Ant Alarm Pheromone Activity: Correlation with Molecular Shape by Scanning Computer

The ant Iridomyrmex pruinosus utilizes 2-heptanone as an alarm pheromone. The activities of 49 ketones and 35 nonketones as alarm pheromones for this species were determined. The molecular shapes of these compounds were assessed by submitting silhouette photographs of their molecular models to a pattern recognition machine. A highly significant correlation exists between molecular shape and alarm activity.

Self modulating, derivative optical spectroscopy. Part II: experimental

The present paper follows a previous one that dealt with the theoretical principles of a self modulating derivative optical spectrometer (SMODOS). In this paper the complete description is given of a prototype of such an instrument, namely, of its optical as well as electronic components. The project criteria are thoroughly discussed, and some examples of performance that demonstrate the power of the method are presented.