36 research outputs found

    Ability Grouping and Student Achievement in Four Rural Elementary Schools in the Southern United States

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    School personnel are concerned that reading gaps of grade 3 and grade 4 students have persisted in 4 rural elementary schools in the southern United States despite the use of ability grouping to improve student reading proficiency scores. Between the 2014-2016 school years, less than 50% of students in grades 3 and grade 4 scored at the proficient level in reading at the 4 target rural schools. The purpose of this qualitative case study was to examine the teachers\u27 and administrators\u27 perceptions regarding the influence of grouping on the reading performance of students in grades 3 and 4. Using Vygotsky\u27s framework, the research investigated teachers\u27 and administrators\u27 perceptions of grouping and nongrouping in relation to students\u27 reading progress, socioeconomic status, and achievement gaps between minority and non-minority students. Using purposeful sampling, interview data were collected from 4 administrators who met the criteria of working in a target site that used ability and nonability grouping. Teacher data came from focus groups, and surveys from 15 teacher participants who met the criteria of being certified in English Language Arts, and assigned to Grades 3 and/or 4 in ability or nonability grouping environments. Using emergent coding, themes supported the findings that assessment strategies are positively and negatively perceived, nonability grouping is preferred, reading achievement is perceived as higher in nonability grouping, and gaps in learning are influenced by socioeconomic status. Based on this research the use of nonability grouping may promote greater positive social change that will enhance student success in reading

    World Literature I: Beginnings to 1650

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    This peer-reviewed World Literature I anthology includes introductory text and images before each series of readings. Sections of the text are divided by time period in three parts: the Ancient World, Middle Ages, and Renaissance, and then divided into chapters by location. World Literature I and the Compact Anthology of World Literature are similar in format and both intended for World Literature I courses, but these two texts are developed around different curricula. Accessible files with optical character recognition (OCR) and auto-tagging provided by the Center for Inclusive Design and Innovation.https://oer.galileo.usg.edu/english-textbooks/1005/thumbnail.jp

    Off-target piRNA gene silencing in Drosophila melanogaster rescued by a transposable element insertion

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    Transposable elements (TE) are selfish genetic elements that can cause harmful mutations. In Drosophila, it has been estimated that half of all spontaneous visible marker phenotypes are mutations caused by TE insertions. Several factors likely limit the accumulation of exponentially amplifying TEs within genomes. First, synergistic interactions between TEs that amplify their harm with increasing copy number are proposed to limit TE copy number. However, the nature of this synergy is poorly understood. Second, because of the harm posed by TEs, eukaryotes have evolved systems of small RNA-based genome defense to limit transposition. However, as in all immune systems, there is a cost of autoimmunity and small RNA-based systems that silence TEs can inadvertently silence genes flanking TE insertions. In a screen for essential meiotic genes in Drosophila melanogaster, a truncated Doc retrotransposon within a neighboring gene was found to trigger the germline silencing of ald, the Drosophila Mps1 homolog, a gene essential for proper chromosome segregation in meiosis. A subsequent screen for suppressors of this silencing identified a new insertion of a Hobo DNA transposon in the same neighboring gene. Here we describe how the original Doc insertion triggers flanking piRNA biogenesis and local gene silencing. We show that this local gene silencing occurs in cis and is dependent on deadlock, a component of the Rhino-Deadlock-Cutoff (RDC) complex, to trigger dual-strand piRNA biogenesis at TE insertions. We further show how the additional Hobo insertion leads to de-silencing by reducing flanking piRNA biogenesis triggered by the original Doc insertion. These results support a model of TE-mediated gene silencing by piRNA biogenesis in cis that depends on local determinants of transcription. This may explain complex patterns of off-target gene silencing triggered by TEs within populations and in the laboratory. It also provides a mechanism of sign epistasis among TE insertions, illuminates the complex nature of their interactions and supports a model in which off-target gene silencing shapes the evolution of the RDC complex

    Mutations in KEOPS-Complex Genes Cause Nephrotic Syndrome with Primary Microcephaly

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    Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms

    Activation of MEF2 by muscle activity is mediated through a calcineurin-dependent pathway

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    Gene expression in skeletal muscles of adult vertebrates is altered profoundly by changing patterns of contractile work. Here we observed that the functional activity of MEF2 transcription factors is stimulated by sustained periods of endurance exercise or motor nerve pacing, as assessed by expression in trans genic mice of a MEF2-dependent reporter gene (desMEF2-lacZ). This response is accompanied by transformation of specialized myofiber subtypes, and is blocked either by cyclosporin A, a specific chemical inhibitor of calcineurin, or by forced expression of the endogenous calcineurin inhibitory protein, myocyte-enriched calcineurin interacting protein 1. Calcineurin removes phosphate groups from MEF2, and augments the potency of the transcriptional activation domain of MEF2 fused to a heterologous DNA binding domain. Across a broad range, the enzymatic activity of calcineurin correlates directly with expression of endogenous genes that are transcriptionally activated by muscle contractions. These results delineate a molecular pathway in which calcineurin and MEF2 participate in the adaptive mechanisms by which skeletal myofibers acquire specialized contractile and metabolic properties as a function of changing patterns of muscle contraction
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