131 research outputs found

    Fatty-Acid Preference Changes during Development in Drosophila melanogaster

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    Fatty-acids (FAs) are required in the diet of many animals throughout their life. However, the mechanisms involved in the perception of and preferences for dietary saturated and unsaturated FAs (SFAs and UFAs, respectively) remain poorly explored, especially in insects. Using the model species Drosophila melanogaster, we measured the responses of wild-type larvae and adults to pure SFAs (14, 16, and 18 carbons) and UFAs (C18 with 1, 2, or 3 double-bonds). Individual and group behavioral tests revealed different preferences in larvae and adults. Larvae preferred UFAs whereas SFAs tended to induce both a strong aversion and a persistent aggregation behavior. Adults generally preferred SFAs, and laid more eggs and had a longer life span when ingesting these substances as compared to UFAs. Our data suggest that insects can discriminate long-chain dietary FAs. The developmental change in preference shown by this species might reflect functional variation in use of FAs or stage-specific nutritional requirements, and may be fundamental for insect use of these major dietary components

    Mahatma Gandhi and the Prisoner’s Dilemma: Strategic Civil Disobedience and Great Britain’s Great Loss of Empire in India

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    This paper examines the relationship between statutory monopoly and collective action as a multi-person assurance game culminating in an end to British Empire in India. In a simple theoretical model, it is demonstrated whether or not a collective good enjoys (or is perceived to enjoy) pure jointness of production and why the evolutionary stable strategy of non-violence was supposed to work on the principle that the coordinated reaction of a ethnically differentiated religious crowd to a conflict between two parties (of colonizer and colonized) over confiscatory salt taxation would significantly affect its course. Following Mancur Olson (1965) and Dennis Chong (1991), a model of strategic civil disobedience is created which is used to demonstrate how collective action can be used to produce an all-or-nothing public good to achieve economic and political independence

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Accounting: A General Commentary on an Empirical Science

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    Many researchers have questioned the view of accounting as a science. Some maintain that it is a service activity rather than a science, yet others entertain the view that it is an art or merely a technology. While it is true that accounting provides a service and is a technology (a methodology for recording and reporting), that fact does not prevent accounting from being a science. Based upon the structure and knowledge base of the discipline, this paper presents the case for accounting as an empirical science

    Another Look at the Transactions Demand for Money in Nigeria

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    The Promise of Positive Optimal Taxation

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