A flexible and adaptive Simpler GMRES with deflated restarting for shifted linear systems

In this paper, two efficient iterative algorithms based on the simpler GMRES method are proposed for solving shifted linear systems. To make full use of the shifted structure, the proposed algorithms utilizing the deflated restarting strategy and flexible preconditioning can significantly reduce the number of matrix-vector products and the elapsed CPU time. Numerical experiments are reported to illustrate the performance and effectiveness of the proposed algorithms.Comment: 17 pages. 9 Tables, 1 figure; Newly update: add some new numerical results and correct some typos and syntax error

Solutions of a Quadratic Inverse Eigenvalue Problem for Damped Gyroscopic Second-Order Systems

Given k pairs of complex numbers and vectors (closed under conjugation), we consider the inverse quadratic eigenvalue problem of constructing n×n real matrices M, D, G, and K, where M>0, K and D are symmetric, and G is skew-symmetric, so that the quadratic pencil Q(λ)=λ2M+λ(D+G)+K has the given k pairs as eigenpairs. First, we construct a general solution to this problem with k≤n. Then, with the special properties D=0 and K<0, we construct a particular solution. Numerical results illustrate these solutions

{μ-trans-N,N′-Bis[(diphenyl­phosphan­yl)meth­yl]benzene-1,4-diamine-κ2 P:P′}bis­{(acetonitrile-κN)[dipyrido[3,2-a:2′,3′-c]phenazine-κ2 N 4,N 5]copper(I)} bis­(tetra­fluoridoborate)

In the centrosymmetric dinuclear title compound, [Cu2(C2H3N)2(C18H10N4)2(C32H30N2P2)](BF4)2, the CuI centre is coordinated by two N atoms from a dipyridophenazine ligand, one P atom from an N,N′-bis­[(diphenyl­phosphan­yl)meth­yl]benzene-1,4-diamine (bpbda) ligand, and one N atom from an acetonitrile mol­ecule in a distorted tetra­hedral geometry. The bpbda ligand, lying on an inversion center, bridges two CuI centres into a Z-shaped complex. Intra­molecular π–π inter­actions between the dipyridophenazine ligand and the benzene ring of the bpbda ligand are observed [centroid–centroid distance = 3.459 (3) Å]. The crystal structure also involves inter­molecular π–π inter­actions between the dipyridophenazine ligands [centroid–centroid distance = 3.506 (3) Å], which lead to a one-dimensional supra­molecular structure

Bis[4-(2-hydroxy­benzyl­ideneamino)benzoato-κO]tetrakis­(methanol-κO)manganese(II)

In the title mononuclear complex, [Mn(C14H10NO3)2(CH3OH)4], the MnII atom, lying on an inversion centre, exhibits a distorted octa­hedral geometry, defined by two O atoms from two monodentate ligands and four O atoms from four methanol mol­ecules. The crystal structure involves intra­molecular O—H⋯N and O—H⋯O and inter­molecular O—H⋯O hydrogen bonds

Antimicrobial peptaibols, novel suppressors of tumor cells, targeted calcium-mediated apoptosis and autophagy in human hepatocellular carcinoma cells

<p>Abstract</p> <p>Background</p> <p>Hepatocellular carcinoma (HCC) is one of the most common cancers in the world which is highly chemoresistant to currently available chemotherapeutic agents. Thus, novel therapeutic targets are needed to be sought for the successful treatment of HCC. Peptaibols, a family of peptides synthesized non-ribosomally by the <it>Trichoderma </it>species and other fungi, exhibit antibiotic activities against bacteria and fungi. Few studies recently showed that peptaibols exerted cytotoxicity toward human lung epithelial and breast carcinoma cells. However, the mechanism involved in peptaibol-induced cell death remains poorly understood.</p> <p>Results</p> <p>Here, we showed that Trichokonin VI (TK VI), a peptaibol from <it>Trichoderma pseudokoningii </it>SMF2, induced growth inhibition of HCC cells in a dose-dependent manner. It did not obviously impair the viability of normal liver cells at lower concentration. Moreover, the suppression of cell viability resulted from the programmed cell death (PCD) with characteristics of apoptosis and autophagy. An influx of Ca²⁺triggered the activation of μ-calpain and proceeded to the translocation of Bax to mitochondria and subsequent promotion of apoptosis. On the other hand, typically morphological characteristics consistent with autophagy were also observed by punctate distribution of MDC staining and the induction of LC3-II, including extensive autophagic vacuolization and enclosure of cell organelles by these autophagosomes. More significantly, specific depletion of Bak expression by small RNA interfering (siRNA) could partly attenuate TK VI-induced autophagy. However, siRNA against Bax led to increased autophagy.</p> <p>Conclusion</p> <p>Taken together, these findings showed for the first time that peptaibols were novel regulators involved in both apoptosis and autophagy, suggesting that the class of peptaibols might serve as potential suppressors of tumor cells.</p

Neural Adaptive Decentralized Coordinated Control with Fault-Tolerant Capability for DFIGs under Stochastic Disturbances

At present, most methodologies proposed to control over double fed induction generators (DFIGs) are based on single machine model, where the interactions from network have been neglected. Considering this, this paper proposes a decentralized coordinated control of DFIG based on the neural interaction measurement observer. An artificial neural network is employed to approximate the nonlinear model of DFIG, and the approximation error due to neural approximation has been considered. A robust stabilization technique is also proposed to override the effect of approximation error. A H2 controller and a H∞ controller are employed to achieve specified engineering purposes, respectively. Then, the controller design is formulated as a mixed H2/H∞ optimization with constrains of regional pole placement and proportional plus integral (PI) structure, which can be solved easily by using linear matrix inequality (LMI) technology. The results of simulations are presented and discussed, which show the capabilities of DFIG with the proposed control strategy to fault-tolerant control of the maximum power point tracking (MPPT) under slight sensor faults, low voltage ride-through (LVRT), and its contribution to power system transient stability support

The complete genome of Zunongwangia profunda SM-A87 reveals its adaptation to the deep-sea environment and ecological role in sedimentary organic nitrogen degradation

<p>Abstract</p> <p>Background</p> <p><it>Zunongwangia profunda </it>SM-A87, which was isolated from deep-sea sediment, is an aerobic, gram-negative bacterium that represents a new genus of <it>Flavobacteriaceae</it>. This is the first sequenced genome of a deep-sea bacterium from the phylum <it>Bacteroidetes</it>.</p> <p>Results</p> <p>The <it>Z. profunda </it>SM-A87 genome has a single 5 128 187-bp circular chromosome with no extrachromosomal elements and harbors 4 653 predicted protein-coding genes. SM-A87 produces a large amount of capsular polysaccharides and possesses two polysaccharide biosynthesis gene clusters. It has a total of 130 peptidases, 61 of which have signal peptides. In addition to extracellular peptidases, SM-A87 also has various extracellular enzymes for carbohydrate, lipid and DNA degradation. These extracellular enzymes suggest that the bacterium is able to hydrolyze organic materials in the sediment, especially carbohydrates and proteinaceous organic nitrogen. There are two clustered regularly interspaced short palindromic repeats in the genome, but their spacers do not match any sequences in the public sequence databases. SM-A87 is a moderate halophile. Our protein isoelectric point analysis indicates that extracellular proteins have lower predicted isoelectric points than intracellular proteins. SM-A87 accumulates organic osmolytes in the cell, so its extracelluar proteins are more halophilic than its intracellular proteins.</p> <p>Conclusion</p> <p>Here, we present the first complete genome of a deep-sea sedimentary bacterium from the phylum <it>Bacteroidetes</it>. The genome analysis shows that SM-A87 has some common features of deep-sea bacteria, as well as an important capacity to hydrolyze sedimentary organic nitrogen.</p