What's the difference between asseveration and asseverative?

Asseveration

Definition:

(n.) The act of asseverating, or that which is asseverated; positive affirmation or assertion; solemn declaration.

Example Sentences:

(1) Treatment choice and effectiveness in prosthodontics has largely depended on educated anecdote and asseveration.
(2) Finally, on the basis of the information presented, several conclusions are reached which make it possible to asseverate that the teaching of preventive and social medicine is not given the importance it merits, in the study plan of any medical school in the country.
(3) In order to confirm or to discard this asseveration an in-vitro lymphocyte transformation test was realized, with the venous peripherical blood of each patient, using the greater determinative of penicillin: the peniciloil.