"Net uptake" refers to the overall amount or quantity taken in or absorbed. It indicates the difference between the total amount received and the total amount given out in a specific context. Full definition
«This amount is in the order of magnitude of the annual net uptake of carbon by the biosphere of the oceans,» notes Markus Reichstein. (iiasa.ac.at)
As CO2 concentrations increase and climate changes, feedbacks from terrestrial stores of carbon in forests and grasslands, soils, wetlands, peatlands and permafrost, as well as from the ocean, would reduce net uptake of CO2 (Denman et al., 2007 Sections 7.3.3 and 7.3.4). (ipcc.ch)
An increased net uptake of EAAs translates to increased muscle protein synthesis. (strengthsensei.com)