Noroviruses evolve by antigenic drift and recombination, which occurs most frequently at the junction between the non-structural and structural protein coding genomic regions. In 2015, a novel GII.P16-GII.4 Sydney recombinant strain emerged, replacing the predominance of GII.Pe-GII.4 Sydney among US outbreaks. Distinct from GII.P16 polymerases detected since 2010, this novel GII.P16 was subsequently detected among GII.1, GII.2, GII.3, GII.10 and GII.12 viruses, prompting an investigation on the unique characteristics of these viruses. Norovirus positive samples (n = 1807) were dual-typed, of which a subset (n = 124) was sequenced to yield near-complete genomes. CaliciNet and National Outbreak Reporting System (NORS) records were matched to link outbreak characteristics and case outcomes to molecular data and GenBank was mined for contextualization. Recombination with the novel GII.P16 polymerase extended GII.4 Sydney predominance and increased the number of GII.2 outbreaks in the US. Introduction of the novel GII.P16 noroviruses occurred without unique amino acid changes in VP1, more severe case outcomes, or differences in affected population. However, unique changes were found among NS1/2, NS4 and VP2 proteins, which have immune antagonistic functions, and the RdRp. Multiple polymerase-capsid combinations were detected among GII viruses including 11 involving GII.P16. Molecular surveillance of protein sequences from norovirus genomes can inform the functional importance of amino acid changes in emerging recombinant viruses and aid in vaccine and antiviral formulation.
This phenomenological research study replicates R. Segal's (1998) study of 17 Canadian families. The authors interview 17 american families participating in the national support group Children and adults with attention Deficit Disorder, focusing on the challenges they face in rearing children diagnosed with aDHD. Three particular themes emerge. First, the parents appear to be attuned to their children's needs and report being proactive in making adaptations and interventions when needed to accomplish family objectives. Second, the results are generally congruent with those reported by Segal. In both cases, mornings and afternoons are vulnerable times for the families. Segal found mornings most difficult, however, whereas families in this study relate homework periods in the afternoons to be most challenging. Third, parental strategies are salient for successfully rearing children with aDHD. The families emphasize the constructs of routine and structure as being paramount to navigating daily life successfully.
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