997 research outputs found

    Avoiding Impotence: Rethinking the Standards for Applying State Antitrust Laws to Interstate Commerce

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    State antitrust laws are broadly constructed. With sweeping, general terms, often mirroring the language of the federal anti- trust laws, most state antitrust statutes manifest a legislative design to prevent-and to punish a variety of commercial activities that are anticompetitive in purpose or effect. These statutes, in conjunction with consumer protection statutes, constitute the primary vehicles through which state authorities protect consumers from harmful, anticompetitive behavior. Of course, despite the importance of state antitrust laws in preserving a competitive marketplace, the Constitution confines their reach. Through the Commerce Clause, the Constitution vests in Congress the exclusive power to regulate interstate commerce. Accordingly, since passage of the Sherman Act in 1890, Congress has promulgated an extensive body of antitrust legislation regulating interstate commercial conduct. Another federal constraint on state antitrust laws arises through the Supremacy Clause. To the extent that state antitrust laws conflict with federal legislation in the same field, courts will find them constitutionally invalid. State antitrust statutes, however, are not completely preempted by federal antitrust laws. Instead, the legislative history accompanying most state and federal antitrust statutes indicates that the two sets of statutes were designed to function as equally potent ingredients in a comprehensive protective scheme. In fact, early federal antitrust legislation directly reflected the policies behind the state antitrust laws of the late nineteenth century; they also reflected contemporary principles of common law. As coexisting and complementary instruments, state and federal antitrust statutes form an excellent example of the potential for effective multi-layered legislation. In one court\u27s analysis, the relationship between the federal and state antitrust laws is a quintessential ex- ample of cooperative federalism. \u2

    Simple computer model for the quantum Zeno effect

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    This paper presents a simple model for repeated measurement of a quantum system: the evolution of a free particle, simulated by discretising the particle's position. This model is easily simulated by computer and provides a useful arena to investigate the effects of measurement upon dynamics, in particular the slowing of evolution due to measurement (the `quantum Zeno effect'). The results of this simulation are discussed for two rather different sorts of measurement process, both of which are (simplified forms of) measurements used in previous simulations of position measurement. A number of interesting results due to measurement are found, and the investigation casts some light on previous disagreements about the presence or absence of the Zeno effect.Comment: REVTeX; 12 pages including 11 figures; figures reformatted to be more readable; some small changes made to the description of the mode

    A Resolved Ring of Debris Dust around the Solar Analog HD 107146

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    We present resolved images of the dust continuum emission from the debris disk around the young (80-200 Myr) solar-type star HD 107146 with CARMA at λ = 1.3 mm and the CSO at λ = 350 μ. Both images show that the dust emission extends over an approximately 10" diameter region. The high-resolution (3") CARMA image further reveals that the dust is distributed in a partial ring with significant decrease in a flux inward of 97 AU. Two prominent emission peaks appear within the ring separated by ~140° in the position angle. The morphology of the dust emission is suggestive of dust captured into a mean motion resonance, which would imply the presence of a planet at an orbital radius of ~45-75 AU

    Polarizing Grids, Their Assemblies and Beams of Radiation

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    This article gives an analysis of the behavior of polarizing grids and reflecting polarizers by solving Maxwell's equations, for arbitrary angles of incidence and grid rotation, for cases where the excitation is provided by an incident plane wave or a beam of radiation. The scattering and impedance matrix representations are derived and used to solve more complicated configurations of grid assemblies. The results are also compared with data obtained in the calibration of reflecting polarizers at the Owens Valley Radio Observatory (OVRO). From this analysis, we propose a method for choosing the optimum grid parameters (wire radius and spacing). We also provide a study of the effects of two types of errors (in wire separation and radius size) that can be introduced in the fabrication of a grid.Comment: 35 pages, 6 figure

    The Segmented Colour Feature Extreme Learning Machine: Applications in Agricultural Robotics

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    This study presents the Segmented Colour Feature Extreme Learning Machine (SCF-ELM). The SCF-ELM is inspired by the Extreme Learning Machine (ELM) which is known for its rapid training and inference times. The ELM is therefore an ideal candidate for an ensemble learning algorithm. The Colour Feature Extreme Learning Machine (CF-ELM) is used in this study due to its additional ability to extract colour image features. The SCF-ELM is an ensemble learner that utilizes feature mapping via k-means clustering, a decision matrix and majority voting. It has been evaluated on a range of challenging agricultural object classification scenarios including weed, livestock and machinery detection. SCF-ELM model performance results were excellent both in terms of detection, 90 to 99% accuracy, and also inference times, around 0.01(s) per image. The SCF-ELM was able to compete or improve upon established algorithms in its class, indicating its potential for remote computing applications in agriculture

    Azole Antifungal Agents To Treat the Human Pathogens Acanthamoeba castellanii and Acanthamoeba polyphaga through Inhibition of Sterol 14α-Demethylase (CYP51)

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    Herein, we have investigated the amebicidal activities of the pharmaceutical triazole CYP51 inhibitors fluconazole, itraconazole, and voriconazole against Acanthamoeba castellanii and Acanthamoeba polyphaga and assess their potential as therapeutic agents against Acanthamoeba infections in humans. Amebicidal activities of the triazoles were assessed by in vitro minimum inhibition concentration (MIC) determinations using trophozoites of A. castellanii and A. polyphaga. In addition, triazole effectiveness was assessed by ligand binding studies and inhibition of CYP51 activity of purified A. castellanii CYP51 (AcCYP51) that was heterologously expressed in Escherichia coli. Itraconazole and voriconazole bound tightly to AcCYP51 (dissociation constant [Kd] of 10 and 13 nM), whereas fluconazole bound weakly (Kd of 2,137 nM). Both itraconazole and voriconazole were confirmed to be strong inhibitors of AcCYP51 activity (50% inhibitory concentrations [IC50] of 0.23 and 0.39 μM), whereas inhibition by fluconazole was weak (IC50, 30 μM). However, itraconazole was 8- to 16-fold less effective (MIC, 16 mg/liter) at inhibiting A. polyphaga and A. castellanii cell proliferation than voriconazole (MIC, 1 to 2 mg/liter), while fluconazole did not inhibit Acanthamoeba cell division (MIC, >64 mg/liter) in vitro. Voriconazole was an effective inhibitor of trophozoite proliferation for A. castellanii and A. polyphaga; therefore, it should be evaluated in trials versus itraconazole for controlling Acanthamoeba infections

    Electronic, vibrational and magnetic properties of a novel C_{48}N_{12} aza-fullerene

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    We study the structural, electronic, vibrational and magnetic properties of a novel C48N12{\rm C}_{48}{\rm N}_{12} aza-fullerene using density functional theory and restricted Hartree-Fock theory. Optimized geometries and total energy of this fullerene have been calculated. We find that for C48N12{\rm C}_{48}{\rm N}_{12} the total ground state energy is about -67617 eV, the HOMO-LUMO gap is about 1.9 eV, five strong IR spectral lines are located at the vibrational frequencies, 461.5 cm−1{\rm cm}^{-1}, 568.4 cm−1{\rm cm}^{-1}, 579.3 cm−1{\rm cm}^{-1}, 1236.1 cm−1{\rm cm}^{-1}, 1338.9 cm−1{\rm cm}^{-1}, the Raman scattering activities and depolarization ratios are zero, and 10 NMR spectral signals are predicted. Calculations of diamagnetic shielding factor, static dipole polarizabilities and hyperpolarizabilities of C48N12{\rm C}_{48}{\rm N}_{12} are performed and discussed.Comment: published in Chem.Phys.Let
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