(8) Positive values of αi, obj account for amplification targets, whereas negative values denote deletion or attenuation targets.
Deletion or attenuation targets are located in the glycolysis, the TCA cycle and also the oxidative respiratory system.
Deletion or attenuation targets for non-growth conditions were found within the TCA cycle and also reactions linked to respiration and ATP metabolism.
The identification of acetate and acetylphosphate as flux-sum attenuation targets for ethanol overproduction is also an example of how parallel pathways compete for same carbon flux where the perturbation of one can positively favor the other (Fig. 2).
Moreover, a number of reactions, including pyruvate kinase (Pyk), pyruvate dehydrogenase (aceEF), citrate synthase (GltA), aconitase (Can) and succinyl-CoA dehydrogenase (SucCD) reveal negative correlation, i. e. are identified as deletion or attenuation targets.
For example, we also applied the proposed FSA to S. cerevisiae using the iMM904 model [ 38] for succinate overproduction case and identified glyoxylate and acetyl-CoA as intensification and ethanol as attenuation targets, respectively (see Additional file 2 for details).
Alternatively, 20 to 60 kHz is the peak frequency range used by most echolocating bats [21], because the frequency dependent effects of atmospheric attenuation and target strength mean that detection distance and target resolution is optimized within this frequency range [74].
Moreover, a trastuzumab concentration-dependent attenuation of target cancer cell HER2 expression (although direct HER2 internalization by trastuzumab is one possible mechanism of down-modulation of HER2), and reciprocal increase in CD14+ and CD56+ immune cell HER2 expression, was observed in the HER2+ patient tumor cell autologous PBMC trogocytosis assay (Additional file 3: Figure S3A).
Due to the fast attenuation of the target radiation energy, we consider the circular area of the radius of 40 centered at the target in this paper.
The fundamental principle of perfusion CT is based on the temporal changes in tissue attenuation provided the target volume remains stationary in space.
