2,840 research outputs found

    Eliminating grammatical function assignment from hierarchical models of speech production: Evidence from the conceptual accessibility of referents

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    ABSTRACTThe assignment of grammatical functions has been a key feature of hierarchical (serial) models of speech production since their inception in the 1970s. This article argues that grammatical function assignment is neither sufficient nor necessary in such models. It reports a study of the effects of the conceptual accessibility of referents on the selection of English dative syntactic frames in production and shows that the effects relate to linear precedence rather than grammatical function assignment. A secondary topic addressed in the same study is whether second language speakers of English have difficulty integrating syntactic knowledge where it interfaces with conceptual accessibility in speech production. Findings suggest that advanced proficiency speakers do not and are qualitatively similar to native speakers. The implications of this for the interface hypothesis about second language acquisition are discussed.</jats:p

    Artificial intelligence in lung cancer diagnostic imaging: a review of the reporting and conduct of research published 2018–2019

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    Objective: This study aimed to describe the methodologies used to develop and evaluate models that use artificial intelligence (AI) to analyse lung images in order to detect, segment (outline borders of), or classify pulmonary nodules as benign or malignant. Methods: In October 2019, we systematically searched the literature for original studies published between 2018 and 2019 that described prediction models using AI to evaluate human pulmonary nodules on diagnostic chest images. Two evaluators independently extracted information from studies, such as study aims, sample size, AI type, patient characteristics, and performance. We summarised data descriptively. Results: The review included 153 studies: 136 (89%) development-only studies, 12 (8%) development and validation, and 5 (3%) validation-only. CT scans were the most common type of image type used (83%), often acquired from public databases (58%). Eight studies (5%) compared model outputs with biopsy results. 41 studies (26.8%) reported patient characteristics. The models were based on different units of analysis, such as patients, images, nodules, or image slices or patches. Conclusion: The methods used to develop and evaluate prediction models using AI to detect, segment, or classify pulmonary nodules in medical imaging vary, are poorly reported, and therefore difficult to evaluate. Transparent and complete reporting of methods, results and code would fill the gaps in information we observed in the study publications. Advances in knowledge: We reviewed the methodology of AI models detecting nodules on lung images and found that the models were poorly reported and had no description of patient characteristics, with just a few comparing models’ outputs with biopsies results. When lung biopsy is not available, lung-RADS could help standardise the comparisons between the human radiologist and the machine. The field of radiology should not give up principles from the diagnostic accuracy studies, such as the choice for the correct ground truth, just because AI is used. Clear and complete reporting of the reference standard used would help radiologists trust in the performance that AI models claim to have. This review presents clear recommendations about the essential methodological aspects of diagnostic models that should be incorporated in studies using AI to help detect or segmentate lung nodules. The manuscript also reinforces the need for more complete and transparent reporting, which can be helped using the recommended reporting guidelines

    Poor handling of continuous predictors in clinical prediction models using logistic regression: a systematic review

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    Background and Objectives When developing a clinical prediction model, assuming a linear relationship between the continuous predictors and outcome is not recommended. Incorrect specification of the functional form of continuous predictors could reduce predictive accuracy. We examine how continuous predictors are handled in studies developing a clinical prediction model. Methods We searched PubMed for clinical prediction model studies developing a logistic regression model for a binary outcome, published between July 01, 2020, and July 30, 2020. Results In total, 118 studies were included in the review (18 studies (15%) assessed the linearity assumption or used methods to handle nonlinearity, and 100 studies (85%) did not). Transformation and splines were commonly used to handle nonlinearity, used in 7 (n = 7/18, 39%) and 6 (n = 6/18, 33%) studies, respectively. Categorization was most often used method to handle continuous predictors (n = 67/118, 56.8%) where most studies used dichotomization (n = 40/67, 60%). Only ten models included nonlinear terms in the final model (n = 10/18, 56%). Conclusion Though widely recommended not to categorize continuous predictors or assume a linear relationship between outcome and continuous predictors, most studies categorize continuous predictors, few studies assess the linearity assumption, and even fewer use methodology to account for nonlinearity. Methodological guidance is provided to guide researchers on how to handle continuous predictors when developing a clinical prediction model

    Poor handling of continuous predictors in clinical prediction models using logistic regression:a systematic review

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    Background and Objectives When developing a clinical prediction model, assuming a linear relationship between the continuous predictors and outcome is not recommended. Incorrect specification of the functional form of continuous predictors could reduce predictive accuracy. We examine how continuous predictors are handled in studies developing a clinical prediction model. Methods We searched PubMed for clinical prediction model studies developing a logistic regression model for a binary outcome, published between July 01, 2020, and July 30, 2020. Results In total, 118 studies were included in the review (18 studies (15%) assessed the linearity assumption or used methods to handle nonlinearity, and 100 studies (85%) did not). Transformation and splines were commonly used to handle nonlinearity, used in 7 (n = 7/18, 39%) and 6 (n = 6/18, 33%) studies, respectively. Categorization was most often used method to handle continuous predictors (n = 67/118, 56.8%) where most studies used dichotomization (n = 40/67, 60%). Only ten models included nonlinear terms in the final model (n = 10/18, 56%). Conclusion Though widely recommended not to categorize continuous predictors or assume a linear relationship between outcome and continuous predictors, most studies categorize continuous predictors, few studies assess the linearity assumption, and even fewer use methodology to account for nonlinearity. Methodological guidance is provided to guide researchers on how to handle continuous predictors when developing a clinical prediction model

    Sample size requirements are not being considered in studies developing prediction models for binary outcomes: a systematic review

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    Background Having an appropriate sample size is important when developing a clinical prediction model. We aimed to review how sample size is considered in studies developing a prediction model for a binary outcome. Methods We searched PubMed for studies published between 01/07/2020 and 30/07/2020 and reviewed the sample size calculations used to develop the prediction models. Using the available information, we calculated the minimum sample size that would be needed to estimate overall risk and minimise overfitting in each study and summarised the difference between the calculated and used sample size. Results A total of 119 studies were included, of which nine studies provided sample size justification (8%). The recommended minimum sample size could be calculated for 94 studies: 73% (95% CI: 63–82%) used sample sizes lower than required to estimate overall risk and minimise overfitting including 26% studies that used sample sizes lower than required to estimate overall risk only. A similar number of studies did not meet the ≥ 10EPV criteria (75%, 95% CI: 66–84%). The median deficit of the number of events used to develop a model was 75 [IQR: 234 lower to 7 higher]) which reduced to 63 if the total available data (before any data splitting) was used [IQR:225 lower to 7 higher]. Studies that met the minimum required sample size had a median c-statistic of 0.84 (IQR:0.80 to 0.9) and studies where the minimum sample size was not met had a median c-statistic of 0.83 (IQR: 0.75 to 0.9). Studies that met the ≥ 10 EPP criteria had a median c-statistic of 0.80 (IQR: 0.73 to 0.84). Conclusions Prediction models are often developed with no sample size calculation, as a consequence many are too small to precisely estimate the overall risk. We encourage researchers to justify, perform and report sample size calculations when developing a prediction model

    Globalization, the ambivalence of European integration and the possibilities for a post-disciplinary EU studies

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    Using the work of Manuel Castells as a starting point, this article explores the ambivalent relationship between globalization and European integration and the variety of ways in which the mainstream political science of the EU has attempted to deal with this issue. The analysis here suggests that various 'mainstreaming' disciplinary norms induce types of work that fail to address fully the somewhat paradoxical and counter-intuitive range of possible relationships between globalization and European integration. The article explores critically four possible analytical ways out of this paradox—abandonment of the concept of globalization, the development of definition precision in globalization studies, the reorientation of work to focus on globalization as discourse, and inter- and post-disciplinarity. The argument suggests that orthodox discussions of the relationship require a notion of social geography that sits at odds with much of the literature on globalization and while greater dialogue between disciplines is to be welcomed, a series of profound epistemological questions need to be confronted if studies of the interplay between global and social process are to be liberated from their disciplinary chains

    Household economic hardship as a moderator of the associations between maternal spanking and child externalizing behavior problems.

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    Background: Spanking is associated with detrimental outcomes for young children. Research shows that spanking is more commonly used in low-income households. Objective: To examine whether economic hardship, measured by household income-to-poverty ratio at the time of the child’s birth, moderated the longitudinal associations between maternal spanking and child externalizing behavior problems during the first nine years of childhood. Participants and setting: Mother-child pairs (N = 4,149) from a cohort study of urban families in 20 US cities. Methods: Cross-lagged path models examined associations between maternal spanking and ex- ternalizing behavior when children were between the ages of 1 and 9. Multigroup analyses ex- amined whether income-to-poverty ratio moderated these associations. Results: Bivariate analyses showed that income-to-poverty ratio was associated with child ex- ternalizing behavior problems at each time point; income-to-poverty ratio was associated with maternal spanking at age 3 only. Longitudinal path model results indicated that, for low- and middle-income groups, maternal spanking at each age had significant associations with child externalizing behavior at each subsequent age. For the high-income group, maternal spanking at age 1 and age 3 had significant associations with child externalizing behavior at each subsequent age; however, spanking at age 5 was not associated with child externalizing behavior at age 9. Conclusions: Spanking is disadvantageous for children at all income levels, with more persistent effects in low- and middle-income families. For higher-income families, the associations of ma- ternal spanking with child externalizing behavior problems may be attenuated as child age in- creases. Regardless of income level, parents should be advised against spanking.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163755/1/2020-Lee-Householdeconomichardship.pdfDescription of 2020-Lee-Householdeconomichardship.pdf : Main articl

    Attachment style and the association of spanking and child externalizing behavior

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    OBJECTIVE: To examine whether the longitudinal associations between maternal spanking and child externalizing behavior are moderated by attachment style. METHODS: This study used data from the Fragile Families and Child Wellbeing Study (n = 2211), a large cohort sample of low-income urban families. Multiple-group autoregressive cross-lagged models examined the associations between maternal spanking and child externalizing behavior when children were ages 1, 3, and 5. Moderation by attachment style was examined using structural invariance testing. RESULTS: For children with an insecure mother-child attach- ment style, spanking at age 1 was associated with externalizing behavior at age 3. However, for children with a secure mother- child attachment style, the association between maternal spank- ing at age 1 and child externalizing behavior at age 3 was absent. Attachment style did not moderate the association between maternal spanking at age 3 and externalizing behavior at age 5, suggesting that spanking at age 3 is associated with deleterious outcomes at age 5, regardless of attachment style. CONCLUSIONS: Results suggest that even in the context of a secure attachment style, spanking is associated with adverse outcomes in early childhood. Findings support the American Academy of Pediatrics 2018 policy statement, which encour- ages parents to avoid spanking when disciplining children. Results suggest that children, regardless of attachment style, may benefit from policies and services that promote non-vio- lent forms of discipline.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163754/1/2020-Ward-Attachmentstyleandtheassociation.pdfDescription of 2020-Ward-Attachmentstyleandtheassociation.pdf : Main articl
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