bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diagnostic strategy for familial and sporadic cases of neuropathy associated with 17p11.2 deletion
Authors: Infante Jon , García Antonio , Combarros Onofre , Mateo José I. , Berciano José , Sedano María J. , Gutiérrez‐Rivas Eduardo J. , Palau Francesc 
Published: August 2002

AbstractClinical, electrophysiologic and molecular studies were performed on at‐risk members of 14 families with hereditary neuropathy with liability to pressure palsies (HNPP), in order to detect asymptomatic carriers of the 17p11.2 deletion. Sporadic cases due to de novo deletion accounted for 21% of the investigated HNPP families. Approximately one half of deletion carriers were asymptomatic and did not display significant signs on clinical examination. The electrophysiologic hallmark in both symptomatic and asymptomatic deletion carriers was the presence of a nonuniform sensorimotor demyelinating polyneuropathy with conduction abnormalities preferentially located at common entrapment sites and distal nerve segments. A perfect correlation was found between the molecular and electrophysiologic analyses. A reliable screening method to detect clinically unaffected carriers of the deletion in families with HNPP was the evaluation of motor conduction in at least two nerves across usual entrapment sites, especially the ulnar nerve at the elbow, and evaluation of sensory conduction in the sural nerve. In sporadic cases due to a de novo deletion, electrophysiologic studies were suggestive but not sufficient for the diagnosis, and molecular analysis represented the most sensitive diagnostic tool. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1149–1155, 2001
Three‐dimensional finite element analysis of lined tunnels
Authors: Augarde C. E. , Burd H. J. 
Published: August 2002

AbstractThis paper describes finite element procedures that have been developed to model the ground movements that occur when a shallow tunnel is installed in a clay soil. This study is part of a wider project concerned with the development of new methods to predict the likely extent of damage to surface structures caused by nearby shallow tunnelling. This particular paper, however, is concerned only with the numerical model of tunnel installation. The structural liner is an important component of this tunnel installation model; two different ways of modelling the liner (based on continuum elements and shell elements) are discussed in the paper. A test problem consisting of the installation of a lined tunnel in an elastic continuum is used to investigate the merits of these different approaches. When continuum elements are used to model the liner, the numerical results agree well with an analytical solution to the problem. When shell elements are used to model the liner, however, the results were found to be significantly influenced by the particular formulation adopted for the shell elements. Example analyses, involving incremental tunnel construction in a clay soil where the soil is modelled using a kinematic hardening plasticity model, are described. These analyses confirm that a thin layer of continuum elements may be used, satisfactorily, to model tunnel linings in a soil–structure interaction analysis of this sort. Copyright © 2001 John Wiley & Sons, Ltd.
Effect of element size on the static finite element analysis of steep slopes
Authors: Ashford Scott A. , Sitar Nicholas 
Published: August 2002

AbstractThe accuracy of the computed stress distribution near the free surface of vertical slopes was evaluated in this study as a function of the element size, including aspect ratio. To accomplish this objective, a parametric study was carried out comparing stresses computed using the finite element method (FEM) to those obtained from a physical model composed of photoelastic material. The results of the study indicate a reasonable agreement between a gelatin model and the FEM model for shear stresses, and an overall good agreement between the two models for the principal stresses. For stresses along the top of the slope, the height of the element tends to be more important than width or aspect ratio, at least for aspect ratios up to 4. In all cases, the greatest difference between the two models occurs in the vicinity of the slope. Specifically, if H is defined as the slope height, an element height of H/10 appears to be adequate for the study of stresses deep within the slope, such as for typical embankment analyses. However, for cases where tensile stresses in the vicinity of the slope face which are critical, such as for the stability analysis of steep slopes, element heights as small as H/32, or higher‐order elements, are necessary. Copyright © 2001 John Wiley & Sons, Ltd.
Solute transport through a deforming porous medium
Authors: Peters Glen P. , Smith David W. 
Published: August 2002

AbstractSolute transport through a porous medium is typically modelled assuming the porous medium is rigid. However, many applications exist where the porous medium is deforming, including, municipal landfill liners, mine tailings dams, and land subsidence. In this paper, mass balance laws are used to derive the flow and transport equations for a deforming porous medium. The equations are derived in both spatial and material co‐ordinate systems. Solute transport through an engineered landfill liner is used as an illustrative example to show the differences between the theory for a rigid porous medium, and small and large deformation analysis of a deforming porous medium. It is found that the large deformation model produces shorter solute breakthrough times, followed by the small deformation model, and then the rigid porous medium model. It is also found that it is important to include spatial and temporal void ratio variations in the large deformation analysis. It is shown that a non‐linear large deformation model may greatly reduce the solute breakthrough time, compared to a standard transport analysis typically employed by environmental engineers. Copyright © 2002 John Wiley & Sons, Ltd.
Identifying cut‐off scores with neural networks for interpretation of the incontinence impact questionnaire
Authors: Corcos Jacques , Behlouli Hassan , Beaulieu Sylvie 
Published: August 2002

AbstractWe propose to determine cut‐off scores for the Incontinence Impact Questionnaire (IIQ) based on the neural network (NN) approach. These cut‐off scores should discriminate between patients having poor, moderate, or good quality of life (QoL) secondary to their incontinence problems. Data from two prospectively completed QoL questionnaires, the IIQ (n = 237) and the MOS 36‐Item Short‐Form Health Survey (SF‐36) (n = 237), were analyzed using NN and conventional statistical tools. Kohonen networks identified three distinct clusters of IIQ scores. The three clusters represent the full spectrum of possible scores on the IIQ. We interpreted these clusters as reflecting good, moderate, and poor QoL. We estimated that a score of less than 50 on the IIQ would be representative of good QoL, between 50 and 70 would be moderate QoL, and greater than 70 would be indicative of poor QoL. Validation with the SF‐36 data confirmed these categories. The present study demonstrated that the NN approach is opening new areas in the interpretation and clinical usefulness of QoL questionnaires. NN allowed the identification of three levels of QoL and should be useful in clinical decision making. Neurourol. Urodynam. 21:198–203, 2002. © 2002 Wiley‐Liss, Inc.
Assessment of the intrinsic urethral sphincter component function in postprostatectomy urinary incontinence
Authors: Pfister Christian , Cappele Olivier , Dunet Frederick , Bugel Hubert , Grise Philippe 
Published: August 2002

AbstractPostprostatectomy incontinence remains a disabling condition. Sphincter injury, detrusor instability, and decreased bladder compliance have been previously reported as major factors. The aim of this study was to evaluate the urethral sphincter intrinsic component, which may provide passive continence. A urodynamic evaluation was performed in 20 patients undergoing a radical retropubic prostatectomy in the preoperative period and 3 months after surgery. Patients with disabled urinary incontinence underwent a new urodynamic evaluation 6 months later. The urethral pressure profile was measured just before, then 10, 20, and 30 minutes after the injection of 0.5 mg/kg moxisylyte chlorhydrate, an alpha adrenergic blocker. Three different pressure components were defined in urethral sphincter capacity: baseline, adrenergic, and voluntary. A postoperative intrinsic urethral sphincter pressure component was found in 17 patients and its value was under 6 cm H2O in five cases of severe incontinence. No significant difference was observed for these patients on urethral profile components 6 months later. In contrast, in cases of significant intrinsic component value, no incontinence was observed in most patients. Passive continence after radical prostatectomy should be a matter of concern and may also explain paradoxical incontinence, despite high voluntary urethral pressure obtained after reeducation. A follow‐up evaluation of the intrinsic sphincter component is suggested, by using an alpha receptor blockage test during urodynamic studies in the management of patients with postprostatectomy incontinence. Neurourol. Urodynam. 21:194–197, 2002. © 2002 Wiley‐Liss, Inc.
A strategic view for the development of E‐Business
Authors: Bakry Saad Haj , Bakry Fahed Haj 
Published: August 2002

AbstractE‐business is becoming increasingly important for countries, organizations and individuals, as it gives them efficiency, and as it integrates them together, and with the world at large. This paper aims at providing a strategic view for the development of e‐business. Copyright © 2001 John Wiley & Sons, Ltd.
Robust location problems with pos/neg weights on a tree
Authors: Burkard Rainer E. , Dollani Helidon 
Published: August 2002

AbstractIn this paper, we consider different aspects of robust 1‐median problems on a tree network with uncertain or dynamically changing edge lengths and vertex weights which can also take negative values. The dynamic nature of a parameter is modeled by a linear function of time. A linear algorithm is designed for the absolute dynamic robust 1‐median problem on a tree. The dynamic robust deviation 1‐median problem on a tree with n vertices is solved in O(n2 α(n) log n) time, where α(n) is the inverse Ackermann function. Examples show that both problems do not possess the vertex optimality property. The uncertainty is modeled by given intervals, in which each parameter can take a value randomly. The absolute robust 1‐median problem with interval data, where vertex weights might also be negative, can be solved in linear time. The corresponding deviation problem can be solved in O(n2) time. © 2001 John Wiley & Sons, Inc.
Volatile general anesthetics reveal a neurobiological role for the white and brown genes of Drosophila melanogaster
Authors: Campbell Joseph L. , Nash Howard A. 
Published: August 2002

AbstractMolecular and cellular evidence argues that a heterodimer between two ABC transporters, the White protein and the Brown protein, is responsible for pumping guanine into pigment‐synthesizing cells of the fruit fly, Drosophila melanogaster. Previous studies have not detected White or Brown outside pigment‐synthesizing cells nor have behavioral effects of null mutants been reported, other than those that are visually dependent. Nevertheless, we show here that exposure to the volatile general anesthetic (VGA) enflurane reveals a difference in neuromuscular performance between wild‐type flies and those that carry a null allele in either the white or brown gene. Specifically, in a test of climbing ability, w1118 or bw1 flies are much less affected by enflurane than are congenic controls. Altered anesthetic sensitivity is still observed when visual cues are reduced or eliminated, arguing that white and brown contribute to neural function outside the eye. This hypothesis is supported by the detection of white message in heads of flies that are genetically altered so as to lack pigment‐producing cells. The w1118 or bw1 mutations also alter the response to a second VGA, halothane, albeit somewhat differently. Under some conditions, the combination of w1118 with another mutation that affects anesthesia leads to a drastically altered phenotype. We consider several ways by which diminished transport of guanine could influence neural function and anesthetic sensitivity. Published 2001 John Wiley & Sons, Inc. J Neurobiol 49: 339–349, 2001
Progesterone receptors and the sexual differentiation of the medial preoptic nucleus
Authors: Quadros Princy S. , Lopez Veronica , De Vries Geert J. , Chung Wilson C. J. , Wagner Christine K. 
Published: August 2002

AbstractThe central component of the medial preoptic nucleus (MPNc) of the rat has served as an excellent model of sexual differentiation. The MPNc is larger in adult males than in females, and its development is regulated by perinatal gonadal hormones. Although testosterone (T) and its metabolite estradiol (E) sexually differentiate this region, the exact mechanism by which they act during development is not known. There is a dramatic sex difference in the expression of progesterone receptors (PR) in the MPN during development; perinatal males express higher levels of PR than females. Additionally, PR expression during this time is dependent on exposure to T. Thus, PR induction may be one mechanism by which T sexually differentiates the MPN. The present study investigated the potential role of PR in the sexual differentiation of the MPNc. Anatomical examination of PR distribution within the MPN of neonatal males revealed the presence of PR immunoreactive cells within the MPNc, suggesting a direct route of action for PR in the development of the MPNc. Additionally, we measured the effects of neonatal RU486 treatment, a progesterone and glucocorticoid receptor antagonist, on subsequent MPNc volume in neonatally T‐treated females and neonatally castrated males, given T. RU486 treatment reduced the MPNc volume of T‐treated females while it increased the volume in T‐treated, neonatally castrated males. These results, taken together with the expression of PR in the MPNc, suggest that PR may influence the sexual differentiation of the MPNc volume. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 24–32, 2002
Activin type II receptors in embryonic dorsal root ganglion neurons of the chicken
Authors: Kos Ksenija , Fine Larry , Coulombe James N. 
Published: August 2002

AbstractActivin induces neuropeptide expression in chicken ciliary ganglion neurons. To determine if activin might also influence neuropeptide expression in developing sensory neurons, we examined whether type II activin receptors are expressed during embryonic development of the chicken dorsal root ganglia (DRG), and also examined the effects of activin on neuropeptide expression in cultured DRG neurons. Using reverse transcription polymerase chain reaction (rtPCR), we detected mRNAs for both the activin receptors type IIA (ActRIIA) and type IIB (ActRIIB) in DRG from embryonic day 7 through posthatch day 1. With in situ hybridization, we found that morphologically identifiable neurons express mRNAs for both ActRIIA and ActRIIB. With developmental age, a subset of neurons that hybridizes more intensely with riboprobes to these receptor mRNAs becomes evident. A similar pattern of expression is observed with immunocytochemical staining using antisera against activin type II receptors. To examine whether embryonic DRG cells respond to activin we treated dissociated cultures of DRG with activin A and assessed the expression of vasoactive intestinal peptide (VIP) and calcitonin gene related peptide (CGRP) mRNAs using semiquantitative rtPCR. Activin treatment results in an increase in VIP mRNA, but does not affect CGRP mRNA levels. These observations indicate that neurons in the embryonic chicken DRG can respond to activin and suggest that activin has the potential to play a role in the development and function of DRG sensory neurons. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 93–108, 2001
A nearly optimal preconditioner for the Navier–Stokes equations
Authors: Hemmingsson‐Frändén Lina , Wathen Andrew 
Published: August 2002

AbstractWe present a preconditioner for the linearized Navier–Stokes equations which is based on the combination of a fast transform approximation of an advection diffusion problem together with the recently introduced ‘BFBTT’ preconditioner of Elman (SIAM Journal of Scientific Computing, 1999; 20:1299–1316). The resulting preconditioner when combined with an appropriate Krylov subspace iteration method yields the solution in a number of iterations which appears to be independent of the Reynolds number provided a mesh Péclet number restriction holds, and depends only mildly on the mesh size. The preconditioner is particularly appropriate for problems involving a primary flow direction. Copyright © 2001 John Wiley & Sons, Ltd.
An algebraic multigrid method for finite element discretizations with edge elements
Authors: Reitzinger S. , Schöberl J. 
Published: August 2002

AbstractThis paper presents an algebraic multigrid method for the efficient solution of the linear system arising from a finite element discretization of variational problems in H0(curl,Ω). The finite element spaces are generated by Nédélec's edge elements.A coarsening technique is presented, which allows the construction of suitable coarse finite element spaces, corresponding transfer operators and appropriate smoothers. The prolongation operator is designed such that coarse grid kernel functions of the curl‐operator are mapped to fine grid kernel functions. Furthermore, coarse grid kernel functions are ‘discrete’ gradients. The smoothers proposed by Hiptmair and Arnold, Falk and Winther are directly used in the algebraic framework.Numerical studies are presented for 3D problems to show the high efficiency of the proposed technique. Copyright © 2002 John Wiley & Sons, Ltd.
Preconditioning of the second‐kind boundary integral equations for 3D eddy current problems
Authors: Schmidlin G. , Fischer U. , Andjelič Z. , Schwab C. 
Published: August 2002

AbstractStarting from the time‐harmonic Maxwell equations at low‐frequency eddy current approximation the H–ϕ formulation is presented. An equivalent system of boundary integral equations of the second kind on the conductor surface (resp. the conductor/dielectric) is derived. Discretizing these equations with a boundary element method (BEM) yields a block linear equation system

\[
\left[\begin{array}{cc} A_{1} & B_{1} \\ \tfrac{\mu}{\mu_{0}}\tilde{B}_{2} & A_{2}\end{array}
\right] \left( \begin{array}{c}
j \\ \sigma \end{array}
\right)=\left(\begin{array}{c}
b_{1} \\ b_{2}\end{array}
\right) \]
with a fully populated stiffness matrix. This system is non‐symmetric and, for large μ/μ0 (of interest in practice) ill‐conditioned. Iterative solvers like GMRES converge very slowly, in general. We propose a new preconditioner which depends on μ. We present numerical results with a serial and parallel version of this preconditioner also on large industrial eddy current problems with compex geometry. The performance of preconditioned GMRES is found to be practically independent of μ/μ0. Copyright © 2001 John Wiley & Sons, Ltd.
Molecular dynamics and multiscale homogenization analysis of seepage/diffusion problem in bentonite clay
Authors: Ichikawa Y. , Kawamura K. , Fujii N. , Nattavut Theramast 
Published: August 2002

AbstractA scheme combining a molecular behaviour and macro‐continuum phenomenon is presented for bentonite clay, which is a key component of a barrier system for disposal and containment of hazardous wastes. On designing a disposal facility we use a macro‐phenomenological model. However the existing model is not sufficiently effective. Bentonite is a microinhomogeneous material. Properties of the saturated bentonite are characterized by montmorillonite and water, called montmorillonite hydrate. Since the crystalline structure of montmorillonite determines the fundamental properties of the montmorillonite hydrate, we analyse its molecular behaviour by applying a molecular dynamics simulation to enquire into the physicochemical properties of the montmorillonite hydrate such as diffusivity of chemical species. For extending the microscopic characteristics of constituent materials to a macroscopic diffusion behaviour of the microinhomogeneous material we apply a multiscale homogenization analysis, especially in order to treat micro‐level of adsorption behaviour. Copyright © 2002 John Wiley & Sons, Ltd.
A general and efficient formulation of fractures and boundary conditions in the finite element method
Authors: Juanes Ruben , Samper Javier , Molinero Jorge 
Published: August 2002

AbstractThe need to assess quantitatively the safety of waste repositories in deep geological media has fostered the development of efficient numerical models of groundwater flow and contaminant transport in fractured media. These models usually account for water flow through fracture zones embedded in a 3D rock matrix continuum. The first formulation of fractures in groundwater flow finite element models was proposed by Kiraly, and later revisited and generalized by Perrochet. From a mathematical viewpoint, fractures can be considered as m‐dimensional manifolds in an n‐dimensional Euclidean space (m⩽n). The key step of this formulation lies in an expression relating the hypersurface element dSm to the infinitesimal local co‐ordinates dξi(i=1,…,m). Here we present a novel proof for this relation using a different approach to that of Perrochet, and explore the efficiency and accuracy of the formulation. It is shown that the aforementioned relation leads to a general and compact formulation which is not only applicable to elements of any dimension (e.g. 1D, 2D and 3D elements in a 3D domain), but also overcomes the cumbersome and case‐specific calculations of traditional approaches. This formulation has been implemented in a versatile finite element program for modelling groundwater flow, solute transport and heat transport in porous and fractured media. The efficiency and accuracy of the proposed formulation has been analysed using a synthetic case dealing with flow and solute transport through a 2D fractured rock block. The proposed formulation, in which fractures are discretized by means of 1D elements is more efficient and accurate than the traditional finite element formulation of discretizing fractures by means of 2D elements. The capability of the proposed formulation to cope with complex systems is illustrated with a case study of groundwater flow induced by the construction of the access tunnel to an underground research laboratory in Äspö (Sweden). The numerical model is able to reproduce the observed records of water levels in boreholes and flow rates into the tunnel. Although the proposed formulation has been implemented and tested within the framework of groundwater flow and solute transport in fractured porous media, it should be of interest for other boundary value problems. Copyright © 2002 John Wiley & Sons, Ltd.
An unconditionally stable and O(τ2 + h4) order L∞ convergent difference scheme for linear parabolic equations with variable coefficients
Authors: Sun Zhi‐Zhong 
Published: August 2002

AbstractM. K. Jain, R. K. Jain, and R. K. Mohanty presented a finite difference scheme of O(τ2 + τh2 + h4) for solving the one‐dimensional quasilinear parabolic partial differential equation, uxx = f(x, t, u, ut, ux), with Dirichlet boundary conditions. The method, when applied to a linear constant coefficient case, was shown to be unconditionally stable by the Von Neumann method. In this article, we prove that the method, when applied to a linear variable coefficient case, is unconditionally stable and convergent with the convergence order O(τ2 + h4) in the L∞‐norm. In addition, we obtain an asymptotic expansion of the difference solution, with which we obtain an O(τ4 + τ2h4 + h6) order accuracy approximation after extrapolation. And last, we point out that the analysis method in this article is efficacious for complex equations. © 2001 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 17:619–631, 2001