Exploration for volcanogenic sulphide mineralisation at Benglog, north Wales

Exploration for volcanogenic sulphide mineralisation around Benglog is one of three investigations designed to assess the metallogenic potential of the Ordovician Aran Volcanic Group. Detailed geological mapping in the Benglog area enabled an interpretation of the volcanic environment, critical to such an assessment, to be made. The eruptive rocks are acid and basic in composition; the acid rocks are mostly ash-flow tuffs derived from outside the area, whereas the basic rocks have a local derivation. They are all interbedded with dark grey or black silty mudstone and were probably erupted in a submarine environment. Contemporaneous dolerite sills were intruded into wet sediment. This environment was suitable for volcanogenic exhalative sulphide deposits to form and indications of a metallogenic horizon were found at the top of the Y Fron Formation in the form of abundant pyrite, minor pyrrhotite and minor base metal enrichment. Soil samples, analysed for copper, lead and zinc, were collected and geophysical surveys were carried out along eleven east-west trending traverse lines 300 m apart across the volcanic succession. Indications were found of minor vein mineralisation at dolerite intrusion margins and locally along faults. Very high chargeability and low resistivity anomalies over mudstones did not spatially coincide with geochemical anomalies in soil, but the secondary redistribution of metals in soils and variable thickness of overburden precluded confident interpretation of the source of many soil anomalies. Geochemical drainage data, in conjunction with rock analyses, show strong barium enrichment in mudstones which could be volcanogenic in origin but related to two separate eruptive episodes. The findings of the survey were inconclusive. An environment suitable for the formation of volcanogenic exhalative sulphide deposits was established, but the geochemical and geophysical surveys located only minor vein mineralisation and tenuous indications of other styles of mineralisation. Recommendations are made for further work

Identification of a mutation in the para-sodium channel gene of the cattle tick Rhipicephalus (Boophilus) microplus associated with resistance to synthetic pyrethroid acaricides

Resistance against synthetic pyrethroid (SP) products for the control of cattle ticks in Australia was detected in the field in 1984, within a very short time of commercial introduction. We have identified a mutation in the domain II S4-5 linker of the para-sodium channel that is associated with resistance to SPs in the cattle tick Rhipicephalus (Boophilus) microplus from Australia. The cytosine to adenine mutation at position 190 in the R. microplus sequence AF134216, results in an amino acid substitution from leucine in the susceptible strain to isoleucine in the resistant strain. A similar mutation has been shown to confer SP resistance in the whitefly, Bemisia tabaci, but has not been described previously in ticks. A diagnostic quantitative PCR assay has been developed using allele-specific Taqman® minor groove-binding (MGB) probes. Using the assay to screen field and laboratory populations of ticks showed that homozygote allelic frequencies correlated highly with the survival percentage at the discriminating concentration of cypermethrin

On the dispersion of fundamental particles in QCD and N=4 Super Yang-Mills theory

We study thermal corrections to the dispersion relations of massive fundamental particles immersed in weakly coupled non-Abelian plasmas. The cases covered include quarks in the QCD (quark-gluon) plasma, as well as N=2 quarks and scalars in an N=4 Super Yang-Mills plasma. We perform the calculations to leading order in a weak coupling expansion, and consider all mass scales of the fundamental fields, ranging from massless particles all the way to bare masses parametrically larger than the temperature.Comment: 41 pages, 8 figures; v2 to be published in JHEP, with one table added to summarize result

Second Harmonic Generation for a Dilute Suspension of Coated Particles

We derive an expression for the effective second-harmonic coefficient of a dilute suspension of coated spherical particles. It is assumed that the coating material, but not the core or the host, has a nonlinear susceptibility for second-harmonic generation (SHG). The resulting compact expression shows the various factors affecting the effective SHG coefficient. The effective SHG per unit volume of nonlinear coating material is found to be greatly enhanced at certain frequencies, corresponding to the surface plasmon resonance of the coated particles. Similar expression is also derived for a dilute suspension of coated discs. For coating materials with third-harmonic (THG) coefficient, results for the effective THG coefficients are given for the cases of coated particles and coated discs.Comment: 11 pages, 3 figures; accepted for publication in Phys. Rev.

Host-parasite biology in the real world: the field voles of Kielder

Peer reviewedPublisher PD

Peer support for people living with rare or young onset dementia: An integrative review

Objectives: The aim of this integrative review was to identify and synthesize the literature on peer support interventions for people living with or caring for someone with a rare or young onset dementia. Design: A literature search of articles was performed using the Nipissing University Primo search system, a central index that enables simultaneous searches across databases which included MEDLINE (PubMed), Web of Science, PsycINFO, CINAHL, Sociological Abstracts, Cochrane Library. Results: The eleven papers that met the inclusion criteria spanned eighteen years and from five countries. Studies reported on peer support programs that were either hospital-based (n = 6) or community-based (n = 4), and were predominantly led by disciplines in the health sciences. Only one study did not involve delivering services. There was a range of methodological quality within the studies included in the review. Further analysis and synthesis led to the identification of three overarching peer support themes. These included: (1) peers as necessarily part of social support interventions; (2) a theoretical portmanteau; and (3) dementia spaces and relationality. Conclusion: Consistent with a much larger body of work examining peer involvement in social interventions, this review reinforced the valuable contribution of peers. A full understanding of the mechanisms of change was not achieved. Notwithstanding, the issue of studies neglecting to sufficiently conceptualize and describe interventions is an important one – drawing attention to the need to continue to explore varied delivery, including co-produced models, and more effective evaluation strategies to inform the dementia care sector

Understanding pattern scaling errors across a range of emissions pathways

The regional climate impacts of hypothetical future emissions scenarios can be estimated by combining Earth system model simulations with a linear pattern scaling model such as MESMER (Modular Earth System Model Emulator with spatially Resolved output), which uses estimated patterns of the local response per degree of global temperature change. Here we use the mean trend component of MESMER to emulate the regional pattern of the surface temperature response based on historical single-forcer and future Shared Socioeconomic Pathway (SSP) CMIP6 (Coupled Model Intercomparison Project Phase 6) simulations. Errors in the emulations for selected target scenarios (SSP1–1.9, SSP1–2.6, SSP2–4.5, SSP3–7.0, and SSP5–8.5) are decomposed into two components, namely (1) the differences in scaling patterns between scenarios as a consequence of varying combinations of external forcings and (2) the intrinsic time series differences between the local and global responses in the target scenario. The time series error is relatively small for high-emissions scenarios, contributing around 20 % of the total error, but is similar in magnitude to the pattern error for lower-emissions scenarios. This irreducible time series error limits the efficacy of linear pattern scaling for emulating strong mitigation pathways and reduces the dependence on the predictor pattern used. The results help guide the choice of predictor scenarios for simple climate models and where to target for the introduction of other dependent variables beyond global surface temperature into pattern scaling models

Energy dissipation in wave propagation in general relativistic plasma

Based on a recent communication by the present authors the question of energy dissipation in magneto hydrodynamical waves in an inflating background in general relativity is examined. It is found that the expanding background introduces a sort of dragging force on the propagating wave such that unlike the Newtonnian case energy gets dissipated as it progresses. This loss in energy having no special relativistic analogue is, however, not mechanical in nature as in elastic wave. It is also found that the energy loss is model dependent and also depends on the number of dimensions.Comment: 12 page

A General Backwards Calculus of Variations via Duality

We prove Euler-Lagrange and natural boundary necessary optimality conditions for problems of the calculus of variations which are given by a composition of nabla integrals on an arbitrary time scale. As an application, we get optimality conditions for the product and the quotient of nabla variational functionals.Comment: Submitted to Optimization Letters 03-June-2010; revised 01-July-2010; accepted for publication 08-July-201

On the evolution of cosmic-superstring networks

We model the behaviour of a network of interacting (p,q) strings from IIB string theory by considering a field theory containing multiple species of string, allowing us to study the effect of non-intercommuting events due to two different species crossing each other. This then has the potential for a string dominated Universe with the network becoming so tangled that it freezes. We give numerical evidence, explained by a one-scale model, that such freezing does not take place, with the network reaching a scaling limit where its density relative to the background increases with N, the number of string types.Comment: Extra references added showing constraints on cosmic superstrings, 7 pages, 7 figure