A higher skill may augment another one in Diaspora by +1 when they work together. In other words, you get the +1 only if your Stamina is or higher than your Weapons skill.
Diaspora p. 10
skill a is amplified by skill b
This indicates that Skill A is used for the check. If Skill B exceeds Skill A, then an additional +1 is granted. For example, a Brawling check amplified by Strength (as might happen if a character tries to throw a large table during a fight) with Brawling 2 and Strength 5 would be checked at 3 (Brawling rank +1) + 4dF.