Pulse wave velocity (PWV) is a measure of arterial stiffness.he study of the basic scientific principles of the velocity of the pulse wave through the arterial tree dates back to 1808 with the work of Thomas Young.
Put simply, chain migration is a derogatory term used to describe the ability of U.S. citizens and green card holders to bring their extended family into the country. A majority of the roughly one million foreigners who are allowed to enter the U.S. to become permanent residents each year are approved because they're related to Americans.
Save. Photos.com/Photos.com/Getty Images. Push and pull factors are used to explain why people choose to migrate. Anthropologists studying voluntary human migration have identified various factors that correlate, either positively or negatively, to the intensity of migration flow.his migration occurs because the push factors -- limited economic opportunities and lack of entertainment and diversions -- and pull factors -- jobs, cultural attractions, better services -- are both strong.