305 research outputs found

    Reducción de dimensiones para clasificación de datos multidimensionales usando medidas de información

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    El enorme desarrollo tecnológico ha creado un concepto de información con áreas extensas de aplicación para tareas referentes al entrenamiento de sistemas automáticos. Este trabajo propone una metodología basada en el análisis de componentes independientes (ICA), que incluye el uso de medidas de información, para realizar reducción de dimensiones en conjuntos de datos multidimensionales. La metodología usa un principio de relevancia, con el fin de hallar la representación reducida mientras se conserva la estructura relacionada a la información inicial. La metodología se compara y se conjuga con un sistema básico de selección de características cuya función de evaluación usa la medida de entropía logrando mejores resultados en la clasificación

    Effect of dilute sulfuric acid pretreatment on the physicochemical properties and enzymatic hydrolysis of coffee cut-stems

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    Coffee-cut stems are a potential fermentable sugars source, which can be upgraded in different value-added products and energy vectors. Nevertheless, there are few reports focused on the acid pretreatment and saccharification processes. Thus, this paper evaluates the effect of the acid pretreatment and saccharification conditions of coffee cut-stems to find the highest sugar yield. Thereafter, the influence of the residence time in the acid pretreatment and the -glucosidase supplementation in the saccharification process were analyzed. The combined severity factor and crystallinity index were used as metrics to evaluate both processes. In all assays, an increase in the crystallinity index was observed. Furthermore, a nonlinear trend of the combined severity factor respect to the residence time in the acid pretreatment was evidenced. The highest sugar yield was 66.75% with a combined severity factor of 1.84. The better saccharification process was achieved at combined severity factor of 2.01 with a digestibility of 43%. The addition of -glucosidase in the enzymatic hydrolysis allows increasing the value to 69.07%. Hence, low temperatures, acid concentrations, and the -glucosidase supplementation allows obtaining a high sugar yield from coffee cut stems.The authors express their gratitude for the financial support to the Programme of ERASMUS + - International Credit Mobility celebrated between the Universidad Nacional de Colombia at Manizales and the University of Minho. The COLCIENCIAS program “Jóvenes Investigadores e Innovadores, Convocatoria 761 de 2016”, the international collaboration project COLCIENCIAS – CONICYT with code PCCI140052, HERMES code 23567 (23876) entitled “Análisis Tecno-económico y Ambiental de Biorefinerías a partir de Residuos Lignocelulósicos con Esquemas de Recirculación de Microorganismos”, the research program entitled “Reconstrucción del tejido social en zonas posconflicto en Colombia” SIGP code: 57579 with the project entitled “Competencias empresariales y de innovación para el desarrollo económico y la inclusión productiva de las regiones afectadas por el conflicto colombiano” SIGP code 58907. Contract number: FP44842-213-2018.info:eu-repo/semantics/publishedVersio

    Reducción de dimensiones para clasificación de datos multidimensionales usando medidas de información

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    El enorme desarrollo tecnológico ha creado un concepto de información con áreas extensas de aplicación para tareas referentes al entrenamiento de sistemas automáticos. Este trabajo propone una metodología basada en el análisis de componentes independientes (ICA), que incluye el uso de medidas de información, para realizar reducción de dimensiones en conjuntos de datos multidimensionales. La metodología usa un principio de relevancia, con el fin de hallar la representación reducida mientras se conserva la estructura relacionada a la información inicial. La metodología se compara y se conjuga con un sistema básico de selección de características cuya función de evaluación usa la medida de entropía logrando mejores resultados en la clasificación

    Reducción de dimensiones para clasificación de datos multidimensionales usando medidas de información

    Get PDF
    El enorme desarrollo tecnológico ha creado un concepto de información con áreas extensas de aplicación para tareas referentes al entrenamiento de sistemas automáticos. Este trabajo propone una metodología basada en el análisis de componentes independientes (ICA), que incluye el uso de medidas de información, para realizar reducción de dimensiones en conjuntos de datos multidimensionales. La metodología usa un principio de relevancia, con el fin de hallar la representación reducida mientras se conserva la estructura relacionada a la información inicial. La metodología se compara y se conjuga con un sistema básico de selección de características cuya función de evaluación usa la medida de entropía logrando mejores resultados en la clasificación

    Drainage And Sedimentary Response Of The Northern Andes And The Pebas System To Miocene Strike-slip Tectonics: A Source To Sink Study Of The Magdalena Basin

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    Miocene strike-slip tectonics was responsible for creating and closing short-lived (ca. 6 Ma) passages and the emergence of isolated topography in the Northern Andes. These geological events likely influenced the migration and/or isolation of biological populations. To better understand the paleogeography of the Miocene hinterland and foreland regions in the Northern Andes, we conducted a source-to-sink approach in the Magdalena Basin. This basin is located between the Central and Eastern Cordilleras of Colombia and contains an ample Miocene record, which includes Lower Miocene fine-grained strata and Middle Miocene to Pliocene coarsening-up strata. Our study presents a new data set that includes detrital U–Pb zircon ages (15 samples), sandstone petrography (45 samples) and low-temperature thermochronology from the Southern Central Cordillera (19 dates); which together with previously published data were used to construct a paleogeographical model of the Miocene hinterland and foreland regions in the Northern Andes. The evolution of the Magdalena Basin during the Miocene was characterized by playa and permanent lake systems at ca. 17.5 Ma, which may be related to a marine incursion into NW South America and western Amazonia. The appearance of Eocene to Miocene volcanic sources in the Honda Group after ca. 16 Ma suggests the development of fluvial passages, which connected the Pacific with the western Amazonia and Caribbean regions. These passages were synchronous with a time of Miocene exhumation and topographic growth (ca. 16 to 10 Ma) in the Central Cordillera and the transition from lacustrine to fluvial deposition in the Magdalena Basin. Middle to Late Miocene strike-slip deformation promoted by oblique plate convergence and the oblique collision of the Panamá-Chocó Block likely explains the synchronous along-strike fragmentation and exhumation in the Central Cordillera

    Detection of transcriptional difference of porcine imprinted genes using different microarray platforms

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    BACKGROUND: Presently, multiple options exist for conducting gene expression profiling studies in swine. In order to determine the performance of some of the existing microarrays, Affymetrix Porcine, Affymetrix Human U133+2.0, and the U.S. Pig Genome Coordination Program spotted glass oligonucleotide microarrays were compared for their reproducibility, coverage, platform independent and dependent sensitivity using fibroblast cell lines derived from control and parthenogenic porcine embryos. RESULTS: Array group correlations between technical replicates demonstrated comparable reproducibility in both Affymetrix arrays. Glass oligonucleotide arrays showed greater variability and, in addition, approximately 10% of probes had to be discarded due to slide printing defects. Probe level analysis of Affymetrix Human arrays revealed significant variability within probe sets due to the effects of cross-species hybridization. Affymetrix Porcine arrays identified the greatest number of differentially expressed genes amongst probes common to all arrays, a measure of platform sensitivity. Affymetrix Porcine arrays also identified the greatest number of differentially expressed known imprinted genes using all probes on each array, an ad hoc measure of realistic performance for this particular experiment. CONCLUSION: We conclude that of the platforms currently available and tested, the Affymetrix Porcine array is the most sensitive and reproducible microarray for swine genomic studies
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