Updated perspectives on educational diagnosticians’ understanding of reading assessments

Chappell, Stephens, Kinnison, and Pettigrew (2009) conducted a study investigating educational diagnosticians knowledge of early reading development. Our study replicated the work of Chappell et al. through a mixed methods design that investigated educational diagnosticians’ perceptions and knowledge of early reading development. Additionally, our study sought to gain a better understanding of how educational diagnosticians selected assessment instruments. Our findings suggested that educational diagnosticians may lack understanding of the early developmental processes of reading and that there may be limited use of diagnostic assessment instruments when evaluating students who are struggling to read

Internal validation of STRmix™ – A multi laboratory response to PCAST

We report a large compilation of the internal validations of the probabilistic genotyping software STRmix™. Thirty one laboratories contributed data resulting in 2825 mixtures comprising three to six donors and a wide range of multiplex, equipment, mixture proportions and templates. Previously reported trends in the LR were confirmed including less discriminatory LRs occurring both for donors and non-donors at low template (for the donor in question) and at high contributor number. We were unable to isolate an effect of allelic sharing. Any apparent effect appears to be largely confounded with increased contributor number

Extensive microbial and functional diversity within the chicken cecal microbiome

Chickens are major source of food and protein worldwide. Feed conversion and the health of chickens relies on the largely unexplored complex microbial community that inhabits the chicken gut, including the ceca. We have carried out deep microbial community profiling of the microbiota in twenty cecal samples via 16S rRNA gene sequences and an in-depth metagenomics analysis of a single cecal microbiota. We recovered 699 phylotypes, over half of which appear to represent previously unknown species. We obtained 648,251 environmental gene tags (EGTs), the majority of which represent new species. These were binned into over two-dozen draft genomes, which included Campylobacter jejuni and Helicobacter pullorum. We found numerous polysaccharide- and oligosaccharide-degrading enzymes encoding within the metagenome, some of which appeared to be part of polysaccharide utilization systems with genetic evidence for the co-ordination of polysaccharide degradation with sugar transport and utilization. The cecal metagenome encodes several fermentation pathways leading to the production of short-chain fatty acids, including some with novel features. We found a dozen uptake hydrogenases encoded in the metagenome and speculate that these provide major hydrogen sinks within this microbial community and might explain the high abundance of several genera within this microbiome, including Campylobacter, Helicobacter and Megamonas

Conserved Genes Act as Modifiers of Invertebrate SMN Loss of Function Defects

Spinal Muscular Atrophy (SMA) is caused by diminished function of the Survival of Motor Neuron (SMN) protein, but the molecular pathways critical for SMA pathology remain elusive. We have used genetic approaches in invertebrate models to identify conserved SMN loss of function modifier genes. Drosophila melanogaster and Caenorhabditis elegans each have a single gene encoding a protein orthologous to human SMN; diminished function of these invertebrate genes causes lethality and neuromuscular defects. To find genes that modulate SMN function defects across species, two approaches were used. First, a genome-wide RNAi screen for C. elegans SMN modifier genes was undertaken, yielding four genes. Second, we tested the conservation of modifier gene function across species; genes identified in one invertebrate model were tested for function in the other invertebrate model. Drosophila orthologs of two genes, which were identified originally in C. elegans, modified Drosophila SMN loss of function defects. C. elegans orthologs of twelve genes, which were originally identified in a previous Drosophila screen, modified C. elegans SMN loss of function defects. Bioinformatic analysis of the conserved, cross-species, modifier genes suggests that conserved cellular pathways, specifically endocytosis and mRNA regulation, act as critical genetic modifiers of SMN loss of function defects across species

The missing Spanish creoles: recovering the birth of plantation contact languages

John McWhorter challenges an enduring paradigm among linguists in this provocative exploration of the origins of plantation creoles. Using a wealth of data--linguistic, sociolinguistic, historical--he proposes that the "limited access model" of creole genesis is seriously flawed. That model maintains that plantation creole languages emerged because African slaves greatly outnumbered whites on colonial plantations. Having little access to the slaveholders' European languages, the slaves were forced to build a new language from what fragments they did acquire. Not so, says McWhorter, who posits that plantation creole originated in West African trade settlements, in interactions between white traders and slaves, some of whom were eventually transported overseas. The evidence that most New World creoles were imports traceable to West Africa strongly suggests that the well-established limited access model for plantation creole needs revision. In forcing a reexamination of this basic tenet, McWhorter's book will undoubtedly cause controversy. At the same time, it makes available a vast amount of data that will be a valuable resource for further explorations of genesis theory