Category: R
-
Rentgen
A unit of ionizing radiation.
-
Rods
Visual receptors that respond to lower light intensities and give rise to achromatic sensations, cones. A stick shape with rounded ends. One of two types of light-sensitive cell in the retina of the eye. Rods are sensitive to dim light, but not to colour. Cells in the retina that are responsible for vision in dim…
-
Rod-cone break
In a curve of dark adaptation, the sudden increase in sensitivity that occurs after a few minutes. Reflects the transition from primarily cone vision to primarily rod vision.
-
Rocky mountain spotted fever
A disease caused by the bite of a tick that is hosting a rickettsia characterized by chills, fever, pains in muscles and joints, and a reddish purple skin eruption. A type of typhus caused by Rickettsia rickettsii, transmitted to humans by ticks. An infection in humans that is transmitted by microscopic parasites called Rickettsiae; also…
-
Rockefeller foundation
Chartered in 1913 for the purpose of promoting the well-being of mankind through out the world. There are five divisions: (a) International Health, (b) Medical Sciences, (c) Natural Sciences, (d) Social Sciences, and (e) Humanities.
-
Roc curve
A curve that shows the relationship between hits and false alarms in a detection experiment.
-
Robinson stretcher
A split-frame stretcher.
-
Robert wood Johnson foundation
Established in 1972 with the objective of improving access to general medical and dental care. Additionally, 1. support for research to make health care arrangements more effective and care more affordable, and 2. support for research, development, and demonstration projects that show promise of helping large numbers of people avoid disabilities and maintain or regain…
-
Rite of passage
A ritualized custom of movement from one social class to another. A ceremony which shows that somebody is moving from one stage of their life to another, e.g. from childhood to puberty or from unmarried to married life.
-
Risky shift
The tendency for a group discussion to lead to more risky decisions than if the individuals in the group were making the decisions individually. Shifts toward caution are also possible.