Assessment and diagnosis of Developmental Language Disorder: The experiences of speech and language therapists

© The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (http://www.creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).Background: For many years research and practice have noted the impact of the heterogeneous nature of Developmental Language Disorder (also known as language impairment or specific language impairment) on diagnosis and assessment. Recent research suggests the disorder is not restricted to the language domain and against this background, the challenge for the practitioner is to provide accurate assessment and effective therapy. The language practitioner aims to support the child and their carers to achieve the best outcomes. However, little is known about the experiences of the language practitioner in the assessment process, in contrast to other childhood disorders, yet their expertise is central in the assessment and diagnosis of children with language disorder. Aims: This study aimed to provide a detailed qualitative description of the experiences of speech and language therapists involved in the assessment and diagnosis of children with Developmental Language Disorder. Methods & Procedures: The qualitative study included three focus groups to provide a credible and rich description of the experiences of speech and language therapists involved in the assessment of Developmental Language Disorder. The speech and language therapists who participated in the study were recruited from three NHS Trusts across the UK and all were directly involved in the assessment and diagnosis procedures. The lengths of practitioner experience ranged from 2 years to 38 years. The data was analysed using a thematic analysis in accordance with the principles set out by Braun & Clarke (2006). Outcomes & Results: The data showed a number of key themes concerning the experiences of speech and language therapists in assessing children with Developmental Language Disorder (DLD). These themes ranged from the participants’ experiences of the barriers to early referral, challenges for assessment and the concerns over continued future support. Conclusions & Implications: This study provides first-hand evidence from speech and language therapists in the assessment of children with Developmental Language Disorder, drawing together experiences from language practitioners from different regions. The findings provide insight to the barriers to referral, the potential variations in the assessment process, the role of practitioner expertise and the challenges faced them. The importance of early intervention, useful assessment tools and future support were expressed. Taken together, the results relate to some issues to be addressed on a practical level and a continuing need for initiatives to raise awareness of DLD in the public domain.Peer reviewe

Assessing dental wear in reindeer using geometric morphometrical methods

Assessing dental wear is a useful tool for monitoring the interaction between ungulates and their food resources. However, using a univariate measurement for dental wear, like for instance height of the first molar may not capture the variation in dental wear important for the dental functional morphology. We here demonstrate a method for assessing dental wear for ungulates by using geometric morphometrical methods on 11 mandibles from nine Svalbard reindeer (Rangifer tarandus platyrhynchus). Shape measurements were obtained from a combination of fixed and sliding semi-landmarks, and dental wear was estimated using residual variation of the landmarks. The morphometric measurements obtained showed a good fit when compared to subjective scores of dental wear. We conclude that this method may give a more integrated and robust assessment of dental wear than univariate methods, and suggest it to be used as an alternative or in addition to traditional measurements of dental wear.Abstract in Norwegian / Sammendrag:Vurdering av tannslitasje hos rein ved hjelp av geometrisk morfometriske metoder Vurdering av tannslitasje er en anvendbar metode for å overvåke betydningen av miljøet for livshistorien til hovdyr. Imidlertid vil bruk av et enkelt mål, som for eksempel høyde på første molar, ikke nødvendigvis fange opp variasjonen i tannslitasje som er viktig i forhold til tennenes funksjonelle morfologi. I denne artikkelen viser vi hvordan tannslitasje kan vurderes ved å anvende geometrisk morfometriske metoder på 11 underkjever fra ni Svalbardrein (Rangifer tarandus platyrhynchus). Formen på tannrekka ble målt ved hjelp av en kombinasjon av fikserte og glidende semi-landemerker, hvor tannslitasje ble estimert ved å bruke residual variasjon av landemerkene. De morfometriske målene stemte godt overens med subjektiv vurdering av tannslitasje. Vi konkluderer at denne metoden kan gi en mer integrert og robust vurdering av tannslitasje enn univariate metoder, og foreslår den brukt som et alternativ til eller i tillegg til mer tradisjonelle mål på tannslitasje

Structure of Precursor-Bound NifEN: A Nitrogenase FeMo Cofactor Maturase/Insertase

NifEN plays an essential role in the biosynthesis of the nitrogenase iron-molybdenum (FeMo) cofactor (M cluster). It is an α_2β_2 tetramer that is homologous to the catalytic molybdenum-iron (MoFe) protein (NifDK) component of nitrogenase. NifEN serves as a scaffold for the conversion of an iron-only precursor to a matured form of the M cluster before delivering the latter to its target location within NifDK. Here, we present the structure of the precursor-bound NifEN of Azotobacter vinelandii at 2.6 angstrom resolution. From a structural comparison of NifEN with des-M-cluster NifDK and holo NifDK, we propose similar pathways of cluster insertion for the homologous NifEN and NifDK proteins

Genome-wide association study of receptive language ability of 12 year olds

Purpose: We have previously shown that individual differences in measures of receptive language ability at age 12 are highly heritable. The current study attempted to identify some of the genes responsible for the heritability of receptive language ability using a genome-wide association (GWA) approach. Method: We administered four internet-based measures of receptive language (vocabulary, semantics, syntax, and pragmatics) to a sample of 2329 12-year-olds for whom DNA and genome-wide genotyping were available. Nearly 700,000 single-nucleotide polymorphisms (SNPs) and one million imputed SNPs were included in a GWA analysis of receptive language composite scores. Results: No SNP associations met the demanding criterion of genome-wide significance that corrects for multiple testing across the genome (p < 5 ×10-8). The strongest SNP association did not replicate in an additional sample of 2639 12-year-olds. Conclusion: These results indicate that individual differences in receptive language ability in the general population do not reflect common genetic variants that account for >3% of the phenotypic variance. The search for genetic variants associated with language skill will require larger samples and additional methods to identify and functionally characterize the full spectrum of risk variants

The use of Global Positioning Systems to record distances in a helicopter line-transect survey

Methods that allow unbiased estimation of animal abundance are increasingly demanded in management and conservation. The use of these methods should respect their assumptions. The need for accurate distance measurements in distance-sampling surveys is stressed. Here we present 2 alternative methods for measuring distance from a line to an object during helicopter surveys: 1) using a Global Positioning System (GPS) unit, with distances measured using appropriate software; and 2) recording declination angles and altitudes, using basic trigonometry to obtain the appropriate distances. These are compared to distances measured by a laser rangefinder (assumed to be true distances). The effect of the different errors on estimated densities is assessed by simulation. The GPS method appeared to be very accurate, while a potential downward bias in estimated density could be present if the inclinometer method is used. We discuss the implication for wildlife studies of using different measurement methods leading to different errors.</p

Mitogenomics and the genetic differentiation of contemporary <i>Balaena mysticetus</i> (Cetacea) from Svalbard

Full mitochondrial genomes were assembled for 12 recently sampled animals from the Svalbard bowhead whale (Balaena mysticetus) stock via high-throughput sequencing data, facilitating analysis of the demographic history of the population for the first time. The Svalbard population has retained noticeable amounts of mitochondrial genome diversity despite extreme historical harvest levels. Haplotype and nucleotide diversities were similar to those estimated earlier for other bowhead whale populations. The reconstructed demographic history was in accordance with a boom–bust scenario, combining a slight Pleistocene population growth 25 000–35 000 years ago and a Holocene decline. Employing a mutation rate of 3.418 × 10–8 substitutions per site per year, the time to the most recent common ancestor for the mitochondrial genomes of the contemporary Svalbard bowhead whales was estimated to be 68 782 (54 353–83 216) years before the present. Based on 370 bp fragments of the D-loop region, significant genetic differentiation was detected between all extant bowhead whale populations across the circumpolar Arctic. Thus, the Svalbard bowhead whales can be regarded as a population with its own genetic legacy

Lexicality and frequency in specific language impairment: accuracy and error data from two nonword repetition tests

Purpose: Deficits in phonological working memory and deficits in phonological processing have both been considered potential explanatory factors in Specific Language Impairment (SLI). Manipulations of the lexicality and phonotactic frequency of nonwords enable contrasting predictions to be derived from these hypotheses. Method: 18 typically developing (TD) children and 18 children with SLI completed an assessment battery that included tests of language ability, non-verbal intelligence, and two nonword repetition tests that varied in lexicality and frequency. Results: Repetition accuracy showed that children with SLI were unimpaired for short and simple high lexicality nonwords, whereas clear impairments were shown for all low lexicality nonwords. For low lexicality nonwords, greater repetition accuracy was seen for nonwords constructed from high over low frequency phoneme sequences. Children with SLI made the same proportion of errors that substituted a nonsense syllable for a lexical item as TD children, and this was stable across nonword length. Conclusions: The data show support for a phonological processing deficit in children with SLI, where long-term lexical and sub-lexical phonological knowledge mediate the interpretation of nonwords. However, the data also suggest that while phonological processing may provide a key explanation of SLI, a full account is likely to be multi-faceted