an introduction for experimentalists
Thanks to Tony Phillips who helped with the text of the English version.
- What is this, in Catastrophe theory
- Below is a java applet (version 1) for doing experiments and finding out whatCatastrophe theory calls ``a catastrophe''
First, imagine you are studying a system, a cell for example. You aredoing experiments. You put the cell in different environmental conditions.You vary the pH and temperature, and explorehow they control the cell's production of a certain protein.The data you obtain are strangeand you are disappointed because you don't very well understand how thetwo environmental factors,together, control the cell's behaviour.
Let me show you a game which mimics this situation (in some sense thisgame is a model for the cell's behaviour): You see below a coloured square.Move the mouse, enter the square, and move the cursor inside the square.The cursor coordinates simulate the two environmental factors which controlcell behaviour and the colour of the square simulates the protein synthesisrate of the cell : blue is a low rate and green is a high one. Playwith the applet (i. e. do experiments with the cell) andtry to write a paper to publish your results...
What do you want to do after your first publication ? Here are sometypical answers:
- I have no results to publish: try it yourself; put the cursor several timesat the same place at the bottom center of the square; sometimes you get a blue colour and sometimes a green one. I can't do anything with sucha system. If the protein is commercially important, I'll find anotherway to synthesize it.
- I want to look inside the cell (or the game) to discovera regulatory factor (or a coding system) :
- (You can't see the source code of the applet . You may learn theJava language just as you may learn the protein synthesis mechanism . You mayknow the components of a computer just as you may know the components of a cell.You may do experiments with the Java language on your computer just as you use your knowledge about protein synthesis to do experiments on the cell. Butyou can't ask the cell creator to give you its program, andso you can't read the source code in Java.)
- Here is a link to GETTINGSTARTED WITH JAVA if you want to learn about the Java language.
- I want to understand this strange behaviour ; I want to searchfor a mathematical model which describes andpredicts the cell (or game) behaviour.
- If this is what you want, click here.
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Auteur: Lucien Dujardin
Faculté de Pharmacie BP 83 F 59006 Lille Cedex France