The Common Shrew (Sorex araneus): A neglected host of tick-borne infections?

Although the importance of rodents as reservoirs for a number of tick-borne infections is well established, comparatively little is known about the potential role of shrews, despite them occupying similar habitats. To address this, blood and tick samples were collected from common shrews (Sorex araneus) and field voles (Microtus agrestis), a known reservoir of various tick-borne infections, from sites located within a plantation forest in northern England over a 2-year period. Of 647 blood samples collected from shrews, 121 (18.7%) showed evidence of infection with Anaplasma phagocytophilum and 196 (30.3%) with Babesia microti. By comparison, of 1505 blood samples from field voles, 96 (6.4%) were positive for A. phagocytophilum and 458 (30.4%) for Ba. microti. Both species were infested with the ticks Ixodes ricinus and Ixodes trianguliceps, although they had different burdens: on average, shrews carried almost six times as many I. trianguliceps larvae, more than twice as many I. ricinus larvae, and over twice as many nymphs (both tick species combined). The finding that the nymphs collected from shrews were almost exclusively I. trianguliceps highlights that this species is the key vector of these infections in this small mammal community. These findings suggest that common shrews are a reservoir of tick-borne infections and that the role of shrews in the ecology and epidemiology of tick-borne infections elsewhere needs to be comprehensively investigated

Experimental evidence that livestock grazing intensity affects cyclic vole population regulation processes

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Giant magnetoresistance of multiwall carbon nanotubes: modeling the tube/ferromagnetic-electrode burying contact

We report on the giant magnetoresistance (GMR) of multiwall carbon nanotubes with ultra small diameters. In particular, we consider the effect of the inter-wall interactions and the lead/nanotube coupling. Comparative studies have been performed to show that in the case when all walls are well coupled to the electrodes, the so-called inverse GMR can appear. The tendency towards a negative GMR depends on the inter-wall interaction and on the nanotube le ngth. If, however, the inner nanotubes are out of contact with one of the electrodes, the GMR remains positive even for relatively strong inter-wall interactions regardless of the outer nanotube length. These results shed additional light on recently reported experimental data, where an inverse GMR was found in some multiwall carbon nanotube samples.Comment: 5 pages, 5 figure

Size-mediated, density-dependent cannibalism in the signal crayfish Pacifastacus leniusculus (Dana, 1852) (Decapoda, Astacidea), an invasive crayfish in Britain

Many thanks to the University of Aberdeen who funded the project and Robert Laughton, director of the Findhorn, Nairn and Lossie Fisheries Trust, who provided useful field work advice and equipment. Thank you to Scottish Natural Heritage for support and facilitating the project with swift licensing (licence no. 22482). We would also like to acknowledge the Peoples Trust for Endangered Species (PTES) for their sponsoring of Connor Wood and for their support of our research. Many thanks also to Ewan McHenry for his assistance with data collection in the field.Peer reviewedPostprin

Evolution of predator dispersal in relation to spatio-temporal prey dynamics : how not to get stuck in the wrong place!

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Are silica defences in grasses driving vole population cycles?

Understanding the factors that drive species population dynamics is fundamental to biology. Cyclic populations of microtine rodents have been the most intensively studied to date, yet there remains great uncertainty over the mechanisms determining the dynamics of most of these populations. For one such population, we present preliminary evidence for a novel mechanism by which herbivore-induced reductions in plant quality alter herbivore life-history parameters and subsequent population growth. We tested the effect of high silica levels on the population growth and individual performance of voles (Microtus agrestis) reared on their winter food plant (Deschampsia caespitosa). In sites where the vole population density was high, silica levels in D. caespitosa leaves collected several months later were also high and vole populations subsequently declined; in sites where the vole densities were low, levels of silica were low and population density increased. High silica levels in their food reduced vole body mass by 0.5% a day. We argue that silica-based defences in grasses may play a key role in driving vole population cycles

On the viability of energy communities

Following the development of decentralized production technologies, energy communities have become a topic of increased interest. While the potential benefits have been described, we use the framework of cooperative game theory to test the ability of such communities to adequately share the gains. Indeed, despite the potential value created by such coalitions, there is no guarantee that they will be viable: a subset of participants may find it profitable to exit the community and create another one of their own. We take the case of a neighborhood, having access to a limited resource e.g. a shared roof or piece of land which they can exploit if they invest in some renewable production capacity. By joining the community, participants also enjoy aggregation gains in the form of reduced network fees. We find conditions depending on the structure of renewable installation costs, on the magnitude of the aggregation effect and coordination costs and, most importantly, on the chosen sharing rule, under which the whole energy community is stable. Efficiency could require the intervention of a social planner or a change in network tariff structures

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

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