Sensory theories of developmental dyslexia: three challenges for research.

Recent years have seen the publication of a range of new theories suggesting that the basis of dyslexia might be sensory dysfunction. In this Opinion article, the evidence for and against several prominent sensory theories of dyslexia is closely scrutinized. Contrary to the causal claims being made, my analysis suggests that many proposed sensory deficits might result from the effects of reduced reading experience on the dyslexic brain. I therefore suggest that longitudinal studies of sensory processing, beginning in infancy, are required to successfully identify the neural basis of developmental dyslexia. Such studies could have a powerful impact on remediation.This is the accepted manuscript. The final version is available from NPG at http://www.nature.com/nrn/journal/v16/n1/abs/nrn3836.html

The Genetic Association Between ADHD Symptoms and Reading Difficulties: The Role of Inattentiveness and IQ

Previous studies have documented the primarily genetic aetiology for the stronger phenotypic covariance between reading disability and ADHD inattention symptoms, compared to hyperactivity-impulsivity symptoms. In this study, we examined to what extent this covariation could be attributed to “generalist genes” shared with general cognitive ability or to “specialist” genes which may specifically underlie processes linking inattention symptoms and reading difficulties. We used multivariate structural equation modeling on IQ, parent and teacher ADHD ratings and parent ratings on reading difficulties from a general population sample of 1312 twins aged 7.9–10.9 years. The covariance between reading difficulties and ADHD inattention symptoms was largely driven by genetic (45%) and child-specific environment (21%) factors not shared with IQ and hyperactivity-impulsivity; only 11% of the covariance was due to genetic effects common with IQ. Aetiological influences shared among all phenotypes explained 47% of the variance in reading difficulties. The current study, using a general population sample, extends previous findings by showing, first, that the shared genetic variability between reading difficulties and ADHD inattention symptoms is largely independent from genes contributing to general cognitive ability and, second, that child-specific environment factors, independent from IQ, also contribute to the covariation between reading difficulties and inattention symptoms

Traditional knowledge on medicinal plants used for the treatment of skin diseases in Bidar district, Karnataka

273-276A survey of medicinal plants of different rural and forest areas of Bidar district was conducted. It was found that the drug preparations of plant origin are commonly used by tribals, local inhabitants and folk practitioners for the treatment of skin diseases. About 26 plant species of 25 genera belonging to 16 families are described along with the method of drug preparation, mode of administration, probable dosage and duration of treatment. The aim of the study is not only to prescribe the remedies for skin diseases in human beings but also an endeavor to draw attention for the need of a detailed study on medicinal plants of the area, which could provide better and efficient remedies for many other dreadful diseases

Quantitative fMRI using hyperoxia calibration: reproducibility during a cognitive Stroop task.

Arterial spin labelling allows simultaneous measurement of both the blood-oxygenation-level-dependent (BOLD) and the cerebral blood flow (CBF) response to changes in neural activity. The addition of a hypercapnia or hyperoxia calibration allows additional quantification of changes in the cerebral metabolic rate of oxygen (CMRO(2)). In this study we test the reproducibility of measurements derived using the hyperoxia approach, during a cognitive Stroop task. A QUIPSSII sequence is used at 3 T to collect simultaneous CBF and BOLD signal during two 3 min periods of hyperoxia and an 8 min Stroop task. Hyperoxia was administered via an open system and end-tidal values were sampled via a nasal cannula; average end-tidal values of 60% were reached. This procedure is repeated to allow the reproducibility of the estimated parameters to be tested. The use of a cognitive Stroop task allows testing of the measurements in frontal and parietal regions as well as sensorimotor areas in which previous studies have been focussed. We find reduced reproducibility of the calculated parameters compared to the hypercapnia approach, thought to be attributable to lower absolute BOLD and CBF responses. In particular we do not find 'n' to have improved reproducibility compared to other parameters, as has been found in previous work using the hypercapnia approach. Across all brain areas we report a value of DeltaCMRO(2) of 12% and neurovascular coupling constant n of 2.5. Interestingly we find n to be higher in parietal and frontal areas in comparison to the primary motor cortex

Antimicrobial activity of α-(2-hydroxy-2-methylpropyl)-ω-(2-hydroxy-3-methylbut-2-en-1-yl) polymethylene from caesalpinia bonducella (L.) Flem

The compound, α-(2-hydroxy-2-methylpropyl)-ω-(2-hydroxy-3-methylbut-2-en-1-yl)polymethylene, isolated from ethyl acetate leaf extract of Caesalpinia bonducella (L.) Flem. was evaluated for antimicrobial activity against clinical isolates, Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella sp., Staphylococcus citrus, Staphylococcus aureus, Escherichia coli, Candida albicans and Rhodotorula sp. using agar diffusion method. The compound exerted inhibitory zone at all concentrations and revealed the concentration-dependent activity against all tested bacterial and yeast strains comparable to standards streptomycin sulphate and gentamycin for bacteria and fluconazole and griseofulvin for Candida albicans and Rhodotorula sp. The inhibition zones were wider and clear for C. albicans and Rhodotorula sp. (IZ >20 mm) and for Pseudomonas aeruginosa, P. vulgaris and E. coli zones were greater than standards tested, whereas, zones for Klebsiella sp. and S. aureus were similar to standards