bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proteoglycan‐induced changes in T1ρ‐relaxation of articular cartilage at 4T
Authors: Akella Sarma V.S. , Reddy Regatte Ravinder , Gougoutas Alexander J. , Borthakur Arijitt , Shapiro Erik M. , Kneeland J. Bruce , Leigh John S. , Reddy Ravinder 
Published: August 2002

AbstractProteoglycan (PG) depletion‐induced changes in T1ρ (spin‐lattice relaxation in rotating frame) relaxation and dispersion in articular cartilage were studied at 4T. Using a spin‐lock cluster pre‐encoded fast spin echo sequence, T1ρ maps of healthy bovine specimens and specimens that were subjected to PG depletion were computed at varying spin‐lock frequencies. Sequential PG depletion was induced by trypsinization of cartilage for varying amounts of time. Results demonstrated that over 50% depletion of PG from bovine articular cartilage resulted in average T1ρ increases from 110–170 ms. Regression analysis of the data showed a strong correlation (R2 = 0.987) between changes in PG and T1ρ. T1ρ values were highest at the superficial zone and decreased gradually in the middle zone and again showed an increasing trend in the region near the subchondral bone. The potentials of this method in detecting early degenerative changes of cartilage are discussed. Also, T1ρ‐dispersion changes as a function of PG depletion are described. Magn Reson Med 46:419–423, 2001. © 2001 Wiley‐Liss, Inc.
Mixed echo train acquisition displacement encoding with stimulated echoes: An optimized DENSE method for in vivo functional imaging of the human heart
Authors: Aletras Anthony H. , Wen Han 
Published: August 2002

AbstractMixedechotrainacquisitiondisplacementencoding withstimulatedechoes (meta‐DENSE) is a phase‐based displacement mapping technique suitable for imaging myocardial function. This method has been optimized for use with patients who have a history of myocardial infarction. The total scan time is 12–14 heartbeats for an in‐plane resolution of 2.8 × 2.8 mm2. Myocardial strain is mapped at this resolution with an accuracy of 2% strain in vivo. Compared to standardstimulatedecho (STE) methods, both data acquisition speed and resolution are improved with inversion‐recovery FID suppression and the meta‐DENSE readout scheme. Data processing requires minimal user intervention and provides a rapid quantitative feedback on the MRI scanner for evaluating cardiac function. Magn Reson Med 46:523–534, 2001. Published 2001 Wiley‐Liss, Inc.
Two‐dimensional time correlation relaxometry of skeletal muscle in vivo at 3 Tesla
Authors: Saab George , Thompson R. Terry , Marsh Gregory D. , Picot Paul A. , Moran Gerald R. 
Published: August 2002

AbstractA hybrid two‐dimensional relaxometry (2DR) sequence was used to simultaneously measure both the spin‐spin (R2) and spin‐lattice relaxation rates (R1) of skeletal muscle in vivo. The 2DR sequence involved a 180° inversion pulse followed by a variable delay time (30 values from 40 to 7000 ms); a projection presaturation (PP) scheme to localize a 16‐ml cylindrical voxel; and a CPMG sequence (950 even echoes, effective echo spacing = 1.2 ms, equilibrium time = 12 s). The 2DR data were collected at 3.0 Tesla from the flexor digitorum profundus of eight healthy males, 26 ± 2 years old. Analysis was performed with a 2D version of the non‐negative least‐squares algorithm and a one‐way ANOVA. All subjects exhibited at least three spin‐groups (R2 < 200 s−1), designated B, C, and D, with R2 values of 42.7, 26.5, and 8.1 s−1, and fractional volumes of 52, 35, and 7%, respectively. The R1 values of B and C were similar, ≅0.7 s−1, but different from that of D (P < 0.001), which had an R1 of 1.0 s−1. The results suggest that exchange between B and C ranges from 0.7–16.2 s−1, while exchange between either of these spin‐groups with D is slower. If the data are interpreted with a compartment model, in which spin‐groups with short and long R2 values are attributed to extra‐ and intracellular fluid, respectively, the exchange of water across the cell membrane in living skeletal muscle is slow or intermediate relative to both R1 and R2. Magn Reson Med 46:1093–1098, 2001. © 2001 Wiley‐Liss, Inc.
Motor unit number estimation in infants and children with spinal muscular atrophy
Authors: Bromberg Mark B. , Swoboda Kathryn J. 
Published: August 2002

AbstractSpinal muscular atrophy (SMA) is a disease of lower motor neurons. Motor unit number estimation (MUNE) is an electrophysiologic method to estimate the number of motor neurons innervating a muscle group. We applied the multiple point stimulation technique to the ulnar nerve–hypothenar muscle group to study lower motor neuron loss in 14 SMA subjects, including those presymptomatic, and varying from newborn through 45 years of age. Preliminary data support the value of MUNE to help understand the time course of motor neuron loss in SMA. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
Postexercise facilitation of motor evoked potentials following transcranial magnetic stimulation: A study in normal subjects
Authors: Balbi Pietro , Perretti Anna , Sannino Marilena , Marcantonio Lucia , Santoro Lucio 
Published: August 2002

AbstractThe size of the motor evoked potential (MEP) elicited by transcranial magnetic stimulation increases soon after a nonexhaustive voluntary contraction of the target muscle (postexercise facilitation). Our aim was to determine whether the duration or intensity of voluntary muscle contraction influenced postexercise facilitation in normal subjects. We recorded the MEP from the thenar muscles following contractions of different durations (5, 15, and 30 s) and intensities (10%, 25%, and 50% of maximal voluntary contraction). We found that every combination of the tested intensities and durations of physical effort could induce postexercise MEP facilitation. Although the degree of postexercise MEP facilitation was comparable across the different durations and intensities, the maximal facilitation was observed with the shortest and strongest muscle contraction. Our study thus defines the optimal setting to study postexercise facilitation for clinical purposes. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
Parameters for monitoring treatment effects in CIDP with anti‐MAG/SGPG IgM antibody
Authors: Tagawa Yumi , Yuki Nobuhiro , Ohnishi Akio , Hirata Koichi , Hosokawa Shinichi 
Published: August 2002

AbstractWe used cycles of plasma exchange and intravenous cyclophosphamide to treat a patient who had chronic inflammatory demyelinating polyneuropathy with anti–myelin‐associated glycoprotein/sulfoglucuronylparagloboside IgM antibody. After treatment, serum anti‐sulfoglucuronylparagloboside IgM antibody titers were reduced significantly, and clear symptomatic improvement followed. The percentage of CD57‐positive lymphocytes and natural killer cell activity had also returned to normal. Our findings indicate that serial measurements of these parameters are useful for monitoring treatment effect in this disease. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 701–704, 2001
Maximal exercise and muscle energy metabolism after recovery from exercise hyperthermia syndrome
Authors: Vanuxem P. , Vanuxem D. , Raharison L. , Aubert M. , Pouliquen G. , Deslangles O. 
Published: August 2002

AbstractMuscle energy metabolism was studied in 30 subjects after recovery from exercise hyperthermia syndrome (EHTS subjects) and 15 healthy men with identical physical activities. Blood lactate, free fatty acid (FFA), serum creatine kinase activity (CK), and glycerol and the temperature in the auditory duct (Tc) and on the thumb pad (Tsk) were measured at rest and during and after maximal exercise on a cycloergometer. The EHTS subjects had a limitation of physical performance, with lowered values for maximal oxygen uptake (VO2max, P < 0.0005), maximal workload (P < 0.05), and ventilatory threshold (Vt, P < 0.0005). The discrepancy between high plasma concentrations of FFA and the lack of decrease in respiratory ratio (RR) suggests that, in EHTS subjects, a very active release of FFA was not balanced by a proportional increase in catabolism. The increased skin temperature was smaller in EHTS subjects (P < 0.05 at 180 and 200 W). At the end of exercise, auditory duct temperature increase was higher in EHTS subjects than in control subjects (P < 0.05). This study thus showed an impairment of muscle metabolism and an abnormality of thermoregulatory mechanisms. These results may provide insight into the underlying physiopathological disturbance. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1071–1077, 2001
Simulating the collapse of unsaturated soil by DEM
Authors: Liu S. H. , Sun D. A. 
Published: August 2002

AbstractThis paper presents a numerical method to simulate the collapse behaviours of unsaturated soils by distinct element method (DEM). The influence of suction in unsaturated soil is reproduced in DEM simulation by introducing an interparticle adhesive force that acts perpendicular to the tangential plane at contact point. A biaxial compression test on an assembly of circular rigid particles is numerically simulated using DEM by incorporating interparticle adhesive forces. The collapse behaviours of unsaturated soils during isotropic compression and biaxial shear are simulated by means of releasing the interparticle adhesive forces from the initially incorporated values to zero at constant stress state. The numerically simulated results are then compared with the results of triaxial compression tests on unsaturated compacted clays and qualitative similarities are obtained. The influences of the mean stress, the stress ratio and the interparticle adhesive force on the collapse behaviours are numerically investigated. The fabric structure and the particle stability of the simulated specimen before and after collapse are also investigated and discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Rendezvous of three agents on the line
Authors: Alpern Steve , Lim Wei Shi 
Published: August 2002

AbstractThis paper considers a three‐person rendezvous problem on the line which was introduced earlier by the authors. Three agents are placed at three consecutive integer value points on the real line, say 1, 2, and 3. Each agent is randomly faced towards the right or left. Agents are blind and have a maximum speed of 1. Their common aim is to gather at a common location as quickly as possible. The main result is the proof that a strategy given by V. Baston is the unique minimax strategy. Baston's strategy ensures a three way rendezvous in time at most 3.5 for any of the 3!23 = 48 possible initial configurations corresponding to positions and directions of each agent. A connection is established between the above rendezvous problem and a search problem of L. Thomas in which two parents search separately to find their lost child and then meet again. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 244–255, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10005
High‐resolution BOLD venographic imaging: a window into brain function
Authors: Reichenbach Jürgen R. , Haacke E. Mark 
Published: August 2002

AbstractThis paper reviews the recent development of a new high‐resolution magnetic resonance imaging approach to visualizing small veins in the human brain with diameters in the sub‐millimeter range, which is smaller than a voxel. It briefly introduces the physical background of the underlying bulk magnetic susceptibility effects, on which this approach is based, and it demonstrates the successful application of the method for imaging different intracranial lesions, like venous anomalies, arteriovenous malformations and brain tumors. The susceptibility difference between venous blood and the surrounding tissue is used to generate contrast. Using this method it is possible to visualize draining veins in lesions better than conventional magnetic resonance imaging methods, which often require application of a contrast medium or even conventional catheter angiography. Limitations of the method are discussed. The ability to highlight deoxygenated blood with high spatial resolution yields important vascular parameters which may be helpful for improved modeling of MR signal changes during functional brain activation, it may lead to a better understanding of brain function in diseased states, or it may even offer the possibility of differentiating benign from malignant tumors non‐invasively. Copyright © 2001 John Wiley & Sons, Ltd.
Characterization of BOLD activation in multi‐echo fMRI data using fuzzy cluster analysis and a comparison with quantitative modeling
Authors: Barth Markus , Windischberger Christian , Klarhöfer Markus , Moser Ewald 
Published: August 2002

AbstractA combination of multiple gradient‐echo imaging and exploratory data analysis (EDA), i.e. fuzzy cluster analysis (FCA), is proposed for separation and characterization of BOLD activation in single‐shot spiral functional magnetic resonance imaging (fMRI) experiments at 3 T. Differentiation of functional activation using FCA is performed by clustering pixel signal changes (ΔS) as a function of echo time (TE). Further vascular classification is supported by the localization of activation and the comparison with a single‐exponential decay model. In some subjects, an additional indication for large vessels within a voxel was found as oscillation of the fMRI signal difference vs echo time (TE). Such large vessels may be separated from small vessel activation and, therefore, our proposed procedure might prove useful if a more specific functional localization is desired in fMRI. In addition to the signal change ΔS, ΔT2*/T2* is significantly different between activated regions. Averaged over all eight subjects ΔT2* is 1.7 ± 0.2 ms in ROIs with the highest signal change characterized as containing large vessels, whereas in ROIs corresponding to microvascular environment average ΔT2* values are 0.8 ± 0.1 ms. Copyright © 2001 John Wiley & Sons, Ltd.
Superconnected digraphs and graphs with small conditional diameters
Authors: Balbuena C. , Fàbrega J. , Marcote X. , Pelayo I. 
Published: August 2002

AbstractThe conditional diameter Dν of a digraph G measures how far apart a pair of vertex sets V1 and V2 can be in such a way that the minimum out‐degree and the minimum in‐degree of the subdigraphs induced by V1 and V2, respectively, are at least ν. Thus, D0 is the standard diameter and D0 ≥ D1 ≥ ··· ≥ Dδ, where δ is the minimum degree. We prove that if Dν ≤ 2l − 3, where l is a parameter related to the shortest paths, then G is maximally connected, is superconnected, or has a good superconnectivity, depending only on whether ν is equal to ⌈δ/2⌉, ⌈(δ − 1)/2⌉, or ⌈(δ − 1)/3⌉, respectively. In the edge case, it is enough that Dν ≤ 2l − 2. The results for graphs are obtained as a corollary of those for digraphs, because, in the undirected case, l = ⌊(g − 1)/2⌋, g being the girth. © 2002 Wiley Periodicals, Inc.
A CUB‐serine protease in the olfactory organ of the spiny lobster Panulirus argus
Authors: Levine Min Z. , Harrison Paul J. H. , Walthall W. William , Tai Phang C. , Derby Charles D. 
Published: August 2002

Abstractcsp, a gene encoding a protein with high sequence identity to trypsinlike serine protease and CUB domains, was identified from a cDNA library from the olfactory organ (antennular lateral flagellum) of the spiny lobster Panulirus argus. The full‐length cDNA sequence of csp is 1801 bp, encoding a protein of 50.25 kD, with three domains: signal peptide, trypsinlike serine protease, and CUB (named for a class of compounds including Complement subcomponents Clr/Cls, Uegf, and Bone morphogenic protein‐1). RT‐PCR, Northern blots, and immunoblots showed that csp is predominantly expressed in the lateral flagellum and eyestalk. Immunocytochemistry showed that Csp is present in olfactory (aesthetasc) sensilla around auxiliary cells (glia that surround the inner dendrites of olfactory receptor neurons, ORNs) and ORN outer dendrites. We propose that Csp is expressed and secreted by auxiliary cells, associates with ORN cell membranes or extracellular matrix via the CUB domain, and has trypsinlike activity. In the eyestalk, Csp is associated with cells surrounding axons between neuropils of the eyestalk ganglia. Possible functions in the olfactory organ and eyestalk are discussed. To our knowledge, this is the first report from any olfactory system of a gene encoding a protein with serine protease and CUB domains. © 2001 John Wiley & Sons, Inc. J Neurobiol 49: 277–302, 2001
Changes in spatial memory mediated by experimental variation in food supply do not affect hippocampal anatomy in mountain chickadees (Poecile gambeli)
Authors: Pravosudov V. V. , Lavenex P. , Clayton N. S. 
Published: August 2002

AbstractEarlier reports suggested that seasonal variation in food‐caching behavior (caching intensity and cache retrieval accuracy) might correlate with morphological changes in the hippocampal formation, a brain structure thought to play a role in remembering cache locations. We demonstrated that changes in cache retrieval accuracy can also be triggered by experimental variation in food supply: captive mountain chickadees (Poecile gambeli) maintained on limited and unpredictable food supply were more accurate at recovering their caches and performed better on spatial memory tests than birds maintained on ad libitum food. In this study, we investigated whether these two treatment groups also differed in the volume and neuron number of the hippocampal formation. If variation in memory for food caches correlates with hippocampal size, then our birds with enhanced cache recovery and spatial memory performance should have larger hippocampal volumes and total neuron numbers. Contrary to this prediction we found no significant differences in volume or total neuron number of the hippocampal formation between the two treatment groups. Our results therefore indicate that changes in food‐caching behavior and spatial memory performance, as mediated by experimental variations in food supply, are not necessarily accompanied by morphological changes in volume or neuron number of the hippocampal formation in fully developed, experienced food‐caching birds. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 142–148, 2002
Inactivation of olfactory sensilla of a single morphological type differentially affects the response of Drosophila to odors
Authors: Park S.‐K. , Shanbhag S.R. , Dubin A.E. , de Bruyne M. , Wang Q. , Yu P. , Shimoni N. , D'Mello S. , Carlson J.R. , Harris G.L. , Steinbrecht R.A. , Pikielny C.W. 
Published: August 2002

AbstractThe olfactory organs on the head of Drosophila, antennae and maxillary palps, contain several hundred olfactory hairs, each with one or more olfactory receptor neurons. Olfactory hairs belong to one of three main morphological types, trichoid, basiconic, and coeloconic sensilla, and show characteristic spatial distribution patterns on the surface of the antenna and maxillary palps. Here we show that targeting expression of the cell‐death gene reaper to basiconic sensilla (BS) causes the specific inactivation of most olfactory sensilla of this type with no detectable effect on other types of olfactory sensilla or the structure of the antennal lobe. Our data suggest that BS are required for a normal sensitivity to many odorants with a variety of chemical structures, through a wide range of concentrations. Interestingly, however, in contrast to other odorants tested, the behavioral response of ablated flies to intermediate concentrations of propionic and butyric acids is normal, suggesting the involvement of sensilla unaffected by ectopic reaper expression, probably coeloconic sensilla that respond strongly to these two organic acids. As inactivation of BS causes an underestimation of the concentration of both acids detectable at both the highest and lowest odorants concentrations, our results suggest that concentration coding for these two odorants relies on the integration of signals from different subsets of sensilla, most likely of different morphological types.
Local preconditioners for two‐level non‐overlapping domain decomposition methods
Authors: Carvalho L. M. , Giraud L. , Meurant G. 
Published: August 2002

AbstractWe consider additive two‐level preconditioners, with a local and a global component, for the Schur complement system arising in non‐overlapping domain decomposition methods. We propose two new parallelizable local preconditioners. The first one is a computationally cheap but numerically relevant alternative to the classical block Jacobi preconditioner. The second one exploits all the information from the local Schur complement matrices and demonstrates an attractive numerical behaviour on heterogeneous and anisotropic problems. We also propose two implementations based on approximate Schur complement matrices that are cheaper alternatives to construct the given preconditioners but that preserve their good numerical behaviour. Through extensive computational experiments we study the numerical scalability and the robustness of the proposed preconditioners and compare their numerical performance with well‐known robust preconditioners such as BPS and the balancing Neumann–Neumann method. Finally, we describe a parallel implementation on distributed memory computers of some of the proposed techniques and report parallel performances. Copyright © 2001 John Wiley & Sons, Ltd.
On convergence of SOR methods for nonsmooth equations
Authors: Chen Xiaojun 
Published: August 2002

AbstractWe study the choice of relaxation parameters ω for convergence of the SOR Newton method and the SOR method for the system of equations F(x)=0 in a unified framework, where F is strongly monotone, locally Lipschitz continuous but not necessarily differentiable. Applications to non‐smooth Dirichlet problems are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
The generalized differential quadrature rule for fourth‐order differential equations
Authors: Wu T. Y. , Liu G. R. 
Published: August 2002

AbstractThe generalized differential quadrature rule (GDQR) proposed here is aimed at solving high‐order differential equations. The improved approach is completely exempted from the use of the existing δ‐point technique by applying multiple conditions in a rigorous manner. The GDQR is used here to static and dynamic analyses of Bernoulli–Euler beams and classical rectangular plates. Numerical error analysis caused by the method itself is carried out in the beam analysis. Independent variables for the plate are first defined. The explicit weighting coefficients are derived for a fourth‐order differential equation with two conditions at two different points. It is quite evident that the GDQR expressions and weighting coefficients for two‐dimensional problems are not a direct application of those for one‐dimensional problems. The GDQR are implemented through a number of examples. Good results are obtained in this work. Copyright © 2001 John Wiley & Sons, Ltd.
Edge‐based finite element techniques for non‐linear solid mechanics problems
Authors: Coutinho Alvaro L. G. A. , Martins Marcos A. D. , Alves José L. D. , Landau Luiz , Moraes Anderson 
Published: August 2002

AbstractEdge‐based data structures are used to improve computational efficiency of inexact Newton methods for solving finite element non‐linear solid mechanics problems on unstructured meshes. Edge‐based data structures are employed to store the stiffness matrix coefficients and to compute sparse matrix–vector products needed in the inner iterative driver of the inexact Newton method. Numerical experiments on three‐dimensional plasticity problems have shown that memory and computer time are reduced, respectively, by factors of 4 and 6, compared with solutions using element‐by‐element storage and matrix–vector products. Copyright © 2001 John Wiley & Sons, Ltd.