Robust H∞ feedback control for uncertain stochastic delayed genetic regulatory networks with additive and multiplicative noise

The official published version can found at the link below.Noises are ubiquitous in genetic regulatory networks (GRNs). Gene regulation is inherently a stochastic process because of intrinsic and extrinsic noises that cause kinetic parameter variations and basal rate disturbance. Time delays are usually inevitable due to different biochemical reactions in such GRNs. In this paper, a delayed stochastic model with additive and multiplicative noises is utilized to describe stochastic GRNs. A feedback gene controller design scheme is proposed to guarantee that the GRN is mean-square asymptotically stable with noise attenuation, where the structure of the controllers can be specified according to engineering requirements. By applying control theory and mathematical tools, the analytical solution to the control design problem is given, which helps to provide some insight into synthetic biology and systems biology. The control scheme is employed in a three-gene network to illustrate the applicability and usefulness of the design.This work was funded by Royal Society of the U.K.; Foundation for the Author of National Excellent Doctoral Dissertation of China. Grant Number: 2007E4; Heilongjiang Outstanding Youth Science Fund of China. Grant Number: JC200809; Fok Ying Tung Education Foundation. Grant Number: 111064; International Science and Technology Cooperation Project of China. Grant Number: 2009DFA32050; University of Science and Technology of China Graduate Innovative Foundation

LaFeAsO1−x_{1-x}Fx_x: A low carrier density superconductor near itinerant magnetism

Density functional studies of 26K superconducting LaFeAs(O,F) are reported. We find a low carrier density, high density of states, $N(E_F)$ and modest phonon frequencies relative to $T_c$. The high $N(E_F)$ leads to proximity to itinerant magnetism, with competing ferromagnetic and antiferromagnetic fluctuations and the balance between these controlled by doping level. Thus LaFeAs(O,F) is in a unique class of high $T_c$ superconductors: high $N(E_F)$ ionic metals near magnetism.Comment: Shortened published form. Typos correcte

Comment on "Self-Purification in Semiconductor Nanocrystals"

In a recent Letter [PRL 96, 226802 (2006)], Dalpian and Chelikowsky claimed that formation energies of Mn impurities in CdSe nanocrystals increase as the size of the nanocrystal decreases, and argued that this size dependence leads to "self-purification" of small nanocrystals. They presented density-functional-theory (DFT) calculations showing a strong size dependence for Mn impurity formation energies, and proposed a general explanation. In this Comment we show that several different DFT codes, pseudopotentials, and exchange-correlation functionals give a markedly different result: We find no such size dependence. More generally, we argue that formation energies are not relevant to substitutional doping in most colloidally grown nanocrystals.Comment: 1 page, 1 figur

CP violation for neutral charmed meson decays to CP eigenstates

CP asymmetries for neutral charmed meson decays to CP eigenstates are carefully studied. The formulas and numerical results are presented. The impact on experiments is briefly discussed.Comment: 7 pages, 1 figure, 1 table, Revte

In silico approach to identification of a novel gene responsive to submergence stress in rice

Submergence is one of the major constraints to rice production. Bioinformatics approach has been widely used to identify candidate genes on many biological aspects. In the present study, a novel gene involved in submergence stress in rice, Os07g47670 was identified by in silico approach. The amino acid sequence of Os07g47670 is highly homologous to hypoxia-responsive family proteins. No disordered regions are found in the Os07g47670 protein. In the Os07g47670 gene promoter, there are two ARE cis-regulatory elements, indicating that Os07g47670 is associated with submergence responsiveness. The Os07g47670 transcript levels are higher in roots of one or two-week old plants than in other tissues. Without the Sub1A gene, the expression level of Os07g47670 in M202 is low under submergence, ACC treatment, and normal condition. However, in the Sub1A genetic background, the Os07g47670 transcript level is strongly induced during submergence, and peaked at day 1 during submergence. The mRNA level of Os07g47670 in M202(Sub1A) was also significantly increased by ACC treatment. High expression level of Os07g47670 is correlated with the existence of the Sub1A gene. Os07g47670 shares similar expression patterns with Sub1A, ADH1, SLR1, and SLRL1 and are co-induced under submergence. Thus, we have documented Os07g47670 as a novel gene associated with submergence stress response. The identification of Os07g47670 will facilitate the understanding of the molecular mechanism of submergence tolerance in rice.Key words: Rice (Oryza sativa L.), in silico approach, submergence, waterlogging

Nonclassical paths in the recurrence spectrum of diamagnetic atoms

Using time-independent scattering matrices, we study how the effects of nonclassical paths on the recurrence spectra of diamagnetic atoms can be extracted from purely quantal calculations. This study reveals an intimate relationship between two types of nonclassical paths: exotic ghost orbits and diffractive orbits. This relationship proves to be a previously unrecognized reason for the success of semiclassical theories, like closed-orbit theory, and permits a comprehensive reformulation of the semiclassical theory that elucidates its convergence properties.Comment: 5 pages, 4 figure