It may just be my perception but it seems to me that the verb assumir is or embodies a Brazilian cultural value. People are always talking about the importance of taking responsibility, taking charge, assessing, declaring and facing the reality of a situation.
It seems to me that much academic advice goes in the opposite direction. It is about what not to do, what to avoid, where to dodge, and how to avoid conflict. I think assumir is the better strategy, as it gives you far more power.
Axé.
coldhearted scientist وداد 
My problem is that I never seem like an authority figure. I always end up behind the scenes.
I need to do this, because my hide-and-avoid strategy is not working.
I am always trying not to seem threatening, so I end up not being seen as an authority figure. I am going to stop this.
Hide-and-avoid really is what they teach us to do in academia, I think, and it does not work.