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Experiment ID
84
Pathogen
Bacillus anthracis
Agent Strain
Vollum
Contains Preferred Model
No
Reference
Altboum, Z. ., Gozes, Y. ., Barnea, A. ., Pass, A. ., White, M. ., & Kobiler, D. . (2002). Postexposure prophylaxis against anthrax: evaluation of various treatment regimens in intranasally infected guinea pigs. Infection and Immunity, 70, 6231–6241.
Exposure Route
inhalation
Response
death
Host type
guinea pig
# of Doses
6.00
Dose Units
spores
Μodel
beta-Poisson
a
5.49E-01
N50
2.85E+04
LD50/ID50
2.85E+04
Description
Guinea pig/Vollum Strain model data 
Dose Dead Survived Total
200 0 4 4
2000 0 8 8
2E+04 6 6 12
2E+05 10 2 12
2E+06 7 1 8
2E+07 7 0 7

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom		 χ20.95,1 
p-value 		χ20.95,m-k 
p-value
Exponential 29.2 26.6 5 3.84 
2.46e-07 		11.1 
2.11e-05
Beta Poisson 2.58 4 9.49 
0.631
Beta-Poisson fits better than exponential; cannot reject good fit for beta-Poisson.

 

Optimized parameters for the beta-Poisson model, from 10000 bootstrap iterations
Parameter MLE estimate Percentiles
0.5% 2.5% 5% 95% 97.5% 99.5%
α 5.49E-01 2.55E-01 3.03E-01 3.32E-01 5.51E+00 2.45E+03 6.16E+03
N50 2.85E+04 1.00E+04 1.25E+04 1.43E+04 6.57E+04 7.85E+04 1.09E+05

 

Parameter scatter plot for beta Poisson model ellipses signify the 0.9, 0.95 and 0.99 confidence of the parameters.

beta Poisson model plot, with confidence bounds around optimized model

References

  • Altboum, Z. ., Gozes, Y. ., Barnea, A. ., Pass, A. ., White, M. ., & Kobiler, D. . (2002). Postexposure prophylaxis against anthrax: evaluation of various treatment regimens in intranasally infected guinea pigs. Infection and Immunity, 70, 6231–6241.