Amazing science experiments : 150 easy projects using everyday materials, demostrated step by step in 1300 photographs.

Colección de ciento cincuenta experimentos que explican hechos y procesos científicos, y demuestran cómo funcionan las máquinas. Cada experimento se introduce, describe y explica, y esta información no sólo permite al usuario trabajar con confianza, sino que también proporciona una gran cantidad de conocimiento científico adicional para los niños de ocho a doce años. Dividido en cuatro secciones, cada una explora con un tema cotidiano diversas áreas especializadas de la ciencia: nuestra tierra inquieta, maravillas naturales cerca de casa, maravillas físicas y materiales, viajes y transporte.

New maths frameworking: Step-Up Workbook 1.

Este libro asegura una transición sin problemas desde el nivel de enseñanza primaria Key Stage 2 a Key Stage 3 (enseñanza secundaria), las ilustraciones basadas en las preguntas hacen que los conceptos básicos sean fáciles de entender y recordar. Los temas del libro son: entendiendo los números (ordenando los números, contando), la suma, la resta, fracciones (mitades y cuartos), medidas de longitud y tiempo (midiendo en metros, midiendo en centímetros, la era digital), entendiendo las formas (lados y esquinas), multiplicación y división, medidas de peso, capacidad y tiempo.

New maths frameworking: Step-Up Workbook 3.

Este libro asegura una transición sin problemas desde el nivel de enseñanza primaria Key Stage 2 a Key Stage 3 (enseñanza secundaria), las ilustraciones basadas en las preguntas hacen que los conceptos básicos sean fáciles de entender y recordar. Los temas del libro son: números y álgebra (ordenando números, números negativos), fracciones y decimales (fracción de un número, décimas como decimales), suma y resta, multiplicación y división, dinero (libras y peniques), medidas de longitud y tiempo (midiendo en milímetros, usando unidades métricas de longitud, perímetro, área), ¿formas regulares o irregulares?, medidas de peso, capacidad y tiempo (gramos y kilogramos, fracciones de un litro).

Spontaneous Meta-Arithmetic as the First Step Toward School Algebra. 'La meta-aritmética espontánea como el primer paso hacia el álgebra escolar'.

Resumen basado en el de la publicación

An incomplete step toward a banking union. CEPS Commentary, 5 July 2012

In this Commentary, Daniel Gros applauds the decision taken by Europe’s leaders at the eurozone summit at the end of June to transfer responsibility for banking supervision in the eurozone to the European Central Bank. It represents explicit recognition of the important fact that problems might originate at the national level, but, owing to monetary union, they can quickly threaten the stability of the entire eurozone banking system. In his view, the next small, incremental step, although one not yet officially acknowledged, will necessarily be the creation of a common bank rescue fund.

Backloading: A necessary, but not sufficient first step. CEPS Special Report No. 72, 20 November 2012

In July 2012, the European Commission issued an invitation for public consultation to review the ‘auctioning time profile’ for the EU Emissions Trading Scheme” in order to collect views from stakeholders and experts in the field of the EU carbon market on a draft for a future amendment of the Commission Regulation on the timing, administration and other aspects of auctioning of greenhouse gas emission allowances. In this submission, the CEPS Carbon Market Forum addresses the following questions and offers its views on the Commission’s proposed amendments: Is back loading a good idea? Is there a need for following up the back loading with structural measures? What should the number be? If this cannot be addressed, what are the considerations for deciding upon that number? What price expectations are linked to the number? On what basis are they construed?

Sequential extraction and single-step cold-acid extraction: A feasibility study for use with freshwater-canal sediments

This investigation examines metal release from freshwater sediment using sequential extraction and single-step cold-acid leaching. The concentrations of Cd, Cr, Cu, Fe, Ni, Pb and Zn released using a standard 3-step sequential extraction (Rauret et al., 1999) are compared to those released using a 0.5 M HCl; leach. The results show that the three sediments behave in very different ways when subject to the same leaching experiments: the cold-acid extraction appears to remove higher relative concentrations of metals from the iron-rich sediment than from the other two sediments. Cold-acid extraction appears to be more effective at removing metals from sediments with crystalline iron oxides than the "reducible" step of the sequential extraction. The results show that a single-step acid leach can be just as effective as sequential extractions at removing metals from sediment and are a great deal less time-consuming.

An extension of an over-dispersion test for count data

While over-dispersion in capture–recapture studies is well known to lead to poor estimation of population size, current diagnostic tools to detect the presence of heterogeneity have not been specifically developed for capture–recapture studies. To address this, a simple and efficient method of testing for over-dispersion in zero-truncated count data is developed and evaluated. The proposed method generalizes an over-dispersion test previously suggested for un-truncated count data and may also be used for testing residual over-dispersion in zero-inflation data. Simulations suggest that the asymptotic distribution of the test statistic is standard normal and that this approximation is also reasonable for small sample sizes. The method is also shown to be more efficient than an existing test for over-dispersion adapted for the capture–recapture setting. Studies with zero-truncated and zero-inflated count data are used to illustrate the test procedures.

Estimating the hidden number of scrapie affected holdings in great Britain using a simple, truncated count model allowing for heterogeneity.

None of the current surveillance streams monitoring the presence of scrapie in Great Britain provide a comprehensive and unbiased estimate of the prevalence of the disease at the holding level. Previous work to estimate the under-ascertainment adjusted prevalence of scrapie in Great Britain applied multiple-list capture–recapture methods. The enforcement of new control measures on scrapie-affected holdings in 2004 has stopped the overlapping between surveillance sources and, hence, the application of multiple-list capture–recapture models. Alternative methods, still under the capture–recapture methodology, relying on repeated entries in one single list have been suggested in these situations. In this article, we apply one-list capture–recapture approaches to data held on the Scrapie Notifications Database to estimate the undetected population of scrapie-affected holdings with clinical disease in Great Britain for the years 2002, 2003, and 2004. For doing so, we develop a new diagnostic tool for indication of heterogeneity as well as a new understanding of the Zelterman and Chao’s lower bound estimators to account for potential unobserved heterogeneity. We demonstrate that the Zelterman estimator can be viewed as a maximum likelihood estimator for a special, locally truncated Poisson likelihood equivalent to a binomial likelihood. This understanding allows the extension of the Zelterman approach by means of logistic regression to include observed heterogeneity in the form of covariates—in case studied here, the holding size and country of origin. Our results confirm the presence of substantial unobserved heterogeneity supporting the application of our two estimators. The total scrapie-affected holding population in Great Britain is around 300 holdings per year. None of the covariates appear to inform the model significantly.

Can we harness computerised cognitive bias modification to treat anxiety in schizophrenia? A first step highlighting the role of mental imagery

A new wave of computerised therapy is under development which, rather than simulating talking therapies, uses bias modification techniques to target the core psychological process underlying anxiety. Such interventions are aimed at anxiety disorders, and are yet to be adapted for co-morbid anxiety in psychosis. The cognitive bias modification (CBM) paradigm delivers repeated exposure to stimuli in order to train individuals to resolve ambiguous information in a positive, rather than anxiety provoking, manner. The current study is the first to report data from a modified form of CBM which targets co-morbid anxiety within individuals diagnosed with schizophrenia. Our version of CBM involved exposure to one hundred vignettes presented over headphones. Participants were instructed to actively simulate the described scenarios via visual imagery. Twenty-one participants completed both a single session of CBM and a single control condition session in counter-balanced order. Within the whole sample, there was no significant improvement on interpretation bias of CBM or state anxiety, relative to the control condition. However, in line with previous research, those participants who engage in higher levels of visual imagery exhibited larger changes in interpretation bias. We discuss the implications for harnessing computerised CBM therapy developments for co-morbid anxiety in schizophrenia.

Simple and surprisingly effective one-step extraction-cleanup by Soxflo for DDT and its metabolites from environmental samples

A pilot study found that DDT breakdown at the GC inlet was extensive in extracts from some-but not all-samples with high organic carbon contents. However, DDT losses could be prevented with a one-step extraction-cleanup in the Soxflo instrument with dichloromethane and charcoal. This dry-column procedure took 1 h at room temperature. It was tested on spiked soil and peat samples and validated with certified soil and sediment reference materials. Spike recoveries from freshly spiked samples ranged from 79 to 111% at 20-4000 mug/kg concentrations. Recoveries from the real-world CRMs were 99.7-100.2% of DDT, 89.7-90.4% of DDD and 89.6-107.9% of DDE. It was concluded that charcoal cleanups should be used routinely during surveys for environmental DDX pollution in order to mitigate against unpredictable matrix-enhanced breakdown in the GC. (C) 2004 Elsevier B.V. All rights reserved.