Vector mesons in qqˉqˉq\bar q\bar q systems

A new selection rule is described for the vector mesons in the decuplet representations of flavor SU(3)Comment: 7 pages and 1 figur

Trading European sovereign bonds: the microstructure of the MTS trading platforms

We study the microstructure of the MTS Global Market bond trading system, which is the largest interdealer trading system for Eurozone government bonds. Using a unique new dataset we find that quoted and effective spreads are related to maturity and trading intensity. Securities can be traded on a domestic and EuroMTS platform. We show that despite the apparent fragmentation of trading, both platforms are closely connected in terms of liquidity. We also study the intraday price order flow relation in the Euro bond market. We estimate the price impact of order flow and control for the intraday trading intensity and the announcement of macroeconomic news. The regression results show a larger impact of order flows during announcement days and a higher price impact of trading after a longer period of inactivity. We relate these findings to interdealer trading and to the structure of European bond markets. JEL Classification: F31, C32Bonds markets, Microstructure, order flow

The Effects of Globalization on the Location of Industries in the OECD and European Union

Most international trade theory, whether classical or "new," predictst that increased globalization will be associated with increased locational concentration of particular economic activities, and hence increased specialization of national and regional economies, due to the greater freedom for industries to locate according to comparative advantage and economies of scale, and to integrate production systems based on an internationalization of intermediate goods sourcing. Relatively little empirical evidence exists on whether these predictions are correct. This paper presents the results of a statistical investigation of the trade-location relationship, using the OECD-STAN database, from 1970 to 1995. This investigation shows that in spite of rapidly rising trade, only in a very few industries has the spatial distribution changed substantially over the period studied. While intra-industry trade has risen across-the-board, locational concentration and specialization have increased little, if at all, in the European Union countries, and European economies remain much less specialized than equivalent regions of the USA. The paper then tries to speculate as to why this might be the case. Much of the intra-industry trade observed in Europe is probably not intermediate divisions of labor (production sharing), but head-to-head competition of largely national industries competing around similar products, through cross-market penetration. The question is how they manage to survive as such in an age of globalization. One hypothesis is that there are evolutionary dynamics involved: mature national firms and production clusters have capacities to adapt to changing circumstances which permit them to survive in more open markets. One major technique for adaptation is product differentiation, both horizontal (making the same products as competitors, through uptake of global state-ofthe- art knowledge) and vertical (quality differentiation, based on superior local knowledge). In this sense, the response of the European economies to globalization may reflect fundamentally different evolutionary dynamics from their American counterpart, whose regions integrated early on before they had mature industrial complexes, and where new industries tend to assume highly localized patterns, that serve as locational cores for the entire national industry. Most importantly, all of this implies that we need to develop non-deterministic theories of the relationship between trade and location, which take into account much more than the standard factors of comparative advantage and scale and integrate a dynamic evolutionary perspective.Globalization, locational specialization, product differentiation

Olig2/Plp-positive progenitor cells give rise to Bergmann glia in the cerebellum.

NG2 (nerve/glial antigen2)-expressing cells represent the largest population of postnatal progenitors in the central nervous system and have been classified as oligodendroglial progenitor cells, but the fate and function of these cells remain incompletely characterized. Previous studies have focused on characterizing these progenitors in the postnatal and adult subventricular zone and on analyzing the cellular and physiological properties of these cells in white and gray matter regions in the forebrain. In the present study, we examine the types of neural progeny generated by NG2 progenitors in the cerebellum by employing genetic fate mapping techniques using inducible Cre-Lox systems in vivo with two different mouse lines, the Plp-Cre-ER(T2)/Rosa26-EYFP and Olig2-Cre-ER(T2)/Rosa26-EYFP double-transgenic mice. Our data indicate that Olig2/Plp-positive NG2 cells display multipotential properties, primarily give rise to oligodendroglia but, surprisingly, also generate Bergmann glia, which are specialized glial cells in the cerebellum. The NG2+ cells also give rise to astrocytes, but not neurons. In addition, we show that glutamate signaling is involved in distinct NG2+ cell-fate/differentiation pathways and plays a role in the normal development of Bergmann glia. We also show an increase of cerebellar oligodendroglial lineage cells in response to hypoxic-ischemic injury, but the ability of NG2+ cells to give rise to Bergmann glia and astrocytes remains unchanged. Overall, our study reveals a novel Bergmann glia fate of Olig2/Plp-positive NG2 progenitors, demonstrates the differentiation of these progenitors into various functional glial cell types, and provides significant insights into the fate and function of Olig2/Plp-positive progenitor cells in health and disease