93 research outputs found

    The Effect of Repeated Reading With Pairs of Students in a Large-Group Setting on Fluency and Comprehension for Students At Risk for Reading Failure

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    Problem. Some students are failing to develop acceptable reading skills; however, instructional time allocated to reading fluency can increase reading comprehension. The purpose of this study was to compare students who received repeated reading with pairs of students in a large-group setting with those who did not in terms of reading fluency, rates of reading fluency growth, and reading comprehension for students at risk for reading failure in a school in a Midwestern mid-sized city. Method. An experimental pretest-posttest with control group design was used with grade level stratified (2nd, 3rd, and 4th grade) intervention (N = 27) and control (N = 30) groups. All students were at risk for reading failure based onDynamic Indicators of Basic Early Literacy Skills Oral Reading Fluency (DORF). Socioeconomic data indicated 82% of the school\u27s students were eligible for the federal free or reduced-price lunch program. The students were homogenously paired and engaged in repeated reading in a large group using fiction and nonfiction stories at their instructional level. The study consisted of 32 sessions, 15 minutes per day, 3 to 4 days per week, over 7 weeks. The three dependent variables were pre- and posttest performance on the DORF, DORF progressing monitoring slope, and the Group Reading Assessment and Diagnostic Evaluation (GRADE). Results. The ANCOVA result for DORF was nonsignificant, F (1, 54) = .40, p = .529, partial = .01. The omnibus test of the 2 × 3 ANCOVA for DORF progress monitoring slope was nonsignificant, F (2, 47) = 2.49, p = .094, partial η \u3e2 = .10, indicating no significant interaction between the treatment condition and grade level. There was no significant main effect for grade level, F (2, 47) = .294, p = .746, partial η 2 = .01, but a significant main effect for condition was found, F (1, 47) = 7.80, p = .008, partial η2 = .14, Cohen\u27s d = 0.72. Students in the intervention group had a statistically significant steeper slope for rates of reading fluency growth, along with a medium to large effect size. The ANCOVA for GRADE was nonsignificant, F (1, 52) = 3.34, p = .074, partial η2 = .06. Conclusions. The theory of automaticity as applied to reading development was supported by the results. Repeated reading with pairs of students in a large-group setting was an effective intervention for rates of reading fluency growth (slope) for students at risk for reading failure; however, significant results were not found on pre- and posttests for fluency and comprehension. The short length of the study and sensitivity of the comprehension measure may not have allowed sufficient opportunity to detect changes in difference between the groups in these areas. This study demonstrated that one adult was able to facilitate the development of reading fluency with a classroom of students who were below standard

    Pleiotropy of Glycogen Synthase Kinase-3 Inhibition by CHIR99021 Promotes Self-Renewal of Embryonic Stem Cells from Refractory Mouse Strains

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    Background: Inhibition of glycogen synthase kinase-3 (GSK-3) improves the efficiency of embryonic stem (ES) cell derivation from various strains of mice and rats, as well as dramatically promotes ES cell self-renewal potential. b-catenin has been reported to be involved in the maintenance of self-renewal of ES cells through TCF dependent and independent pathway. But the intrinsic difference between ES cell lines from different species and strains has not been characterized. Here, we dissect the mechanism of GSK-3 inhibition by CHIR99021 in mouse ES cells from refractory mouse strains. Methodology/Principal Findings: We found that CHIR99021, a GSK-3 specific inhibitor, promotes self-renewal of ES cells from recalcitrant C57BL/6 (B6) and BALB/c mouse strains through stabilization of b-catenin and c-Myc protein levels. Stabilized b-catenin promoted ES self-renewal through two mechanisms. First, b-catenin translocated into the nucleus to maintain stem cell pluripotency in a lymphoid-enhancing factor/T-cell factor–independent manner. Second, b-catenin binds plasma membrane-localized E-cadherin, which ensures a compact, spherical morphology, a hallmark of ES cells. Further, elevated c-Myc protein levels did not contribute significantly to CH-mediated ES cell self-renewal. Instead, the role of c-Myc is dependent on its transformation activity and can be replaced by N-Myc but not L-Myc. b-catenin and c-Myc have similar effects on ES cells derived from both B6 and BALB/c mice. Conclusions/Significance: Our data demonstrated that GSK-3 inhibition by CH promotes self-renewal of mouse ES cell

    Attribution: how is it relevant for loss and damage policy and practice?

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    Attribution has become a recurring issue in discussions about Loss and Damage (L&D). In this highly-politicised context, attribution is often associated with responsibility and blame; and linked to debates about liability and compensation. The aim of attribution science, however, is not to establish responsibility, but to further scientific understanding of causal links between elements of the Earth System and society. This research into causality could inform the management of climate-related risks through improved understanding of drivers of relevant hazards, or, more widely, vulnerability and exposure; with potential benefits regardless of political positions on L&D. Experience shows that it is nevertheless difficult to have open discussions about the science in the policy sphere. This is not only a missed opportunity, but also problematic in that it could inhibit understanding of scientific results and uncertainties, potentially leading to policy planning which does not have sufficient scientific evidence to support it. In this chapter, we first explore this dilemma for science-policy dialogue, summarising several years of research into stakeholder perspectives of attribution in the context of L&D. We then aim to provide clarity about the scientific research available, through an overview of research which might contribute evidence about the causal connections between anthropogenic climate change and losses and damages, including climate science, but also other fields which examine other drivers of hazard, exposure, and vulnerability. Finally, we explore potential applications of attribution research, suggesting that an integrated and nuanced approach has potential to inform planning to avert, minimise and address losses and damages. The key messages are In the political context of climate negotiations, questions about whether losses and damages can be attributed to anthropogenic climate change are often linked to issues of responsibility, blame, and liability. Attribution science does not aim to establish responsibility or blame, but rather to investigate drivers of change. Attribution science is advancing rapidly, and has potential to increase understanding of how climate variability and change is influencing slow onset and extreme weather events, and how this interacts with other drivers of risk, including socio-economic drivers, to influence losses and damages. Over time, some uncertainties in the science will be reduced, as the anthropogenic climate change signal becomes stronger, and understanding of climate variability and change develops. However, some uncertainties will not be eliminated. Uncertainty is common in science, and does not prevent useful applications in policy, but might determine which applications are appropriate. It is important to highlight that in attribution studies, the strength of evidence varies substantially between different kinds of slow onset and extreme weather events, and between regions. Policy-makers should not expect the later emergence of conclusive evidence about the influence of climate variability and change on specific incidences of losses and damages; and, in particular, should not expect the strength of evidence to be equal between events, and between countries. Rather than waiting for further confidence in attribution studies, there is potential to start working now to integrate science into policy and practice, to help understand and tackle drivers of losses and damages, informing prevention, recovery, rehabilitation, and transformation

    Generation of tumor-initiating cells by exogenous delivery of OCT4 transcription factor

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    Abstract Introduction Tumor-initiating cells (TIC) are being extensively studied for their role in tumor etiology, maintenance and resistance to treatment. The isolation of TICs has been limited by the scarcity of this population in the tissue of origin and because the molecular signatures that characterize these cells are not well understood. Herein, we describe the generation of TIC-like cell lines by ectopic expression of the OCT4 transcription factor (TF) in primary breast cell preparations. Methods OCT4 cDNA was over-expressed in four different primary human mammary epithelial (HMEC) breast cell preparations from reduction mammoplasty donors. OCT4-transduced breast cells (OTBCs) generated colonies (frequency ~0.01%) in self-renewal conditions (feeder cultures in human embryonic stem cell media). Differentiation assays, immunofluorescence, immunohistochemistry, and flow cytometry were performed to investigate the cell of origin of OTBCs. Serial dilutions of OTBCs were injected in nude mice to address their tumorigenic capabilities. Gene expression microarrays were performed in OTBCs, and the role of downstream targets of OCT4 in maintaining self-renewal was investigated by knock-down experiments. Results OTBCs overcame senescence, overexpressed telomerase, and down-regulated p16INK4A . In differentiation conditions, OTBCs generated populations of both myoepithelial and luminal cells at low frequency, suggesting that the cell of origin of some OTBCs was a bi-potent stem cell. Injection of OTBCs in nude mice generated poorly differentiated breast carcinomas with colonization capabilities. Gene expression microarrays of OTBC lines revealed a gene signature that was over-represented in the claudin-low molecular subtype of breast cancer. Lastly, siRNA-mediated knockdown of OCT4 or downstream embryonic targets of OCT4, such as NANOG and ZIC1, suppressed the ability of OTBCs to self-renew. Conclusions Transduction of OCT4 in normal breast preparations led to the generation of cell lines possessing tumor-initiating and colonization capabilities. These cells developed high-grade, poorly differentiated breast carcinomas in nude mice. Genome-wide analysis of OTBCs outlined an embryonic TF circuitry that could be operative in TICs, resulting in up-regulation of oncogenes and loss of tumor suppressive functions. These OTBCs represent a patient-specific model system for the discovery of novel oncogenic targets in claudin-low tumors
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