1,135 research outputs found

    Beyond Katrina: Improving Disaster Response Capabilities

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    As Hurricanes Katrina, Rita, and Wilma successively lashed the Gulf Coast starting in late August 2005, nature’s fury exposed serious weaknesses in the United States’s emergency response capabilities. These problems were not simply the failure of particular places or leaders to be ready for disaster but rather an indication of more fundamental issues. These must be addressed if the country is to be ready for serious challenges that may lay ahead, whether severe natural disasters, outbreaks of emergent infectious disease, or renewed terrorist attacks

    Persistent gravitational radiation from glitching pulsars. II. Updated scaling with vortex number

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    Superfluid vortices pinned to nuclear lattice sites or magnetic flux tubes in a neutron star evolve abruptly through a sequence of metastable spatial configurations, punctuated by unpinning avalanches associated with rotational glitches, as the stellar crust spins down electromagnetically. The metastable configurations are approximately but not exactly axisymmetric, causing the emission of persistent, quasimonochromatic, current quadrupole gravitational radiation. The characteristic gravitational wave strain h0h_0 as a function of the spin frequency ff and distance DD from the Earth is bounded above by h0=1.2+1.3−0.9×10−32(f/30  Hz)2.5(D/1  kpc)−1h_0 = 1.2\substack{+1.3 \\ -0.9} \times 10^{-32} (f/30\;{\rm Hz})^{2.5} (D/1\;{\rm kpc})^{-1}, corresponding to a Poissonian spatial configuration (equal probability per unit area, i.e. zero inter-vortex repulsion), and bounded below by h0=1.8+2.0−1.5×10−50(f/30  Hz)1.5(D/1  kpc)−1h_0 = 1.8\substack{+2.0 \\ -1.5} \times 10^{-50} (f/30\;{\rm Hz})^{1.5} (D/1\;{\rm kpc})^{-1}, corresponding to a regular array (periodic separation, i.e.\ maximum inter-vortex repulsion). N-body point vortex simulations predict an intermediate scaling, h0=7.3+7.9−5.4×10−42(f/30  Hz)1.9(D/1  kpc)−1h_0 = 7.3\substack{+7.9 \\ -5.4} \times 10^{-42} (f/30\;{\rm Hz})^{1.9} (D/1\;{\rm kpc})^{-1}, which reflects a balance between the randomizing but spatially correlated action of superfluid vortex avalanches and the regularizing action of inter-vortex repulsion. The scaling is calibrated by conducting simulations with Nv≀5×103{N_{\rm v}} \leq 5\times10^3 vortices and extrapolated to the astrophysical regime Nv∌1017(f/30  Hz){N_{\rm v}} \sim 10^{17} (f/30\;{\rm Hz}). The scaling is provisional, pending future computational advances to raise Nv{N_{\rm v}} and include three-dimensional effects such as vortex tension and turbulence.Comment: 12 pages, 3 figures, accepted for publication in MNRA

    The role of the exit in the initial screening of investment opportunities: The case of business angel syndicate gatekeepers

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    The exit process has been largely ignored in business angel research.. The practitioner community identifies the difficulty in achieving exits as the most pressing problem for investors. This has been attributed to the failure of investors to adopt an exit-centric approach to investing. The validity of this claim is examined via a study of the investment approach of 21 ‘gatekeepers’ (managers) of angel groups in Scotland and Northern Ireland. Most gatekeepers say that they do consider the exit when they invest. However, this is contradicted by a verbal protocol analysis which indicates that the exit is not a significant consideration in their initial screening process. The small number of exits achieved by the groups is consistent with the general lack of an exit-centric approach to investing. Only three groups exhibit evidence of a strong exit-centric approach to investing. The lack of exits may have a negative impact on the level of future angel investment activity

    The Strategic Exploitation of Limited Information and Opportunity in Networked Markets

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    This paper studies the effect of constraining interactions within a market. A model is analysed in which boundedly rational agents trade with and gather information from their neighbours within a trade network. It is demonstrated that a trader’s ability to profit and to identify the equilibrium price is positively correlated with its degree of connectivity within the market. Where traders differ in their number of potential trading partners, well-connected traders are found to benefit from aggressive trading behaviour.Where information propagation is constrained by the topology of the trade network, connectedness affects the nature of the strategies employed

    A manifesto for researching entrepreneurial ecosystems

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    Entrepreneurial ecosystems are the focus of government economic policies around the world for their potential to generate entrepreneur-led economic development. The paper identifies key research questions and challenges to building effective public policy: (i) the limitations of existing data sources, (ii) the need to balance findings from quantitative and qualitative studies, (iii) the danger that entrepreneurial ecosystems will be just a policy fad, (iv) the narrow focus of policy and research on high tech firms and scale-ups, and (v) the need to balance research approaches between simplified models and a complex systems approach. There is a need for a better understanding of the diversity of policy contexts (level of government, country context) and model of ecosystem governance. A more granulated understanding of ecosystem thinking is required, with greater consideration of the diversity of actors and the institutional context, with more attention given to the heterogeneous nature of places and complex interactions between actors and networks. Looking to the future, the potential of new data sources and methodologies is identified. Future research should give greater consideration to the institutional context to understand how policy can better support entrepreneurial activity and the extent to which specific policies can be replicated elsewhere

    Paedophiles in the community: inter-agency conflict, news leaks and the local press

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    This article explores the leaking of confidential information about secret Home Office plans to house convicted paedophiles within a local community (albeit inside a prison). It argues that a politics of paedophilia has emerged in which inter-agency consensus on the issue of ‘what to do’ with high-profile sex offenders has broken down. Accordingly, the article situates newspaper ‘outing’ of paedophiles in the community in relation to vigilante journalism and leaked information from official agencies. The article then presents research findings from a case study of news events set in train following a whistle-blowing reaction by Prison Officers’ Association officials to Home Office plans. Drawing from a corpus of 10 interviews with journalists and key protagonists in the story, the article discusses both the dynamics of whistle blowing about paedophiles and also what happens after the whistle has blown

    Does R&D, human capital and FDI matter for TFP in OECD countries?

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    This study investigates the interplay between research and development (R&D), human capital (HC), foreign direct investment (FDI) and total factor productivity (TFP) in OECD countries. We divide the sample into two sub-groups; the European and the non-European states so as to account for underlying country heterogeneity. The analysis follows a panel data approach over the period 1995–2015, taking into account the modelling on non-stationarity, long-run relationships and short-run dynamics with a panel VAR. Both R&D and HC have a positive effect on TFP, whilst FDI has a positive and significant effect only in the case of non-European countries. Moreover, the contribution of R&D is higher than that of HC and FDI in all cases. Thus, based on these findings, policymakers should design and implement policies to increase resources invested in R&D, with a consistent ongoing spending review, to attract foreign direct investment, especially for the majority of the European and some of the non-European countries and to improve education system on a more productive innovation and research base
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