Cdata intensive ASE STUDIES


Reading the future IDL


is known about it, but not much about how it works and nothing about how it happens. Dealing with it is a process of probabilistic prediction on the basis of accumulated past experience.


T


he word ‘dyslexia’ describes an observed set of manifestations (a diffi culty with words) rather than an understood set of causes and effects. A considerable amount


One of the things which is known is that the


extent to which ability to read will progress varies from one dyslexic child to another. It is useful to make estimates of how this progress might be expected to proceed in a particular individual, but existing methods of doing this, based on behavioural indicators, are not always as reliable as professionals in the fi eld might wish. Using analytic software written in Interactive


Data Language (IDL) to implement the Reproducible Objective Quantifi cation Scheme (a partially automated Region of Interest method), Fumiko Hoeft and an international, multidisciplinary team set out to investigate whether a neuroprognostic approach might have more success. Over a two and a half year longitudinal study of 45 children (25 of them dyslexic, 20 not, with diagnoses not revealed to investigators), functional magnetic resonance and diffusion tensor images (fMRI and DTI) during phonological reading tasks were analysed in relation to improvements in reading skills. Multivariate pattern analysis of specifi c brain


measures showed a 72 per cent success rate in predicting whether a child would or would not show reading skills improvement over the life of the study. For whole brain activation patterns, that rose to 90 per cent. In both cases, success rate was greater than for parallel behavioural predictions.


Multivariate pattern classifi cation of reading gains in dyslexia. (A) Classifi cation accuracy. (B) Association between distance from hyperplane for the whole-brain fMRI pattern classifi er and gains in reading ability. (C) Brain activation patterns that discriminate between children with dyslexia who gained in reading ability versus those who did not. (D) Overlap (yellow) between results from fMRI univariate regression analysis (green) and multivariate analysis (red) in the right IFG activation


Committing fl uicide OriginPro


I


nfl uenza, in all its forms, is estimated by the World Health Organisation to cost somewhere in the region of 400 human lives per year, degrade the health of around half a billion, and


make a signifi cant impact on global economics. The discovery by scientists at MIT that surfaces coated with hydrophobic polycations (chemical structures with multisite positive charges) can not only kill bacteria and fungi but also act viricidally to disinfect water-borne infl uenza populations was, therefore, of great interest. The effect is derived from irreversible adhesion of (negatively charged) viruses to the coating, resulting in breakdown and release of viral RNA into solution. In follow-up work, the team examined several aspects of the mechanisms involved, including


Relative quantities of infl uenza A viral RNA in solution prior to assay (white bars), after incubation with bare polyethylene slides (hatch-marked bars), and after incubation with N,N-dodecyl,methyl-PEI- coated polyethylene slides (cross-hatched bars)


investigation of dodecyltrimethylammonium bromide’s (DTAB) effectiveness in replicating the effect. Using OriginPro dose response fi tted curve replicates, 50 per cent inhibitory and toxicity concentrations (IC50 and TC50) were calculated from experimental results as MDCK cells were exposed to progressively dilute concentrations of DTAB.


Sources Hsu, B.B., et al., ‘Mechanism of inactivation of infl uenza viruses by immobilized hydrophobic polycations.’ Proceedings of the National Academy of Sciences, 2011. 108(1): pp.61–66.


OriginPro: www.originlab.com/index. aspx?go=Products/OriginPro


Statistics special 25


Sources Hoeft, F., et al., ‘Neural systems predicting long-term outcome in dyslexia.’ Proceedings of the National Academy of Sciences, USA, 2011. 108(1): pp.361-366.


IDL: www.ittvis.com/language/en-us/ productsservices/idl.aspx


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