Sciencemadness Discussion Board » Fundamentals » Beginnings » Microbiology question Select A Forum Fundamentals   » Chemistry in General   » Organic Chemistry   » Reagents and Apparatus Acquisition   » Beginnings   » Responsible Practices   » Miscellaneous   » The Wiki Special topics   » Technochemistry   » Energetic Materials   » Biochemistry   » Radiochemistry   » Computational Models and Techniques   » Prepublication Non-chemistry   » Forum Matters   » Legal and Societal Issues

Author: Subject: Microbiology question
Xque
Harmless

Posts: 20
Registered: 8-11-2005
Location: Europe
Member Is Offline

Mood: :S

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?".

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?
neutrino
International Hazard

Posts: 1583
Registered: 20-8-2004
Location: USA
Member Is Offline

Mood: oscillating

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>.

Xque
Harmless

Posts: 20
Registered: 8-11-2005
Location: Europe
Member Is Offline

Mood: :S

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?
MargaretThatcher
Hazard to Self

Posts: 54
Registered: 21-3-2006
Location: Tonga
Member Is Offline

Mood: Handbagging

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

 Sciencemadness Discussion Board » Fundamentals » Beginnings » Microbiology question Select A Forum Fundamentals   » Chemistry in General   » Organic Chemistry   » Reagents and Apparatus Acquisition   » Beginnings   » Responsible Practices   » Miscellaneous   » The Wiki Special topics   » Technochemistry   » Energetic Materials   » Biochemistry   » Radiochemistry   » Computational Models and Techniques   » Prepublication Non-chemistry   » Forum Matters   » Legal and Societal Issues