Does classroom composition make a difference: effects on developments in motivation, sense of classroom belonging, and achievement in upper primary school

The present study investigated the effects of socioeconomic and ethnic classroom composition on developments in students’ motivation, sense of classroom belonging, and achievement. A sample of 722 primary school students completed questionnaires from 3rd to 6th grade. Latent growth curve analyses revealed that the reading comprehension scores of students with a low socioeconomic status (SES) were lower for each measurement in more socioeconomically disadvantaged classes, whereas these scores were higher in classes with more ethnic minority students. In practice, these effects may often cancel each other out. Furthermore, in classes with a high share of low-SES or ethnic minority students, students of all backgrounds showed more positive developments in motivation. These findings contradict commonly held fears that disadvantaged students "bring down" other students in the classroom. The results furthermore highlight the importance of studying longitudinal developments

Profiles of teachers’ need-support: How do autonomy support, structure, and involvement cohere and predict motivation and learning outcomes?

According to Self-Determination Theory, need-supportive teaching fosters students’ motivation. Thepresent study examined the interplay between the three dimensions of need support: autonomy support,structure, and involvement. Using both student and teacher-reports (N ¼ 287 Grade 7 students),configurations of need support were examined with Latent Profile Analyses. Balanced profiles wereidentified based on student reports (low, moderate, or high need support), while unbalanced profileswere identified based on student-specific teacher-reports. Higher levels of need support were associatedwith more motivation and achievement, while high levels of teacher-reported structure and involvementcould not compensate for a lack of teacher-reported autonomy support.Education and Child Studie

Low cost, low tech SNP genotyping tools for resource-limited areas: Plague in Madagascar as a model

Genetic analysis of pathogenic organisms is a useful tool for linking human cases together and/or to potential environmental sources. The resulting data can also provide information on evolutionary patterns within a targeted species and phenotypic traits. However, the instruments often used to generate genotyping data, such as single nucleotide polymorphisms (SNPs), can be expensive and sometimes require advanced technologies to implement. This places many genotyping tools out of reach for laboratories that do not specialize in genetic studies and/or lack the requisite financial and technological resources. To address this issue, we developed a low cost and low tech genotyping system, termed agarose-MAMA, which combines traditional PCR and agarose gel electrophoresis to target phylogenetically informative SNPs

Melt analysis of mismatch amplification mutation assays (melt-MAMA): a functional study of a cost-effective SNP genotyping assay in bacterial models.

Single nucleotide polymorphisms (SNPs) are abundant in genomes of all species and biologically informative markers extensively used across broad scientific disciplines. Newly identified SNP markers are publicly available at an ever-increasing rate due to advancements in sequencing technologies. Efficient, cost-effective SNP genotyping methods to screen sample populations are in great demand in well-equipped laboratories, but also in developing world situations. Dual Probe TaqMan assays are robust but can be cost-prohibitive and require specialized equipment. The Mismatch Amplification Mutation Assay, coupled with melt analysis (Melt-MAMA), is flexible, efficient and cost-effective. However, Melt-MAMA traditionally suffers from high rates of assay design failures and knowledge gaps on assay robustness and sensitivity. In this study, we identified strategies that improved the success of Melt-MAMA. We examined the performance of 185 Melt-MAMAs across eight different pathogens using various optimization parameters. We evaluated the effects of genome size and %GC content on assay development. When used collectively, specific strategies markedly improved the rate of successful assays at the first design attempt from ~50% to ~80%. We observed that Melt-MAMA accurately genotypes across a broad DNA range (~100 ng to ~0.1 pg). Genomic size and %GC content influence the rate of successful assay design in an independent manner. Finally, we demonstrated the versatility of these assays by the creation of a duplex Melt-MAMA real-time PCR (two SNPs) and conversion to a size-based genotyping system, which uses agarose gel electrophoresis. Melt-MAMA is comparable to Dual Probe TaqMan assays in terms of design success rate and accuracy. Although sensitivity is less robust than Dual Probe TaqMan assays, Melt-MAMA is superior in terms of cost-effectiveness, speed of development and versatility. We detail the parameters most important for the successful application of Melt-MAMA, which should prove useful to the wider scientific community