These Proceedings have been assembled from papers presented at the Conference on Models of Biological Growth and Spread, held at the German Cancer Research Centre Heidelberg and at the Institute of Applied Mathematics of the University of Heidelberg, July 16-21, 1979. The main theme of the conference was the mathematical representation of biolog- ical populations with an underlying spatial structure. An important feature of such populations is that they and/or their individual com- ponents may interact with each other. Such interactions may be due to external disturbances, internal regulatory...

The idea of organizing a symposium on mathematical models in biology came to some colleagues, members of the Accademia dei Lincei, in order to point out the importance of mathematics not only for supplying instruments for the elaboration and the evaluation of experimental data, but also for discussing the possibility of developing mathematical formulations of biological problems. This appeared particularly appropriate for genetics, where mathematical models have been of historical importance. When the organizing work had started, it became clear to us that the classic studies of Vito Volterra...

The mathematical models in this book are concerned with a variety of approaches to the manner in which the clinical radiologic treatment of human neoplasms can be improved. These improvements comprise ways of delivering radiation to the malignan cies so as to create considerable damage to tumor cells while sparing neighboring normal tissues. There is no unique way of dealing with these improvements. Accord ingly, in this book a number of different presentations are given. Each presentation has as its goal some aspect of the improvement, or optimization, of radiotherapy. This book is a...

During the last 30 years, many chemical compounds that are active against tumors have been discovered or developed. At the same time, new methods of testing drugs for cancer therapy have evolved. nefore 1964, drug testing on animal tumors was directed to observation of the incfease in life span of the host after a single dose. A new approach, in which the effects of multiple doses on the proliferation kinetics of the tumor in vivo as well as of cell lines in vitro are investigated, has been outlined by Skipper and his co-workers in a series of papers beginning in 1964 (Skipper, Schabel and...

These notes are an extended version of lectures given in the Symposium on Mathematics and Development arranged by the School of Mathematical Sciences of the University of Khartoum, Sudan, in 1982. The purpose of the notes is to discuss some models for the transmission of tropical infections. This area of mathematical epidemiology has previously received only minor attention by mathematicians, but is now growing in importance. The term "hybrid model" is used to denote a model with both stochastic and deterministic ingredients. We describe how a hybrid model approach can be used to formulate...

These are the proceedings of the Second R. Yorque Workshop on Resource Management which took place in Ashland, Oregon on July 23-25, 1984. The purpose of the workshop is to provide an informal atmosphere for the discussion of resource assessment and management problems. Each participant presented a one hour morning talk; afternoons were reserved for informal chatting. The workshop was successful in stimulating ideas and interaction. The papers by R. Deriso, R. Hilborn and C. Walters all address the same basic issue, so they are lumped together. Other than that, the order to the papers in this...

One of my favorite quotes is from a letter of Charles Darwin (1887): I have long discovered that geologists never read each other's works, and that the only object in writing a book is proof of earnestness, and that you do not form your opinions without undergoing labour of some kind. It is not clear if this private opinion of Darwin was one that he held to be absolutely true, or was one of those opinions that, as with most of us, coincides with our bad days, but is replaced with a more optimistic view on our good days. I hold the sense of the statement to be true in general, but not with...

A conference on "Some Mathematical Problems in Biology" was held at the University of Victoria, Victoria, B. C. , Canada, from May 7 - 10, 1973. The participants and invited speakers were mathematicians interested in problems of a biological nature, and scientists actively engaged in developing mathematical models in biological fields. One aim of the conference was to attempt to assess what the recent rapid growth of mathematical interaction with the biosciences has accomplished and may accomplish in the near future. The conference also aimed to expose the problems of communication bet~",een...

When we consider the main object of forestry, the tree, it immediately becomes clear why experimental population geneticists have been so hesitant in making this object a primary concern of their research. Trees are very long-living organisms with generation intervals frequently exceeding those of their investigators by multiples. They virtually exclude, therefore, application of the classical methods of population genetics since these are based on observing genetic structures over generations. This situation, where the limits set to observation are so severe, particularly requires close...