¿Cómo funciona un circuito eléctrico?

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Perspectivas filosóficas y psicopedagógicas de la educación moral : la mentira infantil en la adquisición de la conducta moral.

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Las concepciones del aprendizaje de los profesores.

Describe las concepciones generales y específicas que los profesores mantienen acerca de su propio aprendizaje, así como su relación con sus prácticas docentes y también otros constructos, como sus creencias epistemológicas, sus estrategias cognitivas y metacognitivas y su referencia a los valores. 54 profesores, procedentes de 3 universidades, 10 institutos de educación secundaria; expertos y noveles; de 24 especialidades universitarias diferentes. En coherencia con el objetivo de construcción procesual de significados y relaciones, se ha optado por una metodología cualitativa, que no excluye el uso adecuado de los procedimientos estadísticos, especialmente el análisis de conglomerados, las tablas de contingencia y la regresión logística. Entrevista semiestructurada. La obtención y codificación de los datos cualitativos se basó en la fenomenografía (Marton, 1981) y la teoría fundamentada de Glaser y Strauss (Strauss y Corbín, 1990). Para la validación interjueces de la codificación se utilizó el índice de Hambleton-Rovinelli (1984). Partimos de Greeno, Collins y Resnick (1995), que consideran 3 modelos de concepciones del aprendizaje: empirista-conductual, cognitivo y sociohistórico-situado; también del modelo evolutivo de Nyquist y Wulf (en Gilbert y Gibbs, 1998), y de las fases de Kember (1997), entre otros. 1) Sólo los profesores que mantienen la concepción específica reestructuración cognitiva son significativamente estratégico y metacognitivos en su aprendizaje, únicamente los profesores de secundaria 'reestructuradores' poseen las otras cualidades. 2) Son los profesores de secundaria quienes más se adhieren al empirismo. 3) Los universitarios 'multiperspectivistas' son los que hacen más referencia a los valores éticos en el desarrollo de su proyecto docente. 4) Los profesores tienden a ser más objetivistas epistemológicamente, los de ciencias sociales más interactivos estratégicos, metacognitivos y reestructuradores, mientras que los de letras son más multiperspectivistas. 5) Los noveles más centrados en la protección del yo y los expertos más metacognitivos. En definitiva, indaga sobre las concepciones de aprendizaje de los profesores de educación secundaria y universitaria que tienden a descubrir y describir en que consisten las representciones, sus modelos explicativos con sus dimensiones y propiedades. Indaga también la posible asociación del aprendizaje de los profesores con su práctica docente.

Equipar para educadores : adolescentes en situación de conflicto.

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La formación de profesores universitarios : un panorama de las prácticas internacionales, resultados y tendencias.

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Psychometrical properties of the “How I Think” Questionnaire (HIT-Q) in adolescents

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Realizability of Point Processes

There are various situations in which it is natural to ask whether a given collection of k functions, ρ j (r 1,…,r j ), j=1,…,k, defined on a set X, are the first k correlation functions of a point process on X. Here we describe some necessary and sufficient conditions on the ρ j ’s for this to be true. Our primary examples are X=ℝ d , X=ℤ d , and X an arbitrary finite set. In particular, we extend a result by Ambartzumian and Sukiasian showing realizability at sufficiently small densities ρ 1(r). Typically if any realizing process exists there will be many (even an uncountable number); in this case we prove, when X is a finite set, the existence of a realizing Gibbs measure with k body potentials which maximizes the entropy among all realizing measures. We also investigate in detail a simple example in which a uniform density ρ and translation invariant ρ 2 are specified on ℤ; there is a gap between our best upper bound on possible values of ρ and the largest ρ for which realizability can be established.

Dichotomous-choice contingent valuation with 'don't know' responses and misreporting

A new approach is presented that simultaneously deals with Misreporting and Don't Know (DK) responses within a dichotomous-choice contingent valuation framework. Utilising a modification of the standard Bayesian Probit framework, a Gibbs with Metropolis-Hastings algorithm is used to estimate the posterior densities for the parameters of interest. Several model specifications are applied to two contingent valuation datasets: one on wolf management plans, and one on the US Fee Demonstration Program. We find that DKs are more likely to be from people who would be predicted to have positive utility for the bid. Therefore, a DK is more likely to be a YES than a NO. We also find evidence of misreporting, primarily in favour of the NO option. The inclusion of DK responses has an unpredictable impact on willingness-to-pay estimates, since it impacts differently on the results for the two datasets we examine. Copyright (C) 2009 John Wiley & Sons, Ltd.

Very long chain n-3 polyunsaturated fatty acids in the food chain in the UK and the potential of animal-derived foods to increase intake

The very long chain (VLC) n-3 polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are widely recognised to have beneficial effects on human health. However, recommended intakes of VLC n-3 PUFA (450 mg/day) are not being met by the diet in the majority of the population mainly because of low consumption of oil-rich fish. Current mean intake of VLC n-3 PUFA by adults is estimated to be about 282 mg/day with EPA and DHA contributing about 244 mg/day. Furthermore, the fact that only about 27% of adults eat any oil-rich fish (excluding canned tuna) and knowledge of the poor conversion of α-linolenic acid to EPA and DHA in vivo, particularly in men, leads to the need to review current dietary sources of these fatty acids. Animal-derived foods are likely to have an important function in increasing intake and studies have shown that feeding fish oils to animals can increase the EPA and DHA content of the resulting food products. This paper highlights the importance of examining current and projected consumption trends of meat and other animal products when exploring the potential impact of enriched foods by means of altering animal diets. When related to current food consumption data, potential dietary intakes of EPA+DHA from foods derived from animals fed enriched diets are calculated to be about 231 mg/day. If widely consumed, such foods could have a significant impact on progression of conditions such as cardiovascular disease. Consideration is also given to the sources of VLC n-3 PUFA in animal diets, with the sustainability of fish oil being questioned and the need to investigate the use of alternative dietary sources such as those of algal origin.

Current intakes of EPA and DHA in European populations and the potential of animal-derived foods to increase them

The beneficial effects of long-chain (C chain >= 20) n-3 PUFA are well documented and, overall, increased intake reduces risk of CVD. Recent evidence also points to a role in reducing, age-related decline in cognitive function. The two key fatty acids are EPA (20:5) and DHA (22:6), with current UK recommendation for adults being 450 mg EPA + DHA/d. Whilst some EPA and DHA can be synthesised in vivo from alpha-linolenic acid, recent data indicate this source to be very limited, Suggesting that EPA and DHA should be classified as dietary essentials. In many parts of Europe the daily intake of EPA + DHA by adults and especially young adults (18-24 years) is < 100 mg/d, since many never eat oily fish. Poultry meat contributes small but worthwhile amounts of EPA+DHA. Studies to enrich the EPA+DHA content of animal-derived foods mainly use fish oil in the diet of the animal. Recent work has shown that such enrichment has the potential to provide to the UK adult diet a daily intake of EPA+DHA of about 230 mg, with poultry meat providing the largest amount (74 mg). There are. however. concerns that the Continued and possibly increased use of fish oils in animals diets is not Sustainable and alternative approaches are being examined, including the genetic modification of certain plants to allow them to synthesise EPA and DHA from shorter-chain precursors.

Current intakes of EPA and DHA in European populations and the potential of animal-derived foods to increase them

The beneficial effects of long-chain (C chain >= 20) n-3 PUFA are well documented and, overall, increased intake reduces risk of CVD. Recent evidence also points to a role in reducing, age-related decline in cognitive function. The two key fatty acids are EPA (20:5) and DHA (22:6), with current UK recommendation for adults being 450 mg EPA + DHA/d. Whilst some EPA and DHA can be synthesised in vivo from alpha-linolenic acid, recent data indicate this source to be very limited, Suggesting that EPA and DHA should be classified as dietary essentials. In many parts of Europe the daily intake of EPA + DHA by adults and especially young adults (18-24 years) is < 100 mg/d, since many never eat oily fish. Poultry meat contributes small but worthwhile amounts of EPA+DHA. Studies to enrich the EPA+DHA content of animal-derived foods mainly use fish oil in the diet of the animal. Recent work has shown that such enrichment has the potential to provide to the UK adult diet a daily intake of EPA+DHA of about 230 mg, with poultry meat providing the largest amount (74 mg). There are. however. concerns that the Continued and possibly increased use of fish oils in animals diets is not Sustainable and alternative approaches are being examined, including the genetic modification of certain plants to allow them to synthesise EPA and DHA from shorter-chain precursors.

The role of meat as a source of n-3 polyunsaturated fatty acids in the human diet

It is considered that consumption of very long chain (VLC, carbon chain length >= 20) n - 3 PUFAs in most Western populations is sub-optimal and benefits in relation to chronic disease would be gained from increased consumption. This review examines the current contribution that meat makes to dietary intake of VLC n - 3 PUFA and given its current low contribution, how ruminant meat may be enriched. Enrichment both directly with VLC n - 3 fatty acids and indirectly by increasing intake by the animals of alpha-linolenic acid (ALNA; C 18:3 n - 3) are considered. Since it now appears that dietary ALNA is a very limited source of VLC n - 3 PUFA in humans, the indirect route is controversial but since some forages-are rich sources of ALNA this route has many sustainability and environmental attractions. Consideration is also given to the increased concentrations of trans and conjugated fatty acids that will arise from enriching ruminant meat with PUFA.