bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reproducibility of motor unit number estimation in individual subjects
Authors: Simmons Zachary , Epstein David K. , Borg Bryson , Mauger David T. , Kothari Milind J. , Shefner Jeremy M. 
Published: August 2002

AbstractAlthough the reproducibility of motor unit number estimation (MUNE) for groups of subjects has been studied, there is little such data for individuals. Prediction intervals represent a tool to study individual MUNE reproducibility and represent the range of values expected for a future MUNE if the true number of motor units remains unchanged. MUNE was performed using the statistical method on 48 normal individuals. The prediction interval was found to be a function of the intrasubject coefficient of variation. Using a commercial manufacturer's recommended technique and software, prediction intervals were found to be so broad as to be of uncertain value. We found that by averaging two MUNE observations for each determination, and using the method of weighted averages for calculating the size of an average single motor unit potential, the intrasubject coefficient of variation was reduced from 16.48% to 8.77%, and the 90% prediction interval became sufficiently narrow to be clinically useful. False‐negative rates were also lowered substantially using these techniques. Thus, simple modifications of an existing MUNE program improved the clinical utility of this program for the longitudinal study of patients in whom changes in motor unit number over time are of importance, such as those with motor neuron diseases. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 467–473, 2001
The susceptibility of muscle cells to oxidative stress is independent of nitric oxide synthase expression
Authors: Zhuang Weiyun , Eby Josh C. , Cheong Monica , Mohapatra Pramit K. , Bredt David S. , Disatnik Marie‐Hélène , Rando Thomas A. 
Published: August 2002

AbstractThe free radical, nitric oxide (NO·), has been implicated in the pathogenesis of muscular dystrophies because the enzyme, nitric oxide synthase (NOS), which produces NO·, binds to the dystrophin–glycoprotein complex (DGC). In various studies of tissue samples from human and animal muscular dystrophies due to DGC defects, correlations between reductions of NOS activity and disease severity have been reported. To test for any direct effect of NOS expression on muscle cell susceptibility, we examined muscle cells in vitro under conditions of experimentally altered NOS activity. There were no differences in susceptibility to oxidative stress between differentiated myotube cultures from wild‐type and from neuronal NOS (nNOS)‐deficient mice. Likewise, pharmacological inhibition of NOS did not alter cellular susceptibility to oxidative challenges. Overexpression of NOS neither enhanced nor diminished cellular susceptibility to oxidative stress. Finally, we assessed the effect of NOS overexpression on myotube cultures from dystrophin‐deficient (mdx) mice. NOS protein was localized to both membrane and cytosolic compartments in the transduced cells. Still, no difference in susceptibility to oxidative stress was found between the NOS‐overexpressing cells and control cells. These data suggest that muscle cell susceptibility to oxidative challenges is independent of the level of NOS expression. Therefore, any role NO· may play in the pathogenesis of muscular dystrophies is likely to be independent of its effect on the redox state of the cell. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 502–511, 2001
Prolonged median sensory latency as a predictor of future carpal tunnel syndrome
Authors: Werner Robert A. , Gell Nancy , Franzblau Alfred , Armstrong Thomas J. 
Published: August 2002

AbstractThe purpose of the study was to determine whether abnormal median sensory nerve conduction among asymptomatic workers was predictive of future symptoms suggestive of carpal tunnel syndrome (CTS). This was a prospective study involving 77 workers who were identified as asymptomatic cases with electrodiagnostic findings of median mononeuropathy compared to an age‐ and sex‐matched control group. Follow‐up was completed an average of 70 months later, and subjects who reported pain, numbness, tingling, or burning in the distribution of the median nerve, based upon a hand diagram, were classified as having CTS symptoms. The follow‐up participation rate was 70%. Among subjects with abnormal median sensory latencies, 23% went on to develop symptoms consistent with CTS within the follow‐up period, compared with 6% in the control group (P = .010). Age and hand repetition were also risk factors for CTS, but the majority of asymptomatic workers with a median mononeuropathy do not become symptomatic over an extended time. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1462–1467, 2001
A sequential attribute sampling inspection game for item facilities
Authors: Canty Morton , Rothenstein Daniel , Avenhaus Rudolf 
Published: August 2002

AbstractThe routine inspection of facilities storing large numbers of identical items is modeled as a two‐person, sequential game. Timely detection of illegal activity is parameterized in terms of a critical time to detection, and equilibria are derived which provide inspection strategies. Necessary conditions for deterrence of illegal behavior are discussed. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 496–505, 2001
Decoupling of the short‐term hemodynamic response and the blood oxygen concentration
Authors: Janz Clemens , Schmitt Christina , Kornmayer Jens , Speck Oliver , Hennig Jürgen 
Published: August 2002

AbstractNeuronal activation leads to an increase in the local cortical perfusion. The exact regulatory mechanisms leading to these changes are still unknown. To elucidate the role of oxygen in the initial hemodynamic regulation, a disactivation paradigm was performed with fMRI. A stimulus was applied following a previous extended activation in order to evoke physiological variations of the local oxygen concentration. The results demonstrate that the initial hemodynamic response time is independent of the local blood oxygen concentration. Copyright © 2001 John Wiley & Sons, Ltd.
Abbrevations used:

BOLD

blood oxygenation level dependent

CBF

cerebral blood flow

CMRO2

cerebral metabolic rate of oxygen

fMRI

functional magnetic resonance imaging

FOV

field‐of‐view

GE‐EPI

gradient echo–echo planar imaging
Predicting BOLD signal changes as a function of blood volume fraction and resolution
Authors: Cheng Yu‐Chung N. , Haacke E. Mark 
Published: August 2002

AbstractThe appropriate choice of resolution in fMRI remains an open question. To address this issue, we simulate the signal change between activated and resting states as a function of blood volume fraction (λ). From these results, the relative contrast‐to‐noise ratio (CNR) from the resting to the activated state can be calculated as a function of resolution. We consider different vessel orientations and note that, in most cases, the most efficient scanning procedure is for low resolution imaging. To overcome this limitation, a T1 enhancing contrast agent is proposed to increase the signal from the blood and, hence, the intravascular contribution to the BOLD effect. We show that this effect dramatically increases both the signal changes and the efficiency of high‐resolution imaging and should lead to much better visualization and localization of parenchymal changes. Copyright © 2001 John Wiley & Sons, Ltd.
Improving network service quality with explicit TCP window control
Authors: Aweya James , Ouellette Michel , Montuno Delfin Y. , Yao Zhonghui 
Published: August 2002

AbstractWe describe in this paper a new TCP rate control scheme based on a simple recursive algorithm. The idea behind the algorithm is to match the offered network load to the available resources by modifying at an intermediate network element, the receiver's advertised window in TCP acknowledgments returning to the source. We show through simulations that the scheme can efficiently control TCP traffic to limit queue buildups and buffer requirements at the network nodes, resulting in significant improvements in delay, packet loss rates, fairness, throughput and link utilization. Copyright © 2001 John Wiley & Sons, Ltd.
Secure key agreement for group communications
Authors: Yang Wen‐Her , Shieh Shiuh‐Pyng 
Published: August 2002

AbstractA secure key agreement protocol for group communications is proposed in this paper, which ensures the authenticity of group members and the privacy of group messages, and provides the properties of perfect forward and backward privacy. In a group session, the common key is collaboratively established by all participants, hence the overhead of key agreement is balanced among group members. Copyright © 2001 John Wiley & Sons, Ltd.
Worst‐case ratios of networks in the rectilinear plane
Authors: Brenner Ulrich , Vygen Jens 
Published: August 2002

AbstractFor point sets in the rectilinear plane, we consider the following five measures of the interconnect length and prove bounds on the worst‐case ratio: minimum Steiner tree, minimum star, clique, minimum spanning tree, and bounding box. In particular, we prove that, for any set of n points, (n − 1) times the shortest Steiner tree is less or equal to the clique unless n = 4 and the minimum spanning tree is less or equal to the shortest star unless n ∈ {3, 4, 5}. © 2001 John Wiley & Sons, Inc.
Bitter substances suppress afferent responses to an appetitive mixture: Evidence for peripheral integration of chemosensory stimuli
Authors: Li Yuxing , Perruccio Elizabeth , Zhang Xian , Kleinhaus Anna L. 
Published: August 2002

AbstractThe processes that lead from detection of chemicals, transduction, and coding with the appropriate message to initiate ingestion of a palatable meal or to reject a potentially noxious substance are poorly understood in vertebrates owing to the complex organization of the taste system. As a first step in elucidating the cellular basis of the behavioral differences elicited by appetitive stimuli and bitter compounds, we recorded from the afferent nerves conveying peripheral chemosensory information to the CNS in the head of the leech, Hirudo medicinalis. Superfusion of the chemosensory region of the lip of Hirudo with a mixture of NaCl (150 mM) and arginine (1 mM), an appetitive solution that elicits ingestion, increased the neuronal activity in the afferent cephalic nerves, for example (Zhang X, Wilson RJ, Li Y, Kleinhaus AL. 2000. Chemical and thermal stimuli have short‐lived effects on the Retzius cell in the medicinal leech. J Neurobiol 43:304–311.). In the present paper we show that superfusing the lip with quinine or denatonium reduced the basal neural activity in the afferents. Furthermore, these bitter substances in the appetitive solution counteracted the increased activity the appetitive solution evoked in the cephalic nerves. Thus, the neural activity evoked by the application of appetitive and aversive stimuli to the chemosensory area of the lip paralleled the opposite behavioral responses to the same chemicals. The results suggest that individual leech taste cells possess receptors for both types of stimuli. Therefore, the leech may be a good model system in which to study peripheral taste events in cells that may possess multiple receptors and transduction mechanisms that interact to integrate information. © 2001 John Wiley & Sons, Inc. J Neurobiol 49: 255–263, 2001
Steps in the formation of a bipolar outgrowth pattern by cultured neurons, and their substrate dependence
Authors: de‐Miguel Francisco F. , Vargas Javier 
Published: August 2002

AbstractWe studied the steps in the formation of the bipolar outgrowth pattern of cultured adult Anterior Pagoda (AP) neurons of the leech growing on a central nervous system (CNS) homogenate as substrate. This pattern, which consists of two primary neurites directed in opposite directions plus some bifurcations, resembles their embryonic pattern but is different from the patterns they develop in culture on leech laminin or Concanavalin A as substrates. In eight neurons that were studied, one primary neurite formed and branched several hours before the second one. Time‐lapse video analysis showed that between 12 and 36 h of growth, the more proximal branch of the early neurite migrated retrogradely, rotated, and formed the second primary branch. Both neurites elongated until the total neurite length reached 130–160 μm, when the elongation of primary neurites became synchronous with the retraction of secondary processes, suggesting competition. The substrate dependence of these events was tested by plating AP neurons on leech laminin. On this substrate AP neurons produced multiple independent primary neurites with branches. Retraction of some large branches was followed by their regrowth, and did not correlate with the changes in other neurites. We propose that the dynamics in the formation of the bipolar outgrowth pattern of AP neurons arise from inhibitory extracellular matrix molecules, which reduce the synthesis of precursors for neurite formation. © 2002 Wiley Periodicals, Inc. J Neurobiol 50: 106–117, 2002; DOI 10.1002/neu.10017
Regulated appearance of NMDA receptor subunits and channel functions during in vitro neuronal differentiation
Authors: Jelitai Márta , Schlett Katalin , Varju Patrícia , Eisel Ulrich , Madarász Emília 
Published: August 2002

AbstractThe schedule of NMDA receptor subunit expression and the appearance of functional NMDA‐gated ion channels were investigated during the retinoic acid (RA) induced neuronal differentiation of NE‐4C, a p53‐deficient mouse neuroectodermal progenitor cell line. NR2A, NR2B, and NR2D subunit transcripts were present in both nondifferentiated and neuronally differentiated cultures, while NR2C subunits were expressed only transiently, during the early period of neural differentiation. Several splice variants of NR1 were detected in noninduced progenitors and in RA‐induced cells, except the N1 exon containing transcripts that appeared after the fourth day of induction, when neuronal processes were already formed. NR1 and NR2A subunit proteins were detected both in nondifferentiated progenitor cells and in neurons, while the mature form of NR2B subunit protein appeared only at the time of neuronal process elongation. Despite the early presence of NR1 and NR2A subunits, NMDA‐evoked responses could be detected in NE‐4C neurons only after the sixth day of induction, coinciding in time with the expression of the mature NR2B subunit. The formation of functional NMDA receptors also coincided with the appearance of synapsin I and synaptophysin. The lag period between the production of the subunits and the onset of channel function suggests that subunits capable of channel formation cannot form functional NMDA receptors until a certain stage of neuronal commitment. Thus, the in vitro neurogenesis by NE‐4C cells provides a suitable tool to investigate some inherent regulatory processes involved in the initial maturation of NMDA receptor complexes. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 54–65, 2002
Behavioral discrimination of sexually dimorphic calls by male zebra finches requires an intact vocal motor pathway
Authors: Vicario David S. , Naqvi Nasir H. , Raksin Jonathan N. 
Published: August 2002

AbstractVocal communication between zebra finches includes the exchange of long calls (LCs) as well as song. By using this natural call behavior and quantifying the LCs emitted in response to playbacks of LCs of other birds, we have previously shown that adult male zebra finches have a categorical preference for the LCs of females over those of males. Female LCs are acoustically simpler than male LCs, which include complex acoustic features that are learned during development. Production of these male‐typical features requires an intact nucleus RA, the sexually dimorphic source of the main telencephalic projection to brainstem vocal effectors. We have now made bilateral lesions of RA in 17 adult males and tested their discrimination behavior in the call response situation. Lesioned birds continue to call, but lose the male‐typical preference for female LCs. The degree of loss is correlated with the extent of RA damage. Further, the simplified LCs of males with RA lesions have a variable duration that is correlated with stimulus features. In effect, the call response behavior of lesioned males becomes like that of females. Apparently, in the absence of RA, the remaining intact structures receive different call information than RA normally does, and/or process it differently. This suggests that the vocal motor nucleus RA could play a role in the transformation of a signal encoding the salience of stimulus parameters into a control signal that modulates the probability and strength of responding. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 109–120, 2001
New reproductive anomalies in fruitless‐mutant Drosophila males: Extreme lengthening of mating durations and infertility correlated with defective serotonergic innervation of reproductive organs
Authors: Lee Gyunghee , Villella Adriana , Taylor Barbara J. , Hall Jeffrey C. 
Published: August 2002

AbstractSeveral features of male reproductive behavior are under the neural control of fruitless (fru) in Drosophila melanogaster. This gene is known to influence courtship steps prior to mating, due to the absence of attempted copulation in the behavioral repertoire of most types of fru‐mutant males. However, certain combinations of fru mutations allow for fertility. By analyzing such matings and their consequences, we uncovered two striking defects: mating times up to four times the normal average duration of copulation; and frequent infertility, regardless of the time of mating by a given transheterozygous fru‐mutant male. The lengthened copulation times may be connected with fru‐induced defects in the formation of a male‐specific abdominal muscle. Production of sperm and certain seminal fluid proteins are normal in these fru mutants. However, analysis of postmating qualities of females that copulated with transheterozygous mutants strongly implied defects in the ability of these males to transfer sperm and seminal fluids. Such abnormalities may be associated with certain serotonergic neurons in the abdominal ganglion in which production of 5HT is regulated by fru. These cells send processes to contractile muscles of the male's internal sex organs; such projection patterns are aberrant in the semifertile fru mutants. Therefore, the reproductive functions regulated by fruitless are expanded in their scope, encompassing not only the earliest stages of courtship behavior along with almost all subsequent steps in the behavioral sequence, but also more than one component of the culminating events. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 121–149, 2001
Simulations of flow through fluid/porous layers by a characteristic‐based method on unstructured grids
Authors: Zhang Baili , Zhao Yong 
Published: August 2002

AbstractAn upwind characteristic‐based finite volume method on unstructured grids is employed for numerical simulation of incompressible laminar flow and forced convection heat transfer in 2D channels containing simultaneously fluid layers and fluid‐saturated porous layers. Hydrodynamic and heat transfer results are reported for two configurations: the first one is a backward‐facing step channel with a porous block inserted behind the step, and the second one is a partially porous channel with discrete heat sources on the bottom wall. The effects of Darcy numbers on heat transfer augmentation and pressure loss were investigated for low Reynolds laminar flows. The results demonstrate the accuracy and robustness of the numerical scheme proposed, and suggest that partially porous insertion in a channel can significantly improve heat transfer performance with affordable pressure loss. Copyright © 2001 John Wiley & Sons, Ltd.
Adaptive return mapping algorithms for J2 elasto‐viscoplastic flow
Authors: Lof J. , van den Boogaard A. H. 
Published: August 2002

AbstractIn this paper a new class of integration algorithms for elasto‐viscoplastic constitutive equations is proposed. It is based on the generalized trapezoidal rule, which is a weighted combination of the start and end of the increment. But instead of taking constant weights, the weights are a function of the plastic multiplier. In this way the magnitude of the plastic‐strain increment determines the way the integration is performed. The stress update and consistent tangent are derived for the case of J2 flow. Several candidates within the class of adaptive return mapping algorithms are investigated. It is shown numerically that some of the proposed algorithms are more accurate than commonly used algorithms such as mean normal and radial return. Copyright © 2001 John Wiley & Sons, Ltd.
Boundary elements for half‐space problems via fundamental solutions: A three‐dimensional analysis
Authors: Liang J. , Liew K. M. 
Published: August 2002

AbstractAn efficient solution technique is proposed for the three‐dimensional boundary element modelling of half‐space problems. The proposed technique uses alternative fundamental solutions of the half‐space (Mindlin's solutions for isotropic case) and full‐space (Kelvin's solutions) problems. Three‐dimensional infinite boundary elements are frequently employed when the stresses at the internal points are required to be evaluated. In contrast to the published works, the strongly singular line integrals are avoided in the proposed solution technique, while the discretization of infinite elements is independent of the finite boundary elements. This algorithm also leads to a better numerical accuracy while the computational time is reduced. Illustrative numerical examples for typical isotropic and transversely isotropichalf‐space problems demonstrate the potential applications of the proposed formulations. Incidentally, the results of the illustrative examples also provide a parametric study for the imperfect contact problem. Copyright © 2001 John Wiley & Sons, Ltd.
Topological aspects of meshless methods and nodal ordering for meshless discretizations
Authors: Yavari Arash , Kaveh Ali , Sarkani Shahram , Bondarabady Hosein Ali Rahimi 
Published: August 2002

AbstractThe meshless element‐free Galerkin method (EFGM) is considered and compared to the finite‐element method (FEM). In particular, topological aspects of meshless methods as the nodal connectivity and invertibility of matrices are studied and compared to those of the FE method. We define four associated graphs for meshless discretizations of EFGM and investigate their connectivity. The ways that the associated graphs for coupled FE‐EFG models might be defined are recommended. The associated graphs are used for nodal ordering of meshless models in order to reduce the bandwidth, profile, maximum frontwidth, and root‐mean‐square wavefront of the corresponding matrices. Finally, the associated graphs are numerically compared. Copyright © 2001 John Wiley & Sons, Ltd.
An algebraic two‐level preconditioner for asymmetric, positive‐definite systems
Authors: Giddings Thomas E. , Fish Jacob 
Published: August 2002

AbstractA two‐level, linear algebraic solver for asymmetric, positive‐definite systems is developed using matrices arising from stabilized finite element formulations to motivate the approach. Supported by an analysis of a representative smoother, the parent space is divided into oscillatory and smooth subspaces according to the eigenvectors of the associated normal system. Using a mesh‐based aggregation technique, which relies only on information contained in the matrix, a restriction/prolongation operator is constructed. Various numerical examples, on both structured and unstructured meshes, are performed using the two‐level cycle as the basis for a preconditioner. Results demonstrate the complementarity between the smoother and the coarse‐level correction as well as convergence rates that are nearly independent of the problem size. Copyright © 2001 John Wiley & Sons, Ltd.