8,117 research outputs found

    Synthesis and conformational analysis of leptocarpin derivatives. Influence of modification of the oxirane ringon leptocarpin's cytotoxic activity.

    Get PDF
    Indexación: ScieloABSTRACT The reaction in acidconditions of Leptocarpin 1, a compound with antitumor activity, formed two new isomeric products, 8b-angeloyl-1b,3b-dihydroxy-4,10-dimethyl,-D11(13) methylen-4Z,9Z-dieneheliangol-6,12-olide 2 and 8b-angeloyl-1b,3b-dihydroxy-4-methyl-D11(13),D11(14)-dimethylen-4Z-eneheliangol-6,12-olide 3, whose structures reported in this study were established by spectroscopy (1H-NMR, 13C-NMR, MS and IR) and confirmedthrough ROESY experiments and theoretical studies by molecular mechanics. The in vitro cytotoxicity of these isomeric compounds was less active than leptocarpin, showing the importance of the oxirane ring in the biological activity. Cytotoxic activity was measured in six cancer cell lines. Keywords: Conformational analysis; Heliangolide; Sesquiterpene lactones; Cytotoxicity

    Sparse Graphical Designs via Linear Programming

    Full text link
    Graphical designs are a framework for sampling and numerical integration of functions on graphs. In this note, we introduce a method to address the trade-off between graphical design sparsity and accuracy. We show how to obtain sparse graphical designs via linear programming and design objective functions that aim to maximize their accuracy. We showcase our approach using yellow taxicab data from New York City

    Sustainable Irrigation Management of Ornamental Cordyline Fruticosa “Red Edge” Plants with Saline Water

    Get PDF
    The aim of this work was to analyze the influence of the salinity of the nutrient solution on the transpiration and growth of Cordyline fruticosa var. “Red Edge” plants. A specific irrigation management model was calibrated with the experimental data. An experiment was performed with four treatments. These treatments consisted of the application of four nutrient solutions with different electrical conductivity (ECw) levels ranging from 1.5 dS m−1 (control treatment) to 4.5 dS m−1. The results showed that day-time transpiration decreases when salt concentration in the nutrient solution increases. The transpiration of the plant in the control treatment was modelled by applying a combination method while the effect of the salinity of the nutrient solution was modelled by deriving a saline stress coefficient from the experimental data. The results showed that significant reductions in plant transpiration were observed for increasing values of ECw. The crop development and yield were also affected by the increasing salinity of the nutrient solution. A relationship between the ECw and the relative crop yield was derived

    OCL2Trigger: Deriving active mechanisms for relational databases using Model-Driven Architecture

    Get PDF
    16 pages, 10 figures.-- Issue title: "Best papers from the 2007 Australian Software Engineering Conference (ASWEC 2007), Melbourne, Australia, April 10-13, 2007, Australian Software Engineering Conference 2007".Transforming integrity constraints into active rules or triggers for verifying database consistency produces a serious and complex problem related to real time behaviour that must be considered for any implementation. Our main contribution to this work is to provide a complete approach for deriving the active mechanisms for Relational Databases from the specification of the integrity constraints by using OCL. This approach is designed in accordance with the MDA approach which consists of transforming the specified OCL clauses into a class diagram into SQL:2003 standard triggers, then transforming the standard triggers into target DBMS triggers. We believe that developing triggers and plugging them into a given model is insufficient because the behaviour of such triggers is invisible to the developers, and therefore not controllable. For this reason, a DBMS trigger verification model is used in our approach, in order to ensure the termination of trigger execution. Our approach is implemented as an add-in tool in Rational Rose called OCL2Trigger.This work is part of the "Software Process Management Platform: Modelling, reuse and measurement" TIN2004/07083 project.Publicad

    Applying a Fuzzy Approach to Relaxing Cardinality Constraints

    Get PDF
    9 pages, 3 figures.-- Contributed to: 15th International Conference on Database and Expert Systems Applications (DEXA 2004, Zaragoza, Spain, Aug 30 - Sep 3, 2004).In database applications the verification of cardinality constraints is a serious and complex problem that appears when the modifications operations are performed in a large cascade. Many efforts have been devoted to solve this problem, but some solutions lead to other problems such as the complex execution model or an impact on the database performance. In this paper a method to reducing and simplifying the complex verification of cardinality constraints by relaxing these constraints using fuzzy concepts is proposed.Publicad

    Platooning of connected automated vehicles on freeways: a bird’s eye view

    Get PDF
    A platoon of connected automated vehicles (CAVs) is defined as a group of CAVs that exchange information, so that they can drive in a coordinated way, allowing very small spacings and, still, travelling safely at relatively high speeds. The concept of vehicle platooning is not new. Scientific articles on platooning have been published since the 1970s, and the first large-scale pilot test on vehicle platooning was carried out in the mid 1990s in California. By 1992, the first vehicle platooning experiments were successfully concluded, and the four-vehicle platoon capability was demonstrated for visitors on the I-15 HOV lanes in San Diego in 1994. The main purpose of these early research works was to improve traffic efficiency and reduce vehicle consumption, as well as to develop the existing technology, which represented a strong limitation at the time. Precisely, the development of new technologies and communications in the last decade has given a new impetus to the research on vehicle platooning on freeways, as one of the most promising forms of cooperation among CAVs. These recent studies have extended the analysis beyond traffic efficiency, including safety, sustainability, business productivity, among other objectives. In this context, today, there are many scientific publications on vehicle platooning with different purposes, scopes, scenarios, and based on a wide diversity of vehicles and technologies (i.e. regular or segregated lanes, cars or trucks, vehicles with different SAE levels, etc.). In order to organize and consolidate the existing knowledge on the field, a comprehensive and systematic review must be performed. The present work represents a first approach to this ambitious objective. First, platooning is conceptualized in order to facilitate its analysis and comparison among studies. Second, key publications on platooning are analyzed to determine the most significant impacts that can be expected from its implementation. Finally, some important research gaps and disparate findings on the topic are identified.This research has been partially funded by the Spanish Ministry of Economy, Industry and Competitiveness, within the National Program for Research Aimed at the Challenges of Society (grant ref. PID2019-105331RB-I00).Peer ReviewedPostprint (published version

    Plugging active mechanisms to control dynamic aspects derived from the Multiplicity Constraint in UML

    Get PDF
    8 pages, 5 figures.-- Contributed to: 7th International Conference on the Unified Modeling Language (UML'2004, Lisbon, Portugal, Oct 11-15, 2004).Multiple efforts have been devoted to face the problem of database modelling. One of them is the automatization of database design process using CASE tools. Frequently, these tools do not completely support all phases of database analysis and the design methodology that they propose. Therefore, we propose to incorporate new features to these tools enhancing them and solving some of the modelling problems. In this paper we present an add-in module that aims to generate triggers for preserving the multiplicity constraints of a conceptual scheme in the transformation to a relational scheme. The module is integrated into the RATIONAL ROSE case tool.Publicad

    Combining Wikipedia and Newswire Texts for Question Answering in Spanish

    Get PDF
    4 pages, 1 figure.-- Contributed to: Advances in Multilingual and Multimodal Information Retrieval: 8th Workshop of the Cross-Language Evaluation Forum (CLEF 2007, Budapest, Hungary, Sep 19-21, 2007).This paper describes the adaptations of the MIRACLE group QA system in order to participate in the Spanish monolingual question answering task at QA@CLEF 2007. A system, initially developed for the EFE collection, was reused for Wikipedia. Answers from both collections were combined using temporal information extracted from questions and collections. Reusing the EFE subsystem has proven not feasible, and questions with answers only in Wikipedia have obtained low accuracy. Besides, a co-reference module based on heuristics was introduced for processing topic-related questions. This module achieves good coverage in different situations but it is hindered by the moderate accuracy of the base system and the chaining of incorrect answers.This work has been partially supported by the Regional Government of Madrid under the Research Network MAVIR (S-0505/TIC-0267) and projects by the Spanish Ministry of Education and Science (TIN2004/07083,TIN2004-07588-C03-02,TIN2007-67407-C03-01).Publicad

    Factores de riesgo cardiovascular, control de la dislipemia y uso de hipolipemiantes en el Área Sanitaria II de Asturias

    Get PDF
    224 p.Existe un perfil de factores de riesgo distinto según la presentación clínica de la enfermedad cardiovascular. Los pacientes con infarto agudo de miocardio presentan mayor prevalencia de dislipemia, tabaquismo y una edad menor, mientras que el ictus isquémico aerotrombótico se asocia más, aunque no de forma significativa, con la hipertensión y el sexo femenino. Las mujeres tienen un perfil de riesgo cardiovascular más adverso que los hombres, con mayor prevalencia de diabetes, hipertensión arterial, obesidad y una mayor edad, pero con menor prevalencia de tabaquismo. La simvastatina y la atorvastatina fuerno los fármacos hipolipemiantes más consumidos, en términos de número de envases y DHD (dosis diarias definidas por 1.000 habitantes y día) así como también los más prescritos en prevención secundaria del infarto agudo de miocardio y del ictus isquémico aterotrombótico, duante los años 2006 y 2011 en el área Sanitaria II de Asturias. En general, en el consumo de fármacos en el Área Sanitaria II de Asturias entre los años 2006 y 2001 la simbastatian y la atorvastatina fueron los fármacos hipolipemiantes más consumidos y los indicadores existe una tendencia a la concentración del consumo en los principios activos simbastatina y atorvastatin

    Guidelines for representing complex cardinality constraints in binary and ternary relationships

    Get PDF
    Ternary relationships represent the association among three entities whose constraints database designers do not always know how to manage. In other words, it is very difficult for the designer to detect, represent and add constraints in a ternary relationship according to the domain requirements. To remedy the shortcomings in capturing the semantics required for the representation of this kind of relationship, the present paper discusses a practical method to motivate the designer's use of ternary relationships in a methodological framework. The method shows how to calculate cardinality constraints in binary and ternary relationships and to preserve the associated semantics until the implementation phase of the database development method.This work forms part of the ‘Thuban: Natural Interaction Platform for Virtual Attending in Real Environments’ project (TIN2008-02711), the Spanish Ministry of Industry, Tourism and Trade through the project Semants (TSI-020100-2009-419) and also by the Spanish research projects: MA2VICMR: Improving the access, analysis and visibility of the multilingual and multimedia information in web for the Region of Madrid (S2009/TIC-1542).Publicad
    corecore