1,918 research outputs found

    A tool for domain-independent model mutation

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    Mutation is a systematic technique to create variants of a seed artefact by means of mutation operators. It has many applications in computer science, like software testing, automatic exercise generation and design space exploration. Typically, mutation frameworks are developed ad-hoc by implementing mutation operators and their application strategies from scratch, using general-purpose programming languages. However, this is costly and error-prone. To improve this situation, we propose WODEL: a domain-specific language and tool for model-based mutation that is independent of the domain meta-model. WODELenables the rapid development and application of model mutations. It provides built-in advanced functionalities like automatic generation of seed models, and static and dynamic metrics of operator coverage and applicability. It offers extension points, e.g., to post-process mutants and describe domain-specific equivalence criteria. As an example, we illustrate the usage of WODEL for the mutation of security policies, and present an empirical evaluation of its expressiveness.Work partially funded by project FLEXOR (Spanish MINECO, TIN2014- 52129-R), project DArDOS (Spanish MINECO/FEDER TIN2015-65845-C3-1- R) and the R&D programme of the Madrid Region (S2013/ICE-3006

    Systematic engineering of mutation operators

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    In the context of software engineering, mutation consists in injecting small changes in artefacts – like models, programs, or data – for purposes like (mutation) testing, test data generation, and all sorts of search-based methods. These tasks typically require defining sets of mutation operators, which are often built ad-hoc because there is currently poor support for their development and testing. To improve this situation, we propose a methodology and corresponding tool support for the proper engineering of mutation operators. Our proposal is model-based, representing the artefacts to be mutated as models. It includes a domain-specific language to describe the mutation operators, facilities to synthesize models that can be used to test the operators, different metrics to analyse operator coverage, and services to generate operators when the coverage is insufficient. We show automated support atop the WODEL tool, and illustrate its use by defining mutation operators for UML Class Diagrams.This work has been partially funded by the Spanish Ministry of Science (RTI2018-095255-B-I00), by the R&D programme of the Madrid Region (S2018/TCS-4314) and by the Spanish MINECO-FEDER (grant number FAME RTI2018-093608-BC31

    La equidad tributaria en las cooperativas financieras y las empresas de capitales en México

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     El objetivo del trabajo se enfoca en realizar una comparación entre la estructura tributaria de las empresas de capitales y de las cooperativas financieras en México; considerando que las primeras se centran en la maximización de la riqueza, mientras que las cooperativas cumplen con objetivos sociales y económicos en beneficio de una colectividad. Lo que se pretende es esclarecer cuál es el rol del principio de equidad en los impuestos directos e indirectos que aplican a ambas figuras jurídicas e identificar las razones por las que se les otorgan incentivos tributarios. Para tal efecto fue seleccionado el método de investigación exegético y el estudio de la doctrina jurídica para el análisis de las normas que aplican al objeto de estudio. Hecho lo anterior, pudo establecerse que las cooperativas financieras y las empresas de capitales, están supeditadas a tratamientos diferenciados en materia tributaria, toda vez que existen argumentos justificados, para que a las primeras les sean asignados incentivos que atenúen o eliminen la carga fiscal, mediante reducciones o exenciones en el pago de determinados tributos, lo que de ninguna manera debe considerarse un privilegio, sino el reconocimiento por parte del Estado, de la contribución que las cooperativas hacen en favor del desarrollo nacional; no obstante, al mismo tiempo se presentan desventajas regulatorias frente a las empresas de capitales, lo que impide que las cooperativas se posiciones competitivamente en el mercado.--------------------------------------------------------------------------The aim of this paper is to compare the tax structure of capital companies and financial cooperatives in Mexico; considering that the former focus on the maximization of wealth, while cooperatives fulfill social and economic objectives for the benefit of a community. The goal is to clarify the role of the principle of equity in the direct and indirect taxes that apply to both legal entities and to identify the reasons by which are granted tax incentives. For this purpose, the method of exegetical research and the study of legal doctrine for the analysis of the norms that applied to the object of study were selected. As a result, it was possible to establish that financial cooperatives and capital companies are liable to differentiated treatment in tax matters, since there are justified arguments, so that the former are given incentives to mitigate or eliminate the tax burden, through Reductions or exemptions in the payment of certain taxes, which in no way should be considered a privilege, but the recognition by the State of the contribution that cooperatives make in favor of national development; However, at the same time there are regulatory disadvantages vis-à-vis capital companies, which prevents cooperatives from competing in the market.Artículo revisado por pare

    Cloning and characterization of a pectin lyase gene from Colletotrichum lindemuthianum and comparative phylogenetic/structural analyses with genes from phytopathogenic and saprophytic/opportunistic microorganisms

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    <p>Abstract</p> <p>Background</p> <p>Microorganisms produce cell-wall-degrading enzymes as part of their strategies for plant invasion/nutrition. Among these, pectin lyases (PNLs) catalyze the depolymerization of esterified pectin by a β-elimination mechanism. PNLs are grouped together with pectate lyases (PL) in Family 1 of the polysaccharide lyases, as they share a conserved structure in a parallel β-helix. The best-characterized fungal pectin lyases are obtained from saprophytic/opportunistic fungi in the genera <it>Aspergillus </it>and <it>Penicillium </it>and from some pathogens such as <it>Colletotrichum gloeosporioides</it>.</p> <p>The organism used in the present study, <it>Colletotrichum lindemuthianum</it>, is a phytopathogenic fungus that can be subdivided into different physiological races with different capacities to infect its host, <it>Phaseolus vulgaris</it>. These include the non-pathogenic and pathogenic strains known as races 0 and 1472, respectively.</p> <p>Results</p> <p>Here we report the isolation and sequence analysis of the <it>Clpnl2 </it>gene, which encodes the pectin lyase 2 of <it>C. lindemuthianum</it>, and its expression in pathogenic and non-pathogenic races of <it>C. lindemuthianum </it>grown on different carbon sources. In addition, we performed a phylogenetic analysis of the deduced amino acid sequence of Clpnl2 based on reported sequences of PNLs from other sources and compared the three-dimensional structure of Clpnl2, as predicted by homology modeling, with those of other organisms. Both analyses revealed an early separation of bacterial pectin lyases from those found in fungi and oomycetes. Furthermore, two groups could be distinguished among the enzymes from fungi and oomycetes: one comprising enzymes from mostly saprophytic/opportunistic fungi and the other formed mainly by enzymes from pathogenic fungi and oomycetes. Clpnl2 was found in the latter group and was grouped together with the pectin lyase from <it>C. gloeosporioides</it>.</p> <p>Conclusions</p> <p>The <it>Clpnl2 </it>gene of <it>C. lindemuthianum </it>shares the characteristic elements of genes coding for pectin lyases. A time-course analysis revealed significant differences between the two fungal races in terms of the expression of <it>Clpnl2 </it>encoding for pectin lyase 2. According to the results, pectin lyases from bacteria and fungi separated early during evolution. Likewise, the enzymes from fungi and oomycetes diverged in accordance with their differing lifestyles. It is possible that the diversity and nature of the assimilatory carbon substrates processed by these organisms played a determinant role in this phenomenon.</p

    Solar energetic electron events measured by MESSENGER and Solar Orbiter. Peak intensity and energy spectrum radial dependences: statistical analysis

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    Context/Aims: We present a list of 61 solar energetic electron (SEE) events measured by the MESSENGER mission and the radial dependences of the electron peak intensity and the peak-intensity energy spectrum. The analysis comprises the period from 2010 to 2015, when MESSENGER heliocentric distance varied between 0.31 and 0.47 au. We also show the radial dependencies for a shorter list of 12 SEE events measured in February and March 2022 by spacecraft near 1 au and by Solar Orbiter around its first close perihelion at 0.32 au. Results: Due to the elevated background intensity level of the particle instrument on board MESSENGER, the SEE events measured by this mission are necessarily large and intense; most of them accompanied by a CME-driven shock, being widespread in heliolongitude, and displaying relativistic (\sim1 MeV) electron intensity enhancements. The two main conclusions derived from the analysis of the large SEE events measured by MESSENGER, which are generally supported by Solar Orbiter's data results, are: (1) There is a wide variability in the radial dependence of the electron peak intensity between \sim0.3 au and \sim1 au, but the peak intensities of the energetic electrons decrease with radial distance from the Sun in 27 out of 28 events. On average and within the uncertainties, we find a radial dependence consistent with R3R^{-3}. (2) The electron spectral index found in the energy range around 200 keV (δ\delta200) of the backward-scattered population near 0.3 au measured by MESSENGER is harder in 19 out of 20 (15 out of 18) events by a median factor of \sim20% (\sim10%) when comparing to the anti-sunward propagating beam (backward-scattered population) near 1 au.Comment: 20 pages, 13 figure

    Propaganda and (un)covered identities in treatises and sermons : Christians, Jews, and Muslims in the premodern Mediterranean

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    The eleven essays included in this collective volume examine a range of textual genres produced by Christians and Muslims throughout the Mediterranean, including materials from the Corpus Islamolatinum, Christian propaganda and polemical works targeting Muslims and Jews, Inquisition records, and Christian and Muslim sermons. Despite the diversity of the works under consideration and the variety of methodological and disciplinary approaches employed in their analysis, the volume is bound together by the common goals of exploring the propaganda strategies premodern authors deployed for specific aims, be it the unification of religious, cultural, and political groups through discourses of self-representation, or the invention of the political, cultural, religious, or gendered other. Many of the essays offer critical re-readings of works that are obscure or have never been studied, while others shed new light on the cultural and textual interactions between Christians, Muslims and Jews. The volume is divided into four sections, the first of which is comprised of three chapters on the Corpus Islamolatinum that furnish new evidence showing the important role this "encyclopedia" played in spreading knowledge about Islam and contributing to the creation of propaganda and polemics against Islam among European intellectual circles. The chapters in section two offer novel interpretations of the hermeneutical strategies underlying the composition of polemical works such as the lives of Muhammad and Pedro de la Cavalleria's Zelus Christi. The essays in section three identify some common hermeneutical strategies in the use of anti-Jewish and anti-Islamic arguments to polemicize against religious others or edify Christians and illuminate intertextual relations between authors and genres (disputatio and praedicatio). Finally, section four introduces the gender perspective: the genered nature of the accusations of Judaizing in the analysis of the transcripts of the inquisitorial court of three sisters who were tried in Barcelona in 1496, on the one hand, and two studies that explore the constructions of identities and gender relations reflected in various Islamic sources from opposite ends of the Mediterranean. They offer glimpses of women as subject (s) and as object (s) of preaching and show how such texts can reify or subvert traditional binary gender role

    Engineering the Controlled Assembly of Filamentous Injectisomes in E. coli K-12 for Protein Translocation into Mammalian Cells.

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    Bacterial pathogens containing type III protein secretion systems (T3SS) assemble large needle-like protein complexes in the bacterial envelope, called injectisomes, for translocation of protein effectors into host cells. The application of these molecular syringes for the injection of proteins into mammalian cells is hindered by their structural and genomic complexity, requiring multiple polypeptides encoded along with effectors in various transcriptional units (TUs) with intricate regulation. In this work, we have rationally designed the controlled expression of the filamentous injectisomes found in enteropathogenic Escherichia coli (EPEC) in the nonpathogenic strain E. coli K-12. All structural components of EPEC injectisomes, encoded in a genomic island called the locus of enterocyte effacement (LEE), were engineered in five TUs (eLEEs) excluding effectors, promoters and transcriptional regulators. These eLEEs were placed under the control of the IPTG-inducible promoter Ptac and integrated into specific chromosomal sites of E. coli K-12 using a marker-less strategy. The resulting strain, named synthetic injector E. coli (SIEC), assembles filamentous injectisomes similar to those in EPEC. SIEC injectisomes form pores in the host plasma membrane and are able to translocate T3-substrate proteins (e.g., translocated intimin receptor, Tir) into the cytoplasm of HeLa cells reproducing the phenotypes of intimate attachment and polymerization of actin-pedestals elicited by EPEC bacteria. Hence, SIEC strain allows the controlled expression of functional filamentous injectisomes for efficient translocation of proteins with T3S-signals into mammalian cells

    Changes in health behaviors, mental and physical health among older adults under severe lockdown restrictions during the covid-19 pandemic in spain

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    We used data from 3041 participants in four cohorts of community-dwelling individuals aged =65 years in Spain collected through a pre-pandemic face-to-face interview and a telephone interview conducted between weeks 7 to 15 after the beginning of the COVID-19 lockdown. On average, the confinement was not associated with a deterioration in lifestyle risk factors (smoking, alcohol intake, diet, or weight), except for a decreased physical activity and increased sedentary time, which reversed with the end of confinement. However, chronic pain worsened, and moderate declines in mental health, that did not seem to reverse after restrictions were lifted, were observed. Males, older adults with greater social isolation or greater feelings of loneliness, those with poorer housing conditions, as well as those with a higher prevalence of chronic morbidities were at increased risk of developing unhealthier lifestyles or mental health declines with confinement. On the other hand, previously having a greater adherence to the Mediterranean diet and doing more physical activity protected older adults from developing unhealthier lifestyles with confinement. If an-other lockdown were imposed during this or future pandemics, public health programs should spe-cially address the needs of older individuals with male sex, greater social isolation, sub-optimal housing conditions, and chronic morbidities because of their greater vulnerability to the enacted movement restrictions. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Dynamical Patterns of Cattle Trade Movements

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    Despite their importance for the spread of zoonotic diseases, our understanding of the dynamical aspects characterizing the movements of farmed animal populations remains limited as these systems are traditionally studied as static objects and through simplified approximations. By leveraging on the network science approach, here we are able for the first time to fully analyze the longitudinal dataset of Italian cattle movements that reports the mobility of individual animals among farms on a daily basis. The complexity and inter-relations between topology, function and dynamical nature of the system are characterized at different spatial and time resolutions, in order to uncover patterns and vulnerabilities fundamental for the definition of targeted prevention and control measures for zoonotic diseases. Results show how the stationarity of statistical distributions coexists with a strong and non-trivial evolutionary dynamics at the node and link levels, on all timescales. Traditional static views of the displacement network hide important patterns of structural changes affecting nodes' centrality and farms' spreading potential, thus limiting the efficiency of interventions based on partial longitudinal information. By fully taking into account the longitudinal dimension, we propose a novel definition of dynamical motifs that is able to uncover the presence of a temporal arrow describing the evolution of the system and the causality patterns of its displacements, shedding light on mechanisms that may play a crucial role in the definition of preventive actions
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