9,119 research outputs found

    Australian Consumers' Concerns and Preferences for Food Policy Alternatives

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    Results from a 2007 Australian consumer survey conducted at a large farmers market are used to explore the hypothesis that consumers who are more concerned about certain types of food labeling information, particularly information related to food production attributes, are more likely to support policies which help develop farmers markets and support mandatory labeling policies. Product information and attributes such as Country-of-Origin, No Growth Hormones Used, Free Range and Animals Treated Humanely and Environmentally-friendly appear to be very important to consumers. It appears that respondents want increased government involvement in developing consistent food labelling standards for these attributes and support mandatory food labelling policies, however, respondents are split between whether third-parties or the Australian government should oversee regulation of the program. Some respondents appear to view a mandatory labelling policy as a method to improve competitiveness and sustainability of small food producers who want to use labelling to differentiate themselves. Respondents also tended to support the government subsidizing the development of farmers markets. Respondents viewed FM as an opportunity to gain additional information or purchase foods that have credence attributes such as pesticide-free. Thus, policies supporting FM may help alleviate market failures related to asymmetric information and lack of choice.market failure, consumers, farmers markets, labelling, Agricultural and Food Policy,

    The formation of galaxy disks in a hierarchical universe

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    The formation of galactic discs and the efficiency of star formation within them are issues central to our understanding of galaxy formation. We have developed a detailed and versatile model of disc formation which combines the strengths of previous studies of isolated discs with those of hierarchical galaxy formation models. Disc structure is inferred from the distribution of angular momentum in hot halo gas and the hierarchical build-up of dark matter, leading to theoretically generated systems where the evolution of surface density, rotation, velocity dispersion, stability and metallicity is predicted for annular regions of width 20-100 pc. The model will be used to establish whether the accepted theory of large-scale structure formation in the universe is consistent with observed trends in the properties of disc galaxies. This first paper explicitly examines the importance of embedding such calculations within a merging hierarchy of dark matter haloes, finding that this leads to dramatically different formation histories compared to models in which discs grow in isolation. Different models of star formation are explored, and are found to have only a secondary influence on the properties of the resulting galaxy discs, the main governing factor being the infalling gas supply from the hot halo.Comment: 13 pages, 9 figures, accepted by MNRA

    Galaxy size trends as a consequence of cosmology

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    We show that recently documented trends in galaxy sizes with mass and redshift can be understood in terms of the influence of underlying cosmic evolution; a holistic view which is complimentary to interpretations involving the accumulation of discreet evolutionary processes acting on individual objects. Using standard cosmology theory, supported with results from the Millennium simulations, we derive expected size trends for collapsed cosmic structures, emphasising the important distinction between these trends and the assembly paths of individual regions. We then argue that the observed variation in the stellar mass content of these structures can be understood to first order in terms of natural limitations of cooling and feedback. But whilst these relative masses vary by orders of magnitude, galaxy and host radii have been found to correlate linearly. We explain how these two aspects will lead to galaxy sizes that closely follow observed trends and their evolution, comparing directly with the COSMOS and SDSS surveys. Thus we conclude that the observed minimum radius for galaxies, the evolving trend in size as a function of mass for intermediate systems, and the observed increase in the sizes of massive galaxies, may all be considered an emergent consequence of the cosmic expansion.Comment: 14 pages, 13 figures. Accepted by MNRA

    Climate change adaptation planning and cross-sectoral policy coherence in southern Africa

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    The post-2015 development agenda requires policy coherence, where achievement of development goals in one sector does not undermine the achievement of the goals of another. It also recognises that cross-cutting issues like adaptation to climate change need to be mainstreamed across multiple sectors. This paper presents a policy analysis using the cases of Malawi, Tanzania and Zambia. It analyses the water management and agricultural strategies and approaches identified in a variety of policies and plans. These include national sector policies for water and agriculture, National Development Plans, and climate change policies and strategies, including National Adaptation Programmes of Action and the Intended Nationally Determined Contributions submitted prior to the 2015 United Nations Framework Convention on Climate Change Conference of the Parties. It assesses the extent to which policies are coherent with one another with regard to their treatment of climate change adaptation using Qualitative Document Analysis. Findings identify that sector policies show some degree of cross-thematic coherence, in particular around their acknowledgement of the importance to address disaster management of floods and droughts. However, policy statements are typified by a relative lack of recognition of the need to develop supporting instruments and strategies that address climate adaptation needs over longer timeframes. Climate change policies explicitly call for significant investment in adaptation from the international community. Where coherence between sector and climate policies and strategies is strongest, the more recent climate policies largely repackage existing sectoral policy statements. These findings can be understood in the context of the uncertainty of climate change impacts for the longer term (for which a wider variety of adaptations are identified), alongside more event-driven disaster management planning where the impacts are more immediate and obviously evident. This prioritisation is also linked to development needs and the short-term nature of political cycles and economic gain. For climate-resilient policy decision-making to make further headway, we argue that governments need to embrace cross-sectoral planning more pro- actively in order to foster greater policy coherence and to deliver more climate resilient agriculture and water management

    Analytic and numerical realisations of a disk galaxy

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    Recent focus on the importance of cold, unshocked gas accretion in galaxy formation -- not explicitly included in semi-analytic studies -- motivates the following detailed comparison between two inherently different modelling techniques: direct hydrodynamical simulation and semi-analytic modelling. By analysing the physical assumptions built into the Gasoline simulation, formulae for the emergent behaviour are derived which allow immediate and accurate translation of these assumptions to the Galform semi-analytic model. The simulated halo merger history is then extracted and evolved using these equivalent equations, predicting a strikingly similar galactic system. This exercise demonstrates that it is the initial conditions and physical assumptions which are responsible for the predicted evolution, not the choice of modelling technique. On this level playing field, a previously published Galform model is applied (including additional physics such as chemical enrichment and feedback from active galactic nuclei) which leads to starkly different predictions.Comment: 15 pages, 15 figure

    Suite2p: beyond 10,000 neurons with standard two-photon microscopy

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    Two-photon microscopy of calcium-dependent sensors has enabled unprecedented recordings from vast populations of neurons. While the sensors and microscopes have matured over several generations of development, computational methods to process the resulting movies remain inefficient and can give results that are hard to interpret. Here we introduce Suite2p: a fast, accurate and complete pipeline that registers raw movies, detects active cells, extracts their calcium traces and infers their spike times. Suite2p runs on standard workstations, operates faster than real time, and recovers ~2 times more cells than the previous state-of-the-art method. Its low computational load allows routine detection of ~10,000 cells simultaneously with standard two-photon resonant-scanning microscopes. Recordings at this scale promise to reveal the fine structure of activity in large populations of neurons or large populations of subcellular structures such as synaptic boutons
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