38 research outputs found

    Spectroscopic on-line monitoring and stopped-flow kinetic analysis of dye degradation by laccase/mediator systems

    Get PDF
    The laccase catalyzed transformation of the acid dye Indigo Carmine (CI Acid Blue 74) was studied using various redox mediators: violuric acid (VIO), 2,2,6,6-tetramethyl-1-piperidinyloxyl (TEMPO), 1-hydroxybenzotriazole (HOBT), and 2,2-azinobis-(3-ethylbenzothiazoline-6-disulfonic acid diammonium salt (ABTS). Inline UV/Vis and IR spectroscopy was employed to monitor the decolorization in real-time during batch decolorization. ABTS was the most effective mediator follwed by TEMPO. Stopped flow kinetics was employed to study the initial phase of dye degradation in more detail. While the batch decolorization experiments suggested zero-order rate laws for dye transformation at an early stage, the more accurate stopped-flow kinetic experiments revealed that the rate laws for the initial phase were actually more complicated. Different pH optima for dye decolorization were found for the laccase catalyzed reaction (pH 3.5) and for the oxidation brought about by the isolated ABTS radical cation (pH 6.7)

    Pragmatic Ontology Evolution: Reconciling User Requirements and Application Performance

    Get PDF
    Increasingly, organizations are adopting ontologies to describe their large catalogues of items. These ontologies need to evolve regularly in response to changes in the domain and the emergence of new requirements. An important step of this process is the selection of candidate concepts to include in the new version of the ontology. This operation needs to take into account a variety of factors and in particular reconcile user requirements and application performance. Current ontology evolution methods focus either on ranking concepts according to their relevance or on preserving compatibility with existing applications. However, they do not take in consideration the impact of the ontology evolution process on the performance of computational tasks – e.g., in this work we focus on instance tagging, similarity computation, generation of recommendations, and data clustering. In this paper, we propose the Pragmatic Ontology Evolution (POE) framework, a novel approach for selecting from a group of candidates a set of concepts able to produce a new version of a given ontology that i) is consistent with the a set of user requirements (e.g., max number of concepts in the ontology), ii) is parametrised with respect to a number of dimensions (e.g., topological considerations), and iii) effectively supports relevant computational tasks. Our approach also supports users in navigating the space of possible solutions by showing how certain choices, such as limiting the number of concepts or privileging trendy concepts rather than historical ones, would reflect on the application performance. An evaluation of POE on the real-world scenario of the evolving Springer Nature taxonomy for editorial classification yielded excellent results, demonstrating a significant improvement over alternative approaches

    Shatavari supplementation in postmenopausal women improves handgrip strength and increases vastus lateralis myosin regulatory light chain phosphorylation but does not alter markers of bone turnover

    Get PDF
    Abstract: Shatavari has long been used as an Ayurvedic herb for women’s health, but empirical evidence for its effectiveness has been lacking. Shatavari contains phytoestrogenic compounds that bind to the estradiol receptor. Postmenopausal estradiol deficiency contributes to sarcopenia and osteoporosis. In a randomised double-blind trial, 20 postmenopausal women (68.5 ± 6 years) in-gested either placebo (N = 10) or shatavari (N = 10; 1000 mg/d, equivalent to 26,500 mg/d fresh weight shatavari) for 6 weeks. Handgrip and knee extensor strength were measured at baseline and at 6 weeks. Vastus lateralis (VL) biopsy samples were obtained. Data are presented as difference scores (Week 6 – baseline, median ± interquartile range). Handgrip, (but not knee extensor) strength was improved by shatavari supplementation (shatavari +0.7 ± 1.1 kg, placebo -0.4 ± 1.3 kg; p=0.04). Myosin regulatory light chain phosphorylation, a known marker of improved myosin contractile function, was increased in VL following shatavari supplementation (immunoblotting; placebo -0.08 ± 0.5 a.u. shatavari +0.3 ± 1 arbitrary units (a.u.); p = 0.03). Shatavari increased phosphorylation of Aktser473 (Aktser473 (placebo -0.6 ± 0.6 a.u. shatavari +0.2 ± 1.3 a.u; p = 0.03) in VL. Shatavari supplementation did not alter plasma markers of bone turnover (P1NP, β-CTX) and stimulation of human osteoblasts with pooled sera (N = 8 per condition) from placebo and shatavari supplementation conditions did not alter cytokine or metabolic markers of osteoblast activity. Shatavari may improve muscle function and contractility via myosin conformational change and warrants further investigation in larger and more diverse cohorts of its utility in conserving and enhancing musculoskeletal functio

    Creating and Using Organisational Semantic Webs in Large Networked Organisations

    Full text link
    Abstract. Modern knowledge management is based on the orchestration of dynamic communities that acquire and share knowledge according to customized schemas. However, while independence of ontological views is favoured, these communities must also be able to share their knowledge with the rest of the organization. In this paper we introduce K-Forms and K-Search, a suite of Semantic Web tools for supporting distributed and networked knowledge acquisition, capturing, retrieval and sharing. They enable communities of users to define their own domain views in an intuitive way (automatically translated into formal ontologies) and capture and share knowledge according to them. The tools favour reuse of existing ontologies; reuse creates as side effect a network of (partially) interconnected ontologies that form the basis for knowledge exchange among communities. The suite is under release to support knowledge capture, retrieval and sharing in a large jet engine company

    Benchmarking Ontologies: Bigger or Better?

    Get PDF
    A scientific ontology is a formal representation of knowledge within a domain, typically including central concepts, their properties, and relations. With the rise of computers and high-throughput data collection, ontologies have become essential to data mining and sharing across communities in the biomedical sciences. Powerful approaches exist for testing the internal consistency of an ontology, but not for assessing the fidelity of its domain representation. We introduce a family of metrics that describe the breadth and depth with which an ontology represents its knowledge domain. We then test these metrics using (1) four of the most common medical ontologies with respect to a corpus of medical documents and (2) seven of the most popular English thesauri with respect to three corpora that sample language from medicine, news, and novels. Here we show that our approach captures the quality of ontological representation and guides efforts to narrow the breach between ontology and collective discourse within a domain. Our results also demonstrate key features of medical ontologies, English thesauri, and discourse from different domains. Medical ontologies have a small intersection, as do English thesauri. Moreover, dialects characteristic of distinct domains vary strikingly as many of the same words are used quite differently in medicine, news, and novels. As ontologies are intended to mirror the state of knowledge, our methods to tighten the fit between ontology and domain will increase their relevance for new areas of biomedical science and improve the accuracy and power of inferences computed across them

    61st Illinois Fire College Brochure

    Get PDF
    This brochure, produced in 1985, describes the information and courses offered during the 61st Illinois Fire College conducted by the Illinois Fire Service Institute.Ope

    Single color networks: OFDM-based visible light broadcasting

    No full text
    Due to copyright restrictions, the access to the full text of this article is only available via subscription.In this study, we investigate the performance of optical orthogonal frequency division multiplexing (O-OFDM) based visible light broadcasting. Although indoor spaces usually have more than one light source, most of the existing works on visible light communication (VLC) in the current literature consider point-to-point communication and few efforts have been made on the scenarios with multiple transmitters. In this work, we consider a broadcasting scenario in which multiple transmitters (light sources) simultaneously emit the same information. Since this network structure constitutes a similar network topology to single frequency networks (SFN) in OFDM-based digital audio/video broadcasting, we coin the term “single color network (SCN)” to refer these visible light broadcasting systems. Based on extensive Monte Carlo simulations, we present the error rate performance of SCNs as well as discuss their lighting performance.Nazarbayev Universit

    SWAP: Ontology-based Knowledge Management with Peer-to-Peer Technology

    Get PDF
    Introduction In today's knowledge-based economy, the competitiveness of enterprizes and the quality of work life are directly tied to the ability to effectively create and share knowledge both within and across organizations. Many enterprizes have therefore spent huge amounts of money to implement centralized knowledge management systems (KMSs). Ontologies have shown to be the right answer to knowledge structuring and modelling by providing a formal conceptualization of a particular domain that is shared by a group of people in an organization [OL98]. However, KMSs based on centralized ontologies need a long development phase and are difficult to maintain. [BBT02] suggest a distributed approach to Knowledge Management which better fits the true situation in organizations and the processes people are used to. From a technological point of view peer-to-peer (P2P) solutions are particularly well suited, because they make it possible for different participants (organizations, individua
    corecore