Spectral Properties and Synchronization in Coupled Map Lattices

Spectral properties of Coupled Map Lattices are described. Conditions for the stability of spatially homogeneous chaotic solutions are derived using linear stability analysis. Global stability analysis results are also presented. The analytical results are supplemented with numerical examples. The quadratic map is used for the site dynamics with different coupling schemes such as global coupling, nearest neighbor coupling, intermediate range coupling, random coupling, small world coupling and scale free coupling.Comment: 10 pages with 15 figures (Postscript), REVTEX format. To appear in PR

Wavelength doubling bifurcations in coupled map lattices

We report an interesting phenomenon of wavelength doubling bifurcations in the model of coupled (logistic) map lattices. The temporal and spatial periods of the observed patterns undergo successive period doubling bifurcations with decreasing coupling strength. The universality constants α and δ appear to be the same as in the case of period doubling route to chaos in the uncoupled logistic map. The analysis of the stability matrix shows that period doubling bifurcation occurs when an eigenvalue whose eigenvector has a structure with doubled spatial period exceeds unity

Wavelength-doubling bifurcations in one-dimensional coupled logistic maps

We discuss in detail the interesting phenomenon of wavelength-doubling bifurcations in the model of coupled-map lattices reported earlier [Phys. Rev. Lett. 70, 3408 (1993)]. We take nearest-neighbor coupling of logistic maps on a one-dimensional lattice. With the value of the parameter of the logistic map, μ , corresponding to the period-doubling attractor, we see that the wavelength and the temporal period of the observed pattern undergo successive wavelength- and period-doubling bifurcations with decreasing coupling strength ε. The universality constants α and δ appear to be the same as in the case of the period-doubling route to chaos in the uncoupled logistic map. The phase diagram in the ε -μ plane is investigated. For large values of μ and large periods, regions of instability are observed near the bifurcation lines. We also investigate the mechanism for the wavelength-doubling bifurcations to occur. We find that such bifurcations occur when the eigenvalue of the stability matrix corresponding to the eigenvector with periodicity of twice the wavelength exceeds unity in magnitude

Molecular cloning and characterization of glucose transporter 1 (glut1) and citrate synthase cDNA in buffalo (Bubalus bubalis)

Glucose transporter type-1 (glut1) and citrate synthase plays crucial role in glucose transport and regulation of tricarboxylic acid cycle (TCA) cycle in mammalian energy metabolism. The present study was aimed to clone and characterize glut1 and citrate synthase cDNA in water buffalo (Bubalus bubalis). Total of 90 cumulus oocyte complexes (COCs) were used for mRNA isolation and reverse transcribed to cDNA, which was further used in polymerase chain reaction (PCR) amplification of glut1 and citrate synthase. PCR products of glut1 and citrate synthase were cloned by T/A cloning using pGEM-T easy vector and further  sequenced. Gene sequence analysis of glut1 and citrate synthase revealed that they have open reading frame of 1479 (encoding 492 aa) and 1401 bp (encoding 466 aa), respectively. Further phylogenic analysis of gene and deduced amino acid sequences suggests that bubaline glut1 shares ∼ 89 to 98% and ∼ 97 to 99% similarity at nucleotide and amino acid level respectively  whereas citrate synthase shared ∼ 89 to 99% at nucleotide and ∼ 96 to 99% at amino acid level respectively with other domestic species and human. Predicted protein structures of buffalo glut1 protein accentuate the presence of crucial amino acids involved in glucose transport moreover the essential catalytic residues are highly conserved in buffalo citrate synthase.Keywords: Buffalo, cloning, characterization, Glut1, citrate synthase

Spatially periodic orbits in coupled-map lattices

We obtain the conditions that ensure the stability of spatially and temporally periodic orbits of coupled-map lattices. The stability matrices can be put in a circulant and block circulant form. This allows us to reduce the problem to smaller matrices corresponding to the building blocks of spatial periodicity. We find that additional conditions are imposed as we expand the size of the lattice. For the traveling-wave solution the analysis is considerably simplified. We have analyzed both the one-dimensional and higher-dimensional lattices

Stability of a neural network model with small-world connections

Small-world networks are highly clustered networks with small distances among the nodes. There are many biological neural networks that present this kind of connections. There are no special weightings in the connections of most existing small-world network models. However, this kind of simply-connected models cannot characterize biological neural networks, in which there are different weights in synaptic connections. In this paper, we present a neural network model with weighted small-world connections, and further investigate the stability of this model.Comment: 4 pages, 3 figure

TOF-Brho Mass Measurements of Very Exotic Nuclides for Astrophysical Calculations at the NSCL

Atomic masses play a crucial role in many nuclear astrophysics calculations. The lack of experimental values for relevant exotic nuclides triggered a rapid development of new mass measurement devices around the world. The Time-of-Flight (TOF) mass measurements offer a complementary technique to the most precise one, Penning trap measurements, the latter being limited by the rate and half-lives of the ions of interest. The NSCL facility provides a well-suited infrastructure for TOF mass measurements of very exotic nuclei. At this facility, we have recently implemented a TOF-Brho technique and performed mass measurements of neutron-rich nuclides in the Fe region, important for r-process calculations and for calculations of processes occurring in the crust of accreting neutron stars.Comment: 8 pages, 4 figures, submitted to Journal of Physics G, proceedings of Nuclear Physics in Astrophysics II

Spectroscopy of neutron-unbound 27,28^{27,28}F

The ground state of $^{28}$F has been observed as an unbound resonance $2\underline{2}0$ keV above the ground state of $^{27}$F. Comparison of this result with USDA/USDB shell model predictions leads to the conclusion that the $^{28}$F ground state is primarily dominated by $sd$-shell configurations. Here we present a detailed report on the experiment in which the ground state resonance of $^{28}$F was first observed. Additionally, we report the first observation of a neutron-unbound excited state in $^{27}$F at an excitation energy of $25\underline{0}0 (2\underline{2}0)$ keV.Comment: 10 pages, 11 figures, Accepted for publication in Phys. Rev.

Octupole strength in the neutron-rich calcium isotopes

Low-lying excited states of the neutron-rich calcium isotopes $^{48-52}$Ca have been studied via $\gamma$-ray spectroscopy following inverse-kinematics proton scattering on a liquid hydrogen target using the GRETINA $\gamma$-ray tracking array. The energies and strengths of the octupole states in these isotopes are remarkably constant, indicating that these states are dominated by proton excitations.Comment: 15 pages, 3 figure