Cell nucleus
Cell nuclei contain most of the cell's genetic material, organized as multiple long linear DNA molecules in a complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these chromosomes are the cell's nuclear genome and are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expression—the nucleus is, therefore, the control center of the cell. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm, and the nuclear matrix (which includes the nuclear lamina), a network within the nucleus that adds mechanical support, much like the cytoskeleton, which supports the cell as a whole.
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.