1,577 research outputs found

    Efeitos do solo e clima numa vinha de uva de mesa com cultura de cobertura. Gestão da rega utilizando redes de sensores

    Get PDF
    [ENG] TThe use of mulches in vineyards and orchards is a traditional agricultural practice used with the aim of saving moisture, reducing weed growth and improving organic matter content in the soil. In table grape vineyards trained to overhead system in Puglia region (Southeastern Italy), plastic sheets covering the canopy are often used to either advance ripening or delay harvest. In this environment, the living mulches could contribute to the modification of the microclimate around the canopy below the plastic sheets. This condition has an influence on the climatic demand and on both the vegetative and productive activities, mainly in stages with a high evapotranspiration. However, the presence of living mulches could increase the demand of available water and nutrient resources and this could cause a lower yield. The aim of this study was to acquire a suitable knowledge to manage irrigation and verify the influences of living mulches on the vine by using wireless sensor networks to measure the vapor pressure deficit, soil water potential and content.[POR] A utilização de coberturas do solo em vinhas e pomares é uma prática agrícola tradicional, utilizada com o objetivo de preservar a humidade do solo, reduzir o crescimento de infestantes e melhorar o teor de matéria orgânica no solo. Em vinhas de uva de mesa, conduzidas em sistema de pérgula na região de Puglia (sudeste da Itália), são frequentemente usadas coberturas de plástico para promover o avanço da maturação ou o atraso da colheita. Neste ambiente a utilização de enrelvamentos pode contribuir para a modificação do microclima do copado. Esta condição pode influenciar a demanda atmosférica, bem como a atividade vegetativa e reprodutiva da videira, principalmente em períodos de elevada evapotranspiração. No entanto, a presença do enrelvamento pode originar um aumento da demanda dos recursos disponíveis, nomeadamente água e nutrientes, o que poderá provocar uma quebra de produção. O objetivo deste estudo foi adquirir conhecimento para a gestão da rega e, simultaneamente, verificar a influência dos enrelvamentos na atividade da videira, usando para o efeito redes de sensores “sem fio” para medir o déficit de pressão de vapor, o potencial e o conteúdo de água no solo.The development of this work was supported by: The Spanish Ministry of Science and Innovation through the project RIDEFRUT (ref. AGL2013-49047-C2-1-R), the “Fundacion Seneca, Agencia de Ciencia y Tecnologia” of the Region of Murcia under the “Excelence Group Program”, and the Technical University of Cartagena under the PMPDI Program

    Dynamically Weighted Factor-Graph for Feature-based Geo-localization

    Full text link
    Feature-based geo-localization relies on associating features extracted from aerial imagery with those detected by the vehicle's sensors. This requires that the type of landmarks must be observable from both sources. This no-variety of feature types generates poor representations that lead to outliers and deviations, produced by ambiguities and lack of detections respectively. To mitigate these drawbacks, in this paper, we present a dynamically weighted factor graph model for the vehicle's trajectory estimation. The weight adjustment in this implementation depends on information quantification in the detections performed using a LiDAR sensor. Also, a prior (GNSS-based) error estimation is included in the model. Then, when the representation becomes ambiguous or sparse, the weights are dynamically adjusted to rely on the corrected prior trajectory, mitigating in this way outliers and deviations. We compare our method against state-of-the-art geo-localization ones in a challenging ambiguous environment, where we also cause detection losses. We demonstrate mitigation of the mentioned drawbacks where the other methods fail.Comment: This paper is under review at the journal "IEEE Robotics and Automation Letters

    Commissioning and First Observations with Wide FastCam at the Telescopio Carlos S\'anchez

    Get PDF
    The FastCam instrument platform, jointly developed by the IAC and the UPCT, allows, in real-time, acquisition, selection and storage of images with a resolution that reaches the diffraction limit of medium-sized telescopes. FastCam incorporates a specially designed software package to analyse series of tens of thousands of images in parallel with the data acquisition at the telescope. Wide FastCam is a new instrument that, using the same software for data acquisition, does not look for lucky imaging but fast observations in a much larger field of view. Here we describe the commissioning process and first observations with Wide FastCam at the Telescopio Carlos S\'anchez (TCS) in the Observatorio del Teide.Comment: 7 pages, 8 figures, Proc. SPIE. 9908, Ground-based and Airborne Instrumentation for Astronomy VI, 99082O. (August 09, 2016

    Expression of LPP3 in Bergmann glia is required for proper cerebellar sphingosine-1-phosphate metabolism/signaling and development

    Get PDF
    Bioactive lipids serve as intracellular and extracellular mediators in cell signaling in normal and pathological conditions. Here we describe that an important regulator of some of these lipids, the lipid phosphate phosphatase-3 (LPP3), is abundantly expressed in specific plasma membrane domains of Bergmann glia (BG), a specialized type of astrocyte with key roles in cerebellum development and physiology. Mice selectively lacking expression of LPP3/Ppap2b in the nervous system are viable and fertile but exhibit defects in postnatal cerebellum development and modifications in the cytoarchitecture and arrangement of BG with a mild non-progressive motor coordination defect. Lipid and gene profiling studies in combination with pharmacological treatments suggest that most of these effects are associated with alterations in sphingosine-1- phosphate (S1P) metabolism and signaling. Altogether our data indicate that LPP3 participates in several aspects of neuron-glia communication required for proper cerebellum developmen

    Interaction of Mitochondrial and Epigenetic Regulation in Hepatocellular Carcinoma

    Get PDF
    Hepatocellular carcinoma (HCC) is a pathology preceded mainly by cirrhosis of diverse etiology and is associated with uncontrolled dedifferentiation and cell proliferation processes. Many cellular functions are dependent on mitochondrial function, among which we can mention the enzymatic activity of PARP-1 and sirtuin 1, epigenetic regulation of gene expression, apoptosis, and so on. Mitochondrial dysfunction is related to liver diseases including cirrhosis and HCC; the energetic demand is not properly supplied and mitochondrial morphologic changes have been observed, resulting in an altered metabolism. There is a strong relationship between epigenetics and mitochondrion since the first one is dependent on the correct function of the last one. There is an interest to improve or to maintain mitochondrial integrity in order to prevent or reverse HCC; such is the case of IFC-305 that has a beneficial effect on mitochondrial function in a sequential model of cirrhosis-HCC. In this model, IFC-305 downregulates the expression of PCNA, thymidylate synthase, HGF and its receptor c-Met and upregulates the cell cycle inhibitor p27, thereby decreasing cell proliferation. Both effects, improvement of mitochondria function and reduction of tumor proliferation, suggest its use as HCC chemoprevention or as an adjuvant in chemotherapy

    High performance silicon photonic devices based on practical metamaterials

    Get PDF
    Robert Halir, et al., "High performance silicon photonic devices based on practical metamaterials," OECC/PSC, 7-12 July 2019, Fukuoka (Japan)Subwavelength grating metamaterials are enabling a new generation of high-performance silicon photonic devices. Here we discuss the fundamental physics along with some of the latest advances in this rapidly expanding field.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Ministerio de Economía y Competitividad, Programa Estatal de Investigación Orientada a los Retos de la Sociedad (cofinanciado FEDER) – TEC2016-80718-R, TEC2015-71127-C2-1-R (FPI BES-2016-077798) and IJCI-2016-30484; Community of Madrid – S2018/NMT-4326, Marie Sklodowska-Curie –734331, Czech Science Foundation – 1900062

    Success versus failure: Efficient heat devices in thermodynamics

    Get PDF
    J.G.A. acknowledges financial support from University of Salamanca, with Contract No. 0218 463AB01, and A.M. and J.A.W. under Contract No. 18.KB.YF/463A.C.01.[EN]Classical equilibrium thermodynamics provides, in a general way, upper Carnot bounds for the performance of energy converters. Nevertheless, to suggest lower bounds is a much more subtle issue, especially when they are related to a definition of convenience. Here, this issue is investigated in a unified way for heat engines, refrigerators, and heat pumps. First, irreversibilities are weighted in the context of heat reservoir stability for irreversible engines by using the thermodynamic distance between minimum energy and maximum entropy steady states. Some stability coefficients can be related to a majorization process and the obtention of Pareto fronts, linking stability and optimization by means of efficiency and entropy due to correlations between system and reservoirs. Second, these findings are interpreted in a very simple context. A region where the heat device is efficient is defined in a general scheme and, below this zone, the heat device is inefficient in the sense that irreversibilities somehow dominate its behavior. These findings allow for a clearer understanding of the role played by some well-known figures of merit in the scope of finite-time and -size optimization. Comparison with experimental results is provided

    Diseño de plan de marketing digital. Caso práctico: Agroindustria La Quiruba.

    Get PDF
    El mundo cambiante de la actualidad y el avance tecnológico globalizado exige cada vez más a las empresas a brindar beneficios mucho más grandes a sus clientes y ofertar a los potenciales, cualidades y ventajas que la competencia no les pueda ofrecer. Como se conoce, con el paso del tiempo la evolución tecnológica ha desarrollado innumerables plataformas tanto tradicionales como digitales, que le permiten al cliente obtener información clave y relevante de los elementos que le permiten satisfacer las necesidades y deseos que presenta en su existencia. También, a las empresas le genera mayor visibilidad y una comunicación personalizada con sus clientes, generando confianza y lealtad hacia la marca. Es por ello que, se presenta la investigación, donde se logra encontrar puntos claves y característicos de los consumidores actuales, que permitan brindar información útil para Agroindustrias La Quiruba que se define como la empresa en estudio, con el propósito de revalorizar los activos digitales que usa actualmente, en donde se pueda traducir a mayores seguidores y estos a mayores clientes. Agroindustria La Quiruba es una microempresa en constante crecimiento. A sus cinco años de haber iniciado sus operaciones, ha logrado un reconocimiento y aceptación positiva a nivel nacional e internacional, siendo únicos y exclusivos en la elaboración de productos 100% naturales y libres de preservantes, generando un control riguroso en toda la cadena de valor. Esta empresa elabora productos como: Pestos de loroco, salsa de tomate con loroco, salsas picantes a base de jocote y chile espuela de gallo, néctar de jocote, entre otros. La empresa está ubicada en San Lorenzo Ahuachapán, al occidente del país. A través de la investigación, se determinaron elementos valiosos a considerar, por ejemplo, es de resaltar los productos insignias de la marca, que son el pesto de loroco y la salsa tomate con loroco, donde dichos productos son preferidos por el público entre 26 a 35 años, que buscan mantener un estilo de vida saludable sin perder el sabor en sus comidas. Además, es importante destacar que a través de la investigación se determinó que Súper Selectos es el supermercado preferido por los salvadoreños donde les gustaría encontrar el producto, ya que actualmente solo se encuentran en Walmart. Además, es importante destacar que la marca ha sido conocida en su mayoría por las diferentes participaciones que han tenido en ferias nacionales e internacionales, así como también gracias a la recomendación de alguien más. Todas las valoraciones que se obtuvieron con la investigación, permitieron crear las diferentes propuestas para el mejoramiento de los activos digitales de la empresa. Propuestas como la redefinición de la identidad corporativa, la reactivación de las diferentes plataformas que utiliza actualmente y la generación de contenido relevante, promocional y fidelización de clientes; son los tres ejes esenciales que permitieron crear las diferentes tácticas de implementación para el mejoramiento potencial de los activos digitales de la marca

    The Use of Water in Agriculture in Mexico and Its Sustainable Management: A Bibliometric Review

    Get PDF
    The development of agricultural activity in Mexico is generating environmental externalities that could compromise its future. One of the principal challenges facing the Mexican agricultural sector is to find a way to continue growing without jeopardising the availability and quality of its water resources. The objective of this article is to analyse the dynamics of the research on the use of water in agriculture in Mexico and its sustainable management. To do this, a review and a bibliometric analysis have been carried out on a sample of 1490 articles. The results show that the research has focused on the pollution of water bodies, climate change, the quality of water, the application of technology in order to make water use more efficient, biodiversity, erosion, agronomic practices that reduce water consumption, underground water sources, and conservation agriculture. Although research focusing on sustainability is still in its infancy, it has become a priority field. A gap in the research has been detected in terms of the economic and social dimensions of sustainability. There is also a lack of holistic studies that include all three of the pillars of sustainability (environmental, economic, and social)
    corecore