241 research outputs found

    The Epidemiological Framework for Biological Invasions (EFBI): An interdisciplinary foundation for the assessment of biosecurity threats

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    Emerging microparasite (e.g. viruses, bacteria, protozoa and fungi) epidemics and the introduction of non-native pests and weeds are major biosecurity threats worldwide. The likelihood of these threats is often estimated from probabilities of their entry, establishment, spread and ease of prevention. If ecosystems are considered equivalent to hosts, then compartment disease models should provide a useful framework for understanding the processes that underpin non-native species invasions. To enable greater cross-fertilisation between these two disciplines, the Epidemiological Framework for Biological Invasions (EFBI) is developed that classifies ecosystems in relation to their invasion status: Susceptible, Exposed, Infectious and Resistant. These states are linked by transitions relating to transmission, latency and recovery. This viewpoint differs markedly from the species-centric approaches often applied to non-native species. It allows generalisations from epidemiology, such as the force of infection, the basic reproductive ratio R0, super-spreaders, herd immunity, cordon sanitaire and ring vaccination, to be discussed in the novel context of non-native species and helps identify important gaps in the study of biological invasions. The EFBI approach highlights several limitations inherent in current approaches to the study of biological invasions including: (i) the variance in non-native abundance across ecosystems is rarely reported; (ii) field data rarely (if ever) distinguish source from sink ecosystems; (iii) estimates of the susceptibility of ecosystems to invasion seldom account for differences in exposure to non-native species; and (iv) assessments of ecosystem susceptibility often confuse the processes that underpin patterns of spread within -and between- ecosystems. Using the invasion of lakes as a model, the EFBI approach is shown to present a new biosecurity perspective that takes account of ecosystem status and complements demographic models to deliver clearer insights into the dynamics of biological invasions at the landscape scale. It will help to identify whether management of the susceptibility of ecosystems, of the number of vectors, or of the diversity of pathways (for movement between ecosystems) is the best way of limiting or reversing the population growth of a non-native species. The framework can be adapted to incorporate increasing levels of complexity and realism and to provide insights into how to monitor, map and manage biological invasions more effectively

    Molecular Line Observations of Infrared Dark Clouds: Seeking the Precursors to Intermediate and Massive Star Formation

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    We have identified 41 infrared dark clouds from the 8 micron maps of the Midcourse Space Experiment (MSX), selected to be found within one square degree areas centered on known ultracompact HII regions. We have mapped these infrared dark clouds in N2H+(1-0), CS(2-1) and C18O(1-0) emission using the Five College Radio Astronomy Observatory. The maps of the different species often show striking differences in morphologies, indicating differences in evolutionary state and/or the presence of undetected, deeply embedded protostars. We derive an average mass for these clouds using N2H+ column densities of ~2500 solar masses, a value comparable to that found in previous studies of high mass star forming cores using other mass tracers. The linewidths of these clouds are typically ~2.0 - 2.9 km/s. Based on the fact that they are dark at 8 micron, compact, massive, and have large velocity dispersions, we suggest that these clouds may be the precursor sites of intermediate and high mass star formation.Comment: Accepted to ApJS, 22 pages, 10 pages of figures. For full-resolution images, see http://www.astro.lsa.umich.edu/~seragan/pubs/fcrao/figures.tar.g

    When Loss is More: From Managed Decline to Adaptive Release

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    This is the final version. Available on open access from Routledge via the DOI in this recordWithin the heritage sector there is widespread recognition that the accelerating effects of climate and other changes will necessitate reconsideration of the care of at-risk places and properties. Heritage organisations and agencies are developing new ways to identify and measure future threats, and to prioritise resources accordingly. For some designated assets, it is becoming clear, it may be necessary to manage processes of decline and transformation. Drawing on insights gathered from conversations with natural and historic environment practitioners and regulators, this paper highlights current practice and policy around managed decline, with a focus on the English context. In seeking to address some of the limitations of current approaches, this paper introduces a new conceptual framework: adaptive release. Adaptive release, as presented here, reflects a decision to accommodate the dynamic transformation of a heritage asset and its associated values and significance, with reference to wider landscape settings. The focus is on iterative management over extended timeframes, involving some relinquishment of control and a commitment to ongoing monitoring and interpretation. The concept of adaptive release is presented provisionally, rather than prescriptively, to expand the range of options available to natural and historic environment professionals in responding to inevitable change.Arts and Humanities Research Council (AHRC

    A restatement of recent advances in the natural science evidence base concerning neonicotinoid insecticides and insect pollinators

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    A summary is provided of recent advances in the natural science evidence base concerning the effects of neonicotinoid insecticides on insect pollinators in a format (a ‘restatement’) intended to be accessible to informed but not expert policymakers and stakeholders. Important new studies have been published since our recent review of this field (Godfray et al. 2014 Proc. R. Soc. B 281,20140558. (doi:10.1098/rspb.2014.0558)) and the subject continues to be an area of very active research and high policy relevance

    Human‐mediated dispersal and disturbance shape the metapopulation dynamics of a long‐lived herb

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    As anthropogenic impacts on the natural world escalate, there is increasing interest in the role of humans in dispersing seeds. But the consequences of this Human‐Mediated Dispersal (HMD) on plant spatial dynamics are little studied. In this paper, we ask how secondary dispersal by HMD affects the dynamics of a natural plant metapopulation. In addition to dispersal between patches, we suggest within‐patch processes can be critical. To address this, we assess how variation in local population dynamics, caused by small‐scale disturbances, affects metapopulation size. We created an empirically based model with stochastic population dynamics and dispersal among patches, which represented a real‐world, cliff‐top metapopulation of wild cabbage Brassica oleracea. We collected demographic data from multiple populations by tagging plants over eight years. We assessed seed survival, and establishment and survival of seedlings in intact vegetation vs. small disturbances. We modeled primary dispersal by wind using field data and used experimental data on secondary HMD by hikers. We monitored occupancy patterns over a 14‐yr period in the real metapopulation. Disturbance had large effects on local population growth rates, by increasing seedling establishment and survival. This meant that the modeled metapopulation grew in size only when the area disturbed in each patch was above 35%. In these growing metapopulations, although only 0.2% of seeds underwent HMD, this greatly enhanced metapopulation growth rates. Similarly, HMD allowed more colonizations in declining metapopulations under low disturbance, and this slowed the rate of decline. The real metapopulation showed patterns of varying patch occupancy over the survey years, which were related to habitat quality, but also positively to human activity along the cliffs, hinting at beneficial effects of humans. These findings illustrate that realistic changes to dispersal or demography, specifically by humans, can have fundamental effects on the viability of a species at the landscape scale

    Crisis care for children and young people with mental health problems: national mapping, models of delivery, sustainability and experience (CAMH-Crisis2). A study protocol.

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    Background One in six five 16-year-olds have a probable mental health difficulty. Of these, almost half of older teenagers and a quarter of 11–16-year-olds report having self-harmed or attempted suicide. Currently, there is little research into mental health crisis services for young people, with little understanding of what services exist, who uses them, or what works best. Question ‘How are mental health crisis responses for children and young people up to the age of 25 sustained, experienced and integrated within their local systems of services’? Objectives To describe National Health Service (NHS), local authority, education and third sector approaches to the implementation and organisation of crisis care for children and young people across England and Wales.To identify eight contrasting case studies in which to evaluate how crisis services have developed and are currently organised, sustained, experienced and integrated within the context of their local systems of services.To compare and contrast these services in the context of the available international evidence, drawing out and disseminating clear implications for the design and delivery of future crisis responses for children and young people and their families. Methods A sequential mixed methods approach, underpinned by normalisation process theory will be employed. A survey will create a detailed record of how crisis responses across England and Wales are organised, implemented and used. Subsequently, eight contrasting services in relation to geographic and socioeconomic setting, populations served, and service configuration will be identified as case studies. Interviews will be conducted with children, young people and parents/carers who have used the service, as well as commissioners, managers and practitioners. Operational policies and service usage data will also be examined. Analysis of how each service is provided, experienced, implemented and sustained will be conducted both inductively and deductively, reflecting normalisation process theory constructs.</ns4:p

    Research priorities for managing the impacts and dependencies of business upon food, energy, water and the environment

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    Delivering access to sufficient food, energy and water resources to ensure human wellbeing is a major concern for governments worldwide. However, it is crucial to account for the ‘nexus’ of interactions between these natural resources and the consequent implications for human wellbeing. The private sector has a critical role in driving positive change towards more sustainable nexus management and could reap considerable benefits from collaboration with researchers to devise solutions to some of the foremost sustainability challenges of today. Yet opportunities are missed because the private sector is rarely involved in the formulation of deliverable research priorities. We convened senior research scientists and influential business leaders to collaboratively identify the top forty questions that, if answered, would best help companies understand and manage their food-energy-water-environment nexus dependencies and impacts. Codification of the top order nexus themes highlighted research priorities around development of pragmatic yet credible tools that allow businesses to incorporate nexus interactions into their decision-making; demonstration of the business case for more sustainable nexus management; identification of the most effective levers for behaviour change; and understanding incentives or circumstances that allow individuals and businesses to take a leadership stance. Greater investment in the complex but productive relations between the private sector and research community will create deeper and more meaningful collaboration and cooperation.This work was supportedby the Economic and Social Research Council [Grant Number ES/L01632X/1] and is part of the Nexus Network Initiative. WJS is funded by Arcadia
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