Effects of Academic and Non-academic Instructional Approaches on Preschool ELLs\u27 English Language Development

The population of English Language Learners (ELLs) in the United States has been growing at an increasingly rapid rate (U. S. Census Bureau, 2010), and nowhere is this growth more evident than in U.S. public schools. As of school year 2010-11, nearly 25% of all students in the California public schools were English Language Learners (California Department of Education, 2013). The focus of this study was to explore to what extent this growing number of ELLs was developing English language in different types of preschool activities. The study investigated whether bilingual preschool children would engage more and use more of their second language (English) during teacher-structured (academic) or free play (non-academic) activities. In addition, the researcher investigated the perceptions of preschool teachers and parents of bilingual preschool children regarding the effects of academic and non-academic instructional approaches on student engagement and English language development. Study participants consisted of eight bilingual preschool children, twelve preschool teachers, and eight parents of the children participants. The children were between the ages of three and five. The ethnic background of the children varied and included Japanese, Portuguese, Mexican and Indonesian. The researcher utilized both quantitative and qualitative research approaches in this study. Data sources included 285 preschool observations made at one preschool in Northern California, teacher and parent surveys, and teacher and parent interviews. Data analysis consisted of descriptive statistics that included frequencies/percentages, means, and standard deviations. In addition, children\u27s observed scores were also analyzed by normative scales using standardized z-scores. The findings of this study indicated that bilingual children engaged and interacted dramatically more during free play (non-academic) preschool classroom activities than during teacher-structured (academic) activities. The free play activities during which children were the most engaged and used their second language, English, the most were: pretend play, free play, and monkey bars. Results demonstrated that unstructured free-play activities served as an affordance for building language, academic skills, and cultural capital. The teacher and parent survey and interview findings indicated that preschool teachers and parents perceive free play (non-academic) preschool activities as being more beneficial toward children\u27s engagement and English language development than academic (teacher-structured) activities. The study\u27s major implication is that free play (non-academic) activities may be much more helpful in developing preschool ELL students\u27 English language skills compared to teacher-structured (academic) activities. Greater English language development in the early preschool years may help students become more successful as they enter Kindergarten. Moreover, the importance of free-play activities may extend beyond preschool classrooms, and the researcher recommends that more unstructured social-based activities for ELLs be implemented in K-12 classrooms

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

Optimization of adsorptive removal of α-toluic acid by CaO2 nanoparticles using response surface methodology

The present work addresses the optimization of process parameters for adsorptive removal of α-toluic acid by calcium peroxide (CaO2) nanoparticles using response surface methodology (RSM). CaO2 nanoparticles were synthesized by chemical precipitation method and confirmed by Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) analysis which shows the CaO2 nanoparticles size range of 5–15 nm. A series of batch adsorption experiments were performed using CaO2 nanoparticles to remove α-toluic acid from the aqueous solution. Further, an experimental based central composite design (CCD) was developed to study the interactive effect of CaO2 adsorbent dosage, initial concentration of α-toluic acid, and contact time on α-toluic acid removal efficiency (response) and optimization of the process. Analysis of variance (ANOVA) was performed to determine the significance of the individual and the interactive effects of variables on the response. The model predicted response showed a good agreement with the experimental response, and the coefficient of determination, (R2) was 0.92. Among the variables, the interactive effect of adsorbent dosage and the initial α-toluic acid concentration was found to have more influence on the response than the contact time. Numerical optimization of process by RSM showed the optimal adsorbent dosage, initial concentration of α-toluic acid, and contact time as 0.03 g, 7.06 g/L, and 34 min respectively. The predicted removal efficiency was 99.50%. The experiments performed under these conditions showed α-toluic acid removal efficiency up to 98.05%, which confirmed the adequacy of the model prediction