bluuebunny/crossref_metadata_2025_split huggingface dataset:
T‐cell subset counting and the fight against AIDS: Reflections over a 20‐year struggle
Authors: Mandy Francis , Nicholson Jan , Autran Brigitte , Janossy George 
Published: August 2002

AbstractThe story of T‐lymphocyte subset immunophenotyping technology is reviewed on the occasion of the 20th anniversary of CD4 T‐cell enumeration. Over time, immunophenotyping has evolved into precise, reliable, but complicated and expensive technology requiring fresh blood samples. The gating technologies that were universally adapted for clinical flow cytometry for the past decade relied on rapidly deteriorating morphological scatter characteristics of leukocytes. This special issue dedicated to CD4 T‐cell enumeration features most of the available new options that will have a significant impact on how this technology will be implemented within the first decade of the 21st century. In a series of original publications, including the new NIH guideline for T‐cell subset enumeration, contemporary gating protocols that use immunologically logical parameters are presented as part of the more reliable and affordable immunophenotyping alternative. Some of the improvements addressed here include the costs of the assays and the capacity to monitor interlaboratory and intralaboratory performances. It is clear that an effective attack on the human immunodeficiency virus (HIV) epidemic has to embrace resource‐poor regions. Reducing the cost of the assay while improving reliability and durability is a move in the right direction. Cytometry (Clin. Cytometry) 50:39–45, 2002. © 2002 Wiley‐Liss, Inc.
Reducing cell loss in banyan based ATM switching fabrics
Authors: Al‐Mouhamed M. , Kaleemuddin M. , Youssef H. 
Published: August 2002

AbstractIn this paper, we propose a new technique for reducing cell loss in multi‐banyan‐based ATM switching fabrics. We propose a switch architecture that uses incremental path reservation based on previously established connections. Path reservation is carried out sequentially within each banyan but multiple banyan planes can be concurrently reserved. We use a conflict resolution approach according to which banyans make concurrent reservation offers of conflict‐free paths to head of the line cells waiting in input buffers. A reservation offer from a given banyan is allocated to the cell whose source‐to‐destination path uses the largest number of partially allocated switching elements which are shared with previously reserved paths. Paths are incrementallyclusteredwithin each banyan. This approach leaves the largest number of free switching elements for subsequent reservations which has the effect of reducing the potential of future conflicts and improves throughput. We present a pipelined switch architecture based on the above concept ofpath‐clusteringwhich we callpath‐clustering banyan switching fabric(PCBSF). An efficient hardware that implements PCBSF is presented together with its theoretical basis. The performance and robustness of PCBSF are evaluated under simulateduniform trafficandATM traffic. We also compare the cell loss rate of PCBSF to that of other pipelined banyan switches by varying the switch size, input buffer size, and traffic pattern. Copyright © 2001 John Wiley & Sons, Ltd.
Buffer management and scheduling schemes for TCP/IP over ATM‐GFR
Authors: Wu Dapeng , Chao H. Jonathan 
Published: August 2002

AbstractToday ATM technology is facing challenges from integrated service IP, IP switching, gigabit IP router and gigabit ethernet. Although ATM is approved by ITU‐T as the standard technology in B‐ISDN, its survivability is still in question. Since ATM‐UBR (unspecified bit rate) provides no service guarantee and ATM‐ABR (available bit rate) is still unattainable for most users, many existing users have little or no incentives to migrate to ATM technology. The guaranteed frame rate (GFR) service is introduced to deal with this dilemma. The GFR can guarantee the minimum cell rate (MCR) with fair access to excess bandwidth. This paper studies various schemes to support the GFR. We have studied different discarding and scheduling schemes, and compared their throughput and fairness when TCP/IP traffic is carried. Through simulations, it is shown that only per‐VC queueing with weighted round robin (WRR) can guarantee minimum cell rate. Among all the schemes that have been explored, we recommend dynamic threshold–early packet discard (DT–EPD) integrated with MCR+ (a WRR variant) to support the GFR service. Copyright © 2001 John Wiley & Sons, Ltd.
Application of a new explicit‐rate ABR traffic controller
Authors: Lu Jun , Mir Nader F. 
Published: August 2002

AbstractIn broadband integrated communication systems, the classical method of max–min fair‐rate allocation for traffic control does not support the weighted‐rate guarantee. The weighted‐rate guarantee is necessary for available‐bit rate (ABR) service models. This fact motivates that the weighted max–min (WMM) fair‐rate allocation for the ABR traffic is widely studied. However, the combination of close‐loop feedback control with WMM algorithm has not appeared in the previous research. In this paper, a practical WMM fair‐rate allocation model is proposed. This scheduling scheme combines and integrates the congestion avoidance using proportional control (CAPC) and the weighted max–min fair‐rate allocation. This model is designed to achieve higher utilization and also bounded delay for ABR traffic flow control. In the system under analysis, the performance of this new weighted traffic scheduler is evaluated. The system presented in this paper is also compared with WMM and CAPC methods. Copyright © 2001 John Wiley & Sons, Ltd.
Linear and non‐linear space diversity combining algorithms over fading channels in TDMA systems
Authors: Benson M. , Carrasco R. A. 
Published: August 2002

AbstractThis paper investigates the performances of various adaptive algorithms for space diversity combining in time division multiple access (TDMA) digital cellular mobile radio systems. Two linear adaptive algorithms are investigated, the least mean square (LMS) and the square root Kalman (SRK) algorithm. These algorithms are based on the minimization of the mean‐square error. However, the optimal performance can only be obtained using algorithms satisfying the minimum bit error rate (BER) criterion. This criterion can be satisfied using non‐linear signal processing techniques such as artificial neural networks. An artificial neural network combiner model is developed, based on the recurrent neural network (RNN) structure, trained using the real‐time recurrent learning (RTRL) algorithm. It is shown that, for channels characterized by Rician fading, the artificial neural network combiners based on the RNN structure are able to provide significant improvements in the BER performance in comparison with the linear techniques. In particular, improvements are evident in time‐varying channels dominated by inter‐symbol interference. Copyright © 2001 John Wiley & Sons, Ltd.
Performance analysis of Robust WDM fast circuit‐switched networks with token passing in control channel
Authors: Abd‐Elmalak Samir A. , Vaishnav Chintan , Jayasumana Anura P. 
Published: August 2002

AbstractWDM networks depend on predetermined, fixed wavelength channels, requiring highly stable lasers and tunable filters. Robust WDM networks, based on dynamically selected wavelengths, relax manufacturing and operating wavelength tolerance requirements leading to low‐cost implementations. A node dynamically selects a currently unused wavelength for communication, and uses it for a limited period of time for communication with a destination, thus allowing the network to tolerate wavelength variation with time. A performance model is presented for Robust WDM networks in which the right to establish WDM connections is arbitrated periodically by a control channel based on token passing. Comparison with simulation results indicates the model's ability to predict the network performance accurately. Copyright © 2002 John Wiley & Sons, Ltd.
Myxopapillary ependymoma: Cytomorphologic characteristics and differential diagnosis
Authors: Kulesza Peter , Tihan Tarik , Ali Syed Z. 
Published: August 2002

AbstractMyxopapillary ependymoma (ME) is a rare tumor with a predilection for sacrococcygeal area of adults. We present the cytomorphology of one such case in a 21‐yr‐old man, diagnosed by fine‐needle aspiration (FNA). The tumor disclosed biphasic morphology with nests and aggregates of epithelioid malignant cells as well as branching cords of myxohyaline material. Most noticeable was the presence of distinct hyaline globules surrounded by neoplastic cells. The differential diagnosis of ME includes chordoma, adenoid cystic carcinoma, mucinous adenocarcinoma, and germ cell tumor. An accurate preoperative diagnosis of ME on FNA can be achieved based on its distinctive cytomorphologic features. Diagn. Cytopathol. 2002;26:247–250. © 2002 Wiley‐Liss, Inc.
Adenosine deaminase‐deficient mice as models for adenosine‐mediated lung inflammation and damage
Authors: Blackburn Michael R. , Zhong Hongyan 
Published: August 2002

AbstractAdenosine has been implicated to play a role in the inflammatory lung disease, asthma; however, there are few in vivo model systems with which to study the role of adenosine in aspects of this disease. We recently generated mice deficient in the purine catabolic enzyme adenosine deaminase (ADA) that controls the levels of adenosine in tissues and cells. Results presented here demonstrate that elevated adenosine levels in ADA‐deficient mice result in abnormal lung development and the promotion of lung inflammation and damage. ADA‐deficient mice exhibit alveolar defects that are overcome by biochemically restoring ADA enzymatic activity to these animals. In addition, lowering ADA substrates in the lung using enzyme therapy reverses lung eosinophilia and mucus production. These results suggest that elevated adenosine, and perhaps abnormal adenosine signaling, are implicated in abnormal lung development and lung inflammation and damage in ADA‐deficient mice. These mice will therefore serve as useful in vivo models in which to study the role of purinergic signaling in aspects of lung development and disease. Drug Dev. Res. 52:416–423, 2001. © 2001 Wiley‐Liss, Inc.
P2X7 nucleotide receptor: Modulation of LPS‐induced macrophage signaling and mediator production
Authors: Watters Jyoti J. , Sommer Julie A. , Fisette Philip L. , Pfeiffer Zachary A. , Aga Mini , Prabhu Usha , Guerra Alma N. , Denlinger Loren C. , Bertics Paul J. 
Published: August 2002

AbstractDuring infection or inflammation, high concentrations of extracellular nucleotides are released into the inflammatory microenvironment, supplying a source of ligand for purinergic receptors that are present on many immune cell types. The P2X7 receptor, a member of the P2X purinergic receptor family of ATP‐gated ion channels, is thought to play an important role in monocyte/macrophage activation. One factor that can powerfully activate macrophages is bacterial lipopolysaccharide (endotoxin, LPS) and although the mechanisms involved in this process are not well understood, it is clear that LPS activation of macrophages is central to the development of septic shock in response to Gram‐negative bacteria. Several lines of evidence have demonstrated strong modulatory effects of adenine nucleotides on the events associated with LPS stimulation of macrophages. Further, because the signal transduction cascades initiated in macrophages upon LPS exposure are similar to those resulting from P2X7 receptor stimulation, and because antagonism of the P2X7 receptor can attenuate LPS‐stimulated signaling events and mediator release, the P2X7 receptor has been implicated in the control of macrophage responses to LPS. In addition, our laboratory has identified a consensus LPS‐binding motif at the extreme carboxyl terminus of the P2X7 receptor, further supporting the potential for a direct interaction between LPS and this purinergic receptor. In this review, we discuss potential regulatory domains and structural features of the P2X7 receptor and outline some of the signal transduction pathways activated by P2X7 receptor agonists. Moreover, we present evidence supporting a critical role for the P2X7 receptor in modulating or mediating some of the biological effects of LPS in macrophages. Drug Dev. Res. 53:91–104, 2001. © 2001 Wiley‐Liss, Inc.
Cell proliferation during blastema formation in the regenerating teleost fin
Authors: Santos‐Ruiz Leonor , Santamaría Jesús A. , Ruiz‐Sánchez Josefa , Becerra José 
Published: August 2002

AbstractEpimorphic regeneration in teleost fins occurs through the establishment of a balanced growth state in which a blastema gives rise to all the mesenchymal cells, whereas definite areas of the epidermis proliferate leading to its extension, thus, allowing the enlargement of the whole structure. This type of regeneration involves specific mechanisms that temporally and spatially regulate cell proliferation. To understand how the blastema is formed and how this growth situation is set up, we investigated cell proliferation patterns in the regenerating fin of the goldfishCarassius auratusfrom the time of amputation to that of blastema formation by using proliferating cell nuclear antigen immunostaining and bromodeoxyuridine labeling. Wound closure and apical epidermal cap formation took place by epidermal migration and re‐arrangement, without the contribution of cell proliferation. As soon as the apical cap had formed, the epidermis started to proliferate at its lateral surfaces, in which all layers maintained cycling for the duration of the studied process. The distal epidermal cap, on the contrary, presented very few cycling cells, and its cytoarchitecture was indicative of continuous remodeling due to ray growth. The basal layer of this epidermal cap showed a typical morphology and remained nonproliferative whilst in contact with the proliferating blastema. Proliferation in the mesenchymal compartment of the ray started far from the amputation plane. Subsequently, cycling cells approached that location, until they formed the blastema in contact with the apical epidermal cap. Differences observed between the epidermis and mesenchyma, regarding activation of the cell cycle and the establishment of proliferative patterns, suggest that differential mechanisms regulate cell proliferation in each of these compartments during the initial stages of regeneration. © 2002 Wiley‐Liss, Inc.
Regulation of Epha4 expression in paraxial and lateral plate mesoderm by ectoderm‐derived signals
Authors: Schmidt Corina , Christ Bodo , Maden Malcolm , Brand‐Saberi Beate , Patel Ketan 
Published: August 2002

AbstractSomitogenesis in all vertebrates involves a mesenchymal to epithelial transition of segmental plate cells. Such a transition involves cells altering their morphology and their adhesive properties. The Eph family of receptor tyrosine kinases has been postulated to regulate cytoskeletal organization. In this study, we show that a receptor belonging to this family, EphA4, is expressed in the segmental plate in a region where cells are undergoing changes in cell shape as a prelude to epithelialization. We have identified the ectoderm covering the somites and the midline ectoderm as sources of signals capable of inducing EphA4. Loss of EphA4 results in cells of irregular morphology and somites fail to form. We also show that when somites fail to develop, expression of EphA4 in the lateral plate is also lost. We suggest that signaling occurs between the somites and the lateral plate mesoderm and provide evidence that retinoic acid is involved in this communication. © 2001 Wiley‐Liss, Inc.
Connexin43 gap junction protein plays an essential role in morphogenesis of the embryonic chick face
Authors: McGonnell Imelda M. , Green Colin R. , Tickle Cheryll , Becker David L. 
Published: August 2002

AbstractNormal outgrowth and fusion of facial primordia during vertebrate development require interaction of diverse tissues and co‐ordination of many different signalling pathways. Gap junction channels, made up of subunits consisting of connexin proteins, facilitate communication between cells and are implicated in embryonic development. Here we describe the distribution of connexin43 and connexin32 gap junction proteins in the developing chick face. To test the function of connexin43 protein, we applied antisense oligodeoxynucleotides that specifically reduced levels of connexin43 protein in cells of early chick facial primordia. This resulted in stunting of primordia outgrowth and led to facial defects. Furthermore, cell proliferation in regions of facial primordia that normally express high levels of connexin43 protein was reduced and this was associated with lower levels of Msx‐1 expression. Facial defects arise when retinoic acid is applied to the face of chick embryos at later stages. This treatment also resulted in significant reduction in connexin43 protein, while connexin32 protein expression was unaffected. Taken together, these results indicate that connexin43 plays an essential role during early morphogenesis and subsequent outgrowth of the developing chick face. © 2001 Wiley‐Liss, Inc.
A study on arrangement method of star couplers for passive double star systems
Authors: Tamaki Norio , Miki Noriki , Hashimoto Masashi , Kinoshita Takeshi , Watanabe Ryuichi 
Published: August 2002

AbstractFor economical construction of access networks, the passive double star (PDS) transmission system using optical fiber is promising. In the PDS transmission system, multiplexing of different transmission systems is possible due to wavelength division multiplexing (WDM). This system has drawn attention because addition of new service is easily accomplished. In this paper, an approach is proposed that is effective for wavelength division multiplexing in PDS transmission systems. When several systems with different transmit/receive level differences are transmitted over one fiber by wavelength division multiplexing, the transmission line length and the number must be adjusted to the system in which the transmit/receive level difference is the smallest in the conventional method. Hence, the application range of the system is degraded. On the other hand, in this paper, a method is proposed in which the loss distributions can be independently designed by cascading several star couplers when each system is wavelength division multiplexed. The method's procedure, evaluation of the efficiency of the accommodations, and an experimental example of an actual system are presented. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(7): 66–73, 2001
Rate‐adaptive indoor infrared wireless communication systems using punctured convolutional codes and adaptive PPM
Authors: Matsuo Michihito , Ohtsuki Tomoaki , Sasase Iwao , Udagawa Tomoyuki 
Published: August 2002

AbstractIn this paper, we propose rate‐adaptive indoor infrared wireless communication systems using punctured convolutional codes and adaptive pulse‐position modulation (PPM) to achieve high bit rates under various channel conditions with reasonable transmitter power. The proposed system varies the code rate of the rate compatible punctured convolutional (RCPC) codes and the modulation order of PPM adaptively according to the channel condition. When the channel condition is good, low‐order PPM and suitable code rates are selected, while high‐order PPM and suitable code rates are selected when the channel condition is bad. We analyze the performance of the proposed system on hybrid line‐of‐sight (LOS) channels. Our results show that the proposed system can achieve high bit rates by varying the code rate of the RCPC codes and the modulation order of PPM adaptively according to the channel conditions. Moreover, our results show that the proposed system can achieve longer horizontal separation between the transmitter and the receiver than that of conventional systems with repetition codes. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(8): 31–39, 2001
Resonant dc/dc converter with class DE tuned power oscillator
Authors: Matsuo Mitsuhiro , Suetsugu Tadashi , Mori Shinsaku , Sasase Iwao 
Published: August 2002

AbstractIn this paper, we propose a new resonant dc/dc converter with a class DE tuned power oscillator and a center‐tapped rectifier. The proposed converter uses a class DE tuned power oscillator as a dc/ac inverter. The MOSFET is used as a switch, which does not require any external drive circuits. Thus, compared to conventional inverters, the proposed circuits is effective in downsizing. Since the proposed circuit satisfies the class E switching operating condition, that is, the switching turns on and off instantaneously at zero voltage and zero slope of the voltage, highly efficient operation is possible at high frequencies. The proposed circuit is analyzed theoretically and is verified experimentally. The measured maximum dc/dc conversion efficiency is 75.8% at 2 MHz and 2.5 W. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(12): 61–69, 2001
Suppressing undesired modes in a higher‐order mode microstrip ring patch antenna
Authors: Tanaka Masato , Takahashi Norio 
Published: August 2002

AbstractThe authors propose the principles for a higher‐order mode ring patch antenna with a conical pattern with good symmetry for suppressing undesired modes and a simple configuration for creating such an antenna. In addition, the authors propose loading a degenerate separation element as a means to implement circular polarization in a higher‐ order mode ring patch antenna of this configuration and then confirm the circular polarization through experiments. The antenna has a simple configuration in which a microstrip line is positioned inside the ring and power is fed from the rear at the central point. The antenna offers the following advantages: line length to the edge of the power supply point and the ring patch that is roughly λ/4; and impedance at the power supply point that can be readily matched. Moreover, because the power supply point is at the central point of the ring patch antenna, this configuration is also beneficial in that it can be easily used for an array antenna by using it as an element of an array antenna that needs to be rotated and positioned, such as a sequential array antenna or a radial array antenna. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 85(3): 9–18, 2002
Application of Multirate Filter Bank to Group Demodulation of Frequency‐Multiplexed TDMA Signals
Authors: Matsuda Takahiro , Hara Shinsuke , Morinaga Norihiko 
Published: August 2002

AbstractAs a method to obtain the baseband signal from each of several time division multiple access (TDMA) signals that are frequency‐multiplexed in the uplink in wireless communication, this paper proposes a method of group demodulation using a multirate filter bank. The proposed method allows demodulation when the TDMA signals are asynchronously received in the uplink. Further, it can be applied to the case in which TDMA signals with different bandwidths are frequency‐multiplexed, if the multiple resolution capability of the multirate filter bank is used. Hence, this method is useful in the situation where several different types of signals coexist in such environments as software radio. In the systems discussed in this paper, it is necessary to realize a sharp amplitude response and a linear phase response in the filters of the multirate filter bank with a small computational effort. This is accomplished in this paper by using an infinite impulse response (IIR) filter with approximately linear phase response. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 85(4): 44–52, 2002