If a GFCI device trips and the fault is later fixed, then the user resets the GFCI device by pushing the reset button. If the problem is not fixed, the GFCI keeps the circuit shut off and will not reset. There is also a test button, which will cause the GFCI to trip if it is working properly. GFCI outlets should be tested at least once a month.
GFCI devices employ a timing standard to prevent false "nuisance" tripping and may also protect against improper Neutral-Earth connections.
Multiple standard (non-GFCI) sockets can be protected by being wired in a string to the output of a single GFCI wall outlet although the wiring has to be carefully done considering the maximum load and to prevent false "nuisance" tripping.
GFCIs are available in two types: the circuit breaker that installs in an electrical panel, and the receptacle type that installs into an electrical box. GFCIs that attach to appliance cords, or are built in to extension cords, are also available. Newer hair dryers may have them also, appearing as a small box at the end of the power cord or on the handle itself.
Since a GFCI only monitors current on the hot leg compared to the neutral, the GFCI can be used to upgrade older two-prong (non-grounded) outlets to three-prong (grounded/earthed) outlets without installing any new wire. A circuit with a GFCI device without a ground is far safer than a two-prong outlet without a ground. A GFCI installed this way must be labeled "No Equipment Ground."
When a GFCI is installed in the electrical box without connecting the ground screw (as there is no ground wire), a label that says "No Equipment Ground" is placed on the GFCI outlet and all downstream outlets. Several of these labels are usually included with the GFCI. In some parts of the world, "ground" is called "earth".
GFCIs are a suitable replacement for two prong outlets without a grounded wire. The National Electric Code requires GFCI protection in dwelling on kitchen counter tops, bathrooms, unfinished basements not intended as habitable rooms, crawl spaces, garages, sinks where the receptacles are installed within 6 feet from the top edge of the bowl of the sink, boathouses, bathtubs or shower stalls where receptacles are installed within 6 feet from the edge of the bathtub or shower, laundry areas, outdoors except for receptacles that are not readily accessible and are supplied by a branch circuit dedicated to electric snow-melting, deicing, or pipeline and vessel heating equipment shall be installed in accordance with NEC 426.28 or 427.22 as applicable. (NEC 210.8 (A))
GFCI protection is required on construction sites.
Calico cat
Calico cat is an American name for cats with three colors. Outside of North America they are usually called tortoiseshell cats or 'tortie-and-white'. A calico cat has a coat of orange or brown and black spots on a white background. It is not a breed of cat.
Nearly all calico cats are female. There are male calico cats, but they are very rare. Only one of every 3000 calico cats are male.
A single X chromosome can have either a black allele of the coloration gene or an orange version, but not both. However, a female cat has two X chromosomes, so it can have both versions, black on one chromosome and orange on the other, making the cat a calico. A male cat usually has one X chromosome and one Y chromosome. A Y chromosome does not have a color gene, so the cat can have either an orange or a black gene, but not both. Calico cats are often used as an example in biology classes when discussing sex chromosomes.
During the early stages of development, when the cat is still an embryo, in each cell one of the X chromosomes (either the black one or the orange one) deactivates. It is called X-inactivation. All cells that were copied from a cell with a deactivated X chromosome will also have the same X chromosome deactivated. This is what leads to formation of the spots. The earlier in development the X chromosomes deactivate, the larger the spots will be. Deactivation of one of the X chromosomes happens in all female mammals. The white coloring on a calico is from a separate gene unrelated to the orange or black genes. Whether or not a cat is a calico is determined by genetics, but the actual layout of the spots is not. The layout of the spots is almost random. It is not possible to selectively breed or clone calico cats: an attempt to clone a calico cat will produce a black and white cat or orange and white tabby cat. The tortoiseshell cat is similar, although on a tortoiseshell cat the spots are usually smaller and closer together and there is less or no white.
It is possible for a male cat to be a calico if it has Klinefelter's syndrome, where it has two X chromosomes and one Y chromosome, though not all cats with Klinefelter's syndrome are calico.
In Japan, calico cats are said to bring good luck. In many Japanese shops there is a calico Japanese Bobtail figurine called the Maneki Neko, which is said to bring good luck to the shop's owner.
Bruce Beutler
Bruce Alan Beutler M.D. (born December 29, 1957 in Chicago, Illinois) is an American immunologist and geneticist of Jewish descent. Together with Jules Hoffmann, he received one-half of the 2011 Nobel Prize in Physiology or Medicine, for "discoveries concerning the activation of innate immunity" (the other half went to Ralph Steinman for "his discovery of the dendritic cell and its role in adaptive immunity").
Beutler is currently Director of the Center for the Genetics of Host Defense at the University of Texas Southwestern Medical Center in Dallas, Texas and Professor and Chairman of the Department of Genetics at The Scripps Research Institute, in La Jolla, California. His father, Ernest Beutler, a hematologist and medical geneticist, was also a Professor and Department Chairman at Scripps.
Beutler is best known for his pioneering molecular and genetic studies of inflammation and innate immunity. Interested in the mechanism by which lipopolysacchride (LPS) activates mammalian immune cells, Beutler identified the LPS receptor. Identification of the receptor hinged on the positional cloning (a method of gene identification) of the mammalian "Lps" locus, which had been known since the 1960s as a key gene for biological responses to LPS.
Beutler thus discovered the key sensors of microbial infection in mammals. He found that one of the mammalian toll-like receptors, TLR4, acts as the membrane-spanning component of the mammalian LPS receptor complex. The TLRs work in the perception of microbes. Ten are now known in humans. Each detects signature molecules produced early in an infection. These receptors also work in severe illness, including shock and systemic inflammation as it occurs in the course of an infection. They are also active in sterile inflammatory and autoimmune diseases such as systemic lupus erythematosus. The research on TLRs won him the Nobel Prize in 2011.
The positional cloning of "Lps" was completed in 1998. Beutler continued to analyse immunity in mammals. His work found numerous signalling molecules of the innate immune response, and helped to work out the biochemistry of innate immunity.
Jules Hoffmann
Jules A. Hoffmann (born 2 August 1941) is a Luxembourg-born French biologist. He is a research director and member of the board of administrators of the National Center of Scientific Research (CNRS) in Strasbourg, France. In 2007, he became President of the French Academy of Sciences.
Together with Bruce Beutler, Hoffmann received one-half of the 2011 Nobel Prize in Physiology or Medicine for "their discoveries concerning the activation of innate immunity". Hoffmann discovered the function of the fruit fly "Toll" gene in innate immunity. Its mammalian homologues, the toll-like receptors, were discovered by Beutler. Toll-like receptors identify constituents of other organisms like fungi and bacteria, and trigger an immune response. This explains how septic shock can be triggered by bacterial remains.