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Coordination is often observed as body parts moving together. However, when producing force with multiple fingers, the optimal coordination is not to produce similar forces with each finger, but rather for each finger to correct mistakes of other fingers. In this study, we aim to determine whether and how this skill develops in children aged 4-12 years. We measured this sort of coordination using the uncontrolled manifold hypothesis (UCM). We recorded finger forces produced by 60 typically developing children aged between 4 and 12 years in a finger-pressing task. The children controlled the height of an object on a screen by the total amount of force they produced on force sensors. We found that the synergy index, a measure of the relationship between 'good' and 'bad' variance, increased linearly as a function of age. This improvement was achieved by a selective reduction in 'bad' variance rather than an increase in 'good' variance. We did not observe differences between males and females, and the synergy index was not able to predict outcomes of upper limb behavioral tests after controlling for age. As children develop between the ages of 4 and 12 years, their ability to produce negative covariation between their finger forces improves, likely related to their improved ability to perform dexterous tasks. [ABSTRACT FROM AUTHOR]

A journal's impact factor (IF) may be boosted by increasing self-citations. We aimed to determine the self-citation rate (SCR) of pediatric journals registered in the Journal Citations Report (JCR), to evaluate the impact of SCR upon the IF and to determine the effect of the SCR of a journal on its IF. We found 117 journals categorized as pediatric journals by the JCR (as of 2013). The median and range of SCR, IF and corrected IF (IF without self-citations) were 9 % (0-30 %), 1.54 (0-6.35) and 1.37 (0-5.87) respectively. No differences were found between general and subspecialty journals in terms of SCR, IF or corrected IF. Spearman's ranked correlation showed that IF was significantly and inversely correlated with SCR ( r = −0.28, P = 0.002; R = 0.08). There was a significant difference between IF and corrected IF among all journals (1.74 ± 1.04 vs 1.59 ± 0.98, P < 0.001). Self-citation is relatively rare in pediatric journals. Importantly and unlike other fields of medicine, self-citation was found to be more prevalent in journals with a lower IF and also with lower corrected IF. [ABSTRACT FROM AUTHOR]

Permanent congenital hypothyroidism is the most prevalent inborn endocrine disorder, and principally due to developmental defects leading to absent, ectopic or hypoplastic thyroid gland. Although commonly regarded as sporadic disease, nonsyndromic thyroid hypoplasia has, in rare cases, been attributed to inherited defects in PAX8 and the TSHR gene. The shared clinical picture caused by these defects is a variable degree of thyrotropin resistance (RTSH [MIM 275200]), accompanied in its severe form by thyroid gland hypoplasia. We recently identified six extended kindreds with autosomal dominant RTSH, only one of which was linked to a mutation in the PAX8 candidate gene. Genome wide scans conducted in two of the remaining five families revealed independently significant linkage to chromosome 15q25.3–26.1, with maximum multipoint LOD scores of 8.51 and 4.31. Linkage to this novel locus was replicated ( P<0.01) in each of the three remaining kindreds. Fine mapping of key recombinants in the largest family localized the causative gene within a 3 cM/2.9 Mb interval. Thus, we report the first locus for congenital nongoitrous hypothyroidism identified by a genome wide screening approach. [ABSTRACT FROM AUTHOR]