biology

  1. G

    probability of finding 2 random DNA fragments matching between genomes

    Hi all, I have a question about probabilty. There are 2 genomes (a long string, composed of 4 letters: A, T, G & C), each 150,000 bases (letters) long. Now, I generate 10,000 random fragments (sub-strings) from each genome, each exactly 20 bases long. What is the probability of finding...
  2. J

    ANOVA or Kruskal Walli

    Hi! I have measured respiration in 3 treated and one untreated control cell line with N= 27, 25, 31 & 31. Can I use a one way anova or should I use a kruskal wallis test? Or are there any better options? Thanks J
  3. W

    [Multinomial Distribution] Help with applying Multinomial to a biological problem

    Hello all, I need help with a stats question I'm trying to solve for a biological question. http://en.wikipedia.org/wiki/Multinomial_distribution. Say you have a town and each street on it will have a different number of bins. In each bin you will find a different number of baseballs, most...
  4. M

    Extract colour values pr pixel from a selected area of a photo - package suggestions?

    I am a biology student currently working on my master thesis which deals with i. a. bird plumage variation. I have many photos taken in the field, and I need programming or a program to acquire the colour values per pixel of the area I am interested in. Unfortunately, I do not know that much...
  5. A

    Nested ANOVA in R

    Hi, I am a master's student in Biology (Ecology and Evolution) and for a statistics course I have to do a case study using real data (datafiles are attached). The dataset containts (among others) measurements of inorganic N, in NO3, NO4 and N, in 8 different valleys. Of these 8 valleys, 4 have...
  6. S

    [Likelihood of embedded Markov chain] Likelihood of Goldman Yang (GY) rate matrix

    This question concerns defining the likelihood of a set of parameters in a rate matrix of an embedded Markov chain. To get a brief idea of the context I will try to explain the problem with a simpler one first. I am working with evolutionary models (see...
  7. E

    [Anova using R] Likely need help setting up a multi way ANOVA, open to other options

    I am analyzing the data from an MRI experiment where we tested a new contrast agent against two control agents in mice with tumors. The experiment There were three treatments. Each treatment was given to three mice. Each mouse was imaged at 16 timepoints. I am analyzing three image slices...
  8. G

    Analysis of respiration

    I am trying to analyze egg respiration data. I have 7 eggs that were measured over a 10 day period. I have data from 45 minute runs, that I have taken 5 minute averages of giving me 9 data points per day per egg. I need to analyze the change in gas over the course of the run. Then I need to 1)...
  9. N

    Need Help Combining 6 Graphs into One

    Hello, I am an undergraduate student in biology. I have not yet completed a statistics course but I do have basic familiarity with graphing in excel. Here is the problem: We did an experiment in lab and we are supposed to write up a lab report which includes graph. We are given the...
  10. N

    Need Help Graphing Multiple Graphs into One Graph

    Hello, I am an undergraduate student in biology. I have not yet completed a statistics course but I do have basic familiarity with graphing in excel. Here is the problem: We did an experiment in lab and we are supposed to write up a lab report which includes graph. We are given the...
  11. E

    Interpreting FFT of biological data

    Hi all, I'm a biological scientist and I'm trying to interpret a FFT of some biological data. Background: I have monitored the length of time an animal stands over six days, so every time the animal stands up we have a time code for when the behaviour started and a duration of how long the...
  12. J

    I believe Kruskal-Wallis is the right choice, but where do I go from there?

    Assumption: Tertiary wing feathers are warmer Hypotheses: 1) During cold weather feather mites will accumulate on the tertiary wing feather 2) During warm weather feather mites will spread evenly over the entire wing In winter 2010-11 and summer 2011 I took exact counts of feather mites for...
  13. A

    Prerequisite for gene regulatory network research (systems biology)

    I would appreciate any advice or directions on what to study and in what order, from basic statistics and probability course to were one is able to model a system, e.g. cellular systems.