7,823 research outputs found

    Local Food Systems: Concepts, Impacts, and Issues

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    This comprehensive overview of local food systems explores alternative definitions of local food, estimates market size and reach, describes the characteristics of local consumers and producers, and examines early indications of the economic and health impacts of local food systems. There is no consensus on a definition of “local” or “local food systems” in terms of the geographic distance between production and consumption. But defining “local” based on marketing arrangements, such as farmers selling directly to consumers at regional farmers’ markets or to schools, is well recognized. Statistics suggest that local food markets account for a small, but growing, share of U.S. agricultural production. For smaller farms, direct marketing to consumers accounts for a higher percentage of their sales than for larger farms. Findings are mixed on the impact of local food systems on local economic development and better nutrition levels among consumers, and sparse literature is so far inconclusive about whether localization reduces energy use or greenhouse gas emissions.local food systems, farmers’ markets, direct-to-consumer marketing, direct-to-retail/ foodservice marketing, community supported agriculture, farm to school programs, Farmers’ Market Promotion Program, food miles, Community/Rural/Urban Development,

    The stellar velocity dispersion in the inner 1.3 disk scale-lengths of the irregular galaxy NGC 4449

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    We present measurements of the stellar velocity dispersion in the inner 1 arcmin radius (1.3 disk scale-lengths) of the irregular galaxy NGC 4449 determined from long-slit absorption-line spectra. The average observed dispersion is 29 +/-2 km/s, the same as predicted from NGC 4449's luminosity. No significant rotation in the stars is detected. If we assume a maximum rotation speed of the stars from the model determined from the gas kinematics of Hunter et al. (2002), the ratio V_max/sigma_z measured globally is 3. This ratio is comparable to values measured in spiral galaxies, and implies that the stellar disk in NGC 4449 is kinematically relatively cold. The intrinsic minor-to-major axis ratio (b/a)_0 is predicted to be in the range 0.3-0.6, similar to values derived from the distribution of observed b/a of Im galaxies. However, V/sigma_z measured locally is 0.5-1.1, and so the circular velocity of NGC 4449 is comparable or less than the velocity of the stars within the central 1.3 disk scale-lengths of the galaxy.Comment: To be published in ApJ, Nov 200

    Influence of chronic L-DOPA treatment on immune response following allogeneic and xenogeneic graft in a rat model of Parkinson's disease

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    Although intrastriatal transplantation of fetal cells for the treatment of Parkinson’s disease had shown encouraging results in initial open-label clinical trials, subsequent double-blind studies reported more debatable outcomes. These studies highlighted the need for greater preclinical analysis of the parameters that may influence the success of cell therapy. While much of this has focused on the cells and location of the transplants, few have attempted to replicate potentially critical patient centered factors. Of particular relevance is that patients will be under continued L-DOPA treatment prior to and following transplantation, and that typically the grafts will not be immunologically compatible with the host. The aim of this study was therefore to determine the effect of chronic L-DOPA administered during different phases of the transplantation process on the survival and function of grafts with differing degrees of immunological compatibility. To that end, unilaterally 6-OHDA lesioned rats received sham surgery, allogeneic or xenogeneic transplants, while being treated with L-DOPA before and/or after transplantation. Irrespective of the L-DOPA treatment, dopaminergic grafts improved function and reduced the onset of L-DOPA induced dyskinesia. Importantly, although L-DOPA administered post transplantation was found to have no detrimental effect on graft survival, it did significantly promote the immune response around xenogeneic transplants, despite the administration of immunosuppressive treatment (cyclosporine). This study is the first to systematically examine the effect of L-DOPA on graft tolerance, which is dependent on the donor-host compatibility. These findings emphasize the importance of using animal models that adequately represent the patient paradigm

    IllustrisTNG and S2COSMOS: possible conflicts in the evolution of neutral gas and dust

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    We investigate the evolution in galactic dust mass over cosmic time through (i) empirically derived dust masses using stacked submillimetre fluxes at 850 μm in the COSMOS field and (ii) dust masses derived using a robust post-processing method on the results from the cosmological hydrodynamical simulation IllustrisTNG. We effectively perform a ‘self-calibration’ of the dust mass absorption coefficient by forcing the model and observations to agree at low redshift and then compare the evolution shown by the observations with that predicted by the model. We create dust mass functions (DMFs) based on the IllustrisTNG simulations from 0 < z < 0.5 and compare these with previously observed DMFs. We find a lack of evolution in the DMFs derived from the simulations, in conflict with the rapid evolution seen in empirically derived estimates of the low-redshift DMF. Furthermore, we observe a strong evolution in the observed mean ratio of dust mass to stellar mass of galaxies over the redshift range 0 < z < 5, whereas the corresponding dust masses from IllustrisTNG show relatively little evolution, even after splitting the sample into satellites and centrals. The large discrepancy between the strong observed evolution and the weak evolution predicted by IllustrisTNG plus post-processing may be explained by either strong cosmic evolution in the properties of the dust grains or limitations in the model. In the latter case, the limitation may be connected to previous claims that the neutral gas content of galaxies does not evolve fast enough in IllustrisTNG

    Deep three-dimensional solid-state qubit arrays with long-lived spin coherence

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    Nitrogen-vacancy centers (NVCs) in diamond show promise for quantum computing, communication, and sensing. However, the best current method for entangling two NVCs requires that each one is in a separate cryostat, which is not scalable. We show that single NVCs can be laser written 6–15-µm deep inside of a diamond with spin coherence times that are an order of magnitude longer than previous laser-written NVCs and at least as long as naturally occurring NVCs. This depth is suitable for integration with solid immersion lenses or optical cavities and we present depth-dependent T2 measurements. 200 000 of these NVCs would fit into one diamond

    Mojave Applied Ecology Notes Spring 2011

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    Red brome distribution in the eastern Mojave Desert, A look at the UNLV xeric gardens and Marjorie Barrick museum, Summary of recent science synthesis effort

    Merleau-Ponty and neuroaesthetics: Two approaches to performance and technology

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    This is an Author's Accepted Manuscript of an article published in Digital Creativity, 23(3-4), 225 - 238, 2012. Copyright @ 2012 Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/14626268.2012.709941.Assisted by the rapid growth of digital technology, which has enhanced its ambitions, performance is an increasingly popular area of artistic practice. This article seeks to contextualise this within two methodologically divergent yet complimentary intellectual tendencies. The first is the work of the philosopher Merleau-Ponty, who recognised that our experience of the world has an inescapably ‘embodied’ quality, not reducible to mental accounts, which can be vicariously extended through specific instrumentation. The second is the developing field of neuroaesthetics; that is, neurological research directed towards the analysis, in brain-functional terms, of our experiences of objects and events which are culturally deemed to be of artistic significance. I will argue that both these contexts offer promising approaches to interpreting developments in contemporary performance, which has achieved critical recognition without much antecedent theoretical support
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