137763 EF ejection fraction 13527 137922 EF ecological footprint 107 138530 ef effect 13 137739 EF elongation factor 1-alpha 12 138241 EF extracellular protein factor 7 138261 EF external face 4 138533 ef enantiomeric fluorescence difference 3 138534 ef effective length L 2 137724 ef en face 2 138531 ef enantiomeric fluorescence enhancement ratio 2 138528 ef early-flowering 1 138529 ef ecological footprint per capita 1 138532 ef effective fusion rate constant, k 1 138535 ef effective refractive index n 1