bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real‐scale miscible grout injection experiment and performance of advection–dispersion–filtration model
Authors: Bouchelaghem F. , Vulliet L. , Leroy D. , Laloui L. , Descoeudres F. 
Published: August 2002

AbstractA model was developed, to describe miscible grout propagation in a saturated deformable porous medium, based on Bear's statistical model with spatial volume averaging. In a previous paper, the model was first successfully confronted to one‐dimensional laboratory experiments.In the present paper, the numerical model is used to simulate practical grouting operation in a cylindrical injection model. The cylindrical injection model lends itself to study main flow and propagation character istics for a dispersed suspension‐type grout, under axisymmetric conditions close to real scale conditions.Comparison between numerical solutions and experimental results is essential to confirm the validity and accuracy of the proposed model from a phenomenological standpoint. The numerical model performances show that the underlying mathematical model constitutes a realistic predictive model reproducing most prominent features during injection of a suspension‐type grout into a deformable porous medium. The basic mechanism by which injected miscible grout permeates a soil mass is discussed in detail. Such a tool leads to quality control criteria for grouting on a theoretical basis, which complements existing criteria acquired through engineering practice. Copyright © 2001 John Wiley & Sons, Ltd.
Self‐similar solution of a plane‐strain fracture driven by a power‐law fluid
Authors: Adachi J. I. , Detournay E. 
Published: August 2002

AbstractThis paper analyses the problem of a hydraulically driven fracture, propagating in an impermeable, linear elastic medium. The fracture is driven by injection of an incompressible, viscous fluid with power‐law rheology and behaviour index n⩾0. The opening of the fracture and the internal fluid pressure are related through the elastic singular integral equation, and the flow of fluid inside the crack is modelled using the lubrication theory. Under the additional assumptions of negligible toughness and no lag between the fluid front and the crack tip, the problem is reduced to self‐similar form. A solution that describes the crack length evolution, the fracture opening, the net fluid pressure and the fluid flow rate inside the crack is presented. This self‐similar solution is obtained by expanding the fracture opening in a series of Gegenbauer polynomials, with the series coefficients calculated using a numerical minimization procedure. The influence of the fluid index n in the crack propagation is also analysed. Copyright © 2002 John Wiley & Sons, Ltd.
Involuntary detrusor contractions: Correlation of urodynamic data to clinical categories
Authors: Romanzi Lauri J. , Groutz Asnat , Heritz Dianne M. , Blaivas Jerry G. 
Published: August 2002

AbstractData regarding the prevalence and urodynamic characteristics of involuntary detrusor contractions (IDC) in various clinical settings, as well as in neurologically intact vs. neurologically impaired patients, are scarce. The aim of our study was to evaluate whether the urodynamic characteristics of IDC differ in various clinical categories. One hundred eleven consecutive neurologically intact patients and 21 consecutive neurologically impaired patients, referred for evaluation of persistent irritative voiding symptoms, were prospectively enrolled. All patients were presumed by history to have IDC, and underwent detailed clinical and urodynamic evaluation. Based on clinical evaluation, patients were placed into one of four categories according to the main presenting symptoms and the existence of neurological insult: 1) frequency/urgency; 2) urge incontinence; 3) mixed stress incontinence and irritative symptoms; and 4) neurogenic bladder. IDC was defined by detrusor pressure of ≥ 15 cm H2O whether or not the patient perceived the contraction; or < 15 cm H2O if perceived by the patient. Eight urodynamic characteristics of IDC were analyzed and compared between the four groups. IDC were observed in all of the neurologically impaired patients, compared with 76% of the neurologically intact patients (P < 0.001). No correlation was found between amplitude of IDC and subjective report of urgency. All clinical categories demonstrated IDC at approximately 80% of cystometric capacity. Eighty‐one percent of the neurologically impaired patients, compared with 97% of the neurologically intact patients, were aware of the IDC at the time of urodynamics (P < 0.04). The ability to abort the IDC was significantly higher among continent patients with frequency/urgency (77%) compared with urge incontinent patients (46%) and neurologically impaired patients (38%). In conclusion, when evaluating detrusor overactivity, the characteristics of the IDC are not distinct enough to aid in differential diagnosis. However, the ability to abort IDC and stop incontinent flow may have prognostic implications, especially for the response to behavior modification, biofeedback, and pelvic floor exercise. Neurourol. Urodynam. 20:249–257, 2001. © 2001 Wiley‐Liss, Inc.
Urodynamic follow‐up of experimental urethral obstruction in individual guinea pigs
Authors: Wolffenbuttel K.P. , Kok D.J. , Minekus J.P.J. , van Koeveringe G.A. , van Mastrigt R. , Nijman J.M. 
Published: August 2002

AbstractIt is unknown whether changes in bladder function due to urethral obstruction follow a specific sequence. To answer this, we adapted a small animal model to allow repeated complete pressure‐flow studies, enabling individual follow‐up of changes in bladder function on urethral obstruction. Obstruction was induced in guinea pigs by placing a silver ring around the urethra. Urodynamic studies were repeated under anesthesia with ketamine/xylazine. Bladders were filled and bladder pressure measured through a single suprapubic catheter. Urine flow rate was measured using an ultrasound probe around the penis. Accurate measurements of bladder pressure and urine flow rates were obtained at 1‐week intervals for 11 weeks in individual guinea pigs. In the control animals, the urodynamic parameters did not show significant changes. In the obstructed group, urethral resistance (Plow,ave) increased from 20 to 35 cm H2O after 4 weeks and remained at that level. The maximum flow rate (Qmax) increased from 0.17 to 0.24 mL/s after 2 to 3 weeks. After this peak, it gradually decreased to lower than the starting value after 10 to 11 weeks. The pressure at maximum flow rate (pQmax) increased from 24 to 47 cm H2O after 6 to 7 weeks and thereafter declined. During weeks 1 through 4 of obstruction, unstable contractions were seen. All animals followed a similar sequence of patterns but at variable rates. Our animal model allows complete urodynamic follow‐up of individual animals with urethral obstruction. We observed a specific sequence of changes in urodynamic patterns and parameters of bladder function. Neurourol. Urodynam. 20:699–713, 2001. © 2001 Wiley‐Liss, Inc.
Physiologic bladder evacuation with selective sacral root stimulation: Sinusoidal signal and organ‐specific frequency
Authors: Sievert Karl‐Dietrich , Gleason Curtis A. , Jünemann Klaus‐Peter , Alken Peter , Tanagho Emil A. 
Published: August 2002

AbstractIn patients with spinal cord injury above S2, who characteristically have both detrusor hyperflexia and sphincteric spasm, sacral anterior root stimulation can evacuate the bladder, but sacral deafferentation is needed to eliminate the hyperreflexia for normal bladder filling. The common stimulation parameters for these patients activate the detrusor and the external urethral sphincter simultaneously (detrusor‐sphincter dyssynergia), and the resultant post‐stimulus voiding is not physiologic. We sought to determine organ‐specific stimulation parameters. In 20 male dogs, the rectangular pulse and sinusoidal signal forms were evaluated with a variety of parameters for stimulation of S2 and S3 anterior roots extra‐ and intradurally (i.e., stimulation frequency and voltage, uni‐ versus bilateral electrode placement, and degree of bladder filling). New torpedo‐shaped bipolar electrodes were used, adjusted to neural diameter. The best results were recorded with intradural bilateral sinusoidal signal. Sphincteric fatigue was produced by pre‐stimulating S2 with 104 ± 17 Hz and 0.8 ± 0.1 V for 10 to 15 seconds before S3 stimulation. S3 stimulation with 16 ±  2.1 Hz and 0.4 ± 0.1 V evoked a detrusor pressure of 28.7 ± 3.0 cm H2O above the sphincteric pressure. Selective anterior root stimulation with organ‐specific stimulation parameters can effect initial sphincteric fatigue to achieve physiologic voiding. Neurourol. Urodynam. 21:80–91, 2002. © 2002 Wiley‐Liss, Inc.
The organization of synaptic vesicles at tonically transmitting connections of locust visual interneurons
Authors: Leitinger Gerd , Simmons Peter J. 
Published: August 2002

AbstractLarge, second‐order neurons of locust ocelli, or L‐neurons, make some output connections that transmit small changes in membrane potential and can sustain transmission tonically. The synaptic connections are made from the axons of L‐neurons in the lateral ocellar tracts, and are characterized by bar‐shaped presynaptic densities and densely packed clouds of vesicles near to the cell membrane. A cloud of vesicles can extend much of the length of this synaptic zone, and there is no border between the vesicles that are associated with neighboring presynaptic densities. In some axons, presynaptic densities are associated with discrete small clusters of vesicles. Up to 6% of the volume of a length of axon in a synaptic zone can be occupied with a vesicle cloud, packed with 4.5 to 5.5 thousand vesicles per μm3. Presynaptic densities vary in length, from less than 70 nm to 1.5 μm, with shorter presynaptic densities being most frequent. The distribution of vesicles around short presynaptic densities was indistinguishable from that around long presynaptic densities, and vesicles were distributed in a similar way right along the length of a presynaptic density. Within the cytoplasm, vesicles are homogeneously distributed within a cloud. We found no differences in the distribution of vesicles in clouds between locusts that had been dark‐adapted and locusts that had been light‐adapted before fixation. © 2002 Wiley Periodicals, Inc. J Neurobiol 50: 93–105, 2002; DOI 10.1002/neu.10018
A survey of spectral factorization methods
Authors: Sayed A. H. , Kailath T. 
Published: August 2002

AbstractSpectral factorization is a crucial step in the solution of linear quadratic estimation and control problems. It is no wonder that a variety of methods has been developed over the years for the computation of canonical spectral factors. This paper provides a survey of several of these methods with special emphasis on clarifying the connections that exist among them. While the discussion focuses primarily on scalar‐valued rational spectra, extensions to non‐rational and vector‐valued spectra are briefly noted. Copyright © 2001 John Wiley & Sons, Ltd.
The effect of overall discretization scheme on Jacobian structure, convergence rate, and solution accuracy within the local rectangular refinement method
Authors: Bennett Beth Anne V. , Smooke Mitchell D. 
Published: August 2002

AbstractThe local rectangular refinement (LRR) solution‐adaptive gridding method automatically produces orthogonal unstructured adaptive grids and incorporates multiple‐scale finite differences to discretize systems of elliptic governing partial differential equations (PDEs). The coupled non‐linear discretized equations are solved simultaneously via Newton's method with a Bi‐CGSTAB linear system solver. The grids' unstructured nature produces a nonstandard sparsity pattern within the Jacobian.The effects of two discretization schemes (LRR multiple‐scale stencils and traditional single‐scale stencils) on Jacobian bandwidth, convergence speed, and solution accuracy are studied. With various point orderings, for two simple problems with analytical solutions, the LRR multiple‐scale stencils are seen to: (1) produce Jacobians of smaller bandwidths than those resulting from the traditional single‐scale stencils; (2) lead to significantly faster Newton's method convergence than the single‐scale stencils; and (3) produce more accurate solutions than the single‐scale stencils.The LRR method, including the LRR multiple‐scale stencils, is finally applied to an engineering problem governed by strongly coupled, highly non‐linear PDEs: a steady‐state lean Bunsen flame with complex chemistry, multicomponent transport, and radiation modeling. Very good agreement is observed between the computed flame height and previously published experimental data. Copyright © 2001 John Wiley & Sons, Ltd.
An efficient high‐order algorithm for solving systems of reaction‐diffusion equations
Authors: Liao Wenyuan , Zhu Jianping , Khaliq Abdul Q.M. 
Published: August 2002

AbstractAn efficient higher‐order finite difference algorithm is presented in this article for solving systems of two‐dimensional reaction‐diffusion equations with nonlinear reaction terms. The method is fourth‐order accurate in both the temporal and spatial dimensions. It requires only a regular five‐point difference stencil similar to that used in the standard second‐order algorithm, such as the Crank‐Nicolson algorithm. The Padé approximation and Richardson extrapolation are used to achieve high‐order accuracy in the spatial and temporal dimensions, respectively. Numerical examples are presented to demonstrate the efficiency and accuracy of the new algorithm. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 340–354, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/num.10012
Modeling condom‐use stage of change in low‐income, single, urban women*
Authors: Morrison‐Beedy Dianne , Carey Michael P. , Lewis Brian P. 
Published: August 2002

AbstractThis study was undertaken to identify and test a model of the cognitive antecedents to condom use stage of change in low‐income, single, urban women. A convenience sample of 537 women (M=30 years old) attending two urban primary health care settings in western New York State anonymously completed questionnaires based primarily on two leading social‐cognitive models, the transtheoretical model and the information–motivation–behavioral skills model. We used structural equation modeling to examine the direct and indirect effects of HIV‐related knowledge, social norms of discussing HIV risk and prevention, familiarity with HIV‐infected persons, general readiness to change sexual behaviors, perceived vulnerability to HIV, and pros and cons of condom use on condom‐use stage of change. The results indicated two models that differ by partner type. Condom‐use stage of change in women with steady main partners was influenced most by social norms and the pros of condom use. Condom‐use stage of change in women with “other” types (multiple, casual, or new) of sexual partners was influenced by HIV‐related knowledge, general readiness to change sexual behaviors, and the pros of condom use. These findings suggest implications for developing gender‐relevant HIV‐prevention interventions. © 2002 Wiley Periodicals, Inc. Res Nurs Health 25:122–134, 2002
Intensity of case managers' participation in organizational decision making§
Authors: Issel L. Michele , Anderson Ruth A. 
Published: August 2002

AbstractPrior research has indicated that registered nurse (RN) participation in decision making (PDM) is related to better outcomes in nursing homes and hospitals. Little is known, however, about the roles of community‐based case managers (CMs), most of whom are RNs. Data from 68 prenatal case management programs were used to test hypotheses about the intensity of CM PDM and to describe their patterns of involvement in decision activities and mechanisms. CMs were most involved in the activity of “raising the issue” and least involved in “choosing the alternative.” However, “choosing the alternative” was the strongest predictor of perceived CM influence over the final choice. When CMs were involved in informal meetings and chance encounters with administrators, they were more likely to be perceived as having influence over the final choices made. Intensity of CM PDM varied by decision level and content, supporting two of the three hypotheses. The findings are discussed in light of prior research and complexity theory. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24:361–372, 2001
Improving cognitive development of low‐birth‐weight premature infants with the COPE program: A pilot study of the benefit of early NICU intervention with mothers
Authors: Melnyk Bernadette Mazurek , Alpert‐Gillis Linda , Feinstein Nancy Fischbeck , Fairbanks Eileen , Schultz‐Czarniak Jaclyn , Hust Diane , Sherman Laura , LeMoine Christine , Moldenhauer Zendi , Small Leigh , Bender Nancee , Sinkin, MD Robert A. 
Published: August 2002

AbstractThe purpose of this pilot study was to evaluate the effectiveness of a parent‐focused intervention program (COPE) on infant cognitive development and maternal coping. A randomized clinical trial was conducted with 42 mothers of low‐birth‐weight (LBW) premature infants hospitalized in a neonatal intensive care unit (NICU), with follow‐up at 3 months' and 6 months' corrected ages. COPE mothers received the four‐phase educational–behavioral program that began 2–4 days postbirth and continued through 1 week following discharge from the NICU. Comparison mothers received audiotaped information during the same four time frames. Results indicated that COPE infants had significantly higher mental development scores at a 3 months' corrected age (M = 100.3) than did the comparison infants (M = 93.9), and this difference widened at 6 months' corrected age, with COPE infants scoring 14 points higher. COPE mothers were significantly less stressed by the NICU sights and sounds and had significantly stronger beliefs about what behaviors and characteristics to expect from their premature infants. Findings from this study support the need for further testing of early NICU interventions with parents to determine their effectiveness on parental coping and infant developmental outcomes. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24:373–389, 2001
The sustainability of resources used by Native Americans on four Caribbean islands
Authors: Wing Elizabeth S. 
Published: August 2002

AbstractChanges in the subsistence economies during the 2000‐year colonization of the Leeward and Virgin islands are discussed. The colonists migrated from northern South America with traditions for producing ceramics, engaging in horticulture, fishing, gathering, and managing captive animals. Based on analysis of pairs of faunal samples from four islands, I am able to show some consistent changes in the relative abundances of some species, the sizes of individual animals, and the mean trophic levels of the aquatic components of the faunas. The changes that take place through time are: decline in the relative abundance of land crabs; a relative increase in the abundance of molluscs; decline in the mean trophic level of reef fishes; a subsequent increase or decrease in the mean trophic level of inshore and pelagic fishes. In those sites where the mean trophic level of inshore and pelagic fishes occurs it is dominated by tuna and other large predators, increased dependence upon herrings and other small fishes reduced the mean trophic level. These changes accompanied a human population increase and intensification of the horticultural enterprise. The root cause of many of these changes is overexploitation. Compensation for the decline in some resources is accomplished through changes in fishing technology. Copyright © 2001 John Wiley & Sons, Ltd.
Osteological features associated with ankle hyperdorsiflexion
Authors: Boulle Eve‐Line 
Published: August 2002

AbstractThe habitual adoption of certain gestures and postural habits can result in a variety of non‐metric traits, including supernumerary facets that are both articular and non‐articular. The squatting facet is a classical example of the former, and generally presents as a lateral articular facet on the neck of the talus that articulates with a facet on the anterior border of the distal tibia. These facets arise owing to the adoption of the squatting position and the hyperdorsiflexed position of the ankle joint, bringing the talus and tibia into immediate approximation. This study reports on the difference between the classical squatting facet and a non‐articular facet, which can also present on the neck of the talus but occurs, probably, as a result of soft tissue pressure, rather than bony articulation. It is suggested that whilst the function of the two facets may be similar, their aetiology is likely to be very different. Copyright © 2001 John Wiley & Sons, Ltd.
Car ownership and welfare‐to‐work
Authors: Ong Paul M. 
Published: August 2002

AbstractThis study examines the role of car ownership in facilitating employment among recipients under the current
welfare‐to‐work law. Because of a potential problem with simultaneity, the analysis uses predicted
car ownership constructed from two instrumental variables, insurance premiums and population density for car
ownership. The data come from a 1999–2000 survey of TANF recipients in the Los Angeles metropolitan area.
The empirical results show a significant independent contribution of car ownership on employment. The presence of
an predicted ownership is associated with a 9 percentage point increase in the odds of being employed. Moreover,
the results indicate that lowering insurance premiums by $100 can increase the odds of employment by 4
percentage points. © 2002 by the Association for Public Policy Analysis and Management.
Synthesis of polymethylmethacrylate in THF solution with phosphorous containing initiators
Authors: Poljans̆ek Ida 
Published: August 2002

AbstractFor the synthesis of polymethylmethacrylate, tetraphenyl biphosphine (TPhBP) with a thermally and photochemically unstable P‐P bond was employed. Under the influence of UV light, this bond split to two relatively stable biphenylphosphine radicals, which are able to react with the monomer. The resultant macroinitiators were isolated and were used for further polymerization with the same or another monomer to synthesize block‐copolymers.Controlled polymerization of methyl methacrylate with tetraphenyl biphosphine took place in the absence of oxygen by UV irradiation in THF solution. For MMA alone an insignificant portion photo‐ (0.3%) and thermal‐ (2%) polymerization were detected. Using selected quantity of the initiator, macroinitiators with predicted molecular weight as well as block‐copolymers were synthesized.The macroradicals were terminated by primary ‐PPh
2 radicals, by chain transfer to initiator and by the combination of two macroradicals. We determined chain end groups by nuclear magnetic resonance spectroscopy (NMR) and the relative molecular weights of the polymers by gel permeation chromatography (GPC). The molecular weights were calculated using the
1H NMR spectra from the ratio between the end groups signals and signals of the chain and were compared to GPC measurements. The calculated and observed molecular weights were in good agreement. At the lower concentration of initiator the molecular weight increased with conversion, while at the higher initiator concentration the molecular weight decreased with increasing conversion which could be ascribed to chain transfer to initiator. Copyright © 2001 John Wiley & Sons, Ltd.