Cell communication (biology)
In cells, DNA is housed in the nucleus and it never leaves. The DNA within the nucleus is transcribed by tRNA, and the transcriptions of the DNA become RNA. The RNA (ribonucleic acid) leaves the nucleus to float freely around the cytoplasm, and it contains the instructions of the DNA that are vital to the coding, decoding, regulation and expression of genes. The ribosomes then take the RNA messages and turn them into proteins that build cells. When a virus enters a cell and inserts its DNA code into the nucleus, it gets transcribed and released into the cell for the ribosome to make it into a protein. This is how viral infections occur. The cell then explodes with the overproduction of the virus, releasing it into the body to infect any and all other cells it finds. It is theorized that through evolution, cells developed a defense system called RNAi (RNA interference) to stop the production of the proteins that have suspicious mirror image messages of the RNA. They don’t just destroy the suspicious messages, but the correct messages as well to stop all production of that message. This is a cell’s self-destruct mechanism and every cell, plant and animal, have RNAi: a way to turn off the production of a certain gene inside the protein.
Cochlear Limited
Nucleus is a system combining an electrical simulation device that is surgically implanted behind a patient's ear, a processor that captures sounds, and an electrode array that relays the sounds to the brain. It is a direct descendant of the original cochlear implants, also known as Nucleus, developed by Dr Graeme Clark in Melbourne during the 1970s. Nucleus was the first cochlear implant to be approved by the U.S. Food and Drug Administration. The system is upgradable, for example by installing a new sound processor, without surgery. Cochlear's latest processor, Nucleus 6, was launched in 2013 after six years of development. It replaced the Nucleus 5 system. In 2011, the Nucleus 5 CI500 series internal implant was recalled with up to a 24% failure rate. In 2013, the Nucleus implant recorded 99% reliability over the last 8 years, more than any similar product.