A class
of rotaxane is created, not by encapsulating a conventional
linear thread, but rather by wrapping a large cucurbit[10]uril macrocycle
about a three-dimensional, cylindrical, nanosized, self-assembled
supramolecular helicate as the axle. The resulting pseudo-rotaxane
is readily converted into a proper interlocked rotaxane by adding
branch points to the helicate strands that form the surface of the
cylinder (like branches and roots on a tree trunk). The supramolecular
cylinder that forms the axle is itself a member of a unique and remarkable
class of helicate metallo-drugs that bind Y-shaped DNA junction structures
and induce cell death. While pseudo-rotaxanation does not modify the
DNA-binding properties, proper, mechanically-interlocked rotaxanation
transforms the DNA-binding and biological activity of the cylinder.
The ability of the cylinder to de-thread from the rotaxane (and thus
to bind DNA junction structures) is controlled by the extent of branching:
fully-branched cylinders are locked inside the cucurbit[10]uril macrocycle,
while cylinders with incomplete branch points can de-thread from the
rotaxane in response to competitor guests. The number of branch points
can thus afford kinetic control over the drug de-threading and release.
In this paper, an overall framework for crowd analysis is presented. Detection and tracking of pedestrians as well as detection of dense crowds is performed on image sequences to improve simulation models of pedestrian flows. Additionally, graph-based event detection is performed by using Hidden Markov Models on pedestrian trajectories utilizing knowledge from simulations.Experimental results show the benefit of our integrated framework using simulation and real-world data for crowd analysis.
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