638 research outputs found

    Cryo-FIB Machining: An Alternative to TEM Cryo-Sections Cut with Diamonds?

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    Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7-August 11, 201

    Shrub expansion in tundra ecosystems: dynamics, impacts and research priorities

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    Part of Focus on Dynamics of Arctic and Sub-Arctic Vegetation Recent research using repeat photography, long-term ecological monitoring and dendrochronology has documented shrub expansion in arctic, high-latitude and alpine tundra ecosystems. Here, we (1) synthesize these findings, (2) present a conceptual framework that identifies mechanisms and constraints on shrub increase, (3) explore causes, feedbacks and implications of the increased shrub cover in tundra ecosystems, and (4) address potential lines of investigation for future research. Satellite observations from around the circumpolar Arctic, showing increased productivity, measured as changes in 'greenness', have coincided with a general rise in high-latitude air temperatures and have been partly attributed to increases in shrub cover. Studies indicate that warming temperatures, changes in snow cover, altered disturbance regimes as a result of permafrost thaw, tundra fires, and anthropogenic activities or changes in herbivory intensity are all contributing to observed changes in shrub abundance. A large-scale increase in shrub cover will change the structure of tundra ecosystems and alter energy fluxes, regional climate, soil–atmosphere exchange of water, carbon and nutrients, and ecological interactions between species. In order to project future rates of shrub expansion and understand the feedbacks to ecosystem and climate processes, future research should investigate the species or trait-specific responses of shrubs to climate change including: (1) the temperature sensitivity of shrub growth, (2) factors controlling the recruitment of new individuals, and (3) the relative influence of the positive and negative feedbacks involved in shrub expansion

    Recent dynamics of arctic and sub-arctic vegetation

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    We present a focus issue of Environmental Research Letters on the 'Recent dynamics of arctic and sub-arctic vegetation'. The focus issue includes three perspective articles (Verbyla 2011 Environ. Res. Lett. 6 041003, Williams et al 2011 Environ. Res. Lett. 6 041004, Loranty and Goetz 2012 Environ. Res. Lett. 7 011005) and 22 research articles. The focus issue arose as a result of heightened interest in the response of high-latitude vegetation to natural and anthropogenic changes in climate and disturbance regimes, and the consequences that these vegetation changes might have for northern ecosystems. A special session at the December 2010 American Geophysical Union Meeting on the 'Greening of the Arctic' spurred the call for papers. Many of the resulting articles stem from intensive research efforts stimulated by International Polar Year projects and the growing acknowledgment of ongoing climate change impacts in northern terrestrial ecosystems.</p

    Rewriting the Constitution::A Critique of 'Postphenomenology''

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    This paper builds a three part argument in favour of a more transcendentally focused form of 'postphenomenology' than is currently practised in philosophy of technology. It does so by problematising two key terms, 'constitution' and 'postphenomenology', then by arguing in favour of a 'transcendental empiricist' approach that draws on the work of Foucault, Derrida, and, in particular, Deleuze. Part one examines 'constitution', as it moves from the context of Husserl's phenomenology to Ihde and Verbeek's 'postphenomenology'. I argue that the term tends towards different senses in these contexts, and that this renders its sense more problematic than the work of Ihde and Verbeek makes it appear. Part two examines 'postphenomenology'. I argue that putatively 'poststructuralist' thinkers such as Derrida, Foucault and Deleuze may be better characterised as 'postphenomenologists', and that approaching them in this way may allow better access to their work from a philosophy of technology perspective. Part three argues for a 'transcendental empiricist' approach to philosophy of technology. In doing so, it argues for a rewriting of contemporary philosophy of technology's political constitution: since an 'empirical turn' in the 1990s, I argue, philosophy of technology has been too narrowly focused on 'empirical' issues of fact, and not focused enough on 'transcendental' issues concerning conditions for these facts.<br/

    The (im)materiality of literacy : the significance of subjectivity to new literacies research.

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    This article deconstructs the online and offline experience to show its complexities and idiosyncratic nature. It proposes a theoretical framework designed to conceptualise aspects of meaning-making across on- and offline contexts. In arguing for the ‘(im)materiality’ of literacy, it makes four propositions which highlight the complex and diverse relationships between the immaterial and material associated with meaning-making. Complementing existing sociocultural perspectives on literacy, the article draws attention to the significance of relationships between space, mediation, materiality and embodiment to literacy practices. This in turn emphasises the importance of the subjective in understanding how different locations, experiences and so forth inflect literacy practice. The article concludes by drawing on the Deleuzian concept of the ‘baroque’ to suggest that this focus on articulations between the material and immaterial helps us to see literacy as multiply and flexibly situated

    Change or control? Developing dialogues between research and public protection

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    This paper aims to scope out some of the implications of desistance research for the community management of high risk offenders. Acknowledging the limited empirical research exploring this interface, this paper outlines the evolving evidence base and what this tells us about the process of desistance and what supports it. The evidence as to whether 'high risk offenders' desist and what we know about this process is discussed prior to outlining the landscape of current and principal practice approaches which can be located in the community/public protection model. Potential dialogues between desistance research and public protection practices are discussed to explore ensuing implications and opportunities for practice

    Securing the Anthropocene? International Policy Experiments in Digital Hacktivism: A Case Study of Jakarta

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    This article analyses security discourses that are beginning to self-consciously take on board the shift towards the Anthropocene. Firstly, it sets out the developing episteme of the Anthropocene, highlighting the limits of instrumentalist cause-and-effect approaches to security, increasingly becoming displaced by discursive framings of securing as a process, generated through new forms of mediation and agency, capable of grasping inter-relations in a fluid context. This approach is the methodology of hacking: creatively composing and repurposing already existing forms of agency. It elaborates on hacking as a set of experimental practices and imaginaries of securing the Anthropocene, using as a case study the field of digital policy activism with the focus on community empowerment through social-technical assemblages being developed and applied in ‘the City of the Anthropocene’: Jakarta, Indonesia. The article concludes that policy interventions today cannot readily be grasped in modernist frameworks of ‘problem solving’ but should be seen more in terms of evolving and adaptive ‘life hacks’
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