3,139 research outputs found
Constancy of Expression of the Protein Kinase A Regulatory Subunit Rla in Hepatoma Cell Lines of Different Phenotypes
Why spontaneous symmetry breaking disappears in a bridge system with PDE-friendly boundaries
We consider a driven diffusive system with two types of particles, A and B,
coupled at the ends to reservoirs with fixed particle densities. To define
stochastic dynamics that correspond to boundary reservoirs we introduce
projection measures. The stationary state is shown to be approached dynamically
through an infinite reflection of shocks from the boundaries. We argue that
spontaneous symmetry breaking observed in similar systems is due to placing
effective impurities at the boundaries and therefore does not occur in our
system. Monte-Carlo simulations confirm our results.Comment: 24 pages, 7 figure
Competing Glauber and Kawasaki Dynamics
Using a quantum formulation of the master equation we study a kinetic Ising
model with competing stochastic processes: the Glauber dynamics with
probability and the Kawasaki dynamics with probability . Introducing
explicitely the coupling to a heat bath and the mutual static interaction of
the spins the model can be traced back exactly to a Ginzburg Landau functional
when the interaction is of long range order. The dependence of the correlation
length on the temperature and on the probability is calculated. In case
that the spins are subject to flip processes the correlation length disappears
for each finite temperature. In the exchange dominated case the system is
strongly correlated for each temperature.Comment: 9 pages, Revte
Exclusion process for particles of arbitrary extension: Hydrodynamic limit and algebraic properties
The behaviour of extended particles with exclusion interaction on a
one-dimensional lattice is investigated. The basic model is called -ASEP
as a generalization of the asymmetric exclusion process (ASEP) to particles of
arbitrary length . Stationary and dynamical properties of the -ASEP
with periodic boundary conditions are derived in the hydrodynamic limit from
microscopic properties of the underlying stochastic many-body system. In
particular, the hydrodynamic equation for the local density evolution and the
time-dependent diffusion constant of a tracer particle are calculated. As a
fundamental algebraic property of the symmetric exclusion process (SEP) the
SU(2)-symmetry is generalized to the case of extended particles
Task-dependent eye-movement patterns in viewing art
In art schools and classes for art history students are trained to pay attention to different aspects of an artwork, such as art movement characteristics and painting techniques. Experts are better at processing style and visual features of an artwork than nonprofessionals. Here we tested the hypothesis that experts in art use different, task-dependent viewing strategies than nonprofessionals when analyzing a piece of art. We compared a group of art history students with a group of students with no art education background, while viewing 36 paintings under three discrimination tasks. Participants were asked to determine the art movement, the date and the medium of the paintings. We analyzed behavioral and eye-movement data of 27 participants. Our observers adjusted their viewing strategies according to the task, resulting in longer fixation durations and shorter saccade amplitudes for the medium detection task. We found higher task accuracy and subjective confidence, less congruence and higher dispersion in fixation locations in experts. Expertise also influenced saccade metrics, biasing it towards larger saccade amplitudes, advocating a more holistic scanning strategy of experts in all three tasks
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