[Air-L] Research on federated social media

Hello Everyone, Has anyone written or know of social research about mainstream social media (i.e. Facebook, Twitter, Tumblr) alternatives, i.e. decentralized and federated Social Network Sites such as Bolixo, Diaspora, GNU Social, Friendica, Mastodon, MeWe, Pump.io? This seems like an important area, but I haven't been able to turn up much. Best wishes, Dorothy Howard