bluuebunny/crossref_metadata_2025 huggingface dataset:
Resting regional cerebral glucose metabolism in advanced Parkinson's disease studied in the off and on conditions with [18F]FDG‐PET
Authors: Berding Georg , Odin Per , Brooks David J. , Nikkhah Guido , Matthies Cordula , Peschel Thomas , Shing Mona , Kolbe Hans , van den Hoff Jörg , Fricke Harald , Dengler Reinhard , Samii Madjid , Knapp Wolfram H.
Published: August 2002

Studies of resting regional cerebral glucose consumption (rCMRGlc) in nondemented patients with Parkinson's disease (PD) have produced conflicting results, reporting both reduced and normal metabolism in advanced disease and reduced or normal metabolism after dopaminergic therapy. To investigate these issues, [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) was performed in 11 nondemented PD patients with advanced disease and 10 age‐matched controls. PD patients were studied after withdrawal of all dopaminergic medication to produce a practically defined off condition, and a second time 1 hour after levodopa, resulting in a clinical on state. Dynamic PET scans and simultaneous arterialised venous blood samples of [18F] acticvity were obtained. A graphical approach was used to generate parametric images of rCMRGlc and statistical parametric mapping to localise significant metabolic changes in PD. Compared with controls, global rCMRGlc was reduced in the on but not in the off condition in PD. In both states, significant regional reductions of glucose uptake were found in the parietal, frontal, temporal cortex, and caudate nucleus. Reductions correlated with the severity of disability in frontal and temporal cortex. Direct comparison between on and off conditions revealed relatively greater reductions of uptake in the ventral/orbital frontal cortex and the thalamus during on. Results suggest that cortical and caudate hypometabolism are common in advanced PD and that caution is mandatory if [18F]FDG PET is being used to differentiate advanced PD from dementia and progressive supranuclear palsy where similar reductions are seen. Furthermore, in PD, administration of levodopa is associated with further hypometabolism in orbitofrontal cortex; an area known to be relevant for reversal learning where performance is typically impaired after dopaminergic treatment. © 2001 Movement Disorder Society.
A new time‐domain method based on the general transmission‐line equations
Authors: Zhong Xiaolong , Liu Yaowu , Mei Kenneth K.
Published: August 2002

General transmission‐line equations that can describe both uniform and nonuniform transmission line are derived in brief. By using the algorithm analogous with a one‐dimensional FDTD in the time domain, we obtain a new time‐domain method we call the on‐line FDTD method. Frequency‐domain results are compared with those computed by the MoM to show the validity of our new method. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 46–51, 2002.
Superresolution ISAR imaging using 2‐D autoregressive lattice filters
Authors: Erer Işin , Kayran Ahmet Hamdi
Published: August 2002

A new efficient algorithm to obtain high‐resolution ISAR images in the case of limited frequency band and small angular section is presented. The method is based on the two‐dimensional (2‐D) autoregressive modeling of 2‐D Cartesian frequency backscattered data using 2‐D orthogonal lattice filters. ISAR images obtained for an experimental target are included to validate this technique. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 81–85, 2002.
Wideband LNA design by parallel FETs
Authors: Benvenuti Dario , Cicolani Maurizio , Pisa Stefano , Tommasino Pasquale , Trifiletti Alessandro
Published: August 2002

A new technique to design wideband low‐noise amplifiers (WBLNAs) by using parallel FETs is proposed. In particular, this technique permits us to simplify the tradeoff between the gain and noise figure over wide bands. The feasibility of the suggested technique has been verified by designing and fabricating a WBLNA with three parallel FETs. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 280–284, 2002.
Coplanar waveguide‐fed folded inverted‐F antenna for UMTS application
Authors: Kuo Yen‐Liang , Wong Kin‐Lu
Published: August 2002

A folded inverted‐F strip antenna printed on a dielectric substrate and fed by a coplanar waveguide is presented. A prototype with a small area of 25×8 mm2having a 10 dB impedance bandwidth of about 20% centered at about 2.0 GHz has been constructed and studied. The constructed prototype also showed good radiation characteristics, and is suitable for UMTS (Universal Mobile Telecommunication System, 1920–2170 MHz) applications. The experimental results of the constructed prototype are presented, and are also compared with those of a corresponding simple inverted‐F strip antenna. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 364–366, 2002.
Small printed integrated inverted‐F antenna for Bluetooth application
Authors: Ali Mohammod , Hayes Gerard J.
Published: August 2002

A printed integrated inverted‐F antenna is introduced which operates in the Bluetooth frequency band (2.4–2.485 GHz). The proposed antenna is a part of the radio frequency printed circuit board (PCB) of a cellular telephone or a personal digital assistant (PDA). The antenna being an integral part of the PCB reduces the cost and complexity of designing and manufacturing a separate antenna. The maximum dimension of the antenna on standard FR4 substrate is 25 × 5 × 1 mm3. The antenna operates within 2:1 voltage standing wave ratio (VSWR) and has a free‐space peak gain of 1.5 dBi. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 347–349, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10317
Photonic and relativistic approaches on the speed of microwave propagation
Authors: Ishii T. Koryu
Published: August 2002

Analytical approaches based on theories of relativity and photons are presented. The relativistic approach does not permit the speed of propagation to become superluminal. The classical photon theory is limited to the TEM mode monochromatic CW electromagnetic waves only. The Maxwellian photonic approach permits the speed to become superluminal. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 379–382, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10328
Study of spiral inductors using Cu/low‐kinterconnect for high‐performance radio‐frequency integrated circuit (RF‐IC) applications
Authors: Lin Yo‐Sheng , Hsu Hum‐Ming
Published: August 2002

Spiral inductors with various turn numbers fabricated with the use of leading‐edge 0.13‐μm mixed‐signal/RF CMOS technology with 193‐nm lithography and Cu/low‐k interconnect are described in this article. It is shown that quality (Q) factor decreased and increased with increasing temperature at low frequency and high frequency, respectively. This phenomenon can be explained by the positive temperature coefficients of the metal series resistance (Rs) and the substrate resistance (Rsub). © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 43–48, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10368
A novel H‐shaped patch antenna
Authors: Sheta Abdel Fattah
Published: August 2002

A novel H‐shaped patch antenna suitable for wireless and satellite communications is presented. The new antenna has some advantages compared to conventional microstrip patch antennas, such as small size, a fewer number of modes, no harmonic resonance, and the provision of pure reactive impedances at its harmonics that can result in increasing the transmitter efficiency. The basic principles and design procedure are introduced. Two antennas at two different frequencies, 4 and 10 GHz, are designed, fabricated, and measured. The measured results show a good agreement with the predicted ones. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 62–66, 2001.
Rectangular‐shaped microshield coplanar waveguides on cylindrical substrate
Authors: Karpuz Ceyhun , Görür Adnan , Genç Zülfü
Published: August 2002

In this study, CAD‐oriented analytic expressions derived by the conformal mapping method are presented, for the first time, for calculating the line parameters of a rectangular‐shaped microshield CPW on a cylindrical substrate. The effect of the curvature on the line parameters is discussed. In addition, this paper's results are compared with the results available in the literature for a rectangular‐shaped microshield coplanar waveguide on a planar substrate. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 415–418, 2001.
Ion‐implanted planar‐gate GaAs MESFET optimized for single‐voltage‐supply operation
Authors: Meng C. C. , Chen J. W. , Liu S. J.
Published: August 2002

Ion‐implanted planar‐gate power GaAs MESFETs have been optimized for single‐voltage‐supply operation. Recessed gate MESFETs suffer from variations in pinch‐off voltage. The optimized ion‐implanted planar‐gate power GaAs MESFET has an 80 keV 4.2×1012/cm2Si channel with a 120 keV 1.7×1012/cm2Bep‐buffer. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 44–46, 2001.
Bit‐error‐rate analysis for hybrid PIM–CDMA optical wireless communication systems
Authors: Ghassemlooy Z. , See C. K. , Holding J. M. , Lu C.
Published: August 2002

A hybrid pulse interval modulation–code division multiple access (PIM–CDMA) is proposed. An expression for the bit‐error rate (BER) is given. Numerical results presented are compared with hybrid PPM–CDMA and OOK–CDMA schemes. For a low number of users, PIM–CDMA achieves similar and marginally lower BER performance compared with PPM–CDMA and OOK–CDMA, respectively. For a large number of users, it offers better performance compared with OOK. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 40–44, 2001.
Pilot trial of tumor‐specific peptide vaccination and continuous infusion interleukin‐2 in patients with recurrent Ewing sarcoma and alveolar rhabdomyosarcoma: An inter‐institute NIH study†
Authors: Dagher Ramzi , Long Lauren M. , Read Elizabeth J. , Leitman Susan F. , Carter Charles S. , Tsokos Maria , Goletz Theresa J. , Avila Nilo , Berzofsky Jay A. , Helman Lee J. , Mackall Crystal L.
Published: August 2002

Background

Patients with recurrent Ewing sarcoma and alveolar rhabdomyosarcoma have poor prognoses and limited therapeutic options. We have investigated the use of peptide pulsed vaccination in an attempt to immunologically target the breakpoint region of tumor specific fusion proteins expressed in these tumors.

Procedure

Sixteen patients with recurrent, translocation positive, Ewing sarcoma, and alveolar rhabdomyosarcoma underwent apheresis for collection of peripheral blood mononuclear cells. Following countercurrent centrifugal elutriation, an apheresis product comprised predominantly of monocytes but containing small numbers of circulating immature dendritic cells was pulsed with peptides derived from the breakpoint region of the fusion proteins. Vaccines were administered intravenously concomitant with continuous intravenous rhIL‐2 at 9 × 106 IU/m2/day.

Results

Toxicity was limited to IL‐2 related effects and was generally mild. Following vaccination, all patients showed progressive disease, most in a rapid fashion following the first vaccine. One patient showed evidence of an immunologic response and another showed a mixed clinical response. Patients enrolled on this tumor vaccine trial showed significant immunosuppression and large bulky tumors.

Conclusions

Peptide vaccination as administered in this trial did not alter the dismal clinical outcome for patients with recurrent pediatric sarcomas. Future trials of tumor vaccines in this population should target patient populations with improved immune competence and smaller tumor burdens. Furthermore, optimization of the antigen presenting cell populations may be important for inducing immune responses to peptide antigens. Med Pediatr Oncol 2002;38:158–164. Published 2002 Wiley‐Liss, Inc.
Role of cholesterol in germ‐line development of Caenorhabditis elegans*
Authors: Shim Yhong‐Hee , Chun Ju Hee , Lee Eun‐Young , Paik Young‐Ki
Published: August 2002

We investigated the effects of cholesterol starvation on Caenorhabditis elegans development at both embryonic and post‐embryonic stages by examining brood size, embryonic lethality, growth rate, and worm size. The brood sizes of worms grown without cholesterol were substantially reduced in subsequent generations as compared to the control group with cholesterol: 13, 33, and 39% at the first, the second, and the third generation, respectively. The growth rate was also reduced by 20%–26%. Worms became adults after 120–130 hr incubation at 20°C. Embryonic lethality was detected in the range of 1.6%–2.9% as compared to 0.8% of the control group. The percent development from an embryo to an adult was lowered by an average of 10%. Further analyses of germ line development to understand the reduction of brood size revealed that both germ line proliferation and differentiation were affected, and the most striking effect was seen in oogenesis. Defective oogenesis resulted in endomitotic oocytes (Emo, 22% at F1, 26% at F2, and 30% at F3). Thus, cholesterol appears to be required for all developmental stages of C. elegans. Mol. Reprod. Dev. 61: 358–366, 2002. © 2002 Wiley‐Liss, Inc.
Aneuploid spermatozoa in infertile men: Teratozoospermia
Authors: Templado Cristina , Hoang Tina , Greene Calvin , Rademaker Alfred , Chernos Judy , Martin Renée
Published: August 2002

We and others have demonstrated that infertile men who are candidates for intracytoplasmic sperm injection (ICSI) have an increased frequency of chromosomal abnormalities in their sperm. Reports based on prenatal diagnosis of ICSI pregnancies have confirmed the increased frequency of chromosomal abnormalities in offspring. Most studies to date have lumped various types of infertility together. However, it is quite likely that some subsets of infertility have an increased risk of sperm chromosomal abnormalities whereas others do not. We have studied nine men with severe teratozoospermia (WHO, 1992 criteria, 0–13% morphologically normal forms) by multicolour fluorescence in situ hybridisation (FISH) analysis to determine if they have an increased frequency of disomy for chromosomes 13, 21, XX, YY, and XY, as well as diploidy. All of the men also had aesthenozoospermia (< 50% forward progression) but none of the men had oligozoospermia (<20 × 106 sperm/ml). The patients ranged in age from 20 to 49 years (mean 33.2 years) in comparison to 18 normal control donors who were 23 to 58 years (mean 35.6 years). The control donors had normal semen parameters and no history of infertility. A total of 180,566 sperm were scored in the teratozoospermic men with a minimum of 10,000 sperm analyzed/donor/chromosome probe. There was a significant increase in the frequency of disomy in teratozoospermic men compared to controls for chromosomes 13 (.23 vs. .13%), XX (.13 vs. .05%), and XY (.50 vs. .30%) (P < .0001, 2‐tailed Z statistic). This study indicates that men with teratozoospermia and aesthenozoospermia but with normal concentrations of sperm have a significantly increased frequency of sperm chromosomal abnormalities. Mol. Reprod. Dev. 61: 200–204, 2002. © 2002 Wiley‐Liss, Inc.
Characterization of bleomycin lung injury by nuclear magnetic resonance: Correlation between NMR relaxation times and lung water and collagen content
Authors: Cutillo Antonio G. , Chan Pei H. , Ailion David C. , Watanabe Suetaro , Rao Narayanam V. , Hansen Christopher B. , Albertine Kurt H. , Laicher Gernot , Durney Carl H.
Published: August 2002

The response of the NMR relaxation times (T1, CPMG T2, and Hahn T2) to bleomycin‐induced lung injury was studied in excised, unperfused rat lungs. NMR, histologic, and biochemical (collagen content measurement) analyses were performed 1, 2, 4, and 8 weeks after intratracheal instillation of saline (control lungs) or 10 U/kg bleomycin sulfate. The control lungs showed no important NMR, water content, histologic, or collagen content changes. The spin‐spin relaxation times for the fast and intermediate components of the CPMG decay (T2f and T2i, respectively) increased 1 week after bleomycin injury (acute inflammatory stage) and then progressively decreased during the following 2–8 weeks (i.e., with the development of the chronic, fibrotic stage of the injury). The slow component (T2s) showed no significant changes. The response of T1 and the slow component of the Hahn T2 was, on the whole, similar to that of CPMG T2f and T2i. T1 changes were very small. Lung water content increased 1 week after injury. Histologic and biochemical assessment of collagen showed that collagen content was close to control at 1 week, but markedly increased at 2, 4, and 8 weeks. T1 and T2 data were directly correlated with lung water content and inversely correlated with collagen content. Our results indicate that NMR relaxation time measurements (particularly T2) reflect the structural changes associated with bleomycin injury. The prolonged T2 relaxation times observed in the acute stage are related to the presence of edema, whereas the subsequent decrease in these values marks the stage of the collagen deposition (fibrotic stage). CPMG‐T2 and Hahn‐T2 measurements can be valuable as a potentially noninvasive method for characterizing bleomycin‐induced lung injury and pathologically related lung disorders. Magn Reson Med 47:246–256, 2002. © 2002 Wiley‐Liss, Inc.
Combination of signals from array coils using image‐based estimation of coil sensitivity profiles
Authors: Bydder M. , Larkman D.J. , Hajnal J.V.
Published: August 2002

It is well established that the optimal unbiased way to combine image data from array coils is a pixel‐by‐pixel sum of coil signals, with each signal weighted by the individual coil sensitivity at the location of the pixel. A pragmatic alternative combines the images from the coils as the square root of the sum of squares (SOS), which can reduce the signal‐to‐noise ratio (SNR) and introduce bias. This work describes how to replace coil sensitivity by an image‐derived quantity that enables close to optimal signal combination up to a global intensity scaling. Typical scaling is by an individual coil sensitivity or a linear or SOS combination of the sensitivities of some or all of the coils in the array. The method decreases signal bias, improves SNR when coils have unequal noise levels, and can reduce image artifacts. It can produce phase‐corrected data, which eliminates bias completely. In addition, the method allows images from arrays that include highly localized coils, such as a prostate coil and external pelvic array, to be combined with near‐optimal SNR and an intensity modulation that makes them easier to view. Magn Reson Med 47:539–548, 2002. © 2002 Wiley‐Liss, Inc.
Estimation of respiration‐induced noise fluctuations from undersampled multislice fMRI data†
Authors: Frank Lawrence R. , Buxton Richard B. , Wong Eric C.
Published: August 2002

Functional MRI time series data are known to be contaminated by highly structured noise due to physiological fluctuations. Significant components of this noise are at frequencies greater than those critically sampled in standard multislice imaging protocols and are therefore aliased into the activation spectrum, compromising the estimation of functional activations and the determination of their significance. However, in this work it is demonstrated that unaliased noise information is available in multislice data, and can be used to estimate and reduce noise due to high‐frequency respiratory‐related fluctuations. Magn Reson Med 45:635–644, 2001. Published 2001 Wiley‐Liss, Inc.
Determination of skeletal muscle perfusion using arterial spin labeling NMRI: Validation by comparison with venous occlusion plethysmography
Authors: Raynaud J.S. , Duteil S. , Vaughan J.T. , Hennel F. , Wary C. , Leroy‐Willig A. , Carlier P.G.
Published: August 2002

T1‐based determination of perfusion was performed with the high temporal and spatial resolution that monitoring of exercise physiology requires. As no data were available on the validation of this approach in human muscles, T1‐based NMRI of perfusion was compared to standard strain‐gauge venous occlusion plethysmography performed simultaneously within a 4 T magnet. Two different situations were investigated in 21 healthy young volunteers: 1) a 5‐min ischemia of the leg, or 2) a 2–3 min ischemic exercise consisting of a plantar flexion on an amagnetic ergometer. Leg perfusion was monitored over 5–15 min of the recovery phase, after the air‐cuff arterial occlusion had been released. The interesting features of the sequence were the use of a saturation‐recovery module for the introduction of a T1 modulation and of single‐shot spin echo for imaging. Spatial resolution was 1.7 × 2.0 mm and temporal resolution was 2 s. For data analysis, ROIs were traced on different muscles and perfusion was calculated from the differences in muscle signal intensity in successive images. To allow comparison with the global measurement of perfusion by plethysmography, the T1‐based NMR measurements in exercising muscles were rescaled to the leg cross‐section. The perfusion measurements obtained by plethysmography and NMRI were in close agreement with a correlation coefficient between 0.87 and 0.92. This indicates that pulsed arterial techniques provide determination of muscle perfusion not only with superior spatial and temporal resolution but also with exactitude. Magn Reson Med 46:305–311, 2001. © 2001 Wiley‐Liss, Inc.
Bayesian source separation for reference function determination in fMRI
Authors: Rowe Daniel B.
Published: August 2002

In analyzing fMRI results, identification of significant activation in voxels is a crucial task. A standard method selects a “known” reference function and performs a regression of the time courses on it and a linear trend. Once the linear trend is found, the correlation between the assumed to be known reference function and the detrended observed time‐course in each voxel is computed. But the most important question is: How does one choose the reference function? Here, a Bayesian source separation approach to determining the underlying reference function is described and applied to real fMRI data. This underlying reference function is the unobserved response due to the presentation of the experimental stimulus. Magn Reson Med 46:374–378, 2001. © 2001 Wiley‐Liss, Inc.
Low‐level exposures to organophosphorus esters and peripheral nerve function
Authors: Lotti Marcello
Published: August 2002

This review evaluates the epidemiological and clinical evidence linking low‐level and prolonged exposures to organophosphorus esters, used as insecticides or nerve agents, to peripheral nerve dysfunction. The clinical effects of large doses of these chemicals—including the cholinergic syndrome, the intermediate syndrome, and the delayed polyneuropathy—are all well established and are summarized. Based on these clinical observations and experimental studies, dose–effect relationships indicate that peripheral neuropathy always develops after cholinergic toxicity. However, several studies have suggested that this relationship may be different after low‐level prolonged exposures, as, for instance, those experienced by Gulf War veterans and British sheep farmers, thereby leading to the development of peripheral neuropathy without preceding cholinergic toxicity. A critical assessment of these studies, involving subjects with either current or past exposures, indicates that changes in peripheral nerve function were mild, inconsistent, and unexplained and that most studies lack exposure data. Suggestions made about individual hypersusceptibility to delayed polyneuropathy lack support. It is concluded that there is no evidence of peripheral nerve dysfunction caused by low‐level prolonged exposures to organophosphate insecticides or nerve agents. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
Conduction block in neuralgic amyotrophy
Authors: Watson Bradley V. , Nicolle Michael W. , Brown John D.
Published: August 2002

We describe two cases of neuralgic amyotrophy with electrophysiological evidence of conduction block across the lower trunk of the brachial plexus. Low‐output impedance stimulation of the cervical spinal roots in combination with collision was used to accurately demonstrate the conduction block. Complete electrophysiological recovery of the conduction block occurred within 3 months. Early clinical and electrophysiological recovery in both patients suggests that, in some cases, demyelination may predominate early in the course of neuralgic amyotrophy. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 559–563, 2001
Clinical evaluator reliability for quantitative and manual muscle testing measures of strength in children
Authors: Escolar D. M. , Henricson E. K. , Mayhew J. , Florence J. , Leshner R. , Patel K. M. , Clemens P. R.
Published: August 2002

Measurements of muscle strength in clinical trials of Duchenne muscular dystrophy have relied heavily on manual muscle testing (MMT). The high level of intra‐ and interrater variability of MMT compromises clinical study results. We compared the reliability of 12 clinical evaluators in performing MMT and quantitative muscle testing (QMT) on 12 children with muscular dystrophy. QMT was reliable, with an interclass correlation coefficient (ICC) of >0.9 for biceps and grip strength, and >0.8 for quadriceps strength. Training of both subjects and evaluators was easily accomplished. MMT was not as reliable, and required repeated training of evaluators to bring all groups to an ICC >0.75 for shoulder abduction, elbow and hip flexion, knee extension, and ankle dorsiflexion. We conclude that QMT shows greater reliability and is easier to implement than MMT. Consequently, QMT will be a superior measure of strength for use in pediatric, neuromuscular, multicenter clinical trials. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 787–793, 2001.
An analytical solution for a jointed shield‐driven tunnel lining
Authors: Lee K. M. , Hou X. Y. , Ge X. W. , Tang Y.
Published: August 2002

This paper presents an analytical solution for the prediction of internal forces and displacements of a jointed segmental precast circular tunnel lining. The effects of joint stiffness on the performance of the tunnel lining are discussed. The ‘force method’ is used to determine the internal forces and displacements of jointed tunnel lining. Five shield‐driven tunnel cases are adopted to study the effects of joint stiffness, soil resistance, joint distribution and joint number on the internal forces and displacements of circular tunnels. Laboratory model tests are conducted to verify the proposed analytical solution. Copyright © 2001 John Wiley & Sons, Ltd.
Numerical modelling of the driving response of thin‐walled open‐ended piles
Authors: Liyanapathirana D. S. , Deeks A. J. , Randolph M. F.
Published: August 2002

The driving response of thin‐walled open‐ended piles is studied using numerical simulation of the wave propagation inside the soil plug and the pile. An elastic finite element analysis is carried out to identify the stress wave propagation in the vicinity of the pile toe. It is found that the shear stress wave has the highest magnitude above the bottom of the soil plug. Below the bottom of the soil plug, the vertical stress wave has the highest magnitude. Although the shear stress wave propagating in the radial direction is similar in magnitude to the vertical stress wave at the bottom of the soil plug, it decays rapidly while travelling downwards. The highest vertical stress at the bottom of the soil plug appears after the vertical stress wave interacts with the shear stress wave travelling in the radial direction. Initially, the vertical stress wave propagates with the dilation wave velocity in both the radial and vertical directions. After it interacts with the shear stress wave, the vertical stress wave starts to propagate with the shear wave velocity in the radial direction and with the axial wave velocity downwards. It is concluded that at the bottom of the soil plug, the interaction between the waves travelling in radial and vertical directions is important.

The capabilities of several one‐dimensional pile‐in‐pile models to reproduce the driving response given by a two‐dimensional axisymmetric finite element model is studied. It is seen that when the base of the soil plug fails, a one‐dimensional pile‐in‐pile model can be used to achieve results in agreement with the finite element model. However, when the pile is unplugged, where the base of the soil plug does not fail, a reduced finite element mesh that permits the radial wave propagation inside the soil plug must be used. Copyright © 2001 John Wiley & Sons, Ltd.
Consolidation of double‐layered ground with vertical drains
Authors: Tang Xiao‐Wu , Onitsuka Katsutada
Published: August 2002

Vertical drains are usually installed in subsoil consisting of several layers. Due to the complex nature of the problem, over the past decades, the consolidation properties of multi‐layered ground with vertical drains have been analysed mainly by numerical methods. An analytical solution for consolidation of double‐layered ground with vertical drains under quasi‐equal strain condition is presented in this paper. The main steps for the computation procedure are listed. The convergence of the series solution is discussed. The comparisons between the results obtained by the present analytical method and the existing numerical solutions are described by figures. The orthogonal relation for the system of double‐layered ground with vertical drains is proven. Finally, some consolidation properties of double‐layered ground with vertical drains are analysed. Copyright © 2001 John Wiley & Sons, Ltd.
Effectiveness of two conservative modes of physical therapy in women with urinary stress incontinence
Authors: Arvonen Tiina , Fianu‐Jonasson Aino , Tyni‐Lenné Raija
Published: August 2002

Stress incontinence is the most prevalent form of female urinary incontinence and it affects approximately 5% of younger women to nearly 50% of elderly women. Women have traditionally been treated with pelvic floor muscle exercises alone or with the use of vaginal cones. A new treatment mode, vaginal balls, has been developed. The aim of this study was to compare pelvic floor muscle training with and without vaginal balls and to collect information on women's subjective feelings about the two training modes. The study was carried out as a prospective randomized clinical trial. Thirty‐seven women aged 25–65 were assigned either to a pelvic floor muscle training program or to a training program using weighted vaginal balls for 4 months. Treatment outcomes were assessed by a pad‐test with a standardized bladder volume, vaginal palpation, and by women's self‐reported perceptions. The sense of coherence score was compared with the score for a normal population. Ninety‐three percent of the women completed the study. Both training modes were effective in reducing urinary leakage: with vaginal balls (P < 0.0001) and without (P < 0.019); and increasing pelvic floor muscle strength: with vaginal balls (P < 0.0039) and without (P < 0.0002). However, the reduction of urinary leakage after four months of exercise in the training group with vaginal balls was significantly better (P < 0.03) than the results in the group training with pelvic floor muscle exercises alone. The study found the weighted vaginal balls to be a good alternative for training pelvic floor muscles in women with stress urinary incontinence. Neurourol. Urodynam. 20:591–599, 2001. © 2001 Wiley‐Liss, Inc.
Selective suppression of sphincter activation during sacral anterior nerve root stimulation
Authors: Bhadra Narendra , Grünewald Volker , Creasey Graham , Mortimer J. Thomas
Published: August 2002

The purpose of this work was to electrically activate small‐diameter motor fibers in the sacral anterior roots innervating the urinary bladder, without activating the large‐diameter fibers to the sphincter. Quasitrapezoidal current pulses were applied through tripolar spiral nerve electrodes on selected anterior sacral roots during acute experiments on eight dogs, maintained under pentobarbital anesthesia. Pressures were recorded from the bladder and sphincter with catheter‐mounted gauges. Stimulation with biphasic quasitrapezoidal pulses showed decrease in sphincter recruitment with increasing pulse amplitudes. The minimum current amplitude that resulted in maximum sphincter suppression was used to stimulate the roots with trains of 20 Hz pulses, with 60 mL of saline filling the bladder. Pressures were also recorded when 100 μs rectangular pulse trains at 20 Hz, both continuous and intermittent, were applied. Trains of stimuli were applied before and after dorsal root rhizotomy. Suppression of sphincter activation was defined to be a percentage, [(Maximum pressure −Minimum pressure)/Maximum pressure × 100. The results from 22 roots in eight animals show that with single pulses, the average percentage suppression of sphincter activation was 76.3% (± 14.0). The minimum current for maximum sphincter suppression was 1.29 mA (± 0.62). The average bladder pressure evoked was 50 cm of water during pulse train stimulation, with no significant difference due to pulse type. With pulse trains, the sphincter pressures were significantly higher when the bladder was filled. Evacuation of fluid occurred in three animals with average flow rates of 1.0 mL/s. Neurourol. Urodynam. 21:55–64, 2002. © 2002 Wiley‐Liss, Inc.
Quantitative measurements of cerebral metabolic rate of oxygen utilization using MRI: a volunteer study
Authors: An Hongyu , Lin Weili , Celik Azim , Lee Yueh Z.
Published: August 2002

Quantitative estimates of cerebral metabolic rate of oxygen utilization using magnetic resonance imaging can have profound implications for the understanding of brain metabolic activity as well as the investigation of cerebrovascular disease. In this study, five normal volunteers were studied. All images were acquired on a Siemens 1.5 T scanner (Siemens Medical Systems Inc, Erlangen, Germany). Cerebral blood flow (CBF) was obtained in vivo with a dynamic imaging approach and the acquired images were post‐processed with the singular value decomposition method (SVD). In addition, a multi‐echo gradient echo/spin echo sequence was employed to provide MR estimates of oxygen extraction fraction (MR_OEF) in vivo. Subsequently, an absolute measure of MR cerebral metabolic rate of oxygen utilization (MR_CMRO2) was obtained in all subjects by taking the product of CBF and MR_OEF. A mean MR_CMRO2 of 28.94 ± 3.26 ml/min/100 g and 12.57 ± 3.11 ml/min/100 g was obtained for gray matter and white matter, respectively, suggesting that the gray matter utilizes more oxygen than white matter under normal physiological conditions. These results yield a gray matter to white matter CMRO2 ratio of 2.37 ± 0.37, which is comparable to the reported values in the literature. More studies are needed to further improve on the accuracy as well as shortening the required data acquisition time so that the proposed approaches can be utilized in a routine clinical setting. Copyright © 2001 John Wiley & Sons, Ltd.
Security‐enhanced packet video with dynamic multicast throughput adjustment
Authors: Chao Han‐Chieh , Wu T. Y. , Chen Jiann‐Liang
Published: August 2002

In recent years, the Internet population has increased at an explosive rate. Many problems exist because Internet packets are not encrypted and the bandwidth is not large enough. In this research, we propose a datagram encryption technique and dynamic bandwidth throughput adjustment. Security is enhanced using secret keys selected from a Key‐Database. Not only is a double encryption tunnel offered but also the whole plaintext can be encrypted more than one key depending on the encryption block size chosen. Copyright © 2001 John Wiley & Sons, Ltd.
Dynamic market‐driven allocation of network resources using genetic algorithms in a competitive electronic commerce marketplace
Authors: Ye Jian , Papavassiliou Symeon
Published: August 2002

In this paper, we propose a practical algorithm which finds cost‐efficient routes from Service Provider (SP) to Content Provider (CP) dynamically in a multi‐operator networking environment, using Genetic Algorithm (GA) concepts. The proposed algorithm is a kind of stochastic algorithm searching process in the solution space by emulating biological selection and reproduction. Copyright © 2001 John Wiley & Sons, Ltd.
On the number of spanning trees in directed circulant graphs
Authors: Lonc Zbigniew , Parol Krzysztof , Wojciechowski Jacek M.
Published: August 2002

Letgk(n) [respectively,fk(n)] be the maximum number of spanning trees in directed circulant graphs (respectively, regular directed graphs) withnvertices and out‐degrees equal tok> 1. We show thatgk(n) =kn(1+o(1))andfk(n) =kn(1+o(1)). Moreover, we prove thatg2(n) = ⌊(2n+ 1)/3⌋. © 2001 John Wiley & Sons, Inc.
Development of inhibition by ephrin‐A5 on outgrowth of embryonic spinal motor neurites
Authors: Wang H. , Chadaram S. R. , Norton A. S. , Laskowski M. B.
Published: August 2002

The spinal motor pool maps systematically onto the surface of muscles. This map is detectable in rat embryonic muscles, and is partially restored after reinnervation. Recent evidence shows that either overexpression or deletion of the ephrin‐A5 gene significantly disrupts the map, suggesting that ephrin‐A5 plays a critical role in the formation of this topography. Several studies have demonstrated that ephrin‐A5 is a repulsive molecule in the nervous system, including the neuromuscular system. To examine the development of sensitivity of ventral spinal axons to this inhibitory ligand, slices of E11 to E15 embryonic rat spinal cords were cocultured with membranes derived from ephrin‐A5‐expressing cell lines. We detected a progressive expression of inhibition by ephrin‐A5 between E11 and E15. By E15, rostral and caudal spinal neurites showed clear differences in responsiveness to the ephrin‐A5 ligand. Further, we found that at this age caudal neurites are more sensitive to changes of ephrin‐A5 concentration along a gradient. In addition, growth cones of caudal, more than rostral, neurites tended to assume a collapsed shape in the presence of the ligand. These results demonstrate a progressive development of sensitivity to ephrin‐A5, and suggest a divergence in this sensitivity between rostral and caudal spinal cord neurites. These results provide further insight into how subtle rostrocaudal differences in the development of sensitivity to ephrin‐A5 may explain, in part, neuromuscular topography. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 233–243, 2001
Subspace correction multi‐level methods for elliptic eigenvalue problems
Authors: Chan Tony F. , Sharapov Ilya
Published: August 2002

In this work, we apply the ideas of domain decomposition and multi‐grid methods to PDE‐based eigenvalue problems represented in two equivalent variational formulations. To find the lowest eigenpair, we use a “subspace correction” framework for deriving the multiplicative algorithm for minimizing the Rayleigh quotient of the current iteration. By considering an equivalent minimization formulation proposed by Mathew and Reddy, we can use the theory of multiplicative Schwarz algorithms for non‐linear optimization developed by Tai and Espedal to analyse the convergence properties of the proposed algorithm. We discuss the application of the multiplicative algorithm to the problem of simultaneous computation of several eigenfunctions also formulated in a variational form. Numerical results are presented. Copyright © 2001 John Wiley & Sons, Ltd.
Multiple imputation for missing data†‡
Authors: Patrician Patricia A.
Published: August 2002

Missing data occur frequently in survey and longitudinal research. Incomplete data are problematic, particularly in the presence of substantial absent information or systematic nonresponse patterns. Listwise deletion and mean imputation are the most common techniques to reconcile missing data. However, more recent techniques may improve parameter estimates, standard errors, and test statistics. The purpose of this article is to review the problems associated with missing data, options for handling missing data, and recent multiple imputation methods. It informs researchers' decisions about whether to delete or impute missing responses and the method best suited to doing so. An empirical investigation of AIDS care data outcomes illustrates the process of multiple imputation. © 2002 John Wiley & Sons, Res Nurs Health 25:76–84, 2002.
Urine flowing: A phenomenological study of living with a urinary catheter†
Authors: Wilde Mary H.
Published: August 2002

The experience of living with a long‐term urinary catheter was investigated with a community‐dwelling sample of 14 adults ranging in age from 35 to 95 who had worn a catheter for 6 months to 18 years. Data were obtained by audiotaped face‐to‐face interviews. Merleau‐Ponty's phenomenology and van Manen's methodology guided the study. Living with a urinary catheter was found to be like living with the forces of flowing water. People were keenly aware of the flow of urine through their catheters, and they noticed when their bags needed emptying or when urine drainage seemed sluggish or obstructed. The metaphor of urine flowing like water may provide a teaching heuristic for assisting clients in adjusting to living with a catheter. Implications for further research focus on understanding the relationship between sensitivity to the dynamics of urine flow and urinary tract infection. © 2002 John Wiley & Sons, Res Nurs Health 25:14–24, 2002.
Do environmental disturbances of an individual's growth and development influence the later bone involution processes? A study of two mediaeval populations
Authors: Rewekant Artur
Published: August 2002

Age‐dependent cortical bone loss was studied in two mediaeval Polish populations differing with regard to socio‐economic status, as well as the intensity of the occurrence of skeletal indicators of living conditions in the early stages of ontogenesis (compression of the skull base and the narrowing of the lumbar vertebral canal). Cortical bone loss was analysed on the basis of the radiographs of the second metacarpal. Cedynia population (better living conditions) is characterized by higher arithmetic means for the height of the skull base in comparison with Słaboszewo group (low socio‐economic status). In the case of the vertebral canal index, significant interpopulation differences apply only to men. Similar patterns of difference between groups under study regarding bone loss was also found. It turned out that males from Cedynia had more bone mass in adultus and maturus age categories; in females, these differences concern only adultus category. The study involved an analysis of a relationship between the characteristics measuring reactions to environmental stress in early stages of growth and the intensity of bone loss in adult life. We believe that the results presented justify a conclusion that both phenomena may be interrelated to a considerable degree. Copyright © 2001 John Wiley & Sons, Ltd.
Optimal sequence of landfills in solid waste management
Authors: André Francisco J. , Cerdá Emilio
Published: August 2002

Given that landfills are depletable and replaceable resources, the right approach, when dealing with landfill management, is that of designing an optimal sequence of landfills rather than designing every single landfill separately. In this paper, we use Optimal Control models, with mixed elements of both continuous‐and discrete‐time problems, to determine an optimal sequence of landfills, as regarding their capacity and lifetime. The resulting optimization problems involve splitting a time horizon of planning into several subintervals, the length of which has to be decided. In each of the subintervals some costs, the amount of which depends on the value of the decision variables, have to be borne. The obtained results may be applied to other economic problems such as private and public investments, consumption decisions on durable goods, etc. Copyright © 2001 John Wiley & Sons, Ltd.
Fluorosilicone elastomer based on the poly[(3,3,3‐trifluoropropyl)methyl‐siloxane‐co‐(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)methylsiloxane]
Authors: Furukawa Yutaka , Shin‐ya Seiji , Saito Masayuki , Narui Shin‐ichiro , Miyake Haruhisa
Published: August 2002

Fluorosilicone elastomer based on the poly[(3,3,3‐trifluoropropyl)methylsiloxane‐co‐(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)methylsiloxane] was studied. First, the synthesis of fluorosilicone polymer based on the poly[(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)methylsiloxane] (PNFHMS) was examined by the polymerization of 1,3,5‐tris(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)‐1,3,5‐trimethylcyclotrisiloxane (C4F9D3) by sodium hydroxide. On the contrast of the polymerization of the commercially available 1,3,5‐tris(3,3,3‐trifluoropropyl)‐1,3,5‐trimethylcyclotrisiloxane (CF3D3), the polymerization of C4F9D3 with sodium hydroxide resulted in the formation of 1,3,5,7‐tetrakis(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)‐1,3,­5,7‐tetramethylcyclotetrasiloxane : [C4F9CH2CH2(CH3)SiO]4 (C4F9D4) as the major product. It was due to the easy occurrence of the depolymerization by the back‐biting mechanism, because C4F9D4 is more stable ­than 1,3,5,7‐tetrakis(3,3,3‐trifluoropropyl)‐1,3,5,7‐tetramethylcyclotetrasiloxane : [CF3CH2CH2(CH3)SiO]4 (CF3D4). The above result made us to conclude that it was difficult to apply the polymer based on PNFHMS to heat vulcanizable elastomers and to investigate the elastomer based on the poly[(3,3,3‐trifluoropropyl)methylsiloxane‐co‐(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)methylsiloxane]. C4F9D3 and CF3D3 were co‐polymerized successfully by sodium hydroxide and formulated with the silica treated by CF3D3. The use of silica treated with methylsilyl unit failed, because creep‐hardening phenomenon occurred. This elastomer was evaluated about some mechanical properties, and the resistance to organic solvents, and a fuel. The advantage that can be detected from the introduction of [C4F9C2H4‐(CH3)SiO] unit was that the resistance to the polar solvents such as acetone and dimethylformamide was improved. Copyright © 2001 John Wiley & Sons, Ltd.
Preparation method of porous polymer materials by radiation technique and its application
Authors: Kumakura M.
Published: August 2002

The radiation polymerization of hydrophilic hydroxyethyl methacrylate monomer solution at temperatures below 0 °C leads to the formation of a porous structure in the polymers. The melting peak of the eutectic water–monomer composition at the eutectic point (above −24 °C) could be distingushed and a glass transition temperature was observed at −96 °C.

The porous structure was developed after melting small ice pieces in the polymers after polymerization. The porous structure formed above 0 °C contained discontinuous pores and that formed below 0 °C had continuous pores leading to reticular structure. In a mixture of water –dioxane –monomer, the pore diameter decreased with increasing monomer concentration. Replacing dioxane with decane led to a maximum pore diameter at 70% monomer concentration. The pore diameter in 70% monomer concentration using water and dioxane was 1∼4 µm, maximum activity in immobilized enzyme tablets was observed at this diameter. The porous structure was also varied by controlling the polymerization temperature. The durability of the immobilized enzyme tablets was demonstrated by the retention of high enzyme activities after repeated batch enzyme reactions. Copyright © 2001 John Wiley & Sons, Ltd.
Stereoregular silicon‐containing ­polymers
Authors: Kawakami Yusuke
Published: August 2002

Optically active (R)‐methylphenylpropargylsilane and (S)‐2‐(1‐naphthyl)‐2‐phenyl‐5,5‐dimethyl‐1‐oxa‐2,5‐disilacyclopentane were prepared, and stereoregular and optically active polymers were obtained via hydrosilylation or ring‐opening polymerization. Both polymerization reactions proceeded stereoselectively, and the tacticity of the polymers reflected the optical purity of the monomers. Copyright © 2001 John Wiley & Sons, Ltd