Hi everyone I need some help comparing curves generated from an experiment examining ecto-parasite loads on fish.
A number of individuals were infected and the number of parasites counted on each fish five times over the next 30 days. The fish showed three basic patterns of response to the initial infection. The first group showed an exponential-like growth of parasites until the end of the experiment (we call these susceptible). The second group showed an initial increase in numbers until around the mid-point after which the numbers dropped, sometimes to zero but usually to low levels (the curve looks like a hill or dome) (resistant type 1). The final group seemed to retain a low load throughout the experiment, neither increasing or decreasing (resistant type 2). I want to be able to do two things with this data. Firstly, I would like to be able to split the fish into the three groups mentioned above using stats, not charts. Secondly, I would like to generate some value/s which I could use as a guide to ‘strength of response’. In this case I would imagine getting something like a high value for resistant type 1 as they show a definite and strong response, this might be followed by a medium value for resistant type 2 as although they did not reduce the parasite load, it was prevented from increasing to high levels, and finally a low value for the susceptible group as they showed no response at all. Please help. I have played with fitting and comparing various curves, putting the data through PCA etc but am having no luck achieving my two aims. Thanks in advance John G . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
