27 research outputs found

    Commensurate and modulated magnetic phases in orthorhombic A1C60

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    Competing magnetically ordered structures in polymerized orthorhombic A1C60 are studied. A mean-field theory for the equilibrium phases is developed using an Ising model and a classical Heisenberg model to describe the competition between inter- and intra-chain magnetic order in the solid. In the Ising model, the limiting commensurate one-dimensional and three-dimensional phases are separated by a commensurate three-sublattice state and by two sectors containing higher-order commensurate phases. For the Heisenberg model the quasi-1D phase is never the equilibrium state; instead the 3D commensurate phases exhibits a transition to a continuum of coplanar spiral magnetic phases.Comment: 11 pages REVTeX 3.0 plus 4 figures appende

    Eurosibs: towards robust measurement of infant neurocognitive predictors of Autism across Europe

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    Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that affects social communication skills and flexible behaviour. Developing new treatment approaches for ASD requires early identification of the factors that influence later behavioural outcomes. One fruitful research paradigm has been the prospective study of infants with a first degree relative with ASD, who have around a 20% likelihood of developing ASD themselves. Early findings have identified a range of candidate neurocognitive markers for later ASD such as delayed attention shifting or neural responses to faces, but given the early stage of the field most sample sizes are small and replication attempts remain rare. The Eurosibs consortium is a European multisite neurocognitive study of infants with an older sibling with ASD conducted across nine sites in five European countries. In this manuscript, we describe the selection and standardization of our common neurocognitive testing protocol. We report data quality assessments across sites, showing that neurocognitive measures hold great promise for cross-site consistency in diverse populations. We discuss our approach to ensuring robust data analysis pipelines and boosting future reproducibility. Finally, we summarise challenges and opportunities for future multi-site research efforts

    Cross-Cultural Validation of the York Measure of Quality of Intensive Behavioral Intervention

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    © 2017, © The Author(s) 2017. Early intensive behavioral intervention (EIBI) is widely ap plied in young children with autism spectrum disorder. Little research has addressed the significance of adherence to EIBI practices for treatment outcomes. The York Measure of Quality of Intensive Behavioral Intervention (YMQI) was designed to assess EIBI quality delivery in Ontario, Canada. The objective of this study was to examine the cross-cultural validity of the YMQI in a clinical Swedish community sample of 30 boys and four girls with autism aged 2.5 to 6 years. Internal consistency was alpha =.87 for the full scale YMQI. Interrater reliability among three raters on 97 video-recorded therapy sequences was.71 (intraclass correlation coefficient [ICC]), and intrarater reliability of two raters re-scoring 15 sequences after 6 months was ICC =.87. The convergent validity of the YMQI with EIBI expert ratings was r =.49. Findings endorse the psychometric properties of the YMQI and its usability outside of Anglo-Saxon countries

    Cross-Cultural Validation of the York Measure of Quality of Intensive Behavioral Intervention

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    © 2017, © The Author(s) 2017. Early intensive behavioral intervention (EIBI) is widely ap plied in young children with autism spectrum disorder. Little research has addressed the significance of adherence to EIBI practices for treatment outcomes. The York Measure of Quality of Intensive Behavioral Intervention (YMQI) was designed to assess EIBI quality delivery in Ontario, Canada. The objective of this study was to examine the cross-cultural validity of the YMQI in a clinical Swedish community sample of 30 boys and four girls with autism aged 2.5 to 6 years. Internal consistency was alpha =.87 for the full scale YMQI. Interrater reliability among three raters on 97 video-recorded therapy sequences was.71 (intraclass correlation coefficient [ICC]), and intrarater reliability of two raters re-scoring 15 sequences after 6 months was ICC =.87. The convergent validity of the YMQI with EIBI expert ratings was r =.49. Findings endorse the psychometric properties of the YMQI and its usability outside of Anglo-Saxon countries

    Reduced prospective motor control in 10-month-olds at risk for autism spectrum disorder

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    Motor impairments are not a part of the diagnostic criteria for autism spectrum disorder (ASD) but are overrepresented in the ASD population. Deficits in prospective motor control have been demonstrated in adults and older children with ASD but have never before been examined in infants at familial risk for the disorder. We assessed the ability to prospectively control reach-to-grasp actions in 10-month-old siblings of children with ASD (high-risk group, n = 29, 13 female) as well as in a low-risk control group (n = 16, 8 female). The task was to catch a ball rolling on a curvilinear path off an inclined surface. The low-risk group performed predictive reaches when catching the ball, whereas the high-risk group started their movements reactively. The high-risk group started their reaches significantly later than the low-risk group (p = .03). These results indicate impaired prospective motor control in infants susceptible for ASD
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