Summarizes the Darwin theory of x-ray diffraction in thin crystals or crystals with a mosaic texture and its modified application to crystals with three-dimensional electrostatic dipoles. Indicates that the dynamical theory is brought into its present relevance by the improvement of single crystal growth techniques. (CC)

Discusses the controversy about the discovery of element 72, involving Urbain's isolation of celtium, Dauvillier's reexamination of celtium samples, and Coster and Hevesy's announcement of the existence of hafnium. Indicates that the Copenhagen workers are finally accredited for the element discovery in their x-ray spectral studies. (CC)

Contained are five questions related to chemistry and ecology. Satisfactory answers to these five questions are included. (RH)

A need for quality in instructional materials is cited, with the future role of teacher seen as a learning coach, an organizer, manager and creator of learning experiences. (Author/JB)

An account of what equipment was acquired in order to establish a resource center at Bilston College of Further Education. (HB)

A discussion of the facilities and services provided by the Media-Centre Steinfurt located in Burgsteinfurt, Germany. (HB)

Article describes a California curriculum laboratory where teachers can make teaching aids to suit their immediate classroom requirements. (GB)

Describes the polywater exhibit at the Worcester Science Center in Massachusetts. Curiosity and interest are stimulated in young people by allowing them to handle the materials in the exhibit and by providing them with instructions for making polywater. (JR)

Presents sample laboratory activities designed for use in astronomy teaching, including naked eye observations, instrument construction, student projects, and cloudy weather activities. Appended are bibliographies of journal articles and reference books and lists of films, laboratory manuals, and distributors of apparatus and teaching aids. (CC)

Laboratories for Learning Resourses, instead of replacing or competing with the medical library, should provide a learning environment for medical students, with books, laboratory-lecture presentations, slide-sound programs, films, videotapes, computer models and programs, museum specimens and charts. (Author/PG)

RESA (Regional Education Service Agency), a confederation of several school districts, has been adopted by the Appalachian Regional Commission as a method of pooling resources. (NQ)

How to determine whether the cost of differentiated staffing is proportionate to the benefits that may be realized. (Author)

Specific suggestions for strengthening the curricula and the types of programs in operation dealing with Chicano Studies are offered. (NQ)