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

Testing a word is not a test of word learning

Although vocabulary acquisition requires children learn names for multiple things, many investigations of word learning mechanisms teach children the name for only one of the objects presented. This is problematic because it is unclear whether children's performance reflects recall of the correct name-object association or simply selection of the only object that was singled out by being the only object named. Children introduced to one novel name may perform at ceiling as they are not required to discriminate on the basis of the name per se, and appear to rapidly learn words following minimal exposure to a single word. We introduced children to four novel objects. For half the children, only one of the objects was named and for the other children, all four objects were named. Only children introduced to one word reliably selected the target object at test. This demonstration highlights the over-simplicity of one-word learning paradigms and the need for a shift in word learning paradigms where more than one word is taught to ensure children disambiguate objects on the basis of their names rather than their degree of salience

What Our Hands Say: Exploring Gesture Use in Subgroups of Children With Language Delay

Purpose The aim of this study was to investigate whether children with receptive-expressive language delay (R/ELD) and expressive-only language delay (ELD) differ in their use of gesture; to examine relationships between their use of gesture, symbolic comprehension, and language; to consider implications for assessment and for the nature of problems underlying different profiles of early language delay. Method Twelve children with ELD (8 boys, 4 girls) and 10 children with R/ELD (8 boys, 2 girls), aged 2–3 years, were assessed on measures of gesture use and symbolic comprehension. Results Performance of the R/ELD group was significantly poorer than performance of the ELD group on measures of gesture and symbolic comprehension. Gesture use and symbolic comprehension were significantly associated with receptive language, but associations with expressive language were not significant. Conclusions Findings of this study support previous research pointing to links between gesture and language development, and more specifically, between delays in gesture, symbolic understanding, and receptive rather than expressive language. Given potentially important implications for the nature of problems underlying ELD and R/ELD, and for assessment of children with language delay, this preliminary study invites further investigation comparing the use of different gesture types in samples of children matched on age and nonverbal IQ

Adaptation of a Vocabulary Test from British Sign Language to American Sign Language

This study describes the adaptation process of a vocabulary knowledge test for British Sign Language (BSL) into American Sign Language (ASL) and presents results from the first round of pilot testing with twenty deaf native ASL signers. The web-based test assesses the strength of deaf children’s vocabulary knowledge by means of different mappings of phonological form and meaning of signs. The adaptation from BSL to ASL involved nine stages, which included forming a panel of deaf/hearing experts, developing a set of new items and revising/replacing items considered ineffective, and piloting the new version. Results provide new evidence in support of the use of this methodology for assessing sign language, making a useful contribution toward the availability of tests to assess deaf children’s signed language skills

Investigating Use of a Parent Report Tool to Measure Vocabulary Development in Deaf Greek-speaking Children with Cochlear Implants

Objective: There are very few measures of language development in spoken Greek that can be used with young deaf children. This study investigated the use of Cyprus Lexical List (CYLEX), a receptive and expressive vocabulary assessment based on parent report that has recently been adapted to Standard Greek, to measure the vocabulary development of deaf Greek-speaking children with cochlear implants. Design: A Standard Greek version of CYLEX was used to collect data on receptive and expressive vocabulary development from parents of thirteen deaf children with cochlear implants aged between 21 and 71 months. These data were compared with data collected previously from typically developing hearing Greek-speaking children. Results: Use of the test by parents of deaf children was found to be reliable. No correlation was found between children's vocabulary scores and chronological age. A positive correlation was however found between children's post-implant age and expressive vocabulary. The vocabulary skills of implanted children with a mean post-implant age of 20 months were not significantly different from those of typically developing hearing children of similar chronological age. Conclusion: CYLEX is a reliable and useful tool for exploring vocabulary development with this clinical group. Findings confirm the results of other studies in indicating that the vocabulary size of implanted pre-school-aged deaf children is related to the amount of time that children have used their implant, rather than chronological age

Lexical, morphological and syntactic development in toddlers between 16 and 30 months old: a comparison across European Portuguese and Galician

The main aims of this study were to investigate the relationship between the lexical size and the emergence of morphological and syntactic markers in toddlers between the ages of 16 and 30 months and to compare these results between Galician and European Portuguese. Parents of 3012 Portuguese toddlers and those of 1081 Galician toddlers completed the MacArthur–Bates Communicative Development Inventory: Words and Sentences. The results indicated that the number of words, the ability to combine words and the number of different morphemes produced increased with age. The ability to combine words was used as an indicator of syntactic development; this ability was also associated with the toddlers’ lexical size. In both samples, gender morphemes seemed to be the first to have their production generalized, followed by the plural and the past participle. The production of gender morphemes was accompanied by a small lexical size, whereas the imperfect tense and the person mark onset were associated with large lexical sizes. The implications of these results for charting the continuity between lexical, morphological and syntactical development are discussed.CiPsi - Psychology Research Centre, Uminho (UID/PSI/ 01662/2013), Portugal. National Funds through the FCT (Foundation for Science and Technology) and co-financed by European Regional Development Funds (FEDER) through the the National Strategic Reference Framework (QREN) - FCOMP- 01-0124-FEDER-029556 and through the Competitiveness and Internationalization Operational Program (POCI) with the references and POCI-01-0145-FEDER-007562CIEC – Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), Portugal. BPD/102549/2014info:eu-repo/semantics/publishedVersio

Using an Observational Framework to investigate adult language input to young children in a naturalistic environment

The correlation between the communicative intent of parents, in terms of their expectation of a response and the response patterns of young children aged 23—25 months during parent—child interactions, was investigated. An Observational Framework was used to code these parameters in interactions between 36 children and their mothers. The children were assigned by cluster analysis to `advanced', `typical' and `delayed' language groups and their responses were coded with respect to the degree of correctness or appropriateness within the interaction. Differences in both the parental response expectations and the children's response patterns across the three clusters are discussed

Common variation near ROBO2 is associated with expressive vocabulary in infancy

Twin studies suggest that expressive vocabulary at ~24 months is modestly heritable. However, the genes influencing this early linguistic phenotype are unknown. Here we conduct a genome-wide screen and follow-up study of expressive vocabulary in toddlers of European descent from up to four studies of the EArly Genetics and Lifecourse Epidemiology consortium, analysing an early (15–18 months, ‘one-word stage’, NTotal=8,889) and a later (24–30 months, ‘two-word stage’, NTotal=10,819) phase of language acquisition. For the early phase, one single-nucleotide polymorphism (rs7642482) at 3p12.3 near ​ROBO2, encoding a conserved axon-binding receptor, reaches the genome-wide significance level (P=1.3 × 10−8) in the combined sample. This association links language-related common genetic variation in the general population to a potential autism susceptibility locus and a linkage region for dyslexia, speech-sound disorder and reading. The contribution of common genetic influences is, although modest, supported by genome-wide complex trait analysis (meta-GCTA h215–18-months=0.13, meta-GCTA h224–30-months=0.14) and in concordance with additional twin analysis (5,733 pairs of European descent, h224-months=0.20)

Ratunku! or just tunku! : evidence for the reliability and concurrent validity of the Language Use Inventory : LUI-Polish

Purpose: To date, there is no tool for assessing early pragmatic development of Polish-speaking children. This study aimed to adapt to Polish a standardized parent report measure, the Language Use Inventory (LUI; O’Neill, 2009, in order to enable cross-cultural comparisons and to use the LUI-Polish to screen for pragmatic development in children 18-47 months of age. We concentrated on the sociocultural and functional adaptation of LUI and aimed to demonstrate its reliability, developmental sensitivity, and concurrent validity. Method: Parents completed an online version of LUIPolish, longitudinally at 3 time points (when the child was 20, 32, and 44 months old). In addition, parents completed the Polish adaptations of the Questionnaire for Communication and Early Language at 22 months and the Language Development Survey at 24 months. Children’s spontaneous speech was assessed at 24 months, and their expressive and receptive vocabulary was assessed at 36 months. Results: All 3 parts of the LUI-Polish (Gestures, Words, and Sentences) showed very good levels of internal consistency at each time point. Significant correlations were observed between all parts of the LUI-Polish at all 3 measurement time points. The expected developmental trajectory was observed for boys and girls providing evidence of its developmental sensitivity for children between the ages of 2 and 4 years: an increase with age in the total score (due to an increase in Words and Sentences) and a decrease in Gestures. Supporting concurrent validity, significant correlations were found between children’s performance on (a) the LUI-Polish at 20 months and the Questionnaire for Communication and Early Language at 22 months as well as the Language Development Survey and spontaneous speech measures at 24 months and (b) the LUI-Polish at 32 months and the 2 measures of vocabulary comprehension and production at 36 months. Conclusion: The Polish adaptation of the LUI demonstrated good psychometric properties that provide a sound basis for cross-cultural comparisons and further research toward norming of the LUI-Polish. Moreover, the expected developmental trajectory in the pragmatic development of Polish children was observed