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Lynn S. Fuchs Douglas Fuchs Kurstin N. Hollenbeck 《Learning disabilities research & practice》2007,22(1):13-24
Responsiveness to intervention (RTI) is an innovative approach to the identification of learning disabilities (LD). The central assumption is that RTI can differentiate between two explanations for low achievement: poor instruction versus disability. If the child responds poorly to validated instruction, then the assessment eliminates instructional quality as a viable explanation for poor academic growth and instead provides evidence of a disability. For children who do respond nicely, RTI serves a critical prevention function. Most of RTI research has been focused on early reading. In this article, we describe two ongoing programs of research on RTI in the area of mathematics: one on a comprehensive mathematics curriculum at first grade and the other focused on word problems at third grade. For each research program, we describe the sample, explain how students are identified as at risk for mathematics disability, provide an overview of the interventions to which responsiveness is gauged, and describe some results to date. 相似文献
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Braided composite materials for the production of lightweight, high rigidity golf shafts 总被引:1,自引:1,他引:0
Braiding is not currently used in the production of golf shafts. The objective of this work was to develop, through a modelling
process consisting of altering lamina sequence, a golf shaft, using braided laminas, which would have mass, stiffness and
torque comparable to commercially available composite and steel shafts. A 2D conical braided composite model was previously
developed and validated to predict elastic constants of braided closed meshed structures. Energy methods were used to calculate
the stiffness and torque of shafts using prescribed industry approaches. Shaft mass was calculated based on geometry and density
of constitutent materials. Modelled shafts had both braided and unidirectional layers and compared favourably with or were
better than commercially available composite and steel shafts in terms of deflection force and twist angle; they had the same
weight as composite shafts but were much lighter than steel shafts. If these findings are verified, braided composites would
be a viable and effective approach to the design of future golf shafts. 相似文献
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Endurance running performance in athletes with asthma 总被引:1,自引:0,他引:1
Laboratory assessment was made during maximal and submaximal exercise on 16 endurance trained male runners with asthma (aged 35 +/- 9 years) (mean +/- S.D.). Eleven of these asthmatic athletes had recent performance times over a half-marathon, which were examined in light of the results from the laboratory tests. The maximum oxygen uptake (VO2max) of the group was 61.8 +/- 6.3 ml kg-1 min-1 and the maximum ventilation (VEmax) was 138.7 +/- 24.7 l min-1. These maximum cardio-respiratory responses to exercise were positively correlated to the degree of airflow obstruction, defined as the forced expiratory volume in 1 s (expressed as a percentage of predicted normal). The half-marathon performance times of 11 of the athletes ranged from those of recreational to elite runners (82.4 +/- 8.8 min, range 69-94). Race pace was correlated with VO2max (r = 0.863, P less than 0.01) but the highest correlation was with the running velocity at a blood lactate concentration of 2 mmol l-1 (r = 0.971, P less than 0.01). The asthmatic athletes utilized 82 +/- 4% VO2max during the half-marathon, which was correlated with the %VO2max at 2 mmol l-1 blood lactate (r = 0.817, P less than 0.01). The results of this study suggest that athletes with mild to moderate asthma can possess high VO2max values and can develop a high degree of endurance fitness, as defined by their ability to sustain a high percentage of VO2max over an endurance race. In athletes with more severe airflow obstruction, the maximum ventilation rate may be reduced and so VO2max may be impaired. The athletes in the present study have adapted to this limitation by being able to sustain a higher %VO2max before the accumulation of blood lactate, which is an advantage during an endurance race. Therefore, with appropriate training and medication, asthmatics can successfully participate in endurance running at a competitive level. 相似文献
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