From the Editors. 1

Schuster, D.H. and L. Schuster. Demographic data support a model for cultural change. 3

Heck, P.W. and E.S. Takle. Objective forecasts of solar radiation and temperature. 29

Hammond, E.G. Sylvester Graham: America's first food reformer. 43

Wessel, R.I. District heating decisions in Iowa- non-decision decision making. 63

Gupta, S.C. and K.J. Frey. Selection for vegetative growth rate of oats. 75

Krafsur, E.S. and G. Davidson. Production of semisterile mutants in the Anopheles gambiae s.l. species complex. 85

York, S.L. Fitting human performance data: a comparison of three methods of data smoothing. 99

DiGrino, B.N., C.F. Yoshioka, L.D. Cooney, and B.C. Wilhite. Purpose and practice among clinical therapeutic recreation settings and community based recreation settings serving special populations. 109

Note. 121