Xque
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Microbiology question
lol, this is our first problem and I'm already having trouble. I never really liked math 
Anyway, the question goes like this: "A grenade containing one liter of Bacillus anthracis spores is detonated above a city of 10,000 residents, with
an area of 1 km^2. Assume that the spores are evenly distributed, How many spores would be found in an area of 1 m^2? The spores diameter is 1
μm"
So, 1 liter is distributed over 1 km^2. I divide this by thousand, and I obtain that there's 1ml/1m^2. I know that B. anthracis spores arent
spherical, but I don't know what else to do. So I assume that they are, calculate their volume (pi * 1μm)/6 ~ 0,52 μm^3
1 l = 1 mm^3. So, I convert the the volume to mm^3 (0,52μm * 10^-3= 5,2 * 10^-4 mm^3 ). Total volume/volume of spore = Number of spores. 1 mm^3/
5,2 * 10^-4 mm^3 ~ 1923 spores/L. This means that 1 ml contains aproximately 2 spores This doesn't sound right 
Do you agree with this method?
"What are the advantages and drawbacks of using B. anthracis as a biological weapon?".
Advantages:
Stable spores.
Aerobic organism (too obvious?)
High fatality when inhaled (~90%, IIRC?)
Drawbacks:
The BWC
Risk of ones allies getting infected.
Long term ecological disturbance (well, it is a drawback if it's an area you plan to conquer  ).
Any suggestions?
"How could you maximise enemy casualties and minimize your own?"
Use a highly virulent strain like Ames or Vollum, perhaps even a genetically altered strain. Vaccinate ones own soldiers.
Suggestions?
[Edited on 4-4-2006 by Xque]
[Edited on 4-4-2006 by Xque]
You talk the talk, but do you walk the walk?
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neutrino
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v = pi * r<sup>3</sup>
v<sub>spore</sub> = pi*(0.5um)<sup>3</sup> = 0.392 um<sup>3</sup> = 3.92 E-13 cm<sup>3</sup>
Assuming a random packing density of 0.64 (from here), this means 1.63 E12 spores / cm<sup>3</sup>.
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Xque
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Thanks. Didn't you forget to multiply by 4/3 in your calculations though? This will result in the same sporevolume as my calculations did.
Where's all the fancy molecular biologists when you need them? 
[Edited on 5-4-2006 by Xque]
You talk the talk, but do you walk the walk?
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MargaretThatcher
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Come now, 1 square kilometre contains 10^6 square metres.
Given no further information, you might as well assume the spores are close packed cubes. This easily gives a concentration of 10^12 spores/litre.
Thus, you have 10^6 spores/square metre.
The key problem is storing spores viably and then having them disperse finely. This is no easy problem. For example Iraq manufactured a liquid form
that could be sprayed but had a limited lifetime of a year or so (hence the bogus claims concerning Iraq's supposed remaining WMDs). Properly dried
spores have a very long lifetime but tend to clump - the USA has put much effort into developing reliable anti-clumping agents for its WMD.
The reformative effect of punishment is a belief that dies hard, I think, because it is so satisfying to our sadistic impulses. - Bertrand Russell
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