216,209 research outputs found
The group of causal automorphisms
The group of causal automorphisms on Minkowski space-time is given and its
structure is analyzed
The q-component static model : modeling social networks
We generalize the static model by assigning a q-component weight on each
vertex. We first choose a component among the q components at random
and a pair of vertices is linked with a color according to their weights
of the component as in the static model. A (1-f) fraction of the entire
edges is connected following this way. The remaining fraction f is added with
(q+1)-th color as in the static model but using the maximum weights among the q
components each individual has. This model is motivated by social networks. It
exhibits similar topological features to real social networks in that: (i) the
degree distribution has a highly skewed form, (ii) the diameter is as small as
and (iii) the assortativity coefficient r is as positive and large as those in
real social networks with r reaching a maximum around .Comment: 5 pages, 6 figure
Domain-mediated interactions for protein subfamily identification
Within a protein family, proteins with the same domain often exhibit different cellular functions, despite the shared evolutionary history and molecular function of the domain. We hypothesized that domain-mediated interactions (DMIs) may categorize a protein family into subfamilies because the diversified functions of a single domain often depend on interacting partners of domains. Here we systematically identified DMI subfamilies, in which proteins share domains with DMI partners, as well as with various functional and physical interaction networks in individual species. In humans, DMI subfamily members are associated with similar diseases, including cancers, and are frequently co-associated with the same diseases. DMI information relates to the functional and evolutionary subdivisions of human kinases. In yeast, DMI subfamilies contain proteins with similar phenotypic outcomes from specific chemical treatments. Therefore, the systematic investigation here provides insights into the diverse functions of subfamilies derived from a protein family with a link-centric approach and suggests a useful resource for annotating the functions and phenotypic outcomes of proteins.11Ysciescopu
Origin of synchronized traffic flow on highways and its dynamic phase transitions
We study the traffic flow on a highway with ramps through numerical
simulations of a hydrodynamic traffic flow model. It is found that the presence
of the external vehicle flux through ramps generates a new state of recurring
humps (RH). This novel dynamic state is characterized by temporal oscillations
of the vehicle density and velocity which are localized near ramps, and found
to be the origin of the synchronized traffic flow reported recently [PRL 79,
4030 (1997)]. We also argue that the dynamic phase transitions between the free
flow and the RH state can be interpreted as a subcritical Hopf bifurcation.Comment: 4 pages, source TeX file and 4 figures are tarred and compressed via
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