BackgroundAlthough polychaetes are one of the dominant taxa in marine communities, their distributions and taxonomic diversity are poorly understood. Recent studies have shown that many species thought to have broad distributions are actually a complex of allied species. In Canada, 12% of polychaete species are thought to occur in Atlantic, Arctic, and Pacific Oceans, but the extent of gene flow among their populations has not been tested.Methodology/Principal FindingsSequence variation in a segment of the mitochondrial cytochrome c oxidase I (COI) gene was employed to compare morphological versus molecular diversity estimates, to examine gene flow among populations of widespread species, and to explore connectivity patterns among Canada's three oceans. Analysis of 1876 specimens, representing 333 provisional species, revealed 40 times more sequence divergence between than within species (16.5% versus 0.38%). Genetic data suggest that one quarter of previously recognized species actually include two or more divergent lineages, indicating that richness in this region is currently underestimated. Few species with a tri-oceanic distribution showed genetic cohesion. Instead, large genetic breaks occur between Pacific and Atlantic-Arctic lineages, suggesting their long-term separation. High connectivity among Arctic and Atlantic regions and low connectivity with the Pacific further supports the conclusion that Canadian polychaetes are partitioned into two distinct faunas.Conclusions/SignificanceResults of this study confirm that COI sequences are an effective tool for species identification in polychaetes, and suggest that DNA barcoding will aid the recognition of species overlooked by the current taxonomic system. The consistent geographic structuring within presumed widespread species suggests that historical range fragmentation during the Pleistocene ultimately increased Canadian polychaete diversity and that the coastal British Columbia fauna played a minor role in Arctic recolonization following deglaciation. This study highlights the value of DNA barcoding for providing rapid insights into species distributions and biogeographic patterns in understudied groups.

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In the largest sample studied to date, we measured cognitive functioning in children and adolescents with pediatric multiple sclerosis (n =187) as well as those with clinically isolated syndrome (n =44). Participants were consecutively enrolled from six United States PediatricMultiple Sclerosis Centers of Excellence. Participants had amean of 14.8 ± 2.6 years of age and an average disease duration of 1.9 ± 2.2 years. A total of 65 (35%) children with multiple sclerosis and 8 (18%) with clinically isolated syndrome met criteria for cognitive impairment. The most frequent areas involved were fine motor coordination (54%), visuomotor integration (50%), and speeded information processing (35%). A diagnosis of multiple sclerosis (odds ratio = 3.60, confidence interval = 1.07, 12.36, P = .04) and overall neurologic disability (odds ratio = 1.47, confidence interval = 1.10, 2.10, P = .03) were the only independent predictors of cognitive impairment. Cognitive impairment may occur early in these patients, and prompt recognition is critical for their care.

Objective To test the efficacy of Counselor-Assisted Problem Solving (CAPS) versus an internet resources comparison (IRC) condition in reducing behavior problems in adolescents following traumatic brain injury (TBI). Design Randomized clinical trial with interviewers naïve to treatment condition. Setting Three large tertiary children's hospitals and two general hospitals with pediatric commitment. Participants 132 children ages 12-17 years hospitalized during the previous 6 months for moderate to severe TBI. Interventions Participants in CAPS (n = 65) completed 8-12 online modules providing training in problem solving, communication skills, and self-regulation and subsequent synchronous videoconferences with a therapist. Participants in the IRC group (n = 67) received links to internet resources about pediatric TBI. Main Outcome Measures Child Behavior Checklist (CBCL) administered before and after completion of treatment (i.e., approximately six months after treatment initiation). Results Post hoc analysis of covariance (ANCOVA), controlling for pre-treatment scores, was used to examine group differences in behavior problems in the entire sample and among older (n=59) and younger adolescents (n=53). Among older but not younger adolescents, CAPS resulted in greater improvements on multiple dimensions of externalizing behavior problems than did IRC. Conclusion Online problem-solving therapy may be effective in reducing behavior problems in older adolescent survivors of moderate-severe TBI.