522 research outputs found

    Sheep and wool industries need to improve their performance

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    Today in Western Australia, sheep are run at slightly higher stocking rates, are achieving greater lambing percentages (up JO per cent) and higher wool cuts per animal ( up 0. 6 kg greasy) than in the 1960s. When all components of production are considered, the productivity of sheep fanns has increased by 2. 7 per cent per year over the past 35 years. The challenge of the next decade is to achieve substantially greater rates of improvement than for past years if the sheep and wool industries are to maintain their significant place in Western Australian agriculture

    Virtual Screening for Experimentalists _ a Xgrid-Powered Web Server

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    The impact of electronic monitoring on fleet wide discarding of small cod in Scottish demersal fisheries

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    Acknowledgments The authors of this paper would like to acknowledge the fishers, fisheries inspectors, and video reviewers who participated in or supported the Scottish cod catch quota management scheme. Additionally, we thank two anonymous reviewers for their encouraging and insightful comments and suggestions.Peer reviewedPublisher PD

    Accountability Work: Examining the Values, Technologies and Work Practices that Facilitate Transparency in Charities

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    Charities are subject to stringent transparency and accountability requirements from government and funders to ensure that they are conducting work and spending money appropriately. Charities are increasingly important to civic life and have unique characteristics as organisations. This provides a rich space in which HCI researchers may learn from and affect both held notions of transparency and accountability, and the relationships between these organisations and their stakeholders. We conducted ethnographic fieldwork and workshops over a seven month period at a charity. We aimed to understand how the transparency obligations of a charity manifest through work and how the workers of a charity reason about transparency and accountability as an everyday practice. Our findings highlight how organisations engage in presenting different accounts of their work; how workers view their legal transparency obligations in contrast with their accountability to their everyday community; and how their labour does not translate well to outcome measures or metrics. We discuss implications for the design of future systems that support organisations to produce accounts of their work as part of everyday practice

    A simulation approach to assessing environmental risk of sound exposure to marine mammals

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    Intense underwater sounds caused by military sonar, seismic surveys, and pile driving can harm acoustically sensitive marine mammals. Many jurisdictions require such activities to undergo marine mammal impact assessments to guide mitigation. However, the ability to assess impacts in a rigorous, quantitative way is hindered by large knowledge gaps concerning hearing ability, sensitivity, and behavioral responses to noise exposure. We describe a simulation-based framework, called SAFESIMM (Statistical Algorithms For Estimating the Sonar Influence on Marine Megafauna), that can be used to calculate the numbers of agents (animals) likely to be affected by intense underwater sounds. We illustrate the simulation framework using two species that are likely to be affected by marine renewable energy developments in UK waters: gray seal (Halichoerus grypus) and harbor porpoise (Phocoena phocoena). We investigate three sources of uncertainty: How sound energy is perceived by agents with differing hearing abilities; how agents move in response to noise (i.e., the strength and directionality of their evasive movements); and the way in which these responses may interact with longer term constraints on agent movement. The estimate of received sound exposure level (SEL) is influenced most strongly by the weighting function used to account for the specie's presumed hearing ability. Strongly directional movement away from the sound source can cause modest reductions (~5 dB) in SEL over the short term (periods of less than 10 days). Beyond 10 days, the way in which agents respond to noise exposure has little or no effect on SEL, unless their movements are constrained by natural boundaries. Most experimental studies of noise impacts have been short-term. However, data are needed on long-term effects because uncertainty about predicted SELs accumulates over time. Synthesis and applications. Simulation frameworks offer a powerful way to explore, understand, and estimate effects of cumulative sound exposure on marine mammals and to quantify associated levels of uncertainty. However, they can often require subjective decisions that have important consequences for management recommendations, and the basis for these decisions must be clearly described.Publisher PDFPeer reviewe

    Towards a dynamics-based estimate of the extent of HR 8799’s unresolved warm debris belt

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    In many ways, the HR 8799 planetary system resembles our Solar system more closely than any other discovered to date – albeit significantly younger, and on a larger and more dramatic scale. The system features four giant planets and two debris belts. The first of these belts lies beyond the orbit of the outermost planet, and mirrors the location of our Solar system’s Edgeworth-Kuiper belt. The second, which has yet to be fully observationally characterised, lies interior to the orbit of the innermost known planet, HR8799 e, and is an analogue to our Asteroid Belt. With such a similar architecture, the system is a valuable laboratory for examining exoplanetary dynamics, and the interaction between debris disks and giant planets. In recent years, significant progress has been made in the characterisation of the outer of HR8799’s debris disks, primarily using the Herschel Space Observatory. In contrast, the inner disk, which lies too close to its host star to be spatially resolved by that instrument, remains poorly understood. This, in turn, leaves significant questions over both the location of the planetesimals responsible for producing the observed dust, and the physical properties of those grains. We have performed the most extensive simulations to date of the inner, unresolved debris belt around HR 8799, using UNSW Australia's supercomputing facility, Katana. In this work, we present the results of integrations following the evolution of a belt of dynamically hot debris interior to the innermost planet, HR8799 e, for a period of 60 million years, using an initial population of 500,000 massless test particles. These simulations have enabled the characterisation of the extent and structure of the inner belt, revealing that its outer edge must lie interior to the 3:1 mean-motion resonance with HR8799 e, at approximately 7.5 au, and highlighting the presence of fine structure analogous to the Solar system’s Kirkwood gaps. In the future, our results will also allow us to calculate a first estimate of the small-body impact rate and water delivery prospects for any potential terrestrial planet(s) that might lurk, undetected, in the inner system
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