bluuebunny/crossref_metadata_2025 huggingface dataset:
Prognostic factors for death after an isolated local recurrence in patients with early‐stage breast carcinoma
Authors: Lê Monique G. , Arriagada Rodrigo , Spielmann Marc , Guinebretière Jean‐Marc , Rochard France
Published: August 2002

BACKGROUND

The authors analyzed the outcome of patients with early‐stage breast carcinoma after an isolated local recurrence, taking into account initial tumor characteristics and the type of initial treatment and local salvage treatment.

METHODS

One hundred five patients were studied who presented with a breast tumor measuring ≤ 25 mm and who subsequently developed an isolated local recurrence (breast or chest wall) as the first tumor event. A second series included 335 patients who developed distant metastases as the first event. Cox models that took into account potential prognostic factors were used to estimate the risk of death. First, survival rates were compared after an isolated local recurrence and after a diagnosis of distant metastases; and, second, effects of initial treatments and local or systemic treatments of local recurrences were analyzed.

RESULTS

The 10‐year survival rate was 56% (95% confidence interval, 45–65%) after an isolated local recurrence compared with 9% (95% confidence interval, 7–13%) after distant metastasis as the first event. Three independent prognostic factors for the risk of death after local recurrence were identified: histologic tumor grade, patient age at the time of diagnosis with the primary tumor, and disease free interval until recurrence. The type of initial treatment and local salvage treatment did not influence the risk of death. Systemic treatments of local recurrence had different effects according to the patient's menopausal status. In premenopausal patients, ovarian suppression and chemotherapy significantly decreased the risk of death. In postmenopausal women, systemic treatments did not affect the risk of death.

CONCLUSIONS

Isolated local recurrences in patients with early‐stage breast carcinoma carry a moderately good prognosis. The outcome of patients is not affected by the type of initial treatment or local salvage treatment. After a local recurrence, ovarian suppression or chemotherapy had a beneficial effect in premenopausal patients. Cancer 2002; 94:2813–20. © 2002 American Cancer Society.

DOI 10.1002/cncr.10572
Cholinergic innervation of the chick basilar papilla
Authors: Zidanic Michael
Published: August 2002

Antibodies directed against choline acetyltransferase (ChAT), the synthesizing enzyme for acetylcholine (ACh) and a specific marker of cholinergic neurons, were used to label axons and nerve terminals of efferent fibers that innervate the chick basilar papilla (BP). Two morphologically distinct populations of cholinergic fibers were labeled and classified according to the region of the BP they innervated. The inferior efferent system was composed of thick fibers that coursed radially across the basilar membrane in small fascicles, gave off small branches that innervated short hair cells with large cup‐like endings, and continued past the inferior edge of the BP to ramify extensively in the hyaline cell area. The superior efferent system was made up of a group of thin fibers that remained in the superior half of the epithelium and innervated tall hair cells with bouton endings. Both inferior and superior efferent fibers richly innervated the basal two thirds of the BP. However, the apical quarter of the chick BP was virtually devoid of efferent innervation except for a few fibers that gave off bouton endings around the peripheral edges. The distribution of ChAT‐positive efferent endings appeared very similar to the population of efferent endings that labeled with synapsin antisera. Double labeling with ChAT and synapsin antibodies showed that the two markers colocalized in all nerve terminals that were identified in BP whole‐mounts and frozen sections. These results strongly suggest that all of the efferent fibers that innervate the chick BP are cholinergic. J. Comp. Neurol. 445:159–175, 2002. © 2002 Wiley‐Liss, Inc.
Experience‐dependent plasticity of zinc‐containing cortical circuits during a critical period of postnatal development
Authors: Land Peter W. , Shamalla‐Hannah Lorraine
Published: August 2002

Distinctive subsets of glutamatergic neurons in cerebral cortex sequester the transition metal zinc within the synaptic vesicles of their axon terminals. In the present study we used histochemical localization of synaptic zinc to investigate normal postnatal development and experience‐dependent plasticity of zinc‐containing circuits in somatosensory barrel cortex of rats. First, we found that zinc‐containing cortical circuits are dynamically reorganized between postnatal day (P) 0 and P28. Whereas most cortical laminae exhibited idiosyncratic increases in zinc histochemical staining with advancing age, lamina IV barrels were darkly reactive early in life and then lost much of their complement of synaptic zinc during postnatal weeks 2–4. Second, we established that sensory experience plays a major role in sculpting the zinc‐containing innervation of cortical barrels. Trimming a particular facial whisker arrested the normal postnatal decline in synaptic zinc in the corresponding, deprived barrel. This resulted in more intense zinc staining in deprived barrels compared with adjacent, nondeprived barrels. Notably, the influence of experience on development of zinc circuits was most robust during a critical period extending from about P14, when an effect of whisker trimming first could be observed, through P28, after which time chronic deprivation no longer resulted in heightened levels of synaptic zinc in lamina IV. These findings indicate that sensory input can have a marked influence on development of cortical circuits, including those within lamina IV, throughout the first postnatal month. J. Comp. Neurol. 447:43–56, 2002. © 2002 Wiley‐Liss, Inc.
Establishment of left‐right asymmetric innervation in the lancelet oral region
Authors: Kaji Takao , Aizawa Shinichi , Uemura Masanori , Yasui Kinya
Published: August 2002

Lancelets (amphioxus) exhibit a remarkable asymmetric development in the anterior body region, which is reflected in the peripheral nervous system even at adulthood. Not all of the anterior nerves are involved, but the left third to fifth nerves are clearly asymmetric. To trace the developmental process responsible for asymmetric innervation, the peripheral nerves in the anterior region were studied in pre‐ and mid‐metamorphic larvae, 1‐cm‐long juveniles, and in adults by using whole‐mount immunostaining. The mouth changes in size and location during larval life before moving ventrally and, in conjunction with this change, nerves in the oral region are also modified. The left second nerve initially innervates the oral region, but this connection is secondarily lost. As the mouth expands and shifts posteriorly, the left fifth to ninth nerves join the left third and fourth in the innervation of the oral region. The left third to sixth nerves anastomose with the oral nerve ring, which encircles the mouth on the left side. In the juveniles and adults, there are two nerve plexuses that run parallel to the margin of the oral hood. The innermost of these, the “inner oral‐hood nerve plexus”, is asymmetrically connected with the left third to fifth nerves on both sides. The other, the “outer oral‐hood nerve plexus”, is ipsilaterally connected with the third to seventh nerves on both sides. The velar nerve ring is also innervated asymmetrically by the left fourth and fifth nerves. From these observations, we suggest that the oral nerve ring is the precursor of both the inner oral‐hood nerve plexus and the velar nerve ring, and that the asymmetric innervation retained in adult lancelets is related to the early anastomosis of the left nerves with the oral nerve ring. We also show that, contrary to the persistent asymmetric innervation, the axonal patterns of the anterior peripheral nervous system in developing lancelets can change. J. Comp. Neurol. 435:394–405, 2001. © 2001 Wiley‐Liss, Inc.
Development of the perforating pathway: An ipsilaterally projecting pathway between the medial septum/diagonal band of Broca and the cingulate cortex that intersects the corpus callosum
Authors: Shu Tianzhi , Shen Wei‐Bin , Richards Linda J.
Published: August 2002

The perforating pathway (PFP) intersects the corpus callosum perpendicularly at the midline in the dorsoventral axis. Therefore axons in either the PFP or the corpus callosum make different axonal guidance decisions in the same anatomical region of the developing cortical midline. The mechanisms underlying these axonal choices are not known. To begin to identify these guidance mechanisms, we characterized the development of these two pathways in detail. The development of the corpus callosum and its pioneering projections has been described elsewhere (Shu and Richards [2001] J. Neurosci. 21:2749–2758; Rash and Richards [2001] J. Comp. Neurol. 434:147–157). Here we examine the development, origins, and projections of axons that make up the PFP. The majority of axons within the PFP originate from neurons in the medial septum and diagonal band of Broca complex. These neurons project in a topographic manner to the cingulate cortex. In contrast to previous reports, we find that a much smaller projection originating from the cingulate cortex also contributes to this pathway. The pioneering projections of the PFP and the corpus callosum arrive at the corticoseptal boundary at around the same developmental stage. These findings show that ipsilaterally projecting PFP axons and contralaterally projecting callosal axons make distinct guidance decisions at the same developmental stage when they reach the corticoseptal boundary. J. Comp. Neurol. 436:411–422, 2001. © 2001 Wiley‐Liss, Inc.
Regenerating optic fibers correct large‐scale errors by random growth: Evidence from in vivo imaging
Authors: Dawson Amy J. , Meyer Ronald L.
Published: August 2002

Regenerating optic fibers in goldfish make large‐scale errors when they invade tectum and subsequently correct these to generate a projection with moderate retinotopic order by 1 month. The behavior of fibers underlying these extensive rearrangements is not well understood. To clarify this, we have imaged optic fibers in living adult goldfish at 2–4 weeks of regeneration. A small number of neighboring retinal ganglion cells were labeled with microinjections of DiI and imaged in the dorsal tectum with a cooled CCD camera on a fluorescence microscope for 5 to 8 hours. Nearly all fibers were simple unbranched processes and had endings that were highly dynamic showing both growth and retraction. Fibers from dorsal retina that normally innervate ventral tectum were frequently observed in dorsal tectum. These ectopic fibers oscillated more frequently between growth and retraction and retracted more often than ventral optic fibers. Like retinotopic fibers, ectopic fibers exhibited net growth but they showed no apparent directional preference toward their retinotopic position. In contrast, large errors along the anterior–posterior axis corresponding to nasal‐temporal retina were rare and there was no differential behavior that distinguished these fibers. J. Comp. Neurol. 434:40–55, 2001. © 2001 Wiley‐Liss, Inc.
Localization of the AMPA subunit GluR2 in the outer plexiform layer of goldfish retina
Authors: Klooster Jan , Studholme Keith M. , Yazulla Stephen
Published: August 2002

L‐glutamate, the photoreceptor neurotransmitter, depolarizes horizontal cells and OFF bipolar cells by ionotropic AMPA‐glutamate receptors. The AMPA‐receptor subunit (GluR4) is localized to dendrites of OFF bipolar cells in goldfish retina. Here, we used immunohistochemical techniques to identify AMPA‐receptor subunits on horizontal cell dendrites. A monoclonal antibody against rat GluR2, with high sequence homology to the recently cloned goldfish GluR2a receptor, was used for light‐ and electron‐microscopical immunocytochemistry. Light‐ and dark‐adapted retinas were analyzed, with no major difference in results. GluR2‐immunoreactivity (IR) was restricted to a narrow band in the outer plexiform layer, in which it appeared as bright dome‐shaped structures amidst numerous puncta. At the ultrastructural level, GluR2‐IR was found in horizontal cell dendrites that invaginated cones and rods. Dendrites of OFF bipolar cells were not labeled. GluR2‐IR was present mostly in horizontal cell dendrites that were the lateral elements of the triad, rather than in dendrites that were the central elements. In light‐adapted retinas, GluR2‐IR was found in many horizontal cell spinules. GluR2‐IR was observed, on occasion, in a mixed rod/cone (Mb) ON bipolar cell process that innervated rod spherules. Verification of the Mb ON bipolar cell was made by protein kinase C and metabotropic mGluR1α immunolabeling. The presence of GluR2‐IR in lateral elements suggests that lateral horizontal cell dendrites are postsynaptic to cones rather than only sites of feedback inhibition. All horizontal cell types express the GluR2 subunit, uniquely differentiating themselves from OFF bipolar cells that express the GluR4 subunit. This differentiation most likely has a major influence on the glutamate pharmacology and response kinetics of these cell types to glutamate. J. Comp. Neurol. 441:155–167, 2001. © 2001 Wiley‐Liss, Inc.
Book review: Principles of color reproduction
Authors: Arney Jonathan S.
Published: August 2002

Edited by John A.C. Yule, GATF Press, Sewickley, PA, 2001, 480 pp., $75
Object‐oriented analysis and design of the Message Passing Interface
Authors: Skjellum Anthony , Wooley Diane G. , Lu Ziyang , Wolf Michael , Bangalore Purushotham V. , Lumsdaine Andrew , Squyres Jeffrey M. , McCandless Brian
Published: August 2002

The major contribution of this paper is the application of modern analysis techniques to the important Message Passing Interface standard, work done in order to obtain information useful in designing both application programmer interfaces for object‐oriented languages, and message passing systems. Recognition of ‘Design Patterns’ within MPI is an important discernment of this work. A further contribution is a comparative discussion of the design and evolution of three actual object‐oriented designs for the Message Passing Interface ( MPI‐1SF ) application programmer interface (API), two of which have influenced the standardization of C++ explicit parallel programming with MPI‐2, and which strongly indicate the value of a priori object‐oriented design and analysis of such APIs. Knowledge of design patterns is assumed herein.

Discussion provided here includes systems developed at Mississippi State University (MPI++), the University of Notre Dame (OOMPI), and the merger of these systems that results in a standard binding within the MPI‐2 standard. Commentary concerning additional opportunities for further object‐oriented analysis and design of message passing systems and APIs, such as MPI‐2 and MPI/RT, are mentioned in conclusion.

Connection of modern software design and engineering principles to high performance computing programming approaches is a new and important further contribution of this work. Copyright © 2001 John Wiley & Sons, Ltd.
The COIL data mediator definition language
Authors: Och Christian , Osborne Richard M. , Todd John , King Roger
Published: August 2002

Modern persistent applications typically run on top of numerous (often hundreds) of distributed, heterogeneous databases. Integrating data from various data sources in order to provide uniform, homogeneous, and consistent access to the data from the underlying data sources while preserving the integrity and autonomy of preexisting data sources is a huge problem, especially in evolving environments. The main issue that a global information sharing system has to address is heterogeneity on all levels of the participating data sources: the data might be stored in heterogeneous data sources, using different data models and access/middleware technologies. Another major type of heterogeneity that has to be addressed by a global information sharing system is due to differences in the semantics of the data from the data source participating in the integration process. In particular, the resolution of potential conflicts due to structural and semantic heterogeneity of the integrated data is an essential part of the integration process performed by a data integration environment.

The COIL data mediator definition language supports the definition of the integration process and its semantics on a high level of abstraction. The language provides powerful language components which can be used to resolve potential conflicts due to structural and semantic heterogeneity, and to define the integration process in general. The semantics of a specific integration process are defined in a COIL data mediator definition (COIL program). The COIL compiler uses those specifications expressed in the COIL language to generate a standard Java object which captures the semantics of the integration process defined in the COIL mediator definition. The generated Java object is called a COIL data mediator. In general, a COIL data mediator is a user‐defined, customized object/component which can be used like any other normal object in the Java development environment. A COIL data mediator presents a well‐defined interface which may be used to access and configure the mediator at runtime. Therefore it is possible to change the data mediator's behavior and the semantics of the integration process in general at runtime. We present a detailed description of the COIL data mediator definition language and its language components, along with a detailed discussion of how COIL data mediators are used to overcome different heterogeneity problems. Copyright © 2001 John Wiley & Sons, Ltd.
Deferring elimination of design alternatives in object‐oriented methods
Authors: Aksit Mehmet , Marcelloni Francesco
Published: August 2002

While developing systems, software engineers generally have to deal with a large number of design alternatives. Current object‐oriented methods aim to eliminate design alternatives whenever they are generated. Alternatives, however, should be eliminated only when sufficient information to take such a decision is available. Otherwise, alternatives have to be preserved to allow further refinements along the development process. Too early elimination of alternatives results in loss of information and excessive restriction of the design space. This paper aims to enhance the current object‐oriented methods by modeling and controlling the design alternatives through the application of fuzzy‐logic‐based techniques. By using an example method, it is shown that the proposed approach increases the adaptability and reusability of design models. The method has been implemented and tested in our experimental CASE environment. Copyright © 2001 John Wiley & Sons, Ltd.
Bifurcation behaviour in parallel‐connected boost converters
Authors: Iu H. H. C. , Tse C. K. , Pjevalica V. , Lai Y. M.
Published: August 2002

This paper describes the bifurcation phenomena of a system of parallel‐connected d.c./d.c. boost converters. The results provide important information for the design of stable current sharing in a master–slave configuration. Computer simulations and experiments are performed to capture the effects of variation of some chosen parameters on the qualitative behaviour of the system. In particular, it is found that variation of some parameters leads to Neimark–Sacker bifurcation. Analysis is presented to establish the possibility of the bifurcation phenomena. Copyright © 2001 John Wiley & Sons, Ltd.
Compact CMOS implementation of a low‐power, current‐mode programmable cellular neural network
Authors: Ravezzi L. , Dalla Betta G.‐F. , Setti G.
Published: August 2002

We report on the design and characterization of a full‐analog programmable current‐mode cellular neural network (CNN) in CMOS technology. In the proposed CNN, a novel cell‐core topology, which allows for an easy programming of both feedback and control templates over a wide range of values, including all those required for many signal processing tasks, is employed. The CMOS implementation of this network features both low‐power consumption and small‐area occupation, making it suitable for the realization of large cell‐grid sizes. Device level and Monte Carlo simulations of the network proved that the proposed CNN can be successfully adopted for several applications in both grey‐scale and binary image processing tasks. Results from the characterization of a preliminary CNN test‐chip (8×1 array), intended as a simple demonstrator of the proposed circuit technique, are also reported and discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Low‐voltage rail‐to‐rail switched buffer topologies
Authors: Ferri Giuseppe , Baschirotto Andrea
Published: August 2002

This paper presents some CMOS rail‐to‐rail low‐voltage (1.2 V) switched buffer topologies, to be used as input stages in switched‐opamp circuits. The main buffer is based on the use of an op‐amp featuring rail‐to‐rail input and output swing with constant transconductance over the input common mode voltage. The designed buffer exhibits a total harmonic distortion of about ‐61 dB for 5 MHz clock frequency with 2 Vppinput amplitude. Its characteristics have been compared with those of other rail‐to‐rail switched buffers, based on the main CMOS OTA (simple, symmetrical, Miller), showing good distortion even at frequencies in the MHz range and satisfying the requirements for the series switches. Copyright © 2001 John Wiley & Sons, Ltd.
A mixed‐mode polynomial‐type CNN for analysing brain electrical activity in epilepsy
Authors: Laiho Mika , Paasio Ari , Kananen Asko , Halonen Kari
Published: August 2002

In this paper, a mixed‐mode polynomial‐type cellular neural network (CNN) for analysing brain electrical activity in epilepsy is presented. The principles and design characteristics of this application are overviewed. The main difference of the requirements of this application compared to conventional CNN realizations is that in addition to linear, cells are also coupled with polynomial‐type couplings. A mixed‐mode CNN is shown to be suitable for the realization of a polynomial‐type CNN in the brain electrical activity analysis application. In a mixed‐mode CNN multiplication is done in analog domain, whereas the integration and storage are digital. Suitability of different integration methods for cell level realization are studied and cell and network level design of a mixed‐mode CNN is described. First‐, second‐ and third‐order polynomial feedback terms are included in the cell and Heun's integration method is used. In order to reduce the cell count, the array is designed so that it can process input data that has been divided into blocks. The whole input data is stored in parallel with the cells so that all input/output operations during processing are local. Cell structure is shown along with register connections between edge cells of the network. Analog power consumption and computing speed are estimated by HSPICE simulations using 0.25 µm digital CMOS process parameters. The die area of a network with 2×72 cells with 36 layers in each was determined by drawing the layout. Copyright © 2002 John Wiley & Sons, Ltd.
Some new analogic CNN algorithms for PCB quality control
Authors: Hidvégi Timót , Szolgay Péter
Published: August 2002

In the production of a PCB different errors may occur. The detection of these errors is time consuming and there is an increasing need to use a 100% quality control in production. New analogic CNN algorithms were developed to detect the short circuit and the misalignment errors. These analogic algorithms were tested with software simulator, 20×22 CNN‐UM chip and 64×64 CNN‐UM chip by using ALADDIN System. Copyright © 2002 John Wiley & Sons, Ltd.
Androgen receptor expression and DNA content of paraffin‐embedded archival human prostate tumors
Authors: Adiga Satish Kumar , Andritsch Ilia , Rao Ravikala Vittal , Krishan Awtar
Published: August 2002

Background: Androgen receptors (AR) are expressed in human prostate cells and immunohistochemistry has been used for qualitative analysis of AR expression in prostate tumor cells. Quantitative and multiparametric analysis of receptor expression could be of diagnostic and prognostic value in the management of patients on antiandrogen therapy. Multiparametric flow cytometric methods have been developed for analysis of hormone receptor expression and DNA content in nuclei isolated from formalin‐fixed/paraffin‐embedded human solid tumors. The present study was undertaken for analysis of AR expression and DNA content in archival human prostate tumors. Methods: AR expression and DNA content were measured in nuclei isolated by enzyme digestion from thick sections cut from 51 paraffin‐embedded human prostate tumors. AR expression in different subpopulations was studied by gated analysis. The relationship among AR activity, DNA content, and histopathological grade was analyzed. Results: Distinct aneuploid populations were observed in 23% of tumors examined. AR activity was observed in all the specimens and the percentage of AR‐ positive nuclei in the 48 samples analyzed was <10% (n = 4), 11–50% (n = 39), and >51% (n = 5). Tumor subpopulations with aneuploid DNA content had higher AR expression (percent AR‐positive cells and mean log fluorescence) than the diploid subpopulations. No strong correlation was seen between AR expression and histopathological grade of the tumors. Conclusions: Flow cytometric analysis of archival prostate tumor can be used for rapid determination of aneuploid DNA content and AR expression in subpopulations of nuclei isolated from formalin‐fixed/paraffin‐embedded prostate tumor blocks. Cytometry (Clin. Cytometry) 50:25–30, 2002. © 2002 Wiley‐Liss, Inc.
Nonparametric discriminant analysis of phytoplankton species using data from analytical flow cytometry
Authors: Collins G.S. , Krzanowski W.J.
Published: August 2002

Background

Analytical flow cytometry (AFC) provides rapid and accurate measurement of particles from heterogeneous populations. AFC has been used to classify and identify phytoplankton species, but most methods of discriminant analysis of resulting data have depended on normality assumptions and outcomes have been disappointing.

Methods and Results

In this study, we consider nonparametric methods based on density estimation. In addition to the familiar kernel method, methods based on wavelets are also implemented. Full five‐dimensional wavelet estimation proves to be computationally prohibitive with current workstation power, so we employ projection pursuit for reduction of dimensionality. AFC typically produces very large samples, so we also investigate data simplification through binning. Further modifications to the discrimination strategy are suggested by specific features of phytoplankton data, namely, a hierarchical group structure, the possible presence of many groups, and the likelihood of encountering an aberrant group in a test sample.

Conclusions

We apply all the resultant procedures to appropriate subsets of a very large data set, demonstrate their efficacy, and compare their error rates with those of more conventional methods. We further show that incorporation of the specific features of phytoplankton data into the analysis leads to improved results and provides a general framework for analysis of such data. Cytometry 48:26–33, 2002. © 2002 Wiley‐Liss, Inc.
Measured average cell rate‐based congestion avoidance scheme
Authors: Choi Hyun M. , Nygard Kendall E. , Perrizo William
Published: August 2002

Techniques for congestion control of available bit‐rate (ABR) traffic in ATM (asynchronous transfer mode) networks remain an important issue. Several congestion control schemes have been proposed to adjust the cell rates of sources with a modified or mean allowed cell rate. To make these schemes work effectively in practice, the modified or mean allowed cell rate must converge under all conditions. However, it is not easy to obtain an accurate value, and an inaccurate value could result in network performance degradation such as severe oscillations and considerable unfairness. Therefore, we propose a measured average cell rate‐based congestion avoidance for ABR traffic in ATM networks. The scheme has high throughput and achieves shorter queue lengths without congestion. With measured average cell rate, the scheme provides fast convergence to a start‐up virtual connection (VC) and rate of equalization from different initial conditions of the sources. Thus, this scheme provides better fairness among connections. Copyright © 2001 John Wiley & Sons, Ltd.
A multiple access protocol with explicit and implicit reservation
Authors: Davoli F. , Maryni P. , Nobile C.
Published: August 2002

A new version of a MAC‐level protocol is introduced and investigated, operating in a cellular environment, where a base station co‐ordinates mobile users within each cell. The channel multiplexing structure is based on time division, and the slots in each frame are dynamically assigned to the users and their service classes by the cell base station. Decisions are taken on the basis of binary channel feedback information (collision/no collision), by assuming independence in the presence of packets at the mobile stations, and aim at maximizing the one‐step throughput in the current frame. The frame is divided into two periods: the first (short) one contains a number of minislots, equal to the number of ‘real’ slots (i.e. those capable of containing a fixed size packet) of the second part. At the beginning of the frame, the access rights are computed and broadcast to the users; the enabled stations that have a packet to transmit respond, by sending a short burst that contains their ID in a minislot. This most recent feedback is used at the base station to update the parameters of the decision algorithm, which is then re‐applied to yield the final access rights for the second part of the frame. The performance of the scheme is analysed by simulation in the presence of mixed voice and data traffic, and compared with those of a reservation random access protocol using the same algorithm in a single‐phase fashion (RRA‐ISA) and PRMA. Copyright © 2001 John Wiley & Sons, Ltd.
A simple, scalable and provably stable explicit rate computation scheme for flow control in communication networks
Authors: Aweya James , Ouellette Michel , Montuno Delfin Y.
Published: August 2002

This paper describes fast rate computation (FASTRAC), an explicit rate flow control algorithm for available bit rate (ABR) traffic. Using digital control theory, we develop a simple rate controller for the ABR flow control process. We prove that the controller is stable, fair to all participating sources and configurable with respect to responsiveness. The analysis presented shows that stability of the flow control process depends primarily on two factors, the control update rate and the feedback delay. The implementation of the proposed algorithm is much simpler than other fair rate allocation algorithms. The proposed algorithm demonstrates the ability to scale with speed, distance, different feedback delays, number of users, and number of nodes while remaining robust, efficient, and fair under stressing and dynamic traffic conditions. Copyright © 2001 John Wiley & Sons, Ltd.
A speech coder for PC multimedia net‐to‐net communication
Authors: Parvez Shahid , Elshafei‐Ahmed M.
Published: August 2002

The paper presents a speech coding algorithm for operation at 11025 samples/s. The coder provides improved speech quality and compatibility with the MS‐Windows multimedia environment. The coding algorithm has been developed by adapting the ITU G729 and enhancing it with some recent developments in the medium band coding. The coder operates over a band of frequencies ranging from 20 to 5400 Hz at a bit rate of 8.9 kbit/s. Application of this coder includes intranet VoIP, voice chatting, multimedia communications, and voice archiving. Copyright © 2001 John Wiley & Sons, Ltd.
Distributed object‐oriented switching system software platform design
Authors: Sunaga Hiroshi , Shina Hideki , Inamori Hisayoshi , Nakamura Ryoichi
Published: August 2002

Key technologies are presented and evaluated for establishing a distributed object‐oriented switching system platform. This platform is based on CORBA, which can enhance software productivity and system scalability and is thus widely used in the information technology field. Conditions and requirements specific to switching systems, such as very high‐performance and non‐stop operation, are analysed and mapped to the main elements of CORBA. How to deploy and bind objects so as to minimize the processing load is clarified. Mechanisms that guarantee system reliability (saving calls in service when a system failure occurs and avoiding the spread of faults) are also presented. Evaluation of the number of dynamic program steps for systems using fully compliant CORBA, improved CORBA, and a proprietary high‐speed object‐request broker (ORB) shows that constructing a communication switching system by using the high‐speed ORB approach is sufficient, but CORBA‐compliant approaches should be used to provide an interoperable interface for communicating with external compliant systems. Copyright © 2001 John Wiley & Sons, Ltd.
IP router architectures: an overview
Authors: Aweya James
Published: August 2002

In the emerging environment of high performance IP networks, it is expected that local and campus area backbones, enterprise networks, and internet service providers (ISPs) will use multigigabit and terabit networking technologies where IP routers will be used not only to interconnect backbone segments but also to act as points of attachments to high performance wide area links. Special attention must be given to new powerful architectures for routers in order to play that demanding role. In this paper, we identify important trends in router design and outline some design issues facing the next generation of routers. It is also observed that the achievement of high throughput IP routers is possible if the critical tasks are identified and special purpose modules are properly tailored to perform them. Copyright © 2001 John Wiley & Sons, Ltd.
Comparison of different congestion control strategies for low priority controllable traffic in packet switched backbone networks
Authors: Pulakka K. , Harju J.
Published: August 2002

It is expected that a significant part of the data flows of future multi‐service packet switched backbone networks will use low priority, non‐real‐time data transmission services of the networks. The common benefit for both user applications and network operators is that the data flows of the low priority services could use the free capacity of the networks, after the load of higher priority data flows. Congestion control methods are needed for these low priority data flows to reach an optimal utilisation level of the networks, high throughput and low packet loss ratios. This kind of low priority data transmission service which adjusts the data rates of the data flows according to the data rate changes of higher priority data flows, but does not guarantee any specific service for these data flows, is called a controlled load service. In this paper, we have compared the performance, efficiency and scalability of four different congestion control methods designed for the controlled load service. Two of these methods were based on very simple congestion control algorithms and the other two used relatively complex control algorithms based on control methods utilising computational intelligence. The principal aim of this study was to research how remarkable were the effects that the different complexities of the congestion control methods had on the achieved level of service. The simulation tests indicate that the complexity of the methods clearly affects the performance and efficiency of the methods. Copyright © 2001 John Wiley & Sons, Ltd.
An enhanced explicit rate algorithm for ABR traffic control in ATM networks
Authors: Long Y. H. , Ho T. K. , Rad A. B.
Published: August 2002

A high performance, low computational complexity rate‐based flow control algorithm which can avoid congestion and achieve fairness is important to ATM available bit rate service. The explicit rate allocation algorithm proposed by Kalampoukaset al.is designed to achieve max–min fairness in ATM networks. It has several attractive features, such as a fixed computational complexity ofO(1) and the guaranteed convergence to max–min fairness. In this paper, certain drawbacks of the algorithm, such as the severe overload of an outgoing link during transient period and the non‐conforming use of the current cell rate field in a resource management cell, have been identified and analysed; a new algorithm which overcomes these drawbacks is proposed. The proposed algorithm simplifies the rate computation as well. Compared with Kalampoukas's algorithm, it has better performance in terms of congestion avoidance and smoothness of rate allocation. Copyright © 2001 John Wiley & Sons, Ltd.
Fite stain positivity in Rhodococcus equi: Yet another acid‐fast organism in respiratory cytology—a case report
Authors: Echeverri Carolina , Matherne Jason , Jorgensen James H. , Fowler Larry J.
Published: August 2002

Rhodococcus equi is an aerobic Gram‐positive and acid‐fast coccobacillus that may cause cavitary pneumonia in immunocompromised hosts such as HIV‐infected patients. Numerous Grocott's methenamine silver (GMS)‐positive organisms were initially noted on the direct smear; a minor number of acid‐fast organisms were seen in the Thin‐Prep® slide. Since the abundant mucous material with the attached organisms seen in conventional smears may be lost in liquid‐based preparations, more sensitive stains such as Fite, as well as a more diligent search for organisms, is needed. This case illustrates the importance of careful selection and evaluation of special stains in sputum specimens. Diagn. Cytopathol. 24:244–246, 2001. © 2001 Wiley‐Liss, Inc.
Significance of histiocytes in cervical smears from peri/postmenopausal women
Authors: Tambouret Rosemary , Bell Debra A. , Centeno Barbara A.
Published: August 2002

Histiocytes in cervicovaginal smears from peri‐ or postmenopausal women have been viewed as a potential indicator of endometrial neoplasia, but recent studies have refuted that view. This study further defines the clinical significance of such findings. All cervical smears were selected from women (≥50 yr) in whom the presence of histiocytes was mentioned; pertinent clinical history, follow‐up information, and selected slides were reviewed. Among 105,225 total cervicovaginal smears from a 3.5‐yr period, 106 smears from 103 women were identified. Forty‐two patients (41%) were on hormone replacement therapy (2 on tamoxifen), and 23 (22.3%) patients experienced vaginal bleeding, all of whom had biopsy or cytology follow‐up. Ten (9.6%) patients had no follow‐up, 35 (32%) had repeat smears only, and 58 (56.3%) had endometrial/endocervical sampling. In 28 patients, the index smear was categorized as other than within normal limits or benign cellular changes; of these, 24 had subsequent tissue sampling and 4 had cytology follow‐up. Of the patients with tissue sampling, 51 (84%) had benign findings (including polyps), 2 (3.5%) had hyperplasia, and 5 (10%) had adenocarcinoma. All 5 patients with adenocarcinoma had endometrial glandular cells on the smear, and 4 had vaginal bleeding. One patient with hyperplasia had vaginal bleeding, and the other was on tamoxifen and had endometrial glandular cells on the smear. None of the patients having only histiocytes on their smears and no clinical symptoms or risk factors had endometrial adenocarcinoma or hyperplasia. These findings support the conclusion that the presence of histiocytes alone on cervicovaginal smears from peri‐ or postmenopausal women is nonspecific and of no major clinical significance in the absence of other clinical or cytologic findings. Diagn. Cytopathol. 24:271–275, 2001. © 2001 Wiley‐Liss, Inc.
Xanthine‐analog, KMUP‐2, enhances cyclic GMP and K+ channel activities in rabbit aorta and corpus cavernosum with associated penile erection
Authors: Lin Rong‐Jyh , Wu Bin‐Nan , Shen Kuo‐Pyng , Huang Chun‐Hsiung , Liu Zee‐Ing , Lin Chiu‐Yin , Cheng Chang‐Jenq , Chen Ing‐Jun
Published: August 2002

The pharmacological properties of KMUP‐2 were examined in isolated rabbit aorta and corpus cavernosum smooth muscle (CCSM). KMUP‐2 caused relaxations that were attenuated by removed endothelium, high K+, and pretreatment with the soluble guanylate cyclase (sGC) inhibitors methylene blue (10 μM) and ODQ (1 μM), a NOS inhibitor, L‐NAME (100 μM), a K+ channel blocker TEA (10 mM), a KATP channel blocker glibenclamide (1 μM), a voltage‐dependent K+ channel blocker 4‐AP (100 μM), and the Ca2+‐dependent K+ channel blockers apamin (1 μM) and charybdotoxin (ChTX, 0.1 μM). The relaxant responses of KMUP‐2 (0.01, 0.05, 0.1 μM) together with a PDE inhibitor, IBMX (0.5 μM), had additive effects on rabbit aorta and CCSM. Additionally, KMUP‐2 (100 μM) also affected cGMP metabolism, due to its inhibiting activity on PDE in human platelets. KMUP‐2 (0.1–100 μM) further induced an increase of intracellular cGMP levels in the primary cultured rabbit aortic and CCSM cells. These increases in cGMP content were abolished in the presence of methylene blue (100 μM) and ODQ (10 μM). Obviously, the relaxant effects of KMUP‐2 on rabbit isolated tissues are more sensitive in CCSM than in aorta. Moreover, KMUP‐2 also stimulated NO/sGC/cGMP pathway and subsequent elevation of cGMP by blockade of PDE and enhanced opening of K+ channels in rabbit aorta and CCSM. KMUP‐2 (0.2, 0.4, 0.6 mg/kg), similar to KMUP‐1 and sildenafil, caused increases of intracavernous pressure (ICP) and duration of tumescene (DT) in a dose‐dependent manner. It is concluded that both the increases of cGMP and the opening activity of K+ channels play prominent roles in KMUP‐2‐induced aortic smooth muscle and CCSM relaxation and increases of ICP in rabbits. Drug Dev. Res. 55:162–172, 2002. © 2002 Wiley‐Liss, Inc.
Study of aggregation of platelets lacking the P2Y1 receptor
Authors: Fabre Jean‐Etienne , King Brian F. , Koller Beverly H.
Published: August 2002

The recent generation of mice deficient for the P2Y1 receptor has allowed us to directly examine the contribution of this nucleotide receptor in ADP‐induced aggregation both in isolated platelets and in vivo thrombosis. Studies utilizing the P2Y1‐deficient platelets clearly demonstrated that the P2Y1 receptor alone is not sufficient for describing the various effects induced by ADP on platelets. While no increase in intracellular calcium was observed in the platelets lacking P2Y1, the ability of ADP to decrease intracellular cAMP was unaltered. An additive and unexpected observation is the partial aggregation induced by exposure of P2Y1‐deficient platelets to high levels of ADP. This suggests that additional ADP receptors are expressed by platelets and that these receptors can induce partial aggregation of platelets in the absence of measurable changes in intracellular calcium. This review summarizes the recent advances in understanding the mechanisms involved in the platelet response to ADP and examines various hypotheses that attempt to explain the pathway leading to partial aggregation of P2Y1 platelets in response to ADP. Drug Dev. Res. 52:150–155, 2001. © 2001 Wiley‐Liss, Inc.
Role of mitogen‐activated protein kinase cascades in P2Y receptor‐mediated trophic activation of astroglial cells
Authors: Neary Joseph T. , Lenz Guido , Kang Yuan , Rodnight Richard , Avruch Joseph
Published: August 2002

The trophic actions of extracellular nucleotides and nucleosides on astroglial cells in the central nervous system may be important in development as well as injury and repair. Here we summarize recent findings on the signal transduction mechanisms and gene expression that mediate the trophic effects of extracellular ATP on astrocyte cultures, with a particular emphasis on mitogenesis. Activation of ATP/P2Y receptors leads to the stimulation of mitogen‐activated protein kinase (MAPK) cascades, which play a crucial role in cellular proliferation, differentiation, and survival. Inhibition of ERK and p38, members of two distinct MAPK cascades, interferes with the ability of extracellular ATP to stimulate astrocyte proliferation, thereby indicating their importance in mitogenic signaling by P2Y receptors. Signaling from P2Y receptors to ERK involves phospholipase D and a calcium‐independent protein kinase C isoform, PKC; this pathway is independent of the phosphatidylinositol‐phospholipase C / calcium pathway which is also coupled to P2Y receptors. Pharmacological studies suggest that astrocytes may express an as‐yet uncloned P2Y receptor that recruits a novel MEK activator in the ERK cascade. Extracellular ATP can also potentiate fibroblast growth factor (FGF)‐2‐induced proliferation, and studies on interactions between ATP and FGF‐2 signaling pathways have revealed that although ATP does not activate cRaf‐1, the first protein kinase in the ERK cascade, it can reduce cRaf‐1 activation by FGF‐2. As intermediate levels of Raf activity stimulate the cell cycle, the partial inhibition of FGF‐induced Raf activity by ATP may contribute to the enhancing effect of ATP on FGF‐2‐induced astrocyte proliferation. Activation of P2Y receptors also leads to nuclear signaling, and the use of DNA arrays has shown that treatment of astrocytes with extracellular ATP results in the up‐ and downregulation of a number of genes; studies to determine which of these genes are regulated by MAPKs are now in progress. Elucidation of the components of MAPK pathways linked to P2Y receptors and subsequent changes in gene expression may provide targets for a new avenue of drug development aimed at the management of astrogliosis which occurs in many types of neurological disorders and neurodegeneration. Drug Dev. Res. 53:158–165, 2001. Published 2001 Wiley‐Liss, Inc.
Analgesic efficacy of the combination metamizol+morphine after subchronic treatment in rats
Authors: Ramírez Adriana Miriam Domínguez , Delgadillo Gloria Patricia Hernández , Martínez Rosa Ventura , Reval Ma. Irene Díaz , López‐Muñoz Francisco Javier
Published: August 2002

In the present study, the analgesic efficacy and the possible development of tolerance produced by the combination metamizol+morphine (562.3:5.6 mg/kg) during subchronic treatment (6 and 12 days) in arthritic rats using the PIFIR model was evaluated. This combination of metamizol+morphine produced the maximum analgesic efficacy (AUCE = 353.4 ± 24.7 au) when compared with morphine 5.6 mg/kg (AUCE = 196.6 ± 35.3 au), metamizol 562.3 mg/kg (AUCE = 262.8 ± 10.2 au), and morphine 10 mg/kg (AUCE = 316.6 ± 31.0 au) given in a single dose. The results were essentially the same when the combination was administered for 6 (AUCE = 325.4 ± 13.1 au) or 12 days (AUCE = 354.5 ± 9.6 au). In addition, the duration of the effect was longer when the combination metamizol+morphine was administered either in single or subchronic treatment. Development of tolerance to the analgesic effect was observed after 6 and 12 days of morphine administration. However, the analgesic effect produced by the metamizol+morphine combination remained constant (near 100%) during both subchronic treatments. The present data demonstrate that metamizol significantly attenuates the development of tolerance to morphine. The mechanism involved in this effect of metamizol remains to be determined. Drug Dev. Res. 51:260–267, 2000. © 2001 Wiley‐Liss, Inc.