9/17/03
14
Additional Explanation of
Chemotaxis Term
¥
The termite flow into a region is the negative
divergence of the flux through it
Ð
Ð
„
×
J
¥
The flux is proportional to the pheromone gradient
Ð
J
µ
„
H
¥
The flux is proportional to the number of moving
termites
¥
J
µ
C
¥
Hence, Ð
g
„
×
J
=
Ð
g
„
×
(
C
„
H
)
If
V
is the velocity of a flow, then div
V
is the outflow rate per unit volume
(Boas 271-3; SOBS 114-6)