The Impact of Dual-Tasking on Sentence Comprehension in Children with Specific Language Impairment

Purpose: This study assesses the hypothesis of a limitation in attentional allocation capacity as underlying poor sentence comprehension in children with SLI. Method: Fifteen children with SLI, 15 age-matched controls, and 15 grammar-matched controls. Sixty sentences were presented in isolation, and 60 sentences were presented with a concurrent non-linguistic target-detection task. If poor attentional allocation capacity is a core deficit in SLI, they should be impaired to a greater extent in the dual task condition relative to the grammatical-age controls. On the contrary, a comparable performance decrement under the dual-task condition in children with SLI and younger language controls would attest of a limitation in attentional allocation capacity in children with SLI that is not disproportionate to their language level. Results: Sentence comprehension was affected by the dual-task condition to a greater extent in children with SLI relative to age-controls, but not relative to grammatical-controls. Conclusions: Our study does not support limitations in attentional allocation capacity as representing a core deficit in SLI. Rather, our data show that these children show attentional allocation capacity comparable to that of younger children having similar language level, suggesting that SLI is characterized by a slowed development of both attentional and language domains

Genetic and expression analysis of cattle identifies candidate genes in pathways responding to Trypanosoma congolense infection

African bovine trypanosomiasis caused by Trypanosoma sp., is a major constraint on cattle productivity in sub-Saharan Africa. Some African Bos taurus breeds are highly tolerant of infection, but the potentially more productive Bos indicus zebu breeds are much more susceptible. Zebu cattle are well adapted for plowing and haulage, and increasing their tolerance of trypanosomiasis could have a major impact on crop cultivation as well as dairy and beef production. We used three strategies to obtain short lists of candidate genes within QTL that were previously shown to regulate response to infection. We analyzed the transcriptomes of trypanotolerant N'Dama and susceptible Boran cattle after infection with Trypanosoma congolense. We sequenced EST libraries from these two breeds to identify polymorphisms that might underlie previously identified quantitative trait loci (QTL), and we assessed QTL regions and candidate loci for evidence of selective sweeps. The scan of the EST sequences identified a previously undescribed polymorphism in ARHGAP15 in the Bta2 trypanotolerance QTL. The polymorphism affects gene function in vitro and could contribute to the observed differences in expression of the MAPK pathway in vivo. The expression data showed that TLR and MAPK pathways responded to infection, and the former contained TICAM1, which is within a QTL on Bta7. Genetic analyses showed that selective sweeps had occurred at TICAM1 and ARHGAP15 loci in African taurine cattle, making them strong candidates for the genes underlying the QTL. Candidate QTL genes were identified in other QTL by their expression profile and the pathways in which they participate