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.
Weather in Puerto Vallarta. Puerto Vallarta has a tropical climate with extremely pronounced wet and dry seasons. High temperatures are assured year round thanks to its positioning so close to the equator, and it is often compared to Hawaii which sits at the same latitude. Puerto Vallarta is a resort city in Mexico, on the country's west coast.