Bundling and Competition for Slots: Sequential Pricing

In this paper we study, as in Jeon-Menicucci (2009), competition between sellers when each of them sells a portfolio of distinct products to a buyer having limited slots. This paper considers sequential pricing and complements our main paper (Jeon- Menicucci, 2009) that considers simultaneous pricing. First, Jeon-Menicucci (2009) find that under simultaneous individual pricing, equilibrium often does not exist and hence the outcome is often inefficient. By contrast, equilibrium always exists under sequential individual pricing and we characterize it in this paper. We find that each seller faces a trade-off between the number of slots he occupies and surplus extraction per product, and there is no particular reason that this leads to an efficient allocation of slots. Second, Jeon Menicucci (2009) find that when bundling is allowed, there always exists an efficient equilibrium but inefficient equilibria can also exist due to pure bundling (for physical products) or slotting contracts. Under sequential pricing, we find that all equilibria are efficient regardless of whether firms can use slotting contracts, and both for digital goods and for physical goods. Therefore, sequential pricing presents an even stronger case for laissez-faire in the matter of bundling than simultaneous pricing.

J/psi Production and Absorption in High Energy Proton-Nucleus Collisions

Measured J/Psi production cross sections for 200 and 450 GeV/c protons incident on a variety of nuclear targets are analyzed within a Glauber framework which takes into account energy loss of the beam proton, the time delay of particle production due to quantum coherence, and absorption of the J/Psi on nucleons. The best representation is obtained for a coherence time of 0.5 fm/c, previously determined by Drell-Yan production in proton-nucleus collisions, and an absorption cross section of 3.6 mb, which is consistent with the value deduced from photoproduction of the J/Psi on nuclear targets.Comment: LaTeX2e, 7 pages, 4 PS figures. Typos removed, minor change

Drell-Yan and J/psi Production in High Energy Proton-Nucleus and Nucleus-Nucleus Collisions

The distributions of outgoing protons and charged hadrons in high energy proton-nucleus collisions are described rather well by a linear extrapolation from proton-proton collisions. This linear extrapolation is applied to precisely measured Drell-Yan cross sections for 800 GeV protons incident on a variety of nuclear targets. The deviation from linear scaling in the atomic number A can be accounted for by energy degradation of the proton as it passes through the nucleus if account is taken of the time delay of particle production due to quantum coherence. We infer an average proper coherence time of 0.4 +/- 0.1 fm/c. Then we apply the linear extrapolation to measured J/psi production cross sections for 200 and 450 GeV/c protons incident on a variety of nuclear targets. Our analysis takes into account energy loss of the beam proton, the time delay of particle production due to quantum coherence, and absorption of the J/psi on nucleons. The best representation is obtained for a coherence time of 0.5 fm/c, which is consistent with Drell-Yan production, and an absorption cross section of 3.6 mb, which is consistent with the value deduced from photoproduction of the J/psi on nuclear targets. Finally, we compare to recent J/psi data from S+U and Pb+Pb collisions at the SPS. The former are reproduced reasonably well with no new parameters, but not the latter.Comment: Talks given at Quark Matter '99, the 14th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions, Torino, Italy, May 10-14, 1999. 10 pages, five figure

Dynamics of end to end loop formation for an isolated chain in viscoelastic fluid

We theoretically investigate the looping dynamics of a linear polymer immersed in a viscoelastic fluid. The dynamics of the chain is governed by a Rouse model with a fractional memory kernel recently proposed by Weber et al. (S. C. Weber, J. A. Theriot, and A. J. Spakowitz, Phys. Rev. E 82, 011913 (2010)). Using the Wilemski-Fixman (G. Wilemski and M. Fixman, J. Chem. Phys. 60, 866 (1974)) formalism we calculate the looping time for a chain in a viscoelastic fluid where the mean square displacement of the center of mass of the chain scales as t^(1/2). We observe that the looping time is faster for the chain in viscoelastic fluid than for a Rouse chain in Newtonian fluid up to a chain length and above this chain length the trend is reversed. Also no scaling of the looping time with the length of the chain seems to exist for the chain in viscoelastic fluid

Bundling and Competition for Slots: Sequential Pricing

In this paper we study, as in Jeon-Menicucci (2009), competition between sellers when each of them sells a portfolio of distinct products to a buyer having limited slots. This paper considers sequential pricing and complements our main paper (Jeon- Menicucci, 2009) that considers simultaneous pricing. First, Jeon-Menicucci (2009) find that under simultaneous individual pricing, equilibrium often does not exist and hence the outcome is often inefficient. By contrast, equilibrium always exists under sequential individual pricing and we characterize it in this paper. We find that each seller faces a trade-off between the number of slots he occupies and surplus extraction per product, and there is no particular reason that this leads to an efficient allocation of slots. Second, Jeon Menicucci (2009) find that when bundling is allowed, there always exists an efficient equilibrium but inefficient equilibria can also exist due to pure bundling (for physical products) or slotting contracts. Under sequential pricing, we find that all equilibria are efficient regardless of whether firms can use slotting contracts, and both for digital goods and for physical goods. Therefore, sequential pricing presents an even stronger case for laissez-faire in the matter of bundling than simultaneous pricing

Re: Perineural Invasion By Transitional Cell Carcinoma Of The Bladder In Patients Submitted To Radical Cystectomy: What Is The Prognostic Value? [2]

[No abstract available]333422Leissner, J., Koeppen, C., Wolf, H.K., Prognostic significance of vascular and perineural invasion in urothelial bladder cancer treated with radical cystectomy (2003) J Urol, 169, pp. 955-960Hong, S.K., Kwak, C., Jeon, H.G., Lee, E., Lee, S.E., Do vascular, lymphatic, and perineural invasion have prognostic implications for bladder cancer.after radical cystectomy? (2005) Urology, 65, pp. 697-70

Nonperturbative calculation of the shear viscosity in hot phi**4 theory in real time

Starting from the Kubo formula we calculate the shear viscosity in hot phi**4 theory nonperturbatively by resumming ladders with a real-time version of the Bethe-Salpeter equation at finite temperature. In the weak coupling limit, the generalized Fluctuation-Dissipation Theorem is shown to decouple the Bethe-Salpeter equations for the different real-time components of the 4-point function. The resulting scalar integral equation is identical with the one obtained by Jeon using diagrammatic ``cutting rules'' in the Imaginary Time Formalism.Comment: 4 pages LateX. The 2 postscript figures are now incorporated into the text, facilitating download. No other changes. Accepted by Physics Letters

Acceptance Dependence of Fluctuation in Particle Multiplicity

The effect of limiting the acceptance in rapidity on event-by-event multiplicity fluctuations in nucleus-nucleus collisions has been investigated. Our analysis shows that the multiplicity fluctuations decrease when the rapidity acceptance is decreased. We explain this trend by assuming that the probability distribution of the particles in the smaller acceptance window follows binomial distribution. Following a simple statistical analysis we conclude that the event-by-event multiplicity fluctuations for full acceptance are likely to be larger than those observed in the experiments, since the experiments usually have detectors with limited acceptance. We discuss the application of our model to simulated data generated using VENUS, a widely used event generator in heavy-ion collisions. We also discuss the results from our calculations in presence of dynamical fluctuations and possible observation of these in the actual data.Comment: To appear in Int. J. Mod. Phys.

Boston University String Chamber Music Concert, December 15, 1987

This is the concert program of the Boston University String Chamber Music Concert on Tuesday, December 15, 1987 at 7:00 p.m., at the Marshall Room, 855 Commonwealth Avenue. Works performed were Trio in A minor, Op. 114 by Johannes Brahms, Quartet, Op. 77, No. 1 by Franz Joseph Haydn, Piano trio in C major, Op. 87 by J. Brahms, Leichtes trio, Op. 26 by Leonard De Call, and Allegro vivace from "Trout" Quintet, Op. 114 by Franz Schubert. Digitization for Boston University Concert Programs was supported by the Boston University Humanities Library Endowed Fund

Electric charge susceptibility in 2+1 flavour QCD on an anisotropic lattice

The FASTSUM Collaboration presents its first results for the electric charge susceptibility in QCD using 2+1 dynamical flavours of Wilson quark on anisotropic lattices. Spatial volumes of (2.94 fm)^3 are used at fixed cut-off with temperatures ranging from below T_c to ~2 T_c.Comment: 7 pages, 4 figures, poster contribution to the 31st International Symposium on Lattice Field Theory (Lattice 2013), July 29-August 3 2013, Mainz, German