Fractionation of carbon isotopes in oxygenic photosynthesis values more similar to C3 plants. In contrast to terrestrial plants, where CO diffusion in air is relatively fast and typically not limiting, diffusion of dissolved CO in water is considerably slower and can often limit carbon fixation in phytoplankton. As gaseous CO is dissolved into aqueous CO, it is fractionated by both kinetic and equilibrium effects that are temperature-dependent. Relative to plants, the dissolved CO source for phytoplankton can be enriched in C by about 8‰ from atmospheric CO. Isotope fractionation of C by phytoplankton photosynthesis is affected by the diffusion of extracellular aqueous CO into the cell, the
Need for achievement do) assess such things as "creativity" in any general sense. One has always to ask "creativity in relation to what?" So McClelland's measures, originally presented as means of assessing "personality", are best understood as means of measuring competence in ways which break radically with traditional psychometric approaches. Everybody has different goals and needs for achievement based off many factors like past experiences, education, the risks, and the feedback they will receive. Need for achievement Need for achievement (N-Ach) refers to an individual's desire for significant accomplishment, mastering of skills, control, or high standards. The term was first used by Henry