31 research outputs found

    Foundation Movement Monitoring of Heavy Structures – A Case History

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    Accurate monitoring of settlement beneath the main structures of a nuclear power plant not only demonstrates the stability of the structures, but also confirms predicted settlements, thereby verifying the geotechnical parameters used in the design. At the Grand Gulf Nuclear Station near Port Gibson, Mississippi, rebound and settlement monitoring has been continuous since the start of site excavation in 1974. As a result, actual settlements have been shown to be close to the predicted levels. This paper discusses the planning, installation and monitoring of the settlement instrumentation and reviews the factors that were important to the choice of instrumentation

    Nature's Swiss Army Knives: Ovipositor Structure Mirrors Ecology in a Multitrophic Fig Wasp Community

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    Resource partitioning is facilitated by adaptations along niche dimensions that range from morphology to behaviour. The exploitation of hidden resources may require specially adapted morphological or sensory tools for resource location and utilisation. Differences in tool diversity and complexity can determine not only how many species can utilize these hidden resources but also how they do so.The sclerotisation, gross morphology and ultrastructure of the ovipositors of a seven-member community of parasitic wasps comprising of gallers and parasitoids developing within the globular syconia (closed inflorescences) of Ficus racemosa (Moraceae) was investigated. These wasps also differ in their parasitism mode (external versus internal oviposition) and their timing of oviposition into the expanding syconium during its development. The number and diversity of sensilla, as well as ovipositor teeth, increased from internally ovipositing to externally ovipositing species and from gallers to parasitoids. The extent of sclerotisation of the ovipositor tip matched the force required to penetrate the syconium at the time of oviposition of each species. The internally ovipositing pollinator had only one type of sensillum and a single notch on the ovipositor tip. Externally ovipositing species had multiple sensilla types and teeth on their ovipositors. Chemosensilla were most concentrated at ovipositor tips while mechanoreceptors were more widely distributed, facilitating the precise location of hidden hosts in these wasps which lack larval host-seeking behaviour. Ovipositor traits of one parasitoid differed from those of its syntopic galler congeners and clustered with those of parasitoids within a different wasp subfamily. Thus ovipositor tools can show lability based on adaptive necessity, and are not constrained by phylogeny.Ovipositor structure mirrored the increasingly complex trophic ecology and requirements for host accessibility in this parasite community. Ovipositor structure could be a useful surrogate for predicting the biology of parasites in other communities

    Strong equilibrium outcomes of voting games ¶are the generalized Condorcet winners

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    We consider voting games induced by anonymous and top-unanimous social choice functions. The class of such social choice functions is quite broad, including every “t-refinement” of the Plurality Rule, Plurality with a Runoff, the Majoritarian Compromise and the Single Transferable Vote, i.e., any selection from either of these social choice rules which is obtained via tie-breaking among candidates according to any total order t on the set of alternatives. As announced in our title, the strong equilibrium outcomes of the voting games determined by such social choice functions turn out to be nothing but generalized Condorcet winners, namely the “(n,q)-Condorcet winners”. In the case of social choice functions (such as those just listed) which are furthermore “top-majoritarian”, they coincide with the classical Condorcet winners. Copyright Springer-Verlag 2004

    Monotonicity and qualified majority rules

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