stressaddition

This is the R implementation of the tri-phasic concentration-response model introduced in Liess, M., Henz, S. & Knillmann, S. Predicting low-concentration effects of pesticides. Sci Rep 9, 15248 (2019). It allows modeling of ecotoxicological experiments where the response shows signs of a hormesis effect.

Installation

Stressaddition is not on CRAN. You can install the most recent stable version from GitLab using the remotes package:

install.packages("remotes")
remotes::install_gitlab("oekotox/stressaddition", host = "git.ufz.de")

Alternatively there are binary and source builds downloadable from the releases page.

Updating

RStudio's integrated package updater won't detect updates in packages installed from GitHub or GitLab. I recommend running

remotes::update_packages()

in regular intervals to check for updates from those sources.

Citation

Please cite this package if you use it in your analysis. See citation("stressaddition") for details.

Example

library(stressaddition)
model <- ecxsys(
    concentration = c(0, 0.05, 0.5, 5, 30),
    hormesis_concentration = 0.5,
    survival_tox_observed = c(90, 81, 92, 28, 0),
    survival_tox_env_observed = c(29, 27, 33, 5, 0)
)

# Plot the effect and the system stress:
par(mfrow = c(2, 1))
plot_survival(model)
plot_stress(model)

# The LC50 under the influence of toxicant and system tress:
lc(model, "survival_tox_sys", 50)

# The LC10 under the influence  of toxicant, system and environmental tress:
lc(model, "survival_tox_env_sys", 10)

Copyright and License

Copyright (c) 2020,
Helmholtz-Zentrum fuer Umweltforschung GmbH - UFZ.
All rights reserved.

The code is a property of:

Helmholtz-Zentrum fuer Umweltforschung GmbH - UFZ
Registered Office: Leipzig
Registration Office: Amtsgericht Leipzig
Trade Register: Nr. B 4703
Chairman of the Supervisory Board: MinDirig'in Oda Keppler
Scientific Director: Prof. Dr. Georg Teutsch
Administrative Director: Dr. Sabine König

stressaddition is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see https://www.gnu.org/licenses/.