For about four decades now, a course in receptor pharmacology has been given at University College
London for undergraduate students in their final year of study for the Bachelor of Science degree
in pharmacology. More recently, the course has also been taken by students reading for the Bachelor
of Science degree in medicinal chemistry. The students following the course have relied for their
reading upon a variety of sources, including original papers, reviews, and various textbooks, but
no single text brought together the material included in the course.
In the first edition of this book, I claimed that humanity could be divided into three
groups: (1) those who conduct their own research studies, (2) those who do not formally
engage in the research process but nonetheless encounter the results of others’
investigations, and (3) those who are neither “makers” nor “consumers” of research
claims. Now, nearly 40 years since I made that statement, I still believe that every
person on the face of the Earth can be classified into one of those three groups.
Time-driven systems such as living organisms, ecological systems and world population have
long been modeled and analyzed through differential equations. Man-made technological
environments such as computer, transportation and telecommunication networks or
manufacturing and logistics systems represent systems whose behaviors are governed by events
occurring asynchronously over time.