bluuebunny/crossref_metadata_2025_split huggingface dataset:
Group communication in multichannel networks with staircase interconnection topologies
Authors: McKinley P. K. , Liu J. W. S. 
Published: October 2004

Recently, multichannel networks composed of several parallel, medium-speed channels multiplexed on a single high-speed medium have been proposed as a practical way to harness the high bandwidths of optical fibers. In order to limit the cost of network interfaces, a partially-connected multichannel network allows each node access to only a proper subset of the channels, its channel set. Staircase interconnection topologies constitute a family of partially-connected multichannel networks in which every node can still send messages directly to every other node.
Group-based computer applications composed of cooperative processing entities are proliferating. The communication among processes in group-based applications typically involves multiple destinations and is often symmetric and temporally local. In this paper, we investigate the problem of supporting group communication in staircase multichannel networks. We analyze those properties of staircase topologies that benefit temporally local multicast communication. We then develop an adaptive protocol that permits nodes to dynamically change their channel sets. These changes are based on recent network traffic history, thus enabling the topology to conform to network traffic patterns and, specifically, group locality. Analytical and simulation results are presented.
Derivation of axiomatic definitions of programming languages from algorithmic definitions
Authors: Allen C David 
Published: October 2004

Language definitions by abstract interpreters are appropriate to the design and development of a language. Axiomatic definitions are more appropriate to proving program properties and verification of compilers. The proof methods of Manna and Ashcroft can be applied to an algorithmic definition in, e.g. the Vienna Definition Language to deduce theorems which constitute an axiomatic definition of precisely the same language.
The process and techniques are explained, and illustrated on a simple language of assignment statements.
Recursive definitions of partial functions and their computations
Authors: Cadiou J. M. , Manna Zohar 
Published: October 2004

The object of this paper is to present a syntactic and semantic model for recursive definitions, and to study the relation between their computed functions and their fixpoints. The recursive definitions that we consider are syntactic generalizations of those introduced in [2] by Kleene and in [5] by McCarthy.
Each recursive definition yields two classes of fixpoint partial functions (“fixpoints over D υ {ω}” and “fixpoints over D”), and a class of computed partial functions obtained by applying different computation rules to the recursive definition. In this work we first describe the relations between the computed functions and the fixpoints over D υ {ω} (Theorem 1), and between the computed functions and the fixpoints over D (Theorem 2). Our main interest is in the class of fixpoints (over D or D υ {ω}) which are also computed functions of the recursive definition.
The correctness of numerical algorithms
Authors: Hull T. E. , Enright W. H. , Sedgwick A. E. 
Published: October 2004

Structured programming and the use of assertions are two basic techniques needed in organizing proofs of the correctness of algorithms. These techniques can be combined with theorems in numerical analysis to produce proofs of the correctness of numerical algorithms.
A simple algorithm for finding the sum of n numbers is first used to show how assertions can be modified to take account of the effect of roundoff. A so-called backward error analysis then leads to a proof that the algorithm is correct in the sense that it produces exact results for slightly perturbed problems. Alternative points of view are possible, and one of the distinguishing features of numerical algorithms is that there usually are a number of different senses in which one might want to prove them correct.
Two other more substantial algorithms, one for solving linear algebraic equations and one for solving differential equations, are then used to show how structured programming and the use of assertions can be combined with error analyses of fairly complicated numerical processes to provide proofs of correctness. One of these algorithms involves roundoff error while the other is affected primarily by truncation error.
Internetting between VAX and Apollo ring network
Authors: Chu N. N. Y. 
Published: October 2004

Specifications for a network design to connect the Apollo DOMAIN network with the VAX system are discussed in this paper. Three networking approaches were considered which represent three distinct chronological stages in the evolution of computer communications. Based on a comparison of data transfer rate and the installation cost among these three alternatives, the LAN, represented by the Ethernet, was recommended as the connecting hardware.
The OSI Reference Model was used as a starting basis to discuss protocol issues to be built for the chosen LAN. Of particular interest are the transport, presentation, and application layers. The transport layer was designed to perform functions of the network and session layers in the OSI model. The presentation layer incorporated a text mapping algorithm to convert incompatible characters in filenames created on the VAX versus those on the Apollo. The application layer was designed with the capability to send and receive files between these two systems.
Office information and telecommunications
Authors: Shurig Russ 
Published: October 2004

In order to understand the relationship of office information to office products and to telecommunications, the category of information media must be introduced. Voice, image, text and data information media can be related to one another, to computer and telecommunications technologies and to the needs of different types of workers.
The purpose of business offices, however, is not usually primarily information, computing or telecommunications, but rather knowledge, products and useful work. The information categories including media, transfer, products and work can be related to one another for a better understanding of office information products and telecommunications and in order to predict their future.
A message handling system for public networks
Authors: Nakayama Toshihiko , Shimazu Yoshihiro , Haruta Katsuhiko 
Published: October 2004

As a message handling system installed in the public communication networks, SSC (Store and Processing Service Control Facility) provides convenient communication processing services using storage and conversion technologies. The SSC conversion facilities, including media conversion from teletex codes to facsimile image, increase the communicable terminal range. Mailbox services, using four different kinds of personal Message Boxes in the SSC, bring about much benefit to personal communications. The SSC service requesting procedures facilitate multi-address delivery, timed delivery and automatic conversions. The SSC is a prototype which realizes the Message Handling Systems being studied in CCITT. The system is under developmental research in the NTT Laboratory.
This paper describes the basic SSC development concept, the relationship to the CCITT standard, the SSC service outline and the field trial system configuration.
Establishment communication systems
Authors: Kümmerle K. 
Published: October 2004

In the sixties and early seventies, major activities in networking were focused on private and public data networks using either circuit and packet-switching technology or integrating both switching methods into a single network. In this time frame, manufacturers of main frames defined and implemented network architectures, ISO started work on the reference model of the Open-System Interconnect Architecture, and CCITT recommended the X-series of interfaces.
Local-area communication networks (LAN's) represent a comparatively new field of activity which can be viewed as an extension to data networks for making high-speed packet-switching services available to the in-house domain. Currently, much research and development work is being pursued in this field, both at universities and in industry. The term local refers to communication on the users' premises, i.e., within a building or among a cluster of buildings.
Local data and voice communication are not new. A typical example of a system widely used today for local data communication between hosts and display terminals is a star configuration where the terminals are attached to control units tightly coupled to a processor via I/O channels. The necessary terminal control functions are provided in the control unit and shared among a set of terminals. The most widely used local communication system is the Private Automatic Branch Exchange (PABX). Most PABX's installed today are optimised for real-time voice, and use analog technology.
Link access blocking in very large multi-media networks
Authors: Labourdette Jean-François , Hart G. 
Published: October 2004

This paper is concerned with performance models and approximations for very large, multi-media networks. Blocking is the traditional performance measure in circuit-switched networks, and will remain as such in multi-rate circuit-switched networks. It is also considered a likely performance measure candidate for resource management and dimensioning in broadband fast packet-switched networks, operated under virtual circuit mode.
To gain some insight into network-wide blocking phenomena, we study in this paper the basic building block of any network, a single link. Multi-media traffic calls with Poisson arrivals, arbitrarily distributed service times, and different bandwidth requirements (in number of circuits), are offered to a system (link) of finite capacity. A call is rejected when the sharing policy doesn't allow it to be accommodated by the system.
Under complete sharing policy, an aggregate state describing the number of occupied circuits is shown to exhibit a product form solution in steady state, when the capacity and traffic intensities become very large asymptotically. This structural property leads to the main result of this paper, an approximation which reduces the computation of the blocking probabilities for the different classes of traffic to the evaluation of a single Erlang formula and the determination of the root of a monotonous polynomial function.
We provide comparison curves of the exact blocking probabilities and the approximations for some examples with 3 classes of traffic.
Protocol implementation on the Nectar Communication Processor
Authors: Cooper E. C. , Steenkiste P. A. , Sansom R. D. , Zill B. D. 
Published: October 2004

We have built a high-speed local-area network called Nectar that uses programmable communication processors as host interfaces. In contrast to most protocol engines, our communication processors have a flexible runtime system that supports multiple transport protocols as well as application-specific activities. In particular, we have implemented the TCP/IP protocol suite and Nectar-specific communication protocols on the communication processor. The Nectar network currently has 25 hosts and has been in use for over a year.
The flexibility of our communication processor design does not compromise its performance. The latency of a remote procedure call between application tasks executing on two Nectar hosts is less than 500 μsec. The same tasks can obtain a throughput of 28 Mbit/sec using either TCP/IP or Nectar-specific transport protocols. This throughput is limited by the VME bus that connects a host and its communication processor. Application tasks executing on two communication processors can obtain 90 Mbit/sec of the possible 100 Mbit/sec physical bandwidth using Nectar-specific transport protocols.
Differentiation of Tr1 cells by immature dendritic cells requires IL-10 but not CD25+CD4+ Tr cells
Authors: Levings Megan K. , Gregori Silvia , Tresoldi Eleonora , Cazzaniga Sabrina , Bonini Chiara , Roncarolo Maria Grazia 
Published: October 2004

Abstract
Dendritic cells (DCs) are specialized antigen-presenting cells that monitor the antigenic environment and activate naive T cells. The role of DCs is not only to sense danger but also to tolerize the immune system to antigens encountered in the absence of maturation/inflammatory stimuli. Indeed, if a naive T cell encounters its antigen on immature DCs (iDCs), it may differentiate into a T-regulatory (Tr) rather than a T-effector cell. However, little is known about the mechanisms by which iDCs differentiate Tr cells. We developed a standardized and highly reproducible protocol to differentiate Tr cells by repetitive exposure of naive peripheral blood CD4+ T cells to allogeneic iDCs. The resultant Tr cells are phenotypically and functionally identical to type 1 Tr (Tr1) cells because their generation requires production of IL-10 by iDCs, and they suppress T-cell responses through an interleukin-10 (IL-10)– and a transforming growth factor β (TGF-β)–dependent mechanism. In addition, Tr1 cells induced by iDCs do not require the presence of CD4+CD25+ Tr cells for their generation, nor do they express high constitutive levels of CD25 or the transcription factor FoxP3. Thus, iDCs can drive the differentiation of Tr1 cells and can be used to generate large numbers of alloantigen-specific Tr1 cells for clinical use as a cellular therapy to restore peripheral tolerance.
The birth of Emerging Themes in Epidemiology: a tale of Valerie, causality and epidemiology
Authors: Tam Clarence C 
Published: October 2004

AbstractEmerging Themes in Epidemiology (ETE) is a new, online, Open Access peer-reviewed journal. The Journal is unique in that it was conceived and is managed by research degree students in epidemiology and related public health fields. The Journal's management is overseen by its Editor-in-Chief and Associate Faculty Editors, all of whom are senior members of faculty. ETE aims to encourage debate and discussion on the theoretical, methodological and practical aspects of epidemiologic research and practice. In addition, ETE is dedicated to the promotion of Open Access publication and the training of research students in the scientific publishing process. This editorial, to coincide with the launch of ETE, sets out the Journal's philosophy and aims. Epidemiology is a rich and innovative science that has much to gain from broader discussion of the causal frameworks that underpin it. ETE aims to be a major forum for such discussion.
Topology Studies of the Chloroplast Protein Import Channel Toc75
Authors: Sveshnikova N. , Grimm R. , Soll J. , Schleiff E. 
Published: October 2004

Abstract
A major goal in understanding protein transport across membranes is the investigation of the structure and regulation of the translocon subunits. We analysed Toc75, a pore-forming subunit of the translocon of the outer envelope of chloroplasts. Toc75 was over-expressed and reconstituted into liposomes. Immunoprecipitation of liposome-reconstituted Toc75 indicates an Nin-Cin orientation of Toc75. Limited proteolytic digestion of Toc75 present in outer envelope vesicles with specific proteases combined with amino acid sequencing was used to study the topology of Toc75. Finally, computer modelling based on known protein structures indicates that Toc75 traverses the outer envelope with 16 amphiphilic beta sheets and the topology model is presented.
Different Signaling Pathways Are Involved in CCKB Receptor-Mediated MAP Kinase Activation in COS-7 Cells
Authors: Zieger M. , Oehrl W. , Wetzker R. , Henklein P. , Nowak G. , Kaufmann R. 
Published: October 2004

Abstract
Recently, the involvement of the MAP kinase ERK in mitogenic signaling of cholecystokininB (CCKB) receptors has been shown. However, the intracellular effector systems involved in this signaling pathway are poorly defined. In this study, we used COS-7 cells transiently transfected with the human CCKB receptor to investigate cholecystokinin-induced MAP kinase activation. CCK-8 induced activation of ERK2 which is associated with its phosphorylation and localization in the nucleus. The CCK-8-dependent ERK stimulation is sensitive to wortmannin an inhibitor of phosphoinositide 3-kinases (PI3Ks) indicating the involvement of PI3K activity. To identify the PI3K species involved in mitogenic signaling of the CCKB receptor several dominant-negative mutants of PI3K regulatory and catalytic subunits were transiently expressed. Surprisingly, different catalytically inactive mutants of the G protein-sensitive PI3Kγ did not affect ERK stimulation induced by CCK, whereas a dominant-negative mutant of the regulatory p85 subunit induced significant inhibition of CCK-dependent ERK activity. These results indicate an involvement of PI3K class 1A species α, β or/and δ in signal transduction via CCKB receptors. In addition, protein kinase C (PKC)-dependent signaling pathways contribute to CCKB-mediated MAP kinase signaling as shown by inhibition of CCK-8-induced ERK activation by the PKC inhibitor bisindolylmaleimide.
Photo-CIDNP 13C Magic Angle Spinning NMR on Bacterial Reaction Centres: Exploring the Electronic Structure of the Special Pair and Its Surroundings
Authors: Matysik Jörg , Schulten Els , Alia Alia , Gast Peter , Raap Jan , Lugtenburg Johan , Hoff Arnold J. , Groot Huub J. M. de 
Published: October 2004

Abstract
Photochemically induced dynamic nuclear polarisation
(photoCIDNP) in intact bacterial reaction centres has been observed by 13Csolid
state NMR under continuous illumination with white light. Strong intensity
enhancement of 13C NMR signals of the aromatic rings allows probing the
electronic ground state of the two BChl cofactors of the special pair at the
molecular scale with atomic selectivity. Differences between the two BChl
cofactors are discussed. Several aliphatic 13C atoms of cofactors, as well as
13C atoms of the imidazole ring of histidine residue(s), show nuclearspin
polarisation to the same extent as the aromatic nuclei of the cofactors.
Mechanisms and applications of polarisation transfer are discussed.
Determination of Free Apolipoprotein(a) in Serum by Immunoassay and Its Significance for Risk Assessment in Patients with Coronary Artery Disease
Authors: Herrmann Wolfgang , Quast Sabine , Wolter Kai , Eger Hartmut , Kießig Stefan T. , Hahmann Harry , Kreuter Jörg , Molinari Ewald 
Published: October 2004

Abstract
This paper describes a new enzyme-linked ligand sorbent assay (ELLSA) to quantify free apolipoprotein(a) (apo(a)). The new test immobilizes free apo(a) utilizing a specific peptide that carries the amino acid sequence of a non-covalent apo(a) binding site on apoB3375–3405 (ligand-peptide). The ligand-peptide coupled to Sepharose was used in affinity chromatography to separate free apo(a) from whole serum. Isolated free apo(a) consisted of full length apo(a) and smaller apo(a). Additionally, free apo(a) levels determined by ELLSA as well as by electroimmunodiffusion correlated moderately well. Significantly increased serum concentrations of free apo(a) were found in coronary artery disease. The mean value of free apo(a) was three times higher in patients than in controls while the lipoprotein(a) (Lpla)) concentration was doubled. Utilizing receiver operating characteristic diagrams, it was shown that the free apo(a)-ELLSA had a better diagnostic test performance in atherosclerotic risk assessment than the Lp(a)-test: specificity free apo(a)-ELLSA 0.77, Lp(a)-test 0.81 [with (a:a)-enzyme immunoassay (EIA)] to 0.83 [with (a:B)-EIA]; sensitivity free apo(a)-ELLSA 0.57, Lp(a)-test 0.36 to 0.40. In conclusion, the new free apo(a)-ELLSA allows for the specific quantification of free apo(a). This provides an interesting indicator for atherosclerotic risk assessment.
Current System of Undergraduate and Postgraduate Education in Clinical Chemistry in Croatia
Authors: Juretić Dubravka , Žanić-Grubišić Tihana 
Published: October 2004

Abstract
We present here a specific model of education and practice in clinical chemistry that is almost exclusively based on the medical biochemists academically educated at the Faculty of Pharmacy and Biochemistry. This model has been successfully used for 35 years in Croatian Health Care System. Undergraduate education in clinical chemistry consists of four years of specific university education which provides for all requirements to maintain the high quality of our profession. Postgraduate education leading to more specific scientific and professional expertise is further regulated by the laws issued by The Ministry of Health and The Ministry of Science and Technology. At present there is a compulsory programme of lifelong continuing education recognised by Croatian Chamber of Medical Biochemists.
A Rapid and Sensitive Automated Light Scattering Immunoassay for Serum C-Reactive Protein and the Definition of a Reference Range in Healthy Blood Donors
Authors: Price Christopher P. , Calvin Jacqui , Walker Susan A. , Trull Andrew , Newman David J. , Gorman Eileen G. 
Published: October 2004

Abstract
The increasing interest in the measurement of serum C-reactive protein in relation to the risk stratification of patients with chest pain has demonstrated the need for more sensitive routine methods of measurement, and an accurate definition of the reference range. We report the determination of a reference range in serum samples from 491 blood donors using a particle enhanced turbidimetric immunoassay that has been modified to offer better imprecision within the reference range. The median values were found to be 2.40 and 2.20 mg/l for males and females, respectively, with 95th percentile range of 1.20–5.20 and 0.40–5.40 mg/l respectively.
Photodynamic Effects In Vitro in Fresh GynecologicTumors Analyzed with a Bioluminescence Method
Authors: Schlosser Viola , Koechli Ossi R. , Cattaneo Rosanna , Jentsch Brigitte , Haller Urs , Walt Heinrich 
Published: October 2004

Abstract
Photodynamic therapy (PDT) is a promising alternative method for clinical cancer treatment. In the present study, cells from four breast carcinomas, seven ovarian carcinomas of various stages of differentiation, and ascites from a diffuse metastatic tumor were treated by PDT in vitro. Tetra(m-hydroxyphenyl)-chlorin (m-THPC) was used as the photosensitizer. Surviving cell rate was evaluated by the ATP-Cell-Viability-Assay (ATP-CVA), which measures light production as an interaction of intracellular ATP with the luciferin-luciferase complex. The most effective PDT of the tumor cells was achieved at an m-THPC concentration of 0.2 μg/ml following incubation of the cells with photosensitizer for 24 hours. PDT toxicity resulted in a cell survival rate of 1 % to 42 % compared to untreated control cells (survival rate of control = 100 %). The inhibitor concentration IC50 of m-THPC was determined both in the dark (dark toxicity) and in combination with laser irradiation. IC50 was defined as the concentration of photosensitizer which caused 50 % of cell death. The IC50 values were heterogeneous in all tumor specimens examined. IC50 values for dark toxicity were on average 0.14 μg m-THPC/ml for primary ovarian carcinoma, 2.16 μg m-THPC ml for refractory ovarian carcinoma and 0.3 μg m-THPC/ml for breast carcinoma. After PDT, average IC50 value for refractory ovarian carcinoma was 0.04 μg m-THPC/ml, for primary ovarian carcinoma 0.05 μg m-THPC/ml and for breast carcinoma 0.03 μg m-THPC/ml. These data might indicate that clinical PDT of gynecological carcinoma requires individual treatment conditions to achieve optimal results.