bluuebunny/crossref_metadata_2025_split huggingface dataset:
Breathlessness after percutaneous biliary drainage
Authors: Patel H , Hindle K S , Tsavellas G , Huang A 
Published: July 2002

Abstract
A 77 year old woman presented with painless progressive jaundice and weight loss. She also had generalised pruritus and was passing dark urine and pale stools. On examination there was a palpable right upper quadrant abdominal mass. Plasma bilirubin level was 56 μmol/l and alkaline phosphatase was 350 U/l. Serum amylase was within normal limits. Abdominal ultrasound scan showed a dilated biliary tree and a distended gallbladder but there was no evidence of gallstones. Abdominal computed tomography was performed (fig 1). The patient underwent an endoscopic retrograde cholangiopancreaticogram (ERCP) and insertion of a biliary stent, with resolution of the jaundice.
Exposure of hospitality workers to environmental tobacco smoke
Authors: Bates M N , Fawcett J , Dickson S , Berezowski R , Garrett N 
Published: July 2002

Objective:To determine quantitatively the extent of exposure of hospitality workers to environmental tobacco smoke (ETS) exposure during the course of a work shift, and to relate these results to the customer smoking policy of the workplace.Subjects:Three categories of non-smoking workers were recruited: (1) staff from hospitality premises (bars and restaurants) that permitted smoking by customers; (2) staff from smokefree hospitality premises; and (3) government employees in smokefree workplaces. All participants met with a member of the study team before they began work, and again at the end of their shift or work day. At each meeting, participants answered questions from a standardised questionnaire and supplied a saliva sample.Main outcome measures:Saliva samples were analysed for cotinine. The difference between the first and second saliva sample cotinine concentrations indicated the degree of exposure to ETS over the course of the work shift.Results:Hospitality workers in premises allowing smoking by customers had significantly greater increases in cotinine than workers in smokefree premises. Workers in hospitality premises with no restrictions on customer smoking were more highly exposed to ETS than workers in premises permitting smoking only in designated areas.Conclusions:Overall, there was a clear association between within-shift cotinine concentration change and smoking policy. Workers in premises permitting customer smoking reported a higher prevalence of respiratory and irritation symptoms than workers in smokefree workplaces. Concentrations of salivary cotinine found in exposed workers in this study have been associated with substantial involuntary risks for cancer and heart disease.
INFINITE DIMENSIONAL ALGEBRAS AND 2+1 DIMENSIONAL FIELD THEORY: YET ANOTHER VIEW OF gl(∞) SOME NEW ALGEBRAS
Authors: HOPPE JENS 
Published: July 2002

Over the past years, associative algebras have come to play a major role in several areas of theoretical physics. Firstly, it has been realized that Yang Baxter algebras [1] constitute the relevant structure underlying 1+1 dimensional integrable models; in addition, their relation to braid groups, the theory of knots and links, and the exchange algebras of 1+1 dimensional conformal field theories [2] has been quite well understood by now. Secondly, deformations of Poisson structures that appeared in 2+1 dimensional field theories as infinite dimensional symmetry algebras possess underlying associative structures, which have also been studied in some detail (concerning higher spin theories see, e.g., [3, 4] and references therein, concerning the enveloping algebra of sl(2, C) see, e.g., [5], concerning deformations of diff AT2 — the Lie algebra of infinitesimal area preserving diffeomorphisms of the Torus — see [6, 7, 8, 9]). Ideas on how both investigations could eventually converge (i.e., a relation between 2+1 and 1+1 dimensions) have, e.g., been expressed in [10]. As indicated by the two subtitles there will be two parts to my paper: the first one presents a view on something I met long ago [11], and recently got interested in again [5, 7, 9, 12], while the second part introduces some algebraic structures that seem to be interesting, and possibly new.
REPARAMETRIZATION-INVARIANT PATH INTEGRAL IN GR AND "BIG BANG" OF QUANTUM UNIVERSE
Authors: PAWLOWSKI M. , PERVUSHIN V. N. 
Published: July 2002

The reparametrization-invariant generating functional for the unitary and causal perturbation theory in general relativity in a finite space–time is obtained. The region of validity of the Faddeev–Popov–DeWitt functional is studied. It is shown that the invariant content of general relativity as a constrained system can be covered by two "equivalent" unconstrained systems: the "dynamic" (with "dynamic" evolution parameter as the metric scale factor) and "geometric" (given by the Levi–Civita type canonical transformation to the action-angle variables where the energy constraint converts into a new momentum). "Big Bang," the Hubble evolution, and creation of matter fields by the "geometric" vacuum are described by the inverted Levi–Civita transformation of the geomeric system into the dynamic one. The particular case of the Levi–Civita transformations are the Bogoliubov ones of the particle variables (diagonalizing the dynamic Hamiltonian) to the quasiparticles (diagonalizing the equations of motion). The choice of initial conditions for the "Big Bang" in the form of the Bogoliubov (squeezed) vacuum reproduces all stages of the evolution of the Friedmann–Robertson–Walker universe in their conformal (Hoyle–Narlikar) versions.
STUDY OF LOCAL STRUCTURE IN UNDER-DOPED La2-xSrxCuO4-y BY POLARIZED EXAFS
Authors: GARG K. B. , SANCHEZ C. , GARCIA J. , BLASCO J. , SINGHAL R. K. , DALELA S. , SAINI N. L. 
Published: July 2002

Temperature dependence of local structure of the CuO 2 plane has been studied by in plane polarized (E//ab) Cu K-edge extended X-ray absorption fine structure (EXAFS) experiments on an under-doped single crystal of superconducting La1.87Sr0.13CuO 4-y system with T c =32 K . The temperature dependence of the Debye–Waller factors for the Cu-O and Cu-La/Sr pairs are determined. We find that the motion of Cu and O atoms in the Cu-O bond is partially correlated at higher temperatures, going over to an uncorrelated motion at lower temperatures. The results are discussed in terms of the local lattice instabilities and stripes as reported in other systems.
A NEURAL NETWORK-BASED IMAGE RETRIEVAL USING NONLINEAR COMBINATION OF HETEROGENEOUS FEATURES
Authors: LEE HYOUNG K. , YOO SUK I. 
Published: July 2002

In content-based image retrieval (CBIR), content of an image can be expressed in terms of different features such as color, texture, shape, or text annotations. Retrieval based on these features can be various by the way how to combine the feature values. Most of the existing approaches assume a linear relationship between different features, and the usefulness of such systems was limited due to the difficulty in representing high-level concepts using low-level features. In this paper, we introduce Neural Network-based Flexible Image Retrieval (NNFIR) system, a human-computer interaction approach to CBIR using Radial Basis Function (RBF) network to combine the values of the heterogeneous features. By using the RBF network, this approach determines nonlinear relationship between features so that more accurate similarity comparison between images can be supported. The experimental results show that the proposed approach has the superior retrieval performance than the existing linear combining method, the rank-based method and the BackPropagation-based method. Although the proposed retrieval model is for CBIR, it can be easily expanded to handle other media types, such as video and audio.
The future of programming
Authors: Wasserman Anthony I. , Gutz Steven 
Published: July 2002

The nature of programming is changing. These changes will accelerate as improved software development practices and more sophisticated development tools and environments are produced. This paper surveys the most likely changes in the programming task and in the nature of software over the short term, the medium term, and the long term.
In the short term, the focus is on gains in programmer productivity through improved tools and integrated development environments. In the medium term, programmers will be able to take advantage of libraries of software components and to make use of packages that generate programs automatically for certain kinds of common systems. Over the longer term, the nature of programming will change even more significantly as programmers become able to describe desired functions in a nonprocedural way, perhaps through a set of rules or formal specification languages. As these changes occur, the job of the application programmer will become increasingly analysis-oriented and software developers will be able to attack a large number of application areas which could not previously be addressed effectively.
A note on computing approximations to the exponential function
Authors: Cody W. J. , Ralston Anthony 
Published: July 2002

Two methods are discussed which result in near minimax rational approximations to the exponential function and at the same time retain the desirable property that the approximation for negative values of the argument is the reciprocal of the approximation for corresponding positive values. These methods lead to approximations which are much superior to the commonly used convergents of the Gaussian continued fraction for the exponential. Coefficients and errors are given for the intervals [-1/2 ln 2, 1/2 ln 2] and [-ln 2, ln 2].
Two methods are discussed which result in near minimax rational approximations to the exponential function and at the same time retain the desirable property that the approximation for negative values of the argument is the reciprocal of the approximation for corresponding positive values. These methods lead to approximations which are much superior to the commonly used convergents of the Gaussian continued fraction for the exponential. Coefficients and errors are given for the intervals [-1/2 ln 2, 1/2 ln 2] and [-ln 2, ln 2].
Computational Linguistics: Graphical input/output of nonstandard characters
Authors: Hayashi Hideyuki , Duncan Sheila , Kuno Susumu 
Published: July 2002

A system developed at Harvard for graphically inputting and outputting nonstandard characters on a computer is printed. In principle, the system can deal with any orthography, although at present it is limited to 4000 Chinese characters and some mathematical symbols. New characters can be added to the repertoire of the system by graphical input on a display scope. Text inputting is accomplished via a display scope or a Rand Tablet.
The organization and operation of the current system are described, and a discussion of the relative merits of such a system is given. Illustrations of the computer input and output of Chinese characters are included.
Multilevel operating systems
Authors: Orchard-Hays William 
Published: July 2002

The basic software for all newer computers is built on the well-established need for standard operating systems. This implies that all applications—no matter how large, complex or time consuming—must operate under (or, more precisely, on top of) the standard system.
Large applications require supervisory monitors which handle problems similar to those of the operating systems, but at a different level. Sometimes, still a third or even a fourth such level is required or desirable. This leads naturally to the concept of multilevel systems—similar vertically, but different horizontally. Proper division of responsibility between levels leads to greater efficiency and less logical complexity, while actually enhancing capability.
The self-judgment method of curve fitting
Authors: de Maine P. A. D. 
Published: July 2002

A computer-oriented method for processing and communicating numerical data is described. The Instrument Reliability Factors (IRF), which exactly define the limits of reliability of each measured item of information, are used to compute the Maximum Permitted Error (MPE) associated with each value of each ordinate. The Self-Judgment Principle (SJP) is used to discard wrong information and to compute mean values of the parameters and their MPE's in terms of the IRF. Data compatibility tests with any number of different equations can be made quickly. Otherwise intractable problems are easily solved, and the design of many experiments is greatly simplified.
The computational and mathematical techniques used to reduce bias in the SJP are discussed. Inadequacies in the statistical and graphical methods of curve fitting are noted.
Nutrition, Genetics, and Risks of Cancer
Authors: Rock Cheryl L. , Lampe Johanna W. , Patterson Ruth E. 
Published: July 2002

▪ Abstract  Dietary patterns, nutrients, and other constituents of food are major components of the environmental influences that contribute to risk for cancer, and the study of interactions between nutritional and genetic factors is a new and important area of research. This review describes the concepts and principles underlying this area of study and types of relationships between nutritional and genetic factors, and it provides examples of specific diet-gene interactions that are of current interest, with an emphasis on implications for cancer prevention and public health. Polymorphisms exist in the genes for the activating and conjugating metabolizing enzymes, and the induction of metabolizing enzyme activity by nutritional factors may result in either the activation of a carcinogen or the detoxification of a reactive intermediate metabolite. The relationship between the methylenetetrahydrofolate reductase gene and dietary folate is an example of a diet-gene interaction that involves a polymorphism in a vitamin metabolism gene, and the presence of the variant appears to influence both risk for cancer and folate requirements. Diet-gene interactions likely contribute considerably to the observed inter-individual variations in cancer risk in response to exposures to the nutritional factors that have the potential to promote or protect against cancer. Insights into mechanisms by which nutritional factors affect the process of carcinogenesis are provided by knowledge of the targeted gene function and enzyme activity. Increased knowledge in this area will allow a more refined approach to reducing risk for cancer, with diet interventions targeted toward individuals and subgroups that are genetically susceptible and responsive to the effects of nutritional factors. Investigating the cellular and molecular pathogenesis of cancer is an established and important area of basic science research. Within the past several years, the capability of examining biomarkers of various genetic factors in the development and progression of chronic diseases, such as cancers, has enabled researchers to study these factors in clinical and community-based populations, in which environmental factors can also be measured or even manipulated. Dietary patterns and the nutrients and other co nstituents of food are a major component of the environmental influen ces that appear to contribute to disease risk, and the study of interactions between nutritional and genetic factors is a new and important area of research. This review describes the concepts and principles underlying this area of study, describes types of relationships between nutritional and genetic factors, provides examples of specific diet-gene interactions that are of current interest, and comments on implications for cancer prevention and public health.
Using Suffix Arrays to Compute Term Frequency and Document Frequency for All Substrings in a Corpus
Authors: Yamamoto Mikio , Church Kenneth W. 
Published: July 2002

Bigrams and trigrams are commonly used in statistical natural language processing; this paper will describe techniques for working with much longer n-grams. Suffix arrays (Manber and Myers 1990) were first introduced to compute the frequency and location of a substring (n-gram) in a sequence (corpus) of length N. To compute frequencies over all N(N+1)/2 substrings in a corpus, the substrings are grouped into a manageable number of equivalence classes. In this way, a prohibitive computation over substrings is reduced to a manageable computation over classes. This paper presents both the algorithms and the code that were used to compute term frequency (tf) and document frequency (df) for all n-grams in two large corpora, an English corpus of 50 million words of Wall Street Journal and a Japanese corpus of 216 million characters of Mainichi Shimbun. The second half of the paper uses these frequencies to find “interesting” substrings. Lexicographers have been interested in n-grams with high mutual information (MI) where the joint term frequency is higher than what would be expected by chance, assuming that the parts of the n-gram combine independently. Residual inverse document frequency (RIDF) compares document frequency to another model of chance where terms with a particular term frequency are distributed randomly throughout the collection. MI tends to pick out phrases with noncompositional semantics (which often violate the independence assumption) whereas RIDF tends to highlight technical terminology, names, and good keywords for information retrieval (which tend to exhibit nonrandom distributions over documents). The combination of both MI and RIDF is better than either by itself in a Japanese word extraction task.
Contrasting Cortical and Subcortical Activations Produced by Attentional-Set Shifting and Reversal Learning in Humans
Authors: Rogers R. D. , Andrews T. C. , Grasby P. M. , Brooks D. J. , Robbins T. W. 
Published: July 2002

Abstract
Much evidence suggests that lesions of the prefrontal cortex (PFC) produce marked impairments in the ability of subjects to shift cognitive set, as exemplified by performance of the Wisconsin Card Sorting Test (WCST). However, studies with humans and experimental primates have suggested that damage to different regions of PFC induce dissociable impairments in two forms of shift learning implicit in the WCST (that is, extradimensional (ED) shift learning and reversal shift learning), with similar deficits also being apparent after damage to basal ganglia structures, especially the caudate nucleus. In this study, we used the same visual discrimination learning paradigm over multidimensional stimuli, and the H2 15O positron emission tomography (PET) technique, to examine regional cerebral blood flow (rCBF) changes associated with these subcomponent processes of the WCST. In three conditions, subjects were scanned while acquiring visual discriminations involving either (i) the same stimulus dimension as preceding discriminations (intradimensional (ID) shifts); (ii) different stimulus dimensions from previous discriminations (ED shifts) or (iii) reversed stimulus-reward contingencies (reversal shifts). Additionally, subjects were scanned while responding to already learnt discriminations (‘performance baseline’). ED shift learning, relative to ID shift learning, produced activations in prefrontal regions, including, left anterior PFC and right dorsolateral PFC (BA 10 and 9/46). By contrast, reversal learning, relative to ID shift learning, produced activations of the left caudate nucleus. Additionally, compared to reversal and ID shift learning, ED shift learning was associated with relative deactivations in occipito-temporal pathways (for example, BA 17 and 37). These results confirm that, in the context of visual discrimination learning over multidimensional stimuli, the control of an acquired attentional bias or 'set', and the control of previously acquired stimulus-reinforcement associations, activate distinct cortical and subcortical neural stations. Moreover, we propose that the PFC may contribute to the control of attentional-set by modulating attentional processes mediated by occipito-temporal pathways.
Hemispheric Asymmetries for Whole-Based and Part-Based Face Processing in the Human Fusiform Gyrus
Authors: Rossion Bruno , Dricot Laurence , Devolder Anne , Bodart Jean-Michel , Crommelinck Marc , Gelder Beatrice de , Zoontjes Richard 
Published: July 2002

Abstract
Behavioral studies indicate a right hemisphere advantage for processing a face as a whole and a left hemisphere superiority for processing based on face features. The present PET study identifies the anatomical localization of these effects in well-defined regions of the middle fusiform gyri of both hemispheres. The right middle fusiform gyrus, previously described as a face-specific region, was found to be more activated when matching whole faces than face parts whereas this pattern of activity was reversed in the left homologous region. These lateralized differences appeared to be specific to faces since control objects processed either as wholes or parts did not induce any change of activity within these regions. This double dissociation between two modes of face processing brings new evidence regarding the lateralized localization of face individualization mechanisms in the human brain.
A Double Dissociation in the Affective Modulation of Startle in Humans: Effects of Unilateral Temporal Lobectomy
Authors: Funayama E. Sumie , Grillon Christian , Davis Michael , Phelps Elizabeth A. 
Published: July 2002

Abstract
In the present study we report a double dissociation between right and left medial temporal lobe damage in the modulation of fear responses to different types of stimuli. We found that right unilateral temporal lobectomy (RTL) patients, in contrast to control subjects and left temporal lobectomy (LTL) patients, failed to show potentiated startle while viewing negative pictures. However, the opposite pattern of impairment was observed during a stimulus that patients had been told signaled the possibility of shock. Control subjects and RTL patients showed potentiated startle while LTL patients failed to show potentiated startle. We hypothesize that the right medial temporal lobe modulates fear responses while viewing emotional pictures, which involves exposure to (emotional) visual information and is consistent with the emotional processing traditionally ascribed to the right hemisphere. In contrast, the left medial temporal lobe modulates fear responses when those responses are the result of a linguistic/cognitive representation acquired through language, which, like other verbally mediated material, generally involves the left hemisphere. Additional evidence from case studies suggests that, within the medial temporal lobe, the amygdala is responsible for this modulation.