20 research outputs found

    Reduced relative volume in motor and attention regions in developmental coordination disorder: a voxel-based morphometry study.

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    Background and Objectives: Developmental coordination disorder (DCD) is a prevalent childhood movement disorder, impacting the ability to perform movement skills at an age appropriate level. Although differences in grey matter (GM) volumes have been found in related developmental disorders, no such evidence has been linked with DCD to date. This cross-sectional study assessed structural brain differences in children with and without DCD. Methods: High-resolution structural images were acquired from 44 children aged 7.8–12 years, including 22 children with DCD (≀16th percentile on MABC-2; no ADHD/ASD), and 22 typically developing controls (≄20th percentile on MABC-2). Structural voxel-based morphology analysis was performed to determine group differences in focal GM volumes. Results: Children with DCD were found to have significant, large, right lateralised reductions in grey matter volume in the medial and middle frontal, and superior frontal gyri compared to controls. The addition of motor proficiency as a covariate explained the between-group GM volume differences, suggesting that GM volumes in motor regions are reflective of the level of motor proficiency. A positive correlation between motor proficiency and relative GM volume was also identified in the left posterior cingulate and precuneus. Conclusions: GM volume reductions in premotor frontal regions may underlie the motor difficulties characteristic of DCD. It is possible that intervention approaches targeting motor planning, attention, and executive functioning processes associated with the regions of reduced GM volume may result in functional improvements in children with DCD

    Mapping interactions with the chaperone network reveals factors that protect against tau aggregation.

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    A network of molecular chaperones is known to bind proteins ('clients') and balance their folding, function and turnover. However, it is often unclear which chaperones are critical for selective recognition of individual clients. It is also not clear why these key chaperones might fail in protein-aggregation diseases. Here, we utilized human microtubule-associated protein tau (MAPT or tau) as a model client to survey interactions between ~30 purified chaperones and ~20 disease-associated tau variants (~600 combinations). From this large-scale analysis, we identified human DnaJA2 as an unexpected, but potent, inhibitor of tau aggregation. DnaJA2 levels were correlated with tau pathology in human brains, supporting the idea that it is an important regulator of tau homeostasis. Of note, we found that some disease-associated tau variants were relatively immune to interactions with chaperones, suggesting a model in which avoiding physical recognition by chaperone networks may contribute to disease

    Cortical functioning in children with developmental coordination disorder:a motor overflow study

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    This study examined brain activation in children with developmental coordination disorder (DCD) to reveal areas that may contribute to poor movement execution and/or abundant motor overflow. Using functional magnetic resonance imaging, 13 boys with DCD (mean age = 9.6 years ±0.8) and 13 typically developing controls (mean age = 9.3 years ±0.6) were scanned performing two tasks (finger sequencing and hand clenching) with their dominant hand, while a four-finger motion sensor recorded contralateral motor overflow on their non-dominant hand. Despite displaying increased motor overflow on both functional tasks during scanning, there were no obvious activation deficits in the DCD group to explain the abundant motor overflow seen. However, children with DCD were found to display decreased activation in the left superior frontal gyrus on the finger-sequencing task, an area which plays an integral role in executive and spatially oriented processing. Decreased activation was also seen in the left inferior frontal gyrus, an area typically active during the observation and imitation of hand movements. Finally, increased activation in the right postcentral gyrus was seen in children with DCD, which may reflect increased reliance on somatosensory information during the execution of complex fine motor tasks

    Clinical utilization of genomics data produced by the international Pseudomonas aeruginosa consortium

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    The International Pseudomonas aeruginosa Consortium is sequencing over 1000 genomes and building an analysis pipeline for the study of Pseudomonas genome evolution, antibiotic resistance and virulence genes. Metadata, including genomic and phenotypic data for each isolate of the collection, are available through the International Pseudomonas Consortium Database (http://ipcd.ibis.ulaval.ca/). Here, we present our strategy and the results that emerged from the analysis of the first 389 genomes. With as yet unmatched resolution, our results confirm that P. aeruginosa strains can be divided into three major groups that are further divided into subgroups, some not previously reported in the literature. We also provide the first snapshot of P. aeruginosa strain diversity with respect to antibiotic resistance. Our approach will allow us to draw potential links between environmental strains and those implicated in human and animal infections, understand how patients become infected and how the infection evolves over time as well as identify prognostic markers for better evidence-based decisions on patient care

    Argumentation Vee Diagrams (AVDs) enrich online discussions

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    With online Argumentation Vee Diagrams (AVDs), students compose arguments on both sides of a controversial issue and then develop an integrated conclusion. In this study, students used AVDs prior to composing discussion notes, and - at the end of each discussion - jointly created a group AVD. AVDs significantly enhanced the number of arguments/counterarguments and compromises in students\u27 discussion notes, and promoted opinion change. However, for AVDs to be effective, students also needed instruction on evaluating argument strength

    Putting the pieces together: Online argumentation vee diagrams enhance thinking during discussions

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    We examine the effect of online Argumentation Vee Diagrams (AVDs) on the quality of students\u27 argumentation during asynchronous, online discussions. With AVDs, students develop arguments on both sides of a controversial issue and then develop an integrated, overall final conclusion. In this study, students used AVDs individually before composing discussion notes, and then-at the end of the discussion-jointly created a group AVD using Wiki technology. Compared to a control group, the experimental intervention was found to significantly enhance the integration of arguments and counterarguments (specifically, compromises) and fostered opinion change. For AVDs to be effective, however, it was found to be necessary to include specific scaffolds on how to evaluate argument strength and/or to provide practice and feedback in using the AVDs. © 2007 International Society of the Learning Sciences, Inc.; Springer Science+ Business Media, LLC

    Comparative transcriptomics analyses reveal the conservation of an ancestral infectious strategy in two bacteriophage genera.

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    International audienceAlthough the evolution of tailed bacteriophages has increasingly been better understood through comparisons of their DNA sequences, the functional consequences of this evolution on phage infectious strategies have remained unresolved. In this study, we comprehensively compared the transcriptional strategies of two related myoviruses, PAK_P3 and PAK_P4, infecting the same Pseudomonas aeruginosa host strain. Outside of the conservation of their structural clusters, their highly syntenic genomes display only limited DNA similarity. Despite this apparent divergence, we found that both viruses follow a similar infection scheme, relying on a temporal regulation of their gene expression, likely involving the use of antisense transcripts, as well as a rapid degradation of 90% of the host non-ribosomal mRNA, as previously reported for PAK_P3. However, the kinetics of the mRNA degradation is remarkably faster during PAK_P4 infection. Moreover, we found that each virus has evolved specific adaptations, as exemplified by the distinct patterns of their core genes expression as well as the specific manipulation of the expression of iron-related host genes by PAK_P4. This study enhances our understanding of the evolutionary process of virulent phages, which relies on adjusting globally conserved ancestral infection mechanisms.The ISME Journal advance online publication, 12 May 2017; doi:10.1038/ismej.2017.63
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