bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of medication on EMG patterns in individuals with Parkinson's disease
Authors: Robichaud Julie A. , Pfann Kerstin D. , Comella Cynthia L. , Corcos Daniel M. 
Published: October 2002

AbstractIndividuals with Parkinson's disease show dramatic improvements in their ability to move when medicated. However, the neural cause of this improvement is unclear. One hypothesis is that neural activation patterns, as measured by surface electromyography (EMG), are normalized by medication. We tested this hypothesis by investigating the effect of medication on the electromyographic (EMG) patterns recorded when individuals with idiopathic Parkinson's disease performed elbow flexion movements over three movement distances while off and on antiparkinsonian medication. When the subjects were off medication, they lacked the ability to modulate the agonist EMG burst duration with changes in movement distance. The ability to modulate agonist EMG burst duration is characteristic of the EMG patterns observed in healthy subjects. Also, multiple agonist bursts were exhibited during the acceleration phase. As expected, medication diminished the clinical signs of Parkinson's disease, increased movement speed, and increased the magnitude of the first agonist burst. Medication did not restore agonist burst duration modulation with movement distance, did not change the frequency of agonist bursting, and did not alter the timing of the antagonist activation. These results show that medication does not alter the temporal profile of EMG activation. © 2002 Movement Disorder Society
Freezing of gait in postmortem‐confirmed atypical parkinsonism
Authors: Müller Jörg , Seppi Klaus , Stefanova Nadia , Poewe Werner , Litvan Irene , Wenning Gregor K. 
Published: October 2002

AbstractThe frequency and pathophysiology of freezing of gait (FoG) in atypical parkinsonism is unknown. We analysed the frequency of FoG in postmortem‐confirmed atypical parkinsonian disorders (APD) comprising corticobasal degeneration (CBD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Sixty‐six patients with pathologically confirmed APD (CBD, n = 13; DLB, n = 14; MSA, n = 15; PSP, n = 24) formed the basis for a multicenter clinicopathological study. Clinical features at first and last clinical visit were abstracted from patient records on standardized forms following strict instructions. At the first visit (median 36 months after symptom onset), 24% of APD had FoG (CBD, 8%; DLB, 21%; PSP, 25%; MSA, 40%). Logistic regression analysis showed a significant association of FoG and urinary incontinence (P = 0.04) at first visit. At last visit, 47% of APD had FoG (CBD, 25%; PSP, 53%; DLB, 54%; MSA, 54%). Clinicopathological correlation based on routine postmortem examination failed to identify a consistent neuropathological substrate of FoG. This study demonstrates that (1) FoG is common in APD, and (2) urinary incontinence is significantly associated with FoG in these disorders. Whether FoG and urinary incontinence share similar neuropathological substrates remains to be determined by future studies. © 2002 Movement Disorder Society
Improved performance of photonic band‐gap microstripline structures with the use of Chebyshev distributions
Authors: Karmakar Nemai C. 
Published: October 2002

AbstractConventional uniform circular‐patterned photonic band gaps (PBGs) have constraints in the broadband passband and stopband performance because of the high ripple heights in S parameters. This Letter suggests a novel configuration with nonuniform dimensions of circular‐patterned PBG to improve both pass‐ and stopband bandwidths and the ripples. The dimensions of the circles are varied proportionally to the relative Chebyshev amplitudes of a 10‐element PBG array, and the dispersion characteristics are analyzed. It is seen that the Chebyshev distribution of the circular‐patterned PBG line produces excellent performance by suppressing ripples and yielding better selectivity at cutoffs. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 1–5, 2002; DOI 10.1002/mop.10212
Measurement of dielectric and radiation losses for flexible circular dielectric waveguides in Q‐band
Authors: Kim Ki Young , Tae Heung‐Sik , Lee Jeong‐Hae 
Published: October 2002

AbstractExperimental results are presented for the dielectric and radiation losses from flexible circular PTFE waveguides in the Q‐band. The dielectric and radiation losses from rod and tube waveguides were found to depend strongly on the design parameters, such as the operating frequency, area of the dielectric region in the guiding cross sections, and curvature radii of the bending. The dielectric losses from the straight guides showed a relatively good agreement with the theoretical results. The radiation losses with a small curvature radius, which cannot be predicted using current theories, were determined based on the differences between the measured insertion losses and the dielectric losses. The validity of the current results was confirmed based on the fractional power flow ratios in each region of the waveguides. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 000–000, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10529
Effect of temperature on LiMnTi ferrite based microstrip circulator
Authors: Dubey Ashish , Tyagi G. S. , Srivastava G. P. , Badola N. K. , Jain K. K. 
Published: October 2002

AbstractA conventional three port microstrip junction circulator has been experimentally demonstrated in the X‐band frequency region, by depositing the thin films of Cr‐Cu‐Au over the LiMnTi bulk polycrystalline ferrite substrate. Characteristics of fabricated circulator have been studied by keeping it in the moderate thermal range. Variations in the characteristics of fabricated circulator have been analyzed on the basis of variation of saturation magnetization, dielectric constant and loss tangent of ferrite material with the external atmospheric temperature. Experimental results qualitatively agree with the theoretical ones. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 114–117, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10532
Application of an optical birefringence interferometer to photothermal detection
Authors: Xu X. D. , Kuo P. K. , Zhang S. Y. , Shui X. J. , Zhang Z. N. 
Published: October 2002

AbstractIn this paper a birefringence interferometer is used for detecting both change in reflectivity and surface deformation caused by photothermal effect or thermal waves excited by anyother pump source. The instrument is very simple, with high immunity against noise and sensitivity. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 140–143, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10540
An experimental study of small self‐resonant antennas for wireless applications
Authors: Ali M. , Stuchly S. S. , Caputa K. 
Published: October 2002

AbstractTwo types of self‐resonant antennas, meander and sinusoidal are experimentally characterized. Input impedance, bandwidth, and radiation pattern data for such antennas are given. It is demonstrated that antennas that are 34% shorter than quarter‐wave monopoles and have 3.8 dBi of peak gain can be designed with acceptable bandwidth. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 143–145, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10541
Application of adaptive local cosine transform to detection and estimation of ultra‐wideband signals through dispersive propagation channels
Authors: Deng Hai , Ling Hao 
Published: October 2002

AbstractThe adaptive local cosine transform (ALCT) is applied to identify the time‐frequency distribution of an ultra‐wideband signal transmitted through a dispersive propagation channel in the presence of noise. The estimated time‐frequency distribution is then used to detect subsequently transmitted signals. Simulation results show the ALCT outperforms the traditional short‐time Fourier transform. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 150–153, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10543
Patch array as artificial magnetic conductors for antenna gain improvement
Authors: Zhang Ying , von Hagen Jürgen , Wiesbeck Werner 
Published: October 2002

AbstractA patch array is tested as reflector. The reflection coefficient for a plane wave is measured, the findings are explained by the functioning of a single patch. A λ/2 dipole and a 2‐arm spiral antenna are fitted with this reflector. It enhances the gain with the complete structure remaining small. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 172–175, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10548
Line integral representation of physical optics diffraction field from perfectly conducting plates
Authors: Cui Suomin , Ando Makoto 
Published: October 2002

AbstractAn alternative approach for analyzing diffraction field for physical optics (PO) is presented in this paper. This approach separates geometrical optics field and diffraction field from the total field analytically by using field equivalence principle or the divergence theorem and choosing the special surfaces which lie on the reflection and shadow boundaries, and then transfers the surface integral which represents the diffraction field into simple line integral analytically. Two types of representations of PO field lead to the two types of line integral expressions for PO diffraction field. One is very simple and is not reported in the literature to the best knowledge of the authors, and another is identical with available result, which can be considered as alternative derivation of the available result. The proposed approach differs from other high frequency analysis in that it's not asymptotic evaluation of radiation integration, or heuristic or empirical. The superiority of this new analysis is demonstrated numerically. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 206–211, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10559
On the design of polarization‐insensitive semiconductor optical amplifiers
Authors: Wartak M. S. , Weetman P. 
Published: October 2002

AbstractWe have used the 4 × 4 Luttinger–Kohn Hamiltonian to analyse the presence of delta‐strain in quantum well on the polarization properties of semiconductor optical amplifiers. The analysis is performed for a 1.55 μm InGaAsP/InP lattice matched system grown in the [001] direction with and without the electrostatic effects of the carrier charges. The importance of electrostatic effects is indicated. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 227–230, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10564
Are TrueFISP images T2/T1‐weighted?
Authors: Huang Teng‐Yi , Huang Ing‐Jye , Chen Cheng‐Yu , Scheffler Klaus , Chung Hsiao‐Wen , Cheng Hui‐Cheng 
Published: October 2002

AbstractImages acquired using the TrueFISP technique (true fast imaging with steady‐state precession) are generally believed to exhibit T2/T1‐weighting. In this study, it is demonstrated that with the widely used half‐flip‐angle preparation scheme, approaching the steady state requires a time length comparable to the scan time such that the transient‐state response may dominate the TrueFISP image contrast. Two‐dimensional images of the human brain were obtained using various phase‐encoding matrices to investigate the transient‐state signal behavior. Contrast between gray and white matter was found to change significantly from proton‐density‐ to T2/T1‐weighted as the phase‐encoding matrix size increased, which was in good agreement with theoretical predictions. It is concluded that TrueFISP images in general exhibit T2/T1‐contrast, but should be more appropriately regarded as exhibiting a transient‐state combination of proton‐density and T2/T1 contrast under particular imaging conditions. Interpretation of tissue characteristics from TrueFISP images in clinical practice thus needs to be exercised with caution. Magn Reson Med 48:684–688, 2002. © 2002 Wiley‐Liss, Inc.
Degeneracy in inventory models
Authors: Lau Amy Hing‐Ling , Lau Hon‐Shiang , Pyke David F. 
Published: October 2002

AbstractIn order‐quantity reorder‐point formulations for inventory items where backordering is allowed, some of the more common ways to prevent excessive stockouts in an optimal solution are to impose either a cost per unit short, a cost per stockout occasion, or a target fill rate. We show that these popular formulations, both exact and approximate, can become “degenerate” even with quite plausible parameters. By degeneracy we mean any situation in which the formulation either cannot be solved, leads to nonsensical “optimal” solutions, or becomes equivalent to something substantially simpler. We explain the reasons for the degeneracies, yielding new insight into these models, and we provide practical advice for inventory managers. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 686–705, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10037
Direction of action potential propagation influences calcium increases in distal dendrites of the cricket giant interneurons
Authors: Ogawa Hiroto , Baba Yoshichika , Oka Kotaro 
Published: October 2002

AbstractTo understand the relationship between the propagation direction of action potentials and dendritic Ca2+ elevation, simultaneous measurements of intracellular Ca2+ concentration ([Ca2+]i) and intradendritic membrane potential were performed in the wind‐sensitive giant interneurons of the cricket. The dendritic Ca2+ transients induced by synaptically‐evoked action potentials had larger amplitudes than those induced by backpropagating spikes evoked by antidromic stimulation. The amplitude of the [Ca2+]i changes induced by antidromic stimuli combined with subthreshold synaptic stimulation was not different from that of the Ca2+ increases evoked by the backpropagating spikes alone. This result means that the synaptically activated Ca2+ release from intracellular stores does not contribute to enhancement of Ca2+ elevation induced by backpropagating spikes. On the other hand, the synaptically evoked action potentials were also increased at distal dendrites in which the Ca2+ elevation was enhanced. When the dendritic and axonal spikes were simultaneously recorded, the delay between dendritic spike and ascending axonal spike depended upon which side of the cercal nerves was stimulated. Further, dual intracellular recording at different dendritic branches illustrated that the dendritic spike at the branch arborizing on the stimulated side preceded the spike recorded at the other side of the dendrite. These results suggest that the spike‐initiation site shifts depending on the location of the activated postsynaptic site. It is proposed that the difference of spike propagation manner could change the action potential waveform at the distal dendrite, and could produce synaptic activity‐dependent Ca2+ dynamics in the giant interneurons. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 44–56, 2002
Robust parameter‐free algebraic multilevel preconditioning
Authors: Notay Y. 
Published: October 2002

AbstractTo precondition large sparse linear systems resulting from the discretization of second‐order elliptic partial differential equations, many recent works focus on the so‐called algebraic multilevel methods. These are based on a block incomplete factorization process applied to the system matrix partitioned in hierarchical form. They have been shown to be both robust and efficient in several circumstances, leading to iterative solution schemes of optimal order of computational complexity. Now, despite the procedure is essentially algebraic, previous works focus generally on a specific context and consider schemes that use classical grid hierarchies with characteristic mesh sizes h,2h,4h, etc. Therefore, these methods require some extra information besides the matrix of the linear system and lack of robustness in some situations where semi‐coarsening would be desirable. In this paper, we develop a general method that can be applied in a black box fashion to a wide class of problems, ranging from 2D model Poisson problems to 3D singularly perturbed convection–diffusion equations. It is based on an automatic coarsening process similar to the one used in the AMG method, and on coarse grid matrices computed according to a simple and cheap aggregation principle. Numerical experiments illustrate the efficiency and the robustness of the proposed approach. Copyright © 2002 John Wiley & Sons, Ltd.
A box scheme for transcritical flow
Authors: Johnson T. C. , Baines M. J. , Sweby P. K. 
Published: October 2002

AbstractThe accurate computer simulation of river and pipe flow is of great importance in the design of urban drainage networks. The use of implicit numerical schemes allows the time step to be chosen on the basis of accuracy rather than stability, offering a potential computational saving over explicit methods.The highly successful Box Scheme is an implicit method which can be used to model a wide range of subcritical and supercritical flows. However, care must be taken over the modelling of transcritical flows since, unless the correct internal boundary conditions are imposed, the scheme becomes unstable. The necessity of accurately tracking all the critical interfaces and treating them accordingly can be algorithmically complex and in practice the underlying mathematical model is often modified to ensure that the flow remains essentially subcritical. Such a modification however inevitably leads to additional errors and incorrect qualitative behaviour can be observed.In this paper we show how the technique of ‘residual distribution’ can be successfully implemented in order to accurately model unsteady transcritical flow without the need to know a priori which regions of the computational domain correspond to subcritical and supercritical flow. When used in conjunction with a form of artificial smoothing, the resulting method generates very high resolution results even for transcritical problems involving shocks, as can be seen in the numerical results. Copyright © 2002 John Wiley & Sons, Ltd.
Compensatory bone remodelling in moose: a study of age, sex, and cross‐sectional cortical bone dimensions in moose at Isle Royale National Park
Authors: Hindelang Mary , Peterson Rolf O. , Maclean Ann L. 
Published: October 2002

AbstractWe studied interrelationships among age, sex, and cross‐sectional cortical bone dimensions using quantitative computed tomography (QCT) scans of metatarsal bones of 180 moose (Alces alces) that died in Isle Royale National Park, Michigan. As a large‐bodied quadruped with demanding ecological constraints on movement and behaviour, a moose experiences different weight‐bearing and mechanical stressors than humans, to whom most existing studies of mechanical adaptations of bone pertain. In moose, both sexes showed significant subperiosteal expansion and an increase in medullary area, with an overall increase in cortical bone area over time. Female moose did not exhibit cortical thinning or reduction in cross‐sectional area with age, rather they showed an increase in cortical bone area with periosteal apposition exceeding endosteal resorption, similar to the males. We also found that moose undergo changes in bone geometry through remodelling of bone similar to humans, suggesting a compensatory mechanism for increasing bone strength under conditions of decline in bone mineral density with age. Copyright © 2002 John Wiley & Sons, Ltd.
Editorial note: Introduction to research articles
Authors: Reuter Peter 
Published: October 2002

AbstractJPAM aspires to cover a wide range of policy topics and variety of methods. This issue shows the usual range
of coverage: welfare reform, public management, methodology, and environmental decisionmaking. Articles on
unfamiliar topics or using unfamiliar methods sometimes challenge readers. Meanwhile, abstracts aim to summarize
the article for specialist readers rather than for a broader audience. One remedy for this problem, the
Editorial Board suggested, is a more accessible and less technical introductory essay that gives the reader a
better sense of what makes each article worth reading; the Brookings Papers on Macroeconomic Activities provides
a long‐established model of this kind of introduction. Surely no one will read every article, but this
endeavor may lead some readers to peruse articles they would otherwise have skipped. The next four issues will
serve as an experimental period, at the end of which I will seek feedback as to whether the essays are helpful.
The summaries of the articles are initially prepared by the authors and then edited for integration into this
essay. © 2002 by the Association for Public Policy Analysis and Management.
Heterogeneous expression of cell adhesion molecules by endothelial cells in ARDS
Authors: Müller Annette M. , Cronen Claus , Müller Klaus‐Michael , Kirkpatrick C. James 
Published: October 2002

AbstractARDS (acute respiratory distress syndrome) can be associated with septic shock and multiple organ failure caused by an uncontrolled systemic inflammatory response to Gram‐negative bacterial infection. While in animal models the key role of the endothelial adhesion molecules ICAM‐1, E‐selectin, and VCAM in ARDS has been extensively studied, there are scarcely any corresponding pathomorphological studies of human lung tissue. Hence, little is known about whether there is a comparable, or even heterogeneous, expression pattern of these molecules in the human pulmonary vasculature. This study was therefore undertaken to investigate the immunohistochemical expression of the constitutively expressed PECAM (CD31) and the inducible molecules ICAM‐1, E‐selectin, and VCAM in ARDS lungs from patients who had died in septic shock induced by Gram‐negative bacteria. While in all specimens (ARDS and normal lungs) there was homogeneous strong expression of PECAM in all vessels, ICAM‐1 was clearly up‐regulated in ARDS lungs. E‐selectin and VCAM were not expressed by endothelial cells (ECs) in normal lungs, but in ARDS lungs there was strong expression of both molecules in larger vessels, while in the capillaries there was only mosaic‐like weak expression of a few ECs. This immunohistochemical investigation demonstrates the induction and up‐regulation of adhesion molecules in human ARDS lungs, comparable to that described in animal models. There is also markedly heterogeneous expression of E‐selectin and VCAM, indicating toporegional differences in the function of pulmonary ECs. Copyright © 2002 John Wiley & Sons, Ltd.
Polymerization of methyl methacrylate by 2‐pyrrolidinone and n‐dodecyl mercaptan
Authors: Hu Yu‐Hsiang , Chen Chuh‐Yung 
Published: October 2002

AbstractThe bulk polymerization of methyl methacrylate initiated with 2‐pyrrolidinone and n‐dodecyl mercaptan (R‐SH) has been explored. This polymerization system showed “living” characteristics; for example, the molecular weight of the resulting polymers increased with reaction time by gel permeation chromatographic analysis. Also, the polymer was characterized by Fourier transform infrared spectroscopy, 1H NMR, and 13C NMR techniques. The polymer end with the iniferter structures was found. By the initial‐rate method, the polymerization rate depended on [2‐pyrrolidinone]1.0 and [R‐SH]0. Combining the structure analysis and the polymerization‐rate expression, a possible mechanism was proposed. n‐Dodecyl mercaptan served dual roles—as a catalyst at low conversion and as a chain‐transfer agent at high conversion. Finally, the thermal properties were studied, and the glass‐transition temperature and thermal‐degradation temperature were, respectively, 25 and 80–100 °C higher than that of the azobisisobutyronitrile system. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3692–3702, 2002