Representaciones ostensivas que pueden ser activadas en el cálculo de fï(x) : el caso de la función seno.

Resumen de la revista

Correlación entre inteligencia y rendimiento entre adultos de estratos culturales bajos.

Contribuir, aunque de forma modesta, a ensanchar el reducido de las investigaciones experimentales en educación de adultos en España e intentar dar respuesta a preguntas como ¿hay correlación y en qué grado entre la inteligencia y el rendimiento académico de los adultos de estratos culturales bajos? o ¿en qué medida la inteligencia es un factor determinante del éxito en el aprendizaje de los contenidos culturales básicos? y ¿son significativas las diferencias entre sexos y los distintos grupos de edades?. Ciento treinta y ocho individuos mayores de catorce años pertenecientes a cuatro barrios de Salamanca; barrio San José, barrio Pizarrales, barrio Salas Pombo, barrio Garrido y que asistan a Centros de Formación de Adultos para la obtención del Título de Graduado Escolar. Se entregó un cuadernillo para la resolución de problemas y una hoja de respuesta. La corrección se llevó a cabo manualmente ayudados por una plantilla. Se hallaron como medida la tendencia central; la mediana. Como medida de variabilidad la sigma. También se hallaron las puntuaciones X y T. Gráficas, tablas, test de Raven. Existe una correlación significante entre inteligencia y rendimiento. El sexo no parece ser un factor determinante en los resultados de la inteligencia no declina con la edad. El nivel cultural o grado académico poseido por un adulto es relevante para obtener más éxito en las pruebas de inteligencia.

Análisis de los conocimientos geométricos preuniversitarios y su influencia en la formación de los alumnos de las escuelas técnicas.

Se analiza la influencia que el nivel de conocimientos geométricos con que acceden los estudiantes de enseñazas medias a la universidad tienen en el logro de los objetivos académicos. La muestra se consigue a partir de un muestreo probabilístico y causal. Se forma con estudiantes de nuevo ingreso matriculados en primer curso de escuelas técnicas superiores de ingeniería (ETS) y las escuelas universitarias (EU) de la Universidad Politécnica de Madrid, durante los cursos 1990-91/1994-95. 8.025 estudiantes contestaron el cuestionario de dibujo y 2.402 el de matemáticas. Se realiza un examen de la estructuración cualitativa y cuantitativa que el Sistema Educativo de la Ley General de Educación (LGE) de 1970 presenta respecto a los contenidos geométricos preuniversitarios. Se estudia durante cinco años, 1990-94, el nivel de conocimientos geométricos con los que se accede a la universidad. La influencia que puede tener la estructuración de los contenidos geométricos del Plan de Estudios del Sistema Educativo de la LGE de 1970. Se diseña un cuestionario para medir los conocimientos y las capacidades intelectuales del alumnado. Cuestionario. Paquetes estadísticos SPSS/X y Statgraphies. El cuestionario se valida por el coeficiente alfa de Cronbach. Se halla el coeficiente de dificultad y el de discriminación de los items del cuestionario. Los estadísticos utilizados en el análisis de las preguntas son: procentaje de aciertos, fallos o en blanco por áreas: conocimiento (geometría plana, geometría métrica del espacio y geometría descriptiva), actividad mental (informativa operativa y razonamiento) y referencia cronológica (EGB, BUP y COU), y tipos de centros (ETS y EU); media; desviación típica; varianza; y rango de coeficientes y de correlación. El nivel de conocimientos geométricos es inferior al que se considera mínimo necesario para iniciar el estudio de dibujo técnico de primer curso. Esto tiene una influencia negativa tanto en el rendimiento académico como en la consecución de los fines formativos que se persiguen con esta asignatura.

Ortografía fácil.

Material no publicado

Pasado y presente de una postura hispánica.

Repaso de los ideales e intentos imperialistas en la Historia de España desde los tiempos de Alfonso VI. Primero el Imperio peninsular con las herencias de Alfonso VI, después el Imperio mediterráneo obra de la Casa de Aragón, con Sicilia y Atenas, más tarde el Imperio europeo-africano con Alfonso X, y su pretensión al Sacro Imperio Romano Germánico, el Imperio de los Reyes Católicos, que aumenta su grandeza con su nieto Carlos I y continua con sus descendientes. Toda esta sucesión de pretensiones imperialistas son una tradición en España, cuya principal características es que proclamar un imperio es un modo de conseguirlo anticipadamente, por su esencia entusiasta y la fogosidad que infunde en la población, y en esto se basan todas las acciones políticas y propagandísticas.

Publicidad y sexualidad : influencia en grupos de adolescentes.

Los ejemplares con número de Registro x y x no tienen vídeo. Premios Nacionales a la Innovación Educativa, 1998. Anexo Memoria en C-Innov.53

La música en Madrid en la Edad Media y Renacimiento.

Material sin publicar

Espeleotemas de ópalo y pseudocarst granítico

The amorphous silica (opal-A) speleothems associated to the open structural system of granitic rocks where the slow circulation of runoff is produced are mainly the result of the biological degradation of the rock. These speleothems are found in many different geographic, climatic and geological environments though always associated to granitoids. They show two different morphologies: cylindrical or long bodies and laminar or layered forms. They are internally formed by a mass of clasts and spheres of opal-Awith a porous texture that evolves to compact and massive due to the reiteration of the re-dissolution/re-precipitation of the amorphous opal by the water that circulates through it after each rainfall period. A final characteristic of each growth stage (end of rainy period) is the development of whiskers of minerals, normally gypsum, on the water output points of the speleothems. The dimensions of the speleothems are millimetric (length and/or thickness). In this paper their morphology and mineralogy are described based on their study by SEM, XRD and XRF, and there is established a new and more complete genetic hypothesis than the one that exists up to now to understand their formation

The phenology and potential for self-pollination of two Australian monoecious fig species

In this preliminary study, the reproductive phenology of two monoecious fig species, Ficus racemosa and F. rubiginosa, was examined in tropical Australia. Syconia (inflorescences) occurred on both species all year round, but pre-floral and interfloral syconia were much commoner than the wasp-receptive and wasp-emitting phases in both species. The temporal overlap of the wasp-receptive and wasp-emitting phases on a single tree indicated that self-pollination was possible in both species and that pollinators may sometimes persist through multiple generations on one tree. This sexual phase overlap was commoner in F. rubiginosa than in F racemosa. The two species also differed in their general within-tree asynchrony, with a higher diversity of phases on F. rubiginosa than on F. racemosa. The time from syconium initiation to ripening was very similar in F. rubiginosa (mean = 48.51 days) and F. racemosa (mean = 43.53 days). However, there was much more variation within and between trees for F. rubiginosa. In addition, the wasp-receptive phase was found to last up to 5 days (rnean = 4.38) in F. rubiginosa. Such longevity should contribute substantially to local pollinator population persistence. Future work should use genetic studies to determine whether self-pollination is common in these fig species.

Synthesis of heterosulfamates. Search for structure-taste relationships

Thirty one new sodium heterosulfamates, RNHSO3Na, where the R portion contains mainly thiazole, benzothiazole, thiadiazole and pyridine ring structures, have been synthesized and their taste portfolios have been assessed. A database of 132 heterosulfamates ( both open-chain and cyclic) has been formed by combining these new compounds with an existing set of 101 heterosulfamates which were previously synthesized and for which taste data are available. Simple descriptors have been obtained using (i) measurements with Corey-Pauling-Koltun (CPK) space- filling models giving x, y and z dimensions and a volume VCPK, (ii) calculated first order molecular connectivities ((1)chi(v)) and (iii) the calculated Spartan program parameters to obtain HOMO, LUMO energies, the solvation energy E-solv and V-SPART AN. The techniques of linear (LDA) and quadratic (QDA) discriminant analysis and Tree analysis have then been employed to develop structure-taste relationships (SARs) that classify the sweet (S) and non-sweet (N) compounds into separate categories. In the LDA analysis 70% of the compounds were correctly classified ( this compares with 65% when the smaller data set of 101 compounds was used) and in the QDA analysis 68% were correctly classified ( compared to 80% previously). TheTree analysis correctly classified 81% ( compared to 86% previously). An alternative Tree analysis derived using the Cerius2 program and a set of physicochemical descriptors correctly classified only 54% of the compounds.

Semantic organization to enhance active learning based on distributed multimedia educational resources

In order to organize distributed educational resources efficiently, to provide active learners an integrated, extendible and cohesive interface to share the dynamically growing multimedia learning materials on the Internet, this paper proposes a generic resource organization model with semantic structures to improve expressiveness, scalability and cohesiveness. We developed an active learning system with semantic support for learners to access and navigate through efficient and flexible manner. We learning resources in an efficient and flexible manner. We provide facilities for instructors to manipulate the structured educational resources via a convenient visual interface. We also developed a resource discovering and gathering engine based on complex semantic associations for several specific topics.

Components of olive oil and chemoprevention of colorectal cancer

Olive oil contains a vast range of substances such as monounsaturated free fatty acids (e.g., oleic acid), hydrocarbon squalene, tocopherols, aroma components, and phenolic compounds. Higher consumption of olive oil is considered the hallmark of the traditional Mediterranean diet, which has been associated with low incidence and prevalence of cancer, including colorectal cancer. The anticancer properties of olive oil have been attributed to its high levels of monounsaturated fatty acids, squalene, tocopherols, and phenolic compounds. Nevertheless, there is a growing interest in studying the role of olive oil phenolics in carcinogenesis. This review aims to provide an overview of the relationship between olive oil phenolics and colorectal cancer, in particular summarizing the epidemiologic, in vitro, cellular, and animal studies on antioxidant and anticarcinogenic effects of olive oil phenolics.

Some uniform stability and convergence results for integral equations on the real line and projection methods for their solution

The paper considers second kind equations of the form (abbreviated x=y + K2x) in which and the factor z is bounded but otherwise arbitrary so that equations of Wiener-Hopf type are included as a special case. Conditions on a set are obtained such that a generalized Fredholm alternative is valid: if W satisfies these conditions and I − Kz, is injective for each z ε W then I − Kz is invertible for each z ε W and the operators (I − Kz)−1 are uniformly bounded. As a special case some classical results relating to Wiener-Hopf operators are reproduced. A finite section version of the above equation (with the range of integration reduced to [−a, a]) is considered, as are projection and iterated projection methods for its solution. The operators (where denotes the finite section version of Kz) are shown uniformly bounded (in z and a) for all a sufficiently large. Uniform stability and convergence results, for the projection and iterated projection methods, are obtained. The argument generalizes an idea in collectively compact operator theory. Some new results in this theory are obtained and applied to the analysis of projection methods for the above equation when z is compactly supported and k(s − t) replaced by the general kernel k(s,t). A boundary integral equation of the above type, which models outdoor sound propagation over inhomogeneous level terrain, illustrates the application of the theoretical results developed.

Holocene variations in peatland methane cycling associated with the Asian summer monsoon system

Atmospheric methane concentrations decreased during the early to middle Holocene; however, the governing mechanisms remain controversial. Although it has been suggested that the mid-Holocene minimum methane emissions are associated with hydrological change, direct evidence is lacking. Here we report a new independent approach, linking hydrological change in peat sediments from the Tibetan Plateau to changes in archaeal diether concentrations and diploptene delta C-13 values as tracers for methanogenesis and methanotrophy, respectively. A minimum in inferred methanogenesis occurred during the mid-Holocene, which, locally, corresponds with the driest conditions of the Holocene, reflecting a minimum in Asian monsoon precipitation. The close coupling between precipitation and methanogenesis is validated by climate simulations, which also suggest a regionally widespread impact. Importantly, the minimum in methanogenesis is associated with a maximum in methanotrophy. Therefore, methane emissions in the Tibetan Plateau region were apparently lower during the mid-Holocene and partially controlled by interactions of large-scale atmospheric circulation.

Invariants of binary differential equations

In this paper, we study binary differential equations a(x, y)dy (2) + 2b(x, y) dx dy + c(x, y)dx (2) = 0, where a, b, and c are real analytic functions. Following the geometric approach of Bruce and Tari in their work on multiplicity of implicit differential equations, we introduce a definition of the index for this class of equations that coincides with the classical Hopf`s definition for positive binary differential equations. Our results also apply to implicit differential equations F(x, y, p) = 0, where F is an analytic function, p = dy/dx, F (p) = 0, and F (pp) not equal aEuro parts per thousand 0 at the singular point. For these equations, we relate the index of the equation at the singular point with the index of the gradient of F and index of the 1-form omega = dy -aEuro parts per thousand pdx defined on the singular surface F = 0.