Not to be confused with group presentation. Representation theory is a branch of mathematics that studies abstract algebraic structures by representing their elements as linear transformations of vector spaces, and studies modules over these abstract algebraic structures.
The signature effect of HIV infection, and the cause of AIDS, is disruption of the T-lymphocyte branch of the immune system and in particular the destruction of CD4+ T-helper cells.
There are two types of HIV, HIV-1 and HIV-2, as well as several related viruses that infect certain monkeys or great apes.HIV-1 can be found throughout the world, but HIV-2 is almost exclusively limited to West Africa.IV infects cells of the human immune system, particularly a kind of white blood cell called the CD4 T-cell. These cells help in identifying and destroying harmful material in the body, including bacteria, viruses, parasites, and even some cancer cells.