Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Brownian motion, ionic flux, catalytic reaction and heterogeneous
  nucleation in biological systems   A model to describe the arising of new structures in an initial homogeneous
biological system is proposed. The essay is motivated by the intention to work
on a non-equilibrium situation grouping together several mechanisms and
processes as: catalytic reactions on a surface, diffusion, stimulated migration
and selective heterogeneous reaction. A model for morphogenesis in early
embryos is developed on two basic assumptions; (i) the existence of an
electrified surface that defines the shape (form) of the growing structure and
(ii) a mechanism to select morphogens (ions or free radicals) from an initially
homogeneous medium. The homogeneity is broke when an electric potential arise
between different parcels of the system, triggering a complex dynamic that
drive the development of material deposits into localized regions of the space.
The evolution of the deposits is described by a stochastic formalism allowing
for analytical expressions relating macroscopic.

25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph