What is "brain drain" in reference to the russian diaspora?

The "brain drain" in reference to the Russian diaspora is well educated and talented individuals emigrating from the Russian Federation.  Russia is a country attracting migrants, migration policy is focused on the immigration and labor migration,  emigration was conceptualized as a “brain drain” in the 1990s it's for a problem and the main intention of the migration policy turned into the restraint of the outflow of the high-qualified personnel.

When a virus infects a host cell, it uses the cell's machinery to make copies of its own genetic material in a process called replication. finally, during the process of self-assembly, that protein shell and the copies of the virus's genetic material are assembled into new viruses.