The Taste for Variety: A Hedonic Analysis

Based on the model of consumers' variety-seeking behavior introduced by Anderson et al. (1992), this paper derives a hedonic price function for a households' consumption bundle. The price a consumer pays for her consumption bundle reflects the values of the underlying attributes of goods purchased but also accounts for any preference for variety that she might have. The empirical analysis is conducted for 3,240 German households and their expenditure on 182 different soft drinks over a six-month period. We find that consumers have a preference for variety in food consumption, ceteris paribus. Furthermore, the per-unit price is found to be significantly larger for higher income households, as well as households where the principal wage earner has a high level of education. Larger households tend to spend less on soft drinks per unit.consumer demand, taste for variety, food products, hedonic analysis, Germany, Food Consumption/Nutrition/Food Safety, C21, D12,

The centrality dependence of v2/epsilon: the ideal hydro limit and eta/s

The large elliptic flow observed at RHIC is considered to be evidence for almost perfect liquid behavior of the strongly coupled quark-gluon plasma produced in the collisions. In these proceedings we present a two parameter fit for the centrality dependence of the elliptic flow scaled by the spatial eccentricity. We show by comparing to viscous hydrodynamical calculations that these two parameters are in good approximation proportional to the shear viscosity over entropy ratio and the ideal hydro limit of the ratio v2/epsilon.Comment: 4 pages, 8 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee - final version without line number

Influence of Low Energy Hadronic Interactions on Air-shower Simulations

Experiments measuring cosmic rays above an energy of 10^14 eV deduce the energy and mass of the primary cosmic ray particles from air-shower simulations. We investigate the importance of hadronic interactions at low and high energies on the distributions of muons and electrons in showers on ground. In air shower simulation programs, hadronic interactions below an energy threshold in the range from 80 GeV to 500 GeV are simulated by low energy interaction models, like Fluka or Gheisha, and above that energy by high energy interaction models, e.g. Sibyll or QGJSJet. We find that the impact on shower development obtained by switching the transition energy from 80 GeV to 500 GeV is comparable to the difference obtained by switching between Fluka and Gheisha.Comment: 4 pages, 6 figures, ISVHECRI 200

A fast hybrid approach to air shower simulations and applications

The SENECA model, a new hybrid approach to air shower simulations, is presented. It combines the use of efficient cascade equations in the energy range where a shower can be treated as one-dimensional, with a traditional Monte Carlo method which traces individual particles. This allows one to reproduce natural fluctuations of individual showers as well as the lateral spread of low energy particles. The model is quite efficient in computation time. As an application of the new approach, the influence of the low energy hadronic models on shower properties for AUGER energies is studied. We conclude that these models have a significant impact on the tails of lateral distribution functions, and deserve therefore more attention

Bestimmungsgründe der regionalen Marktstruktur im deutschen Lebensmitteleinzelhandel

Die öffentliche Diskussion über die Struktur des Lebensmitteleinzelhandels in Deutschland ist durch die Sorge über ein hohes Niveau (bzw. die weitere Zunahme) der Konzentration auf Unternehmensebene sowie eine Abnahme der Zahl der Verkaufsstätten geprägt. Die vorliegende Arbeit sucht nach Bestimmungsfaktoren der Anbieterstruktur auf regionaler Ebene für 50 deutsche Städte in der Periode 1993 bis 1999. Die ökonometrischen Schätzungen legen nahe, dass die Marktstruktur in der Ausgangssituation sowie Kosten- und Nachfragefaktoren die Zahl der Verkaufsstätten signifikant beeinflussen. Kleine Städte mit hohen und rasch steigenden Lohnkosten, einem hohen und zunehmendem Mietniveau sowie einer steigenden Arbeitslosenrate weisen einen signifikant stärkeren Rückgang der Zahl der Verkaufsstätten aus. Die Anbieterkonzentration wird primär durch Kostenfaktoren bestimmt, sie steigt mit dem Niveau der Miet- und Lohnkosten signifikant an. --Konzentration,Zahl der Verkaufsstätten,Lebensmitteleinzelhandel,deutsche Städte

Remnant Break-up and Muon Production in Cosmic Ray Air Showers

We discuss the relation between remnant fragmentation in inelastic high-energy hadronic interactions and muon production in extensive cosmic ray air showers. Using a newly developed tool, a simple and flexible hadronic event generator, we analyze the forward region of hadronic interactions. We show that measurements of the Feynman-x distribution in the beam fragmentation region at LHCf will be key to understanding muon production in air showers quantitatively.Comment: 6 pages, 6 figure

Impact of Uncertainties in Hadron Production on Air-Shower Predictions

At high energy, cosmic rays can only be studied by measuring the extensive air showers they produce in the atmosphere of the Earth. Although the main features of air showers can be understood within a simple model of successive interactions, detailed simulations and a realistic description of particle production are needed to calculate observables relevant to air shower experiments. Currently hadronic interaction models are the main source of uncertainty of such simulations. We will study the effect of using different hadronic models available in CORSIKA and CONEX on extensive air shower predictions.Comment: 12 pages, 6 figures, to appear in the proceedings of International Conference on Interconnection between High Energy Physics and Astroparticle Physics: From Colliders to Cosmic Rays, Prague, Czech Republic, 7-13 Sep 200

NeXSPheRIO results on elliptic flow at RHIC and connection with thermalization

Elliptic flow at RHIC is computed event-by-event with NeXSPheRIO. Reasonable agreement with experimental results on $v_2(\eta)$ is obtained. Various effects are studied as well: reconstruction of impact parameter direction, freeze out temperature, equation of state (with or without crossover), emission mecanism.Comment: Contribution to the Proceedings of the Quark-Gluon Plasma Thermalization workshop. Content slightly increase

Zerebrale Protektionssysteme bei der Stentimplantation der Arteria carotis

Das Ziel der Studie war die Evaluation der Ergebnisse der Stentimplantation in die Arteria carotis interna (ACI) unter zerebraler Protektion. In die Studie konnten 110 Patienten eingeschlossen werden. Der durchschnittliche Stenosegrad betrug 79,1% (65-97%). Die Erfolgsrate der Stentimplantation betrug 98,2%. Bei 66 Patienten konnte die Stenose vollständig beseitigt werden. In 76 Fällen wurde das Okklusionssystem, in 32 Fällen das Filtrationssystem verwendet. Es ereigneten sich 12 transitorische ischämische Attacken (TIA)(11,1%), 3 minor Strokes (2,8%) und 1 major Stroke (0,9%). Todesfälle ereigneten sich nicht. Die kombinierte Morbiditäts- und Mortalitätsrate nach 30 Tagen betrug 4,6%. Im DW-MRT waren bei 23 Patienten (24,5%) nach der Behandlung ipsilaterale Läsionen nachweisbar. Die durchschnittliche Läsionsrate pro Patient betrug 4,3 (1-14). Durch zerebrale Protektion bei der endovaskulären Behandlung von Karotisstenosen könnte eine Verringerung der Komplikationsrate erreicht werden