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Experiment ID
253, 254
Pathogen
Naegleria fowleri
Contains Preferred Model
1
Reference
Modification of resistance of mice to Naegleria fowleri infections.
Host type
mice
# of Doses
7.00
Μodel
exponential
k
3.42E-07
LD50/ID50
2.03E+06
Dose Units
no of trophozoites
Response
death
Agent Strain
LEE strain
Exposure Route
intravenous
Experiment Dataset
Description: 
mice/ Naegleria fowleri LEE strain model data [1]
Dose Dead Survived Total
1E+06 4 16 20
2.5E+06 4 6 10
2.5E+06 12 8 20
5E+06 19 1 20
5E+06 14 6 20
1E+07 10 0 10
1E+07 20 0 20

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom		 χ20.95,1 
p-value		 χ20.95,m-k 
p-value
Exponential 8.85 -0.000501 6 3.84 
1		 12.6 
0.182
Beta Poisson 8.85 5 11.1 
0.115
Exponential is preferred to beta-Poisson; cannot reject good fit for exponential.

 

Optimized k parameter for the exponential model, from 10000 bootstrap iterations
Parameter MLE estimate Percentiles
0.5% 2.5% 5% 95% 97.5% 99.5%
k 3.42E-07 2.57E-07 2.75E-07 2.84E-07 4.15E-07 4.34E-07 4.67E-07
ID50/LD50/ETC* 2.03E+06 1.48E+06 1.60E+06 1.67E+06 2.44E+06 2.52E+06 2.70E+06
*Not a parameter of the exponential model; however, it facilitates comparison with other models.

 

Parameter histogram for exponential model (uncertainty of the parameter)

Exponential model plot, with confidence bounds around optimized model

References

  1. Adams, A. C., John D. T., & Bradley S. G. (1976).  Modification of resistance of mice to Naegleria fowleri infections.. Infection and immunity. 13, 1387–1391.