5,794 research outputs found
Extracellular matrix components are required to protect bacillus subtilis from pseudomonas invasion and co-colonization of plants
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
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
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
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
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
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
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
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
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
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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