12,259 research outputs found

    A planar magneto-inductive lens for three-dimensional subwavelength imaging

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    A planar near-field magnetoinductive lens operating in the microwave range is presented. The proposed device consists of two parallel planar arrays of metallic broadside coupled (BC-) split ring resonators (SRRs), or BC-SRRs. Power coming from a point-like source located in front of the lens is focused into a receiver located in free space behind the device. This focus is clearly removed from the back side of the lens, and has a size which is an order of magnitude smaller than the free space wavelength of the incoming radiation. The imaging properties of the device mainly relies on the excitation of magnetoinductive surface waves on the BC-SRR arrays. By simply scaling the BC-SRRs size, as well as the arrays periodicity, the frequency of operation of the device can be tuned over a wide frequency range. Thus the proposed design is potentially useful for many applications ranging from megahertzs to terahertzs.Comment: 14 pages, 3 figures, submitted to Applied Physics Letter

    Culturing Bursaphelenchus cocophilus in vitro and in vivo.

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    Red ring disease (RRD) is of particular importance in many African oil palms- and coconut-producing regions in Central and South America and the Caribbean. Its causal agent, the nematode Bursaphelenchus cocophilus (Cobb) Baujard, causes extensive damage to tissues in the plant trunk that typically leads to plant death within months. Nearly 100 years after its first report RRD remains understudied largely because the nematode cannot be cultured in vivo or in vitro, what hinders sustained research efforts on basic and applied aspects of the pathosystem. To overcome this problem we attempted in vivo culturing in coconut seedlings, paying attention to aspects that had been overlooked in previous trials. We also attempted in vitro culturing on several fungi endophytic to healthy and RRD-affected coconut trees. In the two in vivo assays performed we were able to recover hundreds of nematodes from the seedlings up to 60 days after inoculation, but the nematodes seemed unable to sustain parasitism in most seedlings. No nematode was recovered from the endophytic fungal cultures in neither of the two assays performed. Hence B. cocophilus continues to stand as the only obligatory plant-parasitic species of the speciose genus Bursaphelenchus and a somewhat intractable plant-parasitic nematode to study on

    The Epistemic Control Loop

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    In the ICEA project we are concerned with the extraction of general designs from rat brains

    Mobilizar: Capturing User Behavior with Mobile Digital Diaries

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    In this paper we present Mobilizar, a web-based mobile tool that facilitates the implementation and data collection of self-reported user behavior. Mobilizar was designed with both the researcher and the participant in mind. It provides investigators with a way to setup a new diary study in a matter of minutes and to electronically collect diary data from participants by using internet-enabled mobile devices. These devices promise to alleviate the burden of carrying a paper-and-pencil diary by instead using the participant’s own device. It also gives participants the flexibility to report their behavior in different ways such as making text, voice, or picture entries that fit their current situational constraints. In this paper, we describe the user interface design of Mobilizar and how it may be used to conduct diary studies with mobile devices

    Principles for Consciousness in Integrated Cognitive Control

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    In this article we will argue that given certain conditions for the evolution of bi- \ud ological controllers, these will necessarily evolve in the direction of incorporating \ud consciousness capabilities. We will also see what are the necessary mechanics for \ud the provision of these capabilities and extrapolate this vision to the world of artifi- \ud cial systems postulating seven design principles for conscious systems. This article \ud was published in the journal Neural Networks special issue on brain and conscious- \ud ness

    Sistema autónomo de monitoreo y suministro de agua en plantas de ornato

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    El cuidado al medio ambiente es una tarea que se debe realizar buscando estrategias para concientizar a la sociedad, fomentando una responsabilidad social. Es por ello que en este trabajo se plantea el sistema de un desarrollo autónomo capaz de mantener en condiciones óptimas el crecimiento y vida de las plantas de ornato. Otro factor importante es la influencia del sector laboral primario en el ámbito de desarrollo económico, por lo que es importante la implementación de nuevas tecnologías con el fin de desarrollar y optimizar los niveles de producción del sector primario. En este trabajo se propone un sistema diseñado mediante la teoría de control moderno el cual ayuda a la optimización del gasto de agua en una planta de ornato. Para esto se desarrollará un sistema de riego autónomo con la capacidad de regular el suministro de agua, estableciendo un monitoreo mediante una conexión con dispositivos móviles. Además, se busca la implementación de tecnología mexicana diseñada con la finalidad de incursionar en el ámbito de la manutención de plantas de ornato mediante la utilización de herramientas y equipo de bajo costo
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