365 research outputs found

    Pyramidal Fisher Motion for Multiview Gait Recognition

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    The goal of this paper is to identify individuals by analyzing their gait. Instead of using binary silhouettes as input data (as done in many previous works) we propose and evaluate the use of motion descriptors based on densely sampled short-term trajectories. We take advantage of state-of-the-art people detectors to define custom spatial configurations of the descriptors around the target person. Thus, obtaining a pyramidal representation of the gait motion. The local motion features (described by the Divergence-Curl-Shear descriptor) extracted on the different spatial areas of the person are combined into a single high-level gait descriptor by using the Fisher Vector encoding. The proposed approach, coined Pyramidal Fisher Motion, is experimentally validated on the recent `AVA Multiview Gait' dataset. The results show that this new approach achieves promising results in the problem of gait recognition.Comment: Submitted to International Conference on Pattern Recognition, ICPR, 201

    Inverse central ordering for the Newton interpolation formula

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    An inverse central ordering of the nodes is proposed for the Newton interpolation formula. This ordering may improve the stability for certain distributions of nodes. For equidistant nodes, an upper bound of the conditioning is provided. This bound is close to the bound of the conditioning in the Lagrange interpolation formula, whose conditioning is the lowest. This ordering is related to a pivoting strategy of a matrix elimination procedure called Neville elimination. The results are illustrated with examples

    AIRPA: An Architecture to Support the Execution and Maintenance of AI-Powered RPA Robots

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    Robotic Process Automation (RPA) has quickly evolved from automating simple rule-based tasks. Nowadays, RPA is required to mimic more sophisticated human tasks, thus implying its combina tion with Artificial Intelligence (AI) technology, i.e., the so-called intelli gent RPA. Putting together RPA with AI leads to a challenging scenario since (1) it involves professionals from both fields who typically have different skills and backgrounds, and (2) AI models tend to degrade over time which affects the performance of the overall solution. This paper describes the AIRPA project, which addresses these challenges by proposing a software architecture that enables (1) the abstraction of the robot development from the AI development and (2) the monitor, con trol, and maintain intelligent RPA developments to ensure its quality and performance over time. The project has been conducted in the Serv inform context, a Spanish consultancy firm, and the proposed prototype has been validated with reality settings. The initial experiences yield promising results in reducing AHT (Average Handle Time) in processes where AIRPA deployed cognitive robots, which encourages exploring the support of intelligent RPA development.Ministerio de Ciencia, Innovación y Universidades PID2019-105455GB-C31Centro para el Desarrollo Tecnológico Industrial EXP00118029/IDI-20190524Centro para el Desarrollo Tecnológico Industrial P011-19/E0

    Design strategies for optimizing holographic optical tweezers setups

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    We provide a detailed account of the construction of a system of holographic optical tweezers. While much information is available on the design, alignment and calibration of other optical trapping configurations, those based on holography are relatively poorly described. Inclusion of a spatial light modulator in the setup gives rise to particular design trade-offs and constraints, and the system benefits from specific optimization strategies, which we discuss.Comment: 16 pages, 15 figure

    HoloTrap: Interactive hologram design for multiple dynamic optical trapping

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    This work presents an application that generates real-time holograms to be displayed on a holographic optical tweezers setup; a technique that allows the manipulation of particles in the range from micrometres to nanometres. The software is written in Java, and uses random binary masks to generate the holograms. It allows customization of several parameters that are dependent on the experimental setup, such as the specific characteristics of the device displaying the hologram, or the presence of aberrations. We evaluate the software's performance and conclude that real-time interaction is achieved. We give our experimental results from manipulating 5 micron-diametre microspheres using the program.Comment: 17 pages, 6 figure

    P28 85. Análisis de la supervivencia a corto y medio plazo de la cirugía de aorta ascendente

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    ObjetivosEvaluar la mortalidad hospitalaria y la supervivencia a medio plazo de los pacientes sometidos a una cirugía de aorta ascendente y determinar cuáles son sus factores de riesgo.Material y métodosSe analizó de forma retrospectiva toda la población de pacientes sometidos a un procedimiento quirúrgico de aorta ascendente (sustitución con o sin cirugía valvular o de raíz asociada) entre enero de 2003 y diciembre de 2008. Se evaluó la mortalidad hospitalaria y la supervivencia absoluta en el seguimiento, y mediante análisis uni y multivariante se determinaron las correspondientes variables predictoras.ResultadosTrescientos sesenta y cinco pacientes fueron sometidos de forma consecutiva a algún procedimiento quirúrgico de la aorta ascendente. Edad media: 63,1 años (desviación estándar [DE] 13); n = 99 (27,1%) fueron mujeres; n = 58 (15,9%) habían sido sometidos a una cirugía previa. En 32 pacientes se sustituyó total o parcialmente el arco aórtico. EuroSCORE mediano de 11,72% (interquartile range [IQR]: 6,78-20,43). La mortalidad hospitalaria fue 7,7% (n = 28). Los predictores de mortalidad en análisis multivariante fueron: cirugía cardíaca previa (odds ratio [OR]: 3,18; p = 0,045), tabaquismo activo (OR: 5,7; p = 0,021), insuficiencia renal (OR: 3,03; p = 0,043), estado crítico preoperatorio (OR: 5,63; p = 0,005), edad (OR: 1,06; p = 0,018) y cirugía coronaria asociada (OR: 3,17; p = 0,35). La supervivencia a 1, 3 y 5 años fue 96, 94 y 92%. Sólo edad (hazard ratio [HR]: 1,08; p = 0,022) e hipertensión pulmonar grave (HR: 3,5; p = 0,026) fueron predictores independientes de mortalidad en el seguimiento.ConclusionesEn nuestra experiencia, la sustitución de la aorta ascendente demuestra una baja mortalidad hospitalaria y una adecuada supervivencia a medio plazo

    Endothelial cell-specific roles for tetrahydrobiopterin in myocardial function, cardiac hypertrophy, and response to myocardial ischemia-reperfusion injury

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    The cofactor tetrahydrobiopterin (BH4) is a critical regulator of nitric oxide synthase (NOS) function and redox signaling, with reduced BH4 implicated in multiple cardiovascular disease states. In the myocardium, augmentation of BH4 levels can impact on cardiomyocyte function, preventing hypertrophy and heart failure. However, the specific role of endothelial cell BH4 biosynthesis in the coronary circulation and its role in cardiac function and the response to ischemia has yet to be elucidated. Endothelial cell-specific Gch1 knockout mice were generated by crossing Gch1fl/fl with Tie2cre mice, generating Gch1fl/flTie2cre mice and littermate controls. GTP cyclohydrolase protein and BH4 levels were reduced in heart tissues from Gch1fl/flTie2cre mice, localized to endothelial cells, with normal cardiomyocyte BH4. Deficiency in coronary endothelial cell BH4 led to NOS uncoupling, decreased NO bioactivity, and increased superoxide and hydrogen peroxide productions in the hearts of Gch1fl/flTie2cre mice. Under physiological conditions, loss of endothelial cell-specific BH4 led to mild cardiac hypertrophy in Gch1fl/flTie2cre hearts. Endothelial cell BH4 loss was also associated with increased neuronal NOS protein, loss of endothelial NOS protein, and increased phospholamban phosphorylation at serine-17 in cardiomyocytes. Loss of cardiac endothelial cell BH4 led to coronary vascular dysfunction, reduced functional recovery, and increased myocardial infarct size following ischemia-reperfusion injury. Taken together, these studies reveal a specific role for endothelial cell Gch1/BH4 biosynthesis in cardiac function and the response to cardiac ischemia-reperfusion injury. Targeting endothelial cell Gch1 and BH4 biosynthesis may provide a novel therapeutic target for the prevention and treatment of cardiac dysfunction and ischemia-reperfusion injury. NEW & NOTEWORTHY We demonstrate a critical role for endothelial cell Gch1/BH4 biosynthesis in coronary vascular function and cardiac function. Loss of cardiac endothelial cell BH4 leads to coronary vascular dysfunction, reduced functional recovery, and increased myocardial infarct size following ischemia/reperfusion injury. Targeting endothelial cell Gch1 and BH4 biosynthesis may provide a novel therapeutic target for the prevention and treatment of cardiac dysfunction, ischemia injury, and heart failure

    Retrospective cohort analysis of Spanish national trends of coronary artery bypass grafting and percutaneous coronary intervention from 1998 to 2017

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    Introduction Spain is one of the countries with the lowest rates of revascularisation and highest ratio of percutaneous coronary intervention (PCI) to coronary artery bypass grafting (CABG). Objectives To investigate the changes and trends in the two revascularisation procedures between 1998 and 2017 in Spain. Design Retrospective cohort study. Analysis of in-hospital outcomes. Setting Minimum basic data set from the Spanish National Department of Health: mandatory database collecting information of patients who are attended in the Spanish public National Health System. Participants 603 976 patients who underwent isolated CABG or PCI in the Spanish National Health System. The study period was divided in four 5-year intervals. Patients with acute myocardial infarction on admission were excluded. Primary and secondary outcomes We investigated the volume of procedures nationwide, the changes of the risk profile of patients and in-hospital mortality of both techniques. Results We observed a 2.2-fold increase in the rate of any type of myocardial revascularisation per million inhabitants-year: 357 (1998) to 776 (2017). 93 682 (15.5%) had a coronary surgery. PCI to CABG ratio rose from 2.2 (1998-2002) to 8.1 (2013-2017). Charlson's index increased by 0.8 for CABG and 1 for PCI. The median annual volume of PCI/hospital augmented from 136 to 232, while the volume of CABG was reduced from 137 to 74. In the two decades, we detected a significant reduction of CABG in-hospital mortality (6.5% vs 2.6%, p<0.001) and a small increase in PCI (1.2% vs 1.5%, p<0.001). Risk adjusted mortality rate was reduced for both CABG (1.51 vs 0.48, p<0.001), and PCI (1.42 vs 1.05, p<0.001). Conclusion We detected a significant increase in the volume of revascularisations (particularly PCI) in Spain. Risk-adjusted in-hospital mortality was significantly reduce

    Bivariate spline interpolation with optimal approximation order

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    Let be a triangulation of some polygonal domain f c R2 and let S9 (A) denote the space of all bivariate polynomial splines of smoothness r and degree q with respect to A. We develop the first Hermite-type interpolation scheme for S9 (A), q >_ 3r + 2, whose approximation error is bounded above by Kh4+i, where h is the maximal diameter of the triangles in A, and the constant K only depends on the smallest angle of the triangulation and is independent of near-degenerate edges and nearsingular vertices. Moreover, the fundamental functions of our scheme are minimally supported and form a locally linearly independent basis for a superspline subspace of Sr, (A). This shows that the optimal approximation order can be achieved by using minimally supported splines. Our method of proof is completely different from the quasi-interpolation techniques for the study of the approximation power of bivariate splines developed in [71 and [181

    Introducing the climate change effects on Mediterranean forest ecosystems : observation, experimentation, simulation and management -

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    An increasing number of observational evidences on the biological effects of climate change is becoming available in the Mediterranean forests. Many changes have been observed in the last decades in response to this climatic change which will affect the physiology, phenology, growth, reproduction, establishment and, finally, the distribution of organisms, and therefore the structure and functioning of our forests. The management of the forested areas has to be dealt with at the landscape scale, in a planning that considers the combination of different spaces, as well as their multiple uses and the effect of the disturbances, like for example forest fire
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