Mesoamerican Long Count calendar Mesoamerican Long Count calendar The Mesoamerican Long Count calendar is a non-repeating, vigesimal (base-20) and base-18 calendar used by several pre-Columbian Mesoamerican cultures, most notably the Maya. For this reason, it is often known as the Maya (or Mayan) Long Count calendar. Using a modified vigesimal tally, the Long Count calendar identifies a day by counting the number of days passed since a mythical creation date that corresponds to August 11, 3114 BCE in the Proleptic Gregorian calendar. The Long Count calendar was widely used on monuments. The two most widely used calendars in pre-Columbian Mesoamerica, were the 260-day Tzolk'in
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