Maximum approximate entropy and r threshold: A new approach for regularity changes detection

Approximate entropy (ApEn) has been widely used as an estimator of regularity in many scientific fields. It has proved to be a useful tool because of its ability to distinguish different system's dynamics when there is only available short-length noisy data. Incorrect parameter selection (embedding dimension $m$, threshold $r$ and data length $N$) and the presence of noise in the signal can undermine the ApEn discrimination capacity. In this work we show that $r_{max}$ ($ApEn(m,r_{max},N)=ApEn_{max}$) can also be used as a feature to discern between dynamics. Moreover, the combined use of $ApEn_{max}$ and $r_{max}$ allows a better discrimination capacity to be accomplished, even in the presence of noise. We conducted our studies using real physiological time series and simulated signals corresponding to both low- and high-dimensional systems. When $ApEn_{max}$ is incapable of discerning between different dynamics because of the noise presence, our results suggest that $r_{max}$ provides additional information that can be useful for classification purposes. Based on cross-validation tests, we conclude that, for short length noisy signals, the joint use of $ApEn_{max}$ and $r_{max}$ can significantly decrease the misclassification rate of a linear classifier in comparison with their isolated use

Energetic study of cardioplegic hearts under ischaemia/reperfusion and [Ca2+] changes in cardiomyocytes of guinea-pig: Mitochondrial role

Abstract Aim: To study the role of mitochondria in the recovery of guinea-pig hearts exposed to high-K+-cardioplegia (CPG) and ischaemia/reperfusion (I/R) Methods: We measured contractility and heat release in perfused guineapig hearts and cytosolic and mitochondrial Ca2+ by epifluorescence and confocal microscopy in isolated cardiomyocytes loaded with Fluo-4 or Rhod-2. Results: In hearts, CPG increased the postischaemic contractile recovery, and this was potentiated by the mNCX blocker clonazepam and the mKATP opener diazoxide, which also prevented the fall in muscle economy. Moreover, CPG prevented the stunning induced by ouabain, which was reduced by clonazepam. In cardiomyocytes, CPG increased fluorescent signals of cytosolic and mitochondrial Ca2+, while the addition of a mNCX blocker (CGP37157) increased cytosolic but reduced mitochondrial [Ca2+]. Ouabain in CPG increased cytosolic Ca2+ and resting heat, but the addition of CGP37157 reduced them, as well as mitochondrial Ca2+. Conclusions: CPG, diazoxide and clonazepam improve postischaemic recovery, respectively, by increasing the Ca2+ cycling and by reducing the mitochondrial Ca2+ uptake either by uniporter or by mNCX. The mitochondria compete with the leaky sarcoplasmic reticulum (SR) as sink of Ca2+ in guinea-pig hearts, affecting the postischaemic contractility. CPG also prevented the ouabain-induced dysfunction by avoiding the Ca2+ overload. Ouabain reduced the synergism between CPG and clonazepam suggesting that [Na+]i and SR load influence the mNCX role.Fil: Ragone, María Inés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas. Cátedra de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Torres, N. S.. Cardiovascular Research And Training Institute; Estados UnidosFil: Consolini, A. E.. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas. Cátedra de Farmacología; Argentin

The Gaia DR2 halo white dwarf population: the luminosity function, mass distribution and its star formation history

We analyze the volume-limited nearly complete 100 pc sample of 95 halo white dwarf candidates identified by the second data release of Gaia. Based on a detailed population synthesis model, we apply a method that relies on Gaia astrometry and photometry to accurately derive the individual white dwarf parameters (mass, radius, effective temperature, bolometric luminosity and age). This method is tested with 25 white dwarfs of our sample for which we took optical spectra and performed spectroscopic analysis. We build and analyse the halo white dwarf luminosity function, for which we find for the first time possible evidences of the cut-off at its faintest end, leading to an age estimate of $\simeq12\pm0.5$Gyr. The mass distribution of the sample peaks at $0.589\,M_{\odot}$, with $71\%$ of the white dwarf masses below $0.6\,M_{\odot}$ and just two massive white dwarfs of more than $0.8\,M_{\odot}$. From the age distribution we find three white dwarfs with total ages above 12 Gyr, of which J1312-4728 is the oldest white dwarf known with an age of $12.41\pm0.22$Gyr. We prove that the star formation history is mainly characterised by a burst of star formation that occurred from 10 to 12 Gyr in the past, but extended up to 8 Gyr. We also find that the peak of the star formation history is centered at around 11 Gyr, which is compatible with the current age of the Gaia-Enceladus encounter. Finally, $13\%$ of our halo sample is contaminated by high-speed young objects (total age<7 Gyr). The origin of these white dwarfs is unclear but their age distribution may be compatible with the encounter with the Sagittarius galaxy.Comment: 15 pages, 9 figures, 2 tables; accepted for publication in MNRA

Caso de estudio para la reconversión sustentable de una finca en la zona centro de Guadalajara, Jalisco, para reutilizarla con vivienda social y comercio

La vivienda en Jalisco enfrenta dos cuestiones opuestas que resultan problemáticas para el sector; mientras ha disminuido el uso habitacional en el centro de la capital, la construcción de nueva vivienda, sobre todo en la periferia, ha aumentado. De acuerdo con el Consejo Estatal de Población, se proyecta que entre 2015 y 2030 se construirán 508 mil viviendas nuevas; sin embargo, en los últimos quince años, la capital registró una migración aproximada de 200 mil habitantes. Se presenta una metodología de análisis base, para la reconversión sustentable de una finca deshabitada en la zona centro de Guadalajara; se muestra como una edificación se puede reutilizar con estrategias de arquitectura bioclimática y contar con distintas tipologías para vivienda social y comercio. Se basó en una investigación, cuyos resultados mostraron que usuarios de vivienda con ecotecnologías, ahorran 72.49% en el pago de servicios, en comparación a usuarios de vivienda sin dichos sistemas.ITESO, A.C

New approach to determine the morphological and structural changes in the enamel as consequence of dental bleaching

Nowadays, there are a number of methods very effectives for the dental bleaching, which are typically strong oxidizing agents, as the hydrogen peroxide, applied directly to the tooth surface. After bleaching, several research studies have been carried out to evaluate the efficacy of bleaching agents on teeth, there being a great controversy concerning the techniques used and their pre-treatment requirements derived, which could alter the final results. In fact, there is a strong necessity to develop different approach to determine the real consequences of bleaching treatment by using an unchangeable and entire tooth. Herein, to evaluate the effects of 38% (p/v) hydrogen peroxide treatment onto morphological, chemical and structural features in the human enamel and dentin, environmental scanning electron microscopy, electron probe micro analyzer and X-ray diffraction techniques have been used. Although such effects have been widely investigated with several techniques, including XRD and SEM, the novelty of this study lies on the techniques and methodology used to characterize the human teeth after bleaching treatment. This approach allows carrying out the analyses without any previous pretreatment, such as powdering, dried or metal sputtering, and its study in the same tooth piece before and after bleaching, which avoids the possible intrinsic differences derived from the use of different pieces. The obtained results display that neither the structural nor the chemical features of both enamel and dentin are altered after bleaching treatment. However, the morphology of the enamel is notably altered, appearing pronounced pores which could affect to the possible bacterial colonization. These findings put an end to the controversies on the different obtained results in the literature of the bleaching effects in the enamel and set standards for future studies

Adsorption of proteins to thin-films of PDMS and its effect on the adhesion of human endothelial cells

This paper describes a simple and inexpensive procedure to produce thin-films of poly(dimethylsiloxane). Such films were characterized by a variety of techniques (ellipsometry, nuclear magnetic resonance, atomic force microscopy, and goniometry) and used to investigate the adsorption kinetics of three model proteins (fibrinogen, collagen type-I, and bovine serum albumin) under different conditions. The information collected from the protein adsorption studies was then used to investigate the adhesion of human dermal microvascular endothelial cells. The results of these studies suggest that these films can be used to model the surface properties of microdevices fabricated with commercial PDMS. Moreover, the paper provides guidelines to efficiently attach cells in BioMEMS devices.Fil: Chumbimuni Torres, Karin Y.. The University of Texas at San Antonio; Estados UnidosFil: Coronado, Ramon E.. The University of Texas at San Antonio; Estados UnidosFil: Mfuh, Adelphe M.. The University of Texas at San Antonio; Estados UnidosFil: Castro Guerrero, Carlos. The University of Texas at San Antonio; Estados UnidosFil: Silva, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Negrete, George R.. The University of Texas at San Antonio; Estados UnidosFil: Bizios, Rena. The University of Texas at San Antonio; Estados UnidosFil: Garcia, Carlos D.. The University of Texas at San Antonio; Estados Unido

Resiliencia, ansiedad y hábitos alimentarios de la población amazónica sur-oriente antes y durante la pandemia: Resilience, anxiety and eating habits of the south-east amazon population before and during the pandemic

Objective:&nbsp;To determine the relationship between resilience, anxiety and eating habits of the south-eastern Amazonian population before and during the pandemic in 2020.&nbsp;Methods:&nbsp;Relational, quantitative and qualitative descriptive, the sample consisted of 150 inhabitants aged 30 to 45 years. The instrument used was the STAI: state-trait anxiety inventory, the data were processed with SPSS-25, analysis of significance and difference of means was performed, non-parametric test and post-test significant differences (Wilcoxon test for related samples ).&nbsp;Results:&nbsp;In adults, State-Trait Anxiety was greater than 65%, a bilateral significance of p = 0.01 was obtained, indicating that anxiety was related to resilience. Food consumption before the pandemic was classified: natural 60%, processed 40% and ultra-processed 0%; During confinement, the consumption of processed foods was 53.33% and ultra-processed 20%. The level of food consumption before and during the pandemic shows a difference, being significant of p &lt;5%. The level of anxiety before and during the pandemic, obtaining a significant of p &lt;5%. Conclusions: State-Trait Anxiety was greater than 65% in adults. Anxiety was related to resilience. There is a significant difference in the type of food consumed, in anxiety levels, before and during the Covid-19 pandemic, in the inhabitants of the South-Eastern Amazon. The consumption of processed and ultra-processed foods, before the pandemic, was 40% and during the pandemic this consumption has increased to 73%, therefore the consumption of food was high in fat and sugar content.Objetivo:&nbsp;Determinar la relación entre la resiliencia, la ansiedad y los hábitos alimentarios de la población amazónica sur-oriente antes y durante la pandemia en el año 2020.&nbsp;Métodos:&nbsp;Descriptivo relacional, cuantitativo y cualitativo, la muestra fue de 150 pobladores amazónicos adultos cuyas edades son de 30 a 45 años. El instrumento utilizado fue el STAI: Inventario de ansiedad estad-rasgo, los datos fueron procesados con SPSS- 25, se realizo análisis de significancia y diferencia de medias, prueba no paramétrica de test y post test diferencias significativas (Prueba de Wilcoxon para muestras relacionadas).&nbsp;Resultados:&nbsp;En los adultos la Ansiedad Estado-Rasgo fue mayor al 65%, se obtuvo una significancia bilateral de p=0,01, indicando que la ansiedad estuvo relacionada con la resiliencia. El consumo de alimentos antes de la pandemia, estuvo clasificado: natural 60%, procesado 40% y ultra procesado 0%; durante el confinamiento, el consumo de alimentos procesados fue 53,33% y ultraprocesados 20%.El nivel consumo de alimentos antes y durante la pandemia, muestra una diferencia, siendo significativa de p &lt;5%. El nivel de ansiedad antes y durante la pandemia, obteniendo una significativa de p &lt;5%.&nbsp;Conclusiones:&nbsp;La Ansiedad Estado-Rasgo fue mayor al 65% en adultos. La ansiedad estuvo relacionada con la capacidad resilente. Existe diferencia significativa en el tipo de alimentos consumidos, en los niveles de ansiedad, antes y durante la pandemia Covid-19, en los pobladores de la Amazonia Sur-Oriente. El consumo de alimentos procesados y ultra procesados, antes de la pandemia, fue del 40% y durante la pandemia este consumo se ha incrementado al 73%, por tanto, el consumo de alimentos se elevó en alto contenido de grasas y azucares

Body mass index, weight, and height percentiles in school-aged children from Mendoza. A comparison with the WHO reference

Introduction. The World Health Organization (WHO) recommends the use of reference tables to monitor the growth pattern and nutritional status of children and adolescents. Body mass index (BMI), weight, and height are the most commonly used variables. The objective of this study was to estimate the BMI, weight, and height percentiles for school-aged children (2009-2011) living in the department of San Rafael (Mendoza) and compare them to the international World Health Organization reference to establish their relevance for the evaluation of the growth pattern and nutritional status of this population. Population and methods. A cross-sectional anthropometric study was conducted in 3448 school-aged children aged 4.00 to 13.49 years. The LMS ChartMarker Pro software was used to estimate the BMIfor- age, weight-for-age, and height-for-age percentiles, by sex and age, and they were compared with the WHO curves. Besides, percentage differences (%D) were calculated to estimate the differences and their statistical significance using the Wilcoxon test. Results. The population of boys and girls in San Rafael showed higher weight and BMI (%D ≈ 7% and 9%, respectively) percentiles, and lower height (%D ≈ 0.8%) values than WHO reference (p < 0.05). Conclusion. The differences found warn about the use of the WHO reference in the school-aged population of San Rafael since it would overestimate the prevalence of overweight, obesity, and chronic malnutrition and underestimate the prevalence of acute and global malnutrition. This situation highlights the importance of having a local reference resource.Fil: Garraza, Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Ontogenia y Adaptación; ArgentinaFil: Gauna, María E.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Ontogenia y Adaptación; ArgentinaFil: Torres, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Ciencias Antropológicas; ArgentinaFil: Navazo, Bárbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Ontogenia y Adaptación; ArgentinaFil: Quintero, Fabián A.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Ontogenia y Adaptación; ArgentinaFil: Bergel Sanchís, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Lanús; Argentina. Centro de Estudios en Nutrición y Desarrollo Infantil; ArgentinaFil: Cesani Rossi, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Ontogenia y Adaptación; Argentin

Nuevas orientaciones en la formación del profesorado para una enseñanza centrada en la promoción del aprendizaje autorregulado de los alumnos

La sociedad del conocimiento demanda una alta capacitación en los alumnos para aprender a aprender y, en consecuencia, un modelo de enseñanza más centrado en el mismo proceso de aprendizaje (learning-centered teaching). En este artículo se trata de explicar que este paradigma exige un profesor que actúe como guía en el proceso de aprendizaje y asuma la postura de “experto-aprendiz” en el aula. Para ello es necesaria una formación docente más acorde con los principios actuales del aprendizaje puesto que, de este modo el profesor estará más capacitado para desempeñar su cambio de rol