This is one of the first highly efficient methods for asymmetric intermolecular hydroamination of alkenes, where the reaction proceeds with both high enantioselectivity and excellent reactivity. It was established earlier that in the presence of fluoride anions either selectivity or yields are improved. The significance of this report is the introduction of novel reaction conditions, more specific use of silyl base, which provide products in high yields and selectivities. Further, the authors have shown the efficiency of the methodology with simple manipulation of arylamine products to produce functionalized, enantioenriched cyclopentylamines with three stereocenters.
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This paper discusses congestion control from a game-theoretic perspective. There are two basic premises: (1) users are assumed to be independent and selfish, and (2) central administrative control is exercised only at the network switches. The operating points resulting from selfish user behavior depend crucially on the service disciplines implemented in network switches. This effect is investigated in a simple model consisting of a single exponential server shared by many Poisson sources. We discuss the extent to which one can guarantee, through the choice of switch service disciplines, that these selfish operating points will be efficient and fair. We also discuss to what extent the choice of switch service disciplines can ensure that these selfish operating points are unique and are easily and rapidly accessible by simple self-optimization techniques. We show that no service discipline can guarantee optimal efficiency. As for the other properties, we show that the traditional FIFO service discipline guarantees none of these properties, but that a service discipline called Fair Share guarantees all of them. While the treatment utilizes game-theoretic concepts, no previous knowledge of game theory is assumed.
The Internet's core routing infrastructure, while arguably robust and efficient, has proven to be difficult to evolve to accommodate the needs of new applications. Prior research on this problem has included new hard-coded routing protocols on the one hand, and fully extensible Active Networks on the other. In this paper, we explore a new point in this design space that aims to strike a better balance between the extensibility and robustness of a routing infrastructure. The basic idea of our solution, which we call declarative routing , is to express routing protocols using a database query language. We show that our query language is a natural fit for routing, and can express a variety of well-known routing protocols in a compact and clean fashion. We discuss the security of our proposal in terms of its computational expressive power and language design. Via simulation, and deployment on PlanetLab, we demonstrate that our system imposes no fundamental limits relative to traditional protocols, is amenable to query optimizations, and can sustain long-lived routes under network churn and congestion.
Global industrial production continues to recover – something for which policy deserves considerable credit (as we have argued on this site, see Almunia et al 2009 and O’Rourke and Eichengreen 2009). But before indulging in selfcongratulation, policymakers should note that the level of industrial production is still 6% below its previous peak (figure 1). (At the trough it was 13% below its previous peak.) It follows that considerable excess capacity remains in a number of important economies. Exiting now from policies of stimulus in those countries would therefore be premature.
