Delta formulation/structure

An alternative to the HRG formulation is the Delta formulation [201]. This mainly differs in that the connection between the relations (called streams in Delta) is determined by a chart. An example of a Delta structure is shown in Figure 4.4. Here, each stream/relation is a hst, but navigation is performed by going to the edge of the item and ascending or descending through the chart. The Delta system is somewhat simpler... 

About 15 years ago, we formulated some tentative rules for cannabimimetic structure-activity relationships (SAR) (Edery et al. 1971 Mecboulam and Edery 1973). These rules were based on work our group had done since 1964, when we isolated and elucidated the structure of delta-1-tetrahydrocannabinol (delta-1-THC) (Gaoni and Mechoulam 1964), as well as on research by numerous other groups. Most of our work was done with rhesus monkeys much of the work by the other groups was done with either rodents or dogs. However, gratifyingly, the results obtained with different species were qualitatively comparable. 

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