5,794 research outputs found

    Extracellular matrix components are required to protect bacillus subtilis from pseudomonas invasion and co-colonization of plants

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    Plants are colonized by a vast variety of microbes. Among them, bacteria are the most predominant and are able to adapt to environmental changes and interact with other microorganisms using a wide array of molecules, metabolic plasticity and secretion systems. One way bacteria have evolved to succeed in this competitive scenario is the formation of biofilms which provides protection to the cells, modulates the flux of signals and controls cellular differentiation. Thus, efforts are encouraged to really determine the functionality of the bacterial extracellular matrix. In this study, we have employed microbiological and microscopic techniques to study the interaction between Bacillus subtilis 3610 and Pseudomonas chlororaphis PCL1606. We demonstrate the important role of the extracellular matrix in protecting B. subtilis colonies from infiltration by Pseudomonas. Furthermore, time-lapse confocal laser scanning microscopy (CLSM) analyses of the bacterial interactions have permitted to complete the study of the bacterial behaviors and to measure bacterial expansion rates. Surprising, we find that the Pseudomonas type VI secretion system (T6SS) is required in the cell-to-cell contact with matrix-impaired B. subtilis cells, revealing a novel role for T6SS against Gram-positive bacteria. In response to P. chlororaphis infiltration, we find that B. subtilis activates sporulation and expresses motility-related genes. Confocal microscopy of the bacterial interactions using plant organs highlights the functional importance of these different bacterial strategies in their coexistence as stable bacterial communities. The findings further our understanding of the functional role played by biofilms in mediating bacterial social interactions.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    A new QoS routing algorithm based on self-organizing maps for wireless sensor networks

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    For the past ten years, many authors have focused their investigations in wireless sensor networks. Different researching issues have been extensively developed: power consumption, MAC protocols, self-organizing network algorithms, data-aggregation schemes, routing protocols, QoS management, etc. Due to the constraints on data processing and power consumption, the use of artificial intelligence has been historically discarded. However, in some special scenarios the features of neural networks are appropriate to develop complex tasks such as path discovery. In this paper, we explore and compare the performance of two very well known routing paradigms, directed diffusion and Energy- Aware Routing, with our routing algorithm, named SIR, which has the novelty of being based on the introduction of neural networks in every sensor node. Extensive simulations over our wireless sensor network simulator, OLIMPO, have been carried out to study the efficiency of the introduction of neural networks. A comparison of the results obtained with every routing protocol is analyzed. This paper attempts to encourage the use of artificial intelligence techniques in wireless sensor nodes

    Using artificial intelligence in routing schemes for wireless networks

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    For the latest 10 years, many authors have focused their investigations in wireless sensor networks. Different researching issues have been extensively developed: power consumption, MAC protocols, self-organizing network algorithms, data-aggregation schemes, routing protocols, QoS management, etc. Due to the constraints on data processing and power consumption, the use of artificial intelligence has been historically discarded. However, in some special scenarios the features of neural networks are appropriate to develop complex tasks such as path discovery. In this paper, we explore the performance of two very well-known routing paradigms, directed diffusion and Energy-Aware Routing, and our routing algorithm, named SIR, which has the novelty of being based on the introduction of neural networks in every sensor node. Extensive simulations over our wireless sensor network simulator, OLIMPO, have been carried out to study the efficiency of the introduction of neural networks. A comparison of the results obtained with every routing protocol is analyzed. This paper attempts to encourage the use of artificial intelligence techniques in wireless sensor nodes

    Monitoring and Fault Location Sensor Network for Underground Distribution Lines

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    One of the fundamental tasks of electric distribution utilities is guaranteeing a continuous supply of electricity to their customers. The primary distribution network is a critical part of these facilities because a fault in it could affect thousands of customers. However, the complexity of this network has been increased with the irruption of distributed generation, typical in a Smart Grid and which has significantly complicated some of the analyses, making it impossible to apply traditional techniques. This problem is intensified in underground lines where access is limited. As a possible solution, this paper proposes to make a deployment of a distributed sensor network along the power lines. This network proposes taking advantage of its distributed character to support new approaches of these analyses. In this sense, this paper describes the aquiculture of the proposed network (adapted to the power grid) based on nodes that use power line communication and energy harvesting techniques. In this sense, it also describes the implementation of a real prototype that has been used in some experiments to validate this technological adaptation. Additionally, beyond a simple use for monitoring, this paper also proposes the use of this approach to solve two typical distribution system operator problems, such as: fault location and failure forecasting in power cables.Ministerio de Economía y Competitividad, Government of Spain project Sistema Inteligente Inalámbrico para Análisis y Monitorización de Líneas de Tensión Subterráneas en Smart Grids (SIIAM) TEC2013-40767-RMinisterio de Educación, Cultura y Deporte, Government of Spain, for the funding of the scholarship Formación de Profesorado Universitario 2016 (FPU 2016

    Using Artificial Intelligence in Wireless Sensor Routing Protocols

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    This paper represents a dissertation about how an artificial intelligence technique can be applied to wireless sensor networks. Due to the constraints on data processing and power consumption, the use of artificial intelligence has been historically discarded in these kind of networks. However, in some special scenarios the features of neural networks are appropriate to develop complex tasks such as path discovery. In this paper, we explore the performance of two very well known routing paradigms, directed diffusion and Energy-Aware Routing, and our routing algorithm, named SIR, which has the novelty of being based on the introduction of neural networks in every sensor node. Extensive simulations over our wireless sensor network simulator, OLIMPO, have been carried out to study the efficiency of the introduction of neural networks. A comparison of the results obtained with every routing protocol is analyzed

    Giving Neurons to Sensors: An Approach to QoS Management Through Artificial Intelligence in Wireless Networks

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    For the latest ten years, many authors have focused their investigations in wireless sensor networks. Different researching issues have been extensively developed: power consumption, MAC protocols, selforganizing network algorithms, data-aggregation schemes, routing protocols, QoS management, etc. Due to the constraints on data processing and power consumption, the use of artificial intelligence has been historically discarded. However, in some special scenarios the features of neural networks are appropriate to develop complex tasks such as path discovery. In this paper, we explore the performance of two very well known routing paradigms, directed diffusion and Energy-Aware Routing, and our routing algorithm, named SIR, which has the novelty of being based on the introduction of neural networks in every sensor node. Extensive simulations over our wireless sensor network simulator, OLIMPO, have been carried out to study the efficiency of the introduction of neural networks. A comparison of the results obtained with every routing protocol is analyzed. This paper attempts to encourage the use of artificial intelligence techniques in wireless sensor nodes

    Workers health: new-old questions

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    This theoretical paper for debate presents three crucial questions about the workers health subject: (a) the absence of a National Policy that gives a conceptual fundament, guides for implementation, strategies and plans for action and evaluation of its effectivity; (b) fragmentation and dispersion of the scientific production of the area, defaulting the important contribution that the academic sector could offer for fundament the action of health policy makers, social movements, executives and professionals of the area; (c) weakness and low capacity of social movements and workers representative groups, in the actual crises resulted of the productive restructuring, to formulate qualified demands for respond with adequate instruments the contemporary problems of the workers situation in Brazil. The method used to construct this article was a critical revision of the official documents and of the scientific production of the area named in Brazil as workers health movement. They founded the analyses and the emergent questions. The theoretical basis comes from the literature about productive restructuring in Brazil, mainly that who treats about its worse effects in the health of working class population; and classic texts that articulate the workers' health knowledge field.Como artigo para debate, este texto apresenta três questões consideradas cruciais pelos autores: (a) ausência de uma efetiva Política Nacional de Saúde do Trabalhador que coloque um marco conceitual claro, apresente diretrizes de implementação e proponha estratégias e planos de ação e de avaliação para efetivá-la; (b) fragmentação e dispersão da produção científica da área, prejudicando a importante colaboração que a Academia poderia oferecer para fundamentar as necessidades dos agentes políticos, movimentos sociais, gestores e profissionais de saúde; (c) enfraquecimento e pouca capacidade de pressão dos movimentos sociais e dos trabalhadores, evidenciando a falta de qualificação das demandas, diante dos desafios do momento presente do mundo do trabalho no Brasil. O método deste trabalho consistiu na revisão crítica de documentos e publicações da área a fim de fundamentar o tom do debate e as questões levantadas. As bases teóricas de toda a argumentação são os textos que tratam da reestruturação produtiva no Brasil, sobretudo os que analisam os efeitos nefastos desse processo e, também, os fundamentos do chamado campo de saúde do trabalhador.Fiocruz Escola Nacional de Saúde Pública Centro de Estudos da Saúde do Trabalhador e Ecologia HumanaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Planejamento em SaúdeUNIFESP, EPM, Planejamento em SaúdeSciEL

    SIR: A New Wireless Sensor Network Routing Protocol Based on Artificial Intelligence

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    Currently, Wireless Sensor Networks (WSNs) are formed by hundreds of low energy and low cost micro-electro-mechanical systems. Routing and low power consumption have become important research issues to interconnect this kind of networks. However, conventional Quality of Service routing models, are not suitable for ad hoc sensor networks, due to the dynamic nature of such systems. This paper introduces a new QoS-driven routing algorithm, named SIR: Sensor Intelligence Routing. We have designed an artificial neural network based on Kohonen self organizing features map. Every node implements this artificial neural network forming a distributed intelligence and ubiquitous computing system

    Giving neurons to sensors. QoS management in wireless sensors networks

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    Public utilities services (gas, water and electricity) have been traditionally automated with several technologies. The main functions that these technologies must support are AMR, Automated Meter Reading, and SCADA, Supervisory Control And Data Acquisition. Most meter manufacturers provide devices with Bluetoothr or ZigBeeTM communication features. This characteristic has allowed the inclusion of wireless sensor networks (WSN) in these systems. Once WSNs have appeared in such a scenario, real-time AMR and SCADA applications can be developed with low cost. Data must be routed from every meter to a base station. This paper describes the use of a novel QoS-driven routing algorithm, named SIR: Sensor Intelligence Routing, over a network of meters. An arti cial neural network is introduced in every node to manage the routes that data have to follow. The resulting system is named Intelligent Wireless Sensor Network (IWSN)

    Rampant Arch and Its Optimum Geometrical Generation

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    Gothic art was developed in western Europe from the second half of the 12th century to the end of the 15th century. The most characteristic Gothic building is the cathedral. Gothic architecture uses well-carved stone ashlars, and its essential elements include the arch. The thrust is transferred by means of external arches (flying buttresses) to external buttresses that end in pinnacles, which accentuates the verticality. The evolution of the flying buttresses should not only be considered as an aesthetic consideration, but also from a constructive point of view as an element of transmission of forces or loads. Thus, one evolves from a beam-type buttress to a simple arch, and finally to a rampant arch. In this work, we study the geometry of the rampant arch to determine which is the optimum from the constructive point of view. The optimum rampant arch obtained is the one with the common tangent to the two arches parallel to the slope line. A computer program was created to determine this optimal rampant arch by means of a numerical or graphical input. It was applied to several well-known and representative cases of Gothic art in France (church of Saint Urbain de Troyes) and Spain (Cathedral of Palma de Mallorca), establishing if they were designs of optimal rampant arches or not
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