bluuebunny/crossref_metadata_2025 huggingface dataset:
When words feel right: How affective expressions of listeners change a speaker's language use
Authors: Beukeboom Camiel J.
Published: September 2008

Based on conversation research and work showing that affective cues help to tune information processing to situational demands, it was hypothesized that affective expressions of listeners would influence how speakers represent communicated information in language. Participants were asked to orally communicate an event presented in a film clip to two other participants. These other participants were actually confederates who either adopted a positive or negative nonverbal expression during the story of the participant. Results show that participants talking to smiling listeners used more interpretive, abstract language, whereas participants talking to frowning listeners stayed with the concrete and descriptive facts. These effects of external affective cues on language abstraction were not mediated by the speaker's mood. Implications for interpersonal conversation are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Electroactive Dipyrromethene‐Cu(II) Monolayers Deposited onto Gold Electrodes for Voltammetric Determination of Paracetamol
Authors: Saraswathyamma Beena , Grzybowska Izabela , Orlewska Czesława , Radecki Jerzy , Dehaen Wim , Kumar Krishnapillai Girish , Radecka Hanna
Published: September 2008

Dipyrromethene‐Cu(II) derivatives possessing two dodecane alkyl chains have been used for the modification of gold electrodes. Electroactive host molecules have been incorporated into a lipophilic dodecanethiol SAM deposited onto gold electrodes through hydrophobic and van der Waals interactions (embedment technique). The presence of dipyrromethene‐Cu(II) redox centers on the electrode surface was proved by cyclic voltammetry and Osteryoung square‐wave voltammetry. The Au electrodes incorporating redox active Cu(II)‐dipyrromethene SAMs were used for the direct voltammetric determination of paracetamol in human plasma.
A Graphite‐Polyurethane Composite Electrode for the Analysis of Furosemide
Authors: Semaan Felipe S. , Pinto Edilson M. , Cavalheiro Éder T. G. , Brett Christopher M. A.
Published: September 2008

A graphite‐polyurethane composite electrode has been used for the determination of furosemide, a antihypertensive drug, in pharmaceutical samples by anodic oxidation. Cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the electrooxidation process at +1.0 V vs. SCE over a wide pH range, with the result that no adsorption of analyte or products occurs, unlike at other carbon‐based electrode materials. Quantification was carried out using cyclic voltammetry, differential pulse voltammetry, and square‐wave voltammetry. Linear ranges were determined (up to 21 μmol L−1 with cyclic voltammetry) as well as limits of detection (0.15 μmol L−1 by differential pulse voltammetry). Four different types of commercial samples were successfully analyzed. Recovery tests were performed which agreed with those obtained by spectrophotometric evaluation. The advantages of this electrode material for repetitive analyzes, due to the fact that no electrode surface renewal is needed owing to the lack of adsorption, are highlighted.
A Study of Nafion‐Coated Bismuth‐Film Electrode for the Determination of Zinc, Lead, and Cadmium in Blood Samples
Authors: Liu Benzhi , Lu Liyuan , Wang Min , Zi Yanqin
Published: September 2008

In this article a sensitive differential pulse stripping voltammetry technique on Nafion‐coated bismuth‐film electrode (NCBFE) was studied for the simultaneous determination of zinc, cadmium, and lead ions in blood samples at ultra trace levels. The measurement results were in excellent agreement with those obtained from atomic absorption spectroscopy. Various operational parameters were investigated and discussed in terms of their effect on the measurement signals. Under optimal conditions, calibration curves for the simultaneous determination of zinc, cadmium, and lead ions were achieved, based on three times the standard deviation of the baseline, the limits of detection were 0.09 μg L−1 for Cd(II), 0.13 μg L−1 for Pb(II), and 0.97 μg L−1 for Zn(II) respectively.
The Influence of Electrode Porosity on Diffusional Cyclic Voltammetry
Authors: Menshykau Denis , Compton Richard G.
Published: September 2008

A simple generic model to predict the influence of electrode porosity on the cyclic voltammetric response of an electrode is presented. The conditions under which deviation from the behavior of a perfectly flat, planar electrode can be expected are predicted. The scope for misinterpretation when conventional flat electrode theory is applied to porous electrodes is highlighted, especially in respect to the extraction of electrode kinetic parameters and the influence of ‘electrocatalysis’.
Particulate‐laden‐SO2 scrubbing in a tapered bubble column
Authors: Bandyopadhyay Amitava , Biswas Manindra Nath
Published: September 2008

The performance of a tapered bubble column that generates higher fractional gas hold up with least power consumption than existing systems under similar hydrodynamic conditions is reported in this article for particulate‐laden‐SO2 scrubbing. Firstly, quiescent batch studies were carried out to analyze SO2 removal at various initial particle concentrations. Results revealed that presence of particles improved the SO2 removal efficiency to about 14–27% that was elucidated by the facilitated adsorptive mass transport. The performance of the system was analyzed in subsequent experimentation operating it under continuous mode for particulate‐laden‐SO2 scrubbing using water and dilute NaOH. Results indicated that the removal efficiency of SO2 was improved to about 25%/(W/m3) due to change in the column geometry and to about 16.7%/(W/m3) due to presence of particles (fly‐ash) within the range of variables studied. The enhancement of removal of SO2 due to presence of particulate matter and that due to alkali scrubbing were quantified and compared. Operating regimes of maximum removal efficiencies (∼100%) of SO2 and particulates either alone or in combination were determined from experimental results. Empirical and semi‐empirical correlations were developed for predicting the scrubbing performances of the tapered column in water and dilute NaOH, respectively. Experimental values fitted excellently well with the predicted values. The superiority of the tapered bubble column over a conventional bubble column for scrubbing of particulates and SO2 either alone or in combination was described. © 2008 American Institute of Chemical Engineers Environ Prog, 2009
A comparison of three methods to determine mobile station location in cellular communication systems
Authors: Simić Mirjana I. , Pejović Predrag V.
Published: September 2008

Three methods to determine location of a mobile station in cellular communication systems are proposed and compared in this paper. The methods are introduced taking global system for mobile communications (GSM) networks as an example, although the results could be generalised for application in universal mobile telecommunications system (UMTS) networks. All three of the methods determine the mobile station location using coordinates of several base stations and corresponding timing advance (TA) parameter values. The values of the TA parameter are obtained applying the forced handover technique. The first method, the method of squares, locates the mobile station in a square region according to the data provided by one base station. The data are collected for several base stations and assembled such the mobile station is located in an intersection of the square regions, which takes a rectangular shape. This rectangle may be refined by the other two methods. The method of annuli locates the mobile station in an annular region, according to the definition of the TA parameter, while the method of circles locates the mobile station within a circular region. The region of the mobile station location is obtained as an intersection of the regions, again. In this manner, the area where the mobile station might be located is reduced. The mobile station coordinates are estimated applying a probabilistic approach, treating the mobile station coordinates as a two‐dimensional random variable. It is shown that the methods of squares and circles are robust, not being affected by indirect wave propagation, while the method of annuli provides the best localisation, but it is sensitive on indirect wave propagation. The methods are verified applying simulation of a real GSM network. Copyright © 2008 John Wiley & Sons, Ltd.
Inhibition of hyaluronan export attenuates cell migration and metastasis of human melanoma
Authors: Monz Katharina , Maas‐Kück Kathrin , Schumacher Udo , Schulz Tobias , Hallmann Rupert , Schnäker Eva Maria , Schneider Stefan W. , Prehm Peter
Published: September 2008

When secreted from malignant cells, hyaluronan facilitates tumor invasion and metastasis, as inhibition of its export by zaprinast inhibited metastasis formation in mice. However, the precise steps of the metastatic cascade, which were influenced by zaprinast, have not been identified as yet. Here we analyzed the cell biological effects of the inhibitor on three human melanoma cell lines that differed in their hyaluronan production and their metastatic capability when xenografted into SCID mice. We measured the influence of zaprinast on cellular hyaluronan export, surface coat formation, proliferation, random migration, colony formation in soft agar, adhesion, and transepithelial resistance. Concentrations of zaprinast not affecting cell proliferation, adhesion and transepithelial resistance, nevertheless reduced hyaluronan export by 50%, surface coat formation, random migration, and colony formation in soft agar. These results indicate that hyaluronan enhances metastasis formation primarily in those steps of the metastatic cascade, which involves tumor cell migration. J. Cell. Biochem. 105: 1260–1266, 2008. © 2008 Wiley‐Liss, Inc.
A novel fair random access scheme with throughput optimization using fuzzy controller for wireless systems
Authors: Rizk M. R. M. , Dessouky M. I. , El‐Dolil Sami A. , Abd‐Elnaby Mohammed
Published: September 2008

Good backoff algorithms should be able to achieve high channel throughput while maintaining fairness among active nodes. In this paper, we propose a novel backoff algorithm to improve the fairness of random access channels, while maximizing channel throughput. The mechanism of the proposed backoff algorithm uses backoff delay (retransmission delay) and channel‐offered traffic to dynamically control the backoff interval, so that each active node increases its backoff interval in the case of collision by a factor which exponentially decreases as the backoff delay increases, and decreases its backoff interval in the case of successful transmission by a factor which exponentially decreases as the backoff delay of previous retransmission attempts increases. Also, the backoff interval is controlled according to the channel offered, traffic using a fuzzy controller to maximize channel throughput. Furthermore, the operation of the proposed backoff algorithm does not depend on knowledge of the number of active nodes. A computer simulation is developed using MATLAB to evaluate the performance of the proposed backoff algorithm and compare it with the binary exponential backoff (BEB) scheme, which is widely used owing to its high channel throughput, while its fairness is relatively poor. It is shown that the proposed backoff algorithm significantly outperforms the BEB scheme in terms of improving the performance of fairness, and converges to the ideal performance as the minimum backoff interval increases, while achieving high channel throughput. Copyright © 2008 John Wiley & Sons, Ltd.
Building and solving matrix spectral problems
Authors: Ahues Mario , Largillier Alain
Published: September 2008

When an infinite dimensional operator T: X → X is approximated with (a slight perturbation of) an operator Tn : X → X of finite rank less than or equal to n, the spectral elements of an auxiliary matrix Z ∈ ℂn ×n , lead to those of Tn, if they are computed exactly. This contribution covers a general theoretical framework for matrix problems issued from finite rank discretizations and perturbed variants, the stop criterion of the QR method for eigenvalues, the possibility of using the Newton method to compute a Schur form, and the use of Newton method to refine coarse approximate bases of spectral subspaces. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Orientable and non‐orientable director fields for liquid crystals
Authors: Ball John M. , Zarnescu Arghir
Published: September 2008

Uniaxial nematic liquid crystals are often modelled using the Oseen‐Frank theory, in which the mean orientation of the rodlike molecules is described through a unit vector field n. This theory has the apparent drawback that it does not respect the head‐to‐tail symmetry in which n should be equivalent to −n; that is, instead of n taking values in the unit sphere 𝕊2, it should take values in the sphere with opposite points identified, i.e. in the real projective plane ℝP2. The Landau‐de Gennes theory respects this symmetry by working with the tensor Q = s (n ⊗ n − ⅓Id). In the case of a non‐zero constant scalar order parameter s the Landau‐de Gennes theory is equivalent to that of Oseen‐Frank when the director field is orientable.

We report on a general study of when the director fields can be oriented, described in terms of the topology of the domain filled by the liquid crystal, the boundary data and the Sobolev space to which Q belongs. We also analyze the circumstances in which the non‐orientable configurations are energetically favoured over the orientable ones. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical schemes for kinematic flows with discontinuous flux
Authors: Bürger Raimund , García Antonio , Karlsen Kenneth H. , Towers John D.
Published: September 2008

Spatially one‐dimensional kinematic flows arise in a series of applications including traffic flow and sedimentation. They lead to nonlinear systems of conservation law whose flux has an explicit “concentration times velocity” structure. A new family of simple numerical schemes which are adapted to this structure, and which handle fluxes that are discontinuous with respect to the space variable, is presented and in part analyzed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gradient systems and gradient‐like systems
Authors: Chill Ralph
Published: September 2008

We briefly discuss existing results on convergence and nonconvergence to equilibrium of bounded solutions of gradient systems and gradient‐like systems. We especially raise the question of the influence of the ambient metric. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Guaranteed affine lower bound functions for multivariate polynomials
Authors: Garloff Jürgen , Smith Andrew P.
Published: September 2008

The construction of affine lower bound functions for multivariate polynomials based on Bernstein polynomials is presented. These bound functions are guaranteed also in the presence of rounding errors and (interval) data uncertainties. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Method of multiple scales with three time scales
Authors: Kramer Peter , Khan Adnan , Stathos Philip , Lee DeVille R. E.
Published: September 2008

Some confusion appears in the literature regarding the extension of the method of multiple scales to three or more time scales. While the work of Murdock and Wang [1] correctly indicates some obstructions to such an extension in some types of problems, other work suggests that the extension should almost never be possible [2]. These pessimistic results generally follow from the imposition of additional restrictions in the calculation, which really are not necessary [3]. We will show on some simple ODE models how a systematic implementation of the method of multiple scales can succeed in correctly capturing three active time scales, though more calculation is required than one might expect from naive considerations. On the other hand, an extension of the method of averaging to three time scales produces an incorrect approximation in these problems [4]. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New theory of spatio‐temporal chaos in nonlinear systems of partial differential equations
Authors: A.Magnitskii Nikolai
Published: September 2008

It is shown that there exists one universal scenario of transition to chaos in three considered systems of nonlinear partial differential equations of diffusion type. It is the subharmonic cascade of bifurcations of two‐dimensional tori along one or both frequencies. So, it is shown that the new universal Feigenbaum‐Sharkovskii‐Magnitskii theory of dynamical chaos in nonlinear differential equations is applicable also for nonlinear partial differential equations of diffusion type. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Location of the shoulder joint centre and identification of the body segment parameters
Authors: Monnet Tony , Atchonouglo Kossi , Vallée Claude
Published: September 2008

This paper presents two methods for human body modelisation: the location of the joint centre and the identification of the body segment inertial parameters. These methods require only tools usually used in biomechanics (force plate and motion analysis system) and allow to have precise and personal parameters. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On some nonlinear elliptic problems with an unknown measure data
Authors: Padial J.F.
Published: September 2008

We prove the existence of a solution of some nonlinear elliptic problems with a Radon measure data. In contrast with the usual elliptic problem, this measure will be an unknown of the problem depending on the solution. We shall use a Minimax Ambrosetti–Rabinowitz argument. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling and measurand identification for theMise en Pratiqueof the kelvin
Authors: Pavese F. , Ichim D.
Published: September 2008

A big variety of modelling requirements corresponds to the variety of definitions allowed by the ‘mise en pratique’ of the kelvin. They range from thermodynamic ones, requiring a correct physical modelling, to semi‐empirical, to empirical ones. Since temperature can be measured only by measuring another physical quantity, e.g., electrical resistance, pressure, a change in length, etc., the measurand related to each of the above definition must be correctly and clearly identified, which can be less obvious than it might look. The paper is introducing the general thermometric problem, limited to making the subsequent illustration of the problems concerning measurand identification and modelling issues understandable. Then it summarises, mainly referring to the literature, the procedures to correctly and clearly identify the measurand of each given definition, with examples of possible ambiguities, and illustrates the characteristics of the main families of models suitable for use in temperature scales, used or candidates for use as ‘mises en pratique’ of the kelvin, from the viewpoint of the metrologist, concerning either the mathematical requirements and the requirements of the statistical treatment of the experimental temperature data. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical simulation of wind turbine rotors aerodynamics
Authors: Redchyts' Dmytro O.
Published: September 2008

The report covers the typical aspects of numerical simulation of aerodynamics and dynamics of wind turbines rotors such as selection of initial mathematical model and model of turbulence, selection of the numerical method, verification and testing of developed CFD codes, post‐processing and visualization of obtained results. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Recent additions to SLEPc, the Scalable Library for Eigenvalue Problem computations
Authors: Roman Jose E.
Published: September 2008

SLEPc is a software library for the solution of large, sparse eigenvalue problems on parallel computers. We have recently extended its functionality by incorporating a Krylov‐Schur eigensolver and a module for singular value computation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A new approach to analysis of free beam vibrations
Authors: Saurin V. , Kostin G.
Published: September 2008

Based on the linear theory of elasticity and the method of integrodifferential relations a countable system of ordinary differential equations is derived to describe longitudinal and lateral free vibrations of rectilinear beams. In the approach under consideration the stress‐strain relation is specified by an integral equality instead of the local Hooke's law. After expansion of unknown stress and displacement functions in polynomial series with respect to transversal Cartesian coordinates and system decomposition due to domain symmetry the consistent boundary value problems are solved. The influence of geometrical and elastic characteristics of rectilinear beams on eigenfrequencies is investigated. The various kinds of longitudinal and lateral free motions are found out in the models under study. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Jacobi–Davidson like method for nonlinear eigenvalue problems based on singularity theory
Authors: Schreiber Kathrin , Schwetlick Hubert
Published: September 2008

We present a Jacobi–Davidson like correction formula for left and right eigenvector approximations for non‐Hermitian nonlinear eigenvalue problems. It exploits techniques from singularity theory for characterizing singular points of nonlinear equations. Unlike standard nonlinear Jacobi‐Davidson, the correction formula does not contain derivative information and works with orthogonal projectors only. Moreover, the basic method is modified in that the new eigenvalue approximation is taken as a nonlinear Rayleigh functional obtained as root of a certain scalar nonlinear equation the existence of which – as well as a first order perturbation expansion – is shown. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tensegrities
Authors: Servatius Brigitte
Published: September 2008

Tensegrities, or tensed frameworks, are objects that fit well in the domain of metric geometry and combinatorics. Questions of rigidity and stability were already asked by architectural designers like Fuller and Emmerich and also by the artist Snelson in the 1960s and 1970s. Key results and conjectures of that time are compiled in Branko Grünbaum's Lectures in lost mathematics. Recent mathematical progress has paved the way to new applications in the biological sciences as well as in structural engineering. The talks in this minisymposium, whose content is summarized here, intended to communicate this progress to researchers in the fields of mathematics, computer science, biology, and mechanical engineering. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Homogeneous groups and multiscale intensity models for multiname credit derivatives
Authors: Papageorgiou Evan , Sircar Ronnie
Published: September 2008

We discuss a computationally tractable approach to the valuation of multiname credit derivatives employing name grouping for dimension reduction, and singular perturbation approximations for model robustness. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On an application of the QMR_SYM method to complex symmetric shifted linear systems
Authors: Sogabe T. , Hoshi T. , Zhang S.‐L. , Fujiwara T.
Published: September 2008

We consider the solution of complex symmetric shifted linear systems. Such systems arise in large scale electronic structure theory and there is a strong need for the fast solution of the systems. In this paper, we describe an algorithm for solving the systems, which is based on the QMR_SYM method for solving complex symmetric linear systems. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydrodynamic stability control in CFD by shape optimization
Authors: Heuveline Vincent , Strauß Frank
Published: September 2008

We propose a numerical scheme which aims at solving shape optimization problems in the context of hydrodynamic stability. It is the goal to minimize the drag and ensure hydrodynamic stability by modification of parts of the underlying geometry. The stability issues are represented by eigenvalue constraints. Numerical results for a test case show that a transition from an unstable design into a stable one is attainable by considering an adequate change of the geometry. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Global attractivity conditions for a single species model
Authors: Tkachenko Viktor , Trofimchuk Sergei
Published: September 2008

We give sharp conditions for global attractivity of the zero solution of the nonlinear difference equation which arises in many contexts in mathematical biology xn +1 = qxn + fn (xn , …, xn –k ), n ∈ ℤ, where q ∈ (0,1] and functions fn satisfy the generalized Yorke conditions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A parallel Krylov‐Schur implementation for large Hermitian and non‐Hermitian eigenproblems
Authors: Hernández V. , Roman J. E. , Tomás A.
Published: September 2008

This work presents a new implementation of a Krylov‐Schur eigensolver in SLEPc (Scalable Library for Eigenvalue Problem Computations), a software library for the solution of large, sparse eigenvalue problems on parallel computers. Some parallel performance results are given, showing better scalability compared to ARPACK. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical techniques for ice masses dyamics simulation by using a complete shallow ice approximation
Authors: Calvo N. , Durany J. , Toja R. , Vázquez C.
Published: September 2008

In this work a complex coupled shallow ice model which governs the thermal, hydrodynamic and mechanical processes in the dynamics of large ice masses is proposed and solved by means of efficient numerical techniques. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Robust expansion of subspaces in iterative projection methods for large eigenvalue problems
Authors: Voss Heinrich
Published: September 2008

The Jacobi–Davidson method is known to converge at least quadratically if the correction equation is solved exactly, and it is common experience that the fast convergence is maintained if the correction equation is solved only approximately. Here we derive the Jacobi–Davidson method in a way that explains this robust behavior. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical simulation of nonlinear electro‐elastostatics
Authors: Vu D. K. , Steinmann P. , Possart G.
Published: September 2008

The numerical simulation of nonlinear electro‐elastostatics is addressed in this work. Based on the governing equations of the electric field and the governing equations of non‐linear elastostatics, a variational formulation is formulated and the finite element method is employed to solve the non‐linear electro‐mechanical coupling problem. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamic transitions in classical and geophysical fluid dynamics
Authors: Ma Tian , Wang Shouhong
Published: September 2008

We present a newly developed dynamic transition theory developed recently by the authors and its applications to classical and geophysical fluid dynamics. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical solution of Volterra integro‐differential equations modelling thalamo‐cortical systems
Authors: Zubik‐Kowal B. , Jackiewicz Z. , Hoppensteadt F.C.
Published: September 2008

Our study concerns thalamo‐cortical systems which are modelled by nonlinear systems of Volterra integro‐differential equations of convolution type. The thalamo‐cortical systems describe a new architecture for a neurocomputer. Such a computer employs principles of human brain. It consists of oscillators which have different frequencies and are weakly connected via a common medium forced by an external input.

Since a neurocomputer consists of many interconnected oscillators (referred also as neurons), the thalamo‐cortical systems include large numbers of Volterra integro‐differential equations. Solving such systems numerically is expensive not only because of their large dimensions but also because of many kernel evaluations which are needed over the whole interval from the initial point, where the initial condition is imposed, up to the present point, where the computations are currently executed. Moreover, the whole computed history of the solution has to be stored in the memory of the computing machine. Therefore, robust and efficient numerical algorithms are needed for computer simulations for the solutions to the thalamocortical systems.

In this paper, we illustrate an iteration technique to solve the thalamo‐cortical systems. The proposed successive iterates are vector functions of time, which change the original problems into systems of easier and separated equations. Such separated equations can then be solved in parallel computing environments. Results of numerical experiments are presented for large numbers of oscillators. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Myeloablative chemotherapy with autologous bone marrow rescue in children and adolescents with recurrent malignant astrocytoma: Outcome compared with conventional chemotherapy: A report from the Children's Oncology Group
Authors: Finlay Jonathan L. , Dhall Girish , Boyett James M. , Dunkel Ira J. , Gardner Sharon L. , Goldman Stewart , Yates Allan J. , Rosenblum Marc K. , Stanley Philip , Zimmerman Robert A. , Wallace Dana , Pollack Ian F. , Packer Roger J. ,   for the Children's Cancer Group
Published: September 2008

Purpose

Children and adolescents with malignant astrocytomas recurring after initial treatment have a dismal prognosis, with only rare patients surviving 1‐year beyond recurrence. The purpose of this study was to attempt to improve their survival.

Methods

Twenty‐seven children and adolescents with malignant astrocytomas [17 glioblastoma multiforme and 10 anaplastic astrocytoma (AA)] following initial tumor progression, received myeloablative chemotherapy followed by autologous marrow rescue with one of three thiotepa and etoposide‐based chemotherapy regimens, administered alone (n = 11) or combined with carmustine (n = 5) or carboplatin (n = 11). Time to progression and death following myeloablative chemotherapy for these patients was compared non‐randomly with outcome of a contemporaneously treated cohort of similar patients who received only conventional chemotherapy following initial tumor progression. The two cohorts were compared for age, histology, prior therapies, extent of surgical resection at progression, and time from initial diagnosis to progression.

Results

Five of 27 children (two with glioblastoma multiforme and three with AA) survive event‐free from 8.3 to 13.3 years (median of 11.1 years) following myeloablative chemotherapy. Of 56 children with recurrent malignant astrocytoma who received conventional chemotherapy following initial progression, no patient survives. Differences in distributions of survival were not significant when stratified by surgical debulking (P = 0.39). However, for patients who were surgically debulked, the survival distributions are significantly different (P = 0.017).

Conclusions

Myeloablative chemotherapy with autologous marrow rescue can produce durable remissions in children and young adults with recurrent malignant gliomas, in the setting of minimal residual tumor burden achieved surgically. Pediatr Blood Cancer 2008;51:806–811. © 2008 Wiley‐Liss, Inc.
Outcome and toxicity of chemotherapy for acute lymphoblastic leukemia in children with down syndrome
Authors: Shah Niketa , Al‐Ahmari Ali , Al‐Yamani Arwa , Dupuis Lee , Stephens Derek , Hitzler Johann
Published: September 2008

Background

Acute lymphoblastic leukemia (ALL) in children with Down syndrome (DS) presents with an increased incidence, higher frequency of adverse effects and inferior probability of survival. Attempts at improving outcomes face the dilemma posed by the need to avoid excessive toxicity while maintaining the efficacy of treatment. Dose reductions and avoidance of infusions of intermediate and high‐dose methotrexate are common in this group.

Procedure

In a matched pair analysis we compared adverse effects and survival after ALL chemotherapy using intermediate and high doses of methotrexate in children with and without Down syndrome.

Results

Following intermediate and high doses of methotrexate to treat primary ALL, children with DS did not require opiate analgesia and parenteral nutrition for severe mucositis more often than children without DS. Children with DS spent more days in hospital and missed more doses of maintenance chemotherapy. Chemotherapy dose reductions were common and in this study had no detectable adverse impact. Event‐free and overall survival (OS) of children with ALL was lower in the DS than the non‐Down syndrome (NDS) control group. The difference, however, was no longer significant during the recent treatment era.

Conclusions

The feasibility of all treatment elements that are efficacious in pediatric ALL needs to be carefully considered in children with DS. In addition to survival data, the prospective collection of data on both adverse events and treatment modifications is essential to strike a balance between the avoidance of adverse effects and the need for intensive therapy that will safely improve ALL outcomes in this group. Pediatr Blood Cancer 2009;52:14–19. © 2008 Wiley‐Liss, Inc.
Defect characterization and analysis of III‐V nanowires grown by Ni‐promoted MBE
Authors: Lari L. , Murray R. T. , Gass M. H. , Bullough T. J. , Chalker P. R. , Kioseoglou J. , Dimitrakopulos G. P. , Kehagias Th. , Komninou Ph. , Karakostas Th. , Chèze C. , Geelhaar L. , Riechert H.
Published: September 2008

We report on transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) analysis of GaN and Al0.2Ga0.8N nanowires (NWs) grown by radio frequency plasma assisted Molecular Beam Epitaxy (PAMBE) on c‐sapphire substrates. Conventional TEM images of single nanowires removed from the substrate exhibit a high density of basal stacking faults. Further analyses were performed using the aberration‐corrected SuperSTEM facility. Geometric phase analysis (GPA) was applied to this data revealing the characteristic lattice displacement introduced by intrinsic basal stacking faults. The nickel‐based “seeds”, which were employed to promote the NW‐type growth, are found to be situated at the tip of each nanowire. Different types of analyses were applied to lattice images of these seeds including GPA, projection method analysis and Fast Fourier transform of the HREM images. All three approaches yielded lattice constants and displacements with good agreement. The measured lattice values in the GaN nanowire body were in good agreement with the lattice constants of relaxed bulk GaN. For the seed particles the resulting lattice spacing was attributable, within the experimental error, to either nickel oxide, Ni3Ga, or an intermediate alloy phase. The defect density was measured in the AlGaN nanowires and was found to be in the order of 106 cm–1. The results are critically discussed in relation to the possible growth mechanisms of the NWs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strain relaxation in AlN/GaN heterostructures grown by molecular beam epitaxy
Authors: Dimitrakopulos G. P. , Komninou Ph. , Kehagias Th. , Sahonta S.‐L. , Kioseoglou J. , Vouroutzis N. , Hausler I. , Neumann W. , Iliopoulos E. , Georgakilas A. , Karakostas Th.
Published: September 2008

The strain distribution and defects in a graded AlN/GaN heterostructure comprising AlN layers from 3 nm up to 100 nm grown by plasma‐assisted MBE were studied using transmission electron microscopy techniques. Gradual strain relaxation was observed as well as strain partitioning between the GaN spacers and the thicker AlN layers. Elastic strain is retained even in the thicker layers of the heterostructure. Extensive introduction of threading and misfit dislocations is observed at and above the 7 nm AlN layer. The threading dislocations adopt inclined zig‐zag line directions thus contributing to the relief of alternating compressive‐tensile elastic strain across the the layers of the heterostructure. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of composition on the bonding environment of In in InAlN and InGaN epilayers
Authors: Katsikini M. , Pinakidou F. , Paloura E. C. , Komninou Ph. , Iliopoulos E. , Adikimenakis A. , Georgakilas A. , Welter E.
Published: September 2008

We report on the bonding environment of In in InxAl1–xN (0.07 < x < 0.25) and InyGa1–yN (0.7 < y < 1) epilayers using extended X‐ray absorption fine structure (EXAFS) spectroscopy. The EXAFS analysis reveals that the In–N distance, in both the InAlN and the InGaN ternaries, is only weakly dependent on the In content. Contrary to that, the In–cation distances (in the 2nd nearest neighbour shell) have values closer to those predicted by Vegard's law. More specifically, the distribution of the In–cation distances is bimodal with the ff In–Ga and In–Al distances being smaller than the In–In distance. The variation of the In–Ga and In–Al distances with the In content is in agreement with Vegard's law while the In–In distance deviates from the expected values for In fractions smaller than 0.7. The identified composition‐dependent variation of the In–N and In–cation distances, indicates that the alloying induced stress in InAlN and InGaN is mainly accommodated by bond angle variation rather than bond length deformation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coincidence detection and spike regeneration in artificial neurons
Authors: Samardak A. S. , Taylor S. , Nogaret A. , Hollier G. , Austin J. , Farrer I. , Ritchie D. A.
Published: September 2008

We report on a monolithic semiconductor device that computes the coincidence of time delayed electrical impulses and selectively regenerates those impulses that meet within 10 μs of each other. We obtain pulse regeneration using the negative feedback of a tunnel device and demonstrate reliable pulse amplification using an external circuit. The device emulates biological neurons which detect correlations between spike trains in real time and are able to modify synaptic weights through spike timing dependent plasticity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Micropore modification in InP
Authors: Nohavica D. , Gladkov P. , Jarchovský Z. , Zelinka J. , Komninou Ph. , Delimitis A. , Kehagias Th. , Karakostas Th.
Published: September 2008

The structural features and optical properties of microporous InP substrates used for epitaxial overgrowth of thin films have been investigated. Both crystalographically oriented (CO) and current line oriented (CLO) pore networks were created by electrochemical dissolution. Heat treatment of the InP pores converted them into microcavities maintaining the same crystallographic direction. The effect of phosphorus vapour pressure was proved to be crucial for the microcavity formation, since it influences the mass transport during heat treatment. Electron microscopy and photoluminescence experiments revealed the absence of significant extended defects, both after the pore and cavities formation. The capability of improved structural quality homo‐ and hetero‐epitaxial overgrown films on the porous InP, was also demonstrated. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear optical properties of Au nanoclusters encapsulated into hybrid block copolymer micelles
Authors: Iliopoulos K. , Athanasiou D. , Meristoudi A. , Vainos N. , Pispas S. , Couris S.
Published: September 2008

In this work, the nonlinear optical (NLO) response of suspensions of Au nanoclusters encapsulated into hybrid block copolymer micelles was investigated by using the Z‐scan technique, employing 35 ps, 532 nm laser pulses. The block copolymer used for the encapsulation of the Au nanoclusters was poly (isoprene‐b‐acrylic acid) (PI‐PAA). The real and imaginary parts of the third‐order nonlinear susceptibility χ(3) of the dispersions were determined and were both found to be of the order of 10–13 esu for Au concentration ranged between 1 to 20 mM and of positive sign. All dispersions were exhibiting strong optical limiting action. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Auger recombination in silicon nanocrystals embedded in SiO2 wide band‐gap lattice
Authors: Mahdouani M. , Bourguiga R. , Jaziri S. , Gardelis S. , Nassiopoulou A. G.
Published: September 2008

We calculate the ground and excited electron and hole levels in spherical Si nanocrystals (quantum dots) embedded within SiO2 in a multiband effective mass approximation. The obtained energies of electron and hole are used to estimate the Auger Recombination (AR) lifetime in Si Nanocrystals (NCs). The excited electron, excited hole and biexciton AR types are considered. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Substituent effect on NH bond dissociation enthalpies of amines and amides: A theoretical study
Authors: Kaur Damanjit , Kaur Rupinder Preet , Kohli Ruchi
Published: September 2008

NH bond dissociation enthalpies for the substituted ammonia, amine, amides, and their thio‐ and seleno‐analogs have been studied employing ab initio and density functional methods. The orbital interactions involving lone pair of electrons on nitrogen and substituent, electrostatic interactions, spin delocalization, and hydrogen bonding are the important factors affecting the stability of the molecule and the radical. The molecule stabilization effect and radical stabilization effect have been calculated using isodesmic reactions in order to analyze the effect of substituent on the stabilization of the molecule and the radical. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Ground and low‐lying excited C2v states of FeO2—A challenge to computational methods
Authors: Grein Friedrich
Published: September 2008

DFT (BPW91 and B3PW91), CCSD, CCSD(T), and MP2 geometry optimizations were performed on the lowest A1, A2, B1, and B2 singlet to septet states (a total of 16 states) of FeO2, using in most cases the 6‐311+G(3df) basis set. With few exceptions, the different methods led to similar geometries. The lowest state is 3B1 or 5B2, depending on the method used. The quality of the various computational methods was tested by a comparison of vertical excitation energies with corresponding high‐level MRCI values. The best agreement with MRCI was found for BPW91 and B3PW91, with average deviations of about 0.2 eV. MRCI calculations were carried to extremely low configuration selection thresholds (0.025 μh) in order to find the lowest state of FeO2. The full CI estimate (including Davidson correction and energy extrapolation to 0 μh) gave 3A1 as the lowest state, followed by 5B2 (0.03 eV) and 3B1 (0.06 eV). Both 3B1 and 3A1 have geometries and vibrational frequencies consistent with the observed IR spectrum. The calculated adiabatic electron affinity of FeO2 (from 3B1 of FeO2 to 4B2 of FeO) is 2.46 eV with CCSD(T), and 2.22 eV with BPW91, compared with the experimental value of 2.36 eV. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Position‐dependent disturbance rejection using spatial‐based adaptive feedback linearization repetitive control
Authors: Chen Cheng‐Lun , Yang Yen‐Hsiu
Published: September 2008

In this paper, we propose a new design of spatial‐based repetitive control for a class of rotary motion systems operating at variable speeds. The open‐loop system in spatial domain is obtained by reformulating a nonlinear time‐invariant system with respect to angular displacement. A two‐degree‐of‐freedom control structure (comprising two control modules) is then proposed to robustly stabilize the open‐loop system and improve the tracking performance. The first control module applies adaptive feedback linearization with projected parametric update and concentrates on robust stabilization of the closed‐loop system. The second control module introduces a spatial‐based repetitive controller cascaded with a loop‐shaping filter, which not only further reduces the tracking error, but also improves parametric adaptation. The overall control system is robust to model uncertainties of the system and capable of rejecting position‐dependent disturbances under varying process speeds. Stability proof for the overall system is given. A design example with simulation is provided to demonstrate the applicability of the proposed design. Copyright © 2008 John Wiley & Sons, Ltd.
Childhood traumatic experiences, dissociation and thought suppression in patients with ‘Psychosomatic’ skin diseases
Authors: Besiroglu Lutfullah , Akdeniz Necmettin , Agargun Mehmet Yucel , Calka Omer , Ozdemir Osman , Bilgili Serap Guneş
Published: September 2008

In this study, patients with what were considered ‘psychosomatic’ skin diseases were compared with patients with skin conditions that are thought to be ‘non‐psychosomatic’ diseases in terms of their reported history of childhood traumatic experiences, dissociative experiences and thought suppression. Ninety‐six patients with ‘psychosomatic’ skin disease were included in the study. The comparison subjects (n = 54) were patients with skin conditions believed to have a negligible psychosomatic component and the subjects without skin disease (n = 77). Subjects were administered with the Childhood Trauma Questionnaire (CTQ), the Dissociative Experiences Scale (DES) and the White Bear Suppression Inventory (WBSI). While the ‘emotional neglect’ scores of the psychosomatic' group were significantly higher than that of both ‘non‐psychosomatic’ and healthy subjects, there were no significant differences for the other subscales of the CTQ. The ‘psychosomatic’ group scored significantly higher on the DES absorption scale, DES total and WBSI scores than the other groups. Significantly more patients in the ‘psychosomatic’ group reported a stressful life event as related to the onset of skin complaints compared with the ‘non‐psychosomatic’ group. Our results suggest that the effect of subjective perception of emotional neglect, mediated by stressful life events, increases the vulnerability to psychosomatic disease. Copyright © 2008 John Wiley & Sons, Ltd.
A 34‐year‐old woman with urinary frequency and suprapubic pain
Authors: Crump Ann A. , Gall Zara , Pearce Ian
Published: September 2008

In this problem‐orientated exercise, a case history is presented, followed by a number of relevant questions. The answers will elicit enough information to lead to the next question. Copyright © 2008 Wiley Interface Ltd
Hybrid network based on optical intersatellite communication links and WDM technology
Authors: Carrozzo V. , Parca G.
Published: September 2008

The use of optical wavelengths for intersatellite link can lead the whole system at high data rates performing, low interference, low power requirement and small antenna size. Systems based on Wavelength Division Multiplexing (WDM) technology preserve data signal from interchannel interference. Proposed system is composed of one fixed node, a HAP, High Altitude Platform, in a quasi‐stationary position at an altitude of 30 km from the Earth surface, and a mobile node on a LEO orbit which communicates by an optical link with HAP and other LEO microsatellites. The choice of microsatellites number guarantees a good area target coverage and a continuous data transfer from slave nodes to master, with the consequent increase in communication capacity. The HAP motion makes it possible to configure an ad‐hoc network for the monitoring of natural and man‐made disasters, or every emergency application on rural environment. The main constraint affecting the system performance is concerned with signal degradation, due to antenna misalignment as well as the Doppler effect suffered by the signal because of relative motion between satellite. The subsystem configuration is based on semiconductor laser, transmitting at ITU grid frequencies, and an EDFA preamplifier at receiver end. Copyright © 2008 John Wiley & Sons, Ltd.