Experiment ID
243
Pathogen
Agent Strain
Philadelphia 1
Contains Preferred Model
No
Reference
Saslaw, S. ., & Carlisle, H. N. (1966). Aerosol infection of monkeys with Rickettsia rickettsii. Bacteriological Reviews, 30, 3.
Exposure Route
inhalation
Response
death
Host type
guinea pig
# of Doses
5.00
Dose Units
CFU
Μodel
exponential
k
4.17E-05
LD50/ID50
1.66E+04
Description
Guinea pigs/ Philadelphia 1 Strain model data
Dose Dead Survived Total
1E+04 1 4 5
15000 0 3 3
2E+04 5 2 7
5E+04 3 0 3
1E+05 5 0 5

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom
χ20.95,1 
p-value
χ20.95,m-k 
p-value
Exponential 5.85 -0.000131 4 3.84 
1
9.49 
0.211
Beta Poisson 5.85 3 7.81 
0.119
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 4.17E-05 2.29E-05 2.68E-05 3.00E-05 5.87E-05 6.78E-05 7.86E-05
ID50/LD50/ETC* 1.66E+04 8.82E+03 1.02E+04 1.18E+04 2.31E+04 2.59E+04 3.03E+04
*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