Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Collective durotaxis of cohesive cell clusters on a stiffness gradient   Many types of motile cells perform durotaxis, namely, directed migration
following gradients of substrate stiffness. Recent experiments have revealed
that cell monolayers can migrate toward stiffer regions even when individual
cells do not -- a phenomenon known as collective durotaxis. Here we address the
spontaneous motion of finite cohesive cell monolayers on a stiffness gradient.
We theoretically analyze a continuum active polar fluid model that has been
tested in recent wetting assays of epithelial tissues, and includes two types
of active forces (cell-substrate traction and cell-cell contractility). The
competition between the two active forces determines whether a cell monolayer
spreads or contracts. Here, we show that this model generically predicts
collective durotaxis, and that it features a variety of dynamical regimes as a
result of the interplay between the spreading state and the global propagation,
including sequential contraction and spreading of the monolayer as it moves
toward higher stiffness. We solve the model exactly in some relevant cases,
which provides both physical insights into the mechanisms of tissue durotaxis
and spreading as well as a variety of predictions that could guide the design
of future experiments.

34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int