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Sample records for generalized mantel-haenszel analysis

  1. Relative effectiveness of generalized Mantel-Haenszel ...

    African Journals Online (AJOL)

    The study compared the power of Differential Item Functioning (DIF) detection for ordinal test items among Generalized Mantel Haenszel (GMH), Simultaneous Item Bias Test (SIBTEST), and Logistic Discriminant Function Analysis (LDFA) methods. It also determined the relationship between the proportions of test items that ...

  2. An adaptive Mantel-Haenszel test for sensitivity analysis in observational studies.

    Science.gov (United States)

    Rosenbaum, Paul R; Small, Dylan S

    2017-06-01

    In a sensitivity analysis in an observational study with a binary outcome, is it better to use all of the data or to focus on subgroups that are expected to experience the largest treatment effects? The answer depends on features of the data that may be difficult to anticipate, a trade-off between unknown effect-sizes and known sample sizes. We propose a sensitivity analysis for an adaptive test similar to the Mantel-Haenszel test. The adaptive test performs two highly correlated analyses, one focused analysis using a subgroup, one combined analysis using all of the data, correcting for multiple testing using the joint distribution of the two test statistics. Because the two component tests are highly correlated, this correction for multiple testing is small compared with, for instance, the Bonferroni inequality. The test has the maximum design sensitivity of two component tests. A simulation evaluates the power of a sensitivity analysis using the adaptive test. Two examples are presented. An R package, sensitivity2x2xk, implements the procedure. © 2016, The International Biometric Society.

  3. Type I error and statistical power of the Mantel-Haenszel procedure for detecting DIF: a meta-analysis.

    Science.gov (United States)

    Guilera, Georgina; Gómez-Benito, Juana; Hidalgo, Maria Dolores; Sánchez-Meca, Julio

    2013-12-01

    This article presents a meta-analysis of studies investigating the effectiveness of the Mantel-Haenszel (MH) procedure when used to detect differential item functioning (DIF). Studies were located electronically in the main databases, representing the codification of 3,774 different simulation conditions, 1,865 related to Type I error and 1,909 to statistical power. The homogeneity of effect-size distributions was assessed by the Q statistic. The extremely high heterogeneity in both error rates (I² = 94.70) and power (I² = 99.29), due to the fact that numerous studies test the procedure in extreme conditions, means that the main interest of the results lies in explaining the variability in detection rates. One-way analysis of variance was used to determine the effects of each variable on detection rates, showing that the MH test was more effective when purification procedures were used, when the data fitted the Rasch model, when test contamination was below 20%, and with sample sizes above 500. The results imply a series of recommendations for practitioners who wish to study DIF with the MH test. A limitation, one inherent to all meta-analyses, is that not all the possible moderator variables, or the levels of variables, have been explored. This serves to remind us of certain gaps in the scientific literature (i.e., regarding the direction of DIF or variances in ability distribution) and is an aspect that methodologists should consider in future simulation studies. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  4. Practical approaches for design and analysis of clinical trials of infertility treatments: crossover designs and the Mantel-Haenszel method are recommended.

    Science.gov (United States)

    Takada, Michihiro; Sozu, Takashi; Sato, Tosiya

    2015-01-01

    Crossover designs have some advantages over standard clinical trial designs and they are often used in trials evaluating the efficacy of treatments for infertility. However, clinical trials of infertility treatments violate a fundamental condition of crossover designs, because women who become pregnant in the first treatment period are not treated in the second period. In previous research, to deal with this problem, some new designs, such as re-randomization designs, and analysis methods including the logistic mixture model and the beta-binomial mixture model were proposed. Although the performance of these designs and methods has previously been evaluated in large-scale clinical trials with sample sizes of more than 1000 per group, the actual sample sizes of infertility treatment trials are usually around 100 per group. The most appropriate design and analysis for these moderate-scale clinical trials are currently unclear. In this study, we conducted simulation studies to determine the appropriate design and analysis method of moderate-scale clinical trials for irreversible endpoints by evaluating the statistical power and bias in the treatment effect estimates. The Mantel-Haenszel method had similar power and bias to the logistic mixture model. The crossover designs had the highest power and the smallest bias. We recommend using a combination of the crossover design and the Mantel-Haenszel method for two-period, two-treatment clinical trials with irreversible endpoints. Copyright © 2015 John Wiley & Sons, Ltd.

  5. An Investigation of the Efficacy of Criterion Refinement Procedures in Mantel-Haenszel DIF Analysis. Research Report. ETS RR-13-16

    Science.gov (United States)

    Zwick, Rebecca; Ye, Lei; Isham, Steven

    2013-01-01

    Differential item functioning (DIF) analysis is a key component in the evaluation of the fairness and validity of educational tests. Although it is often assumed that refinement of the matching criterion always provides more accurate DIF results, the actual situation proves to be more complex. To explore the effectiveness of refinement, we…

  6. Comparison of Three Software Programs for Evaluating DIF by Means of the Mantel-Haenszel Procedure: EASY-DIF, DIFAS and EZDIF

    Science.gov (United States)

    Padilla, Jose Luis; Hidalgo, M. Dolores; Benitez, Isabel; Gomez-Benito, Juana

    2012-01-01

    The analysis of differential item functioning (DIF) examines whether item responses differ according to characteristics such as language and ethnicity, when people with matching ability levels respond differently to the items. This analysis can be performed by calculating various statistics, one of the most important being the Mantel-Haenszel,…

  7. The Effects of Score Group Width on the Mantel-Haenszel Procedure.

    Science.gov (United States)

    Clauser, Brian; And Others

    Previous research examining the effects of reducing the number of score groups used in the matching criterion of the Mantel-Haenszel procedure, when screening for differential item functioning, has produced ambiguous results. The goal of this study was to resolve the ambiguity by examining the problem with a simulated data set. The main results…

  8. Type I Error Inflation in DIF Identification with Mantel-Haenszel: An Explanation and a Solution

    Science.gov (United States)

    Magis, David; De Boeck, Paul

    2014-01-01

    It is known that sum score-based methods for the identification of differential item functioning (DIF), such as the Mantel-Haenszel (MH) approach, can be affected by Type I error inflation in the absence of any DIF effect. This may happen when the items differ in discrimination and when there is item impact. On the other hand, outlier DIF methods…

  9. The Mantel-Haenszel Method for Detecting Differential Item Functioning in Dichotomously Scored Items: A Multilevel Approach

    Science.gov (United States)

    MacInnes, Jann Marie Wise

    2009-01-01

    Multilevel data often exist in educational studies. The focus of this study is to consider differential item functioning (DIF) for dichotomous items from a multilevel perspective. One of the most often used methods for detecting DIF in dichotomously scored items is the Mantel-Haenszel log odds-ratio. However, the Mantel-Haenszel reduces the…

  10. Sensitivity of Mantel Haenszel Model and Rasch Model as Viewed From Sample Size

    OpenAIRE

    ALWI, IDRUS

    2011-01-01

    The aims of this research is to study the sensitivity comparison of Mantel Haenszel and Rasch Model for detection differential item functioning, observed from the sample size. These two differential item functioning (DIF) methods were compared using simulate binary item respon data sets of varying sample size,  200 and 400 examinees were used in the analyses, a detection method of differential item functioning (DIF) based on gender difference. These test conditions were replication 4 tim...

  11. A Formulation of the Mantel-Haenszel Differential Item Functioning Parameter with Practical Implications. Statistical Report. LSAC Research Report Series.

    Science.gov (United States)

    Roussos, Louis A.; Schnipke, Deborah L.; Pashley, Peter J.

    The Mantel-Haenszel (MH) differential item functioning (DIF) parameter for uniform DIF is well defined when item responses follow the two-parameter-logistic (2PPL) item response function (IRF), but not when they follow the three-parameter-logistic (3PL) IRF, the model typically used with multiple choice items. This research report presents a…

  12. Assessing DIF among small samples with separate calibration t and Mantel-Haenszel χ² statistics in the Rasch model.

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    Bernstein, Ira; Samuels, Ellery; Woo, Ada; Hagge, Sarah L

    2013-01-01

    The National Council Licensure Examination (NCLEX) program has evaluated differential item functioning (DIF) using the Mantel-Haenszel (M-H) chi-square statistic. Since a Rasch model is assumed, DIF implies a difference in item difficulty between a reference group, e.g., White applicants, and a focal group, e.g., African-American applicants. The National Council of State Boards of Nursing (NCSBN) is planning to change the statistic used to evaluate DIF on the NCLEX from M-H to the separate calibration t-test (t). In actuality, M-H and t should yield identical results in large samples if the assumptions of the Rasch model hold (Linacre and Wright, 1989, also see Smith, 1996). However, as is true throughout statistics, "how large is large" is undefined, so it is quite possible that systematic differences exist in relatively smaller samples. This paper compares M-H and t in four sets of computer simulations. Three simulations used a ten-item test with nine fair items and one potentially containing DIF. To address instability that may result from a ten-item test, the fourth used a 30-item test with 29 fair items and one potentially containing DIF. Depending upon the simulation, the magnitude of population DIF (0, .5, 1.0, and 1.5 z-score units), the ability difference between the focal and reference group (-1, 0, and 1 z-score units), the focal group size (0, 10, 20, 40, 50, 80, 160, and 1000), and the reference group size (500 and 1000) were varied. The results were that: (a) differences in estimated DIF between the M-H and t statistics are generally small, (b) t tends to estimate lower chance probabilities than M-H with small sample sizes, (c) neither method is likely to detect DIF, especially when it is of slight magnitude in small focal group sizes, and (d) M-H does marginally better than t at detecting DIF but this improvement is also limited to very small focal group sizes.

  13. Nonparametric analysis of blocked ordered categories data: some examples revisited

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    O. Thas

    2006-08-01

    Full Text Available Nonparametric analysis for general block designs can be given by using the Cochran-Mantel-Haenszel (CMH statistics. We demonstrate this with four examples and note that several well-known nonparametric statistics are special cases of CMH statistics.

  14. Alternative Matching Scores to Control Type I Error of the Mantel-Haenszel Procedure for DIF in Dichotomously Scored Items Conforming to 3PL IRT and Nonparametric 4PBCB Models

    Science.gov (United States)

    Monahan, Patrick O.; Ankenmann, Robert D.

    2010-01-01

    When the matching score is either less than perfectly reliable or not a sufficient statistic for determining latent proficiency in data conforming to item response theory (IRT) models, Type I error (TIE) inflation may occur for the Mantel-Haenszel (MH) procedure or any differential item functioning (DIF) procedure that matches on summed-item…

  15. Impact of Missing Data on the Detection of Differential Item Functioning: The Case of Mantel-Haenszel and Logistic Regression Analysis

    Science.gov (United States)

    Robitzsch, Alexander; Rupp, Andre A.

    2009-01-01

    This article describes the results of a simulation study to investigate the impact of missing data on the detection of differential item functioning (DIF). Specifically, it investigates how four methods for dealing with missing data (listwise deletion, zero imputation, two-way imputation, response function imputation) interact with two methods of…

  16. National trends in minimally invasive and open operative experience of graduating general surgery residents: implications for surgical skills curricula development?

    Science.gov (United States)

    Carson, Jeffrey S; Smith, Lynette; Are, Madhuri; Edney, James; Azarow, Kenneth; Mercer, David W; Thompson, Jon S; Are, Chandrakanth

    2011-12-01

    The aim of this study was to analyze national trends in minimally invasive and open cases of all graduating residents in general surgery. A retrospective analysis was performed on data obtained from Accreditation Council for Graduate Medical Education logs (1999-2008) of graduating residents from all US general surgery residency programs. Data were analyzed using Mantel-Haenszel χ(2) tests and the Bonferroni adjustment to detect trends in the number of minimally invasive and open cases. Minimally invasive procedures accounted for an increasing proportion of cases performed (3.7% to 11.1%, P surgery (P general surgery residents in the United States are performing a greater number of minimally invasive and fewer open procedures for common surgical conditions. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Sensitivity and attachment interventions in early childhood: A systematic review and meta-analysis.

    Science.gov (United States)

    Mountain, Gary; Cahill, Jane; Thorpe, Helen

    2017-02-01

    A systematic review and meta-analysis of randomized controlled trials (RCT) was conducted to determine whether early interventions are effective in improving attachment security and parental sensitivity. Electronic databases were searched 2002-2015 onwards, All RCTs delivered to mothers, fathers or carers, before their child's mean age was 36 months, via 1:1 support, group work or guided self-help were included. The search was restricted to English Language publications. Study Selection, data extraction and quality appraisal were independently undertaken by two authors. With regard to analysis, where appropriate, dichotomous data were pooled using the Mantel- Haenszel odds ratio method and for continuous data descriptive statistics were collected in order to calculate standardized mean differences and effect sizes. Four studies met inclusion criteria and were divided into two groups: North American & Canadian and South African based studies. Combining data from both groups indicates that early interventions improve attachment security and improves rates of disorganized attachment. One study provided extractable data on the outcome of parental sensitivity which shows that early interventions were effective in improving maternal sensitivity at 6 and 12 months. Study results generally support the findings of a previous review (Bakermans-Kranenburg et al., 2003) which found that early interventions improved attachment security and maternal sensitivity. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Evaluating the cross-cultural validity of the Polish version of the Four-Dimensional Symptom Questionnaire (4DSQ) using differential item functioning (DIF) analysis.

    Science.gov (United States)

    Czachowski, Sławomir; Terluin, Berend; Izdebski, Adam; Izdebski, Paweł

    2012-10-01

    The original Dutch Four-Dimensional Symptom Questionnaire (4DSQ), which measures distress, depression, anxiety and somatization, has been translated into Polish with the aim of providing primary health care with a good screening instrument for the detection of the most prevalent mental health problems (anxiety, somatization, depression and distress). To check if the Polish version is cross-culturally valid so that the scores of Polish subjects can be compared with the scores of Dutch subjects and the Dutch cut-off points can be used in Polish subjects. 4DSQ data were collected from a mixed sample of students and primary care attendees. The Polish data were compared with the 4DSQ data of a matched sample of Dutch students and primary care attendees. Two methods of differential item functioning (DIF) analysis, ordinal logistic regression and generalized Mantel-Haenszel, were used to detect items with DIF, and linear regression analysis was used to estimate the scale-level impact of DIF. Four items showing DIF were detected in the distress scale, one in the somatization scale and one in the anxiety scale. The DIF in distress caused Polish subjects with moderate scores to score circa 1 point less than their Dutch counterparts. The results of the DIF analyses suggest that the Polish 4DSQ measures the same constructs as the Dutch 4DSQ and that the Dutch norms can be used for the Polish subjects, except for distress: the first cut-off point should be one point lower.

  19. Efficacy of aprepitant for prevention of postoperative nausea and vomiting. Systematic review and meta-analysis of randomized clinical trials

    Directory of Open Access Journals (Sweden)

    Berrío Valencia, Marta Inés

    2014-10-01

    Full Text Available Objective: To evaluate the efficacy of aprepitant compared with other antiemetics for the prevention of postoperative nausea and vomiting in adults who underwent general anesthesia. Methods: Systematic review of randomized clinical trials with meta-analysis, that evaluated the efficacy of aprepitant in comparatison with other antiemetics for the prevention of postoperative nausea and vomiting, antiemetic rescue and adverse effects. The search was done in The Cochrane Library, EBSCO, EMBASE, LILACS, OVID, PubMed, SciELO, ScienceDirect, Scopus and Google Scholar. Heterogeneity was defined with the Cochran Q and I2 statistic, the model fixed and random effects were used, the Mantel-Haenszel for relative risk of each outcome and its respective confidence interval 95% were used. Results: There was significant difference in favor of aprepitant for the prevention of vomiting at 24 (RR 0.52; 95% CI: 0.38-0.7 and at 48 hours (RR 0.51; 95% CI: 0.39 to 0.67 but not for nausea at 24 hours (RR 1.16; 95% CI: 0.85-1.6. Conclusions: Aprepitant prevents postoperative vomiting, but not nausea, at 24 and 48 hours.

  20. Beta-binomial model for meta-analysis of odds ratios.

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    Bakbergenuly, Ilyas; Kulinskaya, Elena

    2017-05-20

    In meta-analysis of odds ratios (ORs), heterogeneity between the studies is usually modelled via the additive random effects model (REM). An alternative, multiplicative REM for ORs uses overdispersion. The multiplicative factor in this overdispersion model (ODM) can be interpreted as an intra-class correlation (ICC) parameter. This model naturally arises when the probabilities of an event in one or both arms of a comparative study are themselves beta-distributed, resulting in beta-binomial distributions. We propose two new estimators of the ICC for meta-analysis in this setting. One is based on the inverted Breslow-Day test, and the other on the improved gamma approximation by Kulinskaya and Dollinger (2015, p. 26) to the distribution of Cochran's Q. The performance of these and several other estimators of ICC on bias and coverage is studied by simulation. Additionally, the Mantel-Haenszel approach to estimation of ORs is extended to the beta-binomial model, and we study performance of various ICC estimators when used in the Mantel-Haenszel or the inverse-variance method to combine ORs in meta-analysis. The results of the simulations show that the improved gamma-based estimator of ICC is superior for small sample sizes, and the Breslow-Day-based estimator is the best for n⩾100. The Mantel-Haenszel-based estimator of OR is very biased and is not recommended. The inverse-variance approach is also somewhat biased for ORs≠1, but this bias is not very large in practical settings. Developed methods and R programs, provided in the Web Appendix, make the beta-binomial model a feasible alternative to the standard REM for meta-analysis of ORs. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

  1. Cranberry Reduces the Risk of Urinary Tract Infection Recurrence in Otherwise Healthy Women: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Fu, Zhuxuan; Liska, DeAnn; Talan, David; Chung, Mei

    2017-12-01

    Background: Cranberry ( Vaccinium spp.) has been advocated for treatment of urinary tract infection (UTI); however, its efficacy is controversial. Women have a 50% risk of UTI over their lifetime, and ∼20-30% experience a subsequent UTI recurrence. Objective: We conducted this meta-analysis to assess the effect of cranberry on the risk of UTI recurrence in otherwise healthy women. Methods: Literature published before January 2011 was obtained from 2 published systematic reviews, and we conducted updated searches in EMBASE and MEDLINE (through July 2017). We included randomized controlled trials that were conducted in generally healthy nonpregnant women aged ≥18 y with a history of UTI, compared cranberry intervention to a placebo or control, and reported the outcome as the number of participants experiencing a UTI. Two researchers conducted abstract and full-text screenings, data extractions, and risk of bias assessments independently, and discrepancies were resolved by group consensus. Meta-analyses were performed by using Stata SE software (version 13). We employed a fixed-effect model using the Mantel-Haenszel method to estimate the summary risk if the heterogeneity was low to moderate ( I 2 cranberry reduced the risk of UTI by 26% (pooled risk ratio: 0.74; 95% CI: 0.55, 0.98; I 2 = 54%). Risk of bias indicated that 2 studies had high loss to follow-up or selective outcome reporting. Overall, the studies were relatively small, with only 2 having >300 participants. Conclusion: These results suggest that cranberry may be effective in preventing UTI recurrence in generally healthy women; however, larger high-quality studies are needed to confirm these findings. This trial was registered at crd.york.ac.uk/prospero as CRD42015024439. © 2017 American Society for Nutrition.

  2. Oral contraceptive use as a risk factor for premenopausal breast cancer: a meta-analysis.

    Science.gov (United States)

    Kahlenborn, Chris; Modugno, Francesmary; Potter, Douglas M; Severs, Walter B

    2006-10-01

    To perform a meta-analysis of case-control studies that addressed whether prior oral contraceptive (OC) use is associated with premenopausal breast cancer. We searched the MEDLINE and PubMed databases and bibliography reviews to identify case-control studies of OCs and premenopausal breast cancer published in or after 1980. Search terms used included breast neoplasms, oral contraceptives, contraceptive agents, and case-control studies. Studies reported in all languages were included. Thirty-four studies were identified that met inclusion criteria. Two reviewers extracted data from original research articles or additional data provided by study authors. We used the DerSimonian-Laird method to compute pooled odds ratios (ORs) and confidence intervals (CIs) and the Mantel-Haenszel test to assess association between OC use and cancer. Use of OCs was associated with an increased risk of premenopausal breast cancer in general (OR, 1.19; 95% CI, 1.09-1.29) and across various patterns of OC use. Among studies that provided data on nulliparous and parous women separately, OC use was associated with breast cancer risk in both parous (OR, 1.29; 95% CI, 1.20-1.40) and nulliparous (OR, 1.24; 95% CI, 0.92-1.67) women. Longer duration of use did not substantially alter risk in nulliparous women (OR, 1.29; 95% CI, 0.85-1.96). Among parous women, the association was stronger when OCs were used before first full-term pregnancy (FFTP) (OR, 1.44; 95% CI, 1.28-1.62) than after FFTP (OR, 1.15; 95% CI, 1.06-1.26). The association between OC use and breast cancer risk was greatest for parous women who used OCs 4 or more years before FFTP (OR, 1.52; 95% CI, 1.26-1.82). Use of OCs is associated with an increased risk of premenopausal breast cancer, especially with use before FFTP in parous women.

  3. A systematic review and meta-analysis to compare the efficacy of acyclovir 3% ophthalmic ointment to idoxuridine in curing herpetic keratitis by Day 7 of treatment.

    Science.gov (United States)

    Balderson, Diane E; Cai, Gengqian; Fries, Michael A; Kleinman, David M; McLaughlin, Megan M; Trivedi, Trupti M; Wurzelmann, John I; Young, Sheila B

    2015-04-17

    This objective of the review and analysis is to demonstrate that acyclovir (ACV) 3% ophthalmic ointment is superior to idoxuridine (IDU) in treating herpetic keratitis (HK) presenting as dendritic and geographic ulcer sub-types. Publications in human subjects were identified by searching the Ovid MEDLINE database through April 2011, combining medical subject headings (MESH) "Keratitis, Herpetic/" AND "Acyclovir/" limiting by the key words "topical" OR "ointment" and also restricted to MESH "Administration, Topical/" OR "Ointments/". The results were cross checked with the references used in the Cochrane Database Syst Rev. 1:1-134, 2009 and GlaxoSmithKline clinical documents related to acyclovir. Randomized, double-masked studies in subjects diagnosed with HK with head to head comparator arms of ACV ophthalmic ointment and topical IDU that had actual or calculable healing rates at Day seven. Data independently extracted from identified articles by two authors of this manuscript. Data from seven randomized, controlled trials (RCT) evaluating 432 subjects that met inclusion criteria (214 were treated with ACV and 218 were treated with IDU) and had Day seven healing rates calculable. All sub-classified lesions were identified as either dendritic ulcers (n = 185) or geographic ulcers (n = 35). The Cochran-Mantel-Haenszel (CMH) method in Biometrics 10:417-51, 1954 and JNCI 22:719-48, 1959, controlling for study, was performed as the primary analysis using SAS v9. Homogeneity was assessed using Breslow-Day-Tarone (BDT) test in IARC 1:1-32, 1980 and Biometrika 72:91-5, 1985. The analysis was performed with outliers removed to assess their impact. ACV showed statistically significant greater odds of healing HK at Day seven in all subjects (Odds Ratio 3.95, 95% CI2.60, 6.00, p p p = 0.0244). ACV 3% ophthalmic ointment is a valuable intervention for dendritic and geographic corneal ulcers. ACV and IDU were generally well tolerated in the studies reviewed.

  4. Effects of Exercise on Mild-to-Moderate Depressive Symptoms in the Postpartum Period: A Meta-analysis.

    Science.gov (United States)

    McCurdy, Ashley P; Boulé, Normand G; Sivak, Allison; Davenport, Margie H

    2017-06-01

    To examine the influence of exercise on depressive symptoms and the prevalence of depression in the postpartum period. A structured search of MEDLINE, EMBASE, CINAHL, Sport Discus, Ovid's All EBM Reviews, and ClinicalTrials.gov databases was performed with dates from the beginning of the databases until June 16, 2016. The search combined keywords and MeSH-like terms including, but not limited to, "exercise," "postpartum," "depression," and "randomized controlled trial." Randomized controlled trials comparing postpartum exercise (structured, planned, repetitive physical activity) with the standard care for which outcomes assessing depressive symptoms or depressive episodes (as defined by trial authors) were assessed. Trials were identified as prevention trials (women from the general postpartum population) or treatment trials (women were classified as having depression by the trial authors). Effect sizes with 95% confidence intervals (CIs) were calculated using Hedges' g method and standardized mean differences in postintervention depression outcomes were pooled using a random-effects model. Across all 16 trials (1,327 women), the pooled standardized mean difference was -0.34 (95% CI -0.50 to -0.19, I=37%), suggesting a small effect of exercise among all postpartum women on depressive symptoms. Among the 10 treatment trials, a moderate effect size of exercise on depressive symptoms was found (standardized mean difference-0.48, 95% CI -0.73 to -0.22, I=42%). In six prevention trials, a small effect (standardized mean difference-0.22, 95% CI -0.36 to -0.08, I=2%) was found. In women with depression preintervention, exercise increased the odds of resolving depression postintervention by 54% (odds ratio 0.46, Mantel-Haenszel method, 95% CI 0.25-0.84, I=0%). The trials included in this meta-analysis were small and some had methodologic limitations. Light-to-moderate intensity aerobic exercise improves mild-to-moderate depressive symptoms and increases the likelihood that

  5. Is intravenous lorazepam really more effective and safe than intravenous diazepam as first-line treatment for convulsive status epilepticus? A systematic review with meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Brigo, Francesco; Bragazzi, Nicola Luigi; Bacigaluppi, Susanna; Nardone, Raffaele; Trinka, Eugen

    2016-11-01

    Some guidelines or expert consensus indicate that intravenous (IV) lorazepam (LZP) is preferable to IV diazepam (DZP) for initial treatment of convulsive status epilepticus (SE). We aimed to critically assess all the available data on efficacy and tolerability of IV LZP compared with IV DZP as first-line treatment of convulsive SE. Systematic search of the literature (MEDLINE, CENTRAL, EMBASE, ClinicalTrials.gov) to identify randomized controlled trials (RCTs) comparing IV LZP versus IV DZP used as first-line treatment for convulsive SE (generalized or focal). Inverse variance, Mantel-Haenszel meta-analysis to obtain risk ratio (RR) with 95% confidence intervals (CI) of following outcomes: seizure cessation after drug administration; continuation of SE requiring a different drug; seizure cessation after a single dose of medication; need for ventilator support; clinically relevant hypotension. Five RCTs were included, with a total of 656 patients, 320 randomly allocated to IV LZP and 336 to IV DZP. No statistically significant differences were found between IV LZP and IV DZP for clinical seizure cessation (RR 1.09; 95% CI 1.00 to 1.20), continuation of SE requiring a different drug (RR 0.76; 95% CI 0.57 to 1.02), seizure cessation after a single dose of medication (RR 0.96; 95% CI 0.85 to 1.08), need for ventilator support RR 0.93; 95% CI 0.61 to 1.43, and clinically relevant hypotension. Despite its favorable pharmacokinetic profile, a systematic appraisal of the literature does not provide evidence to strongly support the preferential use of IV LZP as first-line treatment of convulsive SE over IV DZP. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Strategies to Improve Child Immunization via Antenatal Care Visits in India: A Propensity Score Matching Analysis.

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    Priyanka Dixit

    Full Text Available Numerous studies have examined the empirical evidence concerning the influence of demographic and socio-economic factors influencing child immunization, but no documentation is available which shows the actual impact of antenatal care (ANC visits on subsequent child immunization. Therefore, this paper aims to examine the net impact of ANC visits on subsequent utilization of child immunization after removing the presence of selection bias. Nationwide data from India's latest National Family Health Survey conducted during 2005-06 is used for the present study. The analysis has been carried out in the two separate models, in the first model 1-2 ANC visit and in the second model three or more ANC visits has been compared with no visit. We have used propensity score matching method with a counterfactual model that assesses the actual ANC visits effect on treated (ANC visits and untreated groups (no ANC visit, and have employed Mantel-Haenszel bounds to examine whether result would be free from hidden bias or not. Using matched sample analysis result shows that child immunization among the groups of women who have completed 1-2 ANC visits and those who had more than two visits was about 13 percent and 19 percent respectively, higher than the group of women who have not made any ANC visit. Findings of nearest neighbor matching with replacement method, which completely eliminated the bias, indicate that selection bias present in data set leads to overestimates the positive effects of ANC visits on child immunization. Result based on Mantel-Haenszel bounds method suggest that if around 19 percent bias would be involved in the result then also we could observe the true positive effect of 1-2 ANC visits on child immunization. This also indicates that antenatal clinics are the conventional platforms for educating pregnant women on the benefits of child immunization.

  7. Does Preputial Reconstruction Increase Complication Rate Of Hypospadias Repair? 20-Year Systematic Review And Meta-analysis

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    Marco eCastagnetti

    2016-04-01

    Full Text Available Introduction: We performed a systematic review of the literature on preputial reconstruction (PR during hypospadias repair to determine the cumulative risk of preputial skin complications and the influence of PR on urethroplasty complications, namely fistula formation and overall reoperation rate of the repair.Material and Methods: A systematic search of the literature published after 06/1995 was performed in 06/2015 using the keyword hypospadias. Only studies on the outcome of PR in children, defined as dehiscence of the reconstructed prepuce or secondary phimosis needing circumcision, were selected. A meta-analysis of studies comparing PR vs. circumcision was performed for the outcomes hypospadias fistula formation and reoperation rate.Results: Twenty studies were identified. Nineteen reported the outcome of PR in 2115 patients. Overall, 95% (2016/2115 of patients undergoing PR had distal hypospadias. The cumulative rate of PR complications was 7.7% (163/2115 patients, including 5.7% (121/2115 patients preputial dehiscences and 1.5% (35/2117 reported patients secondary phimoses needing circumcision. A meta-analysis of 7 studies comparing patients undergoing PR vs. circumcision, showed no increased risk of urethral fistula formation associated with PR, Odds Ratio (Mantel-Haenszel, Fixed effect, 95% CI, 1.25 (0.80-1.97. Likewise, two studies comparing the overall reoperation rate did not show an increased risk of reoperation associated with PR, Odds Ratio (Mantel-Haenszel, Random effect, 95% CI, 1.27 (0.45-3.58. Conclusions: Preputial reconstruction carries an 8% risk of specific complications (dehiscence of reconstructed prepuce or secondary phimosis needing circumcision, but does not seem to increase the risk of urethroplasty complications, and the overall reoperation rate of hypospadias repair.

  8. Adjusting for multiple prognostic factors in the analysis of randomised trials

    Science.gov (United States)

    2013-01-01

    Background When multiple prognostic factors are adjusted for in the analysis of a randomised trial, it is unclear (1) whether it is necessary to account for each of the strata, formed by all combinations of the prognostic factors (stratified analysis), when randomisation has been balanced within each stratum (stratified randomisation), or whether adjusting for the main effects alone will suffice, and (2) the best method of adjustment in terms of type I error rate and power, irrespective of the randomisation method. Methods We used simulation to (1) determine if a stratified analysis is necessary after stratified randomisation, and (2) to compare different methods of adjustment in terms of power and type I error rate. We considered the following methods of analysis: adjusting for covariates in a regression model, adjusting for each stratum using either fixed or random effects, and Mantel-Haenszel or a stratified Cox model depending on outcome. Results Stratified analysis is required after stratified randomisation to maintain correct type I error rates when (a) there are strong interactions between prognostic factors, and (b) there are approximately equal number of patients in each stratum. However, simulations based on real trial data found that type I error rates were unaffected by the method of analysis (stratified vs unstratified), indicating these conditions were not met in real datasets. Comparison of different analysis methods found that with small sample sizes and a binary or time-to-event outcome, most analysis methods lead to either inflated type I error rates or a reduction in power; the lone exception was a stratified analysis using random effects for strata, which gave nominal type I error rates and adequate power. Conclusions It is unlikely that a stratified analysis is necessary after stratified randomisation except in extreme scenarios. Therefore, the method of analysis (accounting for the strata, or adjusting only for the covariates) will not

  9. [Contrast-induced nephropathy in patients at risk of renal failure undergoing computed tomography: systematic review and meta-analysis of randomized controlled trials].

    Science.gov (United States)

    Arana, Estanislao; Catalá-López, Ferrán

    2010-09-11

    We evaluated and quantified by meta-analysis techniques the incidence of contrast-induced nephropathy (CIN) in patients at risk undergoing computed tomography (CT). We conducted a systematic review of randomized controlled clinical trials designated to evaluate the nephrotoxicity related to iso-osmolar contrast media (IOCM) compared to low-osmolar contrast media (LOCM). Main electronic databases searched included PubMed/MEDLINE, EMBASE, ISI Web of Knowledge and Virtual Health Library (BVS-BIREME), as well as abstracts presented at related scientific societies meetings. Prior to data extraction, definitions of nephrotoxicity and risk population were established. Besides meta-analysis, the global agreement between CIN definitions was evaluated with Mantel-Haenszel stratified test. Five studies were included with 716 randomized patients. When CIN was defined as increased serum creatinine (SCr)>or=25%, the relative risk (RR) was 0.71 (CI95%: 0.40-1.26)-in favor of IOCM-and when it was defined as SCr>or=0.5mg/dL it showed a RR 1.48 (CI95%: 0.37-5.87)-favoring LOCM-in the four studies used this criterion. Mantel-Haenszel stratified test was chi2=2.51 (p=0.8). In patients with renal failure undergoing CT there is a similar risk of CIN with the administration of any contrast media studied. CIN incidence depends on the chosen criteria and is lower with the definition of SCr>or=0.5mg/dL at 24-72h. No agreement was found between CIN definitions were adopted. Copyright © 2009 Elsevier España, S.L. All rights reserved.

  10. Effectiveness of dexmedetomidine use in general anesthesia to prevent postoperative shivering: a systematic review.

    Science.gov (United States)

    Hoffman, Jeffrey; Hamner, Casi

    2016-01-15

    standardized data extraction tool from Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument. The data extracted included specific details about the interventions, populations, study methods and outcomes of significance to the review question and specific objectives. Quantitative data was pooled in statistical meta-analysis using Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument. All results were subject to double data entry. Effect sizes were expressed as odds ratio and the 95% confidence intervals were calculated for analysis. Heterogeneity was assessed statistically using the standard Chi-square test. This review included eight randomized controlled trials with 625 participants. The results of the meta-analysis revealed a statistically significant decrease in postanesthetic shivering for the dexmedetomidine group. The Mantel-Haenszel overall relative risk ratio was 0.27 in favor of the dexmedetomidine group [relative risk 0.27, at 95% confidence interval 0.19, 0.36, P shivering in patients undergoing general anesthesia. The Joanna Briggs Institute.

  11. Blinding in randomized controlled trials in general and abdominal surgery: protocol for a systematic review and empirical study.

    Science.gov (United States)

    Probst, Pascal; Grummich, Kathrin; Heger, Patrick; Zaschke, Steffen; Knebel, Phillip; Ulrich, Alexis; Büchler, Markus W; Diener, Markus K

    2016-03-24

    Blinding is a measure in randomized controlled trials (RCT) to reduce detection and performance bias. There is evidence that lack of blinding leads to overestimated treatment effects. Because of the physical component of interventions, blinding is not easily applicable in surgical trials. This is a protocol for a systematic review and empirical study about actual impact on outcomes and future potential of blinding in general and abdominal surgery RCT. A systematic literature search in CENTRAL, MEDLINE and Web of Science will be conducted to locate RCT between 1996 and 2015 with a surgical intervention. General study characteristics and information on blinding methods will be extracted. The risk of performance and detection bias will be rated as low, unclear or high according to the Cochrane Collaboration's tool for assessing risk of bias. The main outcome of interest will be the association of a high risk of performance or detection bias with significant trial results and will be tested at a level of significance of 5 %. Further, trials will be meta-analysed in a Mantel-Haenszel model comparing trials with high risk of bias to other trials at a level of significance of 5 %. Detection and performance bias distort treatment effects. The degree of such bias in general and abdominal surgery is unknown. Evidence on influence of missing blinding would improve critical appraisal and conduct of general and abdominal surgery RCT. PROSPERO 2015: CRD42015026837.

  12. Effect of socioeconomic level on knowledge of stroke in the general population: A social inequality gradient.

    Science.gov (United States)

    Ramírez-Moreno, J M; Alonso-González, R; Peral Pacheco, D; Millán-Nuñez, M V; Roa-Montero, A; Constantino-Silva, A B; Aguirre-Sánchez, J J

    2016-01-01

    Socioeconomic status is a factor that influences health-related behaviour in individuals as well as health conditions in entire populations. The objective of the present study was to analyse the sociodemographic factors that may influence knowledge of stroke. Cross-sectional study. A representative sample was selected by double randomisation. Face-to-face interviews were carried out by previously trained medical students using a structured questionnaire with open- and closed-ended questions. Adequate knowledge was previously defined. The Mantel-Haenszel test and adjusted logistic regression analysis were used to assess the association between knowledge of stroke and the study variables. 2411 subjects were interviewed (59.9% women; mean age 49.0 [SD 17.3] years) Seventy-three per cent were residents of urban areas, 24.7% had a university education, and 15.2% had a low level of schooling. Only 2.1% reported earning more than 40 000 euros/year, with 29.9% earning less than 10 000. Nearly 74% reported having an excellent or good state of health. The unemployment rate was 17.0%. Prevalence of "adequate knowledge" was 39.7% (95% CI: 37.7%-41.6%). Trend analysis showed an association between knowledge of stroke and income (z=10.14, Psocial strata in particular. Copyright © 2014 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

  13. Generalized Linear Covariance Analysis

    Science.gov (United States)

    Carpenter, James R.; Markley, F. Landis

    2014-01-01

    This talk presents a comprehensive approach to filter modeling for generalized covariance analysis of both batch least-squares and sequential estimators. We review and extend in two directions the results of prior work that allowed for partitioning of the state space into solve-for'' and consider'' parameters, accounted for differences between the formal values and the true values of the measurement noise, process noise, and textita priori solve-for and consider covariances, and explicitly partitioned the errors into subspaces containing only the influence of the measurement noise, process noise, and solve-for and consider covariances. In this work, we explicitly add sensitivity analysis to this prior work, and relax an implicit assumption that the batch estimator's epoch time occurs prior to the definitive span. We also apply the method to an integrated orbit and attitude problem, in which gyro and accelerometer errors, though not estimated, influence the orbit determination performance. We illustrate our results using two graphical presentations, which we call the variance sandpile'' and the sensitivity mosaic,'' and we compare the linear covariance results to confidence intervals associated with ensemble statistics from a Monte Carlo analysis.

  14. Alpha-2 adrenergic agonists for the prevention of shivering following general anaesthesia.

    Science.gov (United States)

    Lewis, Sharon R; Nicholson, Amanda; Smith, Andrew F; Alderson, Phil

    2015-08-10

    preoperatively and seven started at varying points from anaesthetic induction to the end of surgery. Whilst all the studies were described as randomized, many provided insufficient detail on methods used. We had anticipated that attempts would be made to reduce performance bias by blinding of personnel and participants, however this was detailed in only six of the papers. Similarly, in some studies detail was lacking on methods to reduce the risk of detection bias. We therefore downgraded the quality of evidence in our 'Summary of findings' table by one level for risk of bias using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.All 20 included studies presented outcome data for postoperative shivering, and in meta-analysis α-2 agonists were shown to significantly reduce the risk of shivering (Mantel-Haenszel risk ratio 0.28, 95% confidence interval 0.18 to 0.43, P value shivering as very low. Only one study reported the incidence of core hypothermia, whilst 12 studies measured core temperature. However, as the results for core temperature were reported in different styles, pooling the results was inappropriate. We found no studies with participant-reported outcomes such as experience of shivering or participant satisfaction. We found limited data for the outcomes of length of stay in the postanaesthetic care unit (three studies, 200 participants) and the following adverse effects: sedation (nine studies, 875 participants), bradycardia (eight studies, 716 participants), and hypotension (seven studies, 688 participants). Unpooled analysis suggested that sedation and bradycardia were significantly more common with dexmedetomidine than placebo, with all seven dexmedetomidine studies and none of the clonidine studies reporting statistically significantly higher levels of sedation as an adverse effect. There is evidence that clonidine and dexmedetomidine can reduce postoperative shivering, but patients given dexmedetomidine may be more sedated

  15. Regularized Generalized Canonical Correlation Analysis

    Science.gov (United States)

    Tenenhaus, Arthur; Tenenhaus, Michel

    2011-01-01

    Regularized generalized canonical correlation analysis (RGCCA) is a generalization of regularized canonical correlation analysis to three or more sets of variables. It constitutes a general framework for many multi-block data analysis methods. It combines the power of multi-block data analysis methods (maximization of well identified criteria) and…

  16. Comparison of Antibiotic Therapy and Appendectomy for Acute Uncomplicated Appendicitis in Children: A Meta-analysis.

    Science.gov (United States)

    Huang, Libin; Yin, Yuan; Yang, Lie; Wang, Cun; Li, Yuan; Zhou, Zongguang

    2017-05-01

    Antibiotic therapy for acute uncomplicated appendicitis is effective in adult patients, but its application in pediatric patients remains controversial. To compare the safety and efficacy of antibiotic treatment vs appendectomy as the primary therapy for acute uncomplicated appendicitis in pediatric patients. The PubMed, MEDLINE, EMBASE, and Cochrane Library databases and the Cochrane Controlled Trials Register for randomized clinical trials were searched through April 17, 2016. The search was limited to studies published in English. Search terms included appendicitis, antibiotics, appendectomy, randomized controlled trial, controlled clinical trial, randomized, placebo, drug therapy, randomly, and trial. Randomized clinical trials and prospective clinical controlled trials comparing antibiotic therapy with appendectomy for acute uncomplicated appendicitis in pediatric patients (aged 5-18 years) were included in the meta-analysis. The outcomes included at least 2 of the following terms: success rate of antibiotic treatment and appendectomy, complications, readmissions, length of stay, total cost, and disability days. Data were independently extracted by 2 reviewers. The quality of the included studies was examined in accordance with the Cochrane guidelines and the Newcastle-Ottawa criteria. Data were pooled using a logistic fixed-effects model, and the subgroup pooled risk ratio with or without appendicolith was estimated. The primary outcome was the success rate of treatment. The hypothesis was formulated before data collection. A total of 527 articles were screened. In 5 unique studies, 404 unique patients with uncomplicated appendicitis (aged 5-15 years) were enrolled. Nonoperative treatment was successful in 152 of 168 patients (90.5%), with a Mantel-Haenszel fixed-effects risk ratio of 8.92 (95% CI, 2.67-29.79; heterogeneity, P = .99; I2 = 0%). Subgroup analysis showed that the risk for treatment failure in patients with appendicolith increased, with a

  17. Suicide by aircraft: a comparative analysis.

    Science.gov (United States)

    Bills, Corey B; Grabowski, Jurek George; Li, Guohua

    2005-08-01

    Suicide is the 11 th leading cause of death in the United States. The objective of this study is to document the characteristics of aviation-related suicides and suicide attempts. Aviation accidents reported by the National Transportation Safety Board between 1983 and 2003 were screened for cases in which suicide was listed as a probable cause. For each suicide case, two accidents were randomly selected as controls, matched on sex of pilot, type of flight, state, and year of occurrence. Mantel-Haenszel summary Chi-square tests were used to compare cases to controls. Conditional logistic regression modeling was performed to assess the association of pilot and flight characteristics with suicide-related crashes. During the 21-yr study period, 37 pilots committed or attempted suicide by aircraft, with 36 resulting in at least one fatality. All the cases were men and involved general aviation flights. Toxicological test results revealed that 24% of the cases had used alcohol and 14% had used other illicit drugs. Underlying factors included domestic and social problems (46%), legal trouble (40%), and pre-existing psychiatric conditions (38%). Compared with controls, suicide cases involved younger pilots (p aircraft (p crashes caused by suicide differ from unintentional aviation accidents in pilot characteristics, crash circumstances, and outcomes.

  18. Effect of gargling with tea and ingredients of tea on the prevention of influenza infection: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Kazuki Ide

    2016-05-01

    Full Text Available Abstract Background Influenza viruses can spread easily from person to person, and annual influenza epidemics are serious public health issues worldwide. Non-pharmaceutical public health interventions could potentially be effective for combatting influenza epidemics, but combined interventions and/or interventions with greater effectiveness are needed. Experimental studies have reported that tea and its ingredients (especially catechins have antiviral activities. Although several clinical studies have investigated the use of tea or its ingredients to prevent influenza infections, the effect of gargling these substances has remained uncertain. Methods We conducted a meta-analysis of randomized controlled studies and prospective cohort studies to assess the effect of gargling with tea and its ingredients on the prevention of influenza infection. The published literature was searched using the Cochrane Library, PubMed/MEDLINE (1966 to September 2015, Web of Science (1981 to September 2015, and Ichu-shi Web (1983 to September 2015. The extracted studies were read by two reviewers independently, and their overall scientific quality was evaluated. Studies meeting our inclusion criteria were pooled using the Mantel-Haenszel method in a fixed effects model and were also analyzed in a random effects model. The qualities of the model fits were assessed using the Akaike information criterion (AIC and Bayesian information criterion (BIC. Results The literature search and review identified 5 studies that met the inclusion criteria for the meta-analysis (total number of participants, 1890; mean age range, 16–83 years. The participants who gargled with tea or its ingredients showed a lower risk of influenza infection than did participants who gargled with placebo/water or who did not gargle (fixed effects model, Mantel-Haenszel method: relative risk [RR] = 0.70, 95 % confidence interval [CI] = 0.54–0.89; random effects model: RR = 0.71, 95

  19. Calcium supplementation and prevention of preeclampsia: a meta-analysis.

    Science.gov (United States)

    Patrelli, Tito Silvio; Dall'asta, Andrea; Gizzo, Salvatore; Pedrazzi, Giuseppe; Piantelli, Giovanni; Jasonni, Valerio Maria; Modena, Alberto Bacchi

    2012-12-01

    Since the early 1980s, epidemiological evidence has suggested a connection between low calcium intake and preeclampsia The purpose of this meta-analysis is to summarize current evidence regarding calcium supplementation during pregnancy in predicting preeclampsia and associated maternal-fetal complications. Literature revision of all RCT (random allocation of calcium versus placebo) available in MEDLINE/PUBMED up to 2/29/2012 regarding calcium supplementation during pregnancy for preventing preeclampsia. We used the Mantel-Haenszel's Method for four subgroup of patients: Adequate calcium intake; Low calcium intake; Low risk of preeclampsia; High risk of preeclampsia. We considered p prevention of preeclampsia, (2) other/adverse/long-term effects of calcium supplementation in pregnancy. Preeclampsia is likely to be a multifactorial disease. However, inadequate calcium intake represents a factor associated with an increased incidence of hypertensive disease. The results of our meta-analysis demonstrate that the additional intake of calcium during pregnancy is an effective measure to reduce the incidence of preeclampsia, especially in populations at high risk of preeclampsia due to ethnicity, gender, age, high BMI and in those with low baseline calcium intake.

  20. Generalized seismic analysis

    Science.gov (United States)

    Butler, Thomas G.

    1993-09-01

    There is a constant need to be able to solve for enforced motion of structures. Spacecraft need to be qualified for acceleration inputs. Truck cargoes need to be safeguarded from road mishaps. Office buildings need to withstand earthquake shocks. Marine machinery needs to be able to withstand hull shocks. All of these kinds of enforced motions are being grouped together under the heading of seismic inputs. Attempts have been made to cope with this problem over the years and they usually have ended up with some limiting or compromise conditions. The crudest approach was to limit the problem to acceleration occurring only at a base of a structure, constrained to be rigid. The analyst would assign arbitrarily outsized masses to base points. He would then calculate the magnitude of force to apply to the base mass (or masses) in order to produce the specified acceleration. He would of necessity have to sacrifice the determination of stresses in the vicinity of the base, because of the artificial nature of the input forces. The author followed the lead of John M. Biggs by using relative coordinates for a rigid base in a 1975 paper, and again in a 1981 paper . This method of relative coordinates was extended and made operational as DMAP ALTER packets to rigid formats 9, 10, 11, and 12 under contract N60921-82-C-0128. This method was presented at the twelfth NASTRAN Colloquium. Another analyst in the field developed a method that computed the forces from enforced motion then applied them as a forcing to the remaining unknowns after the knowns were partitioned off. The method was translated into DMAP ALTER's but was never made operational. All of this activity jelled into the current effort. Much thought was invested in working out ways to unshakle the analysis of enforced motions from the limitations that persisted.

  1. Use of the Endocuff during routine colonoscopy examination improves adenoma detection: A meta-analysis.

    Science.gov (United States)

    Chin, Matthew; Karnes, William; Jamal, M Mazen; Lee, John G; Lee, Robert; Samarasena, Jason; Bechtold, Matthew L; Nguyen, Douglas L

    2016-11-21

    To perform meta-analysis of the use of Endocuff during average risk screening colonoscopy. Scopus, Cochrane databases, MEDLINE/PubMed, and CINAHL were searched in April 2016. Abstracts from Digestive Disease Week, United European Gastroenterology, and the American College of Gastroenterology meeting were also searched from 2004-2015. Studies comparing EC-assisted colonoscopy (EAC) to standard colonoscopy, for any indication, were included in the analysis. The analysis was conducted by using the Mantel-Haenszel or DerSimonian and Laird models with the odds ratio (OR) to assess adenoma detection, cecal intubation rate, and complications performed. Nine studies ( n = 5624 patients) were included in the analysis. Compared to standard colonoscopy, procedures performed with EC had higher frequencies for adenoma (OR = 1.49, 95%CI: 1.23-1.80; P = 0.03), and sessile serrated adenomas detection (OR = 2.34 95%CI: 1.63-3.36; P detection without any difference in cecal intubation rates compared to standard colonoscopy.

  2. A meta-analysis of debulking surgery versus surgical biopsy for unresectable thymoma.

    Science.gov (United States)

    Hamaji, Masatsugu; Kojima, Fumitsugu; Omasa, Mitsugu; Sozu, Takashi; Sato, Tosiya; Chen, Fengshi; Sonobe, Makoto; Date, Hiroshi

    2015-04-01

    Observational studies on long-term outcomes following debulking surgery or surgical biopsy for unresectable thymoma showed various results. This meta-analysis was designed to determine the effect of debulking surgery against surgical biopsy on overall survival in patients with unresectable thymoma. The PubMed database was queried for studies published in the English language on unresectable thymoma and overall survival. We compared overall survival following surgery in patients undergoing debulking surgery and patients undergoing surgical biopsy for unresectable thymoma. Meta-analysis was performed using the Mantel-Haenszel method, and potential publication bias was evaluated with a funnel plot of precision. No randomized trials on this topic were identified. Thirteen retrospective observational studies containing a sum of 314 patients with information on the number of deaths and person-years were suitable for analysis. Information on Masaoka stages, World Health Organization histology and indications for debulking surgery versus surgical biopsy was lacking in most studies. Diversity of neoadjuvant and adjuvant treatments was noted among the eligible studies. One hundred and seventy-two (54.8%) patients underwent debulking surgery and 142 (45.2%) underwent surgical biopsy. The pooled hazard ratio was 0.451 (95% confidence interval: 0.336-0.605, P thymoma may be associated with improved overall survival and be considered for patients with unresectable thymoma. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  3. Prognostic role of IDH mutations in gliomas: a meta-analysis of 55 observational studies.

    Science.gov (United States)

    Xia, Liang; Wu, Bin; Fu, Zhiquan; Feng, Fang; Qiao, Enqi; Li, Qinglin; Sun, Caixing; Ge, Minghua

    2015-07-10

    IDH (Isocitrate dehydrogenase) mutations occur frequently in gliomas, but their prognostic impact has not been fully assessed. We performed a meta-analysis of the association between IDH mutations and survival in gliomas. Pubmed and EMBASE databases were searched for studies reporting IDH mutations (IHD1/2 and IDH1) and survival in gliomas. The primary outcome was overall survival (OS); the secondary outcome was progression-free survival (PFS). Hazard ratios (HR) with 95% confidence interval (CI) were determined using the Mantel-Haenszel random-effect modeling. Funnel plot and Egger's test were conducted to examine the risk of publication bias. Fifty-five studies (9487 patients) were included in the analysis. Fifty-four and twenty-seven studies investigated the association between IDH1/2 mutations and OS/PFS respectively in patients with glioma. The results showed that patients possessing an IDH1/2 mutation had significant advantages in OS (HR = 0.39, 95%CI: 0.34-0.45; P IDH mutations have improved OS and PFS, especially for patients with WHO grade III and grade II-III.

  4. Perinatal morbidity and mortality associated with chlamydial infection: a meta-analysis study

    Directory of Open Access Journals (Sweden)

    Maria José Penna Maisonnette de Attayde Silva

    Full Text Available OBJECTIVE: To evaluate the effect of Chlamydia trachomatis infection during pregnancy on perinatal morbidity and mortality. METHODS: Systematic review and meta-analysis in an electronic database and manual, combining high sensitivity specific descriptors seeking to answer the research objective. The articles considered to be of high methodological quality (score above 6 on the Newcastle-Ottawa Scale were assessed by meta-analysis. RESULTS: Summary estimates of 12 studies were calculated by means of Mantel-Haenszel test with 95% confidence interval. It was observed that Chlamydia infection during pregnancy increased risk of preterm labor (relative risk (RR = 1.35 [1.11, 1.63], low birth weight (RR = 1.52 [1.24, 1.87] and perinatal mortality (RR = 1.84 [1.15, 2.94]. No evidence of increased risk was associated with Chlamydia infection in regard to premature rupture of membranes (RR = 1.13 [0.95, 1.34], abortion and postpartum endometritis (RR = 1.20 [0.65, 2.20] and 0.89 [0.49, 1.61] respectively. CONCLUSION: The diagnosis and treatment of Chlamydia cervicitis during pregnancy can reduce perinatal morbidity and mortality associated with this infection. However, clinical trials are needed to confirm these findings.

  5. Prognostic value of HER-2/neu expression in epithelial ovarian cancer: a systematic review and meta-analysis.

    Science.gov (United States)

    Wang, Kai; Guan, Chenan; Yu, Junhui; Jin, Xiaoxiao; Sun, Ling; Zheng, Lingzhi; Xia, Liang; Zhang, Yuquan

    2017-09-26

    This study aimed to conduct a meta-analysis to investigate the association between human epidermal growth factor receptor 2 (HER-2/neu) expression and survival in patients with epithelial ovarian cancer (EOC). HER-2/neu is one of the most frequently studied molecular biological parameters in EOC, but its prognostic impact has not been fully assessed. PubMed and Embase were searched for studies that reported HER-2/neu expression and survival in patients with EOC. The primary outcome was overall survival (OS), and the secondary outcome was progression-free survival (PFS). Hazard ratios (HRs) with 95% confidence interval (CI) were determined using Mantel-Haenszel random-effects model. Publication bias was investigated using funnel plots and Egger's test. A total of 56 studies (N=7212) were included in the analysis. The results showed that patients possessing HER-2/neu expression had significant disadvantages in OS (HR = 1.41; 95%CI, 1.31 to 1.51; P present study findings provided further indication that HER-2/neu expression in patients with EOC has an adverse impact on OS and PFS.

  6. Role of statins in delirium prevention in critical ill and cardiac surgery patients: A systematic review and meta-analysis.

    Science.gov (United States)

    Vallabhajosyula, Saraschandra; Kanmanthareddy, Arun; Erwin, Patricia J; Esterbrooks, Dennis J; Morrow, Lee E

    2017-02-01

    The data evaluating the role of statins in delirium prevention in the intensive care unit are conflicting and limited. We performed a systematic review and meta-analysis of literature from 1975 to 2015. All English-language adult studies evaluating delirium incidence in statin and statin nonusers were included and studies without a control group were excluded. Mantel-Haenszel model was used to calculate pooled risk ratios (RRs) and 95% confidence intervals (CIs). Statistical significance was defined as CI not including unity and P value less than .05. Of a total 57 identified studies, 6 were included. The studies showed high heterogeneity (I 2 = 73%) for all and moderate for cardiac surgery studies (I 2 = 55%). Of 289 773 patients, statins were used in 22 292 (7.7%). Cardiac surgery was performed in 4382 (1.5%) patients and 2321 (53.0%) used statins. Delirium was noted in 710 (3.2%) and 3478 (1.3%) of the patients in the statin and nonstatin groups, respectively, with no difference between groups in the total cohort (RR, 1.05 [95% CI, 0.85-1.29]; P = .56) or in cardiac surgery patients (RR, 1.03 [95% CI, 0.68-1.56]; P = .89). In critically ill and cardiac surgery patients, this meta-analysis did not show a benefit with statin therapy in the prevention of delirium. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Mild therapeutic hypothermia in patients resuscitated from out-of-hospital cardiac arrest: A meta-analysis of randomized controlled trials

    Directory of Open Access Journals (Sweden)

    Pedro A Villablanca

    2016-01-01

    Full Text Available Aims: Guidelines recommend mild therapeutic hypothermia (MTH for survivors of out-of-hospital cardiac arrest (OHCA. However, there is little literature demonstrating a survival benefit. We performed a meta-analysis of randomized controlled trials (RCTs assessing the efficacy of MTH in patients successfully resuscitated from OHCA. Materials and Methods: Electronic databases were searched for RCT involving MTH in survivors of OHCA, and the results were put through a meta-analysis. The primary endpoint was all-cause mortality, and the secondary endpoint was favorable neurological function. Odds ratios (ORs and 95% confidence intervals (CIs were computed using the Mantel-Haenszel method. A fixed-effect model was used and, if heterogeneity (I2 was >40, effects were analyzed using a random model. Results: Six RCT (n = 1400 patients were included. Overall survival was 50.7%, and favorable neurological recovery was 45.5%. Pooled data demonstrated no significant all-cause mortality (OR, 0.81; 95% CI 0.55-1.21 or neurological recovery (OR, 0.77; 95% CI 0.47-1.24. No evidence of publication bias was observed. Conclusion: This meta-analysis demonstrated that MTH did not confer benefit on overall survival rate and neurological recovery in patients resuscitated from OHCA.

  8. A systematic review and quantitative analysis of neurocognitive outcomes in children with four chronic illnesses.

    Science.gov (United States)

    Moser, Joanna J; Veale, Pamela M; McAllister, Debbie L; Archer, David P

    2013-11-01

    reviewed by all four authors. All pertinent data related to the objectives were collected and independently reviewed by two authors. The data were summarized in the form reported in the studies. When possible, reported data were submitted to analysis with the Mantel-Haenszel method using a random effects model. Analyses were performed using the Review Manager computer program. In the studies retrieved, the main outcomes were measures of intellectual or cognitive characteristics, as exemplified by the Wechsler battery of tests. Reporting of measures of achievement (for example, GPA) was rare. Children with CF and hemophilia A did not appear disadvantaged by their disease as general intelligence levels were comparable with the general population norms. In children with ESRD, mean IQ reported during dialysis improved after transplantation. Although they improved relative to their pretransplantation cognitive functioning, children with ESLD who received transplants are approximately eight IQ points below the population norm. Overall, the results suggest that the burden of chronic childhood illness, by itself, does not impair cognitive development in children with hemophilia A and CF. Children with ESRD and ESLD, despite optimal management, show a mild cognitive deficit compared with the population norm. Given the impact of these four specific chronic illnesses on neurocognitive outcome in children and the improvement in IQ post-transplant in both ESRD and ESLD, the results suggest that the effect of an uncontrolled confounding illness on neurocognitive development is small. © 2013 John Wiley & Sons Ltd.

  9. Mineral trioxide aggregate versus formocresol pulpotomy: a systematic review and meta-analysis of randomized clinical trials.

    Science.gov (United States)

    Shirvani, Armin; Asgary, Saeed

    2014-05-01

    This study systematically reviewed randomized clinical trials (RCTs) investigating the effectiveness of primary molar pulpotomies with mineral trioxide aggregate (MTA) and formocresol. The study also aimed to assess the possible association of reported prognostic factors on the success rate and relative risk using meta-regression analysis. A comprehensive literature search using Medline, EMBASE, and Cochrane Central databases up to March 2013 was conducted. After scoring and data extraction of qualified trials (n = 19, representing 1,585 patients), meta-analyses were performed using Mantel-Haenszel model and inverse variance-weighted method. The results revealed that MTA is more effective than formocresol in primary molars pulpotomy, resulting in a lower failure rate with a relative risk of 0.26 (CI, 0.13-0.49), 0.37 (CI, 0.19-0.70), and 0.41 (CI, 0.25-0.68) for 6-, 12-, and 24-month follow-ups (test for statistical heterogeneity: p = 0.99, p = 0.98, and p = 0.23), respectively. Compared to amalgam restoration, success rate was significantly greater with SS crown (P formocresol. When compared with formocresol, MTA pulpotomy is superior in treating primary molars.

  10. Risk factors for postoperative delirium in patients undergoing major head and neck cancer surgery: a meta-analysis.

    Science.gov (United States)

    Zhu, Yun; Wang, Gangpu; Liu, Shengwen; Zhou, Shanghui; Lian, Ying; Zhang, Chenping; Yang, Wenjun

    2017-06-01

    Postoperative delirium is common after extensive surgery. This study aimed to collate and synthesize published literature on risk factors for delirium in patients with head and neck cancer surgery. Three databases were searched (MEDLINE, Embase, and Cochrane Library) between January 1987 and July 2016. The Newcastle Ottawa Scale (NOS) was adopted to evaluate the study quality. Pooled odds ratios or mean differences for individual risk factors were estimated using the Mantel-Haenszel and inverse-variance methods. They provided a total of 1940 patients (286 with delirium and 1654 without), and predominantly included patients undergoing head and neck cancer surgery. The incidence of postoperative delirium ranged from 11.50% to 36.11%. Ten statistically significant risk factors were identified in pooled analysis. Old age, age >70 years, male sex, duration of surgery, history of hypertension, blood transfusions, tracheotomy, American Society of Anesthesiologists physical status grade at least III, flap reconstruction and neck dissection were more likely to sustain delirium after head and neck cancer surgery. Delirium is common in patients undergoing major head neck cancer surgery. Several risk factors were consistently associated with postoperative delirium. These factors help to highlight patients at risk of developing delirium and are suitable for preventive action. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  11. Role of implantable cardioverter defibrillator in non-ischemic cardiomyopathy: a systematic review and meta-analysis of prospective randomized clinical trials.

    Science.gov (United States)

    Romero, Jorge; Chaudhary, Rahul; Garg, Jalaj; Lupercio, Florentino; Shah, Neeraj; Gupta, Rahul; Nazir, Talha; Bozorgnia, Babak; Natale, Andrea; Di Biase, Luigi

    2017-09-01

    A mortality benefit in patients with implantable cardioverter defibrillator (ICD) in ischemic cardiomyopathy is well established. However, the benefit of ICD implantation in non-ischemic cardiomyopathy (NICM) on total mortality remains uncertain. We performed a systematic review and meta-analysis of randomized controlled trials (RCT) evaluating the role of primary prevention ICD in NICM patients. We performed a systematic review on PubMed, The Cochrane Library, EMBASE, EBSCO, Web of Science, and CINAHL databases from the inception through February 2017 to identify RCT evaluating the role of ICD in NICM patients. Mantel-Haenszel risk ratio (RR) fixed effects model was used to summarize data across treatment arms. If heterogeneity (I 2 ) ≥25, random effects model was used instead. We analyzed a total of 2573 patients from five RCTs comparing ICD with medical therapy in patients with NICM. The mean follow up for the trials was 48 ± 22 months. There was a significant reduction in (a) all-cause mortality (RR 0.84, 95% CI 0.71-0.99, p = 0.03) and (b) sudden cardiac death (RR 0.47, 95% CI 0.30-0.73, p < 0.001) in ICD group versus medical therapy. Our analysis demonstrates that the use of ICD for primary prevention is associated with a reduction in all-cause mortality and SCD in patients with NICM.

  12. Risk of bone fractures associated with glucagon-like peptide-1 receptor agonists' treatment: a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Su, Bin; Sheng, Hui; Zhang, Manna; Bu, Le; Yang, Peng; Li, Liang; Li, Fei; Sheng, Chunjun; Han, Yuqi; Qu, Shen; Wang, Jiying

    2015-02-01

    Traditional anti-diabetic drugs may have negative or positive effects on risk of bone fractures. Yet the relationship between the new class glucagon-like peptide-1 receptor agonists (GLP-1 RA) and risk of bone fractures has not been established. We performed a meta-analysis including randomized controlled trials (RCT) to study the risk of bone fractures associated with liraglutide or exenatide, compared to placebo or other active drugs. We searched MEDLINE, EMBASE, and clinical trial registration websites for published or unpublished RCTs comparing the effects of liraglutide or exenatide with comparators. Only studies with disclosed bone fracture data were included. Separate pooled analysis was performed for liraglutide or exenatide, respectively, by calculating Mantel-Haenszel odds ratio (MH-OR). 16 RCTs were identified including a total of 11,206 patients. Liraglutide treatment was associated with a significant reduced risk of incident bone fractures (MH-OR=0.38, 95% CI 0.17-0.87); however, exenatide treatment was associated with an elevated risk of incident bone fractures (MH-OR=2.09, 95% CI 1.03-4.21). Publication bias and heterogeneity between studies were not observed. Our study demonstrated a divergent risk of bone fractures associated with different GLP-1 RA treatments. The current findings need to be confirmed by future well-designed prospective or RCT studies.

  13. Is Ki-67 of Diagnostic Value in Distinguishing Between Partial and Complete Hydatidiform Moles? A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Zhao, Yue; Xiong, Guang-Wu; Zhang, Xiao-Wei; Hang, B O

    2018-02-01

    To demonstrate the value of Ki-67 in distinguishing between partial and complete hydatidiform moles. We searched electronic databases included Medline, WOK, Cochrane Library and CNKI, through January 24, 2015. Experts were consulted, and references from related articles were examined. The meta-analysis was conducted with RevMan5.3, according to the PRISMA guidelines. Mantel-Haenszel estimates were calculated and pooled under a random effect model, with data expressed as odds ratio (OR) and 95% confidence interval (CI). We analyzed eight trials with a total of 337 participants who underwent uterine curettage and met the inclusion criteria. A significantly higher expression of Ki-67 was observed in complete than in partial hydatidiform moles (OR=3.28; 95%CI=1.80-5.96; pvalue in distinguishing between partial and complete hydatidiform moles. However, the present study had only a limited number of samples, so investigation of a greater number of cases is needed to confirm this conclusion. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  14. An Exploratory Analysis of Differential Item Functioning and Its Possible Sources in a Higher Education Admissions Context

    Science.gov (United States)

    Oliveri, Maria Elena; Lawless, Rene; Robin, Frederic; Bridgeman, Brent

    2018-01-01

    We analyzed a pool of items from an admissions test for differential item functioning (DIF) for groups based on age, socioeconomic status, citizenship, or English language status using Mantel-Haenszel and item response theory. DIF items were systematically examined to identify its possible sources by item type, content, and wording. DIF was…

  15. Generalized canonical correlation analysis with missing values

    NARCIS (Netherlands)

    M. van de Velden (Michel); Y. Takane

    2012-01-01

    textabstractGeneralized canonical correlation analysis is a versatile technique that allows the joint analysis of several sets of data matrices. The generalized canonical correlation analysis solution can be obtained through an eigenequation and distributional assumptions are not required. When

  16. Dimensional Analysis and General Relativity

    Science.gov (United States)

    Lovatt, Ian

    2009-01-01

    Newton's law of gravitation is a central topic in the first-year physics curriculum. A lecturer can go beyond the physical details and use the history of gravitation to discuss the development of scientific ideas; unfortunately, the most recent chapter in this history, general relativity, is not covered in first-year courses. This paper discusses…

  17. A Bayesian Method for Studying DIF: A Cautionary Tale Filled with Surprises and Delights

    Science.gov (United States)

    Wang, Xiaohui; Bradlow, Eric T.; Wainer, Howard; Muller, Eric S.

    2008-01-01

    In the course of screening a form of a medical licensing exam for items that function differentially (DIF) between men and women, the authors used the traditional Mantel-Haenszel (MH) statistic for initial screening and a Bayesian method for deeper analysis. For very easy items, the MH statistic unexpectedly often found DIF where there was none.…

  18. Investigating item and construct bias in an English verbal analogies ...

    African Journals Online (AJOL)

    This was achieved by utilising differential item functioning (DIF) and construct bias statistical techniques. The Mantel-Haenszel DIF detection method was employed to detect DIF, while construct equivalence was examined by means of exploratory factor analysis (EFA) utilising an a priori two-factor structure. The Tucker's phi ...

  19. Risk factors for coronary heart disease in the white comm.unity ...

    African Journals Online (AJOL)

    the Cochran-Mantel-Haenszel (CMH) test was used to assess the overall association. In cases where significant associations were found, odds ratios and 95% confi- dence intervals were calculated. For the association between CHD and risk factors an analysis stratified for age and sex was performed. Homogeneity of ...

  20. Clinical Validation of the "Sedentary Lifestyle" Nursing Diagnosis in Secondary School Students

    Science.gov (United States)

    de Oliveira, Marcos Renato; da Silva, Viviane Martins; Guedes, Nirla Gomes; de Oliveira Lopes, Marcos Venícios

    2016-01-01

    This study clinically validated the nursing diagnosis of "sedentary lifestyle" (SL) among 564 Brazilian adolescents. Measures of diagnostic accuracy were calculated for defining characteristics, and Mantel--Haenszel analysis was used to identify related factors. The measures of diagnostic accuracy showed that the following defining…

  1. ORIGINAL ARTICLES Vaginal microbicides for preventing mother-to ...

    African Journals Online (AJOL)

    the effect of microbicides on.MTCT of HIV, extracteq data in triplicate, as1>es!;eo statistical heterogeneity between trial results, and conducted meta-analysis using Mantel-Haenszel's ... Tilbcrculosis Vaccine Initiative, Institute of Infectious Diseases and ... 1.20} and found that adverse effects decreased in neonates (RR.

  2. Association between Fever and Primary Tooth Eruption: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    A Nemezio, Mariana; Mh De Oliveira, Katharina; C Romualdo, Priscilla; M Queiroz, Alexandra; Wg Paula-E-Silva, Francisco; Ab Silva, Raquel; C Küchler, Erika

    2017-01-01

    To perform a systematic review and meta-analysis to establish if fever is associated with primary tooth eruption. Literature searches involved Pubmed, MEDLINE, Web of Science, Scopus and Cochrane. The potentially relevant studies had the full text analyzed. Only studies concerning fever during eruption period of primary tooth in humans were included. Papers in non-English language, and papers that included syndromic patients or patients with any disease were excluded. The meta-analyses were performed with Review Manager (version 5.3). Only studies that reported the results as dichotomous data were analyzed with Cochran-Mantel-Haenszel test in meta-analysis function of Review Manager 5.3. The fixed-effects model was used to evaluate the association between tooth eruption and fever. Search identified 83 potential studies. After exclusion of the duplicated studies, or were not related to the criteria of inclusion only 6 studies were selected for the systematic review. In the overall meta-analysis, no association was found [OR = 1.32 (0.88-1.96)] between fever and primary tooth eruption. However, in the subgroup analysis, when the method used to measure fever was the rectal temperature there was an association [OR = 2.82 (1.55-5.14)] between fever and primary tooth eruption. There are few suitable studies in the literature regarding the association between primary tooth eruption and fever. However, our study found an association between fever and primary tooth eruption only when rectal temperature was performed. Nemezio MA, De Oliveira KMH, Romualdo PC, Queiroz AM, Paula-e-Silva FWG, Silva RAB, Kuchler EC. Association between Fever and Primary Tooth Eruption: A Systematic Review and Meta-analysis. Int J Clin Pediatr Dent 2017;10(3):293-298.

  3. Generalized canonical correlation analysis with missing values

    NARCIS (Netherlands)

    M. van de Velden (Michel); Y. Takane

    2009-01-01

    textabstractTwo new methods for dealing with missing values in generalized canonical correlation analysis are introduced. The first approach, which does not require iterations, is a generalization of the Test Equating method available for principal component analysis. In the second approach,

  4. Do pacifiers reduce the risk of sudden infant death syndrome? A meta-analysis.

    Science.gov (United States)

    Hauck, Fern R; Omojokun, Olanrewaju O; Siadaty, Mir S

    2005-11-01

    Pacifier use has been reported to be associated with a reduced risk of sudden infant death syndrome (SIDS), but most countries around the world, including the United States, have been reluctant to recommend the use of pacifiers because of concerns about possible adverse effects. This meta-analysis was undertaken to quantify and evaluate the protective effect of pacifiers against SIDS and to make a recommendation on the use of pacifiers to prevent SIDS. We searched the Medline database (January 1966 to May 2004) to collect data on pacifier use and its association with SIDS, morbidity, or other adverse effects. The search strategy included published articles in English with the Medical Subject Headings terms "sudden infant death syndrome" and "pacifier" and the keywords "dummy" and "soother." Combining searches resulted in 384 abstracts, which were all read and evaluated for inclusion. For the meta-analysis, articles with data on the relationship between pacifier use and SIDS risk were limited to published original case-control studies, because no prospective observational reports were found; 9 articles met these criteria. Two independent reviewers evaluated each study on the basis of the 6 criteria developed by the American Academy of Pediatrics Task Force on Infant Positioning and SIDS; in cases of disagreement, a third reviewer evaluated the study, and a consensus opinion was reached. We developed a script to calculate the summary odds ratio (SOR) by using the reported ORs and respective confidence intervals (CI) to weight the ORs. We then pooled them together to compute the SOR. We performed the Breslow-Day test for homogeneity of ORs, Cochran-Mantel-Haenszel test for the null hypothesis of no effect (OR = 1), and the Mantel-Haenszel common OR estimate. The consistency of findings was evaluated and the overall potential benefits of pacifier use were weighed against the potential risks. Our recommendation is based on the taxonomy of the 5-point (A-E) scale adopted

  5. Terpene compound drug as medical expulsive therapy for ureterolithiasis: a meta-analysis.

    Science.gov (United States)

    Chua, Michael Erlano; Park, Jane Hyeon; Castillo, Josefino Cortez; Morales, Marcelino Lopeztan

    2013-04-01

    The aim of this study is to investigate the efficacy of terpene compound drug (pinene, camphene, borneol, anethole, fenchone and cineol in olive oil) in facilitating spontaneous passage of ureteral calculi through meta-analysis of randomized controlled trials (RCT). Systematic literature search on MEDLINE, EMBASE, OVID, Science Direct, Proquest, Google scholar, Cochrane Library databases and reference list of related literatures were done without language restriction. RCTs on ureterolithiasis medical expulsive therapy (MET) that compare terpene compound drug versus placebo/control group or alpha-blockers were identified. Articles retrieved were critically appraised by two independent reviewers according to Cochrane Collaboration recommendations. Data from included studies were extracted for calculation of risk ratio (RR) and 95 % confidence interval (CI). Effect estimates were pooled using Mantel-Haenszel method with random effect model. Inter-study heterogeneity and publication bias were assessed. The PRISMA guidelines for meta-analysis reporting were followed. Five RCTs (total of 344 subjects) of adequate methodological quality were included. Pooled effect estimates from homogenous studies showed that compared to placebo/control group, patients treated with terpene compound drug had significantly better ureteral calculi spontaneous expulsion rate (pooled RR: 1.34; 95 % CI 1.12, 1.61). Subgroup analysis of studies that compare terpene compound drug with alpha-blockers showed no significant difference (pooled RR: 0.79; 95 % CI 0.59, 1.06), while significant inter-study heterogeneity was noted. Only minor gastrointestinal adverse effect was reported on terpene compound drug use. The results suggest that terpene compound drug as MET is effective in augmenting spontaneous passage of ureterolithiasis. High quality large-scale RCTs comparing alpha-blockers and terpene compound drug are warranted to make a more definitive conclusion.

  6. Outcomes following polyetheretherketone (PEEK) cranioplasty: Systematic review and meta-analysis.

    Science.gov (United States)

    Punchak, Maria; Chung, Lawrance K; Lagman, Carlito; Bui, Timothy T; Lazareff, Jorge; Rezzadeh, Kameron; Jarrahy, Reza; Yang, Isaac

    2017-07-01

    Polyetheretherketone (PEEK) has been used in cranioplasty since the early 2000s. However, there remains limited data that compares its long-term complication rate to autologous grafts and titanium mesh implants. To compare complication and implant failure rates after PEEK, autologous and titanium mesh cranioplasties, the authors of this study conducted a systematic review using the PubMed database. Studies that contained outcome data on complication rates of PEEK cranioplasty patients and studies that compared outcomes of patients who underwent PEEK cranioplasties versus other materials were included in the meta-analysis. Pooled odds ratios using the Mantel-Haenszel method were used for analysis. Fifteen articles, comprised of 183 PEEK cranioplasty patients were included. Of these patients, 15.3% developed post-operative complications and 8.7% experienced implant failure requiring reoperation. Patients who underwent cranioplasties with PEEK implants had 0.130 times the odds of developing post-operative complications (P=0.065) and 0.574 times the odds of implant failure compared to patients with autologous bone graft cranioplasties (P=0.629). Patients who had undergone PEEK cranioplasties had 0.127 times the odds of developing post-op complications (P=0.360) and 0.170 times the odds of implant failure compared to individuals who had undergone titanium mesh cranioplasties (P=0.168). The analysis was severely limited by the paucity in literature. However, there was a trend toward lower post-operative complication rates following PEEK cranioplasty versus autologous grafts, and lower implant failure rates with PEEK versus titanium mesh implants. Copyright © 2017. Published by Elsevier Ltd.

  7. Total abdominal hysterectomy versus minimal-invasive hysterectomy: a systemic review and meta-analysis

    International Nuclear Information System (INIS)

    Aragon Palmero, Felipe Jorge; Exposito Exposito, Moises

    2011-01-01

    INTRODUCTION. At the present time three types of hysterectomies are used: the vaginal hysterectomy and the minimal-invasive hysterectomy (MIH). The objective of present research was to compare the MIH and the total abdominal hysterectomy (TAH) in women presenting with benign uterine diseases. METHODS. A systemic review was made and a meta-analysis from the following databases: MEDLINE, EBSCO HOST AND The Cochrane Central Register of Controlled Trials. Only the controlled and randomized studies were selected. The data of all studies were combined and also the relative risk (RR) with a 95% CI was used with the Mantel-Haenszel method as an effect measure for dichotomy variables. For the analysis of continuing variables the mean difference was used. In all the comparisons performed the results were obtained with the fix effect and randomized forms. RESULTS. A total of 53 transoperative complications were registered in the MIH hysterectomy versus 17 in the TAH group (RR: 1,78; 95% CI: 1,04-3.05). Postoperative complications evolved in a similar way in both groups without significant differences from the statistical point of view. The blood losses, the hospital stay and the patient's reincorporation to usual and work activities were lesser in the laparoscopy group; however, the operative time is higher when it is compared with TAH (mean difference: 37,36; 95% CI: 34,36-39,93). CONCLUSIONS. Both techniques have advantages and disadvantages. The indication of MIH must to be individualized according to the clinical situation of each patient and these not to be performed in those centers without a properly trained surgical staff and with experience in advanced minimal invasive surgery. (author)

  8. Traditional cardiovascular risk factors and coronary collateral circulation: Protocol for a systematic review and meta-analysis of case-control studies.

    Science.gov (United States)

    Xing, Zhenhua; Pei, Junyu; Tang, Liang; Hu, Xinqun

    2018-04-01

    Well-developed coronary collateral circulation usually results in fewer infarct size, improved cardiac function, and fewer mortality. Traditional coronary risk factors (diabetes, hypertension, and smoking) have some effects on coronary collateral circulation. However, the association between these risk factors and coronary collateral circulation are controversial. Given the confusing evidences regarding traditional cardiovascular risk factors on coronary collateral circulation, we performed this meta-analysis protocol to investigate the relationship between traditional risk factors of coronary artery disease and coronary collateral circulation. MEDINE, EMBASE, and Science Citation Index will be searched to identify relevant studies. The primary outcomes of this meta-analysis are well-developed coronary collateral circulation. Meta-analysis was performed to calculate the odds ratio (OR) and 95% confidence interval (CI) of traditional coronary risk factors (diabetes, smoking, hypertriton). Pooled ORs were computed as the Mantel-Haenszel-weighted average of the ORs for all included studies. Sensitivity analysis, quality assessment, publication bias analysis, and the Grading of Recommendations Assessment, Development and Evaluation approach (GRADE) will be performed to ensure the reliability of our results. This study will provide a high-quality synthesis of current evidence of traditional risk factors on collateral circulation. This conclusion of our systematic review and meta-analysis will provide evidence to judge whether traditional risk factors affects coronary collateral circulation.Ethics and dissemination: Ethical approval is not required because our systematic review and meta-analysis will be based on published data without interventions on patients. The findings of this study will be published in a peer-reviewed journal.

  9. Oral versus intravenous methylprednisolone for the treatment of multiple sclerosis relapses: A meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Liu, Shuo; Liu, Xiaoqiang; Chen, Shuying; Xiao, Yingxiu; Zhuang, Weiduan

    2017-01-01

    Intravenous glucocorticoids are recommended for multiple sclerosis (MS). However, they can be inconvenient and expensive. Due to their convenience and low cost, oral glucocorticoids may be an alternative treatment. Recently, several studies have shown that there is no difference in efficacy and safety between oral methylprednisolone (oMP) and intravenous methylprednisolone (ivMP). We sought to assess the clinical efficacy, safety and tolerability of oral methylprednisolone versus intravenous methylprednisolone for MS relapses in this meta-analysis. Randomized controlled trials (RCTs) evaluating the clinical efficacy, safety and tolerability of oral methylprednisolone versus intravenous methylprednisolone for MS relapses were searched in PubMed, Cochrane Library, Medline, EMBASE and China Biology Medicine until October 25, 2016, without language restrictions. The proportion of patients who had improved by day 28 was chosen as the efficacy outcome. We chose the risk ratio (RR) to analyze each trial with the 95% confidence interval (95% CI). We also used the fixed-effects model (Mantel-Haenszel approach) to calculate the pooled relative effect estimates. A total of 5 trials were identified, which included 369 patients. The results of our meta-analysis revealed that no significant difference existed in relapse improvement at day 28 between oMP and ivMP (RR 0.96, 95% CI 0.84 to 1.10). No evidence of heterogeneity existed among the trials (P = 0.45, I2 = 0%). Both treatments were equally safe and well tolerated except that insomnia was more likely to occur in the oMP group compared to the ivMP group. Our meta-analysis reveals strong evidence that oMP is not inferior to ivMP in increasing the proportion of patients experiencing clinical improvement at day 28. In addition, both routes of administration are equally well tolerated and safe. These findings suggest that we may be able to replace ivMP with oMP to treat MS relapses.

  10. Transversus abdominis plane (tap) block in laparoscopic colorectal surgery improves postoperative pain management: a meta-analysis.

    Science.gov (United States)

    Hain, Elisabeth; Maggiori, Léon; Prost À la Denise, Justine; Panis, Yves

    2018-01-30

    Transversus abdominis plane (TAP) block is a locoregional anesthesia technique of growing interest in abdominal surgery. However, its efficacy following laparoscopic colorectal surgery is still debated. This meta-analysis aimed to assess the efficacy of TAP-block after laparoscopic colorectal surgery. All comparative studies focusing on TAP-block after laparoscopic colorectal surgery have been systematically identified through the MEDLINE database, reviewed and included. Meta-analysis was performed according to the Mantel-Haenszel method for random effects. Endpoints included postoperative opioid consumption, morbidity, time to first bowel movement and length of hospital stay. A total of 13 studies, including 7 randomized controlled trials, were included, comprising a total of 600 patients who underwent laparoscopic colorectal surgery with TAP-block, compared to 762 patients without TAP-Block. Meta-analysis of these studies showed that TAP-block was associated with a significantly reduced postoperative opioid consumption the first day after surgery (Weighted Mean Difference (WMD): -14.54 [-25.14; -3.94]; p=0.007) and a significantly shorter time to first bowel movement (WMD: -0.53 [-0.61; -0.44]; pTAP-block was not associated with a significant increase of postoperative overall complication rate (OR=0.84 [0.62 - 1.14]; p=0.27). TAP-block in laparoscopic colorectal surgery improves postoperative opioid consumption and postoperative digestive function recovery without any significant drawback. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  11. Meta-analysis of randomized, controlled trials comparing particular doses of griseofulvin and terbinafine for the treatment of tinea capitis.

    Science.gov (United States)

    Gupta, Aditya K; Drummond-Main, Chris

    2013-01-01

    Two oral antifungal agents, griseofulvin and terbinafine, have regulatory approval in the United States, but it is unknown whether one has superior overall efficacy. Genus-specific differences in efficacy are believed to exist for the two agents. It is not clear at what doses and durations of treatment these differences apply. The goals of this meta-analysis were to determine whether a statistically significant difference in efficacy exists between these agents at a given dose and duration of each in tinea capitis infections overall and to determine whether a genus-specific difference in efficacy exists for these two treatments at a given dose and duration of each. We performed a literature search for clinically and methodologically similar randomized controlled trials comparing 8 weeks of griseofulvin (6.25-12.5 mg/kg/day) to 4 weeks of terbinafine (3.125-6.25 mg/kg/day) in the treatment of tinea capitis. A meta-analysis was performed using the Mantel-Haenszel method and random effects model; results were expressed as odds ratios with 95% confidence intervals. Meta-analysis of randomized controlled trials did not show a significant difference in the overall efficacy of the two drugs at the doses specified, but specific efficacy differences were observed based on the infectious species. For tinea capitis caused by Microsporum spp., griseofulvin is superior (p = 0.04), whereas terbinafine is superior for Trichophyton spp. infection (p = 0.04). Our results support species-specific differences in treatment efficacy between griseofulvin and terbinafine and provide a clinical context in which this knowledge may be applied. © 2012 Wiley Periodicals, Inc.

  12. Angioplasty Guided by Intravascular Ultrasound: Meta-Analysis of Randomized Clinical Trials

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, José Albuquerque Neto de, E-mail: jafneto@cardiol.br; Nogueira, Iara Antonia Lustosa [Universidade Federal do Maranhão, São Luiz, MA (Brazil); Figueiro, Mabel Fernandes; Buehler, Anna Maria; Berwanger, Otavio [Instituto de Ensino e Pesquisa do Hospital do Coração, São Paulo, SP (Brazil)

    2013-08-15

    The impact of intravascular ultrasound (IVUS) use on stenting has shown inconclusive results. Systematic review and meta-analysis of the impact of IVUS on stenting regarding the clinical and angiographic evolution. A search was performed in Medline/Pubmed, CENTRAL, Embase, Lilacs, Scopus and Web of Science databases. It included randomized clinical trials (RCTs) that evaluated the implantation of stents guided by IVUS, compared with those using angiography alone (ANGIO). The minimum follow-up duration was six months and the following outcomes were assessed: thrombosis, mortality, myocardial infarction, percutaneous and surgical revascularization, major adverse cardiovascular events (MACE) and restenosis. The binary outcomes were presented considering the number of events in each group; the estimates were generated by a random effects model, considering Mantel-Haenszel statistics as weighting agent and magnitude of effect for the relative risk (RR) with its respective 95% confidence interval (95%CI). Higgins I{sup 2} test was used to quantify the consistency between the results of each study. A total of 2,689 articles were evaluated, including 8 RCTs. There was a 27% reduction in angiographic restenosis (RR: 0.73, 95% CI: 0.54-0.97, I{sup 2} = 51%) and statistically significant reduction in the rates of percutaneous revascularization and overall (RR: 0.88; 95% CI: 0.51 to 1.53, I{sup 2} = 61%, RR: 0.73, 95% CI: 0.54 to 0.99, I{sup 2} = 55%), with no statistical difference in surgical revascularization (RR: 0.95, 95% CI: 0.52-1.74, I{sup 2} = 0%) in favor of IVUS vs. ANGIO. There were no differences regarding the other outcomes in the comparison between the two strategies. Angioplasty with stenting guided by IVUS decreases the rates of restenosis and revascularization, with no impact on MACE, acute myocardial infarction, mortality or thrombosis outcomes.

  13. CHLORHEXIDINE-IMPREGNATED DRESSING FOR PREVENTION OF CATHETER-RELATED BLOODSTREAM INFECTION: A META-ANALYSIS

    Science.gov (United States)

    Safdar, Nasia; O’Horo, John C.; Ghufran, Aiman; Bearden, Allison; Didier, Maria Eugenia; Chateau, Dan; Maki, Dennis G.

    2014-01-01

    Background Catheter related bloodstream infections (CRBSI) are associated with significant morbidity and mortality and effective methods for their prevention are needed. Objective To assess the efficacy of a chlorhexidine-impregnated dressing for prevention of central venous catheter-related colonization and CRBSI using meta-analysis. Data Sources Multiple computerized database searches supplemented by manual searches including relevant conference proceedings. Study Selection Randomized controlled trials (RCT) evaluating the efficacy of a chlorhexidine-impregnated dressing compared with conventional dressings for prevention of catheter colonization and CRBSI. Data Extraction Data were extracted on patient and catheter characteristics and outcomes. Data Synthesis Pooled estimates of the relative risk (RR) and 95% confidence intervals (CI) were obtained using the DerSimonian and Laird random effects model and the Mantel-Haenszel fixed effects model. Heterogeneity was assessed using the Cochran Q statistic and I2. Subgroup analyses were used to explore heterogeneity. Results Nine RCTs met the inclusion criteria. Use of a chlorhexidine-impregnated dressing resulted in a reduced incidence of CRBSI (random effects RR 0.57, 95% CI 0.42–0.79, P=0.002). The incidence of catheter colonization was also markedly reduced in the chlorhexidine-impregnated dressing group (random effects RR 0.51, 95% CI 0.39–0.67, Pchlorhexidine-impregnated dressing is beneficial in preventing catheter colonization and, more importantly, CRBSI and warrants routine use in patients at high risk of CRBSI and CVC or arterial catheter colonization in ICUs. PMID:24674924

  14. The Relationship between Diabetic Neuropathy and Sleep Apnea Syndrome: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Kazuya Fujihara

    2013-01-01

    Full Text Available Aims. High prevalence of sleep apnea syndrome (SAS has been reported in patients with diabetes. However, whether diabetic neuropathy (DN contributes to this high prevalence is controversial. Our aim of this study is to compare the prevalence of SAS between patients with and without DN. Methods. Systematic literature searches were conducted for cross-sectional studies that reported the number of patients with DN and SAS using MEDLINE (from 1966 to Nov 5, 2012 and EMBASE (from 1974 to Nov 5, 2012. Odds ratios (ORs of SAS related to DN were pooled with the Mantel-Haenszel method. Results. Data were obtained from 5 eligible studies (including 6 data sets, 880 participants, and 429 cases. Overall, the pooled OR of SAS in patients with DN compared with that in non-DN patients was significant (OR (95% CI, −1.95 (1.03–3.70. The pooled OR of SAS was 1.90 (0.97–3.71 in patients with type 2 diabetes. Excluding data on patients with type 1 diabetes, a higher OR was observed in younger patients (mean age <60 years than in those ≥60 years among whom the OR remained significant (3.82; 95% CI, 2.24–6.51 and 1.17; 95% CI, 0.81–1.68. Conclusions. Current meta-analysis suggested the association of some elements of neuropathy with SAS in type 2 diabetes. Further investigations are needed to clarify whether the association is also true for patients with type 1 diabetes.

  15. The Relationship between Diabetic Neuropathy and Sleep Apnea Syndrome: A Meta-Analysis

    Science.gov (United States)

    Horikawa, Chika; Hirasawa, Reiko; Shimano, Hitoshi; Suzuki, Akiko; Hanyu, Osamu; Sone, Hirohito

    2013-01-01

    Aims. High prevalence of sleep apnea syndrome (SAS) has been reported in patients with diabetes. However, whether diabetic neuropathy (DN) contributes to this high prevalence is controversial. Our aim of this study is to compare the prevalence of SAS between patients with and without DN. Methods. Systematic literature searches were conducted for cross-sectional studies that reported the number of patients with DN and SAS using MEDLINE (from 1966 to Nov 5, 2012) and EMBASE (from 1974 to Nov 5, 2012). Odds ratios (ORs) of SAS related to DN were pooled with the Mantel-Haenszel method. Results. Data were obtained from 5 eligible studies (including 6 data sets, 880 participants, and 429 cases). Overall, the pooled OR of SAS in patients with DN compared with that in non-DN patients was significant (OR (95% CI), −1.95 (1.03–3.70)). The pooled OR of SAS was 1.90 (0.97–3.71) in patients with type 2 diabetes. Excluding data on patients with type 1 diabetes, a higher OR was observed in younger patients (mean age <60 years) than in those ≥60 years among whom the OR remained significant (3.82; 95% CI, 2.24–6.51 and 1.17; 95% CI, 0.81–1.68). Conclusions. Current meta-analysis suggested the association of some elements of neuropathy with SAS in type 2 diabetes. Further investigations are needed to clarify whether the association is also true for patients with type 1 diabetes. PMID:24381764

  16. Analysis of recurrent event data under the case-crossover design with applications to elderly falls.

    Science.gov (United States)

    Luo, Xianghua; Sorock, Gary S

    2008-07-10

    The case-crossover design is useful for studying the effects of transient exposures on short-term risk of diseases or injuries when only data on cases are available. The crossover nature of this design allows each subject to serve as his/her own control. While the original design was proposed for univariate event data, in many applications recurrent events are encountered (e.g. elderly falls, gout attacks, and sexually transmitted infections). In such situations, the within-subject dependence among recurrent events needs to be taken into account in the analysis. We review three existing conditional logistic regression (CLR)-based approaches for recurrent event data under the case-crossover design. A simple approach is to use only the first event for each subject; however, we would expect loss of efficiency in estimation. The other two reviewed approaches rely on independence assumptions for the recurrent events, conditionally on a set of covariates. Furthermore, we propose new methods that adjust the CLR using either a within-subject pairwise resampling technique or a weighted estimating equation. No specific dependency structure among recurrent events is needed therein, and hence, they have more flexibility than the existing methods in the situations with unknown correlation structures. We also propose a weighted Mantel-Haenszel estimator, which is easy to implement for data with a binary exposure. In simulation studies, we show that all discussed methods yield virtually unbiased estimates when the conditional independence assumption holds. These methods are illustrated using data from a study of the effect of medication changes on falls among the elderly. (c) 2007 John Wiley & Sons, Ltd.

  17. Angioplasty Guided by Intravascular Ultrasound: Meta-Analysis of Randomized Clinical Trials

    International Nuclear Information System (INIS)

    Figueiredo, José Albuquerque Neto de; Nogueira, Iara Antonia Lustosa; Figueiro, Mabel Fernandes; Buehler, Anna Maria; Berwanger, Otavio

    2013-01-01

    The impact of intravascular ultrasound (IVUS) use on stenting has shown inconclusive results. Systematic review and meta-analysis of the impact of IVUS on stenting regarding the clinical and angiographic evolution. A search was performed in Medline/Pubmed, CENTRAL, Embase, Lilacs, Scopus and Web of Science databases. It included randomized clinical trials (RCTs) that evaluated the implantation of stents guided by IVUS, compared with those using angiography alone (ANGIO). The minimum follow-up duration was six months and the following outcomes were assessed: thrombosis, mortality, myocardial infarction, percutaneous and surgical revascularization, major adverse cardiovascular events (MACE) and restenosis. The binary outcomes were presented considering the number of events in each group; the estimates were generated by a random effects model, considering Mantel-Haenszel statistics as weighting agent and magnitude of effect for the relative risk (RR) with its respective 95% confidence interval (95%CI). Higgins I 2 test was used to quantify the consistency between the results of each study. A total of 2,689 articles were evaluated, including 8 RCTs. There was a 27% reduction in angiographic restenosis (RR: 0.73, 95% CI: 0.54-0.97, I 2 = 51%) and statistically significant reduction in the rates of percutaneous revascularization and overall (RR: 0.88; 95% CI: 0.51 to 1.53, I 2 = 61%, RR: 0.73, 95% CI: 0.54 to 0.99, I 2 = 55%), with no statistical difference in surgical revascularization (RR: 0.95, 95% CI: 0.52-1.74, I 2 = 0%) in favor of IVUS vs. ANGIO. There were no differences regarding the other outcomes in the comparison between the two strategies. Angioplasty with stenting guided by IVUS decreases the rates of restenosis and revascularization, with no impact on MACE, acute myocardial infarction, mortality or thrombosis outcomes

  18. Stereotactic anatomical localization in complex sinus surgery: A systematic review and meta-analysis.

    Science.gov (United States)

    Vreugdenburg, Thomas D; Lambert, Robyn S; Atukorale, Yasoba N; Cameron, Alun L

    2016-01-01

    It is recognized that stereotactic anatomical localization (SAL) is a useful tool in endoscopic sinus surgery (ESS), but it may be most beneficial for complex rather than routine sinus procedures. This review sought to determine the safety and efficacy of SAL in complex indications for ESS. PubMed, EMBASE, Centre for Reviews and Dissemination, and the Cochrane Library were searched from inception up to April 4, 2014. English studies comparing ESS with and without SAL in complex cases were included. Complex surgery included revision surgery, inverted papilloma, extensive sinus disease, or biopsy of tumors that are not exophytic. Safety outcomes included total, major, minor, orbital, dural, and major hemorrhage complications. Efficacy outcomes included operation completion, revision surgery, and patient-reported outcomes. Meta-analysis generated fixed-effects Mantel-Haenszel odds ratios (OR) and confidence intervals (CI). A total of 2,381 studies were identified, of which nine met the inclusion criteria. Meta-analyses indicated a reduction in the likelihood of total (OR = 0.58; 95% CI, 0.37-0.92), major (OR = 0.36; 95% CI, 0.18-0.75), and orbital complications (OR = 0.38; 95% CI, 0.17-0.83). There was no demonstrated benefit of SAL at reducing revision surgery (OR = 0.64; 95% CI, 0.38-1.08), major hemorrhage (OR = 0.77; 95% CI, 0.29-2.06), or minor complications (OR = 0.85; 95% CI, 0.48-1.50). Due to the rare outcomes under investigation, the included primary studies largely lacked the power to identify a statistically meaningful effect of SAL in ESS. However, meta-analyses of primary studies demonstrated a decreased likelihood of total, major, and orbital complications in complex ESS with the use of SAL. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  19. Efficacy of ibuprofen on prevention of high altitude headache: A systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Juan Xiong

    Full Text Available Ibuprofen is used to prevent high altitude headache (HAH but its efficacy remains controversial. We conducted a systematic review and meta-analysis of randomized, placebo-controlled trials (RCTs of ibuprofen for the prevention of HAH.Studies reporting efficacy of ibuprofen for prevention of HAH were identified by searching electronic databases (until December 2016. The primary outcome was the difference in incidence of HAH between ibuprofen and placebo groups. Risk ratios (RR were aggregated using a Mantel-Haenszel random effect model. Heterogeneity of included trials was assessed using the I2 statistics.In three randomized-controlled clinical trials involving 407 subjects, HAH occurred in 101 of 239 subjects (42% who received ibuprofen and 96 of 168 (57% who received placebo (RR = 0.79, 95% CI 0.66 to 0.96, Z = 2.43, P = 0.02, I2 = 0%. The absolute risk reduction (ARR was 15%. Number needed to treat (NNT to prevent HAH was 7. Similarly, The incidence of severe HAH was significant in the two groups (RR = 0.40, 95% CI 0.17 to 0.93, Z = 2.14, P = 0.03, I2 = 0%. Severe HAH occurred in 3% treated with ibuprofen and 10% with placebo. The ARR was 8%. NNT to prevent severe HAH was 13. Headache severity using a visual analogue scale was not different between ibuprofen and placebo. Similarly, the difference between the two groups in the change in SpO2 from baseline to altitude was not different. One included RCT reported one participant with black stools and three participants with stomach pain in the ibuprofen group, while seven participants reported stomach pain in the placebo group.Based on a limited number of studies ibuprofen seems efficacious for the prevention of HAH and may therefore represent an alternative for preventing HAH with acetazolamide or dexamethasone.

  20. Misoprostol prior to hysteroscopy in premenopausal and post-menopausal women. A systematic review and meta-analysis.

    Science.gov (United States)

    Polyzos, N P; Zavos, A; Valachis, A; Dragamestianos, C; Blockeel, C; Stoop, D; Papanikolaou, E G; Tournaye, H; Devroey, P; Messinis, I E

    2012-07-01

    Although several randomized controlled trials (RCTs) have examined the effect of misoprostol prior to hysteroscopy for cervical dilatation, no solid conclusion has been reached. We therefore set out to perform a meta-analysis of RCTs. We searched MEDLINE, the ISI Web of Science and the Cochrane Library to identify RCTs comparing misoprostol versus placebo or control prior to hysteroscopy. No restrictions on language or time were applied. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated for all dichotomous outcomes, whereas mean differences (MDs) and 95% CIs were calculated for continuous outcomes using the Mantel-Haenszel or DerSimonian-Laird model according to the heterogeneity. Of the initial 141 potentially relevant articles that were retrieved, 21 RCTs involving 1786 patients were included in the meta-analysis. Subgroup analyses were performed according to menopausal status and according to whether diagnostic or operative hysteroscopy was performed. Premenopausal women treated with misoprostol had a significantly lower risk for further cervical dilatation in the diagnostic setting [RR (95% CI): 0.56 (0.34-0.92)] and a significantly lower risk for cervical laceration in the operative setting [RR (95% CI): 0.22 (0.09-0.54)], compared with placebo. In contrast, post-menopausal patients did not experience any clear benefit from misoprostol compared with placebo regarding the need for further cervical dilatation [RR (95% CI): 0.99 (0.76-1.30)] and the cervical laceration rate [RR (95% CI): 1.15 (0.40-3.29)]. In addition, the mean cervical width prior to hysteroscopy was significantly higher in premenopausal women treated with misoprostol compared with placebo [MD (95% CI): 2.47 mm (1.81-3.13)] but did not differ among post-menopausal patients [MD (95% CI): 0.39 mm (-0.42 to 1.21)]. Misoprostol prior to hysteroscopy appears to facilitate an easier and uncomplicated procedure only in premenopausal women.

  1. Cardiovascular safety of exenatide BID: an integrated analysis from controlled clinical trials in participants with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Yushmanova Irina

    2011-03-01

    Full Text Available Abstract It is important for patients that treatments for diabetes not increase cardiovascular (CV risk. The objective of this analysis was to examine retrospectively the CV safety of exenatide BID, a GLP-1 receptor agonist approved for treating hyperglycemia in patients with type 2 diabetes not adequately controlled with diet and exercise. Individual participant data was pooled to assess the relative risk (RR of CV events with exenatide BID versus a pooled comparator (PC group treated with either placebo or insulin from 12 controlled, randomized, clinical trials ranging from 12-52 weeks. Mean baseline values for HbA1c (8.33-8.38%, BMI (31.3-31.5 kg/m2, and duration of diabetes (8 y were similar between groups. Trials included patients with histories of microvascular and/or macrovascular disease. Customized primary major adverse CV events (MACE included stroke, myocardial infarction, cardiac mortality, acute coronary syndrome, and revascularization procedures. The Primary MACE RR (0.7; 95% CI 0.38, 1.31, calculated by the Mantel-Haenszel method (stratified by study, suggested that exenatide use (vs. PC did not increase CV risk; this result was consistent across multiple analytic methods. Because the trials were not designed to assess CV outcomes, events were identified retrospectively from a list of preferred terms by physicians blinded to treatment. Other limitations included the low number of CV events, the short duration of trials (≤1 y, and a single active comparator (insulin. The results of these analyses are consistent with those of a recent retrospective analysis of a large insurance database that found that patients treated with exenatide twice daily were less likely to have a CV event than were patients treated with other glucose-lowering therapies. Keywords: GLP-1 receptor agonist, diabetes, cardiovascular safety

  2. Circulating Vitamin D and Overall Survival in Breast Cancer Patients: A Dose-Response Meta-Analysis of Cohort Studies.

    Science.gov (United States)

    Hu, Kejia; Callen, David Frederick; Li, Jiayuan; Zheng, Hong

    2017-05-01

    Studies have shown that vitamin D could have a role in breast cancer survival; however, the evidence of the relationship between patients' vitamin D levels and their survival has been inconsistent. This meta-analysis explores possible dose-response relationships between vitamin D levels and overall survival by allowing for differences in vitamin D levels among populations of the various studies. Studies relating vitamin D (25-OH-D [25-hydroxyvitamin D]) levels in breast cancer patients with their survival were identified by searching PubMed and Embase. A pooled HR (hazard ratio) comparing the highest with the lowest category of circulating 25-OH-D levels were synthesized using the Mantel-Haenszel method under a fixed-effects model. A two-stage fixed-effects dose-response model including both linear (a log-linear dose-response regression) and nonlinear (a restricted cubic spline regression) models were used to further explore possible dose-response relationships. Six studies with a total number of 5984 patients were identified. A pooled HR comparing the highest with the lowest category of circulating 25-OH-D levels under a fixed-effects model was 0.67 (95% confidence interval = 0.56-0.79, P response meta-analysis, the pooled HR for overall survival in breast cancer patients was 0.994 (per 1 nmol/L), P for linear trend response relationship between circulating 25-OH-D levels and overall survival in patients with breast cancer. However, better designed prospective cohort studies and clinical trials are needed to further confirm these findings.

  3. Safety and efficacy of antibiotics compared with appendicectomy for treatment of uncomplicated acute appendicitis: meta-analysis of randomised controlled trials

    Science.gov (United States)

    Varadhan, Krishna K; Neal, Keith R

    2012-01-01

    Objective To compare the safety and efficacy of antibiotic treatment versus appendicectomy for the primary treatment of uncomplicated acute appendicitis. Design Meta-analysis of randomised controlled trials. Population Randomised controlled trials of adult patients presenting with uncomplicated acute appendicitis, diagnosed by haematological and radiological investigations. Interventions Antibiotic treatment versus appendicectomy. Outcome measures The primary outcome measure was complications. The secondary outcome measures were efficacy of treatment, length of stay, and incidence of complicated appendicitis and readmissions. Results Four randomised controlled trials with a total of 900 patients (470 antibiotic treatment, 430 appendicectomy) met the inclusion criteria. Antibiotic treatment was associated with a 63% (277/438) success rate at one year. Meta-analysis of complications showed a relative risk reduction of 31% for antibiotic treatment compared with appendicectomy (risk ratio (Mantel-Haenszel, fixed) 0.69 (95% confidence interval 0.54 to 0.89); I2=0%; P=0.004). A secondary analysis, excluding the study with crossover of patients between the two interventions after randomisation, showed a significant relative risk reduction of 39% for antibiotic therapy (risk ratio 0.61 (0.40 to 0.92); I2=0%; P=0.02). Of the 65 (20%) patients who had appendicectomy after readmission, nine had perforated appendicitis and four had gangrenous appendicitis. No significant differences were seen for treatment efficacy, length of stay, or risk of developing complicated appendicitis. Conclusion Antibiotics are both effective and safe as primary treatment for patients with uncomplicated acute appendicitis. Initial antibiotic treatment merits consideration as a primary treatment option for early uncomplicated appendicitis. PMID:22491789

  4. Bladder recovery by stem cell based cell therapy in the bladder dysfunction induced by spinal cord injury: systematic review and meta-analysis.

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    Jae Heon Kim

    Full Text Available Bladder dysfunction induced by spinal cord injury (SCI can become problematic and severely impair the quality of life. Preclinical studies of spinal cord injury have largely focused on the recovery of limb function while neglecting to investigate bladder recovery.The present study was performed to investigate and review the effect of stem cell-based cell therapy on bladder recovery in SCI.We conducted a meta-analysis of urodynamic findings of experimental trials that included studies of stem cell-based cell therapy in SCI. Relevant studies were searched using MEDLINE, EMBASE and Cochrane Library (January 1990 - December 2012. Final inclusion was determined by a urodynamic study involving detailed numerical values. Urodynamic parameters for analysis included voiding pressure, residual urine, bladder capacity and non-voiding contraction (NVC. Meta-analysis of the data, including findings from urodynamic studies, was performed using the Mantel-Haenszel method.A total of eight studies were included with a sample size of 224 subjects. The studies were divided into different subgroups by different models of SCI. After a stem cell-based cell therapy, voiding pressure (-6.35, p <0.00001, I2 = 77%, NVC (-3.58, p <0.00001, I2 = 82%, residual urine (-024, p = 0.004, I2 = 95% showed overall significant improvement. Bladder capacity showed improvement after treatment only in the transection type (-0.23, p = 0.0002, I2 = 0%.After stem cell-based cell therapy in SCI, partial bladder recovery including improvement of voiding pressure, NVC, and residual urine was demonstrated. Additional studies are needed to confirm the detailed mechanism and to obtain an ideal treatment strategy for bladder recovery.

  5. Tidal volume and mortality in mechanically ventilated children: a systematic review and meta-analysis of observational studies*.

    Science.gov (United States)

    de Jager, Pauline; Burgerhof, Johannes G M; van Heerde, Marc; Albers, Marcel J I J; Markhorst, Dick G; Kneyber, Martin C J

    2014-12-01

    To determine whether tidal volume is associated with mortality in critically ill, mechanically ventilated children. MEDLINE, EMBASE, and CINAHL databases from inception until July 2013 and bibliographies of included studies without language restrictions. Randomized clinical trials and observational studies reporting mortality in mechanically ventilated PICU patients. Two authors independently selected studies and extracted data on study methodology, quality, and patient outcomes. Meta-analyses were performed using the Mantel-Haenszel random-effects model. Heterogeneity was quantified using I. Study quality was assessed using the Newcastle-Ottawa Score for cohort studies. Out of 142 citations, seven studies met the inclusion criteria, and additional two articles were identified from references of the found articles. One was excluded. These eight studies included 1,756 patients. Mortality rates ranged from 13% to 42%. There was no association between tidal volume and mortality when tidal volume was dichotomized at 7, 8, 10, or 12 mL/kg. Comparing patients ventilated with tidal volume less than 7 mL/kg and greater than 10 mL/kg or greater than 12 mL/kg and tidal volume less than 8 mL/kg and greater than 10 mL/kg or greater than 12 mL/kg also showed no association between tidal volume and mortality. Limiting the analysis to patients with acute lung injury/acute respiratory distress syndrome did not change these results. Heterogeneity was observed in all pooled analyses. A relationship between tidal volume and mortality in mechanically ventilated children could not be identified, irrespective of the severity of disease. The significant heterogeneity observed in the pooled analyses necessitates future studies in well-defined patient populations to understand the effects of tidal volume on patient outcome.

  6. Clinical and Echocardiographic Outcomes Following Permanent Pacemaker Implantation After Transcatheter Aortic Valve Replacement: Meta-Analysis and Meta-Regression.

    Science.gov (United States)

    Mohananey, Divyanshu; Jobanputra, Yash; Kumar, Arnav; Krishnaswamy, Amar; Mick, Stephanie; White, Jonathon M; Kapadia, Samir R

    2017-07-01

    Transcatheter aortic valve replacement has become the procedure of choice for inoperable, high-risk, and many intermediate-risk patients with aortic stenosis. Conduction abnormalities are a common finding after transcatheter aortic valve replacement and often result in permanent pacemaker (PPM) implantation. Data pertaining to the clinical impact of PPM implantation are controversial. We used meta-analysis techniques to summarize the effect of PPM implantation on clinical and echocardiographic outcomes after transcatheter aortic valve replacement. Data were summarized as Mantel-Haenszel relative risk (RR) and 95% confidence intervals (CIs) for dichotomous variables and as standardized mean difference and 95% CI for continuous variables We used the Higgins I 2 statistic to evaluate heterogeneity. We found that patients with and without PPM have similar all-cause mortality (RR, 0.85; 95% CI, 0.70-1.03), cardiovascular mortality (RR, 0.84; 95% CI, 0.59-1.18), myocardial infarction (RR, 0.47; 95% CI, 0.20-1.11), and stroke (RR, 1.26; 95% CI, 0.70-2.26) at 30 days. The groups were also comparable in all-cause mortality (RR, 1.03; 95% CI, 0.92-1.16), cardiovascular mortality (RR, 0.69; 95% CI, 0.39-1.24), myocardial infarction (RR, 0.58; 95% CI, 0.30-1.13), and stroke (RR, 0.70; 95% CI, 0.47-1.04) at 1 year. We observed that the improvement in left ventricular ejection fraction was significantly greater in the patients without PPM (standardized mean difference, 0.22; 95% CI, 0.12-0.32). PPM implantation is not associated with increased risk of all-cause mortality, cardiovascular mortality, stroke, or myocardial infarction both at short- and long-term follow-up. However, PPM is associated with impaired left ventricular ejection fraction recovery post-transcatheter aortic valve replacement. © 2017 American Heart Association, Inc.

  7. Efficacy and safety of solifenacin plus tamsulosin oral controlled absorption system in men with lower urinary tract symptoms: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Ming-Chao Li

    2015-02-01

    Full Text Available We performed a meta-analysis to compare treatment with a combination of solifenacin plus tamsulosin oral controlled absorption system (TOCAS with placebo or TOCAS monotherapy. The aim of the meta-analysis was to clarify the efficacy and safety of the combination treatments method for lower urinary tract symptoms (LUTS. We searched for trials of men with LUTS that were randomized to combination treatment compared with TOCAS monotherapy or placebo. We pooled data from three placebo-controlled trials meeting inclusion criteria. Primary outcomes of interest included changes in International Prostate Symptom Score (IPSS and urinary frequency. We also assessed postvoid residual, maximum urinary flow rate, incidence of urinary retention (UR, adverse events. Data were pooled using random or fixed effect models for continuous outcomes and the Mantel-Haenszel method to generate risk ratio. Reductions in IPSS storage subscore and total urgency and frequency score (TUFS were observed with solifenacin 6 mg plus TOCAS compared with placebo (P< 0.0001 and P< 0.0001, respectively. Reductions in IPSS storage subscore and TUFS were observed with solifenacin 9 mg plus TOCAS compared with placebo (P = 0.003 and P= 0.0006, respectively. Reductions in TUFS was observed with solifenacin 6 mg plus TOCAS compared with TOCAS (P = 0.01. Both combination treatments were well tolerated, with low incidence of UR. Solifenacin 6 mg plus TOCAS significantly improved total IPSS, storage and voiding symptoms compared with placebo. Solifenacin 6 mg plus TOCAS also improved storage symptoms compared with TOCAS alone. There was no additional benefit of solifenacin 9 mg compared with 6 mg when used in combination with TOCAS.

  8. Risk of wound infection and safety profile of amoxicillin in healthy patients which required third molar surgery: a systematic review and meta-analysis.

    Science.gov (United States)

    Isiordia-Espinoza, M A; Aragon-Martinez, O H; Martínez-Morales, J F; Zapata-Morales, J R

    2015-11-01

    The aim of this systematic review and meta-analysis was to assess the risk of surgical wound infection and the adverse effects of amoxicillin in healthy patients who required excision of third molars. We identified eligible reports from searches of PubMed, Medline®, the Cochrane Library, Imbiomed, LILACS, and Google Scholar. Studies that met our minimum requirements were evaluated using inclusion and exclusion criteria and the Oxford Quality Scale. Those with a score of 3 or more on this Scale were included and their data were extracted and analysed. For evaluation of the risk of infection the absolute risk reduction, number needed to treat, and 95% CI were calculated. For evaluation of the risk of an adverse effect the absolute risk increase, number needed to harm, and 95% CI were calculated using the Risk Reduction Calculator. Each meta-analysis was made with the help of the Mantel-Haenszel random effects model, and estimates of risk (OR) and 95% CI were calculated using the Review Manager 5.3, from the Cochrane Library. A significant risk was assumed when the lower limit of the 95% CI was greater than 1. Probabilities of less than 0.05 were accepted as significant. The results showed that there was no reduction in the risk of infection when amoxicillin was given before or after operation compared with an untreated group or placebo. In conclusion, this study suggests that amoxicillin given prophylactically or postoperatively does not reduce the risk of infection in healthy patients having their third molars extracted. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  9. Risks of cardiovascular or central nervous system adverse events and immune reconstitution inflammatory syndrome, for dolutegravir versus other antiretrovirals: meta-analysis of randomized trials.

    Science.gov (United States)

    Hill, Andrew M; Mitchell, Nikkita; Hughes, Sophie; Pozniak, Anton L

    2018-03-01

    Results from nonrandomized cohort studies suggest higher risks of CNS adverse events for dolutegravir, versus other ARVs. There have been two case reports of myocarditis on dolutegravir. Integrase inhibitors have been associated with IRIS in two cohort studies. Meta-analysis of randomized trials can be used to cross-check potential safety signals. This systematic review of drug safety used an EMBASE and MEDLINE search combined with serious adverse event (SAE) reports on the website www.clinicaltrials.gov. Cardiovascular, CNS or IRIS-associated adverse events were analysed for dolutegravir versus other ARVs. Relative risks for the comparison between dolutegravir and other antiretrovirals were calculated for each adverse event. Meta-analyses applied Mantel-Haenszel random-effects models. There was a higher risk of Grade 1-4 insomnia adverse events for DTG (6.1%) versus other ARVs (4.5%; P = 0.02). There was no significant difference between DTG and other ARVs in the risk of cardiovascular serious adverse events. In the SINGLE and SPRING-1 trials comparing DTG with efavirenz, there were 5/465 patients with reported suicidality SAEs on DTG (1.1%) versus 6/469 (1.3%) on EFV. In other studies, serious adverse events of suicidality were reported for 15/2250 patients on DTG (0.7%) versus 9/2257 patients on other ARVs (0.4%). Risks of IRIS were low, but event rates were low and the main trials excluded CDC stage C disease. In this meta-analysis, there was no significant effect of dolutegravir on the risk of cardiac, IRIS or suicide-related serious adverse events. There was a higher risk of insomnia for DTG. Other completed randomized trials should be included in new evaluations of DTG safety. Continued pharmacovigilance, with regular meta-analyses, should be used to monitor safety.

  10. Accuracy of Lung Ultrasonography versus Chest Radiography for the Diagnosis of Adult Community-Acquired Pneumonia: Review of the Literature and Meta-Analysis.

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    Xiong Ye

    Full Text Available Lung ultrasonography (LUS is being increasingly utilized in emergency and critical settings. We performed a systematic review of the current literature to compare the accuracy of LUS and chest radiography (CR for the diagnosis of adult community-acquired pneumonia (CAP. We searched in Pub Med, EMBASE dealing with both LUS and CR for diagnosis of adult CAP, and conducted a meta-analysis to evaluate the diagnostic accuracy of LUS in comparison with CR. The diagnostic standard that the index test compared was the hospital discharge diagnosis or the result of chest computed tomography scan as a "gold standard". We calculated pooled sensitivity and specificity using the Mantel-Haenszel method and pooled diagnostic odds ratio using the DerSimonian-Laird method. Five articles met our inclusion criteria and were included in the final analysis. Using hospital discharge diagnosis as reference, LUS had a pooled sensitivity of 0.95 (0.93-0.97 and a specificity of 0.90 (0.86 to 0.94, CR had a pooled sensitivity of 0.77 (0.73 to 0.80 and a specificity of 0.91 (0.87 to 0.94. LUS and CR compared with computed tomography scan in 138 patients in total, the Z statistic of the two summary receiver operating characteristic was 3.093 (P = 0.002, the areas under the curve for LUS and CR were 0.901 and 0.590, respectively. Our study indicates that LUS can help to diagnosis adult CAP by clinicians and the accuracy was better compared with CR using chest computed tomography scan as the gold standard.

  11. Is there an increased risk of post-operative surgical site infection after orthopaedic surgery in HIV patients? A systematic review and meta-analysis.

    Science.gov (United States)

    Kigera, James W M; Straetemans, Masja; Vuhaka, Simplice K; Nagel, Ingeborg M; Naddumba, Edward K; Boer, Kimberly

    2012-01-01

    There is dilemma as to whether patients infected with the Human Immunodeficiency Virus (HIV) requiring implant orthopaedic surgery are at an increased risk for post-operative surgical site infection (SSI). We conducted a systematic review to determine the effect of HIV on the risk of post-operative SSI and sought to determine if this risk is altered by antibiotic use beyond 24 hours. We searched electronic databases, manually searched citations from relevant articles, and reviewed conference proceedings. The risk of postoperative SSI was pooled using Mantel-Haenszel method. We identified 18 cohort studies with 16 mainly small studies, addressing the subject. The pooled risk ratio of infection in the HIV patients when compared to non-HIV patients was 1.8 (95% Confidence Interval [CI] 1.3-2.4), in studies in Africa this was 2.3 (95% CI 1.5-3.5). In a sensitivity analysis the risk ratio was reduced to 1.4 (95% CI 0.5-3.8). The risk ratio of infection in patients receiving prolonged antibiotics compared to patients receiving antibiotics for up to 24 hours was 0.7 (95% CI 0.1-4.2). The results may indicate an increased risk in HIV infected patients but these results are not robust and inconclusive after conducting the sensitivity analysis removing poor quality studies. There is need for larger good quality studies to provide conclusive evidence. To better develop surgical protocols, further studies should determine the effect of reduced CD4 counts, viral load suppression and prolonged antibiotics on the risk for infection.

  12. Systematic review and meta-analysis of the effectiveness of commercially available vaccines against bovine herpesvirus, bovine viral diarrhea virus, bovine respiratory syncytial virus, and parainfluenza type 3 virus for mitigation of bovine respiratory disease complex in cattle.

    Science.gov (United States)

    Theurer, Miles E; Larson, Robert L; White, Brad J

    2015-01-01

    To evaluate and analyze data from controlled studies on the effectiveness of vaccinating cattle with commercially available viral antigen vaccines for mitigation of the effects of bovine respiratory disease complex (BRDC). Systematic review and meta-analysis. 31 studies comprising 88 trials. Studies that reported the effectiveness of commercially available bovine herpesvirus-1 (BHV-1), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), and parainfluenza type 3 virus (PI3) vaccines for protection of cattle against BRDC or its components were included in the analysis. Studies or trials were categorized as natural exposure or experimental challenge and were further divided by the viral antigen evaluated and vaccine type (modified-live virus [MLV] or inactivated vaccine). Meta-analysis was performed; summary Mantel-Haenszel risk ratios were determined, and Forest plots were generated. In natural exposure trials, beef calves vaccinated with various antigen combinations had a significantly lower BRDC morbidity risk than did nonvaccinated control calves. In trials evaluating BHV-1 and MLV BVDV vaccines in experimental challenge models, vaccinated calves had a lower BRDC morbidity risk than did control calves; however, in experimental challenge trials evaluating MLV BRSV and PI3 vaccines, no significant difference in morbidity or mortality risk was found between vaccinated and control calves. Estimating clinical efficacy from results of experimental challenge studies requires caution because these models differ substantially from those involving natural exposure. The literature provides data but does not provide sufficiently strong evidence to guide definitive recommendations for determining which virus components are necessary to include in a vaccination program for prevention or mitigation of BRDC in cattle.

  13. Residual Analysis of Generalized Autoregressive Integrated Moving ...

    African Journals Online (AJOL)

    In this study, analysis of residuals of generalized autoregressive integrated moving average bilinear time series model was considered. The adequacy of this model was based on testing the estimated residuals for whiteness. Jarque-Bera statistic and squared-residual autocorrelations were used to test the estimated ...

  14. Texture analysis using Renyi's generalized entropies

    NARCIS (Netherlands)

    Grigorescu, SE; Petkov, N

    2003-01-01

    We propose a texture analysis method based on Renyi's generalized entropies. The method aims at identifying texels in regular textures by searching for the smallest window through which the minimum number of different visual patterns is observed when moving the window over a given texture. The

  15. The status of rheumatoid factor and anti-cyclic citrullinated peptide antibody are not associated with the effect of anti-TNFα agent treatment in patients with rheumatoid arthritis: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Qianwen Lv

    Full Text Available OBJECTIVES: This meta-analysis was conducted to investigate whether the status of rheumatoid factor (RF and anti-cyclic citrullinated peptide (anti-CCP antibody are associated with the clinical response to anti-tumor necrosis factor (TNF alpha treatment in rheumatoid arthritis (RA. METHODS: A systemic literature review was performed using the MEDLINE, SCOPUS, Cochrane Library, ISI Web of Knowledge, and Clinical Trials Register databases, and Hayden's criteria of quality assessment for prognostic studies were used to evaluate all of the studies. The correlation between the RF and anti-CCP antibody status with the treatment effect of anti-TNFα agents was analyzed separately using the Mantel Haenszel method. A fixed-effects model was used when there was no significant heterogeneity; otherwise, a random-effects model was applied. Publication bias was assessed using Egger's linear regression and a funnel plot. RESULTS: A total of 14 studies involving 5561 RA patients meeting the inclusion criteria were included. The overall analysis showed that the pooled relative risk for the predictive effects of the RF and anti-CCP antibody status on patient response to anti-TNFα agents was 0.98 (95% CI: 0.91-1.05, p=0.54 and 0.88 (95% CI: 0.76-1.03, p=0.11, respectively, with I(2 values of 43% (p=0.05 and 67% (p<0.01, respectively. Subgroup analyses of different anti-TNFα treatments (infliximab vs. etanercept vs. adalimumab vs. golimumab, response criteria (DAS28 vs. ACR20 vs. EULAR response, follow-up period (≥ 6 vs. <6 months, and ethnic group did not reveal a significant association for the status of RF and anti-CCP. CONCLUSIONS: Neither the RF nor anti-CCP antibody status in RA patients is associated with a clinical response to anti-TNFα treatment.

  16. Clinical impact of implantable cardioverter-defibrillator in primary prevention of total mortality in non-ischaemic cardiomyopathy: results from a meta-analysis of prospective randomized clinical trials.

    Science.gov (United States)

    Romero, Jorge; Díaz, Juan Carlos; Grushko, Michael; Quispe, Renato; Briceno, David; Avendano, Ricardo; Golive, Anjani; Pina, Ileana; Natale, Andrea; Garcia, Mario J; Jorde, Ulrich P; Di Biase, Luigi

    2017-11-17

    Primary prophylactic implantable cardioverter defibrillators (ICDs) have demonstrated a clear all-cause mortality benefit in patients with ischaemic cardiomyopathy, with less compelling evidence supporting its use in patients with non-ischaemic cardiomyopathy (NICM). We performed a meta-analysis of randomized controlled trials (RCTs) evaluating the role of ICD for reduction in total mortality in NICM patients. An electronic search on PubMed, the Cochrane Library, and EMBASE databases was performed to identify the RCTs evaluating the role of prophylactic ICD placement in NICM patients. Mantel-Haenszel risk ratio (RR) fixed-effects model was used to summarize data across treatment arms. Random-effects model was used if heterogeneity (I2) ≥ 25. Patients with cardiac resynchronization therapy pacemaker (CRT-P) were included in the control group. Six RCTs, with a total of 3128 patients and a mean follow-up period of 48 ± 22 months comparing ICD with medical therapy in NICM were included in this analysis. There was a significant reduction in all-cause mortality in the ICD group compared with the medical therapy group [RR 0.79, 95% confidence interval (95% CI) 0.68-0.92; P = 0.002]. No publication bias was noted. Currently available evidence demonstrates that the use of ICD provides a clear and significant reduction in all-cause mortality among patients with NICM. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

  17. Functional data analysis of generalized regression quantiles

    KAUST Repository

    Guo, Mengmeng

    2013-11-05

    Generalized regression quantiles, including the conditional quantiles and expectiles as special cases, are useful alternatives to the conditional means for characterizing a conditional distribution, especially when the interest lies in the tails. We develop a functional data analysis approach to jointly estimate a family of generalized regression quantiles. Our approach assumes that the generalized regression quantiles share some common features that can be summarized by a small number of principal component functions. The principal component functions are modeled as splines and are estimated by minimizing a penalized asymmetric loss measure. An iterative least asymmetrically weighted squares algorithm is developed for computation. While separate estimation of individual generalized regression quantiles usually suffers from large variability due to lack of sufficient data, by borrowing strength across data sets, our joint estimation approach significantly improves the estimation efficiency, which is demonstrated in a simulation study. The proposed method is applied to data from 159 weather stations in China to obtain the generalized quantile curves of the volatility of the temperature at these stations. © 2013 Springer Science+Business Media New York.

  18. Generalized Analysis of a Distribution Separation Method

    Directory of Open Access Journals (Sweden)

    Peng Zhang

    2016-04-01

    Full Text Available Separating two probability distributions from a mixture model that is made up of the combinations of the two is essential to a wide range of applications. For example, in information retrieval (IR, there often exists a mixture distribution consisting of a relevance distribution that we need to estimate and an irrelevance distribution that we hope to get rid of. Recently, a distribution separation method (DSM was proposed to approximate the relevance distribution, by separating a seed irrelevance distribution from the mixture distribution. It was successfully applied to an IR task, namely pseudo-relevance feedback (PRF, where the query expansion model is often a mixture term distribution. Although initially developed in the context of IR, DSM is indeed a general mathematical formulation for probability distribution separation. Thus, it is important to further generalize its basic analysis and to explore its connections to other related methods. In this article, we first extend DSM’s theoretical analysis, which was originally based on the Pearson correlation coefficient, to entropy-related measures, including the KL-divergence (Kullback–Leibler divergence, the symmetrized KL-divergence and the JS-divergence (Jensen–Shannon divergence. Second, we investigate the distribution separation idea in a well-known method, namely the mixture model feedback (MMF approach. We prove that MMF also complies with the linear combination assumption, and then, DSM’s linear separation algorithm can largely simplify the EM algorithm in MMF. These theoretical analyses, as well as further empirical evaluation results demonstrate the advantages of our DSM approach.

  19. Contributions to sensitivity analysis and generalized discriminant analysis

    International Nuclear Information System (INIS)

    Jacques, J.

    2005-12-01

    Two topics are studied in this thesis: sensitivity analysis and generalized discriminant analysis. Global sensitivity analysis of a mathematical model studies how the output variables of this last react to variations of its inputs. The methods based on the study of the variance quantify the part of variance of the response of the model due to each input variable and each subset of input variables. The first subject of this thesis is the impact of a model uncertainty on results of a sensitivity analysis. Two particular forms of uncertainty are studied: that due to a change of the model of reference, and that due to the use of a simplified model with the place of the model of reference. A second problem was studied during this thesis, that of models with correlated inputs. Indeed, classical sensitivity indices not having significance (from an interpretation point of view) in the presence of correlation of the inputs, we propose a multidimensional approach consisting in expressing the sensitivity of the output of the model to groups of correlated variables. Applications in the field of nuclear engineering illustrate this work. Generalized discriminant analysis consists in classifying the individuals of a test sample in groups, by using information contained in a training sample, when these two samples do not come from the same population. This work extends existing methods in a Gaussian context to the case of binary data. An application in public health illustrates the utility of generalized discrimination models thus defined. (author)

  20. Bisphosphonates and risk of cardiovascular events: a meta-analysis.

    Science.gov (United States)

    Kim, Dae Hyun; Rogers, James R; Fulchino, Lisa A; Kim, Caroline A; Solomon, Daniel H; Kim, Seoyoung C

    2015-01-01

    Some evidence suggests that bisphosphonates may reduce atherosclerosis, while concerns have been raised about atrial fibrillation. We conducted a meta-analysis to determine the effects of bisphosphonates on total adverse cardiovascular (CV) events, atrial fibrillation, myocardial infarction (MI), stroke, and CV death in adults with or at risk for low bone mass. A systematic search of MEDLINE and EMBASE through July 2014 identified 58 randomized controlled trials with longer than 6 months in duration that reported CV events. Absolute risks and the Mantel-Haenszel fixed-effects odds ratios (ORs) and 95% confidence intervals (CIs) of total CV events, atrial fibrillation, MI, stroke, and CV death were estimated. Subgroup analyses by follow-up duration, population characteristics, bisphosphonate types, and route were performed. Absolute risks over 25-36 months in bisphosphonate-treated versus control patients were 6.5% versus 6.2% for total CV events; 1.4% versus 1.5% for atrial fibrillation; 1.0% versus 1.2% for MI; 1.6% versus 1.9% for stroke; and 1.5% versus 1.4% for CV death. Bisphosphonate treatment up to 36 months did not have any significant effects on total CV events (14 trials; ORs [95% CI]: 0.98 [0.84-1.14]; I2 = 0.0%), atrial fibrillation (41 trials; 1.08 [0.92-1.25]; I2 = 0.0%), MI (10 trials; 0.96 [0.69-1.34]; I2 = 0.0%), stroke (10 trials; 0.99 [0.82-1.19]; I2 = 5.8%), and CV death (14 trials; 0.88 [0.72-1.07]; I2 = 0.0%) with little between-study heterogeneity. The risk of atrial fibrillation appears to be modestly elevated for zoledronic acid (6 trials; 1.24 [0.96-1.61]; I2 = 0.0%), not for oral bisphosphonates (26 trials; 1.02 [0.83-1.24]; I2 = 0.0%). The CV effects did not vary by subgroups or study quality. Bisphosphonates do not have beneficial or harmful effects on atherosclerotic CV events, but zoledronic acid may modestly increase the risk of atrial fibrillation. Given the large reduction in fractures with bisphosphonates, changes in osteoporosis

  1. Toward General Analysis of Recursive Probability Models

    OpenAIRE

    Pless, Daniel; Luger, George

    2013-01-01

    There is increasing interest within the research community in the design and use of recursive probability models. Although there still remains concern about computational complexity costs and the fact that computing exact solutions can be intractable for many nonrecursive models and impossible in the general case for recursive problems, several research groups are actively developing computational techniques for recursive stochastic languages. We have developed an extension to the traditional...

  2. Generalized Path Analysis and Generalized Simultaneous Equations Model for Recursive Systems with Responses of Mixed Types

    Science.gov (United States)

    Tsai, Tien-Lung; Shau, Wen-Yi; Hu, Fu-Chang

    2006-01-01

    This article generalizes linear path analysis (PA) and simultaneous equations models (SiEM) to deal with mixed responses of different types in a recursive or triangular system. An efficient instrumental variable (IV) method for estimating the structural coefficients of a 2-equation partially recursive generalized path analysis (GPA) model and…

  3. GPSAP: general purpose systems analysis preprocessor

    Energy Technology Data Exchange (ETDEWEB)

    Geyer, H. K.; Sacks, R. A.

    1979-05-01

    GPSAP is designed to allow users with little computer experience to carry out complex numerical systems analysis studies quickly and easily. Given a set of precompiled subroutines modeling the behavior of the components and a brief structure describing the way in which these components are linked and/or constrained, the preprocessor constructs a main program to carry out the analysis. The use of a preprocessor approach, coupled with symbolic code words for the standard system-analytic procedures (e.g., vary model parameters, perform parameter sweeps, study sensitivity or constrained optimization, store or retrieve data from file memory), yields great flexibility while maintaining simplicity in both the GPSAP code itself and the input structures used to invoke it. The code was developed over a period of time for the analysis of various types of problems in MHD channel design.

  4. Transparent polyurethane film as an intravenous catheter dressing. A meta-analysis of the infection risks.

    Science.gov (United States)

    Hoffmann, K K; Weber, D J; Samsa, G P; Rutala, W A

    1992-04-15

    To obtain a quantitative estimate of the impact on infectious complications of using transparent dressings with intravenous catheters. Meta-analysis of all studies published in the English literature, including abstracts, letters, and reports that examined the primary research question of infection risks associated with transparent compared with gauze dressings for use on central and peripheral venous catheters. Studies were identified by use of the MEDLINE database using the indexing terms occlusive dressings, transparent dressings, and infection and by review of referenced bibliographies. Seven of the 15 studies (47%) of central venous catheters and seven of 12 studies (58%) of peripheral catheters met our inclusion criteria for analysis. All studies used a prospective cohort design, utilized hospitalized patients, and reported at least one of our defined outcomes. Data for each study were abstracted independently by three investigators. At least three studies were used in the analysis of each outcome. Applying a Mantel-Haenszel chi 2 analysis, use of transparent dressings on central venous catheters was significantly associated with an elevated relative risk (RR) of catheter tip infection (RR = 1.78; 95% confidence interval [CI], 1.38 to 2.30). Catheter-related sepsis (RR = 1.69; 95% CI, 0.97 to 2.95) and bacteremia (RR = 1.63; 95% CI, 0.76 to 3.47) were both associated with an elevated RR. Use of transparent dressings on peripheral catheters was associated with an elevated RR of catheter-tip infection (RR = 1.53; 95% CI, 1.18 to 1.99) but not phlebitis (RR = 1.02; 95% CI, 0.86 to 1.20), infiltration (RR = 1.12; 95% CI, 0.92 to 1.37), or skin colonization (RR = 0.99; 95% CI, 0.90 to 1.09). The results demonstrated a significantly increased risk of catheter-tip infection with the use of transparent compared with gauze dressings when used with either central or peripheral catheters. An increased risk of bacteremia and catheter sepsis associated with the use of

  5. A Computable General Equilibrium Microsimulation Analysis

    African Journals Online (AJOL)

    Daniel

    3 The UNDP (2010) introduced MPI for the first time to complement money-based measures by considering multiple .... assumptions of neoclassical theory, lack of sensitivity analysis, validity of predictions for policy etc. ..... tax rates are exogenous and it is the changes in government savings that equilibrate the economy.

  6. Weighted analysis of general microarray experiments

    Directory of Open Access Journals (Sweden)

    Kristiansson Erik

    2007-10-01

    Full Text Available Abstract Background In DNA microarray experiments, measurements from different biological samples are often assumed to be independent and to have identical variance. For many datasets these assumptions have been shown to be invalid and typically lead to too optimistic p-values. A method called WAME has been proposed where a variance is estimated for each sample and a covariance is estimated for each pair of samples. The current version of WAME is, however, limited to experiments with paired design, e.g. two-channel microarrays. Results The WAME procedure is extended to general microarray experiments, making it capable of handling both one- and two-channel datasets. Two public one-channel datasets are analysed and WAME detects both unequal variances and correlations. WAME is compared to other common methods: fold-change ranking, ordinary linear model with t-tests, LIMMA and weighted LIMMA. The p-value distributions are shown to differ greatly between the examined methods. In a resampling-based simulation study, the p-values generated by WAME are found to be substantially more correct than the alternatives when a relatively small proportion of the genes is regulated. WAME is also shown to have higher power than the other methods. WAME is available as an R-package. Conclusion The WAME procedure is generalized and the limitation to paired-design microarray datasets is removed. The examined other methods produce invalid p-values in many cases, while WAME is shown to produce essentially valid p-values when a relatively small proportion of genes is regulated. WAME is also shown to have higher power than the examined alternative methods.

  7. Hyoscine for polyp detection during colonoscopy: A meta-analysis and systematic review.

    Science.gov (United States)

    Ashraf, Imran; Ashraf, Sohail; Siddique, Sameer; Nguyen, Douglas L; Choudhary, Abhishek; Bechtold, Matthew L

    2014-11-16

    To assess the role of hyoscine for polyp detection during colonoscopy. Studies (randomized controlled trials or RCTs) that compared the use of hyoscine vs no hyoscine or placebo for polyp detection during colonoscopy were included in our analysis. A search on multiple databases was performed in September 2013 with search terms being "hyoscine and colonoscopy", "hyoscine and polyp", "hyoscine and adenoma", "antispasmotic and colonoscopy", "antispasmotic and adenoma", and "antispasmotic and polyp". Jadad scoring was used to assess the quality of studies. The efficacy of hyoscine was analyzed using Mantel-Haenszel model for polyp and adenoma detection with odds ratio (OR). The I (2) measure of inconsistency was used to assess heterogeneity (P 50%). Statistical analysis was performed by RevMan 5.1. Funnel plots was used to assess publication bias. The search of the electronic databases identified 283 articles. Of these articles, eight published RCTs performed at various locations in Europe, Asia, and Australia were included in our meta-analysis, seven published as manuscripts and one published as an abstract (n = 2307). All the studies included patients with a hyoscine and a no hyoscine/placebo group and were of adequate quality (Jadad score ≥ 2). Eight RCTs assessed the polyp detection rate (PDR) (n = 2307). The use of hyoscine demonstrated no statistically significant difference as compared to no hyoscine or placebo for PDR (OR = 1.06; 95%CI: 0.89-1.25; P = 0.51). Five RCTs assessed the adenoma detection rate (ADR) (n = 2015). The use of hyoscine demonstrated no statistically significant difference as compared to no hyoscine or placebo for ADR (OR = 1.12; 95%CI: 0.92-1.37; P = 0.25). Furthermore, the timing of hyoscine administration (given at cecal intubation or pre-procedure) demonstrated no differences in PDR compared to no hyoscine or placebo. Publication bias or heterogeneity was not observed for any of the outcomes. Hyoscine use in patients undergoing

  8. Generalized Fluid System Simulation Program (GFSSP) Version 6 - General Purpose Thermo-Fluid Network Analysis Software

    Science.gov (United States)

    Majumdar, Alok; Leclair, Andre; Moore, Ric; Schallhorn, Paul

    2011-01-01

    GFSSP stands for Generalized Fluid System Simulation Program. It is a general-purpose computer program to compute pressure, temperature and flow distribution in a flow network. GFSSP calculates pressure, temperature, and concentrations at nodes and calculates flow rates through branches. It was primarily developed to analyze Internal Flow Analysis of a Turbopump Transient Flow Analysis of a Propulsion System. GFSSP development started in 1994 with an objective to provide a generalized and easy to use flow analysis tool for thermo-fluid systems.

  9. A genome wide meta-analysis study for identification of common variation associated with breast cancer prognosis.

    Directory of Open Access Journals (Sweden)

    Sajjad Rafiq

    Full Text Available Genome wide association studies (GWAs of breast cancer mortality have identified few potential associations. The concordance between these studies is unclear. In this study, we used a meta-analysis of two prognostic GWAs and a replication cohort to identify the strongest associations and to evaluate the loci suggested in previous studies. We attempt to identify those SNPs which could impact overall survival irrespective of the age of onset.To facilitate the meta-analysis and to refine the association signals, SNPs were imputed using data from the 1000 genomes project. Cox-proportional hazard models were used to estimate hazard ratios (HR in 536 patients from the POSH cohort (Prospective study of Outcomes in Sporadic versus Hereditary breast cancer and 805 patients from the HEBCS cohort (Helsinki Breast Cancer Study. These hazard ratios were combined using a Mantel-Haenszel fixed effects meta-analysis and a p-value threshold of 5×10(-8 was used to determine significance. Replication was performed in 1523 additional patients from the POSH study.Although no SNPs achieved genome wide significance, three SNPs have significant association in the replication cohort and combined p-values less than 5.6×10(-6. These SNPs are; rs421379 which is 556 kb upstream of ARRDC3 (HR = 1.49, 95% confidence interval (CI = 1.27-1.75, P = 1.1×10(-6, rs12358475 which is between ECHDC3 and PROSER2 (HR = 0.75, CI = 0.67-0.85, P = 1.8×10(-6, and rs1728400 which is between LINC00917 and FOXF1.In a genome wide meta-analysis of two independent cohorts from UK and Finland, we identified potential associations at three distinct loci. Phenotypic heterogeneity and relatively small sample sizes may explain the lack of genome wide significant findings. However, the replication at three SNPs in the validation cohort shows promise for future studies in larger cohorts. We did not find strong evidence for concordance between the few associations highlighted

  10. Oral versus intravenous methylprednisolone for the treatment of multiple sclerosis relapses: A meta-analysis of randomized controlled trials.

    Directory of Open Access Journals (Sweden)

    Shuo Liu

    Full Text Available Intravenous glucocorticoids are recommended for multiple sclerosis (MS. However, they can be inconvenient and expensive. Due to their convenience and low cost, oral glucocorticoids may be an alternative treatment. Recently, several studies have shown that there is no difference in efficacy and safety between oral methylprednisolone (oMP and intravenous methylprednisolone (ivMP.We sought to assess the clinical efficacy, safety and tolerability of oral methylprednisolone versus intravenous methylprednisolone for MS relapses in this meta-analysis.Randomized controlled trials (RCTs evaluating the clinical efficacy, safety and tolerability of oral methylprednisolone versus intravenous methylprednisolone for MS relapses were searched in PubMed, Cochrane Library, Medline, EMBASE and China Biology Medicine until October 25, 2016, without language restrictions. The proportion of patients who had improved by day 28 was chosen as the efficacy outcome. We chose the risk ratio (RR to analyze each trial with the 95% confidence interval (95% CI. We also used the fixed-effects model (Mantel-Haenszel approach to calculate the pooled relative effect estimates.A total of 5 trials were identified, which included 369 patients. The results of our meta-analysis revealed that no significant difference existed in relapse improvement at day 28 between oMP and ivMP (RR 0.96, 95% CI 0.84 to 1.10. No evidence of heterogeneity existed among the trials (P = 0.45, I2 = 0%. Both treatments were equally safe and well tolerated except that insomnia was more likely to occur in the oMP group compared to the ivMP group.Our meta-analysis reveals strong evidence that oMP is not inferior to ivMP in increasing the proportion of patients experiencing clinical improvement at day 28. In addition, both routes of administration are equally well tolerated and safe. These findings suggest that we may be able to replace ivMP with oMP to treat MS relapses.

  11. Systematic review and meta-analysis of the sero-epidemiological association between Epstein Barr virus and multiple sclerosis.

    Science.gov (United States)

    Almohmeed, Yahya H; Avenell, Alison; Aucott, Lorna; Vickers, Mark A

    2013-01-01

    A role for Epstein Barr virus (EBV) in multiple sclerosis (MS) has been postulated. Previous systematic reviews found higher prevalences of anti-EBV antibodies in MS patients compared to controls, but many studies have since been published, and there is a need to apply more rigorous systematic review methods. We examined the link between EBV and MS by conducting a systematic review and meta-analysis of case-control and cohort studies that examined the prevalence of anti-EBV antibodies in the serum of cases and controls. We searched Medline and Embase databases from 1960 to 2012, with no language restriction. The Mantel-Haenszel odds ratios (OR) for anti-EBV antibodies sero-positivity were calculated, and meta-analysis conducted. Quality assessment was performed using a modified version of the Newcastle Ottawa scale. Thirty-nine studies were included. Quality assessment found most studies reported acceptable selection and comparability of cases and controls. However the majority had poor reporting of ascertainment of exposure. Most studies found a higher sero-prevalence of anti-EBNA IgG and anti-VCA IgG in cases compared to controls. The results for anti-EA IgG were mixed with only half the studies finding a higher sero-prevalence in cases. The meta-analysis showed a significant OR for sero-positivity to anti-EBNA IgG and anti-VCA IgG in MS cases (4.5 [95% confidence interval (CI) 3.3 to 6.6, p<0.00001] and 4.5 [95% CI 2.8 to 7.2, p<0.00001] respectively). However, funnel plot examination suggested publication bias for the reporting of the anti-EBNA IgG. No significant difference in the OR for sero-positivity to anti-EA IgG was found (1.4 [95% CI 0.9 to 2.1, p = 0.09]). These findings support previous systematic reviews, however publication bias cannot be excluded. The methodological conduct of studies could be improved, particularly with regard to reporting and conduct of laboratory analyses.

  12. Systematic review and meta-analysis of the sero-epidemiological association between Epstein Barr virus and multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Yahya H Almohmeed

    Full Text Available BACKGROUND: A role for Epstein Barr virus (EBV in multiple sclerosis (MS has been postulated. Previous systematic reviews found higher prevalences of anti-EBV antibodies in MS patients compared to controls, but many studies have since been published, and there is a need to apply more rigorous systematic review methods. METHODOLOGY/PRINCIPAL FINDINGS: We examined the link between EBV and MS by conducting a systematic review and meta-analysis of case-control and cohort studies that examined the prevalence of anti-EBV antibodies in the serum of cases and controls. We searched Medline and Embase databases from 1960 to 2012, with no language restriction. The Mantel-Haenszel odds ratios (OR for anti-EBV antibodies sero-positivity were calculated, and meta-analysis conducted. Quality assessment was performed using a modified version of the Newcastle Ottawa scale. Thirty-nine studies were included. Quality assessment found most studies reported acceptable selection and comparability of cases and controls. However the majority had poor reporting of ascertainment of exposure. Most studies found a higher sero-prevalence of anti-EBNA IgG and anti-VCA IgG in cases compared to controls. The results for anti-EA IgG were mixed with only half the studies finding a higher sero-prevalence in cases. The meta-analysis showed a significant OR for sero-positivity to anti-EBNA IgG and anti-VCA IgG in MS cases (4.5 [95% confidence interval (CI 3.3 to 6.6, p<0.00001] and 4.5 [95% CI 2.8 to 7.2, p<0.00001] respectively. However, funnel plot examination suggested publication bias for the reporting of the anti-EBNA IgG. No significant difference in the OR for sero-positivity to anti-EA IgG was found (1.4 [95% CI 0.9 to 2.1, p = 0.09]. CONCLUSION/SIGNIFICANCE: These findings support previous systematic reviews, however publication bias cannot be excluded. The methodological conduct of studies could be improved, particularly with regard to reporting and conduct of

  13. E-Cigarettes and Smoking Cessation: Evidence from a Systematic Review and Meta-Analysis

    Science.gov (United States)

    Rahman, Muhammad Aziz; Hann, Nicholas; Wilson, Andrew; Mnatzaganian, George; Worrall-Carter, Linda

    2015-01-01

    Background E-cigarettes are currently being debated regarding their possible role in smoking cessation and as they are becoming increasingly popular, the research to date requires investigation. Objectives To investigate whether the use of e-cigarettes is associated with smoking cessation or reduction, and whether there is any difference in efficacy of e-cigarettes with and without nicotine on smoking cessation. Data Sources A systematic review of articles with no limit on publication date was conducted by searching PubMed, Web of Knowledge and Scopus databases. Methods Published studies, those reported smoking abstinence or reduction in cigarette consumption after the use of e-cigarettes, were included. Studies were systematically reviewed, and meta-analyses were conducted using Mantel-Haenszel fixed-effect and random-effects models. Degree of heterogeneity among studies and quality of the selected studies were evaluated. Results Six studies were included involving 7,551 participants. Meta-analyses included 1,242 participants who had complete data on smoking cessation. Nicotine filled e-cigarettes were more effective for cessation than those without nicotine (pooled Risk Ratio 2.29, 95%CI 1.05-4.97). Amongst 1,242 smokers, 224 (18%) reported smoking cessation after using nicotine-enriched e-cigarettes for a minimum period of six months. Use of such e-cigarettes was positively associated with smoking cessation with a pooled Effect Size of 0.20 (95%CI 0.11-0.28). Use of e-cigarettes was also associated with a reduction in the number of cigarettes used. Limitations Included studies were heterogeneous, due to different study designs and gender variation. Whilst we were able to comment on the efficacy of nicotine vs. non-nicotine e-cigarettes for smoking cessation, we were unable to comment on the efficacy of e-cigarettes vs. other interventions for cessation, given the lack of comparator groups in the studies included in this meta-analysis. Conclusions Use of e

  14. Systematic Review of Infrapopliteal Drug-Eluting Stents: A Meta-Analysis of Randomized Controlled Trials

    Energy Technology Data Exchange (ETDEWEB)

    Katsanos, Konstantinos, E-mail: katsanos@med.upatras.gr [NHS Foundation Trust, King' s Health Partners, Department of Interventional Radiology, Guy' s and St. Thomas' Hospitals (United Kingdom); Spiliopoulos, Stavros [Patras University Hospital, Department of Interventional Radiology, School of Medicine (Greece); Diamantopoulos, Athanasios [NHS Foundation Trust, King' s Health Partners, Department of Interventional Radiology, Guy' s and St. Thomas' Hospitals (United Kingdom); Karnabatidis, Dimitris [Patras University Hospital, Department of Interventional Radiology, School of Medicine (Greece); Sabharwal, Tarun [NHS Foundation Trust, King' s Health Partners, Department of Interventional Radiology, Guy' s and St. Thomas' Hospitals (United Kingdom); Siablis, Dimitris [Patras University Hospital, Department of Interventional Radiology, School of Medicine (Greece)

    2013-06-15

    IntroductionDrug-eluting stents (DES) have been proposed for the treatment of infrapopliteal arterial disease. We performed a systematic review to provide a qualitative analysis and quantitative data synthesis of randomized controlled trials (RCTs) assessing infrapopliteal DES.Materials and MethodsPubMed (Medline), EMBASE (Excerpta Medical Database), AMED (Allied and Complementary medicine Database), Scopus, CENTRAL (Cochrane Central Register of Controlled Trials), online content, and abstract meetings were searched in September 2012 for eligible RCTs according to the preferred reporting items for systematic reviews and meta-analyses selection process. Risk of bias was assessed using the Cochrane Collaboration's tool. Primary endpoint was primary patency defined as absence of {>=}50 % vessel restenosis at 1 year. Secondary outcome measures included patient survival, limb amputations, change of Rutherford-Becker class, target lesion revascularization (TLR) events, complete wound healing, and event-free survival at 1 year. Risk ratio (RRs) were calculated using the Mantel-Haenszel fixed effects model, and number-needed-to-treat values are reported.ResultsThree RCTs involving 501 patients with focal infrapopliteal lesions were analyzed (YUKON-BTX, DESTINY, and ACHILLES trials). All three RCTs included relatively short and focal infrapopliteal lesions. At 1 year, there was clear superiority of infrapopliteal DES compared with control treatments in terms of significantly higher primary patency (80.0 vs. 58.5 %; pooled RR = 1.37, 95 % confidence interval [CI] = 1.18-1.58, p < 0.0001; number-needed-to-treat (NNT) value = 4.8), improvement of Rutherford-Becker class (79.0 vs. 69.6 %; pooled RR = 1.13, 95 % CI = 1.002-1.275, p = 0.045; NNT = 11.1), decreased TLR events (9.9 vs. 22.0 %; pooled RR = 0.45, 95 % CI = 0.28-0.73, p = 0.001; NNT = 8.3), improved wound healing (76.8 vs. 59.7 %; pooled RR = 1.29, 95 % CI = 1.02-1.62, p = 0.04; NNT = 5.9), and better overall

  15. Immediate Allergic Reactions to Gadolinium-based Contrast Agents: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Behzadi, Ashkan Heshmatzadeh; Zhao, Yize; Farooq, Zerwa; Prince, Martin R

    2018-02-01

    Purpose To perform a systematic review and meta-analysis to determine if there are differences in rates of immediate allergic events between classes of gadolinium-based contrast agents (GBCAs). Materials and Methods PubMed and Google Scholar databases were searched for studies in which rates of immediate adverse events to GBCAs were reported. The American College of Radiology classification system was used to characterize allergic-like events as mild, moderate, or severe, and the total number of administrations of each GBCA was recorded. Where necessary, authors of studies were contacted to clarify data and eliminate physiologic reactions. Relative risks of GBCA types were estimated by using the Mantel-Haenszel type method. Results Nine studies in which immediate reactions to GBCA were recorded from a total of 716 978 administrations of GBCA met the criteria for inclusion and exclusion. The overall and severe rates of GBCA allergic-like adverse events were 9.2 and 0.52 per 10 000 administrations, respectively: 81% (539 of 662) were mild, 13% (86 of 662) were moderate, and 6% (37 of 662) were severe reactions. The nonionic linear chelate gadodiamide had the lowest rate of reactions, at 1.5 (95% confidence interval [CI]: 0.74, 2.4) per 10 000 administrations, which was significantly less than that of linear ionic GBCAs at 8.3 (95% CI: 7.5, 9.2) per 10 000 administrations (relative risk, 0.19 [95% CI: 0.099, 0.36]; P < .00001) and less than that for nonionic macrocyclic GBCAs at 16 (95% CI: 14, 19) per 10 000 administrations (relative risk, 0.12 [95% CI: 0.05, 0.31]; P < .001). GBCAs known to be associated with protein binding had a higher rate of reactions, at 17 (95% CI: 15, 20) per 10 000 administrations compared with the same chelate classification without protein binding, at 5.2 (95% CI: 4.5, 6.0) per 10 000 administrations (relative risk, 3.1 [95% CI: 2.4, 3.8]; P < .0001). Conclusion These data show the lowest rate of immediate allergic adverse events with use

  16. Discourse analysis in general practice: a sociolinguistic approach.

    Science.gov (United States)

    Nessa, J; Malterud, K

    1990-06-01

    It is a simple but important fact that as general practitioners we talk to our patients. The quality of the conversation is of vital importance for the outcome of the consultation. The purpose of this article is to discuss a methodological tool borrowed from sociolinguistics--discourse analysis. To assess the suitability of this method for analysis of general practice consultations, the authors have performed a discourse analysis of one single consultation. Our experiences are presented here.

  17. Macrophage migration inhibitory factor gene polymorphisms in inflammatory bowel disease: an association study in New Zealand Caucasians and meta-analysis.

    Science.gov (United States)

    Falvey, James D; Bentley, Robert W; Merriman, Tony R; Hampton, Mark B; Barclay, Murray L; Gearry, Richard B; Roberts, Rebecca L

    2013-10-21

    To investigate the association of macrophage migration inhibitory factor (MIF) promoter polymorphisms with inflammatory bowel disease (IBD) risk. One thousand and six New Zealand Caucasian cases and 540 Caucasian controls were genotyped for the MIF SNP -173G > C (rs755622) and the repeat polymorphism CATT₅₋₈ (rs5844572) using a pre-designed TaqMan SNP assay and capillary electrophoresis, respectively. Data were analysed for single site and haplotype association with IBD risk and phenotype. Meta-analysis was employed, to assess cumulative evidence of association of MIF -173G > C with IBD. All published genotype data for MIF -173G > C in IBD were identified using PubMed and subsequently searching the references of all PubMed-identified studies. Imputed genotypes for MIF -173G > C were generated from the Wellcome Trust Case Control Consortium (and National Institute of Diabetes and Digestive and Kidney Diseases). Separate meta-analyses were performed on Caucasian Crohn's disease (CD) (3863 patients, 6031 controls), Caucasian ulcerative colitis (UC) (1260 patients, 1987 controls), and East Asian UC (416 patients and 789 controls) datasets using the Mantel-Haenszel method. The New Zealand dataset had 93% power, and the meta-analyses had 100% power to detect an effect size of OR = 1.40 at α = 0.05, respectively. In our New Zealand dataset, single-site analysis found no evidence of association of MIF polymorphisms with overall risk of CD, UC, and IBD or disease phenotype (all P values > 0.05). Haplotype analysis found the CATT₅/-173C haplotype occurred at a higher frequency in New Zealand controls compared to IBD patients (0.6 vs 0.01; P = 0.03, OR = 0.22; 95%CI: 0.05-0.99), but this association did not survive bonferroni correction. Meta-analysis of our New Zealand MIF -173G > C data with data from seven additional Caucasian datasets using a random effects model found no association of MIF polymorphisms with CD, UC, or overall IBD. Similarly, meta-analysis of

  18. Associations between Methylenetetrahydrofolate Reductase (MTHFR Polymorphisms and Non-Alcoholic Fatty Liver Disease (NAFLD Risk: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Man-Yi Sun

    Full Text Available C677T and A1298C are the most common allelic variants of Methylenetetrahydrofolate Reductase (MTHFR gene. The association between MTHFR polymorphisms and the occurrence of non-alcoholic fatty liver disease (NAFLD remains controversial. This study was thus performed to examine whether MTHFR mutations are associated with the susceptibility to NAFLD.A first meta-analysis on the association between the MTHFR polymorphisms and NAFLD risks was carried out via Review Manager 5.0 and Stata/SE 12.0 software. The on-line databases, such as PubMed, EMBASE, CENTRAL, WOS, Scopus and EBSCOhost (updated to April 1st, 2016, were searched for eligible case-control studies. The odd radio (OR, 95% confidence interval (CI and P value were calculated through Mantel-Haenszel statistics under random- or fixed-effect model.Eight articles (785 cases and 1188 controls contributed data to the current meta-analysis. For C677T, increased NAFLD risks were observed in case group under homozygote model (T/T vs C/C, OR = 1.49, 95% CI = 1.03~2.15, P = 0.04 and recessive model (T/T vs C/C+C/T, OR = 1.42, 95% CI = 1.07~1.88, P = 0.02, but not the other genetics models, compared with control group. For A1298C, significantly increased NAFLD risks were detected in allele model (C vs A, OR = 1.53, 95% CI = 1.13~2.07, P = 0.006, homozygote model (C/C vs A/A, OR = 2.81, 95% CI = 1.63~4.85, P = 0.0002, dominant model (A/C+C/C vs A/A, OR = 1.60, 95% CI = 1.06~2.41, P = 0.03 and recessive model (C/C vs A/A+A/C, OR = 2.08, 95% CI = 1.45~3.00, P<0.0001, but not heterozygote model.T/T genotype of MTHFR C677T polymorphism and C/C genotype of MTHFR A1298C are more likely to be associated with the susceptibility to NAFLD.

  19. Associations between Methylenetetrahydrofolate Reductase (MTHFR) Polymorphisms and Non-Alcoholic Fatty Liver Disease (NAFLD) Risk: A Meta-Analysis

    Science.gov (United States)

    Sun, Man-Yi; Zhang, Li; Shi, Song-Li; Lin, Jing-Na

    2016-01-01

    Background C677T and A1298C are the most common allelic variants of Methylenetetrahydrofolate Reductase (MTHFR) gene. The association between MTHFR polymorphisms and the occurrence of non-alcoholic fatty liver disease (NAFLD) remains controversial. This study was thus performed to examine whether MTHFR mutations are associated with the susceptibility to NAFLD. Methods A first meta-analysis on the association between the MTHFR polymorphisms and NAFLD risks was carried out via Review Manager 5.0 and Stata/SE 12.0 software. The on-line databases, such as PubMed, EMBASE, CENTRAL, WOS, Scopus and EBSCOhost (updated to April 1st, 2016), were searched for eligible case-control studies. The odd radio (OR), 95% confidence interval (CI) and P value were calculated through Mantel-Haenszel statistics under random- or fixed-effect model. Results Eight articles (785 cases and 1188 controls) contributed data to the current meta-analysis. For C677T, increased NAFLD risks were observed in case group under homozygote model (T/T vs C/C, OR = 1.49, 95% CI = 1.03~2.15, P = 0.04) and recessive model (T/T vs C/C+C/T, OR = 1.42, 95% CI = 1.07~1.88, P = 0.02), but not the other genetics models, compared with control group. For A1298C, significantly increased NAFLD risks were detected in allele model (C vs A, OR = 1.53, 95% CI = 1.13~2.07, P = 0.006), homozygote model (C/C vs A/A, OR = 2.81, 95% CI = 1.63~4.85, P = 0.0002), dominant model (A/C+C/C vs A/A, OR = 1.60, 95% CI = 1.06~2.41, P = 0.03) and recessive model (C/C vs A/A+A/C, OR = 2.08, 95% CI = 1.45~3.00, P<0.0001), but not heterozygote model. Conclusion T/T genotype of MTHFR C677T polymorphism and C/C genotype of MTHFR A1298C are more likely to be associated with the susceptibility to NAFLD. PMID:27128842

  20. Associations between Methylenetetrahydrofolate Reductase (MTHFR) Polymorphisms and Non-Alcoholic Fatty Liver Disease (NAFLD) Risk: A Meta-Analysis.

    Science.gov (United States)

    Sun, Man-Yi; Zhang, Li; Shi, Song-Li; Lin, Jing-Na

    2016-01-01

    C677T and A1298C are the most common allelic variants of Methylenetetrahydrofolate Reductase (MTHFR) gene. The association between MTHFR polymorphisms and the occurrence of non-alcoholic fatty liver disease (NAFLD) remains controversial. This study was thus performed to examine whether MTHFR mutations are associated with the susceptibility to NAFLD. A first meta-analysis on the association between the MTHFR polymorphisms and NAFLD risks was carried out via Review Manager 5.0 and Stata/SE 12.0 software. The on-line databases, such as PubMed, EMBASE, CENTRAL, WOS, Scopus and EBSCOhost (updated to April 1st, 2016), were searched for eligible case-control studies. The odd radio (OR), 95% confidence interval (CI) and P value were calculated through Mantel-Haenszel statistics under random- or fixed-effect model. Eight articles (785 cases and 1188 controls) contributed data to the current meta-analysis. For C677T, increased NAFLD risks were observed in case group under homozygote model (T/T vs C/C, OR = 1.49, 95% CI = 1.03~2.15, P = 0.04) and recessive model (T/T vs C/C+C/T, OR = 1.42, 95% CI = 1.07~1.88, P = 0.02), but not the other genetics models, compared with control group. For A1298C, significantly increased NAFLD risks were detected in allele model (C vs A, OR = 1.53, 95% CI = 1.13~2.07, P = 0.006), homozygote model (C/C vs A/A, OR = 2.81, 95% CI = 1.63~4.85, P = 0.0002), dominant model (A/C+C/C vs A/A, OR = 1.60, 95% CI = 1.06~2.41, P = 0.03) and recessive model (C/C vs A/A+A/C, OR = 2.08, 95% CI = 1.45~3.00, PMTHFR C677T polymorphism and C/C genotype of MTHFR A1298C are more likely to be associated with the susceptibility to NAFLD.

  1. Impaired glucose tolerance, type 2 diabetes and metabolic syndrome in polycystic ovary syndrome: a systematic review and meta-analysis.

    Science.gov (United States)

    Moran, Lisa J; Misso, Marie L; Wild, Robert A; Norman, Robert J

    2010-01-01

    BACKGROUND Polycystic ovary syndrome (PCOS) is a common condition in reproductive-aged women associated with impaired glucose tolerance (IGT), type 2 diabetes mellitus (DM2) and the metabolic syndrome. METHODS A literature search was conducted (MEDLINE, CINAHL, EMBASE, clinical trial registries and hand-searching) identifying studies reporting prevalence or incidence of IGT, DM2 or metabolic syndrome in women with and without PCOS. Data were presented as odds ratio (OR) [95% confidence interval (CI)] with fixed- and random-effects meta-analysis by Mantel-Haenszel methods. Quality testing was based on Newcastle-Ottawa Scaling and The Cochrane Collaboration's risk of bias assessment tool. Literature searching, data abstraction and quality appraisal were performed by two investigators. RESULTS A total of 2192 studies were reviewed and 35 were selected for final analysis. Women with PCOS had increased prevalence of IGT (OR 2.48, 95% CI 1.63, 3.77; BMI-matched studies OR 2.54, 95% CI 1.44, 4.47), DM2 (OR 4.43, 95% CI 4.06, 4.82; BMI-matched studies OR 4.00, 95% CI 1.97, 8.10) and metabolic syndrome (OR 2.88, 95% CI 2.40, 3.45; BMI-matched studies OR 2.20, 95% CI 1.36, 3.56). One study assessed IGT/DM2 incidence and reported no significant differences in DM2 incidence (OR 2.07, 95% CI 0.68, 6.30). One study assessed conversion from normal glucose tolerance to IGT/DM2 (OR 2.4, 95% CI 0.7, 8.0). No studies reported metabolic syndrome incidence. CONCLUSIONS Women with PCOS had an elevated prevalence of IGT, DM2 and metabolic syndrome in both BMI and non-BMI-matched studies. Few studies have determined IGT/DM2 or metabolic syndrome incidence in women with and without PCOS and further research is required.

  2. Risk of cardiovascular serious adverse events associated with varenicline use for tobacco cessation: systematic review and meta-analysis.

    Science.gov (United States)

    Prochaska, Judith J; Hilton, Joan F

    2012-05-04

    To examine the risk of treatment emergent, cardiovascular serious adverse events associated with varenicline use for tobacco cessation. Meta-analysis comparing study effects using four summary estimates. Medline, Cochrane Library, online clinical trials registries, and reference lists of identified articles. We included randomised controlled trials of current tobacco users of adult age comparing use of varenicline with an inactive control and reporting adverse events. We defined treatment emergent, cardiovascular serious adverse events as occurring during drug treatment or within 30 days of discontinuation, and included any ischaemic or arrhythmic adverse cardiovascular event (myocardial infarction, unstable angina, coronary revascularisation, coronary artery disease, arrhythmias, transient ischaemic attacks, stroke, sudden death or cardiovascular related death, or congestive heart failure). We identified 22 trials; all were double blinded and placebo controlled; two included participants with active cardiovascular disease and 11 enrolled participants with a history of cardiovascular disease. Rates of treatment emergent, cardiovascular serious adverse events were 0.63% (34/5431) in the varenicline groups and 0.47% (18/3801) in the placebo groups. The summary estimate for the risk difference, 0.27% (95% confidence interval -0.10 to 0.63; P = 0.15), based on all 22 trials, was neither clinically nor statistically significant. For comparison, the relative risk (1.40, 0.82 to 2.39; P = 0.22), Mantel-Haenszel odds ratio (1.41, 0.82 to 2.42; P = 0.22), and Peto odds ratio (1.58, 0.90 to 2.76; P = 0.11), all based on 14 trials with at least one event, also indicated a non-significant difference between varenicline and placebo groups. This meta--analysis--which included all trials published to date, focused on events occurring during drug exposure, and analysed findings using four summary estimates-found no significant increase in cardiovascular serious adverse events

  3. The effect of laser-assisted hatching on pregnancy outcomes of cryopreserved-thawed embryo transfer: a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Zeng, MeiFang; Su, SuQin; Li, LiuMing

    2018-04-01

    It is well known that laser-assisted hatching (LAH) is the most popular and ideal embryo hatching technology, but the relevance to pregnancy outcomes of cryopreserved-thawed embryo transfer (ET) is controversial. The purpose of this meta-analysis was to evaluate the effects of LAH on pregnancy outcomes of cryopreserved-thawed ET. We searched for relevant studies published in the PubMed, EMBASE, and Cochrane Central databases up to March 2017. This meta-analysis was primarily used to evaluate the effect of laser-assisted hatching on assisted reproductive outcomes: clinical pregnancy, embryo implantation, multiple pregnancy, miscarriage, and live birth. Using the Mantel-Haenszel fixed effects model and random effects model, we determined the summary odds ratios (OR) with 95% confidence intervals (CIs). There were 12 randomized controlled trials (more than 2574 participants) included in our analysis. The rates of clinical pregnancy (OR = 1.65, 95% CI = 1.24-2.19, I 2  = 49), implantation (OR = 1.59, 95% CI = 1.06-2.38, I 2  = 82%), multiple pregnancy (OR = 2.30, 95% CI = 1.30-4.07, I 2  = 33%), miscarriage (OR = 0.86, 95% CI = 0.50-1.48, I 2  = 0%), and live birth (OR = 1.09, 95% CI = 0.77-1.54, I 2  = 0%) revealed comparable results for both groups. In summary, this meta-analysis demonstrates that LAH is related to a higher clinical pregnancy rate, embryo implantation rate, and multiple pregnancy rate in women with cryopreserved-thawed embryos. However, LAH is unlikely to increase live birth rates and miscarriage rates. Due to the small sample evaluated in the pool of included studies, large-scale, prospective, randomized, controlled trials are required to determine if these small effects are clinically relevant.

  4. Parallel Enhancements of the General Mission Analysis Tool Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The General Mission Analysis Tool (GMAT) is a state of the art spacecraft mission design tool under active development at NASA's Goddard Space Flight Center (GSFC)....

  5. Parallel Enhancements of the General Mission Analysis Tool, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The General Mission Analysis Tool (GMAT) is a state of the art spacecraft mission design tool under active development at NASA's Goddard Space Flight Center (GSFC)....

  6. Drug-Eluting Balloon versus New-Generation Drug-Eluting Stent for the Treatment of In-Stent Restenosis: An Updated Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Cui, Kong-Yong; Lyu, Shu-Zheng; Zhang, Min; Song, Xian-Tao; Yuan, Fei; Xu, Feng

    2018-03-05

    Currently, drug-eluting balloon (DEB) appears to be an attractive alternative option for the treatment of in-stent restenosis (ISR). Nevertheless, the clinical outcomes of DEB have seldom been compared to those of new-generation drug-eluting stent (DES). Thus, this meta-analysis aimed to evaluate the safety and efficacy of DEB compared to those of new-generation DES in the treatment of ISR. A comprehensive search of electronic databases including PubMed, EMBASE, and Cochrane Library up to November 2, 2017 was performed to identify pertinent articles comparing DEB to new-generation DES for the treatment of ISR. In addition, conference proceedings for the scientific sessions of the American College of Cardiology, American Heart Association, European Society of Cardiology, Transcatheter Cardiovascular Therapeutics, and EuroPCR were also searched. The primary endpoint was target lesion revascularization (TLR) at the longest follow-up. Dichotomous variables were presented as risk ratios (RR s) with 95% confidence intervals (CI s), while the overall RR s were estimated using the Mantel-Haenszel random-effects model. Five randomized controlled trials (RCTs) and eight observational studies involving 2743 patients were included in the present meta-analysis. Overall, DEB was comparable to new-generation DES in terms of TLR (RR = 1.24, 95% CI: 0.89-1.72, P = 0.21), cardiac death (RR = 1.55, 95% CI: 0.89-2.71, P = 0.12), major adverse cardiovascular event (RR = 1.21, 95% CI: 0.98-1.48, P = 0.07), myocardial infarction (RR = 1.12, 95% CI: 0.72-1.76, P = 0.62), and stent thrombosis (RR = 0.95, 95% CI: 0.38-2.42, P = 0.92). However, DEB was associated with higher risk of all-cause mortality than new-generation DES (RR = 1.65, 95% CI: 1.09-2.50, P = 0.02). This was especially true in the real-world observational studies (RR = 1.79, 95% CI: 1.12-2.88, P = 0.02). In RCTs, however, no significant difference was found between the two treatment strategies in the risk of all

  7. A Rasch analysis between schizophrenic patients and the general population

    Directory of Open Access Journals (Sweden)

    Denis Frederic

    2017-10-01

    Full Text Available The aim of this study was to test the General Oral Health Assessment Index Questionnaire (GOHAI items for differential item functioning (DIF according to demographic characteristics (gender, age and mental health status (schizophrenic disorders versus general population using Rasch analysis.

  8. Deletions at 22q11.2 in idiopathic Parkinson's disease: a combined analysis of genome-wide association data

    Science.gov (United States)

    Mok, Kin Y; Sheerin, Una; Simón-Sánchez, Javier; Salaka, Afnan; Chester, Lucy; Escott-Price, Valentina; Mantripragada, Kiran; Doherty, Karen M; Noyce, Alastair J; Mencacci, Niccolo E; Lubbe, Steven J; Williams-Gray, Caroline H; Barker, Roger A; van Dijk, Karin D; Berendse, Henk W; Heutink, Peter; Corvol, Jean-Christophe; Cormier, Florence; Lesage, Suzanne; Brice, Alexis; Brockmann, Kathrin; Schulte, Claudia; Gasser, Thomas; Foltynie, Thomas; Limousin, Patricia; Morrison, Karen E; Clarke, Carl E; Sawcer, Stephen; Warner, Tom T; Lees, Andrew J; Morris, Huw R; Nalls, Mike A; Singleton, Andrew B; Hardy, John; Abramov, Andrey Y; Plagnol, Vincent; Williams, Nigel M; Wood, Nicholas W

    2016-01-01

    Summary Background Parkinson's disease has been reported in a small number of patients with chromosome 22q11.2 deletion syndrome. In this study, we screened a series of large, independent Parkinson's disease case-control studies for deletions at 22q11.2. Methods We used data on deletions spanning the 22q11.2 locus from four independent case-control Parkinson's disease studies (UK Wellcome Trust Case Control Consortium 2, Dutch Parkinson's Disease Genetics Consortium, US National Institute on Aging, and International Parkinson's Disease Genomics Consortium studies), which were independent of the original reports of chromosome 22q11.2 deletion syndrome. We did case-control association analysis to compare the proportion of 22q11.2 deletions found, using the Fisher's exact test for the independent case-control studies and the Mantel-Haenszel test for the meta-analyses. We retrieved clinical details of patients with Parkinson's disease who had 22q11.2 deletions from the medical records of these patients. Findings We included array-based copy number variation data from 9387 patients with Parkinson's disease and 13 863 controls. Eight patients with Parkinson's disease and none of the controls had 22q11.2 deletions (p=0·00082). In the 8451 patients for whom age at onset data were available, deletions at 22q11.2 were associated with Parkinson's disease age at onset (Mann-Whitney U test p=0·001). Age at onset of Parkinson's disease was lower in patients carrying a 22q11.2 deletion (median 37 years, 95% CI 32·0–55·5; mean 42·1 years [SD 11·9]) than in those who did not carry a deletion (median 61 years, 95% CI 60·5–61·0; mean 60·3 years [SD 12·8]). A 22q11.2 deletion was present in more patients with early-onset (p22q11.2 deletions in patients with Parkinson's disease who have early presentation or features associated with the chromosome 22q11.2 deletion syndrome, or both. Funding UK Medical Research Council, UK Wellcome Trust, Parkinson's UK, Patrick Berthoud

  9. Use of probiotics in the treatment of severe acute pancreatitis: a systematic review and meta-analysis of randomized controlled trials

    Science.gov (United States)

    2014-01-01

    Introduction Necrotic tissue infection can worsen the prognosis of severe acute pancreatitis (SAP), and probiotics have been shown to be beneficial in reducing the infection rate in animal experiments and primary clinical trials. However, the results of multicenter randomized clinical trials have been contradictory. Our aim in this study was to systematically review and quantitatively analyze all randomized controlled trials with regard to important outcomes in patients with predicted SAP who received probiotics. Methods A systematic literature search of the PubMed, Embase and Cochrane Library databases was conducted using specific search terms. Eligible studies were randomized controlled trials that compared the effects of probiotic with placebo treatment in patients with predicted SAP. Mean difference (MD), risk ratio (RR) and 95% confidence interval (95% CI) were calculated using the Mantel-Haenszel fixed- and random-effects models. A meta-analysis on the use of probiotics in the treatment of critically ill patients was also performed to serve as a reference. Results In this study, 6 trials comprising an aggregate total of 536 patients were analyzed. Significant heterogeneities were observed in the type, dose, treatment duration and clinical effects of probiotics in these trials. Systematic analysis showed that probiotics did not significantly affect the pancreatic infection rate (RR = 1.19, 95% CI = 0.74 to 1.93; P = 0.47), total infections (RR = 1.09, 95% CI = 0.80 to 1.48; P = 0.57), operation rate (RR = 1.42, 95% CI = 0.43 to 3.47; P = 0.71), length of hospital stay (MD = 2.45, 95% CI = −2.71 to 7.60; P = 0.35) or mortality (RR = 0.72, 95% CI = 0.42 to 1.45; P = 0.25). Conclusions Probiotics showed neither beneficial nor adverse effects on the clinical outcomes of patients with predicted SAP. However, significant heterogeneity was noted between the trials reviewed with regard to the type, dose and

  10. Outcomes of ≤6-month versus 12-month dual antiplatelet therapy after drug-eluting stent implantation: A meta-analysis and meta-regression.

    Science.gov (United States)

    Villablanca, Pedro A; Massera, Daniele; Mathew, Verghese; Bangalore, Sripal; Christia, Panagiota; Perez, Irving; Wan, Ningxin; Schulz-Schüpke, Stefanie; Briceno, David F; Bortnick, Anna E; Garcia, Mario J; Lucariello, Richard; Menegus, Mark; Pyo, Robert; Wiley, Jose; Ramakrishna, Harish

    2016-12-01

    The benefit of ≤6-month compared with 12-month dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) placement remains controversial. We performed a meta-analysis and meta-regression of ≤6-month versus 12-month DAPT in patients undergoing PCI with DES placement. We conducted electronic database searches of randomized controlled trials (RCTs) comparing DAPT durations after DES placement. For studies with longer follow-up, outcomes at 12 months were identified. Odds ratios and 95% confidence intervals were computed with the Mantel-Haenszel method. Fixed-effect models were used; if heterogeneity (I) > 40 was identified, effects were obtained with random models. Nine RCTs were included with total n = 19,224 patients. No significant differences were observed between ≤6-month compared with 12-month DAPT in all-cause mortality (OR 0.87; 95% confidence interval (CI): 0.69-1.11), cardiovascular (CV) mortality (OR 0.89; 95% CI: 0.66-1.21), non-CV mortality (OR 0.85; 95% 0.58-1.24), myocardial infarction (OR 1.10; 95% CI: 0.89-1.37), stroke (OR 0.97; 95% CI: 0.67-1.42), stent thrombosis (ST) (OR 1.37; 95% CI: 0.89-2.10), and target vessel revascularization (OR 0.95; 95% CI: 0.77-1.18). No significant difference in major bleeding (OR 0.72; 95% CI: 0.49-1.05) was observed, though the all-bleeding event rate was significantly lower in the ≤6-month DAPT group (OR 0.76; 95% CI: 0.59-0.96). In the meta-regression analysis, a significant association between bleeding events and non-CV mortality with 12-month DAPT was found, as well as between ST and mortality in addition to MI with ≤6-month DAPT. DAPT for ≤6 months is associated with similar mortality and ischemic outcomes but less bleeding events compared with 12-month DAPT after PCI with DES.

  11. The Safety of Artemisinin Derivatives for the Treatment of Malaria in the 2nd or 3rd Trimester of Pregnancy: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Stephanie D Kovacs

    Full Text Available Given the high morbidity for mother and fetus associated with malaria in pregnancy, safe and efficacious drugs are needed for treatment. Artemisinin derivatives are the most effective antimalarials, but are associated with teratogenic and embryotoxic effects in animal models when used in early pregnancy. However, several organ systems are still under development later in pregnancy. We conducted a systematic review and meta-analysis of the occurrence of adverse pregnancy outcomes among women treated with artemisinins monotherapy or as artemisinin-based combination therapy during the 2nd or 3rd trimesters relative to pregnant women who received non-artemisinin antimalarials or none at all. Pooled odds ratio (POR were calculated using Mantel-Haenszel fixed effects model with a 0.5 continuity correction for zero events. Eligible studies were identified through Medline, Embase, and the Malaria in Pregnancy Consortium Library. Twenty studies (11 cohort studies and 9 randomized controlled trials contributed to the analysis, with 3,707 women receiving an artemisinin, 1,951 a non-artemisinin antimalarial, and 13,714 no antimalarial. The PORs (95% confidence interval (CI for stillbirth, fetal loss, and congenital anomalies when comparing artemisinin versus quinine were 0.49 (95% CI 0.24-0.97, I2 = 0%, 3 studies; 0.58 (95% CI 0.31-1.16, I2 = 0%, 6 studies; and 1.00 (95% CI 0.27-3.75, I2 = 0%, 3 studies, respectively. The PORs comparing artemisinin users to pregnant women who received no antimalarial were 1.13 (95% CI 0.77-1.66, I2 = 86.7%, 3 studies; 1.10 (95% CI 0.79-1.54, I2 = 0%, 4 studies; and 0.79 (95% CI 0.37-1.67, I2 = 0%, 3 studies for miscarriage, stillbirth and congenital anomalies respectively. Treatment with artemisinin in 2nd and 3rd trimester was not associated with increased risks of congenital malformations or miscarriage and may be was associated with a reduced risk of stillbirths compared to quinine. This study updates the reviews

  12. Effect of restrictive versus liberal transfusion strategies on outcomes in patients with cardiovascular disease in a non-cardiac surgery setting: systematic review and meta-analysis.

    Science.gov (United States)

    Docherty, Annemarie B; O'Donnell, Rob; Brunskill, Susan; Trivella, Marialena; Doree, Carolyn; Holst, Lars; Parker, Martyn; Gregersen, Merete; Pinheiro de Almeida, Juliano; Walsh, Timothy S; Stanworth, Simon J

    2016-03-29

    To compare patient outcomes of restrictive versus liberal blood transfusion strategies in patients with cardiovascular disease not undergoing cardiac surgery. Systematic review and meta-analysis. Randomised controlled trials involving a threshold for red blood cell transfusion in hospital. We searched (to 2 November 2015) CENTRAL, Medline, Embase, CINAHL, PubMed, LILACS, NHSBT Transfusion Evidence Library, ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, ISRCTN Register, and EU Clinical Trials Register. Authors were contacted for data whenever possible. Published and unpublished randomised controlled trials comparing a restrictive with liberal transfusion threshold and that included patients with cardiovascular disease. Data extraction was completed in duplicate. Risk of bias was assessed using Cochrane methods. Relative risk ratios with 95% confidence intervals were presented in all meta-analyses. Mantel-Haenszel random effects models were used to pool risk ratios. 30 day mortality, and cardiovascular events. 41 trials were identified; of these, seven included data on patients with cardiovascular disease. Data from a further four trials enrolling patients with cardiovascular disease were obtained from the authors. In total, 11 trials enrolling patients with cardiovascular disease (n=3033) were included for meta-analysis (restrictive transfusion, n=1514 patients; liberal transfusion, n=1519). The pooled risk ratio for the association between transfusion thresholds and 30 day mortality was 1.15 (95% confidence interval 0.88 to 1.50, P=0.50), with little heterogeneity (I(2)=14%). The risk of acute coronary syndrome in patients managed with restrictive compared with liberal transfusion was increased (nine trials; risk ratio 1.78, 95% confidence interval 1.18 to 2.70, P=0.01, I(2)=0%). The results show that it may not be safe to use a restrictive transfusion threshold of less than 80 g/L in patients with ongoing acute coronary syndrome or

  13. Prophylactic therapy with omeprazole for prevention of Equine Gastric Ulcer Syndrome (EGUS) in horses in active training: A meta-analysis.

    Science.gov (United States)

    Mason, L V; Moroney, J R; Mason, R J

    2018-04-17

    Guidelines regarding the impact and value of prophylaxis or maintenance therapy in Equine Gastric Ulcer Syndrome (EGUS) are not well established or defined. The merits and the magnitude of effects of prophylaxis for spontaneous or recurrent squamous gastric ulceration in horses in training are uncertain. To pool data from randomised controlled trials (RCTs) to eliminate reporting bias and evaluate the efficacy of prophylactic omeprazole in the prevention of EGUS in training horses, and secondarily to compare prophylactic dosages of omeprazole. Meta-analysis. This meta-analysis was conducted according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic literature search identified RCTs comparing omeprazole prophylaxis with sham in prevention of EGUS. Data were analysed using the Mantel-Haenszel test method to calculate risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CIs). Primary outcome was efficacy of prophylaxis. Secondary outcome was endoscopic severity of ulceration. The influence of study characteristics on the outcomes was examined by subgroup analyses. In preventing gastric ulcer occurrence, omeprazole prophylaxis was superior to sham in training horses (7 trials, 566 horses, RR 0.28, 95% CI 0.18 to 0.43; 23.4% in omeprazole prophylaxis versus 77.2% in sham; high quality evidence). Prevalence of ulceration was 75.3% and 87.2% in the sham arms of the 1 mg/kg and 2 mg/kg omeprazole groups, respectively. Severity scores were significantly lower for omeprazole versus sham (mean difference [MD] -1.05; 95% CI -1.35 to -0.69). Subgroup analyses comparing prophylactic omeprazole dosages resulted in a mean difference of -0.94 and -1.60 for the 1 mg/kg and 2 mg/kg groups, respectively. Studies showed heterogeneity with regard to prophylactic dose. Omeprazole prophylaxis in active training horses significantly reduces gastric ulceration compared with no prophylaxis

  14. Harmonic Analysis Associated with the Generalized Weinstein Operator

    Directory of Open Access Journals (Sweden)

    Ahmed Abouelaz

    2015-11-01

    Full Text Available In this paper we consider a generalized Weinstein operator ∆d,α,n on Rd−1×]0,∞[, which generalizes the Weinstein operator ∆d,α, we define the generalized Weinstein intertwining operator Rα,n which turn out to be transmutation operator between ∆d,α,n and the Laplacian operator ∆d. We build the dual of the generalized Weinstein intertwining operatortRα,n, another hand we prove the formula related Rα,n andtRα,n . We exploit these transmutation operators to develop a new harmonic analysis corresponding to ∆d,α,n.

  15. Efficacy and Safety of Metronidazole Monotherapy versus Vancomycin Monotherapy or Combination Therapy in Patients with Clostridium difficile Infection: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Rui Li

    Full Text Available Clostridium difficile infection (CDI has become a global epidemiological problem for both hospitalized patients and outpatients. The most commonly used drugs to treat CDI are metronidazole and vancomycin. The aim of this study was to compare the efficacy and safety of metronidazole monotherapy with vancomycin monotherapy and combination therapy in CDI patients.A comprehensive search without publication status or other restrictions was conducted. Studies comparing metronidazole monotherapy with vancomycin monotherapy or combination therapy in patients with CDI were considered eligible. Meta-analysis was performed using the Mantel-Haenszel fixed-effects model, and odds ratios (ORs with 95% confidence intervals (95% CIs were calculated and reported.Of the 1910 records identified, seventeen studies from thirteen articles (n = 2501 patients were included. No statistically significant difference in the rate of clinical cure was found between metronidazole and vancomycin for mild CDI (OR = 0.67, 95% CI (0.45, 1.00, p = 0.05 or between either monotherapy and combination therapy for CDI (OR = 1.07, 95% CI (0.58, 1.96, p = 0.83; however, the rate of clinical cure was lower for metronidazole than for vancomycin for severe CDI (OR = 0.46, 95% CI (0.26, 0.80, p = 0.006. No statistically significant difference in the rate of CDI recurrence was found between metronidazole and vancomycin for mild CDI (OR = 0.99, 95% CI (0.40, 2.45, p = 0.98 or severe CDI (OR = 0.98, 95% CI (0.63, 1.53, p = 0.94 or between either monotherapy and combination therapy for CDI (OR = 0.91, 95% CI (0.66, 1.26, p = 0.56. In addition, there was no significant difference in the rate of adverse events (AEs between metronidazole and vancomycin (OR = 1.18, 95% CI (0.80, 1.74, p = 0.41. In contrast, the rate of AEs was significantly lower for either monotherapy than for combination therapy (OR = 0.30, 95% CI (0.17, 0.51, p < 0.0001.Metronidazole and vancomycin are equally effective for the

  16. Wound healing and infection in surgery. The clinical impact of smoking and smoking cessation: a systematic review and meta-analysis.

    Science.gov (United States)

    Sørensen, Lars Tue

    2012-04-01

    To clarify the evidence on smoking and postoperative healing complications across surgical specialties and to determine the impact of perioperative smoking cessation intervention. Cohort studies and randomized controlled trials. Selected studies were identified through electronic databases (CENTRAL, MEDLINE, and EMBASE) and by hand searching. Multiple data on study characteristics were extracted. Risk of bias was assessed by means of the Newcastle-Ottawa Scale and Jadad score. Healing outcome was classified as necrosis, healing delay and dehiscence, surgical site infection, wound complications, hernia, and lack of fistula or bone healing. Mantel-Haenszel and inverse variance methods for meta-analysis (fixed- and random-effects models) were used. Smokers and nonsmokers were compared in 140 cohort studies including 479,150 patients. The pooled adjusted odds ratios (95% CI) were 3.60 (2.62-4.93) for necrosis, 2.07 (1.53-2.81) for healing delay and dehiscence, 1.79 (1.57-2.04) for surgical site infection, 2.27 (1.82-2.84) for wound complications, 2.07 (1.23-3.47) for hernia, and 2.44 (1.66-3.58) for lack of fistula or bone healing. Former smokers and patients who never smoked were compared in 24 studies including 47,764 patients, and former smokers and current smokers were compared in 20 studies including 40,629 patients. The pooled unadjusted odds ratios were 1.30 (1.07-1.59) and 0.69 (0.56-0.85), respectively, for healing complications combined. In 4 randomized controlled trials, smoking cessation intervention reduced surgical site infections (odds ratio, 0.43 [95% CI, 0.21-0.85]), but not other healing complications (0.51 [0.22-1.19]). Postoperative healing complications occur significantly more often in smokers compared with nonsmokers and in former smokers compared with those who never smoked. Perioperative smoking cessation intervention reduces surgical site infections, but not other healing complications.

  17. Structural dynamic analysis with generalized damping models analysis

    CERN Document Server

    Adhikari , Sondipon

    2013-01-01

    Since Lord Rayleigh introduced the idea of viscous damping in his classic work ""The Theory of Sound"" in 1877, it has become standard practice to use this approach in dynamics, covering a wide range of applications from aerospace to civil engineering. However, in the majority of practical cases this approach is adopted more for mathematical convenience than for modeling the physics of vibration damping. Over the past decade, extensive research has been undertaken on more general ""non-viscous"" damping models and vibration of non-viscously damped systems. This book, along with a related book

  18. Specific Cooperative Analysis and Design in General Hypermedia Development

    DEFF Research Database (Denmark)

    Grønbæk, Kaj; Mogensen, Preben Holst

    1994-01-01

    activities. We demonstrate how these activities informed the general hypermedia framework and application design. Use scenarios and prototypes with example data from the users’ daily work were used as sources both to trigger design ideas and new insights regarding work practice. Mutual challenging...... in specific use settings to inform development of general products. We describe and discuss the application of cooperative – i.e. participatory – analysis and design techniques in a project developing a general hypermedia framework as well as specific cooperative hypermedia applications for the engineering...... characterised the interaction between specific cooperative analysis and design activities and general development activities. Prototypes, scenarios, and concise bullet list summaries are used as the mediating artifacts in this interaction rather than comprehensive requirement and design specifications....

  19. Systematic review and meta-analysis of L1-VLP-based human papillomavirus vaccine efficacy against anogenital pre-cancer in women with evidence of prior HPV exposure.

    Science.gov (United States)

    Miltz, Ada; Price, Huw; Shahmanesh, Maryam; Copas, Andrew; Gilson, Richard

    2014-01-01

    It is unclear whether L1-VLP-based human papillomavirus (HPV) vaccines are efficacious in reducing the likelihood of anogenital pre-cancer in women with evidence of prior vaccine-type HPV exposure. This study aims to determine whether the combined results of the vaccine trials published to date provide evidence of efficacy compared with control (hepatitis A vaccine/placebo). A systematic review and meta-analysis was conducted. Randomized-controlled trials (RCTs) were identified from MEDLINE, Embase, Web of Science, PubMed, Cochrane Central Register of Controlled Trials and references of identified studies. The bivalent vaccine containing HPV-16 and 18 VLPs from GlaxoSmithKline Biologicals (Rixenstart, Belgium), the quadrivalent vaccine containing HPV-6, 11, 16, and 18 VLPs from Merck & Co., Inc., (Whitehouse Station, NJ USA), and the HPV-16 monovalent vaccine from Merck Research Laboratories (West Point, PA USA) were evaluated. Three RCT reports and two post-trial cohort studies were eligible, comprising data from 13,482 women who were included in the vaccine studies but had evidence of HPV infection at study entry. Data on efficacy was synthesized using the Mantel-Haenszel weighted fixed-effect approach, or where there was heterogeneity between studies, the DerSimonian and Laird weighted random-effect approach. The mean odds ratio (OR) and 95% confidence interval (CI) for the association between Cervarix, Gardasil and HPV-16 monovalent vaccine and HPV-associated cervical intraepithelial neoplasia grade 3 or worse was 0·90 (95% CI: 0·56, 1·44). For the association between Gardasil and HPV-associated vulval/vaginal intraepithelial neoplasia grades 2-3, the overall OR and 95% CI was 2.25 (95% CI: 0·78, 6.50). Sample size and follow-up were limited. There was no evidence that HPV vaccines are effective in preventing vaccine-type HPV associated pre-cancer in women with evidence of prior HPV exposure. Small effects of vaccination however cannot be excluded and a

  20. Systematic review and meta-analysis of L1-VLP-based human papillomavirus vaccine efficacy against anogenital pre-cancer in women with evidence of prior HPV exposure.

    Directory of Open Access Journals (Sweden)

    Ada Miltz

    Full Text Available BACKGROUND: It is unclear whether L1-VLP-based human papillomavirus (HPV vaccines are efficacious in reducing the likelihood of anogenital pre-cancer in women with evidence of prior vaccine-type HPV exposure. This study aims to determine whether the combined results of the vaccine trials published to date provide evidence of efficacy compared with control (hepatitis A vaccine/placebo. METHODS: A systematic review and meta-analysis was conducted. Randomized-controlled trials (RCTs were identified from MEDLINE, Embase, Web of Science, PubMed, Cochrane Central Register of Controlled Trials and references of identified studies. The bivalent vaccine containing HPV-16 and 18 VLPs from GlaxoSmithKline Biologicals (Rixenstart, Belgium, the quadrivalent vaccine containing HPV-6, 11, 16, and 18 VLPs from Merck & Co., Inc., (Whitehouse Station, NJ USA, and the HPV-16 monovalent vaccine from Merck Research Laboratories (West Point, PA USA were evaluated. FINDINGS: Three RCT reports and two post-trial cohort studies were eligible, comprising data from 13,482 women who were included in the vaccine studies but had evidence of HPV infection at study entry. Data on efficacy was synthesized using the Mantel-Haenszel weighted fixed-effect approach, or where there was heterogeneity between studies, the DerSimonian and Laird weighted random-effect approach. The mean odds ratio (OR and 95% confidence interval (CI for the association between Cervarix, Gardasil and HPV-16 monovalent vaccine and HPV-associated cervical intraepithelial neoplasia grade 3 or worse was 0·90 (95% CI: 0·56, 1·44. For the association between Gardasil and HPV-associated vulval/vaginal intraepithelial neoplasia grades 2-3, the overall OR and 95% CI was 2.25 (95% CI: 0·78, 6.50. Sample size and follow-up were limited. CONCLUSIONS: There was no evidence that HPV vaccines are effective in preventing vaccine-type HPV associated pre-cancer in women with evidence of prior HPV exposure. Small

  1. Variational analysis and generalized differentiation I basic theory

    CERN Document Server

    Mordukhovich, Boris S

    2006-01-01

    Contains a study of the basic concepts and principles of variational analysis and generalized differentiation in both finite-dimensional and infinite-dimensional spaces. This title presents many applications to problems in optimization, equilibria, stability and sensitivity, control theory, economics, mechanics, and more.

  2. General algorithm and sensitivity analysis for variational inequalities

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam Noor

    1992-01-01

    Full Text Available The fixed point technique is used to prove the existence of a solution for a class of variational inequalities related to odd order boundary value problems, and to suggest a general algorithm. We also study the sensitivity analysis for these variational inequalities and complementarity problems using the projection technique. Several special cases are discussed, which can be obtained from our results.

  3. Texture Analysis Using Rényi’s Generalized Entropies

    NARCIS (Netherlands)

    Grigorescu, S.E.; Petkov, N.

    2003-01-01

    We propose a texture analysis method based on Rényi’s generalized entropies. The method aims at identifying texels in regular textures by searching for the smallest window through which the minimum number of different visual patterns is observed when moving the window over a given texture. The

  4. Psychological treatment of generalized anxiety disorder: A meta-analysis.

    NARCIS (Netherlands)

    Cuijpers, P.; Sijbrandij, M.; Koole, S.L.; Huibers, M.J.H.; Berking, M.; Andersson, G.

    2014-01-01

    Recent years have seen a near-doubling of the number of studies examining the effects of psychotherapies for generalized anxiety disorder (GAD) in adults. The present article integrates this new evidence with the older literature through a quantitative meta-analysis. A total of 41 studies (with 2132

  5. Stability analysis for a general age-dependent vaccination model

    International Nuclear Information System (INIS)

    El Doma, M.

    1995-05-01

    An SIR epidemic model of a general age-dependent vaccination model is investigated when the fertility, mortality and removal rates depends on age. We give threshold criteria of the existence of equilibriums and perform stability analysis. Furthermore a critical vaccination coverage that is sufficient to eradicate the disease is determined. (author). 12 refs

  6. A new classification of HLA-DRB1 alleles based on acid-base properties of the amino acids located at positions 13, 70 and 71: impact on ACPA status or structural progression, and meta-analysis on 1235 patients with rheumatoid from two cohorts (ESPOIR and EAC cohort).

    Science.gov (United States)

    Ruyssen-Witrand, Adeline; van Steenbergen, Hanna W; van Heemst, Jurgen; Gourraud, Pierre-Antoine; Nigon, Delphine; Lukas, Cédric; Miceli-Richard, Corinne; Jamard, Bénédicte; Cambon-Thomsen, Anne; Cantagrel, Alain; Dieudé, Philippe; van der Helm-van Mil, Annette H M; Constantin, Arnaud

    2015-01-01

    To group HLA-DRB1 alleles based on acid-base properties of amino acids at positions 13, 70 and 71 and analyse their association with the presence of anticitrullinated peptide antibodies (ACPA) and structural progression in 2 cohorts of early rheumatoid arthritis (RA). Patients with RA (N=612) from ESPOIR cohort and from EAC cohort (n=624) were genotyped for HLA-DRB1 alleles. The alleles containing the RAA sequence at positions 72-74 were classified into 3 groups according to the amino acid at positions 13, 70 and 71: BB encoding basic amino acids at positions 13, 70 and 71; A encoding acidic amino acids at positions 70 and 71; and BN encoding either neutral amino acids at position 13 and basic amino acids at positions 70 and 71, or basic amino acid at position 13 and neutral amino acids at positions 70 and 71. The associations between the different alleles and (1) the ACPA presence, and (2) the structural progression were assessed by χ(2) test; a meta-analysis was performed on the 2 cohorts using the Mantel-Haenszel method. After meta-analysis, BB alleles were significantly associated with ACPA presence (OR (95% CI) 4.08 (3.14 to 5.31)) and structural progression (OR (95% CI) 2.33 (1.76 to 3.09)). The alleles protected significantly against ACPA presence (OR (95% CI) 0.37 (0.28 to 0.50)) and structural progression (OR (95% CI) 0.34 (0.23 to 0.50)). This acid-base classification allowed to separate another group BN with an intermediate risk of ACPA production (OR (95% CI) 1.14 (0.91 to 1.44)) and structural progression (OR (95% CI) 1.01 (0.77 to 1.33)). This new classification permitted to make a hierarchy of HLA-DRB1 alleles in terms of association with ACPA presence or structural progression in early RA.

  7. A general maximum likelihood analysis of variance components in generalized linear models.

    Science.gov (United States)

    Aitkin, M

    1999-03-01

    This paper describes an EM algorithm for nonparametric maximum likelihood (ML) estimation in generalized linear models with variance component structure. The algorithm provides an alternative analysis to approximate MQL and PQL analyses (McGilchrist and Aisbett, 1991, Biometrical Journal 33, 131-141; Breslow and Clayton, 1993; Journal of the American Statistical Association 88, 9-25; McGilchrist, 1994, Journal of the Royal Statistical Society, Series B 56, 61-69; Goldstein, 1995, Multilevel Statistical Models) and to GEE analyses (Liang and Zeger, 1986, Biometrika 73, 13-22). The algorithm, first given by Hinde and Wood (1987, in Longitudinal Data Analysis, 110-126), is a generalization of that for random effect models for overdispersion in generalized linear models, described in Aitkin (1996, Statistics and Computing 6, 251-262). The algorithm is initially derived as a form of Gaussian quadrature assuming a normal mixing distribution, but with only slight variation it can be used for a completely unknown mixing distribution, giving a straightforward method for the fully nonparametric ML estimation of this distribution. This is of value because the ML estimates of the GLM parameters can be sensitive to the specification of a parametric form for the mixing distribution. The nonparametric analysis can be extended straightforwardly to general random parameter models, with full NPML estimation of the joint distribution of the random parameters. This can produce substantial computational saving compared with full numerical integration over a specified parametric distribution for the random parameters. A simple method is described for obtaining correct standard errors for parameter estimates when using the EM algorithm. Several examples are discussed involving simple variance component and longitudinal models, and small-area estimation.

  8. Complexity analysis based on generalized deviation for financial markets

    Science.gov (United States)

    Li, Chao; Shang, Pengjian

    2018-03-01

    In this paper, a new modified method is proposed as a measure to investigate the correlation between past price and future volatility for financial time series, known as the complexity analysis based on generalized deviation. In comparison with the former retarded volatility model, the new approach is both simple and computationally efficient. The method based on the generalized deviation function presents us an exhaustive way showing the quantization of the financial market rules. Robustness of this method is verified by numerical experiments with both artificial and financial time series. Results show that the generalized deviation complexity analysis method not only identifies the volatility of financial time series, but provides a comprehensive way distinguishing the different characteristics between stock indices and individual stocks. Exponential functions can be used to successfully fit the volatility curves and quantify the changes of complexity for stock market data. Then we study the influence for negative domain of deviation coefficient and differences during the volatile periods and calm periods. after the data analysis of the experimental model, we found that the generalized deviation model has definite advantages in exploring the relationship between the historical returns and future volatility.

  9. Stochastic back analysis of permeability coefficient using generalized Bayesian method

    Directory of Open Access Journals (Sweden)

    Zheng Guilan

    2008-09-01

    Full Text Available Owing to the fact that the conventional deterministic back analysis of the permeability coefficient cannot reflect the uncertainties of parameters, including the hydraulic head at the boundary, the permeability coefficient and measured hydraulic head, a stochastic back analysis taking consideration of uncertainties of parameters was performed using the generalized Bayesian method. Based on the stochastic finite element method (SFEM for a seepage field, the variable metric algorithm and the generalized Bayesian method, formulas for stochastic back analysis of the permeability coefficient were derived. A case study of seepage analysis of a sluice foundation was performed to illustrate the proposed method. The results indicate that, with the generalized Bayesian method that considers the uncertainties of measured hydraulic head, the permeability coefficient and the hydraulic head at the boundary, both the mean and standard deviation of the permeability coefficient can be obtained and the standard deviation is less than that obtained by the conventional Bayesian method. Therefore, the present method is valid and applicable.

  10. Analysis of generalized rosette trajectory for compressed sensing MRI.

    Science.gov (United States)

    Li, Ya; Yang, Ran; Zhang, Cishen; Zhang, Jingxin; Jia, Sen; Zhou, Zhiyang

    2015-09-01

    The application of compressed sensing (CS) technology in magnetic resonance imaging (MRI) is to accelerate the MRI scan speed by incoherent undersampling of k-space data and nonlinear iterative reconstruction of MRI images. This paper generalizes the existing rosette trajectories to configure the sampling patterns for undersampled k-space data acquisition in MRI scans. The arch and curvature characteristics of the generalized rosette trajectories are analyzed to explore their feasibility and advantages for CS reconstruction of MRI images. Two key properties crucial to the CS MRI application, the scan speed and sampling incoherence of the generalized rosette trajectories, are analyzed. The analysis on the scan speed of generalized rosette trajectories is based on the transversal time derived from the curvature of the trajectories, and the sampling incoherence is based on the evaluation of the point spread function for the measurement matrix. The results of analysis are supported by extensive simulations where the performances of rosette, spiral, and radial sampling patterns at different acceleration factors are compared. It is shown that compared with spiral trajectories, the arch and curvature characteristics of the generalized rosette trajectories are more feasible to meet the physical requirements of undersampled k-space data acquisition in terms of time shortness and scan area. It is further shown that the sampling pattern of the rosette trajectory has higher incoherence than that of the other trajectories and can thus achieve higher reconstruction performance. Reconstruction performances illustrate that the rosette trajectory can achieve about 10% higher peak signal-to-noise ratio than radial and spiral trajectories under the high acceleration factor R = 10. The generalized rosette trajectories can be a desirable candidate for CS reconstruction of MRI.

  11. Tritium analysis of urine samples from the general Korean public.

    Science.gov (United States)

    Yoon, Seokwon; Ha, Wi-Ho; Lee, Seung-Sook

    2013-11-01

    The tritium concentrations of urine samples and the effective dose of the general Korean public were evaluated. To achieve accurate HTO analysis of urine samples, we established the optimal conditions for measuring the HTO content of urine samples. Urine samples from 50 Koreans who do not work at a nuclear facility were analyzed on the basis of the results. The average urine analysis result was 2.8 ±1 .4 Bq/L, and the range was 1.8-5.6 Bq/L. The measured values were lower than those reported for other countries. These results show that environmental factors and lifestyle differences are the main factors affecting the tritium level of the general public. © 2013 Elsevier Ltd. All rights reserved.

  12. General classification and analysis of neutron β-decay experiments

    International Nuclear Information System (INIS)

    Gudkov, V.; Greene, G.L.; Calarco, J.R.

    2006-01-01

    A general analysis of the sensitivities of neutron β-decay experiments to manifestations of possible interaction beyond the standard model is carried out. In a consistent fashion, we take into account all known radiative and recoil corrections arising in the standard model. This provides a description of angular correlations in neutron decay in terms of one parameter, which is accurate to the level of ∼10 -5 . Based on this general expression, we present an analysis of the sensitivities to new physics for selected neutron decay experiments. We emphasize that the usual parametrization of experiments in terms of the tree-level coefficients a,A, and B is inadequate when the experimental sensitivities are at the same or higher level relative to the size of the corrections to the tree-level description

  13. Robust Bayesian Analysis of Generalized Half Logistic Distribution

    Directory of Open Access Journals (Sweden)

    Ajit Chaturvedi

    2017-06-01

    Full Text Available In this paper, Robust Bayesian analysis of the generalized half logistic distribution (GHLD under an $\\epsilon$-contamination class of priors for the shape parameter $\\lambda$ is considered. ML-II Bayes estimators of the parameters, reliability function and hazard function are derived under the squared-error loss function (SELF and linear exponential (LINEX loss function by considering the Type~II censoring and the sampling scheme of Bartholomew (1963. Both the cases when scale parameter is known and unknown is considered under Type~II censoring and under the sampling scheme of Bartholomew. Simulation study and analysis of a real data set are presented.

  14. A general first-order global sensitivity analysis method

    International Nuclear Information System (INIS)

    Xu Chonggang; Gertner, George Zdzislaw

    2008-01-01

    Fourier amplitude sensitivity test (FAST) is one of the most popular global sensitivity analysis techniques. The main mechanism of FAST is to assign each parameter with a characteristic frequency through a search function. Then, for a specific parameter, the variance contribution can be singled out of the model output by the characteristic frequency. Although FAST has been widely applied, there are two limitations: (1) the aliasing effect among parameters by using integer characteristic frequencies and (2) the suitability for only models with independent parameters. In this paper, we synthesize the improvement to overcome the aliasing effect limitation [Tarantola S, Gatelli D, Mara TA. Random balance designs for the estimation of first order global sensitivity indices. Reliab Eng Syst Safety 2006; 91(6):717-27] and the improvement to overcome the independence limitation [Xu C, Gertner G. Extending a global sensitivity analysis technique to models with correlated parameters. Comput Stat Data Anal 2007, accepted for publication]. In this way, FAST can be a general first-order global sensitivity analysis method for linear/nonlinear models with as many correlated/uncorrelated parameters as the user specifies. We apply the general FAST to four test cases with correlated parameters. The results show that the sensitivity indices derived by the general FAST are in good agreement with the sensitivity indices derived by the correlation ratio method, which is a non-parametric method for models with correlated parameters

  15. General

    Indian Academy of Sciences (India)

    Page S20: NMR compound 4i. Page S22: NMR compound 4j. General: Chemicals were purchased from Fluka, Merck and Aldrich Chemical Companies. All the products were characterized by comparison of their IR, 1H NMR and 13C NMR spectroscopic data and their melting points with reported values. General procedure ...

  16. Nonlinear analysis of generalized cross-field current instability

    International Nuclear Information System (INIS)

    Yoon, P.H.; Lui, A.T.Y.

    1993-01-01

    Analysis of the generalized cross-field current instability is carried out in which cross-field drift of both the ions and electrons and their temperatures are permitted to vary in time. The unstable mode under consideration is the electromagnetic generalization of the classical modified-two-stream instability. The generalized instability is made of the modified-two-stream and ion-Weibel modes. The relative importance of the features associated with the ion-Weibel mode and those of the modified-two-stream mode is assessed. Specific applications are made to the Earth's neutral sheet prior to substorm onset and to the Earth's bow shock. The numerical solution indicates that the ion-Weibel mode dominates in the Earth's neutral sheet environment. In contrast, the situation for the bow shock is dominated by the modified-two-stream mode. Notable differences are found between the present calculation and previous results on ion-Weibel mode which restrict the analysis to only parallel propagating waves. However, in the case of Earth's bow shock for which the ion-Weibel mode plays no important role, the inclusion of the electromagnetic ion response is found to differ little from the previous results which treats ions responding only to the electrostatic component of the excited waves

  17. Analysis of General Power Counting Rules in Effective Field Theory

    CERN Document Server

    Gavela, B M; Manohar, A V; Merlo, L

    2016-01-01

    We derive the general counting rules for a quantum effective field theory (EFT) in $\\mathsf{d}$ dimensions. The rules are valid for strongly and weakly coupled theories, and predict that all kinetic energy terms are canonically normalized. They determine the energy dependence of scattering cross sections in the range of validity of the EFT expansion. The size of cross sections is controlled by the $\\Lambda$ power counting of EFT, not by chiral counting, even for chiral perturbation theory ($\\chi$PT). The relation between $\\Lambda$ and $f$ is generalized to $\\mathsf{d}$ dimensions. We show that the naive dimensional analysis $4\\pi$ counting is related to $\\hbar$ counting. The EFT counting rules are applied to $\\chi$PT, to Standard Model EFT and to the non-trivial case of Higgs EFT, which combines the $\\Lambda$ and chiral counting rules within a single theory.

  18. Computer code for general analysis of radon risks (GARR)

    International Nuclear Information System (INIS)

    Ginevan, M.

    1984-09-01

    This document presents a computer model for general analysis of radon risks that allow the user to specify a large number of possible models with a small number of simple commands. The model is written in a version of BASIC which conforms closely to the American National Standards Institute (ANSI) definition for minimal BASIC and thus is readily modified for use on a wide variety of computers and, in particular, microcomputers. Model capabilities include generation of single-year life tables from 5-year abridged data, calculation of multiple-decrement life tables for lung cancer for the general population, smokers, and nonsmokers, and a cohort lung cancer risk calculation that allows specification of level and duration of radon exposure, the form of the risk model, and the specific population assumed at risk. 36 references, 8 figures, 7 tables

  19. Analysis of incidents notified in a general hospital

    Directory of Open Access Journals (Sweden)

    Mirela Lopes de Figueiredo

    Full Text Available ABSTRACT Objective: To evaluate the incidents spontaneously notified in a general hospital in Minas Gerais. Method: Retrospective, descriptive, quantitative study performed at a general hospital in Montes Claros - Minas Gerais State. The sample comprised 1,316 incidents reported from 2011 to 2014. The data were submitted to descriptive statistical analysis using Statistical Package for the Social Sciences version 18.0. Results: The prevalence of incidents was 33.8 per 1,000 hospitalizations, with an increase during the investigation period and higher frequency in hospitalization units, emergency room and surgical center. These occurred mostly with adult clients and relative to the medication supply chain. The main causes were noncompliance with routines/protocols, necessitating changes in routines and training. Conclusion: There was a considerable prevalence of incidents and increase in notifications during the period investigated, which requires the attention of managers and hospital staff. Nevertheless, we observed development of the patient safety culture.

  20. Colombeau's generalized functions and non-standard analysis

    International Nuclear Information System (INIS)

    Todorov, T.D.

    1987-10-01

    Using some methods of the Non-Standard Analysis we modify one of Colombeau's classes of generalized functions. As a result we define a class ε-circumflex of the so-called meta-functions which possesses all good properties of Colombeau's generalized functions, i.e. (i) ε-circumflex is an associative and commutative algebra over the system of the so-called complex meta-numbers C-circumflex; (ii) Every meta-function has partial derivatives of any order (which are meta-functions again); (iii) Every meta-function is integrable on any compact set of R n and the integral is a number from C-circumflex; (iv) ε-circumflex contains all tempered distributions S', i.e. S' is contained in ε' isomorphically with respect to all linear operations (including the differentiation). Thus, within the class ε-circumflex the problem of multiplication of the tempered distributions is satisfactorily solved (every two distributions in S' have a well-defined product in ε-circumflex). The crucial point is that C-circumflex is a field in contrast to the system of Colombeau's generalized numbers C-bar which is a ring only (C-bar is the counterpart of C-circumflex in Colombeau's theory). In this way we simplify and improve slightly the properties of the integral and notion of ''values of the meta-functions'' as well as the properties of the whole class ε-circumflex itself if compared with the original Colombeau theory. And, what is maybe more important, we clarify the connection between the Non-Standard Analysis and Colombeau's theory of new generalized functions in the framework of which the problem of multiplication of distributions was recently solved. (author). 14 refs

  1. Analysis of comparative data using generalized estimating equations.

    Science.gov (United States)

    Paradis, Emmanuel; Claude, Julien

    2002-09-21

    It is widely acknowledged that the analysis of comparative data from related species should be performed taking into account their phylogenetic relationships. We introduce a new method, based on the use of generalized estimating equations (GEE), for the analysis of comparative data. The principle is to incorporate, in the modelling process, a correlation matrix that specifies the dependence among observations. This matrix is obtained from the phylogenetic tree of the studied species. Using this approach, a variety of distributions (discrete or continuous) can be analysed using a generalized linear modelling framework, phylogenies with multichotomies can be analysed, and there is no need to estimate ancestral character state. A simulation study showed that the proposed approach has good statistical properties with a type-I error rate close to the nominal 5%, and statistical power to detect correlated evolution between two characters which increases with the strength of the correlation. The proposed approach performs well for the analysis of discrete characters. We illustrate our approach with some data on macro-ecological correlates in birds. Some extensions of the use of GEE are discussed.

  2. Cost analysis of robotic versus laparoscopic general surgery procedures.

    Science.gov (United States)

    Higgins, Rana M; Frelich, Matthew J; Bosler, Matthew E; Gould, Jon C

    2017-01-01

    Robotic surgical systems have been used at a rapidly increasing rate in general surgery. Many of these procedures have been performed laparoscopically for years. In a surgical encounter, a significant portion of the total costs is associated with consumable supplies. Our hospital system has invested in a software program that can track the costs of consumable surgical supplies. We sought to determine the differences in cost of consumables with elective laparoscopic and robotic procedures for our health care organization. De-identified procedural cost and equipment utilization data were collected from the Surgical Profitability Compass Procedure Cost Manager System (The Advisory Board Company, Washington, DC) for our health care system for laparoscopic and robotic cholecystectomy, fundoplication, and inguinal hernia between the years 2013 and 2015. Outcomes were length of stay, case duration, and supply cost. Statistical analysis was performed using a t-test for continuous variables, and statistical significance was defined as p general surgery procedures for our health care system when cases commonly performed laparoscopically are instead performed robotically. Our analysis is limited by the fact that we only included costs associated with consumable surgical supplies. The initial acquisition cost (over $1 million for robotic surgical system), depreciation, and service contract for the robotic and laparoscopic systems were not included in this analysis.

  3. GNU General Public License v3: A Legal Analysis

    Directory of Open Access Journals (Sweden)

    Andrés Guadamuz González

    2006-06-01

    Full Text Available This paper offers a first-look legal analysis of the draft version 3 of the GNU General Public License, and will also look at the debate that it has generated in the Free and Open Source community. The paper will answer the following vital questions: Is the GPL v3 different in any fundamental way from GPL v2? What are the main differences? What will be the impact of the new GPL to the problem of software patents? Is there an incompatibility problem with previous versions of the licence? How does it compare with other existing licences?

  4. A κ-generalized statistical mechanics approach to income analysis

    International Nuclear Information System (INIS)

    Clementi, F; Gallegati, M; Kaniadakis, G

    2009-01-01

    This paper proposes a statistical mechanics approach to the analysis of income distribution and inequality. A new distribution function, having its roots in the framework of κ-generalized statistics, is derived that is particularly suitable for describing the whole spectrum of incomes, from the low–middle income region up to the high income Pareto power-law regime. Analytical expressions for the shape, moments and some other basic statistical properties are given. Furthermore, several well-known econometric tools for measuring inequality, which all exist in a closed form, are considered. A method for parameter estimation is also discussed. The model is shown to fit remarkably well the data on personal income for the United States, and the analysis of inequality performed in terms of its parameters is revealed as very powerful

  5. Generalization in the XCSF classifier system: analysis, improvement, and extension.

    Science.gov (United States)

    Lanzi, Pier Luca; Loiacono, Daniele; Wilson, Stewart W; Goldberg, David E

    2007-01-01

    We analyze generalization in XCSF and introduce three improvements. We begin by showing that the types of generalizations evolved by XCSF can be influenced by the input range. To explain these results we present a theoretical analysis of the convergence of classifier weights in XCSF which highlights a broader issue. In XCSF, because of the mathematical properties of the Widrow-Hoff update, the convergence of classifier weights in a given subspace can be slow when the spread of the eigenvalues of the autocorrelation matrix associated with each classifier is large. As a major consequence, the system's accuracy pressure may act before classifier weights are adequately updated, so that XCSF may evolve piecewise constant approximations, instead of the intended, and more efficient, piecewise linear ones. We propose three different ways to update classifier weights in XCSF so as to increase the generalization capabilities of XCSF: one based on a condition-based normalization of the inputs, one based on linear least squares, and one based on the recursive version of linear least squares. Through a series of experiments we show that while all three approaches significantly improve XCSF, least squares approaches appear to be best performing and most robust. Finally we show how XCSF can be extended to include polynomial approximations.

  6. Risk factors for developing tooth sensitivity and gingival irritation associated with nightguard vital bleaching.

    Science.gov (United States)

    Leonard, R H; Haywood, V B; Phillips, C

    1997-08-01

    The purpose of this study was to determine risk factors in the development of tooth sensitivity and gingival irritation associated with the nightguard vital bleaching technique. The potential risk factors evaluated (sex, age, reported allergy, whitening solution, number of times the solution was changed daily [its usage pattern], and dental arch) were collected from the daily log form turned in by each of the 64 participants after completion of the 6-week lightening process. Also evaluated for each participant, from color slides, were tooth characteristics such as gingival recession, defective restorations, abfraction lesions, enamel-cementum abrasion, etc, and reported side effects. The generalized Mantel-Haenszel statistic was used to assess the association between the potential risk factors and the development of tooth sensitivity and/or gingival irritation. No statistical relationship existed between age, sex, allergy, tooth characteristics, or the dental arch lightened and the development of side effects. Initially, a statistically significant association existed between side effects and the whitening solution used. However, when the analysis was controlled for usage pattern, this relationship disappeared. Patients who changed the whitening solution more than once a day reported statistically significantly more side effects than did those who did not change the whitening solution during their usage time.

  7. Enhanced group analysis of a semi linear generalization of a general bond-pricing equation

    Science.gov (United States)

    Bozhkov, Y.; Dimas, S.

    2018-01-01

    The enhanced group classification of a semi linear generalization of a general bond-pricing equation is carried out by harnessing the underlying equivalence and additional equivalence transformations. We employ that classification to unearth the particular cases with a larger Lie algebra than the general case and use them to find non trivial invariant solutions under the terminal and the barrier option condition.

  8. Vehicle technology under CO2 constraint: a general equilibrium analysis

    International Nuclear Information System (INIS)

    Schaefer, Andreas; Jacoby, Henry D.

    2006-01-01

    A study is presented of the rates of penetration of different transport technologies under policy constraints on CO 2 emissions. The response of this sector is analyzed within an overall national level of restriction, with a focus on automobiles, light trucks, and heavy freight trucks. Using the US as an example, a linked set of three models is used to carry out the analysis: a multi-sector computable general equilibrium model of the economy, a MARKAL-type model of vehicle and fuel supply technology, and a model simulating the split of personal and freight transport among modes. Results highlight the importance of incremental improvements in conventional internal combustion engine technology, and, in the absence of policies to overcome observed consumer discount rates, the very long time horizons before radical alternatives like the internal combustion engine hybrid drive train vehicle are likely to take substantial market share

  9. Analysis of snow feedbacks in 14 general circulation models

    Science.gov (United States)

    Randall, D. A.; Cess, R. D.; Blanchet, J. P.; Chalita, S.; Colman, R.; Dazlich, D. A.; Del Genio, A. D.; Keup, E.; Lacis, A.; Le Treut, H.; Liang, X.-Z.; McAvaney, B. J.; Mahfouf, J. F.; Meleshko, V. P.; Morcrette, J.-J.; Norris, P. M.; Potter, G. L.; Rikus, L.; Roeckner, E.; Royer, J. F.; Schlese, U.; Sheinin, D. A.; Sokolov, A. P.; Taylor, K. E.; Wetherald, R. T.; Yagai, I.; Zhang, M.-H.

    1994-10-01

    Snow feedbacks produced by 14 atmospheric general circulation models have been analyzed through idealized numerical experiments. Included in the analysis is an investigation of the surface energy budgets of the models. Negative or weak positive snow feedbacks occurred in some of the models, while others produced strong positive snow feedbacks. These feedbacks are due not only to melting snow, but also to increases in boundary temperature, changes in air temperature, changes in water vapor, and changes in cloudiness. As a result, the net response of each model is quite complex. We analyze in detail the responses of one model with a strong positive snow feedback and another with a weak negative snow feedback. Some of the models include a temperature dependence of the snow albedo, and this has significantly affected the results.

  10. An approximate analysis for general film condensation transients

    International Nuclear Information System (INIS)

    Flik, M.I.; Tien, C.L.

    1989-01-01

    This work presents a simple, powerful technique for analyzing a broad class of film condensation transients. The analysis shows that general film condensation transients are governed by the propagation of a kinematic wave along the film. Scaling arguments establish conditions for the use of quasi-steady profiles in the integral conservation equations. An elementary method permits simple solutions of the governing hyperbolic equation for time-step changes with arbitrary initial conditions. The application of this method yields closed-form solutions for step changes of body force, vapor shear, and wall temperature for a laminar film and for step changes of body force and wall temperature for a film within a porous medium. These approximate results agree excellently with numerical solutions of the complete boundary-layer equations. This technique has applications to a wide class of film condensation transients and to film boiling and convective vaporization transients

  11. Stability analysis of embedded nonlinear predictor neural generalized predictive controller

    Directory of Open Access Journals (Sweden)

    Hesham F. Abdel Ghaffar

    2014-03-01

    Full Text Available Nonlinear Predictor-Neural Generalized Predictive Controller (NGPC is one of the most advanced control techniques that are used with severe nonlinear processes. In this paper, a hybrid solution from NGPC and Internal Model Principle (IMP is implemented to stabilize nonlinear, non-minimum phase, variable dead time processes under high disturbance values over wide range of operation. Also, the superiority of NGPC over linear predictive controllers, like GPC, is proved for severe nonlinear processes over wide range of operation. The necessary conditions required to stabilize NGPC is derived using Lyapunov stability analysis for nonlinear processes. The NGPC stability conditions and improvement in disturbance suppression are verified by both simulation using Duffing’s nonlinear equation and real-time using continuous stirred tank reactor. Up to our knowledge, the paper offers the first hardware embedded Neural GPC which has been utilized to verify NGPC–IMP improvement in realtime.

  12. Analysis of Robust Quasi-deviances for Generalized Linear Models

    Directory of Open Access Journals (Sweden)

    Eva Cantoni

    2004-04-01

    Full Text Available Generalized linear models (McCullagh and Nelder 1989 are a popular technique for modeling a large variety of continuous and discrete data. They assume that the response variables Yi , for i = 1, . . . , n, come from a distribution belonging to the exponential family, such that E[Yi ] = ?i and V[Yi ] = V (?i , and that ?i = g(?i = xiT?, where ? ? IR p is the vector of parameters, xi ? IR p, and g(. is the link function. The non-robustness of the maximum likelihood and the maximum quasi-likelihood estimators has been studied extensively in the literature. For model selection, the classical analysis-of-deviance approach shares the same bad robustness properties. To cope with this, Cantoni and Ronchetti (2001 propose a robust approach based on robust quasi-deviance functions for estimation and variable selection. We refer to that paper for a deeper discussion and the review of the literature.

  13. Inverse dynamic analysis of general n-link robot manipulators

    International Nuclear Information System (INIS)

    Yih, T.C.; Wang, T.Y.; Burks, B.L.; Babcock, S.M.

    1996-01-01

    In this paper, a generalized matrix approach is derived to analyze the dynamic forces and moments (torques) required by the joint actuators. This method is general enough to solve the problems of any n-link open-chain robot manipulators with joint combinations of R(revolute), P(prismatic), and S(spherical). On the other hand, the proposed matrix solution is applicable to both nonredundant and redundant robotic systems. The matrix notation is formulated based on the Newton-Euler equations under the condition of quasi-static equilibrium. The 4 x 4 homogeneous cylindrical coordinates-Bryant angles (C-B) notation is applied to model the robotic systems. Displacements, velocities, and accelerations of each joint and link center of gravity (CG) are calculated through kinematic analysis. The resultant external forces and moments exerted on the CG of each link are considered as known inputs. Subsequently, a 6n x 6n displacement coefficient matrix and a 6n x 1 external force/moment vector can be established. At last, the joint forces and moments needed for the joint actuators to control the robotic system are determined through matrix inversion. Numerical examples will be illustrated for the nonredundant industrial robots: Bendix AA/CNC (RRP/RRR) and Unimate 2000 spherical (SP/RRR) robots; and the redundant light duty utility arm (LDUA), modified LDUA, and tank waste retrieval manipulator system

  14. General analysis of dark radiation in sequestered string models

    Energy Technology Data Exchange (ETDEWEB)

    Cicoli, Michele [ICTP,Strada Costiera 11, Trieste 34014 (Italy); Dipartimento di Fisica e Astronomia, Università di Bologna,via Irnerio 46, 40126 Bologna (Italy); INFN, Sezione di Bologna,via Irnerio 46, 40126 Bologna (Italy); Muia, Francesco [Dipartimento di Fisica e Astronomia, Università di Bologna,via Irnerio 46, 40126 Bologna (Italy); INFN, Sezione di Bologna,via Irnerio 46, 40126 Bologna (Italy)

    2015-12-22

    We perform a general analysis of axionic dark radiation produced from the decay of the lightest modulus in the sequestered LARGE Volume Scenario. We discuss several cases depending on the form of the Kähler metric for visible sector matter fields and the mechanism responsible for achieving a de Sitter vacuum. The leading decay channels which determine dark radiation predictions are to hidden sector axions, visible sector Higgses and SUSY scalars depending on their mass. We show that in most of the parameter space of split SUSY-like models squarks and sleptons are heavier than the lightest modulus. Hence dark radiation predictions previously obtained for MSSM-like cases hold more generally also for split SUSY-like cases since the decay channel to SUSY scalars is kinematically forbidden. However the inclusion of string loop corrections to the Kähler potential gives rise to a parameter space region where the decay channel to SUSY scalars opens up, leading to a significant reduction of dark radiation production. In this case, the simplest model with a shift-symmetric Higgs sector can suppress the excess of dark radiation ΔN{sub eff} to values as small as 0.14, in perfect agreement with current experimental bounds. Depending on the exact mass of the SUSY scalars all values in the range 0.14≲ΔN{sub eff}≲1.6 are allowed. Interestingly dark radiation overproduction can be avoided also in the absence of a Giudice-Masiero coupling.

  15. Gerald: a general environment for radiation analysis and design

    International Nuclear Information System (INIS)

    Boyle, Ch.; Oliveira, P.I.E. de; Oliveira, C.R.E. de; Adams, M.L.; Galan, J.M.

    2005-01-01

    Full text of publication follows: This paper describes the status of the GERALD interactive workbench for the analysis of radiation transport problems. GERALD basically guides the user through the various steps that are necessary to solve a radiation transport problem, and is aimed at education, research and industry. The advantages of such workbench are many: quality assurance of problem setup, interaction of the user with problem solution, preservation of theory and legacy research codes, and rapid proto-typing and testing of new methods. The environment is of general applicability catering for analytical, deterministic and stochastic analysis of the radiation problem and is not tied to one specific solution method or code. However, GERALD is being developed as a portable, modular, open source framework which renders itself quite naturally to the coupling of existing computational tools through specifically developed plug-ins. By offering a common route for setting up, solving and analyzing radiation transport problems GERALD offers the possibility of methods intercomparison and validation. Such flexible radiation transport environment will also facilitate the coupling of radiation physics methods to other physical phenomena and their application to other areas of application such as medical physics and the environment. (authors)

  16. Psychological treatment of generalized anxiety disorder: a meta-analysis.

    Science.gov (United States)

    Cuijpers, Pim; Sijbrandij, Marit; Koole, Sander; Huibers, Marcus; Berking, Matthias; Andersson, Gerhard

    2014-03-01

    Recent years have seen a near-doubling of the number of studies examining the effects of psychotherapies for generalized anxiety disorder (GAD) in adults. The present article integrates this new evidence with the older literature through a quantitative meta-analysis. A total of 41 studies (with 2132 patients meeting diagnostic criteria for GAD) were identified through systematic searches in bibliographical databases, and were included in the meta-analysis. Most studies examined the effects of cognitive behavior therapy (CBT). The majority of studies used waiting lists as control condition. The pooled effect of the 38 comparisons (from 28 studies) of psychotherapy versus a control group was large (g=0.84; 95% CI: 0.71-0.97) with low to moderate heterogeneity. The effects based on self-report measures were somewhat lower than those based on clinician-rated instruments. The effects on depression were also large (g=0.71; 95% CI: 0.59-0.82). There were some indications for publication bias. The number of studies comparing CBT with other psychotherapies (e.g., applied relaxation) or pharmacotherapy was too small to draw conclusions about comparative effectiveness or the long-term effects. There were some indications that CBT was also effective at follow-up and that CBT was more effective than applied relaxation in the longer term. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Refined generalized multiscale entropy analysis for physiological signals

    Science.gov (United States)

    Liu, Yunxiao; Lin, Youfang; Wang, Jing; Shang, Pengjian

    2018-01-01

    Multiscale entropy analysis has become a prevalent complexity measurement and been successfully applied in various fields. However, it only takes into account the information of mean values (first moment) in coarse-graining procedure. Then generalized multiscale entropy (MSEn) considering higher moments to coarse-grain a time series was proposed and MSEσ2 has been implemented. However, the MSEσ2 sometimes may yield an imprecise estimation of entropy or undefined entropy, and reduce statistical reliability of sample entropy estimation as scale factor increases. For this purpose, we developed the refined model, RMSEσ2, to improve MSEσ2. Simulations on both white noise and 1 / f noise show that RMSEσ2 provides higher entropy reliability and reduces the occurrence of undefined entropy, especially suitable for short time series. Besides, we discuss the effect on RMSEσ2 analysis from outliers, data loss and other concepts in signal processing. We apply the proposed model to evaluate the complexity of heartbeat interval time series derived from healthy young and elderly subjects, patients with congestive heart failure and patients with atrial fibrillation respectively, compared to several popular complexity metrics. The results demonstrate that RMSEσ2 measured complexity (a) decreases with aging and diseases, and (b) gives significant discrimination between different physiological/pathological states, which may facilitate clinical application.

  18. SNAP: A General Purpose Network Analysis and Graph Mining Library

    Science.gov (United States)

    Leskovec, Jure; Sosič, Rok

    2016-01-01

    Large networks are becoming a widely used abstraction for studying complex systems in a broad set of disciplines, ranging from social network analysis to molecular biology and neuroscience. Despite an increasing need to analyze and manipulate large networks, only a limited number of tools are available for this task. Here, we describe Stanford Network Analysis Platform (SNAP), a general-purpose, high-performance system that provides easy to use, high-level operations for analysis and manipulation of large networks. We present SNAP functionality, describe its implementational details, and give performance benchmarks. SNAP has been developed for single big-memory machines and it balances the trade-off between maximum performance, compact in-memory graph representation, and the ability to handle dynamic graphs where nodes and edges are being added or removed over time. SNAP can process massive networks with hundreds of millions of nodes and billions of edges. SNAP offers over 140 different graph algorithms that can efficiently manipulate large graphs, calculate structural properties, generate regular and random graphs, and handle attributes and meta-data on nodes and edges. Besides being able to handle large graphs, an additional strength of SNAP is that networks and their attributes are fully dynamic, they can be modified during the computation at low cost. SNAP is provided as an open source library in C++ as well as a module in Python. We also describe the Stanford Large Network Dataset, a set of social and information real-world networks and datasets, which we make publicly available. The collection is a complementary resource to our SNAP software and is widely used for development and benchmarking of graph analytics algorithms. PMID:28344853

  19. SNAP: A General Purpose Network Analysis and Graph Mining Library.

    Science.gov (United States)

    Leskovec, Jure; Sosič, Rok

    2016-10-01

    Large networks are becoming a widely used abstraction for studying complex systems in a broad set of disciplines, ranging from social network analysis to molecular biology and neuroscience. Despite an increasing need to analyze and manipulate large networks, only a limited number of tools are available for this task. Here, we describe Stanford Network Analysis Platform (SNAP), a general-purpose, high-performance system that provides easy to use, high-level operations for analysis and manipulation of large networks. We present SNAP functionality, describe its implementational details, and give performance benchmarks. SNAP has been developed for single big-memory machines and it balances the trade-off between maximum performance, compact in-memory graph representation, and the ability to handle dynamic graphs where nodes and edges are being added or removed over time. SNAP can process massive networks with hundreds of millions of nodes and billions of edges. SNAP offers over 140 different graph algorithms that can efficiently manipulate large graphs, calculate structural properties, generate regular and random graphs, and handle attributes and meta-data on nodes and edges. Besides being able to handle large graphs, an additional strength of SNAP is that networks and their attributes are fully dynamic, they can be modified during the computation at low cost. SNAP is provided as an open source library in C++ as well as a module in Python. We also describe the Stanford Large Network Dataset, a set of social and information real-world networks and datasets, which we make publicly available. The collection is a complementary resource to our SNAP software and is widely used for development and benchmarking of graph analytics algorithms.

  20. Histerectomía total abdominal frente a histerectomía mínimamente invasiva: revisión sistemática y metaanálisis Total abdominal hysterectomy versus minimal-invasive hysterectomy: a systemic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Felipe Jorge Aragón Palmero

    2011-03-01

    three types of hysterectomies are used: the vaginal hysterectomy and the minimal-invasive hysterectomy (MIH. The objective of present research was to compare the MIH and the total abdominal hysterectomy (TAH in women presenting with benign uterine diseases. METHODS. A systemic review was made and a meta-analysis from the following databases: MEDLINE, EBSCO HOST AND The Cochrane Central Register of Controlled Trials. Only the controlled and randomized studies were selected. The data of all studies were combined and also the relative risk (RR with a 95% CI was used with the Mantel-Haenszel method as an effect measure for dichotomy variables. For the analysis of continuing variables the mean difference was used. In all the comparisons performed the results were obtained with the fix effect and randomized forms. RESULTS. A total of 53 transoperative complications were registered in the MIH hysterectomy versus 17 in the TAH group (RR: 1,78; 95% CI: 1,04-3.05. Postoperative complications evolved in a similar way in both groups without significant differences from the statistical point of view. The blood losses, the hospital stay and the patient's reincorporation to usual and work activities were lesser in the laparoscopy group; however, the operative time is higher when it is compared with TAH (mean difference: 37,36; 95% CI: 34,36-39,93. CONCLUSIONS. Both techniques have advantages and disadvantages. The indication of MIH must to be individualized according to the clinical situation of each patient and these not to be performed in those centers without a properly trained surgical staff and with experience in advanced minimal invasive surgery.

  1. LSENS - GENERAL CHEMICAL KINETICS AND SENSITIVITY ANALYSIS CODE

    Science.gov (United States)

    Bittker, D. A.

    1994-01-01

    LSENS has been developed for solving complex, homogeneous, gas-phase, chemical kinetics problems. The motivation for the development of this program is the continuing interest in developing detailed chemical reaction mechanisms for complex reactions such as the combustion of fuels and pollutant formation and destruction. A reaction mechanism is the set of all elementary chemical reactions that are required to describe the process of interest. Mathematical descriptions of chemical kinetics problems constitute sets of coupled, nonlinear, first-order ordinary differential equations (ODEs). The number of ODEs can be very large because of the numerous chemical species involved in the reaction mechanism. Further complicating the situation are the many simultaneous reactions needed to describe the chemical kinetics of practical fuels. For example, the mechanism describing the oxidation of the simplest hydrocarbon fuel, methane, involves over 25 species participating in nearly 100 elementary reaction steps. Validating a chemical reaction mechanism requires repetitive solutions of the governing ODEs for a variety of reaction conditions. Analytical solutions to the systems of ODEs describing chemistry are not possible, except for the simplest cases, which are of little or no practical value. Consequently, there is a need for fast and reliable numerical solution techniques for chemical kinetics problems. In addition to solving the ODEs describing chemical kinetics, it is often necessary to know what effects variations in either initial condition values or chemical reaction mechanism parameters have on the solution. Such a need arises in the development of reaction mechanisms from experimental data. The rate coefficients are often not known with great precision and in general, the experimental data are not sufficiently detailed to accurately estimate the rate coefficient parameters. The development of a reaction mechanism is facilitated by a systematic sensitivity analysis

  2. Fluoroquinolone Sequential Therapy for Helicobacter pylori: A Meta-analysis.

    Science.gov (United States)

    Kale-Pradhan, Pramodini B; Mihaescu, Anela; Wilhelm, Sheila M

    2015-08-01

    As resistance of Helicobacter pylori to standard first-line therapy is increasing globally, alternative treatment regimens, such as a fluoroquinolone-based sequential regimen, have been explored. The objective of this meta-analysis was to compare the efficacy of fluoroquinolone-based sequential therapy with standard first-line treatment for H. pylori infection. Meta-analysis of six randomized controlled trials. A total of 738 H. pylori-infected, treatment-naive adults who received fluoroquinolone-based sequential therapy (5-7 days of a proton pump inhibitor [PPI] and amoxicillin therapy followed by 5-7 days of a PPI, a fluoroquinolone, and metronidazole or tinidazole or furazolidone therapy) and 733 H. pylori-infected, treatment-naive adults who received guideline-recommended, first-line therapy with standard triple therapy (7-14 days of a PPI plus amoxicillin and clarithromycin) or standard sequential therapy (5 days of a PPI plus amoxicillin, followed by an additional 5 days of triple therapy consisting of a PPI, clarithromycin, and metronidazole or tinidazole). A systematic literature search of the MEDLINE, PubMed, and Cochrane Central Register of Controlled Trials databases (from inception through January 2015) was conducted to identify randomized controlled trials that compared fluoroquinolone-based sequential therapy with guideline-recommended, first-line treatment regimens in H. pylori-infected, treatment-naive adults. All selected trials confirmed H. pylori infection prior to treatment as well as post-treatment eradication. A meta-analysis was performed by using Review Manager 5.2. Treatment effect was determined with a random-effects model by using the Mantel-Haenszel method and was reported as a risk ratio (RR) with 95% confidence interval (CI). In the six randomized controlled trials that met the inclusion criteria, 648 (87.8%) of 738 patients receiving fluoroquinolone-based sequential therapy and 521 (71.1%) of 733 patients receiving standard

  3. Sampling in forests for radionuclide analysis. General and practical guidance

    Energy Technology Data Exchange (ETDEWEB)

    Aro, Lasse (Finnish Forest Research Inst. (METLA) (Finland)); Plamboeck, Agneta H. (Swedish Defence Research Agency (FOI) (Sweden)); Rantavaara, Aino; Vetikko, Virve (Radiation and Nuclear Safety Authority (STUK) (Finland)); Straalberg, Elisabeth (Inst. Energy Technology (IFE) (Norway))

    2009-01-15

    The NKS project FOREST was established to prepare a guide for sampling in forest ecosystems for radionuclide analysis. The aim of this guide is to improve the reliability of datasets generated in future studies by promoting the use of consistent, recommended practices, thorough documentation of field sampling regimes and robust preparation of samples from the forest ecosystem. The guide covers general aims of sampling, the description of major compartments of the forest ecosystem and outlines key factors to consider when planning sampling campaigns for radioecological field studies in forests. Recommended and known sampling methods for various sample types are also compiled and presented. The guide focuses on sampling practices that are applicable in various types of boreal forests, robust descriptions of sampling sites, and documentation of the origin and details of individual samples. The guide is intended for scientists, students, forestry experts and technicians who appreciate the need to use sound sampling procedures in forest radioecological projects. The guide will hopefully encourage readers to participate in field studies and sampling campaigns, using robust techniques, thereby fostering competence in sampling. (au)

  4. Sampling in forests for radionuclide analysis. General and practical guidance

    International Nuclear Information System (INIS)

    Aro, Lasse; Plamboeck, Agneta H.; Rantavaara, Aino; Vetikko, Virve; Straelberg, Elisabeth

    2009-01-01

    The NKS project FOREST was established to prepare a guide for sampling in forest ecosystems for radionuclide analysis. The aim of this guide is to improve the reliability of datasets generated in future studies by promoting the use of consistent, recommended practices, thorough documentation of field sampling regimes and robust preparation of samples from the forest ecosystem. The guide covers general aims of sampling, the description of major compartments of the forest ecosystem and outlines key factors to consider when planning sampling campaigns for radioecological field studies in forests. Recommended and known sampling methods for various sample types are also compiled and presented. The guide focuses on sampling practices that are applicable in various types of boreal forests, robust descriptions of sampling sites, and documentation of the origin and details of individual samples. The guide is intended for scientists, students, forestry experts and technicians who appreciate the need to use sound sampling procedures in forest radioecological projects. The guide will hopefully encourage readers to participate in field studies and sampling campaigns, using robust techniques, thereby fostering competence in sampling. (au)

  5. Development of ocular hypertension secondary to tamponade with light versus heavy silicone oil: A systematic review

    Directory of Open Access Journals (Sweden)

    Vito Romano

    2015-01-01

    Full Text Available Aim: The intraocular silicone oil (SO tamponades used in the treatment of retinal detachment (RD have been associated with a difference ocular hypertension (OH rate. To clarify, if this complication was associated to use of standard SO (SSO versus heavy SO (HSO, we performed a systematic review and meta-analysis of comparative study between two kind of SO (standard or light vs. heavy for the treatment of RD and macular hole, without restriction to study design. Materials and Methods: The methodological quality of two randomized clinical trials (RCTs were evaluated using the criteria given in the Cochrane Handbook for Systematic Reviews of Intervention, while three non-RCTs were assessed with the Newcastle-Ottawa Scale and Strengthening the Reporting of Observational Studies in Epidemiology checklists. We calculated Mantel-Haenszel risk ratio (RR with 95% confidence intervals (95% CIs. The primary outcome was the rate of patients with OH treated with SSO compared to HSO. Results: There were a higher number of rates of OH in HSO compared to SSO. This difference was statistically significant with the fixed effect model (Mantel-Haenszel RR; 1.55; 95% CI, 1.06-2.28; P = 0.02 while there was not significative difference with the random effect model (Mantel-Haenszel RR; 1.51; 95% CI, 0.98-2.33; P = 0.06. Conclusion: We noted a trend that points out a higher OH rate in HSO group compared to SSO, but this finding, due to the small size and variable design of studies, needs to be confirmed in well-designed and large size RCTs.

  6. Surgical timing of the orbital "blowout" fracture

    DEFF Research Database (Denmark)

    Damgaard, Olaf Ehlers; Larsen, Christian Grønhøj; Felding, Ulrik Ascanius

    2016-01-01

    Objective: The orbital blowout fracture is a common facial injury, carrying with it a risk of visual impairment and undesirable cosmetic results unless treated properly. Optimal timing of the surgical treatment is still a matter of debate. We set out to determine whether a meta-analysis would bring......). Patients were evaluated for diplopia and enophthalmos.  Review Methods: We followed the statements of PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses). Pooled odds ratios were estimated with the fixed effects method of Mantel-Haenszel.  Results: We identified 5 studies...

  7. Admixture analysis of age of onset in generalized anxiety disorder.

    Science.gov (United States)

    Rhebergen, Didi; Aderka, Idan M; van der Steenstraten, Ira M; van Balkom, Anton J L M; van Oppen, Patricia; Stek, Max L; Comijs, Hannie C; Batelaan, Neeltje M

    2017-08-01

    Age of onset is a marker of clinically relevant subtypes in various medical and psychiatric disorders. Past research has also reported that age of onset in generalized anxiety disorder (GAD) is clinically significant; but, in research to date, arbitrary cut-off ages have been used. In the present study, admixture analysis was used to determine the best fitting model for age of onset distribution in GAD. Data were derived from 459 adults with a diagnosis of GAD who took part in the Netherlands Study of Depression and Anxiety (NESDA). Associations between age of onset subtypes, identified by admixture analysis, and sociodemographic, clinical, and vulnerability factors were examined using univariate tests and multivariate logistic regression analyses. Two age of onset distributions were identified: an early-onset group (24 years of age and younger) and a late-onset group (greater than 24 years of age). Multivariate analysis revealed that early-onset GAD was associated with female gender (OR 2.1 (95%CI 1.4-3.2)), higher education (OR 1.1 (95%CI 1.0-1.2)), and higher neuroticism (OR 1.4 (95%CI 1.1-1.7)), while late-onset GAD was associated with physical illnesses (OR 1.3 (95%CI 1.1-1.7)). Study limitations include the possibility of recall bias given that age of onset was assessed retrospectively, and an inability to detect a possible very-late-onset GAD subtype. Collectively, the results of the study indicate that GAD is characterized by a bimodal age of onset distribution with an objectively determined early cut-off at 24 years of age. Early-onset GAD is associated with unique factors that may contribute to its aetiology; but, it does not constitute a more severe subtype compared to late-onset GAD. Future research should use 24 years of age as the cut-off for early-onset GAD to when examining the clinical relevance of age of onset for treatment efficacy and illness course. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Practical likelihood analysis for spatial generalized linear mixed models

    DEFF Research Database (Denmark)

    Bonat, W. H.; Ribeiro, Paulo Justiniano

    2016-01-01

    , respectively, examples of binomial and count datasets modeled by spatial generalized linear mixed models. Our results show that the Laplace approximation provides similar estimates to Markov Chain Monte Carlo likelihood, Monte Carlo expectation maximization, and modified Laplace approximation. Some advantages...

  9. Analysis of Financial Ratio to Distinguish Indonesia Joint Venture General Insurance Company Performance using Discriminant Analysis

    Directory of Open Access Journals (Sweden)

    Subiakto Soekarno

    2012-01-01

    Full Text Available Insurance industry stands as a service business that plays a significant role in Indonesiaeconomical condition. The development of insurance industry in Indonesia, both of generalinsurance and life insurance, has increased very fast. The general insurance industry itselfdivided into two major players which are local private company and Joint Venture Company.Lately, the use of statistical techniques and financial ratios models to asses financial institutionsuch as insurance company have been used as one of the appropriate combination inpredicting the performance of an industry. This research aims to distinguish between JointVenture General Insurance Companies that have a good performance and those who are lessperforming well using Discriminant Analysis. Further, the findings led that DiscriminantAnalysis is able to distinguish Joint Venture General Insurance Companies that have a goodperformance and those who are not performing well. There are also six ratios which are RBC,Technical Reserve to Investment Ratio, Debt Ratio, Return on Equity, Loss Ratio, and ExpenseRatio that stand as the most influential ratios to distinguish the performance of joint venturegeneral insurance companies. In addition, the result suggest business people to be concernedtoward those six ratios, to increase their companies’ performance.Key words: general insurance, financial ratio, discriminant analysis

  10. Analysis of generalized Schwarz alternating procedure for domain decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Engquist, B.; Zhao, Hongkai [Univ. of California, Los Angeles, CA (United States)

    1996-12-31

    The Schwartz alternating method(SAM) is the theoretical basis for domain decomposition which itself is a powerful tool both for parallel computation and for computing in complicated domains. The convergence rate of the classical SAM is very sensitive to the overlapping size between each subdomain, which is not desirable for most applications. We propose a generalized SAM procedure which is an extension of the modified SAM proposed by P.-L. Lions. Instead of using only Dirichlet data at the artificial boundary between subdomains, we take a convex combination of u and {partial_derivative}u/{partial_derivative}n, i.e. {partial_derivative}u/{partial_derivative}n + {Lambda}u, where {Lambda} is some {open_quotes}positive{close_quotes} operator. Convergence of the modified SAM without overlapping in a quite general setting has been proven by P.-L.Lions using delicate energy estimates. The important questions remain for the generalized SAM. (1) What is the most essential mechanism for convergence without overlapping? (2) Given the partial differential equation, what is the best choice for the positive operator {Lambda}? (3) In the overlapping case, is the generalized SAM superior to the classical SAM? (4) What is the convergence rate and what does it depend on? (5) Numerically can we obtain an easy to implement operator {Lambda} such that the convergence is independent of the mesh size. To analyze the convergence of the generalized SAM we focus, for simplicity, on the Poisson equation for two typical geometry in two subdomain case.

  11. General-equilibrium approach to energy/environmental economic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Groncki, P J

    1978-08-01

    This paper presents a brief critique of the use of fixed-coefficient input-output models for use in energy/environmental modeling systems, a shortcoming of input-output models that has been often been noted. Then, given the existence of aggregate, general-equilibrium, variable-coefficient growth models, a methodology is presented for using this information to adjust a recent disaggregated input-output table. This methodology takes into account all of the general-equilibrium aspects of the aggregate model in making the changes in the disaggregate model. The use of various weighting schemes and the implicit technological change biases they embody are examined. The methodology is being tested on historical tables for the United States, and preliminary results are discussed. This methodology's ability to fully capture the general-equilibrium nature of the economy should enhance the usefulness of input-output models in energy/environmental modeling systems.

  12. Signal Analysis by Generalized Hilbert Transforms on the Unit Sphere

    International Nuclear Information System (INIS)

    Wietzke, Lennart; Fleischmann, Oliver; Sommer, Gerald

    2008-01-01

    In 1D signal processing local energy and phase can be determined by the analytic signal. Local energy, phase and orientation of 2D signals can be analyzed by the monogenic signal for all i(ntrinsic)1D signals in an rotational invariant way by the generalized Hilbert transform. In order to analyze both i1D and i2D signals in one framework the main idea of this contribution is to lift up 2D signals to the higher dimensional conformal space in which the original signal can be analyzed with more degrees of freedom by the generalized Hilbert transform on the unit sphere. An appropriate embedding of 2D signals on the unit sphere results in an extended feature space spanned by local energy, phase, orientation/direction and curvature. In contrast to classical differential geometry, local curvature can now be determined by the generalized Hilbert transform in monogenic scale space without any derivatives.

  13. Using general-purpose compression algorithms for music analysis

    DEFF Research Database (Denmark)

    Louboutin, Corentin; Meredith, David

    2016-01-01

    General-purpose compression algorithms encode files as dictionaries of substrings with the positions of these strings’ occurrences. We hypothesized that such algorithms could be used for pattern discovery in music. We compared LZ77, LZ78, Burrows–Wheeler and COSIATEC on classifying folk song...... melodies. A novel method was used, combining multiple viewpoints, the k-nearest-neighbour algorithm and a novel distance metric, corpus compression distance. Using single viewpoints, COSIATEC outperformed the general-purpose compressors, with a classification success rate of 85% on this task. However...

  14. Municipal solid waste management problems: an applied general equilibrium analysis

    NARCIS (Netherlands)

    Bartelings, H.

    2003-01-01

    Keywords: Environmental policy; General equilibrium modeling; Negishi format; Waste management policies; Market distortions.

    About 40% of the entire budget spent on environmental problems in the

  15. The analysis of singletons in generalized birthday problems

    NARCIS (Netherlands)

    Koot, M.R.; Mandjes, M.R.H.

    2012-01-01

    This paper describes techniques to characterize the number of singletons in the setting of the generalized birthday problem, that is, the birthday problem in which the birthdays are non-uniformly distributed over the year. Approximations for the mean and variance presented which explicitly indicate

  16. Nonlinear Analysis of the Generalized Thermo-Magnetodynamic Problem

    Czech Academy of Sciences Publication Activity Database

    Nedoma, Jiří

    1995-01-01

    Roč. 63, 1/3 (1995), s. 393-402 ISSN 0377-0427. [Modelling'94. Prague, 29.08.1994-02.09.1994] Grant - others:COPERNICUS(XE) 94-00820 Keywords : generalized magnetodynamics * partial differential equations * variational inequalities * viscoplasticity * geodynamics * magnetic field of planets * astrophysics Impact factor: 0.373, year: 1995

  17. An applied general equilibrium model for Dutch agribusiness policy analysis

    NARCIS (Netherlands)

    Peerlings, J.

    1993-01-01

    The purpose of this thesis was to develop a basic static applied general equilibrium (AGE) model to analyse the effects of agricultural policy changes on Dutch agribusiness. In particular the effects on inter-industry transactions, factor demand, income, and trade are of

  18. Hierarchical Generalized Linear Models for the Analysis of Judge Ratings

    Science.gov (United States)

    Muckle, Timothy J.; Karabatsos, George

    2009-01-01

    It is known that the Rasch model is a special two-level hierarchical generalized linear model (HGLM). This article demonstrates that the many-faceted Rasch model (MFRM) is also a special case of the two-level HGLM, with a random intercept representing examinee ability on a test, and fixed effects for the test items, judges, and possibly other…

  19. Global Analysis of General Trade and Operational Licensing

    OpenAIRE

    World Bank; International Finance Corporation; Multilateral Investment Guarantee Agency

    2012-01-01

    This paper examines the general purpose licensing imposed by central or local authorities, and the need to eliminate unnecessary licensing regulations imposed on businesses. This paper does not address the issue of reform of sector-specific or professional licensing regulation, but provides criteria and tools for identifying unnecessary licensing regulations, and their elimination or, in s...

  20. Meta-analysis in a nutshell: Techniques and general findings

    DEFF Research Database (Denmark)

    Paldam, Martin

    2015-01-01

    The purpose of this article is to introduce the technique and main findings of meta-analysis to the reader, who is unfamiliar with the field and has the usual objections. A meta-analysis is a quantitative survey of a literature reporting estimates of the same parameter. The funnel showing...

  1. Generalized Aliasing as a Basis for Program Analysis Tools

    National Research Council Canada - National Science Library

    O'Callahan, Robert

    2000-01-01

    .... This dissertation describes the design of a system, Ajax, that addresses this problem by using semantics-based program analysis as the basis for a number of different tools to aid Java programmers...

  2. Analysis and suggestions on standard system for general nuclear instruments

    International Nuclear Information System (INIS)

    Xiong Zhenglong

    1999-08-01

    The standard system has been analyzed and researched for the general nuclear instruments and propounded following suggestions against the problems in standard's system: seriously adopting the international standards and recommending Chinese standards toward the world; appropriately regularizing the system's frame and the standard's configurations to make it more scientific, perfect and applicable; enhancing the construction of technical and basic standards, promoting the standardization of entire nuclear instruments; replenishing the standards of the testing methods and straightening out the standard's level, further completing the standard's system. In short, all of them are to enhance quality, readability and maneuverability of standards, to exert sufficiently the effects of standards

  3. F-Granulation Generalized Rough Entropy and Image Analysis

    Science.gov (United States)

    Pal, Sankar K.

    2012-12-01

    Role of f-granulation in handling uncertainty in machine intelligence and its significance as a facet of natural computation are discussed. Its modeling through judicious integration of rough and fuzzy sets is explained. Several tasks like case generation, clustering, classification and segmentation are described in rough-fuzzy framework demonstrating the role of f-granulation and the resulting merits. A definition of generalized rough sets is given considering both the set and granules as crisp and/or fuzzy. Based on that new entropy measures are defined using exponential and logarithmic gain functions. The superiority of rough-fuzzy integration, in terms of performance and computation time, is illustrated for the tasks of case mining in large data sets, segmenting brain MR images, and classifying remotely sensed images as examples. Neighbourhood rough sets are capable of better dimensionality reduction. The effect of fuzzy-granules and generalizations in rough sets is demonstrated for image segmentation. The article includes some of the results published elsewhere.

  4. Generalized linear mixed model for segregation distortion analysis.

    Science.gov (United States)

    Zhan, Haimao; Xu, Shizhong

    2011-11-11

    Segregation distortion is a phenomenon that the observed genotypic frequencies of a locus fall outside the expected Mendelian segregation ratio. The main cause of segregation distortion is viability selection on linked marker loci. These viability selection loci can be mapped using genome-wide marker information. We developed a generalized linear mixed model (GLMM) under the liability model to jointly map all viability selection loci of the genome. Using a hierarchical generalized linear mixed model, we can handle the number of loci several times larger than the sample size. We used a dataset from an F(2) mouse family derived from the cross of two inbred lines to test the model and detected a major segregation distortion locus contributing 75% of the variance of the underlying liability. Replicated simulation experiments confirm that the power of viability locus detection is high and the false positive rate is low. Not only can the method be used to detect segregation distortion loci, but also used for mapping quantitative trait loci of disease traits using case only data in humans and selected populations in plants and animals.

  5. 1998 BUSINESS ANALYSIS SUMMARY FOR GENERAL LIVESTOCK FARMS

    OpenAIRE

    Nott, Sherrill B.; Hampton, Jonathon C.

    1999-01-01

    This report has three purposes: 1)to provide statistical information about the financial results on dairy farms during 1998; 2)to provide production costs for comparative analysis and forward planning; and 3)to provide information on the trends in resource use, income and costs during the last few years.

  6. Seismic risk analysis for General Electric Plutonium Facility, Pleasanton, California

    International Nuclear Information System (INIS)

    1978-01-01

    This report presents the results of a seismic risk analysis that focuses on all possible sources of seismic activity, with the exception of the postulated Verona Fault. The best estimate curve indicates that the Vallecitos facility will experience 30% g with a return period of roughly 130 years and 60% g with a return period of roughly 700 years

  7. A Generalized Lanczos-QR Technique for Structural Analysis

    DEFF Research Database (Denmark)

    Vissing, S.

    . Alternatively, in a stability analysis, tangent stiffness and geometric stiffness matrices are introduced into an eigenvalue problem used to determine possible bifurcation points. The common basis for these types of problems is that the matrix equation describing the problem contains two real, symmetric...

  8. A GENERALIZATION OF TRADITIONAL KANO MODEL FOR CUSTOMER REQUIREMENTS ANALYSIS

    Directory of Open Access Journals (Sweden)

    Renáta Turisová

    2015-07-01

    Full Text Available Purpose: The theory of attractiveness determines the relationship between the technically achieved and customer perceived quality of product attributes. The most frequently used approach in the theory of attractiveness is the implementation of Kano‘s model. There exist a lot of generalizations of that model which take into consideration various aspects and approaches focused on understanding the customer preferences and identification of his priorities for a selling  product. The aim of this article is to outline another possible generalization of Kano‘s model.Methodology/Approach: The traditional Kano’s model captures the nonlinear relationship between reached attributes of quality and customer requirements. The individual attributes of quality are divided into three main categories: must-be, one-dimensional, attractive quality and into two side categories: indifferent and reverse quality. The well selling product has to contain the must-be attribute. It should contain as many one-dimensional attributes as possible. If there are also supplementary attractive attributes, it means that attractiveness of the entire product, from the viewpoint of the customer, nonlinearly sharply rises what has a direct positive impact on a decision of potential customer when purchasing the product. In this article, we show that inclusion of individual quality attributes of a product to the mentioned categories depends, among other things, also on costs on life cycle of the product, respectively on a price of the product on the market.Findings: In practice, we are often encountering the inclusion of products into different price categories: lower, middle and upper class. For a certain type of products the category is either directly declared by a producer (especially in automotive industry, or is determined by a customer by means of assessment of available market prices. To each of those groups of a products different customer expectations can be assigned

  9. General Analysis of Timoshenko Beams on Elastic Foundation

    Directory of Open Access Journals (Sweden)

    S. Abohadima

    2015-01-01

    Full Text Available General analytical solutions for stability, free and forced vibration of an axially loaded Timoshenko beam resting on a two-parameter foundation subjected to nonuniform lateral excitation are obtained using recursive differentiation method (RDM. Elastic restraints for rotation and translation are assumed at the beam ends to investigate the effect of support weakening on the beam behavior. However, the effects of rotational inertia and shear stress induced from the axial load are considered. The obtained solutions are verified first and then used to investigate the significance of different parameters on the beam behavior. In addition, solutions of forced vibration are analyzed to highlight the effects of excitation nonhomogeneity on the beam behavior.

  10. Geal: A general program for the analysis of alpha spectra

    International Nuclear Information System (INIS)

    Garcia-Torano, E.; Acena Barrenechea, M.L.

    1978-01-01

    A computing program for analysis and representation of alpha spectra obtained with surface barrier detectors is described. Several methods for fitting spectra are studied. A monoenergetic line or a doublet previously fitted has been used as a standard for the analyses of all kind of spectra. Some examples of application as well as a list of the program are shown. The program has been written in Fortran V language. (author)

  11. 75 FR 52587 - 2009 Fatality Analysis Reporting System (FARS)/National Automotive Sampling System General...

    Science.gov (United States)

    2010-08-26

    ... National Highway Traffic Safety Administration 2009 Fatality Analysis Reporting System (FARS)/National Automotive Sampling System General Estimates System (NASS GES) Updates AGENCY: National Highway Traffic... Traffic Safety Administration (NHTSA)--2009 Fatality Analysis Reporting System (FARS) & National...

  12. Analysis and design of generalized BICM-T system

    KAUST Repository

    Malik, Muhammad Talha

    2014-09-01

    The performance of bit-interleaved coded modulation (BICM) using convolutional codes in nonfading channels can be significantly improved if the coded bits are not interleaved at all. This particular BICM system is referred to as BICM trivial (BICM-T). In this paper, we analyze a generalized BICM-T system that uses a nonequally spaced signal constellation in conjunction with a bit-level multiplexer in an additive white Gaussian noise (AWGN) channel. As such, one can exploit the full benefit of BICM-T by jointly optimizing different system modules to further improve its performance. We also investigate the performance of the considered BICM-T system in the Gaussian mixture noise (GMN) channel because of its practical importance. The presented numerical results show that an optimized BICM-T system can offer gains up to 1.5 dB over a non-optimized BICM-T system in the AWGN channel for a target bit error rate of $10^{-6}$. The presented results for the GMN channel interestingly reveal that if the strength of the impulsive noise component, i.e., the noise component due to some ambient phenomenon in the GMN, is below a certain threshold level, then the BICM-T system performs significantly better as compared to traditional BICM system.

  13. Analysis of general specifications for nuclear facilities environmental monitoring vehicles

    International Nuclear Information System (INIS)

    Xu Xiaowei

    2014-01-01

    At present, with the nuclear energy more increasingly extensive application, the continuous stable radiation monitoring has become the focus of the public attention. The main purpose of the environmental monitoring vehicle for the continuous monitoring of the environmental radiation dose rate and the radionuclides concentration in the medium around nuclear facilities is that the environmental radiation level and the radioactive nuclides activity in the environment medium are measured. The radioactive pollution levels, the scope contaminated and the trends of the pollution accumulation are found out. The change trends for the pollution are observed and the monitoring results are explained. The domestic demand of the environmental monitoring for the nuclear facilities is shown in this report. The changes and demands of the routine environmental monitoring and the nuclear emergency monitoring are researched. The revision opinions for EJ/T 981-1995 General specifications for nuclear facilities environmental monitoring vehicles are put forward. The purpose is to regulate domestic environmental monitoring vehicle technical criterion. The criterion makes it better able to adapt and serve the environmental monitoring for nuclear facilities. The technical guarantee is provided for the environmental monitoring of the nuclear facilities. (authors)

  14. Quaternion analysis of generalized electromagnetic fields in chiral media

    International Nuclear Information System (INIS)

    Bisht, P. S. . Email. ps_bisht123@rediffmail.com

    2007-01-01

    The time dependent Maxwell's equations in presence of electric and magnetic charges has been developed in chiral media and the solutions for the classical problem are obtained in unique, simple and consistent manner. The quaternionic reformulation of generalized electromagnetic fields in chiral media has also been developed in compact and consistent way. Simulation of neutron backscattering process applied to organic material detection. Forero Martinez, Nancy Carolina; Cristancho, Fernando (Nuclear Physics Group, Universidad Nacional de Colombia, Bogota D.C. (Colombia)) Abstract Atomic and nuclear physics based sensors might offer new possibilities in de-mining. There is a particular interest in the possibility of using neutrons for the non-intrusive detection of hidden contraband, explosives or illicit drugs. The Neutron Backscattering Technique, based on the detection of the produced thermal neutrons, is known to be a useful tool to detect hidden explosives which present an elevated concentration of light elements (H, C, N, O). In this way we present the simulated results using the program package Geant4. Different variables were modified including the soil composition and the studied materials. (Author)

  15. Generalized multiplicative error models: Asymptotic inference and empirical analysis

    Science.gov (United States)

    Li, Qian

    This dissertation consists of two parts. The first part focuses on extended Multiplicative Error Models (MEM) that include two extreme cases for nonnegative series. These extreme cases are common phenomena in high-frequency financial time series. The Location MEM(p,q) model incorporates a location parameter so that the series are required to have positive lower bounds. The estimator for the location parameter turns out to be the minimum of all the observations and is shown to be consistent. The second case captures the nontrivial fraction of zero outcomes feature in a series and combines a so-called Zero-Augmented general F distribution with linear MEM(p,q). Under certain strict stationary and moment conditions, we establish a consistency and asymptotic normality of the semiparametric estimation for these two new models. The second part of this dissertation examines the differences and similarities between trades in the home market and trades in the foreign market of cross-listed stocks. We exploit the multiplicative framework to model trading duration, volume per trade and price volatility for Canadian shares that are cross-listed in the New York Stock Exchange (NYSE) and the Toronto Stock Exchange (TSX). We explore the clustering effect, interaction between trading variables, and the time needed for price equilibrium after a perturbation for each market. The clustering effect is studied through the use of univariate MEM(1,1) on each variable, while the interactions among duration, volume and price volatility are captured by a multivariate system of MEM(p,q). After estimating these models by a standard QMLE procedure, we exploit the Impulse Response function to compute the calendar time for a perturbation in these variables to be absorbed into price variance, and use common statistical tests to identify the difference between the two markets in each aspect. These differences are of considerable interest to traders, stock exchanges and policy makers.

  16. General metabolism of Laribacter hongkongensis: a genome-wide analysis

    Directory of Open Access Journals (Sweden)

    Curreem Shirly O

    2011-04-01

    Full Text Available Abstract Background Laribacter hongkongensis is associated with community-acquired gastroenteritis and traveler's diarrhea. In this study, we performed an in-depth annotation of the genes and pathways of the general metabolism of L. hongkongensis and correlated them with its phenotypic characteristics. Results The L. hongkongensis genome possesses the pentose phosphate and gluconeogenesis pathways and tricarboxylic acid and glyoxylate cycles, but incomplete Embden-Meyerhof-Parnas and Entner-Doudoroff pathways, in agreement with its asaccharolytic phenotype. It contains enzymes for biosynthesis and β-oxidation of saturated fatty acids, biosynthesis of all 20 universal amino acids and selenocysteine, the latter not observed in Neisseria gonorrhoeae, Neisseria meningitidis and Chromobacterium violaceum. The genome contains a variety of dehydrogenases, enabling it to utilize different substrates as electron donors. It encodes three terminal cytochrome oxidases for respiration using oxygen as the electron acceptor under aerobic and microaerophilic conditions and four reductases for respiration with alternative electron acceptors under anaerobic conditions. The presence of complete tetrathionate reductase operon may confer survival advantage in mammalian host in association with diarrhea. The genome contains CDSs for incorporating sulfur and nitrogen by sulfate assimilation, ammonia assimilation and nitrate reduction. The existence of both glutamate dehydrogenase and glutamine synthetase/glutamate synthase pathways suggests an importance of ammonia metabolism in the living environments that it may encounter. Conclusions The L. hongkongensis genome possesses a variety of genes and pathways for carbohydrate, amino acid and lipid metabolism, respiratory chain and sulfur and nitrogen metabolism. These allow the bacterium to utilize various substrates for energy production and survive in different environmental niches.

  17. A Generalized Framework for Non-Stationary Extreme Value Analysis

    Science.gov (United States)

    Ragno, E.; Cheng, L.; Sadegh, M.; AghaKouchak, A.

    2017-12-01

    Empirical trends in climate variables including precipitation, temperature, snow-water equivalent at regional to continental scales are evidence of changes in climate over time. The evolving climate conditions and human activity-related factors such as urbanization and population growth can exert further changes in weather and climate extremes. As a result, the scientific community faces an increasing demand for updated appraisal of the time-varying climate extremes. The purpose of this study is to offer a robust and flexible statistical tool for non-stationary extreme value analysis which can better characterize the severity and likelihood of extreme climatic variables. This is critical to ensure a more resilient environment in a changing climate. Following the positive feedback on the first version of Non-Stationary Extreme Value Analysis (NEVA) Toolbox by Cheng at al. 2014, we present an improved version, i.e. NEVA2.0. The upgraded version herein builds upon a newly-developed hybrid evolution Markov Chain Monte Carlo (MCMC) approach for numerical parameters estimation and uncertainty assessment. This addition leads to a more robust uncertainty estimates of return levels, return periods, and risks of climatic extremes under both stationary and non-stationary assumptions. Moreover, NEVA2.0 is flexible in incorporating any user-specified covariate other than the default time-covariate (e.g., CO2 emissions, large scale climatic oscillation patterns). The new feature will allow users to examine non-stationarity of extremes induced by physical conditions that underlie the extreme events (e.g. antecedent soil moisture deficit, large-scale climatic teleconnections, urbanization). In addition, the new version offers an option to generate stationary and/or non-stationary rainfall Intensity - Duration - Frequency (IDF) curves that are widely used for risk assessment and infrastructure design. Finally, a Graphical User Interface (GUI) of the package is provided, making NEVA

  18. A general sequence processing and analysis program for protein engineering.

    Science.gov (United States)

    Stafford, Ryan L; Zimmerman, Erik S; Hallam, Trevor J; Sato, Aaron K

    2014-10-27

    Protein engineering projects often amass numerous raw DNA sequences, but no readily available software combines sequence processing and activity correlation required for efficient lead identification. XLibraryDisplay is an open source program integrated into Microsoft Excel for Windows that automates batch sequence processing via a simple step-by-step, menu-driven graphical user interface. XLibraryDisplay accepts any DNA template which is used as a basis for trimming, filtering, translating, and aligning hundreds to thousands of sequences (raw, FASTA, or Phred PHD file formats). Key steps for library characterization through lead discovery are available including library composition analysis, filtering by experimental data, graphing and correlating to experimental data, alignment to structural data extracted from PDB files, and generation of PyMOL visualization scripts. Though larger data sets can be handled, the program is best suited for analyzing approximately 10 000 or fewer leads or naïve clones which have been characterized using Sanger sequencing and other experimental approaches. XLibraryDisplay can be downloaded for free from sourceforge.net/projects/xlibrarydisplay/ .

  19. Is education a determinant of knowledge about malaria among Indian tribal population?

    Science.gov (United States)

    Sharma, A K; Aggarwal, O P; Chaturvedi, S; Bhasin, S K

    2003-06-01

    Malaria is a major public health problem in tribal villages of India, where 8% of the country's population lives. Literacy level among tribal population is very low. This study aims to examine the relation between education status and knowledge about malaria among Indian tribal communities. 125 randomly selected tribal respondents from one tribal village each of 17 states were administered a close ended questionnaire by trained interviewers to assess their knowledge about various aspects of malaria. Effect of educational status on the level of knowledge was analyzed using chi square test. Stratified analysis was performed using Mantel Haenszel chi square test to eliminate gender bias. 2125 respondents', randomly selected from 17 tribal villages in as many states, findings were analyzed. Fifty seven percent male and 72% female respondents were illiterate. Only 2% respondents had college level education. Educated females were more knowledgeable than their male counterparts. Mantel Haenszel chi square analysis showed that educated respondents were more knowledgeable than the illiterates, after adjusting for sex of respondents. However, there was gross lack of knowledge regarding diagnosis and treatment of malaria and use of insecticides irrespective of gender and educational status. Improvement in literacy status of tribal population will help in increasing awareness about malaria. Opportunities for disseminating information about various aspects of malaria should be utilized during treatment of malaria cases by health workers.

  20. Efficacy and safety of linezolid in methicillin-resistant Staphylococcus aureus (MRSA) complicated skin and soft tissue infection (cSSTI): a meta-analysis.

    Science.gov (United States)

    Bounthavong, Mark; Hsu, Donald I

    2010-02-01

    To evaluate the clinical and microbiological outcomes of linezolid versus vancomycin in methicillin-resistant Staphylococcus aureus (MRSA) complicated skin and soft-tissue infection (cSSTI) using a meta-analysis. Clinical trials were identified using PubMed, the Cochrane Central Register of Controlled Trials, and the International Pharmaceutical Abstracts from inception to March 2009. Primary outcomes evaluated resolution of signs and symptoms of infection in clinically evaluable (CE) patients, and microbiological eradication in both the modified intent-to-treat (MITT) and MRSA evaluable (MRSA ME) patients. MITT patients had a culture-confirmed Gram-positive pathogen (S. aureus) at baseline. Secondary outcomes included mortality, adverse drug reactions (ADR), and discontinuation due to ADRs. The Mantel-Haenszel odds ratios (OR) with 95% confidence intervals (CI) were calculated using the fixed effects model based on the assumption that there was little to no heterogeneity between the studies in the primary analysis. Sensitivity analyses were performed for each outcome by removing the most weighted study. Five studies with a total of 2652 patients (1361/linezolid; 1291/vancomycin) were identified. Resolution of infection in CE patients (OR = 1.41; 95% CI: 1.03, 1.95) and MITT patients (OR = 1.91; 95% CI: 1.33, 2.76) favored the use of linezolid over vancomycin, but did not remain significant after sensitivity analyses (CE: OR = 1.29; 95% CI: 0.81, 2.05; MITT: OR = 1.73; 95% CI: 0.87, 3.41). Microbiological eradication in MRSA ME patients consistently favored the use of linezolid over vancomycin (OR = 2.90; 95% CI: 1.90, 4.41). No difference in mortality was observed between the two groups (OR = 1.17; 95% CI: 0.85, 1.62). Higher proportions of linezolid patients were found to have diarrhea (119/1361 vs. 52/1291), nausea (102/1361 vs. 46/1291) and thrombocytopenia (54/1121 vs. 8/1071), whereas a higher proportion of vancomycin patients were found to have renal

  1. Funcionamiento diferencial del item en la evaluación internacional PISA. Detección y comprensión. [Differential Item Functioning in the PISA Project: Detection and Understanding

    Directory of Open Access Journals (Sweden)

    Paula Elosua

    2006-08-01

    Full Text Available This report analyses the differential item functioning (DIF in the Programme for Indicators of Student Achievement PISA2000. The items studied are coming from the Reading Comprehension Test. We analyzed the released items from this year because we wanted to join the detection of DIF and its understanding. The reference group is the sample of United Kingdom and the focal group is the Spanish sample. The procedures of detection are Mantel-Haenszel, Logistic Regression and the standardized mean difference, and their extensions for polytomous items. Two items were flagged and the post-hoc analysis didn’t explain the causes of DIF entirely. Este trabajo analiza el funcionamiento diferencial del ítem (FDI de la prueba de comprensión lectora de la evaluación PISA2000 entre la muestras del Reino Unido y España. Se estudian los ítems liberados con el fin de aunar las fases de detección del FDI con la comprensión de sus causas. En la fase de detección se comparan los resultados de los procedimientos Mantel-Haenszel, Regresión Logística y Medias Estandarizadas en sus versiones para ítems dicotómicos y politómicos. Los resultados muestran que dos ítems presentan funcionamiento diferencial aunque el estudio post-hoc llevado a cabo sobre su contenido no ha podido precisar sus causas.

  2. Outcomes of restrictive versus liberal transfusion strategies in older adults from nine randomised controlled trials: a systematic review and meta-analysis.

    Science.gov (United States)

    Simon, Geoff I; Craswell, Alison; Thom, Ogilvie; Fung, Yoke Lin

    2017-10-01

    Guidelines for patient blood management recommend restrictive transfusion practice for most adult patients. These guidelines are supported by evidence from randomised controlled trials (RCTs); however, one of the patient groups not explicitly examined in these studies is the geriatric population. We examined RCTs relevant to transfusion outcomes in older patients. Our aim was to determine whether special guidelines are warranted for geriatric patients, recognising the different pathophysiological characteristics of this group. For this systematic review and meta-analysis, we searched PubMed, Scopus, and the Cochrane Library databases from their inception to May 5, 2017, for evidence relating to transfusion outcomes in adults aged 65 years and older. This criterion was widened to include RCTs where a substantial proportion of the study population was older than 65 years. We also included study populations of all clinical settings, and did not limit the search by date, language, or study type. For articles not in English, only available translations of the abstracts were reviewed. Studies were excluded if they did not specify age. Observational studies and duplicate patient and outcome data from studies that generated multiple publications were also excluded. We screened bibliographies of retrieved articles for additional publications. We analysed data extracted from published RCTs comparing restrictive and liberal transfusion strategies in older adults. We generated fixed effects risk ratios (RR) for pooled study data using the Mantel-Haenszel method. Primary outcomes were 30-day and 90-day mortality events for patients enrolled in restrictive and liberal transfusion study groups. We included intention-to-treat outcome data in the meta-analysis when available, otherwise we used per-protocol outcome data. 686 articles were identified by the search, and a further 37 by the snowball approach. Of these articles, 13 eligible papers described findings from nine RCTs (five

  3. Algebraic structures in generalized Clifford analysis and applications to boundary value problems

    Directory of Open Access Journals (Sweden)

    José Játem

    2015-12-01

    Full Text Available The present article has a threefold purpose: First it is a survey of the algebraic structures of generalized Clifford-type algebras and shows the main results of the corresponding Clifford-type analysis and its application to boundary value problems known so far. Second it is aimed to implement algorithms to provide the fast and accurate computation of boundary value problems for inhomogeneous equations in the framework of the generalized Clifford analysis. Finally it is also aimed to encourage the development of a generalized discrete Clifford analysis.

  4. Association between incision technique for hamstring tendon harvest in anterior cruciate ligament reconstruction and the risk of injury to the infra-patellar branch of the saphenous nerve: a meta-analysis.

    Science.gov (United States)

    Grassi, Alberto; Perdisa, Francesco; Samuelsson, Kristian; Svantesson, Eleonor; Romagnoli, Matteo; Raggi, Federico; Gaziano, Teide; Mosca, Massimiliano; Ayeni, Olufemi; Zaffagnini, Stefano

    2018-02-08

    To determine how the incision technique for hamstring tendon (HT) harvest in anterior cruciate ligament (ACL) reconstruction affects the risk of injury to the IPBSN and clinical outcome. A systematic literature search of the MEDLINE/Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL) and EBSCOhost electronic databases and clinicaltrials.gov for unpublished studies was performed to identify comparative studies investigating injury to the IPBSN after HT ACL reconstruction by comparing at least two different incision techniques. Data were extracted for the number of patients with evidence of any neurologic deficit corresponding to injury to the IPBSN, area of sensory deficit, the Lysholm score and patient satisfaction. The mean difference (MD) in study outcome between incision groups was assessed. The relative risk (RR) and the number needed to treat (NNT) were calculated. The Chi-square and Higgins' I 2 tests were applied to test heterogeneity. Data were pooled using a Mantel-Haenszel random-effects model if the statistical heterogeneity was > 50% and a fixed-effects model if the statistical heterogeneity was < 50%. The risk of bias was evaluated according to the Cochrane Database questionnaire and the quality of evidence was graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines. A total of eight studies (three randomized controlled trials (RCTs) and five comparative studies) were included, of which six compared vertical and oblique incisions, one horizontal and vertical incisions, and one compared all three techniques. HT harvest was performed through a vertical incision in 329 patients, through an oblique incision in 195 patients and through a horizontal incision in 151 patients. Considering the meta-analysis of the RCTs, the performance of a vertical incision significantly increased the risk of causing IPBSN deficiency compared with both oblique and horizontal incision [RR 1.65 (CI 1

  5. The general deterrence of driving while intoxicated. Volume 1, System analysis and computer-based simulation

    Science.gov (United States)

    1978-01-01

    A system analysis was completed of the general deterrence of driving while intoxicated (DWI). Elements which influence DWI decisions were identified and interrelated in a system model; then, potential countermeasures which might be employed in DWI ge...

  6. An analysis of referrals received by a psychiatric unit in a general ...

    African Journals Online (AJOL)

    An analysis of referrals received by a psychiatric unit in a general hospital part 1: the need for and research design adopted to study referrals received by a psychiatric unit in a general hospital: research. M. Dor, V.J. Ehlers, M.M. Van der Merwe ...

  7. Extension problem for generalized multi-monogenic functions in Clifford analysis

    International Nuclear Information System (INIS)

    Tran Quyet Thang.

    1992-10-01

    The main purpose of this paper is to extend some properties of multi-monogenic functions, which is a generalization of monogenic functions in higher dimensions, for a class of functions satisfying Vekua-type generalized Cauchy-Riemann equations in Clifford Analysis. It is proved that the Hartogs theorem is valid for these functions. (author). 7 refs

  8. Occurence of internet addiction in a general population sample: A latent class analysis

    NARCIS (Netherlands)

    Rumpf, H.J.; Vermulst, A.A.; Bischof, A.; Kastirke, N.; Gürtler, D.; Bischof, G.; Meerkerk, G.J.; John, U.; Meyer, C.

    2014-01-01

    Background: Prevalence studies of Internet addiction in the general population are rare. In addition, a lack of approved criteria hampers estimation of its occurrence. Aims: This study conducted a latent class analysis (LCA) in a large general population sample to estimate prevalence. Methods: A

  9. Entropy-based derivation of generalized distributions for hydrometeorological frequency analysis

    Science.gov (United States)

    Chen, Lu; Singh, Vijay P.

    2018-02-01

    Frequency analysis of hydrometeorological and hydrological extremes is needed for the design of hydraulic and civil infrastructure facilities as well as water resources management. A multitude of distributions have been employed for frequency analysis of these extremes. However, no single distribution has been accepted as a global standard. Employing the entropy theory, this study derived five generalized distributions for frequency analysis that used different kinds of information encoded as constraints. These distributions were the generalized gamma (GG), the generalized beta distribution of the second kind (GB2), and the Halphen type A distribution (Hal-A), Halphen type B distribution (Hal-B) and Halphen type inverse B distribution (Hal-IB), among which the GG and GB2 distribution were previously derived by Papalexiou and Koutsoyiannis (2012) and the Halphen family was first derived using entropy theory in this paper. The entropy theory allowed to estimate parameters of the distributions in terms of the constraints used for their derivation. The distributions were tested using extreme daily and hourly rainfall data. Results show that the root mean square error (RMSE) values were very small, which indicated that the five generalized distributions fitted the extreme rainfall data well. Among them, according to the Akaike information criterion (AIC) values, generally the GB2 and Halphen family gave a better fit. Therefore, those general distributions are one of the best choices for frequency analysis. The entropy-based derivation led to a new way for frequency analysis of hydrometeorological extremes.

  10. The Social Profile of Students in Basic General Education in Ecuador: A Data Analysis

    Science.gov (United States)

    Buri, Olga Elizabeth Minchala; Stefos, Efstathios

    2017-01-01

    The objective of this study is to examine the social profile of students who are enrolled in Basic General Education in Ecuador. Both a descriptive and multidimensional statistical analysis was carried out based on the data provided by the National Survey of Employment, Unemployment and Underemployment in 2015. The descriptive analysis shows the…

  11. Generalized linear models with random effects unified analysis via H-likelihood

    CERN Document Server

    Lee, Youngjo; Pawitan, Yudi

    2006-01-01

    Since their introduction in 1972, generalized linear models (GLMs) have proven useful in the generalization of classical normal models. Presenting methods for fitting GLMs with random effects to data, Generalized Linear Models with Random Effects: Unified Analysis via H-likelihood explores a wide range of applications, including combining information over trials (meta-analysis), analysis of frailty models for survival data, genetic epidemiology, and analysis of spatial and temporal models with correlated errors.Written by pioneering authorities in the field, this reference provides an introduction to various theories and examines likelihood inference and GLMs. The authors show how to extend the class of GLMs while retaining as much simplicity as possible. By maximizing and deriving other quantities from h-likelihood, they also demonstrate how to use a single algorithm for all members of the class, resulting in a faster algorithm as compared to existing alternatives. Complementing theory with examples, many of...

  12. A sensory analysis of butter cookies: An application of generalized procrustes analysis

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn

    1994-01-01

    Executive Summary: 1. A sensory analysis is one of the first steps in product development in the food industry. A thorough analysis of the results from such an analysis may give important input to the development process. 2. A sensory analysis on butter cookies is conducted in order to evaluate...

  13. The study about physical activity for subjects with prevention of benign prostate hyperplasia.

    Science.gov (United States)

    Lee, Ho Won; Kim, Shin Ah; Nam, Ji Won; Kim, Mi Kyung; Choi, Bo Youl; Moon, Hong Sang

    2014-09-01

    The number of benign prostatic hyperplasia (BPH) subjects has been increasing worldwide, and many studies have been conducted to determine the treatment that can delay drug therapy or surgery. Subsequently, most of these studies involved physical activity (PA) and associated factors. Therefore, we aimed to determine factors associated with BPH prevalence based on a review of past and present studies and to investigate the effect of a healthy lifestyle as a protective factor of BPH occurrence. We selected 582 subjects aged ≥40 years from an initial 779 subjects recruited from Gyeonggi, Yangpyeong, South Korea, during August 2009 to August 2011. Trained investigators surveyed International Prostate Symptom Score and demographic information, including PA and lifestyle questionnaire during face-to-face interviews; further, they performed digital rectal examination, rectal ultrasonography, and measured prostate-specific antigen levels. The statistical association between PA and BPH was analyzed by logistic regression analysis using multivariable regression models which use categorical variables by the Cochran-Mantel-Haenszel test and continuous variables by the general linear model. Seven statistically significant variables for PA were selected. Regular exercise, frequency of exercise, sedentary time, nonsedentary time, leisure time PA (metabolic equivalent, hr/wk) were not statistically associated with prostate volume but sedentary time (hr/day) was the only factor that showed a significant association in the multivariable model, including a linear effect relationship. Subjects with lower levels of sedentary time (4.5-7.0 hr/day) had a significantly lower risk of BPH (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.52-1.67) than those with a higher sedentary time (>7 hr/day) (OR, 1.72; 95% CI, 0.96-3.09) (P for trend=0.05). Our study showed that reducing sedentary time could have a protective effect and reduce the prevalence of BPH. Further prospective studies

  14. Non-monogamy: risk factor for STI transmission and acquisition and determinant of STI spread in populations.

    Science.gov (United States)

    Aral, Sevgi O; Leichliter, Jami S

    2010-12-01

    The concept of concurrent partnerships, while theoretically appealing, has been challenged at many levels. However, non-monogamy may be an important risk factor for the acquisition and transmission of sexually transmitted infections (STI). One's own non-monogamy is a risk factor for transmitting STI to others, partners' non-monogamy is a risk factor for acquiring STI and, most importantly, mutual non-monogamy is a population level determinant of increased STI spread. This study describes the levels, distribution and correlates of non-monogamy, partners' non-monogamy and mutual non-monogamy among adult men and women in the USA. Data from the National Survey of Family Growth (NSFG) Cycle 6 were used. NSFG is a national household survey of subjects aged 15-44 years in the USA. Cochran-Mantel-Haenszel tests and χ(2) tests were used in the analysis. Among sexually active adults, 17.6% of women and 23.0% of men (an estimated 19 million) reported non-monogamy over the past 12 months in 2002. An estimated 11 million Americans (1 in 10) reported partners' non-monogamy and an estimated 8.4 million (7% of women and 10.5% of men) reported mutual non-monogamy. All three types of non-monogamy were reported more frequently by men than women. Younger age, lower education, formerly or never married status, living below the poverty level and having spent time in jail were associated with all three types of non-monogamy in general. The three types of non-monogamy may be helpful in tailoring prevention messages and targeting prevention efforts to subgroups most likely to spread infection.

  15. PLHIV are more likely to have mental distress: evidence from a comparison of a cross-section of HIV and diabetes patients at Tertiary Hospitals in Nigeria.

    Science.gov (United States)

    Abiodun, Olumide; Lawal, Ismail; Omokanye, Christopher

    2018-02-19

    HIV is now regarded as a chronic disease because of the availability of treatment. However, it is not well known if there are differences (clinically and in magnitude) between the mental health status of PLHIV and people living with other chronic diseases. The aim of this study was to compare the mental health status of patients attending antiretroviral clinics to patients attending diabetes clinics at tertiary hospitals in Ogun State, Nigeria. A comparative hospital-based cross-sectional study of mental distress among 639 HIV-positive and 639 diabetic patients was carried out. Multivariate logistic regression analysis was used to control for confounders and to predict the probability of mental distress in PLHIV. The mean age of the participants was 44.87 (± 13.83) years and it had a range of 63 years (17 to 80). The prevalence of mental distress was higher among HIV-positive participants (46.79%) than diabetic participants (33.02%) (p < 0.0001). HIV-positive participants had greater odds of mental distress than diabetics (odds ratio = 1.78; 95% CI = 1.41-2.25). HIV-positivity, female sex, lower levels of education, being unemployed, poorer housing conditions and separated, widowed or divorced were associated with higher odds of mental distress (p < 0.05). Mental distress was predicted by HIV-positivity, occupation and current marital status. HIV infection and social inequalities are independent risk factors for mental distress. The odds of having mental distress is higher among PLHIV compared with diabetic patients. Addressing social inequalities might be the critical factor in the control of mental distress among PLHIV. ART: Anti-retroviral therapy; CI: Confidence interval; YLD: Years Lived with Disability; GHQ: General Health Questionnaire; HIV/AIDS: Human Immunodeficiency Virus/ Acquired Immunodeficiency Syndrome; LMIC: Low and middle-income countries; MH: Mantel-Haenszel; PLHIV: People living with HIV; ROC: Receiver operating characteristic.

  16. Biostatistics series module 4: Comparing groups - categorical variables

    Directory of Open Access Journals (Sweden)

    Avijit Hazra

    2016-01-01

    Full Text Available Categorical variables are commonly represented as counts or frequencies. For analysis, such data are conveniently arranged in contingency tables. Conventionally, such tables are designated as r × c tables, with r denoting number of rows and c denoting number of columns. The Chi-square (χ2 probability distribution is particularly useful in analyzing categorical variables. A number of tests yield test statistics that fit, at least approximately, a χ2 distribution and hence are referred to as χ2 tests. Examples include Pearson′s χ2 test (or simply the χ2 test, McNemar′s χ2 test, Mantel-Haenszel χ2 test and others. The Pearson′s χ2 test is the most commonly used test for assessing difference in distribution of a categorical variable between two or more independent groups. If the groups are ordered in some manner, the χ2 test for trend should be used. The Fisher′s exact probability test is a test of the independence between two dichotomous categorical variables. It provides a better alternative to the χ2 statistic to assess the difference between two independent proportions when numbers are small, but cannot be applied to a contingency table larger than a two-dimensional one. The McNemar′s χ2 test assesses the difference between paired proportions. It is used when the frequencies in a 2 × 2 table represent paired samples or observations. The Cochran′s Q test is a generalization of the McNemar′s test that compares more than two related proportions. The P value from the χ2 test or its counterparts does not indicate the strength of the difference or association between the categorical variables involved. This information can be obtained from the relative risk or the odds ratio statistic which is measures of dichotomous association obtained from 2 × 2 tables.

  17. Solution of damped generalized regularized long-wave equation using a modified homotopy analysis method

    Science.gov (United States)

    Akram, Ghazala; Sadaf, Maasoomah

    2018-02-01

    A modified algorithm for homotopy analysis method (MHAM) is presented for the solution of nonlinear damped generalized regularized long-wave equation. The modified algorithm has less computational cost than standard HAM and also overcomes the difficulty in calculating complicated integrals. The MHAM is applied on different cases of the damped generalized regularized long-wave equation subject to suitable initial conditions. The numerical results show that the approximate solutions are in good agreement with the exact solutions.

  18. Consistent linearization of the element-independent corotational formulation for the structural analysis of general shells

    Science.gov (United States)

    Rankin, C. C.

    1988-01-01

    A consistent linearization is provided for the element-dependent corotational formulation, providing the proper first and second variation of the strain energy. As a result, the warping problem that has plagued flat elements has been overcome, with beneficial effects carried over to linear solutions. True Newton quadratic convergence has been restored to the Structural Analysis of General Shells (STAGS) code for conservative loading using the full corotational implementation. Some implications for general finite element analysis are discussed, including what effect the automatic frame invariance provided by this work might have on the development of new, improved elements.

  19. Dental treatment under general anesthesia for special-needs patients: analysis of the literature.

    Science.gov (United States)

    Mallineni, Sreekanth K; Yiu, Cynthia K Y

    2016-11-01

    The aim of the present review was to identify the studies published on dental treatment under general anesthesia for special-needs patients. A comprehensive search of the reported literature from January 1966 to May 2012 was conducted using PubMed, Medline, and Embase. Keywords used in the search were "dental treatment under general anesthesia", "special-needs patients", "medically-compromised patients", and "children", in various combinations. Studies published only on dental treatment under general anesthesia and in English were included. Only 10 studies were available for final analysis. Age range from 1 to 50 years, and restorative procedures, were most prevalent. Only two studies discussed repeated general anesthesia, with rates of 7.2% and 10.2%. Over time, the provision of general anesthesia for special-needs patients has changed from dental clinics to general hospitals. The demand for dental treatment for special-needs patients under general anesthesia continues to increase. Currently, there are no certain accepted protocols for the provision of dental treatment under general anesthesia. © 2015 Wiley Publishing Asia Pty Ltd.

  20. Assessment of Random Assignment in Training and Test Sets using Generalized Cluster Analysis Technique

    Directory of Open Access Journals (Sweden)

    Sorana D. BOLBOACĂ

    2011-06-01

    Full Text Available Aim: The properness of random assignment of compounds in training and validation sets was assessed using the generalized cluster technique. Material and Method: A quantitative Structure-Activity Relationship model using Molecular Descriptors Family on Vertices was evaluated in terms of assignment of carboquinone derivatives in training and test sets during the leave-many-out analysis. Assignment of compounds was investigated using five variables: observed anticancer activity and four structure descriptors. Generalized cluster analysis with K-means algorithm was applied in order to investigate if the assignment of compounds was or not proper. The Euclidian distance and maximization of the initial distance using a cross-validation with a v-fold of 10 was applied. Results: All five variables included in analysis proved to have statistically significant contribution in identification of clusters. Three clusters were identified, each of them containing both carboquinone derivatives belonging to training as well as to test sets. The observed activity of carboquinone derivatives proved to be normal distributed on every. The presence of training and test sets in all clusters identified using generalized cluster analysis with K-means algorithm and the distribution of observed activity within clusters sustain a proper assignment of compounds in training and test set. Conclusion: Generalized cluster analysis using the K-means algorithm proved to be a valid method in assessment of random assignment of carboquinone derivatives in training and test sets.

  1. Computer-assisted semen analysis parameters as predictors for fertility of men from the general population

    DEFF Research Database (Denmark)

    Larsen, L; Scheike, Thomas Harder; Jensen, Tina Kold

    2000-01-01

    The predictive value of sperm motility parameters obtained by computer-assisted semen analysis (CASA) was evaluated for the fertility of men from general population. In a prospective study with couples stopping use of contraception in order to try to conceive, CASA was performed on semen samples...

  2. Regulating food law : risk analysis and the precautionary principle as general principles of EU food law

    NARCIS (Netherlands)

    Szajkowska, A.

    2012-01-01

    In food law scientific evidence occupies a central position. This study offers a legal insight into risk analysis and the precautionary principle, positioned in the EU as general principles applicable to all food safety measures, both national and EU. It develops a new method of looking at these

  3. An examination of generalized anxiety disorder and dysthymic disorder by latent class analysis

    NARCIS (Netherlands)

    Rhebergen, D.; van der Steenstraten, I.M.; Sunderland, M.; de Graaf, R.; ten Have, M.; Lamers, F.; Penninx, B.W.J.H.; Andrews, G.

    2014-01-01

    Background The nosological status of generalized anxiety disorder (GAD) versus dysthymic disorder (DD) has been questioned. The aim of this study was to examine qualitative differences within (co-morbid) GAD and DD symptomatology. Method Latent class analysis was applied to anxious and depressive

  4. Identifying At-Risk Students in General Chemistry via Cluster Analysis of Affective Characteristics

    Science.gov (United States)

    Chan, Julia Y. K.; Bauer, Christopher F.

    2014-01-01

    The purpose of this study is to identify academically at-risk students in first-semester general chemistry using affective characteristics via cluster analysis. Through the clustering of six preselected affective variables, three distinct affective groups were identified: low (at-risk), medium, and high. Students in the low affective group…

  5. A general procedure for estimating dynamic displacements using strain measurements and operational modal analysis

    DEFF Research Database (Denmark)

    Skafte, Anders; Aenlle, Manuel L.; Brincker, Rune

    2016-01-01

    Measurement systems are being installed in more and more civil structures with the purpose of monitoring the general dynamic behavior of the structure. The instrumentation is typically done with accelerometers, where experimental frequencies and mode shapes can be identified using modal analysis...

  6. Generalized canonical analysis based on optimizing matrix correlations and a relation with IDIOSCAL

    NARCIS (Netherlands)

    Kiers, Henk A.L.; Cléroux, R.; Ten Berge, Jos M.F.

    1994-01-01

    Carroll's method for generalized canonical analysis of two or more sets of variables is shown to optimize the sum of squared inner-product matrix correlations between a consensus matrix and matrices with canonical variates for each set of variables. In addition, the method that analogously optimizes

  7. Generalized canonical correlation analysis of matrices with missing rows : A simulation study

    NARCIS (Netherlands)

    van de Velden, Michel; Bijmolt, Tammo H. A.

    A method is presented for generalized canonical correlation analysis of two or more matrices with missing rows. The method is a combination of Carroll's (1968) method and the missing data approach of the OVERALS technique (Van der Burg, 1988). In a simulation study we assess the performance of the

  8. 77 FR 47621 - Appalachian Gateway Project; Notice of Availability of Draft General Conformity Analysis

    Science.gov (United States)

    2012-08-09

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP10-448-000] Appalachian Gateway Project; Notice of Availability of Draft General Conformity Analysis In accordance with the... (GCD) for the Appalachian Gateway Project (Project) to assess the potential air quality impacts...

  9. A general purpose program system for high energy physics experiment data acquisition and analysis

    International Nuclear Information System (INIS)

    Li Shuren; Xing Yuguo; Jin Bingnian

    1985-01-01

    This paper introduced the functions, structure and system generation of a general purpose program system (Fermilab MULTI) for high energy physics experiment data acquisition and analysis. Works concerning the reconstruction of MULTI system level 0.5 which can be run on the computer PDP-11/23 are also introduced briefly

  10. Classification of shoulder complaints in general practice by means of cluster analysis

    NARCIS (Netherlands)

    Winters, JC; Groenier, KH; Sobel, JS; Arendzen, HH; Meyboom-de Jong, B

    1997-01-01

    Objective: To determine if a classification of shoulder complaints in general practice can be made with a cluster analysis of variables of medical history and physical examination. Method: One hundred one patients with shoulder complaints were examined upon inclusion (week 0) and after 2 weeks.

  11. [Spinal anesthesia versus general anesthesia in the surgical treatment of inguinal hernia. Cost-effectiveness analysis].

    Science.gov (United States)

    Fernández-Ordóñez, M; Tenías, J M; Picazo-Yeste, J

    2014-05-01

    To compare the costs related to the clinical effectiveness of general anesthesia versus spinal anesthesia in inguinal hernioplasty ambulatory surgery. An observational, retrospective cohort study measurement and analysis of cost-effectiveness, in the ambulatory surgery unit of a general hospital. All patients over 18 years of age diagnosed with primary inguinal hernia and scheduled for unilateral hernioplasty between January 2010 and December 2011 were included. Duration of anesthetic induction, length of stay in both the operating room, and in the post-anesthesia care unit, the anesthetic effectiveness (the incidence of adverse effects and the patient's comfort level), and variable economic costs associated with the use of drugs, as well as the use of human resources, were compared. The final analysis included 218 patients, 87.2% male, with a mean age of 53 years (range: 18-85 years). Of these, 139 (63.76%) received subarachnoid anesthesia and 79,(36.2%) general anesthesia. The length of time a patient remained in the post-anesthesia care unit was 337.6±160.2min in the subarachnoid anesthesia group, and 210.0±97.5min for the general anesthesia group (P<.001). Costs of drugs for general anesthesia were higher than that for subarachnoid anesthesia (86.2±8.3 vs. 18.7±7.2). The total cost difference between the 2 techniques was €115.8 more for subarachnoid anesthesia (P<.001). Both techniques showed similar effectiveness. The overall costs for subarachnoid anesthesia were greater than for the general. The cost-effectiveness of general anesthesia is better for outpatient inguinal hernia repair surgery. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

  12. A General Model for Thermal, Hydraulic and Electric Analysis of Superconducting Cables

    CERN Document Server

    Bottura, L; Rosso, C

    2000-01-01

    In this paper we describe a generic, multi-component and multi-channel model for the analysis of superconducting cables. The aim of the model is to treat in a general and consistent manner simultaneous thermal, electric and hydraulic transients in cables. The model is devised for most general situations, but reduces in limiting cases to most common approximations without loss of efficiency. We discuss here the governing equations, and we write them in a matrix form that is well adapted to numerical treatment. We finally demonstrate the model capability by comparison with published experimental data on current distribution in a two-strand cable.

  13. A unified MGF-based capacity analysis of diversity combiners over generalized fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2012-03-01

    Unified exact ergodic capacity results for L-branch coherent diversity combiners including equal-gain combining (EGC) and maximal-ratio combining (MRC) are not known. This paper develops a novel generic framework for the capacity analysis of L-branch EGC/MRC over generalized fading channels. The framework is used to derive new results for the gamma-shadowed generalized Nakagami-m fading model which can be a suitable model for the fading environments encountered by high frequency (60 GHz and above) communications. The mathematical formalism is illustrated with some selected numerical and simulation results confirming the correctness of our newly proposed framework. © 2012 IEEE.

  14. The general critical analysis for continuous-time UPPAM recurrent neural networks.

    Science.gov (United States)

    Qiao, Chen; Jing, Wen-Feng; Fang, Jian; Wang, Yu-Ping

    2016-01-29

    The uniformly pseudo-projection-anti-monotone (UPPAM) neural network model, which can be considered as the unified continuous-time neural networks (CNNs), includes almost all of the known CNNs individuals. Recently, studies on the critical dynamics behaviors of CNNs have drawn special attentions due to its importance in both theory and applications. In this paper, we will present the analysis of the UPPAM network under the general critical conditions. It is shown that the UPPAM network possesses the global convergence and asymptotical stability under the general critical conditions if the network satisfies one quasi-symmetric requirement on the connective matrices, which is easy to be verified and applied. The general critical dynamics have rarely been studied before, and this work is an attempt to gain an meaningful assurance of general critical convergence and stability of CNNs. Since UPPAM network is the unified model for CNNs, the results obtained here can generalize and extend the existing critical conclusions for CNNs individuals, let alone those non-critical cases. Moreover, the easily verified conditions for general critical convergence and stability can further promote the applications of CNNs.

  15. Use of generalized linear mixed models for network meta-analysis.

    Science.gov (United States)

    Tu, Yu-Kang

    2014-10-01

    In the past decade, a new statistical method-network meta-analysis-has been developed to address limitations in traditional pairwise meta-analysis. Network meta-analysis incorporates all available evidence into a general statistical framework for comparisons of multiple treatments. Bayesian network meta-analysis, as proposed by Lu and Ades, also known as "mixed treatments comparisons," provides a flexible modeling framework to take into account complexity in the data structure. This article shows how to implement the Lu and Ades model in the frequentist generalized linear mixed model. Two examples are provided to demonstrate how centering the covariates for random effects estimation within each trial can yield correct estimation of random effects. Moreover, under the correct specification for random effects estimation, the dummy coding and contrast basic parameter coding schemes will yield the same results. It is straightforward to incorporate covariates, such as moderators and confounders, into the generalized linear mixed model to conduct meta-regression for multiple treatment comparisons. Moreover, this approach may be extended easily to other types of outcome variables, such as continuous, counts, and multinomial. © The Author(s) 2014.

  16. Idade materna como fator de risco: estudo com primigestas na faixa etária igual ou superior a 28 anos La edad materna como un factor de riesgo: estudio com primigestas en la facha etaria igual o superior a 28 años Maternal age as a risk factor: a study on first time pregnant women with age equal or higher than 28 years old

    Directory of Open Access Journals (Sweden)

    Cristina Maria Garcia de Lima Parada

    1999-10-01

    después de controlado el tipo de parto, para las siguientes complicaciones perinatales: taquipnea transitoria del recien nacido, cianosis generalizada ao nacer e infección neonatal.This is a transverse-type designed study with the aim analise maternal age as a risk factor, and as not a risk factor, through the verification of incidents during pregnancy, birth and puerperium of first time pregnant women with age equal or higher than 28 years old; as well as birth conditions and discharge of their newborns, comparing them with a group of first time pregnant women from 20 to 27 years old. The study was carried out in Botucatu, São Paulo, from January, 1990 to June, 1995. The statistical analysis, discussed at the level of 5% of significance, was developed through Mann-Whitney test, Goodman test and the evaluation of relative risk and corrected relative risk through Mantel-Haenszel technique. We concluded that maternal age equal or higher than 28 years old, is not a pregnancy, puerperal and intrapartum risk factor, although, on the other hand, it was a risk factor even after controlled parturition for the following perinatal incidents: newborn tachypnea, generalized cyanosis at birth and neonatal infection.

  17. Meta-analysis of operative experiences of general surgery trainees during training.

    Science.gov (United States)

    Elsey, E J; Griffiths, G; Humes, D J; West, J

    2017-01-01

    General surgical training curricula around the world set defined operative numbers to be achieved before completion of training. However, there are few studies reporting total operative experience in training. This systematic review aimed to quantify the published global operative experience at completion of training in general surgery. Electronic databases were searched systematically for articles in any language relating to operative experience in trainees completing postgraduate general surgical training. Two reviewers independently assessed citations for inclusion using agreed criteria. Studies were assessed for quantitative data in addition to study design and purpose. A meta-analysis was performed using a random-effects model of studies with appropriate data. The search resulted in 1979 titles for review. Of these, 24 studies were eligible for inclusion in the review and data from five studies were used in the meta-analysis. Studies with published data of operative experience at completion of surgical training originated from the USA (19), UK (2), the Netherlands (1), Spain (1) and Thailand (1). Mean total operative experience in training varied from 783 procedures in Thailand to 1915 in the UK. Meta-analysis produced a mean pooled estimate of 1366 (95 per cent c.i. 1026 to 1707) procedures per trainee at completion of training. There was marked heterogeneity between studies (I 2  = 99·6 per cent). There is a lack of robust data describing the operative experiences of general surgical trainees outside the USA. The number of surgical procedures performed by general surgeons in training varies considerably across the world. © 2016 The Authors. BJS published by John Wiley & Sons Ltd on behalf of BJS Society Ltd.

  18. Associations of general parenting and parent-child relationship with pediatric obesity: a meta-analysis.

    Science.gov (United States)

    Pinquart, Martin

    2014-05-01

    The objective of the meta-analysis is to integrate available results on associations of general parenting (not specific to feeding and activity promotion) and parent-child relations with child weight status, eating, and physical activity. Searching in electronic databases and cross-referencing identified 156 empirical studies. Random-effects meta-analysis was computed. A positive parent-child relationship and higher levels of parental responsiveness were associated with lower weight, healthier eating, and more physical activity of the child. Parental demandingness, overprotection, psychological control, inconsistency, and parenting styles showed associations with some of the assessed outcome variables. Most effect sizes were small and varied by study characteristics. The small effects do not support making general parenting styles, parental demandingness, responsiveness, and the quality of the parent-child relationship a main target of preventing and treating obesity. Reducing parental inconsistency may be a better target if available results are replicated in future studies.

  19. Aberration analysis for freeform surface terms overlay on general decentered and tilted optical surfaces.

    Science.gov (United States)

    Yang, Tong; Cheng, Dewen; Wang, Yongtian

    2018-03-19

    Aberration theory helps designers to better understand the nature of imaging systems. However, the existing aberration theory of freeform surfaces has many limitations. For example, it only works in the special case when the central area of the freeform surface is used. In addition, the light footprint is limited to a circle, which does not match the case of an elliptical footprint for general systems. In this paper, aberrations generated by freeform surface term overlay on general decentered and tilted optical surfaces are analyzed. For the case when the off-axis section of a freeform surface is used, the aberration equation for using stop and nonstop surfaces is discussed, and the aberrations generated by Zernike terms up to Z 17/18 are analyzed in detail. To solve the problem of the elliptical light footprint for tilted freeform surfaces, the scaled pupil vector is used in the aberration analysis. The mechanism of aberration transformation is discovered, and the aberrations generated by different Zernike terms in this case are calculated. Finally we proposed aberration equations for freeform terms on general decentered and tilted freeform surfaces. The research result given in this paper offers an important reference for optical designers and engineers, and it is of great importance in developing analytical methods for general freeform system design, tolerance analysis, and system assembly.

  20. Bias formulas for sensitivity analysis of unmeasured confounding for general outcomes, treatments, and confounders.

    Science.gov (United States)

    Vanderweele, Tyler J; Arah, Onyebuchi A

    2011-01-01

    Uncontrolled confounding in observational studies gives rise to biased effect estimates. Sensitivity analysis techniques can be useful in assessing the magnitude of these biases. In this paper, we use the potential outcomes framework to derive a general class of sensitivity-analysis formulas for outcomes, treatments, and measured and unmeasured confounding variables that may be categorical or continuous. We give results for additive, risk-ratio and odds-ratio scales. We show that these results encompass a number of more specific sensitivity-analysis methods in the statistics and epidemiology literature. The applicability, usefulness, and limits of the bias-adjustment formulas are discussed. We illustrate the sensitivity-analysis techniques that follow from our results by applying them to 3 different studies. The bias formulas are particularly simple and easy to use in settings in which the unmeasured confounding variable is binary with constant effect on the outcome across treatment levels.

  1. An Entropy-Based Approach to Path Analysis of Structural Generalized Linear Models: A Basic Idea

    Directory of Open Access Journals (Sweden)

    Nobuoki Eshima

    2015-07-01

    Full Text Available A path analysis method for causal systems based on generalized linear models is proposed by using entropy. A practical example is introduced, and a brief explanation of the entropy coefficient of determination is given. Direct and indirect effects of explanatory variables are discussed as log odds ratios, i.e., relative information, and a method for summarizing the effects is proposed. The example dataset is re-analyzed by using the method.

  2. Generalized Population Analysis of Three-Center Two-Electron Bonding

    Czech Academy of Sciences Publication Activity Database

    Ponec, Robert; Cooper, D. L.

    2004-01-01

    Roč. 97, č. 6 (2004), s. 1002-1011 ISSN 0020-7608 R&D Projects: GA AV ČR IAA4072006; GA MŠk OC D9.20 Institutional research plan: CEZ:AV0Z4072921 Keywords : multicenter bonding * generalized population analysis * post- Hartree Fock wave functions Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.392, year: 2004

  3. Use of generalized ordered logistic regression for the analysis of multidrug resistance data.

    Science.gov (United States)

    Agga, Getahun E; Scott, H Morgan

    2015-10-01

    Statistical analysis of antimicrobial resistance data largely focuses on individual antimicrobial's binary outcome (susceptible or resistant). However, bacteria are becoming increasingly multidrug resistant (MDR). Statistical analysis of MDR data is mostly descriptive often with tabular or graphical presentations. Here we report the applicability of generalized ordinal logistic regression model for the analysis of MDR data. A total of 1,152 Escherichia coli, isolated from the feces of weaned pigs experimentally supplemented with chlortetracycline (CTC) and copper, were tested for susceptibilities against 15 antimicrobials and were binary classified into resistant or susceptible. The 15 antimicrobial agents tested were grouped into eight different antimicrobial classes. We defined MDR as the number of antimicrobial classes to which E. coli isolates were resistant ranging from 0 to 8. Proportionality of the odds assumption of the ordinal logistic regression model was violated only for the effect of treatment period (pre-treatment, during-treatment and post-treatment); but not for the effect of CTC or copper supplementation. Subsequently, a partially constrained generalized ordinal logistic model was built that allows for the effect of treatment period to vary while constraining the effects of treatment (CTC and copper supplementation) to be constant across the levels of MDR classes. Copper (Proportional Odds Ratio [Prop OR]=1.03; 95% CI=0.73-1.47) and CTC (Prop OR=1.1; 95% CI=0.78-1.56) supplementation were not significantly associated with the level of MDR adjusted for the effect of treatment period. MDR generally declined over the trial period. In conclusion, generalized ordered logistic regression can be used for the analysis of ordinal data such as MDR data when the proportionality assumptions for ordered logistic regression are violated. Published by Elsevier B.V.

  4. Assimilation of tourism satellite accounts and applied general equilibrium models to inform tourism policy analysis

    OpenAIRE

    Rossouw, Riaan; Saayman, Melville

    2011-01-01

    Historically, tourism policy analysis in South Africa has posed challenges to accurate measurement. The primary reason for this is that tourism is not designated as an 'industry' in standard economic accounts. This paper therefore demonstrates the relevance and need for applied general equilibrium (AGE) models to be completed and extended through an integration with tourism satellite accounts (TSAs) as a tool for policy makers (especially tourism policy makers) in South Africa. The paper sets...

  5. A bibliometric analysis of Australian general practice publications from 1980 to 2007 using PubMed

    Directory of Open Access Journals (Sweden)

    Kumara Mendis

    2010-12-01

    Discussion Australian GP publications have shown an impressive growth from 1980 to 2007 with a 15- fold increase. This increase may be due in part to the actions of the Australian government over the past decade to financially support research in primary care, as well as the maturing of academic general practice. This analysis can assist governments, researchers, policy makers and others to target resources so that further developments can be encouraged, supported and monitored.

  6. Implications of the Biofuels Boom for the Global Livestock Industry: A Computable General Equilibrium Analysis

    OpenAIRE

    Taheripour, Farzad; Hertel, Thomas W.; Tyner, Wallace E.

    2009-01-01

    In this paper, we offer a general equilibrium analysis of the impacts of US and EU biofuel mandates for the global livestock sector. Our simulation boosts biofuel production in the US and EU from 2006 levels to mandated 2015 levels. We show that mandates will encourage crop production in both biofuel and non biofuel producing regions, while reducing livestock and livestock production in most regions of the world. The non-ruminant industry curtails its production more than other livestock indu...

  7. Social phobia subtypes in the general population revealed by cluster analysis.

    Science.gov (United States)

    Furmark, T; Tillfors, M; Stattin, H; Ekselius, L; Fredrikson, M

    2000-11-01

    Epidemiological data on subtypes of social phobia are scarce and their defining features are debated. Hence, the present study explored the prevalence and descriptive characteristics of empirically derived social phobia subgroups in the general population. To reveal subtypes, data on social distress, functional impairment, number of social fears and criteria fulfilled for avoidant personality disorder were extracted from a previously published epidemiological study of 188 social phobics and entered into an hierarchical cluster analysis. Criterion validity was evaluated by comparing clusters on the Social Phobia Scale (SPS) and the Social Interaction Anxiety Scale (SIAS). Finally, profile analyses were performed in which clusters were compared on a set of sociodemographic and descriptive characteristics. Three clusters emerged, consisting of phobics scoring either high (generalized subtype), intermediate (non-generalized subtype) or low (discrete subtype) on all variables. Point prevalence rates were 2.0%, 5.9% and 7.7% respectively. All subtypes were distinguished on both SPS and SIAS. Generalized or severe social phobia tended to be over-represented among individuals with low levels of educational attainment and social support. Overall, public-speaking was the most common fear. Although categorical distinctions may be used, the present data suggest that social phobia subtypes in the general population mainly differ dimensionally along a mild moderate-severe continuum, and that the number of cases declines with increasing severity.

  8. The Use of Office-Based Sedation and General Anesthesia by Board Certified Pediatric Dentists Practicing in the United States

    Science.gov (United States)

    Olabi, Nassim F.; Jones, James E.; Saxen, Mark A.; Sanders, Brian J.; Walker, LaQuia A.; Weddell, James A.; Schrader, Stuart M.; Tomlin, Angela M.

    2012-01-01

    The purpose of this study is to explore the use of office-based sedation by board-certified pediatric dentists practicing in the United States. Pediatric dentists have traditionally relied upon self-administered sedation techniques to provide office-based sedation. The use of dentist anesthesiologists to provide office-based sedation is an emerging trend. This study examines and compares these two models of office-based sedations. A survey evaluating office-based sedation of diplomates of the American Board of Pediatric Dentistry (ABPD) based on gender, age, years in practice, practice types, regions, and years as a diplomate of the ABPD was completed by 494 active members. The results were summarized using frequencies and percentages. Relationships of dentist age, gender, and number of years in practice with the use of intravenous (IV) sedation was completed using two-way contingency tables and Mantel-Haenszel tests for ordered categorical data. Relationships of office-based sedation use and the type of one's practice were examined using Pearson chi-square tests. Of the 1917 surveys e-mailed, 494 completed the survey for a response rate of 26%. Over 70% of board-certified US pediatric dentists use some form of sedation in their offices. Less than 20% administer IV sedation, 20 to 40% use a dentist anesthesiologist, and 60 to 70% would use dentist anesthesiologists if one were available. PMID:22428969

  9. Stability analysis on the free surface phenomena of a magnetic fluid for general use

    International Nuclear Information System (INIS)

    Mizuta, Yo

    2011-01-01

    This paper presents an analysis for elucidating a variety of physical processes on the interface (free surface) of magnetic fluid. The present analysis is composed of the magnetic and the fluid analysis, both of which have no limitations concerning the interface elevation or its profile. The magnetic analysis provides rigorous interface magnetic field under arbitrary distributions of applied magnetic field. For the fluid analysis, the equation for interface motion includes all nonlinear effects. Physical quantities such as the interface magnetic field or the interface stresses, obtained first as the wavenumber components, facilitate confirming the relations with those by the conventional theoretical analyses. The nonlinear effect is formulated as the nonlinear mode coupling between the interface profile and the applied magnetic field. The stability of the horizontal interface profile is investigated by the dispersion relation, and summarized as the branch line. Furthermore, the balance among the spectral components of the interface stresses are shown, within the sufficient range of the wavenumber space. - Research Highlights: → General, rigorous but compact analysis for free surface phenomena is shown. → Analysis is applied without limitations on the interface elevation or its profile. → Nonlinear effects are formulated as the nonlinear mode coupling. → Bifurcation of stability is summarized as the branch line. → Balance among the interface stresses are shown in the wavenumber space.

  10. Cuestionario general de salud-12: análisis de factores en población general de Bucaramanga, Colombia General health questionnaire-12: factor analysis in the general population of Bucaramanga, Colombia

    Directory of Open Access Journals (Sweden)

    Adalberto Campo Arias

    2007-03-01

    Full Text Available ANTECEDENTES: el cuestionario general de salud de doce puntos (GHQ-12 es un instrumento diseñado para cuantificar síntomas emocionales (trastornos mentales comunes en diferentes contextos. Sin embargo, no se conoce la estructura factorial de esta versión en población colombiana. OBJETIVO: conocer la estructura de factores y la mejor forma de puntuación para el GHQ-12 en población general de Bucaramanga, Colombia. MÉTODO: una muestra probabilística de la población general, representada por 2.496 adultos entre 18 y 65 años, diligenció el GHQ-12. Se determinó la consistencia interna y los factores para las formas de puntuación ordinal (0-1-2-3 y binarias (0-0-0-1, 0-0-1-1 y 0-1-1-1. RESULTADOS: la forma ordinal mostró una consistencia interna de 0,779 y dos factores que explicaban 42,5% de la varianza. Por otro lado, la forma binaria 0-1-1-1 presentó una consistencia interna de 0,774; la forma 0-0-1-1, de 0,708; y la forma 0-0-0-1, de 0,360. Las formas binarias 0-1-1-1 y 0-0-1-1 mostraron tres factores responsables de 50,6% y 46,3%, respectivamente. La forma 0-0-0-1 no presentó una aceptable solución factorial. CONCLUSIONES: en Bucaramanga, la forma de puntuación ordinal presenta un mejor comportamiento psicométrico que las binarias. Todas las formas de puntuación muestran alta consistencia interna y aceptable solución factorial, excepto la forma 0-0-0-1 BACKGROUND: The General Health Questionnaire (GHQ-12 was designed to quantify emotional symptoms (common mental disorders in different settings. However, its factor structure is not known in Colombian population. OBJECTIVE: To establish the factor structure and the best form of punctuation for the GHQ-12 in the general population of Bucaramanga, Colombia. METHOD: A probabilistic sample of 2,496 adults from the general population in Bucaramanga, Colombia, completed the GHQ-12. The internal consistency and analysis factor were computed for the ordinal scoring (0-1-2-3 and for

  11. General practice-based clinical trials in Germany - a problem analysis

    Directory of Open Access Journals (Sweden)

    Hummers-Pradier Eva

    2012-11-01

    Full Text Available Abstract Background In Germany, clinical trials and comparative effectiveness studies in primary care are still very rare, while their usefulness has been recognised in many other countries. A network of researchers from German academic general practice has explored the reasons for this discrepancy. Methods Based on a comprehensive literature review and expert group discussions, problem analyses as well as structural and procedural prerequisites for a better implementation of clinical trials in German primary care are presented. Results In Germany, basic biomedical science and technology is more reputed than clinical or health services research. Clinical trials are funded by industry or a single national programme, which is highly competitive, specialist-dominated, exclusive of pilot studies, and usually favours innovation rather than comparative effectiveness studies. Academic general practice is still not fully implemented, and existing departments are small. Most general practitioners (GPs work in a market-based, competitive setting of small private practices, with a high case load. They have no protected time or funding for research, and mostly no research training or experience. Good Clinical Practice (GCP training is compulsory for participation in clinical trials. The group defined three work packages to be addressed regarding clinical trials in German general practice: (1 problem analysis, and definition of (2 structural prerequisites and (3 procedural prerequisites. Structural prerequisites comprise specific support facilities for general practice-based research networks that could provide practices with a point of contact. Procedural prerequisites consist, for example, of a summary of specific relevant key measures, for example on a web platform. The platform should contain standard operating procedures (SOPs, templates, checklists and other supporting materials for researchers. Conclusion All in all, our problem analyses revealed that

  12. A General Contact Force Analysis of an Under-Actuated Finger in Robot Hand Grasping

    Directory of Open Access Journals (Sweden)

    Xuan Vinh Ha

    2016-02-01

    Full Text Available This paper develops a mathematical analysis of contact forces for the under-actuated finger in a general under-actuated robotic hand during grasping. The concept of under-actuation in robotic grasping with fewer actuators than degrees of freedom (DOF, through the use of springs and mechanical limits, allows the hand to adjust itself to an irregularly shaped object without complex control strategies and sensors. Here the main concern is the contact forces, which are important elements in grasping tasks, based on the proposed mathematical analysis of their distributions of the n-DOF under-actuated finger. The simulation results, along with the 3-DOF finger from the ADAMS model, show the effectiveness of the mathematical analysis method, while comparing them with the measured results. The system can find magnitudes of the contact forces at the contact positions between the phalanges and the object.

  13. Application of discriminant analysis and generalized distance measures to uranium exploration

    International Nuclear Information System (INIS)

    Beauchamp, J.J.; Begovich, C.L.; Kane, V.E.; Wolf, D.A.

    1980-01-01

    The National Uranium Resource Evaluation (NURE) Program has as its goal the estimation of the nation's uranium resources. It is possile to use discriminant analysis methods on hydrogeochemical data collected in the NURE Program to aid in fomulating geochemical models that can be used to identify the anomalous areas used in resource estimation. Discriminant' analysis methods have been applied to data from the Plainview, Texas Quadrangle which has approximately 850 groundwater samples with more than 40 quantitative measurements per sample. Discriminant analysis topics involving estimation of misclassification probabilities, variable selection, and robust discrimination are applied. A method using generalized distance measures is given which enables the assignment of samples to a background population or a mineralized population whose parameters were estimated from separate studies. Each topic is related to its relevance in identifying areas of possible interest to uranium exploration. However, the methodology presented here is applicable to the identification of regions associated with other types of resources. 8 figures, 3 tables

  14. The ICVSIE: A General Purpose Integral Equation Method for Bio-Electromagnetic Analysis.

    Science.gov (United States)

    Gomez, Luis J; Yucel, Abdulkadir C; Michielssen, Eric

    2018-03-01

    An internally combined volume surface integral equation (ICVSIE) for analyzing electromagnetic (EM) interactions with biological tissue and wide ranging diagnostic, therapeutic, and research applications, is proposed. The ICVSIE is a system of integral equations in terms of volume and surface equivalent currents in biological tissue subject to fields produced by externally or internally positioned devices. The system is created by using equivalence principles and solved numerically; the resulting current values are used to evaluate scattered and total electric fields, specific absorption rates, and related quantities. The validity, applicability, and efficiency of the ICVSIE are demonstrated by EM analysis of transcranial magnetic stimulation, magnetic resonance imaging, and neuromuscular electrical stimulation. Unlike previous integral equations, the ICVSIE is stable regardless of the electric permittivities of the tissue or frequency of operation, providing an application-agnostic computational framework for EM-biomedical analysis. Use of the general purpose and robust ICVSIE permits streamlining the development, deployment, and safety analysis of EM-biomedical technologies.

  15. A meta-analysis of core stability exercise versus general exercise for chronic low back pain.

    Science.gov (United States)

    Wang, Xue-Qiang; Zheng, Jie-Jiao; Yu, Zhuo-Wei; Bi, Xia; Lou, Shu-Jie; Liu, Jing; Cai, Bin; Hua, Ying-Hui; Wu, Mark; Wei, Mao-Ling; Shen, Hai-Min; Chen, Yi; Pan, Yu-Jian; Xu, Guo-Hui; Chen, Pei-Jie

    2012-01-01

    To review the effects of core stability exercise or general exercise for patients with chronic low back pain (LBP). Exercise therapy appears to be effective at decreasing pain and improving function for patients with chronic LBP in practice guidelines. Core stability exercise is becoming increasingly popular for LBP. However, it is currently unknown whether core stability exercise produces more beneficial effects than general exercise in patients with chronic LBP. Published articles from 1970 to October 2011 were identified using electronic searches. For this meta-analysis, two reviewers independently selected relevant randomized controlled trials (RCTs) investigating core stability exercise versus general exercise for the treatment of patients with chronic LBP. Data were extracted independently by the same two individuals who selected the studies. From the 28 potentially relevant trials, a total of 5 trials involving 414 participants were included in the current analysis. The pooling revealed that core stability exercise was better than general exercise for reducing pain [mean difference (-1.29); 95% confidence interval (-2.47, -0.11); P = 0.003] and disability [mean difference (-7.14); 95% confidence interval (-11.64, -2.65); P = 0.002] at the time of the short-term follow-up. However, no significant differences were observed between core stability exercise and general exercise in reducing pain at 6 months [mean difference (-0.50); 95% confidence interval (-1.36, 0.36); P = 0.26] and 12 months [mean difference (-0.32); 95% confidence interval (-0.87, 0.23); P = 0.25]. Compared to general exercise, core stability exercise is more effective in decreasing pain and may improve physical function in patients with chronic LBP in the short term. However, no significant long-term differences in pain severity were observed between patients who engaged in core stability exercise versus those who engaged in general exercise. http

  16. Fasting insulin, insulin resistance and risk of hypertension in the general population: A meta-analysis.

    Science.gov (United States)

    Wang, Feng; Han, Lili; Hu, Dayi

    2017-01-01

    Studies on the association of fasting insulin concentrations or insulin resistance with subsequent risk of hypertension have yielded conflicting results. To quantitatively assess the association of fasting insulin concentrations or homeostasis model assessment insulin resistance (HOMA-IR) with incident hypertension in a general population by performing a meta-analysis. We searched the PubMed and Embase databases until August 31, 2016 for prospective observational studies investigating the elevated fasting insulin concentrations or HOMA-IR with subsequent risk of hypertension in the general population. Pooled risk ratio (RR) and 95% confidence interval (CI) of hypertension was calculated for the highest versus the lowest category of fasting insulin or HOMA-IR. Eleven studies involving 10,230 hypertension cases were identified from 55,059 participants. Meta-analysis showed that the pooled adjusted RR of hypertension was 1.54 (95% CI 1.34-1.76) for fasting insulin concentrations and 1.43 (95% CI 1.27-1.62) for HOMA-IR comparing the highest to the lowest category. Subgroup analysis results showed that the association of fasting insulin concentrations with subsequent risk of hypertension seemed more pronounced in women (RR 2.07; 95% CI 1.19-3.60) than in men (RR 1.48; 95% CI 1.17-1.88). This meta-analysis suggests that elevated fasting insulin concentrations or insulin resistance as estimated by homeostasis model assessment is independently associated with an exacerbated risk of hypertension in the general population. Early intervention of hyperinsulinemia or insulin resistance may help clinicians to identify the high risk of hypertensive population. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Linear stability analysis of parallel shear flows for an inviscid generalized two-dimensional fluid system

    International Nuclear Information System (INIS)

    Iwayama, T; Sueyoshi, M; Watanabe, T

    2013-01-01

    The linear stability of parallel shear flows for an inviscid generalized two-dimensional (2D) fluid system, the so-called α turbulence system, is studied. This system is characterized by the relation q = −( − Δ) α/2 ψ between the advected scalar q and the stream function ψ. Here, α is a real number not exceeding 3 and q is referred to as the generalized vorticity. In this study, a sufficient condition for linear stability of parallel shear flows is derived using the conservation of wave activity. A stability analysis is then performed for a sheet vortex that violates the stability condition. The instability of a sheet vortex in the 2D Euler system (α = 2) is referred to as a Kelvin–Helmholtz (KH) instability; such an instability for the generalized 2D fluid system is investigated for 0 3−α for 1 < α < 3, where k is the wavenumber of the perturbation. In contrast, for 0 < α ⩽ 1, the growth rate is infinite. In other words, a transition of the growth rate of the perturbation occurs at α = 1. A physical model for KH instability in the generalized 2D fluid system, which can explain the transition of the growth rate of the perturbation at α = 1, is proposed. (paper)

  18. Selection for delayed intravenous alteplase treatment based on a prognostic score.

    Science.gov (United States)

    Fulton, Rachael L; Lees, Kennedy R; Bluhmki, Erich; Biegert, Gabriele; Albers, Gregory W; Davis, Stephen M; Donnan, Geoffrey A; Grotta, James C; Hacke, Werner; Kaste, Markku; von Kummer, Rüdiger; Shuaib, Ashfaq; Toni, Danilo

    2015-01-01

    Approved use of intravenous alteplase for ischemic stroke offers net benefit. Pooled randomized controlled trial analysis suggests additional patients could benefit but others be harmed with treatment initiated beyond 4·5 h after stroke onset. We proposed prognostic scoring methods to identify a strategy for patient selection. We selected 500 patients treated by intravenous alteplase and 500 controls from Virtual International Stroke Trials Archive, matching modified Rankin score outcomes to those from pooled randomized controlled trial 4·5-6 h data. We ranked patients by prognostic score. We chose limits to optimize our sample for a net treatment benefit significant at P = 0·01 by Cochran-Mantel-Haenszel test and by ordinal regression. For validation, we had these applied to the pooled randomized controlled trial data for 4·5-6 h, testing for net benefit by Cochran-Mantel-Haenszel test, ordinal regression, and also by dichotomized outcomes: modified Rankin score 0-1, mortality and parenchymal hemorrhage type 2 bleeds. All analyses were adjusted for age and National Institutes of Health Stroke Scale. In the training dataset, limits of 56-95 on a prognostic score retained 714 patients in whom there was net benefit significant at P = 0·01. When applied to the 1120 patients in the pooled randomized controlled trial 4·5-6 h dataset, score limits of 56-95 retained 711 patients and gave odds ratio for improved modified Rankin score distribution of 1·13, 95% confidence interval 0·87-1·47, Cochran-Mantel-Haenszel P = 0·89. More patients achieved modified Rankin score 0-1 (odds ratio 1·44, 1·02-2·05, P = 0·04) but mortality and parenchymal hemorrhage type 2 bleeds were increased: odds ratio 1·56, 1·01-2·40, P = 0·04; odds ratio 15·6, 3·7-65·8, P = 0·0002, respectively. Selection of patients between 4·5 and 6 h based on simple clinical measures failed to deliver a population in whom the alteplase effect would be safe

  19. Interfacing a General Purpose Fluid Network Flow Program with the SINDA/G Thermal Analysis Program

    Science.gov (United States)

    Schallhorn, Paul; Popok, Daniel

    1999-01-01

    A general purpose, one dimensional fluid flow code is currently being interfaced with the thermal analysis program Systems Improved Numerical Differencing Analyzer/Gaski (SINDA/G). The flow code, Generalized Fluid System Simulation Program (GFSSP), is capable of analyzing steady state and transient flow in a complex network. The flow code is capable of modeling several physical phenomena including compressibility effects, phase changes, body forces (such as gravity and centrifugal) and mixture thermodynamics for multiple species. The addition of GFSSP to SINDA/G provides a significant improvement in convective heat transfer modeling for SINDA/G. The interface development is conducted in multiple phases. This paper describes the first phase of the interface which allows for steady and quasi-steady (unsteady solid, steady fluid) conjugate heat transfer modeling.

  20. MGF Approach to the Analysis of Generalized Two-Ray Fading Models

    KAUST Repository

    Rao, Milind

    2015-01-01

    We analyze a class of Generalized Two-Ray (GTR) fading channels that consist of two line of sight (LOS) components with random phase plus a diffuse component. We derive a closedform expression for the moment generating function (MGF) of the signal-to-noise ratio (SNR) for this model, which greatly simplifies its analysis. This expression arises from the observation that the GTR fading model can be expressed in terms of a conditional underlying Rician distribution. We illustrate the approach to derive simple expressions for statistics and performance metrics of interest such as the amount of fading, the level crossing rate, the symbol error rate, and the ergodic capacity in GTR fading channels. We also show that the effect of considering a more general distribution for the phase difference between the LOS components has an impact on the average SNR.

  1. Extension of an Itô-based general approximation technique for random vibration of a BBW general hysteris model part II: Non-Gaussian analysis

    Science.gov (United States)

    Davoodi, H.; Noori, M.

    1990-07-01

    The work presented in this paper constitutes the second phase of on-going research aimed at developing mathematical models for representing general hysteretic behavior of structures and approximation techniques for the computation and analysis of the response of hysteretic systems to random excitations. In this second part, the technique previously developed by the authors for the Gaussian response analysis of non-linear systems with general hysteretic behavior is extended for the non-Gaussian analysis of these systems. This approximation technique is based on the approach proposed independently by Ibrahim and Wu-Lin. In this work up to fourth order moments of the response co-ordinates are obtained for the Bouc-Baber-Wen smooth hysteresis model. These higher order statistics previously have not been made available for general hysteresis models by using existing approximation methods. Second order moments obtained for the model by this non-Gaussian closure scheme are compared with equivalent linearization and Gaussian closure results via Monte Carlo simulation (MCS). Higher order moments are compared with the simulation results. The study performed for a wide range of degradation parameters and input power spectral density ( PSD) levels shows that the non-Gaussian responses obtained by this approach are in better agreement with the MCS results than the linearized and Gaussian ones. This approximation technique can provide information on higher order moments for general hysteretic systems. This information is valuable in random vibration and the reliability analysis of hysteretically yielding structures.

  2. Learning styles vary among general surgery residents: analysis of 12 years of data.

    Science.gov (United States)

    Mammen, Joshua M V; Fischer, David R; Anderson, Andrea; James, Laura E; Nussbaum, Michael S; Bower, Robert H; Pritts, Timothy A

    2007-01-01

    Understanding the learning styles of individuals may assist in the tailoring of an educational program to optimize learning. General surgery faculty and residents have been characterized previously as having a tendency toward particular learning styles. We seek to understand better the learning styles of general surgery residents and differences that may exist within the population. The Kolb Learning Style Inventory was administered yearly to general surgery residents at the University of Cincinnati from 1994 to 2006. This tool allows characterization of learning styles into 4 groups: converging, accommodating, assimilating, and diverging. The converging learning style involves education by actively solving problems. The accommodating learning style uses emotion and interpersonal relationships. The assimilating learning style learns by abstract logic. The diverging learning style learns best by observation. Chi-square analysis and analysis of variance were performed to determine significance. Surveys from 1994 to 2006 (91 residents, 325 responses) were analyzed. The prevalent learning style was converging (185, 57%), followed by assimilating (58, 18%), accommodating (44, 14%), and diverging (38, 12%). At the PGY 1 and 2 levels, male and female residents differed in learning style, with the accommodating learning style being relatively more frequent in women and assimilating learning style more frequent in men (Table 1, p basic science training or performance on the ABSIT/SBSE. Our data suggests that learning style differs between male and female general surgery residents but not with PGY level or ABSIT/SBSE performance. A greater understanding of individual learning styles may allow more refinement and tailoring of surgical programs.

  3. Termination of a fe/male transsexual patient's analysis: an example of general validity.

    Science.gov (United States)

    Quinodoz, Danielle

    2002-08-01

    The author describes the termination of an analysis, which, while relating to the particular case of a male-to-female transsexual patient, may be relevant to all analysts, particularly those whose patients need to integrate disavowed and split-off parts of themselves. The patient had undergone sex-change surgery at the age of 20. Having lived as a woman thereafter, she had asked for analysis some twenty years later. The author, who discussed the first three years of that analysis in an earlier paper, as well as her hesitation about undertaking it, considers that its termination after seven years illustrates not only the specific problems posed by transsexuals but also the general ones presented by "heterogeneous patients". To the best of her knowledge, this is the first published case history of a transsexual patient who has undergone surgery. In the author's view, the patient has acquired a new sense of internal unity based on a notion of sex differentiation in which mutual respect between the sexes has replaced confusion and mutual hate, and her quality of life has improved. On the general level, this termination shows how the reduction of paranoid-schizoid anxieties and the reintegration of split-off parts of the personality lead, as the depressive position is worked through, to a better toleration of internal contradictions, a new sense of cohesion of the self and a diminution of the fear of madness.

  4. Decision making in general practice: the availability and use of a specific laboratory analysis.

    Science.gov (United States)

    Fauli, Siri; Thue, Geir

    2005-01-01

    The aim of this investigation was to study the effect of general practitioners' (GP's) characteristics on two decisions: whether to have the Helicobacter pylori rapid test (HPRT) in the office laboratory and whether to use this test or a similar hospital-based serological test in a typical clinical situation described in a vignette. Discrete choice analysis with binary logit models were used to predict the probability that a general practice has the HPRT, as well as the GP's probability of using the HPRT or a similar test in this clinical situation. We found that the number of consultations per week has a positive effect on the probability of having the HPRT, indicating that the size of the practice affects the decision to have such a test in the repertoire. Furthermore, four variables significantly increased the probability of using one of the lab tests: more if located in urban practices, more by solo practitioners, more when the GP stated a high probability for H. pylori associated disease, and more when the GP had the rapid test available in the practice. In our analysis, the remuneration system is endogenous and does not have a significant effect on the two decisions. Our study demonstrates that characteristics of the GP affect the availability and use of a specific laboratory analysis.

  5. Exploratory spatial analysis of pilot fatality rates in general aviation crashes using geographic information systems.

    Science.gov (United States)

    Grabowski, Jurek G; Curriero, Frank C; Baker, Susan P; Li, Guohua

    2002-03-01

    Geographic information systems and exploratory spatial analysis were used to describe the geographic characteristics of pilot fatality rates in 1983-1998 general aviation crashes within the continental United States. The authors plotted crash sites on a digital map; rates were computed at regular grid intersections and then interpolated by using geographic information systems. A test for significance was performed by using Monte Carlo simulations. Further analysis compared low-, medium-, and high-rate areas in relation to pilot characteristics, aircraft type, and crash circumstance. Of the 14,051 general aviation crashes studied, 31% were fatal. Seventy-four geographic areas were categorized as having low fatality rates and 53 as having high fatality rates. High-fatality-rate areas tended to be mountainous, such as the Rocky Mountains and the Appalachian region, whereas low-rate areas were relatively flat, such as the Great Plains. Further analysis comparing low-, medium-, and high-fatality-rate areas revealed that crashes in high-fatality-rate areas were more likely than crashes in other areas to have occurred under instrument meteorologic conditions and to involve aircraft fire. This study demonstrates that geographic information systems are a valuable tool for injury prevention and aviation safety research.

  6. The prevalence of insomnia in the general population in China: A meta-analysis.

    Directory of Open Access Journals (Sweden)

    Xiao-Lan Cao

    Full Text Available This is the first meta-analysis of the pooled prevalence of insomnia in the general population of China. A systematic literature search was conducted via the following databases: PubMed, PsycINFO, EMBASE and Chinese databases (China National Knowledge Interne (CNKI, WanFang Data and SinoMed. Statistical analyses were performed using the Comprehensive Meta-Analysis program. A total of 17 studies with 115,988 participants met the inclusion criteria for the analysis. The pooled prevalence of insomnia in China was 15.0% (95% Confidence interval [CI]: 12.1%-18.5%. No significant difference was found in the prevalence between genders or across time period. The pooled prevalence of insomnia in population with a mean age of 43.7 years and older (11.6%; 95% CI: 7.5%-17.6% was significantly lower than in those with a mean age younger than 43.7 years (20.4%; 95% CI: 14.2%-28.2%. The prevalence of insomnia was significantly affected by the type of assessment tools (Q = 14.1, P = 0.001. The general population prevalence of insomnia in China is lower than those reported in Western countries but similar to those in Asian countries. Younger Chinese adults appear to suffer from more insomnia than older adults.CRD 42016043620.

  7. Evaluation of scaling and root planing effect in generalized chronic periodontitis by fractal and multifractal analysis.

    Science.gov (United States)

    Pârvu, A E; Ţălu, Ş; Crăciun, C; Alb, S F

    2014-04-01

    Fractal and multifractal analysis are useful additional non-invasive methods for quantitative description of complex morphological features. However, the quantitative and qualitative assessment of morphologic changes within human gingival cells and tissues are still unexplored. The aim of this work is to assess the structural gingival changes in patients with generalized chronic periodontitis (GCP), before and after scaling and root planing (SRP) by using fractal and multifractal analysis. Twelve adults with untreated chronic periodontitis were treated only by SRP. At baseline and after SRP, gingivomucosal biopsies were collected for histopathological examination. Fractal and multifractal analysis of digital images of the granular, spinous and basal and conjunctive layers structure, using the standard box-counting method was performed. The fractal dimension was determined for cell membrane, nuclear membrane of cell and nucleolus membrane of cell. In GCP a higher fractal dimension corresponds to a higher geometric complexity of cells contour, as its values increase when the contour irregularities increase. The generalized fractal dimensions were determined for the conjunctive layer structure of patients with GCP and patients with GCP and SRP. The fractal and multifractal analysis of gingival biopsies confirmed earlier findings that SRP reduces gingival injury in patients with GCP. It has been shown that fractal and multifractal analysis of tissue images as a non-invasive technique could be used to measure contrasting morphologic changes within human gingival cells and tissues and can provide detailed information for investigation of healthy and diseased gingival mucosa from patients with GCP. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Cost analysis of spinal and general anesthesia for the surgical treatment of lumbar spondylosis.

    Science.gov (United States)

    Walcott, Brian P; Khanna, Arjun; Yanamadala, Vijay; Coumans, Jean-Valery; Peterfreund, Robert A

    2015-03-01

    Lumbar spine surgery is typically performed under general anesthesia, although spinal anesthesia can also be used. Given the prevalence of lumbar spine surgery, small differences in cost between the two anesthetic techniques have the potential to make a large impact on overall healthcare costs. We sought to perform a cost comparison analysis of spinal versus general anesthesia for lumbar spine operations. Following Institutional Review Board approval, a retrospective cohort study was performed from 2009-2012 on consecutive patients undergoing non-instrumented, elective lumbar spine surgery for spondylosis by a single surgeon. Each patient was evaluated for both types of anesthesia, with the decision for anesthetic method being made based on a combination of physical status, anatomical considerations, and ultimately a consensus agreement between patient, surgeon, and anesthesiologist. Patient demographics and clinical characteristics were compared between the two groups. Operating room costs were calculated whilst blinded to clinical outcomes and reported in percentage difference. General anesthesia (n=319) and spinal anesthesia (n=81) patients had significantly different median operative times of 175 ± 39.08 and 158 ± 32.75 minutes, respectively (p<0.001, Mann-Whitney U test). Operating room costs were 10.33% higher for general anesthesia compared to spinal anesthesia (p=0.003, Mann-Whitney U test). Complications of spinal anesthesia included excessive movement (n=1), failed spinal attempt (n=3), intraoperative conversion to general anesthesia (n=2), and a high spinal level (n=1). In conclusion, spinal anesthesia can be performed safely in patients undergoing lumbar spine surgery. It has the potential to reduce operative times, costs, and possibly, complications. Further prospective evaluation will help to validate these findings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. The Application of the Homotopy Perturbation Method and the Homotopy Analysis Method to the Generalized Zakharov Equations

    OpenAIRE

    Zedan, Hassan A.; El Adrous, Eman

    2012-01-01

    We introduce two powerful methods to solve the generalized Zakharov equations; one is the homotopy perturbation method and the other is the homotopy analysis method. The homotopy perturbation method is proposed for solving the generalized Zakharov equations. The initial approximations can be freely chosen with possible unknown constants which can be determined by imposing the boundary and initial conditions; the homotopy analysis method is applied to solve the generalized Zakharov equations. ...

  10. Lead optimization attrition analysis (LOAA): a novel and general methodology for medicinal chemistry.

    Science.gov (United States)

    Munson, Mark; Lieberman, Harvey; Tserlin, Elina; Rocnik, Jennifer; Ge, Jie; Fitzgerald, Maria; Patel, Vinod; Garcia-Echeverria, Carlos

    2015-08-01

    Herein, we report a novel and general method, lead optimization attrition analysis (LOAA), to benchmark two distinct small-molecule lead series using a relatively unbiased, simple technique and commercially available software. We illustrate this approach with data collected during lead optimization of two independent oncology programs as a case study. Easily generated graphics and attrition curves enabled us to calibrate progress and support go/no go decisions on each program. We believe that this data-driven technique could be used broadly by medicinal chemists and management to guide strategic decisions during drug discovery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. A Performance Analysis of Evolutionary Pattern Search with Generalized Mutation Steps

    Energy Technology Data Exchange (ETDEWEB)

    Hart, W.; Hunter, K.

    1999-02-10

    Evolutionary pattern search algorithms (EPSAs) are a class of evolutionary algorithms (EAs) that have convergence guarantees on a broad class of nonconvex continuous problems. In previous work we have analyzed the empirical performance of EPSAs. This paper revisits that analysis and extends it to a more general model of mutation. We experimentally evaluate how the choice of the set of mutation offsets affects optimization performance for EPSAs. Additionally, we compare EPSAs to self-adaptive EAs with respect to robustness and rate of optimization. All experiments employ a suite of test functions representing a range of modality and number of multiple minima.

  12. Algorithmic analysis of the maximum level length in general-block two-dimensional Markov processes

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Two-dimensional continuous-time Markov chains (CTMCs are useful tools for studying stochastic models such as queueing, inventory, and production systems. Of particular interest in this paper is the distribution of the maximal level visited in a busy period because this descriptor provides an excellent measure of the system congestion. We present an algorithmic analysis for the computation of its distribution which is valid for Markov chains with general-block structure. For a multiserver batch arrival queue with retrials and negative arrivals, we exploit the underlying internal block structure and present numerical examples that reveal some interesting facts of the system.

  13. Stability and bifurcation analysis of a generalized scalar delay differential equation.

    Science.gov (United States)

    Bhalekar, Sachin

    2016-08-01

    This paper deals with the stability and bifurcation analysis of a general form of equation D(α)x(t)=g(x(t),x(t-τ)) involving the derivative of order α ∈ (0, 1] and a constant delay τ ≥ 0. The stability of equilibrium points is presented in terms of the stability regions and critical surfaces. We provide a necessary condition to exist chaos in the system also. A wide range of delay differential equations involving a constant delay can be analyzed using the results proposed in this paper. The illustrative examples are provided to explain the theory.

  14. Regularized generalized eigen-decomposition with applications to sparse supervised feature extraction and sparse discriminant analysis

    DEFF Research Database (Denmark)

    Han, Xixuan; Clemmensen, Line Katrine Harder

    2015-01-01

    , and it is formulated as a generalized eigenvalue problem. Thus RGED can be applied to effectively extract sparse features and calculate sparse discriminant directions for all variants of Fisher discriminant criterion based models. Particularly, RGED can be applied to matrix-based and even tensor-based discriminant...... techniques, for instance, 2D-Linear Discriminant Analysis (2D-LDA). Furthermore, an iterative algorithm based on the alternating direction method of multipliers is developed. The algorithm approximately solves RGED with monotonically decreasing convergence and at an acceptable speed for results of modest...

  15. Williams Element with Generalized Degrees of Freedom for Fracture Analysis of Multiple-Cracked Beam

    Science.gov (United States)

    Xu, Hua; Wei, Quyang; Yang, Lufeng

    2017-10-01

    In this paper, the method of finite element with generalized degrees of freedom (FEDOFs) is used to calculate the stress intensity factor (SIF) of multiple cracked beam and analysed the effect of minor cracks on the main crack SIF in different cases. Williams element is insensitive to the size of singular region. So that calculation efficiency is highly improved. Examples analysis validates that the SIF near the crack tip can be obtained directly though FEDOFs. And the result is well consistent with ANSYS solution and has a satisfied accuracy.

  16. Development of a large-scale general purpose two-phase flow analysis code

    International Nuclear Information System (INIS)

    Terasaka, Haruo; Shimizu, Sensuke

    2001-01-01

    A general purpose three-dimensional two-phase flow analysis code has been developed for solving large-scale problems in industrial fields. The code uses a two-fluid model to describe the conservation equations for two-phase flow in order to be applicable to various phenomena. Complicated geometrical conditions are modeled by FAVOR method in structured grid systems, and the discretization equations are solved by a modified SIMPLEST scheme. To reduce computing time a matrix solver for the pressure correction equation is parallelized with OpenMP. Results of numerical examples show that the accurate solutions can be obtained efficiently and stably. (author)

  17. General structure of the GRAND program for analysis of the data from a neutrino detector

    International Nuclear Information System (INIS)

    Zhigunov, V.P.; Kulikov, V.A.; Mukhin, S.A.; Naumov, V.L.; Platonov, V.G.; Spiridonov, A.A.

    1985-01-01

    The general structure of the GRAND (Global Result Analysis for Neutrino Detector) program used for geometrical and kinematic reconstruction of events recorded by a neutrino detector is considered. The detector consists of a calorimeter-target, a shower electron and γ detector and a magnetic spectrometer. While developing the GRAND program the multivariance (different types of the computers used), availability of various algorithms for solving the same problem, solution of separate particlular problems within the frames of one program are taken into account. The KERNLIB library and the HBOOK, ZBOOK, EPIO and FFREAD subroutine packages are used while creating the program as basic libraries

  18. A comparison between fault tree analysis and reliability graph with general gates

    International Nuclear Information System (INIS)

    Kim, Man Cheol; Seong, Poong Hyun; Jung, Woo Sik

    2004-01-01

    Currently, level-1 probabilistic safety assessment (PSA) is performed on the basis of event tree analysis and fault tree analysis. Kim and Seong developed a new method for system reliability analysis named reliability graph with general gates (RGGG). The RGGG is an extension of conventional reliability graph, and it utilizes the transformation of system structures to equivalent Bayesian networks for quantitative calculation. The RGGG is considered to be intuitive and easy-to-use while as powerful as fault tree analysis. As an example, Kim and Seong already showed that the Bayesian network model for digital plant protection system (DPPS), which is transformed from the RGGG model for DPPS, can be shown in 1 page, while the fault tree model for DPPS consists of 64 pages of fault trees. Kim and Seong also insisted that Bayesian network model for DPPS is more intuitive because the one-to-one matching between each node in the Bayesian network model and an actual component of DPPS is possible. In this paper, we are going to give a comparison between fault tree analysis and the RGGG method with two example systems. The two example systems are the recirculation of in Korean standard nuclear power plants (KSNP) and the fault tree model developed by Rauzy

  19. Analysis of general and specific combining abilities of popcorn populations, including selfed parents

    Directory of Open Access Journals (Sweden)

    José Marcelo Soriano Viana

    2003-12-01

    Full Text Available Estimation of general and specific combining ability effects in a diallel analysis of cross-pollinating populations, including the selfed parents, is presented in this work. The restrictions considered satisfy the parametric values of the GCA and SCA effects. The method is extended to self-pollinating populations (suitable for other species, without the selfed parents. The analysis of changes in population means due to inbreeding (sensitivity to inbreeding also permits to assess the predominant direction of dominance deviations and the relative genetic variability in each parent population. The methodology was used to select popcorn populations for intra- and inter-population breeding programs and for hybrid production, developed at the Federal University of Viçosa, MG, Brazil. Two yellow pearl grain popcorn populations were selected.

  20. Time series analysis of wind speed using VAR and the generalized impulse response technique

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, Bradley T. [Area of Information Systems and Quantitative Sciences, Rawls College of Business and Wind Science and Engineering Research Center, Texas Tech University, Lubbock, TX 79409-2101 (United States); Kruse, Jamie Brown [Center for Natural Hazard Research, East Carolina University, Greenville, NC (United States); Schroeder, John L. [Department of Geosciences and Wind Science and Engineering Research Center, Texas Tech University, Lubbock, TX (United States); Smith, Douglas A. [Department of Civil Engineering and Wind Science and Engineering Research Center, Texas Tech University, Lubbock, TX (United States)

    2007-03-15

    This research examines the interdependence in time series wind speed data measured in the same location at four different heights. A multiple-equation system known as a vector autoregression is proposed for characterizing the time series dynamics of wind. Additionally, the recently developed method of generalized impulse response analysis provides insight into the cross-effects of the wind series and their responses to shocks. Findings are based on analysis of contemporaneous wind speed time histories taken at 13, 33, 70 and 160 ft above ground level with a sampling rate of 10 Hz. The results indicate that wind speeds measured at 70 ft was the most variable. Further, the turbulence persisted longer at the 70-ft measurement than at the other heights. The greatest interdependence is observed at 13 ft. Gusts at 160 ft led to the greatest persistence to an 'own' shock and led to greatest persistence in the responses of the other wind series. (author)

  1. Overlap between the general factor of personality and emotional intelligence: A meta-analysis.

    Science.gov (United States)

    van der Linden, Dimitri; Pekaar, Keri A; Bakker, Arnold B; Schermer, Julie Aitken; Vernon, Philip A; Dunkel, Curtis S; Petrides, K V

    2017-01-01

    We examine the relationship between the general factor of personality (GFP) and emotional intelligence (EI) and specifically test the hypothesis that the GFP is a social effectiveness factor overlapping conceptually with EI. Presented is an extensive meta-analysis in which the associations between the GFP, extracted from the Big Five dimensions, with various EI measures is examined. Based on a total sample of k = 142 data sources (N = 36,268) the 2 major findings from the meta-analysis were (a) a large overlap between the GFP and trait EI (r ≈ .85); and (b) a positive, but more moderate, correlation with ability EI (r ≈ .28). These findings show that high-GFP individuals score higher on trait and ability EI, supporting the notion that the GFP is a social effectiveness factor. The findings also suggest that the GFP is very similar, perhaps even synonymous, to trait EI. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  2. A general symplectic method for the response analysis of infinitely periodic structures subjected to random excitations

    Directory of Open Access Journals (Sweden)

    You-Wei Zhang

    Full Text Available A general symplectic method for the random response analysis of infinitely periodic structures subjected to stationary/non-stationary random excitations is developed using symplectic mathematics in conjunction with variable separation and the pseudo-excitation method (PEM. Starting from the equation of motion for a single loaded substructure, symplectic analysis is firstly used to eliminate the dependent degrees of the freedom through condensation. A Fourier expansion of the condensed equation of motion is then applied to separate the variables of time and wave number, thus enabling the necessary recurrence scheme to be developed. The random response is finally determined by implementing PEM. The proposed method is justified by comparison with results available in the literature and is then applied to a more complicated time-dependent coupled system.

  3. Awareness, Analysis, and Action: Curricular Alignment for Student Success in General Chemistry

    Science.gov (United States)

    2018-01-01

    This article examines the ways that a shared faculty experience across five partner institutions led to a deep awareness of the curriculum and pedagogy of general chemistry coursework, and ultimately, to a collaborative action plan for student success. The team identified key differences and similarities in course content and instructional experiences. The comparative analysis yielded many more similarities than differences, and therefore, the team shifted its focus from “gap analysis” to an exploration of common curricular challenges. To address these challenges, the team developed content for targeted instructional resources that promoted the success of all STEM students across institutions. This article contextualizes the interinstitutional collaboration and closely examines the interactive components (awareness, analysis, and action), critical tools, and productive attitudes that undergirded the curricular alignment process of the STEM Transfer Student Success Initiative (t-STEM). PMID:29657334

  4. Current contraceptive management in Australian general practice: an analysis of BEACH data.

    Science.gov (United States)

    Mazza, Danielle; Harrison, Christopher; Taft, Angela; Brijnath, Bianca; Britt, Helena; Hobbs, Melissa; Stewart, Kay; Hussainy, Safeera

    2012-07-16

    To determine current contraceptive management by general practitioners in Australia. Analysis of data from a random sample of 3910 Australian GPs who participated in the Bettering the Evaluation and Care of Health (BEACH) survey, a continuous cross-sectional survey of GP activity, between April 2007 and March 2011. Consultations with female patients aged 12-54 years that involved all forms of contraception were analysed. GP and patient characteristics associated with the management of contraception; types of contraception used; rates of encounters involving emergency contraception. Increased age, ethnicity, Indigenous status and holding a Commonwealth Health Care Card were significantly associated with low rates of encounters involving management of contraception. The combined oral contraceptive pill was the most frequently prescribed method of contraception, with moderate prescription of long-acting reversible contraception (LARC), especially among women aged 34-54 years. Rates of consultations concerned with emergency contraception were low, but involved high rates of counselling, advice or education (48%) compared with encounters for general contraception (> 20%). A shift towards prescribing LARC, as recommended in clinical guidelines, has yet to occur in Australian general practice. Better understanding of patient and GP perspectives on contraceptive choices could lead to more effective contraceptive use.

  5. Analysis of Loss of Control Parameters for Aircraft Maneuvering in General Aviation

    Directory of Open Access Journals (Sweden)

    Sameer Ud-Din

    2018-01-01

    Full Text Available A rapid increase in the occurrence of loss of control in general aviation has raised concern in recent years. Loss of control (LOC pertains to unique characteristics in which external and internal events act in conjunction. The Federal Aviation Administration (FAA has approved an Integrated Safety Assessment Model (ISAM for evaluating safety in the National Airspace System (NAS. ISAM consists of an event sequence diagram (ESD with fault trees containing numerous parameters, which is recognized as casual risk model. In this paper, we outline an integrated risk assessment framework to model maneuvering through cross-examining external and internal events. The maneuvering is in the critical flight phase with a high number of LOC occurrences in general aviation, where highly trained and qualified pilots failed to maintain aircraft control irrespective of the preventive nature of the events. Various metrics have been presented for evaluating the significance of these parameters to identify the most important ones. The proposed sensitivity analysis considers the accident, fatality, and risk reduction frequencies that assist in the decision-making process and foresees future risks from a general aviation perspective.

  6. Generalized Feature Extraction for Wrist Pulse Analysis: From 1-D Time Series to 2-D Matrix.

    Science.gov (United States)

    Dimin Wang; Zhang, David; Guangming Lu

    2017-07-01

    Traditional Chinese pulse diagnosis, known as an empirical science, depends on the subjective experience. Inconsistent diagnostic results may be obtained among different practitioners. A scientific way of studying the pulse should be to analyze the objectified wrist pulse waveforms. In recent years, many pulse acquisition platforms have been developed with the advances in sensor and computer technology. And the pulse diagnosis using pattern recognition theories is also increasingly attracting attentions. Though many literatures on pulse feature extraction have been published, they just handle the pulse signals as simple 1-D time series and ignore the information within the class. This paper presents a generalized method of pulse feature extraction, extending the feature dimension from 1-D time series to 2-D matrix. The conventional wrist pulse features correspond to a particular case of the generalized models. The proposed method is validated through pattern classification on actual pulse records. Both quantitative and qualitative results relative to the 1-D pulse features are given through diabetes diagnosis. The experimental results show that the generalized 2-D matrix feature is effective in extracting both the periodic and nonperiodic information. And it is practical for wrist pulse analysis.

  7. BOUNDED RATIONALITY: AN ANALYSIS OF TEACHING MANUALS OF MANAGEMENT GENERAL THEORY

    Directory of Open Access Journals (Sweden)

    Daniela Teixeira Dias

    2016-08-01

    Full Text Available The objective of this article was to analyze how the concept of bounded rationality has been treated in the educational manuals of General Theory of Management, with the objective to analyze its quality, in terms of quality and complexity. Therefore, three educational manuals provided by the Central Library of the Alfa Federal University were used: “General Theory of Administration” authored by Motta and Vasconcelos (Manual A; “Introduction to Management” by Chiavenato (Manual B, and “Management: Theory and Processes” by Caravantes, Caravantes, and Kloeckener (Manual C. These were observed from the content analysis in four dimensions defined a priori: delimitation of the approach and quality of the references; historical-concrete dimension; relationship dimension; and theoretical dimension. The results showed that all manuals presented considerations about the bounded rationality assumption and made reference to Simon and Barnard, although they have not discussed their work and their contribution more widely. Manual A was the most complete in the axes analysis herein. Manual B turned to a summarized and synthetic theoretical discussion. Whereas C Manual defined and conceptualized bounded rationality and was the only one to describe the types of rationality presented by Simon.

  8. Generalized renewal process for analysis of repairable systems with limited failure experience

    International Nuclear Information System (INIS)

    Yanez, Medardo; Joglar, Francisco; Modarres, Mohammad

    2002-01-01

    Repairable systems can be brought to one of possible states following a repair. These states are: 'as good as new', 'as bad as old', 'better than old but worse than new', 'better than new', and 'worse than old'. The probabilistic models traditionally used to estimate the expected number of failures account for the first two states, but they do not properly apply to the last three, which are more realistic in practice. In this paper, a robust solution to a probabilistic model that is applicable to all of the five after repair states, called generalized renewal process (GRP), is presented. This research demonstrates that the GRP offers a general approach to modeling repairable systems and discusses application of the classical maximum likelihood and Bayesian approaches to estimation of the GRP parameters. This paper also presents a review of the traditional approaches to the analysis of repairable systems as well as some applications of the GRP and shows that they are subsets of the GRP approach. It is shown that the proposed GRP solution accurately describes the failure data, even when a small amount of failure data is available. Recent emphasis in the use of performance-based analysis in operation and regulation of complex engineering systems (such as those in space and process industries) require use of sound models for predicting failures based on the past performance of the systems. The GRP solution in this paper is a promising and efficient approach for such performance-based applications

  9. A comparative analysis of exposure doses between the radiation workers in dental and general hospital

    International Nuclear Information System (INIS)

    Yang, Nam Hee; Chung, Woon Kwan; Dong, Kyung Rae; Ju, Yong Jin; Song, Ha Jin; Choi, Eun Jin

    2015-01-01

    Research and investigation is required for the exposure dose of radiation workers to work in the dental hospital as increasing interest in exposure dose of the dental hospital recently accordingly, study aim to minimize radiation exposure by making a follow-up study of individual exposure doses of radiation workers, analyzing the status on individual radiation exposure management, prediction the radiation disability risk levels by radiation, and alerting the workers to the danger of radiation exposure. Especially given the changes in the dental hospital radiation safety awareness conducted the study in order to minimize radiation exposure. This study performed analyses by a comparison between general and dental hospital, comparing each occupation, with the 116,220 exposure dose data by quarter and year of 5,811 subjects at general and dental hospital across South Korea from January 1, 2008 through December 31, 2012. The following are the results obtained by analyzing average values year and quarter. In term of hospital, average doses were significantly higher in general hospitals than detal ones. In terms of job, average doses were higher in radiological technologists the other workers. Especially, they showed statistically significant differences between radiological technologists than dentists. The above-mentioned results indicate that radiation workers were exposed to radiation for the past 5 years to the extent not exceeding the dose limit (maximum 50 mSv y -1 ). The limitation of this study is that radiation workers before 2008 were excluded from the study. Objective evaluation standards did not apply to the work circumstance or condition of each hospital. Therefore, it is deemed necessary to work out analysis criteria that will be used as objective evaluation standard. It will be necessary to study radiation exposure in more precise ways on the basis of objective analysis standard in the future. Should try to minimize the radiation individual dose of

  10. All-sky analysis of the general relativistic galaxy power spectrum

    Science.gov (United States)

    Yoo, Jaiyul; Desjacques, Vincent

    2013-07-01

    We perform an all-sky analysis of the general relativistic galaxy power spectrum using the well-developed spherical Fourier decomposition. Spherical Fourier analysis expresses the observed galaxy fluctuation in terms of the spherical harmonics and spherical Bessel functions that are angular and radial eigenfunctions of the Helmholtz equation, providing a natural orthogonal basis for all-sky analysis of the large-scale mode measurements. Accounting for all the relativistic effects in galaxy clustering, we compute the spherical power spectrum and its covariance matrix and compare it to the standard three-dimensional power spectrum to establish a connection. The spherical power spectrum recovers the three-dimensional power spectrum at each wave number k with its angular dependence μk encoded in angular multipole l, and the contributions of the line-of-sight projection to galaxy clustering such as the gravitational lensing effect can be readily accommodated in the spherical Fourier analysis. A complete list of formulas for computing the relativistic spherical galaxy power spectrum is also presented.

  11. Using Generalized Linear Mixed Models to Evaluate Inconsistency within a Network Meta-Analysis.

    Science.gov (United States)

    Tu, Yu-Kang

    2015-12-01

    Network meta-analysis compares multiple treatments by incorporating direct and indirect evidence into a general statistical framework. One issue with the validity of network meta-analysis is inconsistency between direct and indirect evidence within a loop formed by three treatments. Recently, the inconsistency issue has been explored further and a complex design-by-treatment interaction model proposed. The aim of this article was to show how to evaluate the design-by-treatment interaction model using the generalized linear mixed model. We proposed an arm-based approach to evaluating the design-by-treatment inconsistency, which is flexible in modeling different types of outcome variables. We used the smoking cessation data to compare results from our arm-based approach with those from the standard contrast-based approach. Because the contrast-based approach requires transformation of data, our example showed that such a transformation may yield biases in the treatment effect and inconsistency evaluation, when event rates were low in some treatments. We also compared contrast-based and arm-based models in the evaluation of design inconsistency when different heterogeneity variances were estimated, and the arm-based model yielded more accurate results. Because some statistical software commands can detect the collinearity among variables and automatically remove the redundant ones, we can use this advantage to help with placing the inconsistency parameters. This could be very useful for a network meta-analysis involving many designs and treatments. Copyright © 2015 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  12. Sensitivity analysis of thermodynamic properties of liquid water: a general approach to improve empirical potentials.

    Science.gov (United States)

    Iordanov, Tzvetelin D; Schenter, Gregory K; Garrett, Bruce C

    2006-01-19

    A sensitivity analysis of bulk water thermodynamics is presented in an effort to understand the relation between qualitative features of molecular potentials and properties that they predict. The analysis is incorporated in molecular dynamics simulations and investigates the sensitivity of the Helmholtz free energy, internal energy, entropy, heat capacity, pressure, thermal pressure coefficient, and static dielectric constant to components of the potential rather than the parameters of a given functional form. The sensitivities of the properties are calculated with respect to the van der Waals repulsive and the attractive parts, plus short- and long-range Coulomb parts of three four site empirical water potentials: TIP4P, Dang-Chang and TTM2R. The polarization sensitivity is calculated for the polarizable Dang-Chang and TTM2R potentials. This new type of analysis allows direct comparisons of the sensitivities for different potentials that use different functional forms. The analysis indicates that all investigated properties are most sensitive to the van der Waals repulsive, the short-range Coulomb and the polarization components of the potentials. When polarization is included in the potentials, the magnitude of the sensitivity of the Helmholtz free energy, internal energy, and entropy with respect to this part of the potential is comparable in magnitude to the other electrostatic components. In addition similarities in trends of observed sensitivities for nonpolarizable and polarizable potentials lead to the conclusion that the complexity of the model is not of critical importance for the calculation of these thermodynamic properties for bulk water. The van der Waals attractive and the long-range Coulomb sensitivities are relatively small for the entropy, heat capacity, thermal pressure coefficient and the static dielectric constant, while small changes in any of the potential contributions will significantly affect the pressure. The analysis suggests a procedure

  13. Generalized functions and Fourier analysis dedicated to Stevan Pilipović on the occasion of his 65th birthday

    CERN Document Server

    Toft, Joachim; Vindas, Jasson; Wahlberg, Patrik

    2017-01-01

    This book gives an excellent and up-to-date overview on the convergence and joint progress in the fields of Generalized Functions and Fourier Analysis, notably in the core disciplines of pseudodifferential operators, microlocal analysis and time-frequency analysis. The volume is a collection of chapters addressing these fields, their interaction, their unifying concepts and their applications and is based on scientific activities related to the International Association for Generalized Functions (IAGF) and the ISAAC interest groups on Pseudo-Differential Operators (IGPDO) and on Generalized Functions (IGGF), notably on the longstanding collaboration of these groups within ISAAC.

  14. A General Framework for Multivariate Analysis with Optimal Scaling: The R Package aspect

    Directory of Open Access Journals (Sweden)

    Patrick Mair

    2009-11-01

    Full Text Available In a series of papers De Leeuw developed a general framework for multivariate analysis with optimal scaling. The basic idea of optimal scaling is to transform the observed variables (categories in terms of quantifications. In the approach presented here the multivariate data are collected into a multivariable. An aspect of a multivariable is a function that is used to measure how well the multivariable satisfies some criterion. Basically we can think of two different families of aspects which unify many well-known multivariate methods: Correlational aspects based on sums of correlations, eigenvalues and determinants which unify multiple regression, path analysis, correspondence analysis, nonlinear PCA, etc. Non-correlational aspects which linearize bivariate regressions and can be used for SEM preprocessing with categorical data. Additionally, other aspects can be established that do not correspond to classical techniques at all. By means of the R package aspect we provide a unified majorization-based implementation of this methodology. Using various data examples we will show the flexibility of this approach and how the optimally scaled results can be represented using graphical tools provided by the package.

  15. Textual Analysis of General Surgery Residency Personal Statements: Topics and Gender Differences.

    Science.gov (United States)

    Ostapenko, Laura; Schonhardt-Bailey, Cheryl; Sublette, Jessica Walling; Smink, Douglas S; Osman, Nora Y

    2017-10-25

    Applicants to US general surgery residency training programs submit standardized applications. Applicants use the personal statement to express their individual rationale for a career in surgery. Our research explores common topics and gender differences within the personal statements of general surgery applicants. We analyzed the electronic residency application service personal statements of 578 applicants (containing 3,82,405 words) from Liaison Committee on Medical Education-accredited medical schools to a single ACGME-accredited general surgery program using an automated textual analysis program to identify common topics and gender differences. Using a recursive algorithm, the program identified common words and clusters, grouping them into topic classes, which are internally validated. We identified and labeled 8 statistically significant topic classes through independent review: "my story," "the art of surgery," "clinical vignettes," "why I love surgery," "residency program characteristics," "working as a team," "academics and research," and "global health and policy." Although some classes were common to all applications, we also identified gender-specific differences. Notably, women were significantly more likely than men to be represented within the class of "working as a team." (p differences between the statements of men and women. Women were more likely to discuss surgery as a team endeavor while men were more likely to focus on the details of their surgical experiences. Our work mirrors what has been found in social psychology research on gender-based differences in how men and women communicate their career goals and aspirations in other competitive professional situations. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  16. Responses to clinical uncertainty in Australian general practice trainees: a cross-sectional analysis.

    Science.gov (United States)

    Cooke, Georga; Tapley, Amanda; Holliday, Elizabeth; Morgan, Simon; Henderson, Kim; Ball, Jean; van Driel, Mieke; Spike, Neil; Kerr, Rohan; Magin, Parker

    2017-12-01

    Tolerance for ambiguity is essential for optimal learning and professional competence. General practice trainees must be, or must learn to be, adept at managing clinical uncertainty. However, few studies have examined associations of intolerance of uncertainty in this group. The aim of this study was to establish levels of tolerance of uncertainty in Australian general practice trainees and associations of uncertainty with demographic, educational and training practice factors. A cross-sectional analysis was performed on the Registrar Clinical Encounters in Training (ReCEnT) project, an ongoing multi-site cohort study. Scores on three of the four independent subscales of the Physicians' Reaction to Uncertainty (PRU) instrument were analysed as outcome variables in linear regression models with trainee and practice factors as independent variables. A total of 594 trainees contributed data on a total of 1209 occasions. Trainees in earlier training terms had higher scores for 'Anxiety due to uncertainty', 'Concern about bad outcomes' and 'Reluctance to disclose diagnosis/treatment uncertainty to patients'. Beyond this, findings suggest two distinct sets of associations regarding reaction to uncertainty. Firstly, affective aspects of uncertainty (the 'Anxiety' and 'Concern' subscales) were associated with female gender, less experience in hospital prior to commencing general practice training, and graduation overseas. Secondly, a maladaptive response to uncertainty (the 'Reluctance to disclose' subscale) was associated with urban practice, health qualifications prior to studying medicine, practice in an area of higher socio-economic status, and being Australian-trained. This study has established levels of three measures of trainees' responses to uncertainty and associations with these responses. The current findings suggest differing 'phenotypes' of trainees with high 'affective' responses to uncertainty and those reluctant to disclose uncertainty to patients. More

  17. Higher moments method for generalized Pareto distribution in flood frequency analysis

    Science.gov (United States)

    Zhou, C. R.; Chen, Y. F.; Huang, Q.; Gu, S. H.

    2017-08-01

    The generalized Pareto distribution (GPD) has proven to be the ideal distribution in fitting with the peak over threshold series in flood frequency analysis. Several moments-based estimators are applied to estimating the parameters of GPD. Higher linear moments (LH moments) and higher probability weighted moments (HPWM) are the linear combinations of Probability Weighted Moments (PWM). In this study, the relationship between them will be explored. A series of statistical experiments and a case study are used to compare their performances. The results show that if the same PWM are used in LH moments and HPWM methods, the parameter estimated by these two methods is unbiased. Particularly, when the same PWM are used, the PWM method (or the HPWM method when the order equals 0) shows identical results in parameter estimation with the linear Moments (L-Moments) method. Additionally, this phenomenon is significant when r ≥ 1 that the same order PWM are used in HPWM and LH moments method.

  18. Generalized Tensor Analysis Model for Multi-Subcarrier Analog Optical Systems

    DEFF Research Database (Denmark)

    Zhao, Ying; Yu, Xianbin; Zheng, Xiaoping

    2011-01-01

    We propose and develop a general tensor analysis framework for a subcarrier multiplex analog optical fiber link for applications in microwave photonics. The goal of this work is to construct an uniform method to address nonlinear distortions of a discrete frequency transmission system. We employ....... In addition, it is demonstrated that each corresponding tensor is formally determined by device structures, which allows for a synthesized study of device combinations more systematically. For implementing numerical methods, the practical significance of the tensor model is it simplifies the derivation...... details compared with series-based approaches by hiding the underlying multi-fold summation and index operation. The integrity of the proposed methodology is validated by investigating the classical intensity modulated system. Furthermore, to give an application model of the tensor formalism, we make...

  19. How to Measure Quality of Service Using Unstructured Data Analysis: A General Method Design

    Directory of Open Access Journals (Sweden)

    Lucie Sperková,

    2015-10-01

    Full Text Available The aim of the paper is to design a general method usable for measuring the quality of the service from the customer’s point of view with the help of content analytics. Large amount of unstructured data is created by customers of the service. This data can provide a valuable feedback from the service usage. Customers talk among themselves about their experiences and feelings from consumption of the service. The design of the method is based on a systematic literature review in the area of the service quality and unstructured data analysis. Analytics and quality measurement models are collected and critically evaluated regarding their potential use for measuring IT service quality. The method can be used by IT service provider to measure and monitor service quality based on World-of-Mouth in order to continual service improvement.

  20. Analysis of linear two-dimensional general rate model for chromatographic columns of cylindrical geometry.

    Science.gov (United States)

    Qamar, Shamsul; Uche, David U; Khan, Farman U; Seidel-Morgenstern, Andreas

    2017-05-05

    This work is concerned with the analytical solutions and moment analysis of a linear two-dimensional general rate model (2D-GRM) describing the transport of a solute through a chromatographic column of cylindrical geometry. Analytical solutions are derived through successive implementation of finite Hankel and Laplace transformations for two different sets of boundary conditions. The process is further analyzed by deriving analytical temporal moments from the Laplace domain solutions. Radial gradients are typically neglected in liquid chromatography studies which are particularly important in the case of non-perfect injections. Several test problems of single-solute transport are considered. The derived analytical results are validated against the numerical solutions of a high resolution finite volume scheme. The derived analytical results can play an important role in further development of liquid chromatography. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Normal Mode Analysis to a Poroelastic Half-Space Problem under Generalized Thermoelasticity

    Directory of Open Access Journals (Sweden)

    Chunbao Xiong

    Full Text Available Abstract The thermo-hydro-mechanical problems associated with a poroelastic half-space soil medium with variable properties under generalized thermoelasticity theory were investigated in this study. By remaining faithful to Biot’s theory of dynamic poroelasticity, we idealized the foundation material as a uniform, fully saturated, poroelastic half-space medium. We first subjected this medium to time harmonic loads consisting of normal or thermal loads, then investigated the differences between the coupled thermohydro-mechanical dynamic models and the thermo-elastic dynamic models. We used normal mode analysis to solve the resulting non-dimensional coupled equations, then investigated the effects that non-dimensional vertical displacement, excess pore water pressure, vertical stress, and temperature distribution exerted on the poroelastic half-space medium and represented them graphically.

  2. A fully general and adaptive inverse analysis method for cementitious materials

    DEFF Research Database (Denmark)

    Jepsen, Michael S.; Damkilde, Lars; Lövgren, Ingemar

    2016-01-01

    are applied when modeling the fracture mechanisms in cementitious materials, but the vast development of pseudo-strain hardening, fiber reinforced cementitious materials require inverse methods, capable of treating multi-linear σ - w functions. The proposed method is fully general in the sense that it relies...... on least square fitting between test data obtained from various kinds of test setup, three-point bending or wedge splitting test, and simulated data obtained by either FEA or analytical models. In the current paper adaptive inverse analysis is conducted on test data obtained from three-point bending...... of notched specimens and simulated data from a nonlinear hinge model. The paper shows that the results obtained by means of the proposed method is independent on the initial shape of the σ - w function and the initial guess of the tensile strength. The method provides very accurate fits, and the increased...

  3. Confirmatory factor analysis of the generalized self-efficacy scale in Brazil and Portugal.

    Science.gov (United States)

    Leme, Vanessa B R; Coimbra, Susana; Gato, Jorge; Fontaine, Anne Marie; Del Prette, Zilda A P

    2013-01-01

    This study aims to evaluate the construct validity, internal consistency and cross-cultural invariance of the Generalized Self-Efficacy Scale-Portuguese version (GSE) in a Brazilian and Portuguese sample. The GSE is composed of 10 items, designed to parsimoniously and comprehensively assess self-efficacy beliefs to deal with a wide range of stress-inducing situations. The construct validity (factorial, convergent and discriminant) and internal consistency of the instrument were established within a sample of 304 Portuguese adolescents (study 1) and a sample of 477 Brazilian adolescents (study 2). Then, the invariance of the GSE was tested in a sample of Brazilian adolescents (study 3), using Multigroup Confirmatory Factor Analysis (MGCFA). In the first two studies, the construct validity of the GSE was demonstrated in its three components and the reliability of the scales was confirmed based on satisfactory levels of internal consistency. In the third study, the cross-cultural invariance of the instrument was established. This work adds to previous research on generalized self-efficacy instruments, with good psychometric qualities. Moreover, comparisons can now be made with confidence using this instrument among adolescent samples from Portugal and Brazil.

  4. Exploring the Utility of Logistic Mixed Modeling Approaches to Simultaneously Investigate Item and Testlet DIF on Testlet-based Data.

    Science.gov (United States)

    Fukuhara, Hirotaka; Paek, Insu

    2016-01-01

    This study explored the utility of logistic mixed models for the analysis of differential item functioning when item response data were testlet-based. Decomposition of differential item functioning (DIF) into item level and testlet level for the testlet-based data was introduced to separate possible sources of DIF: (1) an item, (2) a testlet, and (3) both the item and the testlet. Simulation study was conducted to investigate the performance of several logistic mixed models as well as the Mantel-Haenszel method under the conditions, in which the item-related DIF and testlet-related DIF were present simultaneously. The results revealed that a new DIF model based on a logistic mixed model with random item effects and item covariates could capture the item-related DIF and testlet-related DIF well under certain conditions.

  5. Perioperative factors predicting poor outcome in elderly patients following emergency general surgery: a multivariate regression analysis

    Science.gov (United States)

    Lees, Mackenzie C.; Merani, Shaheed; Tauh, Keerit; Khadaroo, Rachel G.

    2015-01-01

    Background Older adults (≥ 65 yr) are the fastest growing population and are presenting in increasing numbers for acute surgical care. Emergency surgery is frequently life threatening for older patients. Our objective was to identify predictors of mortality and poor outcome among elderly patients undergoing emergency general surgery. Methods We conducted a retrospective cohort study of patients aged 65–80 years undergoing emergency general surgery between 2009 and 2010 at a tertiary care centre. Demographics, comorbidities, in-hospital complications, mortality and disposition characteristics of patients were collected. Logistic regression analysis was used to identify covariate-adjusted predictors of in-hospital mortality and discharge of patients home. Results Our analysis included 257 patients with a mean age of 72 years; 52% were men. In-hospital mortality was 12%. Mortality was associated with patients who had higher American Society of Anesthesiologists (ASA) class (odds ratio [OR] 3.85, 95% confidence interval [CI] 1.43–10.33, p = 0.008) and in-hospital complications (OR 1.93, 95% CI 1.32–2.83, p = 0.001). Nearly two-thirds of patients discharged home were younger (OR 0.92, 95% CI 0.85–0.99, p = 0.036), had lower ASA class (OR 0.45, 95% CI 0.27–0.74, p = 0.002) and fewer in-hospital complications (OR 0.69, 95% CI 0.53–0.90, p = 0.007). Conclusion American Society of Anesthesiologists class and in-hospital complications are perioperative predictors of mortality and disposition in the older surgical population. Understanding the predictors of poor outcome and the importance of preventing in-hospital complications in older patients will have important clinical utility in terms of preoperative counselling, improving health care and discharging patients home. PMID:26204143

  6. A bibliometric analysis of Australian general practice publications from 1980 to 2007 using PubMed.

    Science.gov (United States)

    Mendis, Kumara; Kidd, Michael R; Schattner, Peter; Canalese, Joseph

    2010-01-01

    We analysed Australian general practice (GP) publications in PubMed from 1980 to 2007 to determine journals, authors, publication types, national health priority areas (NHPA) and compared the results with those from three specialties (public health, cardiology and medical informatics) and two countries (the UK and New Zealand). Australian GP publications were downloaded in MEDLINE format using PubMed queries and were written to a Microsoft Access database using a software application. Search Query Language and online PubMed queries were used for further analysis. There were 4777 publications from 1980 to 2007. Australian Family Physician (38.1%) and the Medical Journal of Australia (17.6%) contributed 55.7% of publications. Reviews (12.7%), letters (6.6%), clinical trials (6.5%) and systematic reviews (5%) were the main PubMed publication types. Thirty five percent of publications addressed National Health Priority Areas with material on mental health (13.7%), neoplasms (6.5%) and cardiovascular conditions (5.9%). The comparable numbers of publications for the three specialties were: public health - 80 911, cardiology - 15 130 and medical informatics - 3338; total country GP comparisons were: UK - 14 658 and New Zealand - 1111. Australian GP publications have shown an impressive growth from 1980 to 2007 with a 15-fold increase. This increase may be due in part to the actions of the Australian government over the past decade to financially support research in primary care, as well as the maturing of academic general practice. This analysis can assist governments, researchers, policy makers and others to target resources so that further developments can be encouraged, supported and monitored.

  7. A Rasch and confirmatory factor analysis of the General Health Questionnaire (GHQ) - 12

    Science.gov (United States)

    2010-01-01

    Background The General Health Questionnaire (GHQ) - 12 was designed as a short questionnaire to assess psychiatric morbidity. Despite the fact that studies have suggested a number of competing multidimensional factor structures, it continues to be largely used as a unidimensional instrument. This may have an impact on the identification of psychiatric morbidity in target populations. The aim of this study was to explore the dimensionality of the GHQ-12 and to evaluate a number of alternative models for the instrument. Methods The data were drawn from a large heterogeneous sample of cancer patients. The Partial Credit Model (Rasch) was applied to the 12-item GHQ. Item misfit (infit mean square ≥ 1.3) was identified, misfitting items removed and unidimensionality and differential item functioning (age, gender, and treatment aims) were assessed. The factor structures of the various alternative models proposed in the literature were explored and optimum model fit evaluated using Confirmatory Factor Analysis. Results The Rasch analysis of the 12-item GHQ identified six misfitting items. Removal of these items produced a six-item instrument which was not unidimensional. The Rasch analysis of an 8-item GHQ demonstrated two unidimensional structures corresponding to Anxiety/Depression and Social Dysfunction. No significant differential item functioning was observed by age, gender and treatment aims for the six- and eight-item GHQ. Two models competed for best fit from the confirmatory factor analysis, namely the GHQ-8 and Hankin's (2008) unidimensional model, however, the GHQ-8 produced the best overall fit statistics. Conclusions The results are consistent with the evidence that the GHQ-12 is a multi-dimensional instrument. Use of the summated scores for the GHQ-12 could potentially lead to an incorrect assessment of patients' psychiatric morbidity. Further evaluation of the GHQ-12 with different target populations is warranted. PMID:20433690

  8. A Rasch and confirmatory factor analysis of the general health questionnaire (GHQ)--12.

    Science.gov (United States)

    Smith, Adam B; Fallowfield, Lesley J; Stark, Dan P; Velikova, Galina; Jenkins, Valerie

    2010-04-30

    The General Health Questionnaire (GHQ) - 12 was designed as a short questionnaire to assess psychiatric morbidity. Despite the fact that studies have suggested a number of competing multidimensional factor structures, it continues to be largely used as a unidimensional instrument. This may have an impact on the identification of psychiatric morbidity in target populations. The aim of this study was to explore the dimensionality of the GHQ-12 and to evaluate a number of alternative models for the instrument. The data were drawn from a large heterogeneous sample of cancer patients. The Partial Credit Model (Rasch) was applied to the 12-item GHQ. Item misfit (infit mean square >or= 1.3) was identified, misfitting items removed and unidimensionality and differential item functioning (age, gender, and treatment aims) were assessed. The factor structures of the various alternative models proposed in the literature were explored and optimum model fit evaluated using Confirmatory Factor Analysis. The Rasch analysis of the 12-item GHQ identified six misfitting items. Removal of these items produced a six-item instrument which was not unidimensional. The Rasch analysis of an 8-item GHQ demonstrated two unidimensional structures corresponding to Anxiety/Depression and Social Dysfunction. No significant differential item functioning was observed by age, gender and treatment aims for the six- and eight-item GHQ. Two models competed for best fit from the confirmatory factor analysis, namely the GHQ-8 and Hankin's (2008) unidimensional model, however, the GHQ-8 produced the best overall fit statistics. The results are consistent with the evidence that the GHQ-12 is a multi-dimensional instrument. Use of the summated scores for the GHQ-12 could potentially lead to an incorrect assessment of patients' psychiatric morbidity. Further evaluation of the GHQ-12 with different target populations is warranted.

  9. Impact of General Chemistry on Student Achievement and Progression to Subsequent Chemistry Courses: A Regression Discontinuity Analysis

    Science.gov (United States)

    Shultz, Ginger V.; Gottfried, Amy C.; Winschel, Grace A.

    2015-01-01

    General chemistry is a gateway course that impacts the STEM trajectory of tens of thousands of students each year, and its role in the introductory curriculum as well as its pedagogical design are the center of an ongoing debate. To investigate the role of general chemistry in the curriculum, we report the results of a posthoc analysis of 10 years…

  10. Approximate analysis of non-stationary loss queues and networks of loss queues with general service time distributions

    OpenAIRE

    Izady, N; Worthington, D J

    2011-01-01

    A Fixed Point Approximation (FPA) method has recently been suggested for non-stationary analysis of loss queues and networks of loss queues with Exponential service times. Deriving exact equations relating time-dependent mean numbers of busy servers to blocking probabilities, we generalize the FPA method to loss systems with general service time distributions. These equations are combined with associated formulae for stationary analysis of loss systems in steady state through a carried load t...

  11. A general DNA analysis program for the Hewlett-Packard Model 86/87 microcomputer.

    Science.gov (United States)

    Harley, E H

    1986-01-10

    A program is described to perform general DNA sequence analysis on the Hewlett-Packard Model 86/87 microcomputer operating on 128 K of RAM. The following analytical procedures can be performed: 1. display of the sequence, in whole or part, or its complement; 2. search for specified sequences e.g. restriction sites, and in the case of the latter give fragment sizes; 3. perform a comprehensive search for all known restriction enzyme sites; 4. map sites graphically; 5. perform editing functions; 6. base frequency analysis; 7. search for repeated sequences; 8. search for open reading frames or translate into the amino acid sequence and analyse for basic and acidic amino acids, hydrophobicity, and codon usage. Two sequences, or parts thereof, can be merged in various orientations to mimic recombination strategies, or can be compared for homologies. The program is written in HP BASIC and is designed principally as a tool for the laboratory investigator manipulating a defined set of vectors and recombinant DNA constructs.

  12. Multiple Criteria Decision Making by Generalized Data Envelopment Analysis Introducing Aspiration Level Method

    International Nuclear Information System (INIS)

    Yun, Yeboon; Arakawa, Masao; Hiroshi, Ishikawa; Nakayama, Hirotaka

    2002-01-01

    It has been proved in problems with 2-objective functions that genetic algorithms (GAs) are well utilized for generating Pareto optimal solutions, and then decision making can be easily performed on the basis of visualized Pareto optimal solutions. However, GAs are difficult to visualize Pareto optimal solutions in cases in which the number of objective function is more than 4. Hence, it is trouble some to grasp the trade-off among many objective functions, and decision makers hesitate to choose a final solution from a number of Pareto optimal solutions. In order to solve these problems, we suggest an aspiration level approach to the method using the generalized data envelopment analysis and GAs. We show that the proposed method supports decision makers to choose their desirable solution from many Pareto optimal solutions. Furthermore, it will be seen that engineering design can be effectively done by the proposed method, which makes generation of several Pareto optimal solutions close to the aspiration level and trade-off analysis easily

  13. Bonding analysis of planar hypercoordinate atoms via the generalized BLW-LOL.

    Science.gov (United States)

    Bomble, Laetitia; Steinmann, Stephan N; Perez-Peralta, Nancy; Merino, Gabriel; Corminboeuf, Clemence

    2013-10-05

    The multicenter bonding pattern of the intriguing hexa-, hepta-, and octacoordinate boron wheel series (e.g., CB62-, CB7-, B82-, and SiB8 as well as the experimentally detected CB7- isomer) is revised using the block-localized wave function analyzed by the localized orbital locator (BLW-LOL). The more general implementation of BLW combined with the LOL scalar field is not restricted to the analysis of the out-of-plane π-system but can also provide an intuitive picture of the σ-radial delocalization and of the role of the central atom. The results confirm the presence of a π-ring current pattern similar to that of benzene. In addition, the LOLπ isosurfaces along with the maximum intensity in the ΔLOL profiles located above and below the ring suggest that the central atom plays a minor role in the π-delocalized bonding pattern. Finally, the analysis of the σ-framework in these boron wheels is in line with a moderated inner cyclic rather than disk-type delocalization. Copyright © 2013 Wiley Periodicals, Inc.

  14. Confirmatory factor analysis of the General Health Questionnaire (GHQ-12) in Spanish adolescents.

    Science.gov (United States)

    Padrón, Alicia; Galán, Iñaki; Durbán, María; Gandarillas, Ana; Rodríguez-Artalejo, Fernando

    2012-09-01

    To evaluate the factor structure of the 12-item General Health Questionnaire (GHQ-12) in a population of Spanish adolescents. Cross-sectional study among 4,146 individuals (mean age 16.3 years). The students completed a health questionnaire that included the GHQ-12. A confirmatory factor analysis (CFA) was conducted with four factor structure models. Three of the models were theory-driven: unidimensional, two-dimensional (positive and negative questions), model proposed by Graetz (anxiety and depression, social dysfunction, loss of confidence); and the fourth model was based on our exploratory factor analysis (EFA). The Cronbach's alpha for internal consistency was 0.82. A three-dimensional structure was identified in the EFA. The first factor included items 1, 2, 5, 6, 7, and 9 of the GHQ-12; the second, items 3, 10, and 11; and the third, items 4, 8, and 12. The three factors together explained 53.7% of the variance. The model with the best fit in the CFA was the three-dimensional model proposed by Graetz, followed by the three-dimensional model derived from the EFA. These two models had acceptable goodness-of-fit indices. In an adolescent population from Southern Europe, the GHQ-12 showed high internal consistency. The factor structure that best fitted the data was the Graetz three-dimensional model. However, the high correlations observed between factors suggest that the GHQ-12 should be used as a unidimensional scale, as currently done.

  15. A general procedure for estimating dynamic displacements using strain measurements and operational modal analysis

    Science.gov (United States)

    Skafte, Anders; Aenlle, Manuel L.; Brincker, Rune

    2016-02-01

    Measurement systems are being installed in more and more civil structures with the purpose of monitoring the general dynamic behavior of the structure. The instrumentation is typically done with accelerometers, where experimental frequencies and mode shapes can be identified using modal analysis and used in health monitoring algorithms. But the use of accelerometers is not suitable for all structures. Structures like wind turbine blades and wings on airplanes can be exposed to lightning, which can cause the measurement systems to fail. Structures like these are often equipped with fiber sensors measuring the in-plane deformation. This paper proposes a method in which the displacement mode shapes and responses can be predicted using only strain measurements. The method relies on the newly discovered principle of local correspondence, which states that each experimental mode can be expressed as a unique subset of finite element modes. In this paper the technique is further developed to predict the mode shapes in different states of the structure. Once an estimate of the modes is found, responses can be predicted using the superposition of the modal coordinates weighted by the mode shapes. The method is validated with experimental tests on a scaled model of a two-span bridge installed with strain gauges. Random load was applied to simulate a civil structure under operating condition, and strain mode shapes were identified using operational modal analysis.

  16. An examination of generalized anxiety disorder and dysthymic disorder by latent class analysis.

    Science.gov (United States)

    Rhebergen, D; van der Steenstraten, I M; Sunderland, M; de Graaf, R; Ten Have, M; Lamers, F; Penninx, B W J H; Andrews, G

    2014-06-01

    The nosological status of generalized anxiety disorder (GAD) versus dysthymic disorder (DD) has been questioned. The aim of this study was to examine qualitative differences within (co-morbid) GAD and DD symptomatology. Latent class analysis was applied to anxious and depressive symptomatology of respondents from three population-based studies (2007 Australian National Survey of Mental Health and Wellbeing; National Comorbidity Survey Replication; and Netherlands Mental Health Survey and Incidence Study-2; together known as the Triple study) and respondents from a multi-site naturalistic cohort [Netherlands Study of Depression and Anxiety (NESDA)]. Sociodemographics and clinical characteristics of each class were examined. A three-class (Triple study) and two-class (NESDA) model best fitted the data, reflecting mainly different levels of severity of symptoms. In the Triple study, no division into a predominantly GAD or DD co-morbidity subtype emerged. Likewise, in spite of the presence of pure GAD and DD cases in the NESDA sample, latent class analysis did not identify specific anxiety or depressive profiles in the NESDA study. Next, sociodemographics and clinical characteristics of each class were examined. Classes only differed in levels of severity. The absence of qualitative differences in anxious or depressive symptomatology in empirically derived classes questions the differentiation between GAD and DD.

  17. Interactive general-purpose function minimization for the analysis of neutron scattering data

    International Nuclear Information System (INIS)

    Abel, W.

    1981-12-01

    An on-line graphic display facility has been employed mainly for the peak analysis of time-of-flight spectra measured by inelastic scattering of thermal neutrons. But it is useful also for the analysis of spectra measured with triple axis spectrometers and of diffraction patterns. The spectral lines may be fitted by the following analytical shape functions: (i) a Gaussian, (ii) a Lorentzian, or (iii) a convolution of a Lorentzian with a Gaussian, plus a background continuum. Data reduction or correction may be invoked optionally. For more general applications in analysing of numerical data there is also the possibility to define the analytical shape functions by the user. Three different minimization methods are available which may be used alone or in combination. The parameters of the shape functions may be kept fixed or variable during the minimization steps. The width of variation may be restricted. Global correlation coefficients, parameter errors and the chi 2 are displayed to inform the user about the quality of the fit. A detailed description of the program operations is given. The programs are written in FORTRAN IV and use an IBM/2250-1 graphic display unit. (orig.) [de

  18. A general model for preload calculation and stiffness analysis for combined angular contact ball bearings

    Science.gov (United States)

    Zhang, Jinhua; Fang, Bin; Hong, Jun; Wan, Shaoke; Zhu, Yongsheng

    2017-12-01

    The combined angular contact ball bearings are widely used in automatic, aerospace and machine tools, but few researches on the combined angular contact ball bearings have been reported. It is shown that the preload and stiffness of combined bearings are mutual influenced rather than simply the superposition of multiple single bearing, therefore the characteristic calculation of combined bearings achieved by coupling the load and deformation analysis of a single bearing. In this paper, based on the Jones quasi-static model and stiffness analytical model, a new iterative algorithm and model are proposed for the calculation of combined bearings preload and stiffness, and the dynamic effects include centrifugal force and gyroscopic moment have to be considered. It is demonstrated that the new method has general applicability, the preload factors of combined bearings are calculated according to the different design preloads, and the static and dynamic stiffness for various arrangements of combined bearings are comparatively studied and analyzed, and the influences of the design preload magnitude, axial load and rotating speed are discussed in detail. Besides, the change rule of dynamic contact angles of combined bearings with respect to the rotating speed is also discussed. The results show that bearing arrangement modes, rotating speed and design preload magnitude have a significant influence on the preload and stiffness of combined bearings. The proposed formulation provides a useful tool in dynamic analysis of the complex bearing-rotor system.

  19. Patients with special needs within treatment under general anesthesia - meta-analysis.

    Science.gov (United States)

    Stanková, M; Buček, A; Dostálová, T; Ginzelová, K; Pacáková, Z; Seydlová, M

    2011-01-01

    The study evaluates results obtained from the documentation of patients with special needs, who have undergone treatment under general anesthesia at the pediatric dentistry department. DMFT (decayed, missing, filled teeth) was used for comparison. A sample of 1,836 children from our dental clinic was evaluated. The sample was divided into two groups - special patient and disabled patient populations. A group of 5 years old children was chosen on the bases of WHO guidelines for the setting of the oral health status. A descriptive statistical analysis of the mean standard deviation was conducted with a focus on three factors: sex, age and year. A questionnaire was prepared to compare the oral health habits in the families of the patients. A literary review was conducted to compare the results with other studies from various countries. The meta-analysis using the software MedCalc was done. The DMFT of the patient was counted (disabled DMFT 11.05 - SD 4.82, special patient population 8.8 - SD 3.7) and the descriptive statistics mean standard deviation was calculated. The significant difference between the DMFT of disabled patient and special patient population was exerted (pspecial needs children is worse than in other countries.

  20. Revisiting of Multiscale Static Analysis of Notched Laminates Using the Generalized Method of Cells

    Science.gov (United States)

    Naghipour Ghezeljeh, Paria; Arnold, Steven M.; Pineda, Evan J.

    2016-01-01

    Composite material systems generally exhibit a range of behavior on different length scales (from constituent level to macro); therefore, a multiscale framework is beneficial for the design and engineering of these material systems. The complex nature of the observed composite failure during experiments suggests the need for a three-dimensional (3D) multiscale model to attain a reliable prediction. However, the size of a multiscale three-dimensional finite element model can become prohibitively large and computationally costly. Two-dimensional (2D) models are preferred due to computational efficiency, especially if many different configurations have to be analyzed for an in-depth damage tolerance and durability design study. In this study, various 2D and 3D multiscale analyses will be employed to conduct a detailed investigation into the tensile failure of a given multidirectional, notched carbon fiber reinforced polymer laminate. Threedimensional finite element analysis is typically considered more accurate than a 2D finite element model, as compared with experiments. Nevertheless, in the absence of adequate mesh refinement, large differences may be observed between a 2D and 3D analysis, especially for a shear-dominated layup. This observed difference has not been widely addressed in previous literature and is the main focus of this paper.

  1. Special Analysis: 2004 General Revision of Slit and Engineered Trench Limits

    Energy Technology Data Exchange (ETDEWEB)

    COLLARD, LEONARDB.

    2004-06-14

    This Special Analysis revises the Slit Trench and Engineered Trench inventory limits. Changes have been made in the methods of analyses and in the implementation of those methods. General changes applicable to multiple pathways/scenarios are discussed in this section, while changes specific to individual pathways/scenarios are discussed in their applicable sections. This report provides limits for each nuclide for each pathway/scenario in a single table to help implement the approach introduced in the ''timed sum-of-fractions'' report. The pathways/scenarios include the following: (1) Groundwater; (2) Inadvertent Intruder; (3) Air; (4) Radon. In the timed sum-of-fractions report, the time intervals were selected to be 0-100 years, 100-1000 years, and 1000-10,000 years. The time intervals for this report were refined to 0-12 years, 12-100 years, and 100-1000 years to account for the separation of the tritium groundwater peak from those of other radionuclides. This report includes nuclides not previously included in the process analysis. Some of these nuclides are included because they have been disposed in Slit or Engineered Trenches and the latest screening analysis indicates that they survived the screening process. Other nuclides are only included because they survived the screening process and they have been disposed in other disposal units. Inventory limits for Slit Trenches and Engineered Trenches were recalculated while imposing a multitude of changes. The most important changes both tended to increase limits, such as changing the time of compliance from 10,000 years to 1000 years and tended to decrease limits, such as modifying the aquifer source node selection. The net effect for the groundwater pathway reduced some limits for nuclides that dominate the sum-of-fractions.

  2. Mobile and traditional cognitive behavioral therapy programs for generalized anxiety disorder: A cost-effectiveness analysis.

    Science.gov (United States)

    Kumar, Shefali; Jones Bell, Megan; Juusola, Jessie L

    2018-01-01

    Generalized anxiety disorder (GAD) is a debilitating mental health illness that affects approximately 3.1% of U.S. adults and can be treated with cognitive behavioral therapy (CBT). With the emergence of digital health technologies, mobile CBT may be a cost-effective way to deliver care. We developed an analysis framework to quantify the cost-effectiveness of internet-based CBT for individuals with GAD. As a case study, we examined the potential value of a new mobile-delivered CBT program for GAD. We developed a Markov model of GAD health states combined with a detailed economic analysis for a cohort of adults with GAD in the U.S. In our case study, we used pilot program efficacy data to evaluate a mobile CBT program as either prevention or treatment only and compared the strategies to traditional CBT and no CBT. Traditional CBT efficacy was estimated from clinical trial results. We calculated discounted incremental costs and quality-adjusted life-years (QALYs) over the cohort lifetime. In the base case, for a cohort of 100,000 persons with GAD, we found that mobile CBT is cost-saving. It leads to a gain of 34,108 QALYs and 81,492 QALYs and a cost reduction of $2.23 billion and $4.54 billion when compared to traditional CBT and no CBT respectively. Results were insensitive to most model inputs and mobile CBT remained cost-saving in almost all scenarios. The case study was conducted for illustrative purposes and used mobile CBT efficacy data from a small pilot program; the analysis should be re-conducted once robust efficacy data is available. The model was limited in its ability to measure the effectiveness of CBT in combination with pharmacotherapy. Mobile CBT may lead to improved health outcomes at lower costs than traditional CBT or no intervention and may be effective as either prevention or treatment.

  3. Node-Splitting Generalized Linear Mixed Models for Evaluation of Inconsistency in Network Meta-Analysis.

    Science.gov (United States)

    Yu-Kang, Tu

    2016-12-01

    Network meta-analysis for multiple treatment comparisons has been a major development in evidence synthesis methodology. The validity of a network meta-analysis, however, can be threatened by inconsistency in evidence within the network. One particular issue of inconsistency is how to directly evaluate the inconsistency between direct and indirect evidence with regard to the effects difference between two treatments. A Bayesian node-splitting model was first proposed and a similar frequentist side-splitting model has been put forward recently. Yet, assigning the inconsistency parameter to one or the other of the two treatments or splitting the parameter symmetrically between the two treatments can yield different results when multi-arm trials are involved in the evaluation. We aimed to show that a side-splitting model can be viewed as a special case of design-by-treatment interaction model, and different parameterizations correspond to different design-by-treatment interactions. We demonstrated how to evaluate the side-splitting model using the arm-based generalized linear mixed model, and an example data set was used to compare results from the arm-based models with those from the contrast-based models. The three parameterizations of side-splitting make slightly different assumptions: the symmetrical method assumes that both treatments in a treatment contrast contribute to inconsistency between direct and indirect evidence, whereas the other two parameterizations assume that only one of the two treatments contributes to this inconsistency. With this understanding in mind, meta-analysts can then make a choice about how to implement the side-splitting method for their analysis. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  4. A Flexible Nonlinear Modelling Framework for Nonstationary Generalized Extreme Value Analysis in Hydrology and Climatology

    Science.gov (United States)

    Cannon, A. J.

    2009-12-01

    Parameters in a Generalized Extreme Value (GEV) distribution are specified as a function of covariates using a conditional density network (CDN), which is a probabilistic extension of the multilayer perceptron neural network. If the covariate is time, or is dependent on time, then the GEV-CDN model can be used to perform nonlinear, nonstationary GEV analysis of hydrological or climatological time series. Due to the flexibility of the neural network architecture, the model is capable of representing a wide range of nonstationary relationships. Model parameters are estimated by generalized maximum likelihood, an approach that is tailored to the estimation of GEV parameters from geophysical time series. Model complexity is identified using the Bayesian information criterion and the Akaike information criterion with small sample size correction. Monte Carlo simulations are used to validate GEV-CDN performance on four simple synthetic problems. The model is then demonstrated on precipitation data from southern California, a series that exhibits nonstationarity due to interannual/interdecadal climatic variability. A hierarchy of models can be defined by adjusting three aspects of the GEV-CDN model architecture: (i) by specifying either a linear or a nonlinear hidden-layer activation function; (ii) by adjusting the number of hidden-layer nodes; or (iii) by disconnecting weights leading to output-layer nodes. To illustrate, five GEV-CDN models are shown here in order of increasing complexity for the case of a single covariate, which, in this case, is assumed to be time. The shape parameter is assumed to be constant in all models, although this is not a requirement of the GEV-CDN framework.

  5. General and specialized brain correlates for analogical reasoning: A meta-analysis of functional imaging studies.

    Science.gov (United States)

    Hobeika, Lucie; Diard-Detoeuf, Capucine; Garcin, Béatrice; Levy, Richard; Volle, Emmanuelle

    2016-05-01

    Reasoning by analogy allows us to link distinct domains of knowledge and to transfer solutions from one domain to another. Analogical reasoning has been studied using various tasks that have generally required the consideration of the relationships between objects and their integration to infer an analogy schema. However, these tasks varied in terms of the level and the nature of the relationships to consider (e.g., semantic, visuospatial). The aim of this study was to identify the cerebral network involved in analogical reasoning and its specialization based on the domains of information and task specificity. We conducted a coordinate-based meta-analysis of 27 experiments that used analogical reasoning tasks. The left rostrolateral prefrontal cortex was one of the regions most consistently activated across the studies. A comparison between semantic and visuospatial analogy tasks showed both domain-oriented regions in the inferior and middle frontal gyri and a domain-general region, the left rostrolateral prefrontal cortex, which was specialized for analogy tasks. A comparison of visuospatial analogy to matrix problem tasks revealed that these two relational reasoning tasks engage, at least in part, distinct right and left cerebral networks, particularly separate areas within the left rostrolateral prefrontal cortex. These findings highlight several cognitive and cerebral differences between relational reasoning tasks that can allow us to make predictions about the respective roles of distinct brain regions or networks. These results also provide new, testable anatomical hypotheses about reasoning disorders that are induced by brain damage. Hum Brain Mapp 37:1953-1969, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  6. Surface Lander Missions to Mars: Support via Analysis of the NASA Ames Mars General Circulation Model

    Science.gov (United States)

    Murphy, James R.; Bridger, Alison F.C.; Haberle, Robert M.

    1997-01-01

    We have characterized the near-surface martian wind environment as calculated with a set of numerical simulations carried out with the NASA Ames Mars General Circulation Model (Mars GCM). These wind environments are intended to offer future spacecraft missions to the martian surface a data base from which to choose those locations which meet the mission's criteria for minimal near surface winds to enable a successful landing. We also became involved in the development and testing of the wind sensor which is currently onboard the Mars-bound Pathfinder lander. We began this effort with a comparison of Mars GCM produced winds with those measured by the Viking landers during their descent through the martian atmosphere and their surface wind measurements during the 3+ martian year lifetime of the mission. Unexpected technical difficulties in implementing the sophisticated Planetary Boundary Layer (PBL) scheme of Haberle et al. (1993) within the Mars GCM precluded our carrying out this investigation with the desired improvement to the model's treatment of the PBL. Thus, our results from this effort are not as conclusive as we had anticipated. As it turns out, similar difficulties have been experienced by other Mars modelling groups in attempting to implement very similar PBL routines into their GCMs (Mars General Circulation Model Intercomparison Workshop, held at Oxford University, United Kingdom, July 22-24, 1996; organized by J. Murphy, J. Hollingsworth, M. Joshi). These problems, which arise due to the nature of the time stepping in each of the models, are near to being resolved at the present. The model discussions which follow herein are based upon results using the existing, less sophisticated PBL routine. We fully anticipate implementing the tools we have developed in the present effort to investigate GCM results with the new PBL scheme implemented, and thereafter producing the technical document detailing results from the analysis tools developed during this

  7. Chemoinformatic Analysis of GRAS (Generally Recognized as Safe) Flavor Chemicals and Natural Products

    Science.gov (United States)

    Medina-Franco, José L.; Martínez-Mayorga, Karina; Peppard, Terry L.; Del Rio, Alberto

    2012-01-01

    Food materials designated as “Generally Recognized as Safe” (GRAS) are attracting the attention of researchers in their attempts to systematically identify compounds with putative health-related benefits. In particular, there is currently a great deal of interest in exploring possible secondary benefits of flavor ingredients, such as those relating to health and wellness. One step in this direction is the comprehensive characterization of the chemical structures contained in databases of flavoring substances. Herein, we report a comprehensive analysis of the recently updated FEMA GRAS list of flavoring substances (discrete chemical entities only). Databases of natural products, approved drugs and a large set of commercial molecules were used as references. Remarkably, natural products continue to be an important source of bioactive compounds for drug discovery and nutraceutical purposes. The comparison of five collections of compounds of interest was performed using molecular properties, rings, atom counts and structural fingerprints. It was found that the molecular size of the GRAS flavoring substances is, in general, smaller cf. members of the other databases analyzed. The lipophilicity profile of the GRAS database, a key property to predict human bioavailability, is similar to approved drugs. Several GRAS chemicals overlap to a broad region of the property space occupied by drugs. The GRAS list analyzed in this work has high structural diversity, comparable to approved drugs, natural products and libraries of screening compounds. This study represents one step towards the use of the distinctive features of the flavoring chemicals contained in the GRAS list and natural products to systematically search for compounds with potential health-related benefits. PMID:23226386

  8. Composite and Cascaded Generalized-K Fading Channel Modeling and Their Diversity and Performance Analysis

    KAUST Repository

    Ansari, Imran Shafique

    2010-12-01

    The introduction of new schemes that are based on the communication among nodes has motivated the use of composite fading models due to the fact that the nodes experience different multipath fading and shadowing statistics, which subsequently determines the required statistics for the performance analysis of different transceivers. The end-to-end signal-to-noise-ratio (SNR) statistics plays an essential role in the determination of the performance of cascaded digital communication systems. In this thesis, a closed-form expression for the probability density function (PDF) of the end-end SNR for independent but not necessarily identically distributed (i.n.i.d.) cascaded generalized-K (GK) composite fading channels is derived. The developed PDF expression in terms of the Meijer-G function allows the derivation of subsequent performance metrics, applicable to different modulation schemes, including outage probability, bit error rate for coherent as well as non-coherent systems, and average channel capacity that provides insights into the performance of a digital communication system operating in N cascaded GK composite fading environment. Another line of research that was motivated by the introduction of composite fading channels is the error performance. Error performance is one of the main performance measures and derivation of its closed-form expression has proved to be quite involved for certain systems. Hence, in this thesis, a unified closed-form expression, applicable to different binary modulation schemes, for the bit error rate of dual-branch selection diversity based systems undergoing i.n.i.d. GK fading is derived in terms of the extended generalized bivariate Meijer G-function.

  9. Latent class analysis of comorbidity patterns among women with generalized and localized vulvodynia: preliminary findings

    Directory of Open Access Journals (Sweden)

    Nguyen RHN

    2013-04-01

    Full Text Available Ruby HN Nguyen,1 Christin Veasley,2 Derek Smolenski1,3 1Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN, 2National Vulvodynia Association, Silver Spring, MD, 3National Center for Telehealth and Technology, Defense Centers of Excellence, Department of Defense, Tacoma, WA, USA Background: The pattern and extent of clustering of comorbid pain conditions with vulvodynia is largely unknown. However, elucidating such patterns may improve our understanding of the underlying mechanisms involved in these common causes of chronic pain. We sought to describe the pattern of comorbid pain clustering in a population-based sample of women with diagnosed vulvodynia. Methods: A total of 1457 women with diagnosed vulvodynia self-reported their type of vulvar pain as localized, generalized, or both. Respondents were also surveyed about the presence of comorbid pain conditions, including temporomandibular joint and muscle disorders, interstitial cystitis, fibromyalgia, chronic fatigue syndrome, irritable bowel syndrome, endometriosis, and chronic headache. Age-adjusted latent class analysis modeled extant patterns of comorbidity by vulvar pain type, and a multigroup model was used to test for the equality of comorbidity patterns using a comparison of prevalence. A two-class model (no/single comorbidity versus multiple comorbidities had the best fit in individual and multigroup models. Results: For the no/single comorbidity class, the posterior probability prevalence of item endorsement ranged from 0.9% to 24.4%, indicating a low probability of presence. Conversely, the multiple comorbidity class showed that at least two comorbid conditions were likely to be endorsed by at least 50% of women in that class, and irritable bowel syndrome and fibromyalgia were the most common comorbidities regardless of type of vulvar pain. Prevalence of the multiple comorbidity class differed by type of vulvar pain: both

  10. Human Error and General Aviation Accidents: A Comprehensive, Fine-Grained Analysis Using HFACS

    National Research Council Canada - National Science Library

    Wiegmann, Douglas; Faaborg, Troy; Boquet, Albert; Detwiler, Cristy; Holcomb, Kali; Shappell, Scott

    2005-01-01

    ... of both commercial and general aviation (GA) accidents. These analyses have helped to identify general trends in the types of human factors issues and aircrew errors that have contributed to civil aviation accidents...

  11. Impact of prenatal diagnosis on survival of newborns with four congenital heart defects: a prospective, population-based cohort study in France (the EPICARD Study)

    Science.gov (United States)

    Khoshnood, Babak; Lelong, Nathalie; Houyel, Lucile; Bonnet, Damien; Ballon, Morgane; Jouannic, Jean-Marie; Goffinet, François

    2017-01-01

    Objectives (1) Assess the population-level probability of prenatal diagnosis and termination of pregnancy for fetal anomaly for four major congenital heart defects; (2) Examine, using population-based data, the relation between timing of (prenatal vs postnatal) diagnosis and risk of infant (ie, < 1 year) mortality for four major congenital heart defects (CHDs). Design Population-based cohort (the EPIdémiologie des CARDiopathies congénitales) study. Setting Greater Paris area (Paris and its surrounding suburbs). Patients Three hundred and fifty-four cases of four major CHDs, including functionally univentricular heart (FUH, N=132), d-transposition of great arteries (d-TGA, N=85), tetralogy of Fallot (TOF, N=60) and coarctation of aorta (CoA, N=77). Statistical analysis included the Mantel-Haenszel method and a test of homogeneity of risk ratios. Results Approximately 95% of FUH, more than two-thirds of d-TGA and TOF, and 40% of CoA were prenatally diagnosed. Overall, we did not find any statistically significant association between timing of (prenatal vs postnatal) diagnosis of CHD and risk of infant mortality (Mantel-Haenszel risk ratio 1.1, 95% CI 0.5 – 2.7); and the differences between the risk ratios of the association between prenatal diagnosis and infant mortality across the four CHDs was not statistically significant. Conclusion These results imply that at least in the settings where specialised services are readily available, survival may no longer be the most relevant outcome, or the best criterion, for evaluating the impact of prenatal diagnosis on the outcome of CHD. The beneficial effects of prenatal diagnosis may be better sought by looking at more ’subtle' or long-term neurodevelopmental outcomes. PMID:29122798

  12. Work-related health problems among resident immigrant workers in Italy and Spain

    Directory of Open Access Journals (Sweden)

    Aldo Rosano

    2012-09-01

    Full Text Available

    Background: in both Spain and Italy the number of immigrants has strongly increased in the last 20 years, currently representing more than the 10% of workforce in each country. The segregation of immigrants into unskilled or risky jobs brings negative consequences for their health. The objective of this study is to compare prevalence of work-related health problems between immigrants and native workers in Italy and Spain.

    Methods: data come from the Italian Labour Force Survey (n=65 779 and Spanish Working Conditions Survey (n=11 019, both conducted in 2007. We analyzed merged datasets to evaluate whether interviewees, both natives and migrants, judge their health being affected by their work conditions and, if so, which specific diseases. For migrants, we considered those coming from countries with a value of the Human Development Index lower than 0.85. Logistic regression models were used, including gender, age, and education as adjusting factors.

    Results: migrants reported skin diseases (Mantel-Haenszel pooled OR=1.49; 95%CI: 0.59-3.74 and musculoskeletal problems among those employed in agricultural sector (Mantel-Haenszel pooled OR=1.16; 95%CI: 0.69-1.96 more frequently than natives; country-specific analysis showed higher risks of musculoskeletal problems among migrants compared to the non-migrant population in Italy (OR=1.17; 95% CI: 0.48-1.59 and of respiratory problems in Spain (OR=2.02; 95%CI: 1.02-4.0. In both countries the risk of psychological stress was predominant among national workers.

    Conclusions: this collaborative study allows to strength the evidence concerning the health of migrant workers in Southern European countries.

  13. On the stability analysis of a general discrete-time population model involving predation and Allee effects

    International Nuclear Information System (INIS)

    Merdan, H.; Duman, O.

    2009-01-01

    This paper presents the stability analysis of equilibrium points of a general discrete-time population dynamics involving predation with and without Allee effects which occur at low population density. The mathematical analysis and numerical simulations show that the Allee effect has a stabilizing role on the local stability of the positive equilibrium points of this model.

  14. [Schizotypal Personality Questionnaire-Brief - Likert format: Factor structure analysis in general population in France].

    Science.gov (United States)

    Ferchiou, A; Todorov, L; Lajnef, M; Baudin, G; Pignon, B; Richard, J-R; Leboyer, M; Szöke, A; Schürhoff, F

    2017-12-01

    The main objective of the study was to explore the factorial structure of the French version of the Schizotypal Personality Questionnaire-Brief (SPQ-B) in a Likert format, in a representative sample of the general population. In addition, differences in the dimensional scores of schizotypy according to gender and age were analyzed. As the study in the general population of schizotypal traits and its determinants has been recently proposed as a way toward the understanding of aetiology and pathophysiology of schizophrenia, consistent self-report tools are crucial to measure psychometric schizotypy. A shorter version of the widely used Schizotypal Personality Questionnaire (SPQ-Brief) has been extensively investigated in different countries, particularly in samples of students or clinical adolescents, and more recently, a few studies used a Likert-type scale format which allows partial endorsement of items and reduces the risk of defensive answers. A sample of 233 subjects representative of the adult population from an urban area near Paris (Créteil) was recruited using the "itinerary method". They completed the French version of the SPQ-B with a 5-point Likert-type response format (1=completely disagree; 5=completely agree). We examined the dimensional structure of the French version of the SPQ-B with a Principal Components Analysis (PCA) followed by a promax rotation. Factor selection was based on Eigenvalues over 1.0 (Kaiser's criterion), Cattell's Scree-plot test, and interpretability of the factors. Items with loadings greater than 0.4 were retained for each dimension. The internal consistency estimate of the dimensions was calculated with Cronbach's α. In order to study the influence of age and gender, we carried out a simple linear regression with the subscales as dependent variables. Our sample was composed of 131 women (mean age=52.5±18.2 years) and 102 men (mean age=53±18.1 years). SPQ-B Likert total scores ranged from 22 to 84 points (mean=43.6

  15. Effects of eHealth Literacy on General Practitioner Consultations: A Mediation Analysis.

    Science.gov (United States)

    Schulz, Peter Johannes; Fitzpatrick, Mary Anne; Hess, Alexandra; Sudbury-Riley, Lynn; Hartung, Uwe

    2017-05-16

    Most evidence (not all) points in the direction that individuals with a higher level of health literacy will less frequently utilize the health care system than individuals with lower levels of health literacy. The underlying reasons of this effect are largely unclear, though people's ability to seek health information independently at the time of wide availability of such information on the Internet has been cited in this context. We propose and test two potential mediators of the negative effect of eHealth literacy on health care utilization: (1) health information seeking and (2) gain in empowerment by information seeking. Data were collected in New Zealand, the United Kingdom, and the United States using a Web-based survey administered by a company specialized on providing online panels. Combined, the three samples resulted in a total of 996 baby boomers born between 1946 and 1965 who had used the Internet to search for and share health information in the previous 6 months. Measured variables include eHealth literacy, Internet health information seeking, the self-perceived gain in empowerment by that information, and the number of consultations with one's general practitioner (GP). Path analysis was employed for data analysis. We found a bundle of indirect effect paths showing a positive relationship between health literacy and health care utilization: via health information seeking (Path 1), via gain in empowerment (Path 2), and via both (Path 3). In addition to the emergence of these indirect effects, the direct effect of health literacy on health care utilization disappeared. The indirect paths from health literacy via information seeking and empowerment to GP consultations can be interpreted as a dynamic process and an expression of the ability to find, process, and understand relevant information when that is necessary. ©Peter Johannes Schulz, Mary Anne Fitzpatrick, Alexandra Hess, Lynn Sudbury-Riley, Uwe Hartung. Originally published in the Journal of

  16. Application of generalized perturbation theory to sensitivity analysis in boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Vanessa S. [Universidade Federal Fluminense (EEIMVR/UFF-RJ), Volta Redonda, RJ (Brazil). Escola de Engenharia Industrial e Metalurgica. Programa de Pos-Graduacao em Modelagem Computacional em Ciencia e Tecnologia; Silva, Fernando C.; Silva, Ademir X., E-mail: fernando@con.ufrj.b, E-mail: ademir@con.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Alvarez, Gustavo B. [Universidade Federal Fluminense (EEIMVR/UFF-RJ), Volta Redonda, RJ (Brazil). Escola de Engenharia Industrial e Metalurgica. Dept. de Ciencias Exatas

    2011-07-01

    Boron neutron capture therapy - BNCT - is a binary cancer treatment used in brain tumors. The tumor is loaded with a boron compound and subsequently irradiated by thermal neutrons. The therapy is based on the {sup 10}B (n, {alpha}) {sup 7}Li nuclear reaction, which emits two types of high-energy particles, {alpha} particle and the {sup 7}Li nuclei. The total kinetic energy released in this nuclear reaction, when deposited in the tumor region, destroys the cancer cells. Since the success of the BNCT is linked to the different selectivity between the tumor and healthy tissue, it is necessary to carry out a sensitivity analysis to determinate the boron concentration. Computational simulations are very important in this context because they help in the treatment planning by calculating the lowest effective absorbed dose rate to reduce the damage to healthy tissue. The objective of this paper is to present a deterministic method based on generalized perturbation theory (GPT) to perform sensitivity analysis with respect to the {sup 10}B concentration and to estimate the absorbed dose rate by patients undergoing this therapy. The advantage of the method is a significant reduction in computational time required to perform these calculations. To simulate the neutron flux in all brain regions, the method relies on a two-dimensional neutron transport equation whose spatial, angular and energy variables are discretized by the diamond difference method, the discrete ordinate method and multigroup formulation, respectively. The results obtained through GPT are consistent with those obtained using other methods, demonstrating the efficacy of the proposed method. (author)

  17. An efficient General Transit Feed Specification (GTFS enabled algorithm for dynamic transit accessibility analysis.

    Directory of Open Access Journals (Sweden)

    S Kiavash Fayyaz S

    Full Text Available The social functions of urbanized areas are highly dependent on and supported by the convenient access to public transportation systems, particularly for the less privileged populations who have restrained auto ownership. To accurately evaluate the public transit accessibility, it is critical to capture the spatiotemporal variation of transit services. This can be achieved by measuring the shortest paths or minimum travel time between origin-destination (OD pairs at each time-of-day (e.g. every minute. In recent years, General Transit Feed Specification (GTFS data has been gaining popularity for between-station travel time estimation due to its interoperability in spatiotemporal analytics. Many software packages, such as ArcGIS, have developed toolbox to enable the travel time estimation with GTFS. They perform reasonably well in calculating travel time between OD pairs for a specific time-of-day (e.g. 8:00 AM, yet can become computational inefficient and unpractical with the increase of data dimensions (e.g. all times-of-day and large network. In this paper, we introduce a new algorithm that is computationally elegant and mathematically efficient to address this issue. An open-source toolbox written in C++ is developed to implement the algorithm. We implemented the algorithm on City of St. George's transit network to showcase the accessibility analysis enabled by the toolbox. The experimental evidence shows significant reduction on computational time. The proposed algorithm and toolbox presented is easily transferable to other transit networks to allow transit agencies and researchers perform high resolution transit performance analysis.

  18. An efficient General Transit Feed Specification (GTFS) enabled algorithm for dynamic transit accessibility analysis

    Science.gov (United States)

    Fayyaz S., S. Kiavash; Zhang, Guohui

    2017-01-01

    The social functions of urbanized areas are highly dependent on and supported by the convenient access to public transportation systems, particularly for the less privileged populations who have restrained auto ownership. To accurately evaluate the public transit accessibility, it is critical to capture the spatiotemporal variation of transit services. This can be achieved by measuring the shortest paths or minimum travel time between origin-destination (OD) pairs at each time-of-day (e.g. every minute). In recent years, General Transit Feed Specification (GTFS) data has been gaining popularity for between-station travel time estimation due to its interoperability in spatiotemporal analytics. Many software packages, such as ArcGIS, have developed toolbox to enable the travel time estimation with GTFS. They perform reasonably well in calculating travel time between OD pairs for a specific time-of-day (e.g. 8:00 AM), yet can become computational inefficient and unpractical with the increase of data dimensions (e.g. all times-of-day and large network). In this paper, we introduce a new algorithm that is computationally elegant and mathematically efficient to address this issue. An open-source toolbox written in C++ is developed to implement the algorithm. We implemented the algorithm on City of St. George’s transit network to showcase the accessibility analysis enabled by the toolbox. The experimental evidence shows significant reduction on computational time. The proposed algorithm and toolbox presented is easily transferable to other transit networks to allow transit agencies and researchers perform high resolution transit performance analysis. PMID:28981544

  19. Application of generalized perturbation theory to sensitivity analysis in boron neutron capture therapy

    International Nuclear Information System (INIS)

    Garcia, Vanessa S.; Silva, Fernando C.; Silva, Ademir X.; Alvarez, Gustavo B.

    2011-01-01

    Boron neutron capture therapy - BNCT - is a binary cancer treatment used in brain tumors. The tumor is loaded with a boron compound and subsequently irradiated by thermal neutrons. The therapy is based on the 10 B (n, α) 7 Li nuclear reaction, which emits two types of high-energy particles, α particle and the 7 Li nuclei. The total kinetic energy released in this nuclear reaction, when deposited in the tumor region, destroys the cancer cells. Since the success of the BNCT is linked to the different selectivity between the tumor and healthy tissue, it is necessary to carry out a sensitivity analysis to determinate the boron concentration. Computational simulations are very important in this context because they help in the treatment planning by calculating the lowest effective absorbed dose rate to reduce the damage to healthy tissue. The objective of this paper is to present a deterministic method based on generalized perturbation theory (GPT) to perform sensitivity analysis with respect to the 10 B concentration and to estimate the absorbed dose rate by patients undergoing this therapy. The advantage of the method is a significant reduction in computational time required to perform these calculations. To simulate the neutron flux in all brain regions, the method relies on a two-dimensional neutron transport equation whose spatial, angular and energy variables are discretized by the diamond difference method, the discrete ordinate method and multigroup formulation, respectively. The results obtained through GPT are consistent with those obtained using other methods, demonstrating the efficacy of the proposed method. (author)

  20. Analysis of facial morphology of UK and US general election candidates: Does the 'power face' exist?

    Science.gov (United States)

    Islam, Shofiq; Taylor, Christopher J; Hayter, Jonathan P

    2017-07-01

    To determine the frequency of recognised morphologic facial phenotypes among the UK and US election candidates and to assess whether there is a relationship between facial morphology and success in general elections. Facial morphology analysis of prime ministerial and presidential candidates in the UK and US elections was performed. Direct facial measurements were made from frontal images and facial morphological indices calculated for all candidates. Anthropometric facial phenotype was determined and comparisons made between the elected leaders and unelected runner-up candidates. Paired candidates who had different facial types were analysed as a subgroup, with the probabilities of electoral success calculated. Data were available for 45 subjects: 22 election winners and 23 unelected runner-ups. Our data showed some variation in facial morphology between the groups. The predominant facial phenotype in both groups was leptoprosopic (long and/or narrow face), accounting for 40% (n = 18). Mesoprosopic (average dimension) and euryprosopic (short and/or broad) facial type represented 31% (n = 14) and 18% (n = 8), respectively. A majority of the sample (n = 36) demonstrated a malar width to mandibular angle width ratio consistent with the modern 'power face' proportion. Subgroup analysis showed a significant association with success in an election when leptoprosopic candidates were paired against candidates of another facial phenotype (p US election candidates. Moreover, this facial phenotype appears to be associated with greater electoral success, supporting the concept of a modern political 'power face'. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  1. Effects of eHealth Literacy on General Practitioner Consultations: A Mediation Analysis

    Science.gov (United States)

    Fitzpatrick, Mary Anne; Hess, Alexandra; Sudbury-Riley, Lynn; Hartung, Uwe

    2017-01-01

    Background Most evidence (not all) points in the direction that individuals with a higher level of health literacy will less frequently utilize the health care system than individuals with lower levels of health literacy. The underlying reasons of this effect are largely unclear, though people’s ability to seek health information independently at the time of wide availability of such information on the Internet has been cited in this context. Objective We propose and test two potential mediators of the negative effect of eHealth literacy on health care utilization: (1) health information seeking and (2) gain in empowerment by information seeking. Methods Data were collected in New Zealand, the United Kingdom, and the United States using a Web-based survey administered by a company specialized on providing online panels. Combined, the three samples resulted in a total of 996 baby boomers born between 1946 and 1965 who had used the Internet to search for and share health information in the previous 6 months. Measured variables include eHealth literacy, Internet health information seeking, the self-perceived gain in empowerment by that information, and the number of consultations with one’s general practitioner (GP). Path analysis was employed for data analysis. Results We found a bundle of indirect effect paths showing a positive relationship between health literacy and health care utilization: via health information seeking (Path 1), via gain in empowerment (Path 2), and via both (Path 3). In addition to the emergence of these indirect effects, the direct effect of health literacy on health care utilization disappeared. Conclusions The indirect paths from health literacy via information seeking and empowerment to GP consultations can be interpreted as a dynamic process and an expression of the ability to find, process, and understand relevant information when that is necessary. PMID:28512081

  2. Interactive Analysis of General Beam Configurations using Finite Element Methods and JavaScript

    Science.gov (United States)

    Hernandez, Christopher

    Advancements in computer technology have contributed to the widespread practice of modelling and solving engineering problems through the use of specialized software. The wide use of engineering software comes with the disadvantage to the user of costs from the required purchase of software licenses. The creation of accurate, trusted, and freely available applications capable of conducting meaningful analysis of engineering problems is a way to mitigate to the costs associated with every-day engineering computations. Writing applications in the JavaScript programming language allows the applications to run within any computer browser, without the need to install specialized software, since all internet browsers are equipped with virtual machines (VM) that allow the browsers to execute JavaScript code. The objective of this work is the development of an application that performs the analysis of a completely general beam through use of the finite element method. The app is written in JavaScript and embedded in a web page so it can be downloaded and executed by a user with an internet connection. This application allows the user to analyze any uniform or non-uniform beam, with any combination of applied forces, moments, distributed loads, and boundary conditions. Outputs for this application include lists the beam deformations and slopes, as well as lateral and slope deformation graphs, bending stress distributions, and shear and a moment diagrams. To validate the methodology of the GBeam finite element app, its results are verified using the results from obtained from two other established finite element solvers for fifteen separate test cases.

  3. Pixel-based analysis of FRAP data with a general initial bleaching profile.

    Science.gov (United States)

    Jonasson, J K; Hagman, J; Lorén, N; Bernin, D; Nydén, M; Rudemo, M

    2010-08-01

    In Jonasson et al. (2008), we presented a new pixel-based maximum likelihood framework for the estimation of diffusion coefficients from data on fluorescence recovery after photobleaching (FRAP) with confocal laser scanning microscopy (CLSM). The main method there, called the Gaussian profile method below, is based on the assumption that the initial intensity profile after photobleaching is approximately Gaussian. In the present paper, we introduce a method, called the Monotone profile method, where the maximum likelihood framework is extended to a general initial bleaching profile only assuming that the profile is a non-decreasing function of the distance to the bleaching centre. The statistical distribution of the image noise is further assumed to be Poisson instead of normal, which should be a more realistic description of the noise in the detector. The new Monotone profile method and the Gaussian profile method are applied to FRAP data on swelling of super absorbent polymers (SAP) in water with a Fluorescein probe. The initial bleaching profile is close to a step function at low degrees of swelling and close to a Gaussian profile at high degrees of swelling. The results obtained from the analysis of the FRAP data are corroborated with NMR diffusometry analysis of SAP with a polyethylene glycol probe having size similar to the Fluorescein. The comparison of the Gaussian and Monotone profile methods is also performed by use of simulated data. It is found that the new Monotone profile method is accurate for all types of initial profiles studied, but it suffers from being computationally slow. The fast Gaussian profile method is sufficiently accurate for most of the profiles studied, but underestimates the diffusion coefficient for profiles close to a step function. We also provide a diagnostic plot, which indicates whether the Gaussian profile method is acceptable or not.

  4. Identifying model error in metabolic flux analysis - a generalized least squares approach.

    Science.gov (United States)

    Sokolenko, Stanislav; Quattrociocchi, Marco; Aucoin, Marc G

    2016-09-13

    The estimation of intracellular flux through traditional metabolic flux analysis (MFA) using an overdetermined system of equations is a well established practice in metabolic engineering. Despite the continued evolution of the methodology since its introduction, there has been little focus on validation and identification of poor model fit outside of identifying "gross measurement error". The growing complexity of metabolic models, which are increasingly generated from genome-level data, has necessitated robust validation that can directly assess model fit. In this work, MFA calculation is framed as a generalized least squares (GLS) problem, highlighting the applicability of the common t-test for model validation. To differentiate between measurement and model error, we simulate ideal flux profiles directly from the model, perturb them with estimated measurement error, and compare their validation to real data. Application of this strategy to an established Chinese Hamster Ovary (CHO) cell model shows how fluxes validated by traditional means may be largely non-significant due to a lack of model fit. With further simulation, we explore how t-test significance relates to calculation error and show that fluxes found to be non-significant have 2-4 fold larger error (if measurement uncertainty is in the 5-10 % range). The proposed validation method goes beyond traditional detection of "gross measurement error" to identify lack of fit between model and data. Although the focus of this work is on t-test validation and traditional MFA, the presented framework is readily applicable to other regression analysis methods and MFA formulations.

  5. Multiscale Static Analysis of Notched and Unnotched Laminates Using the Generalized Method of Cells

    Science.gov (United States)

    Naghipour Ghezeljeh, Paria; Arnold, Steven M.; Pineda, Evan J.; Stier, Bertram; Hansen, Lucas; Bednarcyk, Brett A.; Waas, Anthony M.

    2016-01-01

    The generalized method of cells (GMC) is demonstrated to be a viable micromechanics tool for predicting the deformation and failure response of laminated composites, with and without notches, subjected to tensile and compressive static loading. Given the axial [0], transverse [90], and shear [+45/-45] response of a carbon/epoxy (IM7/977-3) system, the unnotched and notched behavior of three multidirectional layups (Layup 1: [0,45,90,-45](sub 2S), Layup 2: [0,60,0](sub 3S), and Layup 3: [30,60,90,-30, -60](sub 2S)) are predicted under both tensile and compressive static loading. Matrix nonlinearity is modeled in two ways. The first assumes all nonlinearity is due to anisotropic progressive damage of the matrix only, which is modeled, using the multiaxial mixed-mode continuum damage model (MMCDM) within GMC. The second utilizes matrix plasticity coupled with brittle final failure based on the maximum principle strain criteria to account for matrix nonlinearity and failure within the Finite Element Analysis--Micromechanics Analysis Code (FEAMAC) software multiscale framework. Both MMCDM and plasticity models incorporate brittle strain- and stress-based failure criteria for the fiber. Upon satisfaction of these criteria, the fiber properties are immediately reduced to a nominal value. The constitutive response for each constituent (fiber and matrix) is characterized using a combination of vendor data and the axial, transverse, and shear responses of unnotched laminates. Then, the capability of the multiscale methodology is assessed by performing blind predictions of the mentioned notched and unnotched composite laminates response under tensile and compressive loading. Tabulated data along with the detailed results (i.e., stress-strain curves as well as damage evolution states at various ratios of strain to failure) for all laminates are presented.

  6. Structural dynamic analysis for time response of bars and trusses using the generalized finite element method

    Directory of Open Access Journals (Sweden)

    André Jacomel Torii

    Full Text Available The Generalized Finite Element Method (GFEM can be viewed as an extension of the Finite Element Method (FEM where the approximation space is enriched by shape functions appropriately chosen. Many applications of the GFEM can be found in literature, mostly when some information about the solution is known a priori. This paper presents the application of the GFEM to the problem of structural dynamic analysis of bars subject to axial displacements and trusses for the evaluation of the time response of the structure. Since the analytical solution of this problem is composed, in most cases, of a trigonometric series, the enrichment used in this paper is based on sine and cosine functions. Modal Superposition and the Newmark Method are used for the time integration procedure. Five examples are studied and the analytical solution is presented for two of them. The results are compared to the ones obtained with the FEM using linear elements and a Hierarchical Finite Element Method (HFEM using higher order elements.

  7. The 2013 general elections in Malaysia: An analysis of online news portals

    Directory of Open Access Journals (Sweden)

    Azahar Kasim

    2016-05-01

    Full Text Available This research analyzed the coverage of online news portals during the election campaign in Malaysia's 13th General Election on 5th May 2013. There were two types of news portals chosen for this research: 1 the mainstream online news portals, namely The Star Online, Berita Harian Online, Bernama Online and Utusan Online; and 2 the alternative news portals consisting of political parties' publications: the Harakah Daily, Roketkini and Keadilan Daily; and the independent news portals of The Malaysian Insider and Malaysiakini. This study was conducted starting from the nomination day on the 20th April 2013 until the polling day on the 5th May 2013. Results obtained were based on the frequencies of articles covering the ruling Barisan Nasional (BN party and the opposition Pakatan Rakyat (PR party. Each article was coded and labeled as positive, negative, or neutral coverage for each political party. The Content Analysis method was applied where the researchers chose and analyzed each election article and placed it in one of five categories; +BN (positive report, −BN (negative report, +PR (positive report, −PR (negative report and N (Neutral. The results showed that the four mainstream online news portals favored the BN with their coverage. However, the parties' online news portals clearly owned by PR alliance parties had completely opposite, bias toward their owners. The two independent news portals seemed to give more balanced coverage to both sides.

  8. Generalized moment analysis of magnetic field correlations for accumulations of spherical and cylindrical magnetic pertubers

    Directory of Open Access Journals (Sweden)

    Felix Tobias Kurz

    2016-12-01

    Full Text Available In biological tissue, an accumulation of similarly shaped objects with a susceptibility difference to the surrounding tissue generates a local distortion of the external magnetic field in magnetic resonance imaging. It induces stochastic field fluctuations that characteristically influence proton spin diffusion in the vicinity of these magnetic perturbers. The magnetic field correlation that is associated with such local magnetic field inhomogeneities can be expressed in the form of a dynamic frequency autocorrelation function that is related to the time evolution of the measured magnetization. Here, an eigenfunction expansion for two simple magnetic perturber shapes, that of spheres and cylinders, is considered for restricted spin diffusion in a simple model geometry. Then, the concept of generalized moment analysis, an approximation technique that is applied in the study of (non-reactive processes that involve Brownian motion, allows to provide analytical expressions for the correlation function for different exponential decay forms. Results for the biexponential decay for both spherical and cylindrical magnetized objects are derived and compared with the frequently used (less accurate monoexponential decay forms. They are in asymptotic agreement with the numerically exact value of the correlation function for long and short times.

  9. Analysis on difference of risk perception between people engaged in nuclear business and general public

    International Nuclear Information System (INIS)

    Terado, M.; Yoshikawa, H.; Sugiman, T.; Hibino, A.; Akimoto, M.

    2004-01-01

    A new research project has started to develop two kinds of on-the-web communication systems which are aimed at effective social risk information on nuclear energy. One is mutual communication system for fostering safety culture among the workers in nuclear industry while the other is to enlighten general public about the risk issues on final disposal of high-level radioactive waste. Prior to the on-the-web systems development, social investigations have been conducted on risk perception for nuclear power for both the nuclear experts and women in the metropolitan area, in order to know how and what should be considered for the effective risk communication methods. It was found from the statistical analysis of the results of social investigation that the majority of nuclear people take business risk seriously but there is a fraction of nuclear people who are afraid of present practice of nuclear power operation while women in metropolitan area are evenly afraid of radioactive risk. The obtained results of social investigation gave useful insight for developing two kinds of risk communication systems and the related field study for enhancing safety culture in nuclear industries. (authors)

  10. An analysis of the Rayleigh–Stokes problem for a generalized second-grade fluid

    KAUST Repository

    Bazhlekova, Emilia

    2014-11-26

    © 2014, The Author(s). We study the Rayleigh–Stokes problem for a generalized second-grade fluid which involves a Riemann–Liouville fractional derivative in time, and present an analysis of the problem in the continuous, space semidiscrete and fully discrete formulations. We establish the Sobolev regularity of the homogeneous problem for both smooth and nonsmooth initial data v, including v∈L2(Ω). A space semidiscrete Galerkin scheme using continuous piecewise linear finite elements is developed, and optimal with respect to initial data regularity error estimates for the finite element approximations are derived. Further, two fully discrete schemes based on the backward Euler method and second-order backward difference method and the related convolution quadrature are developed, and optimal error estimates are derived for the fully discrete approximations for both smooth and nonsmooth initial data. Numerical results for one- and two-dimensional examples with smooth and nonsmooth initial data are presented to illustrate the efficiency of the method, and to verify the convergence theory.

  11. Dark matter annihilations into two light fermions and one gauge boson. General analysis and antiproton constraints

    International Nuclear Information System (INIS)

    Garny, Mathias; Ibarra, Alejandro; Vogl, Stefan

    2011-12-01

    We study in this paper the scenario where the dark matter is constituted by Majo- rana particles which couple to a light Standard Model fermion and an extra scalar via a Yukawa coupling. In this scenario, the annihilation rate into the light fermions with the mediation of the scalar particle is strongly suppressed by the mass of the fermion. Nevertheless, the helicity suppression is lifted by the associated emission of a gauge boson, yielding annihilation rates which could be large enough to allow the indirect detection of the dark matter particles. We perform a general analysis of this scenario, calculating the annihilation cross section of the processes χχ → f anti fV when the dark matter particle is a SU(2) L singlet or doublet, f is a lepton or a quark, and V is a photon, a weak gauge boson or a gluon. We point out that the annihilation rate is particularly enhanced when the dark matter particle is degenerate in mass to the intermediate scalar particle, which is a scenario barely constrained by collider searches of exotic charged or colored particles. Lastly, we derive upper limits on the relevant cross sections from the non-observation of an excess in the cosmic antiproton-to-proton ratio measured by PAMELA. (orig.)

  12. Generalized linear discriminant analysis: a unified framework and efficient model selection.

    Science.gov (United States)

    Ji, Shuiwang; Ye, Jieping

    2008-10-01

    High-dimensional data are common in many domains, and dimensionality reduction is the key to cope with the curse-of-dimensionality. Linear discriminant analysis (LDA) is a well-known method for supervised dimensionality reduction. When dealing with high-dimensional and low sample size data, classical LDA suffers from the singularity problem. Over the years, many algorithms have been developed to overcome this problem, and they have been applied successfully in various applications. However, there is a lack of a systematic study of the commonalities and differences of these algorithms, as well as their intrinsic relationships. In this paper, a unified framework for generalized LDA is proposed, which elucidates the properties of various algorithms and their relationships. Based on the proposed framework, we show that the matrix computations involved in LDA-based algorithms can be simplified so that the cross-validation procedure for model selection can be performed efficiently. We conduct extensive experiments using a collection of high-dimensional data sets, including text documents, face images, gene expression data, and gene expression pattern images, to evaluate the proposed theories and algorithms.

  13. General Analysis of New Physics in $B\\to J/\\psi K$

    CERN Document Server

    Fleischer, Robert; Fleischer, Robert; Mannel, Thomas

    2001-01-01

    We present a model-independent parametrization of the $B^\\pm\\to J/\\psi K^\\pm$, $B_d\\to J/\\psi K_S$ decay amplitudes by taking into account the constraints that are implied by the isospin symmetry of strong interactions. Employing estimates borrowed from effective field theory, we explore the impact of physics beyond the Standard Model and introduce -- in addition to the usual mixing-induced CP asymmetry $A_{CP}^{mix}$ in $B_d\\to J/\\psi K_S$ -- a set of three observables, allowing a general analysis of possible new-physics effects in the $B\\to J/\\psi K$ system. Imposing a dynamical hierarchy of amplitudes, we argue that one of these observables may already be accessible at the first-generation $B$-factories, whereas the remaining ones will probably be left for second-generation $B$ experiments. However, in the presence of large rescattering effects, all three new-physics observables may be sizeable. We also emphasize that a small value of $A_{CP}^{mix}$ could be due to new-physics effects arising at the $B\\to ...

  14. Impacts Of External Price Shocks On Malaysian Macro Economy-An Applied General Equilibrium Analysis

    Directory of Open Access Journals (Sweden)

    Abul Quasem Al-Amin

    2008-10-01

    Full Text Available This paper examines the impacts of external price shocks in the Malaysian economy. There are three simulations are carried out with different degrees of external shocks using Malaysian Social Accounting Matrix (SAM and Computable General Equilibrium (CGE analysis. The model results indicate that the import price shocks, better known as external price shocks by 15% decreases the domestic production of building and construction sector by 25.87%, hotels, restaurants and entertainment sector by 12.04%, industry sector by 12.02%, agriculture sector by 11.01%, and electricity and gas sector by 9.55% from the baseline. On the import side, our simulation results illustrate that as a result of the import price shocks by 15%, imports decreases significantly in all sectors from base level. Among the scenarios, the largest negative impacts goes on industry sectors by 29.67% followed by building and construction sector by 22.42%, hotels, restaurants and entertainment sector by 19.45%, electricity and gas sector by 13.%, agriculture sector by 12.63% and other service sectors by 11.17%. However significant negative impact goes to the investment and fixed capital investment. It also causes the household income, household consumption and household savings down and increases the cost of livings in the economy results in downward social welfare.

  15. Statistical analysis of latent generalized correlation matrix estimation in transelliptical distribution.

    Science.gov (United States)

    Han, Fang; Liu, Han

    2017-02-01

    Correlation matrix plays a key role in many multivariate methods (e.g., graphical model estimation and factor analysis). The current state-of-the-art in estimating large correlation matrices focuses on the use of Pearson's sample correlation matrix. Although Pearson's sample correlation matrix enjoys various good properties under Gaussian models, its not an effective estimator when facing heavy-tail distributions with possible outliers. As a robust alternative, Han and Liu (2013b) advocated the use of a transformed version of the Kendall's tau sample correlation matrix in estimating high dimensional latent generalized correlation matrix under the transelliptical distribution family (or elliptical copula). The transelliptical family assumes that after unspecified marginal monotone transformations, the data follow an elliptical distribution. In this paper, we study the theoretical properties of the Kendall's tau sample correlation matrix and its transformed version proposed in Han and Liu (2013b) for estimating the population Kendall's tau correlation matrix and the latent Pearson's correlation matrix under both spectral and restricted spectral norms. With regard to the spectral norm, we highlight the role of "effective rank" in quantifying the rate of convergence. With regard to the restricted spectral norm, we for the first time present a "sign subgaussian condition" which is sufficient to guarantee that the rank-based correlation matrix estimator attains the optimal rate of convergence. In both cases, we do not need any moment condition.

  16. Clustering of eating disorder symptoms in a general population female twin sample: a latent class analysis.

    Science.gov (United States)

    Duncan, Alexis E; Bucholz, Kathleen Keenan; Neuman, Rosalind J; Agrawal, Arpana; Madden, Pamela A F; Heath, Andrew C

    2007-08-01

    Previous studies have reported that the current DSM-IV eating disorder (ED) criteria do not adequately describe ED symptomatology. The objective of the current study was to examine the clustering of ED symptoms in a general population sample using latent class analysis (LCA). ED symptoms from 3723 female young adult twins (mean age 22) were analyzed using LCA, and resulting classes were compared on external validators reflecting ED and other co-morbid psychiatric diagnoses, substance use disorders (SUDs), and suicidality. The optimal solution consisted of five latent classes characterized as: (1) Unaffected; (2) Low Weight Gain; (3) Weight Concerned; (4) Dieters; and (5) ED. Members of the ED class had significantly higher prevalence of co-morbid psychiatric disorders, SUDs, and suicidality than the Unaffected and Low Weight Gain classes, and elevated rates of suicidality and major depression compared to the Weight Concerned and Dieter classes, which differed from each other primarily in terms of current body mass index (BMI). Dieter class members were more likely to be overweight and obese and less likely to be underweight than Weight Concerned class members. The majority of women with an ED diagnosis were assigned to the ED class, and few differences were found between ED class members with and without an ED diagnosis. The results add to the evidence that many women with significant ED psychopathology are not being identified by the DSM-IV ED categories.

  17. The economic impacts of the September 11 terrorist attacks: a computable general equilibrium analysis

    Energy Technology Data Exchange (ETDEWEB)

    Oladosu, Gbadebo A [ORNL; Rose, Adam [University of Southern California, Los Angeles; Bumsoo, Lee [University of Illinois; Asay, Gary [University of Southern California

    2009-01-01

    This paper develops a bottom-up approach that focuses on behavioral responses in estimating the total economic impacts of the September 11, 2001, World Trade Center (WTC) attacks. The estimation includes several new features. First, is the collection of data on the relocation of firms displaced by the attack, the major source of resilience in muting the direct impacts of the event. Second, is a new estimate of the major source of impacts off-site -- the ensuing decline of air travel and related tourism in the U.S. due to the social amplification of the fear of terrorism. Third, the estimation is performed for the first time using Computable General Equilibrium (CGE) analysis, including a new approach to reflecting the direct effects of external shocks. This modeling framework has many advantages in this application, such as the ability to include behavioral responses of individual businesses and households, to incorporate features of inherent and adaptive resilience at the level of the individual decision maker and the market, and to gauge quantity and price interaction effects across sectors of the regional and national economies. We find that the total business interruption losses from the WTC attacks on the U.S. economy were only slightly over $100 billion, or less than 1.0% of Gross Domestic Product. The impacts were only a loss of $14 billion of Gross Regional Product for the New York Metropolitan Area.

  18. General practitioners' views on key factors affecting their desired income: A principal component analysis approach.

    Science.gov (United States)

    Bayati, Mohsen; Rashidian, Arash; Akbari Sari, Ali; Emamgholipour, Sara

    2017-01-01

    Background: Based on the target income hypothesis, the economic behavior of physicians is mainly affected by their target income. This study aimed at designing an instrument to explain how general practitioners (GPs) set their desired income. Methods: A self-administered questionnaire of affecting factors on GPs' target income was extracted from literature reviews and a small qualitative study. Respondents were 666 GPs who completed the questionnaire (response rate= 52%) during 2 seasonal congresses of Iranian GPs. The principal component analysis (PCA) with varimax rotation was used to classify the variables and data reduction. Sample adequacy test, sphericity test, eigenvalues of components, and scree plot were evaluated for PCA. Cronbach's alpha was also checked to assess the internal consistency of the principal components. Results: The results of the KMO measure of sampling adequacy (0.657) and Bartlett's test of sphericity (809.05, pluxury services were selected, which explained 65.19% of the total variance. Finally, only those with a Cronbach's alpha value higher than 0.6 were considered reliable (the first 4 components). Conclusion: Based on the target income hypothesis, a physician's desired level of income affects their behavior. Our developed instrument and its mentioned components can be used in future studies related to GPs' behavior, especially those studies related to the economic aspects of GPs' behavior. It also helps formulate a better payment mechanism for primary care providers.

  19. Essays on environmental policy analysis: Computable general equilibrium approaches applied to Sweden

    International Nuclear Information System (INIS)

    Hill, M.

    2001-01-01

    This thesis consists of three essays within the field of applied environmental economics, with the common basic aim of analyzing effects of Swedish environmental policy. Starting out from Swedish environmental goals, the thesis assesses a range of policy-related questions. The objective is to quantify policy outcomes by constructing and applying numerical models especially designed for environmental policy analysis. Static and dynamic multi-sectoral computable general equilibrium models are developed in order to analyze the following issues. The costs and benefits of a domestic carbon dioxide (CO 2 ) tax reform. Special attention is given to how these costs and benefits depend on the structure of the tax system and, furthermore, how they depend on policy-induced changes in 'secondary' pollutants. The effects of allowing for emission permit trading through time when the domestic long-term domestic environmental goal is specified in CO 2 stock terms. The effects on long-term projected economic growth and welfare that are due to damages from emission flow and accumulation of 'local' pollutants (nitrogen oxides and sulfur dioxide), as well as the outcome of environmental policy when costs and benefits are considered in an integrated environmental-economic framework

  20. Reliability analysis of a phaser measurement unit using a generalized fuzzy lambda-tau(GFLT) technique.

    Science.gov (United States)

    Komal

    2018-02-23

    Nowadays power consumption is increasing day-by-day. To fulfill failure free power requirement, planning and implementation of an effective and reliable power management system is essential. Phasor measurement unit(PMU) is one of the key device in wide area measurement and control systems. The reliable performance of PMU assures failure free power supply for any power system. So, the purpose of the present study is to analyse the reliability of a PMU used for controllability and observability of power systems utilizing available uncertain data. In this paper, a generalized fuzzy lambda-tau (GFLT) technique has been proposed for this purpose. In GFLT, system components' uncertain failure and repair rates are fuzzified using fuzzy numbers having different shapes such as triangular, normal, cauchy, sharp gamma and trapezoidal. To select a suitable fuzzy number for quantifying data uncertainty, system experts' opinion have been considered. The GFLT technique applies fault tree, lambda-tau method, fuzzified data using different membership functions, alpha-cut based fuzzy arithmetic operations to compute some important reliability indices. Furthermore, in this study ranking of critical components of the system using RAM-Index and sensitivity analysis have also been performed. The developed technique may be helpful to improve system performance significantly and can be applied to analyse fuzzy reliability of other engineering systems. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  1. ANALISIS DERAJAT KESEHATAN MASYARAKAT PROVINSI BALI DENGAN MENGGUNAKAN METODE GENERALIZED STRUCTURED COMPONENT ANALYSIS (GSCA

    Directory of Open Access Journals (Sweden)

    PUTU NOPITA PURNAMA NINGSIH

    2013-09-01

    Full Text Available The aim of this research is to determine the relationship between environmental, behavioral, health services, education, and economic variables to health status in the Province of Bali. These variables are constructs (latents that can not be measured directly by observation. If there was a relationship between latent and its indicators, it is recomended to use Structural Equation Modeling (SEM. In this research we used variance-based SEM i.e. Generalized Structured Component Analysis (GSCA. This method not based on many assumptions such as the data does not have a multivariate normal distribution, the sample size does is not necessary large. Moreover, GSCA provides by overall goodness-fit of the model. The result of this research indicates that the environmental, behavioral, economic and educational variable influenced health status, but health service does not significantly affect the health status; economic does not significantly affect the environment; and education does not significantly affect the behavior. The result of the FIT value ?0.450 and the AFIT value 0.429 showed that overall model in this research is not good enough because of both of these values are under 0.50.

  2. General analytical solutions for DC/AC circuit-network analysis

    Science.gov (United States)

    Rubido, Nicolás; Grebogi, Celso; Baptista, Murilo S.

    2017-06-01

    In this work, we present novel general analytical solutions for the currents that are developed in the edges of network-like circuits when some nodes of the network act as sources/sinks of DC or AC current. We assume that Ohm's law is valid at every edge and that charge at every node is conserved (with the exception of the source/sink nodes). The resistive, capacitive, and/or inductive properties of the lines in the circuit define a complex network structure with given impedances for each edge. Our solution for the currents at each edge is derived in terms of the eigenvalues and eigenvectors of the Laplacian matrix of the network defined from the impedances. This derivation also allows us to compute the equivalent impedance between any two nodes of the circuit and relate it to currents in a closed circuit which has a single voltage generator instead of many input/output source/sink nodes. This simplifies the treatment that could be done via Thévenin's theorem. Contrary to solving Kirchhoff's equations, our derivation allows to easily calculate the redistribution of currents that occurs when the location of sources and sinks changes within the network. Finally, we show that our solutions are identical to the ones found from Circuit Theory nodal analysis.

  3. A spatial analysis of the expanding roles of nurses in general practice

    Directory of Open Access Journals (Sweden)

    Pearce Christopher

    2012-08-01

    Full Text Available Abstract Background Changes to the workforce and organisation of general practice are occurring rapidly in response to the Australian health care reform agenda, and the changing nature of the medical profession. In particular, the last five years has seen the rapid introduction and expansion of a nursing workforce in Australian general practices. This potentially creates pressures on current infrastructure in general practice. Method This study used a mixed methods, ‘rapid appraisal’ approach involving observation, photographs, and interviews. Results Nurses utilise space differently to GPs, and this is part of the diversity they bring to the general practice environment. At the same time their roles are partly shaped by the ways space is constructed in general practices. Conclusion The fluidity of nursing roles in general practice suggests that nurses require a versatile space in which to maximize their role and contribution to the general practice team.

  4. ANALYSIS OF MODELS OF EARLY DEBT REPAYMENT IN THE Generalized CREDIT TRANSACTIONS

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available This paper analyzes the patterns of early repayment in multi-period credit transactions. Considered one of the most common ways of conversion of unpaid interest for early repayment, so-called 78 rule. The relationship of this rule with the linear approximation of the exact value; redeemable debt is determined. The analysis of the maximum excess payment of interest on 78 rule. It has been shown how interest payment on 78 rule depended on the time of early repayment. Early repayment of debt is an agreement under which the borrower pays to the lender amount of money equal to the current balance (as of loan account. Then further regular payments cease and the contract terminates. However, the amount of outstanding debt is determined by the structure of prescription charges. So in the uniform schemes of repayment of consumer credit each payment contains the same part of principal amounts and the total interest. In case of early repayment the Bank loses a significant fraction of the expected interest payments. Therefore, in practice, often used so-called accelerated schemes of interest payments. One of them is 78 rule. Use the 78 rule is simple and straightforward. The name of the rule is due to the fact that the sum of the numbers 12 monthly payments is 78. In the schemes of consumer loan with a term of one year interest payment for the current month is equal to m/78 of the total amount of interest payments, where m is the number of remaining payments. The rule name is stored and in the more general case with an arbitrary number of payments. In general interest payment is determined by the relative weight of the total amount of interest in each payment. In uniform schemes it is constant. In accelerated with a particular speed decreases. Therefore, additional cash expenses by the 78 rule may be considered as additional penalties for early repayment of the debt. It this article is shown how this penalty depends on time before maturity. It is shown that

  5. Implementation of the Generalized Brazier Effect in Analysis of Wind Turbine Blades

    DEFF Research Database (Denmark)

    Lauridsen, Peter Riddersholm; Nikolajsen, Jan Ánike; Damkilde, Lars

    2016-01-01

    As wind turbine blades are getting longer and more slender, new failure modes occur and these may be related to the non-linear geometric Brazier effect1,2,3, where the bending moments ovalize the thin-walled cross-sections. For general cross-sections the torsional moments have a similar effect....... The combined effect is denoted the general Brazier effect, and it is described in an accompanying paper. The stresses caused by the generalized Brazier effect are directed perpendicular to the beam axis, and this may have a large influence on the fatigue life of composite structure. The generalized Brazier...

  6. A philosophical analysis of the general methodology of qualitative research: a critical rationalist perspective.

    Science.gov (United States)

    Rudnick, Abraham

    2014-09-01

    Philosophical discussion of the general methodology of qualitative research, such as that used in some health research, has been inductivist or relativist to date, ignoring critical rationalism as a philosophical approach with which to discuss the general methodology of qualitative research. This paper presents a discussion of the general methodology of qualitative research from a critical rationalist perspective (inspired by Popper), using as an example mental health research. The widespread endorsement of induction in qualitative research is positivist and is suspect, if not false, particularly in relation to the context of justification (or rather theory testing) as compared to the context of discovery (or rather theory generation). Relativism is riddled with philosophical weaknesses and hence it is suspect if not false too. Theory testing is compatible with qualitative research, contrary to much writing about and in qualitative research, as theory testing involves learning from trial and error, which is part of qualitative research, and which may be the form of learning most conducive to generalization. Generalization involves comparison, which is a fundamental methodological requirement of any type of research (qualitative or other); hence the traditional grounding of quantitative and experimental research in generalization. Comparison--rather than generalization--is necessary for, and hence compatible with, qualitative research; hence, the common opposition to generalization in qualitative research is misdirected, disregarding whether this opposition's claims are true or false. In conclusion, qualitative research, similar to quantitative and experimental research, assumes comparison as a general methodological requirement, which is necessary for health research.

  7. Full Spectrum Operations: An Analysis of Course Content at the Command and General Staff College

    National Research Council Canada - National Science Library

    Turner, II, Frank L

    2008-01-01

    .... This monograph examined the Intermediate Level Education, the Advanced Military Studies Program, and the Tactical Commanders Development Program curricula at the Command and General Staff College...

  8. Hamiltonian analysis of the double null 2 + 2 decomposition of general relativity expressed in terms of self-dual bivectors

    Energy Technology Data Exchange (ETDEWEB)

    D' Inverno, R A; Lambert, P; Vickers, J A [School of Mathematics, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2006-07-07

    In this paper, we obtain a 2 + 2 double null Hamiltonian description of general relativity using only the (complex) SO(3) connection and the components of the complex densitized self-dual bivectors {sigma}{sub A}. We carry out the general canonical analysis of this system and obtain the first class constraint algebra entirely in terms of the self-dual variables. The first class algebra forms a Lie algebra and all the first class constraints have a simple geometrical interpretation.

  9. Analysis of postdischarge costs following emergent general surgery in elderly patients.

    Science.gov (United States)

    Eamer, Gilgamesh J; Clement, Fiona; Pederson, Jenelle L; Churchill, Thomas A; Khadaroo, Rachel G

    2018-02-01

    As populations age, more elderly patients will undergo surgery. Frailty and complications are considered to increase in-hospital cost in older adults, but little is known on costs following discharge, particularly those borne by the patient. We examined risk factors for increased cost and the type of costs accrued following discharge in elderly surgical patients. Acute abdominal surgery patients aged 65 years and older were prospectively enrolled. We assessed baseline clinical characteristics, including Clinical Frailty Scale (CFS) scores. We calculated 6-month cost (in Canadian dollars) from patient-reported use following discharge according to the validated Health Resource Utilization Inventory. Primary outcomes were 6-month overall cost and cost for health care services, medical products and lost productive hours. Outcomes were log-transformed and assessed in multivariable generalized linear and zero-inflated negative binomial regressions and can be interpreted as adjusted ratios (AR). Complications were assessed according to Clavien-Dindo classification. We included 150 patients (mean age 75.5 ± 7.6 yr; 54.1% men) in our analysis; 10.8% had major and 43.2% had minor complications postoperatively. The median 6-month overall cost was $496 (interquartile range $140-$1948). Disaggregated by cost type, frailty independently predicted increasing costs of health care services (AR 1.76, 95% confidence interval [CI] 1.43-2.18, p < 0.001) and medical products (AR 1.61, 95% CI 1.15-2.25, p = 0.005), but decreasing costs in lost productive hours (AR 0.39, p = 0.002). Complications did not predict increased cost. Frail patients accrued higher health care services and product costs, but lower costs from lost productive hours. Interventions in elderly surgical patients should consider patient-borne cost in older adults and lost productivity in less frail patients. NCT02233153 (clinicaltrials.gov).

  10. A latent class analysis of psychotic symptoms in the general population.

    Science.gov (United States)

    Pignon, Baptiste; Peyre, Hugo; Szöke, Andrei; Geoffroy, Pierre A; Rolland, Benjamin; Jardri, Renaud; Thomas, Pierre; Vaiva, Guillaume; Roelandt, Jean-Luc; Benradia, Imane; Behal, Hélène; Schürhoff, Franck; Amad, Ali

    2017-12-01

    Individuals with psychotic symptoms may actually correspond to various subgroups, characterized by different patterns of psychotic symptoms as well as specific sociodemographic and clinical correlates. We aimed to identify groups of individuals from the general population with specific patterns of psychotic symptoms. In a 38,694-subject survey, a latent class analysis was performed to identify subgroups based on the distribution of seven psychotic symptoms taken from the Mini International Neuropsychiatric Interview. The different classes were subsequently compared according to sociodemographic and clinical correlates. The best fit was obtained with a four-class solution, including the following: (1) a class with a low prevalence of all psychotic symptoms ('LOW', 85.9%); (2) a class with a high prevalence of all psychotic symptoms ('HAL + DEL', 1.7%); and classes with a high prevalence of (3) hallucinations ('HAL', 4.5%) or (4) delusions ('DEL', 7.9%). The HAL + DEL class displayed higher rates of history of trauma, social deprivation and migrant status, while the HAL and DEL classes displayed intermediate rates between HAL + DEL and LOW. HAL + DEL displayed the highest rates of psychotic and non-psychotic disorders and the use of mental health treatment, while HAL and DEL displayed intermediate rates of these disorders between HAL + DEL and LOW. In comparison to the HAL class, psychotic and substance use disorders were more frequent in the DEL class, while anxiety and mood disorders were less frequent. These findings support the hypothesis of a continuum model relating the level of psychotic symptoms to the level of global psychopathology.

  11. Analysis of time to event outcomes in randomized controlled trials by generalized additive models.

    Directory of Open Access Journals (Sweden)

    Christos Argyropoulos

    Full Text Available Randomized Controlled Trials almost invariably utilize the hazard ratio calculated with a Cox proportional hazard model as a treatment efficacy measure. Despite the widespread adoption of HRs, these provide a limited understanding of the treatment effect and may even provide a biased estimate when the assumption of proportional hazards in the Cox model is not verified by the trial data. Additional treatment effect measures on the survival probability or the time scale may be used to supplement HRs but a framework for the simultaneous generation of these measures is lacking.By splitting follow-up time at the nodes of a Gauss Lobatto numerical quadrature rule, techniques for Poisson Generalized Additive Models (PGAM can be adopted for flexible hazard modeling. Straightforward simulation post-estimation transforms PGAM estimates for the log hazard into estimates of the survival function. These in turn were used to calculate relative and absolute risks or even differences in restricted mean survival time between treatment arms. We illustrate our approach with extensive simulations and in two trials: IPASS (in which the proportionality of hazards was violated and HEMO a long duration study conducted under evolving standards of care on a heterogeneous patient population.PGAM can generate estimates of the survival function and the hazard ratio that are essentially identical to those obtained by Kaplan Meier curve analysis and the Cox model. PGAMs can simultaneously provide multiple measures of treatment efficacy after a single data pass. Furthermore, supported unadjusted (overall treatment effect but also subgroup and adjusted analyses, while incorporating multiple time scales and accounting for non-proportional hazards in survival data.By augmenting the HR conventionally reported, PGAMs have the potential to support the inferential goals of multiple stakeholders involved in the evaluation and appraisal of clinical trial results under proportional and

  12. Thermo-mechanical buckling analysis of FGM plate using generalized plate theory

    Science.gov (United States)

    Sharma, Kanishk; Kumar, Dinesh; Gite, Anil

    2016-05-01

    This paper investigates the thermo-mechanical buckling behavior of simply-supported FGM plate under the framework of generalized plate theory (GPT), which includes classical plate theory (CPT), first order shear deformation theory (FSDT) and higher order shear deformation theory (HSDT) as special cases. The governing equations for FGM plate under thermal and mechanical loading conditions are derived from the principle of virtual displacements and Navier-type solution is assumed for simply supported boundary condition. The efficiency and applicability of presented methodology is illustrated by considering various examples of thermal and mechanical buckling of FGM plates. The closed form solutions in the form of critical thermal and mechanical buckling loads, predicted by CPT, FSDT and HSDT are compared for different side-to-thickness of FGM plate. Subsequently, the effect of material gradation profile on critical buckling parameters is examined by evaluating the buckling response for a range of power law indexes. The effect of geometrical parameters on mechanical buckling of FGM plate under uni-axial and bi-axial loading conditions are also illustrated by calculating the critical load for various values of slenderness ratios. Furthermore a comparative analysis of critical thermal buckling loads of FGM plate for different temperature profiles is also presented. It is identified that all plate theories predicted approximately same critical buckling loads and critical buckling temperatures for thin FGM plate, however for thick FGM plates, CPT overestimates the critical buckling parameters. Moreover the critical buckling loads and critical buckling temperatures of FGM plate are found to be significantly lower than the corresponding homogenous isotropic ceramic plate (n=0).

  13. EEG analysis of seizure patterns using visibility graphs for detection of generalized seizures.

    Science.gov (United States)

    Wang, Lei; Long, Xi; Arends, Johan B A M; Aarts, Ronald M

    2017-10-01

    The traditional EEG features in the time and frequency domain show limited seizure detection performance in the epileptic population with intellectual disability (ID). In addition, the influence of EEG seizure patterns on detection performance was less studied. A single-channel EEG signal can be mapped into visibility graphs (VGS), including basic visibility graph (VG), horizontal VG (HVG), and difference VG (DVG). These graphs were used to characterize different EEG seizure patterns. To demonstrate its effectiveness in identifying EEG seizure patterns and detecting generalized seizures, EEG recordings of 615h on one EEG channel from 29 epileptic patients with ID were analyzed. A novel feature set with discriminative power for seizure detection was obtained by using the VGS method. The degree distributions (DDs) of DVG can clearly distinguish EEG of each seizure pattern. The degree entropy and power-law degree power in DVG were proposed here for the first time, and they show significant difference between seizure and non-seizure EEG. The connecting structure measured by HVG can better distinguish seizure EEG from background than those by VG and DVG. A traditional EEG feature set based on frequency analysis was used here as a benchmark feature set. With a support vector machine (SVM) classifier, the seizure detection performance of the benchmark feature set (sensitivity of 24%, FD t /h of 1.8s) can be improved by combining our proposed VGS features extracted from one EEG channel (sensitivity of 38%, FD t /h of 1.4s). The proposed VGS-based features can help improve seizure detection for ID patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. The current situation of inorganic elements in marine turtles: A general review and meta-analysis.

    Science.gov (United States)

    Cortés-Gómez, Adriana A; Romero, Diego; Girondot, Marc

    2017-10-01

    Inorganic elements (Pb, Cd, Hg, Al, As, Cr, Cu, Fe, Mn, Ni, Se and Zn) are present globally in aquatic systems and their potential transfer to marine turtles can be a serious threat to their health status. The environmental fate of these contaminants may be traced by the analysis of turtle tissues. Loggerhead turtles (Caretta caretta) are the most frequently investigated of all the sea turtle species with regards to inorganic elements, followed by Green turtles (Chelonia mydas); all the other species have considerably fewer studies. Literature shows that blood, liver, kidney and muscle are the tissues most frequently used for the quantification of inorganic elements, with Pb, Cd, Cu and Zn being the most studied elements. Chelonia mydas showed the highest concentrations of Cr in muscle (4.8 ± 0.12), Cu in liver (37 ± 7) and Mg in kidney (17 μg g -1 ww), Cr and Cu from the Gulf of Mexico and Mg from Japanese coasts; Lepidochelys olivacea presented the highest concentrations of Pb in blood (4.46 5) and Cd in kidney (150 ± 110 μg g -1 ww), both from the Mexican Pacific; Caretta caretta from the Mediterranean Egyptian coast had the highest report of Hg in blood (0.66 ± 0.13 μg g -1 ww); and Eretmochelys imbricata from Japan had the highest concentration of As in muscle (30 ± 13 13 μg g -1 ww). The meta-analysis allows us to examine some features that were not visible when data was analyzed alone. For instance, Leatherbacks show a unique pattern of concentration compared to other species. Additionally, contamination of different tissues shows some tendencies independent of the species with liver and kidney on one side and bone on the other being different from other tissues. This review provides a general perspective on the accumulation and distribution of these inorganic elements alongside existing information for the 7 sea turtle species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. A Qualitative Analysis of General Receptive Vocabulary of Adolescents with Down Syndrome

    Science.gov (United States)

    Facon, Bruno; Nuchadee, Marie-Laure; Bollengier, Therese

    2012-01-01

    This study aimed to discover whether general receptive vocabulary is qualitatively phenotypical in Down syndrome. Sixty-two participants with Down syndrome (M age = 16.74 years, SD = 3.28) were individually matched on general vocabulary raw total score with 62 participants with intellectual disability of undifferentiated etiology (M age = 16.20…

  16. Interpreted consultations as ‘business as usual’? : An analysis of organizational routines in general practices

    NARCIS (Netherlands)

    Greenhagh, T.; Voisey, C.J.; Robb, N.

    2007-01-01

    UK general practices operate in an environment of high linguistic diversity, because of recent large-scale immigration and of the NHS's commitment to provide a professional interpreter to any patient if needed. Much activity in general practice is co-ordinated and patterned into organisational

  17. Studying emotion theories through connectivity analysis: Evidence from generalized psychophysiological interactions and graph theory.

    Science.gov (United States)

    Huang, Yun-An; Jastorff, Jan; Van den Stock, Jan; Van de Vliet, Laura; Dupont, Patrick; Vandenbulcke, Mathieu

    2018-05-15

    Psychological construction models of emotion state that emotions are variable concepts constructed by fundamental psychological processes, whereas according to basic emotion theory, emotions cannot be divided into more fundamental units and each basic emotion is represented by a unique and innate neural circuitry. In a previous study, we found evidence for the psychological construction account by showing that several brain regions were commonly activated when perceiving different emotions (i.e. a general emotion network). Moreover, this set of brain regions included areas associated with core affect, conceptualization and executive control, as predicted by psychological construction models. Here we investigate directed functional brain connectivity in the same dataset to address two questions: 1) is there a common pathway within the general emotion network for the perception of different emotions and 2) if so, does this common pathway contain information to distinguish between different emotions? We used generalized psychophysiological interactions and information flow indices to examine the connectivity within the general emotion network. The results revealed a general emotion pathway that connects neural nodes involved in core affect, conceptualization, language and executive control. Perception of different emotions could not be accurately classified based on the connectivity patterns from the nodes of the general emotion pathway. Successful classification was achieved when connections outside the general emotion pathway were included. We propose that the general emotion pathway functions as a common pathway within the general emotion network and is involved in shared basic psychological processes across emotions. However, additional connections within the general emotion network are required to classify different emotions, consistent with a constructionist account. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Impact of a carbon tax on the Chilean economy: A computable general equilibrium analysis

    International Nuclear Information System (INIS)

    García Benavente, José Miguel

    2016-01-01

    In 2009, the government of Chile announced their official commitment to reduce national greenhouse gas emissions by 20% below a business-as-usual projection by 2020. Due to the fact that an effective way to reduce emissions is to implement a national carbon tax, the goal of this article is to quantify the value of a carbon tax that will allow the achievement of the emission reduction target and to assess its impact on the economy. The approach used in this work is to compare the economy before and after the implementation of the carbon tax by creating a static computable general equilibrium model of the Chilean economy. The model developed here disaggregates the economy in 23 industries and 23 commodities, and it uses four consumer agents (households, government, investment, and the rest of the world). By setting specific production and consumptions functions, the model can assess the variation in commodity prices, industrial production, and agent consumption, allowing a cross-sectoral analysis of the impact of the carbon tax. The benchmark of the economy, upon which the analysis is based, came from a social accounting matrix specially constructed for this model, based on the year 2010. The carbon tax was modeled as an ad valorem tax under two scenarios: tax on emissions from fossil fuels burned only by producers and tax on emissions from fossil fuels burned by producers and households. The abatement cost curve has shown that it is more cost-effective to tax only producers, rather than to tax both producers and households. This is due to the fact that when compared to the emission level observed in 2010, a 20% emission reduction will cause a loss in GDP of 2% and 2.3% respectively. Under the two scenarios, the tax value that could lead to that emission reduction is around 26 US dollars per ton of CO 2 -equivalent. The most affected productive sectors are oil refinery, transport, and electricity — having a contraction between 7% and 9%. Analyzing the electricity

  19. Benchmarking of protein carbonylation analysis in Caenorhabditis elegans: specific considerations and general advice.

    Science.gov (United States)

    Pyr Dit Ruys, S; Bonzom, J-M; Frelon, S

    2016-10-01

    Oxidative stress has been extensively studied due to its correlation with cellular disorders and aging. In proteins, one biomarker of oxidative stress is the presence of carbonyl groups, such as aldehyde and ketone, in specific amino acid side chains such as lysine, proline, arginine and threonine, so-called protein carbonylation (PC). PC study is now a growing field in general and medical science since PC accumulation is associated with various pathologies and disorders. At present, enzyme-linked immunosorbent assays (ELISA) seem to be the most robust method of quantifying the presence of carbonyl groups in proteins, despite having some recognised caveats. In parallel, gel-based approaches present cross-comparison difficulties, along with other technical problems. As generic PC analyses still suffer from poor homogeneity, leading to cross-data analysis difficulties and poor results overlap, the need for harmonisation in the field of carbonyl detection is now widely accepted. This study aims to highlight some of the technical challenges in proteomic gel-based multiplexing experiments when dealing with PC in difficult samples like those from Caenorhabditis elegans, from protein extraction to carbonyl detection. We demonstrate that some critical technical parameters, such as labelling time, probe concentration, and total and carbonylated protein recovery rates, should be re-addressed in a sample-specific way. We also defined a procedure to cost-effectively adapt CyDye™-hydrazide-based protocols to specific samples, especially when the experimental interest is focused on studying differences between stimulating conditions with a maximised signal-to-noise ratio. Moreover, we have improved an already-existing powerful solubilisation buffer, making it potentially useful for hard-to-solubilise protein pellets. Lastly, the depicted methodology exemplifies a simple way of normalising carbonyl-related signal to total protein in SDS-PAGE multiplexing experiments. Within

  20. Regional versus General Anesthesia for Percutaneous Nephrolithotomy: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Henglong Hu

    Full Text Available To compare the effectiveness and safety of regional anesthesia (RA and general anesthesia (GA for percutaneous nephrolithotomy (PNL.PubMed, EMBASE, The Cochrane Library, and the Web of Knowledge databases were systematically searched to identify relevant studies. After literature screening and data extraction, a meta-analysis was performed using the RevMan 5.3 software.Eight randomized controlled trials (RCTs and six non-randomized controlled trials (nRCTs involving 2270 patients were included. Patients receiving RA were associated with shorter operative time (-6.22 min; 95%CI, -9.70 to -2.75; p = 0.0005, lower visual analgesic score on the first and third postoperative day (WMD, -2.62; 95%CI, -3.04 to -2.19; p < 0.00001 WMD, -0.38; 95%CI, -0.58 to -0.18; p = 0.0002, less analgesic requirements (WMD, -59.40 mg; 95%CI, -78.39 to -40.40; p<0.00001, shorter hospitalization (WMD, -0.36d; 95%CI, -0.66 to -0.05; p = 0.02, less blood transfusion (RR, 0.61; 95%CI, 0.41 to 0.93; p = 0.02, fewer modified Clavion-Dindo Grade II (RR, 0.56; 95%CI, 0.37 to 0.83; p = 0.005, Grade III or above postoperative complications (RR, 0.51; 95%CI, 0.33 to 0.77; p = 0.001, and potential benefits of less fever (RR, 0.79; 95%CI, 0.61 to 1.02; p = 0.07, nausea or vomiting (RR, 0.54; 95%CI, 0.20 to 1.46; p = 0.23, whereas more intraoperative hypotension (RR, 3.13; 95%CI, 1.76 to 5.59; p = 0.0001 when compared with patients receiving GA. When nRCTs were excluded, most of the results were stable but the significant differences were no longer detectable in blood transfusion, Grade II and more severe complications. No significant difference in the total postoperative complications and stone-free rate were found.Current evidence suggests that both RA and GA can provide safe and effective anesthesia for PNL in carefully evaluated and selected patients. Each anesthesia technique has its own advantages but some aspects still remain unclear and need to be explored in future studies.

  1. Dual-tracer PET using generalized factor analysis of dynamic sequences.

    Science.gov (United States)

    El Fakhri, Georges; Trott, Cathryn M; Sitek, Arkadiusz; Bonab, Ali; Alpert, Nathaniel M

    2013-12-01

    With single-photon emission computed tomography, simultaneous imaging of two physiological processes relies on discrimination of the energy of the emitted gamma rays, whereas the application of dual-tracer imaging to positron emission tomography (PET) imaging has been limited by the characteristic 511-keV emissions. To address this limitation, we developed a novel approach based on generalized factor analysis of dynamic sequences (GFADS) that exploits spatio-temporal differences between radiotracers and applied it to near-simultaneous imaging of 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) (brain metabolism) and (11)C-raclopride (D2) with simulated human data and experimental rhesus monkey data. We show theoretically and verify by simulation and measurement that GFADS can separate FDG and raclopride measurements that are made nearly simultaneously. The theoretical development shows that GFADS can decompose the studies at several levels: (1) It decomposes the FDG and raclopride study so that they can be analyzed as though they were obtained separately. (2) If additional physiologic/anatomic constraints can be imposed, further decomposition is possible. (3) For the example of raclopride, specific and nonspecific binding can be determined on a pixel-by-pixel basis. We found good agreement between the estimated GFADS factors and the simulated ground truth time activity curves (TACs), and between the GFADS factor images and the corresponding ground truth activity distributions with errors less than 7.3 ± 1.3 %. Biases in estimation of specific D2 binding and relative metabolism activity were within 5.9 ± 3.6 % compared to the ground truth values. We also evaluated our approach in simultaneous dual-isotope brain PET studies in a rhesus monkey and obtained accuracy of better than 6 % in a mid-striatal volume, for striatal activity estimation. Dynamic image sequences acquired following near-simultaneous injection of two PET radiopharmaceuticals can be separated

  2. Mortality Analysis of Trauma Patients in General Intensive Care Unit of a State Hospital

    Directory of Open Access Journals (Sweden)

    İskender Kara

    2015-08-01

    Full Text Available Objective: The aim of this study was to determine the mortality rate and factors affecting the mortality of trauma patients in general intensive care unit (ICU of a state hospital. Material and Method: Data of trauma patients hospitalized between January 2012 and March 2013 in ICU of Konya Numune Hospital were retrospectively analyzed. Demographic characteristics and clinical data of patients were recorded. Patients were divided into two groups as survivors and dead. Mortality rate and factors affectin mortality were examined. Results: A total of 108 trauma patients were included in the study. The mortality rate of overall group was 19.4%. Median age of the patients was 44.5 years and 75.9% of them were males. Median Glasgow Coma Scale of death group was lower (5 (3-8 vs. 15 (13-15, p<0.0001, median APACHE II score was higher (20 (15-26 vs. 10 (8-13, p<0.0001 and median duration of ICU stay was longer (27 (5-62,5 vs. 2 (1-5, p<0.0001 than those in the survival group. The most common etiology of trauma was traffic accidents (47.2% and 52.7% of patients had head trauma. The rate of patients with any fracture was significantly higher in the survival group (66.7% vs. 33.3%, p=0.007. The rate of erythrocyte suspension, fresh frozen plasma, trombocyte suspension and albumin were 38.9%, 27.8%, 0.9% and 8.3%, respectively in all group. The number of patients invasive mechanically ventilated was 27.8% and median length of stay of these patients were 5 (1.75-33.5 days. The rate of operated patients was 42.6%. The rate of tracheostomy, renal replacement therapy, bronchoscopy and percutaneous endoscopic gastrostomy enforcements were higher in the death group. The advanced age (p=0.016, OR: 1.054; 95% CI: 1.010-1100 and low GCS (p<0.0001, OR: 0.583; 95% CI: 0.456-0.745 were found to be independent risk factors the ICU mortality of trauma patients in logistic regression analysis. Conclusion: We believe that the determination of these risk factors affecting

  3. [Teaching basic life support to the general population. Alumni intervention analysis].

    Science.gov (United States)

    Díaz-Castellanos, M A; Fernández-Carmona, A; Díaz-Redondo, A; Cárdenas-Cruz, A; García-del Moral, R; Martín-Lopez, J; Díaz-Redondo, T

    2014-12-01

    The aim of this study was to investigate the rate at which the alumni of basic life support courses witnessed and intervened in out-of-hospital emergency situations, and to identify the variables characterizing those alumni associated with a greater number of witnessing events and interventions. An analysis of the efficiency of the courses was also carried out. A descriptive, cross-sectional study was made. A district in the province of Almería (Spain). Alumni of a mass basic life support training program targeted to the general population «Plan Salvavidas» conducted between 2003-2009. In 2010 the alumni were administered a telephone survey asking whether they had witnessed an emergency situation since attending the program, with the collection of information related to this emergency situation. Rate of out-of-hospital emergencies witnessed by the alumni. Rate of intervention of the alumni in emergency situations. Variables characterizing alumni with a greater likelihood of witnessing an emergency situation. A total of 3,864 trained alumni were contacted by telephone. Of 1,098 respondents, 63.9% were women, and the mean age was 26.61±10.6 years. Of these alumni, 11.75% had witnessed emergency situations, an average of three years after completing the course. Of these emergencies, 23.3% were identified as cardiac arrest. The alumni intervened in 98% of the possible cases. In 63% of the cases, there was no connection between the alumni and the victim. The majority of the emergency situations occurred in the street and in public spaces. A greater likelihood of witnessing an emergency situation was associated with being a healthcare worker and with being over 18 years of age. The rate of out-of-hospital emergencies witnessed by these alumni after the course was 11.75%. The level of intervention among the alumni was high. The most efficient target population consisted of healthcare workers. Copyright © 2013 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  4. Generalized lineal models for the analysis of binary data from propagation experiments of Brazilian orchids

    Directory of Open Access Journals (Sweden)

    Freddy Mora

    2008-10-01

    Full Text Available This study aimed at applying the generalized linear models (GLM for the analysis of a germination experiment of Cattleya bicolor in which the response variable was binary. The purpose of this experiment was to assess the effects of the storage temperatures and culture mediums on the seed viability. The analyses of variance was also carried out either with or without the data transformation. All the statistical approaches indicated the importance of the storage temperature on the seed viability. But, the culture media and interaction effects were significant only by the GLM. Based on the GLM, the seeds stored at 10°C increased viability, in which the coconut medium achieved the best performance. The results emphasized the importance of adopting the GLM to improve the reliability in many situations where the response variable followed a non-normal distribution.A técnica de propagação in vitro é considerada efetiva para fins comerciais e de conservação de orquídeas. A metodologia de modelos lineares generalizados (MLG foi usada para analisar um experimento de germinação de Cattleya bicolor. O propósito do experimento foi avaliar os efeitos da temperatura de armazenamento e dos meios de cultivo sobre a germinação, cuja resposta foi considerada binária. Análise convencional com ou sem transformação de dados foram também realizados. Todas as abordagens estatísticas indicaram a importância da temperatura sobre a viabilidade das sementes. Entretanto, os efeitos de meios de cultivo e interação foram significativos apenas para MLG. As sementes armazenadas a 10°C incrementaram sua viabilidade, onde o meio a base de coco atingiu o melhor desempenho. Os resultados enfatizam a importância de adotar MLG, para melhorar a confiabilidade em situações onde a variável resposta segue uma distribuição distinta à normal.

  5. Dual-Tracer PET Using Generalized Factor Analysis of Dynamic Sequences

    Science.gov (United States)

    Fakhri, Georges El; Trott, Cathryn M.; Sitek, Arkadiusz; Bonab, Ali; Alpert, Nathaniel M.

    2013-01-01

    Purpose With single-photon emission computed tomography, simultaneous imaging of two physiological processes relies on discrimination of the energy of the emitted gamma rays, whereas the application of dual-tracer imaging to positron emission tomography (PET) imaging has been limited by the characteristic 511-keV emissions. Procedures To address this limitation, we developed a novel approach based on generalized factor analysis of dynamic sequences (GFADS) that exploits spatio-temporal differences between radiotracers and applied it to near-simultaneous imaging of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) (brain metabolism) and 11C-raclopride (D2) with simulated human data and experimental rhesus monkey data. We show theoretically and verify by simulation and measurement that GFADS can separate FDG and raclopride measurements that are made nearly simultaneously. Results The theoretical development shows that GFADS can decompose the studies at several levels: (1) It decomposes the FDG and raclopride study so that they can be analyzed as though they were obtained separately. (2) If additional physiologic/anatomic constraints can be imposed, further decomposition is possible. (3) For the example of raclopride, specific and nonspecific binding can be determined on a pixel-by-pixel basis. We found good agreement between the estimated GFADS factors and the simulated ground truth time activity curves (TACs), and between the GFADS factor images and the corresponding ground truth activity distributions with errors less than 7.3±1.3 %. Biases in estimation of specific D2 binding and relative metabolism activity were within 5.9±3.6 % compared to the ground truth values. We also evaluated our approach in simultaneous dual-isotope brain PET studies in a rhesus monkey and obtained accuracy of better than 6 % in a mid-striatal volume, for striatal activity estimation. Conclusions Dynamic image sequences acquired following near-simultaneous injection of two PET radiopharmaceuticals

  6. Pilot Designed Aircraft Displays in General Aviation: An Exploratory Study and Analysis

    Science.gov (United States)

    Conaway, Cody R.

    From 2001-2011, the General Aviation (GA) fatal accident rate remained unchanged (Duquette & Dorr, 2014) with an overall stagnant accident rate between 2004 and 2013. The leading cause, loss of control in flight (NTSB, 2015b & 2015c) due to pilot inability to recognize approach to stall/spin conditions (NTSB, 2015b & 2016b). In 2013, there were 1,224 GA accidents in the U.S., accounting for 94% of all U.S. aviation accidents and 90% of all U.S. aviation fatalities that year (NTSB, 2015c). Aviation entails multiple challenges for pilots related to task management, procedural errors, perceptual distortions, and cognitive discrepancies. While machine errors in airplanes have continued to decrease over the years, human error still has not (NTSB, 2013). A preliminary analysis of a PC-based, Garmin G1000 flight deck was conducted with 3 professional pilots. Analyses revealed increased task load, opportunities for distraction, confusing perceptual ques, and hindered cognitive performance. Complex usage problems were deeply ingrained in the functionality of the system, forcing pilots to use fallible work arounds, add unnecessary steps, and memorize knob turns or button pushes. Modern computing now has the potential to free GA cockpit designs from knobs, soft keys, or limited display options. Dynamic digital displays might include changes in instrumentation or menu structuring depending on the phase of flight. Airspeed indicators could increase in size to become more salient during landing, simultaneously highlighting pitch angle on Attitude Indicators and automatically decluttering unnecessary information for landing. Likewise, Angle-of-Attack indicators demonstrate a great safety and performance advantage for pilots (Duquette & Dorr, 2014; NTSB, 2015b & 2016b), an instrument typically found in military platforms and now the Icon A5, light-sport aircraft (Icon, 2016). How does the design of pilots' environment---the cockpit---further influence their efficiency and

  7. Productive whole-class discussions: A qualitative analysis of peer leader behaviors in general chemistry

    Science.gov (United States)

    Eckart, Teresa Mcclain

    The intention of this research was to describe behaviors and characteristics of General Chemistry I peer leaders using a pedagogical reform method referred to as Peer-led Guided Inquiry (PLGI), and to discuss the ways in which these peer leaders created productive whole-class discussions. This reform technique engaged students to work on guided inquiry activities while working cooperatively in small groups, led by undergraduate peer leaders. These sessions were video recorded and transcribed. The data was evaluated using grounded theory methods of analysis. This study examined the dialog between students and peer leaders, paying specific attention to question types and observed patterns of interactions. The research took shape by examining the kinds of questions asked by peer leaders and the purposes these questions served. In addition to looking at questions, different kinds of behaviors displayed by peer leaders during their small group sessions were also observed. A close examination of peer leader questions and behaviors aided in developing an answer to the overall research question regarding what factors are associated with productive whole-class discussions. Five major categories of peer leader behaviors evolved from the data and provided a means to compare and contrast productive whole-class discussions. While no category single-handedly determined if a discussion was good or bad, there was a tendency for peer leaders who exhibited positive traits in at least three of the following categories to have consistently better whole-class discussions: Procedural Practices, Supervisory Qualities, Questioning Techniques, Feedback/Responses, and Interpersonal Skills. Furthermore, each of the major categories is tied directly to Interpersonal, Communication, and Leadership skills and their interactions with each other. This study also addressed applications that each of these categories has on instructional practices and their need in peer leader training. In addition

  8. Generalized Frequency-Domain Correlator for Software GPS Receiver: Preliminary Test Results and Analysis (PREPRINT)

    National Research Council Canada - National Science Library

    Yang, Chun; Miller, Mikel; Nguyen, Thao; Akos, Dennis

    2006-01-01

    .... The use of a GFDC can offer several advantages. First, as a generalization of the FFT-implemented correlation with a block repetitive processing capability, it enables fast acquisition through simultaneous code delay and Doppler frequency search...

  9. Analysis of General Accounting Office Bid Protest Decisions on A-76 Studies

    National Research Council Canada - National Science Library

    Russial, Paul

    2003-01-01

    .... Historically, industry has successfully protested a high percentage of A-76 procurements. This thesis examines General Accounting Office A-76 bid protest decisions issued between 5 February 1996 and 23 December 2002...

  10. Semiquantitative analysis of interictal glucose metabolism between generalized epilepsy and localization related epilepsy

    International Nuclear Information System (INIS)

    Hikima, Akio; Mochizuki, Hiroyuki; Oriuchi, Noboru; Endo, Keigo; Morikawa, Akihiro

    2004-01-01

    Positron emission tomography (PET) with [ 18 F]fluoro-D-deoxyglucose (FDG) has been used to detect seizure foci and evaluate surgical resection with localization related epilepsies. However, few investigations have focused on generalized epilepsy in children. To reveal the pathophysiology of generalized epilepsy, we studied 11 patients with generalized epilepsy except West syndrome, and 11 patients with localization related epilepsy without organic disease. The FDG PET was performed by simultaneous emission and transmission scanning. We placed regions of interest (ROI) on bilateral frontal lobe, parietal lobe, occipital lobe, temporal lobe, basal ganglia, thalamus and cerebellum. Standardized uptake value (SUV) was measured and normalized to SUV of ipsilateral cerebellum. Then, we compared the data of generalized epilepsy to those of localization related epilepsy. FDG PET revealed significant interictal glucose hypometabolism in bilateral basal ganglia in generalized epilepsy compared to that in localization related epilepsy (right side: p=0.0095, left side: p=0.0256, Mann-Whitney test). No other region showed any significant difference (p>0.05) between the two groups. These findings indicate that the basal ganglia is involved in the outbreak of generalized seizures or is affected secondarily by the epileptogenicity itself. (author)

  11. A novel ergodic capacity analysis of diversity combining and multihop transmission systems over generalized composite fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2012-06-01

    Ergodic capacity is an important performance measure associated with reliable communication at the highest rate at which information can be sent over the channel with a negligible probability of error. In the shadow of this definition, diversity receivers (such as selection combining, equal-gain combining and maximal-ratio combining) and transmission techniques (such as cascaded fading channels, amplify-and-forward multihop transmission) are deployed in mitigating various performance impairing effects such as fading and shadowing in digital radio communication links. However, the exact analysis of ergodic capacity is in general not always possible for all of these forms of diversity receivers and transmission techniques over generalized composite fading environments due to it\\'s mathematical intractability. In the literature, published papers concerning the exact analysis of ergodic capacity have been therefore scarce (i.e., only [1] and [2]) when compared to those concerning the exact analysis of average symbol error probability. In addition, they are essentially targeting to the ergodic capacity of the maximal ratio combining diversity receivers and are not readily applicable to the capacity analysis of the other diversity combiners / transmission techniques. In this paper, we propose a novel moment generating function-based approach for the exact ergodic capacity analysis of both diversity receivers and transmission techniques over generalized composite fading environments. As such, we demonstrate how to simultaneously treat the ergodic capacity analysis of all forms of both diversity receivers and multihop transmission techniques. © 2012 IEEE.

  12. The General Factor of Personality: A meta-analysis of Big Five intercorrelations and a criterion-related validity study

    NARCIS (Netherlands)

    van der Linden, D.; te Nijenhuis, J.; Bakker, A.B.

    2010-01-01

    Recently, it has been proposed that a General Factor of Personality (GFP) occupies the top of the hierarchical personality structure. We present a meta-analysis (K = 212, total N = 144,117) on the intercorrelations among the Big Five personality factors (Openness, Conscientiousness, Extraversion,

  13. The Essences of Culinary Arts Students' Lived Experience of General Education Online Learning: An Interpretive Phenomenological Analysis

    Science.gov (United States)

    Keovilay, Sisavath

    2015-01-01

    This phenomenological research study explored the lived experiences of culinary arts students learning general education online while enrolled in a face-to-face (f2f) culinary arts class. This research used Interpretative Phenomenological Analysis (IPA) to analyze how culinary arts students, in a not-for-profit Florida University, made sense of…

  14. General Growth Mixture Analysis of Adolescents' Developmental Trajectories of Anxiety: The Impact of Untested Invariance Assumptions on Substantive Interpretations

    Science.gov (United States)

    Morin, Alexandre J. S.; Maiano, Christophe; Nagengast, Benjamin; Marsh, Herbert W.; Morizot, Julien; Janosz, Michel

    2011-01-01

    Substantively, this study investigates potential heterogeneity in the developmental trajectories of anxiety in adolescence. Methodologically, this study demonstrates the usefulness of general growth mixture analysis (GGMA) in addressing these issues and illustrates the impact of untested invariance assumptions on substantive interpretations. This…

  15. Analysis of Cine-Psychometric Visual Memory Data by the Tucker Generalized Learning Curve Method: Final Report.

    Science.gov (United States)

    Reid, J. C.; Seibert, Warren F.

    The analysis of previously obtained data concerning short-term visual memory and cognition by a method suggested by Tucker is proposed. Although interesting individual differences undoubtedly exist in people's ability and capacity to process short-term visual information, studies have not generally examined these differences. In fact, conventional…

  16. Distributional Assumptions in Educational Assessments Analysis: Normal Distributions versus Generalized Beta Distribution in Modeling the Phenomenon of Learning

    Science.gov (United States)

    Campos, Jose Alejandro Gonzalez; Moraga, Paulina Saavedra; Del Pozo, Manuel Freire

    2013-01-01

    This paper introduces the generalized beta (GB) model as a new modeling tool in the educational assessment area and evaluation analysis, specifically. Unlike normal model, GB model allows us to capture some real characteristics of data and it is an important tool for understanding the phenomenon of learning. This paper develops a contrast with the…

  17. GENOVA: a generalized perturbation theory program for various applications to CANDU core physics analysis (II) - a user's manual

    International Nuclear Information System (INIS)

    Kim, Do Heon; Choi, Hang Bok

    2001-03-01

    A user's guide for GENOVA, a GENeralized perturbation theory (GPT)-based Optimization and uncertainty analysis program for Canada deuterium uranium (CANDU) physics VAriables, was prepared. The program was developed under the framework of CANDU physics design and analysis code RFSP. The generalized perturbation method was implemented in GENOVA to estimate the zone controller unit (ZCU) level upon refueling operation and calculate various sensitivity coefficients for fuel management study and uncertainty analyses, respectively. This documentation contains descriptions and directions of four major modules of GENOVA such as ADJOINT, GADJINT, PERTURB, and PERTXS so that it can be used as a practical guide for GENOVA users. This documentation includes sample inputs for the ZCU level estimation and sensitivity coefficient calculation, which are the main application of GENOVA. The GENOVA can be used as a supplementary tool of the current CANDU physics design code for advanced CANDU core analysis and fuel development

  18. An Analysis of Metaphors Used by Students to Describe Energy in an Interdisciplinary General Science Course

    Science.gov (United States)

    Lancor, Rachael

    2015-01-01

    The meaning of the term energy varies widely in scientific and colloquial discourse. Teasing apart the different connotations of the term can be especially challenging for non-science majors. In this study, undergraduate students taking an interdisciplinary, general science course (n?=?49) were asked to explain the role of energy in five contexts:…

  19. Corporate Tax Policy and Unemployment in Europe: An Applied General Equilibrium Analysis

    NARCIS (Netherlands)

    L.J.H. Bettendorf (Leon); A. van der Horst; R.A. de Mooij (Ruud)

    2007-01-01

    textabstractThis paper analyzes the impact of corporate taxes on structural unemployment, using an applied general equilibrium model for the European Union. We find that the unemployment and welfare effects of corporate taxes differ considerably among European countries. The magnitude of these

  20. Analysis of a generalized shortest queue system by flexible bound models

    NARCIS (Netherlands)

    van Houtum, G.J.; Klein Haneveld, W.K.; Vrieze, O.J.; Kallenberg, L.C.M.

    1997-01-01

    Motivated by a practical situation for the production/assembly of printed circuit boards, we study a generalized shortest queue system. This system consists of parallel servers, which all have their own queue. The system serves several types of jobs, which arrive according to Poisson processes.

  1. Parent Ratings of ADHD Symptoms: Generalized Partial Credit Model Analysis of Differential Item Functioning across Gender

    Science.gov (United States)

    Gomez, Rapson

    2012-01-01

    Objective: Generalized partial credit model, which is based on item response theory (IRT), was used to test differential item functioning (DIF) for the "Diagnostic and Statistical Manual of Mental Disorders" (4th ed.), inattention (IA), and hyperactivity/impulsivity (HI) symptoms across boys and girls. Method: To accomplish this, parents completed…

  2. WAGEM: an applied general equilibrium model for agricultural and environmental policy analysis.

    NARCIS (Netherlands)

    Komen, M.H.C.; Peerlings, J.H.M.

    1996-01-01

    Agricultural and environmental policy changes have potentially large effects on Dutch agriculture and economy as a whole. The effects could be on inter-industry transactions, factor demand, income, trade, and environmental quality. The clear structure and flexibility make applied general equilibrium

  3. A Measurement Invariance Analysis of the General Self-Efficacy Scale on Two Different Cultures

    Science.gov (United States)

    Teo, Timothy; Kam, Chester

    2014-01-01

    The 10-item General Self-Efficacy Scale (GSES) was developed to assess an individual's beliefs to cope with a variety of situations in life. Despite the GSES being used in numerous research from researchers in different countries and presented in different languages, little is known about the use of its validity in an Asian culture. The aim of the…

  4. An Analysis of Undergraduate General Chemistry Students' Misconceptions of the Submicroscopic Level of Precipitation Reactions

    Science.gov (United States)

    Kelly, Resa M.; Barrera, Juliet H.; Mohamed, Saheed C.

    2010-01-01

    This study examined how 21 college-level general chemistry students, who had received instruction that emphasized the symbolic level of ionic equations, explained their submicroscopic-level understanding of precipitation reactions. Students' explanations expressed through drawings and semistructured interviews revealed the nature of the…

  5. Integrating Biology into the General Chemistry Laboratory: Fluorometric Analysis of Chlorophyll "a"

    Science.gov (United States)

    Wesolowski, Meredith C.

    2014-01-01

    A laboratory experiment that introduces fluorometry of chlorophyll "a" at the general chemistry level is described. The use of thin-layer chromatography to isolate chlorophyll "a" from spirulina and leaf matter enables quantification of small amounts of chlorophyll "a" via fluorometry. Student results were reasonably…

  6. Awareness, Analysis, and Action: Curricular Alignment for Student Success in General Chemistry

    Science.gov (United States)

    Jewitt, Sarah; Sutphin, Kathy; Gierasch, Tiffany; Hamilton, Pauline; Lilly, Kathleen; Miller, Kristine; Newlin, Donald; Pires, Richard; Sherer, Maureen; LaCourse, William R.

    2018-01-01

    This article examines the ways that a shared faculty experience across five partner institutions led to a deep awareness of the curriculum and pedagogy of general chemistry coursework, and ultimately, to a collaborative action plan for student success. The team identified key differences and similarities in course content and instructional…

  7. Regional disaster impact analysis: comparing Input-Output and Computable General Equilibrium models

    NARCIS (Netherlands)

    Koks, E.E.; Carrera, L.; Jonkeren, O.; Aerts, J.C.J.H.; Husby, T.G.; Thissen, M.; Standardi, G.; Mysiak, J.

    2016-01-01

    A variety of models have been applied to assess the economic losses of disasters, of which the most common ones are input-output (IO) and computable general equilibrium (CGE) models. In addition, an increasing number of scholars have developed hybrid approaches: one that combines both or either of

  8. Worst case analysis for a general class of on-line lot-sizing heuristics.

    NARCIS (Netherlands)

    W. van den Heuvel (Wilco); A.P.M. Wagelmans (Albert)

    2007-01-01

    textabstractIn this paper we analyze the worst case performance of heuristics for the classical economic lot-sizing problem with time-invariant cost parameters. We consider a general class of on-line heuristics that is often applied in a rolling horizon environment. We develop a procedure to

  9. Macroeconomic effects of CO2 emission limits : A computable general equilibrium analysis for China

    NARCIS (Netherlands)

    Zhang, ZX

    The study analyzes the macroeconomic effects of limiting China's CO2 emissions by using a time-recursive dynamic computable general equilibrium (CGE) model of the Chinese economy. The baseline scenario for the Chinese economy over the period to 2010 is first developed under a set of assumptions

  10. Usability of teleshopping systems by young and older adults : General performance, task analysis and subjective evaluation

    NARCIS (Netherlands)

    de Raad, KJE; Dekker, MR; Sikken, J.A.; den Brinker, P.B.L.M.; Beek, PJ; Brand, AN; Maarse, FJ; Mulder, LJM

    1999-01-01

    Older people generally experience more difficulty learning to work with new information technologies than younger people. This may be partly due to age-related impairments of memory and information processing. To determine which aspects of user interfaces pose too high demands on order users, an

  11. Analysis of Generalized Mach–Zehnder Interferometers for Variable-Ratio Power Splitting and Optimized Switching

    NARCIS (Netherlands)

    Lagali, N.S.; Paiam, Mohammad R.; MacDonald, Robert I.; Worhoff, Kerstin; Driessen, A.

    1999-01-01

    The nonideal integrated optical N x N generalized Mach–Zehnder interferometer (GMZI) employing multimode interference (MMI) couplers is analyzed using transfer matrix techniques. Deviations in the phase relations and the power splitting ratio of the MMI couplers are included in the theory, along

  12. Psychometrical Assessment and Item Analysis of the General Health Questionnaire in Victims of Terrorism

    Science.gov (United States)

    Delgado-Gomez, David; Lopez-Castroman, Jorge; de Leon-Martinez, Victoria; Baca-Garcia, Enrique; Cabanas-Arrate, Maria Luisa; Sanchez-Gonzalez, Antonio; Aguado, David

    2013-01-01

    There is a need to assess the psychiatric morbidity that appears as a consequence of terrorist attacks. The General Health Questionnaire (GHQ) has been used to this end, but its psychometric properties have never been evaluated in a population affected by terrorism. A sample of 891 participants included 162 direct victims of terrorist attacks and…

  13. Distribution theory and transform analysis an introduction to generalized functions, with applications

    CERN Document Server

    Zemanian, AH

    2010-01-01

    This well-known text provides a relatively elementary introduction to distribution theory and describes generalized Fourier and Laplace transformations and their applications to integrodifferential equations, difference equations, and passive systems. Suitable for a graduate course for engineering and science students or for an advanced undergraduate course for mathematics majors. 1965 edition.

  14. Modeling containment of large wildfires using generalized linear mixed-model analysis

    Science.gov (United States)

    Mark Finney; Isaac C. Grenfell; Charles W. McHugh

    2009-01-01

    Billions of dollars are spent annually in the United States to contain large wildland fires, but the factors contributing to suppression success remain poorly understood. We used a regression model (generalized linear mixed-model) to model containment probability of individual fires, assuming that containment was a repeated-measures problem (fixed effect) and...

  15. Asthma prevalence in Olympic summer athletes and the general population: an analysis of three European countries.

    NARCIS (Netherlands)

    Burns, J.; Mason, C.; Mueller, N.; Ohlander, J.; Zock, J.P.; Drobnic, F.; Wolfarth, B.; Heinrich, J.; Omenass, E.; Stensrud, T.; Nowak, D.; Radon, K.

    2015-01-01

    Background: Some studies have shown a higher prevalence of asthma in elite athletes as compared to the general population. It is inconclusive to what extent certain sport categories are especially affected. The present study offered a unique opportunity to assess these differences in asthma

  16. Semi-analytical stochastic analysis of the generalized van der Pol system

    Czech Academy of Sciences Publication Activity Database

    Náprstek, Jiří; Fischer, Cyril

    (2018) ISSN 1802-680X R&D Projects: GA ČR(CZ) GA15-01035S Institutional support: RVO:68378297 Keywords : stochastic stability * generalized van der Pol system * stochastic averaging * limit cycles Subject RIV: JM - Building Engineering OBOR OECD: Construction engineering, Municipal and structural engineering https://www.kme.zcu.cz/acm/acm/article/view/407

  17. An analysis of acute admissions to a general hospital psychiatric unit

    African Journals Online (AJOL)

    Rapid turnover of patients in a general hospital psychiatric unit demands stabilization and discharge as soon as possible. It is likely that patients are being prematurely discharged because of this pressure. Aim: The study sought to analyse admissions to an acute psychiatric unit with a view to determining the demographic ...

  18. Stability analysis of a general age-dependent vaccination model of a vertically transmitted disease

    International Nuclear Information System (INIS)

    El Doma, M.

    1995-07-01

    An SIR epidemic model of a general age-dependent vaccination of a vertically as well as horizontally transmitted disease is investigated when the population is in steady state and the fertility, mortality and removal rates depends on age. We determine the steady states and examine their stabilities. (author). 24 refs

  19. Stool management systems for preventing environmental spread of Clostridium difficile: a comparative trial.

    Science.gov (United States)

    Gray, Mikel; Omar, Amin; Buziak, Brenton

    2014-01-01

    The purpose of this study was to compare contamination of the immediate environment with Clostridium difficile spores and vegetative cells from 2 stool management systems over a period of 30 days in a controlled laboratory setting. In vitro, comparison trial. Two stool management systems were compared over a 30-day period in a controlled laboratory setting. Sixteen systems were filled with sterile loose canine stool inoculated with 10 colony-forming units (CFUs) per milliliter of C difficile; specially prepared culture media were used to detect C difficile contamination on various surfaces of the device and in the immediate environment. Containment bags were changed daily and devices were refilled with inoculated stool to more closely imitate use in the clinical setting. A dichotomous outcome variable (growth vs no growth) was used to analyze contamination on a daily basis via the generalized estimating equation; devices were also compared on days 3, 10, 20, and 30 by measuring CFUs per device surface. Logistic regression analysis was used to analyze growth over time. When observations showed no growth, the Cochran-Mantel Haenszel test was used to compare study devices. Analysis revealed that 20.8% of anterior surfaces of the collection bags for device 1 were contaminated versus 83.9% of collection bags for device 2 (P < .001). Comparison of the tubing/hub interface resulted in similar findings; 20.8% of device 1 group were contaminated versus 86.3% of device 2 group (P < .001). Analysis of an absorbent pad placed under the device during daily changes found that 0.5% of device 1 were contaminated versus 38.1% of pads placed under device 2 (P < .001). Findings from this in vitro study show that stool management systems can limit or prevent environmental contamination of C difficile. Results also reveal significant differences in the 2 systems tested; we hypothesize that these differences are attributable to the interface between the tubing and collection bag, the

  20. Pharmacist services provided in general practice clinics: a systematic review and meta-analysis.

    Science.gov (United States)

    Tan, Edwin C K; Stewart, Kay; Elliott, Rohan A; George, Johnson

    2014-01-01

    Integration of pharmacists into primary care general practice clinics has the potential to improve interdisciplinary teamwork and patient care; however this practice is not widespread. The aim of this study was to review the effectiveness of clinical pharmacist services delivered in primary care general practice clinics. A systematic review of English language randomized controlled trials cited in the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and International Pharmaceutical Abstracts was conducted. Studies were included if pharmacists had a regular and ongoing relationship with the clinic; delivered an intervention aimed at optimizing prescribing for, and/or medication use by, clinic patients; and were physically present within the clinic for all or part of the intervention, or for communication with staff. The search generated 1484 articles. After removal of duplicates and screening of titles and abstracts against inclusion criteria, 131 articles remained. A total of 38 studies were included in the review and assessed for quality. Seventeen studies had common endpoints (blood pressure, glycosylated hemoglobin, cholesterol and/or Framingham risk score) and were included in meta-analyses. Twenty-nine of the 38 studies recruited patients with specific medical conditions, most commonly cardiovascular disease (15 studies) and/or diabetes (9 studies). The remaining 9 studies recruited patients at general risk of medication misadventure. Pharmacist interventions usually involved medication review (86.8%), with or without other activities delivered collaboratively with the general practitioner (family physician). Positive effects on primary outcomes related to medication use or clinical outcomes were reported in 19 studies, mixed effects in six studies, and no effect in 13 studies. The results of meta-analyses favored the pharmacist intervention, with significant improvements in blood pressure, glycosylated hemoglobin, cholesterol and Framingham

  1. Analysis of noise-induced transitions in a generalized logistic model with delay near Neimark–Sacker bifurcation

    International Nuclear Information System (INIS)

    Bashkirtseva, Irina; Ekaterinchuk, Ekaterina; Ryashko, Lev

    2017-01-01

    We consider an effect of random disturbances on the generalized logistic model with delay in mono- and bistable regimes near Neimark–Sacker bifurcation. Noise-induced transitions between coexisting attractors, and between separate parts of the unique attractor, are studied. We suggest a semi-analytical approach that combines a geometric analysis of the mutual arrangement of attractors, their basins of attraction, and corresponding confidence domains found by the stochastic sensitivity functions technique. Constructive abilities of this approach are demonstrated for the generalized logistic model with delay. (paper)

  2. Lie symmetry analysis and reductions of a two-dimensional integrable generalization of the Camassa-Holm equation

    Science.gov (United States)

    Kraenkel, R. A.; Senthilvelan, M.; Zenchuk, A. I.

    2000-08-01

    In this Letter we investigate Lie symmetries of a (2+1)-dimensional integrable generalization of the Camassa-Holm (CH) equation. Through the similarity reductions we obtain four different (1+1)-dimensional systems of partial differential equations in which one of them turns out to be a (1+1)-dimensional CH equation. We establish their integrability by providing the Lax pair for all of them. Further, we present a brief analysis for some types of particular solutions which include the cuspon, peakon and soliton solutions for the two-dimensional generalization of the CH equation.

  3. Analysis of noise-induced transitions in a generalized logistic model with delay near Neimark-Sacker bifurcation

    Science.gov (United States)

    Bashkirtseva, Irina; Ekaterinchuk, Ekaterina; Ryashko, Lev

    2017-07-01

    We consider an effect of random disturbances on the generalized logistic model with delay in mono- and bistable regimes near Neimark-Sacker bifurcation. Noise-induced transitions between coexisting attractors, and between separate parts of the unique attractor, are studied. We suggest a semi-analytical approach that combines a geometric analysis of the mutual arrangement of attractors, their basins of attraction, and corresponding confidence domains found by the stochastic sensitivity functions technique. Constructive abilities of this approach are demonstrated for the generalized logistic model with delay.

  4. A more general model for the analysis of the rock slope stability

    Indian Academy of Sciences (India)

    Because of the numerous problems related to the rock slope stability the above assumption is satisfied and the shear strength characteristics of intact rock have taken part in the analysis. The analysis presented here gives a better concept, view, and idea of understanding the physical nature of rock slopes and includes ...

  5. A more general model for the analysis of the rock slope stability

    Indian Academy of Sciences (India)

    characteristics of intact rock have taken part in the analysis. The analysis presented here gives a better concept, view, and idea of understanding the physical nature of rock slopes and includes more parameters governing the stability of the potential failure zone. Keywords. Wedge failure; slope stability; trace length; joint set; ...

  6. Interpreted consultations as 'business as usual'? An analysis of organisational routines in general practices.

    Science.gov (United States)

    Greenhalgh, Trisha; Voisey, Christopher; Robb, Nadia

    2007-09-01

    UK general practices operate in an environment of high linguistic diversity, because of recent large-scale immigration and of the NHS's commitment to provide a professional interpreter to any patient if needed. Much activity in general practice is co-ordinated and patterned into organisational routines (defined as repeated patterns of interdependent actions, involving multiple actors, bound by rules and customs) that tend to be stable and to persist. If we want to understand how general practices are responding to pressures to develop new routines, such as interpreted consultations, we need to understand how existing organisational routines change. This will then help us to address a second question, which is how the interpreted consultation itself is being enacted and changing as it becomes routinised (or not) in everyday general practice. In seeking answers to these two questions, we undertook a qualitative study of narratives of interpreted primary care consultations in three London boroughs with large minority ethnic populations. In 69 individual interviews and two focus groups, we sought accounts of interpreted consultations from service users, professional interpreters, family member interpreters, general practitioners, practice nurses, receptionists, and practice managers. We asked participants to tell us both positive and negative stories of their experiences. We analysed these data by searching for instances of concepts relating to the organisational routine, the meaning of the interpreted consultation to the practice, and the sociology of medical work. Our findings identified a number of general properties of the interpreted consultation as an organisational routine, including the wide variation in the form of adoption, the stability of the routine, the adaptability of the routine, and the strength of the routine. Our second key finding was that this variation could be partly explained by characteristics of the practice as an organisation, especially

  7. A general model for techno-economic analysis of CSP plants with thermochemical energy storage systems

    Science.gov (United States)

    Peng, Xinyue; Maravelias, Christos T.; Root, Thatcher W.

    2017-06-01

    Thermochemical energy storage (TCES), with high energy density and wide operating temperature range, presents a potential solution for CSP plant energy storage. We develop a general optimization based process model for CSP plants employing a wide range of TCES systems which allows us to assess the plant economic feasibility and energy efficiency. The proposed model is applied to a 100 MW CSP plant employing ammonia or methane TCES systems. The methane TCES system with underground gas storage appears to be the most promising option, achieving a 14% LCOE reduction over the current two-tank molten-salt CSP plants. For general TCES systems, gas storage is identified as the main cost driver, while the main energy driver is the compressor electricity consumption. The impacts of separation and different reaction parameters are also analyzed. This study demonstrates that the realization of TCES systems for CSP plants is contingent upon low storage cost and a reversible reaction with proper reaction properties.

  8. The response analysis of fractional-order stochastic system via generalized cell mapping method

    Science.gov (United States)

    Wang, Liang; Xue, Lili; Sun, Chunyan; Yue, Xiaole; Xu, Wei

    2018-01-01

    This paper is concerned with the response of a fractional-order stochastic system. The short memory principle is introduced to ensure that the response of the system is a Markov process. The generalized cell mapping method is applied to display the global dynamics of the noise-free system, such as attractors, basins of attraction, basin boundary, saddle, and invariant manifolds. The stochastic generalized cell mapping method is employed to obtain the evolutionary process of probability density functions of the response. The fractional-order ϕ 6 oscillator and the fractional-order smooth and discontinuous oscillator are taken as examples to give the implementations of our strategies. Studies have shown that the evolutionary direction of the probability density function of the fractional-order stochastic system is consistent with the unstable manifold. The effectiveness of the method is confirmed using Monte Carlo results.

  9. A general framework for global asymptotic stability analysis of delayed neural networks based on LMI approach

    International Nuclear Information System (INIS)

    Cao Jinde; Ho, Daniel W.C.

    2005-01-01

    In this paper, global asymptotic stability is discussed for neural networks with time-varying delay. Several new criteria in matrix inequality form are given to ascertain the uniqueness and global asymptotic stability of equilibrium point for neural networks with time-varying delay based on Lyapunov method and Linear Matrix Inequality (LMI) technique. The proposed LMI approach has the advantage of considering the difference of neuronal excitatory and inhibitory efforts, which is also computationally efficient as it can be solved numerically using recently developed interior-point algorithm. In addition, the proposed results generalize and improve previous works. The obtained criteria also combine two existing conditions into one generalized condition in matrix form. An illustrative example is also given to demonstrate the effectiveness of the proposed results

  10. Analysis and Lessons from General Galvez’s West Florida Campaign during the American Revolutionary War

    Science.gov (United States)

    2015-06-12

    España y la Independencia de Estados Unidos by Thomas E. Chavez, or the classic España Ante La Independencia De Los Estados Unidos by Juan F... Unidos (Madrid: Santillana Ediciones Generales, 2006); Juan F. Utrilla, España Ante La Independencia De Los Estados Unidos , 2nd ed. (Lérida...Independencia De Los Estados Unidos (Barcelona: Ediciones Del Serbal, 1986); Pablo E. Victoria, España Contraataca: Relato Sobre La Derrota Del

  11. Program CONTRAST--A general program for the analysis of several survival or recovery rate estimates

    Science.gov (United States)

    Hines, J.E.; Sauer, J.R.

    1989-01-01

    This manual describes the use of program CONTRAST, which implements a generalized procedure for the comparison of several rate estimates. This method can be used to test both simple and composite hypotheses about rate estimates, and we discuss its application to multiple comparisons of survival rate estimates. Several examples of the use of program CONTRAST are presented. Program CONTRAST will run on IBM-cimpatible computers, and requires estimates of the rates to be tested, along with associated variance and covariance estimates.

  12. Impacts of climate change for Swiss winter and summer tourism: a general equilibrium analysis

    OpenAIRE

    Thurm, Boris; Vielle, Marc; Vöhringer, Frank

    2017-01-01

    Tourism could be greatly affected by climate change due to its strong dependence on weather. In Switzerland, the sector represents an appreciable share of the economy. Thus, studying climate effects on tourism is necessary for developing adequate adaptation strategies. While most of the studies focused on winter tourism, we investigate the climate change impacts on both winter and summer tourism in Switzerland. Using a computable general equilibrium (CGE) model, we simulate the impacts of tem...

  13. Oil prices, capital mobility and oil importers: a general equilibrium macro analysis

    OpenAIRE

    Arturo González Romero

    1987-01-01

    The aim of this paper is to explore the general macro characteristics of the trading economies that can help us understand the world economy response after OPEC I and OPEC II in terms of the evolution of the North-South terms of trade, rates of profit and output levels. Therefore, we support the view of the world economy in a three regional setting, North-South-OPEC.

  14. Message Embedded Chaotic Masking Synchronization Scheme Based on the Generalized Lorenz System and Its Security Analysis

    Czech Academy of Sciences Publication Activity Database

    Čelikovský, Sergej; Lynnyk, Volodymyr

    2016-01-01

    Roč. 26, č. 8 (2016), 1650140-1-1650140-15 ISSN 0218-1274 R&D Projects: GA ČR GA13-20433S Institutional support: RVO:67985556 Keywords : Chaotic masking * generalized Lorenz system * message embedded synchronization Subject RIV: BC - Control System s Theory Impact factor: 1.329, year: 2016 http://library.utia.cas.cz/separaty/2016/TR/celikovsky-0461536.pdf

  15. Numerical General Equilibrium Analysis of China's Impacts from Possible Mega Trade Deals

    OpenAIRE

    Chunding Li; Jing Wang; John Whalley

    2014-01-01

    This paper explores the potential impacts on both China and other major countries of possible mega trade deals. These include the Trans-Pacific Partnership (TPP), the Regional Comprehensive Economic Partnership (RCEP), and various blocked deals. We use a numerical 13-country global general equilibrium model with trade costs to investigate both tariff and non-tariff effects, and include inside money to endogenously determine imports on the trade imbalance. Trade costs are calculated using a me...

  16. Promoting investment under international capital mobility: An intertemporal general equilibrium analysis

    OpenAIRE

    Bovenberg, A.L.; Goulder, L.H.

    1993-01-01

    This paper uses a dynamic computable general equilibrium model to compare, in an economy open to international capital flows, the effects of two U.S. policies intended to promote domestic capital formation. The two policies -- the introduction of an investment tax credit (ITC) and a reduction in the statutory corporate income tax rate -- differ in their treatment of old (existing) and new capital. The model features adjustment dynamics, intertemporal optimization by U.S. and foreign household...

  17. General analysis of inductive sensor based systems for non destructive testing

    OpenAIRE

    Dufour, Isabelle; Busawon, Moolraj; Premel, Denis; Placko, Dominique

    1994-01-01

    This paper presents a general view of the Non Destructive Testing (NDT) systems based on the use of inductive sensors where the potential users are likely to be more and more numerous. We describe the different phases of their conception. Firstly, we analyse the physical interaction between the sensor and the specimen material by the use of an enlarged concept of electrical images. The instrumentation problem is next reviewed by analysing the signals which are supplied by these sensors, and b...

  18. Analysis of a general age-dependent vaccination model for a vertically transmitted disease

    International Nuclear Information System (INIS)

    El Doma, M.

    1995-05-01

    A SIR epidemic model of a general age-dependent vaccination for a vertically as well as horizontally transmitted disease is investigated when the total population is time dependent, and fertility, mortality and removal rates depend on age. We establish the existence and the uniqueness of the solution and obtain the asymptotic behaviour for the solution. For the steady state solution a critical vaccination coverage which will eventually eradicate the disease is determined. (author). 18 refs

  19. Discharge Fee Policy Analysis: A Computable General Equilibrium (CGE) Model of Water Resources and Water Environments

    OpenAIRE

    Guohua Fang; Ting Wang; Xinyi Si; Xin Wen; Yu Liu

    2016-01-01

    To alleviate increasingly serious water pollution and shortages in developing countries, various kinds of policies have been implemented by local governments. It is vital to quantify and evaluate the performance and potential economic impacts of these policies. This study develops a Computable General Equilibrium (CGE) model to simulate the regional economic and environmental effects of discharge fees. Firstly, water resources and water environment factors are separated from the input and out...

  20. Payroll Taxes and the Labor Market: A Computable General Equilibrium Analysis

    OpenAIRE

    Gustavo Hernández

    2012-01-01

    This study uses a computable general equilibrium model to analyze the effects of eliminating Colombia’s parafiscal taxes, which finance social programs. In the model, these are substituted by alternative financing sources: VAT, indirect taxes or taxes on capital. The results show that elimination of parafiscal taxes produces a one percentage point decrease in the unemployment rate, as long as these are not substituted by other taxes. However, when other taxes are substituted for parafiscal ta...

  1. Analysis on the Implementation of Nutrition Services in Tugurejo General Hospital Semarang

    OpenAIRE

    Dewi, Emy Shinta; Kartasurya, Martha Irene; Sriatmi, Ayun

    2015-01-01

    Nutrition was an important factor for patient care and cure. Results of an evaluation by nutritionalresearch and development unit of Tugurejo district general hospital (RSUD) in 2011 indicated thatfood remains of patient were still below the minimal standard of service. Objective of this study wasto analyze the implementation of nutritional service in the RSUD Tugurejo Semarang.This was a qualitative study with 4 nutritionists, 8 cook assistants, and 8 waitresses as maininformants. Triangulat...

  2. ABOUT THE SYSTEM ANALYSIS OF UNEMPLOYMENT OF YOUTH: GENERAL TASKS AND PRIVATE MODELS OF MARKET INDICATORS

    Directory of Open Access Journals (Sweden)

    Natalia V. Kontsevaya

    2016-01-01

    Full Text Available In this work attempt of system approach to the analysis of labor market of youth is made, the place and a role of youth labor exchange are dened, opportunities and methods of state regulation are opened, contradictions in the analysis of the main market indicators are designated.Within system approach to the analysis of dynamics of market processes modeling of the main indicators of labor market in regional scale is shown.This approach can be useful when developing effective and economically reasonable mechanisms of employment of youth, both at the level of regional services of employment, and in the state scale

  3. Statistical power analysis a simple and general model for traditional and modern hypothesis tests

    CERN Document Server

    Murphy, Kevin R; Wolach, Allen

    2014-01-01

    Noted for its accessible approach, this text applies the latest approaches of power analysis to both null hypothesis and minimum-effect testing using the same basic unified model. Through the use of a few simple procedures and examples, the authors show readers with little expertise in statistical analysis how to obtain the values needed to carry out the power analysis for their research. Illustrations of how these analyses work and how they can be used to choose the appropriate criterion for defining statistically significant outcomes are sprinkled throughout. The book presents a simple and g

  4. Caffeine Consumption and General Health in Secondary School Children: A Cross-sectional and Longitudinal Analysis

    Directory of Open Access Journals (Sweden)

    Gareth Richards

    2016-11-01

    Full Text Available Although caffeine is sometimes associated with beneficial effects in adults, concern has been expressed that the substance may be dangerous if intake is too high, and particularly so when used by children and adolescents. For this reason, the current study examined data from the Cornish Academies Project to determine whether caffeine consumption in secondary school children was related to responses to a single-item measure of general health. Because two cross-sections of data were available, these relationships were explored both cross-sectionally and longitudinally. High caffeine consumption (i.e. >1000 mg/w was associated with low general health in both cross-sections of data. However, after controlling for additional aspects of diet, demography, and lifestyle, this effect only remained significant at the latter time-point. Further to this, null findings from cross-lag and change-score analyses suggested that caffeine and general health were unlikely to be causally linked in this sample. However, due to methodological limitations, such as the two cross-sections of data being collected only six months apart, it is suggested that further longitudinal and intervention studies are required in order for firm conclusions to be drawn.

  5. A Comparative Analysis of a Community and General Sample of Lesbian, Gay, and Bisexual Individuals.

    Science.gov (United States)

    Kuyper, Lisette; Fernee, Henk; Keuzenkamp, Saskia

    2016-04-01

    Samples recruited at lesbian, gay, and bisexual (LGB) venues have certain benefits, but a major drawback is that these samples are prone to bias as they only contain LGB participants who visit such venues. Empirical data with regard to the potential differences between LGB community samples and LGB general samples may shed some light on the generalizability of research findings from convenience samples recruited through LGB venues. The current study attempted to contribute to existing knowledge by examining differences in social demographics, sexual orientation, minority stress, and mental health between a convenience sample recruited at LGB venues ("community sample," N = 3,403) and an LGB sample recruited from a general research panel in the Netherlands ("panel sample," N = 1,000). Various differences were found. In general, community participants were younger, reported a more exclusive same-sex sexual orientation, were more open about their sexual orientation, had lower levels of internalized homonegativity, and encountered more negative social reactions on their LGB status. They also reported higher levels of psychological distress and suicidality. The Nagelkerke R (2) of the analyses (which were adjusted for sociodemographic differences) ranged from .08 (suicide plans among men) to .27 (sexual attraction among women). However, while the estimates of sociodemographics, sexual orientation, minority stress, and mental well-being differed, the relationships between these constructs were comparable in both samples. Implications and suggestions for future studies are discussed.

  6. Cause analysis, prevention, and treatment of postoperative restlessness after general anesthesia in children with cleft palate.

    Science.gov (United States)

    Xu, Hao; Mei, Xiao-Peng; Xu, Li-Xian

    2017-03-01

    Cleft palate is one of the most common congenital malformations of the oral and maxillofacial region, with an incidence rate of around 0.1%. Early surgical repair is the only method for treatment of a cleft lip and palate. However, because of the use of inhalation anesthesia in children and the physiological characteristics of the cleft palate itself combined with the particularities of cleft palate surgery, the incidence rate of postoperative emergence agitation (EA) in cleft palate surgery is significantly higher than in other types of interventions. The exact mechanism of EA is still unclear. Although restlessness after general anesthesia in children with cleft palate is self-limiting, its effects should be considered by clinicians. In this paper, the related literature on restlessness after surgery involving general anesthesia in recent years is summarized. This paper focuses on induction factors as well as prevention and treatment of postoperative restlessness in children with cleft palate after general anesthesia. The corresponding countermeasures to guide clinical practice are also presented in this paper.

  7. Quasi-likelihood generalized linear regression analysis of fatality risk data.

    Science.gov (United States)

    2009-01-01

    Transportation-related fatality risks is a function of many interacting human, vehicle, and environmental factors. Statistically valid analysis of such data is challenged both by the complexity of plausible structural models relating fatality rates t...

  8. Determinations of Carbon Dioxide by Titration: New Experiments for General, Physical, and Quantitative Analysis Courses.

    Science.gov (United States)

    Crossno, S. K.; And Others

    1996-01-01

    Presents experiments involving the analysis of commercial products such as carbonated beverages and antacids that illustrate the principles of acid-base reactions and present interesting problems in stoichiometry for students. (JRH)

  9. The GEMPAK Barnes interactive objective map analysis scheme. [General Meteorological Software Package

    Science.gov (United States)

    Koch, S. E.; Kocin, P. J.; Desjardins, M.

    1983-01-01

    The analysis scheme and meteorological applications of the GEMPAK data analysis and display software system developed by NASA are described. The program was devised to permit objective, versatile, and practical analysis of satellite meteorological data using a minicomputer and a display system with graphics capability. A data area can be selected within the data file for the globe, and data-sparse regions can be avoided. Distances between observations and the nearest observation points are calculated in order to avoid errors when determining synoptic weather conditions. The Barnes (1973) successive correction method is employed to restore the amplitude of small yet resolvable wavelengths suppressed in an initial filtering pass. The rms deviation is then calculated in relation to available measured data. Examples are provided of treatment of VISSR data from the GOES satellite and a study of the impact of incorrect cloud height data on synoptic weather field analysis.

  10. The surgical experience of general surgery residents: an analysis of the applicability of the specialty program in General and Digestive Surgery.

    Science.gov (United States)

    Targarona Soler, Eduardo Ma; Jover Navalon, Jose Ma; Gutierrez Saiz, Javier; Turrado Rodríguez, Víctor; Parrilla Paricio, Pascual

    2015-03-01

    Residents in our country have achieved a homogenous surgical training by following a structured residency program. This is due to the existence of specific training programs for each specialty. The current program, approved in 2007, has a detailed list of procedures that a surgeon should have performed in order to complete training. The aim of this study is to analyze the applicability of the program with regard to the number of procedures performed during the residency period. A data collection form was designed that included the list of procedures from the program of the specialty; it was sent in April 2014 to all hospitals with accredited residency programs. In September 2014 the forms were analysed, and a general descriptive study was performed; a subanalysis according to the resident's sex and Autonomous region was also performed. The number of procedures performed according to the number of residents in the different centers was also analyzed. The survey was sent to 117 hospitals with accredited programs, which included 190 resident places. A total of 91 hospitals responded (53%). The training offered adapts in general to the specialty program. The total number of procedures performed in the different sub-areas, in laparoscopic and emergency surgery is correct or above the number recommended by the program, with the exception of esophageal-gastric and hepatobiliary surgery. The sub-analysis according to Autonomous region did not show any significant differences in the total number of procedures, however, there were significant differences in endocrine surgery (P=.001) and breast surgery (P=.042). A total of 55% of residents are female, with no significant differences in distribution in Autonomous regions. However, female surgeons operate more than their male counterparts during the residency period (512±226 vs. 625±244; P<.01). The number of residents in the hospital correlates with the number of procedures performed; the residents with more procedures

  11. DATE analysis: A general theory of biological change applied to microarray data.

    Science.gov (United States)

    Rasnick, David

    2009-01-01

    In contrast to conventional data mining, which searches for specific subsets of genes (extensive variables) to correlate with specific phenotypes, DATE analysis correlates intensive state variables calculated from the same datasets. At the heart of DATE analysis are two biological equations of state not dependent on genetic pathways. This result distinguishes DATE analysis from other bioinformatics approaches. The dimensionless state variable F quantifies the relative overall cellular activity of test cells compared to well-chosen reference cells. The variable pi(i) is the fold-change in the expression of the ith gene of test cells relative to reference. It is the fraction phi of the genome undergoing differential expression-not the magnitude pi-that controls biological change. The state variable phi is equivalent to the control strength of metabolic control analysis. For tractability, DATE analysis assumes a linear system of enzyme-connected networks and exploits the small average contribution of each cellular component. This approach was validated by reproducible values of the state variables F, RNA index, and phi calculated from random subsets of transcript microarray data. Using published microarray data, F, RNA index, and phi were correlated with: (1) the blood-feeding cycle of the malaria parasite, (2) embryonic development of the fruit fly, (3) temperature adaptation of Killifish, (4) exponential growth of cultured S. pneumoniae, and (5) human cancers. DATE analysis was applied to aCGH data from the great apes. A good example of the power of DATE analysis is its application to genomically unstable cancers, which have been refractory to data mining strategies. 2009 American Institute of Chemical Engineers Biotechnol.

  12. Causes of General Aviation Weather-Related, Non-Fatal Incidents: Analysis Using NASA Aviation Safety Reporting System Data

    Science.gov (United States)

    2010-09-01

    Certified Flight Instructor-Instrument CFIT Controlled flight into terrain FAA U.S. Federal Aviation Administration FBO Fixed-base operator FSS Flight...William R. Knecht Michael Lenz Civil Aerospace Medical Institute Federal Aviation Administration Oklahoma City, OK 73125 September 2010 Final Report...Causes of General Aviation Weather- Related, Non-Fatal Incidents: Analysis Using NASA Aviation Safety Reporting System Data DOT/FAA/AM-10/13 Office

  13. A meta-analysis of seaweed impacts on seagrasses: generalities and knowledge gaps.

    Directory of Open Access Journals (Sweden)

    Mads S Thomsen

    Full Text Available Seagrasses are important habitat-formers and ecosystem engineers that are under threat from bloom-forming seaweeds. These seaweeds have been suggested to outcompete the seagrasses, particularly when facilitated by eutrophication, causing regime shifts where green meadows and clear waters are replaced with unstable sediments, turbid waters, hypoxia, and poor habitat conditions for fishes and invertebrates. Understanding the situations under which seaweeds impact seagrasses on local patch scales can help proactive management and prevent losses at greater scales. Here, we provide a quantitative review of available published manipulative experiments (all conducted at the patch-scale, to test which attributes of seaweeds and seagrasses (e.g., their abundances, sizes, morphology, taxonomy, attachment type, or origin influence impacts. Weighted and unweighted meta-analyses (Hedges d metric of 59 experiments showed generally high variability in attribute-impact relationships. Our main significant findings were that (a abundant seaweeds had stronger negative impacts on seagrasses than sparse seaweeds, (b unattached and epiphytic seaweeds had stronger impacts than 'rooted' seaweeds, and (c small seagrass species were more susceptible than larger species. Findings (a and (c were rather intuitive. It was more surprising that 'rooted' seaweeds had comparatively small impacts, particularly given that this category included the infamous invasive Caulerpa species. This result may reflect that seaweed biomass and/or shading and metabolic by-products like anoxia and sulphides could be lower for rooted seaweeds. In conclusion, our results represent simple and robust first-order generalities about seaweed impacts on seagrasses. This review also documented a limited number of primary studies. We therefore identified major knowledge gaps that need to be addressed before general predictive models on seaweed-seagrass interactions can be build, in order to effectively

  14. A meta-analysis of seaweed impacts on seagrasses: generalities and knowledge gaps.

    Science.gov (United States)

    Thomsen, Mads S; Wernberg, Thomas; Engelen, Aschwin H; Tuya, Fernando; Vanderklift, Mat A; Holmer, Marianne; McGlathery, Karen J; Arenas, Francisco; Kotta, Jonne; Silliman, Brian R

    2012-01-01

    Seagrasses are important habitat-formers and ecosystem engineers that are under threat from bloom-forming seaweeds. These seaweeds have been suggested to outcompete the seagrasses, particularly when facilitated by eutrophication, causing regime shifts where green meadows and clear waters are replaced with unstable sediments, turbid waters, hypoxia, and poor habitat conditions for fishes and invertebrates. Understanding the situations under which seaweeds impact seagrasses on local patch scales can help proactive management and prevent losses at greater scales. Here, we provide a quantitative review of available published manipulative experiments (all conducted at the patch-scale), to test which attributes of seaweeds and seagrasses (e.g., their abundances, sizes, morphology, taxonomy, attachment type, or origin) influence impacts. Weighted and unweighted meta-analyses (Hedges d metric) of 59 experiments showed generally high variability in attribute-impact relationships. Our main significant findings were that (a) abundant seaweeds had stronger negative impacts on seagrasses than sparse seaweeds, (b) unattached and epiphytic seaweeds had stronger impacts than 'rooted' seaweeds, and (c) small seagrass species were more susceptible than larger species. Findings (a) and (c) were rather intuitive. It was more surprising that 'rooted' seaweeds had comparatively small impacts, particularly given that this category included the infamous invasive Caulerpa species. This result may reflect that seaweed biomass and/or shading and metabolic by-products like anoxia and sulphides could be lower for rooted seaweeds. In conclusion, our results represent simple and robust first-order generalities about seaweed impacts on seagrasses. This review also documented a limited number of primary studies. We therefore identified major knowledge gaps that need to be addressed before general predictive models on seaweed-seagrass interactions can be build, in order to effectively protect

  15. A Meta-Analysis of Seaweed Impacts on Seagrasses: Generalities and Knowledge Gaps

    Science.gov (United States)

    Thomsen, Mads S.; Wernberg, Thomas; Engelen, Aschwin H.; Tuya, Fernando; Vanderklift, Mat A.; Holmer, Marianne; McGlathery, Karen J.; Arenas, Francisco; Kotta, Jonne; Silliman, Brian R.

    2012-01-01

    Seagrasses are important habitat-formers and ecosystem engineers that are under threat from bloom-forming seaweeds. These seaweeds have been suggested to outcompete the seagrasses, particularly when facilitated by eutrophication, causing regime shifts where green meadows and clear waters are replaced with unstable sediments, turbid waters, hypoxia, and poor habitat conditions for fishes and invertebrates. Understanding the situations under which seaweeds impact seagrasses on local patch scales can help proactive management and prevent losses at greater scales. Here, we provide a quantitative review of available published manipulative experiments (all conducted at the patch-scale), to test which attributes of seaweeds and seagrasses (e.g., their abundances, sizes, morphology, taxonomy, attachment type, or origin) influence impacts. Weighted and unweighted meta-analyses (Hedges d metric) of 59 experiments showed generally high variability in attribute-impact relationships. Our main significant findings were that (a) abundant seaweeds had stronger negative impacts on seagrasses than sparse seaweeds, (b) unattached and epiphytic seaweeds had stronger impacts than ‘rooted’ seaweeds, and (c) small seagrass species were more susceptible than larger species. Findings (a) and (c) were rather intuitive. It was more surprising that ‘rooted’ seaweeds had comparatively small impacts, particularly given that this category included the infamous invasive Caulerpa species. This result may reflect that seaweed biomass and/or shading and metabolic by-products like anoxia and sulphides could be lower for rooted seaweeds. In conclusion, our results represent simple and robust first-order generalities about seaweed impacts on seagrasses. This review also documented a limited number of primary studies. We therefore identified major knowledge gaps that need to be addressed before general predictive models on seaweed-seagrass interactions can be build, in order to effectively

  16. Identifying patient safety problems associated with information technology in general practice: an analysis of incident reports.

    Science.gov (United States)

    Magrabi, Farah; Liaw, Siaw Teng; Arachi, Diana; Runciman, William; Coiera, Enrico; Kidd, Michael R

    2016-11-01

    To identify the categories of problems with information technology (IT), which affect patient safety in general practice. General practitioners (GPs) reported incidents online or by telephone between May 2012 and November 2013. Incidents were reviewed against an existing classification for problems associated with IT and the clinical process impacted. 87 GPs across Australia. Types of problems, consequences and clinical processes. GPs reported 90 incidents involving IT which had an observable impact on the delivery of care, including actual patient harm as well as near miss events. Practice systems and medications were the most affected clinical processes. Problems with IT disrupted clinical workflow, wasted time and caused frustration. Issues with user interfaces, routine updates to software packages and drug databases, and the migration of records from one package to another generated clinical errors that were unique to IT; some could affect many patients at once. Human factors issues gave rise to some errors that have always existed with paper records but are more likely to occur and cause harm with IT. Such errors were linked to slips in concentration, multitasking, distractions and interruptions. Problems with patient identification and hybrid records generated errors that were in principle no different to paper records. Problems associated with IT include perennial risks with paper records, but additional disruptions in workflow and hazards for patients unique to IT, occasionally affecting multiple patients. Surveillance for such hazards may have general utility, but particularly in the context of migrating historical records to new systems and software updates to existing systems. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  17. Cross-channel analysis of quark and gluon generalized parton distributions with helicity flip

    International Nuclear Information System (INIS)

    Pire, B.; Semenov-Tian-Shansky, K.; Szymanowski, L.; Wallon, S.

    2014-01-01

    Quark and gluon helicity flip generalized parton distributions (GPDs) address the transversity quark and gluon structure of the nucleon. In order to construct a theoretically consistent parametrization of these hadronic matrix elements, we work out the set of combinations of those GPDs suitable for the SO(3) partial wave (PW) expansion in the cross-channel. This universal result will help to build up a flexible parametrization of these important hadronic non-perturbative quantities, using, for instance, the approaches based on the conformal PW expansion of GPDs such as the Mellin-Barnes integral or the dual parametrization techniques. (orig.)

  18. Cross-channel analysis of quark and gluon generalized parton distributions with helicity flip

    Energy Technology Data Exchange (ETDEWEB)

    Pire, B. [CNRS, CPhT, Ecole Polytechnique, Palaiseau (France); Semenov-Tian-Shansky, K. [Universite de Liege, IFPA, Departement AGO, Liege (Belgium); Szymanowski, L. [National Centre for Nuclear Research (NCBJ), Warsaw (Poland); Wallon, S. [Universite de Paris-Sud, CNRS, LPT, Orsay (France); Universite Paris 06, Faculte de Physique, UPMC, Paris (France)

    2014-05-15

    Quark and gluon helicity flip generalized parton distributions (GPDs) address the transversity quark and gluon structure of the nucleon. In order to construct a theoretically consistent parametrization of these hadronic matrix elements, we work out the set of combinations of those GPDs suitable for the SO(3) partial wave (PW) expansion in the cross-channel. This universal result will help to build up a flexible parametrization of these important hadronic non-perturbative quantities, using, for instance, the approaches based on the conformal PW expansion of GPDs such as the Mellin-Barnes integral or the dual parametrization techniques. (orig.)

  19. General application of system event tree analysis to light water reactors

    International Nuclear Information System (INIS)

    Asselin, S.V.; Carlson, D.D.

    1977-01-01

    The system event tree is a key element in the comparison of light water reactors when considering Reactor Safety Study (RSS) factors such as risk and dominant accident sequences. The development of system event trees involves drawing on the RSS experience and adapting the methodology to reactor plants that may differ considerably, in system functions and interactions, from the RSS plants. This paper describes the methods for the general application of system event trees to light water reactors and is based on work done by Sandia Laboratories for the Nuclear Regulatory Commission on the Reactor Safety Study Methodology Applications Program

  20. MGF approach to the capacity analysis of Generalized Two-Ray fading models

    KAUST Repository

    Rao, Milind

    2015-09-11

    We propose a class of Generalized Two-Ray (GTR) fading channels that consists of two line of sight (LOS) components with random phase and a diffuse component. Observing that the GTR fading model can be expressed in terms of the underlying Rician distribution, we derive a closed-form expression for the moment generating function (MGF) of the signal-to-noise ratio (SNR) of this model. We then employ this approach to compute the ergodic capacity with receiver side information. The impact of the underlying phase difference between the LOS components on the average SNR of the signal received is also illustrated. © 2015 IEEE.

  1. [Protection of genetic data in Spain. Analysis based on the general principles of personal data protection].

    Science.gov (United States)

    García Amez, Javier

    2006-01-01

    The genetic data is Spain is not regulated specifically, rather, we must look at the regulation on the protection of data of a personal nature. This is turn, establishes a series of general principles to apply to any type of data. Analysing this with other regulations that are dispersed both in the national and international regulations, we can deduce the rights and obligations in this field. This highlights the fact that one can't dispose of the genetic data in the same manner as the personal data.

  2. Bending analysis of a piezoelectric curved actuator with a generally graded property for the piezoelectric parameter

    International Nuclear Information System (INIS)

    Shi Zhifei; Zhang Taotao

    2008-01-01

    An analytical study on the bending behavior of a piezoelectric curved actuator with generally graded properties for the piezoelectric parameter g 31 is performed. The external electric potential is acting between the inner and outer surfaces of the actuator. A Taylor series expansion method is introduced and the exact solutions of the problem are obtained based on the theory of piezo-elasticity. The present analytical solutions are compared with the numerical results and good agreement is found. This work gives a sound background for the design and optimization of functionally graded piezoelectric curved actuators

  3. Normalizability analysis of the generalized quantum electrodynamics from the causal point of view

    Science.gov (United States)

    Bufalo, R.; Pimentel, B. M.; Soto, D. E.

    2017-09-01

    The causal perturbation theory is an axiomatic perturbative theory of the S-matrix. This formalism has as its essence the following axioms: causality, Lorentz invariance and asymptotic conditions. Any other property must be showed via the inductive method order-by-order and, of course, it depends on the particular physical model. In this work we shall study the normalizability of the generalized quantum electrodynamics in the framework of the causal approach. Furthermore, we analyze the implication of the gauge invariance onto the model and obtain the respective Ward-Takahashi-Fradkin identities.

  4. A General Model for Representing Arbitrary Unsymmetries in Various Types of Network Analysis

    DEFF Research Database (Denmark)

    Rønne-Hansen, Jan

    1997-01-01

    When dealing with unsymmetric faults various proposals have been put forward. In general they have been characterized by specific treatment of the single fault in accordance with the structure and impedances involved. The model presented is based on node equations and was originally developed...... for transient stability studies in order to allow for an arbitrary fault representation as seen from the positive sequence network. The method results in impedances -or admittances-combining the negative sequence and zero sequence representation for the symmetrical network with the structure and electrical...

  5. GELATIO: a general framework for modular digital analysis of high-purity Ge detector signals

    International Nuclear Information System (INIS)

    Agostini, M; Pandola, L; Zavarise, P; Volynets, O

    2011-01-01

    GELATIO is a new software framework for advanced data analysis and digital signal processing developed for the GERDA neutrinoless double beta decay experiment. The framework is tailored to handle the full analysis flow of signals recorded by high purity Ge detectors and photo-multipliers from the veto counters. It is designed to support a multi-channel modular and flexible analysis, widely customizable by the user either via human-readable initialization files or via a graphical interface. The framework organizes the data into a multi-level structure, from the raw data up to the condensed analysis parameters, and includes tools and utilities to handle the data stream between the different levels. GELATIO is implemented in C++. It relies upon ROOT and its extension TAM, which provides compatibility with PROOF, enabling the software to run in parallel on clusters of computers or many-core machines. It was tested on different platforms and benchmarked in several GERDA-related applications. A stable version is presently available for the GERDA Collaboration and it is used to provide the reference analysis of the experiment data.

  6. Social network analysis. Review of general concepts and use in preventive veterinary medicine.

    Science.gov (United States)

    Martínez-López, B; Perez, A M; Sánchez-Vizcaíno, J M

    2009-05-01

    Social network analysis (SNA) and graph theory have been used widely in sociology, psychology, anthropology, biology and medicine. Social network analysis and graph theory provide a conceptual framework to study contact patterns and to identify units of analysis that are frequently or intensely connected within the network. Social network analysis has been used in human epidemiology as a tool to explore the potential transmission of infectious agents such as HIV, tuberculosis, hepatitis B and syphilis. In preventive veterinary medicine, SNA is an approach that offers benefits for exploring the nature and extent of the contacts between animals or farms, which ultimately leads to a better understanding of the potential risk for disease spread in a susceptible population. Social network analysis, however, has been applied only recently in preventive veterinary medicine, therefore the characteristics of the technique and the potential benefits of its use remain unknown for an important section of the international veterinary medicine community. The objectives of this paper were to review the concepts and theoretical aspects underlying the use of SNA and graph theory, with particular emphasis on their application to the study of infectious diseases of animals. The paper includes a review of recent applications of SNA in preventive veterinary medicine and a discussion of the potential uses and limitations of this methodology for the study of animal diseases.

  7. Generalized Hyperalgesia in Children and Adults Diagnosed With Hypermobility Syndrome and Ehlers-Danlos Syndrome Hypermobility Type: A Discriminative Analysis.

    Science.gov (United States)

    Scheper, M C; Pacey, V; Rombaut, L; Adams, R D; Tofts, L; Calders, P; Nicholson, L L; Engelbert, R H H

    2017-03-01

    Lowered pressure-pain thresholds have been demonstrated in adults with Ehlers-Danlos syndrome hypermobility type (EDS-HT), but whether these findings are also present in children is unclear. Therefore, the objectives of the study were to determine whether generalized hyperalgesia is present in children with hypermobility syndrome (HMS)/EDS-HT, explore potential differences in pressure-pain thresholds between children and adults with HMS/EDS-HT, and determine the discriminative value of generalized hyperalgesia. Patients were classified in 1 of 3 groups: HMS/EDS-HT, hypermobile (Beighton score ≥4 of 9), and healthy controls. Descriptive data of age, sex, body mass index, Beighton score, skin laxity, and medication usage were collected. Generalized hyperalgesia was quantified by the average pressure-pain thresholds collected from 12 locations. Confounders collected were pain locations/intensity, fatigue, and psychological distress. Comparisons between children with HMS/EDS-HT and normative values, between children and adults with HMS/EDS-HT, and corrected confounders were analyzed with multivariate analysis of covariance. The discriminative value of generalized hyperalgesia employed to differentiate between HMS/EDS-HT, hypermobility, and controls was quantified with logistic regression. Significantly lower pressure-pain thresholds were found in children with HMS/EDS-HT compared to normative values (range -22.0% to -59.0%; P ≤ 0.05). When applying a threshold of 30.8 N/cm 2 for males and 29.0 N/cm 2 for females, the presence of generalized hyperalgesia discriminated between individuals with HMS/EDS-HT, hypermobility, and healthy controls (odds ratio 6.0). Children and adults with HMS/EDS-HT are characterized by hypermobility, chronic pain, and generalized hyperalgesia. The presence of generalized hyperalgesia may indicate involvement of the central nervous system in the development of chronic pain. © 2016, American College of Rheumatology.

  8. Association analysis between the -2518MCP-1(A/G) polymorphism and generalized aggressive periodontitis in a Chinese population.

    Science.gov (United States)

    Zhu, X L; Meng, H X; Zhang, L; Xu, L; Chen, Z B; Shi, D; Feng, X H; Zhang, X

    2012-06-01

    It has been suggested that aggressive periodontitis has a genetic basis. Monocyte chemoattractant protein 1 (MCP-1) plays a critical role in the recruitment of monocytes and the development of periodontitis. The -2518MCP-1(A/G) polymorphism has been implicated as a risk or susceptibility factor for a variety of autoimmune conditions and inflammatory diseases. The intent of this investigation was to study whether the -2518MCP-1(A/G) polymorphism is associated with generalized aggressive periodontitis in the Chinese population. One hundred and twenty-four patients with generalized aggressive periodontitis and 94 healthy subjects were included in this case-control study. Genomic DNA was isolated from a peripheral blood sample obtained from each subject. Gene polymorphisms of -2518MCP-1(A/G) were analyzed by a standard polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. A logistic regression analysis was performed to test the association between the -2518MCP-1(A/G) genotype (alleles) and generalized aggressive periodontitis with adjustment of the major covariates (gender, age and smoking status). There was no significant association of the -2518MCP-1(A/G) polymorphism with generalized aggressive periodontitis in the unstratified subjects. However, when patients were stratified by gender, the frequency of the G(+) genotype was significantly lower in female patients with generalized aggressive periodontitis compared with female controls (p = 0.036, adjusted odds ratio = 0.3, 95% CI: 0.1-0.9). In female patients with generalized aggressive periodontitis, the probing pocket depth was larger in subjects with the AA genotype than in subjects with the G(+) genotype (5.07 mm vs. 4.30 mm; Z = -2.470, p = 0.014). The polymorphisms of -2518MCP-1 may play an important role in determining generalized aggressive periodontitis susceptibility in this cohort of Chinese women. © 2011 John Wiley & Sons A/S.

  9. Meta-Analysis of Effect Sizes Reported at Multiple Time Points Using General Linear Mixed Model

    Science.gov (United States)

    Musekiwa, Alfred; Manda, Samuel O. M.; Mwambi, Henry G.; Chen, Ding-Geng

    2016-01-01

    Meta-analysis of longitudinal studies combines effect sizes measured at pre-determined time points. The most common approach involves performing separate univariate meta-analyses at individual time points. This simplistic approach ignores dependence between longitudinal effect sizes, which might result in less precise parameter estimates. In this paper, we show how to conduct a meta-analysis of longitudinal effect sizes where we contrast different covariance structures for dependence between effect sizes, both within and between studies. We propose new combinations of covariance structures for the dependence between effect size and utilize a practical example involving meta-analysis of 17 trials comparing postoperative treatments for a type of cancer, where survival is measured at 6, 12, 18 and 24 months post randomization. Although the results from this particular data set show the benefit of accounting for within-study serial correlation between effect sizes, simulations are required to confirm these results. PMID:27798661

  10. Contributions to sensitivity analysis and generalized discriminant analysis; Contributions a l'analyse de sensibilite et a l'analyse discriminante generalisee

    Energy Technology Data Exchange (ETDEWEB)

    Jacques, J

    2005-12-15

    Two topics are studied in this thesis: sensitivity analysis and generalized discriminant analysis. Global sensitivity analysis of a mathematical model studies how the output variables of this last react to variations of its inputs. The methods based on the study of the variance quantify the part of variance of the response of the model due to each input variable and each subset of input variables. The first subject of this thesis is the impact of a model uncertainty on results of a sensitivity analysis. Two particular forms of uncertainty are studied: that due to a change of the model of reference, and that due to the use of a simplified model with the place of the model of reference. A second problem was studied during this thesis, that of models with correlated inputs. Indeed, classical sensitivity indices not having significance (from an interpretation point of view) in the presence of correlation of the inputs, we propose a multidimensional approach consisting in expressing the sensitivity of the output of the model to groups of correlated variables. Applications in the field of nuclear engineering illustrate this work. Generalized discriminant analysis consists in classifying the individuals of a test sample in groups, by using information contained in a training sample, when these two samples do not come from the same population. This work extends existing methods in a Gaussian context to the case of binary data. An application in public health illustrates the utility of generalized discrimination models thus defined. (author)

  11. How to improve mental health competency in general practice training?--a SWOT analysis.

    Science.gov (United States)

    van Marwijk, Harm

    2004-06-01

    It is quite evident there is room for improvement in the primary care management of common mental health problems. Patients respond positively when GPs adopt a more proactive role in this respect. The Dutch general practice curriculum is currently being renewed. The topics discussed here include the Strengths, Weaknesses, Opportunities and Threats (SWOT) of present primary mental healthcare teaching. What works well and what needs improving? Integrated teaching packages are needed to help general practice trainees manage various presentations of psychological distress. Such packages comprise training videotapes, in which models such as problem-solving treatment (PST) are demonstrated, as well as roleplaying material for new skills, self-report questionnaires for patients, and small-group video feedback of consultations. While GP trainees can effectively master such skills, it is important to query the level of proficiency required by registrars. Are these skills of use only to connoisseur GPs, or to all? More room for specialisation and differentiation among trainees may be the way forward. We have just developed a new curriculum for the obligatory three-month psychiatry housemanship. It is competency oriented, self-directed and assignment driven. This new curriculum will be evaluated in due course.

  12. Threshold Estimation of Generalized Pareto Distribution Based on Akaike Information Criterion for Accurate Reliability Analysis

    International Nuclear Information System (INIS)

    Kang, Seunghoon; Lim, Woochul; Cho, Su-gil; Park, Sanghyun; Lee, Tae Hee; Lee, Minuk; Choi, Jong-su; Hong, Sup

    2015-01-01

    In order to perform estimations with high reliability, it is necessary to deal with the tail part of the cumulative distribution function (CDF) in greater detail compared to an overall CDF. The use of a generalized Pareto distribution (GPD) to model the tail part of a CDF is receiving more research attention with the goal of performing estimations with high reliability. Current studies on GPDs focus on ways to determine the appropriate number of sample points and their parameters. However, even if a proper estimation is made, it can be inaccurate as a result of an incorrect threshold value. Therefore, in this paper, a GPD based on the Akaike information criterion (AIC) is proposed to improve the accuracy of the tail model. The proposed method determines an accurate threshold value using the AIC with the overall samples before estimating the GPD over the threshold. To validate the accuracy of the method, its reliability is compared with that obtained using a general GPD model with an empirical CDF

  13. Behavioral and electrophysiological analysis of general anesthesia in 3 background strains of Drosophila melanogaster.

    Science.gov (United States)

    Zalucki, Oressia; Day, Rebecca; Kottler, Benjamin; Karunanithi, Shanker; van Swinderen, Bruno

    2015-01-01

    General anesthetics achieve behavioral unresponsiveness via a mechanism that is incompletely understood. The study of genetic model systems such as the fruit fly Drosophila melanogaster is crucial to advancing our understanding of how anesthetic drugs render animals unresponsive. Previous studies have shown that wild-type control strains differ significantly in their sensitivity to general anesthetics, which potentially introduces confounding factors for comparing genetic mutations placed on these wild-type backgrounds. Here, we examined a variety of behavioral and electrophysiological endpoints in Drosophila, in both adult and larval animals. We characterized these endpoints in 3 commonly used fly strains: wild-type Canton Special (CS), and 2 commonly used white-eyed strains, isoCJ1 and w(1118). We found that CS and isoCJ1 show remarkably similar sensitivity to isoflurane across a variety of behavioral and electrophysiological endpoints. In contrast, w(1118) is resistant to isoflurane compared to the other 2 strains at both the adult and larval stages. This resistance is however not reflected at the level of neurotransmitter release at the larval neuromuscular junction (NMJ). This suggests that the w(1118) strain harbors another mutation that produces isoflurane resistance, by acting on an arousal pathway that is most likely preserved between larval and adult brains. This mutation probably also affects sleep, as marked differences between isoCJ1 and w(1118) have also recently been found for behavioral responsiveness and sleep intensity measures.

  14. Analysis of ray trajectories of flexural waves propagating over generalized acoustic black hole indentations

    Science.gov (United States)

    Huang, Wei; Ji, Hongli; Qiu, Jinhao; Cheng, Li

    2018-03-01

    An Acoustic Black Hole (ABH) indentation embedded in thin-walled structures has been proved remarkably useful for broadband flexural wave focalization, in which the phase velocity of the flexural waves and the refractive index of the media undergo gradual changes from the outside towards the center of the indentation. A generalized two-dimensional ABH indentation can be defined by three geometric parameters: a power index, an extra thickness and a radius of a plateau at the indentation center. The dependence of the energy focalization on these parameters as well as the energy focalization process is of paramount importance for the understanding and design of effective ABH indentations. This work aims at investigating the energy focalization characteristics of flexural waves in such generalized ABH indentations. The calculation of the flexural ray trajectories is conducted to reveal and analyze the wave propagation features through numerical integration of the eikonal equation from the Geometric Acoustics Approximation (GAA). The theoretical results are verified by both experiment using wave visualization technique based on laser acoustic scanning method and finite element (FE) simulations. Finally, the influence of the geometric parameters on the flexural wave focalization characteristics in ABH indentations is discussed in detail.

  15. Analysis of railroad tank car releases using a generalized binomial model.

    Science.gov (United States)

    Liu, Xiang; Hong, Yili

    2015-11-01

    The United States is experiencing an unprecedented boom in shale oil production, leading to a dramatic growth in petroleum crude oil traffic by rail. In 2014, U.S. railroads carried over 500,000 tank carloads of petroleum crude oil, up from 9500 in 2008 (a 5300% increase). In light of continual growth in crude oil by rail, there is an urgent national need to manage this emerging risk. This need has been underscored in the wake of several recent crude oil release incidents. In contrast to highway transport, which usually involves a tank trailer, a crude oil train can carry a large number of tank cars, having the potential for a large, multiple-tank-car release incident. Previous studies exclusively assumed that railroad tank car releases in the same train accident are mutually independent, thereby estimating the number of tank cars releasing given the total number of tank cars derailed based on a binomial model. This paper specifically accounts for dependent tank car releases within a train accident. We estimate the number of tank cars releasing given the number of tank cars derailed based on a generalized binomial model. The generalized binomial model provides a significantly better description for the empirical tank car accident data through our numerical case study. This research aims to provide a new methodology and new insights regarding the further development of risk management strategies for improving railroad crude oil transportation safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Images of orbitals in twentieth-century General Chemistry textbooks: a semiotic analysis

    Directory of Open Access Journals (Sweden)

    Evandro Fortes Rozentalski

    2015-03-01

    Full Text Available This paper aims at investigating how the images of orbitals were presented in undergraduate General Chemistry textbooks throughout the twentieth century. Special attention was given to ontological and epistemological aspects related to such images. Images of orbitals from twenty-six textbooks used in Brazilian universities were analyzed according to Peircean semiotics, in order to assess: the nature of the orbital; what is the relation between representation and the represented object; what aspects of the object are highlighted by means of the representation; what are the limits and potentialities of the representation. It is observed that the images of orbitals in the textbooks are generally described as representations of maximum probability density and identified as limit surfaces. Such images present orbitals as possessing well defined sizes, shapes and directional nature. There is not sufficient information in most textbooks on the meaning of such images, especially regarding: the object of which representation takes place; how the images were produced; what aspects of the object the representation highlight; and what are the similarities and differences between the several images related to an orbital. Teaching difficulties arising from the features discussed here may be overcome by means of explicit discussion on the production, use and meaning of the representations, supported by Peircean semiotics.

  17. Bifurcation analysis on a generalized recurrent neural network with two interconnected three-neuron components

    International Nuclear Information System (INIS)

    Hajihosseini, Amirhossein; Maleki, Farzaneh; Rokni Lamooki, Gholam Reza

    2011-01-01

    Highlights: → We construct a recurrent neural network by generalizing a specific n-neuron network. → Several codimension 1 and 2 bifurcations take place in the newly constructed network. → The newly constructed network has higher capabilities to learn periodic signals. → The normal form theorem is applied to investigate dynamics of the network. → A series of bifurcation diagrams is given to support theoretical results. - Abstract: A class of recurrent neural networks is constructed by generalizing a specific class of n-neuron networks. It is shown that the newly constructed network experiences generic pitchfork and Hopf codimension one bifurcations. It is also proved that the emergence of generic Bogdanov-Takens, pitchfork-Hopf and Hopf-Hopf codimension two, and the degenerate Bogdanov-Takens bifurcation points in the parameter space is possible due to the intersections of codimension one bifurcation curves. The occurrence of bifurcations of higher codimensions significantly increases the capability of the newly constructed recurrent neural network to learn broader families of periodic signals.

  18. GenoGAM: genome-wide generalized additive models for ChIP-Seq analysis.

    Science.gov (United States)

    Stricker, Georg; Engelhardt, Alexander; Schulz, Daniel; Schmid, Matthias; Tresch, Achim; Gagneur, Julien

    2017-08-01

    Chromatin immunoprecipitation followed by deep sequencing (ChIP-Seq) is a widely used approach to study protein-DNA interactions. Often, the quantities of interest are the differential occupancies relative to controls, between genetic backgrounds, treatments, or combinations thereof. Current methods for differential occupancy of ChIP-Seq data rely however on binning or sliding window techniques, for which the choice of the window and bin sizes are subjective. Here, we present GenoGAM (Genome-wide Generalized Additive Model), which brings the well-established and flexible generalized additive models framework to genomic applications using a data parallelism strategy. We model ChIP-Seq read count frequencies as products of smooth functions along chromosomes. Smoothing parameters are objectively estimated from the data by cross-validation, eliminating ad hoc binning and windowing needed by current approaches. GenoGAM provides base-level and region-level significance testing for full factorial designs. Application to a ChIP-Seq dataset in yeast showed increased sensitivity over existing differential occupancy methods while controlling for type I error rate. By analyzing a set of DNA methylation data and illustrating an extension to a peak caller, we further demonstrate the potential of GenoGAM as a generic statistical modeling tool for genome-wide assays. Software is available from Bioconductor: https://www.bioconductor.org/packages/release/bioc/html/GenoGAM.html . gagneur@in.tum.de. Supplementary information is available at Bioinformatics online.

  19. An analysis of noise in recurrent neural networks: convergence and generalization.

    Science.gov (United States)

    Jim, K C; Giles, C L; Horne, B G

    1996-01-01

    Concerns the effect of noise on the performance of feedforward neural nets. We introduce and analyze various methods of injecting synaptic noise into dynamically driven recurrent nets during training. Theoretical results show that applying a controlled amount of noise during training may improve convergence and generalization performance. We analyze the effects of various noise parameters and predict that best overall performance can be achieved by injecting additive noise at each time step. Noise contributes a second-order gradient term to the error function which can be viewed as an anticipatory agent to aid convergence. This term appears to find promising regions of weight space in the beginning stages of training when the training error is large and should improve convergence on error surfaces with local minima. The first-order term is a regularization term that can improve generalization. Specifically, it can encourage internal representations where the state nodes operate in the saturated regions of the sigmoid discriminant function. While this effect can improve performance on automata inference problems with binary inputs and target outputs, it is unclear what effect it will have on other types of problems. To substantiate these predictions, we present simulations on learning the dual parity grammar from temporal strings for all noise models, and present simulations on learning a randomly generated six-state grammar using the predicted best noise model.

  20. The Statistical Analysis of General Processing Tree Models with the EM Algorithm.

    Science.gov (United States)

    Hu, Xiangen; Batchelder, William H.

    1994-01-01

    The statistical analysis of processing tree models is advanced by showing how the parameters of estimation and hypothesis testing, based on the likelihood functions, can be accomplished by adapting the expectation-maximization (EM) algorithm. The adaptation makes it easy to program a personal computer to accomplish the stages of statistical…