1,414 research outputs found

    Do Campaign Contribution Limits Curb the Influence of Money in Politics?

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    Over 40% of countries around the world have adopted limits on campaign contributions to curb the influence of money in politics. Yet, we have limited knowledge on whether and how these limits achieve this goal. With a regression discontinuity design that uses institutional rules on contribution limits in Colombian municipalities, we show that looser limits increase the number and value of public contracts assigned to the winning candidate’s donors. The evidence suggests that this is explained by looser limits concentrating influence over the elected candidate among top donors and not by a reduction in electoral competition or changes in who runs for office. We further show that looser limits worsen the performance of donor-managed contracts: they are more likely to run over costs and require time extensions. Overall, this paper demonstrates a direct link between campaign contribution limits, donor kickbacks, and worse government contract performance

    Spectrum-Based Fault Localization in Model Transformations

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    Model transformations play a cornerstone role in Model-Driven Engineering (MDE), as they provide the essential mechanisms for manipulating and transforming models. The correctness of software built using MDE techniques greatly relies on the correctness of model transformations. However, it is challenging and error prone to debug them, and the situation gets more critical as the size and complexity of model transformations grow, where manual debugging is no longer possible. Spectrum-Based Fault Localization (SBFL) uses the results of test cases and their corresponding code coverage information to estimate the likelihood of each program component (e.g., statements) of being faulty. In this article we present an approach to apply SBFL for locating the faulty rules in model transformations. We evaluate the feasibility and accuracy of the approach by comparing the effectiveness of 18 different stateof- the-art SBFL techniques at locating faults in model transformations. Evaluation results revealed that the best techniques, namely Kulcynski2, Mountford, Ochiai, and Zoltar, lead the debugger to inspect a maximum of three rules to locate the bug in around 74% of the cases. Furthermore, we compare our approach with a static approach for fault localization in model transformations, observing a clear superiority of the proposed SBFL-based method.Comisión Interministerial de Ciencia y Tecnología TIN2015-70560-RJunta de Andalucía P12-TIC-186

    Benchmarking on the Automated Analyses of Feature Models: a Preliminary Roadmap

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    The automated analysis of Feature Models (FMs) is becoming a well-established discipline. New analysis operations, tools and techniques are rapidly proliferating in this context. However, the lack of standard mechanisms to evaluate and compare the performance of different solutions is starting to hinder the progress of this community. To address this situation, we propose the creation of a benchmark for the automated analyses of FMs. This benchmark would enable the objective and repeatable comparison of tools and techniques as well as promoting collaboration among the members of the discipline. Creating a benchmark requires a community to share a common view of the problem faced and come to agreement about a number of issues related to the design, distribution and usage of the benchmark. in this paper, we take a first step toward that direction. in particular, we first describe the main issues to be addressed for the successful development and maintenance of the benchmark. Then, we propose a preliminary research agenda setting milestones and clarifying the types of contributions expected from the community

    Weak precompactness in projective tensor products

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    The research was supported by grants PID2021-122126NB-C32 (J. Rodríguez) and PID2021-122126NB-C31 (A. Rueda Zoca), funded by MCIN/ AEI /10.13039/501100011033 and “ERDF A way of making Europe”, and also by grant 21955/PI/22 (funded by Fundación Séneca - ACyT Región de Murcia, Spain). The research of A. Rueda Zoca was also supported by grants FQM-0185 and PY20_00255 (funded by Junta de Andalucía, Spain).We give a sufficient condition for a pair of Banach spaces (X,Y) to have the following property: whenever W1⊆X and W2⊆Y are sets such that {x⊗y:x∈W1,y∈W2} is weakly precompact in the projective tensor product X⊗̂πY, then either W1 or W2 is relatively norm compact. For instance, such a property holds for the pair (ℓp,ℓq) if 1<p,q<∞ satisfy 1/p+1/q≥1. Other examples are given that allow us to provide alternative proofs to some results on multiplication operators due to Saksman and Tylli. We also revisit, with more direct proofs, some known results about the embeddability of ℓ1 into X⊗̂πY for arbitrary Banach spaces X and Y, in connection with the compactness of all operators from X to Y∗.PID2021-122126NB-C32PID2021-122126NB-C31MCIN/ AEI /10.13039/501100011033“ERDF A way of making Europe”Fundación Séneca - ACyT Región de Murcia, Spain 21955/PI/22Junta de Andalucía FQM-0185, PY20_0025

    A bacterial acetyltransferase targets the protein kinase ZIP1, a positive regulator of plant immunity

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    Pseudomonas syringae is a model bacterial pathogen that penetrates the leaf to reach the plant apoplast, where it replicates causing disease. In order to do that, the pathogen must interfere and suppress a two-tiered plant defense response: PTI (PAMP-Triggered Immunity, or basal resistance) and ETI (Effector-Triggered Immunity). P. syringae uses a type III secretion system to directly deliver effector proteins inside the plant cell cytosol, many of which are known to suppress PTI, some of which are known to trigger ETI, and a handful of which are known to suppress ETI. Bacterial infection can also trigger a systemic plant defense response that protects the plant against additional pathogen attacks known as SAR (Systemic Acquired Resistance). We are particularly interested in the molecular and cellular mechanisms involved in effector-mediated defense evasion by P. syringae, in particular those involved in the suppression of ETI and SAR, and/or mediation of hormone signaling. Here we present data describing effector-mediated interference with plant immunity, by means of acetylation of a key positive regulator of local and systemic responses. Our work identifies a novel plant target for effector function, and characterizes its function. This work illustrates how analyzing the means by which a given effector interferes with its target can provide novel information regarding eukaryotic molecular mechanisms.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. MINECO BIO2015-64391R y FEDE

    Towards the Automation of Metamorphic Testing in Model Transformations

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    Model transformations are the cornerstone of Model-Driven Engineering, and provide the essential mechanisms for manipulating and transforming models. Checking whether the output of a model transformation is correct is a manual and error-prone task, this is referred to as the oracle problem in the software testing literature. The correctness of the model transformation program is crucial for the proper generation of its output, so it should be tested. Metamorphic testing is a testing technique to alleviate the oracle problem consisting on exploiting the relations between different inputs and outputs of the program under test, so-called metamorphic relations. In this paper we give an insight into our approach to generically define metamorphic relations for model transformations, which can be automatically instantiated given any specific model transformation.Comisión Interministerial de Ciencia y Tecnología TIN2015-70560-RJunta de Andalucía TIC-5906Junta de Andalucía P12-TIC-186

    Estudio de las opiniones CTS entre profesores del bachillerato y universitarios de Química

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    Dentro del Proyecto Iberoamericano de Evaluación de Actitudes Relacionadas con la Ciencia, la Tecnología y la Sociedad (PIEARCTS), este grupo de investigadores vamos a centrarnos en verter las opiniones sobre las relaciones Ciencia-Tecnología-Sociedad (CTS) de profesores de dos niveles educativos públicos: el bachillerato y el profesional. Nuestra conclusión más importante es que encontramos una visión inadecuada relativamente similar en las dos muestras. Sin embargo hallamos diferencias en los aspectos más sociales de la NdC (en los que el profesorado del bachillerato tiene una mejor evaluación) y en los de definición científica (en los que están mejor los profesores del nivel profesional). Los dos grupos tuvieron visiones inadecuadas tanto en lo referente a la tecnología, a los aspectos de género, como en los factores epistemológicos

    Evolución de la ley (AG/CU) en monedas árabes durante los siglos VIII al X D.C mediante SEM-EDX y TXRF

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    En este trabajo se presenta el estudio analítico, mediante fluorescencia de ra yos X por reflexión total (TXRF) y microscopía electrónica de barrido con aná lisis de energía dispersiva de rayos X (SEM-EDX). de un amplio grupo de mo nedas islámicas (532 piezas), con el fin de establecer una correlación entre la ley de la moneda islámica en España y los acontecimientos históricos más relevan tes tícurridos durante los siglos VIII al X d.C. Los resultados analíticos obteni dos han permitido establecer el proceso de devaluación en la riqueza de la alea- ción Ag/Cu. en este período. Las tendencias observadas se correlacionan con el déficit de plata sufrido por el estado Omeya de Córdoba. Por otro lado, la com binación de las técnicas de TXRF y SEM-EDX ha permitido caracterizar de forma concluyente la tecnología de la producción, así como la evolución histórica su frida por este tipo de materiales
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