61 research outputs found

    Assessing Learning-Centered Leadership: Connections to Research, Professional Standards, and Current Practices

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    Describes an assessment model designed to evaluate school leaders' performance. Unlike existing tools, this new system will assess both individuals and teams, and focuses specifically on instructional leadership and behaviors that improve learning

    Mechanisms of bone loss in inflammatory arthritis: diagnosis and therapeutic implications

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    Rheumatoid arthritis represents an excellent model in which to gain insights into the local and systemic effects of joint inflammation on skeletal tissues. Three forms of bone disease have been described in rheumatoid arthritis. These include: focal bone loss affecting the immediate subchondral bone and bone at the joint margins; periarticular osteopenia adjacent to inflamed joints; and generalized osteoporosis involving the axial and appendicular skeleton. Although these three forms of bone loss have several features in common, careful histomorphometric and histopathological analysis of bone tissues from different skeletal sites, as well as the use of urinary and serum biochemical markers of bone remodeling, provide compelling evidence that different mechanisms are involved in their pathogenesis. An understanding of these distinct pathological forms of bone loss has relevance not only with respect to gaining insights into the different pathological mechanisms, but also for developing specific and effective strategies for preventing the different forms of bone loss in rheumatoid arthritis

    Changing Principals\u27 Leadership through Feedback and Coaching

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    Researchers Leonard Bickman, Ellen Goldring, Peter Goff, and J. Edward Guthrie conducted a randomized experiment of principals in a large urban school district to explore if coaching, when combined with feedback from teachers, changes principals’ leadership practices. This brief summarizes the research findings regarding the impact of the feedback and coaching intervention on principals’ leadership behaviors

    The role of TNF-receptor family members and other TRAF-dependent receptors in bone resorption

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    The contribution of osteoclasts to the process of bone loss in inflammatory arthritis has recently been demonstrated. Studies in osteoclast biology have led to the identification of factors responsible for the differentiation and activation of osteoclasts, the most important of which is the receptor activator of NF-κB ligand/osteoclast differentiation factor (RANKL/ODF), a tumor necrosis factor (TNF)-like protein. The RANKL/ODF receptor, receptor activator of NF-κB (RANK), is a TNF-receptor family member present on both osteoclast precursors and mature osteoclasts. Like other TNF-family receptors and the IL-1 receptor, RANK mediates its signal transduction via TNF receptor-associated factor (TRAF) proteins, suggesting that the signaling pathways activated by RANK and other inflammatory cytokines involved in osteoclast differentiation and activation are interconnected

    The role played by cell-substrate interactions in the pathogenesis of osteoclast-mediated peri-implant osteolysis

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    Prosthetic wear debris-induced peri-implant osteolysis is a major cause of aseptic loosening after total joint replacement. In this condition, wear particles released from the implant components induce a granulomatous inflammatory reaction at the interface between implant and adjacent bone, leading to progressive bone resorption and loss of fixation. The present study was undertaken to characterize definitively the phenotype of osteoclast-like cells associated with regions of peri-implant focal bone resorption and to compare the phenotypic features of these cells with those of mononucleated and multinucleated cells associated with polyethylene wear particles. Peri-implant tissues were obtained from patients undergoing hip revision surgery for aseptic loosening after total joint replacement. Cells were examined for the expression of several markers associated with the osteoclast phenotype using immunohistochemistry, histochemistry, and/or in situ hybridization. CD68 protein, a marker expressed by multiple macrophage lineage cell types, was detected in mononucleated and multinucleated cells associated with polyethylene particles and the bone surface. Cathepsin K and tartrate-resistant acid phosphatase were expressed highly in both mononucleated and multinucleated cells associated with the bone surface. Levels of expression were much lower in cells associated with polyethylene particles. High levels of β(3 )integrin protein were detected in cells in contact with bone. Multinucleated cells associated with polyethylene particles exhibited faint positive staining. Calcitonin receptor mRNA expression was detected solely in multinucleated cells present in resorption lacunae on the bone surface and was absent in cells associated with polyethylene particles. Our findings provide further evidence that cells expressing the full repertoire of osteoclast phenotypic markers are involved in the pathogenesis of peri-implant osteolysis after total joint replacement. They also demonstrate that foreign body giant cells, although believed to be phenotypically and functionally distinct from osteoclasts, express many osteoclast-associated genes and gene products. However, the levels and patterns of expression of these genes in the two cell types differ. We speculate that, in addition to the role of cytokines and growth factors, the substrate with which these cells interact plays a critical role in their differential phenotypic and functional properties

    Changing the Principal Supervisor Role to Better Support Principals: Evidence from the Principal Supervisor Initiative

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    The principal supervisor job has traditionally revolved around administration, operations and compliance, but as principals have increasingly been called on in recent years to concentrate on supporting high-quality teaching, the idea of a complementary makeover of the supervisor job has gained attention. In 2014, with funding from The Wallace Foundation, six large school districts around the country embarked on a four-year, $24-million initiative to redesign the supervisor position so it focused primarily on supporting principals in their role as instructional leaders.This report, which looks at the final year and the effects of the Principal Supervisor Initiative, concludes that the effort succeeded in changing the job so that it centered on developing and evaluating principals to help them promote effective teaching and learning in their schools. Over the course of the initiative, principals' ratings of their supervisors' effectiveness rose from 3.88 to 4.10 on a scale of 1-to-5, a statistically significant increase. Principals reported greater frequency of supervisor practices to develop school leadership—such as helping principals with data analysis, providing them with useful feedback and working with them to assess teacher effectiveness

    A Novel Role for GADD45\u3ci\u3eβ\u3c/i\u3e as a Mediator of \u3ci\u3eMMP-13\u3c/i\u3e Gene Expression during Chondrocyte Terminal Differentiation

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    The growth arrest and DNA damage-inducible 45β (GADD45β) gene product has been implicated in the stress response, cell cycle arrest, and apoptosis. Here we demonstrated the unexpected expression of GADD45β in the embryonic growth plate and uncovered its novel role as an essential mediator of matrix metalloproteinase-13 (MMP-13) expression during terminal chondrocyte differentiation. We identified GADD45β as a prominent early response gene induced by bone morphogenetic protein-2 (BMP-2) through a Smad1/Runx2-dependent pathway. Because this pathway is involved in skeletal development, we examined mouse embryonic growth plates, and we observed expression of Gadd45β mRNA coincident with Runx2 protein in prehypertrophic chondrocytes, whereas GADD45β protein was localized prominently in the nucleus in late stage hypertrophic chondrocytes where Mmp-13 mRNA was expressed. In Gadd45β−/− mouse embryos, defective mineralization and decreased bone growth accompanied deficient Mmp-13 and Col10a1 gene expression in the hypertrophic zone. Transduction of small interferin

    The Role of Assistant Principals: Evidence and Insights for Advancing School Leadership

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    Over the past 25 years, the number of assistant principals has been steadily increasing, as has the number of principals with prior experience as an assistant principal. However, the knowledge base on assistant principals has not grown in parallel with their increased presence in schools.Policymakers, practitioners, and researchers have not reached consensus on what the assistant principal role should entail, how to best prepare and support assistant principals, and how to effectively prepare them for success as principals. There is also little discussion about how the assistant principal role can promote equity and diversity in the pathway to the principalship as well as contribute to equitable experiences and outcomes for students, teachers, and staff.In this report, we present the results of a systematic synthesis of 79 empirical research studies on assistant principals published since 2000, including both quantitative and qualitative studies. To address gaps in this research base, we supplement the synthesis with new analyses of national data and data from two states, Tennessee and Pennsylvania. This report provides a descriptive portrait of the assistant principal role. It then addresses two important issues: diversity and equity among assistant principals and assistant principals' influence on student and school outcomes
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