No signs

No sign of business ethics within the Company, or even the remotest sense of morality

No sign of two neurones connecting together in C.F.'s poor little echoing skull.

No sign of rain. Did I just type this? No sign of rain!!!

No sign of niceness about the guy who would go to the trouble of getting up a ladder to put up a "no signs" sign where not even the most zealous overgrown spotty-teenager-on-stilts-whose-Dad-works-in-a-spray-paint-factory would leave his over-sized initials.
That guy must be busy right now nailing "no naked flame" signs on icebergs drifting off the Arctic ice cap.