Shanta Hattikudur

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This study examined how 4 middle school textbook series (2 skills-based, 2 standards-based) present equal signs. Equal signs were often presented in standard operations-equals-answer contexts (e.g., 3 + 4 = 7) and were rarely presented in non-standard operations on both sides contexts (e.g., 3 + 4 = 5 + 2). They were, however, presented in other nonstandard(More)
The cross-reactivity of crude sonic extracts of six species of mycobacteria was studied by skin tests in mice and guinea pigs immunised with live Mycobacterium tuberculosis strain H37Rv, and in patients with pulmonary tuberculosis. All slowly growing mycobacteria elicited a strong delayed hypersensitivity response, M. vaccae a moderate response and M. phlei(More)
This study investigated whether instruction that involves comparing the equal sign with other relational symbols is more effective at imparting a relational interpretation of the equal sign than instruction about the equal sign alone. Third- and fourth-grade students in a comparing symbols group learned about the greater than, less than, and equal signs and(More)
Students benefit from learning multiple procedures for solving the same or related problems. However, past research on comparison instruction has focused on comparing multiple formal procedures. This study investigated whether the benefits of comparing procedures extend to comparisons that involve informal and formal procedures. We also examined how learner(More)
Given recent findings that test-enhanced learning (TEL) improves students' understanding and retention of material through regular quizzing (e., we incorporated TEL-inspired online quizzing into a cognitive psychology undergraduate lecture course. With the addition of quizzing to the course, class performance improved according to several criteria relative(More)
Swiss white mice were immunized with different mycobacteria and delayed type hypersensitivity (DTH) responses were studied by the foot-pad swelling technique of Gray and Jennings (1955). Extensive cross-reactions in DTH, outside the limits of Runyon's groups were observed. As a general trend slow growing mycobacteria showed greater cross-reactivity with(More)
Antigen participating in cell-mediated immunity was isolated from a sonic extract of Mycobacterium tuberculosis H37Rv. The purified antigen had a mol. wt 150 000-200 000, based upon its Rf in 7.5% polyacrylamide gel in the presence of sodium dodecyl sulphate. In simple agarose gel electrophoresis it had an Rf of 0.85. The protein in its native state was(More)
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