7,850 research outputs found
Recommended from our members
The first signs of language: Phonological development in British sign language
A total of 1018 signs in one deaf child’s naturalistic interaction with her deaf mother, between the ages 19-24 months were analysed. This study summarises regular modification processes in the phonology of the child sign’s handshape, location, movement and prosody. Firstly changes to signs were explained by the notion of phonological markedness. Secondly, the child managed her production of first signs through two universal processes: structural change and substitution. Constraints unique to the visual modality also caused sign language specific acquisition patterns, namely: more errors for handshape articulation in locations in peripheral vision, a high frequency of whole sign repetitions and feature group rather than one-to-one phoneme substitutions as in spoken language development
Recommended from our members
Expressive vocabulary predicts non-verbal executive function: a 2-year longitudinal study of deaf and hearing children
Numerous studies suggest an association between language and executive function (EF), but evidence of a developmental relationship remains inconclusive. Data were collected from 75 deaf/hard-of-hearing (DHH) children and 82 hearing age-matched controls. Children were 6-11 years old at first time of testing, and completed a battery of nonverbal EF tasks and a test of expressive vocabulary. These tasks were completed again two years later. Both groups improved their scores on all tasks over this period. DHH children performed significantly less well than hearing peers on some EF tasks and the vocabulary test at both time points. Cross-lagged panel models showed that vocabulary at Time 1 predicted change in EF scores for both DHH and hearing children but not the reverse
High throughput particle analysis: combining dielectrophoretic particle focussing with confocal optical detection
A microflow cytometer has been fabricated that detects and counts fluorescent particles flowing through a microchannel at a high speed based upon their fluorescence emission intensity. Dielectrophoresis is used to continuously focus particles within the flowing fluid stream into the centre of the device, which is 40 μm high and 250 μm wide. The method ensures that all the particles pass through an interrogation region approximately 5 μm in diameter, which is created by focusing a beam of light into a spot. The functioning of the device was demonstrated by detecting and counting fluorescent latex particles at a rate of up to 250 particles/s. A mixture of three different populations of latex particle was used, each sub-population with a distinct level of fluorescent intensity. The device was evaluated by comparison with a conventional fluorescent activated cell sorter (FACS) and numerical simulation demonstrated that for 6 mico m beads, and for this design of chip the theoretical throughput is of the order of 1000 particles/s (corresponding to a particle velocty of 1 mm/s)
Superconducting Diamond on Silicon Nitride for Device Applications
Chemical vapour deposition (CVD) grown nanocrystalline diamond is an
attractive material for the fabrication of devices. For some device
architectures, optimisation of its growth on silicon nitride is essential.
Here, the effects of three pre-growth surface treatments, often employed as
cleaning methods of silicon nitride, were investigated. Such treatments provide
control over the surface charge of the substrate through modification of the
surface functionality, allowing for the optimisation of electrostatic diamond
seeding densities. Zeta potential measurements and X-ray photoelectron
spectroscopy (XPS) were used to analyse the silicon nitride surface following
each treatment. Exposing silicon nitride to an oxygen plasma offered optimal
surface conditions for the electrostatic self-assembly of a hydrogen-terminated
diamond nanoparticle monolayer. The subsequent growth of boron-doped
nanocrystalline diamond thin films on modified silicon nitride substrates under
CVD conditions produced coalesced films for oxygen plasma and solvent
treatments, whilst pin-holing of the diamond film was observed following RCA-1
treatment. The sharpest superconducting transition was observed for diamond
grown on oxygen plasma treated silicon nitride, demonstrating it to be of the
least structural disorder. Modifications to the substrate surface optimise the
seeding and growth processes for the fabrication of diamond on silicon nitride
devices
Semantic fluency in deaf children who use spoken and signed language in comparison with hearing peers
BACKGROUND: Deafness has an adverse impact on children's ability to acquire spoken languages. Signed languages offer a more accessible input for deaf children, but because the vast majority are born to hearing parents who do not sign, their early exposure to sign language is limited. Deaf children as a whole are therefore at high risk of language delays. AIMS: We compared deaf and hearing children's performance on a semantic fluency task. Optimal performance on this task requires a systematic search of the mental lexicon, the retrieval of words within a subcategory and, when that subcategory is exhausted, switching to a new subcategory. We compared retrieval patterns between groups, and also compared the responses of deaf children who used British Sign Language (BSL) with those who used spoken English. We investigated how semantic fluency performance related to children's expressive vocabulary and executive function skills, and also retested semantic fluency in the majority of the children nearly 2 years later, in order to investigate how much progress they had made in that time. METHODS & PROCEDURES: Participants were deaf children aged 6-11 years (N = 106, comprising 69 users of spoken English, 29 users of BSL and eight users of Sign Supported English-SSE) compared with hearing children (N = 120) of the same age who used spoken English. Semantic fluency was tested for the category 'animals'. We coded for errors, clusters (e.g., 'pets', 'farm animals') and switches. Participants also completed the Expressive One-Word Picture Vocabulary Test and a battery of six non-verbal executive function tasks. In addition, we collected follow-up semantic fluency data for 70 deaf and 74 hearing children, nearly 2 years after they were first tested. OUTCOMES & RESULTS: Deaf children, whether using spoken or signed language, produced fewer items in the semantic fluency task than hearing children, but they showed similar patterns of responses for items most commonly produced, clustering of items into subcategories and switching between subcategories. Both vocabulary and executive function scores predicted the number of correct items produced. Follow-up data from deaf participants showed continuing delays relative to hearing children 2 years later. CONCLUSIONS & IMPLICATIONS: We conclude that semantic fluency can be used experimentally to investigate lexical organization in deaf children, and that it potentially has clinical utility across the heterogeneous deaf population. We present normative data to aid clinicians who wish to use this task with deaf children
The caries experience of 5 year-old children in Scotland in 2013-2014, and in England and Wales in 2014-2015. Reports of cross-sectional dental surveys using BASCD criteria
Objective: We report the findings from and comment on the surveys of the oral health of 5-year-old children undertaken in Scotland
(2013-14), Wales (2014-15) and England (2014-15). This was the fourteenth survey in Scotland since 1988. In England and Wales it is the
third survey since 2007 when changes were required in consent arrangements. Method: Representative samples were drawn within Health
Boards across Scotland and local authorities across England and Wales. Consent was sought via opt-out parental consent in Scotland and
opt-in parental consent in England and Wales. Children examined were those aged five in England and those in Primary 1 (school year
aged 5 to 6) in Scotland and Wales. Examinations were conducted in schools by trained and calibrated examiners. Caries was visually
diagnosed at the dentinal threshold. Results: There is a continuing decline in d3mft in all three countries. d3mft was 1.27 (opt-out consent)
for Scotland, 0.84 for England (opt-in consent) and 1.29 for Wales (opt-in consent). Tooth decay levels remain higher in more deprived
areas across Great Britain, with clear inequalities gradients demonstrated across all geographies. Attempts to measure changes in dental
health inequalities across the three countries show no conclusive trends. Conclusion: Inter-country comparisons provide further oral health
intelligence despite differences in approach and timing. The third surveys in England and Wales using the new consent arrangements
have enabled trend analysis. Dental health inequalities gradients were shown across all geographies and all of the indicators of inequalit
Chandra X-ray Observations of the Quadruply Lensed Quasar RX J0911.4+0551
We present results from X-ray observations of the quadruply lensed quasar RX
J0911.4+0551 using data obtained with the Advanced CCD Imaging Spectrometer
(ACIS) on board the Chandra X-ray Observatory. The 29 ks observation detects a
total of ~404 X-ray photons (0.3 to 7.0 keV) from the four images of the lensed
quasar. Deconvolution of the aspect corrected data resolves all four lensed
images, with relative positions in good agreement with optical measurements.
When compared to contemporaneous optical data, one of the lensed images
(component A3) is dimmer by a factor of ~6 in X-rays with respect to the 2
brighter images (components A1 and A2). Spectral fitting for the combined
images shows significant intrinsic absorption in the soft (0.2 to 2.4 keV)
energy band, consistent with the mini-BAL nature of this quasar, while a
comparison with ROSAT PSPC observations from 1990 shows a drop of ~6.5 in the
total soft bandpass flux. The observations also detect ~157 X-ray photons
arising from extended emission of the nearby cluster (peaked ~42" SW of
RXJ0911.4+0551) responsible for the large external shear present in the system.
The Chandra observation reveals the cluster emission to be complex and
non-spherical, and yields a cluster temperature of kT = 2.3^{+1.8}_{-0.8} keV
and a 2.0 to 10 keV cluster luminosity within a 1 Mpc radius of L_X =
7.6_{-0.2}^{+0.6} x 10^{43} ergs/s (error bars denote 90% confidence limits).
Our mass estimate of the cluster within its virial radius is 2.3^{+1.8}_{-0.7}
x 10^{14} solar, and is a factor of 2 smaller than, although consistent with,
previous mass estimates based on the observed cluster velocity dispersion.Comment: 16 pages, 3 figures (figure 1 is color ps). Accepted by Ap
<i>‘What retention’ means to me</i>: the position of the adult learner in student retention
Studies of student retention and progression overwhelmingly appear adopt definitions that place the institution, rather than the student, at the centre. Retention is most often conceived in terms of linear and continuous progress between institutionally identified start and end points.
This paper reports on research that considered data from 38 in-depth interviews conducted with individuals who had characteristics often associated with non-traditional engagement in higher education who between 2006 and 2010 had studied an ‘Introduction to HE’ module at one distance higher education institution, some of whom had progressed to further study at that institution, some of whom had not. The research deployed a life histories approach to seek a finer grained understanding of how individuals conceptualise their own learning journey and experience, in order to reflect on institutional conceptions of student retention.
The findings highlight potential anomalies hidden within institutional retention rates – large proportions of the interview participants who were not ‘retained’ by the institution reported successful progression to and in other learning institutions and environments, both formal and informal. Nearly all described positive perspectives on lifelong learning which were either engendered or improved by the learning undertaken. This attests to the complexity of individuals’ lives and provides clear evidence that institution-centric definitions of retention and progression are insufficient to create truly meaningful understanding of successful individual learning journeys and experiences. It is argued that only through careful consideration of the lived experience of students and a re-conception of measures of retention, will we be able to offer real insight into improving student retention
Incidence of schizophrenia and other psychoses in ethnic minority groups: results from the MRC AESOP Study
Background. The incidence of schizophrenia in the African-Caribbean population in England is reported to be raised. We sought to clarify whether (a) the rates of other psychotic disorders are increased, (b) whether psychosis is increased in other ethnic minority groups, and (c) whether particular age or gender groups are especially at risk.
Method. We identified all people (n=568) aged 16-64 years presenting to secondary services with their first psychotic symptoms in three well-defined English areas (over a 2-year period in Southeast London and Nottingham and a 9-month period in Bristol). Standardized incidence rates and incidence rate ratios (IRR) for all major psychosis syndromes for all main ethnic groups were calculated.
Results. We found remarkably high IRRs for both schizophrenia and manic psychosis in both African-Caribbeans (schizophrenia 9.1, manic psychosis 8.0) and Black Africans (schizophrenia 5.8, manic psychosis 6.2) in men and women. IRRs in other ethnic minority groups were modestly increased as were rates for depressive psychosis and other psychoses in all minority groups. These raised rates were evident in all age groups in our study.
Conclusions. Ethnic minority groups are at increased risk for all psychotic illnesses but African- Caribbeans and Black Africans appear to be at especially high risk for both schizophrenia and mania. These findings suggest that (a) either additional risk factors are operating in African- Caribbeans and Black Africans or that these factors are particularly prevalent in these groups, and that (b) such factors increase risk for schizophrenia and mania in these groups
- …