2. Paul R. Ehrlich (1932-), American evolutionary and population biologist.
- Pauling, Linus
how did atoms bond together to form molecules? In order to find out, he turned from chemical engineering to chemical theory. He enrolled in the first graduate program that offered adequate support, choosing a fledgling Pasadena research school, the California Institute of Technology, or Caltech. Pauling became one of the first chemistry students in an […]
- Pavlov conditioning
The Russian physiologist Ivan Petrovich Pavlov (1848-1936) conditioned dogs to respond in what proved to be a predictable manner, for example, by first ringing a bell before feeding them and then simply ringing the bell upon which stimulus they would begin to salivate as if they were about to eat.
- Pavlov pouch
At different points along the dogs’ digestive tracts, the Russian physiologist Ivan Petrovich Pavlov (1848-1936) surgically created pockets (“Pavlov pouches”) from which he could obtain secretions, the aim being to study the physiology of the digestive tract. He did so from the salivary glands down to the stomach, liver and pancreas with considerable success and […]
- Pavlovian conditioning
A method to cause a reflex response or behavior by training with repetitive action. The Russian physiologist Ivan Petrovich Pavlov conditioned dogs to respond in what proved to be a predictable manner. For example, when he customarily rang a bell before feeding them, the dogs would begin to salivate whenever the bell rang. The principles […]
One in a family of Pax genes involved in regulating embryonic development at the level of transcription. The Pax3 gene is on chromosome 2 in band q35. It encodes a DNA-binding transcription factor that is expressed in the early embryo. Mutation of Pax3 leads to Waardenburg syndrome with a wide bridge of the nose; pigmentary […]