bluuebunny/crossref_metadata_2025_split huggingface dataset:
Description of soil anisotropy based on multi‐laminate framework
Authors: Pietruszczak S. , Pande G. N. 
Published: August 2002

AbstractIn this paper, a description of inherent anisotropy of soil, based on multi‐laminate framework, is presented. The problem is formulated by assuming that the conditions at failure are governed by Coulomb criterion in which both the cohesion and the angle of internal friction are functions of the orientation of the sample. The distribution of these parameters is described by employing a set of symmetric second‐order tensors. The formulation of the problem is illustrated by some numerical examples. In particular, the directional dependence of the strength characteristics is examined for samples subjected to both plane strain and triaxial compression. Copyright © 2001 John Wiley & Sons, Ltd.
A new approach to anisotropic, bounding surface plasticity: general formulation and simulations of natural and reconstituted clay behaviour
Authors: Gajo A. , Muir Wood D. 
Published: August 2002

AbstractIt is demonstrated that an efficient framework for the description of a two surface kinematic hardening/bounding surface plasticity model can be devised if the model is conceived in a normalized stress space in which the bounding surface remains of constant size. The hardening of the bounding surface is contained in the transformation laws linking ‘real’ and ‘normalized’ stresses while the geometric rules controlling kinematic hardening are considered only in terms of normalized stresses.Within the general framework thus constructed, two particular models are developed in outline. Owing to the proposed anisotropic hardening, these models are shown to have the ability to reproduce the observed characteristics of the progressive destructuration of natural cemented clays and of the plastic anisotropy of reconstituted soils. Copyright © 2001 John Wiley & Sons, Ltd.
Urge incontinence and impaired detrusor contractility in the elderly
Authors: Griffiths Derek J. , McCracken Peter N. , Harrison Gloria M. , Ann Gormley E. , Moore Katherine N. 
Published: August 2002

AbstractAmong the elderly, both urge incontinence and elevated residual urine are common. When they occur together, they present a challenging clinical problem, called detrusor hyperactivity with impaired contractile function (DHIC). Impaired detrusor contractility has two aspects: elevated post‐void residual urine volume and reduced detrusor contraction strength. Geriatric urge incontinence, especially in combination with reduced bladder sensation, is associated with specific cortical abnormalities: frontal and global cortical underperfusion and cognitive impairment. We have investigated, in 73 elderly incontinent patients, whether either aspect of impaired contractility is associated with urge incontinence, reduced sensation or these cortical abnormalities. For post‐void residual urine, there are no significant associations. Detrusor contraction strength, however, is significantly increased (not impaired) if there is urge incontinence, reduced bladder sensation, or cortical underperfusion. Thus, DHIC appears to be a coincidental occurrence of two common conditions with different etiological factors. Neurourol. Urodynam. 21:126–131, 2002. © 2002 Wiley‐Liss, Inc.
Bladder response to urethral flow in the awake ewe*
Authors: Robain Gilberte , Combrisson Hélène , Mazières Léonor 
Published: August 2002

AbstractThe flowing of fluid along the urethra can facilitate the bladder micturition contraction, a reflex appropriate to achieve complete bladder emptying. The response has been observed in animals studied in the decerebrate, spinal, or anesthetized intact state but is difficult to demonstrate in awake, healthy humans. The aim of this study was to investigate this reflex in the awake, intact state using urodynamics in the ewe. The animals were fully awake and lay gently restrained on a recording table. The bladder was catheterized, and urethral flows were obtained by slowly injecting saline at the level of the proximal urethra. Bladder and rectal pressure were monitored, and the responses to urethral flow were tested at various bladder volumes. Urethral flows consistently evoked detrusor contractions in all animals. The response started approximately 2 seconds after the beginning of the flow and largely outlasted the stimulus. Its amplitude was similar to that of the bladder‐to‐bladder micturition reflex, and, like the latter, it always required some degree of bladder filling to appear. The reflex was selectively suppressed by local anesthesia of the urethral mucosa, indicating that the effect must originate from urethral receptors. Small urethral flows thus appear to elicit large bladder micturition contractions in awake healthy animals, and the reflex could be quite significant during the normal micturition. That this reflex is found in all studied species further supports the notion that the negative results in normal awake humans are owing to descending inhibitory controls rather than to the lack of appropriate pathways. Neurourol. Urodynam. 20:641–649, 2001. © 2001 Wiley‐Liss, Inc.
Urethral instability: Clinical and urodynamic characteristics*
Authors: McLennan Mary T. , Melick Clifford , Bent Alfred E. 
Published: August 2002

AbstractFilling cystometry was performed on 397 patients with lower urinary tract complaints. The overall prevalence of urethral instability was 12.6% (50/397). Of these 187 patients had detrusor instability (DI). Within the DI group, clinical and urodynamic characteristics were compared. Patients with an unstable urethra had a shorter functional urethral length (P = 0.005). For those with DI, 28 of 187 (15%) had urethral instability. Forty (21%) women had a decrease in maximal urethral pressure that preceded the detrusor contraction (type II DI). When those with type II DI were excluded, the difference in functional urethral length was not observed. Patients with type II DI experienced an earlier sensation of fullness of 228 mL compared with 283 mL for the other patients with DI (P = 0.001). There was a positive association between urethral instability and type II DI. Four different patterns of urethral pressure changes were observed. Based on these findings, it appears that a urethral abnormality may be the primary disorder in patients with type II DI. The differentiation of the various subtypes of urethral instability and DI might be important for directing therapy. Neurourol. Urodynam. 20:653–660, 2001. © 2001 Wiley‐Liss, Inc.
Bother arising from urinary frequency in women
Authors: FitzGerald M.P. , Butler N. , Shott S. , Brubaker L. 
Published: August 2002

AbstractPatients commonly express bother with the symptom of frequent urination. The relationship between actual voiding frequency and this symptom is undocumented. We reviewed records of 200 women who had completed 24‐hour frequency‐volume charts, and had indicated their degree of bother with urinary frequency utilizing the short form of the Urogenital Distress Inventory. The degree of bother was correlated with daytime and nighttime voiding frequency, maximum functional capacity, mean voided volume, and demographic variables. Among 200 women, 180 (90%) indicated at least a minor degree of bother with urinary frequency. A voiding frequency of eight or more times in 24 hours was reported by 166 (83%) of women. Among the 34 women voiding fewer than eight times/24 hours, 26 (76%) reported bother with urinary frequency. There was large variation in the degree of bother reported at a given voiding frequency. Postmenopausal women without hormone replacement therapy (HRT) recorded more nighttime voids than those on HRT. Among postmenopausal women without HRT, mean voided volume and maximum functional capacity were inversely related to patient age. Our study suggests that the currently utilized cutoff value of eight daily voids to define urinary frequency, may not be helpful in the management of women in this country. A racially diverse study of the voiding habits of asymptomatic North American women is mandated. Neurourol. Urodynam. 21:36–41, 2002. © 2002 Wiley‐Liss, Inc.
Issues in flow and oxygenation dependent contrast (FLOOD) imaging of tumours
Authors: Howe F. A. , Robinson S. P. , McIntyre D. J. O. , Stubbs M. , Griffiths J. R. 
Published: August 2002

AbstractThe sensitivity of blood oxygenation level dependent (BOLD) contrast techniques to changes to tumour deoxyhaemoglobin concentration is of relevance to many strategies in cancer treatments. In the context of tumour studies, which frequently involve the use of agents to modify blood flow, there are underlying physiological changes different to those of BOLD in the brain. Hence we use the term, flow and oxygenation dependent (FLOOD) contrast, to emphasize this difference and the importance of flow effects. We have measured the R2* changes in a prolactinoma tumour model for a variety of vasoactive challenges [carbogen, 100% oxygen and 100% nitrogen as different breathing gases, and administration of tumour blood flow modifiers such as calcitonin gene related peptide (CGRP), hydralazine and nicotinamide]. In addition we have measured other relevant physiological parameters, such as bioenergetic status from 31P MRS, and blood pH and glucose, that may change during a vasoactive challenge. Here we discuss how they relate to our understanding of FLOOD contrast in tumours. We frequently observe R2* changes that match the expected action of the vascular stimulus: R2* decreases with agents expected to improve tumour oxygenation and blood flow, and increases with agents designed to increase tumour hypoxia. Unlike most normal tissues, tumours have a chaotic and poorly regulated blood supply, and a mix of glycolytic and oxidative metabolism; thus the response to a vasoactive challenge is not predictable. Changes in blood volume can counteract the effect of blood oxygenation changes, and changes in blood pH and glucose levels can alter oxygen extraction. This can lead to R2* changes that are smaller or the reverse of those expected. To properly interpret FLOOD contrast changes these effects must be accounted for. Copyright © 2001 John Wiley & Sons, Ltd.
Non‐invasive measurements of myocardial carbon metabolism using in vivo13C NMR spectroscopy
Authors: Ziegler André , Zaugg Christian E. , Buser Peter T. , Seelig Joachim , Künnecke Basil 
Published: August 2002

AbstractDespite their prime role in maintaining contractile performance, myocardial substrate uptake, substrate preference and metabolism are difficult to assess non‐invasively. The objective of the present work was to extend the scope of cardiac 13C nuclear magnetic resonance (NMR) spectroscopy to the in vivo situation (‘closed‐chest model’) and to quantitatively appraise myocardial metabolism in vivo. For this purpose, overnight‐fasted Sprague–Dawley rats received intravenous infusions of non‐radioactive 13C‐labeled glucose, 3‐hydroxybutyrate, and acetate as markers for glycolysis, metabolism of ketone bodies and direct incorporation into tricarboxylic acid (TCA) cycle, respectively. In vivo 13C NMR spectra (at 7 T) were acquired from the myocardium with a time resolution of 6 min. At the end of the infusion experiments, tissue extracts were prepared and further analyzed by high‐resolution 13C NMR spectroscopy in order to corroborate the findings obtained in vivo. Accordingly, 3‐hydroxybutyrate and acetate were rapidly extracted by the myocardium and supplied 42 ± 6 and 53 ± 9% of the acetyl‐CoA for TCA cycle operation, whereas glucose, although also well extracted, did not contribute to myocardial oxidative metabolism. Myocardial TCA cycle turnover (VTCA) in vivo was estimated at 1.34 ± 0.07 µmol/min/g wet weight, myocardial oxygen consumption (MVO2) at 2.95 ± 0.16 µmol/min/g wet weight, exchange rate between α‐ketoglutarate and glutamate (V
x) at 1.22 ± 0.08 µmol/min/g wet weight and rate of glutamine synthesis (Vgln) at 0.14 ± 0.02 µmol/min/g wet weight. The substantial synthesis of myocardial glutamine is in contrast to experiments with isolated and saline perfused hearts. In conclusion, it is demonstrated that 13C NMR spectroscopy of the heart in intact rats is feasible and provides new quantitative insight into myocardial substrate uptake, preference and metabolism in vivo. Copyright ­© 2002 John Wiley & Sons, Ltd.
Universally maximum flow with piecewise‐constant capacities
Authors: Fleischer Lisa K. 
Published: August 2002

AbstractA maximum flow over time generalizes standard maximum flow by introducing a time component. The object is to send as much flow from source to sink in T time units as possible, where capacities are interpreted as an upper bound on the rate of flow entering an arc. A related problem is the universally maximum flow, which is to send a flow from source to sink that maximizes the amount of flow arriving at the sink by time t simultaneously for all t ≤ T. We consider a further generalization of this problem that allows arc and node capacities to change over time. In particular, given a network with m arcs and n nodes, arc and node capacities that are piecewise constant functions of time with at most k breakpoints and a time bound T, we show how to compute a flow that maximizes the amount of flow reaching the sink in all time intervals (0, t] simultaneously for all 0 < t ≤ T, in O(k2mn log (kn2/m)) time. The best previous algorithm requires O(nk) maximum‐flow computations on a network with m + n)k arcs and nk nodes. Our algorithm improves on this by a factor of O(nk). © 2001 John Wiley & Sons, Inc.
Hydroxyurea‐induced partial mushroom body ablation in the honeybee Apis mellifera: Volumetric analysis and quantitative protein determination
Authors: Malun Dagmar , Plath Niels , Giurfa Martin , Moseleit Ariane D. , Müller Uli 
Published: August 2002

AbstractHydroxyurea (HU) treatment of first instar honeybee larvae was previously shown to cause mushroom body (MB) ablations. Predominantly, either one or both median MB subunits were ablated. This prompted us to analyze the effects of asymmetrical or symmetrical HU‐induced MB ablation on both the morphology of the brain and on the level of three proteins (synapsin, PKA RII, and PKC), which are considered to play a role in synaptic plasticity, learning, and memory. In brains with one median MB subunit missing the volume of the overall MB calyx neuropil in the lesioned side was diminished by 35%. This strong reduction occurred although the remaining lateral MB calyx of the lesioned brain side was found to be significantly larger than that of the intact side. Accordingly, in brains with both median MB subunits missing the size of the remaining lateral calyces increased. The various types of MB ablation differentially affected the amounts of synapsin, PKA RII, and PKC expressed in the central brain. In animals with bilateral and thus symmetrical MB ablation (both median calyces ablated) the protein amount was found to be similar to that in control animals. However, unilateral MB ablation causes an increase in the amounts of the tested proteins in the intact brain side, while the levels in the ablated side were the same as in control animals. These findings not only show that HU‐induced ablation of MB subunits is accompanied by volume changes and by changes in protein expression, but also suggest that these processes are highly regulated between the brain sides. The latter is of general importance in understanding the potential contribution of the MB subunits to learning and memory and their interaction between the brain sides. © 2002 Wiley Periodicals, Inc. J Neurobiol 50: 31–44, 2002
A neuronal inhibitory domain in the N‐terminal half of agrin
Authors: Bixby John L. , Baerwald‐De La Torre Kristine , Wang Cong , Rathjen Fritz G. , Rüegg Markus A. 
Published: August 2002

AbstractAgrin is required for appropriate pre‐ and postsynaptic differentiation of neuromuscular junctions. While agrin's ability to orchestrate postsynaptic differentiation is well documented, more recent experiments have suggested that agrin is also a “stop signal” for the presynaptic neuron, and that agrin has actions on neurons in the CNS. To elucidate the neuronal activities of agrin and to define the receptor(s) responsible for these functions, we have examined adhesions of neurons and their neurite‐outgrowth responses to purified agrin in vitro. We find that both full‐length agrin and the C‐terminal 95 kDa of agrin (agrin c95), which is sufficient to induce postsynaptic differentiation, are adhesive for chick ciliary ganglion (CG) and forebrain neurons. Consistent with previous findings, our results show that N‐CAM binds to full‐length agrin, and suggest that α‐dystroglycan is a neuronal receptor for agrin c95. In neurite outgrowth assays, full‐length agrin inhibited both laminin‐ and N‐cadherin–induced neurite growth from CG neurons. The N‐terminal 150 kDa fragment of agrin, but not agrin c95, inhibited neurite outgrowth, indicating that domains in the N‐terminal portion of agrin are sufficient for this function. Adhesion assays using protein‐coated beads and agrin‐expressing cells revealed differential interactions of agrin with members of the immunoglobulin superfamily of cell adhesion molecules. However, none of these, including N‐CAM, appeared to be critical for neuronal adhesion. In summary, our results suggest that the N‐terminal half of agrin is involved in agrin's ability to inhibit neurite outgrowth. Our results further suggest that neither α‐dystroglycan nor N‐CAM, two known binding proteins for agrin, mediate this effect. © 2002 Wiley Periodicals, Inc. J Neurobiol 50: 164–179, 2002; DOI 10.1002/neu.10025
L1 mediated homophilic binding and neurite outgrowth are modulated by alternative splicing of exon 2
Authors: Jacob Jeffrey , Haspel Jeffrey , Kane‐Goldsmith Noriko , Grumet Martin 
Published: August 2002

AbstractThe neural cell adhesion molecule (CAM) L1 is a member of the immunoglobulin superfamily that has been implicated in neuronal adhesion, neurite outgrowth, and axon guidance. The clinical importance of L1 is illustrated by pathological mutations that lead to hydrocephalus, mental retardation, motor defects, and early mortality. The L1 gene is composed of 28 exons, including exons 2 and 27 that are spliced alternatively, and mutations in exon 2 are associated with severe neurological abnormalities in humans. To elucidate the role of L1 exon 2, a recombinant Fc fusion protein called Δ2L1 was constructed lacking the second exon in the extracellular domain of L1. When bound to fluorescent beads, L1 exhibited homophilic binding while Δ2L1 did not. However, L1 beads coaggregated with the Δ2L1 beads. Similarly, in cell binding studies, L1 bound to L1 and Δ2L1 did not bind to Δ2L1 but it bound moderately to L1. Given the reduced binding of Δ2L1, we tested its effect on neurons. By comparison to L1, a lower percentage of dissociated neurons extended neurites on Δ2L1, and there was a modest decrease in the length of the neurites that grew. Neurite outgrowth from reaggregated neurons was much less robust on Δ2L1 than on L1. The combined results indicate that Δ2L1 does not bind homophilically but it can interact with L1 containing exon 2. The reduced binding and neurite promoting activity of Δ2L1 provides an explanation for certain pathological mutations in L1 that lead to clinically apparent disease in the absence of the normal form of L1 in the nervous system. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 237–247, 2002
Transient waves in plates of functionally graded materials
Authors: Han X. , Liu G. R. , Lam K. Y. 
Published: August 2002

AbstractA numerical method is proposed for analysing transient waves in plates of functionally graded material (FGM) excited by impact loads. The material properties of the FGM plate have a gradient in the thickness direction and are anisotropic in the plane of the plate. In the present method, the FGM plate is divided into layer elements in the thickness direction. For an accurate modelling of the variation of the material property of FGM plates, it is expressed by second‐order polynomials in the thickness direction within an element. This can further reduce the number of elements to obtain more accurate results effectively. The principle of virtual work is used to develop approximate dynamic equilibrium equations. The displacement response is determined by employing the Fourier transformation and the modal analysis. As examples, the displacement response of FGM plates excited by line, point and distributed loads is calculated. The computations have shown the efficiency of the present method. Copyright © 2001 John Wiley & Sons, Ltd.
Microplane finite element analysis of tube‐squash test of concrete with shear angles up to 70°
Authors: Brocca Michele , Bažant Zdeněk P. 
Published: August 2002

AbstractFinite element analysis of the response of concrete structures to impact events such as missile penetration, explosive driving of anchors, blast, ground shock or seismic loading, requires knowledge of the stress–strain relations for concrete for finite strain at high pressures. A novel type of material test achieving very large shear angles of concrete at very large pressures, called the tube‐squash test, can be used to calibrate a concrete model taking into account plastic deformation at extreme pressures. A finite element analysis of such a test is performed by using a finite strain generalization of microplane models for concrete and steel. The results obtained are in good agreement with those previously obtained with a simplified method of analysis. Thus, they provide a validation of the microplane model, which is shown to be capable of reproducing the response of concrete not only for small strains at small pressures, which is predominantly brittle, but also for high pressures and large finite strains, which is predominantly frictional plastic. Copyright © 2001 John Wiley & Sons, Ltd.
A Framework for Successful E‐Technology Implementation: Understand, Simplify, Automate
Authors: Kapp Karl M. 
Published: August 2002

AbstractToo many computerized systems are still not designed to best meet the business needs of their end‐users.
Often, the reason is that non‐technology managers do not take an active enough part in the design of those
systems. But those who follow the three‐step process of understanding, simplifying, and only then automating
will work most effectively with their information systems colleagues to design the most appropriate systems.
© 2001 John Wiley & Sons, Inc.
Glutamate neurotoxicity does not modify aminopeptidase activities in mouse brain homogenates
Authors: Ramírez‐Expósito María Jesús , Mayas María Dolores , García María Jesús , Ramírez Manuel , Martínez‐Martos José Manuel 
Published: August 2002

AbstractGlutamate is the principal excitatory neurotransmitter in the brain, playing an important role in several physiological neuronal activities. When excessive glutamate is released, a cascade of events causes the formation of free radicals. The central nervous system is particularly vulnerable to free radical damage, due to free radicals induce membrane lipids peroxidation. Aminopeptidases are enzymes implicated in the regulation of several biologically active peptides. In the present study, we have investigated if glutamate excitotoxicity, under conditions that induce lipid peroxidation, lead to aminopeptidases misregulation. We conclude that aminopeptidase activities are not altered by the characteristic neurodegeneration and excitotoxicity associated with glutamate.
Healed trauma in an early Bronze Age human skeleton from Buckinghamshire, England
Authors: Anderson T. 
Published: August 2002

AbstractAn adult male from a multiple burial at the centre of an early Bronze Age barrow displays a healed fracture of the tibial condyle. Apparently, this is the first reported evidence for this type of fracture in British archaeological material. It provides evidence for care and compassion in the prehistoric period. Also, it apparently indicates that high social status could be retained by an individual who was suffering from a physical incapacity. Copyright © 2002 John Wiley & Sons, Ltd.