19 research outputs found

    Confounder summary scores when comparing the effects of multiple drug exposures

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    Little information is available comparing methods to adjust for confounding when considering multiple drug exposures. We compared three analytic strategies to control for confounding based on measured variables: conventional multivariable, exposure propensity score (EPS) and disease risk score (DRS)

    Sequential modulations of the Simon effect depend on episodic retrieval

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    Sequential modulations of conflict effects, like the reduction of the Simon effect after incompatible trials, have been taken to reflect the operation of a proactive control mechanism commonly called conflict monitoring. However, such modulations are often contaminated by episodic effects like priming and stimulus-response feature integration. It has previously been observed that if the episodic representation of a conflicting trial is altered by rotating the stimulus framing 180° around its axis, the subsequent “conflict adaptation” pattern is eliminated. In Experiment 1, we replicate the findings and provide the basic episodic interpretation. In Experiment 2, we extend the framework to include rotations of 90°, and verify that the episodic effects generalize to scenarios of neutral compatibility. Finally, in Experiment 3, we add complete, 360° rotations, and show that the episodic manipulation by itself does not eliminate the conflict adaptation patterns – as long as conditions favor episodic retrieval. The experiments are argued to demonstrate that an episodic account of the conflict adaptation effect can most parsimoniously account for the behavioral effects without relying on higher order cognition. Accordingly, we conclude that conflict adaptation can be understood either as critically depending on episodic retrieval, or alternatively reflecting only episodic retrieval itself

    Testâretest reliability of the N400 component in a sentence-reading paradigm

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    © 2017 Informa UK Limited, trading as Taylor & Francis Group The N400 component of the event-related potential is considered an index of semantic processing and therefore may be an ideal biomarker of semantic system disorders or individual differences. To this purpose, it is necessary to assess its testâretest reliability. Only one previous study has addressed this question, reporting good testâretest reliability (râ=â0.85). However, that study had used a word-pair priming paradigm, which differs in many respects from the more typical and ecologically valid sentence-reading. The present study surveys testâretest reliability of the N400 in a sentence-reading paradigm. The best value obtained was râ=â0.63, implying a relatively poor testâretest reliability. Crucial factors for this result may be the long interval between context and critical word as well as more complex contexts in sentence-reading paradigms. These factors might make the N400 effects in sentences more vulnerable to linguistic and non-linguistic factors increasing the variance across sessions.Link_to_subscribed_fulltex

    Performance of the VERSANT (R) HIV-1 Resistance Assays (LiPA) for detecting drug resistance in therapy-naive patients infected with different HIV-1 subtypes

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    In this study we evaluated the performance of the VERSANT((R)) HIV-1 Resistance Assays (LiPA) in detecting drug resistance in therapy-naive HIV-infected patients diagnosed in Belgium in 2000. We compared the results with population sequencing and found concordance to be in line with previous studies in treatment-experienced patients (86.87% for reverse transcriptase (RT); 92.77% for protease (PRO)). Discordance was mainly due to indeterminate reactions on LiPA (8.45% for RT; 6.85% for PRO) and minor discordances (4.13% for RT; 0.25% for PRO). Major discordances were rare (0.46% for RT; 0.12% for PRO). Indeterminate reactions were significantly associated with strains belonging to non-B subtypes. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier B.V.. All rights reserved
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