Reduced General Unified Threshold models of Survival (GUTS) with individual tolerance (IT).
GUTS_RED_IT(param, init)an S4 object of type GutsRedIt
optional named list or vector with model parameters
optional named numeric vector to use as initial state
The return value of simulate() will contain values for the state variables,
as well as an additional column S which represents the survival probability
for each time point. S is calculated as described in EFSA (2018) as
S = (1- F(t)). The background hazard rate hb is already considered in state
variable H and therefore does not occur as an additional term to derive S.
The arguments to ODE solver deSolve::ode() control how model equations
are numerically integrated. The settings influence stability of the numerical
integration scheme as well as numerical precision of model outputs. Generally, the
default settings as defined by deSolve are used, but all deSolve settings
can be modified in cvasi workflows by the user, if needed. Please refer
to e.g. simulate() on how to pass arguments to deSolve in cvasi
workflows.
The following list describes the default names and standard units of GUTS-RED state variables:
D, scaled damage (conc)
H, cumulative hazard (-)
The state variables are initialized with zero by default.
kd, dominant rate constant (time^-1)
hb, background hazard rate (time^-1)
alpha, median of thresholds (conc)
beta, shape parameter (-)
The effect endpoint L (lethality) is available for GUTS-RED models.
A value of zero (0.0) denotes no effect on organism survival. A value of
one (1.0) denotes a lethality rate of 100%, i.e. no survivors.
The survival probability S is available in the return value of simulate().
EFSA PPR Panel (EFSA Panel on Plant Protection Products and their Residues), Ockleford C, Adriaanse P, Berny P, et al., 2018: Scientific Opinion on the state of the art of Toxicokinetic/Toxicodynamic (TKTD) effect models for regulatory risk assessment of pesticides for aquatic organisms. EFSA Journal 2018; 16(8):5377, 188 pp. tools:::Rd_expr_doi("10.2903/j.efsa.2018.5377")
Other GUTS-RED models:
GUTS-RED-models,
GUTS_RED_SD()