Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Control of Spatially Heterogeneous and Time-Varying Cellular Reaction
  Networks: A New Summation Law   A hallmark of a plethora of intracellular signaling pathways is the spatial
separation of activation and deactivation processes that potentially results in
precipitous gradients of activated proteins. The classical Metabolic Control
Analysis (MCA), which quantifies the influence of an individual process on a
system variable as the control coefficient, cannot be applied to spatially
separated protein networks. The present paper unravels the principles that
govern the control over the fluxes and intermediate concentrations in spatially
heterogeneous reaction networks. Our main results are two types of the control
summation theorems. The first type is a non-trivial generalization of the
classical theorems to systems with spatially and temporally varying
concentrations. In this generalization, the process of diffusion, which enters
as the result of spatial concentration gradients, plays a role similar to other
processes such as chemical reactions and membrane transport. The second
summation theorem is completely novel. It states that the control by the
membrane transport, the diffusion control coefficient multiplied by two, and a
newly introduced control coefficient associated with changes in the spatial
size of a system (e.g., cell), all add up to one and zero for the control over
flux and concentration. Using a simple example of a kinase/phosphatase system
in a spherical cell, we speculate that unless active mechanisms of
intracellular transport are involved, the threshold cell size is limited by the
diffusion control, when it is beginning to exceed the spatial control
coefficient significantly.

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The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
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The categories of this paper are: q-alg
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The categories of this paper are: ao-sci
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The categories of this paper are: funct-an
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The categories of this paper are: hep-lat
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The categories of this paper are: stat
4
The categories of this paper are: cond-mat
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The categories of this paper are: comp-gas
3
The categories of this paper are: physics