bluuebunny/crossref_metadata_2025 huggingface dataset:
Slab scan diffusion imaging
Authors: Maier Stephan E.
Published: August 2002

For maximum robustness of a diffusion‐weighted MR imaging sequence, it is desirable to use a single‐shot imaging method. This article introduces a new single‐shot imaging approach that combines the advantages of multiple spin‐echoes with the technique of line scan diffusion imaging. A slab volume, which can be spatially encoded with fewer phase encodes than a regular field of view, is selected with 2D selective pulses. With the shorter echo train, the sensitivity to field inhomogeneities and chemical shift is thus greatly diminished. Further reduction is achieved by interleaving short gradient echo trains with refocusing spin‐echo pulses. Optimized slice‐selective RF pulses that produce flip angles close to 180° are used to minimize the stimulated echo component. Motion‐related phase shifts, which change polarity with each spin‐echo excitation, will give rise to artifacts that are avoidable by processing even and odd spin‐echoes separately. As with line scan diffusion imaging, the complete field of view is acquired by sequential scanning. Since with each shot several lines of data are collected, a considerable improvement over line scan diffusion imaging in terms of scanning speed is achieved. Diffusion data obtained in phantoms and normal subjects demonstrate the feasibility of this novel approach. Magn Reson Med 46:1136–1143, 2001. © 2001 Wiley‐Liss, Inc.
Mechanisms underlying human motor system plasticity
Authors: Boroojerdi Babak , Ziemann Ulf , Chen Robert , Bütefisch Cathrin M. , Cohen Leonardo G.
Published: August 2002

There has been increased interest in the ability of the adult human nervous system to reorganize and adapt to environmental changes throughout life. This ability has been termed “plasticity.” Plastic changes in the cerebral cortex have been studied: (a) as modifications of sensory or motor cortical representation of specific body parts (cortical maps, body representation level); and (b) as changes in the efficacy of existing synapses or generation of new synapses (neuronal or synaptic level). In this review, we describe paradigms used to study mechanisms of plasticity in the intact human motor system, the functional relevance of such plasticity, and possible ways to modulate it. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 602–613, 2001
The anesthetic propofol modulates gating in paramyotonia congenita mutant muscle sodium channels
Authors: Haeseler Gertrud , Störmer Martina , Mohammadi Bahram , Bufler Johannes , Dengler Reinhard , Piepenbrock Siegfried , Leuwer Martin
Published: August 2002

We examined the effects of propofol on a paramyotonia congenita mutant skeletal muscle sodium channel in vitro, because life‐threatening complications resulting from severe muscle rigidity during induction of anesthesia have been observed using other anesthetics in patients with hereditary sodium channel myopathies. Our hypothesis was that propofol might interact directly with mutant channels, causing enhanced muscle excitability in affected patients. Whole‐cell voltage‐clamp experiments were performed on HEK 293 cells expressing R1448H mutant sodium channels. Propofol blocked sodium inward current at clinical concentrations (5 μmol/L) when depolarizing pulses were started from holding potentials close to the physiological resting potential (−70 mV). Higher propofol concentrations (≥25 μmol/L) accelerated pathologically delayed inactivation kinetics and delayed pathologically enhanced recovery from inactivation. Our in vitro results show that inactivation‐deficient sodium channels are specifically targeted and blocked by propofol. This might reduce enhanced muscle excitability experienced by affected patients in vivo. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 736–743, 2001
Kell and XK immunohistochemistry in McLeod myopathy
Authors: Jung Hans H. , Russo David , Redman Colvin , Brandner Sebastian
Published: August 2002

The McLeod syndrome is an X‐linked neuroacanthocytosis manifesting with myopathy and progressive chorea. It is caused by mutations of the XK gene encoding the XK protein, a putative membrane transport protein of yet unknown function. In erythroid tissues, XK forms a functional complex with the Kell glycoprotein. Here, we present an immunohistochemical study in skeletal muscle of normal controls and a McLeod patient with a XK gene point mutation (C977T) using affinity‐purified antibodies against XK and Kell proteins. Histological examination of the affected muscle revealed the typical pattern of McLeod myopathy including type 2 fiber atrophy. In control muscles, Kell immunohistochemistry stained sarcoplasmic membranes. XK immunohistochemistry resulted in a type 2 fiber‐specific intracellular staining that was most probably confined to the sarcoplasmic reticulum. In contrast, there was only a weak background signal without a specific staining pattern for XK and Kell in the McLeod muscle. Our results demonstrate that the lack of physiological XK expression correlates to the type 2 fiber atrophy in McLeod myopathy, and suggest that the XK protein represents a crucial factor for the maintenance of normal muscle structure and function. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1346–1351, 2001
Simplified orthodromic inching test in mild carpal tunnel syndrome
Authors: Seror Paul
Published: August 2002

This prospective study was undertaken to determine the clinical relevance, reliability, sensitivity, and specificity of the orthodromic inching test with 2‐cm incremental study of the median nerve over the four intracarpal centimeters in 50 control and 50 successive (unselected) patient wrists with mild carpal tunnel syndrome (CTS). In controls, the mean maximum conduction delay per 2 cm (CD/2cm) was 0.445 ± 0.04 ms, and abnormality was defined as at least one CD/2cm exceeding the mean + 2.5 SD of the normal CD/2cm. This yielded a specificity of 98%. In patients with mild unselected CTS, this simplified orthodromic inching test (SOIT) detected the median nerve lesion at the wrist in 47 cases (sensitivity = 94%). The SOIT detected 15 more CTS cases than did the orthodromic median‐ulnar latency difference of the 4th digit (Chi square = 13; P = .002). Thus, the SOIT was as effective as an incremental study every centimeter over 10 cm, and the time required for the test allows its routine use when other electrodiagnostic tests fail to reveal any median nerve impairment. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1595–1600, 2001
Effect of degenerate spherical harmonics and a method for automatic shimming of oblique slices
Authors: Shen Jun
Published: August 2002

Several spherical harmonics degenerate on an oblique plane. Two‐dimensional field mapping of an oblique slice causes ambiguity in determination of the degenerate spherical harmonics terms. Therefore, automatic shimming of oblique slices may lead to erroneous adjustment of shims corresponding to the degenerate spherical harmonics. In this paper an automatic slice shimming technique derived from the FASTMAP method (Gruetter R. Magn. Reson. Med. 1993; 29, 804–811) is proposed. This new method unequivocally determines and corrects all of the first‐ and the second‐order shims for slices of arbitrary orientation. Copyright © 2001 John Wiley & Sons, Ltd.

Abbreviations used:

FOV

field of view

ROI

region of interest

S/N

signal‐to‐noise ratio.
Contraction increases the T2 of muscle in fresh water but not in marine invertebrates
Authors: Meyer Ronald A. , Prior Barry M. , Siles Roxana I. , Wiseman Robert W.
Published: August 2002

Previous studies suggest that the activity‐induced increase in 1H‐NMR transverse relaxation time (T2) observed in mammalian skeletal muscles is related to an osmotic effect of intracellular metabolite accumulation. This hypothesis was tested by comparing T2 (measured by 1H‐NMR imaging at 4.7 T) and metabolite changes (measured by 31P‐NMR spectroscopy) after stimulation in the muscles of a freshwater (crayfish, Orconectes virilis) vs two osmoconforming marine invertebrates (lobster, Homarus americanus; scallop, Argopecten concentricus). Intracellular pH significantly decreased after stimulation in the lobster tail muscle, but not in the crayfish tail or scallop phasic adductor muscles. The decrease in phosphoarginine‐to‐ATP ratio after stimulation was similar in the three muscles. Muscle T2 increased from 37 to 43 ms (p < 0.02, n = 7) after stimulation in crayfish, but was unchanged in lobster muscle (32 ms, n = 7), and significantly decreased (from 40 to 36 ms, p < 0.02, n = 11) in scallop muscle. The observation that T2 does not increase after stimulation in muscles of marine invertebrates with high natural osmolarity is consistent with the hypothesis that the T2 increase in mammalian muscle is related to osmotically driven shifts of fluid between subcellular compartments. Copyright © 2001 John Wiley & Sons, Ltd.

Abbreviations used:

PArg

phosphoarginine

Pi

inorganic phosphate
Using Frame Relay for a VPN
Authors: Mangan Tim
Published: August 2002

Frame Relay and ATM networks have been the standard for VPN networking for the last decade. More recently, IP‐based VPNs have become possible. This article discusses the key reasons for selecting each. Copyright © 2001 John Wiley & Sons, Ltd.
Homogeneous sets and domination: A linear time algorithm for distance—hereditary graphs
Authors: Nicolai Falk , Szymczak Thomas
Published: August 2002

In this paper, we consider the r‐dominating set problem on graphs which can be generated from the one‐vertex graph by a finite number of homogeneous extensions and by attaching pendant vertices. We show that for such graphs a minimum cardinality r‐dominating set can be computed in O(|V| |E|) time; for distance—hereditary graphs—a proper subclass—we even get a linear time algorithm. Furthermore, since these graph classes are closed under adding false twins, a total dominating set can be computed in the same time bound. © 2001 John Wiley & Sons, Inc.
Maximizing residual flow under an arc destruction
Authors: Aneja Y. P. , Chandrasekaran R. , Nair K. P. K.
Published: August 2002

In this paper, we consider two problems related to single‐commodity flows on a directed network. In the first problem, for a given s – t flow, if an arc is destroyed, all the flow that is passing through that arc is destroyed. What is left flowing from s to t is the residual flow. The objective is to determine a flow pattern such that the residual flow is maximized. We provide a strongly polynomial algorithm for this problem, called the maximum residual flow problem, and consider various extensions of this basic model. In the second problem, known as the “most vital arc” problem, the objective is to remove an arc so that the maximal flow on the residual network is as small as possible. Results are also derived which help implement an efficient scheme for solving this problem. © 2001 John Wiley & Sons, Inc.
Exact algorithms for minimum routing cost trees
Authors: Fischetti Matteo , Lancia Giuseppe , Serafini Paolo
Published: August 2002

Given a set of points and distances between them, a basic problem in network design calls for selecting a graph connecting them at a minimum total routing cost, that is, the sum over all pairs of points of the length of their shortest path in the graph. In this paper, we describe some branch‐and‐bound algorithms for the exact solution of a relevant special case arising when the graph has to be a tree. One of the enhancements to our algorithms is the use of “LP shortcutting,” which we introduce as a general‐purpose technique for speeding up the search. Besides network design, we show how trees of small routing cost find useful application in computational biology, where they can be used to determine good alignments of genomic sequences. This leads to a novel alignment heuristic that we analyze in our computational section. © 2002 Wiley Periodicals, Inc.
Cellular interactions in the development of the olfactory system: An ablation and homotypic transplantation analysis
Authors: Wang Xiao‐jun , Gao Chen , Norgren Robert B.
Published: August 2002

In the current study, we addressed two questions: First, is the olfactory placode necessary for the development of the olfactory bulb and the entire telencephalon? Second, does the olfactory placode contribute cells to the olfactory bulb? We addressed these questions by unilaterally ablating the olfactory placode in chick embryos before an olfactory nerve was produced and, in a second series of experiments, by replacing the ablated chick olfactory placode with a quail olfactory placode. Our results indicate that the olfactory placode is critical for olfactory bulb development, but is not necessary for the development of the rest of the telencephalon. Further, our results support the hypothesis that LHRH neurons and olfactory nerve glia originate in the olfactory placode, but do not support an olfactory placodal origin for other cell types within the olfactory bulb. © 2001 John Wiley & Sons, Inc. J Neurobiol 49: 29–39, 2001
Optical detection of neuromodulatory effects of conditioned taste aversion in the pond snail Lymnaea stagnalis
Authors: Kojima Satoshi , Hosono Tomoko , Fujito Yutaka , Ito Etsuro
Published: August 2002

Multiple site optical recording was used to analyze the neural activity changes caused by conditioned taste aversion (CTA) training in the pond snail Lymnaea stagnalis. In response to electrical stimulation of the median lip nerve, which transmits chemosensory signals of appetitive taste to the central nervous system, we optically detected large numbers of spikes in several parts of the buccal ganglion. The effects of CTA training on the spike responses were examined in two areas of the ganglion where the most active neural responses occurred. In one area (termed Area I) that included the N1 medial (N1M) cells, a class of central pattern generator interneurons involved in feeding behavior, the number of spikes in a period 1500–2000 ms after median lip nerve stimulation was significantly reduced in conditioned animals compared to control animals. In another area (termed Area II) positioned between buccal motoneurons, the B3 and B4CL (cluster) cells, the evoked spike responses were unaffected by CTA training. These results, taken together with our previous results indicating an enhancement of an inhibitory input to the N1M cells during CTA, suggest that an appetitive taste signal transmitted to the N1M cells through the median lip nerves is suppressed during CTA, resulting in a decrease of the feeding response. © 2001 John Wiley & Sons, Inc. J Neurobiol 49: 118–128, 2001
A stabilized finite element formulation for the transonic small‐disturbance system
Authors: Giddings Thomas E. , Fish Jacob , Rusak Zvi
Published: August 2002

A stabilized finite element formulation for the transonic small‐disturbance system of equations is developed and used to solve a variety of problems in transonic aerodynamics. An adaptive mesh refinement technique and a common discontinuity capturing operator are used to resolve regions with large gradients in the velocity field. The scheme works well in both flow regimes, subsonic and supersonic, and captures shocks naturally. Agreement with available experimental observations and theoretical approximations is very good. Copyright © 2001 John Wiley & Sons, Ltd.
Low‐Reynolds‐number flow around an oscillating circular cylinder using a cell viscousboundary element method
Authors: Uzunoğlu B. , Tan M. , Price W. G.
Published: August 2002

Flow fields from transversely oscillating circular cylinders in water at rest are studied by numerical solutions of the two‐dimensional unsteady incompressible Navier–Stokes equations adopting a primitive‐variable formulation. These findings are successfully compared with experimental observations. The cell viscous boundary element scheme developed is first validated to examine convergence of solution and the influence of discretization within the numerical scheme of study before the comparisons are undertaken. A hybrid approach utilising boundary element and finite element methods is adopted in the cell viscous boundary element method. That is, cell equations are generated using the principles of a boundary element method with global equations derived following the procedures of finite element methods. The influence of key parameters, i.e. Reynolds number Re, Keulegan–Carpenter number KC and Stokes' number β, on overall flow characteristics and vortex shedding mechanisms are investigated through comparisons with experimental findings and theoretical predictions. The latter extends the study into assessment of the values of the drag coefficient, added mass or inertia coefficient with key parameters and the variation of lift and in‐line force results with time derived from the Morison's equation. The cell viscous boundary element method as described herein is shown to produce solutions which agree very favourably with experimental observations, measurements and other theoretical findings. Copyright © 2001 John Wiley & Sons, Ltd.
The generation of hexahedral meshes for assembly geometry: survey and progress
Authors: Tautges Timothy J.
Published: August 2002

The finite element method is being used today to model component assemblies in a wide variety of application areas, including structural mechanics, fluid simulations, and others. Generating hexahedral meshes for these assemblies usually requires the use of geometry decomposition, with different meshing algorithms applied to different regions. While the primary motivation for this approach remains the lack of an automatic, reliable all‐hexahedral meshing algorithm, requirements in mesh quality and mesh configuration for typical analyses are also factors. For these reasons, this approach is also sometimes required when producing other types of unstructured meshes. This paper will review progress to date in automating many parts of the hex meshing process, which has halved the time to produce all‐hex meshes for large assemblies. Particular issues which have been exposed due to this progress will also be discussed, along with their applicability to the general unstructured meshing problem. Published in 2001 by John Wiley & Sons, Ltd.
A coupled BEM and arbitrary Lagrangian–Eulerian FEM model for the solution of two‐dimensional laminar flows in external flow fields
Authors: Young D. L. , Chang J. T. , Eldho T. I.
Published: August 2002

This paper describes a new computational model developed to solve two‐dimensional incompressible viscous flow problems in external flow fields. The model based on the Navier–Stokes equations in primitive variables is able to solve the infinite boundary value problems by extracting the boundary effects on a specified finite computational domain, using the pressure projection method. The external flow field is simulated using the boundary element method by solving a pressure Poisson equation that assumes the pressure as zero at the infinite boundary. The momentum equation of the flow motion is solved using the three‐step finite element method. The arbitrary Lagrangian–Eulerian method is incorporated into the model, to solve the moving boundary problems. The present model is applied to simulate various external flow problems like flow across circular cylinder, acceleration and deceleration of the circular cylinder moving in a still fluid and vibration of the circular cylinder induced by the vortex shedding. The simulation results are found to be very reasonable and satisfactory. Copyright © 2001 John Wiley & Sons, Ltd.
Locking in the incompressible limit for the element‐free Galerkin method
Authors: Huerta Antonio , Fernández‐Méndez Sonia
Published: August 2002

Volumetric locking (locking in the incompressible limit) for linear elastic isotropic materials is studied in the context of the element‐free Galerkin method. The modal analysis developed here shows that the number of non‐physical locking modes is independent of the dilation parameter (support of the interpolation functions). Thus increasing the dilation parameter does not suppress locking. Nevertheless, an increase in the dilation parameter does reduce the energy associated with the non‐physical locking modes; thus, in part, it alleviates the locking phenomena. This is shown for linear and quadratic orders of consistency. Moreover, the biquadratic order of consistency, as in finite elements, improves the locking behaviour. Although more locking modes are present in the element‐free Galerkin method with quadratic consistency than with standard biquadratic finite elements. Finally, numerical examples are shown to validate the modal analysis. In particular, the conclusions of the modal analysis are also confirmed in an elastoplastic example. Copyright © 2001 John Wiley & Sons, Ltd.
Frame‐indifferent beam finite elements based upon the geometrically exact beam theory
Authors: Betsch P. , Steinmann P.
Published: August 2002

This paper describes a new beam finite element formulation based upon the geometrically exact beam theory. In contrast to many previously proposed beam finite element formulations the present discretization approach retains the frame‐indifference (or objectivity) of the underlying beam theory. The space interpolation of rotational degrees‐of‐freedom is circumvented by the introduction of a reparameterization of the weak form corresponding to the equations of motion of the geometrically exact beam theory. Copyright © 2002 John Wiley & Sons, Ltd.
Murine dopamine transporter proximal promoter sequences do not direct lacZ transgene expression to ventral midbrain
Authors: Donovan David M. , Nguyen John , Revay Randall , Liu Zi‐yao , Rowley Daniel L. , Barrett Tanya
Published: August 2002

Dopamine is an important neurotransmitter involved in a variety of central nervous system functions including locomotion, cognition and emotions. The dopamine transporter is uniquely expressed on dopamine neurons, where it's uptake of dopamine constitutes the primary mechanism for terminating dopamine neurotransmission. Although dopamine transporter (DAT1) sequences have been isolated from several organisms, little is known about the genomic regulatory elements required for expression. This work describes transgenic analysis of a series of murine DAT1 promoter fusions to the lacZ reporter gene to localize putative promoter elements. Despite lacZ expression from these constructs in cultured cells, no expression was observed in any dopaminergic loci from either adult or embryonic mouse brains, for any of the four constructs described. Thus, the murine DAT gene sequences sufficient for activating expression are not located within 2.8 kb 5 to the transcription start site, or within the first eight kb of transcribed sequences.
Mitochondrial protecting agents inhibit t‐butylhydro‐peroxide‐induced and caspase‐mediated neuronal death in cultured cerebellar neurons
Authors: Ouyang Yi‐Bing , Zhang Xiao‐Hu , Liu Chun‐Li , Csiszar Katalin , Li Ping‐An , Hu Bing‐Ren
Published: August 2002

Mitochondrial release of cytochrome c and activation of caspases are considered to be parts of a major cell death pathway in cells of various origins. In order to study if caspases are involved in the events leading to cell death induced by oxidants we exposed cerebellar granule cells to tert‐butylhydroperoxide (t‐BuOOH). The cultured cells were treated with various concentrations of t‐BuOOH for 30 min, then washed with normal cell culture medium and allowed to recover for 3 h in the normal medium before the analyses were performed. Neuronal viability was assessed. The results showed that t‐BuOOH caused neuronal death in a dose‐dependent manner. Double‐staining confocal microscopy with antibodies against active forms of caspase‐3 or caspase‐7 and propidium iodide demonstrated that both caspase‐3 and caspase‐7 were markedly activated in cultured neurons after t‐BuOOH treatment. The activation of caspase‐3 and caspase‐7 was confirmed by Western blot analysis. The mitochondrial protecting agents cyclosporin A (CsA) and ursodeoxycholic acid (UDCA) and the free radical scavenger alpha‐phenyl‐N‐tert‐butyl nitrone (PBN) protected cerebellar granule cells against t‐BuOOH induced neuronal death and inhibited the activation of caspases. These data provide evidence that cultured cerebellar granule cells, when exposed to an oxidant such as t‐BuOOH, undergo cell death by activation of caspases. Furthermore, compounds that protect mitochondria or act as free radical scavengers may salvage the cells by blocking the death process.
The role of interleukin‐6 (IL‐6) in the proliferation and differentiation of human neural stem cells
Authors: Pagano Stefano F. , Lucchiari Sabrina , Bez Alessandra , Ponti Dario , Onofrj Marco , Vitello Francesco , Torrente Yvan , Etteri Sabrina , Di Giorgi Valeria , Colombo Augusto , Bresolin Nereo , Girelli Marina , Cova Lidia , Parati Eugenio A.
Published: August 2002

The proliferation of human embryonic and adult stem cells is controlled by extrinsic factors such as epidermal growth factor (EGF) and fibroblast growth factor (bFGF). Their differentiation, instead, is clearly determined by a family of neuropoietic factors including ciliary neurotrophic factor (CNTF), leukaemia inhibitory factor (LIF) and interleukin‐6 (IL‐6). The results of this study show the capability of the interleukin‐6 to delay the differentiation processes and to improve significantly the proliferation condition of embryonic neural stem cells. Besides, clonal analysis shows that the self‐renewing capacity and the multipotentiality of human embryonic neural stem cells are not modified by the presence of IL‐6 during early and later culture passages. This is an important demonstration of the high clonogenic potential of IL‐6 in human embryonic neural stem cells (heCNS‐SC), whose capacity to secrete IL‐6 we have, finally, demonstrated.
Analysis of a block red‐black preconditioner applied to the Hermite collocation discretization of a model parabolic equation
Authors: Brill Stephen H. , Pinder George F.
Published: August 2002

We are concerned with the numerical solution of a model parabolic partial differential equation (PDE) in two spatial dimensions, discretized by Hermite collocation. In order to efficiently solve the resulting systems of linear algebraic equations, we choose the Bi‐CGSTAB method of van der Vorst (1992) with block Red‐Black Gauss‐Seidel (RBGS) preconditioner. In this article, we give analytic formulae for the eigenvalues that control the rate at which Bi‐CGSTAB/RBGS converges. These formulae, which depend on the location of the collocation points, can be utilized to determine where the collocation points should be placed in order to make the Bi‐CGSTAB/RBGS method converge as quickly as possible. Along these lines, we discuss issues of choice of time‐step size in the context of rapid convergence. A complete stability analysis is also included. © 2001 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 17:584–606, 2001
Numerical solution of the three‐dimensional parabolic equation with an integral condition
Authors: Dehghan Mehdi
Published: August 2002

Developement of numerical methods for obtaining approximate solutions to the three dimensional diffusion equation with an integral condition will be carried out. The numerical techniques discussed are based on the fully explicit (1,7) finite difference technique and the fully implicit (7,1) finite difference method and the (7,7) Crank‐Nicolson type finite difference formula. The new developed methods are tested on a problem. Truncation error analysis and numerical examples are used to illustrate the accuracy of the new algorithms. The results of numerical testing show that the numerical methods based on the finite difference techniques discussed in the present article produce good results. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 193–202, 2002; DOI 10.1002/num.1040
The Internet and NGO–government relations: injecting chaos into order
Authors: Brainard Lori A. , Siplon Patricia D.
Published: August 2002

In recent years, theory building on NGO–government relations has proliferated, but it has not accounted for changes in communications technology or for the quantitative and qualitative expansion of the NGO sector. In this article we look at relations between and among government and disease‐ and disorder‐based NGOs. We draw on cases in which we study relations between traditional NGOs and new, more radical and more exclusively Internet‐based health advocacy groups. We argue that, contrary to investigating NGO–government relations in isolation, our theories must account for antecedent variables including NGO delivery of benefits to members and supporters (including informational, purposive and solidary benefits) and the motivations for organizing. After summarizing how different kinds of health advocacy organizations use the Internet to organize and provide benefits to members and supporters, we show that these variables have important implications not only for the relations between NGOs, but between NGOs and government. Specifically, we conclude that theories that distinguish between ‘cooperation’ and ‘co‐optation’ in NGO–government relations may need to be adjusted to reflect the realities as they are perceived by NGOs. Copyright © 2002 John Wiley & Sons, Ltd.
Affirmative action, duality of error, and the consequences of mispredicting the academic performance of african american college applicants
Authors: Mumpower Jeryl L. , Nath Radhika , Stewart Thomas R.
Published: August 2002

The implications of different potential affirmative action policies depend on three factors: selection rate
from the applicant pool, base rate of qualified applicants, and accuracy of performance predictions. A series of
analyses was conducted under various assumptions concerning affirmative action plans, causes of racial
differences in average college admissions test scores, and racial differences in accuracy of performance
predictions. Evidence suggesting a lower level of predictive accuracy for African Americans implies that, under
a program of affirmative action, both proportionately more false positives (matriculated students who do
not succeed) and proportionately more false negatives (rejected applicants who could have
succeeded) will be found among African American applicants. Unless equivalent levels of predictive accuracy
are achieved for both groups, no admission policy can be fair simultaneously to majority group applicants and
African American applicants. © 2002 by the Association for Public Policy Analysis and Management.
Focused microwave‐assisted extraction of cocaine and benzoylecgonine from coca leaves
Authors: Brachet A. , Christen P. , Veuthey J.‐L.
Published: August 2002

Extraction of cocaine and benzoylecgonine from coca leaves was performed by focused microwave‐assisted extraction (FMAE). Cocaine extraction was optimised with respect to the nature of the extracting solvent, the particle size distribution, the moisture of the sample, the applied microwave power and the radiation time. A central composite design was used to optimise the two latter parameters and to assess the robustness of the extraction method around the best conditions. FMAE generated extracts similar to those obtained by conventional solid–liquid extraction but in a more efficient manner, i.e. 30 s were sufficient to extract cocaine quantitatively from leaves. Analyses of cocaine and benzoylecgonine in coca leaves was carried out by capillary GC‐FID and GC‐MS for peak identification, as well as by capillary electrophoresis with UV detection. Copyright © 2002 John Wiley & Sons, Ltd.
Carbamoyl phosphate synthetase I deficiency: molecular genetic findings and prenatal diagnosis
Authors: Aoshima Tsutomu , Kajita Mitsuharu , Sekido Yoshitaka , Mimura Shunji , Itakura Atsuo , Yasuda Izumi , Saheki Takeyori , Watanabe Kazuyoshi , Shimokata Kaoru , Niwa Toshimitsu
Published: August 2002

We report a Japanese boy who died at Day 28 of life because of severe carbamoyl phosphate synthetase I (CPS1) deficiency that was proven by enzyme assay. By analysis of cDNA and genomic DNA, he was shown to be a compound heterozygote with two point mutations of the CPS1 gene, 840G>C leading to an aberrant splicing and 1123C>T (predicting Q375X). The 840G>C was a mutation described in another Japanese family. Since his parents carried each mutation heterozygously, we performed prenatal diagnosis at 16 weeks of his mother's next gestation by multiplex PCR and melting curve analysis in a single capillary containing two‐color fluorescent (LC‐Red 640 and LC‐Red 705) probes on LightCycler. We analyzed genomic DNA extracted from amniotic cells and found that the fetus was homozygous for the wild‐type alleles. At term a healthy girl was born without hyperammonemia. Copyright © 2001 John Wiley & Sons, Ltd.
Deletion 15q24‐26 in prenatally detected diaphragmatic hernia: increasing evidence of a candidate region for diaphragmatic development
Authors: Schlembach D. , Zenker M. , Trautmann U. , Ulmer R. , Beinder E.
Published: August 2002

Survival of children with congenital diaphragmatic hernia (CDH) is mainly dependent on the extent of lung hypoplasia and the presence of additional congenital anomalies or chromosomal aberrations. A chromosomal deletion 15q25‐q26.2 in a fetus with prenatally diagnosed CDH and growth retardation is reported. Despite optimal pre‐ and neonatal management the baby died shortly after birth. There is increasing evidence that the long arm of chromosome 15, and especially the region 15q24 to 15q26, plays a crucial role in the development of the diaphragm. The finding of a deletion within 15q24‐26 in a fetus with CDH has to be considered a predictor of poor prognosis. It is of utmost interest for proper parental counselling to search in fetuses with CDH for subtle chromosomal lesions paying special attention to chromosome 15q. Copyright © 2001 John Wiley & Sons, Ltd.
Attaining UKPDS management targets in type 2 diabetes: failures and difficulties
Authors: Woodward A. , Groves T. , Wallymahamed M. , Wilding J.P. , Gill G.V.
Published: August 2002

The UKPDS highlighted the importance of good blood glucose control and tight blood pressure control in patients with type 2 diabetes. We have audited 500 consecutive clinic records from patients with type 2 diabetes attending consultant clinics (hospital) and data from a district diabetic register of 500 type 2 patients attending general practice (community) to determine whether internationally agreed targets of good blood glucose (HbA1c<7%, using a 'DCCT‐aligned' method) and tight blood pressure (BP) control (BP<140/85) are achieved in patients with type 2 diabetes. The mean HbA1c was 8.7±1.8 (SD)% (hospital) and 8.2±1.5% (community); 81% (hospital) and 72% (community) patients with a recorded measurement in the last twelve months had an HbA1c level>7%; 58% (hospital) and 44% (community) patients had levels>8%. The mean systolic blood pressure (SBP) was 151±25 mmHg (hospital) and 151±20 mmHg (community); the mean diastolic blood pressure (DPB) was 77±13mmHg (hospital) and 83±11mmHg (community), 68% (hospital) and 66% (community) had at least one measurement above 140/85, of which 45% (hospital) and 49% (community) patients were not prescribed any anti‐hypertensive medication. Guideline targets, particularly with regard to glycaemic and blood pressure control are not achieved in a high proportion of diabetic patients. The problem is similar in both hospital and community‐based care; in many patients, simple adjustments of medication may be all that is required to achieve better control of BP and glucose. However, it is recognised that this will be more difficult in some patients, and may require increased investment in personnel and an increase in prescribing costs. Copyright © 2001 John Wiley & Sons, Ltd.
Replicable types and subtypes of personality: German NEO‐PI‐R versus NEO‐FFI
Authors: Schnabel Konrad , Asendorpf Jens B. , Ostendorf Fritz
Published: August 2002

In two German samples we investigated whether three major personality prototypes (resilient, overcontrolled, and undercontrolled) can be replicated across different Big Five instruments (NEO‐FFI and NEO‐PI‐R), and whether they can be differentiated into replicable subtypes. For prototypes and subtypes, replicability within and consistency across samples was quantitatively measured. Three replicable prototypes were confirmed, but only two replicable resilient subtypes (well adjusted and assertive) were found. It is concluded that the search for a hierarchical taxonomy of people will require more investigation. Copyright © 2002 John Wiley & Sons, Ltd.
The replicability and utility of three personality types
Authors: Costa Paul T. , Herbst Jeffrey H. , McCrae Robert R. , Samuels Jack , Ozer Daniel J.
Published: August 2002

Personality types are construed as constellations of features that uniquely define discrete groups of individuals. Types are conceptually convenient because they summarize many traits in a single label, but until recently most researchers agreed that there was little evidence for the existence of discrete personality types. Several groups of researchers have now proposed replicable, empirical person clusters based on measures of the Five‐Factor Model. We consider several methodological artifacts that might be responsible for these types, and conclude that these artifacts may contribute to the replicability of types, but cannot entirely account for it. The present research attempts to replicate these types in four large and diverse adult samples: the Baltimore Longitudinal Study of Aging (N = 1856); the East Baltimore Epidemiologic Catchment Area study (N = 486); the University of North Carolina Alumni Heart Study (N = 2420); and an HIV risk reduction intervention study (N = 274). A clear replication (kappa = 0.60) of the proposed types was found in only one sample by one standard of comparison. The failure of the three personality types to replicate in three of the four samples leads to the conclusion that they are not robust empirical entities. Type membership predicted psychosocial functioning and ego resiliency and control, but only because it summarized trait standing; dimensional trait measures were consistently better predictors. Nevertheless, while the types do not refer to distinct, homogeneous classes of persons, they do have utility as convenient labels summarizing combinations of traits that relate to important outcomes. Published in 2002 by John Wiley & Sons, Ltd.
Evaluating cluster analysis solutions: an application to the Italian NEO personality inventory
Authors: Barbaranelli Claudio
Published: August 2002

This paper is concerned with the evaluation of cluster analysis solutions. Internal criteria and replication issues are compared and applied to empirical data collected from an Italian sample of 421 young adults, using the NEO Personality Inventory. The following internal criteria were considered: C, gamma, and G( + ) indices, and point‐biserial correlation. Replication was examined (i) ‘internally’ using double cross‐validation and bootstrap approaches and (ii) ‘externally’ by comparing the solution obtained on the Italian sample with the results obtained in German and Spanish samples. While replication analyses supported three‐ and four‐cluster solutions, internal criteria (with the exception of point‐biserial correlation) tended to privilege solutions with a much larger number of groups. Advantages and limitations of the different strategies are discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Structure and characterization of poly[(vinylidene fluoride)‐co‐hexafluoropropene]–(dibutyl phthalate) blends
Authors: Marigo Antonio , Marega Carla , Bassi Mattia , Fumagalli Massimiliano , Sanguineti Aldo
Published: August 2002

Blends of poly[(vinylidene fluoride)‐co‐hexafluoropropene] with dibutyl phthalate were examined by wide‐ and small‐angle X‐ray scattering, differential scanning calorimetry and dynamic mechanical spectroscopy, in order to study the influence of amount of plasticizer and the crystallization rate on the crystallinity and lamellar morphology of the copolymer.

The dibutyl phthalate seems, at least for the cooling and heating rates used, simply to dilute the crystalline phase without affecting the amount of polymer that is able to crystallize. Furthermore, the small‐angle X‐ray scattering technique points out that the plasticizer mostly enters the amorphous phase either outside or inside the lamellar stacks.

© 2001 Society of Chemical Industry
Water uptake effects in resins based on alkenyl‐modified cyanate ester–bismaleimide blends
Authors: Hamerton I , Herman H , Rees K T , Chaplin A , Shaw S J
Published: August 2002

The analysis of cured resin blends comprising a commercial dicyanate, bismaleimide and a range of novel alkenyl‐substituted cyanates, to determine the chemical effects of long‐term exposure to water, is reported. The cured resin blends underwent accelerated water uptake by immersion at temperatures of 50 °C and 70 °C, for a period of 14–17 months. The presence of about 10–15% (by weight) of alkenyl‐substituted cyanate in the blend leads to a marked reduction in moisture absorption in comparison with the unmodified bismaleimide/cyanate blend containing a comparable amount of bismaleimide. All samples display non‐Fickian diffusion behaviour at both immersion temperatures, although this is most marked at the higher temperature. Thermogravimetric analysis was performed on alkenyl‐modified neat resin samples before and after the immersion period. The modified samples display thermal stabilities that are indistinguishable from cured resins that have not undergone immersion. Spectroscopy (near infrared Raman and mid‐infrared attenuated total reflectance) was performed on cured resin plaques to determine the sample composition as a function of modifier content. The elemental composition of the samples was also determined before and after the immersion period, and no significant variation in elemental composition was recorded for the modified samples.

© British Crown Copyright 2001/DERA. Reproduced with the permission of Her Majesty's Stationery Office. Published for the SCI by John Wiley & Sons, Ltd.
Dielectric relaxation spectroscopy of poly(ethylene terephthalate)
Authors: Pratt Graeme J , Smith Michael J A
Published: August 2002

Contour maps of dielectric loss tangent within the ranges 0.1 Hz to 3 MHz and −175 °C to +190 °C are presented for a commercial poly(ethylene terephthalate) (PET) in two initial states of crystallinity. Individual absorption regions resemble those for poly(butylene terephthalate) and are attributed to carbonyl‐driven α‐ and β‐relaxation processes and to Maxwell–Wagner–Sillars polarizations. Possible causes are considered for the asymmetry and structure apparent in the α‐peak of partially crystalline PET.

© 2001 Society of Chemical Industry
2‐Hydroxyethylmethacrylate carrying uniform porous particles: preparation and electron microscopy
Authors: Tuncel A , Tuncel M , Cicek H , Fidanboy O
Published: August 2002

Uniform macroporous particles carrying hydroxyl groups have been obtained in the size range 3–11.5 µm by seeded polymerization. For this purpose, uniform polystyrene particles in the size range 1.9–6.2 µm were used as seeds. The seed particles were successively swollen by dibutyl phthalate (DBP) and a monomer mixture comprising styrene, 2‐hydroxyethylmethacrylate (HEMA) and a crosslinker. Two different crosslinkers, divinylbenzene (DVB) and ethylene glycol dimethacrylate (EGDMA), were tested. Size distribution properties together with bulk and surface structures of the particles have been characterized by both scanning and transmission electron microscopy. While EGDMA provides uniform particles with a non‐porous surface, DVB produces uniform particles having a highly porous surface and interior. The comparison of FTIR and FTIR‐DRS spectra shows that the HEMA concentration is higher on the particle surface than within the particle interior. Seed latex size and monomer/seed latex ratios are identified as the most important variables affecting the final particles. Different seed latexes have been tried; the result is that highly macroporous particles with a sponge‐like pore structure both on the surface and in the particle interior have been obtained by use of the seed latex with the largest particles and the lowest molecular weight. An increase in the HEMA feed concentration leads to final particles with a non‐porous surface and a crater‐like porosity in the particle interior. The average pore size significantly decreases with increasing DBP/seed latex and monomer/seed latex ratios.

© 2001 Society of Chemical Industry
DSC curing study of catalytically synthesized maleic‐acid‐based unsaturated polyesters
Authors: Simitzis J , Zoumpoulakis L , Soulis S
Published: August 2002

Unsaturated polyesters were synthesized based on ethylene glycol and maleic acid as unsaturated dicarboxylic acid, using a variety of saturated acids in the initial acid mixture, without or with different catalysts. The curing of the polyesters produced with styrene was studied using differential scanning calorimetry (DSC) under dynamic‐ and isothermal‐heating conditions. The FTIR spectra of the initial polyesters and cured polyesters were also determined. Curing is not complete at the end of DSC scan and the unreacted bonds were quantitatively determined from the FTIR spectra and by estimation based on literature data. The value of the mean degree of conversion (α) of all double bonds (styrene unit and maleate unit) was approximately α = 0.40. Using an appropriate kinetic model for the curing exotherm of polyesters, the activation energy (Ea), the reaction order (x) and the frequency factor (ko) were determined. Because the kinetic parameters (ie Ea, k, x) affect the kinetics in various different ways, the curves of degree of conversion versus time at various isothermal conditions are more useful to compare and characterize the curing of polyesters. The kinetic parameters are mainly influenced by the proportion of maleic acid in the polyesterification reaction mixture and secondarily by the residual polyesterification catalyst. The degree of conversion of already crosslinked polyesters is greatly increased by post‐curing them at elevated temperature and for a prolonged time.

© 2002 Society of Chemical Industry