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.
Holiday Weather. The warmest day over the next 7 days in Puerto Vallarta is forecast to be 22nd April at 29Â°C (84Â°F) and the warmest night on 28th April at 18Â°C (64Â°F). The average temperature over the next 7 days is forecast to be 28Â°C (82Â°F) and there will be 7 days of sunshine . The average for April is 24Â°C (76Â°F) in Puerto Vallarta.