2,932 research outputs found

    Some Legal Aspects of International Communications

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    A comparison of success rates of introduced passeriform birds in New Zealand, Australia and the United States

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    In this study, we compiled lists of successful and unsuccessful passeriform introductions to nine sites in New Zealand, Australia and the United States. We limited our analysis to introductions during the 19th century to minimize potential variation in transport modes and habitat quality changes, such as those due to increasing urbanization. We compared introduction success rates at three levels. First we included all passeriforms introduced to any of the sites in the three locations, then we compared the fates of just those species with a European origin and finally we compared success rates of just the 13 species released into all three locations. We found that the pattern of success or failure differed significantly across the three locations: Passeriforms introduced by acclimatization organizations to the United States were significantly more likely to fail than those introduced to New Zealand or Australia. Several species that succeeded in either New Zealand or Australia failed in the United States, even after the introduction of seemingly sufficient numbers

    Institutional Ownership and Return Predictability Across Economically Unrelated Stocks

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    We document strong weekly lead-lag return predictability across stocks from different industries with no customer-supplier linkages (economically unrelated stocks). Between 1980 and 2010, the industry-neutral long-short hedge portfolio earns an average of over 19 basis points per week. This return predictability arises exclusively from pairs of stocks in which there are common institutional owners. This predictability is a new phenomenon which does not originate from the slow information diffusion underlying previously documented lead-lag effects, weekly reversals, momentum, nonsynchronous trading, or other known factors. Our findings suggest that institutional portfolio reallocations can induce return predictability among otherwise unrelated stocks

    The effects of vitamin K1-rich plant foods on the efficacy of the anticoagulant rodenticides chlorophacinone and diphacinone, used against Montane Voles (\u3ci\u3eMicrotus montanus\u3c/i\u3e)

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    Voles can cause significant losses to agriculture and wood fibre production. California growers typically rely on baits containing chlorophacinone and diphacinone to reduce vole population densities, but the efficacy of those rodenticides has been decreasing. One hypothesis suggests that voles are consuming high levels of an antidote (vitamin K1) to the anticoagulants, contained within green leafy plants. We tested that hypothesis by first feeding Montane Voles (Microtus montanus) diets that were high in vitamin K1, and then providing the animals with either: (1) chlorophacinone-containing bait, (2) diphacinone-containing bait, or (3) a control diet. We found that the chlorophacinone-containing bait remained efficacious (100% mortality), whereas the diphacinone-containing bait had a much lower efficacy (60% mortality). When only the diphacinone-containing bait was presented, the efficacy was somewhat better (80%). We infer that a diet rich in vitamin K1 did not negate the effects of the chlorophacinone for voles, and so we recommend its continued use in California unless anticoagulant resistance is known to have developed in the vole population. We hypothesise that: (1) diphacinone has a relatively low efficacy against Montane Voles when compared to chlorophacinone, and (2) this lower efficacy could be further reduced by a vitamin K1-rich diet

    Evidence for Skyrmion crystallization from NMR relaxation experiments

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    A resistively detected NMR technique was used to probe the two-dimensional electron gas in a GaAs/AlGaAs quantum well. The spin-lattice relaxation rate (1/T1)(1/T_{1}) was extracted at near complete filling of the first Landau level by electrons. The nuclear spin of 75^{75}As is found to relax much more efficiently with T→0T\to 0 and when a well developed quantum Hall state with Rxx≃0R_{xx}\simeq 0 occurs. The data show a remarkable correlation between the nuclear spin relaxation and localization. This suggests that the magnetic ground state near complete filling of the first Landau level may contain a lattice of topological spin texture, i.e. a Skyrmion crystal

    A novel software-defined networking controller: The Distributed Active Information Model (DAIM)

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    © 2018 Polish Academy of Sciences. All Rights Reserved. This paper presents a new OpenFlow controller: the Distributed Active Information Model (DAIM). The DAIM controller was developed to explore the viability of a logically distributed control plane. It is implemented in a distributed way throughout a software-defined network, at the level of the switches. The method enables local process flows, by way of local packet switching, to be controlled by the distributed DAIM controller (as opposed to a centralised OpenFlow controller). The DAIM ecosystem is discussed with some sample code, together with flowcharts of the implemented algorithms. We present implementation details, a testing methodology, and an experimental evaluation. A performance analysis was conducted using the Cbench open benchmarking tool. Comparisons were drawn with respect to throughput and latency. It is concluded that the DAIM controller can handle a high throughput, while keeping the latency relatively low. We believe the results to date are potentially very interesting, especially in light of the fact that a key feature of the DAIM controller is that it is designed to enable the future development of autonomous local flow process and management strategies
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