Resale Price Maintenance After Monsanto: A Doctrine Still at War With Itself

In this article, two enforcement officials at the Federal Trade Commission reexamine resale price maintenance in light of the Supreme Court\u27s recent decision in Monsanto Co. v. Spray-Rite Service Corp. Commissioner Calvani and Mr. Berg consider both antitrust law and economic policy in their review of the history of resale price maintenance; they point out the chronic inconsistencies to which this antitrust regime has been subject, and identify these same inconsistencies at work in Monsanto. The authors set forth three theses with respect to Monsanto: first, that the Court intimated a willingness to reconsider at some future time the per se standard of illegality for resale price maintenance; second, that the Court recognized the continuing vitality of the Colgate doctrine, which had been seriously questioned in recent years; and, third, that the Monsanto Court unsuccessfully attempted to delineate a workable evidentiary standard applicable to communications between sellers and resellers when it is alleged that such communications constitute an illegal contract, combination, or conspiracy under section one of the Sherman Act. The authors suggest that, taken together, these elements in Monsanto display a doctrine at war with itself. The authors conclude by examining the possible implications of the Monsanto decision for the future direction of the law of resale price maintenance

Modelling the light-curves of objects tidally disrupted by a black hole

Tidal disruption by massive black holes is a phenomenon, during which a large part of gravitational energy can be released on a very short time-scale. The time-scales and energies involved during X-ray and IR flares observed in Galactic centre suggest that they may be related to tidal disruption events. Furthermore, aftermath of a tidal disruption of a star by super-massive black hole has been observed in some galaxies, e.g. RX J1242.6-1119A. All these discoveries increased the demand for tools for tidal disruption study in curved space-time. Here we summarise our study of general relativistic effects on tidal deformation of stars and compact objects.Comment: 2 pages, to appear in the proceedings of the JENAM 2008, Symposium 7: "Grand Challenges in Computational Astrophysics

The signature of tidal disruption phenomena in the vicinity of a black hole

Tidal effects on clumps of material during random non-stationary accretion onto a black hole produce phenomena with distinct temporal characteristics in observed light-curves. During such non-stationary accretion events, the shape of the accreting object evolves in time, and observable quasi-periodic phenomena with variable quasi-periods are produced. A number of characteristic light-curves, obtained with numerical simulations, will be shown. Their relevance to observed phenomena will be briefly discussed.Comment: 3 pages, 8 figure

Do flares in Sagittarius A* reflect the last stage of tidal capture?

In recent years the case for the presence of 3-4 10^6 M_sun black hole in our Galactic Center has gained strength from results of stellar dynamics observations and from the detection of several rapid X-ray and IR flares observed in the Sagittarius A* from 2000 to 2004. Here we explore the idea that such flares are produced when the central black hole tidally captures and disrupts a small body - e.g. a comet or an asteroid.Comment: 6 pages, 9 figures, acknowledgments added, to appear in the Proceedings of the Albert Einstein's Century International Conference, Paris 200

Frequency-dependent Thermal Response of the Charge System and Restricted Sum Rules in La(2-x)Sr(x)CuO(4)

By using new and previous measurements of the $ab$-plane conductivity $\sigma_1^{ab} (\omega,T)$ of La$_{2-x}$Sr$_x$CuO$_{4}$ (LSCO) it is shown that the spectral weight $W = \int_0^\Omega {\sigma_1^{ab} (\omega,T) d\omega}$ obeys the same law $W = W_0 - B(\Omega) T^2$ which holds for a conventional metal like gold, for $\Omega$'s below the plasma frequency. However $B(\Omega)$, which measures the "thermal response" of the charge system, in LSCO exhibits a peculiar behavior which points towards correlation effects. In terms of hopping models, $B(\Omega)$ is directly related to an energy scale $t_T$, smaller by one order of magnitude than the full bandwidth $t_0 \sim W_0$.Comment: 4 pages with 3 fig

ON THE ROLE OF CYSTATHIONINE-γ-LYASE IN MODULATING TRANSSULFURATION PATHWAY IN THE LENS

In Mammals transsulfuration pathway enables the conversion of homocysteine (Hcy), deriving from methionine (Met) transmetilation, into cysteine (Cys) through two steps, the first catalyzed by cystathionine β-synthase (CBS) and the second one by cystathionine-γ-lyase (CGL). The latter enzyme is considered to catalyze the rate limiting step of the whole process and one of its products, Cys, is the limiting amino acid for glutathione (GSH) synthesis. GSH, is a tripeptide that has the prominent function to balance the cell redox state. This role is particularly important in the lens where the oxidative stress is at the base of senile cataract onset. Experimental evidences obtained in our research unit point out the attention on the possible role of cysteinylglycine (CysGly) (an intermediate of GSH catabolism), in modulating the transsulfuration pathway in cultured bovine lens. Blocking γ-glutamyl transpeptidase (γ-GT), upon action of serine borate, appears to induce an extrasynthesis of GSH, which is released into medium without any change in intralenticular levels; while the supplementation of culture medium with CysGly, impaired the observed GSH extrasynthesis, as the use of PPG that inhibits CGL. Aim of this work was the accomplishment of CGL purification from calf lenses in order to assess the possible regulatory role of CysGly on CGL activity. The purification of CGL from bovine lens resulted a very hard task, since the extremely low activity detectable in the lens extracts. The assembled purification protocol did not allowed the availability of sufficient enzymatic sample to proceed to a characterization. Thus cultured bovine lens epithelial cells (BLEc), for which a CGL specific activity two order of magnitude higher than that measured in the lens extract, were selected as a better source to isolate CGL. The purification of the enzyme from BLEc, even though did not allow to obtain an electrophoretically homogeneous sample provided information on the quaternary structure of the enzyme. A modest, even though of debateable statistical significance, inhibitory effect of CysGly on partially purified CGL was observed

Coherent optical binary polarisation shift keying heterodyne system in the free-space optical turbulence channel

In this paper, analytical and simulation results for the bit error rate (BER) performance and fading penalty of a coherent optical binary polarization shift keying (2PolSK) heterodyne system adopted for a free space optical (FSO) communication link modeled as the log-normal and the negative exponential atmospheric turbulence channels are presented. The conditional and unconditional BER expressions are derived, demonstrating the comprehensive similarity between the 2PolSK and the binary frequency shift keying (2FSK) schemes with regards to the system sensitivity. The power penalty due to the non-ideal polarization beam splitter (PBS) is also analyzed. The receiver sensitivity employing 2PolSK is compared with other modulation schemes in the presence of turbulence and the phase noise. The results show that 2PolSK offers improved signal-to-noise ratio (SNR) performance compared to the binary amplitude shift keying (2ASK)