By Roberta Attanasio Chlorella viruses, or chloroviruses, infect green algae, single-celled organisms present throughout the world in freshwater ecosystems such as lakes and ponds. Now, it seems that chlorovirues also infect humans, causing changes in cognitive functions — the processes by which information is perceived, registered, stored, retrieved, and used. In other words, chloroviruses influence the ability to acquire and use knowledge. These novel findings — published on line in the scientific journal Proceedings of the National Academy of Sciences (October 27, 2014) — confirm that viruses may be able to jump from one kingdom (plants) to another (animals), something that has been shown only in very few instances.  For the study…