396 research outputs found

    Collective frequencies and metastability in networks of limit-cycle oscillators with time delay

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    We analyze the dynamic behavior of large two-dimensional systems of limit-cycle oscillators with random intrinsic frequencies that interact via time-delayed nearest-neighbor coupling. We find that even small delay times lead to a novel form of frequency depression where the system decays to stable states which oscillate at a delay and interaction-dependent reduced collective frequency. For greater delay or tighter coupling between oscillators we find metastable synchronized states that we describe analytically and numerically

    Oscillator-phase coupling for different two-dimensional network connectivities

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    We investigate the dynamics of large arrays of coupled phase oscillators driven by random intrinsic frequencies under a variety of coupling schemes, by computing the time-dependent cross-correlation function numerically for a two-dimensional array consisting of 128Ă—128 oscillators as well as analytically for a simpler model. Our analysis shows that for overall equal interaction strength, a sparse-coupling scheme in which each oscillator is coupled to a small, randomly selected subset of its neighbors leads to a more rapid and robust phase locking than nearest-neighbor coupling or locally dense connection schemes

    Not bound but Committed: operationalising the Global Compact on Refugees

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    The Global Compact on Refugees is not legally binding, but it gives rise to commitments by the international community as a whole. It is also rooted in international refugee law, international human rights law and international humanitarian law. This article addresses how the GCR can not give rise to binding obligations in international law, yet provide for enhanced protection and assistance to refugees and hosting communities, and establish commitments for fairer and more predictable burden- and responsibility-sharing. It does this by reference to other non-legally binding international documents and rule of law. Additionally, the use of indicators to measure states' and other international actors' performance in operationalising the GCR necessarily provides a framework to measure commitments; coupled with greater humanitarian and development co-operation, commitments can be better facilitated even if the GCR is not legally binding. Burden- and responsibility-sharing is fulfilled through the emphasis on solutions, too

    Muddled Boundaries of Digital Shrines

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    International audienceBased on an online ethnography study of 274 YouTube videos posted during the Virginia Tech or the Newtown massacres, this article discusses how users resort to participatory media during such mediatized events to create a digital spontaneous shrine. The assemblage of this sanctuary on a website hosting billions of user-generated contents is made possible by means of folksonomy and website architecture, and a two-fold social dynamic based on participatory commitment and the institutionalization of a collective entity. Unlike “physical” spontaneous shrines erected in public spaces, these digital shrines connect the bereaved with provocative or outrageous contributions, notably tributes from school shooting fans using participatory media to commemorate the killer’s memory. This side effect, generated by the technical properties of the platform, compromises the tranquility of the memorial and muddles the boundaries and the contents of such sanctuaries

    Evaluation of a proposal for reliable low-cost grid power with 100% wind, water, and solar

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    A number of analyses, meta-Analyses, and assessments, including those performed by the Intergovernmental Panel on Climate Change, the National Oceanic and Atmospheric Administration, the National Renewable Energy Laboratory, and the International Energy Agency, have concluded that deployment of a diverse portfolio of clean energy technologies makes a transition to a low-carbon-emission energy system both more feasible and less costly than other pathways. In contrast, Jacobson et al. [Jacobson MZ, Delucchi MA, Cameron MA, Frew BA (2015) Proc Natl Acad Sci USA 112(49):15060-15065] argue that it is feasible to provide low-cost solutions to the grid reliability problem with 100% penetration of WWS [wind, water and solar power] across all energy sectors in the continental United States between 2050 and 2055 , with only electricity and hydrogen as energy carriers. In this paper, we evaluate that study and find significant shortcomings in the analysis. In particular, we point out that this work used invalid modeling tools, contained modeling errors, and made implausible and inadequately supported assumptions. Policy makers should treat with caution any visions of a rapid, reliable, and low-cost transition to entire energy systems that relies almost exclusively on wind, solar, and hydroelectric power

    Chemical Addressability of Ultraviolet-Inactivated Viral Nanoparticles (VNPs)

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    . Thus, inactivation of the virus RNA genome is important for biosafety considerations, however the surface characteristics and chemical reactivity of the particles must be maintained in order to preserve chemical and structural functionality. were shown to maintain particle structure and chemical reactivity, and cellular binding properties were similar to CPMV-WT. applications

    A description of a knowledge broker role implemented as part of a randomized controlled trial evaluating three knowledge translation strategies

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    <p>Abstract</p> <p>Background</p> <p>A knowledge broker (KB) is a popular knowledge translation and exchange (KTE) strategy emerging in Canada to promote interaction between researchers and end users, as well as to develop capacity for evidence-informed decision making. A KB provides a link between research producers and end users by developing a mutual understanding of goals and cultures, collaborates with end users to identify issues and problems for which solutions are required, and facilitates the identification, access, assessment, interpretation, and translation of research evidence into local policy and practice. Knowledge-brokering can be carried out by individuals, groups and/or organizations, as well as entire countries. In each case, the KB is linked with a group of end users and focuses on promoting the integration of the best available evidence into policy and practice-related decisions.</p> <p>Methods</p> <p>A KB intervention comprised one of three KTE interventions evaluated in a randomized controlled trial.</p> <p>Results</p> <p>KB activities were classified into the following categories: initial and ongoing needs assessments; scanning the horizon; knowledge management; KTE; network development, maintenance, and facilitation; facilitation of individual capacity development in evidence informed decision making; and g) facilitation of and support for organizational change.</p> <p>Conclusion</p> <p>As the KB role developed during this study, central themes that emerged as particularly important included relationship development, ongoing support, customized approaches, and opportunities for individual and organizational capacity development. The novelty of the KB role in public health provides a unique opportunity to assess the need for and reaction to the role and its associated activities. Future research should include studies to evaluate the effectiveness of KBs in different settings and among different health care professionals, and to explore the optimal preparation and training of KBs, as well as the identification of the personality characteristics most closely associated with KB effectiveness. Studies should also seek to better understand which combination of KB activities are associated with optimal evidence-informed decision making outcomes, and whether the combination changes in different settings and among different health care decision makers.</p
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