FIGURE 1.

Pictorial representation of the State-Vector Model. Cells in state 0 represent normal cells. The rate constants of DSB formation in specific transcriptionally active areas of the genome and in other inactive domains of DNA are denoted as k_01s and k_01ns, respectively. k₂₃ denotes the rate constant of DSB interaction and k₃₄ is the rate constant of damage fixation. State 4 cells are initiated and can be eliminated by a dose-rate independent protective apoptosis-mediated bystander effect (k_ap, dashed arrow) in addition to the dose-rate dependent pathway for necrotic cell killing (k_d). The mitotic rate constant is denoted as k_m (cell divisions per day). A fraction F of the initiated cells cycles at an elevated mitotic rate (k_mp). The rate constants for repair of DSBs in transcriptionally active and inactive DNA are represented by k_rsand k_rns, respectively. Cell-cycle associated postreplication repair (rate constant k_m) is possible for cells in states 1s, 1ns, and 2.