5,581 research outputs found
THE COULTER PRINCIPLE: FOR THE GOOD OF HUMANKIND
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
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
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
Tactical Opportunities, Risk Attitude and Choice of Farming Strategy: an Application of the Distribution Method
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
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
PyPhi: A toolbox for integrated information theory
Integrated information theory provides a mathematical framework to fully
characterize the cause-effect structure of a physical system. Here, we
introduce PyPhi, a Python software package that implements this framework for
causal analysis and unfolds the full cause-effect structure of discrete
dynamical systems of binary elements. The software allows users to easily study
these structures, serves as an up-to-date reference implementation of the
formalisms of integrated information theory, and has been applied in research
on complexity, emergence, and certain biological questions. We first provide an
overview of the main algorithm and demonstrate PyPhi's functionality in the
course of analyzing an example system, and then describe details of the
algorithm's design and implementation.
PyPhi can be installed with Python's package manager via the command 'pip
install pyphi' on Linux and macOS systems equipped with Python 3.4 or higher.
PyPhi is open-source and licensed under the GPLv3; the source code is hosted on
GitHub at https://github.com/wmayner/pyphi . Comprehensive and
continually-updated documentation is available at https://pyphi.readthedocs.io/
. The pyphi-users mailing list can be joined at
https://groups.google.com/forum/#!forum/pyphi-users . A web-based graphical
interface to the software is available at
http://integratedinformationtheory.org/calculate.html .Comment: 22 pages, 4 figures, 6 pages of appendices. Supporting information
"S1 Calculating Phi" can be found in the ancillary file
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