Pre-service teachers develop their mathematical knowledge for teaching using manipulative materials in mathematics

This manuscript aims to describe aspects of mathematical knowledge for teaching, MKT, identified in pre-service teachers (PSTs) when explaining an arithmetic property using manipulative materials. In particular, we are interested in the specialized mathematical knowledge, SCK, the pedagogical knowledge related to teaching, KCT, and the knowledge of content and curriculum, KCC. We proposed to record a video to a sample of 27 primary education students enrolled in their first mathematics education course. They had to explain an arithmetic property of natural numbers using manipulative materials. PSTs do not create contexts by the mere presence of manipulative material, but only rely on it for visual purposes; the meaning of these values are modified during the explanation. Evidence has been found of difficulties relating to the SCK such as the inadequate varying of the meanings given to the manipulative material, and to the KCC such as the selecting of an unsuitable material

Math Anxiety in Primary Education during Covid-19 Confinement: Influence on Age and Gender

Background: The closure of schools in Spain due to the Covid-19 pandemic confronted teachers, students, and families with a new reality. Previous studies have shown that anxiety levels increase during pandemic times. Therefore, it highlights the interest of the affective domain in primary education. Objectives: To analyse some general aspects of math anxiety, such as primary school students’ fear, nervousness, and blockage before mathematics both at the educational centre and at home during the Covid-19 confinement. Design: Quantitative study using a closed questionnaire of seven questions with a Likert-type scale. Settings and participants: 496 Spanish primary school students. Data collection: Through the questionnaire hosted in Google Forms and provided by the teachers responsible for the students one month after the closure of all the educational centres and the confinement of all the participating children. Results: Fear of math increases during primary education, with the highest levels of fear and restlessness in the third and sixth grades; the girls presented the highest levels in all aspects, except for nervousness during classes. Conclusions: The general aspects of math anxiety are intimately linked and evolve increasingly throughout primary education. These facts are justified based on the proximity of the change in the educational stage and its influence on teaching, as well as the students’ social conditions

Uso de tecnología en el aprendizaje de geometría con grupos de riesgo: un enfoque discursivo

Tomando el aprendizaje como participación en prácticas discursivas, presentamos un estudio sobre el aprendizaje de la Geometría en clases de secundaria con alumnado en situación de riesgo social. Bajo el supuesto del uso de la tecnología como promotor de participación, se diseñó e implementó una secuencia didáctica en un entorno de geometría dinámica. En el análisis de casos de estudiantes se consideraron aspectos cognitivos, afectivos e instrumentales de modo integrado. En este informe se ilustran dos resultados derivados del desarrollo de un caso. Por un lado, la dificultad por definir la noción de incentro se asocia a un uso del entorno informático poco significativo matemáticamente. Por otro, el rechazo a la exposición pública en la pizarra digital interactiva se asocia a la experiencia de dificultades en procesos de pensamiento matemático

Effects of Copper and/or Cholesterol Overload on Mitochondrial Function in a Rat Model of Incipient Neurodegeneration

Copper (Cu) and cholesterol (Cho) are both associated with neurodegenerative illnesses in humans and animals models. We studied the effect in Wistar rats of oral supplementation with trace amounts of Cu (3 ppm) and/or Cho (2%) in drinking water for 2 months. Increased amounts of nonceruloplasmin-bound Cu were observed in plasma and brain hippocampus together with a higher concentration of ceruloplasmin in plasma, cortex, and hippocampus. Cu, Cho, and the combined treatment Cu + Cho were able to induce a higher Cho/phospholipid ratio in mitochondrial membranes with a simultaneous decrease in glutathione content. The concentration of cardiolipin decreased and that of peroxidation products, conjugated dienes and lipoperoxides, increased. Treatments including Cho produced rigidization in both the outer and inner mitochondrial membranes with a simultaneous increase in permeability. No significant increase in Cyt C leakage to the cytosol was observed except in the case of cortex from rats treated with Cu and Cho nor were there any significant changes in caspase-3 activity and the Bax/Bcl2 ratio. However, the Aβ(1–42)/(1–40) ratio was higher in cortex and hippocampus. These findings suggest an incipient neurodegenerative process induced by Cu or Cho that might be potentiated by the association of the two supplements.Fil: Arnal, Nathalie. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Castillo, Hector Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Tacconi, Maria Josefa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Marra, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata ; Argentin

Design of van Hiele’s level 5 indicators using the Delphi methodology

MICINN project PID2019-104964GB-I00 group S60_20R

La actividad docente de un profesor: geometría, tecnología y grupos de riesgo

En este informe se presentan algunos de los resultados de una investigación de tesis doctoral (Arnal, 2013) sobre el diseño, la implementación y la evaluación de una situación escolar de enseñanza y aprendizaje de la Geometría en un entorno tecnológico con alumnado de secundaria. En un informe anterior (Arnal y Planas, 2013) se documentaron dos resultados sobre aprendizaje derivados de la construcción del caso de un alumno. Ahora documentamos dos resultados sobre la actividad docente de un profesor. Por un lado, indicamos el efecto del uso de un programa de geometría dinámica en la superación parcial de percepciones limitadoras sobre la capacidad matemática de una alumna. Por otro, señalamos las reticencias ante el aprovechamiento del entorno tecnológico en el apoyo de la participación matemática de los alumnos

A Characterization of Van Hiele’s Level 5 of Geometric Reasoning Using the Delphi Methodology

The Van Hiele model of geometric reasoning establishes five levels of development, from level 1 (visual) to level 5 (rigor). Despite the fact that this model has been deeply studied, there are few research works concerning the fifth level. However, there are some works that point out the interest of working with activities at this level to promote the acquisition of previous levels. Our goal is to describe this level through the construction and validation of a list of indicators for each of the processes involved in geometrical reasoning (definition, proof, classification, and identification). Due to the lack of previous research, we have decided to use the Delphi methodology. This approach allowed us to collect information from a panel of experts to reach a consensus through a series of phases about the indicators that describe each of the processes. The final product of the iterative application of this method is a list of validated indicators of the fifth Van Hiele level of reasoning. In particular, proof and definition processes have turned out to be the most relevant processes at this level

Análisis de progresos y dificultades en tareas de identificación del rombo en educación primaria con GeoGebra

Se detectan dificultades de aprendizaje del concepto de rombo en el último curso de Educación Primaria. Como respuesta a las mismas se diseña una intervención didáctica con GeoGebra y se investiga su validez mediante una metodología cuantitativa y cualitativa, atendiendo a la tasa de éxito en la identificación de figuras y a las justificaciones presentadas. Se observa una clara mejora en la adquisición del concepto aplicado a la identificación de rombos, aunque poco sostenida en el tiempo y limitada por algunos obstáculos didácticos. También se concluye que las actividades favorecen una cierta transición de la identificación mediante la comparación con la imagen conceptual a la utilización de la definición

Electrosynthesis and Spectroscopic Characterization of Poly( o

This review, which is divided into three parts, concerns electrochemical synthesis, spectroscopic characterization, and formation mechanisms of poly(o-aminophenol) (POAP) film electrodes. The first part of this review is devoted to describe the electropolymerization process of o-aminophenol on different electrode materials and in different electrolyte media by employing both potentiodynamic and potentiostatic methods. The second part refers to spectroscopic studies carried out by different authors to both, identify the products of the o-aminophenol electrooxidation and elucidate the chemical structure of poly(o-aminophenol) film electrodes. The third part shows the different mechanisms formulated to interpret the POAP films formation from both acid and basic solutions of o-AP. Also, some electrochemical and spectroscopic data which allowed to propos the corresponding formation mechanisms, especially in basic media, are described.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Watercore in Apple Landraces (Malus domestica Borkh.) as a quality indicator

Watercore is the presence of a vitrified texture intruded in the pulp of the fruit. It is found in fruits from different genus and families; and it has been studied in apples. Watercore was described, in apples, as a texture with differential sensorial characteristics in relationship with the ordinary pulp, and its presence is currently considered a defect in apple production, causing economic losses. In this study, it is described as a dichotomous descriptor. We analysed 641 apples from a region belonging to Central Spain (Guadarrama mountain range and the close Tagus Basin River); it was found that around 30% of those apples shown this characteristic, being practically all of them from landraces. Studies related to traditional cultivars do not analyze such characteristic, considered up today as a defect. Nevertheless, we discuss that watercore can have some potential as it gives to apple a distinct appearance and aroma, all of them of value in differential quality and international seal protection. As a result, we conclude our preliminary analysis that it is highly recommended to take into consideration watercore as a descriptor in apple characterizations