Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Permanence for nonautonomous differential systems with delays in the
  linear and nonlinear terms   In this paper, we obtain sufficient conditions for the permanence of a family
of nonautonomous systems of delay differential equations. This family includes
structured models from mathematical biology, with either discrete or
distributed delays in both the linear and nonlinear terms, and where typically
the nonlinear terms are nonmonotone. Applications to generalized Nicholson or
Mackey-Glass systems are given.

6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph