weibull order statistics.

  5. REPRODUCIBILITY AND EQUIVALENCE OF COBBMETER APPLICATION IN THE SAGITTAL EVALUATION OF THE SPINE

    Directory of Open Access Journals (Sweden)

    Luis Marchi

    Full Text Available ABSTRACT Objective: This study aims to evaluate the reliability and equivalency of using the Cobbmeter application for iPhone compared to the manual measurement method in the analysis of the sagittal spinal alignment. Methods: Cross-sectional, prospective, single-center study that had 20 panoramic radiographs of the spine in lateral view, in a neutral standing position, analyzed blindly and randomly by three independent examiners in three different times. The parameters were pelvic incidence (PI, pelvic tilt (PT and lumbar lordosis (LL. The statistical analysis was performed to measure the intraclass correlation coefficient (ICC between the two measurement methods, in addition to measuring the intra and inter-evaluators reliability. Results: For reproducibility analysis, the intra-evaluators ICC using the application resulted in a Kappa (K of 0.975 for the evaluation of pelvic incidence (PI evaluation. For pelvic tilt (PT, the K value obtained was 0.981 and the K measured for lumbar lordosis (LL analysis was 0.987. The inter-evaluators evaluation of reproducibility using the application resulted in a K value of 0.917 for PI, 0.930 for PT and 0.951 for LL. For the assessment of equivalency of methods, comparing the application to the standard method, with a goniometer and dermographic pencil, the K value found for PI was 0.873, for PV was 0.939 and for LL was 0.914. All values were significant (p<0.001 against the null hypothesis. Conclusion: This smartphone application is a valid and reliable instrument for measuring the angle involved in the sagittal balance of the spine. Furthermore, the results show that its applicability is not inferior to the manual method with goniometer and dermographic pencil.

  6. The quest for improved reproducibility in MALDI mass spectrometry.

    Science.gov (United States)

    O'Rourke, Matthew B; Djordjevic, Steven P; Padula, Matthew P

    2018-03-01

    Reproducibility has been one of the biggest hurdles faced when attempting to develop quantitative protocols for MALDI mass spectrometry. The heterogeneous nature of sample recrystallization has made automated sample acquisition somewhat "hit and miss" with manual intervention needed to ensure that all sample spots have been analyzed. In this review, we explore the last 30 years of literature and anecdotal evidence that has attempted to address and improve reproducibility in MALDI MS. Though many methods have been attempted, we have discovered a significant publication history surrounding the use of nitrocellulose as a substrate to improve homogeneity of crystal formation and therefore reproducibility. We therefore propose that this is the most promising avenue of research for developing a comprehensive and universal preparation protocol for quantitative MALDI MS analysis. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 37:217-228, 2018. © 2016 Wiley Periodicals, Inc.

  7. Dysplastic naevus: histological criteria and their inter-observer reproducibility.

    Science.gov (United States)

    Hastrup, N; Clemmensen, O J; Spaun, E; Søndergaard, K

    1994-06-01

    Forty melanocytic lesions were examined in a pilot study, which was followed by a final series of 100 consecutive melanocytic lesions, in order to evaluate the inter-observer reproducibility of the histological criteria proposed for the dysplastic naevus. The specimens were examined in a blind fashion by four observers. Analysis by kappa statistics showed poor reproducibility of nuclear features, while reproducibility of architectural features was acceptable, improving in the final series. Consequently, we cannot apply the combined criteria of cytological and architectural features with any confidence in the diagnosis of dysplastic naevus, and, until further studies have documented that architectural criteria alone will suffice in the diagnosis of dysplastic naevus, we, as pathologists, shall avoid this term.

  8. Relevant principal factors affecting the reproducibility of insect primary culture.

    Science.gov (United States)

    Ogata, Norichika; Iwabuchi, Kikuo

    2017-06-01

    The primary culture of insect cells often suffers from problems with poor reproducibility in the quality of the final cell preparations. The cellular composition of the explants (cell number and cell types), surgical methods (surgical duration and surgical isolation), and physiological and genetic differences between donors may be critical factors affecting the reproducibility of culture. However, little is known about where biological variation (interindividual differences between donors) ends and technical variation (variance in replication of culture conditions) begins. In this study, we cultured larval fat bodies from the Japanese rhinoceros beetle, Allomyrina dichotoma, and evaluated, using linear mixed models, the effect of interindividual variation between donors on the reproducibility of the culture. We also performed transcriptome analysis of the hemocyte-like cells mainly seen in the cultures using RNA sequencing and ultrastructural analyses of hemocytes using a transmission electron microscope, revealing that the cultured cells have many characteristics of insect hemocytes.

  9. Reproducibility of clinical research in critical care: a scoping review.

    Science.gov (United States)

    Niven, Daniel J; McCormick, T Jared; Straus, Sharon E; Hemmelgarn, Brenda R; Jeffs, Lianne; Barnes, Tavish R M; Stelfox, Henry T

    2018-02-21

    The ability to reproduce experiments is a defining principle of science. Reproducibility of clinical research has received relatively little scientific attention. However, it is important as it may inform clinical practice, research agendas, and the design of future studies. We used scoping review methods to examine reproducibility within a cohort of randomized trials examining clinical critical care research and published in the top general medical and critical care journals. To identify relevant clinical practices, we searched the New England Journal of Medicine, The Lancet, and JAMA for randomized trials published up to April 2016. To identify a comprehensive set of studies for these practices, included articles informed secondary searches within other high-impact medical and specialty journals. We included late-phase randomized controlled trials examining therapeutic clinical practices in adults admitted to general medical-surgical or specialty intensive care units (ICUs). Included articles were classified using a reproducibility framework. An original study was the first to evaluate a clinical practice. A reproduction attempt re-evaluated that practice in a new set of participants. Overall, 158 practices were examined in 275 included articles. A reproduction attempt was identified for 66 practices (42%, 95% CI 33-50%). Original studies reported larger effects than reproduction attempts (primary endpoint, risk difference 16.0%, 95% CI 11.6-20.5% vs. 8.4%, 95% CI 6.0-10.8%, P = 0.003). More than half of clinical practices with a reproduction attempt demonstrated effects that were inconsistent with the original study (56%, 95% CI 42-68%), among which a large number were reported to be efficacious in the original study and to lack efficacy in the reproduction attempt (34%, 95% CI 19-52%). Two practices reported to be efficacious in the original study were found to be harmful in the reproduction attempt. A minority of critical care practices with research published

  10. Effective Form of Reproducing the Total Financial Potential of Ukraine

    Directory of Open Access Journals (Sweden)

    Portna Oksana V.

    2015-03-01

    Full Text Available Development of scientific principles of reproducing the total financial potential of the country and its effective form is an urgent problem both in theoretical and practical aspects of the study, the solution of which is intended to ensure the active mobilization and effective use of the total financial potential of Ukraine, and as a result — its expanded reproduction as well, which would contribute to realization of the internal capacities for stabilization of the national economy. The purpose of the article is disclosing the essence of the effective form of reproducing the total financial potential of the country, analyzing the results of reproducing the total financial potential of Ukraine. It has been proved that the basis for the effective form of reproducing the total financial potential of the country is the volume and flow of resources, which are associated with the «real» economy, affect the dynamics of GDP and define it, i.e. resource and process forms of reproducing the total financial potential of Ukraine (which precede the effective one. The analysis of reproducing the total financial potential of Ukraine has shown that in the analyzed period there was an increase in the financial possibilities of the country, but steady dynamics of reduction of the total financial potential was observed. If we consider the amount of resources involved in production, creating a net value added and GDP, it occurs on a restricted basis. Growth of the total financial potential of Ukraine is connected only with extensive quantitative factors rather than intensive qualitative changes.

  11. The MIMIC Code Repository: enabling reproducibility in critical care research.

    Science.gov (United States)

    Johnson, Alistair Ew; Stone, David J; Celi, Leo A; Pollard, Tom J

    2018-01-01

    Lack of reproducibility in medical studies is a barrier to the generation of a robust knowledge base to support clinical decision-making. In this paper we outline the Medical Information Mart for Intensive Care (MIMIC) Code Repository, a centralized code base for generating reproducible studies on an openly available critical care dataset. Code is provided to load the data into a relational structure, create extractions of the data, and reproduce entire analysis plans including research studies. Concepts extracted include severity of illness scores, comorbid status, administrative definitions of sepsis, physiologic criteria for sepsis, organ failure scores, treatment administration, and more. Executable documents are used for tutorials and reproduce published studies end-to-end, providing a template for future researchers to replicate. The repository's issue tracker enables community discussion about the data and concepts, allowing users to collaboratively improve the resource. The centralized repository provides a platform for users of the data to interact directly with the data generators, facilitating greater understanding of the data. It also provides a location for the community to collaborate on necessary concepts for research progress and share them with a larger audience. Consistent application of the same code for underlying concepts is a key step in ensuring that research studies on the MIMIC database are comparable and reproducible. By providing open source code alongside the freely accessible MIMIC-III database, we enable end-to-end reproducible analysis of electronic health records. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association.

  12. Language-Agnostic Reproducible Data Analysis Using Literate Programming.

    Science.gov (United States)

    Vassilev, Boris; Louhimo, Riku; Ikonen, Elina; Hautaniemi, Sampsa

    2016-01-01

    A modern biomedical research project can easily contain hundreds of analysis steps and lack of reproducibility of the analyses has been recognized as a severe issue. While thorough documentation enables reproducibility, the number of analysis programs used can be so large that in reality reproducibility cannot be easily achieved. Literate programming is an approach to present computer programs to human readers. The code is rearranged to follow the logic of the program, and to explain that logic in a natural language. The code executed by the computer is extracted from the literate source code. As such, literate programming is an ideal formalism for systematizing analysis steps in biomedical research. We have developed the reproducible computing tool Lir (literate, reproducible computing) that allows a tool-agnostic approach to biomedical data analysis. We demonstrate the utility of Lir by applying it to a case study. Our aim was to investigate the role of endosomal trafficking regulators to the progression of breast cancer. In this analysis, a variety of tools were combined to interpret the available data: a relational database, standard command-line tools, and a statistical computing environment. The analysis revealed that the lipid transport related genes LAPTM4B and NDRG1 are coamplified in breast cancer patients, and identified genes potentially cooperating with LAPTM4B in breast cancer progression. Our case study demonstrates that with Lir, an array of tools can be combined in the same data analysis to improve efficiency, reproducibility, and ease of understanding. Lir is an open-source software available at github.com/borisvassilev/lir.

  13. Reproducibility problems of in-service ultrasonic testing results

    International Nuclear Information System (INIS)

    Honcu, E.

    1974-01-01

    The reproducibility of the results of ultrasonic testing is the basic precondition for its successful application in in-service inspection of changes in the quality of components of nuclear power installations. The results of periodic ultrasonic inspections are not satisfactory from the point of view of reproducibility. Regardless, the ultrasonic pulse-type method is suitable for evaluating the quality of most components of nuclear installations and often the sole method which may be recommended for inspection with regard to its technical and economic aspects. (J.B.)

  14. Reproducibility of esophageal scintigraphy using semi-solid yoghurt

    Energy Technology Data Exchange (ETDEWEB)

    Imai, Yukinori; Kinoshita, Manabu; Asakura, Yasushi; Kakinuma, Tohru; Shimoji, Katsunori; Fujiwara, Kenji; Suzuki, Kenji; Miyamae, Tatsuya [Saitama Medical School, Moroyama (Japan)

    1999-10-01

    Esophageal scintigraphy is a non-invasive method which evaluate esophageal function quantitatively. We applied new technique using semi-solid yoghurt, which can evaluate esophageal function in a sitting position. To evaluate the reproducibility of this method, scintigraphy were performed in 16 healthy volunteers. From the result of four swallows except the first one, the mean coefficients of variation in esophageal transit time and esophageal emptying time were 12.8% and 13.4% respectively (interday variation). As regards the interday variation, this method had also good reproducibility from the result on the 2 separate days. (author)

  15. Reproducing Kernel Method for Solving Nonlinear Differential-Difference Equations

    Directory of Open Access Journals (Sweden)

    Reza Mokhtari

    2012-01-01

    Full Text Available On the basis of reproducing kernel Hilbert spaces theory, an iterative algorithm for solving some nonlinear differential-difference equations (NDDEs is presented. The analytical solution is shown in a series form in a reproducing kernel space, and the approximate solution , is constructed by truncating the series to terms. The convergence of , to the analytical solution is also proved. Results obtained by the proposed method imply that it can be considered as a simple and accurate method for solving such differential-difference problems.

  16. Reliable dynamics in Boolean and continuous networks

    International Nuclear Information System (INIS)

    Ackermann, Eva; Drossel, Barbara; Peixoto, Tiago P

    2012-01-01

    We investigate the dynamical behavior of a model of robust gene regulatory networks which possess ‘entirely reliable’ trajectories. In a Boolean representation, these trajectories are characterized by being insensitive to the order in which the nodes are updated, i.e. they always go through the same sequence of states. The Boolean model for gene activity is compared with a continuous description in terms of differential equations for the concentrations of mRNA and proteins. We found that entirely reliable Boolean trajectories can be reproduced perfectly in the continuous model when realistic Hill coefficients are used. We investigate to what extent this high correspondence between Boolean and continuous trajectories depends on the extent of reliability of the Boolean trajectories, and we identify simple criteria that enable the faithful reproduction of the Boolean dynamics in the continuous description. (paper)

  17. Reliability of construction materials

    International Nuclear Information System (INIS)

    Merz, H.

    1976-01-01

    One can also speak of reliability with respect to materials. While for reliability of components the MTBF (mean time between failures) is regarded as the main criterium, this is replaced with regard to materials by possible failure mechanisms like physical/chemical reaction mechanisms, disturbances of physical or chemical equilibrium, or other interactions or changes of system. The main tasks of the reliability analysis of materials therefore is the prediction of the various failure reasons, the identification of interactions, and the development of nondestructive testing methods. (RW) [de

  18. Structural Reliability Methods

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Madsen, H. O.

    The structural reliability methods quantitatively treat the uncertainty of predicting the behaviour and properties of a structure given the uncertain properties of its geometry, materials, and the actions it is supposed to withstand. This book addresses the probabilistic methods for evaluation...... of structural reliability, including the theoretical basis for these methods. Partial safety factor codes under current practice are briefly introduced and discussed. A probabilistic code format for obtaining a formal reliability evaluation system that catches the most essential features of the nature...... of the uncertainties and their interplay is the developed, step-by-step. The concepts presented are illustrated by numerous examples throughout the text....

  19. Reliability and mechanical design

    International Nuclear Information System (INIS)

    Lemaire, Maurice

    1997-01-01

    A lot of results in mechanical design are obtained from a modelisation of physical reality and from a numerical solution which would lead to the evaluation of needs and resources. The goal of the reliability analysis is to evaluate the confidence which it is possible to grant to the chosen design through the calculation of a probability of failure linked to the retained scenario. Two types of analysis are proposed: the sensitivity analysis and the reliability analysis. Approximate methods are applicable to problems related to reliability, availability, maintainability and safety (RAMS)

  20. RTE - 2013 Reliability Report

    International Nuclear Information System (INIS)

    Denis, Anne-Marie

    2014-01-01

    RTE publishes a yearly reliability report based on a standard model to facilitate comparisons and highlight long-term trends. The 2013 report is not only stating the facts of the Significant System Events (ESS), but it moreover underlines the main elements dealing with the reliability of the electrical power system. It highlights the various elements which contribute to present and future reliability and provides an overview of the interaction between the various stakeholders of the Electrical Power System on the scale of the European Interconnected Network. (author)

  1. Reproducibility and day time bias correction of optoelectronic leg volumetry: a prospective cohort study.

    Science.gov (United States)

    Engelberger, Rolf P; Blazek, Claudia; Amsler, Felix; Keo, Hong H; Baumann, Frédéric; Blättler, Werner; Baumgartner, Iris; Willenberg, Torsten

    2011-10-05

    Leg edema is a common manifestation of various underlying pathologies. Reliable measurement tools are required to quantify edema and monitor therapeutic interventions. Aim of the present work was to investigate the reproducibility of optoelectronic leg volumetry over 3 weeks' time period and to eliminate daytime related within-individual variability. Optoelectronic leg volumetry was performed in 63 hairdressers (mean age 45 ± 16 years, 85.7% female) in standing position twice within a minute for each leg and repeated after 3 weeks. Both lower leg (legBD) and whole limb (limbBF) volumetry were analysed. Reproducibility was expressed as analytical and within-individual coefficients of variance (CVA, CVW), and as intra-class correlation coefficients (ICC). A total of 492 leg volume measurements were analysed. Both legBD and limbBF volumetry were highly reproducible with CVA of 0.5% and 0.7%, respectively. Within-individual reproducibility of legBD and limbBF volumetry over a three weeks' period was high (CVW 1.3% for both; ICC 0.99 for both). At both visits, the second measurement revealed a significantly higher volume compared to the first measurement with a mean increase of 7.3 ml ± 14.1 (0.33% ± 0.58%) for legBD and 30.1 ml ± 48.5 ml (0.52% ± 0.79%) for limbBF volume. A significant linear correlation between absolute and relative leg volume differences and the difference of exact day time of measurement between the two study visits was found (P correction formula permitted further improvement of CVW. Leg volume changes can be reliably assessed by optoelectronic leg volumetry at a single time point and over a 3 weeks' time period. However, volumetry results are biased by orthostatic and daytime-related volume changes. The bias for day-time related volume changes can be minimized by a time-correction formula.

  2. Reproducibility and day time bias correction of optoelectronic leg volumetry: a prospective cohort study

    Directory of Open Access Journals (Sweden)

    Baumgartner Iris

    2011-10-01

    Full Text Available Abstract Background Leg edema is a common manifestation of various underlying pathologies. Reliable measurement tools are required to quantify edema and monitor therapeutic interventions. Aim of the present work was to investigate the reproducibility of optoelectronic leg volumetry over 3 weeks' time period and to eliminate daytime related within-individual variability. Methods Optoelectronic leg volumetry was performed in 63 hairdressers (mean age 45 ± 16 years, 85.7% female in standing position twice within a minute for each leg and repeated after 3 weeks. Both lower leg (legBD and whole limb (limbBF volumetry were analysed. Reproducibility was expressed as analytical and within-individual coefficients of variance (CVA, CVW, and as intra-class correlation coefficients (ICC. Results A total of 492 leg volume measurements were analysed. Both legBD and limbBF volumetry were highly reproducible with CVA of 0.5% and 0.7%, respectively. Within-individual reproducibility of legBD and limbBF volumetry over a three weeks' period was high (CVW 1.3% for both; ICC 0.99 for both. At both visits, the second measurement revealed a significantly higher volume compared to the first measurement with a mean increase of 7.3 ml ± 14.1 (0.33% ± 0.58% for legBD and 30.1 ml ± 48.5 ml (0.52% ± 0.79% for limbBF volume. A significant linear correlation between absolute and relative leg volume differences and the difference of exact day time of measurement between the two study visits was found (P W. Conclusions Leg volume changes can be reliably assessed by optoelectronic leg volumetry at a single time point and over a 3 weeks' time period. However, volumetry results are biased by orthostatic and daytime-related volume changes. The bias for day-time related volume changes can be minimized by a time-correction formula.

  3. Approach to reliability assessment

    International Nuclear Information System (INIS)

    Green, A.E.; Bourne, A.J.

    1975-01-01

    Experience has shown that reliability assessments can play an important role in the early design and subsequent operation of technological systems where reliability is at a premium. The approaches to and techniques for such assessments, which have been outlined in the paper, have been successfully applied in variety of applications ranging from individual equipments to large and complex systems. The general approach involves the logical and systematic establishment of the purpose, performance requirements and reliability criteria of systems. This is followed by an appraisal of likely system achievment based on the understanding of different types of variational behavior. A fundamental reliability model emerges from the correlation between the appropriate Q and H functions for performance requirement and achievement. This model may cover the complete spectrum of performance behavior in all the system dimensions

  4. Reproducibility and clinical utility of tendon palpation to detect patellar tendinopathy in young basketball players

    Science.gov (United States)

    Cook, J; Khan, K; Kiss, Z; Purdam, C; Griffiths, L

    2001-01-01

    Background—Palpation is an important clinical test for jumper's knee. Objectives—To (a) test the reproducibility of palpation tenderness, (b) evaluate the sensitivity and specificity of palpation in subjects with clinical symptoms of jumper's knee, and (c) determine whether tenderness to palpation may serve as a useful screening test for patellar tendinopathy. The yardstick for diagnosis of patellar tendinopathy was ultrasonographic abnormality. Methods—In 326 junior symptomatic and asymptomatic athletes' tendons, palpation was performed by a single examiner before ultrasonographic examination by a certified ultrasound radiologist. In 58 tendons, palpation was performed twice to test reliability. Tenderness to palpation was scored on a scale from 0 to 3 where 0 represented no pain, and 1, 2, and 3 represented mild, moderate, and severe tenderness respectively. Results—Patellar tendon palpation was a reliable examination for a single examiner (Pearson r = 0.82). In symptomatic tendons, the positive predictive value of palpation was 68%. As a screening examination in asymptomatic subjects, the positive predictive value of tendon palpation was 36–38%. Moderate and severe palpation tenderness were better predictors of ultrasonographic tendon pathology than absent or mild tenderness (ppatellar tendinopathy in a preparticipation examination. In symptomatic tendons, palpation is a moderately sensitive but not specific test. Mild tenderness in the patellar tendons in asymptomatic jumping athletes should be considered normal. Key Words: patellar tendon; ultrasound; palpation; reliability; athletes PMID:11157466

  5. Reproducible and expedient rice regeneration system using in vitro ...

    African Journals Online (AJOL)

    Inevitable prerequisite for expedient regeneration in rice is the selection of totipotent explant and developing an apposite combination of growth hormones. Here, we reported a reproducible regeneration protocol in which basal segments of the stem of the in vitro grown rice plants were used as ex-plant. Using the protocol ...

  6. Composting in small laboratory pilots: Performance and reproducibility

    International Nuclear Information System (INIS)

    Lashermes, G.; Barriuso, E.; Le Villio-Poitrenaud, M.; Houot, S.

    2012-01-01

    Highlights: ► We design an innovative small-scale composting device including six 4-l reactors. ► We investigate the performance and reproducibility of composting on a small scale. ► Thermophilic conditions are established by self-heating in all replicates. ► Biochemical transformations, organic matter losses and stabilisation are realistic. ► The organic matter evolution exhibits good reproducibility for all six replicates. - Abstract: Small-scale reactors ( 2 consumption and CO 2 emissions, and characterising the biochemical evolution of organic matter. A good reproducibility was found for the six replicates with coefficients of variation for all parameters generally lower than 19%. An intense self-heating ensured the existence of a spontaneous thermophilic phase in all reactors. The average loss of total organic matter (TOM) was 46% of the initial content. Compared to the initial mixture, the hot water soluble fraction decreased by 62%, the hemicellulose-like fraction by 68%, the cellulose-like fraction by 50% and the lignin-like fractions by 12% in the final compost. The TOM losses, compost stabilisation and evolution of the biochemical fractions were similar to observed in large reactors or on-site experiments, excluding the lignin degradation, which was less important than in full-scale systems. The reproducibility of the process and the quality of the final compost make it possible to propose the use of this experimental device for research requiring a mass reduction of the initial composted waste mixtures.

  7. Intercenter reproducibility of binary typing for Staphylococcus aureus

    NARCIS (Netherlands)

    van Leeuwen, Willem B.; Snoeijers, Sandor; van der Werken-Libregts, Christel; Tuip, Anita; van der Zee, Anneke; Egberink, Diane; de Proost, Monique; Bik, Elisabeth; Lunter, Bjorn; Kluytmans, Jan; Gits, Etty; van Duyn, Inge; Heck, Max; van der Zwaluw, Kim; Wannet, Wim; Noordhoek, Gerda T.; Mulder, Sije; Renders, Nicole; Boers, Miranda; Zaat, Sebastiaan; van der Riet, Daniëlle; Kooistra, Mirjam; Talens, Adriaan; Dijkshoorn, Lenie; van der Reyden, Tanny; Veenendaal, Dick; Bakker, Nancy; Cookson, Barry; Lynch, Alisson; Witte, Wolfgang; Cuny, Christa; Blanc, Dominique; Vernez, Isabelle; Hryniewicz, Waleria; Fiett, Janusz; Struelens, Marc; Deplano, Ariane; Landegent, Jim; Verbrugh, Henri A.; van Belkum, Alex

    2002-01-01

    The reproducibility of the binary typing (BT) protocol developed for epidemiological typing of Staphylococcus aureus was analyzed in a biphasic multicenter study. In a Dutch multicenter pilot study, 10 genetically unique isolates of methicillin-resistant S. aureus (MRSA) were characterized by the BT

  8. Reproducibility of Tactile Assessments for Children with Unilateral Cerebral Palsy

    Science.gov (United States)

    Auld, Megan Louise; Ware, Robert S.; Boyd, Roslyn Nancy; Moseley, G. Lorimer; Johnston, Leanne Marie

    2012-01-01

    A systematic review identified tactile assessments used in children with cerebral palsy (CP), but their reproducibility is unknown. Sixteen children with unilateral CP and 31 typically developing children (TDC) were assessed 2-4 weeks apart. Test-retest percent agreements within one point for children with unilateral CP (and TDC) were…

  9. ReproPhylo: An Environment for Reproducible Phylogenomics.

    Directory of Open Access Journals (Sweden)

    Amir Szitenberg

    2015-09-01

    Full Text Available The reproducibility of experiments is key to the scientific process, and particularly necessary for accurate reporting of analyses in data-rich fields such as phylogenomics. We present ReproPhylo, a phylogenomic analysis environment developed to ensure experimental reproducibility, to facilitate the handling of large-scale data, and to assist methodological experimentation. Reproducibility, and instantaneous repeatability, is built in to the ReproPhylo system and does not require user intervention or configuration because it stores the experimental workflow as a single, serialized Python object containing explicit provenance and environment information. This 'single file' approach ensures the persistence of provenance across iterations of the analysis, with changes automatically managed by the version control program Git. This file, along with a Git repository, are the primary reproducibility outputs of the program. In addition, ReproPhylo produces an extensive human-readable report and generates a comprehensive experimental archive file, both of which are suitable for submission with publications. The system facilitates thorough experimental exploration of both parameters and data. ReproPhylo is a platform independent CC0 Python module and is easily installed as a Docker image or a WinPython self-sufficient package, with a Jupyter Notebook GUI, or as a slimmer version in a Galaxy distribution.

  10. An empirical analysis of journal policy effectiveness for computational reproducibility.

    Science.gov (United States)

    Stodden, Victoria; Seiler, Jennifer; Ma, Zhaokun

    2018-03-13

    A key component of scientific communication is sufficient information for other researchers in the field to reproduce published findings. For computational and data-enabled research, this has often been interpreted to mean making available the raw data from which results were generated, the computer code that generated the findings, and any additional information needed such as workflows and input parameters. Many journals are revising author guidelines to include data and code availability. This work evaluates the effectiveness of journal policy that requires the data and code necessary for reproducibility be made available postpublication by the authors upon request. We assess the effectiveness of such a policy by ( i ) requesting data and code from authors and ( ii ) attempting replication of the published findings. We chose a random sample of 204 scientific papers published in the journal Science after the implementation of their policy in February 2011. We found that we were able to obtain artifacts from 44% of our sample and were able to reproduce the findings for 26%. We find this policy-author remission of data and code postpublication upon request-an improvement over no policy, but currently insufficient for reproducibility.

  11. Reproducibility of contrast-enhanced transrectal ultrasound of the prostate

    NARCIS (Netherlands)

    Sedelaar, J. P.; Goossen, T. E.; Wijkstra, H.; de la Rosette, J. J.

    2001-01-01

    Transrectal three-dimensional (3-D) contrast-enhanced power Doppler ultrasound (US) is a novel technique for studying possible prostate malignancy. Before studies can be performed to investigate the clinical validity of the technique, reproducibility of the contrast US studies must be proven.

  12. Reproducibility in the assessment of acute pancreatitis with computed tomography

    International Nuclear Information System (INIS)

    Freire Filho, Edison de Oliveira; Vieira, Renata La Rocca; Yamada, Andre Fukunishi; Shigueoka, David Carlos; Bekhor, Daniel; Freire, Maxime Figueiredo de Oliveira; Ajzen, Sergio; D'Ippolito, Giuseppe

    2007-01-01

    Objective: To evaluate the reproducibility of unenhanced and contrast-enhanced computed tomography in the assessment of patients with acute pancreatitis. Materials and methods: Fifty-one unenhanced and contrast-enhanced abdominal computed tomography studies of patients with acute pancreatitis were blindly reviewed by two radiologists (observers 1 and 2). The morphological index was separately calculated for unenhanced and contrast-enhanced computed tomography and the disease severity index was established. Intraobserver and interobserver reproducibility of computed tomography was measured by means of the kappa index (κ). Results: Interobserver agreement was κ 0.666, 0.705, 0.648, 0.547 and 0.631, respectively for unenhanced and contrast-enhanced morphological index, presence of pancreatic necrosis, pancreatic necrosis extension, and disease severity index. Intraobserver agreement (observers 1 and 2, respectively) was κ = 0.796 and 0.732 for unenhanced morphological index; κ 0.725 and 0.802 for contrast- enhanced morphological index; κ = 0.674 and 0.849 for presence of pancreatic necrosis; κ = 0.606 and 0.770 for pancreatic necrosis extension; and κ = 0.801 and 0.687 for disease severity index at computed tomography. Conclusion: Computed tomography for determination of morphological index and disease severity index in the staging of acute pancreatitis is a quite reproducible method. The absence of contrast- enhancement does not affect the computed tomography morphological index reproducibility. (author)

  13. Reproducible positioning in chest X-ray radiography

    International Nuclear Information System (INIS)

    1974-01-01

    A device is described that can be used to ensure reproducibility in the positioning of the patient during X-ray radiography of the thorax. Signals are taken from an electrocardiographic monitor and from a device recording the respiratory cycle. Radiography is performed only when two preselected signals coincide

  14. Reproducibility of Manual Platelet Estimation Following Automated Low Platelet Counts

    Directory of Open Access Journals (Sweden)

    Zainab S Al-Hosni

    2016-11-01

    Full Text Available Objectives: Manual platelet estimation is one of the methods used when automated platelet estimates are very low. However, the reproducibility of manual platelet estimation has not been adequately studied. We sought to assess the reproducibility of manual platelet estimation following automated low platelet counts and to evaluate the impact of the level of experience of the person counting on the reproducibility of manual platelet estimates. Methods: In this cross-sectional study, peripheral blood films of patients with platelet counts less than 100 × 109/L were retrieved and given to four raters to perform manual platelet estimation independently using a predefined method (average of platelet counts in 10 fields using 100× objective multiplied by 20. Data were analyzed using intraclass correlation coefficient (ICC as a method of reproducibility assessment. Results: The ICC across the four raters was 0.840, indicating excellent agreement. The median difference of the two most experienced raters was 0 (range: -64 to 78. The level of platelet estimate by the least-experienced rater predicted the disagreement (p = 0.037. When assessing the difference between pairs of raters, there was no significant difference in the ICC (p = 0.420. Conclusions: The agreement between different raters using manual platelet estimation was excellent. Further confirmation is necessary, with a prospective study using a gold standard method of platelet counts.

  15. Reproducibility of Quantitative Structural and Physiological MRI Measurements

    Science.gov (United States)

    2017-08-09

    project.org/) and SPSS (IBM Corp., Armonk, NY) for data analysis. Mean and confidence inter- vals for each measure are found in Tables 1–7. To assess...visits, and was calculated using a two- way mixed model in SPSS MCV and MRD values closer to 0 are considered to be the most reproducible, and ICC

  16. High Reproducibility of ELISPOT Counts from Nine Different Laboratories

    DEFF Research Database (Denmark)

    Sundararaman, Srividya; Karulin, Alexey Y; Ansari, Tameem

    2015-01-01

    The primary goal of immune monitoring with ELISPOT is to measure the number of T cells, specific for any antigen, accurately and reproducibly between different laboratories. In ELISPOT assays, antigen-specific T cells secrete cytokines, forming spots of different sizes on a membrane with variable...

  17. Reproducibility of the Pleth Variability Index in premature infants

    NARCIS (Netherlands)

    Den Boogert, W.J. (Wilhelmina J.); H.A. van Elteren (Hugo); T.G. Goos (Tom); I.K.M. Reiss (Irwin); R.C.J. de Jonge (Rogier); V.J. van den Berg (Victor J.)

    2017-01-01

    textabstractThe aim was to assess the reproducibility of the Pleth Variability Index (PVI), developed for non-invasive monitoring of peripheral perfusion, in preterm neonates below 32 weeks of gestational age. Three PVI measurements were consecutively performed in stable, comfortable preterm

  18. Reproducibility of the Pleth Variability Index in premature infants

    NARCIS (Netherlands)

    Den Boogert, Wilhelmina J.; Van Elteren, Hugo A.; Goos, T.G.; Reiss, Irwin K.M.; De Jonge, Rogier C.J.; van Den Berg, Victor J.

    2017-01-01

    The aim was to assess the reproducibility of the Pleth Variability Index (PVI), developed for non-invasive monitoring of peripheral perfusion, in preterm neonates below 32 weeks of gestational age. Three PVI measurements were consecutively performed in stable, comfortable preterm neonates in the

  19. Annotating with Propp's Morphology of the Folktale: Reproducibility and Trainability

    NARCIS (Netherlands)

    Fisseni, B.; Kurji, A.; Löwe, B.

    2014-01-01

    We continue the study of the reproducibility of Propp’s annotations from Bod et al. (2012). We present four experiments in which test subjects were taught Propp’s annotation system; we conclude that Propp’s system needs a significant amount of training, but that with sufficient time investment, it

  20. Exploring the Coming Repositories of Reproducible Experiments: Challenges and Opportunities

    DEFF Research Database (Denmark)

    Freire, Juliana; Bonnet, Philippe; Shasha, Dennis

    2011-01-01

    Computational reproducibility efforts in many communities will soon give rise to validated software and data repositories of high quality. A scientist in a field may want to query the components of such repositories to build new software workflows, perhaps after adding the scientist’s own algorithms...

  1. The rating reliability calculator

    Directory of Open Access Journals (Sweden)

    Solomon David J

    2004-04-01

    Full Text Available Abstract Background Rating scales form an important means of gathering evaluation data. Since important decisions are often based on these evaluations, determining the reliability of rating data can be critical. Most commonly used methods of estimating reliability require a complete set of ratings i.e. every subject being rated must be rated by each judge. Over fifty years ago Ebel described an algorithm for estimating the reliability of ratings based on incomplete data. While his article has been widely cited over the years, software based on the algorithm is not readily available. This paper describes an easy-to-use Web-based utility for estimating the reliability of ratings based on incomplete data using Ebel's algorithm. Methods The program is available public use on our server and the source code is freely available under GNU General Public License. The utility is written in PHP, a common open source imbedded scripting language. The rating data can be entered in a convenient format on the user's personal computer that the program will upload to the server for calculating the reliability and other statistics describing the ratings. Results When the program is run it displays the reliability, number of subject rated, harmonic mean number of judges rating each subject, the mean and standard deviation of the averaged ratings per subject. The program also displays the mean, standard deviation and number of ratings for each subject rated. Additionally the program will estimate the reliability of an average of a number of ratings for each subject via the Spearman-Brown prophecy formula. Conclusion This simple web-based program provides a convenient means of estimating the reliability of rating data without the need to conduct special studies in order to provide complete rating data. I would welcome other researchers revising and enhancing the program.

  2. Structural systems reliability analysis

    International Nuclear Information System (INIS)

    Frangopol, D.

    1975-01-01

    For an exact evaluation of the reliability of a structure it appears necessary to determine the distribution densities of the loads and resistances and to calculate the correlation coefficients between loads and between resistances. These statistical characteristics can be obtained only on the basis of a long activity period. In case that such studies are missing the statistical properties formulated here give upper and lower bounds of the reliability. (orig./HP) [de

  3. Reliability and maintainability

    International Nuclear Information System (INIS)

    1994-01-01

    Several communications in this conference are concerned with nuclear plant reliability and maintainability; their titles are: maintenance optimization of stand-by Diesels of 900 MW nuclear power plants; CLAIRE: an event-based simulation tool for software testing; reliability as one important issue within the periodic safety review of nuclear power plants; design of nuclear building ventilation by the means of functional analysis; operation characteristic analysis for a power industry plant park, as a function of influence parameters

  4. Reliability data book

    International Nuclear Information System (INIS)

    Bento, J.P.; Boerje, S.; Ericsson, G.; Hasler, A.; Lyden, C.O.; Wallin, L.; Poern, K.; Aakerlund, O.

    1985-01-01

    The main objective for the report is to improve failure data for reliability calculations as parts of safety analyses for Swedish nuclear power plants. The work is based primarily on evaluations of failure reports as well as information provided by the operation and maintenance staff of each plant. In the report are presented charts of reliability data for: pumps, valves, control rods/rod drives, electrical components, and instruments. (L.E.)

  5. Reproducibility of airway luminal size in asthma measured by HRCT.

    Science.gov (United States)

    Brown, Robert H; Henderson, Robert J; Sugar, Elizabeth A; Holbrook, Janet T; Wise, Robert A

    2017-10-01

    Brown RH, Henderson RJ, Sugar EA, Holbrook JT, Wise RA, on behalf of the American Lung Association Airways Clinical Research Centers. Reproducibility of airway luminal size in asthma measured by HRCT. J Appl Physiol 123: 876-883, 2017. First published July 13, 2017; doi:10.1152/japplphysiol.00307.2017.-High-resolution CT (HRCT) is a well-established imaging technology used to measure lung and airway morphology in vivo. However, there is a surprising lack of studies examining HRCT reproducibility. The CPAP Trial was a multicenter, randomized, three-parallel-arm, sham-controlled 12-wk clinical trial to assess the use of a nocturnal continuous positive airway pressure (CPAP) device on airway reactivity to methacholine. The lack of a treatment effect of CPAP on clinical or HRCT measures provided an opportunity for the current analysis. We assessed the reproducibility of HRCT imaging over 12 wk. Intraclass correlation coefficients (ICCs) were calculated for individual airway segments, individual lung lobes, both lungs, and air trapping. The ICC [95% confidence interval (CI)] for airway luminal size at total lung capacity ranged from 0.95 (0.91, 0.97) to 0.47 (0.27, 0.69). The ICC (95% CI) for airway luminal size at functional residual capacity ranged from 0.91 (0.85, 0.95) to 0.32 (0.11, 0.65). The ICC measurements for airway distensibility index and wall thickness were lower, ranging from poor (0.08) to moderate (0.63) agreement. The ICC for air trapping at functional residual capacity was 0.89 (0.81, 0.94) and varied only modestly by lobe from 0.76 (0.61, 0.87) to 0.95 (0.92, 0.97). In stable well-controlled asthmatic subjects, it is possible to reproducibly image unstimulated airway luminal areas over time, by region, and by size at total lung capacity throughout the lungs. Therefore, any changes in luminal size on repeat CT imaging are more likely due to changes in disease state and less likely due to normal variability. NEW & NOTEWORTHY There is a surprising lack

  6. Audiovisual biofeedback improves diaphragm motion reproducibility in MRI

    Science.gov (United States)

    Kim, Taeho; Pollock, Sean; Lee, Danny; O’Brien, Ricky; Keall, Paul

    2012-01-01

    Purpose: In lung radiotherapy, variations in cycle-to-cycle breathing results in four-dimensional computed tomography imaging artifacts, leading to inaccurate beam coverage and tumor targeting. In previous studies, the effect of audiovisual (AV) biofeedback on the external respiratory signal reproducibility has been investigated but the internal anatomy motion has not been fully studied. The aim of this study is to test the hypothesis that AV biofeedback improves diaphragm motion reproducibility of internal anatomy using magnetic resonance imaging (MRI). Methods: To test the hypothesis 15 healthy human subjects were enrolled in an ethics-approved AV biofeedback study consisting of two imaging sessions spaced ∼1 week apart. Within each session MR images were acquired under free breathing and AV biofeedback conditions. The respiratory signal to the AV biofeedback system utilized optical monitoring of an external marker placed on the abdomen. Synchronously, serial thoracic 2D MR images were obtained to measure the diaphragm motion using a fast gradient-recalled-echo MR pulse sequence in both coronal and sagittal planes. The improvement in the diaphragm motion reproducibility using the AV biofeedback system was quantified by comparing cycle-to-cycle variability in displacement, respiratory period, and baseline drift. Additionally, the variation in improvement between the two sessions was also quantified. Results: The average root mean square error (RMSE) of diaphragm cycle-to-cycle displacement was reduced from 2.6 mm with free breathing to 1.6 mm (38% reduction) with the implementation of AV biofeedback (p-value biofeedback (p-value biofeedback (p-value = 0.012). The diaphragm motion reproducibility improvements with AV biofeedback were consistent with the abdominal motion reproducibility that was observed from the external marker motion variation. Conclusions: This study was the first to investigate the potential of AV biofeedback to improve the motion

  7. Multidisciplinary System Reliability Analysis

    Science.gov (United States)

    Mahadevan, Sankaran; Han, Song; Chamis, Christos C. (Technical Monitor)

    2001-01-01

    The objective of this study is to develop a new methodology for estimating the reliability of engineering systems that encompass multiple disciplines. The methodology is formulated in the context of the NESSUS probabilistic structural analysis code, developed under the leadership of NASA Glenn Research Center. The NESSUS code has been successfully applied to the reliability estimation of a variety of structural engineering systems. This study examines whether the features of NESSUS could be used to investigate the reliability of systems in other disciplines such as heat transfer, fluid mechanics, electrical circuits etc., without considerable programming effort specific to each discipline. In this study, the mechanical equivalence between system behavior models in different disciplines are investigated to achieve this objective. A new methodology is presented for the analysis of heat transfer, fluid flow, and electrical circuit problems using the structural analysis routines within NESSUS, by utilizing the equivalence between the computational quantities in different disciplines. This technique is integrated with the fast probability integration and system reliability techniques within the NESSUS code, to successfully compute the system reliability of multidisciplinary systems. Traditional as well as progressive failure analysis methods for system reliability estimation are demonstrated, through a numerical example of a heat exchanger system involving failure modes in structural, heat transfer and fluid flow disciplines.

  8. Analysis and Application of Reliability

    International Nuclear Information System (INIS)

    Jeong, Hae Seong; Park, Dong Ho; Kim, Jae Ju

    1999-05-01

    This book tells of analysis and application of reliability, which includes definition, importance and historical background of reliability, function of reliability and failure rate, life distribution and assumption of reliability, reliability of unrepaired system, reliability of repairable system, sampling test of reliability, failure analysis like failure analysis by FEMA and FTA, and cases, accelerated life testing such as basic conception, acceleration and acceleration factor, and analysis of accelerated life testing data, maintenance policy about alternation and inspection.

  9. REPRODUCIBILITY OF MACULAR PIGMENT OPTICAL DENSITY MEASUREMENT BY TWO-WAVELENGTH AUTOFLUORESCENCE IN A CLINICAL SETTING.

    Science.gov (United States)

    You, Qi Sheng; Bartsch, Dirk-Uwe G; Espina, Mark; Alam, Mostafa; Camacho, Natalia; Mendoza, Nadia; Freeman, William R

    2016-07-01

    Macular pigment, composed of lutein, zeaxanthin, and meso-zeaxanthin, is postulated to protect against age-related macular degeneration, likely because of filtering blue light and its antioxidant properties. Macular pigment optical density (MPOD) is reported to be associated with macular function evaluated by visual acuity and multifocal electroretinogram. Given the importance of macular pigment, reliable and accurate measurement methods are important. The main purpose of this study is to determine the reproducibility of MPOD measurement by two-wavelength autofluorescence method using scanning laser ophthalmoscopy. Sixty-eight eyes of 39 persons were enrolled in the study, including 11 normal eyes, 16 eyes with wet age-related macular degeneration, 16 eyes with dry age-related macular degeneration, 11 eyes with macular edema due to diabetic mellitus, branch retinal vein occlusion or macular telangiectasia, and 14 eyes with tractional maculopathy, including vitreomacular traction, epiretinal membrane, or macular hole. MPOD was measured with a two-wavelength (488 and 514 nm) autofluorescence method with the Spectralis HRA + OCT after pupil dilation. The measurement was repeated for each eye 10 minutes later. The analysis of variance and Bland-Altman plot were used to assess the reproducibility between the two measurements. The mean MPOD at eccentricities of 1° and 2° was 0.36 ± 0.17 (range: 0.04-0.69) and 0.15 ± 0.08 (range: -0.03 to 0.35) for the first measurement and 0.35 ± 0.17 (range: 0.02-0.68) and 0.15 ± 0.08 (range: -0.01 to 0.33) for the second measurement, respectively. The difference between the 2 measurements was not statistically significant, and the Bland-Altman plot showed 7.4% and 5.9% points outside the 95% limits of agreement, indicating an overall excellent reproducibility. Similarly, there is no significant difference between the first and second measurements of MPOD volume within eccentricities of 1°, 2°, and 6° radius, and the Bland

  10. Reproducibility of graph metrics of human brain functional networks.

    Science.gov (United States)

    Deuker, Lorena; Bullmore, Edward T; Smith, Marie; Christensen, Soren; Nathan, Pradeep J; Rockstroh, Brigitte; Bassett, Danielle S

    2009-10-01

    Graph theory provides many metrics of complex network organization that can be applied to analysis of brain networks derived from neuroimaging data. Here we investigated the test-retest reliability of graph metrics of functional networks derived from magnetoencephalography (MEG) data recorded in two sessions from 16 healthy volunteers who were studied at rest and during performance of the n-back working memory task in each session. For each subject's data at each session, we used a wavelet filter to estimate the mutual information (MI) between each pair of MEG sensors in each of the classical frequency intervals from gamma to low delta in the overall range 1-60 Hz. Undirected binary graphs were generated by thresholding the MI matrix and 8 global network metrics were estimated: the clustering coefficient, path length, small-worldness, efficiency, cost-efficiency, assortativity, hierarchy, and synchronizability. Reliability of each graph metric was assessed using the intraclass correlation (ICC). Good reliability was demonstrated for most metrics applied to the n-back data (mean ICC=0.62). Reliability was greater for metrics in lower frequency networks. Higher frequency gamma- and beta-band networks were less reliable at a global level but demonstrated high reliability of nodal metrics in frontal and parietal regions. Performance of the n-back task was associated with greater reliability than measurements on resting state data. Task practice was also associated with greater reliability. Collectively these results suggest that graph metrics are sufficiently reliable to be considered for future longitudinal studies of functional brain network changes.

  11. Safety and reliability criteria

    International Nuclear Information System (INIS)

    O'Neil, R.

    1978-01-01

    Nuclear power plants and, in particular, reactor pressure boundary components have unique reliability requirements, in that usually no significant redundancy is possible, and a single failure can give rise to possible widespread core damage and fission product release. Reliability may be required for availability or safety reasons, but in the case of the pressure boundary and certain other systems safety may dominate. Possible Safety and Reliability (S and R) criteria are proposed which would produce acceptable reactor design. Without some S and R requirement the designer has no way of knowing how far he must go in analysing his system or component, or whether his proposed solution is likely to gain acceptance. The paper shows how reliability targets for given components and systems can be individually considered against the derived S and R criteria at the design and construction stage. Since in the case of nuclear pressure boundary components there is often very little direct experience on which to base reliability studies, relevant non-nuclear experience is examined. (author)

  12. Proposed reliability cost model

    Science.gov (United States)

    Delionback, L. M.

    1973-01-01

    The research investigations which were involved in the study include: cost analysis/allocation, reliability and product assurance, forecasting methodology, systems analysis, and model-building. This is a classic example of an interdisciplinary problem, since the model-building requirements include the need for understanding and communication between technical disciplines on one hand, and the financial/accounting skill categories on the other. The systems approach is utilized within this context to establish a clearer and more objective relationship between reliability assurance and the subcategories (or subelements) that provide, or reenforce, the reliability assurance for a system. Subcategories are further subdivided as illustrated by a tree diagram. The reliability assurance elements can be seen to be potential alternative strategies, or approaches, depending on the specific goals/objectives of the trade studies. The scope was limited to the establishment of a proposed reliability cost-model format. The model format/approach is dependent upon the use of a series of subsystem-oriented CER's and sometimes possible CTR's, in devising a suitable cost-effective policy.

  13. Reproducible localization of interictal epileptiform discharges using EEG-triggered fMRI

    International Nuclear Information System (INIS)

    Symms, M.R.; Allen, P.J.; Fish, D.R.; Barker, G.J.

    1999-01-01

    We report preliminary experiences using fMRI triggered by EEG to localize the site of interictal epileptiform activity. EEG was recorded in the scanner and monitored on-line; the recording quality was good enough to allow the clear identification of spikes in the EEG. Snap-shot EPI was performed 2-4 s after an epileptiform discharge ('spike') or after at least 10 s of background activity ('rest') was observed. A pixel-by-pixel t-test was performed between the 'rest' and the 'spike' images to determine areas of significant activation. Significant activation was obtained in a patient with epilepsy. To assess the reliability and reproducibility of the technique, the patient was scanned on four separate occasions with similar areas being activated in all the studies, confirming the validity of the result. (author)

  14. Cytological Punctures in the Diagnosis of Renal Tumours: A Study on Accuracy and Reproducibility

    DEFF Research Database (Denmark)

    Kümmerlin, Intan P E D; Smedts, Frank; ten Kate, Fiebo J W

    2009-01-01

    BACKGROUND: Fine needle aspiration (FNA) cytology is under consideration as an auxiliary preoperative diagnostic technique in the diagnosis of renal masses. However, reports for FNA are contradictory with regard to diagnostic accuracy and applicability. OBJECTIVE: To evaluate the diagnostic...... accuracy and reproducibility of FNA from renal masses. DESIGN: FNAs performed in-bench (hematoxylin and eosin [H&E] stains) from 66 consecutive renal tumours (58 malignant and 8 benign tumours) were presented twice with a 6-mo interval to five pathologists with little experience in renal cytology...... benignity. CONCLUSION: Despite the lack of experience in renal cytology, all pathologists showed a high diagnostic yield and good overall accuracy in distinguishing between malignant and benign tumours. Concordance in subtyping varied widely among pathologists and was reliable only for clear cell renal cell...

  15. Reproducibility of skeletal muscle vasodilatation responses to Stroop mental challenge over repeated sessions.

    Science.gov (United States)

    Hamer, Mark; Boutcher, Yati N; Park, Young; Boutcher, Stephen H

    2006-08-01

    Skeletal muscle blood flow responses to stress have implications for psychobiological disease pathways. An important assumption underlying psychophysiological studies relating stress reactivity with disease risk is that individuals are characterized by stable response profiles that can be reliably assessed using acute psychophysiological stress testing. We examined the reproducibility of forearm vasodilatation, blood pressure, and cardiac responses to a 2 min Stroop mental challenge over two repeated stress sessions that were on average 3.6 months apart. Participants were 21 healthy men and women (aged 21.8+/-3.7 years). Vasodilatation, blood pressure and heart rate responses displayed no habituation between sessions, although there was significantly greater cardiac parasympathetic involvement during the second testing session. Significant test-retest correlations between the sessions were observed for both forearm blood flow and heart rate reactivity. These findings demonstrate skeletal muscle vasodilatation responses to repeated stress are robust, so may be a useful psychophysiological indicator in studies of stress reactivity and disease risk.

  16. Reproducibility and diagnostic performance of shear wave elastography in evaluating breast solid mass.

    Science.gov (United States)

    Hong, Sun; Woo, Ok Hee; Shin, Hye Seon; Hwang, Soon-Young; Cho, Kyu Ran; Seo, Bo Kyoung

    Shear wave elastography (SWE) was performed independently by two radiologists in 264 solid breast masses. The images were reviewed for color overlay pattern (COP) classification by the two radiologists, double blinded to any information. The interobserver agreement of the COP was almost perfect (κ=0.908) and high in E max (ICC=0.89). The AUC value of the COP (0.954) was significantly higher than that of E max (0.915) (p=0.002) but not significantly different from that of E max combined with COP (0.957) (p=0.098). The SWE color overlay pattern and E max of breast masses were highly reproducible. The COP had better diagnostic ability than E max , suggesting that COP may be a more reliable parameter for solid breast mass evaluation. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Reproducibility of real-time shear wave elastography in the evaluation of liver elasticity

    International Nuclear Information System (INIS)

    Ferraioli, Giovanna; Tinelli, Carmine; Zicchetti, Mabel; Above, Elisabetta; Poma, Gianluigi; Di Gregorio, Marta; Filice, Carlo

    2012-01-01

    Objective: To evaluate the reproducibility of real-time shear wave elastography in assessing liver elasticity in healthy volunteers. Methods: Forty-two volunteers were studied in day 1. Shear wave elastography studies were performed by using the ultrasound system Aixplorer™ (SuperSonic Imagine S.A., Aix-en-Provence, France) with a convex broadband probe. Measurements were carried by two operators, an expert (operator 1) and a novice (operator 2). Examinations were performed on the right lobe of the liver. Each operator performed 10 consecutive measurements in each volunteer. In a subset of volunteers (n = 18) measurements were performed twice on two different days (day 1 and day 2). Intraobserver and interobserver agreement were assessed by intraclass correlation coefficient. Results: Intraobserver agreement between measurements performed in the same subject in the same day (day 1 or day 2) showed intraclass correlation coefficient values of 0.95 (95% confidence interval, 0.93–0.98) and 0.93 (95% confidence interval, 0.90–0.96) for operator 1 and operator 2, respectively. Intraobserver agreement between measurements performed in the same subject in different days showed intraclass correlation coefficient values of 0.84 (95% confidence interval, 0.69–0.98) and 0.65 (95% confidence interval, 0.39–0.91) for operator 1 and operator 2, respectively. Interobserver agreement was 0.88 (95% confidence interval, 0.82–0.94). Conclusions: The results of this study show that shear wave elastography is a reliable and reproducible noninvasive method for the assessment of liver elasticity. Expert operator had higher reproducibility of measurements over time than novice operator.

  18. Reproducibility of real-time shear wave elastography in the evaluation of liver elasticity

    Energy Technology Data Exchange (ETDEWEB)

    Ferraioli, Giovanna, E-mail: giovanna.ferraioli@unipv.it [Ultrasound Unit, Infectious Diseases Department, IRCCS San Matteo Hospital Foundation, University of Pavia, Via Taramelli 5, 27100 Pavia (Italy); Tinelli, Carmine, E-mail: ctinelli@smatteo.pv.it [Clinical Epidemiology and Biometric Unit, IRCCS San Matteo Hospital Foundation, Viale Golgi 19, 27100 Pavia (Italy); Zicchetti, Mabel, E-mail: mabel.zicchetti@unipv.it [Ultrasound Unit, Infectious Diseases Department, IRCCS San Matteo Hospital Foundation, University of Pavia, Via Taramelli 5, 27100 Pavia (Italy); Above, Elisabetta, E-mail: betta.above@gmail.com [Ultrasound Unit, Infectious Diseases Department, IRCCS San Matteo Hospital Foundation, University of Pavia, Via Taramelli 5, 27100 Pavia (Italy); Poma, Gianluigi, E-mail: gigi.poma@libero.it [Ultrasound Unit, Infectious Diseases Department, IRCCS San Matteo Hospital Foundation, University of Pavia, Via Taramelli 5, 27100 Pavia (Italy); Di Gregorio, Marta, E-mail: martadigregorio@virgilio.it [Ultrasound Unit, Infectious Diseases Department, IRCCS San Matteo Hospital Foundation, University of Pavia, Via Taramelli 5, 27100 Pavia (Italy); Filice, Carlo, E-mail: carfil@unipv.it [Ultrasound Unit, Infectious Diseases Department, IRCCS San Matteo Hospital Foundation, University of Pavia, Via Taramelli 5, 27100 Pavia (Italy)

    2012-11-15

    Objective: To evaluate the reproducibility of real-time shear wave elastography in assessing liver elasticity in healthy volunteers. Methods: Forty-two volunteers were studied in day 1. Shear wave elastography studies were performed by using the ultrasound system Aixplorer Trade-Mark-Sign (SuperSonic Imagine S.A., Aix-en-Provence, France) with a convex broadband probe. Measurements were carried by two operators, an expert (operator 1) and a novice (operator 2). Examinations were performed on the right lobe of the liver. Each operator performed 10 consecutive measurements in each volunteer. In a subset of volunteers (n = 18) measurements were performed twice on two different days (day 1 and day 2). Intraobserver and interobserver agreement were assessed by intraclass correlation coefficient. Results: Intraobserver agreement between measurements performed in the same subject in the same day (day 1 or day 2) showed intraclass correlation coefficient values of 0.95 (95% confidence interval, 0.93-0.98) and 0.93 (95% confidence interval, 0.90-0.96) for operator 1 and operator 2, respectively. Intraobserver agreement between measurements performed in the same subject in different days showed intraclass correlation coefficient values of 0.84 (95% confidence interval, 0.69-0.98) and 0.65 (95% confidence interval, 0.39-0.91) for operator 1 and operator 2, respectively. Interobserver agreement was 0.88 (95% confidence interval, 0.82-0.94). Conclusions: The results of this study show that shear wave elastography is a reliable and reproducible noninvasive method for the assessment of liver elasticity. Expert operator had higher reproducibility of measurements over time than novice operator.

  19. Reproducibility of heart rate and perceptual demands of game-based training drills in handball players

    Directory of Open Access Journals (Sweden)

    Gilles Ravier

    2017-12-01

    Full Text Available Game-based training are popular in team-sports; however there is a lack of research specific to team handball. The aim of this study was to assess i the test-retest reliability of heart rate (HR, time spent in HR zone intensities and rating of perceived exertion of a novel small-sided game, ii and whether it is comparable to that of generic intermittent shuttle running and match play with team handball players. Fourteen elite male handball players completed each exercise comprising two periods of 10min interspersed with 2min recovery in separate occasions and repeated them one week apart. Exercises consisted of intermittent 30s-30s shuttle running (ISR, intermittent 30s-30s small-sided game (with 3-a-side field players, 3vs3 and match play (with 6-a-side field players, 6vs6. Mean HR demonstrated high level of reproducibility for the three drills (r = 0.86-0.89, TEM = 2.21-2.63 bpm, CV = 1.23-1.55%. For time spent in heart rate zones TEMs reached up 1.12, 1.40 and 2.48 min for ISR, 6vs6 and 3vs3, respectively. Specifically for HR zone higher than 90% of HRmax, CVs showed wide extent of scores with 9.73 (ISR, 27.39 (6vs6 and 108.29% (3vs3. Mean HR results suggest that physiological response was consistent between sessions. Because of the poor reproducibility for time spent in the target zone higher than 90% of HRmax, the efficiency of both 3vs3 and 6vs6 in improving aerobic power should be analysed with caution. The present results suggest that reproducibility of physiological demand of ball-drills should be considered before prescribing them as conditioning training.

  20. Accuracy and reproducibility of tumor positioning during prolonged and multi-modality animal imaging studies

    International Nuclear Information System (INIS)

    Zhang Mutian; Huang Minming; Le, Carl; Zanzonico, Pat B; Ling, C Clifton; Koutcher, Jason A; Humm, John L; Claus, Filip; Kolbert, Katherine S; Martin, Kyle

    2008-01-01

    Dedicated small-animal imaging devices, e.g. positron emission tomography (PET), computed tomography (CT) and magnetic resonance imaging (MRI) scanners, are being increasingly used for translational molecular imaging studies. The objective of this work was to determine the positional accuracy and precision with which tumors in situ can be reliably and reproducibly imaged on dedicated small-animal imaging equipment. We designed, fabricated and tested a custom rodent cradle with a stereotactic template to facilitate registration among image sets. To quantify tumor motion during our small-animal imaging protocols, 'gold standard' multi-modality point markers were inserted into tumor masses on the hind limbs of rats. Three types of imaging examination were then performed with the animals continuously anesthetized and immobilized: (i) consecutive microPET and MR images of tumor xenografts in which the animals remained in the same scanner for 2 h duration, (ii) multi-modality imaging studies in which the animals were transported between distant imaging devices and (iii) serial microPET scans in which the animals were repositioned in the same scanner for subsequent images. Our results showed that the animal tumor moved by less than 0.2-0.3 mm over a continuous 2 h microPET or MR imaging session. The process of transporting the animal between instruments introduced additional errors of ∼0.2 mm. In serial animal imaging studies, the positioning reproducibility within ∼0.8 mm could be obtained.

  1. Enhancing reproducibility of SALDI MS detection by concentrating analytes within laser spot.

    Science.gov (United States)

    Teng, Fei; Zhu, Qunyan; Wang, Yalei; Du, Juan; Lu, Nan

    2018-03-01

    Surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI TOF MS) has become one of the most important analytical methods due to its less interference at low molecular weight range. However, it is still a challenge to obtain a good reproducibility of SALDI TOF MS because of the inhomogeneous distribution of analyte molecules induced by coffee ring effect. We propose a universal and reliable method to eliminate the coffee ring effect by concentrating all the analyte molecules within the laser spot. This method exhibits an excellent reproducibility of spot-to-spot and substrate-to-substrate, and the relative standard deviations (RSDs) for different concentrations are lower than 12.6%. It also performs good linear dependency (R 2 > 0.98) in the log-log plot with the concentration range of 1nM to 1μM, and the limit of detection for R6G is down to 1fmol. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. A catalyzing phantom for reproducible dynamic conversion of hyperpolarized [1-¹³C]-pyruvate.

    Science.gov (United States)

    Walker, Christopher M; Lee, Jaehyuk; Ramirez, Marc S; Schellingerhout, Dawid; Millward, Steven; Bankson, James A

    2013-01-01

    In vivo real time spectroscopic imaging of hyperpolarized ¹³C labeled metabolites shows substantial promise for the assessment of physiological processes that were previously inaccessible. However, reliable and reproducible methods of measurement are necessary to maximize the effectiveness of imaging biomarkers that may one day guide personalized care for diseases such as cancer. Animal models of human disease serve as poor reference standards due to the complexity, heterogeneity, and transient nature of advancing disease. In this study, we describe the reproducible conversion of hyperpolarized [1-¹³C]-pyruvate to [1-¹³C]-lactate using a novel synthetic enzyme phantom system. The rate of reaction can be controlled and tuned to mimic normal or pathologic conditions of varying degree. Variations observed in the use of this phantom compare favorably against within-group variations observed in recent animal studies. This novel phantom system provides crucial capabilities as a reference standard for the optimization, comparison, and certification of quantitative imaging strategies for hyperpolarized tracers.

  3. A catalyzing phantom for reproducible dynamic conversion of hyperpolarized [1-¹³C]-pyruvate.

    Directory of Open Access Journals (Sweden)

    Christopher M Walker

    Full Text Available In vivo real time spectroscopic imaging of hyperpolarized ¹³C labeled metabolites shows substantial promise for the assessment of physiological processes that were previously inaccessible. However, reliable and reproducible methods of measurement are necessary to maximize the effectiveness of imaging biomarkers that may one day guide personalized care for diseases such as cancer. Animal models of human disease serve as poor reference standards due to the complexity, heterogeneity, and transient nature of advancing disease. In this study, we describe the reproducible conversion of hyperpolarized [1-¹³C]-pyruvate to [1-¹³C]-lactate using a novel synthetic enzyme phantom system. The rate of reaction can be controlled and tuned to mimic normal or pathologic conditions of varying degree. Variations observed in the use of this phantom compare favorably against within-group variations observed in recent animal studies. This novel phantom system provides crucial capabilities as a reference standard for the optimization, comparison, and certification of quantitative imaging strategies for hyperpolarized tracers.

  4. The reproducibility of RAPD profiles: Effects of PCR components on RAPD analysis of four centaurium species

    Directory of Open Access Journals (Sweden)

    Skorić Marijana

    2012-01-01

    Full Text Available Random amplified polymorphic DNA (RAPD analysis is a simple and reliable method used to detect DNA polymorphism. Several factors can affect the amplification profiles, thereby causing false bands and non-reproducibility of the assay. In this study, we analyzed the effects of different concentrations of primer, magnesium chloride, template DNA and Taq DNA polymerase to develop and standardize a RAPD protocol for Centaurium species. The optimized PCR reaction mixture included: 50 ng of DNA extracted using a CTbased protocol, 2.5 mM MgCl2, 7.5 pmol primer and 2 U of Taq polymerase in a final volume of 25 μl. Each of the five primers used in experiments (OPB11, OPB15, OPB18, OPF05 and OPH02 generated reproducible and distinguishable fingerprinting patterns of four Centaurium species. The obtained optimized RAPD protocol and the selected primers are useful for our further work in the genetic diversity studies of Centaurium species.

  5. Evaluating the Reproducibility of Motion Analysis Scanning of the Spine during Walking

    Directory of Open Access Journals (Sweden)

    Aaron Gipsman

    2014-01-01

    Full Text Available The Formetric 4D dynamic system (Diers International GmbH, Schlangenbad, Germany is a rasterstereography based imaging system designed to evaluate spinal deformity, providing radiation-free imaging of the position, rotation, and shape of the spine during the gait cycle. Purpose. This study was designed to evaluate whether repeated measurements with the Formetric 4D dynamic system would be reproducible with a standard deviation of less than +/− 3 degrees. This study looked at real-time segmental motion, measuring kyphosis, lordosis, trunk length, pelvic, and T4 and L1 vertebral body rotation. Methods. Twenty healthy volunteers each underwent 3 consecutive scans. Measurements for kyphosis, lordosis, trunk length, and rotations of T4, L1, and the pelvis were recorded for each trial. Results. The average standard deviations of same-day repeat measurements were within +/− 3 degrees with a range of 0.51 degrees to 2.3 degrees. Conclusions. The surface topography system calculated reproducible measurements with error ranges comparable to the current gold standard in dynamic spinal motion analysis. Therefore, this technique should be considered of high clinical value for reliably evaluating segmental motion and spinal curvatures and should further be evaluated in the setting of adolescent idiopathic scoliosis.

  6. Geometric Three-Dimensional End-to-Side Microvascular Anastomosis: A Simple and Reproducible Technique.

    Science.gov (United States)

    Ooi, Adrian S H; Butz, Daniel R; Fisher, Sean M; Collier, Zachary J; Gottlieb, Lawrence J

    2018-05-01

     End-to-side (ETS) anastomoses are useful when preservation of distal vascularity is critical. The ideal ETS microanastomosis should maintain a wide aperture and have a smooth take-off point to minimize turbulence, vessel spasm, and thrombogenicity of the suture line. We have developed a unique, dependable, and reproducible geometric technique for ETS anastomoses, and analyze its efficacy in our series of patients.  The geometric ETS technique involves creating a three-dimensional (3D) diamond-shaped defect on the recipient vessel wall, followed by a slit incision of the donor vessel to create a "spatula" fitting this defect. This technique removes sutures from the point of most turbulent blood flow while holding the recipient vessel open with a patch vesselplasty effect. We perform a retrospective review of a single surgeon's experience using this technique.  The geometric 3D ETS technique was used in 87 free flaps with a total of 102 ETS anastomoses in a wide range of cases including head and neck, trunk and genitourinary, and extremity reconstruction. Overall, free flap success rates were 98%.  The geometric 3D ETS technique creates a wide anastomosis, minimizes turbulence-inducing thrombogenicity, and mechanically holds the recipient vessel open. It is reliable and reproducible, and when performed properly has been shown to have high rates of success in a large group of free tissue transfer patients. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  7. Reproducible automated breast density measure with no ionizing radiation using fat-water decomposition MRI.

    Science.gov (United States)

    Ding, Jie; Stopeck, Alison T; Gao, Yi; Marron, Marilyn T; Wertheim, Betsy C; Altbach, Maria I; Galons, Jean-Philippe; Roe, Denise J; Wang, Fang; Maskarinec, Gertraud; Thomson, Cynthia A; Thompson, Patricia A; Huang, Chuan

    2018-04-06

    Increased breast density is a significant independent risk factor for breast cancer, and recent studies show that this risk is modifiable. Hence, breast density measures sensitive to small changes are desired. Utilizing fat-water decomposition MRI, we propose an automated, reproducible breast density measurement, which is nonionizing and directly comparable to mammographic density (MD). Retrospective study. The study included two sample sets of breast cancer patients enrolled in a clinical trial, for concordance analysis with MD (40 patients) and reproducibility analysis (10 patients). The majority of MRI scans (59 scans) were performed with a 1.5T GE Signa scanner using radial IDEAL-GRASE sequence, while the remaining (seven scans) were performed with a 3T Siemens Skyra using 3D Cartesian 6-echo GRE sequence with a similar fat-water separation technique. After automated breast segmentation, breast density was calculated using FraGW, a new measure developed to reliably reflect the amount of fibroglandular tissue and total water content in the entire breast. Based on its concordance with MD, FraGW was calibrated to MR-based breast density (MRD) to be comparable to MD. A previous breast density measurement, Fra80-the ratio of breast voxels with density changes and treatment response. 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018. © 2018 International Society for Magnetic Resonance in Medicine.

  8. One-Step Printable Perovskite Films Fabricated under Ambient Conditions for Efficient and Reproducible Solar Cells.

    Science.gov (United States)

    Jung, Yen-Sook; Hwang, Kyeongil; Heo, Youn-Jung; Kim, Jueng-Eun; Lee, Donmin; Lee, Cheol-Ho; Joh, Han-Ik; Yeo, Jun-Seok; Kim, Dong-Yu

    2017-08-23

    Despite the potential of roll-to-roll processing for the fabrication of perovskite films, the realization of highly efficient and reproducible perovskite solar cells (PeSCs) through continuous coating techniques and low-temperature processing is still challenging. Here, we demonstrate that efficient and reliable CH 3 NH 3 PbI 3 (MAPbI 3 ) films fabricated by a printing process can be achieved through synergetic effects of binary processing additives, N-cyclohexyl-2-pyrrolidone (CHP) and dimethyl sulfoxide (DMSO). Notably, these perovskite films are deposited from premixed perovskite solutions for facile one-step processing under a room-temperature and ambient atmosphere. The CHP molecules result in the uniform and homogeneous perovskite films even in the one-step slot-die system, which originate from the high boiling point and low vapor pressure of CHP. Meanwhile, the DMSO molecules facilitate the growth of perovskite grains by forming intermediate states with the perovskite precursor molecules. Consequently, fully printed PeSC based on the binary additive system exhibits a high PCE of 12.56% with a high reproducibility.

  9. Reliability Centered Maintenance - Methodologies

    Science.gov (United States)

    Kammerer, Catherine C.

    2009-01-01

    Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.

  10. Issues in cognitive reliability

    International Nuclear Information System (INIS)

    Woods, D.D.; Hitchler, M.J.; Rumancik, J.A.

    1984-01-01

    This chapter examines some problems in current methods to assess reactor operator reliability at cognitive tasks and discusses new approaches to solve these problems. The two types of human failures are errors in the execution of an intention and errors in the formation/selection of an intention. Topics considered include the types of description, error correction, cognitive performance and response time, the speed-accuracy tradeoff function, function based task analysis, and cognitive task analysis. One problem of human reliability analysis (HRA) techniques in general is the question of what are the units of behavior whose reliability are to be determined. A second problem for HRA is that people often detect and correct their errors. The use of function based analysis, which maps the problem space for plant control, is recommended

  11. Reproducible analyses of microbial food for advanced life support systems

    Science.gov (United States)

    Petersen, Gene R.

    1988-01-01

    The use of yeasts in controlled ecological life support systems (CELSS) for microbial food regeneration in space required the accurate and reproducible analysis of intracellular carbohydrate and protein levels. The reproducible analysis of glycogen was a key element in estimating overall content of edibles in candidate yeast strains. Typical analytical methods for estimating glycogen in Saccharomyces were not found to be entirely aplicable to other candidate strains. Rigorous cell lysis coupled with acid/base fractionation followed by specific enzymatic glycogen analyses were required to obtain accurate results in two strains of Candida. A profile of edible fractions of these strains was then determined. The suitability of yeasts as food sources in CELSS food production processes is discussed.

  12. Tools for Reproducibility and Extensibility in Scientific Research

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Open inquiry through reproducing results is fundamental to the scientific process. Contemporary research relies on software engineering pipelines to collect, process, and analyze data. The open source projects within Project Jupyter facilitate these objectives by bringing software engineering within the context of scientific communication. We will highlight specific projects that are computational building blocks for scientific communication, starting with the Jupyter Notebook. We will also explore applications of projects that build off of the Notebook such as Binder, JupyterHub, and repo2docker. We will discuss how these projects can individually and jointly improve reproducibility in scientific communication. Finally, we will demonstrate applications of Jupyter software that allow researchers to build upon the code of other scientists, both to extend their work and the work of others.    There will be a follow-up demo session in the afternoon, hosted by iML. Details can be foun...

  13. MASSIVE DATA, THE DIGITIZATION OF SCIENCE, AND REPRODUCIBILITY OF RESULTS

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    As the scientific enterprise becomes increasingly computational and data-driven, the nature of the information communicated must change. Without inclusion of the code and data with published computational results, we are engendering a credibility crisis in science. Controversies such as ClimateGate, the microarray-based drug sensitivity clinical trials under investigation at Duke University, and retractions from prominent journals due to unverified code suggest the need for greater transparency in our computational science. In this talk I argue that the scientific method be restored to (1) a focus on error control as central to scientific communication and (2) complete communication of the underlying methodology producing the results, ie. reproducibility. I outline barriers to these goals based on recent survey work (Stodden 2010), and suggest solutions such as the “Reproducible Research Standard” (Stodden 2009), giving open licensing options designed to create an intellectual property framework for scien...

  14. Reproducibility of Mammography Units, Film Processing and Quality Imaging

    International Nuclear Information System (INIS)

    Gaona, Enrique

    2003-01-01

    The purpose of this study was to carry out an exploratory survey of the problems of quality control in mammography and processors units as a diagnosis of the current situation of mammography facilities. Measurements of reproducibility, optical density, optical difference and gamma index are included. Breast cancer is the most frequently diagnosed cancer and is the second leading cause of cancer death among women in the Mexican Republic. Mammography is a radiographic examination specially designed for detecting breast pathology. We found that the problems of reproducibility of AEC are smaller than the problems of processors units because almost all processors fall outside of the acceptable variation limits and they can affect the mammography quality image and the dose to breast. Only four mammography units agree with the minimum score established by ACR and FDA for the phantom image

  15. Reproducibility of CT bone dosimetry: Operator versus automated ROI definition

    International Nuclear Information System (INIS)

    Louis, O.; Luypaert, R.; Osteaux, M.; Kalender, W.

    1988-01-01

    Intrasubject reproducibility with repeated determination of vertebral mineral density from a given set of CT images was investigated. The region of interest (ROI) in 10 patient scans was selected by four independent operators either manually or with an automated procedure separating cortical and spongeous bone, the operators being requested to interact in ROI selection. The mean intrasubject variation was found to be much lower with the automated process (0.3 to 0.6%) than with the conventional method (2.5 to 5.2%). In a second study, 10 patients were examined twice to determine the reproducibility of CT slice selection by the operator. The errors were of the same order of magnitude as in ROI selection. (orig.)

  16. Timbral aspects of reproduced sound in small rooms. I

    DEFF Research Database (Denmark)

    Bech, Søren

    1995-01-01

    , has been simulated using an electroacoustic setup. The model included the direct sound, 17 individual reflections, and the reverberant field. The threshold of detection and just-noticeable differences for an increase in level were measured for individual reflections using eight subjects for noise......This paper reports some of the influences of individual reflections on the timbre of reproduced sound. A single loudspeaker with frequency-independent directivity characteristics, positioned in a listening room of normal size with frequency-independent absorption coefficients of the room surfaces...... and speech. The results have shown that the first-order floor and ceiling reflections are likely to individually contribute to the timbre of reproduced speech. For a noise signal, additional reflections from the left sidewall will contribute individually. The level of the reverberant field has been found...

  17. Transition questions in clinical practice - validity and reproducibility

    DEFF Research Database (Denmark)

    Lauridsen, Henrik Hein

    2008-01-01

    Transition questions in CLINICAL practice - validity and reproducibility Lauridsen HH1, Manniche C3, Grunnet-Nilsson N1, Hartvigsen J1,2 1   Clinical Locomotion Science, Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark. e-mail: hlauridsen......@health.sdu.dk 2   Nordic Institute of Chiropractic and Clinical Biomechanics, Part of Clinical Locomotion Science, Odense, Denmark 3   Backcenter Funen, Part of Clinical Locomotion Science, Ringe, Denmark   Abstract  Understanding a change score is indispensable for interpretation of results from clinical studies...... are reproducible in patients with low back pain and/or leg pain. Despite critique of several biases, our results have reinforced the construct validity of TQ’s as an outcome measure since only 1 hypothesis was rejected. On the basis of our findings we have outlined a proposal for a standardised use of transition...

  18. Properties of galaxies reproduced by a hydrodynamic simulation

    Science.gov (United States)

    Vogelsberger, M.; Genel, S.; Springel, V.; Torrey, P.; Sijacki, D.; Xu, D.; Snyder, G.; Bird, S.; Nelson, D.; Hernquist, L.

    2014-05-01

    Previous simulations of the growth of cosmic structures have broadly reproduced the `cosmic web' of galaxies that we see in the Universe, but failed to create a mixed population of elliptical and spiral galaxies, because of numerical inaccuracies and incomplete physical models. Moreover, they were unable to track the small-scale evolution of gas and stars to the present epoch within a representative portion of the Universe. Here we report a simulation that starts 12 million years after the Big Bang, and traces 13 billion years of cosmic evolution with 12 billion resolution elements in a cube of 106.5 megaparsecs a side. It yields a reasonable population of ellipticals and spirals, reproduces the observed distribution of galaxies in clusters and characteristics of hydrogen on large scales, and at the same time matches the `metal' and hydrogen content of galaxies on small scales.

  19. LHC Orbit Correction Reproducibility and Related Machine Protection

    CERN Document Server

    Baer, T; Schmidt, R; Wenninger, J

    2012-01-01

    The Large Hadron Collider (LHC) has an unprecedented nominal stored beam energy of up to 362 MJ per beam. In order to ensure an adequate machine protection by the collimation system, a high reproducibility of the beam position at collimators and special elements like the final focus quadrupoles is essential. This is realized by a combination of manual orbit corrections, feed forward and real time feedback. In order to protect the LHC against inconsistent orbit corrections, which could put the machine in a vulnerable state, a novel software-based interlock system for orbit corrector currents was developed. In this paper, the principle of the new interlock system is described and the reproducibility of the LHC orbit correction is discussed against the background of this system.

  20. Reproducibility of Computer-Aided Detection Marks in Digital Mammography

    International Nuclear Information System (INIS)

    Kim, Seung Ja; Moon, Woo Kyung; Cho, Nariya; Kim, Sun Mi; Im, Jung Gi; Cha, Joo Hee

    2007-01-01

    To evaluate the performance and reproducibility of a computeraided detection (CAD) system in mediolateral oblique (MLO) digital mammograms taken serially, without release of breast compression. A CAD system was applied preoperatively to the fulfilled digital mammograms of two MLO views taken without release of breast compression in 82 patients (age range: 33 83 years; mean age: 49 years) with previously diagnosed breast cancers. The total number of visible lesion components in 82 patients was 101: 66 masses and 35 microcalcifications. We analyzed the sensitivity and reproducibility of the CAD marks. The sensitivity of the CAD system for first MLO views was 71% (47/66) for masses and 80% (28/35) for microcalcifications. The sensitivity of the CAD system for second MLO views was 68% (45/66) for masses and 17% (6/35) for microcalcifications. In 84 ipsilateral serial MLO image sets (two patients had bilateral cancers), identical images, regardless of the existence of CAD marks, were obtained for 35% (29/84) and identical images with CAD marks were obtained for 29% (23/78). Identical images, regardless of the existence of CAD marks, for contralateral MLO images were 65% (52/80) and identical images with CAD marks were obtained for 28% (11/39). The reproducibility of CAD marks for the true positive masses in serial MLO views was 84% (42/50) and that for the true positive microcalcifications was 0% (0/34). The CAD system in digital mammograms showed a high sensitivity for detecting masses and microcalcifications. However, reproducibility of microcalcification marks was very low in MLO views taken serially without release of breast compression. Minute positional change and patient movement can alter the images and result in a significant effect on the algorithm utilized by the CAD for detecting microcalcifications

  1. Automated Generation of Technical Documentation and Provenance for Reproducible Research

    Science.gov (United States)

    Jolly, B.; Medyckyj-Scott, D.; Spiekermann, R.; Ausseil, A. G.

    2017-12-01

    Data provenance and detailed technical documentation are essential components of high-quality reproducible research, however are often only partially addressed during a research project. Recording and maintaining this information during the course of a project can be a difficult task to get right as it is a time consuming and often boring process for the researchers involved. As a result, provenance records and technical documentation provided alongside research results can be incomplete or may not be completely consistent with the actual processes followed. While providing access to the data and code used by the original researchers goes some way toward enabling reproducibility, this does not count as, or replace, data provenance. Additionally, this can be a poor substitute for good technical documentation and is often more difficult for a third-party to understand - particularly if they do not understand the programming language(s) used. We present and discuss a tool built from the ground up for the production of well-documented and reproducible spatial datasets that are created by applying a series of classification rules to a number of input layers. The internal model of the classification rules required by the tool to process the input data is exploited to also produce technical documentation and provenance records with minimal additional user input. Available provenance records that accompany input datasets are incorporated into those that describe the current process. As a result, each time a new iteration of the analysis is performed the documentation and provenance records are re-generated to provide an accurate description of the exact process followed. The generic nature of this tool, and the lessons learned during its creation, have wider application to other fields where the production of derivative datasets must be done in an open, defensible, and reproducible way.

  2. Towards reproducible MSMS data preprocessing, quality control and quantification

    OpenAIRE

    Gatto, Laurent; Lilley, Kathryn S.

    2010-01-01

    The development of MSnbase aims at providing researchers dealing with labelled quantitative proteomics data with a transparent, portable, extensible and open-source collaborative framework to easily manipulate and analyse MS2-level raw tandem mass spectrometry data. The implementation in R gives users and developers a great variety of powerful tools to be used in a controlled and reproducible way. Furthermore, MSnbase has been developed following an object-oriented programming paradigm: all i...

  3. Cuban strategy for reproducing, preserving and developing nuclear knowledge

    International Nuclear Information System (INIS)

    Elias Hardy, L.L.; Guzman Martinez, F.; Rodriguez Hoyos, O.E.; Lopez Nunez, A.F.

    2006-01-01

    One of the problems in the changing world is the preservation of knowledge for the next human generation, and nuclear knowledge is not an exception. Cuba has worked for reproducing, preserving, developing and capturing nuclear knowledge, mainly through a higher education centre, the Higher Institute of Nuclear Sciences and Technologies. This institute is a component of a national network in the preparation of manpower not only for nuclear activities but also for environmental and managerial activities too. (author)

  4. Regulating Ultrasound Cavitation in order to Induce Reproducible Sonoporation

    Science.gov (United States)

    Mestas, J.-L.; Alberti, L.; El Maalouf, J.; Béra, J.-C.; Gilles, B.

    2010-03-01

    Sonoporation would be linked to cavitation, which generally appears to be a non reproducible and unstationary phenomenon. In order to obtain an acceptable trade-off between cell mortality and transfection, a regulated cavitation generator based on an acoustical cavitation measurement was developed and tested. The medium to be sonicated is placed in a sample tray. This tray is immersed in in degassed water and positioned above the face of a flat ultrasonic transducer (frequency: 445 kHz; intensity range: 0.08-1.09 W/cm2). This technical configuration was admitted to be conducive to standing-wave generation through reflection at the air/medium interface in the well thus enhancing the cavitation phenomenon. Laterally to the transducer, a homemade hydrophone was oriented to receive the acoustical signal from the bubbles. From this spectral signal recorded at intervals of 5 ms, a cavitation index was calculated as the mean of the cavitation spectrum integration in a logarithmic scale, and the excitation power is automatically corrected. The device generates stable and reproducible cavitation level for a wide range of cavitation setpoint from stable cavitation condition up to full-developed inertial cavitation. For the ultrasound intensity range used, the time delay of the response is lower than 200 ms. The cavitation regulation device was evaluated in terms of chemical bubble collapse effect. Hydroxyl radical production was measured on terephthalic acid solutions. In open loop, the results present a great variability whatever the excitation power. On the contrary the closed loop allows a great reproducibility. This device was implemented for study of sonodynamic effect. The regulation provides more reproducible results independent of cell medium and experimental conditions (temperature, pressure). Other applications of this regulated cavitation device concern internalization of different particles (Quantum Dot) molecules (SiRNA) or plasmids (GFP, DsRed) into different

  5. Serous tubal intraepithelial carcinoma: diagnostic reproducibility and its implications.

    Science.gov (United States)

    Carlson, Joseph W; Jarboe, Elke A; Kindelberger, David; Nucci, Marisa R; Hirsch, Michelle S; Crum, Christopher P

    2010-07-01

    Serous tubal intraepithelial carcinoma (STIC) is detected in between 5% and 7% of women undergoing risk-reduction salpingooophorectomy for mutations in the BRCA1 or 2 genes (BRCA+), and seems to play a role in the pathogenesis of many ovarian and "primary peritoneal" serous carcinomas. The recognition of STIC is germane to the management of BRCA+ women; however, the diagnostic reproducibility of STIC is unknown. Twenty-one cases were selected and classified as STIC or benign, using both hematoxylin and eosin and immunohistochemical stains for p53 and MIB-1. Digital images of 30 hematoxylin and eosin-stained STICs (n=14) or benign tubal epithelium (n=16) were photographed and randomized for blind digital review in a Powerpoint format by 6 experienced gynecologic pathologists and 6 pathology trainees. A generalized kappa statistic for multiple raters was calculated for all groups. For all reviewers, the kappa was 0.333, indicating poor reproducibility; kappa was 0.453 for the experienced gynecologic pathologists (fair-to-good reproducibility), and kappa=0.253 for the pathology residents (poor reproducibility). In the experienced group, 3 of 14 STICs were diagnosed by all 6 reviewers, and 9 of 14 by a majority of the reviewers. These results show that interobserver concordance in the recognition of STIC in high-quality digital images is at best fair-to-good for even experienced gynecologic pathologists, and a proportion cannot be consistently identified even among experienced observers. In view of these findings, a diagnosis of STIC should be corroborated by a second pathologist, if feasible.

  6. Adaptive Learning in Cartesian Product of Reproducing Kernel Hilbert Spaces

    OpenAIRE

    Yukawa, Masahiro

    2014-01-01

    We propose a novel adaptive learning algorithm based on iterative orthogonal projections in the Cartesian product of multiple reproducing kernel Hilbert spaces (RKHSs). The task is estimating/tracking nonlinear functions which are supposed to contain multiple components such as (i) linear and nonlinear components, (ii) high- and low- frequency components etc. In this case, the use of multiple RKHSs permits a compact representation of multicomponent functions. The proposed algorithm is where t...

  7. Reliability issues in PACS

    Science.gov (United States)

    Taira, Ricky K.; Chan, Kelby K.; Stewart, Brent K.; Weinberg, Wolfram S.

    1991-07-01

    Reliability is an increasing concern when moving PACS from the experimental laboratory to the clinical environment. Any system downtime may seriously affect patient care. The authors report on the several classes of errors encountered during the pre-clinical release of the PACS during the past several months and present the solutions implemented to handle them. The reliability issues discussed include: (1) environmental precautions, (2) database backups, (3) monitor routines of critical resources and processes, (4) hardware redundancy (networks, archives), and (5) development of a PACS quality control program.

  8. Reliability Parts Derating Guidelines

    Science.gov (United States)

    1982-06-01

    226-30, October 1974. 66 I, 26. "Reliability of GAAS Injection Lasers", De Loach , B. C., Jr., 1973 IEEE/OSA Conference on Laser Engineering and...Vol. R-23, No. 4, 226-30, October 1974. 28. "Reliability of GAAS Injection Lasers", De Loach , B. C., Jr., 1973 IEEE/OSA Conference on Laser...opnatien ot 󈨊 deg C, mounted on a 4-inach square 0.250~ inch thick al~loy alum~nusi panel.. This mounting technique should be L~ ken into cunoidur~tiou

  9. Reproducibility Test for Thermoluminescence Dosimeter (TLD) Using TLD Radpro

    International Nuclear Information System (INIS)

    Nur Khairunisa Zahidi; Ahmad Bazlie Abdul Kadir; Faizal Azrin Abdul Razalim

    2016-01-01

    Thermoluminescence dosimeters (TLD) as one type of dosimeter which are often used to substitute the film badge. Like a film badge, it is worn for a period of time and then must be processed to determine the dose received. This study was to test the reproducibility of TLD using Radpro reader. This study aimed to determine the dose obtained by TLD-100 chips when irradiated with Co-60 gamma source and to test the effectiveness of TLD Radpro reader as a machine to analyse the TLD. Ten chips of TLD -100 were irradiated using Eldorado machine with Co-60 source at a distance of 5 meters from the source with 2 mSv dose exposure. After the irradiation process, TLD-100 chips were read using the TLD Radpro reader. These steps will be repeated for nine times to obtain reproducibility coefficient, r i . The readings of dose obtained from experiment was almost equivalent to the actual dose. Results shows that the average value obtained for reproducibility coefficient, r i is 6.39 % which is less than 10 %. As conclusion, the dose obtained from experiment considered accurate because its value were almost equivalent to the actual dose and TLD Radpro was verified as a good reader to analyse the TLD. (author)

  10. Reproducibility of gene expression across generations of Affymetrix microarrays

    Directory of Open Access Journals (Sweden)

    Haslett Judith N

    2003-06-01

    Full Text Available Abstract Background The development of large-scale gene expression profiling technologies is rapidly changing the norms of biological investigation. But the rapid pace of change itself presents challenges. Commercial microarrays are regularly modified to incorporate new genes and improved target sequences. Although the ability to compare datasets across generations is crucial for any long-term research project, to date no means to allow such comparisons have been developed. In this study the reproducibility of gene expression levels across two generations of Affymetrix GeneChips® (HuGeneFL and HG-U95A was measured. Results Correlation coefficients were computed for gene expression values across chip generations based on different measures of similarity. Comparing the absolute calls assigned to the individual probe sets across the generations found them to be largely unchanged. Conclusion We show that experimental replicates are highly reproducible, but that reproducibility across generations depends on the degree of similarity of the probe sets and the expression level of the corresponding transcript.

  11. Reproducibility of the Portuguese version of the PEDro Scale

    Directory of Open Access Journals (Sweden)

    Silvia Regina Shiwa

    2011-10-01

    Full Text Available The objective of this study was to test the inter-rater reproducibility of the Portuguese version of the PEDro Scale. Seven physiotherapists rated the methodological quality of 50 reports of randomized controlled trials written in Portuguese indexed on the PEDro database. Each report was also rated using the English version of the PEDro Scale. Reproducibility was evaluated by comparing two separate ratings of reports written in Portuguese and comparing the Portuguese PEDro score with the English version of the scale. Kappa coefficients ranged from 0.53 to 1.00 for individual item and an intraclass correlation coefficient (ICC of 0.82 for the total PEDro score was observed. The standard error of the measurement of the scale was 0.58. The Portuguese version of the scale was comparable with the English version, with an ICC of 0.78. The inter-rater reproducibility of the Brazilian Portuguese PEDro Scale is adequate and similar to the original English version.

  12. Can cancer researchers accurately judge whether preclinical reports will reproduce?

    Directory of Open Access Journals (Sweden)

    Daniel Benjamin

    2017-06-01

    Full Text Available There is vigorous debate about the reproducibility of research findings in cancer biology. Whether scientists can accurately assess which experiments will reproduce original findings is important to determining the pace at which science self-corrects. We collected forecasts from basic and preclinical cancer researchers on the first 6 replication studies conducted by the Reproducibility Project: Cancer Biology (RP:CB to assess the accuracy of expert judgments on specific replication outcomes. On average, researchers forecasted a 75% probability of replicating the statistical significance and a 50% probability of replicating the effect size, yet none of these studies successfully replicated on either criterion (for the 5 studies with results reported. Accuracy was related to expertise: experts with higher h-indices were more accurate, whereas experts with more topic-specific expertise were less accurate. Our findings suggest that experts, especially those with specialized knowledge, were overconfident about the RP:CB replicating individual experiments within published reports; researcher optimism likely reflects a combination of overestimating the validity of original studies and underestimating the difficulties of repeating their methodologies.

  13. On the origin of reproducible sequential activity in neural circuits

    Science.gov (United States)

    Afraimovich, V. S.; Zhigulin, V. P.; Rabinovich, M. I.

    2004-12-01

    Robustness and reproducibility of sequential spatio-temporal responses is an essential feature of many neural circuits in sensory and motor systems of animals. The most common mathematical images of dynamical regimes in neural systems are fixed points, limit cycles, chaotic attractors, and continuous attractors (attractive manifolds of neutrally stable fixed points). These are not suitable for the description of reproducible transient sequential neural dynamics. In this paper we present the concept of a stable heteroclinic sequence (SHS), which is not an attractor. SHS opens the way for understanding and modeling of transient sequential activity in neural circuits. We show that this new mathematical object can be used to describe robust and reproducible sequential neural dynamics. Using the framework of a generalized high-dimensional Lotka-Volterra model, that describes the dynamics of firing rates in an inhibitory network, we present analytical results on the existence of the SHS in the phase space of the network. With the help of numerical simulations we confirm its robustness in presence of noise in spite of the transient nature of the corresponding trajectories. Finally, by referring to several recent neurobiological experiments, we discuss possible applications of this new concept to several problems in neuroscience.

  14. Aveiro method in reproducing kernel Hilbert spaces under complete dictionary

    Science.gov (United States)

    Mai, Weixiong; Qian, Tao

    2017-12-01

    Aveiro Method is a sparse representation method in reproducing kernel Hilbert spaces (RKHS) that gives orthogonal projections in linear combinations of reproducing kernels over uniqueness sets. It, however, suffers from determination of uniqueness sets in the underlying RKHS. In fact, in general spaces, uniqueness sets are not easy to be identified, let alone the convergence speed aspect with Aveiro Method. To avoid those difficulties we propose an anew Aveiro Method based on a dictionary and the matching pursuit idea. What we do, in fact, are more: The new Aveiro method will be in relation to the recently proposed, the so called Pre-Orthogonal Greedy Algorithm (P-OGA) involving completion of a given dictionary. The new method is called Aveiro Method Under Complete Dictionary (AMUCD). The complete dictionary consists of all directional derivatives of the underlying reproducing kernels. We show that, under the boundary vanishing condition, bring available for the classical Hardy and Paley-Wiener spaces, the complete dictionary enables an efficient expansion of any given element in the Hilbert space. The proposed method reveals new and advanced aspects in both the Aveiro Method and the greedy algorithm.

  15. Validity and reproducibility of a Spanish dietary history.

    Directory of Open Access Journals (Sweden)

    Pilar Guallar-Castillón

    Full Text Available To assess the validity and reproducibility of food and nutrient intake estimated with the electronic diet history of ENRICA (DH-E, which collects information on numerous aspects of the Spanish diet.The validity of food and nutrient intake was estimated using Pearson correlation coefficients between the DH-E and the mean of seven 24-hour recalls collected every 2 months over the previous year. The reproducibility was estimated using intraclass correlation coefficients between two DH-E made one year apart.The correlations coefficients between the DH-E and the mean of seven 24-hour recalls for the main food groups were cereals (r = 0.66, meat (r = 0.66, fish (r = 0.42, vegetables (r = 0.62 and fruits (r = 0.44. The mean correlation coefficient for all 15 food groups considered was 0.53. The correlations for macronutrients were: energy (r = 0.76, proteins (r= 0.58, lipids (r = 0.73, saturated fat (r = 0.73, monounsaturated fat (r = 0.59, polyunsaturated fat (r = 0.57, and carbohydrates (r = 0.66. The mean correlation coefficient for all 41 nutrients studied was 0.55. The intraclass correlation coefficient between the two DH-E was greater than 0.40 for most foods and nutrients.The DH-E shows good validity and reproducibility for estimating usual intake of foods and nutrients.

  16. HiCRep: assessing the reproducibility of Hi-C data using a stratum-adjusted correlation coefficient.

    Science.gov (United States)

    Yang, Tao; Zhang, Feipeng; Yardımcı, Galip Gürkan; Song, Fan; Hardison, Ross C; Noble, William Stafford; Yue, Feng; Li, Qunhua

    2017-11-01

    Hi-C is a powerful technology for studying genome-wide chromatin interactions. However, current methods for assessing Hi-C data reproducibility can produce misleading results because they ignore spatial features in Hi-C data, such as domain structure and distance dependence. We present HiCRep, a framework for assessing the reproducibility of Hi-C data that systematically accounts for these features. In particular, we introduce a novel similarity measure, the stratum adjusted correlation coefficient (SCC), for quantifying the similarity between Hi-C interaction matrices. Not only does it provide a statistically sound and reliable evaluation of reproducibility, SCC can also be used to quantify differences between Hi-C contact matrices and to determine the optimal sequencing depth for a desired resolution. The measure consistently shows higher accuracy than existing approaches in distinguishing subtle differences in reproducibility and depicting interrelationships of cell lineages. The proposed measure is straightforward to interpret and easy to compute, making it well-suited for providing standardized, interpretable, automatable, and scalable quality control. The freely available R package HiCRep implements our approach. © 2017 Yang et al.; Published by Cold Spring Harbor Laboratory Press.

  17. Brazilian Portuguese translation, cross-cultural adaptation and reproducibility assessment of the modified Bristol Stool Form Scale for children.

    Science.gov (United States)

    Jozala, Debora Rodrigues; Oliveira, Isabelle Stefan de Faria; Ortolan, Erika Veruska Paiva; Oliveira Junior, Wilson Elias de; Comes, Giovana Tuccille; Cassettari, Vanessa Mello Granado; Self, Mariella Marie; Lourenção, Pedro Luiz Toledo de Arruda

    2018-03-15

    To translate and culturally adapt the modified Bristol Stool Form Scale for children into Brazilian Portuguese, and to evaluate the reproducibility of the translated version. The stage of translation and cross-cultural adaptation was performed according to an internationally accepted methodology, including the translation, back-translation, and pretest application of the translated version to a sample of 74 children to evaluate the degree of understanding. The reproducibility of the translated scale was assessed by applying the final version of Brazilian Portuguese modified Bristol Stool Form Scale for children to a sample of 64 children and 25 healthcare professionals, who were asked to correlate a randomly selected description from the translated scale with the corresponding representative illustration of the stool type. The final version of Brazilian Portuguese modified Bristol Stool Form Scale for children were evidently reproducible, since almost complete agreement (k>0,8) was obtained among the translated descriptions and illustrations of the stool types, both among the children and the group of specialists. The Brazilian Portuguese modified Bristol Stool Form Scale for children was shown to be reliable in providing very similar results for the same respondents at different times and for different examiners. The Brazilian Portuguese modified Bristol Stool Form Scale for children is reproducible; it can be applied in clinical practice and in scientific research in Brazil. Copyright © 2018 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  18. Reproducibility of urodynamic filling sensation at weekly interval in healthy volunteers and in women with detrusor overactivity.

    Science.gov (United States)

    Van Meel, Tom David; Wyndaele, Jean-Jacques

    2011-11-01

    To evaluate the reproducibility of bladder sensation during standardized filling cystometry in female volunteers and overactive bladder (OAB) patients, repeated with weekly interval. We recruited 13 female nulliparous volunteers (age 21-47) and 17 female patients with OAB between (age 18-72). They participated in three investigation periods, each separated by 7 days to assess reproducibility of sensation related to standardized cystometry. Subjects were asked to report all sensations they felt during bladder filling. The previously described pattern of sensation was reported during bladder filling in all. Consecutive sensations corresponded to statistically higher bladder volumes. Volumes, at which different sensations of bladder filling were reported, were significantly higher in controls than in OAB patients [first sensation of filling (FSF) P = 0.003, first desire to void (FDV) P sensation/volume ratios were significantly higher in patients with OAB than in the healthy volunteers: FSF occurred at mean 46% and FDV at mean 73% of SDV in OAB patients, compared to 36% and 64% in healthy volunteers. Sensations proved highly reproducible when determined with weekly interval. Our data demonstrate that cystometric filling sensation determined in a standardized way with weekly interval is highly reproducible in healthy and in OAB patients. This finding has, in our opinion, clinical importance as it shows that the technique is reliable both for a sensory evaluation of the LUT as to study influence of treatment aimed at changing this sensation. Copyright © 2011 Wiley Periodicals, Inc.

  19. Columbus safety and reliability

    Science.gov (United States)

    Longhurst, F.; Wessels, H.

    1988-10-01

    Analyses carried out to ensure Columbus reliability, availability, and maintainability, and operational and design safety are summarized. Failure modes/effects/criticality is the main qualitative tool used. The main aspects studied are fault tolerance, hazard consequence control, risk minimization, human error effects, restorability, and safe-life design.

  20. Power transformer reliability modelling

    NARCIS (Netherlands)

    Schijndel, van A.

    2010-01-01

    Problem description Electrical power grids serve to transport and distribute electrical power with high reliability and availability at acceptable costs and risks. These grids play a crucial though preferably invisible role in supplying sufficient power in a convenient form. Today’s society has

  1. Designing reliability into accelerators

    International Nuclear Information System (INIS)

    Hutton, A.

    1992-08-01

    For the next generation of high performance, high average luminosity colliders, the ''factories,'' reliability engineering must be introduced right at the inception of the project and maintained as a central theme throughout the project. There are several aspects which will be addressed separately: Concept; design; motivation; management techniques; and fault diagnosis

  2. Proof tests on reliability

    International Nuclear Information System (INIS)

    Mishima, Yoshitsugu

    1983-01-01

    In order to obtain public understanding on nuclear power plants, tests should be carried out to prove the reliability and safety of present LWR plants. For example, the aseismicity of nuclear power plants must be verified by using a large scale earthquake simulator. Reliability test began in fiscal 1975, and the proof tests on steam generators and on PWR support and flexure pins against stress corrosion cracking have already been completed, and the results have been internationally highly appreciated. The capacity factor of the nuclear power plant operation in Japan rose to 80% in the summer of 1983, and considering the period of regular inspection, it means the operation of almost full capacity. Japanese LWR technology has now risen to the top place in the world after having overcome the defects. The significance of the reliability test is to secure the functioning till the age limit is reached, to confirm the correct forecast of deteriorating process, to confirm the effectiveness of the remedy to defects and to confirm the accuracy of predicting the behavior of facilities. The reliability of nuclear valves, fuel assemblies, the heat affected zones in welding, reactor cooling pumps and electric instruments has been tested or is being tested. (Kako, I.)

  3. Reliability and code level

    NARCIS (Netherlands)

    Kasperski, M.; Geurts, C.P.W.

    2005-01-01

    The paper describes the work of the IAWE Working Group WBG - Reliability and Code Level, one of the International Codification Working Groups set up at ICWE10 in Copenhagen. The following topics are covered: sources of uncertainties in the design wind load, appropriate design target values for the

  4. Reliability of Plastic Slabs

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    1989-01-01

    In the paper it is shown how upper and lower bounds for the reliability of plastic slabs can be determined. For the fundamental case it is shown that optimal bounds of a deterministic and a stochastic analysis are obtained on the basis of the same failure mechanisms and the same stress fields....

  5. Reliability based structural design

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.

    2014-01-01

    According to ISO 2394, structures shall be designed, constructed and maintained in such a way that they are suited for their use during the design working life in an economic way. To fulfil this requirement one needs insight into the risk and reliability under expected and non-expected actions. A

  6. Travel time reliability modeling.

    Science.gov (United States)

    2011-07-01

    This report includes three papers as follows: : 1. Guo F., Rakha H., and Park S. (2010), "A Multi-state Travel Time Reliability Model," : Transportation Research Record: Journal of the Transportation Research Board, n 2188, : pp. 46-54. : 2. Park S.,...

  7. Reliability and Model Fit

    Science.gov (United States)

    Stanley, Leanne M.; Edwards, Michael C.

    2016-01-01

    The purpose of this article is to highlight the distinction between the reliability of test scores and the fit of psychometric measurement models, reminding readers why it is important to consider both when evaluating whether test scores are valid for a proposed interpretation and/or use. It is often the case that an investigator judges both the…

  8. Parametric Mass Reliability Study

    Science.gov (United States)

    Holt, James P.

    2014-01-01

    The International Space Station (ISS) systems are designed based upon having redundant systems with replaceable orbital replacement units (ORUs). These ORUs are designed to be swapped out fairly quickly, but some are very large, and some are made up of many components. When an ORU fails, it is replaced on orbit with a spare; the failed unit is sometimes returned to Earth to be serviced and re-launched. Such a system is not feasible for a 500+ day long-duration mission beyond low Earth orbit. The components that make up these ORUs have mixed reliabilities. Components that make up the most mass-such as computer housings, pump casings, and the silicon board of PCBs-typically are the most reliable. Meanwhile components that tend to fail the earliest-such as seals or gaskets-typically have a small mass. To better understand the problem, my project is to create a parametric model that relates both the mass of ORUs to reliability, as well as the mass of ORU subcomponents to reliability.

  9. Reliability of basal plasma vasopressin concentrations in healthy male adults.

    Science.gov (United States)

    Quintana, Daniel S; Westlye, Lars T; Smerud, Knut T; Mahmoud, Ramy A; Djupesland, Per G; Andreassen, Ole A

    2017-10-01

    The neuropeptides oxytocin (OT) and arginine vasopressin (AVP) play important and interrelated roles in modulating mammalian social behaviour. While the OT system has received considerable research attention for its potential to treat psychiatric symptoms, comparatively little is known about the role of the AVP system in human social behaviour. To better understand the intraindividual stability of basal AVP, the present study assessed the reproducibility of basal plasma AVP concentrations. Basal plasma AVP was assessed at four sampling points separated by 8 days, on average, in 16 healthy adult males. Only one out of six comparisons revealed strong evidence for reproducibility of basal AVP concentrations (visit 2 vs. visit 4: r=0.8, p0.1). The concordance correlation coefficient [0.15, 95% CI (-0.55, 0.73)] also revealed poor overall reproducibility. Poor reliability of basal AVP concentrations suggests future work covarying AVP with trait markers should proceed with careful consideration of intraindividual fluctuations.

  10. Reliability Approach of a Compressor System using Reliability Block ...

    African Journals Online (AJOL)

    pc

    2018-03-05

    Mar 5, 2018 ... This paper presents a reliability analysis of such a system using reliability ... Keywords-compressor system, reliability, reliability block diagram, RBD .... the same structure has been kept with the three subsystems: air flow, oil flow and .... and Safety in Engineering Design", Springer, 2009. [3] P. O'Connor ...

  11. Reliability and discriminatory power of methods for dental plaque quantification

    Directory of Open Access Journals (Sweden)

    Daniela Prócida Raggio

    2010-04-01

    Full Text Available OBJECTIVE: This in situ study evaluated the discriminatory power and reliability of methods of dental plaque quantification and the relationship between visual indices (VI and fluorescence camera (FC to detect plaque. MATERIAL AND METHODS: Six volunteers used palatal appliances with six bovine enamel blocks presenting different stages of plaque accumulation. The presence of plaque with and without disclosing was assessed using VI. Images were obtained with FC and digital camera in both conditions. The area covered by plaque was assessed. Examinations were done by two independent examiners. Data were analyzed by Kruskal-Wallis and Kappa tests to compare different conditions of samples and to assess the inter-examiner reproducibility. RESULTS: Some methods presented adequate reproducibility. The Turesky index and the assessment of area covered by disclosed plaque in the FC images presented the highest discriminatory powers. CONCLUSION: The Turesky index and images with FC with disclosing present good reliability and discriminatory power in quantifying dental plaque.

  12. Reliability in the utility computing era: Towards reliable Fog computing

    DEFF Research Database (Denmark)

    Madsen, Henrik; Burtschy, Bernard; Albeanu, G.

    2013-01-01

    This paper considers current paradigms in computing and outlines the most important aspects concerning their reliability. The Fog computing paradigm as a non-trivial extension of the Cloud is considered and the reliability of the networks of smart devices are discussed. Combining the reliability...... requirements of grid and cloud paradigms with the reliability requirements of networks of sensor and actuators it follows that designing a reliable Fog computing platform is feasible....

  13. Reproducibility of Single-Pulse, Paired-Pulse, and Intermittent Theta-Burst TMS Measures in Healthy Aging, Type-2 Diabetes, and Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Peter J. Fried

    2017-08-01

    Full Text Available Background: Transcranial magnetic stimulation (TMS can be used to assess neurophysiology and the mechanisms of cortical brain plasticity in humans in vivo. As the use of these measures in specific populations (e.g., Alzheimer’s disease; AD increases, it is critical to understand their reproducibility (i.e., test–retest reliability in the populations of interest.Objective: Reproducibility of TMS measures was evaluated in older adults, including healthy, AD, and Type-2 diabetes mellitus (T2DM groups.Methods: Participants received two identical neurophysiological assessments within a year including motor thresholds, baseline motor evoked potentials (MEPs, short- and long-interval intracortical inhibition (SICI, LICI and intracortical facilitation (ICF, and MEP changes following intermittent theta-burst stimulation (iTBS. Cronbach’s α coefficients were calculated to assess reproducibility. Multiple linear regression analyses were used to investigate factors related to intraindividual variability.Results: Reproducibility was highest for motor thresholds, followed by baseline MEPs, SICI and LICI, and was lowest for ICF and iTBS aftereffects. The AD group tended to show higher reproducibility than T2DM or controls. Intraindividual variability of baseline MEPs was related to age and variability of RMT, while the intraindividual variability in post-iTBS measures was related to baseline MEP variability, intervisit duration, and Brain-derived neurotrophic factor (BDNF polymorphism.Conclusion: Increased reproducibility in AD may reflect pathophysiological declines in the efficacy of neuroplastic mechanisms. Reproducibility of iTBS aftereffects can be improved by keeping baseline MEPs consistent, controlling for BDNF genotype, and waiting at least a week between visits.Significance: These findings provide the first direct assessment of reproducibility of TMS measures in older clinical populations. Reproducibility coefficients may be used to adjust

  14. Sensitivity analysis in a structural reliability context

    International Nuclear Information System (INIS)

    Lemaitre, Paul

    2014-01-01

    This thesis' subject is sensitivity analysis in a structural reliability context. The general framework is the study of a deterministic numerical model that allows to reproduce a complex physical phenomenon. The aim of a reliability study is to estimate the failure probability of the system from the numerical model and the uncertainties of the inputs. In this context, the quantification of the impact of the uncertainty of each input parameter on the output might be of interest. This step is called sensitivity analysis. Many scientific works deal with this topic but not in the reliability scope. This thesis' aim is to test existing sensitivity analysis methods, and to propose more efficient original methods. A bibliographical step on sensitivity analysis on one hand and on the estimation of small failure probabilities on the other hand is first proposed. This step raises the need to develop appropriate techniques. Two variables ranking methods are then explored. The first one proposes to make use of binary classifiers (random forests). The second one measures the departure, at each step of a subset method, between each input original density and the density given the subset reached. A more general and original methodology reflecting the impact of the input density modification on the failure probability is then explored. The proposed methods are then applied on the CWNR case, which motivates this thesis. (author)

  15. Validity and reproducibility of the Physical Activity Scale for the Elderly (PASE) questionnaire for the measurement of the physical activity level in patients after total knee arthroplasty.

    Science.gov (United States)

    Bolszak, Sylvain; Casartelli, Nicola C; Impellizzeri, Franco M; Maffiuletti, Nicola A

    2014-02-20

    The need for valid and reproducible questionnaires to routinely assess the physical activity level of patients after total knee arthroplasty (TKA) is of particular concern in clinical settings. Aims of this study were to evaluate the validity and reproducibility of the physical activity scale for the elderly (PASE) questionnaire in TKA patients, with a particular view on gender differences. A total of 50 elderly patients (25 women and 25 men aged 70 ± 6 years) following primary unilateral TKA were recruited. The reproducibility was evaluated by administering the PASE questionnaire during two occasions separated by 7 days. The construct (criterion) validity was investigated by comparing the physical activity level reported by patients in the PASE questionnaire to that measured by accelerometry. Reproducibility was evaluated using intraclass correlation coefficients (ICC3,1) for reliability and standard error of measurement (SEM) and smallest detectable change (SDC) for agreement, while validity was investigated with Pearson correlation coefficients. Reliability of the PASE total score was acceptable for men (ICC = 0.77) but not for women (ICC = 0.58). Its agreement was low for both men and women, as witnessed by high SEM (32% and 35%, respectively) and SDC (89% and 97%, respectively). Construct validity of the PASE total score was low in both men (r = 0.45) and women (r = 0.06). The PASE questionnaire has several validity and reproducibility shortcomings, therefore its use is not recommended for the assessment of physical activity level in patients after TKA, particularly in women.

  16. The web-based ASSO-food frequency questionnaire for adolescents: relative and absolute reproducibility assessment.

    Science.gov (United States)

    Filippi, Anna Rita; Amodio, Emanuele; Napoli, Giuseppe; Breda, João; Bianco, Antonino; Jemni, Monèm; Censi, Laura; Mammina, Caterina; Tabacchi, Garden

    2014-12-17

    A new food frequency questionnaire (FFQ) has been recently developed within the Italian Adolescents and Surveillance System for the Obesity prevention (ASSO) Project; it was found to be appropriate for ranking adolescents in food and nutrient levels of intake. The aim of this study was to assess the relative and absolute reproducibility of the ASSO-FFQ for 24 food groups, energy and 52 nutrients. A test-retest study was performed on two ASSO-FFQs administered one month apart of each other to 185 adolescents, aged 14-17 and attending secondary schools in Palermo (Italy). Wilcoxon test assessed differences in median daily intakes between the two FFQs. Agreement was evaluated by quintiles comparison and weighted kappa. Intraclass Correlation Coefficients (ICC) and Bland-Altman method assessed the relative and absolute reliability respectively. Significant difference (p food, water, soft drinks, carbohydrates and sugar. The subjects classified into the same or adjacent quintiles for food groups ranged from 62% (white bread) to 91% (soft drinks); for energy and nutrients from 64% (polyunsaturated fatty acids) to 90% (ethanol). Mean values of weighted kappa were 0.47 and 0.48, respectively for food groups and nutrients. Fair to good ICC values (>0.40) were assessed for thirteen food groups, energy and forty-three nutrients. Limits of Agreement were narrow for almost all food groups and all nutrients. The ASSO-FFQ is a reliable instrument for estimating food groups, energy and nutrients intake in adolescents.

  17. RTE - Reliability report 2016

    International Nuclear Information System (INIS)

    2017-06-01

    Every year, RTE produces a reliability report for the past year. This document lays out the main factors that affected the electrical power system's operational reliability in 2016 and the initiatives currently under way intended to ensure its reliability in the future. Within a context of the energy transition, changes to the European interconnected network mean that RTE has to adapt on an on-going basis. These changes include the increase in the share of renewables injecting an intermittent power supply into networks, resulting in a need for flexibility, and a diversification in the numbers of stakeholders operating in the energy sector and changes in the ways in which they behave. These changes are dramatically changing the structure of the power system of tomorrow and the way in which it will operate - particularly the way in which voltage and frequency are controlled, as well as the distribution of flows, the power system's stability, the level of reserves needed to ensure supply-demand balance, network studies, assets' operating and control rules, the tools used and the expertise of operators. The results obtained in 2016 are evidence of a globally satisfactory level of reliability for RTE's operations in somewhat demanding circumstances: more complex supply-demand balance management, cross-border schedules at interconnections indicating operation that is closer to its limits and - most noteworthy - having to manage a cold spell just as several nuclear power plants had been shut down. In a drive to keep pace with the changes expected to occur in these circumstances, RTE implemented numerous initiatives to ensure high levels of reliability: - maintaining investment levels of euro 1.5 billion per year; - increasing cross-zonal capacity at borders with our neighbouring countries, thus bolstering the security of our electricity supply; - implementing new mechanisms (demand response, capacity mechanism, interruptibility, etc.); - involvement in tests or projects

  18. Disposable Collection Kit for Rapid and Reliable Collection of Saliva

    OpenAIRE

    Yamaguchi, Masaki; Tezuka, Yuki; Takeda, Kazunori; Shetty, Vivek

    2015-01-01

    Objectives To describe and evaluate disposable saliva collection kit for rapid, reliable, and reproducible collection of saliva samples. Methods The saliva collection kit comprised of a saliva absorbent swab and an extractor unit was used to retrieve whole saliva samples from 10 subjects. The accuracy and precision of the extracted volumes (3, 10, and 30 ?l) were compared to similar volumes drawn from control samples obtained by passive drool. Additionally, the impact of kit collection method...

  19. Efficient and reproducible mammalian cell bioprocesses without probes and controllers?

    Science.gov (United States)

    Tissot, Stéphanie; Oberbek, Agata; Reclari, Martino; Dreyer, Matthieu; Hacker, David L; Baldi, Lucia; Farhat, Mohamed; Wurm, Florian M

    2011-07-01

    Bioprocesses for recombinant protein production with mammalian cells are typically controlled for several physicochemical parameters including the pH and dissolved oxygen concentration (DO) of the culture medium. Here we studied whether these controls are necessary for efficient and reproducible bioprocesses in an orbitally shaken bioreactor (OSR). Mixing, gas transfer, and volumetric power consumption (P(V)) were determined in both a 5-L OSR and a 3-L stirred-tank bioreactor (STR). The two cultivation systems had a similar mixing intensity, but the STR had a lower volumetric mass transfer coefficient of oxygen (k(L)a) and a higher P(V) than the OSR. Recombinant CHO cell lines expressing either tumor necrosis factor receptor as an Fc fusion protein (TNFR:Fc) or an anti-RhesusD monoclonal antibody were cultivated in the two systems. The 5-L OSR was operated in an incubator shaker with 5% CO(2) in the gas environment but without pH and DO control whereas the STR was operated with or without pH and DO control. Higher cell densities and recombinant protein titers were obtained in the OSR as compared to both the controlled and the non-controlled STRs. To test the reproducibility of a bioprocess in a non-controlled OSR, the two CHO cell lines were each cultivated in parallel in six 5-L OSRs. Similar cell densities, cell viabilities, and recombinant protein titers along with similar pH and DO profiles were achieved in each group of replicates. Our study demonstrated that bioprocesses can be performed in OSRs without pH or DO control in a highly reproducible manner, at least at the scale of operation studied here. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. REPRODUCIBILITY OF MASKED HYPERTENSION AMONG ADULTS 30 YEARS AND OLDER

    Science.gov (United States)

    Viera, Anthony J.; Lin, Feng-Chang; Tuttle, Laura A.; Olsson, Emily; Stankevitz, Kristin; Girdler, Susan S.; Klein, J. Larry; Hinderliter, Alan L.

    2015-01-01

    Objective Masked hypertension (MH) refers to non-elevated office blood pressure (BP) with elevated out-of-office BP, but its reproducibility has not been conclusively established. We examined one-week reproducibility of MH by home BP monitoring (HBPM) and ambulatory BP monitoring (ABPM). Methods We recruited 420 adults not on BP-lowering medication with recent clinic BP between 120/80 and 149/95 mm Hg. For main comparisons, participants with office average ABPM average was ≥135/85 mm Hg; they were considered to have MH by HBPM if the average was ≥135/85 mm Hg. Percent agreements were quantified using kappa. We also examined prevalence of MH defined as office average ABPM average ≥130/80 mm Hg. We conducted sensitivity analyses using different threshold BP levels for ABPM-office pairings and HBPM-office pairings for defining MH. Results Prevalence rates of MH based on office-awake ABPM pairings were 44% and 43%, with agreement of 71% (kappa=0.40; 95% CI 0.31–0.49). MH was less prevalent (15% and 17%) using HBPM-office pairings, with agreement of 82% (kappa=0.30; 95% CI 0.16–0.44), and more prevalent when considering 24-hour average (50% and 48%). MH was also less prevalent when more stringent diagnostic criteria were applied. Office-HBPM pairings and office-awake ABPM pairings had fair agreement on MH classification on both occasions, with kappas of 0.36 and 0.30. Conclusions MH has fair short-term reproducibility, providing further evidence that for some people, out-of-office BP is systematically higher than when measured in the office setting. PMID:24842491

  1. Reproducibility of an aerobic endurance test for nonexpert swimmers.

    Science.gov (United States)

    Veronese da Costa, Adalberto; Costa, Manoel da Cunha; Carlos, Daniel Medeiros; Guerra, Luis Marcos de Medeiros; Silva, Antônio José; Barbosa, Tiago Manoel Cabral Dos Santos

    2012-01-01

    This study aimed to verify the reproduction of an aerobic test to determine nonexpert swimmers' resistance. The sample consisted of 24 male swimmers (age: 22.79 ± 3.90 years; weight: 74.72 ± 11.44 kg; height: 172.58 ± 4.99 cm; and fat percentage: 15.19% ± 3.21%), who swim for 1 hour three times a week. A new instrument was used in this study (a Progressive Swim Test): the swimmer wore an underwater MP3 player and increased their swimming speed on hearing a beep after every 25 meters. Each swimmer's heart rate was recorded before the test (BHR) and again after the test (AHR). The rate of perceived exertion (RPE) and the number of laps performed (NLP) were also recorded. The sample size was estimated using G*Power software (v 3.0.10; Franz Faul, Kiel University, Kiel, Germany). The descriptive values were expressed as mean and standard deviation. After confirming the normality of the data using both the Shapiro-Wilk and Levene tests, a paired t-test was performed to compare the data. The Pearson's linear correlation (r) and intraclass coefficient correlation (ICC) tests were used to determine relative reproducibility. The standard error of measurement (SEM) and the coefficient of variation (CV) were used to determine absolute reproducibility. The limits of agreement and the bias of the absolute and relative values between days were determined by Bland-Altman plots. All values had a significance level of P 0.50 and ICC > 0.66. The SEM had a variation of ±2% and the CV was 0.90; SEM swimmers. The Progressive Swim Test for nonexpert swimmers produces comparable results for noncompetitive swimmers with a favorable degree of reproducibility, thus presenting possible applications for researching the physiological performance of nonexpert swimmers.

  2. Reproducibility and Transparency in Ocean-Climate Modeling

    Science.gov (United States)

    Hannah, N.; Adcroft, A.; Hallberg, R.; Griffies, S. M.

    2015-12-01

    Reproducibility is a cornerstone of the scientific method. Within geophysical modeling and simulation achieving reproducibility can be difficult, especially given the complexity of numerical codes, enormous and disparate data sets, and variety of supercomputing technology. We have made progress on this problem in the context of a large project - the development of new ocean and sea ice models, MOM6 and SIS2. Here we present useful techniques and experience.We use version control not only for code but the entire experiment working directory, including configuration (run-time parameters, component versions), input data and checksums on experiment output. This allows us to document when the solutions to experiments change, whether due to code updates or changes in input data. To avoid distributing large input datasets we provide the tools for generating these from the sources, rather than provide raw input data.Bugs can be a source of non-determinism and hence irreproducibility, e.g. reading from or branching on uninitialized memory. To expose these we routinely run system tests, using a memory debugger, multiple compilers and different machines. Additional confidence in the code comes from specialised tests, for example automated dimensional analysis and domain transformations. This has entailed adopting a code style where we deliberately restrict what a compiler can do when re-arranging mathematical expressions.In the spirit of open science, all development is in the public domain. This leads to a positive feedback, where increased transparency and reproducibility makes using the model easier for external collaborators, who in turn provide valuable contributions. To facilitate users installing and running the model we provide (version controlled) digital notebooks that illustrate and record analysis of output. This has the dual role of providing a gross, platform-independent, testing capability and a means to documents model output and analysis.

  3. Repeatability and reproducibility of decisions by latent fingerprint examiners.

    Directory of Open Access Journals (Sweden)

    Bradford T Ulery

    Full Text Available The interpretation of forensic fingerprint evidence relies on the expertise of latent print examiners. We tested latent print examiners on the extent to which they reached consistent decisions. This study assessed intra-examiner repeatability by retesting 72 examiners on comparisons of latent and exemplar fingerprints, after an interval of approximately seven months; each examiner was reassigned 25 image pairs for comparison, out of total pool of 744 image pairs. We compare these repeatability results with reproducibility (inter-examiner results derived from our previous study. Examiners repeated 89.1% of their individualization decisions, and 90.1% of their exclusion decisions; most of the changed decisions resulted in inconclusive decisions. Repeatability of comparison decisions (individualization, exclusion, inconclusive was 90.0% for mated pairs, and 85.9% for nonmated pairs. Repeatability and reproducibility were notably lower for comparisons assessed by the examiners as "difficult" than for "easy" or "moderate" comparisons, indicating that examiners' assessments of difficulty may be useful for quality assurance. No false positive errors were repeated (n = 4; 30% of false negative errors were repeated. One percent of latent value decisions were completely reversed (no value even for exclusion vs. of value for individualization. Most of the inter- and intra-examiner variability concerned whether the examiners considered the information available to be sufficient to reach a conclusion; this variability was concentrated on specific image pairs such that repeatability and reproducibility were very high on some comparisons and very low on others. Much of the variability appears to be due to making categorical decisions in borderline cases.

  4. Cyberinfrastructure to Support Collaborative and Reproducible Computational Hydrologic Modeling

    Science.gov (United States)

    Goodall, J. L.; Castronova, A. M.; Bandaragoda, C.; Morsy, M. M.; Sadler, J. M.; Essawy, B.; Tarboton, D. G.; Malik, T.; Nijssen, B.; Clark, M. P.; Liu, Y.; Wang, S. W.

    2017-12-01

    Creating cyberinfrastructure to support reproducibility of computational hydrologic models is an important research challenge. Addressing this challenge requires open and reusable code and data with machine and human readable metadata, organized in ways that allow others to replicate results and verify published findings. Specific digital objects that must be tracked for reproducible computational hydrologic modeling include (1) raw initial datasets, (2) data processing scripts used to clean and organize the data, (3) processed model inputs, (4) model results, and (5) the model code with an itemization of all software dependencies and computational requirements. HydroShare is a cyberinfrastructure under active development designed to help users store, share, and publish digital research products in order to improve reproducibility in computational hydrology, with an architecture supporting hydrologic-specific resource metadata. Researchers can upload data required for modeling, add hydrology-specific metadata to these resources, and use the data directly within HydroShare.org for collaborative modeling using tools like CyberGIS, Sciunit-CLI, and JupyterHub that have been integrated with HydroShare to run models using notebooks, Docker containers, and cloud resources. Current research aims to implement the Structure For Unifying Multiple Modeling Alternatives (SUMMA) hydrologic model within HydroShare to support hypothesis-driven hydrologic modeling while also taking advantage of the HydroShare cyberinfrastructure. The goal of this integration is to create the cyberinfrastructure that supports hypothesis-driven model experimentation, education, and training efforts by lowering barriers to entry, reducing the time spent on informatics technology and software development, and supporting collaborative research within and across research groups.

  5. On weights which admit the reproducing kernel of Bergman type

    Directory of Open Access Journals (Sweden)

    Zbigniew Pasternak-Winiarski

    1992-01-01

    Full Text Available In this paper we consider (1 the weights of integration for which the reproducing kernel of the Bergman type can be defined, i.e., the admissible weights, and (2 the kernels defined by such weights. It is verified that the weighted Bergman kernel has the analogous properties as the classical one. We prove several sufficient conditions and necessary and sufficient conditions for a weight to be an admissible weight. We give also an example of a weight which is not of this class. As a positive example we consider the weight μ(z=(Imz2 defined on the unit disk in ℂ.

  6. Ratio-scaling of listener preference of multichannel reproduced sound

    DEFF Research Database (Denmark)

    Choisel, Sylvain; Wickelmaier, Florian

    2005-01-01

    -trivial assumption in the case of complex spatial sounds. In the present study the Bradley-Terry-Luce (BTL) model was employed to investigate the unidimensionality of preference judgments made by 40 listeners on multichannel reproduced sound. Short musical excerpts played back in eight reproduction modes (mono...... music). As a main result, the BTL model was found to predict the choice frequencies well. This implies that listeners were able to integrate the complex nature of the sounds into a unidimensional preference judgment. It further implies the existence of a preference scale on which the reproduction modes...

  7. Towards interoperable and reproducible QSAR analyses: Exchange of datasets.

    Science.gov (United States)

    Spjuth, Ola; Willighagen, Egon L; Guha, Rajarshi; Eklund, Martin; Wikberg, Jarl Es

    2010-06-30

    QSAR is a widely used method to relate chemical structures to responses or properties based on experimental observations. Much effort has been made to evaluate and validate the statistical modeling in QSAR, but these analyses treat the dataset as fixed. An overlooked but highly important issue is the validation of the setup of the dataset, which comprises addition of chemical structures as well as selection of descriptors and software implementations prior to calculations. This process is hampered by the lack of standards and exchange formats in the field, making it virtually impossible to reproduce and validate analyses and drastically constrain collaborations and re-use of data. We present a step towards standardizing QSAR analyses by defining interoperable and reproducible QSAR datasets, consisting of an open XML format (QSAR-ML) which builds on an open and extensible descriptor ontology. The ontology provides an extensible way of uniquely defining descriptors for use in QSAR experiments, and the exchange format supports multiple versioned implementations of these descriptors. Hence, a dataset described by QSAR-ML makes its setup completely reproducible. We also provide a reference implementation as a set of plugins for Bioclipse which simplifies setup of QSAR datasets, and allows for exporting in QSAR-ML as well as old-fashioned CSV formats. The implementation facilitates addition of new descriptor implementations from locally installed software and remote Web services; the latter is demonstrated with REST and XMPP Web services. Standardized QSAR datasets open up new ways to store, query, and exchange data for subsequent analyses. QSAR-ML supports completely reproducible creation of datasets, solving the problems of defining which software components were used and their versions, and the descriptor ontology eliminates confusions regarding descriptors by defining them crisply. This makes is easy to join, extend, combine datasets and hence work collectively, but

  8. Towards interoperable and reproducible QSAR analyses: Exchange of datasets

    Directory of Open Access Journals (Sweden)

    Spjuth Ola

    2010-06-01

    Full Text Available Abstract Background QSAR is a widely used method to relate chemical structures to responses or properties based on experimental observations. Much effort has been made to evaluate and validate the statistical modeling in QSAR, but these analyses treat the dataset as fixed. An overlooked but highly important issue is the validation of the setup of the dataset, which comprises addition of chemical structures as well as selection of descriptors and software implementations prior to calculations. This process is hampered by the lack of standards and exchange formats in the field, making it virtually impossible to reproduce and validate analyses and drastically constrain collaborations and re-use of data. Results We present a step towards standardizing QSAR analyses by defining interoperable and reproducible QSAR datasets, consisting of an open XML format (QSAR-ML which builds on an open and extensible descriptor ontology. The ontology provides an extensible way of uniquely defining descriptors for use in QSAR experiments, and the exchange format supports multiple versioned implementations of these descriptors. Hence, a dataset described by QSAR-ML makes its setup completely reproducible. We also provide a reference implementation as a set of plugins for Bioclipse which simplifies setup of QSAR datasets, and allows for exporting in QSAR-ML as well as old-fashioned CSV formats. The implementation facilitates addition of new descriptor implementations from locally installed software and remote Web services; the latter is demonstrated with REST and XMPP Web services. Conclusions Standardized QSAR datasets open up new ways to store, query, and exchange data for subsequent analyses. QSAR-ML supports completely reproducible creation of datasets, solving the problems of defining which software components were used and their versions, and the descriptor ontology eliminates confusions regarding descriptors by defining them crisply. This makes is easy to join

  9. Explicit signal to noise ratio in reproducing kernel Hilbert spaces

    DEFF Research Database (Denmark)

    Gomez-Chova, Luis; Nielsen, Allan Aasbjerg; Camps-Valls, Gustavo

    2011-01-01

    This paper introduces a nonlinear feature extraction method based on kernels for remote sensing data analysis. The proposed approach is based on the minimum noise fraction (MNF) transform, which maximizes the signal variance while also minimizing the estimated noise variance. We here propose...... an alternative kernel MNF (KMNF) in which the noise is explicitly estimated in the reproducing kernel Hilbert space. This enables KMNF dealing with non-linear relations between the noise and the signal features jointly. Results show that the proposed KMNF provides the most noise-free features when confronted...

  10. Waste package reliability analysis

    International Nuclear Information System (INIS)

    Pescatore, C.; Sastre, C.

    1983-01-01

    Proof of future performance of a complex system such as a high-level nuclear waste package over a period of hundreds to thousands of years cannot be had in the ordinary sense of the word. The general method of probabilistic reliability analysis could provide an acceptable framework to identify, organize, and convey the information necessary to satisfy the criterion of reasonable assurance of waste package performance according to the regulatory requirements set forth in 10 CFR 60. General principles which may be used to evaluate the qualitative and quantitative reliability of a waste package design are indicated and illustrated with a sample calculation of a repository concept in basalt. 8 references, 1 table

  11. Accelerator reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, L; Duru, Ph; Koch, J M; Revol, J L; Van Vaerenbergh, P; Volpe, A M; Clugnet, K; Dely, A; Goodhew, D

    2002-07-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop.

  12. Human Reliability Program Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Landers, John; Rogers, Erin; Gerke, Gretchen

    2014-05-18

    A Human Reliability Program (HRP) is designed to protect national security as well as worker and public safety by continuously evaluating the reliability of those who have access to sensitive materials, facilities, and programs. Some elements of a site HRP include systematic (1) supervisory reviews, (2) medical and psychological assessments, (3) management evaluations, (4) personnel security reviews, and (4) training of HRP staff and critical positions. Over the years of implementing an HRP, the Department of Energy (DOE) has faced various challenges and overcome obstacles. During this 4-day activity, participants will examine programs that mitigate threats to nuclear security and the insider threat to include HRP, Nuclear Security Culture (NSC) Enhancement, and Employee Assistance Programs. The focus will be to develop an understanding of the need for a systematic HRP and to discuss challenges and best practices associated with mitigating the insider threat.

  13. Reliability and construction control

    Directory of Open Access Journals (Sweden)

    Sherif S. AbdelSalam

    2016-06-01

    Full Text Available The goal of this study was to determine the most reliable and efficient combination of design and construction methods required for vibro piles. For a wide range of static and dynamic formulas, the reliability-based resistance factors were calculated using EGYPT database, which houses load test results for 318 piles. The analysis was extended to introduce a construction control factor that determines the variation between the pile nominal capacities calculated using static versus dynamic formulae. From the major outcomes, the lowest coefficient of variation is associated with Davisson’s criterion, and the resistance factors calculated for the AASHTO method are relatively high compared with other methods. Additionally, the CPT-Nottingham and Schmertmann method provided the most economic design. Recommendations related to a pile construction control factor were also presented, and it was found that utilizing the factor can significantly reduce variations between calculated and actual capacities.

  14. Scyllac equipment reliability analysis

    International Nuclear Information System (INIS)

    Gutscher, W.D.; Johnson, K.J.

    1975-01-01

    Most of the failures in Scyllac can be related to crowbar trigger cable faults. A new cable has been designed, procured, and is currently undergoing evaluation. When the new cable has been proven, it will be worked into the system as quickly as possible without causing too much additional down time. The cable-tip problem may not be easy or even desirable to solve. A tightly fastened permanent connection that maximizes contact area would be more reliable than the plug-in type of connection in use now, but it would make system changes and repairs much more difficult. The balance of the failures have such a low occurrence rate that they do not cause much down time and no major effort is underway to eliminate them. Even though Scyllac was built as an experimental system and has many thousands of components, its reliability is very good. Because of this the experiment has been able to progress at a reasonable pace

  15. Improving Power Converter Reliability

    DEFF Research Database (Denmark)

    Ghimire, Pramod; de Vega, Angel Ruiz; Beczkowski, Szymon

    2014-01-01

    of a high-power IGBT module during converter operation, which may play a vital role in improving the reliability of the power converters. The measured voltage is used to estimate the module average junction temperature of the high and low-voltage side of a half-bridge IGBT separately in every fundamental......The real-time junction temperature monitoring of a high-power insulated-gate bipolar transistor (IGBT) module is important to increase the overall reliability of power converters for industrial applications. This article proposes a new method to measure the on-state collector?emitter voltage...... is measured in a wind power converter at a low fundamental frequency. To illustrate more, the test method as well as the performance of the measurement circuit are also presented. This measurement is also useful to indicate failure mechanisms such as bond wire lift-off and solder layer degradation...

  16. Accelerator reliability workshop

    International Nuclear Information System (INIS)

    Hardy, L.; Duru, Ph.; Koch, J.M.; Revol, J.L.; Van Vaerenbergh, P.; Volpe, A.M.; Clugnet, K.; Dely, A.; Goodhew, D.

    2002-01-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop

  17. Safety and reliability assessment

    International Nuclear Information System (INIS)

    1979-01-01

    This report contains the papers delivered at the course on safety and reliability assessment held at the CSIR Conference Centre, Scientia, Pretoria. The following topics were discussed: safety standards; licensing; biological effects of radiation; what is a PWR; safety principles in the design of a nuclear reactor; radio-release analysis; quality assurance; the staffing, organisation and training for a nuclear power plant project; event trees, fault trees and probability; Automatic Protective Systems; sources of failure-rate data; interpretation of failure data; synthesis and reliability; quantification of human error in man-machine systems; dispersion of noxious substances through the atmosphere; criticality aspects of enrichment and recovery plants; and risk and hazard analysis. Extensive examples are given as well as case studies

  18. Reliability of Circumplex Axes

    Directory of Open Access Journals (Sweden)

    Micha Strack

    2013-06-01

    Full Text Available We present a confirmatory factor analysis (CFA procedure for computing the reliability of circumplex axes. The tau-equivalent CFA variance decomposition model estimates five variance components: general factor, axes, scale-specificity, block-specificity, and item-specificity. Only the axes variance component is used for reliability estimation. We apply the model to six circumplex types and 13 instruments assessing interpersonal and motivational constructs—Interpersonal Adjective List (IAL, Interpersonal Adjective Scales (revised; IAS-R, Inventory of Interpersonal Problems (IIP, Impact Messages Inventory (IMI, Circumplex Scales of Interpersonal Values (CSIV, Support Action Scale Circumplex (SAS-C, Interaction Problems With Animals (IPI-A, Team Role Circle (TRC, Competing Values Leadership Instrument (CV-LI, Love Styles, Organizational Culture Assessment Instrument (OCAI, Customer Orientation Circle (COC, and System for Multi-Level Observation of Groups (behavioral adjectives; SYMLOG—in 17 German-speaking samples (29 subsamples, grouped by self-report, other report, and metaperception assessments. The general factor accounted for a proportion ranging from 1% to 48% of the item variance, the axes component for 2% to 30%; and scale specificity for 1% to 28%, respectively. Reliability estimates varied considerably from .13 to .92. An application of the Nunnally and Bernstein formula proposed by Markey, Markey, and Tinsley overestimated axes reliabilities in cases of large-scale specificities but otherwise works effectively. Contemporary circumplex evaluations such as Tracey’s RANDALL are sensitive to the ratio of the axes and scale-specificity components. In contrast, the proposed model isolates both components.

  19. The cost of reliability

    International Nuclear Information System (INIS)

    Ilic, M.

    1998-01-01

    In this article the restructuring process under way in the US power industry is being revisited from the point of view of transmission system provision and reliability was rolled into the average cost of electricity to all, it is not so obvious how is this cost managed in the new industry. A new MIT approach to transmission pricing is here suggested as a possible solution [it

  20. Software reliability studies

    Science.gov (United States)

    Hoppa, Mary Ann; Wilson, Larry W.

    1994-01-01

    There are many software reliability models which try to predict future performance of software based on data generated by the debugging process. Our research has shown that by improving the quality of the data one can greatly improve the predictions. We are working on methodologies which control some of the randomness inherent in the standard data generation processes in order to improve the accuracy of predictions. Our contribution is twofold in that we describe an experimental methodology using a data structure called the debugging graph and apply this methodology to assess the robustness of existing models. The debugging graph is used to analyze the effects of various fault recovery orders on the predictive accuracy of several well-known software reliability algorithms. We found that, along a particular debugging path in the graph, the predictive performance of different models can vary greatly. Similarly, just because a model 'fits' a given path's data well does not guarantee that the model would perform well on a different path. Further we observed bug interactions and noted their potential effects on the predictive process. We saw that not only do different faults fail at different rates, but that those rates can be affected by the particular debugging stage at which the rates are evaluated. Based on our experiment, we conjecture that the accuracy of a reliability prediction is affected by the fault recovery order as well as by fault interaction.

  1. Investment in new product reliability

    International Nuclear Information System (INIS)

    Murthy, D.N.P.; Rausand, M.; Virtanen, S.

    2009-01-01

    Product reliability is of great importance to both manufacturers and customers. Building reliability into a new product is costly, but the consequences of inadequate product reliability can be costlier. This implies that manufacturers need to decide on the optimal investment in new product reliability by achieving a suitable trade-off between the two costs. This paper develops a framework and proposes an approach to help manufacturers decide on the investment in new product reliability.

  2. Reproducibility of Dual-Microphone Voice Range Profile Equipment

    DEFF Research Database (Denmark)

    Printz, Trine; Pedersen, Ellen Raben; Juhl, Peter

    2017-01-01

    in an anechoic chamber and an office: (a) comparing sound pressure levels (SPLs) from a dual-microphone VRP device, the Voice Profiler, when given the same input repeatedly (test-retest reliability); (b) comparing SPLs from 3 devices when given the same input repeatedly (intervariation); and (c) assessing...

  3. Automated reliability assessment for spectroscopic redshift measurements

    Science.gov (United States)

    Jamal, S.; Le Brun, V.; Le Fèvre, O.; Vibert, D.; Schmitt, A.; Surace, C.; Copin, Y.; Garilli, B.; Moresco, M.; Pozzetti, L.

    2018-03-01

    Context. Future large-scale surveys, such as the ESA Euclid mission, will produce a large set of galaxy redshifts (≥106) that will require fully automated data-processing pipelines to analyze the data, extract crucial information and ensure that all requirements are met. A fundamental element in these pipelines is to associate to each galaxy redshift measurement a quality, or reliability, estimate. Aim. In this work, we introduce a new approach to automate the spectroscopic redshift reliability assessment based on machine learning (ML) and characteristics of the redshift probability density function. Methods: We propose to rephrase the spectroscopic redshift estimation into a Bayesian framework, in order to incorporate all sources of information and uncertainties related to the redshift estimation process and produce a redshift posterior probability density function (PDF). To automate the assessment of a reliability flag, we exploit key features in the redshift posterior PDF and machine learning algorithms. Results: As a working example, public data from the VIMOS VLT Deep Survey is exploited to present and test this new methodology. We first tried to reproduce the existing reliability flags using supervised classification in order to describe different types of redshift PDFs, but due to the subjective definition of these flags (classification accuracy 58%), we soon opted for a new homogeneous partitioning of the data into distinct clusters via unsupervised classification. After assessing the accuracy of the new clusters via resubstitution and test predictions (classification accuracy 98%), we projected unlabeled data from preliminary mock simulations for the Euclid space mission into this mapping to predict their redshift reliability labels. Conclusions: Through the development of a methodology in which a system can build its own experience to assess the quality of a parameter, we are able to set a preliminary basis of an automated reliability assessment for

  4. Highly Efficient and Reproducible Nonfullerene Solar Cells from Hydrocarbon Solvents

    KAUST Repository

    Wadsworth, Andrew; Ashraf, Raja; Abdelsamie, Maged; Pont, Sebastian; Little, Mark; Moser, Maximilian; Hamid, Zeinab; Neophytou, Marios; Zhang, Weimin; Amassian, Aram; Durrant, James R.; Baran, Derya; McCulloch, Iain

    2017-01-01

    With chlorinated solvents unlikely to be permitted for use in solution-processed organic solar cells in industry, there must be a focus on developing nonchlorinated solvent systems. Here we report high-efficiency devices utilizing a low-bandgap donor polymer (PffBT4T-2DT) and a nonfullerene acceptor (EH-IDTBR) from hydrocarbon solvents and without using additives. When mesitylene was used as the solvent, rather than chlorobenzene, an improved power conversion efficiency (11.1%) was achieved without the need for pre- or post-treatments. Despite altering the processing conditions to environmentally friendly solvents and room-temperature coating, grazing incident X-ray measurements confirmed that active layers processed from hydrocarbon solvents retained the robust nanomorphology obtained with hot-processed chlorinated solvents. The main advantages of hydrocarbon solvent-processed devices, besides the improved efficiencies, were the reproducibility and storage lifetime of devices. Mesitylene devices showed better reproducibility and shelf life up to 4000 h with PCE dropping by only 8% of its initial value.

  5. Everware toolkit. Supporting reproducible science and challenge-driven education.

    Science.gov (United States)

    Ustyuzhanin, A.; Head, T.; Babuschkin, I.; Tiunov, A.

    2017-10-01

    Modern science clearly demands for a higher level of reproducibility and collaboration. To make research fully reproducible one has to take care of several aspects: research protocol description, data access, environment preservation, workflow pipeline, and analysis script preservation. Version control systems like git help with the workflow and analysis scripts part. Virtualization techniques like Docker or Vagrant can help deal with environments. Jupyter notebooks are a powerful platform for conducting research in a collaborative manner. We present project Everware that seamlessly integrates git repository management systems such as Github or Gitlab, Docker and Jupyter helping with a) sharing results of real research and b) boosts education activities. With the help of Everware one can not only share the final artifacts of research but all the depth of the research process. This been shown to be extremely helpful during organization of several data analysis hackathons and machine learning schools. Using Everware participants could start from an existing solution instead of starting from scratch. They could start contributing immediately. Everware allows its users to make use of their own computational resources to run the workflows they are interested in, which leads to higher scalability of the toolkit.

  6. Fluctuation-Driven Neural Dynamics Reproduce Drosophila Locomotor Patterns.

    Directory of Open Access Journals (Sweden)

    Andrea Maesani

    2015-11-01

    Full Text Available The neural mechanisms determining the timing of even simple actions, such as when to walk or rest, are largely mysterious. One intriguing, but untested, hypothesis posits a role for ongoing activity fluctuations in neurons of central action selection circuits that drive animal behavior from moment to moment. To examine how fluctuating activity can contribute to action timing, we paired high-resolution measurements of freely walking Drosophila melanogaster with data-driven neural network modeling and dynamical systems analysis. We generated fluctuation-driven network models whose outputs-locomotor bouts-matched those measured from sensory-deprived Drosophila. From these models, we identified those that could also reproduce a second, unrelated dataset: the complex time-course of odor-evoked walking for genetically diverse Drosophila strains. Dynamical models that best reproduced both Drosophila basal and odor-evoked locomotor patterns exhibited specific characteristics. First, ongoing fluctuations were required. In a stochastic resonance-like manner, these fluctuations allowed neural activity to escape stable equilibria and to exceed a threshold for locomotion. Second, odor-induced shifts of equilibria in these models caused a depression in locomotor frequency following olfactory stimulation. Our models predict that activity fluctuations in action selection circuits cause behavioral output to more closely match sensory drive and may therefore enhance navigation in complex sensory environments. Together these data reveal how simple neural dynamics, when coupled with activity fluctuations, can give rise to complex patterns of animal behavior.

  7. Reproducibility of suppression of Pythium wilt of cucumber by compost

    Directory of Open Access Journals (Sweden)

    Mauritz Vilhelm Vestberg

    2014-10-01

    Full Text Available There is increasing global interest in using compost to suppress soil-borne fungal and bacterial diseases and nematodes. We studied the reproducibility of compost suppressive capacity (SC against Pythium wilt of cucumber using nine composts produced by the same composting plant in 2008 and 2009. A bioassay was set up in a greenhouse using cucumber inoculated with two strains of Pythium. The composts were used as 20% mixtures (v:v of a basic steam-sterilized light Sphagnum peat and sand (3:1, v:v. Shoot height was measured weekly during the 5-week experiment. At harvest, the SC was calculated as the % difference in shoot dry weight (DW between non-inoculated and inoculated cucumbers. The SC was not affected by year of production (2008 or 2009, indicating reproducibility of SC when the raw materials and the composting method are not changed. Differences in shoot height were not as pronounced as those for shoot DW. The results were encouraging, but further studies are still needed for producing compost with guaranteed suppressiveness properties.

  8. Reproducibility of tomographic evaluation of posterolateral lumbar arthrodesis consolidation

    Directory of Open Access Journals (Sweden)

    Marcelo Italo Risso Neto

    2015-06-01

    Full Text Available OBJECTIVE: To evaluate interobserver agreement of Glassman classification for posterolateral lumbar spine arthrodesis.METHODS: One hundred and thirty-four CT scans from patients who underwent posterolateral arthrodesis of the lumbar and lumbosacral spine were evaluated by four observers, namely two orthopedic surgeons experienced in spine surgery and two in training in this area. Using the reconstructed tomographic images at oblique coronal plane, 299 operated levels were systematically analyzed looking for arthrodesis signals. The appearance of bone healing in each operated level was classified in five categories as proposed by Glassman to the posterolateral arthrodesis: 1 bilateral solid arthrodesis; 2 unilateral solid arthrodesis; 3 bilateral partial arthrodesis; 4 unilateral partial arthrodesis; 5 absence of arthrodesis. In a second step, the evaluation of each operated level was divided into two categories: fusion (including type 1, 2, 3, and 4 and non fusion (type 5. Statistical analysis was performed by calculating the Kappa coefficient considering the paired analysis between the two experienced observers and between the two observers in training.RESULTS: The interobserver reproducibility by the kappa coefficient for arthrodesis consolidation analysis for the classification proposed, divided into 5 types, was 0.729 for both experienced surgeons and training surgeons. Considering only two categories kappa coefficient was 0.745 between experienced surgeons and 0.795 between training surgeons. In all analyzes, we obtained high concordance power.CONCLUSION: Interobserver reproducibility was observed with high concordance in the classification proposed by Glassman for posterolateral arthrodesis of the lumbar and lumbosacral spine.

  9. Reproducibility of P-31 spectroscopic imaging of normal human myocardium

    International Nuclear Information System (INIS)

    Tavares, N.J.; Chew, W.; Auffermann, W.; Higgins, C.B.

    1988-01-01

    To assess reproducibility of P-31 MR spectroscopy of human myocardium, ten normal male volunteers were studied on two separate occasions. Spectra were acquired on a clinical 1.5-T MR imaging unit (Signa, General Electric) using a one-dimensional gated spectroscopic imaging sequence (matrix size, 32 X 256) over 20 minutes. Peaks in the adenosine triphosphate (ATP) region, phosphocreatine (PCR), phosphodiesters (PD), and peaks attributable to 2,3 diphosphoglycerate from blood were observed. Interindividual and intraindividual variability expressed as standard errors of the mean (mean +- SEM) were 1.54 +- 0.04 (variability among subjects) and 0.04 (variability between first and second studies) for PCR/β ATP; 0.97 +- 0.18 and 0.06 for PD/β ATP; and 0.62 +- 0.10 and 0.05 for PD/PCR, respectively. In conclusion, P-31 MR spectroscopy yields consistent and reproducible myocardial spectra that might be useful in the future for the evaluation and monitoring of cardiac disease

  10. Highly Efficient and Reproducible Nonfullerene Solar Cells from Hydrocarbon Solvents

    KAUST Repository

    Wadsworth, Andrew

    2017-06-01

    With chlorinated solvents unlikely to be permitted for use in solution-processed organic solar cells in industry, there must be a focus on developing nonchlorinated solvent systems. Here we report high-efficiency devices utilizing a low-bandgap donor polymer (PffBT4T-2DT) and a nonfullerene acceptor (EH-IDTBR) from hydrocarbon solvents and without using additives. When mesitylene was used as the solvent, rather than chlorobenzene, an improved power conversion efficiency (11.1%) was achieved without the need for pre- or post-treatments. Despite altering the processing conditions to environmentally friendly solvents and room-temperature coating, grazing incident X-ray measurements confirmed that active layers processed from hydrocarbon solvents retained the robust nanomorphology obtained with hot-processed chlorinated solvents. The main advantages of hydrocarbon solvent-processed devices, besides the improved efficiencies, were the reproducibility and storage lifetime of devices. Mesitylene devices showed better reproducibility and shelf life up to 4000 h with PCE dropping by only 8% of its initial value.

  11. A Bayesian Perspective on the Reproducibility Project: Psychology.

    Science.gov (United States)

    Etz, Alexander; Vandekerckhove, Joachim

    2016-01-01

    We revisit the results of the recent Reproducibility Project: Psychology by the Open Science Collaboration. We compute Bayes factors-a quantity that can be used to express comparative evidence for an hypothesis but also for the null hypothesis-for a large subset (N = 72) of the original papers and their corresponding replication attempts. In our computation, we take into account the likely scenario that publication bias had distorted the originally published results. Overall, 75% of studies gave qualitatively similar results in terms of the amount of evidence provided. However, the evidence was often weak (i.e., Bayes factor studies (64%) did not provide strong evidence for either the null or the alternative hypothesis in either the original or the replication, and no replication attempts provided strong evidence in favor of the null. In all cases where the original paper provided strong evidence but the replication did not (15%), the sample size in the replication was smaller than the original. Where the replication provided strong evidence but the original did not (10%), the replication sample size was larger. We conclude that the apparent failure of the Reproducibility Project to replicate many target effects can be adequately explained by overestimation of effect sizes (or overestimation of evidence against the null hypothesis) due to small sample sizes and publication bias in the psychological literature. We further conclude that traditional sample sizes are insufficient and that a more widespread adoption of Bayesian methods is desirable.

  12. Automation of cDNA Synthesis and Labelling Improves Reproducibility

    Directory of Open Access Journals (Sweden)

    Daniel Klevebring

    2009-01-01

    Full Text Available Background. Several technologies, such as in-depth sequencing and microarrays, enable large-scale interrogation of genomes and transcriptomes. In this study, we asses reproducibility and throughput by moving all laboratory procedures to a robotic workstation, capable of handling superparamagnetic beads. Here, we describe a fully automated procedure for cDNA synthesis and labelling for microarrays, where the purification steps prior to and after labelling are based on precipitation of DNA on carboxylic acid-coated paramagnetic beads. Results. The fully automated procedure allows for samples arrayed on a microtiter plate to be processed in parallel without manual intervention and ensuring high reproducibility. We compare our results to a manual sample preparation procedure and, in addition, use a comprehensive reference dataset to show that the protocol described performs better than similar manual procedures. Conclusions. We demonstrate, in an automated gene expression microarray experiment, a reduced variance between replicates, resulting in an increase in the statistical power to detect differentially expressed genes, thus allowing smaller differences between samples to be identified. This protocol can with minor modifications be used to create cDNA libraries for other applications such as in-depth analysis using next-generation sequencing technologies.

  13. Reproducibility of temporomandibular joint tomography. Influence of shifted X-ray beam and tomographic focal plane on reproducibility

    International Nuclear Information System (INIS)

    Saito, Masashi

    1999-01-01

    Proper tomographic focal plane and x-ray beam direction are the most important factors to obtain accurate images of the temporomandibular joint (TMJ). In this study, to clarify the magnitude of effect of these two factors on the image quality. We evaluated the reproducibility of tomograms by measuring the distortion when the x-ray beam was shifted from the correct center of the object. The effects of the deviation of the tomographic focal plane on image quality were evaluated by the MTF (Modulation Transfer Function). Two types of tomograms, one the plane type, the other the rotational type were used in this study. A TMJ model was made from Teflon for the purpose of evaluation by shifting the x-ray beam. The x-ray images were obtained by tilting the model from 0 to 10 degrees 2-degree increments. These x-ray images were processed for computer image analysis, and then the distance between condyle and the joint space was measured. To evaluate the influence of the shifted tomographic focal plane on image sharpness, the x-ray images from each setting were analyzed by MTF. To obtain the MTF, ''knife-edge'' made from Pb was used. The images were scanned with a microdensitometer at the central focal plane, and 0, 0.5, 1 mm away respectively. The density curves were analyzed by Fourier analysis and the MTF was calculated. The reproducibility of images became worse by shifting the x-ray beam. This tendency was similar for both tomograms. Object characteristics such as anterior and posterior portion of the joint space affected the deterioration of reproducibility of the tomography. The deviation of the tomographic focal plane also decreased the reproducibility of the x-ray images. The rotational type showed a better MTF, but it became seriously unfavorable with slight changes of the tomographic focal plane. Contrarily, the plane type showed a lower MTF, but the image was stable with shifting of the tomographic focal plane. (author)

  14. Reliability of procedures used for scaling loudness

    DEFF Research Database (Denmark)

    Jesteadt, Walt; Joshi, Suyash Narendra

    2013-01-01

    In this study, 16 normally-hearing listeners judged the loudness of 1000-Hz sinusoids using magnitude estimation (ME), magnitude production (MP), and categorical loudness scaling (CLS). Listeners in each of four groups completed the loudness scaling tasks in a different sequence on the first visit...... (ME, MP, CLS; MP, ME, CLS; CLS, ME, MP; CLS, MP, ME), and the order was reversed on the second visit. This design made it possible to compare the reliability of estimates of the slope of the loudness function across procedures in the same listeners. The ME data were well fitted by an inflected...... results were the most reproducible, they do not provide direct information about the slope of the loudness function because the numbers assigned to CLS categories are arbitrary. This problem can be corrected by using data from the other procedures to assign numbers that are proportional to loudness...

  15. Reliability of quantitative echocardiography in adult sheep and goats

    Directory of Open Access Journals (Sweden)

    Hallowell Gayle D

    2012-09-01

    Full Text Available Abstract Background Echocardiography is a non-invasive method for assessment of the ovine and caprine heart. Complete reference ranges for cardiac dimensions and time indices for both species are not currently available and reliability of these measurements has not been evaluated. The objectives for this study are to report reliability, normal cardiac dimensions and time indices in a large group of adult sheep and goats. Fifty-one adult sheep and forty adult goats were recruited. Full echocardiographic examinations were performed in the standing unsedated animal. All animals underwent echocardiography four times in a 72-hour period. Echocardiography was performed three times by one author and once by another. Images were stored and measured offline. Technique and measurement repeatability and reproducibility and any differences due to animal or day were evaluated. Reference ranges (mean ± 2 standard deviations were calculated for both species. Results Majority of the images obtained were of good to excellent quality. Image acquisition was straightforward with 5.4% of animals demonstrating a small scanning window. Reliability was excellent for majority of dimensions and time indices. There was less variation in repeatability when compared with reproducibility and differences were greater for technique than for measurements. Dimensions that were less reliable included those for right ventricular diameter and left ventricular free wall. There were many differences in cardiac dimensions between sheep and goats. Conclusions This study has demonstrated that specific reference ranges are required for these two species. Repeatability and reproducibility were excellent for the majority of cardiac dimensions and time indices suggesting that this technique is reliable and valuable for examination of clinical cases over time and for longitudinal research studies.

  16. Nuclear performance and reliability

    International Nuclear Information System (INIS)

    Rothwell, G.

    1993-01-01

    If fewer forced outages are a sign of improved safety, nuclear power plants have become safer and more productive. There has been a significant improvement in nuclear power plant performance, due largely to a decline in the forced outage rate and a dramatic drop in the average number of forced outages per fuel cycle. If fewer forced outages are a sign of improved safety, nuclear power plants have become safer and more productive over time. To encourage further increases in performance, regulatory incentive schemes should reward reactor operators for improved reliability and safety, as well as for improved performance

  17. [How Reliable is Neuronavigation?].

    Science.gov (United States)

    Stieglitz, Lennart Henning

    2016-02-17

    Neuronavigation plays a central role in modern neurosurgery. It allows visualizing instruments and three-dimensional image data intraoperatively and supports spatial orientation. Thus it allows to reduce surgical risks and speed up complex surgical procedures. The growing availability and importance of neuronavigation makes clear how relevant it is to know about its reliability and accuracy. Different factors may influence the accuracy during the surgery unnoticed, misleading the surgeon. Besides the best possible optimization of the systems themselves, a good knowledge about its weaknesses is mandatory for every neurosurgeon.

  18. The value of reliability

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Karlström, Anders

    2010-01-01

    We derive the value of reliability in the scheduling of an activity of random duration, such as travel under congested conditions. Using a simple formulation of scheduling utility, we show that the maximal expected utility is linear in the mean and standard deviation of trip duration, regardless...... of the form of the standardised distribution of trip durations. This insight provides a unification of the scheduling model and models that include the standard deviation of trip duration directly as an argument in the cost or utility function. The results generalise approximately to the case where the mean...

  19. Paleomagnetic analysis of curved thrust belts reproduced by physical models

    Science.gov (United States)

    Costa, Elisabetta; Speranza, Fabio

    2003-12-01

    This paper presents a new methodology for studying the evolution of curved mountain belts by means of paleomagnetic analyses performed on analogue models. Eleven models were designed aimed at reproducing various tectonic settings in thin-skinned tectonics. Our models analyze in particular those features reported in the literature as possible causes for peculiar rotational patterns in the outermost as well as in the more internal fronts. In all the models the sedimentary cover was reproduced by frictional low-cohesion materials (sand and glass micro-beads), which detached either on frictional or on viscous layers. These latter were reproduced in the models by silicone. The sand forming the models has been previously mixed with magnetite-dominated powder. Before deformation, the models were magnetized by means of two permanent magnets generating within each model a quasi-linear magnetic field of intensity variable between 20 and 100 mT. After deformation, the models were cut into closely spaced vertical sections and sampled by means of 1×1-cm Plexiglas cylinders at several locations along curved fronts. Care was taken to collect paleomagnetic samples only within virtually undeformed thrust sheets, avoiding zones affected by pervasive shear. Afterwards, the natural remanent magnetization of these samples was measured, and alternating field demagnetization was used to isolate the principal components. The characteristic components of magnetization isolated were used to estimate the vertical-axis rotations occurring during model deformation. We find that indenters pushing into deforming belts from behind form non-rotational curved outer fronts. The more internal fronts show oroclinal-type rotations of a smaller magnitude than that expected for a perfect orocline. Lateral symmetrical obstacles in the foreland colliding with forward propagating belts produce non-rotational outer curved fronts as well, whereas in between and inside the obstacles a perfect orocline forms

  20. Translation, cultural adaptation and reproducibility of the Cochin Hand Functional Scale questionnaire for Brazil

    Directory of Open Access Journals (Sweden)

    Aline Chiari

    2011-01-01

    Full Text Available OBJECTIVE: To translate, to perform a cultural adaptation of and to test the reproducibility of the Cochin Hand Functional Scale questionnaire for Brazil. METHODS: First, the Cochin Hand Functional Scale questionnaire was translated into Portuguese and was then back-translated into French. These translations were reviewed by a committee to establish a Brazilian version of the questionnaire to be tested. The validity and reproducibility of the Cochin Hand Functional Scale questionnaire was evaluated. Patients of both sexes, who were aged 18 to 60 years and presented with rheumatoid arthritis affecting their hands, were interviewed. The patients were initially interviewed by two observers and were later interviewed by a single rater. First, the Visual Analogue Scale for hand pain, the Arm, Shoulder and Hand Disability questionnaire and the Health Assessment Questionnaire were administered. The third administration of the Cochin Hand Functional Scale was performed fifteen days after the first administration. Ninety patients were assessed in the present study. RESULTS: Two questions were modified as a result of the assessment of cultural equivalence. The Cronbach's alpha value for this assessment was 0.93. The intraclass intraobserver and interobserver correlation coefficients were 0.76 and 0.96, respectively. The Spearman's coefficient indicated that there was a low level of correlation between the Cochin Hand Functional Scale and the Visual Analogue Scale for pain (0.46 and that there was a moderate level of correlation of the Cochin Scale with the Health Assessment Questionnaire (0.66 and with the Disability of the Arm, Shoulder and Hand questionnaire (0.63. The average administration time for the Cochin Scale was three minutes. CONCLUSION: The Brazilian version of the Cochin Hand Functional Scale was successfully translated and adapted, and this version exhibited good internal consistency, reliability and construct validity.

  1. A nondestructive, reproducible method of measuring joint reaction force at the distal radioulnar joint.

    Science.gov (United States)

    Canham, Colin D; Schreck, Michael J; Maqsoodi, Noorullah; Doolittle, Madison; Olles, Mark; Elfar, John C

    2015-06-01

    To develop a nondestructive method of measuring distal radioulnar joint (DRUJ) joint reaction force (JRF) that preserves all periarticular soft tissues and more accurately reflects in vivo conditions. Eight fresh-frozen human cadaveric limbs were obtained. A threaded Steinmann pin was placed in the middle of the lateral side of the distal radius transverse to the DRUJ. A second pin was placed into the middle of the medial side of the distal ulna colinear to the distal radial pin. Specimens were mounted onto a tensile testing machine using a custom fixture. A uniaxial distracting force was applied across the DRUJ while force and displacement were simultaneously measured. Force-displacement curves were generated and a best-fit polynomial was solved to determine JRF. All force-displacement curves demonstrated an initial high slope where relatively large forces were required to distract the joint. This ended with an inflection point followed by a linear area with a low slope, where small increases in force generated larger amounts of distraction. Each sample was measured 3 times and there was high reproducibility between repeated measurements. The average baseline DRUJ JRF was 7.5 N (n = 8). This study describes a reproducible method of measuring DRUJ reaction forces that preserves all periarticular stabilizing structures. This technique of JRF measurement may also be suited for applications in the small joints of the wrist and hand. Changes in JRF can alter native joint mechanics and lead to pathology. Reliable methods of measuring these forces are important for determining how pathology and surgical interventions affect joint biomechanics. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  2. Non-coding RNA detection methods combined to improve usability, reproducibility and precision

    Directory of Open Access Journals (Sweden)

    Kreikemeyer Bernd

    2010-09-01

    Full Text Available Abstract Background Non-coding RNAs gain more attention as their diverse roles in many cellular processes are discovered. At the same time, the need for efficient computational prediction of ncRNAs increases with the pace of sequencing technology. Existing tools are based on various approaches and techniques, but none of them provides a reliable ncRNA detector yet. Consequently, a natural approach is to combine existing tools. Due to a lack of standard input and output formats combination and comparison of existing tools is difficult. Also, for genomic scans they often need to be incorporated in detection workflows using custom scripts, which decreases transparency and reproducibility. Results We developed a Java-based framework to integrate existing tools and methods for ncRNA detection. This framework enables users to construct transparent detection workflows and to combine and compare different methods efficiently. We demonstrate the effectiveness of combining detection methods in case studies with the small genomes of Escherichia coli, Listeria monocytogenes and Streptococcus pyogenes. With the combined method, we gained 10% to 20% precision for sensitivities from 30% to 80%. Further, we investigated Streptococcus pyogenes for novel ncRNAs. Using multiple methods--integrated by our framework--we determined four highly probable candidates. We verified all four candidates experimentally using RT-PCR. Conclusions We have created an extensible framework for practical, transparent and reproducible combination and comparison of ncRNA detection methods. We have proven the effectiveness of this approach in tests and by guiding experiments to find new ncRNAs. The software is freely available under the GNU General Public License (GPL, version 3 at http://www.sbi.uni-rostock.de/moses along with source code, screen shots, examples and tutorial material.

  3. Reproducibility and signal response linearity of Alanine gel dosimeter

    International Nuclear Information System (INIS)

    Silva, Cleber Feijo Silva; Campos, Leticia Lucente

    2008-01-01

    Gel Dosimetry has been studied mainly for medical applications, because it presents signal response in the dose range used in radiotherapy treatments and it can be applied for three dimensional dosimetry. Alanine gel dosimeter is a new gel material developed at IPEN that presents significant improvement on previous alanine systems developed by Costa (1994). The DL-Alanine (C 3 H 7 NO 2 ) is an amino acid tissue equivalent that improves the production of ferric ions in the solution. These ferric ions concentration can be measured by spectrophotometry technique. This work aims to study the reproducibility of the alanine gel solutions and the signal response as a function of gamma radiation dose, considering that these two properties are very important for characterizing and standardizing any dosimeter. (author)

  4. Novel burn device for rapid, reproducible burn wound generation.

    Science.gov (United States)

    Kim, J Y; Dunham, D M; Supp, D M; Sen, C K; Powell, H M

    2016-03-01

    Scarring following full thickness burns leads to significant reductions in range of motion and quality of life for burn patients. To effectively study scar development and the efficacy of anti-scarring treatments in a large animal model (female red Duroc pigs), reproducible, uniform, full-thickness, burn wounds are needed to reduce variability in observed results that occur with burn depth. Prior studies have proposed that initial temperature of the burner, contact time with skin, thermal capacity of burner material, and the amount of pressure applied to the skin need to be strictly controlled to ensure reproducibility. The purpose of this study was to develop a new burner that enables temperature and pressure to be digitally controlled and monitored in real-time throughout burn wound creation and compare it to a standard burn device. A custom burn device was manufactured with an electrically heated burn stylus and a temperature control feedback loop via an electronic microstat. Pressure monitoring was controlled by incorporation of a digital scale into the device, which measured downward force. The standard device was comprised of a heat resistant handle with a long rod connected to the burn stylus, which was heated using a hot plate. To quantify skin surface temperature and internal stylus temperature as a function of contact time, the burners were heated to the target temperature (200±5°C) and pressed into the skin for 40s to create the thermal injuries. Time to reach target temperature and elapsed time between burns were recorded. In addition, each unit was evaluated for reproducibility within and across three independent users by generating burn wounds at contact times spanning from 5 to 40s at a constant pressure and at pressures of 1 or 3lbs with a constant contact time of 40s. Biopsies were collected for histological analysis and burn depth quantification using digital image analysis (ImageJ). The custom burn device maintained both its internal

  5. Measurement System Analyses - Gauge Repeatability and Reproducibility Methods

    Science.gov (United States)

    Cepova, Lenka; Kovacikova, Andrea; Cep, Robert; Klaput, Pavel; Mizera, Ondrej

    2018-02-01

    The submitted article focuses on a detailed explanation of the average and range method (Automotive Industry Action Group, Measurement System Analysis approach) and of the honest Gauge Repeatability and Reproducibility method (Evaluating the Measurement Process approach). The measured data (thickness of plastic parts) were evaluated by both methods and their results were compared on the basis of numerical evaluation. Both methods were additionally compared and their advantages and disadvantages were discussed. One difference between both methods is the calculation of variation components. The AIAG method calculates the variation components based on standard deviation (then a sum of variation components does not give 100 %) and the honest GRR study calculates the variation components based on variance, where the sum of all variation components (part to part variation, EV & AV) gives the total variation of 100 %. Acceptance of both methods among the professional society, future use, and acceptance by manufacturing industry were also discussed. Nowadays, the AIAG is the leading method in the industry.

  6. The Web system of visualization and analysis equipped with reproducibility

    International Nuclear Information System (INIS)

    Ueshima, Yutaka; Saito, Kanji; Takeda, Yasuhiro; Nakai, Youichi; Hayashi, Sachiko

    2005-01-01

    In the advanced photon experimental research, real-time visualization and steering system is thought as desirable method of data analysis. This approach is valid only in the fixed analysis at one time or in the easily reproducible experiment. But, in the research for an unknown problem like the advanced photon experimental research, it is necessary that the observation data can be analyzed many times because profitable analysis is difficult at the first time. Consequently, output data should be filed to refer and analyze at any time. To support the research, we need the followed automatic functions, transporting data files from data generator to data storage, analyzing data, tracking history of data handling, and so on. The supporting system will be integrated database system with several functional servers distributed on the network. (author)

  7. Reproducibility with the Keeler Pulsair 2000 non-contact tonometer.

    Science.gov (United States)

    Vernon, S A

    1995-06-01

    The IOP variation on repeated testing with the recently introduced Keeler Pulsair 2000 instrument was investigated. One hundred normal individuals (50 male and 50 female) new to the instrument had three sets of IOP recordings within a 15 minute time period. The mean of the first set of IOPs from both right and left eyes was significantly higher than those from subsequent sets (p < 0.0001 for right eyes and p = 0.01 and < 0.0002 for left eyes). This tendency increased significantly with increasing IOP. Second and third IOP sets were, however, similar indicating stabilisation of IOP measurements. The coefficient of repeatability of the instrument between second and third sets was 4.2 mm Hg for right eyes and 3.6 mm Hg for left eyes. The Pulsair 2000 passes the British standard for reproducibility of a standard test method.

  8. Quark/gluon jet discrimination: a reproducible analysis using R

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    The power to discriminate between light-quark jets and gluon jets would have a huge impact on many searches for new physics at CERN and beyond. This talk will present a walk-through of the development of a prototype machine learning classifier for differentiating between quark and gluon jets at experiments like those at the Large Hadron Collider at CERN. A new fast feature selection method that combines information theory and graph analytics will be outlined. This method has found new variables that promise significant improvements in discrimination power. The prototype jet tagger is simple, interpretable, parsimonious, and computationally extremely cheap, and therefore might be suitable for use in trigger systems for real-time data processing. Nested stratified k-fold cross validation was used to generate robust estimates of model performance. The data analysis was performed entirely in the R statistical programming language, and is fully reproducible. The entire analysis workflow is data-driven, automated a...

  9. Towards Reproducible Research Data Analyses in LHC Particle Physics

    CERN Document Server

    Simko, Tibor

    2017-01-01

    The reproducibility of the research data analysis requires having access not only to the original datasets, but also to the computing environment, the analysis software and the workflow used to produce the original results. We present the nascent CERN Analysis Preservation platform with a set of tools developed to support particle physics researchers in preserving the knowledge around analyses so that capturing, sharing, reusing and reinterpreting data becomes easier. The presentation will focus on three pillars: (i) capturing structured knowledge information about data analysis processes; (ii) capturing the computing environment, the software code, the datasets, the configuration and other information assets used in data analyses; (iii) re-instantiating of preserved analyses on a containerised computing cloud for the purposes of re-validation and re-interpretation.

  10. Timbral aspects of reproduced sound in small rooms. II

    DEFF Research Database (Denmark)

    Bech, Søren

    1996-01-01

    A single loudspeaker with frequency-dependent directivity characteristics, positioned in a room of normal size with frequency-dependent absorption coefficients of the room surfaces, has been simulated using an electroacoustic setup. The model included the direct sound, seventeen individual...... reflections and the reverberant field. The threshold of detection, and just-noticeable differences for an increase in level were measured for individual reflections. The results have confirmed that the first-order floor reflection is likely to contribute individually to the timbre of reproduced noise. However......, for a speech signal none of the investigated reflections will contribute individually to the timbre. It is suggested that the threshold of detection is determined by the spectral changes in the dominant frequency range of 500 Hz to 2 kHz. For increases in the level of individual reflections, the most likely...

  11. Robust tissue classification for reproducible wound assessment in telemedicine environments

    Science.gov (United States)

    Wannous, Hazem; Treuillet, Sylvie; Lucas, Yves

    2010-04-01

    In telemedicine environments, a standardized and reproducible assessment of wounds, using a simple free-handled digital camera, is an essential requirement. However, to ensure robust tissue classification, particular attention must be paid to the complete design of the color processing chain. We introduce the key steps including color correction, merging of expert labeling, and segmentation-driven classification based on support vector machines. The tool thus developed ensures stability under lighting condition, viewpoint, and camera changes, to achieve accurate and robust classification of skin tissues. Clinical tests demonstrate that such an advanced tool, which forms part of a complete 3-D and color wound assessment system, significantly improves the monitoring of the healing process. It achieves an overlap score of 79.3 against 69.1% for a single expert, after mapping on the medical reference developed from the image labeling by a college of experts.

  12. Efficient and reproducible identification of mismatch repair deficient colon cancer

    DEFF Research Database (Denmark)

    Joost, Patrick; Bendahl, Pär-Ola; Halvarsson, Britta

    2013-01-01

    BACKGROUND: The identification of mismatch-repair (MMR) defective colon cancer is clinically relevant for diagnostic, prognostic and potentially also for treatment predictive purposes. Preselection of tumors for MMR analysis can be obtained with predictive models, which need to demonstrate ease...... of application and favorable reproducibility. METHODS: We validated the MMR index for the identification of prognostically favorable MMR deficient colon cancers and compared performance to 5 other prediction models. In total, 474 colon cancers diagnosed ≥ age 50 were evaluated with correlation between...... clinicopathologic variables and immunohistochemical MMR protein expression. RESULTS: Female sex, age ≥60 years, proximal tumor location, expanding growth pattern, lack of dirty necrosis, mucinous differentiation and presence of tumor-infiltrating lymphocytes significantly correlated with MMR deficiency. Presence...

  13. Interactive reliability assessment using an integrated reliability data bank

    International Nuclear Information System (INIS)

    Allan, R.N.; Whitehead, A.M.

    1986-01-01

    The logical structure, techniques and practical application of a computer-aided technique based on a microcomputer using floppy disc Random Access Files is described. This interactive computational technique is efficient if the reliability prediction program is coupled directly to a relevant source of data to create an integrated reliability assessment/reliability data bank system. (DG)

  14. Load Control System Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Trudnowski, Daniel [Montana Tech of the Univ. of Montana, Butte, MT (United States)

    2015-04-03

    This report summarizes the results of the Load Control System Reliability project (DOE Award DE-FC26-06NT42750). The original grant was awarded to Montana Tech April 2006. Follow-on DOE awards and expansions to the project scope occurred August 2007, January 2009, April 2011, and April 2013. In addition to the DOE monies, the project also consisted of matching funds from the states of Montana and Wyoming. Project participants included Montana Tech; the University of Wyoming; Montana State University; NorthWestern Energy, Inc., and MSE. Research focused on two areas: real-time power-system load control methodologies; and, power-system measurement-based stability-assessment operation and control tools. The majority of effort was focused on area 2. Results from the research includes: development of fundamental power-system dynamic concepts, control schemes, and signal-processing algorithms; many papers (including two prize papers) in leading journals and conferences and leadership of IEEE activities; one patent; participation in major actual-system testing in the western North American power system; prototype power-system operation and control software installed and tested at three major North American control centers; and, the incubation of a new commercial-grade operation and control software tool. Work under this grant certainly supported the DOE-OE goals in the area of “Real Time Grid Reliability Management.”

  15. Microprocessor hardware reliability

    Energy Technology Data Exchange (ETDEWEB)

    Wright, R I

    1982-01-01

    Microprocessor-based technology has had an impact in nearly every area of industrial electronics and many applications have important safety implications. Microprocessors are being used for the monitoring and control of hazardous processes in the chemical, oil and power generation industries, for the control and instrumentation of aircraft and other transport systems and for the control of industrial machinery. Even in the field of nuclear reactor protection, where designers are particularly conservative, microprocessors are used to implement certain safety functions and may play increasingly important roles in protection systems in the future. Where microprocessors are simply replacing conventional hard-wired control and instrumentation systems no new hazards are created by their use. In the field of robotics, however, the microprocessor has opened up a totally new technology and with it has created possible new and as yet unknown hazards. The paper discusses some of the design and manufacturing techniques which may be used to enhance the reliability of microprocessor based systems and examines the available reliability data on lsi/vlsi microcircuits. 12 references.

  16. Supply chain reliability modelling

    Directory of Open Access Journals (Sweden)

    Eugen Zaitsev

    2012-03-01

    Full Text Available Background: Today it is virtually impossible to operate alone on the international level in the logistics business. This promotes the establishment and development of new integrated business entities - logistic operators. However, such cooperation within a supply chain creates also many problems related to the supply chain reliability as well as the optimization of the supplies planning. The aim of this paper was to develop and formulate the mathematical model and algorithms to find the optimum plan of supplies by using economic criterion and the model for the probability evaluating of non-failure operation of supply chain. Methods: The mathematical model and algorithms to find the optimum plan of supplies were developed and formulated by using economic criterion and the model for the probability evaluating of non-failure operation of supply chain. Results and conclusions: The problem of ensuring failure-free performance of goods supply channel analyzed in the paper is characteristic of distributed network systems that make active use of business process outsourcing technologies. The complex planning problem occurring in such systems that requires taking into account the consumer's requirements for failure-free performance in terms of supply volumes and correctness can be reduced to a relatively simple linear programming problem through logical analysis of the structures. The sequence of the operations, which should be taken into account during the process of the supply planning with the supplier's functional reliability, was presented.

  17. Numerical optimization of alignment reproducibility for customizable surgical guides.

    Science.gov (United States)

    Kroes, Thomas; Valstar, Edward; Eisemann, Elmar

    2015-10-01

    Computer-assisted orthopedic surgery aims at minimizing invasiveness, postoperative pain, and morbidity with computer-assisted preoperative planning and intra-operative guidance techniques, of which camera-based navigation and patient-specific templates (PST) are the most common. PSTs are one-time templates that guide the surgeon initially in cutting slits or drilling holes. This method can be extended to reusable and customizable surgical guides (CSG), which can be adapted to the patients' bone. Determining the right set of CSG input parameters by hand is a challenging task, given the vast amount of input parameter combinations and the complex physical interaction between the PST/CSG and the bone. This paper introduces a novel algorithm to solve the problem of choosing the right set of input parameters. Our approach predicts how well a CSG instance is able to reproduce the planned alignment based on a physical simulation and uses a genetic optimization algorithm to determine optimal configurations. We validate our technique with a prototype of a pin-based CSG and nine rapid prototyped distal femora. The proposed optimization technique has been compared to manual optimization by experts, as well as participants with domain experience. Using the optimization technique, the alignment errors remained within practical boundaries of 1.2 mm translation and [Formula: see text] rotation error. In all cases, the proposed method outperformed manual optimization. Manually optimizing CSG parameters turns out to be a counterintuitive task. Even after training, subjects with and without anatomical background fail in choosing appropriate CSG configurations. Our optimization algorithm ensures that the CSG is configured correctly, and we could demonstrate that the intended alignment of the CSG is accurately reproduced on all tested bone geometries.

  18. Illusory Motion Reproduced by Deep Neural Networks Trained for Prediction.

    Science.gov (United States)

    Watanabe, Eiji; Kitaoka, Akiyoshi; Sakamoto, Kiwako; Yasugi, Masaki; Tanaka, Kenta

    2018-01-01

    The cerebral cortex predicts visual motion to adapt human behavior to surrounding objects moving in real time. Although the underlying mechanisms are still unknown, predictive coding is one of the leading theories. Predictive coding assumes that the brain's internal models (which are acquired through learning) predict the visual world at all times and that errors between the prediction and the actual sensory input further refine the internal models. In the past year, deep neural networks based on predictive coding were reported for a video prediction machine called PredNet. If the theory substantially reproduces the visual information processing of the cerebral cortex, then PredNet can be expected to represent the human visual perception of motion. In this study, PredNet was trained with natural scene videos of the self-motion of the viewer, and the motion prediction ability of the obtained computer model was verified using unlearned videos. We found that the computer model accurately predicted the magnitude and direction of motion of a rotating propeller in unlearned videos. Surprisingly, it also represented the rotational motion for illusion images that were not moving physically, much like human visual perception. While the trained network accurately reproduced the direction of illusory rotation, it did not detect motion components in negative control pictures wherein people do not perceive illusory motion. This research supports the exciting idea that the mechanism assumed by the predictive coding theory is one of basis of motion illusion generation. Using sensory illusions as indicators of human perception, deep neural networks are expected to contribute significantly to the development of brain research.

  19. Reproducibility in Psychological Science: When Do Psychological Phenomena Exist?

    Directory of Open Access Journals (Sweden)

    Seppo E. Iso-Ahola

    2017-06-01

    Full Text Available Scientific evidence has recently been used to assert that certain psychological phenomena do not exist. Such claims, however, cannot be made because (1 scientific method itself is seriously limited (i.e., it can never prove a negative; (2 non-existence of phenomena would require a complete absence of both logical (theoretical and empirical support; even if empirical support is weak, logical and theoretical support can be strong; (3 statistical data are only one piece of evidence and cannot be used to reduce psychological phenomena to statistical phenomena; and (4 psychological phenomena vary across time, situations and persons. The human mind is unreproducible from one situation to another. Psychological phenomena are not particles that can decisively be tested and discovered. Therefore, a declaration that a phenomenon is not real is not only theoretically and empirically unjustified but runs counter to the propositional and provisional nature of scientific knowledge. There are only “temporary winners” and no “final truths” in scientific knowledge. Psychology is a science of subtleties in human affect, cognition and behavior. Its phenomena fluctuate with conditions and may sometimes be difficult to detect and reproduce empirically. When strictly applied, reproducibility is an overstated and even questionable concept in psychological science. Furthermore, statistical measures (e.g., effect size are poor indicators of the theoretical importance and relevance of phenomena (cf. “deliberate practice” vs. “talent” in expert performance, not to mention whether phenomena are real or unreal. To better understand psychological phenomena, their theoretical and empirical properties should be examined via multiple parameters and criteria. Ten such parameters are suggested.

  20. Repeatability and reproducibility of ribotyping and its computer interpretation.

    Science.gov (United States)

    Lefresne, Gwénola; Latrille, Eric; Irlinger, Françoise; Grimont, Patrick A D

    2004-04-01

    Many molecular typing methods are difficult to interpret because their repeatability (within-laboratory variance) and reproducibility (between-laboratory variance) have not been thoroughly studied. In the present work, ribotyping of coryneform bacteria was the basis of a study involving within-gel and between-gel repeatability and between-laboratory reproducibility (two laboratories involved). The effect of different technical protocols, different algorithms, and different software for fragment size determination was studied. Analysis of variance (ANOVA) showed, within a laboratory, that there was no significant added variance between gels. However, between-laboratory variance was significantly higher than within-laboratory variance. This may be due to the use of different protocols. An experimental function was calculated to transform the data and make them compatible (i.e., erase the between-laboratory variance). The use of different interpolation algorithms (spline, Schaffer and Sederoff) was a significant source of variation in one laboratory only. The use of either Taxotron (Institut Pasteur) or GelCompar (Applied Maths) was not a significant source of added variation when the same algorithm (spline) was used. However, the use of Bio-Gene (Vilber Lourmat) dramatically increased the error (within laboratory, within gel) in one laboratory, while decreasing the error in the other laboratory; this might be due to automatic normalization attempts. These results were taken into account for building a database and performing automatic pattern identification using Taxotron. Conversion of the data considerably improved the identification of patterns irrespective of the laboratory in which the data were obtained.

  1. Reproducibility in Psychological Science: When Do Psychological Phenomena Exist?

    Science.gov (United States)

    Iso-Ahola, Seppo E.

    2017-01-01

    Scientific evidence has recently been used to assert that certain psychological phenomena do not exist. Such claims, however, cannot be made because (1) scientific method itself is seriously limited (i.e., it can never prove a negative); (2) non-existence of phenomena would require a complete absence of both logical (theoretical) and empirical support; even if empirical support is weak, logical and theoretical support can be strong; (3) statistical data are only one piece of evidence and cannot be used to reduce psychological phenomena to statistical phenomena; and (4) psychological phenomena vary across time, situations and persons. The human mind is unreproducible from one situation to another. Psychological phenomena are not particles that can decisively be tested and discovered. Therefore, a declaration that a phenomenon is not real is not only theoretically and empirically unjustified but runs counter to the propositional and provisional nature of scientific knowledge. There are only “temporary winners” and no “final truths” in scientific knowledge. Psychology is a science of subtleties in human affect, cognition and behavior. Its phenomena fluctuate with conditions and may sometimes be difficult to detect and reproduce empirically. When strictly applied, reproducibility is an overstated and even questionable concept in psychological science. Furthermore, statistical measures (e.g., effect size) are poor indicators of the theoretical importance and relevance of phenomena (cf. “deliberate practice” vs. “talent” in expert performance), not to mention whether phenomena are real or unreal. To better understand psychological phenomena, their theoretical and empirical properties should be examined via multiple parameters and criteria. Ten such parameters are suggested. PMID:28626435

  2. Illusory Motion Reproduced by Deep Neural Networks Trained for Prediction

    Directory of Open Access Journals (Sweden)

    Eiji Watanabe

    2018-03-01

    Full Text Available The cerebral cortex predicts visual motion to adapt human behavior to surrounding objects moving in real time. Although the underlying mechanisms are still unknown, predictive coding is one of the leading theories. Predictive coding assumes that the brain's internal models (which are acquired through learning predict the visual world at all times and that errors between the prediction and the actual sensory input further refine the internal models. In the past year, deep neural networks based on predictive coding were reported for a video prediction machine called PredNet. If the theory substantially reproduces the visual information processing of the cerebral cortex, then PredNet can be expected to represent the human visual perception of motion. In this study, PredNet was trained with natural scene videos of the self-motion of the viewer, and the motion prediction ability of the obtained computer model was verified using unlearned videos. We found that the computer model accurately predicted the magnitude and direction of motion of a rotating propeller in unlearned videos. Surprisingly, it also represented the rotational motion for illusion images that were not moving physically, much like human visual perception. While the trained network accurately reproduced the direction of illusory rotation, it did not detect motion components in negative control pictures wherein people do not perceive illusory motion. This research supports the exciting idea that the mechanism assumed by the predictive coding theory is one of basis of motion illusion generation. Using sensory illusions as indicators of human perception, deep neural networks are expected to contribute significantly to the development of brain research.

  3. Reproducibility of thoracic kyphosis measurements in patients with adolescent idiopathic scoliosis.

    Science.gov (United States)

    Ohrt-Nissen, Søren; Cheung, Jason Pui Yin; Hallager, Dennis Winge; Gehrchen, Martin; Kwan, Kenny; Dahl, Benny; Cheung, Kenneth M C; Samartzis, Dino

    2017-01-01

    Current surgical treatment for adolescent idiopathic scoliosis (AIS) involves correction in both the coronal and sagittal plane, and thorough assessment of these parameters is essential for evaluation of surgical results. However, various definitions of thoracic kyphosis (TK) have been proposed, and the intra- and inter-rater reproducibility of these measures has not been determined. As such, the purpose of the current study was to determine the intra- and inter-rater reproducibility of several TK measurements used in the assessment of AIS. Twenty patients (90% females) surgically treated for AIS with alternate-level pedicle screw fixation were included in the study. Three raters independently evaluated pre- and postoperative standing lateral plain radiographs. For each radiograph, several definitions of TK were measured as well as L1-S1 and nonfixed lumbar lordosis. All variables were measured twice 14 days apart, and a mixed effects model was used to determine the repeatability coefficient (RC), which is a measure of the agreement between repeated measurements. Also, the intra- and inter-rater intra-class correlation coefficient (ICC) was determined as a measure of reliability. Preoperative median Cobb angle was 58° (range 41°-86°), and median surgical curve correction was 68% (range 49-87%). Overall intra-rater RC was highest for T2-T12 and nonfixed TK (11°) and lowest for T4-T12 and T5-T12 (8°). Inter-rater RC was highest for T1-T12, T1-nonfixed, and nonfixed TK (13°) and lowest for T5-T12 (9°). Agreement varied substantially between pre- and postoperative radiographs. Inter-rater ICC was highest for T4-T12 (0.92; 95% CI 0.88-0.95) and T5-T12 (0.92; 95% CI 0.88-0.95) and lowest for T1-nonfixed (0.80; 95% CI 0.72-0.88). Considerable variation for all TK measurements was noted. Intra- and inter-rater reproducibility was best for T4-T12 and T5-T12. Future studies should consider adopting a relevant minimum difference as a limit for true change in TK.

  4. Validity and reproducibility of the ErgomoPro power meter compared with the SRM and Powertap power meters.

    Science.gov (United States)

    Duc, Sebastien; Villerius, Vincent; Bertucci, William; Grappe, Frederic

    2007-09-01

    The ErgomoPro (EP) is a power meter that measures power output (PO) during outdoor and indoor cycling via 2 optoelectronic sensors located in the bottom bracket axis. The aim of this study was to determine the validity and the reproducibility of the EP compared with the SRM crank set and Powertap hub (PT). The validity of the EP was tested in the laboratory during 8 submaximal incremental tests (PO: 100 to 400 W), eight 30-min submaximal constant-power tests (PO = 180 W), and 8 sprint tests (PO > 750 W) and in the field during 8 training sessions (time: 181 +/- 73 min; PO: approximately 140 to 160 W). The reproducibility was assessed by calculating the coefficient of PO variation (CV) during the submaximal incremental and constant tests. The EP provided a significantly higher PO than the SRM and PT during the submaximal incremental test: The mean PO differences were +6.3% +/- 2.5% and +11.1% +/- 2.1% respectively. The difference was greater during field training sessions (+12.0% +/- 5.7% and +16.5% +/- 5.9%) but lower during sprint tests (+1.6% +/- 2.5% and +3.2% +/- 2.7%). The reproducibility of the EP is lower than those of the SRM and PT (CV = 4.1% +/- 1.8%, 1.9% +/- 0.4%, and 2.1% +/- 0.8%, respectively). The EP power meter appears less valid and reliable than the SRM and PT systems.

  5. Reproducibility of task activation using the Addenbrooke's cognitive examination in healthy controls: A functional Transcranial Doppler ultrasonography study.

    Science.gov (United States)

    Beishon, L; Williams, C A L; Panerai, R B; Robinson, T G; Haunton, V J

    2017-11-01

    Cerebral blood flow velocity (CBFv) changes occurring with cognitive stimulation can be measured by Transcranial Doppler ultrasonography (TCD). The aim of this study was to assess the reproducibility of CBFv changes to the Addenbrooke's cognitive examination (ACE-III). 13 volunteers underwent bilateral TCD (middle cerebral artery), continuous heart rate (HR, 3-lead ECG, Finometer), beat-to-beat mean arterial pressure (MAP, Finometer), and end-tidal CO 2 (ETCO 2 , capnography). After 5min baseline, all ACE-III tasks were performed in 3 domains (A/B/C). Data presented are population CBFv peak normalised changes and area under the curve (AUC). Statistical analysis was by 2-way repeated measures (ANOVA), intra-class correlation coefficient (ICC), standard error of measurement (SEM) and coefficient of variation (CV). 12 bilateral data sets were obtained (10 right hand dominant, 6 female). Baseline parameters (MAP, HR, ETCO 2 ) did not differ between visits. All tasks increased CBFv. Only domain A on AUC analysis differed significantly on ANOVA, and one task on post hoc testing (p examine reproducibility of CBFv changes to a complete cognitive assessment tool. Reproducibility of CBFv measurements to the ACE-III was variable. AUC may provide more reliable estimates than peak CBFv responses. These data need validating in patient populations. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Development of a Three-Dimensional Hand Model Using Three-Dimensional Stereophotogrammetry: Assessment of Image Reproducibility.

    Directory of Open Access Journals (Sweden)

    Inge A Hoevenaren

    Full Text Available Using three-dimensional (3D stereophotogrammetry precise images and reconstructions of the human body can be produced. Over the last few years, this technique is mainly being developed in the field of maxillofacial reconstructive surgery, creating fusion images with computed tomography (CT data for precise planning and prediction of treatment outcome. Though, in hand surgery 3D stereophotogrammetry is not yet being used in clinical settings.A total of 34 three-dimensional hand photographs were analyzed to investigate the reproducibility. For every individual, 3D photographs were captured at two different time points (baseline T0 and one week later T1. Using two different registration methods, the reproducibility of the methods was analyzed. Furthermore, the differences between 3D photos of men and women were compared in a distance map as a first clinical pilot testing our registration method.The absolute mean registration error for the complete hand was 1.46 mm. This reduced to an error of 0.56 mm isolating the region to the palm of the hand. When comparing hands of both sexes, it was seen that the male hand was larger (broader base and longer fingers than the female hand.This study shows that 3D stereophotogrammetry can produce reproducible images of the hand without harmful side effects for the patient, so proving to be a reliable method for soft tissue analysis. Its potential use in everyday practice of hand surgery needs to be further explored.

  7. OSS reliability measurement and assessment

    CERN Document Server

    Yamada, Shigeru

    2016-01-01

    This book analyses quantitative open source software (OSS) reliability assessment and its applications, focusing on three major topic areas: the Fundamentals of OSS Quality/Reliability Measurement and Assessment; the Practical Applications of OSS Reliability Modelling; and Recent Developments in OSS Reliability Modelling. Offering an ideal reference guide for graduate students and researchers in reliability for open source software (OSS) and modelling, the book introduces several methods of reliability assessment for OSS including component-oriented reliability analysis based on analytic hierarchy process (AHP), analytic network process (ANP), and non-homogeneous Poisson process (NHPP) models, the stochastic differential equation models and hazard rate models. These measurement and management technologies are essential to producing and maintaining quality/reliable systems using OSS.

  8. Transit ridership, reliability, and retention.

    Science.gov (United States)

    2008-10-01

    This project explores two major components that affect transit ridership: travel time reliability and rider : retention. It has been recognized that transit travel time reliability may have a significant impact on : attractiveness of transit to many ...

  9. Travel reliability inventory for Chicago.

    Science.gov (United States)

    2013-04-01

    The overarching goal of this research project is to enable state DOTs to document and monitor the reliability performance : of their highway networks. To this end, a computer tool, TRIC, was developed to produce travel reliability inventories from : ...

  10. Within-person reproducibility of red blood cell mercury over a 10- to 15-year period among women in the Nurses' Health Study II

    DEFF Research Database (Denmark)

    Kioumourtzoglou, Marianthi-Anna; Roberts, Andrea L; Nielsen, Flemming

    2016-01-01

    Most epidemiologic studies of methylmercury (MeHg) health effects rely on a single measurement of a MeHg biomarker to assess long-term exposures. Long-term reproducibility data are, therefore, needed to assess the reliability of a single measure to reflect long-term exposures. In this study, we...... assessed within-person reproducibility of red blood cell (RBC) mercury (Hg), a marker of methyl-mercury, over 10-15 years in a sample of 57 women. Fifty-seven women from the Nurses' Health Study II provided two blood samples 10-15-years apart (median: 12 years), which were analyzed for mercury levels...... in the red blood cells (B-Hg*). To characterize within-person reproducibility, we estimated correlation and intraclass correlation coefficients (r and ICC) across the two samples. Further, we compared different prediction models, including variables on fish and seafood consumption, for B-Hg* at the first...

  11. Short- and long-term quantitation reproducibility of brain metabolites in the medial wall using proton echo planar spectroscopic imaging.

    Science.gov (United States)

    Tsai, Shang-Yueh; Lin, Yi-Ru; Wang, Woan-Chyi; Niddam, David M

    2012-11-15

    Proton echo planar spectroscopic imaging (PEPSI) is a fast magnetic resonance spectroscopic imaging (MRSI) technique that allows mapping spatial metabolite distributions in the brain. Although the medial wall of the cortex is involved in a wide range of pathological conditions, previous MRSI studies have not focused on this region. To decide the magnitude of metabolic changes to be considered significant in this region, the reproducibility of the method needs to be established. The study aims were to establish the short- and long-term reproducibility of metabolites in the right medial wall and to compare regional differences using a constant short-echo time (TE30) and TE averaging (TEavg) optimized to yield glutamatergic information. 2D sagittal PEPSI was implemented at 3T using a 32 channel head coil. Acquisitions were repeated immediately and after approximately 2 weeks to assess the coefficients of variation (COV). COVs were obtained from eight regions-of-interest (ROIs) of varying size and location. TE30 resulted in better spectral quality and similar or lower quantitation uncertainty for all metabolites except glutamate (Glu). When Glu and glutamine (Gln) were quantified together (Glx) reduced quantitation uncertainty and increased reproducibility was observed for TE30. TEavg resulted in lowered quantitation uncertainty for Glu but in less reliable quantification of several other metabolites. TEavg did not result in a systematically improved short- or long-term reproducibility for Glu. The ROI volume was a major factor influencing reproducibility. For both short- and long-term repetitions, the Glu COVs obtained with TEavg were 5-8% for the large ROIs, 12-17% for the medium sized ROIs and 16-26% for the smaller cingulate ROIs. COVs obtained with TE30 for the less specific Glx were 3-5%, 8-10% and 10-15%. COVs for N-acetyl aspartate, creatine and choline using TE30 with long-term repetition were between 2-10%. Our results show that the cost of more specific

  12. 2017 NREL Photovoltaic Reliability Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-15

    NREL's Photovoltaic (PV) Reliability Workshop (PVRW) brings together PV reliability experts to share information, leading to the improvement of PV module reliability. Such improvement reduces the cost of solar electricity and promotes investor confidence in the technology -- both critical goals for moving PV technologies deeper into the electricity marketplace.

  13. AECL's reliability and maintainability program

    International Nuclear Information System (INIS)

    Wolfe, W.A.; Nieuwhof, G.W.E.

    1976-05-01

    AECL's reliability and maintainability program for nuclear generating stations is described. How the various resources of the company are organized to design and construct stations that operate reliably and safely is shown. Reliability and maintainability includes not only special mathematically oriented techniques, but also the technical skills and organizational abilities of the company. (author)

  14. From a formal training program in musculoskeletal ultrasound (MSUS) to a high reproducibility for Doppler ultrasound in rheumatoid arthritis.

    Science.gov (United States)

    Villota, Orlando; Diaz, Mario; Ceron, Carmen; Moller, Ingrid; Naredo, Esperanza; Saaibi, Diego Luis

    2017-07-28

    To assess the intra- and inter-observer reliability of ultrasound (US) in scoring B-mode, Doppler synovitis and combined B-mode and Doppler synovitis scores in different peripheral joints of rheumatoid arthritis (RA) patients. Four rheumatologists with a formal training in musculoskeletal US (MSKUS) particularly focus on definitions and scoring synovitis on B-mode and Doppler mode participated in a patient-based reliability exercise on 16 active RA patients. The four rheumatologists independently and consecutively performed a B-mode and power Doppler (PD) US assessment of 7 joints of each patient in two rounds in a blinded fashion. Each joint was semi quantitatively scored from 0 to 3 for B-mode synovitis (BS), Doppler synovitis (DS), and combined B-mode/Doppler synovitis (CS). Intraobserver reliability was assessed by Cohen's κ. Interobserver reliability was assessed by unweight Light's κ. The mean prevalence of synovitis on B-mode was 83% of joints; scores ranging from grade 1 in 18% of joints, to grade 3 in 33%. In 55% of joints synovial PD signal was detected and the distribution of scores range from 14% of joints for grade 3, to 26% for grade 2. After a total of 448 joints scanned with 896 adquired images our intraobserver and interobserver reliability was good to excellent for most of the joints. Formal, structured and continuous training in musculoskeletal ultrasound would bring a good to excellent reproducibility in rheumatological hands with a high reliability in real time acquisition BS, DS and CS modalities for scoring synovitis in patients with active rheumatoid arthritis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. IEEE guide for the analysis of human reliability

    International Nuclear Information System (INIS)

    Dougherty, E.M. Jr.

    1987-01-01

    The Institute of Electrical and Electronics Engineers (IEEE) working group 7.4 of the Human Factors and Control Facilities Subcommittee of the Nuclear Power Engineering Committee (NPEC) has released its fifth draft of a Guide for General Principles of Human Action Reliability Analysis for Nuclear Power Generating Stations, for approval of NPEC. A guide is the least mandating in the IEEE hierarchy of standards. The purpose is to enhance the performance of an human reliability analysis (HRA) as a part of a probabilistic risk assessment (PRA), to assure reproducible results, and to standardize documentation. The guide does not recommend or even discuss specific techniques, which are too rapidly evolving today. Considerable maturation in the analysis of human reliability in a PRA context has taken place in recent years. The IEEE guide on this subject is an initial step toward bringing HRA out of the research and development arena into the toolbox of standard engineering practices

  16. Business of reliability

    Science.gov (United States)

    Engel, Pierre

    1999-12-01

    The presentation is organized around three themes: (1) The decrease of reception equipment costs allows non-Remote Sensing organization to access a technology until recently reserved to scientific elite. What this means is the rise of 'operational' executive agencies considering space-based technology and operations as a viable input to their daily tasks. This is possible thanks to totally dedicated ground receiving entities focusing on one application for themselves, rather than serving a vast community of users. (2) The multiplication of earth observation platforms will form the base for reliable technical and financial solutions. One obstacle to the growth of the earth observation industry is the variety of policies (commercial versus non-commercial) ruling the distribution of the data and value-added products. In particular, the high volume of data sales required for the return on investment does conflict with traditional low-volume data use for most applications. Constant access to data sources supposes monitoring needs as well as technical proficiency. (3) Large volume use of data coupled with low- cost equipment costs is only possible when the technology has proven reliable, in terms of application results, financial risks and data supply. Each of these factors is reviewed. The expectation is that international cooperation between agencies and private ventures will pave the way for future business models. As an illustration, the presentation proposes to use some recent non-traditional monitoring applications, that may lead to significant use of earth observation data, value added products and services: flood monitoring, ship detection, marine oil pollution deterrent systems and rice acreage monitoring.

  17. Reliability of cervical vertebral maturation staging.

    Science.gov (United States)

    Rainey, Billie-Jean; Burnside, Girvan; Harrison, Jayne E

    2016-07-01

    Growth and its prediction are important for the success of many orthodontic treatments. The aim of this study was to determine the reliability of the cervical vertebral maturation (CVM) method for the assessment of mandibular growth. A group of 20 orthodontic clinicians, inexperienced in CVM staging, was trained to use the improved version of the CVM method for the assessment of mandibular growth with a teaching program. They independently assessed 72 consecutive lateral cephalograms, taken at Liverpool University Dental Hospital, on 2 occasions. The cephalograms were presented in 2 different random orders and interspersed with 11 additional images for standardization. The intraobserver and interobserver agreement values were evaluated using the weighted kappa statistic. The intraobserver and interobserver agreement values were substantial (weighted kappa, 0.6-0.8). The overall intraobserver agreement was 0.70 (SE, 0.01), with average agreement of 89%. The interobserver agreement values were 0.68 (SE, 0.03) for phase 1 and 0.66 (SE, 0.03) for phase 2, with average interobserver agreement of 88%. The intraobserver and interobserver agreement values of classifying the vertebral stages with the CVM method were substantial. These findings demonstrate that this method of CVM classification is reproducible and reliable. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  18. The Effect of Bite Registration on the Reproducibility of Parallel Periapical Radiographs Obtained with Two Month Intervals

    Directory of Open Access Journals (Sweden)

    L. Khojastehpour

    2006-06-01

    Full Text Available Statement of Problem: Digital Subtraction Radiography (DSR needs reproducible alignment between the x-ray source, the object, and the film for obtaining identical projections of the same anatomic region.Purpose: The aim of this study was to evaluate the effect of bite registrations (placed on individual bite blocks on the reproducibility of parallel periapical radiographs,obtained every 2 months, in patients undergoing periodontal surgery for furcationinvolvement.Materials and Methods: Ninety eight parallel periapical radiographs were used in this study. The radiographs were taken with individual bite-blocks attached to the beamguiding device. In order to individualize the bite blocks, bite registrations were fabricated using silicon impression material, and were placed on the individual bite blocks. All radiographs in each series were processed under similar conditions and were digitized with the flatbed scanner fitted with a transparency adaptor (hp Scanjet 7400 at 300 dpi resolution. Reproducibility of this method for obtaining similar parallel periapical radiographs was assessed by measuring the horizontal and vertical distances between two selected unchanged reference points on each radiograph and comparing them in each series. Reliability of measurements was analyzed using the one wayrandom model intraclass correlation coefficient for average of raters.Results: For both measurements (Horizontal and Vertical statistically significant reliability was found between three repeated radiographs with two month intervals in 16 patients, as well as 5 repeated radiographs with two month intervals in 10 patients (P<0.001.Conclusion: The result of this study shows that bite registration on individual bite blocks is enough for obtaining identical parallel periapical radiographs.

  19. Reproducibility of an aerobic endurance test for nonexpert swimmers

    Directory of Open Access Journals (Sweden)

    Veronese da Costa A

    2012-09-01

    Full Text Available Adalberto Veronese da Costa,1,2 Manoel da Cunha Costa,3 Daniel Medeiros Carlos,1 Luis Marcos de Medeiros Guerra,1,2 Antônio José Silva,2 Tiago Manoel Cabral dos Santos Barbosa2,41Department of Physical Education, Bioscience Laboratory of Human Kinetics, Rio Grande do Norte State University, Mossoró, Brazil; 2Sport Sciences Trás-os-Montes e Alto Douro University, Research Center in Sport, Health and Human Development, Vila Real, Portugal; 3Superior School of Physical Education, Human Performance Laboratory, Pernambuco State University, Recife, Brazil; 4National Institute of Education, Nanyang Technological University, SingaporeBackground: This study aimed to verify the reproduction of an aerobic test to determine nonexpert swimmers' resistance.Methods: The sample consisted of 24 male swimmers (age: 22.79 ± 3.90 years; weight: 74.72 ± 11.44 kg; height: 172.58 ± 4.99 cm; and fat percentage: 15.19% ± 3.21%, who swim for 1 hour three times a week. A new instrument was used in this study (a Progressive Swim Test: the swimmer wore an underwater MP3 player and increased their swimming speed on hearing a beep after every 25 meters. Each swimmer's heart rate was recorded before the test (BHR and again after the test (AHR. The rate of perceived exertion (RPE and the number of laps performed (NLP were also recorded. The sample size was estimated using G*Power software (v 3.0.10; Franz Faul, Kiel University, Kiel, Germany. The descriptive values were expressed as mean and standard deviation. After confirming the normality of the data using both the Shapiro–Wilk and Levene tests, a paired t-test was performed to compare the data. The Pearson's linear correlation (r and intraclass coefficient correlation (ICC tests were used to determine relative reproducibility. The standard error of measurement (SEM and the coefficient of variation (CV were used to determine absolute reproducibility. The limits of agreement and the bias of the absolute and relative

  20. Reproducibility between conventional and digital periapical radiography for bone height measurement

    Directory of Open Access Journals (Sweden)

    Miguel Simancas Pallares

    2015-10-01

    Conclusions. Reproducibility between methods was considered poor, including subgroup analysis, therefore, reproducibility between methods is minimal. Usage of these methods in periodontics should be made implementing the whole knowledge of the technical features and the advantages of these systems.

  1. Intra- and Interobserver Reliability of Three Classification Systems for Hallux Rigidus.

    Science.gov (United States)

    Dillard, Sarita; Schilero, Christina; Chiang, Sharon; Pham, Peter

    2018-04-18

    There are over ten classification systems currently used in the staging of hallux rigidus. This results in confusion and inconsistency with radiographic interpretation and treatment. The reliability of hallux rigidus classification systems has not yet been tested. The purpose of this study was to evaluate intra- and interobserver reliability using three commonly used classifications for hallux rigidus. Twenty-one plain radiograph sets were presented to ten ACFAS board-certified foot and ankle surgeons. Each physician classified each radiograph based on clinical experience and knowledge according to the Regnauld, Roukis, and Hattrup and Johnson classification systems. The two-way mixed single-measure consistency intraclass correlation was used to calculate intra- and interrater reliability. The intrarater reliability of individual sets for the Roukis and Hattrup and Johnson classification systems was "fair to good" (Roukis, 0.62±0.19; Hattrup and Johnson, 0.62±0.28), whereas the intrarater reliability of individual sets for the Regnauld system bordered between "fair to good" and "poor" (0.43±0.24). The interrater reliability of the mean classification was "excellent" for all three classification systems. Conclusions Reliable and reproducible classification systems are essential for treatment and prognostic implications in hallux rigidus. In our study, Roukis classification system had the best intrarater reliability. Although there are various classification systems for hallux rigidus, our results indicate that all three of these classification systems show reliability and reproducibility.

  2. Interobserver reproducibility of radiographic evaluation of lumbar spine instability.

    Science.gov (United States)

    Segundo, Saulo de Tarso de Sá Pereira; Valesin, Edgar Santiago; Lenza, Mario; Santos, Durval do Carmo Barros; Rosemberg, Laercio Alberto; Ferretti, Mario

    2016-01-01

    To measure the interobserver reproducibility of the radiographic evaluation of lumbar spine instability. Measurements of the dynamic radiographs of the lumbar spine in lateral view were performed, evaluating the anterior translation and the angulation among the vertebral bodies. The tests were evaluated at workstations of the organization, through the Carestream Health Vue RIS (PACS), version 11.0.12.14 Inc. 2009© system. Agreement in detecting cases of radiographic instability among the observers varied from 88.1 to 94.4%, and the agreement coefficients AC1 were all above 0.8, indicating excellent agreement. The interobserver analysis performed among orthopedic surgeons with different levels of training in dynamic radiographs of the spine obtained high reproducibility and agreement. However, some factors, such as the manual method of measurement and the presence of vertebral osteophytes, might have generated a few less accurate results in this comparative evaluation of measurements. Mensurar a reprodutibilidade interobservadores da avaliação radiográfica da instabilidade da coluna lombar. Foram realizadas mensurações das radiografias dinâmicas de coluna lombar na incidência em perfil, avaliando-se a translação anterior e a angulação entre os corpos vertebrais. Os exames foram avaliados em workstations da própria instituição, por meio do sistema Vue RIS (PACS) da Carestream Health, versão 11.0.12.14 Inc. 2009©. A proporção de concordância em detecção de casos de instabilidade radiográfica entre os observadores variou de 88,1 a 94,4%, e os coeficientes de concordância AC1 estiveram todos acima de 0,8, indicando concordância excelente. A análise interobservadores realizada entre médicos ortopedistas com diferentes níveis de treinamento em radiografias dinâmicas da coluna vertebral obteve elevada reprodutibilidade e concordância. No entanto, alguns fatores, como método manual de aferição e a presença de osteófitos vertebrais, podem

  3. Reproducing an extreme flood with uncertain post-event information

    Directory of Open Access Journals (Sweden)

    D. Fuentes-Andino

    2017-07-01

    Full Text Available Studies for the prevention and mitigation of floods require information on discharge and extent of inundation, commonly unavailable or uncertain, especially during extreme events. This study was initiated by the devastating flood in Tegucigalpa, the capital of Honduras, when Hurricane Mitch struck the city. In this study we hypothesized that it is possible to estimate, in a trustworthy way considering large data uncertainties, this extreme 1998 flood discharge and the extent of the inundations that followed from a combination of models and post-event measured data. Post-event data collected in 2000 and 2001 were used to estimate discharge peaks, times of peak, and high-water marks. These data were used in combination with rain data from two gauges to drive and constrain a combination of well-known modelling tools: TOPMODEL, Muskingum–Cunge–Todini routing, and the LISFLOOD-FP hydraulic model. Simulations were performed within the generalized likelihood uncertainty estimation (GLUE uncertainty-analysis framework. The model combination predicted peak discharge, times of peaks, and more than 90 % of the observed high-water marks within the uncertainty bounds of the evaluation data. This allowed an inundation likelihood map to be produced. Observed high-water marks could not be reproduced at a few locations on the floodplain. Identifications of these locations are useful to improve model set-up, model structure, or post-event data-estimation methods. Rainfall data were of central importance in simulating the times of peak and results would be improved by a better spatial assessment of rainfall, e.g. from radar data or a denser rain-gauge network. Our study demonstrated that it was possible, considering the uncertainty in the post-event data, to reasonably reproduce the extreme Mitch flood in Tegucigalpa in spite of no hydrometric gauging during the event. The method proposed here can be part of a Bayesian framework in which more events

  4. Electronics reliability calculation and design

    CERN Document Server

    Dummer, Geoffrey W A; Hiller, N

    1966-01-01

    Electronics Reliability-Calculation and Design provides an introduction to the fundamental concepts of reliability. The increasing complexity of electronic equipment has made problems in designing and manufacturing a reliable product more and more difficult. Specific techniques have been developed that enable designers to integrate reliability into their products, and reliability has become a science in its own right. The book begins with a discussion of basic mathematical and statistical concepts, including arithmetic mean, frequency distribution, median and mode, scatter or dispersion of mea

  5. Mathematical reliability an expository perspective

    CERN Document Server

    Mazzuchi, Thomas; Singpurwalla, Nozer

    2004-01-01

    In this volume consideration was given to more advanced theoretical approaches and novel applications of reliability to ensure that topics having a futuristic impact were specifically included. Topics like finance, forensics, information, and orthopedics, as well as the more traditional reliability topics were purposefully undertaken to make this collection different from the existing books in reliability. The entries have been categorized into seven parts, each emphasizing a theme that seems poised for the future development of reliability as an academic discipline with relevance. The seven parts are networks and systems; recurrent events; information and design; failure rate function and burn-in; software reliability and random environments; reliability in composites and orthopedics, and reliability in finance and forensics. Embedded within the above are some of the other currently active topics such as causality, cascading, exchangeability, expert testimony, hierarchical modeling, optimization and survival...

  6. Experiments in order to reproduce cold fusion results

    International Nuclear Information System (INIS)

    Bimbot, R.; Blain, G.; Boureau, G.; Cieur, M.

    1989-01-01

    Three experiments have been performed in order to try and reproduce the cold fusion experiments reported by FLEISCHMANN and PONS (D 2 O electrolysis) and by the Frascati Group (D 2 absorption in Ti at liquid nitrogen temperature). In the two electrolysis experiments, a Pd cathode was used together with a Pt anode and a Pd (D 2 ) reference electrode, in acid and basic media. The electrolysis cell was surrounded by four neutron counters filled with an organic scintillator (NE213). The electronics made it possible to discriminate neutrons from gamma rays. The global efficiency for neutron detection was 20%, and the detection threshold was equal to 1 neutron/s/4π. A germanium detector (efficiency 70%) and a NaI crystal were used to record gamma ray spectra. In one of the experiments, tritium was measured in the solution before and after electrolysis. None of the two experiments showed neutron, gamma, or tritium production above background. In the third experiment, deuterium was absorbed in titanium by cooling at liquid nitrogen temperature, and desorbed by warming up at room temperature; both neutron and gamma emissions were recorded during these operations. The results of this experiment were also negative [fr

  7. Reproducible microtechnique for measuring stimulation of human lymphocytes by phytohemagglutinin

    International Nuclear Information System (INIS)

    Willard, K.E.; Lloyd, E.L.

    1977-01-01

    Methods based on tritiated thymidine incorporation were used for studies on the blastogenic transformation of human lymphocytes by phytohemagglutinin (PHA) in vitro. A stimulation index was calculated as the ratio of the radioactivity measured in lymphocytes to which PHA had been added to that in similar samples from which PHA was omitted. The stimulation indices have been shown to be reproducible to within 10 percent for the same individuals sampled at different times. The maximum mitotic indices for normal control subjects varied from 249 to 340. Seven to 11 different concentrations of PHA were used with each blood sample tested. The maximum index occurred, for most samples, at concentrations of PHA between 0.0625 μl and 1.0 μl/well. A systematic decrease in the maximum mitotic indices was found with increasing age in the range tested (19 to 58 years). Measurements of the single radium case 03 to 416, aged 70, with a residual body burden of 1.0 μCi 226 Ra gave a maximum value for the mitotic index of 44 at a concentration of 0.25 μl/well. This was a factor of 5 less than the value expected from our normal control subjects

  8. The rapid reproducers paradox: population control and individual procreative rights.

    Science.gov (United States)

    Wissenburg, M

    1998-01-01

    This article argues that population policies need to be evaluated from macro and micro perspectives and to consider individual rights. Ecological arguments that are stringent conditions of liberal democracy are assessed against a moral standard. The moral standard is applied to a series of reasons for limiting procreative rights in the cause of sustainability. The focus is directly on legally enforced antinatalist measures and not on indirect policies with incentives and disincentives. The explicit assumption is that population policy violates the fairness to individuals for societal gain and that population policies are incompatible with stringent conditions of liberal democracy. The author identifies the individual-societal tradeoff as the "rapid reproducers paradox." The perfect sustainable population level is either not possible or is a repugnant alternative. 12 ecological arguments are presented, and none are found compatible with notions of a liberal democracy. Three alternative antinatalist options are the acceptance of less rigid and still coercive policies, amendments to the conception of liberal democracy, or loss of hope and choice of noncoercive solutions to sustainability, none of which is found viable. If voluntary abstinence and distributive solutions fail, then frugal demand options and technological supply options both will be necessary.

  9. Expanding probe repertoire and improving reproducibility in human genomic hybridization

    Science.gov (United States)

    Dorman, Stephanie N.; Shirley, Ben C.; Knoll, Joan H. M.; Rogan, Peter K.

    2013-01-01

    Diagnostic DNA hybridization relies on probes composed of single copy (sc) genomic sequences. Sc sequences in probe design ensure high specificity and avoid cross-hybridization to other regions of the genome, which could lead to ambiguous results that are difficult to interpret. We examine how the distribution and composition of repetitive sequences in the genome affects sc probe performance. A divide and conquer algorithm was implemented to design sc probes. With this approach, sc probes can include divergent repetitive elements, which hybridize to unique genomic targets under higher stringency experimental conditions. Genome-wide custom probe sets were created for fluorescent in situ hybridization (FISH) and microarray genomic hybridization. The scFISH probes were developed for detection of copy number changes within small tumour suppressor genes and oncogenes. The microarrays demonstrated increased reproducibility by eliminating cross-hybridization to repetitive sequences adjacent to probe targets. The genome-wide microarrays exhibited lower median coefficients of variation (17.8%) for two HapMap family trios. The coefficients of variations of commercial probes within 300 nt of a repetitive element were 48.3% higher than the nearest custom probe. Furthermore, the custom microarray called a chromosome 15q11.2q13 deletion more consistently. This method for sc probe design increases probe coverage for FISH and lowers variability in genomic microarrays. PMID:23376933

  10. High Reproducibility of ELISPOT Counts from Nine Different Laboratories

    Directory of Open Access Journals (Sweden)

    Srividya Sundararaman

    2015-01-01

    Full Text Available The primary goal of immune monitoring with ELISPOT is to measure the number of T cells, specific for any antigen, accurately and reproducibly between different laboratories. In ELISPOT assays, antigen-specific T cells secrete cytokines, forming spots of different sizes on a membrane with variable background intensities. Due to the subjective nature of judging maximal and minimal spot sizes, different investigators come up with different numbers. This study aims to determine whether statistics-based, automated size-gating can harmonize the number of spot counts calculated between different laboratories. We plated PBMC at four different concentrations, 24 replicates each, in an IFN-γ ELISPOT assay with HCMV pp65 antigen. The ELISPOT plate, and an image file of the plate was counted in nine different laboratories using ImmunoSpot® Analyzers by (A Basic Count™ relying on subjective counting parameters set by the respective investigators and (B SmartCount™, an automated counting protocol by the ImmunoSpot® Software that uses statistics-based spot size auto-gating with spot intensity auto-thresholding. The average coefficient of variation (CV for the mean values between independent laboratories was 26.7% when counting with Basic Count™, and 6.7% when counting with SmartCount™. Our data indicates that SmartCount™ allows harmonization of counting ELISPOT results between different laboratories and investigators.

  11. Virtual Raters for Reproducible and Objective Assessments in Radiology

    Science.gov (United States)

    Kleesiek, Jens; Petersen, Jens; Döring, Markus; Maier-Hein, Klaus; Köthe, Ullrich; Wick, Wolfgang; Hamprecht, Fred A.; Bendszus, Martin; Biller, Armin

    2016-04-01

    Volumetric measurements in radiologic images are important for monitoring tumor growth and treatment response. To make these more reproducible and objective we introduce the concept of virtual raters (VRs). A virtual rater is obtained by combining knowledge of machine-learning algorithms trained with past annotations of multiple human raters with the instantaneous rating of one human expert. Thus, he is virtually guided by several experts. To evaluate the approach we perform experiments with multi-channel magnetic resonance imaging (MRI) data sets. Next to gross tumor volume (GTV) we also investigate subcategories like edema, contrast-enhancing and non-enhancing tumor. The first data set consists of N = 71 longitudinal follow-up scans of 15 patients suffering from glioblastoma (GB). The second data set comprises N = 30 scans of low- and high-grade gliomas. For comparison we computed Pearson Correlation, Intra-class Correlation Coefficient (ICC) and Dice score. Virtual raters always lead to an improvement w.r.t. inter- and intra-rater agreement. Comparing the 2D Response Assessment in Neuro-Oncology (RANO) measurements to the volumetric measurements of the virtual raters results in one-third of the cases in a deviating rating. Hence, we believe that our approach will have an impact on the evaluation of clinical studies as well as on routine imaging diagnostics.

  12. Diet rapidly and reproducibly alters the human gut microbiome

    Science.gov (United States)

    David, Lawrence A.; Maurice, Corinne F.; Carmody, Rachel N.; Gootenberg, David B.; Button, Julie E.; Wolfe, Benjamin E.; Ling, Alisha V.; Devlin, A. Sloan; Varma, Yug; Fischbach, Michael A.; Biddinger, Sudha B.; Dutton, Rachel J.; Turnbaugh, Peter J.

    2013-01-01

    Long-term diet influences the structure and activity of the trillions of microorganisms residing in the human gut1–5, but it remains unclear how rapidly and reproducibly the human gut microbiome responds to short-term macronutrient change. Here, we show that the short-term consumption of diets composed entirely of animal or plant products alters microbial community structure and overwhelms inter-individual differences in microbial gene expression. The animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila, and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale, and Ruminococcus bromii). Microbial activity mirrored differences between herbivorous and carnivorous mammals2, reflecting trade-offs between carbohydrate and protein fermentation. Foodborne microbes from both diets transiently colonized the gut, including bacteria, fungi, and even viruses. Finally, increases in the abundance and activity of Bilophila wadsworthia on the animal-based diet support a link between dietary fat, bile acids, and the outgrowth of microorganisms capable of triggering inflammatory bowel disease6. In concert, these results demonstrate that the gut microbiome can rapidly respond to altered diet, potentially facilitating the diversity of human dietary lifestyles. PMID:24336217

  13. Histopathologic reproducibility of thyroid disease in an epidemiologic study

    International Nuclear Information System (INIS)

    Ron, E.; Griffel, B.; Liban, E.; Modan, B.

    1986-01-01

    An investigation of the long-term effects of childhood scalp irradiation demonstrated a significantly increased risk of thyroid tumors in the irradiated population. Because of the complexity of thyroid cancer diagnosis, a histopathologic slide review of 59 of the 68 patients (irradiated and nonirradiated) with thyroid disease was undertaken. The review revealed 90% agreement (kappa = +0.85, P less than 0.01) between the original and review diagnosis. Four of 27 cases previously diagnosed as malignant were reclassified as benign, yielding a cancer misdiagnosis rate of 14.8%. All four of the misdiagnosed cancers were of follicular or mixed papillary-follicular type. As a result of the histologic review, the ratio of malignant to benign tumors decreased from 2.55 to 1.75. Since disagreement in diagnosis was similar in the irradiated and nonirradiated groups, the relative risk of radiation-associated neoplasms did not change substantially. The histopathologic review shows that although there were some problems in diagnostic reproducibility, they were not statistically significant and did not alter our previous conclusions regarding radiation exposure. However, a 15% reduction in the number of malignancies might affect epidemiologic studies with an external comparison as well as geographic or temporal comparisons

  14. Finding reproducible cluster partitions for the k-means algorithm.

    Science.gov (United States)

    Lisboa, Paulo J G; Etchells, Terence A; Jarman, Ian H; Chambers, Simon J

    2013-01-01

    K-means clustering is widely used for exploratory data analysis. While its dependence on initialisation is well-known, it is common practice to assume that the partition with lowest sum-of-squares (SSQ) total i.e. within cluster variance, is both reproducible under repeated initialisations and also the closest that k-means can provide to true structure, when applied to synthetic data. We show that this is generally the case for small numbers of clusters, but for values of k that are still of theoretical and practical interest, similar values of SSQ can correspond to markedly different cluster partitions. This paper extends stability measures previously presented in the context of finding optimal values of cluster number, into a component of a 2-d map of the local minima found by the k-means algorithm, from which not only can values of k be identified for further analysis but, more importantly, it is made clear whether the best SSQ is a suitable solution or whether obtaining a consistently good partition requires further application of the stability index. The proposed method is illustrated by application to five synthetic datasets replicating a real world breast cancer dataset with varying data density, and a large bioinformatics dataset.

  15. A Kepler Workflow Tool for Reproducible AMBER GPU Molecular Dynamics.

    Science.gov (United States)

    Purawat, Shweta; Ieong, Pek U; Malmstrom, Robert D; Chan, Garrett J; Yeung, Alan K; Walker, Ross C; Altintas, Ilkay; Amaro, Rommie E

    2017-06-20

    With the drive toward high throughput molecular dynamics (MD) simulations involving ever-greater numbers of simulation replicates run for longer, biologically relevant timescales (microseconds), the need for improved computational methods that facilitate fully automated MD workflows gains more importance. Here we report the development of an automated workflow tool to perform AMBER GPU MD simulations. Our workflow tool capitalizes on the capabilities of the Kepler platform to deliver a flexible, intuitive, and user-friendly environment and the AMBER GPU code for a robust and high-performance simulation engine. Additionally, the workflow tool reduces user input time by automating repetitive processes and facilitates access to GPU clusters, whose high-performance processing power makes simulations of large numerical scale possible. The presented workflow tool facilitates the management and deployment of large sets of MD simulations on heterogeneous computing resources. The workflow tool also performs systematic analysis on the simulation outputs and enhances simulation reproducibility, execution scalability, and MD method development including benchmarking and validation. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  16. A reproducible brain tumour model established from human glioblastoma biopsies

    International Nuclear Information System (INIS)

    Wang, Jian; Chekenya, Martha; Bjerkvig, Rolf; Enger, Per Ø; Miletic, Hrvoje; Sakariassen, Per Ø; Huszthy, Peter C; Jacobsen, Hege; Brekkå, Narve; Li, Xingang; Zhao, Peng; Mørk, Sverre

    2009-01-01

    Establishing clinically relevant animal models of glioblastoma multiforme (GBM) remains a challenge, and many commonly used cell line-based models do not recapitulate the invasive growth patterns of patient GBMs. Previously, we have reported the formation of highly invasive tumour xenografts in nude rats from human GBMs. However, implementing tumour models based on primary tissue requires that these models can be sufficiently standardised with consistently high take rates. In this work, we collected data on growth kinetics from a material of 29 biopsies xenografted in nude rats, and characterised this model with an emphasis on neuropathological and radiological features. The tumour take rate for xenografted GBM biopsies were 96% and remained close to 100% at subsequent passages in vivo, whereas only one of four lower grade tumours engrafted. Average time from transplantation to the onset of symptoms was 125 days ± 11.5 SEM. Histologically, the primary xenografts recapitulated the invasive features of the parent tumours while endothelial cell proliferations and necrosis were mostly absent. After 4-5 in vivo passages, the tumours became more vascular with necrotic areas, but also appeared more circumscribed. MRI typically revealed changes related to tumour growth, several months prior to the onset of symptoms. In vivo passaging of patient GBM biopsies produced tumours representative of the patient tumours, with high take rates and a reproducible disease course. The model provides combinations of angiogenic and invasive phenotypes and represents a good alternative to in vitro propagated cell lines for dissecting mechanisms of brain tumour progression

  17. Can a coupled meteorology–chemistry model reproduce the ...

    Science.gov (United States)

    The ability of a coupled meteorology–chemistry model, i.e., Weather Research and Forecast and Community Multiscale Air Quality (WRF-CMAQ), to reproduce the historical trend in aerosol optical depth (AOD) and clear-sky shortwave radiation (SWR) over the Northern Hemisphere has been evaluated through a comparison of 21-year simulated results with observation-derived records from 1990 to 2010. Six satellite-retrieved AOD products including AVHRR, TOMS, SeaWiFS, MISR, MODIS-Terra and MODIS-Aqua as well as long-term historical records from 11 AERONET sites were used for the comparison of AOD trends. Clear-sky SWR products derived by CERES at both the top of atmosphere (TOA) and surface as well as surface SWR data derived from seven SURFRAD sites were used for the comparison of trends in SWR. The model successfully captured increasing AOD trends along with the corresponding increased TOA SWR (upwelling) and decreased surface SWR (downwelling) in both eastern China and the northern Pacific. The model also captured declining AOD trends along with the corresponding decreased TOA SWR (upwelling) and increased surface SWR (downwelling) in the eastern US, Europe and the northern Atlantic for the period of 2000–2010. However, the model underestimated the AOD over regions with substantial natural dust aerosol contributions, such as the Sahara Desert, Arabian Desert, central Atlantic and northern Indian Ocean. Estimates of the aerosol direct radiative effect (DRE) at TOA a

  18. From alginate impressions to digital virtual models: accuracy and reproducibility.

    Science.gov (United States)

    Dalstra, Michel; Melsen, Birte

    2009-03-01

    To compare the accuracy and reproducibility of measurements performed on digital virtual models with those taken on plaster casts from models poured immediately after the impression was taken, the 'gold standard', and from plaster models poured following a 3-5 day shipping procedure of the alginate impression. Direct comparison of two measuring techniques. The study was conducted at the Department of Orthodontics, School of Dentistry, University of Aarhus, Denmark in 2006/2007. Twelve randomly selected orthodontic graduate students with informed consent. Three sets of alginate impressions were taken from the participants within 1 hour. Plaster models were poured immediately from two of the sets, while the third set was kept in transit in the mail for 3-5 days. Upon return a plaster model was poured as well. Finally digital models were made from the plaster models. A number of measurements were performed on the plaster casts with a digital calliper and on the corresponding digital models using the virtual measuring tool of the accompanying software. Afterwards these measurements were compared statistically. No statistical differences were found between the three sets of plaster models. The intra- and inter-observer variability are smaller for the measurements performed on the digital models. Sending alginate impressions by mail does not affect the quality and accuracy of plaster casts poured from them afterwards. Virtual measurements performed on digital models display less variability than the corresponding measurements performed with a calliper on the actual models.

  19. Reproducibility of 3.0 Tesla Magnetic Resonance Spectroscopy for Measuring Hepatic Fat Content

    NARCIS (Netherlands)

    van Werven, Jochem R.; Hoogduin, Johannes M.; Nederveen, Aart J.; van Vliet, Andre A.; Wajs, Ewa; Vandenberk, Petra; Stroes, Erik S. G.; Stoker, Jaap

    Purpose: To investigate reproducibility of proton magnetic resonance spectroscopy (H-1-MRS) to measure hepatic triglyceride content (HTGC). Materials and Methods: In 24 subjects, HTGC was evaluated using H-1-MRS at 3.0 Tesla. We studied "between-weeks" reproducibility and reproducibility of H-1-MRS

  20. Of plants and reliability

    International Nuclear Information System (INIS)

    Schneider Horst

    2009-01-01

    Behind the political statements made about the transformer event at the Kruemmel nuclear power station (KKK) in the summer of 2009 there are fundamental issues of atomic law. Pursuant to Articles 20 and 28 of its Basic Law, Germany is a state in which the rule of law applies. Consequently, the aspects of atomic law associated with the incident merit a closer look, all the more so as the items concerned have been known for many years. Important aspects in the debate about the Kruemmel nuclear power plant are the fact that the transformer is considered part of the nuclear power station under atomic law and thus a ''plant'' subject to surveillance by the nuclear regulatory agencies, on the one hand, and the reliability under atomic law of the operator and the executive personnel responsible, on the other hand. Both ''plant'' and ''reliability'' are terms focusing on nuclear safety. Hence the question to what extent safety was affected in the Kruemmel incident. The classification of the event as 0 = no or only a very slight safety impact on the INES scale (INES = International Nuclear Event Scale) should not be used to put aside the safety issue once and for all. Points of fact and their technical significance must be considered prior to any legal assessment. Legal assessments and regulations are associated with facts and circumstances. Any legal examination is based on the facts as determined and elucidated. Any other procedure would be tantamount to an inadmissible legal advance conviction. Now, what is the position of political statements, i.e. political assessments and political responsibility? If everything is done the correct way, they come at the end, after exploration of the facts and evaluation under applicable law. Sometimes things are handled differently, with consequences which are not very helpful. In the light of the provisions about the rule of law as laid down in the Basic Law, the new federal government should be made to observe the proper sequence of

  1. Reproducibility over a 1-month period of 1H-MR spectroscopic imaging NAA/Cr ratios in clinically stable multiple sclerosis patients.

    Science.gov (United States)

    Mostert, J P; Blaauw, Y; Koch, M W; Kuiper, A J; Hoogduin, J M; De Keyser, J

    2008-08-01

    N-acetylaspartate/creatine (NAA/Cr) ratios, assessed with proton magnetic resonance spectroscopy, are increasingly used as a surrogate marker for axonal dysfunction and degeneration in multiple sclerosis (MS). The purpose of this study was to test short-time reproducibility of NAA/Cr ratios in patients with clinically stable MS. In 35 MS patients we analysed NAA/Cr ratios obtained with (1)H-MR spectroscopic imaging at the centrum semiovale either with lateral ventricles partially included (group 1; n=15) or more cranially with no ventricles included (group 2; n=20). To test short-term reproducibility of the NAA/Cr measurements, patients were scanned twice 4 weeks apart. We determined mean NAA/Cr and Cho/Cr ratios of 12 grey matter and 24 white matter voxels. Mean NAA/Cr ratios of both the white and grey matter did not change after 4 weeks. Overall 4-week reproducibility of the NAA/Cr ratio, expressed as coefficient of variation, was 4.8% for grey matter and 3.5% for white matter. Reproducibility of cranial scanning of the ventricles was slightly better than with cerebrospinal fluid included. Our study shows good short-term reproducibility of NAA/Cr ratio measurements in the centrum semiovale, which supports the reliability of this technique for longitudinal studies.

  2. Reproducible increased Mg incorporation and large hole concentration in GaN using metal modulated epitaxy

    International Nuclear Information System (INIS)

    Burnham, Shawn D.; Doolittle, W. Alan; Namkoong, Gon; Look, David C.; Clafin, Bruce

    2008-01-01

    The metal modulated epitaxy (MME) growth technique is reported as a reliable approach to obtain reproducible large hole concentrations in Mg-doped GaN grown by plasma-assisted molecular-beam epitaxy on c-plane sapphire substrates. An extremely Ga-rich flux was used, and modulated with the Mg source according to the MME growth technique. The shutter modulation approach of the MME technique allows optimal Mg surface coverage to build between MME cycles and Mg to incorporate at efficient levels in GaN films. The maximum sustained concentration of Mg obtained in GaN films using the MME technique was above 7x10 20 cm -3 , leading to a hole concentration as high as 4.5x10 18 cm -3 at room temperature, with a mobility of 1.1 cm 2 V -1 s -1 and a resistivity of 1.3 Ω cm. At 580 K, the corresponding values were 2.6x10 19 cm -3 , 1.2 cm 2 V -1 s -1 , and 0.21 Ω cm, respectively. Even under strong white light, the sample remained p-type with little change in the electrical parameters

  3. Reproducible increased Mg incorporation and large hole concentration in GaN using metal modulated epitaxy

    Science.gov (United States)

    Burnham, Shawn D.; Namkoong, Gon; Look, David C.; Clafin, Bruce; Doolittle, W. Alan

    2008-07-01

    The metal modulated epitaxy (MME) growth technique is reported as a reliable approach to obtain reproducible large hole concentrations in Mg-doped GaN grown by plasma-assisted molecular-beam epitaxy on c-plane sapphire substrates. An extremely Ga-rich flux was used, and modulated with the Mg source according to the MME growth technique. The shutter modulation approach of the MME technique allows optimal Mg surface coverage to build between MME cycles and Mg to incorporate at efficient levels in GaN films. The maximum sustained concentration of Mg obtained in GaN films using the MME technique was above 7×1020cm-3, leading to a hole concentration as high as 4.5×1018cm-3 at room temperature, with a mobility of 1.1cm2V-1s-1 and a resistivity of 1.3Ωcm. At 580K, the corresponding values were 2.6×1019cm-3, 1.2cm2V-1s-1, and 0.21Ωcm, respectively. Even under strong white light, the sample remained p-type with little change in the electrical parameters.

  4. Design Procedure and Fabrication of Reproducible Silicon Vernier Devices for High-Performance Refractive Index Sensing.

    Science.gov (United States)

    Troia, Benedetto; Khokhar, Ali Z; Nedeljkovic, Milos; Reynolds, Scott A; Hu, Youfang; Mashanovich, Goran Z; Passaro, Vittorio M N

    2015-06-10

    In this paper, we propose a generalized procedure for the design of integrated Vernier devices for high performance chemical and biochemical sensing. In particular, we demonstrate the accurate control of the most critical design and fabrication parameters of silicon-on-insulator cascade-coupled racetrack resonators operating in the second regime of the Vernier effect, around 1.55 μm. The experimental implementation of our design strategies has allowed a rigorous and reliable investigation of the influence of racetrack resonator and directional coupler dimensions as well as of waveguide process variability on the operation of Vernier devices. Figures of merit of our Vernier architectures have been measured experimentally, evidencing a high reproducibility and a very good agreement with the theoretical predictions, as also confirmed by relative errors even lower than 1%. Finally, a Vernier gain as high as 30.3, average insertion loss of 2.1 dB and extinction ratio up to 30 dB have been achieved.

  5. Expression microarray reproducibility is improved by optimising purification steps in RNA amplification and labelling

    Directory of Open Access Journals (Sweden)

    Brenton James D

    2004-01-01

    Full Text Available Abstract Background Expression microarrays have evolved into a powerful tool with great potential for clinical application and therefore reliability of data is essential. RNA amplification is used when the amount of starting material is scarce, as is frequently the case with clinical samples. Purification steps are critical in RNA amplification and labelling protocols, and there is a lack of sufficient data to validate and optimise the process. Results Here the purification steps involved in the protocol for indirect labelling of amplified RNA are evaluated and the experimentally determined best method for each step with respect to yield, purity, size distribution of the transcripts, and dye coupling is used to generate targets tested in replicate hybridisations. DNase treatment of diluted total RNA samples followed by phenol extraction is the optimal way to remove genomic DNA contamination. Purification of double-stranded cDNA is best achieved by phenol extraction followed by isopropanol precipitation at room temperature. Extraction with guanidinium-phenol and Lithium Chloride precipitation are the optimal methods for purification of amplified RNA and labelled aRNA respectively. Conclusion This protocol provides targets that generate highly reproducible microarray data with good representation of transcripts across the size spectrum and a coefficient of repeatability significantly better than that reported previously.

  6. Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

    International Nuclear Information System (INIS)

    Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; Shigueoka, David Carlos; D'Ippolito, Giuseppe; Colleoni, Ramiro

    2008-01-01

    Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

  7. Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

    Energy Technology Data Exchange (ETDEWEB)

    Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; Shigueoka, David Carlos; D' Ippolito, Giuseppe [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Diagnostico por Imagem]. E-mail: ar.leao@uol.com.br; Colleoni, Ramiro [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Gastroenterologia

    2008-09-15

    Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

  8. Multinomial-exponential reliability function: a software reliability model

    International Nuclear Information System (INIS)

    Saiz de Bustamante, Amalio; Saiz de Bustamante, Barbara

    2003-01-01

    The multinomial-exponential reliability function (MERF) was developed during a detailed study of the software failure/correction processes. Later on MERF was approximated by a much simpler exponential reliability function (EARF), which keeps most of MERF mathematical properties, so the two functions together makes up a single reliability model. The reliability model MERF/EARF considers the software failure process as a non-homogeneous Poisson process (NHPP), and the repair (correction) process, a multinomial distribution. The model supposes that both processes are statistically independent. The paper discusses the model's theoretical basis, its mathematical properties and its application to software reliability. Nevertheless it is foreseen model applications to inspection and maintenance of physical systems. The paper includes a complete numerical example of the model application to a software reliability analysis

  9. Reliability, factor analysis and internal consistency calculation of the Insomnia Severity Index (ISI in French and in English among Lebanese adolescents

    Directory of Open Access Journals (Sweden)

    M. Chahoud

    2017-06-01

    Conclusion: The results of our analyses reveal that both English and French versions of the ISI scale have good internal consistency and are reproducible and reliable. Therefore, it can be used to assess the prevalence of insomnia in Lebanese adolescents.

  10. Test-Retest Reproducibility of the Microperimeter MP3 With Fundus Image Tracking in Healthy Subjects and Patients With Macular Disease.

    Science.gov (United States)

    Palkovits, Stefan; Hirnschall, Nino; Georgiev, Stefan; Leisser, Christoph; Findl, Oliver

    2018-02-01

    To evaluate the test-retest reproducibility of a novel microperimeter with fundus image tracking (MP3, Nidek Co, Japan) in healthy subjects and patients with macular disease. Ten healthy subjects and 20 patients suffering from range of macular diseases were included. After training measurements, two additional microperimetry measurements were scheduled. Test-retest reproducibility was assessed for mean retinal sensitivity, pointwise sensitivity, and deep scotoma size using the coefficient of repeatability and Bland-Altman diagrams. In addition, in a subgroup of patients microperimetry was compared with conventional perimetry. Average differences in mean retinal sensitivity between the two study measurements were 0.26 ± 1.7 dB (median 0 dB; interquartile range [IQR] -1 to 1) for the healthy and 0.36 ± 2.5 dB (median 0 dB; IQR -1 to 2) for the macular patient group. Coefficients of repeatability for mean retinal sensitivity and pointwise retinal sensitivity were 1.2 and 3.3 dB for the healthy subjects and 1.6 and 5.0 dB for the macular disease patients, respectively. Absolute agreement in deep scotoma size between both study days was found in 79.9% of the test loci. The microperimeter MP3 shows an adequate test-retest reproducibility for mean retinal sensitivity, pointwise retinal sensitivity, and deep scotoma size in healthy subjects and patients suffering from macular disease. Furthermore, reproducibility of microperimetry is higher than conventional perimetry. Reproducibility is an important measure for each diagnostic device. Especially in a clinical setting high reproducibility set the basis to achieve reliable results using the specific device. Therefore, assessment of the reproducibility is of eminent importance to interpret the findings of future studies.

  11. Test–Retest Reproducibility of the Microperimeter MP3 With Fundus Image Tracking in Healthy Subjects and Patients With Macular Disease

    Science.gov (United States)

    Palkovits, Stefan; Hirnschall, Nino; Georgiev, Stefan; Leisser, Christoph

    2018-01-01

    Purpose To evaluate the test–retest reproducibility of a novel microperimeter with fundus image tracking (MP3, Nidek Co, Japan) in healthy subjects and patients with macular disease. Methods Ten healthy subjects and 20 patients suffering from range of macular diseases were included. After training measurements, two additional microperimetry measurements were scheduled. Test–retest reproducibility was assessed for mean retinal sensitivity, pointwise sensitivity, and deep scotoma size using the coefficient of repeatability and Bland-Altman diagrams. In addition, in a subgroup of patients microperimetry was compared with conventional perimetry. Results Average differences in mean retinal sensitivity between the two study measurements were 0.26 ± 1.7 dB (median 0 dB; interquartile range [IQR] −1 to 1) for the healthy and 0.36 ± 2.5 dB (median 0 dB; IQR −1 to 2) for the macular patient group. Coefficients of repeatability for mean retinal sensitivity and pointwise retinal sensitivity were 1.2 and 3.3 dB for the healthy subjects and 1.6 and 5.0 dB for the macular disease patients, respectively. Absolute agreement in deep scotoma size between both study days was found in 79.9% of the test loci. Conclusion The microperimeter MP3 shows an adequate test–retest reproducibility for mean retinal sensitivity, pointwise retinal sensitivity, and deep scotoma size in healthy subjects and patients suffering from macular disease. Furthermore, reproducibility of microperimetry is higher than conventional perimetry. Translational Relevance Reproducibility is an important measure for each diagnostic device. Especially in a clinical setting high reproducibility set the basis to achieve reliable results using the specific device. Therefore, assessment of the reproducibility is of eminent importance to interpret the findings of future studies. PMID:29430338

  12. Quality assurance and reliability

    International Nuclear Information System (INIS)

    Normand, J.; Charon, M.

    1975-01-01

    Concern for obtaining high-quality products which will function properly when required to do so is nothing new - it is one manifestation of a conscientious attitude to work. However, the complexity and cost of equipment and the consequences of even temporary immobilization are such that it has become necessary to make special arrangements for obtaining high-quality products and examining what one has obtained. Each unit within an enterprise must examine its own work or arrange for it to be examined; a unit whose specific task is quality assurance is responsible for overall checking, but does not relieve other units of their responsibility. Quality assurance is a form of mutual assistance within an enterprise, designed to remove the causes of faults as far as possible. It begins very early in a project and continues through the ordering stage, construction, start-up trials and operation. Quality and hence reliability are the direct result of what is done at all stages of a project. They depend on constant attention to detail, for even a minor piece of poor workmanship can, in the case of an essential item of equipment, give rise to serious operational difficulties

  13. Reliability of Oronasal Fistula Classification.

    Science.gov (United States)

    Sitzman, Thomas J; Allori, Alexander C; Matic, Damir B; Beals, Stephen P; Fisher, David M; Samson, Thomas D; Marcus, Jeffrey R; Tse, Raymond W

    2018-01-01

    Objective Oronasal fistula is an important complication of cleft palate repair that is frequently used to evaluate surgical quality, yet reliability of fistula classification has never been examined. The objective of this study was to determine the reliability of oronasal fistula classification both within individual surgeons and between multiple surgeons. Design Using intraoral photographs of children with repaired cleft palate, surgeons rated the location of palatal fistulae using the Pittsburgh Fistula Classification System. Intrarater and interrater reliability scores were calculated for each region of the palate. Participants Eight cleft surgeons rated photographs obtained from 29 children. Results Within individual surgeons reliability for each region of the Pittsburgh classification ranged from moderate to almost perfect (κ = .60-.96). By contrast, reliability between surgeons was lower, ranging from fair to substantial (κ = .23-.70). Between-surgeon reliability was lowest for the junction of the soft and hard palates (κ = .23). Within-surgeon and between-surgeon reliability were almost perfect for the more general classification of fistula in the secondary palate (κ = .95 and κ = .83, respectively). Conclusions This is the first reliability study of fistula classification. We show that the Pittsburgh Fistula Classification System is reliable when used by an individual surgeon, but less reliable when used among multiple surgeons. Comparisons of fistula occurrence among surgeons may be subject to less bias if they use the more general classification of "presence or absence of fistula of the secondary palate" rather than the Pittsburgh Fistula Classification System.

  14. Dependent systems reliability estimation by structural reliability approach

    DEFF Research Database (Denmark)

    Kostandyan, Erik; Sørensen, John Dalsgaard

    2014-01-01

    Estimation of system reliability by classical system reliability methods generally assumes that the components are statistically independent, thus limiting its applicability in many practical situations. A method is proposed for estimation of the system reliability with dependent components, where...... the leading failure mechanism(s) is described by physics of failure model(s). The proposed method is based on structural reliability techniques and accounts for both statistical and failure effect correlations. It is assumed that failure of any component is due to increasing damage (fatigue phenomena...... identification. Application of the proposed method can be found in many real world systems....

  15. Accuracy and reproducibility of IOLMaster versus contact ultrasound biometry

    Directory of Open Access Journals (Sweden)

    Quan-Hao Bai

    2015-06-01

    Full Text Available AIM: To compare biometry results of IOLMaster and contact ultrasound(USanterior segment parameters, and to evaluate the calculation accuracy and repeatability of intraocular lens power in both.METHODS: Preoperative measurement of anterior segment parameters were prospectively obtained in 137 eyes of 121 subjects with the IOLMaster compared with the US. Postoperative best corrected visual acuity(BCVAand the actual diopter were measured.RESULTS: There was an excellent correlation between IOLMaster and US measurements for the ACD(r=0.823, Pr=0.996, PPCONCLUSION: Partial coherence biometry using the IOLMaster provides the more accurate and reliable anterior segment parameters measurement values. A high degree of agreement between US and IOLMaster is noted. The IOLMaster not only has the advantage of performing noncontact examinations, but also produces various additional data simultaneously and may thus obviate the need for multiple examinations.

  16. Reproducibility of step tests in patients with bronchiectasis

    Directory of Open Access Journals (Sweden)

    Anderson A. Camargo

    2013-06-01

    Full Text Available BACKGROUND: The step test has been used to assess exercise capacity in patients with chronic respiratory disease; however, its use has not been described with regard to patients with bronchiectasis (BCT. OBJECTIVE: This study assessed the reliability of the Chester step test (CST and the modified incremental step test (MIST and also correlated these tests with pulmonary function, heart rate (HR, and distance walked during the 6-min walk test (6-MWT. METHOD: On separate days, 17 patients randomly underwent two CSTs, two MISTs, and two 6-MWTs. Number of steps (NOSs, HR, and perceived exertion were recorded immediately before and after these tests. RESULTS: NOSs were similar across CSTs (124±65 and 125±67 and MISTs (158±83 and 156±76. Differences were not found across the CSTs and MISTs with regard to HR (138±25 bpm and 136±27 bpm, SpO2 (91±5% and 91±3%, perceived exertion (dyspnea=4 [3-5] and 4 [2-4.5] and fatigue (4 [2-6] and 4 [3-5]. The CST was significantly briefer than the MIST (6.0±2.2 min and 8.6±3.0 min and had fewer associated NOS (125±67 and 158±83. NOSs were correlated with FEV1, the 6-MWD, and HR for both tests. CONCLUSIONS: The CST and MIST are reliable in patients with BCT. Patients tolerated the MIST more than the CST. Better lung function and 6-MWT scores predicted the greater NOSs and greater peak HR.

  17. Reproducing American Sign Language Sentences: Cognitive Scaffolding in Working Memory

    Directory of Open Access Journals (Sweden)

    Ted eSupalla

    2014-08-01

    Full Text Available The American Sign Language Sentence Reproduction Test (ASL-SRT requires the precise reproduction of a series of ASL sentences increasing in complexity and length. Error analyses of such tasks provides insight into working memory and scaffolding processes. Data was collected from three groups expected to differ in fluency: deaf children, deaf adults and hearing adults, all users of ASL. Quantitative (correct/incorrect recall and qualitative error analyses were performed. Percent correct on the reproduction task supports its sensitivity to fluency as test performance clearly differed across the three groups studied. A linguistic analysis of errors further documented differing strategies and bias across groups. Subjects’ recall projected the affordance and constraints of deep linguistic representations to differing degrees, with subjects resorting to alternate processing strategies in the absence of linguistic knowledge. A qualitative error analysis allows us to capture generalizations about the relationship between error pattern and the cognitive scaffolding, which governs the sentence reproduction process. Highly fluent signers and less-fluent signers share common chokepoints on particular words in sentences. However, they diverge in heuristic strategy. Fluent signers, when they make an error, tend to preserve semantic details while altering morpho-syntactic domains. They produce syntactically correct sentences with equivalent meaning to the to-be-reproduced one, but these are not verbatim reproductions of the original sentence. In contrast, less-fluent signers tend to use a more linear strategy, preserving lexical status and word ordering while omitting local inflections, and occasionally resorting to visuo-motoric imitation. Thus, whereas fluent signers readily use top-down scaffolding in their working memory, less fluent signers fail to do so. Implications for current models of working memory across spoken and signed modalities are

  18. Finite-rank potential that reproduces the Pade approximant

    International Nuclear Information System (INIS)

    Tani, S.

    1979-01-01

    If a scattering potential is of a finite rank, say N, the exact solution of the problem can be obtained from the Born series, if the potential strength is within the radius of convergence; the exact solution can be obtained from the analytical continuation of the formal Born series outside the radius of convergence. Beyond the first 2N terms of the Born series, an individual term of the Born series depends on the first 2N terms, and the [N/N] Pade approximant and the exact solution agree with each other. The above-mentioned features of a finite-rank problem are relevant to scattering theory in general, because most scattering problems may be handled as an extension of the rank-N problem, in which the rank N tends to infinity. The foregoing aspects of scattering theory will be studied in depth in the present paper, and in so doing we proceed in the opposite direction. Namely, given a potential, we calculate the first 2N terms of the Born series for the K matrix and the first N terms of the Born series for the wave function. Using these data, a special rank-N potential is constructed in such a way that it reproduces the [N/N] Pade approximant of the K matrix of the original scattering problem. One great advantage of obtaining such a rank-N potential is that the wave function of the system may be approximated in the same spirit as done for the K matrix; hence, we can introduce a new approximation method for dealing with an off-shell T matrix. A part of the mathematical work is incomplete, but the physical aspects are thoroughly discussed

  19. A reproducible brain tumour model established from human glioblastoma biopsies

    Directory of Open Access Journals (Sweden)

    Li Xingang

    2009-12-01

    Full Text Available Abstract Background Establishing clinically relevant animal models of glioblastoma multiforme (GBM remains a challenge, and many commonly used cell line-based models do not recapitulate the invasive growth patterns of patient GBMs. Previously, we have reported the formation of highly invasive tumour xenografts in nude rats from human GBMs. However, implementing tumour models based on primary tissue requires that these models can be sufficiently standardised with consistently high take rates. Methods In this work, we collected data on growth kinetics from a material of 29 biopsies xenografted in nude rats, and characterised this model with an emphasis on neuropathological and radiological features. Results The tumour take rate for xenografted GBM biopsies were 96% and remained close to 100% at subsequent passages in vivo, whereas only one of four lower grade tumours engrafted. Average time from transplantation to the onset of symptoms was 125 days ± 11.5 SEM. Histologically, the primary xenografts recapitulated the invasive features of the parent tumours while endothelial cell proliferations and necrosis were mostly absent. After 4-5 in vivo passages, the tumours became more vascular with necrotic areas, but also appeared more circumscribed. MRI typically revealed changes related to tumour growth, several months prior to the onset of symptoms. Conclusions In vivo passaging of patient GBM biopsies produced tumours representative of the patient tumours, with high take rates and a reproducible disease course. The model provides combinations of angiogenic and invasive phenotypes and represents a good alternative to in vitro propagated cell lines for dissecting mechanisms of brain tumour progression.

  20. Soft and hard classification by reproducing kernel Hilbert space methods.

    Science.gov (United States)

    Wahba, Grace

    2002-12-24

    Reproducing kernel Hilbert space (RKHS) methods provide a unified context for solving a wide variety of statistical modelling and function estimation problems. We consider two such problems: We are given a training set [yi, ti, i = 1, em leader, n], where yi is the response for the ith subject, and ti is a vector of attributes for this subject. The value of y(i) is a label that indicates which category it came from. For the first problem, we wish to build a model from the training set that assigns to each t in an attribute domain of interest an estimate of the probability pj(t) that a (future) subject with attribute vector t is in category j. The second problem is in some sense less ambitious; it is to build a model that assigns to each t a label, which classifies a future subject with that t into one of the categories or possibly "none of the above." The approach to the first of these two problems discussed here is a special case of what is known as penalized likelihood estimation. The approach to the second problem is known as the support vector machine. We also note some alternate but closely related approaches to the second problem. These approaches are all obtained as solutions to optimization problems in RKHS. Many other problems, in particular the solution of ill-posed inverse problems, can be obtained as solutions to optimization problems in RKHS and are mentioned in passing. We caution the reader that although a large literature exists in all of these topics, in this inaugural article we are selectively highlighting work of the author, former students, and other collaborators.

  1. Reliability of reactor materials

    International Nuclear Information System (INIS)

    Toerroenen, K.; Aho-Mantila, I.

    1986-05-01

    This report is the final technical report of the fracture mechanics part of the Reliability of Reactor Materials Programme, which was carried out at the Technical Research Centre of Finland (VTT) through the years 1981 to 1983. Research and development work was carried out in five major areas, viz. statistical treatment and modelling of cleavage fracture, crack arrest, ductile fracture, instrumented impact testing as well as comparison of numerical and experimental elastic-plastic fracture mechanics. In the area of cleavage fracture the critical variables affecting the fracture of steels are considered in the frames of a statistical model, so called WST-model. Comparison of fracture toughness values predicted by the model and corresponding experimental values shows excellent agreement for a variety of microstructures. different posibilities for using the model are discussed. The development work in the area of crack arrest testing was concentrated in the crack starter properties, test arrangement and computer control. A computerized elastic-plastic fracture testing method with a variety of test specimen geometries in a large temperature range was developed for a routine stage. Ductile fracture characteristics of reactor pressure vessel steel A533B and comparable weld material are given. The features of a new, patented instrumented impact tester are described. Experimental and theoretical comparisons between the new and conventional testers indicated clearly the improvements achieved with the new tester. A comparison of numerical and experimental elastic-plastic fracture mechanics capabilities at VTT was carried out. The comparison consisted of two-dimensional linear elastic as well as elastic-plastic finite element analysis of four specimen geometries and equivalent experimental tests. (author)

  2. Field reliability of electronic systems

    International Nuclear Information System (INIS)

    Elm, T.

    1984-02-01

    This report investigates, through several examples from the field, the reliability of electronic units in a broader sense. That is, it treats not just random parts failure, but also inadequate reliability design and (externally and internally) induced failures. The report is not meant to be merely an indication of the state of the art for the reliability prediction methods we know, but also as a contribution to the investigation of man-machine interplay in the operation and repair of electronic equipment. The report firmly links electronics reliability to safety and risk analyses approaches with a broader, system oriented view of reliability prediction and with postfailure stress analysis. It is intended to reveal, in a qualitative manner, the existence of symptom and cause patterns. It provides a background for further investigations to identify the detailed mechanisms of the faults and the remedical actions and precautions for achieving cost effective reliability. (author)

  3. Reliability Assessment Of Wind Turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2014-01-01

    Reduction of cost of energy for wind turbines are very important in order to make wind energy competitive compared to other energy sources. Therefore the turbine components should be designed to have sufficient reliability but also not be too costly (and safe). This paper presents models...... for uncertainty modeling and reliability assessment of especially the structural components such as tower, blades, substructure and foundation. But since the function of a wind turbine is highly dependent on many electrical and mechanical components as well as a control system also reliability aspects...... of these components are discussed and it is described how there reliability influences the reliability of the structural components. Two illustrative examples are presented considering uncertainty modeling, reliability assessment and calibration of partial safety factors for structural wind turbine components exposed...

  4. Reliability engineering theory and practice

    CERN Document Server

    Birolini, Alessandro

    2014-01-01

    This book shows how to build in, evaluate, and demonstrate reliability and availability of components, equipment, systems. It presents the state-of-theart of reliability engineering, both in theory and practice, and is based on the author's more than 30 years experience in this field, half in industry and half as Professor of Reliability Engineering at the ETH, Zurich. The structure of the book allows rapid access to practical results. This final edition extend and replace all previous editions. New are, in particular, a strategy to mitigate incomplete coverage, a comprehensive introduction to human reliability with design guidelines and new models, and a refinement of reliability allocation, design guidelines for maintainability, and concepts related to regenerative stochastic processes. The set of problems for homework has been extended. Methods & tools are given in a way that they can be tailored to cover different reliability requirement levels and be used for safety analysis. Because of the Appendice...

  5. Reliability of Wireless Sensor Networks

    Science.gov (United States)

    Dâmaso, Antônio; Rosa, Nelson; Maciel, Paulo

    2014-01-01

    Wireless Sensor Networks (WSNs) consist of hundreds or thousands of sensor nodes with limited processing, storage, and battery capabilities. There are several strategies to reduce the power consumption of WSN nodes (by increasing the network lifetime) and increase the reliability of the network (by improving the WSN Quality of Service). However, there is an inherent conflict between power consumption and reliability: an increase in reliability usually leads to an increase in power consumption. For example, routing algorithms can send the same packet though different paths (multipath strategy), which it is important for reliability, but they significantly increase the WSN power consumption. In this context, this paper proposes a model for evaluating the reliability of WSNs considering the battery level as a key factor. Moreover, this model is based on routing algorithms used by WSNs. In order to evaluate the proposed models, three scenarios were considered to show the impact of the power consumption on the reliability of WSNs. PMID:25157553

  6. Short- and long-term reproducibility of radioisotopic examination of gastric emptying

    Energy Technology Data Exchange (ETDEWEB)

    Jonderko, K. (Silesian School of Medicine, Katowice (Poland). Dept. of Gastroenterology)

    1990-01-01

    Reproducibility of gastric emptying (GE) of a radiolabelled solid meal was assessed. The short-term reproducibility was evaluated on the basis of 12 paired GE examinations performed 1-3 days apart. Twelve paired GE examinations taken 3-8 months apart enabled long-term reproducibility assessment. Reproducibility of GE parameters was expressed in terms of the coefficient of variation, CV. No significant between-day variation of solid GE was found either regarding the short-term or the long-term reproducibility. Although slightly higher CV values characterized the long-term reproducibility of the GE parameters considered, the variations of the differences between repeated GE examinations did not differ significantly between short- and long-term GE reproducibility. The results obtained justify the use of radioisotopic GE measurement for the assessment of early and late results of pharmacologic or surgical management. (author).

  7. Reliability of numerical wind tunnels for VAWT simulation

    International Nuclear Information System (INIS)

    Castelli, M. Raciti; Masi, M.; Battisti, L.; Benini, E.; Brighenti, A.; Dossena, V.; Persico, G.

    2016-01-01

    Computational Fluid Dynamics (CFD) based on the Unsteady Reynolds Averaged Navier Stokes (URANS) equations have long been widely used to study vertical axis wind turbines (VAWTs). Following a comprehensive experimental survey on the wakes downwind of a troposkien-shaped rotor, a campaign of bi-dimensional simulations is presented here, with the aim of assessing its reliability in reproducing the main features of the flow, also identifying areas needing additional research. Starting from both a well consolidated turbulence model (k-ω SST) and an unstructured grid typology, the main simulation settings are here manipulated in a convenient form to tackle rotating grids reproducing a VAWT operating in an open jet wind tunnel. The dependence of the numerical predictions from the selected grid spacing is investigated, thus establishing the less refined grid size that is still capable of capturing some relevant flow features such as integral quantities (rotor torque) and local ones (wake velocities). (paper)

  8. Reliability of numerical wind tunnels for VAWT simulation

    Science.gov (United States)

    Raciti Castelli, M.; Masi, M.; Battisti, L.; Benini, E.; Brighenti, A.; Dossena, V.; Persico, G.

    2016-09-01

    Computational Fluid Dynamics (CFD) based on the Unsteady Reynolds Averaged Navier Stokes (URANS) equations have long been widely used to study vertical axis wind turbines (VAWTs). Following a comprehensive experimental survey on the wakes downwind of a troposkien-shaped rotor, a campaign of bi-dimensional simulations is presented here, with the aim of assessing its reliability in reproducing the main features of the flow, also identifying areas needing additional research. Starting from both a well consolidated turbulence model (k-ω SST) and an unstructured grid typology, the main simulation settings are here manipulated in a convenient form to tackle rotating grids reproducing a VAWT operating in an open jet wind tunnel. The dependence of the numerical predictions from the selected grid spacing is investigated, thus establishing the less refined grid size that is still capable of capturing some relevant flow features such as integral quantities (rotor torque) and local ones (wake velocities).

  9. The value of service reliability

    OpenAIRE

    Benezech , Vincent; Coulombel , Nicolas

    2013-01-01

    International audience; This paper studies the impact of service frequency and reliability on the choice of departure time and the travel cost of transit users. When the user has (α, β, γ) scheduling preferences, we show that the optimal head start decreases with service reliability, as expected. It does not necessarily decrease with service frequency, however. We derive the value of service headway (VoSH) and the value of service reliability (VoSR), which measure the marginal effect on the e...

  10. Distribution-Independent Reliable Learning

    OpenAIRE

    Kanade, Varun; Thaler, Justin

    2014-01-01

    We study several questions in the reliable agnostic learning framework of Kalai et al. (2009), which captures learning tasks in which one type of error is costlier than others. A positive reliable classifier is one that makes no false positive errors. The goal in the positive reliable agnostic framework is to output a hypothesis with the following properties: (i) its false positive error rate is at most $\\epsilon$, (ii) its false negative error rate is at most $\\epsilon$ more than that of the...

  11. Fatigue is a reliable, sensitive and unique outcome measure in rheumatoid arthritis.

    LENUS (Irish Health Repository)

    Minnock, Patricia

    2009-12-01

    Fatigue is an important symptom in patients with RA. Measurement of fatigue in clinical trials and in clinical practice requires scales that are reproducible, sensitive to change and practical. This study examined the reliability and sensitivity to change of fatigue and its relative independence as an outcome measure in RA.

  12. Test-Retest Reliability of an Experienced Global Trigger Tool Review Team

    DEFF Research Database (Denmark)

    Bjørn, Brian; Anhøj, Jacob; Østergaard, Mette

    2018-01-01

    and review 2 and between period 1 and period 2. The increase was solely in category E, minor temporary harm. CONCLUSIONS: The very experienced GTT team could not reproduce harm rates found in earlier reviews. We conclude that GTT in its present form is not a reliable measure of harm rate over time....

  13. RTE - 2015 Reliability Report. Summary

    International Nuclear Information System (INIS)

    2016-01-01

    Every year, RTE produces a reliability report for the past year. This report includes a number of results from previous years so that year-to-year comparisons can be drawn and long-term trends analysed. The 2015 report underlines the major factors that have impacted on the reliability of the electrical power system, without focusing exclusively on Significant System Events (ESS). It describes various factors which contribute to present and future reliability and the numerous actions implemented by RTE to ensure reliability today and in the future, as well as the ways in which the various parties involved in the electrical power system interact across the whole European interconnected network

  14. How reproducible is self-reported information on exposure to smoking, drinking, and dietary patterns? Evidence among Brazilian adults in the Pró-Saúde Study

    Directory of Open Access Journals (Sweden)

    Dóra Chor

    Full Text Available CONTEXT: Epidemiological studies of the validity and reliability of self-reported information on important risk factors for non-communicable chronic diseases are scarce in Brazil. OBJECTIVE: We evaluated the test-retest reliability of information overall and stratified by gender, age and education on active and passive smoking, alcohol intake and aspects of dietary habits. TYPE OF STUDY: Test-retest reliability. SETTING: Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil. PARTICIPANTS: 192 University employees. PROCEDURES: Self-administered questionnaires were completed on two occasions, two weeks apart. MAIN MEASUREMENTS: Kappa Statistics; Intraclass Correlation Coefficient. RESULTS: Information on smoking status and pack-years smoked had almost perfect levels of agreement, respectively, kappa = 0.97 (95% CI, 0.92-1.00, and intraclass correlation coefficient = 0.93 (CI 95%, 0.89-0.96. Characteristics of alcohol intake yielded substantial levels of agreement (kappa ranging from 0.62 to 0.69. The reproducibility of the information on dietary habits varied from 0.67 to 0.79 (kappa. No clear-cut patterns could be identified comparing information by age or gender. There was a slight tendency towards greater reliability among people with higher levels of education. CONCLUSION: The reproducibility of information on smoking, drinking, and dietary patterns ranged from substantial to excellent, as investigated in the Pró-Saúde Study, a longitudinal investigation recently launched in Rio de Janeiro.

  15. Reproducible simulation of respiratory motion in porcine lung explants

    Energy Technology Data Exchange (ETDEWEB)

    Biederer, J. [Dept. of Diagnostic Radiology, Univ. Hospital Schleswig-Holstein, Campus Kiel (Germany); Dept. of Radiology, German Cancer Research Center, Heidelberg (Germany); Plathow, C. [Dept. of Diagnostic Radiology, Eberhard-Karls-Univ. Tuebingen (Germany); Dept. of Radiology, German Cancer Research Center, Heidelberg (Germany); Schoebinger, M.; Meinzer, H.P. [Dept. of Medical and Biological Informatics, German Cancer Research Center, Heidelberg (Germany); Tetzlaff, R.; Puderbach, M.; Zaporozhan, J.; Kauczor, H.U. [Dept. of Radiology, German Cancer Research Center, Heidelberg (Germany); Bolte, H.; Heller, M. [Dept. of Diagnostic Radiology, Univ. Hospital Schleswig-Holstein, Campus Kiel (Germany)

    2006-11-15

    Purpose: To develop a model for exactly reproducible respiration motion simulations of animal lung explants inside an MR-compatible chest phantom. Materials and Methods: The materials included a piston pump and a flexible silicone reconstruction of a porcine diaphragm and were used in combination with an established MR-compatible chest phantom for porcine heart-lung preparations. The rhythmic inflation and deflation of the diaphragm at the bottom of the artificial thorax with water (1-1.5 L) induced lung tissue displacement resembling diaphragmatic breathing. This system was tested on five porcine heart-lung preparations using 1.5T MRI with transverse and coronal 3D-GRE (TR/TE=3.63/1.58, 256 x 256 matrix, 350 mm FOV, 4 mm slices) and half Fourier T2-FSE (TR/TE=545/29, 256 x 192, 350 mm, 6 mm) as well as multiple row detector CT (16 x 1 mm collimation, pitch 1.5, FOV 400 mm, 120 mAs) acquired at five fixed inspiration levels. Dynamic CT scans and coronal MRI with dynamic 2D-GRE and 2D-SS-GRE sequences (image frequencies of 10/sec and 3/sec, respectively) were acquired during continuous 'breathing' (7/minute). The position of the piston pump was visually correlated with the respiratory motion visible through the transparent wall of the phantom and with dynamic displays of CT and MR images. An elastic body splines analysis of the respiratory motion was performed using CT data. Results: Visual evaluation of MRI and CT showed three-dimensional movement of the lung tissue throughout the respiration cycle. Local tissue displacement inside the lung explants was documented with motion maps calculated from CT. The maximum displacement at the top of the diaphragm (mean 26.26 [SD 1.9] mm on CT and 27.16 [SD 1.5] mm on MRI, respectively [p=0.25; Wilcoxon test]) was in the range of tidal breathing in human patients. Conclusion: The chest phantom with a diaphragmatic pump is a promising platform for multi-modality imaging studies of the effects of respiratory lung

  16. Reproducible simulation of respiratory motion in porcine lung explants

    International Nuclear Information System (INIS)

    Biederer, J.; Plathow, C.; Schoebinger, M.; Meinzer, H.P.; Tetzlaff, R.; Puderbach, M.; Zaporozhan, J.; Kauczor, H.U.; Bolte, H.; Heller, M.

    2006-01-01

    Purpose: To develop a model for exactly reproducible respiration motion simulations of animal lung explants inside an MR-compatible chest phantom. Materials and Methods: The materials included a piston pump and a flexible silicone reconstruction of a porcine diaphragm and were used in combination with an established MR-compatible chest phantom for porcine heart-lung preparations. The rhythmic inflation and deflation of the diaphragm at the bottom of the artificial thorax with water (1-1.5 L) induced lung tissue displacement resembling diaphragmatic breathing. This system was tested on five porcine heart-lung preparations using 1.5T MRI with transverse and coronal 3D-GRE (TR/TE=3.63/1.58, 256 x 256 matrix, 350 mm FOV, 4 mm slices) and half Fourier T2-FSE (TR/TE=545/29, 256 x 192, 350 mm, 6 mm) as well as multiple row detector CT (16 x 1 mm collimation, pitch 1.5, FOV 400 mm, 120 mAs) acquired at five fixed inspiration levels. Dynamic CT scans and coronal MRI with dynamic 2D-GRE and 2D-SS-GRE sequences (image frequencies of 10/sec and 3/sec, respectively) were acquired during continuous 'breathing' (7/minute). The position of the piston pump was visually correlated with the respiratory motion visible through the transparent wall of the phantom and with dynamic displays of CT and MR images. An elastic body splines analysis of the respiratory motion was performed using CT data. Results: Visual evaluation of MRI and CT showed three-dimensional movement of the lung tissue throughout the respiration cycle. Local tissue displacement inside the lung explants was documented with motion maps calculated from CT. The maximum displacement at the top of the diaphragm (mean 26.26 [SD 1.9] mm on CT and 27.16 [SD 1.5] mm on MRI, respectively [p=0.25; Wilcoxon test]) was in the range of tidal breathing in human patients. Conclusion: The chest phantom with a diaphragmatic pump is a promising platform for multi-modality imaging studies of the effects of respiratory lung motion. (orig.)

  17. Evaluation of mammographic density patterns: reproducibility and concordance among scales

    Directory of Open Access Journals (Sweden)

    Garrido-Estepa Macarena

    2010-09-01

    .32% respectively, while this percentage was lower for the quantitative scales (21.89% for BI-RADS and 21.86% for Boyd. Conclusions Visual scales of mammographic density show a high reproducibility when appropriate training is provided. Their ability to distinguish between high and low risk render them useful for routine use by breast cancer screening programs. Quantitative-based scales are more specific than pattern-based scales in classifying populations in the high-risk group.

  18. Assay reproducibility in clinical studies of plasma miRNA.

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    Jonathan Rice

    Full Text Available There are increasing reports of plasma miRNAs as biomarkers of human disease but few standards in methodologic reporting, leading to inconsistent data. We systematically reviewed plasma miRNA studies published between July 2013-June 2014 to assess methodology. Six parameters were investigated: time to plasma extraction, methods of RNA extraction, type of miRNA, quantification, cycle threshold (Ct setting, and methods of statistical analysis. We compared these data with a proposed standard methodologic technique. Beginning with initial screening for 380 miRNAs using microfluidic array technology and validation in an additional cohort of patients, we compared 11 miRNAs that exhibited differential expression between 16 patients with benign colorectal neoplasms (advanced adenomas and 16 patients without any neoplasm (controls. Plasma was isolated immediately, 12, 24, 48, or 72 h following phlebotomy. miRNA was extracted using two different techniques (Trizol LS with pre-amplification or modified miRNeasy. We performed Taqman-based RT-PCR assays for the 11 miRNAs with subsequent analyses using a variable Ct setting or a fixed Ct set at 0.01, 0.03, 0.05, or 0.5. Assays were performed in duplicate by two different operators. RNU6 was the internal reference. Systematic review yielded 74 manuscripts meeting inclusion criteria. One manuscript (1.4% documented all 6 methodological parameters, while < 5% of studies listed Ct setting. In our proposed standard technique, plasma extraction ≤12 h provided consistent ΔCt. miRNeasy extraction yielded higher miRNA concentrations and fewer non-expressed miRNAs compared to Trizol LS (1/704 miRNAs [0.14%] vs 109/704 miRNAs [15%], not expressed, respectively. A fixed Ct bar setting of 0.03 yielded the most reproducible data, provided that <10% miRNA were non-expressed. There was no significant intra-operator variability. There was significant inter-operator variation using Trizol LS extraction, while this was

  19. Experimentally Reproducing Thermal Breakdown of Rock at Earth's Surface

    Science.gov (United States)

    Eppes, M. C.; Griffiths, L.; Heap, M. J.; Keanini, R.; Baud, P.

    2016-12-01

    Thermal stressing induces microcrack growth in rock in part due to thermal expansion mismatch between different minerals, mineral phases, or crystalline axes and/or thermal gradients in the entire rock mass. This knowledge is largely derived from experimental studies of thermal microcracking, typically under conditions of very high temperatures (hundreds of °C). Thermal stressing at lower temperatures has received significantly less attention despite the fact that it may play an important role in rock breakdown at and near Earth's surface (Aldred et al., 2015; Collins and Stock, 2016). In particular, Eppes et al. (2016) attribute recorded Acoustic Emissions (AE) from a highly instrumented granite boulder sitting on the ground in natural conditions to subcritical crack growth driven by thermal stresses arising from a combination of solar- and weather-induced temperature changes; however the maximum temperature the boulder experienced was just 65 °C. In order to better understand these results without complicating factors of a natural environment, we conducted controlled laboratory experiments on cylindrical samples (40 mm length and 20 mm diameter) cored from the same granite as the Eppes et al. (2016) experiment, subjecting them to temperature fluctuations that reproduced the field measurements. We used a novel experimental configuration whereby two high temperature piezo-transducers are each in contact with an opposing face of the sample. The servo-controlled uniaxial press compensates for the thermal expansion and contraction of the pistons and the sample, keeping the coupling between the transducers and the sample, and the axial force acting on the sample, constant throughout. The system records AE, as well as P-wave velocity, both independent proxies for microfracture, as well as strain and temperature. Preliminary tests, heating and cooling granite at a rate of 1 °C/min, show that a large amount of AE occurs at temperatures as low as 100 °C. Ultimately, by

  20. Reproducibility and relative validity of a food frequency questionnaire developed for adults in Taizhou, China.

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    Maoqiang Zhuang

    Full Text Available To evaluate the reproducibility and validity of a food frequency questionnaire (FFQ developed to investigate the relationship between dietary factors and diseases in the adult Chinese population in East China.A total of 78 males and 129 females aged 30-75 years completed four inconsecutive 24-hour dietary recalls (24-HRs, served as a reference method and two FFQs (FFQ1 and FFQ2 over a nine-month interval. The reproducibility of the FFQ was estimated with correlation coefficients, cross-classification, and weighted kappa statistic. The validity was assessed by comparing the data obtained from FFQ and 24-HRs.The median nutrient intakes assessed with FFQs were higher than the average of four 24-HRs. For the food groups, Spearman, Pearson, and intraclass correlation coefficients between FFQ1 and FFQ2 ranged from 0.23 to 0.61, 0.27 to 0.64, and 0.26 to 0.65, respectively. For total energy and nutrient intakes, the corresponding coefficients ranged from 0.25 to 0.61, 0.28 to 0.64, and 0.28 to 0.62, respectively. The correlations between FFQ1 and FFQ2 for most nutrients decreased after adjustment with total energy intake. More than 70% of the subjects were classified into the same and adjacent categories by both FFQs. For food groups, the crude, energy-adjusted, and de-attenuated Spearman correlation coefficients between FFQ2 and the 24-HRs ranged from 0.17 to 0.59, 0.10 to 0.57, and 0.11 to 0.64, respectively. For total energy and nutrient intakes, the corresponding coefficients ranged from 0.20 to 0.58, 0.08 to 0.54, and 0.09 to 0.56, respectively. More than 67% of the subjects were classified into the same and adjacent categories by both instruments. Both weighted kappa statistic and Bland-Altman Plots showed reasonably acceptable agreement between the FFQ2 and 24-HRs.The FFQ developed for adults in the Taizhou area is reasonably reliable and valid for assessment of most food and nutrient intakes.