bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPUTING LINEAR DATA DEPENDENCIES IN NESTED LOOP PROGRAMS
Authors: HECKLER CHRISTIAN , THIELE LOTHAR
Published: November 2004

An important topic in automatically parallelizing nested loop programs (for the implementation on a parallel machine or for the mapping onto VLSI circuits) is the computation of linear data dependencies. Recently, Feautrier has developed an algorithm which is based on the solution of a parametric integer linear program. In this paper another method is presented. This method only works for special cases but it should be simpler and more efficient. Apart of these special cases the extensions suggested in this paper provide a system of fewer inequalities and variables in the general case compared to the original algorithm of Feautrier. The key idea is the solution of a system of linear diophantine equations.
A MATHEMATICAL THEORY AND ITS ENVIRONMENT FOR PARALLEL PROGRAMMING
Authors: VIOLARD ERIC
Published: November 2004

This paper presents the main concepts of the mathematical theory PEI for parallel programming and emphasizes its derivation power. The mathematical basis of this theory leads to a nice implementation in CENTAUR7 of an environment whose purpose is to transform parallel programs. It is illustrated by two similar examples: the convolution sum and the Dirichlet product. The second one uses non-affine dependencies that can be easily taken into account using PEI.
1-EDGE FAULT-TOLERANT DESIGNS FOR MESHES
Authors: CHOU RAY-SHYNG , HSU LIH-HSING
Published: November 2004

A graph G* is k-edge fault-tolerant with respect to a graph G, denoted by k- EFT (G), if every graph obtained by removing any k edges from G* contains G. A k- EFT (G) graph is optimal if it contains the minimum number of edges among all k- EFT (G) graphs. Recently, Harary and Hayes have presented a design which is 1-EFT with respect to meshes and conjectured that their design is optimal. We prove their conjecture is false by giving another design which is 1-EFT with respect to meshes.
EFFICIENT PARALLEL SHUFFLE RECOGNITION
Authors: NIVAT M. , RAMKUMAR G.D.S. , PANDU RANGAN C. , SAOUDI A. , SUNDARAM R.
Published: November 2004

This paper presents a parallel algorithm for verifying that a string X is formed by the shuffle of two strings Y and Z. The algorithm runs in O(log2n) time with O(n2/log2 n) processors on the EREW-PRAM model.
THE AFFINE TODA S-MATRICES vs PERTURBATION THEORY
Authors: SASAKI RYU , ZEN FREDDY PERMANA
Published: November 2004

We present perturbative calculations for the Affine Toda Field Theory (ATFT) S-matrices to the second order in the coupling constants for [Formula: see text] and [Formula: see text] in general, to the fourth order for [Formula: see text] theory as well as to the sixth order for [Formula: see text] theory. Conventional Feynman–Dyson calculation method and the dispersion approach are used to calculate the complete form of the perturbation amplitudes in contrast to the pole residues in previous papers. The results agree with those S-matrices obtained in the S-matrix approach, namely those based on analyticity, unitarity, crossing and bootstrap equation.
ABELIAN BOSONIZATION IN A PATH INTEGRAL FRAMEWORK
Authors: JOLICŒUR TH. , LE GUILLOU J. C.
Published: November 2004

We investigate the Abelian bosonization procedure in the light of a path integral formulation. The correlation functions of the Bose and Fermi fields are directly related by use of several changes of variables including chiral rotations à la Fujikawa. Operator identities are replaced by statements on partition functions with suitably defined sources. The Thirring and sine–Gordon models as well as the Schwinger model are treated. We also discuss a generalized Thirring model.
NAMBU–GOTO STRING THEORY ON A SPACE–TIME LATTICE — PLAQUETTE RANDOM SURFACES REVISITED
Authors: DEARNALEY ROGER
Published: November 2004

Two lattice approximations to the Nambu–Goto string using random surfaces constructed from lattice plaquettes are described. The first is well known, and was shown by Eguchi and Kawai to have a sum over histories which is divergent for all values of the bare (i.e. unrenormalized) string tension.1 This result is confirmed, but it is shown that this is not true of the second lattice approximation. Its sum over histories is convergent for all values of the bare string tension above a certain limit, and is proved to be divergent for all values below this limit. If this limit could be shown to give a satisfactory continuum limit, and the model could be proven to be free of anomalies in the critical dimension, it would give us a finite-dimensional local second-quantized path-integral definition of Nambu–Goto string theory.
INTEGRABLE STRUCTURES IN MATRIX MODELS AND PHYSICS OF 2D GRAVITY
Authors: MARSHAKOV A.
Published: November 2004

A review of the appearance of integrable structures in the matrix model description of 2D gravity is presented. Most of the ideas are demonstrated with technically simple but ideologically important examples. Matrix models are considered as a sort of “effective” description of continuum 2D field theory formulation. The main physical role in such a description is played by the Virasoro-W conditions, which can be interpreted as certain unitarity or factorization constraints. Both discrete and continuum (generalized Kontsevich) models are formulated as the solutions to those discrete (continuous) Virasoro-W constraints. Their integrability properties are proved, using mostly the determinant technique highly related to the representation in terms of free fields. The paper also contains some new observations connected with formulation of more-general-than-GKM solutions and deeper understanding of their relation to 2D gravity.
SOFT MODE CONTRIBUTION TO PATH INTEGRALS
Authors: BELYAEV V.M.
Published: November 2004

A method for nonperturbative path integral calculation is proposed. Quantum mechanics as the simplest example of a quantum field theory is considered. All modes are decomposed into hard (with frequencies [Formula: see text]) and soft (with frequencies [Formula: see text]) ones, where ω0 is some parameter. Hard mode contribution is considered through weak coupling expansion. A low energy effective Lagrangian for soft modes is used. In the case of soft modes we apply a strong coupling expansion. To realize this expansion a special basis in functional space of trajectories is considered. A good convergency for the pro posed procedure in the case of potential V(x)=λx4 is demonstrated. The ground state energy of the unharmonic oscillator is calculated.
DETERMINING LOCATION AND ORIENTATION OF A LABELLED CYLINDER USING POINT-PAIR ESTIMATION ALGORITHM
Authors: LEE JIANN-DER , LEE JAU-YIEN , YOU YUAN-CHIUAN , CHEN CHIN-HSING
Published: November 2004

In this paper, a new feasible approach is proposed to determine the 3-D location and orientation as well as the radius of a cylinder pasted with a known-height label. The proposed approach uses a rectangle-shaped standard mark composed of two point-pairs for performing monocular image analysis.

A monocular image of a labelled cylinder is first taken. Image processing and numerical analysis techniques are then used to set two point-pairs located on the boundary of the visible part of the cylindrical label. According to 3-D imaging geometry, the location and orientation as well as the radius of the cylinder relative to the camera are uniquely determined by using 3-D vector analysis and simple algebraic computation. Owing to the full linearity of the,derivation, this approach can achieve high speed requirement. In addition, no prerequisite restriction is imposed on the image-grabbing process and there is no need to perform the calibration of the focal length since it can be derived. Experimental results, with mean errors less than 3%, prove the feasibility of the proposed approach.
A NEW EDGE DETECTION METHOD THROUGH TEMPLATE MATCHING
Authors: WANG MAO-JIUN J. , CHANG SHIAU-CHYI , LIU CHIH-MING , WU WEN-YEN
Published: November 2004

This paper reviews some gradient edge detection methods and proposes a new detector — the template matching edge detector (TMED). This detector utilizes the concepts of pattern analysis and the template matching of 3×3 masks. A set of performance criteria was used to evaluate the gradient edge detectors as well as the template matching edge detector. The results indicate that the new method is superior to the other gradient edge detectors. In addition, the template matching edge detector has also demonstrated good performance on noisy images. It can obtain very precise edge detection of single pixel width.
DOCUMENT STRUCTURES: A SURVEY
Authors: TANG YUAN Y. , SUEN CHING Y.
Published: November 2004

Knowing the structure of a document is the key to successful processing of a document. There exist a variety of definitions of document structures. This paper is a survey of methods describing document structures. Several novel concepts and theoretical analyses are also presented.

A document not only has a concrete two-dimensional image but also a conceptual structure which corresponds to human’s thinking. The process of publishing or writing corresponds to encoding the conceptual structure into a concrete structure. Conversely, the concrete structure of the document is decoded into its conceptual one in document processing. In this paper, conceptual and concrete structures are introduced.

A complete system for treating both of the conceptual and concrete structures is probably still decades away. As the first stage, this study puts some emphasis on concrete structures, for which, geometric, logical, textual, information, textural, and other structures are described.
AN ADAPTIVE MODULAR NEURAL NETWORK WITH APPLICATION TO UNCONSTRAINED CHARACTER RECOGNITION
Authors: MUI LIK , AGARWAL ARUN , GUPTA AMAR , WANG PATRICK SHEN-PEI
Published: November 2004

The topology and the capacity of a traditional multilayer neural system, as measured by the number of connections in the network, has surprisingly little impact on its generalization ability. This paper presents a new adaptive modular network that offers superior generalization capability. The new network provides significant fault tolerance, quick adaption to novel inputs, and high recognition accuracy. We demonstrate this paradigm on recognition of unconstrained handwritten characters.
PROCONSUL ON THE WAY TO AUTOMATED PROTOCOL ENGINEERING
Authors: TARNAY KATIE , VARGA LÁSZLÓ ZS. , CSOPAKI GYULA
Published: November 2004

The analysis, development and testing of communication protocols are complex problems. These tasks can be made easier with protocol development tools, which support the whole protocol development process from specification to testing. They are either stand-alone tools related to a specific protocol engineering function (e.g. validation) or integrated protocol workstations solving several functions. The protocol development tools are usually based on formal description techniques.

This paper describes the notion of CAPE (Computer-Aided Protocol Engineering) derived from CASE (Computer-Aided Software Engineering) and presents the PROCONSUL protocol workstation. The intelligent editors of PROCONSUL are described in detail.
DIGIT-SERIAL SQUARING ARCHITECTURE
Authors: BASHAGHA A.E. , IBRAHIM M.K.
Published: November 2004

A digit-serial squaring architecture based on radix-2n arithmetic is presented to carry out squaring digit serially. In this paper, the conventional binary squaring algorithm is modified and a radix-2n squaring algorithm which is used to design the proposed architectures is presented. The resulting basic cell is the Digital Controlled Add/shiFt (DCAF) cell. The advantage of using radix-2n arithmetic is that it specifies the functionality of the DCAF cell only and, hence, there is no restriction on the type of adder to be used. It can be a ripple carry adder, a carry lookahead adder, a pipelined adder, or a carry-save adder. The merit of the new structure is that it provides system designers with a great deal of flexibility to find the best trade-off between cost and throughput by varying the radix, the type of adder to be used and/or the number of pipelined stages.
EFFICIENT ENUMERATION OF GRID POINTS IN A CONVEX POLYGON AND ITS APPLICATION TO INTEGER PROGRAMMING
Authors: KANAMARU NAOYOSHI , NISHIZEKI TAKAO , ASANO TETSUO
Published: November 2004

This paper first presents an algorithm for enumerating all the integer-grid points in a given convex m-gon in O(K + m + log n) time where K is the number of such grid points and n is the dimension of the m-gon, i.e., the shorter length of the horizontal and vertical sides of an axis-parallel rectangle enclosing the m-gon. The paper next gives a simple algorithm which solves a two-variable integer programming problem with m constraints in O(m log m + log n) time where n is the dimension of a convex polygon corresponding to the feasible solution space. This improves the best known algorithm in complexity and simplicity. The paper finally presents algorithms for counting the number of grid points in a triangle or a simple polygon.
CURVED SELF-DIFFRACTION PATTERNS FROM DYNAMIC GRATINGS
Authors: EICHLER H.J. , GLOTZ M. , KUMMROW A.
Published: November 2004

The self-diffraction by dynamic gratings leads to curved patterns, even for flat samples, if the sample is tilted with respect to the exciting beams. The effect is in good approximation the same as for static gratings. Calculations are compared with ps-pulse wave mixing experiments in silicon.
SHARE: A METHODOLOGY AND ENVIRONMENT FOR COLLABORATIVE PRODUCT DEVELOPMENT
Authors: TOYE GEORGE , CUTKOSKY MARK R. , LEIFER LARRY J. , TENENBAUM J. MARTY , GLICKSMAN JAY
Published: November 2004

The SHARE project seeks to apply information technologies in helping design teams gather, organize, re-access, and communicate both informal and formal design information to establish a "shared understanding" of the design and design process. This paper presents the visions of SHARE, along with the research and strategies undertaken to build an infrastructure toward its realization. A preliminary prototype environment is being used by designers working on a variety of industry sponsored design projects. This testbed continues to inform and guide the development of NoteMail, MovieMail, and Xshare, as well as other components of the next generation SHARE environment that will help distributed design teams work together more effectively on the Internet.
MINIMAL 3-BRAID REPRESENTATIONS
Authors: KEEVER R. D.
Published: November 2004

This paper provides necessary and sufficient conditions for a representation of any 3-braid to be minimal (with regard to the number of crossings) and includes an algorithm to obtain such a representation, the number of distinct minimal representations of a given 3-braid, as well as a unique canonical form for each braid in B3.

Also presented are necessary and sufficient conditions for any 3-string braid word to be a minimal representation of its conjugacy class. A canonical form for each conjugacy class in B3 is given.
ITERATIVE INDUCTION OF A CATEGORY MEMBERSHIP FUNCTION
Authors: NARAZAKI HIROSHI , RALESCU ANCA L.
Published: November 2004

We propose a new iterative method for inducing classification knowledge from symbolic data. Our method generates a hierarchy of clusters and does not assume a particular knowledge representation formula (e.g., a conjunctive formula, a linear discriminant function). Our method consists of two stages, i.e., the optimization and clustering stages. The first stage maps the symbolic problem into the numerical domain based on an optimization approach. In the second stage, the examples are clustered into positive, negative, and fuzzy zones using induced membership degrees. This learning procedure is iterated until the fuzzy zone becomes empty. Out method learns "topological knowledge" which is found to be useful for the evaluation of the training data quality. Further, we show that our method is useful using real world data of an industrial knowledge acquisition problem.
TECHNOLOGY-BASED FIRMS: CRITICAL ASPECTS OF THEIR EARLY DEVELOPMENT
Authors: KLOFSTEN MAGNUS
Published: November 2004

The founding and early development of a firm are crucial events. Despite this fact, most research is aimed at problems existing in firms that are established and have passed the early development. Consequently, knowledge of the early development process in a business firm is limited, particularly where technology-based firms are concerned.

The purpose of this paper is to describe and analyse the early development processes of technology-based firms. The research questions are: What aspects are important in the early development of a technology-based firm? Are some of these aspects more difficult to develop than others and, if so, why? A case study approach is used. Three technology-based firms have over a period of five years been studied in detail, using interviews and sources such as minutes of board meetings, business and market plans and other documents.

From a review of the literature, eight essential aspects (business idea, product, market, organization, expertise, prime mover, customer relations and other corporate relations) of the early development have been chosen. The results show that the degree of difficulty to develop the aspects vary. A particularly difficult aspect is to define the market.
THE DYNAMICS OF GROWTH AND SUCCESSION IN ENTREPRENEURIAL ORGANISATIONS
Authors: CUNNINGHAM JOHN BARTON , HO JANICE
Published: November 2004

There are two sets of transitions which most family businesses face. (i) There are often conflicts between fathers, mothers, sons, daughters, and non-family members over who will take over the business. (ii) The family business is also responding to problems relating to growth and adaptation, and the need for management systems that goes beyond the persistence and personality of the founder. This paper provides a framework for understanding how these two processes are interlinked. Family and company transitions both require changes in the organisation’s direction and focus. This paper suggests that family and company transitions provoke different reactions making it necessary to respond in different ways.
VENTURE CAPITALISTS’ COLLECTIVE BELIEFS ON NEW BUSINESS VENTURE INVESTMENTS
Authors: RIQUELME HERNAN
Published: November 2004

A multi-method approach (investment case analysis, administrative records, published interviews, questionnaire, and personal interviews) was conducted in order to deal with the widest possible range of aspects connected with venture capitalists’ investments in new businesses. Our study identified 73 decision rules or heuristics associated with such investments and we examined the extent to which these rules were shared by the UK venture capital community. We proposed to find out the reasons for business problems/failures and whether venture capitalists’ attribution of blame is biased. We explained what social functions this attribution serves and what consequences it entails for the venture capitalist, the entrepreneur, and the providers of funds to venture capital firms. Our decision rules demonstrate that not only evaluation criteria are important to understanding success of new ventures but also other heuristics associated with the deal structure, and two basic social processes, namely, hands-on management and networks. This very much reflects the widespread belief among venture capitalists that “it is not just a matter of picking up the winners”.

This research has made explicit the venture capitalists’ “theory”of new business failures and illustrates their attribution bias towards the managerial team. This attribution of blame has serious consequences for the managerial team and the venture capitalists themselves as they will try to alter the managerial team rather than any other situational factor, e.g. market, product.
SOFTWARE RELIABILITY GROWTH AND INNOVATION DIFFUSION MODELS: AN INTERFACE
Authors: KAPUR P. K. , SINGH OMPAL , MITTAL RUBINA
Published: November 2004

The objective of this paper is to show an interface between modelling, allocation problems and control problems in software reliability and marketing. It has been brought out that in models which exist in software reliability and defined implicitly/explicitly for errors of two types; it is the dependency factor among errors that gives rise to S-Shaped growth curve. It is further shown that this dependency on the line of categorization of errors, adopters can be of several types/categories. Such categorization, though implicit in nature, not brought out in literature, further strengthens the fact that modeling any software phenomenon should incorporate errors of different severity rather explicitly. We have also provided a general model which can account for imperfect debugging and error generation in software reliability. The approach followed is rather implicit in nature but provides good closed form solutions. Such solutions were being alternatively looked for in innovation diffusion models namely the Bass Model, which can account for repeat purchase and growing market size. Besides we also show how problem of resource allocation and control in the two fields can be analyzed similarly. The analogy as brought out in this paper is interesting and may further lead to enriching the two areas of current research.
AGING INFLUENCED BY REPAIR, REPAIR EFFICIENCY AND REALIZABILITY OF A RENEWAL RELATED DISTRIBUTION
Authors: BHATTACHARJEE M.C.
Published: November 2004

For repairable systems, aging properties of the time to first failure cannot adequately reflect its degradation over time — which is influenced by repairs. For such systems, exploring notions of aging under repairs would provide a more relevant description of deterioration in performance. A framework to formulate appropriate notions of aging relative to repair strategies and examine their implications is indicated. Included among such strategies are renewals (perfect repair or, replacements) and minimal repairs, as are the repair schemes of Brown-Proschan and Block-Borges-Savits. We examine some specific notions of repair relative to aging and briefly review recent results on two aging properties under perfect repairs. The concept of efficiency of repair strategies is introduced and illustrated by simple examples. Our final results concern an induced distribution related to perfect repairs and its realizability.
PATH RELIABILITIES IN TORUS-RING NETWORKS
Authors: YANG OLIVER W.W.
Published: November 2004

This paper evaluates the path reliabilities of torus-ring networks in terms of the link reliability, node reliability and network size. A computational algorithm based on a level-by-level reduction method has been formulated to facilitate the evaluations. This algorithm has advantages in (i) analyzing networks of arbitrary ring orientation, geometry and network size, and (ii) being efficient for large networks because its complexity grows slowly with respect to the network size. Various evaluations and comparisons using this algorithm have been carried out. In comparing with the prevailing ring and bus topologies, the torus-ring offers a much better path reliability performance.
Expression levels of RyR1 and RyR3 control resting free Ca2+ in skeletal muscle
Authors: Perez Claudio F. , López José R. , Allen Paul D.
Published: November 2004

To better understand the role of the transient expression of ryanodine receptor (RyR) type 3 (RyR3) on Ca2+ homeostasis during the development of skeletal muscle, we have analyzed the effect of expression levels of RyR3 and RyR1 on the overall physiology of cultured myotubes and muscle fibers. Dyspedic myotubes were infected with RyR1 or RyR3 containing virions at 0.2, 0.4, 1.0, and 4.0 moieties of infection (MOI), and analysis of their pattern of expression, caffeine sensitivity, and resting free Ca2+ concentration ([Ca2+]r) was performed. Although increased MOI resulted in increased expression of each receptor isoform, it did not significantly affect the immunopattern of RyRs or the expression levels of calsequestrin, triadin, or FKBP-12. Interestingly, myotubes expressing RyR3 always had significantly higher [Ca2+]r and lower caffeine EC50 than did cells expressing RyR1. Although some of the increased sensitivity of RyR3 to caffeine could be attributed to the higher [Ca2+]r in RyR3-expressing cells, studies of [3H]ryanodine binding demonstrated intrinsic differences in caffeine sensitivity between RyR1 and RyR3. Tibialis anterior (TA) muscle fibers at different stages of postnatal development exhibited a transient increase in [Ca2+]r coordinately with their level of RyR3 expression. Similarly, adult soleus fibers, which also express RyR3, had higher [Ca2+]r than did adult TA fibers, which exclusively express RyR1. These data show that in skeletal muscle, RyR3 increases [Ca2+]r more than RyR1 does at any expression level. These data suggest that the coexpression of RyR1 and RyR3 at different levels may constitute a novel mechanism by which to regulate [Ca2+]r in skeletal muscle.
mitoKATP channel activation in the postanoxic developing heart protects E-C coupling via NO-, ROS-, and PKC-dependent pathways
Authors: Sarre Alexandre , Lange Norbert , Kucera Pavel , Raddatz Eric
Published: November 2004

Whereas previous studies have shown that opening of the mitochondrial ATP-sensitive K+ (mitoKATP) channel protects the adult heart against ischemia-reperfusion injury, it remains to be established whether this mechanism also operates in the developing heart. Isolated spontaneously beating hearts from 4-day-old chick embryos were subjected to 30 min of anoxia followed by 60 min of reoxygenation. The chrono-, dromo-, and inotropic disturbances, as well as alterations of the electromechanical delay (EMD), reflecting excitation-contraction (E-C) coupling, were investigated. Production of reactive oxygen species (ROS) in the ventricle was determined using the intracellular fluorescent probe 2′,7′-dichlorofluorescin (DCFH). Effects of the specific mitoKATP channel opener diazoxide (Diazo, 50 μM) or the blocker 5-hydroxydecanoate (5-HD, 500 μM), the nitric oxide synthase (NOS) inhibitor NG-nitro-l-arginine methyl ester (l-NAME, 50 μM), the antioxidant N-(2-mercaptopropionyl)glycine (MPG, 1 mM), and the PKC inhibitor chelerythrine (Chel, 5 μM) on oxidative stress and postanoxic functional recovery were determined. Under normoxia, the baseline parameters were not altered by any of these pharmacological agents, alone or in combination. During the first 20 min of postanoxic reoxygenation, Diazo doubled the peak of ROS production and, interestingly, accelerated recovery of ventricular EMD and the PR interval. Diazo-induced ROS production was suppressed by 5-HD, MPG, or l-NAME, but not by Chel. Protection of ventricular EMD by Diazo was abolished by 5-HD, MPG, l-NAME, or Chel, whereas protection of the PR interval was abolished by l-NAME exclusively. Thus pharmacological opening of the mitoKATP channel selectively improves postanoxic recovery of cell-to-cell communication and ventricular E-C coupling. Although the NO-, ROS-, and PKC-dependent pathways also seem to be involved in this cardioprotection, their interrelation in the developing heart can differ markedly from that in the adult myocardium.
Metabotropic Glutamate Receptor Antagonist AIDA Blocks Induction of Mossy Fiber-CA3 LTP In Vivo
Authors: Thompson Kenira J. , Mata Mario L. , Orfila James E. , Barea-Rodriguez Edwin J. , Martinez Joe L.
Published: November 2004

Metabotropic glutamate receptors (mGluR) are implicated in long-term memory storage. mGluR-I and mGluR-II antagonists impede various forms of learning and long-term potentiation (LTP) in animals. Despite the evidence linking mGluR to learning mechanisms, their role in mossy fiber-CA3 long-term potentiation (LTP) is not yet clear. To explain the involvement of mGluR-I in memory mechanisms, we examined the function of the mGluR-I antagonist 1-aminoindan-1, 5-dicarboxylic acid (AIDA) on the induction of mossy fiber-CA3 LTP in vivo in male Sprague Dawley and Fischer 344 (F344) rats. Acute extracellular mossy fiber (MF) responses were evoked by stimulation of the MF bundle and recorded in the stratum lucidum of CA3. The excitatory postsynaptic potential (EPSP) magnitude was measured by using the initial slope of the field EPSP slope measured 2–3 ms after response onset. After collection of baseline MF-CA3 responses at 0.05 Hz, animals received either ((±))-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid ( N-methyl-d-aspartate-R antagonist, 10 mg/kg ip), naloxone (opioid-R antagonist, 10 mg/kg ip), or AIDA (mGluR antagonist, 1 mg/kg ip or 37.5 nmol ic). LTP was induced by two 100-Hz trains at the intensity sufficient to evoke 50% of the maximal response. Responses were collected for an additional 1 h. AIDA blocked induction of LTP in the mossy fiber pathway ( P < 0.05) in both strains of rats after systemic and in Sprague Dawley rats after intrahippocampal injection.
Effects of Temperature on Calcium Transients and Ca2+-Dependent Afterhyperpolarizations in Neocortical Pyramidal Neurons
Authors: Lee J. C. F. , Callaway J. C. , Foehring R. C.
Published: November 2004

In neocortical pyramidal neurons, the medium (mAHP) and slow AHP (sAHP) have different relationships with intracellular [Ca2+]. To further explore these differences, we varied bath temperature and compared passive and active membrane properties and Ca2+transients in response to a single action potential (AP) or trains of APs. We tested whether Ca2+-dependent events are more temperature sensitive than voltage-dependent ones, the slow rise time of the sAHP is limited by diffusion, and temperature sensitivity differs between the mAHP and sAHP. The onset and decay kinetics of the sAHP were very temperature sensitive (more so than diffusion). We found that the decay time course of Ca2+transients was also very temperature sensitive. In contrast, the mAHP (amplitude, time to peak, and exponential decay) and sAHP peak amplitude were moderately sensitive to temperature. The amplitudes of intracellular Ca2+transients evoked either by a single spike or a train of spikes showed modest temperature sensitivities. Pyramidal neuron input resistance was increased by cooling. With the exception of threshold, which remained unchanged between 22 and 35°C, action potential parameters (amplitude, half-width, maximum rates of rise and fall) were modestly affected by temperature. Collectively, these data suggest that temperature sensitivity was higher for the Ca2+-dependent sAHP than for voltage-dependent AP parameters or for the mAHP, diffusion of Ca2+over distance cannot explain the slow rise of the sAHP in these cells, and the kinetics of the sAHP and mAHP are affected differently by temperature.
Polytrodes: High-Density Silicon Electrode Arrays for Large-Scale Multiunit Recording
Authors: Blanche Timothy J. , Spacek Martin A. , Hetke Jamille F. , Swindale Nicholas V.
Published: November 2004

We developed a variety of 54-channel high-density silicon electrode arrays (polytrodes) designed to record from large numbers of neurons spanning millimeters of brain. In cat visual cortex, it was possible to make simultaneous recordings from >100 well-isolated neurons. Using standard clustering methods, polytrodes provide a quality of single-unit isolation that surpasses that attainable with tetrodes. Guidelines for successful in vivo recording and precise electrode positioning are described. We also describe a high-bandwidth continuous data-acquisition system designed specifically for polytrodes and an automated impedance meter for testing polytrode site integrity. Despite having smaller interconnect pitches than earlier silicon-based electrodes of this type, these polytrodes have negligible channel crosstalk, comparable reliability, and low site impedances and are capable of making high-fidelity multiunit recordings with minimal tissue damage. The relatively benign nature of planar electrode arrays is evident both histologically and in experiments where the polytrode was repeatedly advanced and retracted hundreds of microns over periods of many hours. It was possible to maintain stable recordings from active neurons adjacent to the polytrode without change in their absolute positions, neurophysiological or receptive field properties.
Properties of Dopamine Release and Uptake in the Songbird Basal Ganglia
Authors: Gale Samuel D. , Perkel David J.
Published: November 2004

Vocal learning in songbirds requires a basal ganglia circuit termed the anterior forebrain pathway (AFP). The AFP is not required for song production, and its role in song learning is not well understood. Like the mammalian striatum, the striatal component of the AFP, Area X, receives dense dopaminergic innervation from the midbrain. Since dopamine (DA) clearly plays a crucial role in basal ganglia–mediated motor control and learning in mammals, it seems likely that DA signaling contributes importantly to the functions of Area X as well. In this study, we used voltammetric methods to detect subsecond changes in extracellular DA concentration to gain better understanding of the properties and regulation of DA release and uptake in Area X. We electrically stimulated Ca2+- and action potential–dependent release of an electroactive substance in Area X brain slices and identified the substance as DA by the voltammetric waveform, electrode selectivity, and neurochemical and pharmacological evidence. As in the mammalian striatum, DA release in Area X is depressed by autoinhibition, and the lifetime of extracellular DA is strongly constrained by monoamine transporters. These results add to the known physiological similarities of the mammalian and songbird striatum and support further use of voltammetry in songbirds to investigate the role of basal ganglia DA in motor learning.
Structure of optimal trajectories in a nonlinear dynamic model with endogenous delay
Authors: Hritonenko Natali , Yatsenko Yuri
Published: November 2004

An exact solution is constructed to a nonlinear optimization
problem in an integral dynamic model with delay. The problem
involves the unknown duration of the delay and has important
applications to the optimal replacement of capital equipment
under technological change.
The Problem of Agency in Scientific Distributed Cognitive Systems
Authors: Giere Ronald
Published: November 2004

From the perspective of cognitive science, it is illuminating to think of much contemporary scientific research as taking place in distributed cognitive systems. This is particularly true of large-scale experimental and observational systems such as the Hubble Telescope. Clark, Hutchins, Knorr-Cetina, and Latour insist or imply such a move requires expanding our notions of knowledge, mind, and even consciousness. Whether this is correct seems to me not a straightforward factual question. Rather, the issue seems to be how best to develop a theoretical understanding of such systems appropriate to the study of science and technology. I argue that there is no need to attribute to such systems as a whole any form of cognitive agency. We can well understand the importance of such systems while restricting agency to the human components. The implication is that we think of these large-scale distributed cognitive systems not so much as unified wholes, but as hybrid systems including both physical artifacts and ordinary humans.
Introduction: Why There Should Be a Cognitive Anthropology of Science
Authors: Heintz Christophe
Published: November 2004

I argue that questions, methods and theories drawn from cognitive anthropology are particularly appropriate for the study of science. I also emphasize the role of cognitive anthropology of science for the integration of cognitive and social studies of science. Finally, I briefly introduce the papers and attempt to draw the main directions of research.
THE OURANOLOGY OF THE APOCALYPSE OF ABRAHAM
Authors: Poirier John
Published: November 2004

Scholars universally dismiss the reference to an eighth heaven in Apoc. Abr. 19.6 as a late addition, but they have apparently done so without fully understanding the difficult sequence of activity in chaps. 15-19. With the help of other texts, the confusing web of spatial indicators in these chapters can be mapped out in a sensible and logical manner. This article not only argues that the narrative is more coherent than previous accounts have assumed, but also that the eighth heaven is a necessary part of the narrative.
Efficient activation of gene expression using a heat-shock inducible Gal4/Vp16-UAS system in medaka
Authors: Grabher Clemens , Wittbrodt Joachim
Published: November 2004

Background

Genetic interference by DNA, mRNA or morpholino injection is a widely used approach to study gene function in developmental biology. However, the lack of temporal control over the activity of interfering molecules often hampers investigation of gene function required during later stages of embryogenesis. To elucidate the roles of genes during embryogenesis a precise temporal control of transgene expression levels in the developing organism is on demand.

Results

We have generated a transgenic Gal4/Vp16 activator line that is heat-shock inducible, thereby providing a tool to drive the expression of specific effector genes via Gal4/Vp16. Merging the Gal4/Vp16-UAS system with the I-SceI meganuclease and the Sleeping Beauty transposon system allows inducible gene expression in an entirely uniform manner without the need to generate transgenic effector lines. Combination of this system with fluorescent protein reporters furthermore facilitates the direct visualization of transgene expressing cells in live embryos.

Conclusion

The combinatorial properties of this expression system provide a powerful tool for the analysis of gene function during embryonic and larval development in fish by ectopic expression of gene products.
Inconsistent self-reported mammography history: Findings from the National Population Health Survey longitudinal cohort
Authors: Bancej Christina M , Maxwell Colleen J , Snider Judy
Published: November 2004

Background

Self-reported information has commonly been used to monitor mammography utilization across populations and time periods. However, longitudinal investigations regarding the prevalence and determinants of inconsistent responses over time and the impact of such responses on population screening estimates are lacking.

Methods

Based on longitudinal panel data for a representative cohort of Canadian women aged 40+ years (n = 3,537) assessed in the 1994–95 (baseline) and 1996–97 (follow-up) National Population Health Survey (NPHS), we examined the prevalence of inconsistent self-reports of mammography utilization. Logistic regression models were used to estimate the associations between women's baseline sociodemographic and health characteristics and 2 types of inconsistent responses: (i) baseline reports of ever use which were subsequently contradicted by follow-up reports of never use; and (ii) baseline reports of never use which were contradicted by follow-up reports of use prior to 1994–95.

Results

Among women who reported having a mammogram at baseline, 5.9% (95% confidence interval (CI): 4.6–7.3%) reported at follow-up that they had never had one. Multivariate logistic regression analyses showed that women with such inconsistent responses were more often outside target age groups, from low income households and less likely to report hormone replacement therapy and Pap smear use. Among women reporting never use at baseline and ever use at follow-up, 17.4% (95%CI: 11.7–23.1%) reported their most recent mammogram as occurring prior to 1994–95 (baseline) and such responses were more common among women aged 70+ years and those in poorer health.

Conclusions

Women with inconsistent responses of type (i), i.e., ever users at baseline but never users at follow-up, appeared to exhibit characteristics typical of never users of mammography screening. Although limited by sample size, our preliminary analyses suggest that type (ii) responses are more likely to be the result of recall bias due to competing morbidity and age. Inconsistent responses, if removed from the analyses, may be a greater source of loss to follow-up than deaths/institutionalization or item non-response.
Primary lymphocutaneous nocardiosis in an immunocompetent patient
Authors: Maraki Sofia , Chochlidakis Stavros , Nioti Eleni , Tselentis Yannis
Published: November 2004

Background

Nocardia brasiliensis is a rare human pathogen usually associated with localized cutaneous infections.

Case Presentation

We report a case of primary lymphocutaneous Nocardia brasiliensis infection developed after a bone fracture of the left hand of an otherwise healthy 32-year-old man. Treatment with trimethoprim-sulfamethoxazole given for a total of three months combined with surgical debridement resulted in complete resolution of the infection.

Conclusion

Nocardiosis should be part of the differential diagnosis in patients with sporotrichoid infection, particularly those with a history of outdoor injury. Culture of the affected tissue and antimicrobial susceptibility testing of the isolate should be performed for diagnosis and treatment.
Large bilateral adrenal metastases in non-small cell lung cancer
Authors: Karanikiotis Charisios , Tentes Apostolos Anto , Markakidis Sotirios , Vafiadis Konstantinos
Published: November 2004

Background

The adrenal gland is one of the common sites of metastasis from primary lung cancer. Adrenal metastases are usually unilateral however bilateral adrenal metastases are seen in 10% of all lung cancer patients; of these 2–3% occurs at the initial presentation of non-small cell lung cancer. Secondary tumors can disrupt the structure and function of the adrenal. This can lead to adrenal hemorrhage, which constitutes a life threatening hazard for the patient.

Case presentation

A 59-year-old male presented with persisting abdominal pain. His initial work-up revealed significant anemia, an invasive process in the right upper lobe of the lung and large masses of heterogeneous texture, with hemorrhagic and necrotic elements in both adrenal glands. A biopsy confirmed it to be a large-cell carcinoma of the lungs. The patient developed severe leukocytosis akin to the paraneoplastic syndrome and died suddenly five days after the administration of chemotherapy.

Conclusion

Intratumoral hemorrhage is a rare but life threatening complication of adrenal metastases and should be treated as soon as it has been diagnosed. If adrenalectomy is not feasible, combination chemotherapy should be applied as in metastatic disease. For choosing the appropriate chemotherapeutic regimen it is important to accurately achieve the diagnosis.
Are zinc-bound metallothionein isoforms (I+II and III) involved in impaired thymulin production and thymic involution during ageing?
Authors: Mocchegiani Eugenio , Giacconi Robertina , Cipriano Catia , Muti Elisa , Gasparini Nazzarena , Malavolta Marco
Published: November 2004

Background

With advancing age, thymic efficiency shows progressive decline due to thymic involution allowing impaired cell-mediated immunity and the appearance of age-related diseases. The intrinsic cause of thymic involution is still undefined. Chronic inflammation and high glucocorticoids (GCs) may be involved. However, transgenic mice, with increased GC sensitivity and over expression of GC receptors, display delayed age-associated thymic involution. This fact suggests that other substances may affect thymic involution. Among them, both isoforms of metallothioneins (MTs) I+II and III are the major candidates because their increments leads to organ atrophy in constant stress and are induced by IL-6, which increases in ageing. Enhanced MTs in ageing allows constant sequester of zinc ions and no subsequent zinc release leading to low zinc ion bioavailability for thymic efficiency. This sequester is very limited in very old age. Thus, we have investigated the MTmRNA (I+II and III) in the thymus from young, old and very old mice.

Methods

MTmRNA and IL-6mRNA (RT-PCR) in the thymus from different donors were tested. Concomitantly, TECs proliferation, zinc ion bioavailability (ratio total thymulin/active thymulin), thymulin activity and corticosterone were tested from different donors.

Results

Both isoforms of MTmRNA and IL-6mRNA increase in old thymus coupled with low zinc ion bioavailability, reduced TECs proliferation, impaired thymulin activity and enhanced plasma corticosterone in comparison with young. Conversely, although the thymus is involuted in very old mice because of no changes in thymus weight in comparison to old mice, reduced MTmRNA, especially MT-I+II isoforms, and low IL6mRNA occur. Concomitantly, good zinc ion bioavailability, maintained TECs proliferation, satisfactory thymulin activity and reduced corticosterone are observed in very old mice.

Conclusions

The concomitant increments by high IL-6 of both MT isoforms in the thymus from old mice may be involved in thymic involution because provoking low zinc ion bioavailability, which is relevant for thymic efficiency. By contrast, the limited increments of MTs by low IL-6 induce good zinc ion bioavailability and satisfactory thymic efficiency in very old mice. Therefore, abnormal increased MTs may provoke complete thymic involution during ageing and the possible appearance of age-related diseases. If their increments are instead limited by low inflammation, healthy ageing and longevity may be reached.
Age-related decline in RACK-1 expression in human leukocytes is correlated to plasma levels of dehydroepiandrosterone
Authors: Corsini Emanuela , Racchi Marco , Sinforiani Elena , Lucchi Laura , Viviani Barbara , Rovati Gian Enrico , Govoni Stefano , Galli Corrado L , Marinovich Marina
Published: November 2004

Aging is associated with remodeling of the immune system, contributing to increased incidence of infections, autoimmune diseases, and cancer among the elderly. Alterations in several signal transduction pathways have been reported to play an important role in immunosenescence. We show that peripheral blood leukocytes obtained from old donors (≥65 years) have a significantly reduced expression of receptor for activated C kinase 1 (RACK-1), a protein required for protein kinase C (PKC)-β signaling, as compared with young donors (≤40 years), both in males and females. The decline in RACK-1 immunoboth in reactivity was age-related (Spearman correlation, r=–0.278, P=0.012). All leukocyte subpopulations, namely lympho-monocytes, granulocytes, and B and T cells, showed a similar defect. We also observed a direct correlation between circulating dehydroepiandrosterone (DHEA) and RACK-1 expression in leukocytes (Spearman correlation, r=0.388, P=0.001). Furthermore, in vitro treatment with DHEA resulted in increased RACK-1 expression in leukocytes and lymphocyte proliferation, confirming the role of this hormone in the modulation of its expression and immune functions. A relevant consequence of RACK-1-reduced expression was the observation that release of tumor necrosis factor α following lipopolysaccharide challenge and mitogen-induced lymphocye proliferation, which involves PKC-β activation, was significantly reduced in elderly subjects. Overall, our findings contribute to the understanding of the complex process of immunosenescence and identify age-related loss in immunological responses as partially associated with decreased RACK-1 expression.