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Experiment ID
253, 254
Pathogen
Naegleria fowleri
Agent Strain
LEE strain
Contains Preferred Model
Yes
Reference
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. Retrieved from http://iai.asm.org/content/13/5/1387.full.pdf+html
Exposure Route
intravenous
Response
death
Host type
mice
# of Doses
7.00
Dose Units
no of trophozoites
Μodel
exponential
k
3.42E-07
LD50/ID50
2.03E+06
Description
mice/ Naegleria fowleri LEE strain model data 
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

  • 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. Retrieved from http://iai.asm.org/content/13/5/1387.full.pdf+html