Trust, UIDs, signing & revoking

[Phil Brooke]

Suppose I have a key with several UIDs.  I now revoke one of the UIDs
(suppose that email address is no longer valid).

Do the signatures from other people on that revoked UID still count
towards any trust calculations?  (Assuming that they've only signed that
UID, and no others.)

I'm thinking about the problem where email addresses tend to be rather
short-lived.  Should a UID with just the name be added for the purpose of
collecting signatures?

(I've had a look in the various bits of documentation, and I'm still a bit
unsure about this.)

TIA,

Phil.

(Please Cc replies to me; I don't always see all messages on the lists.)