The Gulf Stream Extension Region: Its dynamics and interaction with the atmosphere

The Gulf Stream Extension Region is a key region for meridional heat transport of the Earth system. Its importance for the climate and for seasonal prediction has been increasingly recognized in recent years. However, the dynamics of the ocean in this region are not understood sufficiently. There are basically three mechanisms to explain the observed increase of barotropic transport and the formation of recirculation gyres in the Gulf Stream Extension Region: (i) advection of potential vorticity, (ii) Joint Effect of Baroclinicity and Relief and (iii) eddy momentum flux, of which the latter is investigated in the present work. 16 years of satellite derived surface velocities of weekly resolution are used to compute the eddy momentum flux and its seasonal and NAO related variability. These fluxes were used to drive a diagnostic linear shallow water model to estimate the mean barotropic transport and its variability associated with turbulent momentum flux. The results show that eddy momentum flux is able to drive significant transport in the Gulf Stream Extension Region, enough to explain its observed increase. The barotropic transport streamfunction exhibits northern and southern recirculation gyres between the separation point at Cape Hatteras and the Newfoundland Ridge and also resemble mesoscale circulation features like the Mann eddy. The seasonal transport variability is shown to be large upstream of the Grand Banks of Newfoundland with the strongest signal where the Gulf Stream crosses the New England Seamounts at about 62°W. The NAO appears to significantly affect the strength of the northern and southern recirculation gyres during the winter season leading to an increased mean transport in winters with a positive NAO index

Geometric Construction of AdS Twistors

Time-like geodesics in AdS_4, AdS_5 and AdS_7 are constructed geometrically and independently of choice of AdS coordinates from division algebra spinors of the corresponding AdS groups, explaining and generalising the construction by Claus et al. of AdS_5 twistors.Comment: 11 pp, 1 figur

Sharing Competences: The Impact of Local Institutional Settings on Voter Turnout

Institutions are common predictors of voter turnout. Most research in this field focuses on cross-country comparisons of voting systems, like the impact of compulsory voting or registration systems. Fewer efforts have been devoted to understand the role of local institutions and their impact on political participation. Especially the impact of divided competences in relation to public good provision and its impact on voter turnout has been widely ignored. In the present paper, we analyze the effects of different institutional settings for inter-municipal cooperation on voter turnout. We use data from local elections in Germany, held in 2003 and 2004. Overall, we analyze aggregate voter turnout of 1661 municipalities and find strong evidence for our hypothesis that local institutional settings are influential in this context. Further, our results indicate that the better competences correspond to the spatial dimension of local public goods, the higher should be the voter turnout.voter turnout, local institutions, inter-municipal cooperation

Comparative Analysis of World Market Projections with Special Regard to Wheat Prices

This paper presents a short comparative analysis of USDA and FAPRI projections for world wheat market prices until 2005. The relevance of different model assumptions regarding assumed inflation, exchange rates, policy parameters as well as shifts in demand and production development are discussed. A subsequent section focuses on the problem of a "world market price concept" for evaluating the potential of unsubsidized EU cereal exports. The Annex provides more detailed information on model assumptions and a comparison of other projected values, also including agricultural products other than wheat. Dieses Diskussionspapier stellt eine kurze vergleichende Analyse aktueller USDA- und FAPRI- Projektionen von Weltmarktpreisen fur Weizen bis 2005 vor. Die Relevanz verschiedener Modellannahmen hinsichtlich Inflation, Wechselkurs, Politikparameter und Bestimmungsgrossen von Angebot und Nachfrage werden diskutiert. Einige Uberlegungen zur Problematik eines "Weltmarktpreiskonzeptes" bei der Abschatzung des Potentials unsubventionierter EU Getreideexporte schliessen sich an. Der Anhang stellt detailliertere Informationen zu Modellannahmen sowie den Vergleich weiterer projezierter Kennzahlen bereit, die auch andere Agrarprodukte einschliessen.Demand and Price Analysis,

Spin-dependent electronic hybridization in a rope of carbon nanotubes

We demonstrate single electron addition to different strands of a carbon nanotube rope. Anticrossings of anomalous conductance peaks occur in quantum transport measurements through the parallel quantum dots forming on the individual strands. We determine the magnitude and the sign of the hybridization as well as the Coulomb interaction between the carbon nanotube quantum dots, finding that the bonding states dominate the transport. In a magnetic field the hybridization is shown to be selectively suppressed due to spin effects.Comment: 4 pages, 4 figure

The Effects of Different Emoticons on the Perception of Emails in the Workplace

Non-verbal communication cues, e.g. facial expressions, and their surrogates in computer-mediated communication, emoticons, influence how a message is understood. Based on the four-ear model of communication, we examine in detail how emoticons affect message perception. More specifically, we examine the different effects of three emoticons [:-) :-( ;-)] on the four levels that define communication. Using a factorial survey with a treatment control group design (N = 231), our findings suggest that emoticon usage does not influence the understanding of a message at the factual information and appeal levels. However, we show that the usage of happy and ironic emoticons significantly shapes the subtext of a message, namely the relationship and self-revelation level, whereas sad emoticons do not have such an effect. These findings hold practical implications: Most importantly, senders can use happy and ironic emoticons to soften their email messages’ illocutionary force at the relationship level and self-revelation level