1,341 research outputs found
The challenge of changing deeply-held student beliefs about the relativity of simultaneity
Previous research indicates that after standard instruction students at all
academic levels often construct a conceptual framework in which the ideas of
absolute simultaneity and the relativity of simultaneity co-exist. This article
describes the development and assessment of instructional materials intended to
improve student understanding of the concept of time in special relativity, the
relativity of simultaneity, and the role of observers in inertial reference
frames. Results from pretests and post-tests are presented to demonstrate the
effect of the curriculum in helping students deepen their understanding of
these topics. Excerpts from taped interviews and classroom interactions help
illustrate the intense cognitive conflict that students encounter as they are
led to confront the incompatibility of their deeply-held beliefs about
simultaneity with the results of special relativity.Comment: 17 pages, 6 figures, 2 tables, 27 references; Accepted for
publication in Physics Education Research Section, American Journal of
Physics (2001
Integrated land and water management for food and environmental security
Water resource management / Food security / Environmental effects / Soil degradation / Water pollution / Watersheds / Urbanization / Public policy / Water quality / Ecosystems / Land resources / Water scarcity / Developing countries / Poverty / Households / Food supply / Economic aspects / Social aspects / Groundwater depletion / Salinity / Wetlands / Investment / Land use / Water use / Training needs assessment / Research priorities
Overcoming Innocents’ Naiveté: Pre‐interrogation Decision‐making Among Innocent Suspects
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/133623/1/bsl2247.pd
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Using Theory to Develop Healthy Choices in Motion, a Comprehensive, Experiential Physical Activity Curriculum.
Background: Research has shown that engaging in regular physical activity supports physiologic, metabolic, and immunologic processes, as well as quality of life. However, few youth in the United States meet the U.S. Department of Health and Human Services recommendation of 60 min of moderate-to-vigorous physical activity every day. School-based programs can be an effective avenue for engaging youth in physical activity, particularly when the design of the health education is based on theory, research, and practice. The purpose of this study was to design, implement, and evaluate a theory-driven physical activity curriculum for the Shaping Healthy Choices Program (SHCP) using a systematic approach. Methods: The experiential, inquiry-based physical activity curriculum, Healthy Choices in Motion (HCIM), was developed with an optional technology enhancement using Backward Design. A questionnaire to assess the curriculum's effect on physical activity knowledge was developed and assessed for content validity, internal consistency (α = 0.84), and test-retest reliability (r = 0.73). The curriculum was piloted in two phases among upper elementary-aged youth: to ensure the learning goals were met (Pilot I) and to determine the curriculum's impact on physical activity knowledge, behavior, and self-efficacy (Pilot II). Pilot II was implemented among eight 4th and 5th-grade classrooms participating in the UC CalFresh Nutrition Education Program: (1) Comparison (no intervention) (n = 25); (2) SHCP only (n = 22); (3) SHCP + HCIM (n = 42); (4) SHCP + HCIM with technology enhancement (n = 47). Analyses included unadjusted ANOVA and Bonferroni for multiple comparisons and paired t-test (p < 0.05). Results: Through the use of a methodical design approach, a comprehensive physical activity curriculum, called HCIM, was developed. Youth participating in HCIM improved physical activity knowledge compared to youth receiving no intervention (+2.8 points, p = 0.009) and youth only in the SHCP (+3.0 points, p = 0.007). Youth participating in HCIM with technology enhancement demonstrated improvements compared to youth only in the SHCP (+2.3 points, p = 0.05). Conclusion: Improvements in physical activity knowledge in youth participating in HCIM may contribute to improvements in physical activity and should be further explored in conjunction with behavioral measurements
Toll-Like Receptor 7 Agonist Therapy with Imidazoquinoline Enhances Cancer Cell Death and Increases Lymphocytic Infiltration and Proinflammatory Cytokine Production in Established Tumors of a Renal Cell Carcinoma Mouse Model
Imidazoquinolines are synthetic toll-like receptor 7 and 8 agonists and potent dendritic cell activators with established anticancer activity. Here we test the hypothesis that imidazoquinoline has in vivo efficacy within established renal cell carcinoma (RCC) tumors. Immunocompetent mice bearing syngeneic RCC xenografts were treated with imidazoquinoline or placebo at two separate time points. Harvested tumors were assayed by TUNEL/caspase-3/Ki67 immunostains to evaluate cell death/apoptosis/proliferation, and CD3/B220/CD45 immunostains to evaluate T-cell lymphocyte/B-cell lymphocyte/pan-leukocyte tumor infiltration. ELISA measurement of tumor and serum levels of proinflammatory cytokines, IL-6 and MCP-1, was performed. A single imidazoquinoline dose significantly decreased RCC tumor growth by 50% and repeat dosing compounded the effect, without observed weight loss or other toxicity. Tumor immunostaining revealed significant increases in cell death and apoptosis without changes in cell proliferation, supporting induction of apoptosis as the primary mechanism of tumor growth suppression. Imidazoquinoline treatment also significantly enhanced peritumoral aggregation and intratumoral infiltration by T-cell lymphocytes, while increasing intratumoral (but not serum) levels of proinflammatory cytokines. In conclusion, imidazoquinoline treatment enhances T-cell lymphocyte infiltration and proinflammatory cytokine production within established mouse RCC tumors, while suppressing tumor growth via induction of cancer cell apoptosis. These findings support a therapeutic role for imidazoquinoline in RCC
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