Search results for "Matrix"
showing 10 items of 3205 documents
Carboxylated-xyloglucan and peptide amphiphile co-assembly in wound healing.
2021
Abstract Hydrogel wound dressings can play critical roles in wound healing protecting the wound from trauma or contamination and providing an ideal environment to support the growth of endogenous cells and promote wound closure. This work presents a self-assembling hydrogel dressing that can assist the wound repair process mimicking the hierarchical structure of skin extracellular matrix. To this aim, the co-assembly behaviour of a carboxylated variant of xyloglucan (CXG) with a peptide amphiphile (PA-H3) has been investigated to generate hierarchical constructs with tuneable molecular composition, structure, and properties. Transmission electron microscopy and circular dichroism at a low c…
Cloning, purification, and nucleotide-binding traits of the catalytic subunit A of the V1VO ATPase from Aedes albopictus.
2007
The Asian tiger mosquito, Aedes albopictus, is commonly infected by the gregarine parasite Ascogregarina taiwanensis, which develops extracellularly in the midgut of infected larvae. The intracellular trophozoites are usually confined within a parasitophorous vacuole, whose acidification is generated and controlled by the V(1)V(O) ATPase. This proton pump is driven by ATP hydrolysis, catalyzed inside the major subunit A. The subunit A encoding gene of the Aedes albopictus V(1)V(O) ATPase was cloned in pET9d1-His(3) and the recombinant protein, expressed in the Escherichia coli Rosetta 2 (DE3) strain, purified by immobilized metal affinity- and ion-exchange chromatography. The purified prote…
One-Sided Prototype Selection on Class Imbalanced Dissimilarity Matrices
2012
In the dissimilarity representation paradigm, several prototype selection methods have been used to cope with the topic of how to select a small representation set for generating a low-dimensional dissimilarity space. In addition, these methods have also been used to reduce the size of the dissimilarity matrix. However, these approaches assume a relatively balanced class distribution, which is grossly violated in many real-life problems. Often, the ratios of prior probabilities between classes are extremely skewed. In this paper, we study the use of renowned prototype selection methods adapted to the case of learning from an imbalanced dissimilarity matrix. More specifically, we propose the…
Fast Matrix Multiplication
2015
Until a few years ago, the fastest known matrix multiplication algorithm, due to Coppersmith and Winograd (1990), ran in time O(n2.3755). Recently, a surge of activity by Stothers, Vassilevska-Williams, and Le~Gall has led to an improved algorithm running in time O(n2.3729). These algorithms are obtained by analyzing higher and higher tensor powers of a certain identity of Coppersmith and Winograd. We show that this exact approach cannot result in an algorithm with running time O(n2.3725), and identify a wide class of variants of this approach which cannot result in an algorithm with running time $O(n^{2.3078}); in particular, this approach cannot prove the conjecture that for every e > 0, …
Filtering design for two-dimensional Markovian jump systems with state-delays and deficient mode information
2014
This paper is concerned with the problem of H"~ filtering for a class of two-dimensional Markovian jump linear systems described by the Fornasini-Marchesini local state-space model. The systems under consideration are subject to state-delays and deficient mode information in the Markov chain. The description of deficient mode information is comprehensive that simultaneously includes the exactly known, partially unknown and uncertain transition probabilities. By invoking the properties of the transition probability matrix, together with the convexification of uncertain domains, a new H"~ performance analysis criterion for the filtering error system is firstly derived. Then, via some matrix i…
Dynamical Models of Interrelation in a Class of Artificial Networks
2020
The system of ordinary differential equations that models a type of artificial networks is considered. The system consists of a sigmoidal function that depends on linear combinations of the arguments minus the linear part. The linear combinations of the arguments are described by the regulatory matrix W. For the three-dimensional cases, several types of matrices W are considered and the behavior of solutions of the system is analyzed. The attractive sets are constructed for most cases. The illustrative examples are provided. The list of references consists of 12 items.
Positivity, complex FIOs, and Toeplitz operators
2018
International audience; We establish a characterization of complex linear canonical transformations that are positive with respect to a pair of strictly plurisubharmonic quadratic weights. As an application, we show that the boundedness of a class of Toeplitz operators on the Bargmann space is implied by the boundedness of their Weyl symbols.
Stability of genetic regulatory networks with time-varying delay: Delta operator method
2015
This paper investigates the stability problem for a class of uncertain genetic regulatory networks (GRNs) with time-varying delay via delta operator approach. Both the parameter uncertainty and the generalized activations are considered in the model under study. By constructing an appropriate Lyapunov-Krasovskii functional, the stability and robust stability conditions of GRNs are presented under the delta operator frame. These conditions can be expressed in terms of linear matrix inequalities (LMIs). Finally, a numerical example is employed to illustrate the effectiveness of the proposed results.
Generation of Certain Matrix Groups by Three Involutions, Two of Which Commute
1997
Ž . We say that a group is 2, 2 = 2 -generated if it can be generated by three involutions, two of which commute. The problem of determining Ž . which finite simple groups are 2, 2 = 2 -generated was posed by Mazurov w x in 1980 in the Kourovka notebook 3 . An answer to this problem, for some classes of finite simple groups, was given by Ya. N. Nuzhin, namely for w x Chevalley groups of rank 1 in 4 , for Chevalley groups over a field of w x characteristic 2 in 5 , and for the alternating groups and Chevalley groups w x of type A in 6 . In this paper we consider the problem in the more n general context of matrix groups over arbitrary, finitely generated, commutative rings. As a special case…
Analytic high-order Douglas–Kroll–Hess electric field gradients
2007
In this work we present a comprehensive study of analytical electric field gradients in hydrogen halides calculated within the high-order Douglas-Kroll-Hess (DKH) scalar-relativistic approach taking picture-change effects analytically into account. We demonstrate the technical feasibility and reliability of a high-order DKH unitary transformation for the property integrals. The convergence behavior of the DKH property expansion is discussed close to the basis set limit and conditions ensuring picture-change-corrected results are determined. Numerical results are presented, which show that the DKH property expansion converges rapidly toward the reference values provided by four-component met…