bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human bone marrow stromal cell and ligament fibroblast responses on RGD‐modified silk fibers
Authors: Chen Jingsong , Altman Gregory H. , Karageorgiou Vassilis , Horan Rebecca , Collette Adam , Volloch Vladimir , Colabro Tara , Kaplan David L. 
Published: October 2003

AbstractAdhesion, spreading, proliferation, and collagen matrix production of human bone marrow stromal cells (BMSCs) on an RGD‐modified silk matrix was studied. Anterior cruciate ligament fibroblasts (ACLFs) were used as a control cell source. Scanning electron microscopy (SEM) and MTT analyses demonstrated that the modified silk matrices support improved BMSC and ACLF attachment and show higher cell density over 14 days in culture when compared with the non‐RGD‐modified matrices. Collagen type I transcript levels (at day 7) and content (at day 14) was significantly higher on the RGD‐modified substrate than on the nonmodified group. The ability of RGD‐coupled silk matrices to support BMSC attachment, which leads to higher cell density and collagen matrix production in vitro, combined with mechanical, fatigue, and biocompatibility properties of the silk protein matrix, suggest potential for use of this biomaterial for tissue engineering. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 559–570, 2003
Novel complexation hydrogels for oral peptide delivery: In vitro evaluation of their cytocompatibility and insulin‐transport enhancing effects using Caco‐2 cell monolayers
Authors: Ichikawa Hideki , Peppas Nicholas A. 
Published: October 2003

AbstractPoly[methacrylic acid‐grafted‐poly(ethylene glycol)] [P(MAA‐g‐EG)] is a complexation hydrogel molecularly designed for oral peptide delivery. In this work, the cytotoxicity and insulin‐transport enhancing effect of P(MAA‐g‐EG) microparticles on intestinal epithelial cells were evaluated using Caco‐2 cell monolayers. A series of P(MAA‐g‐EG) microparticles with different polymer compositions were prepared by a photo‐initiated free radical solution polymerization and subsequent pulverization. The hydrogel microparticles were preswollen in either Ca2+‐containing (CM+) or Ca2+‐free medium (CM−; pH 7.4) and applied to the apical side of the Caco‐2 monolayers. No significant cytotoxic effects, as determined by a calorimetric assay with P(MAA‐g‐EG) microparticles preswollen in the CM+, were observed at doses ranging from 3 to 31 mg/cm2 of cell monolayer. Transepithelial electrical resistance (TEER) measurements showed that the P(MAA‐g‐EG) microparticles induced a Ca2+ concentration‐dependent lowering in TEER values. The reduction effect in CM− media was greater than that in CM+ media (17 ± 2% reduction in CM+ and 45 ± 3% reduction in CM−, respectively). Insulin transport in the presence of the preswollen P(MAA‐g‐EG) microparticles was also strongly depended on the Ca2+ concentration in the medium. The respective estimated permeability for insulin alone and the insulin with hydrogels in CM+ were 0.77 and 1.16 × 10−8 cm/s, whereas those in CM− were 1.18 and 24.78 × 10−8 cm/s. The results demonstrate that the P(MAA‐g‐EG) hydrogel microparticles could be used as a cytocompatible carrier possessing the transport‐enhancing effect of insulin on the intestinal epithelial cells. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 609–617, 2003
Fibronectin anchorage to polymer substrates controls the initial phase of endothelial cell adhesion
Authors: Pompe Tilo , Kobe Fritz , Salchert Katrin , Jørgensen Birgitte , Oswald Joachim , Werner Carsten 
Published: October 2003

AbstractEarly stages of the adhesion of human endothelial cells onto a set of smooth polymer films were analyzed to reveal the modulation of cell–matrix interactions by the physicochemical constraints of predeposited fibronectin (FN). Hydrophobic and hydrophilic polymer substrates, consisting of poly(octadecene‐alt‐maleic anhydride) and poly(propene‐alt‐maleic anhydride) films, were coated with similar amounts of FN at conditions of either covalent or noncovalent immobilization. The well‐defined substrates permit variation of the anchorage of FN at invariant topography, pliability, and molecular composition. Although all of the compared FN coatings were effective in stimulating attachment of endothelial cells, the initial formation of cell–matrix adhesions was found to be controlled by the type of interaction between predeposited FN and the underlying substrate. Covalent linkage and hydrophobic interactions of the predeposited FN with the polymer films interfered with the rapid generation of focal and fibrillar adhesions. It was demonstrated that this was caused by the fact that only weakly bound FN could become readily reorganized by the adherent cells. Upon prolonged culture periods at standard cell culture conditions, secretion and deposition of organized extracellular matrix by the attached cells was found to balance out the differences of the substrates. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 647–657, 2003
Extended delivery of the antimitotic agent colchicine from thermoresponsive N‐isopropylacrylamide‐based copolymer films to human vascular smooth muscle cells
Authors: Wilson S. J. , Gorelov A. V. , Rochev Y. A. , McGillicuddy F. , Dawson K. A. , Gallagher W. M. , Keenan A. K. 
Published: October 2003

AbstractThe aim of this study was to establish the capacity of thermoresponsive poly(N‐isopropylacrylamide) copolymer films to deliver bioactive concentrations of an antimitotic agent to human vascular smooth muscle cells (HASMC) over an extended period of time. Copolymer films were prepared using a 50:50 (w/w) ratio of N‐isopropylacrylamide (NiPAAm) monomer to the more hydrophobic N‐tert‐butylacrylamide (NtBAAm) and loaded with the antimitotic agent colchicine (0.1 μmol per film) at room temperature. Colchicine release from films was sustained over a 14‐day period. At 24 h postloading, the concentration of colchicine in the medium overlying films was 2.12 ± 0.16 μM; this fell to 0.20 ± 0.01 μM at 7 days and decreased further to 0.12 ± 0.01 μM after 14 days. Colchicine released from copolymer films inhibited proliferation when subsequently placed on HASMC: at 0.1 μM, released colchicine reduced proliferation to 18.5 ± 0.8% of control cells (p < 0.001, n = 9). The antiproliferative effect of released colchicine was comparable to that of native colchicine, as observed in separate experiments. Furthermore, colchicine released from 50:50 polymer films inhibited the proliferation of cells grown in the same environment as the copolymer. Inhibition of cell proliferation was not due to the release of cytotoxic particles from the copolymer because medium incubated with copolymer for 5 days and then applied to HASMC did not alter cell viability. In conclusion, this study demonstrates that 50:50 NiPAAm:NtBAAm copolymers can deliver bioactive concentrations of the antimitotic agent colchicine to human vascular cells over an extended period of time. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 667–673, 2003
Immunocamouflage: Prevention of transfusion‐induced graft‐versus‐host disease via polymer grafting of donor cells
Authors: Chen Audrey M. , Scott Mark D. 
Published: October 2003

AbstractGraft‐versus‐host disease (GVHD) can occur following the transfer of allogeneic lymphocytes into immunosuppressed and, in rare cases, immunocompetent recipients. The initiation of GVHD requires the allorecognition of the recipient's disparate MHC molecules by the donor T lymphocytes (T cell). Currently, GVHD is controlled by cyclosporine administration—a potent, but toxic, T‐cell suppressing agent. To determine if the nontoxic grafting of methoxypoly(ethylene glycol) (mPEG) to immunologically foreign lymphocytes could prevent allorecognition and GVHD, in vitro and in vivo murine studies were performed. In vitro studies utilizing mixed lymphocyte reactions (MLRs) demonstrate that mPEG modification effectively prevented allorecognition and subsequent T‐cell proliferation. The loss of cellular proliferation was not due to mPEG cytotoxicity but rather to the inhibition of cell–cell interactions. Flow cytometric studies showed that T‐cell and antigen‐presenting cell adhesion molecules (CD2, CD11a), signaling (CD3ϵ, T‐cell receptor), and costimulatory molecules (CD28, CD80) were efficiently immunocamouflaged by mPEG derivatization. Interestingly, upon antigenic stimulation mPEG‐modified cells demonstrate enhanced apoptosis as evidenced by DNA laddering. In vivo studies using immunocompetent and immunosuppressed mice established that mPEG modification of donor lymphocytes effectively attenuated the in vivo proliferation of donor cells and the initiation of GVHD. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 626–636, 2003
The uniqueness theorem for complex‐valued neural networks and the redundancy of the parameters
Authors: Nitta Tohru 
Published: October 2003

AbstractA complex neural network is obtained from an ordinary network by extending the (real‐valued) parameters, such as the weights and the thresholds, to complex values. Applications to problems involving complex numbers, such as communications systems, are expected. This paper presents the following uniqueness theorem. When a complex function is given, the three‐layered neural network that approximates the function is uniquely determined by a certain finite group, if it is irreducible. The above finite group specifies the redundancy of the parameters in the complex neural network, but has a structure which is different from that of the real‐valued neural network. The order of the finite group is examined, and it is shown that the redundancy of the complex‐valued neural network is an exponent multiple of the redundancy of the real‐valued neural network. Analysis of the redundancy is important in the theoretical investigation of the basic characteristics of complex‐valued neural networks, such as the local minimum property. A sufficient condition is derived for the given three‐layered complex‐valued neural network to be minimal. The above results are shown, in essence, by extending the approach of Sussmann for real‐valued neural networks. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(14): 54–62, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10363
Event‐related potentials during a target discrimination task based on texture cue
Authors: Jung Jiuk , Kobayashi Tetsuo , Li Yuwen , Kuriki Shinya 
Published: October 2003

AbstractIn the current research, to elucidate cerebral processes having to do with target‐ground discrimination based on a texture cue in visual stimuli, the authors investigated the relationship between the target presentation area in the visual field and the reaction time required until discrimination. Also, they simultaneously measured the event‐related potentials (ERPs) during a target discrimination task at 63 locations on the scalp and then performed a spline Laplacian analysis to examine brain activities. The results clearly showed that a significant difference occurred in the reaction time depending on the area in which the target was presented. In addition, four distinct ERP components with different latencies accompanying execution of the discrimination task were observed. The spline Laplacian analysis of the ERPs indicated that the sources of the signals of these components were in the bilateral hemispheres of the frontal, parietal, and occipital lobes. Considering the reaction time, the frontal activity observed after the latency of about 270 ms may mainly be involved in the target recognition. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(14): 34–43, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10397
A fast morphological filtering algorithm
Authors: Hagihara Yoshihiro , Kobatake Hidefumi 
Published: October 2003

AbstractThis paper proposes an algorithm for fast morphological filtering using structuring elements of arbitrary two‐dimensional shape. The conventional fast morphological filtering has the constraint that the structuring element should be decomposable. The proposed method solves this problem by adding the result for the area which becomes a new object of calculation as a result of the motion of the structuring element and deleting the result for the area which goes outside the object for calculation. The proposed method has the feature that the calculation result is retained for each area deleted simultaneously from the object of calculation, and then morphological filtering is realized. Compared to the conventional fast algorithm, the constraint is reduced in the sense that undecomposable structuring elements can be used, and the method can be applied to multivalued images. Furthermore, the processing speed is independent of the density resolution of the considered image. The computation complexity is O(4rs) for the case of a circular structuring element, for example, where r is the radius of the structuring element and s is the number of pixels in the original image. This paper presents an experiment for comparison between the proposed algorithm and the conventional algorithm. The experiment reveals that the proposed algorithm is approximately twice as fast as the conventional fast method. An experiment is also performed for ring‐shaped structuring elements, to which the conventional fast method is difficult to apply, and the result is compared to the conventional method without speed improvement. The results reveal that the processing time in the method without speed improvement increases when the number of pixels in the structuring element is increased, but it does not increase in the proposed method. Thus, the proposed method is more effective when the processing time required in the conventional method is long. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(14): 23–33, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10438
Directory‐traverse‐cost‐based skew handling for parallel data access
Authors: Watanabe Akitsugu , Yokota Haruo 
Published: October 2003

AbstractTechniques for load balancing by adjusting location of data are widely studied, because they are quite influential in improving the data‐access performance and the scalability of a parallel system. To make load balancing effective, distributed directory structures, methods for evaluating loads, and distributed control mechanism for handling skews are important. In this paper, we propose a distributed algorithm to evaluate loads precisely. It counts the loads of intermediate index nodes of a distributed directory, which were ignored in previous publications. We also propose a linear‐order distributed skew‐handling algorithm adopting the proposed load evaluation algorithm. We validate the effect of our load evaluation algorithm through simulations. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(14): 13–22, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10445
A quick search method for multimedia signals using global pruning
Authors: Kimura Akisato , Kashino Kunio , Kurozumi Takayuki , Murase Hiroshi 
Published: October 2003

AbstractThe authors propose a new method for quickly searching for a specific audio or video signal to be detected within a long, stored audio or video stream to determine segments that contain signals that are nearly identical to the given signal. The Time‐series Active Search (TAS) method is one of the quick search methods that have been proposed previously. This signal searching technique based on histograms extracted from the signals had implemented quick searching by local pruning, that is, omitting comparisons of segments for which searching was unnecessary based on similarities in the vicinity of the matching window. In contrast, the proposed technique implements significantly quicker searching by introducing global pruning, which looks at the entire signal time‐series according to histogram classifications based on similarities of the entire signal to eliminate segments that need not be searched, in addition to local pruning. In this paper, the authors present a detailed discussion of the relationship between the degree of global pruning and the accuracy that is guaranteed. For example, the authors showed through experiments that when 128‐dimension histograms were classified to 1024 clusters, the proposed technique achieved a search speed approximately 9 times that of TAS while preserving the same degree of accuracy. The preprocessing calculation time increased by approximately 1% of the time for playing the signal. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(13): 47–58, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10472
Speaker change detection and speaker clustering using VQ distortion measure
Authors: Nakagawa Seiichi , Mori Kazumasa 
Published: October 2003

AbstractThis paper addresses the problem of the detection of speaker changes and clustering speakers when no information is available regarding speaker classes or even the total number of classes. This study provides preprocessing for a method which adapts speaker information based on incremental on‐line speaker clustering. We assume that no previous information on speakers is available (no speaker model, no training phase) and that people do not speak simultaneously. The aim is to apply speaker grouping information to speaker adaptation for speech recognition.We use Vector Quantization (VQ) distortion as the criterion. A speaker model is created from successive utterances as a codebook by a VQ algorithm, and the VQ distortion is calculated between the model and an utterance.The results of an experiment on speaker detection and speaker clustering are presented. The speaker change detection experiment was compared with results of the Generalized Likelihood Ratio (GLR) and Bayesian Information Criterion (BIC). By using GLR and BIC, we obtained F‐measures of 75.8 and 81.4, respectively. On the other hand, we obtained an F‐measure of 84.4 by the proposed method. Furthermore, by a combination of the method with an acoustic back‐off method, we obtained a measure of 93.1 and a classification rate of 97.7%. These results show the superiority of our proposed method. Finally, we demonstrate the validity of our proposed method by experiments on speech recognition using on‐line speaker adaptation. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(13): 25–35, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10488
Multi‐viewpoint gesture recognition by an integrated continuous state machine
Authors: Kawashima Hiroaki , Matsuyama Takashi 
Published: October 2003

AbstractThis paper proposes a system architecture for event recognition that dynamically integrates information from multiple sources (e.g., multimodal data from visual and auditory sensors). The proposed system consists of multiple event classifiers called Continuous State Machines (CSMs). Each CSM has a state transition rule in a continuous state space and classifies time‐varying patterns from a different single source. Since the rule is defined as an extension of Kalman filters (i.e., the next state is deduced from the trade‐off scheme between the input data and the model's prediction), CSMs support dynamic time warping and robustness against noise. We then introduce an interaction method among CSMs to classify events from multiple sources. A continuous state space (i.e., vector space) allows us to design interaction as minimization of an energy function. This interaction enables the system to dynamically suppress unreliable classifiers and improves system reliability and the accuracy of classifying events in dynamically changing situations (e.g., the object is temporary occluded from one of multiple cameras in a gesture recognition task). Experimental results on gesture recognition by two cameras show the effectiveness of our proposed system. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(14): 1–12, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10507
Contribution of vestibular (otolith) and pursuit system to stabilizing vision during sinusoidal head movement
Authors: Hikita Shinichi , Kasai Takeshi 
Published: October 2003

AbstractThe purpose of this study was to investigate how the vestibular (otolith) system and the visual pursuit system contribute to stabilizing vision during head translation. Eye velocity when fixating a stationary target with sinusoidal head movement (visually enhanced LVOR, VLVOR) was compared to that of smooth pursuit (SP) with the same relative target velocity (20 to 180 deg/s) as in the case of VLVOR. The eye velocity during VLVOR was much higher than that during SP with increasing relative target velocity. The gain of the SP (eye velocity/target velocity) markedly decreased with increasing stimulus frequency (0.6 → 1.2 Hz) while the gain of the VLVOR decreased only slightly. The eye velocity during VLVOR depended on the target velocity, not on the velocity of head motion, and was not associated with the state of vergence. These findings suggest that the command signal of the VLVOR is generated mostly by the visual pursuit system, and that the signal from the otolith system modifies the command signal of the pursuit system to improve the target tracking performance. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(13): 13–24, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10513
Tracking of a moving object with occlusion by using an active vision system
Authors: Hada Takaya , Miyake Tetsuo 
Published: October 2003

AbstractA person can keep an object which moves according to rules in roughly the center of their field of vision at all times. Even if the object is occluded during its movement, the person can continue to track it by estimating its later motion. In this paper, this kind of human system is taken into consideration for an automatic monitoring system, and such a system is constructed using an active vision system with a pan and tilt rotary mechanism. In order to automatically monitor a scene over a wide area at high resolution, the object to be monitored must be tracked while changing the pan and tilt using active vision. The tracking principle used in this system consists of detecting a moving object and estimating its motion. Detection is accomplished by using a background subtraction method which uses a background database, and motion estimation is handled by a Kalman filter. An experiment is performed on a person in a typical room environment, and it is confirmed that the person can be tracked by the proposed system even when occluded. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(13): 92–102, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1222