A cohort is a group of people who share a common characteristic or experience within a defined period (e.g., are currently living, are exposed to a drug or vaccine or pollutant, or undergo a certain medical procedure).
A rift valley is a lowland region formed by the interaction of Earth's tectonic plates. This small rift valley has a typical formationâlong, narrow, and deep. It was formed by the Thingvellir rift, where the North American and Eurasian tectonic plates are tearing, or rifting, apart over a hotspot on the island of Iceland.
Oculus Rift worn at a research showcase. The Oculus Rift is a virtual reality head-mounted display. Software, most notably video games, must be custom programmed to use the Rift. Developer kit preorders were made available for $300 through Oculus VR's website starting on September 26, 2012.