Effect of erythromycin on mixed sewage microorganisms
Relative growth rate in biomass of mixed sewage microorganisms (per hour) as a function of increasing concentrations of the antibiotic erythromycin (mg/l).
data(etmotc)
A data frame with 57 observations on the following 4 variables.
cella numeric vector
dose1a numeric vector
pct1a numeric vector
rgr1a numeric vector
Data stem from an experiment investigating the effect of pharmaceuticals, that are used in human and veterinary medicine and that are being released into the aquatic environment through waste water or through manure used for fertilising agricultural land. The experiment constitutes a typical dose-response situation. The dose is concentration of the antibiotic erythromycin (mg/l), which is an antibiotic that can be used by persons or animals showing allergy to penicillin, and the measured response is the relative growth rate in biomass of mixed sewage microorganisms (per hour), measured as turbidity two hours after exposure by means of a spectrophotometer. The experiment was designed in such a way that eight replicates were assigned to the control (dose 0), but no replicates were assigned to the 7 non-zero doses. Further details are found in Christensen et al (2006).
Christensen, A. M. and Ingerslev, F. and Baun, A. 2006 Ecotoxicity of mixtures of antibiotics used in aquacultures, Environmental Toxicology and Chemistry, 25, 2208–2215.
etmotc.m1<-drm(rgr1~dose1, data=etmotc[1:15,], fct=LL.4()) plot(etmotc.m1) modelFit(etmotc.m1) summary(etmotc.m1) etmotc.m2<-drm(rgr1~dose1, data=etmotc[1:15,], fct=W2.4()) plot(etmotc.m2, add = TRUE) modelFit(etmotc.m2) summary(etmotc.m2) etmotc.m3<-drm(rgr1~dose1, data=etmotc[1:15,], fct=W2.3()) plot(etmotc.m3, add = TRUE) modelFit(etmotc.m3) summary(etmotc.m3)
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