bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic positioning of a floating structure
Authors: Pick Marc‐André , Kreuzer Edwin , Wagner Jörg
Published: October 2008

In order to test numerical models describing the dynamics of a wave excited vessel a laboratory model setup for investigating roll motions at zero or small forward speeds was designed. A position and attitude measurement system consisting of an inertial measurement unit and a stereo–camera using an extended Kalman–filter was developed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Steady flow in the Willis circle using a Quemada model
Authors: Postelnicu Adrian , Florea Olivia , Pecurariu Cristian Falup
Published: October 2008

The paper presents new results on the dynamics of blood flow in the Willis circle, by taking into account the non‐Newtonian nature of the blood through a Quemada model. In previous papers we performed a steady analysis of the blood flow in the Willis polygon, by considering the blood as a Newtonian fluid. In hemodynamics this is the first step, while taking into account the non‐Newtonian behaviour of the fluid is called a second order approach. This is in fact the aim of our paper, to compare the results (blood flow rates and pressures) obtained in a non‐Newtonian approach with those furnished by a Newtonian modeling of the blood. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simultaneous reconstruction and segmentation for tomography data
Authors: Ramlau Ronny , Klann Esther , Ring Wolfgang
Published: October 2008

We present a Mumford‐Shah like approach for the inversion of CT and SPECT‐data (Single Photon Emission Computerized Tomography). With this approach we aim at the simultaneous reconstruction and segmentation of activity and density distribution from given tomography data. We assume the functions to be piecewise constant with respect to a set of contours. Shape sensitivity analysis is used to find a descent direction for the cost functional which leads to an update formula for the contour in a level set framework. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computational models for the numerical simulation of voltage operated channels in nano–bio–electronics
Authors: Longaretti Massimo , Jerome Joseph W. , Sacco Riccardo , Chini Bice
Published: October 2008

In this article, we discuss the use of computational models in the study of voltage operated channels (VOCs) for bio‐electronic applications. Electrochemical and fluid–mechanical ionic transport are described through the coupled use of systems of partial and ordinary differential equations (PDEs and ODEs). Functional iteration techniques for system decoupling and mixed–hybridized finite element discretization methods are proposed and validated in the simulation of realistic problems in Electrophysiology and Biochemistry. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cooperative work in an e‐learning environments: the COMSON case
Authors: Bilotta Eleonora , Pantano Pietro , Talarico Valerio
Published: October 2008

Coupled Multiscale Simulation and Optimization in Nanoelectronics project isaMarie Curie RTN supported by the European Commission within the 6th Framework Research Programme of the EU. The COMSON project is run by a Consortium whose multiple aims are: to build an experimental software Demonstrator Platform (DP) for coupled simulation of devices, interconnects, circuits, EM fields and thermal effects (one single framework for simulation tool, optimisation in compound design space); to provide an e‐learning platform to be used as an inter and extra consortium transfer of knowledge (ToK) infrastructure; to provide a collaborative virtual work environment (CWE) to be used both for industrial activities and training. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Turbulent boundary layer on a plate with transpiration: Dynamical and thermal problems
Authors: Vigdorovich Igor
Published: October 2008

Scaling laws are established for the profiles of mean velocity and temperature, Reynolds‐stress components, turbulent heat flux and mean‐square temperature fluctuation, skin friction and wall heat transfer in the turbulent boundary layer on a flat plate with transpiration. In the case of blowing, the velocity and temperature distributions represented in scaling variables outside the viscous sublayer have universal forms known from experimental data for flow over an impermeable flat plate. The turbulent shearing stress and heat flux also can be represented in terms of these two functions. In the case of suction, the mean quantities are described by one‐parameter families of curves. Universal skin‐friction and heat‐transfer laws provide a basis for representation of the skin‐friction and heat‐flux distributions corresponding to different Reynolds numbers and transpiration velocities in terms of universal functions of one variable. The results are obtained without invoking any special closure hypotheses. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron energy level calculations for semiconductor nanostructures
Authors: Betcke Marta M. , Voss Heinrich
Published: October 2008

Although self‐assembled quantum dots are grown on wetting layers, most simulations exclude the wetting layer. The neglected effects on the electronic structure of a pyramidal InAs quantum dot embedded in a GaAs matrix are investigated based on the effective one electronic band Hamiltonian, the energy and position dependent electron effective mass approximation, and a finite height hard‐wall 3D confinement potential. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Newtons coefficient of restitution at the macro‐ and nano‐scales
Authors: Weir Graham J.
Published: October 2008

Newtons Coefficient of Restitution, for low velocity impacts between macroscopic rigid‐plastic identical spherical particles, depends primarily on the initial relative velocity, Youngs Modulus, particle size and the plastic yield stress. Surface tension becomes important for impacts between nano‐scale particles. The major implications of surface tension for impacts at the nano‐scale are discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of asymmetric effects for shape memory alloys
Authors: Wilmanns Stefan , Mahnken Rolf
Published: October 2008

Experimental results of shape memory alloys show a pronounced asymmetric behaviour between tension, compression and shear. For simulation of these effects in the constitutive equations different transformation strain tensors are introduced. These are related to the different variants for the multi‐variant‐ and detwinned‐martensite as a consequence of different stress states. In the framework of plasticity the concept of stress mode dependent weighting functions is applied in order to characterize the different stress states. Verification of the proposed methodology is succeeded for simulation of the pseudoelastic behaviour of shape memory alloys with different hardening characteristics in tension, compression and shear. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical simulation of flow of viscoelastic fluids
Authors: Wünsch Olaf , Krebs Mathias
Published: October 2008

The paper deals with the numerical calculation of highly viscous, non‐newtonian fluid flows in apparatus of mechanical engineering. We use a differential constitutive equation to approximate the real behaviour of technical fluids like polymer melts. By means of calculated flow examples in two and three dimensional geometries we demonstrate the influence of the non‐newtonian behaviour. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parameter analysis of the structure of matrix pencils by homotopic deviation theory
Authors: Ahmadnasab Morad , Chaitin‐Chatelin Françoise
Published: October 2008

Let A, E ∈ ℂn ×n be two given matrices, where rank E = r < n. Matrix E is written in the form E = UVH where U, V ∈ ℂn ×r have rank r. 0 is an eigenvalue of E with algebraic (resp. geometric) multiplicity m (g = n – r ≤ m).

We consider the pencil Pz = (A – zI) + tE, defined for t ∈ ℂ and depending on the complex parameter z ∈ ℂ. We analyze how its structure [8] evolves as the parameter z varies, by means of conceptual tools borrowed from Homotopic Deviation theory [1, 3]. As an example with z = 0, the structure of the pencil A + tE is determined by Homotopic Deviation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crack propagation calculation using trial cracks
Authors: Bäker Martin
Published: October 2008

We present a method to perform finite element calculations for crack propagation problems with arbitrary crack directions in two dimensions. The crack direction (angle of propagation) is determined by inserting small “trial cracks” at the crack tip. For each trial crack, the domain is remeshed to allow crack propagation between elements. The trial cracks are then opened and the energy release rate is measured. The optimum crack direction (i.e., the crack direction with maximum energy release) is determined by an optimisation procedure. Although the method is computationally expensive due to the need to perform several calculations for each crack increment, it has the advantage that the energy release rate can be calculated even in cases where other methods fail. After explaining the method, it is applied to some test examples. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parametrization for mesoscale ocean transport through random flow models
Authors: Baydil Banu , Kramer Peter R. , Smith Shafer
Published: October 2008

We describe a mathematical approach based on homogenization theory toward representing the effects of mesoscale coherent structures on large‐scale transport in the ocean. We demonstrate the approach on a deterministic and a random model flow. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inverse problem in seismic imaging
Authors: Cameron Maria , Fomel Sergey , Sethian James
Published: October 2008

We address the problem of estimating sound speeds (seismic velocities) inside the earth which is necessary for obtaining seismic images in regular Cartesian coordinates. The main goals are to develop algorithms to convert time migration velocities to true seismic velocities, and to convert time‐migrated images to depth images in regular Cartesian coordinates.

Our main results are three‐fold. First, we establish a theoretical relation between the seismic velocities and the time migration velocities using the paraxial ray tracing theory. Second, we formulate an appropriate inverse problem describing the relation between time migration velocities and depth velocities and show that this problem is mathematically ill‐posed, i.e., unstable to small perturbations. Third, we develop numerical algorithms to solve regularized versions of these equations which can be used to recover smoothed velocity variations. Our algorithms consist of efficient time‐to‐depth conversion algorithms based on Dijkstra‐like Fast Marching Methods, as well as level set and ray tracing algorithms for transforming Dix velocities into seismic velocities. Our algorithms are applied to both two‐dimensional and three‐dimensional problems and we test them on a collection of both synthetic examples and field data. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear modal interactions and low order modeling of a kicked flexible rod
Authors: Cusumano Joseph P.
Published: October 2008

A magnetically kicked flexible‐beam oscillator is studied experimentally. Spectral bifurcation diagrams of the attracting steady states are obtained, and the system is seen to exhibit periodic, quasiperiodic and chaotic responses. The proper orthogonal decomposition (POD) is applied to spatial strain gauge data, and a specific nonlinear two‐mode interaction is shown to be present in all responses. Based on these experimental observations, a two degree of freedom piecewise linear autonomous model is developed, which captures much of the behavior observed in the experiments. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptive high‐resolution simulation of realistic gaseous detonation waves
Authors: Deiterding Ralf
Published: October 2008

The numerical approximation of detonation waves in gaseous combustible mixtures is extremely demanding since a wide range of scales needs to be resolved. A dynamically adaptive high‐resolution finite volume method is described that has enabled accurately resolved computational investigations of the transient behavior of regularly oscillating detonations in lowpressure hydrogen‐oxygen mixtures in realistic two‐dimensional geometry. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A level set method for 3D low frequency electromagnetic imaging with applications in geophysical prospecting
Authors: Dorn Oliver , Villegas Rossmary
Published: October 2008

We propose a novel shape reconstruction technique for controlled source 3D low frequency electromagnetic induction tomography which uses a level set representation of the shapes. The main application which we have in mind in this paper is geophysical prospecting, in particular the monitoring of reservoir flooding processes in secondary oil recovery and the investigation of conductive geophysical structures at a depth of up to a few hundred metres. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptive algorithms for phase field models of some interface problems
Authors: Du Qiang
Published: October 2008

We present our on‐going works with current and former colleagues at Penn State (L.Q. Chen, W.M. Feng, S. Hu, Z.K. Liu, P. Yu, X. Wang and J. Zhang) on the numerical algorithms for the phase field simulations of some interface problems, ranging from microstructure evolution in multicomponent alloy to multicomponent lipid vesicles. We discuss recent development of highly adaptive computational algorithms for large scale phase field simulations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prediction of the disposition of a P‐gp substrate in wild‐type and knockout mice tissues: Development of a physiologically based pharmacokinetic (PBPK) model and its global sensitivity analysis
Authors: Fenneteau F. , Li J. , Couture L. , Turgeon J. , Nekka F.
Published: October 2008

In order to improve understanding and prediction of drug disposition prior to in vivo experiments, we aimed to develop a PBPK model that accounts for the involvement of P‐glycoprotein activity and expression in mouse brain, liver, kidney and heart tissues. Model parameters of P‐gp activity and drug diffusion were mainly extrapolated from in vitro data. Model simulations, compared with tissue concentration of 3H‐domperidone intravenously administered toWT and KO mice, suggest the involvement of additional membrane transporters in heart and brain tissues. The global sensitivity analysis showed that the variability of model predictions is related to the variability of the unbound fraction to plasma protein, whereas the uncertainty of the model predictions is associated with the uncertainty of the parameters related to P‐gp genetic expression, and to the activity of additional transporters in heart and brain tissues. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of the discrete element method to model cohesive materials
Authors: Gaugele Timo , Storchak Michael , Eberhard Peter
Published: October 2008

In this contribution we show how the discrete element method (DEM) can be applied to model cohesive materials which exhibit ductile behaviour by introducing connective elements that can bear a certain load. The modelled material is verified by simulating a orthogonal cutting process which is compared to experimental results. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A computational framework of three dimensional configurational‐force‐driven crack propagation
Authors: Gürses Ercan , Miehe Christian
Published: October 2008

A variational formulation of quasi‐static brittle fracture is considered and a new finite‐element‐based computational framework is developed for propagation of cracks in three‐dimensional bodies. We outline a consistent thermodynamical framework for crack propagation in elastic solids and show that the crack propagation direction associated with the classical Griffith criterion is identified by the material configurational force which maximizes the local dissipation at the crack front. The evolving crack discontinuity is realized by the doubling of critical nodes and triangular interface facets of the tetrahedral mesh. The crucial step for the success of the procedure is its embedding into an r‐adaptive crack‐facet reorientation procedure based on configurational‐force‐based indicators in conjunction with crack front constraints. We further propose a staggered algorithm which minimizes the stored energy at frozen crack state followed by the successive crack releases at frozen deformation. This constitutes a sequence of positive definite subproblems with successively decreasing overall stiffness, providing a very robust algorithmic setting in the postcritical range. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the modeling of thermo‐electro‐magneto‐mechanical solids at finite strains
Authors: Kiefer Björn , Rosato Daniele , Miehe Christian
Published: October 2008

A short overview of the mechanics of electromagnetic continua at finite strains is provided in this paper. In this framework objective thermodynamically‐consistent constitutive relations are formulated for materials that exhibit thermo‐electro‐magnetomechanical coupling. In particular a model for an isotropic hyperelastic magnetic solid is considered, which finds application for magnetorheological elastomers (MRE). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimal control for supply network models: adjoint calculus
Authors: Göttlich Simone , Herty Michael , Kirchner Claus
Published: October 2008

We consider a PDE based supply network model with controllable nodes for which we derive an optimal control problem and present an adjoint‐based solution technique. The supply network has two basic building blocks: The dynamics in a supplier is governed by a PDE and the behavior inside a queue is described by an ODE. The network model provides a framework to couple these equations at nodes. We introduce controls at so‐called dispersing nodes and discuss suitable cost functionals leading to optimal control problems which we solve by a projected gradient method. The gradient information can be obtained from adjoint equations which we derive in the context of our supply network model. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Automatic differentiation in meteorology and oceanography
Authors: Korn Peter
Published: October 2008

The physically consistent integration of observational data in dynamical circulation models of the atmosphere/ocean, e.g. for the purpose of predicting the future evolution of the climate system relies on variational data assimilation algorithms. These algorithms are based on the adjoint method of optimal control theory and implemented by Automatic Differentiation (AD) tools. The presence of turbulent phenomena imposes a challenge on AD based methods of adjoint flow control and highlights the role of the computational turbulence model. For the Lagrangian Averaged turbulence model, applied to the 3D Navier‐Stokes equations, we establish well‐posedness of the data assimilation problem. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Experimental and numerical investigations of crimped end fittings
Authors: Kreikemeier Janko , Gabbert Ulrich
Published: October 2008

The paper deals with numerical and experimental investigations of steel made hulls crimped onto glass fibre reinforced plastic rods. The aim is to optimize the crimping procedure to realize maximum pull out forces of the specimens. The numerical simulations were performed with the commercial FEA package ABAQUS. For the contact formulation a Coulomb friction law with a constant friction coefficient was applied. The damage and fracture states within the composite rods due to the crimping process were investigated by scanning electron microscopy. The results obtained were discussed and an outlook to further work is given. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Curve fitting with a Sobolev gradient method
Authors: Renka R. J.
Published: October 2008

Consider the problem of constructing a mathematical representation of a curve that satisfies constraints such as interpolation of specified points. This problem arises frequently in the context of both data fitting and Computer Aided Design. We treat the most general problem: the curve may or may not be constrained to lie in a plane; the constraints may involve specified points, tangent vectors, normal vectors, and/or curvature vectors, periodicity, or nonlinear inequalities representing shapepreservation criteria. Rather than the usual piecewise parametric polynomial (B‐spline) or rational (NURB) formulation, we represent the curve by a discrete sequence of vertices along with first, second, and third derivative vectors at each vertex, where derivatives are with respect to arc length. This provides third‐order geometric continuity and maximizes flexibility with an arbitrarily large number of degrees of freedom. The free parameters are chosen to minimize a fairness measure defined as a weighted sum of curve length, total curvature, and variation of curvature. We thus obtain a very challenging constrained optimization problem for which standard methods are ineffective. A Sobolev gradient method, however, is particularly effective. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fast directional multilevel computation for problems with oscillatory kernels
Authors: Engquist Björn , Ying Lexing
Published: October 2008

This paper describes a new directional multilevel algorithm for solving N ‐body or N ‐point problems resulted from integral formulations of wave scattering applications. These problems are difficult since the kernel involved is oscillatory. The starting point of our approach is the observation that the interaction between two point sets has a low rank separable representation as long as they follow an angular separation condition. In order to construct the separable representations numerically, we introduce an efficient procedure based on random sampling. Finally, the resulting low rank representations are embedded in a hierarchical multiscale and multidirectional framework to accelerate the far field computation in an optimal way. This new algorithm has O (N log N) complexity, and the numerical results demonstrate its effectiveness in engineering examples. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection and analysis of mammary gland stem cells
Authors: Stingl J
Published: October 2008

Emerging evidence from a variety of tissue types, including the mammary gland, suggests that normal stem and progenitor cells are the likely targets for malignant transformation, and that these transformed cells can function as cancer stem cells that drive tumour growth. In order to develop therapies that target these cancer stem cells, it is essential to determine the molecular mechanisms that regulate the growth and differentiation of these cells and their normal counterparts. To this end, a number of quantitative robust clonal assays have been developed that can detect the presence of human and mouse mammary stem and progenitor cells. These assays, when used in conjunction with cell‐sorting strategies, have permitted the prospective isolation and characterization of a variety of cell types, including stem cells. Evidence to date indicates that these stem cells exhibit properties of basal mammary cells, possess extensive self‐renewal properties, and are capable of generating a large number of phenotypically‐distinct progenitor cells, many of which display characteristics of luminal cells. This review article will focus on the assays used to detect mammary stem and progenitor cells, some of the properties of these cells and their progeny and how they relate to the cancer stem cells that drive breast tumour growth. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Oestrogen‐mediated phosphorylation and stabilization of BRCA2 protein in breast
Authors: Malone JL , Nelson AC , Lieberman R , Anderson S , Holt JT
Published: October 2008

Disease‐associated BRCA2 mutations typically result in protein truncations that delete the phosphorylation‐regulated S3291 BRCA2 domain that interacts with Rad51. BRCA2 hereditary breast cancers are usually ER+, differing from BRCA1 hereditary cancers, which are usually ER−. We studied BRCA2 protein expression and S3291 phosphorylation in normal breast tissues and in sporadic breast cancers and observed that BRCA2 is expressed and phosphorylated in normal breast and 10 ER+ breast cancers but not in 10 ER− breast cancers. In order to study this correlation between ER and BRCA2 expression, we studied ER+ breast cancer cell lines. We found that a rapid increase in BRCA2 S3291 phosphorylation occurs following 17‐β‐oestradiol (E2) treatment. This increase seen in BRCA2 total and phospho‐S3291 protein levels was found to be unaffected with cycloheximide pre‐treatment, but decreased following tamoxifen, ICI 182,780 or roscovitine treatment. This suggests a requirement for ER and cdk (cyclin‐dependent kinase) in mediating the increased protein levels. MCF7 cell cycle distribution analysis following E2, in both the presence and absence of roscovitine (a cdk inhibitor), did not demonstrate any changes during an 8 h period, which further supports our hypothesis that mitogenic effects of E2 are not predominant at early time points. Studies with MG132 proteasome inhibitor and siRNA to skp2 support a model in which skp2‐mediated proteasomal degradation of BRCA2 rapidly degrades BRCA2 protein in the absence of hormone treatment, which likely inhibits this pathway. E2 was shown to improve survival of MCF7 cells upon radiation treatment and roscovitine partially reversed this effect. We have demonstrated that BRCA2 protein is specifically expressed in ER+ breast cancers and are investigating a pathway that may show a link between E2 action and BRCA2 protein function in breast cancer. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Cutaneous pseudolymphoma: An unusual presentation of a scalp mass
Authors: Nnebe Nkechinyelu V. , Woon Carolyn , Haines Stephen , Dayton Vanessa , Weigel Brenda J.
Published: October 2008

The term cutaneous pseudolymphoma (CPL), an accumulation of lymphocytes in response to a foreign antigen or unknown stimuli lacks specificity, and has been used when neither cause nor mechanism for the lymphocytic proliferation has been identified. Cases of childhood CPL are rare and require extensive investigation because of their potential for malignant transformation. We report a case of a child with a scalp mass diagnosed as CPL. Pediatr Blood Cancer 2009;52:283–285. © 2008 Wiley‐Liss, Inc.
Healthcare utilization and expenditures for low income children with sickle cell disease
Authors: Raphael Jean L. , Dietrich Craig L. , Whitmire Deborah , Mahoney Donald H. , Mueller Brigitta U. , Giardino Angelo P.
Published: October 2008

Background

While multiple studies have examined the healthcare burden of sickle cell disease (SCD) in adults, few have specifically focused on healthcare utilization and expenditures in children. The objective of this study was to characterize the healthcare utilization and costs associated with the care of low‐income children with SCD in comparison to other children of similar socioeconomic status.

Procedure

For the study period, 2004–2007, we conducted a retrospective, cross‐sectional descriptive analysis of administrative claims data from a managed care plan exclusively serving low‐income children with Medicaid and the State Children's Health Insurance Plan (SCHIP). Patient demographics, continuity of insurance coverage, healthcare utilization, and expenditures were collected for all children enrolled with SCD and the general population within the health plan for comparison.

Results

On average, 27% of members with SCD required inpatient hospitalization and 39% utilized emergency care in a given calendar year. Both values were significantly higher than those of the general health plan population (P < 0.0001). Across the study period, 63% of members with SCD averaged one well child check per year and 10% had a minimum of one outpatient visit per year to a hematologist for comprehensive specialty care.

Conclusions

Low‐income children with SCD demonstrate significantly higher healthcare utilization for inpatient care, emergency center care, and home health care compared to children with similar socio‐demographic characteristics. A substantial proportion of children with SCD may fail to meet minimum guidelines for outpatient primary and hematology comprehensive care. Pediatr Blood Cancer 2009;52:263–267. © 2008 Wiley‐Liss, Inc.
Rhabdomyosarcoma masquerading as acute leukemia
Authors: Shinkoda Yuichi , Nagatoshi Yoshihisa , Fukano Reiji , Nishiyama Kenichi , Okamura Jun
Published: October 2008

Rhabdomyosarcoma (RMS) masquerading as acute leukemia (AL) is very rare. We describe three cases with RMS without any symptoms of solid tumors. Bone marrow (BM) showed approximately 95% of blast‐like abnormal cells, lacking almost all of the surface antigens of myeloid‐ and lymphoid‐lineage. The immunohistochemistry revealed positive of the cells for actin, desmin and myoglobin. It is important to examine BM samples by immunohistochemistry, when a flow cytometric analysis reveals an unusual presentation. Pediatr Blood Cancer 2009;52:286–287. © 2008 Wiley‐Liss, Inc.
Vincristine induced peripheral neuropathy potentiated by voriconazole in a patient with previously undiagnosed CMT1X
Authors: Porter Christopher C. , Carver Amy E. , Albano Edythe A.
Published: October 2008

Peripheral neuropathy is a well‐known side effect of vincristine, a micro‐tubule inhibitor commonly used to treat malignancies. Severe neurologic adverse events can occur in patients with Charcot‐Marie‐Tooth disease (CMT) treated with vincristine. Voriconazole is an antifungal agent used increasingly in children with malignancy. Because of its metabolism by hepatic p450 enzymes, voriconazole may inhibit the clearance of many medications, including vincristine. We report a case of vincristine related neuropathy that was exacerbated by voriconazole in a patient with previously undiagnosed, X‐linked CMT. Pediatr Blood Cancer 2009;52:298–300. © 2008 Wiley‐Liss, Inc.
Vancomycin‐resistant enterococcus in pediatric oncology patients: An analysis of potential consequences of colonization and infection
Authors: Kosack Amanda , Riedel Elyn , Kiehn Timothy E. , Small Trudy N. , Wexler Leonard H. , Dunkel Ira J.
Published: October 2008

A retrospective analysis of 57 pediatric oncology patients with a baseline positive vancomycin‐resistant enterococcus (VRE) culture who subsequently received chemotherapy and/or radiation therapy was performed. The incidence of subsequent VRE infection was calculated using a competing risk analysis accounting for death from non‐VRE causes as a competing risk. Ten patients had subsequent VRE infection. The cumulative incidence of subsequent infection was 14% (7–27%, 95% confidence interval) at 1 year and 16% (9–29%, 95% confidence interval) at 2 years. None of the hypothesized risk factors appeared to differ between patients who developed a subsequent infection and those who did not. Pediatr Blood Cancer 2009;52:300–302. © 2008 Wiley‐Liss, Inc.
Coupling PV and CAES power plants to transform intermittent PV electricity into a dispatchable electricity source
Authors: Mason James , Fthenakis Vasilis , Zweibel Ken , Hansen Tom , Nikolakakis Thomas
Published: October 2008

This study investigates the transformation of photovoltaic (PV) electricity production from an intermittent into a dispatchable source of electricity by coupling PV plants to compressed air energy storage (CAES) gas turbine power plants. Based on historical solar irradiation data for the United States' south western states and actual PV and CAES performance data, we show that the large‐scale adoption of coupled PV–CAES power plants will likely enable peak electricity generation in 2020 at costs equal to or lower than those from natural gas power plants with or without carbon capture and storage systems. Our findings also suggest that given the societal value of reducing carbon dioxide and the sensitivity of conventional generation to rising fossil fuel prices, this competitive crossover point may occur much sooner. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and stereochemical analysis of some norephedrine‐derived isoxazolidines
Authors: Moosa Basem A. , Wazeer Mohamed I. M. , Fettouhi Mohammed B. , Ali Shaikh A.
Published: October 2008

The diastereoselectivity in the cycloaddition reactions of several mono‐ and disubstituted alkenes with a (‐)norephedrine‐derived methylenenitrone has been investigated. The stereochemical analysis of the addition products (i.e., isoxazolidines) has been carried out by X‐ray, NMR, and chemical conversions. The NMR spectra of the isoxazolidines at low temperatures indicated the presence of either a single or a predominant invertomer. The stereochemistry of the invertomers and nitrogen inversion barriers are determined using complete line‐shape analysis and their dependence on solvent is discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Impact of wind bogus and cloud‐ and rain‐affected SSM/I data on tropical cyclone analyses and forecasts
Authors: Montroty Rémi , Rabier Florence , Westrelin Samuel , Faure Ghislain , Viltard Nicolas
Published: October 2008

In the context of its responsibilities as a Regional Specialised Meteorological Centre (RSMC) for the Southwest Indian Ocean, Météo‐France operates a tropical cyclone warning centre which sends advisories to all the concerned countries in the area. In assistance to the forecasters and as part of the operational suite for the short‐range forecasts, a limited‐area model (ALADIN Réunion) is run with four daily analyses. Assimilated observations include conventional observations – radiosondes, buoys, surface stations, aircraft reports, upper‐wind reports – and satellite observations. The latter include QuikSCAT surface winds, atmospheric motion vectors from geostationary satellites, and radiances from polar‐orbiting satellites. Assimilation of satellite radiance data is done in clear‐sky conditions, and thus cannot be used in the vicinity of tropical cyclones. Two new sources of pseudo‐observations are investigated that can bring new information content to those regions: Total Column Water Vapour (TCWV) pseudo‐observations deduced from cloudy/rainy SSM/I data, as well as a 3D wind bogus. The TCWV algorithm is obtained from SSM/I brightness temperatures through a simple statistical regression from the 1D‐Var analyses of the European Centre for Medium‐Range Weather Forecasts, which are derived from complex inversion methods using moist physics and radiative transfer models. The 3D wind bogus is derived from structural information contained in the tropical cyclone advisories issued by the RSMC and contains a low‐level vortex composed of two concentric rings of eight winds each, at each of the surface, 850, 700 and 500 hPa levels. Forecast scores and fit of the model to the observations are improved and indicate a positive impact of those new datasets. Structural validation is investigated through the comparison of model and TMI ‘observed’ rain rates: it is found that assimilating and cycling cloudy/rainy TCWV helps achieve more realistic cyclonic features. Copyright © 2008 Royal Meteorological Society
Ensemble simulations of the cold European winter of 2005‐2006
Authors: Scaife A. A. , Knight J. R.
Published: October 2008

There is only limited understanding of the processes driving year‐to‐year variability in European winter climate and the skill of seasonal forecasts for Europe in winter is generally low. The winter of 2005‐2006 is a useful case‐study because it was the coldest winter in large parts of western Europe for over a decade, and the coldest in central England since 1995‐1996. Here, we present results of experiments with a range of general circulation models to investigate the importance of both the Atlantic Ocean and stratospheric circulation in producing the unusually cold winter of 2005‐2006. We use models with different combinations of horizontal and stratospheric vertical resolution, allowing the sensitivity of the response to model formulation to be tested. The response to Atlantic sea‐surface temperature (SST) anomalies is improved in a more recent model with higher horizontal resolution. The results show that both Atlantic SSTs and the January 2006 sudden stratospheric warming are likely to have contributed to the cold 2005‐2006 European winter. © Crown Copyright 2008. Reproduced with the permission of HMSO. Published by John Wiley & Sons Ltd.
Differences in the lower troposphere in two‐ and three‐dimensional cloud‐resolving model simulations of deep convection
Authors: Petch J. C. , Blossey P. N. , Bretherton C .S.
Published: October 2008

This short note discusses key deficiencies in two‐dimensional (2D) cloud‐resolving model (CRM) simulations. Results differ significantly from three‐dimensional (3D) simulations in the low‐level humidity structure and associated fields. These differences are consistent across two different CRMs that differ substantially in their thermodynamic and microphysical formulations. Our analysis suggests than the near‐surface humidity structure depends on moisture transport in clouds, and we suggest that differences in entrainment between 2D and 3D simulations lead to substantial differences in both cloud amount and moisture transport by the clouds at low levels. When compared with 3D, less entrainment in 2D reduces the likelihood that convective updraughts terminate and moisten the lower troposphere. The differences between the 2D and 3D are significant if the CRM is to be used as a reference for comparison against numerical weather prediction (NWP) or climate models. Copyright © 2008 Royal Meteorological Society, Crown Copyright 2008
A new quantization rule to the energy spectra for modified hyperbolic‐type potentials
Authors: Dong Shi‐Hai
Published: October 2008

A new exact quantization rule simplifies the calculation of the energy levels for exactly solvable quantum systems. The energy spectra of the modified hyperbolic‐type potentials are carried out by this rule. These potentials include the modified Scarf, Rosen–Morse, second Pöschl‐Teller and Eckart potentials. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Theoretical investigation of the stability, electronic and magnetic properties of thiolated single‐wall carbon nanotubes
Authors: Denis Pablo A.
Published: October 2008

The addition of SH and OH groups to single‐wall carbon nanotubes (SWCNTs) was investigated employing first principles calculations. In the case of the semiconducting (10, 0) SWCNT the SWCNT‐SH binding energy is weak, 2–4 kcal/mol. However, for the metallic (5, 5) SWCNT it is larger, 7–9 kcal/mol. Thus metallic SWCNTs seem to be more reactive to SH than the semiconducting ones. Indeed, the (6, 6) SWCNT is more reactive to SH than the (10, 0) SWCNT, by 2–3 kcal/mol, something that can be explained only considering the electronic structure of the tube, because the (6, 6) has a larger diameter. The binding energies are larger for the addition of the OH group, 25 and 30 kcal/mol for the (10, 0) and (5, 5) SWCNTs, respectively. When a single OH or SH group is attached to the metallic SWCNTs, we observe important changes in the DOS at the Fermi level. However, when multiple SH groups are attached, the changes in the electronic and magnetic properties depend on the position of the SH groups. The small binding energy found for the SH addition indicates that the successful functionalization of SWCNTs with SH, SCH3, and S(CH2)nSH groups is mostly due to the presence of defects created after acid treatment and to a minor extent by the metallic tubes present in the samples. Perfect semiconducting SWCNTs showed very low reactivity against the SH group. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Stable carbon and nitrogen isotope analysis of avian uric acid
Authors: Bird Michael I. , Tait Elaine , Wurster Christopher M. , Furness Robert W.
Published: October 2008

We report results obtained using a new technique developed to measure the stable‐isotope composition of uric acid isolated from bird excreta (guano). Results from a diet‐switch feeding trial using zebra finches suggest that the δ13C of uric acid in the guano equilibrates with the diet of the bird within 3 days of a change in diet, while the equilibration time for δ15N may be longer. The average carbon isotope discrimination between uric acid and food before the diet switch was +0.34 ± 1‰ (1σ) while after the diet switch this increased slightly to +0.83 ± 0.7‰ (1σ). Nitrogen isotope discrimination was +1.3 ± 0.3‰ (1σ) and +0.3 ± 0.3‰ (1σ) before and after the diet switch; however, it is possible that the nitrogen isotope values did not fully equilibrate with diet switch over the course of the experiment. Analyses of other chemical fractions of the guano (organic residue after uric acid extraction and non‐uric acid organics solubilised during extraction) suggest a total range of up to 3‰ for both δ13C and δ15N values in individual components of a single bulk guano sample. The analysis of natural samples from a range of terrestrial and marine species demonstrates that the technique yields isotopic compositions consistent with the known diets of the birds. The results from natural samples further demonstrate that multiple samples from the same species collected from the same location yield similar results, while different species from the same location exhibit a range of isotopic compositions indicative of different dietary preferences. Given that many samples of guano can be rapidly collected without any requirement to capture specimens for invasive sampling, the stable‐isotope analysis of uric acid offers a new, simple and potentially powerful tool for studying avian ecology and metabolism. Copyright © 2008 John Wiley & Sons, Ltd.
Simultaneous analysis of thirteen diuretics residues in bovine milk by ultra‐performance liquid chromatography/tandem mass spectrometry
Authors: Shao Bing , Zhang Jing , Yang Yi , Meng Juan , Wu Yongning , Duan Hejun
Published: October 2008

A simple, rapid, sensitive and specific method used to screen and confirm multi‐class diuretics residues in whole bovine milk is described. Thirteen drugs of four different classes including carbonic anhydrase inhibitors, loop, thiazide and potassium‐sparing diuretics were extracted from whole milk by acetonitrile followed by further purification with hexane. The analytes were separated using an ACQUITY UPLC™ BEH C18 column and detected by electrospray ionization tandem mass spectrometry (ESI‐MS/MS). MS data acquisition was performed by a time‐scheduled multiple reaction monitoring program, selecting two ion transitions for each target compound. The overall average recoveries based on matrix‐fortified curves fortified with diuretics at three levels ranged from 80.6 to 108.8% with the coefficients of variation ranging from 2.6 to 19.7% (n = 6). The limits of quantitation (LOQs) of diuretics in bovine milk were 5.0 µg/kg for spironolactone and 0.5 µg/kg for other analytes, respectively. Copyright © 2008 John Wiley & Sons, Ltd.
An improved method for the measurement of the isotope ratio of ethanol in various samples, including alcoholic and non‐alcoholic beverages
Authors: Hattori Ryota , Yamada Keita , Hasegawa Kaori , Ishikawa Yumi , Ito Yuji , Sakamoto Yuji , Yoshida Naohiro
Published: October 2008

The isotope ratios of ethanol, an important constituent or ingredient of some foods and various beverages and fuels, provide information about biological and geographical origin and quality. We have developed an improved method for measuring the isotope ratio of ethanol in various samples by gas chromatography‐high temperature conversion or combustion‐isotope ratio mass spectrometry (GC‐TC/C‐IRMS) with headspace solid‐phase microextraction (HS‐SPME). A HS‐SPME method was developed by optimizing several different parameters, including salt addition, incubation temperature and time, and extraction time. The HS‐SPME method enabled us to determine the isotope ratio at low ethanol concentrations (0.08 mM) in 50 min with good precision (±0.3‰ for δ13C and ±5‰ for δD). An advantage of this technique is that it can be adapted for use with samples which have high viscosity and contain many matrix compounds, such as alcoholic and non‐alcoholic beverages. Copyright © 2008 John Wiley & Sons, Ltd.
Delay‐dependent stability and stabilization of neutral time‐delay systems
Authors: Sun Jian , Liu G. P. , Chen Jie
Published: October 2008

This paper is concerned with the problem of stability and stabilization of neutral time‐delay systems. A new delay‐dependent stability condition is derived in terms of linear matrix inequality by constructing a new Lyapunov functional and using some integral inequalities without introducing any free‐weighting matrices. On the basis of the obtained stability condition, a stabilizing method is also proposed. Using an iterative algorithm, the state feedback controller can be obtained. Numerical examples illustrate that the proposed methods are effective and lead to less conservative results. Copyright © 2008 John Wiley & Sons, Ltd.
Finding pearls: Psychometric reevaluation of the Simpson–Troost Attitude Questionnaire (STAQ)
Authors: Owen Steven V. , Toepperwein Mary Anne , Marshall Carolyn E. , Lichtenstein Michael J. , Blalock Cheryl L. , Liu Yan , Pruski Linda A. , Grimes Kandi
Published: October 2008

The Simpson–Troost Attitude Questionnaire (STAQ) was developed as part of a study to assess adolescent commitment to and achievement in science. For this psychometric reappraisal of the 57‐item STAQ, data were analyzed from a convenience sample of 1,754 secondary students. Confirmatory and exploratory factor analyses were applied, and results suggested that the STAQ can be shortened from 57 to 22 items spanning five revised dimensions. These five dimensions were arranged into an exploratory structural equation model, which showed some grade and gender differences and strong associations among classroom environment, self‐directed effort, and science affect. Findings raise the potential for teacher professional development to improve science classroom activities, and influence student self‐directed effort and science affect. © 2008 Wiley Periodicals, Inc. Sci Ed 92:1076–1095, 2008