bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and validation of gas chromatography and real‐time quantitative PCR for the quantification of landscape‐scale gene flow from varieties of high erucic acid (HEAR) oilseed rape
Authors: Cullen Danny W , Squire Geoffrey R , McNicol Jim W , Jacobs Jennifer H , Osborne Juliet L , Ford Linda , Ramsay Gavin , Scrimgeour Charlie , Young Mark W 
Published: September 2008

AbstractBACKGROUND: High erucic acid oilseed rape (HEAR) was tested as a source crop for estimates of regional geneflow. Two methods to detect HEAR in low erucic acid oilseed rape (LEAR) were compared: real‐time quantitative PCR (qPCR) and gas chromatography (GC).RESULTS: Fields (2.5 ha) of a LEAR variety (0.028% EA) in Tayside and Hertfordshire were juxtaposed adjacent to and 1 km distant from a HEAR (44% EA) field. The LEAR variety was a varietal association to ensure high cross‐pollination (CP). The methods were highly correlated, measuring between 30% and 0.5% CP. However, the qPCR method became unreliable below 0.5% CP, whereas GC was robust enough to detect raised EA equivalent to one F1 seed in 500 (0.2%). A statistical mixture model was fitted to the distributions of EA in samples in order to assign a CP value to each 500‐seed sample. Declines of CP from 30% to < 1%, and EA from 5% to 0.2%, with distance up to 150 m in the near fields was best fitted with a power function. The combined mean EA for both far fields was 0.11%, well above the background LEAR value of 0.028%, and mean CP was 0.36%.CONCLUSIONS: The GC method of detection raised %EA should be a reliable and high‐throughput means of estimating %CP between fields, provided the %EA of single F1 seed in receptor fields is measured to confirm the presence of F1 seed. Copyright © 2008 Society of Chemical Industry
On realization of the Kreĭn–Langer class Nκ of matrix‐valued functions in Pontryagin spaces
Authors: Arlinskiĭ Yury , Belyi Sergey , Derkach Vladimir , Tsekanovskii Eduard 
Published: September 2008

AbstractIn this paper the realization problems for the Kreĭn–Langer class Nκ of matrix‐valued functions are being considered. We found the criterion when a given matrix‐valued function from the class Nκ can be realized as linear‐fractional transformation of the transfer function of canonical conservative system of the M. Livsic type (Brodskii–Livsic rigged operator colligation) with the main operator acting on a rigged Pontryagin space Πκ with indefinite metric. We specify three subclasses of the class Nκ (R) of all realizable matrix‐valued functions that correspond to different properties of a realizing system, in particular, when the domains of the main operator of a system and its conjugate coincide, when the domain of the hermitian part of a main operator is dense in Πκ . Alternatively we show that the class Nκ (R) can be realized as transfer matrix‐functions of some canonical impedance systems with self‐adjoint main operators in rigged spaces Πκ . The case of scalar functions of the class Nκ (R) is considered in details and some examples are presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Atomic decompositions of function spaces with Muckenhoupt weights, and some relation to fractal analysis
Authors: Haroske Dorothee D. , Piotrowska Iwona 
Published: September 2008

AbstractThis paper deals with atomic decompositions in spaces of type Bsp,q (ℝn , w), Fsp,q (ℝn , w), 0 < p < ∞, 0 < q ≤ ∞, s ∈ ℝ, where the weight function w belongs to some Muckenhoupt class Ar. In particular, we consider the weight function wΓκ (x) = dist(x, Γ)κ, where Γ is some d ‐set, 0 < d < n, and κ > –(n – d). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the existence of a solution for a model of stem cell differentiation
Authors: Witterstein Gabriele 
Published: September 2008

AbstractIn two dimensions we consider a model describing the biological material change in the process of stem cell differentiation. The arising system consists in the Navier–Stokes equations for viscous, compressible, isothermal flow and models a creep movement mainly caused by a mass production and affected by the changeover in the stem cell culture. These equations are coupled with an Allen–Cahn equation modeling the solidification of a liquid. As the main result, we show the existence of a weak, spherically symmetric solution in a plain domain. Copyright © 2008 John Wiley & Sons, Ltd.
Diffusion tensor imaging of left ventricular remodeling in response to myocardial infarction in the mouse
Authors: Strijkers Gustav J. , Bouts Annemiek , Blankesteijn W. Matthijs , Peeters Tim H. J. M. , Vilanova Anna , van Prooijen Mischa C. , Sanders Honorius M. H. F. , Heijman Edwin , Nicolay Klaas 
Published: September 2008

AbstractThe cardiac muscle architecture lies at the basis of the mechanical and electrical properties of the heart, and dynamic alterations in fiber structure are known to be of prime importance in healing and remodeling after myocardial infarction. In this study, left ventricular remodeling was characterized using diffusion tensor imaging (DTI) in a mouse model of myocardial infarction. Myocardial infarction was induced in mice by permanent ligation of the left anterior descending coronary artery. Serial ex vivo DTI measurements were performed 7, 14, 28, and 60 days after ligation. Apparent diffusion coefficient, fractional anisotropy, the three eigenvalues of the diffusion tensor, and the myofiber disarray served as readout parameters. After myocardial infarction, the mouse hearts displayed extreme wall thinning in the infarcted area, which covered large parts of the apex and extended into the free wall up to the equator. Average heart mass increased by 70% 7–60 days after infarction. Histological analysis showed that the infarct at 7 days consisted of unstructured tissue with residual necrosis and infiltration of macrophages and myofibroblasts. At 14 days after infarction, the necrotic tissue had disappeared and collagen fibers were starting to appear. From 28 to 60 days, the infarct had fully developed into a mature scar. DTI parameters showed dynamic changes as a function of time after infarction. The apparent diffusion coefficient in the infarcted region was lower than in remote regions and increased as a function of time after infarction. The fractional anisotropy was higher in the infarcted region and was maximum at 28 days, which was attributed to the development of structured collagen fibers. Myofiber disarray, which was analyzed by considering the alignment of fibers in neighboring voxels, was significantly higher in infarcted regions. DTI provides a valuable non‐destructive tool for characterizing structural remodeling in diseased myocardium. Copyright © 2008 John Wiley & Sons, Ltd.
The stability of stars of triangular equilibrium plate elements
Authors: Maunder E. A. W. , Moitinho de Almeida J. P. 
Published: September 2008

AbstractEquilibrium models for finite element analyses are becoming increasingly important in complementary roles to those from conventional conforming models, but when formulating equilibrium models questions of stability, or admissibility of loads, are of major concern. This paper addresses these questions in the context of flat plates modelled with triangular hybrid elements involving membrane and/or flexural actions. Patches of elements that share a common vertex are considered, and such patches are termed stars. Stars may be used in global analyses as assemblies of elements forming macro‐elements, or in local analyses. The conditions for stability, or the existence and number of spurious kinematic modes, are determined in a general algebraic procedure for any degree of the interpolation polynomials and for any geometric configuration. The procedure involves the determination of the rank of a compatibility matrix by its transformation to row echelon form. Examples are presented to illustrate some of the characteristics of spurious kinematic modes when they exist in stars with open or closed links. Copyright © 2008 John Wiley & Sons, Ltd.
A three‐dimensional C1 finite element for gradient elasticity
Authors: Papanicolopulos S.‐A. , Zervos A. , Vardoulakis I. 
Published: September 2008

AbstractIn gradient elasticity strain gradient terms appear in the expression of virtual work, leading to the need for C1 continuous interpolation in finite element discretizations of the displacement field only. Employing such interpolation is generally avoided in favour of the alternative methods that interpolate other quantities as well as displacement, due to the scarcity of C1 finite elements and their perceived computational cost. In this context, the lack of three‐dimensional C1 elements is of particular concern. In this paper we present a new C1 hexahedral element which, to the best of our knowledge, is the first three‐dimensional C1 element ever constructed. It is shown to pass the single element and patch tests, and to give excellent rates of convergence in benchmark boundary value problems of gradient elasticity. It is further shown that C1 elements are not necessarily more computationally expensive than alternative approaches, and it is argued that they may be more efficient in providing good‐quality solutions. Copyright © 2008 John Wiley & Sons, Ltd.
Polyconvex energy densities with applications to anisotropic thin shells
Authors: Balzani D. , Schröder J. , Gruttmann F. 
Published: September 2008

AbstractThis work shows the capability to simulate anisotropic thin shells using polyconvex energy densities by analyzing numerical examples. The variational framework is based on the enhanced assumed strain formulation. The iterative enforcement of the zero normal stress condition at the integration points allows consideration of arbitrary three–dimensional constitutive equations. We consider an additive structure of the energy decoupled in an isotropic part for a matrix material and the superposition of transversely isotropic parts for embedded fiber families and focus on polyconvex strain energy functions. In two representative examples we document anisotropy effects. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Entropy behaviour of evolution PDEs
Authors: Broadbridge P. 
Published: September 2008

AbstractA second order nonlinear conservation equation displays entropy irreversibility if and only if the heat flux is in the direction of decreasing temperature. Unlike linear 4th order diffusion equations, some classes of nonlinear 4th order equations do in fact display entropy irreversibility. In known cases, this is associated with positivity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An alternating direction Galerkin method for elliptic problems with gradient nonlinearity
Authors: Chow S.‐S. 
Published: September 2008

AbstractSeveral problems in many applications involve the solution of partial differential equations with gradient dependent nonlinearity. The numerical solution of the resulting nonlinear system is rather expensive. We present an alternating direction Galerkin method that allows much faster solution of the nonlinear system. The alternating direction formulation help reduce the problem into a sequence of nonlinear systems that may be solved very efficiently. Theoretical study of the convergence of the method will also be presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Matching shape graphs
Authors: Demirci M. Fatih , van Leuken Reinier , Veltkamp Remco 
Published: September 2008

AbstractGraphs are important structures to model complex relationships such as chemical compounds, proteins, geometric or hierarchical parts, and XML documents. Given a query graph, indexing has become a necessity to retrieve similar graphs quickly from large databases. We propose a novel technique for indexing databases, whose entries can be represented as graph structures. Our method starts by representing the topological structure of a graph as well as that of its subgraphs as vectors in which the components correspond to the sorted laplacian eigenvalues of the graph or subgraphs. By doing a nearest neighbor search around the query spectra, similar but not necessarily isomorphic graphs are retrieved. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlocal‐means single‐frame image zooming
Authors: Ebrahimi Mehran , Vrscay Edward R. 
Published: September 2008

AbstractIn this paper we present a novel single‐frame image zooming technique which is inspired by fractal‐based image zooming, example‐based zooming, and nonlocal‐means image denoising and combines these techniques in a consistent and improved framework. In Bayesian terms, this example‐based zooming technique targets the minimum mean square error (MMSE) estimate by learning the posterior directly from examples taken from the image itself at a different scale, similar to fractalbased techniques. The examples are weighted according to a scheme introduced by Buades et al. to perform nonlocal‐means image denoising. Finally, various computational issues are addressed and some results of this image zooming method applied to natural images are presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Asymptotic analysis and relaxation of Mumford‐Shah type energies with obstacles
Authors: Focardi M. 
Published: September 2008

AbstractWe discuss in a model case some results concerning the homogenization and relaxation of free‐discontinuity energies subjected to (unilateral) obstacle conditions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Capillary hydrodynamics of the deposition of thin films and droplets on heterogeneous, porous substrates
Authors: Gerlach D. , Alleborn N. , Raszillier H. , Delgado A. 
Published: September 2008

AbstractThe work presented here deals with recent research on capillary hydrodynamics of thin viscous liquid films and droplets. The process engineering background comes from the industrial process to deposit thin films or droplets on substrates such as polymer foils or paper [1, 2, 3]. During the production of paper, for example, layers of coating color have to be applied onto the raw paper in order to ensure its usability. Ink–jet paper consists of several different functional layers to optimize the paper with regard to printing quality or paper handling. For the printing process by the ink–jet technique, a controlled application of droplets onto the paper and subsequent penetration of the fluid into the paper are crucial for the final quality of the print. The work summarized here considers the application of films or droplets on substrates as well as the flow of liquids inside porous media. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Smoothed aggregation multigrid for incompressible flows
Authors: Janka Aleš 
Published: September 2008

AbstractWe discuss the advantages of using algebraic multigrid based on smoothed aggregation for solving indefinite linear problems. The ingredients of smoothed aggregation are used to construct a black‐box monolithic multigrid method with indefinite coarse problems. Although we discuss some techniques for enforcing the uniform inf‐sup stability on all coarse levels, numerical experiments suggest that it is not strictly necessary. The proposed multigrid preconditioner shows robust behaviour for different time‐step parameters and even for very elongated geometries, where other techniques based on h ‐independent preconditioners of the pressure Schur complement lose their efficiency. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of artificial turbulent fields with prescribed second‐order statistics using the random‐spot method
Authors: Kornev Nikolai , Kröger Hannes , Turnow Johann , Hassel Egon 
Published: September 2008

AbstractThe paper presents a short description of the mathematical procedure proposed in [1]–[4] for the generation of turbulent velocity fields with prescribed second‐order statistics. The velocity field is represented as the sum of velocities induced by a set of randomly distributed spots. Velocity distribution inside of each spot is found in such a way that the fluctuations possess prescribed statistical properties. The procedure is applied for the generation of LES inlet conditions for the decaying turbulence convecting downstream in a box. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Economical discretization schemes for the finite‐section method
Authors: Lebedeva E.V. , Solodky S.G. 
Published: September 2008

AbstractA problem of economical discretization of equations, arising at the finite‐section approximation of Fredholm integral equations of the first kind on the half‐line, are investigated. The piecewise‐constant discretization schemes providing given accuracy are developed for finite‐section equations. The order estimates for the volume of used discrete information are calculated. The comparative analysis of the information expenses for proposed schemes and known earlier is given. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Null controllability of degenerate parabolic equations
Authors: Martinez Patrick , Cannarsa Piermaco , Vancostenoble Judith 
Published: September 2008

AbstractMotivated by a boundary layer problem, we are interested in the controllability properties of parabolic equations degenerating at the boundary of the space domain.We derive new Carleman estimates for a class of degenerate parabolic equation; the proof is based in particular on Hardytype inequalities. Then we deduce observability and null controllability results. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electromagnetic and thermal modelling of axisymmetric induction furnaces
Authors: Bermúdez A. , Gómez D. , Muñiz M.C. , Salgado P. 
Published: September 2008

AbstractA numerical method to describe the thermo‐electric behavior of an induction heating furnace is introduced. It is obtained by using an enthalpy formulation concerning the thermal model and an integral representation of the electromagnetic potential in an unbounded domain. A BEM‐FEM method is used and an iterative algorithm together with numerical results for an industrial heating system are presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Design of robust signal and clock networks
Authors: Panitz P. , Olbrich M. , Barke E. , Buehler M. , Koehl J. 
Published: September 2008

AbstractAs technology scales down into the nanometer region new design challenges emerge. Wire delays become the performance bottleneck in VLSI circuits. Copper is introduced as new wiring material because of its low sheet resistivity, hence low signal propagation delay. The main defect mechanism shifts from shorts to opens due to the different manufacturing process for copper wires. Open defects limit functional yield. Parametric yield decreases because of timing uncertainties emerging from manufacturing variation. Clock skew variation becomes critical because it may shorten the cycle length of the critical path. The variation of signal nets has to be considered simultaneously avoiding overly pessimistic designs. Design techniques which reduce the variation of design parameters avoid over design and increase parametric yield.Whereas tree topologies have been applied due to their minimal wire length, the application of generic routing graphs provides multiple paths to specific sinks. Multiple paths from source to sink increase the robustness against open defects and smoothes the effect of variation. New design techniques applying loops in VLSI wiring networks are the topic of this abstract. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hybrid neural network shock absorber model
Authors: Pracny Vladislav , Meywerk Martin 
Published: September 2008

AbstractA hybrid neural network model is presented and described. The model is composed of a mechanical and thermodynamical part. The mechanical part is described by Akima spline in combination with a feed‐forward neural network, while in the case of the thermodynamic part differential equation of dissipative heating is formulated. The interface between both part is provided by the neural network. To identify a proper parameter set of the hybrid model a shock absorber of a middle class passenger car is measured on a servo‐hydraulic testing machine. As an excitation a stochastic signal with a predefined power spectral density (PSD) is used. Subsequently the hybrid shock absorber is implemented into a full vehicle model in ADAMS/Car to test its numerical performance and influence on the vertical vehicle dynamics. As reference a standard spline shock absorber model is taken. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A contribution to the modeling of metal foams on the mesoscale
Authors: Schwarzer Daniel , Gatouillat Sebastien , Proppe Carsten 
Published: September 2008

AbstractDue to their useful properties in lightweight construction and due to their excellent behavior in energy absorption for example in crash mechanics, metal foams became an interesting, often utilized and investigated material. For the determination of the mechanical properties of foams without the help of expensive experiments, a way for computing these properties is searched. The problem in doing so is that foams can be composed out of randomly distributed edges and faces with varying thickness and of other inhomogeneities on the mesoscale like imperfections. The goal in this paper is, to investigate the influence of these irregularities on the mechanical, linear elastic properties of a metal foam on the macroscale and to determine the size of a representative volume element, for which the irregularities on the mesoscale do not have a great influence on the linear elastic properties. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analytical determination of residual stresses in a butt‐weld of two thin rectangular plates
Authors: Tokovyy Yuriy V. , Ma Chien‐Ching 
Published: September 2008

AbstractBased upon the direct integration method, the technique for analysis of residual stresses in a thin rectangular plate consisting of two butt‐welded plates is presented. The material of plate is assumed to be elastic‐plastic. The welded joint is modeled by a locally distributed field of longitudinal and transversal residual strains. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)