At the end of the last century, H. Poincar e 7] discovered the phenomenon of sepa-ratrices splitting, which now seems to be the main cause of the stochastic behavior in Hamiltonian systems. He formulated a general problem of Dynamics as a perturbation of an integrable Hamiltonian system

During development, many neural stem cells "age" as they sequentially generate distinct neuronal or glial cell types. In this issue, Maurange et al. (2008) now identify the temporal control factors in Drosophila neural stem cells (neuroblasts) that regulate the fate of stem cell progeny and signal the end of stem cell proliferation.

Recently, manganese-oxide compounds have attracted considerable attention, in particular, as candidate materials for photochemical water-splitting reactions. Here, we investigate electronic states of pristine manganese dioxides (MnO2) in different crystal phases using spin-polarized density functional theory (DFT) with Hubbard U correction. Geometrical structures and band dispersions of α-, β-,...

There is great interest worldwide in discovering and developing a permanent source of tissues which would be capable of generating any cell type and which would avoid the problem of transplant rejection. Stem cells are cells that can specialize into the many different cells found in the human body. The ethical objections concerning stem cells have focused primarily on their source. Human embry...

In this channel,we study rate region of a Gaussian two-way diamond channel which operates in half-duplex mode. In this channel, two transceiver (TR) nodes exchange their messages with the help of two relay nodes. We consider a special case of the Gaussian two-way diamond channels which is called Compute-and-Forward Multiple Access Channel (CF-MAC). In the CF-MAC, the TR nodes transmit their mes...

We present a syllable bigram model for segmenting a Korean sentence into words and correcting word-spacing errors in the spelling checker. We evaluated the system’s performance for automatic word segmentation, word-spacing error detection, and the word-splitting problem of the character recognition system at the end of a line.

We tackle the numerical simulation of reaction-diffusion equations modeling multiscale reaction waves. This type of problems induces peculiar difficulties and potentially large stiffness which stem from the broad spectrum of temporal scales in the nonlinear chemical source term as well as from the presence of steep spatial gradients in the reaction fronts, spatially very localized. In this pape...