295 research outputs found

    Combining Biophysical and Price Simulations to Assess the Economics of Long-Term Crop Rotations

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    Biophysical simulation models (e.g. APSIM) using historical rainfall data are increasingly being used to provide yield and other data on crop rotations in various regions of Australia. However, to analyse the economics of these rotations it is desirable to incorporate the other main driver of profitability, price variation. Because the context was that APSIM was being used to simulate an existing trial site being monitored by a farmer group Gross Margin output was considered most appropriate. Long-run rotational gross margins were calculated for the various rotations with yields (and other physical outputs) derived from APSIM simulations over a period of 100+ years and prices simulated in @Risk based on subjective triangular price distributions elicited from farmers in the group. Rotations included chickpeas, cotton, lucerne, sorghum, wheat and different lengths of fallow. Output presented to the farmers included mean annual gross margins and distributions of gross margins presented as probability distributions, cumulative probability distributions and box and whisker plots. Cotton rotations were the most profitable but had greater declines in soil fertility and greater drainage out of the root zone.Crop Production/Industries,

    Combining biophysical and price simulations to assess the economics of long-term crop rotations

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    Long-run rotational gross margins were calculated with yields derived from biophysical simulations in APSIM over a period of 100+ years and prices simulated in @Risk based on subjective triangular price distributions elicited from the Jimbour Plains farmer group. Rotations included chickpeas, cotton, lucerne, sorghum, wheat and different lengths of fallow. Output presented to the farmers included mean annual GMs and distributions of GMs with box and whisker plots found to be suitable. Mean-standard deviation and first and second-degree stochastic dominance efficiency measures were also calculated. Including lucerne in the rotations improved some sustainability indicators but reduced profitability.Crop Production/Industries, Farm Management,

    The medical schools outcomes database project: Australian medical student characteristics

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    BACKGROUND Global medical workforce requirements highlight the need for effective workforce planning, with the overall aims being to alleviate doctor shortages and prevent maldistribution. The Medical Schools Outcomes Database and Longitudinal Tracking (MSOD) Project provides a foundation for evaluating outcomes of medical education programs against specified workforce objectives (including rural and areas of workforce needs), assisting in medical workforce planning, and provision of a national research resource. This paper describes the methodology and baseline results for the MSOD project. METHODS The MSOD Project is a prospective longitudinal multiple-cohort study. The project invites all commencing and completing Australian medical students to complete short questionnaires. Participants are then asked to participate in four follow-up surveys at 1, 3, 5 and 8 years after graduation. RESULTS Since 2005, 30,635 responses for medical students (22,126 commencing students and 8,509 completing students) in Australia have been collected. To date, overall eligible cohort response rates are 91% for commencing students, and 83% for completing students. Eighty three percent of completing medical student respondents had also completed a commencing questionnaire. Approximately 80% of medical students at Australian medical schools are Australian citizens. Australian medical schools have only small proportions of Indigenous students. One third of medical students speak a language other than English at home.The top three vocational choices for commencing medical students were surgery, paediatrics and child health and general practice. The top three vocational choices for completing students were surgery, adult medicine/ physician, and general practice. Overall, 75.7% of medical students changed their first career preference from commencement to exit from medical school. Most commencing and completing medical students wish to have their future medical practice in capital cities or in major urban centers. Only 8.1% of commencing students and 4.6% of completing students stated an intention to have their future medical practice in smaller towns and small communities. CONCLUSIONS The MSOD longitudinal project is now an established national resource that is beginning to generate significant research outputs, along with providing key information for workforce planning and policy makers. The project has now expanded to enrol New Zealand medical students.Baldeep Kaur, Angela Carberry, Nathaniel Hogan, Don Roberton and Justin Beilb

    Non-spherical optically trapped probes: Design, control, and applications

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    In this proceedings paper we show describe how a microtool can be assembled, and tracked in three dimensions such that its full rotational and translational coordinates, q, are recovered. This allows tracking of the motion of any arbitrary point, d, on the microtool's surface. When the micro-tool is held using multiple optical traps the motion of such a point investigates the inside of an ellipsoidal volume - we term this a 'thermal ellipsoid. We demonstrate how the shape of this thermal ellipsoid may be controlled by varying the relative trapping power of the optical traps, and adjusting the angle at which the micro-tool is held relative to the focal plane. Our experimental results follow the trends derived by Simpson and Hanna

    Employee Stock Ownership and Financial Performance in European Countries: The Moderating Effects of Uncertainty Avoidance and Social Trust

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    This study investigates how the effect of employee stock ownership on financial performance may hinge on the diverse cultural and societal contexts of European countries. Based on agency and national culture theories, we hypothesize that the positive relationship between employee stock ownership and return on assets (ROA) is stronger in those nations with lower uncertainty avoidance and higher social trust. Using a multisource, time‐lagged, large‐scale dataset of 1,741 firms from 21 countries in Europe, our multilevel, random coefficient modeling analysis found evidence for these hypotheses, suggesting that uncertainty avoidance and social trust serve as important contextual cues in predicting the linkage between employee stock ownership and financial performance. Our supplemental analysis with distinction between the managerial and nonmanagerial employee stock ownership further indicates managerial employee stock ownership has a direct positive effect on ROA. Although nonmanagerial employee stock ownership had a nonsignificant association with ROA, the relationship was positive and significant when uncertainty avoidance was low and social trust was high. This research contributes to the existing literature by illuminating some of the contextual influences altering the effectiveness of employee stock ownership. Our findings also offer practical suggestions for effectively using employee stock ownership

    An optically actuated surface scanning probe

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    We demonstrate the use of an extended, optically trapped probe that is capable of imaging surface topography with nanometre precision, whilst applying ultra-low, femto-Newton sized forces. This degree of precision and sensitivity is acquired through three distinct strategies. First, the probe itself is shaped in such a way as to soften the trap along the sensing axis and stiffen it in transverse directions. Next, these characteristics are enhanced by selectively position clamping independent motions of the probe. Finally, force clamping is used to refine the surface contact response. Detailed analyses are presented for each of these mechanisms. To test our sensor, we scan it laterally over a calibration sample consisting of a series of graduated steps, and demonstrate a height resolution of ∼ 11 nm. Using equipartition theory, we estimate that an average force of only ∼ 140 fN is exerted on the sample during the scan, making this technique ideal for the investigation of delicate biological samples

    Role of modelling in improving nutrient efficiency in cropping systems

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    The applicability of models in addressing resource management issues in agriculture has been widely promoted by the research community, yet examples of real impacts of such modelling efforts on current farming practices are rare. Nevertheless, simulation models can compliment traditional field experimentation in researching alternative management options. The first objective of this paper is, therefore, to provide four case study examples of where models were used to help research issues relating to improved nutrient efficiency in low-input cropping systems. The first two cases addressed strategies of augmenting traditional farming practices with small applications of chemical fertilizer (N and P). The latter two cases explicitly addressed the question of what plant genetic traits can be beneficial in low-nutrient farming systems. In each of these case studies, the APSIM (Agricultural Production Systems Simulator) systems model was used to simulate the impacts of alternative crop management systems. The question of whether simulation models can assist the research community in contributing to purposeful change in farming practice is also addressed. Recent experiences in Australia are reported where simulation models have contributed to practice change by farmers. Finally, current initiatives aimed at testing whether models can also contribute to improving the nutrient efficiency of smallholder farmers in the SAT are discussed

    Governing through representatives of the community: A case study on farmer organizations in rural Australia

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    The concept ‘governing through the community’ has been used frequently to interpret the neoliberal policy embraced by Australian governments since the 1990s. Yet explanation is still inadequate of how ‘governing through the community’ is conducted in practice, particularly the specific mechanisms that regulate interaction among government agencies, groups seeking to represent the community and individuals in the community. In this study, we find that ‘governing through the community’ is actually ‘governing through representatives of the community’ because it is the representatives that make the community visible and governable. This observation is based on a case study of three kinds of farmer organizations, in two states of Australia, who see their role as serving the community and are regarded by outsiders as representatives of the community at least on certain issues. An understanding of the interaction among different stakeholders within and outside of the community is developed through three themes of ‘paperwork’, ‘data’ and ‘price’ that were used by locals from Landcare groups, grower groups and farmer cooperatives, respectively, to articulate how they experience the mechanisms through which their interactions are regulated. This paper concludes that these groups can claim to represent some residents within a defined geographical area, rather than any exact definition of ‘the community’ and that this is a sufficient claim to enable these groups to participate in the process of ‘governing through the community’. The tensions between government agencies, community representatives and community members threaten the legitimacy of the community representatives as intermediaries. Government agencies do try to contribute to reduce these tensions by strengthening the legitimacy of community representatives through various policy and project mechanisms. However, while the stated aim of ‘governing through the community’ is often focused on producing a ‘flourishing rural community’ through improving democratic modes of representation, this study demonstrates that it is only part of the community, namely the ‘targeted customers’ of the farmer organizations, that is potentially reachable to ‘the state’

    Shape-induced force fields in optical trapping

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    Advances in optical tweezers, coupled with the proliferation of two-photon polymerization systems, mean that it is now becoming routine to fabricate and trap non-spherical particles. The shaping of both light beams and particles allows fine control over the flow of momentum from the optical to mechanical regimes. However, understanding and predicting the behaviour of such systems is highly complex in comparison with the traditional optically trapped microsphere. In this Article, we present a conceptually new and simple approach based on the nature of the optical force density. We illustrate the method through the design and fabrication of a shaped particle capable of acting as a passive force clamp, and we demonstrate its use as an optically trapped probe for imaging surface topography. Further applications of the design rules highlighted here may lead to new sensors for probing biomolecule mechanics, as well as to the development of optically actuated micromachines
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