Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pattern formation driven by nematic ordering of assembling biopolymers   The biopolymers actin and microtubules are often in an ongoing
assembling/disassembling state far from thermal equilibrium. Above a critical
density this leads to spatially periodic patterns, as shown by a scaling
argument and in terms of a phenomenological continuum model, that meets also
Onsager's statistical theory of the nematic--to--isotropic transition in the
absence of reaction kinetics.
  This pattern forming process depends much on nonlinear effects and a common
linear stability analysis of the isotropic distribution of the filaments is
often misleading. The wave number of the pattern decreases with the
assembling/disassembling rate and there is an uncommon discontinuous transition
between the nematic and the periodic state.

25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph