3 research outputs found

    Implementing Curriculum Based Assessment: A Model to Identify Children who are Academically at Risk

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    The purpose of the project was to develop a curriculum based assessment model using Custer Elementary School\u27s prescribed curriculum that would identify academically at-risk students and provide intervention services. A curriculum based assessment model was developed based upon the major assumptions that measurement of pupil progress should: (1) be directly related to the curriculum the student is taught; (2) be repeated frequently; and (3) guide instructional planning for the student. A review of the related literature indicated curriculum based assessment offers an alternative approach for continuously measuring student achievement of proficiency in basic school skills. Implications for the implementation of a curriculum based assessment format are discussed

    Combinatorial Guidance by CCR7 Ligands for T Lymphocytes Migration in Co-Existing Chemokine Fields

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    Chemokines mediate the trafficking and positioning of lymphocytes in lymphoid tissues that is crucial for immune surveillance and immune responses. In particular, a CCR7 ligand, CCL21, plays important roles in recruiting T cells to secondary lymphoid tissues (SLT). Furthermore, CCL21 together with another CCR7 ligand, CCL19, direct the navigation and compartmentation of T cells within SLT. However, the distinct roles of these two chemokines for regulating cell trafficking and positioning are not clear. In this study, we explore the effect of co-existing CCL19 and CCL21 concentration fields on guiding T cell migration. Using microfluidic devices that can configure single and superimposed chemokine fields we show that under physiological gradient conditions, human peripheral blood T cells chemotax to CCL21 but not CCL19. Furthermore, T cells migrate away from the CCL19 gradient in a uniform background of CCL21. This repulsive migratory response is predicted by mathematical modeling based on the competition of CCL19 and CCL21 for CCR7 signaling and the differential ability of the two chemokines for desensitizing CCR7. These results suggest a new combinatorial guiding mechanism by CCL19 and CCL21 for the migration and trafficking of CCR7 expressing leukocytes
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