The Visual Mechanisms of Tenebrio Molitor: Changes in the Electro-Retinogram as Function of the Stimulus Duration

The ERG complex of the compound eye of the yellow mealworm bettle Tenebrimolitor (L.) separates into two components with stimulus durations of longer than 100 ms. These are the ‘on’ and the ‘off’ effects. Above stimulus durations of 1 s the positive potential following the ‘on’ is faster and the positive ‘off’ is followed by a small negative one. The latent period of the ‘on’ is independent of the stimulus duration while for stimulus durations of longer than 300 ms the ‘off’ latency is coupled with the end of the stimulus. If measured after the extinction of the stimulus the ‘off’ latency is affected by the stimulus duration. The ‘on’ and ‘off’ amplitudes behave similarly for various stimulus durations. Both originate in the receptor cells. The Bunsen-Roscoe Law of photochemistry holds for stimulus durations of 10-40 ms. For a given intensity, the amplitudes diminished for durations longer than 300 ms

Negative ion spectrometry for detecting nitrated explosives

Ionization procedure is modified to produce mainly negative ions by electron capture. Peaks of negative ions are monitored conventionally. Nitrated organic materials could be identified directly from sample sniff inlet stream by suitably modified mass spectrometer because of unique electronegativity which nitro group imparts to organic material