Is there a general mathematic way to find other LD numbers?If so, what do you need to know to to find it? assume you have LD50.or in other words, is there a formula for LDx given LD50?

Name
Email
Subject
Comment *
File	Select/drop/paste files here
* = required field	[▶ Show post options & limits] Confused? See the FAQ.

File: 1439271041016.png (17.32 KB, 293x302, 293:302, ld50.png)

08/11/15 (Tue) 05:30:40 No.2892

Is there a general mathematic way to find other LD numbers?

If so, what do you need to know to to find it? assume you have LD50.

or in other words, is there a formula for LDx given LD50?

08/13/15 (Thu) 04:36:08 No.2902

The formula depends on the fitted regression of the thing in question. You plot the amount of organisms killed against the dose level used in trials and then fit the points to what is usually a logistic regression. Then you just plug in the whatever X% of dead organisms is to get back the dose required to kill them or the "LDX" value.

08/13/15 (Thu) 04:42:19 No.2903

File: 1439440939566.gif (2.24 KB, 315x233, 315:233, dose-response curve.gif)

Oh and the reason that LD50 is used and not some other value is because it provides the most useful information as it is furthest away from the asymptotic regions of the typical dose-response curve. If you say LD10 or LD90 you have to deal with questions like "How much of a difference would a little bit more or a little bit less of the substance make towards mortality?" The median value on the other hand is crystal clear and doesn't need any extra context.