Multi-TOX
Version 2021.08
Multi-Tox predicts the effect of binary toxicant mixtures. Based on tri-phasic toxicant-response relationships of single toxicants.
For details see: Liess M, Henz S, Shahid N. 2020. Modelling the synergistic effects of toxicant mixtures. Environmental Science Europe.
Sensitivity Distribution
Beta p: The shape parameter p of the beta distribution. Default is 3.2.
Beta q: The shape parameter q of the beta distribution. Default is 3.2.
Toxicant A
Measured A
Concentration: Toxicant concentrations. The value highlighted in bold marks the concentration where the peak of the hormesis likely occurs. This can be changed via ConcentrationHormesis in the Parameters section.
Survival Observed: Measured survival under toxicant stress.
Survival Predicated (Tox+Sys): Modeled survival related to toxicant and system stress conditions.
Parameters A
ConcentrationHormesis: The concentration where hormesis occurs. Must be greater than Concentration2 and less than ConcentrationMax. If the supplied data contain no hormesis then enter the concentration after which there is a sharp decline or "step" in the survival. See publication for details.
SurvivalMax: The theoretical maximum value of the survival. Default is 100.
Plot Survival A
The modeled concentration-response relationships. Dots mark the measured survival. Triangles indicate different lethal concentrations (LC1, LC5, LC10 and LC50). Move the mouse over the triangles or see table LC Values for details).
SurvivalTox+SyS: The modeled survival resulting from toxicant and system stress.
SurvivalTox: The modeled survival under toxicant stress alone (without SyS).
(¹)
Plot Stress A
The relationship between toxicant concentration and stress. Dots mark the values estimated from the measured survival. Lines show the fitted stress used to model the survival.
StressTox+Sys: The sum of toxicant and system stress.
StressTox: The stress induced by contamination with a toxicant.
System StressTox: System stress under toxicant stress conditions.
LC Values A
Lethal concentrations (LC1, LC5, LC10 and LC50) and corresponding survival. Displayed values are rounded to 6 decimal digits. However, you can copy the exact values to your clipboard. (¹)
Curve Points A
Toxicant concentrations and corresponding survival and stress used to plot the curves.
Toxicant B
See 'Toxicant A'.
Mixture A ⊕ B
Data Mixture
Clear Table and add Mixtures of Concentrations from Data A and B: See explanation below.
Concentration ToxA: Toxicant A concentrations.
Concentration ToxB: Toxicant B concentrations.
Survival A⊕B Observed: Observed survival of the mixture.
Survival A⊕B Predicted: Predicted survival of the mixture.
Difference²: The squared difference of the observed and predicted survival.
Class: Classification of the predicted survival of the mixture. The survival percentages are relative to the value of SurvivalMax.
Predicted survival of the mixture for the given combinations of concentrations.
Click the button Clear Table and add Mixtures of Concentrations from Data A and B to reset the table Data Mixure. The table is then prefilled with all combinations of the concentrations of Data A and Data B along with copied values for the column Survival A⊕B Observed wherever one of the two concentrations is 0.
Parameters Mixture
SA Contribution: The proportion of stress addition contributing to the calculation of toxicant stress in the mixture. Must be between 0 and 1 where 1 stands for 100% stress addition.
SurvivalMax: The theoretical maximum value of the mixture survival. Default is 100.
Root Mean Square Error (RMSE): The square root of the mean of all squared differences: √(mean((predicted - observed)²)). This is a measure of the goodness of fit between predicted and observed survival where a lower number indicates a better fit.
Plot Mixture
Classification of the predicted survival of the mixture for the given combinations of concentrations.
Notes
¹) LC-Values are approximated by a linear interpolation of all plot values.
References
For more information contact: matthias.liess@ufz.de