Key Stage Three Shakespeare : Twelfth night. 'Etapa Clave Tres Shakespeare : Noche de Reyes'

Este texto guiado ayuda a los alumnos de once a catorce años de la etapa 3 de secundaria (Key Stage 3) del curriculo nacional inglés en la comprensión del contexto histórico, de los temas tratados y de los personajes que aparecen en el texto. Esta dividida en secciones y al final de cada una de ellas hay un repaso resumido y preguntas para asentar los conocimientos.

Key Stage Three Shakespeare : Macbeth. 'Etapa Clave Tres Shakespeare : Macbeth'.

Este texto guiado ayuda a los alumnos de once a catorce años de la etapa 3 de secundaria (Key Stage 3) del curriculo nacional inglés en la comprensión del contexto histórico, de los temas tratados y de los personajes que aparecen en el texto. Esta dividida en secciones y al final de cada una de ellas hay un repaso resumido y preguntas para asentar los conocimientos.

Key Stage Three Shakespeare : The Tempest : the text guide. ''Etapa Clave Tres Shakespeare : La tempestad : texto guía'

Este texto guiado ayuda a los alumnos de once a catorce años de la etapa 3 de secundaria (Key Stage 3) del curriculo nacional inglés en la comprensión del contexto histórico, de los temas tratados y de los personajes que aparecen en el texto. Esta dividida en secciones y al final de cada una de ellas hay un repaso resumido y preguntas para asentar los conocimientos.

Key Stage Three Shakespeare : Romeo and Juliet : the text guide. 'Etapa Clave Tres Shakespeare : Romeo y Julieta : texto guía'.

Este texto guiado ayuda a los alumnos de once a catorce años de la etapa 3 de secundaria (Key Stage 3) del curriculo nacional inglés en la comprensión del contexto histórico, de los temas tratados y de los personajes que aparecen en el texto. Esta dividida en secciones y al final de cada una de ellas hay un repaso resumido y preguntas para asentar los conocimientos.

Key Stage Three Shakespeare : Much ado about nothing. 'Etapa Clave Tres Shakespeare : Mucho ruido y pocas nueces'.

Este texto guiado ayuda a los alumnos de once a catorce años de la etapa 3 de secundaria (Key Stage 3) del curriculo nacional inglés en la comprensión del contexto histórico, de los temas tratados y de los personajes que aparecen en el texto. Esta dividida en secciones y al final de cada una de ellas hay un repaso resumido y preguntas para asentar los conocimientos.

Key Stage Three History. The study guide.

Este texto guiado esta dividido en cuatro secciones y comprende la historia del mundo desde la Edad Media hasta la actualidad. Al final de cada una de las secciones hay un repaso resumido y se formulan preguntas para ayudar a los alumnos de secundaria de la etapa 3 (Key stage 3) del curriculo nacional inglés a preparar en casa el nuevo Programa de Estudio (Programme of Study).

Key Stage Three History. The workbook.

Es un recurso para ser utilizado por los estudiantes en su casa con preguntas y ejercicios prácticos basado en la guía de estudio de la asignatura de historia. Ayuda a los alumnos de secundaria de la etapa 3 (Key stage 3) del curriculo nacional inglés a preparar los exámenes del nuevo Programa de Estudio (Programme of Study). Se completa con otro recurso, un libro de respuestas.

Key stage three History : Answer book. 'Etapa clave tres Historia : libro de respuestas'.

Este recurso es el complemento al cuaderno de trabajo de la asignatura de historia utilizado por los estudiantes y contiene las respuestas a las preguntas formuladas en éste. Ayuda a los alumnos de secundaria de la etapa 3 (Key stage 3) del curriculo nacional inglés a preparar los exámenes del nuevo Programa de Estudio (Programme of Study).

Key stage three History : complete revision and practice. 'Etapa clave tres Historia : revisión completa y práctica'.

Este texto guiado esta dividido en cuatro secciones y comprende la historia del mundo desde la Edad Media hasta la actualidad. Al final de cada una de las secciones un repaso resumido, la utilización de fuentes históricas y preguntas prácticas ayudan a los alumnos de once a catorce años a preparar los exámenes de secundaria de la etapa 3 (Key stage 3) del curriculo nacional inglés.

Key Stage 3 mathematics : practice tests, : levels 5-8.

Los materiales de esta carpeta se caracterizan por:preparar a los alumnos con el nivel adecuado para su paso a la etapa clave tres (Key Stage 3); promover en los alumnos la autonomía en el trabajo escolar y consolidar el aprendizaje de los conocimientos fundamentales que debe tener el alumno para acceder a esta etapa. Contiene tres conjuntos diferentes de pruebas, además de un folleto con las respuestas y consejos prácticos para dar a los estudiantes la oportunidad de identificar las áreas en las que tienen los conocimientos más bajos y poder revisar éstos.

Key stage 3 mathematics : numeracy strategy book 3.

Este manual ha sido escrito para cubrir la estrategia de cálculo para la etapa clave tres de matemáticas (Key Stage 3) en los niveles seis, ocho. Cada página contiene preguntas relativas a un tema de estrategia de la aritmética. También se han incluido recomendaciones para algunas de las preguntas más difíciles. No es específico del año, por lo que se puede utilizar en distintas clases. Viene con todas las respuestas al final de la publicación.

The relationship between diffuse spectral reflectance of the soil and its cation exchange capacity is scale-dependent

Diffuse reflectance spectroscopy (DRS) is increasingly being used to predict numerous soil physical, chemical and biochemical properties. However, soil properties and processes vary at different scales and, as a result, relationships between soil properties often depend on scale. In this paper we report on how the relationship between one such property, cation exchange capacity (CEC), and the DRS of the soil depends on spatial scale. We show this by means of a nested analysis of covariance of soils sampled on a balanced nested design in a 16 km × 16 km area in eastern England. We used principal components analysis on the DRS to obtain a reduced number of variables while retaining key variation. The first principal component accounted for 99.8% of the total variance, the second for 0.14%. Nested analysis of the variation in the CEC and the two principal components showed that the substantial variance components are at the > 2000-m scale. This is probably the result of differences in soil composition due to parent material. We then developed a model to predict CEC from the DRS and used partial least squares (PLS) regression do to so. Leave-one-out cross-validation results suggested a reasonable predictive capability (R2 = 0.71 and RMSE = 0.048 molc kg− 1). However, the results from the independent validation were not as good, with R2 = 0.27, RMSE = 0.056 molc kg− 1 and an overall correlation of 0.52. This would indicate that DRS may not be useful for predictions of CEC. When we applied the analysis of covariance between predicted and observed we found significant scale-dependent correlations at scales of 50 and 500 m (0.82 and 0.73 respectively). DRS measurements can therefore be useful to predict CEC if predictions are required, for example, at the field scale (50 m). This study illustrates that the relationship between DRS and soil properties is scale-dependent and that this scale dependency has important consequences for prediction of soil properties from DRS data

Iron Uptake and Homeostasis in Microorganisms

Preface. Iron is considered to be a minor element employed, in a variety of forms, by nearly all living organisms. In some cases, it is utilised in large quantities, for instance for the formation of magnetosomes within magnetotactic bacteria or during use of iron as a respiratory donor or acceptor by iron oxidising or reducing bacteria. However, in most cases the role of iron is restricted to its use as a cofactor or prosthetic group assisting the biological activity of many different types of protein. The key metabolic processes that are dependent on iron as a cofactor are numerous; they include respiration, light harvesting, nitrogen fixation, the Krebs cycle, redox stress resistance, amino acid synthesis and oxygen transport. Indeed, it is clear that Life in its current form would be impossible in the absence of iron. One of the main reasons for the reliance of Life upon this metal is the ability of iron to exist in multiple redox states, in particular the relatively stable ferrous (Fe2+) and ferric (Fe3+) forms. The availability of these stable oxidation states allows iron to engage in redox reactions over a wide range of midpoint potentials, depending on the coordination environment, making it an extremely adaptable mediator of electron exchange processes. Iron is also one of the most common elements within the Earth’s crust (5% abundance) and thus is considered to have been readily available when Life evolved on our early, anaerobic planet. However, as oxygen accumulated (the ‘Great oxidation event’) within the atmosphere some 2.4 billion years ago, and as the oceans became less acidic, the iron within primordial oceans was converted from its soluble reduced form to its weakly-soluble oxidised ferric form, which precipitated (~1.8 billion years ago) to form the ‘banded iron formations’ (BIFs) observed today in Precambrian sedimentary rocks around the world. These BIFs provide a geological record marking a transition point away from the ancient anaerobic world towards modern aerobic Earth. They also indicate a period over which the bio-availability of iron shifted from abundance to limitation, a condition that extends to the modern day. Thus, it is considered likely that the vast majority of extant organisms face the common problem of securing sufficient iron from their environment – a problem that Life on Earth has had to cope with for some 2 billion years. This struggle for iron is exemplified by the competition for this metal amongst co-habiting microorganisms who resort to stealing (pirating) each others iron supplies! The reliance of micro-organisms upon iron can be disadvantageous to them, and to our innate immune system it represents a chink in the microbial armour, offering an opportunity that can be exploited to ward off pathogenic invaders. In order to infect body tissues and cause disease, pathogens must secure all their iron from the host. To fight such infections, the host specifically withdraws available iron through the action of various iron depleting processes (e.g. the release of lactoferrin and lipocalin-2) – this represents an important strategy in our defence against disease. However, pathogens are frequently able to deploy iron acquisition systems that target host iron sources such as transferrin, lactoferrin and hemoproteins, and thus counteract the iron-withdrawal approaches of the host. Inactivation of such host-targeting iron-uptake systems often attenuates the pathogenicity of the invading microbe, illustrating the importance of ‘the battle for iron’ in the infection process. The role of iron sequestration systems in facilitating microbial infections has been a major driving force in research aimed at unravelling the complexities of microbial iron transport processes. But also, the intricacy of such systems offers a challenge that stimulates the curiosity. One such challenge is to understand how balanced levels of free iron within the cytosol are achieved in a way that avoids toxicity whilst providing sufficient levels for metabolic purposes – this is a requirement that all organisms have to meet. Although the systems involved in achieving this balance can be highly variable amongst different microorganisms, the overall strategy is common. On a coarse level, the homeostatic control of cellular iron is maintained through strict control of the uptake, storage and utilisation of available iron, and is co-ordinated by integrated iron-regulatory networks. However, much yet remains to be discovered concerning the fine details of these different iron regulatory processes. As already indicated, perhaps the most difficult task in maintaining iron homeostasis is simply the procurement of sufficient iron from external sources. The importance of this problem is demonstrated by the plethora of distinct iron transporters often found within a single bacterium, each targeting different forms (complex or redox state) of iron or a different environmental condition. Thus, microbes devote considerable cellular resource to securing iron from their surroundings, reflecting how successful acquisition of iron can be crucial in the competition for survival. The aim of this book is provide the reader with an overview of iron transport processes within a range of microorganisms and to provide an indication of how microbial iron levels are controlled. This aim is promoted through the inclusion of expert reviews on several well studied examples that illustrate the current state of play concerning our comprehension of how iron is translocated into the bacterial (or fungal) cell and how iron homeostasis is controlled within microbes. The first two chapters (1-2) consider the general properties of microbial iron-chelating compounds (known as ‘siderophores’), and the mechanisms used by bacteria to acquire haem and utilise it as an iron source. The following twelve chapters (3-14) focus on specific types of microorganism that are of key interest, covering both an array of pathogens for humans, animals and plants (e.g. species of Bordetella, Shigella, , Erwinia, Vibrio, Aeromonas, Francisella, Campylobacter and Staphylococci, and EHEC) as well as a number of prominent non-pathogens (e.g. the rhizobia, E. coli K-12, Bacteroides spp., cyanobacteria, Bacillus spp. and yeasts). The chapters relay the common themes in microbial iron uptake approaches (e.g. the use of siderophores, TonB-dependent transporters, and ABC transport systems), but also highlight many distinctions (such as use of different types iron regulator and the impact of the presence/absence of a cell wall) in the strategies employed. We hope that those both within and outside the field will find this book useful, stimulating and interesting. We intend that it will provide a source for reference that will assist relevant researchers and provide an entry point for those initiating their studies within this subject. Finally, it is important that we acknowledge and thank wholeheartedly the many contributors who have provided the 14 excellent chapters from which this book is composed. Without their considerable efforts, this book, and the understanding that it relays, would not have been possible. Simon C Andrews and Pierre Cornelis

The influence of age and gender on food choice: a focus group exploration

With 25% of the UK population predicted to be obese by 2010, the costs to individuals and society are set to rise. Due to the extra economic and social pressures obesity causes, there is an increasing need to understand what motivates and prevents consumers from eating a healthy diet so as to be able to tailor policy interventions to specific groups in society. In so doing, it is important to explore potential variations in attitudes, motivation and behaviour as a function of age and gender. Both demographic factors are easily distinguished within society and a future intervention study which targets either, or both, of these would likely be both feasible and cost-effective for policy makers. As part of a preliminary study, six focus groups (total n = 43) were conducted at the University of Reading in November 2006, with groups segmented on the basis of age and gender. In order to gather more sensitive information, participants were also asked to fill out a short anonymous questionnaire before each focus group began, relating to healthy eating, alcohol consumption and body dissatisfaction. Making use of thematic content analysis, results suggested that most participants were aware of the type of foods that contribute to a healthy diet and the importance of achieving a healthy balance within a diet. However, they believed that healthy eating messages were often conflicting, and were uncertain about where to find information on the topic. Participants believed that the family has an important role in educating children about eating habits. Despite these similarities, there were a number of key differences among the groups in terms of their reasons for making food choices. Older participants (60+ years old) were more likely to make food choices based on health considerations. Participants between the ages of 18–30 were less concerned with this link, and instead focused on issues of food preparation and knowledge, prices and time. Younger female participants said they had more energy when they ate healthier diets; however, very often their food choices related to concern with their appearance. Older female participants also expressed this concern within the questionnaire, rather than in the group discussions. Overall, these results suggest that consumer motivations for healthy eating are diverse and that this must be considered by government, retailers and food producers.

Reproducibility of a short semi-quantitative food group questionnaire and its performance in estimating nutrient intake compared with a 7-day diet diary in the Million Women Study

Objectives: To assess the short- and long-term reproducibility of a short food group questionnaire, and to compare its performance for estimating nutrient intakes in comparison with a 7-day diet diary. Design: Participants for the reproducibility study completed the food group questionnaire at two time points, up to 2 years apart. Participants for the performance study completed both the food group questionnaire and a 7-day diet diary a few months apart. Reproducibility was assessed by kappa statistics and percentage change between the two questionnaires; performance was assessed by kappa statistics, rank correlations and percentages of participants classified into the same and opposite thirds of intake. Setting: A random sample of participants in the Million Women Study, a population-based prospective study in the UK. Subjects: In total, 12 221 women aged 50-64 years. Results: in the reproducibility study, 75% of the food group items showed at least moderate agreement for all four time-point comparisons. Items showing fair agreement or worse tended to be those where few respondents reported eating them more than once a week, those consumed in small amounts and those relating to types of fat consumed. Compared with the diet diary, the food group questionnaire showed consistently reasonable performance for the nutrients carbohydrate, saturated fat, cholesterol, total sugars, alcohol, fibre, calcium, riboflavin, folate and vitamin C. Conclusions: The short food group questionnaire used in this study has been shown to be reproducible over time and to perform reasonably well for the assessment of a number of dietary nutrients.