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The Developing Human Connectome Project is an Open Science project that provides the first large sample of neonatal functional MRI data with high temporal and spatial resolution. These data enable mapping of intrinsic functional connectivity between spatially distributed brain regions under normal and adverse perinatal circumstances, offering a framework to study the ontogeny of large-scale brain organization in humans. Here, we characterize in unprecedented detail the maturation and integrity of resting state networks (RSNs) at term-equivalent age in 337 infants (including 65 born preterm). First, we applied group independent component analysis to define 11 RSNs in term-born infants scanned at 43.5-44.5 weeks postmenstrual age (PMA). Adult-like topography was observed in RSNs encompassing primary sensorimotor, visual and auditory cortices. Among six higher-order, association RSNs, analogues of the adult networks for language and ocular control were identified, but a complete default mode network precursor was not. Next, we regressed the subject-level datasets from an independent cohort of infants scanned at 37-43.5 weeks PMA against the group-level RSNs to test for the effects of age, sex and preterm birth. Brain mapping in term-born infants revealed areas of positive association with age across four of six association RSNs, indicating active maturation in functional connectivity from 37 to 43.5 weeks PMA. Female infants showed increased connectivity in inferotemporal regions of the visual association network. Preterm birth was associated with striking impairments of functional connectivity across all RSNs in a dose-dependent manner; conversely, connectivity of the superior parietal lobules within the lateral motor network was abnormally increased in preterm infants, suggesting a possible mechanism for specific difficulties such as developmental coordination disorder, which occur frequently in preterm children. Overall, we found a robust, modular, symmetrical functional brain organization at normal term age. A complete set of adult-equivalent primary RSNs is already instated, alongside emerging connectivity in immature association RSNs, consistent with a primary-to-higher order ontogenetic sequence of brain development. The early developmental disruption imposed by preterm birth is associated with extensive alterations in functional connectivity., (© The Author(s) (2021). Published by Oxford University Press on behalf of the Guarantors of Brain.)

Interruptions to neurodevelopment during the perinatal period may have long-lasting consequences. However, to be able to investigate deviations in the foundation of proper connectivity and functional circuits, we need a measure of how this architecture evolves in the typically developing brain. To this end, in a cohort of 241 term-born infants, we used magnetic resonance imaging to estimate cortical profiles based on morphometry and microstructure over the perinatal period (37-44 weeks postmenstrual age, PMA). Using the covariance of these profiles as a measure of inter-areal network similarity (morphometric similarity networks; MSN), we clustered these networks into distinct modules. The resulting modules were consistent and symmetric, and corresponded to known functional distinctions, including sensory-motor, limbic, and association regions, and were spatially mapped onto known cytoarchitectonic tissue classes. Posterior regions became more morphometrically similar with increasing age, while peri-cingulate and medial temporal regions became more dissimilar. Network strength was associated with age: Within-network similarity increased over age suggesting emerging network distinction. These changes in cortical network architecture over an 8-week period are consistent with, and likely underpin, the highly dynamic processes occurring during this critical period. The resulting cortical profiles might provide normative reference to investigate atypical early brain development., (© The Author(s) 2020. Published by Oxford University Press.)

The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb) is the smallest chromosome in Drosophila melanogaster , but it is substantially larger (>18.7 Mb) in D. ananassae To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4-Mb region of the D. ananassae F element, and a 1.7-Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) are major contributors to this expansion (78.6%), while Wolbachia sequences integrated into the D. ananassae genome are minor contributors (0.02%). Both D. melanogaster and D. ananassae F-element genes exhibit distinct characteristics compared to D-element genes ( e.g. , larger coding spans, larger introns, more coding exons, and lower codon bias), but these differences are exaggerated in D. ananassae Compared to D. melanogaster , the codon bias observed in D. ananassae F-element genes can primarily be attributed to mutational biases instead of selection. The 5' ends of F-element genes in both species are enriched in dimethylation of lysine 4 on histone 3 (H3K4me2), while the coding spans are enriched in H3K9me2. Despite differences in repeat density and gene characteristics, D. ananassae F-element genes show a similar range of expression levels compared to genes in euchromatic domains. This study improves our understanding of how transposons can affect genome size and how genes can function within highly repetitive domains., (Copyright © 2017 Leung et al.)

Objectives: To examine the delivery of postgraduate training in the emergency medicine setting and its impact on postgraduate doctor (Foundation Year 2) performance and competence., Methods: A national study in four emergency departments (EDs) in England between 2009 and 2010 was undertaken. Semistructured interviews with ED training leads (TLs) and focus groups with Foundation Year 2 (F2) doctors were carried out in each ED. Interviews and focus group data were analysed to compare the perspectives of F2 doctors and TLs on the delivery of training and performance and confidence of F2 doctors., Results: Interviews were carried out with eight TLs and focus groups with 30 F2s. F2 doctors and EDTLs agreed that ED was a valuable environment for F2 doctors to develop their competence, with exposure to a broad range of patients and the opportunity to make decisions about clinical care. Diverging views existed around competence and performance of F2s. F2 doctors had anxieties about decision-making (particularly discharging patients) and required regular feedback to feel confident in their care. TLs recognised a need for more supervision and support for F2 doctors but this was challenging in a busy, performance-led service., Conclusions: Emergency medicine placements were important in the development of confident and competent F2 doctors, particularly in the context of less clinical exposure in other specialty placements. However, there are competing tensions between elements of postgraduate learning and service delivery within emergency medicine that require addressing to enable trainees to optimally develop knowledge and skills in this environment., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

The tensile bond strength was evaluated for three different types of stainless steel orthodontic bracket/base combinations (both cast and machined integral bases, and a foil-mesh base). The cast base gave a significantly higher initial bond strength than the other two brackets. Following recycling by either chemical or thermal methods, all the bases demonstrated a significant reduction in bond strength. However, thermal recycling produced an unacceptably large reduction in the bond strength of the cast base and this method of reconditioning should be avoided with these brackets. Recycling the brackets an additional four times was found to result in a further reduction in bond strength, but this was not statistically significant. Clinically used brackets demonstrated a slightly lower, though not statistically significant, bond strength compared to unused brackets following one recycling with either the chemical or thermal method.

This paper deals with dental centre line discrepancies and the treatment mechanics for their correction when using an edgewise appliance.