Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analysis of a mathematical model for interactions between T cells and
  macrophages   The aim of this paper is to carry out a mathematical analysis of a system of
ordinary differential equations introduced by R. Lev Bar-Or to model the
interactions between T cells and macrophages. Under certain restrictions on the
parameters of the model, theorems are proved about the number of stationary
solutions and their stability. In some cases the existence of periodic
solutions or heteroclinic cycles is ruled out. Evidence is presented that the
same biological phenomena could be equally well described by a simpler model.

8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat