44 research outputs found
Exome sequencing identifies novel and recurrent mutations in GJA8 and CRYGD associated with inherited cataract
BACKGROUND: Inherited cataract is a clinically important and genetically heterogeneous cause of visual impairment. Typically, it presents at an early age with or without other ocular/systemic signs and lacks clear phenotype-genotype correlation rendering both clinical classification and molecular diagnosis challenging. Here we have utilized trio-based whole exome sequencing to discover mutations in candidate genes underlying autosomal dominant cataract segregating in three nuclear families. RESULTS: In family A, we identified a recurrent heterozygous mutation in exon-2 of the gene encoding γD-crystallin (CRYGD; c.70C > A, p.Pro24Thr) that co-segregated with ‘coralliform’ lens opacities. Families B and C were found to harbor different novel variants in exon-2 of the gene coding for gap-junction protein α8 (GJA8; c.20T > C, p.Leu7Pro and c.293A > C, p.His98Pro). Each novel variant co-segregated with disease and was predicted in silico to have damaging effects on protein function. CONCLUSIONS: Exome sequencing facilitates concurrent mutation-profiling of the burgeoning list of candidate genes for inherited cataract, and the results can provide enhanced clinical diagnosis and genetic counseling for affected families. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40246-014-0019-6) contains supplementary material, which is available to authorized users
Crowdsourced assessment of surgical skill proficiency in cataract surgery
OBJECTIVE: To test whether crowdsourced lay raters can accurately assess cataract surgical skills.
DESIGN: Two-armed study: independent cross-sectional and longitudinal cohorts.
SETTING: Washington University Department of Ophthalmology.
PARTICIPANTS AND METHODS: Sixteen cataract surgeons with varying experience levels submitted cataract surgery videos to be graded by 5 experts and 300+ crowdworkers masked to surgeon experience. Cross-sectional study: 50 videos from surgeons ranging from first-year resident to attending physician, pooled by years of training. Longitudinal study: 28 videos obtained at regular intervals as residents progressed through 180 cases. Surgical skill was graded using the modified Objective Structured Assessment of Technical Skill (mOSATS). Main outcome measures were overall technical performance, reliability indices, and correlation between expert and crowd mean scores.
RESULTS: Experts demonstrated high interrater reliability and accurately predicted training level, establishing construct validity for the modified OSATS. Crowd scores were correlated with (r = 0.865, p \u3c 0.0001) but consistently higher than expert scores for first, second, and third-year residents (p \u3c 0.0001, paired t-test). Longer surgery duration negatively correlated with training level (r = -0.855, p \u3c 0.0001) and expert score (r = -0.927, p \u3c 0.0001). The longitudinal dataset reproduced cross-sectional study findings for crowd and expert comparisons. A regression equation transforming crowd score plus video length into expert score was derived from the cross-sectional dataset (r
CONCLUSIONS: Crowdsourced rankings correlated with expert scores, but were not equivalent; crowd scores overestimated technical competency, especially for novice surgeons. A novel approach of adjusting crowd scores with surgery duration generated a more accurate predictive model for surgical skill. More studies are needed before crowdsourcing can be reliably used for assessing surgical proficiency
Testing the waters: Exploring the teaching of genres in a Cape flats primary school in South Africa
Twenty years after democracy, the legacy of apartheid and hitherto unmet challenges of
resourcing and teacher development are reflected in a severely inequitable and
underperforming education system. This paper focuses on second language writing in the
middle years of schooling when 80% of learners face a double challenge: to move from
‘common sense’ discourses to the more abstract, specialised discourses of school subjects
and, simultaneously, to a new language of learning, in this case English. It describes an
intervention using a systemic functional linguistic (SFL) genre-based pedagogy involving
72 learners and two teachers in a low socio-economic neighbourhood of Cape Town.
Using an SFL analytical framework, we analyse learners’ development in the information
report genre. All learners in the intervention group made substantial gains in control of
staging, lexis, and key linguistic features. We argue that the scaffolding provided by SFL
genre-based pedagogies together with their explicit focus on textual and linguistic
features offer a means of significantly enhancing epistemic access to the specialised
language of school subjects, particularly for additional language learners. Findings have
implications for language-in-education policy, teacher education, curriculum, pedagogy,
and assessment in multilingual classrooms