Aboral slow-wave frequency gradient

The intestinal slow-wave frequency falls monotonically aboral, reproducing the duodenum-to-ileum gradient. One gastric-anchored clock (K_TIME=2400 cpm per model-Hz) converts each segment's FitzHugh–Nagumo frequency to cycles per minute, predicting duodenum 11.1 cpm and ileum 7.5 cpm with zero intestinal tuning. The gradient direction is forced [V]; absolute rates inherit the cited clock [L].

A linearly growing recovery constant along the gut yields a monotone falling slow-wave gradient. The single gastric clock predicts duodenum 11.1 cpm (cited ~12) and ileum 7.5 cpm (cited ~8) with no intestinal tuning. The gradient shape is [V]; the absolute rates inherit the cited clock [L].

The intestinal slow-wave frequency falls monotonically in the aboral direction, reproducing the physiological duodenum-to-ileum gradient. A single segment property — the FitzHugh–Nagumo recovery constant τ_s growing linearly along the gut — produces the entire descending profile.

One gastric-anchored clock converts each segment's intrinsic frequency to cycles per minute with zero intestinal tuning, predicting duodenum 11.1 cpm (cited ~12), jejunum 9.0 cpm (cited ~10), and ileum 7.5 cpm (cited ~8). The duodenal prediction lands within 8% of the cited value despite the clock being fixed by the stomach alone.

The gradient direction and shape are forced by the substrate [V]; the absolute rates inherit the cited clock [L]. Monotonic decrease holds across segment counts N ∈ {8,12,16,20} and the full drive sweep, so the falling gradient is a property of the mechanism, not of a particular discretization.