Table 1. Values of the dimensionless parameters.

Parameter	Non-dim value	Description
Production Rates
ρF	243.1	max production rate of F
ρR	0.0145	Constant production rate of R
ν	1.361	max C-dependent rate of R production
	12 · ρR	max F-dependent rate of B production
ρB1	0.063	Constant production rate of B in the “handplate”
ρB2	3 · ρB1	Constant production rate of B in the lower stalk (H1)
Diffusion Coefficients
DB	2.7	BMP diffusion constant
DR	0.01 · DB	Receptor diffusion constant
Decay constants
δR	0.135	Receptor decay constant
δB	0.15 · δr	BMP decay constant
δC	ν/3	Receptor-ligand complex decay constant
Regulation
n	2	Hill coefficient
κ1	0.06588	Hill constant for BMP → FGF positive feedback
κ2	very large	Hill constant for BMP ” FGF negative feedback
Domain Size
RRef	7.74	Reference radius