165 research outputs found
Fuzzy motion adaptive algorithm and its hardware implementation for video de-interlacing
Interlacing techniques were introduced in the early analog TV transmission systems as an efficient mechanism capable of halving the video bandwidth. Currently, interlacing is also used by some modern digital TV transmission systems, however, there is a problem at the receiver side since the majority of modern display devices require a progressive scanning. De-interlacing algorithms convert an interlaced video signal into a progressive one by performing interpolation. To achieve good de-interlacing results, dynamical and local image features should be considered. The gradual adaptation of the de-interlacing technique as a function of the level of motion detected in each pixel is a powerful method that can be carried out by means of fuzzy inference. The starting point of our study is an algorithm that uses a fuzzy inference system to evaluate motion locally (FMA algorithm). Our approach is based on convolution techniques to process a fuzzy rulebase for motion-adaptive de-interlacing. Different strategies based on bi-dimensional convolution techniques are proposed. In particular, the algorithm called 'single convolution algorithm' introduces significant advantages: a more accurate measurement of the level of motion using a matrix of weights, and a unique fuzzification process after the global estimation, which reduces the computational cost. Different architectures for the hardware implementation of this algorithm are described in VHDL language. The physical realization is carried out on a RC100 Celoxica FPGA development board. © 2010 Elsevier B.V.Comunidad Europea FP7-INFSO-ICT-248858Gobierno de España TIN2005-08943-C02-01 y TEC2008-04920Junta de Andalucía P08-TIC-0367
Algoritmo adaptativo con el grado de movimiento para el desentrelazado de vídeo
En esta comunicación se presenta un algoritmo adaptativo con el movimiento para el desentrelazado de vídeo. Se basa en un sistema de inferencia difuso, que realiza una interpolación entre dos técnicas lineales en función del grado de movimiento. Se ha realizado un estudio de diferentes sistemas difusos con distinto número de funciones de pertenencia, analizándose el grado de complejidad de los mismos frente a su eficacia desentrelazando varias secuencias de vídeo.Ministerio de Educación y Ciencia TEC2005-04359/MICJunta de Andalucía TIC2006-63
Fuzzy motion adaptive algorithm for video de-interlacing
A motion adaptive algorithm for video de-interlacing is presented in this paper. It is based on a fuzzy inference system, which performs an interpolation between two linear techniques as a function of the motion level. Fuzzy systems with different number of ¿if-then¿ rules have been analyzed and compared in terms of complexity as well as efficiency in de-interlacing benchmark video sequences.Ministerio de Educación y Ciencia TEC2005-04359/MICJunta de Andalucía TIC2006-63
Diverging reproductive outcomes by maternal education during the Covid-19 pandemic across Brazilian and Colombian regions
Altres ajuts: Generalitat de Catalunya (2021 BP 00027)This work contributes to the current understanding of the heterogeneous impact of the Covid-19 pandemic on fertility. Using more than 36.4 million birth and death records for Brazil and Colombia (2015-2021), we document state-level correlations between the intensity of the pandemic, measured by the current and 9-month lagged excess mortality, and the observed number of births relative to a Covid-19-free hypothetical scenario. We disaggregate these correlations according to maternal age and years of schooling to test the hypothesis that the influence of the Covid-19 pandemic on births interacted with pre-existing forms of social inequality. Results from multivariate linear models suggest that the association between the intensity of the pandemic and the relative number of births was negative for women with at least 8 years of schooling, while it was positive or null for women with fewer years of education. This result means that in subnational areas severely hit by the Covid-19 pandemic, women with few years of schooling did not delay fertility as most women potentially did. These results suggest that disadvantaged groups in Latin America and potentially in other contexts may suffer more acutely the consequences of the Covid-19 pandemic, which has been largely neglected by studies that assume homogeneous impacts of Covid-19 on population dynamics
Dried fruit breadfruit slices by Refractive Window™ technique
Una gran cantidad de productos son secados por diversas razones, tales como la preservación, la reducción de peso y el mejoramiento de su estabilidad. Sin embargo, los métodos tradicionales de secado de alimentos sólidos no presentan productos de bajo costo y alta calidad de manera simultánea. A pesar de que existen métodos efectivos de deshidratación de los alimentos como la liofilización, que preserva el sabor, color y las vitaminas, son tecnologías de poca accesibilidad, por lo cual se hacen necesarios procesos alternativos que sean eficientes y económicos. El objetivo de esta investigación fue comparar la cinética del secado de rebanadas de fruto del árbol del pan (Artocarpus communis) mediante la técnica de Ventana Refractiva® (VR) con la de secado en bandeja. Para llegar a cabo este trabajo, se usaron rodajas de 1 y 2 mm de espesor. El secado con VR se realizó con temperatura del baño de agua a 92 °C; y el secado en bandeja a 62 °C y una velocidad del aire de 0,52 m/s. Durante el secado por la técnica de VR, el contenido de humedad llega a niveles más bajos que el secado en bandejas. De igual manera sucede con las muestras de 1 mm, las cuales, por tener menor diámetro alcanzan niveles de humedad inferior que las muestras de 2 mm. Las mayores difusividades se obtuvieron durante el secado por VR en rodajas de 1 y 2 mm con coeficientes de 6,13 y 3,90*10-9 m2/s respectivamente.A large amount of products are dried due several reasons as preservation, weight reduction and improvement of stability. However, on the market are not offered low-cost and high quality products simultaneously. Although there are effective methods of dehydrating foods such as freeze drying, which preserves the flavor, color and vitamins, they are poor accessibility technologies. Therefore, alternative processes are required to be efficient and economical. The aim of this research was compare drying kinetics of sliced of breadfruit (Artocarpus communis) using the technique of Refractive Window® (VR) with the tray drying. To carry out this study, sliced of 1 and 2 mm thick were used. Refractive window drying was performed with the water bath temperature to 92 °C; and tray drying at 62 °C and an air velocity of 0.52 m/s. During the Refractive window drying technique, the moisture content reached the lower than tray drying levels. Similarly it happened with samples of 1 mm, which, having a smaller diameter reached lower moisture levels than samples 2 mm. The higher diffusivities were obtained during drying sliced VR 1 and 2 mm with coefficients of 6.13 and 3.90*10-9 m2/s respectively
Detección y cuantificación de virus dengue 2 en lisado celular y plasma de niños por qPCR en tiempo real usando un estuche comercial y el equipo EcoTM System-Illumina
Methods for Dengue virus (DENV) diagnosis in endemic areas are greatly needed. One of them is the real-time polymerase chain reaction (qPCR) that also enables to quantitate the viral genome. Kits of qPCR for DENV are expensive and restrict their use to a small number of qPCR devices, which limits the application of the technique. Here, we evaluated the performance of a commercial kit of qPCR to DENV-2 detection on a locally available qPCR device (EcoTM System, Illumina), not cited by the kit manufacturer.VERO-76 cells lysate and plasma from children, both with confirmed ongoing DENV-2 infection, were evaluated. As specificity control, cell lysates and plasma from children infected with DENV-1, and uninfected lysate, were also included. The reactions were simultaneously evaluated in an Applied Bio systems 7300 device. The standard curve generated by EcoTM was robust (R2= 0.99) with low variability in the replicates (<10%). The reaction efficiency was high (88.8%) and signal was only obtained in lysates and plasma infected with DENV-2. There was a strong positive correlation (R2= 1.0, P= 0.0028) between the number of copies of viral RNA in the samples detected by both qPCR devices. Thus, the use of the evaluate kit for detection of DENV-2 here tested can be extended to EcoTM. With this work, technological capacity for DENV study in an endemic zone is greatly strengthened.Métodos para diagnóstico de dengue virus (DENV) en zonas endémicas son altamente necesarios. Uno de ellos es la reacción en cadena de polimerasa en tiempo real (qPCR), método que permite además la cuantificación del genoma viral. Los estuches comerciales de qPCR para DENV son costosos y restringen su uso a un número pequeño de dispositivos de qPCR, limitando la aplicación de la técnica. Aquí se evaluó el desempeño de un estuche comercial de qPCR para la detección de DENV-2 en un dispositivo de qPCR (EcoTM System, Illumina) localmente disponible, no listado por el fabricante del estuche. Lisado de células VERO-76 y plasma de niños, ambos con infección confirmada por DENV-2, fueron evaluados. Como controles de especificidad, lisado celular y plasma de niños infectados con DENV-1, además de lisado no infectado, fueron también incluidos. Las reacciones fueron además evaluadas simultáneamente en un equipo Applied Biosystem 7300, uno de los recomendados por el fabricante del estuche. La curva estándar generada por el EcoTM fue robusta (R2= 0.99), con baja variabilidad en las réplicas (<10%). La eficiencia de la reacción fue buena (88.8%) y sólo hubo amplificación en los lisados y plasma de niños infectados con DENV-2. Hubo una fuerte correlación positiva (R2= 1.0, P=0.0028) entre el número de copias de ARN viral en las muestras detectadas por los dos dispositivos de qPCR usados. Así, el uso del estuche para detección de DENV-2 aquí probado puede extenderse al EcoTM de forma segura. Este trabajo fortalece la capacidad tecnológica para el estudio de DENV en un área endémica
Point-of-care breath test for biomarkers of active pulmonary tuberculosis
Rationale: Volatile organic compounds (VOCs) in breath provide biomarkers of tuberculosis (TB) because Mycobacterium tuberculosis manufactures VOC metabolites that are detectable in the breath of infected patients. Objectives: We evaluated breath VOC biomarkers in subjects with active pulmonary TB, using an internet-linked rapid point-of-care breath test. Methods: 279 subjects were studied at four centers in three countries, Philippines, UK, and India, and data was analyzed from 251 (130 active pulmonary TB, 121 controls). A point-of-care system collected and concentrated breath and air VOCs, and analyzed them with automated thermal desorption, gas chromatography, and surface acoustic wave detection. A breath test was completed in 6 min. Chromatograms were converted to a series of Kovats Index (KI) windows, and biomarkers of active pulmonary TB were identified by Monte Carlo analysis of KI window alveolar gradients (abundance in breath minus abundance in room air). Measurements and main results: Multiple Monte Carlo simulations identified eight KI windows as biomarkers with better than random performance. Four KI windows corresponded with KI values of VOCs previously identified as biomarkers of pulmonary TB and metabolic products of M. tuberculosis, principally derivatives of naphthalene, benzene and alkanes. A multivariate predictive algorithm identified active pulmonary TB with 80% accuracy (area under curve of receiver operating characteristic curve), sensitivity = 71.2%, and specificity = 72%. Accuracy increased to 84% in age-matched subgroups. In a population with 5% prevalence, the breath test would identify active pulmonary TB with 98% negative predictive value and 13% positive predictive value. Conclusions: A six-minute point-of-care breath test for volatile biomarkers accurately identified subjects with active pulmonary TB. © 2011 Elsevier Ltd. All rights reserved
Isolation of human bone marrow mesenchymal stem cells and evaluation of their osteogenic potential
Las células madre mesenquimatosas de médula ósea humana (abreviadas hBMSCs) constituyen una fuente de células auto-renovables con alto potencial de diferenciación, comúnmente aisladas a partir de los aspirados medulares en huesos largos. Su diferenciación hacia el linaje osteogénico, por ejemplo, ha sido ampliamente utilizada para la evaluación biológica de biomateriales o matrices con aplicaciones en la ingeniería de tejidos óseos. El objetivo de este trabajo consistió en aislar hBMSCs a partir de la cabeza femoral de pacientes sometidos a artroplastia total de cadera, así como evaluar su potencial osteogénico. Brevemente, se extrajo el hueso esponjoso y se disgregó mecánicamente; las células desprendidas se cultivaron y las células no adherentes se eliminaron luego de 4 días. El potencial osteogénico se evaluó en la quinta generación de cultivo, mediante ensayos de diferenciación a 14 y 20 días donde se compararon cultivos con y sin suplementos osteogénicos. La evaluación se realizó mediante tinción con Alizarina Roja y la cuantificación de los niveles de expresión génica de los marcadores osteogénicos colágeno tipo I, osteonectinca y sialoprotiena ósea mediante RT-PCR en tiempo real. Las hBMSCs obtenidas presentaron un fenotipo no-diferenciado estable, así como la capacidad de mineralizar la matriz extracelular y expresar un fenotipo similar al osteoblasto durante la inducción osteogénica. Los tres marcadores evaluados se sobre-expresaron en los cultivos en condiciones osteogénicas, y se encontró que cambios hasta de 2X en sus niveles de expresión son relevantes para el desarrollo del proceso de diferenciación. El modelo de hBMSCS presentado podría ser utilizado para la evaluación in vitro de la osteoinductividad de diferentes biomateriales, moléculas bioactivas o matrices para ingeniería de tejidos.Human bone marrow mesenchymal stem cells (hBMSCs) comprise a cell population capable of self-renewal and multilineage differentiation commonly isolated from bone marrow aspirates of large bones. Their osteogenic potential has been extensively exploited for the biological evaluation of scaffolds or biomaterials with applications in bone tissue engineering. This work aimed to isolate hBMSCs from femoral heads of patients undergoing total hip arthroplasty and to evaluate their osteogenic potential. Briefly, the trabecular bone was extracted and mechanically disaggregated; the released cells were cultured and non-adherent cells were removed after 4 days. The osteogenic potential was evaluated at the fifth passage after 14 and 20 days of induction, comparing cultures with and without osteogenic supplements, via Alizarin red staining and the quantification of the gene expression levels of the osteogenic markers collagen type I, osteonectin and bone sialoprotein through real-time RT-PCR. The obtained hBMSCs presented a stable undifferentiated phenotype after prolonged cell culture, matrix mineralization capabilities and expression of osteoblast phenotype upon osteogenic induction. The three markers were up-regulated in cultures under osteogenic conditions and 2 fold differences in their expression levels were found to be significant for the onset of the differentiation process. The obtained hBMSCs may have applications on the in vitro evaluation of the osteoinductivity of different biomaterials, bioactive molecules or tissue engineering scaffolds
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