bluuebunny/crossref_metadata_2025_split huggingface dataset:
Construction of graphs with given circular flow numbers
Authors: Pan Zhishi , Zhu Xuding 
Published: July 2003

AbstractSuppose r ≥ 2 is a real number. A proper r‐flow of a directed multi‐graph $\vec {G}=(V, E)$ is a mapping $f: E \to R$ such that (i) for every edge $e \in E$, $1 \leq |f(e)| \leq r-1$; (ii) for every vertex ${v} \in V$, $\sum _{e \in E^{+(v)}}f(e) - \sum _{e \in E^{-(v)}}f(e) = 0$. The circular flow number of a graph G is the least r for which an orientation of G admits a proper r‐flow. The well‐known 5‐flow conjecture is equivalent to the statement that every bridgeless graph has circular flow number at most 5. In this paper, we prove that for any rational number r between 2 and 5, there exists a graph G with circular flow number r. © 2003 Wiley Periodicals, Inc. J Graph Theory 43: 304–318, 2003
Hepatocellular carcinoma of diffuse type: MR imaging findings and clinical manifestations
Authors: Kanematsu Masayuki , Semelka Richard C. , Leonardou Polytimi , Mastropasqua Maria , Lee Joseph K.T. 
Published: July 2003

AbstractPurpose:To assess MR imaging findings and clinical manifestations of diffuse‐type hepatocellular carcinoma (HCC).Materials and Methods:We retrospectively reviewed our experience with diffuse HCC from November 1994 to October 2001. MR imaging findings and clinical features were assessed.Results:Twenty‐two consecutive patients with diffuse‐type HCC (19 men and three women, age range 16–80 years [mean, 52 years]) were identified in a review of liver MR studies. This represented 13% of all patients with HCC imaged during this time period. Diffuse HCC showed a permeative, infiltrative pattern with ill‐defined borders and no evidence of convex margination in all cases. At least 50% of the liver volume was involved with tumor. Diffuse‐type HCC showed hypointensity in 15 patients, mixed intensity in three, and isointensity in four on T1‐weighted images; heterogeneous hyperintensity in 16 patients; and homogeneous hyperintensity in six on T2‐weighted MR images. Diffuse‐type HCC showed patchy enhancement in 12 patients, miliary enhancement in nine, and minimal enhancement in one on postcontrast early‐phase images, and showed heterogeneous wash‐out in all patients on postcontrast late‐phase images. Proximal portal venous tumor thrombosis was seen in all patients. Serum α‐fetoprotein (AFP) value was elevated (>10 ng/mL) in 14 of 18 patients, and 13 showed a value greater than 500 ng/mL. The four patients who did not have elevated AFP had tumors which were indistinguishable from those in patients with elevated AFP; they also did not have a distinctive clinical history.Conclusion:Diffuse‐type HCC was typically seen as an extensive, heterogeneous permeative hepatic tumor, with portal venous tumor thrombosis on MR images in all cases. Early enhancement, observed as patchy in 12 and miliary in nine of 22 patients, was a distinctive imaging feature. Elevated serum AFP value was a common finding; however, 22% had normal values. J. Magn. Reson. Imaging 2003;18:189–195. © 2003 Wiley‐Liss, Inc.
Liver metastases from pancreatic adenocarcinoma: MR imaging characteristics
Authors: Danet Ioana‐Maria , Semelka Richard C. , Nagase Larissa L. , Woosely John T. , Leonardou Polytimi , Armao Diane 
Published: July 2003

AbstractPurpose:To describe the magnetic resonance imaging spectrum of appearances of liver metastases from pancreatic ductal adenocarcinoma.Materials and Methods:We retrospectively evaluated the MRI exams performed between July 1996 and August 2001 in all patients who had liver metastases from pancreatic adenocarcinoma and histopathologic diagnosis from either the primary pancreatic tumor, liver metastases, or both. Sixteen patients were included in the study. All MR studies were performed at 1.5 T with a standard protocol including T1‐ and T2‐weighted images and serial post‐gadolinium spoiled gradient echo (SGE) images. Location, size, number, signal characteristics on T1‐ and T2‐weighted images, and pattern of enhancement on serial gadolinium‐enhanced SGE images were assessed.Results:The diameter of metastases ranged from a few millimetres to 4 cm, and 12 patients (75%) had only lesions of 1.5 cm or less. Capsular‐based liver metastases were found in 13 patients (81%) and three patients had only capsular‐based lesions with a diameter under 1.5 cm. Hypervascular lesions were found in six patients (38%) and hypovascular lesions in 10 patients (62%). Perilesional enhancement was present in 10 patients (62%), with six patients (38%) having ring perilesional enhancement and eight patients (50%) having wedge‐shaped perilesional enhancement.Conclusion:On MR imaging, hepatic metastases from pancreatic adenocarcinoma show a range of enhancement patterns. Hypervascular metastases are not rare. Capsular based distribution, small diameter, and perilesional enhancement are common features. This retrospective study describes the MR imaging spectrum of appearances of liver metastases from pancreatic adenocarcinoma in patients with histopathologic confirmation of the diagnosis. J. Magn. Reson. Imaging 2003;18:181–188. © 2003 Wiley‐Liss, Inc.
Functional MRI of the rat lumbar spinal cord involving painful stimulation and the effect of peripheral joint mobilization
Authors: Malisza Krisztina L. , Stroman Patrick W. , Turner Allan , Gregorash Lori , Foniok Tadeusz , Wright Anthony 
Published: July 2003

AbstractPurpose:To examine neuronal activation in the spinal cord due to secondary hyperalgesia resulting from intrajoint capsaicin injection, and the effect of physiotherapy manipulation, using functional magnetic resonance imaging (fMRI), in α‐chloralose anesthetized rats.Materials and Methods:FMRI of the rat lumbar spinal cord was performed at 9.4 Tesla. Stimuli included injection of 25 μL of capsaicin (128 μg/mL in 7.5% dimethyl sulfoxide [DMSO]) into the right forepaw or 75 μL into the right ankle joint followed by a light touch stimulus, with and without physiotherapy manipulation.Results:Activation of pain areas of the spinal cord (dorsal horn) was found in all animals after injection of capsaicin into the plantar surface of the rat hindpaw and ankle joint. Overlay maps depicting activations and deactivations showed significant reproducibility between experiments. Greater overlay of activations were observed for intrajoint compared to intradermal capsaicin injection. The distribution of activations after stimulation of the hindpaw using a light touch stimulus was somewhat more varied; activation of the dorsal horn was evident, with greater overlap resulting when joint mobilization was not performed.Conclusion:Results suggest a trend toward decreased areas of activation in the spinal cord associated with pain, as a result of hyperalgesia, following physiotherapy joint mobilization. J. Magn. Reson. Imaging 2003;18:152–159. © 2003 Wiley‐Liss, Inc.
Improved detection of metastases on magnetic resonance images by digital tissue recognition: Validation using VX‐2 tumor in the rabbit
Authors: Wyman Bradley T. , Stork Chris L. , Smith Justin P. , Price Roger E. , Gavin Patrick R. , Tucker Russell L. , Wisner Erik R. , Mattoon John S. , Hazle John D. 
Published: July 2003

AbstractPurpose:To evaluate the ability of a prototype digital tissue recognition (DTR) system to improve the accuracy of detection of metastases on magnetic resonance (MR) images in the rabbit VX‐2 tumor model.Materials and Methods:Multiple MR imaging (MRI) sequences, including pre‐contrast and post‐contrast enhanced T1‐weighted, T2‐weighted, proton‐density, and fast short inversion time inversion recovery (FSTIR), were acquired for six rabbits implanted with VX‐2 adenocarcinoma. For each rabbit, DTR used the MR intensity characteristics of a known tumor site to highlight other areas suspicious for tumor. Three independent veterinary radiologists with extensive experience in animal MRI interpreted the images for tumor both without and with the results of DTR. The conventional and DTR‐assisted interpretations were compared to pathology.Results:Using DTR, the radiologists found an average of 13.2% more true positive sites with a 10.3% reduction in false positives compared to unassisted interpretation. The improvement for the radiologists was statistically significant (McNemar's test, P = 0.0004). The agreement between radiologists using DTR was consistently higher than for their conventional interpretations (kappa statistic).Conclusion:Compared with conventional interpretation of MR images, the use of DTR provided a statistically significant improvement in the accuracy of locating more and smaller sites of tumor. This improvement was achieved without the benefit of post‐contrast images. J. Magn. Reson. Imaging 2003;18:232–241. © 2003 Wiley‐Liss, Inc.
Characterization of interpolation effects in cine anatomic and phase‐velocity images
Authors: Wood John C. 
Published: July 2003

AbstractPurpose:To compare actual and predicted frequency response of reconstruction algorithms applied to anatomic and phase‐contrast velocity cine images.Materials and Methods:Anatomic and phase‐contrast velocity segmented cine gradient echo images were collected from a stationary, doped‐agarose phantom, using non‐phase‐contrast cine and phase‐contrast cine with one to three directional encodings, one to 16 views per segment, and nearest‐neighbor or linear interpolation. Temporal power spectra from object pixels were fit to linear transfer function models; nearest‐neighbor interpolation by a sinc function and linear interpolation by a sinc2 function.Results:Simple linear transfer function models predicted >98% of the observed power spectral variation. Finite word effects produced small systematic differences at high temporal frequency.Conclusion:Temporal power spectra of cine images collected from stationary objects completely characterizes low pass filtration effects of interpolation. J. Magn. Reson. Imaging 2003;18:266–271. © 2003 Wiley‐Liss, Inc.
Autosomal dominant polycystic kidney disease: MR imaging evaluation using current techniques
Authors: Mosetti Maria Antonietta , Leonardou Polytimi , Motohara Tomofumi , Kanematsu Masayuki , Armao Diane , Semelka Richard C. 
Published: July 2003

AbstractPurpose:To determine the MR imaging findings of autosomal dominant polycystic kidney disease using current imaging techniques.Materials and Methods:We reviewed our five‐year experience with MR imaging of autosomal dominant polycystic kidney disease (ADPKD) to determine the spectrum of appearance of kidney disease, the occurrence of cysts in other abdominal organs, the size and number of cysts in the kidneys and other organs, and the association with other benign or malignant disease. Thirty patients (17 men and 13 women, age range 30 to 88 years old) with ADPKD were included in this study. All patients were examined by MR imaging including T2‐weighted single‐shot echo‐train spin‐echo and pre‐ and post‐gadolinium chelate spoiled gradient‐echo imaging.Results:All kidneys were involved with multiple, varying sized cysts scattered throughout the parenchyma. Giant renal cysts (>8 cm) were associated with pain in the only two patients who possessed them. Hemorrhage in renal cysts was observed in all kidneys with a heterogeneous pattern of involvement on non‐contrast T1‐ and T2‐weighted images, reflecting hemorrhage of varying age. The mean kidney size for the right kidney was 17.4 cm in length, 10.3 cm in transverse, and 9.4 cm in antero‐posterior diameter (AP); and for the left kidney, 15.9 cm in the length, 9.3 cm in the transverse, and 9.3 cm in AP diameter. Other organs involved included the liver (22 patients), the pancreas (three patients), with two of the above‐mentioned patients having both liver and pancreas cysts, and the spleen (one patient) who had both liver and splenic cysts. Massive liver involvement with large cysts was associated with abdominal pain. Malignant disease was present in five patients, including two patients with renal cell carcinoma, one with bladder cancer, one with lung cancer, and one patient with anal adenocarcinoma. Comparison of pre‐ and post‐contrast T1‐weighted images was essential to detect renal cancer.Conclusion:All kidneys in patients with ADPKD had extensive, varying‐sized cysts and in all cases some cysts showed evidence of hemorrhage. The liver was the second most common organ to be involved with cystic disease, in 73% of patients. Large cysts in the kidneys and liver were associated with abdominal pain. J. Magn. Reson. Imaging 2003;18:210–215. © 2003 Wiley‐Liss, Inc.
A framework for a streamline‐based probabilistic index of connectivity (PICo) using a structural interpretation of MRI diffusion measurements
Authors: Parker Geoffrey J.M. , Haroon Hamied A. , Wheeler‐Kingshott Claudia A.M. 
Published: July 2003

AbstractPurpose:To establish a general methodology for quantifying streamline‐based diffusion fiber tracking methods in terms of probability of connection between points and/or regions.Materials and Methods:The commonly used streamline approach is adapted to exploit the uncertainty in the orientation of the principal direction of diffusion defined for each image voxel. Running the streamline process repeatedly using Monte Carlo methods to exploit this inherent uncertainty generates maps of connection probability. Uncertainty is defined by interpreting the shape of the diffusion orientation profile provided by the diffusion tensor in terms of the underlying microstructure.Results:Two candidates for describing the uncertainty in the diffusion tensor are proposed and maps of probability of connection to chosen start points or regions are generated in a number of major tracts.Conclusion:The methods presented provide a generic framework for utilizing streamline methods to generate probabilistic maps of connectivity. J. Magn. Reson. Imaging 2003;18:242–254. © 2003 Wiley‐Liss, Inc.
Knowledge creation and the web: factors indicating why some intranets succeed where others fail
Authors: Stenmark Dick 
Published: July 2003

AbstractIn today's highly dynamic business environment, organizational creativity is one of the most important sources of competitive advantage. Although the unpredictability of creativity makes it difficult to plan for, it may still be possible to facilitate knowledge creation given that we understand what affects it. In this paper, seven enabling factors of organizational creativity are identified and discussed. These factors are then compared to the specific characteristics of intranet technology in order to find out when and how this environment may stimulate creativity. The conclusion is that intranets are most likely to contribute by providing a variety of information in dynamic and unpredictable environments. However, standard management literature instead unanimously prescribes organizational convergence as the default strategy for the modern manager. Our analysis suggests that this control approach not only conflicts with some of the creativity‐enabling factors but also clashes with the fundamental principles underpinning the web. The organizational implication of the conclusion presented in this paper is that only in organizations where management has embraced an updated attitude towards information management, can the corporate intranet truly contribute to knowledge creation and creativity. Copyright © 2003 John Wiley & Sons, Ltd.
Learning cycles, organizational back talk, and the persistence of theories in use: lessons of information systems development in a university administration context
Authors: Heiskanen Ari , Assinen Pauli 
Published: July 2003

AbstractLearning experiences from twenty‐seven administrative information‐system‐development projects in a large Finnish university are analysed over a time frame of eighteen years. A series of reporting development projects was chosen for more detailed inspection. Organizational learning was conceptualized to consist of cycles during which the organizational reactions towards development actions reveal the successfulness of each project. In a retrospective analysis the authors found three learning cycles out of the twelve‐year‐long reporting development process. The authors define their approach as reflective information systems practice and relate it to action learning and action science. Copyright © 2003 John Wiley & Sons, Ltd.
Building community knowledge systems: an empirical study of IT‐support for sharing best practices among managers
Authors: Bansler Jørgen P. , Havn Erling C. 
Published: July 2003

AbstractThe paper reports a field study of knowledge sharing in a large and complex organization. The objective of the study was to gain an in‐depth understanding of the implementation and use of a web‐based knowledge sharing system designed to facilitate the circulation of best practices among middle managers. We followed the system from its introduction in early 1997 until it was abandoned in the beginning of 2000. We focused on the way the system was introduced in the organization, how it changed, and how the intended group of users received (and eventually rejected) the system. Based on our interviews and observations we identify five reasons for the systems failure. We close the paper by some reflections on the use of the concept of ‘shared practice’ in the development of IT‐supported knowledge sharing systems. Copyright © 2003 John Wiley & Sons, Ltd.
Knowledge managing and knowledge management systems in inter‐organizational networks
Authors: Carlsson Sven A. 
Published: July 2003

AbstractIt is argued that the basic economic resource in the new economy is knowledge. An important source for competitive advantage in this economy is organizations' networks of external relationships. It is also argued that information and communication technologies (ICT) and Knowledge Management Systems (KMS) can play an important role in knowledge‐intensive processes and flows. This paper presents a conceptualization of strategic knowledge managing within the context of inter‐organizational networks. The conceptualization is based on the resource‐based, dynamic capability, and absorptive capability views as well as ideas from the ‘gift economy’. Three types of inter‐organizational networks for strategic knowledge managing are defined: (1) extra‐networks; (2) inter‐networks; and (3) open networks. The paper discusses knowledge managing in the three network types and illustrates how ICT and KMS can be used to enable and enhance knowledge managing in inter‐organizational networks—the core business process used for illustration is new product development. Copyright © 2003 John Wiley & Sons, Ltd.
Chain Connectivity and Conformational Variability of Polymers: Clues to an Adequate Thermodynamic Description of Their Solutions, 2
Authors: Wolf Bernhard A. 
Published: July 2003

AbstractIn Part 1 of this contribution we have reported how the Flory‐Huggins interaction parameterχcan be modeled as a function of chain length within the composition range of pair interaction between the macromolecules by means of the three parametersα,ζ, andλ. This contribution presents the extension of the approach to arbitrary volume fractions,φ, of the polymer and its application to published data onχ(φ). The resulting equation readsχ = α(1 − νφ)−2 − ζ(λ + 2(1 − λ)φ) and requires only the additional parameterνto incorporate the composition dependence. Its employment to experimental data is very much facilitated by substituting forχo(limiting value forφ → 0); furthermore, the expression can in good approximation be simplified toχ ≈ (χ0 + ζλ)(1 − νφ)−2 − ζλ(1 + 2φ). That is: only two parameters,νand the product ofζandλ, need to be adjusted. This relation is capable of describing all types of composition dependencies reported in the literature, including the hitherto incomprehensible occurrence of pronounced minima inχ(φ). For a given system the evaluation of the chain length dependence ofχo, reported in Part 1, and the present evaluation of the composition dependence ofχyield the same data for the conformational responseζ. Similarly both types of measurements generate the same interdependence betweenζandα. The physical meaning of the different parameters and the reason for the observed correlations are discussed.Interrelation betweenζλandαfor the evaluated systems.magnified imageInterrelation betweenζλandαfor the evaluated systems.
Supramolecular Branching and Crosslinking of Terpyridine‐Modified Copolymers: Complexation and Decomplexation Studies in Diluted Solution
Authors: Hofmeier Harald , Schubert Ulrich S. 
Published: July 2003

AbstractA series of poly(methyl methacrylate) copolymers with terpyridine units in the side chains was obtained by free radical polymerization. The free terpyridine units were complexed by iron(II) and zinc(II) ions, and the complexation behavior was studied in detail, utilizing UV‐vis and viscosity titration experiments. Complexation of the polymer chains could be observed, which resulted in characteristic UV‐vis absorption bands and an increase in the solution viscosity. Addition of a strong competitive ligand (hydroxyethyl ethylenediaminetriacetic acid, HEEDTA) resulted in an efficient decomplexation.UV‐vis spectra and photos of uncomplexed copolymer 2b before and after complexation with iron(II) ions (in chloroform) and after decomplexation with HEEDTA.magnified imageUV‐vis spectra and photos of uncomplexed copolymer 2b before and after complexation with iron(II) ions (in chloroform) and after decomplexation with HEEDTA.
Catalytic Chain Transfer Copolymerization of Methyl Methacrylate and Butyl Acrylate
Authors: Pierik Sebastiaan C. J. , van Herk Alex M. 
Published: July 2003

AbstractIn this work it is shown that catalytic chain transfer is a very efficient way of controlling molecular weight in the copolymerization of methyl methacrylate (MMA) and butyl acrylate (BA). The experimental data are compared to a previously developed model based on copolymerization kinetics and the mechanisms for catalytic chain transfer and for cobalt‐mediated living radical polymerization that can describe the observed transfer constants. Secondly, it is shown that the presence of a catalytic chain transfer agent does not affect the reactivity ratios within the concentration range studied. Finally, the effect of conversion and therewith composition drift on the catalytic chain transfer polymerization of MMA and BA is investigated and it is shown that under the conditions employed in the experiments a certain degree of macromer copolymerization is present at high partial conversions of MMA.Evolution of MWD with conversion for the CCT copolymerization of MMA and BA in toluene at 60 °C, [AIBN] = 6 × 10−3 mol · L−1.magnified imageEvolution of MWD with conversion for the CCT copolymerization of MMA and BA in toluene at 60 °C, [AIBN] = 6 × 10−3 mol · L−1.