Recent content by Roo2

I'm concerned that the treatment proposed above doesn't keep the units in mind. I think it may be helpful for me to have a concrete example. Let's say we perform the analysis with the data below (generated randomly for the sake of this post): A1: 3623 Fluorescence Units B1: 0.074 Absorbance...

Thanks for your help! Is there a statistical test to see if ΔBGA and ΔBGB are correlated, or is it decided by logical inference? The setup of the experiment is that I'm measuring the optical density and light emitted by bacterial cultures using two different instruments. The background...

Hello, I have a set of N samples, each of which yields the measurable variables A and B. I am interested in computing the mean and standard error of the ratio A/B within the group. The catch is that I need to do background subtraction on both A and B, and the two different background values BGA...

Hello, Upon following advice from BvU I'm starting a new thread to request help on a concrete issue I have. I have a container with 12x8 wells. Each well contains a roughly equal amount of bacteria. The bacteria are fluorescent, and I am trying to quantify their fluorescence as precisely as...

Thanks! This was very informative. If I may, I'd like to ask one more question that's related to this topic, but not necessarily to the subject line. Quantity B is related in a linear way to quantity A - the more quantity B there is, the more quantity A. When I measure these quantities for a...

Hello, I have an experiment that I'm trying to conduct where I measure quantity A and normalize by quantity B. I then want to report normalized quantity A with error bars showing standard deviation. Quantity B is obtained via a standard curve that I generated (8 data points measured once each...

Thank you again. I was trying to reconcile my result with the professor's assertion that the Fourier transform will be "sinc squared". Thank you very much for your help; I really appreciate it.

jbunnii, thank you very much for your help! It's a relief that I haven't forgotten my basic calculus. I've always been horrible at trig identities; maybe this lecture series will finally bring me up to par. I have one quick question remaining: In order to apply the identity above, I had to...

Thanks to everyone for the help. I had to take a hiatus due to exams, but now I'm trying to figure it out again. I'm using jbunnii's tip to set it up, but I still can't get the correct answer. I've checked over my math three times and can't see what I'm doing wrong. I'm getting the ω^2 in the...

If by electromagnetic field you mean light, then you can tag these molecules with a fluorophore and detect that as a surrogate.

Thanks for the replies. I'm trying to go from weight to concentration... there are a couple confounding factors. If I assume that all of the drug is retained for the first couple hours of dosage, then I'm faced with deciding what volume of water to use. Wiki give a 40L figure for an average...

I'm trying to figure out a typical range of physiological concentrations for pharmaceutical drugs. I'm looking through papers that report candidate drugs administered to cell cultures; these papers report LD50 concentrations anywhere from 1 to 100 μM. I don't have any pharmacology experience so...

Thanks for your help. Yes, I can see that it can be done via the convolution theorem, and the convolution of a rectangle with itself being a triangle is intuitively clear, but shouldn't this be a relatively simple transformation to perform directly? It's making me very frustrated that I can't...

Homework Statement Hello I'm learning Fourier transforms via the Stanford lecture series on Youtube. In the 6th lecture, the professor claims that the FT of a triangle function is the square of the sinc function. I'm trying to derive this, but I can't get my math to work out. Could someone...

Deriving addition of sines from Euler's formula (edit: please ignore) Homework Statement I'd like to derive the value of sin(2πkt + θ) so that I can convince myself that the Fourier sum in terms of sines and cosines works. I found the derivation on Wolfram by using the full Euler's formula...