Interactive effects of cadmium and zinc pollution on PGI and PGM polymorphisms in Idotea baltica

Separate and interactive pollution effects of Cd and Zn on electrophoretically-detected allozyme frequencies of the different genotypes at PGI and PGM loci were studied in Idotea baltica.

Differential survivorship of PGM genotypes was detected in the presence of the single or combined pollutants, while no effect was observed for PGI. Cadmium decreased heterozygosity while zinc or Cd + Zn increased it, suggesting an antithetic action of the two metals and the prevalence of zinc.     

Enhanced boulder weathering under late-lying snowpatches

A Schmidt test hammer was employed to assess the aggregate surface hardness of samples of boulders dug out from under late-lying snowpatches at sites in Switzerland, Scotland and Norway. The results were compared with an equivalent set of readings made on boulders at nearby snow-free control sites. The results in every case reveal that the aggregate surface hardness of boulders buried by late-lying snow is significantly less (at the 0·001 level) than that of boulders at the corresponding control sites. This result indicates that late-lying snow significantly enhances rock weathering, probably because boulder and rock surfaces are exposed to prolonged wetting by percolating meltwater under late-lying snowbeds.     

The mobility, partitioning and degradation of atrazine and simazine in the salt marsh environment

The transfer of the s-triazine herbicides onto a salt marsh and their subsequent behaviour and fate has been investigated in a series of laboratory-based experiments. The results indicate that atrazine and simazine enter the marsh system and undergo negligible adsorption onto suspended solids. Herbicide accumulation within the sediment compartment was thought to be due to other mechanisms such as partitioning into the surface microlayer, or association with sediment flocs. s-Triazine mobility within the sediment was dictated by compound and sediment type, reflecting greater mobility in the mud flat than the vegetated marsh sediment. The majority of the herbicides were, however, retained in the uppermost layers of the sediment profile indicating that salt marsh sediments act as a sink for these compounds. Although degradation rates in the sediment were relatively rapid, detectable levels of the parent compounds were still evident after 71 days, which implies that these compounds may persist in salt marsh sediments. The absence of degradation in the aqueous phase implies that adsorption to particulate matter is a prerequisite for the degradation of the s-triazine herbicides.     

Pragmatic localism uncovered: The search for locally contingent solutions to national reform agendas

This paper analyses the complexity and attempted pragmatism of current practices surrounding the management of current local government policy reform in England. In particular, it focuses on the tensions and contradictions between a national policy dynamic which seeks to encourage locally contingent solutions to be developed for localised problems, and the centralising tendencies of the national state which result in ‘blueprints’ and ‘models’ being developed for local policy delivery and a requirement to meet centrally derived targets. These assumptions are explored through the experiences of local government attempts to introduce innovative and experimental praxis in line with the complex cultural and political changes of ‘modernisation’ agendas advanced by the UK government. This is being rolled out by an overarching project of ‘new localism’ - an attempt to devolve power and resources from the central state to front line local managers, sub-local structures and partnerships and to deliver ‘what works’. It is argued that new attempts at subsidiarity should be more flexible to local conditions rather than directed by national policy and that greater discretion and freedom should be given to local managers to achieve this task. Using the concept of ‘pragmatic localism’ and grounded examples from a recent initiative - Local Area Agreements - it is highlighted that there are signs that local state management of national policy could be becoming increasingly adaptable, enabling managers to deal with the fluid nature of ongoing public policy reform, although this is far from a completed project with many factors still constraining this change process.     

Morphological response to river engineering and management in alluvial channels in Italy

In response to various types of human disturbance, most Italian rivers have experienced considerable channel adjustment during the last centuries and in particular in the last decades. This paper reviews all existing published studies and available data, and aims to reconstruct a general outline of the main channel adjustments that have occurred in Italian rivers during the past 100 years.Two main types of channel adjustment have been recognized: (a) incision, which is commonly on the order of 3–4 m, but in some cases is even more than 10 m; (b) narrowing, with channel width reduction up to 50% or more. In some reaches, these adjustments have led to changes in channel pattern in particular from braided to wandering.Such channel adjustments are due to several types of human intervention, particularly sediment extraction, dams and channelization. A strong temporal relationship (specifically, short reaction times) between human disturbance and channel adjustment can be inferred, but trends of adjustment are available for only a few rivers (e.g. the Po, the Arno and the Piave Rivers). These trends show that incision and/or narrowing are more intense immediately after the disturbance and then slow and become asymptotic; the same trends also suggest that larger rivers could have longer relaxation times.The results of this study are synthesised in a general classification scheme that summarises the main styles of adjustment observed in Italian rivers. According to the scheme, braided rivers adjust through prevalent narrowing with varying rates of incision, whereas single-thread rivers adjust mainly through a more pronounced incision accompanied by various amounts of narrowing. The scheme, representing initial and final (present) morphologies and not including intermediate stages of channel adjustment, will need to be tested on the basis of more detailed data to have a wider application both to the Italian context and to fluvial systems elsewhere, affected by similar types of human disturbance causing a reduction of sediment supply.