bluuebunny/crossref_metadata_2025 huggingface dataset:
Stress and dysmenorrhoea: a population based prospective study
Authors: Wang L , Wang X , Wang W , Chen C , Ronnennberg A G , Guang W , Huang A , Fang Z , Zang T , Wang L , Xu X
Published: November 2004

Background:Dysmenorrhoea is the most common gynaecological disorder in women of reproductive age. Despite the association between stress and pregnancy outcomes, few studies have examined the possible link between stress and dysmenorrhoea.

Aims and Methods:Using a population based cohort of Chinese women, the independent effect of women’s perceived stress in the preceding menstrual cycle on the incidence of dysmenorrhoea in the subsequent cycle was investigated prospectively. The analysis included 1160 prospectively observed menstrual cycles from 388 healthy, nulliparous, newly married women who intended to conceive. The perception of stress and the occurrence of dysmenorrhoea in each menstrual cycle were determined from daily diaries recorded by the women.

Results:After adjustment for important covariates, the risk of dysmenorrhoea was more than twice as great among women with high stress compared to those with low stress in the preceding cycle (OR = 2.4; 95% CI 1.4 to 4.3). The risk of dysmenorrhoea was greatest among women with both high stress and a history of dysmenorrhoea compared to women with low stress and no history of dysmenorrhoea (OR = 10.4, 95% CI 4.9 to 22.3). Stress in the follicular phase of the preceding cycles had a stronger association with dysmenorrhoea than stress in the luteal phase of the preceding cycles.

Conclusion:This study shows a significant association between stress and the incidence of dysmenorrhoea, which is even stronger among women with a history of dysmenorrhoea.
Study on the relation between occupational fenvalerate exposure and spermatozoa DNA damage of pesticide factory workers
Authors: Bian Q , Xu L C , Wang S L , Xia Y K , Tan L F , Chen J F , Song L , Chang H C , Wang X R
Published: November 2004

Aims:To determine sperm nuclear DNA integrity and to investigate the relation between fenvalerate (FE) exposure and spermatozoa DNA damage.

Methods:Sperm DNA fragmentation was detected by a modified alkaline single cell gel electrophoresis (Comet) assay and a terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL) assay. The olive tail moment (OTM) and percentage tail DNA were measured by the Comet assay, and cell positive percentage was measured by the TUNEL assay for DNA damage evaluation.

Results:The DNA integrity of spermatozoa of external and internal control groups were both significantly greater than that of the FE exposed group. The median value of tail DNA percentage in the exposure group was 11.30, which was significantly higher than 5.60 in the internal control group and 5.10 in the external control group. The median value of OTM was 3.80 in the exposure group, significantly higher than 1.50 in the internal control group and 2.00 in the external control group. Mean cell positive was 31.2% in the exposure group, significantly higher than 17.4% in the internal control and 19.6% in the external control groups. Cell positive (%) was significantly correlated with tail DNA percentage and with OTM of whole subjects (n = 63).

Conclusions:Results showed that occupational FE exposure is associated with an increase in sperm DNA damage. A combination of the Comet and TUNEL assays would offer more comprehensive information for a better understanding of sperm DNA damage, and the biological significance of sperm DNA damage in sperm function and male infertility.
The kinetics and the mechanism of oxidative decarboxylation of benzilic acid by acidic permanganate (stopped-flow technique)  An autocatalytic study
Authors: Farokhi Sairabanu A , Nandibewoor Sharanappa T
Published: November 2004

The kinetics of the oxidation of benzilic acid by potassium permanganate in an acidic medium were studied spectrophotometrically. The reaction followed a two-stage process, wherein both stages of the reaction followed first-order kinetics with respect to permanganate ion and benzilic acid. The rate of the reaction increased with an increase in acid concentration. Autocatalysis was observed by one of the products, i.e., manganese(II). A composite mechanism involving autocatalysis has been proposed. The activation parameters of the reaction were calculated and discussed and the reaction constants involved in the mechanisms were calculated. There is a good agreement between the observed and calculated rate constants under different experimental conditions.Key words: oxidation, autocatalysis, benzilic acid, two-stage kinetics.
AWARD LECTURE / CONFÉRENCE D'HONNEUR Prospects for controlling plant fungal diseases  Alternatives based on chemical ecology and biotechnology
Authors: Pedras M Soledade C
Published: November 2004

Plants produce a diverse array of secondary metabolites associated with important defence and resistance mechanisms. In general, within the same plant family the chemical structures of these metabolites are related and suggest common biogenetic precursors. Crucifers are known to produce constitutive and induced tryptophan derived metabolites. Pathogenic fungi can resist such defences utilizing a variety of processes, as for example, enzymatic detoxification. On the other hand, to facilitate their penetration and colonization of the plant tissues, fungal phytopathogens can produce phytotoxic metabolites, some of which are selectively toxic to host-plants. However, plants may be resistant to these pathogens partly due to their ability to detoxify these selective phytotoxins. Nonetheless, the outcome of these interactions frequently favours the pathogen and can lead to enormous yield losses or even major plant epidemics. An overview of some of the most recent studies of metabolic pathways and stress responses in crucifers and several of their pathogens is presented. Potential strategies to prevent and control plant microbial diseases based on chemical ecology studies and biotechnology will be discussed. Key words: phytoalexin, phytotoxin, chemical defence, metabolic detoxification, destruxin B.
Solubility of crystalline nonelectrolyte solutes in organic solvents  Mathematical correlation of 2-methoxybenzoic acid and 4-methoxybenzoic acid solubilities with the Abraham solvation parameter model
Authors: Hoover Kaci R , Stovall Dawn M , Pustejovsky Eric , Coaxum Rodrick , Pop Krisztina , Acree Jr. William E , Abraham Michael H
Published: November 2004

The Abraham solvation parameter model is used to calculate the numerical values of the solute descriptors for 2-methoxybenzoic acid and 4-methoxybenzoic acid from experimental solubilities in organic solvents. The mathematical correlations take the form of [Formula: see text] [Formula: see text] where CS and CW refer to the solute solubility in the organic solvent and water, respectively, CG is a gas phase concentration, E is the solute excess molar refraction, V is the McGowan volume of the solute, A and B are measures of the solute hydrogen-bond acidity and hydrogen-bond basicity, S denotes the solute dipolaritypolarizability descriptor, and L is the logarithm of the solute gas phase dimensionless Ostwald partition coefficient into hexadecane at 298 K. The remaining symbols in the above expressions are known solvent coefficients, which have been determined previously for a large number of gassolvent and watersolvent systems. The Abraham solvation parameter model was found to describe the experimental solubility data and published literature partitioning data of 2-methoxybenzoic acid and 4-methoxybenzoic acid to within overall standard deviations of 0.146 log units and 0.114 log units, respectively.Key words: 2-methoxybenzoic acid solubilities, 4-methoxybenzoic acid solubilities, partition coefficients, molecular solute descriptors, solubility predictions.
A METHOD FOR IDENTIFICATION OF PEAKS IN ENERGY-DISPERSIVE X-RAY SPECTRA
Authors: GERASIMOV S.A.
Published: November 2004

It is found that the ratio of X-ray energies of Kα and K β lines is approximately equal to the ratio of its peak positions in the spectrum. This result can be used for identificaion of peaks in experimental energy-dispersive X-ray spectra.
MULTIWAVELENGTH LIGHT SOURCE WITH INTEGRATED DFB LASER ARRAY AND STAR COUPLER FOR WDM LIGHTWAVE COMMUNICATIONS
Authors: ZAH C.E. , GAMELIN J. , PATHAK B. , FAVIRE F. , LIN P.S.D. , ANDREADAKIS N.C. , BHAT R. , CANEAU C. , CURTIS L. , MAHONEY D.D. , YOUNG W.C. , LEE T.P.
Published: November 2004

We discuss the advantages of wavelength-division-multiplexed (WDM) lightwave systems and the need for monolithically integrated multiwavelength laser arrays. For WDM light-wave systems to be cost effective, it is important to reduce the per-wavelength component cost. By photonic integration, the packaging and the control circuitry will be shared among all the wavelengths. In this paper, we review the multiwavelength laser arrays, the array coupling, and the photonic integration approach. We have demonstrated the monolithic integration of a 21-wavelength multi-quantum-well distributed-feedback laser array with a star coupler and optical amplifiers on the same chip. Operating a packaged module under CW operation, we obtained as many as 15 individual wavelengths simultaneously launched from one output port of the star coupler of this integrated chip into one lensed single-mode fiber. We also characterized the thermal and the electrical crosstalk from the neighboring lasers. This integrated chip stands a good chance of being a compact and low-cost multiwavelength laser source for future WDM lightwave systems.
GaAs HBT RELIABILITY
Authors: SUGAHARA HIROHIKO
Published: November 2004

This paper reviews recent studies on the reliability of GaAs heterojunction bipolar transistors (HBTs), mainly carbon-doped-base AlGaAs/GaAs HBTs, and discusses degradation modes in these devices.

The carbon-doped-base AlGaAs/GaAs HBTs generally have more stable current-voltage characteristics than beryllium-doped-base ones. However, even carbon-doped-base HBTs show a decrease in the current gain due to an anomalous increase in the base current that occurs under high-current stress. The estimated ohmic contacts of these HBTs show that their stability is high enough under actual operating conditions.

Bias stress testing has shown that two factors dominate the reliability of carbon-doped-base AlGaAs/GaAs HBTs: the material and the passivation. HBTs with an AlGaAs surface passivation layer on the extrinsic base region exhibit a longer life than those without one. The base current ideality factor of short-lived HBTs increases to larger than 2 during bias stress testing, suggesting that the origin of the excess base current cannot be simply explained by a space-charge recombination process. The reported activation energies are distributed around 0.5 eV, which is almost the same as those for AlGaAs/GaAs laser diodes. Cross-sectional TEM analysis has revealed that current-induced defects are formed in the base layer. The indium-incorporated-base HBTs show a median life of longer than 15,000 hours at a junction temperature of 215°C with a collector current density of 50 kA/cm 2, implying that GaAs HBTs have sufficient reliability for very-high-speed communication systems.
SILICON:GERMANIUM HETEROJUNCTION BIPOLAR TRANSISTORS: FROM EXPERIMENT TO TECHNOLOGY
Authors: MEYERSON B.S. , HARAME D.L. , STORK J. , CRABBE E. , COMFORT J. , PATTON G.
Published: November 2004

Recent advances in thin film growth techniques, notably the maturation of low temperature silicon epitaxy, have enabled the routine fabrication of highly controlled dopant and silicon:germanium alloy profiles. These capabilities, combined with refinements in heterojunction bipolar transistor designs, have led to the first integrated circuits in the silicon:germanium materials system. Utilizing a commercial (Leybold-AG) UHVCVD tool for SiGe epitaxy on a standard 8" CMOS line, medium scale integration has been achieved, with the first IC components being SiGe HBT based 1 Ghz, 12 bit, digital to analog converters.
SELECTING AFFINE MAPPINGS BASED ON PERFORMANCE ESTIMATION
Authors: KELLY WAYNE , PUGH WILLIAM
Published: November 2004

In previous work, we presented a framework for unifying iteration reordering transformations such as loop interchange, loop distribution, loop skewing and statement reordering. The framework provides a uniform way to represent and reason about transformations. However, it does not provide a way to decide which transformation(s) should be applied to a given program. This paper describes a way to make such decisions within the context of the framework. The framework is based on the idea that a transformation can be represented as an affine mapping from the original iteration space to a new iteration space. We show how we can estimate the performance of a program by considering only the mapping from which it was produced. We also show how to produce a lower bound on performance given only a partially specified mapping. Our ability to estimate performance directly from mappings and to do so even for partially specified mappings allows us to efficiently find mappings which will produce good code.
TRANSFORMATION OF NESTED LOOPS WITH MODULO INDEXING TO AFFINE RECURRENCES
Authors: BALASA FLORIN , FRANSSEN FRANK H.M. , CATTHOOR FRANCKY V.M. , MAN HUGO J. DE
Published: November 2004

For multi-dimensional (M-D) signal and data processing systems, transformation of algorithmic specifications is a major instrument both in code optimization and code generation for parallelizing compilers and in control flow optimization as a preprocessor for architecture synthesis. State-of-the-art transformation techniques are limited to affine index expressions. This is however not sufficient for many important applications in image, speech and numerical processing. In this paper, a novel transformation method is introduced, oriented to the subclass of algorithm specifications that contains modulo expressions of affine functions to index M-D signals. The method employs extensively the concept of Hermite normal form. The transformation method can be carried out in polynomial time, applying only integer arithmetic.
QCD AND ASYMPTOTIC FREEDOM: PERSPECTIVES AND PROSPECTS
Authors: WILCZEK FRANK
Published: November 2004

QCD is now a mature theory, and it is possible to begin to view its place in the conceptual universe of physics with an appropriate perspective. There is a certain irony in the achievements of QCD. For the problems which initially drove its development — specifically, the desire to understand in detail the force that holds atomic nuclei together, and later the desire to calculate the spectrum of hadrons and their interactions — only limited insight has been achieved. However, I shall argue that QCD is actually more special and important a theory than one had any right to anticipate. In many ways, the importance of the solution transcends that of the original motivating problems.

After elaborating on these quasiphilosophical remarks, I discuss two current frontiers of physics that illustrate the continuing vitality of the ideas.

The recent wealth of beautiful precision experiments measuring the parameters of the standard model have made it possible to consider the unification of couplings in unprecedented quantitative detail. One central result emerging from these developments is a tantalizing hint of virtual supersymmetry.

The possibility of phase transitions in matter at temperatures of order ~102 MeV, governed by QCD dynamics, is of interest from several points of view. Besides having a certain intrinsic grandeur, the question “Does the nature of matter change qualitatively, as it is radically heated?” is important for cosmology, relevant to planned high-energy heavy-ion collision experiments, and provides a promising arena for numerical simulations of QCD. Recent numerical work seems to be consistent with expectations suggested by renormalization group analysis of the potential universality classes of the QCD chiral phase transition; specifically, that the transition is second-order for two species of massless quarks but first order otherwise. There is an interesting possibility of long-range correlations in heavy ion collisions due to the creation of large regions of the misaligned chiral condensate.

Finally, at the end, there is a brief discussion on the relation between scaling violations and running of the coupling. Some statements made later in the conference seemed to indicate that the relationship between these concepts is commonly misunderstood, so I’m smuggling this bit in even though it wasn’t part of the original talk.
LOW Q2, HIGH ν NEUTRINO PHYSICS (CVC, PCAC, HADRON DOMINANCE)
Authors: KOPELIOVICH B.Z. , MARAGE P.
Published: November 2004

A critical review is given of the main theoretical bases and of the experimental results of neutrino physics at low four-momentum transfer (Q2≤1 GeV 2) and high energy transfer (ν≥a few GeV).

The theoretical predictions for the vector current are first presented, using the CVC hypothesis and the hadron dominance model of Piketty and Stodolsky. The predictions for the axial current at very small Q2 values are discussed on the basis of the PCAC hypothesis (Adler’s theorem), and extended for Q2≲1 GeV 2 in the lines of hadron dominance; the structure of the longitudinal component of the axial current is particularly discussed.

Experimental data on neutrino and antineutrino interactions on nucleons are reviewed, in particular the total cross sections, which provide good tests of the PCAC hypothesis and of the model of Piketty and Stodolsky; also reviewed are the data on diffractive production of π, ρ and a1 mesons.

The observation of shadowing, from the comparison of the total cross sections of neutrinos and antineutrinos on neon and deuterium nuclei, is discussed in detail with emphasis on the predictions of the PCAC hypothesis, in the framework of the Glauber-Gribov model.

Finally a review is given of the results on coherent neutrino and antineutrino interactions on atomic nuclei:

• π meson production, by charged and neutral currents in several experiments, providing a detailed test of the PCAC hypothesis;

• ρ meson production, providing a test of the CVC hypothesis in weak interactions;

• a1 meson or nonresonant ρπ system production, allowing the study of the weak axial current structure.
ON THE INVERSE PROBLEM OF LAGRANGIAN SUPERMECHANICS
Authors: IBORT L. A. , LANDI G. , MARÍN-SOLANO J. , MARMO G.
Published: November 2004

The inverse problem of Lagrangian supermechanics is investigated. A set of necessary and sufficient conditions for a system of second order differential equations in superspace to derive from a (possibly nonregular) super-Lagrangian function are given. The harmonic superoscillator is revisited and a family of even and odd alternative super-Lagrangians are constructed for it. Finally, we comment on the existence of recursion operators.
COMPLEXIFIED THEORY OF POSITIVE-FREQUENCY MAXWELL-DIRAC FIELDS
Authors: CARDOSO J.G.
Published: November 2004

We present a method whereby the equations of motion yielding the explicit two-component spinor form of the complete Maxwell-Dirac theory in complex Minkowski space may be directly derived from two variational principles. One of these dynamical statements gives rise to the first half of the electromagnetic theory which particularly appears as the equations of motion involving a slightly modified version of the free part of the conventional Maxwell Lagrangian density. The other principle actually involves a holomorphic two-spinor expression for the full Maxwell-Dirac Lagrangian density which leads to the second half along with the Dirac equations that carry the relevant covariant derivative operator. It is shown explicitly how the Bianchi identities of the complete theory can be established in a manifestly covariant way. A system of essentially equivalent wave equations for positive-frequency photons and electrons is then exhibited. In particular, we make use of certain skew-symmetric operators to obtain an extended form of the Feynman-Gell-Mann equations.
STRING FINE-TUNING
Authors: SAVVIDY G.K. , SAVVIDY K.G.
Published: November 2004

We develop further a new geometrical model of a discretized string, proposed in Ref. 1, and establish its basic physical properties. The model can be considered as the natural extension of the usual Feynman amplitude of the random walks to random surfaces. Both amplitudes coincide in the case, when the surface degenerates into a single particle world line. We extend the model to open surfaces as well. The boundary contribution is proportional to the full length of the boundary, and the coefficient of proportionality can be treated as a hopping parameter of the quarks. In the limit when this parameter tends to infinity, the theory is essentially simplified. We prove that the contribution of a given triangulation to the partition function is finite and have found the explicit form for the upper bound. The question of the convergence of the full partition function remains open. In this model the string tension may vanish at the critical point, if the last one exists, and possesses a nontrivial scaling limit. The model contains hidden fermionic variables and can be considered as an independent model of hadrons.
PHASE TRANSITION IN CONTINUOUS SYMMETRY MODEL IN GENERAL DIMENSIONS — FIXED DIMENSION RENORMALIZATION GROUP APPROACH
Authors: HOLOVATCH YU.
Published: November 2004

Critical exponents of the O(m)-symmetric model are calculated in the case when dimension of space is noninteger. Calculations are performed in the frames of the field-theoretical approach using the three-loop approximation. Renormalization group functions in the Callan-Symanzik scheme are considered directly in noninteger dimensions. Perturbation theory expansions are resummed with the use of Padé-Borel transformation.
OFFLINE SIGNATURE VERIFICATION AND IDENTIFICATION USING DISTANCE STATISTICS
Authors: KALERA MEENAKSHI K. , SRIHARI SARGUR , XU AIHUA
Published: November 2004

This paper describes a novel approach for signature verification and identification in an offline environment based on a quasi-multiresolution technique using GSC (Gradient, Structural and Concavity) features for feature extraction. These features when used at the word level, instead of the character level, yield promising results with accuracies as high as 78% and 93% for verification and identification, respectively. This method was successfully employed in our previous theory of individuality of handwriting developed at CEDAR — based on obtaining within and between writer statistical distance distributions. In this paper, exploring signature verification and identification as offline handwriting verification and identification tasks respectively, we depict a mapping from the handwriting domain to the signature domain.
PARALLEL ALGORITHMS FOR LINE DETECTION ON A PYRAMID ARCHITECTURE
Authors: KAVIANPOUR A. , BAGHERZADEH N.
Published: November 2004

This paper considers the problem of detecting lines in images using a pyramid architecture. The approach is based on the Hough Transform calculation. A pyramid architecture of size n is a fine-grain architecture with a mesh base of size [Formula: see text] processors each holding a single pixel of the image. The pyramid operates in an SIMD mode. Two algorithms for computing the Hough Transform are explained. The first algorithm initially uses different angles, θj’s, and its complexity is O(k+log n) with O(m) storage requirement. The second algorithm computes the Hough Transform in a pipeline fashion for each angle θj at a time. This method produces results in O(k * log n) time with O(1) storage, where k is the number of θj angles, m is the number of ρi normal distances from the origin, and n is the number of pixels. A simulation program is also described.
AN AUTOREGRESSIVE APPROACH TO SURFACE TEXTURE ANALYSIS
Authors: MITAL DINESH P. , LENG GOH WEE
Published: November 2004

The use of autoregressive models in textual analysis holds great potential. Coupling the technique to a circular neighbourhood set imparts a rotational invariant property to it. This was demonstrated by Kashyap and Khotanzad in their model called the Circular Symmetric Autogressive (CSAR) Random Field model. The short-coming in this very ingenious proposal is that it is set in a background of square pixels and the rotational invariant property of the model fails in cases when the aspect ratio of the pixels are not at unity. This paper proposes a major modification to the CSAR to render the model rotational invariant under all configurations of pixel implementation. It is based on the area segments covered by a circle set in a 3×3 neighbourhood. We call it the Circular Area Autoregressive (CAAR) model. The results obtained from the CAAR showed much better consistency over that of the CSAR when a non-square pixel image was used.
A TWO-DIMENSIONAL SHAPE RECOGNITION SCHEME BASED ON PRINCIPAL COMPONENT ANALYSIS
Authors: CHANG CHIN-CHEN , CHEN YAW-WEN , BUEHRER DANIEL JAMES
Published: November 2004

In this paper, we propose a simple, but efficient method to recognize two-dimensional shapes without regard to their translation, rotation, and scaling factors. In our scheme, we use all of the boundary points to calculate the first principal component, which is the first shape feature. Next, by dividing the boundary points into groups by projecting them onto the first principal component, each shape is partitioned into several blocks. These blocks are processed separately to produce the remaining shape features. In shape matching, we compare two shapes by calculating the difference between the two sets of features to see whether the two shapes are similar or not.

The amount of storage used to represent a shape in our method is fixed, unlike most other shape recognition schemes. The time complexity of our shape matching algorithm is also O(n), where n is the number of blocks. Therefore, the matching algorithm takes little computation time, and is independent of translation, rotation, and scaling of shapes.
BACKGROUND STRUCTURE IN DOCUMENT IMAGES
Authors: BAIRD HENRY S.
Published: November 2004

A method for analyzing the structure of the white background in document images is described, along with applications to the problem of isolating blocks of machine-printed text. The approach is based on computational-geometry algorithms for off-line enumeration of maximal white rectangles and on-line rectangle unification. These support a fast, simple, and general heuristic for geometric layout segmentation, in which white space is covered greedily by rectangles until all text blocks are isolated. Design of the heuristic can be substantially automated by an analysis of the empirical statistical distribution of properties of covering rectangles: for example, the stopping rule can be chosen by Rosenblatt’s perceptron training algorithm. Experimental trials show good behavior on the large and useful class of textual Manhattan layouts. On complex layouts from English-language technical journals of many publishers, the method finds good segmentations in a uniform and nearly parameter-free manner. On a variety of non-Latin texts, some with vertical text lines, the method finds good segmentations without prior knowledge of page and text-line orientation.
AN ALGORITHM FOR MATCHING OCR-GENERATED TEXT STRINGS
Authors: RICE STEPHEN V. , KANAI JUNICHI , NARTKER THOMAS A.
Published: November 2004

When optical character recognition (OCR) devices process the same page image, they generate similar text strings. Differences are due to recognition errors. A page of text rarely contains long repeated substrings; therefore, N strings generated by OCR devices can be quickly matched by detecting long common substrings. An algorithm for matching an arbitrary number of strings based on this principle is presented. Although its worst-case performance is O(Nn2), its performance in practice has been observed to be O(Nn log n), where n is the length of a string. This algorithm has been successfully used to study OCR errors, to determine the accuracy of OCR devices, and to implement a voting algorithm.
INTEGRATION OF GEOMETRIC AND NON-GEOMETRIC ATTRIBUTES FOR FAST OBJECT RECOGNITION
Authors: GREWE LYNNE , KAK AVI
Published: November 2004

Both man-made and natural objects are described by both their geometric shapes and by their non-geometric attributes such as color. The objective of the proposed research is to create a system which integrates geometric and non-geometric attribute information for fast 3D model-based object recognition. Hashing is employed in a hypothesize and verify approach to the 3D model-based object recognition problem. Viewpoint independent attributes are used in the hypothesis generation stage to eliminate model objects from consideration during hypothesis formation.

Utilizing more than one attribute in the proposed hashing scheme helps to ensure a reduction in the actual execution time for object recognition over a larger number of model bases. A nice feature of the system is that new object attributes can be added with relative ease. Issues concerning the ranking of attributes by their distinctiveness with respect to the objects in the model base are discussed. Current work on the use of an information theoretic measure in the design of an optimal multiple attribute hash table is presented.
A REAL-TIME SCHEDULING ALGORITHM FOR TASKS WITH RESOURCE CONTENTION ON A MULTIPROCESSOR
Authors: RYANG DAL-SOO , PARK KYU HO
Published: November 2004

Our scheduling algorithm is based on a general model with timing and resource constraints which permits OR requests. In order to keep run-time costs low, we propose an algorithm that does not search the whole search space. This paper defines two measures, survivability and impact, for scheduling tasks conflicted for some resources. The survivability is a metric to show how urgent a task is, and how constrained it is by its resources. The impact of a resource for a task measures how much other tasks are influenced by the allocation of the resource to the task. Our scheduling algorithm uses the survivability to schedule tasks on multiple processors. After a task is picked out to be run in a time slice using the survivability, the least impact resources are allocated from several alternative resources.
MATISSE: A KNOWLEDGE-BASED TEAM PROGRAMMING ENVIRONMENT
Authors: GARG PANKAJ K. , PHAM THUAN Q. , BEACH BRIAN , DESHPANDE ANAND , ISHIZAKI AUDREY , WENTZEL KEVIN , FONG WENDY
Published: November 2004

The downstream activities of large scale software systems life-cycle require team effort of several people over extended time periods. Current computing environments, exemplified by Unix, provide limited support for such team activities. Matisse is a knowledge-based team programming environment that addresses this issue.

Matisse models source code, associated documents, people, and tasks as objects in an information system. Relationships between these objects provide associative information retrieval and navigational support; rules defined on object attributes facilitate team coordination and configuration management.

We describe the design, implementation, and experimental use of Matisse. Matisse represents a novel information management architecture for team programming: It uses database technology for team information management and expert system technology for individual information management; some experimental data on accesses from the individual to the team information space is presented. Three hard scenarios: semiautomatic design history maintenance, dynamic object composition, and adaptive use of existing software, illustrate the power of Matisse, with respect to team programming, over traditional programming environments.
APPLICATIONS OF PHOTOREFRACTIVE VOLUME HOLOGRAPHY IN OPTICAL COMPUTING
Authors: GU C. , YEH P.
Published: November 2004

After a brief review of the photorefractive effect, we describe three examples of the applications in optical computing using photorefractive volume holography. These are 3-dimensional optical storage, parallel optical matrix processor, and multiwavelength optical half-adder. For the 3-dimensional optical storage, we consider some fundamental issues in photorefractive memory, including the storage capacity and the dynamic range. We also discuss the photorefractive noise gratings formed during a multiple exposure schedule. These fundamental issues in photorefractive storage are important in understanding the potentials and limitations of optical memory systems. For parallel optical matrix processing, we propose and demonstrate a novel method of matrix-matrix application using grating degeneracy in photorefractive media in conjunction with incoherent laser source arrays. For multiwavelength optical half-adder, we describe photorefractive logic gates and their application in the summation of binary numbers.
NEAR INFRARED NONLINEAR OPTICAL PHASE CONJUGATION IN PHOTOREFRACTIVE CRYSTALS AND SEMICONDUCTOR MATERIALS PART II: MATERIALS AND APPLICATIONS
Authors: SONDERER N. , GÜNTER P.
Published: November 2004

Materials used in experiments for optical wavefront reversing as a tool for phase aberration correction are reviewed. The recent experimental results in optical phase conjugation in the near infrared are summarized. Photorefractive oxides and their feasibility to use these materials in this wavelength range as well as bulk semiconductors with the corresponding bandgap and dopant are reviewed by listing the nonlinear optical properties and the measured results in optical phase conjugating experiments. Advantages of each material is confronted with the drawbacks. Different enhancement techniques are presented in order to improve the corresponding material parameters. Several applications and experiments are discussed.
QUERY EVALUATION IN PARTITIONED DISJUNCTIVE DEDUCTIVE DATABASES
Authors: YAHYA ADNAN , MINKER JACK
Published: November 2004

Query evaluation in disjunctive deductive databases is in general computationally hard. The class of databases for which the process is tractable is severely limited. The complexity of the process depends on the structure of the database as well as on the type of query being evaluated. In this paper we study the issue of simplified query processing in disjunctive deductive databases. We address the possibility of evaluating general queries by independently processing their atomic components and describe the class of databases for which this approach is possible. We also discuss the issue of dividing a disjunctive deductive database into a set of disjoint components then answering queries and computing database completions by combining the results obtained against the individual components. Some practical special cases are considered. The methods developed in this paper can be utilized to introduce parallelism into the query evaluation process.
ON RIBBON PRESENTATIONS OF RIBBON KNOTS
Authors: YASUDA TOMOYUKI
Published: November 2004

A ribbon n-knot Kn is constructed by attaching m bands to m + 1n-spheres in the Euclidean (n + 2)-space. There are many way of attaching them; as a result, Kn has many presentations which are called ribbon presentations. In this note, we will induce a notion to classify ribbon presentations for ribbon n-knots of m-fusions (m ≥ 1, n ≥ 2), and show that such classes form a totally ordered set in the case of m = 2 and a partially ordered set in the case of m ≥ 1.
TWIST SEQUENCES AND VASSILIEV INVARIANTS
Authors: TRAPP ROLLAND
Published: November 2004

In this paper we describe a difference sequence technique, hereafter referred to as the twist sequence technique, for studying Vassiliev invariants. This technique is used to show that Vassiliev invariants have polynomial growth on certain sequences of knots. Restrictions of Vassiliev invariants to the sequence of (2, 2i + 1) torus knots are characterized. As a corollary it is shown that genus, crossing number, signature, and unknotting number are not Vassiliev invariants. This characterization also determines the topological information about (2, 2i + 1) torus knots encoded in finite-type invariants. The main result obtained is that the complement of the space of Vassiliev invariants is dense in the space of all numeric knot invariants. Finally, we show that the uniform limit of a sequence of Vassiliev invariants must be a Vassiliev invariant.
GROWTH MESSAGES IN PLANTS: PRINCIPLE OF A POSSIBLE MODELLING, AND FURTHER EXPERIMENTAL CHARACTERISTICS
Authors: DESBIEZ MARIE-ODILE , MIKULECKY DONALD , THELLIER MICHEL
Published: November 2004

When plantlets of Bidens pilosa L. are subjected to a mechanical stimulation by pricking one of their cotyledons, this has no apparent effect on the growth of the buds at the axil of the cotyledons (cotyledonary buds), which remain quiescent; but it leads to a latent, irreversible asymmetry of these two buds (process STO). When the plant apexes are removed after a time lag, Δt, this allows the cotyledonary buds to start to grow. Depending on a variety of signals received by the plants, these plants either retrieve (process RCL) the stored asymmetry (in which case the growth rate of the bud at the axil of the non-pricked cotyledon is statistically more rapid than that of the other bud) or not. With Δt≤2 days, the retrieval can be easily reversed “on”/“off”, and conversely. Here we show that a relatively simple model, involving a diffusion/reaction mechanism, can give account of the characteristic features of these processes. The model also predicts that situations may exist where the retrieval will be locked either “on” or “off”, instead of being easily reversible. It is shown experimentally that increasing Δt between plant stimulation and removal of the apex, will actually lock the retrieval process, “on” or “off” depending on the experimental conditions.
ON MODAL LOGIC INTERPRETATION OF POSSIBILITY THEORY
Authors: KLIR GEORGE J. , HARMANEC DAVID
Published: November 2004

This paper is a continuation in a series of papers started by Resconi et. al. [8] in which we try to develop interpretations of various uncertainty theories within the framework of standard modal logic. In this paper, we deal with possibility theory. We suggest an interpretation of possibility measures and necessity measures and show that this interpretation is complete for rational-valued measures.
HYSTERESIS CHARACTERIZATION BY A FUZZY LEARNING ALGORITHM
Authors: YEH EDGE C. , LU SHAO HOW
Published: November 2004

In this paper, the hysteresis characterization in fuzzy spaces is presented by utilizing a fuzzy learning algorithm to generate fuzzy rules automatically from numerical data. The hysteresis phenomenon is first described to analyze its underlying mechanism. Then a fuzzy learning algorithm is presented to learn the hysteresis phenomenon and is used for predicting a simple hysteresis phenomenon. The results of learning are illustrated by mesh plots and input-output relation plots. Furthermore, the dependency of prediction accuracy on the number of fuzzy sets is studied. The method provides a useful tool to model the hysteresis phenomenon in fuzzy spaces.
THE NEW AUDACIOUS TECHNOPRENEURS
Authors: TANG HUNG-KEI , YEO KHIM-TECK
Published: November 2004

This paper begins by introducing what other researchers have learnt on the subject of technology-based entrepreneurs and their start-ups. We coined the new term technopreneurs to denote this special type of entrepreneurs. The metaphor of an airplane taking off from a runway is used to describe the precarious state of a high-tech start-up company. Three new cases of technopreneurs, Sim Wong Hoo of Creative Technology, Robin Lau of Excel Machine Tools and Henry Yuen of Gemstar Development, whose businesses took off recently were investigated with the aim of finding the enabling forces for the successful take-off. Four enabling forces identified are the audacious technopreneurs, perceptive opportunities pursuers, core founding teams and enabling agents. Technopreneurs’ audacity are backed by their strong capabilities in relevant technologies.
Basolateral Mg2+/Na+ exchange regulates apical nonselective cation channel in sheep rumen epithelium via cytosolic Mg2+
Authors: Leonhard-Marek Sabine , Stumpff Friederike , Brinkmann Inge , Breves Gerhard , Martens Holger
Published: November 2004

High potassium diets lead to an inverse regulation of sodium and magnesium absorption in ruminants, suggesting some form of cross talk. Previous Ussing chamber experiments have demonstrated a divalent sensitive Na+ conductance in the apical membrane of ruminal epithelium. Using patch-clamped ruminal epithelial cells, we could observe a divalent sensitive, nonselective cation conductance (NSCC) with K+ permeability > Cs+ permeability > Na+ permeability. Conductance increased and rectification decreased when either Mg2+ or both Ca2+ and Mg2+ were removed from the internal or external solution or both. The conductance could be blocked by Ba2+, but not by tetraethylammonium (TEA). Subsequently, we studied this conductance measured as short-circuit current ( Isc) in Ussing chambers. Forskolin, IBMX, and theophylline are known to block both Isc and Na transport across ruminal epithelium in the presence of divalent cations. When the NSCC was stimulated by removing mucosal calcium, an initial decrease in Isc was followed by a subsequent increase. The cAMP-mediated increase in Isc was reduced by low serosal Na+ and serosal addition of imipramine or serosal amiloride and depended on the availability of mucosal magnesium. Luminal amiloride had no effect. Flux studies showed that low serosal Na+ reduced 28Mg fluxes from mucosal to serosal. The data suggest that cAMP stimulates basolateral Na+/Mg2+ exchange, reducing cytosolic Mg. This increases sodium uptake through a magnesium-sensitive NSCC in the apical membrane. Likewise, the reduction in magnesium uptake that follows ingestion of high potassium fodder may facilitate sodium absorption, as observed in studies of ruminal osmoregulation. Possibly, grass tetany (hypomagnesemia) is a side effect of this useful mechanism.
Iron chelation and a free radical scavenger suppress angiotensin II-induced upregulation of TGF-β1 in the heart
Authors: Saito Kan , Ishizaka Nobukazu , Aizawa Toru , Sata Masataka , Iso-o Naoyuki , Noiri Eisei , Mori Ichiro , Ohno Minoru , Nagai Ryozo
Published: November 2004

Long-term administration of angiotensin II causes myocardial loss and cardiac fibrosis. We previously found iron deposition in the heart of the angiotensin II-infused rat, which may promote angiotensin II-induced cardiac damage. In the present study, we have investigated whether an iron chelator (deferoxamine) and a free radical scavenger (T-0970) affect the angiotensin II-induced upregulation of transforming growth factor-β1 (TGF-β1). Angiotensin II infusion for 7 days caused a robust increase in TGF-β1 mRNA expression in vascular smooth muscle cells, myofibroblast-like cells, and migrated monocytes/macrophages. T-0970 and deferoxamine suppressed the upregulation of TGF-β1 mRNA and reduced the extent of cardiac fibrosis in the heart of rats treated with angiotensin II. These agents blocked the angiotensin II-induced upregulation of heme oxygenase-1, a potent oxidative and cellular stress-responsive gene, but they did not significantly affect systolic blood pressure or plasma levels of aldosterone. In addition, T-0970 and deferoxamine suppressed the angiotensin II-induced upregulation of monocyte chemoattractant protein-1 in the heart. These results collectively suggest that iron and the iron-mediated generation of reactive oxygen species may contribute to angiotensin II-induced upregulation of profibrotic and proinflammatory genes, such as TGF-β1 and monocyte chemoattractant protein-1.
17β-Estradiol downregulates tissue angiotensin-converting enzyme and ANG II type 1 receptor in female rats
Authors: Dean Stephanie A. , Tan Junhui , O'Brien Edward R. , Leenen Frans H. H.
Published: November 2004

Estrogens have been implicated in both worsening and protecting from cardiovascular disease. The effects of 17β-estradiol (E2) on the cardiovascular system may be mediated, at least in part, by its modulation of local tissue renin-angiotensin systems (RAS). We assessed two critical components, angiotensin-converting enzyme (ACE) and ANG II type 1 receptor (AT1R), in the heart, lung, abdominal aorta, adrenal, kidney, and brain in four groups of female Wistar rats ( n = 5–6/group): 1) sham ovariectomized, 2) ovariectomized (OVX) treated with subcutaneous vehicle, 3) OVX treated with 25 μg/day (regular) E2 subcutaneously, and 4) OVX treated with 250 μg/day (high) subcutaneous E2 for 2 or 5 wk. After 2 wk, plasma ACE activity was not altered by OVX, but it was 34–38% lower in OVX + regular E2 and OVX + high E2 rats compared with sham OVX rats, and these decreases were no longer present after 5 wk. After 5 wk, OVX alone increased ACE activity and binding densities, and AT1R binding densities by 15–100% in right ventricle, left ventricle (LV), kidney, lung, abdominal aorta, adrenal and several cardiovascular regulatory nuclei in the brain. These effects were, for the most part, prevented by regular E2 replacement and were reversed to decreases by high E2 treatment. This regulation of tissue ACE and AT1R is significant as the activity of these tissue RAS contributes to the pathogenesis and/or progression of hypertension, atherosclerosis, and LV remodeling after myocardial infarction.
Modulatory Effect of Substance P to the Brain Stem Locomotor Command in Lampreys
Authors: Brocard Frédéric , Bardy Cédric , Dubuc Réjean
Published: November 2004

Substance P initiates locomotion when injected in the brain stem of mammals. This study examined the possible role of this peptide on the supraspinal locomotor command system in lampreys. Substance P was bath applied or locally injected into an in vitro isolated brain stem, and the effects of the drug were examined on reticulospinal cells and on the occurrence of swimming in a semi-intact preparation. Bath applications of substance P induced sustained depolarizations occurring rhythmically in intracellularly recorded reticulospinal cells. Spiking activity was superimposed on the depolarizations and swimming was induced. The sustained depolarizations were abolished by tetrodotoxin, and substance P did not affect the membrane resistance of reticulospinal cells nor their firing properties, suggesting that it did not directly effect reticulospinal cells. To establish where the effects were exerted, successive lesions of the brain stem were made as well as local applications of the drug in the brain stem. Removing the mesencephalon abolished the sustained depolarizations, whereas large ejections of the drug in the mesencephalon excited reticulospinal cells and elicited bouts of swimming. More local injections into the mesencephalic locomotor region (MLR) also elicited swimming. After an injection of substance P, the current threshold needed to induce locomotion by MLR stimulation was decreased, and the size of the postsynaptic responses of reticulospinal cells to MLR stimulation was increased. Substance P also reduced the frequency of miniature spontaneous postsynaptic currents in reticulospinal cells. Taken together, these results suggest that substance P plays a neuromodulatory role on the brain stem locomotor networks of lampreys.