The performance of solarscan : an automated dermoscopy image analysis instrument for the diagnosis of primary melanoma

Objective To describe the diagnostic performance of SolarScan (Polartechnics Ltd, Sydney, Australia), an automated instrument for the diagnosis of primary melanoma.

Design Images from a data set of 2430 lesions (382 were melanomas; median Breslow thickness, 0.36 mm) were divided into a training set and an independent test set at a ratio of approximately 2:1. A diagnostic algorithm (absolute diagnosis of melanoma vs benign lesion and estimated probability of melanoma) was developed and its performance described on the test set. High-quality clinical and dermoscopy images with a detailed patient history for 78 lesions (13 of which were melanomas) from the test set were given to various clinicians to compare their diagnostic accuracy with that of SolarScan.

Setting Seven specialist referral centers and 2 general practice skin cancer clinics from 3 continents. Comparison between clinician diagnosis and SolarScan diagnosis was by 3 dermoscopy experts, 4 dermatologists, 3 trainee dermatologists, and 3 general practitioners.

Patients Images of the melanocytic lesions were obtained from patients who required either excision or digital monitoring to exclude malignancy.

Main Outcome Measures Sensitivity, specificity, the area under the receiver operator characteristic curve, median probability for the diagnosis of melanoma, a direct comparison of SolarScan with diagnoses performed by humans, and interinstrument and intrainstrument reproducibility.

Results The melanocytic-only diagnostic model was highly reproducible in the test set and gave a sensitivity of 91% (95% confidence interval [CI], 86%-96%) and specificity of 68% (95% CI, 64%-72%) for melanoma. SolarScan had comparable or superior sensitivity and specificity (85% vs 65%) compared with those of experts (90% vs 59%), dermatologists (81% vs 60%), trainees (85% vs 36%; P =.06), and general practitioners (62% vs 63%). The intraclass correlation coefficient of intrainstrument repeatability was 0.86 (95% CI, 0.83-0.88), indicating an excellent repeatability. There was no significant interinstrument variation (P = .80).

Conclusions SolarScan is a robust diagnostic instrument for pigmented or partially pigmented melanocytic lesions of the skin. Preliminary data suggest that its performance is comparable or superior to that of a range of clinician groups. However, these findings should be confirmed in a formal clinical trial.

"The children must go out white"

This study looks at indigenous child removal in Western Australia as a case of genocide. The key figure in the process of child removal in Western Australia was the Chief Protector, A.O. Neville. The intention was complete biological absorption through forced child removal and controlled procreation of Aboriginal women.

Building awareness of mathematical modelling at teacher education: a case study in Indonesia

A growing interest to teach mathematics closely connected to its use in daily life has taken place in Indonesia for over a decade (Sembiring, Hadi, and Dolk 2008). This chapter  reports an exploratory case study of  the building of an awareness of mathematical modelling in teacher education in Indonesia. A modelling task, re-designing a parking lot (Ang 2009), was assigned to groups of pre-service secondary mathematics teachers. All groups undertook the stages of collecting data on a parking lot, identifying limitations in the current design of the parking lot, and proposing a new design based on their observations and analyses. The nature of the mathematical models elicited by pre-service teachers during various stages of completing the modelling task will be examined. Implications of this study suggest the need to encourage pre-service teachers to state the assumptions and real-world considerations and link them to the mathematical model in order to validate their models.

Request mitigating devices in Australian English and Iraqi Arabic : a comparative study

Speech acts realization in everyday interaction is seen as an important field to explore the impact of linguistic and cultural variations on cross-cultural communication and second language acquisition. The reported study investigates the use of request mitigating devices in Australian English and Iraqi Arabic. It explores the internal and external devices that speakers of the two languages use to mitigate the imposition force of requests and the impact of the linguistic and cultural parameters on this use. Request samples were collected from 14 native speakers of Australian English and 14 native speakers of Iraqi Arabic by means of eight role-play interviews. The mitigating devices were identified and classified according to a modified categorization scheme based on Blum-Kulka et al. (1989). Additional categories of mitigating devices were added to this scheme to meet the requirements of data analysis. These include consultative device (Blum-Kulka & Olshtain, 1984), questions (Trosborg, 1995), apology (Economidou-Kogetsidis, 2008), alerter (Schauer, 2007), closing (Al-Ali & Alawneh, 2010), and new categories: wish/hope statement and verbal incentive. The results showed that internal mitigating devices were more frequent in Australian English requests than in Iraqi Arabic requests, while external mitigating devices were equally pervasive in both groups. The two groups also used different semantic formulae of some mitigating devices in specific situations. The pervasive occurrence of external mitigators in both groups‟ requests is discussed in terms of volubility as a politeness strategy. It is suggested that the divergence between the two groups in their utilization of request mitigations is related to linguistic and cultural variations between the Australian and Iraqi languages and cultures.