Un modelo de categorías e indicadores para el análisis de las concepciones del profesor sobre la matemática y su enseñanza

Este trabajo se enmarca dentro de las investigaciones de carácter metodológico. Su aportación fundamental consiste en la presentación de un instrumento para el análisis de las concepciones del profesor sobre la matemática y su enseñanza. Proviene de un modelo teórico que ha sido contrastado con los datos obtenidos a partir de un estudio de casos con nueve profesores de matemáticas que imparten docencia a alumnos de 14 a 18 años. De dicho estudio se presentan, asimismo, las relaciones encontradas entre tales concepciones. Su mayor interés reside en la aportación de un sistema de categorías e indicadores que facilitan una caracterización más detallada del posicionamiento del profesor ante la matemática y su enseñanza. Se realiza, también, una amplia descripción de la metodología empleada en el estudio

Un modelo de categorías e indicadores para el análisis de las concepciones del profesor sobre la matemática y su enseñanza

Este trabajo se enmarca dentro de las investigaciones de carácter metodológico. Su aportación fundamental consiste en la presentación de un instrumento para el análisis de las concepciones del profesor sobre la matemática y su enseñanza. Proviene de un modelo teórico que ha sido contrastado con los datos obtenidos a partir de un estudio de casos con nueve profesores de matemáticas que imparten docencia a alumnos de 14 a 18 años. De dicho estudio se presentan, asimismo, las relaciones encontradas entre tales concepciones. Su mayor interés reside en la aportación de un sistema de categorías e indicadores que facilitan una caracterización más detallada del posicionamiento del profesor ante la matemática y su enseñanza. Se realiza, también, una amplia descripción de la metodología empleada en el estudio

Un modelo cognitivo para interpretar el desarrollo profesional de los profesores de matemáticas. Ejemplificación en un entorno colaborativo

A partir del trabajo de Sfard en relación con las fases de interiorización, condensación y cosificación para explicar los procesos cognitivos referidos al aprendizaje de las matemáticas, realizamos una propuesta de modelo interpretativo del desarrollo profesional. A continuación, analizamos sus características aplicándolo al caso de una maestra participante en un entorno colaborativo de desarrollo profesional, evidenciando de este modo las potencialidades del modelo.Based on Sfard's stages of interiorisation, condensation and reification, which she applies to explain the cognitive processes in relation to the mathematical learning, we propose an interpretative model of professional development. We analyse its features and then the model is applied to the case study of a primary teacher participating in a collaborative project for professional development. This way we show the model's potentialities

Nuclear Receptors in Nonalcoholic Fatty Liver Disease

Nuclear receptors comprise a superfamily of ligand-activated transcription factors that are involved in important aspects of hepatic physiology and pathophysiology. There are about 48 nuclear receptors in the human. These nuclear receptors are regulators of many hepatic processes including hepatic lipid and glucose metabolism, bile acid homeostasis, drug detoxification, inflammation, regeneration, fibrosis, and tumor formation. Some of these receptors are sensitive to the levels of molecules that control lipid metabolism including fatty acids, oxysterols, and lipophilic molecules. These receptors direct such molecules to the transcriptional networks and may play roles in the pathogenesis and treatment of nonalcoholic fatty liver disease. Understanding the mechanisms underlying the involvement of nuclear receptors in the pathogenesis of nonalcoholic fatty liver disease may offer targets for the development of new treatments for this liver disease

Urban Swarms: A new approach for autonomous waste management

Modern cities are growing ecosystems that face new challenges due to the increasing population demands. One of the many problems they face nowadays is waste management, which has become a pressing issue requiring new solutions. Swarm robotics systems have been attracting an increasing amount of attention in the past years and they are expected to become one of the main driving factors for innovation in the field of robotics. The research presented in this paper explores the feasibility of a swarm robotics system in an urban environment. By using bio-inspired foraging methods such as multi-place foraging and stigmergy-based navigation, a swarm of robots is able to improve the efficiency and autonomy of the urban waste management system in a realistic scenario. To achieve this, a diverse set of simulation experiments was conducted using real-world GIS data and implementing different garbage collection scenarios driven by robot swarms. Results presented in this research show that the proposed system outperforms current approaches. Moreover, results not only show the efficiency of our solution, but also give insights about how to design and customize these systems.Comment: Manuscript accepted for publication in IEEE ICRA 201

Mutant huntingtin enhances activation of dendritic Kv4 K+ channels in striatal spiny projection neurons

Huntington\u27s disease (HD) is initially characterized by an inability to suppress unwanted movements, a deficit attributable to impaired synaptic activation of striatal indirect pathway spiny projection neurons (iSPNs). To better understand the mechanisms underlying this deficit, striatal neurons in ex vivo brain slices from mouse genetic models of HD were studied using electrophysiological, optical and biochemical approaches. Distal dendrites of iSPNs from symptomatic HD mice were hypoexcitable, a change that was attributable to increased association of dendritic Kv4 potassium channels with auxiliary KChIP subunits. This association was negatively modulated by TrkB receptor signaling. Dendritic excitability of HD iSPNs was rescued by knocking-down expression of Kv4 channels, by disrupting KChIP binding, by restoring TrkB receptor signaling or by lowering mutant-Htt (mHtt) levels with a zinc finger protein. Collectively, these studies demonstrate that mHtt induces reversible alterations in the dendritic excitability of iSPNs that could contribute to the motor symptoms of HD

Special fast diffusion with slow asymptotics. Entropy method and flow on a Riemannian manifold

We consider the asymptotic behaviour of positive solutions $u(t,x)$ of the fast diffusion equation $u_t=\Delta (u^{m}/m)={\rm div} (u^{m-1}\nabla u)$ posed for x\in\RR^d, $t>0$, with a precise value for the exponent $m=(d-4)/(d-2)$. The space dimension is $d\ge 3$ so that $m<1$, and even $m=-1$ for $d=3$. This case had been left open in the general study \cite{BBDGV} since it requires quite different functional analytic methods, due in particular to the absence of a spectral gap for the operator generating the linearized evolution. The linearization of this flow is interpreted here as the heat flow of the Laplace-Beltrami operator of a suitable Riemannian Manifold (\RR^d,{\bf g}), with a metric ${\bf g}$ which is conformal to the standard \RR^d metric. Studying the pointwise heat kernel behaviour allows to prove {suitable Gagliardo-Nirenberg} inequalities associated to the generator. Such inequalities in turn allow to study the nonlinear evolution as well, and to determine its asymptotics, which is identical to the one satisfied by the linearization. In terms of the rescaled representation, which is a nonlinear Fokker--Planck equation, the convergence rate turns out to be polynomial in time. This result is in contrast with the known exponential decay of such representation for all other values of $m$.Comment: 37 page

Porous medium equation with nonlocal pressure

We provide a rather complete description of the results obtained so far on the nonlinear diffusion equation $u_t=\nabla\cdot (u^{m-1}\nabla (-\Delta)^{-s}u)$, which describes a flow through a porous medium driven by a nonlocal pressure. We consider constant parameters $m>1$ and $0<s<1$, we assume that the solutions are non-negative, and the problem is posed in the whole space. We present a theory of existence of solutions, results on uniqueness, and relation to other models. As new results of this paper, we prove the existence of self-similar solutions in the range when $N=1$ and $m>2$, and the asymptotic behavior of solutions when $N=1$. The cases $m = 1$ and $m = 2$ were rather well known.Comment: 24 pages, 2 figure

Factors of educational inclusion to improve learning: Teachers' perspectives

In elementary school, inclusive education should be adapted to the needs of students with special abilities in areas such as recreational activities, feedback and methodologies and planning. The objective of the research is to analyze and describe the perspectives of educational inclusion factors among elementary school teachers to improve students’ learning with special abilities. The methodology of the research is descriptive with a quantitative correlational approach in which 823 elementary school teachers participated through a voluntary and anonymous online survey with a measurement instrument that had two dimensions of eight and ten items which were optimal in the different statistical tests as in the analysis of the reliability factors of Cronbach’s alpha (0. 968). The result shows that teachers are willing to improve the curriculum plan, provide specialized attention after training. There is a high perspective to interact with students with special abilities to improve student learning. There are institutional constraints on primary education teachers to improve the learning factors of inclusive education as well as unknown applications or technologies that can help the learning of students with special abilities in primary education. There are non-governmental organizations that seek the welfare of students with special abilities but the results are not very encouraging due to a lack of financial capacity