25,950 research outputs found

    HQET Flavor Currents Using Automated Lattice Perturbation Theory

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    Matrix elements of heavy-light flavor currents play an important role in modern particle physics and precise theory predictions are of interest for phenomenology. Heavy Quark Effective Theory (HQET) is a valuable tool to obtain such predictions. In the HQET matching program of the ALPHA collaboration presently only the temporal component of the axial vector current is included. Extending the matching to the temporal component of the vector current and the spatial components of the axial vector current thus seems desirable. Here we present a recent one-loop study in lattice perturbation theory to test two candidate matching observables for these currents for their quality to guide future non-perturbative investigations.Comment: 7 pages, 4 figures. To be published in: Proceedings of the 30th International Symposium on Lattice Field Theory, June 24 - 29, 2012, Cairns, Australi

    Accepting the Challenges: The Emerging Role of Grand Rapids Community College in Preparation of New Teachers

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    In 1992, Grand Rapids Community College (GRCC) was one of six community colleges invited to participate in a NSF initiative to improve science and mathematics teaching within the state of Michigan. This initiative included all public teacher preparation institutions in the state. GRCC has responded to this challenge by: (1) designing a new course in Physical Science for future teachers; (2) creating the GRCC Teacher Education Pathway and the GRCC Teacher Education Center; (3) forming a local alliance with Grand Rapids Public Schools and Grand Valley State University for the purpose of recruiting and supporting minorities in mathematics and science teaching

    Financial intermediation in the pre-consolidated banking sector in Nigeria

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    This paper uses unique bank-by-bank balance sheet and income statement information to investigate the intermediation efficiency in the Nigerian pre-consolidated banking sector during 2000-05. The author analyzes whether the Central Bank of Nigeria's policy of recent banking consolidation can be justified and rationalized by looking at the determinants of spreads. A spread decomposition and panel estimations show that the reform of the banking sector could be the first step to raise the intermediation efficiency of the Nigerian banking sector. The author finds that larger banks have enjoyed lower overhead costs, increased concentration in the banking sector has not been detrimental to the spreads, both increased holdings of liquidity and capital might have led to lower spreads in 2005, and a stable macroeconomic environment is conducive to a more efficient channeling of savings to productive investments.Banks&Banking Reform,Economic Theory&Research,Financial Intermediation,Financial Crisis Management&Restructuring,Investment and Investment Climate

    Logistics real estate markets: indicators of structural change, linking land use and freight transport

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    The system of physical distribution that comprises transport and logistics, warehousing and wholesale, is an ideal indicator of structural change. Distribution and logistics have developed dynamically, with respect to new technologies, corporate restructuring, and a changing market environment. Whereas traditional logistics were characterized primarily by the demand of manufacturing customers for the shipment of bulk-commodities, modern production and service systems require frequent deliveries over great distances, with high inventory turnovers instead of storage. As a consequence, the locational profiles of distribution firms have changed as well, both at a large-scale level and within metropolitan regions. Based on recent findings of the European Warehousing Index, the paper points out how the European system of goods movement has changed in terms of regional distribution markets and warehousing location. Secondly, the consequences of locational dynamics within metropolitan regions are considered. The dominance of the truck and the suburbanisation of large distribution centres raise serious concern about logistics management, traffic reduction and locational policy. Referring to selected places such as the Ruhr Area, Hamburg or Berlin-Brandenburg, the paper demonstrates how critical the relationship between cities and goods distribution is becoming, with regard both to the regional economy and the urban environment. Is there a chance for regional, spatially oriented management of supply chains? In the case of the Ruhr Area, it is also questioned whether a certain 'knowledge milieu' (logistics research, applied sciences) may contribute to this goal. The particular benefits of investigating logistics real estate markets are fourfold: - They allow for a precise insight into regionally differentiated developments. - They connect the system of 'flows' with material 'space'. - They demonstrate that structural change is by no means neutral for the environment, regarding specific transport and land use implications of distribution. - They represent the emergence of new players in land use planning and policy (i.e. developers), thus shaping the system of political regulation.

    The role of the Weibel instability at the reconnection jet front in relativistic pair plasma reconnection

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    The role of the Weibel instability is investigated for the first time in the context of the large-scale magnetic reconnection problem. A late-time evolution of magnetic reconnection in relativistic pair plasmas is demonstrated by particle-in-cell (PIC) simulations. In the outflow regions, powerful reconnection jet piles up the magnetic fields and then a tangential discontinuity appears there. Further downstream, it is found that the two-dimensional extension of the relativistic Weibel instability generates electro-magnetic fields, which are comparable to the anti-parallel or piled-up fields. In a microscopic viewpoint, the instability allows plasma's multiple interactions with the discontinuity. In a macroscopic viewpoint, the instability leads to rapid expansion of the current sheet and then the reconnection jet front further propagates into the downstream. Possible application to the three-dimensional case is briefly discussed.Comment: 25 pages, 9 figures; References and typos are fixe

    Delayed action does not always require the ventral stream : A study on a patient with visual form agnosia

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    Acknowledgements The authors would like to thank D.F. for participating in all our experiments with great patience. We also would like to thank Dr David Carey for his very helpful and insightful comments on an earlier draft of this manuscript. This work was partly funded by a post-doctoral research fellowship awarded to Constanze Hesse by the German Research Council (DFG/HE 6011/1-1).Peer reviewedPostprin

    Environmental Policy and International Competitiveness in a Globalizing World: Challenges for Low-Income Countries in the UNECE Region.

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    This paper addresses a set of conflicting national objectives, that between economic competitiveness and environmental quality. In lower-income economies, the perceived benefits of improved environmental quality may be valued less than in richer economies while the perceived opportunity costs of abatement or compliance may be valued higher especially when they impact employment levels or result in lower wages and profits. There is also the fear that more stringent standards might negatively impact foreign investment as multinationals seek out locations where operating costs are low. As such, these countries are therefore quite concerned about mandating environmental regulations that could impose significant costs on their enterprises and thereby reduce their global competitiveness. In addition there is a free rider problem regarding transboundary pollution as a country can benefit from the higher environmental standards negotiated amongst its neighbours while avoiding all the costs by deciding not to participate themselves. This paper examines environmental policy in the former transition economies. In these countries environmental institutions, especially the government ministries, are weak, regulations are often inadequate, and enforcement efforts need to be improved. At the same time these economies attach a high priority to increasing living standards and view that this can only be achieved by increasing their global competitiveness in a number of non-traditional industries. Nevertheless it is argued that high environmental standards are only a minor factor in determining cost competitiveness for most industries and locational decisions for multinationals. Even to the degree that they might be a competitive disadvantage in the short-run, they can actually turn out to be an advantage in the longer-term as they promote technological upgrading, the efficient use of resources, and can reduce adjustment costs involved with future trade policy initiatives or integration into production-sharing networks. In addition there are other benefits external to the firm including improved public health, increased tourism and additional recreational resources. Furthermore, the costs of undoing degradation, which will be desired at some future date as national incomes rise, can be avoided altogether. Thus in essence, when these dynamic factors are combined with the social benefits, the real costs of setting high environmental standards are much less than what their current costs might suggest.competitiveness, Europe, transition economies, environmental policy, climate change, sustainable development

    Environmental Policy and Competitiveness in a Globalizing World: Challenges for Low-Income Countries in the UNECE Region

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    A major policy goal of low-income countries is to promote the creation of competitive economic capacities in order to achieve sustained growth and raise the material well being of the population. Economic growth is, however, associated with increasing environmental pressures, and the question is to what extent the costs of more stringent environmental policies will affect the competitiveness of domestic firms. This paper examines the empirical evidence on the impact of environmental protection costs on international trade and FDI location decisions and explores the opportunities that the process of technological upgrading, which is a major driving force of economic development, provides for reducing environmental pressures. Also considered are the policies and supportive institutional arrangements that can help to effectively integrate environmental protection into national economic development strategies and thereby promote sustainable production and consumption patterns.Environmental policy, competitiveness, Eastern Europe, transition economies

    Self-regulation of the reconnecting current layer in relativistic pair plasma reconnection

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    We investigate properties of the reconnecting current layer in relativistic pair plasma reconnection. We found that the current layer self-regulates its thickness when the current layer runs out current carriers, and so relativistic reconnection retains a fast reconnection rate. Constructing a steady state Sweet-Parker model, we discuss conditions for the current sheet expansion. Based on the energy argument, we conclude that the incompressible assumption is invalid in relativistic Sweet-Parker reconnection. The guide field cases are more incompressible than the anti-parallel cases, and we find a more significant current sheet expansion.Comment: Accepted for publication in Astrophysical Journal (to appear in vol. 685
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