Etiology of teacher knowledge and instructional skills for literacy at the upper elementary grades.

The purpose of this research was to study the etiology of teacher knowledge about and factors that influence implementation of evidence-based reading and writing interventions at the upper elementary grade levels. Five data sources are used in this study: first, we used teacher surveys about their pre-service preparation on reading comprehension and literacy practices gathered during a recent cluster randomized control trial on a reading comprehension intervention conducted with 280 fourth and fifth-grade teachers and their classroom students. We also conducted focus group interviews with 43% of the teachers and observed 90% of the teachers once during the implementation years. For writing, we used data collected from 32 teachers during a 3-year design project for a teacher-led computer-supported writing intervention. We also collected data from groups of school administrators using structured interviews during both studies. Finally, we conducted an artifact review of school curricula and posted professional development (PD) plans. Our results show that in both reading comprehension and writing, all teachers reported not receiving sound evidence-based pre-service preparation and they were not currently employing any evidence-based approaches. Most teachers reported using the basal reading series with very little variation from the lesson scope and sequence. Teachers and administrators frequently reported that skills were being taught in isolation (e.g., skill of the week is summarizing) and that writing was neglected. The interviews showed very interesting patterns of curricula decision-making by school administrators and these findings were further confirmed through the artifact reviews. Based on these results, we recommend that any review of teacher practices focus also on administrator decision-making and school level factors that are driving what happens in the classrooms. The review showed that the teachers themselves do not feel empowered to learn and deliver evidence-based literacy practices and feel constrained by the system.

"An adjective is a word hanging down from a noun": learning to write and students with learning disabilities.

By the upper elementary grades, writing becomes an essential tool both for learning and for showing what you know. Students who struggle significantly with writing are at a terrible disadvantage. Data from the National Assessment of Educational Progress indicate that only 25% of students can be classified as competent writers; students with learning disabilities (LD) have even greater problems with writing than their normally achieving peers and frequently demonstrate a deteriorating attitude toward writing after the primary grades. In this article, we focus on composing and the writing process, and examine the knowledge base about writing development and instruction among students with LD. We address what research tells us about skilled writers and the development of writing knowledge, strategies, skill, and the will to write, and how this relates to students with LD. Next, we summarize what has been learned from research on writing development, effective instruction, and the writing abilities of students with LD in terms of effective instruction for these students. Finally, we indicate critical areas for future research.

Non-synonymous single nucleotide polymorphisms in the watermelon eIF4E gene are closely associated with resistance to zucchini yellow mosaic virus.

Zucchini yellow mosaic virus (ZYMV) is one of the most economically important potyviruses infecting cucurbit crops worldwide. Using a candidate gene approach, we cloned and sequenced eIF4E and eIF(iso)4E gene segments in watermelon. Analysis of the nucleotide sequences between the ZYMV-resistant watermelon plant introduction PI 595203 (Citrullus lanatus var. lanatus) and the ZYMV-susceptible watermelon cultivar 'New Hampshire Midget' ('NHM') showed the presence of single nucleotide polymorphisms (SNPs). Initial analysis of the identified SNPs in association studies indicated that SNPs in the eIF4E, but not eIF(iso)4E, were closely associated to the phenotype of ZYMV-resistance in 70 F(2) and 114 BC(1R) progenies. Subsequently, we focused our efforts in obtaining the entire genomic sequence of watermelon eIF4E. Three SNPs were identified between PI 595203 and NHM. One of the SNPs (A241C) was in exon 1 and the other two SNPs (C309A and T554G) were in the first intron of the gene. SNP241 which resulted in an amino acid substitution (proline to threonine) was shown to be located in the critical cap recognition and binding area, similar to that of several plant species resistance to potyviruses. Analysis of a cleaved amplified polymorphism sequence (CAPS) marker derived from this SNP in F(2) and BC(1R) populations demonstrated a cosegregation between the CAPS-2 marker and their ZYMV resistance or susceptibility phenotype. When we investigated whether such SNP mutation in the eIF4E was also conserved in several other PIs of C. lanatus var. citroides, we identified a different SNP (A171G) resulting in another amino acid substitution (D71G) from four ZYMV-resistant C. lanatus var. citroides (PI 244018, PI 482261, PI 482299, and PI 482322). Additional CAPS markers were also identified. Availability of all these CAPS markers will enable marker-aided breeding of watermelon for ZYMV resistance.

Gene expression in developing watermelon fruit.

BACKGROUND: Cultivated watermelon form large fruits that are highly variable in size, shape, color, and content, yet have extremely narrow genetic diversity. Whereas a plethora of genes involved in cell wall metabolism, ethylene biosynthesis, fruit softening, and secondary metabolism during fruit development and ripening have been identified in other plant species, little is known of the genes involved in these processes in watermelon. A microarray and quantitative Real-Time PCR-based study was conducted in watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai var. lanatus] in order to elucidate the flow of events associated with fruit development and ripening in this species. RNA from three different maturation stages of watermelon fruits, as well as leaf, were collected from field grown plants during three consecutive years, and analyzed for gene expression using high-density photolithography microarrays and quantitative PCR. RESULTS: High-density photolithography arrays, composed of probes of 832 EST-unigenes from a subtracted, fruit development, cDNA library of watermelon were utilized to examine gene expression at three distinct time-points in watermelon fruit development. Analysis was performed with field-grown fruits over three consecutive growing seasons. Microarray analysis identified three hundred and thirty-five unique ESTs that are differentially regulated by at least two-fold in watermelon fruits during the early, ripening, or mature stage when compared to leaf. Of the 335 ESTs identified, 211 share significant homology with known gene products and 96 had no significant matches with any database accession. Of the modulated watermelon ESTs related to annotated genes, a significant number were found to be associated with or involved in the vascular system, carotenoid biosynthesis, transcriptional regulation, pathogen and stress response, and ethylene biosynthesis. Ethylene bioassays, performed with a closely related watermelon genotype with a similar phenotype, i.e. seeded, bright red flesh, dark green rind, etc., determined that ethylene levels were highest during the green fruit stage followed by a decrease during the white and pink fruit stages. Additionally, quantitative Real-Time PCR was used to validate modulation of 127 ESTs that were differentially expressed in developing and ripening fruits based on array analysis. CONCLUSION: This study identified numerous ESTs with putative involvement in the watermelon fruit developmental and ripening process, in particular the involvement of the vascular system and ethylene. The production of ethylene during fruit development in watermelon gives further support to the role of ethylene in fruit development in non-climacteric fruits.

Assessment and Intervention in Overcoming Writing Difficulties: An Illustration From the Self-Regulated Strategy Development Model.

The progress of a 12-year-old boy with learning disabilities and severe writing difficulties is followed from initial assessment through instruction in strategies for planning, revising, and managing the composing process. A validated instructional model, Self-Regulated Strategy Development (SRSD), was used to teach these processes. With SRSD, writing strategies are explicitly taught in combination with procedures for regulating the use of these strategies, the writing process, and any undesirable behaviors that may impede performance. Recommendations are offered to speech-language pathologists for applying the SRSD model to children experiencing writing difficulties.