The main symptoms of vascular dementia include: 1  Abrupt onset (in some, but not all patients). 2  Progressive deterioration of intellectual abilities, processing speed, cognitive and motor abilities. 3  Progressive memory loss. 4  Slow, unsteady gait. 5  Fluctuating course (in some patients).
Although radio frequency is a rate of oscillation, the term radio frequency or its abbreviation RF are used as a synonym for radio â i.e., to describe the use of wireless communication, as opposed to communication via electric wires. The energy in an RF current can radiate off a conductor into space as electromagnetic waves (radio waves); this is the basis of radio technology. 2  RF current does not penetrate deeply into electrical conductors but tends to flow along their surfaces; this is known as the skin effect.
For other uses, see RF (disambiguation) . Radio frequency (RF): any of the electromagnetic wave frequencies that lie in the range extending from around 7003300000000000000â 3 kHz to 7011300000000000000â 300 GHz, which include those frequencies used for communications or radar signals. The energy in an RF current can radiate off a conductor into space as electromagnetic waves (radio waves); this is the basis of radio technology.