916 research outputs found

    The Modified Pharaoh Approach: Stingless bees mummify beetle parasites alive

    Get PDF
    Social insect colonies usually live in nests, which are often invaded by parasitic species^1^. Workers from these colonies use different defence strategies to combat invaders^1^. Nevertheless, some parasitic species are able to bypass primary colony defences due to their morphology and behaviour^1-3^. In particular, some beetle nest invaders cannot be killed or removed by workers of social bees^2-5^, thus creating the need for alternative social defence strategies to ensure colony survival. Here we show, using Diagnostic Radioentomology^6^, that stingless bee workers _Trigona carbonaria_, immediately mummify invading destructive nest parasites _Aethina tumida_ alive, with a mixture of resin, wax and mud, thereby preventing severe damage to the colony. In sharp contrast to the responses of honeybee^7^ and bumblebee colonies^8^, the rapid live mummification strategy of _T. carbonaria_ effectively prevents beetle parasite advancements and removes their ability to reproduce. The convergent evolution of live mummification by stingless bees and social encapsulation by honeybees^3^ suggests that colonies of social bees generally rely on, secondary defence mechanisms when harmful nest intruders cannot be killed or ejected easily. This process is analogous to immune responses in animals

    Strategic maritime container transport design in oligopolistic markets

    Get PDF
    AbstractThis paper considers the maritime container assignment problem in a market setting with two competing firms. Given a series of known, exogenous demands for service between pairs of ports, each company is free to design a liner service network serving a subset of the ports and demand, subject to the size of their fleets and the potential for profit. The model is designed as a three-stage complete information game: in the first stage, the firms simultaneously invest in their fleet; in the second stage, they individually design their networks and solve the route assignment problem with respect to the transport demand they expect to serve, given the fleet determined in the first stage; in the final stage, the firms compete in terms of freight rates on each origin-destination movement. The game is solved by backward induction. Numerical solutions are provided to characterize the equilibria of the game

    WESTERN NEW ENGLAND COLLEGE SCHOOL OF LAW CONVOCATION SPEECH

    Get PDF

    University of Akron School of Law Commencement Address

    Get PDF
    University of Akron School of Law Commencement Address...I want to talk with you today about the place of the lawyer in society – your place in society. About the challenges that now confront lawyers and our profession. And about how we must respond to those challenges. I begin with the importance of an independent legal profession in America

    It\u27s Not Triage if the Patient Bleeds Out

    Get PDF

    It\u27s Not Triage if the Patient Bleeds Out

    Get PDF
    • …
    corecore