90 research outputs found

    Symmetry-preserving matchings

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    In the literature, the matchings between spacetimes have been most of the times implicitly assumed to preserve some of the symmetries of the problem involved. But no definition for this kind of matching was given until recently. Loosely speaking, the matching hypersurface is restricted to be tangent to the orbits of a desired local group of symmetries admitted at both sides of the matching and thus admitted by the whole matched spacetime. This general definition is shown to lead to conditions on the properties of the preserved groups. First, the algebraic type of the preserved group must be kept at both sides of the matching hypersurface. Secondly, the orthogonal transivity of two-dimensional conformal (in particular isometry) groups is shown to be preserved (in a way made precise below) on the matching hypersurface. This result has in particular direct implications on the studies of axially symmetric isolated bodies in equilibrium in General Relativity, by making up the first condition that determines the suitability of convective interiors to be matched to vacuum exteriors. The definition and most of the results presented in this paper do not depend on the dimension of the manifolds involved nor the signature of the metric, and their applicability to other situations and other higher dimensional theories is manifest.Comment: LaTeX, 19 page

    Fuzzy logic application for improving speed control and captured energy using the wind speed information for wind turbines

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    This paper describes a fuzzy logic application for improving the variable speed and blade pitch wind turbine performance. The simulated model is going to be implemented using a programmable logic controller as the fuzzy controller designed. The used fuzzy controller as well as improving transition between power optimization and power limitation of the wind turbine at rated wind speed, it also permits to improve the captured wind energy at high wind speed working conditions using wind speed as input controller

    Mapeo de áreas regadas usando datos geoespaciales y teledetección en el municipio de Caudete de las Fuentes (Valencia)

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    Las políticas de control del uso agrícola de aguas subterráneas mediante la inspección de contadores se han demostrado caras y poco eficientes, mientras que en algunos estudios se ha obtenido resultados prometedores mediante la teledetección. El rápido progreso de las tecnologías de teledetección ha hecho posible su aplicación para la identificación de áreas regadas, y los nuevos sensores y técnicas de inteligencia artificial abren nuevas oportunidades a mejorar su eficacia y precisión. Nuestro trabajo propone una metodología de bajo coste y eficiente para detectar viña en riego a escala de parcela con el fin de mejorar la gestión colectiva de aguas subterráneas. A partir de información oficial se ha distinguido la superficie regada con técnicas de análisis de aprendizaje automático, empleando variables que condicionan el estado hídrico de la planta para la temporada de riego 2019. La metodología calcula la humedad del suelo con el método OPTRAM (OPtical TRApezoid Model) de análisis multitemporal de imágenes procedentes de plataformas satelitales. Estos datos son integrados en un SIG junto a información climática, topográfica e información propia del cultivo. Finalmente, en base a inventarios de verdad-terreno se aplica un clasificador de aprendizaje automático para estimar la superficie regada con agua procedente del acuífero. Los resultados obtenidos presentan una precisión general del 94.7%. Su evaluación aporta un error medio cuadrático de 0.163 y R-cuadrado de 0.874. La alta precisión y los bajos niveles de error obtenidos permiten validar la metodología empleada, que presenta potencial de mejora mediante una mayor alimentación del proceso de aprendizaje automático, que se aplicará en breve a otros cultivos leñosos

    Abiotic Input of Fixed Nitrogen by Bolide Impacts to Gale Crater During the Hesperian : Insights From the Mars Science Laboratory

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    We acknowledge the NASA Mars Science Laboratory Program, Centre National d'Études Spatiales, the Universidad Nacional Autónoma de México (PAPIIT IN109416, IN111619, and PAPIME PE103216), and the Consejo Nacional de Ciencia y Tecnología de México (CONACyT 220626) for their support. We thank Fred Calef for constructing Figure 4 and appreciate the interest and support received from John P. Grotzinger and Joy A. Crisp throughout the Curiosity mission. The authors are grateful to the SAM and MSL teams for successful operation of the SAM instrument and the Curiosity rover. The data used in this paper are listed in the supporting information, figures, and references. SAM Data contained in this paper are publicly available through the NASA Planetary Data System at http://pds‐geosciences.wustl.edu/missions/msl/sam.htm. We would like to express gratitude to Pierre‐Yves Meslin from the Research Institute in Astrophysics and Planetology at Toulouse, France, and five anonymous reviewers whose comments/suggestions on earlier drafts helped improve and clarify this manuscript. The authors declare no conflicts of interests.Peer reviewedPublisher PD

    Non-motor symptom burden in patients with Parkinson's disease with impulse control disorders and compulsive behaviours : results from the COPPADIS cohort

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    The study was aimed at analysing the frequency of impulse control disorders (ICDs) and compulsive behaviours (CBs) in patients with Parkinson's disease (PD) and in control subjects (CS) as well as the relationship between ICDs/CBs and motor, nonmotor features and dopaminergic treatment in PD patients. Data came from COPPADIS-2015, an observational, descriptive, nationwide (Spain) study. We used the validated Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) for ICD/CB screening. The association between demographic data and ICDs/CBs was analyzed in both groups. In PD, this relationship was evaluated using clinical features and treatment-related data. As result, 613 PD patients (mean age 62.47 ± 9.09 years, 59.87% men) and 179 CS (mean age 60.84 ± 8.33 years, 47.48% men) were included. ICDs and CBs were more frequent in PD (ICDs 12.7% vs. 1.6%, p < 0.001; CBs 7.18% vs. 1.67%, p = 0.01). PD patients had more frequent previous ICDs history, premorbid impulsive personality and antidepressant treatment (p < 0.05) compared with CS. In PD, patients with ICDs/CBs presented younger age at disease onset, more frequent history of previous ICDs and premorbid personality (p < 0.05), as well as higher comorbidity with nonmotor symptoms, including depression and poor quality of life. Treatment with dopamine agonists increased the risk of ICDs/CBs, being dose dependent (p < 0.05). As conclusions, ICDs and CBs were more frequent in patients with PD than in CS. More nonmotor symptoms were present in patients with PD who had ICDs/CBs compared with those without. Dopamine agonists have a prominent effect on ICDs/CBs, which could be influenced by dose

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

    Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

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    Contains fulltext : 172380.pdf (publisher's version ) (Open Access

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Identification and characterization of sources of resistance in Avena sativa, A. byzantina and A. strigosa germplasm against a pathotype of Puccinia coronata f.sp. avenae with virulence against the Pc94 resistance gene

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    An isolate of Puccinia coronata f.sp. avenae with virulence against the oat crown rust resistance gene Pc94 was discovered in oat fields in Córdoba, Spain. In order to identify alternative sources of resistance to this virulent isolate, a collection of 159 Avena accessions, including 107 A. sativa and 29 A. byzantina landraces and 23 commercial A. sativa and A. strigosa cultivars, was screened. Eight resistant landraces and four cultivars were selected according to macroscopic assessment to further characterize the operative defence mechanisms. Histological studies showed a range of defence mechanisms, acting alone or in combination, which impeded fungal development at different stages. Some accessions allowed reduced fungal growth before mesophyll penetration. In others, the fungus was arrested at the penetration stage by mesophyll cell wall strengthening and/or papilla deposition. Mesophyll cells of several accessions were penetrated by the fungus, but then the hypersensitive response (HR) leading to cell death hampered fungal development. In some cases cell death was very fast and colonies aborted early, whereas in other cases necrosis was observed later and associated with numerous secondary hyphae, suggesting a slow HR. Characterization of defence mechanisms will be useful for breeding programmes and for further cellular and molecular studies to unravel the bases of resistance. Commonalities with the resistance of the same oat collection to powdery mildew are discussed. © 2011 The Authors. Plant Pathology © 2011 BSPP.We gratefully acknowledge the projects AGL2007-65031/AGR and AGL2010-15936/AGR from the Spanish Ministry of Science and Innovation, PIE-200840I113 from CSIC and European Regional Development Funds for financial support.Peer Reviewe
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