Observational learning in children with Down syndrome and developmental delays: the effect of presentation speed in videotaped modelling.

Children with severe developmental delays (three with Down syndrome and three with autism as the primary diagnosis) observed a videotaped model performing two basic dressing skills without prompting, verbal or otherwise, or explanation by an instructor. In a within-subjects design, dressing skills that were presented at a relatively slow presentation speed through videotaped modelling were eventually performed better than those presented at a relatively fast speed. These data in combination with evidence from this laboratory that passive modelling of basic skills is more effective than interactive modelling (e.g., Biederman, Fairhall, Raven, & Davey, 1998; Biederman, Davey, Ryder, & Franchi, 1994; Biederman, Ryder, Davey, & Gibson, 1991) suggest that standard instructional techniques warrant reexamination both from the basis of instructional effectiveness and the efficient use of the allotment of teacher time.

[An analysis of the cDNA nucleotide sequence for the C-terminal fragment of the coat protein in tobacco mosaic virus isolates from tobacco growing in an ecological niche of Polesye, Ukraine]. / Analiz nukleotidnoi posledovatel'nosti kDNK dlia C-kontsevogo fragmenta belka obolochki VTM-izoliatov tabaka, proizrastavshego v ékologicheskoi nishe Poles'ia Ukrainy.

Two identical strains of tobacco type TVM have been isolated in the region with 137Cs nuclear contamination with density of 12.6 Cu/km2 recombinant plasmids (pTVM9, pTVM9,5) containing cDNA of complete provirus and C-end sequence of cDNA of specific capsid protein from one of isolated viruses have been obtained. The capsule proteins of isolated strains have the higher 19.5 +/- 1.9 kDa molecular weight than standard TVM strain (17.5 kDa) as to SDS-PAAG electrophoresis data. No differences in distribution of fragments immunoactive to control antiserum have been found when using immunoblot analysis of capsid proteins of isolates and standard strain treated by tripsin. Sequencing analysis of cDNA pTVM9,5 has revealed non-conservative amino acid replacement of serine by tyrosine in position 149 for homologous region of capsid protein of standard TVM strain, which allows to suppose the mediated effect of specific ecological situation on the appearance of such replacement.