6,832 research outputs found

    THE COULTER PRINCIPLE: FOR THE GOOD OF HUMANKIND

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    The atomic bombings of Hiroshima and Nagasaki in August 1945 made Wallace H. Coulter abruptly comprehend the critical need for rapid and accurate blood-cell counts in providing care for victims of radiation exposure. This thesis documents the unwritten story of his journey from that comprehension through his invention and implementation of the Coulter Principle, its commercialization in the first widely available automated blood-cell counter, and elaboration of that ground-breaking counter into increasingly sophisticated instrumentation for analysis not only of blood cells, but of particles involved in many other scientific disciplines. International cold-war politics and the burgeoning of increasingly powerful nuclear weapons were important motivations for him throughout the period here considered; these are summarized as context for his developmental activities. The Coulter Principle states that if a suspension of blood cells is passed through a small restriction simultaneously with an electric current, the cells will modulate the current, so enabling them to be counted and sized. Today, hematology analyzers based on the Coulter Principle daily process blood samples from many more patients than the number of casualties from the Hiroshima and Nagasaki bombings. In closing, significant recognitions of Coulter’s contributions are summarized

    What Price for the Right to Go a-Droving? A Derived Demand Approach

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    Travelling stock reserves (TSRs) were established in Australia as a way of allowing the passage of livestock through settled lands to facilitate stocking of new lands. Subsequently, they remained important as a way of moving livestock from property to property or from property to market. Today, the area of land dedicated to TSRs in NSW is estimated at 2.3 million hectares, which are used more as a source of feed than as a livestock thoroughfare. The value of TSRs as a source of feed is particularly important during drought periods, and pricing of access for walking stock has become a subject of contention within the Rural Land Protection Boards (RLPB). The price of TSR permits for walking stock is considerably lower than for agistment, thereby compromising the capacity of the system to be self-funding. The objective of this study is to explore possible pricing arrangements using a derived demand approach. A representative linear programming model was developed for a farm in Nyngan, NSW. The model was used to obtain estimates of the demand elasticity for TSR services with respect to their own price, the price of supplementary feeds and the price of wool. The effect of drought on these elasticities was also explored.travelling stock reserves, derived demand, grazing, linear programming, Demand and Price Analysis, Livestock Production/Industries,

    A social-ecological systems framework for food systems research: accommodating transformation systems and their products

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    The social-ecological systems (SES) framework was developed to support communication across the multiple disciplines concerned with sustainable provision and/or appropriation of common-pool resources (CPRs). Transformation activities (e.g. processing, distribution, retailing) in which value is added to resource units appropriated from CPRs were assumed in developing the framework to be exogenous to the SES of focal concern. However, provision and appropriation of CPRs are nowadays often closely integrated with the market economy, so significant interdependence exists between many CPR provision/appropriation activities and the activities in which appropriated resource units are transformed into the products ultimately marketed. This paper presents a modified version of the SES framework designed to better account for transformation activities in order to be more suitable for diagnosing those sustainability problems where it is inappropriate to define all such activities as exogenous to the SES of focal concern. The need for such modification was identified in a research project examining the challenges faced by Cambodian cattle-owning smallholders in accessing value chains for premium-priced beef. Hence the immediate focus was on strengthening the SES framework’s value for facilitating a multi-disciplinary diagnostic approach to food system research projects of this kind. The modified SES framework’s potential in this respect was illustrated by a preliminary application that drew on literature reviewed for the Cambodian project. Significant further potential exists in using the modified framework as a foundation from which to develop a version that is suitable for application to SESs in which transformation systems are appropriately represented as endogenous. Maintaining consistency with the standard SES framework will enable communication to occur more effectively between food system researchers and CPR scholars more generally

    A q-methodology evaluation of visions of sustainable development

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    The concept of the “triple bottom line” has recently become central to sustainable development (SD) and it emerged to be internationally regarded as integrating economic, environmental and social considerations into planning for the future. While numerous authors have contended that successful delivery of SD required a consensus and shared vision about implementation, objectives, and outcomes, others have argued that the lack of consensus about SD is not necessarily problematical. Whether or not a consensus is required for the successful deployment of SD is debatable, but that pluralities of views about SD exist is now widely acknowledged. Involved In the contestation about SD are competing views regarding the human relationship to nature and the form that future development should take. A review of the relevant literature indicated that concepts of SD have been classified in various ways. For example, some writers have distinguished between ‘very strong’, \u27strong\u27, ‘weak’ and ‘very weak’ conditions required for sustainability. Other writers have devised alternative schema based on various answers to questions such as: what is to be sustained? What is to be developed? How? Why? Whilst such schema may provide useful frameworks, they do not necessarily provide empirical data on how SD is understood by persons responsible for developing and implementing policy at one or another level of government. In addressing that issue, this dissertation aimed to examine the beliefs about SD that were held by a group of 170 people associated with the implementation of SD at the level of local government and community in Western Australia. This examination was undertaken to establish if, and how, the views of these people in the community matched the propositions about SD that have previously been made by academics and other commentators. Local government provided a context for the study because of the Commonwealth of Australia’s endorsement of the United Nations Agenda 21 Program. With the endorsement of Agenda 21, local government was recognised by the Commonwealth and the UN as having a major role to play in SD promotion efforts. The issues outlined above led the dissertation to two purposes. The first purpose was to establish if SD was actually understood to have meaning within the context of previous propositions regarding a spectrum of views on sustainability. The second, and more important, purpose was to establish the characteristics of visions of SD as understood by a sample of people involved with local government decision-making in Perth, Western Australia. The objective was to discover whether a shared vision of SD based on a consensus of opinion was available, or whether a plurality of views would emerge corresponding to one or more of the previous classifications of very strong, strong, weak and very weak SD available In the related literature. To deliver those two outcomes, Q-Methodology was used to enable classification of the visions that people held about SD

    Tactical Opportunities, Risk Attitude and Choice of Farming Strategy: an Application of the Distribution Method

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    When assessing farming strategies, it is important to account for the opportunities provided for tactically adjusting to outcomes of risk. The hypothesis that accounting for tactical adjustment is more important than accounting for risk attitude was supported in this study with regard to identifying the optimal drainage recirculation strategy for an irrigated dairy farm. Failing to account for tactical adjustment would lead to a sub‐optimal choice, costing the farmer about A$3 100 in present value terms. In contrast, failing to account for risk aversion would not affect the strategy chosen. The distribution method was found to be well suited to modelling tactical adjustment.Research and Development/Tech Change/Emerging Technologies,

    Three-dimensional imaging of direct-written photonic structures

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    Third harmonic generation microscopy has been used to analyze the morphology of photonic structures created using the femtosecond laser direct-write technique. Three dimensional waveguide arrays and waveguide-Bragg gratings written in fused-silica and doped phosphate glass were investigated. A sensorless adaptive optical system was used to correct the optical aberrations occurring in the sample and microscope system, which had a lateral resolution of less than 500 nm. This non-destructive testing method creates volume reconstructions of photonic devices and reveals details invisible to other linear microscopy and index profilometry techniques.Comment: 8 pages, 3 color figures, 2 hyper-linked animation
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