Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Inter-filament Attractions Narrow the Length Distribution of Actin
  Filaments   We show that the exponential length distribution that is typical of actin
filaments under physiological conditions dramatically narrows in the presence
of (i) crosslinker proteins (ii) polyvalent counterions or (iii) depletion
mediated attractions. A simple theoretical model shows that in equilibrium,
short-range attractions enhance the tendency of filaments to align parallel to
each other, eventually leading to an increase in the average filament length
and a decrease in the relative width of the distribution of filament lengths.

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The categories of this paper are: math
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn
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The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin