25,104 research outputs found

    Lobbyin to prevent commercial piracy

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    In this paper we develop a common agency model to analyze the problem of pirates entering the market, in which the incumbent and the consumers form pressure groups to lobby the government on policies to prevent piracy while the pirates try to avoid being stopped. We show that a monopoly is not an equilibrium when both the incumbent and consumers lobby the government, and that the cost of monitoring commercial piracy is very important in determining (truthful) equilibria, as is the case where there is no lobby competition. However, it is now more difficult getting the pirate to enter the market.Common Agency, Lobbying, Commercial Piracy, Incumbent, Consumers and Government

    Total synthesis of depudecin and analogues via an olefin cross-metathesis based strategy

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    (-)-Depudecin (1), isolated from the culture broths of the fungus Alternaria brassicicola [1], has been identified as a selective inhibitor of histone deacetylases (HDAC) with an IC50 in the low μM range. In contrast to representative HDAC inhibitors, depudecin represents a unique inhibitor of these enzymes by virtue of its molecular structure, featuring the presence of two oxirane rings separated by a trans double bond. Originally discovered as part of a biological screen directed towards the identification of antitumour agents with detransforming activity [2], depudecin was identified as a bioactive metabolite capable of reverting the transformed morphology of tumor cells. Depudecin induced cell cycle arrest and cellular differentiation [3], and also exhibited anti-angiogenesis activity [4]. Prompted by its striking biological properties and enticing structure, we decided to initiate a research program directed towards the synthesis of natural depudecin which has recently culminated with a linear total synthesis [5]. In order to develop an improved access to natural depudecin and analogues for further biological screenings, we explored a synthetic alternative as a shorter and more convergent approach. In this communication we report a new total synthesis of the natural product (-)-depudecin. A key feature of the synthesis is the utilization of an olefin cross-metathesis strategy, which provides for an efficient and improved access to natural depudecin. This strategy was applied to the preparation of the 10-epi and (+)-depudecin, which represent interesting stereoisomeric analogues for SAR studies.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Estimation of muscular forces from SSA smoothed sEMG signals calibrated by inverse dynamics-based physiological static optimization

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    The estimation of muscular forces is useful in several areas such as biomedical or rehabilitation engineering. As muscular forces cannot be measured in vivo non-invasively they must be estimated by using indirect measurements such as surface electromyography (sEMG) signals or by means of inverse dynamic (ID) analyses. This paper proposes an approach to estimate muscular forces based on both of them. The main idea is to tune a gain matrix so as to compute muscular forces from sEMG signals. To do so, a curve fitting process based on least-squares is carried out. The input is the sEMG signal filtered using singular spectrum analysis technique. The output corresponds to the muscular force estimated by the ID analysis of the recorded task, a dumbbell weightlifting. Once the model parameters are tuned, it is possible to obtain an estimation of muscular forces based on sEMG signal. This procedure might be used to predict muscular forces in vivo outside the space limitations of the gait analysis laboratory.Postprint (published version

    Conceptual Framework for the Use of Building Information Modeling in Engineering Education

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    The objective of this paper is to present a critical literature review of the Building Information Modelling (BIM) methodologyandtoanalyzewhetherBIMcanbeconsideredaVirtualLearningEnvironment.Aconceptualframeworkis proposed for using BIM in a university context. A search of documents was carried out in the Core Collection of Web of Science; it was restricted to the last five years (2013–2017). A total of 95 documents were analyzed; all documents were written in English and peer reviewed. BIM meets all the characteristics of Virtual Learning Environments. The proposed framework has three dimensions (competencies, pedagogical approach and level of integration).It allows for the planning and analysis of future experiences of teaching BIM in a university context.Ministry of Economy and Competitiveness of Spain and AEI/FEDER, UE Projects EDU2016-77007-RRegional Government of Extremadura (Spain) IB 16068Regional Government of Extremadura (Spain) GR1800

    How Bees Respond Differently to Field Margins of Shrubby and Herbaceous Plants in Intensive Agricultural Crops of the Mediterranean Area

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    (1) Intensive agriculture has a high impact on pollinating insects, and conservation strategies targeting agricultural landscapes may greatly contribute to their maintenance. The aim of this work was to quantify the effect that the vegetation of crop margins, with either herbaceous or shrubby plants, had on the abundance and diversity of bees in comparison to non-restored margins. (2) The work was carried out in an area of intensive agriculture in southern Spain. Bees were monitored visually and using pan traps, and floral resources were quantified in crop margins for two years. (3) An increase in the abundance and diversity of wild bees in restored margins was registered, compared to non-restored margins. Significant differences in the structure of bee communities were found between shrubby and herbaceous margins. Apis mellifera and mining bees were found to be more polylectic than wild Apidae and Megachilidae. The abundance of A. mellifera and mining bees was correlated to the total floral resources, in particular, to those offered by the Boraginaceae and Brassicaceae; wild Apidae and Megachilidae were associated with the Lamiaceae. (4) This work emphasises the importance of floral diversity and shrubby plants for the maintenance of rich bee communities in Mediterranean agricultural landscapes
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