709 research outputs found

    Uniqueness of dynamical zeta functions and symmetric products

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    A characterization of dynamically defined zeta functions is presented. It comprises a list of axioms, natural extension of the one which characterizes topological degree, and a uniqueness theorem. Lefschetz zeta function is the main (and proved unique) example of such zeta functions. Another interpretation of this function arises from the notion of symmetric product from which some corollaries and applications are obtained

    Exploring differences between phonetic classes in Sleep Apnoea Syndrome Patients using automatic speech processing techniques

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    This work is part of an on-going collaborative project between the medical and signal processing communities to promote new research efforts on automatic OSA (Obstructive Apnea Syndrome) diagnosis. In this paper, we explore the differences noted in phonetic classes (interphoneme) across groups (control/apnoea) and analyze their utility for OSA detectio

    Supernumerary Formation of Olfactory Glomeruli Induced by Chronic Odorant Exposure: A Constructivist Expression of Neural Plasticity

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    It is accepted that sensory experience instructs the remodelling of neuronal circuits during postnatal development, after their specification has occurred. The story is less clear with regard to the role of experience during the initial formation of neuronal circuits, whether prenatal or postnatal, since this process is now supposed to be primarily influenced by genetic determinants and spontaneous neuronal firing. Here we evaluated this last issue by examining the effect that postnatal chronic exposure to cognate odorants has on the formation of I7 and M72 glomeruli, iterated olfactory circuits that are formed before and after birth, respectively. We took advantage of double knock-in mice whose I7 and M72 primary afferents express green fluorescent protein and β-galactosidase, correspondingly. Our results revealed that postnatal odorant chronic exposure led to the formation of permanent supernumerary I7 and M72 glomeruli in a dose and time dependent manner. Glomeruli in exposed mice were formed within the same regions of olfactory bulb and occupy small space volumes compared to the corresponding single circuits in non-exposed mice. We suggest that local reorganization of the primary afferents could participate in the process of formation of supernumerary glomeruli. Overall, our results support that sensory experience indeed instructs the permanent formation of specific glomeruli in the mouse olfactory bulb by means of constructivist processes

    Assessment of severe apnoea through voice analysis, automatic speech, and speaker recognition techniques

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    The electronic version of this article is the complete one and can be found online at: http://asp.eurasipjournals.com/content/2009/1/982531This study is part of an ongoing collaborative effort between the medical and the signal processing communities to promote research on applying standard Automatic Speech Recognition (ASR) techniques for the automatic diagnosis of patients with severe obstructive sleep apnoea (OSA). Early detection of severe apnoea cases is important so that patients can receive early treatment. Effective ASR-based detection could dramatically cut medical testing time. Working with a carefully designed speech database of healthy and apnoea subjects, we describe an acoustic search for distinctive apnoea voice characteristics. We also study abnormal nasalization in OSA patients by modelling vowels in nasal and nonnasal phonetic contexts using Gaussian Mixture Model (GMM) pattern recognition on speech spectra. Finally, we present experimental findings regarding the discriminative power of GMMs applied to severe apnoea detection. We have achieved an 81% correct classification rate, which is very promising and underpins the interest in this line of inquiry.The activities described in this paper were funded by the Spanish Ministry of Science and Technology as part of the TEC2006-13170-C02-02 Project

    Severe apnoea detection using speaker recognition techniques

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    Proceedings of the International Conference on Bio-inspired Systems and Signal Processing (BIOSIGNALS 2009)The aim of this paper is to study new possibilities of using Automatic Speaker Recognition techniques (ASR) for detection of patients with severe obstructive sleep apnoea (OSA). Early detection of severe apnoea cases can be very useful to give priority to their early treatment optimizing the expensive and timeconsuming tests of current diagnosis methods based on full overnight sleep in a hospital. This work is part of an on-going collaborative project between medical and signal processing communities to promote new research efforts on automatic OSA diagnosis through speech processing technologies applied on a carefully designed speech database of healthy subjects and apnoea patients. So far, in this contribution we present and discuss several approaches of applying generative Gaussian Mixture Models (GMMs), generally used in ASR systems, to model specific acoustic properties of continuous speech signals in different linguistic contexts reflecting discriminative physiological characteristics found in OSA patients. Finally, experimental results on the discriminative power of speaker recognition techniques adapted to severe apnoea detection are presented. These results obtain a correct classification rate of 81.25%, representing a promising result underlining the interest of this research framework and opening further perspectives for improvement using more specific speech recognition technologiesThe activities described in this paper were funded by the Spanish Ministry of Science and Technology as part of the TEC2006-13170-C02-01 project

    Chiricaspi (Brunfelsia grandiflora, Solanaceae), a pharmacologically promising plant

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    El objetivo de este estudio fue evaluar el conocimiento tradicional rescatado sobre el chiricaspi (Brunfelsia grandiflora s.l.), obtenido en una comunidad amazónica aislada de Canelo-Kichwa en la provincia de Pastaza (Ecuador). Este enfoque demuestra bien el valor de la conservación de la biodiversidad en una ecorregión en peligro. Los autores describen las prácticas ancestrales que siguen vigentes hoy en día. Las validaron mediante revisiones bibliográficas en megabases de datos, que presentaron la actividad y los componentes químicos. Los autores también proponen posibles vías para el desarrollo de nuevos bioproductos basados en la planta. La investigación in silico sobre el diseño de nuevos fármacos basados en los conocimientos tradicionales sobre esta especie puede producir avances significativos en áreas específicas de la natalidad, la anestesiología y la neurología.This study’s objective was to evaluate the rescued traditional knowledge about the chiricaspi (Brunfelsia grandiflora s.l.), obtained in an isolated Canelo-Kichwa Amazonian community in the Pastaza province (Ecuador). This approach demonstrates well the value of biodiversity conservation in an endangered ecoregion. The authors describe the ancestral practices that remain in force today. They validated them through bibliographic revisions in data megabases, which presented activity and chemical components. The authors also propose possible routes for the development of new bioproducts based on the plant. In silico research about new drug design based on traditional knowledge about this species can produce significant progress in specific areas of childbirth, anesthesiology, and neurology.• Gobierno de Extremadura y Fondos FEDER. Ayuda GR15080peerReviewe

    Patrimonio natural y cultural de Tepotzotlán

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    324 páginas. Especialización en Diseño, Planificación y Conservación de Paisajes y Jardines.El presente documento muestra el trabajo realizado para la intervención paisajística en pueblo de Tepotzotlán. Al ser catalogado en el programa de pueblos mágicos dada su riqueza tangible e intangible; resulta relevante su estudio a fin de rescatar y/o enaltecer algunas de las virtudes que lo resguardan. La zona de intervención se enfocó esencialmente en el polígono patrimonial del centro histórico, los caminos constituidos a lo largo de Rio Chiquito y calles aledañas que conectan los tesoros patrimoniales de la zona. Dicho estudio fue abordado principalmente por grupos de trabajo interdisciplinario, conformados por alumnos de la especialidad en Paisajes y Jardines Históricos de la UAM Azcapotzalco. Se cotejaron 5 proyectos detonadores: Centro Histórico/Atrio de los Olivos, Par vial, Rio Chiquito, Camino Real de Lluvias y Acequia Real. Durante la primera etapa, se establecieron las limitaciones y potencialidades del sitio. Se recopiló información cualitativa y cuantitativa para la formulación y ejecución de un plan maestro que regirían los parámetros y objetivos en cada proyecto. El desarrollo conceptual y anteproyecto para cada zona de intervención, se reflejó en la segunda etapa de este proceso. Paralelamente, la elaboración de la propuesta de vegetación, las fichas de cada especie vegetal y la preparación de catálogos de paisaje, complementan el carácter de este trabajo. El proyecto realizado en Tepotzotlán: “Patrimonio Natural y Cultural De Tepotzotlán”, emerge, como el título del trabajo indica: desde la visión del rescate patrimonial, constituido por elementos materiales y naturales relevantes para la población local y todos sus visitantes. La última etapa comprende la puesta en marcha del proyecto ejecutivo, donde se plasmaron los detalles que dan cuerpo a cada elemento de las propuestas de diseño, la información necesaria para su construcción y la síntesis de toda la documentación consultada y elaborada, como sostén de diseño. En las siguientes páginas y capítulos, se explicará de manera extensa y particular: la metodología planteada y utilizada en el abordaje de cada proyecto. En general, se podrá observar la construcción de un trabajo paisajístico integral, llevado a cabo a lo largo de un año de esfuerzo y dedicación, vertidos en la presente tesis.Consejo Nacional de Ciencia y Tecnología (México)

    Light Reflection by Cuticles of Chrysina Jewel Scarabs: Optical Measurements, Morphology Characterization, and Theoretical Modeling

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    Cuticles of some Chrysina scarabs are characterized by flat, graded, and twisted structures of nanosized chitin fibrils. As inferred from SEM images, each species has its own spatial period or pitch P which is dependent on the depth z through the cuticle. From Berreman’s formalism, taking into account the corresponding P(z) dependence, we evaluate reflection spectra of C. aurigans and C. chrysargyrea scarabs. The spectra display the main spectral features observed in the measured ones when small sections of the cuticles are illuminated with non-polarized light, for wavelengths between 300 and 1100 nm. By considering these twisted structures as 1D photonic crystals, an approach is developed to show how the broad band characterizing the reflection spectra arises from a narrow intrinsic photonic band width, whose spectral position moves through visible and near infrared wavelengths. The role of the epicuticle that covers the twisted structures is analyzed in terms of a waxy layer acting as an anti-reflecting coating that also shows low levels of light scattering.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencia e Ingeniería de Materiales (CICIMA)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de FísicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de QuímicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC

    Enhanced Artificial Enzyme Activities on the Reconstructed Sawtoothlike Nanofacets of Pure and Pr-Doped Ceria Nanocubes

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    In this work, a simple one-step thermal oxidation process was established to achieve a significant surface increase in {110} and {111} nanofacets on well-defined, pure and Pr-doped, ceria nanocubes. More importantly, without changing most of the bulk properties, this treatment leads to a remarkable boost of their enzymatic activities: from the oxidant (oxidase-like) to antioxidant (hydroxyl radical scavenging) as well as the paraoxon degradation (phosphatase-like) activities. Such performance improvement might be due to the thermally generated sawtoothlike {111} nanofacets and defects, which facilitate the oxygen mobility and the formation of oxygen vacancies on the surface. Finally, possible mechanisms of nanoceria as artificial enzymes have been proposed in this manuscript. Considering the potential application of ceria as artificial enzymes, this thermal treatment may enable the future design of highly efficient nanozymes without changing the bulk composition.This work has been supported by the Ministry of Science, Innovation and Universities of Spain with Reference Numbers of ENE2017-82451-C3-2-R, MAT2016-81118-P and MAT2017-87579-R. The research projects funded by the Natural Science Foundation of Shandong Province (Grant ZR2017LB028), Key R&D Program of Shandong Province (Grant 2018GSF118032), and Fundamental Research Funds for the Central Universities (Grant 18CX02125A) in China are also acknowledged. TEM/STEM data were obtained at DMEUCA node of the Spanish Unique Scientific and Technological Infrastructure (ICTS) of Electron Microscopy of Materials ELECMIM. M. Tinoco thanks the FPU Scholarship Program (Grant AP2010-3737) from Ministry of Education of Spain. H. Pan is grateful for financial support (Grant 201406140130) from the Chinese Scholarship Council to accomplish her Ph.D. study at the University of Cadiz (Spain). J. M. Gonzalez, G. Blanco, and X. Chen are also grateful for the financial support from the joint project (Proyectos Integradores, Grant PI20201) in IMEYMAT of the University of Cadiz
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