  We present molecular-line observations toward the dense core in L483 and its
bipolar outflow powered by the Class 0 object IRAS 18148-0440. CO (carbon
monoxide) maps show that the outflow is well collimated and asymmetric, and
that its gas is warmer than the surrounding cloud by at least a factor of 2.
H2CO (formaldehyde) lines toward the outflow show prominent high-velocity wings
and evidence for an H2CO abundance enhancement of a factor of 20. At ambient
velocities, these lines show strong self-absorption and a brighter blue peak, a
characteristic signature of inward motions. Finally, and in contrast with the
outflows from other Class 0 objects, the CH3OH (methanol) lines in L483 do not
show high velocity wings, and no evidence for abundance enhancement is found in
this molecule or in SiO (silicon monoxide). Comparing the physical and chemical
properties of the outflow in L483 with those of other outflows from Class 0 and
Class I sources, we find that the L483 outflow is somewhat intermediate between
these types. This suggests that the L483 central source has already started its
transition between Class 0 and Class I, and that its mixed properties
illustrate how this transition occurs.
