365 research outputs found

    Monomial discrete valuations in k[[X]]

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    Let v be a rank m discrete valuation of k[[X1,...,Xn]] with dimension n-m. We prove that there exists an inmediate extension L of K where the valuation is monomial. Therefore we compute explicitly the residue field of the valuation

    Characterization of Leachate from Different Landfills Sites of Morocco and Spain: A Comparative Study

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    The socio-economic activities in Morocco and Spain as well as all the other countries around the world involving population growth and changes in consumption behavior have generated a substantial and important solid waste production. The decomposition of waste by microorganisms in landfills generates soluble compounds, which under the leaching action and water infiltration meteorites come to mix together forming “leachate juices”. Its composition varies widely depending on the age of the landfill and the type of waste it contains. The latter usually contains dissolved and suspended material. This study aims to characterize the physicochemical properties and evaluate the mineral and organic compounds of different leachates. It is worthy to note that this physicochemical characterization is arbitrary because those landfills willsoon be equipped with an elimination center and treatment. The following objectives of this paper have been set for this work; on one hand, to determine the qualitative characteristics aspects of leachates that are essential for characterizing the pollutant load and, thus, estimating the risks that these leachates pose to the water quality of the surrounding groundwater. On the other hand, it aims to propose a cost effective and efficient leachates treatment processes and also serves as a stepping stone reference for future leachate research. The desired process aims at obtaining a very significant reduction in the organic load of the leachate and thus could be replicated in other current and future releases. To achieve this characterization, we carried out a series of leachate sampling from different regions in Morocco (Casablanca and Marrakech) and Spain (ULEA and Orihuela). This sampling was carried out for the purpose of making a comparison between the evolutions of their qualities, and it also allows us to know the statue of those landfills

    Experimental method for perching flapping-wing aerial robots

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    In this work, we present an experimental setup and guide to enable the perching of large flapping-wing robots. The combination of forward flight, limited payload, and flight oscillations imposes challenging conditions for localized perching. The described method details the different operations that are concurrently performed within the 4 second perching flight. We validate this experiment with a 700 g ornithopter and demonstrate the first autonomous perching flight of a flapping-wing robot on a branch. This work paves the way towards the application of flapping-wing robots for long-range missions, bird observation, manipulation, and outdoor flight.Comment: IROS 2022 Workshop: Agile Robotics: Perception, Learning, Planning, and Control, 202

    How ornithopters can perch autonomously on a branch

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    Flapping wings are a bio-inspired method to produce lift and thrust in aerial robots, leading to quiet and efficient motion. The advantages of this technology are safety and maneuverability, and physical interaction with the environment, humans, and animals. However, to enable substantial applications, these robots must perch and land. Despite recent progress in the perching field, flapping-wing vehicles, or ornithopters, are to this day unable to stop their flight on a branch. In this paper, we present a novel method that defines a process to reliably and autonomously land an ornithopter on a branch. This method describes the joint operation of a flapping-flight controller, a close-range correction system and a passive claw appendage. Flight is handled by a triple pitch-yaw-altitude controller and integrated body electronics, permitting perching at 3 m/s. The close-range correction system, with fast optical branch sensing compensates for position misalignment when landing. This is complemented by a passive bistable claw design can lock and hold 2 Nm of torque, grasp within 25 ms and can re-open thanks to an integrated tendon actuation. The perching method is supplemented by a four-step experimental development process which optimizes for a successful design. We validate this method with a 700 g ornithopter and demonstrate the first autonomous perching flight of a flapping-wing robot on a branch, a result replicated with a second robot. This work paves the way towards the application of flapping-wing robots for long-range missions, bird observation, manipulation, and outdoor flight

    CONCENTRACIÓN, DISTRIBUCIÓN Y PROCEDENCIA DE METALES Y METALOIDES EN SUELOS BAJO DIFERENTES SISTEMAS DE CULTIVO

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    La contaminación de suelos agrícolas por metales y metaloides se podría llegar a producir si se llevan a cabo malas prácticas de manejo, con los consecuentes riesgos si estos elementos fueran absorbidos por los cultivos y acumulados en las partes comestibles de los mismos. El objetivo de este estudio fue tanto evaluar la influencia de cuatro sistemas de cultivo (cereales, frutales, cítricos y hortícolas) en la acumulación y especiación de metales y metaloides en suelos, como identificar la procedencia de cada metal en cada uno de los sistemas de cultivo evaluados. Para lograr estos objetivos, se tomaron 40 muestras en suelo cultivado con cereales, frutales, cítricos y hortícolas, así como 15 muestras de suelo de zonas naturales usadas como control. Se analizaron las concentraciones totales de Cd, Co, Cr, Cu, Cu, Fe, Mn, Ni, Pb, Zn y As así como su especiación química, con los datos obtenidos se realizó un análisis multivariable para identificar el origen de los mismos. Los resultados mostraron que los suelos cultivados con cítricos y hortícolas estaban enriquecidos con Pb y Cd, los cultivados con cereales con Pb y los cultivados con frutales con Zn, destacando que todos los cultivos estaban enriquecidos con Cu, especialmente los suelos cultivados con cítricos. Atendiendo a los resultados de la especificación química, los suelos de cereales tienen un mayor riesgo debido a la alta movilidad de Cd, mientras que en los cultivos hortícolas el mayor riesgo fue causado por la movilidad de Pb. Los resultados del análisis multivariable mostraron que Pb, Cu y Cd en los suelos cultivados con cereales tenían origen antrópico, mientras que el resto de metales tenía un origen principalmente litológico. En el caso de los suelos cultivados con cítricos, los niveles de Cd, Pb, Zn y Cu tenían un origen antropogénico, y el resto geogénico. En el caso de los suelos cultivados con cítricos, As, Pb, Zn, Cu, Mn y Cd tenían un origen antropogénico mientras que Fe y Cr tenían un origen geogénico.  Finalmente, en los suelos cultivados con hortícolas, las concentraciones de Cu, Mn, Pb, and Zn tendrían un origen antropogénico mientras que el resto tendrían un origen geogénico. Por lo tanto, se puede concluir que la producción agrícola intensa enriquece los suelos por metales pesados de acuerdo con el sistema de cultivo usado, siendo la producción de cítricos donde se encontró el mayor enriquecimiento

    High Prevalence of Systemic Autoimmune Diseases in Patients with Menière's Disease

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    BACKGROUND: Autoimmunity appears to be associated with the pathophysiology of Meniere's disease (MD), an inner ear disorder characterized by episodes of vertigo associated with hearing loss and tinnitus. However, the prevalence of autoimmune diseases (AD) in patients with MD has not been studied in individuals with uni or bilateral sensorineural hearing loss (SNHL). METHODS AND FINDINGS: We estimated the prevalence of AD in 690 outpatients with MD with uni or bilateral SNHL from otoneurology clinics at six tertiary referral hospitals by using clinica criteria and an immune panel (lymphocyte populations, antinuclear antibodies, C3, C4 and proinflammatory cytokines TNFα, INFγ). The observed prevalence of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and ankylosing spondylitis (AS) was higher than expected for the general population (1.39 for RA, 0.87 for SLE and 0.70 for AS, respectively). Systemic AD were more frequently observed in patients with MD and diagnostic criteria for migraine than cases with MD and tension-type headache (p = 0.007). There were clinical differences between patients with uni or bilateral SNHL, but no differences were found in the immune profile. Multiple linear regression showed that changes in lymphocytes subpopulations were associated with hearing loss and persistence of vertigo, suggesting a role for the immune response in MD. CONCLUSIONS: Despite some limitations, MD displays an elevated prevalence of systemic AD such as RA, SLE and AS. This finding, which suggests an autoimmune background in a subset of patients with MD, has important implications for the treatment of MD

    Blood-biomarkers and devices for atrial fibrillation screening : Lessons learned from the AFRICAT (Atrial Fibrillation Research In CATalonia) study

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    AFRICAT is a prospective cohort study intending to develop an atrial fibrillation (AF) screening program through the combination of blood markers, rhythm detection devices, and long-term monitoring in our community. In particular, we aimed to validate the use of NT-proBNP, and identify new blood biomarkers associated with AF. Also, we aimed to compare AF detection using various wearables and long-term Holter monitoring. 359 subjects aged 65-75 years with hypertension and diabetes were included in two phases: Phase I (n = 100) and Phase II (n = 259). AF diagnosis was performed by baseline 12-lead ECG, 4 weeks of Holter monitoring (Nuubo TM), and/or medical history. An aptamer array including 1310 proteins was measured in the blood of 26 patients. Candidates were selected according to p-value, logFC and biological function to be tested in verification and validation phases. Several screening devices were tested and compared: AliveCor, Watch BP, MyDiagnostick and Fibricheck. AF was present in 34 subjects (9.47%). The aptamer array revealed 41 proteins with differential expression in AF individuals. TIMP-2 and ST-2 were the most promising candidates in the verification analysis, but none of them was further validated. NT-proBNP (log-transformed) (OR = 1.934; p<0.001) was the only independent biomarker to detect AF in the whole cohort. Compared to an ECG, WatchBP had the highest sensitivity (84.6%) and AUC (0.895 [0.780-1]), while MyDiagnostick showed the highest specificity (97.10%). The inclusion and monitoring of a cohort of primary care patients for AF detection, together with the testing of biomarkers and screening devices provided useful lessons about AF screening in our community. An AF screening strategy using rhythm detection devices and short monitoring periods among high-risk patients with high NT-proBNP levels could be feasible

    A larger brown fat volume and lower radiodensity are related to a greater cardiometabolic risk, especially in young men

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    Objectives: Brown adipose tissue (BAT) is important in the maintenance of cardiometabolic health in rodents. Recent reports appear to suggest the same in humans, although if this is true remains elusive partly because of the methodological bias that affected previous research. This cross-sectional work reports the relationships of cold-induced BAT volume, activity (peak standardized uptake, SUVpeak), and mean radiodensity (an inverse proxy of the triacylglycerols content) with the cardiometabolic and inflammatory profile of 131 young adults, and how these relationships are influenced by sex and body weight.Design: This is a cross-sectional study.Methods: Subjects underwent personalized cold exposure for 2 h to activate BAT, followed by static F-18-fluorodeoxyglucose PET-CT scanning to determine BAT variables. Information on cardiometabolic risk (CMR) and inflammatory markers was gathered, and a CMR score and fatty liver index (FLI) were calculated.Results: In men, BAT volume was positively related to homocysteine and liver damage markers concentrations (independently of BMI and seasonality) and the FLI (all P 0.05).Conclusions: A larger BAT volume and a lower BAT mean radiodensity are related to a higher CMR, especially in young men, which may support that BAT acts as a compensatory organ in states of metabolic disruption.</p

    Effect of sex in systemic psoriasis therapy: Differences in prescription, effectiveness and safety in the BIOBADADERM prospective cohort

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    The effect of sex on systemic therapy for psoriasis has not been well studied. The aim of this study was to analyse a large multicentre Spanish cohort of 2,881 patients with psoriasis (58.3% males), followed from January 2008 to November 2018, to determine whether sex influences prescription, effectiveness of therapy, and the risk of adverse events. The results show that women are more likely than men to be pre-scribed biologics. There were no differences between men and women in effectiveness of therapy, measur-ed in terms of drug survival. Women were more likely to develop adverse events, but the difference in risk was small and does not justify different management. Study limitations include residual confounding and the use of drug survival as a proxy for effectiveness.The BIOBADADERM project is promoted by the Fundación Piel Sana Academia Española de Dermatología y Venereología, which receives financial support from the Spanish Medicines and Health Products Agency (Agencia Española de Medicamentos y Productos Sanitarios) and from pharmaceutical companies (Abbott/Abbvie, Pfizer, MSD, Novartis, Lilly, Janssen and Almirall)

    Ciencias de la Biología y Agronomía

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    Este volumen I contiene 17 capítulos arbitrados que se ocupan de estos asuntos en Tópicos Selectos de Ciencias de la Biología y Agronomía, elegidos de entre las contribuciones, reunimos algunos investigadores y estudiantes. Se presenta un Estudio Comparativo de los Recursos Hidrológico-Forestales de la Microcuenca de la Laguna de Epatlan, Pue. (1993 a 2014); la Situación Actual de la Mancha de Asfalto en Maíz (Zea mays L.) en los Municipios de Jiquipilas y Ocozocoautla, Chiapas, México; las poblaciones sobresalientes de maíz de la raza Zapalote Chico, en la Región Istmeña de Oaxaca; Se indica el índice de área foliar de cultivo de Chile Poblano mediante dos métodos en condiciones protegidas; Esquivel, Urzúa y Ramírez exploran el efecto de la biofertilización con Azospirillum en el crecimiento y producción de Jitomate; esbozan su artículo sobre la determinación del nivel de Heterosis en híbridos de Maíz para la Comarca Lagunera; una investigación sobre la estabilización de semilla de Solanum lycopersicum durante el almacenamiento y estimulación de la germinación; acotan sobre el CTAB como una nueva opción para la detección de Huanglongbing en cítricos, plantean su evaluación sobre el aluminio y cómo afecta la vida de florero de Heliconia psittacorum; indican sobre el impacto del H-564C, como un híbrido de maíz con alta calidad de proteina para el trópico húmedo de México; presetan su investigación sobre la producción de Piña Cayena Lisa y MD2 (Ananas comosus L.) en condiciones de Loma Bonita, en Oaxaca; acotan sobre el efecto de coberteras como control biológico por conservación contra áfidos en Nogal Pecanero; esbozan sobre la caracterización de cuatro genotipos de Frijol Negro en Martínez de la Torre, Veracruz, México; presentan una caracterización hidroecológica de la microcuenca de Arroyo Prieto, Yuriría, Gto., y alternativas para su restauración ambiental; presentan su investigación sobre el efecto del hongo Beauveria bassiana sobre solubilización de fosfatos y la disponibilidad de fósforo en el suelo; plantean su investigación sobre la Germinación y regeneración in vitro de Epidendrum falcatum LINDL; esbozan su artículo sobre genotipos de frijol negro y su tolerancia a sequía terminal en Veracruz, México
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