Migration typically involves directed movement, that is, a preferred direction along which the bird wants to travel (Newton 2007).
Each head-direction cell shows a preferred direction, firing rapidly whenever the animal faces in the cell's preferred direction.
So galaxies as seen from Earth ought all to be distorted in a preferred direction.
The Earth's magnetic field aligns the grains, yielding a preferred direction of magnetization.
The material then has a preferred direction of magnetization, and in this direction high permeability and low loss are attained.
Neurons that control movement tend to have a preferred direction, and fire their electrical pulses more frequently to perform a movement in that direction.
As Jacobson later noted, the team even memorized scripts for "verbal gambits" that would steer the interrogation in a preferred direction.
The stress is generally not the same in all directions, so that movement in a preferred direction occurs, with slippage planes, granulation, or partial flowage being oriented preferentially.
Wu observed that there is a preferred direction of emission and that, therefore, parity is not conserved for this weak interaction.
Other ganglion cells have been shown to have a directional sensitivity, responding to a moving spot of light only if this moves in a preferred direction and showing inhibition of background discharge if movement is in the null direction.
Sometimes there is a preferred direction, but that restriction is not strict.
