Fenómenos relacionados con el uso de metáforas en el discurso del profesor : el caso de las gráficas de funciones

En este artículo comentamos un fenómeno que se observa al analizar el discurso del profesor cuando explica la representación gráfica de funciones en el bachillerato: el profesor usa expresiones que sugieren, entre otras, metáforas del tipo "la gráfica de una función se puede considerar como la traza que deja un punto que se mueve sobre la gráfica". En la primera parte presentamos el marco teórico sobre la interdependencia entre cuerpo y mente propuesto por Lakoff y Núñez. En la segunda comentamos las diferentes metáforas que han estructurado el concepto de gráfica de una función. En la tercera se describe el estudio de un profesor -siguiendo la secuencia: a) grabación en vídeo de la clase; b) entrevista posterior; y c) análisis de las producciones de los alumnos- que muestra que el profesor usa de manera poco consciente estas metáforas y cree que sus efectos en la comprensión de sus alumnos son inocuos. Finalizamos con unas conclusiones en las que se analizan las posibles causas de este fenómeno.In this paper, we comment a phenomenon that is observed when analyzing the teacher's discourse when explaining of the graphical representation of functions at high school: the teacher uses expressions that suggest, among others, metaphors like "The graph of a function can be considered as the trace of a point that moves over the graph". In the first part, we present the theoretical framework about the embodiment of mind proposed by Lakoff and Núñez. In the second part, we comment the different metaphors that have structured the concept of graphic of a function. In the third part we describe the study of a teacher --following the sequence: a) video-recording of a class, b) interviews, c) analysis of the productions of the students-- which shows that the teacher uses these metaphors in a not completely conscious way and that he believes that their effects in the understanding of the students are innocuous. We end up with some conclusions about the possible causes of this phenomenon

É possível identificar indivíduos com comprometimento cognitivo leve e doença de Alzheimer usando uma bateria neuropsicológica de 30 minutos?

CONTEXTO: A diferenciação de pacientes com diagnósticos de demência e de comprometimento cognitivo leve (CCL) pode exigir avaliação neuropsicológica. MÉTODOS: Cento e trinta e um pacientes idosos consecutivos referidos para avaliação (37 controles-clínicos, 41 com CCL amnéstico e 53 com DA possível/provável) foram diagnosticados com bateria neuropsicológica completa, RM e dados clínicos. Todos os resultados foram codificados de forma cega e posteriormente avaliados com parte dos testes para reclassificar indivíduos com CCL, demência ou controles-clínicos. Concordância entre as baterias foi calculada. Utilizamos curvas ROC para estabelecer sensibilidade e especificidade da bateria breve para discriminar: (i) controles-clínicos de um grupo de demência e CCL; (ii) indivíduos com demência daqueles indivíduos sem demência; (iii) controles clínicos daqueles indivíduos com diagnóstico de CCL. Comparamos o desempenho dos três grupos em todas as tarefas da bateria completa. RESULTADOS: Todos os testes neuropsicológicos mostraram diferenças entre controles-clínicos e grupo de demência. A comparação entre CCL e outros grupos mostrou, principalmente, diferenças em tarefas de memória. Concordância entre baterias breve e completa foi substancial (kappa = 0.805). Análises com curvas ROC demonstraram boas sensibilidade e especificidade quando comparados grupos de indivíduos com demência e sem demência (grupos de CCL e DA agrupados) e grupos de controle-clínico de indivíduos com declínio cognitivo (CCL associado à DA). Por outro lado, sensibilidade e especificidade diminuíram consideravelmente para discriminar controles-clínicos de indivíduos com diagnóstico de CCL. CONCLUSÃO: O uso de bateria breve pode não ser recomendado para discriminar controles-clínicos de indivíduos com CCL, porém o uso pode estar indicado para diferenciar grupos de especificidade menor [demência versus não demência ou grupos patológicos (demência e CCL) de grupo não patológicos (controles clínicos)].evaluation. METHODS: One hundred and thirty-one consecutive referred elderly patients (37 clinical-controls, 41 with amnestic MCI and 53 with possible/probable AD) were diagnosed with a comprehensive (full) neuropsychological battery, MRI and clinical data. All of the results were blindly coded and evaluated latter with a subset of the tests to reclassify the subjects as MCI, dementia or clinical-control. Agreement rates between both batteries were calculated. We also used ROC curves to establish the sensitivity and specificity of the brief battery for discriminating (i) clinical-control individuals from a group dementia and MCI patients; (ii) individuals with dementia from individuals without dementia; (iii) clinical-control individuals from a group of MCI. We compared performance of the three groups on all full battery tasks. RESULTS: All neuropsychological tests showed differences between clinical-control and dementia groups. The comparison between MCI and the other groups mainly showed memory differences. Agreement between brief and full batteries was substantial (kappa = 0.805). Analyses with ROC curves showed good sensitivity and specificity to discriminate non-demented (clinical control plus MCI groups) and AD group and also to discriminate clinical-control individuals from individuals with cognitive decline (MCI plus AD group). However, sensitivity and specificity significantly decreased when brief battery was tested to discriminate only normal and MCI diagnosis. DISCUSSION: The use of a brief battery might not be indicated to discriminate MCI and clinical-control individuals, but its use might be adequate to discriminate less specific groups (demented versus non-demented and pathological [dementia and MCI] and non-pathological [clinical-control] groups)

Análisis de los perfiles de corta y larga duración de los turistas de ocio de Barcelona

Este artículo analiza el efecto de la duración de la estancia en relación a los conceptos de motivación, satisfacción, imagen, repetitividad y recomendación. El modelo teórico se basa en la literatura y utiliza una metodología de ecuaciones estructurales a través de un análisis multigrupo. El tamaño de la muestra es de 10,953 encuestas a turistas. Los resultados confirman la mayoría de las hipótesis. Por ejemplo, la imagen tiene un efecto en la repetitividad, recomendación y satisfacción. Además, se encuentran diferencias en los efectos de las variables según los turistas de short y long break

Crisis agrarias, mortalidad y alimentación en la ciudad y territorio de Barcelona, durante la Alta Edad Media

During the Early Middle Ages the city and the area of Barcelona suffered deep agrarian crises which affected large human groups. The study approaches the existing relationship between agrarian landscape, nourishment and mortality, and it comes to the conclusion that, despite its economical and demographical prosperity, the area comprised between the Besòs and Llobregat rivers kept a poor level of nutrition in comparison with other areas in Catalonia.[fr] Pendant le haut moyen âge la ville et le territoire de Barcelone ont souffert de profondes crises agraires qui ont atteint de larges groupes humains. L'on aborde la relation existante entre le paysage agraire, l'alimentation et la mortalité, et l'on arrive à la conclusión que, malgré son caractère de territoire en expansion aussi bien économique que démographique, la zone comprise entre les fleuves Besòs et Llobregat a connu un niveau de nutrition plus déficient que d'autres endroits de la Catalogne

A rational two-step approach to KRAS mutation testing in colorectal cancer using high resolution melting analysis and pyrosequencing

HRM analysis of NRAS codon 61. (TIF 553 kb

An Adaptation of Pavlovian-to-Instrumental Transfer (PIT) Methodology to Examine the Energizing Effects of Reward-Predicting Cues on Behavior in Young Adults

There is growing recognition that much of human behavior is governed by the presence of classically conditioned cues. The Pavlovian-to-Instrumental Transfer (PIT) paradigm offers a way to measure the effects of classically conditioned stimuli on behavior. In the current study, a novel behavioral task, an adaptation of the PIT framework, was developed for use in conjunction with an fMRI classical conditioning task. Twenty-four healthy young adults completed (1) instrumental training, (2) Pavlovian conditioning, and (3) a Transfer test. During instrumental training, participants learned to apply force to a handgrip to win money from slot machines pictured on a computer screen. During Pavlovian conditioning, slot machines appeared with one of two abstract symbols (cues), one symbol was predictive of monetary reward. During the Transfer test, participants again applied force to a handgrip to win money. This time, the slot machines were presented with the Pavlovian cues, but with the outcomes hidden. The results indicated increased effort on the instrumental task, i.e. higher response frequency and greater force, in the presence of the reward-predicting cue. Our findings add to the growing number of studies demonstrating PIT effects in humans. This new paradigm is effective in measuring the effects of a conditioned stimulus on behavioral activation

Kinetics of passivation and pitting corrosion of polycrystalline copper in borate buffer solutions containing sodium chloride

The pitting corrosion of copper in borate buffer containing sodium chloride is studied by using potentiostatic and potentiodynamic techniques complemented with scanning electron microscopy and EDAX. The breakdown potential shifts towards more negative values as the sodium chloride concentration increases. During pitting both soluble Cu(I) and Cu(II) species are detected. The first stage of pitting is explained through the competition between the passive layer formation and the nucleation and growth of the CuCl layer in equilibrium with Cu(I)-chloride complexes in solution. When salt nuclei reach the metal surface, pit growth under charge-transfer control is found. In the following stage the kinetics of pit growth changes to a diffusion controlled process when the thick CuCl layer is completed. Secondary breakdown of the salt layer results in copper dissolution through Cu(II) soluble species. The corresponding overall process is discussed in terms of a sum of nucleation and growth processes. The reaction model reproduces the potentiostatic current transients of copper in weakly alkaline borate buffer containing sodium chloride.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)Facultad de Ciencias Exacta

Kinetics of passivation and pitting corrosion of polycrystalline copper in borate buffer solutions containing sodium chloride

The pitting corrosion of copper in borate buffer containing sodium chloride is studied by using potentiostatic and potentiodynamic techniques complemented with scanning electron microscopy and EDAX. The breakdown potential shifts towards more negative values as the sodium chloride concentration increases. During pitting both soluble Cu(I) and Cu(II) species are detected. The first stage of pitting is explained through the competition between the passive layer formation and the nucleation and growth of the CuCl layer in equilibrium with Cu(I)-chloride complexes in solution. When salt nuclei reach the metal surface, pit growth under charge-transfer control is found. In the following stage the kinetics of pit growth changes to a diffusion controlled process when the thick CuCl layer is completed. Secondary breakdown of the salt layer results in copper dissolution through Cu(II) soluble species. The corresponding overall process is discussed in terms of a sum of nucleation and growth processes. The reaction model reproduces the potentiostatic current transients of copper in weakly alkaline borate buffer containing sodium chloride.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)Facultad de Ciencias Exacta

Altered functional brain connectivity in a non-clinical sample of young adults with attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is characterized by symptoms of inattention and hyperactivity/impulsivity that often persist in adulthood. There is a growing consensus that ADHD is associated with abnormal function of diffuse brain networks, but such alterations remain poorly characterized. Using resting-state functional magnetic resonance imaging, we characterized multivariate (complex network measures), bivariate (network-based statistic), and univariate (regional homogeneity) properties of brain networks in a non-clinical, drug-naive sample of high-functioning young men and women with ADHD (nine males, seven females) and a group of matched healthy controls. Data from our sample allowed the isolation of intrinsic functional connectivity alterations specific to ADHD diagnosis and symptoms that are not related to developmental delays, general cognitive dysfunction, or history of medication use. Multivariate results suggested that frontal, temporal, and occipital cortices were abnormally connected locally as well as with the rest of the brain in individuals with ADHD. Results from the network-based statistic support and extend multivariate results by isolating two brain networks comprising regions between which inter-regional connectivity was significantly altered in the ADHD group; namely, a frontal amygdala-occipital network and a frontal temporal-occipital network. Brain behavior correlations further highlighted the key role of altered orbitofrontal-temporal and frontal-amygdala connectivity for symptoms of inattention and hyperactivity/impulsivity. All univariate properties were similar between groups. Taken together, results from this study show that the diagnosis and the two main symptom dimensions of ADHD are related to altered intrinsic connectivity in orbitofrontal-temporal-occipital and fronto-amygdala-occipital networks. Accordingly, our findings highlight the importance of extending the conceptualization of ADHD beyond segregated fronto-striatal alterations