80 research outputs found
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Cloud tomography applied to sky images: a virtual testbed
Two tomographic techniques are applied to two simulated sets of sky images with different cloud fraction. The Algebraic Reconstruction Technique (ART) is applied to optical depth maps from sky images to reconstruct 3-D cloud extinction coefficients without considering multiple scattering effects. Reconstruction accuracy is explored for different products, including surface irradiance and extinction coefficients, and as a function of the number of available sky imagers and setup distance. Increasing the number of imagers improves the accuracy of the 3-D reconstruction: for surface irradiance, the error decreases significantly up to four imagers at which point the improvements become marginal. But using nine imagers gives more robust results in practical situations in which the circumsolar region of images has to be excluded due to poor cloud detection. The ideal distance between imagers was also explored: for a cloud height of 1 km, increasing distance up to 3 km (the domain length) improved the 3-D reconstruction. An iterative reconstruction technique that iteratively updated the source function improved the results of the ART by minimizing the error between input red radiance images and reconstructed red radiance simulations. For the best case of a nine-imager deployment, the ART and iterative method resulted in 53.4% and 33.6% relative mean absolute error for the extinction coefficients, respectively.The authors acknowledge funding from the California Energy Commission EPIC program. Felipe Mejia was supported by the National Science Foundation Graduate Research Fellowship under Grant No. (DGE-1144086). In addition, Íñigo de la Parra has been partially supported by the Spanish State Research Agency (AEI) and FEDER-UE under grants DPI2016-80641-R and DPI2016-80642-R
Three-dimensional quasi-conformal transformation optics through numerical optimization
In this paper we demonstrate the possibility to achieve 3-dimensional quasi-conformal transformation optics through parametrization and numerical optimization without using sliding boundary conditions. The proposed technique, which uses a quasi-Newton method, is validated in two cylindrical waveguide bends as design examples. Our results indicate an arbitrarily small average anisotropy can be achieved in 3D transformation optics as the number of degrees of freedom provided by the parametrization was increased. The waveguide simulations confirm modal preservation when the residual anisotropy is neglected24151646516470CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFINANCIADORA DE ESTUDOS E PROJETOS - FINEPFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAIS - FAPEMIGFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão temnão temnão temnão temnão te
Quid: observatorio de medios
El informe está dividido en cuatro apartados:
“Derecho a la información y transparencia”, “La televisión
mexicana”, “Empresas y prácticas periodísticas” y “Los
que se fueron”. En el primero de ellos se presenta
un texto que ayuda a entender cuál
es el momento en el que se encuentran las propuestas legislativas
para regular a los medios y las telecomunicaciones
en México, y una evaluación de los primeros
cinco años del Instituto de Transparencia e Información
Pública de Jalisco. El segundo apartado del informe es ecléctico, pues se compone de artículos que trabajan distintas temáticas
de la televisión:la estructura y oferta de la televisión en nuestro
país (en particular en la ciudad de Guadalajara), la televisión por cable (enfatizando el caso de Megacable), un recuento de
cómo se gestó el Canal 44 y de sus prospectivas en 2011, y
los mundiales de futbol. La tercera parte del informe documenta algunas de las
situaciones más importantes que se viven en el periodismo
local: estos trabajos presentan sistemas en crisis (alta vulnerabilidad de los periodistas mexicanos ante un clima de violencia que lejos de
disminuir va en aumento, y la participación,
por acción u omisión, del Estado mexicano en la sistemática
violación de los derechos de quienes dedican su
vida al trabajo periodístico.
Los siguientes artículos tratan sobre las transformaciones de las empresas periodísticas,
particularmente las del sector de la prensa
escrita: la rápida e inexorable desaparición de los suplementos
culturales, y una radiografía sobre las formas de producción de algunas
secciones internacionales de los periódicos tapatíos.
Al final se presentan las semblanzas de José Galindo, Raúl Mora Lomelí, S.J., Tomás Eloy Martínez y Juan Pablo Rosell.ITESO, A.C
IFNγ Response to Mycobacterium tuberculosis, Risk of Infection and Disease in Household Contacts of Tuberculosis Patients in Colombia
OBJECTIVES: Household contacts (HHCs) of pulmonary tuberculosis patients are at high risk of Mycobacterium tuberculosis infection and early disease development. Identification of individuals at risk of tuberculosis disease is a desirable goal for tuberculosis control. Interferon-gamma release assays (IGRAs) using specific M. tuberculosis antigens provide an alternative to tuberculin skin testing (TST) for infection detection. Additionally, the levels of IFNgamma produced in response to these antigens may have prognostic value. We estimated the prevalence of M. tuberculosis infection by IGRA and TST in HHCs and their source population (SP), and assessed whether IFNgamma levels in HHCs correlate with tuberculosis development. METHODS: A cohort of 2060 HHCs was followed for 2-3 years after exposure to a tuberculosis case. Besides TST, IFNgamma responses to mycobacterial antigens: CFP, CFP-10, HspX and Ag85A were assessed in 7-days whole blood cultures and compared to 766 individuals from the SP in Medellín, Colombia. Isoniazid prophylaxis was not offered to child contacts because Colombian tuberculosis regulations consider it only in children under 5 years, TST positive without BCG vaccination. RESULTS: Using TST 65.9% of HHCs and 42.7% subjects from the SP were positive (OR 2.60, p<0.0001). IFNgamma response to CFP-10, a biomarker of M. tuberculosis infection, tested positive in 66.3% HHCs and 24.3% from the SP (OR = 6.07, p<0.0001). Tuberculosis incidence rate was 7.0/1000 person years. Children <5 years accounted for 21.6% of incident cases. No significant difference was found between positive and negative IFNgamma responders to CFP-10 (HR 1.82 95% CI 0.79-4.20 p = 0.16). However, a significant trend for tuberculosis development amongst high HHC IFNgamma producers was observed (trend Log rank p = 0.007). DISCUSSION: CFP-10-induced IFNgamma production is useful to establish tuberculosis infection prevalence amongst HHC and identify those at highest risk of disease. The high tuberculosis incidence amongst children supports administration of chemoprophylaxis to child contacts regardless of BCG vaccination
Chagas Cardiomyopathy Manifestations and Trypanosoma cruzi Genotypes Circulating in Chronic Chagasic Patients
Chagas disease caused by Trypanosoma cruzi is a complex disease that is endemic and an important problem in public health in Latin America. The T. cruzi parasite is classified into six discrete taxonomic units (DTUs) based on the recently proposed nomenclature (TcI, TcII, TcIII, TcIV, TcV and TcVI). The discovery of genetic variability within TcI showed the presence of five genotypes (Ia, Ib, Ic, Id and Ie) related to the transmission cycle of Chagas disease. In Colombia, TcI is more prevalent but TcII has also been reported, as has mixed infection by both TcI and TcII in the same Chagasic patient. The objectives of this study were to determine the T. cruzi DTUs that are circulating in Colombian chronic Chagasic patients and to obtain more information about the molecular epidemiology of Chagas disease in Colombia. We also assessed the presence of electrocardiographic, radiologic and echocardiographic abnormalities with the purpose of correlating T. cruzi genetic variability and cardiac disease. Molecular characterization was performed in Colombian adult chronic Chagasic patients based on the intergenic region of the mini-exon gene, the 24Sα and 18S regions of rDNA and the variable region of satellite DNA, whereby the presence of T.cruzi I, II, III and IV was detected. In our population, mixed infections also occurred, with TcI-TcII, TcI-TcIII and TcI-TcIV, as well as the existence of the TcI genotypes showing the presence of genotypes Ia and Id. Patients infected with TcI demonstrated a higher prevalence of cardiac alterations than those infected with TcII. These results corroborate the predominance of TcI in Colombia and show the first report of TcIII and TcIV in Colombian Chagasic patients. Findings also indicate that Chagas cardiomyopathy manifestations are more correlated with TcI than with TcII in Colombia
II Simposio Internacional Cátedra Minuto de Dios. Experiencias e impacto de los cursos misionales en la educación superior.
El impacto de la formación integral y la misionalidad desde la Educación Superior, son
asuntos que requieren análisis y reflexión desde su intencionalidad de formación, proceso
enseñanza-aprendizaje, sistema de evaluación y los logros que generan y que, a
futuro, podrán permitir mejoras en las condiciones de entornos cercanos como efecto
clave de la formación.
En este sentido, el II Simposio Internacional de Cátedra Minuto de Dios: Experiencias e
impacto de los Cursos Misionales en la Educación Superior. Caso de estudio: “Cátedra
Minuto de Dios”, permitió a los participantes acercarse y reconocer experiencias
significativas a través de los conocimientos y saberes visibilizados y socializados por
directivas educativas, docentes y estudiantes que desde perspectivas nacionales e
internacionales dieron a conocer la evolución de dichos espacios académicos considerados
como cursos misionales, en las Instituciones de Educación Superior, desde el
reflejo de la fundamentación y la filosofía Institucional.
De esta manera, UNIMINUTO considera que el contraste académico con otras universidades,
en el contexto de su filosofía particular, solidifica el camino de un servicio
educativo de calidad, pertinente e inclusivo y, además, inspira a quienes quieran
profundizar y proponer nuevos desarrollos en esta temática
Desafíos actuales de la educación superior
El presente libro corresponde al trabajo investigativo realizado por sus autores frente a los desafíos que enfrenta y enfrentará la educación en tiempos actuales (provisional)
XVI International Congress of Control Electronics and Telecommunications: "Techno-scientific considerations for a post-pandemic world intensive in knowledge, innovation and sustainable local development"
Este título, sugestivo por los impactos durante la situación de la Covid 19 en el mundo, y que en Colombia lastimosamente han sido muy críticos, permiten asumir la obligada superación de tensiones sociales, políticas, y económicas; pero sobre todo científicas y tecnológicas.
Inicialmente, esto supone la existencia de una capacidad de la sociedad colombiana por recuperar su estado inicial después de que haya cesado la perturbación a la que fue sometida por la catastrófica pandemia, y superar ese anterior estado de cosas ya que se encontraban -y aún se encuentran- muchos problemas locales mal resueltos, medianamente resueltos, y muchos sin resolver: es decir, habrá que rediseñar y fortalecer una probada resiliencia social existente - producto del prolongado conflicto social colombiano superado parcialmente por un proceso de paz exitoso - desde la tecnociencia local; como lo indicaba Markus Brunnermeier - economista alemán y catedrático de economía de la Universidad de Princeton- en su libro The Resilient Society…La cuestión no es preveerlo todo sino poder reaccionar…aprender a recuperarse rápido.This title, suggestive of the impacts during the Covid 19 situation in the world, and which have unfortunately been very critical in Colombia, allows us to assume the obligatory overcoming of social, political, and economic tensions; but above all scientific and technological.
Initially, this supposes the existence of a capacity of Colombian society to recover its initial state after the disturbance to which it was subjected by the catastrophic pandemic has ceased, and to overcome that previous state of affairs since it was found -and still is find - many local problems poorly resolved, moderately resolved, and many unresolved: that is, an existing social resilience test will have to be redesigned and strengthened - product of the prolonged Colombian social conflict partially overcome by a successful peace process - from local technoscience; As Markus Brunnermeier - German economist and professor of economics at Princeton University - indicates in his book The Resilient Society...The question is not to foresee everything but to be able to react...learn to recover quickly.Bogot
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
EVALUACIÓN DE RIESGOS FINANCIEROS EN EL MERCADO ELÉCTRICO COLOMBIANO.
Este artículo presenta los resultados de adaptar técnicas financieras al cálculo de
un portafolio de inversiones en el mercado eléctrico. Al definir políticas de
inversión a largo plazo se propone usar los caudales medios de los ríos en el país
para pronosticar el precio de la energía eléctrica. Luego un modelo de
programación cuadrática con restricciones lineales es aplicado para determinar
la estructura óptima del portafolio de inversiones y calculado el denominado
�Value at Risk (VaR)�, o valoración del riesgo del mismo. Finalmente se
presentan algunas recomendaciones acerca de otras metodologías a analizar en
posteriores estudios, para resolver este mismo problema
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