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Trucos y secretos de la praxis cuantitativa
No full textCentra los temas de interés en la praxis cuantitativa de la investigación, abordando ocho apartados o unidades. La primera y segunda unidad corresponden al abordaje epistemológico, la tercera unidad se presentan aspectos prácticos y útiles para comprender cómo se alcanza el sentido del entendimiento. La cuarta unidad explica a detalle el significado de la variable de interés según el alcance del estudio cuantitativo. En las unidades cinco y seis se develan secretados vinculados a las rutas, procedimientos y cuestionamientos para iniciar y desarrollar la construcción del problema en los estudios cuantitativos, además, se replantean interrogantes sobre el arte de operacionalizar las variables. La unidad siete describe los diseños cuantitativos respondiendo a algunas interrogantes relacionadas a la elección de los diseños en función a los alcances de investigación, cómo determinar la población y la muestra, diferencias entre técnica e instrumentos, y cuáles son los requerimientos mínimos de un instrumento cuantitativo. Finalmente, la última unidad que corresponde a la prueba de hipótesis y los procedimientos a seguir en la investigación, en la que se establece como norma aprender a entender las funciones de los estadísticos
Bandgap engineering of hydrogenated a-SiC:H thin films for photoelectrochemical water splitting applications
No full textBandgap engineering of a-SiC:H thin films was carried out to assess the material light absorption without compromising its photoelectrochemical water splitting capabilities. The tailoring was performed by varying the hydrogen concentration in the semiconductor and by post-deposition isochronical annealing treatments from 100 ?C to 700 ?C. Bandgap values were obtained by fitting the fundamental absorption region of the absorption coefficient using three different models. Differences among bandgap values extracted by these methods and its correlation with the a-SiC:H structure, demonstrate that structural features, rather than a hydrogen rearrangement or depletion, would be responsible for annealing induced optical bandgap increment. These features are taking in advantage for the bandgap engineering of a-SiC:H without changing Si-C stoichiometry. Optical bandgap values for p-doped a-SiC:H samples gradually increased from 2.59 to 2.76 eV upon performing each annealing step until 600 ?C. Temperature at which an enhancement in the electric performance is observed. We believe, these results will help on the design of monolithic tandem solar cells for water splitting applications. © 2020 IOP Publishing Ltd Printed in the UKConsejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Molecular surveillance of the Plasmodium vivax multidrug resistance 1 gene in Peru between 2006 and 2015
No full textBackground: The high incidence of Plasmodium vivax infections associated with clinical severity and the emergence of chloroquine (CQ) resistance has posed a challenge to control efforts aimed at eliminating this disease. Despite conflicting evidence regarding the role of mutations of P. vivax multidrug resistance 1 gene (pvmdr1) in drug resistance, this gene can be a tool for molecular surveillance due to its variability and spatial patterns. Methods: Blood samples were collected from studies conducted between 2006 and 2015 in the Northern and Southern Amazon Basin and the North Coast of Peru. Thick and thin blood smears were prepared for malaria diagnosis by microscopy and PCR was performed for detection of P. vivax monoinfections. The pvmdr1 gene was subsequently sequenced and the genetic data was used for haplotype and diversity analysis. Results: A total of 550 positive P. vivax samples were sequenced; 445 from the Northern Amazon Basin, 48 from the Southern Amazon Basin and 57 from the North Coast. Eight non-synonymous mutations and three synonymous mutations were analysed in 4,395 bp of pvmdr1. Amino acid changes at positions 976F and 1076L were detected in the Northern Amazon Basin (12.8%) and the Southern Amazon Basin (4.2%) with fluctuations in the prevalence of both mutations in the Northern Amazon Basin during the course of the study that seemed to correspond with a malaria control programme implemented in the region. A total of 13 pvmdr1 haplotypes with non-synonymous mutations were estimated in Peru and an overall nucleotide diversity of π = 0.00054. The Northern Amazon Basin was the most diverse region (π = 0.00055) followed by the Southern Amazon and the North Coast (π = 0.00035 and π = 0.00014, respectively). Conclusion: This study showed a high variability in the frequencies of the 976F and 1076L polymorphisms in the Northern Amazon Basin between 2006 and 2015. The low and heterogeneous diversity of pvmdr1 found in this study underscores the need for additional research that can elucidate the role of this gene on P. vivax drug resistance as well as in vitro and clinical data that can clarify the extend of CQ resistance in Peru. © 2020, The Author(s).Fondo Nacional de Desarrollo Científico y Tecnológico - Fondecy
Revealing the air pollution burden associated with internal Migration in Peru
No full textThis study aims to quantify changes in outdoor (ambient) air pollution exposure from different migration patterns within Peru and quantify its effect on premature mortality. Data on ambient fine particulate matter (PM2.5) was obtained from the National Aeronautics and Space Administration (NASA). Census data was used to calculate rates of within-country migration at the district level. We calculated differences in PM2.5 exposure between “current” (2016–2017) and “origin” (2012) districts for each migration patterns. Using an exposure-response relationship for PM2.5 extracted from a meta-analysis, and mortality rates from the Peruvian Ministry of Health, we quantified premature mortality attributable to each migration pattern. Changes in outdoor PM2.5 exposure were observed between 2012 and 2016 with highest levels of PM2.5 in the Department of Lima. A strong spatial autocorrelation of outdoor PM2.5 values (Moran’s I = 0.847, p-value=0.001) was observed. In Greater Lima, rural-to-urban and urban-to-urban migrants experienced 10-fold increases in outdoor PM2.5 exposure in comparison with non-migrants. Changes in outdoor PM2.5 exposure due to migration drove 137.1 (95%CI: 93.2, 179.4) premature deaths related to air pollution, with rural-urban producing the highest risk of mortality from exposure to higher levels of ambient air pollution. Our results demonstrate that the rural-urban and urban-urban migrant groups have higher rates of air pollution-related deaths. © 2020, The Author(s).Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Morphological and metabolic profiling of a tropical-adapted potato association panel subjected to water recovery treatment reveals new insights into plant vigor
No full textPotato (Solanum tuberosum L.) is one of the world's most important crops, but it is facing major challenges due to climatic changes. To investigate the effects of intermittent drought on the natural variability of plant morphology and tuber metabolism in a novel potato association panel comprising 258 varieties we performed an augmented block design field study under normal irrigation and under water-deficit and recovery conditions in Ica, Peru. All potato genotypes were profiled for 45 morphological traits and 42 central metabolites via nuclear magnetic resonance. Statistical tests and norm of reaction analysis revealed that the observed variations were trait specific, that is, genotypic versus environmental. Principal component analysis showed a separation of samples as a result of conditional changes. To explore the relational ties between morphological traits and metabolites, correlation-based network analysis was employed, constructing one network for normal irrigation and one network for water-recovery samples. Community detection and difference network analysis highlighted the differences between the two networks, revealing a significant correlational link between fumarate and plant vigor. A genome-wide association study was performed for each metabolic trait. Eleven single nucleotide polymorphism (SNP) markers were associated with fumarate. Gene Ontology analysis of quantitative trait loci regions associated with fumarate revealed an enrichment of genes regulating metabolic processes. Three of the 11 SNPs were located within genes, coding for a protein of unknown function, a RING domain protein and a zinc finger protein ZAT2. Our findings have important implications for future potato breeding regimes, especially in countries suffering from climate change. © 2020 The Authors. The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Learning from the 2018 Western Japan heavy rains to detect floods during the 2019 Hagibis Typhoon
No full textApplications of machine learning on remote sensing data appear to be endless. Its use in damage identification for early response in the aftermath of a large-scale disaster has a specific issue. The collection of training data right after a disaster is costly, time-consuming, and many times impossible. This study analyzes a possible solution to the referred issue: the collection of training data from past disaster events to calibrate a discriminant function. Then the identification of affected areas in a current disaster can be performed in near real-time. The performance of a supervised machine learning classifier to learn from training data collected from the 2018 heavy rainfall at Okayama Prefecture, Japan, and to identify floods due to the typhoon Hagibis on 12 October 2019 at eastern Japan is reported in this paper. The results show a moderate agreement with flood maps provided by local governments and public institutions, and support the assumption that previous disaster information can be used to identify a current disaster in near-real time. © 2020 by the authors.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Antimicrobial sensitivity of pathogenic Yersinia ruckeri from central and southern highlands of Peru
No full textThe objectives of this study were to establish the phenotypic antimicrobial sensitivity of the isolates from Peruvian rainbow trout using the procedures recommended by OIEConsejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Stratigraphic architecture, paleogeography and provenance of the cenozoic sedimentary rocks in southern perú (Tacna, 18° s) . [Arquitectura estratigráfica, paleogeografía y proveniencia sedimentaria de las rocas cenozoicas del sur de perú (Tacna, 18° s)]
No full textThe Cenozoic rocks lying in the Province of Tacna (18° S), southern Perú, represent approximately 600 m of stratigraphic thickness. This stacking groups the Sotillo (Paleocene), Moquegua Inferior (Eocene), Moquegua Superior (Oligocene), Huaylillas (Miocene) and Millo formations (Pliocene), and these are the sedimentary fill of the Moquegua Basin. The sediments of the three latter formations are organized into nine sedimentary facies and five architectural elements. Their facies associations suggest the existence of an ancient highly channelized multi-lateral fluvial braided system, with upward increase of pyroclastic and conglomeratic depositions. The heavy mineral spectra make each lithostratigraphic unit unique and distinguishable, being the sediments of the Moquegua Superior Formation rich in garnets, titanites and zircons; while the sediments of the Huaylillas and Millo formations in clinopyroxenes. This mineral arrangement becomes an excellent tool for stratigraphic correlations between outcrops and subsurface stratigraphy (by means of well cores studies) and allow to sketch out a new stratigraphic framework and a complex of rocky blocks bounded by normal faults, often tilted. The sediment mineralogy also suggests that the rocks conforming the Western Cordillera were the main source of sediments for the Moquegua Basin in Tacna. In this context, the detritus of the Moquegua Superior Formation derives mainly from the erosion of the rocks forming the Coastal Basal Complex (Proterozoic), the Ambo Group (Carboniferous) and the Junerata/Chocolate Formation (Early Jurassic). The Huaylillas Formation is a pyroclastic and sedimentary unit which components derived mainly from the Huaylillas volcanism (Miocene) and partly from the denudation of the Toquepala Group (Late Cretaceous). The Huaylillas Formation widely contrasts to the underlying Moquegua Superior Formation due its mineralogy and facies. Finally, the detritus of the Millo Formation derived mostly from the rocks forming the Barroso Formation (Pliocene), and their facies represent a higher contrast in relation to the underlying units due its notorious conglomerate facies. © INRA and Springer-Verlag France 2015.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Magnetic bio-nanocomposite catalysts of CoFe2O4/hydroxyapatite-lipase for enantioselective synthesis provide a framework for enzyme recovery and reuse
No full textEnzymatic catalysis is a sustainable alternative for cost-prohibitive catalysts based on noble metals and rare earths. Enzymes can catalyze selective reactions under mild conditions. Enzyme recovery after a reaction for its reuse is still a challenge for industrial application. Herein, a biocompatible magnetic nanocomposite is presented as alternative for enzyme stabilization and easy recovery. The magnetic core of CoFe2O4 provides capabilities for magnetic recovery. Two different functionalization methods based on adsorption of enzyme onto biocompatible hydroxyapatite (HAP) and through covalent bonding using a molecular spacer based on 3-Aminopropyl)triethoxysilane (APTES) have been evaluated. Both enzymatic bio-nanocomposites presented high selectivity for the transesterification reaction of racemic mixtures of (R,S)-1-phenylethanol, with complete conversion of (R)-1-phenylethanol enantiomer. Studies with different solvent and temperature had demonstrated high range of operation conditions due to enzyme stabilization provided by surface attachment. Meanwhile, magnetic properties allowed easy recovery through application of an external magnetic field for enzyme reuse. Results showed high stability of lipase covalently bond to CoFe2O4/HAP over several reaction cycles.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
A categorization of simultaneous localization and mapping knowledge for mobile robots
No full textLos robots autónomos están desempeñando un papel importante en las actividades académicas, tecnológicas y científicas. Por lo tanto, su comportamiento es cada vez más complejo. Las principales tareas de los robots autónomos incluyen mapear un entorno y localizarse a sí mismos. Estas tareas comprenden el problema de localización y mapeo simultáneos (SLAM). La representación del conocimiento de SLAM (p. ej., características del robot, información del entorno, información de mapeo y ubicación), con un modelo estándar y bien definido, proporciona la base para desarrollar soluciones eficientes e interoperables. Sin embargo, hasta donde sabemos, no existe una clasificación común de tales conocimientos. Muchos trabajos existentes basados en la Web Semántica han formulado ontologías para modelar información relacionada solo con algunos aspectos de SLAM, sin un arreglo estándar. En este artículo proponemos una categorización del conocimiento gestionado en SLAM, basada en ontologías existentes y principios de SLAM. También clasificamos ontologías recientes y populares según nuestras categorías propuestas y destacamos las lecciones a aprender de las soluciones existentes. © 2020 ACM.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte