Random walk of magnetic field lines for different values of the energy range spectral index

An analytical nonlinear description of field-line wandering in partially statistically magnetic systems was proposed recently. In this article the influence of the wave spectrum in the energy range onto field-line random walk is investigated by applying this formulation. It is demonstrated that in all considered cases we clearly obtain a superdiffusive behavior of the field-lines. If the energy range spectral index exceeds unity a free-streaming behavior of the field-lines can be found for all relevant length-scales of turbulence. Since the superdiffusive results obtained for the slab model are exact, it seems that superdiffusion is the normal behavior of field-line wandering.

A simple colorimetric method for the quality control of 1-alkyl-3-methylimidazolium ionic liquid precursors

A simple colorimetric method to monitor the production of ionic liquid precursors is developed, which is based on the determination of 1-methylimidazole with copper(II) chloride. The synthesis of 1-ethyl-3-methylimidazolium chloride, an industrially important ionic liquid precursor, can be followed and the purity of the final product can be readily assessed in a quick and convenient manner.

Statin prescribing in Northern Ireland and England pre and post introduction of the quality and outcomes framework

Objective The objective of this research was to examine differences in patterns of statin prescribing between Northern Ireland and England both before and after the introduction of the Quality and Outcomes Framework (QOF). Setting: Primary care practices in Northern Ireland and England. Method Northern Ireland practices were matched with practices in England, statin prescribing data and QOF achievement scores (for the first year post-QOF) were obtained. Crude prescribing data from matched practices were manipulated to provide a data set of Defined Daily Doses (DDDs)/1,000 patients and cost/DDD/1,000 patients for each statin drug entity covering 1 year before and after the introduction of QOF. QOF achievements were converted into percentage scores for matched practices. Main outcome measure Cost per defined daily dose (DDD) per 1,000 patients. Results Significantly less statins (DDD/1,000 patients) were dispensed in Northern Ireland compared with the matched region in England both before and after the introduction of QOF (P

Temporal changes in the distribution of native and introduced freshwater amphipods in Lough Neagh, Northern Ireland

Studies of invasion scenarios over long time periods are important to refine explanations and predictions of invasion success and impact. We used data from surveys in 1958 and 1999 of the macroinvertebrates of Lough Neagh, Northern Ireland, to assess changes in the distribution of native and introduced amphipods in relation to the wider assemblage. In 1958, the invader G. tigrinus dominated the shoreline fauna, with the native G. d. celticus present in very low numbers, whereas in 1999 the reverse was evident. In both surveys, G. tigrinus was the only amphipod present in the mid-Lough. G. tigrinus thus seems to have become established within L. Neagh, perhaps overshot and then senesced, with the native species re-establishing on the shoreline, with the invader mostly restricted to the deep mid-Lough. The non-amphipod macroinvertebrate assemblage was similar between the two surveys, in terms of Bray-Curtis community similarity, assemblage diversity, dominance and the taxa based ASPT water quality index. However, the mean density of macroinvertebrates (all taxa combined) was lower in 1999 compared to 1958, largely accounted for by a decline in oligochaete numbers. Since Gammarus species may be predators of other macroinvertebrates and influence their distribution and abundance, we investigated this trophic link in staged laboratory encounters. Both G. tigrinus and G. d. celticus preyed on isopods, alderflies, mayflies, chironomids and mysids, however, the native G. d. celticus had a significantly greater predatory impact on isopods and chironomids than did the invader G. tigrinus. While we cannot definitively ascribe cause and effect in the present scenario, we discuss how replacement of one amphipod species by another may have impacts on the wider macroinvertebrate assemblage.