The use of restriction enzymes as a tool for recombining, or joining, different DNA fragments was first illustrated in yet another classic paper, this time by Stanford University researchers Janet Mertz and Ronald Davis (Mertz & Davis, 1972).
Averages for Puerto Vallarta in February. The temperatures are still very warm in Puerto Vallarta, Mexico, in February, even though itâs still winter. Thanks to the cityâs location close to the equator, it enjoys good weather all year round providing the perfect place to head for a winter beach break â it certainly beats the cold European winter.
During the summer months, the temperatures range from 85-90 during the day and 80-85 at the night. It is also very humid during July, August and September. Summer time considered low season and is when Mexican nationals take vacation and Puerto Vallarta is very popular. It can be just as busy as the high season. There are over 300 sunny days a year in Puerto Vallarta. The rainy season lasts from about mid-June through mid October. A chart with the monthly statistics for high and low temperatures, average amount of rainfall and average number of rain days is on Puerto Vallarta Weather Page- along with the current weather at Puerto Vallarta's International Airport.