El papel del folding back en el proceso de comprensión del concepto de área : un estudio de caso

Este artículo presenta un estudio de caso en el que pretendemos comprender, desde una perspectiva interpretativa, el proceso de comprensión del concepto de área de una niña de quinto curso de Primaria, Cecilia, en el contexto de una unidad de enseñanza cuya estrategia metodológica es consistente con la resolución de problemas. Abordamos este proceso considerando la teoría dinámica para el crecimiento de la comprensión matemática (Pirie & Kieren, 1994, 1999) como herramienta analítica. El folding back ha emergido como una herramienta conceptual eficaz para asimilar el proceso de comprensión del concepto de área, permitiéndonos identificar los diferentes papeles que ciertos indicadores del concepto han jugado en dicho proceso. Así, para el caso de Cecilia, se han identificado tres tipos diferentes de indicadores para el concepto de área: generadores, impulsores y derivados.This paper presents an interpretatively oriented case study focused on the development of understanding of the concept of area in a fifth year primary student, Cecilia. The methodological context of the study was a teaching unit based on problem solving. Our approach takes into consideration the model of growth in mathematical understanding (Pirie & Kieren, 1994, 1999) as an analytical tool. Particularly, folding back emerged as a powerful tool for understanding the dynamics of Cecilia's growth in understanding the area concept, and enabled us to identify three distinct roles of indicators in her process: generators, drivers and derivative

El papel del folding back en el proceso de comprensión del concepto de área : un estudio de caso

Este artículo presenta un estudio de caso en el que pretendemos comprender, desde una perspectiva interpretativa, el proceso de comprensión del concepto de área de una niña de quinto curso de Primaria, Cecilia, en el contexto de una unidad de enseñanza cuya estrategia metodológica es consistente con la resolución de problemas. Abordamos este proceso considerando la teoría dinámica para el crecimiento de la comprensión matemática (Pirie & Kieren, 1994, 1999) como herramienta analítica. El folding back ha emergido como una herramienta conceptual eficaz para asimilar el proceso de comprensión del concepto de área, permitiéndonos identificar los diferentes papeles que ciertos indicadores del concepto han jugado en dicho proceso. Así, para el caso de Cecilia, se han identificado tres tipos diferentes de indicadores para el concepto de área: generadores, impulsores y derivados.This paper presents an interpretatively oriented case study focused on the development of understanding of the concept of area in a fifth year primary student, Cecilia. The methodological context of the study was a teaching unit based on problem solving. Our approach takes into consideration the model of growth in mathematical understanding (Pirie & Kieren, 1994, 1999) as an analytical tool. Particularly, folding back emerged as a powerful tool for understanding the dynamics of Cecilia's growth in understanding the area concept, and enabled us to identify three distinct roles of indicators in her process: generators, drivers and derivative

Tolerogenic effects of 1,25-dihydroxyvitamin D on dendritic cells involve induction of fatty acid synthesis

The active form of vitamin D, 1,25-dihydroxyvitamin D (1,25D) is a potent regulator of immune function, promoting anti-inflammatory, tolerogenic T cell responses by modulating antigen presentation by dendritic cells (DC). Transcriptomic analyses indicate that DC responses to 1,25D involve changes in glycolysis, oxidative phosphorylation, electron transport and the TCA cycle. To determine the functional impact of 1,25D-mediated metabolic remodelling, human monocyte-derived DC were differentiated to immature (+vehicle, iDC), mature (+LPS, mDC), and immature tolerogenic DC (+1,25D, itolDC) and characterised for metabolic function. In contrast to mDC which showed no change in respiration, itolDC showed increased basal and ATP-linked respiration relative to iDC. Tracer metabolite analyses using (13)C -labeled glucose showed increased lactate and TCA cycle metabolites. Analysis of lipophilic metabolites of (13)C-glucose revealed significant incorporation of label in palmitate and palmitoleate, indicating that 1,25D promotes metabolic fatty acid synthesis in itolDC. Inhibition of fatty acid synthesis in itolDC altered itolDC morphology and suppressed expression of CD14 and IL-10 by these cells. These data indicate that the ability of 1,25D to induce tolerogenic DC involves metabolic remodelling leading to synthesis of fatty acids

The mechanisms of skeletal muscle atrophy in response to transient knockdown of the vitamin D receptor in vivo

Objective Vitamin‐D deficiency is estimated to affect ∼40% of the world's population and has been associated with impaired muscle maintenance. Vitamin‐D exerts its actions through the Vitamin‐D‐receptor (VDR), the expression of which was recently confirmed in skeletal muscle, and its down‐regulation is linked to reduced muscle mass and functional decline. To identify potential mechanisms underlying muscle atrophy, we studied the impact of VDR knockdown (KD) on mature skeletal muscle in vivo, and myogenic regulation in vitro in C2C12 cells. Methods Male Wistar rats underwent in vivo electrotransfer (IVE) to knock down the VDR in hind‐limb tibialis anterior (TA) muscle for 10 days. Comprehensive metabolic and physiological analysis was undertaken to define the influence loss of the VDR on muscle fibre composition, protein synthesis, anabolic and catabolic signalling, mitochondrial phenotype, and gene expression. Finally, in vitro lentiviral transfection was used to induce sustained VDR‐KD in C2C12 cells to analyse myogenic regulation. Results Muscle VDR‐KD elicited atrophy through a reduction in total protein content, resulting in lower myofibre area. Activation of autophagic processes was observed, with no effect upon muscle protein synthesis or anabolic signalling. Furthermore, RNA‐Seq analysis identified systematic down‐regulation of multiple mitochondrial respiration related protein and genesets. Finally, in vitro VDR‐knockdown impaired myogenesis (cell cycling, differentiation and myotube formation). Conclusion Taken together, these data indicate a fundamental regulatory role of the VDR in the regulation of myogenesis and muscle mass; whereby it acts to maintain muscle mitochondrial function and limit autophagy. Joseph Bass completed his PhD in Medicine and Health in 2017 at The University of Nottingham, where he is currently a Research Fellow. Joe is interested in examining the mechanistic regulation of musculoskeletal health, particularly factors impacting muscle atrophy susceptibility.Additional co-authors: Nathaniel J. Szewczyk, Mark E. Cleasby, Philip J. Atherto

The role of folding back in the process of understanding the concept of area: A case study

Este artículo presenta un estudio de caso en el que pretendemos comprender, desde una perspectiva interpretativa, el proceso de comprensión del concepto de área de una niña de quinto curso de Primaria, Cecilia, en el contexto de una unidad de enseñanza cuya estrategia metodológica es consistente con la resolución de problemas. Abordamos este proceso considerando la teoría dinámica para el crecimiento de la comprensión matemática (Pirie & Kieren, 1994, 1999) como herramienta analítica. El folding back ha emergido como una herramienta conceptual eficaz para asimilar el proceso de comprensión del concepto de área, permitiéndonos identificar los diferentes papeles que ciertos indicadores del concepto han jugado en dicho proceso. Así, para el caso de Cecilia, se han identificado tres tipos diferentes de indicadores para el concepto de área: generadores, impulsores y derivados.This paper presents an interpretatively oriented case study focused on the development of understanding of the concept of area in a fifth year primary student, Cecilia. The methodological context of the study was a teaching unit based on problem solving. Our approach takes into consideration the model of growth in mathematical understanding (Pirie & Kieren, 1994, 1999) as an analytical tool. Particularly, folding back emerged as a powerful tool for understanding the dynamics of Cecilia’s growth in understanding the area concept, and enabled us to identify three distinct roles of indicators in her process: generators, drivers and derivative

El papel del folding back en el proceso de comprensión del concepto de área : un estudio de caso

Este artículo presenta un estudio de caso en el que pretendemos comprender, desde una perspectiva interpretativa, el proceso de comprensión del concepto de área de una niña de quinto curso de Primaria, Cecilia, en el contexto de una unidad de enseñanza cuya estrategia metodológica es consistente con la resolución de problemas. Abordamos este proceso considerando la teoría dinámica para el crecimiento de la comprensión matemática (Pirie & Kieren, 1994, 1999) como herramienta analítica. El folding back ha emergido como una herramienta conceptual eficaz para asimilar el proceso de comprensión del concepto de área, permitiéndonos identificar los diferentes papeles que ciertos indicadores del concepto han jugado en dicho proceso. Así, para el caso de Cecilia, se han identificado tres tipos diferentes de indicadores para el concepto de área: generadores, impulsores y derivados.This paper presents an interpretatively oriented case study focused on the development of understanding of the concept of area in a fifth year primary student, Cecilia. The methodological context of the study was a teaching unit based on problem solving. Our approach takes into consideration the model of growth in mathematical understanding (Pirie & Kieren, 1994, 1999) as an analytical tool. Particularly, folding back emerged as a powerful tool for understanding the dynamics of Cecilia's growth in understanding the area concept, and enabled us to identify three distinct roles of indicators in her process: generators, drivers and derivative