The mean time to onset of a 12% increase in FEV1 for PROVENTIL HFA Inhalation Aerosol was 7 minutes and the mean time to peak effect was approximately 50 minutes. The mean duration of effect as measured by a 12% increase in FEV1 was 2.3 hours. In some pediatric patients, duration of effect was as long as 6 hours.
The Aztecs, who probably originated as a nomadic tribe in northern Mexico, arrived in Mesoamerica around the beginning of the 13th century.
Chichen Itza is a large Maya city in Mexico. It is a UNESCO World Heritage Site, and has been since 1988. It is located on the Yucatan Peninsula, in the heart of what was once the Classic Maya civilization. The area where Chichen Itza was settled is rather devoid of surface water, with no large rivers.