Certain gene functions, however, are inherently dosage-sensitive (Fisher and Scambler, 1994). These include: gene products that are part of a quantitative signaling system whose function depends on partial or variable occupancy of a receptor, DNA-binding site, etc.; gene products that compete with each other to determine a developmental or metabolic switch; gene products that co-operate with each other in interactions with fixed stoichiometry (such as the α and β globins or many structural proteins). In each case the gene product is titrated against something else in the cell.

Railways seldom slavishly followed styles to be seen in the mainstream of contemporary architecture, HE [Historic England] explains.

Driverless Tube trains may sound like a dystopian Borisian fantasy, but even if the London mayor may wish to reduce the workforce, much of the actual driving was eliminated from some Underground drivers' jobs as early as 1967 when the Victoria line opened.

All day long and all night men tramped back and forth, Dostoyevskeian figures in rough garb—and slept there, rested and ate there, held services even.