Which logical fallacy is used in the text?
I don't trust Professor Harper's findings. Another researcher at her university was caught falsifying data. So, it's likely Professor Harper has, too.

 - straw man: a misrepresentation of an opponent's position that makes it easier to argue against
 - guilt by association: a negative association intended to discredit someone or something
 - circular reasoning: an argument that supports a claim with the claim itself
The text argues that Professor Harper's research is untrustworthy because someone else at her university was caught falsifying data. However, this isn't necessarily true. The practices of one researcher at a university do not necessarily reflect the practices of another researcher at the same university. This illustrates a type of logical fallacy known as guilt by association.