762 research outputs found

    Struggling to a monumental triumph : Re-assessing the final stages of the smallpox eradication program in India, 1960-1980

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    The global smallpox program is generally presented as the brainchild of a handful of actors from the WHO headquarters in Geneva and at the agency's regional offices. This article attempts to present a more complex description of the drive to eradicate smallpox. Based on the example of India, a major focus of the campaign, it is argued that historians and public health officials should recognize the varying roles played by a much wider range of participants. Highlighting the significance of both Indian and international field officials, the author shows how bureaucrats and politicians at different levels of administration and society managed to strengthen—yet sometimes weaken—important program components. Centrally dictated strategies developed at WHO offices in Geneva and New Delhi, often in association with Indian federal authorities, were reinterpreted by many actors and sometimes changed beyond recognition

    Multifaceted contributions : health workers and smallpox eradication in India

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    Smallpox eradication in South Asia was a result of the efforts of many grades of health-workers. Working from within the confines of international organisations and government structures, the role of the field officials, who were of various nationalities and also drawn from the cities and rural enclaves of the countries in these regions, was crucial to the development and deployment of policies. However, the role of these personnel is often downplayed in official histories and academic histories, which highlight instead the roles played by a handful of senior officials within the World Health Organization and the federal governments in the sub-continent. This article attempts to provide a more rounded assessment of the complex situation in the field. In this regard, an effort is made to underline the great usefulness of the operational flexibility displayed by field officers, wherein lessons learnt in the field were made an integral part of deploying local campaigns; careful engagement with the communities being targeted, as well as the employment of short term workers from amongst them, was an important feature of this work

    First Experimental Demonstration of Full-Duplex Optical Communications on a Single Laser Beam

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    We present the results of the first experimental demonstration a novel communications architecture that will be deployed on a Space Shuttle mission in 2003. This architecture can provide a very lightweight, low power consumption, low data rate communications link between the earth and LEO satellites. A unique characteristic of this system is that it provides full-duplex communications on a single beam is presented. The results of first experiments demonstrating this full duplex communications architecture are presented

    Magnetothermal conductivity of Ba1-xKxBiO3 crystals

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    We have investigated the thermal conductivity of single-crystal Ba1-xKxBiO3 (BKBO). The measured temperature and field dependences reveal that both electrons and phonons contribute to the thermal conduction of BKBO in both the normal and the superconducting states, and that the phonon mean free path can be manipulated by potassium doping concentration. The potassium-underdoped samples exhibit a suppression of phonon diffusivity, and consequently a more pronounced electronic contribution, indicating that the statistical fluctuation of potassium concentration may lead to an increase of defect density. The field-dependent thermal conductivity of BKBO in the superconducting state exhibits scaling behavior, which indicates the presence of an unconventional superconducting gap

    Lightweight Optical Wavelength Communications without a Laser in Space

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    We will present a model for an earth-to-low-earthorbit optical communications system. The system modeled herein is designed to offer a very lightweight, low power consumption, low data rate communications link from LEO satellites. A novel architecture for a free-space optical communications link is presented and analyzed. For the first time, a method that offers full-duplex communications on a single beam is presented. In addition, a novel data format for free-space optical communications is presented. In this system, both the laser and the downlink receiver are located on the ground. The optical elements located on the spacecraft are a simple uplink receiver and a retromodulator. In fact, the laser transmitter for the system is a semiconductor device. We will present a simple feasibility model for the LOWCAL experiment that provides an estimate of the performance capability and identifies major system tradeoffs. Assuming a laser transmitter power of - 7-dB and a communications data rate of 10-kbps, we expect link margins of 17 dB for the downlink. For the uplink, an SC-FSK format is proposed that is invisible to the downlink and provides a link margin of 20 dB

    Growing Environmental Activists: Developing Environmental Agency and Engagement Through Children’s Fiction.

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    We explore how story has the potential to encourage environmental engagement and a sense of agency provided that critical discussion takes place. We illuminate this with reference to the philosophies of John Macmurray on personal agency and social relations; of John Dewey on the primacy of experience for philosophy; and of Paul Ricoeur on hermeneutics, dialogue, dialectics and narrative. We view the use of fiction for environmental understanding as hermeneutic, a form of conceptualising place which interprets experience and perception. The four writers for young people discussed are Ernest Thompson Seton, Kenneth Grahame, Michelle Paver and Philip Pullman. We develop the concept of critical dialogue, and link this to Crick's demand for active democratic citizenship. We illustrate the educational potential for environmental discussions based on literature leading to deeper understanding of place and environment, encouraging the belief in young people that they can be and become agents for change. We develop from Zimbardo the key concept of heroic resister to encourage young people to overcome peer pressure. We conclude with a call to develop a greater awareness of the potential of fiction for learning, and for writers to produce more focused stories engaging with environmental responsibility and activism

    Decision by sampling

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    We present a theory of decision by sampling (DbS) in which, in contrast with traditional models, there are no underlying psychoeconomic scales. Instead, we assume that an attribute’s subjective value is constructed from a series of binary, ordinal comparisons to a sample of attribute values drawn from memory and is its rank within the sample. We assume that the sample reflects both the immediate distribution of attribute values from the current decision’s context and also the background, real-world distribution of attribute values. DbS accounts for concave utility functions; losses looming larger than gains; hyperbolic temporal discounting; and the overestimation of small probabilities and the underestimation of large probabilities

    Ab initio atomistic thermodynamics and statistical mechanics of surface properties and functions

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    Previous and present "academic" research aiming at atomic scale understanding is mainly concerned with the study of individual molecular processes possibly underlying materials science applications. Appealing properties of an individual process are then frequently discussed in terms of their direct importance for the envisioned material function, or reciprocally, the function of materials is somehow believed to be understandable by essentially one prominent elementary process only. What is often overlooked in this approach is that in macroscopic systems of technological relevance typically a large number of distinct atomic scale processes take place. Which of them are decisive for observable system properties and functions is then not only determined by the detailed individual properties of each process alone, but in many, if not most cases also the interplay of all processes, i.e. how they act together, plays a crucial role. For a "predictive materials science modeling with microscopic understanding", a description that treats the statistical interplay of a large number of microscopically well-described elementary processes must therefore be applied. Modern electronic structure theory methods such as DFT have become a standard tool for the accurate description of individual molecular processes. Here, we discuss the present status of emerging methodologies which attempt to achieve a (hopefully seamless) match of DFT with concepts from statistical mechanics or thermodynamics, in order to also address the interplay of the various molecular processes. The new quality of, and the novel insights that can be gained by, such techniques is illustrated by how they allow the description of crystal surfaces in contact with realistic gas-phase environments.Comment: 24 pages including 17 figures, related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

    Optimal Cross-Wind Towing and Power Generation with Tethered Kites

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    Non-powered flight vehicles such as kites can provide a means of transmitting wind energy from higher altitudes to the ground via tethers. Although there have been many proposals for systems to extract wind energy from higher altitudes, this paper focuses on the use of a light lifting body at the end of a tether to generate useful power. Two major configurations are studied: 1) the kite is used to tow a ground vehicle in the cross-wind direction, 2) the kite is flown to generate power using a ground generator. In both cases, the useful work done by the kite is transmitted to the ground through the tether. Both applications require automatic control of the kite. A simplified system model is used to study the nature of the optimal trajectories of the system for different wind speeds. Numerical results illustrate that optimal power generation requires complex three-dimensional kite trajectories, whereas cross-wind towing requires much simpler trajectories. A feedback tracking controller is demonstrated for tracking the kite trajectories in the presence of unsteady winds

    The Theory/Applications Balance in Management Pedagogy: Where Do We Stand?

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    Business schools are expected to be "professional" in the sense that their mission is primarily to prepare people to practice their skills in the business world. Various critics, however, claim that management professors overemphasize theory and research and neglect the practice and applications students need to transfer classroom theory to the world of practice. This study compared an earlier sample with a more recent sample of Academy of Management members concerning the relative emphasis they believed should be placed on theory and applications in management pedagogy and the techniques they used to bring applications into the classroom. Current respondents believed that more emphasis should be placed on applications than the earlier respondents. An unexpected finding, however, was that the more recent respondents reported a lower mean usage of pedagogical techniques that are appropriate for developing students' ability to apply course concepts than the previous group. Possible reasons for these incongruent findings are discussed as well as the implications for management pedagogy.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
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