Un estudio de caso para analizar cómo ayudan los profesores en resolución de problemas matemáticos

Hay investigaciones que sostienen que influyen otras dimensiones además de las creencias respecto a la Matemática, Enseñanza de las Matemáticas y Aprendizaje de las Matemáticas en la actuación de profesores. Creemos que algunas de estas dimensiones pueden ser la idea de ayuda, de dificultad y comunicación que se usa con los alumnos. Analizamos con detalle una clase de la profesora Silvia para inferir cómo actúa en función de estas dimensiones. Para el análisis usamos la transcripción de una de sus clases con detalle. A través de este estudio perfilamos unos estilos en cuanto a las dimensiones estudiadas de algunos profesores españoles y, establecemos hipótesis de posibles inconsistencias de la profesora

Un estudio de caso para analizar cómo ayudan los profesores en resolución de problemas matemáticos

Hay investigaciones que sostienen que influyen otras dimensiones además de las creencias respecto a la Matemática, Enseñanza de las Matemáticas y Aprendizaje de las Matemáticas en la actuación de profesores. Creemos que algunas de estas dimensiones pueden ser la idea de ayuda, de dificultad y comunicación que se usa con los alumnos. Analizamos con detalle una clase de la profesora Silvia para inferir cómo actúa en función de estas dimensiones. Para el análisis usamos la transcripción de una de sus clases con detalle. A través de este estudio perfilamos unos estilos en cuanto a las dimensiones estudiadas de algunos profesores españoles y, establecemos hipótesis de posibles inconsistencias de la profesora.Some investigations point out that, besides beliefs on mathematics and on mathematics teaching and learning, other dimensions’ influence teachers’ performance. Amongst these dimensions, we place the ideas of help, difficulty and communication, which is used with the students. One class by Silvia (a secondary teacher) is analyzed in detail in order to know how she performs against these dimensions. For this analysis we use the full transcription of the class. This study allows us to outline some styles in teaching of Spanish teachers depending on the studied dimensions. We also established hypothesis of possible inconsistencies in the performance of Silvia

Striatal synaptic bioenergetic and autophagic decline in premotor experimental parkinsonism

Synaptic impairment might precede neuronal degeneration in Parkinson’s disease. However, the intimate mechanisms altering synaptic function by the accumulation of presynaptic α-synuclein in striatal dopaminergic terminals before dopaminergic death occurs, have not been elucidated. Our aim is to unravel the sequence of synaptic functional and structural changes preceding symptomatic dopaminergic cell death. As such, we evaluated the temporal sequence of functional and structural changes at striatal synapses before parkinsonian motor features appear in a rat model of progressive dopaminergic death induced by overexpression of the human mutated A53T α-synuclein in the substantia nigra pars compacta, a protein transported to these synapses. Sequential window acquisition of all theoretical mass spectra proteomics identified deregulated proteins involved first in energy metabolism and later, in vesicle cycling and autophagy. After protein deregulation and when α-synuclein accumulated at striatal synapses, alterations to mitochondrial bioenergetics were observed using a Seahorse XF96 analyser. Sustained dysfunctional mitochondrial bioenergetics was followed by a decrease in the number of dopaminergic terminals, morphological and ultrastructural alterations, and an abnormal accumulation of autophagic/endocytic vesicles inside the remaining dopaminergic fibres was evident by electron microscopy. The total mitochondrial population remained unchanged whereas the number of ultrastructurally damaged mitochondria increases as the pathological process evolved. We also observed ultrastructural signs of plasticity within glutamatergic synapses before the expression of motor abnormalities, such as a reduction in axospinous synapses and an increase in perforated postsynaptic densities. Overall, we found that a synaptic energetic failure and accumulation of dysfunctional organelles occur sequentially at the dopaminergic terminals as the earliest events preceding structural changes and cell death. We also identify key proteins involved in these earliest functional abnormalities that may be modulated and serve as therapeutic targets to counterbalance the degeneration of dopaminergic cells to delay or prevent the development of Parkinson’s disease.This study was funded by the Instituto de Salud Carlos III through the projects PI14/00763 and PI19/01915 (co-funded by ERDF/ESF, ‘Investing in your future’). L.M.-G. held a Predoctoral Research Fellowship from the University of the Basque Country (UPV/EHU). T.R.-C. and A.Q.-V. were funded by CIBERNED. T.R.-C. held a Fundación Jesús de Gangoiti Barrera Foundation grant (Bilbao, Spain). H.J.-U. and A.B.-I. held a Predoctoral Research Fellowship from the Government of the Basque Country. Israel Science Foundation (536/19) and the Spanish Ministry of Science (SAF2016-78071-R) funded the contribution of S.K. and A.O

A nationwide monitoring of atmospheric microplastic deposition

8 Pág.Plastic production continues to increase every year, yet it is widely acknowledged that a significant portion of this material ends up in ecosystems as microplastics (MPs). Among all the environmental compartments affected by MPs, the atmosphere remains the least well-known. Here, we conducted a one-year simultaneous monitoring of atmospheric MPs deposition in ten urban areas, each with different population sizes, economic activities, and climates. The objective was to assess the role of the atmosphere in the fate of MPs by conducting a nationwide quantification of atmospheric MP deposition. To achieve this, we deployed collectors in ten different urban areas across continental Spain and the Canary Islands. We implemented a systematic sampling methodology with rigorous quality control/quality assurance, along with particle-oriented identification and quantification of anthropogenic particle deposition, which included MPs and industrially processed natural fibres. Among the sampled MPs, polyester fibres were the most abundant, followed by acrylic polymers, polypropylene, and alkyd resins. Their equivalent sizes ranged from 22 μm to 398 μm, with a median value of 71 μm. The particle size distribution of MPs showed fewer large particles than expected from a three-dimensional fractal fragmentation pattern, which was attributed to the higher mobility of small particles, especially fibres. The atmospheric deposition rate of MPs ranged from 5.6 to 78.6 MPs m-2 day-1, with the higher values observed in densely populated areas such as Barcelona and Madrid. Additionally, we detected natural polymers, mostly cellulosic fibres with evidence of industrial processing, with a deposition rate ranging from 6.4 to 58.6 particles m-2 day-1. There was a positive correlation was found between the population of the study area and the median of atmospheric MP deposition, supporting the hypothesis that urban areas act as sources of atmospheric MPs. Our study presents a systematic methodology for monitoring atmospheric MP deposition.The authors acknowledge the support provided by Spanish Network of Plastics in the Environment, EnviroPlaNet (www.enviroplanet.net) and the financial support provided by the Spanish Government, Ministerio de Ciencia e Innovación, grants PID2020-113769RB-C21/C22. The authors would like to thank the Interdepartmental Investigation Research Service of the Universidad Autónoma de Madrid (SIDI-UAM and Segainvex) for the use of their infrastructures and their technical support. J.G.S. thanks ACIISI for the contract from the Viera y Clavijo program at the University of La Laguna (85 % co-financed by the European Social Fund).Peer reviewe

Evolutionary Analyses of Entire Genomes Do Not Support the Association of mtDNA Mutations with Ras/MAPK Pathway Syndromes

BACKGROUND: There are several known autosomal genes responsible for Ras/MAPK pathway syndromes, including Noonan syndrome (NS) and related disorders (such as LEOPARD, neurofibromatosis type 1), although mutations of these genes do not explain all cases. Due to the important role played by the mitochondrion in the energetic metabolism of cardiac muscle, it was recently proposed that variation in the mitochondrial DNA (mtDNA) genome could be a risk factor in the Noonan phenotype and in hypertrophic cardiomyopathy (HCM), which is a common clinical feature in Ras/MAPK pathway syndromes. In order to test these hypotheses, we sequenced entire mtDNA genomes in the largest series of patients suffering from Ras/MAPK pathway syndromes analyzed to date (n = 45), most of them classified as NS patients (n = 42). METHODS/PRINCIPAL FINDINGS: The results indicate that the observed mtDNA lineages were mostly of European ancestry, reproducing in a nutshell the expected haplogroup (hg) patterns of a typical Iberian dataset (including hgs H, T, J, and U). Three new branches of the mtDNA phylogeny (H1j1, U5b1e, and L2a5) are described for the first time, but none of these are likely to be related to NS or Ras/MAPK pathway syndromes when observed under an evolutionary perspective. Patterns of variation in tRNA and protein genes, as well as redundant, private and heteroplasmic variants, in the mtDNA genomes of patients were as expected when compared with the patterns inferred from a worldwide mtDNA phylogeny based on more than 8700 entire genomes. Moreover, most of the mtDNA variants found in patients had already been reported in healthy individuals and constitute common polymorphisms in human population groups. CONCLUSIONS/SIGNIFICANCE: As a whole, the observed mtDNA genome variation in the NS patients was difficult to reconcile with previous findings that indicated a pathogenic role of mtDNA variants in NS

Suma

Resumen del autorSe trata de una exposición de las dificultades y contradicciones de la aplicación sistemática de la metodología de resolución de problemas con alumnos de primero y tercero de BUP durante el curso 1992-93, y durante el primer y segundo trimestre con alumnos de segundo de BUP. Además de dar una descripción de los problemas con que se encuentra el profesorado, se analizan sus causas y se presentan posibles soluciones. Se termina enumerando las múltiples ventajas de esta metodología.AragónES

Relaciones entre actuaciones de alumnos y profesores de Matemáticas en ambientes de resolución de problemas, creencias y concepciones respecto de dimensiones relacionadas con el esfuerzo desde la teoría de la inteligencia creadora

En esta tesis hemos investigado creencias y concepciones respecto a algunas dimensiones como el esfuerzo, ayuda al alumno, la dificultad, el reto, el sufrimiento, la duda, la voluntad, el lenguaje con uno mismo y el sentido ético de nuestras acciones, todo ello analizado desde la perspectiva de Teoría de la inteligencia creadora de José Antonio Marina. Para ello hemos usado un marco teórico que se fundamenta en dos: en la serie de estudios de Schoenfeld y de la Teoría de la inteligencia creadora de Marina, teoría que parte de una definición potente de inteligencia que va desde la cognición hasta la ética. Para el Diseño de investigación hemos usado como paradigma el interpretativo, apoyándonos en la estrategia etnográfica con los alumnos y el estudio de casos en la profesora .. Los resultados nos han confirmado que las dimensiones estudiadas influyen en las actuaciones de alumnos ante un problema, observando conexiones de estas dimensiones con las fases de resolución de un problema. Con respecto a la profesora hemos detectado conexiones entre las dimensiones y los planes de acciones que la profesora llevará adelante en una clase.In this thesis we have concentrated on the beliefs and conceptions with repect to sorne aspects such as effort, assistance to the student, difficulty, challenge, suffering, doubt, will, self language and the ethical sense of our actions. All of these have been analyzed from the perspective ofthe Creative Intelligence Theory by José Antonio Marina. Our theoretical framework is founded on a series of works by Schoenfeld, who established five factors that affect problem solving, and in the Creative Intelligence Theory by Marina. For the research design we have used an interpretative paradigm, based on an etnographic strategy with students and case studies on the teacher' s si de. The results confmn that the investigated aspects affect students' performance when facing a problem. We also observed that these aspects are connected to the problem solving phases. As far as the teacher is concerned we have observed cotll)ections in between the aspects and the action plans that the teacher will carry out in a class

Mathematical problem solving through the lens of ethics and Aristotelian attitude: A case study

Producción CientíficaAttitudes are central to the affective domain in mathematics. However, we still have a long way to go to reach a clear consensus on the characterization of such construct and its operationalization, as there are a wide variety of intertwined approaches depending on the theoretical framework that accompanies each of them. In this article, we explore the idea of incorporating ethics as part of a new characterization of attitude in problem solving contexts by means of an instrumental case study consisting of a key informant 10th grade student. Data were collected via classroom observations, questionnaires, semi-structured interviews and written productions. Results were analyzed using the lens of Aristotelian Ethics and the Theory of Creative Intelligence and show how happiness, responsibility and strength are key concepts that help to describe and understand the way the student behaves when solving mathematical problems. We conclude that besides the traditional attention paid to attitudes towards math, it is worth directing our attention towards attitudes influenced by ethics and personal affect as a whole

Cómo se esfuerzan los alumnos en resolución de problemas matemáticos (I)

En este artículo tratamos cómo la forma en que los alumnos se esfuerzan influye a la hora de resolver problemas matemáticos. Para analizar cómo los alumnos se esfuerzan nos centramos en tres dimensiones: su atención, el lenguaje con ellos mismos o habla interior y cómo afrontan el reto, y para ello usamos un marco teórico que podría enmarcarse en las ideas de las habilidades ejecutivas como parte de la inteligencia. Lo hacemos con un estudio de casos de una alumna de 4º de ESO, Sísifo. El estudio nos refleja que su forma de esforzarse está influyendo en sus fracasos a la hora de resolver problemas

Cómo se Esfuerzan los Alumnos en Resolución de Problemas Matemáticos (I)

Boletim de Educação Matemática, vol. 28, núm. 48, pp. 149-168En este artículo tratamos cómo la forma en que los alumnos se esfuerzan influye a la hora de resolver problemas matemáticos. Para analizar cómo los alumnos se esfuerzan nos centramos en tres dimensiones: su atención, el lenguaje con ellos mismos o habla interior y cómo afrontan el reto, y para ello usamos un marco teórico que podría enmarcarse en las ideas de las habilidades ejecutivas como parte de la inteligencia. Lo hacemos con un estudio de casos de una alumna de 4º de ESO, Sísifo. El estudio nos refleja que su forma de esforzarse está influyendo en sus fracasos a la hora de resolver problemas