Explains the operation of five relative humidity sensors: psychrometer, hair hygrometer, resistance hygrometer, capacitance hygrometer, and resistance-capacitance hygrometer. Outlines the theory behind the electronic sensors and gives computer interfacing information. Lists sensor responses for calibration. (MVL)

Discusses a laboratory technique of enzyme purification by affinity chromatography as part of an undergraduate biochemical methodology course. Provides preparation details of the rat muscle homogenate and reagents. Proposes column requirements and assaying information. (MVL)

Describes a laboratory technique for quantitative analysis of caffeine by an isotopic dilution method for coupled gas chromatography-mass spectroscopy. Discusses caffeine analysis and experimental methodology. Lists sample caffeine concentrations found in common products. (MVL)

Presents a case study of the teaching practices of a biology teacher in Western Australia. Identifies practices considered exemplary for analysis by biology teachers and teacher educators. Discusses the methodology of the study and the qualities of exemplary teaching. (CW)

Presents an overview of 15 laboratory exercises used in an experimental ecology laboratory. Stresses that these exercises require no field work by students and are geared toward testing hypotheses. Suggests the use of these exercises in high school as well as college. (CW)

Described are the purposes, laboratory set-ups, and procedures of four classroom experiments: ultrasound speedometer; vibrating-bar depth gauge; folding three-dimensional model of equipotential surfaces; and a simple optical system for the reconstruction of images from computer-generated holograms. Diagrams and pictures are provided. (YP)

Deterministic chaos which involves orderly motion is discussed. Presented is the history of chaos and two tests for chaos. Practical applications and predictions of the long-term significance of chaos research are discussed. (KR)

Existing federal government policies and systems to protect against scientific misconduct in government-supported research projects are described, and additional considerations not covered in federal policy are enumerated. Misconduct inquiries and review procedures are outlined. Applicant and institutional responsibility and the role of prevention…

Identifies specific instruction difficulties, potential problems, solutions, and activities for successful use of microscopes in the classroom. Procedures are outlined for guiding students in creating their own slides with monocotyledon and dicotyledon stems, fern spores, stomata, lichens, and red onions. (MCO)

Review of the use of preclinical curricular time for laboratory exercises at the Case Western Reserve University (Ohio) medical school 1955-89 found a 92 percent decrease in hours devoted to animal and human physiology. Advantages of inclusion of such exercises are seen to outweigh disadvantages, and efforts to revitalize them are recommended.…

The directions and diagrams for making a reflecting telescope and a refracting telescope are presented. These telescopes can be made by students out of plumbing parts and easily obtainable, inexpensive, optical components. (KR)

A tissue culture experiment that does not require elaborate equipment and that can be used to teach sterile technique, the principles of animal cell line maintenance, and the concept of cell growth curves is described. The differences between cancerous and normal cells can be highlighted. The procedure is included. (KR)

Activities that use dandelions to show the phenomena of geotropism and autotropism are described. Directions for collecting the stalks and observing the gravitropic response are included. The topics of lag time and bending rates, autotropism, growth rate changes, presentation time, and gravity detection are discussed. (KR)

Provided is an outline of laboratory activities involving a full year of student investigations of natural-resource ecology and an example of an activity, "Home Range Analysis." Objectives, background information, key vocabulary, skills, materials, procedures, extension activities, and evaluation of this three-lesson activity are discussed. (CW)

Included are three demonstrations that include the phase change of ice when under pressure, viscoelasticity and colloid systems, and flame tests for metal ions. The materials, procedures, probable results, and applications to real life situations are included. (KR)