bluuebunny/crossref_metadata_2025_split huggingface dataset:
Virtual base stations for wireless mobilead hoccommunications: an infrastructure for the infrastructure‐less
Authors: Hassanein Hossam , Safwat Ahmed 
Published: August 2002

AbstractIn this paper, we propose a new protocol for wireless mobilead hocnetworks, which establishes a dynamic wireless mobile infrastructure. The proposed protocol, namely, the virtual base stations (VBS) protocol, mimics and maintains the operation of the conventional fixed infrastructure in cellular networks. In the VBS protocol, a mobile node is elected from a set of nominees to act as a temporary base station within its zone. We provide proofs for the correctness of the VBS protocol, and show lower and upper bounds for its global convergence time. Likewise, we study the characteristics and performance of VBS by means of simulation. It is shown that VBS scales well to large networks of mobile stations, and that it outperforms other infrastructure‐formation protocols in terms of stability. The VBS protocol would facilitate the development of a comprehensive and promising framework for quality of service (QoS) management in wireless mobilead hocnetworks once the proper integration of the MAC protocol with the routing and call admission control mechanisms is established. The VBS architecture lays the groundwork for assigning bandwidth, and/or implementing priorities, and hence for QoS‐based routing by conveying the quality of a path prior to call setup. Copyright © 2001 John Wiley & Sons, Ltd.
Extending critical bandwidth allocation techniques for stored video delivery across best‐effort networks
Authors: Feng Wu‐chi , Liu Ming 
Published: August 2002

AbstractIn this paper, we propose two new techniques for the delivery of compressed prerecorded video streams across best‐effort networks like the Internet. Current approaches for the delivery of stored video across best‐effort networks typically alter the quality of the video frames, the frame rate delivered to the user, or a combination of both. By using network feedback, these algorithms continually adjust the video quality to fit within the available network resources. These approaches, however, do not take advantage of thea prioriinformation available from stored video streams, namely the frame sizes that the movie consists of. We will show how monitoring thea prioriinformation and actively monitoring a client‐side buffer can helpsmooththe video frame rate delivered to the user, providing a more consistent quality of video. Copyright © 2001 John Wiley & Sons, Ltd.
Optical switch dimensioning and the classical occupancy problem
Authors: Eramo Vincenzo , Listanti Marco , Nuzman Carl , Whiting Phil 
Published: August 2002

AbstractResults for optical switch dimensioning are obtained by analysing an urn occupancy problem in which a random number of balls is used. This analysis is applied to a high speed bufferless optical switch which uses tuneable wavelength converters to resolve contention between packets at the output fibres. Under symmetric packet routing the urn problem reduces to the classical occupancy problem. Since the problem is large scale and the loss probabilities are small, exact analysis by combinatorial methods is problematic. As an alternative, we outline a large deviations approximation which may be generalised in various ways. Copyright © 2002 John Wiley & Sons, Ltd.
Histologic and fine‐needle aspiration cytologic features of polycystic disease of the parotid glands: Case report and review of the literature
Authors: Layfield Lester J. , Gopez Evelyn V. 
Published: August 2002

AbstractPolycystic disease of the parotid glands is a rare disorder, with only eight examples to our knowledge being reported in the literature. The disease presents as a painless enlargement of one or both parotid glands and does not appear to be associated with other disease processes within the head and neck, or with polycystic disease of the kidney, pancreas, or congenital fibrosis of the liver. The histology has been well described. The overall glandular architecture is preserved but the lobules are markedly distended by cysts whose lining appears to be intercalated duct in differentiation. Characteristic eosinophilic laminated spheroliths lie in many of the cystic spaces. Aspirate smears are characterized by a relatively clean background in which are distributed histiocytes, red blood cells, and small clusters of ductal epithelial cells. Polycystic disease of the parotid glands must be differentiated cytologically from mucous retention reaction, mucoceles, benign lymphoepithelial cysts, and cystic neoplasms, including Warthin's tumor, low‐grade mucoepidermoid carcinoma, cystadenoma, and papillary cystadenocarcinoma. Diagn. Cytopathol. 2002;26:324–328. © 2002 Wiley‐Liss, Inc.
Accuracy of the smear technique in the cytological diagnosis of 650 lesions of the central nervous system
Authors: Bleggi‐Torres Luiz Fernando , de Noronha Lúcia , Schneider Gugelmin Elizabeth , Martins Sebastião Ana Paula , Werner Betina , Marques Maggio Ewerton , Queiroz Telles José Ederaldo , Martins Collaço Luiz 
Published: August 2002

AbstractThe authors analyzed the results of 650 lesions of the central nervous system submitted to intraoperative cytological diagnosis by the smear technique. Cytological and paraffin section diagnoses were compared. The following statistical values were obtained: accuracy of 97.3%, sensitivity of 97.9%, specificity of 95%, positive predictive value of 99.1%, and negative predictive value of 89.6%. The authors comment on their main pitfalls using this cytological diagnostic procedure. Diagn. Cytopathol. 24:293–295, 2001. © 2001 Wiley‐Liss, Inc.
T‐cell subtypes in bronchoalveolar lavage fluid and in peripheral blood from patients with primary lung cancer
Authors: Domagała‐Kulawik Joanna , Hoser Grażyna , Droszcz Paweł , Kawiak Jerzy , Droszcz Wacław , Chazan Ryszarda 
Published: August 2002

AbstractThe changes in local immunology play an important role in lung cancer development. We used bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) for the analysis of cell profiles in patients with primary lung cancer. Twenty‐one patients with confirmed primary lung cancer and 13 healthy volunteers were investigated. All persons were smokers. The analysis of T‐cell subsets was performed with a flow cytometry method and with the following antibodies: anti CD3, CD4, CD8, CD16, CD25, CD45, CD56, and HLA‐DR. We found differences in the proportion of lymphocytes between BALF and PB, and a higher proportion of T cells and a lower proportion of B and natural‐killer (NK) cells in BALF. There was a significant difference in the proportion of T‐cytotoxic/suppressor lymphocytes, which was elevated in the BALF of patients and decreased in patients' PB. The T‐helper:T‐cytotoxic/suppressor (Th:Tc/s) ratio was significantly lower in the BALF of patients. These changes were visible in patients with a small cell type. The percentage of T cells with the α chain of receptor to IL‐2 (IL ‐R) was lower in the BALF of patients than in the control group. Our observations reflect local changes in lung environment in patients affected with lung cancer. Diagn. Cytopathol. 25:208–213, 2001. © 2001 Wiley‐Liss, Inc.
P2‐mediated responses in osteoclasts and osteoclast‐like cells
Authors: Steinberg Thomas H. , Jørgensen Niklas R. , Bong Jeffrey S. , Henriksen Zanne , Atal Namita , Lin George C. , Bennett Brian D. , Eriksen Erik F. , Sørensen Ole H. , Civitelli Roberto 
Published: August 2002

AbstractOsteoclasts are multinucleated giant cells of the mononuclear phagocyte lineage that are responsible for bone resorption in vivo. Osteoprotegerin ligand (OPGL) has recently been identified as an important differentiation and activation factor for osteoclasts (Kong et al. [1999] Nature 397:315–323). We and others have demonstrated P2‐mediated responses in mononuclear phagocytes and ATP‐mediated effects on osteoclasts have also been described (Yu and Ferrier [1994] Cell Signal 6:905–914). The goal of these studies is to identify the role of P2 receptor activation in osteoclast formation and function. In particular, we assessed the role of P2 receptors in intercellular calcium signaling among macrophages and osteoclasts and between osteoblasts and osteoclasts, and studied the role of P2X7 in OPGL‐mediated osteoclast formation. We found that mechanically induced intercellular calcium signaling occurred between osteoblasts and osteoclasts, among J774 macrophage‐like cells, and among osteoclasts, but not among bone marrow‐derived macrophages. Interestingly, different P2 receptors seemed to be responsible for the propagation of intercellular calcium signals among different cells. In our studies of giant cell formation, we confirmed that expression of P2X7 enhances giant cell formation in J774 macrophages and in HEK cells. In contrast, RAW cell clones that were selected for resistance to ATP permeabilization were able to form giant cells in response to OPGL, suggesting that the pathways for giant cell and osteoclast may be different. Drug Dev. Res. 53:126–129, 2001. © 2001 Wiley‐Liss, Inc.
Different approaches to relating genotype to phenotype in developmental disorders
Authors: Karmiloff‐Smith Annette , Scerif Gaia , Thomas Michael 
Published: August 2002

AbstractIn this article, we discuss the complex problem of relating genotype to phenotype and challenge the simple mapping of genes to higher level cognitive modules. We examine various methods that have been used to investigate this relation including quantitative genetics, molecular genetics, animal models, and in‐depth psychological and computational studies of developmental disorders. Both single gene and multiple gene disorders indicate that the relationship between genotype and phenotype is very indirect and that, rather than identifying mere snapshots of developmental outcomes, the process of ontogenetic development itself must be taken into account. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 311–322, 2002. DOI 10.1002/dev.10035
Prospective study of diabetes mellitus and liver cancer in Japan
Authors: Fujino Yoshihisa , Mizoue Tetsuya , Tokui Noritaka , Yoshimura Takesumi 
Published: August 2002

AbstractBackgroundPrevious studies have identified the association between diabetes mellitus and liver cancer. However, the detail of this association is still unclear, in terms of confounding factors, the trend according to the duration of diabetes, and the interaction between diseases associated with the liver cancer and this association. The purpose of the present study was to examine the association between diabetes and liver cancer in view of the trend and the interaction.MethodsThe baseline survey was conducted during the period 1986–1989 among the general population of Fukuoka Prefecture, Japan (15 417 persons aged 30–79 years). The respondents were assessed for history of diabetes, age at which they had had diabetes, and other covariates by means of a baseline questionnaire. A total of 7308 persons aged 40–79 years were retrieved for the main analysis and 4902 persons for a subcohort from which the information on history of diseases associated with liver cancer were obtained. The relative risks (RRs) and their 95% confidence intervals (CIs) were estimated using the Cox proportional hazards model.ResultsAfter adjustment for smoking, alcohol and the diseases associated with liver cancer, the RR for liver cancer was 2.06 (95% CI=1.01–4.19). Diabetes increased the risk of liver cancer in persons with hepatitis and/or cirrhosis (RR=2.90, 95% CI=1.13–7.41). However, the RR of diabetes for liver cancer was 1.35 (95% CI=0.41–4.43) in persons without hepatitis and cirrhosis. The trend according to the duration of diabetes was not seen.ConclusionsA significant association between diabetes and liver cancer was observed. Moreover, this association was modified by hepatitis and cirrhosis. Copyright © 2001 John Wiley & Sons, Ltd.
Hepatic glucose uptake, gluconeogenesis and the regulation of glycogen synthesis
Authors: Radziuk J. , Pye S. 
Published: August 2002

AbstractHepatic glycogen is replenished during the absorptive period postprandially. This repletion is prompted partly by an increased hepatic uptake of glucose by the liver, partly by metabolite and hormonal signals in the portal vein, and partly by an increased gluconeogenic flux to glycogen (glyconeogenesis). There is some evidence that the direct formation of glycogen from glucose and that formed by gluconeogenic pathways is linked. This includes: (i) the inhibition of all glycogen synthesis, in vivo, when gluconeogenic flux is blocked by inhibitors; (ii) a dual relationship between glucose concentrations, lactate uptake by the liver and glycogen synthesis (by both pathways) which indicates that glucose sets the maximal rates of glycogen synthesis while lactate uptake determines the actual flux rate to glycogen; (iii) the decrease of both gluconeogenesis and glycogen synthesis by the biguanide, metformin; and (iv) correlations between increased gluconeogenesis and liver glycogen in obese patients and animal models. The degree to which the liver extracts portal glucose is not entirely agreed upon although a preponderance of evidence points to about a 5% extraction rate, following meals, which is dependent on a stimulation of glucokinase. This enzyme may be linked to the expression of other enzymes in the gluconeogenic pathway. Perivenous cells in the liver may induce additional gluconeogenesis in the periportal cells by increasing glycolytically produced lactate. A number of potential mechanisms therefore exist which could link glycogen synthesis from glucose and gluconeogenic substrate. Copyright © 2001 John Wiley & Sons, Ltd.
A novel POZ/zinc finger protein, champignon, interferes with gastrulation movements in Xenopus
Authors: Goto Toshiyasu , Hasegawa Kouichi , Kinoshita Tsutomu , Kubota Hiroshi Y. 
Published: August 2002

AbstractWe have cloned a novel krüppel‐like transcription factor of Xenopus that encodes POZ/zinc finger protein by expression cloning. Overexpression of mRNA resulted in interference with gastrulation. Because the injected embryo looks like a mushroom in appearance at the neurula stage, we have named this gene champignon (cpg). In cpg‐injected embryos, the blastopore appeared normally, but regressed thereafter. The injected embryos then elongated along the primary dorsoventral axis during the tailbud stage. Histologic sections and reverse transcription‐polymerase chain reaction analysis showed that cpg had no effect on the cell differentiation. The animal pole region of cpg‐injected embryos was thick during the gastrula stage, and mesodermal cells remained in the marginal zone. Furthermore, neither Keller‐sandwich explants nor activin‐treated animal cap explants excised from cpg‐injected embryos elongated. These results suggest that cpg acts as a potent inhibitor of cell migration and cell intercalation during gastrulation. © 2001 Wiley‐Liss, Inc.
Coexpression of endothelial PAS protein 1 with essential angiogenic factors suggests its involvement in human vascular development
Authors: Favier Judith , Kempf Hervé , Corvol Pierre , Gasc Jean‐Marie 
Published: August 2002

AbstractEndothelial PAS protein 1 (EPAS1) is a bHLH‐PAS transcription factor involved in cellular response to hypoxia. Its precise role in angiogenesis is unclear, but several genes essential to vascular development, including those encoding vascular endothelial growth factor (VEGF), its receptor VEGFR‐2 and Tie2, are thought to be targets of EPAS1. To investigate whether this transcription factor and its putative targets were expressed concomitantly, we performed in situ hybridization on serial adjacent sections of human embryos at gestational ages of 3 to 6 weeks. We studied expression of the genes encoding EPAS1, VEGF, VEGFR‐1, and ‐2, Tie2, and its ligands, angiopoietin (Ang) 1 and 2. We also compared these expression profiles with that of hypoxia‐inducible factor 1α (HIF1α). EPAS1 transcripts were detected in several types of endothelial cell: in blood vessels walls, the endocardium, the glomeruli of the mesonephros, and the sinusoids of the liver. In these endothelial cells, expression of EPAS1 systematically or partly coincided with Tie2 and the VEGF receptors expression. There was also some overlap between the sites of synthesis of EPAS1 and VEGF mRNAs, principally in hepatocytes and sympathetic ganglion cells. In addition, we found that EPAS1 and HIF1α transcripts were often colocalized, suggesting a functional redundancy of these two transcription factors during development. These observations are consistent with transactivation by EPAS1 of the expression of its putative target genes during embryogenesis, suggesting that this transcription factor is involved in human angiogenesis. They provide evidence that EPAS1 is involved in the regulation of vascular maturation, remodeling, or stabilization rather than in the early steps of embryonic angiogenesis. © 2001 Wiley‐Liss, Inc.
A design method to increase the signal‐to‐ambiguity ratio of scan SAR
Authors: Iwamoto Masafumi , Fujisaka Takahiko , Kirimoto Tetsuo , Mano Seiji 
Published: August 2002

AbstractScan synthetic aperture radar (SAR) is a synthetic aperture radar technique that observes a wide elevation width by conducting observations while successively switching the antenna orientation direction in the elevation direction. In this paper, we propose a method to increase the signal‐to‐ambiguity ratio (S/A ratio) in the azimuth direction of the image by adjusting the Scan SAR observation sequence. In addition, the procedure for planning the observation sequence by this method is presented and its effects are evaluated. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(12): 32–40, 2001
Shared concentration output queuing switch for multiple priority classes
Authors: Nishino Yoshiyuki , Sasase Iwao 
Published: August 2002

AbstractIn B‐ISDN, it is important to handle a variety of traffic having different loss probability requirements by using the same network. Since the shared concentration output queuing (SCOQ) switch has shared transmission networks, focus has been on its switch. In multimedia communications, the QoS (quality of service) is required and satisfied. Moreover, it is important to satisfy the requirement for cell loss probability. The switch has the advantage that the number of switching elements is small. However, it is not enough to correspond to priority classes. In this paper, we propose the SCOQ switch model for multiple priority classes, which is structured with a batcher network and independent banyan networks for each class and output buffers. We evaluate the cell loss probability and mean waiting time by computer simulations and analysis. The cell loss probability of the high‐priority class can be reduced since more high‐priority cells have priority to be transmitted to output buffers than low‐priority cells. As a result, we show that the proposed model is useful in satisfying different requirements of the cell loss probability for multiple priority classes. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 85(2): 41–50, 2002
100 km transmission of a 640 Gbit/s OTDM signal using femtosecond pulses
Authors: Yamamoto Takashi , Yoshida Eiji , Tamura Kohichi R. , Nakazawa Masataka 
Published: August 2002

AbstractA 640 Gbit/s OTDM (Optical Time Division Multiplexed) signal using femtosecond optical pulses was successfully transmitted over a distance of 101 km. As a signal light source, a regenerative mode‐locked fiber laser that generates 10‐GHz pulses with a small jitter was used. The transmission path consists of a zero‐dispersion dispersion‐flattened transmission line 101 km long made of a combination of a 1.3‐µm zero‐dispersion single‐mode fiber, a dispersion‐shifted fiber, and a reverse dispersion fiber. The 640 Gbit/s OTDM signal after transmission was demultiplexed by means of an ultra‐high‐speed nonlinear optical loop mirror with a fiber length of 450 m in which walk‐off between the signal light and the control light was reduced. The reverse dispersion fiber in the transmission path had smaller polarization dispersion than both the dispersion slope compensation fiber previously used for compensation of the dispersion slope compensation and the 1.3‐µm zero‐dispersion single‐mode fiber. In addition, the wavelength dependence of its dispersion is small. © 2002 Scripta Technica, Electron Comm Jpn Pt 1, 85(5): 48–56, 2002
A peak power reduction scheme with parity carrier for multicarrier modulation
Authors: Muta Osamu , Takata Tatsuhiko , Akaiwa Yoshihiko 
Published: August 2002

AbstractThis paper proposes a method which reduces the peak‐to‐mean power ratio (PMPR) of the multicarrier modulation signal by providing a subcarrier for peak power reduction outside the information band. The proposed method includes the addition of a redundant signal, that is, parity carrier, in order to reduce the peak power of the multicarrier signal when its envelope exceeds a given threshold. The parity carrier for peak power reduction is placed outside the band of the multicarrier signal and can be easily removed in the receiver. It is shown by a computer simulation that when two carriers for peak power reduction are added to the multicarrier signal with eight carriers, the PMPR after the peak power reduction approaches 4.7 dB. It is also shown for the case in which the power amplifier has little nonlinearity that an outband spectrum density of −50 dB can be achieved by applying the proposed method for a back‐off of 4.7 dB. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(8): 34–46, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1116
Speaker verification based on speaker background model virtually synthesized using local acoustic information
Authors: Isobe Toshihiro , Takahashi Jun‐ichi , Nakamura Taichi 
Published: August 2002

AbstractIn this paper, a likelihood normalization method for verifying a speaker based on an HMM is proposed. In the proposed method, a speaker background model used in likelihood normalization is synthesized from the HMMs of neighboring speakers on the basis of local acoustic information expressed by the phonemes, states, and distributions of the HMMs. By this method, the statistical intermodel distance between the speaker and the background speaker in the acoustic space can be minimized and effective normalization capable of absorbing variations in the likelihood can be realized statistically. When likelihood normalization by a cohort speaker model generated on the basis of the distribution (the proposed method) was compared with the past method of using the cohort speaker model selected for speakers in speaker verifying tests using the telephone voices of 640 people (open tests without time differentials using 320 speakers and 320 impersonators), the equal error rate (EER) was reduced from 5.27% to 1.76% by the proposed method. In addition, when likelihood normalization combining a speaker‐independent model and a cohort speaker model generated on the basis of the distributions was compared with a method using only a speaker‐independent model in texts using the telephone voices of 100 people (open tests with a time differential of 3 months using 24 speakers and 75 impersonators), the EER was reduced from 3.41% to 2.51%, confirming the efficacy of the proposed method. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 85(4): 47–57, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10045