The immune system is a collection of billions of cells that travel through the bloodstream. They move in and out of tissues and organs, defending the body against foreign bodies (antigens), such as bacteria, viruses and cancerous cells.There are two types of lymphocytes :B cells-produce antibodies which are released into the fluid surrounding the bodyâs cells to destroy the invading viruses and bacteria. T cells (see picture opposite) - if the invader gets inside a cell, these (T cells) lock on to the infected cell, multiply and destroy it.here are two types of lymphocytes : B cells-produce antibodies which are released into the fluid surrounding the bodyâs cells to destroy the invading viruses and bacteria. T cells (see picture opposite) - if the invader gets inside a cell, these (T cells) lock on to the infected cell, multiply and destroy it.
Gillespieâs algorithm (Gillespie, 1977) is a way of im-. plementing consistently this probabilistic description of a biological system. The probabilistic. description by its very nature applies to single cells. The connection with molecular concentra-.
Rule Based Optimization: This is an old technique. Basically, the RBO used a set of rules to determine how to execute a query. E.g. If an index is available on a table, the RBO rules can be to always use that index (a RBO for our travel analogy can be avoid all routes with speed brakers).