Edexcel 360science. Students' book extension units for GCSE Biology, GCSE Chemistry and GCSE Physics : Edexcel's own course for the new specification.

El objetivo de este recurso es involucrar y estimular a los alumnos a conocer cómo funciona la ciencia y les ayuda a adquirir habilidades prácticas y capacidades analíticas básicas para desarrollar las preguntas de evaluación. La publicación está dividida en seis bloques, cada uno cuenta con dieciocho secciones de dos páginas. Al final de cada bloque hay un conjunto de preguntas para practicar los exámenes y glosario de palabras clave. Incluye CD-ROM.

Understanding GCSE geography for AQA specification A.

Este recurso esta orientado al curso de Geografía del General Certificate Secondary Education (GCSE) en la especificación A y su contenido refuerza los temas estudiados en la etapa 3 (key stage 3) de secundaria y desarrolla nuevos temas e ideas de geografía. También, proporciona una base sólida para los niveles avanzados A /AS.

Understanding GCSE geography for AQA specification A. Teacher guide.

Esta guía forma parte del curso de Geografía del General Certificate Secondary Education (GCSE) en la especificación A y ayuda a los profesores a planificar las clases y cumplir con los requisitos exigidos en el curso. Incluye notas para los profesores, hojas de trabajo diferenciadas para los alumnos que pueden personalizarse, así como orientación para la evaluación de control y fichas para anotar los resultados del trabajo de campo.

Tomorrow's geography for Edexcel GCSE specification A.

Su contenido cubre las cuatros unidades de la especificación A de Edexcel: habilidades geográficas y desafíos del planeta; el entorno natural y el entorno humano corresponden a las unidades dos y tres y son opcionales; y la unidad cuatro es la investigación en geografía, con la evaluación de control. Permite a los estudiantes aplicar sus conocimientos y habilidades geográficos a algunas de las cuestiones fundamentales a las que se enfrenta el planeta en el siglo XXI.

Tomorrow's geography for Edexcel GCSE specification A : revision guide. Unit 2 : the natural environment.

Esta guía de revisión ofrece el contenido completo de la unidad 2 de la especificación A para el examen del General Certificate Secondary Education (GCSE) por el organismo Edexcel. Incluye consejos de los examinadores sobre el estilo de preguntas y sobre la preparación del examen.

Tomorrow's geography for Edexcel GCSE specification A. Teacher's resource pack.

Este recurso para el profesor, que completa al libro del alumno, incluye hojas de trabajo para fotocopiar con actividades planteadas para pruebas de comprensión, de capacidades y de aplicación de conocimientos. También, algunas de ellas requieren la utilización de tecnologías de la información y la comunicación (TIC) y de Internet para temas de investigación; así como otras fomentan el manejo y la creación de estadísticas a través de gráficos y diagramas y la aplicación del National Literacy Strategy en la etapa clave 4 (key stage 4).

Vermunt's learning styles : searching for portuguese college student's functioning. 'Estilos de aprendizaje de Vermunt : en busca del funcionamiento de los estudiantes portugueses en la educación superior'.

Resumen basado en el de la publicación

Searching for the perfect surface area normalizing term - a comparison of BET surface area-, geometric surface area- and mass-normalized dissolution rates of anorthite and biotite

Dissolution rates were calculated for a range of grain sizes of anorthite and biotite dissolved under far from equilibrium conditions at pH 3, T = 20 degrees C. Dissolution rates were normalized to initial and final BET surface area, geometric surface area, mass and (for biotite only) geometric edge surface area. Constant (within error) dissolution rates were only obtained by normalizing to initial BET surface area for biotite. The normalizing term that gave the smallest variation about the mean for anorthite was initial BET surface area. In field studies, only current (final) surface area is measurable. In this study, final geometric surface area gave the smallest variation for anorthite dissolution rates and final geometric edge surface area for biotite dissolution rates. (c) 2005 Published by Elsevier B.V.

Effects of carbon dioxide on the searching behaviour of the root-feeding clover weevil Sitona lepidus (Coleoptera : Curculionidae)

The respiratory emission of CO2 from roots is frequently proposed as an attractant that allows soil-dwelling insects to locate host plant roots, but this role has recently become less certain. CO2 is emitted from many sources other than roots, so does not necessarily indicate the presence of host plants, and because of the high density of roots in the upper soil layers, spatial gradients may not always be perceptible by soil-dwelling insects. The role of CO2 in host location was investigated using the clover root weevil Sitona lepidus Gyllenhall and its host plant white clover (Trifolium repens L.) as a model system. Rhizochamber experiments showed that CO2 concentrations were approximately 1000 ppm around the roots of white clover, but significantly decreased with increasing distance from roots. In behavioural experiments, no evidence was found for any attraction by S. lepidus larvae to point emissions of CO2, regardless of emission rates. Fewer than 15% of larvae were attracted to point emissions of CO2, compared with a control response of 17%. However, fractal analysis of movement paths in constant CO2 concentrations demonstrated that searching by S. lepidus larvae significantly intensified when they experienced CO2 concentrations similar to those found around the roots of white clover (i.e. 1000 ppm). It is suggested that respiratory emissions of CO2 may act as a 'search trigger' for S. lepidus, whereby it induces larvae to search a smaller area more intensively, in order to detect location cues that are more specific to their host plant.

Searching efficiency and the functional response of a pause-travel forager

1. The feeding rates of many predators and parasitoids exhibit type II functional responses, with a decelerating rate of increase to reach an asymptotic value as the density of their prey or hosts increases. Holling's disc equation describes such relationships and predicts that the asymptotic feeding rate at high prey densities is set by handling time, while the rate at which feeding rate increases with increased prey density is determined by searching efficiency. Searching efficiency and handling time are also parameters in other models which describe the functional response. Models which incorporate functional responses in order to make predictions of the effects of food shortage thus rely upon a clear understanding and accurate quantification of searching efficiency and handling time. 2. Blackbird Turdus merula exhibit a type II functional response and use pause-travel foraging, a foraging technique in which animals search for prey while stationary and then move to capture prey. Pause-travel foraging allows accurate direct measurement of feeding rate and both searching efficiency and handling time. We use Blackbirds as a model species to: (i) compare observed measures of both searching efficiency and handling time with those estimated by statistically fitting the disc equation to the observed functional response; and (ii) investigate alternative measures of searching efficiency derived by the established method where search area is assumed to be circular and a new method that we propose where it is not. 3. We find that the disc equation can adequately explain the functional response of blackbirds feeding on artificial prey. However, this depends critically upon how searching efficiency is measured. Two variations on the previous method of measuring search area (a component of searching efficiency) overestimated searching efficiency, and hence predicted feeding rates higher than those observed. Two variations of our alternative approach produced lower estimates of searching efficiency, closer to that estimated by fitting the disc equation, and hence more accurately predicted feeding rate. Our study shows the limitations of the previous method of measuring searching efficiency, and describes a new method for measuring searching efficiency more accurately.