6,762 research outputs found

    Australian Organic Market Report 2008

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    Being four years since the publication of a similar research document, the Australian Organic Market Report (AOMR) 2008 is a landmark report for the organic industry. The report will be invaluable for monitoring and planning the industry development during a period of high growth. Delivering consistent data for benchmarking growth across the various sectors of the industry, it will be a key tool for decision making by organic producers and marketers, along with interested parties such as government and media, in assisting in understanding the nature, size and development of the organic industry in Australia. Supply chain development has been hindered over many years by a lack of basic information about volumes, seasonality, continuity and quality, not only making it difficult for potentially new members of industry to feel confident about investing in organic, however also likely to cause overseas buyers to look for other countries with more comprehensive industry information. The report is an important base research document required by any growing industry. It has been commissioned by Biological Farmers of Australia (BFA), and has been carried out independently by the University of New England’s Organic Research Group. The report has the financial support of major sponsor Westpac Bank, all State Governments in Australia as well as many dedicated industry businesses

    Australian Organic Market Report 2010

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    This is the second report the Biological Farmers of Australia has commissioned to help industry bench mark the growth and health of its sectors. This report - another significant milestone in the two decade plus history of the rapidly developing Australian certified organic sector - builds the information base for industry to benchmark production and market value against past and current claims and estimates and will enable monitoring of future growth of the certified organic market in Australia and its farming and production base. In an industry characterised by operational diversity, this report allows for performance assessment by sector. The next publication in this series is planned in 2012 (biennial since the inaugural report in 2008) as a means of providing the wider industry with invaluable and realistic market information

    Complex pattern formation in reaction diffusion systems with spatially-varying parameters

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    Spontaneous pattern formation in reaction–diffusion systems on a spatially homogeneous domain has been well studied. However, in embryonic development and elsewhere, pattern formation often takes place on a spatially heterogeneous background. We explore the effects of spatially varying parameters on pattern formation in one and two dimensions using the Gierer–Meinhardt reaction–diffusion model. We investigate the effect of the wavelength of a pre-pattern and demonstrate a novel form of moving pattern. We find that spatially heterogeneous parameters can both increase the range and complexity of possible patterns and enhance the robustness of pattern selection

    Speed of reaction diffusion in embryogenesis

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    Reaction diffusion systems have been proposed as mechanisms for patterning during many stages of embryonic development. While much attention has been focused on the study of the steady state patterns formed and the robustness of pattern selection, much less is known about the time scales required for pattern formation. Studies of gradient formation by the diffusion of a single morphogen from a localized source have shown that patterning can occur on realistic time scales over distances of a millimeter or less. Reaction diffusion has the potential to give rise to patterns on a faster time scale, since all points in the domain can act as sources of morphogen. However, the speed at which patterning can occur has hitherto not been explored in depth. In this paper, we investigate this issue in specific reaction diffusion models and address the question of whether patterning via reaction diffusion is fast enough to be applicable to morphogenesis

    How skin color matters for the physical and mental health of African Americans

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    Research in recent decades has found that African Americans have worse health outcomes compared to white Americans. In new research Ellis P. Monk, Jr. investigates this disparity. Using a unique dataset to examine intra-racial skin color discrimination, he finds that the more discrimination African Americans felt from other African Americans and non-blacks, the worse their physical and mental health was. With this in mind, he argues that in not capturing skin color, current census ‘race’ categories make it harder to understand how social inequalities are reproduced through discrimination

    The electrical breakdown of gases by pulsed oscillatory fields

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    Two dimensional eye tracking: Sampling rate of forcing function

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    A study was conducted to determine the minimum update rate of a forcing function display required for the operator to approximate the tracking performance obtained on a continuous display. In this study, frequency analysis was used to determine whether there was an associated change in the transfer function characteristics of the operator. It was expected that as the forcing function display update rate was reduced, from 120 to 15 samples per second, the operator's response to the high frequency components of the forcing function would show a decrease in gain, an increase in phase lag, and a decrease in coherence

    Head tracking at large angles from the straight ahead position

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    One of the big advantages of a helmet sight in a high performance aircraft is its off-boresight capability in aiming a fire control system. However, tracking data using a target that is moving rapidly and randomly for an extended period of time is missing. This study is intended to provide data in this area that will be of value to engineers in designing head control systems

    Pattern formation by lateral inhibition with feedback: a mathematical model of Delta-Notch intercellular signalling

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    In many developing tissues, adjacent cells diverge in character so as to create a fine-grained pattern of cells in contrasting states of differentiation. It has been proposed that such patterns can be generated through lateral inhibition—a type cells–cell interaction whereby a cell that adopts a particular fate inhibits its immediate neighbours from doing likewise. Lateral inhibition is well documented in flies, worms and vertebrates. In all of these organisms, the transmembrane proteins Notch and Delta (or their homologues) have been identified as mediators of the interaction—Notch as receptor, Delta as its ligand on adjacent cells. However, it is not clear under precisely what conditions the Delta-Notch mechanism of lateral inhibition can generate the observed types of pattern, or indeed whether this mechanism is capable of generating such patterns by itself. Here we construct and analyse a simple and general mathematical model of such contact-mediated lateral inhibition. In accordance with experimental data, the model postulates that receipt of inhibition (i.e. activation of Notch) diminishes the ability to deliver inhibition (i.e. to produce active Delta). This gives rise to a feedback loop that can amplify differences between adjacent cells. We investigate the pattern-forming potential and temporal behavior of this model both analytically and through numerical simulation. Inhomogeneities are self-amplifying and develop without need of any other machinery, provided the feedback is sufficiently strong. For a wide range of initial and boundary conditions, the model generates fine-grained patterns similar to those observed in living systems
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