Shaping electron wave functions in a carbon nanotube with a parallel magnetic field

A magnetic field, through its vector potential, usually causes measurable changes in the electron wave function only in the direction transverse to the field. Here we demonstrate experimentally and theoretically that in carbon nanotube quantum dots, combining cylindrical topology and bipartite hexagonal lattice, a magnetic field along the nanotube axis impacts also the longitudinal profile of the electronic states. With the high (up to 17T) magnetic fields in our experiment the wave functions can be tuned all the way from "half-wave resonator" shape, with nodes at both ends, to "quarter-wave resonator" shape, with an antinode at one end. This in turn causes a distinct dependence of the conductance on the magnetic field. Our results demonstrate a new strategy for the control of wave functions using magnetic fields in quantum systems with nontrivial lattice and topology.Comment: 5 figure

A Developmental Approach to Machine Learning?

Visual learning depends on both the algorithms and the training material. This essay considers the natural statistics of infant- and toddler-egocentric vision. These natural training sets for human visual object recognition are very different from the training data fed into machine vision systems. Rather than equal experiences with all kinds of things, toddlers experience extremely skewed distributions with many repeated occurrences of a very few things. And though highly variable when considered as a whole, individual views of things are experienced in a specific order – with slow, smooth visual changes moment-to-moment, and developmentally ordered transitions in scene content. We propose that the skewed, ordered, biased visual experiences of infants and toddlers are the training data that allow human learners to develop a way to recognize everything, both the pervasively present entities and the rarely encountered ones. The joint consideration of real-world statistics for learning by researchers of human and machine learning seems likely to bring advances in both disciplines

Williams syndrome: a surprising deficit in oromotor praxis in a population with proficient language production

Williams Syndrome (WS) is a neurodevelopmental disorder of known genetic origin, characterized by serious delays in language onset yet relatively verbose, intelligible and fluent speech in late childhood and adulthood. How do motor abilities relate to language in this group? We investigated planning and co-ordination of the movement of the speech articulators (oromotor praxis) in 28 fluent-speaking individuals with WS, aged between 12–30 years. Results indicate that, despite their fluent language, oromotor praxis was impaired in WS relative to two groups of typically-developing children, matched on either vocabulary or visuospatial ability. These findings suggest that the ability to plan, co-ordinate and execute complex sensorimotor movements contribute to an explanation of the delay in expressive language early in development in this neurodevelopmental disorder. In the discussion, we turn to more general issues of how individual variation in oromotor praxis may account for differences in speech/language production abilities across developmental language disorders

Emotional and behavioural problems in children with Developmental Coordination Disorder: exploring parent and teacher reports

Background: Although characterised by motor impairments, children with Developmental Coordination Disorder (DCD) also show high rates of psychopathology (anxiety, depression, low self-esteem). Such findings have led to calls for the screening of mental health problems in this group. Aims: To investigate patterns and profiles of emotional and behavioural problems in children with and without DCD, using the Strengths and Difficulties Questionnaire (SDQ). Methods and Procedures: Teachers and parents completed SDQs for 30 children with DCD (7-10 years). Teacher ratings on the SDQ were also obtained from two typically-developing (TD) groups: 35 children matched for chronological age, and 29 younger children (4-7 years) matched by motor ability. Outcomes and Results: Group and individual analyses compared parent and teacher SDQ scores for children with DCD. Teacher reports showed that children with DCD displayed higher rates of emotional and behavioural problems (overall, and on each subscale of the SDQ) relative to their TD peers. No differences were observed between the two TD groups. Inspection of individual data points highlighted variability in the SDQ scores of the DCD group (across both teacher and parent ratings), with suggestions of elevated hyperactivity but comparably lower levels of conduct problems across this sample. Modest agreement was found between teacher and parent ratings of children with DCD on the SDQ. Conclusions and Implications: There is a need to monitor levels of emotional and behavioural problems in children with DCD, from multiple informants

Baby-led weaning in Italy and potential implications for infant development

Baby-led weaning is an approach to complementary feeding that emphasizes an infant's ability to self-feed rather than being spoon fed, and to eat minimally-processed foods rather than puréed foods. This study aimed to investigate the variability in infant feeding practices and the possible association with developmental milestones in an Italian population. A sample of 1245 mothers of 6-12 month-old infants completed an online survey about complementary feeding and their infant's attainment of developmental milestones. Infants' eating of family food was positively related to self-feeding and to a lower consumption of puréed foods. As in previous studies in the UK and New Zealand, a baby-led weaning style was positively associated with breastfeeding, exposure to complementary foods around six months of age, earlier exposure to both finger and family foods, and higher interest in family food and shared family meals. Infants who were introduced to solid foods using a baby-led weaning approach were more likely to have met important developmental milestones; when controlling for covariates, percentage of family feeding was positively associated with sitting unsupported at an earlier age and a low spoon-feeding style was associated with crawling at an earlier age. These data suggest that baby-led weaning should be defined more comprehensively. Moreover, its potential influence on developmental domains beyond diet and eating behavior warrants future targeted exploration. [Abstract copyright: Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Predicting the rate of language development from early motor skills in at-risk infants who develop autism spectrum disorder

The aim of the current paper was to use data from a prospective study to assess the impact of early motor skills on the rate of language development in infants with an older sibling with Autism Spectrum Disorder (ASD), who are at increased risk of developing ASD themselves. Infants were tested prospectively at four points (7, 14, 24 and 36 months), and were assessed for ASD at the last visit. Latent growth curve analysis was used to model rate of language development using the Vineland Adaptive Behavior Scales between 7-36 months in infants at high and low familial risk for ASD. Motor scores from the Mullen Scales of Early Learning at 7 months were used as predictors of language growth. Gross motor scores predicted the subsequent rate of expressive, but not receptive, language development in at-risk siblings who were later diagnosed with ASD. Although the pattern was similar for fine motor skills, the relationship did not reach significance. It seems that early motor delay impacts the rate of development of expressive language, and this may be of particular importance to infants at increased risk of developing ASD

An infant‐led approach to complementary feeding is positively associated with language development

The timing and strategy with which parents first introduce their infants to solid foods may be an important predictor of subsequent developmental outcomes. Recent years have seen a decline in the prevalence of traditional parent‐led feeding of soft, puréed food and a rise in the prevalence of infant‐led complementary feeding. Although there has been some research espousing the benefits of infant‐led complementary feeding for improving food fussiness and self‐regulation, there has been little exploration of this approach that may impact on other developmental outcomes in children. The current study explores whether aspects of the infant‐led approach, specifically the child eating unaided and consuming finger foods and eating with the family, are related to child language outcomes. One hundred thirty one parents of children aged 8–24 months completed questionnaires about their approach to complementary feeding, their current feeding practices, their child's experiences with family foods and child language comprehension/production. The findings suggest that an approach to complementary feeding which promotes infant autonomy in feeding (i.e., eating finger foods rather than puréed foods) and consuming more family foods is related to more advanced child language production and comprehension. Specifically, the prevalence of eating family foods mediated the relationship between eating unaided at the onset of the complementary feeding period and later language outcomes. This study is the first to find a significant relationship between different approaches to introducing solid foods and child language outcomes and these findings highlight the potential for different complementary feeding approaches to influence behaviour beyond mealtimes

Overlapping phenotypes in autism spectrum disorder and developmental coordination disorder: A cross-syndrome comparison of motor and social skills

Motor and social difficulties are often found in children with an autism spectrum disorder (ASD) and with developmental coordination disorder (DCD), to varying degrees. This study investigated the extent of overlap of these problems in children aged 7-10 years who had a diagnosis of either ASD or DCD, compared to typically-developing controls. Children completed motor and face processing assessments. Parents completed questionnaires concerning their child’s early motor and current motor and social skills. There was considerable overlap between the ASD and DCD groups on the motor and social assessments, with both groups more impaired than controls. Furthermore, motor skill predicted social functioning for both groups. Future research should consider the relationships between core symptoms and their consequences in other domains

PAPER Fine motor skill predicts expressive language in infant siblings of children with autism

Abstract We investigated whether fine motor and expressive language skills are related in the later-born siblings of children with autism (heightened-risk, HR infants) who are at increased risk for language delays. We observed 34 HR infants longitudinally from 12 to 36 months. We used parent report and standardized observation measures to assess fine motor skill from 12 to 24 months in HR infants (Study 1) and its relation to later expressive vocabulary at 36 months in HR infants (Study 2). In Study 1, we also included 25 infants without a family history of autism to serve as a normative comparison group for a parent-report fine motor measure. We found that HR infants exhibited fine motor delays between 12 and 24 months and expressive vocabulary delays at 36 months. Further, fine motor skill significantly predicted expressive language at 36 months. Fine motor and expressive language skills are related early in development in HR infants, who, as a group, exhibit risk for delays in both. Our findings highlight the importance of considering fine motor skill in children at risk for language impairments and may have implications for early identification of expressive language difficulties. Research highlights • Previous research shows that later-born siblings of children with autism (high-risk, HR) are at heightened risk for autism spectrum disorders (ASD); and those with no later ASD diagnosis are still at risk for expressive language delays. Fine motor skill may be an early predictor of later delays. • In our study, HR infants exhibited fine motor delays in the first 24 months and this was observed both in HR infants who later received an ASD diagnosis themselves at 36 months as well as those who did not. • Nonetheless, fine motor delays were more pronounced and persistent for HR infants with a later ASD diagnosis than for those without. • Fine motor skills predicted later expressive language at 36 months even when controlling for ASD diagnostic outcome