Mesoamerican calendars was of ritual significance to a number of Mesoamerican cultures. A third major calendar form known as the Long Count is found in the inscriptions of several Mesoamerican cultures, most famously those of the Maya civilization who developed it to its fullest extent during the Classic period (ca. 200–900 CE). The Long Count provided the ability to uniquely identify days over a much longer period of time, by combining a sequence of day-counts or cycles of increasing length, calculated or set from a particular date in the mythical past. Most commonly, five such higher-order cycles in a modified vigesimal (base-20)
Vertebral fixation pedicle fasteners. More information about this specific spinal fixation device can be found in The United States Patent Service’s November 13, 2007 publication of new patents. This patent can currently (September 23, 2008) be found on The U.S. Patent Website. Vertebral fixation Vertebral fixation (also known as "spinal fixation") is a orthopedic surgical procedure in which two or more vertebrae are anchored to each other through a synthetic "vertebral fixation device", with the aim of reducing vertebral mobility and thus avoiding possible damage to the spinal cord and/or spinal roots. A vertebral fixation procedure may be indicated in cases of