288 research outputs found
Propiedades electrónicas, mecánicas y ópticas de cristales bidimensionales de espesor atómico
Tesis doctorales inéditas. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física de la Materia Condensada. Fecha de lectura: 10/3/201
Environmental effects in mechanical properties of few-layer black phosphorus
We report on the mechanical properties of few-layer black phosphorus (BP) nanosheets, in high vacuum and as a function of time of exposure to atmospheric conditions. BP flakes with thicknesses ranging from 4 to 30 nm suspended over circular holes are characterized by nanoindentations using an atomic force microscope tip. From measurements in high vacuum an elastic modulus of 46 ± 10 GPa and breaking strength of 2.4 ± 1 GPa are estimated. Both magnitudes are independent of the thickness of the flakes. Our results show that the exposure to air has substantial influence in the mechanical response of flakes thinner than 6 nm but small effects on thicker flake
Non uniform embedding based on relevance analysis with reduced computational complexity: application to the detection of pathologies from biosignal recordings
Nonlinear analysis tools for studying and characterizing the dynamics of physiological signals have gained popularity, mainly because tracking sudden alterations of the inherent complexity of biological processes might be an indicator of altered physiological states.
Typically, in order to perform an analysis with such tools, the physiological variables that describe the biological process under study are used to reconstruct the underlying dynamics of the biological processes. For that goal, a procedure called time-delay or uniform embedding is usually employed.
Nonetheless, there is evidence of its inability for dealing with non-stationary signals, as those recorded from many physiological processes.
To handle with such a drawback, this paper evaluates the utility of non-conventional time series reconstruction procedures based on non uniform embedding, applying them to automatic pattern recognition tasks. The paper compares a state of the art non uniform approach with a novel scheme
which fuses embedding and feature selection at once, searching for better reconstructions of the dynamics of the system. Moreover, results are also compared with two classic uniform embedding techniques. Thus, the goal is comparing uniform and non uniform reconstruction techniques, including the one proposed in this work, for pattern recognition in biomedical signal processing tasks. Once the state space is reconstructed, the scheme followed characterizes with three classic nonlinear dynamic features (Largest Lyapunov Exponent, Correlation Dimension and Recurrence Period Density Entropy), while classification is carried out by means of a simple k-nn classifier. In order to test its generalization capabilities, the approach was tested with three different physiological databases (Speech Pathologies, Epilepsy and Heart Murmurs).
In terms of the accuracy obtained to automatically detect the presence of pathologies, and for the three types of biosignals analyzed, the non uniform techniques used in this work lightly outperformed the results obtained using the uniform methods, suggesting their usefulness to characterize non-stationary biomedical signals in pattern recognition applications. On the other hand, in view of the
results obtained and its low computational load, the proposed technique suggests its applicability for the
applications under study
The Close Relationship between Health Actions and Peacebuilding for the “Bien-Vivir” of Communities Affected by Armed Conflict in Colombia
Antecedentes: Este estudio tiene como objetivo presentar el diseño de una propuesta para la implementación de la Atención Integral en Salud.
Rutas en el municipio de Vista Hermosa (Meta, Colombia). Estamos intentando obtener una visión precisa y amplia.
del contexto de salud en el municipio; identificar los activos, problemas y necesidades de salud, así como los facilitadores y
barreras para la implementación de RIAS; y redactar una serie de recomendaciones para la implementación de la RIAS. Nosotros
Desarrolló el trabajo de campo con personas que habitan en el área urbana de Vista Hermosa y el asentamiento rural de Santo
Domingo.
Métodos: Desarrollamos este estudio cuasiexperimental con métodos cuantitativos y cualitativos en cuatro fases. Primero,
Identificamos la zona y trabajamos en las bases. En segundo lugar, llevamos a cabo una investigación comunitaria para caracterizar
la población; Identificar creencias, valores y necesidades de salud, así como facilitadores y barreras para acceder a la salud.
sistema; y evaluar la implementación de las RIAS para la Promoción y Mantenimiento de la Salud y las RIAS para
Salud Materno-Perinatal en el municipio. En tercer lugar, diseñamos una metodología para implementar el RIAS y
desarrollaron seis intervenciones de salud con sus respectivos entregables. Cuarto, transferimos lo construido.
conocimiento a la comunidad local, el Talento de Atención Médica y las autoridades gubernamentales en Vista Hermosa.
Resultados: Realizamos un diagnóstico de la salud de los residentes de Vista Hermosa y específicamente del estudio.
participantes con base en la RIAS de Promoción y Mantenimiento de la Salud y la RIAS de Salud Materno-Perinatal.
También elaboramos un compendio de sus valores y creencias sobre la salud, agrupados en cinco categorías: salud y
procesos de enfermedad; salud, cuerpo y territorio; cuidado de la salud; redes de atención; y barreras de acceso. Finalmente, mapeamos
la capacidad del municipio para implementar la RIAS y la dividió en tres categorías: actores clave, recursos y
facilitadores.
Discusión: Este estudio realizó aportes esenciales en tres áreas: a) las comunidades del área urbana de Vista
Hermosa y Santo Domingo; b) la implementación continua del RIAS en Vista Hermosa; y c) el campo de
investigación sobre intervenciones de salud para la consolidación de la paz. Finalmente, identificamos desafíos y limitaciones que pueden afectar la
implementación de la RIAS, así como algunas recomendaciones para abordar esta última.Background: This study aims to present the design of a proposal for implementing the Comprehensive Health Care
Routes in the municipality of Vista Hermosa (Meta, Colombia). We are trying to obtain an accurate and broad view
of the health context in the municipality; identify the health assets, problems, and needs, as well as the enablers and
barriers for implementing RIAS; and draft a series of recommendations for the implementation of the RIAS. We
developed the fieldwork with people living in the urban area of Vista Hermosa and the rural settlement of Santo
Domingo.
Methods: We developed this quasiexperimental study with quantitative and qualitative methods in four phases. First,
we identified the area and worked on the bases. Second, we conducted community-based research to characterize
the population; identify health beliefs, values, and needs, as well as enablers and barriers to accessing the health
system; and evaluate the implementation of the RIAS for Health Promotion and Maintenance and the RIAS for
Maternal-Perinatal Health in the municipality. Third, we designed a methodology for implementing the RIAS and
developed six health interventions with their respective deliverables. Fourth, we transferred the constructed
knowledge to the local community, the Health Care Talent, and the government authorities in Vista Hermosa.
Results: We made a diagnosis of the health of the residents of Vista Hermosa and specifically of the study
participants based on the RIAS for Health Promotion and Maintenance and the RIAS for Maternal-Perinatal Health.
We also developed a compendium of their values and beliefs about health, grouped into five categories: health and
disease processes; health, body, and territory; health care; care networks; and barriers to access. Finally, we mapped
the municipality's capacity to implement the RIAS and divided it into three categories: key actors, resources, and
facilitators.
Discussion: This study made essential contributions in three areas: a) the communities in the urban areas of Vista
Hermosa and Santo Domingo; b) the ongoing implementation of the RIAS in Vista Hermosa; and c) the field of
research on peacebuilding health interventions. Finally, we identified challenges and limitations that may affect the
implementation of the RIAS, as well as some recommendations to address the latter.Revista Internacional - No indexadaS
Interfaz gráfica tipo educativo para el procesamiento de Imágenes Dicom
Los avances tecnológicos han permitido generar herramientas que ayudan en un diagnóstico temprano de múltiples enfermedades con el fin de aumentar las posibilidades en las condiciones de vida de los pacientes y la esperanza de vida de los pacientes.
En este sentido una de las bondades de las tecnologías al servicio de la salud contribuye al estudio de la composición interna del cuerpo humano, las cuales se realizan a través de tomografías computarizadas y resonancias magnéticas, entre otras. Es así que, este tipo de herramientas tecnológicas posibilitan observación, comparación y la fácil percepción de las tres dimensiones del cuerpo, generando un mayor detalle en los hallazgos y por ende en un diagnóstico eficaz sobre las condiciones de salud de un paciente
A partir de lo anterior se toma como base, una herramienta que permite relacionar un formato de almacenamiento y distribución de imágenes médicas, este formato se hace llamar DICOM. Esta herramienta permite la selección de una buena parte de la imagen que contiene la información que está sujeta la imagen visual, así como la interpretación de sondeo que va más allá de una escueta imagen en escala de grises.
La presente investigación resalta la importancia de DICOM y el uso de herramientas que permitan procesar imágenes clínicas reales con el objetivo de darle al estudiante un instrumento pedagógico que le permita comprender de manera práctica las características que tienen los filtros en una imagen, las transformaciones básicas (contraste, brillo, binarización), detección de bordes y contaminación con diferentes ruidosTechnological advances have made it possible to generate tools that help in the early diagnosis of multiple diseases in order to increase the possibilities in patients' living conditions and the life expectancy of patients.
In this sense, one of the benefits of technologies at the service of health contributes to the study of the internal composition of the human body, which is carried out through computerized tomography and magnetic resonance, among others. Thus, this type of technological tools allow observation, comparison and easy perception of the three dimensions of the body, generating greater detail in the findings and therefore in an effective diagnosis on the health conditions of a patient
Based on the above, it is based on a tool that allows to relate a storage format and distribution of medical images, this format is called DICOM. This tool allows the selection of a good part of the image that contains the information that is subject to the visual image, as well as the interpretation of sounding that goes beyond a brief grayscale image.
This research highlights the importance of DICOM and the use of tools that allow the processing of real clinical images with the aim of giving the student a pedagogical instrument that allows him to understand in a practical way the characteristics that filters have in an image, the basic transformations (contrast, brightness, and binarización), edge detection and contamination with different noisesIntroducción 1
1. Planteamiento del Problema 6
2. Descripción del Problema 7
3. Formulación del Problema 8
4. Justificación 9
5. Objetivos 11
5.1 Objetivo General 11
5.2 Objetivos Específicos 11
6. Antecedentes 12
6.1 Historia del procesamiento de imágenes 12
7. Marco Teórico 18
7.1 Tomografía convencional 19
7.2 Fluoroscopia 20
7.3 Angiografía 21
7.4 Imágenes de energía dual 23
7.5 Mamografía digital 24
7.6 Tomosíntesis digital 26
7.7 Tomografía computarizada 28
7.8 Ultrasonido 30 7
7.9 PET 31
7.10 Resonancia magnética 32
7.11 Ruido 33
7.12 Técnicas de filtrado 35
7.12.1 Filtro gaussiano 36
7.12.2 Filtro average o filtro de media 37
7.12.3 Filtro laplaciano 37
7.12.4 Filtro sobel 38
7.12.5 Operador Prewitt 38
7.12.6 Algoritmo de Canny 39
7.12.7 Operador de Roberts 40
7.12.8 Filtro Gabor 40
7.12.9 Filtro Zero Cross 41
7.12.10 Filtro Unsharp 41
7.13 Imágenes DICOM 42
8. Metodología 44
8.1 Indicaciones para el uso del software 48
9. Resultados 53
10. Discusión 59
11. Conclusiones 60
12. Beneficios 61
13. Aportes 62
Referencias BibliográficasPregradoIngeniero en Biomédic
Automatic age detection in normal and pathological voice
Systems that automatically detect voice pathologies are usually trained with recordings belonging to population of all ages.
However such an approach might be inadequate because of the acoustic variations in the voice caused by the natural aging process. In top of that, elder voices present some perturbations in quality similar to those related to voice disorders, which make the detection of pathologies more troublesome. With this in mind, the study of methodologies which automatically incorporate information about speakers’ age, aiming at a simplification in the detection of voice disorders is of interest. In this respect, the present paper introduces an age detector trained with normal and pathological voice, constituting a first step towards the study of age-dependent pathology detectors. The proposed system employs sustained vowels of the Saarbrucken database from which two age groups are examinated: adults and elders. Mel frequency cepstral coefficients for characterization, and Gaussian mixture models for classification are utilized. In addition, fusion of vowels at score level is considered to improve detection performance. Results suggest that age might be effectively recognized using normal and pathological voices when using sustained vowels as acoustical material, opening up possibilities for the design of automatic age-dependent voice pathology detection systems
In-Plane Anisotropic Optical and Mechanical Properties of Two-Dimensional MoO3
Molybdenum trioxide (MoO3) in-plane anisotropy has increasingly attracted the attention of the scientific community in the last few years. Many of the observed in-plane anisotropic properties stem from the anisotropic refractive index and elastic constants of the material but a comprehensive analysis of these fundamental properties is still lacking. Here we employ Raman and micro-reflectance measurements, using polarized light, to determine the angular dependence of the refractive index of thin MoO3 flakes and we study the directional dependence of the MoO3 Young's modulus using the buckling metrology method. We found that MoO3 displays one of the largest in-plane anisotropic mechanical properties reported for 2D materials so far.This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement n degrees 755655, ERC-StG 2017 project 2D-TOPSENSE), the European Commission, under the Graphene Flagship (Core 3, grant number 881603), the Spanish Ministry of Economy, Industry and Competitiveness through the grant MAT201787134-C2-2-R. R.F. acknowledges the support from the Spanish Ministry of Economy, Industry and Competitiveness (MINECO) through a Juan de la Cierva-formacion fellowship 2017 FJCI-2017-32919. S.P. acknowledges the fellowship PRE2018-084818. R. D'A. acknowledges financial support from the grant Grupos Consolidados UPV/EHU del Gobierno Vasco (Grant No. IT1249-19), the support of the MICINN through the grant "SelectDFT" (Grant No. FIS2016-79464-P) and travel support from the MINECO grant "TowTherm" (Grant No. MINECOG17/A01). G.S.-S. acknowledges financial support from Spanish MICIU RTI2018-099054-J-I00 and MICINN IJC2018-038164-I. Electron microscopy observations were carried out at the Centro Nacional de Microscopia Electronica, CNME-UC
Identifying phenotypes involved in susceptibility to Schistosoma mansoni infection in F1B6CBA mice
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.Schistosomiasis is a disease with a strong genetic component influenced by socioeconomic and ecological factors. Epidemiological studies have identified several genetic regions involved in the schistosomiasis susceptibility. However, it is not well known what physiological traits are predisposing to the disease. The study of experimental infections in inbred mouse strains with variable genetic susceptibility to the disease offers a good opportunity to tackle this question. F1B6CBA hybrid between the most divergent strains was infected in order to characterize the immunophenotypes that correlate with the susceptibility of schistosomiasis disease in mice. Complete blood counts and immunophenotype were determined at 0, 3, 6, and 9 weeks post infection. Nine weeks after cercariae exposure, animals were perfused and worm recovery was assessed. A large number of hepatic lesions, a reduction in the eosinophil and basophil count in the acute phase of infection and the decreased number of monocytes, neutrophils and B-lymphocytes are phenotypes associated with increased susceptibility to S. mansoni infection.The present study was supported by a grant from the Areces Foundation (2010–13) and funding of the Junta de Castilla y Leon (Orden EDU/330/2008).Peer Reviewe
Propuesta generación de energía en la población de Manaure en el departamento de la Guajira a partir de la producción eólica
El Municipio de Manaure en el departamento de la Guajira, se encuentra ubicado en la zona norte de Colombia. Este, cuenta con una problemática de abastecimiento de energía eléctrica en sus zonas rurales, por lo cual es importante realizar estudios que permitan contemplar nuevas alternativas que permitan generar electricidad aprovechando los recursos renovables en dicha zona del país.
Es allí, donde evaluando el comportamiento de los vientos generados en la región y contemplándolos como medio de generación de energía, se realiza el presente estudio viable para la producción alternativa de energía eléctrica empleando generadores eólicos que permitan abastecer mediante a esta población.1 OBJETIVOS DE LA INVESTIGACIÓN
11 OBJETIVO GENERAL
12 OBJETIVOS ESPECÍFICOS
2 PROBLEMA DE INVESTIGACIÓN
21 Contexto poblacional
22 Contexto de la propuesta:
23 Formulación del problema
3 JUSTIFICACIÓN Y DELIMITACIÓN DE LA INVESTIGACIÓN
31 JUSTIFICACIÓN
32 DELIMITACIÓN
4 MARCO TEORICO
41 Origen de los vientos
42 Funcionamiento
43 Ventajas
44 Marco Legal
45 Marco Histórico
5 DISEÑO METODOLÓGICO
6 FUENTES PARA LA OBTENCIÓN DE INFORMACIÓN
61 FUENTES PRIMARIAS
62 FUENTES SECUNDARIAS
63 RECURSOS
7 CRONOGRAMA
8 CONCLUSIONES
9 REFERENCIAS (BIBLIOGRAFÍAPregradoTecnólogo en Mecánica AutomotrizTecnología en Mecánica Automotri
La Gran Moral. MacIntyre y el carácter integrador de la filosofía perenne
En el mundo académico contemporáneo han venido tomando fuerza, desde hace varias décadas, los temas de la interdisciplinariedad y la transdisciplinariedad, como respuesta de un sector de la comunidad científica a los problemas de la especialización y a la desconexión entre las ciencias. Como todo elemento o aspecto de la realidad, este tema requiere de una debida fundamentación filosófica que se encuentra en el pensamiento clásico. En el presente artículo se intenta mostrar la relación entre la tradición de la filosofía perenne y este fundamento, atendiendo, sobre todo, a la importancia de la mirada holística del fenómeno ético y pretendiendo sustentar que el diálogo entre las ciencias sólo es posible rescatando el paradigma metafísico, legado por los griegos a la civilización occidental y defendido por MacIntyre en su libro "Ethics in the Conflicts of Modernity. An Essay on Desire, Practical Reasoning, and Narrative" (University of Cambridge, 2016)
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