2,754 research outputs found

    Aplicación terapéutica de las células troncales adultas y embrionarias. ¿Mito o realidad?

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    Therapeutic application of the main adult and embryonic cells. Myth or reality?Aplicación terapéutica de las células troncales adultas y embrionarias. ¿Mito o realidad

    A Topologically Consistent Color Digital Image Representation by a Single Tree

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    A novel, flexible (non-unique) and topologically consistent representation called CRIT (Contour-Region incidence Tree) for a color 2D digital image I is defined here. The CRIT is a tree containing all the inter and intra connectivity information of the constant-color regions. Considering I as an abstract cell complex (ACC), its topological infor mation can be packed as a smaller (in terms of cells) ACC, whose 2-cells are the different constant-color regions of I. This modus operandi over comes the classical connectivity paradoxes of digital images by working with lower-dimensional cells such as 0-cells, 1-cells, and 2-cells. The CRIT structure allows to describe this smaller ACC in a non-redundant way. The proposed technique is based on the previous construction of the Homological Spanning Forest (HSF) structures for encoding homological information of the ACCs canonically associated to I, in terms of rooted trees connecting digital object elements without redundancyMinisterio de Ciencia e Innovación PID2019-110455GB-I00 (Par-HoT

    Caso clínico: Insuficiencia Respiratoria Aguda en el Postoperatorio de una Cesárea Urgente

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    Paciente de 31 años de edad, gestante gemelar mediante FIV con feto muerto a la 21 semana. Sin antecedentes personales ni familiares, no consumo de fármacos, no hábitos tóxicos, sin alergias medicamentosas conocidas. ASA I. Ingresa por amenaza de parto prematuro, realizándosele cesárea urgente por situación transversa del feto. Intraoperatorio sin incidentes. Recién nacido prematuro. Al segundo día del postoperatorio comienza con cuadro de abdomen agudo compatible con íleo paralítico, que empeora al día siguiente precisando laparotomía exploradora. Se aprecia peritonitis secundaria a endometritis. Se realizan lavados de cavidad abdominal y se instaura tratamiento antibiótico. Ingresa en la Unidad de Reanimación extubada, consciente, orientada, hemodinámicamente estable con bajas dosis de vasoactivos, y con función respiratoria y renal conservada. Evolución ligeramente favorable en los días posteriores permitiendo retirar vasoactivos; auscultación cardio-respiratoria normal; radiografía de tórax con pinzamiento del ángulo costodiafragmático izquierdo, sin otros hallazgos. Sin embargo, la paciente presenta una discreta taquicardia (100-105 lpm), abdomen distendido, doloroso y sin peristaltismo, leucocitosis (entorno a los 11.000 x 109 L-1) y hemoglobina de 9 mg dl-1 (resto de la analítica compatible con la normalidad). En el tercer día de estancia en la Unidad presenta un importante deterioro del estado general, con clínica de insuficiencia respiratoria aguda severa (disnea, taquipnea, uso de la musculatura accesoria, descoordinación tóraco-abdominal, obnubilación), reagudización del dolor abdominal con distensión, fiebre de 38,5ºC y descenso de la hemoglobina de un punto sin sangrado aparente por drenajes

    SORA Methodology for Multi-UAS Airframe Inspections in an Airport

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    Deploying Unmanned Aircraft Systems (UAS) in safety- and business-critical operations requires demonstrating compliance with applicable regulations and a comprehensive understanding of the residual risk associated with the UAS operation. To support these activities and enable the safe deployment of UAS into civil airspace, the European Union Aviation Safety Agency (EASA) has established a UAS regulatory framework that mandates the execution of safety risk assessment for UAS operations in order to gain authorization to carry out certain types of operations. Driven by this framework, the Joint Authorities for Rulemaking on Unmanned Systems (JARUS) released the Specific Operation Risk Assessment (SORA) methodology that guides the systematic risk assessment for UAS operations. However, existing work on SORA and its applications focuses mainly on single UAS operations, offering limited support for assuring operations conducted with multiple UAS and with autonomous features. Therefore, the work presented in this paper analyzes the application of SORA for a Multi-UAS airframe inspection (AFI) operation, that involves deploying multiple UAS with autonomous features inside an airport. We present the decision-making process of each SORA step and its application to a multiple UAS scenario. The results shows that the procedures and safety features included in the Multi-AFI operation such as workspace segmentation, the independent multi-UAS AFI crew proposed, and the mitigation actions provide confidence that the operation can be conducted safely and can receive a positive evaluation from the competent authorities. We also present our key findings from the application of SORA and discuss how it can be extended to better support multi-UAS operations.Unión Europea 10101725

    Time measurement characterization of stand-to-sit and sit-to-stand transitions by using a smartphone

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    The aim of this study is to analyze a common method to measure the acceleration of a daily activity pattern by using a smartphone. In this sense, a numerical approach is proposed to transform the relative acceleration signal, recorded by a triaxial accelerometer, into an acceleration referred to an inertial reference. The integration of this acceleration allows to determine the velocity and position with respect to an inertial reference. Two different kinematic parameters are suggested to characterize the profile of the velocity during the sit-to-stand and stand-to-sit transitions for Parkinson and control subjects. The results show that a dimensionless kinematic parameter, which is linked to the time of sit-to-stand and stand-to-sit transitions, has the potential to differentiate between Parkinson and control subjects.Peer ReviewedPreprin

    Desarrollo de un entorno de aprendizaje virtual aplicado a la búsqueda y gestión de información

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    Desarrollo de un prototipo de entorno virtual de aprendizaje orientado a la formación de estudiantes universitarios en las competencias informacionales relacionadas con la búsqueda y gestión de la información

    Parallel Image Processing Using a Pure Topological Framework

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    Image processing is a fundamental operation in many real time applications, where lots of parallelism can be extracted. Segmenting the image into different connected components is the most known operations, but there are many others like extracting the region adjacency graph (RAG) of these regions, or searching for features points, being invariant to rotations, scales, brilliant changes, etc. Most of these algorithms part from the basis of Tracing-type approaches or scan/raster methods. This fact necessarily implies a data dependence between the processing of one pixel and the previous one, which prevents using a pure parallel approach. In terms of time complexity, this means that linear order O(N) (N being the number of pixels) cannot be cut down. In this paper, we describe a novel approach based on the building of a pure Topological framework, which allows to implement fully parallel algorithms. Concerning topological analysis, a first stage is computed in parallel for every pixel, thus conveying the local neighboring conditions. Then, they are extended in a second parallel stage to the necessary global relations (e.g. to join all the pixels of a connected component). This combinatorial optimization process can be seen as the compression of the whole image to just one pixel. Using this final representation, every region can be related with the rest, which yields to pure topological construction of other image operations. Besides, complex data structures can be avoided: all the processing can be done using matrixes (with the same indexation as the original image) and element-wise operations. The time complexity order of our topological approach for a m×n pixel image is near O(log(m+n)), under the assumption that a processing element exists for each pixel. Results for a multicore processor show very good scalability until the memory bandwidth bottleneck is reached, both for bigger images and for much optimized implementations. The inherent parallelism of our approach points to the direction that even better results will be obtained in other less classical computing architectures.1Ministerio de Economía y Competitividad (España) TEC2012-37868-C04-02AEI/FEDER (UE) MTM2016-81030-PVPPI of the University of Sevill

    On the Topological Disparity Characterization of Square-Pixel Binary Image Data by a Labeled Bipartite Graph

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    Given an nD digital image I based on cubical n-xel, to fully characterize the degree of internal topological dissimilarity existing in I when using different adjacency relations (mainly, comparing 2n or 2n −1 adjacency relations) is a relevant issue in current problems of digital image processing relative to shape detection or identification. In this paper, we design and implement a new self-dual representation for a binary 2D image I, called {4, 8}-region adjacency forest of I ({4, 8}-RAF, for short), that allows a thorough analysis of the differences between the topology of the 4-regions and that of the 8-regions of I. This model can be straightforwardly obtained from the classical region adjacency tree of I and its binary complement image Ic, by a suitable region label identification. With these two labeled rooted trees, it is possible: (a) to compute Euler number of the set of foreground (resp. background) pixels with regard to 4-adjacency or 8-adjacency; (b) to identify new local and global measures and descriptors of topological dissimilarity not only for one image but also between two or more images. The parallelization of the algorithms to extract and manipulate these structures is complete, thus producing efficient and unsophisticated codes with a theoretical computing time near the logarithm of the width plus the height of an image. Some toy examples serve to explain the representation and some experiments with gray real images shows the influence of the topological dissimilarity when detecting feature regions, like those returned by the MSER (maximally stable extremal regions) method.Ministerio de Economía, Industria y Competitividad PID2019-110455GB-I00 (Par-HoT)Junta de Andalucía US-138107

    Building Hierarchical Tree Representations Using Homological-Based Tools

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    A new algorithm for computing the α-tree hierarchical repre sentation of a grey-scale digital image is presented here. The technique is based on an efficient simplified version of the Homological Spanning For est (HSF) for encoding homological and homotopy-based information of binary digital images. We create one Adjacency Tree (AdjT) for each intensity contrast in a fully parallel manner. These trees, which define a Contrast Adjacency Forest (CAdjF), are in turn transversely intercon nected by another couple of trees: the classical α-tree, and a new one complementing it, called here the α∗-tree. They convey the information of the contours and the flat regions of the original color image, plus the relations between them. Using both the α and α∗-trees, this new topolog ical representation prevents some classical drawbacks that appear when working with a single tree. An implementation in OCTAVE/MATLAB validates the correctness of our algorithm.Ministerio de Ciencia e Innovación PID2019-110455GB-I00 (Par-HoT
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