9,066 research outputs found

    Private experiments in global governance : primary commodity roundtables and the politics of deliberation

    Get PDF
    Emerging scholarship on global governance offers ever-more detailed analyses of private regulatory regimes. These regimes aim to regulate some area of social activity without a mandate from, or participation of, states or international organizations. While there are numerous empirical studies of these regimes, the normative theoretical literature has arguably struggled to keep pace with such developments. This is unfortunate, as the proliferation of private regulatory regimes raises important issues about legitimacy in global governance. The aim of this paper is to address some of these issues by elaborating a theoretical framework that can orientate normative investigation of these schemes. It does this through turning to the idea of experimentalist governance. It is argued that experimentalism can provide an important and provocative set of insights about the processes and logics of emerging governance schemes. The critical purchase of this theory is illustrated through an application to the case of primary commodities roundtables, part of ongoing attempts by NGOs, producers, and buyers to set sustainability criteria for commodity production across a range of sectors. The idea of experimentalist governance, we argue, can lend much needed theoretical structure to debates about the normative legitimacy of private regulatory regimes

    Configuration spaces of products

    Full text link
    We show that the configuration spaces of a product of parallelizable manifolds may be recovered from those of the factors as the Boardman-Vogt tensor product of right modules over the operads of little cubes of the appropriate dimension. We also discuss an analogue of this result for manifolds that are not necessarily parallelizable, which involves a new operad of skew little cubes.Comment: 21 pages, 1 figure. To appear in Transactions of the AMS. May vary slightly from published versio

    Funding: Patterns and Guideposts in the Nonprofit Sector

    Get PDF
    Although funding is a pressing concern for nonprofit organizations across the United States, detailed information about how dollars flow within the sector is hard to come by. For example, are there distinct patterns to the ways in which nonprofit organizations are funded? If the answer to this question is "yes," those patterns could provide important "guideposts" for similar organizations planning their funddevelopment strategies.To begin answering this question, the Bridgespan Group researched the funding for three samples of nonprofit organizations using Form 990 returns, complemented by company-specific reports and personal interviews. 1. The largest organizations tend to rely on a single type of funding for the majority of their revenue, rather than having a balanced mix from a variety of funders. Among youth services and environmental advocacy organizations, there are distinct transition points across a spectrum ofrevenue sizes where organizations move from heterogeneous to singletypefunding.2. Among the largest organizations, the kind of work an organization does influences, but does not dictate, the identity of its dominant funding type.3. In the fields we selected for in-depth analysis -- youth services and environmental advocacy -- growth to a significant size is extremely rare, and the largest organizations control most of the resources.4. In youth services and environmental advocacy, there seem to be transition points in the typical funding mix used by organizations of different sizes, suggesting that the size of an organization influences its dominant funding type

    A Dynamics and Stability Framework for Avian Jumping Take-off

    Full text link
    Jumping take-off in birds is an explosive behaviour with the goal of providing a rapid transition from ground to airborne locomotion. An effective jump is predicated on the need to maintain dynamic stability through the acceleration phase. The present study concerns understanding how birds retain control of body attitude and trajectory during take-off. Cursory observation suggests that stability is achieved with relatively little cost. However, analysis of the problem shows that the stability margins during jumping are actually very small and that stability considerations play a significant role in selection of appropriate jumping kinematics. We use theoretical models to understand stability in prehensile take-off (from a perch) and also in non-prehensile take-off (from the ground). The primary instability is tipping, defined as rotation of the centre of gravity about the ground contact point. Tipping occurs when the centre of pressure falls outside the functional foot. A contribution of the paper is the development of graphical tipping stability margins for both centre of gravity location and acceleration angle. We show that the nose-up angular acceleration extends stability bounds forward and is hence helpful in achieving shallow take-offs. The stability margins are used to interrogate simulated take-offs of real birds using published experimental kinematic data from a guinea fowl (ground take-off) and a diamond dove (perch take-off). For the guinea fowl the initial part of the jump is stable, however simulations exhibit a stuttering instability not observed experimentally that is probably due to absence of compliance in the idealised joints. The diamond dove model confirms that the foot provides an active torque reaction during take-off, extending the range of stable jump angles by around 45{\deg}.Comment: 21 pages, 11 figures; supplementary material: https://figshare.com/s/86b12868d64828db0d5d; DOI: 10.6084/m9.figshare.721056

    Living on the Edge: A Toy Model for Holographic Reconstruction of Algebras with Centers

    Full text link
    We generalize the Pastawski-Yoshida-Harlow-Preskill (HaPPY) holographic quantum error-correcting code to provide a toy model for bulk gauge fields or linearized gravitons. The key new elements are the introduction of degrees of freedom on the links (edges) of the associated tensor network and their connection to further copies of the HaPPY code by an appropriate isometry. The result is a model in which boundary regions allow the reconstruction of bulk algebras with central elements living on the interior edges of the (greedy) entanglement wedge, and where these central elements can also be reconstructed from complementary boundary regions. In addition, the entropy of boundary regions receives both Ryu-Takayanagi-like contributions and further corrections that model the ÎŽArea4GN\frac{\delta \text{Area}}{4G_N} term of Faulkner, Lewkowycz, and Maldacena. Comparison with Yang-Mills theory then suggests that this ÎŽArea4GN\frac{\delta \text{Area}}{4G_N} term can be reinterpreted as a part of the bulk entropy of gravitons under an appropriate extension of the physical bulk Hilbert space.Comment: 20 pages, 11 figure

    Geometry shapes evolution of early multicellularity

    Full text link
    Organisms have increased in complexity through a series of major evolutionary transitions, in which formerly autonomous entities become parts of a novel higher-level entity. One intriguing feature of the higher-level entity after some major transitions is a division of reproductive labor among its lower-level units. Although it can have clear benefits once established, it is unknown how such reproductive division of labor originates. We consider a recent evolution experiment on the yeast Saccharomyces cerevisiae as a unique platform to address the issue of reproductive differentiation during an evolutionary transition in individuality. In the experiment, independent yeast lineages evolved a multicellular "snowflake-like'' cluster form in response to gravity selection. Shortly after the evolution of clusters, the yeast evolved higher rates of cell death. While cell death enables clusters to split apart and form new groups, it also reduces their performance in the face of gravity selection. To understand the selective value of increased cell death, we create a mathematical model of the cellular arrangement within snowflake yeast clusters. The model reveals that the mechanism of cell death and the geometry of the snowflake interact in complex, evolutionarily important ways. We find that the organization of snowflake yeast imposes powerful limitations on the available space for new cell growth. By dying more frequently, cells in clusters avoid encountering space limitations, and, paradoxically, reach higher numbers. In addition, selection for particular group sizes can explain the increased rate of apoptosis both in terms of total cell number and total numbers of collectives. Thus, by considering the geometry of a primitive multicellular organism we can gain insight into the initial emergence of reproductive division of labor during an evolutionary transition in individuality.Comment: 7 figure

    Nanoparticles in explosives detection – the state-of-the-art and future directions

    Get PDF
    No abstract available

    A two-component transport model for solar wind fluctuations: Waves plus quasi-2D turbulence

    Get PDF
    We present a model for the transport of solar wind fluctuations, based on the assumption that they can be well-represented using two distinct components: a quasi-2D turbulence piece and a wave-like piece. For each component, coupled transport equations for its energy, cross helicity, and characteristic lengthscale(s) are derived, along with an equation for the proton temperature. This energy-containing “two-component” model includes the effects of solar wind expansion and advection, driving by stream shear and pickup ions, and nonlinear cascades. Nonlinear effects are modeled using a recently developed one-point phenomenology for such a two-component model of homogeneous MHD turbulence [1]. Heating due to these nonlinear effects is included in the temperature equation. Numerical solutions are discussed and compared with observation
    • 

    corecore