Esquemas de prueba en torno al concepto de proporcionalidad en los libros de texto

Además de su valor matemático, la importancia de la demostración desde el punto de vista de la Educación Matemática está ampliamente aceptada. La actividad demostrativa suele reservarse para los cursos superiores (Bachillerato o Universidad) por ser un proceso complejo. Sin embargo, existen numerosos autores que abogan por la introducción de este proceso en etapas previas. Así, Vallejo y Ordóñez (2015) realizan una experiencia con alumnos de 7-8 años que argumentan para justificar una afirmación relacionada con la división de números naturales. Stylianides y Stylianides (2009) consideran, en base a criterios educativos y psicológicos, que es apropiado y razonable introducir la demostración y el razonamiento deductivo en niveles inferiores al instituto

Study of the thermal degradation of bioactive sol-gel coatings for the optimization of its curing process

A set of materials has been prepared by sol-gel process containing different quantities of hydroxyapatite (0, 2.5 and 5% HAp w/w) using as silica precursors glycidyloxypropyltrimethoxysilane (GPTMS) and triethoxyvinylsilane (VTES). In order to optimize the curing process to obtain sintherized systems (inorganic network) or hybrid systems (organic&-inorganic) a TG and FTIR studies have been developed and degradation kinetic triplet parameters were obtained (the activation energy, pre-exponential factor, and function of degree of conversion). The kinetic study was analyzed by means of an integral isoconversional non-isothermal procedure (model free), and the kinetic model was determined by the Coats&-Redfern method and through the compensation effect (IKR). All the systems followed the n = 6 kinetic model. The addition of HAp increases the thermal stability of the systems. The isothermal degradation was simulated from non-isothermal data, and the curing process could be defined to obtain the two types of materials. Temperature under 250 °C allows the formation of hybrids networks.Publicad

The design and characterisation of sol–gel coatings for the controlled-release of active molecules

The controlled release of active agents from a matrix has become increasingly important for oral, transdermal or implantable therapeutic systems, due to the advantages of safety, efficacy and patient convenience. Controlled-release hybrid (organic-inorganic) sol-gel coating synthesis has been performed to create a sol with an active molecule included (procaine). Synthesis procedures included acid-catalysed hydrolysis, sol preparation, the addition of a procaine solution to the sol, and the subsequent gelation and drying. The alkoxide precursors used were triethoxyvinylsilane and tetraethyl-orthosilicate (TEOS) in molar ratios of 1:0, 9:1, 8:2 and 7:3. After the determination of the optimal synthesis parameters, the material was physicochemically characterised by silicon-29 nuclear magnetic resonance (²⁹Si-NMR) and Fourier transform infrared spectroscopy, contact angle analysis and electrochemical impedance spectroscopy tests. Finally, the materials were assayed in vitro for their ability to degrade by hydrolysis and to release procaine in a controlled manner. The sustained release of procaine over a 3-day period was demonstrated. A close correlation between release and degradation rates suggests that film degradation is the main mechanism underlying the control of release. Electrochemical analysis reveals the formation of pores and water uptake during the degradation. The quantity of TEOS is one of the principal parameters used to determine the kinetics of degradation and procaine release.The supports of the Spanish Ministry of Economy and Competitiveness through project IPT-010000-2010-004 and of the University of the Basque Country (UPV/EHU) through ‘‘UFI11/56’’ are kindly acknowledge

Efficacy of Neurofeedback on the Increase of Mindfulness-Related Capacities in Healthy Individuals: a Controlled Trial

Electroencephalogram (EEG) studies of mindfulness have shown it can lead to increases in alpha power, which are similar to those obtained by alpha-based neurofeedback (NF) interventions. It has been hypothesized there may be relationships between mindfulness and NF in terms of the neural pathways through which they induce salutary outcomes. The aim of the study was to evaluate possible changes in mindfulness and cognitive functioning following an alpha-based NF intervention, and the role of alpha power as a mediator of improvements. A controlled, non-randomized, trial with 50 healthy participants was conducted with two experimental conditions: a six-session NF intervention and a waiting-list control group. Both groups were administered mindfulness questionnaires (Mindful Attention Awareness Scale (MAAS), Five Facet Mindfulness Questionnaire (FFMQ)) and cognitive measures (Paced Auditory Serial Addition Task (PASAT)), at pre- and post-test. The NF intervention focused on the up-regulation of upper alpha power. Differences among groups were estimated using ANCOVAs, and mediation assessment through path analyses. Compared to controls, the NF group showed enhanced task-related upper alpha power (effect size (ES) = 1.16, p < 0.001), mindfulness outcomes (MAAS: ES = 0.94, p = 0.004; FFMQ: ES = 1.38, p < 0.001), and a trend of cognitive functioning (PASAT time: ES = 0.59, p = 0.062). Upper alpha power had a mediating effect for cognitive functioning (PASAT errors: indirect effect = 0.81, 95% CI = 0.21–1.85), but not for mindfulness. These results demonstrate the effectiveness of NF for increasing mindfulness in healthy individuals with no previous experience in mindfulness or neurofeedback training, suggesting that NF may be an acceptable method of augmenting mindfulness-related capacities in the general population

Excessive heart rate increase during mild mental stress in preparation for exercise predicts sudden death in the general population

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Notas al pie en la Aritmética (1884) de los Coroneles Salinas y Benítez.

Dentro de la Historia de la Educación Matemática, el análisis de libros de texto antiguos es una importante línea de trabajo y el siglo XIX resulta un periodo de especial interés debido a su proliferación durante esa época. El estudio de ciertos elementos de una obra (prólogos, notas al pie, etc.) proporciona información relevante para los investigadores. Aquí, abordamos el estudio de las notas al pie de una obra de Manuel Benítez y Parodi e Ignacio Salinas y Angulo, dirigida a estudiantes de academias militares. Se detecta una mayor presencia en esta obra que en otras de la época. Al analizarlas por su función y temática, se aprecia que su función más común es plantear digresiones al discurso principal, en muchos casos ofreciendo información sobre aspectos etimológicos e históricos. In the field of History of Mathematics Education, the analysis of old Mathematics textbooks is an important line of work and the 19th century is a particularly interesting period due to its proliferation during that time. The study of certain elements of a work (prefaces, footnotes, etc.) provides relevant information toresearchers. Here, we study the footnotes from a textbook written by Manuel Benitez y Parodi and Ignacio Salinas y Angulo addressed tor military academy students. We detect a higher presence in this book than in others from that time. After analyzing them regarding their functions and themes, we see that their more common role is to digress from the main discourse, often providing information about etymological and historical aspects

Moregrasp: Restoration of Upper Limb Function in Individuals with High Spinal Cord Injury by Multimodal Neuroprostheses for Interaction in Daily Activities

The aim of the MoreGrasp project is to develop a noninvasive, multimodal user interface including a brain-computer interface (BCI) for intuitive control of a grasp neuroprosthesis to support individuals with high spinal cord injury (SCI) in everyday activities. We describe the current state of the project, including the EEG system, preliminary results of natural movements decoding in people with SCI, the new electrode concept for the grasp neuroprosthesis, the shared control architecture behind the system and the implementation of a user-centered design

Estrategias de resolución en un problema sobre probabilidad condicional en la XXIX Olimpiada aragonesa

En el currículo estatal y autonómico aragonés la probabilidad condicional aparece explícitamente en 4.º de ESO. Queda fuera de toda duda que se trata de una de las nociones básicas de probabilidad que todo estudiante de secundaria debería comprender, bien por su importancia e interés en la estocástica, como por los potentes razonamientos informales que se sustentan alrededor de ella (Borovcnick, 2012). Sin embargo, junto con la idea de independencia de sucesos, los problemas asociados a la probabilidad condicional constituyen una fuente habitual para la expresión de sesgos de razonamiento y de dificultades para el alumnado (Batanero, 2014). Por otro lado, como varios elementos sobre los que se construye la idea de probabilidad condicional aparecen desde el comienzo de la secundaria (por ejemplo, tablas o diagramas de árbol), una pregunta que nos podemos plantear es si el alumnado es capaz de desarrollar estrategias intuitivas en situaciones donde aparecen sucesos condicionados. Si esto fuera así, estas estrategias podrían servir de base para el diseño de secuencias didácticas (Martínez-Juste y otros, 2015)..

La sucesión look and say

En esta breve nota queremos presentar las denominadas sucesiones look and say como recurso a la hora de abordar contenidos relacionados con la búsqueda de patrones, así como para plantear pequeñas investigaciones en el aula. El contenido de este artículo viene motivado por la sesión «sucesiones look and say» desarrollada el 4 de Noviembre de 2016 dentro del taller de talento matemático para 4º de la ES

Gravimetric sensors operating at 1.1 GHz based on inclined c-axis ZnO grown on textured Al electrodes

Shear mode solidly mounted resonators (SMRs) are fabricated using an inclined c-axis ZnO grown on a rough Al electrode. The roughness of the Al surface is controlled by changing the substrate temperature during the deposition process to promote the growth of inclined ZnO microcrystals. The optimum substrate temperature to obtain homogeneously inclined c-axis grains in ZnO films is achieved by depositing Al at 100 °C with a surface roughness ~9.2 nm, which caused an inclination angle of ~25° of the ZnO c-axis with respect to the surface normal. Shear mode devices with quality-factors at resonance, Q r and effective electromechanical coupling factors, [Formula: see text], as high as 180 and 3.4% are respectively measured. Mass sensitivities, S m of (4.9 ± 0.1) kHz · cm(2)/ng and temperature coefficient of frequency (TCF) of ~-67 ppm/K are obtained using this shear mode. The performance of the devices as viscosity sensors and biosensors is demonstrated by determining the frequency shifts of water-ethanol mixtures and detection of Rabbit immunoglobin G (IgG) whole molecule (H&L) respectively.The research leading to these results has received funding from the European Community’s Horizon 2020 Programme under Grant Agreement No. SPIRE-01-2014-636820, the IC1208 Cost action, and from the Ministerio de Economía y Competitividad del Gobierno de España through the project MAT2013-45957-R. Financial support from these institutions is therefore gratefully acknowledged. G.R. also wishes to acknowledge funding from the Cambridge Commonwealth, European and International Trust