bluuebunny/crossref_metadata_2025_split huggingface dataset:
Similarities and differences in female and male rat voiding
Authors: Streng Tomi , Santti Risto , Talo Antti 
Published: August 2002

AbstractWe measured in adult rats, under anaesthesia, bladder pressure by transvesical cystometry and flow rate by an ultrasound transducer in the distal urethra. The urinary flow was discontinuous in both sexes. No difference between the sexes in bladder pressure oscillations or in non‐oscillatory voiding was found but during the oscillatory activity there was a difference in the relationship between bladder pressure and urinary flow. In the female, the bladder pressure decreased when the flow started and increased when the flow decreased resembling species whose urinary flow is continuous. Basically the flow was stable but it was divided into periods of variable duration by full or partial closure of urethral sphincter. In the male rat, the oscillatory flow consisted of short, fast spikes occurring just before the bladder pressure reached the maximum, after which the flow spike decreased slowly. Overall, no differences were seen in bladder pressure data between the genders. However, the maximal flow rate was lower and micturition time was shorter in female rats. When we recorded occasionally occurring micturitions without high‐frequency oscillations of intraluminal pressure (IPHFOs) (non‐oscillatory voiding), no differences between the genders were seen. The difference during oscillatory voiding between male and female rat can be understood against anatomical and hormonal backgrounds, and by the relative role of rhabdosphincter, which did not activate during non‐oscillatory voidings when no differences were detected. Neurourol. Urodynam. 21:136–141, 2002. © 2002 Wiley‐Liss, Inc.
Voiding and incontinence frequencies: Variability of diary data and required diary length
Authors: Homma Yukio , Ando Takashi , Yoshida Masaki , Kageyama Shinji , Takei Mineo , Kimoto Kosuke , Ishizuka Osamu , Gotoh Momokazu , Hashimoto Tatsuru 
Published: August 2002

AbstractFrequencies of voiding and urinary incontinence are commonly measured by a patient's recall or a diary. The recommended diary length varies from 1 to 14 days, with 7 days apparently being most common. To examine the statistical precision of these different modalities, we analyzed recall data and diary data of 74 patients with urinary frequency, incontinence, or both. Recall data on voiding and incontinence frequency were systematically higher and more variable than diary data. Longer diary length provided less variable diary data. The confidence interval of diary data was calculated by applying the normal distribution to daytime voiding frequency and the Poisson distribution to daytime incontinence frequency. For daytime voiding frequency, the 95% confidence interval was estimated to be (x − 2.65, x + 2.65) (x − 1.53, x + 1.53) (x − 1, x + 1), where x is the 1‐day, 3‐day, and 7‐day diary mean, respectively. For daytime incontinence frequency, the confidence interval depended on both the diary length and the diary mean. It was estimated to be (0, 6.39), (1.72, 4.28), (2.36, 3.64), by using a diary mean of 3 or 1‐day, 7‐day, and 28‐day diaries, respectively. Also, it was estimated to be (0, 1.02), (1.72, 4.28), (7.66, 12.34), when the 7‐day diary mean was 0.5, 3, and 10, respectively. Studies with different samples of genuine stress incontinence (n = 37) and urge incontinence (n = 25) confirmed these results. In conclusion, we believe the 7‐day diary is highly reliable for estimating voiding frequency and is a reasonable option for predicting incontinence episodes. However, the diary length should be extended in a patient with rarer events of incontinence, and it should be shortened for those who are incontinent more often or who are diagnosed with voiding frequency only. Neurourol. Urodynam. 21:204–209, 2002. © 2002 Wiley‐Liss, Inc.
Light graphs with small routing cost
Authors: Wu Bang Ye , Chao Kun‐Mao , Tang Chuan Yi 
Published: August 2002

AbstractLet G = ({1,…, n}, E, w) be an undirected graph with nonnegative edge weights w and let aij be the nonnegative requirement between vertices i and j. For any spanning subgraph H of G, the weight of H is the total weight of its edges and the routing cost of H is Σi<j aijdH(i, j), where dH(i, j) is the distance between i and j in H. In this paper, we investigated two special cases of the problem of finding a spanning subgraph with small weight and small routing cost. For the case where all the distances in G are 1, we show that the problem is NP‐complete, and give a simple approximation algorithm for it. Furthermore, we define some sufficient conditions for the problem to be polynomial‐time solvable. For the case where all the requirements are 1, we develop an algorithm for finding a spanning tree with small weight and small routing cost. The algorithm provides trade‐offs among tree weights, routing costs, and time complexity. We also extend the results to some other related problems. © 2002 Wiley Periodicals, Inc.
Serotonin modulates locomotory behavior and coordinates egg‐laying and movement in Caenorhabditis elegans
Authors: Hardaker Laura Anne , Singer Emily , Kerr Rex , Zhou Guotong , Schafer William R. 
Published: August 2002

AbstractBiogenic amines have been implicated in the modulation of neural circuits involved in diverse behaviors in a wide variety of organisms. In the nematode C. elegans, serotonin has been shown to modulate the temporal pattern of egg‐laying behavior. Here we show that serotonergic neurotransmission is also required for modulation of the timing of behavioral events associated with locomotion and for coordinating locomotive behavior with egg‐laying. Using an automated tracking system to record locomotory behavior over long time periods, we determined that both the direction and velocity of movement fluctuate in a stochastic pattern in wild‐type worms. During periods of active egg‐laying, the patterns of reversals and velocity were altered: velocity increased transiently before egg‐laying events, while reversals increased in frequency following egg‐laying events. The temporal coordination between egg‐laying and locomotion was dependent on the serotonergic HSN egg‐laying motorneurons as well as the decision‐making AVF interneurons, which receive synaptic input from the HSNs. Serotonin‐deficient mutants also failed to coordinate egg‐laying and locomotion and exhibited an abnormally low overall reversal frequency. Thus, serotonin appears to function specifically to facilitate increased locomotion during periods of active egg‐laying, and to function generally to modulate decision‐making neurons that promote forward movement. © 2001 John Wiley & Sons, Inc. J Neurobiol 49: 303–313, 2001
Tyrosine phosphorylation of p190 RHOGAP by Fyn regulates oligodendrocyte differentiation
Authors: Wolf Rebecca M. , Wilkes Jennifer J. , Chao Moses V. , Resh Marilyn D. 
Published: August 2002

AbstractDuring development of the central nervous system, oligodendrocyte progenitor cells differentiate into mature myelinating cells. The molecular signals that promote this process, however, are not well defined. One molecule that has been implicated in oligodendrocyte differentiation is the Src family kinase Fyn. In order to probe the function of Fyn in this system, a yeast two hybrid screen was performed. Using Fyn as bait, p190 RhoGAP was isolated in the screen of an oligodendrocyte cDNA library. Coimmunoprecipitation and in vitro binding assays verified that p190 RhoGAP bound to the Fyn SH2 domain. Phosphorylation of p190 required active Fyn tyrosine kinase and was increased threefold upon differentiation of primary oligodendrocytes. Moreover, complex formation between p190 and p120 RasGAP occurred in differentiated oligodendrocytes. p190 RhoGAP activity is known to regulate the RhoGDP:RhoGTP ratio. Indeed, expression of dominant negative Rho in primary oligodendrocytes caused a hyperextension of processes. Conversely, constitutively activated Rho caused reduced process formation. These findings define a pathway in which Fyn activity regulates the phosphorylation of p190, leading to an increase in RhoGAP activity with a subsequent increase in RhoGDP, which in turn, regulates the morphological changes that accompany oligodendrocyte differentiation. © 2001 John Wiley & Sons, Inc. J Neurobiol 49: 62–78, 2001
Multigrid approaches to non‐linear diffusion problems on unstructured meshes
Authors: Mavriplis Dimitri J. 
Published: August 2002

AbstractThe efficiency of three multigrid methods for solving highly non‐linear diffusion problems on two‐dimensional unstructured meshes is examined. The three multigrid methods differ mainly in the manner in which the non‐linearities of the governing equations are handled. These comprise a non‐linear full approximation storage (FAS) multigrid method which is used to solve the non‐linear equations directly, a linear multigrid method which is used to solve the linear system arising from a Newton linearization of the non‐linear system, and a hybrid scheme which is based on a non‐linear FAS multigrid scheme, but employs a linear solver on each level as a smoother. Results indicate that, in the asymptotic convergence region, all methods are equally effective at converging the non‐linear residual in a given number of multigrid cycles, but that the linear solver is more efficient in cpu time due to the lower cost of linear versus non‐linear grid sweeps. Copyright © 2001 John Wiley & Sons, Ltd.
Woven fabric composites—part I: Predictions of homogenized elastic properties and micromechanical damage analysis
Authors: Choi Jaehyon , Tamma Kumar K. 
Published: August 2002

AbstractIn Part 1, the finite element developments are described to first predict the homogenized elastic properties of woven fabric composites, followed by a progressive damage analysis for the subsequent investigation of micromechanical damage initiations and propagations in the representative unit cell of woven fabric composites. For progressive damage analysis, in‐plane uniaxial tensile and shear loading are applied, respectively, to the unit cell. In order to make the boundaries of the unit cell remain straight, displacement control loading is applied instead of force control loading. The tensile and shear stress–strain curves are obtained and shown to be in good agreement with available experimental results. Utilizing the computational efforts in Part 1, the characterization of macro‐crack initiation loads is carried out in Part 2 for the global damage analysis without the need to resorting to experimental data for the prediction of damaged properties. Copyright © 2001 John Wiley & Sons, Ltd.
Self‐regular boundary integral equation formulations for Laplace's equation in 2‐D
Authors: Jorge A. B. , Ribeiro G. O. , Cruse T. A. , Fisher T. S. 
Published: August 2002

AbstractThe purpose of this work is to demonstrate the application of the self‐regular formulation strategy using Green's identity (potential‐BIE) and its gradient form (flux‐BIE) for Laplace's equation. Self‐regular formulations lead to highly effective BEM algorithms that utilize standard conforming boundary elements and low‐order Gaussian integrations. Both formulations are discussed and implemented for two‐dimensional potential problems, and numerical results are presented. Potential results show that the use of quartic interpolations is required for the flux‐BIE to show comparable accuracy to the potential‐BIE using quadratic interpolations. On the other hand, flux error results in the potential‐BIE implementation can be dominated by the numerical integration of the logarithmic kernel of the remaining weakly singular integral. Accuracy of these flux results does not improve beyond a certain level when using standard quadrature together with a special transformation, but when an alternative logarithmic quadrature scheme is used these errors are shown to reduce abruptly, and the flux results converge monotonically to the exact answer. In the flux‐BIE implementation, where all integrals are regularized, flux results accuracy improves systematically, even with some oscillations, when refining the mesh or increasing the order of the interpolating function. The flux‐BIE approach presents a great numerical sensitivity to the mesh generation scheme and refinement. Accurate results for the potential and the flux were obtained for coarse‐graded meshes in which the rate of change of the tangential derivative of the potential was better approximated. This numerical sensitivity and the need for graded meshes were not found in the elasticity problem for which self‐regular formulations have also been developed using a similar approach. Logarithmic quadrature to evaluate the weakly singular integral is implemented in the self‐regular potential‐BIE, showing that the magnitude of the error is dependent only on the standard Gauss integration of the regularized integral, but not on this logarithmic quadrature of the weakly singular integral. The self‐regular potential‐BIE is compared with the standard (CPV) formulation, showing the equivalence between these formulations. The self‐regular BIE formulations and computational algorithms are established as robust alternatives to singular BIE formulations for potential problems. Copyright © 2001 John Wiley & Sons, Ltd.
Numerical study of grid distribution effect on accuracy of DQ analysis of beams and plates by error estimation of derivative approximation
Authors: Shu C. , Chen W. , Xue H. , Du H. 
Published: August 2002

AbstractThe accuracy of global methods such as the differential quadrature (DQ) approach is usually sensitive to the grid point distribution. This paper is to numerically study the effect of grid point distribution on the accuracy of DQ solution for beams and plates. It was found that the stretching of grid towards the boundary can improve the accuracy of DQ solution, especially for coarse meshes. The optimal grid point distribution (corresponding to optimal stretching parameter) depends on the order of derivatives in the boundary condition and the number of grid points used. The optimal grid distribution may not be from the roots of orthogonal polynomials. This differs somewhat from the conventional analysis. This paper also proposes a simple and effective formulation for stretching the grid towards the boundary. The error distribution of derivative approximation is also studied, and used to analyze the effect of grid point distribution on accuracy of numerical solutions. Copyright © 2001 John Wiley & Sons, Ltd.
A three‐noded shear‐flexible curved beam element based on coupled displacement field interpolations
Authors: Raveendranath P. , Singh Gajbir , Venkateswara Rao G. 
Published: August 2002

AbstractAn efficient shear‐flexible three‐noded curved beam element is proposed herein. The shear flexibility is based on Timoshenko beam theory and the element has three degrees of freedom, viz., tangential displacement (u), radial displacement (w) and the section‐rotation (θ). A quartic polynomial interpolation for flexural rotation ψ is assumed a priori. Making use of the physical composition of θ in terms of ψ and u, a novel way of deriving the polynomial interpolations for u and w is presented, by solving force‐moment and moment‐shear equilibrium equations simultaneously. The field interpolation for θ is then constructed from that of ψ and u. The procedure leads to high‐order polynomial field interpolations which share some of the generalized degrees of freedom, by means of coefficients involving material and geometric properties of the element. When applied to a straight Euler–Bernoulli beam, all the coupled coefficients vanish and the formulation reduces to classical quintic‐in‐w and quadratic‐in‐u element, with u, w, and ∂w/∂x as degrees of freedom. The element is totally devoid of membrane and shear locking phenomena. The formulation presents an efficient utilization of the nine generalized degrees of freedom available for the polynomial interpolation of field variables for a three‐noded curved beam element. Numerical examples on static and free vibration analyses demonstrate the efficacy and locking‐free property of the element. Copyright © 2001 John Wiley & Sons, Ltd.
A numerical model for the time‐dependent cracking of cementitious materials
Authors: van Zijl G. P. A. G. , de Borst R. , Rots J. G. 
Published: August 2002

AbstractA unified finite element formulation is presented for the analysis of the time‐dependent cracking of cementitious materials. The rate‐type constitutive law incorporates linear visco‐elasticity and continuum plasticity. The former accounts for the bulk creep via a Maxwell chain, while the latter describes crack initiation and propagation via a softening, anisotropic Rankine yield criterion. The rate dependence of bond ruptures leading to fracture is accounted for by considering the viscosity of the cracking process. This contribution to the cracking resistance also regularises the localisation process. It is demonstrated how other important phenomena in cementitious materials, such as stress‐dependent hygral and thermal shrinkage, can be incorporated into the computational framework. Copyright © 2001 John Wiley & Sons, Ltd.
Two‐dimensional transonic aeroservoelastic computations in the time domain
Authors: Djayapertapa L. , Allen C. B. , Fiddes S. P. 
Published: August 2002

AbstractA computational method to perform transonic aeroelastic and aeroservoelastic calculations in the time domain is presented, and used to predict stability (flutter) boundaries of 2‐D wing sections. The aerodynamic model is a cell‐centred finite‐volume unsteady Euler solver, which uses an efficient implicit time‐stepping scheme and structured moving grids. The aerodynamic equations are coupled with the structural equations of motion, which are derived from a typical wing section model. A control law is implemented within the aeroelastic solver to investigate active means of flutter suppression via control surface motion. Comparisons of open‐ and closed‐loop calculations show that the control law can successfully suppress the flutter and results in an increase of up to 19 per cent in the allowable speed index. The effect of structural non‐linearity, in the form of hinge axis backlash is also investigated. The effect is found to be strongly destabilizing, but the control law is shown to still alleviate the destabilizing effect. Copyright © 2001 John Wiley & Sons, Ltd.
A computational scheme for linear and non‐linear composites with arbitrary phase contrast
Authors: Michel J. C. , Moulinec H. , Suquet P. 
Published: August 2002

AbstractA numerical method making use of fast Fourier transforms has been proposed in Moulinec and Suquet (1994, 1998) to investigate the effective properties of linear and non‐linear composites. This method is based on an iterative scheme the rate of convergence of which is proportional to the contrast between the phases. Composites with high contrast (typically above 104) or infinite contrast (those containing voids or rigid inclusions or highly non‐linear materials) cannot be handled by the method. This paper presents two modified schemes. The first one is an accelerated scheme for composites with high contrast which extends to elasticity a scheme initially proposed in Eyre and Milton (1999). Its rate of convergence varies as the square root of the contrast. The second scheme, adequate for composites with infinite contrast, is based on an augmented Lagrangian method. The resulting saddle‐point problem involves three steps. The first step consists of solving a linear elastic problem, using the fast Fourier transform method. In the second step, a non‐linear problem is solved at each individual point in the volume element. The third step consists of updating the Lagrange multiplier. Applications of this scheme to rigidly reinforced and to voided composites are shown. Copyright © 2001 John Wiley & Sons, Ltd.
Developing the productivity of a dynamic workforce: The impact of informal knowledge transfer
Authors: Lahti Ryan K. , Darr Eric D. , Krebs Valdis E. 
Published: August 2002

AbstractGiven the prevalence of career changes, job‐hopping, and alternative work arrangements, how do you get a
dynamic workforce up to speed? With all of the interest in the management of knowledge, what is the main
knowledge transfer mechanism to use to enhance contract‐worker and employee productivity? Today, more
organizations are using a nontraditional workforce. These organizations are utilizing contract workers as well as
employees as resources to provide services and manufacture products. This article focuses on enabling this dynamic
workforce to be productive by addressing the organizational socialization “policy,” the formal
knowledge transfer, and the informal knowledge transfer related to helping individuals perform at work. This
article especially focuses on informal knowledge transfer via social networks, because it is the type of knowledge
transfer that is the least understood by companies due to its being difficult to measure and improve. By using a
case study of a Fortune 100 company, the article reveals what types of knowledge are important to
transfer, the sources of the knowledge, and the mechanism used to transfer this knowledge. It also demonstrates
how informal knowledge transfer impacts performance and provides an indication of the effectiveness of
organizational socialization. © 2002 Wiley Periodicals, Inc.
Ralston Foods: from greenfield to maturity in a team‐based plant
Authors: Kibbe Daniel R. , Casner‐Lotto Jill 
Published: August 2002

AbstractSemiautonomous work groups have played a major role in the success of the Ralston Foods plant located in
Sparks, Nevada. Work groups, particularly those that are self‐directed, have produced
record‐breaking output levels and generated cost reductions over the past several years. Work groups are
responsible for many functions—everything from supporting capital projects, communications, customer
relations, and cost controls to discipline, performance appraisals, safety, and hiring. It took some time for us
as managers to relinquish those duties, but sticking to the participative process even at times when it feels
easier to revert to the traditional managerial role and focus solely on results has been a key factor in
sustaining our growth.The case study that follows details the operating philosophy of the Sparks plant and its evolution from a
retrofitted pet‐food operation into a mature, team‐based cereal plant—including both our
successes and difficulties and the key lessons learned along the way. While there are several qualities that
distinguish our team process at Sparks, a critical factor has been our responsiveness to change. This factor
will ensure our success in the future, as we develop a new mission and strategy in response to some
unprecedented business challenges and opportunities ahead. © 2001 Work in America
Institute