3,321 research outputs found

    Cancelling Wideband Impulsive Noise by Processing the Masked Tones in Power Line Communications

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    It has been demonstrated that Power Line Communications (PLC) can interfere with some radio services. In order to avoid it, PLC standards specify not to transmit at the same frequencies where these radio services operate. These frequencies are called the masked tones. As they carry no transmitted power, the masked tones can be used to detect and cancel impulsive noise (IN), which most of times is wideband and leaks out into the whole PLC band. This research work presents a new procedure to identify and eliminate IN from PLC receivers, being able to recover the original signal samples which have been impaired by the IN pulses

    Sidewall effects on heat transfer in narrow backward facing step in transitional regime

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    In this work, we study numerically with large eddy simulation, the effects induced by the three-dimensional geometry of the channel on the flow topology that exists when the three-dimensional intrinsic instabilities appear in a backward facing step flow with low aspect ratio for Reynolds in the transitional regime (Re = 1,000–1,600), and its impact on the heat flux in the lower wall. Under the transitional regime, the three-dimensional instabilities begin to appear, but they can be masked by the flows due to the presence of the side walls. The study is carried out with two boundary conditions in the sidewalls, slip, and no-slip, to discriminate between the three-dimensionality induced by the geometry and the intrinsic three-dimensional instabilities. The results obtained are compared between the two boundary conditions, establishing what type of flow prevails and its influence on time-averaged mean Nusselt number for all Reynolds.This work was funded by Ministerio de Ciencia, Innovación y Universidades y fondos FEDER - Proyecto Retos-Colaboración RTC-2017-6137-8

    A framework to study and predict functional trait syndromes using phylogenetic and environmental data

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    Traits do not evolve in isolation but often as part of integrated trait syndromes, yet the relative contributions of environmental effects and evolutionary history on traits and their correlations are not easily resolved.In the present study, we develop a methodological framework to elucidate eco-evolutionary patterns in functional trait syndromes. We do so by separating the amount of variance and covariance related to phylogenetic heritage and environmental variables (environmental phylogenetic conservatism), only phylogenetic heritage (non-attributed phylogenetic conservatism) and only to environmental variables (evolutionarily labile environmental effects). Variance–covariance structures of trait syndromes are displayed as networks. We then use this framework to guide a newly derived imputation method based on machine learning models that predict trait values for unsampled taxa, considering environmental and phylogenetic information as well as trait covariation. TrEvol is presented as an R package providing a unified set of methodologies to study and predict multivariate trait patterns and improve our capacity to impute trait values.To illustrate its use, we leverage both simulated data and species-level traits related to hydraulics and the leaf economics spectrum, in relation to an aridity index, demonstrating that most trait correlations can be attributed to environmental phylogenetic conservatism.This conceptual framework can be employed to examine issues ranging from the evolution of trait adaptation at different phylogenetic depths to intraspecific trait variation

    A proxy for carrying capacity of Mediterranean aquaculture

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    In developing a holistic and innovative approach to determining the carrying capacity in marine finfish aquaculture, we carried out a modified Delphi exercise in which we asked industry experts to identify the factors influencing the production levels of the activity under different scenarios. We disseminated and discussed three rounds of questionnaires in sectoral roundtables and workshops with experts, culminating in the development of a simple formula that adapts production levels to the physical, ecological, social and economic conditions of the activity on the Spanish Mediterranean coast. We used this formula to approach the carrying capacity of the system. Based on the developed model and its theoretical application, we estimated the carrying capacity for floating cages on the Spanish Mediterranean coast at 119,404 t—about 1.2 times the current production level of 96,440 t. We therefore concluded that, subject to the execution of an in-situ validation of the model, the production level of floating nurseries on the Spanish Mediterranean coast could be increased by up to 33.5%.KT-G was funded by a postdoctoral tenure program Juan de la Cierva Formación (FJCI-2014-20100) and Juan de la Cierva Incorporación (IJCI-2017-34174) funded by Spanish National Research Agency. This study was funded by the Projects “Environmental Innovation Measures for the Development and Establishment of Protocols for Carrying Capacity for Aquaculture Sustainability (MIMECCA)”; “Marine Aquaculture Carrying Capacity Applied Models (MACCAM)”; “GLObal change Resilience in Aquaculture-2 (GLORiA2),” supported by the Biodiversity Foundation of the Spanish Ministry for the Ecological Transition and Demographic Challenge, through the Pleamar Program and co-financed by the European Maritime and Fisheries Fund (EMFF). It is also part of the LIFE IP INTEMARES Project “Integrated, innovative and participatory management of the Natura 2000 Network in the Spanish marine environment”. This study forms part of the ThinkInAzul programme and was supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17·I1) and by Generalitat Valenciana (THINKINAZUL/2021/044-TOWARDS)

    Funcionalidad tecnológica del sistema de producción de una granja lechera en la empresa ganadera Valle del Perú

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    Se realizó un diagnóstico con el propósito de determinar la funcionalidad tecnológica y la sustentabilidad de la Granja Zenea de la Empresa Ganadera en la región occidental de Cuba. Se aplicó la metodología de Diagnóstico Rural Rápido (DRP). Las fuentes de información secundarias utilizadas fueron: registros de producción de leche, índices reproductivos y económicos a nivel de granja. La caracterización se efectuó a través de indicadores descriptivos que se relacionan con los componentes del sistema de producción, el productor y sus características, la infraestructura técnico-productiva y aspectos organizacionales. La funcionalidad tecnológica se realizó a partir de variables que se relacionan con los procesos tecnológicos que se identifican con el sistema de producción. Se realizó una jerarquización de problemas y se definieron los principales indicadores que deben servir para medir la sostenibilidad en la propuesta de transformación del sistema. Se analizaron estadísticamente algunas variables productivas y su comportamiento, para los efectos de vaquería, año y bimestre, bajo un modelo lineal de efectos fijos con interacción. El sistema estudiado se caracteriza por ser un sistema de producción típico de la región, con mediano nivel tecnológico y problemas que en su conjunto repercuten en los bajos niveles de producción, ingresos y rentabilidad. Se identificaron a partir de la caracterización realizada los problemas, lo que permitió laborar una estrategia general y específica, así como las principales acciones de carácter técnico-organizativo que se deben tomar para lograr a través del tiempo la sostenibilidad y el mejoramiento de la productividad del sistema estudiado.Palabras clave: diagnóstico agroecológico, funcionalidad tecnológica, producc

    Funcionalidad tecnologica del sistema de producción de una granja lechera en la empresa ganadera Valle del Perú

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    Se realizó un diagnóstico con el propósito de determinar la funcionalidad tecnológica y la sustentabilidad de la Granja Zenea de la Empresa Ganadera en la región occidental de Cuba. Se aplicó la metodología de Diagnóstico Rural Rápido (DRP). Las fuentes de información secundarias utilizadas fueron: registros de producción de leche, indices reproductivos y económicos a nivel de granja. La caracterización se efectuó a través de indicadores descriptivos que se relacionan con los componentes del sistema de producción, el productor y sus características, la infraestructura técnico-productiva y aspectos organizacionales. La funcionalidad tecnológica se realizó a partir de variables que se relacionan con los procesos tecnológicos que se identifican con el sistema de producción. Se realizó una jerarquización de problemas y se definieron los principales indicadores que deben servir para medir la sostenibilidad en la propuesta de transformación del sistema. Se analizaron estadísticamente algunas variables productivas y su comportamiento, para los efectos de vaquería, año y bimestre, bajo un modelo lineal de efectos fijos con interacción. El sistema estudiado se caracteriza por ser un sistema de producción típico de la región, con mediano nivel tecnológico y problemas que en su conjunto repercuten en los bajos niveles de producción, ingresos y rentabilidad. Se identificaron a partir de la caracterización realizada los problemas, lo que permitió laborar una estrategia general y específica, así como las principales acciones de carácter técnico-organizativo que se deben tomar para lograr a través del tiempo la sostenibilidad y el mejoramiento de la productividad del sistema estudiado

    The TGF-β Pathway: A Pharmacological Target in Hepatocellular Carcinoma?

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    Transforming Growth Factor-beta (TGF-β) superfamily members are essential for tissue homeostasis and consequently, dysregulation of their signaling pathways contributes to the development of human diseases. In the liver, TGF-β signaling participates in all the stages of disease progression from initial liver injury to hepatocellular carcinoma (HCC). During liver carcinogenesis, TGF-β plays a dual role on the malignant cell, behaving as a suppressor factor at early stages, but contributing to later tumor progression once cells escape from its cytostatic effects. Moreover, TGF-β can modulate the response of the cells forming the tumor microenvironment that may also contribute to HCC progression, and drive immune evasion of cancer cells. Thus, targeting the TGF-β pathway may constitute an effective therapeutic option for HCC treatment. However, it is crucial to identify biomarkers that allow to predict the response of the tumors and appropriately select the patients that could benefit from TGF-β inhibitory therapies. Here we review the functions of TGF-β on HCC malignant and tumor microenvironment cells, and the current strategies targeting TGF-β signaling for cancer therapy. We also summarize the clinical impact of TGF-β inhibitors in HCC patients and provide a perspective on its future use alone or in combinatorial strategies for HCC treatment

    Atmospheric pressure gas chromatography-time-of-flight-mass spectrometry (APGC-ToF-MS) for the determination of regulated and emerging contaminants in aqueous samples after stir bar sorptive extraction (SBSE)

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    This work presents the development, optimization and validation of a multi-residue method for the simultaneous determination of 102 contaminants, including fragrances, UV filters, repellents, endocrine disruptors, biocides, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and several types of pesticides in aqueous matrices. Water samples were processed using stir bar sorptive extraction (SBSE) after the optimization of several parameters: agitation time, ionic strength, presence of organic modifiers, pH, and volume of the derivatizing agent. Target compounds were extracted from the bars by liquid desorption (LD). Separation, identification and quantification of analytes were carried out by gas chromatography (GC) coupled to time-of-flight (ToF-MS) mass spectrometry. A new ionization source, atmospheric pressure gas chromatography (APGC), was tested. The optimized protocol showed acceptable recovery percentages (50–100%) and limits of detection below 1 ng L−1 for most of the compounds. Occurrence of 21 out of 102 analytes was confirmed in several environmental aquatic matrices, including seawater, sewage effluent, river water and groundwater. Non-target compounds such as organophosphorus flame retardants were also identified in real samples by accurate mass measurement of their molecular ions using GC-APGC–ToF-MS. To the best of our knowledge, this is the first time that this technique has been applied for the analysis of contaminants in aquatic systems. By employing lower energy than the more widely used electron impact ionization (EI), AGPC provides significant advantages over EI for those substances very susceptible to high fragmentation (e.g., fragrances, pyrethroids)
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