Development of attentional processes in ADHD and normal children

Attention Deficit Hyperactivity Disorder (ADHD) is a developmental disorder. Typical development of attentional processes is rapid during early childhood. ADHD results in impairment in response inhibition, error monitoring, attentional disengagement, executive attention, and delay aversion and may effect the ongoing development of these processes during childhood. We examined the development of attentional processes in children with ADHD and normal children. Two hundred forty children (120 in each group) in the age range of 6–9 years participated in the study. Four tasks: Stop-Signal, attentional disengagement, attention network, and choice delay task were administered. Stop signal reaction time, switch costs, conflict effect, and percentage choice of short delay reward was higher in ADHD group compared to normal group. Post error of slowing was less in ADHD children. Endogenous orienting effect was more in normal children compared to ADHD children. Different developmental trajectories were observed for control functions in normal children. Major development in response inhibition occurred in 7–8 years, error monitoring in 6–9 years, and attentional disengagement in 7–9 years. Late development in alerting network was observed in normal children at age 9 years. No developmental changes occurred on these control functions in ADHD children aged 6–9 years. Age related changes were observed on delay aversion between 6 and 9 years in normal children, while it changed between 6 and 7 years in ADHD children. Performance was not changed on orienting and conflict attentional networks in both the children except conflict effect reduced between 7 and 9 years in ADHD children under double cue condition. Conflict network was interacted with the alerting and orienting network in normal children; specifically conflict network interacted with the orienting network in younger children (age 6 years) and with alerting network in older children (age 9 years). In ADHD group interaction between alerting and conflict network was observed only in the double cue condition. Together these results indicated that the deficits in control processes accumulate with age in ADHD children Present study favors the conceptual view of ADHD as a stable deficit in cognitive control functions, which are implicated in the pathology of ADHD. These results have theoretical implication for the theories of executive control and ADHD

Interpretative Bias: Indicators of Cognitive Vulnerability to Depression

Objectives: The study aimed at testing the existence of interpretative bias in remitted depressives as compared to unipolar depressives and never-depressed individuals. Method: Cognitive Bias Questionnaire was administered on 10 individuals each with unipolar depression, remitted depression, and never-depressed participants. Participants were presented with vague and ambiguous vignettes of potentially problematic situation that individuals often encounter their daily lives. Each vignette is followed by four questions with four response options reflecting a depressed-distorted, depressed-nondistorted, nondepressed-distorted, or nondepressed- nondistorted option. Participants choose the response option that best represents how they would respond to the situation if it actually happened to them. Results: Unipolar depressives interpret their condition as high on depressive mood symptoms as well as distorted thoughts whereas remitted depressives interpret their condition as high on distorted thoughts alone. Conclusions: It may suggest that despite of reduction in level of symptomatic severity of depression, cognitive errors are still maintained during remission, can increase one’s vulnerability for relapse. It implies that management of depression should focus on reducing cognitive vulnerability to depression, rather than only targeting a reduction in the symptoms

Development of Task Switching and Post-Error Slowing in Children

Background: Executive control processes such as task switching and error processing have been shown to change with age. The present study explored from a developmental perspective whether shared or different mechanisms underlie these processes. Methods: The sample included 180 children (30 in each of the six age groups from 6-11 years) who were required to perform two different tasks: identification of a digit, or counting the number of digits. We computed switch costs as a function of response-repetition, stimulus-response (S-R) compatibility, and post-error-slowing. We also analyzed reaction time distributions. Results and discussion: The results showed a switch cost in the response-repetition condition, with a reduction in switch cost between 7 to 8 and 9 to 10 years of age, and an S-R compatibility effect in 6 to 9 years old children. Reaction time (RT) distributions showed that the decrement in the switch cost is due to the overall decrease in RTs in fast (5th percentile) trials in 9 to 11 year olds, and slow (95th percentile) trials in 7 to 8 and 9 to 11 years old children, in both the task switch and non-switch trials. A major reduction in RT was found between 9 to 11 years in both the response type and S-R compatibility type conditions. RT distributions for post-error trials revealed that the large decrement seen in 7 to 8 and 9 to 10 years old children is primarily due to the sudden decrease in RTs in the fast and slow trials respectively. The developmental pattern of error processing was similar to one component of task switching (switch cost of the response-repetition condition), indicating that inhibition could be a common mechanism underlying both the processes. However, the failure to maintain task set was found only with task switching. Conclusion: The development of task switching and error processing is not gradual. The developmental pattern of error processing is similar to that of the switch cost of the responserepetition condition in task switching, indicating that inhibition could be a common mechanism underlying both processes. The present results have implications for theories of executive control

Relationship between Tibial conformation, cage size and advancement achieved in TTA procedure

Previous studies have suggested that there is a theoretical discrepancy between the cage size and the resultant tibial tuberosity advancement, with the cage size consistently providing less tibial tuberosity advancement than predicted. The purpose of this study was to test and quantify this in clinical cases. The hypothesis was that the advancement of the tibial tuberosity as measured by the widening of the proximal tibia at the tibial tuberosity level after a standard TTA, will be less than the cage sized used, with no particular cage size providing a relative smaller or higher under-advancement, and that the conformation of the proximal tibia will have an influence on the amount of advancement achieved

Targeting low-cost type-II heterostructures: Synthesis, structure and photoreactivity

One design strategy by which to iterate the photocatalytic efficiency of semiconducting nanomaterials for harvesting solar energy involves the synthesis of type-II heterostructured materials. In this article, a straightforward, facile and environmentally benign route to heterostructures in which SnO₂ nanospheres are capped by PbS nanocubes is reported. It offers to address current limitations to photocatalytic efficiency brought about by electron-hole recombination and narrow photoresponsive ranges in many existing systems. PbS nanocubes are grown in the presence of preformed SnO₂ nanospheres by functionalizing the surface of the latter using cetyltrimethylammonium bromide (CTAB). Heterostructure formation is confirmed by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) surface area analysis, and transmission electron microscopy (TEM) analysis. Rietveld refinement has been exploited to simultaneously elucidate the atomic and microstructures of these materials, allowing the quantitative determination of particle structure and stability. The combination of narrow band-gap semiconductor (PbS) and wide band-gap semiconductor (SnO₂) endows the heterostructured nanomaterial with potential as a photocatalyst and, in the degradation of Rhodamine B (RhB) dye under solar simulation, it showed superior photocatalytic activity to that of its separate SnO₂ and PbS components. A strong type-II interaction is demonstrated by the heterostructure and a charge separation mechanism has been utilized to clarify this behaviour.A. K. acknowledges support from the Royal Society's Newton International Fellowship scheme (NF130808). B. R. K. thanks the UK EPSRC for financial support (EP/J500380/1)

Single lesion multibacillary leprosy, a treatment enigma: a case report

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

The use of phylogeny to interpret cross-cultural patterns in plant use and guide medicinal plant discovery: an example from Pterocarpus (Leguminosae)

The study of traditional knowledge of medicinal plants has led to discoveries that have helped combat diseases and improve healthcare. However, the development of quantitative measures that can assist our quest for new medicinal plants has not greatly advanced in recent years. Phylogenetic tools have entered many scientific fields in the last two decades to provide explanatory power, but have been overlooked in ethnomedicinal studies. Several studies show that medicinal properties are not randomly distributed in plant phylogenies, suggesting that phylogeny shapes ethnobotanical use. Nevertheless, empirical studies that explicitly combine ethnobotanical and phylogenetic information are scarce.In this study, we borrowed tools from community ecology phylogenetics to quantify significance of phylogenetic signal in medicinal properties in plants and identify nodes on phylogenies with high bioscreening potential. To do this, we produced an ethnomedicinal review from extensive literature research and a multi-locus phylogenetic hypothesis for the pantropical genus Pterocarpus (Leguminosae: Papilionoideae). We demonstrate that species used to treat a certain conditions, such as malaria, are significantly phylogenetically clumped and we highlight nodes in the phylogeny that are significantly overabundant in species used to treat certain conditions. These cross-cultural patterns in ethnomedicinal usage in Pterocarpus are interpreted in the light of phylogenetic relationships.This study provides techniques that enable the application of phylogenies in bioscreening, but also sheds light on the processes that shape cross-cultural ethnomedicinal patterns. This community phylogenetic approach demonstrates that similar ethnobotanical uses can arise in parallel in different areas where related plants are available. With a vast amount of ethnomedicinal and phylogenetic information available, we predict that this field, after further refinement of the techniques, will expand into similar research areas, such as pest management or the search for bioactive plant-based compounds

Infant growth disparity in the Khanh Hoa province in Vietnam: a follow-up study

<p>Abstract</p> <p>Background</p> <p>Surveys in Vietnam have indicated that wasting and stunting have been prevalent among children, but the country is undergoing rapid socio-economic changes and little has been known about the relative situation in the different areas of the country. In 2006, the WHO introduced new growth standards applicable to all infant and child populations, which facilitates for improved assessments of the prevalence of growth impairment, independent of time, place and ethnicity. The aim of our study was to assess the growth of singleton infants delivered at term in three main birth clinics in the Khanh Hoa province in Vietnam by using the new WHO standards as reference, and the association between growth and some maternal, birth and health factors.</p> <p>Methods</p> <p>A cohort of 237 singleton infants born in the period May-July 2005 in three main delivery clinics in the Khanh Hoa province were observed prospectively. Their anthropometrical measures a year later were compared to the WHO sex-specific growth standards for weight-for-age, length-for-age, weight-for-length, and BMI-for-age. These measures were analysed as dependent outcomes using multiple linear regression models including the following independent factors: urban vs. rural birth, 1-minute Apgar score, weight and length at birth, duration of lactation, ever had diarrhoea, dengue fever, pneumonia or dysentery, and maternal age, height, gestational duration and parity.</p> <p>Results</p> <p>Compared to the standard distributions, 79% were below the median for weight-for-length; 18.0% were within the 5^thpercentile for length-for-age, 9.6% for weight-for-age, 20.3% for weight-for-length, and 19.8% for BMI. A lower length- and weight-for-age were statistically associated with being born rurally.</p> <p>Conclusions</p> <p>In this delivery-clinic based sample of children in the Khanh Hoa province in Vietnam, the proportions within the WHO-standard 5^thpercentiles for length-for-age, weight-for-length and BMI in late infancy were 3-4 times higher than expected, which indicate that deficient growth is prevalent. The infants born in a rural area had a lower weight- and length-for-age than their urban counterparts, independent of diarrhoea.</p

A community-based cluster randomised controlled trial to evaluate the effectiveness of different bundles of nutrition-specific interventions in improving mean length-for-age z score among children at 24 months of age in rural Bangladesh: study protocol

PRIFPRI3; CRP4; ISIPHND; A4NHCGIAR Research Program on Agriculture for Nutrition and Health (A4NH