Epilogue

Factors that may have been decisive in turning Rancho Santa Ana Botanic Garden into a successful establishment of botanical teaching and a garden devoted to the conservation and showcasing of the native California flora are put forward. In addition to the enthusiasm and tenacity of its founder, Susanna Bixby Bryant, inspiration and advice came from several other key figures, notably Carl Brandt Wolf, Ernest Braunton, Willis Linn Jepson, and Theodore Payne

Time Series Analysis in Flight Flutter Testing at the Air Force Flight Test Center: Concepts and Results

The Air Force Flight Test Center (AFFTC) flight flutter facility is described. Concepts of using a minicomputer-based time series analyzer and a modal analysis software package for flight flutter testing are examined. The results of several evaluations of the software package are given. The reasons for employing a minimum phase concept in analyzing response only signals are discussed. The use of a Laplace algorithm is shown to be effective for the modal analysis of time histories in flutter testing. Sample results from models and flight tests are provided. The limitations inherent in time series analysis methods are discussed, and the need for effective noise reduction techniques is noted. The use of digital time series analysis techniques in flutter testing is shown to be fast, accurate, and cost effective

The Years 1960–1977

In the years 1960–1977, Rancho Santa Ana Botanic Garden fully embraces its role as teaching institution and as advocate and guardian of the native California flora. Expansion of the living collection, landscaping of the grounds, public education, herbarium and library activities, and publication output are detailed. To accommodate a growing number of graduate students, the faculty—consisting of Richard K. Benjamin, Sherwin Carlquist, and Lee. W. Lenz—is joined by Peter H. Raven, Ronald Scogin, John P. Simon, and Robert F. Thorne

Seed Dispersal in Yucca Brevifolia (Agavaceae)-Present and Past, With Consideration of the Future of the Species

Earlier descriptions of the fruit of Yucca brevifolia are reviewed. It is here shown that the fruit is a fleshy, sugar-rich berry that later becomes a hard, dry, spongy body. At no time are seeds released from the fruits without the exertion of an outside force. Various animals that might release seeds from the dry fruits are considered, as is wind that may disperse entire fruits. The question is introduced as to why Y. brevifolia Engelm. would expend large amounts of energy and resources to create a product for which there is no market. The appeal that the fruits may have had for now extinct megaherbivores is addressed. Finally, the possible future of the species is considered

Second constant of motion for two-dimensional positronium in a magnetic field

Recent numerical work indicates that the classical motion of positronium in a constant magnetic field does not exhibit chaotic behavior if the system is confined to two dimensions. One would therefore expect this system to possess a second constant of the motion in addition to the total energy. In this paper we construct a generalization of the Laplace-Runge-Lenz vector and show that a component of this vector is a constant of the motion.Comment: 4 pages, no figure