Metal bioaccumulation and cellular fractionation in an epigeic earthworm (Lumbricus rubellus): the interactive influences of population exposure histories, site-specific geochemistry and mitochondrial genotype

Subcellular fractionation techniques were used to describe temporal changes (at intervals from T0 to T70 days) in the Pb, Zn and P partitioning profiles of Lumbricus rubellus populations from one calcareous (MDH) and one acidic (MCS) geographically isolated Pb/Zn-mine sites and one reference site (CPF). MDH and MCS individuals were laboratory maintained on their native field soils; CPF worms were exposed to both MDH and MCS soils. Site-specific differences in metal partitioning were found: notably, the putatively metal-adapted populations, MDH and MCS, preferentially partitioned higher proportions of their accumulated tissue metal burdens into insoluble CaPO4-rich organelles compared with naive counterparts, CPF. Thus, it is plausible that efficient metal immobilization is a phenotypic trait characterising metal tolerant ecotypes. Mitochondrial cytochrome oxidase II (COII) genotyping revealed that the populations indigenous to mine and reference soils belong to distinct genetic lineages, differentiated by 13%, with 7 haplotypes within the reference site lineage but fewer (3 and 4, respectively) in the lineage common to the two mine sites. Collectively, these observations raise the possibility that site-related genotype differences could influence the toxico-availability of metals and, thus, represent a potential confounding variable in field-based eco-toxicological assessments.

The effects of irrigation, nitrogen fertilizer and grain size on Hagberg falling number, specific weight and blackpoint of winter wheat

The effects of irrigation and nitrogen (N) fertilizer on Hagberg falling number (HFN), specific weight (SW) and blackpoint (BP) of winter wheat (Triticum aestivum L) were investigated. Mains water (+50 and +100 mm month(-1), containing 44 mg NO3- litre(-1) and 28 mg SO42- litre(-1)) was applied with trickle irrigation during winter (17 January-17 March), spring (21 March-20 May) or summer (24 May-23 July). In 1999/2000 these treatments were factorially combined with three N levels (0, 200, 400 kg N ha(-1)), applied to cv Hereward. In 2000/01 the 400 kg N ha(-1) treatment was replaced with cv Malacca given 200 kg N ha(-1). Irrigation increased grain yield, mostly by increasing grain numbers when applied in winter and spring, and by increasing mean grain weight when applied in summer. Nitrogen increased grain numbers and SW, and reduced BP in both years. Nitrogen increased HFN in 1999/2000 and reduced HFN in 2000/01. Effects of irrigation on HFN, SW and BP were smaller and inconsistent over year and nitrogen level. Irrigation interacted with N on mean grain weight: negatively for winter and spring irrigation, and positively for summer irrigation. Ten variables derived from digital image analysis of harvested grain were included with mean grain weight in a principal components analysis. The first principal component ('size') was negatively related to HFN (in two years) and BP (one year), and positively related to SW (two years). Treatment effects on dimensions of harvested grain could not explain all of the effects on HFN, BP and SW but the results were consistent with the hypothesis that water and nutrient availability, even when they were affected early in the season, could influence final grain quality if they influenced grain numbers and size. (C) 2004 Society of Chemical Industry

Creating teaching and learning in Europe: promoting a new paradigm

The tides of globalization and the unsteady surges and distortions in the evolution of the European Union are causing identities and cultures to be in a state of flux. Education is used by politicians as a major lever for political and social change through micro-management, but it is a crude tool. There can, however, be opportunities within educational experience for individual learners to gain strong, reflexive, multiple identities and multiple citizenship through the engagement of their creative energies. It has been argued that the twenty-first century needs a new kind of creativity characterized by unselfishness, caring and compassion—still involving monetary wealth, but resulting in a healthy planet and healthy people. Creativity and its economically derived relation, innovation, have become `buzz words' of our times. They are often misconstrued, misunderstood and plainly misused within educational conversations. The small-scale pan-European research study upon which this article is founded discovered that more emphasis needs to be placed on creative leadership, empowering teachers and learners, reducing pupils' fear of school, balancing teaching approaches, and ensuring that the curriculum and assessment are responsive to the needs of individual learners. These factors are key to building strong educational provision that harnesses the creative potential of learners, teachers and other stakeholders, values what it is to be human and creates a foundation upon which to build strong, morally based, consistent, participative democracies.

Establishing a sexual identity: case studies of learners with autism and learning difficulties

The physical and emotional changes that occur in adolescence are part of the process of sexual maturity. These changes occur irrespective of ability and are often aligned with psychological and social factors. When the nature of a disability has an inherent limitation in social awareness, as is the case for individuals with autism, the achievement of personal sexual identity can become much more complex. Challenges in supporting individuals in this respect can be caused by the sensitive aspects of inappropriate behaviour, the abstract nature of teaching the topic, and the general reluctance on the part of parents and staff to discuss sexuality in individuals with disabilities. This article explores how a residential school addressed this gap. It provides details of how this need was met for seven students and the process undertaken to involve staff, parents and other stakeholders to establish ongoing support.

Apparent specific volumes and tastes of cyclamates, other sulfamates, saccharins and acesulfame sweeteners

Measurements of apparent specific volume (ASV) for a series of alternative sweeteners (cyclamates, sulfamates, saccharins, acesulfames and anilinomethanesulfonates) have been made. Taste data have been obtained for many of the new compounds unless the toxicity of the associated metals precluded this. Apparent molar volume (AMV), isentropic specific (IASC) and isentropic molar (IAMC) compressibilities were also measured. Sixteen metallic cyclamates cyc-C6H11NHSO3M and two phenylsulfamates ArNHSO3Na, namely 3.5-dimethyl- and 3,4-dimethoxyphenylsulfamates have been examined. When the ASVs for these are combined with those for 15 aliphatic, aromatic and alicyclic sulfamates from a previous study, many of the values are seen to fall into the region that was previously identified as being the "sweet area", i.e. the ASVs lay between similar to0.5 and similar to0.7 (a few sweet compounds fall below this range and it is suggested that it could be extended slightly to accommodate these). Interestingly, the anilinomethanesulfonates, ArNHCH2SO3Na (Ar = C6H5-, 3-MeC6H4- and 3-ClC6H4-) lie clearly in the sweet region but only one of them shows slight sweetness showing that the molecular structural change made (compared with the 'parent' sulfamate-NHSO3-) cannot be accommodated at the receptor site. (C) 2003 Elsevier Ltd. All rights reserved.