Vibration theory of olfaction have a vibrational energy mode compatible with the difference in energies between two energy levels on the receptor, so electrons can travel through the molecule via inelastic electron tunneling, triggering the signal transduction pathway. The vibration theory is discussed in a popular but controversial book by Chandler Burr. The odor character is encoded in the ratio of activities of receptors tuned to different vibration frequencies, in the same way that color is encoded in the ratio of activities of cone cell receptors tuned to different frequencies of light. An important difference, though, is that the odorant has to be able
Cycles of the Kings the king they served. This they did in poems that blended the mythological and the historical to a greater or lesser degree. The resulting stories form what has come to be known as the Historical Cycle, or more correctly Cycles, as there are a number of independent groupings. The kings that are included range from the almost entirely mythological Labraid Loingsech, who allegedly became High King of Ireland around 431 BC, to the entirely historical Brian Boru. However, the greatest glory of the Historical Cycle is the "Buile Shuibhne" ("The Frenzy of Sweeney"), a 12th-century tale told in verse and