An indicator mixture that allows pH measurement over a broader range of pH or to a higher accuracy than available using conventional spectroscopic techniques. Thus, immunogenic peptides are selected from promiscuous Th epitopes and synthesized together with self antigenic peptide sequences fused with or without end to end spacer peptide interconnections. Alternatively or additionally, methods for reversibly affecting memory function comprise inhibiting neurons of the amygdala andor neurons of the cingulate cortex. 0 gm2, both inclusive, per surface. A great variety of other features and arrangements are also detailed.