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PatagoniaMet: A multi-source hydrometeorological dataset for Western Patagonia
Get PDFWestern Patagonia (40–56°S) is a clear example of how the systematic lack of publicly available data and poor quality control protocols have hindered further hydrometeorological studies. To address these limitations, we present PatagoniaMet (PMET), a compilation of ground-based hydrometeorological data (PMET-obs; 1950–2020), and a daily gridded product of precipitation and temperature (PMET-sim; 1980–2020). PMET-obs was developed considering a 4-step quality control process applied to 523 hydrometeorological time series obtained from eight institutions in Chile and Argentina. Following current guidelines for hydrological datasets, several climatic and geographic attributes were derived for each catchment. PMET-sim was developed using statistical bias correction procedures, spatial regression models and hydrological methods, and was compared against other bias-corrected alternatives using hydrological modelling. PMET-sim was able to achieve Kling-Gupta efficiencies greater than 0.7 in 72% of the catchments, while other alternatives exceeded this threshold in only 50% of the catchments. PatagoniaMet represents an important milestone in the availability of hydro-meteorological data that will facilitate new studies in one of the largest freshwater ecosystems in the world
Tax revenue measurement using OWA operators
No full textThe aim of this paper is to present the application of the OWA operator and some of its extensions in the calculation of continent and global tax revenues. The idea is to present how the analysis of an important economic indicator can vary depending on how the information is aggregated. An example was employed based on the Organization for Economic Co-operation and Development (OECD) database using 111 countries that were divided by continent, and then the global tax revenue was calculated using different aggregation operators. Different analyses can be carried out by governments and enterprises to improve decision making and fiscal politics
The lifestyle of the Pedagogy in Physical Education students at a university in south-central Chile
Get PDFLos estilos de vida de los universitarios chilenos suelen ser poco saludables, con respecto a la práctica de actividad física, alimentación, consumo de tabaco, alcohol, drogas y sueño nocturno. Los objetivos del estudio fueron describir los estilos de vida del estudiantado de Pedagogía en Educación Física de una Universidad del centro sur de Chile, junto con establecer relaciones entre las variables de los comportamientos del mismo grupo de estudiantes. Se realizó un estudio cuantitativo, de diseño transversal, de alcance descriptivo y correlacional. El instrumento aplicado fue el cuestionario de preguntas cerradas ESTIPENDO, respondido por 108 estudiantes de la mencionada carrera. El análisis de los datos se realizó con el software SPSS v.25. Los resultados señalan que un 89,8% de los estudiantes declaró realizar actividad física tres o más veces por semana, siendo mayor en hombres (χ²=12,823, p=0,012), además, quienes realizan actividad física tienen menos posibilidad de consumir drogas (χ²=9,896, p=0,042); un 11,1% declaró consumir frutas y verduras todos los días, un 65% consume algún alimento chatarra; 84,3% declaró no fumar y un 94,5% consume alcohol de entre 0 a 7 tragos de semanales, sin embargo, un 45,4% usa drogas a menudo, mayormente hombres (χ²=17,203; p=0,002). Un 25% declaró dormir bien siempre, mientras que un 64,8% a veces. Se concluye que los estudiantes tienen un estilo de vida poco saludable, pues, si bien declaran ser físicamente activos, consumir poco alcohol y tabaco, tienen baja ingesta de frutas y verduras a diario, consumen comida chatarra, drogas y tienen insuficiente sueño nocturno
Establishing the global isoscape of leaf carbon in C3 plants through the integrations of remote sensing, carbon, geographic, and physiological information
No full textThe carbon isotope composition (δ13CLeaf) of C3 plant leaves provides valuable information on the carbon-water cycle of vegetation and their responses to climate change within terrestrial ecosystems. However, global applications of δ13CLeaf are hindered by a lack of global long-term spatial maps (isoscapes) that capture vegetation δ13CLeaf variations. The ways in which δ13CLeaf varies over time and across regions are still unknown. In this study, we collected leaf carbon isotope samples across the globe and selected the optimal predictive model from three machine learning algorithms to construct long-term annual global δ13CLeaf isoscapes at a spatial resolution of 0.05° for natural C3 plants between 2001 and 2020. We also assessed the potential of remotely sensed spectral bands, atmospheric CO2 characteristics, geographic, and physiological information to estimate the δ13CLeaf of the global C3 plants. Our results show that the random forest (RF) algorithm can more accurately construct the δ13CLeaf isoscape (R2 = 0.61, Nash Sutcliffe = 0.61, RMSE = 1.21‰, MAE = 0.91‰) than the multilayer perceptron (MLP) and support vector machine (SVM). The inclusion of atmospheric CO2 characteristics, geographical, and physiological information greatly improves prediction compared to relying only on spectral bands. Among the variables, elevation, band 3 spectral reflectance, and solar-induced chlorophyll fluorescence were the three most important variables for constructing the isoscape model, and their relative importance all exceeded 85%. The predicted isoscape revealed strong spatial heterogeneity of δ13CLeaf for C3 plants at a global scale between different continental regions, with enriched values occurring in high-altitude cold and arid regions, and depleted values occurring in warm, humid, or tropical regions. For the first time, we estimated the global depleted rate of δ13CLeaf in C3 plant (−0.0491 ± 0.07 ‰ year−1 from 2001 to 2020). Over the past two decades, 86.49% and 1.00% of global grid cells showed more depleted and more enriched trends in δ13CLeaf of C3 plants, respectively. Our results demonstrated the potential for establishing isoscapes by combining remote sensing, atmospheric CO2 characteristics, physiological, and geographic variables using the RF machine learning algorithm. The isoscape products generated in this study are valuable for assessing carbon-water coupling of terrestrial ecosystems and for improving land surface models
Mangiferin: A comprehensive review on its extraction, purification and uses in food systems
No full textWith the target of fabricating healthier products, food manufacturing companies look for natural-based nutraceuticals that can potentially improve the physicochemical properties of food systems while being nutritive to the consumer and providing additional health benefits (biological activities). In this regard, Mangiferin joins all these requirements as a potential nutraceutical, which is typically contained in Mangifera indica products and its by-products. Unfortunately, knowing the complex chemical composition of Mango and its by-products, the extraction and purification of Mangiferin remains a challenge. Therefore, this comprehensive review revises the main strategies proposed by scientists for the extraction and purification of Mangiferin. Importantly, this review identifies that there is no report reviewing and criticizing the literature in this field so far. Our attention has been targeted on the timely findings on the primary extraction techniques and the relevant insights into isolation and purification. Our discussion has emphasized the advantages and limitations of the proposed strategies, including solvents, extracting conditions and key interactions with the target xanthone. Additionally, we report the current research gaps in the field after analyzing the literature, as well as some examples of functional food products containing Mangiferin
Violence in the school territory: Perception of Chilean Physical Education teachers in training regarding their academic preparation
Get PDFEl objetivo de esta investigación fue conocer el nivel de preparación de los futuros profesores de Educación Física frente a la violencia escolar. Este estudio responde a una metodología cuantitativa, no experimental y de corte transversal, donde se recopilaron datos para conocer la impresión de los futuros docentes mediante un cuestionario online a través de la herramienta Google Forms. La muestra estuvo compuesta por 217 estudiantes de último año de la carrera de Pedagogía en Educación Física de ocho instituciones formadoras chilenas. Los resultados indican que los profesores en formación identifican el bullying como un elemento que impacta negativamente en los aprendizajes de los estudiantes (98,6%), por otro lado, un 55,3% indica que no recibió formación específica para afrontar episodios de violencia escolar (VE). A su vez, el 48,4% indica poseer conocimientos sobre VE y el 60% se siente capacitado para identificar tipos de violencia física y verbal. Se concluye que es fundamental que el itinerario formativo tenga presente los conceptos de convivencia y VE para la formación inicial de profesores
Cyclic behavior of concrete-filled tube columns with bidirectional moment connections considering the local slenderness effect
No full textIn this research, the cyclic behavior of concrete-filled thin tube (CFTT) columns with bidirectional moment connections was numerically studied within the context of thin-walled structures. Novel considerations in the design of CFTT columns with slenderness sections are proposed through a parametric study. A total of 70 high-fidelity finite element (FE) models are developed using ANSYS software v2022 calibrated from experimental research using similar 3D joint configurations. Furthermore, a comparison of different width-to-thickness ratios in columns was considered. The results showed that the models with a high slenderness ratio reached a stable cyclic behavior until 0.03 rad of drift, and a flexural strength of 0.8 Mp was reached for 4% of the drift ratio according to the Seismic Provisions. However, this effect slightly decreased the strength and the dissipated energy of the moment connection in comparison to columns with a high ductility ratio. Moreover, an evaluation of concrete damages shows concrete cracked for cyclic loads higher than 3% of drift. Finally, the joint configurations studied can achieve a good performance, avoiding brittle failure mechanisms and ensuring the plastic hinges in the beams
Observation of Mathematics Classes with the Use of Robots: Design of an Instrument for Guiding Teacher Reflection
Get PDFThe advance of society and technological development have led governments to transform their public policies in various areas, with a particular focus on the education system. In this context, many countries have focused their efforts on raising educational quality standards, especially in the development of digital competencies. This has generated the need to modify school curricula, incorporating Computational Thinking (CT) in areas such as mathematics. Several researches highlight the importance of providing tools to teachers to design meaningful pedagogical strategies that integrate mathematical thinking with CP, implementing innovative teaching practices that favor the development of skills in students. In line with these demands, the present research aims to design an instrument for the observation of mathematics classes that incorporate the PC through the programming of robots, in order to guide teaching reflection. The study is situated within an interpretive paradigm, with a mixed approach, and validates the content from both a quantitative and qualitative perspective. In conclusion, the instrument designed has proven to be a useful tool to guide teacher reflection, as it is structured in six key dimensions and has been validated in terms of clarity, coherence and relevance. However, the need was identified to add additional items to improve the sufficiency of some dimensions. Finally, a second validation process is suggested to ensure its reliability and applicability in different educational contexts
Reference values for 1500-meter run test in Chilean athletes from 35 to 44 years: Cross-sectional study
Get PDFIntroducción: El atletismo es un deporte olímpico que implica superar el rendimiento atlético de los adversarios, cuya realización agrupa un conjunto de disciplinas que conllevan la utilización de diversas destrezas generadas desde la iniciación hasta especialización deportiva.
Objetivo: Desarrollar una escala cualitativa para la valoración del rendimiento atlético en 1500 metros planos en atletas chilenos de entre 35 a 44 años. Material y métodos: Estudio descriptivo transversal, cuya muestra considero 258 atletas máster del género masculino y 186 del género femenino que participaron en la prueba de 1500 metros planos durante el periodo 2014 a 2022, siendo estos datos obtenidos a partir del registro de la Federación de Atletismo Máster de Chile. El rendimiento atlético fue determinado a través del tiempo utilizado para completar la prueba, mientras que la escala cualitativa se construyó con los percentiles <10, ≥10, ≥ 25, ≥ 50, ≥75 correspondiendo estos a los criterios excelente, muy bueno, bueno, regular y pobre.
Resultados: En la prueba de carrera de 1500 metros. La media fue de 5:04:02 y 6:22:62 para el género masculino y femenino, respectivamente. En general, el error estándar de la media = 0:02:67, reportándose diferencias significativas p<0,01 y un tamaño de efecto grande 1,85.
Conclusión: La creación de la escala cualitativa para la prueba de 1500 metros planos permite evaluar y clasificar el nivel deportivo en atletas de entre 35 a 44 años
Non-relativistic limit of the Mielke–Baekler gravity theory
Get PDFIn this paper, we present a generalized nonrelativistic Chern–Simons gravity model in three spacetime dimensions. We first study the non-relativistic limit of the Mielke–Baekler gravity through a contraction process. The resulting non-relativistic theory contains a source for the spatial component of the torsion and the curvature measured in terms of two parameters, denoted by p and q. We then extend our results by defining a Newtonian version of the Mielke–Baekler gravity theory, based on a Newtonian like algebra which is obtained from the non-relativistic limit of an enhanced and enlarged relativistic algebra. Remarkably, in both cases, different known non-relativistic and Newtonian gravity theories can be derived by fixing the (p, q) parameters. In particular, torsionless models are recovered for q = 0