409 research outputs found

    The new system of contemporaneous reserve requirements

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    Bank reserves ; Monetary policy

    The new bank capital adequacy standards

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    Bank capital ; Banks and banking

    GALEX Observations of the Ultraviolet Halos of NGC 253 and M82

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    We present Galaxy Evolution Explorer (GALEX) images of the prototypical edge-on starburst galaxies M82 and NGC253. Our initial analysis is restricted to the complex of ultraviolet (UV) filaments in the starburst-driven outflows in the galaxy halos. The UV luminosities in the halo are too high to be provided by shock-heated or photoionized gas except perhaps in the brightest filaments in M82, suggesting that most of the UV light is the stellar continuum of the starburst scattered into our line of sight by dust in the outflow. This interpretation agrees with previous results from optical imaging polarimetry in M82. The morphology of the UV filaments in both galaxies shows a high degree of spatial correlation with H-alpha and X-ray emission. This indicates that these outflows contain cold gas and dust, some of which may be vented into the intergalactic medium (IGM). UV light is seen in the ``H-alpha cap'' 11 kpc North of M82. If this cap is a result of the wind fluid running into a pre-existing gas cloud, the gas cloud contains dust and is not primordial in nature but was probably stripped from M82 or M81. If starburst winds efficiently expel dust into the IGM, this could have significant consequences for the observation of cosmologically distant objects.Comment: This paper will be published as part of the Galaxy Evolution Explorer (GALEX) Astrophysical Journal Letters Special Issue. Links to the full set of papers will be available at http://www.galex.caltech.edu/PUBLICATIONS/ after November 22, 200

    Frontiers in quantifying wildlife behavioural responses to chemical pollution

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    Animal behaviour is remarkably sensitive to disruption by chemical pollution, with widespread implications for ecological and evolutionary processes in contaminated wildlife populations. However, conventional approaches applied to study the impacts of chemical pollutants on wildlife behaviour seldom address the complexity of natural environments in which contamination occurs. The aim of this review is to guide the rapidly developing field of behavioural ecotoxicology towards increased environmental realism, ecological complexity, and mechanistic understanding. We identify research areas in ecology that to date have been largely overlooked within behavioural ecotoxicology but which promise to yield valuable insights, including within- and among-individual variation, social networks and collective behaviour, and multi-stressor interactions. Further, we feature methodological and technological innovations that enable the collection of data on pollutant-induced behavioural changes at an unprecedented resolution and scale in the laboratory and the field. In an era of rapid environmental change, there is an urgent need to advance our understanding of the real-world impacts of chemical pollution on wildlife behaviour. This review therefore provides a roadmap of the major outstanding questions in behavioural ecotoxicology and highlights the need for increased cross-talk with other disciplines in order to find the answers

    Measurement of spin correlation in ttbar production using a matrix element approach

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    correlation, assuming that the spin of the top quark is either correlated with the spin of the anti-top quark as predicted by the standard model or is uncorrelated. For the first time we use a matrix-element-based approach to study ttbar spin correlation. We use {ttbar -> W+bW-bbar ->l+nubl-nub} final states produced in ppbar collisions at a center of mass energy sqrt(s)=1.96 TeV, where l denotes an electron or a muon. The data correspond to an integrated luminosity of 5.4 fb-1 and were collected with the dzero detector at the Fermilab Tevatron collider. The result agrees with the standard model prediction. We exclude the hypothesis that the spins of the ttbar are uncorrelated at the 97.7% C.L.Comment: 7 pages, 3 figures, submitted to Phys. Rev. Let

    The origin and maintenance of metabolic allometry in animals

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    Organisms vary widely in size, from microbes weighing 0.1 pg to trees weighing thousands of megagrams - a 10-fold range similar to the difference in mass between an elephant and the Earth. Mass has a pervasive influence on biological processes, but the effect is usually non-proportional; for example, a tenfold increase in mass is typically accompanied by just a four- to sevenfold increase in metabolic rate. Understanding the cause of allometric scaling has been a long-standing problem in biology. Here, we examine the evolution of metabolic allometry in animals by linking microevolutionary processes to macroevolutionary patterns. We show that the genetic correlation between mass and metabolic rate is strong and positive in insects, birds and mammals. We then use these data to simulate the macroevolution of mass and metabolic rate, and show that the interspecific relationship between these traits in animals is consistent with evolution under persistent multivariate selection on mass and metabolic rate over long periods of time
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