410 research outputs found

    Conditional maximum likelihood timing recovery: estimators and bounds

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    This paper is concerned with the derivation of new estimators and performance bounds for the problem of timing estimation of (linearly) digitally modulated signals. The conditional maximum likelihood (CML) method is adopted, in contrast to the classical low-SNR unconditional ML (UML) formulation that is systematically applied in the literature for the derivation of non-data-aided (NDA) timing-error-detectors (TEDs). A new CML TED is derived and proved to be self-noise free, in contrast to the conventional low-SNR-UML TED. In addition, the paper provides a derivation of the conditional Cramér–Rao Bound (CRB ), which is higher (less optimistic) than the modified CRB (MCRB) [which is only reached by decision-directed (DD) methods]. It is shown that the CRB is a lower bound on the asymptotic statistical accuracy of the set of consistent estimators that are quadratic with respect to the received signal. Although the obtained bound is not general, it applies to most NDA synchronizers proposed in the literature. A closed-form expression of the conditional CRB is obtained, and numerical results confirm that the CML TED attains the new bound for moderate to high Eg/No.Peer Reviewe

    Extrusión del componente plástico de la copa acetabular sin luxación protésica: a propósito de un caso

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    Se present a un caso de extrusión del component e plástic o (polietileno) ocurrido en el transcurso del primer me s del postoperatorio en un pacient e que había sufrido un recambio del component e acetabular. Se destaca el hecho de que cursase de forma asintomática y de que no se acompañase de luxación de la prótesis.A case of disassembly of the polyethylene component of the acetabular cup acurred in a patient one mouth after revision surgery for loosening of a screwed acetabular cup is reported. Special emphasis is made in the asyntomati c clinic and on the no association with dislocation of the femoral component

    Caveolin-1 Modulates Mechanotransduction Responses to Substrate Stiffness through Actin-Dependent Control of YAP

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    The transcriptional regulator YAP orchestrates many cellular functions, including tissue homeostasis, organ growth control, and tumorigenesis. Mechanical stimuli are a key input to YAP activity, but the mechanisms controlling this regulation remain largely uncharacterized. We show that CAV1 positively modulates the YAP mechanoresponse to substrate stiffness through actin-cytoskeleton-dependent and Hippo-kinase-independent mechanisms. RHO activity is necessary, but not sufficient, for CAV1-dependent mechanoregulation of YAP activity. Systematic quantitative interactomic studies and image-based small interfering RNA (siRNA) screens provide evidence that this actin-dependent regulation is determined by YAP interaction with the 14-3-3 protein YWHAH. Constitutive YAP activation rescued phenotypes associated with CAV1 loss, including defective extracellular matrix (ECM) remodeling. CAV1-mediated control of YAP activity was validated in vivo in a model of pancreatitis-driven acinar-to-ductal metaplasia. We propose that this CAV1-YAP mechanotransduction system controls a significant share of cell programs linked to these two pivotal regulators, with potentially broad physiological and pathological implications. Moreno-Vicente et al. report that CAV1, a key component of PM mechanosensing caveolae, mediates adaptation to ECM rigidity by modulating YAP activity through the control of actin dynamics and phosphorylation-dependent interaction of YAP with the 14-3-3-domain protein YWHAH. Cav1-dependent YAP regulation drives two pathophysiological processes: ECM remodeling and pancreatic ADM. © 2018 The Author

    Aplicación de TIG en la generación de indicadores de calidad ambiental de sistemas playa-dunas

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    Se presentan resultados parciales del subproyecto “Ecosistemas y Biodiversidad: vigilancia de espacios arenosos protegidos de Canarias y África”, incluido en el 'Programa para el desarrollo de redes tecnológicas y de aplicación de datos de teledetección en África Occidental', TELECAN (MAC/3/C181), financiado por el Programa de Cooperación Transnacional Madeira-Azores-Canarias (MAC) 2007/2013. El objetivo principal era definir, mediante el uso de imágenes de satélite, indicadores de calidad ambiental para sistemas playa-dunas, al ser éstos espacios fundamentales en el desarrollo socio-económico de estos territorios, dado su atractivo turístico. En este trabajo se presentan los resultados obtenidos para una de las áreas piloto, Maspalomas (Gran Canaria, islas Canarias). Los indicadores se obtuvieron mediante el procesado de imágenes del satélite WorldView-2, con validación, en 2013, mediante campañas marinas. Asimismo, se utilizaron imágenes de archivo, correspondientes a los años 2010, 2011 y 2012. Estos indicadores se basaron en variables relacionadas con las características físicas y biológicas de las aguas litorales y de las playas y dunas. Los resultados indican una calidad, por lo general, alta y muy alta, tanto para el medio terrestre como para el marino, con superficies dentro de estas categorías del 20,3% y 75,3% y del 26,1% y 70,6%, respectivamente.Esta es una contribución del 'Programa para el desarrollo de redes tecnológicas y de aplicación de datos de teledetección en África Occidental', TELECAN (MAC/3/C181), financiado por el Programa de Cooperación Transnacional Madeira-Azores-Canarias (MAC) 2007/2013

    Detection of bipolar disorder in the prodromal phase: A systematic review of assessment instruments

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    Background: Early detection of prodromal symptoms may contribute to improving the prognosis of patients with bipolar disorder (BD). The main objective of this systematic review is to present the different procedures for the identification of initial and relapse prodromes in these patients. Methods: PsycINFO, Web of Science and PubMed databases were searched using a predetermined strategy, until January 4, 2022. Then, by means of a regulated process, studies that used a BD prodrome detection procedure, in English-language and all ages participants were selected. Quantitative and qualitative studies were assessed using a modified version of the Newcastle-Ottawa Scale and by Critical Appraisals Skills Programme checklist, respectively. Results: Forty-five studies were selected. Of these, 26 used procedures for identifying initial prodromes (n = 8014) and 19 used procedures for detecting relapse prodromes (n = 1136). The interview was the most used method in the detection of both types of prodromes (k = 30 papers, n = 4068). It was variable in its degree of structure. Mobile applications and digital technologies are gaining importance in the detection of the relapse prodromes. Limitations: A retrospective design in most papers, small samples sizes, existence of persistent subsyndromal symptoms and difficulty to identify the end of the prodrome and the onset of the disorder. Conclusions: There is a wide variety of assessment instruments to detect prodromes in BD, among which the clinical interview is most frequently used. Future research should consider development of a brief tool to be applied in different formats to patients and family members

    Polarization Properties of the Solitons Generated in the Process of Pulse Breakup in Twisted Fiber Pumped by ns Pulses

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    Common optical fibers are randomly birefringent, and solitons formatting and traveling in them are randomly polarized. However, it is desirable to have solitons with a well-defined polarization. With pump relatively long pulses, the nonlinear effects of modulation instability (MI) and stimulated Raman scattering (SRS) are dominant at the initial stage of the process of supercontinuum (SC) generation; modulation instability results in pulse breakup and formation of short pulses that evolve finally to a bunch of solitons and dispersive waves. We do the research of the polarization of solitons formed by the pulse breakup process by the effect of modulation instability with pump pulses of nanoseconds in standard fiber (SMF-28) with circular birefringence introduced by fiber twist, and the twisted fiber mitigates the random linear birefringence. In this work, we found that polarization ellipticity of solitons is distributed randomly; nevertheless, the average polarization ellipticity is closer to the circular than the polarization ellipticity of the input pulse. In the experimental setup. 200 m of SMF-28 fiber twisted by 6 turns/m was used. We used 1 ns pulse to pump the fiber. The results showed that at circular polarization of the input pulse solitons at the fiber output have polarizations close to the circular, while in the fiber without twist, the soliton polarization was random

    Enhancing spatio-chromatic representation with more-than-three color coding for image description

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    The extraction of spatio-chromatic features from color images is usually performed independently on each color channel. Usual 3D color spaces, such as RGB, present a high inter-channel correlation for natural images. This correlation can be reduced using color-opponent representations, but the spatial structure of regions with small color differences is not fully captured in two generic Red-Green and Blue-Yellow channels. To overcome these problems, we propose new color coding that is adapted to the specific content of each image. Our proposal is based on two steps: (a) setting the number of channels to the number of distinctive colors we find in each image (avoiding the problem of channel correlation), and (b) building a channel representation that maximizes contrast differences within each color channel (avoiding the problem of low local contrast). We call this approach more-than-three color coding (MTT) to emphasize the fact that the number of channels is adapted to the image content. The higher the color complexity of an image, the more channels can be used to represent it. Here we select distinctive colors as the most predominant in the image, which we call color pivots, and we build the new color coding strategy using these color pivots as a basis. To evaluate the proposed approach, we measure the efficiency in an image categorization task. We show how a generic descriptor improves performance at the description level when applied to the MTT coding

    Proyecto piloto de Aprendizaje Servicio Universidad de Barcelona y CiberCaixa hospitalaria

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    La CiberCaixa hospitalaria es un recurso dirigido a niños, niñas, jóvenes hospitalizados y familias para reducir las repercusiones emocionales y sociales de la hospitalización y contribuir al proceso de mejora de la humanización en la atención pediátrica. Se presenta un estudio piloto que consta de tres proyectos: 1) dirigido a la infancia y adolescencia, vinculado a la asignatura “Comunicación interpersonal en el ejercicio profesional” de Educación Social, 2) dirigido a las familias, vinculado a la asignatura “Infancia y familia” de Educación social y, 3) dirigido al voluntariado, vinculado a la asignatura “Axiología y valores”, de Pedagogía. Participan 21 estudiantes y 11 profesores/as de Universidad (8: Universidad de Barcelona, 2: Universidad Rovira i Virgili y 1: Universidad de Lleida); el voluntariado y los beneficiarios de la CiberCaixa hospitalaria. Se trata de dar respuesta a algunas de las necesidades detectadas a partir de la evaluación, mediante acciones de innovación para la mejora de la atención. Este proyecto comporta un aprendizaje de los estudiantes respecto a la acción socioeducativa dirigida a personas en un contexto de vulnerabilidad por motivos de salud, a la aplicación de estrategias creativas, y a una metodología basada en la flexibilidad, que debe adaptarse a la situación en todo el proceso de intervención. Por otro lado los participantes infancia, adolescencia y familia, se benefician adquiriendo nuevas habilidades desde la acción educativa y lúdica, y, el voluntariado se forma desde un modelo experiencial para la dinamización del recurso. La evaluación del proyecto permitirá su desarrollo en otros hospitales y Comunidades Autónomas.Fundació "la Caixa" . Projecte FBG-30757

    Resistance and inactivation kinetics of bacterial strains isolated from the Non-chlorinated and chlorinated effluents of a WWTP

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    The microbiological quality of water from a wastewater treatment plant that uses sodium hypochlorite as a disinfectant was assessed. Mesophilic aerobic bacteria were not removed efficiently. This fact allowed for the isolation of several bacterial strains from the effluents. Molecular identification indicated that the strains were related to Aeromonas hydrophila, Escherichia coli (three strains), Enterobacter cloacae, Kluyvera cryocrescens (three strains), Kluyvera intermedia, Citrobacter freundii (two strains), Bacillus sp. and Enterobacter sp. The first five strains, which were isolated from the non-chlorinated effluent, were used to test resistance to chlorine disinfection using three sets of variables: disinfectant concentration (8, 20 and 30 mg·L−1), contact time (0, 15 and 30 min) and water temperature (20, 25 and 30 °C). The results demonstrated that the strains have independent responses to experimental conditions and that the most efficient treatment was an 8 mg·L−1 dose of disinfectant at a temperature of 20 °C for 30 min. The other eight strains, which were isolated from the chlorinated effluent, were used to analyze inactivation kinetics using the disinfectant at a dose of 15 mg·L−1 with various retention times (0, 10, 20, 30, 60 and 90 min). The results indicated that during the inactivation process, there was no relationship between removal percentage and retention time and that the strains have no common response to the treatmentsThe work of SM-H was supported by a graduate scholarship (number 217745) that was kindly provided by CONACyT, Mexico. Some chemical reagents were generously provided by the Administration of the B.A. in Biology at UAEH, Mexico. We thank the Instituto Tecnológico de Estudios Superiores de Monterrey, Hidalgo campus, for allowing us to sample from its WWTP. The authors recognize Jose A. Rodriguez-Ávila for his comments on the procedure for analyzing inactivation kineticsS

    Petrología aplicada a la Conservación del Patrimonio

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    4 páginas. Ed. Miguel Ángel Rogerio Candelera y Cesáreo Sáiz Jiménez. Primera Reunión de la Red de Ciencia y Tecnología para la Conservación del Patrimonio (Madrid, 28-29 de junio de 2011).El grupo de Petrología Aplicada a la Conservación del Patrimonio (PAP) está constituido por investigadores del CSIC y de la UCM, que pertenecen al Instituto de Geociencias. Este instituto, creado en 2011, es una transformación del antiguo Instituto de Geología Económica (CSIC-UCM), del cual procede este grupo de investigación con más de 25 años de experiencia en la conservación del patrimonio cultural, principalmente del patrimonio arquitectónico y arqueológico realizado en piedra. El grupo participa en los estudios previos y en los realizados durante la fase de ejecución del proyecto de diferentes intervenciones encaminadas a la restauración y conservación del patrimonio (www.conservacionpatrimonio.es).Programas Geomateriales (S2009/MAT-1629) y CONSOLIDER-TCP (CSD2007-0058) y a la financiación de Grupo de Investigación de la UCM, "Alteración y Conservación de los Materiales Pétreos del Patrimonio" (ref. 921349).Peer reviewe
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