The proton gradients that power respiration are as universal ... is used to pump protons across a membrane — the dam — creating, in effect, a proton reservoir on one side of the membrane.

Color gradient filament is fun stuff to play with ... [David Gozzard] wanted to do some printing with this effect, and learned how to make his own filament to do the job. [ ...

Thus, gene expression is vital to the effectiveness of the gradient in specifying different cell fates. The presence of a Dpp gradient in fruit fly wings has been demonstrated in living flies ...