Tune shift with amplitude of the system. When the tune reaches resonant values, it can be unstable, and thus a tune-shift with amplitude can limit the stability region, or dynamic aperture. In classical mechanics, a simple example of a system with tune shift with amplitude is a pendulum. In accelerator physics, both the transverse and the longitudinal dynamics show tune shift with amplitude. A simple model of the transverse dynamics is of an oscillator with a single sextupole, it is referred to as the Hénon map. Another model for this case is the Standard Map. An important example is the typical case of distributed
Large irregular activity EEG, the non-rhythmic pattern of large irregular activity,(LIA). LIA has the predominant pattern of large amplitude slow waves that contain some fluctuations of sharp spikes (sharp waves) of 50–100 ms duration. The predominant frequency of LIA is slower than that of theta waves. LIA is often accompanied by ripples in the pyramidal cell layer. When the neural circuitry of the hippocampus is activated it tends to oscillate at theta frequencies. It has also been noted that a fair proportion of hippocampal neurons fire in a correlation with sharp wave activity. The theta state is thought to be involved in the