476 research outputs found

    Toward a More Loving Assessment Practice

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    One distinguishing mark of the Christ-follower is meant to be love - for God and for neighbor. What does this mean in the context of our everyday work as teachers or teacher educators? This paper specifically explores the relevance of loving heart attitudes for assessing student work. This paper first provides a conceptual foundation to justify taking up a lens of love while looking at student work and then reports on findings from a self-study of my own assessment practice. This paper highlights the importance of moment by moment disciplined choice to look away from self and self-interest towards the good of others

    Thyroxine is the serum factor that regulates morphogenesis of columnar cartilage from isolated chondrocytes in chemically defined medium.

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    Epiphyseal chondrocytes cultured in a medium containing 10% serum may be maintained as three dimensional aggregates and differentiate terminally into hypertrophic cells. There is an attendant expression of genes encoding type X collagen and high levels of alkaline phosphatase activity. Manipulation of the serum concentration to optimal levels of 0.1 or 0.01% in this chondrocyte pellet culture system results in formation of features of developing cartilage architecture which have been observed exclusively in growth cartilage in vivo. Cells are arranged in columns radiating out from the center of the tissue, and can be divided into distinct zones corresponding to the recognized stages of chondrocyte differentiation. Elimination of the optimal serum concentration in a chemically defined medium containing insulin eliminates the events of terminal differentiation of defined cartilage architecture. Chondrocytes continue to enlarge into hypertrophic cells and synthesize type X collagen mRNA and protein, but in the absence of the optimal serum concentration, alkaline phosphatase activity does not increase and the cells retain a random orientation. Addition of thyroxine to the chemically defined medium containing insulin and growth hormone results in dose-dependent increases in both type X collagen synthesis and alkaline phosphatase activity, and reproduces the optimal serum-induced morphogenesis of chondrocytes into a columnar pattern. These experiments demonstrate the critical role of thyroxine in cartilage morphogenesis

    Teacher Candidates as Writers: What is the Relationship Between Writing Experiences and Pedagogical Practice

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    Both teacher candidates (TCs) and practicing teachers are asked to engage in personal writing experiences as means of learning about writing instruction. Yet, research on the relationship between writing and teaching writing provides variable, sometimes contradictory, results. This study investigated the relationship between TCs’ experiences writing a personal narrative in an undergraduate teacher education course and how they read and respond to a second grader’s personal narrative. Results indicate that, initially, many TCs did not draw on their writing experiences to inform how they analyzed, interpreted, and responded to the student’s composition. However, when specifically prompted to think about their writing experiences in the course, 89% were able to notice features in the child’s writing that they had learned to include in their own writing. The authors offer a theoretical framework to explain the results and argue that the framework could be used to guide writing teacher educators as they design writing experiences for teacher candidates. This study provides insights into teachers as writers and how writing experiences impact teachers candidates’ writing pedagogy

    Construction Specifications And Analysis Of Rehabilitation Techniques Of Pervious Concrete Pavement

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    The primary objective of this study is to evaluate the clogging potential of installed pervious concrete systems, to analyze rehabilitation techniques and develop construction specifications for the construction of portland cement pervious concrete specific to the state of Florida. Currently, a consistent statewide policy has not been established in reference to credit for storage volume within the voids in pervious concrete and the coarse aggregate base. For this reason a current and updated assessment of pervious pavement is needed to benefit from the advantages of pervious pavement use in low traffic volume areas. Initially by modeling a pervious concrete system in a field laboratory with test cells of typical Florida soil conditions and groundwater elevations and combining these data with field data from multiple sites of long service life, a Florida specific construction methodology has been developed. It is hoped that by developing a more standardized design criteria for pervious pavements in Florida a statewide acceptance of portland cement pervious pavement can be achieved and credit can be earned based on the volume of stored stormwater. This study of field sites was subsequently expanded to include locations in the southeastern United States. Pervious concrete has suffered historically poor support due to a number of factors, including concern about poor long term performance due to clogging of surface pores. Eight existing parking lots were evaluated to determine the infiltration rates of pervious concrete systems that have had relatively no maintenance. Infiltration rates were measured using an embedded single-ring infiltrometer developed specifically for testing pervious concrete in an in-situ state. The average infiltration rates of the pervious concrete that was properly constructed at the investigated sites ranged from 0.4 to 227.2 inches per hour. A total of 30 pervious concrete cores were extracted and evaluated for infiltration rates after various rehabilitation techniques, including pressure washing, vacuum sweeping and a combination of the two methods, have been performed to rehabilitate the infiltration capability of the concrete. By evaluating the effectiveness of these rehabilitation techniques, recommendations have been developed for a maintenance schedule for pervious concrete installations. In most cases it was found that the three methods of maintenance investigated in this study typically resulted in a 200% or greater increase over the original infiltration rates of the pervious concrete cores. It is therefore recommended that as a general rule of thumb one or a combination of these rejuvenation techniques should be performed when the system infiltration rates are below 1.5 inches per hour to maintain the infiltration capability of pervious concrete pavements

    Zest, Character Education, and the Common Good

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    Cultural change can bring changes in how society defines character. This essay examines one recent example of this change through examining how the trait known as zest may have come to be included in recent character education programs. The essay concludes by examining implications for Christian educators. It outlines an approach to thinking critically about character education, suggests an emphasis on traits that support God’s intentions for communal life, and offers examples of teaching practices that may help form hearts not just behaviors

    The chondro-osseous continuum: is it possible to unlock the potential assigned within?

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    Endochondral ossification (EO), by which long bones of the axial skeleton form, is a tightly regulated process involving chondrocyte maturation with successive stages of proliferation, maturation, and hypertrophy, accompanied by cartilage matrix synthesis, calcification, and angiogenesis, followed by osteoblast-mediated ossification. This developmental sequence reappears during fracture repair and in osteoarthritic etiopathology. These similarities suggest that EO, and the cells involved, are of great clinical importance for bone regeneration as it could provide novel targeted approaches to increase specific signaling to promote fracture healing, and if regulated appropriately in the treatment of osteoarthritis. The long-held accepted dogma states that hypertrophic chondrocytes are terminally differentiated and will eventually undergo apoptosis. In this mini review, we will explore recent evidence from experiments that revisit the idea that hypertrophic chondrocytes have pluripotent capacity and may instead transdifferentiate into a specific sub-population of osteoblast cells. There are multiple lines of evidence, including our own, showing that local, selective alterations in cartilage extracellular matrix (ECM) remodeling also indelibly alter bone quality. This would be consistent with the hypothesis that osteoblast behavior in long bones is regulated by a combination of their lineage origins and the epigenetic effects of chondrocyte-derived ECM which they encounter during their recruitment. Further exploration of these processes could help to unlock potential novel targets for bone repair and regeneration and in the treatment of osteoarthritis

    Rightsizing Technical Services: Practical Adaptations for Rapidly Evolving Libraries

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    After years of downsizing physical collections and upsizing electronic collections, the traditional technical services areas at Duquesne University’s Gumberg Library reinvented and streamlined workflows and job responsibilities. As traditional technical services functions changed or faded away, duties in support of access and management of both electronic resources and unique special collections continued to grow and change at a rapid pace. Duties that supported physical collections had to be transitioned to the access and management of electronic resources and unique digitized content. To make these electronic collections accessible, new systems and other emerging technologies were investigated, mastered, and integrated with existing systems, such as EBSCO Discovery Service (EDS); Sierra, the integrated library system (ILS); ArchivesSpace, the open-source archives information management application; CONTENTdm, the digital assess management software; and LibInsight, the library analytics tool, to mention a few. Unlike the physical collections, we found that the electronic resource life cycle required continuous monitoring. Additionally, turnover that occurred during COVID-19 increased opportunities to reevaluate positions and responsibilities. Throughout this process, we discovered that our technical services department was not dissolving but evolving

    Peroxisome Proliferator-Activated Receptor-γ Promotes Adipogenic Changes in Growth Plate Chondrocytes In Vitro

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    Chondrocytes and adipocytes are two differentiated cell types which are both derived from mesenchymal cells. The purpose of this study was to investigate whether peroxisome proliferator-activated receptor-γ (PPARγ), a transcription factor involved in lineage determination during adipogenesis, is able to induce adipogenic differentiation in growth plate chondrocytes. Isolated epiphyseal chondrocytes were infected with a PPARγ adenovirus or treated with the PPARγ agonist ciglitazone. Both of these treatments resulted in lipid droplet accumulation and expression of the adipogenic markers aP2, lipoprotein lipase, and adipsin in chondrocytes. Proteoglycan matrix synthesis was decreased in the PPARγ-infected cells, as was the expression of the chondrogenic genes Col2a1 and aggrecan. Growth plate cells transfected with a PPARγ expression plasmid under the control of the collagen α1(II) promoter also demonstrated a similar adipogenic changes. Terminal differentiation of growth plate chondrocytes induced by thyroid hormone was also inhibited by overexpression of PPARγ and ciglitazone treatment, with decreased expression of alkaline phosphatase and Runx2/Cbfa1 genes. These in vitro data suggest that PPARγ is able to promote adipogenic differentiation in growth plate chondrocytes, while negatively regulating chondrogenic differentiation and terminal differentiation

    Thyroid Hormone-Mediated Growth and Differentiation of Growth Plate Chondrocytes Involves IGF-1 Modulation of β-Catenin Signaling

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    Thyroid hormone regulates terminal differentiation of growth plate chondrocytes in part through modulation of the Wnt/β-catenin signaling pathway. Insulin-like growth factor 1 (IGF-1) has been described as a stabilizer of β-catenin, and thyroid hormone is a known stimulator of IGF-1 receptor expression. The purpose of this study was to test the hypothesis that IGF-1 signaling is involved in the interaction between the thyroid hormone and the Wnt/β-catenin signaling pathways in regulating growth plate chondrocyte proliferation and differentiation. The results show that IGF-1 and the IGF- receptor (IGF1R) stimulate Wnt-4 expression and β-catenin activation in growth plate chondrocytes. The positive effects of IGF-1/IGF1R on chondrocyte proliferation and terminal differentiation are partially inhibited by the Wnt antagonists sFRP3 and Dkk1. T3 activates IGF-1/IGF1R signaling and IGF-1-dependent PI3K/Akt/GSK-3β signaling in growth plate chondrocytes undergoing proliferation and differentiation to prehypertrophy. T3-mediated Wnt-4 expression, β-catenin activation, cell proliferation, and terminal differentiation of growth plate chondrocytes are partially prevented by the IGF1R inhibitor picropodophyllin as well as by the PI3K/Akt signaling inhibitors LY294002 and Akti1/2. These data indicate that the interactions between thyroid hormone and β-catenin signaling in regulating growth plate chondrocyte proliferation and terminal differentiation are modulated by IGF-1/IGF1R signaling through both the Wnt and PI3K/Akt signaling pathways. While chondrocyte proliferation may be triggered by the IGF-1/IGF1R-mediated PI3K/Akt/GSK3β pathway, cell hypertrophy is likely due to activation of Wnt/β-catenin signaling, which is at least in part initiated by IGF-1 signaling or the IGF-1-activated PI3K/Akt signaling pathway. © 2010 American Society for Bone and Mineral Research
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