We show that a particular free-by-cyclic group G has CAT(0) dimension equal to 2, but CAT(-1) dimension equal to 3. Starting from a fixed presentation 2-complex we define a family of non-positively curved piecewise Euclidean “model” spaces for G, and show that whenever the group acts properly by isometries on any proper 2-dimensional CAT(0) space X there exists a Gequivariant map from the unive...

Mammalian coat patterns (e.g., spots, stripes) are hypothesized to play important roles in camouflage and other relevant processes, yet the genetic and developmental bases for these phenotypes are completely unknown. The domestic cat, with its diversity of coat patterns, is an excellent model organism to investigate these phenomena. We have established three independent pedigrees to map the fou...

We present a numerical method for calculation of Ruelle-Pollicott resonances of dynamical systems. It constructs an effective coarse-grained propagator by considering the correlations of multiple observables over multiple timesteps. The method is compared to the usual approaches on the example of the perturbed cat map and is shown to be numerically efficient and robust. PACS numbers: 05.45.-a,9...

In mammals, topographic maps emerge from initially diffuse projections during development. To gain insight into the mechanisms governing the transition from a diffuse projection to a topographic map, we studied topographic specificity of functional connections during development, using the cat corticorubral system as a model. In the adult cat, rubrospinal neurons in the dorsomedial part of the ...

Today, hardware chip design with FPGA implementation for designing secure crypto processor is a growing topic due to rapidly increasing attack on digital images over internet network. In this paper, an FPGA implementation of Chaotic Map based two phase image encryption technique is proposed. First phase consists of pixel position permutation and second phase consists of bit value position permu...

This paper presents an efficient block-wise image encryption method based on multiple chaotic maps. The image is divided into four overlapping blocks and each block is permutated with Cat map and its parameters are controlled by Henon map using multiple keys. Due to overlapping division of blocks, it produces effect of double permutation in the middle portion of overlapped image in single permu...

The Pollicott-Ruelle resonances for the sawtooth map are investigated. We turn our attention to the parametric dependence of them with respect to the bifurcation parameter K. It is numerically shown that the resonances move in an erratic way if the bifurcation parameter K is supposed to be time. At certain rational values of K, it is observed that some resonances shrink to z=0. In particular, a...

The neuroanatomical data given here reveal a dense projection from the rostral pole of the cat inferior colliculus (rpIC) to the superior colliculus (SC). A portion of this pathway distributes in 'patches' across the ventral portion of the intermediate grey layer. These finding suggest that the rpIC input to the SC might play a role in determining the auditory receptive fields of SGI neurons an...

The authors have used generalised Galois Theory to construct a homotopy double groupoid of a surjective fibration of Kan simplicial sets. Here we apply this to construct a new homotopy double groupoid of a map of spaces, which includes constructions by others of a 2-groupoid, cat-group or crossed module. An advantage of our construction is that the double groupoid can give an algebraic model of...

We characterize the size and complexity of the mammalian cortices of human, macaque, cat, rat, and mouse. We map the cortical structure onto a Bayesian confidence propagating neural network (BCPNN). An architectural structure for the implementation of the BCPNN based on hypercolumnar modules is suggested. The bandwidth, memory, and computational demands for real-time operation of the system are...