Frederick Banting realized that this procedure would destroy the trypsin-secreting cells but not the insulin. Once the trypsin-secreting cells had died, insulin could be extracted from the islets of Langerhans. Banting discussed this approach with J. J. R. Macleod, Professor of Physiology at the University of Toronto. Macleod provided experimental facilities and the assistance of one of his students, Charles Best. Banting and Best, with the assistance of biochemist James Collip, began the production of insulin by this means. As the experiments proceeded, the required quantities could no longer be obtained by performing surgery on living dogs. In November 1921, Banting hit
Highest and best use functional obsolescence. Further, there are three potential actions that can be undertaken regarding the existing improvements: Retention of the existing improvements, modification of the improvements or the development scheme of the site, or demolition and removal of the improvements. For example, house A in an area zoned for residential use may have a highest and best use as vacant and a highest and best use as improved that are both residential. A similar house B in a commercially zoned area may have a "highest and best use as vacant" as development to a commercial development, and the "highest and best