Intervention for word-finding difficulty for children starting school who have diverse language backgrounds

Children who have word-finding difficulty can be identified by the pattern of disfluencies in their spontaneous speech; in particular whole-word repetition of prior words often occurs when they cannot retrieve the subsequent word. Work is reviewed that shows whole-word repetitions can be used to identify children from diverse language backgrounds who have word-finding difficulty. The symptom-based identification procedure was validated using a non-word repetition task. Children who were identified as having word-finding difficulty were given phonological training that taught them features of English that they lacked (this depended on their language background). Then they received semantic training. In the cases of children whose first language was not English, the children were primed to use English and then presented with material where there was interference in meanings across the languages (English names had to be produced). It was found that this training improved a range of outcome measures related to education

Phylogenetic and structural analysis of centromeric DNA and kinetochore proteins

BACKGROUND: Kinetochores are large multi-protein structures that assemble on centromeric DNA (CEN DNA) and mediate the binding of chromosomes to microtubules. Comprising 125 base-pairs of CEN DNA and 70 or more protein components, Saccharomyces cerevisiae kinetochores are among the best understood. In contrast, most fungal, plant and animal cells assemble kinetochores on CENs that are longer and more complex, raising the question of whether kinetochore architecture has been conserved through evolution, despite considerable divergence in CEN sequence. RESULTS: Using computational approaches, ranging from sequence similarity searches to hidden Markov model-based modeling, we show that organisms with CENs resembling those in S. cerevisiae (point CENs) are very closely related and that all contain a set of 11 kinetochore proteins not found in organisms with complex CENs. Conversely, organisms with complex CENs (regional CENs) contain proteins seemingly absent from point-CEN organisms. However, at least three quarters of known kinetochore proteins are present in all fungi regardless of CEN organization. At least six of these proteins have previously unidentified human orthologs. When fungi and metazoa are compared, almost all have kinetochores constructed around Spc105 and three conserved multi-protein linker complexes (MIND, COMA, and the NDC80 complex). CONCLUSION: Our data suggest that critical structural features of kinetochores have been well conserved from yeast to man. Surprisingly, phylogenetic analysis reveals that human kinetochore proteins are as similar in sequence to their yeast counterparts as to presumptive Drosophila melanogaster or Caenorhabditis elegans orthologs. This finding is consistent with evidence that kinetochore proteins have evolved very rapidly relative to components of other complex cellular structures