negative reinforcement

He says he has yet to experience any negative feedback from the galaxy of Whovians.

Before Louis could answer in the negative, he heard voices in the adjoining garden.

The great majority belong to the colon bacillus group, and are negative to Gram's method of staining.

This is a minute, slender rod, which lies within and between the pus-corpuscles (Fig. 125), and is negative to Gram's stain.

The organism is a short, thick diplobacillus, is frequently intracellular, and is Gram-negative (Fig. 126).

The press censorship is a negative evil in London; in Cairo there is no doubt it is positive.