The forces and torques experienced by the spine are examined to understand, and possibly avoid, low back pain. The structure, degrees of freedom, forces and torques when lifting objects, an experimental study, and other factors affecting the back are discussed. (KR)

Hands-on activities that use water, candles, powders found in the kitchen, and bubbles to provide a lesson on chemical change are presented. Directions for conducting the activities and a list of needed supplies are provided. (KR)

An activity that introduces students to the correct handling of bacterial recombinants, antibiotic sensitivity testing, insertional inactivation, plasmid DNA isolation, restriction endonuclease digestion, agarose gel electrophoresis, Southern blotting, hybridization, and autoradiography is presented. A list of needed materials, procedures, safety…

Presented is an approach to the study of nutrient cycling in the school laboratory. Discussed are obtaining, processing, and incubating samples; extraction of ions from soil; procedures for nitrate and ammonium analysis; data analysis; an example of results; and other aspects of the nitrogen cycle. (CW)

Describes problems in teaching problem solving and summarizes research in this area. Presents Guided Design or Guided Decision Making as a problem-solving approach in which groups of students work their way through a model of the problem-solving process as they wrestle with a discipline-specific situation. (PR)

Describes the preparation and importance of a project where junior high school students stenciled "No Dumping! Flows to the Bay!" on storm drains in the area of their school. (PR)

Presents and discusses a contract to encourage students to get involved in cleaning up the environment. (PR)

A middle school principal describes her school's exemplary hands-on science program. (PR)

Presents activities in which students construct simple crystal radio sets and amplifiers out of diodes, transistors, and integrated circuits. Provides conceptual background, materials needed, instructions, diagrams, and classroom applications. (MDH)

Provides a student worksheet and set-up instructions for a science experiment to demonstrate the concept of density. Students are asked to explain the phenomenon in which a liquid of lower density placed in the bottom of two vertical flasks flows up to replace the liquid of higher density in the upper flask. (MDH)

Describes an activity where students find the locations and elevations of their homes, school, favorite parks and lakes, and other significant places as they learn topographic skills and unique features of the community. (PR)

Presents an activity to help students understand the precepts of the Hardy-Weinberg principle and simultaneously permit observation of a model of evolution through natural selection in a nonthreatening setting. (PR)

Describes combining the simple activity of collecting monthly student height measurements with the technology of using a computer spreadsheet for a year-long activity that teaches measurement and data manipulation. (PR)

Presents an activity that demonstrates the physical and chemical changes that occur during the operation of a wet cell battery as it produces an electrical current. Provides instructions for the lesson. (MDH)

Describes a writing-across-the-curriculum course and its application to science courses. Shows how different kinds of writing instruction affect students' learning as well as students' attitudes, understandings, and approach to "writing to learn." (PR)