A justiça social pela educação matemática: tempo de questões ou uma questão de tempo?

A preocupação com o significado das aprendizagens, a sensibilidade pelas desigualdades sociais e um forte sentido de justiça levaram-me a um querer intervir na educação Matemática para ajudar os alunos a tornarem-se cidadãos mais participativos e interventivos na construção de uma sociedade mais justa e equitativa. O querer intervir enquanto professora de Matemática, levou-me a reflectir sobre a relação existente entre a educação Matemática e a justiça social, a relevância da educação Matemática na construção de uma sociedade mais justa e a cultura profissional em educação Matemática que promova a justiça social. Neste âmbito, apresento algumas conclusões da minha reflexão

Learning mathematics and competences: Bringing together three theoretical perspectives

The symposium aims to bring into analysis and discussion a possibility of articulating and integrating theoretical concepts from Activity Theory, Situated Learning and Critical Mathematics Education in order to contribute to understanding learning in practices where mathematics and technology seem to be relevant

Surfactant Interactions with Protein-Coated Surfaces: Comparison between Colloidal and Macroscopically Flat Surfaces

Surface interactions with polymers or proteins are extensively studied in a range of industrial and biomedical applications to control surface modification, cleaning, or biofilm formation. In this study we compare surfactant interactions with protein-coated silica surfaces differing in the degree of curvature (macroscopically flat and colloidal nanometric spheres). The interaction with a flat surface was probed by means of surface plasmon resonance (SPR) while dynamic light scattering (DLS) was used to study the interaction with colloidal SiO2 (radius 15 nm). First, the adsorption of bovine serum albumin (BSA) with both SiO2 surfaces to create a monolayer of coating protein was studied. Subsequently, the interaction of these BSA-coated surfaces with a non-ionic surfactant (a decanol ethoxylated with an average number of eight ethoxy groups) was investigated. A fair comparison between the results obtained by these two techniques on different geometries required the correction of SPR data for bound water and DLS results for particle curvature. Thus, the treated data have excellent quantitative agreement independently of the geometry of the surface suggesting the formation of multilayers of C10PEG over the protein coating. The results also show a marked different affinity of the surfactant towards BSA when the protein is deposited on a flat surface or individually dissolved in solution

Saúde mental, interação mãe-criança e desenvolvimento ao final do primeiro ano de vida

A saúde mental materna pode afetar a qualidade da interação mãe-criança e, consequentemente, o desenvolvimento infantil. Este estudo teve como objetivo avaliar a relação entre interação mãe-filho e o desenvolvimento neuropsicomotor de crianças com um ano de vida, levando em consideração a saúde mental materna. Participaram 65 crianças, usuárias de Unidades de Saúde da Família, e suas mães que responderam a uma entrevista de rastreio para transtorno mental comum. Avaliou-se o desenvolvimento por meio de um teste para rastreamento de risco. A interação foi avaliada pelo Protocolo de Avaliação de Interação Diádica. Apresentaram risco desenvolvimental 43,1% das crianças. Apesar de 44,6% das mães pontuarem para sofrimento psíquico, a saúde mental materna não se associou aos comportamentos interativos. Alguns comportamentos maternos e infantis associaram-se a atrasos desenvolvimentais, mas apenas a estimulação cognitiva mostrou-se preditora de atrasos. Os dados contribuem para compreensão do papel da interação no desenvolvimento infantil.Maternal mental health can affect the quality of the mother-child interaction and, consequently, the development of the child. This study aimed to evaluate the relationship between the mother-child interaction and the neuro-psychomotor development of children at one year of age, taking into consideration the maternal mental health. A total of 65 children, who were registered in Family Health Units, participated, along with their mothers, who responded to a screening interview for common mental disorders. Development was evaluated through a risk screening test. The interaction was assessed through the Dyadic Interaction Assessment Protocol. Developmental risk was presented by 43.1% of the children. Although 44.6% of the mothers presented scores indicative of psychological distress, maternal mental health was not associated with the interactive behaviors. Some maternal and child behaviors were associated with developmental delays, however, only cognitive stimulation was shown to be a predictor of delays. The data contribute to the comprehension of the role of the interaction in child development.La salud mental materna puede afectar la calidad de la interacción madre-hijo y el desarrollo infantil. Este estudio evaluó la relación entre interacción madre-hijo y el desarrollo neuropsicomotor de niños con edad de un año, considerando la salud mental materna. Fueron evaluados 65 niños de un año, usuarios de Unidades de Salud de la Familia, mediante una prueba de detección del riesgo. Las madres fueron entrevistadas y respondieron a instrumento de rastreo psiquiátrico. Se evaluó la interacción mediante un protocolo de interacción diádica. 43,1% de los niños presentó riesgo de desarrollo. Aunque 44,6% de las madres presentó malestar psicológico, su salud mental no se asoció con los comportamientos presentados en la interacción. Sin embargo, comportamientos interactivos de la madre y del niño se asociaron con retraso en el desarrollo. La estimulación cognitiva fue la única variable predictiva de retrasos. Los datos contribuyen para la comprensión del papel de la interacción y el desarrollo infantil

Gold nanoparticles obtained by ns-pulsed laser ablation in liquids (ns-PLAL) are arranged in the form of fractal clusters

Gold nanoparticles (AuNPs), synthesized by ns-pulsed laser ablation in liquid (ns-PLAL) in the absence of any capping agents, are potential model systems to study the interactions with biological structures unencumbered by interference from the presence of stabilizers and capping agents. However, several aspects of the physics behind these AuNPs solutions deserve a detailed investigation. The structure in solution of nsPLAL-synthesized AuNPs was investigated in solution by means of small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS). Furthermore, the (dried) NPs have been examined using TEM. The analysis of the SAXS curve shows the presence of a large number of small aggregates with a fractal structure stabilized by strong long-range repulsive interactions. Fitting of the SAXS curve to a suitable “fractal model” allows the estimation of the features of the fractal including the fractal dimension d = 1.9. The latter allows to estimate the fraction of light scattered by fractals of different sizes and thus permits a fair comparison between the DLS and TEM data. Here, a stable abundant population of fractal clusters is reported reflecting a mechanism where primary AuNPs (size 7.6 nm) are forced to aggregate forming clusters during the collapse of the cavitation bubble. When these clusters are released in the aqueous phase, their large negative charge builds up repulsive interactions that prevent cluster-cluster aggregation imparting colloidal stability

O conceito de crítica em educação matemática e perspectivas de investigação

Este artigo resulta de um estudo mais alargado e em curso onde procuramos relacionar três perspectivas teóricas na elaboração de um quadro teórico de investigação em Educação Matemática. Aqui analisamos uma dessas perspectivas, a Educação Matemática Crítica, oferecendo uma visão da recente linha de investigação, denominada socio-política, que tem sido desenvolvida no campo da Educação Matemática. Desenvolveremos este artigo através da análise do conceito de crítica, terminando com uma breve descrição de quatro linhas de investigação em Educação Matemática nas quais o conceito de crítica é central

Effect of the Surface Chemical Composition and of Added Metal Cation Concentration on the Stability of Metal Nanoparticles Synthesized by Pulsed Laser Ablation in Water

Metal nanoparticles (NPs) made of gold, silver, and platinum have been synthesized by means of pulsed laser ablation in liquid aqueous solution. Independently from the metal nature, all NPs have an average diameter of 10 ± 5 nm. The ζ-potential values are: −62 ± 7 mV for gold, −44 ± 2 mV for silver and −58 ± 3 for platinum. XPS analysis demonstrates the absence of metal oxides in the case of gold and silver NPs. In the case of platinum NPs, 22% of the particle surface is ascribed to platinum oxidized species. This points to a marginal role of the metal oxides in building the negative charge that stabilizes these colloidal suspensions. The investigation of the colloidal stability of gold NPs in the presence of metal cations shows these NPs can be destabilized by trace amounts of selected metal ions. The case of Ag+ is paradigmatic since it is able to reduce the NP ζ-potential and to induce coagulation at concentrations as low as 3 μM, while in the case of K+ the critical coagulation concentration is around 8 mM. It is proposed that such a huge difference in destabilization power between monovalent cations can be accounted for by the difference in the reduction potential

Resumen de HOMO-MEX en Iberlef 2023: Detección de discursos de odio en mensajes online dirigidos hacia la población LGBTQ+ hablante de español mexicano

The detection of hate speech and stereotypes in online platforms has gained significant attention in the field of Natural Language Processing (NLP). Among various forms of discrimination, LGBTQ+ phobia is prevalent on social media, particularly on platforms like Twitter. The objective of the HOMO-MEX task is to encourage the development of NLP systems that can detect and classify LGBTQ+ phobic content in Spanish tweets, regardless of whether it is expressed aggressively or subtly. The task aims to address the lack of dedicated resources for LGBTQ+ phobia detection in Spanish Twitter and encourages participants to employ multi-label classification approaches.La detección de discursos de odio y estereotipos en plataformas en línea ha suscitado gran atención en el campo del Procesamiento del Lenguaje Natural (PLN). Entre las diversas formas de discriminación, la LGBTQ+fobia es frecuente en las redes sociales, especialmente en plataformas como Twitter. El objetivo de la tarea HOMO-MEX es fomentar el desarrollo de sistemas de PLN que puedan detectar y clasificar contenido LGBTQ+fóbico en tuits en español, independientemente de si se expresa de forma agresiva o sutil. La tarea pretende abordar la falta de recursos dedicados a la detección de la fobia LGBTQ+ en Twitter en español y anima a los participantes a emplear enfoques de clasificación multietiqueta.This paper has been supported by PAPIIT projects IT100822, TA101722, and CONAHCYT CF-2023-G-64. Also, we thank Alejandro Ojeda Trueba for the creation of the HOMO-MEX presentation image. GBE is supported by a grant from the Ministry of Universities of the Government of Spain, financed by the European Union, NextGeneration EU (María Zambrano program)

Resumen de PAR-MEX en IberLEF 2022: Tarea Compartida para la Detección de Paráfrasis en Español

Paraphrase detection is an important unresolved task in natural language processing; especially in the Spanish language. In order to address this issue, and contribute to the creation of high-performance paraphrase detection automated systems, we propose a shared task called PAR-MEX. For this task, we created a corpus, in Spanish, with topics in the domain of Mexican gastronomy. Afterwards, the participants in this task submitted their classification results on our corpus. In this paper we explain the steps followed for the creation of the corpus, we summarize the results obtained by the various participants, and propose some conclusions regarding the paraphrase-detection task in Spanish.La detección de paráfrasis es una tarea importante no resuelta en procesamiento del lenguaje natural; especialmente en la lengua española. Para atacar este problema, y para contribuir a la creación de sistemas de detección automática que obtengan resultados competitivos, proponemos la tarea compartida llamada PAR-MEX. Para esto, creamos un corpus en español con temas dentro del campo semántico de gastronomía mexicana. Después los participantes en esta tarea enviaron los resultados de sus sistemas de clasificación sobre nuestro corpus. En este paper explicamos los pasos seguidos para la creación del corpus, resumimos los resultados obtenidos por los participantes, y proponemos algunas conclusiones al respecto de la detección de paráfrasis en español.We acknowledge the support of the projects CONACyT CB A1-S-27780, and DGAPA-UNAM PAPIIT references TA400121 and TA101722