Perception of suprasegmental features of speech by children with cochlear implants and children with hearing AIDS

This study assessed perception of suprasegmental features of speech by 30 prelingual children with sensorineural hearing loss. Ten children had cochlear implants (CIs), and 20 children wore hearing aids (HA): 10 with severe hearing loss and 10 with profound hearing loss. Perception of intonation, syllable stress, word emphasis, and word pattern was assessed. Results revealed that the two HA groups significantly outperformed the CI group in perceiving both intonation and stress. Within each group, word pattern was perceived best, and then intonation and emphasis, with syllable stress perceived poorest. No significant correlation emerged between age at implantation and perception of the various suprasegmental features, possibly due to participants' relatively late age at implantation. Results indicated that CI use did not show an advantage over HA use in the perception of suprasegmental features of speech. Future research should continue to explore variables that might improve this perception.     

Microwave-assisted synthesis, anticonvulsant activity and quantum mechanical modelling of N-（4-bromo-3-methylphenyl） semicarbazones

Objective： To study the effect of halo substitution on disubstituted aryl semicarbazones on the anticonvulsant potential and model the activity based on quantum mechanics. Methods： A series of twenty-six compounds of N^4-（4-bromo-3-methylphenyl） semicarbazones were synthesized and evaluated for the anticonvulsant activity in the maximal electroshock seizure （MES） and subcutaneous pentylenetetrazole （scPTZ） seizure threshold tests. Some potential compounds were also tested in the subcutaneous strychnine （scSTY） and subcutaneous picrotoxin （scPIC） seizure threshold tests. The synthesized compounds were tested for behavioral impairment and CNS （central nervous system） depression in mice. Quantum mechanical modelling was carried out on these compounds to gain understanding on the structural features essential for activity. Results： Some compounds possessed broad spectrum anticonvulsant activity as indicated by their effect in pentylenetetrazole, strychnine, picrotoxin and maximal electroshock seizures models in resemblance to other aryl semicarbazone derivatives reported earlier. The higher the difference in HOMO （highest occupied molecular orbital） and LUMO （lowest unoccupied molecular orbital） energy levels was, the greater was the activity profile. Conclusion： The pharmacophoric requirements for compounds to exhibit anticonvulsant activity that includes one aryl unit in proximity to a hydrogen donor-acceptor domain and an electron donor have been justified with the molecular orbital surface analysis of the synthesized compounds.     

Insecticidal activity of the medicinal plant, <Emphasis Type="Italic">Alstonia boonei</Emphasis> De Wild,against <Emphasis Type="Italic">Sesamia calamistis</Emphasis> Hampson

The bioactivity of the aqueous extracts of the leaf and stem bark of the medicinal plant, Alstonia boonei De Wild (Apocyanaceae), against the pink stalk borer, Sesamia calamistis Hampson (Lepidoptera: Noctuidae) was studied in a laboratory bioassay. The extracts were incorporated into artificial diet at a rate of 0.0% (control), 1.0%, 2.5%, 5.0%, and 10.0% (w/w). Both extracts significantly (P<0.01) reduced larval survival and weight in a dose dependent manner. The concentrations that killed 50% of the larvae (LC50) for the stem bark extract were 2.8% and 2.1% at 10 and 20 DAI (days after introduction), respectively, while those for the leaves extract were 5.6% and 3.5%. The weights of the larvae also varied significantly (P<0.05) between the treatments in a dose dependent manner. We conclude that both leaf and stem bark extracts of A. boonei are toxic, used as growth inhibitors to S. calamistis larvae, and hold good promise for use as alternative crop protectants against S. calamistis.     

QTL analysis for some quantitative traits in bread wheat

Quantitative trait loci (QTL) analysis was conducted in bread wheat for 14 important traits utilizing data from four different mapping populations involving different approaches of QTL analysis. Analysis for grain protein content (GPC) sug- gested that the major part of genetic variation for this trait is due to environmental interactions. In contrast, pre-harvest sprouting tolerance (PHST) was controlled mainly by main effect QTL (M-QTL) with very little genetic variation due to environmental interactions; a major QTL for PHST was detected on chromosome arm 3AL. For grain weight, one QTL each was detected on chromosome arms 1AS, 2BS and 7AS. QTL for 4 growth related traits taken together detected by different methods ranged from 37 to 40; nine QTL that were detected by single-locus as well as two-locus analyses were all M-QTL. Similarly, single-locus and two-locus QTL analyses for seven yield and yield contributing traits in two populations respectively allowed detection of 25 and 50 QTL by composite interval mapping (CIM), 16 and 25 QTL by multiple-trait composite interval mapping (MCIM) and 38 and 37 QTL by two-locus analyses. These studies should prove useful in QTL cloning and wheat improvement through marker aided selection.     

Teachers' education, classroom quality, and young children's academic skills: results from seven studies of preschool programs

In an effort to provide high-quality preschool education, policymakers are increasingly requiring public preschool teachers to have at least a Bachelor's degree, preferably in early childhood education. Seven major studies of early care and education were used to predict classroom quality and children's academic outcomes from the educational attainment and major of teachers of 4-year-olds. The findings indicate largely null or contradictory associations, indicating that policies focused solely on increasing teachers' education will not suffice for improving classroom quality or maximizing children's academic gains. Instead, raising the effectiveness of early childhood education likely will require a broad range of professional development activities and supports targeted toward teachers' interactions with children.     

A new look at infant pointing

The current article proposes a new theory of infant pointing involving multiple layers of intentionality and shared intentionality. In the context of this theory, evidence is presented for a rich interpretation of prelinguistic communication, that is, one that posits that when 12-month-old infants point for an adult they are in some sense trying to influence her mental states. Moreover, evidence is also presented for a deeply social view in which infant pointing is best understood--on many levels and in many ways--as depending on uniquely human skills and motivations for cooperation and shared intentionality (e.g., joint intentions and attention with others). Children's early linguistic skills are built on this already existing platform of prelinguistic communication.     

Locus and nature of perceptual phonological deficit in Spanish children with reading disabilities

The aims of this study were (a) to determine whether Spanish children with reading disabilities (RD) show a speech perception deficit and (b) to explore the locus and nature of this perceptive deficit. A group of 29 children with RD, 41 chronological age-matched controls, and 27 reading ability-matched younger controls were tested on tasks of speech perception. The effect of linguistic unit (word vs. syllable) and type of phonetic contrast (voicing, place and manner of articulation) were analyzed in terms of the number of errors and the response time. The results revealed a speech perception deficit in Spanish children with RD that was independent of the type of phonetic contrast and of linguistic unit.     

Toward a resolution of inconsistencies in the phonological deficit theory of reading disorders: phonological reading difficulties are more severe in high-IQ poor readers

This study examined whether high- and low-IQ poor readers differed in patterns of reading performance. Ten-year-old poor readers with IQ scores of 110 and higher showed difficulty in taking a phonological approach to reading, failing to show an advantage in reading high-frequency regular versus irregular words and showing impaired nonword reading accuracy for their reading age. However, poor readers with IQ scores of 90 and below showed a more phonological approach to reading, with better reading of regular than irregular words of both high and low frequency, and with nonword reading skills slower than, but as accurate as, those of reading-age controls. We concluded that the high-IQ poor readers experienced difficulty in taking a phonological approach to reading, whereas the low-IQ poor readers had much less marked phonological problems, supporting Stanovich's phonological-core variable-difference model.