Nitrogen fixed in the form of biologically useful compounds is a limiting factor for photosynthesis.

It plays a major role in the sulfur assimilation pathway: converting sulfite to a biologically useful sulfide, which can be incorporated into the organic compound homocysteine.

Though nitrogen is plentiful in the Earth's atmosphere, relatively few plants engage in nitrogen fixation (conversion of atmospheric nitrogen to a biologically useful form).

A biologically useful implementation with accurate alignment performance is of course the eventual goal of this line of work, but is not the point of the present paper.

But it is not yet known whether eating grapes or drinking red wine results in biologically useful levels of resveratrol in a person's blood.

Lightning, a non-biological process, has been found to produce biologically useful material through the oxidation of inorganic matter.

As a result of more numerous lightning strikes, nitrogen fixation would deposit more biologically useful forms of nitrogen into various ecosystems, encouraging primary production.

The current implementation of the algorithm is not biologically useful.

How can the brain extract biologically useful information from such multidimensional sensory input?

It's not clear to me that biologically useful forms of those nutrients would be abundant.