These are some talks/presentations I've done:
Some months ago, Roberto Maestre and me gave a talk called "Twitter Dynamics". It was an introductory view of some techniques that can be applied to learn a bit more about how the information flows in a network like Twitter and to identify roles in that network such as major influencers or information disseminators.
Here you can find the code we used for the presentation: https://github.com/ParadigmaLabs/seminario_twitter_dynamics
Video and Slides (in spanish):