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Sample records for publication bias analyses

  1. Publication bias in dermatology systematic reviews and meta-analyses.

    Science.gov (United States)

    Atakpo, Paul; Vassar, Matt

    2016-05-01

    Systematic reviews and meta-analyses in dermatology provide high-level evidence for clinicians and policy makers that influence clinical decision making and treatment guidelines. One methodological problem with systematic reviews is the under representation of unpublished studies. This problem is due in part to publication bias. Omission of statistically non-significant data from meta-analyses may result in overestimation of treatment effect sizes which may lead to clinical consequences. Our goal was to assess whether systematic reviewers in dermatology evaluate and report publication bias. Further, we wanted to conduct our own evaluation of publication bias on meta-analyses that failed to do so. Our study considered systematic reviews and meta-analyses from ten dermatology journals from 2006 to 2016. A PubMed search was conducted, and all full-text articles that met our inclusion criteria were retrieved and coded by the primary author. 293 articles were included in our analysis. Additionally, we formally evaluated publication bias in meta-analyses that failed to do so using trim and fill and cumulative meta-analysis by precision methods. Publication bias was mentioned in 107 articles (36.5%) and was formally evaluated in 64 articles (21.8%). Visual inspection of a funnel plot was the most common method of evaluating publication bias. Publication bias was present in 45 articles (15.3%), not present in 57 articles (19.5%) and not determined in 191 articles (65.2%). Using the trim and fill method, 7 meta-analyses (33.33%) showed evidence of publication bias. Although the trim and fill method only found evidence of publication bias in 7 meta-analyses, the cumulative meta-analysis by precision method found evidence of publication bias in 15 meta-analyses (71.4%). Many of the reviews in our study did not mention or evaluate publication bias. Further, of the 42 articles that stated following PRISMA reporting guidelines, 19 (45.2%) evaluated for publication bias. In

  2. Publication Bias and Nonreporting Found in Majority of Systematic Reviews and Meta-analyses in Anesthesiology Journals.

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    Hedin, Riley J; Umberham, Blake A; Detweiler, Byron N; Kollmorgen, Lauren; Vassar, Matt

    2016-10-01

    Systematic reviews and meta-analyses are used by clinicians to derive treatment guidelines and make resource allocation decisions in anesthesiology. One cause for concern with such reviews is the possibility that results from unpublished trials are not represented in the review findings or data synthesis. This problem, known as publication bias, results when studies reporting statistically nonsignificant findings are left unpublished and, therefore, not included in meta-analyses when estimating a pooled treatment effect. In turn, publication bias may lead to skewed results with overestimated effect sizes. The primary objective of this study is to determine the extent to which evaluations for publication bias are conducted by systematic reviewers in highly ranked anesthesiology journals and which practices reviewers use to mitigate publication bias. The secondary objective of this study is to conduct publication bias analyses on the meta-analyses that did not perform these assessments and examine the adjusted pooled effect estimates after accounting for publication bias. This study considered meta-analyses and systematic reviews from 5 peer-reviewed anesthesia journals from 2007 through 2015. A PubMed search was conducted, and full-text systematic reviews that fit inclusion criteria were downloaded and coded independently by 2 authors. Coding was then validated, and disagreements were settled by consensus. In total, 207 systematic reviews were included for analysis. In addition, publication bias evaluation was performed for 25 systematic reviews that did not do so originally. We used Egger regression, Duval and Tweedie trim and fill, and funnel plots for these analyses. Fifty-five percent (n = 114) of the reviews discussed publication bias, and 43% (n = 89) of the reviews evaluated publication bias. Funnel plots and Egger regression were the most common methods for evaluating publication bias. Publication bias was reported in 34 reviews (16%). Thirty-six of the 45

  3. Publication Bias in Meta-Analyses of the Efficacy of Psychotherapeutic Interventions for Depression

    Science.gov (United States)

    Niemeyer, Helen; Musch, Jochen; Pietrowsky, Reinhard

    2013-01-01

    Objective: The aim of this study was to assess whether systematic reviews investigating psychotherapeutic interventions for depression are affected by publication bias. Only homogeneous data sets were included, as heterogeneous data sets can distort statistical tests of publication bias. Method: We applied Begg and Mazumdar's adjusted rank…

  4. Editorial bias in scientific publications.

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    Matías-Guiu, J; García-Ramos, R

    2011-01-01

    Many authors believe that there are biases in scientific publications. Editorial biases include publication bias; which refers to those situations where the results influence the editor's decision, and editorial bias refers to those situations where factors related with authors or their environment influence the decision. This paper includes an analysis of the situation of editorial biases. One bias is where mainly articles with positive results are accepted, as opposed to those with negative results. Another is latent bias, where positive results are published before those with negative results. In order to examine editorial bias, this paper analyses the influence of where the article originated; the country or continent, academic centre of origin, belonging to cooperative groups, and the maternal language of the authors. The article analyses biases in the editorial process in the publication of funded clinical trials. Editorial biases exists. Authors, when submitting their manuscript, should analyse different journals and decide where their article will receive adequate treatment. Copyright © 2010 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  5. Is grey literature essential for a better control of publication bias in psychiatry? An example from three meta-analyses of schizophrenia.

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    Martin, José Luis R; Pérez, Víctor; Sacristán, Montse; Alvarez, Enric

    2005-12-01

    Systematic reviews in mental health have become useful tools for health professionals in view of the massive amount and heterogeneous nature of biomedical information available today. In order to determine the risk of bias in the studies evaluated and to avoid bias in generalizing conclusions from the reviews it is therefore important to use a very strict methodology in systematic reviews. One bias which may affect the generalization of results is publication bias, which is determined by the nature and direction of the study results. To control or minimize this type of bias, the authors of systematic reviews undertake comprehensive searches of medical databases and expand on the findings, often undertaking searches of grey literature (material which is not formally published). This paper attempts to show the consequences (and risk) of generalizing the implications of grey literature in the control of publication bias, as was proposed in a recent systematic work. By repeating the analyses for the same outcome from three different systematic reviews that included both published and grey literature our results showed that confusion between grey literature and publication bias may affect the results of a concrete meta-analysis.

  6. Publication bias in epidemiological studies.

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    Siddiqi, Nazish

    2011-06-01

    Communication of research findings is the utmost responsibility of all scientists. Publication bias occurs if scientific studies with negative or null results fail to get published. This can happen due to bias in submitting, reviewing, accepting, publishing or aggregating scientific literature that fails to show positive results on a particular topic. Publication bias can make scientific literature unrepresentative of the actual research studies. This can give the reader a false impression about the beneficial effects of a particular treatment or intervention and can influence clinical decision making. Publication bias is more common than it is actually considered to be, but there are ways to detect and prevent it. This paper comments on the occurrence, types and consequences of publication bias and the strategies employed to detect and control it.

  7. Is there evidence of publication biases in JDM research?

    Directory of Open Access Journals (Sweden)

    Frank Renkewitz

    2011-12-01

    Full Text Available It is a long known problem that the preferential publication of statistically significant results (publication bias may lead to incorrect estimates of the true effects being investigated. Even though other research areas (e.g., medicine, biology are aware of the problem, and have identified strong publication biases, researchers in judgment and decision making (JDM largely ignore it. We reanalyzed two current meta-analyses in this area. Both showed evidence of publication biases that may have led to a substantial overestimation of the true effects they investigated. A review of additional JDM meta-analyses shows that most meta-analyses conducted no or insufficient analyses of publication bias. However, given our results and the rareness of non-significant effects in the literature, we suspect that biases occur quite often. These findings suggest that (a conclusions based on meta-analyses without reported tests of publication bias should be interpreted with caution and (b publication policies and standard research practices should be revised to overcome the problem.

  8. A Bayesian approach to mitigation of publication bias.

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    Guan, Maime; Vandekerckhove, Joachim

    2016-02-01

    The reliability of published research findings in psychology has been a topic of rising concern. Publication bias, or treating positive findings differently from negative findings, is a contributing factor to this "crisis of confidence," in that it likely inflates the number of false-positive effects in the literature. We demonstrate a Bayesian model averaging approach that takes into account the possibility of publication bias and allows for a better estimate of true underlying effect size. Accounting for the possibility of bias leads to a more conservative interpretation of published studies as well as meta-analyses. We provide mathematical details of the method and examples.

  9. A theoretical model for analysing gender bias in medicine

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    Johansson Eva E

    2009-08-01

    Full Text Available Abstract During the last decades research has reported unmotivated differences in the treatment of women and men in various areas of clinical and academic medicine. There is an ongoing discussion on how to avoid such gender bias. We developed a three-step-theoretical model to understand how gender bias in medicine can occur and be understood. In this paper we present the model and discuss its usefulness in the efforts to avoid gender bias. In the model gender bias is analysed in relation to assumptions concerning difference/sameness and equity/inequity between women and men. Our model illustrates that gender bias in medicine can arise from assuming sameness and/or equity between women and men when there are genuine differences to consider in biology and disease, as well as in life conditions and experiences. However, gender bias can also arise from assuming differences when there are none, when and if dichotomous stereotypes about women and men are understood as valid. This conceptual thinking can be useful for discussing and avoiding gender bias in clinical work, medical education, career opportunities and documents such as research programs and health care policies. Too meet the various forms of gender bias, different facts and measures are needed. Knowledge about biological differences between women and men will not reduce bias caused by gendered stereotypes or by unawareness of health problems and discrimination associated with gender inequity. Such bias reflects unawareness of gendered attitudes and will not change by facts only. We suggest consciousness-rising activities and continuous reflections on gender attitudes among students, teachers, researchers and decision-makers.

  10. Publication Bias The "File-Drawer Problem" in Scientific Inference

    CERN Document Server

    Scargle, J D

    1999-01-01

    Publication bias arises whenever the probability that a study is published depends on the statistical significance of its results. This bias, often called the file-drawer effect since the unpublished results are imagined to be tucked away in researchers' file cabinets, is potentially a severe impediment to combining the statistical results of studies collected from the literature. With almost any reasonable quantitative model for publication bias, only a small number of studies lost in the file-drawer will produce a significant bias. This result contradicts the well known Fail Safe File Drawer (FSFD) method for setting limits on the potential harm of publication bias, widely used in social, medical and psychic research. This method incorrectly treats the file drawer as unbiased, and almost always misestimates the seriousness of publication bias. A large body of not only psychic research, but medical and social science studies, has mistakenly relied on this method to validate claimed discoveries. Statistical c...

  11. Publication and other reporting biases in cognitive sciences: detection, prevalence, and prevention.

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    Ioannidis, John P A; Munafò, Marcus R; Fusar-Poli, Paolo; Nosek, Brian A; David, Sean P

    2014-05-01

    Recent systematic reviews and empirical evaluations of the cognitive sciences literature suggest that publication and other reporting biases are prevalent across diverse domains of cognitive science. In this review, we summarize the various forms of publication and reporting biases and other questionable research practices, and overview the available methods for probing into their existence. We discuss the available empirical evidence for the presence of such biases across the neuroimaging, animal, other preclinical, psychological, clinical trials, and genetics literature in the cognitive sciences. We also highlight emerging solutions (from study design to data analyses and reporting) to prevent bias and improve the fidelity in the field of cognitive science research.

  12. Publication bias and the failure of replication in experimental psychology.

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    Francis, Gregory

    2012-12-01

    Replication of empirical findings plays a fundamental role in science. Among experimental psychologists, successful replication enhances belief in a finding, while a failure to replicate is often interpreted to mean that one of the experiments is flawed. This view is wrong. Because experimental psychology uses statistics, empirical findings should appear with predictable probabilities. In a misguided effort to demonstrate successful replication of empirical findings and avoid failures to replicate, experimental psychologists sometimes report too many positive results. Rather than strengthen confidence in an effect, too much successful replication actually indicates publication bias, which invalidates entire sets of experimental findings. Researchers cannot judge the validity of a set of biased experiments because the experiment set may consist entirely of type I errors. This article shows how an investigation of the effect sizes from reported experiments can test for publication bias by looking for too much successful replication. Simulated experiments demonstrate that the publication bias test is able to discriminate biased experiment sets from unbiased experiment sets, but it is conservative about reporting bias. The test is then applied to several studies of prominent phenomena that highlight how publication bias contaminates some findings in experimental psychology. Additional simulated experiments demonstrate that using Bayesian methods of data analysis can reduce (and in some cases, eliminate) the occurrence of publication bias. Such methods should be part of a systematic process to remove publication bias from experimental psychology and reinstate the important role of replication as a final arbiter of scientific findings.

  13. Systematic review of the empirical evidence of study publication bias and outcome reporting bias.

    Directory of Open Access Journals (Sweden)

    Kerry Dwan

    Full Text Available BACKGROUND: The increased use of meta-analysis in systematic reviews of healthcare interventions has highlighted several types of bias that can arise during the completion of a randomised controlled trial. Study publication bias has been recognised as a potential threat to the validity of meta-analysis and can make the readily available evidence unreliable for decision making. Until recently, outcome reporting bias has received less attention. METHODOLOGY/PRINCIPAL FINDINGS: We review and summarise the evidence from a series of cohort studies that have assessed study publication bias and outcome reporting bias in randomised controlled trials. Sixteen studies were eligible of which only two followed the cohort all the way through from protocol approval to information regarding publication of outcomes. Eleven of the studies investigated study publication bias and five investigated outcome reporting bias. Three studies have found that statistically significant outcomes had a higher odds of being fully reported compared to non-significant outcomes (range of odds ratios: 2.2 to 4.7. In comparing trial publications to protocols, we found that 40-62% of studies had at least one primary outcome that was changed, introduced, or omitted. We decided not to undertake meta-analysis due to the differences between studies. CONCLUSIONS: Recent work provides direct empirical evidence for the existence of study publication bias and outcome reporting bias. There is strong evidence of an association between significant results and publication; studies that report positive or significant results are more likely to be published and outcomes that are statistically significant have higher odds of being fully reported. Publications have been found to be inconsistent with their protocols. Researchers need to be aware of the problems of both types of bias and efforts should be concentrated on improving the reporting of trials.

  14. Publication Bias ( The "File-Drawer Problem") in Scientific Inference

    Science.gov (United States)

    Scargle, Jeffrey D.; DeVincenzi, Donald (Technical Monitor)

    1999-01-01

    Publication bias arises whenever the probability that a study is published depends on the statistical significance of its results. This bias, often called the file-drawer effect since the unpublished results are imagined to be tucked away in researchers' file cabinets, is potentially a severe impediment to combining the statistical results of studies collected from the literature. With almost any reasonable quantitative model for publication bias, only a small number of studies lost in the file-drawer will produce a significant bias. This result contradicts the well known Fail Safe File Drawer (FSFD) method for setting limits on the potential harm of publication bias, widely used in social, medical and psychic research. This method incorrectly treats the file drawer as unbiased, and almost always miss-estimates the seriousness of publication bias. A large body of not only psychic research, but medical and social science studies, has mistakenly relied on this method to validate claimed discoveries. Statistical combination can be trusted only if it is known with certainty that all studies that have been carried out are included. Such certainty is virtually impossible to achieve in literature surveys.

  15. Publication Bias ( The "File-Drawer Problem") in Scientific Inference

    Science.gov (United States)

    Scargle, Jeffrey D.; DeVincenzi, Donald (Technical Monitor)

    1999-01-01

    Publication bias arises whenever the probability that a study is published depends on the statistical significance of its results. This bias, often called the file-drawer effect since the unpublished results are imagined to be tucked away in researchers' file cabinets, is potentially a severe impediment to combining the statistical results of studies collected from the literature. With almost any reasonable quantitative model for publication bias, only a small number of studies lost in the file-drawer will produce a significant bias. This result contradicts the well known Fail Safe File Drawer (FSFD) method for setting limits on the potential harm of publication bias, widely used in social, medical and psychic research. This method incorrectly treats the file drawer as unbiased, and almost always miss-estimates the seriousness of publication bias. A large body of not only psychic research, but medical and social science studies, has mistakenly relied on this method to validate claimed discoveries. Statistical combination can be trusted only if it is known with certainty that all studies that have been carried out are included. Such certainty is virtually impossible to achieve in literature surveys.

  16. Publication bias in clinical trials of electronic health records.

    Science.gov (United States)

    Vawdrey, David K; Hripcsak, George

    2013-02-01

    To measure the rate of non-publication and assess possible publication bias in clinical trials of electronic health records. We searched ClinicalTrials.gov to identify registered clinical trials of electronic health records and searched the biomedical literature and contacted trial investigators to determine whether the results of the trials were published. Publications were judged as positive, negative, or neutral according to the primary outcome. Seventy-six percent of trials had publications describing trial results; of these, 74% were positive, 21% were neutral, and 4% were negative (harmful). Of unpublished studies for which the investigator responded, 43% were positive, 57% were neutral, and none were negative; the lower rate of positive results was significant (pelectronic health record studies is similar to that in other biomedical studies. There appears to be a bias toward publication of positive trials in this domain. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Publication bias in laboratory animal research: a survey on magnitude, drivers, consequences and potential solutions

    NARCIS (Netherlands)

    Riet, G. ter; Korevaar, D.A.; Leenaars, M.; Sterk, P.J.; Noorden, C.J. van; Bouter, L.M.; Lutter, R.; Oude Elferink, R.P.; Hooft, L.

    2012-01-01

    CONTEXT: Publication bias jeopardizes evidence-based medicine, mainly through biased literature syntheses. Publication bias may also affect laboratory animal research, but evidence is scarce. OBJECTIVES: To assess the opinion of laboratory animal researchers on the magnitude, drivers, consequences a

  18. Investment, managerial capacity, and bias in public health preparedness.

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    Langabeer, James R; DelliFraine, Jami L; Tyson, Sandra; Emert, Jamie M; Herbold, John

    2009-01-01

    Nearly $7 billion has been invested through national cooperative funding since 2002 to strengthen state and local response capacity. Yet, very little outcome evidence exists to analyze funding effectiveness. The objective of this research is to analyze the relationship between investment (funding) and capacity (readiness) for public health preparedness (PHP). The aim of the authors is to use a management framework to evaluate capacity, and to explore the "immediacy bias" impact on investment stability. This study employs a longitudinal study design, incorporating survey research of the entire population of 68 health departments in the state of Texas. The authors assessed the investment-capacity relationship through several statistical methods. The authors created a structural measure of managerial capacity through principal components analysis, factorizing 10 independent variables and augment this with a perceived readiness level reported from PHP managers. The authors then employ analysis of variance, correlation analyses, and other descriptive statistics. There has been a 539 percent coefficient of variation in funding at the local level between the years 2004 and 2008, and a 63 percent reduction in total resources since the peak of funding, using paired sample data. Results suggest that investment is positively associated with readiness and managerial capacity in local health departments. The authors also find that investment was related to greater community collaboration, higher adoption of Incident Command System (ICS) structure, and more frequent operational drills and exercises. Greater investment is associated with higher levels of capacity and readiness. The authors conclude from this that investment should be stabilized and continued, and not be influenced by historical cognitive biases.

  19. Standards, accuracy, and questions of bias in Rorschach meta-analyses: reply to Wood, Garb, Nezworski, Lilienfeld, and Duke (2015).

    Science.gov (United States)

    Mihura, Joni L; Meyer, Gregory J; Bombel, George; Dumitrascu, Nicolae

    2015-01-01

    Wood, Garb, Nezworski, Lilienfeld, and Duke (2015) found our systematic review and meta-analyses of 65 Rorschach variables to be accurate and unbiased, and hence removed their previous recommendation for a moratorium on the applied use of the Rorschach. However, Wood et al. (2015) hypothesized that publication bias would exist for 4 Rorschach variables. To test this hypothesis, they replicated our meta-analyses for these 4 variables and added unpublished dissertations to the pool of articles. In the process, they used procedures that contradicted their standards and recommendations for sound Rorschach research, which consistently led to significantly lower effect sizes. In reviewing their meta-analyses, we found numerous methodological errors, data errors, and omitted studies. In contrast to their strict requirements for interrater reliability in the Rorschach meta-analyses of other researchers, they did not report interrater reliability for any of their coding and classification decisions. In addition, many of their conclusions were based on a narrative review of individual studies and post hoc analyses rather than their meta-analytic findings. Finally, we challenge their sole use of dissertations to test publication bias because (a) they failed to reconcile their conclusion that publication bias was present with the analyses we conducted showing its absence, and (b) we found numerous problems with dissertation study quality. In short, one cannot rely on the findings or the conclusions reported in Wood et al.

  20. Recommendations for a uniform assessment of publication bias related to funding source.

    Science.gov (United States)

    van Lent, Marlies; Overbeke, John; Out, Henk J

    2013-09-30

    Numerous studies on publication bias in clinical drug research have been undertaken, particularly on the association between sponsorship and favourable outcomes. However, no standardized methodology for the classification of outcomes and sponsorship has been described. Dissimilarities and ambiguities in this assessment impede the ability to compare and summarize results of studies on publication bias. To guide authors undertaking such studies, this paper provides recommendations for a uniform assessment of publication bias related to funding source. As part of ongoing research into publication bias, 472 manuscripts on randomised controlled trials (RCTs) with drugs, submitted to eight medical journals from January 2010 through April 2012, were reviewed. Information on trial results and sponsorship was extracted from manuscripts. During the start of this evaluation, several problems related to the classification of outcomes, inclusion of post-hoc analyses and follow-up studies of RCTs in the study sample, and assessment of the role of the funding source were encountered. A comprehensive list of recommendations addressing these problems was composed. To assess internal validity, reliability and usability of these recommendations were tested through evaluation of manuscripts submitted to journals included in our study. The proposed recommendations represent a first step towards a uniform method of classifying trial outcomes and sponsorship. This is essential to draw valid conclusions on the role of the funding source in publication bias and will ensure consistency across future studies.

  1. Will publication bias vanish in the age of online journals?

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    Berlin, J A

    1992-07-08

    A major advantage of online journals, in contrast to printed journals, is that lack of space is not an obstacle. One obvious benefit of this is the ability to include material that might help clarify or emphasize important points, but that might not be considered essential in the context of the limited space available in a printed journal. A more important benefit of removing space constraints is the potential to eliminate publication bias. This bias occurs when a study is not published because it fails to find any statistically significant differences or associations. While authors play a major role in generating this bias, their belief that publication depends on statistical significance has some foundation in the existing printed literature. Nevertheless, realizing the potential to eliminate publication bias depends largely on the willingness of authors to submit their work. The Online Journal of Current Clinical Trials will judge papers on the quality of the work and the importance of the findings, not on the level of statistical significance achieved in any comparisons made. Valuable papers need no longer be turned away simply because of lack of space.

  2. Cognitive advantage in bilingualism: an example of publication bias?

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    de Bruin, Angela; Treccani, Barbara; Della Sala, Sergio

    2015-01-01

    It is a widely held belief that bilinguals have an advantage over monolinguals in executive-control tasks, but is this what all studies actually demonstrate? The idea of a bilingual advantage may result from a publication bias favoring studies with positive results over studies with null or negative effects. To test this hypothesis, we looked at conference abstracts from 1999 to 2012 on the topic of bilingualism and executive control. We then determined which of the studies they reported were subsequently published. Studies with results fully supporting the bilingual-advantage theory were most likely to be published, followed by studies with mixed results. Studies challenging the bilingual advantage were published the least. This discrepancy was not due to differences in sample size, tests used, or statistical power. A test for funnel-plot asymmetry provided further evidence for the existence of a publication bias.

  3. Publication bias and the canonization of false facts

    CERN Document Server

    Nissen, Silas B; Gross, Kevin; Bergstrom, Carl T

    2016-01-01

    In the process of scientific inquiry, certain claims accumulate enough support to be established as facts. Unfortunately, not every claim accorded the status of fact turns out to be true. In this paper, we model the dynamic process by which claims are canonized as fact through repeated experimental confirmation. The community's confidence in a claim constitutes a Markov process: each successive published result shifts the degree of belief, until sufficient evidence accumulates to accept the claim as fact or to reject it as false. In our model, publication bias --- in which positive results are published preferentially over negative ones --- influences the distribution of published results. We find that when readers do not know the degree of publication bias and thus cannot condition on it, false claims often can be canonized as facts. Unless a sufficient fraction of negative results are published, the scientific process will do a poor job at discriminating false from true claims. This problem is exacerbated w...

  4. Measuring the effects of publication bias in political science

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    Justin Esarey

    2016-09-01

    Full Text Available Prior research finds that statistically significant results are overrepresented in scientific publications. If significant results are consistently favored in the review process, published results could systematically overstate the magnitude of their findings even under ideal conditions. In this paper, we measure the impact of this publication bias on political science using a new data set of published quantitative results. Although any measurement of publication bias depends on the prior distribution of empirical relationships, we determine that published estimates in political science are on average substantially larger than their true value under a variety of reasonable choices for this prior. We also find that many published estimates have a false positive probability substantially greater than the conventional α = 0.05 threshold for statistical significance if the prior probability of a null relationship exceeds 50%. Finally, although the proportion of published false positives would be reduced if significance tests used a smaller α, this change would not solve the problem of upward bias in the magnitude of published results.

  5. Exercise as a treatment for depression: A meta-analysis adjusting for publication bias.

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    Schuch, Felipe B; Vancampfort, Davy; Richards, Justin; Rosenbaum, Simon; Ward, Philip B; Stubbs, Brendon

    2016-06-01

    The effects of exercise on depression have been a source of contentious debate. Meta-analyses have demonstrated a range of effect sizes. Both inclusion criteria and heterogeneity may influence the effect sizes reported. The extent and influence of publication bias is also unknown. Randomized controlled trials (RCTs) were identified from a recent Cochrane review and searches of major electronic databases from 01/2013 to 08/2015. We included RCTs of exercise interventions in people with depression (including those with a diagnosis of major depressive disorder (MDD) or ratings on depressive symptoms), comparing exercise versus control conditions. A random effects meta-analysis calculating the standardized mean difference (SMD, 95% confidence interval; CI), meta-regressions, trim and fill and fail-safe n analyses were conducted. Twenty-five RCTs were included comparing exercise versus control comparison groups, including 9 examining participants with MDD. Overall, exercise had a large and significant effect on depression (SMD adjusted for publication bias = 1.11 (95% CI 0.79-1.43)) with a fail-safe number of 1057. Most adjusted analyses suggested publication bias led to an underestimated SMD. Larger effects were found for interventions in MDD, utilising aerobic exercise, at moderate and vigorous intensities, in a supervised and unsupervised format. In MDD, larger effects were found for moderate intensity, aerobic exercise, and interventions supervised by exercise professionals. Exercise has a large and significant antidepressant effect in people with depression (including MDD). Previous meta-analyses may have underestimated the benefits of exercise due to publication bias. Our data strongly support the claim that exercise is an evidence-based treatment for depression.

  6. Misunderstanding publication bias: editors are not blameless after all.

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    Senn, Stephen

    2012-01-01

    In analysing whether there is an editorial bias in favour of positive studies, researchers have made implicit assumptions that are implausible. In particular, to justify the conclusion that there is no bias because observed editorial acceptance rates do not favour positive studies, the assumption that the decision to submit an article is based solely on quality would be required. If, on the other hand, submission were based on perceived probability of acceptance, negative and positive studies would not differ in terms of acceptance rates, but in terms of quality. It is shown, using a simple graphical model, how similar underlying situations as regards the relationship between quality and probability of acceptance on the one hand and study outcome (positive or negative) and probability of acceptance on the other could produce dramatically different results depending on the behaviour of authors. Furthermore, there is, in fact, some evidence that submitted negative studies are, on average, of higher quality than positive ones. This calls into question the standard interpretation of the studies examining editorial bias. It would appear that despite similar probabilities of acceptance for negative and positive studies, editors could be discriminating against negative studies.

  7. Capture-recapture method for assessing publication bias

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    Jalal Poorolajal

    2010-01-01

    Full Text Available

    Background: Publication bias is an important factor that may result in selection bias and lead to overestimation of the intervention effect. Capture recapture method is considered as a potentially useful procedure for investigating and estimating publication bias.

    Methods: We conducted a systematic review to estimate the duration of protection provided by hepatitis B vaccine by measuring the anamnestic immune response to booster doses of vaccine and retrieved studies from three separate sources, including a electronic databases, b reference lists of the studies, and c conference databases as well as contact with experts and manufacturers. Capture recapture and some conventional methods such as funnel plot, Begg test, Egger test, and trim and fill method were employed for assessing publication bias.

    Results: Based on capture recapture method, completeness of the overall search results was 87.2% [95% CI: 84.6% to 89.0%] and log-linear model suggested 5 [95% CI: 4.2 to 6.2] missing studies. The funnel plot was asymmetric but Begg and Egger tests results were

  8. Non-publication and publication bias in reproductive medicine: a cohort analysis.

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    Lensen, S; Jordan, V; Showell, M; Showell, E; Shen, V; Venetis, C; Farquhar, C

    2017-08-01

    Does publication bias or non-publication exist in fertility trials presented as conference abstracts? This study did not detect any publication bias; however, it did identify a high level of non-publication, with only 49% of abstracts reaching full-text publication four or more years after abstract presentation. Systematic reviews of randomized controlled trials (RCTs) are the foundation of evidence based medicine. Non-publication or publication deficit refer to the failure to publish trial results. A publication bias exists when there is any tendency on the parts of the investigators or editors to fail to publish study results on the basis or strength of the study findings. Both present a serious problem for researchers, clinicians and policymakers alike, and ultimately impact on patient care. A retrospective cohort study identified 337 fertility RCTs presented as conference abstracts between 2007 and 2010, as captured by an electronic search of the Cochrane Gynaecology and Fertility Database. After excluding ineligible trials and duplicates, 224 abstracts remained. A search for the full-text papers of each abstract was undertaken in Pubmed, MEDLINE, Embase, CINAHL and Google in May 2015 using a probabilistic approach. Trial authors were contacted to query the publication status of abstracts when no full-text was identified. The association between individual variables and the probability of publication, and time to publication, was assessed using logistic regression and Cox regression, respectively. Of the 224 included abstracts, only 110 (49%; 95% CI: 42.6, 55.6) were found to be published as full-text articles. Publication bias was not identified in this cohort; studies with positive results had a similar probability of reaching full-text publication 52/113 (46%; 95% CI: 37.0, 55.3) as studies with non-positive (negative or null) results 58/111 (52%; 95% CI: 17.8, 33.9) (adjusted odds ratio (AOR): 1.02; 95% CI: 0.53, 1.97). Similarly, the time from abstract

  9. Publication bias and the canonization of false facts.

    Science.gov (United States)

    Nissen, Silas Boye; Magidson, Tali; Gross, Kevin; Bergstrom, Carl T

    2016-12-20

    Science is facing a "replication crisis" in which many experimental findings cannot be replicated and are likely to be false. Does this imply that many scientific facts are false as well? To find out, we explore the process by which a claim becomes fact. We model the community's confidence in a claim as a Markov process with successive published results shifting the degree of belief. Publication bias in favor of positive findings influences the distribution of published results. We find that unless a sufficient fraction of negative results are published, false claims frequently can become canonized as fact. Data-dredging, p-hacking, and similar behaviors exacerbate the problem. Should negative results become easier to publish as a claim approaches acceptance as a fact, however, true and false claims would be more readily distinguished. To the degree that the model reflects the real world, there may be serious concerns about the validity of purported facts in some disciplines.

  10. Reporting Bias in Clinical Trials Investigating the Efficacy of Second-Generation Antidepressants in the Treatment of Anxiety Disorders: A Report of 2 Meta-analyses.

    Science.gov (United States)

    Roest, Annelieke M; de Jonge, Peter; Williams, Craig D; de Vries, Ymkje Anna; Schoevers, Robert A; Turner, Erick H

    2015-05-01

    Studies have shown that the scientific literature has overestimated the efficacy of antidepressants for depression, but other indications for these drugs have not been considered. To examine reporting biases in double-blind, placebo-controlled trials on the pharmacologic treatment of anxiety disorders and quantify the extent to which these biases inflate estimates of drug efficacy. We included reviews obtained from the US Food and Drug Administration (FDA) for premarketing trials of 9 second-generation antidepressants in the treatment of anxiety disorders. A systematic search for matching publications (until December 19, 2012) was performed using PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials. Double data extraction was performed for the FDA reviews and the journal articles. The Hedges g value was calculated as the measure of effect size. Reporting bias was examined and classified as study publication bias, outcome reporting bias, or spin (abstract conclusion not consistent with published results on primary end point). Separate meta-analyses were conducted for the 2 sources, and the effect of publication status on the effect estimates was examined using meta-regression. The findings of 41 of the 57 trials (72%) were positive according to the FDA, but 43 of the 45 published article conclusions (96%) were positive (P antidepressants for anxiety disorders. Although these biases did not significantly inflate estimates of drug efficacy, reporting biases led to significant increases in the number of positive findings in the literature.

  11. Too good to be true: publication bias in two prominent studies from experimental psychology.

    Science.gov (United States)

    Francis, Gregory

    2012-04-01

    Empirical replication has long been considered the final arbiter of phenomena in science, but replication is undermined when there is evidence for publication bias. Evidence for publication bias in a set of experiments can be found when the observed number of rejections of the null hypothesis exceeds the expected number of rejections. Application of this test reveals evidence of publication bias in two prominent investigations from experimental psychology that have purported to reveal evidence of extrasensory perception and to indicate severe limitations of the scientific method. The presence of publication bias suggests that those investigations cannot be taken as proper scientific studies of such phenomena, because critical data are not available to the field. Publication bias could partly be avoided if experimental psychologists started using Bayesian data analysis techniques.

  12. A hydrologic drying bias in water-resource impact analyses of anthropogenic climate change

    Science.gov (United States)

    Milly, Paul; Dunne, Krista A.

    2017-01-01

    For water-resource planning, sensitivity of freshwater availability to anthropogenic climate change (ACC) often is analyzed with “offline” hydrologic models that use precipitation and potential evapotranspiration (Ep) as inputs. Because Ep is not a climate-model output, an intermediary model of Ep must be introduced to connect the climate model to the hydrologic model. Several Ep methods are used. The suitability of each can be assessed by noting a credible Ep method for offline analyses should be able to reproduce climate models’ ACC-driven changes in actual evapotranspiration in regions and seasons of negligible water stress (Ew). We quantified this ability for seven commonly used Ep methods and for a simple proportionality with available energy (“energy-only” method). With the exception of the energy-only method, all methods tend to overestimate substantially the increase in Ep associated with ACC. In an offline hydrologic model, the Ep-change biases produce excessive increases in actual evapotranspiration (E), whether the system experiences water stress or not, and thence strong negative biases in runoff change, as compared to hydrologic fluxes in the driving climate models. The runoff biases are comparable in magnitude to the ACC-induced runoff changes themselves. These results suggest future hydrologic drying (wetting) trends likely are being systematically and substantially overestimated (underestimated) in many water-resource impact analyses.

  13. Which metaproteome? The impact of protein extraction bias on metaproteomic analyses.

    Science.gov (United States)

    Leary, Dagmar Hajkova; Hervey, W Judson; Deschamps, Jeffrey R; Kusterbeck, Anne W; Vora, Gary J

    2013-01-01

    Culture-independent techniques such as LC-MS/MS-based metaproteomic analyses are being increasingly utilized for the study of microbial composition and function in complex environmental samples. Although several studies have documented the many challenges and sources of bias that must be considered in these types of analyses, none have systematically characterized the effect of protein extraction bias on the biological interpretation of true environmental biofilm metaproteomes. In this study, we compared three protein extraction methods commonly used in the analyses of environmental samples [guanidine hydrochloride (GuHCl), B-PER, sequential citrate-phenol (SCP)] using nano-LC-MS/MS and an environmental marine biofilm to determine the unique biases introduced by each method and their effect on the interpretation of the derived metaproteomes. While the protein extraction efficiencies of the three methods ranged from 2.0 to 4.3%, there was little overlap in the sequence (1.9%), function (8.3% of total assigned protein families) and origin of the identified proteins from each extract. Each extraction method enriched for different protein families (GuHCl - photosynthesis, carbohydrate metabolism; B-PER - membrane transport, oxidative stress; SCP - calcium binding, structural) while 23.7-45.4% of the identified proteins lacked SwissProt annotations. Taken together, the results demonstrated that even the most basic interpretations of this complex microbial assemblage (species composition, ratio of prokaryotic to eukaryotic proteins, predominant functions) varied with little overlap based on the protein extraction method employed. These findings demonstrate the heavy influence of protein extraction on biofilm metaproteomics and provide caveats for the interpretation of such data sets when utilizing single protein extraction methods for the description of complex microbial assemblages.

  14. Reprint of "Which metaproteome? The impact of protein extraction bias on metaproteomic analyses".

    Science.gov (United States)

    Leary, Dagmar Hajkova; Hervey, W Judson; Deschamps, Jeffrey R; Kusterbeck, Anne W; Vora, Gary J

    2014-01-01

    Culture-independent techniques such as LC-MS/MS-based metaproteomic analyses are being increasingly utilized for the study of microbial composition and function in complex environmental samples. Although several studies have documented the many challenges and sources of bias that must be considered in these types of analyses, none have systematically characterized the effect of protein extraction bias on the biological interpretation of true environmental biofilm metaproteomes. In this study, we compared three protein extraction methods commonly used in the analyses of environmental samples [guanidine hydrochloride (GuHCl), B-PER, sequential citrate-phenol (SCP)] using nano-LC-MS/MS and an environmental marine biofilm to determine the unique biases introduced by each method and their effect on the interpretation of the derived metaproteomes. While the protein extraction efficiencies of the three methods ranged from 2.0 to 4.3%, there was little overlap in the sequence (1.9%), function (8.3% of total assigned protein families) and origin of the identified proteins from each extract. Each extraction method enriched for different protein families (GuHCl--photosynthesis, carbohydrate metabolism; B-PER--membrane transport, oxidative stress; SCP--calcium binding, structural) while 23.7-45.4% of the identified proteins lacked SwissProt annotations. Taken together, the results demonstrated that even the most basic interpretations of this complex microbial assemblage (species composition, ratio of prokaryotic to eukaryotic proteins, predominant functions) varied with little overlap based on the protein extraction method employed. These findings demonstrate the heavy influence of protein extraction on biofilm metaproteomics and provide caveats for the interpretation of such data sets when utilizing single protein extraction methods for the description of complex microbial assemblages.

  15. Analyses of eigenvalue bias and control rod worths in FFTF (Fast Flux Test Facility)

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, J.V.; Dobbin, K.D.; Wootan, D.W.; Campbell, L.R.

    1987-01-01

    The Fast Flux Test Facility (FFTF) core loading during its ninth operating cycle was significantly different from that of previous cycles because of the presence of the Core Demonstration Experiment (CDE). The CDE consists of a number of axially blanketed fuel assemblies and internal blankets prototypic of advanced oxide cores in Liquid Metal Reactors (LMR). In preparation for the Cycle 9 reload design effort, a careful assessment of control rod worth and reactivity calculations for Cycles 1 through 8 was made. The goal of this study was to establish calculational biases and reduce uncertainties factored into the reload design calculations. These analyses helped assure that the operational objectives for Cycle 9 were met.

  16. Social conformity is due to biased stimulus processing: electrophysiological and diffusion analyses.

    Science.gov (United States)

    Germar, Markus; Albrecht, Thorsten; Voss, Andreas; Mojzisch, Andreas

    2016-09-01

    Hundreds of studies have found that humans' decisions are strongly influenced by the opinions of others, even when making simple perceptual decisions. In this study, we aimed to clarify whether this effect can be explained by social influence biasing (early) perceptual processes. We employed stimulus evoked potentials, lateralized readiness potentials (LRPs) and a diffusion model analysis of reaction time data to uncover the neurocognitive processes underlying social conformity in perceptual decision-making. The diffusion model analysis showed that social conformity was due to a biased uptake of stimulus information and accompanied by more careful stimulus processing. As indicated by larger N1-amplitudes, social influence increased early attentional resources for stimulus identification and discrimination. Furthermore, LRP analyses revealed that stimulus processing was biased even in cases of non-conformity. In conclusion, our results suggest that the opinion of others can cause individuals to selectively process stimulus information supporting this opinion, thereby inducing social conformity. This effect is present even when individuals do not blindly follow the majority but rather carefully process stimulus information.

  17. GENDER BIAS IN THE PUBLIC RELATIONS INDUSTRY IN MALAYSIA: COMPARING PUBLIC RELATIONS PRACTITIONERS’ JOB FUNCTIONS, INCOMES, AND CAREER PROSPECTS

    OpenAIRE

    Yesuselvi Manickam; Tan Soon Chin; Suffian Hadi Ayub

    2016-01-01

    Today, there is an increase in women working outside their home to sustain themselves economically and socially, but the working experiences can be problematic for women when gender discrimination exists in the workplace. In the early 1960s, women were entering the public relations industry at a rate faster than their male counterparts, but gender bias was a sore issue in the industry. Numerous studies have been conducted on gender bias, and the findings indicate that female public relations ...

  18. Inadequate use and regulation of interventions against publication bias decreases their effectiveness: a systematic review

    Science.gov (United States)

    Thaler, Kylie; Kien, Christina; Nussbaumer, Barbara; Van Noord, Megan G.; Griebler, Ursula; Klerings, Irma; Gartlehner, Gerald

    2015-01-01

    Objectives To determine the effectiveness of interventions designed to prevent or reduce publication and related biases. Study Design and Setting We searched multiple databases and performed manual searches using terms related to publication bias and known interventions against publication bias. We dually reviewed citations and assessed risk of bias. We synthesized results by intervention and outcomes measured and graded the quality of the evidence (QoE). Results We located 38 eligible studies. The use of prospective trial registries (PTR) has increased since 2005 (seven studies, moderate QoE); however, positive outcome-reporting bias is prevalent (14 studies, low QoE), and information in nonmandatory fields is vague (10 studies, low QoE). Disclosure of financial conflict of interest (CoI) is inadequate (five studies, low QoE). Blinding peer reviewers may reduce geographical bias (two studies, very low QoE), and open-access publishing does not discriminate against authors from low-income countries (two studies, very low QoE). Conclusion The use of PTR and CoI disclosures is increasing; however, the adequacy of their use requires improvement. The effect of open-access publication and blinding of peer reviewers on publication bias is unclear, as is the effect of other interventions such as electronic publication and authors' rights to publish their results. PMID:25835490

  19. Possible Solution to Publication Bias Through Bayesian Statistics, Including Proper Null Hypothesis Testing

    NARCIS (Netherlands)

    Konijn, Elly A.; van de Schoot, Rens; Winter, Sonja D.; Ferguson, Christopher J.

    2015-01-01

    The present paper argues that an important cause of publication bias resides in traditional frequentist statistics forcing binary decisions. An alternative approach through Bayesian statistics provides various degrees of support for any hypothesis allowing balanced decisions and proper null hypothes

  20. Detecting and correcting for publication bias in meta-analysis - A truncated normal distribution approach.

    Science.gov (United States)

    Zhu, Qiaohao; Carriere, K C

    2016-01-01

    Publication bias can significantly limit the validity of meta-analysis when trying to draw conclusion about a research question from independent studies. Most research on detection and correction for publication bias in meta-analysis focus mainly on funnel plot-based methodologies or selection models. In this paper, we formulate publication bias as a truncated distribution problem, and propose new parametric solutions. We develop methodologies of estimating the underlying overall effect size and the severity of publication bias. We distinguish the two major situations, in which publication bias may be induced by: (1) small effect size or (2) large p-value. We consider both fixed and random effects models, and derive estimators for the overall mean and the truncation proportion. These estimators will be obtained using maximum likelihood estimation and method of moments under fixed- and random-effects models, respectively. We carried out extensive simulation studies to evaluate the performance of our methodology, and to compare with the non-parametric Trim and Fill method based on funnel plot. We find that our methods based on truncated normal distribution perform consistently well, both in detecting and correcting publication bias under various situations.

  1. Potential sources of analytical bias and error in selected trace element data-quality analyses

    Science.gov (United States)

    Paul, Angela P.; Garbarino, John R.; Olsen, Lisa D.; Rosen, Michael R.; Mebane, Christopher A.; Struzeski, Tedmund M.

    2016-09-28

    Potential sources of analytical bias and error associated with laboratory analyses for selected trace elements where concentrations were greater in filtered samples than in paired unfiltered samples were evaluated by U.S. Geological Survey (USGS) Water Quality Specialists in collaboration with the USGS National Water Quality Laboratory (NWQL) and the Branch of Quality Systems (BQS).Causes for trace-element concentrations in filtered samples to exceed those in associated unfiltered samples have been attributed to variability in analytical measurements, analytical bias, sample contamination either in the field or laboratory, and (or) sample-matrix chemistry. These issues have not only been attributed to data generated by the USGS NWQL but have been observed in data generated by other laboratories. This study continues the evaluation of potential analytical bias and error resulting from matrix chemistry and instrument variability by evaluating the performance of seven selected trace elements in paired filtered and unfiltered surface-water and groundwater samples collected from 23 sampling sites of varying chemistries from six States, matrix spike recoveries, and standard reference materials.Filtered and unfiltered samples have been routinely analyzed on separate inductively coupled plasma-mass spectrometry instruments. Unfiltered samples are treated with hydrochloric acid (HCl) during an in-bottle digestion procedure; filtered samples are not routinely treated with HCl as part of the laboratory analytical procedure. To evaluate the influence of HCl on different sample matrices, an aliquot of the filtered samples was treated with HCl. The addition of HCl did little to differentiate the analytical results between filtered samples treated with HCl from those samples left untreated; however, there was a small, but noticeable, decrease in the number of instances where a particular trace-element concentration was greater in a filtered sample than in the associated

  2. GENDER BIAS IN THE PUBLIC RELATIONS INDUSTRY IN MALAYSIA: COMPARING PUBLIC RELATIONS PRACTITIONERS’ JOB FUNCTIONS, INCOMES, AND CAREER PROSPECTS

    Directory of Open Access Journals (Sweden)

    Yesuselvi Manickam

    2016-12-01

    Full Text Available Today, there is an increase in women working outside their home to sustain themselves economically and socially, but the working experiences can be problematic for women when gender discrimination exists in the workplace. In the early 1960s, women were entering the public relations industry at a rate faster than their male counterparts, but gender bias was a sore issue in the industry. Numerous studies have been conducted on gender bias, and the findings indicate that female public relations practitioners receive unequal treatment in their organisation. For that reason, this study investigated whether gender bias exists in the public relations industry in Klang Valley, Malaysia, and if so, what the impact was on the practitioners’ work performance. The study used an in-depth interview with five public relations practitioners from public relations agencies and corporate companies. Feminist Standpoint Theory served as a framework for this study. Results revealed that in Malaysia, gender bias is not prevalent because of cultural diversity and company policies. The priorities of these public relations agencies and organisations favor employee’s performance and competence over gender. The results also indicated that public relations practitioners are treated fairly in areas of career prospects, job functions, and remuneration.

  3. Publication bias in laboratory animal research: a survey on magnitude, drivers, consequences and potential solutions.

    Directory of Open Access Journals (Sweden)

    Gerben ter Riet

    Full Text Available CONTEXT: Publication bias jeopardizes evidence-based medicine, mainly through biased literature syntheses. Publication bias may also affect laboratory animal research, but evidence is scarce. OBJECTIVES: To assess the opinion of laboratory animal researchers on the magnitude, drivers, consequences and potential solutions for publication bias. And to explore the impact of size of the animals used, seniority of the respondent, working in a for-profit organization and type of research (fundamental, pre-clinical, or both on those opinions. DESIGN: Internet-based survey. SETTING: All animal laboratories in The Netherlands. PARTICIPANTS: Laboratory animal researchers. MAIN OUTCOME MEASURE(S: Median (interquartile ranges strengths of beliefs on 5 and 10-point scales (1: totally unimportant to 5 or 10: extremely important. RESULTS: Overall, 454 researchers participated. They considered publication bias a problem in animal research (7 (5 to 8 and thought that about 50% (32-70 of animal experiments are published. Employees (n = 21 of for-profit organizations estimated that 10% (5 to 50 are published. Lack of statistical significance (4 (4 to 5, technical problems (4 (3 to 4, supervisors (4 (3 to 5 and peer reviewers (4 (3 to 5 were considered important reasons for non-publication (all on 5-point scales. Respondents thought that mandatory publication of study protocols and results, or the reasons why no results were obtained, may increase scientific progress but expected increased bureaucracy. These opinions did not depend on size of the animal used, seniority of the respondent or type of research. CONCLUSIONS: Non-publication of "negative" results appears to be prevalent in laboratory animal research. If statistical significance is indeed a main driver of publication, the collective literature on animal experimentation will be biased. This will impede the performance of valid literature syntheses. Effective, yet efficient systems should be explored to

  4. Potential sources of analytical bias and error in selected trace element data-quality analyses

    Science.gov (United States)

    Paul, Angela P.; Garbarino, John R.; Olsen, Lisa D.; Rosen, Michael R.; Mebane, Christopher A.; Struzeski, Tedmund M.

    2016-09-28

    Potential sources of analytical bias and error associated with laboratory analyses for selected trace elements where concentrations were greater in filtered samples than in paired unfiltered samples were evaluated by U.S. Geological Survey (USGS) Water Quality Specialists in collaboration with the USGS National Water Quality Laboratory (NWQL) and the Branch of Quality Systems (BQS).Causes for trace-element concentrations in filtered samples to exceed those in associated unfiltered samples have been attributed to variability in analytical measurements, analytical bias, sample contamination either in the field or laboratory, and (or) sample-matrix chemistry. These issues have not only been attributed to data generated by the USGS NWQL but have been observed in data generated by other laboratories. This study continues the evaluation of potential analytical bias and error resulting from matrix chemistry and instrument variability by evaluating the performance of seven selected trace elements in paired filtered and unfiltered surface-water and groundwater samples collected from 23 sampling sites of varying chemistries from six States, matrix spike recoveries, and standard reference materials.Filtered and unfiltered samples have been routinely analyzed on separate inductively coupled plasma-mass spectrometry instruments. Unfiltered samples are treated with hydrochloric acid (HCl) during an in-bottle digestion procedure; filtered samples are not routinely treated with HCl as part of the laboratory analytical procedure. To evaluate the influence of HCl on different sample matrices, an aliquot of the filtered samples was treated with HCl. The addition of HCl did little to differentiate the analytical results between filtered samples treated with HCl from those samples left untreated; however, there was a small, but noticeable, decrease in the number of instances where a particular trace-element concentration was greater in a filtered sample than in the associated

  5. Genes with minimal phylogenetic information are problematic for coalescent analyses when gene tree estimation is biased.

    Science.gov (United States)

    Xi, Zhenxiang; Liu, Liang; Davis, Charles C

    2015-11-01

    The development and application of coalescent methods are undergoing rapid changes. One little explored area that bears on the application of gene-tree-based coalescent methods to species tree estimation is gene informativeness. Here, we investigate the accuracy of these coalescent methods when genes have minimal phylogenetic information, including the implementation of the multilocus bootstrap approach. Using simulated DNA sequences, we demonstrate that genes with minimal phylogenetic information can produce unreliable gene trees (i.e., high error in gene tree estimation), which may in turn reduce the accuracy of species tree estimation using gene-tree-based coalescent methods. We demonstrate that this problem can be alleviated by sampling more genes, as is commonly done in large-scale phylogenomic analyses. This applies even when these genes are minimally informative. If gene tree estimation is biased, however, gene-tree-based coalescent analyses will produce inconsistent results, which cannot be remedied by increasing the number of genes. In this case, it is not the gene-tree-based coalescent methods that are flawed, but rather the input data (i.e., estimated gene trees). Along these lines, the commonly used program PhyML has a tendency to infer one particular bifurcating topology even though it is best represented as a polytomy. We additionally corroborate these findings by analyzing the 183-locus mammal data set assembled by McCormack et al. (2012) using ultra-conserved elements (UCEs) and flanking DNA. Lastly, we demonstrate that when employing the multilocus bootstrap approach on this 183-locus data set, there is no strong conflict between species trees estimated from concatenation and gene-tree-based coalescent analyses, as has been previously suggested by Gatesy and Springer (2014).

  6. Publication bias in reports of animal stroke studies leads to major overstatement of efficacy.

    Directory of Open Access Journals (Sweden)

    Emily S Sena

    2010-03-01

    Full Text Available The consolidation of scientific knowledge proceeds through the interpretation and then distillation of data presented in research reports, first in review articles and then in textbooks and undergraduate courses, until truths become accepted as such both amongst "experts" and in the public understanding. Where data are collected but remain unpublished, they cannot contribute to this distillation of knowledge. If these unpublished data differ substantially from published work, conclusions may not reflect adequately the underlying biological effects being described. The existence and any impact of such "publication bias" in the laboratory sciences have not been described. Using the CAMARADES (Collaborative Approach to Meta-analysis and Review of Animal Data in Experimental Studies database we identified 16 systematic reviews of interventions tested in animal studies of acute ischaemic stroke involving 525 unique publications. Only ten publications (2% reported no significant effects on infarct volume and only six (1.2% did not report at least one significant finding. Egger regression and trim-and-fill analysis suggested that publication bias was highly prevalent (present in the literature for 16 and ten interventions, respectively in animal studies modelling stroke. Trim-and-fill analysis suggested that publication bias might account for around one-third of the efficacy reported in systematic reviews, with reported efficacy falling from 31.3% to 23.8% after adjustment for publication bias. We estimate that a further 214 experiments (in addition to the 1,359 identified through rigorous systematic review; non publication rate 14% have been conducted but not reported. It is probable that publication bias has an important impact in other animal disease models, and more broadly in the life sciences.

  7. Social science. Publication bias in the social sciences: unlocking the file drawer.

    Science.gov (United States)

    Franco, Annie; Malhotra, Neil; Simonovits, Gabor

    2014-09-19

    We studied publication bias in the social sciences by analyzing a known population of conducted studies--221 in total--in which there is a full accounting of what is published and unpublished. We leveraged Time-sharing Experiments in the Social Sciences (TESS), a National Science Foundation-sponsored program in which researchers propose survey-based experiments to be run on representative samples of American adults. Because TESS proposals undergo rigorous peer review, the studies in the sample all exceed a substantial quality threshold. Strong results are 40 percentage points more likely to be published than are null results and 60 percentage points more likely to be written up. We provide direct evidence of publication bias and identify the stage of research production at which publication bias occurs: Authors do not write up and submit null findings.

  8. Detecting Bias in Meta-Analyses of Distance Education Research: Big Pictures We Can Rely On

    Science.gov (United States)

    Bernard, Robert M.; Borokhovski, Eugene; Tamim, Rana M.

    2014-01-01

    This article has two interrelated purposes. The first is to explain how various forms of bias, if introduced during any stage of a meta-analysis, can provide the consumer with a misimpression of the state of a research literature. Five of the most important bias-producing aspects of a meta-analysis are presented and discussed. Second, armed with…

  9. How does cognitive bias modification affect anxiety? Mediation analyses and experimental data

    NARCIS (Netherlands)

    Salemink, E.; van den Hout, M.; Kindt, M.

    2010-01-01

    Background: There is overwhelming evidence that anxiety is associated with the tendency to interpret information negatively. The causal relationship between this interpretive bias and anxiety has been examined by modifying interpretive bias and examining effects on anxiety. A crucial assumption is t

  10. Students' Race and Teachers' Social Support Affect the Positive Feedback Bias in Public Schools

    Science.gov (United States)

    Harber, Kent D.; Gorman, Jamie L.; Gengaro, Frank P.; Butisingh, Samantha; Tsang, William; Ouellette, Rebecca

    2012-01-01

    This research tested whether public school teachers display the positive feedback bias, wherein Whites give more praise and less criticism to minorities than to fellow Whites for equivalent work. It also tested whether teachers lacking in school-based social support (i.e., support from fellow teachers and school administrators) are more likely to…

  11. What happened to Popperian falsification? Publishing neutral and negative findings : Moving away from biased publication practices

    NARCIS (Netherlands)

    van Witteloostuijn, Arjen

    2016-01-01

    Purpose – Current publication practices in the scholarly (International) Business and Management community are overwhelmingly anti-Popperian, which fundamentally frustrates the production of scientific progress. This is the result of at least five related biases: the verification, novelty, normal sc

  12. What happened to Popperian falsification? Publishing neutral and negative findings : Moving away from biased publication practices

    NARCIS (Netherlands)

    van Witteloostuijn, Arjen

    2016-01-01

    Purpose – Current publication practices in the scholarly (International) Business and Management community are overwhelmingly anti-Popperian, which fundamentally frustrates the production of scientific progress. This is the result of at least five related biases: the verification, novelty, normal sc

  13. 'Jumping to conclusions' data-gathering bias in psychosis and other psychiatric disorders - Two meta-analyses of comparisons between patients and healthy individuals.

    Science.gov (United States)

    So, Suzanne Ho-Wai; Siu, Nicolson Yat-Fan; Wong, Hau-Lam; Chan, Wai; Garety, Philippa Anne

    2016-06-01

    There has been an increase in attention to studying shared mechanisms underlying psychiatric disorders. The 'Jumping to conclusions' (JTC(1)) bias, a tendency to make decisions with certainty based on insufficient information, has been reported in patients with psychosis, and process-based treatment protocols targeting this bias have recently been developed. This review aimed to investigate to what extent the JTC bias, measured by various tasks, is associated with psychotic disorders and other psychiatric disorders using a meta-analytic approach. We examined 6864 articles published between 1990 and 2015, and meta-analysed 46 studies. The first meta-analysis included 40 effect sizes comparing patients with schizophrenia spectrum or other psychotic disorders and healthy controls. There was a hastier data-gathering style in patients with psychosis than healthy individuals, with a moderate aggregated effect size. The second meta-analysis included 18 effect sizes comparing patients with non-psychotic disorders and healthy controls. There was marked heterogeneity in effect sizes and evidence for publication bias. After removal of outliers, the aggregated effect size for JTC was not statistically significant. A planned subgroup analysis showed no significant effect of JTC in depression. Other diagnostic subgroups yielded small non-significant results. Therefore, our findings do not support the suggestion that JTC is a transdiagnostic phenomenon beyond psychosis.

  14. Preoperative Breast MRI: Surgeons' Patient Selection Patterns and Potential Bias in Outcomes Analyses.

    Science.gov (United States)

    Lee, Jiyon; Tanaka, Elaine; Eby, Peter R; Zhou, Shouhao; Wei, Wei; Eppelheimer, Christine; Loving, Vilert A

    2017-04-01

    = 0.01) and tumors smaller than 1 cm (mean Likert score, 3.84 vs 3.40; p = 0.002). Breast surgeons referred less often than did general surgeons for multifocal or multicentric disease (mean Likert score, 5.02 vs 5.44; p = 0.001). Breast surgeons and general surgeons similarly weighed other variables. Preoperative breast MRI referral trended with certain higher risk patient- and tumor-related and clinical variables and were nonuniform between the breast surgeons and general surgeon cohorts. Selection bias could affect outcomes analyses for preoperative breast MRI.

  15. Exercise for depression in older adults: a meta-analysis of randomized controlled trials adjusting for publication bias

    Directory of Open Access Journals (Sweden)

    Felipe B. Schuch

    Full Text Available Objective: To evaluate the antidepressant effects of exercise in older adults, using randomized controlled trial (RCT data. Methods: We conducted a meta-analysis of exercise in older adults, addressing limitations of previous works. RCTs of exercise interventions in older people with depression (≥ 60 years comparing exercise vs. control were eligible. A random-effects meta-analysis calculating the standardized mean difference (SMD (95% confidence interval [95%CI], meta-regressions, and trim, fill, and fail-safe number analyses were conducted. Results: Eight RCTs were included, representing 138 participants in exercise arms and 129 controls. Exercise had a large and significant effect on depression (SMD = -0.90 [95%CI -0.29 to -1.51], with a fail-safe number of 71 studies. Significant effects were found for 1 mixed aerobic and anaerobic interventions, 2 at moderate intensity, 3 that were group-based, 4 that utilized mixed supervised and unsupervised formats, and 5 in people without other clinical comorbidities. Conclusion: Adjusting for publication bias increased the beneficial effects of exercise in three subgroup analysis, suggesting that previous meta-analyses have underestimated the benefits of exercise due to publication bias. We advocate that exercise be considered as a routine component of the management of depression in older adults.

  16. Propagation of Isotopic Bias and Uncertainty to Criticality Safety Analyses of PWR Waste Packages

    Energy Technology Data Exchange (ETDEWEB)

    Radulescu, Georgeta [ORNL

    2010-06-01

    Burnup credit methodology is economically advantageous because significantly higher loading capacity may be achieved for spent nuclear fuel (SNF) casks based on this methodology as compared to the loading capacity based on a fresh fuel assumption. However, the criticality safety analysis for establishing the loading curve based on burnup credit becomes increasingly complex as more parameters accounting for spent fuel isotopic compositions are introduced to the safety analysis. The safety analysis requires validation of both depletion and criticality calculation methods. Validation of a neutronic-depletion code consists of quantifying the bias and the uncertainty associated with the bias in predicted SNF compositions caused by cross-section data uncertainty and by approximations in the calculational method. The validation is based on comparison between radiochemical assay (RCA) data and calculated isotopic concentrations for fuel samples representative of SNF inventory. The criticality analysis methodology for commercial SNF disposal allows burnup credit for 14 actinides and 15 fission product isotopes in SNF compositions. The neutronic-depletion method for disposal criticality analysis employing burnup credit is the two-dimensional (2-D) depletion sequence TRITON (Transport Rigor Implemented with Time-dependent Operation for Neutronic depletion)/NEWT (New ESC-based Weighting Transport code) and the 44GROUPNDF5 crosssection library in the Standardized Computer Analysis for Licensing Evaluation (SCALE 5.1) code system. The SCALE 44GROUPNDF5 cross section library is based on the Evaluated Nuclear Data File/B Version V (ENDF/B-V) library. The criticality calculation code for disposal criticality analysis employing burnup credit is General Monte Carlo N-Particle (MCNP) Transport Code. The purpose of this calculation report is to determine the bias on the calculated effective neutron multiplication factor, k{sub eff}, due to the bias and bias uncertainty associated with

  17. Bias analysis applied to Agricultural Health Study publications to estimate non-random sources of uncertainty

    Directory of Open Access Journals (Sweden)

    Lash Timothy L

    2007-11-01

    qualitative description of study limitations. The latter approach is likely to lead to overconfidence regarding the potential for causal associations, whereas the former safeguards against such overinterpretations. Furthermore, such analyses, once programmed, allow rapid implementation of alternative assignments of probability distributions to the bias parameters, so elevate the plane of discussion regarding study bias from characterizing studies as "valid" or "invalid" to a critical and quantitative discussion of sources of uncertainty.

  18. Publication bias in "Red, rank, and romance in women viewing men," by Elliot et al. (2010).

    Science.gov (United States)

    Francis, Gregory

    2013-02-01

    Elliot et al. (2010) reported multiple experimental findings that the color red modified women's ratings of attractiveness, sexual desirability, and status of a photographed man. An analysis of the reported statistics of these studies indicates that the experiments lack sufficient power to support these claims. Given the power of the experiments, the probability that the observed 12 findings would all reject the null hypothesis is only .005. Thus, the proper interpretation of the findings is that the studies are contaminated with publication bias. Either some experiments with null findings were not reported or the reported experiments were run improperly in a way that inflated the likelihood of rejecting the null hypothesis. Because of the presence of publication bias, the findings in Elliot et al. (2010) should be considered nonscientific or anecdotal. It remains an open question whether the color red influences women's ratings of men's attributes. 2013 APA, all rights reserved

  19. The VIMOS Public Extragalactic Redshift Survey (VIPERS). Measuring non-linear galaxy bias at z ~ 0.8

    Science.gov (United States)

    Di Porto, C.; Branchini, E.; Bel, J.; Marulli, F.; Bolzonella, M.; Cucciati, O.; de la Torre, S.; Granett, B. R.; Guzzo, L.; Marinoni, C.; Moscardini, L.; Abbas, U.; Adami, C.; Arnouts, S.; Bottini, D.; Cappi, A.; Coupon, J.; Davidzon, I.; De Lucia, G.; Fritz, A.; Franzetti, P.; Fumana, M.; Garilli, B.; Ilbert, O.; Iovino, A.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; McCracken, H. J.; Paioro, L.; Polletta, M.; Pollo, A.; Scodeggio, M.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.; Burden, A.; Marchetti, A.; Martizzi, D.; Mellier, Y.; Nichol, R. C.; Peacock, J. A.; Percival, W. J.; Viel, M.; Wolk, M.; Zamorani, G.

    2016-10-01

    Aims: We use the first release of the VImos Public Extragalactic Redshift Survey of galaxies (VIPERS) of ~50 000 objects to measure the biasing relation between galaxies and mass in the redshift range z = [ 0.5,1.1 ]. Methods: We estimate the 1-point distribution function [PDF] of VIPERS galaxies from counts in cells and, assuming a model for the mass PDF, we infer their mean bias relation. The reconstruction of the bias relation is performed through a novel method that accounts for Poisson noise, redshift distortions, inhomogeneous sky coverage. and other selection effects. With this procedure we constrain galaxy bias and its deviations from linearity down to scales as small as 4 h-1 Mpc and out to z = 1.1. Results: We detect small (up to 2%) but statistically significant (up to 3σ) deviations from linear bias. The mean biasing function is close to linear in regions above the mean density. The mean slope of the biasing relation is a proxy to the linear bias parameter. This slope increases with luminosity, which is in agreement with results of previous analyses. We detect a strong bias evolution only for z> 0.9, which is in agreement with some, but not all, previous studies. We also detect a significant increase of the bias with the scale, from 4 to 8 h-1 Mpc , now seen for the first time out to z = 1. The amplitude of non-linearity depends on redshift, luminosity, and scale, but no clear trend is detected. Owing to the large cosmic volume probed by VIPERS, we find that the mismatch between the previous estimates of bias at z ~ 1 from zCOSMOS and VVDS-Deep galaxy samples is fully accounted for by cosmic variance. Conclusions: The results of our work confirm the importance of going beyond the over-simplistic linear bias hypothesis showing that non-linearities can be accurately measured through the applications of the appropriate statistical tools to existing datasets like VIPERS. Based on observations collected at the European Southern Observatory, Paranal, Chile

  20. A selection model for accounting for publication bias in a full network meta-analysis.

    Science.gov (United States)

    Mavridis, Dimitris; Welton, Nicky J; Sutton, Alex; Salanti, Georgia

    2014-12-30

    Copas and Shi suggested a selection model to explore the potential impact of publication bias via sensitivity analysis based on assumptions for the probability of publication of trials conditional on the precision of their results. Chootrakool et al. extended this model to three-arm trials but did not fully account for the implications of the consistency assumption, and their model is difficult to generalize for complex network structures with more than three treatments. Fitting these selection models within a frequentist setting requires maximization of a complex likelihood function, and identification problems are common. We have previously presented a Bayesian implementation of the selection model when multiple treatments are compared with a common reference treatment. We now present a general model suitable for complex, full network meta-analysis that accounts for consistency when adjusting results for publication bias. We developed a design-by-treatment selection model to describe the mechanism by which studies with different designs (sets of treatments compared in a trial) and precision may be selected for publication. We fit the model in a Bayesian setting because it avoids the numerical problems encountered in the frequentist setting, it is generalizable with respect to the number of treatments and study arms, and it provides a flexible framework for sensitivity analysis using external knowledge. Our model accounts for the additional uncertainty arising from publication bias more successfully compared to the standard Copas model or its previous extensions. We illustrate the methodology using a published triangular network for the failure of vascular graft or arterial patency.

  1. Effect of reporting bias on meta-analyses of drug trials

    DEFF Research Database (Denmark)

    Hart, Beth; Lundh, Andreas; Bero, Lisa

    2012-01-01

    To investigate the effect of including unpublished trial outcome data obtained from the Food and Drug Administration (FDA) on the results of meta-analyses of drug trials.......To investigate the effect of including unpublished trial outcome data obtained from the Food and Drug Administration (FDA) on the results of meta-analyses of drug trials....

  2. Publication bias in psychology: a diagnosis based on the correlation between effect size and sample size.

    Directory of Open Access Journals (Sweden)

    Anton Kühberger

    Full Text Available The p value obtained from a significance test provides no information about the magnitude or importance of the underlying phenomenon. Therefore, additional reporting of effect size is often recommended. Effect sizes are theoretically independent from sample size. Yet this may not hold true empirically: non-independence could indicate publication bias.We investigate whether effect size is independent from sample size in psychological research. We randomly sampled 1,000 psychological articles from all areas of psychological research. We extracted p values, effect sizes, and sample sizes of all empirical papers, and calculated the correlation between effect size and sample size, and investigated the distribution of p values.We found a negative correlation of r = -.45 [95% CI: -.53; -.35] between effect size and sample size. In addition, we found an inordinately high number of p values just passing the boundary of significance. Additional data showed that neither implicit nor explicit power analysis could account for this pattern of findings.The negative correlation between effect size and samples size, and the biased distribution of p values indicate pervasive publication bias in the entire field of psychology.

  3. Publication Bias in Psychology: A Diagnosis Based on the Correlation between Effect Size and Sample Size

    Science.gov (United States)

    Kühberger, Anton; Fritz, Astrid; Scherndl, Thomas

    2014-01-01

    Background The p value obtained from a significance test provides no information about the magnitude or importance of the underlying phenomenon. Therefore, additional reporting of effect size is often recommended. Effect sizes are theoretically independent from sample size. Yet this may not hold true empirically: non-independence could indicate publication bias. Methods We investigate whether effect size is independent from sample size in psychological research. We randomly sampled 1,000 psychological articles from all areas of psychological research. We extracted p values, effect sizes, and sample sizes of all empirical papers, and calculated the correlation between effect size and sample size, and investigated the distribution of p values. Results We found a negative correlation of r = −.45 [95% CI: −.53; −.35] between effect size and sample size. In addition, we found an inordinately high number of p values just passing the boundary of significance. Additional data showed that neither implicit nor explicit power analysis could account for this pattern of findings. Conclusion The negative correlation between effect size and samples size, and the biased distribution of p values indicate pervasive publication bias in the entire field of psychology. PMID:25192357

  4. Exposure reduces negative bias in self-rated performance in public speaking fearful participants.

    Science.gov (United States)

    Cheng, Joyce; Niles, Andrea N; Craske, Michelle G

    2017-03-01

    Individuals with public speaking anxiety (PSA) under-rate their performance compared to objective observers. The present study examined whether exposure reduces the discrepancy between self and observer performance ratings and improved observer-rated performance in individuals with PSA. PSA participants gave a speech in front of a small audience and rated their performance using a questionnaire before and after completing repeated exposures to public speaking. Non-anxious control participants gave a speech and completed the questionnaire one time only. Objective observers watched videos of the speeches and rated performance using the same questionnaire. PSA participants underrated their performance to a greater degree than did controls prior to exposure, but also performed significantly more poorly than did controls when rated objectively. Bias significantly decreased and objective-rated performance significantly increased following completion of exposure in PSA participants, and on one performance measure, anxious participants no longer showed a greater discrepancy between self and observer performance ratings compared to controls. The study employed non-clinical student sample, but the results should be replicated in clinical anxiety samples. These findings indicate that exposure alone significantly reduces negative performance bias among PSA individuals, but additional exposure or additional interventions may be necessary to fully correct bias and performance deficits. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Orientation Bias of Optically Selected Galaxy Clusters and Its Impact on Stacked Weak Lensing Analyses

    CERN Document Server

    Dietrich, Jörg P; Song, Jeeseon; McKay, Christopher P Davis Timothy A; Baruah, Leon; Becker, Matthew; Benoist, Christophe; Busha, Michael; da Costa, Luiz A N; Hao, Jiangang; Maia, Marcio A G; Miller, Christopher J; Ogando, Ricardo; Romer, A Kathy; Rozo, Eduardo; Rykoff, Eli; Wechsler, Risa

    2014-01-01

    Weak-lensing measurements of the averaged shear profiles of galaxy clusters binned by some proxy for cluster mass are commonly converted to cluster mass estimates under the assumption that these cluster stacks have spherical symmetry. In this paper we test whether this assumption holds for optically selected clusters binned by estimated optical richness. Using mock catalogues created from N-body simulations populated realistically with galaxies, we ran a suite of optical cluster finders and estimated their optical richness. We binned galaxy clusters by true cluster mass and estimated optical richness and measure the ellipticity of these stacks. We find that the processes of optical cluster selection and richness estimation are biased, leading to stacked structures that are elongated along the line-of-sight. We show that weak-lensing alone cannot measure the size of this orientation bias. Weak lensing masses of stacked optically selected clusters are overestimated by up to 3-6 per cent when clusters can be uni...

  6. The VIMOS Public Extragalactic Redshift Survey (VIPERS). Hierarchical scaling and biasing

    Science.gov (United States)

    Cappi, A.; Marulli, F.; Bel, J.; Cucciati, O.; Branchini, E.; de la Torre, S.; Moscardini, L.; Bolzonella, M.; Guzzo, L.; Abbas, U.; Adami, C.; Arnouts, S.; Bottini, D.; Coupon, J.; Davidzon, I.; De Lucia, G.; Fritz, A.; Franzetti, P.; Fumana, M.; Garilli, B.; Granett, B. R.; Ilbert, O.; Iovino, A.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; McCracken, H. J.; Paioro, L.; Polletta, M.; Pollo, A.; Scodeggio, M.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.; Burden, A.; Di Porto, C.; Marchetti, A.; Marinoni, C.; Mellier, Y.; Nichol, R. C.; Peacock, J. A.; Percival, W. J.; Phleps, S.; Schimd, C.; Schlagenhaufer, H.; Wolk, M.; Zamorani, G.

    2015-07-01

    Aims: Building on the two-point correlation function analyses of the VIMOS Public Extragalactic Redshift Survey (VIPERS), we investigate the higher-order correlation properties of the same galaxy samples to test the hierarchical scaling hypothesis at z ~ 1 and the dependence on galaxy luminosity, stellar mass, and redshift. With this work we also aim to assess possible deviations from the linearity of galaxy bias independently from a previously performed analysis of our survey. Methods: We have measured the count probability distribution function in spherical cells of varying radii (3 ≤ R ≤ 10 h-1 Mpc), deriving σ8g (the galaxy rms at 8 h-1 Mpc), the volume-averaged two-, three-, and four-point correlation functions and the normalized skewness S3g and kurtosis S4g for different volume-limited subsamples, covering the following ranges: -19.5 ≤ MB(z = 1.1) - 5log (h) ≤ -21.0 in absolute magnitude, 9.0 ≤ log (M∗/M⊙h-2) ≤ 11.0 in stellar mass, and 0.5 ≤ zfollowing. 1) The hierarchical scaling between the volume-averaged two- and three-point and two- and four-point correlation functions holds throughout the whole range of scale and redshift we could test. 2) We do not find a significant dependence of S3g on luminosity (below z = 0.9 the value of S3g decreases with luminosity, but only at 1σ-level). 3) We do not detect a significant dependence of S3g and S4g on scale, except beyond z ~ 0.9, where S3g and S4g have higher values on large scales (R ≥ 10 h-1 Mpc): this increase is mainly due to one of the two CFHTLS Wide Fields observed by VIPERS and can be explained as a consequence of sample variance, consistently with our analysis of mock catalogs. 4) We do not detect a significant evolution of S3g and S4g with redshift (apart from the increase of their values with scale in the last redshift bin). 5) σ8g increases with luminosity, but does not show significant evolution with redshift. As a consequence, the linear bias factor b = σ8g/σ8m, where σ8

  7. En ny videnskabelig fejlkilde: SILLY-bias. Analyse af citationer af BMJ's juleartikler

    DEFF Research Database (Denmark)

    Felding, Ulrik A; Jørgensen, Karsten J; Hróbjartsson, Asbjørn

    2009-01-01

    We analysed the scientific impact of systematic reviews and randomised trials published in the BMJ Christmas issues 1997-2006. The articles were mostly interpreted correctly as humorous, but the humorous dimension was overlooked with surprising ease. The result from one ironic-absurd trial...

  8. Low sequencing efforts bias analyses of shared taxa in microbial communities.

    Science.gov (United States)

    Lemos, Leandro N; Fulthorpe, Roberta R; Roesch, Luiz F W

    2012-09-01

    The potential for comparing microbial community population structures has been greatly enhanced by developments in next generation sequencing methods that can generate hundreds of thousands to millions of reads in a single run. Conversely, many microbial community comparisons have been published with no more than 1,000 sequences per sample. These studies have presented data on levels of shared operational taxonomic units (OTUs) between communities. Due to lack of coverage, that approach might compromise the conclusions about microbial diversity and the degree of difference between environments. In this study, we present data from recent studies that highlight this problem. Also, we analyzed datasets of 16 rRNA sequences with small and high sequence coverage from different environments to demonstrate that the level of sequencing effort used for analyzing microbial communities biases the results. We randomly sampled pyrosequencing-generated 16S rRNA gene libraries with increasing sequence effort. Sequences were used to calculate Good's coverage, the percentage of shared OTUs, and phylogenetic distance measures. Our data showed that simple counts of presence/absence of taxonomic unities do not reflect the real similarity in membership and structure of the bacterial communities and that community comparisons based on phylogenetic tests provide a way to test statistically significant differences between two or more environments without need an exhaustive sampling effort.

  9. Randomly biased investments and the evolution of public goods on interdependent networks

    Science.gov (United States)

    Chen, Wei; Wu, Te; Li, Zhiwu; Wang, Long

    2017-08-01

    Deciding how to allocate resources between interdependent systems is significant to optimize efficiency. We study the effects of heterogeneous contribution, induced by such interdependency, on the evolution of cooperation, through implementing the public goods games on two-layer networks. The corresponding players on different layers try to share a fixed amount of resources as the initial investment properly. The symmetry breaking of investments between players located on different layers is able to either prevent investments from, or extract them out of the deadlock. Results show that a moderate investment heterogeneity is best favorable for the evolution of cooperation, and random allocation of investment bias suppresses the cooperators at a wide range of the investment bias and the enhancement effect. Further studies on time evolution with different initial strategy configurations show that the non-interdependent cooperators along the interface of interdependent cooperators also are an indispensable factor in facilitating cooperative behavior. Our main results are qualitatively unchanged even diversifying investment bias that is subject to uniform distribution. Our study may shed light on the understanding of the origin of cooperative behavior on interdependent networks.

  10. Content and Citation Analyses of "Public Relations Review."

    Science.gov (United States)

    Morton, Linda P.; Lin, Li-Yun

    1995-01-01

    Analyzes 161 cited and 177 uncited articles published in "Public Relations Review" (1975-93) to determine if 3 independent variables--research methods, type of statistics, and topics--influenced whether or not articles were cited in other research articles. Finds significant differences between quantitative and qualitative research methods but not…

  11. Microsatellite analyses provide evidence of male-biased dispersal in the radiated tortoise Astrochelys radiata (Chelonia: Testudinidae).

    Science.gov (United States)

    Paquette, Sébastien Rioux; Louis, Edward E; Lapointe, François-Joseph

    2010-01-01

    Dispersal is a major force in shaping the genetic structure and dynamics of species; thus, its understanding is critical in formulating appropriate conservation strategies. In many species, sexes do not face the same evolutionary pressures, and consequently dispersal is often asymmetrical between males and females. This is well documented in birds and mammals but has seldom been investigated in other taxa, including reptiles and, more specifically, nonmarine chelonians. In these species, nest-site fidelity observations are frequent but still remain to be associated with natal homing. Here, we tested for sex-biased dispersal in the radiated tortoise (Astrochelys radiata) from southern Madagascar. Using data from 13 microsatellite markers, we investigated patterns of relatedness between sexes in 2 populations. All Mantel tests indicated significant isolation by distance at the individual level in females but not in males. Furthermore, spatial autocorrelation analyses and 2 analytical approaches designed to assess general trends in sex-specific dispersal also supported male-biased dispersal. On the other hand, comparisons of overall genetic structure among sampling sites did not provide conclusive support for greater philopatry in females, but these tests may have low statistical power because of methodological and biological constraints. Radiated tortoises appear to be both polyandrous and polygynous, and evolutionary processes that may lead to a sex bias in dispersal are discussed with respect to tortoise breeding biology. Female natal homing is hypothesized as a key trait explaining greater female philopatry in A. radiata. These findings highlight the necessity of additional research on natal homing in tortoises, a behavioral trait with direct implications for conservation.

  12. How evidence-based medicine is failing due to biased trials and selective publication.

    Science.gov (United States)

    Every-Palmer, Susanna; Howick, Jeremy

    2014-12-01

    Evidence-based medicine (EBM) was announced in the early 1990s as a 'new paradigm' for improving patient care. Yet there is currently little evidence that EBM has achieved its aim. Since its introduction, health care costs have increased while there remains a lack of high-quality evidence suggesting EBM has resulted in substantial population-level health gains. In this paper we suggest that EBM's potential for improving patients' health care has been thwarted by bias in the choice of hypotheses tested, manipulation of study design and selective publication. Evidence for these flaws is clearest in industry-funded studies. We argue EBM's indiscriminate acceptance of industry-generated 'evidence' is akin to letting politicians count their own votes. Given that most intervention studies are industry funded, this is a serious problem for the overall evidence base. Clinical decisions based on such evidence are likely to be misinformed, with patients given less effective, harmful or more expensive treatments. More investment in independent research is urgently required. Independent bodies, informed democratically, need to set research priorities. We also propose that evidence rating schemes are formally modified so research with conflict of interest bias is explicitly downgraded in value. © 2014 John Wiley & Sons, Ltd.

  13. Publication bias in animal research presented at the 2008 Society of Critical Care Medicine Conference.

    Science.gov (United States)

    Conradi, Una; Joffe, Ari R

    2017-07-07

    To determine a direct measure of publication bias by determining subsequent full-paper publication (P) of studies reported in animal research abstracts presented at an international conference (A). We selected 100 random (using a random-number generator) A from the 2008 Society of Critical Care Medicine Conference. Using a data collection form and study manual, we recorded methodology and result variables from A. We searched PubMed and EMBASE to June 2015, and DOAJ and Google Scholar to May 2017 to screen for subsequent P. Methodology and result variables were recorded from P to determine changes in reporting from A. Predictors of P were examined using Fisher's Exact Test. 62% (95% CI 52-71%) of studies described in A were subsequently P after a median 19 [IQR 9-33.3] months from conference presentation. Reporting of studies in A was of low quality: randomized 27% (the method of randomization and allocation concealment not described), blinded 0%, sample-size calculation stated 0%, specifying the primary outcome 26%, numbers given with denominators 6%, and stating number of animals used 47%. Only being an orally presented (vs. poster presented) A (14/16 vs. 48/84, p = 0.025) predicted P. Reporting of studies in P was of poor quality: randomized 39% (the method of randomization and allocation concealment not described), likely blinded 6%, primary outcome specified 5%, sample size calculation stated 0%, numbers given with denominators 34%, and number of animals used stated 56%. Changes in reporting from A to P occurred: from non-randomized to randomized 19%, from non-blinded to blinded 6%, from negative to positive outcomes 8%, from having to not having a stated primary outcome 16%, and from non-statistically to statistically significant findings 37%. Post-hoc, using publication data, P was predicted by having positive outcomes (published 62/62, unpublished 33/38; p = 0.003), or statistically significant results (published 58/62, unpublished 20/38; p < 0

  14. Clustering of Local Group distances: publication bias or correlated measurements? I. The Large Magellanic Cloud

    CERN Document Server

    de Grijs, Richard; Bono, Giuseppe

    2014-01-01

    The distance to the Large Magellanic Cloud (LMC) represents a key local rung of the extragalactic distance ladder. Yet, the galaxy's distance modulus has long been an issue of contention, in particular in view of claims that most newly determined distance moduli cluster tightly - and with a small spread - around the "canonical" distance modulus, (m-M)_0 = 18.50 mag. We compiled 233 separate LMC distance determinations published between 1990 and 2013. Our analysis of the individual distance moduli, as well as of their two-year means and standard deviations resulting from this largest data set of LMC distance moduli available to date, focuses specifically on Cepheid and RR Lyrae variable-star tracer populations, as well as on distance estimates based on features in the observational Hertzsprung-Russell diagram. We conclude that strong publication bias is unlikely to have been the main driver of the majority of published LMC distance moduli. However, for a given distance tracer, the body of publications leading ...

  15. Estimates of the average strength of natural selection are not inflated by sampling error or publication bias.

    Science.gov (United States)

    Knapczyk, Frances N; Conner, Jeffrey K

    2007-10-01

    Kingsolver et al.'s review of phenotypic selection gradients from natural populations provided a glimpse of the form and strength of selection in nature and how selection on different organisms and traits varies. Because this review's underlying database could be a key tool for answering fundamental questions concerning natural selection, it has spawned discussion of potential biases inherent in the review process. Here, we explicitly test for two commonly discussed sources of bias: sampling error and publication bias. We model the relationship between variance among selection gradients and sample size that sampling error produces by subsampling large empirical data sets containing measurements of traits and fitness. We find that this relationship was not mimicked by the review data set and therefore conclude that sampling error does not bias estimations of the average strength of selection. Using graphical tests, we find evidence for bias against publishing weak estimates of selection only among very small studies (N<38). However, this evidence is counteracted by excess weak estimates in larger studies. Thus, estimates of average strength of selection from the review are less biased than is often assumed. Devising and conducting straightforward tests for different biases allows concern to be focused on the most troublesome factors.

  16. Clustering Analyses of 300,000 Photometrically Classified Quasars--I. Luminosity and Redshift Evolution in Quasar Bias

    CERN Document Server

    Myers, A D; Nichol, R C; Richards, G T; Schneider, D P; Bahcall, N A; Myers, Adam D.; Brunner, Robert J.; Nichol, Robert C.; Richards, Gordon T.; Schneider, Donald P.; Bahcall, Neta A.

    2006-01-01

    Using ~300,000 photometrically classified quasars, by far the largest quasar sample ever used for such analyses, we study the redshift and luminosity evolution of quasar clustering on scales of ~50 kpc/h to ~20 Mpc/h from redshifts of z~0.75 to z~2.28. We parameterize our clustering amplitudes using realistic dark matter models, and find that a LCDM power spectrum provides a superb fit to our data with a redshift-averaged quasar bias of b_Q = 2.41+/-0.08 ($P_{99.6% using our data set alone, increasing to >99.9999% if stellar contamination is not explicitly parameterized. We measure the quasar classification efficiency across our full sample as a = 95.6 +/- ^{4.4}_{1.9}%, a star-quasar separation comparable with the star-galaxy separation in many photometric studies of galaxy clustering. We derive the mean mass of the dark matter halos hosting quasars as MDMH=(5.2+/-0.6)x10^{12} M_solar/h. At z~1.9 we find a $1.5\\sigma$ deviation from luminosity-independent quasar clustering; this suggests that increasing our ...

  17. Clustering of local group distances: Publication bias or correlated measurements? II. M31 and beyond

    Energy Technology Data Exchange (ETDEWEB)

    De Grijs, Richard [Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871 (China); Bono, Giuseppe [Dipartimento di Fisica, Università di Roma Tor Vergata, via Della Ricerca Scientifica 1, I-00133, Roma (Italy)

    2014-07-01

    The accuracy of extragalactic distance measurements ultimately depends on robust, high-precision determinations of the distances to the galaxies in the local volume. Following our detailed study addressing possible publication bias in the published distance determinations to the Large Magellanic Cloud (LMC), here we extend our distance range of interest to include published distance moduli to M31 and M33, as well as to a number of their well-known dwarf galaxy companions. We aim at reaching consensus on the best, most homogeneous, and internally most consistent set of Local Group distance moduli to adopt for future, more general use based on the largest set of distance determinations to individual Local Group galaxies available to date. Based on a careful, statistically weighted combination of the main stellar population tracers (Cepheids, RR Lyrae variables, and the magnitude of the tip of the red-giant branch), we derive a recommended distance modulus to M31 of (m−M){sub 0}{sup M31}=24.46±0.10 mag—adopting as our calibration an LMC distance modulus of (m−M){sub 0}{sup LMC}=18.50 mag—and a fully internally consistent set of benchmark distances to key galaxies in the local volume, enabling us to establish a robust and unbiased, near-field extragalactic distance ladder.

  18. Quantitative evaluation of gender bias in astronomical publications from citation counts

    Science.gov (United States)

    Caplar, Neven; Tacchella, Sandro; Birrer, Simon

    2017-06-01

    Numerous studies across different research fields have shown that both male and female referees consistently give higher scores to work done by men than to identical work done by women 1,2,3 . In addition, women are under-represented in prestigious publications and authorship positions 4,5 and women receive ~10% fewer citations 6,7 . In astronomy, similar biases have been measured in conference participation 8,9 and success rates for telescope proposals 10,11 . Even though the number of doctorate degrees awarded to women is constantly increasing, women still tend to be under-represented in faculty positions 12 . Spurred by these findings, we measure the role of gender in the number of citations that papers receive in astronomy. To account for the fact that the properties of papers written by men and women differ intrinsically, we use a random forest algorithm to control for the non-gender-specific properties of these papers. Here we show that papers authored by women receive 10.4 ± 0.9% fewer citations than would be expected if the papers with the same non-gender-specific properties were written by men.

  19. Clustering of Local Group distances: publication bias or correlated measurements? IV. The Galactic Center

    CERN Document Server

    de Grijs, Richard

    2016-01-01

    Aiming at deriving a statistically well-justified Galactic Center distance, $R_0$, and reducing any occurrence of publication bias, we compiled the most comprehensive and most complete database of Galactic Center distances available to date, containing 273 new or revised $R_0$ estimates published since records began in October 1918 until June 2016. We separate our $R_0$ compilation into direct and indirect distance measurements. The latter include a large body of estimates that rely on centroid determinations for a range of tracer populations as well as measurements based on kinematic observations of objects at the solar circle, combined with a mass and/or rotational model of the Milky Way. Careful assessment of the Galactic Center distances resulting from orbital modeling and statistical parallax measurements in the Galactic nucleus yields our final Galactic Center distance recommendation of $R_0 = 8.3 \\pm 0.2 \\mbox{ (statistical)} \\pm 0.4 \\mbox{ (systematic)}$ kpc. The centroid-based distances are in good a...

  20. Clustering of Local Group distances: publication bias or correlated measurements? II. M31 and beyond

    CERN Document Server

    de Grijs, Richard

    2014-01-01

    The accuracy of extragalactic distance measurements ultimately depends on robust, high-precision determinations of the distances to the galaxies in the local volume. Following our detailed study addressing possible publication bias in the published distance determinations to the Large Magellanic Cloud (LMC), here we extend our distance range of interest to include published distance moduli to M31 and M33, as well as to a number of their well-known dwarf galaxy companions. We aim at reaching consensus on the best, most homogeneous, and internally most consistent set of Local Group distance moduli to adopt for future, more general use based on the largest set of distance determinations to individual Local Group galaxies available to date. Based on a careful, statistically weighted combination of the main stellar population tracers (Cepheids, RR Lyrae variables, and the magnitude of the tip of the red-giant branch), we derive a recommended distance modulus to M31 of $(m-M)_0^{\\rm M31} = 24.46 \\pm 0.10$ mag---ado...

  1. Bias in Cross-Sectional Analyses of Longitudinal Mediation: Partial and Complete Mediation under an Autoregressive Model

    Science.gov (United States)

    Maxwell, Scott E.; Cole, David A.; Mitchell, Melissa A.

    2011-01-01

    Maxwell and Cole (2007) showed that cross-sectional approaches to mediation typically generate substantially biased estimates of longitudinal parameters in the special case of complete mediation. However, their results did not apply to the more typical case of partial mediation. We extend their previous work by showing that substantial bias can…

  2. Subgroup analyses in randomised controlled trials: cohort study on trial protocols and journal publications.

    Science.gov (United States)

    Kasenda, Benjamin; Schandelmaier, Stefan; Sun, Xin; von Elm, Erik; You, John; Blümle, Anette; Tomonaga, Yuki; Saccilotto, Ramon; Amstutz, Alain; Bengough, Theresa; Meerpohl, Joerg J; Stegert, Mihaela; Olu, Kelechi K; Tikkinen, Kari A O; Neumann, Ignacio; Carrasco-Labra, Alonso; Faulhaber, Markus; Mulla, Sohail M; Mertz, Dominik; Akl, Elie A; Bassler, Dirk; Busse, Jason W; Ferreira-González, Ignacio; Lamontagne, Francois; Nordmann, Alain; Gloy, Viktoria; Raatz, Heike; Moja, Lorenzo; Rosenthal, Rachel; Ebrahim, Shanil; Vandvik, Per O; Johnston, Bradley C; Walter, Martin A; Burnand, Bernard; Schwenkglenks, Matthias; Hemkens, Lars G; Bucher, Heiner C; Guyatt, Gordon H; Briel, Matthias

    2014-07-16

    To investigate the planning of subgroup analyses in protocols of randomised controlled trials and the agreement with corresponding full journal publications. Cohort of protocols of randomised controlled trial and subsequent full journal publications. Six research ethics committees in Switzerland, Germany, and Canada. 894 protocols of randomised controlled trial involving patients approved by participating research ethics committees between 2000 and 2003 and 515 subsequent full journal publications. Of 894 protocols of randomised controlled trials, 252 (28.2%) included one or more planned subgroup analyses. Of those, 17 (6.7%) provided a clear hypothesis for at least one subgroup analysis, 10 (4.0%) anticipated the direction of a subgroup effect, and 87 (34.5%) planned a statistical test for interaction. Industry sponsored trials more often planned subgroup analyses compared with investigator sponsored trials (195/551 (35.4%) v 57/343 (16.6%), P<0.001). Of 515 identified journal publications, 246 (47.8%) reported at least one subgroup analysis. In 81 (32.9%) of the 246 publications reporting subgroup analyses, authors stated that subgroup analyses were prespecified, but this was not supported by 28 (34.6%) corresponding protocols. In 86 publications, authors claimed a subgroup effect, but only 36 (41.9%) corresponding protocols reported a planned subgroup analysis. Subgroup analyses are insufficiently described in the protocols of randomised controlled trials submitted to research ethics committees, and investigators rarely specify the anticipated direction of subgroup effects. More than one third of statements in publications of randomised controlled trials about subgroup prespecification had no documentation in the corresponding protocols. Definitive judgments regarding credibility of claimed subgroup effects are not possible without access to protocols and analysis plans of randomised controlled trials. © The DISCO study group 2014.

  3. Harmonic allocation of authorship credit: source-level correction of bibliometric bias assures accurate publication and citation analysis.

    Directory of Open Access Journals (Sweden)

    Nils T Hagen

    Full Text Available Authorship credit for multi-authored scientific publications is routinely allocated either by issuing full publication credit repeatedly to all coauthors, or by dividing one credit equally among all coauthors. The ensuing inflationary and equalizing biases distort derived bibliometric measures of merit by systematically benefiting secondary authors at the expense of primary authors. Here I show how harmonic counting, which allocates credit according to authorship rank and the number of coauthors, provides simultaneous source-level correction for both biases as well as accommodating further decoding of byline information. I also demonstrate large and erratic effects of counting bias on the original h-index, and show how the harmonic version of the h-index provides unbiased bibliometric ranking of scientific merit while retaining the original's essential simplicity, transparency and intended fairness. Harmonic decoding of byline information resolves the conundrum of authorship credit allocation by providing a simple recipe for source-level correction of inflationary and equalizing bias. Harmonic counting could also offer unrivalled accuracy in automated assessments of scientific productivity, impact and achievement.

  4. Estimating the price elasticity of beer: meta-analysis of data with heterogeneity, dependence, and publication bias.

    Science.gov (United States)

    Nelson, Jon P

    2014-01-01

    Precise estimates of price elasticities are important for alcohol tax policy. Using meta-analysis, this paper corrects average beer elasticities for heterogeneity, dependence, and publication selection bias. A sample of 191 estimates is obtained from 114 primary studies. Simple and weighted means are reported. Dependence is addressed by restricting number of estimates per study, author-restricted samples, and author-specific variables. Publication bias is addressed using funnel graph, trim-and-fill, and Egger's intercept model. Heterogeneity and selection bias are examined jointly in meta-regressions containing moderator variables for econometric methodology, primary data, and precision of estimates. Results for fixed- and random-effects regressions are reported. Country-specific effects and sample time periods are unimportant, but several methodology variables help explain the dispersion of estimates. In models that correct for selection bias and heterogeneity, the average beer price elasticity is about -0.20, which is less elastic by 50% compared to values commonly used in alcohol tax policy simulations.

  5. Homocysteine and coronary heart disease: meta-analysis of MTHFR case-control studies, avoiding publication bias.

    Directory of Open Access Journals (Sweden)

    Robert Clarke

    2012-02-01

    Full Text Available BACKGROUND: Moderately elevated blood levels of homocysteine are weakly correlated with coronary heart disease (CHD risk, but causality remains uncertain. When folate levels are low, the TT genotype of the common C677T polymorphism (rs1801133 of the methylene tetrahydrofolate reductase gene (MTHFR appreciably increases homocysteine levels, so "Mendelian randomization" studies using this variant as an instrumental variable could help test causality. METHODS AND FINDINGS: Nineteen unpublished datasets were obtained (total 48,175 CHD cases and 67,961 controls in which multiple genetic variants had been measured, including MTHFR C677T. These datasets did not include measurements of blood homocysteine, but homocysteine levels would be expected to be about 20% higher with TT than with CC genotype in the populations studied. In meta-analyses of these unpublished datasets, the case-control CHD odds ratio (OR and 95% CI comparing TT versus CC homozygotes was 1.02 (0.98-1.07; p = 0.28 overall, and 1.01 (0.95-1.07 in unsupplemented low-folate populations. By contrast, in a slightly updated meta-analysis of the 86 published studies (28,617 CHD cases and 41,857 controls, the OR was 1.15 (1.09-1.21, significantly discrepant (p = 0.001 with the OR in the unpublished datasets. Within the meta-analysis of published studies, the OR was 1.12 (1.04-1.21 in the 14 larger studies (those with variance of log OR<0.05; total 13,119 cases and 1.18 (1.09-1.28 in the 72 smaller ones (total 15,498 cases. CONCLUSIONS: The CI for the overall result from large unpublished datasets shows lifelong moderate homocysteine elevation has little or no effect on CHD. The discrepant overall result from previously published studies reflects publication bias or methodological problems.

  6. The Royal Birth of 2013: Analysing and Visualising Public Sentiment in the UK Using Twitter

    CERN Document Server

    Nguyen, Vu Dung; Barker, Adam

    2013-01-01

    Analysis of information retrieved from microblogging services such as Twitter can provide valuable insight into public sentiment in a geographic region. This insight can be enriched by visualising information in its geographic context. Two underlying approaches for sentiment analysis are dictionary-based and machine learning. The former is popular for public sentiment analysis, and the latter has found limited use for aggregating public sentiment from Twitter data. The research presented in this paper aims to extend the machine learning approach for aggregating public sentiment. To this end, a framework for analysing and visualising public sentiment from a Twitter corpus is developed. A dictionary-based approach and a machine learning approach are implemented within the framework and compared using one UK case study, namely the royal birth of 2013. The case study validates the feasibility of the framework for analysis and rapid visualisation. One observation is that there is good correlation between the resul...

  7. Systematic Reviews and Meta-Analyses of Traditional Chinese Medicine Must Search Chinese Databases to Reduce Language Bias

    Science.gov (United States)

    Wu, Xin-Yin; Tang, Jin-Ling; Mao, Chen; Yuan, Jin-Qiu; Qin, Ying; Chung, Vincent C. H.

    2013-01-01

    Systematic reviews (SRs) that fail to search non-English databases may miss relevant studies and cause selection bias. The bias may be particularly severe in SRs of traditional Chinese medicine (TCM) as most randomized controlled trials (RCT) in TCM are published and accessible only in Chinese. In this study we investigated how often Chinese databases were not searched in SRs of TCM, how many trials were missed, and whether a bias may occur if Chinese databases were not searched. We searched 5 databases in English and 3 in Chinese for RCTs of Chinese herbal medicine for coronary artery disease and found that 96.64% (115/119) eligible studies could be identified only from Chinese databases. In a random sample of 80 Cochrane reviews on TCM, we found that Chinese databases were only searched in 43 or 53.75%, in which almost all the included studies were identified from Chinese databases. We also compared SRs of the same topic and found that they may draw a different conclusion if Chinese databases were not searched. In conclusion, an overwhelmingly high percentage of eligible trials on TCM could only be identified in Chinese databases. Reviewers in TCM are suggested to search Chinese databases to reduce potential selection bias. PMID:24223063

  8. Public Sphere - Political Advertisement Relationship in Turkey: Analysing Political Advertisements of JDP in General Elections 2011

    Directory of Open Access Journals (Sweden)

    Erdal Dağtaş

    2015-09-01

    Full Text Available Public sphere is a social space, open to active individual access and free discussion, rescued from state intervention, where communicative action free from violence and individual benefits is undertaken; and rational-critical discourse is built. Political advertisement is the type advertising which aims at directing voters or the government to a particular action, having them adopt a certain view or approach. The concept of political advertising emerged with the practice of using commercial advertising techniques to promote a party, candidate or an idea. Justice and Development Party (JDP, has been ruling Turkey since 2002. The leader of the party is Prime Minister Recep Tayyip Erdoğan. It is a conservative party and has carried out some practices that could be regarded as negative. Anti-secular attitudes are also among these practices. Thus, analysing the political advertisements of JDP has proved to be interesting. Public sphere studies are mostly conducted through news stories and columns in media. In that sense, it is significant to analyse political advertisements in terms of public sphere. In this study, the political advertisements of the ruling Justice and Development Party (JDP in the process of Turkish General Parliamentary Election, 2011 have been analysed. The political advertisements in question have been analysed via Sabah newspaper. The reason for choosing Sabah is that it supports JDP as an example of partisan press. The samples have been taken from 2 weeks before the elections. Accordingly, as a full-page advertisement is published every day, 14 political advertisement analyses have been conducted in total. Political advertisements have been analysed using qualitative text analysis. As the study follows the path of public place-political advertising relationship, it finds meaning in itself.

  9. Corrigendum to: “Publication bias and time-trend bias in meta-analysis of bicycle helmet efficacy: a re-analysis of Attewell, Glase and McFadden, 2001” [Accid. Anal. Prev. 43 (2011) 1245–1251].

    Science.gov (United States)

    Elvik, Rune

    2013-11-01

    This paper is a corrigendum to the previously published paper: “Publication bias and time-trend bias in meta-analysis of bicycle helmet efficacy: A re-analysis of Attewell, Glase and McFadden, 2001” [Accid. Anal. Prev. (2011) 1245–1251]. This corrigendum was prepared to correct errors in data and analysis in the previously published paper. Like the previously published paper, this paper confirms that the meta-analysis of bicycle helmet efficacy reported by Attewell, Glase and McFadden (Accident Analysis and Prevention, 2001, 345–352) was influenced by publication bias and time-trend bias that was not controlled for. As a result, the analysis reported inflated estimates of the effects of bicycle helmets. This paper presents a re-analysis of the study. The re-analysis included: (1) Ensuring the inclusion of all published studies by means of continuity corrections of estimates of effect relying on zero counts; (2) detecting and adjusting for publication bias by means of the trim-and-fill method; (3) detecting and trying to account for a time-trend bias in estimates of the effects of bicycle helmets; (4) updating the study by including recently published studies evaluating the effects of bicycle helmets. The re-analysis shows smaller safety benefits associated with the use of bicycle helmets than the original study.

  10. Bibliometric analyses of publications from Centres of Excellence funded by the Danish National Research Foundation

    DEFF Research Database (Denmark)

    Schneider, Jesper Wiborg; Costas, Rodrigo; Henriksen, Dorte

    2013-01-01

    , the interaction with host institutions, and the governance and management of the DNRF. The evaluation concludes that the DNRF has had a very positive impact on the quality of research in Denmark and recommends that the foundation is re-funded. The evaluation is based on a bibliometric study, self......-assessment report by DNRF, numerous interviews and desk studies. Appendix 5: Bibliometric analyses of publications from Centres of Excellence funded by the Danish National Research Foundation...

  11. Publication bias and the limited strength model of self-control: has the evidence for ego depletion been overestimated?

    Science.gov (United States)

    Carter, Evan C; McCullough, Michael E

    2014-01-01

    Few models of self-control have generated as much scientific interest as has the limited strength model. One of the entailments of this model, the depletion effect, is the expectation that acts of self-control will be less effective when they follow prior acts of self-control. Results from a previous meta-analysis concluded that the depletion effect is robust and medium in magnitude (d = 0.62). However, when we applied methods for estimating and correcting for small-study effects (such as publication bias) to the data from this previous meta-analysis effort, we found very strong signals of publication bias, along with an indication that the depletion effect is actually no different from zero. We conclude that until greater certainty about the size of the depletion effect can be established, circumspection about the existence of this phenomenon is warranted, and that rather than elaborating on the model, research efforts should focus on establishing whether the basic effect exists. We argue that the evidence for the depletion effect is a useful case study for illustrating the dangers of small-study effects as well as some of the possible tools for mitigating their influence in psychological science.

  12. Identifying public health policymakers' sources of information: comparing survey and network analyses.

    Science.gov (United States)

    Oliver, Kathryn A; de Vocht, Frank; Money, Annemarie; Everett, Martin

    2017-05-01

    Research suggests that policymakers often use personal contacts to find information and advice. However, the main sources of information for public health policymakers are not known. This study aims to describe policymakers' sources of information. A questionnaire survey of public health policymakers across Greater Manchester (GM) was carried out (response rate 48%). All policy actors above Director level involved in public health policy (finding, analyzing or producing information, producing or implementing policy) in GM were included in the sampling frame. Respondents were provided with a list of sources of information and asked which they used (categorical data) and to name specific individuals who acted as sources of information (network data). Data were analyzed using frequencies and network analysis. The most frequently chosen sources of information from the categorical data were NICE, government websites and Directors of Public Health. However, the network data showed that the main sources of information in the network were actually mid-level managers in the NHS, who had no direct expertise in public health. Academics and researchers did not feature in the network. Both survey and network analyses provide useful insights into how policymakers access information. Network analysis offers practical and theoretical contributions to the evidence-based policy debate. Identifying individuals who act as key users and producers of evidence allows academics to target actors likely to use and disseminate their work.

  13. Motivating Citizens to Participate in Public Policymaking: Identification, Trust and Cost-Benefit Analyses

    Directory of Open Access Journals (Sweden)

    Matteo Antonini

    2015-10-01

    Full Text Available Under what conditions do citizens of nations and states comply with governmental requests to participate in public policymaking? Drawing on the dual pathway model of collective action (Stürmer & Simon, 2004 but with a focus on compliance with the status quo, rather than participation in collective protest, two studies examined citizens’ motivation to participate in public policymaking. Study 1 (N = 169 was an MTurk hosted survey that recruited participants from California, while Study 2 (N = 198 was a field experiment that recruited participants in Sardinia, Italy. Study 1 measured cost-benefit analyses, societal identification, and willingness to participate in public policymaking. Study 2 repeated the same procedures, with the exception that we manipulated costs of participation, and also measured participants’ trust in government. Study 1 confirmed our initial hypotheses – fewer costs predicted more willingness to participate, as did stronger state identification. However, Study 2 found an interactive effect of costs, identification, and trust on willingness to participate in public policymaking. Results confirm our hypotheses by showing that both costs and identification independently influence willingness to participate in public policymaking. Results also add to the literature by showing that these additive pathways can be influenced by trust in the source of governance.

  14. Identifying Useful Terms to Retrieve Survival Data Meta-Analyses Publications for Bibliographic Databases Search Strategies

    Directory of Open Access Journals (Sweden)

    Daniel Corneliu LEUCUŢA

    2009-12-01

    Full Text Available Introduction: Quality research and quality evidence based medicine practice has an important pillar in a solid bibliographic documentation. Quality bibliographic documentation makes use of search strategies to retrieve articles from search engines of bibliographic databases. The AIM of this study was the identification of useful search terms to be used in search strategies that try to find meta-analyses of survival data. Materials and methods: A qualitative study based on text analysis was undertaken to identify useful terms for search strategies in abstracts of scientific papers. Survival analysis meta-analyses publication type studies, published between 1996 and 2005, were searched in Medline bibliographic database through Pubmed web interface. Each abstract was analysed and each important terms were noted down if they were considered to be useful in the creation of search strategies for analysis of survival data, or meta-analyses. Results: Pubmed search yielded 773 results. From these search results 401 (52% fulfilled inclusion criteria. The terms that were identified as useful in search strategies for meta-analyses of survival data are presented in the paper.

  15. Quantifying the bias in the estimated treatment effect in randomized trials having interim analyses and a rule for early stopping for futility.

    Science.gov (United States)

    Walter, S D; Han, H; Briel, M; Guyatt, G H

    2017-04-30

    In this paper, we consider the potential bias in the estimated treatment effect obtained from clinical trials, the protocols of which include the possibility of interim analyses and an early termination of the study for reasons of futility. In particular, by considering the conditional power at an interim analysis, we derive analytic expressions for various parameters of interest: (i) the underestimation or overestimation of the treatment effect in studies that stop for futility; (ii) the impact of the interim analyses on the estimation of treatment effect in studies that are completed, i.e. that do not stop for futility; (iii) the overall estimation bias in the estimated treatment effect in a single study with such a stopping rule; and (iv) the probability of stopping at an interim analysis. We evaluate these general expressions numerically for typical trial scenarios. Results show that the parameters of interest depend on a number of factors, including the true underlying treatment effect, the difference that the trial is designed to detect, the study power, the number of planned interim analyses and what assumption is made about future data to be observed after an interim analysis. Because the probability of stopping early is small for many practical situations, the overall bias is often small, but a more serious issue is the potential for substantial underestimation of the treatment effect in studies that actually stop for futility. We also consider these ideas using data from an illustrative trial that did stop for futility at an interim analysis. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Robustness assessments are needed to reduce bias in meta-analyses that include zero-event randomized trials.

    NARCIS (Netherlands)

    Keus, F.; Wetterslev, J.; Gluud, C.; Gooszen, H.G.; Laarhoven, C.J.H.M. van

    2009-01-01

    OBJECTIVES: Meta-analysis of randomized trials with binary data can use a variety of statistical methods. Zero-event trials may create analytic problems. We explored how different methods may impact inferences from meta-analyses containing zero-event trials. METHODS: Five levels of statistical metho

  17. Robustness Assessments Are Needed to Reduce Bias in Meta-Analyses That Include Zero-Event Randomized Trials

    NARCIS (Netherlands)

    Keus, F.; Wetterslev, J.; Gluud, C.; Gooszen, H. G.; van Laarhoven, C. J. H. M.

    2009-01-01

    OBJECTIVES: Meta-analysis of randomized trials with binary data can use a variety of statistical methods. Zero-event trials may create analytic problems. We explored how different methods may impact inferences from meta-analyses containing zero-event trials. METHODS: Five levels of statistical metho

  18. Analyses on Energy Saving Potential Based on Large-scale Public Buildings Energy Consumption

    Directory of Open Access Journals (Sweden)

    Xuping Chen

    2012-08-01

    Full Text Available To analyze large-scale public buildings’ energy-saving potential is one of the methods to realize scientific energy control management and service. This method aims at a typical public building’s powerconsumed system. Through analyzing and comparing the consumption data, it succeeds in analyzing the use efficiency of building power, consumption level and economic effects of the energy utilization. More over, this method has a quantity analysis on the power-consumed unit’s building usage, so that it is able to find the unit’s energy-saving potential. Its bases of all analyses are building energy balance and analyzing theory of energy cost, analyzing theory of engineering economy and environment and rational distribution theory of energy utilization system.

  19. Socio community practices’ analyses at a public superior education institution: Social commitment and transformational potential

    Directory of Open Access Journals (Sweden)

    Romina TIRITILLI

    2016-11-01

    Full Text Available The present research pretends to know about socio community practices’ transformational aspects done by advanced students from a superior education public institution. It’s an exploratory descriptive and qualitative research in which there were used different instruments: tutorials non participant observation during the practices; final students’ colloquies non participant observation; teachers’ critical incidents interviews and students’ final written reports. The sample was intentional composed by students (N=65 and teachers (N=6 from a superior education public institution socio community practices. Basics descriptive statistics were calculated and critical incidents’ and final written reports’ content analyses were done. Results show that socio community practices following the social learning technique promote students transformation in epistemology, social, pedagogic and ethic dimensions. These transformations promote pro social and citizenship behaviors, an ethic position related to professional activity, a critical reflection and community commitment.

  20. Publication Bias in Reports of Animal Stroke Studies Leads to Major Overstatement of Efficacy

    NARCIS (Netherlands)

    Sena, Emily S.; van der Worp, H. Bart; Bath, Philip M. W.; Howells, David W.; Macleod, Malcolm R.

    2010-01-01

    The consolidation of scientific knowledge proceeds through the interpretation and then distillation of data presented in research reports, first in review articles and then in textbooks and undergraduate courses, until truths become accepted as such both amongst "experts'' and in the public understa

  1. The comparison of classification analyses on the public opinion focus of biofuels based on twitter

    Science.gov (United States)

    Wu, Shianghau; Guo, Jiannjong

    2016-02-01

    The study combined with the text mining and classification methodology to investigate the biofuels related tweets on the social network so as to understand the general public opinion focus. The contribution of the study enclosed the subsequent two points. First, the study utilized the text mining method to explore the content of biofuels connected tweets on the famed social network "twitter" and found the main keywords consistent with their frequencies. Second, the study applied the Back Propagation Neural Network (BPN), random forests model and two sorts of hybrid algorithmclassification analyses to compare the classification results.

  2. Role of Editorial and Peer Review Processes in Publication Bias: Analysis of Drug Trials Submitted to Eight Medical Journals

    Science.gov (United States)

    van Lent, Marlies; Overbeke, John; Out, Henk Jan

    2014-01-01

    Background Publication bias is generally ascribed to authors and sponsors failing to submit studies with negative results, but may also occur after submission. We evaluated whether submitted manuscripts on randomized controlled trials (RCTs) with drugs are more likely to be accepted if they report positive results. Methods Manuscripts submitted from January 2010 through April 2012 to one general medical journal (BMJ) and seven specialty journals (Annals of the Rheumatic Diseases, British Journal of Ophthalmology, Gut, Heart, Thorax, Diabetologia, and Journal of Hepatology) were included, if at least one study arm assessed the efficacy or safety of a drug and a statistical test was used to evaluate treatment effects. Publication status was retrospectively retrieved from submission systems or provided by journals. Sponsorship and trial results were extracted from manuscripts and classified according to predefined criteria. Main outcome measure was acceptance for publication. Results Of 15,972 manuscripts submitted, 472 (3.0%) were drug RCTs, of which 98 (20.8%) were published. Among submitted drug RCTs, 287 (60.8%) had positive and 185 (39.2%) negative results. Of these, 60 (20.9%) and 38 (20.5%), respectively, were published. Manuscripts on non-industry trials (n = 213) reported positive results in 138 (64.8%) manuscripts, compared to 71 (47.7%) on industry-supported trials (n = 149), and 78 (70.9%) on industry-sponsored trials (n = 110). Twenty-seven (12.7%) non-industry trials were published, compared to 27 (18.1%) industry-supported and 44 (40.0%) industry-sponsored trials. After adjustment for other trial characteristics, manuscripts reporting positive results were not more likely to be published (OR, 1.00; 95% CI, 0.61 to 1.66). Submission to specialty journals, sample size, multicentre status, journal impact factor, and corresponding authors from Europe or US were significantly associated with publication. Conclusions For the selected journals

  3. Role of editorial and peer review processes in publication bias: analysis of drug trials submitted to eight medical journals.

    Directory of Open Access Journals (Sweden)

    Marlies van Lent

    Full Text Available Publication bias is generally ascribed to authors and sponsors failing to submit studies with negative results, but may also occur after submission. We evaluated whether submitted manuscripts on randomized controlled trials (RCTs with drugs are more likely to be accepted if they report positive results.Manuscripts submitted from January 2010 through April 2012 to one general medical journal (BMJ and seven specialty journals (Annals of the Rheumatic Diseases, British Journal of Ophthalmology, Gut, Heart, Thorax, Diabetologia, and Journal of Hepatology were included, if at least one study arm assessed the efficacy or safety of a drug and a statistical test was used to evaluate treatment effects. Publication status was retrospectively retrieved from submission systems or provided by journals. Sponsorship and trial results were extracted from manuscripts and classified according to predefined criteria. Main outcome measure was acceptance for publication.Of 15,972 manuscripts submitted, 472 (3.0% were drug RCTs, of which 98 (20.8% were published. Among submitted drug RCTs, 287 (60.8% had positive and 185 (39.2% negative results. Of these, 60 (20.9% and 38 (20.5%, respectively, were published. Manuscripts on non-industry trials (n = 213 reported positive results in 138 (64.8% manuscripts, compared to 71 (47.7% on industry-supported trials (n = 149, and 78 (70.9% on industry-sponsored trials (n = 110. Twenty-seven (12.7% non-industry trials were published, compared to 27 (18.1% industry-supported and 44 (40.0% industry-sponsored trials. After adjustment for other trial characteristics, manuscripts reporting positive results were not more likely to be published (OR, 1.00; 95% CI, 0.61 to 1.66. Submission to specialty journals, sample size, multicentre status, journal impact factor, and corresponding authors from Europe or US were significantly associated with publication.For the selected journals, there was no tendency to preferably publish

  4. Sample-Size Planning for More Accurate Statistical Power: A Method Adjusting Sample Effect Sizes for Publication Bias and Uncertainty.

    Science.gov (United States)

    Anderson, Samantha F; Kelley, Ken; Maxwell, Scott E

    2017-09-01

    The sample size necessary to obtain a desired level of statistical power depends in part on the population value of the effect size, which is, by definition, unknown. A common approach to sample-size planning uses the sample effect size from a prior study as an estimate of the population value of the effect to be detected in the future study. Although this strategy is intuitively appealing, effect-size estimates, taken at face value, are typically not accurate estimates of the population effect size because of publication bias and uncertainty. We show that the use of this approach often results in underpowered studies, sometimes to an alarming degree. We present an alternative approach that adjusts sample effect sizes for bias and uncertainty, and we demonstrate its effectiveness for several experimental designs. Furthermore, we discuss an open-source R package, BUCSS, and user-friendly Web applications that we have made available to researchers so that they can easily implement our suggested methods.

  5. The M235T polymorphism in the AGT gene and CHD risk: evidence of a Hardy-Weinberg equilibrium violation and publication bias in a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Mohammad Hadi Zafarmand

    Full Text Available BACKGROUND: The M235T polymorphism in the AGT gene has been related to an increased risk of hypertension. This finding may also suggest an increased risk of coronary heart disease (CHD. METHODOLOGY/PRINCIPAL FINDINGS: A case-cohort study was conducted in 1,732 unrelated middle-age women (210 CHD cases and 1,522 controls from a prospective cohort of 15,236 initially healthy Dutch women. We applied a Cox proportional hazards model to study the association of the polymorphism with acute myocardial infarction (AMI (n = 71 and CHD. In the case-cohort study, no increased risk for CHD was found under the additive genetic model (hazard ratio [HR] = 1.20; 95% confidence interval [CI], 0.86 to 1.68; P = 0.28. This result was not changed by adjustment (HR = 1.17; 95% CI, 0.83 to 1.64; P = 0.38 nor by using dominant, recessive and pairwise genetic models. Analyses for AMI risk under the additive genetic model also did not show any statistically significant association (crude HR = 1.14; 95% CI, 0.93 to 1.39; P = 0.20. To evaluate the association, a comprehensive systematic review and meta-analysis were undertaken of all studies published up to February 2007 (searched through PubMed/MEDLINE, Web of Science and EMBASE. The meta-analysis (38 studies with 13284 cases and 18722 controls showed a per-allele odds ratio (OR of 1.08 (95% CI, 1.01 to 1.15; P = 0.02. Moderate to large levels of heterogeneity were identified between studies. Hardy-Weinberg equilibrium (HWE violation and the mean age of cases were statistically significant sources of the observed variation. In a stratum of non-HWE violation studies, there was no effect. An asymmetric funnel plot, the Egger's test (P = 0.066, and the Begg-Mazumdar test (P = 0.074 were all suggestive of the presence of publication bias. CONCLUSIONS/SIGNIFICANCE: The pooled OR of the present meta-analysis, including our own data, presented evidence that there is an increase in the risk of CHD conferred by the M235T variant

  6. Predictors of Biased Self-perception in Individuals with High Social Anxiety: The Effect of Self-consciousness in the Private and Public Self Domains.

    Science.gov (United States)

    Nordahl, Henrik; Plummer, Alice; Wells, Adrian

    2017-01-01

    "Biased self-perception," the tendency to perceive one's social performance as more negative than observers do, is characteristic of socially anxious individuals. Self-attention processes are hypothesised to underlie biased self-perception, however, different models emphasise different aspects of self-attention, with attention to the public aspects of the self being prominent. The current study aimed to investigate the relative contribution of two types of dispositional self-attention; public- and private self-consciousness to biased self-perception in a high (n = 48) versus a low (n = 48) social anxiety group undergoing an interaction task. The main finding was that private self-consciousness explained substantial and unique variance in biased negative self-perception in individuals with high social anxiety, while public self-consciousness did not. This relationship was independent of increments in state anxiety. Private self-consciousness appeared to have a specific association with bias related to overestimation of negative social performance rather than underestimation of positive social performance. The implication of this finding is that current treatment models of Social anxiety disorder might include broader aspects of self-focused attention, especially in the context of formulating self-evaluation biases.

  7. Predictors of Biased Self-perception in Individuals with High Social Anxiety: The Effect of Self-consciousness in the Private and Public Self Domains

    Directory of Open Access Journals (Sweden)

    Henrik Nordahl

    2017-07-01

    Full Text Available “Biased self-perception,” the tendency to perceive one’s social performance as more negative than observers do, is characteristic of socially anxious individuals. Self-attention processes are hypothesised to underlie biased self-perception, however, different models emphasise different aspects of self-attention, with attention to the public aspects of the self being prominent. The current study aimed to investigate the relative contribution of two types of dispositional self-attention; public- and private self-consciousness to biased self-perception in a high (n = 48 versus a low (n = 48 social anxiety group undergoing an interaction task. The main finding was that private self-consciousness explained substantial and unique variance in biased negative self-perception in individuals with high social anxiety, while public self-consciousness did not. This relationship was independent of increments in state anxiety. Private self-consciousness appeared to have a specific association with bias related to overestimation of negative social performance rather than underestimation of positive social performance. The implication of this finding is that current treatment models of Social anxiety disorder might include broader aspects of self-focused attention, especially in the context of formulating self-evaluation biases.

  8. Quantitative Evaluation of Gender Bias in Astronomical Publications from Citation Counts

    CERN Document Server

    Caplar, Neven; Birrer, Simon

    2016-01-01

    We analyze the role of first (leading) author gender on the number of citations that a paper receives, on the publishing frequency and on the self-citing tendency. We consider a complete sample of over 200,000 publications from 1950 to 2015 from five major astronomy journals. We determine the gender of the first author for over 70% of all publications. The fraction of papers which have a female first author has increased from less than 5% in the 1960s to about 25% today. We find that the increase of the fraction of papers authored by females is slowest in the most prestigious journals such as Science and Nature. Furthermore, female authors write 19$\\pm$7% fewer papers in seven years following their first paper than their male colleagues. At all times papers with male first authors receive more citations than papers with female first authors. This difference has been decreasing with time and amounts to $\\sim$6% measured over the last 30 years. To account for the fact that the properties of female and male firs...

  9. No publication bias in industry funded clinical trials of degenerative diseases of the spine.

    Science.gov (United States)

    Son, Colin; Tavakoli, Samon; Bartanusz, Viktor

    2016-03-01

    Industry sponsorship of clinical research of degenerative diseases of the spine has been associated with excessive positive published results as compared to research carried out without industry funding. We sought the rates of publication of clinical trials of degenerative diseases of the spine based on funding source as a possible explanation for this phenomenon. We reviewed all clinical trials registered at clinicaltrials.gov relating to degenerative diseases of the spine as categorized under six medical subject heading terms (spinal stenosis, spondylolisthesis, spondylolysis, spondylosis, failed back surgery syndrome, intervertebral disc degeneration) and with statuses of completed or terminated. These collected studies were categorized as having, or not having, industry funding. Published results for these studies were then sought within the clinicaltrials.gov database itself, PubMed and Google Scholar. One hundred sixty-one clinical trials met these criteria. One hundred nineteen of these trials had industry funding and 42 did not. Of those with industry funding, 45 (37.8%) had identifiable results. Of those without industry funding, 17 (40.5%) had identifiable results. There was no difference in the rates of publication of results from clinical trials of degenerative diseases of the spine no matter the funding source.

  10. Comparative analyses of downstream signal transduction targets modulated after activation of the AT1 receptor by two β-arrestin-biased agonists.

    Science.gov (United States)

    Santos, Geisa A; Duarte, Diego A; Parreiras-E-Silva, Lucas T; Teixeira, Felipe R; Silva-Rocha, Rafael; Oliveira, Eduardo B; Bouvier, Michel; Costa-Neto, Claudio M

    2015-01-01

    G protein-coupled receptors (GPCRs) are involved in essentially all physiological processes in mammals. The classical GPCR signal transduction mechanism occurs by coupling to G protein, but it has recently been demonstrated that interaction with β-arrestins leads to activation of pathways that are independent of the G protein pathway. Also, it has been reported that some ligands can preferentially activate one of these signaling pathways; being therefore called biased agonists for G protein or β-arrestin pathways. The angiotensin II (AngII) AT1 receptor is a prototype GPCR in the study of biased agonism due to the existence of well-known β-arrestin-biased agonists, such as [Sar(1), Ile(4), Ile(8)]-AngII (SII), and [Sar(1), D-Ala(8)]-AngII (TRV027). The aim of this study was to comparatively analyze the two above mentioned β-arrestin-biased agonists on downstream phosphorylation events and gene expression profiles. Our data reveal that activation of AT1 receptor by each ligand led to a diversity of activation profiles that is far broader than that expected from a simple dichotomy between "G protein-dependent" and "β-arrestin-dependent" signaling. We observed clusters of activation profiles common to AngII, SII, and TRV027, as well as downstream effector activation that are unique to AngII, SII, or TRV027. Analyses of β-arrestin conformational changes after AT1 receptor stimulation with SII or TRV027 suggests that the observed differences could account, at least partially, for the diversity of modulated targets observed. Our data reveal that, although the categorization "G protein-dependent" vs. "β-arrestin-dependent" signaling can be of pharmacological relevance, broader analyses of signaling pathways and downstream targets are necessary to generate an accurate activation profile for a given ligand. This may bring relevant information for drug development, as it may allow more refined comparison of drugs with similar mechanism of action and effects, but with

  11. Comparative analyses of downstream signal transduction targets modulated after activation of the AT1 receptor by two β-arrestin biased agonists

    Directory of Open Access Journals (Sweden)

    Geisa A Santos

    2015-07-01

    Full Text Available G protein-coupled receptors (GPCRs are involved in essentially all physiological processes in mammals. The classical GPCR signal transduction mechanism occurs by coupling to G protein, but it has recently been demonstrated that interaction with β-arrestins leads to activation of pathways that are independent of the G protein pathway. Also, it has been reported that some ligands can preferentially activate one of these signaling pathways; being therefore called biased agonists for G protein or β-arrestin pathways. The angiotensin II (AngII AT1 receptor is a prototype GPCR in the study of biased agonism due to the existence of well-known β-arrestin biased agonists, such as [Sar1,Ile4,Ile8]-AngII (SII, and [Sar1,D-Ala8]-AngII (TRV027. The aim of this study was to comparatively analyze the two above mentioned β-arrestin biased agonists on downstream phosphorylation events and gene expression profiles. Our data reveal that activation of AT1 receptor by each ligand led to a diversity of activation profiles that is far broader than that expected from a simple dichotomy between G protein-dependent and β-arrestin-dependent signaling. We observed clusters of activation profiles common to AngII, SII and TRV027, as well as downstream effector activation that are unique to AngII, SII, or TRV027. Analyses of β-arrestin conformational changes after AT1 receptor stimulation with SII or TRV027 suggests that the observed differences could account, at least partially, for the diversity of modulated targets observed. Our data reveal that, although the categorization G protein-dependent vs. β-arrestin-dependent signaling can be of pharmacological relevance, broader analyses of signaling pathways and downstream targets are necessary to generate an accurate activation profile for a given ligand. This may bring relevant information for drug development, as it may allow more refined comparison of drugs with similar mechanism of action and effects, but with

  12. Mechanisms and direction of allocation bias in randomised clinical trials

    DEFF Research Database (Denmark)

    Paludan-Müller, Asger Sand; Laursen, David R. T.; Hróbjartsson, Asbjørn

    2016-01-01

    clinical trials. METHODS: Two systematic reviews and a theoretical analysis. We conducted one systematic review of empirical studies of motives/methods for deciphering patient allocation sequences; and another review of methods publications commenting on allocation bias. We theoretically analysed...

  13. Physics teaching in a public school: an ethnographic case study with an epistemological bias

    Directory of Open Access Journals (Sweden)

    Neusa T. Massoni

    2012-04-01

    Full Text Available This paper is a classroom ethnography. Ethnography in a research strategy that attempts to comprehensively describe a culture, in this case the culture of a physics classroom in the 12th grade of a public high school in Porto Alegre, Brazil. This study is part of a larger scope study designed to investigate the contributions of contemporary views of the nature of science to the improvement of physics teaching. It is in sense that this paper assumes an epistemological perspective. The physics teacher that was observed had conceptions partially aligned to those epistemological views, however, although our initial intention was to search for relationships between her conceptions an her teaching practices we ended up with a detailed interpretative description of the classroom reality that revealed relevant aspects to the comprehension of such a culture and to the teaching and learning process in physics. This interpretative description is what we present here.

  14. Does Publication Bias Inflate the Apparent Efficacy of Psychological Treatment for Major Depressive Disorder? A Systematic Review and Meta-Analysis of US National Institutes of Health-Funded Trials.

    Directory of Open Access Journals (Sweden)

    Ellen Driessen

    Full Text Available The efficacy of antidepressant medication has been shown empirically to be overestimated due to publication bias, but this has only been inferred statistically with regard to psychological treatment for depression. We assessed directly the extent of study publication bias in trials examining the efficacy of psychological treatment for depression.We identified US National Institutes of Health grants awarded to fund randomized clinical trials comparing psychological treatment to control conditions or other treatments in patients diagnosed with major depressive disorder for the period 1972-2008, and we determined whether those grants led to publications. For studies that were not published, data were requested from investigators and included in the meta-analyses. Thirteen (23.6% of the 55 funded grants that began trials did not result in publications, and two others never started. Among comparisons to control conditions, adding unpublished studies (Hedges' g = 0.20; CI95% -0.11~0.51; k = 6 to published studies (g = 0.52; 0.37~0.68; k = 20 reduced the psychotherapy effect size point estimate (g = 0.39; 0.08~0.70 by 25%. Moreover, these findings may overestimate the "true" effect of psychological treatment for depression as outcome reporting bias could not be examined quantitatively.The efficacy of psychological interventions for depression has been overestimated in the published literature, just as it has been for pharmacotherapy. Both are efficacious but not to the extent that the published literature would suggest. Funding agencies and journals should archive both original protocols and raw data from treatment trials to allow the detection and correction of outcome reporting bias. Clinicians, guidelines developers, and decision makers should be aware that the published literature overestimates the effects of the predominant treatments for depression.

  15. Does Publication Bias Inflate the Apparent Efficacy of Psychological Treatment for Major Depressive Disorder? A Systematic Review and Meta-Analysis of US National Institutes of Health-Funded Trials

    Science.gov (United States)

    Driessen, Ellen; Hollon, Steven D.; Bockting, Claudi L. H.; Cuijpers, Pim; Turner, Erick H.

    2015-01-01

    Background The efficacy of antidepressant medication has been shown empirically to be overestimated due to publication bias, but this has only been inferred statistically with regard to psychological treatment for depression. We assessed directly the extent of study publication bias in trials examining the efficacy of psychological treatment for depression. Methods and Findings We identified US National Institutes of Health grants awarded to fund randomized clinical trials comparing psychological treatment to control conditions or other treatments in patients diagnosed with major depressive disorder for the period 1972–2008, and we determined whether those grants led to publications. For studies that were not published, data were requested from investigators and included in the meta-analyses. Thirteen (23.6%) of the 55 funded grants that began trials did not result in publications, and two others never started. Among comparisons to control conditions, adding unpublished studies (Hedges’ g = 0.20; CI95% -0.11~0.51; k = 6) to published studies (g = 0.52; 0.37~0.68; k = 20) reduced the psychotherapy effect size point estimate (g = 0.39; 0.08~0.70) by 25%. Moreover, these findings may overestimate the "true" effect of psychological treatment for depression as outcome reporting bias could not be examined quantitatively. Conclusion The efficacy of psychological interventions for depression has been overestimated in the published literature, just as it has been for pharmacotherapy. Both are efficacious but not to the extent that the published literature would suggest. Funding agencies and journals should archive both original protocols and raw data from treatment trials to allow the detection and correction of outcome reporting bias. Clinicians, guidelines developers, and decision makers should be aware that the published literature overestimates the effects of the predominant treatments for depression. PMID:26422604

  16. Estimating and modelling bias of the hierarchical partitioning public-domain software: implications in environmental management and conservation.

    Directory of Open Access Journals (Sweden)

    Pedro P Olea

    Full Text Available BACKGROUND: Hierarchical partitioning (HP is an analytical method of multiple regression that identifies the most likely causal factors while alleviating multicollinearity problems. Its use is increasing in ecology and conservation by its usefulness for complementing multiple regression analysis. A public-domain software "hier.part package" has been developed for running HP in R software. Its authors highlight a "minor rounding error" for hierarchies constructed from >9 variables, however potential bias by using this module has not yet been examined. Knowing this bias is pivotal because, for example, the ranking obtained in HP is being used as a criterion for establishing priorities of conservation. METHODOLOGY/PRINCIPAL FINDINGS: Using numerical simulations and two real examples, we assessed the robustness of this HP module in relation to the order the variables have in the analysis. Results indicated a considerable effect of the variable order on the amount of independent variance explained by predictors for models with >9 explanatory variables. For these models the nominal ranking of importance of the predictors changed with variable order, i.e. predictors declared important by its contribution in explaining the response variable frequently changed to be either most or less important with other variable orders. The probability of changing position of a variable was best explained by the difference in independent explanatory power between that variable and the previous one in the nominal ranking of importance. The lesser is this difference, the more likely is the change of position. CONCLUSIONS/SIGNIFICANCE: HP should be applied with caution when more than 9 explanatory variables are used to know ranking of covariate importance. The explained variance is not a useful parameter to use in models with more than 9 independent variables. The inconsistency in the results obtained by HP should be considered in future studies as well as in those

  17. There may not be a cultural life script for public events, but there is a youth bias: Response to Janssen (2014)

    DEFF Research Database (Denmark)

    Koppel, Jonathan Mark; Berntsen, Dorthe

    2015-01-01

    Janssen asserts that, in a recent paper, we introduced the concept of a cultural life script for public events, in the form of the youth bias. Moreover, he contends that we claimed to have found evidence for such a life script. Correspondingly, he frames his own failure to find evidence for a lif...

  18. Quantifying male-biased dispersal among social groups in the collared peccary (Pecari tajacu) using analyses based on mtDNA variation.

    Science.gov (United States)

    Cooper, J D; Vitalis, R; Waser, P M; Gopurenko, D; Hellgren, E C; Gabor, T M; DeWoody, J A

    2010-01-01

    Recent advances in the statistical analysis of microsatellite data permit calculation of sex-specific dispersal rates through sex- and age-specific comparisons of genetic variation. This approach, developed for the analysis of data derived from co-dominant autosomal markers, should be applicable to a sex-specific marker such as mitochondrial DNA. To test this premise, we amplified a 449 bp control region DNA sequence from the mitochondrial genome of the collared peccary (Pecari tajacu), and estimated intra-class correlations among herds sampled from three Texas populations. Analyses on data partitioned by breeding group showed a clear signal of male-biased dispersal; sex-specific fixation indices associated with genetic variation among social groups within populations yielded values for females (F(GP)=0.91), which were significantly larger than values for males (F(GP)=0.24; P=0.0015). The same general pattern emerged when the analyses were conducted on age classes (albeit nonsignificantly), as well as categories of individuals that were predicted a posteriori to be dispersers (adult males) and philopatric (adult females and all immatures). By extending a previously published methodology based on biparentally inherited markers to matrilineally inherited haploid data, we calculated sex-specific rates of contemporary dispersal among social groups within populations (m(male symbol)=0.37). These results support the idea that mitochondrial DNA haplotype frequency data can be used to estimate sex-specific instantaneous dispersal rates in a social species.

  19. Evaluating Public Health Interventions: 3. The Two-Stage Design for Confounding Bias Reduction-Having Your Cake and Eating It Two.

    Science.gov (United States)

    Spiegelman, Donna; Rivera-Rodriguez, Claudia L; Haneuse, Sebastien

    2016-07-01

    In public health evaluations, confounding bias in the estimate of the intervention effect will typically threaten the validity of the findings. It is a common misperception that the only way to avoid this bias is to measure detailed, high-quality data on potential confounders for every intervention participant, but this strategy for adjusting for confounding bias is often infeasible. Rather than ignoring confounding altogether, the two-phase design and analysis-in which detailed high-quality confounding data are obtained among a small subsample-can be considered. We describe the two-stage design and analysis approach, and illustrate its use in the evaluation of an intervention conducted in Dar es Salaam, Tanzania, of an enhanced community health worker program to improve antenatal care uptake.

  20. Disorganized Systematic Reviews and Meta-analyses: Time to Systematize the Conduct and Publication of These Study Overviews?

    Science.gov (United States)

    Riaz, Irbaz Bin; Khan, Muhammad Shahzeb; Riaz, Haris; Goldberg, Robert J

    2016-03-01

    The number of meta-analyses published annually has increased more than 20-fold between 1994 (n = 386) and 2014 (n = 8203). In examining how much of this increase in meta-analysis publication has genuinely represented novel contributions to clinical medicine and public health, it became clear that there was an abundance of redundant and disorganized meta-analyses, creating confusion and generating considerable debate. Ironically, meta-analyses, which should prevent redundant research, have become a victim of it. Recently, 17 meta-analyses were published based on the results of only 3 randomized controlled trials that studied the role of transcatheter closure of patent foramen ovale for prevention of cryptogenic stroke. In our search of the published literature, we identified at least 10 topics that were the subject of 10 meta-analyses. In the context of overlapping meta-analyses, one questions what needs to be done to put this "runaway train" back on track. In this review we examine the practice of redundant meta-analyses and the reasons for its disturbing "popularity." The registration of systematic reviews should be mandatory in prospective registries, such as PROSPERO, and the PRISMA checklist should be updated to incorporate new evidence and mandate the reference of previously published reviews and rationale for any new study.

  1. Analysing researchers’ outreach efforts and the association with publication metrics: A case study of Kudos

    Science.gov (United States)

    Aung, Htet Htet; Aw, Ashley Sara; Rapple, Charlie; Theng, Yin-Leng

    2017-01-01

    With the growth of scholarly collaboration networks and social communication platforms, members of the scholarly community are experimenting with their approach to disseminating research outputs, in an effort to increase their audience and outreach. However, from a researcher’s point of view, it is difficult to determine whether efforts to make work more visible are worthwhile (in terms of the association with publication metrics) and within that, difficult to assess which platform or network is most effective for sharing work and connecting to a wider audience. We undertook a case study of Kudos (https://www.growkudos.com), a web-based service that claims to help researchers increase the outreach of their publications, to examine the most effective tools for sharing publications online, and to investigate which actions are associated with improved metrics. We extracted a dataset from Kudos of 830,565 unique publications claimed by authors, for which 20,775 had actions taken to explain or share via Kudos, and for 4,867 of these full text download data from publishers was available. Findings show that researchers are most likely to share their work on Facebook, but links shared on Twitter are more likely to be clicked on. A Mann-Whitney U test revealed that a treatment group (publications having actions in Kudos) had a significantly higher median average of 149 full text downloads (23.1% more) per publication as compared to a control group (having no actions in Kudos) with a median average of 121 full text downloads per publication. These findings suggest that performing actions on publications, such as sharing, explaining, or enriching, could help to increase the number of full text downloads of a publication. PMID:28817627

  2. Les Partenariats Public-Privé: Fondement théorique et analyse économique

    Directory of Open Access Journals (Sweden)

    N. MAATALA

    2017-05-01

    Full Text Available The Public-Private Partnership (PPP is globally recognized as a common style of management, especially in the sectors of transportation, public services and community facilities. The interests of this partnership approach reside in the off-budget financing for the public partner, in the private partners’ high rate of return, in the reduced completion deadlines of the projects, and finally in the availability and quality of the public service provided. The economic theory sees in PPPs many advantages and disadvantages related not only to the partnership, but also to the nature of the public-private relationship that is considered as a particular relationship. In this article, we analyze in the first part the main theoretical foundations in which the Public Private Partnership (PPP is inserted, then, we present the assumptions and the principles of each theory. In the second part, we present an economic analysis of this partnership approach while going through its advantages, disadvantages, and potential paths to address its limitations.

  3. Lessons for public health campaigns from analysing commercial food marketing success factors

    DEFF Research Database (Denmark)

    Aschemann-Witzel, Jessica; JA Perez-Cueto, Federico; Niedzwiedzka, Barbara

    2012-01-01

    Background: Commercial food marketing has considerably shaped consumer food choice behaviour. Meanwhile, public health campaigns for healthier eating have had limited impact to date. Social marketing suggests that successful commercial food marketing campaigns can provide useful lessons for public...... sector activities. The aim of the present study was to empirically identify food marketing success factors that, using the social marketing approach, could help improve public health campaigns to promote healthy eating. Methods: In this case-study analysis, 27 recent and successful commercial food...... and beverage marketing cases were purposively sampled from different European countries. The cases involved different consumer target groups, product categories, company sizes and marketing techniques. The analysis focused on cases of relatively healthy food types, and nutrition and health-related aspects...

  4. Analysing improvements to on-street public transport systems: a mesoscopic model approach

    DEFF Research Database (Denmark)

    Ingvardson, Jesper Bláfoss; Kornerup Jensen, Jonas; Nielsen, Otto Anker

    2017-01-01

    Light rail transit and bus rapid transit have shown to be efficient and cost-effective in improving public transport systems in cities around the world. As these systems comprise various elements, which can be tailored to any given setting, e.g. pre-board fare-collection, holding strategies...... and other advanced public transport systems (APTS), the attractiveness of such systems depends heavily on their implementation. In the early planning stage it is advantageous to deploy simple and transparent models to evaluate possible ways of implementation. For this purpose, the present study develops...... a mesoscopic model which makes it possible to evaluate public transport operations in details, including dwell times, intelligent traffic signal timings and holding strategies while modelling impacts from other traffic using statistical distributional data thereby ensuring simplicity in use and fast...

  5. Analyses of the Impact of School Uniforms on Violence in North Carolina Public High Schools

    Science.gov (United States)

    Johnson, Wesley Scott

    2010-01-01

    This study incorporated a multiple-methods design utilizing both quantitative and qualitative data. The quantitative portion investigated several annual reports distributed by the North Carolina Department of Public Instruction (NCDPI) to explore the impact of school uniform policies on incidents of crime and violence and occurrences of…

  6. Bias in research.

    Science.gov (United States)

    Simundić, Ana-Maria

    2013-01-01

    By writing scientific articles we communicate science among colleagues and peers. By doing this, it is our responsibility to adhere to some basic principles like transparency and accuracy. Authors, journal editors and reviewers need to be concerned about the quality of the work submitted for publication and ensure that only studies which have been designed, conducted and reported in a transparent way, honestly and without any deviation from the truth get to be published. Any such trend or deviation from the truth in data collection, analysis, interpretation and publication is called bias. Bias in research can occur either intentionally or unintentionally. Bias causes false conclusions and is potentially misleading. Therefore, it is immoral and unethical to conduct biased research. Every scientist should thus be aware of all potential sources of bias and undertake all possible actions to reduce or minimize the deviation from the truth. This article describes some basic issues related to bias in research.

  7. Global city aspirations, graduated citizenship and public housing: analysing the consumer citizenships of neoliberalism

    Directory of Open Access Journals (Sweden)

    Dallas Rogers

    2014-01-01

    Full Text Available Global city discourses rearticulate the relationships between the state, urban space and the global economy. At the local level, global city reconfigurations stamp the mark of a global economic order onto local citizenship practices. Public housing is a legacy of specific national (welfare states where citizenship rights arose from territorially bound constitutional discourses, and is incompatible in its current form with the consumer-based rights and responsibilities of a global economic order. At the same time, property markets in high-value areas of cities like Sydney, Australia, see not only increasing presence of international investment but fundamental changes in planning and governance processes in order to facilitate it. Global market-oriented discourses of urban governance promote consumer “performances of citizenship” and a graduated approach to the distribution of rights, including the right to housing. In this article we explore what is new about neoliberal approaches to public and social housing policy, and how public tenants respond to and negotiate it. In Australia tenants’ right to participate in local-level democracy, and in housing management, must be reconsidered in light of the broader discourses of consumer citizenship that are now enforced on tenants as a set of “responsibilities” to the market and state.

  8. The Regressive Research of Bias Least Square Method of Public Financial Capability of China%我国财政能力的偏最小二乘回归研究

    Institute of Scientific and Technical Information of China (English)

    周子康; 崔斌

    2003-01-01

    Based on the adjustment of public financial revenue and expenditure of China according to the international comparable scope, the authors project and research the condition of public financial revenue and expenditure in China by using bias least square method. After the analysis, the authors think that the real public financial capability of China is not as weak as people estimate in advance.

  9. Lessons for public health campaigns from analysing commercial food marketing success factors: a case study

    Directory of Open Access Journals (Sweden)

    Aschemann-Witzel Jessica

    2012-02-01

    Full Text Available Abstract Background Commercial food marketing has considerably shaped consumer food choice behaviour. Meanwhile, public health campaigns for healthier eating have had limited impact to date. Social marketing suggests that successful commercial food marketing campaigns can provide useful lessons for public sector activities. The aim of the present study was to empirically identify food marketing success factors that, using the social marketing approach, could help improve public health campaigns to promote healthy eating. Methods In this case-study analysis, 27 recent and successful commercial food and beverage marketing cases were purposively sampled from different European countries. The cases involved different consumer target groups, product categories, company sizes and marketing techniques. The analysis focused on cases of relatively healthy food types, and nutrition and health-related aspects in the communication related to the food. Visual as well as written material was gathered, complemented by semi-structured interviews with 12 food market trend experts and 19 representatives of food companies and advertising agencies. Success factors were identified by a group of experts who reached consensus through discussion structured by a card sorting method. Results Six clusters of success factors emerged from the analysis and were labelled as "data and knowledge", "emotions", "endorsement", "media", "community" and "why and how". Each cluster subsumes two or three success factors and is illustrated by examples. In total, 16 factors were identified. It is argued that the factors "nutritional evidence", "trend awareness", "vertical endorsement", "simple naturalness" and "common values" are of particular importance in the communication of health with regard to food. Conclusions The present study identified critical factors for the success of commercial food marketing campaigns related to the issue of nutrition and health, which are possibly

  10. Lessons for public health campaigns from analysing commercial food marketing success factors: a case study.

    Science.gov (United States)

    Aschemann-Witzel, Jessica; Perez-Cueto, Federico J A; Niedzwiedzka, Barbara; Verbeke, Wim; Bech-Larsen, Tino

    2012-02-21

    Commercial food marketing has considerably shaped consumer food choice behaviour. Meanwhile, public health campaigns for healthier eating have had limited impact to date. Social marketing suggests that successful commercial food marketing campaigns can provide useful lessons for public sector activities. The aim of the present study was to empirically identify food marketing success factors that, using the social marketing approach, could help improve public health campaigns to promote healthy eating. In this case-study analysis, 27 recent and successful commercial food and beverage marketing cases were purposively sampled from different European countries. The cases involved different consumer target groups, product categories, company sizes and marketing techniques. The analysis focused on cases of relatively healthy food types, and nutrition and health-related aspects in the communication related to the food. Visual as well as written material was gathered, complemented by semi-structured interviews with 12 food market trend experts and 19 representatives of food companies and advertising agencies. Success factors were identified by a group of experts who reached consensus through discussion structured by a card sorting method. Six clusters of success factors emerged from the analysis and were labelled as "data and knowledge", "emotions", "endorsement", "media", "community" and "why and how". Each cluster subsumes two or three success factors and is illustrated by examples. In total, 16 factors were identified. It is argued that the factors "nutritional evidence", "trend awareness", "vertical endorsement", "simple naturalness" and "common values" are of particular importance in the communication of health with regard to food. The present study identified critical factors for the success of commercial food marketing campaigns related to the issue of nutrition and health, which are possibly transferable to the public health sector. Whether or not a particular

  11. Lessons for public health campaigns from analysing commercial food marketing success factors: a case study

    Science.gov (United States)

    2012-01-01

    Background Commercial food marketing has considerably shaped consumer food choice behaviour. Meanwhile, public health campaigns for healthier eating have had limited impact to date. Social marketing suggests that successful commercial food marketing campaigns can provide useful lessons for public sector activities. The aim of the present study was to empirically identify food marketing success factors that, using the social marketing approach, could help improve public health campaigns to promote healthy eating. Methods In this case-study analysis, 27 recent and successful commercial food and beverage marketing cases were purposively sampled from different European countries. The cases involved different consumer target groups, product categories, company sizes and marketing techniques. The analysis focused on cases of relatively healthy food types, and nutrition and health-related aspects in the communication related to the food. Visual as well as written material was gathered, complemented by semi-structured interviews with 12 food market trend experts and 19 representatives of food companies and advertising agencies. Success factors were identified by a group of experts who reached consensus through discussion structured by a card sorting method. Results Six clusters of success factors emerged from the analysis and were labelled as "data and knowledge", "emotions", "endorsement", "media", "community" and "why and how". Each cluster subsumes two or three success factors and is illustrated by examples. In total, 16 factors were identified. It is argued that the factors "nutritional evidence", "trend awareness", "vertical endorsement", "simple naturalness" and "common values" are of particular importance in the communication of health with regard to food. Conclusions The present study identified critical factors for the success of commercial food marketing campaigns related to the issue of nutrition and health, which are possibly transferable to the public health

  12. Spatial data infrastructures at work analysing the spatial enablement of public sector processes

    CERN Document Server

    Dessers, Ezra

    2013-01-01

    In 'Spatial Data Infrastructures at Work', Ezra Dessers introduces spatial enablement as a key concept to describe the realisation of SDI objectives in the context of individual public sector processes. Drawing on four years of research, Dessers argues that it has become essential, even unavoidable, to manage and (re)design inter-organisational process chains in order to further advance the role of SDIs as an enabling platform for a spatially enabled society. Detailed case studies illustrate that the process he describes is the setting in which one can see the SDI at work.

  13. Association of study quality with completeness of reporting: have completeness of reporting and quality of systematic reviews and meta-analyses in major radiology journals changed since publication of the PRISMA statement?

    Science.gov (United States)

    Tunis, Adam S; McInnes, Matthew D F; Hanna, Ramez; Esmail, Kaisra

    2013-11-01

    To evaluate whether completeness of reporting of systematic reviews and meta-analyses in major radiology journals has changed since publication of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement; a secondary objective is to evaluate whether completeness of reporting (ie, PRISMA) is associated with study quality (ie, Assessing the Methodological Quality of Systematic Reviews [AMSTAR]). Systematic reviews and meta-analyses published in major radiology journals between January 2007 and December 2011 were identified by searching MEDLINE with the modified Montori method. Studies were reviewed independently by two investigators and assessed for adherence to the AMSTAR and PRISMA checklists. The average results were analyzed to assess for change in mean score before and after PRISMA publication and to assess results over time; a Pearson correlation coefficient was calculated to assess for any association between PRISMA and AMSTAR results. Included were 130 studies from 11 journals. Average PRISMA and AMSTAR results were 21.8 of 27 and 7.2 of 11, respectively. The average result was higher after publication of PRISMA, and PRISMA-reported items were 22.6 of 27 after publication of PRISMA versus 20.9 of 27 before publication of PRISMA; AMSTAR results were 7.7 of 11 after publication of PRISMA versus 6.7 of 11 before publication of PRISMA. There was a strong positive correlation (r = 0.86) between the PRISMA and AMSTAR results. There was high variability between journals. Radiology had the highest PRISMA reported items (24.7 of 27), and American Journal of Neuroradiology had the lowest (19.6 of 27). Two major areas for improvement include study protocol registration and assessment of risk of bias across studies (ie, publication bias). In major radiology journal studies, there was modest improvement in completeness of reporting of systematic reviews and meta-analyses, assessed by PRISMA, which was strongly associated with higher study

  14. What Risk Assessments of Genetically Modified Organisms Can Learn from Institutional Analyses of Public Health Risks

    Directory of Open Access Journals (Sweden)

    S. Ravi Rajan

    2012-01-01

    Full Text Available The risks of genetically modified organisms (GMOs are evaluated traditionally by combining hazard identification and exposure estimates to provide decision support for regulatory agencies. We question the utility of the classical risk paradigm and discuss its evolution in GMO risk assessment. First, we consider the problem of uncertainty, by comparing risk assessment for environmental toxins in the public health domain with genetically modified organisms in the environment; we use the specific comparison of an insecticide to a transgenic, insecticidal food crop. Next, we examine normal accident theory (NAT as a heuristic to consider runaway effects of GMOs, such as negative community level consequences of gene flow from transgenic, insecticidal crops. These examples illustrate how risk assessments are made more complex and contentious by both their inherent uncertainty and the inevitability of failure beyond expectation in complex systems. We emphasize the value of conducting decision-support research, embracing uncertainty, increasing transparency, and building interdisciplinary institutions that can address the complex interactions between ecosystems and society. In particular, we argue against black boxing risk analysis, and for a program to educate policy makers about uncertainty and complexity, so that eventually, decision making is not the burden that falls upon scientists but is assumed by the public at large.

  15. What risk assessments of genetically modified organisms can learn from institutional analyses of public health risks.

    Science.gov (United States)

    Rajan, S Ravi; Letourneau, Deborah K

    2012-01-01

    The risks of genetically modified organisms (GMOs) are evaluated traditionally by combining hazard identification and exposure estimates to provide decision support for regulatory agencies. We question the utility of the classical risk paradigm and discuss its evolution in GMO risk assessment. First, we consider the problem of uncertainty, by comparing risk assessment for environmental toxins in the public health domain with genetically modified organisms in the environment; we use the specific comparison of an insecticide to a transgenic, insecticidal food crop. Next, we examine normal accident theory (NAT) as a heuristic to consider runaway effects of GMOs, such as negative community level consequences of gene flow from transgenic, insecticidal crops. These examples illustrate how risk assessments are made more complex and contentious by both their inherent uncertainty and the inevitability of failure beyond expectation in complex systems. We emphasize the value of conducting decision-support research, embracing uncertainty, increasing transparency, and building interdisciplinary institutions that can address the complex interactions between ecosystems and society. In particular, we argue against black boxing risk analysis, and for a program to educate policy makers about uncertainty and complexity, so that eventually, decision making is not the burden that falls upon scientists but is assumed by the public at large.

  16. ArrayWiki: an enabling technology for sharing public microarray data repositories and meta-analyses.

    Science.gov (United States)

    Stokes, Todd H; Torrance, J T; Li, Henry; Wang, May D

    2008-05-28

    A survey of microarray databases reveals that most of the repository contents and data models are heterogeneous (i.e., data obtained from different chip manufacturers), and that the repositories provide only basic biological keywords linking to PubMed. As a result, it is difficult to find datasets using research context or analysis parameters information beyond a few keywords. For example, to reduce the "curse-of-dimension" problem in microarray analysis, the number of samples is often increased by merging array data from different datasets. Knowing chip data parameters such as pre-processing steps (e.g., normalization, artefact removal, etc), and knowing any previous biological validation of the dataset is essential due to the heterogeneity of the data. However, most of the microarray repositories do not have meta-data information in the first place, and do not have a a mechanism to add or insert this information. Thus, there is a critical need to create "intelligent" microarray repositories that (1) enable update of meta-data with the raw array data, and (2) provide standardized archiving protocols to minimize bias from the raw data sources. To address the problems discussed, we have developed a community maintained system called ArrayWiki that unites disparate meta-data of microarray meta-experiments from multiple primary sources with four key features. First, ArrayWiki provides a user-friendly knowledge management interface in addition to a programmable interface using standards developed by Wikipedia. Second, ArrayWiki includes automated quality control processes (caCORRECT) and novel visualization methods (BioPNG, Gel Plots), which provide extra information about data quality unavailable in other microarray repositories. Third, it provides a user-curation capability through the familiar Wiki interface. Fourth, ArrayWiki provides users with simple text-based searches across all experiment meta-data, and exposes data to search engine crawlers (Semantic Agents

  17. Misunderstanding publication bias: editors are not blameless after all [v1; ref status: indexed, http://f1000r.es/YvAwwD

    Directory of Open Access Journals (Sweden)

    Stephen Senn

    2012-12-01

    Full Text Available In analysing whether there is an editorial bias in favour of positive studies, researchers have made implicit assumptions that are implausible. In particular, to justify the conclusion that there is no bias because observed editorial acceptance rates do not favour positive studies, the assumption that the decision to submit an article is based solely on quality would be required. If, on the other hand, submission were based on perceived probability of acceptance, negative and positive studies would not differ in terms of acceptance rates, but in terms of quality. It is shown, using a simple graphical model, how similar underlying situations as regards the relationship between quality and probability of acceptance on the one hand and study outcome (positive or negative and probability of acceptance on the other could produce dramatically different results depending on the behaviour of authors. Furthermore, there is, in fact, some evidence that submitted negative studies are, on average, of higher quality than positive ones. This calls into question the standard interpretation of the studies examining editorial bias. It would appear that despite similar probabilities of acceptance for negative and positive studies, editors could be discriminating against negative studies.

  18. Media Bias

    OpenAIRE

    Sendhil Mullainathan; Andrei Shleifer

    2002-01-01

    There are two different types of media bias. One bias, which we refer to as ideology, reflects a news outlet's desire to affect reader opinions in a particular direction. The second bias, which we refer to as spin, reflects the outlet's attempt to simply create a memorable story. We examine competition among media outlets in the presence of these biases. Whereas competition can eliminate the effect of ideological bias, it actually exaggerates the incentive to spin stories.

  19. Bias and Uncertainty of Critical Experiment Models with CSAS25 from SCALE4.4a for Criticality Safety Analyses On the HP J-5600 (CMODB) Workstation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.H.; Keener, H.J.; DeClue, J.F.; Krass, A.W.; Cain, V.R.

    2001-02-01

    This report documents establishment of bias, bias trends and uncertainty for validation of the CSAS25 control module from the SCALE 4.4a computer code system for use in evaluating criticality safety of uranium systems. The 27-group ENDF/B-IV, 44-group ENDF/B-V, and 238-group ENDF/B-V cross-section libraries were used. The criticality validation calculations were performed using over 500 benchmark cases from Volumes II and IV of the ''International Handbook of Evaluated Criticality Safety Benchmark Experiments,'' published by the Nuclear Energy Agency Organization for Economic Cooperation and Development (NEA/OECD). Based on statistical analysis of the calculation results, the bias, bias trends and uncertainty of the benchmark calculations have been established for these benchmark experiments. Numerical methods for applying margins are briefly described, but the determination of appropriate correlating parameter and values for additional margin, applicable to a particular analysis, must be determined as part of process analysis. As such, this document does not specify upper subcritical limits as has been done in the past. A follow-on report will be written to assess the methods for determination of an upper safety limit in more detail, provide comparisons, and recommend a preferred method. Analysts using these results are responsible for exercising sound engineering judgment using strong technical arguments to develop a margin in k{sub eff} or other correlating parameter that is sufficiently large to ensure that conditions (calculated by this method to be subcritical by this margin) will actually be subcritical. Documentation of determination and justification of the appropriate margin in the analyst's evaluation, in conjunction with this report, will constitute the complete Validation Report in accordance with ANSI/ANS-8.1-1998, Section 4.3.6(4).

  20. Scientometric trend analyses of publications on the history of psychology: Is psychology becoming an unhistorical science?

    Science.gov (United States)

    Krampen, Günter

    Examines scientometrically the trends in and the recent situation of research on and the teaching of the history of psychology in the German-speaking countries and compares the findings with the situation in other countries (mainly the United States) by means of the psychology databases PSYNDEX and PsycINFO. Declines of publications on the history of psychology are described scientometrically for both research communities since the 1990s. Some impulses are suggested for the future of research on and the teaching of the history of psychology. These include (1) the necessity and significance of an intensified use of quantitative, unobtrusive scientometric methods in historiography in times of digital "big data", (2) the necessity and possibilities to integrate qualitative and quantitative methodologies in historical research and teaching, (3) the reasonableness of interdisciplinary cooperation of specialist historians, scientometricians, and psychologists, (4) the meaningfulness and necessity to explore, investigate, and teach more intensively the past and the problem history of psychology as well as the understanding of the subject matter of psychology in its historical development in cultural contexts. The outlook on the future of such a more up-to-date research on and teaching of the history of psychology is-with some caution-positive.

  1. Injures onomasti et public : éléments pour une analyse interactionnelle.

    Directory of Open Access Journals (Sweden)

    Rossella Saetta Cottone

    2007-07-01

    Full Text Available Cet article se propose de mettre en lumière les dynamiques interactionnelles mises en œuvre par la pratique comique de l’onomasti kômôidein, à travers le recours à certaines instruments théoriques fournis par la socio-linguistique (analyse interactionnelle et conversationnelle. En soulignant l’analogie existante entre les injures que les acteurs adressent contre des citoyens réels appelés par leur nom et la calomnie, la diabolè,  il propose de nuancer l’opposition, qui domine la critique aristophanienne, entre les interprétations « ritualistes » et les interprétations « politiques » de ce phénomène dramatique.This article aims to shed light on the interactional dynamics created by the comic practice of onomasti kômôidein, making use of some theoretical tools provided by sociolinguistics (interactional and conversational analysis in particular. By illuminating the analogy that exists between the insults aimed by actors at actual citizens called by their real names on the one hand, and slander (diabolè on the other hand, this paper seeks to give nuance to an opposition which dominates Aristophanic criticism: between "ritualist" and "political" interpretations of the dramatic phenomenon in question.

  2. Precision Metagenomics: Rapid Metagenomic Analyses for Infectious Disease Diagnostics and Public Health Surveillance

    Science.gov (United States)

    Afshinnekoo, Ebrahim; Chou, Chou; Alexander, Noah; Ahsanuddin, Sofia; Schuetz, Audrey N.; Mason, Christopher E.

    2017-01-01

    Next-generation sequencing (NGS) technologies have ushered in the era of precision medicine, transforming the way we treat cancer patients and diagnose disease. Concomitantly, the advent of these technologies has created a surge of microbiome and metagenomic studies over the last decade, many of which are focused on investigating the host-gene-microbial interactions responsible for the development and spread of infectious diseases, as well as delineating their key role in maintaining health. As we continue to discover more information about the etiology of infectious diseases, the translational potential of metagenomic NGS methods for treatment and rapid diagnosis is becoming abundantly clear. Here, we present a robust protocol for the implementation and application of “precision metagenomics” across various sequencing platforms for clinical samples. Such a pipeline integrates DNA/RNA extraction, library preparation, sequencing, and bioinformatics analyses for taxonomic classification, antimicrobial resistance (AMR) marker screening, and functional analysis (biochemical and metabolic pathway abundance). Moreover, the pipeline has 3 tracks: STAT for results within 24 h; Comprehensive that affords a more in-depth analysis and takes between 5 and 7 d, but offers antimicrobial resistance information; and Targeted, which also requires 5–7 d, but with more sensitive analysis for specific pathogens. Finally, we discuss the challenges that need to be addressed before full integration in the clinical setting.

  3. Bias in Peripheral Depression Biomarkers

    DEFF Research Database (Denmark)

    Carvalho, André F; Köhler, Cristiano A; Brunoni, André R

    2016-01-01

    BACKGROUND: To aid in the differentiation of individuals with major depressive disorder (MDD) from healthy controls, numerous peripheral biomarkers have been proposed. To date, no comprehensive evaluation of the existence of bias favoring the publication of significant results or inflating effect...... sizes has been conducted. METHODS: Here, we performed a comprehensive review of meta-analyses of peripheral nongenetic biomarkers that could discriminate individuals with MDD from nondepressed controls. PubMed/MEDLINE, EMBASE, and PsycINFO databases were searched through April 10, 2015. RESULTS: From 15...

  4. Geographical Information System (GIS) as a tool for monitoring and analysing pesticide pollution and its impact on public health.

    Science.gov (United States)

    Kamińska, Iwona A; Ołdak, Anna; Turski, Waldemar A

    2004-01-01

    Geographical Information System (GIS) combines information from cartography sources (i.e. maps), earthbound surveys, remote sensing (i.e. aerial and satellite imagery) and creates overlapping layers that can be accessed, transformed, and manipulated interactively in one spatial structure. Thanks to the great flexibility of GIS, its possible applications are countless. For example, dynamic databases created by GIS can manage information from various sources and make spatial correlations with epidemiological data about temporal distribution of environmentally-related diseases. GIS has also been increasingly used to monitor, analyse and model pesticide migration in the environment. GIS analysis has proved to be a valuable tool in environmental and public health studies yielding important results that may ultimately help prevent excessive or uncontrolled exposure to xenobiotics, including pesticides. Despite its obvious advantages GIS technology is still not commonly used for such studies, particularly in the developing countries where the knowledge about GIS technology and its accessibility is limited. The presented review briefly explains the basic features of GIS and discusses exemplary studies where this technology has been successfully used for monitoring and analysing pesticide pollution and its impact on public health.

  5. Distinguishing Selection Bias and Confounding Bias in Comparative Effectiveness Research.

    Science.gov (United States)

    Haneuse, Sebastien

    2016-04-01

    Comparative effectiveness research (CER) aims to provide patients and physicians with evidence-based guidance on treatment decisions. As researchers conduct CER they face myriad challenges. Although inadequate control of confounding is the most-often cited source of potential bias, selection bias that arises when patients are differentially excluded from analyses is a distinct phenomenon with distinct consequences: confounding bias compromises internal validity, whereas selection bias compromises external validity. Despite this distinction, however, the label "treatment-selection bias" is being used in the CER literature to denote the phenomenon of confounding bias. Motivated by an ongoing study of treatment choice for depression on weight change over time, this paper formally distinguishes selection and confounding bias in CER. By formally distinguishing selection and confounding bias, this paper clarifies important scientific, design, and analysis issues relevant to ensuring validity. First is that the 2 types of biases may arise simultaneously in any given study; even if confounding bias is completely controlled, a study may nevertheless suffer from selection bias so that the results are not generalizable to the patient population of interest. Second is that the statistical methods used to mitigate the 2 biases are themselves distinct; methods developed to control one type of bias should not be expected to address the other. Finally, the control of selection and confounding bias will often require distinct covariate information. Consequently, as researchers plan future studies of comparative effectiveness, care must be taken to ensure that all data elements relevant to both confounding and selection bias are collected.

  6. Intergroup bias.

    Science.gov (United States)

    Hewstone, Miles; Rubin, Mark; Willis, Hazel

    2002-01-01

    This chapter reviews the extensive literature on bias in favor of in-groups at the expense of out-groups. We focus on five issues and identify areas for future research: (a) measurement and conceptual issues (especially in-group favoritism vs. out-group derogation, and explicit vs. implicit measures of bias); (b) modern theories of bias highlighting motivational explanations (social identity, optimal distinctiveness, uncertainty reduction, social dominance, terror management); (c) key moderators of bias, especially those that exacerbate bias (identification, group size, status and power, threat, positive-negative asymmetry, personality and individual differences); (d) reduction of bias (individual vs. intergroup approaches, especially models of social categorization); and (e) the link between intergroup bias and more corrosive forms of social hostility.

  7. Interpretation biases in paranoia.

    Science.gov (United States)

    Savulich, George; Freeman, Daniel; Shergill, Sukhi; Yiend, Jenny

    2015-01-01

    Information in the environment is frequently ambiguous in meaning. Emotional ambiguity, such as the stare of a stranger, or the scream of a child, encompasses possible good or bad emotional consequences. Those with elevated vulnerability to affective disorders tend to interpret such material more negatively than those without, a phenomenon known as "negative interpretation bias." In this study we examined the relationship between vulnerability to psychosis, measured by trait paranoia, and interpretation bias. One set of material permitted broadly positive/negative (valenced) interpretations, while another allowed more or less paranoid interpretations, allowing us to also investigate the content specificity of interpretation biases associated with paranoia. Regression analyses (n=70) revealed that trait paranoia, trait anxiety, and cognitive inflexibility predicted paranoid interpretation bias, whereas trait anxiety and cognitive inflexibility predicted negative interpretation bias. In a group comparison those with high levels of trait paranoia were negatively biased in their interpretations of ambiguous information relative to those with low trait paranoia, and this effect was most pronounced for material directly related to paranoid concerns. Together these data suggest that a negative interpretation bias occurs in those with elevated vulnerability to paranoia, and that this bias may be strongest for material matching paranoid beliefs. We conclude that content-specific biases may be important in the cause and maintenance of paranoid symptoms.

  8. No bias of ignored bilaterality when analysing the revision risk of knee prostheses: Analysis of a population based sample of 44,590 patients with 55,298 knee prostheses from the national Swedish Knee Arthroplasty Register

    Directory of Open Access Journals (Sweden)

    Ranstam Jonas

    2003-02-01

    Full Text Available Abstract Background The current practice of the Swedish Knee Register is not to take into consideration if one or both knees in a patient are subject to surgery when evaluating risk of revision after arthroplasty. Risk calculations are typically done by statistical methods, such as Kaplan-Meier analyses and Cox's proportional hazards models, that are based on the assumption that observed events are independent, and this is rarely appreciated. The purpose of this study was to investigate if ignoring bilateral operations when using these methods biases the results. Methods The bias of not taking bilateral operations into account was investigated by statistically analysing 55 298 prostheses in 44 590 patients, undergoing knee arthroplasty surgery in Sweden during 1985–1999, using traditional proportional hazards analysis, which assumes that all observations are independent, and a shared gamma frailty model, which allows patients to contribute repeated observations. Results The effect of neglecting bilateral prostheses is minute, possibly because bilateral prosthesis failure is a rare event. Conclusion We conclude that the revision risk of knee prostheses in general can be analysed without consideration for subject dependency, at least in study populations with a relatively low proportion of subjects having experienced bilateral revisions.

  9. Racial bias in federal nutrition policy, Part I: The public health implications of variations in lactase persistence.

    Science.gov (United States)

    Bertron, P; Barnard, N D; Mills, M

    1999-03-01

    The Dietary Guidelines for Americans from the basis for all federal nutrition programs and incorporate the Food Guide Pyramid, a tool to educate consumers on putting the Guidelines into practice. The Pyramid recommends two to three daily servings of dairy products. However, research has shown that lactase nonpersistence, the loss of enzymes that digest the milk sugar lactose, occurs in a majority of African-, Asian-, Hispanic-, and Native-American individuals. Whites are less likely to develop lactase nonpersistence and less likely to have symptoms when it does occur. Calcium is available in other foods that do not contain lactose. Osteoporosis is less common among African Americans and Mexican Americans than among whites, and there is little evidence that dairy products have an effect on osteoporosis among racial minorities. Evidence suggests that a modification of federal nutrition policies, making dairy-product use optional in light of other calcium sources, may be a helpful public health measure.

  10. Implementation of a publication strategy in the context of reporting biases. A case study based on new documents from Neurontin litigation.

    Science.gov (United States)

    Vedula, S Swaroop; Goldman, Palko S; Rona, Ilyas J; Greene, Thomas M; Dickersin, Kay

    2012-08-13

    Previous studies have documented strategies to promote off-label use of drugs using journal publications and other means. Few studies have presented internal company communications that discussed financial reasons for manipulating the scholarly record related to off-label indications. The objective of this study was to build on previous studies to illustrate implementation of a publication strategy by the drug manufacturer for four off-label uses of gabapentin (Neurontin, Pfizer, Inc.): migraine prophylaxis, treatment of bipolar disorders, neuropathic pain, and nociceptive pain. We included in this study internal company documents, email correspondence, memoranda, study protocols and reports that were made publicly available in 2008 as part of litigation brought by consumers and health insurers against Pfizer for fraudulent sales practices in its marketing of gabapentin (see http://pacer.mad.uscourts.gov/dc/cgi-bin/recentops.pl?filename=saris/pdf/ucl%20opinion.pdf for the Court's findings).We reviewed documents pertaining to 20 clinical trials, 12 of which were published. We categorized our observations related to reporting biases and linked them with topics covered in internal documents, that is, deciding what should and should not be published and how to spin the study findings (re-framing study results to explain away unfavorable findings or to emphasize favorable findings); and where and when findings should be published and by whom. We present extracts from internal company marketing assessments recommending that Pfizer and Parke-Davis (Pfizer acquired Parke-Davis in 2000) adopt a publication strategy to conduct trials and disseminate trial findings for unapproved uses rather than an indication strategy to obtain regulatory approval. We show internal company email correspondence and documents revealing how publication content was influenced and spin was applied; how the company selected where trial findings would be presented or published; how publication of

  11. Implementation of a publication strategy in the context of reporting biases. A case study based on new documents from Neurontin® litigation

    Directory of Open Access Journals (Sweden)

    Vedula S

    2012-08-01

    Full Text Available Abstract Background Previous studies have documented strategies to promote off-label use of drugs using journal publications and other means. Few studies have presented internal company communications that discussed financial reasons for manipulating the scholarly record related to off-label indications. The objective of this study was to build on previous studies to illustrate implementation of a publication strategy by the drug manufacturer for four off-label uses of gabapentin (Neurontin®, Pfizer, Inc.: migraine prophylaxis, treatment of bipolar disorders, neuropathic pain, and nociceptive pain. Methods We included in this study internal company documents, email correspondence, memoranda, study protocols and reports that were made publicly available in 2008 as part of litigation brought by consumers and health insurers against Pfizer for fraudulent sales practices in its marketing of gabapentin (see http://pacer.mad.uscourts.gov/dc/cgi-bin/recentops.pl?filename=saris/pdf/ucl%20opinion.pdf for the Court’s findings. We reviewed documents pertaining to 20 clinical trials, 12 of which were published. We categorized our observations related to reporting biases and linked them with topics covered in internal documents, that is, deciding what should and should not be published and how to spin the study findings (re-framing study results to explain away unfavorable findings or to emphasize favorable findings; and where and when findings should be published and by whom. Results We present extracts from internal company marketing assessments recommending that Pfizer and Parke-Davis (Pfizer acquired Parke-Davis in 2000 adopt a publication strategy to conduct trials and disseminate trial findings for unapproved uses rather than an indication strategy to obtain regulatory approval. We show internal company email correspondence and documents revealing how publication content was influenced and spin was applied; how the company selected where trial

  12. On the reproducibility of meta-analyses : six practical recommendations

    NARCIS (Netherlands)

    Lakens, D.; Hilgard, J.; Staaks, J.

    2016-01-01

    Meta-analyses play an important role in cumulative science by combining information across multiple studies and attempting to provide effect size estimates corrected for publication bias. Research on the reproducibility of meta-analyses reveals that errors are common, and the percentage of effect si

  13. Hydrogen isotope correction for laser instrument measurement bias at low water vapor concentration using conventional isotope analyses: application to measurements from Mauna Loa Observatory, Hawaii.

    Science.gov (United States)

    Johnson, L R; Sharp, Z D; Galewsky, J; Strong, M; Van Pelt, A D; Dong, F; Noone, D

    2011-03-15

    The hydrogen and oxygen isotope ratios of water vapor can be measured with commercially available laser spectroscopy analyzers in real time. Operation of the laser systems in relatively dry air is difficult because measurements are non-linear as a function of humidity at low water concentrations. Here we use field-based sampling coupled with traditional mass spectrometry techniques for assessing linearity and calibrating laser spectroscopy systems at low water vapor concentrations. Air samples are collected in an evacuated 2 L glass flask and the water is separated from the non-condensable gases cryogenically. Approximately 2 µL of water are reduced to H(2) gas and measured on an isotope ratio mass spectrometer. In a field experiment at the Mauna Loa Observatory (MLO), we ran Picarro and Los Gatos Research (LGR) laser analyzers for a period of 25 days in addition to periodic sample collection in evacuated flasks. When the two laser systems are corrected to the flask data, they are strongly coincident over the entire 25 days. The δ(2)H values were found to change by over 200‰ over 2.5 min as the boundary layer elevation changed relative to MLO. The δ(2)H values ranged from -106 to -332‰, and the δ(18)O values (uncorrected) ranged from -12 to -50‰. Raw data from laser analyzers in environments with low water vapor concentrations can be normalized to the international V-SMOW scale by calibration to the flask data measured conventionally. Bias correction is especially critical for the accurate determination of deuterium excess in dry air.

  14. Impact of public programs on fertility and gender specific investment in human capital of children in rural India: cross sectional and time series analyses.

    Science.gov (United States)

    Duraisamy, P; Malathy, R

    1991-01-01

    Cross sectional and time series analyses are conducted with 1971 and 1981 rural district level data for India in order to estimate variations in program impacts on household decisionmaking concerning fertility, child mortality, and schooling; to analyze how the variation in public program subsidies and services influences sex specific investments in schooling; and to examine the bias in cross sectional estimates by employing fixed effects methodology. The theory of household production uses the framework development by Rosenzweig and Wolpin. The utility function is expressed as a function of families' desired number of children, sex specific investment in human capital of children measured by schooling of males and females, and a composite consumption good. Budget constraints are characterized in terms of the biological supply of births or natural fertility, the number of births averted by fertility control, exogenous money income, the prices of number of children, contraceptives, child schooling, and consumption of goods. Demand functions are constructed from maximizing the utility function subject to the budget constraint. Data constitute 40% of the total districts and 50% of the rural population. The empirical specification of the linear model and variable description are provided. Other explanatory variables included are adult educational attainment; % of scheduled castes and tribes and % Muslim; and % rural population. Estimation methods are described and justification is provided for the use of ordinary least squares and fixed effects methods. The results of the cross sectional analysis reveal that own-program effects of family planning and primary health centers reduced family size in 1971 and 81. The increase in secondary school enrollment is evidenced in only 1971. There is a significant effect of family planning (FP) clinics on the demand for surviving children only in 1971. The presence of a seconary school in a village reduces the demand for children in

  15. Complete mitochondrial genome sequences of three bats species and whole genome mitochondrial analyses reveal patterns of codon bias and lend support to a basal split in Chiroptera.

    Science.gov (United States)

    Meganathan, P R; Pagan, Heidi J T; McCulloch, Eve S; Stevens, Richard D; Ray, David A

    2012-01-15

    Order Chiroptera is a unique group of mammals whose members have attained self-powered flight as their main mode of locomotion. Much speculation persists regarding bat evolution; however, lack of sufficient molecular data hampers evolutionary and conservation studies. Of ~1200 species, complete mitochondrial genome sequences are available for only eleven. Additional sequences should be generated if we are to resolve many questions concerning these fascinating mammals. Herein, we describe the complete mitochondrial genomes of three bats: Corynorhinus rafinesquii, Lasiurus borealis and Artibeus lituratus. We also compare the currently available mitochondrial genomes and analyze codon usage in Chiroptera. C. rafinesquii, L. borealis and A. lituratus mitochondrial genomes are 16438 bp, 17048 bp and 16709 bp, respectively. Genome organization and gene arrangements are similar to other bats. Phylogenetic analyses using complete mitochondrial genome sequences support previously established phylogenetic relationships and suggest utility in future studies focusing on the evolutionary aspects of these species. Comprehensive analyses of available bat mitochondrial genomes reveal distinct nucleotide patterns and synonymous codon preferences corresponding to different chiropteran families. These patterns suggest that mutational and selection forces are acting to different extents within Chiroptera and shape their mitochondrial genomes.

  16. Communicating human biomonitoring results to ensure policy coherence with public health recommendations: analysing breastmilk whilst protecting, promoting and supporting breastfeeding

    Directory of Open Access Journals (Sweden)

    Arendt Maryse

    2008-01-01

    Full Text Available Abstract This article addresses the problem of how to ensure consistency in messages communicating public health recommendations on environmental health and on child health. The World Health Organization states that the protection, promotion and support of breastfeeding rank among the most effective interventions to improve child survival. International public health policy recommends exclusive breastfeeding for six months, followed by continued breastfeeding with the addition of safe and adequate complementary foods for two years and beyond. Biomonitoring of breastmilk is used as an indicator of environmental pollution ending up in mankind. This article will therefore present the biomonitoring results of concentrations of residues in breastmilk in a wider context. These results are the mirror that reflects the chemical substances accumulated in the bodies of both men and women in the course of a lifetime. The accumulated substances in our bodies may have an effect on male or female reproductive cells; they are present in the womb, directly affecting the environment of the fragile developing foetus; they are also present in breastmilk. Evidence of man-made chemical residues in breastmilk can provide a shock tactic to push for stronger laws to protect the environment. However, messages about chemicals detected in breastmilk can become dramatized by the media and cause a backlash against breastfeeding, thus contradicting the public health messages issued by the World Health Organization. Analyses of breastmilk show the presence of important nutritional components and live protective factors active in building up the immune system, in gastro intestinal maturation, in immune defence and in providing antiviral, antiparasitic and antibacterial activity. Through cohort studies researchers in environmental health have concluded that long-term breastfeeding counterbalances the effect of prenatal exposure to chemicals causing delay in mental and

  17. Bias neglect: a blind spot in the evaluation of scientific results.

    Science.gov (United States)

    Strickland, Brent; Mercier, Hugo

    2014-01-01

    Experimenter bias occurs when scientists' hypotheses influence their results, even if involuntarily. Meta-analyses have suggested that in some domains, such as psychology, up to a third of the studies could be unreliable due to such biases. A series of experiments demonstrates that while people are aware of the possibility that scientists can be more biased when the conclusions of their experiments fit their initial hypotheses, they robustly fail to appreciate that they should also be more sceptical of such results. This is true even when participants read descriptions of studies that have been shown to be biased. Moreover, participants take other sources of bias-such as financial incentives-into account, showing that this bias neglect may be specific to theory-driven hypothesis testing. In combination with a common style of scientific reporting, bias neglect could lead the public to accept premature conclusions.

  18. Unpacking the Evidence of Gender Bias

    Science.gov (United States)

    Fulmer, Connie L.

    2010-01-01

    The purpose of this study was to investigate gender bias in pre-service principals using the Gender-Leader Implicit Association Test. Analyses of student-learning narratives revealed how students made sense of gender bias (biased or not-biased) and how each reacted to evidence (surprised or not-surprised). Two implications were: (1) the need for…

  19. The potential to forgo social welfare gains through overrelianceon cost effectiveness/cost utility analyses in the evidence base for public health.

    Science.gov (United States)

    Cohen, D R; Patel, N

    2009-01-01

    Economic evaluations of clinical treatments most commonly take the form of cost effectiveness or cost utility analyses. This is appropriate since the main-sometimes the only-benefit of such interventions is increased health. The majority of economic evaluations in public health, however, have also been assessed using these techniques when arguably cost benefit analyses would in many cases have been more appropriate, given its ability to take account of nonhealth benefits as well. An examination of the nonhealth benefits from a sample of studies featured in a recent review of economic evaluations in public health illustrates how overfocusing on cost effectiveness/cost utility analyses may lead to forgoing potential social welfare gains from programmes in public health. Prior to evaluation, programmes should be considered in terms of the potential importance of nonhealth benefits and where these are considerable would be better evaluated by more inclusive economic evaluation techniques.

  20. Using IRT Approach to Detect Gender Biased Items in Public Examinations: A Case Study from the Botswana Junior Certificate Examination in Mathematics

    Science.gov (United States)

    Adedoyin, O. O.

    2010-01-01

    This is a quantitative study, which attempted to detect gender bias test items from the Botswana Junior Certificate Examination in mathematics. To detect gender bias test items, a randomly selected sample of 4000 students responses to mathematics paper 1 of the Botswana Junior Certificate examination were selected from 36,000 students who sat for…

  1. Analysing the Present: Drawing on the Legacy of Vere Foster in Public Policy Debate on Futures of Schools

    Science.gov (United States)

    Carr, John; Beckett, Lori

    2016-01-01

    This paper sets out a framing analysis for a public policy debate on the future of schools that resonates with practitioners in teaching and teacher education on the island of Ireland, north and south, but also in other countries. This is informed by a democratic impulse to facilitate public policy debates, particularly on the ways schools and…

  2. Analysing the Present: Drawing on the Legacy of Vere Foster in Public Policy Debate on Futures of Schools

    Science.gov (United States)

    Carr, John; Beckett, Lori

    2016-01-01

    This paper sets out a framing analysis for a public policy debate on the future of schools that resonates with practitioners in teaching and teacher education on the island of Ireland, north and south, but also in other countries. This is informed by a democratic impulse to facilitate public policy debates, particularly on the ways schools and…

  3. Discrepancies in sample size calculations and data analyses reported in randomised trials: comparison of publications with protocols

    DEFF Research Database (Denmark)

    Chan, A.W.; Hrobjartsson, A.; Jorgensen, K.J.

    2008-01-01

    in 1994-5 by the scientific-ethics committees for Copenhagen and Frederiksberg, Denmark (n=70). MAIN OUTCOME MEASURE: Proportion of protocols and publications that did not provide key information about sample size calculations and statistical methods; proportion of trials with discrepancies between......OBJECTIVE: To evaluate how often sample size calculations and methods of statistical analysis are pre-specified or changed in randomised trials. DESIGN: Retrospective cohort study. Data source Protocols and journal publications of published randomised parallel group trials initially approved...... information presented in the protocol and the publication. RESULTS: Only 11/62 trials described existing sample size calculations fully and consistently in both the protocol and the publication. The method of handling protocol deviations was described in 37 protocols and 43 publications. The method...

  4. Risk of bias in research in oral and maxillofacial surgery.

    Science.gov (United States)

    Oomens, M A E M; Heymans, M W; Forouzanfar, T

    2013-12-01

    The risk of bias is important in the interpretation of the results of research. The aim of this review was to evaluate the risk of bias in randomised controlled trials (RCTs) in oral and maxillofacial surgery (OMFS) over a 10-year period. We searched databases of publications for RCTs published between January 2000 and January 2010. Papers were assessed with 2 up-to-date logical quality lists, the Delphi list and the Jadad scale. Those papers with a low risk of bias were given a Jadad score ≥4 (range 0-5) and a Delphi score ≥6 (range 0-9). A total of 230 papers met the inclusion criteria, and only 41 (18%) were assessed as being at low risk. Most of those included did not correctly describe such important items for risk of bias as method of randomisation (n=124, 54%), concealment of allocation (n=143, 62%), blinding (n=175, 76%), and intention-to-treat analyses (n=182, 79%). In the fields of implantology, traumatology, obstructive sleep apnoea syndrome, and extractions, no paper had a low risk of bias. This systematic review has shown a shortage of research in OMFS with a low risk of bias published over a 10-year period. Further research should concentrate on better describing items at important risk of bias.

  5. Typologie des services d’eau potable et d’assainissement collectif, parangonnage et analyse de la performance des services publics

    OpenAIRE

    Wittner, C.

    2011-01-01

    / La présente étude exploite les données de la base extraites du SISPEA relatives à l’exercice 2009 (indicateurs descriptifs et de performance des services publics d’eau et d’assainissement). Une typologie des services est établie en utilisant la méthode d’analyse factorielle à composante multiple. Elle aboutit à la caractérisation de 5 classes de services publics d’eau potable et à la détermination d’une première hiérarchie de critères discriminant les ser...

  6. STUDY OF THE MICROBIOLOGICAL ANALYSES CARRIED OUT AT THE LABORATORY OF A PUBLIC HOSPITAL (CHR AL IDRISSI OF KENITRA

    Directory of Open Access Journals (Sweden)

    A. Aziane

    2015-07-01

    Full Text Available The present work attempts to make a study on the microbiological analyses of pathogens (bacteria or viruses that are at the origin of the human disease, carried out in the laboratory of microbiological analyses of hospital regional CHR al IDRISSI of Kenitra for a period that extends from the year 2007 to 2009 in order to clarify the methodology of work and the problem of infections in developing countries. Our work is based on the monthly inventory of pathogens (E. Coli, Staphylococcus, Streptococcus, Klebsiella, Enterobacter, Candida albicans, Pseudomonas, Syphilis, hepatitis viruses and HIV in deferens samples (Urine, Pus, saddle, like and Serum in patients in relation with total analyses carried out for 3 years. Then we follow their development during this period with the analysis of the results.

  7. STUDY OF THE MICROBIOLOGICAL ANALYSES CARRIED OUT AT THE LABORATORY OF A PUBLIC HOSPITAL (CHR AL IDRISSI OF KENITRA

    Directory of Open Access Journals (Sweden)

    A. Aziane

    2014-12-01

    Full Text Available The present work attempts to make a study on the microbiological analyses of pathogens (bacteria or viruses that are at the origin of the human disease, carried out in the laboratory of microbiological analyses of hospital regional CHR al IDRISSI of Kenitra for a period that extends from the year 2007 to 2009 in order to clarify the methodology of work and the problem of infections in developing countries. Our work is based on the monthly inventory of pathogens (E. Coli, Staphylococcus, Streptococcus, Klebsiella, Enterobacter, Candida albicans, Pseudomonas, Syphilis, hepatitis viruses and HIV in deferens samples (Urine, Pus, saddle, like and Serum in patients in relation with total analyses carried out for 3 years. Then we follow their development during this period with the analysis of the results.

  8. Nutritional composition, assessed by chemical analyses, of prepared foods available for primary-school children: a comparison of public and private schools.

    Science.gov (United States)

    Weber, Márcia L; Morais, Tania B

    2010-11-01

    To assess the nutritional quality of prepared foods available to primary-school children. Prepared foods available in a public and private school were sampled daily for 4 weeks (a total of forty-five samples) and chemically analysed for protein, fat, carbohydrate, iron, salt and sodium. The results were compared to the nutritional standards for children aged 7-10 years. Alfenas, south-eastern Brazil. The concentration of protein, lipid, iron and sodium and the energy values of the foods at the private school were significantly higher than those at the public school. No differences were seen in the carbohydrate and salt values. The range of macronutrients was more balanced at the public school in relation to fat and protein. Foods at the private school were, in general, energy-dense. At both the public and private school, they provided the minimum energy and iron. Salt content was over twice the maximum amount, and that for sodium was over three times the amount, in both the public and private school. Overall, foods prepared at the public school were better nutritional quality than those at the private school and those offered in public schools in some developed countries. This finding can probably be explained by the fact that a nutritionist, as required by law, was responsible for planning the menus at the public school. However, corrective action is needed to adjust for the wide variability in energy and nutrient content during weekdays and in the sodium content of prepared foods available in both the public and private school.

  9. Bias-Based Harassment in New York City Public Schools: A Report Card on the Department of Education's Implementation of Chancellor's Regulation A-832

    Science.gov (United States)

    Asian American Legal Defense and Education Fund, 2009

    2009-01-01

    On September 3, 2008, Mayor Michael Bloomberg and Schools Chancellor Joel Klein announced Chancellor's Regulation A-832, which established a procedure for addressing student-to-student bias-based harassment, intimidation, and bullying. Community groups and advocates stood with the Mayor and Department of Education (DOE) leadership in announcing…

  10. Technological innovations and public politics: social environmental analyses in the context of sugar-ethanol industrial activities in Brazil

    Directory of Open Access Journals (Sweden)

    Charlene Maria C. de Ávila Plaza

    2008-08-01

    Full Text Available The present article aims at discussing the importance of the technological innovations as propellers of the economic development of the nations as well as the role of the public politics directed toward the socioeconomics and institutional agents who are a part of the productive and innovative chain of the country. We try to analyze the sugar-ethanol sector and its consequences concerning the environmental aspects, being emphasized the State of Goiás and the “Cerrado” bioma. In the social aspects, we demonstrate the necessity to conciliate economic development with social-environmental sustainability, to propitiate a healthy environment and improvement of the working conditions and life for the citizens who perform the functions of sugar cane cutters of this sector. It is important to emphasize that the article does not intend to underestimate the economic practices of the sugar-ethanol companies, but to analyze certain aspects concerning the environment and the social factor, so that consistent politics is implemented in order to promote sustainability, balanced with enterprise and governmental responsibilities and commitments allied to the tripod: economy, environment and society. Key-words: Technological innovation; Public Politics; Sustainable Development; Sugar-ethanol Sector; Biofuels

  11. Biases from neutrino bias: to worry or not to worry?

    OpenAIRE

    Raccanelli, Alvise; Verde, Licia; Villaescusa-Navarro, Francisco

    2017-01-01

    The relation between the halo field and the matter fluctuations (halo bias), in the presence of massive neutrinos depends on the total neutrino mass, massive neutrinos introduce an additional scale-dependence of the bias which is usually neglected in cosmological analyses. We investigate the magnitude of the systematic effect on interesting cosmological parameters induced by neglecting this scale dependence, finding that while it is not a problem for current surveys, it is non-negligible for ...

  12. Epistemological and ethical assessment of obesity bias in industrialized countries

    Directory of Open Access Journals (Sweden)

    Azétsop Jacquineau

    2011-12-01

    Full Text Available Abstract Bernard Lonergan's cognitive theory challenges us to raise questions about both the cognitive process through which obesity is perceived as a behaviour change issue and the objectivity of such a moral judgment. Lonergan's theory provides the theoretical tools to affirm that anti-fat discrimination, in the United States of America and in many industrialized countries, is the result of both a group bias that resists insights into the good of other groups and a general bias of anti-intellectualism that tends to set common sense against insights that require any thorough scientific analyses. While general bias diverts the public's attention away from the true aetiology of obesity, group bias sustains an anti-fat culture that subtly legitimates discriminatory practices and policies against obese people. Although anti-discrimination laws may seem to be a reasonable way of protecting obese and overweight individuals from discrimination, obesity bias can be best addressed by reframing the obesity debate from an environmental perspective from which tools and strategies to address both the social and individual determinants of obesity can be developed. Attention should not be concentrated on individuals' behaviour as it is related to lifestyle choices, without giving due consideration to the all-encompassing constraining factors which challenge the social and rational blindness of obesity bias.

  13. [Prevalence and factors associated with intimate partner abuse in female users of public health services in Mexico: a comparative analyses].

    Science.gov (United States)

    Ávila-Burgos, Leticia; Valdez-Santiagob, Rosario; Barroso-Quiab, Abigail; Híjar, Martha; Rojas, Rosalba; Del Río-Zolezzi, Aurora

    2014-01-01

    To analyze the evolution of the prevalence in intimate partner violence during the years 2003 and 2006 in Mexico, identifying factors associated with its severity, comparing our results with findings from 2003. Data from the Encuesta Nacional de Violencia contra las Mujeres (ENVIM 2006) was used; it has urban-rural national representation of female users of Mexican public health services. A total of 22,318 women above 14 years of age were interviewed. A multinomial logistic regression model was adjusted. The dependent variable was the Index of Intimate Partner Abuse. Intimate partner abuse increased 17% in comparison to the year 2003. Women's personal history of childhood abuse (ORA= 5.12, 95% CI4.15-6.30) and rape (ORA = 3.5, 95% CI = 2.66-4.62) were the most important women's factors that were found associated with severe violence. Male partner's daily alcohol consumption increased eleven fold the possibility of severe violence; higher disagreement with traditional female gender roles and higher education of both partners were protective factors. Factors associated with violence and their severities were consistent with findings reported in 2003. Intimate partner violence is a highly prevalent social problem which requires comprehensive strategies supporting empowerment of women through higher education, early detection and care of those battered, as well as structured interventions to prevent violence in future generations.

  14. Assessment and integration of publicly available SAGE, cDNA microarray, and oligonucleotide microarray expression data for global coexpression analyses.

    Science.gov (United States)

    Griffith, Obi L; Pleasance, Erin D; Fulton, Debra L; Oveisi, Mehrdad; Ester, Martin; Siddiqui, Asim S; Jones, Steven J M

    2005-10-01

    Large amounts of gene expression data from several different technologies are becoming available to the scientific community. A common practice is to use these data to calculate global gene coexpression for validation or integration of other "omic" data. To assess the utility of publicly available datasets for this purpose we have analyzed Homo sapiens data from 1202 cDNA microarray experiments, 242 SAGE libraries, and 667 Affymetrix oligonucleotide microarray experiments. The three datasets compared demonstrate significant but low levels of global concordance (rc<0.11). Assessment against Gene Ontology (GO) revealed that all three platforms identify more coexpressed gene pairs with common biological processes than expected by chance. As the Pearson correlation for a gene pair increased it was more likely to be confirmed by GO. The Affymetrix dataset performed best individually with gene pairs of correlation 0.9-1.0 confirmed by GO in 74% of cases. However, in all cases, gene pairs confirmed by multiple platforms were more likely to be confirmed by GO. We show that combining results from different expression platforms increases reliability of coexpression. A comparison with other recently published coexpression studies found similar results in terms of performance against GO but with each method producing distinctly different gene pair lists.

  15. 农村公众风险认知偏差的非正式制度因素研究%Informal Institutional Factors of Rural Public risk Perception Bias

    Institute of Scientific and Technical Information of China (English)

    龙云; 李彬

    2015-01-01

    In the sudden rural public events, the public risk perception bias is an important factor to the public psychological panic. so the research of public risk perception bias and its influence factors is an important part of the research work. On the basis of defining the deviation of the rural emergency and public risk, the influence mechanism of the traditional culture and customs of rural society is analyzed, and the relevant countermeasures are put forward to improve the education level of rural residents, to promote the effective transfer of rural information, and to strengthen the communication between government and people.%农村突发事件中公众风险认知偏差是公众心理恐慌产生的重要影响因素,因此公众风险认知偏差及其影响因子的研究是突发事件管控研究工作中的重要一环。在界定农村突发事件和公众风险认知偏差的基础上,分析农村社会的传统文化习惯习俗等非正式制度对公众风险认知偏差的影响机理,提出相关对策如下:提高农村居民的教育水平;促进农村信息的有效传递;加强政府与民众之间的沟通。

  16. Cost-benefit analysis of the energy conservation scheme of a regional public utility; Kosten-Nutzen-Analyse des Energiespar-Programms eines regionalen Energieversorgers

    Energy Technology Data Exchange (ETDEWEB)

    Engel, H. [Energie-Versorgung Schwaben AG, Stuttgart (Germany). Abt. Sondervertragskunden; Karel, A. [Heag Versorgungs-AG, Darmstadt (Germany). Abt. Anwendungsberatung; Setzer, M. [Technische Hochschule Darmstadt (Germany). Inst. fuer Volkswirtschaftslehre

    1996-04-22

    Public utilities increasingly advocate energy conservation, not additional power consumption. With this regard, Heag AG, in its ``energy conservation scheme 2000``, offers a broad range of possibilities. It includes incentives for energy conservation and renewable energy use. As an instrument of analysis for this scheme, cost-benefit analysis was chosen. The authors describe the scheme and test the applicability of cost-benefit analysis. (orig.) [Deutsch] Die EVU setzen sich zunehmend fuer das Energieeinsparen ein, statt fuer zusaetzlichen Stromabsatz. Die Heag Versorgungs-AG bietet dazu ein breit angelegtes Foerderprogramm: `Energiespar-Aktion 2000`. Im Rahmen dieser Aktion werden Massnahmen zur Energieeinsparung und Nutzung regenerativer Energie finanziell gefoerdert. Als Analyseinstrument fuer die Energiespar-Aktion wurde die Kosten-Nutzen-Analyse gewaehlt. Die Verfasser erlaeutern die Energiespar-Aktion und pruefen auch die Anwendbarkeit der Kosten-Nutzen-Analyse. (orig.)

  17. Implementation of New Public Management in Norwegian Universities

    Science.gov (United States)

    Frolich, Nicoline

    2005-01-01

    This article analyses the implementation of market-type mechanisms in the management of universities. The question of which cultural biases have been used in the implementation of New Public Management (NPM) in Norwegian universities is discussed. Cultural theory, institutional theory, and public policy studies are applied to the analysis of a…

  18. Assessing public speaking fear with the short form of the Personal Report of Confidence as a Speaker scale: confirmatory factor analyses among a French-speaking community sample.

    Science.gov (United States)

    Heeren, Alexandre; Ceschi, Grazia; Valentiner, David P; Dethier, Vincent; Philippot, Pierre

    2013-01-01

    The main aim of this study was to assess the reliability and structural validity of the French version of the 12-item version of the Personal Report of Confidence as Speaker (PRCS), one of the most promising measurements of public speaking fear. A total of 611 French-speaking volunteers were administered the French versions of the short PRCS, the Liebowitz Social Anxiety Scale, the Fear of Negative Evaluation scale, as well as the Trait version of the Spielberger State-Trait Anxiety Inventory and the Beck Depression Inventory-II, which assess the level of anxious and depressive symptoms, respectively. Regarding its structural validity, confirmatory factor analyses indicated a single-factor solution, as implied by the original version. Good scale reliability (Cronbach's alpha = 0.86) was observed. The item discrimination analysis suggested that all the items contribute to the overall scale score reliability. The French version of the short PRCS showed significant correlations with the Liebowitz Social Anxiety Scale (r = 0.522), the Fear of Negative Evaluation scale (r = 0.414), the Spielberger State-Trait Anxiety Inventory (r = 0.516), and the Beck Depression Inventory-II (r = 0.361). The French version of the short PRCS is a reliable and valid measure for the evaluation of the fear of public speaking among a French-speaking sample. These findings have critical consequences for the measurement of psychological and pharmacological treatment effectiveness in public speaking fear among a French-speaking sample.

  19. Tickled to death: analysing public perceptions of 'cute' videos of threatened species (slow lorises - Nycticebus spp. on Web 2.0 sites.

    Directory of Open Access Journals (Sweden)

    K Anne-Isola Nekaris

    Full Text Available BACKGROUND: The internet is gaining importance in global wildlife trade and changing perceptions of threatened species. There is little data available to examine the impact that popular Web 2.0 sites play on public perceptions of threatened species. YouTube videos portraying wildlife allow us to quantify these perceptions. METHODOLOGY/PRINCIPAL FINDINGS: Focussing on a group of threatened and globally protected primates, slow lorises, we quantify public attitudes towards wildlife conservation by analysing 12,411 comments and associated data posted on a viral YouTube video 'tickling slow loris' over a 33-months period. In the initial months a quarter of commentators indicated wanting a loris as a pet, but as facts about their conservation and ecology became more prevalent this dropped significantly. Endorsements, where people were directed to the site by celebrities, resulted mostly in numerous neutral responses with few links to conservation or awareness. Two conservation-related events, linked to Wikipedia and the airing of a television documentary, led to an increase in awareness, and ultimately to the removal of the analysed video. CONCLUSIONS/SIGNIFICANCE: Slow loris videos that have gone viral have introduced these primates to a large cross-section of society that would not normally come into contact with them. Analyses of webometric data posted on the internet allow us quickly to gauge societal sentiments. We showed a clear temporal change in some views expressed but without an apparent increase in knowledge about the conservation plight of the species, or the illegal nature of slow loris trade. Celebrity endorsement of videos showing protected wildlife increases visits to such sites, but does not educate about conservation issues. The strong desire of commentators to express their want for one as a pet demonstrates the need for Web 2.0 sites to provide a mechanism via which illegal animal material can be identified and policed.

  20. Tickled to Death: Analysing Public Perceptions of ‘Cute’ Videos of Threatened Species (Slow Lorises – Nycticebus spp.) on Web 2.0 Sites

    Science.gov (United States)

    Nekaris, By K. Anne-Isola; Campbell, Nicola; Coggins, Tim G.; Rode, E. Johanna; Nijman, Vincent

    2013-01-01

    Background The internet is gaining importance in global wildlife trade and changing perceptions of threatened species. There is little data available to examine the impact that popular Web 2.0 sites play on public perceptions of threatened species. YouTube videos portraying wildlife allow us to quantify these perceptions. Methodology/Principal Findings Focussing on a group of threatened and globally protected primates, slow lorises, we quantify public attitudes towards wildlife conservation by analysing 12,411 comments and associated data posted on a viral YouTube video ‘tickling slow loris’ over a 33-months period. In the initial months a quarter of commentators indicated wanting a loris as a pet, but as facts about their conservation and ecology became more prevalent this dropped significantly. Endorsements, where people were directed to the site by celebrities, resulted mostly in numerous neutral responses with few links to conservation or awareness. Two conservation-related events, linked to Wikipedia and the airing of a television documentary, led to an increase in awareness, and ultimately to the removal of the analysed video. Conclusions/Significance Slow loris videos that have gone viral have introduced these primates to a large cross-section of society that would not normally come into contact with them. Analyses of webometric data posted on the internet allow us quickly to gauge societal sentiments. We showed a clear temporal change in some views expressed but without an apparent increase in knowledge about the conservation plight of the species, or the illegal nature of slow loris trade. Celebrity endorsement of videos showing protected wildlife increases visits to such sites, but does not educate about conservation issues. The strong desire of commentators to express their want for one as a pet demonstrates the need for Web 2.0 sites to provide a mechanism via which illegal animal material can be identified and policed. PMID:23894432

  1. Tickled to death: analysing public perceptions of 'cute' videos of threatened species (slow lorises - Nycticebus spp.) on Web 2.0 sites.

    Science.gov (United States)

    Anne-Isola Nekaris, K; Nekaris, By K Anne-Isola; Campbell, Nicola; Coggins, Tim G; Rode, E Johanna; Nijman, Vincent

    2013-01-01

    The internet is gaining importance in global wildlife trade and changing perceptions of threatened species. There is little data available to examine the impact that popular Web 2.0 sites play on public perceptions of threatened species. YouTube videos portraying wildlife allow us to quantify these perceptions. Focussing on a group of threatened and globally protected primates, slow lorises, we quantify public attitudes towards wildlife conservation by analysing 12,411 comments and associated data posted on a viral YouTube video 'tickling slow loris' over a 33-months period. In the initial months a quarter of commentators indicated wanting a loris as a pet, but as facts about their conservation and ecology became more prevalent this dropped significantly. Endorsements, where people were directed to the site by celebrities, resulted mostly in numerous neutral responses with few links to conservation or awareness. Two conservation-related events, linked to Wikipedia and the airing of a television documentary, led to an increase in awareness, and ultimately to the removal of the analysed video. Slow loris videos that have gone viral have introduced these primates to a large cross-section of society that would not normally come into contact with them. Analyses of webometric data posted on the internet allow us quickly to gauge societal sentiments. We showed a clear temporal change in some views expressed but without an apparent increase in knowledge about the conservation plight of the species, or the illegal nature of slow loris trade. Celebrity endorsement of videos showing protected wildlife increases visits to such sites, but does not educate about conservation issues. The strong desire of commentators to express their want for one as a pet demonstrates the need for Web 2.0 sites to provide a mechanism via which illegal animal material can be identified and policed.

  2. Assessing public speaking fear with the short form of the Personal Report of Confidence as a Speaker scale: confirmatory factor analyses among a French-speaking community sample

    Directory of Open Access Journals (Sweden)

    Heeren A

    2013-05-01

    Full Text Available Alexandre Heeren,1,2 Grazia Ceschi,3 David P Valentiner,4 Vincent Dethier,1 Pierre Philippot11Université Catholique de Louvain, Louvain-la-Neuve, Belgium; 2National Fund for Scientific Research, Brussels, Belgium; 3Department of Psychology, University of Geneva, Geneva, Switzerland; 4Department of Psychology, Northern Illinois University, DeKalb, IL, USABackground: The main aim of this study was to assess the reliability and structural validity of the French version of the 12-item version of the Personal Report of Confidence as Speaker (PRCS, one of the most promising measurements of public speaking fear.Methods: A total of 611 French-speaking volunteers were administered the French versions of the short PRCS, the Liebowitz Social Anxiety Scale, the Fear of Negative Evaluation scale, as well as the Trait version of the Spielberger State-Trait Anxiety Inventory and the Beck Depression Inventory-II, which assess the level of anxious and depressive symptoms, respectively.Results: Regarding its structural validity, confirmatory factor analyses indicated a single-factor solution, as implied by the original version. Good scale reliability (Cronbach’s alpha = 0.86 was observed. The item discrimination analysis suggested that all the items contribute to the overall scale score reliability. The French version of the short PRCS showed significant correlations with the Liebowitz Social Anxiety Scale (r = 0.522, the Fear of Negative Evaluation scale (r = 0.414, the Spielberger State-Trait Anxiety Inventory (r = 0.516, and the Beck Depression Inventory-II (r = 0.361.Conclusion: The French version of the short PRCS is a reliable and valid measure for the evaluation of the fear of public speaking among a French-speaking sample. These findings have critical consequences for the measurement of psychological and pharmacological treatment effectiveness in public speaking fear among a French-speaking sample.Keywords: social phobia, public speaking, confirmatory

  3. A Simulation Platform for Quantifying Survival Bias

    DEFF Research Database (Denmark)

    Mayeda, Elizabeth Rose; Tchetgen Tchetgen, Eric J; Power, Melinda C

    2016-01-01

    Bias due to selective mortality is a potential concern in many studies and is especially relevant in cognitive aging research because cognitive impairment strongly predicts subsequent mortality. Biased estimation of the effect of an exposure on rate of cognitive decline can occur when mortality i......-mortality situations. This simulation platform provides a flexible tool for evaluating biases in studies with high mortality, as is common in cognitive aging research.......Bias due to selective mortality is a potential concern in many studies and is especially relevant in cognitive aging research because cognitive impairment strongly predicts subsequent mortality. Biased estimation of the effect of an exposure on rate of cognitive decline can occur when mortality...... platform with which to quantify the expected bias in longitudinal studies of determinants of cognitive decline. We evaluated potential survival bias in naive analyses under several selective survival scenarios, assuming that exposure had no effect on cognitive decline for anyone in the population. Compared...

  4. Racially Biased Policing: Determinants of Citizen Perceptions

    Science.gov (United States)

    Weitzer, Ronald; Tuch, Steven A.

    2005-01-01

    The current controversy surrounding racial profiling in America has focused renewed attention on the larger issue of racial bias by the police. Yet little is known about the extent of police racial bias and even less about public perceptions of the problem. This article analyzes recent national survey data on citizens' views of and reported…

  5. Publications

    Directory of Open Access Journals (Sweden)

    2004-04-01

    Full Text Available Fabienne Blaise–« Une polémique tragique : le second volet de l’Ajax de Sophocle », Revue des Études Grecques 112, 1999, p. 383-408.–Traduction de Wilhelm Dilthey, Conception du monde et analyse de l’homme depuis la Renaissance et la Réforme, Paris (Cerf, collection Passages, 1999 (471 p..Jean Celeyrette,–La Physique de N. Oresme. Introduction.–« Le statut des mathématiques dans la Physique d’Oresme », Oriens Occidens 3, 2000, p. 91-113.–Jean Celeyrette -Edmond mazet, « La Hiérarchie des de...

  6. Awareness Reduces Racial Bias

    OpenAIRE

    2014-01-01

    Can raising awareness of racial bias subsequently reduce that bias? We address this question by exploiting the widespread media attention highlighting racial bias among professional basketball referees that occurred in May 2007 following the release of an academic study. Using new data, we confirm that racial bias persisted in the years after the study's original sample, but prior to the media coverage. Subsequent to the media coverage though, the bias completely disappeared. We examine poten...

  7. A catalog of biases in questionnaires.

    Science.gov (United States)

    Choi, Bernard C K; Pak, Anita W P

    2005-01-01

    Bias in questionnaires is an important issue in public health research. To collect the most accurate data from respondents, investigators must understand and be able to prevent or at least minimize bias in the design of their questionnaires. This paper identifies and categorizes 48 types of bias in questionnaires based on a review of the literature and offers an example of each type. The types are categorized according to three main sources of bias: the way a question is designed, the way the questionnaire as a whole is designed, and how the questionnaire is administered. This paper is intended to help investigators in public health understand the mechanism and dynamics of problems in questionnaire design and to provide a checklist for identifying potential bias in a questionnaire before it is administered.

  8. Professional Culture and Climate: Addressing Unconscious Bias

    Science.gov (United States)

    Knezek, Patricia

    2016-10-01

    Unconscious bias reflects expectations or stereotypes that influence our judgments of others (regardless of our own group). Everyone has unconscious biases. The end result of unconscious bias can be an accumulation of advantage or disadvantage that impacts the long term career success of individuals, depending on which biases they are subject to. In order to foster a professional culture and climate, being aware of these unconscious biases and mitigating against them is a first step. This is particularly important when judgements are needed, such as in cases for recruitment, choice of speakers for conferences, and even reviewing papers submitted for publication. This presentation will cover how unconscious bias manifests itself, what evidence exists to demonstrate it exists, and ways it can be addressed.

  9. Assessing the Bias in Communication Networks Sampled from Twitter

    CERN Document Server

    González-Bailón, Sandra; Rivero, Alejandro; Borge-Holthoefer, Javier; Moreno, Yamir

    2012-01-01

    We collect and analyse messages exchanged in Twitter using two of the platform's publicly available APIs (the search and stream specifications). We assess the differences between the two samples, and compare the networks of communication reconstructed from them. The empirical context is given by political protests taking place in May 2012: we track online communication around these protests for the period of one month, and reconstruct the network of mentions and re-tweets according to the two samples. We find that the search API over-represents the more central users and does not offer an accurate picture of peripheral activity; we also find that the bias is greater for the network of mentions. We discuss the implications of this bias for the study of diffusion dynamics and collective action in the digital era, and advocate the need for more uniform sampling procedures in the study of online communication.

  10. Analytical Bias Exceeding Desirable Quality Goal in 4 out of 5 Common Immunoassays: Results of a Native Single Serum Sample External Quality Assessment Program for Cobalamin, Folate, Ferritin, Thyroid-Stimulating Hormone, and Free T4 Analyses.

    Science.gov (United States)

    Kristensen, Gunn B B; Rustad, Pål; Berg, Jens P; Aakre, Kristin M

    2016-09-01

    We undertook this study to evaluate method differences for 5 components analyzed by immunoassays, to explore whether the use of method-dependent reference intervals may compensate for method differences, and to investigate commutability of external quality assessment (EQA) materials. Twenty fresh native single serum samples, a fresh native serum pool, Nordic Federation of Clinical Chemistry Reference Serum X (serum X) (serum pool), and 2 EQA materials were sent to 38 laboratories for measurement of cobalamin, folate, ferritin, free T4, and thyroid-stimulating hormone (TSH) by 5 different measurement procedures [Roche Cobas (n = 15), Roche Modular (n = 4), Abbott Architect (n = 8), Beckman Coulter Unicel (n = 2), and Siemens ADVIA Centaur (n = 9)]. The target value for each component was calculated based on the mean of method means or measured by a reference measurement procedure (free T4). Quality specifications were based on biological variation. Local reference intervals were reported from all laboratories. Method differences that exceeded acceptable bias were found for all components except folate. Free T4 differences from the uncommonly used reference measurement procedure were large. Reference intervals differed between measurement procedures but also within 1 measurement procedure. The serum X material was commutable for all components and measurement procedures, whereas the EQA materials were noncommutable in 13 of 50 occasions (5 components, 5 methods, 2 EQA materials). The bias between the measurement procedures was unacceptably large in 4/5 tested components. Traceability to reference materials as claimed by the manufacturers did not lead to acceptable harmonization. Adjustment of reference intervals in accordance with method differences and use of commutable EQA samples are not implemented commonly. © 2016 American Association for Clinical Chemistry.

  11. Medical journal peer review: process and bias.

    Science.gov (United States)

    Manchikanti, Laxmaiah; Kaye, Alan D; Boswell, Mark V; Hirsch, Joshua A

    2015-01-01

    Scientific peer review is pivotal in health care research in that it facilitates the evaluation of findings for competence, significance, and originality by qualified experts. While the origins of peer review can be traced to the societies of the eighteenth century, it became an institutionalized part of the scholarly process in the latter half of the twentieth century. This was a response to the growth of research and greater subject specialization. With the current increase in the number of specialty journals, the peer review process continues to evolve to meet the needs of patients, clinicians, and policy makers. The peer review process itself faces challenges. Unblinded peer review might suffer from positive or negative bias towards certain authors, specialties, and institutions. Peer review can also suffer when editors and/or reviewers might be unable to understand the contents of the submitted manuscript. This can result in an inability to detect major flaws, or revelations of major flaws after acceptance of publication by the editors. Other concerns include potentially long delays in publication and challenges uncovering plagiarism, duplication, corruption and scientific misconduct. Conversely, a multitude of these challenges have led to claims of scientific misconduct and an erosion of faith. These challenges have invited criticism of the peer review process itself. However, despite its imperfections, the peer review process enjoys widespread support in the scientific community. Peer review bias is one of the major focuses of today's scientific assessment of the literature. Various types of peer review bias include content-based bias, confirmation bias, bias due to conservatism, bias against interdisciplinary research, publication bias, and the bias of conflicts of interest. Consequently, peer review would benefit from various changes and improvements with appropriate training of reviewers to provide quality reviews to maintain the quality and integrity of

  12. A meta-analysis of gender stereotypes and bias in experimental simulations of employment decision making.

    Science.gov (United States)

    Koch, Amanda J; D'Mello, Susan D; Sackett, Paul R

    2015-01-01

    Gender bias continues to be a concern in many work settings, leading researchers to identify factors that influence workplace decisions. In this study we examine several of these factors, using an organizing framework of sex distribution within jobs (including male- and female-dominated jobs as well as sex-balanced, or integrated, jobs). We conducted random effects meta-analyses including 136 independent effect sizes from experimental studies (N = 22,348) and examined the effects of decision-maker gender, amount and content of information available to the decision maker, type of evaluation, and motivation to make careful decisions on gender bias in organizational decisions. We also examined study characteristics such as type of participant, publication year, and study design. Our findings revealed that men were preferred for male-dominated jobs (i.e., gender-role congruity bias), whereas no strong preference for either gender was found for female-dominated or integrated jobs. Second, male raters exhibited greater gender-role congruity bias than did female raters for male-dominated jobs. Third, gender-role congruity bias did not consistently decrease when decision makers were provided with additional information about those they were rating, but gender-role congruity bias was reduced when information clearly indicated high competence of those being evaluated. Fourth, gender-role congruity bias did not differ between decisions that required comparisons among ratees and decisions made about individual ratees. Fifth, decision makers who were motivated to make careful decisions tended to exhibit less gender-role congruity bias for male-dominated jobs. Finally, for male-dominated jobs, experienced professionals showed smaller gender-role congruity bias than did undergraduates or working adults.

  13. Self-Consciousness and Bias in Social Interaction.

    Science.gov (United States)

    Sandelands, Lloyd E.; Stablein, Ralph E.

    1986-01-01

    Investigated whether trait differences in self-consciousness would account for egocentric attribution bias in social interaction. Bias was greater for high public self-consciousness. Public self-consciousness had no effect in the Interaction Unimportant Condition where social interaction was not salient. Contrary to prediction, however, the…

  14. Multiple Imputation for Network Analyses

    NARCIS (Netherlands)

    Krause, Robert; Huisman, Mark; Steglich, Christian; Snijders, Thomas

    2016-01-01

    Missing data on network ties is a fundamental problem for network analyses. The biases induced by missing edge data, even when missing completely at random (MCAR), are widely acknowledged and problematic for network analyses (Kossinets, 2006; Huisman & Steglich, 2008; Huisman, 2009). Although model-

  15. CPI Bias in Korea

    Directory of Open Access Journals (Sweden)

    Chul Chung

    2007-12-01

    Full Text Available We estimate the CPI bias in Korea by employing the approach of Engel’s Law as suggested by Hamilton (2001. This paper is the first attempt to estimate the bias using Korean panel data, Korean Labor and Income Panel Study(KLIPS. Following Hamilton’s model with non­linear specification correction, our estimation result shows that the cumulative CPI bias over the sample period (2000-2005 was 0.7 percent annually. This CPI bias implies that about 21 percent of the inflation rate during the period can be attributed to the bias. In light of purchasing power parity, we provide an interpretation of the estimated bias.

  16. On commercial media bias

    OpenAIRE

    Germano, Fabrizio

    2008-01-01

    Within the spokes model of Chen and Riordan (2007) that allows for non-localized competition among arbitrary numbers of media outlets, we quantify the effect of concentration of ownership on quality and bias of media content. A main result shows that too few commercial outlets, or better, too few separate owners of commercial outlets can lead to substantial bias in equilibrium. Increasing the number of outlets (commercial and non-commercial) tends to bring down this bias; but the strongest ef...

  17. Conducting Meta-Analyses Based on p Values

    Science.gov (United States)

    van Aert, Robbie C. M.; Wicherts, Jelte M.; van Assen, Marcel A. L. M.

    2016-01-01

    Because of overwhelming evidence of publication bias in psychology, techniques to correct meta-analytic estimates for such bias are greatly needed. The methodology on which the p-uniform and p-curve methods are based has great promise for providing accurate meta-analytic estimates in the presence of publication bias. However, in this article, we show that in some situations, p-curve behaves erratically, whereas p-uniform may yield implausible estimates of negative effect size. Moreover, we show that (and explain why) p-curve and p-uniform result in overestimation of effect size under moderate-to-large heterogeneity and may yield unpredictable bias when researchers employ p-hacking. We offer hands-on recommendations on applying and interpreting results of meta-analyses in general and p-uniform and p-curve in particular. Both methods as well as traditional methods are applied to a meta-analysis on the effect of weight on judgments of importance. We offer guidance for applying p-uniform or p-curve using R and a user-friendly web application for applying p-uniform. PMID:27694466

  18. Things I Have Learned about Meta-Analysis Since 1990: Reducing Bias in Search of “The Big Picture” / Ce que j’ai appris sur la méta-analyse depuis 1990 : réduire les partis pris en quête d’une vue d’ensemble

    Directory of Open Access Journals (Sweden)

    Robert M Bernard

    2014-12-01

    Full Text Available This paper examines sources of potential bias in systematic reviews and meta-analyses which can distort their findings, leading to problems with interpretation and application by practitioners and policymakers. It follows from an article that was published in the Canadian Journal of Communication in 1990, “Integrating Research into Instructional Practice: The Use and Abuse of Meta-analysis,” which introduced meta-analysis as a means for estimating population parameters and summarizing quantitative research around instructional research questions. This paper begins by examining two cases where multiple meta-analyses disagree. It then goes on to describe substantive and methodological aspects of meta-analysis where various kinds of bias can influence the outcomes and suggests measures that can be taken to avoid them. The intention is to improve the reliability and accuracy of reviews so that practitioners can trust the results and use them more effectively. Cet article examine les sources des partis pris potentiels dans les synthèses systématiques et les méta-analyses qui peuvent déformer les conclusions, ce qui peut causer des problèmes d’interprétation et d’application par les praticiens et les responsables des politiques. Il fait suite à un article publié dans le Canadian Journal of Communication en 1990, intitulé « Integrating Research into Instructional Practice: The Use and Abuse of Meta-analysis », qui présentait la méta-analyse comme moyen d’estimer les paramètres relatifs à la population et de résumer la recherche quantitative sur les questions de recherche pédagogique. L’article commence avec l’examen de deux cas dans lesquels de nombreuses méta-analyses sont en désaccord. Il décrit ensuite les aspects substantifs et méthodologiques des méta-analyses dans lesquels divers types de partis pris peuvent influencer les résultats et suggère des mesures qui peuvent être adoptées pour éviter ces partis

  19. The Effectiveness of Cognitive Bias Modification Interventions for Substance Addictions: A Meta-Analysis

    Science.gov (United States)

    Kok, Robin N.; Cuijpers, Pim

    2016-01-01

    Background and Aims Cognitive bias modification (CBM) interventions, presumably targeting automatic processes, are considered particularly promising for addictions. We conducted a meta-analysis examining randomized controlled trials (RCTs) of CBM for substance addiction outcomes. Methods Studies were identified through systematic searches in bibliographical databases. We included RCTs of CBM interventions, alone or in combination with other treatments, for any type of addiction. We examined trial risk of bias, publication bias and possible moderators. Effects sizes were computed for post-test and follow-up, using a random-effects model. We grouped outcome measures and reported results for addiction (all related measures), craving and cognitive bias. Results We identified 25 trials, 18 for alcohol problems, and 7 for smoking. At post-test, there was no significant effect of CBM for addiction, g = 0.08 (95% CI -0.02 to 0.18) or craving, g = 0.05 (95% CI -0.06 to 0.16), but there was a significant, moderate effect on cognitive bias, g = 0.60 (95% CI 0.39 to 0.79). Results were similar for alcohol and smoking outcomes taken separately. Follow-up addiction outcomes were reported in 7 trials, resulting in a small but significant effect of CBM, g = 0.18 (95% CI 0.03 to 0.32). Results for addiction and craving did not differ by substance type, sample type, delivery setting, bias targeted or number of sessions. Risk of bias was high or uncertain in most trials, for most criteria considered. Meta-regression analyses revealed significant inverse relationships between risk of bias and effect sizes for addiction outcomes and craving. The relationship between cognitive bias and respectively addiction ESs was not significant. There was consistent evidence of publication bias in the form of funnel plot asymmetry. Conclusions Our results cast serious doubts on the clinical utility of CBM interventions for addiction problems, but sounder methodological trials are necessary before

  20. Is healthcare a 'Necessity' or 'Luxury'? an empirical evidence from public and private sector analyses of South-East Asian countries?

    Science.gov (United States)

    Khan, Jahangir Am; Mahumud, Rashidul Alam

    2015-01-01

    South-East Asian Regional (SEAR) countries range from low- to middle-income countries and have considerable differences in mix of public and private sector expenditure on health. This study intends to estimate the income-elasticities of healthcare expenditure in public and private sectors separately for investigating whether healthcare is a 'necessity' or 'luxury' for citizens of these countries. Panel data from 9 SEAR countries over 16 years (1995-2010) were employed. Fixed- and random-effect models were fitted to estimate income-elasticity of public, private and total healthcare expenditure. Results showed that one percent point increase in GDP per capita increased private expenditure on healthcare by 1.128%, while public expenditure increased by only 0.412%. Inclusion of three-year lagged variables of GDP per capita in the models did not have remarkable influence on the findings. The citizens of SEAR countries consider healthcare as a necessity while provided through public sector and a luxury when delivered by private sector. By increasing the public provisions of healthcare, more redistribution of healthcare resources can be ensured, which can accelerate the journey of SEAR countries towards universal health coverage.

  1. Quantifying selective reporting and the Proteus phenomenon for multiple datasets with similar bias.

    Directory of Open Access Journals (Sweden)

    Thomas Pfeiffer

    Full Text Available Meta-analyses play an important role in synthesizing evidence from diverse studies and datasets that address similar questions. A major obstacle for meta-analyses arises from biases in reporting. In particular, it is speculated that findings which do not achieve formal statistical significance are less likely reported than statistically significant findings. Moreover, the patterns of bias can be complex and may also depend on the timing of the research results and their relationship with previously published work. In this paper, we present an approach that is specifically designed to analyze large-scale datasets on published results. Such datasets are currently emerging in diverse research fields, particularly in molecular medicine. We use our approach to investigate a dataset on Alzheimer's disease (AD that covers 1167 results from case-control studies on 102 genetic markers. We observe that initial studies on a genetic marker tend to be substantially more biased than subsequent replications. The chances for initial, statistically non-significant results to be published are estimated to be about 44% (95% CI, 32% to 63% relative to statistically significant results, while statistically non-significant replications have almost the same chance to be published as statistically significant replications (84%; 95% CI, 66% to 107%. Early replications tend to be biased against initial findings, an observation previously termed Proteus phenomenon: The chances for non-significant studies going in the same direction as the initial result are estimated to be lower than the chances for non-significant studies opposing the initial result (73%; 95% CI, 55% to 96%. Such dynamic patterns in bias are difficult to capture by conventional methods, where typically simple publication bias is assumed to operate. Our approach captures and corrects for complex dynamic patterns of bias, and thereby helps generating conclusions from published results that are more robust

  2. Political bias is tenacious.

    Science.gov (United States)

    Ditto, Peter H; Wojcik, Sean P; Chen, Eric Evan; Grady, Rebecca Hofstein; Ringel, Megan M

    2015-01-01

    Duarte et al. are right to worry about political bias in social psychology but they underestimate the ease of correcting it. Both liberals and conservatives show partisan bias that often worsens with cognitive sophistication. More non-liberals in social psychology is unlikely to speed our convergence upon the truth, although it may broaden the questions we ask and the data we collect.

  3. Biases in categorization

    NARCIS (Netherlands)

    Das-Smaal, E.A.

    1990-01-01

    On what grounds can we conclude that an act of categorization is biased? In this chapter, it is contended that in the absence of objective norms of what categories actually are, biases in categorization can only be specified in relation to theoretical understandings of categorization. Therefore, the

  4. The Maturation of Public Relations Degree Programs--Ten Years in Retrospect: Struggles, Experiences and Analyses of a Communication-Based PR Program.

    Science.gov (United States)

    Hall, G. Jon; Edwards, Pamela Jones

    This paper reviews the historical experience of a new public relations program housed in a speech communication department (rather than in a journalism department, which is traditional), discusses some of the internal and external struggles experienced in the implementation and administration of the program, and reports on the placement of its…

  5. Cognitive sophistication does not attenuate the bias blind spot.

    Science.gov (United States)

    West, Richard F; Meserve, Russell J; Stanovich, Keith E

    2012-09-01

    The so-called bias blind spot arises when people report that thinking biases are more prevalent in others than in themselves. Bias turns out to be relatively easy to recognize in the behaviors of others, but often difficult to detect in one's own judgments. Most previous research on the bias blind spot has focused on bias in the social domain. In 2 studies, we found replicable bias blind spots with respect to many of the classic cognitive biases studied in the heuristics and biases literature (e.g., Tversky & Kahneman, 1974). Further, we found that none of these bias blind spots were attenuated by measures of cognitive sophistication such as cognitive ability or thinking dispositions related to bias. If anything, a larger bias blind spot was associated with higher cognitive ability. Additional analyses indicated that being free of the bias blind spot does not help a person avoid the actual classic cognitive biases. We discuss these findings in terms of a generic dual-process theory of cognition.

  6. Using Critical Thinking to Identify Bias in the News Media: The Art of Critical Analysis.

    Science.gov (United States)

    Paul, Richard W.; Adamson, Kenneth R.

    1990-01-01

    Urges social studies teachers to help students understand and identify sociocentric, national bias in the news media. Illustrates how the media fosters "us versus them" thinking and how word choice often reflects bias. Outlines activities to help students recognize bias. Provides weak and strong examples of students' analyses of bias in news…

  7. 互联网舆情搜索分析系统的设计与实现%Design and Implementation of an Internet Public Sentiment Searching and Analysing System

    Institute of Scientific and Technical Information of China (English)

    袁键; 田宏林; 张涛

    2012-01-01

    文章描述了一个互联网舆情搜索分析系统的设计及实现方法.系统采用互联网搜索引擎(例如谷歌、百度、雅虎等)、RSS技术、网页信息结构化抽取等技术实现了对互联网敏感信息发现以及网络舆情信息的搜索分析.%In this paper, design and implementation method for an Internet public sentiment searching and analysing system is depicted. By using Internet Search Engines(such as Google, Baidu. Yahoo and so on), technologies of RSS and Web information extraction, this system is built to search Internet sensitive information and analyse the Internet public sentiment.

  8. Media Bias and Reputation

    OpenAIRE

    Matthew Gentzkow; Jesse M. Shapiro

    2005-01-01

    A Bayesian consumer who is uncertain about the quality of an information source will infer that the source is of higher quality when its reports conform to the consumer's prior expectations. We use this fact to build a model of media bias in which firms slant their reports toward the prior beliefs of their customers in order to build a reputation for quality. Bias emerges in our model even though it can make all market participants worse off. The model predicts that bias will be less severe w...

  9. Biased predecision processing.

    Science.gov (United States)

    Brownstein, Aaron L

    2003-07-01

    Decision makers conduct biased predecision processing when they restructure their mental representation of the decision environment to favor one alternative before making their choice. The question of whether biased predecision processing occurs has been controversial since L. Festinger (1957) maintained that it does not occur. The author reviews relevant research in sections on theories of cognitive dissonance, decision conflict, choice certainty, action control, action phases, dominance structuring, differentiation and consolidation, constructive processing, motivated reasoning, and groupthink. Some studies did not find evidence of biased predecision processing, but many did. In the Discussion section, the moderators are summarized and used to assess the theories.

  10. Modeling confirmation bias and polarization

    CERN Document Server

    Del Vicario, Michela; Caldarelli, Guido; Stanley, H Eugene; Quattrociocchi, Walter

    2016-01-01

    Online users tend to select claims that adhere to their system of beliefs and to ignore dissenting information. Confirmation bias, indeed, plays a pivotal role in viral phenomena. Furthermore, the wide availability of content on the web fosters the aggregation of likeminded people where debates tend to enforce group polarization. Such a configuration might alter the public debate and thus the formation of the public opinion. In this paper we provide a mathematical model to study online social debates and the related polarization dynamics. We assume the basic updating rule of the Bounded Confidence Model (BCM) and we develop two variations a) the Rewire with Bounded Confidence Model (RBCM), in which discordant links are broken until convergence is reached; and b) the Unbounded Confidence Model, under which the interaction among discordant pairs of users is allowed even with a negative feedback, either with the rewiring step (RUCM) or without it (UCM). From numerical simulations we find that the new models (UCM...

  11. Value of Sample Return and High Precision Analyses: Need for A Resource of Compelling Stories, Metaphors and Examples for Public Speakers

    Science.gov (United States)

    Allton, J. H.

    2017-01-01

    There is widespread agreement among planetary scientists that much of what we know about the workings of the solar system comes from accurate, high precision measurements on returned samples. Precision is a function of the number of atoms the instrumentation is able to count. Accuracy depends on the calibration or standardization technique. For Genesis, the solar wind sample return mission, acquiring enough atoms to ensure precise SW measurements and then accurately quantifying those measurements were steps known to be non-trivial pre-flight. The difficulty of precise and accurate measurements on returned samples, and why they cannot be made remotely, is not communicated well to the public. In part, this is be-cause "high precision" is abstract and error bars are not very exciting topics. This paper explores ideas for collecting and compiling compelling metaphors and colorful examples as a resource for planetary science public speakers.

  12. Analyses on the Errors in C-E Translation of Public Signs in Scenic Spot —Taking Taimu Mountain as an Example

    Institute of Scientific and Technical Information of China (English)

    傅钰钊

    2016-01-01

    With the establishment of a new free trade area in Fujian Province, various popular tourist sights in Ningde city are expected to receive more foreign visitors than ever before, as a consequence, the English version of public signs placed throughout all the spots has turn into an indispensable role of the endeavor to ensure the satisfaction of their leisure journeys. According to these, it's urgent to conduct research on the C-E translation of public signs in scenic spots. Mistakes are found during the personal survey of Taimu Mountain, the paper gathers and corrects these misleading descriptions with care and puts forward suggestions to the relevant authorities with the best intention of improving the cultural environment and further promote its status in the world tourism industry.

  13. Kvalitative analyser ..

    DEFF Research Database (Denmark)

    Boolsen, Merete Watt

    bogen forklarer de fundamentale trin i forskningsprocessen og applikerer dem på udvalgte kvalitative analyser: indholdsanalyse, Grounded Theory, argumentationsanalyse og diskursanalyse......bogen forklarer de fundamentale trin i forskningsprocessen og applikerer dem på udvalgte kvalitative analyser: indholdsanalyse, Grounded Theory, argumentationsanalyse og diskursanalyse...

  14. Berkson’s bias, selection bias, and missing data

    OpenAIRE

    Westreich, Daniel

    2012-01-01

    While Berkson’s bias is widely recognized in the epidemiologic literature, it remains underappreciated as a model of both selection bias and bias due to missing data. Simple causal diagrams and 2×2 tables illustrate how Berkson’s bias connects to collider bias and selection bias more generally, and show the strong analogies between Berksonian selection bias and bias due to missing data. In some situations, considerations of whether data are missing at random or missing not at random is less i...

  15. Introduction to Unconscious Bias

    Science.gov (United States)

    Schmelz, Joan T.

    2010-05-01

    We all have biases, and we are (for the most part) unaware of them. In general, men and women BOTH unconsciously devalue the contributions of women. This can have a detrimental effect on grant proposals, job applications, and performance reviews. Sociology is way ahead of astronomy in these studies. When evaluating identical application packages, male and female University psychology professors preferred 2:1 to hire "Brian” over "Karen” as an assistant professor. When evaluating a more experienced record (at the point of promotion to tenure), reservations were expressed four times more often when the name was female. This unconscious bias has a repeated negative effect on Karen's career. This talk will introduce the concept of unconscious bias and also give recommendations on how to address it using an example for a faculty search committee. The process of eliminating unconscious bias begins with awareness, then moves to policy and practice, and ends with accountability.

  16. Economic Costs of Bias-Based Bullying

    Science.gov (United States)

    Baams, Laura; Talmage, Craig A.; Russell, Stephen T.

    2017-01-01

    Because many school districts receive funding based on student attendance, absenteeism results in a high cost for the public education system. This study shows the direct links between bias-based bullying, school absenteeism because of feeling unsafe at school, and loss of funds for school districts in California. Data from the 2011-2013…

  17. Increasingly minimal bias routing

    Energy Technology Data Exchange (ETDEWEB)

    Bataineh, Abdulla; Court, Thomas; Roweth, Duncan

    2017-02-21

    A system and algorithm configured to generate diversity at the traffic source so that packets are uniformly distributed over all of the available paths, but to increase the likelihood of taking a minimal path with each hop the packet takes. This is achieved by configuring routing biases so as to prefer non-minimal paths at the injection point, but increasingly prefer minimal paths as the packet proceeds, referred to herein as Increasing Minimal Bias (IMB).

  18. Biased causal inseparable game

    CERN Document Server

    Bhattacharya, Some Sankar

    2015-01-01

    Here we study the \\emph{causal inseparable} game introduced in [\\href{http://www.nature.com/ncomms/journal/v3/n10/full/ncomms2076.html}{Nat. Commun. {\\bf3}, 1092 (2012)}], but it's biased version. Two separated parties, Alice and Bob, generate biased bits (say input bit) in their respective local laboratories. Bob generates another biased bit (say decision bit) which determines their goal: whether Alice has to guess Bob's bit or vice-verse. Under the assumption that events are ordered with respect to some global causal relation, we show that the success probability of this biased causal game is upper bounded, giving rise to \\emph{biased causal inequality} (BCI). In the \\emph{process matrix} formalism, which is locally in agreement with quantum physics but assume no global causal order, we show that there exist \\emph{inseparable} process matrices that violate the BCI for arbitrary bias in the decision bit. In such scenario we also derive the maximal violation of the BCI under local operations involving tracele...

  19. Managing Public Accountability : How Public Managers Manage Public Accountability

    NARCIS (Netherlands)

    Schillemans, Thomas

    2015-01-01

    Accountability is of growing importance in contemporary governance. The academic literature on public accountability is fraught with concerned analyses, suggesting that accountability is a problematic issue for public managers. This article investigates how public managers experience accountability

  20. Large scale gene expression meta-analysis reveals tissue-specific, sex-biased gene expression in humans

    Directory of Open Access Journals (Sweden)

    Benjamin Mayne

    2016-10-01

    Full Text Available The severity and prevalence of many diseases are known to differ between the sexes. Organ specific sex-biased gene expression may underpin these and other sexually dimorphic traits. To further our understanding of sex differences in transcriptional regulation, we performed meta-analyses of sex biased gene expression in multiple human tissues. We analysed 22 publicly available human gene expression microarray data sets including over 2500 samples from 15 different tissues and 9 different organs. Briefly, by using an inverse-variance method we determined the effect size difference of gene expression between males and females. We found the greatest sex differences in gene expression in the brain, specifically in the anterior cingulate cortex, (1818 genes, followed by the heart (375 genes, kidney (224 genes, colon (218 genes and thyroid (163 genes. More interestingly, we found different parts of the brain with varying numbers and identity of sex-biased genes, indicating that specific cortical regions may influence sexually dimorphic traits. The majority of sex-biased genes in other tissues such as the bladder, liver, lungs and pancreas were on the sex chromosomes or involved in sex hormone production. On average in each tissue, 32% of autosomal genes that were expressed in a sex-biased fashion contained androgen or estrogen hormone response elements. Interestingly, across all tissues, we found approximately two-thirds of autosomal genes that were sex-biased were not under direct influence of sex hormones. To our knowledge this is the largest analysis of sex-biased gene expression in human tissues to date. We identified many sex-biased genes that were not under the direct influence of sex chromosome genes or sex hormones. These may provide targets for future development of sex-specific treatments for diseases.

  1. Hindsight bias and outcome bias in the social construction of medical negligence: a review.

    Science.gov (United States)

    Hugh, Thomas B; Dekker, Sidney W A

    2009-05-01

    Medical negligence has been the subject of much public debate in recent decades. Although the steep increase in the frequency and size of claims against doctors at the end of the last century appears to have plateaued, in Australia at least, medical indemnity costs and consequences are still a matter of concern for doctors, medical defence organisations and governments in most developed countries. Imprecision in the legal definition of negligence opens the possibility that judgments of this issue at several levels may be subject to hindsight and outcome bias. Hindsight bias relates to the probability of an adverse event perceived by a retrospective observer ("I would have known it was going to happen"), while outcome bias is a largely subconscious cognitive distortion produced by the observer's knowledge of the adverse outcome. This review examines the relevant legal, medical, psychological and sociological literature on the operation of these pervasive and universal biases in the retrospective evaluation of adverse events. A finding of medical negligence is essentially an after-the-event social construction and is invariably affected by hindsight bias and knowledge of the adverse outcome. Such biases obviously pose a threat to the fairness of judgments. A number of debiasing strategies have been suggested but are relatively ineffective because of the universality and strength of these biases and the inherent difficulty of concealing from expert witnesses knowledge of the outcome. Education about the effect of the biases is therefore important for lawyers, medical expert witnesses and the judiciary.

  2. Genomic and expression analyses of Tursiops truncatus T cell receptor gamma (TRG) and alpha/delta (TRA/TRD) loci reveal a similar basic public γδ repertoire in dolphin and human.

    Science.gov (United States)

    Linguiti, Giovanna; Antonacci, Rachele; Tasco, Gianluca; Grande, Francesco; Casadio, Rita; Massari, Serafina; Castelli, Vito; Consiglio, Arianna; Lefranc, Marie-Paule; Ciccarese, Salvatrice

    2016-08-15

    The bottlenose dolphin (Tursiops truncatus) is a mammal that belongs to the Cetartiodactyla and have lived in marine ecosystems for nearly 60 millions years. Despite its popularity, our knowledge about its adaptive immunity and evolution is very limited. Furthermore, nothing is known about the genomics and evolution of dolphin antigen receptor immunity. Here we report a evolutionary and expression study of Tursiops truncatus T cell receptor gamma (TRG) and alpha/delta (TRA/TRD) genes. We have identified in silico the TRG and TRA/TRD genes and analyzed the relevant mature transcripts in blood and in skin from four subjects. The dolphin TRG locus is the smallest and simplest of all mammalian loci as yet studied. It shows a genomic organization comprising two variable (V1 and V2), three joining (J1, J2 and J3) and a single constant (C), genes. Despite the fragmented nature of the genome assemblies, we deduced the TRA/TRD locus organization, with the recent TRDV1 subgroup genes duplications, as it is expected in artiodactyls. Expression analysis from blood of a subject allowed us to assign unambiguously eight TRAV genes to those annotated in the genomic sequence and to twelve new genes, belonging to five different subgroups. All transcripts were productive and no relevant biases towards TRAV-J rearrangements are observed. Blood and skin from four unrelated subjects expression data provide evidence for an unusual ratio of productive/unproductive transcripts which arise from the TRG V-J gene rearrangement and for a "public" gamma delta TR repertoire. The productive cDNA sequences, shared both in the same and in different individuals, include biases of the TRGV1 and TRGJ2 genes. The high frequency of TRGV1-J2/TRDV1- D1-J4 productive rearrangements in dolphins may represent an interesting oligo-clonal population comparable to that found in human with the TRGV9- JP/TRDV2-D-J T cells and in primates. Although the features of the TRG and TRA/TRD loci organization reflect

  3. Bias in emerging biomarkers for bipolar disorder

    DEFF Research Database (Denmark)

    Carvalho, A F; Köhler, C A; Fernandes, B S

    2016-01-01

    BACKGROUND: To date no comprehensive evaluation has appraised the likelihood of bias or the strength of the evidence of peripheral biomarkers for bipolar disorder (BD). Here we performed an umbrella review of meta-analyses of peripheral non-genetic biomarkers for BD. METHOD: The Pubmed/Medline, E...

  4. Counterfeits and imitations of Viagra and Cialis tablets: trends and risks to public health - A survey of the analyses carried out at the Dutch National Institute for Public Health and the Environment in the time period 2000 - 2004

    NARCIS (Netherlands)

    Blok-Tip L; Vogelpoel H; Vredenbregt MJ; Barends DM; Kaste D de; KCF

    2005-01-01

    During the last years de Dutch market has been flooded with falsifications of Viagra. and Cialis.. Both products are used for the treatment of erectile dysfunction. This report is about the trend of these falsifications during the years 2000 - 2004. The risks of these products to public health are s

  5. Counterfeits and imitations of Viagra and Cialis tablets: trends and risks to public health - A survey of the analyses carried out at the Dutch National Institute for Public Health and the Environment in the time period 2000 - 2004

    NARCIS (Netherlands)

    Blok-Tip L; Vogelpoel H; Vredenbregt MJ; Barends DM; Kaste D de; KCF

    2005-01-01

    During the last years de Dutch market has been flooded with falsifications of Viagra. and Cialis.. Both products are used for the treatment of erectile dysfunction. This report is about the trend of these falsifications during the years 2000 - 2004. The risks of these products to public health are s

  6. Behavioral Biases of Individual Investors: The Effect of Anchoring

    Directory of Open Access Journals (Sweden)

    Salma Zaiane

    2015-03-01

    Full Text Available The objective of this paper is to investigate the presence of the anchoring bias in the financial decision making of individual investors. A survey study is carried out to find out how the studied bias affects the investment behavior on the Tunisian stock market. The survey is for exploratory purpose and it is based on multiple factorial correspondence analyses. The results reveal that Tunisian investors do not suffer from the anchoring bias.

  7. Gender Bias in Testing: Current Debates for Future Priorities. A Public Policy Dialogue. Proceedings of the Ford Foundation Women's Program Forum (2nd, New York, New York, April 1989).

    Science.gov (United States)

    Rosser, Phyllis; And Others

    In April 1989, the Women's Program Forum of the Ford Foundation sponsored a seminar that examined the current debates and future directions surrounding the issue of gender bias in testing, with particular attention to the Scholastic Aptitude Test (SAT). This booklet provides a transcript of the proceedings of the forum. P. Rosser's presentation of…

  8. Measuring Agricultural Bias

    DEFF Research Database (Denmark)

    Jensen, Henning Tarp; Robinson, Sherman; Tarp, Finn

    . For the 15 sample countries, the results indicate that the agricultural price incentive bias, which was generally perceived to exist during the 1980s, was largely eliminated during the 1990s. The results also demonstrate that general equilibrium effects and country-specific characteristics - including trade...... shares and intersectoral linkages - are crucial for determining the sign and magnitude of trade policy bias. The GE-ERP measure is therefore uniquely suited to capture the full impact of trade policies on agricultural price incentives. A Monte Carlo procedure confirms that the results are robust...

  9. Measuring agricultural policy bias

    DEFF Research Database (Denmark)

    Jensen, Henning Tarp; Robinson, Sherman; Tarp, Finn

    2010-01-01

    Measurement is a key issue in the literature on price incentive bias induced by trade policy. We introduce a general equilibrium measure of the relative effective rate of protection, which generalizes earlier protection measures. For our fifteen sample countries, results indicate that the agricul......Measurement is a key issue in the literature on price incentive bias induced by trade policy. We introduce a general equilibrium measure of the relative effective rate of protection, which generalizes earlier protection measures. For our fifteen sample countries, results indicate...... protection measure is therefore uniquely suited to capture the full impact of trade policies on relative agricultural price incentives....

  10. Awareness and minimisation of systematic bias in research.

    LENUS (Irish Health Repository)

    Malone, Helen

    2014-03-01

    A major goal of nursing and midwifery is the delivery of evidence-based practice. Consequently, it is essential for the quality and safety of patient\\/client care that policy makers, educators and practitioners are aware of the presence of potential systematic bias in research practice and research publications so that only sound evidence translates into practice. The main aim of this paper is to highlight the need for ongoing awareness of the potential presence of systematic bias in research practice, to explore commonly reported types of systematic bias and to report some methods that can be applied to minimise systematic bias in research.

  11. Understanding antigay bias from a cognitive-affective-behavioral perspective.

    Science.gov (United States)

    Callender, Kevin A

    2015-01-01

    In general, United States citizens have become increasingly more accepting of lesbians and gay men over the past few decades. Despite this shift in public attitudes, antigay bias remains openly tolerated, accepted, practiced, and even defended by a substantial portion of the population. This article reviews why and how antigay bias persists using a cognitive-affective-behavioral perspective that touches on sociocognitive factors such as prejudice and stereotyping, as well as features unique to antigay bias, such as its concealable nature. The article concludes with a discussion of how understanding modern antigay bias through a cognitive-affective-behavioral lens can be applied to reduce discrimination against gays and lesbians.

  12. Critical Analyses of the Introduction of Liquid-Based Cytology in a Public Health Service of the State of São Paulo, Brazil.

    Science.gov (United States)

    Longatto-Filho, Adhemar; Levi, José Eduardo; Martins, Toni Ricardo; Cohen, Diane; Cury, Lise; Villa, Luisa Lina; Eluf-Neto, José

    2015-01-01

    The aim of this study was to compare the performance of the current conventional Pap smear with liquid-based cytology (LBC) preparations. Women routinely undergoing their cytopathological and histopathological examinations at Fundação Oncocentro de São Paulo (FOSP) were recruited for LBC. Conventional smears were analyzed from women from other areas of the State of São Paulo with similar sociodemographic characteristics. A total of 218,594 cases were analyzed, consisting of 206,999 conventional smears and 11,595 LBC. Among the conventional smears, 3.0% were of unsatisfactory preparation; conversely, unsatisfactory LBC preparations accounted for 0.3%. The ASC-H (atypical squamous cells - cannot exclude high-grade squamous intraepithelial lesion) frequency did not demonstrate any differences between the two methods. In contrast, the incidence of ASC-US (atypical squamous cells of undetermined significance) was almost twice as frequent between LBC and conventional smears, at 2.9 versus 1.6%, respectively. An equal percentage of high-grade squamous intraepithelial lesions were observed for the two methods, but not for low-grade squamous intraepithelial lesions, which were more significantly observed in LBC preparations than in conventional smears (2.2 vs. 0.7%). The index of positivity was importantly enhanced from 3.0% (conventional smears) to 5.7% (LBC). LBC performed better than conventional smears, and we are truly confident that LBC can improve public health strategies aimed at reducing cervical lesions through prevention programs. © 2015 S. Karger AG, Basel.

  13. Simulating currency substitution bias

    NARCIS (Netherlands)

    M. Boon (Martin); C.J.M. Kool (Clemens); C.G. de Vries (Casper)

    1989-01-01

    textabstractThe sign and size of estimates of the elasticity of currency substitution critically depend on the definition of the oppurtunity costs of holding money. We investigate possible biases by means of Monte Carlo experiments, as sufficient real data are not available.

  14. Sex Bias in Children.

    Science.gov (United States)

    Zalk, Sue Rosenberg; And Others

    This study investigated children's sex biased attitudes as a function of the sex, age, and race of the child as well as a geographical-SES factor. Two attitudes were measured on a 55-item questionnaire: Sex Pride (attributing positive characteristics to a child of the same sex) and Sex Prejudice (attributing negative characteristics to a child of…

  15. Three Analyses on Legislation of Public-Private Partnership%政府和社会资本合作立法三论

    Institute of Scientific and Technical Information of China (English)

    黄娟

    2016-01-01

    Recently,Ministry of Finance has drawn up Public-Private Partnership Law of People’s Republic of China(draft for comment)to regulate the operation of PPP programs sys-tematically.Combining with existing practice of the PPP,We find that the following three aspects must be clarified in the PPP legislation:firstly,eliminating the difference on definition between PPP and franchise,and defining that franchise is a maj or form of PPP in the PPP legislation;Sec-ondly,clarifying access rules of different PPP programs in the PPP legislation to realize the coor-dination and connection between the PPP legislation and relating laws;Thirdly,by means of es-tablishing enterprise credit system,disposing of new-type exemplary measures,building mecha-nism of breach of contract,strengthening regulations in process and afterwards,in order to propel the PPP development effectively.%财政部新近起草了《中华人民共和国政府和社会资本合作法(征求意见稿)》,意在将PPP项目的运作加以统一规范。结合已有的 PPP 实践来看,PPP 统一立法应注意明确以下三方面内容:一是在立法中消除PPP与特许经营内涵界定上的分歧,明确特许经营是 PPP 的一种主要形式;二是在立法中明确不同类型的PPP项目的准入规则,实现 PPP 立法与相关法律之间的协调与衔接;三是通过企业诚信体系的建立、新型惩戒手段的配置、违约追究机制的确立等措施加强事中事后监管,助推PPP的有效开展。

  16. Analyses on public hospital performance appraisal and compensation management%公立医院绩效评价与薪酬管理初探

    Institute of Scientific and Technical Information of China (English)

    冯雨来; 陈晓红

    2011-01-01

    分析医院人力资源管理系统和医院运营改革中的关键内容,以对国内公立医院绩效评估及薪酬分配制度存在的问题进行分析,同时对医院的绩效评估及薪酬分配的一般实施路线进行了梳理,以供参考.结果显示,国内公立医院绩效评估及薪酬分配制度存在一些问题,如偏重功利性的绩效指标、偏重科研的绩效指标、薪酬分配制度标准陈旧、薪酬分配制度不够科学以及薪酬分配形式单一、缺少灵活的奖励措施等问题.研究表明,医院绩效与薪酬管理是医改的重要任务之一,已成为当代医院人力资源管理系统和医院运营改革中的关键内容,也是实现科学化管理医院的必然要求.%Key contents of hospital operation reform and hospital human resources management system are discussed to analyze problems in performance appraisal and compensation allocation system in public hospital in China. Process of implementing performance appraisal and compensation system is also analyzed. The results show that problems such as weighted to heavy on utility and research performance indictor, obsolescent, unscientific, humdrum and inflexible compensation allocation system are existed. Hospital performance and compensation allocation management is a key role of health system reform and a key content of hospital human resources management and operation reform. It is also a necessity demand for achieving modern and scientific management.

  17. Artificial bias typically neglected in comparisons of uncertain atmospheric data

    Science.gov (United States)

    Pitkänen, Mikko R. A.; Mikkonen, Santtu; Lehtinen, Kari E. J.; Lipponen, Antti; Arola, Antti

    2016-09-01

    Publications in atmospheric sciences typically neglect biases caused by regression dilution (bias of the ordinary least squares line fitting) and regression to the mean (RTM) in comparisons of uncertain data. We use synthetic observations mimicking real atmospheric data to demonstrate how the biases arise from random data uncertainties of measurements, model output, or satellite retrieval products. Further, we provide examples of typical methods of data comparisons that have a tendency to pronounce the biases. The results show, that data uncertainties can significantly bias data comparisons due to regression dilution and RTM, a fact that is known in statistics but disregarded in atmospheric sciences. Thus, we argue that often these biases are widely regarded as measurement or modeling errors, for instance, while they in fact are artificial. It is essential that atmospheric and geoscience communities become aware of and consider these features in research.

  18. Conflicts of interest in nutritional sciences: The forgotten bias in meta-analysis.

    Science.gov (United States)

    Lucas, Michel

    2015-12-26

    Awareness of conflicts of interest (COI) in medicine began in the 1980s. More recently, the problem has gained notoriety in nutritional sciences. COI with industry could bias study conclusions in the context of research activities and scientific publications on nutritional sciences. The issue of COI in nutritional sciences deserves more attention and requires careful analyses as biased information can negatively impact the development of dietary guidelines and, ultimately, population health. Decision-making is generally based on available, published evidence, but when the results are ambivalent, it is easier to opt for the status quo and ask for more studies. Readers might wonder if research is subsidized by industry as a counterbalancing strategy based on levels of evidence-only to slow down eminent positions and/or legislation on the food sector? How can this problem be overcome without producing paranoia and McCarthyism while trying to be as methodological as possible?

  19. Large Scale Gene Expression Meta-Analysis Reveals Tissue-Specific, Sex-Biased Gene Expression in Humans

    Science.gov (United States)

    Mayne, Benjamin T.; Bianco-Miotto, Tina; Buckberry, Sam; Breen, James; Clifton, Vicki; Shoubridge, Cheryl; Roberts, Claire T.

    2016-01-01

    The severity and prevalence of many diseases are known to differ between the sexes. Organ specific sex-biased gene expression may underpin these and other sexually dimorphic traits. To further our understanding of sex differences in transcriptional regulation, we performed meta-analyses of sex biased gene expression in multiple human tissues. We analyzed 22 publicly available human gene expression microarray data sets including over 2500 samples from 15 different tissues and 9 different organs. Briefly, by using an inverse-variance method we determined the effect size difference of gene expression between males and females. We found the greatest sex differences in gene expression in the brain, specifically in the anterior cingulate cortex, (1818 genes), followed by the heart (375 genes), kidney (224 genes), colon (218 genes), and thyroid (163 genes). More interestingly, we found different parts of the brain with varying numbers and identity of sex-biased genes, indicating that specific cortical regions may influence sexually dimorphic traits. The majority of sex-biased genes in other tissues such as the bladder, liver, lungs, and pancreas were on the sex chromosomes or involved in sex hormone production. On average in each tissue, 32% of autosomal genes that were expressed in a sex-biased fashion contained androgen or estrogen hormone response elements. Interestingly, across all tissues, we found approximately two-thirds of autosomal genes that were sex-biased were not under direct influence of sex hormones. To our knowledge this is the largest analysis of sex-biased gene expression in human tissues to date. We identified many sex-biased genes that were not under the direct influence of sex chromosome genes or sex hormones. These may provide targets for future development of sex-specific treatments for diseases.

  20. Confounding and bias in the attributable fraction.

    Science.gov (United States)

    Darrow, Lyndsey A; Steenland, N Kyle

    2011-01-01

    Inappropriate methods are frequently used to calculate the population attributable fraction (AF) for a given exposure of interest. This commonly occurs when authors use adjusted relative risks (RRs) reported in the literature (the "source" data), without access to the original data. In this analysis, we examine the relationship between the direction and magnitude of confounding in the source data and resulting bias in the attributable fraction when incorrect methods are used. We assess confounding by the confounding risk ratio, which is the ratio of the crude RR to the adjusted RR. We assess bias in the AF by the ratio of the incorrectly calculated AF to the correctly calculated AF. Using generated data, we examine the relationship between confounding and AF bias under various scenarios of population prevalence of exposure and strength of the exposure-disease association. For confounding risk ratios greater than 1.0 (ie, crude RR >adjusted RR), the AF is underestimated; for confounding risk ratios less than 1.0 (ie, crude RR confounding increases, and is dependent on the prevalence of exposure in the total population, with bias greatest at the lowest prevalence of exposure. Bias in the AF is also higher when the exposure-disease association is weaker. Results of these analyses can assist interpretation of incorrectly calculated attributable fraction estimates commonly reported in the epidemiologic literature.

  1. Temperature trend biases

    Science.gov (United States)

    Venema, Victor; Lindau, Ralf

    2016-04-01

    In an accompanying talk we show that well-homogenized national dataset warm more than temperatures from global collections averaged over the region of common coverage. In this poster we want to present auxiliary work about possible biases in the raw observations and on how well relative statistical homogenization can remove trend biases. There are several possible causes of cooling biases, which have not been studied much. Siting could be an important factor. Urban stations tend to move away from the centre to better locations. Many stations started inside of urban areas and are nowadays more outside. Even for villages the temperature difference between the centre and edge can be 0.5°C. When a city station moves to an airport, which often happened around WWII, this takes the station (largely) out of the urban heat island. During the 20th century the Stevenson screen was established as the dominant thermometer screen. This screen protected the thermometer much better against radiation than earlier designs. Deficits of earlier measurement methods have artificially warmed the temperatures in the 19th century. Newer studies suggest we may have underestimated the size of this bias. Currently we are in a transition to Automatic Weather Stations. The net global effect of this transition is not clear at this moment. Irrigation on average decreases the 2m-temperature by about 1 degree centigrade. At the same time, irrigation has increased significantly during the last century. People preferentially live in irrigated areas and weather stations serve agriculture. Thus it is possible that there is a higher likelihood that weather stations are erected in irrigated areas than elsewhere. In this case irrigation could lead to a spurious cooling trend. In the Parallel Observations Science Team of the International Surface Temperature Initiative (ISTI-POST) we are studying influence of the introduction of Stevenson screens and Automatic Weather Stations using parallel measurements

  2. Bias in collegiate courts

    OpenAIRE

    Olowofoyeku, AA

    2016-01-01

    This article addresses the issues attending common law collegiate courts’ engagements with allegations of bias within their own ranks. It will be argued that, in such cases, it would be inappropriate to involve the collegiate panel or any member thereof in the decision, since such involvement inevitably encounters difficulties. The common law’s dilemmas require drastic solutions, but the common law arguably is illequipped to implement the required change. The answer, it will be argued, is ...

  3. Bias During the Evaluation of Animal Studies?

    OpenAIRE

    Andrew Knight

    2012-01-01

    Simple Summary Animal experimentation evokes strong emotional responses in people on both sides of the debate surrounding its ethical status. However, the true level of its usefulness to society may only be discerned by careful examination of reliable scientific evidence. My recent book, The Costs and Benefits of Animal Experiments, reviewed more than 500 relevant scientific publications. Recently in this journal, however, a reviewer essentially accused me of bias. Yet the conclusions of my b...

  4. Modeling confirmation bias and polarization

    Science.gov (United States)

    Del Vicario, Michela; Scala, Antonio; Caldarelli, Guido; Stanley, H. Eugene; Quattrociocchi, Walter

    2017-01-01

    Online users tend to select claims that adhere to their system of beliefs and to ignore dissenting information. Confirmation bias, indeed, plays a pivotal role in viral phenomena. Furthermore, the wide availability of content on the web fosters the aggregation of likeminded people where debates tend to enforce group polarization. Such a configuration might alter the public debate and thus the formation of the public opinion. In this paper we provide a mathematical model to study online social debates and the related polarization dynamics. We assume the basic updating rule of the Bounded Confidence Model (BCM) and we develop two variations a) the Rewire with Bounded Confidence Model (RBCM), in which discordant links are broken until convergence is reached; and b) the Unbounded Confidence Model, under which the interaction among discordant pairs of users is allowed even with a negative feedback, either with the rewiring step (RUCM) or without it (UCM). From numerical simulations we find that the new models (UCM and RUCM), unlike the BCM, are able to explain the coexistence of two stable final opinions, often observed in reality. Lastly, we present a mean field approximation of the newly introduced models. PMID:28074874

  5. Modeling confirmation bias and polarization

    Science.gov (United States)

    Del Vicario, Michela; Scala, Antonio; Caldarelli, Guido; Stanley, H. Eugene; Quattrociocchi, Walter

    2017-01-01

    Online users tend to select claims that adhere to their system of beliefs and to ignore dissenting information. Confirmation bias, indeed, plays a pivotal role in viral phenomena. Furthermore, the wide availability of content on the web fosters the aggregation of likeminded people where debates tend to enforce group polarization. Such a configuration might alter the public debate and thus the formation of the public opinion. In this paper we provide a mathematical model to study online social debates and the related polarization dynamics. We assume the basic updating rule of the Bounded Confidence Model (BCM) and we develop two variations a) the Rewire with Bounded Confidence Model (RBCM), in which discordant links are broken until convergence is reached; and b) the Unbounded Confidence Model, under which the interaction among discordant pairs of users is allowed even with a negative feedback, either with the rewiring step (RUCM) or without it (UCM). From numerical simulations we find that the new models (UCM and RUCM), unlike the BCM, are able to explain the coexistence of two stable final opinions, often observed in reality. Lastly, we present a mean field approximation of the newly introduced models.

  6. Behavioral Biases in Interpersonal Contexts

    NARCIS (Netherlands)

    N. Liu (Ning)

    2017-01-01

    markdownabstractThis thesis presents evidence suggesting that the same types of biases in individual decision making under uncertainty pertain in interpersonal contexts. The chapters above demonstrate in specific contexts how specific interpersonal factors attenuate, amplify, or replicate these bias

  7. Assessing Bias in Search Engines.

    Science.gov (United States)

    Mowshowitz, Abbe; Kawaguchi, Akira

    2002-01-01

    Addresses the measurement of bias in search engines on the Web, defining bias as the balance and representation of items in a collection retrieved from a database for a set of queries. Assesses bias by measuring the deviation from the ideal of the distribution produced by a particular search engine. (Author/LRW)

  8. Inferential selection bias in a study of racial bias: Revisiting ‘Working twice as hard to get half as far’

    Directory of Open Access Journals (Sweden)

    LJ Zigerell

    2015-02-01

    Full Text Available This study revisits an important recent article about racial bias and finds that many of its inferences are weakened when we analyze the data more completely. DeSante in 2013 reported evidence from a survey experiment indicating that Americans reward Whites more than Blacks for hard work but penalize Blacks more than Whites for laziness. However, the present study demonstrates that these inferences were based on an unrepresentative selection of possible analyses: the original article does not include all possible equivalent or relevant analyses, and when results from these additional analyses are combined with the results reported in the original article, the strength of inferences is weakened. Moreover, newly-reported evidence reveals heterogeneity in racial bias: respondents given a direct choice between equivalent targets of different races favored the Black target over the White target. These results illustrate how the presence of researcher degrees of freedom can foster production of inferences that are not representative of all inferences that a set of data could produce. This study thus highlights the value of preregistering research design protocols and required public posting of data.

  9. The breadth and mnemonic consequences of the youth bias

    DEFF Research Database (Denmark)

    Koppel, Jonathan; Berntsen, Dorthe

    2016-01-01

    .e., deaths of public figures, US Presidential elections, and sporting events). We then investigated the possible role of the youth bias in structuring recall for public events, by probing, within-subjects, for the relation between: (1) These expectations of the timing, in a typical person’s life, of the most...

  10. Challenges of guarantee-time bias.

    Science.gov (United States)

    Giobbie-Hurder, Anita; Gelber, Richard D; Regan, Meredith M

    2013-08-10

    The potential for guarantee-time bias (GTB), also known as immortal time bias, exists whenever an analysis that is timed from enrollment or random assignment, such as disease-free or overall survival, is compared across groups defined by a classifying event occurring sometime during follow-up. The types of events associated with GTB are varied and may include the occurrence of objective disease response, onset of toxicity, or seroconversion. However, comparative analyses using these types of events as predictors are different from analyses using baseline characteristics that are specified completely before the occurrence of any outcome event. Recognizing the potential for GTB is not always straightforward, and it can be challenging to know when GTB is influencing the results of an analysis. This article defines GTB, provides examples of GTB from several published articles, and discusses three analytic techniques that can be used to remove the bias: conditional landmark analysis, extended Cox model, and inverse probability weighting. The strengths and limitations of each technique are presented. As an example, we explore the effect of bisphosphonate use on disease-free survival (DFS) using data from the BIG (Breast International Group) 1-98 randomized clinical trial. An analysis using a naive approach showed substantial benefit for patients who received bisphosphonate therapy. In contrast, analyses using the three methods known to remove GTB showed no statistical evidence of a reduction in risk of a DFS event with bisphosphonate therapy.

  11. Positioning of Weight Bias: Moving towards Social Justice

    Science.gov (United States)

    Alberga, Angela S.; Kassan, Anusha; Sesma-Vazquez, Monica

    2016-01-01

    Weight bias is a form of stigma with detrimental effects on the health and wellness of individuals with large bodies. Researchers from various disciplines have recognized weight bias as an important topic for public health and for professional practice. To date, researchers from various areas have approached weight bias from independent perspectives and from differing theoretical orientations. In this paper, we examined the similarities and differences between three perspectives (i.e., weight-centric, non-weight-centric (health-centric), and health at every size) used to understand weight bias and approach weight bias research with regard to (a) language about people with large bodies, (b) theoretical position, (c) identified consequences of weight bias, and (d) identified influences on weight-based social inequity. We suggest that, despite differences, each perspective acknowledges the negative influences that position weight as being within individual control and the negative consequences of weight bias. We call for recognition and discussion of weight bias as a social justice issue in order to change the discourse and professional practices extended towards individuals with large bodies. We advocate for an emphasis on social justice as a uniting framework for interdisciplinary research on weight bias.

  12. Modeling Temporal Bias of Uplift Events in Recommender Systems

    KAUST Repository

    Altaf, Basmah

    2013-05-08

    Today, commercial industry spends huge amount of resources in advertisement campaigns, new marketing strategies, and promotional deals to introduce their product to public and attract a large number of customers. These massive investments by a company are worthwhile because marketing tactics greatly influence the consumer behavior. Alternatively, these advertising campaigns have a discernible impact on recommendation systems which tend to promote popular items by ranking them at the top, resulting in biased and unfair decision making and loss of customers’ trust. The biasing impact of popularity of items on recommendations, however, is not fixed, and varies with time. Therefore, it is important to build a bias-aware recommendation system that can rank or predict items based on their true merit at given time frame. This thesis proposes a framework that can model the temporal bias of individual items defined by their characteristic contents, and provides a simple process for bias correction. Bias correction is done either by cleaning the bias from historical training data that is used for building predictive model, or by ignoring the estimated bias from the predictions of a standard predictor. Evaluated on two real world datasets, NetFlix and MovieLens, our framework is shown to be able to estimate and remove the bias as a result of adopted marketing techniques from the predicted popularity of items at a given time.

  13. Positioning of Weight Bias: Moving towards Social Justice

    Directory of Open Access Journals (Sweden)

    Sarah Nutter

    2016-01-01

    Full Text Available Weight bias is a form of stigma with detrimental effects on the health and wellness of individuals with large bodies. Researchers from various disciplines have recognized weight bias as an important topic for public health and for professional practice. To date, researchers from various areas have approached weight bias from independent perspectives and from differing theoretical orientations. In this paper, we examined the similarities and differences between three perspectives (i.e., weight-centric, non-weight-centric (health-centric, and health at every size used to understand weight bias and approach weight bias research with regard to (a language about people with large bodies, (b theoretical position, (c identified consequences of weight bias, and (d identified influences on weight-based social inequity. We suggest that, despite differences, each perspective acknowledges the negative influences that position weight as being within individual control and the negative consequences of weight bias. We call for recognition and discussion of weight bias as a social justice issue in order to change the discourse and professional practices extended towards individuals with large bodies. We advocate for an emphasis on social justice as a uniting framework for interdisciplinary research on weight bias.

  14. The breadth and mnemonic consequences of the youth bias

    DEFF Research Database (Denmark)

    Koppel, Jonathan; Berntsen, Dorthe

    2016-01-01

    .e., deaths of public figures, US Presidential elections, and sporting events). We then investigated the possible role of the youth bias in structuring recall for public events, by probing, within-subjects, for the relation between: (1) These expectations of the timing, in a typical person’s life, of the most...... question were correlated with the age at which the recalled event occurred, but only where particularly salient historical events did not play a central role in driving recall (i.e., for sporting events). We conclude that the youth bias holds across different types of public events and provides a default......We have recently demonstrated the existence of the youth bias, referring to a tendency to favor adolescence and early adulthood over other lifetime periods when making inferences about the timing of important public events across the lifespan of a typical individual within one’s culture. The youth...

  15. Bias aware Kalman filters

    DEFF Research Database (Denmark)

    Drecourt, J.-P.; Madsen, H.; Rosbjerg, Dan

    2006-01-01

    . The colored noise filter formulation is extended to correct both time correlated and uncorrelated model error components. A more stable version of the separate filter without feedback is presented. The filters are implemented in an ensemble framework using Latin hypercube sampling. The techniques...... are illustrated on a simple one-dimensional groundwater problem. The results show that the presented filters outperform the standard Kalman filter and that the implementations with bias feedback work in more general conditions than the implementations without feedback. 2005 Elsevier Ltd. All rights reserved....

  16. TIC et expression démocratique en Afrique : mirage ou virage ? Essai d’analyse wébométrique de l’espace public numérique sénégalais

    OpenAIRE

    2014-01-01

    International audience; Au Sénégal, malgré un taux de pénétration d’internet assez faible le monde politique n’est pas insensible aux opportunités qu’offrent les TIC. À l’occasion des élections présidentielles de 2012, les partis politiques ont investi des moyens humains et financiers dans le but de créer une interactivité numérique avec le public. Pendant ce temps se développe un e-engagement citoyen qui se révèle à travers l’utilisation des médias sociaux. Par une analyse wébométrique, cet ...

  17. The Public Sector in the Czech Republic in Light of the Public Choice Theory

    Directory of Open Access Journals (Sweden)

    Václav Rybáček

    2016-06-01

    Full Text Available The aim of this paper is to discuss pros and cons of the current ways how the role of government in the society is analysed. In our analysis, macroeconomic aggregates provided by the satellite accounts of the public sector are used as an alternative analytical tool. This data supposedly better reflects the existing range of government activities as all government controlled entities are covered. Relevant time series by the Czech Statistical Office were prolonged making the analysis of long-term trends in the public sector size possible. The results are discussed against the theoretical background of the public choice theory. It was found out that there was an obvious bias to the deficit-driven provision of the public goods reflected concurrently in the growing indebtedness. On the other hand, the share of total revenues and expenditures remains rather stable over time.

  18. Application and investigation of a bound for outcome reporting bias

    Directory of Open Access Journals (Sweden)

    Gamble Carrol

    2007-03-01

    Full Text Available Abstract Background Direct empirical evidence for the existence of outcome reporting bias is accumulating and this source of bias is recognised as a potential threat to the validity of meta-analysis of randomised clinical trials. Methods A method for calculating the maximum bias in a meta-analysis due to publication bias is adapted for the setting where within-study selective non-reporting of outcomes is suspected, and compared to the alternative approach of missing data imputation. The properties of both methods are investigated in realistic small sample situations. Results The results suggest that the adapted Copas and Jackson approach is the preferred method for reviewers to apply as an initial assessment of robustness to within-study selective non-reporting. Conclusion The Copas and Jackson approach is a useful method for systematic reviewers to apply to assess robustness to outcome reporting bias.

  19. Systematic tests for position-dependent additive shear bias

    CERN Document Server

    van Uitert, Edo

    2016-01-01

    We present new tests to identify stationary position-dependent additive shear biases in weak gravitational lensing data sets. These tests are important diagnostics for currently ongoing and planned cosmic shear surveys, as such biases induce coherent shear patterns that can mimic and potentially bias the cosmic shear signal. The central idea of these tests is to determine the average ellipticity of all galaxies with shape measurements in a grid in the pixel plane. The distribution of the absolute values of these averaged ellipticities can be compared to randomized catalogues; a difference points to systematics in the data. In addition, we introduce a method to quantify the spatial correlation of the additive bias, which suppresses the contribution from cosmic shear and therefore eases the identification of a position-dependent additive shear bias in the data. We apply these tests to the publicly available shear catalogues from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS) and the Kilo Degree Su...

  20. Weight bias against women in a university acceptance scenario.

    Science.gov (United States)

    Swami, Viren; Monk, Rachael

    2013-01-01

    This study examined weight bias against women in a hypothetical university acceptance scenario. One-hundred-and-ninety-eight volunteers from the community in Britain completed a weight bias measure in which they were asked to select the woman they were most and least likely to select for a place at university from an array of figures varying in body size. Participants also completed the Anti-Fat Attitudes Survey, the Short-Form of the Fat Phobia Scale, the Attitudes Toward Obese Persons Scale, and the Beliefs About Obese Persons Scale. Results showed that participants were biased against both obese (> 30 kg/m(2)) and emaciated (bias was only significantly predicted by greater antipathy toward fat persons and more negative attitudes toward obese persons. These results provide evidence that the general public hold biased beliefs about access to higher educational opportunities as a function of the body size of applicants.

  1. Racial bias shapes social reinforcement learning.

    Science.gov (United States)

    Lindström, Björn; Selbing, Ida; Molapour, Tanaz; Olsson, Andreas

    2014-03-01

    Both emotional facial expressions and markers of racial-group belonging are ubiquitous signals in social interaction, but little is known about how these signals together affect future behavior through learning. To address this issue, we investigated how emotional (threatening or friendly) in-group and out-group faces reinforced behavior in a reinforcement-learning task. We asked whether reinforcement learning would be modulated by intergroup attitudes (i.e., racial bias). The results showed that individual differences in racial bias critically modulated reinforcement learning. As predicted, racial bias was associated with more efficiently learned avoidance of threatening out-group individuals. We used computational modeling analysis to quantitatively delimit the underlying processes affected by social reinforcement. These analyses showed that racial bias modulates the rate at which exposure to threatening out-group individuals is transformed into future avoidance behavior. In concert, these results shed new light on the learning processes underlying social interaction with racial-in-group and out-group individuals.

  2. Outcome predictability biases learning.

    Science.gov (United States)

    Griffiths, Oren; Mitchell, Chris J; Bethmont, Anna; Lovibond, Peter F

    2015-01-01

    Much of contemporary associative learning research is focused on understanding how and when the associative history of cues affects later learning about those cues. Very little work has investigated the effects of the associative history of outcomes on human learning. Three experiments extended the "learned irrelevance" paradigm from the animal conditioning literature to examine the influence of an outcome's prior predictability on subsequent learning of relationships between cues and that outcome. All 3 experiments found evidence for the idea that learning is biased by the prior predictability of the outcome. Previously predictable outcomes were readily associated with novel predictive cues, whereas previously unpredictable outcomes were more readily associated with novel nonpredictive cues. This finding highlights the importance of considering the associative history of outcomes, as well as cues, when interpreting multistage designs. Associative and cognitive explanations of this certainty matching effect are discussed.

  3. Gender bias in scholarly peer review

    Science.gov (United States)

    Helmer, Markus; Schottdorf, Manuel; Neef, Andreas; Battaglia, Demian

    2017-01-01

    Peer review is the cornerstone of scholarly publishing and it is essential that peer reviewers are appointed on the basis of their expertise alone. However, it is difficult to check for any bias in the peer-review process because the identity of peer reviewers generally remains confidential. Here, using public information about the identities of 9000 editors and 43000 reviewers from the Frontiers series of journals, we show that women are underrepresented in the peer-review process, that editors of both genders operate with substantial same-gender preference (homophily), and that the mechanisms of this homophily are gender-dependent. We also show that homophily will persist even if numerical parity between genders is reached, highlighting the need for increased efforts to combat subtler forms of gender bias in scholarly publishing. DOI: http://dx.doi.org/10.7554/eLife.21718.001

  4. Gender bias in scholarly peer review.

    Science.gov (United States)

    Helmer, Markus; Schottdorf, Manuel; Neef, Andreas; Battaglia, Demian

    2017-03-21

    Peer review is the cornerstone of scholarly publishing and it is essential that peer reviewers are appointed on the basis of their expertise alone. However, it is difficult to check for any bias in the peer-review process because the identity of peer reviewers generally remains confidential. Here, using public information about the identities of 9000 editors and 43000 reviewers from the Frontiers series of journals, we show that women are underrepresented in the peer-review process, that editors of both genders operate with substantial same-gender preference (homophily), and that the mechanisms of this homophily are gender-dependent. We also show that homophily will persist even if numerical parity between genders is reached, highlighting the need for increased efforts to combat subtler forms of gender bias in scholarly publishing.

  5. Estimating Production Potentials: Expert Bias in Applied Decision Making

    Energy Technology Data Exchange (ETDEWEB)

    L. J. Matthews; L. K. Burggraf (ISU); W. J. Reece (INEEL)

    1998-10-01

    A study was conducted to evaluate how workers predict manufacturing production potentials given positively and negatively framed information. Findings indicate the existence of a bias toward positive information and suggest that this bias may be reduced with experience but is never the less maintained. Experts err in the same way non experts do in differentially processing negative and positive information. Additionally, both experts and non experts tend to overestimate production potentials in a positive direction. The authors propose that these biases should be addressed with further research including cross domain analyses and consideration in training, workplace design, and human performance modeling.

  6. Theoretical investigation of exchange bias

    Institute of Scientific and Technical Information of China (English)

    Xiong Zhi-Jie; Wang Huai-Yu; Ding Ze-Jun

    2007-01-01

    The exchange bias of bilayer magnetic films consisting of ferromagnetic (FM) and antiferromagnetic (AFM) layers in an uncompensated case is studied by use of the many-body Green's function method of quantum statistical theory.The effects of the layer thickness and temperature and the interfacial coupling strength on the exchange bias HE are investigated. The dependence of the exchange bias HE on the FM layer thickness and temperature is qualitatively in agreement with experimental results. When temperature varies, both the coercivity HC and HE decrease with the temperature increasing. For each FM thickness, there exists a least AFM thickness in which the exchange bias occurs,which is called pinning thickness.

  7. Sex bias in psychoactive drug advertisements.

    Science.gov (United States)

    King, E

    1980-05-01

    A recent concern has been the possible effect of sex-role stereotypes upon physicians' prescription patterns. In an attempt to examine the part played by drug advertisements, this paper will present a content analysis of psychoactive (mood-modifying) drug ads appearing in the American Journal of Psychiatry over a 17-year period; and a study of subjects' perceptions of the patients depicted in these drug ads across eight dimensions emerging from the content analysis. An initial perusal of psychoactive drug ads in professional medical journals suggested the existence of a sex bias: Females appeared to be presented as patients more often than males, and in a much more demeaning manner. The present analyses were done in an attempt to discover if a sex bias does exist in drug advertisements, which may influence the physician's perception of his or her patients, and subsequently, his or her prescription patterns.

  8. Calibration biases in logical reasoning tasks

    Directory of Open Access Journals (Sweden)

    Guillermo Macbeth

    2013-08-01

    Full Text Available The aim of this contribution is to present an experimental study about calibration in deductive reasoning tasks. Calibration is defi ned as the empirical convergence or divergence between the objective and the subjective success. The underconfi dence bias is understood as the dominance of the former over the latter. The hypothesis of this study states that the form of the propositions presented in the experiment is critical for calibration phenomena. Affi rmative and negative propositions are distinguished in their cognitive processing. Results suggests that monotonous compound propositions are prone to underconfi dence. An heuristic approach to this phenomenon is proposed. The activation of a monotony heuristic would produce an illusion of simplicity that generates the calibration bias. These evidence is analysed in the context of the metacognitive modeling of calibration phenomena.

  9. Bias in clinical intervention research

    DEFF Research Database (Denmark)

    Gluud, Lise Lotte

    2006-01-01

    Research on bias in clinical trials may help identify some of the reasons why investigators sometimes reach the wrong conclusions about intervention effects. Several quality components for the assessment of bias control have been suggested, but although they seem intrinsically valid, empirical...

  10. Bias in the Mass Media.

    Science.gov (United States)

    Cirino, Robert

    Non-language elements of bias in mass media--such as images, sounds, tones of voices, inflection, and facial expressions--are invariably integrated with the choice of language. Further, they have an emotional impact that is often greater than that of language. It is essential that the teacher of English deal with this non-language bias since it is…

  11. Sequential biases in accumulating evidence

    Science.gov (United States)

    Huggins, Richard; Dogo, Samson Henry

    2015-01-01

    Whilst it is common in clinical trials to use the results of tests at one phase to decide whether to continue to the next phase and to subsequently design the next phase, we show that this can lead to biased results in evidence synthesis. Two new kinds of bias associated with accumulating evidence, termed ‘sequential decision bias’ and ‘sequential design bias’, are identified. Both kinds of bias are the result of making decisions on the usefulness of a new study, or its design, based on the previous studies. Sequential decision bias is determined by the correlation between the value of the current estimated effect and the probability of conducting an additional study. Sequential design bias arises from using the estimated value instead of the clinically relevant value of an effect in sample size calculations. We considered both the fixed‐effect and the random‐effects models of meta‐analysis and demonstrated analytically and by simulations that in both settings the problems due to sequential biases are apparent. According to our simulations, the sequential biases increase with increased heterogeneity. Minimisation of sequential biases arises as a new and important research area necessary for successful evidence‐based approaches to the development of science. © 2015 The Authors. Research Synthesis Methods Published by John Wiley & Sons Ltd. PMID:26626562

  12. Analysis of ESP Syllabus: Analysing the Book Basic English for Computing as a Sample and Testing its Suitability for ESP Learners in Public and Private Yemeni and Saudi Arabian Universities

    Directory of Open Access Journals (Sweden)

    Ahmed Mohammed S. Alduais

    2012-11-01

    Full Text Available Any syllabus could be evaluated and analysed in terms of design and format and achieving the goals of the designed syllabus in reality; in this paper the first type of analysis is conducted in addition to integrating the researcher’s experience of teaching ESP in Yemen and Saudi Arabia. Reviewing previous and related literature along with collected data from the text book, the researcher used different types of methodologies to come up with detailed analysis of the above named ESP book. The book Basic English for Computing seems to have high standard design and format as an ESP curriculum in terms of: planning stage, implementation, evaluation, and management, and in terms of selection and grading of the content and tasks of the curriculum as an ESP syllabus as well. However and from the research’s perspective, this syllabus in spite of its high standards, it doesn’t suit the level of ESP learners in both public and private Yemeni Universities due to misuse and wrong interpretation of the term ESP in Yemen among English teachers, specialists in the field of English language and decision-makers as well. It is the learner, the environment learning, and the teacher rather than the book that would greatly affect on deciding the success of achieving the goals of a certain syllabus and testing its usability in a certain country where English is being taught and/or learned for specific purposes.

  13. Large-Scale Galaxy Bias

    CERN Document Server

    Desjacques, Vincent; Schmidt, Fabian

    2016-01-01

    This review presents a comprehensive overview of galaxy bias, that is, the statistical relation between the distribution of galaxies and matter. We focus on large scales where cosmic density fields are quasi-linear. On these scales, the clustering of galaxies can be described by a perturbative bias expansion, and the complicated physics of galaxy formation is absorbed by a finite set of coefficients of the expansion, called bias parameters. The review begins with a pedagogical proof of this very important result, which forms the basis of the rigorous perturbative description of galaxy clustering, under the assumptions of General Relativity and Gaussian, adiabatic initial conditions. Key components of the bias expansion are all leading local gravitational observables, which includes the matter density but also tidal fields and their time derivatives. We hence expand the definition of local bias to encompass all these contributions. This derivation is followed by a presentation of the peak-background split in i...

  14. Preferential Use of Public TCR during Autoimmune Encephalomyelitis.

    Science.gov (United States)

    Zhao, Yunqian; Nguyen, Phuong; Ma, Jing; Wu, Tianhua; Jones, Lindsay L; Pei, Deqing; Cheng, Cheng; Geiger, Terrence L

    2016-06-15

    How the TCR repertoire, in concert with risk-associated MHC, imposes susceptibility for autoimmune diseases is incompletely resolved. Due largely to recombinatorial biases, a small fraction of TCRα or β-chains are shared by most individuals, or public. If public TCR chains modulate a TCRαβ heterodimer's likelihood of productively engaging autoantigen, because they are pervasive and often high frequency, they could also broadly influence disease risk and progression. Prior data, using low-resolution techniques, have identified the heavy use of select public TCR in some autoimmune models. In this study, we assess public repertoire representation in mice with experimental autoimmune encephalomyelitis at high resolution. Saturation sequencing was used to identify >18 × 10(6) TCRβ sequences from the CNSs, periphery, and thymi of mice at different stages of autoimmune encephalomyelitis and healthy controls. Analyses indicated the prominent representation of a highly diverse public TCRβ repertoire in the disease response. Preferential formation of public TCR implicated in autoimmunity was identified in preselection thymocytes, and, consistently, public, disease-associated TCRβ were observed to be commonly oligoclonal. Increased TCR sharing and a focusing of the public TCR response was seen with disease progression. Critically, comparisons of peripheral and CNS repertoires and repertoires from preimmune and diseased mice demonstrated that public TCR were preferentially deployed relative to nonshared, or private, sequences. Our findings implicate public TCR in skewing repertoire response during autoimmunity and suggest that subsets of public TCR sequences may serve as disease-specific biomarkers or influence disease susceptibility or progression.

  15. Optimal classifier selection and negative bias in error rate estimation: an empirical study on high-dimensional prediction

    Directory of Open Access Journals (Sweden)

    Boulesteix Anne-Laure

    2009-12-01

    Full Text Available Abstract Background In biometric practice, researchers often apply a large number of different methods in a "trial-and-error" strategy to get as much as possible out of their data and, due to publication pressure or pressure from the consulting customer, present only the most favorable results. This strategy may induce a substantial optimistic bias in prediction error estimation, which is quantitatively assessed in the present manuscript. The focus of our work is on class prediction based on high-dimensional data (e.g. microarray data, since such analyses are particularly exposed to this kind of bias. Methods In our study we consider a total of 124 variants of classifiers (possibly including variable selection or tuning steps within a cross-validation evaluation scheme. The classifiers are applied to original and modified real microarray data sets, some of which are obtained by randomly permuting the class labels to mimic non-informative predictors while preserving their correlation structure. Results We assess the minimal misclassification rate over the different variants of classifiers in order to quantify the bias arising when the optimal classifier is selected a posteriori in a data-driven manner. The bias resulting from the parameter tuning (including gene selection parameters as a special case and the bias resulting from the choice of the classification method are examined both separately and jointly. Conclusions The median minimal error rate over the investigated classifiers was as low as 31% and 41% based on permuted uninformative predictors from studies on colon cancer and prostate cancer, respectively. We conclude that the strategy to present only the optimal result is not acceptable because it yields a substantial bias in error rate estimation, and suggest alternative approaches for properly reporting classification accuracy.

  16. Bias and ignorance in demographic perception.

    Science.gov (United States)

    Landy, D; Guay, B; Marghetis, T

    2017-08-31

    When it comes to knowledge of demographic facts, misinformation appears to be the norm. Americans massively overestimate the proportions of their fellow citizens who are immigrants, Muslim, LGBTQ, and Latino, but underestimate those who are White or Christian. Previous explanations of these estimation errors have invoked topic-specific mechanisms such as xenophobia or media bias. We reconsidered this pattern of errors in the light of more than 30 years of research on the psychological processes involved in proportion estimation and decision-making under uncertainty. In two publicly available datasets featuring demographic estimates from 14 countries, we found that proportion estimates of national demographics correspond closely to what is found in laboratory studies of quantitative estimates more generally. Biases in demographic estimation, therefore, are part of a very general pattern of human psychology-independent of the particular topic or demographic under consideration-that explains most of the error in estimates of the size of politically salient populations. By situating demographic estimates within a broader understanding of general quantity estimation, these results demand reevaluation of both topic-specific misinformation about demographic facts and topic-specific explanations of demographic ignorance, such as media bias and xenophobia.

  17. Assembly bias and splashback in galaxy clusters

    Science.gov (United States)

    Busch, Philipp; White, Simon D. M.

    2017-10-01

    We use publicly available data for the Millennium Simulation to explore the implications of the recent detection of assembly bias and splashback signatures in a large sample of galaxy clusters. These were identified in the Sloan Digital Sky Survey/Data Release 8 (SDSS/DR8) photometric data by the redMaPPer algorithm and split into high- and low-concentration subsamples based on the projected positions of cluster members. We use simplified versions of these procedures to build cluster samples of similar size from the simulation data. These match the observed samples quite well and show similar assembly bias and splashback signals. Previous theoretical work has found the logarithmic slope of halo density profiles to have a well-defined minimum whose depth decreases and whose radius increases with halo concentration. Projected profiles for the observed and simulated cluster samples show trends with concentration which are opposite to these predictions. In addition, for high-concentration clusters the minimum slope occurs at significantly smaller radius than predicted. We show that these discrepancies all reflect confusion between splashback features and features imposed on the profiles by the cluster identification and concentration estimation procedures. The strong apparent assembly bias is not reflected in the three-dimensional distribution of matter around clusters. Rather it is a consequence of the preferential contamination of low-concentration clusters by foreground or background groups.

  18. No difference found in time to publication by statistical significance of trial results: a methodological review

    Science.gov (United States)

    Jefferson, L; Cooper, E; Hewitt, C; Torgerson, T; Cook, L; Tharmanathan, P; Cockayne, S; Torgerson, D

    2016-01-01

    Objective Time-lag from study completion to publication is a potential source of publication bias in randomised controlled trials. This study sought to update the evidence base by identifying the effect of the statistical significance of research findings on time to publication of trial results. Design Literature searches were carried out in four general medical journals from June 2013 to June 2014 inclusive (BMJ, JAMA, the Lancet and the New England Journal of Medicine). Setting Methodological review of four general medical journals. Participants Original research articles presenting the primary analyses from phase 2, 3 and 4 parallel-group randomised controlled trials were included. Main outcome measures Time from trial completion to publication. Results The median time from trial completion to publication was 431 days (n = 208, interquartile range 278–618). A multivariable adjusted Cox model found no statistically significant difference in time to publication for trials reporting positive or negative results (hazard ratio: 0.86, 95% CI 0.64 to 1.16, p = 0.32). Conclusion In contrast to previous studies, this review did not demonstrate the presence of time-lag bias in time to publication. This may be a result of these articles being published in four high-impact general medical journals that may be more inclined to publish rapidly, whatever the findings. Further research is needed to explore the presence of time-lag bias in lower quality studies and lower impact journals. PMID:27757242

  19. Administrative bias in South Africa

    Directory of Open Access Journals (Sweden)

    E S Nwauche

    2005-01-01

    Full Text Available This article reviews the interpretation of section 6(2(aii of the Promotion of Administrative Justice Act which makes an administrator “biased or reasonably suspected of bias” a ground of judicial review. In this regard, the paper reviews the determination of administrative bias in South Africa especially highlighting the concept of institutional bias. The paper notes that inspite of the formulation of the bias ground of review the test for administrative bias is the reasonable apprehension test laid down in the case of President of South Africa v South African Rugby Football Union(2 which on close examination is not the same thing. Accordingly the paper urges an alternative interpretation that is based on the reasonable suspicion test enunciated in BTR Industries South Africa (Pty Ltd v Metal and Allied Workers Union and R v Roberts. Within this context, the paper constructs a model for interpreting the bias ground of review that combines the reasonable suspicion test as interpreted in BTR Industries and R v Roberts, the possibility of the waiver of administrative bias, the curative mechanism of administrative appeal as well as some level of judicial review exemplified by the jurisprudence of article 6(1 of the European Convention of Human Rights, especially in the light of the contemplation of the South African Magistrate Court as a jurisdictional route of judicial review.

  20. Cognitive Bias in Systems Verification

    Science.gov (United States)

    Larson, Steve

    2012-01-01

    Working definition of cognitive bias: Patterns by which information is sought and interpreted that can lead to systematic errors in decisions. Cognitive bias is used in diverse fields: Economics, Politics, Intelligence, Marketing, to name a few. Attempts to ground cognitive science in physical characteristics of the cognitive apparatus exceed our knowledge. Studies based on correlations; strict cause and effect is difficult to pinpoint. Effects cited in the paper and discussed here have been replicated many times over, and appear sound. Many biases have been described, but it is still unclear whether they are all distinct. There may only be a handful of fundamental biases, which manifest in various ways. Bias can effect system verification in many ways . Overconfidence -> Questionable decisions to deploy. Availability -> Inability to conceive critical tests. Representativeness -> Overinterpretation of results. Positive Test Strategies -> Confirmation bias. Debiasing at individual level very difficult. The potential effect of bias on the verification process can be managed, but not eliminated. Worth considering at key points in the process.

  1. Cognitive Bias in Systems Verification

    Science.gov (United States)

    Larson, Steve

    2012-01-01

    Working definition of cognitive bias: Patterns by which information is sought and interpreted that can lead to systematic errors in decisions. Cognitive bias is used in diverse fields: Economics, Politics, Intelligence, Marketing, to name a few. Attempts to ground cognitive science in physical characteristics of the cognitive apparatus exceed our knowledge. Studies based on correlations; strict cause and effect is difficult to pinpoint. Effects cited in the paper and discussed here have been replicated many times over, and appear sound. Many biases have been described, but it is still unclear whether they are all distinct. There may only be a handful of fundamental biases, which manifest in various ways. Bias can effect system verification in many ways . Overconfidence -> Questionable decisions to deploy. Availability -> Inability to conceive critical tests. Representativeness -> Overinterpretation of results. Positive Test Strategies -> Confirmation bias. Debiasing at individual level very difficult. The potential effect of bias on the verification process can be managed, but not eliminated. Worth considering at key points in the process.

  2. FractBias: a graphical tool for assessing fractionation bias following polyploidy.

    Science.gov (United States)

    Joyce, Blake L; Haug-Baltzell, Asher; Davey, Sean; Bomhoff, Matthew; Schnable, James C; Lyons, Eric

    2017-02-15

    Following polyploidy events, genomes undergo massive reduction in gene content through a process known as fractionation. Importantly, the fractionation process is not always random, and a bias as to which homeologous chromosome retains or loses more genes can be observed in some species. The process of characterizing whole genome fractionation requires identifying syntenic regions across genomes followed by post-processing of those syntenic datasets to identify and plot gene retention patterns. We have developed a tool, FractBias, to calculate and visualize gene retention and fractionation patterns across whole genomes. Through integration with SynMap and its parent platform CoGe, assembled genomes are pre-loaded and available for analysis, as well as letting researchers integrate their own data with security options to keep them private or make them publicly available. FractBias is freely available as a web application at https://genomevolution.org/CoGe/SynMap.pl . The software is open source (MIT license) and executable with Python 2.7 or iPython notebook, and available on GitHub ( https://goo.gl/PaAtqy ). Documentation for FractBias is available on CoGepedia ( https://goo.gl/ou9dt6 ). ericlyons@email.arizona.edu. Supplementary data are available at Bioinformatics online.

  3. Meta-analyses on viral hepatitis

    DEFF Research Database (Denmark)

    Gluud, Lise L; Gluud, Christian

    2009-01-01

    This article summarizes the meta-analyses of interventions for viral hepatitis A, B, and C. Some of the interventions assessed are described in small trials with unclear bias control. Other interventions are supported by large, high-quality trials. Although attempts have been made to adjust...

  4. Bias During the Evaluation of Animal Studies?

    Science.gov (United States)

    Knight, Andrew

    2012-01-01

    Simple Summary Animal experimentation evokes strong emotional responses in people on both sides of the debate surrounding its ethical status. However, the true level of its usefulness to society may only be discerned by careful examination of reliable scientific evidence. My recent book, The Costs and Benefits of Animal Experiments, reviewed more than 500 relevant scientific publications. Recently in this journal, however, a reviewer essentially accused me of bias. Yet the conclusions of my book are based on sound reasoning and strong evidence, and no critic has yet provided any substantive evidence to refute them. Abstract My recent book entitled The Costs and Benefits of Animal Experiments seeks to answer a key question within animal ethics, namely: is animal experimentation ethically justifiable? Or, more precisely, is it justifiable within the utilitarian cost:benefit framework that fundamentally underpins most regulations governing animal experimentation? To answer this question I reviewed more than 500 scientific publications describing animal studies, animal welfare impacts, and alternative research, toxicity testing and educational methodologies. To minimise bias I focused primarily on large-scale systematic reviews that had examined the human clinical and toxicological utility of animal studies. Despite this, Dr. Susanne Prankel recently reviewed my book in this journal, essentially accusing me of bias. However, she failed to provide any substantive evidence to refute my conclusions, let alone evidence of similar weight to that on which they are based. Those conclusions are, in fact, firmly based on utilitarian ethical reasoning, informed by scientific evidence of considerable strength, and I believe they are robust. PMID:26486779

  5. Asymmetric bias in user guided segmentations of brain structures.

    Science.gov (United States)

    Maltbie, Eric; Bhatt, Kshamta; Paniagua, Beatriz; Smith, Rachel G; Graves, Michael M; Mosconi, Matthew W; Peterson, Sarah; White, Scott; Blocher, Joseph; El-Sayed, Mohammed; Hazlett, Heather C; Styner, Martin A

    2012-01-16

    Brain morphometric studies often incorporate comparative hemispheric asymmetry analyses of segmented brain structures. In this work, we present evidence that common user guided structural segmentation techniques exhibit strong left-right asymmetric biases and thus fundamentally influence any left-right asymmetry analyses. In this study, MRI scans from ten pediatric subjects were employed for studying segmentations of amygdala, globus pallidus, putamen, caudate, and lateral ventricle. Additionally, two pediatric and three adult scans were used for studying hippocampus segmentation. Segmentations of the sub-cortical structures were performed by skilled raters using standard manual and semi-automated methods. The left-right mirrored versions of each image were included in the data and segmented in a random order to assess potential left-right asymmetric bias. Using shape analysis we further assessed whether the asymmetric bias is consistent across subjects and raters with the focus on the hippocampus. The user guided segmentation techniques on the sub-cortical structures exhibited left-right asymmetric volume bias with the hippocampus displaying the most significant asymmetry values (pstudy is to raise awareness in the neuroimaging community regarding the presence of the asymmetric bias and its influence on any left-right hemispheric analyses. We also recommend reexamining previous research results in the light of this new finding.

  6. Publication selection and the income elasticity of the value of a statistical life.

    Science.gov (United States)

    Doucouliagos, Hristos; Stanley, T D; Viscusi, W Kip

    2014-01-01

    Estimates of the value of a statistical life (VSL) establish the price government agencies use to value fatality risks. Transferring these valuations to other populations often utilizes the income elasticity of the VSL, which typically draw on estimates from meta-analyses. Using a data set consisting of 101 estimates of the income elasticity of VSL from 14 previously reported meta-analyses, we find that after accounting for potential publication bias the income elasticity of value of a statistical life is clearly and robustly inelastic, with a value of approximately 0.25-0.63. There is also clear evidence of the importance of controlling for levels of risk, differential publication selection bias, and the greater income sensitivity of VSL from stated preference surveys.

  7. Magnetic bearings with zero bias

    Science.gov (United States)

    Brown, Gerald V.; Grodsinsky, Carlos M.

    1991-01-01

    A magnetic bearing operating without a bias field has supported a shaft rotating at speeds up to 12,000 rpm with the usual four power supplies and with only two. A magnetic bearing is commonly operated with a bias current equal to half of the maximum current allowable in its coils. This linearizes the relation between net force and control current and improves the force slewing rate and hence the band width. The steady bias current dissipates power, even when no force is required from the bearing. The power wasted is equal to two-thirds of the power at maximum force output. Examined here is the zero bias idea. The advantages and disadvantages are noted.

  8. MLE's bias pathology motivates MCMLE

    OpenAIRE

    Yatracos, Yannis G.

    2013-01-01

    Maximum likelihood estimates are often biased. It is shown that this pathology is inherent to the traditional ML estimation method for two or more parameters, thus motivating from a different angle the use of MCMLE.

  9. Cognitive biases and language universals

    CERN Document Server

    Baronchelli, Andrea; Puglisi, Andrea

    2013-01-01

    Language universals have been longly attributed to an innate Universal Grammar. An alternative explanation states that linguistic universals emerged independently in every language in response to shared cognitive, though non language-specific, biases. A computational model has recently shown how this could be the case, focusing on the paradigmatic example of the universal properties of color naming patterns, and producing results in accurate agreement with the experimental data. Here we investigate thoroughly the role of a cognitive bias in the framework of this model. We study how, and to what extent, the structure of the bias can influence the corresponding linguistic universal patterns. We show also that the cultural history of a group of speakers introduces population-specific constraints that act against the uniforming pressure of the cognitive bias, and we clarify the interplay between these two forces. We believe that our simulations can help to shed light on the possible mechanisms at work in the evol...

  10. Minimum Bias Trigger in ATLAS

    CERN Document Server

    Kwee, R E; The ATLAS collaboration

    2010-01-01

    Since the restart of the LHC in November 2009, ATLAS has collected inelastic pp-collisions to perform first measurements on charged particle densities. These measurements will help to constrain various models describing phenomenologically soft parton interactions. Understanding the trigger efficiencies for different event types are therefore crucial to minimize any possible bias in the event selection. ATLAS uses two main minimum bias triggers, featuring complementary detector components and trigger levels. While a hardware based first trigger level situated in the forward regions with 2.09 < |eta| < 3.8 has been proven to select pp-collisions very efficiently, the Inner Detector based minimum bias trigger uses a random seed on filled bunches and central tracking detectors for the event selection. Both triggers were essential for the analysis of kinematic spectra of charged particles. Their performance and trigger efficiency measurements as well as studies on possible bias sources will be presen...

  11. Systematic tests for position-dependent additive shear bias

    Science.gov (United States)

    van Uitert, Edo; Schneider, Peter

    2016-11-01

    We present new tests to identify stationary position-dependent additive shear biases in weak gravitational lensing data sets. These tests are important diagnostics for currently ongoing and planned cosmic shear surveys, as such biases induce coherent shear patterns that can mimic and potentially bias the cosmic shear signal. The central idea of these tests is to determine the average ellipticity of all galaxies with shape measurements in a grid in the pixel plane. The distribution of the absolute values of these averaged ellipticities can be compared to randomised catalogues; a difference points to systematics in the data. In addition, we introduce a method to quantify the spatial correlation of the additive bias, which suppresses the contribution from cosmic shear and therefore eases the identification of a position-dependent additive shear bias in the data. We apply these tests to the publicly available shear catalogues from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS) and the Kilo Degree Survey (KiDS) and find evidence for a small but non-negligible residual additive bias at small scales. As this residual bias is smaller than the error on the shear correlation signal at those scales, it is highly unlikely that it causes a significant bias in the published cosmic shear results of CFHTLenS. In CFHTLenS, the amplitude of this systematic signal is consistent with zero in fields where the number of stars used to model the point spread function (PSF) is higher than average, suggesting that the position-dependent additive shear bias originates from undersampled PSF variations across the image.

  12. Artificial bias typically neglected in comparisons of uncertain atmospheric data

    Science.gov (United States)

    Pitkänen, Mikko R. A.; Mikkonen, Santtu; Lehtinen, Kari E. J.; Arola, Antti

    2016-04-01

    Researchers in atmospheric sciences frequently disregard data uncertainty in their choice of methods for data analysis and visualisation. Such methods include the widely used standard least squares line fitting in combination with some variations of scatter plots when comparing two different data sets of the same physical quantity. When using these methods, random data uncertainty (eg. measurement uncertainty) causes artificial systematic bias in the comparison between the extreme values of the data sets, which is then often interpreted falsely as a consequence of some true physical phenomenon or instrument misbehavior. This artificial bias is recognized as regression to the mean (RTM), that is a known effect in the field of statistics, but mostly disregarded in atmospheric sciences and not acknowledged at all in the vast majority of publications in our field. All kinds of data comparisons are subject to the bias, as long as uncertainty is present in the data. This work introduces the concept of RTM bias and demonstrates the necessity of considering the RTM effect in comparisons of data with uncertainties. We not only visualize the RTM effect with synthetic data but also use simulations based on real atmospheric data to estimate the magnitude of RTM bias in data comparisons common in our field. Typically, RTM bias is greater when the reference data (often on the x-axis) has greater uncertainty. For example, mid-visible aerosol optical thickness determined using a sun photometer may have a fairly low uncertainty of +-0.01 and, thus the RTM effect is small when using it as reference data. On the other hand UV index measurements with a broadband instrument may have an uncertainty of 10 % and higher, and the bias caused by RTM becomes larger. The bias caused by RTM is typically greatest for the extreme values of the data sets, emphasizing the need to account for RTM bias when comparing and interpreting these cases.

  13. Information filtering via biased heat conduction

    CERN Document Server

    Liu, Jian-Guo; Guo, Qiang

    2011-01-01

    Heat conduction process has recently found its application in personalized recommendation [T. Zhou \\emph{et al.}, PNAS 107, 4511 (2010)], which is of high diversity but low accuracy. By decreasing the temperatures of small-degree objects, we present an improved algorithm, called biased heat conduction (BHC), which could simultaneously enhance the accuracy and diversity. Extensive experimental analyses demonstrate that the accuracy on MovieLens, Netflix and Delicious datasets could be improved by 43.5%, 55.4% and 19.2% compared with the standard heat conduction algorithm, and the diversity is also increased or approximately unchanged. Further statistical analyses suggest that the present algorithm could simultaneously identify users' mainstream and special tastes, resulting in better performance than the standard heat conduction algorithm. This work provides a creditable way for highly efficient information filtering.

  14. Information filtering via biased heat conduction

    Science.gov (United States)

    Liu, Jian-Guo; Zhou, Tao; Guo, Qiang

    2011-09-01

    The process of heat conduction has recently found application in personalized recommendation [Zhou , Proc. Natl. Acad. Sci. USA PNASA60027-842410.1073/pnas.1000488107107, 4511 (2010)], which is of high diversity but low accuracy. By decreasing the temperatures of small-degree objects, we present an improved algorithm, called biased heat conduction, which could simultaneously enhance the accuracy and diversity. Extensive experimental analyses demonstrate that the accuracy on MovieLens, Netflix, and Delicious datasets could be improved by 43.5%, 55.4% and 19.2%, respectively, compared with the standard heat conduction algorithm and also the diversity is increased or approximately unchanged. Further statistical analyses suggest that the present algorithm could simultaneously identify users' mainstream and special tastes, resulting in better performance than the standard heat conduction algorithm. This work provides a creditable way for highly efficient information filtering.

  15. Fragment formation in biased random walks

    Science.gov (United States)

    Ramola, Kabir

    2008-10-01

    We analyse a biased random walk on a 1D lattice with unequal step lengths. Such a walk was recently shown to undergo a phase transition from a state containing a single connected cluster of visited sites to one with several clusters of visited sites (fragments) separated by unvisited sites at a critical probability pc (Anteneodo and Morgado 2007 Phys. Rev. Lett. 99 180602). The behaviour of ρ(l), the probability of formation of fragments of length l, is analysed. An exact expression for the generating function of ρ(l) at the critical point is derived. We prove that the asymptotic behaviour is of the form \\rho (l) \\simeq 3/[l(\\log \\ l)^2] .

  16. Preferences, country bias, and international trade

    NARCIS (Netherlands)

    S. Roy (Santanu); J.M.A. Viaene (Jean-Marie)

    1998-01-01

    textabstractAnalyzes international trade where consumer preferences exhibit country bias. Why country biases arise; How trade can occur in the presence of country bias; Implication for the pattern of trade and specialization.

  17. Preferences, country bias, and international trade

    NARCIS (Netherlands)

    S. Roy (Santanu); J.M.A. Viaene (Jean-Marie)

    1998-01-01

    textabstractAnalyzes international trade where consumer preferences exhibit country bias. Why country biases arise; How trade can occur in the presence of country bias; Implication for the pattern of trade and specialization.

  18. The North Atlantic Cold Bias

    Science.gov (United States)

    Greatbatch, Richard; Drews, Annika; Ding, Hui; Latif, Mojib; Park, Wonsun

    2016-04-01

    The North Atlantic cold bias, associated with a too zonal path of the North Atlantic Current and a missing "northwest corner", is a common problem in coupled climate and forecast models. The bias affects the North Atlantic and European climate mean state, variability and predictability. We investigate the use of a flow field correction to adjust the path of the North Atlantic Current as well as additional corrections to the surface heat and freshwater fluxes. Results using the Kiel Climate Model show that the flow field correction allows a northward flow into the northwest corner, largely eliminating the bias below the surface layer. A surface cold bias remains but can be eliminated by additionally correcting the surface freshwater flux, without adjusting the surface heat flux seen by the ocean model. A model version in which only the surface fluxes of heat and freshwater are corrected continues to exhibit the incorrect path of the North Atlantic Current and a strong subsurface bias. Removing the bias impacts the multi-decadal time scale variability in the model and leads to a better representation of the SST pattern associated with the Atlantic Multidecadal Variability than the uncorrected model.

  19. Recent advances in precipitation-bias correction and application

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Significant progresses have been made in recent years in precipitation data analyses at regional to global scales. This paper re-views and synthesizes recent advances in precipitation-bias corrections and applications in many countries and over the cold re-gions. The main objective of this review is to identify and examine gaps in regional and national precipitation-error analyses. This paper also discusses and recommends future research needs and directions. More effort and coordination are necessary in the determinations of precipitation biases on large regions across national borders. It is important to emphasize that bias cor-rections of precipitation measurements affect both water budget and energy balance calculations, particularly over the cold regions.

  20. The estimation method of GPS instrumental biases

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A model of estimating the global positioning system (GPS) instrumental biases and the methods to calculate the relative instrumental biases of satellite and receiver are presented. The calculated results of GPS instrumental biases, the relative instrumental biases of satellite and receiver, and total electron content (TEC) are also shown. Finally, the stability of GPS instrumental biases as well as that of satellite and receiver instrumental biases are evaluated, indicating that they are very stable during a period of two months and a half.

  1. Publicity and public relations

    Science.gov (United States)

    Fosha, Charles E.

    1990-01-01

    This paper addresses approaches to using publicity and public relations to meet the goals of the NASA Space Grant College. Methods universities and colleges can use to publicize space activities are presented.

  2. Trial Registration: Understanding and Preventing Reporting Bias in Social Work Research

    Science.gov (United States)

    Harrison, Bronwyn A.; Mayo-Wilson, Evan

    2014-01-01

    Randomized controlled trials are considered the gold standard for evaluating social work interventions. However, published reports can systematically overestimate intervention effects when researchers selectively report large and significant findings. Publication bias and other types of reporting biases can be minimized through prospective trial…

  3. Reporting bias in medical research - a narrative review

    Directory of Open Access Journals (Sweden)

    Kölsch Heike

    2010-04-01

    Full Text Available Abstract Reporting bias represents a major problem in the assessment of health care interventions. Several prominent cases have been described in the literature, for example, in the reporting of trials of antidepressants, Class I anti-arrhythmic drugs, and selective COX-2 inhibitors. The aim of this narrative review is to gain an overview of reporting bias in the medical literature, focussing on publication bias and selective outcome reporting. We explore whether these types of bias have been shown in areas beyond the well-known cases noted above, in order to gain an impression of how widespread the problem is. For this purpose, we screened relevant articles on reporting bias that had previously been obtained by the German Institute for Quality and Efficiency in Health Care in the context of its health technology assessment reports and other research work, together with the reference lists of these articles. We identified reporting bias in 40 indications comprising around 50 different pharmacological, surgical (e.g. vacuum-assisted closure therapy, diagnostic (e.g. ultrasound, and preventive (e.g. cancer vaccines interventions. Regarding pharmacological interventions, cases of reporting bias were, for example, identified in the treatment of the following conditions: depression, bipolar disorder, schizophrenia, anxiety disorder, attention-deficit hyperactivity disorder, Alzheimer's disease, pain, migraine, cardiovascular disease, gastric ulcers, irritable bowel syndrome, urinary incontinence, atopic dermatitis, diabetes mellitus type 2, hypercholesterolaemia, thyroid disorders, menopausal symptoms, various types of cancer (e.g. ovarian cancer and melanoma, various types of infections (e.g. HIV, influenza and Hepatitis B, and acute trauma. Many cases involved the withholding of study data by manufacturers and regulatory agencies or the active attempt by manufacturers to suppress publication. The ascertained effects of reporting bias included the

  4. Deadly Attraction - Attentional Bias toward Preferred Cigarette Brand in Smokers.

    Science.gov (United States)

    Domaradzka, Ewa; Bielecki, Maksymilian

    2017-01-01

    Numerous studies have shown that biases in visual attention might be evoked by affective and personally relevant stimuli, for example addiction-related objects. Despite the fact that addiction is often linked to specific products and systematic purchase behaviors, no studies focused directly on the existence of bias evoked by brands. Smokers are characterized by high levels of brand loyalty and everyday contact with cigarette packaging. Using the incentive-salience mechanism as a theoretical framework, we hypothesized that this group might exhibit a bias toward the preferred cigarette brand. In our study, a group of smokers (N = 40) performed a dot probe task while their eye movements were recorded. In every trial a pair of pictures was presented - each of them showed a single cigarette pack. The visual properties of stimuli were carefully controlled, so branding information was the key factor affecting subjects' reactions. For each participant, we compared gaze behavior related to the preferred vs. other brands. The analyses revealed no attentional bias in the early, orienting phase of the stimulus processing and strong differences in maintenance and disengagement. Participants spent more time looking at the preferred cigarettes and saccades starting at the preferred brand location had longer latencies. In sum, our data shows that attentional bias toward brands might be found in situations not involving choice or decision making. These results provide important insights into the mechanisms of formation and maintenance of attentional biases to stimuli of personal relevance and might serve as a first step toward developing new attitude measurement techniques.

  5. Media coverage of climate change in Russia: governmental bias and climate silence.

    Science.gov (United States)

    Poberezhskaya, Marianna

    2015-01-01

    This paper explores which actors and factors influence media coverage of climate change in Russia. It does this by analysing the coverage of three events by five Russian national newspapers (Komsomol'skaya pravda, Rossiyskaya gazeta, Izvestiya, Kommersant and Sovetskaya Rossiya). The three events are the Kyoto Conference in 1997, the Copenhagen Conference in 2009 and the Russian heat-wave of 2010. This paper concludes that regardless of the ownership structure of the newspapers or their dependence on advertising, there is little difference in quantity and quality of overall coverage on climate change. With most newspapers relying on Russian officials as information sources, almost none criticise or question Russian climate policy. Furthermore, the article concludes that, in Russia, the omission of climate change issues from discussion in national newspapers becomes a greater problem than biased coverage, as the lack of commentary decidedly prevents these issues from entering the public debate. © The Author(s) 2014.

  6. Traditional difference-score analyses of reasoning are flawed.

    Science.gov (United States)

    Heit, Evan; Rotello, Caren M

    2014-04-01

    Studies of the belief bias effect in syllogistic reasoning have relied on three traditional difference score measures: the logic index, belief index, and interaction index. Dube, Rotello, and Heit (2010, 2011) argued that the interaction index incorrectly assumes a linear receiver operating characteristic (ROC). Here, all three measures are addressed. Simulations indicated that traditional analyses of reasoning experiments are likely to lead to incorrect conclusions. Two new experiments examined the role of instructional manipulations on the belief bias effect. The form of the ROCs violated assumptions of traditional measures. In comparison, signal detection theory (SDT) model-based analyses were a better match for the form of the ROCs, and implied that belief bias and instructional manipulations are predominantly response bias effects. Finally, reanalyses of previous studies of conditional reasoning also showed non-linear ROCs, violating assumptions of traditional analyses. Overall, reasoning research using traditional measures is at risk of drawing incorrect conclusions.

  7. Gender bias in academic recruitment

    DEFF Research Database (Denmark)

    Abramo, Giovanni; D’Angelo, Ciriaco Andrea; Rosati, Francesco

    2016-01-01

    It is well known that women are underrepresented in the academic systems of many countries. Gender discrimination is one of the factors that could contribute to this phenomenon. This study considers a recent national academic recruitment campaign in Italy, examining whether women are subject...... to more or less bias than men. The findings show that no gender-related differences occur among the candidates who benefit from positive bias, while among those candidates affected by negative bias, the incidence of women is lower than that of men. Among the factors that determine success in a competition...... for an academic position, the number of the applicant’s career years in the same university as the committee members assumes greater weight for male candidates than for females. Being of the same gender as the committee president is also a factor that assumes greater weight for male applicants. On the other hand...

  8. Anchoring Bias in Online Voting

    CERN Document Server

    Yang, Zimo; Zhou, Tao

    2012-01-01

    Voting online with explicit ratings could largely reflect people's preferences and objects' qualities, but ratings are always irrational, because they may be affected by many unpredictable factors like mood, weather, as well as other people's votes. By analyzing two real systems, this paper reveals a systematic bias embedding in the individual decision-making processes, namely people tend to give a low rating after a low rating, as well as a high rating following a high rating. This so-called \\emph{anchoring bias} is validated via extensive comparisons with null models, and numerically speaking, the extent of bias decays with interval voting number in a logarithmic form. Our findings could be applied in the design of recommender systems and considered as important complementary materials to previous knowledge about anchoring effects on financial trades, performance judgements, auctions, and so on.

  9. Without Bias: A Guidebook for Nondiscriminatory Communication.

    Science.gov (United States)

    Pickens, Judy E., Ed.; And Others

    This guidebook discusses ways to eliminate various types of discrimination from business communications. Separately authored chapters discuss eliminating racial and ethnic bias; eliminating sexual bias; achieving communication sensitive about handicaps of disabled persons; eliminating bias from visual media; eliminating bias from meetings,…

  10. The Truth and Bias Model of Judgment

    Science.gov (United States)

    West, Tessa V.; Kenny, David A.

    2011-01-01

    We present a new model for the general study of how the truth and biases affect human judgment. In the truth and bias model, judgments about the world are pulled by 2 primary forces, the truth force and the bias force, and these 2 forces are interrelated. The truth and bias model differentiates force and value, where the force is the strength of…

  11. The Truth and Bias Model of Judgment

    Science.gov (United States)

    West, Tessa V.; Kenny, David A.

    2011-01-01

    We present a new model for the general study of how the truth and biases affect human judgment. In the truth and bias model, judgments about the world are pulled by 2 primary forces, the truth force and the bias force, and these 2 forces are interrelated. The truth and bias model differentiates force and value, where the force is the strength of…

  12. Measurement Bias Detection through Factor Analysis

    Science.gov (United States)

    Barendse, M. T.; Oort, F. J.; Werner, C. S.; Ligtvoet, R.; Schermelleh-Engel, K.

    2012-01-01

    Measurement bias is defined as a violation of measurement invariance, which can be investigated through multigroup factor analysis (MGFA), by testing across-group differences in intercepts (uniform bias) and factor loadings (nonuniform bias). Restricted factor analysis (RFA) can also be used to detect measurement bias. To also enable nonuniform…

  13. To what extent does human capital increase the home country bias?

    NARCIS (Netherlands)

    Boonstra, Bernard; Sterken, Elmer

    2001-01-01

    Abstract This paper analyses the role of human capital as a hedge against future unexpected changes in consumption of nontradable goods. We show, in line with Baxter-Jermann (1997) that human capital aggra- vates the home country bias, although we a lower increase of the bias based on an empirical a

  14. Codon Pair Bias Is a Direct Consequence of Dinucleotide Bias

    Directory of Open Access Journals (Sweden)

    Dusan Kunec

    2016-01-01

    Full Text Available Codon pair bias is a remarkably stable characteristic of a species. Although functionally uncharacterized, robust virus attenuation was achieved by recoding of viral proteins using underrepresented codon pairs. Because viruses replicate exclusively inside living cells, we posited that their codon pair preferences reflect those of their host(s. Analysis of many human viruses showed, however, that the encoding of viruses is influenced only marginally by host codon pair preferences. Furthermore, examination of codon pair preferences of vertebrate, insect, and arthropod-borne viruses revealed that the latter do not utilize codon pairs overrepresented in arthropods more frequently than other viruses. We found, however, that codon pair bias is a direct consequence of dinucleotide bias. We conclude that codon pair bias does not play a major role in the encoding of viral proteins and that virus attenuation by codon pair deoptimization has the same molecular underpinnings as attenuation based on an increase in CpG/TpA dinucleotides.

  15. The Threshold of Embedded M Collider Bias and Confounding Bias

    Science.gov (United States)

    Kelcey, Benjamin; Carlisle, Joanne

    2011-01-01

    Of particular import to this study, is collider bias originating from stratification on retreatment variables forming an embedded M or bowtie structural design. That is, rather than assume an M structural design which suggests that "X" is a collider but not a confounder, the authors adopt what they consider to be a more reasonable…

  16. Sex bias in infectious disease epidemiology: patterns and processes.

    Directory of Open Access Journals (Sweden)

    Felipe Guerra-Silveira

    Full Text Available BACKGROUND: Infectious disease incidence is often male-biased. Two main hypotheses have been proposed to explain this observation. The physiological hypothesis (PH emphasizes differences in sex hormones and genetic architecture, while the behavioral hypothesis (BH stresses gender-related differences in exposure. Surprisingly, the population-level predictions of these hypotheses are yet to be thoroughly tested in humans. METHODS AND FINDINGS: For ten major pathogens, we tested PH and BH predictions about incidence and exposure-prevalence patterns. Compulsory-notification records (Brazil, 2006-2009 were used to estimate age-stratified ♂:♀ incidence rate ratios for the general population and across selected sociological contrasts. Exposure-prevalence odds ratios were derived from 82 published surveys. We estimated summary effect-size measures using random-effects models; our analyses encompass ∼0.5 million cases of disease or exposure. We found that, after puberty, disease incidence is male-biased in cutaneous and visceral leishmaniasis, schistosomiasis, pulmonary tuberculosis, leptospirosis, meningococcal meningitis, and hepatitis A. Severe dengue is female-biased, and no clear pattern is evident for typhoid fever. In leprosy, milder tuberculoid forms are female-biased, whereas more severe lepromatous forms are male-biased. For most diseases, male bias emerges also during infancy, when behavior is unbiased but sex steroid levels transiently rise. Behavioral factors likely modulate male-female differences in some diseases (the leishmaniases, tuberculosis, leptospirosis, or schistosomiasis and age classes; however, average exposure-prevalence is significantly sex-biased only for Schistosoma and Leptospira. CONCLUSIONS: Our results closely match some key PH predictions and contradict some crucial BH predictions, suggesting that gender-specific behavior plays an overall secondary role in generating sex bias. Physiological differences, including

  17. Attention Bias Modification for Major Depressive Disorder: Effects on Attention Bias, Resting State Connectivity, and Symptom Change

    Science.gov (United States)

    Beevers, Christopher G.; Clasen, Peter C.; Enock, Philip M.; Schnyer, David M.

    2015-01-01

    Cognitive theories of depression posit that selective attention for negative information contributes to the maintenance of depression. The current study experimentally tested this idea by randomly assigning adults with Major Depressive Disorder (MDD) to four weeks of computer-based attention bias modification designed to reduce negative attention bias or four weeks of placebo attention training. Findings indicate that compared to placebo training, attention bias modification reduced negative attention bias and increased resting-state connectivity within a neural circuit (i.e., middle frontal gyrus and dorsal anterior cingulate cortex) that supports control over emotional information. Further, pre- to post-training change in negative attention bias was significantly correlated with depression symptom change only in the active training condition. Exploratory analyses indicated that pre- to post-training changes in resting state connectivity within a circuit associated with sustained attention to visual information (i.e., precuenus and middle frontal gyrus) contributed to symptom improvement in the placebo condition. Importantly, depression symptoms did not change differentially between the training groups—overall, a 40% decrease in symptoms was observed across attention training conditions. Findings suggest that negative attention bias is associated with the maintenance of depression; however, general attentional control may also maintain depression symptoms, as evidenced by resting state connectivity and depression symptom improvement in the placebo training condition. PMID:25894440

  18. The anterior bias in visual art: the case of images of animals.

    Science.gov (United States)

    Bertamini, Marco; Bennett, Kate M; Bode, Carole

    2011-11-01

    Composition is an important topic in visual art. The literature suggests a bias for objects on the right side (Levy, 1976) and two additional biases with respect to positioning of objects within a rectangular frame: a Centre bias and an Inward bias (Palmer, Gardner, & Wickens, 2008). We analysed images of animals from three datasets of works of art: two datasets were from artists well known for their portraits of animals (Bewick, Stubbs) and the third was a medieval bestiary. There was no overall displacement of the subject to the right or to the left of the picture. However, we found a bias consisting of more space in front compared to behind the animal, consistent with Palmer at al.'s findings and with their definition of an Inward bias. Because our animals never face towards the centre we use the term Anterior bias. In addition, we found a modulation of this bias on the basis of the facing direction of the animal, consisting of a stronger Anterior bias for left-facing animals. This asymmetry may originate from a combination of an Anterior bias and a Right bias. Finally, with respect to size we found that the size of the animals predicted the proportion of the picture occupied, an effect known as "canonical size".

  19. Bias During the Evaluation of Animal Studies?

    Directory of Open Access Journals (Sweden)

    Andrew Knight

    2012-02-01

    Full Text Available My recent book entitled The Costs and Benefits of Animal Experiments seeks to answer a key question within animal ethics, namely: is animal experimentation ethically justifiable? Or, more precisely, is it justifiable within the utilitarian cost:benefit framework that fundamentally underpins most regulations governing animal experimentation? To answer this question I reviewed more than 500 scientific publications describing animal studies, animal welfare impacts, and alternative research, toxicity testing and educational methodologies. To minimise bias I focused primarily on large-scale systematic reviews that had examined the human clinical and toxicological utility of animal studies. Despite this, Dr. Susanne Prankel recently reviewed my book in this journal, essentially accusing me of bias. However, she failed to provide any substantive evidence to refute my conclusions, let alone evidence of similar weight to that on which they are based. Those conclusions are, in fact, firmly based on utilitarian ethical reasoning, informed by scientific evidence of considerable strength, and I believe they are robust.

  20. Can decision biases improve insurance outcomes? An experiment on status quo bias in health insurance choice.

    Science.gov (United States)

    Krieger, Miriam; Felder, Stefan

    2013-06-19

    Rather than conforming to the assumption of perfect rationality in neoclassical economic theory, decision behavior has been shown to display a host of systematic biases. Properly understood, these patterns can be instrumentalized to improve outcomes in the public realm. We conducted a laboratory experiment to study whether decisions over health insurance policies are subject to status quo bias and, if so, whether experience mitigates this framing effect. Choices in two treatment groups with status quo defaults are compared to choices in a neutrally framed control group. A two-step design features sorting of subjects into the groups, allowing us to control for selection effects due to risk preferences. The results confirm the presence of a status quo bias in consumer choices over health insurance policies. However, this effect of the default framing does not persist as subjects repeat this decision in later periods of the experiment. Our results have implications for health care policy, for example suggesting that the use of non-binding defaults in health insurance can facilitate the spread of co-insurance policies and thereby help contain health care expenditure.

  1. Bias in Dynamic Monte Carlo Alpha Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Sweezy, Jeremy Ed [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nolen, Steven Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Adams, Terry R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trahan, Travis John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-06

    A 1/N bias in the estimate of the neutron time-constant (commonly denoted as α) has been seen in dynamic neutronic calculations performed with MCATK. In this paper we show that the bias is most likely caused by taking the logarithm of a stochastic quantity. We also investigate the known bias due to the particle population control method used in MCATK. We conclude that this bias due to the particle population control method is negligible compared to other sources of bias.

  2. Publication bias and the canonization of false facts

    DEFF Research Database (Denmark)

    Nissen, Silas Boye; Magidson, Tali; Gross, Kevin;

    2016-01-01

    canonized as fact. Data-dredging, p-hacking, and similar behaviors exacerbate the problem. Should negative results become easier to publish as a claim approaches acceptance as a fact, however, true and false claims would be more readily distinguished. To the degree that the model reflects the real world...

  3. Dominant Personality Types in Public Accounting: Selection Bias or Indoctrinated?

    Science.gov (United States)

    Burton, Hughlene; Daugherty, Brian; Dickins, Denise; Schisler, Dan

    2016-01-01

    Prior studies concerning the personality type and preferences of accountants generally draw conclusions based upon the reports of either practicing accountants, or accounting students, at a single point in time. So while much is known about the personality type of accountants in general, left unexplored is the question of whether public…

  4. Publication bias- a reason for the decreased research output in ...

    African Journals Online (AJOL)

    Adele

    countries in high impact psychiatric journals.1 Some of the ... of manpower, funding, scientific knowledge and skill in ... Department of Psychiatry, Nelson R Mandela School of Medicine, University of Kwa-Zulu Natal, Durban, South ... become more innovative and include the changing paradigm in epidemiological research.

  5. Publication bias and the canonization of false facts

    DEFF Research Database (Denmark)

    Nissen, Silas Boye; Magidson, Tali; Gross, Kevin

    2016-01-01

    Science is facing a "replication crisis" in which many experimental findings cannot be replicated and are likely to be false. Does this imply that many scientific facts are false as well? To find out, we explore the process by which a claim becomes fact. We model the community's confidence...

  6. Ratio Bias and Policy Preferences

    DEFF Research Database (Denmark)

    Pedersen, Rasmus Tue

    2016-01-01

    Numbers permeate modern political communication. While current scholarship on framing effects has focused on the persuasive effects of words and arguments, this article shows that framing of numbers can also substantially affect policy preferences. Such effects are caused by ratio bias, which is ...

  7. Perception bias in route choice

    NARCIS (Netherlands)

    Vreeswijk, Jacob Dirk; Thomas, Tom; van Berkum, Eric C.; van Arem, Bart

    2014-01-01

    Travel time is probably one of the most studied attributes in route choice. Recently, perception of travel time received more attention as several studies have shown its importance in explaining route choice behavior. In particular, travel time estimates by travelers appear to be biased against

  8. Perception bias in route choice

    NARCIS (Netherlands)

    Vreeswijk, Jacob Dirk; Thomas, Tom; van Berkum, Eric C.; van Arem, Bart

    2014-01-01

    Travel time is probably one of the most studied attributes in route choice. Recently, perception of travel time received more attention as several studies have shown its importance in explaining route choice behavior. In particular, travel time estimates by travelers appear to be biased against non-

  9. Attentional bias in math anxiety

    Science.gov (United States)

    Rubinsten, Orly; Eidlin, Hili; Wohl, Hadas; Akibli, Orly

    2015-01-01

    Cognitive theory from the field of general anxiety suggests that the tendency to display attentional bias toward negative information results in anxiety. Accordingly, the current study aims to investigate whether attentional bias is involved in math anxiety (MA) as well (i.e., a persistent negative reaction to math). Twenty seven participants (14 with high levels of MA and 13 with low levels of MA) were presented with a novel computerized numerical version of the well established dot probe task. One of six types of prime stimuli, either math related or typically neutral, was presented on one side of a computer screen. The prime was preceded by a probe (either one or two asterisks) that appeared in either the prime or the opposite location. Participants had to discriminate probe identity (one or two asterisks). Math anxious individuals reacted faster when the probe was at the location of the numerical related stimuli. This suggests the existence of attentional bias in MA. That is, for math anxious individuals, the cognitive system selectively favored the processing of emotionally negative information (i.e., math related words). These findings suggest that attentional bias is linked to unduly intense MA symptoms. PMID:26528208

  10. Attentional Bias in Math Anxiety

    Directory of Open Access Journals (Sweden)

    Orly eRubinsten

    2015-10-01

    Full Text Available Cognitive theory from the field of general anxiety suggests that the tendency to display attentional bias toward negative information results in anxiety. Accordingly, the current study aims to investigate whether attentional bias is involved in math anxiety as well (i.e., a persistent negative reaction to math. Twenty seven participants (14 with high levels of math anxiety and 13 with low levels of math anxiety were presented with a novel computerized numerical version of the well established dot probe task. One of 6 types of prime stimuli, either math related or typically neutral, were presented on one side of a computer screen. The prime was preceded by a probe (either one or two asterisks that appeared in either the prime or the opposite location. Participants had to discriminate probe identity (one or two asterisks. Math anxious individuals reacted faster when the probe was at the location of the numerical related stimuli. This suggests the existence of attentional bias in math anxiety. That is, for math anxious individuals, the cognitive system selectively favored the processing of emotionally negative information (i.e., math related words. These findings suggest that attentional bias is linked to unduly intense math anxiety symptoms.

  11. Stereotype Formation : Biased by Association

    NARCIS (Netherlands)

    Le Pelley, Mike E.; Reimers, Stian J.; Calvini, Guglielmo; Spears, Russell; Beesley, Tom; Murphy, Robin A.

    2010-01-01

    We propose that biases in attitude and stereotype formation might arise as a result of learned differences ill the extent its which social groups have previously been predictive elf behavioral or physical properties Experiments 1 and 2 demonstrate that differences in the experienced predictiveness o

  12. Sex Bias in Counseling Materials

    Science.gov (United States)

    Harway, Michele

    1977-01-01

    This article reviews findings of bias in counseling materials and presents results of three original studies. Indications are that textbooks used by practitioners present the sexes in stereotypical fashion, and a greater proportion of college catalog context is devoted to men than to women. (Author)

  13. Perception bias in route choice

    NARCIS (Netherlands)

    Vreeswijk, J.D.; Thomas, T.; Berkum, van E.C.; Arem, van B.

    2014-01-01

    Travel time is probably one of the most studied attributes in route choice. Recently, perception of travel time received more attention as several studies have shown its importance in explaining route choice behavior. In particular, travel time estimates by travelers appear to be biased against non-

  14. Measurement Bias in Multilevel Data

    NARCIS (Netherlands)

    Jak, Suzanne; Oort, Frans J.; Dolan, Conor V.

    2014-01-01

    Measurement bias can be detected using structural equation modeling (SEM), by testing measurement invariance with multigroup factor analysis (Jöreskog, 1971;Meredith, 1993;Sörbom, 1974) MIMIC modeling (Muthén, 1989) or restricted factor analysis (Oort, 1992,1998). In educational research, data often

  15. Measurement bias in multilevel data

    NARCIS (Netherlands)

    Jak, S.; Oort, F.J.; Dolan, C.V.

    2014-01-01

    Measurement bias can be detected using structural equation modeling (SEM), by testing measurement invariance with multigroup factor analysis (Jöreskog, 1971;Meredith, 1993;Sörbom, 1974) MIMIC modeling (Muthén, 1989) or restricted factor analysis (Oort, 1992,1998). In educational research, data often

  16. Attentional bias in math anxiety.

    Science.gov (United States)

    Rubinsten, Orly; Eidlin, Hili; Wohl, Hadas; Akibli, Orly

    2015-01-01

    Cognitive theory from the field of general anxiety suggests that the tendency to display attentional bias toward negative information results in anxiety. Accordingly, the current study aims to investigate whether attentional bias is involved in math anxiety (MA) as well (i.e., a persistent negative reaction to math). Twenty seven participants (14 with high levels of MA and 13 with low levels of MA) were presented with a novel computerized numerical version of the well established dot probe task. One of six types of prime stimuli, either math related or typically neutral, was presented on one side of a computer screen. The prime was preceded by a probe (either one or two asterisks) that appeared in either the prime or the opposite location. Participants had to discriminate probe identity (one or two asterisks). Math anxious individuals reacted faster when the probe was at the location of the numerical related stimuli. This suggests the existence of attentional bias in MA. That is, for math anxious individuals, the cognitive system selectively favored the processing of emotionally negative information (i.e., math related words). These findings suggest that attentional bias is linked to unduly intense MA symptoms.

  17. Selection bias in the reported performances of AD classification pipelines.

    Science.gov (United States)

    Mendelson, Alex F; Zuluaga, Maria A; Lorenzi, Marco; Hutton, Brian F; Ourselin, Sébastien

    2017-01-01

    The last decade has seen a great proliferation of supervised learning pipelines for individual diagnosis and prognosis in Alzheimer's disease. As more pipelines are developed and evaluated in the search for greater performance, only those results that are relatively impressive will be selected for publication. We present an empirical study to evaluate the potential for optimistic bias in classification performance results as a result of this selection. This is achieved using a novel, resampling-based experiment design that effectively simulates the optimisation of pipeline specifications by individuals or collectives of researchers using cross validation with limited data. Our findings indicate that bias can plausibly account for an appreciable fraction (often greater than half) of the apparent performance improvement associated with the pipeline optimisation, particularly in small samples. We discuss the consistency of our findings with patterns observed in the literature and consider strategies for bias reduction and mitigation.

  18. Biased selection within the social health insurance market in Colombia.

    Science.gov (United States)

    Castano, Ramon; Zambrano, Andres

    2006-12-01

    Reducing the impact of insurance market failures with regulations such as community-rated premiums, standardized benefit packages and open enrolment, yield limited effect because they create room for selection bias. The Colombian social health insurance system started a market approach in 1993 expecting to improve performance of preexisting monopolistic insurance funds by exposing them to competition by new entrants. This paper tests the hypothesis that market failures would lead to biased selection favoring new entrants. Two household surveys are analyzed using Self-Reported Health Status and the presence of chronic conditions as prospective indicators of individual risk. Biased selection is found to take place, leading to adverse selection among incumbents, and favorable selection among new entrants. This pattern is absent in 1997 but is evident in 2003. Given that the two incumbents analyzed are public organizations, the fiscal implications of the findings in terms of government bailouts, are analyzed.

  19. Biased sampling, over-identified parameter problems and beyond

    CERN Document Server

    Qin, Jing

    2017-01-01

    This book is devoted to biased sampling problems (also called choice-based sampling in Econometrics parlance) and over-identified parameter estimation problems. Biased sampling problems appear in many areas of research, including Medicine, Epidemiology and Public Health, the Social Sciences and Economics. The book addresses a range of important topics, including case and control studies, causal inference, missing data problems, meta-analysis, renewal process and length biased sampling problems, capture and recapture problems, case cohort studies, exponential tilting genetic mixture models etc. The goal of this book is to make it easier for Ph. D students and new researchers to get started in this research area. It will be of interest to all those who work in the health, biological, social and physical sciences, as well as those who are interested in survey methodology and other areas of statistical science, among others. .

  20. Recommendations for individual participant data meta-analyses on work stressors and health outcomes: comments on IPD-Work Consortium papers.

    Science.gov (United States)

    Choi, Bong Kyoo; Schnall, Peter; Landsbergis, Paul; Dobson, Marnie; Ko, Sangbaek; Gómez-Ortiz, Viviola; Juárez-Garcia, Arturo; Baker, Dean

    2015-05-01

    The IPD-Work (individual-participant data meta-analysis of working populations) Consortium has published several papers on job strain (the combination of low job control and high job demands) based on Karasek's demand-control model (1) and health-related outcomes including cardiovascular disease (CVD), cancer, obesity, diabetes as well as health-related behaviors, utilizing meta-analyses of a pooled database of study participants from 17 European cohorts. An IPD approach has some advantages over typical meta-analyses, eg, having access to all the data for each individual allows for additional analyses, compared to typical meta-analyses. However, such an approach, like other meta-analyses, is not free from errors and biases (2-6) when it is not conducted appropriately. In our review of the IPD-Work Consortium's (hereafter called the Consortium) publications of the last two years, we have identified and pointed out several conceptual and methodological errors, as well as unsubstantiated conclusions and inappropriate recommendations for worksite public health policies (6-15). However, the Consortium has not yet appropriately addressed many of the issues we have raised. Also several major errors and biases underlying the Consortium IPD meta-analysis publications have not been presented in a comprehensive way, nor have they been discussed widely among work stress researchers. We are concerned that the same errors and biases could be repeated in future IPD Consortium meta-analysis publications as well as by other researchers who are interested in meta-analyses on work stressors and health outcomes. It is possible that the inappropriate interpretations in the Consortium publications, which remained uncorrected to date, may have a negative impact on the international efforts of the work stress research community to improve the health of working populations. Recently, Dr. Töres Theorell, a principal investigator of the Consortium, responded in this journal (16) to some of

  1. A Systematic Review of Meta-Analyses on Gene Polymorphisms and Gastric Cancer Risk

    Science.gov (United States)

    Gianfagna, Francesco; De Feo, Emma; van Duijn, Cornelia M; Ricciardi, Gualtiero; Boccia, Stefania

    2008-01-01

    Background Individual variations in gastric cancer risk have been associated in the last decade with specific variant alleles of different genes that are present in a significant proportion of the population. Polymorphisms may modify the effects of environmental exposures, and these gene-environment interactions could partly explain the high variation of gastric cancer incidence around the world. The aim of this report is to carry out a systematic review of the published meta-analyses of studies investigating the association between gene polymorphisms and gastric cancer risk, and describe their impact at population level. Priorities on the design of further primary studies are then provided. Methods A structured bibliographic search on Medline and EMBASE databases has been performed to identify meta-analyses on genetic susceptibility to gastric cancer, without restriction criteria. We report the main results of the meta-analyses and we describe the subgroup analyses performed, focusing on the detection of statistical heterogeneity. We investigated publication bias by pooling the primary studies included in the meta-analyses, and we computed the population attributable risk (PAR) for each polymorphism. Results Twelve meta-analyses and one pooled-analysis of community based genetic association studies were included, focusing on nine genes involved in inflammation (IL-1β, IL-1RN, IL-8), detoxification of carcinogens (GSTs, CYP2E1), folate metabolism (MTHFR), intercellular adhesion (E-cadherin) and cell cycle regulation (p53). According to their random-Odds Ratios, individuals carrying one of the IL-1RN *2, IL-1β -511T variant alleles or homozygotes for MTHFR 677T are significantly at higher risk of gastric cancer than those with the wild type homozygote genotypes, showing high PARs. The main sources of heterogeneity in the meta-analyses were ethnicity, quality of the primary study, and selected environmental co-exposures. Effect modification by Helicobacter pylori

  2. Bias Adjusted Precipitation Threat Scores

    Directory of Open Access Journals (Sweden)

    F. Mesinger

    2008-04-01

    Full Text Available Among the wide variety of performance measures available for the assessment of skill of deterministic precipitation forecasts, the equitable threat score (ETS might well be the one used most frequently. It is typically used in conjunction with the bias score. However, apart from its mathematical definition the meaning of the ETS is not clear. It has been pointed out (Mason, 1989; Hamill, 1999 that forecasts with a larger bias tend to have a higher ETS. Even so, the present author has not seen this having been accounted for in any of numerous papers that in recent years have used the ETS along with bias "as a measure of forecast accuracy".

    A method to adjust the threat score (TS or the ETS so as to arrive at their values that correspond to unit bias in order to show the model's or forecaster's accuracy in extit{placing} precipitation has been proposed earlier by the present author (Mesinger and Brill, the so-called dH/dF method. A serious deficiency however has since been noted with the dH/dF method in that the hypothetical function that it arrives at to interpolate or extrapolate the observed value of hits to unit bias can have values of hits greater than forecast when the forecast area tends to zero. Another method is proposed here based on the assumption that the increase in hits per unit increase in false alarms is proportional to the yet unhit area. This new method removes the deficiency of the dH/dF method. Examples of its performance for 12 months of forecasts by three NCEP operational models are given.

  3. Information environment, behavioral biases, and home bias in analysts’ recommendations

    DEFF Research Database (Denmark)

    Farooq, Omar; Taouss, Mohammed

    2012-01-01

    ’ recommendations. Using a large data of analysts’ recommendations from Asian emerging markets, we show that local analysts issue more optimistic recommendations than their foreign counterparts. However, optimism difference between the two groups is greater for firms with poor information environment. Our results......Can information environment of a firm explain home bias in analysts’ recommendations? Can the extent of agency problems explain optimism difference between foreign and local analysts? This paper answers these questions by documenting the effect of information environment on home bias in analysts...... show that optimism difference between the two groups is more than twice as much in firms with poor information environment than in firms with better information environment. We argue that poor information environment pose greater information asymmetries to foreign analysts regarding local firms...

  4. Motherhood: a potential source of bias in employment decisions.

    Science.gov (United States)

    Heilman, Madeline E; Okimoto, Tyler G

    2008-01-01

    Results of 2 experimental studies in which job incumbents were said to be applying for promotions to traditionally male positions demonstrated bias against mothers in competence expectations and in screening recommendations. This bias occurred regardless of whether the research participants were students (Study 1) or working people (Study 2). Although anticipated job commitment, achievement striving, and dependability were rated as generally lower for parents than for nonparents, anticipated competence was uniquely low for mothers. Mediational analyses indicated that, as predicted, negativity in competence expectations, not anticipated job commitment or achievement striving, promoted the motherhood bias in screening recommendations; expected deficits in agentic behaviors, not in dependability, were found to fuel these competence expectations. These findings suggest that motherhood can indeed hinder the career advancement of women and that it is the heightened association with gender stereotypes that occurs when women are mothers that is the source of motherhood's potentially adverse consequences. 2008 APA

  5. 'Journal Bias' in peer-reviewed literature: an analysis of the surgical high-grade glioma literature.

    Science.gov (United States)

    Hirshman, Brian R; Jones, Laurie A; Tang, Jessica A; Proudfoot, James A; Carley, Kathleen M; Carter, Bob S; Chen, Clark C

    2016-11-01

    The core premise of evidence-based medicine is that clinical decisions are informed by the peer-reviewed literature. To extract meaningful conclusions from this literature, one must first understand the various forms of biases inherent within the process of peer review. We performed an exhaustive search that identified articles exploring the question of whether survival benefit was associated with maximal high-grade glioma (HGG) resection and analysed this literature for patterns of publication. We found that the distribution of these 108 articles among the 26 journals to be non-random (p<0.01), with 75 of the 108 published articles (69%) appearing in 6 of the 26 journals (25%). Moreover, certain journals were likely to publish a large number of articles from the same medical academic genealogy (authors with shared training history and/or mentor). We term the tendency of certain types of articles to be published in select journals 'journal bias' and discuss the implication of this form of bias as it pertains to evidence-based medicine. 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/.

  6. Public Education, Public Good.

    Science.gov (United States)

    Tomlinson, John

    1986-01-01

    Criticizes policies which would damage or destroy a public education system. Examines the relationship between government-provided education and democracy. Concludes that privatization of public education would emphasize self-interest and selfishness, further jeopardizing the altruism and civic mindedness necessary for the public good. (JDH)

  7. Quality of evidence revealing subtle gender biases in science is in the eye of the beholder.

    Science.gov (United States)

    Handley, Ian M; Brown, Elizabeth R; Moss-Racusin, Corinne A; Smith, Jessi L

    2015-10-27

    Scientists are trained to evaluate and interpret evidence without bias or subjectivity. Thus, growing evidence revealing a gender bias against women-or favoring men-within science, technology, engineering, and mathematics (STEM) settings is provocative and raises questions about the extent to which gender bias may contribute to women's underrepresentation within STEM fields. To the extent that research illustrating gender bias in STEM is viewed as convincing, the culture of science can begin to address the bias. However, are men and women equally receptive to this type of experimental evidence? This question was tested with three randomized, double-blind experiments-two involving samples from the general public (n = 205 and 303, respectively) and one involving a sample of university STEM and non-STEM faculty (n = 205). In all experiments, participants read an actual journal abstract reporting gender bias in a STEM context (or an altered abstract reporting no gender bias in experiment 3) and evaluated the overall quality of the research. Results across experiments showed that men evaluate the gender-bias research less favorably than women, and, of concern, this gender difference was especially prominent among STEM faculty (experiment 2). These results suggest a relative reluctance among men, especially faculty men within STEM, to accept evidence of gender biases in STEM. This finding is problematic because broadening the participation of underrepresented people in STEM, including women, necessarily requires a widespread willingness (particularly by those in the majority) to acknowledge that bias exists before transformation is possible.

  8. Variation in the Correlation of G + C Composition with Synonymous Codon Usage Bias among Bacteria

    Directory of Open Access Journals (Sweden)

    Suzuki Haruo

    2007-01-01

    Full Text Available G + C composition at the third codon position (GC3 is widely reported to be correlated with synonymous codon usage bias. However, no quantitative attempt has been made to compare the extent of this correlation among different genomes. Here, we applied Shannon entropy from information theory to measure the degree of GC3 bias and that of synonymous codon usage bias of each gene. The strength of the correlation of GC3 with synonymous codon usage bias, quantified by a correlation coefficient, varied widely among bacterial genomes, ranging from 0.07 to 0.95. Previous analyses suggesting that the relationship between GC3 and synonymous codon usage bias is independent of species are thus inconsistent with the more detailed analyses obtained here for individual species.

  9. Variation in the Correlation of G + C Composition with Synonymous Codon Usage Bias among Bacteria

    Directory of Open Access Journals (Sweden)

    Haruo Suzuki

    2007-07-01

    Full Text Available G + C composition at the third codon position (GC3 is widely reported to be correlated with synonymous codon usage bias. However, no quantitative attempt has been made to compare the extent of this correlation among different genomes. Here, we applied Shannon entropy from information theory to measure the degree of GC3 bias and that of synonymous codon usage bias of each gene. The strength of the correlation of GC3 with synonymous codon usage bias, quantified by a correlation coefficient, varied widely among bacterial genomes, ranging from −0.07 to 0.95. Previous analyses suggesting that the relationship between GC3 and synonymous codon usage bias is independent of species are thus inconsistent with the more detailed analyses obtained here for individual species.

  10. Spatial uncertainty in bias corrected climate change projections and hydrogeological impacts

    DEFF Research Database (Denmark)

    Seaby, Lauren Paige; Refsgaard, Jens Christian; Sonnenborg, Torben

    2015-01-01

    The question of which climate model bias correction methods and spatial scales for correction are optimal for both projecting future hydrological changes as well as removing initial model bias has so far received little attention. For 11 climate models (CMs), or GCM/RCM – Global/Regional Climate...... Model pairing, this paper analyses the relationship between complexity and robustness of three distribution-based scaling (DBS) bias correction methods applied to daily precipitation at various spatial scales. Hydrological simulations are forced by CM inputs to assess the spatial uncertainty...... signals. The magnitude of spatial bias seen in precipitation inputs does not necessarily correspond to the magnitude of biases seen in hydrological outputs. Variables that integrate basin responses over time and space are more sensitive to mean spatial biases and less so on extremes. Hydrological...

  11. Types of Research Bias Encountered in IR.

    Science.gov (United States)

    Gabr, Ahmed; Kallini, Joseph Ralph; Desai, Kush; Hickey, Ryan; Thornburg, Bartley; Kulik, Laura; Lewandowski, Robert J; Salem, Riad

    2016-04-01

    Bias is a systemic error in studies that leads to inaccurate deductions. Relevant biases in the field of IR and interventional oncology were identified after reviewing articles published in the Journal of Vascular and Interventional Radiology and CardioVascular and Interventional Radiology. Biases cited in these articles were divided into three categories: preinterventional (health care access, participation, referral, and sample biases), periinterventional (contamination, investigator, and operator biases), and postinterventional (guarantee-time, lead time, loss to follow-up, recall, and reporting biases). Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

  12. Who Benefits from Public Social Spending in Chad? A Benefit Incidence Analysis (A qui profitent les dépenses sociales au Tchad? Une analyse d'incidence à partir des données d'enquête

    NARCIS (Netherlands)

    Djindil, N.S.; Tabo Symphorien, N.; Mogota Anatole, T.

    2007-01-01

    This study examines the impact of public expenditures in the sector of education and maternal and child health in household level in Chad. The results show that there exist a very strong social selectivity in the utilisation and transfer of health and education in Chad. The analysis reveals that an

  13. Bias Assessment of General Chemistry Analytes using Commutable Samples.

    Science.gov (United States)

    Koerbin, Gus; Tate, Jillian R; Ryan, Julie; Jones, Graham Rd; Sikaris, Ken A; Kanowski, David; Reed, Maxine; Gill, Janice; Koumantakis, George; Yen, Tina; St John, Andrew; Hickman, Peter E; Simpson, Aaron; Graham, Peter

    2014-11-01

    Harmonisation of reference intervals for routine general chemistry analytes has been a goal for many years. Analytical bias may prevent this harmonisation. To determine if analytical bias is present when comparing methods, the use of commutable samples, or samples that have the same properties as the clinical samples routinely analysed, should be used as reference samples to eliminate the possibility of matrix effect. The use of commutable samples has improved the identification of unacceptable analytical performance in the Netherlands and Spain. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has undertaken a pilot study using commutable samples in an attempt to determine not only country specific reference intervals but to make them comparable between countries. Australia and New Zealand, through the Australasian Association of Clinical Biochemists (AACB), have also undertaken an assessment of analytical bias using commutable samples and determined that of the 27 general chemistry analytes studied, 19 showed sufficiently small between method biases as to not prevent harmonisation of reference intervals. Application of evidence based approaches including the determination of analytical bias using commutable material is necessary when seeking to harmonise reference intervals.

  14. Diagnostic uncertainty and recall bias in chronic low back pain.

    Science.gov (United States)

    Serbic, Danijela; Pincus, Tamar

    2014-08-01

    Patients' beliefs about the origin of their pain and their cognitive processing of pain-related information have both been shown to be associated with poorer prognosis in low back pain (LBP), but the relationship between specific beliefs and specific cognitive processes is not known. The aim of this study was to examine the relationship between diagnostic uncertainty and recall bias in 2 groups of chronic LBP patients, those who were certain about their diagnosis and those who believed that their pain was due to an undiagnosed problem. Patients (N=68) endorsed and subsequently recalled pain, illness, depression, and neutral stimuli. They also provided measures of pain, diagnostic status, mood, and disability. Both groups exhibited a recall bias for pain stimuli, but only the group with diagnostic uncertainty also displayed a recall bias for illness-related stimuli. This bias remained after controlling for depression and disability. Sensitivity analyses using grouping by diagnosis/explanation received supported these findings. Higher levels of depression and disability were found in the group with diagnostic uncertainty, but levels of pain intensity did not differ between the groups. Although the methodology does not provide information on causality, the results provide evidence for a relationship between diagnostic uncertainty and recall bias for negative health-related stimuli in chronic LBP patients.

  15. 浅析健康教育电视公益广告创意表现原则%Health Education is Analysed Principle of Television Public Service ads Creative Performance

    Institute of Scientific and Technical Information of China (English)

    彭尧; 史景璐

    2015-01-01

    Compared to other mass communication way,film and television dissemination has the characteristics of vivid and intuitive,permeability is strong.And health education(TV)public welfare advertisement of claim object is one of the most widely,it is a kind of health for the social public information dissemination way.Public interest advertising is to serve the public,only to let the public spread from accepting to reach its goal.This article obtains from the perspective of the principle of performance,the main analysis to investigate the social,advocacy,scientific and artistic principles in the health education(TV) public welfare advertising creative,the application for health education in the future(TV)public service ads creative provide constructive Suggestions.%相比较其他大众传播途径,影视传播具有生动直观、渗透性强的特点.并且,健康教育(电视)公益广告的诉求对象是最广泛的,它是面向全体社会公众的一种健康信息传播方式.公益广告是为社会大众服务的,只有让大众从内心接受才能达到其传播目的.该文从表现原则角度入手,主要分析探讨社会性、倡导性、科学性和艺术性原则在健康教育(电视)公益广告创意中的运用,旨在为日后健康教育(电视)公益广告的创意提供建设性建议,充分发挥其覆盖面广、传播效率高的特点,丰富广告的创意,增加广告的魅力,使公益广告深入人心,普及健康素养基本知识与技能,倡导健康生活方式,营造良好的社会氛围.

  16. Probability biases as Bayesian inference

    Directory of Open Access Journals (Sweden)

    Andre; C. R. Martins

    2006-11-01

    Full Text Available In this article, I will show how several observed biases in human probabilistic reasoning can be partially explained as good heuristics for making inferences in an environment where probabilities have uncertainties associated to them. Previous results show that the weight functions and the observed violations of coalescing and stochastic dominance can be understood from a Bayesian point of view. We will review those results and see that Bayesian methods should also be used as part of the explanation behind other known biases. That means that, although the observed errors are still errors under the be understood as adaptations to the solution of real life problems. Heuristics that allow fast evaluations and mimic a Bayesian inference would be an evolutionary advantage, since they would give us an efficient way of making decisions. %XX In that sense, it should be no surprise that humans reason with % probability as it has been observed.

  17. Belief bias and relational reasoning.

    Science.gov (United States)

    Roberts, Maxwell J; Sykes, Elizabeth D A

    2003-01-01

    When people evaluate categorical syllogisms, they tend to reject unbelievable conclusions and accept believable ones irrespective of their validity. Typically, this effect is particularly marked for invalid conclusions that are possible, but do not necessarily follow, given the premises. However, smaller believability effects can also be detected for other types of conclusion. Three experiments are reported here, in which an attempt was made to determine whether belief bias effects can manifest themselves on the relational inference task. Subjects evaluated the validity of conclusions such as William the Conqueror was king after the Pyramids were built (temporal task) or Manchester is north of Bournemouth (spatial task) with respect to their premises. All of the major findings for equivalent categorical syllogism tasks were replicated. However, the overall size of the main effect of believability appears to be related to task presentation, a phenomenon not previously identified for categorical syllogisms and which current theories of belief bias have difficulty explaining.

  18. Mindfulness reduces the correspondence bias.

    Science.gov (United States)

    Hopthrow, Tim; Hooper, Nic; Mahmood, Lynsey; Meier, Brian P; Weger, Ulrich

    2017-03-01

    The correspondence bias (CB) refers to the idea that people sometimes give undue weight to dispositional rather than situational factors when explaining behaviours and attitudes. Three experiments examined whether mindfulness, a non-judgmental focus on the present moment, could reduce the CB. Participants engaged in a brief mindfulness exercise (the raisin task), a control task, or an attention to detail task before completing a typical CB measure involving an attitude-attribution paradigm. The results indicated that participants in the mindfulness condition experienced a significant reduction in the CB compared to participants in the control or attention to detail conditions. These results suggest that mindfulness training can play a unique role in reducing social biases related to person perception.

  19. Opinion Dynamics with Confirmation Bias

    CERN Document Server

    Allahverdyan, A E

    2014-01-01

    Background: Confirmation bias is the tendency to acquire or evaluate new information in a way that is consistent with one's preexisting beliefs. It is omnipresent in psychology, economics, and even scientific practices. Prior theoretical research of this phenomenon has mainly focused on its economic implications possibly missing its potential connections with broader notions of cognitive science. Methodology/Principal Findings: We formulate a (non-Bayesian) model for revising subjective probabilistic opinion of a confirmationally-biased agent in the light of a persuasive opinion. The revision rule ensures that the agent does not react to persuasion that is either far from his current opinion or coincides with it. We demonstrate that the model accounts for the basic phenomenology of the social judgment theory, and allows to study various phenomena such as cognitive dissonance and boomerang effect. The model also displays the order of presentation effect|when consecutively exposed to two opinions, the preferenc...

  20. Are temperature reconstructions regionally biased?

    CERN Document Server

    Bothe, O

    2012-01-01

    Are temperature reconstructions possibly biased due to regionally differing density of utilized proxy-networks? This question is assessed utilizing a simple process-based forward model of tree growth in the virtual reality of two simulations of the climate of the last millennium with different amplitude of solar forcing variations. The pseudo-tree ring series cluster in high latitudes of the northern hemisphere and east Asia. Only weak biases are found for the full network. However, for a strong solar forcing amplitude the high latitudes indicate a warmer first half of the last millennium while mid-latitudes and Asia were slightly colder than the extratropical hemispheric average. Reconstruction skill is weak or non-existent for two simple reconstruction schemes, and comparison of virtual reality target and reconstructions reveals strong deficiencies. The temporal resolution of the proxies has an influence on the reconstruction task and results are sensitive to the construction of the proxy-network. Existing ...

  1. Using decision models to decompose anxiety-related bias in threat classification.

    Science.gov (United States)

    White, Corey N; Skokin, Kimberly; Carlos, Brandon; Weaver, Alexandria

    2016-03-01

    Individuals with high levels of anxiety show preferential processing of threatening information, and this cognitive bias is thought to be an integral component of anxiety disorders. In threat classification tasks, this bias manifests as high-anxiety participants being more likely to classify stimuli as threatening than their low-anxiety counterparts. However, it is unclear which cognitive mechanisms drive this bias in threat classification. To better understand this phenomenon, threat classification data were analyzed with 2 decision models: a signal detection model and a drift-diffusion model. Signal detection models can dissociate measures of discriminability and bias, and diffusion models can further dissociate bias due to response preparation from bias due to stimulus evaluation. Individuals in the study completed a trait anxiety measure and classified threatening and neutral words based on whether they deemed them threatening. Signal detection analysis showed that high-anxiety participants had a bias driven by a weaker threat criterion than low-anxiety participants, but no differences in discriminability. Drift-diffusion analysis further decomposed the threat bias to show that it is driven by both an expectation bias that the threat response was more likely to be correct, and a stimulus bias driven by a weaker criterion for evaluating the stimuli under consideration. These model-based analyses provide valuable insight and show that multiple cognitive mechanisms underlie differential threat processing in anxiety. Implications for theories of anxiety are discussed.

  2. Effects of GC bias in next-generation-sequencing data on de novo genome assembly.

    Science.gov (United States)

    Chen, Yen-Chun; Liu, Tsunglin; Yu, Chun-Hui; Chiang, Tzen-Yuh; Hwang, Chi-Chuan

    2013-01-01

    Next-generation-sequencing (NGS) has revolutionized the field of genome assembly because of its much higher data throughput and much lower cost compared with traditional Sanger sequencing. However, NGS poses new computational challenges to de novo genome assembly. Among the challenges, GC bias in NGS data is known to aggravate genome assembly. However, it is not clear to what extent GC bias affects genome assembly in general. In this work, we conduct a systematic analysis on the effects of GC bias on genome assembly. Our analyses reveal that GC bias only lowers assembly completeness when the degree of GC bias is above a threshold. At a strong GC bias, the assembly fragmentation due to GC bias can be explained by the low coverage of reads in the GC-poor or GC-rich regions of a genome. This effect is observed for all the assemblers under study. Increasing the total amount of NGS data thus rescues the assembly fragmentation because of GC bias. However, the amount of data needed for a full rescue depends on the distribution of GC contents. Both low and high coverage depths due to GC bias lower the accuracy of assembly. These pieces of information provide guidance toward a better de novo genome assembly in the presence of GC bias.

  3. Competition and Commercial Media Bias

    OpenAIRE

    A. Blasco; F. Sobbrio

    2011-01-01

    This paper reviews the empirical evidence on commercial media bias (i.e., advertisers influence over media accuracy) and then introduces a simple model to summarize the main elements of the theoretical literature. The analysis provides three main policy insights for media regulators: i) Media regulators should target their monitoring efforts towards news contents upon which advertisers are likely to share similar preferences; ii) In advertising industries characterized by high correlation in ...

  4. BEHAVIORAL BIASES IN TRADING SECURITIES

    Directory of Open Access Journals (Sweden)

    Turcan Ciprian Sebastian

    2010-12-01

    Full Text Available The main thesis of this paper represents the importance and the effects that human behavior has over capital markets. It is important to see the link between the asset valuation and investor sentiment that motivate to pay for an asset a certain prices over/below the intrinsic value. The main behavioral aspects discussed are emotional factors such as: fear of regret, overconfidence, perseverance, loss aversion ,heuristic biases, misinformation and thinking errors, herding and their consequences.

  5. Magnitude of negative interpretation bias depends on severity of depression.

    Science.gov (United States)

    Lee, Jong-Sun; Mathews, Andrew; Shergill, Sukhi; Yiend, Jenny

    2016-08-01

    The present study investigated the hypothesis that the magnitude of negative interpretation bias displayed by those with depression is related to the degree of depression they experience. Seventy one depressed participants (scoring 14 and above on the Beck Depression Inventory II) completed tasks spanning three domains of possible negative interpretations: semantic ambiguity; nonverbal ambiguity and situational ambiguity. Regression analyses revealed that just under half of the variance in depressive symptom severity was explained by the combination of negative interpretation bias tasks, with the strongest predictor of depressive symptom severity being negative interpretation of semantic ambiguity when reading ambiguous text descriptions. Subsidiary group analyses confirmed that severely depressed individuals interpreted emotionally ambiguous information in a more negative way than did their mildly or moderately depressed counterparts. These findings indicate that the degree of negative interpretive bias is closely related to depression severity and that bias manifests especially strongly at the most severe levels of depression. Our findings may help us to refine cognitive theories of depression and be helpful in guiding therapy.

  6. Measuring bias from unbiased observable

    CERN Document Server

    Lee, Seokcheon

    2014-01-01

    Since Kaiser introduced galaxies as a biased tracer of the underlying total mass field, the linear galaxies bias, b(z) appears ubiquitously both in theoretical calculations and in observational measurements related to galaxy surveys. However, the generic approaches to the galaxy density is a non-local and stochastic function of the underlying dark matter density and it becomes difficult to make the analytic form of b(z). Due to this fact, b(z) is known as a nuisance parameter and the effort has been made to measure bias free observable quantities. We provide the exact and analytic function of b(z) which also can be measured from galaxy surveys using the redshift space distortions parameters, more accurately unbiased observable \\beta \\sigma_{\\rm{gal}} = f \\sigma_8. We also introduce approximate solutions for b(z) for different gravity theories. One can generalize these approximate solutions to be exact when one solves the exact evolutions for the dark matter density fluctuation of given gravity theories. These...

  7. Response bias in plaintiffs' histories.

    Science.gov (United States)

    Lees-Haley, P R; Williams, C W; Zasler, N D; Marguilies, S; English, L T; Stevens, K B

    1997-11-01

    This study investigated response bias in self-reported history of factors relevant to the assessment of traumatic brain injury, toxic brain injury and related emotional distress. Response bias refers to systematic error in self-report data. A total of 446 subjects (comprising 131 litigating and 315 non-litigating adults from five locations in the United States) completed a symptom questionnaire. Data were obtained from university faculty and students, from patients in clinics specializing in physiatry neurology, and family medicine, and from plaintiffs undergoing forensic neuropsychological evaluations. Comparisons were made for litigant and non litigant ratings of their past and current cognitive and emotional functioning, including life in general, ability to concentrate, memory, depression, anxiety, alcohol, drugs, ability to work or attend school, irritability, headaches, confusion, self-esteem, and fatigue. Although there is no basis for hypothesizing plaintiffs to be healthier than the general population, plaintiffs rated their pre-injury functioning superior to non-plaintiffs. These findings suggest that response biases need to be taken into account by forensic examiners when relying on litigants' self-reports of pre-injury status.

  8. Opinion dynamics with confirmation bias.

    Science.gov (United States)

    Allahverdyan, Armen E; Galstyan, Aram

    2014-01-01

    Confirmation bias is the tendency to acquire or evaluate new information in a way that is consistent with one's preexisting beliefs. It is omnipresent in psychology, economics, and even scientific practices. Prior theoretical research of this phenomenon has mainly focused on its economic implications possibly missing its potential connections with broader notions of cognitive science. We formulate a (non-Bayesian) model for revising subjective probabilistic opinion of a confirmationally-biased agent in the light of a persuasive opinion. The revision rule ensures that the agent does not react to persuasion that is either far from his current opinion or coincides with it. We demonstrate that the model accounts for the basic phenomenology of the social judgment theory, and allows to study various phenomena such as cognitive dissonance and boomerang effect. The model also displays the order of presentation effect-when consecutively exposed to two opinions, the preference is given to the last opinion (recency) or the first opinion (primacy) -and relates recency to confirmation bias. Finally, we study the model in the case of repeated persuasion and analyze its convergence properties. The standard Bayesian approach to probabilistic opinion revision is inadequate for describing the observed phenomenology of persuasion process. The simple non-Bayesian model proposed here does agree with this phenomenology and is capable of reproducing a spectrum of effects observed in psychology: primacy-recency phenomenon, boomerang effect and cognitive dissonance. We point out several limitations of the model that should motivate its future development.

  9. Opinion dynamics with confirmation bias.

    Directory of Open Access Journals (Sweden)

    Armen E Allahverdyan

    Full Text Available Confirmation bias is the tendency to acquire or evaluate new information in a way that is consistent with one's preexisting beliefs. It is omnipresent in psychology, economics, and even scientific practices. Prior theoretical research of this phenomenon has mainly focused on its economic implications possibly missing its potential connections with broader notions of cognitive science.We formulate a (non-Bayesian model for revising subjective probabilistic opinion of a confirmationally-biased agent in the light of a persuasive opinion. The revision rule ensures that the agent does not react to persuasion that is either far from his current opinion or coincides with it. We demonstrate that the model accounts for the basic phenomenology of the social judgment theory, and allows to study various phenomena such as cognitive dissonance and boomerang effect. The model also displays the order of presentation effect-when consecutively exposed to two opinions, the preference is given to the last opinion (recency or the first opinion (primacy -and relates recency to confirmation bias. Finally, we study the model in the case of repeated persuasion and analyze its convergence properties.The standard Bayesian approach to probabilistic opinion revision is inadequate for describing the observed phenomenology of persuasion process. The simple non-Bayesian model proposed here does agree with this phenomenology and is capable of reproducing a spectrum of effects observed in psychology: primacy-recency phenomenon, boomerang effect and cognitive dissonance. We point out several limitations of the model that should motivate its future development.

  10. A systematic evaluation of the quality of meta-analyses in endodontics.

    Science.gov (United States)

    Suebnukarn, Siriwan; Ngamboonsirisingh, Sureeporn; Rattanabanlang, Angwara

    2010-04-01

    Meta-analyses have been suggested to be the highest form of evidence available to clinicians to guide clinical practice in dental care. High methodologic quality is a prerequisite for valid interpretation and application of review findings. However, meta-analyses are complex exercises, and assessing quality can be a daunting task. Clinicians and policymakers require guidance, which is not provided adequately by the available literature on the quality of meta-analyses. The purpose of this study was to systematically evaluate the quality of meta-analyses that address topics pertinent to endodontics. To identify potentially eligible meta-analyses for inclusion, systematic searches performed in MEDLINE and the Cochrane Database of Systematic Reviews were enriched by hand searches, citation mining, and expert recommendation. Comprehensive search strategies were constructed for electronic searches. Predetermined inclusion criteria were applied to each identified meta-analysis independently by two reviewers. To assess report quality, the included meta-analyses were assessed by using A Measurement Tool to Assess Systematic Reviews (AMSTAR). A total of 16 reports of meta-analyses were included (kappa = 0.96). The overall quality of reports of meta-analyses was found to be high, with an estimated mean overall AMSTAR score of 8.33 out of 11 (95% confidence interval, 7.62-8.88). The weakest areas within the included meta-analyses were failure to report the likelihood of publication bias. The overall quality of the reports of meta-analyses available in endodontics is high according to AMSTAR. Copyright (c) 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. The Contingent Valuation Method in Public Libraries

    Science.gov (United States)

    Chung, Hye-Kyung

    2008-01-01

    This study aims to present a new model measuring the economic value of public libraries, combining the dissonance minimizing (DM) and information bias minimizing (IBM) format in the contingent valuation (CV) surveys. The possible biases which are tied to the conventional CV surveys are reviewed. An empirical study is presented to compare the model…

  12. The Contingent Valuation Method in Public Libraries

    Science.gov (United States)

    Chung, Hye-Kyung

    2008-01-01

    This study aims to present a new model measuring the economic value of public libraries, combining the dissonance minimizing (DM) and information bias minimizing (IBM) format in the contingent valuation (CV) surveys. The possible biases which are tied to the conventional CV surveys are reviewed. An empirical study is presented to compare the model…

  13. Health Indicators: Eliminating bias from convenience sampling estimators

    OpenAIRE

    Hedt, Bethany L.; Pagano, Marcello

    2011-01-01

    Public health practitioners are often called upon to make inference about a health indicator for a population at large when the sole available information are data gathered from a convenience sample, such as data gathered on visitors to a clinic. These data may be of the highest quality and quite extensive, but the biases inherent in a convenience sample preclude the legitimate use of powerful inferential tools that are usually associated with a random sample. In general, we know nothing abou...

  14. Matrilateral Bias in Human Grandmothering

    Directory of Open Access Journals (Sweden)

    Martin Daly

    2017-09-01

    Full Text Available Children receive more care and resources from their maternal grandmothers than from their paternal grandmothers. This asymmetry is the “matrilateral bias” in grandmaternal investment. Here, we synopsize the evolutionary theories that predict such a bias, and review evidence of its cross-cultural generality and magnitude. Evolutionists have long maintained that investing in a daughter’s child yields greater fitness returns, on average, than investing in a son’s child because of paternity uncertainty: the son’s putative progeny may have been sired by someone else. Recent theoretical work has identified an additional natural selective basis for the matrilateral bias that may be no less important: supporting grandchildren lightens the load on their mother, increasing her capacity to pursue her fitness in other ways, and if she invests those gains either in her natal relatives or in children of a former or future partner, fitness returns accrue to the maternal, but not the paternal, grandmother. In modern democracies, where kinship is reckoned bilaterally and no postmarital residence norms restrict grandmaternal access to grandchildren, many studies have found large matrilateral biases in contact, childcare, and emotional closeness. In other societies, patrilineal ideology and postmarital residence with the husband’s kin (virilocality might be expected to have produced a patrilateral bias instead, but the available evidence refutes this hypothesis. In hunter-gatherers, regardless of professed norms concerning kinship and residence, mothers get needed help at and after childbirth from their mothers, not their mothers-in-law. In traditional agricultural and pastoral societies, patrilineal and virilocal norms are common, but young mothers still turn to their natal families for crucial help, and several studies have documented benefits, including reduced child mortality, associated with access to maternal, but not paternal, grandmothers. Even

  15. Bias-correction in vector autoregressive models

    DEFF Research Database (Denmark)

    Engsted, Tom; Pedersen, Thomas Quistgaard

    2014-01-01

    We analyze the properties of various methods for bias-correcting parameter estimates in both stationary and non-stationary vector autoregressive models. First, we show that two analytical bias formulas from the existing literature are in fact identical. Next, based on a detailed simulation study......, we show that when the model is stationary this simple bias formula compares very favorably to bootstrap bias-correction, both in terms of bias and mean squared error. In non-stationary models, the analytical bias formula performs noticeably worse than bootstrapping. Both methods yield a notable...... improvement over ordinary least squares. We pay special attention to the risk of pushing an otherwise stationary model into the non-stationary region of the parameter space when correcting for bias. Finally, we consider a recently proposed reduced-bias weighted least squares estimator, and we find...

  16. The Probability Distribution for a Biased Spinner

    Science.gov (United States)

    Foster, Colin

    2012-01-01

    This article advocates biased spinners as an engaging context for statistics students. Calculating the probability of a biased spinner landing on a particular side makes valuable connections between probability and other areas of mathematics. (Contains 2 figures and 1 table.)

  17. The Probability Distribution for a Biased Spinner

    Science.gov (United States)

    Foster, Colin

    2012-01-01

    This article advocates biased spinners as an engaging context for statistics students. Calculating the probability of a biased spinner landing on a particular side makes valuable connections between probability and other areas of mathematics. (Contains 2 figures and 1 table.)

  18. L' analyse des préférences des téléspectateurs extraterritoriaux dans le football : application au public de deux régions marocaines

    OpenAIRE

    Kada, Faycel

    2013-01-01

    The globalization of football as entertainment and the changes in media have generated the development of a new category of public: international viewers. Understanding their behavior proves to be an important research topic for the marketing of federations, leagues and professional clubs. The research is focused on understanding the preferences of international viewers who follow football games in the media. From a theoretical point of view, the conceptual model and the hypotheses have been ...

  19. A Pharmacological Primer of Biased Agonism

    OpenAIRE

    Andresen, Bradley T.

    2011-01-01

    Biased agonism is one of the fastest growing topics in G protein-coupled receptor pharmacology; moreover, biased agonists are used in the clinic today: carvedilol (Coreg®) is a biased agonist of beta-adrenergic receptors. However, there is a general lack of understanding of biased agonism when compared to traditional pharmacological terminology. Therefore, this review is designed to provide a basic introduction to classical pharmacology as well as G protein-coupled receptor signal transductio...

  20. Attentional bias predicts heroin relapse following treatment

    NARCIS (Netherlands)

    M.A.E. Marissen; I.H.A. Franken; A.J. Waters; P. Blanken; W. van den Brink; V.M. Hendriks

    2006-01-01

    Aims Previous studies have shown that abstinent heroin addicts exhibit an attentional bias to heroin-related stimuli. It has been suggested that attentional bias may represent a vulnerability to relapse into drug use. In the present study, the predictive value of pre-treatment attentional bias on re

  1. Using Newspapers to Study Media Bias.

    Science.gov (United States)

    Kirman, Joseph M.

    1992-01-01

    Suggests that students can learn to recognize media bias by studying media reports of current events or historical topics. Describes a study unit using media coverage of the second anniversary of the Palestinian uprising against Israel. Discusses lesson objectives, planning, defining bias teaching procedures, and criteria for determining bias. (DK)

  2. Culturally Biased Assumptions in Counseling Psychology

    Science.gov (United States)

    Pedersen, Paul B.

    2003-01-01

    Eight clusters of culturally biased assumptions are identified for further discussion from Leong and Ponterotto's (2003) article. The presence of cultural bias demonstrates that cultural bias is so robust and pervasive that is permeates the profession of counseling psychology, even including those articles that effectively attack cultural bias…

  3. Why choice of metric matters in public health analyses: a case study of the attribution of credit for the decline in coronary heart disease mortality in the US and other populations

    Directory of Open Access Journals (Sweden)

    Gouda Hebe N

    2012-01-01

    Full Text Available Abstract Background Reasons for the widespread declines in coronary heart disease (CHD mortality in high income countries are controversial. Here we explore how the type of metric chosen for the analyses of these declines affects the answer obtained. Methods The analyses we reviewed were performed using IMPACT, a large Excel based model of the determinants of temporal change in mortality from CHD. Assessments of the decline in CHD mortality in the USA between 1980 and 2000 served as the central case study. Results Analyses based in the metric of number of deaths prevented attributed about half the decline to treatments (including preventive medications and half to favourable shifts in risk factors. However, when mortality change was expressed in the metric of life-years-gained, the share attributed to risk factor change rose to 65%. This happened because risk factor changes were modelled as slowing disease progression, such that the hypothetical deaths averted resulted in longer average remaining lifetimes gained than the deaths averted by better treatments. This result was robust to a range of plausible assumptions on the relative effect sizes of changes in treatments and risk factors. Conclusions Time-based metrics (such as life years are generally preferable because they direct attention to the changes in the natural history of disease that are produced by changes in key health determinants. The life-years attached to each death averted will also weight deaths in a way that better reflects social preferences.

  4. Public Speech.

    Science.gov (United States)

    Green, Thomas F.

    1994-01-01

    Discusses the importance of public speech in society, noting the power of public speech to create a world and a public. The paper offers a theory of public speech, identifies types of public speech, and types of public speech fallacies. Two ways of speaking of the public and of public life are distinguished. (SM)

  5. Globalization, tax distortions and public sector retrenchment

    DEFF Research Database (Denmark)

    Andersen, Torben M.; Sørensen, Allan

    income taxation unambiguously worsens wage competitiveness, it does not follow that marginal costs of public funds increase with product market integration due to gains from trade. Moreover, non-cooperative fiscal policies do not have a race-to-the-bottom bias despite that taxes harm competitiveness....... In fact we identify an expansionary bias in …scal policies that is likely to increase with globalization when taxes finance either public consumption or transfers....

  6. A statistical characterization of the Galileo-to-GPS inter-system bias

    Science.gov (United States)

    Gioia, Ciro; Borio, Daniele

    2016-11-01

    Global navigation satellite system operates using independent time scales and thus inter-system time offsets have to be determined to enable multi-constellation navigation solutions. GPS/Galileo inter-system bias and drift are evaluated here using different types of receivers: two mass market and two professional receivers. Moreover, three different approaches are considered for the inter-system bias determination: in the first one, the broadcast Galileo to GPS time offset is used to align GPS and Galileo time scales. In the second, the inter-system bias is included in the multi-constellation navigation solution and is estimated using the measurements available. Finally, an enhanced algorithm using constraints on the inter-system bias time evolution is proposed. The inter-system bias estimates obtained with the different approaches are analysed and their stability is experimentally evaluated using the Allan deviation. The impact of the inter-system bias on the position velocity time solution is also considered and the performance of the approaches analysed is evaluated in terms of standard deviation and mean errors for both horizontal and vertical components. From the experiments, it emerges that the inter-system bias is very stable and that the use of constraints, modelling the GPS/Galileo inter-system bias behaviour, significantly improves the performance of multi-constellation navigation.

  7. Limitations and sources of bias in clinical knee cartilage research.

    Science.gov (United States)

    Worthen, Jamie; Waterman, Brian R; Davidson, Philip A; Lubowitz, James H

    2012-09-01

    The purpose of this study was to systematically review the limitations and biases inherent to surgical trials on the management of knee chondral defects. A literature search of PubMed/Medline, CINAHL (Cumulative Index to Nursing and Allied Health Literature), EMBASE, and the Cochrane Central Register of Controlled Trials was conducted in September 2010 and updated in August 2011 to identify all English-language, Level I evidence, prospective, randomized controlled trials published from 1996 to present. The keyword search included the following: "autologous chondrocyte," "cartilage graft," "cartilage repair," "chondroplasty," "microfracture," "mosaicplasty," and/or "osteochondral." Nonoperative studies, nonhuman studies, ex vivo studies, non-knee studies, and/or studies with follow-up of less than 1 year were excluded. A systematic review was performed on all included studies, and limitations and/or biases were identified and quantitated. Of 15,311 citations, 33 abstracts were reviewed and 11 prospective, randomized controlled trials were included. We identified 9 major limitations (subject age, subject prior surgery, subject duration of symptoms, lesion location, lesion size, lesion number, procedure selection, procedure standardization, and limited histologic analysis) and 7 common biases (selection, performance, transfer, nonresponder, detection, publication, and study design). Level I therapeutic studies investigating the surgical management of human knee cartilage defects have substantial identified biases and limitations. This review has limitations because other classifications of bias or limitation exist. Optimal management of cartilage defects is controversial, and future rigorous research methods could minimize common biases through strict study design and patient selection criteria, larger patient enrollment, more extended follow-up, and standardization of clinical treatment pathways. Level I, systematic review of Level I studies. Copyright © 2012

  8. A Review of Studies on Media Bias at Home

    Institute of Scientific and Technical Information of China (English)

    辛一丹

    2015-01-01

    Bias is widely existed nowadays.Domestic scholars have done a lot of research on the bias,especially the media bias.They studied the media bias from different perspectives,such as the bias on China image,the bias of a certain media FOX,the bias on the venerable group,the bias on women and so on.The author plans to give a review of the studies on media bias at home in this paper.

  9. A Review of Studies on Media Bias at Home

    Institute of Scientific and Technical Information of China (English)

    辛一丹

    2015-01-01

    Bias is widely existed nowadays. Domestic scholars have done a lot of research on the bias, especially the media bias. They studied the media bias from different perspectives, such as the bias on China image,the bias of a certain media FOX, the bias on the venerable group, the bias on women and so on. The author plans to give a review of the studies on media bias at home in this paper.

  10. Opinion Dynamics with Confirmation Bias

    Science.gov (United States)

    Allahverdyan, Armen E.; Galstyan, Aram

    2014-01-01

    Background Confirmation bias is the tendency to acquire or evaluate new information in a way that is consistent with one's preexisting beliefs. It is omnipresent in psychology, economics, and even scientific practices. Prior theoretical research of this phenomenon has mainly focused on its economic implications possibly missing its potential connections with broader notions of cognitive science. Methodology/Principal Findings We formulate a (non-Bayesian) model for revising subjective probabilistic opinion of a confirmationally-biased agent in the light of a persuasive opinion. The revision rule ensures that the agent does not react to persuasion that is either far from his current opinion or coincides with it. We demonstrate that the model accounts for the basic phenomenology of the social judgment theory, and allows to study various phenomena such as cognitive dissonance and boomerang effect. The model also displays the order of presentation effect–when consecutively exposed to two opinions, the preference is given to the last opinion (recency) or the first opinion (primacy) –and relates recency to confirmation bias. Finally, we study the model in the case of repeated persuasion and analyze its convergence properties. Conclusions The standard Bayesian approach to probabilistic opinion revision is inadequate for describing the observed phenomenology of persuasion process. The simple non-Bayesian model proposed here does agree with this phenomenology and is capable of reproducing a spectrum of effects observed in psychology: primacy-recency phenomenon, boomerang effect and cognitive dissonance. We point out several limitations of the model that should motivate its future development. PMID:25007078

  11. Ratio Bias and Policy Preferences

    DEFF Research Database (Denmark)

    Pedersen, Rasmus Tue

    2016-01-01

    Numbers permeate modern political communication. While current scholarship on framing effects has focused on the persuasive effects of words and arguments, this article shows that framing of numbers can also substantially affect policy preferences. Such effects are caused by ratio bias, which...... is a general tendency to focus on numerators and pay insufficient attention to denominators in ratios. Using a population-based survey experiment, I demonstrate how differently framed but logically equivalent representations of the exact same numerical value can have large effects on citizens’ preferences...

  12. Magnetoelectric switching of exchange bias.

    Science.gov (United States)

    Borisov, Pavel; Hochstrat, Andreas; Chen, Xi; Kleemann, Wolfgang; Binek, Christian

    2005-03-25

    The perpendicular exchange bias field, H(EB), of the magnetoelectric heterostructure Cr2O3(111)/(Co/Pt)(3) changes sign after field cooling to below the Néel temperature of Cr2O3 in either parallel or antiparallel axial magnetic and electric freezing fields. The switching of H(EB) is explained by magnetoelectrically induced antiferromagnetic single domains which extend to the interface, where the direction of their end spins controls the sign of H(EB). Novel applications in magnetoelectronic devices seem possible.

  13. Lane bias in elite-level swimming competition.

    Science.gov (United States)

    Brammer, Christopher; Cornett, Andrew; Stager, Joel

    2017-02-01

    Performance outcomes at the 2013 World Swimming Championship were previously shown to be biased depending on the swimmer's lane assignment. The purpose of this study was to determine if this kind of bias was unique, and if not, if the bias was related to the temporary or permanent nature of the pool. The effect of lane on the average odd-length split minus the preceding even-length split in the 800- and 1500-m freestyle events, and on the relative change from qualifying to preliminary performance in the 50-m events, was determined for 16 other elite-level competitions. Depending on the swimmers' direction, split times were on average 0.16 s slower or faster in at least one lane at each of the 16 competitions, and in 49% of all lanes analysed. In 5 competitions, swimmers were shown to be faster in a majority of lanes in one direction as compared to the other. Analysis of the 50-m events at these 5 competitions indicate that preliminary performances were between 0.5 and 0.9% slower or faster than qualifying times, which is consistent with the direction effect observed in the distance freestyle events. Further, lane biases occur more often in temporary pools (70% of lanes) than in permanent pools (35% of lanes), with water currents as the most plausible cause. The prevalence of lane bias at elite-level swimming competition highlights the need for the implementation of policies and procedures to prevent such bias from occurring again in the future.

  14. High and far: biases in the location of protected areas.

    Directory of Open Access Journals (Sweden)

    Lucas N Joppa

    Full Text Available BACKGROUND: About an eighth of the earth's land surface is in protected areas (hereafter "PAs", most created during the 20(th century. Natural landscapes are critical for species persistence and PAs can play a major role in conservation and in climate policy. Such contributions may be harder than expected to implement if new PAs are constrained to the same kinds of locations that PAs currently occupy. METHODOLOGY/PRINCIPAL FINDINGS: Quantitatively extending the perception that PAs occupy "rock and ice", we show that across 147 nations PA networks are biased towards places that are unlikely to face land conversion pressures even in the absence of protection. We test each country's PA network for bias in elevation, slope, distances to roads and cities, and suitability for agriculture. Further, within each country's set of PAs, we also ask if the level of protection is biased in these ways. We find that the significant majority of national PA networks are biased to higher elevations, steeper slopes and greater distances to roads and cities. Also, within a country, PAs with higher protection status are more biased than are the PAs with lower protection statuses. CONCLUSIONS/SIGNIFICANCE: In sum, PAs are biased towards where they can least prevent land conversion (even if they offer perfect protection. These globally comprehensive results extend findings from nation-level analyses. They imply that siting rules such as the Convention on Biological Diversity's 2010 Target [to protect 10% of all ecoregions] might raise PA impacts if applied at the country level. In light of the potential for global carbon-based payments for avoided deforestation or REDD, these results suggest that attention to threat could improve outcomes from the creation and management of PAs.

  15. Numeracy and framing bias in epilepsy.

    Science.gov (United States)

    Choi, Hyunmi; Wong, John B; Mendiratta, Anil; Heiman, Gary A; Hamberger, Marla J

    2011-01-01

    Patients with epilepsy are frequently confronted with complex treatment decisions. Communicating treatment risks is often difficult because patients may have difficulty with basic statistical concepts (i.e., low numeracy) or might misconceive the statistical information based on the way information is presented, a phenomenon known as "framing bias." We assessed numeracy and framing bias in 95 adults with chronic epilepsy and explored cognitive correlates of framing bias. Compared with normal controls, patients with epilepsy had significantly poorer performance on the Numeracy scale (P=0.02), despite a higher level of education than normal controls (Pframing bias. Abstract problem solving performance correlated with the degree of framing bias (r=0.631, Pframing bias. Poor numeracy and susceptibility framing bias place patients with epilepsy at risk for uninformed decisions.

  16. New insights into the interplay between codon bias determinants in plants.

    Science.gov (United States)

    Camiolo, S; Melito, S; Porceddu, A

    2015-12-01

    Codon bias is the non-random use of synonymous codons, a phenomenon that has been observed in species as diverse as bacteria, plants and mammals. The preferential use of particular synonymous codons may reflect neutral mechanisms (e.g. mutational bias, G|C-biased gene conversion, genetic drift) and/or selection for mRNA stability, translational efficiency and accuracy. The extent to which these different factors influence codon usage is unknown, so we dissected the contribution of mutational bias and selection towards codon bias in genes from 15 eudicots, 4 monocots and 2 mosses. We analysed the frequency of mononucleotides, dinucleotides and trinucleotides and investigated whether the compositional genomic background could account for the observed codon usage profiles. Neutral forces such as mutational pressure and G|C-biased gene conversion appeared to underlie most of the observed codon bias, although there was also evidence for the selection of optimal translational efficiency and mRNA folding. Our data confirmed the compositional differences between monocots and dicots, with the former featuring in general a lower background compositional bias but a higher overall codon bias. © The Author 2015. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  17. Heart Failure Therapeutics on the Basis of a Biased Ligand of the Angiotensin-2 Type 1 Receptor Rationale and Design of the BLAST-AHF Study (Biased Ligand of the Angiotensin Receptor Study in Acute Heart Failure)

    NARCIS (Netherlands)

    Felker, G. Michael; Butler, Javed; Collins, Sean P.; Cotter, Gad; Davison, Beth A.; Ezekowitz, Justin A.; Filippatos, Gerasimos; Levy, Phillip D.; Metra, Marco; Ponikowski, Piotr; Soergel, David G.; Teerlink, John R.; Violin, Jonathan D.; Voors, Adriaan A.; Pang, Peter S.

    2015-01-01

    The BLAST-AHF (Biased Ligand of the Angiotensin Receptor Study in Acute Heart Failure) study is designed to test the efficacy and safety of TRV027, a novel biased ligand of the angiotensin-2 type 1 receptor, in patients with acute heart failure (AHF). AHF remains a major public health problem, and n

  18. 公安院校女生心理压力分析及调节策略研究%A Study on Psychological Pressure Analyses of Girls and Adjustment Strategies in Public Security colleges and universities

    Institute of Scientific and Technical Information of China (English)

    杨恒毅

    2012-01-01

      As the reserve police officers of the People’s Republic of China, girls in public security colleges and universities shoulder the great task of national public security career development while girls are much easier than boys under the influence of psychological pressures caused by their physiological and psychological factors. Whether we can effectively help girls eliminate their psychological pressures and make them keep healthy in body and mind will directly affect the qualities of the future police groups. This article analyzed girls’ psychological pressures from the policing management model, study pressures and employment pressures, and further put forward some countermeasures to help girls in public security colleges and universities to accept psychological counseling so as to ease psychological pressures and maintain psychological health by strengthening communication, building a learning environment and enhancing psychological guidance, etc..%  公安院校女生作为共和国的预备警官,承载着祖国公安事业发展的重任,而女性特殊的生理心理因素,使她们较男性更容易受到心理压力的侵扰,所以能否有效帮助公安院校女生疏导心理压力,保持身心健康将直接影响到未来警察群体的素质。本文主要从警务化管理产生的压力、学业压力和就业压力三方面对公安院校女生所面临的压力进行了剖析,并提出通过加强沟通交流、营造学习氛围、加强心理辅导等措施来帮助公安院校女生进行心理疏导,排解心理压力,保持心理健康。

  19. Differential effects of weight bias experiences and internalization on exercise among women with overweight and obesity.

    Science.gov (United States)

    Pearl, Rebecca L; Puhl, Rebecca M; Dovidio, John F

    2015-12-01

    This study investigated the effects of experiences with weight stigma and weight bias internalization on exercise. An online sample of 177 women with overweight and obesity (M(age) = 35.48 years, M(BMI) = 32.81) completed questionnaires assessing exercise behavior, self-efficacy, and motivation; experiences of weight stigmatization; weight bias internalization; and weight-stigmatizing attitudes toward others. Weight stigma experiences positively correlated with exercise behavior, but weight bias internalization was negatively associated with all exercise variables. Weight bias internalization was a partial mediator between weight stigma experiences and exercise behavior. The distinct effects of experiencing versus internalizing weight bias carry implications for clinical practice and public health. © The Author(s) 2014.

  20. The effect of cognitive bias modification for interpretation on avoidance of pain during an acute experimental pain task.

    Science.gov (United States)

    Jones, Emma Blaisdale; Sharpe, Louise

    2014-08-01

    Research confirms that patients with chronic pain show a tendency to interpret ambiguous stimuli as pain related. However, whether modifying these interpretive pain biases impacts pain outcomes is unknown. This study aimed to demonstrate that interpretation biases towards pain can be modified, and that changing these biases influences pain outcomes in the cold pressor task. One hundred and six undergraduate students were randomly allocated to receive either threatening or reassuring information regarding the cold pressor. They also were randomly allocated to 1 of 2 conditions in the Ambiguous Scenarios Task, in which they were trained to have either a threatening interpretation of pain (pain bias condition) or a nonthreatening interpretation of pain (no pain bias condition). Therefore, the study had a 2 (threat/reassuring)×2 (pain bias/no pain bias) design. Analyses showed that a bias was induced contingent on condition, and that the threat manipulation was effective. Participants in the pain bias condition hesitated more before doing the cold pressor task than those in the no pain bias condition, as did those in the threat compared with the reassurance condition. The major finding was that interpretive bias mediated the relationship between bias condition and hesitance time, supporting the causal role of interpretive biases for avoidance behaviors in current chronic pain models. No differences were found on other pain outcomes regarding bias or threat, and the efficacy of the bias modification was not impacted by different levels of threat. These results suggest that cognitive bias modification should be further explored as a potential intervention in pain.

  1. Sources and Implications of Bias and Uncertainty in a Century of US Wildfire Activity Data

    Science.gov (United States)

    Short, K.

    2013-12-01

    The statistical analysis of wildfire activity is a critical component of national wildfire planning, operations, and research in the United States (US). Wildfire activity data have been collected in the US for over a century. Yet, to this day, no single unified system of wildfire record-keeping exists. Data for analysis are generally harvested from archival summary reports from federal or interagency fire organizations; incident-level wildfire reporting systems of the federal, state, and local fire services; and, increasingly, remote-sensing programs. It is typical for research into wildfire activity patterns for all or part of the last century to require data from several of these sources and perhaps others. That work is complicated by the disunity of the various datasets and potentially compromised by inherent reporting biases, discussed here. The availability of wildfire records with the information content and geospatial precision generally sought for increasingly popular climatological analyses and the modeling of contemporary wildfire risk is limited to recent decades. We explain how the disunity and idiosyncrasies of US wildfire reporting have largely precluded true interagency, or all-lands, analyses of even recent wildfire activity and hamstrung some early risk modeling efforts. We then describe our efforts to acquire, standardize, error-check, compile, scrub, and evaluate the completeness of US federal, state, and local wildfire records from 1992-2011 for the national interagency Fire Program Analysis (FPA) application. The resulting FPA Fire-Occurrence Database (FPA FOD) includes nearly 1.6 million records from the 20-year period, with values for at least the following core data elements: location at least as precise as a Public Land Survey System section (2.6-km2 grid), discovery date, and final fire size. The FPA FOD is publicly available from the Research Data Archive of the US Department of Agriculture, Forest Service (http://dx.doi.org/10.2737/RDS

  2. Reporting quality of systematic reviews/meta-analyses of acupuncture.

    Directory of Open Access Journals (Sweden)

    Yali Liu

    Full Text Available The QUOROM and PRISMA statements were published in 1999 and 2009, respectively, to improve the consistency of reporting systematic reviews (SRs/meta-analyses (MAs of clinical trials. However, not all SRs/MAs adhere completely to these important standards. In particular, it is not clear how well SRs/MAs of acupuncture studies adhere to reporting standards and which reporting criteria are generally ignored in these analyses.To evaluate reporting quality in SRs/MAs of acupuncture studies.We performed a literature search for studies published prior to 2014 using the following public archives: PubMed, EMBASE, Web of Science, the Cochrane Database of Systematic Reviews (CDSR, the Chinese Biomedical Literature Database (CBM, the Traditional Chinese Medicine (TCM database, the Chinese Journal Full-text Database (CJFD, the Chinese Scientific Journal Full-text Database (CSJD, and the Wanfang database. Data were extracted into pre-prepared Excel data-extraction forms. Reporting quality was assessed based on the PRISMA checklist (27 items.Of 476 appropriate SRs/MAs identified in our search, 203, 227, and 46 were published in Chinese journals, international journals, and the Cochrane Database, respectively. In 476 SRs/MAs, only 3 reported the information completely. By contrast, approximately 4.93% (1/203, 8.81% (2/227 and 0.00% (0/46 SRs/Mas reported less than 10 items in Chinese journals, international journals and CDSR, respectively. In general, the least frequently reported items (reported≤50% in SRs/MAs were "protocol and registration", "risk of bias across studies", and "additional analyses" in both methods and results sections.SRs/MAs of acupuncture studies have not comprehensively reported information recommended in the PRISMA statement. Our study underscores that, in addition to focusing on careful study design and performance, attention should be paid to comprehensive reporting standards in SRs/MAs on acupuncture studies.

  3. Attention bias for chocolate increases chocolate consumption--an attention bias modification study.

    Science.gov (United States)

    Werthmann, Jessica; Field, Matt; Roefs, Anne; Nederkoorn, Chantal; Jansen, Anita

    2014-03-01

    The current study examined experimentally whether a manipulated attention bias for food cues increases craving, chocolate intake and motivation to search for hidden chocolates. To test the effect of attention for food on subsequent chocolate intake, attention for chocolate was experimentally modified by instructing participants to look at chocolate stimuli ("attend chocolate" group) or at non-food stimuli ("attend shoes" group) during a novel attention bias modification task (antisaccade task). Chocolate consumption, changes in craving and search time for hidden chocolates were assessed. Eye-movement recordings were used to monitor the accuracy during the experimental attention modification task as possible moderator of effects. Regression analyses were conducted to test the effect of attention modification and modification accuracy on chocolate intake, craving and motivation to search for hidden chocolates. Results showed that participants with higher accuracy (+1 SD), ate more chocolate when they had to attend to chocolate and ate less chocolate when they had to attend to non-food stimuli. In contrast, for participants with lower accuracy (-1 SD), the results were exactly reversed. No effects of the experimental attention modification on craving or search time for hidden chocolates were found. We used chocolate as food stimuli so it remains unclear how our findings generalize to other types of food. These findings demonstrate further evidence for a link between attention for food and food intake, and provide an indication about the direction of this relationship. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Public Service Motivation

    Directory of Open Access Journals (Sweden)

    Raluca-Marilena Mihalcioiu

    2011-05-01

    Full Text Available Public Service Motivation concept was developed in North America and focuses on specific motivations of public servants, such as employee satisfaction, organizational commitment, reward preferences, organizational and individual performance. Other types of motivation, as financial consideration, are relevant but have less important influences with regard to this kind of work outcomes. This strengthen the assertion for a diversified motivational strategy, which affect various types of motivation, while not losing sight of the public value that one organization shows and therefore valuing public service motivation as a specific contribution to work outcomes. The concept has been increasingly applied in European public administration. This paper presents Status Quo of international Public Service Motivation research and locates in them empirical evidences from contries that are already working with this concept, like Austria. It also analyses implications for central questions of public management. The main focus of this article is general appropriateness and possible applications for Romanian public management research.

  5. Facial expression judgments support a socio-relational model, rather than a negativity bias model of political psychology.

    Science.gov (United States)

    Vigil, Jacob M; Strenth, Chance

    2014-06-01

    Self-reported opinions and judgments may be more rooted in expressive biases than in cognitive processing biases, and ultimately operate within a broader behavioral style for advertising the capacity - versus the trustworthiness - dimension of human reciprocity potential. Our analyses of facial expression judgments of likely voters are consistent with this thesis, and directly contradict one major prediction from the authors' "negativity-bias" model.

  6. Observations and Models of Galaxy Assembly Bias

    Science.gov (United States)

    Campbell, Duncan A.

    2017-01-01

    The assembly history of dark matter haloes imparts various correlations between a halo’s physical properties and its large scale environment, i.e. assembly bias. It is common for models of the galaxy-halo connection to assume that galaxy properties are only a function of halo mass, implicitly ignoring how assembly bias may affect galaxies. Recently, programs to model and constrain the degree to which galaxy properties are influenced by assembly bias have been undertaken; however, the extent and character of galaxy assembly bias remains a mystery. Nevertheless, characterizing and modeling galaxy assembly bias is an important step in understanding galaxy evolution and limiting any systematic effects assembly bias may pose in cosmological measurements using galaxy surveys.I will present work on modeling and constraining the effect of assembly bias in two galaxy properties: stellar mass and star-formation rate. Conditional abundance matching allows for these galaxy properties to be tied to halo formation history to a variable degree, making studies of the relative strength of assembly bias possible. Galaxy-galaxy clustering and galactic conformity, the degree to which galaxy color is correlated between neighbors, are sensitive observational measures of galaxy assembly bias. I will show how these measurements can be used to constrain galaxy assembly bias and the peril of ignoring it.

  7. The Effect of Social Desirability Bias on Willingness-To-Pay for Organic Beef.

    OpenAIRE

    Cheek, Lindsey

    2007-01-01

    Researchers regularly conduct willingness-to-pay or valuation studies for product marketing or public policy purposes. However, a large volume of research suggests valuation tools such as conjoint analysis may be subject to social desirability bias, where subjects misrepresent their true preferences to create a favorable impression. The objective of this study is to measure the effects of social desirability bias on conjoint survey responses. Consumers were asked to rank organic ground beef r...

  8. Reducing Prejudice With Labels: Shared Group Memberships Attenuate Implicit Bias and Expand Implicit Group Boundaries.

    Science.gov (United States)

    Scroggins, W Anthony; Mackie, Diane M; Allen, Thomas J; Sherman, Jeffrey W

    2016-02-01

    In three experiments, we used a novel Implicit Association Test procedure to investigate the impact of group memberships on implicit bias and implicit group boundaries. Results from Experiment 1 indicated that categorizing targets using a shared category reduced implicit bias by increasing the extent to which positivity was associated with Blacks. Results from Experiment 2 revealed that shared group membership, but not mere positivity of a group membership, was necessary to reduce implicit bias. Quadruple process model analyses indicated that changes in implicit bias caused by shared group membership are due to changes in the way that targets are evaluated, not to changes in the regulation of evaluative bias. Results from Experiment 3 showed that categorizing Black targets into shared group memberships expanded implicit group boundaries.

  9. Approach bias modification training and consumption: A review of the literature.

    Science.gov (United States)

    Kakoschke, Naomi; Kemps, Eva; Tiggemann, Marika

    2017-01-01

    Recent theoretical perspectives and empirical evidence have suggested that biased cognitive processing is an important contributor to unhealthy behaviour. Approach bias modification is a novel intervention in which approach biases for appetitive cues are modified. The current review of the literature aimed to evaluate the effectiveness of modifying approach bias for harmful consumption behaviours, including alcohol use, cigarette smoking, and unhealthy eating. Relevant publications were identified through a search of four electronic databases (PsycINFO, Google Scholar, ScienceDirect and Scopus) that were conducted between October and December 2015. Eligibility criteria included the use of a human adult sample, at least one session of avoidance training, and an outcome measure related to the behaviour of interest. The fifteen identified publications (comprising 18 individual studies) were coded on a number of characteristics, including consumption behaviour, participants, task, training and control conditions, number of training sessions and trials, outcome measure, and results. The results generally showed positive effects of approach-avoidance training, including reduced consumption behaviour in the laboratory, lower relapse rates, and improvements in self-reported measures of behaviour. Importantly, all studies (with one exception) that reported favourable consumption outcomes also demonstrated successful reduction of the approach bias for appetitive cues. Thus, the current review concluded that approach bias modification is effective for reducing both approach bias and unhealthy consumption behaviour.

  10. Forecasts: uncertain, inaccurate and biased?

    DEFF Research Database (Denmark)

    Nicolaisen, Morten Skou; Ambrasaite, Inga; Salling, Kim Bang

    2012-01-01

    Cost Benefit Analysis (CBA) is the dominating methodology for appraisal of transport infrastructure projects across the globe. In order to adequately assess the costs and benefits of such projects two types of forecasts are crucial to the validity of the appraisal. First are the forecasts...... accuracy of project benefits. This paper presents results from an on-going research project on uncertainties in transport project evaluation (UNITE) that find forecasts of demand to be not only uncertain, but at times also highly inaccurate and often displaying a concerning degree of bias. Demand for road...... projects appear to be systematically underestimated, while demand for rail projects appears to be systematically overestimated. We compare the findings in the present study with those of previous studies and discuss the implications for the validity of project appraisal in the form of CBA...

  11. Social reward shapes attentional biases.

    Science.gov (United States)

    Anderson, Brian A

    2016-01-01

    Paying attention to stimuli that predict a reward outcome is important for an organism to survive and thrive. When visual stimuli are associated with tangible, extrinsic rewards such as money or food, these stimuli acquire high attentional priority and come to automatically capture attention. In humans and other primates, however, many behaviors are not motivated directly by such extrinsic rewards, but rather by the social feedback that results from performing those behaviors. In the present study, I examine whether positive social feedback can similarly influence attentional bias. The results show that stimuli previously associated with a high probability of positive social feedback elicit value-driven attentional capture, much like stimuli associated with extrinsic rewards. Unlike with extrinsic rewards, however, such stimuli also influence task-specific motivation. My findings offer a potential mechanism by which social reward shapes the information that we prioritize when perceiving the world around us.

  12. Forecasts: uncertain, inaccurate and biased?

    DEFF Research Database (Denmark)

    Nicolaisen, Morten Skou; Ambrasaite, Inga; Salling, Kim Bang

    2012-01-01

    Cost Benefit Analysis (CBA) is the dominating methodology for appraisal of transport infrastructure projects across the globe. In order to adequately assess the costs and benefits of such projects two types of forecasts are crucial to the validity of the appraisal. First are the forecasts...... of construction costs, which account for the majority of total project costs. Second are the forecasts of travel time savings, which account for the majority of total project benefits. The latter of these is, inter alia, determined by forecasts of travel demand, which we shall use as a proxy for the forecasting...... accuracy of project benefits. This paper presents results from an on-going research project on uncertainties in transport project evaluation (UNITE) that find forecasts of demand to be not only uncertain, but at times also highly inaccurate and often displaying a concerning degree of bias. Demand for road...

  13. Influenza vaccination for immunocompromised patients: systematic review and meta-analysis from a public health policy perspective.

    Directory of Open Access Journals (Sweden)

    Charles R Beck

    Full Text Available BACKGROUND: Immunocompromised patients are vulnerable to severe or complicated influenza infection. Vaccination is widely recommended for this group. This systematic review and meta-analysis assesses influenza vaccination for immunocompromised patients in terms of preventing influenza-like illness and laboratory confirmed influenza, serological response and adverse events. METHODOLOGY/PRINCIPAL FINDINGS: Electronic databases and grey literature were searched and records were screened against eligibility criteria. Data extraction and risk of bias assessments were performed in duplicate. Results were synthesised narratively and meta-analyses were conducted where feasible. Heterogeneity was assessed using I(2 and publication bias was assessed using Begg's funnel plot and Egger's regression test. Many of the 209 eligible studies included an unclear or high risk of bias. Meta-analyses showed a significant effect of preventing influenza-like illness (odds ratio [OR]=0.23; 95% confidence interval [CI]=0.16-0.34; p<0.001 and laboratory confirmed influenza infection (OR=0.15; 95% CI=0.03-0.63; p=0.01 through vaccinating immunocompromised patie nts compared to placebo or unvaccinated controls. We found no difference in the odds of influenza-like illness compared to vaccinated immunocompetent controls. The pooled odds of seroconversion were lower in vaccinated patients compared to immunocompetent controls for seasonal influenza A(H1N1, A(H3N2 and B. A similar trend was identified for seroprotection. Meta-analyses of seroconversion showed higher odds in vaccinated patients compared to placebo or unvaccinated controls, although this reached significance for influenza B only. Publication bias was not detected and narrative synthesis supported our findings. No consistent evidence of safety concerns was identified. CONCLUSIONS/SIGNIFICANCE: Infection prevention and control strategies should recommend vaccinating immunocompromised patients. Potential for bias

  14. Estimation and correction of different flavors of surface observation biases in ensemble Kalman filter

    Science.gov (United States)

    Lorente-Plazas, Raquel; Hacker, Josua P.; Collins, Nancy; Lee, Jared A.

    2017-04-01

    The impact of assimilating surface observations has been shown in several publications, for improving weather prediction inside of the boundary layer as well as the flow aloft. However, the assimilation of surface observations is often far from optimal due to the presence of both model and observation biases. The sources of these biases can be diverse: an instrumental offset, errors associated to the comparison of point-based observations and grid-cell average, etc. To overcome this challenge, a method was developed using the ensemble Kalman filter. The approach consists on representing each observation bias as a parameter. These bias parameters are added to the forward operator and they extend the state vector. As opposed to the observation bias estimation approaches most common in operational systems (e.g. for satellite radiances), the state vector and parameters are simultaneously updated by applying the Kalman filter equations to the augmented state. The method to estimate and correct the observation bias is evaluated using observing system simulation experiments (OSSEs) with the Weather Research and Forecasting (WRF) model. OSSEs are constructed for the conventional observation network including radiosondes, aircraft observations, atmospheric motion vectors, and surface observations. Three different kinds of biases are added to 2-meter temperature for synthetic METARs. From the simplest to more sophisticated, imposed biases are: (1) a spatially invariant bias, (2) a spatially varying bias proportional to topographic height differences between the model and the observations, and (3) bias that is proportional to the temperature. The target region characterized by complex terrain is the western U.S. on a domain with 30-km grid spacing. Observations are assimilated every 3 hours using an 80-member ensemble during September 2012. Results demonstrate that the approach is able to estimate and correct the bias when it is spatially invariant (experiment 1). More

  15. Analysing immune cell migration.

    Science.gov (United States)

    Beltman, Joost B; Marée, Athanasius F M; de Boer, Rob J

    2009-11-01

    The visualization of the dynamic behaviour of and interactions between immune cells using time-lapse video microscopy has an important role in modern immunology. To draw robust conclusions, quantification of such cell migration is required. However, imaging experiments are associated with various artefacts that can affect the estimated positions of the immune cells under analysis, which form the basis of any subsequent analysis. Here, we describe potential artefacts that could affect the interpretation of data sets on immune cell migration. We propose how these errors can be recognized and corrected, and suggest ways to prevent the data analysis itself leading to biased results.

  16. The removal of multiplicative, systematic bias allows integration of breast cancer gene expression datasets – improving meta-analysis and prediction of prognosis

    Directory of Open Access Journals (Sweden)

    Pepper Stuart D

    2008-09-01

    Full Text Available Abstract Background The number of gene expression studies in the public domain is rapidly increasing, representing a highly valuable resource. However, dataset-specific bias precludes meta-analysis at the raw transcript level, even when the RNA is from comparable sources and has been processed on the same microarray platform using similar protocols. Here, we demonstrate, using Affymetrix data, that much of this bias can be removed, allowing multiple datasets to be legitimately combined for meaningful meta-analyses. Results A series of validation datasets comparing breast cancer and normal breast cell lines (MCF7 and MCF10A were generated to examine the variability between datasets generated using different amounts of starting RNA, alternative protocols, different generations of Affymetrix GeneChip or scanning hardware. We demonstrate that systematic, multiplicative biases are introduced at the RNA, hybridization and image-capture stages of a microarray experiment. Simple batch mean-centering was found to significantly reduce the level of inter-experimental variation, allowing raw transcript levels to be compared across datasets with confidence. By accounting for dataset-specific bias, we were able to assemble the largest gene expression dataset of primary breast tumours to-date (1107, from six previously published studies. Using this meta-dataset, we demonstrate that combining greater numbers of datasets or tumours leads to a greater overlap in differentially expressed genes and more accurate prognostic predictions. However, this is highly dependent upon the composition of the datasets and patient characteristics. Conclusion Multiplicative, systematic biases are introduced at many stages of microarray experiments. When these are reconciled, raw data can be directly integrated from different gene expression datasets leading to new biological findings with increased statistical power.

  17. The use of interim data and Data Monitoring Committee recommendations in randomized controlled trial reports: frequency, implications and potential sources of bias

    Directory of Open Access Journals (Sweden)

    Hampton John

    2008-03-01

    Full Text Available Abstract Background Interim analysis of accumulating trial data is important to protect participant safety during randomized controlled trials (RCTs. Data Monitoring Committees (DMCs often undertake such analyses, but their widening role may lead to extended use of interim analysis or recommendations that could potentially bias trial results. Methods Systematic search of eight major publications: Annals of Internal Medicine, BMJ, Circulation, CID, JAMA, JCO, Lancet and NEJM, including all randomised controlled trials (RCTs between June 2000 and May 2005 to identify RCTs that reported use of interim analysis, with or without DMC involvement. Recommendations made by the DMC or based on interim analysis were identified and potential sources of bias assessed. Independent double data extraction was performed on all included trials. Results We identified 1772 RCTs, of which 470 (27%; 470/1772 reported the use of a DMC and a further 116 (7%; 116/1772 trials reported some form of interim analysis without explicit mention of a DMC. There were 28 trials (24 with a formal DMC, randomizing a total of 79396 participants, identified as recommending changes to the trial that may have lead to biased results. In most of these, some form of sample size re-estimation was recommended with four trials also reporting changes to trial endpoints. The review relied on information reported in the primary publications and methods papers relating to the trials, higher rates of use may have occurred but not been reported. Conclusion The reported use of interim analysis and DMCs in clinical trials has been increasing in recent years. It is reassuring that in most cases recommendations were made in the interest of participant safety. However, in practice, recommendations that may lead to potentially biased trial results are being made.

  18. Introduction of EDI in the public sector

    DEFF Research Database (Denmark)

    Falch, Morten

    1997-01-01

    Reviews the status of EDI in the sectors of health, public transport and taxation and public administration. The impact of this on the diffusion of EDI in other sectors is analysed.......Reviews the status of EDI in the sectors of health, public transport and taxation and public administration. The impact of this on the diffusion of EDI in other sectors is analysed....

  19. Assessing bias in osteoarthritis trials included in Cochrane reviews

    DEFF Research Database (Denmark)

    Hansen, Julie Bolvig; Juhl, Carsten Bogh; Boutron, Isabelle

    2014-01-01

    INTRODUCTION: The validity of systematic reviews and meta-analysis depends on methodological quality and unbiased dissemination of trials. Our objective is to evaluate the association of estimates of treatment effects with different bias-related study characteristics in meta-analyses of intervent......INTRODUCTION: The validity of systematic reviews and meta-analysis depends on methodological quality and unbiased dissemination of trials. Our objective is to evaluate the association of estimates of treatment effects with different bias-related study characteristics in meta......-analyses of interventions used for treating pain in osteoarthritis (OA). From the findings, we hope to consolidate guidance on interpreting OA trials in systematic reviews based on empirical evidence from Cochrane reviews. METHODS AND ANALYSIS: Only systematic reviews that compare experimental interventions with sham...... the first appearing forest plot for overall pain in the Cochrane review. Treatment effect sizes will be expressed as standardised mean differences (SMDs), where the difference in mean values available from the forest plots is divided by the pooled SD. To empirically assess the risk of bias in treatment...

  20. Biased random walks on multiplex networks

    CERN Document Server

    Battiston, Federico; Latora, Vito

    2015-01-01

    Biased random walks on complex networks are a particular type of walks whose motion is biased on properties of the destination node, such as its degree. In recent years they have been exploited to design efficient strategies to explore a network, for instance by constructing maximally mixing trajectories or by sampling homogeneously the nodes. In multiplex networks, the nodes are related through different types of links (layers or communication channels), and the presence of connections at different layers multiplies the number of possible paths in the graph. In this work we introduce biased random walks on multiplex networks and provide analytical solutions for their long-term properties such as the stationary distribution and the entropy rate. We focus on degree-biased walks and distinguish between two subclasses of random walks: extensive biased walks consider the properties of each node separately at each layer, intensive biased walks deal instead with intrinsically multiplex variables. We study the effec...

  1. Symmetry as Bias: Rediscovering Special Relativity

    Science.gov (United States)

    Lowry, Michael R.

    1992-01-01

    This paper describes a rational reconstruction of Einstein's discovery of special relativity, validated through an implementation: the Erlanger program. Einstein's discovery of special relativity revolutionized both the content of physics and the research strategy used by theoretical physicists. This research strategy entails a mutual bootstrapping process between a hypothesis space for biases, defined through different postulated symmetries of the universe, and a hypothesis space for physical theories. The invariance principle mutually constrains these two spaces. The invariance principle enables detecting when an evolving physical theory becomes inconsistent with its bias, and also when the biases for theories describing different phenomena are inconsistent. Structural properties of the invariance principle facilitate generating a new bias when an inconsistency is detected. After a new bias is generated. this principle facilitates reformulating the old, inconsistent theory by treating the latter as a limiting approximation. The structural properties of the invariance principle can be suitably generalized to other types of biases to enable primal-dual learning.

  2. Sproglig Metode og Analyse

    DEFF Research Database (Denmark)

    le Fevre Jakobsen, Bjarne

    Publikationen indeholder øvematerialer, tekster, powerpointpræsentationer og handouts til undervisningsfaget Sproglig Metode og Analyse på BA og tilvalg i Dansk/Nordisk 2010-2011......Publikationen indeholder øvematerialer, tekster, powerpointpræsentationer og handouts til undervisningsfaget Sproglig Metode og Analyse på BA og tilvalg i Dansk/Nordisk 2010-2011...

  3. Public Values

    DEFF Research Database (Denmark)

    Beck Jørgensen, Torben; Rutgers, Mark R.

    2015-01-01

    administration is approached in terms of processes guided or restricted by public values and as public value creating: public management and public policy-making are both concerned with establishing, following and realizing public values. To study public values a broad perspective is needed. The article suggest......This article provides the introduction to a symposium on contemporary public values research. It is argued that the contribution to this symposium represent a Public Values Perspective, distinct from other specific lines of research that also use public value as a core concept. Public...... a research agenda for this encompasing kind of public values research. Finally the contributions to the symposium are introduced....

  4. Behavioral experiments on biased voting in networks.

    Science.gov (United States)

    Kearns, Michael; Judd, Stephen; Tan, Jinsong; Wortman, Jennifer

    2009-02-03

    Many distributed collective decision-making processes must balance diverse individual preferences with a desire for collective unity. We report here on an extensive session of behavioral experiments on biased voting in networks of individuals. In each of 81 experiments, 36 human subjects arranged in a virtual network were financially motivated to reach global consensus to one of two opposing choices. No payments were made unless the entire population reached a unanimous decision within 1 min, but different subjects were paid more for consensus to one choice or the other, and subjects could view only the current choices of their network neighbors, thus creating tensions between private incentives and preferences, global unity, and network structure. Along with analyses of how collective and individual performance vary with network structure and incentives generally, we find that there are well-studied network topologies in which the minority preference consistently wins globally; that the presence of "extremist" individuals, or the awareness of opposing incentives, reliably improve collective performance; and that certain behavioral characteristics of individual subjects, such as "stubbornness," are strongly correlated with earnings.

  5. Political Accountability, Electoral Control, and Media Bias

    OpenAIRE

    Adachi, Takanori; Hizen, Yoichi

    2012-01-01

    Are anti-establishment mass media really useful in preventing politicians from behaving dishonestly? This paper proposes a voting model for analyzing how differences in the direction of media bias affect politicians' behavior. In particular, the probability of corruption by an incumbent is higher (than that in the case of no media bias) if and only if the mass media have some degree of "anti-incumbent" bias (i.e., information favorable to the incumbent is converted into unfavorable news about...

  6. Electric control of exchange bias training.

    Science.gov (United States)

    Echtenkamp, W; Binek, Ch

    2013-11-01

    Voltage-controlled exchange bias training and tunability are introduced. Isothermal voltage pulses are used to reverse the antiferromagnetic order parameter of magnetoelectric Cr(2)O(3), and thus continuously tune the exchange bias of an adjacent CoPd film. Voltage-controlled exchange bias training is initialized by tuning the antiferromagnetic interface into a nonequilibrium state incommensurate with the underlying bulk. Interpretation of these hitherto unreported effects contributes to new understanding in electrically controlled magnetism.

  7. Electric Control of Exchange Bias Training

    Science.gov (United States)

    Echtenkamp, W.; Binek, Ch.

    2013-11-01

    Voltage-controlled exchange bias training and tunability are introduced. Isothermal voltage pulses are used to reverse the antiferromagnetic order parameter of magnetoelectric Cr2O3, and thus continuously tune the exchange bias of an adjacent CoPd film. Voltage-controlled exchange bias training is initialized by tuning the antiferromagnetic interface into a nonequilibrium state incommensurate with the underlying bulk. Interpretation of these hitherto unreported effects contributes to new understanding in electrically controlled magnetism.

  8. When Do Children Exhibit a "Yes" Bias?

    Science.gov (United States)

    Okanda, Mako; Itakura, Shoji

    2010-01-01

    This study investigated whether one hundred and thirty-five 3- to 6-year-old children exhibit a yes bias to various yes-no questions and whether their knowledge status affects the production of a yes bias. Three-year-olds exhibited a yes bias to all yes-no questions such as "preference-object" and "knowledge-object" questions pertaining to…

  9. 公众对地方政府土地生态行政认知的调查和分析——以L市为例%Investigations and Analyses of Public Recognition of Local Government's Ecological Land Administration

    Institute of Scientific and Technical Information of China (English)

    郭春华; 姜楠

    2012-01-01

    The differences in land use and management objectives between the central government and local government have caused problems to some local governments in land ecological administration. By conducting a public investigation in a city in the form of questionnaire and interview, this paper finds out the impact factors in land ecological administration through factor analysis, analyzes the problems of land ecological administration in local government, and then puts forward the corresponding proposals, providing a reference for local government to enhance sustainable land use and management and to ensure socio-economic sustainable development and environmental protection.%由于中央政府和地方政府土地利用及其管理目标的差异性,导致部分地方政府在土地生态行政的过程中存在相关问题.通过问卷调查和访谈的方式对L市公众进行了调查,运用因子分析找出土地生态行政认知的影响因素,深入分析地方政府土地生态行政问题,进而提出完善地方政府土地生态行政的相关对策建议,为地方政府加强土地可持续利用与管理,确保社会经济持续发展和保护土地生态环境提供参考.

  10. Model parameter estimation bias induced by earthquake magnitude cut-off

    Science.gov (United States)

    Harte, D. S.

    2016-02-01

    We evaluate the bias in parameter estimates of the ETAS model. We show that when a simulated catalogue is magnitude-truncated there is considerable bias, whereas when it is not truncated there is no discernible bias. We also discuss two further implied assumptions in the ETAS and other self-exciting models. First, that the triggering boundary magnitude is equivalent to the catalogue completeness magnitude. Secondly, the assumption in the Gutenberg-Richter relationship that numbers of events increase exponentially as magnitude decreases. These two assumptions are confounded with the magnitude truncation effect. We discuss the effect of these problems on analyses of real earthquake catalogues.

  11. Guidelines for reducing bias in nursing examinations.

    Science.gov (United States)

    Klisch, M L

    1994-01-01

    As our nation becomes more diversified, many schools of nursing strive to improve the recruitment and retention of English as a Second Language (ESL) and minority nursing students. An important aspect of this commitment to diversity is the reduction of biased items in nursing examinations, with the goal of making the evaluation process fair for all students. The author defines test and item bias, provides examples of biased items, and presents specific guidelines for decreasing item bias in teacher-made nursing examinations. A discussion of the related topic of whether ESL students should be given extended testing time is included.

  12. Bayesian long branch attraction bias and corrections.

    Science.gov (United States)

    Susko, Edward

    2015-03-01

    Previous work on the star-tree paradox has shown that Bayesian methods suffer from a long branch attraction bias. That work is extended to settings involving more taxa and partially resolved trees. The long branch attraction bias is confirmed to arise more broadly and an additional source of bias is found. A by-product of the analysis is methods that correct for biases toward particular topologies. The corrections can be easily calculated using existing Bayesian software. Posterior support for a set of two or more trees can thus be supplemented with corrected versions to cross-check or replace results. Simulations show the corrections to be highly effective.

  13. Attribution bias and social anxiety in schizophrenia

    Directory of Open Access Journals (Sweden)

    Amelie M. Achim

    2016-06-01

    Full Text Available Studies on attribution biases in schizophrenia have produced mixed results, whereas such biases have been more consistently reported in people with anxiety disorders. Anxiety comorbidities are frequent in schizophrenia, in particular social anxiety disorder, which could influence their patterns of attribution biases. The objective of the present study was thus to determine if individuals with schizophrenia and a comorbid social anxiety disorder (SZ+ show distinct attribution biases as compared with individuals with schizophrenia without social anxiety (SZ− and healthy controls. Attribution biases were assessed with the Internal, Personal, and Situational Attributions Questionnaire in 41 individual with schizophrenia and 41 healthy controls. Results revealed the lack of the normal externalizing bias in SZ+, whereas SZ− did not significantly differ from healthy controls on this dimension. The personalizing bias was not influenced by social anxiety but was in contrast linked with delusions, with a greater personalizing bias in individuals with current delusions. Future studies on attribution biases in schizophrenia should carefully document symptom presentation, including social anxiety.

  14. Meta-analyses of the 5-HTTLPR polymorphisms and post-traumatic stress disorder.

    Directory of Open Access Journals (Sweden)

    Fernando Navarro-Mateu

    Full Text Available OBJECTIVE: To conduct a meta-analysis of all published genetic association studies of 5-HTTLPR polymorphisms performed in PTSD cases. METHODS DATA SOURCES: Potential studies were identified through PubMed/MEDLINE, EMBASE, Web of Science databases (Web of Knowledge, WoK, PsychINFO, PsychArticles and HuGeNet (Human Genome Epidemiology Network up until December 2011. STUDY SELECTION: Published observational studies reporting genotype or allele frequencies of this genetic factor in PTSD cases and in non-PTSD controls were all considered eligible for inclusion in this systematic review. DATA EXTRACTION: Two reviewers selected studies for possible inclusion and extracted data independently following a standardized protocol. STATISTICAL ANALYSIS: A biallelic and a triallelic meta-analysis, including the total S and S' frequencies, the dominant (S+/LL and S'+/L'L' and the recessive model (SS/L+ and S'S'/L'+, was performed with a random-effect model to calculate the pooled OR and its corresponding 95% CI. Forest plots and Cochran's Q-Statistic and I(2 index were calculated to check for heterogeneity. Subgroup analyses and meta-regression were carried out to analyze potential moderators. Publication bias and quality of reporting were also analyzed. RESULTS: 13 studies met our inclusion criteria, providing a total sample of 1874 patients with PTSD and 7785 controls in the biallelic meta-analyses and 627 and 3524, respectively, in the triallelic. None of the meta-analyses showed evidence of an association between 5-HTTLPR and PTSD but several characteristics (exposure to the same principal stressor for PTSD cases and controls, adjustment for potential confounding variables, blind assessment, study design, type of PTSD, ethnic distribution and Total Quality Score influenced the results in subgroup analyses and meta-regression. There was no evidence of potential publication bias. CONCLUSIONS: Current evidence does not support a direct effect of 5-HTTLPR

  15. Publication and Quality of Systematic Reviews/Meta-Analyses Conducted by Hospital Pharmacists in China%国内医院药学人员系统评价/Meta分析文献发表与质量研究

    Institute of Scientific and Technical Information of China (English)

    闫盈盈; 易湛苗; 翟所迪

    2012-01-01

    Objective Through assessing the quality of systematic reviews/meta-analyses conducted by hospital pharmacists in China, to learn relevant situations and to promote the development and application of evidence-based pharmacy in hospital. Methods The following databases such as CBM, CNKI, Wanfang Database, VIP, CMCI, The Cochrane Library, Embase and PubMed were searched from the establishment date to April 15th, 2011, to collect all published systematic reviews/meta-analyses conducted by hospital pharmacists in China. Two reviewers independently extracted the published information according to the inclusive and exclusive criteria, and assessed the methodology and reporting quality of the included literatures with OQAQ and PRISMA. Disagreements were discussed or resolved by the third reviewer. Data analysis was conducted by using SPSS 17.0 software. Results Two hundred and sixteen Chinese literatures (including 40 on traditional Chinese medicine), and 15 English literatures were identified. The number of literatures has increased rapidly since 2008. Beijing and Sichuan were the top 2 districts in the number of literatures. All of the included literatures were published in 62 magazines sponsored by 87 hospitals, such as China Pharmacy, and Chinese Journey of Evidence-Based Medicine. The total downloads of Chinese literatures were 14346, and the total citations of all literatures were 154. The methodology and reporting quality of the randomized controlled trials (RCTs) involved in 220 systematic reviews/meta-analyses literatures were assessed, which showed the highest and lowest scores of methodological quality were 6 and 3, respectively, and the average score was 4.27±0.55. The highest and lowest scores of reporting quality were 22.5 and 9, respectively, and the average score was 16.49±2.98. Conclusion Although the evidence-based pharmacy in hospital begins late in China, it develops rapidly, and offers lots of evidence to policy decision, guidelines and rational drug

  16. Evidence for the selective reporting of analyses and discrepancies in clinical trials: a systematic review of cohort studies of clinical trials.

    Directory of Open Access Journals (Sweden)

    Kerry Dwan

    2014-06-01

    Full Text Available Most publications about selective reporting in clinical trials have focussed on outcomes. However, selective reporting of analyses for a given outcome may also affect the validity of findings. If analyses are selected on the basis of the results, reporting bias may occur. The aims of this study were to review and summarise the evidence from empirical cohort studies that assessed discrepant or selective reporting of analyses in randomised controlled trials (RCTs.A systematic review was conducted and included cohort studies that assessed any aspect of the reporting of analyses of RCTs by comparing different trial documents, e.g., protocol compared to trial report, or different sections within a trial publication. The Cochrane Methodology Register, Medline (Ovid, PsycInfo (Ovid, and PubMed were searched on 5 February 2014. Two authors independently selected studies, performed data extraction, and assessed the methodological quality of the eligible studies. Twenty-two studies (containing 3,140 RCTs published between 2000 and 2013 were included. Twenty-two studies reported on discrepancies between information given in different sources. Discrepancies were found in statistical analyses (eight studies, composite outcomes (one study, the handling of missing data (three studies, unadjusted versus adjusted analyses (three studies, handling of continuous data (three studies, and subgroup analyses (12 studies. Discrepancy rates varied, ranging from 7% (3/42 to 88% (7/8 in statistical analyses, 46% (36/79 to 82% (23/28 in adjusted versus unadjusted analyses, and 61% (11/18 to 100% (25/25 in subgroup analyses. This review is limited in that none of the included studies investigated the evidence for bias resulting from selective reporting of analyses. It was not possible to combine studies to provide overall summary estimates, and so the results of studies are discussed narratively.Discrepancies in analyses between publications and other study documentation

  17. How Do Biases in General Circulation Models Affect Projections of Aridity and Drought?

    Science.gov (United States)

    Ficklin, D. L.; Abatzoglou, J. T.; Robeson, S. M.; Dufficy, A. L.

    2015-12-01

    Unless corrected, biases in General Circulation Models (GCMs) can affect hydroclimatological applications and projections. Compared to a raw GCM ensemble (direct GCM output), bias-corrected GCM inputs correct for systematic errors and can produce high-resolution projections that are useful for impact analyses. By examining the difference between raw and bias-corrected GCMs for the continental United States, this work highlights how GCM biases can affect projections of aridity (defined as precipitation (P)/potential evapotranspiration (PET)) and drought (using the Palmer Drought Severity Index (PDSI)). At the annual time scale for spatial averages over the continental United States, the raw GCM ensemble median has a historical positive precipitation bias (+24%) and negative PET bias (-7%) compared to the bias-corrected output. While both GCM ensembles (raw and bias-corrected) result in drier conditions in the future, the bias-corrected GCMs produce enhanced aridity (number of months with PET>P) in the late 21st century (2070-2099) compared to the historical climate (1950-1979). For the western United States, the bias-corrected GCM ensemble estimates much less humid and sub-humid conditions (based on P/PET categorical values) than the raw GCM ensemble. However, using June, July, and August PDSI, the bias-corrected GCM ensemble projects less acute decreases for the southwest United States compared to the raw GCM ensemble (1 to 2 PDSI units higher) as a result of larger decreases in projected precipitation in the raw GCM ensemble. A number of examples and ecological implications of this work for the western United States will be presented.

  18. Ascertainment biases in SNP chips affect measures of population divergence

    DEFF Research Database (Denmark)

    Albrechtsen, Anders; Nielsen, Finn Cilius; Nielsen, Rasmus

    2010-01-01

    Chip-based high-throughput genotyping has facilitated genome-wide studies of genetic diversity. Many studies have utilized these large data sets to make inferences about the demographic history of human populations using measures of genetic differentiation such as F(ST) or principal component...... analyses. However, the single nucleotide polymorphism (SNP) chip data suffer from ascertainment biases caused by the SNP discovery process in which a small number of individuals from selected populations are used as discovery panels. In this study, we investigate the effect of the ascertainment bias...... on inferences regarding genetic differentiation among populations in one of the common genome-wide genotyping platforms. We generate SNP genotyping data for individuals that previously have been subject to partial genome-wide Sanger sequencing and compare inferences based on genotyping data to inferences based...

  19. Reward sensitivity predicts ice cream-related attentional bias assessed by inattentional blindness.

    Science.gov (United States)

    Li, Xiaoming; Tao, Qian; Fang, Ya; Cheng, Chen; Hao, Yangyang; Qi, Jianjun; Li, Yu; Zhang, Wei; Wang, Ying; Zhang, Xiaochu

    2015-06-01

    The cognitive mechanism underlying the association between individual differences in reward sensitivity and food craving is unknown. The present study explored the mechanism by examining the role of reward sensitivity in attentional bias toward ice cream cues. Forty-nine college students who displayed high level of ice cream craving (HICs) and 46 who displayed low level of ice cream craving (LICs) performed an inattentional blindness (IB) task which was used to assess attentional bias for ice cream. In addition, reward sensitivity and coping style were assessed by the Behavior Inhibition System/Behavior Activation System Scales and Simplified Coping Style Questionnaire. Results showed significant higher identification rate of the critical stimulus in the HICs than LICs, suggesting greater attentional bias for ice cream in the HICs. It was indicated that attentional bias for food cues persisted even under inattentional condition. Furthermore, a significant correlation was found between the attentional bias and reward sensitivity after controlling for coping style, and reward sensitivity predicted attentional bias for food cues. The mediation analyses showed that attentional bias mediated the relationship between reward sensitivity and food craving. Those findings suggest that the association between individual differences in reward sensitivity and food craving may be attributed to attentional bias for food-related cues.

  20. Female philopatry and male-biased dispersal in a direct-developing salamander, Plethodon cinereus.

    Science.gov (United States)

    Liebgold, Eric B; Brodie, Edmund D; Cabe, Paul R

    2011-01-01

    The local resource competition hypothesis and the local mate competition hypothesis were developed based on avian and mammalian systems to explain sex-biased dispersal. Most avian species show a female bias in dispersal, ostensibly due to resource defence, and most mammals show a male bias, ostensibly due to male-male competition. These findings confound phylogeny with mating strategy; little is known about sex-biased dispersal in other taxa. Resource defence and male-male competition are both intense in Plethodon cinereus, a direct-developing salamander, so we tested whether sex-biased dispersal in this amphibian is consistent with the local resource competition hypothesis (female-biased) or the local mate competition hypothesis (male-biased). Using fine-scale genetic spatial autocorrelation analyses, we found that females were philopatric, showing significant positive genetic structure in the shortest distance classes, with stronger patterns apparent when only territorial females were tested. Males showed no spatial genetic structure over the shortest distances. Mark-recapture observations of P. cinereus over 5 years were consistent with the genetic data: males dispersed farther than females during natal dispersal and 44% of females were recaptured within 1 m of their juvenile locations. We conclude that, in this population of a direct-developing amphibian, females are philopatric and dispersal is male-biased, consistent with the local mate competition hypothesis. © 2010 Blackwell Publishing Ltd.

  1. Understanding Thermal Activation Processes in Exchange Bias Systems

    Science.gov (United States)

    O'Grady, Kevin

    2007-03-01

    The phenomenon of exchange bias has been of major scientific interest and technological importance since the 1980s following its discovery by Meiklejohn and Bean in 1956 [1,2]. Following initial seminal work by Fulcomer and Charap [3] it has recently become clear that a major contribution to the phenomena of exchange bias derives from the fact that the grains in the antiferromagnetic (AF) layer are capable of thermally activated reorientation due to the exchange field from the ferromagnetic (F) layer. In this work careful measurement protocols will be presented that enable the thermal activation process to be analysed in considerable detail. More recently Hoffman [4] has described a spin reorientation process that occurs after the AF layer is set which leads to a large shift in the forward going hysteresis loop on the first reversal of the F layer. This effect, coupled to the thermal activation process, gives rise to the phenomenon of training whereby the loop progressively shifts from its original set direction towards the origin. Lastly we have observed a spin freezing phenomena at the interface that can be induced by either temperature or applied field which results in a systematic variation of the exchange bias. We interpret this effect as being due to paramagnetic like spins at the interface whose ordering leads to a significant increase in the overall value of the exchange bias. Thus we show that exchange bias is a complex convolution of at least three distinct effects, all of which will be described in detail. This explains why single theories of how this effect arises have been so unsuccessful during the last 50 years. [1] Meiklejohn and Bean: Physical Review vol.102 p.1413 (1956) [2] Nogues and Schuller: Journal of Magnetism and Magnetic Materials vol.192 p.203 (1999) [3] Fulcomer and Charap: Journal of Applied Physics vol.43 p.4190 (1972) [4] Hoffmann: Physical Review Letters vol.93 p.097203 (2004)

  2. Public Undertakings and Imputability

    DEFF Research Database (Denmark)

    Ølykke, Grith Skovgaard

    2013-01-01

    in Article 107(1) TFEU is analysed. It is concluded that where the public undertaking transgresses the control system put in place by the State, conditions for imputability are not fulfilled, and it is argued that in the current state of law, there is no conditional link between the level of control...... that this is not the case. Lastly, it is discussed whether other legal instruments, namely competition law, public procurement law, or the Transparency Directive, regulate public undertakings’ market behaviour. It is found that those rules are not sufficient to mend the gap created by the imputability requirement. Legal......In this article, the issue of impuability to the State of public undertakings’ decision-making is analysed and discussed in the context of the DSBFirst case. DSBFirst is owned by the independent public undertaking DSB and the private undertaking FirstGroup plc and won the contracts in the 2008...

  3. Pharmacogenomics Bias - Systematic distortion of study results by genetic heterogeneity

    Directory of Open Access Journals (Sweden)

    Zietemann, Vera

    2008-04-01

    Full Text Available Background: Decision analyses of drug treatments in chronic diseases require modeling the progression of disease and treatment response beyond the time horizon of clinical or epidemiological studies. In many such models, progression and drug effect have been applied uniformly to all patients; heterogeneity in progression, including pharmacogenomic effects, has been ignored. Objective: We sought to systematically evaluate the existence, direction and relative magnitude of a pharmacogenomics bias (PGX-Bias resulting from failure to adjust for genetic heterogeneity in both treatment response (HT and heterogeneity in progression of disease (HP in decision-analytic studies based on clinical study data. Methods: We performed a systematic literature search in electronic databases for studies regarding the effect of genetic heterogeneity on the validity of study results. Included studies have been summarized in evidence tables. In the case of lacking evidence from published studies we sought to perform our own simulation considering both HT and HP. We constructed two simple Markov models with three basic health states (early-stage disease, late-stage disease, dead, one adjusting and the other not adjusting for genetic heterogeneity. Adjustment was done by creating different disease states for presence (G+ and absence (G- of a dichotomous genetic factor. We compared the life expectancy gains attributable to treatment resulting from both models and defined pharmacogenomics bias as percent deviation of treatment-related life expectancy gains in the unadjusted model from those in the adjusted model. We calculated the bias as a function of underlying model parameters to create generic results. We then applied our model to lipid-lowering therapy with pravastatin in patients with coronary atherosclerosis, incorporating the influence of two TaqIB polymorphism variants (B1 and B2 on progression and drug efficacy as reported in the DNA substudy of the REGRESS

  4. Strategies to improve the credibility of meta-analyses in spine surgery: a systematic survey.

    Science.gov (United States)

    Evaniew, Nathan; van der Watt, Leon; Bhandari, Mohit; Ghert, Michelle; Aleem, Ilyas; Drew, Brian; Guyatt, Gordon

    2015-09-01

    Meta-analyses are powerful tools that can synthesize existing research, inform clinical practice, and support evidence-based care. These studies have become increasingly popular in the spine surgery literature, but the rigor with which they are being conducted has not yet been evaluated. Our primary objectives were to evaluate the methodological quality (credibility) of spine surgery meta-analyses and to propose strategies to improve future research. Our secondary objectives were to evaluate completeness of reporting and identify factors associated with higher credibility and completeness of reporting. This study is based on a systematic survey of meta-analyses. We evaluated credibility according to the Users' Guide to the Medical Literature and completeness of reporting according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. We systematically searched MEDLINE, EMBASE, and The Cochrane Library, and two reviewers independently assessed eligibility, credibility, and completeness of reporting. We used multivariable linear regression to evaluate potential associations. Interrater agreement was quantified using kappa and intraclass correlation (ICC) coefficients. We identified 132 eligible meta-analyses of spine surgery interventions. The mean credibility score was 3 of 7 (standard deviation [SD], 1.4; ICC, 0.86), with agreement for each item ranging from 0.54 (moderate) to 0.83 (almost perfect). Clinical questions were judged as sensible in 125 (95%), searches were exhaustive in 102 (77%), and risk of bias assessments were undertaken in 91 (69%). Seven (5%) meta-analyses addressed possible explanations for heterogeneity using a priori subgroup hypotheses and 24 (18%) presented results that were immediately clinically applicable. Investigators undertook duplicate assessments of eligibility, risk of bias, and data extraction in 46 (35%) and rated overall confidence in the evidence in 24 (18%). Later publication year, increasing

  5. Overweight people have low levels of implicit weight bias, but overweight nations have high levels of implicit weight bias.

    Directory of Open Access Journals (Sweden)

    Maddalena Marini

    Full Text Available Although a greater degree of personal obesity is associated with weaker negativity toward overweight people on both explicit (i.e., self-report and implicit (i.e., indirect behavioral measures, overweight people still prefer thin people on average. We investigated whether the national and cultural context - particularly the national prevalence of obesity - predicts attitudes toward overweight people independent of personal identity and weight status. Data were collected from a total sample of 338,121 citizens from 71 nations in 22 different languages on the Project Implicit website (https://implicit.harvard.edu/ between May 2006 and October 2010. We investigated the relationship of the explicit and implicit weight bias with the obesity both at the individual (i.e., across individuals and national (i.e., across nations level. Explicit weight bias was assessed with self-reported preference between overweight and thin people; implicit weight bias was measured with the Implicit Association Test (IAT. The national estimates of explicit and implicit weight bias were obtained by averaging the individual scores for each nation. Obesity at the individual level was defined as Body Mass Index (BMI scores, whereas obesity at the national level was defined as three national weight indicators (national BMI, national percentage of overweight and underweight people obtained from publicly available databases. Across individuals, greater degree of obesity was associated with weaker implicit negativity toward overweight people compared to thin people. Across nations, in contrast, a greater degree of national obesity was associated with stronger implicit negativity toward overweight people compared to thin people. This result indicates a different relationship between obesity and implicit weight bias at the individual and national levels.

  6. Evaluating Judicial Performance and Addressing Gender Bias

    Directory of Open Access Journals (Sweden)

    Angela Melville

    2014-12-01

    Full Text Available Elek and Rottman argue that judicial evaluation is often biased against women and minority judges. The need to address bias is important, however often the desire for diversity seems so self-evident as to belie deeper analysis. This paper examines the two main rationales for gender equality on the bench. First, female judges are often considered necessary in order to bring a gendered perspective to judging, however it is argued that this rationale is flawed. Second, an alternative rationale based on equality and legitimacy is offered which avoids gender essentialism. While debates typically focus on these two rationales, a third rationale embraces both difference and equality/legitimacy. The presence of female judges has an important symbolic value which destabilises existing fraternal legal norms. Finally, increasing the number of female judges may not necessarily change judging, and this paper also analyses how the transformative potential offered by judicial diversity can work in practice. Elek y Rottman defienden que la evaluación judicial suele estar sesgada en contra de las mujeres y los jueces pertenecientes a minorías. La necesidad de abordar el sesgo es importante, sin embargo a menudo el deseo de diversidad parece tan evidente como para contradecir un análisis más profundo. Este artículo examina los dos motivos principales para la igualdad de género en el banquillo. En primer lugar, las mujeres jueces a menudo se consideran necesarias para aportar una perspectiva de género al hecho de juzgar, sin embargo, se defiende que este razonamiento es erróneo. En segundo lugar, se ofrece una alternativa lógica basada en la igualdad y la legitimidad que evita el esencialismo de género. Mientras que los debates suelen centrarse en estas dos razones, una tercera justificación abarca tanto la diferencia como la igualdad/legitimidad. La presencia de mujeres en la judicatura tiene un importante valor simbólico que desestabiliza las normas

  7. Zero-bias spin separation

    Science.gov (United States)

    Ganichev, Sergey D.; Bel'Kov, Vasily V.; Tarasenko, Sergey A.; Danilov, Sergey N.; Giglberger, Stephan; Hoffmann, Christoph; Ivchenko, Eougenious L.; Weiss, Dieter; Wegscheider, Werner; Gerl, Christian; Schuh, Dieter; Stahl, Joachim; de Boeck, Jo; Borghs, Gustaaf; Prettl, Wilhelm

    2006-09-01

    The generation, manipulation and detection of spin-polarized electrons in low-dimensional semiconductors are at the heart of spintronics. Pure spin currents, that is, fluxes of magnetization without charge current, are quite attractive in this respect. A paradigmatic example is the spin Hall effect, where an electrical current drives a transverse spin current and causes a non-equilibrium spin accumulation observed near the sample boundary. Here we provide evidence for an another effect causing spin currents which is fundamentally different from the spin Hall effect. In contrast to the spin Hall effect, it does not require an electric current to flow: without bias the spin separation is achieved by spin-dependent scattering of electrons in media with suitable symmetry. We show, by free-carrier absorption of terahertz (THz) radiation, that spin currents flow in a wide range of temperatures. Moreover, the experimental results provide evidence that simple electron gas heating by any means is already sufficient to yield spin separation due to spin-dependent energy-relaxation processes.

  8. 41 CFR 101-27.208 - Inventory analyses.

    Science.gov (United States)

    2010-07-01

    ...-Management of Shelf-Life Materials § 101-27.208 Inventory analyses. (a) An inventory analysis shall be... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Inventory analyses. 101-27.208 Section 101-27.208 Public Contracts and Property Management Federal Property Management...

  9. Media bias under direct and indirect government control: when is the bias smaller?

    OpenAIRE

    Abhra Roy

    2015-01-01

    We present an analytical framework to compare media bias under direct and indirect government control. In this context, we show that direct control can lead to a smaller bias and higher welfare than indirect control. We further show that the size of the advertising market affects media bias only under direct control. Media bias, under indirect control, is not affected by the size of the advertising market.

  10. Anchoring and Publicity Effects in Clinical Judgment.

    Science.gov (United States)

    Friedlander, Myrna L.; Stockman, Susan J.

    1983-01-01

    Tested anchoring and publicity effects in clinicians' (N=46) successive judgments of detailed interview notes. Results indicated significant anchoring in one case suggesting a clinical bias. Public justification was related neither to subjects' ratings, to reported confidence in their ratings, nor differentially by case. (JAC)

  11. Understanding Unconscious Bias and Unintentional Racism

    Science.gov (United States)

    Moule, Jean

    2009-01-01

    Unconscious biases affect one's relationships, whether they are fleeting relationships in airports or longer term relationships between teachers and students, teachers and parents, teachers and other educators. In this article, the author argues that understanding one's possible biases is essential for developing community in schools.…

  12. Belief biases and volatility of assets

    Science.gov (United States)

    Lei-Sun, Wen-Zou, Hui

    2014-10-01

    Based on an overlapping generation model, this paper introduces the noise traders with belief biases and rational traders. With an equilibrium analysis, this paper examines the volatility of risky asset. The results show that the belief biases, the probability of economy state, and the domain capability are all the factors that have effects on the volatility of the market.

  13. COVARIATION BIAS AND THE RETURN OF FEAR

    NARCIS (Netherlands)

    de Jong, Peter; VANDENHOUT, MA; MERCKELBACH, H

    1995-01-01

    Several studies have indicated that phobic fear is accompanied by a covariation bias, i.e. that phobic Ss tend to overassociate fear relevant stimuli and aversive outcomes. Such a covariation bias seems to be a fairly direct and powerful way to confirm danger expectations and enhance fear. Therefore

  14. Bounding the bias of contrastive divergence learning

    DEFF Research Database (Denmark)

    Fischer, Anja; Igel, Christian

    2011-01-01

    Optimization based on k-step contrastive divergence (CD) has become a common way to train restricted Boltzmann machines (RBMs). The k-step CD is a biased estimator of the log-likelihood gradient relying on Gibbs sampling. We derive a new upper bound for this bias. Its magnitude depends on k...

  15. Length-biased Weighted Maxwell Distribution

    Directory of Open Access Journals (Sweden)

    Kanak Modi

    2015-12-01

    Full Text Available The concept of length-biased distribution can be employed in development of proper models for life-time data. In this paper, we develop the length-biased form of Weighted Maxwell distribution (WMD. We study the statistical properties of the derived distribution including moments, moment generating function, hazard rate, reverse hazard rate, Shannon entropy and estimation of parameters

  16. Developmental Changes in the Whole Number Bias

    Science.gov (United States)

    Braithwaite, David W.; Siegler, Robert S.

    2017-01-01

    Many students' knowledge of fractions is adversely affected by whole number bias, the tendency to focus on the separate whole number components (numerator and denominator) of a fraction rather than on the fraction's integrated magnitude (ratio of numerator to denominator). Although whole number bias appears early in the fraction learning process…

  17. Reducing status quo bias in choice experiments

    DEFF Research Database (Denmark)

    Bonnichsen, Ole; Ladenburg, Jacob

    In stated preference literature, the tendency to choose the alternative representing the status quo situation seems to exceed real life status quo effects. Accordingly, status quo bias can be a problem. In Choice Experiments, status quo bias is found to be strongly correlated with protest attitudes...

  18. Reducing status quo bias in choice experiments

    DEFF Research Database (Denmark)

    Bonnichsen, Ole; Ladenburg, Jacob

    2015-01-01

    to be superior, i.e. a status quo effect. However, in the stated preference literature, the tendency to choose the alternative representing the status quo situation seems to exceed real life status quo effects. Accordingly, status quo bias can be a problem. In the Choice Experiment literature, status quo bias...

  19. Distinctive Characteristics of Sexual Orientation Bias Crimes

    Science.gov (United States)

    Stacey, Michele

    2011-01-01

    Despite increased attention in the area of hate crime research in the past 20 years, sexual orientation bias crimes have rarely been singled out for study. When these types of crimes are looked at, the studies are typically descriptive in nature. This article seeks to increase our knowledge of sexual orientation bias by answering the question:…

  20. On Measurement Bias in Causal Inference

    CERN Document Server

    Pearl, Judea

    2012-01-01

    This paper addresses the problem of measurement errors in causal inference and highlights several algebraic and graphical methods for eliminating systematic bias induced by such errors. In particulars, the paper discusses the control of partially observable confounders in parametric and non parametric models and the computational problem of obtaining bias-free effect estimates in such models.

  1. Understanding Implicit Bias: What Educators Should Know

    Science.gov (United States)

    Staats, Cheryl

    2016-01-01

    The desire to ensure the best for children is precisely why educators should become aware of the concept of implicit bias: the attitudes or stereotypes that affect our understanding, actions, and decisions in an unconscious manner. Operating outside of our conscious awareness, implicit biases are pervasive, and they can challenge even the most…

  2. Distinctive Characteristics of Sexual Orientation Bias Crimes

    Science.gov (United States)

    Stacey, Michele

    2011-01-01

    Despite increased attention in the area of hate crime research in the past 20 years, sexual orientation bias crimes have rarely been singled out for study. When these types of crimes are looked at, the studies are typically descriptive in nature. This article seeks to increase our knowledge of sexual orientation bias by answering the question:…

  3. Associated Factors and Consequences of Risk of Bias in Randomized Controlled Trials of Yoga: A Systematic Review.

    Directory of Open Access Journals (Sweden)

    Holger Cramer

    Full Text Available Bias in randomized controlled trials (RCTs of complementary therapy interventions seems to be associated with specific factors and to potentially distort the studies' conclusions. This systematic review assessed associated factors of risk of bias and consequences for the studies' conclusions in RCTs of yoga as one of the most commonly used complementary therapies.Medline/PubMed, Scopus, IndMED and the Cochrane Library were searched through February 2014 for yoga RCTs. Risk of selection bias was assessed using the Cochrane tool and regressed to a publication year; b country of origin; c journal type; and d impact factor using multiple logistic regression analysis. Likewise, the authors' conclusions were regressed to risk of bias.A total of 312 RCTs were included. Impact factor ranged from 0.0 to 39.2 (median = 1.3; 60 RCT (19.2% had a low risk of selection bias, and 252 (80.8% had a high or unclear risk of selection bias. Only publication year and impact factor significantly predicted low risk of bias; RCTs published after 2001 (adjusted odds ratio (OR = 12.6; 95% confidence interval (CI = 1.7, 94.0; p<0.001 and those published in journals with impact factor (adjusted OR = 2.6; 95%CI = 1.4, 4.9; p = 0.004 were more likely to have low risk of bias. The authors' conclusions were not associated with risk of bias.Risk of selection bias was generally high in RCTs of yoga; although the situation has improved since the publication of the revised CONSORT statement 2001. Pre-CONSORT RCTs and those published in journals without impact factor should be handled with increased care; although risk of bias is unlikely to distort the RCTs' conclusions.

  4. Reporting Quality of Systematic Reviews/Meta-Analyses of Acupuncture

    Science.gov (United States)

    Liu, Yali; Zhang, Rui; Huang, Jiao; Zhao, Xu; Liu, Danlu; Sun, Wanting; Mai, Yuefen; Zhang, Peng; Wang, Yajun; Cao, Hua; Yang, Ke hu

    2014-01-01

    Background The QUOROM and PRISMA statements were published in 1999 and 2009, respectively, to improve the consistency of reporting systematic reviews (SRs)/meta-analyses (MAs) of clinical trials. However, not all SRs/MAs adhere completely to these important standards. In particular, it is not clear how well SRs/MAs of acupuncture studies adhere to reporting standards and which reporting criteria are generally ignored in these analyses. Objectives To evaluate reporting quality in SRs/MAs of acupuncture studies. Methods We performed a literature search for studies published prior to 2014 using the following public archives: PubMed, EMBASE, Web of Science, the Cochrane Database of Systematic Reviews (CDSR), the Chinese Biomedical Literature Database (CBM), the Traditional Chinese Medicine (TCM) database, the Chinese Journal Full-text Database (CJFD), the Chinese Scientific Journal Full-text Database (CSJD), and the Wanfang database. Data were extracted into pre-prepared Excel data-extraction forms. Reporting quality was assessed based on the PRISMA checklist (27 items). Results Of 476 appropriate SRs/MAs identified in our search, 203, 227, and 46 were published in Chinese journals, international journals, and the Cochrane Database, respectively. In 476 SRs/MAs, only 3 reported the information completely. By contrast, approximately 4.93% (1/203), 8.81% (2/227) and 0.00% (0/46) SRs/Mas reported less than 10 items in Chinese journals, international journals and CDSR, respectively. In general, the least frequently reported items (reported≤50%) in SRs/MAs were “protocol and registration”, “risk of bias across studies”, and “additional analyses” in both methods and results sections. Conclusions SRs/MAs of acupuncture studies have not comprehensively reported information recommended in the PRISMA statement. Our study underscores that, in addition to focusing on careful study design and performance, attention should be paid to comprehensive reporting standards

  5. Market Efficiency and Behavioral Biases in the WNBA Betting Market

    Directory of Open Access Journals (Sweden)

    Rodney J. Paul

    2014-04-01

    Full Text Available The betting market for the Women’s National Basketball Association (WNBA is a thin financial market, which does not attract much interest from sports bettors. Given these characteristics, it is possible that profitable wagering strategies could exist for informed bettors of the WNBA. Using betting data on the WNBA from 2007–2012, we find that simple betting strategies do not earn statistically significant returns. WNBA bettors are like NBA bettors; however, in that they strongly prefer the best teams, particularly when they are on the road. Despite this clear bias, betting against the most popular public wagers is not found to earn statistically significant profits.

  6. Ascertainment bias in studies of human genome-wide polymorphism

    DEFF Research Database (Denmark)

    Clark, Andrew G.; Hubisz, Melissa J.; Bustamente, Carlos D.;

    2005-01-01

    of the SNPs that are found are influenced by the discovery sampling effort. The International HapMap project relied on nearly any piece of information available to identify SNPs-including BAC end sequences, shotgun reads, and differences between public and private sequences-and even made use of chimpanzee...... these studies. However, discrepancies persist, suggesting that the heterogeneity in the SNP discovery process of the HapMap project resulted in a data set resistant to complete ascertainment correction. Ascertainment bias will likely erode the power of tests of association between SNPs and complex disorders...

  7. Outcome Reporting Bias in Government-Sponsored Policy Evaluations: A Qualitative Content Analysis of 13 Studies.

    Science.gov (United States)

    Vaganay, Arnaud

    The reporting of evaluation outcomes can be a point of contention between evaluators and policy-makers when a given reform fails to fulfil its promises. Whereas evaluators are required to report outcomes in full, policy-makers have a vested interest in framing these outcomes in a positive light-especially when they previously expressed a commitment to the reform. The current evidence base is limited to a survey of policy evaluators, a study on reporting bias in education research and several studies investigating the influence of industry sponsorship on the reporting of clinical trials. The objective of this study was twofold. Firstly, it aimed to assess the risk of outcome reporting bias (ORB or 'spin') in pilot evaluation reports, using seven indicators developed by clinicians. Secondly, it sought to examine how the government's commitment to a given reform may affect the level of ORB found in the corresponding evaluation report. To answer these questions, 13 evaluation reports were content-analysed, all of which found a non-significant effect of the intervention on its stated primary outcome. These reports were systematically selected from a dataset of 233 pilot and experimental evaluations spanning three policy areas and 13 years of government-commissioned research in the UK. The results show that the risk of ORB is real. Indeed, all studies reviewed here resorted to at least one of the presentational strategies associated with a risk of spin. This study also found a small, negative association between the seniority of the reform's champion and the risk of ORB in the evaluation of that reform. The publication of protocols and the use of reporting guidelines are recommended.

  8. Implicit Social Biases in People With Autism.

    Science.gov (United States)

    Birmingham, Elina; Stanley, Damian; Nair, Remya; Adolphs, Ralph

    2015-11-01

    Implicit social biases are ubiquitous and are known to influence social behavior. A core diagnostic criterion of autism spectrum disorders (ASD) is abnormal social behavior. We investigated the extent to which individuals with ASD might show a specific attenuation of implicit social biases, using Implicit Association Tests (IATs) involving social (gender, race) and nonsocial (nature, shoes) categories. High-functioning adults with ASD showed intact but reduced IAT effects relative to healthy control participants. We observed no selective attenuation of implicit social (vs. nonsocial) biases in our ASD population. To extend these results, we supplemented our healthy control data with data collected from a large online sample from the general population and explored correlations between autistic traits and IAT effects. We observed no systematic relationship between autistic traits and implicit social biases in our online and control samples. Taken together, these results suggest that implicit social biases, as measured by the IAT, are largely intact in ASD.

  9. Adaptive Variable Bias Magnetic Bearing Control

    Science.gov (United States)

    Johnson, Dexter; Brown, Gerald V.; Inman, Daniel J.

    1998-01-01

    Most magnetic bearing control schemes use a bias current with a superimposed control current to linearize the relationship between the control current and the force it delivers. With the existence of the bias current, even in no load conditions, there is always some power consumption. In aerospace applications, power consumption becomes an important concern. In response to this concern, an alternative magnetic bearing control method, called Adaptive Variable Bias Control (AVBC), has been developed and its performance examined. The AVBC operates primarily as a proportional-derivative controller with a relatively slow, bias current dependent, time-varying gain. The AVBC is shown to reduce electrical power loss, be nominally stable, and provide control performance similar to conventional bias control. Analytical, computer simulation, and experimental results are presented in this paper.

  10. Are all biases missing data problems?

    Science.gov (United States)

    Howe, Chanelle J; Cain, Lauren E; Hogan, Joseph W

    2015-09-01

    Estimating causal effects is a frequent goal of epidemiologic studies. Traditionally, there have been three established systematic threats to consistent estimation of causal effects. These three threats are bias due to confounders, selection, and measurement error. Confounding, selection, and measurement bias have typically been characterized as distinct types of biases. However, each of these biases can also be characterized as missing data problems that can be addressed with missing data solutions. Here we describe how the aforementioned systematic threats arise from missing data as well as review methods and their related assumptions for reducing each bias type. We also link the assumptions made by the reviewed methods to the missing completely at random (MCAR) and missing at random (MAR) assumptions made in the missing data framework that allow for valid inferences to be made based on the observed, incomplete data.

  11. Composite biasing in Monte Carlo radiative transfer

    CERN Document Server

    Baes, Maarten; Lunttila, Tuomas; Bianchi, Simone; Camps, Peter; Juvela, Mika; Kuiper, Rolf

    2016-01-01

    Biasing or importance sampling is a powerful technique in Monte Carlo radiative transfer, and can be applied in different forms to increase the accuracy and efficiency of simulations. One of the drawbacks of the use of biasing is the potential introduction of large weight factors. We discuss a general strategy, composite biasing, to suppress the appearance of large weight factors. We use this composite biasing approach for two different problems faced by current state-of-the-art Monte Carlo radiative transfer codes: the generation of photon packages from multiple components, and the penetration of radiation through high optical depth barriers. In both cases, the implementation of the relevant algorithms is trivial and does not interfere with any other optimisation techniques. Through simple test models, we demonstrate the general applicability, accuracy and efficiency of the composite biasing approach. In particular, for the penetration of high optical depths, the gain in efficiency is spectacular for the spe...

  12. Eulerian bias and the galaxy density field

    CERN Document Server

    Mann, B M; Heavens, A F; Mann, Bob; Peacock, John; Heavens, Alan

    1997-01-01

    We investigate the effects on cosmological clustering statistics of empirical biasing, where the galaxy distribution is a local transformation of the present-day Eulerian density field. The effects of the suppression of galaxy numbers in voids, and their enhancement in regions of high density, are considered, independently and in combination. We compare results from numerical simulations with the predictions of simple analytic models. We find that the bias is generally scale-dependent, so that the shape of the galaxy power spectrum differs from that of the underlying mass distribution. The degree of bias is always a monotonic function of scale, tending to an asymptotic value on scales where the density fluctuations are linear. The scale dependence is often rather weak, with many reasonable prescriptions giving a bias which is nearly independent of scale. We have investigated whether such an Eulerian bias can reconcile a range of theoretical power spectra with the twin requirements of fitting the galaxy power ...

  13. Sampling Bias on Cup Anemometer Mean Winds

    Science.gov (United States)

    Kristensen, L.; Hansen, O. F.; Højstrup, J.

    2003-10-01

    The cup anemometer signal can be sampled in several ways to obtain the mean wind speed. Here we discuss the sampling of series of mean wind speeds from consecutive rotor rotations, followed by unweighted and weighted averaging. It is shown that the unweighted averaging creates a positive bias on the long-term mean wind speed, which is at least one order of magnitude larger than the positive bias from the weighted averaging, also known as the sample-and-hold method. For a homogeneous, neutrally stratified flow the first biases are 1%-2%. For comparison the biases due to fluctuations of the three wind velocity components and due to calibration non-linearity are determined under the same conditions. The largest of these is the v-bias from direction fluctuations. The calculations pertain to the Risø P2546A model cup anemometer.

  14. An assessment of bias and uncertainty in recorded dose from external sources of radiation for workers at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Fix, J.J.; Gilbert, E.S.; Baumgartner, W.V.

    1994-08-01

    Worker dose estimates are used in epidemiologic studies of nuclear workers. A major objective of these studies is to provide a direct assessment of the carcinogenic risk of exposure to ionizing radiation at low doses and dose rates. If dose estimates used in analyses of worker data are biased, then risk estimates expressed per unit of dose will also be biased. In addition, random error in dose estimates may lead to underestimation of risk coefficients and can also distort dose-response analyses. Analyses of data from nuclear worker studies, including Hanford, have typically not been adjusted for biases and uncertainties in dose estimates in part because of the lack of adequate information on the nature and magnitude of these biases and uncertainties. This report describes an approach used to assess bias and uncertainty in radiation dose for Hanford dosimetry systems. The approach can be considered as an elaboration of work conducted by a technical committee appointed by the National Academy of Sciences (NAS) used to quantify the bias and uncertainty in estimated doses for personnel exposed to radiation as a result of atmospheric testing of nuclear weapons between 1945 and 1962. In addition, laboratory studies were conducted to measure bias for selected sources of photon radiation resulting from angular response characteristics of Hanford dosimeter systems. An overall assessment is presented of bias and uncertainty for photon radiation greater than 100 keV. This radiation is expected to have caused the vast majority of recorded dose for Hanford workers.

  15. Laser Beam Focus Analyser

    DEFF Research Database (Denmark)

    Nielsen, Peter Carøe; Hansen, Hans Nørgaard; Olsen, Flemming Ove

    2007-01-01

    The quantitative and qualitative description of laser beam characteristics is important for process implementation and optimisation. In particular, a need for quantitative characterisation of beam diameter was identified when using fibre lasers for micro manufacturing. Here the beam diameter limits...... the obtainable features in direct laser machining as well as heat affected zones in welding processes. This paper describes the development of a measuring unit capable of analysing beam shape and diameter of lasers to be used in manufacturing processes. The analyser is based on the principle of a rotating...... mechanical wire being swept through the laser beam at varying Z-heights. The reflected signal is analysed and the resulting beam profile determined. The development comprised the design of a flexible fixture capable of providing both rotation and Z-axis movement, control software including data capture...

  16. Pharmaceutical Sponsorship Bias Influences Thrombolytic Literature in Acute Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    Ryan P Radecki

    2011-05-01

    Full Text Available Background: The efficacy of thrombolytic therapy for acute ischemic stroke remains controversial in Emergency Medicine and has not been fully endorsed by either the American College of Emergency Physicians or the American Academy of emergency medicine. A growing recognition exists of the influence of pharmaceutical sponsorship on the reported findings of published clinical trials. Sponsorship bias has been suggested as a potential criticism of the literature and guidelines favoring thrombolytic therapy. Objective: The objective of this study is to review the most influential literature regarding thrombolytic therapy for acute ischemic stroke and document the presence or absence of pharmaceutical sponsorship. Methods: A publication-citation analysis was performed to identify the most frequently cited articles pertaining to thrombolytic therapy for acute ischemic stroke. Identified articles were reviewed for disclosures of pharmaceutical funding. Results: Of the 20 most-cited articles pertaining to thrombolytic therapy for acute stroke, 17 (85% disclosed pharmaceutical sponsorship. These disclosures range from general sponsorship to direct employment of authors by pharmaceutical companies. Conclusion: An overwhelming predominance of the most influential literature regarding thrombolytic therapy for acute ischemic stroke is susceptible to sponsorship bias. This potential bias may provide a basis for physician concern regarding the efficacy and safety of thrombolytic therapy. Further, large, independent, placebo-controlled studies may be required to guide therapy and professional guidelines definitively for acute ischemic stroke. [West J Emerg Med. 2011;12(4:435–441.

  17. WeBIAS: a web server for publishing bioinformatics applications.

    Science.gov (United States)

    Daniluk, Paweł; Wilczyński, Bartek; Lesyng, Bogdan

    2015-11-02

    One of the requirements for a successful scientific tool is its availability. Developing a functional web service, however, is usually considered a mundane and ungratifying task, and quite often neglected. When publishing bioinformatic applications, such attitude puts additional burden on the reviewers who have to cope with poorly designed interfaces in order to assess quality of presented methods, as well as impairs actual usefulness to the scientific community at large. In this note we present WeBIAS-a simple, self-contained solution to make command-line programs accessible through web forms. It comprises a web portal capable of serving several applications and backend schedulers which carry out computations. The server handles user registration and authentication, stores queries and results, and provides a convenient administrator interface. WeBIAS is implemented in Python and available under GNU Affero General Public License. It has been developed and tested on GNU/Linux compatible platforms covering a vast majority of operational WWW servers. Since it is written in pure Python, it should be easy to deploy also on all other platforms supporting Python (e.g. Windows, Mac OS X). Documentation and source code, as well as a demonstration site are available at http://bioinfo.imdik.pan.pl/webias . WeBIAS has been designed specifically with ease of installation and deployment of services in mind. Setting up a simple application requires minimal effort, yet it is possible to create visually appealing, feature-rich interfaces for query submission and presentation of results.

  18. Public lighting.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1986-01-01

    The function of public lighting and the relationship between public lighting and accidents are considered briefly as aspects of effective countermeasures. Research needs and recent developments in installation and operational described. Public lighting is an efficient accident countermeasure, but

  19. Google and the digital divide the bias of online knowledge

    CERN Document Server

    Segev, Elad

    2010-01-01

    Beneficial to scholars and students in the fields of media and communication, politics and technology, this book outlines the significant role of search engines in general and Google in particular in widening the digital divide between individuals, organisations and states. It uses innovative methods and research approaches to assess and illustrate the digital divide by comparing the popular search queries in Google and Yahoo in different countries as well as analysing the various biases in Google News and Google Earth. The different studies developed and presented in this book provide various

  20. Publication point indicators

    DEFF Research Database (Denmark)

    Elleby, Anita; Ingwersen, Peter

    2010-01-01

    with novel publication point indicators (PPIs) that are formalized and exemplified. Two diachronic citation windows are applied: 2006-07 and 2006-08. Web of Science (WoS) as well as Google Scholar (GS) are applied to observe the cite delay and citedness for the different document types published by DIIS......The paper presents comparative analyses of two publication point systems, The Norwegian and the in-house system from the interdiscplinary Danish Institute for International Studies (DIIS), used as case in the study for publications published 2006, and compares central citation-based indicators......; the Cumulated Publication Point Indicator (CPPI), which graphically illustrates the cumulated gain of obtained vs. ideal points, both seen as vectors; and the normalized Cumulated Publication Point Index (nCPPI) that represents the cumulated gain of publication success as index values, either graphically...

  1. Assessing threat responses towards the symptoms and diagnosis of schizophrenia using visual perceptual biases.

    Science.gov (United States)

    Heenan, Adam; Best, Michael W; Ouellette, Sarah J; Meiklejohn, Erin; Troje, Nikolaus F; Bowie, Christopher R

    2014-10-01

    Stigma towards individuals diagnosed with schizophrenia continues despite increasing public knowledge about the disorder. Questionnaires are used almost exclusively to assess stigma despite self-report biases affecting their validity. The purpose of this experiment was to implicitly assess stigma towards individuals with schizophrenia by measuring visual perceptual biases immediately after participants conversed with a confederate. We manipulated both the diagnostic label attributed to the confederate (peer vs. schizophrenia) and the presence of behavioural symptoms (present vs. absent). Immediately before and after conversing with the confederate, we measured participants' facing-the-viewer (FTV) biases (the preference to perceive depth-ambiguous stick-figure walkers as facing towards them). As studies have suggested that the FTV bias is sensitive to the perception of threat, we hypothesized that FTV biases would be greater after participants conversed with someone that they believed had schizophrenia, and also after they conversed with someone who presented symptoms of schizophrenia. We found partial support for these hypotheses. Participants had significantly greater FTV biases in the Peer Label/Symptoms Present condition. Interestingly, while FTV biases were lowest in the Schizophrenia Label/Symptoms Present condition, participants in this condition were most likely to believe that people with schizophrenia should face social restrictions. Our findings support that both implicit and explicit beliefs help develop and sustain stigma.

  2. Investigating the role of social-affective attachment processes in cradling bias: the absence of cradling bias in children with Autism Spectrum Disorders.

    Science.gov (United States)

    Pileggi, Lea-Ann; Malcolm-Smith, Susan; Solms, Mark

    2015-01-01

    Previous studies suggest that leftward cradling bias may facilitate mother-infant relationships, as it preferentially locates the infant in the mother's left hemi-space, which is specialized for several social-affective processes. If leftward cradling bias is mediated by social-affective attachment processes, it should be reduced in humans who are deficient in such processes. Individuals diagnosed with Autism Spectrum Disorders (ASDs) constitute a population with known deficits in social and emotional relating. A pilot study confirmed reduced bias in this group, and in the present study, we elaborated methods to assess also the impact of higher cognitive processes on cradling bias. Direct systematic observation was used to investigate the occurrence of cradling bias in ASD, non-ASD intellectually disabled children and typically developing children. Ninety-three participants aged 5-15 years cradled a life-like doll on four separate occasions. Intelligence and executive functions were assessed. Regression analyses revealed that ASD diagnosis was the only significant predictor of atypical cradling preference. While intellectually disabled and typically developing children clearly preferred to cradle to the left, no preference was evident in the ASD group. Results support the hypothesis that leftward cradling bias is associated with basic social-affective capacities.

  3. Analysis of the Bias on the Beidou GEO Multipath Combinations

    Directory of Open Access Journals (Sweden)

    Yafei Ning

    2016-08-01

    Full Text Available The Beidou navigation satellite system is a very important sensor for positioning in the Asia-Pacific region. The Beidou inclined geosynchronous orbit (IGSO and medium Earth orbit (MEO satellites have been analysed in some studies previously conducted by other researchers; this paper seeks to gain more insight regarding the geostationary earth orbit (GEO satellites. Employing correlation analysis, Fourier transformation and wavelet decomposition, we validate whether there is a systematic bias in their multipath combinations. These biases can be observed clearly in satellites C01, C02 and C04 and have a great correlation with time series instead of elevation, being significantly different from those of the Beidou IGSO and MEO satellites. We propose a correction model to mitigate this bias based on its daily periodicity characteristic. After the model has been applied, the performance of the positioning estimations of the eight stations distributed in the Asia-Pacific region is evaluated and compared. The results show that residuals of multipath series behaves random noise; for the single point positioning (SPP and precise point positioning (PPP approaches, the positioning accuracy in the upward direction can be improved by 8 cm and 6 mm, respectively, and by 2 cm and 4 mm, respectively, for the horizontal component.

  4. Alleviating bias leads to accurate and personalized recommendation

    Science.gov (United States)

    Qiu, Tian; Wang, Tian-Tian; Zhang, Zi-Ke; Zhong, Li-Xin; Chen, Guang

    2013-11-01

    Recommendation bias towards objects has been found to have an impact on personalized recommendation, since objects present heterogeneous characteristics in some network-based recommender systems. In this article, based on a biased heat conduction recommendation algorithm (BHC) which considers the heterogeneity of the target objects, we propose a heterogeneous heat conduction algorithm (HHC), by further taking the heterogeneity of the source objects into account. Tested on three real datasets, the Netflix, RYM and MovieLens, the HHC algorithm is found to present better recommendation in both the accuracy and diversity than two benchmark algorithms, i.e., the original BHC and a hybrid algorithm of heat conduction and mass diffusion (HHM), while not requiring any other accessorial information or parameter. Moreover, the HHC algorithm also elevates the recommendation accuracy on cold objects, referring to the so-called cold-start problem. Eigenvalue analyses show that, the HHC algorithm effectively alleviates the recommendation bias towards objects with different level of popularity, which is beneficial to solving the accuracy-diversity dilemma.

  5. Going round the bend: Persistent personal biases in walked angles.

    Science.gov (United States)

    Jetzschke, Simon; Ernst, Marc O; Moscatelli, Alessandro; Boeddeker, Norbert

    2016-03-23

    For navigation through our environment, we can rely on information from various modalities, such as vision and audition. This information enables us for example to estimate our position relative to the starting position, or to integrate velocity and acceleration signals from the vestibular organ and proprioception to estimate the displacement due to self-motion. To better understand the mechanisms that underlie human navigation we analysed the performance of participants in an angle-walking task in the absence of visual and auditory signals. To this end, we guided them along paths of different lengths and asked them to turn by an angle of ±90°. We found significant biases in turn angles, i.e. systematic deviations from the correct angle and that these were characteristic for individual participants. Varying path length, however, had little effect on turn accuracy and precision. To check whether this idiosyncrasy was persistent over time and present in another type of walking task, we performed a second experiment several weeks later. Here, the same participants were guided to walk angles with varying amplitude. We then asked them to judge whether they had walked an angle larger or smaller than 90° in a two-alternative forced-choice paradigm. The personal bias was highly correlated between the two experiments even though they were conducted weeks apart. The presence of a persistent bias in walked angles in the absence of external directional cues indicates a possible error component for navigation, which is surprisingly time stable and idiosyncratic.

  6. Analysis of the Bias on the Beidou GEO Multipath Combinations

    Science.gov (United States)

    Ning, Yafei; Yuan, Yunbin; Chai, Yanju; Huang, Yong

    2016-01-01

    The Beidou navigation satellite system is a very important sensor for positioning in the Asia-Pacific region. The Beidou inclined geosynchronous orbit (IGSO) and medium Earth orbit (MEO) satellites have been analysed in some studies previously conducted by other researchers; this paper seeks to gain more insight regarding the geostationary earth orbit (GEO) satellites. Employing correlation analysis, Fourier transformation and wavelet decomposition, we validate whether there is a systematic bias in their multipath combinations. These biases can be observed clearly in satellites C01, C02 and C04 and have a great correlation with time series instead of elevation, being significantly different from those of the Beidou IGSO and MEO satellites. We propose a correction model to mitigate this bias based on its daily periodicity characteristic. After the model has been applied, the performance of the positioning estimations of the eight stations distributed in the Asia-Pacific region is evaluated and compared. The results show that residuals of multipath series behaves random noise; for the single point positioning (SPP) and precise point positioning (PPP) approaches, the positioning accuracy in the upward direction can be improved by 8 cm and 6 mm, respectively, and by 2 cm and 4 mm, respectively, for the horizontal component. PMID:27509503

  7. A Diffusion Model Analysis of Decision Biases Affecting Delayed Recognition of Emotional Stimuli.

    Science.gov (United States)

    Bowen, Holly J; Spaniol, Julia; Patel, Ronak; Voss, Andreas

    2016-01-01

    Previous empirical work suggests that emotion can influence accuracy and cognitive biases underlying recognition memory, depending on the experimental conditions. The current study examines the effects of arousal and valence on delayed recognition memory using the diffusion model, which allows the separation of two decision biases thought to underlie memory: response bias and memory bias. Memory bias has not been given much attention in the literature but can provide insight into the retrieval dynamics of emotion modulated memory. Participants viewed emotional pictorial stimuli; half were given a recognition test 1-day later and the other half 7-days later. Analyses revealed that emotional valence generally evokes liberal responding, whereas high arousal evokes liberal responding only at a short retention interval. The memory bias analyses indicated that participants experienced greater familiarity with high-arousal compared to low-arousal items and this pattern became more pronounced as study-test lag increased; positive items evoke greater familiarity compared to negative and this pattern remained stable across retention interval. The findings provide insight into the separate contributions of valence and arousal to the cognitive mechanisms underlying delayed emotion modulated memory.

  8. Composition in portraits: Selfies and wefies reveal similar biases in untrained modern youths and ancient masters.

    Science.gov (United States)

    Bruno, Nicola; Bode, Carole; Bertamini, Marco

    2017-05-01

    Previous analyses suggest that artists prefer poses showing the left side of the subject's face when composing a portrait, but showing the right side when composing their own self-portrait. There is also some evidence that artists may prefer compositions with key features on the right of the picture. Do these findings generalize to spontaneous, pseudo-artistic productions by individuals with no formal training in painting and art history? To investigate this issue, we tested a sample of 104 British schoolchildren and teenagers (mean age = 13.8 years; 80 females). We analysed posing biases in individual photographic self-portraits ("selfies") as well as of self-portraits including also the portrait of a friend ("wefies"). Our results document a bias for showing the left cheek in selfies, a bias for placing the selfie-taker on the right in wefies, and a bias for showing two left cheeks over two right cheeks, again in wefies. These biases are reminiscent of what has been reported for selfies in adult non-artists and for portraits and self-portraits by artists in the 16th-18th centuries. Thus, these results provide new evidence in support of a biological basis for side biases in portraits and self-portraits independently of training and expertise.

  9. Meta-analyses

    NARCIS (Netherlands)

    Hendriks, M.A.; Luyten, J.W.; Scheerens, J.; Sleegers, P.J.C.; Scheerens, J.

    2014-01-01

    In this chapter results of a research synthesis and quantitative meta-analyses of three facets of time effects in education are presented, namely time at school during regular lesson hours, homework, and extended learning time. The number of studies for these three facets of time that could be used

  10. Contesting Citizenship: Comparative Analyses

    DEFF Research Database (Denmark)

    Siim, Birte; Squires, Judith

    2007-01-01

    . Comparative citizenship analyses need to be considered in relation to multipleinequalities and their intersections and to multiple governance and trans-national organisinf. This, in turn, suggests that comparative citizenship analysis needs to consider new spaces in which struggles for equal citizenship occur...

  11. Wavelet Analyses and Applications

    Science.gov (United States)

    Bordeianu, Cristian C.; Landau, Rubin H.; Paez, Manuel J.

    2009-01-01

    It is shown how a modern extension of Fourier analysis known as wavelet analysis is applied to signals containing multiscale information. First, a continuous wavelet transform is used to analyse the spectrum of a nonstationary signal (one whose form changes in time). The spectral analysis of such a signal gives the strength of the signal in each…

  12. Report sensory analyses veal

    NARCIS (Netherlands)

    Veldman, M.; Schelvis-Smit, A.A.M.

    2005-01-01

    On behalf of a client of Animal Sciences Group, different varieties of veal were analyzed by both instrumental and sensory analyses. The sensory evaluation was performed with a sensory analytical panel in the period of 13th of May and 31st of May, 2005. The three varieties of veal were: young bull,

  13. On the power of the test for cluster bias

    NARCIS (Netherlands)

    Jak, S.; Oort, F.J.

    2015-01-01

    Cluster bias refers to measurement bias with respect to the clustering variable in multilevel data. The absence of cluster bias implies absence of bias with respect to any cluster-level (level 2) variable. The variables that possibly cause the bias do not have to be measured to test for cluster

  14. Exchange bias effect in alloys and compounds.

    Science.gov (United States)

    Giri, S; Patra, M; Majumdar, S

    2011-02-23

    The phenomenology of exchange bias effects observed in structurally single-phase alloys and compounds but composed of a variety of coexisting magnetic phases such as ferromagnetic, antiferromagnetic, ferrimagnetic, spin-glass, cluster-glass and disordered magnetic states are reviewed. The investigations on exchange bias effects are discussed in diverse types of alloys and compounds where qualitative and quantitative aspects of magnetism are focused based on macroscopic experimental tools such as magnetization and magnetoresistance measurements. Here, we focus on improvement of fundamental issues of the exchange bias effects rather than on their technological importance.

  15. Reducing status quo bias in choice experiments

    DEFF Research Database (Denmark)

    Bonnichsen, Ole; Ladenburg, Jacob

    In stated preference literature, the tendency to choose the alternative representing the status quo situation seems to exceed real life status quo effects. Accordingly, status quo bias can be a problem. In Choice Experiments, status quo bias is found to be strongly correlated with protest attitudes...... toward the cost attribute. If economic values are to be elicited, this problem is difficult to remedy. In a split sample framework we test a novel ex-ante entreaty aimed specifically at the cost attribute and find that it effectively reduces status quo bias and improves the internal validity...

  16. Quantum Statistical Calculation of Exchange Bias

    Institute of Scientific and Technical Information of China (English)

    WANG Huai-Yu; DAI Zhen-Hong

    2004-01-01

    The phenomenon of exchange bias of ferromagnetic (FM) films, which are coupled with an antiferromagnetic (AFM) film, is studied by Heisenberg model by use of the many-body Green's function method of quantum statistical theory for the uncompensated case. Exchange bias HE and coercivity Hc are calculated as functions of the FM film thickness L, temperature, the strength of the exchange interaction across the interface between FM and AFM and the anisotropy of the FM. Hc decreases with increasing L when the FM film is beyond some thickness. The dependence of the exchange bias HE on the FM film thickness and on temperature is also qualitatively in agreement with experiments.

  17. Removing Malmquist bias from linear regressions

    Science.gov (United States)

    Verter, Frances

    1993-01-01

    Malmquist bias is present in all astronomical surveys where sources are observed above an apparent brightness threshold. Those sources which can be detected at progressively larger distances are progressively more limited to the intrinsically luminous portion of the true distribution. This bias does not distort any of the measurements, but distorts the sample composition. We have developed the first treatment to correct for Malmquist bias in linear regressions of astronomical data. A demonstration of the corrected linear regression that is computed in four steps is presented.

  18. Forecast Bias Correction: A Second Order Method

    CERN Document Server

    Crowell, Sean

    2010-01-01

    The difference between a model forecast and actual observations is called forecast bias. This bias is due to either incomplete model assumptions and/or poorly known parameter values and initial/boundary conditions. In this paper we discuss a method for estimating corrections to parameters and initial conditions that would account for the forecast bias. A set of simple experiments with the logistic ordinary differential equation is performed using an iterative version of a first order version of our method to compare with the second order version of the method.

  19. Eye-Tracking Evidence of a Maintenance Bias in Social Anxiety.

    Science.gov (United States)

    Fernandes, Catarina; Silva, Susana; Pires, Joana; Reis, Alexandra; Ros, Antónia Jimenez; Janeiro, Luís; Faísca, Luís; Martins, Ana Teresa

    2017-06-22

    The mechanisms and triggers of the attentional bias in social anxiety are not yet fully determined, and the modulating role of personality traits is being increasingly acknowledged. Our main purpose was to test whether social anxiety is associated with mechanisms of hypervigilance, avoidance (static biases), vigilance-avoidance or the maintenance of attention (dynamic biases). Our secondary goal was to explore the role of personality structure in shaping the attention bias. Participants with high vs low social anxiety and different personality structures viewed pairs of faces (free-viewing eye-tracking task) representing different emotions (anger, happiness and neutrality). Their eye movements were registered and analysed for both whole-trial (static) and time-dependent (dynamic) measures. Comparisons between participants with high and low social anxiety levels did not yield evidence of differences in eye-tracking measures for the whole trial (latency of first fixation, first fixation direction, total dwell time), but the two groups differed in the time course of overt attention during the trial (dwell time across three successive time segments): participants with high social anxiety were slower in disengaging their attention from happy faces. Similar results were obtained using a full-sample, regression-based analysis. Our results speak in favour of a maintenance bias in social anxiety. Preliminary results indicated that personality structure may not affect the maintenance (dynamic) bias of socially anxious individuals, although depressive personality structures may favour manifestations of a (static) hypervigilance bias.

  20. A study on investors’ personality characteristics and behavioral biases: Conservatism bias and availability bias in the Tehran Stock Exchange

    Directory of Open Access Journals (Sweden)

    Mahmoud Moradi

    2013-04-01

    Full Text Available Most economic and finance theories are based on the assumption that during economic decision making, people would act totally rational and consider all available information. Nevertheless, behavioral finance focuses on studying of the role of psychological factors on economic participants’ behavior. The study shows that in real-world environment, people are influenced by emotional and cognitive errors and may make irrational financial decisions. In many cases, the participants of financial markets are not aware of their talents for error in decision making, so they are dissatisfied with their investments by considering some behavioral biases decisions. These decisions may often yield undesirable outcomes, which could influence economy, significantly. This paper presents a survey on the relationship between personality dimensions with behavioral biases and availability bias among investment managers in the Tehran Stock Exchange using SPSS software, descriptive and inferential statistics. The necessary data are collected through questionnaire and they are analyzed using some statistical tests. The preliminary results indicate that there is a relationship between personality dimensions and behavioral biases like conservatism bias and availability bias among the investors in the Tehran Stock Exchange.