Monetary union and fiscal federalism

Does a monetary union need fiscal shock absorbers helping the participating countries to cope with asymmetric shocks? The consensus in the debate over EMU argues that the answer is yes. In this paper, we revisit the issue, building on a dynamic, general equilibrium framework of regions in a monetary union exposed to asymmetric shocks. We show that inter-regional taxes and transfers can stabilize regional employment or consumption, but not both. The welfare effects of such stabilization are, however, ambiguous. In contrast to a popular argument in the EMU debate, inter-regional taxes and transfers do not reduce the incentives for goods and labor market deregulation in the regions, provided that the degree of trade integration among the regions is large. There is, however, reason to coordinate regional reform policies to avoid adverse effects on the aggregate performance of the union. --

07291 Abstracts Collection -- Scientific Visualization

From 15.07. to 20.07.07, the Dagstuhl Seminar 07291 ``Scientific Visualization\u27\u27 was held in the International Conference and Research Center (IBFI),Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

Generation of mature T cells from human hematopoietic stem and progenitor cells in artificial thymic organoids

Studies of human T cell development require robust model systems that recapitulate the full span of thymopoiesis, from hematopoietic stem and progenitor cells (HSPCs) through to mature T cells. Existing in vitro models induce T cell commitment from human HSPCs; however, differentiation into mature CD3^+TCR-αβ^+ single-positive CD8^+ or CD4^+ cells is limited. We describe here a serum-free, artificial thymic organoid (ATO) system that supports efficient and reproducible in vitro differentiation and positive selection of conventional human T cells from all sources of HSPCs. ATO-derived T cells exhibited mature naive phenotypes, a diverse T cell receptor (TCR) repertoire and TCR-dependent function. ATOs initiated with TCR-engineered HSPCs produced T cells with antigen-specific cytotoxicity and near-complete lack of endogenous TCR Vβ expression, consistent with allelic exclusion of Vβ-encoding loci. ATOs provide a robust tool for studying human T cell differentiation and for the future development of stem-cell-based engineered T cell therapies

In situ probe of photocarrier dynamics in water-splitting hematite (α-Fe_(2)O_3) electrodes

The spectra and dynamics of photogenerated electrons and holes in excited hematite (α-Fe_(2)O_3) electrodes are investigated by transient absorption (from visible to infrared and from femto- to micro-seconds), bias-dependent differential absorption and Stark spectroscopy. Comparison of results from these techniques enables the assignment of the spectral signatures of photogenerated electrons and holes. Under the pulse illumination conditions of transient absorption (TA) measurement, the absorbed photon to electron conversion efficiency (APCE) of the films at 1.43 V (vs. reversible hydrogen electrode, RHE) is 0.69%, significantly lower than that at AM 1.5. TA kinetics shows that under these conditions, >98% of the photogenerated electrons and holes have recombined by 6 μs. Although APCE increases with more positive bias (from 0.90 to 1.43 V vs. RHE), the kinetics of holes up to 6 μs show negligible change, suggesting that the catalytic activity of the films is determined by holes with longer lifetimes

The promoter from SlREO, a highly-expressed, root-specific Solanum lycopersicum gene, directs expression to cortex of mature roots

Root-specific promoters are valuable tools for targeting transgene expression, but many of those already described have limitations to their general applicability. We present the expression characteristics of SlREO, a novel gene isolated from tomato (Solanum lycopersicum L.). This gene was highly expressed in roots but had a very low level of expression in aerial plant organs. A 2.4-kb region representing the SlREO promoter sequence was cloned upstream of the uidA GUS reporter gene and shown to direct expression in the root cortex. In mature, glasshouse-grown plants this strict root specificity was maintained. Furthermore, promoter activity was unaffected by dehydration or wounding stress but was somewhat suppressed by exposure to NaCl, salicylic acid and jasmonic acid. The predicted protein sequence of SlREO contains a domain found in enzymes of the 2-oxoglutarate and Fe(II)-dependent dioxygenase superfamily. The novel SlREO promoter has properties ideal for applications requiring strong and specific gene expression in the bulk of tomato root tissue growing in soil, and is also likely to be useful in other Solanaceous crop

The 5-6 December 1991 FIRE IFO 2 Jet Stream Cirrus Case Study: Possible Influences of Volcanic Aerosols

In presenting an overview of the cirrus clouds comprehensively studied by ground based and airborne sensors from Coffeyville, Kansas, during the 5-6 December 1992 First ISCCP Regional Experiment (FIRE) intensive field observation (IFO) case study period, evidence is provided that volcanic aerosols from the June 1991 Pinatubo eruptions may have significantly influenced the formation and maintenance of the cirrus. Following the local appearance of a spur of stratospheric volcanic debris from the subtropics, a series of jet streaks subsequently conditioned the troposphere through tropopause foldings with sulfur based particles that became effective cloud forming nuclei in cirrus clouds. Aerosol and ozone measurements suggest a complicated history of stratospheric-tropospheric exchanges embedded with the upper level flow, and cirrus cloud formation was noted to occur locally at the boundaries of stratospheric aerosol enriched layers that became humidified through diffusion, precipitation, or advective processes. Apparent cirrus cloud alterations include abnormally high ice crystal concentrations (up to approximately 600 L(exp. 1)), complex radial ice crystal types, and relatively large haze particles in cirrus uncinus cell heads at temperatures between -40 and -50 degrees C. Implications for volcanic-cirrus cloud climate effects and unusual (nonvolcanic) aerosol jet stream cirrus cloud formation are discussed