4,111 research outputs found

    A Logic Programming Elucidation of ODA - Document Descriptions and Processes

    Get PDF
    We are pursuing a programme of research in document representation. The principal aim of this research is to develop a document description language that has a precise formal semantics, that is fully expressive of the constructs typical of traditional (procedural) document description languages, that is constraint-based, and that cleanly separates specifications of form and content. The research is currently in the first of three envisioned three phases. In the first phase we are formalising the Office Document Architecture (ODA) by faithfully translating ODA document descriptions into logic programmes. The transition utilizes highly restricted forms of Prolog programmes.1 In the second phase we will explore various enhancements of ODA\u27s expressive power that are immediately apparent upon freeing the translation from having to adhere to the initial restrictive conventions. Finally, we will explore and articulate a constraint logic programming language having “built-in constructs for expressing both primitive and composite document description concepts. In the present essay we sketch our translation (into a DCG framework) of ODA document descriptions and (layout) processes. As it turns out the resulting translation is closely related to so called functional attribute grammars [4]. Indeed, we hope eventually to exploit that relationship to enable efficient interpretation of the resulting translation. For now, however, we hope to convince our readers that (definite clause) grammars are a natural and powerful generalisation of the ODA framework, and that the ODA layout process can be specified entirely by declarative means by appealing to properties of the grammars in question

    A Logic Grammar Foundation for Document Representation and Document Layout

    Get PDF
    We present a powerful grammar-based paradigm for electronic document markup: coordinated definite clause translation grammars. This markup is of a declarative character, being, in effect, a collection of constraints on the logical and physical structure of documents. To the best of our knowledge, coordinated grammars and their parsers can accommodate all of the descriptive and layout processing functionality enjoyed by extant electronic markup languages. We describe an operational prototype that demonstrates the feasibility of a syntax-directed basis for formalizing and realizing document layout

    A Reconstruction of Context-Dependent Document Processing In SGML

    Get PDF
    SGML achieves a certain degree of context-dependent document processing through attributes and linking. These mechanisms are deficient in several respects. To address these deficiencies we propose augmenting SGML\u27s LINK and ATTLISTconstructs with two new mechanisms, coordination and (rule-based) attribution. The latter can be used to specify the result of context-dependent processing in a uniform fashion while considerably increasing SGML\u27s expressive power. We illustrate this enhanced power by sketching a specification of (the result of) document layout that can be encoded in SGML augmented with coordination and attribution

    Monotone Logic Programming

    Get PDF
    We propose a notion of an abstract logic. Based on this notion, we define abstract logic programs to be sets of sentences of an abstract logic. When these abstract logics possess certain logical properties (some properties considered are compactness, finitariness, and monotone consequence relations) we show how to develop a fixed-point, model-state-theoretic and proof theoretic semantics for such programs. The work of Melvin Fitting on developing a generalized semantics for multivalued logic programming is extended here to arbitrary abstract logics. We present examples to show how our semantics is robust enough to be applicable to various non-classical logics like temporal logic and multivalued logics, as well as to extensions of classical logic programming such as disjunctive logic programming. We also show how some aspects of the declarative semantics of distributed logic programming, particularly work of Ramanujam, can be incorporated into our framework

    Thermal partition function of photons and gravitons in a Rindler wedge

    Get PDF
    The thermal partition function of photons in any covariant gauge and gravitons in the harmonic gauge, propagating in a Rindler wedge, are computed using a local ζ\zeta-function regularization approach. The correct Planckian leading order temperature dependence T4T^4 is obtained in both cases. For the photons, the existence of a surface term giving a negative contribution to the entropy is confirmed, as earlier obtained by Kabat, but this term is shown to be gauge dependent in the four-dimensional case and, therefore is discarded. It is argued that similar terms could appear dealing with any integer spin s1s\geq 1 in the massless case and in more general manifolds. Our conjecture is checked in the case of a graviton in the harmonic gauge, where different surface terms also appear, and physically consistent results arise dropping these terms. The results are discussed in relation to the quantum corrections to the black hole entropy.Comment: 29 pages, RevTeX, no figures. Minor errors corrected and a few comments changed since first submission. To be published on Phys.Rev.

    Endoscopic Saphenous harvesting with an Open CO2 System (ESOS) trial for coronary artery bypass grafting surgery: study protocol for a randomized controlled trial

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In coronary artery bypass grafting surgery, arterial conduits are preferred because of more favourable long-term patency and outcome. Anyway <it>the greater saphenous vein </it>continues to be the most commonly used bypass conduit. <it>Minimally invasive endoscopic saphenous vein harvesting </it>is increasingly being investigated in order to reduce the morbidity associated with conventional open vein harvesting, includes postoperative leg wound complications, pain and patient satisfaction. However, to date the short and the long-term benefits of the endoscopic technique remain controversial. This study provides an interesting opportunity to address this gap in the literature.</p> <p>Methods/Design</p> <p><b>Endoscopic Saphenous harvesting with an Open CO<sub>2 </sub>System </b>trial includes two parallel vein harvesting arms in coronary artery bypass grafting surgery. It is an interventional, single centre, prospective, randomized, safety/efficacy, cost/effectiveness study, in adult patients with elective planned and first isolated coronary artery disease. A simple size of 100 patients for each arm will be required to achieve 80% statistical power, with a significant level of 0.05, for detecting most of the formulated hypotheses. A six-weeks leg wound complications rate was assumed to be 20% in the conventional arm and less of 4% in the endoscopic arm. Previously quoted studies suggest a first-year vein-graft failure rate of about 20% with an annual occlusion rate of 1% to 2% in the first six years, with practically no difference between the endoscopic and conventional approaches. Similarly, the results on event-free survival rates for the two arms have barely a 2-3% gap. Assuming a 10% drop-out rate and a 5% cross-over rate, the goal is to enrol 230 patients from a single Italian cardiac surgery centre.</p> <p>Discussion</p> <p>The goal of this prospective randomized trial is to compare and to test improvement in wound healing, quality of life, safety/efficacy, cost-effectiveness, short and long-term outcomes and vein-graft patency after endoscopic open CO<sub>2 </sub>harvesting system versus conventional vein harvesting.</p> <p>The expected results are of high clinical relevance and will show the safety/efficacy or non-inferiority of one treatment approach in terms of vein harvesting for coronary artery bypass grafting surgery.</p> <p>Trial registration</p> <p>www.clinicalTrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT01121341">NCT01121341</a>.</p

    Influence of nutrients and currents on the genomic composition of microbes across an upwelling mosaic

    Get PDF
    Metagenomic data sets were generated from samples collected along a coastal to open ocean transect between Southern California Bight and California Current waters during a seasonal upwelling event, providing an opportunity to examine the impact of episodic pulses of cold nutrient-rich water into surface ocean microbial communities. The data set consists of ∼5.8 million predicted proteins across seven sites, from three different size classes: 0.1–0.8, 0.8–3.0 and 3.0–200.0 μm. Taxonomic and metabolic analyses suggest that sequences from the 0.1–0.8 μm size class correlated with their position along the upwelling mosaic. However, taxonomic profiles of bacteria from the larger size classes (0.8–200 μm) were less constrained by habitat and characterized by an increase in Cyanobacteria, Bacteroidetes, Flavobacteria and double-stranded DNA viral sequences. Functional annotation of transmembrane proteins indicate that sites comprised of organisms with small genomes have an enrichment of transporters with substrate specificities for amino acids, iron and cadmium, whereas organisms with larger genomes have a higher percentage of transporters for ammonium and potassium. Eukaryotic-type glutamine synthetase (GS) II proteins were identified and taxonomically classified as viral, most closely related to the GSII in Mimivirus, suggesting that marine Mimivirus-like particles may have played a role in the transfer of GSII gene functions. Additionally, a Planctomycete bloom was sampled from one upwelling site providing a rare opportunity to assess the genomic composition of a marine Planctomycete population. The significant correlations observed between genomic properties, community structure and nutrient availability provide insights into habitat-driven dynamics among oligotrophic versus upwelled marine waters adjoining each other spatially

    Effect of maternal Schistosoma mansoni infection and praziquantel treatment during pregnancy on Schistosoma mansoni infection and immune responsiveness among offspring at age five years.

    Get PDF
    INTRODUCTION: Offspring of Schistosoma mansoni-infected women in schistosomiasis-endemic areas may be sensitised in-utero. This may influence their immune responsiveness to schistosome infection and schistosomiasis-associated morbidity. Effects of praziquantel treatment of S. mansoni during pregnancy on risk of S. mansoni infection among offspring, and on their immune responsiveness when they become exposed to S. mansoni, are unknown. Here we examined effects of praziquantel treatment of S. mansoni during pregnancy on prevalence of S. mansoni and immune responsiveness among offspring at age five years. METHODS: In a trial in Uganda (ISRCTN32849447, http://www.controlled-trials.com/ISRCTN32849447/elliott), offspring of women treated with praziquantel or placebo during pregnancy were examined for S. mansoni infection and for cytokine and antibody responses to SWA and SEA, as well as for T cell expression of FoxP3, at age five years. RESULTS: Of the 1343 children examined, 32 (2.4%) had S. mansoni infection at age five years based on a single stool sample. Infection prevalence did not differ between children of treated or untreated mothers. Cytokine (IFNγ, IL-5, IL-10 and IL-13) and antibody (IgG1, Ig4 and IgE) responses to SWA and SEA, and FoxP3 expression, were higher among infected than uninfected children. Praziquantel treatment of S. mansoni during pregnancy had no effect on immune responses, with the exception of IL-10 responses to SWA, which was higher in offspring of women that received praziquantel during pregnancy than those who did not. CONCLUSION: We found no evidence that maternal S. mansoni infection and its treatment during pregnancy influence prevalence and intensity of S. mansoni infection or effector immune response to S. mansoni infection among offspring at age five years, but the observed effects on IL-10 responses to SWA suggest that maternal S. mansoni and its treatment during pregnancy may affect immunoregulatory responsiveness in childhood schistosomiasis. This might have implications for pathogenesis of the disease
    corecore