Comprensión de textos : una constatación crucial entre el modelo proposicional de Kintsch y colaboradores y el modelo de memoria de Sanford y Garrod.

Dentro de un marco psicolingüístico, se plantea una contrastación empírica que permita determinar si en la comprensión de textos el factor decisivo es la estructura proposicional del texto o la estructura de memoria del sujeto. N = 108 estudiantes de Psicología de todos los niveles, curso de adaptación y licenciados (18 y 30 años). Asignación aleatoria a los grupos experimentales. Dos diseños: a) Experimental: intrasujeto 2x3 (presencia-ausencia de argumentos comunes en dos segmentos consecutivos de un texto y presencia-ausencia de indicadores de que liciten un escenario); tres valores: ausencia de indicadores, indicadores de escenario facilitador e indicadores de escenario obstaculizador. Variables dependientes: tiempo de lectura. b) Correlacional: intersujeto. Variables predictoras: representación proposicional, recuperación MLP, representación sobre contenidos mnésicos y recuperación de escenarios de la MLP. Variable criterio: tiempo de lectura. Distribución en 6 grupos (n=18) y aplicación de la prueba (lectura de 30 textos, 12 textos intergrupo constantes (correlacional), 12 intergrupo variables (experimental) y 6 intergrupo constantes (mixto) que actúan como control). Pruebas experimentales ad hoc: selección de 30 textos diseñados según cruce de variables utilizadas. Diseño experimental: ANOVA de dos factores. Correlacional: correlación múltiple. Verificación de los textos de control: línea base. W de Kendall. Correlación de Pearson. Diferencias de medias. Ecuaciones de transformación de puntuaciones. Normalidad: Lilliefords. Homogeneidad de varianzas: Bartlett. Intercomparaciones: Scheffe. En el ANOVA resulta un efecto significativo del factor de coherencia postulado por Sanford y Garrod. Por otro lado, ambos modelos obtienen valores predictivos muy similares. Aunque otros resultados indican una superioridad del segundo modelo. Se observa que el efecto obstaculizador de un escenario es cuatro veces superior a su efecto facilitador (relación asimétrica). Se observan diferencias entre sujetos lentos y rápidos debidas a la facilidad para recuperar información de la memoria. Se destaca la adecuada validez convergente de los experimentos, aunque ciertos defectos metodológicos limitan la generalización de resultados y la variabilidad de éstos sea grande. Cabe concluir que los procesos cognitivos implicados en la comprensión de textos operan sobre contenidos de la memoria (modelo de Stanford y Garrod) y no sobre la representación proposicional de los textos (modelo de Kintsch).

Un modelo estocástico de planificación para la universidad española.

Se persigue crear leyes matemáticas que describan la evolución de la variable: número de alumnos que acuden a la universidad. Conocer de qué manera se puede controlar la cantidad de sujetos que se situan dentro del Sistema Educativo universitario y, una vez encontradas estas leyes, comprobar empíricamente su validez. Alumnos matriculados desde 1966-67 al 1974-75 y abandono desde 1969-70 al 1974-75 de las Facultades de Ciencias, Filosofía y Letras y Medicina de la Universidad de Granada; Facultades de Filosofía y Letras, Medicina, Derecho y Ciencias de la Universidad de Sevilla y Derecho, Filosofía y Letras y Ciencias de la Universidad de Murcia. El trabajo consta de dos partes, en la primera se trata de buscar funciones matemáticas que describan la evolución del alumnado basándose en los factores entrada en el sistema, estancia en él y abandono. Para estudiar el mecanismo de entrada se conocen el número de alumnos que se incorporan en la universidad en cada tiempo 't' y la distribución de dichas llegadas en los diferentes niveles, para cada 't'. El mecanismo de estancia queda determinado por el conocimiento de los cambios que se producen a lo largo del tiempo. El individuo tendrá 3 alternativas: permanecer en el mismo nivel, pasar al superior o abandonar. La distribución de las entradas se considerará como un proceso que puede ser estacionario y la variable aleatoria que cuantifique este proceso será un vector aleatorio con tantos componentes como niveles constituyen el sistema. El posterior análisis empírico que se realiza en la segunda parte recoge y utiliza las fórmulas halladas. La teoría desarrollada nos permite crear un control de entrada de sujetos en diversos niveles; de estancia en esos niveles y el estudio del abandono total del sistema. En el estudio empírico se ha aplicado la teoría desarrollada a las diversas facultades, objeto de análisis, planteando el sistema de ecuaciones en las incógnitas, número de transiciones entre cursos en los distintos años y que se deduce de que un individuo sólo tiene las tres alternativas apuntadas: entrada, estancia y abandono. En todo el análisis se han tenido en cuenta a la hora de estimar las matrices de transición su estacionamiento, siguiendo los trabajos de Bartlett, Hoel y Anderson y Godman. Es un modelo estocástico basado en estudios hechos por diversos autores y referidos a los más diversos temas, como movilidad laboral (Silcock), duración de una huelga (Lancaster). Los autores hacen mención de la importancia que hay que dar al hecho de que se esté trabajando con sujetos humanos a la hora de establecer un control de entradas en la universidad y que, por ejemplo, una política de promoción fijada de antemano puede dar lugar a consecuencias poco deseables para la estructura de la organización educativa. Los controles que apuntan como deseables, serían el control de pérdidas del sistema, control de promociones y control de entradas, en dos vertientes, tamaño y magnitud de las entradas y otro, localización de dichas entradas. No obstante hay que decir que estas variables están ligadas entre sí y cualquier cambio en una afectará a las demás.

Evaluación de un programa experimental de entrenamiento cognitivo-social para profesores en formación.

Mejorar la formación inicial de los maestros, aportando datos sobre la posibilidad de entrenar las destrezas cognitivo-sociales. Comprobar la eficacia de un programa dirigido a incrementar la adecuación de la cognición social de los maestros en formación, en función del impacto que esta cognición ostenta sobre el desarrollo infantil. Ayudar a los sujetos a conocer sus mecanismos perceptivos y a corregir los sesgos presentes en el procesamiento de la información social. Hacer prominentes las características de los alumnos. Planteamiento de hipótesis. 4 grupos naturales de alumnos de centros universitarios de Educación, que cursaban el primer año de la titulación de Maestro en las especialidades de educación infantil y educación primaria. Se opta por un diseño cuasiexperimental de cuatro grupos (uno experimental, uno de control interno y dos de control externo) con dos medidas pretest y dos postest, 6 variables dependientes y 16 hipótesis operativas. La obtención de datos se realiza mediante la observación de secuencias de interacción infantil en escenarios escolares y las consiguientes respuestas a un cuestionario. Se aplica el programa diseñado al grupo experimental. Utilizan las siguientes variables: 1. Independientes; tipo de grupo, atractivo físico de los niños y niñas-estímulo, sexo, tipo de niño o niña (prominente-no prominente), 2. Dependientes; favorabilidad de las heteropercepciones, favorabilidad de las autopercepciones, favorabilidad de las expectativas, tipo de atribución, ponderación estímulo-escala, frecuencia de constructos interpersonales positivos.. Programa de entrenamiento cognitivo-social. Técnicas inferenciales intergrupo, programa statview, pruebas t, pruebas de homoscedasticidad de Bartlett, chi cuadrado, tests de Fisher y Scheffé, pruebas z. 1. El programa de entrenamiento no logra modificar sustancialmente el funcionamiento cognitivo-social de los sujetos. Simultáneamente, éste demuestra una cierta eficacia en la modificación de algunos aspectos relacionados con las teorías implícitas de personalidad de los profesores en formación. 2. Los cambios esquemáticos parciales sugieren un control de determinados procesos cognitivos. 3. El metapensamiento se manifiesta como un fenómeno posible y -lo que es más importante en el ámbito profesional docente- conveniente cuando se trata de ajustar las teorías y motivos a la realidad infantil en función de los objetivos educativos.

The bond scheme

Under the bond scheme, a pre-determined series of payments would compensate farmers for lost revenues resulting from policy change. Unlike the Single Payment Scheme, payments would be fully decoupled: recipients would not have to retain farmland, or remain in agriculture. If vested in a paper asset, the guaranteed, unencumbered, income stream would be similar to that from a government bond. Recipients could exchange this for a capital sum reflecting the net present value of future payments, and reinvest in other business ventures, either on- or offfarm.With a finite, declining flow of payments, budget expenditure would reduce, releasing funds for other uses.

Evaluation of forest snow processes models (SnowMIP2)

Thirty‐three snowpack models of varying complexity and purpose were evaluated across a wide range of hydrometeorological and forest canopy conditions at five Northern Hemisphere locations, for up to two winter snow seasons. Modeled estimates of snow water equivalent (SWE) or depth were compared to observations at forest and open sites at each location. Precipitation phase and duration of above‐freezing air temperatures are shown to be major influences on divergence and convergence of modeled estimates of the subcanopy snowpack. When models are considered collectively at all locations, comparisons with observations show that it is harder to model SWE at forested sites than open sites. There is no universal “best” model for all sites or locations, but comparison of the consistency of individual model performances relative to one another at different sites shows that there is less consistency at forest sites than open sites, and even less consistency between forest and open sites in the same year. A good performance by a model at a forest site is therefore unlikely to mean a good model performance by the same model at an open site (and vice versa). Calibration of models at forest sites provides lower errors than uncalibrated models at three out of four locations. However, benefits of calibration do not translate to subsequent years, and benefits gained by models calibrated for forest snow processes are not translated to open conditions.

Landscape gene flow, coexistence and threshold effect: The case of genetically modified herbicide tolerant oilseed rape (Brassica napus)

Globally there have been a number of concerns about the development of genetically modified crops many of which relate to the implications of gene flow at various levels. In Europe these concerns have led the European Union (EU) to promote the concept of 'coexistence' to allow the freedom to plant conventional and genetically modified (GM) varieties but to minimise the presence of transgenic material within conventional crops. Should a premium for non-GM varieties emerge on the market, the presence of transgenes would generate a 'negative externality' to conventional growers. The establishment of maximum tolerance level for the adventitious presence of GM material in conventional crops produces a threshold effect in the external costs. The existing literature suggests that apart from the biological characteristics of the plant under consideration (e.g. self-pollination rates, entomophilous species, anemophilous species, etc.), gene flow at the landscape level is affected by the relative size of the source and sink populations and the spatial arrangement of the fields in the landscape. In this paper, we take genetically modified herbicide tolerant oilseed rape (GM HT OSR) as a model crop. Starting from an individual pollen dispersal function, we develop a spatially explicit numerical model in order to assess the effect of the size of the source/sink populations and the degree of spatial aggregation on the extent of gene flow into conventional OSR varieties under two alternative settings. We find that when the transgene presence in conventional produce is detected at the field level, the external cost will increase with the size of the source area and with the level of spatial disaggregation. on the other hand when the transgene presence is averaged among all conventional fields in the landscape (e.g. because of grain mixing before detection), the external cost will only depend on the relative size of the source area. The model could readily be incorporated into an economic evaluation of policies to regulate adoption of GM HT OSR. (c) 2007 Elsevier B.V. All rights reserved.

Quantifying the effect of buffer zones, crop areas and spatial aggregation on the externalities of genetically modified crops at landscape level

The development of genetically modified (GM) crops has led the European Union (EU) to put forward the concept of 'coexistence' to give fanners the freedom to plant both conventional and GM varieties. Should a premium for non-GM varieties emerge in the market, 'contamination' by GM pollen would generate a negative externality to conventional growers. It is therefore important to assess the effect of different 'policy variables'on the magnitude of the externality to identify suitable policies to manage coexistence. In this paper, taking GM herbicide tolerant oilseed rape as a model crop, we start from the model developed in Ceddia et al. [Ceddia, M.G., Bartlett, M., Perrings, C., 2007. Landscape gene flow, coexistence and threshold effect: the case of genetically modified herbicide tolerant oilseed rape (Brassica napus). Ecol. Modell. 205, pp. 169-180] use a Monte Carlo experiment to generate data and then estimate the effect of the number of GM and conventional fields, width of buffer areas and the degree of spatial aggregation (i.e. the 'policy variables') on the magnitude of the externality at the landscape level. To represent realistic conditions in agricultural production, we assume that detection of GM material in conventional produce might occur at the field level (no grain mixing occurs) or at the silos level (where grain mixing from different fields in the landscape occurs). In the former case, the magnitude of the externality will depend on the number of conventional fields with average transgenic presence above a certain threshold. In the latter case, the magnitude of the externality will depend on whether the average transgenic presence across all conventional fields exceeds the threshold. In order to quantify the effect of the relevant' policy variables', we compute the marginal effects and the elasticities. Our results show that when relying on marginal effects to assess the impact of the different 'policy variables', spatial aggregation is far more important when transgenic material is detected at field level, corroborating previous research. However, when elasticity is used, the effectiveness of spatial aggregation in reducing the externality is almost identical whether detection occurs at field level or at silos level. Our results show also that the area planted with GM is the most important 'policy variable' in affecting the externality to conventional growers and that buffer areas on conventional fields are more effective than those on GM fields. The implications of the results for the coexistence policies in the EU are discussed. (C) 2008 Elsevier B.V. All rights reserved.

The importance of the relationship between scale and process in understanding long-term DOC dynamics

Concentrations of dissolved organic carbon have increased in many, but not all, surface waters across acid impacted areas of Europe and North America over the last two decades. Over the last eight years several hypotheses have been put forward to explain these increases, but none are yet accepted universally. Research in this area appears to have reached a stalemate between those favouring declining atmospheric deposition, climate change or land management as the key driver of long-term DOC trends. While it is clear that many of these factors influence DOC dynamics in soil and stream waters, their effect varies over different temporal and spatial scales. We argue that regional differences in acid deposition loading may account for the apparent discrepancies between studies. DOC has shown strong monotonic increases in areas which have experienced strong downward trends in pollutant sulphur and/or seasalt deposition. Elsewhere climatic factors, that strongly influence seasonality, have also dominated inter-annual variability, and here long-term monotonic DOC trends are often difficult to detect. Furthermore, in areas receiving similar acid loadings, different catchment characteristics could have affected the site specific sensitivity to changes in acidity and therefore the magnitude of DOC release in response to changes in sulphur deposition. We suggest that confusion over these temporal and spatial scales of investigation has contributed unnecessarily to the disagreement over the main regional driver(s) of DOC trends, and that the data behind the majority of these studies is more compatible than is often conveyed.

Modelling the likely impact of healthy eating guidelines on agricultural production and land use in England and Wales

Quadratic programming techniques were applied to household food consumption data in England and Wales to estimate likely changes in diet under healthy eating guidelines, and the consequences this would have on agriculture and land use in England and Wales. The first step entailed imposing nutrient restrictions on food consumption following dietary recommendations suggested by the UK Department of Health. The resulting diet was used, in a second step as a proxy for demand in agricultural commodities, to test the impact of such a scenario on food production and land use in England and Wales and the impacts of this on agricultural landscapes. Results of the diet optimisation indicated a large drop in consumption of foods rich in saturated fats and sugar, essentially cheese and sugar-based products, along with lesser cuts of fat and meat products. Conversely, consumption of fruit and vegetables, cereals, and flour would increase to meet dietary fibre recommendations. Such a shift in demand would dramatically affect production patterns: the financial net margin of England and Wales agriculture would rise, due to increased production of high market value and high economic margin crops. Some regions would, however, be negatively affected, mostly those dependent on beef cattle and sheep production that could not benefit from an increased demand for cereals and horticultural crops. The effects of these changes would also be felt in upstream industries, such as animal feed suppliers. While arable dominated landscapes would be little affected, pastoral landscapes would suffer through loss of grazing management and, possibly, land abandonment, especially in upland areas.

On the regulation of spatial externalities: coexistence between GM and conventional crops in the EU and the 'newcomer principle'

Pollen-mediated gene flow is one of the main concerns associated with the introduction of genetically modified (GM) crops. Should a premium for non-GM varieties emerge on the market, ‘contamination’ by GM pollen would generate a revenue loss for growers of non-GM varieties. This paper analyses the problem of pollen-mediated gene flow as a particular type of production externality. The model, although simple, provides useful insights into coexistence policies. Following on from this and taking GM herbicide-tolerant oilseed rape (Brassica napus) as a model crop, a Monte Carlo simulation is used to generate data and then estimate the effect of several important policy variables (including width of buffer zones and spatial aggregation) on the magnitude of the externality associated with pollen-mediated gene flow.

A closed paramagnetic electron-precise cluster

A pentametallic cluster is formed by addition of two [SnR2][R = CH(SiMe3)2] groups to [Os3(CO)8(µ-H)(C6H4PhPCH2PPh2)], in a reaction reversing the ortho-hydrogen abstraction and giving the first closed electron-precise paramagnetic cluster.

Provider diversity in the English NHS: a study of recent developments in four local health economies

Objectives: The overall objective of the research was to assess the impact of provider diversity on quality and innovation in the English NHS. The aims were to map the extent of diverse provider activity, identify the differences in performance between Third Sector Organisations (TSOs), for-profit private enterprises, and incumbent organisations within the NHS, and the factors that affect the entry and growth of new private and TSOs. Methods: Case studies of four Local Health Economies (LHEs). Data included: semi-structured interviews with 48 managerial and clinical staff from NHS organizations and providers from the private and Third Sector; some documentary evidence; a focus group with service users; and routine data from the Care Quality Commission and Companies House. Data collection was mainly between November 2008 and November 2009. Results: Involvement of diverse providers in the NHS is limited. Commissioners’ local strategies influence degrees of diversity. Barriers to the entry for TSOs include lack of economies of scale in the bidding process. Private providers have greater concern to improve patient pathways and patient experience, whereas TSOs deliver quality improvements by using a more holistic approach and a greater degree of community involvement. Entry of new providers drives NHS Trusts to respond by making improvements. Information sharing diminishes as competition intensifies. Conclusions: There is scope to increase the participation of diverse providers in the NHS, but care must be taken not to damage public accountability, overall productivity, equity and NHS providers (especially acute hospitals, which are likely to remain in the NHS) in the process.

Provider diversity in the NHS: impact on quality and innovation

The overall objective of the research project has been to assess the impact of provider diversity on quality and innovation in the NHS. The specific research aims were to identify the differences in performance between non-profit Third Sector organisations, for-profit private enterprises, and incumbent public sector institutions within the NHS as providers of health care services, as well as the factors that affect the entry and growth of new private and Third Sector providers. The study used both qualitative and quantitative methods based on case studies of four Local Health Economies (LHEs). Qualitative methods included documentary analysis and interviews with key informants and managers of both commissioning and provider organisations. To provide a focus to the study, two tracer conditions were followed: orthopaedic surgery and home health care for frail older people. In the case of hospital inpatient care, data on patient characteristics were also collected from the HES database. The analysis of this data provided preliminary estimates of the effects of provider type on quality, controlling for client characteristics and case mix. In addition, a survey of patient experience in diverse provider organisations was analysed to compare the different dimensions of quality of provision of acute services between incumbent NHS organisations and new independent sector treatment centres. The research has shown that, in respect of inpatient hospital services, diverse providers supply health services of at least as good quality as traditional NHS providers, and that there is ample opportunity to expand their scale and scope as providers of services commissioned by the NHS. The research used patient experience survey data to investigate whether hospital ownership affects the quality of services reported by NHS patients in areas other than clinical quality. The raw survey data appear to show that private hospitals provide higher quality services than the public hospitals. However, further empirical analysis leads to a more nuanced understanding of the performance differences. Firstly, the analysis shows that each sector offers greater quality in certain specialties. Secondly, the analysis shows that differences in the quality of patients’ reported experience are mainly attributable to patient characteristics, the selection of patients into each type of hospital, and the characteristics of individual hospitals, rather than to hospital ownership as such. Controlling for such differences, NHS patients are on average likely to experience a similar quality of care in a public or privately-run hospital. Nevertheless, for specific groups of patients and for specific types of treatments, especially the more straightforward ones, the private sector provides an improved patient experience compared to the public sector. Elsewhere, the NHS continues to provide a high quality service and outperforms the private sector in a range of services and for a range of clients.

Healthcare providers in the English National Health Service: public, private or hybrids?

In recent years it has been noted that boundaries between public and private providers of many types of welfare have become blurred. This paper uses three dimensions of publicness to analyse this blurring of boundaries in relation to providers of healthcare in England. The authors find that, although most care is still funded and provided by the state, there are significant additional factors in respect of ownership and social control which indicate that many English healthcare providers are better understood as hybrids. Furthermore, the authors raise concerns about the possible deleterious effects of diminishing aspects of publicness on English healthcare. The most important of these is a decrease in accountability